The 2016–2017 Central Italy earthquake sequence struck the central Apennines between August 2016 and October 2016 with Mw ∈ , plus four earthquakes occurring in January 2017 with Mw ∈ . We study Global Positioning System time series including near‐ and far‐field domains. We use a variational Bayesian independent component analysis technique to separate the post‐seismic deformation from signals caused by variation of the water content in aquifers at hundreds of meters of depth and of the soil moisture. For each independent component, realistic uncertainties and a plausible physical explanation are provided. We focus on the study of afterslip on the main structures surrounding the mainshock, highlighting the role played by faults that were not activated during the co‐seismic phase in accommodating the post‐seismic deformation. We report aseismic deformation occurring on the Paganica fault, which hosted the Mw 6.1 2009 L'Aquila earthquake, suggesting that static stress transfer and aseismic slip influence the recurrence time of nearby (∼50 km further south of the mainshocks) segments. A ∼2–3 km thick subhorizontal shear‐zone, clearly illuminated by seismicity, which bounds at depth the west‐dipping normal faults where the mainshocks nucleated, also shows aseismic slip. Since afterslip alone underestimates the displacement in the far‐field domain, we consider the possibility that the shear zone marks the brittle‐ductile transition, assuming the viscoelastic relaxation of the lower crust as a mechanism contributing to the post‐seismic displacement. Our results suggest that multiple deformation processes are active in the first 2 years after the mainshocks. We study the post‐seismic deformation following the 2016–2017 Central Italy seismic sequence through Global Positioning System displacement time seriesWe map the afterslip distribution on faults co‐seismically activated and we investigate interaction among faultsWe infer the occurrence of multiple post‐seismic deformation mechanisms including afterslip and viscoelastic relaxation The proper modeling of these various contributions is an active research domain of solid Earth sciences. In practice, we aim at isolating the deformation signals relative to the various mechanisms contributing to the observations. In this sense, we are facing a so‐called blind source separation problem, as we will detail in Section 2.2M of displacement time series relative to sensors distributed at different locations in space, we can organize the data into a spatio‐temporal matrix X. In particular, we organize it in such a way that each row is a different time series, and each column represents the record at a given time or epoch. The data at our disposal has a daily sampling in time and spans the time range 2012–2019. The total number of stations used in the analysis is 85. Since we have three‐dimensional records , the matrix X has size M × T = 255 × 2525. A well‐established approach to deal with the separation of the sources contributing to the observed deformation consists in the application of multivariate statistical techniques that attempts to maximize the independence of the sources generating the observations. The techniques fall under the umbrella of the ICA and typically consist in a linear decomposition of the data into a mixing matrix A (M × L) and a source matrix S (L × T), with the L sources (components) being as much independent as possible. We can cast the problem in the following terms:N is noise . Given the data X the goal is to find the linear mix of independent sources that generated the observations. We underline here that the equality holds if we use a number of components L sufficient to span the whole original space where the data X lives. A truncation is typically performed, that is, L < min{M,T}, and the right hand side is a low‐rank approximation of the left hand side  and a temporal evolution (V). A weight coefficient Σ (in mm) is required to rescale the contribution of each component in order to explain the original displacement data set. Since the vbICA belongs to the field of linear decompositions, we can write the result of the decomposition of the data matrix X as:Unfortunately, the independence condition is not straightforward to impose and approximations are introduced in order to generate a suitable cost function to minimize or maximize. To achieve this, several approaches have been proposed and here we use a variational Bayesian ICA (vbICA). It has been shown that this method is superior to other widely used ICA techniques because it offers more flexibility in the description of multimodal sources and it allows us to take into account missing data . The configuration is such that we look for independent signals in the time domain, that is, the sources correspond to the columns of the V matrix while the mixing matrix is given by the product UΣ. The vbICA algorithm models the probability density function of each source via a mix of Gaussian distributions  is determined by performing statistical tests such as the F‐test  is shown in Figure U) is shown in Figure U1 spatial pattern is rather clear, consistently with the extensional mechanisms of the seismic sequence. U2 shows a clear vertical motion, with all stations moving coherently up and down with annual periodicity, whereas U3 and U4 show more complex horizontal, and vertical, spatial patterns. In the next section, we will provide a physical explanation for the second, third, and fourth components, whereas the first component will be discussed in Section The temporal evolution of the four ICs  time‐interval as in Vičič et al. , in orde3In this section, we discuss the deformation signals associated with the second, third, and fourth ICs Figures  and 4, p3.1IC2 represents a common mode annual signal, with a uniform spatial response  in the vertical component, describing uplift of the GPS network as temperature rises and subsidence when the temperature decreases. Seasonal vertical displacements are interpreted in the literature as caused by loading due to mass redistribution in the shallow Earth crust and surface  is the afterslip spatial distribution along the strike and the dip directions. The inversion follows the least squares formulation of Tarantola  calculated with the procedure described in Section mdip ≤ 0). We follow the formalism of Radiguet et al. . The regularization parameters  associated with each fault depend on the dimension of the fault itself, therefore a unique set of values cannot be selected for the whole fault system. They are fixed seeking the best compromise between a physically acceptable solution  and the misfit with the data, and they resulted in a λ = 2 × λ0 and a priori standard deviation σm = 0.71 for the M. Vettore and its antithetic fault and σm = 1 for the Campotosto and the Paganica faults.For the slip inversion, we follow the conceptual scheme proposed by Kositsky and Avouac  and adaparantola  for linet et al. , using a4.2The resulting afterslip distribution solution is shown in Figure This model shows the occurrence of slip on the deepest portion of the M. Vettore fault below the co‐seismic ruptures of the Amatrice and Norcia earthquakes, with a maximum slip >40 cm and a prevalent normal mechanism Figure , while bAs it can be observed from Figure 4.32  on its deepest edge Figure . The eas4.4From Figure λ = μ = 30 GPa) that overlays the lower crust and the lithospheric mantle located below 33 km depth , which shows a prevalent NE‐SW horizontal deformation signature, consistent with the direction of the tectonic deformation in this area Figure . The vbI(i)In terms of afterslip, since the 2016–2017 seismic sequence was characterized by several mainshocks, describing their post‐seismic phase only through the IC1 means that we cannot get any insight into the possible spatial migration or different activation times of the different faults involved in the seismic sequence. Our analysis is limited to a stationary spatial response of the slip, not allowing us to determine when the different parts of the faults actually began to slip.(ii)Three mechanisms primarily drive the post‐seismic relaxation of stress: afterslip, poroelastic rebound, and viscoelastic flow. In this study, we considered at least two of them (afterslip and viscoelastic flow) to be active, but having a single IC representing the post‐seismic response does not allow us to account for them separately.As mentioned in Section Poroelastic rebound effects on surface displacement are usually confined in near field regions where the afterslip contribution to the post‐seismic deformation is also dominant  that corresponds to a Mw 6.5. In order to compare this with the seismic moment released by aftershocks, we consider the seismic catalog described by Michele et al.  is e et al.  and conve et al.  for smal Figures  and 9c.  Figures , a first5.2ηlc = 5 × 1018 Pa s and about 18–22 km of thickness for the lower crust, we obtain a displacement field consistent with the geodetic observations. Such setting . As a matter of fact, a trade‐off between the thickness of the viscoelastic layer and its viscosity exists. Pousse‐Beltran et al.  with respect to the typical time scales of viscoelastic processes (∼5 years for the inferred viscosity of this area), bearing also in mind that moderate events (such as the Mw 6.5 Norcia earthquake) lead to deformation rates in the order of few mm/year  accommodated cm‐scale slip in the post‐seismic phase, mainly aseismically, highlights how interaction among faults has to be taken into account while attempting a deterministic modelization of the earthquake cycle.Given the afterslip concentration at the base of the seismogenic faults, the different temporal evolution of geodetic deformation and cumulative number of aftershocks and the discrepancies between measured and afterslip‐modeled displacements, a viscoelastic contribution to the observed post‐seismic ground displacements cannot be ruled out. In particular, we deem the relaxation of the lower crust to be a contributing mechanism in the 2 years following the Amatrice‐Visso‐Norcia seismic sequence. Bearing in mind the limits of the data and of our interpretation, we propose an afterslip model that is consistent with the co‐seismic ruptures on the structures involved in the 2016–2017 seismic sequence. Furthermore, we provide some preliminary values of the viscosity and thickness of the lower crust, leaving further investigations to future studies, which might consider an afterslip + viscoelastic joint inversion of possibly longer time series.Supporting Information S1Click here for additional data file.


During our search for novel myxobacterial natural products, we discovered the thiamyxins: thiazole‐ and thiazoline‐rich non‐ribosomal peptide‐polyketide hybrids with potent antiviral activity. We isolated four congeners of this unprecedented natural product family with the non‐cyclized thiamyxin D fused to a glycerol unit at the C‐terminus. Alongside their structure elucidation, we present a concise biosynthesis model based on biosynthetic gene cluster analysis and isotopically labelled precursor feeding. We report incorporation of a 2‐(hydroxymethyl)‐4‐methylpent‐3‐enoic acid moiety by a GCN5‐related N‐acetyltransferase‐like decarboxylase domain featuring polyketide synthase. The thiamyxins show potent inhibition of RNA viruses in cell culture models of corona, zika and dengue virus infection. Their potency up to a half maximal inhibitory concentration of 560 nM combined with milder cytotoxic effects on human cell lines indicate the potential for further development of the thiamyxins. The chemical structure and absolute stereochemistry of an unprecedented natural product family, the thiamyxins, is presented. These thiazole‐ and thiazoline‐containing cyclic depsipeptides are produced by a nonribosomal peptide synthetase‐polyketide synthase hybrid biosynthetic gene cluster, whose structure is described herein. The thiamyxins were found to exhibit promising antiviral activity against three different RNA viruses. The severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) that was first identified in December 2019 in Wuhan, China, is the cause for the ongoing COVID‐19 pandemic that is challenging global health administrations in an unprecedented way.Myxococcaceae strain MCy9487, towards their biosynthetic potential to produce biologically active NPs. In this manuscript, we report the structure of a family of unprecedented cyclic depsipeptides produced by this strain, which we called the thiamyxins, alongside the determination of their stereochemistry and biosynthesis, as well as their intriguing activities against RNA viruses.Bacterial natural products (NPs) represent an ubiquitous source of novel chemistry, coming with a diverse range of biological activities.Myxococcaceae isolated from soil of the Saarland University campus. Phylogenetic analysis based on 16S RNA revealed the strain's distinct position within the Myxococcus‐Pyxidicoccus‐Corallococcus clade. Due to its yet unclassified genus and the interesting inhibitory activity profile (Table S1) of the crude extract, it was prioritized for chemical in depth‐analysis. High performance liquid chromatography—high resolution mass spectrometry (HPLC‐hrMS) analysis of the MCy9487 crude extract and nuclear magnetic resonance spectroscopy (NMR) analysis of prefractionated crude material, revealed a family of at least four putatively novel NPs. hrMS isotope pattern and NMR signal shifts indicated peptide type structures with some striking characteristics including thiazole and thiazoline substructures  MS and detailed configurational analysis, prior to evaluation of their biological activities against a broader panel of pathogens, including a panel of human pathogenic viruses.MCy9487 is a myxobacterial strain of the family s Figure . Isolate43H59N9O8S4 based on hrMS data. Interpretation of the 1D and 2D NMR spectra, alongside with their characteristic MS2 fragmentation pattern, revealed all thiamyxins to consist of the following peptide sequence: 2‐(hydroxymethyl)‐4‐methylpent‐3‐enoic acid(HMMP)‐(Ala)‐(Ile)‐methylthiazoline(Me‐thiazoline)‐thiazole‐Me‐thiazoline‐dehydroalanine(Dh‐Ala)‐O‐methylserine(O‐Me‐Ser)‐N‐methylvaline‐thiazole.Thiamyxin A and B were assigned a molecular formula of C1 and B 2 to be diastereomers. Specific fragment connectivity was obtained for all derivatives by detailed analysis of homonuclear and heteronuclear 2D NMR data (see Supporting Information). The characteristic chemical shift of the HMMP methylene in 1 at δH 4.90/4.86 and δC 67.0 ppm, alongside with its HMBC correlation to the thiazole carboxy function (δC 160.5 ppm) implies cyclization between the C‐terminal thiazole and the HMMP primary alcohol. The HMBC correlation in 2 (δH 4.81/4.92 and δC 65.9 ppm to δC 160.4 ppm) is consistent with the finding for 1. In contrary, thiamyxin C 3 shows a shielded chemical shift at this position of δH 4.00 and δC 63.1 ppm. This signal, in contrast to the corresponding signal in 1 and 2, does not show any scalar coupling, indicating free rotatability of the HMMP methylene . Together with the assigned molecular formula (C43H61N9O9S4), thiamyxin C 3 was determined to be the ring open congener of 1 and 2. The molecular mass of thiamyxin D 4 is further increased by C3H6O2 when compared to 3 and the chemical shift of the HMMP methylene only shows a deviation of 0.1 ppm for δC and an exactly matched δH compared to 3, affirming that thiamyxin D also belongs to the open chain derivatives. Thorough analysis of the 1D and 2D NMR spectra (Tables S4–S7) finally revealed, that this derivative features an additional glycerol unit attached to the C‐terminal carboxyl function .The occurrence of two thiazoline and two thiazole moieties was recognizable and eponymous for the thiamyxins . The configuration of the Me‐thiazoline moieties were assigned by comparison to thiangazole, wherein all Me‐thiazoline units previously were described to be derived from R‐configured 2‐Me‐cysteine.R‐configured as well. We observed demethylation of N‐Me‐Val under acidic conditions, wherefore the emerging Val was compared to a Val standard to assign the stereochemistry of this amino acid . The stereocenter of N‐Me‐Val was hereby assigned as S‐configured. Additional NMR signal sets were detected for both cyclic derivatives 1 and 2, in particular located surrounding the N‐Me‐Val signal sets. The ratio to the main signal set was constant (ca. 1 : 5) in both derivatives and in different isolated batches, indicating two conformational isomers even though NMR experiments at different temperatures and solvents did not yield a significant change of the conformer ratio . The Ile stereocenter was found to racemize during hydrolysis, which could not be prevented by optimizing the conditions. Similar effects were observed previously for stereocenters adjacent to thiazoline moieties in the bottromycin biosynthesis and the synthesis of peptide thiazolines. We believe that racemization is promoted by the neighboring Me‐thiazoline in the thiamyxins.R‐configured (see below). After careful analysis of the 2D NMR data, the corresponding signals revealed that thiamyxins 1 and 2 are diastereomers. Configurational assignment was achieved based on observed shift and coupling constant differences of isoleucine vs. allo‐isoleucin .1) and thiamyxin B (2) are epimers in the 2‐Ile stereocenter. According to the high prevalence of l‐Ile in natural products, we assume thiamyxin A (1) to incorporate l‐isoleucine and thiamyxin B (2) d‐allo‐isoleucine, respectively. The open chain derivative 3 turned out to be a mixture of both isomers (ca. S : R 1 : 2 according to NMR) with exactly matching retention time on HPLC. The same holds true for thiamyxin D (4).The stereochemical configuration of the individual aminoacids was elucidated using Marfey's method.thiA‐thiH), as well as a cytochrome P450 dependent enzyme and a thioesterase domain encoded on thiI and thiJ, respectively. During bioinformatic analysis of the cluster we also found a fragmented but similar biosynthetic gene cluster in Corallococcus terminator, previously identified by Livingstone et al.AntiSMASH analysis of the MCy9487 genome enabled identification of a PKS‐NRPS hybrid gene cluster capable of thiamyxin biosynthesis Figure . It consl‐methionine‐(methyl‐13C) indicated up to seven methyl incorporations into thiamyxin C, whereas feeding with l‐valine‐d8 resulted in only one incorporation which is explained by the N‐methylvaline incorporated by module 11. Thus, no second valine seems to be incorporated as would be expected if isovaleryl‐CoA formed from valine was the starter moiety. When feeding methionine‐(methyl‐13C), five of the observed incorporations can be accounted for by methyltransferases in modules 2, 6, 8, 10 and 11. To account for the remaining two methyl incorporations, we propose, that malonyl‐CoA is bis‐methylated to form dimethylmalonyl‐CoA. A conserved domain search of the thiA gene, revealed a dimerization domain directly upstream of the GNAT domain. This dimerization domain is commonly found in methyl transferases.The polyketide biosynthesis in thiamyxin is initiated by a GNAT domain. These domains have been shown to initiate polyketide biosynthesis by starter unit selection and decarboxylation, for example in the biosynthesis of the cytostatic polyketide gephyronic acid, as well as myxovirescin, rhizoxin, curacin and pederin.thiI. This hydroxylation is required to take place on the assembly line as the resulting hydroxy group is necessary for final cyclization by the type I thioesterase located on thiJ. Modules 3 and 4 contain epimerization domains, which indicates that these incorporate d‐Ala and d‐Ile. Module 5 consists only of a C and a PCP domain and does not incorporate any building block, although the C domain seems to be functional based on analysis of its active site residues (see Supporting Information). The C domain is annotated as a DlC domain, which are responsible for forming amide bonds with d‐amino acids. As the previously incorporated amino acid is d‐Ile, we propose that this C‐domain has a transfer function that assists in loading of the intermediate onto the PCP‐domain of the next module 6. In module 6, a heterocyclization domain (HC) catalyzes the first cysteine incorporation followed by cyclization and methylation to form Me‐thiazoline as previously described in the bacillamide E biosynthesis.thiG and thiH. This module introduces a thiazole, analogous to module 7. The TE domain encoded on thiJ, finally releases the molecule from the assembly line by cyclic condensation with the hydroxyl function installed by the CYP‐450 in module 2. The derivative thiamyxin D likely is a shunt product, created during the release process. We propose that the type I TE domain promiscuously accepts glycerol as substrate next to the HMMP‐hydroxy function required for the intramolecular cyclization reaction. Similar glycerol ester formation has been previously observed in tubulysin biosynthesis.2O but could also be an artefact from the purification process. Downstream of the TE Domain a KS and PCP di‐domain are encoded on orf5. Analysis of their active site residues revealed them to be non‐functional, which is in line with our biosynthesis hypothesis, as there are no non‐assigned biosynthetic reactions remaining to form the mature thiamyxins.Dimethylmalonyl‐ACP is then decarboxylated by the GNAT and transferred to module 2.−1 against two fungal test organisms  and two Gram‐positive pathogens (Bacillus subtilis and Micrococcus luteus) (Supporting Information‐Table S3). Thiamyxin D did not show effects in the tested concentrations.After determination of their chemical structure, the thiamyxins were evaluated against a broad panel of bacterial, fungal and viral pathogens, alongside with their antiproliferative effects on human cell lines (Table −1 isolated yield) and represent one cyclized and one open chain analogue were evaluated for activity in cell‐based assays against the human pathogenic corona virus hCoV‐229E and two representatives of the flavivirus genus, Dengue virus and Zika virus, for which we used the easy to measure reporter viruses hCoV‐229E‐luc, DENV‐R2A and ZIKV‐H/PF/2019, respectively.−1 isolated yield, thiamyxin A and D were only evaluated against a selected panel of test organisms.Thiamyxin B and C which are produced in higher amounts (0.6 and 1.4 mg L50) in the low micromolar range. This activity was highly decreased for the open chain analogues thiamyxin C and D, which showed IC50 values above our tested concentrations of around 20 μM.The cyclized congeners thiamyxin A and B were found to effectively inhibit hCoV‐229E‐luc with a half maximal inhibitory concentration . Determining the thiamyxins’ antiviral target ‐ besides developing a total synthesis route for them ‐ could provide deeper insight into the thiamyxin pharmacophore and help to understand these observations.In this study, we present the thiamyxins, a family of cyclic thiazole‐ and thiazoline rich non‐ribosomal peptides, which we isolated from the myxobacterial strain MCy9487 discovered at the Saarland University campus. A combination of NMR analyses and detailed stereochemical configurational studies supported by bioinformatics analysis of the BGC responsible for their formation led to their complete stereochemical assignment. We developed a concise biosynthesis model for the thiamyxins, including the formation of their unusual isobutyryl starter unit, which presumably is formed in a similar fashion to gephyronic acid. Based on the underlying biosynthetic logic, thiamyxin B seems to be the main product of the thiamyxin BGC assembly line, which is also reflected in its higher production rate compared to thiamyxin A. The two open chain analogues thiamyxin C and D likely are shunt products, generated due to promiscuity of the release enzyme for gylcerol and water in competition with the preferred intramolecular HMMP‐hydroxy function. Thiamyxin B also shows the most potent biological activity among the four characterized derivatives. It shows significant activity against RNA viruses but also shows cytotoxic effects, which however seem to be cell‐line‐dependent and can be well separated from the observed antiviral activity. Due to the comparably low production rates of the thiamyxins, biotechnological production optimization, biosynthetic engineering approaches or development of a total synthesis route would be of great interest allowing their in‐depth evaluation against a broader panel of human pathogenic viruses and studying their cytotoxicity profile on non‐infected human cells. Those approaches would furthermore allow access to further derivatives, giving insight into structure‐activity relationships of the thiamyxins and enabling evaluation of the pharmacokinetic properties of this interesting NP class. In this study, we could already observe significantly lower antiviral activities for the open‐chain analogue thiamyxin C as compared to the two cyclic thiamyins A and B, but the data still suggest some residual antiviral activity at higher micromolar concentrations. This finding is particularly interesting, as most cyclic NRPs almost completely lose affinity to their target because their 3D structure is altered by opening the macrocycle. The resembling biological activities of thiamyxin A and B are unexpected, as their proposed incorporation of In summary, the thiamyxins are a structurally unique class of NPs showing a potential application window as broad spectrum antivirals targeting human pathogenic RNA viruses and their desription herein paves the way for their further investigation.The authors declare no conflict of interest.1As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed and may be re‐organized for online delivery, but are not copy‐edited or typeset. Technical support issues arising from supporting information (other than missing files) should be addressed to the authors.Supporting InformationClick here for additional data file.


Chronic neurodegenerative diseases encompass a wide spectrum of disorders and affect millions of people worldwide. These diseases are characterized by progressive axonal loss that ultimately leads to apoptosis and consequently to neuronal death . In the Recent advances in the field of motor neuron diseases shed light to various underlying mechanisms implicated in their pathophysiology and revealed several useful biomarkers; nevertheless, no radical change has been observed in the clinical course of these diseases . AlthougSimilarly, non-pharmacological approaches may also ameliorate the quality of life of people living with other neurodegenerative conditions. One such approach is neurorehabilitation, which has proven to be a significant tool in the treatment of brain damage . In thisDementia is one of the most common and detrimental manifestations of neurodegeneration. Extensive research focusing on the detection of biomarkers and potential risk factors for the development of dementia is being conducted . ArtificNeurodegeneration is now at the center of focus of current research in multiple sclerosis and it is considered to be a major contributor in the accumulation of disability in these patients . TherefoThis Special Issue provides an interesting collection of articles focusing on early detection and management of various neurodegenerative diseases. We anticipate and we hope that in the near future, neurodegenerative diseases will be better understood and more efficiently treated. Nevertheless, further research is needed in order to achieve our goal which is to provide better care for our patients.


Sarcoptes scabiei var. hominis, a small mite that performs its whole life cycle within the epidermis. In this case report, we provide images of the sonographic signs of scabies. We found that the adult mite can be seen as a hyperechoic well-defined ovoid area within the epidermal layer at the end of the hypoechoic burrow, while the eggs correspond to tiny heteroechoic dots along the burrow. In conclusion, ultrasound may prove useful to differentiate between inhabited vs non-inhabited scabiotic burrows.Scabies is a cutaneous infestation caused by  Sarcoptes scabiei var. hominis. It presents as a very pruritic exanthem, with erythematous papules and excoriations. Since many other skin conditions can be pruritic, the diagnosis is often made by observing the burrow made by the female mite. This burrow though, is not always visible in all patients with scabies. Burrows can be easily confused with the scratches caused by pruritus, even with the aid of dermoscopy. Thus, ultrasound could prove a useful tool in its diagnosis by helping to recognize mites in the epidermal layer [Scabies is a skin condition caused by the infestation with al layer , 2.A 51-year-old man presented to our Dermatology department with a history of very pruritic skin lesions that had appeared 1 month prior to consultation. He lived alone. No new drugs were initiated the months prior to this episode, and the only drug he episodically took was acetaminophen for headaches. He reported that pruritus worsened during night and affected the whole body, sparing the head.TM9 platform (Esaote). A copious amount of gel was used, and the probe was placed longitudinally along the burrow that we had previously identified with dermoscopy.Dermatological examination showed erythematous papules in trunk, legs and arms. Erythematous nodules were present in the scrotum. Mucosae were not affected. With dermoscopy, a scabiotic burrow with the “jet with a contrail” sign and the “triangle” sign was seen in the volar aspect of the left wrist Fig. . We thenWe could observe in the site with the “triangle” sign a hyperechoic well-defined ovoid area within the epidermal layer Fig. A. The buScabies is a skin disorder that severely affects patients due to intense pruritus. It is sometimes misdiagnosed due to the inability of correctly recognizing scabiotic burrows, as they are easily mistaken with scratches caused by other pruritic conditions , 2.Dermoscopy helps us differentiate some of these scratches from actual burrows, as a burrow can be seen as a wavy, hyperkeratotic, greyish-white tunnel-like structure –5.The term “jet with a contrail” sign refers to a scabiotic burrow seen in dermoscopy with a black triangle at one end. This black triangle is also called the “triangle” sign, it is a pathognomonic sign of scabies and allows us to make a diagnosis without the need for a biopsy or a skin scraping. It also points out the exact location of the female adult mite. But not every burrow can be correctly recognized with dermoscopy alone, as many of them may lack this sign or other dermoscopic criteria –5.With the aid of sonography, we could correctly assess those dermoscopically-unspecific burrow-like structures, to verify the presence or absence of adult mites.This is not only useful as a means to perform a correct diagnosis, but also for assessing that treatment was performed correctly. After a correct treatment and resolution of the disease, pruritus can persist for a month , making There are no previous reports on high frequency ultrasound of scabies as far as we know. We propose high frequency ultrasound, as a non-invasive, new, complementary diagnostic method in scabies in cases in which clinical examination or dermoscopy are non-conclusive.


N‐acylhydrazole bonds with Lawesson's reagent (LR). The as‐prepared thiadiazole‐linked COFs not only remain porosity and crystallinity, but enhance its chemical stability. Furthermore, thiadiazole‐linked COFs are more favorable to lower exciton binding energy and promote π‐electron delocalization over the whole reticular framework than N‐acylhydrazone‐linked COFs. Notably, the extended π‐conjugation structure and decent crystallinity of the resulting TDA‐COF are reflected by its higher photocatalytic H2 evolution rate (61.3 mmol g−1 in 5 h) in comparison with that (7.5 mmol g−1) of NAH‐COF.The establishment of facile synthetic routes to engineer covalent organic frameworks (COFs) with fully conjugated structure and excellent stability is highly desired for practical applications in optoelectronics and photocatalysis. Herein, a novel linkage conversion strategy is reported to prepare crystalline thiadiazole‐linked COFs via thionation, cyclization, and oxidation of  2 production. They serve as ideal platforms for understanding structure‐activity relationships toward the water‐splitting in the thiadiazole‐based polymer, which provide a new insight to rational design of COFs‐based photocatalyst for photocatalytic H2 production.A facile and general strategy is developed to prepare thiadiazole‐linked covalent organic frameworks for photocatalytic H A series of functional COFs have been constructed and widely applied in the field of gas adsorption, optoelectronics, catalysis, sensor, and so on. To develop advanced COF‐based materials in these fields, previous strategies mainly concentrate on the molecular design of the knot or linker with a specific linkage. In addition to building blocks, however, linkage can also have a crucial effect on the stability, electronic structures, and morphologies of COFs materials. Over the past decades, there have been various covalent linkages used for the synthesis of COFs, such as benzoxazole, imidazole, dithiine, thiazole, indazole, and so on. However, high‐quality crystalline structures are usually achieved through the utilization of reversible covalent bonds in COFs. For instance, imine‐ and hydrazone‐linked COFs with partial π‐conjugation structure are reversibly formed by Schiff‐base reaction. Although the dynamic property of reversible covalent bonds offers a solution to the crystallization problem of COFs through error‐correction and self‐healing mechanism, the inherent reversibility and strong polarization of chemical bonds could result in bad chemical stability and blocked π‐electron delocalization throughout host networks. To improve chemical stability and optimize photoelectronic properties of COFs, it is significant to expand the synthetic toolbox and construct COFs linked by irreversible and fully conjugated linkage.Covalent organic frameworks (COFs) are a newly emerging class of crystalline porous materials synthesized by connecting various aromatic building blocks via covalent bonds.1 The  Consequently, thiadiazole as a novel linkage in COFs will be encouraging by virtue of high chemical stability and superior electron transport ability. However, rapidly irreversible formation and cyclization of diacylhydrazines commonly result in amorphous thiadiazole‐based materials  heterocycle, containing high electron affinity ability, great aromaticity, as well as excellent thermal and chemical stability, are extensively utilized in medicinal, organic electron, and optoelectronic chemistry.29 Cons Scheme .[35]N‐acylhydrazone based‐COFs through thionation, cyclization, and oxidation of N‐acylhydrazone motifs using Lawesson's reagent (LR) as the thionating reagent. The thiadiazole was first introduced into COFs as a new linkage. Given the unique fully conjugated molecular structure and excellent chemical stability, the resulting COFs could demonstrate enormous potential as a semiconductor material for photocatalysis. Significantly, TDA‐COF displays excellent photocatalytic H2 evolution performance of 61.3 mmol g−1 in 5 h under visible‐light irradiation, which obviously outshines the 7.5 mmol g−1 of NAH‐COF under the same condition.As a proof‐of‐concept study, herein, we present a novel synthetic strategy for thiadiazole‐linked COFs from 2Figure  N‐acylhydrazone units in NAH‐COF into the fully conjugated thiadiazole linkage via LR in toluene afforded TDA‐COF. To showcase the broad potential of this method, two other N‐acylhydrazone linked COFs, NAH‐COF‐42 and NAH‐COF‐THz, were prepared and transformed to generate their respective thiadiazole‐linked COFs  spectra. After the conversion of the N‐acylhydrazone units, two new peaks appeared at 1641 and 653 cm−1, which could be ascribed to the stretching vibration of C═N and C─S in thiadiazole linkage, respectively. Correspondingly, the disappearance of C═O and C═N at 1670 and 1610 cm−1 in the N‐acylhydrazone motif, respectively, was observed, displaying that the N‐acylhydrazone units were converted into thiadiazole bonds  corresponds to thiadiazole N atom. In addition, the deconvoluted S 2p XPS spectra of TDA‐COF present one binding energy peak at 164.6 eV, corresponding to thiadiazole S atom . TDA‐COF still retains decent crystallinity after the modification of NAH‐COF Figure . The exp2 sorption isotherm at 77 K  specific surface areas of NAH‐COF and TDA‐COF are as high as 690 and 350 m2 g−1, respectively. The decrease of BET could be attributed to the increase of the framework mass and reduction of pore volume and crystallinity. Furthermore, TDA‐COF pore sizes are marginally smaller than that of NAH‐COF  and base (2 m NaOH) solutions, the strong reflections in the PXRD patterns of NAH‐COF became disappeared  measurements for NAH‐COF and TDA‐COF. As shown in FigureN‐acylhydrazone unit. The optical photo presents that TDA‐COF is golden yellow, while NAH‐COF is pale yellow. According to the Tauc plot, the optical band gap of TDA‐COF is 2.38 eV, which is significantly smaller than the 2.82 eV of NAH‐COF  as a sacrificial agent under visible‐light irradiation. The H2 evolution amount for TDA‐COF is 61.3 mmol g−1 in 5 h, while NAH‐COF presents an H2 production amount of 7.5 mmol g−1 under the identical conditions , the Arrhenius equation can be employed to fit the data, I(T) = I0/(1 + A exp(−Eb/kBT)). The Eb of TDA‐COF and NAH‐COF was estimated to be 42.5 and 74.2 meV, respectively. The lower Eb value suggests that non‐radiative pathways would occur more readily and less energy would be dissipated in the electron transfer process in TDA‐COF. Additionally, the generation of photoinduced charge carriers was characterized by electron paramagnetic resonance (EPR) spectroscopy. Specifically, the EPR signal intensity of TDA‐COF at g = 2.0083, corresponding to delocalized unpaired electron within the π‐conjugated COFs backbones, was stronger than that of NAH‐COF in the dark and under illumination  spectra were first examined Figure . When ex43 To n Figure . Meanwhi3N‐acylhydrazone to convert the reversible N‐acylhydrazone linkage into a fully conjugated and irreversible thiadiazole bond. In addition to retain the high crystallinity and ordered pore structure, the thiadiazole‐linked COFs demonstrate improved chemical stability, especially under strong acidic conditions. Importantly, the extended π‐electron delocalization by the formation of fully conjugated thiadiazole linkage facilitates visible‐light absorption, lower exciton binding energy, and suppresses recombination of the photogenerated electron‐hole pairs, leading to remarkably enhanced photocatalytic hydrogen evolution performance in comparison to its N‐acylhydrazone‐linked counterpart. This highly efficient approach allows for facile preparation of thadiazole‐linked COFs from widely available N‐acylhydrazole‐linked COFs, laying the foundation for investigating practical applications of thiadiazole‐linked COFs material.In conclusion, we have developed a facile COF post‐synthetic modification strategy based on the thionation, cyclization, and oxidation reaction of 4Experimental details are shown in the Supporting Information.The authors declare no conflict of interest.Supporting InformationClick here for additional data file.


Chronic pain is one of the most devastating and unpleasant conditions, associated with many pathological conditions. Tissue or nerve injuries induce comprehensive neurobiological plasticity in nociceptive neurons, which leads to chronic pain. Recent studies suggest that cyclin-dependent kinase 5 (CDK5) in primary afferents is a key neuronal kinase that modulates nociception through phosphorylation-dependent manner under pathological conditions. However, the impact of the CDK5 on nociceptor activity especially in human sensory neurons are not known. To determine the CDK5-mediated regulation of human dorsal root ganglia (hDRG) neuronal properties, we have performed the whole-cell patch clamp recordings in neurons dissociated from hDRG. CDK5 activation induced by overexpression of p35 depolarized the resting membrane potential and reduced the rheobase currents as compared to the uninfected neurons. CDK5 activation evidently changed the shape of the action potential (AP) by increasing AP rise time, AP fall time, and AP half width. The application of a prostaglandin E2 (PG) and bradykinin (BK) cocktail in uninfected hDRG neurons induced the depolarization of RMP and the reduction of rheobase currents along with increased AP rise time. However, PG and BK applications failed to induce any further significant changes in addition to the aforementioned changes of the membrane properties and AP parameters in the p35-overexpressing group. We conclude that CDK5 activation through the overexpression of p35 in dissociated hDRG neurons broadens AP in hDRG neurons and that CDK5 may play important roles in the modulation of AP properties in human primary afferents under pathological conditions, contributing to chronic pain. With ongoing pathological pain signaling, neuroplastic changes can occur that give rise to hyperalgesia and allodynia19. Peripheral sensitization, for instance, can arise with transcriptional and post-translational modifications downstream of inflammation. This generally includes the activation of protein kinases such as PKA, PKC, and Cyclin-dependent kinase 5 (Cdk5) in primary afferent neurons26. These protein kinases can, in turn, phosphorylate ion channels involved in pain signaling and then can lower their threshold of activation, affect channel desensitization, or enhance channel trafficking to the plasma membrane. Of these protein kinases, Cdk5 is unusual in that it shares a high degree of homology with other Cdk’s that predominately regulates the cell cycle instead of being active in post-mitotic neurons34. In addition, Cdk5 activity is neither induced by a cyclin, as typical with other Cdk family members, nor with a second message molecule as seen with PKA, PKC, and the Ca2+/calmodulin-dependent protein kinase CaMKII. Instead, Cdk5 activity is regulated through the expression of its regulatory subunit p35, which binds with Cdk5 through a cyclin box. The upregulation of p35 occurs in the dorsal root ganglia following peripheral inflammation of the rodent hindpaw via carrageenan26 or complete Freuend’s adjuvant42 or neuropathic injury by spinal nerve ligation12. Further studies have shown that inflammatory cytokines including tumor necrosis factor α, transforming growth factor β, and nerve growth factor can trigger ERK1/2 activation to subsequently boost p35 expression and ultimately lead to increased Cdk5 activity38.Chronic pain affects about 20% of adults in the United States and for its effective treatment, the development of novel efficacious therapies without addiction liability are urgently required27. This has been partially attributed to Cdk5 mediated phosphorylation of pain transducing ion channels such as the thermosensor transient receptor potential vanilloid subtype 1 (TRPV1)25, the chemosensor transient receptor potential ankyrin subtype 112,32, and the purinergic receptor P2X24. Phosphorylation by Cdk5 can then essentially potentiate pain signaling by curbing channel desensitization in TPRV1, for example15. The dysregulated trafficking of voltage-gated ion channels has also associated with chronic pain, where Cdk5 is known to phosphorylate both Cav3.2, to cause enhanced trafficking to the plasma membrane, and CRMP2, which affects the trafficking of Nav1.7 and Cav2.211,22.Cdk5 hyperactivity in primary afferent neurons has consequently been implicated with increased pain hypersensitivity. The transgenic overexpression of p35 alone can, in effect, promote both thermal and mechanical pain in mice40. The electrical properties of neurons including action potential, spike width, and spike threshold are tightly regulated by the ionic gradients, ion channels activation/deactivation time and their state of phosphorylation/dephosphorylation35. Despite the association of upregulated Cdk5 activity with hyperalgesic conditions, the role of Cdk5 in the modulation of human sensory neuronal properties has not been fully elucidated. Recently, electrophysiological recording of dissociated hDRG neurons has been possible through organ-donor networks13. Single nucleus sequencing shows that CDK5 and its activator p35 (CDK5R1) are widely expressed in hDRG neurons23. So, an overall assessment of the effects of Cdk5 hyperactivity and other pain associated protein kinases on hDRG neurons has currently become feasible. In this study, to extend our previous preclinical studies on the roles of Cdk5/p35 in pain, we determined the effects of Cdk5 activation on hDRG neuronal firing. We aimed to determine the effects of exogenous overexpression of p35 on the changes in the excitability, action potential properties, and responses to inflammatory mediators in dissociated human DRG neurons.Pathological pain conditions are accompanied by altered the electrophysiological properties 2.2.1.DRGs used in this study were acquired from seven cadaveric donors with the informed consent of the next of kin through Anabios . AnaBios Corporation’s procurement network includes only US-based Organ Procurement Organizations and Hospitals. Policies for donor screening and consent are the ones established by the United Network for Organ Sharing (UNOS). Organizations supplying human tissues to AnaBios follow the standards and procedures established by the US Centers for Disease Control (CDC) and are inspected biannually by the DHHS. Distribution of donor medical information complies with HIPAA regulations regarding patient privacy. All transfers of donor organs to ANABIOS are fully traceable and periodically reviewed by US Federal authorities. We obtained approval for carrying out these studies from the National Institutes of Health (NIH) Office of Human Subjects Research Protection (OHSRP) and Biosafety Committee, Bethesda, MD, USA. All methods were performed in accordance with the guidelines and regulations approved by NIH Biosafety Committee, Bethesda, MD, USA.Donor DRGs  from males and females were harvested using AnaBios’ proprietary surgical techniques and tools shipped to AnaBios via dedicated couriers. Upon arriving at AnaBios, each set of DRGs was assigned a unique identifier number that is reproduced on all relevant medical history files, data entry forms and electronic records. DRG were obtained from 5 donors.2.2.5.The DRGs were then further dissected in cold proprietary neuroplegic solution to remove all connective tissue and fat. The ganglia were dissociated following the methods previously describedAfter removing all connective tissue and fat, DRG were enzymatically digested at 37°C for 2 hours using AnaBios’ proprietary mixture of enzymes. After washing, the neurons were resuspended in DMEM/F12  containing 1% horse serum . Ganglia were gently triturated through the fire-polished tip of a sterile glass Pasteur pipette. Dissociated cells were plated on glass coverslips coated by poly-D-lysine.The isolated neurons put in culture in DMEM F-12 (Gemini Bio-Products CAT#: 900–955. Lot# M96R00J) supplemented with Glutamine 2 mM, Horse Serum 10% (Invitrogen #16050–130), hNGF (25 ng/ml) , GDNF (25 ng/ml)  and Penicillin/Streptomycin (Thermo Fischer Scientific #15140–122).2.3.33. After the confirmation of the p35 expression in Neuro 2a cells, pCMV-p35 was cloned into pDONR221 Gateway entry vector  and packaged into a herpes simplex virus 1 (HSV-1) vector . Replication-deficient virus was packaged via the amplicon system and purified on a sucrose gradient. In the HSV vector, an IE4/5 promoter drives p35 expression while the mCMV promoter drives the green fluorescent protein (GFP).To confirm expression of the Cdk5 activator p35 before packaging into HSV, an expression vector with an untagged human p35, pCMV-p35 , was transfected into Neuro 2a cells using Neuro-2a Cell Avalanchetransfection reagent . The expression of p35 was confirmed through Western blot, performed as previously describedThe cultures were infected by either HSV-p35 or HSV-GFP at a multiplicity of infection (MOI) of 3. Uninfected neurons were also assessed to estimate the effects of viral infection. The neurons were used for recordings 1–4 days after infection.2.4.2, 1 mM MgCl2, 10 mM HEPES, 10 mM dextrose . Extracellular solution exchange was performed with rapid exchange perfusion system (flow rate 0.5–1 ml/min) (Warner Instruments #64–0186). Neurons for recordings were selected based on smoothness of the membrane. Neurons were held at a resting membrane potential (RMP). Signals were filtered at 3 kHz, sampled at 10 kHz. Once whole-cell access was obtained the cell was allowed an equilibration time of at least 5 min. Neurons showing series resistance >15 MΩ were excluded from further recordings. Unless otherwise indicated, all chemicals were purchased from Sigma-Aldrich.Whole-cell patch-clamp recordings were conducted in hDRG neurons 3 to 6 days after dissociation . The rec2.5.Once the cell under recording stabilized, the rheobase of single action potentials was assessed. Step currents in 20 ms duration were delivered every 10 sec. The amplitude of currents was incrementally increased until action potential can be faithfully induced. The step increment was 20 pA if the current amplitude was <1000 pA and 50 pA if the current amplitude was >1000 pA. The minimum current needed for stable action potential induction was documented as rheobase. After measuring rheobase in baseline, 1μM prostaglandin E2 and 100nM bradykinin were applied through bath superfusion . The rhe2.6.30. SH-SY5Y cells were transfected with either an empty vector or with a vector expressing His-tagged human p35 (gift from Dr. Harish Pant) using Lipofectamine 3000 . Two days after the transfection, cells were treated with various inflammatory mediators. CDK5 activity was measured as previously described34.To test different inflammatory cocktails for induction of Cdk5 activity, SH-SY5Y cells were differentiated as described in the literature2.7.In addition to the RMP and rheobase, the kinetics of single action potentials evoked by the rheobase currents were measured . Data we3.CDK5 and CDK5R1, encoding p35, are expressed in almost every cluster, including peptidergic and non-peptidergic nociceptors23  showed robust inductions of CDK5 activity, both with and without additional transfection of p35. Therefore, the mixture of these two mediators (PG/BK) was used in the following experiments.Since inflammation of the hindpaw causes increased Cdk5 activity in DRG in rats, we would test if inflammatory mediators increase CDK5 activity in human neuronal cells. We used differentiated SH-SY5Y cells for evaluating CDK5 activity following transfection with either an empty plasmid or with a His-tagged human p35 expression vector. As shown in To determine the changes of the excitability of sensory neurons induced by the activation of CDK5, we infected dissociated hDRG neurons using HSV encoding p35. Neurons infected by HSV encoding GFP served as a control group. To control the effects of HSV transfection, we also tested the uninfected (UI) group. Data were obtained from 10 UI neurons, 9 GFP-expressing neurons, and 9 p35-expressing neurons. By using whole-cell current clamp recordings , we firsWe determined the changes in the AP shape using the parameters described in Three groups did not show differences in AP amplitude  on the electrophysiological properties of hDRG neurons in p35-transfected, GFP-transfected, and uninfected groups.After assessing RMP, rheobase currents, and AP properties under baseline condition, PG/BK was applied to the bath for five minutes and AP was evaluated again. PG/BK significantly depolarized the RMP in UI (p= 0.03 in Wilcoxon signed rank test PG/BK application significantly increases the AP rise time in UI (p= 0.014), but not in GFP (p= 0.3) and p35 group (p= 0.16)  and that HSV infection itself apparently affects the properties of hDRG neurons. Nonetheless, the impact of p35 overexpression on the broadening of AP was evident, which strongly supports the idea that CDK5 hyperactivity influences the electrophysiological properties of hDRG neurons.The contribution of CDK5 in primary afferents has been well established through preclinical models. However, there is no evidence supporting the roles of CDK5 in nociceptor functions in humans. In this study, we have used an electrophysiological approach to investigate the role of CDK5 on the membrane properties and action potential properties of hDRG neuronal culture. To the best of our knowledge, this is the first report demonstrating that the activation of CDK5 influences the AP properties in human sensory neurons. In this study, we designed to test two pathologically relevant conditions to determine the impact of CDK5 activation on the properties of hDRG neurons. First, we mimicked the upregulation of CDK5 activity by the increased expression of p35. In preclinical models, overexpression of p35 alone increases pain sensitivity in mice without producing inflammation or nerve injury43. However, PG/BK application did not produce any significant changes either in membrane properties or AP properties in GFP- and p35-expressing groups. Given the tendency of depolarized membrane potential and decreased rheobase following p35 transfection, we postulate that additional activation of CDK5 by PG/BK following p35 overexpression may be modest and does not produce any further changes. Again, however, the interpretation of the data is limited by the large variation of the data, the impact of HSV infection, and the insufficient sample size.Acute application of PG/BK in bath altered the membrane properties (rheobase and RMP) and AP properties (AP rise time) in uninfected hDRG neurons. This is consistent with the fact that inflammation enhances Cdk5 activity in DRG of rodents+ channels and Ca2+ currents contribute to different phases of AP in DRG neurons2. Action potential of nociceptive neurons shows wide action potential with a characteristic hump on the falling phase39. Such characteristic is attributable to TTX-resistant Na+ channels and voltage-gated Ca2+ channels. Large conductance Ca2+-activated K+ channels also contribute to the duration of AP in non-peptidergic nociceptive DRG neurons45. It is not clear what is the functional implication of the wide AP in nociceptors. We speculate that nociceptors may be optimal for the transduction and conduction of low-frequency stimuli. AP broadening should increase Ca2+ influx in presynaptic terminals, which can induce more efficient nociceptive synaptic transmissions. The peripheral and central nociceptive system may be optimized for the low-frequency encoding in the transduction and conduction of nociceptive signal to differentiate it from the high-frequency non-nociceptive conduction systems, such as tactile sensation or proprioception.AP time course represents the ensemble of depolarizing and repolarizing ionic conductances. Intricate balances of voltage-gated sodium, calcium, and potassium channels produce neuronal AP firing. Different inward currents from TTX-sensitive and TTX-resistant Na+ currents33. Chronic constriction injury of the infraorbital nerve or chemotherapy-induced neuropathy by oxaliplatin leads to an increase in AP widths of trigeminal ganglia neurons, which is likely through the downregulation of Kv4.342. Peripheral axotomy broadens AP mediated by the downregulation of Kv2.1 and Kv2.236. Mutation of Nav1.7 associated with erythromelalgia increases AP width18. Our study shows that the activation of CDK5 through p35 overexpression broadens AP in human DRG neurons. Since Cdk5 is upregulated in the DRG after spinal nerve ligation in rats11, AP broadening can be associated with the pathological condition likely contributing to neuropathic pain in humans. Therefore our data strongly suggest that CDK5 can play a modulatory role in human primary afferents contributing to chronic pain.Importantly, AP width is not static, but the broadening of AP in sensory neurons occurs in multiple pathological conditions through various mechanisms. For example, monocyte chemoattractant protein-1 broadens action potential in DRG neurons through the increase of non-selective cationic currents and the inhibition of voltage-dependent K2+ transients, potassium, and sodium channel activities17. The inhibition of Cdk5 activity reduces the TRPV1-mediated Ca2+ influx in rat DRG neurons25. Nav1.7 channel activity is regulated by CDK5-dependent phosphorylation of CRMP2 (a binding partner of NaV1.7) in neuropathic pain condition8. Cdk5 also phosphorylates and regulates both high voltage-activated N-type Cav2.231 and low voltage-activated T-type Cav3.210 Ca2+ channels. CDK5 regulates the voltage-gated Kv2.1 channels through direct phosphorylation, which is crucial to activity-dependent plasticity in intrinsic neuronal excitability3. CDK5 also regulates the activity of Kv7.2 channels through its phosphorylation29. Our substrate analysis suggested that CDK5 may phosphorylate other voltage-gated ion channels, such as Nav1.9, Cav3.3, Kv6.2, and KCa2.114. Therefore, CDK5 activation may broaden AP in hDRG through the ensemble regulation of the voltage-gated ion channels, which suggests that CDK5 is an important upstream regulator of AP properties in pathological conditions.Since we did not evaluate CDK5-induced changes in ionic currents by voltage clamp, we do not have evidence underlying the mechanisms of AP broadening. AP width is predominately determined by CaIn conclusion, CDK5 activation through the exogenous overexpression of p35 in dissociated hDRG neurons broadens AP. Our data suggest that CDK5 plays an important role in the modulation of AP properties in human primary afferents under pathological conditions and contributes to chronic pain.


Background and purposeThe patients after amputation undergo a sudden transformation in their quality of life. In India, amputation done at the appropriate time is a rare phenomenon because usually, the patients present themselves at the later stages. The surgeons, however, while performing amputation surgeries, primarily consider saving the life of a patient under adverse conditions when patients report to them very late that the surgeries are carried out urgently. Assessing the quality of life (QOL) and the various sociodemographic factors affecting the QOL paves the way for future rehabilitation programs.Aims and objectivesTo evaluate the quality of life of subjects with unilateral lower limb amputation among the North Indian population.Materials and methodsThis cross-sectional study was conducted in the tertiary rehabilitation center. A total of 106 Subjects were recruited. Informed consent was taken. WHOQOL-BREF contains 26 items covering four important aspects of QOL. The WHOQOL-BREF self-administered free questionnaire was used as a data collection tool, and the Hindi version downloaded from the WHO website was also used for those who can't understand English.ResultsThe range of the physical domain, psychological domain, social domain, and environmental domain were 0 and 100. The mean score of different QOL transformed domain scores  were 47.91±20.12, 57.37±20.46, 59.36±25.32 and 51.50±21.96, respectively. Trauma was the leading cause of amputation, followed by diabetes mellitus, cancer, peripheral vascular disease, and other causes. Transtibial amputees were more in number compared to transfemoral. The percentage of male and female amputees was 78.30%, and 21.70%, respectively.ConclusionThe physical domain was the most affected domain, followed by the psychological, social, and environmental domains. A delay in the prosthesis fitment aggravates the physical burden of amputees. Early prosthesis & psychological counseling will improve the QOL significantly. Amputation is the surgical removal of a limb or body part. It is performed to remove diseased tissue or to relieve pain or/due to trauma. It is done when the salvage of the limb is not possible. Lower limb amputation is one of the oldest surgical procedures in the history of surgery . Trauma World Health Organization (WHO) defines the quality of life as an individual’s perception of their position in life in the context of the culture and value systems in which they live and in relation to their goals, expectations, standards, and concern ,3. WHO fThe main function of the lower limb is the locomotion function. Once the locomotion function is affected, it will interfere with the employment of the patient. It also affects the economic, social, and psychological impact of the patient as well as his family members . TherefoIn North India, there is no such study to the best of our knowledge to describe the information about the quality of life in unilateral lower limb amputees. The main aim was to assess the various sociodemographic factors affecting the QOL of the lower limb amputees. The future holistic approach to rehabilitation programs for people with lower limb amputation can be improved by this study.This is a cross-sectional study. Subjects with unilateral lower limb amputees were recruited from indoor and Outdoor facilities of the Department of Physical Medicine & Rehabilitation or referred from any other department. Informed consent was taken. The WHOQOL-BREF self-administered questionnaire was used as a data collection tool. We conducted this study on the North Indian population. For those who can’t understand the English version of WHOQOL-BREF, we used the Hindi version of the WHOQOL-BREF questionnaire.The study was approved by IRB/Committee: King George's Medical University Institutional Ethics Committee .Sample size and statistical analysisA sample size of 106 was obtained with 95% confidence level and 90% power of a similar study . SignifiInclusion criteria1) Age: 18 years and above, 2) patients with unilateral lower limb amputation, 3) post-amputation with duration over three months, 4) subjects willing to participate and to give informed consent.Exclusion criteria1) Patients with upper limb and/or bilateral lower limb amputation, 2) post-amputation with a duration less than three months, 3) subjects who refused to participate, 4) patients with hearing, speech, and visual function disorders and other associated polytrauma like TBI, SCI, etc., 5) patients with psychiatric illness.The percentage of <20 years, 20-39 years, 40-59 years, and >60 years age groups were 4.72%, 48.11%, 32.08%, 15.09%, and 100%, respectively. The majority of the patients belonged to the 20 - 39 years old age group, as shown in Table The percentage of males and females was 78.30%, and 21.70%, respectively. The most common cause of amputation was road traffic accidents, as shown in Table The percentage of transtibial amputation, transfemoral amputation, and others were 63.21%, 34.91%, and 1.89%, respectively. The percentage of illiterate, primary school, middle school, high school, and beyond high school was 23.58%, 9.43%, 16.98%, 20.75%, and 29.25%, respectively. The percentage of working, pension/service, unemployment, and dependent was 26.42%, 6.60%, 4.72%, and 62.26%, respectively. Most amputees lost their job after amputation. The duration of prosthesis use is shown in Table The range of the physical domain, psychological domain, social domain, and environmental domain were 0 and 100. The mean score of different QOL transformed domain scores  were 47.91±20.12, 57.37±20.46, 59.36±25.32 and 51.50±21.96, respectively. The physical domain has the least score among all, as shown in Table The mean physical domain and environment domain scores were significantly different between different educational statuses. Moreover, the mean psychological domain and social domain were not significantly different between different Educational statuses, as shown in Table The mean physical domain, psychological domain, and environmental domain scores were significantly different between different age groups, as shown in Table The mean physical domain, psychological domain, and environmental domain scores were significantly different between different financial statuses. Moreover, the mean social domain was not significantly different between different financial statuses, as shown in Table Factors affecting QOLAgeThe mean physical domain, psychological domain, and environmental domain scores were significantly different in different age groups. G.D. Pooja et al., in 2012, did a study in Kolkata and also found that the majority of amputees who were of working age lost their jobs due to their decreased physical capacity .Male vs. FemaleSeveral studies showed a higher prevalence of lower limb amputation in males compared to females. Sinha et al. did a study in Mumbai and also found that most of the amputees were male, comprising 88% . A studyEducation and QOLThe mean physical domain and environment domain scores were significantly different between different educational statuses. People with a good education have better adaptability to post-amputation body changes and have good exposure to existing healthcare services.Work and QOLIn the current study, the mean physical domain and environmental domain scores were significantly different between different educational statuses. Many amputees, who were only the earning members of their families, lost their job and became totally dependent. Grewal VS et al. did a study in 2019 that also stated that employment status is an important determinant of QOL [Income and QOLIn the current study, the mean physical domain, psychological domain, and environmental domain scores were significantly different between different financial statuses. Grewal VS et al. did a study in 2019 that also states that the overall QOL score was highest for the study participants belonging to the upper socio-economic class [Socio-demographic factorsCauses of AmputationThe percentage of RTA, DM, cancer, PVD, and other causes of amputation were 68.87%, 8.49%, 8.49%, 7.55%, and 6.60%, respectively. O’Keeffe and Rout did a study in 2019 and also reported that the most common cause of amputation was trauma [According to A. Esquenazi causes of amputations may vary from country to country, but in developing counties, trauma alone accounts for more than 80%. In developed nations like the US and Japan, the vascular disease leads to the major cause of amputation .Level of AmputationThe percentage of transtibial amputation, transfemoral amputation, and others were 63.21%, 34.91%, and 1.89%, respectively. Unnikrishnan et al. did a study in 2017 and also found transtibial amputation was more than 53.1%, while transfemoral amputation was 37.1% . RaichleProsthesis vs. Nonprosthesis UserThe percentage of people using and without prostheses was 39.62% and 60.38%, respectively. Prosthesis provides support for mobility in the workplace. Amputees who didn't receive their prostheses can't resume their work -17. Due Stump-Related ProblemsThe percentage of people with and without stump-related problems was 20.75% and 79.25%, respectively. Stump-related problems like phantom limb pain, residual limb pain, reduced range of motion, ulcers, discharging sinus, and bony prominence, etc., were the main reasons for the delay in being fitted with a prosthesis . Lack ofLimitations of the studyDirect analysis of the amputee's functional competence was not done. Selection bias could have influenced our results because only subjects visiting our hospital were enrolled.The physical domain was the most affected of all, followed by the psychological domain. Stump-related problems, financial burdens, and delayed rehabilitation lead to delayed prosthesis fitment. This ultimately paved the way for their decreased physical capacity. These points should be kept in mind for future rehabilitation purposes.