Study on morphology optimization of open-pit mine slope based on section and spatial morphology effect

Reasonable design of the slopes of mining field is an important prerequisite for optimizing open-pit mine boundary, ensuring safe production and improving economic benefits of open-pit mines. This study took the open-pit coal mine coal mine in Block I of Thar coal field in Pakistan as the research background, based on the section morphology effect of slope stability and the occurrence characteristics of coal seam and weak layer, the section morphology of slope was optimized step by step from two-dimensional angle by using the rigid body limit equilibrium method. The three-dimensional numerical simulation method is used to analyze the three-dimensional spatial effect of slope stability and reveal the influence of the spatial geometry of the slope stability. The spatial morphology of the slope was optimized and the evolutionary mechanism of slope instability was revealed. By comparing the optimized slope morphology with the preliminary design and the slope morphology of the straight slope with equal flat plate, the economic benefits were further analyzed. The results showed that under the premise of meeting the safety reserve coefficient, compared with the preliminary design and the design of equal plate. The slope angle of the optimized section morphology was increased by 1° and 3° respectively, and the coal resource recovery was increased by 332 m2 and 1790 m2 respectively, and the economic benefits were $ 18,065,859 and $ 54,408,251 respectively. And the slope angle of the optimized spatial morphology was increased by 3° and 5° respectively, and the coal resource recovery was increased by 1188 m2 and 2726 m2 respectively, and the economic benefits were $ 72,082,808 and $ 108,417,368 respectively.

Norovirus outbreaks in hospitals in China: a systematic review

BACKGROUND

Norovirus outbreaks in hospitals can potentially impair patient care and result in significant financial expenses. There is currently limited information on hospital norovirus outbreaks in the Chinese mainland.

AIM

To systematically review the published literature to describe the characteristics of norovirus outbreaks in Chinese mainland hospitals to facilitate prompt identification and control of outbreaks.

METHODS

A systematic review was performed according to the Preferred Reporting Items for Systematic Review and Meta-Analysis standards. Databases including PubMed, Web of Science, and Chinese Journals Online databases (China National Knowledge Infrastructure (CNKI), Chinese Wan Fang digital database (WANFANG) were searched from inception to July 18th, 2022.

FINDINGS

A total of 41 norovirus Chinese hospital outbreaks occurring before July 18th, 2022 were reported in 32 articles. Most reported outbreaks were from Shanghai and Beijing, and occurred in December and January. Cases were mainly adults. The male:female ratio was 1.22:1. The majority of cases in norovirus outbreaks were hospitalized patients (56.82%); medical staff were affected in 15 outbreaks. Norovirus outbreaks occurred in both private and public hospitals, and in secondary and tertiary care centres, and occurred mainly in internal medicine and geriatric departments. Person-to-person transmission was the primary transmission mode and GII was more prevalent.

CONCLUSION

Norovirus outbreaks in hospitals can affect both patients and healthcare workers, sometimes causing serious financial losses. In order to have a more complete understanding of the disease burden caused by norovirus outbreaks, surveillance needs to be established in hospitals.

Landslide risk evaluation method of open-pit mine based on numerical simulation of large deformation of landslide

It is of great practical significance to carry out quantitative risk assessment of landslide disaster to protect people's lives and property safety and maintain the sustainable development of social economy. The delineation of landslide disaster range is the key link of landslide risk evaluation in open-pit mine. This study took the open-pit coal mine coal mine in Block I of Thar coal field in Pakistan as the research background, and constructed a framework for landslide risk evaluation in open-pit mines. Based on the numerical simulation method of large deformation of landslide, the disaster range of landslide in open-pit mine was delineated. The stability of stope slope was analyzed based on rigid body limit equilibrium method. The probability of landslide instability was calculated based on Monte Carlo method. And the comprehensive fuzzy evaluation model was established to calculate the total risk value of landslide. The results showed that: through numerical simulation and empirical formula calculation, the landslide disaster range was accurately delineated, and the comprehensive vulnerability of the disaster bearing body was determined to be medium vulnerability; the annual probability of landslide instability under natural conditions was 0.003, which belongs to moderate risk. The annual probability of landslide instability under rainstorm conditions was 0.024, which was highly dangerous; the annual probability of landslide instability under seismic conditions was 0.018, which was highly dangerous. Under natural conditions, the total risk value of landslide was 114,686.4 rmb, and the annual mortality rate of population was 0.0255 people/year. The total risk value of landslide under rainstorm condition was 11,707,570 rmb, and the annual mortality rate of population was 0.18375 people/year. The total risk value of landslide under earthquake condition was 43,007,400 rmb, and the annual mortality rate of population was 0.135 person/year, which was an unacceptable risk. The economic loss was a small geological disaster risk under natural conditions, and it was a medium-sized geological disaster risk under both rainstorm and earthquake conditions. Therefore, landslide prevention and control and management measures such as slope deformation monitoring were proposed to ensure the safety of personnel and property in open-pit mines.

[C2 pedicle screw insertion assisted by mobilization of the vertebral artery in cases with high-riding vertebral artery]

Objective: To examine the feasibility, safety, and efficacy of mobilization of the vertebral artery for C2 pedicle screws in cases with high-riding vertebral artery (HRVA). Methods: The clinical data of 12 patients with basilar invagination and atlantoaxial dislocation underwent atlantoaxial reduction and fixation in the Department of Neurosurgery, the First Affiliated Hospital of University of Science and Technology of China between January 2020 and November 2021 were retrospectively analyzed. All patients had high-riding vertebral artery on at least one side that prohibited the insertion of C2 pedicle screws. There were 2 males and 10 females aged (48.0±12.8) years (range: 17 to 67 years). After correction of vertical dislocation during the operation, the C2 pedicle screw insertion and occipitocervical fixation and fusion were performed using the vertebral artery mobilization technique. Neurological function was assessed using the Japanese Orthopedic Association (JOA) scale. The preoperative and postoperative JOA score and the main radiological measurements, including the anterior atlantodental interval (ADI), the distance of the odontoid tip above the Chamberlain line, the clivus-canal angle, were collected and compared by paired t-test. Results: Mobilization of the high-riding vertebral artery was successfully completed, and C2 pedicle screws were then fulfilled after the vertebral artery was protected. There was no injury to the vertebral artery during the operation. Meanwhile, no severe surgical complications such as cerebral infarction or aggravated neurological dysfunction occurred during the perioperative period. Satisfactory C2 pedicle screw placement and reduction were achieved in all 12 patients. All patients achieved bone fusion 6 months after surgery. No looseness and shift in internal fixation or reduction loss was observed during the follow-up period. Compared to the preoperative, the postoperative ADI decreased from (6.1±1.9) mm to (2.0±1.2) mm (t=6.73, P<0.01), the distance of the odontoid tip above the Chamberlain line decreased from (10.4±2.5) mm to (5.5±2.3) mm (t=7.12, P<0.01), the clivus-canal angle increased from (123.4±11.1) ° to (134.7±9.6) ° (t=2.50, P=0.032), the JOA score increased from 13.3±2.1 to 15.6±1.2 (t=6.99, P<0.01). Conclusion: The C2 pedicle screw insertion assisted by mobilization of the vertebral artery is safe and considerably effective, providing a choice for internal fixation in cases with high-riding vertebral arteries.

[Clinicopathological characteristics of gastric SMARCA4-deficient undifferentiated/rhabdoid carcinoma]

Objective: To investigate the clinicopathological features and immunohistochemical phenotypes of gastric SMARCA4-deficient undifferentiated carcinoma, and to discuss the daily diagnostics of this entity and analyze its prognosis. Methods: The cases of gastric SMARCA4-deficient undifferentiated carcinoma diagnosed at the Department of Pathology, Peking University Cancer Hospital, China from January 2010 to August 2022 were collected. The histological sections were reviewed, the immunohistochemical results and clinicopathological features were analyzed, and relevant literature was reviewed. Results: Pure foci of undifferentiated carcinoma were seen in 7 cases, and 1 case was accompanied by a moderately differentiated tubular adenocarcinoma component. Undifferentiated carcinoma foci showed similar sheet-like or solid diffuse growth pattern, medium-sized tumor cells characterized by 1-2 nucleoli, and abundant cytoplasm and rhabdoid appearance. The average patient age was 65±8 years. Six patients were male and 2 were female. Immunohistochemical staining showed that undifferentiated carcinoma of all 8 tumors were negative for SMARCA4 (BRG1). Among 7 patients who underwent SMARCA2 (BRM) and SMARCB1 (INI1) staining, 4 cases showed loss of BRM expression, 2 cases showed weakly positive staining, and 1 case was diffusely positive, but all 7 cases were diffusely strong positive for INI1. The neuroendocrine marker, synaptophysin, was weakly positive in 5 cases, while CgA and CD56 were negative in 8 cases. Ki-67 index was more than 70%. Two cases were mismatch repair deficient and showed the loss of MLH1/PMS2 expression, while 1 case showed only MSH2 loss. PD-L1 staining showed that combined positive score (CPS)≥1 in 4 cases (CPS ranging from 1 to 55) and CPS<1 in the other 3 cases. Four patients had clinical stage Ⅳ disease. Two of them died within 3 months after diagnosis. Conclusions: Gastric SMARCA4-deficient undifferentiated carcinoma/rhabdoid carcinoma is a rare group of highly malignant tumors with a poor prognosis. Loss of the core subunit of SWI/SNF complex may be associated with the development of dedifferentiated histological pattern and aggressive tumor progression, which may be more frequently accompanied with mismatch repair deficiency.

[Analysis on infection sources and transmission chains of three outbreaks caused by 2019-nCoV Omicron variant in Beijing, China]

Objective: To investigate the infection sources and the transmission chains of three outbreaks caused by 2019-nCoV Omicron variant possibly spread through cross-border logistics in Beijing. Methods: Epidemiological investigation and big data were used to identify the exposure points of the cases. Close contacts were traced from the exposure points, and the cases' and environmental samples were collected for nucleic acid tests. Positive samples were analyzed by gene sequencing. Results: The Omicron variant causing 3 outbreaks in Beijing from January to April, 2022 belonged to BA.1, BA.1.1 and BA.2. The outbreaks lasted for 8, 12 and 8 days respectively, and 6, 42 and 32 cases infected with 2019-nCoV were reported respectively. International mail might be the infection source for 1 outbreak, and imported clothes might be the infection sources for another 2 outbreaks. The interval between the shipment start time of the imported goods and the infection time of the index case was 3-4 days. The mean incubation period (Q₁, Q₃) was 3 (2,4) days and the mean serial interval (Q₁, Q₃) was 3 (2,4)days. Conclusions: The 3 outbreaks highlighted the risk of infection by Omicron variant from international logistics-related imported goods at normal temperature. Omicron variant has stronger transmissibility, indicating that rapid epidemiological investigation and strict management are needed.

Robotic versus laparoscopic liver resection in posterosuperior region: a retrospective study of consecutive cases

BACKGROUND

Minimally invasive liver resection of the posterosuperior region is considered a challenging procedure due to poor exposure and difficult bleeding control. A robotic approach is supposed to be advantageous in posterosuperior segmentectomy. Its benefits over laparoscopic liver resection (LLR) remain undetermined. This study compared robotic liver resection (RLR) and LLR in the posterosuperior region performed by a single surgeon.

MATERIALS AND METHODS

We retrospectively analyzed consecutive RLR and LLR performed by a single surgeon between December 2020 and March 2022. Patient characteristics and perioperative variables were compared. A 1:1 propensity score matched (PSM) analysis was performed between both groups.

RESULTS

The analysis included 48 RLR and 57 LLR procedures in the posterosuperior region. After PSM analysis, 41 cases of both groups were retained. In pre-PSM cohort, the operative time in the RLR group was significantly shorter than in the LLR group (160 vs. 208 min, P = 0.001), especially in radical resection of malignant tumors (176 vs. 231 min, P = 0.004). The total Pringle maneuver duration was also markedly shorter (40 vs. 51 min, P = 0.047), and the estimated blood loss in the RLR group was lower (92 vs. 150 mL, P = 0.005). The postoperative hospital stay (POHS) in the RLR group was significantly shorter (5.4 vs. 7.5 days, P = 0.048). In PSM cohort, operative time in the RLR group was also significantly shorter (163 vs. 193 min, P = 0.036), and the estimated blood loss was lower (92 vs. 144 mL, P = 0.024). However, the total Pringle maneuver duration and POHS showed no significant difference. The complications were similar between two groups in both pre-PSM and PSM cohorts.

CONCLUSION

RLR in the posterosuperior region was as safe and feasible as LLR. RLR was associated with reduced operative time and blood loss than LLR.

Shear stress leads to the dysfunction of endothelial cells through the Cav-1-mediated KLF2/eNOS/ERK signaling pathway under physiological conditions

To investigate the mechanism of shear stress on endothelial cell dysfunction for providing a theoretical basis for the reduction of arteriovenous fistula dysfunction. The in vitro parallel plate flow chamber was used to form different forces and shear stress to mimic the hemodynamic changes in human umbilical vein endothelial cells, and the expression and distribution of krüppel-like factor 2 (KLF2), caveolin-1 (Cav-1), p-extracellular regulated protein kinase (p-ERK), and endothelial nitric oxide synthase (eNOS) were detected by immunofluorescence and real-time quantitative polymerase chain reaction. With the prolongation of the shear stress action time, the expression of KLF2 and eNOS increased gradually, while the expression of Cav-1 and p-ERK decreased gradually. In addition, after cells were exposed to oscillatory shear stress (OSS) and low shear stress, the expression of KLF2, Cav-1, and eNOS decreased and the expression of p-ERK increased. The expression of KLF2 increased gradually with the prolongation of action time, but it was still obviously lower than that of high shear stress. Following the block of Cav-1 expression by methyl β-cyclodextrin, eNOS expression decreased, and KLF2 and p-ERK expression increased. OSS may lead to endothelial cell dysfunction by Cav-1-mediated KLF2/eNOS/ERK signaling pathway.

[Investigation for pathological interpretation criteria and its prognostic value for P53 expression in Chinese diffuse large B-cell lymphoma]

Objective: To explore the feasibility of predicting TP53 mutation risk by immunohistochemical staining (IHC) pattern of P53 in Chinese diffuse large B-cell lymphoma (DLBCL) and its correlation with a prognostic difference. Methods: Between January 2021 and December 2021, 51 DLBCL cases at Beijing Boren Hospital were gathered. These cases had both IHC and next-generation sequencing (NGS) results. IHC classified the P53 protein expression pattern into a loss (<1% ) , diffuse (>80% ) , and heterogeneous (1% -80% ) . The sensitivity and specificity of the predicting TP53 mutation by IHC were assessed by comparing the results of the NGS, and the TP53 high mutation risk group included both loss and diffuse expression of P53. From June 2016 to September 2019, Peking University Cancer Hospital collected 131 DLBCL cases with thorough clinicopathological and follow-up data. From their tumor blocks, tissue microarray blocks were made for IHC evaluation of P53 expression pattern, and prognosis effect of P53 studies. Results: Among 51 cases with both IHC and NGS results, 23 cases were classified as TP53 high mutation risk (7 cases loss and 16 cases diffuse) , 22/23 cases were proved with mutated TP53 by NGS. Only 1 of the 28 cases classified as TP53 low mutation risk was proved with mutated TP53 by NGS. IHC had a sensitivity and specificity of 95.7% and 96.4% for predicting TP53 mutation. NGS identified a total of 26 TP53 mutations with a mutation frequency of 61.57% (13.41% -86.25% ) . In the diffuse group, 16 missense mutations and 2 splice mutations were detected; 6 truncating mutations and 1 splice mutation were detected in the loss group; 1 truncating mutation was detected in the heterogeneous group. Multivariate analysis demonstrated that TP53 cases with high mutation risk have impartial adverse significance for the 131 patients included in survival analysis (HR=2.612, 95% CI 1.145-5.956, P=0.022) . Conclusion: IHC of P53 exhibiting loss (<1% ) or diffuse (>80% ) pattern indicated TP53 high mutation risk, IHC can predict TP53 mutation with high specificity and sensitivity. TP53 high mutation risk is an independent predictor for adverse survival.

Correlation analysis between risk factors, BMD and serum osteocalcin, CatheK, PINP, β-crosslaps, TRAP, lipid metabolism and BMI in 128 patients with postmenopausal osteoporotic fractures

OBJECTIVE

Our aim is to investigate the correlation between risk factors of postmenopausal osteoporotic fracture, BMD and Bone turnover markers, lipid metabolism and BMI.

SUBJECTS AND METHODS

The Cox proportional hazard model was used to conduct univariate and multivariate analysis to screen the risk factors related to postmenopausal osteoporotic fractures. Blood samples were collected to detect biochemical markers of bone turnover, blood lipids content, and then measure the BMI of the survey subjects. BMD was measured and its correlation with biochemical markers of bone turnover, lipid metabolism and BMI was analyzed.

RESULTS

Cox univariate analysis indicated that average age, menopause, years since menopause, number of deliveries, and limb spasm are associated covariates of postmenopausal osteoporotic fractures. Where, BMD severity, history of hysterectomy or ovariectomy, and years since menopause are significant covariates for the incidence of postmenopausal osteoporotic fractures. The correlation study with lipid metabolism found that the smaller the BMI value, the greater the BMD loss; the smaller the TG value, the greater the BMD loss, exhibiting a downward trend. No difference was observed between HDL-C and LDL-C content, and the difference was not statistically significant (p>0.05). Femoral neck BMD was negatively correlated with CatheK, serum osteocalcin, PINP, β-crosslaps and TRAP, and lumbar spine BMD was also negatively correlated with CatheK, serum osteocalcin, PINP, β-crosslaps and TRAP.

CONCLUSIONS

Biochemical markers of bone turnover are highly expressed in postmenopausal women and increase with the decrease of bone density, which can be used as markers for disease prediction. Combined with BMI, triglyceride and other related indicators, and closely related factors such as the patient's age, the number of deliveries, it is possible to predict the incidence of PMOP fractures early.

Pathology of catheter-related complications: what we need to know and what should be discovered

Despite the considerable efforts made to increase the prevalence of autogenous fistula in patients on hemodialysis, tunneled cuffed catheters are still an important access modality and used in a high percentage of the hemodialysis population. However, because of the conundrum posed by tunneled cuffed catheters, patients can develop a multitude of complications, including thrombosis, infections, formation of a fibrin sheath, and central vein stenosis, resulting in increased morbidity and mortality as well as placing a heavy burden on the healthcare system. However, with an increasing number of studies now focusing on how to manage these catheter-related complications, there has been less translational research on the pathology of these complications. This review of the most recent literature provides an update on the pathological aspects of catheter-related complications, highlighting what we need to know and what is yet to be discovered. The future research strategies and innovations needed to prevent these complications are also addressed.

[Survey on infection source of a cold-chain product associated COVID-19 epidemic caused by 2019-nCoV Delta variant in Beijing]

Objective: To investigate the source and the transmission chain of a cold-chain product associated COVID-19 epidemic caused by 2019-nCoV Delta variant in Beijing. Methods: Epidemiological investigation were used to verify the exposure points of the cases. Close contacts were traced from the exposure points, and human and environmental samples were collected for nucleic acid tests. Positive samples were analyzed by gene sequencing. Results: A total of 112 cases of COVID-19 were reported in the epidemic from January 18 to February 6, 2022 in Beijing. Except for 1 case was uncertain, there were epidemiological links among 111 cases. The source of infection was the packages of imported cold-chain products from Southeast Asia, which were harvested and stored in a local cold-storage in January 2021, and packaged and sent to the cold-storage A in A district in June 2021, and then sold in batches in cold-storage B in B district from January 2022. The first case was infected in the handling of positive frozen products, and then 77 cases occurred due to working, eating and living together with the index case in the cold-storage B, cold-storage C and restaurant D. Besides the cold-storage B, C and the restaurant D, there were 16 sub-transmission chains, resulting in additional 35 cases. Conclusion: The epidemic indicated that the risk of 2019-nCoV infection from imported cold-chain products contaminated by package and highlighted the importance to strengthen the management of cold-chain industry in future.

Prognostic Value of Systemic Immune-Inflammation Index among Critically Ill Patients with Acute Kidney Injury: A Retrospective Cohort Study

Inflammation plays a significant role in the occurrence and development of acute kidney injury (AKI). Evidence regarding the prognostic effect of the systemic immune-inflammation index (SII) in critically ill patients with AKI is scarce. The aim of this study was to assess the association between SII and all-cause mortality in these patients. Detailed clinical data were extracted from the Medical Information Mart for Intensive Care Database (MIMIC)-IV. The primary outcome was set as the in-hospital mortality. A total of 10,764 AKI patients were enrolled in this study. The restricted cubic splines analyses showed a J-shaped curve between SII and the risk of in-hospital and ICU mortality. After adjusting for relevant confounders, multivariate Cox regression analysis showed that both lower and higher SII levels were associated with an elevated risk of in-hospital all-cause mortality. A similar trend was observed for ICU mortality. In summary, we found that the SII was associated in a J-shaped pattern with all-cause mortality among critically ill patients with AKI. SII appears to be have potential applications in the clinical setting as a novel and easily accessible biomarker for predicting the prognosis of AKI patients.

[Progress in epidemiological research of norovirus infection]

With characteristics of high infectivity, diverse transmission routes and high variation, norovirus is the main pathogen of sporadic cases and outbreaks of acute gastroenteritis, resulting in a serious disease burden. This paper summarizes the latest progress in epidemiological research of norovirus infection from aspects of disease burden caused by acute gastroenteritis, virus variation and predominant strains, prevention and control measures, and immunization and vaccine development.

[Benefits and risks of prolonged dual antiplatelet therapy after percutaneous coronary intervention with drug-eluting stent in patients with stable coronary artery disease and diabetes]

Objective: To compare the efficacy and safety of prolonged dual antiplatelet therapy (DAPT>1 year) in patients with stable coronary artery disease (CAD) and diabetes who were event-free at 1 year after percutaneous coronary intervention (PCI) with drug-eluting stent (DES) in a large and contemporary PCI registry. Methods: A total of 1 661 eligible patients were selected from the Fuwai PCI Registry, of which 1 193 received DAPT>1 year and 468 received DAPT ≤1 year. The primary endpoint was major adverse cardiac and cerebrovascular event (MACCE) and Bleeding Academic Research Consortium (BARC) type 2, 3 or 5 bleeding, MACCE was defined as a composite of all-cause death, myocardial infarction or stroke. Multivariate Cox regression analysis and inverse probability of treatment weighting (IPTW) Cox regression analysis were performed. Results: After a median follow-up of 2.5 years, patients who received DAPT>1 year were associated with lower risks of MACCE (1.4% vs. 3.2%; hazard ratio (HR) 0.412, 95% confidence interval (CI) 0.205-0.827) compared with DAPT ≤1 year, which was primarily caused by the lower all-cause mortality (0.1% vs. 2.6%; HR 0.031, 95%CI 0.004-0.236). Risks of cardiac death (0.1% vs. 1.5%; HR 0.051, 95%CI 0.006-0.416) and definite/probable ST (0.3% vs. 1.1%; HR 0.218, 95%CI 0.052-0.917) were also lower in patients received DAPT>1 year than those received DAPT ≤ 1 year. No difference was found between the two groups in terms of BARC type 2, 3, or 5 bleeding (5.3% vs. 4.1%; HR 1.088, 95%CI 0.650-1.821). Conclusions: In patients with stable CAD and diabetes who were event-free at 1 year after PCI with DES, prolonged DAPT (>1 year) provides a substantial reduction in ischemic cardiovascular events, including MACCE, all-cause mortality, cardiac mortality, and definite/probable ST, without increasing the clinically relevant bleeding risk compared with ≤ 1-year DAPT. Further well-designed, large-scale randomized trials are needed to verify the beneficial effect of prolonged DAPT in this population.

[Etiological and epidemiological characteristics of Vibrio cholerae in Beijing, 2015-2021]

Objective: To analyze the etiological and epidemiological characteristics of Vibrio cholerae in Beijing during 2015-2021 and provide evidence for the prevention and control of cholera. Methods: The V. cholerae strains isolated in Beijing during 2015-2021 were analyzed by serotyping and virulence genes detection. Pulsed field gel electrophoresis (PFGE) was performed for the molecular typing of the strains. Based on the collected epidemiological and clinical data of cholera cases,the epidemiological characteristics of cholera were analyzed by descriptive epidemiology method. Results: A total of 76 Vibrio cholerae O1 strains were isolated in Beijing during 2015-2021, including 61 strains from human, 10 strains from environment and 5 strains from seafood. The 76 strains consisted of 68 Ogawa strains and 8 Inaba strains. Six Ogawa strains isolated from sporadic cases carried ctxAB. After NotⅠ digestion, 76 strains were divided into 33 PFGE patterns. From 2015 to 2021, a total of 38 cholera epidemics were reported in Beijing, most of them were sporadic ones, accounting for 92.11% (35/38). A total of 45 cases were reported, and the cases occurred during June-September accounted for 97.78% (44/45). Cholera cases occurred in 9 districts of Beijing, and the cases reported in Chaoyang district accounted for 42.22% (19/45) and in Changping district accounted for 31.11% (14/45). The age of the cholera cases ranged from 19 to 63 years. Except for one case with unknown clinical symptoms, 44 cases had diarrhea symptoms with 84.09% (37/44) of the cases reporting diarrhea (3-9 times/day), followed by yellow watery stool (95.45%, 42/44), abdominal pain (68.18%, 30/44), nausea and vomiting (40.91%, 18/44) and fever (36.36%, 16/44). Conclusion: Vibrio cholerae strains isolated in Beijing during 2015-2021 were mainly O1 serotype Ogawa,most of which were non-toxigenic. The PFGE of the strains varied. Cholera epidemics occurred in 9 districts of Beijing, but most were sporadic ones with incidence peak during June-September.

[Epidemiological characteristics of imported COVID-19 cases in Beijing]

Objective: To analyze the epidemiological characteristics of imported COVID-19 cases and the effect of vaccination on virus load and disease severity of the cases in Beijing. Methods: The data of the imported COVID-19 cases in Beijing were collected from the National Notifiable Infectious Disease Reporting System of China Information for Disease Control and Prevention and Epidemiology investigation. The data were processed and analyzed by Excel 2010 and SPSS 22.0. Results: From June 1 to September 30, 2021, a total of 171 imported COVID-19 cases were reported in Beijing, of which 66.67% (114/171) were asymptomatic. The cases were mainly from the Philippines, the United Arab Emirates, the United Kingdom and the Russian Federation, accounting for 67.84% (116/171). The male to female ratio of the cases was 2∶1 (114∶57). The median age M (Q₁, Q₃) of the cases was 28 (23, 36) years. The cases of Chinese accounted for 80.12% (137/171). The sequencing of the whole genome of the virus in 47 imported COVID-19 cases showed that the proportion of Delta variant was 76.60% (36/47). The COVID-19 vaccination coverage rate in the cases was 60.82% (104/171), but the full vaccination coverage rate was 53.80% (92/171). In the imported COVID-19 cases, 13.53% (23/170) were screened to be SARS-CoV-2 nucleic acid positive on the day when they arrived in Beijing, and all the cases were positive for 2019-nCoV nucleic acid within 28 days. The severity of the disease was higher in the unvaccinated group than in the partially vaccinated group and fully vaccinated group (P<0.001). In the unvaccinated group, there were 1 severe case and 1 critical case. The median Ct values M (Q₁, Q₃) of N gene and ORFlab gene in unvaccinated group were 32.51 (23.23, 36.06) and 32.78 (24.00, 36.38), respectively. There was no significant difference in the median of double-gene Ct value between the partially vaccinated group and the fully vaccinated group. Conclusions: During the study period, most of the imported COVID-19 cases in Beijing were asymptomatic. No matter vaccinated or not, the viral loads in the COVID-19 cases were similar, but the vaccination could reduce the severity of the disease.

Highly stretchable, self-healing and conductive silk fibroin-based double network gels via a sonication-induced and self-emulsifying green procedure

Regenerated silk fibroin (RSF)-based hydrogels are promising biomedical materials due to their biocompatibility and biodegradability. However, the weak mechanical properties and lack of functionality limit their practical applications. Here, we developed a tough and conductive RSF-based double network (DN) gel, consisting of a sonication-induced β-sheet physically crosslinked RSF/S gel as the first network and a hydrophobically associated polyacrylamide/stearyl methacrylate (PAAm/C18) gel as the second network. In particular, the cross-linking points of the second network were micelles formed by emulsifying the hydrophobic monomer (C18M) with a natural SF- capryl glucoside co-surfactant. The reversible dynamic bonds in the DN provided good self-healing ability and an effective dissipative energy mechanism for the DN hydrogel, while the addition of calcium ions improved the self-healing ability and electrical conductivity of the hydrogel. Under optimal conditions, the RSF/S-PAAm/C18 DN gels exhibited large extensibility (1400%), high tensile strength (0.3 MPa), satisfactory self-healing capability (90%) and electrical conductivity (0.12 S·m-1). The full physically interacted DN hydrogels are expected to be applied in various fields such as tissue engineering, biosensors and artificial electronic skin.

Simple Preparation of a Waterborne Polyurethane Crosslinked Hydrogel Adhesive With Satisfactory Mechanical Properties and Adhesion Properties

Waterborne polyurethane has been proven to be an ideal additive for the preparation of hydrogels with excellent mechanical properties. This work reports that a satisfactory adhesion of acrylamide hydrogels can be obtained by introducing a large amount of waterborne polyurethane into system. A series of polyurethane hydrogels was prepared by using one-pot method with acrylamide monomer and 2-hydroxymethyl methacrylate end-modified waterborne polyurethane emulsion. The hydrogels exhibit good strength (greater than 30 KPa), wide range of adjustable strain (200%–800%), and excellent compression fatigue resistance. The performance improvement is attributed to the fact that the polyurethane emulsion containing double bonds provides chemical crosslinking and forms polyurethane microregions due to hydrophilic and hydrophobic interactions. The hydrogel shows extensive and repeatable adhesion on diverse substrates. This simple preparation method through polyurethane crosslinked hydrogels is expected to become a low-cost and efficient preparation strategy for hydrogel adhesives.

[Epidemiological characteristics of hand, foot and mouth disease among people aged 6 and over in Beijing, 2011-2020]

Objective: To analyze the epidemiological characteristics of hand, foot and mouth disease (HFMD) among people ≥6 years old in Beijing from 2011 to 2020. Methods: The incidence data of HFMD cases from 2011 to 2020 were collected from the National Notifiable Infectious Disease Reporting System of China Information for Disease Control and Prevention and the etiological surveillance of HFMD in 29 sentinel hospitals from 16 districts of Beijing. Descriptive epidemiological methods were used to analyze the distributions, pathogen constituents, and changes of HFMD cases in Beijing people ≥6 years old. Results: From 2011 to 2020, a total of 38 183 cases of HFMD were reported among people ≥6 years old in Beijing, of which 46 (0.12%) cases were severe. The average annual reported incidence was 19.04/100 000. The ratio of males to females were 1.37∶1(22 064∶16 119). The proportion of HFMD in people ≥6 years old increased from 7.56%(2 606/34 488) in 2011 to 24.54% (546/2 225) in 2020. The average incidence of HFMD was higher in Shunyi district, Yanqing district, and Tongzhou district than in other districts in Beijing. The positive rate of enterovirus in sentinel surveillance was 66.78% (1 976/2 959), the proportion of enterovirus group A 71 (EV-A71) was 45.29% (101/223) in 2014, no EV-A71 positive was detected in 2020, and the proportion of Coxsackievirus A 6 (CV-A6) increased from 15.11% (34/225) in 2016 to 81.08% (60/74) in 2020. Conclusions: From 2011 to 2020, the proportion of cases with HFMD in people ≥6 years old in Beijing increased yearly, and the proportion of EV-A71 positive patients decreased basically. Since 2016, CV-A6 has gradually become the dominant pathogen. More attention should be paid to the epidemic situation and dynamic pathogen changes of hand foot mouth disease in people ≥6 years old.

Leptin Aggravates Periodontitis by Promoting M1 Polarization via NLRP3

Periodontitis is characterized by periodontal pocket formation, loss of attachment, and alveolar bone resorption. Both innate and adaptive immunity are involved in the pathogenesis of this oral chronic inflammatory disease. Accumulating evidence indicates a critical role of leptin in periodontal diseases. However, the mechanism by which leptin promotes periodontitis pathogenesis remains unclear. In the present study, we observed an elevated expression of leptin in the serum of periodontitis mice compared to that in healthy controls. There was a higher extent of M1 phenotype macrophage infiltration in mice periodontitis samples than in healthy controls. A positive correlation was observed between the serum leptin levels and M1 macrophages. Treatment with leptin increased M1 macrophage polarization and decreased M2 macrophage polarization in RAW 264.7 cells. Moreover, leptin facilitated lipopolysaccharide (LPS)-induced M1 phenotype macrophage polarization in RAW 264.7 cells. In bone marrow-derived macrophages (BMDMs) generated from leptin-deficient obese (ob/ob) mice, M1 macrophage polarization was significantly attenuated after LPS stimulation compared to the healthy controls. With regards to the molecular mechanism, we found that leptin activated the NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome and promoted M1 polarization via the NLRP3 inflammasome in vitro. In BMDMs generated from Nlrp3^-/- mice, M1 macrophage polarization was significantly attenuated after synchronous stimulation with leptin and LPS compared with BMDMs produced by healthy controls. The NLRP3 inhibitor MCC950 also prevented leptin-mediated M1 macrophage polarization in RAW 264.7 cells. Nlrp3^-/- periodontitis models indicated that leptin aggravates the periodontal response to the ligature by promoting M1 macrophage polarization via the NLRP3 inflammasome. Taken together, we show that leptin promotes the progression of periodontitis via proinflammatory M1 macrophage skewing, and targeting leptin/NLRP3 signaling may be a feasible approach for treating periodontitis.

Three-dimensional Quantification of Enamel Preservation in Tooth Preparation for Porcelain Laminate Veneers: A Fully Digital Workflow In Vitro Study

OBJECTIVE

This in vitro study aimed to evaluate the preservation of enamel after tooth preparation for porcelain laminate veneers (PLVs) at different preparation depths based on a fully digital workflow.

METHODS AND MATERIALS

Sixty extracted human maxillary anterior teeth, including 20 maxillary central incisors (MCIs), 20 maxillary lateral incisors (MLIs), and 20 maxillary canines (MCs) underwent microcomputed tomography (CT) scanning, and were reconstructed as three-dimensional (3D) enamel and dentin models. Subsequently, the three-dimensional (3D) enamel models were imported into Materialise, where each enamel model underwent seven types of virtual preparation for PLVs at preparation depths at 0.1-mm increments from 0.1-0.3-0.5 mm (D1) to 0.7-0.9-1.1 mm (D7). The enamel surface was depicted by merging the virtual preparation and, respective, dentin models. The enamel area and prepared surface were measured to calculate the percentage of enamel (R%). The data were statistically analyzed using one-way analysis of variance (ANOVA) (α=0.05).

RESULTS

The group-wise mean (standard deviation) R values for the MCIs were as follows: D1-D3: 100.00 (0) each, and D4-D7: 74.70 (2.45), 51.40 (5.12), 24.40 (3.06), and 0.00 (0), respectively. The group-wise mean R values for the MLIs were 100.00 (0), 73.70 (3.40), 53.50 (3.44), 25.20 (3.79), and 0.90 (0.99) for the D1-D5 groups, respectively; and 0.00 (0) each for the D6-D7 groups. The group-wise mean (standard deviations) R values for the MCs were as follows: D1-D3: 100.00 (0) each, and D4-D7: 99.00 (1.34), 77.10 (3.28), 74.20 (3.61), and 52.20 (4.09), respectively. The one-way ANOVA revealed significant differences between the seven groups in the MCIs, MLIs, and MCs (p<0.05).

CONCLUSIONS

Our results recommended preparation depths of up to 0.3-0.5-0.7 mm (MCIs), 0.1-0.3-0.5 mm (MLIs), and 0.4-0.6-0.8 mm (MCs) to facilitate complete intraenamel preparation. Moreover, 50% enamel was preserved at preparation depths of 0.5-0.7-0.9 mm (MCIs), 0.3-0.5-0.7 mm (MLIs), and 0.7-0.9-1.1 mm (MCs).

Preparation and Finite Element Analysis of Fly Ash/HDPE Composites for Large Diameter Bellows

In recent years, buried bellows have often had safety accidents such as pipeline bursts and ground subsidence due to the lack of adequate mechanical properties and other quality problems. In order to improve the mechanical properties of bellows, fly ash (FA) was used as a reinforced filler in high density polyethylene (HDPE) to develop composites. The FA was surface treated with a silane coupling agent and HDPE-g-maleic anhydride was used as compatibilizer. Dumbbell-shaped samples were prepared via extrusion blending and injection molding. The cross-section morphology, thermal stability and mechanical properties of the composites were studied. It was observed that when 10% modified FA and 5% compatibilizer were added to HDPE, the tensile yield strength and tensile breaking strength of the composites were nearly 30.2% and 40.4% higher than those of pure HDPE, respectively, and the Young’s modulus could reach 1451.07 MPa. In addition, the ring stiffness of the bellows was analyzed using finite element analysis. Compared with a same-diameter bellows fabricated from common commercially available materials, the ring stiffness increased by nearly 23%. The preparation method of FA/HDPE is simple, efficient, and low-cost. It is of great significance for the popularization of high-performance bellows and the high value-added utilization of FA.

[Effect of half-dose fluorescein sodium contrast agent on liver and kidney functions in patients with mild to moderate chronic kidney disease: a retrospective cohort study]

OBJECTIVE

To observe the effect of half-dose fluorescein sodium (FINa) contrast agent on liver and kidney functions in patients with mild to moderate (stage 1 to 3) chronic kidney disease (CKD) and the incidence of contrast-induced nephropathy (CIN).

METHODS

Seventy-seven patients (including 50 male and 27 female patients with an mean age of 53.5±9.6 years) with CKD with normal renal function or mild to moderate abnormalities underwent fundus fluorescein angiography (FFG) examination with half-dose FINa. Liver function, blood creatinine (Scr), blood urea nitrogen (BUN), urine β2 microglobulin (β2-MG), and glomerular filtration rate (eGFR) of the patients were measured within 3 days before intravenous injection of the contrast agent and at 1, 3, 7, and 30±1 days after the operation to analyze the effect of the contrast agent on renal function.

RESULTS

Among the 77 patients, CIN occurred only in one case with an incidence rate of 1.30%. BUN, urine β2- MG, or rapid microalbumin/creatinine did not vary significantly after FFA in these patients. Scr levels showed no significant increments at 1 day and 7 days after FFA, but increased significantly at 3 days (24.6±2.3; P < 0.01) and 30 days (16.0±21.7; P < 0.05). Urine NAG enzymes and urinary osmolality were significantly reduced at 1, 3, 7, and 30 days after FFA (P < 0.01). The eGFR decreased significantly to 10.23±0.62 at 3 days after FAG and became normal at 7 days. Urine albumin level decreased significantly at 1, 3, 7, and 30 days after FFA (P < 0.01). Blood β2-MGFAG level increased significantly at 3 days after FFA (0.314± 0.121; P < 0.01), but decreased to 0.134±0.143 at 7 days (P < 0.05). The level transaminase decreased significantly at 3 and 7 days after FFA (P < 0.01).

CONCLUSION

Half-dose of FINa has no significant effect on liver function and has only minimal effect on kidney function in patients with mild to moderate CKD, and FFA with half-dose FINa can therefore be safely performed in these patients.

Label-free Fluorescence Turn on Trypsin Assay Based on Gemini Surfactant/heparin/Nile Red Supramolecular Assembly

In this research, we designed a label-free fluorometric turn-on assay for trypsin and inhibitor screening, based on a spherical cationic gemini surfactant ethylene-bis (dodecyl dimethyl ammonium bromide) (EDAB)/heparin/Nile red (NR) supramolecular assembly system. The introduction of gemini surfactant EDAB as template greatly enhanced its salt resistance and resulted in the supramolecular assemblies with diameters ranging from 20 to 100 nm. The fluorometric assay for trypsin was performed by firstly disassembling with protamine (a heparin-binding protein) and then re-assembling through hydrolysis of protamine. The disassembly and reassembly of the system resulted in a turn-off first and then a turn-on behavior of the corresponding fluorescence. The overall processes were characterized by fluorescence spectra, TEM measurements and zeta potential tests. The detection level of this assembly system for trypsin was as low as 4.2 ng mL^-1. Also, the EDAB/heparin/NR assembly could be used to screen the trypsin inhibitors. The assembly system was easily-fabricated and cost-effective, but also exhibited good salt tolerance in NaCl solution at the concentration of 0-500 mM. At last, the supramolecular assembly was successfully applied to detect trypsin in human urine, demonstrating its great potential on clinical diagnosis applications.

[Analysis on epidemiological characteristics of multidrug-resistant Salmonella Kentucky in Beijing, 2010-2020]

Objective: To investigate the epidemiological, drug resistance and molecular characteristics of Salmonella (S.) Kentucky strains isolated from diarrheal patients in Beijing. Methods: The drug susceptibility of 22 S. Kentucky strains isolated in Beijing during 2010-2020 was tested by using the micro broth dilution method. The multilocus sequence typing (MLST), drug resistance genes and Salmonella genomic island (SGI) identifications of the strains were performed by whole-genome sequencing (WGS).The pulsed field gel electrophoresis (PFGE) was performed to analyze the molecular epidemiological characteristics of the isolates. Results: The 22 strains were highly resistant to 8-22 kinds of antibiotics, especially to ciprofloxacin, cephalosporins and azithromycin, etc., showing a super high level of multidrug resistance and 21 strains were positive for extended-spetrum beta-lactamase (ESBL). The WGS analysis revealed that all the isolates belonged to ST198, carrying SGI1-K. The drug resistance genes tetA, sul1 and qacE were identified in all strains and Quinolone resistance-determining regions (QRDRs) showed 2 mutations in gyrA (S83F, D87 N) and 3 mutations in the parC gene (T57S, S80I, T255S). The resistance genes associated with β-lactam antibiotics (blaCTX-M-55, blaCTX-M-14b, blaTEM-141, blaTEM-206, blaTEM-209, blaTEM-214, blaTEM-1B), resistance genes associated with aminoglycosides [aac(3)-Id, aac(3)-IId, aac(6')-Iaa, aadA7, aadA17, aph(3')-Ia, aph(3'')-Ib, aph(6)-Id,rmtB] as well as floR, dfrA14, mphA and qnrS1 had significant differences in the strains of different years, which were highly consistent with the drug-resistant phenotype. Furthermore, phylogenetic analysis showed that the similarity of the 22 strains was more than 85%, and the strains were highly homologous to CIP-resistant ST198-X1 circulating in the world. In the process of spread, the drug resistance and PFGE spectrums had changed, two clusters had formed. Conclusions: The S. Kentucky strains isolated in Beijing shared high homology with the multidrug-resistant strain ST198-X1-SGI-1K isolated in the world, which has maintained a low level of spread since 2016, causing sporadic infections and clusters of diarrhea, and has serious resistances to fluoroquinolones, ESBLs and azithromycin. The surveillance for multidrug-resistant S. Kentucky should be strengthened.

Expression of miR-182 in patients with fracture of tibial plateau and its regulative effects on the fracture healing

OBJECTIVE

To investigate the expression of miR-182 in patients with fracture of tibial plateau (FTP) and its effects on osteoblasts and fracture healing.

PATIENTS AND METHODS

The patients with fracture of tibial plateau treated in our hospital and healthy subjects who received physical examination from January 2017 to January 2018 were collected. The expression of miR-182 in the serum was detected. The osteoblasts from SD rats were cultured and transfected with miR-182, anti-miR-182, miR-NC or anti-miR-NC using transfection reagent LipofectamineTM 2000. The proliferation, alkaline phosphatase (ALP) activity, calcification and osteogenic gene expression of osteoblasts were detected. The rat models with fracture of tibial plateau were divided into control group, fracture group, fracture+miR-182 group, and fracture+anti-miR-182 group. The levels of vascular endothelial growth factor (VEGF), epidermal growth factor (EGF) and transforming growth factor β (TGFβ) in serum were detected by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Compared with the controls, the expression of miR-182 in serum was significantly elevated in patients with fracture of tibial plateau. Overexpression of miR-182 inhibited the proliferation of osteoblasts, while the knockdown of miR-182 increased the proliferation. MiR-182 could decrease the ALP activity of osteoblasts, while anti-miR-182 increased the ALP activity. Osteoblast calcification ability was significantly decreased by overexpression of miR-182. Knockdown of miR-182 increased the calcification ability of osteoblasts and the expression of osteogenic genes. MiR-182 could inhibit the expression of osteogenic genes. The levels of VEGF, EGF and TGFβ in the fracture group were higher than those in the control group, while the levels in the fracture+miR-182 group were higher than those in the fracture group. The levels of VEGF, EGF and TGFβ in the anti-miR-182 group were lower than those in the fracture group.

CONCLUSIONS

MiR-182 is elevated in patients with fracture of tibial plateau, which can inhibit the proliferation and differentiation of osteoblasts and affect the fracture healing. The knockdown of miR-182 might be a new method for treating fracture healing.

[A Meta-analysis of the predictive effect of neutrophil-lymphocyte ratio on acute kidney injury]

OBJECTIVE

To systematically evaluate the predictive value of neutrophil-lymphocyte ratio (NLR) in acute kidney injury (AKI).

METHODS

All studies about the predictive effect of NLR on AKI were searched in the National Medical Library of the United States PubMed Database, the Embase database in the Netherlands, the Chinese Biology Medicine disc (CBMdisc) and the Chinese Evidence Based Medicine Cochrane Centre Database (CEBM/CCD). The data updated by October 2020, and regardless of language, region or whether blind method was used. Two authors independently extracted data and evaluated the quality of the studies. Data extracted from the studies were analyzed with RevMan 5.3 to assess the predictive value of NLR on AKI. A subgroup Meta-analysis was conducted to assess the predictive value of NLR on AKI according to different countries, different disease types (cardiovascular surgery, infectious diseases, other diseases including burns, cirrhosis, and emergency), and different sample sizes (≤ 300 cases and > 300 cases). The publication bias of included studies about the predictive effect of NLR on AKI were assessed by funnel plots.

RESULTS

A total of 11 studies were included in this Meta-analysis, including 4 997 patients, 1 308 patients in AKI group, and 3 689 patients in non-AKI group. The Meta-analysis results showed that: increased NLR had predictive value for the occurrence of AKI [mean difference (MD) = 2.73, 95% confidence interval (95%CI) was 1.78-3.68, P < 0.000 01]. Subgroup analysis showed that increased NLR had predictive value for the occurrence of AKI in patients from Southeast Asia (MD = 4.04, 95%CI was 1.09-6.99, P = 0.007) and Eurasia (MD = 2.51, 95%CI was 1.12-3.90, P = 0.000 4). Increased NLR had predictive value for the occurrence of AKI in patients undergoing cardiovascular surgery (MD = 0.77, 95%CI was 0.34-1.20, P = 0.000 4), infectious diseases (MD = 4.74, 95%CI was 1.51-7.96, P = 0.004) and other diseases (MD = 8.53, 95%CI was 6.26-10.80, P < 0.000 01). Increased NLR had predictive value for the occurrence of AKI in studies with a sample size of ≤ 300 cases (MD = 6.02, 95%CI was 4.90-7.14, P < 0.000 01) and > 300 cases (MD = 1.32, 95%CI was 0.61-2.03, P = 0.000 3). There was no significant publication bias in the included studies assessed by funnel plots.

CONCLUSIONS

NLR is an important predictive tool for AKI.

[Epidemiological characteristics of COVID-19 cases in outbreak in Xinfadi market in Beijing]

Objective: To understand the epidemiological characteristics of COVID-19 cases, including asymptomatic cases and symptomatic cases, in the outbreak in Xinfadi market in Beijing. Methods: Data and epidemiological survey reports of COVID-19 cases in Xinfadi market in Beijing were extracted from China's Infectious Disease Information System. Epidemiological characteristics of symptomatic cases and asymptomatic cases were analyzed and compared by using software SPSS 19.0. Results: From June 11 to July 10, 2020, a total of 368 laboratory-confirmed COVID-19 cases reported in the outbreak in Xinfadi market, in which, 335 (91.03%) were symptomatic and 33 (8.97%) were asymptomatic. The cases were distributed in 11 districts, and most cases (252/368, 68.48%) were reported in Fengtai district. The incidence curve of the cases showed a typical outbreak pattern, the case number peaked on 13 June. The median age of the cases were 43 years (Q_R: 31-51). The asymptomatic cases (M=32, Q_R: 29-46) were younger than the symptomatic cases (M=43, Q_R: 31-52), the difference was significant (Z=2.416, P=0.016). The ratio of male to female was 1.26∶1. Most cases (236/368, 64.13%) were engaged in catering service and public place service. About 73.91% of the cases (272/368) had direct exposures in Xinfadi market. About 54.08%(199/368) of cases were detected through nucleic acid testing and screening. Mild and moderate cases accounted for 99.10% (332/335) of the total cases, and no death occurred. Conclusion: The COVID-19 cases in the outbreak in Xinfadi market were mainly engaged in catering service and public place service. The asymptomatic cases were younger than the symptomatic cases.

A Facile Strategy for Fabrication Lysozyme-Loaded Mesoporous Silica Nanotubes from Electrospun Silk Fibroin Nanofiber Templates

This paper presents a facile and low-cost strategy for fabrication lysozyme-loaded mesoporous silica nanotubes (MSNTs) by using silk fibroin (SF) nanofiber templates. The “top-down method” was adopted to dissolve degummed silk in CaCl₂/ formic acid (FA) solvent, and the solution containing SF nanofibrils was used for electrospinning to prepare SF nanofiber templates. As SF contains a large number of -OH, -NH₂ and -COOH groups, the silica layer could be easily formed on its surface by the Söber sol-gel method without adding any surfactant or coupling agent. After calcination, the MSNTs were obtained with inner diameters about 200 nm, the wall thickness ranges from 37 ± 2 nm to 66 ± 3 nm and the Brunauer–Emmett–Teller (BET) specific surface area was up to 200.48 m²/g, the pore volume was 1.109 cm³/g. By loading lysozyme, the MSNTs exhibited relatively high drug encapsulation efficiency up to 31.82% and an excellent long-term sustained release in 360 h (15 days). These results suggest that the MSNTs with the hierarchical structure of mesoporous and macroporous will be a promising carrier for applications in biomacromolecular drug delivery systems.

Combination of biomarker with clinical risk factors for prediction of severe acute kidney injury in critically ill patients

Background

Acute kidney injury (AKI) occurs commonly in the intensive care unit (ICU). Insulin-like growth factor-binding protein 7 (IGFBP7) and tissue inhibitor of metalloproteinase-2 (TIMP-2), known as [TIMP-2] x [IGFBP7] (NephroCheck), have been identified as novel biomarkers for the prediction of AKI risk. However, the effective use of disease biomarkers is indispensable from an appropriate clinical context. We conducted a retrospective cohort study to find risk factors and assess the performance of the combination of NephroCheck with risk factors, so as to provide feasible information for AKI prediction.

Methods

All patients who were admitted in the ICU (from June 2016 to July 2017) participated in the study. The primary outcome was the detection of severe AKI within the first 7 days after patients being admitted to the ICU. The predictors were separated into three categories: chronic risk factors, acute risk factors and biochemical indicators.

Results

The study included 577 patients. 96 patients developed to severe AKI (16.6%) within 7 days. In addition to NephroCheck (+) (OR = 2.139, 95% CI (1.260–3.630), P = 0.005), age > 65 years (OR = 1.961, 95% CI (1.153–3.336), P = 0.013), CKD (OR = 2.573, 95% CI (1.319–5.018), P = 0.006) and PCT (+)(OR = 3.223, 95% CI (1.643–6.321), P = 0.001) were also the independent predictors of severe AKI within 7 days. Compared to NephroCheck (+) only (AUC = 0.66, 95% CI:0.60–0.72), the combination of NephroCheck (+) and risk factors (age > 65 years, CKD and PCT positive) (AUC = 0.75, 95% CI:0.70–0.81) led to a significant increase in the area under ROC curve for severe AKI prediction within 7 days.

Conclusions

Although NephroCheck is an effective screening tool for recognizing high-risk patients, we found that combination with biomarker and risk factors (age > 65 years, CKD, procalcitonin positive) for risk assessment of AKI has the greatest significance to patients with uncertain disease trajectories.

Removal of zinc(II) from livestock and poultry sewage by a zinc(II) resistant bacteria

In order to remediate Zn-contaminated livestock and poultry sewage, a zinc-resistant bacterial strain was screened and isolated from the manure of livestock and poultry and identified by molecular biology. The optimal conditions for removing zinc(II) from strain XZN4 were determined by single-factor experiments as follows: within 3 times of repeated use, pH value was 5, initial concentration of zinc(II) was 100 mg/L, the amount of bacteria was 6 g/L, the temperature was 25-30 °C, and the removal equilibrium time was 60 min. Then, through adsorption isotherm model, scanning electron microscope image, energy dispersive spectrum analysis, infrared spectrum analysis and sterilization control experiment, it was found that the removal of zinc(II) by bacteria was single-molecule layer adsorption, which was carried out in coordination with degradation. The influence of different concentrations of copper(II), ammonia nitrogen, phosphorus, and chlortetracycline on the removal of zinc(II) from livestock and poultry sewage by XZN4 strain in the actual application was discussed. The bacteria can reduce the concentration of zinc(II) from the complex livestock and poultry waste water to below the discharge standard, and has a strong environmental tolerance, the highest removal rate reached 88.6% and the highest removal amount reached 10.30 mg/L. The screening and application of XZN4 strain can thus be of great significance for the microbial treatment of zinc(II) in complex livestock and poultry sewage. The results will provide guidance for the microbial remediation of heavy metal pollution.

Association of C1q/TNF-related protein-9 (CTRP9) level with obstructive sleep apnea in patients with coronary artery disease

Background

Obstructive sleep apnea (OSA) is closely related to the incidence and progression of coronary artery disease (CAD), but the mechanisms linking OSA and CAD are unclear. C1q/TNF-related protein-9 (CTRP9) is a novel adipokine that protects the heart against ischemic injury and ameliorates cardiac remodeling.

Purpose

We aimed to ascertain the clinical relevance of CTRP9 with OSA prevalence in patients with CAD.

Methods

From August 2016 to March 2019, consecutive eligible patients with CAD (n=154; angina pectoris, n=88; acute myocardial infarction [AMI], n=66) underwent cardiorespiratory polygraphy during hospitalization. OSA was defined as an apnea-hypopnea index (AHI) ≥15 events h–1. Plasma CTRP9 concentrations were measured by ELISA method.

Results

OSA was present in 89 patients (57.8%). CTRP9 levels were significantly decreased in the OSA group than in the non-OSA group (4.7 [4.1–5.2] ng/mL vs. 4.9 [4.4–6.0] ng/mL, P=0.003). The difference between groups was only observed in patients with AMI (3.0 [2.3–4.9] vs. 4.5 [3.2–7.9], P=0.009), but not in patients with AP (5.0 [4.7–5.3] ng/mL vs. 5.1 [4.7–5.9] ng/mL, P=0.571) (Figure 1). Correlation analysis showed that CTRP9 levels were negatively correlated with AHI (r=−0.238, P=0.003) and oxygen desaturation index (r=−0.234, P=0.004), and positively correlated with left ventricular ejection fraction (r=0.251, P=0.004) in all subjects. Multivariate analysis showed that male gender (OR 3.099, 95% CI 1.029–9.330, P=0.044), body mass index (OR 1.148, 95% CI 1.040–1.268, P=0.006), and CTRP9 levels (OR 0.726, 95% CI 0.592–0.890, P=0.002) were independently associated with the prevalence of OSA.

Conclusions

Plasma CTRP9 levels were independently related to the prevalence of OSA in patients with CAD, suggesting that CTRP9 might play a role in the pathogenesis of CAD exacerbated by OSA.

Figure 1. CTRP9 levels in OSA and non-OAS groups

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): National Natural Science Foundation of China

[Analysis of pathogenic composition and clinical characteristics of viral acute gastroenteritis in children under five years old in Beijing]

Objective: To understand the epidemiological characteristics and clinical features of rotavirus-, norovirus-, adenovirus-and astrovirus-associ ated acute gastroenteritis in children under 5 years old in Beijing from Octorber, 2015 to March, 2017. Methods: In the intestinal clinic of 6 hospitals in 6 districts of Beijing, information and stool samples of the first 30 patients with acute gastroenteritis who are under the age of 5 years are collected monthly.Rotavirus, norovirus, adenovirus and astrovirus are identified by PCR.Descriptive epidemiological method was used to describe the epidemiological characteristics of diarrhea caused by rotavirus, norovirus, adenovirus and astrovirus in Beijing. One-way analysis of variance was used to analyze the Vesikari clinical severity score of of acute gastroenteritis caused by each virus. Unconditional logistic regression analysis was used to analysis the associated factors of clinical features. Results: Of the 2 052 samples, 709 (34.6%) were non-mixed infections: the positive rate of rotavirus, norovirus, adenovirus and astrovirus were 20.0%, 7.5%, 4.2% and 2.9%, respectively. A total of 135 cases (6.6%) were mixed infection. The mean and standard deviation of Vesikari clinical severity score was 8.0±3.1 for rotavirus associated acute gastroenteritis, which was significantly higher than norovirus (6.4±2.4, P<0.001), adenovirus (6.2±2.1, P<0.001) and astrovirus (6.1±2.0, P<0.001). The comparison of clinical features showed that compared with astrovirus, the children under 5 years old infected with rotavirus were more likely to have a diarrhea ≥5 days (OR=3.334), have vomiting ≥3 times within one day (OR=8.788), have vomiting≥1 day (OR=3.963), have a Vesikari clinical severity score ≥11 severe cases (OR=13.194). Norovirus infected cases were prone to have vomiting≥3 times in 1 day (OR=5.710).Adenovirus infected cases were prone to have a diarrhea≥5 days (OR=2.616). When using rotavirus as a reference, children under 5 years of age were less likely to develop fever≥38.4 ℃ after infection with norovirus (OR=0.397) or adenovirus (OR=0.280). Conclusions: The results of this study showed that the characteristics of acute gastroenteritis caused by different viruses are different. The clinical symptoms caused by rotavirus are more serious. Children under 24 months of age are at high risk of rotavirus infection. Effective preventive measures such as vaccination should be taken as soon as possible.

Long-term outcome of posterior approach insertion of tunneled cuffed catheter: A single clinic retrospective analysis

BACKGROUND AND OBJECTIVES

For patients who rely on a tunneled cuffed catheter, the internal jugular vein is the preferred site of insertion. A few studies have suggested that the posterior approach for central lines is equivalent or better in comparison to the conventional central approach. However, there have been fewer studies examining tunneled cuffed catheter insertion using the posterior approach. We have performed many posterior insertions of tunneled cuffed catheters in our practice, and because the technique has not yet been comprehensively studied for long-term use, we performed a retrospective study to evaluate the safety and efficacy of posterior approach for tunneled cuffed catheter in maintained hemodialysis patients.

METHODS

A retrospective review was conducted of 200 hemodialysis patients who were treated with tunneled cuffed catheters over a period of 3 years. There were 104 patients in the study group, as well as a 96-patient control group, who underwent catheter insertion by central approach. The clinical follow-up data were collected and analyzed.

RESULTS

All catheters were successfully placed. The mean primary patency days per catheter were 712 catheter days for the study group and 585 catheter days for the control group. The episode of catheter infection was similar in both groups (p = 0.874), but the case of total catheter dysfunction was significantly lower in the study group compared to the control group (p = 0.006). The cumulative patency of catheters was higher in the study group than that in the control group (p = 0.02), while patient survival was the same in the two groups (p = 0.325).

CONCLUSION

The posterior approach is safe, and similar infection rates were observed with lower dysfunction rates compared to tunneled catheter insertion by the conventional central approach.

Contributions to Chinese fauna of Torrenticolidae Piersig, 1902 (Acari, Hydrachnidia), with the description of three new species

Five species of torrenticolid mites (Acari, Hydrachnidia), collected in the Anzihe and Qingliangfeng national nature reserves, R. P. China, are identified. Three species are described as new to science: Torrenticola pseudosiamis Gu & Guo, sp. nov., T. anziensis Gu & Guo, sp. nov., and Monatractides sichuanensis Gu & Guo, sp. nov. The other two species, M. macrocorpis Gu & Guo, 2019, M. xiaoxiensis Gu & Guo, 2019, are newly reported from Zhejiang Province. Descriptions and illustrations of these species are included.

Genetic investigation of nodal melanocytic nevi in cases of giant congenital melanocytic nevus

Nodal melanocytic nevi are common incidental findings in lymph nodes that have been removed during sentinel lymph node biopsy for melanoma. They can also occur in the local lymph nodes of the giant congenital nevus (GCN), but very little is known regarding nodal melanocytic nevi in the giant congenital nevus, especially at the genetic level. There are two theories that explain the possible pathogenesis of nodal melanocytic nevi, mechanical transport and arrested migration during embryogenesis. However, there have been few tests of these two theories at the molecular biology level until now. We used whole-exon sequencing to test these two theories at the gene level for the first time. In clonal evolution analysis of patient 1, whose tumor mutation burden (TMB) value was relatively stable, showed that the GCN and nodal nevus had the same initial origin and then diverged into two branches as a result of gene mutations. In contrast, analysis indicated that in the other patient, whose TMB value declined from 68.02/Mb in a GCN to 17.55/Mb in associated nodal nevi, these two samples were from different origins at the beginning, each with its own gene mutation. These results are consistent with the two respective theories at the molecular biological level. We provided the first tests of the two theories of pathogenesis of nodal melanocytic nevi at the gene level, and these findings may provide some clues for further study. In addition, not all nodal nevi should be treated as lymph node metastasis in clinical diagnosis, and we should make a comprehensive assessment and judgment of nodal melanocytic nevi based on morphology, immunological characteristics and fluorescence in situ hybridization (FISH) tests.

[Genetic changes and biological potential of proliferative nodule in congenital pigmented nevus]

Objective: To study the genetic changes and biological potential of proliferative nodule in congenital melanocytic nevus. Methods: Whole-exome sequencing was carried out using the technique of next-generation sequencing (NGS) in order to detect the genomic alterations of two cases of proliferative nodules (PN) in congenital melanocytic nevi (CMN). Twelve cases of CMN and ten cases of malignant melanoma were used as benign and malignant controls, respectively. Mutated genes that possessed statistically significant difference between benign and malignant controls were listed, according to what benign and malignant statuses were classified and clustered. The heatmaps of clustering analyses were depicted using heatmap package. Fluorescence in situ hybridization (FISH) was also used to validate the above results. Results: Eighty-six common somatic gene mutations were detected in two samples of PN. Compared with CMN, PN had 52 more mutated genes. Furthermore, 22 of these 52 mutated genes were also detected in malignant melanoma samples. Two cases of PN fell between benign CMN and malignant melanoma in germline mutation clustering. Both cases of PN were positive in the FISH tests. Conclusions: The genetic changes of PN partially overlap with those of CMN and malignant melanoma. Therefore, although most of the PN manifest as a benign lesion clinically, it may have certain malignant potential at the genetic level, and warrant long-term monitoring and follow-up.

Four new species of Torrenticola (Acari, Hydrachnidia, Torrenticolidae) from Northeastern China

Four new species of Torrenticola i.e. Torrenticola triextensio sp. nov., T. songhuaensis sp. nov., T. changbaiensis sp. nov., T. acrisarostrum sp. nov. are described from Jilin Province, P. R. China, bringing the total number of Chinese Torrenticola species to 36. This is the second report of water mites from Northeastern China in the last two decades.

Highly sensitive and specific detection of hepatitis B virus DNA and drug resistance mutations utilizing the PCR-based CRISPR-Cas13a system

OBJECTIVES

Undetectable or low-level hepatitis B virus (HBV) DNA and drug resistance mutations in patients may increase the risk of HBV transmission or cause active viral replication and other clinical problems. Here, we established a highly sensitive and practical method for HBV and drug resistance detection using a polymerase chain reaction (PCR) -based CRISPR-Cas13a detection system (referred to as PCR-CRISPR) and evaluated its detection capability using clinical samples.

METHODS

Specific CRISPR RNAs (crRNAs) are designed for HBV DNA detection and YMDD (tyrosine-methionine-aspartate-aspartate) variant identification. The HBV DNA was detected in 312 serum samples for HBV diagnosis using quantification PCR (qPCR) and PCR-CRISPR. Additionally, 424 serum samples for YMDD testing were detected by qPCR, direct sequencing, and our assay.

RESULTS

Using PCR-CRISPR, one copy per test of HBV DNA was detected with HBV-1 crRNA in 15 min after PCR amplification. Consistent results with qPCR were observed for 302 samples, while the remaining 10 samples with low-level HBV DNA were detectable by PCR-CRISPR and droplet digital PCR but not by qPCR. PCR-CRISPR diagnosed all 412 drug-resistant samples detected by the YMDD detection qPCR kit and direct sequencing, as well as the other 12 drug-resistant samples with low-level HBV DNA undetectable by qPCR and direct sequencing.

CONCLUSIONS

We developed a novel PCR-CRISPR method for highly sensitive and specific detection of HBV DNA and drug resistance mutations. One copy per test for HBV DNA and YMDD drug resistance mutations could be detected. This method has wide application prospects for the early detection of HBV infection, drug resistance monitoring and treatment guidance.

Estrogen-related receptor participates in regulating glycolysis and influences embryonic development in silkworm Bombyx mori

Estrogen-related receptors (ERRs) play indispensable roles in development, energy metabolism, and cancers and are metabolic switches in Drosophila. However, the mechanism underlying their metabolic role is unknown in insects. This study analysed the expression profiles of Bombyx mori ERR (BmERR), hexokinase (BmHK), pyruvate kinase (BmPK) and phosphofructokinase (BmPFK) during embryonic development. The expression of BmERR tended to be similar to that of the other genes. We observed a regulatory association between BmERR and glycolytic rate-limiting enzymes by BmERR overexpression, RNA interference (RNAi), and ERR inhibitors in B. mori embryo cells. Subsequently, ERR cis-regulation elements (ERREs) were predicted and identified in the BmPFK promoter. Transfection assays, electrophoretic mobility shift assays and chromatin immunoprecipitation showed that BmERR can bind to one of these elements to regulate the expression of BmPFK. ERREs were also predicted in the BmHK and BmPK promoters. In the eggs, the expression of glycolytic rate-limiting enzyme genes was suppressed when the expression of BmERR was interference by double-stranded BmERR, the glucose levels also was increased. Meanwhile, the development of silkworm embryos was delayed by about 1 day. These results indicate that BmERR can bind to the ERREs of glycolytic gene promoters and regulate the expression of glycolytic genes, ultimately affecting embryonic development in silkworms.

Pollution Gradients Altered the Bacterial Community Composition and Stochastic Process of Rural Polluted Ponds

Understanding the effects of pollution on ecological communities and the underlying mechanisms that drive them will helpful for selecting a method to mediate polluted ecosystems. Quantifying the relative importance of deterministic and stochastic processes is a very important issue in ecology. However, little is known about their effects on the succession of microbial communities in different pollution levels rural ponds. Also, the processes that govern bacterial communities in polluted ponds are poorly understood. In this study, the microbial communities in water and sediment from the ponds were investigated by using the 16S rRNA gene high-throughput sequencing technology. Meanwhile, we used null model analyses based on a taxonomic and phylogenetic metrics approach to test the microbial community assembly processes. Pollution levels were found to significantly alter the community composition and diversity of bacteria. In the sediment samples, the bacterial diversity indices decreased with increasing pollutant levels. Between-community analysis revealed that community assembly processes among water and sediment samples stochastic ratio both gradually decreased with the increased pollution levels, indicating a potential deterministic environmental filtering that is elicited by pollution. Our results identified assemblage drivers of bacterial community is important for improving the efficacies of ecological evaluation and remediation for contaminated freshwater systems.

[Summary of research in economic burden of hand, foot, and mouth disease in China]

Since 2010, the incidence of hand, foot, and mouth disease (HFMD) has ranked top in notifiable infectious disease in China, causing economic losses to many families and the society of China. This paper summarizes the related methods, results and problems systematically in the research of economic burden of HFMD in China to provide reference for the better estimation of the economic burden caused by HFMD. Many studies showed that HFMD, especially severe and fatal cases, had posed heavy economic burden on the society. To mitigate the burden caused by HFMD, it is necessary to decrease the risk of severe and fatal cases, as well as to reduce the incidence of mild cases.