A New Type of High-Efficiency and Portable Digital Electric Experiment Board

With the continuous advancement of digital electronic technology, the domestic emphasis on cultivating talents in the field of digital technology has been increasing. Our team designed an efficient and high-precision digital circuit experiment board that is small in size, easy to carry and store, and is not limited by the site. It can be used for experiments in dormitories, classrooms or training rooms. The designed digital signal generation board is easy to operate, low in error rate, flexible in structural design, and improves the stability, safety and reliability of the circuit

Substitution of manure for chemical fertilizer affects soil microbial community diversity, structure and function in greenhouse vegetable production systems

Soil microbial communities and enzyme activities together affect various ecosystem functions of soils. Fertilization, an important agricultural management practice, is known to modify soil microbial characteristics; however, inconsistent results have been reported. The aim of this research was to make a comparative study of the effects of different nitrogen (N) fertilizer rates and types (organic and inorganic) on soil physicochemical properties, enzyme activities and microbial attributes in a greenhouse vegetable production (GVP) system of Tianjin, China. Results showed that manure substitution of chemical fertilizer, especially at a higher substitution rate, improved soil physicochemical properties (higher soil organic C (SOC) and nutrient (available N and P) contents; lower bulk densities), promoted microbial growth (higher total phospholipid fatty acids and microbial biomass C contents) and activity (higher soil hydrolase activities). Manure application induced a higher fungi/bacteria ratio due to a lower response in bacterial than fungal growth. Also, manure application greatly increased bacterial stress indices, as well as microbial communities and functional diversity. The principal component analysis showed that the impact of manure on microbial communities and enzyme activities were more significant than those of chemical fertilizer. Furthermore, redundancy analysis indicated that SOC and total N strongly influenced the microbial composition, while SOC and ammonium-N strongly influenced the microbial activity. In conclusion, manure substitution of inorganic fertilizer, especially at a higher substitution rate, was more efficient for improving soil quality and biological functions.</p

Impact of maternal reproductive factors on cancer risks of offspring : a systematic review and meta-analysis of cohort studies

BackgroundA number of studies have reported on associations between reproductive factors, such as delivery methods, number of birth and breastfeeding, and incidence of cancer in children, but systematic reviews addressing this issue to date have important limitations, and no reviews have addressed the impact of reproductive factors on cancer over the full life course of offspring.MethodsWe performed a comprehensive search in MEDLINE, and Embase up to January 2020 and Web of Science up to 2018 July, including cohort studies reporting the association between maternal reproductive factors of age at birth, birth order, number of births, delivery methods, and breastfeeding duration and cancer in children. Teams of two reviewers independently extracted data and assessed risk of bias. We conducted random effects meta-analyses to estimate summary relative estimates, calculated absolute differences between those with and without risk factors, and used the GRADE approach to evaluate the certainty of evidence.ResultsFor most exposures and most cancers, we found no suggestion of a causal relation. We found low to very low certainty evidence of the following very small possible impact: higher maternal age at birth with adult multiple myeloma and lifetime uterine cervix cancer incidence; lower maternal age at birth with childhood overall cancer mortality (RR = 1.15, 95% CI = 1.01-1.30; AR/10,000 = 1, 95% CI = 0 to 2), adult leukemia and lifetime uterine cervix cancer incidence; higher birth order with adult melanoma, cervix uteri, corpus uteri, thyroid cancer incidence, lifetime lung, corpus uteri, prostate, testis, sarcoma, thyroid cancer incidence; larger number of birth with childhood brain (RR = 1.27, 95% CI = 1.06-1.52; AR/10,000 = 1, 95% CI = 0 to 2), leukemia (RR = 2.11, 95% CI = 1.62-2.75; AR/10,000 = 9, 95% CI = 5 to 14), lymphoma (RR = 4.66, 95% CI = 1.40-15.57; AR/10,000 = 11, 95% CI = 1 to 44) incidence, adult stomach, corpus uteri cancer incidence and lung cancer mortality, lifetime stomach, lung, uterine cervix, uterine corpus, multiple myeloma, testis cancer incidence; Caesarean delivery with childhood kidney cancer incidence (RR = 1.25, 95% CI = 1.01-1.55; AR/10,000 = 0, 95% CI = 0 to 1); and breastfeeding with adult colorectal cancer incidence.ConclusionVery small impacts existed between a number of reproductive factors and cancer incidence and mortality in children and the certainty of evidence was low to very low primarily due to observational design

Habitat segregation between two congeneric and introduced goby species

Spatial segregation is one of the most important mechanisms that facilitates coexistence among competing species. Large populations of two introduced and congeneric goby species (Rhinogobius giurinus and Rhinogobius cliffordpopei) now co-occur in Lake Erhai, a plateau lake in the Yunnan-Guizhou Plateau (China). Herein we quantified the spatio-temporal distribution of the two species to determine whether spatial segregation occurred within the same ecosystem. A total of 67,819 individuals of R. giurinus and 36,043 of R. cliffordpopei were sampled across four seasons. The results indicated that R. giurinus mostly occupied profundal habitat (PH) while R. cliffordpopei mainly used littoral habitat (LH). Correlation analysis revealed the abundance of R. giurinus was positively associated with deep water, silt and coarse sand substrata, whereas the distribution of R. cliffordpopei was positively associated with high densities of macrozooplanktons and high abundances of other fish species, high concentration of dissolved oxygen and high densities of submerged macrophytes. Except in spring, the body condition of R. giurinus was significantly higher in the PH than in the LH. The body condition of R. cliffordpopei did not differ significantly between habitats in the four seasons. These findings demonstrate that the two congeneric and introduced goby species occupy distinct habitats, indicating that spatial segregation enables coexistence of the two invasive species at high abundances within an ecosystem.Spatial segregation is one of the most important mechanisms that facilitates coexistence among competing species. Large populations of two introduced and congeneric goby species (Rhinogobius giurinus and Rhinogobius cliffordpopei) now co-occur in Lake Erhai, a plateau lake in the Yunnan-Guizhou Plateau (China). Herein we quantified the spatio-temporal distribution of the two species to determine whether spatial segregation occurred within the same ecosystem. A total of 67,819 individuals of R. giurinus and 36,043 of R. cliffordpopei were sampled across four seasons. The results indicated that R. giurinus mostly occupied profundal habitat (PH) while R. cliffordpopei mainly used littoral habitat (LH). Correlation analysis revealed the abundance of R. giurinus was positively associated with deep water, silt and coarse sand substrata, whereas the distribution of R. cliffordpopei was positively associated with high densities of macrozooplanktons and high abundances of other fish species, high concentration of dissolved oxygen and high densities of submerged macrophytes. Except in spring, the body condition of R. giurinus was significantly higher in the PH than in the LH. The body condition of R. cliffordpopei did not differ significantly between habitats in the four seasons. These findings demonstrate that the two congeneric and introduced goby species occupy distinct habitats, indicating that spatial segregation enables coexistence of the two invasive species at high abundances within an ecosystem

Status and historical changes in the fish community in Erhai Lake

Erhai Lake is the second largest freshwater lake on the Yunnan Plateau, Southwest China. In recent decades, a number of exotic fish species have been introduced into the lake and the fish community has changed considerably. We evaluated the status of the fish community based on surveys with multimesh gillnet, trap net, and benthic fyke-net between May 2009 and April 2012. In addition, we evaluated the change in the community using historical data (1952-2010) describing the fish community and fishery harvest. The current fish community is dominated by small-sized fishes, including Pseudorasbora parva, Rhinogobius giurinus, Micropercops swinhonis, Hemiculter leucisculus, and Rhinogobius cliffordpopei. These accounted for 87.7% of the 22 546 total specimens collected. Omnivorous and carnivorous species dominated the community. A canonical correspondence analysis (CCA) plot revealed that the distribution of fishes in the lake is influenced by aquatic plants, water temperature, pH, and season. The abundance of indigenous species has declined sharply, and a majority of endemic species have been extirpated from the lake (a decrease from seven to two species). In contrast, the number of exotic species has increased since the 1960s to a total of 22 at present. The fishery harvest decreased initially following the 1960s, but has since increased due to the introduction of non-native fish and stocking of native fish. The fishery harvest was significantly correlated with total nitrogen, not total phosphorus, during the past 20 years. Based on our results, we discuss recommendations for the restoration and conservation of the fish resources in Erhai Lake.Erhai Lake is the second largest freshwater lake on the Yunnan Plateau, Southwest China. In recent decades, a number of exotic fish species have been introduced into the lake and the fish community has changed considerably. We evaluated the status of the fish community based on surveys with multimesh gillnet, trap net, and benthic fyke-net between May 2009 and April 2012. In addition, we evaluated the change in the community using historical data (1952-2010) describing the fish community and fishery harvest. The current fish community is dominated by small-sized fishes, including Pseudorasbora parva, Rhinogobius giurinus, Micropercops swinhonis, Hemiculter leucisculus, and Rhinogobius cliffordpopei. These accounted for 87.7% of the 22 546 total specimens collected. Omnivorous and carnivorous species dominated the community. A canonical correspondence analysis (CCA) plot revealed that the distribution of fishes in the lake is influenced by aquatic plants, water temperature, pH, and season. The abundance of indigenous species has declined sharply, and a majority of endemic species have been extirpated from the lake (a decrease from seven to two species). In contrast, the number of exotic species has increased since the 1960s to a total of 22 at present. The fishery harvest decreased initially following the 1960s, but has since increased due to the introduction of non-native fish and stocking of native fish. The fishery harvest was significantly correlated with total nitrogen, not total phosphorus, during the past 20 years. Based on our results, we discuss recommendations for the restoration and conservation of the fish resources in Erhai Lake

Machine Learning for Prediction of Sudden Cardiac Death in Heart Failure Patients With Low Left Ventricular Ejection Fraction: Study Protocol for a Retrospective Multicentre Registry in China

Introduction: Left ventricular ejection fraction (LVEF) ≤35%, as current significant implantable cardioverter-defibrillator (ICD) indication for primary prevention of sudden cardiac death (SCD) in heart failure (HF) patients, has been widely recognised to be inefficient. Improvement of patient selection for low LVEF (≤35%) is needed to optimise deployment of ICD. Most of the existing prediction models are not appropriate to identify ICD candidates at high risk of SCD in HF patients with low LVEF. Compared with traditional statistical analysis, machine learning (ML) can employ computer algorithms to identify patterns in large datasets, analyse rules automatically and build both linear and non-linear models in order to make data-driven predictions. This study is aimed to develop and validate new models using ML to improve the prediction of SCD in HF patients with low LVEF. Methods and analysis: We will conduct a retroprospective, multicentre, observational registry of Chinese HF patients with low LVEF. The HF patients with LVEF ≤35% after optimised medication at least 3 months will be enrolled in this study. The primary endpoints are all-cause death and SCD. The secondary endpoints are malignant arrhythmia, sudden cardiac arrest, cardiopulmonary resuscitation and rehospitalisation due to HF. The baseline demographic, clinical, biological, electrophysiological, social and psychological variables will be collected. Both ML and traditional multivariable Cox proportional hazards regression models will be developed and compared in the prediction of SCD. Moreover, the ML model will be validated in a prospective study. Ethics and dissemination: The study protocol has been approved by the Ethics Committee of the First Affiliated Hospital of Nanjing Medical University (2017-SR-06). All results of this study will be published in international peer-reviewed journals and presented at relevant conferences

Fine mapping of genetic polymorphisms of pulmonary tuberculosis within chromosome 18q11.2 in the Chinese population: a case-control study

<p>Abstract</p> <p>Background</p> <p>Recently, one genome-wide association study identified a susceptibility locus of rs4331426 on chromosome 18q11.2 for tuberculosis in the African population. To validate the significance of this susceptibility locus in other areas, we conducted a case-control study in the Chinese population.</p> <p>Methods</p> <p>The present study consisted of 578 cases and 756 controls. The SNP rs4331426 and other six tag SNPs in the 100 Kbp up and down stream of rs4331426 on chromosome 18q11.2 were genotyped by using the Taqman-based allelic discrimination system.</p> <p>Results</p> <p>As compared with the findings from the African population, genetic variation of the SNP rs4331426 was rare among the Chinese. No significant differences were observed in genotypes or allele frequencies of the tag SNPs between cases and controls either before or after adjusting for age, sex, education, smoking, and drinking history. However, we observed strong linkage disequilibrium of SNPs. Constructed haplotypes within this block were linked the altered risks of tuberculosis. For example, in comparison with the common haplotype AA_{(rs8087945-rs12456774)}, haplotypes AG_{(rs8087945-rs12456774)}and GA_{(rs8087945-rs12456774)}were associated with a decreased risk of tuberculosis, with the adjusted odds ratio(95% confidence interval) of 0.34(0.27-0.42) and 0.22(0.16-0.29), respectively.</p> <p>Conclusions</p> <p>Susceptibility locus of rs4331426 discovered in the African population could not be validated in the Chinese population. None of genetic polymorphisms we genotyped were related to tuberculosis in the single-point analysis. However, haplotypes on chromosome 18q11.2 might contribute to an individual's susceptibility. More work is necessary to identify the true causative variants of tuberculosis.</p

Benefits and harms of direct oral anticoagulation and low molecular weight heparin for thromboprophylaxis in patients undergoing non-cardiac surgery : systematic review and network meta-analysis of randomised trials

OBJECTIVE To systematically compare the effect of direct oral anticoagulants and low molecular weight heparin for thromboprophylaxis on the benefits and harms to patients undergoing non-cardiac surgery. DESIGN Systematic review and network meta-analysis of randomised controlled trials. DATA SOURCES Medline, Embase, and the Cochrane Central Register of Controlled Trials (CENTRAL), up to August 2021. REVIEW METHODS Randomised controlled trials in adults undergoing non-cardiac surgery were selected, comparing low molecular weight heparin (prophylactic (low) or higher dose) with direct oral anticoagulants or with no active treatment. Main outcomes were symptomatic venous thromboembolism, symptomatic pulmonary embolism, and major bleeding. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used for network meta-analyses. Abstracts and full texts were screened independently in duplicate. Data were abstracted on study participants, interventions, and outcomes, and risk of bias was assessed independently in duplicate. Frequentist network meta-analysis with multivariate random effects models provided odds ratios with 95% confidence intervals, and GRADE (grading of recommendations, assessment, development, and evaluation) assessments indicated the certainty of the evidence. RESULTS 68 randomised controlled trials were included (51 orthopaedic, 10 general, four gynaecological, two thoracic, and one urological surgery), involving 45 445 patients. Low dose (odds ratio 0.33, 95% confidence interval 0.16 to 0.67) and high dose (0.19, 0.07 to 0.54) low molecular weight heparin, and direct oral anticoagulants (0.17, 0.07 to 0.41) reduced symptomatic venous thromboembolism compared with no active treatment, with absolute risk differences of 1-100 per 1000 patients, depending on baseline risks (certainty of evidence, moderate to high). None of the active agents reduced symptomatic pulmonary embolism (certainty of evidence, low to moderate). Direct oral anticoagulants and low molecular weight heparin were associated with a 2-3-fold increase in the odds of major bleeding compared with no active treatment (certainty of evidence, moderate to high), with absolute risk differences as high as 50 per 1000 in patients at high risk. Compared with low dose low molecular weight heparin, high dose low molecular weight heparin did not reduce symptomatic venous thromboembolism (0.57, 0.26 to 1.27) but increased major bleeding (1.87, 1.06 to 3.31); direct oral anticoagulants reduced symptomatic venous thromboembolism (0.53, 0.32 to 0.89) and did not increase major bleeding (1.23, 0.89 to 1.69). CONCLUSIONS Direct oral anticoagulants and low molecular weight heparin reduced venous thromboembolism compared with no active treatment but probably increased major bleeding to a similar extent. Direct oral anticoagulants probably prevent symptomatic venous thromboembolism to a greater extent than prophylactic low molecular weight heparin.Peer reviewe

Aryl Hydrocarbon Receptor Promotes IL-10 Expression in Inflammatory Macrophages Through Src-STAT3 Signaling Pathway

The aryl hydrocarbon receptor (AhR) is an important immune regulator with a role in inflammatory response. However, the role of AhR in IL-10 production by inflammatory macrophages is currently unknown. In this study, we investigated LPS-induced IL-10 expression in macrophages from AhR-KO mice and AhR-overexpressing RAW264.7 cells. AhR was highly expressed after LPS stimulation through NF-κB pathway. Loss of AhR resulted in reduced IL-10 expression in LPS-induced macrophages. Moreover, the IL-10 expression was elevated in LPS-induced AhR-overexpressing RAW264.7 cells. Maximal IL-10 expression was dependent on an AhR non-genomic pathway closely related to Src and STAT3. Furthermore, AhR-associated Src activity was responsible for tyrosine phosphorylation of STAT3 and IL-10 expression by inflammatory macrophages. Adoptive transfer of AhR-expressing macrophages protected mice against LPS-induced peritonitis associated with high IL-10 production. In conclusion, we identified the AhR-Src-STAT3-IL-10 signaling pathway as a critical pathway in the immune regulation of inflammatory macrophages, It suggests that AhR may be a potential therapeutic target in immune response