B, were more than 3. Similarly, the value of an interfacial parameter, K, was less than 1.21  as per the Nicolais–Narkis model, which indicated better interfacial interaction. For composite films, the modified Halpin–Tsai model was revised again by introducing the orientation factor, α, which was 0.333 for the randomly oriented continuous nanofiber-reinforced composites, and the exponential shape factor, ξ = (2In this study, a simple approach was described to investigate the theoretical models for electrospun polymer nanofiber-reinforced nanocomposites. For predicting the tensile strength of the electrospun nylon 6 nanofiber-reinforced polyurethane acrylate composites, conventional Pukanszky, Nicolais–Narkis, Halpin–Tsai, and Neilson models were used, while for Young’s modulus, Halpin–Tsai, modified Halpin–Tsai, and Hui–Shia models were used. As per the Pukanszky model, composite films showed better interaction since the values of the interaction parameter,  Polymer nanocomposites reveal significant high-performance properties using small fractions of nanofillers in the polymer matrices. The excellent properties of nanocomposites have attracted extensive attention in distinct technologies such as automobiles, energy, sensors, fuel cells, agriculture, and biotechnology ,2,3,4,5.During the last few decades, the electrospinning technique experienced substantial progress and attracted researchers from various fields, such as biomedical, sensors, energy, and environmental applications ,10,11. MDue to their higher molecular orientation and higher crystallinity, ultrafine-diameter nanofibers show improved mechanical performance, including tensile strength, Young’s modulus, and toughness compared to microfibers ,18. ManyRecently, many electrospun nanofibers have been successfully employed to reinforce the polymer matrix. Many processes have been reported for the fabrication of nanofiber-reinforced composites, including solution impregnation, layer-by-layer coating, dip-coating, melt mixing with short electrospun nanofibers, in situ fabrication, casting, draining, and subsequent stacking by hot-press ,22,23,24Polymer nanocomposites do not follow the rule of mixture for estimating mechanical properties, as conventional composites do. However, the mechanical characteristics of the composites cannot be estimated correctly due to the small fractions, novel size, and properties of the nanomaterials. Distinct models were suggested to predict the mechanical characteristics of nanofiller-reinforced polymer composites and short fiber-reinforced composites. However, not a single study  has been published on the estimation of mechanical properties of nanofiber-reinforced composites. It is crucial to investigate the mechanical properties with modeling and simulation studies of the nanofiber-reinforced polymer nanocomposites. They became significant motifs because of the need for the advancement of these materials for in high-performance engineering applications. Gao et al. presented a numeric model to evaluate the elastic characteristics of the high-aspect-ratio short aramid fiber-reinforced composites . Sun et cE) of the nylon 6 nanofiber-reinforced polyurethane acrylate nanocomposites (N6/PUA) were evaluated from experimental and theoretical views. The Pukanszky, Nicolais–Narkis, Halpin–Tsai, and Neilson models for the ultimate yield strength, and the Halpin–Tsai, modified Halpin–Tsai, and Hui−Shia model were used, assuming randomly oriented continuous nanofibers. Moreover, the assumptions of these models showed good agreement with the experimental results.In this study, the ultimate tensile strength and Young’s modulus /formic acid  polymer solution was used as a precursor solution to electrospun nanofibers using electrospinning units . Difunctional polyurethane acrylate oligomer  and isobornyl acrylate monomer diluent (Miramer M1140) were supplied by Miwon Specialty Chemicals Co. Ltd., Jeonbuk-do, Korea. Irgacure 184D  was used as a photocatalyst.2, Arc system). The detailed procedures of the electrospinning of nylon 6, fabrication of N6/PUA nanocomposites, and characterizations were reported in our earlier research [The UV-curable polyurethane acrylate (PUA) matrix system was formulated with 50% difunctional polyurethane acrylate oligomer, 45% isobornyl acrylate monomer (as a diluent), and 5% of Irgacure 184D. Nylon 6 nanofiber-reinforced polyurethane acrylate nanocomposite films were fabricated by over-coating the nanofibers on the PUA matrix system, which consisted of casting, electrospinning, and UV curing. The formulated UV-curable PUA matrix system was cast on the glass substrate, and nylon 6 nanofibers were electrospun on the PUA-coated glass substrate for different deposition times  without any break. Afterward, the nanocomposite was cured in a conveyor-belt-type UV-curing machine LZ-U101  fixed with a gallium lamp , parameter B can be calculated with Equation (2):The Pukanszky model  explainecσ) and tensile yield stress of a polymer matrix (mσ) deviates as a two-thirds power law function, with K as an interfacial parameter for filler matrix adhesion. Equation (3) is stated as follows:For the Nicolais–Narkis model, the ratio of the tensile yield stress of the composite (fϕ), filler properties, structure, and interfacial interaction. If the adhesion between the filler and matrix polymer is not established, then the filler cannot bear the applied load, and the whole load is transferred to the matrix phase. In this equation, the parameter K counts for the adhesion between the reinforcement (filler) and matrix. The lower the K value, the stronger the adhesion. For an extreme case of weak adhesion, the theoretical value of K is 1.21 [The mechanical characteristics of the nanocomposites rely on the volume fraction  and (5), as follows:icient K , as statφ as a filler packing factor. According to the Neilson model, the tensile strength is given as the following Equations (8) and (9):Similarly, the Neilson model is termed the modified Halpin–Tsai model, as Neilson revised the original equation by introducing maxφ is the maximum packing fraction constant, and it is 0.82 for randomly oriented fibers.cE of several nanocomposites, where the reinforcement is in the form of nanofibers, nanotubes, nanorods, and nanoparticles with capricious aspect ratios [fE, cE, and mE are the Young’s modulus of the fiber, composite, and matrix, respectively. fϕ is the nanofiber volume fraction, and η is the shape factor relating to the reinforcement geometry. τ is the aspect ratio lThe Halpin–Tsai Model anticipates the t ratios ,33,34,35α, accounted for the randomly oriented fiber. Likewise, in this case, the orientation factor, α, accounted for the randomly oriented fibers. If the length of the fiber is larger than the thickness of the samples, the fibers are assumed to be randomly oriented, and the value of the parameter is considered to be 0.333 (α = 1/3). If the length of the fiber is much smaller than the thickness of the specimen in randomly oriented fiber composites, then α = 1/6 is used [The Halpin–Tsai model (Equations (10) and (11)) correlates the modulus of the unidirectional fiber composites to the fiber volume fraction. This model cannot authentically predict the modulus of nanofiber-reinforced polymer nanocomposites, since it does not deliberate definite features of the nanofibers such as their high surface area, very high aspect ratio of nanofibers, dispersion of the nanofibers, and exceptional Young’s modulus of the nanofibers. However, nanofiber-reinforced polymer nanocomposites have a random alignment of the nanofibers in the matrix. Much research explored anticipating the modulus of randomly aligned fiber-reinforced composites by modifying the Halpin–Tsai model ,36,37. I is used ,36,38,39τ, to the ξ = –(20) are stated as follows:α’ is the converse of the aspect ratio , and g is assumed to be a geometric parameter of composites, which is expressed in Equations (18) and (19). Equation (18) refers to the incorporation of fiber-shaped fillers, while Equation (19) is applicable to the incorporation of flake- or plate-like nanofillers. Additionally, for a flawless interface, g would be stated in Equation (20).The Hui–Shia model equation broadens the estimation of  fillers . The HuicE, tensile strengths, and % elongation were collected according to the average six sample estimates for an individual case. The mechanical characteristics of N6/PUA nanocomposites are noted in cE of the nanocomposites were enhanced with the introduction of nylon 6 nanofibers. There were no significant variations observed in % strains compared to the reference samples for each composite.The discrepancy is much more familiar in modeling nanocomposite properties by the conventional rule of mixture or micromechanics models. In this section, we implemented the different models, and compared model predictions with the same set of available experimental data compiled in the previous study . The matB was determined by befitting experimental values with the mathematical values, and derived from the minimum sum of squares of variance more than from experimental values of composite strength. Pukanszky’s model underestimated the experimental data with the tensile strength of nanofiber-reinforced nanocomposites, when constant B = 0. It means that the nanofiber-reinforced nanocomposites dominated with better interfacial adhesion amongst the polymer nanofibers and matrices, and thus amelioration in tensile properties was depicted with the embodiment of reinforcement of the nanofibers. For the curve fitting, the constant B values were calculated by employing Equation (2), constant B values were 6.82, 5.75, 5.05, 4.27, and 4.04 for the N-15, N-30, N-60, N-2 h, and N-4 h N6/PUA nanocomposites, respectively, which indicated that nanofiber-reinforced nanocomposites at a nanofiber content from 0.004 to 0.066 vol%, revealed better interfacial bonding, resulting in more effective filler–matrix load transfer.The theoretical values of tensile strength were estimated with the Pukanszky model using Equations (1) and (2), and compared to the experimental values of nylon 6 nanofiber-reinforced PUA polymer nanocomposites. The constant K were considered as 1, −1, −2, and −5 for the Nicolais–Narkis model. Using values of K, the tensile strength was estimated for the composites using Equation (1). As shown in K values were approximately −5 for the N6/PUA matrix composites.The theoretical predictions of tensile strength were compared employing the Nicolais–Narkis model Equation (3) and compared to the experimental values, as depicted in φ, the values were quite similar to the Halpin–Tsai equation  and (5). However, the experimental and Halpin–Tsai model values showed higher bound values than the experimental values for the high-volume fraction of the nanofibers in composites. After modification of the Halpin–Tsai equation by Neilson with the introduction of factor equation b.cE of the N6/PUA nanocomposites with the different volume fractions are plotted in cE of not merely unidirectional aligned fiber-reinforced composites, but also of several nanocomposites where the reinforcement phase has functionality relating to the aspect ratio in regards to CNF, CNTs, and cellulose nanofibers. As shown in cE as the volume fraction of nanofibers is enhanced. The experimental data of relative strength and the predictions of the model did not properly follow the experimental data at numerous nanofibers concentrations because of the absence of some parameters, such as an alignment of the nanofibers, shape factor, and aggregation in the composites.The deviations of ξ and orientation factor α were introduced, and modified the model as shown in Equations (12) and (13). In this research, ξ values were assumed and the graph was plotted for nanofiber-reinforced composites, as shown in cE of nanofiber-reinforced nanocomposites, and it was clearly found that the calculations were above the experimental data as volume fractions of the nanofibers increased in the composites. There was no significant difference observed for ξ > 200. Furthermore, the ξ  had the form of ξ =  and (13) with the following exponential shape factor:After periodically modifying the coefficients of aggregation ξ. In this study, the shape factor ξ was picked to conceal the randomly aligned nanofibers with different volume fractions, and it underrated the value of cE of the nanofibers loading to a little below 0.008% volume fraction. Moreover, the mechanical characteristics of the composites at marginally higher wt% of nanofibers were a little overestimated using this modified model by reasonably extrapolating results.However, model Equations (12) and (13), associated with Equation (21), are termed the modified Halpin–Tsai equation for nanofiber-reinforced composites. cE of the nanofiber-reinforced composites, α’, an inverse of the aspect ratio was correlated with the perfect interface geometric parameter g [α’ = 0.001). Therefore, for calculating the geometric parameter g, Equation (19) was used, and it perfectly matched with the values from Equation (20). It is well known that the orientation of the dispersed phase has a substantial effect on the composite cE. It was evidenced from their geometry that disk- or plate-like fillers can contribute equal reinforcement in two directions if proportionately oriented, while fibers contribute primary reinforcement in one direction. In this case, the nanofibers were randomly oriented, and if the longitudinal modulus and transverse modulus were known, the effective modulus of the composite in all orthogonal directions [cE,E11, and E22 are effective, longitudinal, and transverse Young’s moduli of the composite, respectively. x is the constant to govern the stress transfer amongst the fibers and matrix systems in the composites, which is based on the curve fitting with experimental data (0 < x < 1). As shown in x was calculated to be about 0.9, but it could only provide a rough estimation for cE of randomly oriented nanofiber-reinforced composites. The percentage errors of cE prediction for nanofiber-reinforced composites became much less than the experimental result data, and theoretical predictions appeared to overestimate experimental result data at higher volume fractions. The overestimated results could be based on the geometric constants engaged in the equation.Hui–Shia model Equations (14) and (15) demonstrated higher aspect ratio estimation with the presence of randomly oriented fillers in matrix systems, and an increasing degree of fiber aggregation with increasing fiber content. For predicting the ameter g ,40,41. Trections  could beFrom the above analysis, we can identify that in order to obtain more precise predictions of the tensile properties of nanofiber-reinforced polymer nanocomposites, nanofiber aspect ratio, distribution of nanofibers, and volume fraction of the nanofibers are fundamentally important. These models simultaneously review these parameters and ensure a simple approach to predict the mechanical characteristics of the nanofiber-reinforced polymer nanocomposites. However, it is a significant challenge to establish a more comprehensive model capable of considering the nanofiber geometry, agglomeration, critical nanofiber length, and so on, which is the subject of future research.fV). Additionally, theoretical values predicted using the modified Halpin–Tsai model showed close agreement with the available experimental values of Young’s modulus, due to the introduction of exponential shape factor ξ in the form of ξ = (2A comparative study among the experimental results and several theoretical models of filler reinforcement was implemented to predict the mechanical characteristics of electrospun nylon 6 nanofiber-reinforced PUA nanocomposites. Our findings suggested that the theoretical results predicted employing the Pukanszky model and Nicolais–Narkis model are in close agreement with the tensile strength experimental values of the nanofiber-reinforced nanocomposites. Meanwhile, the Neilson and Halpin–Tsai models of tensile strength showed higher bound values than the experimental values for the high-volume fraction of the nanofibers in composites (for 0.033 and 0.066


Salmonella with multiple research papers. Key to the increase in AMR and virulence are plasmids, whose importance is briefly discussed in this editorial. The acquisition of various large plasmids has impacted the global epidemiology and cross-country dissemination of Salmonella enterica strains. Plasmids are extrachromosomal, generally circular DNA molecules that often contain genes that provide bacteria several biological functions including virulence and AMR [Salmonella large plasmids possess multiple AMR genes and virulence factors; hence, co-selection of AMR and virulence properties yield potentially more dangerous pathogens [This special issue of Microorganisms highlights the importance of antimicrobial resistance (AMR) and increased virulence of  and AMR . Some ofathogens . CommonlSalmonella virulence plasmids, commonly known as pSV plasmids, are one of the more well-studied plasmids [Salmonella plasmid virulence (spv) operon, a highly conserved 7.8-kb region, harboring several virulence genes promoting intracellular infections in hosts [spvABCD genes encode proteins that are translocated into host cells via the type-3 secretion system (T3SS) and modulate host immune responses by several mechanisms, including preventing actin polymerization and down-regulating host immune responses [spv in virulence and pathogenesis during the infection process was delineated using different model infection approaches, such as the subcutaneous mouse model [plasmids ,4,5. pSVin hosts . spvABCDesponses ,7,8. These model ,9 and zese model .Salmonella serovars including Kentucky, Typhimurium, and Schwarzengrund. In a study by our group, an IncFIB plasmid was transferred to an IncFIB plasmid deficient strain of S. enterica by conjugation [S. enterica serovar Kentucky [Salmonella isolates from different poultry sources. The IncFIB plasmid was found to occur predominantly in serovar Kentucky (72.9% of isolates tested), followed by Typhimurium (15%) and Heidelberg (1.7%); the latter two serovars are among the most commonly associated with disease in humans [S. Schwarzengrund isolates clustered within the same clade, which was separated from the isolates that lacked IncFIB plasmids (unpublished data). These findings suggested that IncFIB containing S. Schwarzengrund persist in a food environment and successfully establish infection in human.Another group of plasmids that contribute to virulence are the incompatibility group (Inc) FIB plasmids that are related to the ColV plasmid, and are commonly found in several jugation . The trajugation . AnotherKentucky . Addition humans . In a reS. enterica strains contain another virulence-associated plasmid, an IncX4-like plasmid that harbors a VirB/D4 type 4 secretion system (T4SS) [Salmonella survive better inside macrophages and epithelial cells by likely down regulating the host’s innate immune response. In a study, it was shown that multiple Salmonella strains contained IncX4-VirB/D4 plasmids isolated from retail meats, food animals, and human patients associated with a disease outbreak [Some m (T4SS) . The Viroutbreak . These dSalmonella and Escherichia coli from food animal sources, resulting in clinical significance of bacteria carrying this type of plasmid. These plasmids have the potential to carry and horizontally transfer multiple integron-associated AMR genes including sul1 and sul2 sulfonamide resistance genes, and the blaCTX blaCMY, blaSHV, and blaTEM genes that encode resistance to multiple cephalosporins among enteric pathogens [Salmonella inhibit growth of E. coli which is likely a beneficial selection advantage in growth competition in certain environment [The IncI1 plasmids are widely distributed in enteric bacteria, particularly athogens . In addiironment .S. Infantis has been associated with the acquisition of a unique mega-plasmid known as the plasmid of emerging S. Infantis (pESI), that confers multidrug resistance and increased virulence phenotypes [E. coli and other pathogenic bacteria in the gut environment [The recent global emergence of enotypes ,18,19. Denotypes . Studiesironment .tnp) genes and are widespread in all domains of life [As the examples above demonstrate, plasmids are important elements that can impact public health. Many plasmids carry mobile genetic elements (MGEs), such as integrons and insertion sequences (ISs), that facilitate transfer of AMR genes. ISs are the simplest MGEs that generally harbor one or more transposes ( of life . IS26, a of life , was fou of life . IS26 is of life ,26. IS26 of life ,27.Salmonella strains can harbor multiple virulence-associated plasmids and become highly virulent. While some gene transfer mechanisms are known, more research is needed to identify other unknown mechanisms as to how virulence and AMR plasmids disseminate among Salmonella and other pathogens. This will likely aid the development of proper intervention strategies to control the spread of these plasmids in pathogens prevailing in the food-animal environment.It is likely that the widespread use of antibiotics has facilitated the emergence of highly resilient pathogens that pose a threat to public health via co-selection of AMR genes and virulence factors . These p


These changes were not seen with placebo. Dopamine also decreased ventilatory and mean arterial pressure responses to hypoxia (p < 0.05 for both). Inhibition of PChRs led to a decrease in V˙E/V˙CO2 comparing to placebo , with no effect on peak oxygen consumption. We found a significant relationship between PChT and the relative decrement of V˙E/V˙CO2 on dopamine comparing to placebo . There was a trend for correlation between PChS (on placebo) and V˙E/V˙CO2 during placebo infusion , but the relative improvement in V˙E/V˙CO2 was not related to the change in PChS (dopamine vs. placebo). We did not find a significant relationship between PChT and PChS. In conclusion, inhibition of PChRs in HFpEF population improves ventilatory efficiency during exercise. Increased PChS is associated with worse (higher) V˙E/V˙CO2, whereas PChT predicts an improvement in V˙E/V˙CO2 after PChRs inhibition. This results may be meaningful for patient selection in further clinical trials involving PChRs modulation.Peripheral chemoreceptors (PChRs) play a significant role in maintaining adequate oxygenation in the bloodstream. PChRs functionality comprises two components: tonic activity (PChT) which regulates ventilation during normoxia and acute reflex response , which increases ventilation following a specific stimulus. There is a clear link between augmented PChS and exercise intolerance in patients with heart failure with reduced ejection fraction. It has been also shown that inhibition of PChRs leads to the improvement in exercise capacity. However, it has not been established yet: 1) whether similar mechanisms take part in heart failure with preserved ejection fraction (HFpEF) and 2) which component of PChRs functionality (PChT vs. PChS) is responsible for the benefit seen after the acute experimental blockade. To answer those questions we enrolled 12 stable patients with HFpEF. All participants underwent an assessment of PChT (attenuation of minute ventilation in response to low-dose dopamine infusion), PChS (enhancement of minute ventilation in response to hypoxia) and a symptom-limited cardiopulmonary exercise test on cycle ergometer. All tests were placebo-controlled, double-blinded and performed in a randomized order. Under resting conditions and at normoxia dopamine attenuated minute ventilation and systemic vascular resistance ( The num of 1-2% .Clinically HFpEF presents with typical signs and symptoms of HF . Among tThere is some evidence that abnormal reflex control contributes to exercise intolerance in HFrEF , 2001. TApart from an augmented reflex response , the potential role of heightened tonic activity  of PChRs in exercise intolerance must be acknowledged. Its relation to worse exercise tolerance in HF population has not been extensively studied. Similarly, it is unclear whether the level of tonic activity is related to the sensitivity of acute reflex response in a given individual with HF. It is possible to directly assess the magnitude of tonic activation of PChRs using various approaches including hyperoxia  and low-2 slope) were observed. Based on these results obtained from HFrEF patients, one could speculate, that similar mechanisms may be in play in HFpEF. Data from some animals models indicate that central but not peripheral chemoreceptors are predominantly responsible for the autonomic imbalance seen in HFpEF   with a diagnosis of HFpEF in NYHA (New York Heart Association) II or III functional class were enrolled into the study after signing an informed consent. All subjects had to be clinically stable and optimally treated for at least 12 weeks before the study entry. The diagnosis of HFpEF, according to the current European Society of Cardiology guidelines criteria, was verified at initial evaluation and was based on the presence of signs and symptoms of HF, results of blood sampling, spirometry, electrocardiography and echocardiography . The preformula) , seriousThe study was performed in accordance with the Helsinki Declaration and was approved by the local Institutional Ethics Committee .−1 min−1, which is known to effectively inhibit PChRs   and Kansit PChRs . The samEchocardiographic imaging was performed according to recommendations of the American Society of Echocardiography and the European Association of Cardiovascular Imaging  using st2 (EtCO2) was sampled from the expiratory arm of the circuit and measured with capnograph . The inspiratory arm of the circuit was connected to the electric valve allowing for the silent switching between 100% nitrogen gas and room air. Hemodynamic parameters including: mean blood pressure (MAP), heart rate (HR), cardiac output (CO) and systemic vascular resistance (SVR) were continuously, non-invasively measured using Nexfin device . Oxygen saturation (SpO2) was collected with a pulse oximeter  using a lightweight probe attached to the earlobe. All the parameters were processed with PowerLab  and recorded on a laptop computer .Peripheral chemoreceptors function testing was performed twice in each subject—during an infusion of low-dose dopamine and during the placebo infusion in a supine position. After adjusting silicone nasofacial mask  patients were connected to a one-way open breathing circuit. A spirometry set  was attached to the expiratory arm of the circuit for continuous measurements of tidal volume (TV) and breathing rate (BR) from which minute ventilation (MV) was calculated. End-tidal CObaseline was recorded. Subsequently, the infusion of dopamine or placebo was initiated and continued for 10 min. This period was defined as “recording during infusion”. Next, after 5 min of rest, an analysis of acute sensitivity commenced which consisted of several (5-7) administrations of pure nitrogen gas (each for 2-20 s), which resulted in minimal values of SpO2 in a range between 90% and 65%. Length and order of hypoxic exposures was random and they were separated by 3-4 min of breathing with room air which allowed for the normalization of recorded parameters. Finally, the infusion of dopamine or placebo was withdrawn and the test ended.All patients were tested according to the same protocol depicted on 2 gas for time period lasting between 2 s and 20 s. This procedure was repeated 5–7 times per study participant which resulted in minimal SpO2 between 90% and 65%. After each N2 administration subjects were allowed to rest for 5 min breathing room air. A ventilatory response was averaged from the three largest consecutive breaths following the end of N2 administration and plotted against the associated nadir of SpO2 providing Point 1. Baseline values of MV and SpO2 were averaged from a 90 s period preceding each N2 administration. Then, baseline MV was plotted against baseline SpO2 providing Point 2. The slope of the regression line linking Point 1 and Point 2 was found for each N2 exposure. Arithmetic average of values of the slopes for all N2 administrations (−1 %−1) (PChS was assessed using well-described transient hypoxia method . Subjecttrations  was take(−1 %−1) .2 nadirs was calculated (HR slope and MAP slope respectively) to express the magnitude of acute hypoxic reactivity of a given hemodynamic variable.The hemodynamic responses to hypoxia were calculated in the analogous way as PChS. Hemodynamic data were smoothed by a moving average (10 s window) in order to eliminate the effect of fluctuations in HR caused by respiratory sinus arrythmia or atrial fibrillation. The slope of linear regression describing the relation between the peak values of HR and MAP after nitrogen administrations and corresponding SpO−1) was defined as the absolute decrease in MV following initiation of dopamine infusion. MV was averaged from the last 2 min of steady baseline recording and from the 2 min of recording during infusion, when changes in ventilatory and hemodynamic parameters stabilized following initiation of dopamine infusion . ECG was continuously monitored during the stress test . The cardiopulmonary exercise tests begun with a 5-min long resting phase to allow for familiarization with the equipment. Following the resting phase workload was set at 20 W and increased by 10 W every minute until maximal tolerated level of exertion was achieved  was performed in the upright seated position twice in each subject—during an infusion of low-dose dopamine and on saline. During the tests ventilatory parameters, end-tidal COachieved . The sub2), peak carbon dioxide production (peak V˙CO2), slope relating ventilation to oxygen uptake (V˙E/V˙O2 slope), slope relating ventilation to carbon dioxide production (V˙E/V˙CO2 slope), respiratory exchange ratio (RER) : peak oxygen uptake (peak V˙Oio (RER) , and peaexercise .P value < 0.05 was assumed as statistically significant.LabChart 8 , MATLAB  and Statistica 13  were used for analyzing the data. The data were blinded for the researchers responsible for PChS and PChT calculations. The statistical analysis was performed with the Wilcoxon matched pairs test and variables were presented as mean and standard deviation (SD) or mean and standard error of the mean (SEM). Spearman rank method was used for correlation calculation. The baseline clinical and physiological characteristics of the study population (n = 12) are presented in Δ = 6.2%, p = 0.03), SpO2 , SVR  but increased HR  and CO   and a trend for increase in EtCO2 . After placebo infusion a fall in SpO2  and increase in MAP  were observed while other ventilatory and hemodynamic parameters remained unaffected.Under normoxic resting conditions dopamine administration significantly attenuated MV  . We also−1 %−1 comparing to -0.4 ± 0.4 L min−1 %−1 (Δ = 35.1%) on dopamine. This difference was statistically significant (p = 0.0096). Additionally, dopamine infusion decreased MAP slope  with no effect on HR slope  .The mean PChS measured during placebo infusion was -0.6 ± 0.7 L min p = NS) . There wp = 0.24). There was a trend for a correlation between PChS on placebo and V˙E/V˙CO2 slope on placebo . Hemodynamic slopes on placebo  did not correlate with peak exercise indices .We did not find a relation between PChS (when measured on placebo) and PChT (p = 0.007) and between PChT and peak workload . No other correlations were found between PChS, PChT and exercise-derived parameters.Interestingly, significant positive relation was found between PChT and exercise time  and increased EtCO2  but had no effect on other reported peak exercise parameters . Furthermore, dopamine improved ventilatory efficiency by reducing V˙E/V˙CO2 nadir .The peak exercise values of the ventilatory and hemodynamic parameters are presented in 2 slope was related to PChT  (We found that both relative and absolute improvement in V˙E/V˙COctively) . Such co2 slope) following inhibition of PChRs with low-dose dopamine. We also present the inhibitory effect of dopamine on ventilatory response to hypoxia, and on resting minute ventilation. Using a novel approach based on the separate assessment of two components of PChRs functionality  . The stu−1 %−1 vs. 0.58 L min−1 %−1)  . This isTwo-thirds of the study population suffered from diabetes mellitus or impaired glucose tolerance. There are some premises suggesting that PChRs contribute to the control of glucose metabolism . RibeiroVisceral obesity was also present in most patients investigated in our study. Obesity often coexists with obstructive sleep apnea syndrome where repetitive apnea/hypopnea episodes augment CBs sensitivity and increase sympathetic gain . FurtherMoreover, all patients in our population suffered from hypertension which has been previously linked to PChRs’ oversensitivity  and hype−1 %−1). However, all those groups were characterized by considerably lower age than currently studied HFpEF population.The interpretation of PChS level in our work is limited by the lack of control group of age- and sex-matched healthy individuals. In the previous studies, where identical methodology of PChS assessment was employed  consiste−1 min−1 in order to activate selectively D2 presynaptic receptors (2 and post-synaptic type 1 dopamine receptors (D1) resulting finally in the augmentation of the neural traffic from CBs with subsequent hyperventilation, due to relative domination of D1 receptors  shows an affinity to β1‐receptors which may lead to mild positive inotropic and chronotropic effects , low-dose dopamine infusion also diminished the ventilatory response to hypoxia (PChS) and MAP slope, but did not influence HR slope when compared to placebo. This observations are in line with the results of our previous studies performed in healthy individuals . The dis2 slope. The decline in V˙E/V˙CO2 was modest but still statistically significant. Our results are supported by the fact that dopamine infusion did also significantly decrease nadir V˙E/V˙CO2 . Furthermore, our findings correspond well with previous papers reporting numerically modest but statistically significant improvements in ventilatory efficiency (reflected by V˙E/V˙CO2 slope) following various interventions. In the paper by Chua et al. blockade of peripheral chemoreceptors with dihydrocodeine led to decrease in V˙E/V˙CO2 slope from 34.19 ± 2.35 to 30.85 ± 1.91 (p = 0.01)   as recently reported by Vitale et al. (We showed that inhibition of PChRs with low-dose dopamine results in an improvement (decrease) of V˙E/V˙CO = 0.01) . Modulatp < 0.01 . Treatme= 0.023) . Finallye et al. .2 is an index of ventilatory effectiveness on exertion. Higher level of this parameter reflects increased ventilatory drive and is a well-recognized marker of poor prognosis  (p < 0.001)  . Similar< 0.001) .2 slope could be a result of either diminished ventilation or increased production of CO2. As we did not find a significant difference in peak V˙CO2 between stress tests performed on placebo and dopamine, it should be assumed that the attenuation of ventilation during exercise is mostly responsible for this benefit. An inhibition of PChRs with dopamine diminishes ventilation at rest and we assume that this effect is also in operation during whole exercise. This is further supported by the fact that the degree of improvement (decrease) in V˙E/V˙CO2 slope was proportional to the magnitude of MV attenuation following dopamine initiation (PChT). A decrease in tonic respiratory drive from PChRs might be further aggravated by a concomitant decrease in central respiratory drive, as a hyperadditive interaction between PChRs and central chemoreceptors has been previously described (−1 min−1) caused improvement in vascular conductance and oxygen delivery with no changes in ventilation (2 of 25 ml kg−1 min−1 and V˙E/V˙CO2 of 31.7). Therefore, we speculate that due to possibly low PChT in this apparently mildly affected population low-dose dopamine could not exert its ventilatory benefits as seen in our study.Mathematically a decrease in V˙E/V˙COescribed . Interestilation . This di2 slope has important clinical consequences. Attenuation of excessive ventilation on exertion reduces the subjective sensation of dyspnoea  . It should be noted that in all mentioned studies (including our work) the improvement in V˙E/V˙CO2 occurred following the inhibition of both components of PChRs functionality.The unique protocol employed in our study allowed for the separate assessment of the involvement of PChS and PChT in the ventilatory efficiency during exercise. In the study by Chua  inhibiti = 0.01) . CB rese = 0.01)  and bettInterestingly, we found that only PChT reflected the magnitude of improvement in exercise tolerance. In the study by Stickland et al.  dopamine2 slope. This can be explained by the following mechanisms. First, it is possible that the degree of inhibition of acute responsiveness arising from PChRs achieved with low-dose dopamine is not sufficient to translate into meaningful decrease in ventilation on exertion. Second, keeping in mind that the partial pressure of O2 remains fairly stable during exercise (2 slope (during placebo infusions) seen in our and in numerous previous studies? We believe that high PChS ought to be seen more as a marker of advanced HF  reduction in V˙E/V˙COexercise , it coulough CBs , where n2 slope in our study, it did not improve exercise tolerance as reflected by unchanged peak V˙O2. Thus, the exercise tolerance in HFpEF is likely determined by factors other than dysfunctional PChRs. For example, Toledo et al. demonstrated overactivation of central but not peripheral chemoreceptors in rats with HFpEF. Furthermore, acute stimulation of central chemoreceptors provoked increase in sympathetic gain, abnormalities in cardiac function and induced cardiac arrhythmogenesis  . This as−1 min−1 employed in our work has been shown to effectively inhibit both acute and tonic activity of PChRs  in HFpEF, the magnitude of which was similar to that previously reported in HFrEF . Our pro


Sub‐nanometric materials (SNMs) represent a series of unprecedented size‐/morphology‐related properties applicable in theoretical research and diverse cutting‐edge applications. However, in‐depth investigation and wide utilization of organic SNMs are frequently hindered, owing to the complex synthesis procedures, insufficient colloidal stability, poor processability, and high cost. In this work, a low‐cost, energy‐efficient, convenient, effective, and scalable method is demonstrated for directly exfoliating chitin SNMs from their natural sources through a one‐pot “tandem molecular intercalation” process. The resultant solution‐like sample, which exhibits ribbon‐like feature and contains more than 85% of the single molecular layer (thickness <0.6 nm), is capable of being solution‐processed to different types of materials. Thanks to the sub‐nanometric size and rich surface functional groups, chitin SNMs reveal versatile intriguing properties that rarely observe in their nano‐counterparts (nanofibrils), e.g., crystallization‐like assembly in the colloidal state and alcoplasticity/self‐adhesiveness in the bulk aggregate state. The finding in this work not only opens a new avenue for the high value‐added utilization of chitin, but also provides a new platform for both the theoretical study and practical applications of organic SNMs. A one‐pot “tandem molecular intercalation” process is developed to efficiently produce chitin sub‐nanometric nanoribbons with unprecedented >85% of single molecular layer. Thanks to the sub‐nanometric size and rich surface functional groups, these nanoribbons reveal versatile intriguing properties that rarely observed in their nano‐counterparts (nanofibrils), and thus provide new platform for both theoretical study and practical applications of organic sub‐nanometric materials. The most archetypal and pioneering sub‐nanometric material must be graphene; it has enjoyed a great deal of studies on its monatomic structure and intriguing properties, and so do other inorganic/carbon SNMs such as carbon nitride, black phosphorus, transition metal dichalcogenides,and MXenes. Their successful and widespread applications have incentivized and laid a fertile ground for the rapid development of organic SNMs . Unlike inorganic/carbon SNMs, monolayered organic SNMs have customizable structures and functionality by selecting diverse building blocks or postmodifying functional groups, and thereby have become focal point in polymer research.Sub‐nanometric materials (SNMs) refer to nanomaterials with at least one of their dimensions that reaches atomic or single molecular level, which is capable of bridging the gap between traditional nanomaterials and molecules.1 Comp Through the confined polymerization/crosslinking of preassembled monomers between two phase interfaces , large‐area organic nanofilms with monomolecular thickness can be directly synthesized. However, after decades of development, these methods are still limited for widespread applications, on account of their tedious synthesis procedures , rigorous reaction conditions (ultrahigh vacuum), high cost (expensive substrates), and low productivity. In order to solve these problems, a top‐down exfoliation method is inspired from inorganic 2D materials and utilized to produce organic SNMs . This approach involves the topochemical synthesis of layered polymer crystals, in combination with solvent‐diffusion and external mechanical treatments . The selective cleavage of interlayer secondary forces is the key factor for the exfoliation of atomically thin and even single‐layered organic SNMs. Therefore, these polymer crystals, which should have robust intralayer covalent/coordinate linkage while weak interlayer interactions , must be meticulously designed. Over the past decade, a series of new synthetic techniques have been developed for the production of lamellar organic crystals, such as single‐crystal to single‐crystal approach and 2D covalent organic frameworks (COF) synthesis. Despite these contributions, stable and concentrated dispersion with a high proportion of single‐layered organic SNMs, which is capable of being solution‐processed to different types of materials , keeps far from being in‐depth studied and achieved for wide applications.Bottom‐up strategies, such as on‐surface and topochemical polymerization, have been first applied to produce organic SNMs since 1989.5 Thro Many crystallographic results have revealed that these fibrillar crystals are naturally gifted with lamellar structures that consist of monolayered molecular sheets  with weak interlayer binding force, which make them a suitable candidate for the exfoliation of organic SNMs. Nonetheless, current researches mainly focus on the exfoliation and application of nanometric intact nanofibrils; there are only a few reports about the in‐depth delamination of nanofibrils to monolayered molecular sheets, albeit with a high energy consumption and relatively low yield. In our previous work, we reported an original finding that dimethylsulfoxide (DMSO)/KOH mixture, a commercially available pseudosolvent of chitin, was capable of selectively disrupting robust cohesion between nanofibrils, as well as interlayer secondary forces between chitin molecular sheets. Through a sequence process of pseudosolvent swelling and maleic anhydride surface ionization, we not only realized the self‐exfoliation of chitin nanofibrils (ChNFs) in aqueous solutions, but also discovered ribbon‐like structures containing a few layered molecular sheets. This unexpected result encourages us to produce monolayered chitin SNMs by further downscaling the thickness of the above nanoribbons.Natural biopolymers, such as cellulose, chitin, and silk, mainly exist in the form of semicrystalline nanofibrils with alternating amorphous chains and nanocrystals.10 ManIn the present work, we demonstrate that monolayered chitin nanoribbons (ChNRs) can be facilely exfoliated from their natural ingredients through a one‐pot “tandem molecular intercalation (TMI)” process under mild conditions. Relatively small‐sized DMSO first intercalates into the interlayer space of chitin molecular sheets to trigger the gap‐widening and hydroxyl activation processes, and a subsequent influx of reactive intercalate molecules (esterification reagent) with larger size thoroughly delaminate the layered structures into single molecular layered nanoribbons. The substituent groups introduced by the above modification reagents should be specially designed to meet the following criteria: 1) its size should be large enough to thoroughly eliminate the interlayer interactions between chitin molecular sheets; 2) it should contain ionogenic groups to provide sufficient repulsive force for the delamination of layered structures and stabilization of ChNRs; 3) its polarity should be close to the pseudosolvent for the acquisition of satisfactory dispersibility. After reaching the above requirements, ChNRs with an unprecedented single molecular layer of >85% (thickness <0.6 nm) and a contour length up to several micrometers are directly exfoliated in the pseudosolvent, without any extra isolation, purification, and strong postmechanical disintegration steps. In comparison with nanometric ChNFs, the size reduction of ChNRs gives them greater similarity to chitin macromolecules; the monolayered nanoribbons show crystallization‐like assembly behaviors during the drying process. Even in the solid state , ChNRs also represent many unique performances that rarely observed in traditional ChNF‐based materials, such as plasticization via ethanol intercalation  and self‐welding with the assistance of trace DMSO. The desirable processing and welding characteristic as well as robust mechanical strength, satisfactory water stability, and biodegradability make ChNRs’ assembly promising candidates to partially substitute petroleum‐derived and hardly degradable plastic products .2Figure β‐chitin is first dispersed in the pseudosolvent of DMSO saturated with 1 mg mL−1 KOH under vigorous stirring. During this process, the pseudosolvent not only contributes to the high swelling and chemical activation of chitin by deprotonating its amide (—NH—CO—) and primary hydroxyl (—CH2—OH) groups, but also intercalates into the interlayer space of chitin molecular sheets to expand the (010) interplanar gap. The former provides an efficient and homogeneous reaction environment for the surface modification, while the latter ensures the accessibility of reactive intercalator to the surface of inner (010) crystal plane. After adding PA into the above chitin suspension, a surface esterification reaction and liquid self‐exfoliation occurred simultaneously within 15 min  are selected as representative starting material and reactive intercalator, respectively Figure 1A. Afteranar gap.14a Th3C cross polarization/magic angle spinning (CP‐MAS) solid state nuclear magnetic resonance (NMR) in Figure −1, —COO− (antisymmetric stretching) at 1578 cm−1, aromatic ester/acid (C—O symmetric stretching) at 1258 cm−1, and benzene (out‐of‐plane C—H bending) at 747 cm−1 in Figure  The ester linkage of the large‐sized benzoic group to the surface of chitin (010) plane, on the one hand, leads to the further expansion of interplanar gap and thorough disruption of interlayer interactions. The presence of ionizable benzoic group, on the other hand, enables surface anionization of chitin molecular sheets via the deprotonation of —COOH, thus offering sufficient electrostatic repulsion for the self‐exfoliation and stabilization of ChNRs. As a result, fibrillar chitin crystals delaminate to monolayered molecular sheet and immediately disperse in the pseudosolvent of DMSO/KOH, leading to the thinning and vitrification of the suspension  exhibit gel‐like rheological behavior where G′ is greater than G″ in the whole frequency range  at 169.4 ppm and aromatic ring (C10–C15) centered at 130.9 ppm of n Figure 15 Them Figure ; on the e Figure . Moreove While, a few regions show a larger thickness of 0.8–1.3 nm, indicating the presence of 2–3 layers of molecular sheet or overlapped monolayered ChNRs. Besides, the bending and twisting of nanoribbons can also cause the locally increment of the apparent thickness. Therefore, the average thickness of a single nanoribbon is measured from AFM images based on a count of ≈10 heights at different positions along its longitudinal direction  or DMSO dilution process, while without giving obvious aggregation  exhibit much poorer colloidal stability, which rapidly aggregate and become weak organogel within 1 day. Thus, the molar ratio of PA to chitin unit from 0.5 to 3 is selected to exfoliate chitin nanoribbons in the following works, and the products are denoted as ChNRs‐0.5–ChNRs‐3, respectively.The extraction conditions of ChNRs are further optimized, and its phase diagram controlled by swelling time in pseudosolvent and molar ratio of PA to chitin unit is illustrated in Figure Other chitin sources, such as loligo, eriocheir, portunid, and lobster, can also be utilized to produce ChNRs by experiencing the same extraction procedures, yet with different exfoliation yields Figure . These e17Figure d‐spacing widening of (010) plane, e.g., 2.0 Å for benzoic anhydride (BzA), 3.2 Å for butyric anhydride (BA), and even as high as 6.8 Å for octanoic anhydride (OA), respectively. However, these groups are hard to ionize and thus cannot provide enough driving force for the spontaneous delamination of chitin crystals, as well as indispensable repulsion force for the colloidal stabilization of exfoliated ChNRs. In the case of the latter situation, fibrillar chitin crystals also fail to self‐exfoliate to monolayered molecular sheet because the interlayer interaction is still dominated by the strong cohesion. The relatively weak electrostatic repulsion provided by deprotonated carboxyl groups can only slightly enlarge the d‐spacing of (010) plane  reflection peak completely disappears after modification, verifying the delamination of chitin crystals to monolayered molecular sheet Figure . HoweverFigure π‐stacking of benzene rings. Next, a successive process of vacuum filtration and air‐drying is applied to densify dispersive ChNRs to dense bulk aggregate. As shown in Figure −1 and synchronously strengthening of other peaks intensity in Figure d‐spacing (16 Å) is much higher than that of pristine β‐chitin (10 Å). Moreover, higher PA concentration utilized in the modification process tends to introduce more benzoic groups on ChNRs’ surface and hereby a higher crystallinity of the assembled film  measurements, where the incident beam parallel and perpendicular to the surface of the sample. As illustrated in Figure π–π interactions and thereby a better solvent (DMSO) resistance and mechanical strength of the film  , natural polymers , in spite of being more available, inexpensive, environmentally friendly, and biocompatible, lack essential processability for practical applications. Although the ChNRs’ films prepared in this work show layered structures with quite weak interlayer interactions, the superimposed cohesion, over the wide contact area, is still too strong for the effortless slippage of ChNRs, namely, poor deformability and processability of the film. Here, inspired by the plasticizing process of 2D graphene, small molecular solvent is selected to weaken the inter‐ChNRs’ interactions and thereby significant facilitation of their sliding motion ability.20 To  Besides 3D shapes, the alcoplasticity of ChNRs’ films can also be utilized for the production of highly oriented chitin films. The rearrangement of ChNRs to an aligned state is easily realized by slowly stretching the film in ethanol solution. After drying under room temperature, a series of uniaxial oriented chitin films are prepared with a draw ratio from 1 to 1.45. The ordered structures of these films are first evaluated using 2D WAXS measurement. As illustrated in Figure 1¯0), and (110) arcs are located on the perpendicular direction, clearly verifying the highly ordered arrangement of ChNRs   of single molecular layer (thickness <0.6 nm). In comparison with their nano‐counterparts (ChNFs), these ChNRs exhibit a series of unique properties owing to their sub‐nanometric size and rich surface functional groups. In the case of colloidal state, ChNRs are capable of coupling into single fusion mesocrystals and thus recovering their lowered crystallinity during the film‐forming process. The mesoscale‐assembled films also represent intriguing performances that rarely observed in traditional ChNF‐based films, such as plasticization via ethanol intercalation and self‐welding with the assistance of trace DMSO. The desirable processing and welding characteristics as well as robust mechanical strength, satisfactory water stability, and biodegradability make ChNRs’ assembly promising candidates to partially substitute petroleum‐derived and hardly degradable plastic products . The finding in this work not only offers a low‐cost, energy‐efficient, convenient, effective, and scalable platform for the production of high‐quality monolayered ChNRs, but also opens a new avenue for both the theoretical study and practical applications of organic SNMs.The authors declare no conflict of interest.Supporting InformationClick here for additional data file.


Proteus mirabilis was diagnosed. The bacterium analysed using genome sequencing and new strain called AJJ 2021 was diagnosed. This is the first report of pyoderma caused by Proteus mirabilis in sheep.Pyoderma is a purulent skin infection usually caused by bacteria and can be divided into primary and secondary categories based on histology. In the present study, an 18‐month‐old female mixed breed sheep was examined for pyoderma at the injection site of the enterotoxemia vaccine. After routine bacteriology and histopathology procedures, secondary pyoderma caused by  Proteus mirabilis) was examined at the injection site of the enterotoxemia vaccine.In the present study, an 18‐month‐old female mixed breed sheep with pyoderma (caused by new strain of  Pyoderma is classified into superficial and deep, depending on the level of tissue involvement . This animal had been previously vaccinated with the same vaccine at 3 months of age. With the exception of lesion and anorexia, all vital signs were within normal limits and all other physical examination parameters where normal.In February 2020, an 18‐month‐old female crossbred sheep was examined at Alian farm in Sorkheh city (Iran) for a skin lesion. This closed farm was in a desert area and had 170 breeding sheep. All animals were fed with hay (50%) and grain materials (50%) twice a day. Daily DM was 3%. The affected sheep was anorexic, but other animals had a normal appetite. There was no history of external parasites, itching and poor quality of the sheep external coating. In affected sheep, the skin lesion was located behind the scapula and was necropurulent in nature Figure . There w2.1Without any prior preparation, bacteriological specimens consisted of two pre‐sterile pre‐labelled cotton swabs were rolled over the centre of the lesion and placed into Cary‐Blair transport medium and sent to the laboratory in a cool box containing frozen ice packs. The collected samples were inoculated on blood agar  and purified bacterial isolates streaked on differential  and selective  media and incubated at 37°C for 24 h. All isolates were triply cloned to get new colonies for Gram staining, biochemical tests  and PCR. The antibiotic sensitivity test of the isolate was performed.2.2g for 10 min at 4°C. The pellet was washed once with saline solution. Finally, genomic DNA was extracted using a commercial DNA extraction kit for Gram‐negative bacteria according to the manufacturer's instruction . The 16S rRNA gene was amplified using related primers . PCR mixture was prepared using 12.5 µl of 2× Master Mix , 0.2 pmol of the primer (100 pmol/µl), 1 µl of template DNA (100 ng) and 9.5 µl of distilled water in a final volume of 25 µl. The reaction was carried out as follows; an initial denaturation at 95°C for 3 min, then 34 cycles of 95°C for 30 min, 58°C for 30 min, 72°C for 90 s and a final extension at 72°C for 7 min. The amplification products (5 µl) were resolved by electrophoresis on 1.2% agarose gel for 1 h at 90 V. Afterwards, the agarose gel was stained with ethidium bromide and screened using UV‐illuminator. The amplified products were approximately 1500 bp , and this sequence was submitted to the Bankit. The accession number is MZ314326.Isolated bacteria were cultured in TSB broth  and incubated at 37°C for 24 h. After that, 3 ml of TSB broth was centrifuged at 10,000 p Figure . Sanger 2.3Three samples (0/5×0/5 cm) were taken from the lesion margin with disposable biopsy punches and placed in 10% neutral buffered formalin and sent to the histopathological laboratory. The samples routinely processed, dehydrated, embedded in paraffin wax, sectioned at 5 µm in thickness using a rotary microtome  and stained with haematoxylin and eosin (H&E) for histopathological evaluation.2.4The distance between the animal and the veterinary diagnostic laboratory was distance (>300 km), for this reason empirical treatment was initiated and prescribed while diagnostic results were pending. The wool around the lesion was sheared and cleaned using sterile gauze impregnated with 0.9% sodium chloride sterile solution. The lesion was debrided of necrotic debris using tissue forceps. Topical therapies applied  to improve wound healing and treat infection, included 1% povidone iodine , 1% silver sulphadiazine ointment , 1% phenytoin sodium ointment  Figure . The was2.5Histopathologically, moderate epidermal hyperplasia, orthokeratotic and parakeratotic hyperkeratosis were observed. There was severe ulceration, fluid debris, cellular exudate, degenerate neutrophils, necrotic keratinocytes, and basophilic bacterial colonies were also present Figure . In the Proteus mirabilis. Proteus mirabilis was identified through differential and selective media, Gram‐staining and biochemical tests, as shown in Table Proteus mirabilis strain was characterised and in termed AJJ 2021.The underlying bacterial cause of the pyoderma was determined to be 2.6Proteus mirabilis was sensitive to dihydroestreptomycin sulphate and silver sulphadiazine. A positive response to treatment was observed and 2 weeks after the initial visit the lesion had the wound contracting  caused by Proteus vulgaris and Candida albicans in a 57‐year‐old woman with Castleman disease. The most common etiological agent of canine pyoderma is Staphylococcus pseudintermedius. The patient had suffered from recurrent pyoderma for years and underwent numerous treatments based on clinical findings without paraclinical examination. The cytology of the lesion made pyoderma suspicious. Bacterial culture, accurate identification of pathogens (Proteus vulgaris and Staphylococcus pseudintermedius) and treatment based on laboratory findings led to complete recovery was achieved with prolonged administration of fluorquinolones  were effective antibiotics and one (procaine penicillin) was ineffective antibiotics against isolated 4Proteus mirabilis can cause pyoderma in sheep and should be considered as a possible cause for pyoderma. The isolated Proteus mirabilis was sequenced for the 16S rRNA genome and registered as a new strain in the NCBI gene bank with code MZ314326 and AJJ 2021.This study showed that Mostafa Abdollahi: Conception, performing the experiment, writing the article. Ashkan Jebelli Javan: Conception and design, collecting the data, writing and revising the article. Sara Shokrpoor: Assistance in laboratory work. Mohammadhesam Beidokhtinezhad: Assistance in performing the experiment. Iraj Ashrafi Tamai: Assistance in laboratory work.The authors declare that there is no conflict of interest.There is no source of fund to declare.https://publons.com/publon/10.1002/vms3.926.The peer review history for this article is available at After sampling, the code of ethics in the research was taken from research committee of Alian Sheep Breeding Company (ethics code: 0061891274).The authors confirm that the ethical policies of the journal, as noted on the journal's author guidelines page, have been adhered to and the appropriate ethical review committee approval has been received.


Wars have hidden repercussions beyond the immediate losses of life, well-being, and prosperity. Those that flee wars and seek refuge in safer locations are not immune to the tragic impacts. Of particular concern is the susceptibility of the refugee populations to infectious diseases and antimicrobial-resistant pathogens. This poses a detrimental risk to these disenfranchised populations, who often have limited access to medical care, sanitation, and nutritious and safe food. Furthermore, antimicrobial-resistant pathogens in refugees can be both transmitted to and acquired from their hosting communities. The latter is particularly problematic when the host countries suffer from serious challenges such as limited resources, pollution, and widespread antimicrobial resistance (AMR). Here, we discuss AMR in refugees of the ongoing Syrian war, a conflict that resulted in the largest population displacement in recent history. We argue that Syrian refugees and their hosting communities are at an elevated risk of complicated and life-threatening AMR infections. We also call on the international community to address this grievous problem that threatens the disenfranchised refugee populations and can spill over across geographic borders to affect multiple countries. Multiple conflicts are currently unfolding across the globe. However, the protracted Syrian civil war resulted in the largest refugee crisis in recent history. Due to political and economic unrest and armed conflicts, Syrian civilians have been seeking refuge in different parts of the world. Of notable concern is the proliferation of infectious diseases that ruthlessly exploit the unprecedented humanitarian conditions created by the Syrian conflict –5. For eEnterobacterales, methicillin-resistant Staphylococcus aureus (MRSA), and drug-resistant tuberculosis  already existed in Syria before the conflict , 12. Altrculosis –22. TakeA global health response is needed to implement comprehensive effective policies and intervention strategies to tackle the scourge of AMR in major locations and camps that host the refugees. However, this cannot be achieved without a deep understanding of the current epidemiology of AMR in these locations. Therefore, we aimed here to evaluate the threat of AMR in the context of the Syrian crisis. We also highlighted the humanitarian situation and AMR challenges that the Syrian refugees are facing inside Syria and in host countries, with a special focus on Lebanon, a country that is currently hosting ~ 1.5 million refugees while facing its own challenges with high drug resistance trends –26 and cEscherichia coli, S. aureus, Klebsiella pneumoniae, Streptococcus pneumoniae, Acinetobacter baumannii, and Pseudomonas aeruginosa that exhibited resistance to multiple classes of critical antibiotics , AMR is growing and has become one of the greatest public health challenges facing humanity , 30. In ibiotics . These sThe problem of AMR is further complicated by a faltering research and development pipeline with only a few new drugs on the horizon. The latter is due to many factors, which are mainly related to pharmacoeconomics and the challenges, financial and otherwise, associated with discovering and bringing new antimicrobials to the market . For exahttps://www.unhcr.org/en-us/syria-emergency.html). Furthermore, the Syrian crisis has, directly and indirectly, affected several other countries in the Middle East and Europe. Notably, Turkey has been hosting the highest number of Syrian refugees (3.75 million), followed by Lebanon (~1.5 million), Jordan (0.67 million), Iraq (0.26 million), and Egypt (0.14 million). It is also estimated that one million Syrian asylum seekers and refugees have entered Europe, and the vast majority are hosted in Germany (59%) followed by Sweden (11%), while other European countries  host between one to five percent.Millions of Syrians have fled violence and persecution to seek safety as displaced individuals both inside and outside Syria. According to the current estimations of the United Nations High Commissioner for Refugees, more than two-thirds of the Syrian population have been internally displaced in Syria (~ 6.7 million) and/or fled the country and sought asylum abroad (~ 6.6 million), noting that there are large numbers of unregistered refugees that are not listed in the census , respectively  in Syrian refugee camps were described in Lebanon, highlighting the detection of OXA-48 and KPC carbapenemases in some colistin-resistant isolates , carbapenems (6%), tetracycline (94%), chloramphenicol (94%), fluoroquinolones (75–86%), and trimethoprim-sulfamethoxazole (92%). In another study, molecular analysis of MDR E. coli isolated from sewage water in Syrian refugee camps located in the Beqaa Valley revealed that 53.1% of isolates were positive for numerous resistance determinants -Ib, acc(3)-II, and Int-I1) , posing a risk of transmission to the hosting community  . The inf Lebanon . P. miraommunity .mcr-1-positive MDR E. coli detected in Lebanese irrigation water was high , amoxicillin-clavulanic acid (42%), cefepime (4%), cefotaxime (14%), cefalexin (46%), cefixime (17%), doripenem (0.3%), imipenem (0.5%), gentamicin (6%), kanamycin (9%), streptomycin (35%), tetracycline (35%), ciprofloxacin (10%), norfloxacin (7%), trimethoprim-sulfamethoxazole (32%), and chloramphenicol (13%)  . Of partTaken together, the susceptibility of refugee populations to AMR infections and their role in transmission of resistant pathogens across borders should not be viewed independently from the AMR trends in the hosting country. Again, the latter is especially true in LMICs that have widespread pollution and proliferation of AMR determinants. Stakeholders should be cognizant of the transmission dynamics of AMR in both refugees and the hosting countries ; otherwiThe healthcare system in Lebanon poses multiple challenges for refugees, including a lack of clarity, mistrust, discrimination, and limited and fragmented services. Although health services are in principle available for registered and unregistered Syrian refugees in Lebanon for an affordable fee , 13% of Since October 2019, Lebanon has been witnessing an unprecedented economic collapse and inflation, which were further exacerbated by the emergence of the COVID-19 pandemic. Lebanon has experienced a large epidemic expansion . Furthermore, the devaluation (> 90%) of the Lebanese pound has increased medical costs and pushed more than half of the resident populations, Lebanese and refugees, into extreme poverty. These populations have become unable to purchase personal protective equipment  or afford food and health services. Notably, Lebanon also relies heavily on imports to meet most of its food, energy, and medical needs . The inaGiven that the Lebanese government has immensely struggled to cope with the pandemic and provide care for Lebanese citizens, refugees were by default at heightened risk for SARS-CoV-2 infections. Weak public health interventions have been reported in refugee camps since the onset of the Lebanese economic crisis . United Displacement, dire living conditions, infectious disease, and AMR are real challenges that the Syrian refugees face on a daily basis. To prevent the exacerbation of these challenges and avoid catastrophic consequences on the refugees and their vulnerable hosting communities, engagement of stakeholders across the globe and investments in infrastructure and One Health approaches are critical. AMR surveillance systems and antimicrobial stewardship programs using genomic and machine-learning analyses are also needed to mitigate the sources of AMR affecting refugees and hosting communities and to optimize their access to necessary antimicrobials. International aid organizations must be cognizant of the transmission dynamics of AMR and play a key role in helping to implement reliable action plans to control AMR in both the refugees and hosting countries. The latter is critical in countries like Lebanon that suffer from limited resources and a variety of healthcare and economic challenges. It should be noted that the challenges discussed in this manuscript are not limited to Syrian refugees and can be experienced by other refugees such as the Rohingya, South Sudanese, and Congolese among others.The original contributions presented in the study are included in the article/supplementary material, further inquiries can be directed to the corresponding authors.MO and IIK contributed to the conception of the study and data acquisition and drafted the manuscript. IIK supervised the work. KC and KE critically revised the manuscript. All authors contributed to the article and approved the submitted version.MO is supported by the Atkinson Postdoctoral Fellowship (Cornell University). The work was partially supported by funds from the Center for Food Safety (University of Georgia).The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


Progress in the development of technologies for the real-time monitoring of neurotransmitter dynamics has provided researchers with effective tools for the exploration of etiology and molecular mechanisms of neuropsychiatric disorders. One of these powerful tools is fast-scan cyclic voltammetry (FSCV), a technique which has progressively been used in animal models of diverse pathological conditions associated with alterations in dopamine transmission. Indeed, for several decades FSCV studies have provided substantial insights into our understanding of the role of abnormal dopaminergic transmission in pathogenetic mechanisms of drug and alcohol addiction, Parkinson’s disease, schizophrenia, etc. Here we review the applications of FSCV to research neuropsychiatric disorders with particular attention to recent technological advances. Neuropsychiatric disorders such as drug or alcohol dependence, Parkinson’s disease, and schizophrenia have undergone decades of research, but their prevalence has not decreased. Mechanisms contributing to these disorders have yet to be fully delineated and this is still an area of ongoing research. Despite constantly enhancing earlier diagnostics, modern health care is still experiencing a deficiency of effective pharmacotherapies. Undoubtedly, the success in developing effective treatments depends on detailed understanding of the neurobiological mechanisms that trigger and promote these pathological conditions. Since dopamine neurotransmission plays a pivotal role in pathogenesis of diseases such as Parkinson’s, schizophrenia, drug abuse, and others, remarkable progress has been made toward understanding how aberrations in dopaminergic transmission impact these pathologies.In fact, development of pathology relevant animal models in parallel with the advance in monitoring of dynamic changes of neurotransmitters in the brain have provided researchers with a powerful toolbox for investigation in the neuroscience field. One of the most productive methodologies, which has been successfully used for many years, has become FSCV. FSCV was developed and popularized as a revolutionary technique to measure rapid changes of neurotransmitters at a biological time scale by Wightman and Millar in the 1980s as a logical continuation of the extraordinary efforts of the Adams’ group, which pioneered the application of electrochemical methods to quantify in situ endogenous catecholamines ,3,4. The general principle of electrochemical techniques, including FSCV, is based on oxidation and reduction of electroactive compounds when a certain potential is applied to the electrode, and measuring the resulting current. Differences in the ways in which the potential holds and generated current is measured provide benefits and limitations of certain electrochemical methods. The detailed comparison of technical aspects of FSCV with other commonly used approaches such as amperometry, high-speed chronoamperometry, and microdialysis has been provided in previous reviews ,7,8,9,10FSCV and high-speed chronoamperometry apply waveforms, triangle and square, and sample with the resolutions of hundreds of milliseconds, while amperometry holds constant potential, measuring a current at least an order of magnitude faster. Therefore, amperometry offers much better temporal resolution than other real-time electrochemical approaches including FSCV. However, the resolution of FSCV is still sufficient for monitoring fast fluctuation in extracellular dopamine, including naturally-evoked phasic dopamine effluxes observed in different behavioral paradigms on freely moving animals ,19,20,21Importantly, in contrast to FSCV and high-speed chronoamperometric measures, amperometry cannot provide information regarding the detecting analyte, since the current is measuring at fixed potential. The negative step in high-speed chronoamperometric measures allows this technique to establish a proportion between reductive and oxidative current that helps with analyte identification. FSCV shares with high-speed chronoamperometry this critical advantage in regard to a chemical resolution. Moreover, the use of background-subtracted voltammograms, which provide distinguishing current profiles within different potentials, affords FSCV an upgraded capability to reveal the identity of the detected substance. In contrast to amperometry, FSCV is sensitive to pH alterations, which are often associated with neuronal activation and therefore can contaminate the detecting signal. Nevertheless, based on the voltammogram, FSCV is capable to separate dopamine from pH changes. The special method was developed to statistically distinguish dopamine spikes using principal component regression . This apFSCV coupled to electrical stimulation is one of the few approaches comprehensively used to evaluate functional uptake of endogenous dopamine in brain slices and anesthetized preparations ,29,30,31By comparison, intracerebral microdialysis coupled with HPLC measurements, a technique with better chemical selectivity and sensitivity, can reliably determine basal extracellular concentrations of neurotransmitters. However, microdialysis probes are much larger than FSCV electrodes and thus create more damage to the brain tissue, and this approach does not have the advantage to measure detached release and uptake changes due to poor temporal resolution. Thus, microdialysis and FSCV focus on different aspects of neurotransmitter dynamics and these approaches have been widely used in parallel for decades ,37,38,39Drug and alcohol addictions, also called substance use disorders (SUDs), are chronic psychiatric conditions involving complex interactions between brain neurotransmitter systems, genetics, and environment. SUDs are characterized by uncontrolled substance seeking and taking behaviors, and long-lasting vulnerability to relapse. The key features of these neuropsychiatric pathologies can be reproduced in animal models including different paradigms of substance self-administration in rodents. Such models are widely used for the exploration of the neurobiological mechanisms underlying the development and escalation of addictions. A wealth of evidence demonstrated that altered dopamine signaling is involved in all stages of addiction, from initiation and maintenance to escalation and relapse . Due to Several critical factors were implicated for the development, shaping, and escalation of addictive behaviors. The first of them is a prominent brain response triggered by stimuli, which were previously associated with the exposure to abused substances. This response can be tightly linked with a desire and motivation to obtain a drug, while a learning function was equally proposed as well. The discovery that projections from the ventral tegmental area (VTA) to the nucleus accumbens (NAc) release dopamine at subsecond time scale during the presentation of cocaine-related cues in rats trained to self-administer the drug was made with the use of FSCV . MoreoveOther support for a possible role of phasic dopamine in promoting motivated behavior comes from voltammetric studies demonstrating that repeated cocaine exposure may increase cue-evoked motivation via augmented phasic dopamine release . FurtherAn alternative hypothesis postulates that phasic dopamine signaling may serve a teaching function, encoding the association between cues that predicted reward events and report errors in reward prediction. In fact, these postulates are based on compelling data ,17,43,44On the other hand, some progress was made in the understanding of the causative relationship between dopamine release and alcohol-seeking behavior. Using FSCV recordings coupled with the selective optogenetic activation of dopamine VTA-nucleus accumbens circuitry, it was confirmed that high and low frequencies may generate phasic and tonic increases in dopamine release, respectively ,47, whicA second factor that may play a key role in the escalation of addiction as well as in relapse is the neuroadaptation induced by chronic use of a drug. One of the important consequences of repeated increases in extracellular dopamine concentrations following prolonged exposure of addictive substances, including cocaine and alcohol, is an altered reuptake rate. FSCV coupled with electrical stimulation offers some advantages for the evaluation of these changes. Since the technique detects dopamine changes with subsecond resolution at micrometer-dimension probe, endogenous reuptake can be measured in real time with minimal tissue damage. Moreover, FSCV is able to resolve changes in dopamine uptake kinetically, separating changes in maximal uptake rate (Vmax) and Km parameters. The measurements can be performed in vitro, using brain slice preparations, and in vivo on anesthetized and freely moving animals.Due to the above-mentioned advantages of FSCV, the consequences of escalated cocaine self-administration  on dopamine uptake in rat nucleus accumbens were revealed. First of all, it was found that cocaine-induced dopamine uptake inhibition (changes in Km) reached a proportionally higher level during the loading phase of cocaine self-administration . CorrespIn parallel with in vivo findings, the rate of accumbal dopamine uptake (Vmax) measured with FSCV in brain slice preparation ex vivo was significantly increased following a 10-day binge of cocaine self-administration  . HoweverEx vivo FSCV was used to explore the consequences of chronic alcohol exposure on dopamine transporter-mediated uptake parameters. Thus, the acceleration in striatal dopamine uptake (Vmax) was observed in brain slices obtained from monkeys that were taking alcohol over a year , and in Considering DAT as the initial target, which is responsible for cocaine’s reinforcing action, the most intriguing results obtained with FSCV regarding neuroadaptations of presynaptic dopamine function are findings that DAT becomes less sensitive to cocaine inhibition following binge-like self-administration procedure ,31. AnalDue to its excellent spatial resolution (~6 µm × 100 µm), FSCV is capable of accurate monitoring of dopamine release changes in distinct brain subregions of freely moving animals. This advantage allowed Phillips’ group to discover hierarchical recruitment of phasic dopamine signaling in the striatum during the progression of cocaine self-administration. They carried out longitudinal subsecond dopamine detections simultaneously in the ventromedial striatum (VMS) and dorsolateral striatum (DLS) during the establishment of drug taking in rats . They deThe consequent question answered by the same researchers  was whetStress is the third factor with a well-established role in escalation and relapse of drug- seeking and -taking behaviors in SUDs that can be reproduced in the animal models. However, dopaminergic mechanisms by which stress impacts addictive behaviors are still unclear. The evolutionary significance of the brain response to stress is to orchestrate adaptations, which have been influenced by natural selection to mobilize the individual bodily abilities to optimally deal with situations that needs escaping action or defense (flight or fight). The increase in phasic dopamine detected with FSCV in the NAc of intruder rat during social defeat episodes  is perhaParkinson’s disease (PD) is a progressive neurodegenerative disorder that mainly affects the motor system with clinical manifestations occurring after the pathology reaches its advanced stage ,61,62. TAlthough PD has been intensively studied from a variety of aspects, there is no effective cure for PD, largely due to a lack of mechanistic understanding of its pathogenesis. It is still unclear whether a progressive degeneration of dopaminergic neurons is the sole causative mechanism occurring before clinical manifestation of PD, or whether there are concomitant losses in other neuronal systems, including the cholinergic system. The latter is known as also being progressively affected by the PD degenerative process ,68. The To explore a direct effect the presynaptic β2-containing nAChRs produce on dopamine release in the striatum during different patterns of nigrostriatal dopamine signaling, series of ex vivo FSCV studies utilizing rat and guinea pig brain slices were conducted ,78,79. BIn summary, so far, striatal dopamine slice FSCV demonstrated that activity in dopamine cell bodies is not an exclusive trigger for terminal dopamine release; striatal ACh acting at nAChRs on dopamine axons bypasses signal propagation in midbrain dopamine neurons by triggering terminal dopamine release directly. Thus, nAChR-active compounds may be implicated at least as adjunct therapies for PD, but more comprehensive studies are needed.FSCV was instrumental in uncovering alterations in dopamine neuronal functions in several transgenic animal models relevant to PD. Several studies were devoted to understanding the role of presynaptic protein alpha-synuclein in dopaminergic neurotransmission in the nigrostriatal dopaminergic system. Mutations in this protein are known to be linked to the pathogenesis of PD. Deficient evoked striatal dopamine release was documented in transgenic mice overexpressing mutated human A30P alpha-synuclein under the control of the promoter of prion-related protein , bacteriThus, an implication of FSCV into studies on mechanistic understanding of the pathogenesis of PD allowed for identification of novel compensatory maintenance of the striatal dopamine release suggestive of a functional reorganization of the presynaptic dopaminergic terminals in the early parkinsonian state. It is well-known that neurons of the dopaminergic system communicate under two modes, a fast “phasic” release (subsecond to second) and a slower “tonic” release (minutes to hours). Besides others, alterations in tonic dopamine levels are believed to be more critically important in enabling normal motor functioning, and dysregulation in tonic dopamine levels is believed to be causative to the development and progress of movement disabilities, which are crucial for PD. Therefore, the employment of neurochemical techniques that enable rapid, selective, and quantitative measurements of changes in tonic extracellular levels are essential in determining the role of dopamine in both normal and disease states. At present, electrochemical techniques for tonic dopamine concentration measurements notably encompass FSCV as one of the most preferred techniques due to its high spatial, temporal, and chemical resolution, as well as because of its great promise for the studies on disease neuropathogenesis in humans. Additional modified FSCV techniques have also been developed and become instrumental for measurements of tonic dopamine by the present time ,104,105.Unfortunately, these capabilities of the voltammetry to accurately evaluate changes in basal dopamine concentration are underappreciated so far. In fact, the use of the above-mentioned advantages could further benefit studies aimed to understand the mechanisms dysregulation in tonic dopamine transmission under the development of PD.For a more in-depth understanding of the advantages of FSCV for studies on dopamine in vivo, please refer to the substantial reviews on voltammetric measurements of brain neurotransmitters by Bucher and Wightman  and by BSchizophrenia is a complex devastating psychiatric disease of which pathogenesis has been debated for decades. It affects about 1% of the population worldwide and is manifested mainly by continuous or relapsing episodes of psychosis. Schizophrenia symptoms fall into three major categories: positive symptoms ; negative symptoms ; and cognitive deficits  . FollowiThe dopamine theory is supported by the observation that dopamine hyperactivity in the nigrostriatal and mesolimbic systems or hypersensitivity to dopamine underlies the symptoms of schizophrenia and psychosis ,130,131.A second major theory postulates glutamate NMDA deficiency in schizophrenia ,142,143.Another possibility of glutamate-dopamine interaction may involve mGluR-mediated mechanisms . PretreaFSCV was particularly instrumental in exploring other potential mechanisms in the pathogenesis of schizophrenia in various other experimental animal models. Administration of a neurotoxin which reduces DNA synthesis methylazoxymethanol to rodents on embryonic day 17 (E17) results in neurophysiological, cognitive, and functional brain changes, exhibiting symptoms of schizophrenia in animals ,149. ThiCholinergic regulation of dopamine function plays a key role in many behavioral manifestations ,153 and Despite long-lasting comprehensive fundamental and applied studies on neuropsychiatric diseases, modern medicine is still experiencing a deficit of effective pharmacotherapies. This is partly because the field needs better understanding of molecular and neural mechanisms that underlie the pathogenesis of brain diseases. From one side, it can be explained by a difficulty in the development of translational animal models for pathological conditions. From another side, previous achievements were dependent on the contemporary state of neurobiological technologies to analyze molecular mechanisms involved. Most detection systems used, at best, were limited in temporal and spatial resolutions as well as in their ability to conduct real-time analytical approaches on a system level. One successful technique, which is able to overcome those limits, is FSCV. Indeed, FSCV studies in animal models have provided significant insights into the role of altered dopaminergic transmission in neurochemical mechanisms of drug addiction, PD, and schizophrenia. Perhaps, the exploration of other neuropsychiatric pathologies such as attention deficit hyperactivity disorder, Alzheimer’s disease, and Tourette’s syndrome in relation to dopamine abnormalities could also benefit from FSCV. For instance, just a few animal studies on Alzheimer’s disease have reported on utilization of FSCV so far ,162. SimA new promising application of FSCV has started in pre-clinical and clinical studies. Nowadays, a number of research teams have pioneered in vivo FSCV studies on the human brain and have made encouraging efforts to bring FSCV to patients ,167,168.Finally, FSCV is a constantly and rapidly progressing technique. Recent advances include novel electrode technologies that enable more sensitive, less damaging, long term and wireless recordings, optimized data processing and enhanced analyses. However, future developments demand a combining of FSCV with other leading-edge technologies, such as multisite detection and machine learning . Consequ