Objective To address the challenges of poor performance and lack of interpretability in existing models,the SHAP algorithm is used to develop an interpretable machine learning model that offers a novel approach to wound age estimation,Methods Based on the previous discovery of the expression of 35 wound age healing-related genes in contused skeletal muscle,the woun age estimaton model was constructed using four algorithms,namly,Multilayer Perceptron(MLP),Random Forest(RF),LightGBM(LGBM),and Support Vector Machine(SVM).The SHAP(Shapley Additive Explanation)algorithm was used to rank the importance of genetic features,eliminate redundant attributes,and optimize the model for accurate wound age estimation.the genetic features of the optimal model were analyzed using SHAP's local interpretation capabilities.Results The best results were obtained using model of MLP(area under the curve(AUC)=0.99)The wound ages were classified into four categories:4～12 h,16～24 h,28～36 h,and 40～48 h,using only 15 gene features.According to SHAP analysis,Fam210a was identified as the most relevant gene.Local analysis revealed that high expression of Fam210a contributed to an increase in the predicted probability of 4 h～12 h,while high expression of Rae1 contributed to an increase in the predicted probability of 16 h～24 h.Additionally,low expression of Tbx18 contributed to an increase in the predicted probability of 28 h～36 h,whereas high expression of Tbx18 contributed to an increase in the predicted probability of 40 h～48 h.Conclusions The combined MLP and SHAP model can be used to predict wound age.Using the SHAP interpreter can better understand the degree of contribution of feature genes to the model prediction,and lay the foundation for further in-depth study of wound age estimation.

Mitochondrial myopathy is a group of multi-system diseases in which mitochondrial DNA(mtDNA)or nuclear DNA(nDNA)defects lead to structural and functional dysfunction of mitochondria.The clinical manifestations of mitochondrial myopathy are complex and varied,and the testing for mtDNA and nDNA is not widely available,so misdiagnosis or missed diagnosis is common.Chronic progressive external ophthalmoplegia(CPEO)is a common type of mitochondrial myopathy,which is characterized by blepharoptosis.Here we report a 38-year-old female with mitochondrial myopathy presented with chronic numbness and weakness of the limbs,accompanied by blepharoptosis that was recently noticed.Laboratory and head magnetic resonance imaging(MRI)examinations showed no obvious abnormalities.Muscle and nerve biopsies showed characteristic ragged red fibers(RRFs)and large aggregates of denatured mitochondria.Testing for mtDNA and nDNA showed a known mutation c.2857C＞T(p.R953C)and a novel variant c.2391G＞C(p.M797I)in the polymerase gamma(POLG)gene,so the patient was diagnosed as mitochondrial myopathy.Clinicians should pay more attention to long-term unexplained skeletal muscle diseases with recent onset blepharoptosis.Histopathologic examination and genetic testing are of great value in the early diagnosis and therapeutic intervention.

Objective To analyze the epidemiological characteristics and drug resistance of pathogenic bacteria in 276 hospitalized children with lower respiratory tract infection to facilitate prevention and treatment. Methods Among of 276 hospitalized children with lower respiratory tract infection from January 2019 to December 2021 were analyzed. Data on the distribution of pathogenic bacteria were collected and analyzed. At the same time, the information on drug resistance was collected, and the potential relationship between pathogen distribution and drug resistance was briefly analyzed and discussed. Results A total of 532 strains of pathogenic bacteria were detected in the blood samples from 276 patients in this study. There were 207 strains of Gram-positive bacteria, including 104 strains of Staphylococcus aureus, 96 strains of Staphylococcus epidermidis and 7 strains of others. Gram negative bacteria (325 strains) were 172 strains of Klebsiella and 153 strains of Escherichia coli. The distribution of pathogenic bacteria in different gender and age groups (under 5 years old, 5-10 years old, and over 10 -14 years old) was calculated separately. The results showed that the distribution of pathogenic bacteria in female children under 5 years old (n=49 cases) was different from the total population: the infection of Gram-positive bacteria was higher than that of Gram-negative bacteria, and the proportion of Staphylococcus epidermidis was the highest (P<0.05). The distribution characteristics of children of other ages and sexes were consistent with the total distribution characteristics. The resistance rate of Gram-positive bacteria to penicillin, erythromycin and clarithromycin was high, while the resistance rate of Gram-negative bacteria to ampicillin, cefazolin and cefuroxime was high. The distribution characteristics were the same in children of different sex and age. Conclusion The pathogenic bacteria in children with lower respiratory tract infection in pediatric ward are mainly Gram-negative bacteria, and the main pathogenic bacteria have a high resistance rate to common drugs. The distribution of pathogenic bacteria in female children under 5 years old is unique: the infection of Gram-positive bacteria is higher than that of Gram-negative bacteria, and the proportion of Staphylococcus epidermidis is the highest, which deserves attention. The clinical drug sensitivity test can be used as an important reference for the treatment of drugs to guide the rational selection of antibiotics.

Purpose: From the perspective of positive psychology, our study aimed to explore depressive symptomsand psychological well-being among Chinese nurses, as well as analyze the impacts of characterstrengths, self-efficacy and social support on the mental health of nurses. Methods: A cross-sectional and descriptive design using five self-reported questionnaires was used toinvestigate a cohort of 4238 nurses during 2018. A structural equation modeling analysis was used toverify a hypothetical model linking character strengths, self-efficacy, social support, depressive symptoms,and psychological well-being. Results: The prevalence of depression among this cohort of Chinese nurses was 58.1%. The mean scoresfor caring, inquisitiveness, and self-control were 19.93 (SD = 2.82), 15.94 (SD = 3.00), and 16.34(SD = 2.95), respectively. The hypothesized model was a good fit of the data (x2/df = 1.77, p = .183, rootmean square error of approximation = 0.04, goodness of fit index = 1.00, comparative fit index = 1.00,TuckereLewis index = 1.00). Except for the path from self-control to depression, the other hypotheticalpaths investigated were statistically significant. Conclusion Character strengths were directly and positively associated with psychological well-being.Inquisitiveness was the strongest direct protective factor for depression. In addition, characterstrengths indirectly alleviated depression and increased psychological well-being through mediatingvariables of social support and self-efficacy. This study should alert nurse managers that more attentionshould be paid to the character strengths and mental health of nurses. This study provides evidence forinterventions based on character strengths as a management strategy to support the mental health ofnurses.

Purpose: From the perspective of positive psychology, our study aimed to explore depressive symptomsand psychological well-being among Chinese nurses, as well as analyze the impacts of characterstrengths, self-efficacy and social support on the mental health of nurses. Methods: A cross-sectional and descriptive design using five self-reported questionnaires was used toinvestigate a cohort of 4238 nurses during 2018. A structural equation modeling analysis was used toverify a hypothetical model linking character strengths, self-efficacy, social support, depressive symptoms,and psychological well-being. Results: The prevalence of depression among this cohort of Chinese nurses was 58.1%. The mean scoresfor caring, inquisitiveness, and self-control were 19.93 (SD = 2.82), 15.94 (SD = 3.00), and 16.34(SD = 2.95), respectively. The hypothesized model was a good fit of the data (x2/df = 1.77, p = .183, rootmean square error of approximation = 0.04, goodness of fit index = 1.00, comparative fit index = 1.00,TuckereLewis index = 1.00). Except for the path from self-control to depression, the other hypotheticalpaths investigated were statistically significant. Conclusion Character strengths were directly and positively associated with psychological well-being.Inquisitiveness was the strongest direct protective factor for depression. In addition, characterstrengths indirectly alleviated depression and increased psychological well-being through mediatingvariables of social support and self-efficacy. This study should alert nurse managers that more attentionshould be paid to the character strengths and mental health of nurses. This study provides evidence forinterventions based on character strengths as a management strategy to support the mental health ofnurses.

Objective Take frizzled class receptor 4(FZD4) as an example for exploring whether the transmembrane receptor protein is a suitable marker for wound age estimation. Methods A total of 78 Sprague-Dawley rats were divided randomly into the control group and the contusion groups of 4h, 8h, 12h, 16h, 20h, 24h, 28h, 32h, 36h, 40h, 44h, and 48h after injury (n=6). Using a drop-ball technique, a contusion was produced in the right lamb of rats. The samples were dissected from injury zones. Then the expression of FZD4 was detected using immunofluorescence, real-time PCR and western blot, respectively. Results FZD4 was located on the membrane of skeletal muscle cells. Compared to the control group, FZD4 mRNA showed a signiifcant increase (over 2-fold) in 8h, 12h, 36h, and 40h after injury by Real-time PCR (P<0.05), and FZD4 protein showed a statistical up-regulation (less than 2-fold) in 8h, 36h, 40h, 44h, and 48h post contusion by western blotting (P<0.05). Conclusion The expression of FZD4 mRNA and protein are both time-dependent during contused skeletal muscle repair. To some degree, FZD4 mRNA was more suitable than corresponding protein for determining wound age.

Objective To develop a biosensor method with strong specificity and high‐throughput by combining with the surface plasmon resonance (SPR) and gene chip technique and aiming at 9 kinds of common respiratory tract viruses including influenza A and influenza B ,(Influ A ,B) ,H1N1 ,respiratory syncytial virus (RSV) ,parainfluenza virus 1 -3 (PIV1 -3) ,adenovirus (ADV) and coronavirus (SARS) leading to severe acute respiratory syndrome .Methods Firstly the software primer 5 was used to design the specific primer and probe of related viruses in the conserved sequence ;the designed nine kinds of corresponding respiratory virus probes were immobilized in the specific region of SPR chip after chemical modification .The SPR technique was applied to conduct the real time monitoring the hybridization process of the probe with the PCR products .Finally the signal amplification was realized by the biotin and streptavidin system .Results The designed gene chip could detect 9 kinds of respiratory tract viruses by high‐throughput with better detection specificity ;the chip surface could be reutilized after certain regeneration condition ,which avoided the influence of intra‐batch difference on the results ;the detection sensitivity reached the nanomole level .Conclusion The prelimi‐nary study results demonstrate that using the SPR biosensor technique to establish a high‐‐throughput detection of respiratory tract viruses has some practicability and feasibility ,and is expected to become a rapid ,large scale and high‐ throughput measure for screening respiratory tract viruses with good application prospect .

Objective T o investigate the relation betw een injury tim e and the expression of cytochrom e c oxidase subunitⅥc (COX6C) m R N A in skeletal m uscle of rat after contusion. Methods A total of fifty-four SD rats w ere divided into the control group and the contusion groups (0.5,1,6,12,18, 24, 30, and 36 h after contusion), random ly. T he contusion m odel w as established by free fall drop of gravity ham-m er. A t corresponding tim e point after contusion, the regular histology w as exam ined and expression level of COX6C m R N A w as tested by real-tim e PC R after extraction of total R N A from the tissues. Results T he m ain pathological features of 6 h after injury included edem a and hem orrhage in m yocytes w ith no inflam m atory cells found. A fter 6 hours, the findings included m yocyte degeneration and necro-sis, inflam m atory cells infiltration, and fibrous connective tissue proliferation in the contused zone. T he expression level of COX6C m R N A w as higher than that of the control group w ithin 6 h after contusion. T he expression level w as low er than that of the control group from 6-36 h after contusion. Conclusion T he level of COX6C m R N A expresses in a regular w ay after contusion. It m ay be useful for estim ating w ound age in com bination w ith the results of pathological features.

BACKGROUND:Skin transplantation is regarded as the most effective therapy for large-area skin defects, which is limited by donor sources and immune rejection. Therefore, it is extremely accelerate the construction of the dermis in skin tissue engineering.
OBJECTIVE:To investigate the effects of bone marrow mesenchymal stem cels/calcium alginate gel, basic fibroblast growth factor and degradation membrane on the repair of ful-thickness skin defects.
METHODS:Bone marrow mesenchymal stem cels were isolated from 15 New Zealand rabbits, and then cultured, amplified, subcultured and purified. Three ful-thickness skin defects were made on the back of every rabbit, and randomly treated with bone marrow mesenchymal stem cels/calcium alginate gel, basic fibroblast growth factor and degradation membrane as experimental group, bone marrow mesenchymal stem cels/calcium alginate gel as control 1 group, and calcium alginate gel as control 2 group. The wounds were al covered with amniotic membrane. After 7, 14, 21 days, new wound tissues were taken for hematoxylin-eosin staining, immunohistochemistry staining and image analysis.
RESULTS AND CONCLUSION: Dermis tissues in the experimental group were obviously thicker than those in control 1 and control 2 groups; there were more fibroblasts, vessels and colagen fibers in the experimental group. Especialy at 14 and 21 days after operation, epidermal hyperplasia was faster with a larger coverage area in the experimental group, and at 21 days, the new epidermal tissues mainly exhibited multi-layered structure, which was superior to the control 1 and 2 groups. It folows that the combination of bone marrow mesenchymal stem cels/calcium alginate gel, basic fibroblast growth factor and degradation membrane for skin defects can accelerate the repair and regeneration of the dermis, and thus promote the epidermis regeneration and reconstruction.