[Investigation and factor analysis of postoperative surgical site infections in emergency abdominal surgery in China from 2018 to 2021 based on Chinese SSI Surveillance]

Objective: We investigated the incidence of surgical site infection (SSI) following emergency abdominal surgery (EAS) in China and further explored its risk factors, providing a reference for preventing and controlling SSI after EAS. Methods: This was an observational study. Data of patients who had undergone EAS and been enrolled in the Chinese SSI Surveillance Program during 2018-2021were retrospectively analyzed. All included patients had been followed up for 30 days after surgery. The analyzed data consisted of relevant patient characteristics and perioperative clinical data, including preoperative hemoglobin, albumin, and blood glucose concentrations, American Society of Anesthesiologists (ASA) score, grade of surgical incision, intestinal preparation, skin preparation, location of surgical site, approach, and duration. The primary outcome was the incidence of SSI occurring within 30 days following EAS. SSI was defined as both superficial and deep incisional infections and organ/space infections, diagnoses being supported by results of microbiological culture of secretions and pus. Secondary outcomes included 30-day postoperative mortality rates, length of stay in the intensive care unit (ICU), duration of postoperative hospitalization, and associated costs. The patients were classified into two groups, SSI and non-SSI, based on whether an infection had been diagnosed. Univariate and multivariate logistic regression analyses were performed to identify risk factors associated with SSI following EAS. Results: The study cohort comprised 5491 patients who had undergone EAS, comprising 3169 male and 2322 female patients. SSIs were diagnosed in 168 (3.1%) patients after EAS (SSI group); thus, the non-SSI group consisted of 5323 patients. The SSIs comprised superficial incision infections in 69 (41.1%), deep incision infections in 51 (30.4%), and organ or space infections in 48 (28.6%). Cultures of secretions and pus were positive in 115 (68.5%) cases. The most frequently detected organism was Escherichia coli (47/115; 40.9%). There were no significant differences in sex or body mass index between the SSI and non-SSI groups (both P>0.05). However, the proportion of individuals aged 60 years or older was significantly greater in the SSI than in the non-SSI group (49.4% [83/168] vs. 27.5% [1464/5323), χ2=38.604, P<0.001). Compared with the non-SSI group, the SSI group had greater proportions of patients with diabetes (11.9% [20/168] vs. 4.8% [258/5323], χ2=16.878, P<0.001), hypertension (25.6% [43/168] vs. 12.2% [649/5323], χ2=26.562, P<0.001); hemoglobin <110 g/L (27.4% [46/168] vs. 13.1% [697/5323], χ2=28.411, P<0.001), and albuminemia <30 g/L (24.4% [41/168] vs. 5.9% [316/5323], χ2=91.352, P<0.001), and a reduced rate of preoperative skin preparation (66.7% [112/168] vs. 75.9% [4039/5323], χ2=7.491, P=0.006). Furthermore, fewer patients in the SSI group had preoperative ASA scores of between one and two (56.0% [94/168] vs. 88.7% [4724/5323], χ2=162.869, P<0.001) in the non-SSI group. The incidences of contaminated and infected incisions were greater in the SSI group (63.1% [106/168] vs. 38.6% [2056/5323], χ2=40.854, P<0.001). There was a significant difference in surgical site distribution between the SSI and non-SSI groups (small intestine 29.8% [50/168] vs. 10.6% [565/5323], colorectal 26.2% [44/168] vs. 5.6% [298/5 323], and appendix 24.4% [41/168] vs. 65.1% [3465/5323]) χ2=167.897, P<0.001), respectively. There was a significantly lower proportion of laparoscope or robotic surgery in the non-SSI group (24.4 % [41/168] vs. 74.2% [3949/5323], χ2=203.199, P<0.001); the percentage of operations of duration less than 2 hours was significantly lower in the SSI than non-SSI group (35.7% [60/168] vs. 77.4% [4119/5323], χ2=155.487, P<0.001). As to clinical outcomes, there was a higher 30-day postoperative mortality rate (3.0%[5/168] vs. 0.2%[10/5323], χ2=36.807, P<0.001) and higher postoperative ICU occupancy rate (41.7% [70/168] vs. 19.7% [1046/5323], χ2=48.748, P<0.001) in the SSI group. The median length of stay in the ICU (0[2] vs. 0[0] days, U=328597.000, P<0.001), median total length of stay after surgery (16[13] vs. 6[5] days, U=128146.000, P<0.001), and median hospitalization cost (ten thousand yuan, 4.7[4.4] vs. 1.7[1.8], U=175965.000, P<0.001) were all significantly greater in the SSI group. Multivariate logistic regression analysis revealed that the absence of skin preparation before surgery (OR=2.435,95%CI: 1.690-3.508, P<0.001), preoperative albuminemia <30 g/L (OR=1.680, 95%CI: 1.081-2.610, P=0.021), contaminated or infected incisions (OR=3.031, 95%CI: 2.151-4.271, P<0.001), and laparotomy (OR=3.436, 95% CI: 2.123-5.564, P<0.001) were independent risk factors of SSI. Operative duration less than 2 hours (OR=0.465, 95%CI: 0.312-0.695, P<0.001) and ASA score of 1-2 (OR=0.416, 95% CI: 0.289-0.601, P<0.001) were identified as independent protective factors for SSI. Conclusions: It is important to consider the nutritional status in the perioperative period of patients undergoing EAS. Preoperative skin preparation should be conducted and, whenever possible, laparoscope or robot-assisted surgery. Duration of surgery should be as short as possible while maintaining surgery quality and improving patient care.

[Preliminary report on the use of total lumpectomyconical remnant gastric - esophagus side overlap anastomosis in radical resection of Siewert type II proximal gastric cancer]

Objective: There is no standard method for esophageal remnant gastric reconstruction for proximal gastrectomy. Reflux esophagitis caused by esophagogastrostomy remains a difficult surgical problem. To report the preliminary surgical results of novel esophagus-conical remnant gastric side overlap anastomosis (CGEO) , with particular emphasis on postoperative esophageal reflux. Methods: In June 2022, we developed a novel CGEO for laparoscopic proximal gastrectomy on two patients with Siewert type II esophagogastric junction adenocarcinoma. Surgical procedures for CGEO: (1) Laparoscopic proximal gastrectomy and preparation of conically shaped gastric remnant; (2) Determining anastomotic site of residual stomach and esophagus; (3) Side-to-side anastomosis of right esophageal wall to anterior of conical gastric remnant; (4) Valvuloplasty of esophageal stump. Results: Case 1 was a 71-year-old man with an operation time of 305 minutes and was successfully discharged from the hospital on the 9th day after surgery, and the postoperative pathology was T3N0M0. Case 2 was an 82-year-old man with an operation time of 325 minutes. He was discharged on the 10th day after surgery. In both cases, only mild esophageal mucosal changes were seen in gastroscopy, there were no obvious symptoms of esophageal reflux. There was also no significant weight change at half a year after operation. Conclusion: CGEO is moderately safe in radical surgery for proximal gastric cancer, and may have a preventive effect on the occurrence of postoperative esophageal reflux, but long-term results need to be confirmed by further studies with follow-up.

[Etiological analysis on a foodborne disease outbreak caused by two serotypes of Salmonella]

Objective: To understand the etiological characteristics of 2 serotypes of Salmonella strains isolated from a foodborne disease outbreak. Methods: A total of 11 anal swabs of the cases, 13 suspected contaminated food and 10 environmental samples were collected from a foodborne disease outbreak occurred on September 8, 2022 in a school. The anal swabs were enriched with selenite brilliant green enrichment broth (SBG) and brain heart infusion broth (BHI) respectively. PCR detection and culture of common intestinal pathogens were carried out. The suspected food samples were tested according to national standards for food safety. Multiple suspected Salmonella colonies were obtained and selected for serotype determination and whole genome sequencing. Serotypes were determined based on the whole-genome sequence, and clustering analysis was performed based on core genome single nucleotide polymorphism (SNP). Results: The positive rates of Salmonella in anal swabs and suspected food samples were 9/11 and 5/13 respectively. Both Salmonella Uganda and Salmonella Idikan were isolated from 4 anal swabs and 4 suspected food samples. For the remaining samples, only Salmonella Uganda or Salmonella Idikan was isolated in each sample. The positive rate of Salmonella in 11 anal swabs of the cases after BHI enrichment for 12 h and 24 h were all 9/11 in real-time PCR, same to the culture results. Salmonella Uganda and Salmonella Idikan formed two independent and genetically distant lineages in the clustering tree based on core genome SNP, and 0-14 and 0-23 SNP were observed in Salmonella Uganda and Salmonella Idikan respectively. Conclusions: This foodborne disease outbreak was probably caused by Salmonella Uganda and Salmonella Idikan, which both exhibited strong genetic diversity. The PCR based pathogen screening strategy plus pathogen enrichment for cases' annal swabs can be used in the routine outbreak investigation.

[VOCs Emission Level and Emission Reduction Potential of Coating Industry in Zibo]

To evaluate the emission level and emission reduction potential of volatile organic compounds (VOCs) in the coating industry in Zibo, we conducted field research on eight typical enterprises in three representative coating industries:the automobile manufacturing coating industry, wooden furniture coating industry, and metal surface coating industry. The actual measurement method, material balance algorithm, and emission factor method were used to calculate the VOC emissions of enterprises, and the localized emission factors were established. The emission levels of enterprises were evaluated by comparing with other domestic and foreign studies including AP-42, and the emission reduction potential was calculated based on the material balance algorithm. The significance difference analysis method was used to study the influence degree of each link management and control. The results showed that the VOC emission factor in Zibo was 4.38 kg·car-1 for the automobile manufacturing coating industry, 212.52 g·kg-1 paint for the wooden furniture industry, and 42.79 g·kg-1 paint for the metal surface painting industry. The source emission reduction potential of furniture enterprise C and the process emission reduction potential of metal enterprises G and F could reach more than 50%. The degree of influence of each link management and control from high to low was source>process>end.

[Comparison of two child growth standards in assessing the nutritional status of children under 6 years of age]

Objective: To compare the application of China growth standard for children under 7 years of age (China standards) and World Health Organization child growth standards (WHO standards) in evaluating the prevalence of malnutrition in children aged 0-<6 years in China. Methods: The research data came from the national special program for science & technology basic resources investigation of China, named "2019-2021 survey and application of China's nutrition and health system for children aged 0-18 years". Multi-stage stratified random sampling was used to recruit 28 districts (regions) in 14 provinces, autonomous regions or municipalities across the country. Children (n=38 848) were physically measured and questionnaires were conducted in the guardians of the children. The indicators of stunting, underweight, wasting, overweight and obesity were evaluated by China standards and WHO standards respectively. Chi-square test was used to comparing the prevalence of each nutritional status between the two standards, as well as the comparison between the two standards by gender and age. Results: Among the 38 848 children, 19 650 were boys (50.6%) and 19 198 were girls (49.4%), 19 480 urban children (50.1%) and 19 368 rural children (49.9%). The stunting, underweight and wasting cases in the study population were 2 090 children (5.4%), 1 354 children (3.5%) and 1 276 children (3.3%) according to the China standards, and 1 474 children (3.8%), 701 children (1.8%) and 824 children (2.1%) according to the WHO standards, respectively; the above rates according to the China standards were slightly higher than those to the WHO standards (χ²=111.59, 213.14, and 99.99, all P<0.001). The overweight and obesity cases in the study population were 2 186 children (5.6%) and 1 153 children (3.0%) according to the China standards, and 2 210 children (5.7%) and 1 186 children (3.1%) according to the WHO standards, with no statistically significant differences (χ²=0.14 and 0.48, P=0.709 and 0.488, respectively). Compared to the results based on WHO standards, the China standards showed a lower prevalence of overweight and obesity in boys (χ²=14.95 and 5.85, P<0.001 and =0.016, respectively), and higher prevalence of overweight in girls (χ²=12.60, P<0.001); but there was no statistically significant differences in girls' obesity prevalence between the two standards (χ²=2.62, P=0.106). Conclusions: In general, the prevalence of malnutrition among children aged 0-<6 years based on China standards is slightly higher than that on WHO standards. To evaluate the nutritional status of children, it is advisable to select appropriate child growth standards based on work requirements, norms or research objectives.

[Association between metabolism-related chronic disease combination and prevalence of non-alcoholic fatty liver disease in community residents in Shanghai]

Objective: To explore the combination of metabolism-related chronic diseases associated with the prevalence of non-alcoholic fatty liver disease (NAFLD) in community residents in Shanghai. Methods: The baseline data of Shanghai Suburban Adult Cohort and Biobank were used to understand the prevalence of five metabolism-related chronic diseases, including obesity, hypertension, hyperlipidemia, gout and diabetes, based on questionnaire survey, physical examination and blood biochemical detection. NAFLD was diagnosed by B-ultrasound detection and questionnaire. Multivariable logistic regression model was used to analyze the association of 31 metabolism-related chronic diseases combinations with the prevalence of NAFLD. Results: The median age (Q1, Q3) of 65 477 subjects was 60 (51, 66) years, and men accounted for 40.6%. The overall prevalence of NAFLD was 38.2%, and the prevalence of HAFLD in patients without any of the five metabolism-related chronic diseases was 12.0%. The chronic disease combination with the strongest association with NAFLD was obesity + hypertension + hyperlipidemia + gout + diabetes in the total population (OR=37.94, 95%CI: 31.02-46.41), in women (OR=36.99, 95%CI: 28.78-47.54) and in age group ≥60 years (OR=36.19, 95%CI: 28.25-46.36). The chronic disease combination with the strongest association with NAFLD was obesity + hyperlipidemia + gout + diabetes in men (OR=50.70, 95%CI: 24.62-104.40) and in age group <60 years (OR=49.58, 95%CI: 24.22-101.47). Conclusions: The prevalence of NAFLD in community residents in Shanghai was high. Attention needs to be paid to health of obese people and weight loss should be promoted for them. Community health education should be strengthened for patients complicated with gout, diabetes, hyperlipidemia and hypertension and it is necessary to correct abnormal serum uric acid, blood sugar, blood lipids and blood pressure in a timely manner to reduce the risk of NAFLD.

[Three-dimensional finite element study on the effects of maxillary anterior two-step retraction and en-masse retraction with clear aligners]

Objective: To investigate the effects of two-step retraction and en-masse retraction on tooth movement pattern of anterior teeth and posterior anchorage with clear aligners using three-dimensional finite element analysis. Methods: A finite element model of maxillary first premolar extraction case undergoing clear aligner treatment was established based on maxillofacial cone-beam CT data of a 24-year-old adult male with individual normal occlusion, who visited Department of Oral Surgery, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine for impacted mandibular third molar in June, 2022. The initial tooth displacement of five anterior retraction protocols (two-step with canine retraction, two-step with incisor bodily retraction, two-step with incisor retraction-overtreatment, en-masse bodily retraction, and en-masse retraction-overtreatment) were evaluated. Results: Two step with canine retraction caused distal tipping of the canine and labial tipping of the incisors (0.18° for central incisor and 0.13° for lateral incisor). Two step with incisor retraction caused mesial tipping of the canine. In two step with bodily retraction protocol, uncontrolled lingual tipping was found in central incisor (0.29°) and lateral incisor (0.32°). In two-step with incisor retraction-overtreatment protocol, the movement pattern of the incisors didn't change, but the inclinations reduced to 0.21° and 0.18°. En-masse retraction caused distal tipping of the canine. In en-masse bodily retraction protocol, uncontrolled lingual tipping was also found in central incisor (0.19°) and lateral incisor (0.27°). In en-masse retraction-overtreatment protocol, the central incisor showed controlled lingual tipping (0.02°) and the lateral incisor showed palatal root movement (0.03° labial inclination). Posterior teeth exhibited mesial tipping in all five protocols. Conclusion: En-masse retraction with incisor overtreatment was beneficial to incisor torque control in clear aligner treatment.

[Clinical effects of plantar split-thickness skin grafts in repairing the deep burn wounds in the back and buttocks]

Objective: To explore the clinical effects of plantar split-thickness skin grafts in repairing the deep burn wounds in the back and buttocks. Methods: A retrospective observational study was conducted. From January 2011 to February 2022, 98 patients with deep burn who met the inclusion criteria were admitted to the 910th Hospital of Joint Service Support Unit of PLA, including 64 males and 34 females, aged 17 to 78 years, with total burn areas of 35%-95% total body surface area (TBSA). The area of full-thickness burns in the back and buttocks ranged from 5% to 17% TBSA and the wounds were repaired only using stamp-shaped split-thickness skin grafts from plantar areas of both feet or combined with Meek microskin grafts or stamp-shaped skin grafts from other sites. According to the times of skin graft harvesting from both soles, these patients were divided into one-harvesting group (29 cases), two-harvesting group (38 cases), three-harvesting group (21 cases), and four-harvesting group (10 cases). The area of skin grafts harvested each time from both soles, the healing time of donor sites after each skin graft harvesting, and the survival rate of plantar skin graft in recipient site at 7 days after each skin graft harvesting in 98 patients, the interval between two adjacent skin graft harvesting in 69 patients with skin grafts harvested twice or more, as well as the healing time of donor site and survival rate of skin graft in recipient site after the last skin graft harvesting from both soles of patients in the 4 groups were recorded. The patients were followed up to observe the appearance, texture, and scar in recipient site of plantar skin grafts as well as the scar and function in plantar donor sites. Data were statistically analyzed with one-way analysis of variance, Kruskal-Wallis test, and chi-square test. Results: In the 98 patients, the area of skin graft was 2.0%-4.5% ((3.4±0.6)%) TBSA harvested each time from both soles, the healing time of donor site after each skin graft harvesting was 7-10 (7.8±1.1) d, and the survival rate of plantar skin graft in recipient site at 7 days after each skin graft harvesting was 93% (92%, 95%). The interval between two adjacent skin graft harvesting in the 69 patients was 7-38 (11.2±0.5) d. The healing time of donor site and survival rate of skin graft in recipient site after the last skin graft harvesting from both soles of patients in the 4 groups showed no statistically significant differences (P>0.05). A total of 88 patients were followed up for 3 months to 5 years, the appearance in recipient site of plantar skin graft was smooth, the texture was firm, the scar hyperplasia was mild, and the area was compressive- and wear-resistant. Among them, the plantar donor site recovered well in 85 patients, without obvious scar hyperplasia and only 3 patients had small area of scar hyperplasia in the non-weight-bearing areas which did not affect walking or wearing shoes or socks. Ten patients were lost in the follow up after discharge. Conclusions: Stamp-shaped split-thickness skin grafts can be repeatedly harvested from both soles of patient to repair the deep burn wounds in the back and buttocks, with high survival rate of skin grafts, thus can reduce the burden of other donor sites. Moreover, the skin grafts have good wear-resistance and pressure-resistance, without affecting postoperative normal walk.

[Study on the features of Clostridioides difficile infection among diarrhea patients in Kunming from 2018 to 2020]

Objective: We analyze the characteristics of Clostridioides difficile (C. difficile) infection among diarrhea patients in Kunming from 2018 to 2020 and provide evidence for follow-up surveillance and prevention. Methods: A total of 388 fecal samples of diarrhea patients from four sentinel hospitals in Yunnan Province from 2018 to 2020 were collected. Real-time quantitative PCR was used to detect the fecal toxin genes of C. difficile. The positive fecal samples isolated the bacteria, and isolates were identified by mass spectrometry. The genomic DNA of the strains was extracted for multi-locus sequence typing (MLST). The fecal toxin, strain isolation, and clinical patient characteristics, including co-infection with other pathogens, were analyzed. Results: Among the 388 fecal samples, 47 samples with positive reference genes of C. difficile were positive, with a total positive rate of 12.11%. There were 4 (8.51%) non-toxigenic and 43 (91.49%) toxigenic ones. A total of 18 strains C. difficile were isolated from 47 positive specimens, and the isolation rate of positive specimens was 38.30%. Among them, 14 strains were positive for tcdA, tcdB, tcdC, tcdR, and tcdE. All 18 strains of C. difficile were negative for binary toxins. The MLST results showed 10 sequence types (ST), including 5 strains of ST37, accounting for 27.78%; 2 strains of ST129, ST3, ST54, and ST2, respectively; and 1 strain of ST35, ST532, ST48, ST27, and ST39, respectively. Fecal toxin gene positive (tcdB+) results were statistically associated with the patient's age group and with or without fever before the visit; positive isolates were only statistically associated with the patient's age group. In addition, some C. difficile patients have co-infection with other diarrhea-related viruses. Conclusions: The infection of C. difficile in diarrhea patients in Kunming is mostly toxigenic strains, and the high diversity of strains was identified using the MLST method. Therefore, the surveillance and prevention of C. difficile should be strengthened.

[Establishment of PCR assays and genetic polymorphism analysis of genes encoding Clostridium perfringens β2 toxin from different sources]

Objective: To establish and optimize PCR methods for the gene encoding of Clostridium perfringens β₂ toxin (cpb₂) and atypical-cpb₂ (aty-cpb₂), analyze the epidemiological characteristics and genetic polymorphism of the cpb₂ of Clostridium perfringens in 9 Chinese areas from 2016 to 2021. Methods: The cpb₂ of 188 Clostridium perfringens strains were examined by PCR; the cpb₂ sequences were acquired by whole-genome sequencing to analyze the genetic polymorphism. Using Mega 11 and the Makeblastdb tool, a phylogenetic tree, and cpb₂-library based on 110 strains carrying the cpb₂ were produced. Using the Blastn technique, a comparison was made to discover sequence similarity between consensus-cpb₂ (con-cpb₂) and aty-cpb₂. Results: The specificity of PCR assay for the cpb₂ and aty-cpb₂ was verified. The PCR results for cpb₂ amplification were highly consistent with the whole-genome sequencing approach (Kappa=0.946, P<0.001). A total of 107 strains from nine regions in China carried cpb₂, 94 types A strains carried aty-cpb₂, 6 types A strains carried con-cpb₂, and 7 types F strains carried aty-cpb₂. The nucleotide sequence similarity between the two coding genes was 68.97%-70.97%, and the similarity between the same coding genes was 98.00%-100.00%. Conclusions: In this study, a specific PCR method for cpb₂ toxin was developed, and the previous PCR method for detecting aty-cpb₂ was improved. aty-cpb₂ is the primary gene encoding of β₂ toxin. There is a significant nucleotide sequence variance between the various cpb₂ genotypes.

[Current status of lymph node dissection in pyloric-preserving gastrectomy for early gastric cancer]

With the gradual increase in the diagnosis rate of early gastric cancer, clinicians must consider prevention of gastric anatomical structure and physiological function while ensuring the radical treatment of the tumor. Pylorus-preserving gastrectomy is a function- preserving operation that preserves the pylorus, inferior pyloric vessel, and the vagus nerve in patients with early middle gastric cancer. One of the major controversies at present is the thoroughness of limited lymph node dissection for pyloric-preserving gastrectomy. Various studies have reported that the lymph node metastasis rate of early middle gastric cancer was low, especially in the suprapyloric region, inferior pylorus and the upper pancreatic region. Partial lymph node dissection is required for vascular and neurological protection, which is also safe and feasible in studies reported by major centers. Many clinical studies have been carried out in Japan and Korea, and postoperative follow-up has gradually increased evidence, providing the basis for the safety of lymph node dissection. In large case studies comparing pylorus- preserving gastrectomy with traditional distal gastrectomy, the incidence of postoperative morbidity, such as dumping syndrome, bile reflux esophagitis, weight loss, and malnutrition is low. Sentinel lymph node navigation technology is gradually applied to the diagnosis and treatment of early gastric cancer, and its clinical application value still needs further research.

Probiotic characterization and comparison of broiler-derived lactobacillus strains based on technique for order preference by similarity to ideal solution analysis

A total of 10 lactobacillus strains were isolated from broiler chickens and their probiotic properties including tolerance to gastrointestinal fluids and heat treatment, antimicrobial activity, adhesion capacity to intestinal cells, surface hydrophobicity, autoaggregation, antioxidative activity, and immunomodulatory effects on chicken macrophages were evaluated. The Limosilactobacillus reuteri (LR) was the most frequently isolated species, followed by Lactobacillus johnsonii (LJ) and Ligilactobacillus salivarius (LS). All isolates showed good resistance to simulated gastrointestinal conditions and antimicrobial activity against 4 indicator strains including Escherichia coli, Salmonella typhimurium, Klebsiella pneumoniae, and Proteus mirabilis LR 21 exhibited excellent performances on autoaggregation, hydrophobicity and adhesion capacity to Caco-2 intestinal cells. In the meantime, this strain also possessed considerable tolerance to heat treatment, which indicated great potential to be used in the feed industry. However, LJ 20 strain had the highest free radical scavenging activity compared with the other strains. Furthermore, qRT-PCR results revealed that all isolated strains significantly increased the transcriptional levels of proinflammatory genes and tended to induce the M1-type polarization on HD11 macrophages. Particularly, the technique for order preference by similarity to ideal solution (TOPSIS) was adopted in our study to compare and select the most promising probiotic candidate based on in vitro evaluation tests.

[The prevalence of atrial cardiomyopathy in patients with different types of acute ischemic stroke and its relationship with cryptogenic stroke]

Objective: To investigate the prevalence of atrial cardiomyopathy in patients with different types of acute ischemic stroke and its relationship with cryptogenic stroke. Methods: Patients with acute ischemic stroke within 7 days of onset who were admitted to the Department of Neurology of the First Affiliated Hospital of Zhengzhou University from January to September 2019 were prospectively and consecutively enrolled. All included patients were classified according to TOAST classification of ischemic stroke. Chi-square test was used to compare the prevalence of atrial cardiomyopathy among patients with different TOAST classifications. Multivariate logistic regression model was used to analyze the related factors of cryptogenic stroke. Results: A total of 1 098 patients with acute ischemic stroke were enrolled in the study, including 661 males and 437 females, with a median age [M(Q₁,Q₃)] of 61 (53, 68) years. The prevalence of atrial cardiomyopathy in patients with cryptogenic stroke[53.5% (46/86)] was higher than that in patients with large artery atherosclerosis [38.0%(63/166), P=0.018] and small vessel occlusion [19.4%(37/191), P<0.001], but was lower than that of patients in the cardioembolic group [97.3% (72/74), P<0.001]. Multivariate logistic regression analysis showed that atrial cardiomyopathy was an associated factor for cryptogenic stroke (OR=2.945, 95%CI: 1.766-4.911, P<0.001). Conclusions: Atrial cardiomyopathy is associated with cryptogenic stroke. The prevalence of atrial cardiomyopathy in patients with cryptogenic stroke is higher than that in patients with large artery atherosclerosis and small vessel occlusion, but lower than that in patients with cardiac embolism.

[Progress in research of Clostridium perfringens toxin]

Clostridium perfringens can produce many kinds of toxins and hydrolase, causing gas gangrene, enteritis and enterotoxemia in both human and animals. It is known that C. perfringens can produce more than 20 toxins and hydrolases. The different toxin types are associated with specific disease types. At present, molecular toxin-typing method by PCR has replaced the traditional serological typing method. In this study, we systematically summarize the types, basic characteristics, pathogenic mechanism and the relationship with disease of C. perfringens toxins to provide evidence for the establishment of rapid detection method, immune antigen screening, antibody preparation and research of related pathogenic mechanism.

Observation of an Isoscalar Resonance with Exotic J^{PC}=1^{-+} Quantum Numbers in J/ψ→γηη^{'}

Using a sample of (10.09±0.04)×10^{9}  J/ψ events collected with the BESIII detector operating at the BEPCII storage ring, a partial wave analysis of the decay J/ψ→γηη^{'} is performed. The first observation of an isoscalar state with exotic quantum numbers J^{PC}=1^{-+}, denoted as η_{1}(1855), is reported in the process J/ψ→γη_{1}(1855) with η_{1}(1855)→ηη^{'}. Its mass and width are measured to be (1855±9_{-1}^{+6})  MeV/c^{2} and (188±18_{-8}^{+3})  MeV, respectively, where the first uncertainties are statistical and the second are systematic, and its statistical significance is estimated to be larger than 19σ.

[Analysis of epidemiological characteristics of bacillary dysentery with multiple-onset in Henan Province from 2005 to 2020]

Objective: To understand the epidemiological characteristics of bacillary dysentery with multiple-onset in Henan province from 2005 to 2020. Methods: The reported cases of bacillary dysentery (including confirmed cases and clinically diagnosed cases) in Henan Province from January 2005 to December 2020 were collected through China's National Disease Supervision Information Management System. The main information included gender, age, home address, date of onset and date of diagnosis. The interval between two episodes of the same case was more than 15 days, which was judged as two episodes. The incidence characteristics of bacillary dysentery patients with two or more cases in Henan Province from 2005 to 2020 were analyzed, and the regional distribution map of cases was drawn using ArcGIS software. Results: From 2005 to 2020, a total of 250 430 cases of bacillary dysentery were reported in Henan Province, with a cumulative incidence rate of 228.66/100 000. There were 2 342 cases with two or more attacks. The incidence of recurrent cases of bacillary dysentery increased year by year (χ²_trend=2 932.28, P<0.001). There was no significant difference in the incidence of two or more cases of different sexes (χ²=0.39, P=0.540). There was significant difference in the incidence among different age groups (χ²=438.40, P<0.001). The incidence of two or more cases in the 60-69 age group was relatively high (1.70%). The shortest time interval between the onset of the disease was 16 days, and the longest was 5 579 days, with M (Q₁, Q₃) about 428 (237, 843) days. Compared with healthy people, those with a history of bacterial diseases had a higher risk of developing bacillary dysentery (RR: 4.12, 95%CI: 3.95‒4.29). Conclusion: The proportion of patients with multiple-onset shows an increasing trend, and there is an age difference.

Two New C21 Steroidal Glycosides from Selaginella Braunii Baker

Two new C21 steroidal glycosides, brapreguanes A and B (1-2) were isolated from 75 % aqueous ethanol extract of Selaginella braunii Baker. Their structures were established by spectroscopic analyses (1D/2D NMR spectra and HR-ESI-MS). The absolute configurations of sugar were elucidated by enzymatic hydrolysis and GCMS analysis. In addition, all compounds were evaluated for the anti-proliferative activities against various human cancer cells in vitro. Compounds exhibited no inhibition to various human cancer cells.

First Observation of the Direct Production of the χ_{c1} in e^{+}e^{-} Annihilation

We study the direct production of the J^{PC}=1^{++} charmonium state χ_{c1}(1P) in electron-positron annihilation by carrying out an energy scan around the mass of the χ_{c1}(1P). The data were collected with the BESIII detector at the BEPCII collider. An interference pattern between the signal process e^{+}e^{-}→χ_{c1}(1P)→γJ/ψ→γμ^{+}μ^{-} and the background processes e^{+}e^{-}→γ_{ISR}J/ψ→γ_{ISR}μ^{+}μ^{-} and e^{+}e^{-}→γ_{ISR}μ^{+}μ^{-} is observed by combining all the data samples. The χ_{c1}(1P) signal is observed with a significance of 5.1σ. This is the first observation of a C-even state directly produced in e^{+}e^{-} annihilation. The electronic width of the χ_{c1}(1P) resonance is determined to be Γ_{ee}=(0.12_{-0.08}^{+0.13})  eV, which is of the same order of magnitude as theoretical calculations.

A minimized and efficient low temperature loading device for indentation

A minimized and efficient low temperature loading device cooling with Peltier coolers for indentation test is developed. Both specimen and indentation tip are immersed in 50% methanol-water solution, totally eliminating the contact thermal drift problem. Low temperature indentation tests down to 253.8 K can be realized within 10 min. The size of the device is miniaturized within 50 × 40 × 30 mm³, and no vacuum environment is required. Monocrystalline copper is tested to perform the feasibility of the device. Based on the simple structure and stable experimental effect, the developed device can be integrated into various types of current indentation devices to attach low temperature testing ability.

[Labor progression characteristics of primiparous term singleton pregnant women complicated with adenomyosis]

Objective: To analyze the labor progression characteristics of primiparous term singleton pregnant women with adenomyosis. Methods: From April 2014 to May 2021, pregnant women underwent regular antenatal examination in Peking University Third Hospital were enrolled in this retrospective study, 109 primiparous term pregnant women with adenomyosis who underwent singleton, primipara, cephalic and vaginal delivery were referred as the adenomyosis group, while 109 pregnant women without adenomyosis primiparous term pregnant women at the same time were referred as the control group. The general clinical information, labor process intervention, pregnancy outcomes and labor course time of the two groups were analyzed. Results: (1) General clinical conditions: the pre-pregnancy uterine volume of the adenomyosis group was larger than that of the control group [(66.8±23.7) vs (41.4±13.1) cm³, P<0.05]. The proportion of assisted reproductive pregnancy and endometriosis in the adenomyosis group were higher than those in the control group [31.2% (34/109) vs 7.3% (8/109); 31.2% (34/109) vs 5.5% (6/109); all P<0.05]. There were no significant differences in maternal age, gestational age at delivery, pre-pregnancy body mass index, gestational weight gain, gravidity, incidence of pregnancy complications (gestational diabetes mellitus, pre-eclampsia and thyroid diseases) and premature rupture of membranes between the two groups (all P>0.05). (2) Labor process intervention and maternal and fetal outcomes: postpartum hemorrhage was higher in the adenomyosis group than the control group (median: 300 vs 260 ml, P=0.018). There were no significant differences in the proportion of labor onset, use of oxytocin, artificial rupture of membranes, perineal laceration Ⅲ and above, episiotomy, newborn weight and 1-minute Apgar score between the two groups (all P>0.05). (3) Time of labor process: there were no significant differences between the two groups in the time required for the first stage, third stage, total stage and cervical dilation 0-1, 1-2, 2-3, 3-4, 4-5, 5-6, 6-7 cm (all P>0.05). The time required for cervical dilation 7-8, 8-9, 9-10 cm and the second stage of labor in adenomyosis group (median: 20, 18, 15 and 12 minutes, respectively) were shorter than those of the control group (median: 23, 23, 23 and 26 minutes, respectively), and the differences were statistically significant (all P<0.05). (4) The effect of endometriosis on labor: there was no significant difference in the effect of endometriosis on labor in adenomyosis group (P>0.05). Conclusions: The labor process of primiparous term pregnant women with adenomyosis is significantly accelerated after the cervical dilatation for 7 cm, which should be closely observed. The third stage of labor course is managed aggressively with drugs to prevent postpartum hemorrhage.

[Prevalence and risk factors of silicosis complicated with chronic obstructive pulmonary disease]

Objective: To explore the prevalence, clinical characteristics and risk factors of chronic obstructive pulmonary disease (COPD) in silicosis patients. Methods: In May 2021, a cross-sectional study was used to retrospectively include 329 silicosis patients first diagnosed in Beijing Chaoyang Hospital from January 1, 2007 to December 31, 2020. The demographic data, occupational history, chest imaging, pulmonary function and blood routine indicators of silicosis patients with COPD were analyzed, and the risk factors of silicosis with COPD were analyzed by multiple logistic regression. Results: There were 128 patients with silicosis complicated with COPD, and the overall prevalence rate was 38.9% (128/329) . Among them, 73.4% (94/128) were male and 33.6% (43/128) were heavy smokers; 33.6% (43/128) of patients were classified as gold 1, 37.5% (48/128) as gold 2, 25.0% (32/128) as gold 3, and 3.9% (5/128) as gold 4. Diagnostic age (OR=1.04, 95%CI=1.02~1.06, P<0.001) , cumulative smoking (OR=1.03, 95%CI=1.01~1.05, P=0.008) and silicosis stage III (OR=7.06, 95% CI=4.00-12.46, P<0.001) were risk factors for silicosis complicated with COPD. Conclusion: Diagnostic age, cumulative smoking volume and third stage of silicosis are the risk factors of silicosis patients with different degrees of COPD, which should be paid attention to in clinical treatment.

[Application of three-dimensional visualized model of impacted tooth for surgical extraction in undergraduate oral experimental teaching]

Objective: To evaluate the effect of the application of a self-developed three-dimensional visualized model of impacted tooth for surgical extraction in undergraduate oral experimental teaching. Methods: Forty-one undergraduates majoring stomatology of Tongji University from 2018 [19 males and 22 females, aged (22.4±0.8) years] were enrolled and randomly divided into the conventional group and the experimental group. Students of the conventional group (21 students including 8 males and 13 females) received a teaching protocol for the surgical extraction of impacted tooth including theoretical lectures, watching operation videos, and operating on head-simulator teaching systems. Students of the experimental group (20 students including 11 males and 9 females) received an additional training of resistance assessment and surgical extraction using the three-dimensional visualized model of impacted tooth before operating on the head simulators. After class, a questionnaire survey was carried out among students, and the operation results on the head simulators were evaluated by the teacher. Results: The results of the questionnaire showed that the students in the experimental group were rated higher than those in the traditional group in terms of being able to imagine the relationship between impacted teeth and adjacent structures (U=114.00, P=0.006), avoiding damage to adjacent teeth (U=87.00, P<0.001) and inferior alveolar nerve during tooth extraction (U=111.50, P=0.006), and being more confident in clinical operations in the future (U=120.00, P=0.013). According to the evaluation results of tooth extraction on the head simulators, there was no significant difference in the operation time between the two groups (U=138.50, P=0.056). In the experimental group, 5% (1/20) caused adjacent tooth loosening and 15% (3/20) caused the excessive bone defect, which was less than those in the traditional group [38% (8/21) and 48% (10/21), respectively] (P=0.021; P=0.043). There was no significant difference in the incidence of grinding out the deep bone of impacted teeth between the two groups (P=0.232). Conclusions: The application of three-dimensional visualized model of impacted tooth for surgical extraction in undergraduate oral experimental teaching had achieved good results and was worth popularizing.

Observation of a State X(2600) in the π^{+}π^{-}η' System in the Process J/ψ→γπ^{+}π^{-}η'

Based on (10087±44)×10^{6}  J/ψ events collected with the BESIII detector, the process J/ψ→γπ^{+}π^{-}η^{'} is studied using two largest decay channels of the η^{'} meson, η^{'}→γπ^{+}π^{-} and η^{'}→ηπ^{+}π^{-}, η→γγ. A new resonance, which we denote as the X(2600), is observed with a statistical significance larger than 20σ in the π^{+}π^{-}η^{'} invariant mass spectrum, and it has a connection to a structure around 1.5  GeV/c^{2} in the π^{+}π^{-} invariant mass spectrum. A simultaneous fit on the π^{+}π^{-}η^{'} and π^{+}π^{-} invariant mass spectra with the two η^{'} decay modes indicates that the mass and width of the X(2600) state are 2618.3±2.0_{-1.4}^{+16.3}  MeV/c^{2} and 195±5_{-17}^{+26}  MeV, where the first uncertainties are statistical, and the second systematic.