Maleic anhydride-diethylenetriamine grafted on starch (st-g-(MA-DETA)) was synthesized through graft copolymerization, and the different parameters  affecting starch graft percentage were studied to achieve the maximum grafting percentage. The maximum grafting percentage was found to be 29.17%. The starch and grafted starch copolymer were characterized using XRD, FTIR, SEM, EDS, NMR, and TGA analytical techniques to describe copolymerization. The crystallinity of starch and grafted starch was studied by XRD, confirming that grafted starch has a semicrystalline nature and indicating that the grafting reaction took place typically in the amorphous region of starch. NMR and IR spectroscopic techniques confirmed the successful synthesis of the st-g-(MA-DETA) copolymer. A TGA study revealed that grafting affects the thermal stability of starch. An SEM analysis showed the microparticles are distributed unevenly. Modified starch with the highest grafting ratio was then applied to celestine dye removal from water using different parameters. The experimental results indicated that St-g-(MA-DETA) has excellent dye removal properties in comparison to native starch. Environmental contamination of natural resources has been rapidly increasing in recent years, and it must be addressed as a top priority if the earth and its inhabitants are to be sustained for future generations. Water is vital for all living beings in order to survive and live. Providing safe, inexpensive, and/or clean drinking water is a huge environmental challenge all around the world.Water is used for a variety of purposes in various industries, such as growing fruits and vegetables in agriculture, construction in civil engineering, pharmaceutical formulation and development, electricity generation in power plants, and so on. However, drinking water is an absolute necessity for living beings to survive. As a result, at present, environmentalists are concerned about water pollution, since it has a direct or indirect impact on the health of not only people but practically all species of life .Many pollutants, such as heavy metals, dyes, pharmaceuticals, fertilizers, pesticides, crude oil products, phenolics, radionuclides, and other chemicals, cause contamination of surfaces and groundwater . Dyes arDye molecules decompose in the aquatic environment, resulting in toxic materials that adsorb oxygen from the water, and this has increased to the point where it now poses a serious threat to human life and the environment .There are many techniques applied to isolate dyes and other contaminants from polluted water such as adsorption, ion exchange, coagulation, precipitation, flocculation, membrane filtration, chemical reduction, and electrochemical treatment ,7,8,9. ASeveral ways of developing cheaper and more effective adsorbents, including natural polymers, have recently been proposed. Polysaccharides are one class of biomolecule that have also been investigated as an effective biomolecule for the manufacturing of bio-sorbents from biomass resources, and they can be found in almost all living things, including seaweed, plants, microorganisms, and animals ,13.Starch is a natural polymer originating from different plant organs and is widely used in industry for various applications. Native starch contains amylopectin (70–90%) and amylose molecules (10–30%) which vary in their botanical origin ,15. The 13C NMR, and TGA analytical techniques. Furthermore, the prepared grafted starch will be used to adsorb celestine blue (CB) dye, and the removal efficiency of the grafted starch is compared with native starch. The effects of various conditions such as pH, contact time, adsorbent dosage, initial solution concentration, and temperature are also studied.Grafted starch copolymers are becoming increasingly important because of their potential applications in industry. They have been used as hydrogels, flocculants, ion exchangers, superabsorbents, etc. Grafted starch copolymers can be made primarily by free radical initiation. The aim of this work is the preparation and characterization of a grafted copolymer by construction of organic moieties which possess active functional groups and inserting them into a starch matrix. This material is adjusted for celestine blue removal from aqueous solution, then its various parameters are examined that affect the grafting process. The starch-grafted copolymer has been systematically characterized using XRD, FT-IR, SEM, EDS, Starch , acetic acid , potassium persulphate , sodium bisulfate (99.0%—Sigma-Aldrich), diethylene triamine 99% (Sigma Aldrich), maleic anhydrate , sodium acetate 99% (Sigma Aldrich), ethanol absolute 99% , and analytical grade chemicals and solvents were used in all the experiments.Maleamic acid was synthesized via the interaction between maleic anhydride (MA) and diethylenetriamine (DETA). DETA (0.05 mol) was added slowly to 20 mL of deionized (DI) water in a three-neck flask. Then, MA (0.05 mol) was slowly added to the above solution and stirred for 10 min at room temperature. After that, the mixture was heated at 95 °C for 1 h, and the obtained maleamic acid was stored in a clean glass vial for further studies.An amount of 2 g of starch was dissolved in 100 mL DI water and charged into a three-neck flask, then 3 mL acetic acid was added to the mixture and maintained at 30 °C. Then, various concentrations of redox system initiator (potassium persulphate)  were added to the slurry and left for one hour to form a free radical on the starch backbone. After that, an amount of monomer  was mixed with the above solution. Then, the reaction was carried out under an inert gas environment at various temperatures  and reaction times . W1 (g) is the mass of pure starch, W2 (g) is the mass of grafted starch, and monW (g) is the mass of the monomer.The effects of different parameters were described by Equations (1)–(3) .(1)GrafeqM is the milliequivalent, 𝑉𝑠 and 𝑉𝑏 are the volumes of sodium hydroxide consumed by the sample and the blank, respectively, and NaOHC is the concentration of NaOH in mg/L.A is the volume of NaOH in mL, N is the normality of sodium hydroxide, and W is the mass of the sample in grams.An acid-base titration was performed to estimate the number of carboxyl groups in the different samples of starch. In the first step, 0.5 g of adsorbent was submerged in 25 mL of 0.1 M HCl, then stirred with a magnetic stirrer for 30 min. In the second step, the mixture was washed with 40 mL of DI water to remove the hydrochloric acid. In the third step, the starch samples were transferred to 500 mL beakers and 30 mL of DI water was added, then the mixture was heated for 15 min with continuous stirring to ensure complete gelatinization. Finally, 0.1 mol/L of standardized NaOH and hot starch was titrated using phenolphthalein as indicator. The number of carboxyl groups per anhydroglucose unit was used to calculate the carboxyl content and the degree of substitution was estimated using Equation (4) ,22:(4)MeM1 and M2 (mg/L) are the initial and final concentrations, respectively, and V1 and V2 (L) are the initial and final volumes, respectively.To make the dye stock solution (250 mg/L), 0.25 g of celestine blue dye was dissolved in deionized water. Then, a series of various concentrations was obtained by diluting the stock solutions as follows:max = 644 nm. The adsorption capacity and removal percentage were estimated using the following equation:oC and eC (mg/L) represent the initial and equilibrium concentrations, respectively; V (L) represents the volume of solution; and m (g) represents the mass of the adsorbent.Sorption of the cationic dye by the grafted adsorbent was performed in a batch system with different parameters. A dye solution with a 15 mg/L concentration was prepared and a certain amount of adsorbent (0.05 g) was added to glass containers with 50 mL of dye solution stirred in a shaker at 25 °C, 100 rpm, and a contact time 4 h. After that, the solution was centrifuged for 20 min at 6000 rpm, then filtered. The filtrates were analyzed using a UV spectrophotometer at the maximum wavelength of λDC (mg/L) and DV (L) are the dye concentration and volume of desorbed solution used, respectively. The mass of the adsorbent utilized for desorption is m (g) and the adsorption capacity of the CB loaded adsorbent is eq (mg/g).Adsorption–desorption cycles were used in the regeneration experiments on adsorbents. For each adsorption cycle, 50 mL of dye with an initial concentration of 10 ppm was applied to 0.03 g of adsorbent and shaken for 180 min. Then, the concentration of CB in the solution was estimated by using a UV/Vis spectrophotometer. The dye-loaded adsorbent was filtrated, collected, and dried at 45 °C, then dispersed in 10 mL of 0.2 M HCl and desorbed for 1 h at 1000 rpm and 25 °C, where the concentration of CB was determined by a UV/Vis spectrophotometer. The adsorbent was then recovered and reused in the subsequent adsorption cycle experiment .(10)% D13C NMR spectra of 20–50 mg purified samples dissolved in 450–500 microliters of deuterated DMSO were recorded by . Fourier transform infrared spectroscopy (FT-IR) data were obtained on a . The spectra were recorded in the absorption mode in the range of 4000–500 cm−1 with a 4 cm−1 resolution using KBr pellets made from a mixture of polymer (1 wt%) and KBr. pH measurements were obtained by a pH meter . The morphology of the prepared samples was examined using scanning electron microscopy (SEM) . Thermal gravimetry analysis was performed on a TA-Q500 (Mettler-Toledo). The adsorption efficiency of the bio-sorbent was determined using a UV/vis spectrophotometer .The structural properties of starch and modified starch were obtained using X-ray diffraction, XRD . Nuclear magnetic resonance spectroscopic measurements of monomers and polymeric samples were carried out on Bruker Advance-600 MHz spectrometers. The The synthesis of modified starch was carried out in two steps. First, the monomer was prepared via the acylation of DETA with MA to produce maleamic acid I,  23]. Th. Th23]. The XRD patterns of pure and chemically modified starch are presented in The FT-IR spectra reveal the existence of functional groups present in the synthesized materials. The FT-IR spectra of MA, DETA, prepared monomer MA-DETA, and the modified starch are presented in −1, which are assigned to asymmetric stretching of the carbonyl group; an absorption at 1786–1784 cm−1, which is assigned to symmetric stretching of the carbonyl v(CO); an absorption at 1224 cm−1, which is assigned to the asymmetric ring stretching of =C-O-C=; and absorptions at 1064 cm−1 and 1051 cm−1, which are assigned to the symmetric ring stretching of =C-O-C=. These observations are characteristic of maleic anhydride. The band at 1663 cm−1 and the appearance of a band at 1562 cm−1 can be assigned to the stretching vibrations of the amidine group (N-C=N) and the bending vibrations of the secondary amine of DETA, respectively. MA-DETA exhibits an absorption peak at 3322 cm−1, which indicates the -OH groups, and the peaks at 1762 cm−1, 1521 cm−1, and 1668 cm−1 indicate the formation of MA-DETA.The IR spectrum of MA exhibits absorptions at 1864–1860 cm−1, which is due to the -OH stretching vibration of native starch [−1 is attributed to the O-H link in the glycosidic ring of starch, which is able to take part in intermolecular hydrogen bonding [−1 and 1646 cm−1 are the bands that are related to the C-H stretching of the aliphatic ring and the existence of residual H2O molecules in starch, respectively, whereas the peak at 1337 cm−1 is assigned to -CH2 symmetry. The absorption band in the range of 1100–990 cm−1 is assigned to C-O stretching in the C-O-C and C-O-H bonds in glycosidic rings. To confirm the final structure of the monomer, FT-IR was used to verify the product that arises from the reaction between maleic anhydride and diethylenetriamine, as well as to prove the mechanism by which the interaction occurred, i.e., whether it was via a ring-opening or substitution mechanism shown in e starch . The abs bonding . The pea−1  to a single band at 1745.91 cm−1, the formation of carboxyl groups was implied.Due to the presence of a wavenumber shift of the carbonyl group (C=O) from 1800 and 1774 cm−1. This is might be due to the presence of stretching vibrations of acidic OH interfering with the amide or primary and secondary amines.This result is supported by the presence of a wide band ranging from 3500–3100 cm−1 and 1506.28 cm−1, assigned to the stretching band of C=O and the bending vibration of -NH [−1 is assigned as C-N stretching, while the peak at 1474.90 cm−1 is assigned as CH2 stretching.Two absorption peaks at 1569.04 cmn of -NH ,31,32, c−1, were absent in the prepared monomer (MA-DETA). Additionally, two peaks ascribed to the cyclic imide (asymmetric and symmetric C=O) at 1770 and 1700 cm−1 were also absent. These remarkable disappearances could be attributed to the formation of ring-opening structures under moderate conditions [−1.The cyclic anhydride bands (asymmetric and symmetric C=O), which are present in maleic anhydride at 1800 and 1774.4 cmnditions ,32,33. T−1, assigned to an overlap of the O-H peak of the carboxyl and the N-H peak of the amine. The modified starch spectrum displayed an absorption peak at 1748 cm−1, which belongs to the C=O stretching band of a carboxyl group [−1 is due to the presence of a -CH2 in modified starch [−1 and 3080 cm−1, which is attributed to the interference of the stretching vibrations of -NH, COOH, and -CONH of the organic moieties in starch. The band at 2955 cm−1 is assigned to C-H stretching, the band at 1632 cm−1 is assigned to the C=O stretching vibration, the bands at 1536 cm−1 is assigned to C-N stretching (amide II), and the bands at 1103 cm−1 and 1038 cm−1 are assigned to C-O bending [Furthermore, the FT-IR peaks confirmed the presence of pure starch and modified starch, as well as the additional bands caused by the carboxyl, amines, carbonyl, and amide groups. yl group . Furtherd starch . The FT-13C-NMR. 13C-NMR results of the prepared monomer (DETA-MA), showing the presence of carboxyl group bands (-COOH) at 170.88 ppm, as well as the presence of an amide group (-CONH) peak at 167.74 ppm. This confirms the hypothesis that the reaction is carried out by a ring-opening mechanism. In addition, olefinic carbon atom peaks appeared at 136.61 and 131.19 ppm, which means that the double bond was not affected by the reaction between anhydrous malic acid and diethylenetriamine. A similar chemical shift has been recorded previously [2) adjacent to the amide group appear at 40.99 ppm; second, the protons adjacent to the primary amine group (CH2-NH2) appear at 44.66 ppm; and third, the two methylene bands adjacent to the secondary amine (-CH2-NH-CH2-) have values close to 50.32 and 52.78 ppm.NMR spectra were used to elucidate the structure of the monomer and the grafted starch copolymer. Depending on the location of the peaks and the electronic environment around the atoms, the chemical structure can be confirmed using eviously ,38,39. AThe NMR spectrum of the grafted starch was studied and compared with native starch to determine the positions of newly formed or disappearing peaks to confirm that the grafting process had occurred and to help determine the appropriate reaction mechanism.13C-NMR results of native starch. The carbon atoms from C1 to C6 in the glycosidic ring appear clearly in the spectra. The C1 atom appears at 𝜹 = 100.4 ppm due to it being a C-anomeric atom. The peak of C4 appears at a value of 79.5 ppm, and the peaks at chemical shifts between 73 and 70 ppm are attributed to C2, C3, and C5 carbon atoms associated with hydroxyl groups. The peak at 60.8 ppm is assigned to the C6 atom which is bonded to the aliphatic hydroxyl group.13C-NMR results of grafted starch. They showed the formation of two new peaks which were not present in the pure starch spectrum. The first peak at 207 ppm belongs to the carbonyl of the carboxylic group, and the second peak at 169 ppm belongs to the carbonyl of the amide group. In addition, the peaks of the monomer moieties (CH2-CH2) appear in the range of 30–56 ppm.To support the determination of the grafted polymerization mechanism, the most important products are the carboxylic acid and amide groups. The absence of double bond peaks at 136.4 and 131.19 ppm indicate that the graft polymerization process has occurred through the breaking of the olefinic bond.The most remarkable peaks in the grafted starch spectrum are the new peaks at 57 and 65.39 ppm, which are close to the peaks of carbon C6 and C2 in the starch ring at 60.8 and 72.3 ppm. This indicates that some hydroxyl groups at position 6 could have participated in the grafting reaction ,41,42. NThe morphologies of starch and St-g-(MA-DETA) were analyzed by scanning electron microscopy. In addition, an EDX analysis was carried out to confirm the chemical structure and percentage of each element in native starch and grafted starch. o .TGA was performed to study the thermal behavior of the grafted starch copolymers. o (314 °C) than starch  is observed at 248 °C, indicating the oxidative destruction of the bio-sorbent. Correspondingly, there is a peak at about 313.88 °C, which is due to starch decomposition. Additionally, the direct degradation of starch is attributed to the breakdown of hydrogen bonding between the molecules before melting [ melting .Moreover, the degradation temperature of the modified polymer, The efficiency of graft copolymers for dye removal is dependent on the grafting percentage (G%). For this reason, various parameters were studied as follows:The maximum graft percentage was studied by ranging the temperature from 30 °C to 90 °C. The ratio of grafting progressively increases and reaches a maximum at 60 °C; however, the graft percentage begins to decline when the reaction temperature is higher than 60 °C. This process can be explained by at low temperature (30 °C), the activation energy required for free radicals is low; similarly, at the optimum temperature, the activation energy is high enough to encourage the development of free radicals on starch backbone, leading to an enhanced propagation process. On the other hand, raising the temperature above 60 °C decreases the grafting percentage due to the premature termination of the growing grafted chain at a higher temperature. Additionally, at high temperatures, the formation of homopolymers increases, and this leads to an increase in the viscosity of the reaction medium and inhibits monomer movement and consequently the graft copolymerization ,48.The optimum concentration of the initiator (potassium persulphate (PPS)) was found by varying the concentration in the range of 0.05–1 mol/L. The decrease in the grafting percentage with a high concentration of initiator is due to an excessive increase in free radicals in the starch, activating the multiple free radical coupling that leads not only to forming the homo- and co-polymer, but also to terminating the polymerization process. Therefore, based on this result, using certain initiator concentration resulted in significantly increased the grafting percentage, whereas higher initiator concentrations led to decrease the grafting percentage, this is due to the termination process which causes a shortage in the length of the chain.The concentration of the monomer MA-DETA was varied from 0.15 to 1 mol/L to determine the maximum grafting efficiency. The grafting percentage increased with an increase in the concentration of MA-DETA from 0.15 to 0.45 mol/L, see At first, the grafting percentage increased when increasing the monomer (MA-DETA) concentration and achieved a maximum at 0.45 mol/L. After that, the grafting percentage declined due to the availability of monomer molecules, which might be forming the homopolymer, and the increased viscosity of the reaction medium ,50The data in pzc, of native starch and St-g-(MA-DETA) were estimated by plotting the final pH vs. the initial pH after 24 h. The value of pHpzc at which the initial and final pH are equal was found to be 5.86 for native starch, while it was 6 for St-g-(MA-DETA), as shown in pzc. Alternatively, when the surface of the adsorbent is negatively charged, the pH of the solution is higher than pHpzc. This parameter is critical for manipulating the charge of a certain surface at a specific pH. It aids in demonstrating the most appropriate technique for removing dyes and trace metals.The pH at point of zero charge, pHThe synthesized bio-sorbent (starch-g-(MA-DETA)) was used for dye (celestine blue) removal under ambient conditions. The goal of the study was to explore the effects of different parameters  to determine the optimum parameters for dye removal using the sorption approach.The pH of a reaction mixture is an important parameter as it affects the adsorption efficacy due to changes in the adsorbents’ surface charge and ionization level .pzc, all these functional groups are protonated and the adsorbent surface becomes overcharged with a positive charge, producing a repulsion between cationic dye CB and the polymer surface [pzc, the adsorbent surface becomes overcharged with a negative charge and this leads to the formation of strong electrostatic interactions between the polymer and the cationic dye, followed by an increase in the adsorbent capacity and removal percentage [The pH range (2–10) was varied while the other parameters were fixed at a dye concentration of 15 ppm, adsorbent dosage of 0.05 g, an ambient temperature of 30 °C, and a contact time of 240 min.  surface . In contrcentage . The optThe contact time provides useful information about the time taken to reach equilibrium. The adsorbent–adsorbate contact time was varied (10–1440 min) to determine the maximum CB dye removal percentage at 30 °C and with an initial dye concentration of 15 ppm, as presented in The effect of St-g-(MA-DETA) dosage was investigated using 10–300 mg of sorbent to evaluate the behavior of the grafted starch toward CB dye, whereas all other conditions were constant. The influence of different initial CB dye concentrations on the adsorption process of the bio-sorbent is presented in The adsorption process is affected by rising temperatures. Therefore, the effect of temperature was examined at varying temperatures of 25–70 °C using 0.05 g of sorbent for 240 min. The measurement of how many regeneration cycles that could be reached with grafted starch is considered important. The aim of this process is to evaluate the performance of the adsorbent, the cost-effectiveness, the feasibility of future application, the economic feasibility, the environmental friendliness and the possibility of the removal of adsorbed pollutants. With 10 ppm of CB dye, a pH of 7, 0.2 M of HCl, 20 mL of HCl and 0.03 g of adsorbent, the reusabilities of native starch and St-g-(MA-DETA) were investigated, see According to These findings show that grafted starch (St-g-(MA-DETA)) has a higher stability and recyclability than native starch. It implies strong interactions between St-g-(MA-DETA) and CB molecules. In addition, St-g-(MA-DETA) bio-adsorbent could be regarded as an efficient, renewable, reusable, eco-friendly, low-cost, and stable adsorbent for dye removal applications.13C-NMR analysis confirmed the presence of carbon atoms related to the carboxylic and amide groups in the grafted copolymer, which were absence in native starch. The surface morphology of native starch before and after the grafting process was examined by SEM analysis. The surface is smooth and contains oval granules for native starch, while it is uneven and contains roughly spherical shape particles for the grafted starch. Moreover, a TGA analysis confirmed that the thermal stability of the grafted starch was higher than native starch, at 314.83 and 248.81, respectively. The optimum parameters for obtaining the best grafting percentage were 9 h, 60 °C, 0.3 mol/L of initiator, and 0.45 mol/L of monomer. The removal of CB dye from an aqueous solution using native and grafted starch was influenced by the pH, contact time, adsorbent dosage, initial dye concentration and temperature. The regeneration experiment revealed that St-g-(MA-DETA) is regenerated using a HCl solution and could be reused thirteen times, whereas native starch could only be reused three times. These findings support the efficiency of grafting monomer moieties onto the starch backbone and the enhancement in its thermal properties. In the future, we plan to utilize the grafted starch to remove various types of pollutant, as well as to apply artificial intelligent (AI) models to estimate the performance of St-g-(MA-DETA) in removing other harmful contaminates from water.St-g-(MA-DETA) was successfully synthesized using free radical polymerization. The prepared copolymer was characterized using FT-IR to confirm its chemical structure and it was clearly observed that organic moieties, which include carboxylic, amide and amine groups, were introduced into the main backbone of starch. A


Human noroviruses (HuNoV) are the leading cause of acute gastroenteritis worldwide. The humoral immune response plays an important role in clearing HuNoV infections and elucidating the antigenic landscape of HuNoV during an infection can shed light on antibody targets to inform vaccine design. Here, we utilized Jun-Fos-assisted phage display of a HuNoV genogroup GI.1 genomic library and deep sequencing to simultaneously map the epitopes of serum antibodies of six individuals infected with GI.1 HuNoV. We found both unique and common epitopes that were widely distributed among both nonstructural proteins and the major capsid protein. Recurring epitope profiles suggest immunodominant antibody footprints among these individuals. Analysis of sera collected longitudinally from three individuals showed the presence of existing epitopes in the pre-infection sera, suggesting these individuals had prior HuNoV infections. Nevertheless, newly recognized epitopes surfaced seven days post-infection. These new epitope signals persisted by 180 days post-infection along with the pre-infection epitopes, suggesting a persistent production of antibodies recognizing epitopes from previous and new infections. Lastly, analysis of a GII.4 genotype genomic phage display library with sera of three persons infected with GII.4 virus revealed epitopes that overlapped with those identified in GI.1 affinity selections, suggesting the presence of GI.1/GII.4 cross-reactive antibodies. The results demonstrate that genomic phage display coupled with deep sequencing can characterize HuNoV antigenic landscapes from complex polyclonal human sera to reveal the timing and breadth of the human humoral immune response to infection. Noroviruses (NoVs) belong to the family Caliciviridae and are classified into 10 genogroups (GI-GX) and 49 genotypes. Five NoV genogroups , which contain 38 different genotypes, are capable of infecting humans4. The extensive sequence diversity of HuNoVs leads to immune escape, creating a potential obstacle in the development of a broadly protective vaccine.Human noroviruses (HuNoVs) are the leading cause of both sporadic cases and epidemic outbreaks of gastroenteritis, causing ~200,000 deaths and accounting for a global economic burden of 60 billion USD each year6. The P domain is further divided into P1 and P2 subdomains where the P2 subdomain is exposed on the outer surface and is highly variable in sequence, facilitating escape from an antibody response7. The minor capsid protein VP2 binds to a conserved motif in the VP1 S domain. Its function remains unclear, although it interacts with the viral genomic RNA in murine NoV8.The NoV genome is a single-stranded, positive-sense RNA that is approximately 7.5 kilobases (kb) in length and is organized into three open reading frames (ORFs). ORF1 encodes a large polyprotein that is processed into six nonstructural proteins involved in viral replication including NS1/2 (p48), NS3 , NS4 (p22), NS5 (VPg), NS6 (Protease), and NS7 . ORF2 and ORF3 encode the major (VP1) and minor (VP2) capsid proteins, respectively. The major capsid protein VP1 is comprised of a short N-terminal arm, a shell (S) domain, and a protruding (P) domain. The S domain maintains the integrity of the NoV capsid assembly. The P domain directly binds to histo-blood group antigens (HBGAs) to infect human cells6. Evidence suggests humoral immunity is more effective and longer lasting than T cell immunity in clearance of HuNoV infections9. Many monoclonal antibody (mAb) epitopes for HuNoV have been identified. A recent review summarized over 70 published studies delineating linear and conformational epitopes, mostly residing in VP1, for 307 unique mAbs9. Although mapping epitopes in mAbs is critical for rational vaccine design, it cannot capture the entirety of the polyclonal humoral immune response. To gain a comprehensive understanding of humoral immunity against norovirus infections, identification of epitopes in polyclonal human sera is needed. Previous work has assessed polyclonal human sera from both HuNoV-infected individuals and vaccine trial participants and determined the presence of protective immunity and cross-reactive blockade antibodies in those two cohorts15. Serum HBGA-blocking antibodies increase following HuNoV challenge and natural infections14. A further study examined the serological repertoire of pre- and post-immunized sera from three participants in a bivalent vaccine trial and identified a broadly protective neutralizing antibody and its cross-reactive epitope15. Nevertheless, the comprehensive HuNoV antigenic landscape remains incomplete. A comprehensive map of HuNoV epitopes would provide a systematic view of the humoral immune response during HuNoV infection. Such maps could address questions such as what epitopes are recognized during an HuNoV infection, if the antigenic landscape of HuNoV differs from person to person, if the landscape changes as the infection progresses, and if there are conserved and immunodominant epitopes among HuNoVs.The humoral immune response against HuNoV infections plays a critical role in viral clearance and protection from subsequent infections16. The displayed peptides or proteins are encoded within the genome of each phage particle. Thus, large libraries of peptides can be screened for binding to target proteins by affinity selection and DNA sequencing21. By mapping the epitopes for antibodies elicited by infection, phage display coupled with Next-Generation Sequencing (NGS) can provide a high-resolution view of the epitope landscape during the humoral immune response. Recently, technologies such as VirScan, which uses a library of peptides from 206 species of virus displayed on a T7 phage platform coupled with NGS, as well as a pan-coronavirus phage display library have been utilized to profile immune responses in sera of COVID patients in order to investigate the immune responses against SARS-CoV-224.Phage display involves presenting peptides or proteins on the surface of the bacteriophage capsid25  and any of the three reading frames, the majority of inserts in the naive library are out of frame and will not produce a HuNoV peptide. If affinity selection is enriching for HuNoV peptides recognized by antibodies in sera, the frequency of inserts encoding in-frame peptides should increase with subsequent rounds of selection, while inserts encoding out-of-frame sequences should be eliminated. As seen in Fig. S31, the NS4 epitope is likely conformational . Overall, these results show that the epitope landscape differs between individuals and that the antibodies present during a HuNoV infection are a combination of pre-existing antibodies presumably arising from an earlier infection as well as new antibodies induced by the HuNoV challenge. It is noteworthy that these pre-existing, persistent antibodies apparently did not provide protection from infection in that all of these individuals were infected in the presence of the antibodies.4. Ideally, a norovirus vaccine would target epitopes conserved across genogroups and genotypes. GII.4 HuNoVs have been responsible for the majority of outbreaks over the past 15 years worldwide37. They also induce more severe symptoms that require intense medical care in children38. To understand more about the cross-reactivity of the immune response against HuNoVs as well as the antigenic landscape of GII.4 norovirus, we generated a GII.4 HOV sheared genomic phage display library, using the same methods as described for the GI.1 library. Deep sequencing of the GII.4 HOV naive library revealed a dense distribution of both the forward and reverse inserts along the plasmid sequence with the GII.4 HOV ORFs  had a recent GII.4 Sydney 2012 virus infection. We additionally performed affinity selection using the GII.4 HOV library against the scFv HJT-R3-A9 antibody and rabbit anti-GI.1 VLP antisera, both of which bind GI.1 VP1. The frequency of inserts encoding in-frame HuNoV peptides in the GII.4 HOV naive library and after each round of affinity selection were assessed. Figure SThe insert count and coverage maps generated after deep sequencing of the GII.4 HOV library selections revealed epitopes that are located in NS1/2 p48), NS3 (NTPase), NS4 (p22), NS5 (VPg), NS6 (protease), and the NS7 (RdRp)  and N-terminus of NS4 (p22) isolated from immunological screening was reactive with GI.1 norovirus post-infection sera40. Another report showed that individuals infected with a GI.1 norovirus had a seroresponse to the nonstructural fusion protein VPR, which is composed of VPg, protease, and RdRp41. Further, a recent study that surveyed humoral immune responses against HuNoV in children across Europe reported antigenicity in NS1/2 (p48) and NS4 (p22)42. Our work greatly expands the understanding of the immunogenicity of nonstructural proteins through the identification of epitopes in multiple nonstructural proteins, including those listed above. Specifically, we identified 13 GI.1 epitopes and six GII.4 HOV epitopes in nonstructural proteins.Virus-Like-Particles (VLPs), which are composed of the major structural protein VP1, are highly immunogenic and are vaccine candidates due to their well-studied immunogenicity and epitope profiles46 and Nuclear Magnetic Resonance (NMR) analysis of murine norovirus VPg and a homology model of HuNoV VPg48 are available. HuNoV NS5 (VPg) covalently binds to 5′ end of the viral RNA genome and participates in the initiation of viral RNA replication. The cross-reactive NS5 epitopes for GI.1 (984–1037) and GII.4 HOV (872–942)  and NS7 (RdRp)for GI.1 84–1037 a49. Antibodies targeting this epitope therefore could inhibit the catalytic activity of NS6. The GII.4 HOV NS6 epitope  in both GI.1 and GII.4 HOV. The NS6 epitope detected from GI.1 sera (1095–1180) maps to the cleft of the protease, which includes key catalytic residues in the active site (H1130 and E1154) Fig. 43,49. Anope Fig.  maps to 51 and another epitope includes residues in the thumb region  that interact with the C-terminal tail in the active site cleft during RNA replication52 , which is responsible for the replication of the viral RNA. Two of the four GI.1 NS7 epitopes overlap the active site of NS7 in the palm region n52 Fig. . Therefo9. The first five epitopes, which span residues 6 to 56, are in the NTD of the S domain and are highly immunogenic as they appeared in all six study subjects. There were 15 previously identified GI.1 mAbs that also recognize sites in the 1–43 region of the NTD of the S domain53. The 14 other epitopes in the S domain cover most of the eight β strands B to I7. These have not been reported as neutralizing epitopes. The P2 subdomain is the most antigenic region and contains the binding site for human HBGA during viral infections54. We identified four epitopes in P2. These epitopes were all shown to be recognized by HBGA-blocking, or neutralizing antibodies  are also contained in GI.1 22nd to 25th epitopes  recognized by GII.4F, a human monoclonal antibody generated after acute infection73. The 12th epitope also contains a part of the blockade epitope recognized by a GII-specific monoclonal antibody NORO-32075. The 11th and 12th epitopes are located at the top of VP1 70. The GI.1 and GII.4 HOV epitopes that contain HBGA-blocking residues would therefore be candidates for incorporation into protective vaccines.Our GII.4 HOV results indicated 18 epitopes in VP1, with 10 in the S domain, four in the P1 subdomain, and four in the P2 subdomain, with most of the epitopes identified also discussed by van Loben Sels and GreenVP1 Fig. . Our 16tVP1 Fig. . Lastly,81. They speculated that NS1 secretion is coupled with apoptosis since it is facilitated by caspase-3 cleavage. Another study found that when only murine norovirus ORF1 polyproteins are expressed in a eukaryotic cell system, apoptosis is induced through caspase-9 activation82.Our results clearly show that HuNoV infection elicits antibodies that bind to nonstructural proteins. However, nonstructural proteins are made inside of virus-infected cells, and it is not clear how these proteins would be available for interaction with B cell receptors (BCRs) to generate an adaptive antibody response. Cell lysis following infection could release nonstructural proteins for binding to lymphocyte receptors, resulting in antibody production. Apoptosis of the infected cell is a possible mechanism for cell lysis to release nonstructural proteins. Lee et al. demonstrated that the murine norovirus NS1 and a form of HuNoV NS1 are secreted83.An additional question is whether antibodies to nonstructural proteins could mediate protection from infection. As noted above, several of the identified epitopes map to the active site or functional regions of nonstructural proteins and could block activity. However, it is not clear how antibodies would gain access to the nonstructural proteins since the proteins function within infected cells. Another path by which the antibodies could enhance protection is through their Fc effector functions. Antibodies elicited from nonstructural proteins can activate Fc-mediated effector functions that are used to clear virus-infected cells, including antibody-dependent cellular cytotoxicity (ADCC) or antibody-dependent cellular phagocytosis (ADCP)84. Interestingly, epitopes correlated with increased patient survival were focused in the NSP3 and NSP5 proteases, whereas IgG epitopes that reside in the Spike, Nucleocapsid, and ORF3a accessory proteins were associated with increased mortality84. In addition, the discovery of cross-reactive anti-NS1 epitopes in Dengue and Zika viruses led to the suggestion that NS1 is a viable vaccine candidate and led to passive protection in animal models88. Whether epitopes from HuNoV nonstructural proteins provide protection to infection is unknown. However, our results coupled with the findings with other viruses suggest that nonstructural proteins that induce cross-reactive antibodies are candidates for further investigation and possible use as a screening tool to detect viral infections.Although there are limited reports of epitopes in HuNoV nonstructural proteins, several previous studies have demonstrated that nonstructural proteins of other viruses are rich with epitopes. For instance, a study on COVID-19 patients identified IgG epitopes in all SARS-CoV-2 nonstructural and accessory proteins89. This heterogenous immunity where increased titers of antibodies are generated against conserved epitopes shared between the current and previous strains was also recently observed in SARS-CoV-2 infections91.Our findings also demonstrated the dynamic nature of the longitudinal antibody response over the course of an HuNoV infection. Epitopes identified in the pre-infection sera were present when de novo epitopes were induced post-infection for all study subjects. One explanation for this observation is that the challenge-induced antibodies were against both the GI.1 Norwalk strain and strains that previously infected the individuals. These patterns are similar to “back-boosting” observed in influenza virus immunology, where immune responses are induced against epitopes in the currently infecting strain as well as the previous strains if the epitopes have high homologyWe utilized a GI.1 and a GII.4 HOV genomic phage display library and performed affinity selections against nine unique human sera, 12 sera from different timepoints of three HuNoV infections, a rabbit antiserum, and a monoclonal scFV antibody. Deep sequencing of inserts from the affinity selections identified epitopes in many nonstructural proteins. A role for these antibodies binding these epitopes, if any, for immunity is unclear and worthy of future study. Furthermore, our work revealed extensive longitudinal changes of epitope persistence during HuNoV infections. Finally, we identified cross-reactive epitopes in sera from both GI.1 and GII.4 infected individuals, suggesting cross-genogroup antibodies are elicited during infection. Future work with sera from a more extensive cohort will provide further understanding of epitopes and thus antibody dynamics with respect to immunity against HuNoV infections.30, and three persons with naturally-acquired antibodies to GII.4 NoV provided individual samples. Samples from subjects 715, 720, and 723 in the GI.1 study were collected two weeks after challenge; samples from 731, 732, and 750 were collected before challenge and 1, 2, 4, and ~26 weeks after challenge. Subjects 720, 723, 731, and 732 were diagnosed with gastroenteritis after the challenge while subjects 715 and 750 were not30. Serum samples from BCM13-1 were collected in 2013 while BCM16-1 and BCM16-2 were collected in September and May of 2016, respectively. The study was approved by the Baylor College of Medicine Institutional Review Board.A total of 21 serum samples were included in this study. Six persons who were infected during a GI.1 human experimental infection study provided 18 samples25. A total of 12.8 μg pKS-NV68 plasmid was sheared using a Covaris S2 focused ultrasonicator to a size range of 100 to 500 bp. The sheared DNA was purified using a Qiagen PCR purification column and eluted in 50 μg of 10 mM Tris-Cl (pH 8.5) buffer, resulting in 56 ng/μl and 2.8 μg as the final concentration and amount of DNA, respectively. The ends of the resulting 2.8 μg DNA fragments were blunted and phosphorylated in buffer consisting of 50 mM Tris-Cl, 10 mM MgCl2, 1 mM ATP, 10 mM dithiothreitol (DTT), 0.4 mM deoxynucleoside triphosphates (dNTPs), and 15 units T4 DNA polymerase (New England Biolabs [NEB]), and 50 units T4 polynucleotide kinase (NEB), and 5 units Klenow fragment DNA polymerase, in a 100 μg total volume. The reaction mixture was incubated at 20 ˚C for 30 min, purified using a Qiagen PCR purification column and eluted in 10 mM Tris-Cl (pH 8.5) buffer.The GI.1 pTP663 Jun-Fos phage display library containing inserts from the sheared pKS-NV68 KM plasmid, which encodes GI.1 ORF1 to ORF3, was previously constructed2, 1 mM DTT, and 0.2 mM dATP with 15 units of Klenow DNA polymerase exonuclease (NEB). The reaction mixture was incubated for 30 min at 37 ˚C, purified and eluted in 10 mM Tris-Cl (pH 8.5) buffer.To prepare the DNA fragments for ligation with the pTP663 Jun-Fos phage display plasmid via A-T cloning, deoxyadenosine was added to the end-repaired DNA fragments mentioned above in a 50 μl reaction mixture containing 50 mM NaCl, 10 mM Tris-Cl, 10 mM MgCldam-negative strain of E. coli, the pTP663 Jun-Fos phage display plasmid was prepared for cloning by purifying plasmid DNA using a Qiagen miniprep kit. A total of 9 μg of plasmid DNA was digested with XbaI in 1X NEB CutSmart buffer at 37 ˚C for 2 h in a volume of 200 μl followed by the inactivation of XbaI at 65 ˚C for 10 min. The DNA ends of the pTP663 Jun-Fos phage display plasmids were made blunt by addition of 4 μl of 10 mM dNTPs and 2 μl of Klenow DNA polymerase (NEB) and incubation at 25 ˚C for 30 min, followed by incubation at 70 ˚C for 10 min. The reaction mixture was purified and eluted in 10 mM Tris-Cl (pH 8.5) buffer. Dideoxythymidine was added to the purified DNA in a 100 μl reaction mixture with 1X terminal deoxynucleotidyl transferase (TdT) buffer (NEB) with 0.25 mM CoCl2, 0.2 mM ddTTP, and 40 units of TdT (NEB). The reaction mixture containing T-tailed plasmids was incubated for 1 h at 37 ˚C followed by 10 min at 70 ˚C and separated by agarose gel electrophoresis. The 5300 bp pTP663 band was extracted with a Qiagen gel purification kit and eluted in 80 μl of 10 mM Tris-Cl (pH 8.5) buffer, resulting in a final concentration of 6.7 ng/μl of pTP663 DNA.After growth in a 2, 1 mM ATP, 10 mM DTT buffer at 16 ˚C for 12 h. The reaction was then extracted with phenol-chloroform-isoamyl ethanol, precipitated in 2 volumes of 100% ethanol at −80 ˚C for 1 h, and centrifuged at 13,000 rpm for 15 min. The DNA pellet was dried and resuspended in TE buffer , followed by electroporation of 3 μl DNA into 50 μl E. coli XL1-Blue electrocompetent cells. Transformed cells were selected with 100 μg/ml ampicillin on agar plates. The library size was estimated by the colony count number and the percentage of clones with inserts was determined via deep sequencing of the individual clones. The remaining 445,000 colonies were pooled by mixing LB medium with 100 μg/ml ampicillin with the colonies on the agar plates into a slurry.The sheared and A-Tailed DNA of 100 to 500 bp (1.45 μg) was ligated with the T-tailed pTP663 vector DNA (0.13 μg) in a 250 μl reaction volume of 50 mM Tris-Cl, 10 mM MgCl600) reached 0.6. KM13 helper phage92 was added to 1 × 1010 phages/ml and the cultures were incubated for 30 min at 37 ˚C without shaking and subsequently for 20 h at 30 ˚C with shaking. The removal of E. coli cells was done by centrifugation and the precipitation of phages was carried out by adding 1/5 volume of 20% polyethylene glycol 6000 (PEG 6000), 2.5 M NaCl. The solution was incubated overnight at 4 ˚C, recovered by centrifugation, and resuspended in 1X phosphate-buffered saline (PBS). The GII.4 HOV pTP663 Jun-Fos phage display library inserts from the sheared pKS-SagaFpA50 plasmid encoding GII.4 HOV ORF1 to ORF3 was prepared for this study using the same methods as described for the GI.1 pTP663 Jun-Fos phage display library.Phage production from the pooled library cells was carried out by adding 0.1 ml of the pooled library cells to 30 ml of 2YT medium with 100 μg/ml ampicillin. The culture was incubated at 37 ˚C while shaking for approximately 3 h until the optical density at 600 nm , 1 mg/ml bovine serum albumin (BSA) elution buffer and neutralized with 100 μl of 2 M Tris (pH 8.5) per tube. An aliquot of the eluted phages (250 μl) was used to infect 1 ml of E. coli XL1-Blue cells, this mixture was inoculated in 50 ml 2YT medium containing 100 μg/ml ampicillin, and a total of 1010 phages/ml, or 100 μl, of M13KO7 helper phage , and the culture were incubated overnight at 37 ˚C to amplify the phages. Amplified phages were precipitated using PEG8000/2.5 M NaCl and collected by centrifugation at 4 kg for 30 min. Then the phages were resuspended in 1X PBS and a small aliquot was used to determine the phage titer. This phage preparation was then used for the next round of affinity selection.The first round of affinity selection was performed by placing a 100 μl (1 mg) of Pierce Protein A/G Magnetic beads  into a 1.5 ml microcentrifuge tube and washing with 1X TBS-T with 0.05% Tween-20. Then, 500 μl of human sera (diluted 1:50) was immobilized on the beads in 1X TBS at room temperature for 1 h. The rabbit anti-GI.1 VLP antibody sera was immobilized on beads following the same procedure. The HJT-R3-A9 scFv antibody was purified previously after protein expression in 25. PCR amplification was performed using the amplified phage of the naive library and the enriched libraries as the template. The PCR primers contained a 7-bp barcode sequence at the 5′ end. The barcode sequence is unique to each PCR mixture and has the purpose of assigning sequences to each experiment. After agarose gel electrophoresis and gel extraction, the DNA was extracted, purified using a Qiagen gel purification kit, pooled and used for Illumina NGS.Amplicon-based NGS with the Illumina platform was performed to determine the DNA sequences of inserts in the naive library and after each round of affinity selection94. The inserts that are in-frame to GI.1 and GII.4 HOV ORF1 to ORF3 in the pKS-NV68 and pKS-SagaFpA50 plasmids were determined and counted. The GI.1 and GII.4 HOV ORF2 were divided into consecutive 8-mer long windows. The ratio of in-frame inserts in a window for the naive library and the libraries after affinity selections was defined as number of occurrences of the in-frame inserts divided by the total number of inserts in each window. The ratio of all the in-frame inserts in the naive library and after each round of affinity selection for every individual was calculated by dividing the number of in-frame inserts by the total number of inserts in the experiment.Custom Perl scripts were used on the deep sequencing fastq files to sort the reads, or inserts, into their respective experiments based on the barcodes associated with the amplicons. Another custom Perl script was then used to align the insert sequences to the reference genome to determine the identity and number of occurrences of each insert in each enriched library and the naive library. The Gnuplot program was used to plot the 5′ end positions, 3′ end positions, and number of occurrences of each insert on the x, y, and z axes, respectively. The inserts with a count of 5 or above were selected for the coverage score determination. Coverage scores were determined using the bedtools genomecov program and were defined as the per-nucleotide number of occurrences for each insert after alignment to the reference genome: pKS-NV68 plasmid for the GI.1 experiments and pKS-SagaFpA50 plasmid for the GII.4 HOV experiments95.A custom Python script was used to create the blocks in the dendrogram. Seaborn, a statistical data visualization library based on matplotlib, was used to cluster the blocks with necessary semantic mapping and statistical aggregationFurther information on research design is available in the Supplemental figuresREPORTING SUMMARY


Correction to: Journal of Clinical Psychology in Medical Settings (2023) 10.1007/s10880-023-09940-wDue to an oversight by this article’s authors, the orders of authors’ first and last names are given incorrectly in the original publication. The authors’ names should be listed as follows: Spyridoula Karveli, Petros Galanis, Eirini Marina Mitropoulou, Evangelos Karademas, & Christos Markopoulos.Journal of Clinical Psychology in Medical Settings. https://doi.org/10.1007/s10880-023-09940-w.Likewise, the citation should be as follows: Karveli, S., Galanis, P., Mitropoulou, E. M., Karademas, E., & Markopoulos, C. (2023). The role of attachment styles on quality of life and distress among early-stage female breast cancer patients: A systematic review.


Thoracic endovascular aortic repair (TEVAR) explantation remains a challenge due toendovascular graft ingrowth into the aortic wall with time. Surgical access into theaortic arch can be difficult either via sternotomy or thoracotomy, and proximal barbsbecome engaged firmly into the aortic wall. Explantation often requires extensive thoracicaortic resection, sometimes from the distal aortic arch to the abdominal aorta, followedby reconstruction, risking injury to surrounding neurovascular structures and even death.In cases of blunt thoracic aortic injury, the original injury is often healed, and failedTEVAR could theoretically be removed when thrombotic complications occur. We present anovel technique to facilitate TEVAR recapture with limited distal thoracic aortareplacement.  It often requires extensive aortic exposure to remove a graft deeply embedded insurrounding tissues and to have access to the proximal aspect of the graft where the barbsare securely anchored into the aortic wall. This can be challenging, resulting in increasedrisk of injury to surrounding structures, including the phrenic, recurrent laryngeal, andvagus nerves, as well as risk of paraplegia and death.Thoracic endovascular aortic repair (TEVAR) graft explantation can be required forinfection or thrombus accumulation resulting in thromboembolic events.A 51-year-old patient was transferred to our emergency department following a motor-vehiclecollision. Notable on computed tomography (CT) was the presence of a grade 3 blunt thoracicaortic injury BTAI; . Hewas He was taken to the operating room 2 years later for TEVAR graft explant and proximaldescending aortic reconstruction with a 22 mm Ante-Flo graft . This was done through a left posterolateral thoracotomy through the fourth intercostalspace under deep hypothermic circulatory arrest. The distal arch and proximal descendingaorta were dissected free from the extensive pulmonary adhesions. Proximally, a portion ofthe aorta was dissected circumferentially but was quite adherent to the surrounding tissues.The left carotid artery and left femoral vein were used for full cardiopulmonary bypass.Circulatory arrest was achieved when the patient was cooled to 20 °C and antegrade cerebralperfusion via the left carotid artery. Clamps were placed at the base of the carotid arteryand descending thoracic aorta. The descending aorta was incised, and the distal part of thestent graft was prolapsed out into the left chest and allowed to flush out thromboembolicdebris. A circumferential silk suture was sewn around the distal end of the endostent tocollapse it. We then passed the suture through an 18 Fr GORE dry sheath cover  and pulled the distal end of the endostent into thesheath cover to collapse, re-sheath, and slide it out of the distal arch and proximaldescending aorta with minimal resistance (The patient’s postoperative course was complicated by respiratory failure requiringprolonged mechanical ventilation and delirium, but he eventually recovered and wasdischarged home after a month of hospitalization. Repeat echocardiogram showed a normalejection fraction, normal valvular function, and no wall motion abnormalities. PostoperativeCT of the heart revealed the in situ graft with intact anastomoses ( This technique could be performed with a variety of large-bore vascular accesssheaths or sheath covers. However, the sheath covers must be stiff enough to enable graftrecapture. Notably, this technique has several caveats to be aware of. The rate of successis unknown, and in some cases, the barbs or graft might be fully incorporated intosurrounding structures and impossible to be removed via re-sheathing. Should significantresistance be encountered when attempting to re-sheath the proximal graft, one may need toproceed with wide excision and arch reconstruction. The re-sheathing technique should not beapplied for graft infection because all infected material and surrounding tissue must beremoved for source control. Aortic dissection and rupture remain an important risk with thisprocedure if it is not employed cautiously, since the proximal aspect of the sheath is notvisualized when inserted into the aorta. Therefore, the technique should be avoided inpatients with previous aortic dissection. Patients with heavy thrombus burden shouldprobably not undergo this technique as well, as the risk of precipitating thromboemboliccomplications when re-sheathing the graft remains a concern. We believe this risk can bereduced with careful CT examination and thorough irrigation, flushing, and debridementbefore and after graft explant.The technique we used for stent removal consists of re-sheathing the endostent into alarge-bore sheath cover by pulling it in with silk sutures around the distal graft.Re-sheathing allows secure dissection of the graft from surrounding structures with minimalcollateral aortic trauma. When the sheath approaches the proximal aspect of the graft, thefixation barbs are captured relatively smoothly inside the sheath. This technique allowscollapsing of the stent that is deeply embedded in surrounding structures, without requiringextensive dissection proximally into the aortic arch. This minimizes the need for extensiveaortic reconstruction with its associated risks including nerve injury, paraplegia,infection, and bleeding. Graft design is also important. In 2017, the Food and Drug Administration recalledthe 18 to 22 mm Zenith Alpha Thoracic Endovascular Graft from Cook due to thrombus buildup.The Instruction for Use removed the indication to use this graft for BTAI. When symptomatic graft thrombosis occurs, the definitive treatment is explantation,although endovascular relining or extra-anatomic bypass can be used as temporizing measures. When thromboembolic events occur secondary to graft thrombus buildup, explant must beconsidered if graft relining fails.Although endovascular repair of BTAI offers minimally invasive repair that causes lessphysiologic disturbances in the setting of multisystem trauma, complications exist. TEVARgraft thrombosis can occur secondary to graft oversizing, especially in the 30% range. Youngtrauma patients have a higher risk due to smaller, more conical, and tightly angulated aorta.Hence, in symptomatic TEVAR thrombosis or thromboembolic events, using the re-sheathingtechnique for graft explantation can help recapture the proximal barbs and separate thegraft from the surrounding tissue. This could be used as an adjunct in graft explant as itcan decrease the morbidity associated with extensive aortic dissection proximally into theaortic arch.


It seems that core muscle function affects lower extremity stiffness, and can function as a performance index in athletes. Although performed in healthy volunteers, this study may have implications for injury prevention, highlighting the necessity to perform interspersed endurance training using the different body parts of the kinetic chain. Core stability is the ability to control the position and motion of the trunk over the pelvis and legs to allow the optimum production and transfer of force to the terminal segment in sporting activities. The effect of fatigue, especially core muscle fatigue, on stiffness as a performance index requires more study. This research aimed to investigate the effect of the core stabilization muscles’ fatigue on lower limb stiffness during hopping. Thirty active basketball players participated in this study . The hopping test (15 jumps) was performed before and after the fatigue protocol in three states including at a preferred (no frequency control), maximum, and 2.2 Hz frequency on the force plate. The stiffness of the lower extremities was measured before and after the fatigue protocol. The results of the dependent t-test showed core muscle fatigue led to reduced lower extremity stiffness under all three hopping-test conditions by 15.3–15.9% ( A loss of core stability can expose one to the risk of injury and proper training can reduce the probability of injury . In addiIn the healthcare sector, performing daily activities without pain is desirable, but in the field of competition, achieving the best performance with the lowest risk of injury is a concern . Due to Despite the complex dynamics of the neuromuscular system, simple mass-spring models can acceptably describe these movements . StiffneSeveral methods under natural conditions have been devised for determining stiffness, which measure this variable at the lowest level (stiffness of muscles and tendons), middle level (stiffness of a joint and its surrounding structures), and highest level (stiffness of the limb or the entire body). Various methods have been presented to determine stiffness in biomechanics research. One of these methods is the mass-spring model, which is capable of describing some of human motion. The stiffness obtained from this method is a combination of stiffness values from all body structures and can be influenced by muscle activity levels, nerve reflexes, and individual strategy in the movement . The mosA wide range of research in this field has given attention to studying mechanical stiffness (stiffness of the leg and lower extremity) during exercises such as running, walking, and hopping. Hopping is a biomechanical movement that mimics the spring-like motion of kangaroos and is commonly employed as a clinical test to evaluate the mechanical stiffness and elastic properties of muscles and tendons in the lower extremities ,18. It s2) participated in this quasi-experimental study design. Participants were invited to the laboratory and the implementation process of the tests was explained. Participants were recruited via announcements to university basketball players.Thirty young male basketball players . The participants were informed about the details of the study and provided their written informed consent before study enrolment. Informed consent was obtained from all the participants and procedures were conducted according to the Declaration of Helsinki. Participants were assessed for laterality and were right-side dominant for all criteria, which was identified by using the ball kicking test. The inclusion criteria consisted of age range of 18 to 25 years, no history of injury in the past six months, and experience in playing basketball for at least 3 years. The exclusion criteria consisted of neuromuscular disorders or cardio-vascular problems .At first, anthropometric characteristics including the weight, height, and length of the subjects were measured and recorded. The participants were taught how to hop. The hopping test was performed in three states including at a preferred , maximum, and 2.2 Hz frequency. Subjects performed a warm-up protocol (including 5 min running at their desired speed and 5 min static stretching), before the hopping test. In the preferred hopping test, the subject performed arbitrary hopping. The jump height and frequency were not controlled. In the 2.2 Hz hopping test, a metronome was used and the subjects were asked to coordinate their jumps with the metronome rhythm. Finally, subjects performed a hopping test with a maximum jump height and minimum contact time. All three tests included these considerations: The hopping test was performed vertically and each test was constructed of 15 consecutive jumps. To reduce the effect of the upper limb and shoes on the hopping test, subjects’ hands were put on their waists and they were barefoot. All three hopping tests were performed on both legs, with each leg acting as a pair, to evaluate the mechanical stiffness and elastic properties of muscles and tendons in the lower extremities. The subjects were allowed to practice to ensure the proper implementation of the hopping.The fatigue protocol developed by Abt et al. 2007) was used to measure core stability muscle fatigue in multiple planes of movement . Benjami07 was uslegK) was calculated using the equation of McMahon et al. (1990) [legK was calculated by dividing the maximum vertical ground reaction force (maxF) by the downward displacement of the center of mass (Δy) during the ground-contact phase (Equation (1)). The maxF contact data were extracted directly from force plate data. Various methods have been proposed to calculate Δy. In this study, using the subject’s mass and GRF, the acceleration was calculated. Finally, Δy was determined through double integration of the acceleration data.Force plate  ground reaction force (GRF) data during hopping in the pre- and post-test was recorded at 1000 Hz. The data were filtered with a zero-lag fourth-order low-pass Butterworth filter at 50 Hz . The GRF. (1990) . The Klet test with a significance level of α ≤ 0.05 was used.The mechanical stiffness for each of the five jumps (jumps six to ten) was calculated and the average of these values was normalized to the subject weight. t-test was used to find the significant differences between the pre-test and post-test. Due to the sequential use of the paired-samples t-test, the Bonferroni correction was used to counterbalance the multiple testing applied [Statistical analysis was performed using SPSS software (version 22). Descriptive statistics were used to analyze baseline data for demographic data. The Shapiro–Wilk test results indicated that all data were normally distributed. A paired-samples  applied ; therefot-test showed that core muscle fatigue significantly reduced lower-limb stiffness during preferred hopping by 15.33%, 15.9%, and 15.44% compared to the preferred , 2.2 Hz  and maximum hopping , respectively. Mean and standard deviation of stiffness during preferred, 2.2 Hz, and maximum hopping in pre- and post-test core muscle fatigue reported in The results of the dependent We assumed that core muscle fatigue leads to changes in the stiffness of the lower extremity during the performance of hopping. The results of the study show a reduction in the stiffness of the lower extremity during all three types of hopping following core muscle fatigue. Because many lower-extremity injuries, especially those of the ankle and knee, occur during landing, the hopping maneuver was selected. In performing functional skills that are accompanied by weight loading, stiffness can be affected by muscles, tendons, ligaments, and the skeletal alignment, which works as a unit to modify the rotational stiffness of a joint while making contact with the ground . The rotGiven that fatigue influences these factors, it seems that stiffness also changes as a result of muscle fatigue. The changing of control strategies caused by fatigue can affect the probability of the risk of lower-extremity injury. It is still unknown and requires further investigation how core muscle fatigue is conducive to changes in lower-extremity stiffness. Given that the core muscles are essential to create a stable surface for the proper movement of the upper and lower extremities, core muscle fatigue can affect sports activities . BiomechIt has been reported that the stiffness of the lower extremity has a significant role in improving the performance of running, jumping and hopping exercises, which are seen in many sports. Athletes who use stiffness characteristics more efficiently save more elastic energy during landing, which consequently results in a more concentric force in the push off. This state delays fatigue and ultimately increases running speed . The relCore stabilization depends on the ability to control the body in response to internal forces and external disturbances. These forces consist of forces produced from the distal parts of the body as well as expected and unexpected external disturbances . It is bAlternatively, fatigue can be considered as a generalized and not only a localized phenomenon. A recent systematic review lends some experimental support to the generalized non-local muscle fatigue effect, particularly when examining specific types of performance outcomes, like the hopping tasks examined in this study .Because fatigue reduces the speed of neural transfer, the ability to produce compensatory contractions around joints might be reduced and is conducive to weaknesses of neuromuscular control and further changes in the joint’s condition. Also, more variability in the range of joint movement might reduce the balance in the absence of corrective muscle actions . Given tThe results of the present study have shown the effect of the fatigue of core stabilizing muscles on the stiffness of the lower extremity during hopping, which can be used to enhance training foundations for athletic performance, injury prevention, and rehabilitation. This significant topic has highlighted injury prevention methods and aided towards enhancing the quality of performances of athletic protocols, and has highlighted the necessity to pay more attention to the better quality of training components. According to the advent of more effective spring-like hopping over running, perhaps it is possible to use stiffness in hopping as a more proper index for the level of elastic properties of the muscular system. During hopping, the foot stiffness is equal to the vertical stiffness, and it is extracted by dividing the vertical force of the ground by the displacement of the center of mass. Active muscular stiffness is the main factor in the modification of disturbances and the establishment of dynamic stability. The deterioration of this factor causes the growth of disturbances and places the joint at the end of the ROM, which causes an increase in the tension of ligaments and a risk of injury. The required stiffness for achieving the highest level of performance in sports activity might put the athlete at risk of injury. So, we have to consider an optimum level of stiffness that caters for injury-free sports participation, while maintaining a high level of performance at the same time.This study provided some valuable insights into the effects of core stabilization muscle fatigue on the lower-limb stiffness of basketball players, but it had several limitations. First, it only included male basketball players. Since female athletes have a higher injury risk in similar activities than men, future studies should investigate the gender effect. Second, in addition to fatigue, other factors that can affect the stiffness of the lower limbs of athletes, such as diet and training, should be considered. Finally, in order to better identify the traumatic factors caused by lower-limb stiffness in athletes, future studies should record the activity of working muscles through electromyography as well as kinematic variables of the lower limb.According to the results of this study, there was a significant decrease in the amount of lower-extremity stiffness measured at various frequencies during a fatigue protocol targeting the trunk stabilizing muscles, applied in a group of healthy basketball players. Training programs with an aim to increase the endurance enhancement of the stabilizing muscles of the trunk may lead to less severe deteriorations of lower-limb stiffness, which may improve performance as well as act as an injury prevention mechanism for the safe participation in various athletic activities involving the lower limb.


The decision to use a living or deceased donor to perform uterus transplantation (UTx) is an evaluation of benefit and harm and is based on the medical team's choices. The current study determines the differences between living and deceased donation in human UTx according to determinant factors in choosing the donor type. For this review study, the PubMed database was searched without time, language, and location limitations up to May 2022. From 113 identified articles, 45 papers were included in the study for review. According to the results, in comparison to living donation, the biggest advantage of deceased donation is the lack of surgical and or psychological risks for the donor. In contrast, a comprehensive pre-transplantation medical assessment is less possible in deceased donation, and preplanned surgery cannot be realized. According to published peer-reviewed clinical trials on UTx, the graft failure rates in living and deceased donor UTx are 21% and 36%, respectively. Supposing all recipients who did not have graft failure underwent embryo transfer, live birth rates in living and deceased donor UTx procedures are almost 63% and 71%, respectively. Currently, considering the occurrence of live births from both donations, particularly from nulliparous deceased donor, increased demand for UTx in the near future, shortage of uterus grafts, and lack of sufficient data for a comprehensive comparison between the 2 types of donation, the use of both donations still seems necessary and rational.  In the literature, uterus transplantation (UTx) is considered the latest solid organ transplantation (1), which involves taking a uterus graft from a donor and transplanting it to another woman (2). This novel approach to infertility treatment includes using both fields of assisted reproduction and reproductive surgery (3). UTx is the only treatment for congenital or acquired absolute uterine factor infertility but has not been recognized as a standard method (1). Women without a uterus due to congenital  or iatrogenic  etiologies or women with a malfunctioning uterus due to intrauterine pathologies  are classified as patients with absolute uterine factor infertility . Formerly, these women had no alternatives but adoption and gestational surrogacy to experience motherhood (6). Currently, UTx is the only therapeutic intervention that can restore these women's reproductive function and anatomy (7).The UTx is carried out with uteri from a living donor (LD) and deceased donor (DD); the latter also points out a brain-dead/multiorgan donor (3). The LD is usually a family member or a friend (2). The LD can be genetically related to the recipient, such as her mother (8). The UTx has also been conducted via nondirected LDs, such as women volunteering for hysterectomy  (2) or those who are candidates for hysterectomy due to benign causes . In deceased donation, the uterus graft is obtained from a brain-dead woman (11). When no related or suitable donor is available, the deceased donation is the only potential source for a uterus graft (8). Deceased donation is more ethically approved due to possible harm to the LD and concerns about the LD's consent and the possibility of her regret .The first human UTx was carried out in Saudi Arabia from an LD in April 2000, although it did not lead to live birth (9). Less than 15 yr later, the first live birth worldwide following LD UTx was recognized in Sweden in September 2014 (15). Almost 3 yr later, the first live birth worldwide following DD UTx was reported in Brazil in December 2017 (16). Table I shows an overview of the published peer reviewed UTx clinical trials, although Brännström et al. believe that numerous cases have not yet been published (3).There are still discussions and controversies surrounding the type of donor for UTx (2), as LD UTx is a very invasive surgery, and on the other hand, according to the organ transplantation guidelines, the organ should be harvested from a DD (17). The decision to use LD or DD is a benefit and harm assessment and is based on the medical team's choices (18). The present study aims to determine the differences between living and deceased donation in human UTx based on determinant factors in choosing the donor type.In this narrative review study, for the identification of the related articles, the PubMed database was searched using the terms “uterus transplantation” or “uterine transplantation” in combination with the associated terms, such as “living donor”, “deceased donor”, and “brain-dead donor”, up to 10 February 2022 without time, location, and language limitations. The details of the search strategy used are presented as follows:1: “Uterine transplantation” [Text Word] OR “Uterine transplantation” [MeSH Terms]2: “Uterus transplantation” [Text Word] OR “Uterus transplantation” [MeSH Terms]3: 1 OR 24: “living donor” [Text Word] OR “living donor” [MeSH Terms]5: “live donor” [Text Word] OR “live donor” [MeSH Terms]6: “living donation” [Text Word] OR “living donation” [MeSH Terms]7: “brain dead donor” [Text Word] OR “brain dead donor” [MeSH Terms]8: “deceased donor” [Text Word] OR “deceased donor” [MeSH Terms]9: “deceased donation” [Text Word] OR “deceased donation” [MeSH Terms]10: “multiorgan donor” [Text Word] OR “multiorgan donor” [MeSH Terms]11: 4 OR 5 OR 6 OR 7 OR 8 OR 9 OR 1012: 3 AND 11On May 1, 2022, the search results were updated. In addition to the electronic search, a manual search was conducted by reviewing the reference lists of the retrieved articles to identify more related articles.All types of articles  with a focus on the features associated with human UTx using LD or DD, including the risks and advantages for donor and recipient, the evaluation of the donor, the procurement of the uterine, the implementation of the transplantation procedure , and the outcomes of the transplantation (graft failure and live birth) were included in the study. Nonhuman UTx studies were excluded from this study.The retrieved articles were imported into the Endnote software. For selecting articles, first, the titles and abstracts of the papers were screened, and unrelated articles and related ones without available full-text versions were excluded. For the data extraction, the full texts of the relevant articles identified in the previous stage were reviewed, and the data related to the above-mentioned features were extracted.A total of 113 English articles were retrieved from the PubMed database. After excluding unrelated articles and those without available full-text versions, the full texts of 45 articles were reviewed. The results of the study, including the differences between living and deceased donation regarding the risks and advantages of the UTx for the donor and recipient, the evaluation of the donor, the procurement of the uterine, the implementation of the transplantation procedure, and the outcomes of the transplantation, will be discussed in the subsequent sections.As the uterus is not a vital organ, only slight harm to LD is acceptable (30); however, uterus retrieval from an LD is generally a high-risk, long, complex (11), and invasive surgery (17). The risks of hysterectomy in LDs are higher than in conventional hysterectomy (2). The main intraoperative and postoperative complications include urinary tract complications, infection, bleeding, thrombosis, and hematoma (38). Bowel injuries, vaginal cuff dehiscence, ureterovaginal fistula, urinary tract infection, nocturia, leg pain, fecal impaction, meralgia paresthetica (18), and injury to the ureter (4), the bladder, the rectum, the pelvic nerves, and the iliac vessels (39) are other reported complications. Several studies have demonstrated that more than 1 in 10 LDs develop complications requiring further surgical intervention following uterine donation (7).If the ovaries of a premenopausal LD are removed during uterus procurement surgery (25) or ovarian veins are used for vascular anastomosis (which can lead to the disruption of ovarian blood flow and excision of the ovaries), the LD might be at risk for early menopause  and its aftermaths, such as an increased risk of mortality and morbidity (6). The reason is that ovaries are vital endocrine organs that can play protective roles in women even decades after menopause, and on the other hand, the exogenous hormone therapy used to reduce symptoms in menopausal women is associated with long-term health risks (41).The prolonged duration of LD surgery in UTx is associated with an increased risk of thromboembolic events, especially pulmonary embolism (8). Furthermore, in some studies, for 3 months before the operation, hormone replacement therapy for menopausal LDs has been prescribed to ensure uterine menstrual functionality and possibly increase the circulation of uterine arteries (42). This approach also puts LDs at an increased risk of thromboembolic events before and immediately after the operation (43).Nevertheless, in clinical trials performed, surgery complications in LDs have been identified and successfully resolved (29); on the other hand, increasing experience in performing UTx procedures and using less invasive techniques, such as robotic-assisted laparoscopy, the rate, and severity of surgical complications for LDs have decreased (30); however, the long-term risks, particularly in LDs that have undergone oophorectomy, have not yet been fully elucidated (29).Uterine recipients of DDs might be at risk for hemorrhage. This is because the dissection and ligation of the uterus vessels of DDs are conducted outside the body during the back-table preparation stage and in this situation, small vessels are difficult to find around a white uterus that has been flushed with a preservative solution. This makes vascular assessment before the reperfusion more difficult in the uterus of DDs in comparison to LDs. If the microscopic vessels of the tissues adjacent to the uterus are not meticulously ligated for transplantation, hemorrhage after reperfusion will occur during recipient surgery, and if homeostasis is not maintained, the recipient will develop intra-abdominal complications, hematoma surrounding the uterus, and retroperitoneal hematoma (17).Unfavorable psychological consequences in LDs might occur in some conditions, such as the early failure of the graft, the breaking down of the donor-recipient relationship, and if the transplanted uterus does not lead to the delivery of a healthy newborn despite surviving for a long time (8). Kisu et al. believe that unstable mental conditions, such as anxiety and depression, might occur even with favorable outcomes (40). The LDs might feel loss or harm, as numerous women have such feelings following a hysterectomy (18). Although living without a uterus is clinically insignificant, there are important consequences for uterine donation. Since the uterus symbolizes sexuality, femininity, attractiveness, vitality, youth, and childbearing; hysterectomy can lead to postoperative regression, loss of feminine self-image, distortion of body image (44), decreased quality of life , loss of gender identity , changes in sexual libido (39), increased sexual dysfunction , and decreased sexual satisfaction (49). Surgical scars on the abdomen can distort body image, and numerous women might feel physically unattractive following the operation (40).For the recipient, receiving a uterus from an LD can be an unpayable debt . The complex relationship between LD and the recipient might lead to embarrassment, anxiety, and guilt in the recipient due to the involvement of another healthy woman in her misfortune (49). In the case of using relative LDs, both the donors and the recipients might have concerns regarding family dynamics and experience external and internal pressures for donation or reception of the uterus. Therefore, recipients might prefer DD to avoid or decrease worries related to consent, voluntariness, and risks for LD (52). LDs, such as mothers, sisters, and aunts, sometimes claim a right to children born from donated uteri and expect more contact with the newborns, similar to the expectation of surrogate mothers (53). Consequently, exerting control of an LD over the recipient in the future or influencing her decisions can occur in cases of LD UTx (50).The promotion of psychological well-being due to helping an individual for giving birth is one of the psychological benefits of donation for LD (18). The LDs experience a long-term increase in self-esteem, happiness, and quality of life following donation and feel grateful for having the opportunity to live with a loved one who regains her health. Particularly, the family gains considerable psychological benefit from the donation (53). If a successful delivery occurs following a donation between related individuals, the positive effect of having a healthy child on quality of life and psychological health might last for many years (4). Moreover, depending on the nature of their relationship with the recipients, LDs might enjoy having a relationship with the born children (53).In LD UTx, there is an opportunity for long term and meticulous evaluation of LD and her uterus before donation . These evaluations increase the possibility of transplanting a uterus with a high chance of survival after transplantation and a high probability of pregnancy and childbirth. Detailed and precise obstetrics and gynecology history with a comprehensive medical history can be obtained from the LD that can assist in deciding on the exclusion of potential donors with a risk of repeated miscarriages, preterm birth, preeclampsia, and other high-risk obstetric conditions. Periodic prescription of estrogen-gestagens can be used to assess uterine bleeding patterns and thickness, as well as the appearance of the endometrium in postmenopausal LDs (8).In deceased donation, there might be limited information about the medical history of DD, which can have undesirable consequences for the transplantation. In multiorgan donation in DD, there is often less than 24 hr since the time of consent to the removal of organs (8). In this situation, the results of all tests should be available within 12-24 hr (3). This short time might reduce the likelihood of routine pretransplantation assessments and evaluation of uterine arteries (8). In addition, it is not possible to prescribe hormone replacement therapy for postmenopausal DDs (55).Examining psychological factors, including psychological stability, is an important issue only in LD screening (3). The donor should not have poor psychological health or psychiatric disorders (8); in other words, she should have the mental capacity to consent (56). The donor should be briefed about donation's short-term and long-term risks (41), and her informed and valid consent should be obtained by physicians and psychologists after in-depth and compulsory consultation (10). In the case of deceased donation, the DD (before death) or her surrogate (after death) should be consented (53).The technique of uterus retrieval from a DD is like that of an LD but is simpler and faster . A Turkish team has reported the length of the procurement of the uterus from a DD as 2 hr (57), and in a trial in the United States, the authors have reported this time as approximately 60-90 min (11). In the first UTx trial by a Swedish team that included 9 LDs, the donors' surgery duration was reported as 10-13 hr (3). Gradually, the duration of uterus retrieval from LDs has been reduced with the development of surgical methods. For example, in a trial performed by a Chinese team, the procurement surgery of the uterus with complete robot assistance lasted for 6 hr (25). Additionally, in an Indian trial using traditional laparoscopy with laparotomy, the authors have reported this time as approximately 3-4 hr .In LD, the length of the excised vascular pedicles is shorter, and the risk of damage to them is higher than in DD (58). In the uterus retrieval from DD, it is possible to harvest longer vascular pedicles with a larger diameter , which will lead to better and easier suturing of the vascular pedicles, a lower risk of thrombosis in the transplanted organ , and reduced complications and rejection rate in the recipient .In DD, it is possible to cut the ureters on both sides of the uterine vascular pedicles; nevertheless, in LD, it is necessary to meticulously examine the ureteric tunnels to separate the vessels from the ureters (8) as deep uterus veins are firmly attached to the ureters (3). The most sensitive part of the LD hysterectomy is the 360º dissection of the ureteric tunnel when releasing the uterine vascular pedicle (34). However, in DD, a major part of the dissection of the uterine vein can be conducted by separating branches from the deep iliac vein and from the uterovesical venous plexus by a bipolar sealing device to reduce the risk of damage to the adjacent tissues (8). As the accurate identification and separation of uterine vessels, particularly veins, is quite challenging, it is possible in DDs to use ovarian vessels for vascular anastomosis; nonetheless, in premenopausal LDs, there is no desire for oophorectomy, using them is not possible (11). Moreover, in DDs, the excision of a more extended vaginal cuff for a better vaginal-to-vaginal anastomosis and, thus, the elongation of the recipient's vagina is possible (59).For the UTx procedure, one surgical team for the retrieval, one team for preparation of the graft on the back table, one team for transplantation, and 2 anesthesia care teams, one for the donor and one for the recipient, are usually needed. Each surgery team includes at least 2 or 3 members (4). The procedure can be preplanned with the entire multidisciplinary team. This approach allows all key members to rest well and prepare appropriately (54). Unaccelerated preparation can lead to learning and memorization of the various stages of the surgery (4). In addition, having the same surgical team is an advantage that leads to faster learning of different parts of the procedure. In planned surgery in LD, a roadmap can be developed before transplantation, which can secure a shorter and safer surgery (8).When a DD is identified, the above-mentioned 4 or 5 teams should be prepared quickly; given that brain death cannot be anticipated, these teams should be prepared 24 hr a day and 7 days a week. Surgery might be more difficult due to the need for rapid retrieval of the organ. Less time for preparation with excessive fatigue and stress associated with difficult procedures, possibly performed at night, can increase surgery complications (4). On the other hand, in the circumstances that the donation is carried out in a different hospital that is far from the transplant hospital, if the same surgeons perform the transplantation, the workload of the uterus-harvesting team might significantly increase, and this can negatively affect the transplantation procedure (8). Logistics, such as air transportation on permanent standby in deceased donation, are also required (4).Considering the shortage of DDs , the waiting time for receiving a matched uterus graft from a DD is uncertain. The recipients must be on continuous standby, and this might lead to the frustration of transplant candidates or the demobilization of the medical team in the experimental phase (4). Therefore, the benefit of using an LD is the shorter waiting time for the transplantation (10).As using DD requires logistical measures, such as air transportation on permanent standby, on-call medical teams (4), or access to an operating room for a relatively long surgery (59), presumably, DD UTx will be more expensive than LD UTx (4). Nonetheless, no donor recovery and postoperative costs are among the advantages of using DD (29).UTx failure is defined as the need to remove the graft before embryo transfer (60). According to the data in table I, the graft failure rates in LD, and DD UTx procedures are 21% (11/52) and 36% (4/11), respectively. Given that out of 63 described procedures, almost 82.5% and 17.5% were LD and DD UTx, respectively, comparing the failure rate between the 2 approaches to donation is difficult and demands more DD UTx procedures.Several studies have demonstrated that graft failure can be partially attributed to the poor quality of the graft, particularly its poor perfusion (3). After menopause, the size of the uterus decreases, periodic fluctuations in the uterus blood flow are no longer present (8), and age-related negative changes in the myometrium, endometrium, and or uterine vasculature might also occur (3). On the other hand, atherosclerosis develops with the increase in age. Therefore, the older age of the donor can be an obstacle in using the organ of both LD and DD (8). LDs are typically older than DDs (52) because, in living donation, a woman who has completed her parity and no longer needs the reproductive function of the uterus can be a candidate for uterine donation (4).Another factor that negatively affects the organ's quality is systemic inflammation observed in DDs . Ischemia can also negatively affect the quality of the graft (4). Ischemia at body temperature  or during the storage of the graft outside the body at hypothermic condition  might lead to histologic and metabolic damages, which are intensified during the reperfusion of the organ and lead to acute or chronic loss of the organ functions (60).The CI time in DDs is usually longer than in LDs because the uterus of an LD is transmitted to a recipient in a near operating room; however, the uterus of a DD might be transmitted to a recipient in another center (17). Furthermore, back-table evaluation increases the CI time (8). Nonetheless, several studies have demonstrated that the uterus has good tolerance to CI (40). For example, in deceased donation, long periods of CI up to 6 hr and 20 min (16) or 9 hr and 9 min (52) have led to live birth. The WI occurs in 2 stages; the first stage of WI occurs at the time of organ harvesting (48). The second stage occurs during vascular anastomosis in the recipient (60). The longer harvesting time leads to a higher risk of damage to the organ (48). In DD, harvesting the nonvital organs, such as the uterus, should be after the vital ones, and this can increase the time of the first stage of WI (40).Regarding the long-term survival of the graft, Kisu et al. believe that in deceased donation, due to organ damage as a result of factors, including prescription of catecholamines to the donors in the agonal stage, systemic inflammatory changes, and prolonged ischemia time (40), long-term graft survival is less than a living donation (48). Nonetheless, this is not of great importance for women whose uterus is removed after the delivery, as UTx is considered temporary and short-term transplantation (40).Another factor that influences graft survival is histocompatibility. The higher human leukocyte antigen (HLA) compatibility leads to better graft survival outcomes (48). Using intrafamilial LDs' uterine graft reduces complications related to histocompatibility (4) and exposure to foreign HLA (8). If the donor is the recipient's mother, they match at least half of the HLAs; if she is her sister, the HLA complete matches are 25% (48). In deceased donation, the histocompatibility between the donor and the recipient is low, and there is a greater risk of graft rejection. Therefore, the recipient needs higher doses of immunosuppressive drugs, which increases the risk of oncologic and infectious side effects (4).The primary goal of UTx is a live birth (61). According to the data of table I, supposing that all recipients who did not have graft failure underwent embryo transfer, live birth rates in LD and DD UTx procedures are almost 63% (26/41) and 71% (5/7), respectively. Although the risk of pregnancy complications after solid organ transplantation and in vitro fertilization is significantly higher than spontaneous pregnancy without a transplant, there might be differences in the incidence of these complications between the 2 donation methods. For example, regarding the risk of preeclampsia during pregnancy following UTx, it has been suggested that sclerotic and low elastic arteries in older LDs can increase the risk (52). Nevertheless, in young DDs, there is no vascular pathology, such as atheroma, and arteries have elastic walls, which can prevent obstetrics complications, such as preeclampsia (4).In DD uterus recipients, pregnancy complications, such as placenta previa with accrete (29), pyelonephritis (16), preterm premature rupture of the membranes, intrauterine growth restriction, suspected preeclampsia (20), and gestational diabetes mellitus (35) have been reported. Intrahepatic cholestasis (21), pre-eclampsia, hydronephrosis (15), placenta previa marginalis, pregnancy-associated hypertension (35), anemia , gestational diabetes , vaginal bleeding , cervical incompetence, preterm delivery, intrauterine fetal demise (34), preterm prelabor rupture of membranes, mild oligohydramnios, and small for gestational age (30) are also documented as pregnancy complications in LD uterus recipients. As in comparison to LD UTx procedures, only a small number of DD UTx procedures have been conducted, a complete comparison of the rates of live births and pregnancy complications between these 2 types of donation needs further data.Collecting more data on the effectiveness and safety of using the uterus of DDs makes it possible to accurately compare the outcomes and risks of living and deceased donation (29). If the long-term outcomes of deceased and living donation are similar, or even if deceased donation outperforms living donation , and there are enough uteri from DDs available, living donation will not be continued to avoid risks for LDs . Nonetheless, considering the expected increase in demand for UTx in the future and the shortage of uterine grafts , currently, UTx through both types of donation is rational.In the present study, the articles were searched with no time, location, or language limitations, which is one of the study's strengths. The clarity of the search strategy also makes it possible for other researchers to replicate it. Moreover, this review study only includes the articles on the PubMed database.The current study findings can be informative for both clinicians and the public. Considering the experimental nature and the relatively small number of UTx procedures performed worldwide, I recommend implementing further procedures, especially DD UTx. I also suggest making great efforts to raise public awareness about UTx and methods of uterus donation, particularly deceased donation.Both living and deceased donations can provide suitable uteri for delivering a healthy neonate. The main disadvantage of using LD is the risks for the donor. In the deceased donation, there is no such concern; however, restricted uterus assessment before donation and the lack of the possibility for planned surgery are the main disadvantages of using the uterus of DD. Given the insufficient available data, it is difficult to compare the clinical outcomes between the 2 types of donation. Therefore, it is rational to use a combination of both LD and DD at this stage.The author declares that she has no conflict of interest in the present study.