Objective:To investigate the level of serum-neutralizing antibodies against Coxsackievirus A6 (CVA6) in a healthy population in Tianjin City from 2014 to 2020.Methods:From March 2014 to March 2020, 5 492 healthy volunteers were recruited in Tianjin City. The demographic information, personal hygiene habits, living environment hygiene, contact history with hand, foot and mouth disease cases within 6 months before the survey, history of upper respiratory tract infection, and medical history of the subjects were investigated using a self-designed questionnaire. Venous blood was collected from the volunteers, and the level of serum anti-CVA6 IgG neutralizing antibodies was determined by the micro-neutralization assay. The level of CVA6-neutralizing antibodies was compared in different years, regions, and age groups, and the influencing factors in healthy individuals were analyzed by an ordered logistic regression model.Results:The age of 5 492 healthy volunteers ranged from 0 to 77, with M ( Q1, Q3) of age being 21 (7, 32) years old, and a male-to-female ratio of 1∶1.09. The high, medium and low levels of CVA6-neutralizing antibodies among the volunteers were 5.39% (296), 30.35% (1 667) and 64.26% (3 529). The proportion of volunteers with high levels of CVA6-neutralizing antibodies decreased from 54.63% (437/800) in 2014 to 30.01% (229/763) in 2020, and it also decreased with age (all P values <0.001). The results of the ordered logistic regression model analysis showed that compared with those aged >35 years, volunteers aged 0-5 years had higher levels of CVA6-neutralizing antibodies [ OR (95% CI): 1.39 (1.16-1.67)]. Compared with those who did not wash their hands after going out and had poor living environments, volunteers who washed their hands after going out, had good and general living environments and had lower levels of CVA6-neutralizing antibodies [ OR (95% CI): 0.80 (0.70-0.91), 0.52 (028-0.88) and 0.54 (0.31-0.96), respectively]. Conclusion:The level of CVA6-neutralizing antibodies in Tianjin City remains at a relatively high level from 2014 to 2020 and shows a decreasing trend over the years.

Objective:To investigate the level of serum-neutralizing antibodies against Coxsackievirus A6 (CVA6) in a healthy population in Tianjin City from 2014 to 2020.Methods:From March 2014 to March 2020, 5 492 healthy volunteers were recruited in Tianjin City. The demographic information, personal hygiene habits, living environment hygiene, contact history with hand, foot and mouth disease cases within 6 months before the survey, history of upper respiratory tract infection, and medical history of the subjects were investigated using a self-designed questionnaire. Venous blood was collected from the volunteers, and the level of serum anti-CVA6 IgG neutralizing antibodies was determined by the micro-neutralization assay. The level of CVA6-neutralizing antibodies was compared in different years, regions, and age groups, and the influencing factors in healthy individuals were analyzed by an ordered logistic regression model.Results:The age of 5 492 healthy volunteers ranged from 0 to 77, with M ( Q1, Q3) of age being 21 (7, 32) years old, and a male-to-female ratio of 1∶1.09. The high, medium and low levels of CVA6-neutralizing antibodies among the volunteers were 5.39% (296), 30.35% (1 667) and 64.26% (3 529). The proportion of volunteers with high levels of CVA6-neutralizing antibodies decreased from 54.63% (437/800) in 2014 to 30.01% (229/763) in 2020, and it also decreased with age (all P values <0.001). The results of the ordered logistic regression model analysis showed that compared with those aged >35 years, volunteers aged 0-5 years had higher levels of CVA6-neutralizing antibodies [ OR (95% CI): 1.39 (1.16-1.67)]. Compared with those who did not wash their hands after going out and had poor living environments, volunteers who washed their hands after going out, had good and general living environments and had lower levels of CVA6-neutralizing antibodies [ OR (95% CI): 0.80 (0.70-0.91), 0.52 (028-0.88) and 0.54 (0.31-0.96), respectively]. Conclusion:The level of CVA6-neutralizing antibodies in Tianjin City remains at a relatively high level from 2014 to 2020 and shows a decreasing trend over the years.

Objective:To analyze the reproductive outcomes of the subsequent embryo transfer (ET) cycles in women with repeated implantation failure (RIF) after the management of uterine cavity abnormalities.Methods:This was a retrospective case-control study. The clinical data of 89 patients with repeated implantation failure who underwent hysteroscopy at Reproductive Medicine Center of the Department of Obstetrics and Gynecology, Tianjin Medical University General Hospital from January 1, 2017 to March 31, 2021 were analyzed. The patients were assigned to a normal uterine cavity (UC) group ( n=38) and an abnormal UC group ( n=51) according to hysteroscopic examination and endometrial biopsy results. Women in the abnormal UC group received relevant treatments, and all patients received the embryo transfer again. The reproductive outcomes were compared between the two groups in the subsequent ET cycles. Results:The prevalence of uterine abnormalities was 57.30% (51/89) in women with RIF. Chronic endometritis accounted for the highest incidence 39.33% (35/89). Among 38 women in normal UC group, 16 women got clinical pregnancy in the subsequent ET cycles, and 24 women in 51 got clinical pregnancy in the abnormal UC group. There were no differences in the implantation rate, the clinical pregnancy rate, and the ectopic pregnancy rate between the two groups (all P>0.05). The early abortion rate was significantly higher in the normal UC group [37.50% (6/16)] than in the abnormal UC group [8.33% (2/24), P=0.042]. Conclusion:The uterine abnormalities mainly occurred in women with primary infertility. The clinical pregnancy rate of women after correction of uterine abnormalities was similar to those women with normal UC. Hysteroscopy was advised to performed routinely to evaluate the uterine environment in women with RIF.

Objective:To analyze the reproductive outcomes of the subsequent embryo transfer (ET) cycles in women with repeated implantation failure (RIF) after the management of uterine cavity abnormalities.Methods:This was a retrospective case-control study. The clinical data of 89 patients with repeated implantation failure who underwent hysteroscopy at Reproductive Medicine Center of the Department of Obstetrics and Gynecology, Tianjin Medical University General Hospital from January 1, 2017 to March 31, 2021 were analyzed. The patients were assigned to a normal uterine cavity (UC) group ( n=38) and an abnormal UC group ( n=51) according to hysteroscopic examination and endometrial biopsy results. Women in the abnormal UC group received relevant treatments, and all patients received the embryo transfer again. The reproductive outcomes were compared between the two groups in the subsequent ET cycles. Results:The prevalence of uterine abnormalities was 57.30% (51/89) in women with RIF. Chronic endometritis accounted for the highest incidence 39.33% (35/89). Among 38 women in normal UC group, 16 women got clinical pregnancy in the subsequent ET cycles, and 24 women in 51 got clinical pregnancy in the abnormal UC group. There were no differences in the implantation rate, the clinical pregnancy rate, and the ectopic pregnancy rate between the two groups (all P>0.05). The early abortion rate was significantly higher in the normal UC group [37.50% (6/16)] than in the abnormal UC group [8.33% (2/24), P=0.042]. Conclusion:The uterine abnormalities mainly occurred in women with primary infertility. The clinical pregnancy rate of women after correction of uterine abnormalities was similar to those women with normal UC. Hysteroscopy was advised to performed routinely to evaluate the uterine environment in women with RIF.

Objective:To study the characteristics and evolution of the whole genome sequence of an imported Chikungunya virus (CHIKV) case in Tianjin, China, and to provide a scientific basis for the surveillance and control of CHIKV.Methods:The serum specimen of CHIKV was collected at Tianjin Second People's Hospital, on November 4th, 2019, and the viral RNA was extracted. Eleven overlapping primers were used to amplify the complete genome of CHIKV by RT-PCR. The amplification products were then subjected to next generation sequencing (NGS) using Illumina Miniseq platform.Results:The complete genome sequence of the Tianjin CHIKV obtained had similarities ranging from 92.72% to 99.86% with other Chinese isolates. Phylogenetic analysis indicated that the Tianjin CHIKV belonged to the Indian Ocean Lineage (IOL), East/Central/South African (ECSA) cluster, consistent with most strains from China. The Tianjin CHIKV is most similar (99.74%) to a Pakistan strain. Compared with the reference strain S27, 37 non-structural and 28 structural protein amino acid substitutions had been detected in Tianjin CHIKV genome, including two key site mutations, E1-D284E and E2-I211T, in accordance with other strains in the ECSA cluster. Besides, Tianjin CHIKV possessed two point virulent residues at position 12 and 82 in E2, and also a nsP3-R524Opal nonsense mutation.Conclusions:Tianjin CHIKV showed stronger virulence and greater transmissibility in Aedes albopictus. Therefore, the surveillance and monitoring of CHIKV in China should be strengthened.

ObjectiveTo establish a method for the analysis of oligosaccharides in Atractylodes lancea rhizome based on ultra-performance liquid chromatography tandem quadrupole-time-of-flight mass spectrometry （UPLC-Q-TOF-MS） and a method for the quantification of oligosaccharides in A. lancea rhizome based on UPLC-evaporative light scattering detector （ELSD）， and to investigate the oligosaccharide characteristics of A. lancea rhizome from different habitats. MethodUPLC-Q-TOF-MS was used to identify the oligosaccharides in A. lancea rhizome with the mobile phase of 0.1% ammonia acetonitrile solution （A）-0.1% ammonia solution （B） for gradient elution （0-0.5 min， 98%A； 0.5-2.0 min， 98%-89%A； 2.0-2.5 min， 89%-86%A； 2.5-5.5 min， 86%-80%A； 5.5-6.5 min， 80%-72%A； 6.5-9.5 min， 72%-63%A； 9.5-14.0 min， 63%-50%A； 14.0-16.0 min， 50%A； 16.0-16.5 min， 50%-98%A； 16.5-20 min， 98%A）， the column temperature of 60 ℃ and the flow rate of 0.2 mL·min^-1. Electrospray ionization （ESI） was used to collect data in negative ion mode and the detection range was m/z 50-1 500. The qualitative analysis of oligosaccharides was accomplished by retention time， relative molecular weight， primary and secondary MS information of characteristic fragment ions in combination with reference substance information. UPLC-ELSD was employed to determine the contents of nine oligosaccharides in A. lancea rhizome with the mobile phase of 0.1% ammonia acetonitrile solution （A）-0.1% ammonia solution （B） for gradient elution （0-1 min， 98%-75%A； 1-7 min， 75%-70%A； 7-18 min， 70%-55%A； 18-23 min， 55%A； 23-23.5 min， 55%-98%A； 23.5-28 min， 98%A）， the drift tube temperature of ELSD was set at 50 ℃. Principal component analysis （PCA） and orthogonal partial least squares-discriminant analysis （OPLS-DA） were used to analyze the classification and differential components between A. lancea rhizome from different habitats. ResultA total of 24 oligosaccharides， containing 11 pairs of isomers， were identified from A. lancea rhizome. Among them， compared with samples from Anhui， Chongqing， Nanjing and Shaanxi， the contents of kestose（GF2）， 1F-fructofuranosylnystose （GF4）， kestohexose （GF5）， fructo-oligosaccharide DP10 （GF9） in samples from Maoshan were statistically significant （P<0.05）， and the total mass fraction of sucrose （GF1）-GF9 reached 16.47%. The peak area ratio of fructose-fructose oligosaccharide to its isomer sucrose-fructose oligosaccharide was greater than 1 in samples from Maoshan. ConclusionThe types and contents of oligosaccharides in A. lancea rhizome vary greatly among different habitats， and the peak area ratio of fructose-fructose oligosaccharide to sucrose-fructose oligosaccharide >1 may be one of the geoherb characteristics of A. lancea rhizome， which can provide a reference for the development， utilization and quality control of this herb.

Objective:To observe the efficacy of free transplantation of latissimus dorsi musculocutaneous flap and anterolateral femoral skin flap in repairing the wound after the resection of the scalp squamous cell carcinoma, and to explore the indications of these two skin flaps.Methods:The clinical data of patients with scalp squamous cell carcinoma admitted to the Plastic Surgery Department of the Second Affiliated Hospital of Kunming Medical University from June 2013 to May 2019 were analyzed retrospectively. All patients showed no cancer metastasis examined with CT. None of the patients had systemic diseases such as hypertension, diabetes, vascular disease. The wounds were repaired with free transplantation of latissimus dorsi myocutaneous flaps and anterolateral thigh flaps after extensive tumor resection. The intraoperative vascular variation, the diameter of the anastomosed blood vessel, the length of the vascular pedicle, the flap size, the time of harvesting the flap, the time for anastomosis, the operation time, and the incidences of complications at the donor site and recipient site were measured or recorded in both groups.Results:A total of 21 cases were included, including 14 males and 7 females, aged from 12 to 61 years. Eleven cases were repaired with the latissimus dorsi musculocutaneous flap, and 10 cases with the anterolateral thigh flap. All the 21 flaps survived during the 1 to 2 years follow-up. No vascular variation was found in the latissimus dorsi myocutaneous flap group, whereas 2 cases of vascular variation were found in the anterolateral thigh flap. In the latissimus dorsi myocutaneous flap group, the anastomotic vessel diameter was (2.14±0.09) mm for the artery and (2.49±0.10) mm for the vein. The vascular pedicle length was (6.14±0.28) cm, and the size of the flap was (135.0±20.8) cm 2, the harvesting time was (114.8±3.0) min, the vascular anastomosis time was (20.8±0.8) min, and the operation time was (6.5±0.2) h. In the anterolateral thigh flap group, the anastomotic vessel diameter was (2.15±0.14) mm for the artery and (2.45±0.15) mm for the vein. The vascular pedicle length was (6.80±0.31) cm, and the size of the flap was (159.9±16.4) cm 2, the harvesting time was (119.8±3.6) min, the vascular anastomosis time was (21.5±0.9) min, and the operation time was (6.9±0.2) h. There was no significant difference between the two kinds of flaps in the above parameter. The incidence of total complications at the donor site was higher in the latissimus dorsi myocutaneous flap group (7 cases) than that in the anterolateral thigh flap group (4 cases). The incidence of overall complications at the recipient was lower in the latissimus dorsi myocutaneous flap group (1 case) than that in the anterolateral thigh flap group (2 cases). Conclusions:Both the latissimus dorsi myocutaneous flap and the anterolateral femoral skin flap can achieve good results in repairing the wound after the resection of the scalp squamous cell carcinoma. The latissimus dorsi myocutaneous flap has a constant blood supply, and the operative technique is relatively easy and with low risk, which is more suitable for novices. The anterolateral thigh flap is thin and with fewer complications at the donor site. It is easy to be accepted by patients and can be performed in the supine position, which is more suitable for elderly patients.

Objective:To observe the efficacy of free transplantation of latissimus dorsi musculocutaneous flap and anterolateral femoral skin flap in repairing the wound after the resection of the scalp squamous cell carcinoma, and to explore the indications of these two skin flaps.Methods:The clinical data of patients with scalp squamous cell carcinoma admitted to the Plastic Surgery Department of the Second Affiliated Hospital of Kunming Medical University from June 2013 to May 2019 were analyzed retrospectively. All patients showed no cancer metastasis examined with CT. None of the patients had systemic diseases such as hypertension, diabetes, vascular disease. The wounds were repaired with free transplantation of latissimus dorsi myocutaneous flaps and anterolateral thigh flaps after extensive tumor resection. The intraoperative vascular variation, the diameter of the anastomosed blood vessel, the length of the vascular pedicle, the flap size, the time of harvesting the flap, the time for anastomosis, the operation time, and the incidences of complications at the donor site and recipient site were measured or recorded in both groups.Results:A total of 21 cases were included, including 14 males and 7 females, aged from 12 to 61 years. Eleven cases were repaired with the latissimus dorsi musculocutaneous flap, and 10 cases with the anterolateral thigh flap. All the 21 flaps survived during the 1 to 2 years follow-up. No vascular variation was found in the latissimus dorsi myocutaneous flap group, whereas 2 cases of vascular variation were found in the anterolateral thigh flap. In the latissimus dorsi myocutaneous flap group, the anastomotic vessel diameter was (2.14±0.09) mm for the artery and (2.49±0.10) mm for the vein. The vascular pedicle length was (6.14±0.28) cm, and the size of the flap was (135.0±20.8) cm 2, the harvesting time was (114.8±3.0) min, the vascular anastomosis time was (20.8±0.8) min, and the operation time was (6.5±0.2) h. In the anterolateral thigh flap group, the anastomotic vessel diameter was (2.15±0.14) mm for the artery and (2.45±0.15) mm for the vein. The vascular pedicle length was (6.80±0.31) cm, and the size of the flap was (159.9±16.4) cm 2, the harvesting time was (119.8±3.6) min, the vascular anastomosis time was (21.5±0.9) min, and the operation time was (6.9±0.2) h. There was no significant difference between the two kinds of flaps in the above parameter. The incidence of total complications at the donor site was higher in the latissimus dorsi myocutaneous flap group (7 cases) than that in the anterolateral thigh flap group (4 cases). The incidence of overall complications at the recipient was lower in the latissimus dorsi myocutaneous flap group (1 case) than that in the anterolateral thigh flap group (2 cases). Conclusions:Both the latissimus dorsi myocutaneous flap and the anterolateral femoral skin flap can achieve good results in repairing the wound after the resection of the scalp squamous cell carcinoma. The latissimus dorsi myocutaneous flap has a constant blood supply, and the operative technique is relatively easy and with low risk, which is more suitable for novices. The anterolateral thigh flap is thin and with fewer complications at the donor site. It is easy to be accepted by patients and can be performed in the supine position, which is more suitable for elderly patients.

Objective: To describe the epidemiological characteristics of a cluster of COVID-19 cases reported in Baodi district of Tianjin as of 18 February, 2020, which might be associated with the exposure in a local department store, and provide suggestions for prevention and control strategy development. Methods: The basic characteristics, time and area distributions, clinical manifestations, epidemiological history and transmission mode of the COVID-19 cases associated with the department store exposure were analyzed. Results: A total of 40 COVID-19 cases were associated with the department store exposure, accounting for 75.47% of the total confirmed cases (53 cases) reported in Baodi district. The cases were mainly at the age of 60 years or older (35.00%) and farmers (40.00%). The main clinical manifestations included fever (95.00%), cough (35.00%), and diarrhea (15.00%). The proportion of confirmed severe cases was 32.50%. The incidence curve showed that the incidence peak occurred on 31 January, 2020. Among the 40 cases, 6(15.00%) were department store employees, 19(47.50%) were customers and 15(37.50%) were close contacts (secondary cases). The first case occurred on 21 January, 2020, this case was a department store employee who had a purchasing history at whole sale markets in other provinces and cities before the onset, and 3 employees were still on duty after symptom onsets. The median of the incubation period of customer cases was 6 days, and the median of the interval between onset and medical treatment of customer cases was 7 days. Conclusion This was a cluster epidemic of COVID-19, which might be associated with the exposure in the department store. By now, the current prevention and control measures have achieved satisfied effects.

Objective:To investigate the drug resistance and pathogenic mechanism of a uropathogenic Escherichia coli (UPEC) strain UPEC132 at the genome-wide level. Methods:The susceptibility of UPEC132 strain to 16 antimicrobial agents was determined by minimum inhibitory concentration (MIC) assay. The UPEC132 strain was genotyped by multilocus sequence typing (MLST). The three-generation sequencing platform was used to sequence and assemble the whole genome of the UPEC132 strain. Drug resistance and virulence gene function annotations were predicted by Prodigal software and screened by using genome database. Genome sequences of the UPEC132 strain and 23 other UPEC strains collected from GenBank were phylogenetically analyzed, and a phylogenetic tree was constructed by RAxML software.Results:The UPEC132 strain was resistant to ampicillin, ampicillin/sulbactam, tetracycline, erythromycin, chloramphenicol and cefazolin. Its genotype was ST10522 by MLST. The whole genome of the UPEC132 strain included one complete genome (chromosome) and two plasmid sequences. The sequence sizes of the chromosome and plasmids 1 and 2 were 5 234 468 bp, 117 139 bp and 101 356 bp, and the guanine-cytosine (GC) content was 50.48%, 49.05%, and 54.04%, respectively. There were 4 856, 140 and 116 genes annotated in the chromosome and plasmids 1 and 2, respectively. Drug resistance genes were mainly distributed in the chromosomal genome, mainly including the multidrug resistance efflux pump gene clusters. Only blaTEM-1 and tetG genes were carried in the plasmid 2. Virulence genes were also mainly distributed in the chromosome genome, including nine pilus adhesins, five iron uptake systems and three secretory toxins. Gene clusters encoding Afa and type Ⅳ fimbriae were located on plasmids 1 and 2, respectively. The phylogenetic tree showed that the UPEC132 strain was not in the same branch with either of the 23 UPEC strains. Conclusions:The UPEC132 strain belonged to ST10522, which was a newly named ST type of Escherichia coli and first reported at home and abroad. The genome-wide genetic information of the UPEC132 strain was fully revealed. The multidrug resistance genes and virulence genes carried by the UPEC132 strain were associated with its drug resistance and pathogenicity.