Skin injuries always disturb people's normal life, even seriously damage the body health. Thus, it is very necessary to use medical dressings to protect and treat skin wounds. Compared with traditional dressings, novel biological dressings develop more rapidly and their application scope is gradually expanding. Collagen is a natural biological material that can promote wound healing and it also has unique functional advantages in care and treatment. At present, collagen-based medical dressings has become one of the preferred choices to assist wound healing. The authors summarize the source, functional advantages and product classification of collagen-based dressings, and introduce the characteristics and applications of various collagen-based dressings, to provides a reference for further research of the collagen-based wound dressings.

Objective To analyze the characteristic of Yunnan unexpected sudden death (YUSD) cases by pathological diagnosis of arrhythmogenic right ventricular cardiomyopathy (ARVC),in order to offer clue for ARVC etiologic research of YUSD.Methods The pathological diagnosis results of 9 cases of sudden death of ARVC in Yunnan,as well as epidemiological investigation data,were used to comprehensively analyze the pathological features of the pathological diagnosis of ARVC in Yunnan.Results The 9 cases including 8 females and 1 male,aged 16-47 years.The sudden death time was from June to August,mainly distributed in 8 families from the disease seriously ridden 7 villages.Three of them had a genetic history of family YUSD,2 cases had a history of mental stimulation,1 case had eaten Trogia venenata;and acute symptoms and signs were palpitation,chest tightness,shortness of breath,and loss of consciousness.Pathological observations were the typical ARVC change,mainly right ventricular lesions,with different degrees of cardiac enlargement and extensive adipose tissue infiltration in the ventricular wall.Among them,6 cases of fat infiltration almost reached the full thickness of the heart wall.In addition to the pathological changes of ARVC,8 cases were accompanied by one or several pathological changes in myocarditis,cardiac dysplasia,nephropathy,pulmonary edema,pneumonia and pancreatitis.Of the 9 cases,5 cases were diagnosed with ARVC,2 cases with ARVC and pulmonary edema,1 case with ARVC and acute hemorrhagic necrotizing pancreatitis,and 1 case with ARVC and Trogia venenata poisoning.The clinical examination abnormalities of the family members of the cases mainly showed arrhythmogenic electrocardiography changes and abnormal myocardial enzymes.Conclusions The nine cases have showed typical epidemiology characteristics of YUSD,and cardiachistological changes are consistent with the ARVC pathological diagnostic criteria.A part of YUSD cases may be caused by ARVC,and the inference will be proved by cadaveric pathologic examination and related pathogenic gene detection.

Objective To investigate the application effect of the sandwich teaching method in the course of Surgical Nursing . Methods Two classes of the students majoring in nursing were randomly divided into control group and observation group, with 36 students in each group. The students in the control group received the traditional teaching method, and those in the observation group received the sandwich teaching method . The teaching effect was compared between the two groups by theoretical assessment and questionnaire survey. SPSS 24.0 was used for analysis of variance and the t-test. Results Compared with the control group, the observation group had significantly higher scores of course assessment, learning atmosphere, and learning initiative. The observation group also had significantly higher good rates of learning atmosphere and learning initiative than the control group(P<0.05). Conclusion The sandwich teaching method can significantly improve students' abilities of communication and problem solving, arouse their enthusiasm of learning, and increase the interestingness of classroom, and therefore, it has a practical value in teaching.

Objective:To understand the electrocardiogram and echocardiography examination results of population in key areas of unexplained sudden death in Yunnan Province (referred to as Yunnan sudden death).Methods:From 2014 to 2022, electrocardiogram examination was performed on population (including same incident cases, relatives of the cases, villagers of the affected villages, and control individuals) in key areas of Yunnan sudden death from May to October each year. Echocardiography examination was performed on relatives of the cases and villagers of the affected villages, and the types of electrocardiogram and echocardiography changes were sorted out and analyzed.Results:Electrocardiogram examination was conducted on 1 same incident case, 241 relatives of the cases, 464 villagers of the affected villages, and 99 control individuals, respectively. The types of electrocardiogram changes in the same incident case were Q-T interval prolongation and sinus tachycardia. A total of 17 types of electrocardiogram changes were detected in the relatives of the cases, mainly including sinus arrhythmia (12.45%, 30/241), sinus bradycardia (11.20%, 27/241), and left axis deviation (8.30%, 20/241). A total of 21 types of electrocardiogram changes were detected in the villagers of the affected villages, mainly including left axis deviation (9.48%, 44/464), sinus bradycardia (8.19%, 38/464), and T-wave abnormalities (7.76%, 36/464). A total of 10 types of electrocardiogram changes were detected in the control individuals, mainly including sinus arrhythmia (12.12%, 12/99), T-wave abnormalities (9.09%, 9/99), and sinus bradycardia (7.07%, 7/99). Echocardiography examination was conducted on 49 relatives of the cases and 365 villagers of the affected villages, respectively. A total of 12 types of echocardiography changes were detected in the relatives of the cases, mainly including tricuspid regurgitation (18.37%, 9/49), decreased right ventricular diastolic function (8.16%, 4/49), aortic regurgitation (6.12%, 3/49), and atrial septal defect (6.12%, 3/49). A total of 15 types of echocardiography changes were detected in the villagers of the affected villages, mainly including tricuspid regurgitation (8.77%, 32/365), aortic regurgitation (6.85%, 25/365), and decreased left ventricular diastolic function (6.58%, 24/365).Conclusion:There are many types of changes in electrocardiogram and echocardiography in the population of key areas of Yunnan sudden death.

Objective:To analyze common pathogenic gene mutations of arrhythmogenic right ventricular cardiomyopathy (ARVC) in Yunnan unexplained sudden death (hereinafter referred to as Yunnan sudden death) cases, and explore the etiological relationship between Yunnan sudden death and ARVC.Methods:Four typical Yunnan sudden death affected counties (cities) were selected as investigation sites. Cryopreserved autopsy cardiac cavity blood samples were collected from Yunnan sudden death cases ( n = 3), and peripheral venous blood samples were harvested from their relatives (first, second, third and immediate degree of kinship, n = 67) and control population ( n = 49). The DNA of blood samples was extracted for amplification and sequencing of 97 exons of 5 common ARVC desmosomal protein [desmoplakin (DSP), desmocollin-2 (DSC2), desmoglein-2 (DSG2), plakophilin-2 (PKP2) and junction plakoglobin (JUP)] genes, and genetic lineage of Yunnan sudden death cases was investigated. Results:A total of 17 gene mutation sites were discovered in Yunnan sudden death cases and their relatives, with 6, 5, 4, 1 and 1 in the DSP, DSC2, DSG2, PKP2 and JUP genes, which were not found in the control population. Among them, 9 were newly discovered mutation sites and 8 were reported mutation sites. The DSP gene exon 24 c.8472 G>C, a pure contractual sense mutation, was common in the relatives of 4 cases in the same family surveyed; and one immediate relative carried a deletion mutation at c.2368 - 2370 of exon 15 of DSC2 gene.Conclusion:Yunnan sudden death cases and their relatives carry mutations in the ARVC desmosomal protein DSP, DSC2, DSG2, PKP2, and JUP genes, and the onset of some Yunnan sudden death may be associated with mutations in the ARVC desmosomal protein genes.

Objective To evaluate the characteristics of left ventricular structure ,function ,myocardial mechanics ,hemodynamics and synchrony in different phenotypes of hypertrophic cardiomyopathy ( HCM ) using state‐of‐the‐art echocardiography . Methods A consecutive series of 85 adult HCM patients w ho were admitted to the Xi Jing HCM center from January 2016 to November 2017 were collected . According to the peak left ventricular outflow tract pressure gradient in exercise stress echocardiography ,the patients were divided into three groups :patients with non‐obstructive HCM ( n ＝28) ,those with labile‐obstructive HCM ( n ＝27) ,and those with obstructive HCM ( n ＝ 30 ) . In addition ,16 normal family members of HCM patients were included as control group . T wo‐dimensional speckle tracking imaging ,tissue Doppler imaging and exercise stress echocardiography were used to evaluate the left ventricular function in resting and exercise states . Results ① As compared with the control group ,left ventricular end‐diastolic diameter decreased and left ventricular ejection fraction increased in all three HCM groups ( all P ＜ 0 .05 ) . Left ventricular maximum wall thickness and left ventricular mass index were the highest in obstructive HCM , followed by labile‐obstructive and non‐obstructive HCM ,and the lowest in the control group ( all P ＜0 .05) . ②A t rest ,the left ventricular global longitudinal ,circumferential and radial strain ( GLS ,GCS and GRS) ,as well as the twist of obstructive HCM were significantly lower than the other three groups ( all P ＜0 .05) . As compared with the control group ,the GLS and twist decreased in the labile‐obstructive and non‐obstructive HCM ( all P ＜0 .05 ) ,but there were no significant changes of GCS and GRS ( all P ＞ 0 .05 ) . T he obstructive HCM had the lowest mitral annular plane systolic excursion ( M APSE ) and s′,and the longest systolic peaking time standard deviation( T s‐SD) and early diastolic peaking time standard deviation ( Te‐SD) ( all P ＜0 .05) . T he left ventricular diastolic function of obstructive HCM ( e′,the E/e′ratio and the left atrial volume index ) was the worst ,labile‐obstruction and non‐obstructive HCM were better ,and the control group was the best ( all P ＜ 0 .001 ) . ③ During exercise ,the GLS ,GCS ,GRS ,twist of the left ventricle and the M APSE were the lowest in the obstructive HCM ,which increased in the labile‐obstructive and non‐obstructive HCM ,and were best in the control group . T he T s‐SD and Te‐SD were the shortest in the control group ,were prolonged in non‐obstructive and labile‐obstruction HCM ,and were longest in obstructive HCM ( all P ＜ 0 .05 ) . Additionally ,the exercise time of the control group was the longest , followed by non‐obstructive and labile‐obstruction HCM ,and the shortest in the obstructive HCM ( all P ＜0 .05) . T he M ET s of obstructive HCM were significantly lower than the other three groups ( all P ＜0 .05) . Conclusions In obstructive HCM ,the left ventricular systolic strain and synchronization ,as well as the M APSE ,are significantly impaired in patients both at rest and during exercise . T he patients with labile‐obstructive and non‐obstructive HCM have reduced left ventricular GLS , twist ,and e′,but normal left ventricular GCS ,GRS ,synchrony ,and M APSE at rest ,which are all impaired during exercise .

Objective:To expound the pathogenesis relationship between Yunnan unexplained sudden death (YUSD) and desmosomal protein gene mutations of arrhythmogenic right ventricular cardiomyopathy (ARVC).Methods:Four YUSD cases families by ARVC pathological diagnosis were selected, to collect heart blood samples of YUSD cases by ARVC pathological diagnosis( n=3), venous blood samples of immediate relatives with genetic relationship (case relatives, n=4) and control population without genetic relationship ( n=7). DNA was extracted for PCR amplification and sequencing of a total of 97 exons of the ARVC desmosomal protein genes plakophilin 2 (PKP2), desmoplakin (DSP), desmoglein 2 (DSG2), desmocollin 2 (DSC2), and junction plakoglobin (JUP), and the mutations of the 5 genes were analyzed in combination with the genetic family. Results:DSP gene mutations were found in all YUSD cases by ARVC pathological diagnosis and case relatives, and PKP2, DSG2, DSC2 and JUP genes mutations were found in 1 person each. The same person carried 1-3 genes mutations. DSP gene existed 4 exon mutation sites, and 1 of which was a newly discovered heterozygous synonymous mutation c.4014 C>A (p.A1338A). PKP2 gene existed 2 exon missense mutation sites in 1 YUSD case by ARVC pathological diagnosis, and 1 of which was a newly discovered heterozygous mutation c.739 G>C (p.G247R). One heterozygous missense mutation site c.799 G>A (p.A267T) of JUP gene was newly discovered, and the predictive value of protein function was 0.963, the possibility of abnormal changes in protein function was high. DSG2 and DSC2 genes each had one mutation site. However, no mutation was found in control population.Conclusions:Both YUSD cases by ARVC pathological diagnosis and case relatives carry ARVC desmosomal protein genes DSP, PKP2, DSG2, DSC2 and JUP mutations. There may be a certain pathogenesis relationship between YUSD and ARVC desmosomal protein gene mutations.

Objective:To investigate the clinical characteristics of asymptomatic carriers with 2019 novel coronavirus (2019-nCoV), and to provide clinical guidance for the management of asymptomatic infection with 2019-nCoV.Methods:The clinical data of 663 patients with confirmed coronavirus disease 2019 (COVID-19) admitted to Renmin Hospital of Wuhan University from January 11 to February 6, 2020 were collected. Patients were divided into asymptomatic group (21 cases) and symptomatic group (642 cases) according to the diagnostic criteria. General conditions, clinical classification, death, chest computed tomograph (CT) and laboratory results of patients were retrospectively collected. Mann-Whitney U test, chi-square test and Fisher exact test were used for statistical analysis. Results:All 663 patients were positive for 2019-nCoV nucleic acid tests. The age of patients in the asymptomatic group were significantly younger than those in symptomatic group (35.0 (31.5, 58.0) years old vs 58.5 (45.0, 69.0) years old, U=4 234.500, P=0.002). The proportion of patients <30 years old in the two groups was significantly different (19.0%(4/21) vs 6.1%(39/642), Fisher exact test, P=0.047). There were 15 women (71.4%) in the asymptomatic group and 327 women (50.9%) in the symptomatic group, while the difference of gender distributions was not statistically significant ( χ2=3.420, P=0.064). In addition, among patients with asymptomatic infection, the proportions of mild/ordinary, severe and critical patients were 10 cases (47.6%), 10 cases (47.6%), and one case (4.8%), respectively, which were not significantly different from those in symptomatic group (244 cases (38.0%), 305 cases (47.5%) and 93 cases (14.5%), respectively, χ2=1.847, P=0.397). As of February 9, one(4.8%) mild/ordinary patient in the asymptomatic group died who had malignant tumor. Twenty-four (3.7%) patients in the symptomatic group died including two mild/ordinary and 22 critical patients. There was no significant difference in mortality between the two groups(Fisher exact test, P=0.560). CT examination was performed on 594 patients, and 591 cases (99.5%) showed unilateral or bilateral pneumonia, and three cases (0.5%) showed normal. Conclusions:Patients with asymptomatic infection with 2019-nCoV are younger than symptomatic patients, and there are more patients under 30 years old in the asymptomatic group. The absence of clinical symptoms is not significantly associated with clinical classifications and mortality in COVID-19 patients.

Objective To study the desmosomal protein plakophilin-2(PKP2)gene mutation of arrhythmogenic right ventricular cardiomyopathy (ARVC) in different populations of Yunnan unexplained sudden death (YUSD) areas,and explore the relationship between PKP2 gene mutation and YUSD.Methods Heart blood samples of YUSD cases (n =7) and venous blood samples of YUSD immediate family (n =30) and other family (n =11) members were collected.Basic situation and genetic relationship of YUSD immediate family and other family were investigated,and electrocardiography (ECG) was examined.DNA from blood samples was extracted and 15 exons of PKP2 gene were sequenced to analyze the mutation of PKP2 gene in different populations.Results A total of 10 people carried 11 PKP2 gene mutation sites with a mutation rate of 20.83％ (10/48).Two mutation sites were novel (p.G247R,p.T298N),and the new mutation sites were carried by two YUSD cases.Eight missense mutations were heterozygous mutations,two of the three synonymous mutations were heterozygous mutations,and one was homozygous synonymous mutation.The mutation sites were significantly concentrated in 4 exons,which were No.1 097 base of exon 4,No.819 and 893 bases of exon 3.2,No.739 base of exon 3.1,and No.156 base of exon 1.One YUSD case of ARVC pathological change carried exon 3.1 (p.G247R) and exon 4 (p.L366P) compound heterozygous mutations,the other YUSD case carried exon 3.2 (p.T298N) heterozygous mutation.The YUSD cases and immediate family with PKP2 gene mutations showed obvious family genetic relationships,and they were all first-degree and second-degree relatives.The abnormal ECGs of YUSD immediate family and other family mainly were conduction block,arrhythmia and premature beat.Conclusion There is a high PKP2 gene mutation rate in different populations of YUSD areas,and there may be a certain etiological connection between PKP2 gene mutations and YUSD.

Objective:To explore the relationship between arrhythmogenic right ventricular cardiomyopathy (ARVC) desmosomal protein gene mutations and Yunnan unexplained sudden death (hereinafter referred to as Yunnan sudden death) by detecting 5 common ARVC desmosomal protein gene mutations of Yunnan sudden death cases and their relatives in Heqing County, Yunnan Province.Methods:In January 2021, the autopsy heart cavity blood was collected from Yunnan sudden death cases in 8 villages in Heqing County, and peripheral venous blood samples of relatives of the cases were collected. Blood samples' DNA was extracted, after PCR amplification, 97 exons of 5 desmosomal protein genes [desmoplakin (DSP), desmoglein-2 (DSG2), plakophilin-2 (PKP2), junction plakoglobin (JUP) and desmocollin-2 (DSC2)] were sequenced by Sanger method to analyze gene mutations.Results:Three blood samples of Yunnan sudden death cases and 36 blood samples of relatives were collected. A total of 26 gene mutation sites were detected in 39 blood samples, with a total mutation rate of 26.80% (26/97). There were 13, 5, 3, 3 and 2 mutation sites in DSP, DSG2, PKP2, JUP and DSC2 genes, respectively. Among them, 19 were reported mutations and 7 were new mutations: DSP gene exon 3 c.372G>A, exon 15 c.2090A>G, exon 17 c.2371C>A, exon 24-I c.8458T>G; DSG2 gene exon 8 c.861C>T; PKP2 gene exon 3 c.892C>A, exon 8 c.1725G>T. Three Yunnan sudden death cases and 36 relatives were all carriers of compound gene mutation, and the same person carried 3 - 9 gene mutation sites at the same time.Conclusion:Mutations of ARVC desmosomal protein genes DSP, DSG2, PKP2, JUP and DSC2 exist in Yunnan sudden death cases and their relatives, which may be the genetic background factors of some Yunnan sudden death.