Epicatechin attenuates lead(Pb)-induced cognitive impairment in mice:regulation on Nrf2 signaling pathway,and interference on the interaction between Pb with albumin

Epicatechin(EC)was used in this study to antagonize the cognitive dysfunction caused by lead(Pb)exposure in mice.Eight-week-old male Kunming mice were treated with PbCl_(2)(20 mg/kg)and/or EC(50 mg/kg)by gavage administration for 4 weeks.Morris water maze test showed that EC could improve memory dysfunction induced by Pb.EC antagonized Ca^(2+)overload,activated Nrf2 signaling pathway and reduced the accumulation of Pb in the brain and serum,which suggested that EC might alter Pb distribution in mice.In vitro,spectroscopic analysis,potentiometric titration and docking studies were applied to inquiry into the interaction between bovine serum albumin(BSA)and Pb^(2+)in presence or absence of EC.EC was proved to chelate Pb^(2+)and reduced the interaction between BSA and Pb^(2+).In summary,EC might protect Pb-induced cognitive impairment by activating Nrf2 signaling pathway,and suppressing Pb accumulation via interference on the binding of Pb to albumin.

Survey of Framer Credit Demands in China with Tianjin as an Example

Giving farmers more rights and interests on land property is the basis of achieving balanced and coordinated economic development between urban and rural areas as well as building a sharing economy during the period of economic transition in China.Based on the survey data of suburban households of Tianjin,in this paper,measurement method was adopted to study factors influencing farmer s willingness on land management right mortgage.The results shows that the willingness of individual farmer on mortgage is not strong,however,their willingness on mortgage is bound to have a significant relationship with farmland right confirmation and land transfer and other factors.Finally,it is concluded that it is necessary to promote land transfer on the basis of land right of confirmation while carrying out farmland mortgage under the premise of large-scale operation in China.

Effect and Significance of Comprehensive Training in Infection Prevention and Control on the Psychological Health of Oral Health Staff

Background:Oral health staff have close contact with patients in the process of diagnosis and treatment,and it is inevitable for them to come into contact with patients’secretions.Therefore,oral health staff are at greater risk of infectious diseases in their daily work,and their psychological health is also greatly challenged.Objective:To study the effect and significance of comprehensive training in infection prevention and control on the psychological health of oral health staff.Methods:We selected 400 oral health staff from a tertiary stomatological hospital in Guangzhou,China in this study.The respondents were randomly divided into an intervention group and a control group.After the first round of investigation,the intervention group received comprehensive training in prevention and control of infection for three months,while the control group received no intervention.Results:The comprehensive training in infection prevention and control improved the respondents’psychological health and job satisfaction.Further strengthening infection prevention and control training for oral health staff will increase their self-confidence,improve their mental health,and increase their job satisfaction.Conclusion:For oral health staff,it is particularly important to formulate an effective and operable preventive and control training program and then implement it in a standardized manner.

Soil microbial activity and nutrients of evergreen broad-leaf forests in mid-subtropical region of China

To better understand the effects of forest suc- cession on soil microbial activity, a comparison of soil microbial properties and nutrients was conducted between three forest types representing a natural forest succession chronosequence. The study compared a pine （Pinus mas- soniana） forest （PF）, a pine and broadleaf mixed forest （MF） and an evergreen broadleaf forest （BF）, in the Yingzuijie Biosphere Reserve, Hunan Province, China. Results showed that soil nutrients in the MF and BF plots were higher than in the PF plots. The range in microbial biomass carbon followed a similar pattem with Be havingthe greatest values, 522-1022 mg kg-1, followed by Mr 368-569 mg kg-1, and finally, PF 193--449 mg kg-1. Soil nutrients were more strongly correlated with microbial biomass carbon than basal respiration or metabolic quo- tient. Overall, forest succession in the study site improved soil microbial properties and soil fertility, which in turn can increase primary productivity and carbon sequestration.

从“非典”和新冠肺炎疫情看如何做好疫情防控档案管理

做好疫情防控档案的收集、整理和利用工作对于提升我国的疫情防控水平具有重要的意义。因此,本文结合非典和新冠肺炎疫情,分析如何做好疫情防控档案管理。本文首先对疫情防控档案进行了定义,然后分析了疫情防控档案的特点和作用,接着对疫情防控资料的归档范围进行了明确,最后对疫情防控档案的管理明确了要求。

Study on the Water Quality and Protection Measures of Dongting Lake

From nitrogen and phosphorus,chemical oxygen demand,phytoplankton,and eutrophication,this article analyzes the current situation of water quality in the Dongting Lake area,and discusses the factors influencing the water quality of Dongting Lake. Based on the actual production,geographic characteristics and outstanding problem of grim water pollution situation in the Dongting Lake area,some specific proposed measures are put forward in order to provide the basis and reference for the future pollution control in the Dongting Lake area,such as strengthening the industrial pollution control,developing ecological agriculture,and enhancing ecological restoration and water quality early warning.

Comparative Study of Carbon Storage and Allocation Characteristics of Mature Evergreen Broad-leaved Forest

Evergreen broad-leaved forest is an important forest type in China.This paper analyzes the allocation characteristics of vegetation and soil carbon pool of evergreen broad-leaved forest,to understand the current status of research on the carbon storage of evergreen broadleaved forest as well as shortcomings.In the context of global climate change,it is necessary to carry out the long-term research of evergreen broad-leaved forest,in order to grasp the formation mechanism of evergreen broad-leaved forest productivity,and the impact of climate change on the carbon sequestration function of evergreen broad-leaved forest ecosystem.

Carbon Stock and Carbon Cycle of Wetland Ecosystem

Wetland ecosystem is an essential ecosystem in the world. Its organic carbon stock and carbon cycle are important basis of global carbon cycle researches and also major contents of global climate change researches. Researches have shown that wetland protection and restoration can promote carbon accumulation and reduce emission of greenhouse gases. This paper discussed influence of carbon stock and carbon balance of wetland ecosystem and emission of greenhouse gases,as well as the relationship between wetland and global climate changes. Finally,it made prospect on researches about carbon cycle of Dongting Lake.

Slicing and support structure generation for 3D printing directly on B-rep models

Traditional 3D printing is based on stereolithography or standard tessellation language models,which contain many redundant data and have low precision.This paper proposes a slicing and support structure generation algorithm for 3D printing directly on boundary representation(B-rep)models.First,surface slicing is performed by efficiently computing the intersection curves between the faces of the B-rep models and each slicing plane.Then,the normals of the B-rep models are used to detect where the support structures should be located and the support structures are generated.Experimental results show the efficiency and stability of our algorithm.

Effect of Human Insulin on the Formation of Catheter-Associated <i>E. coli</i>Biofilms

Biofilm formation is essential for the survival and growth of Escherichia coli?in catheter-associated infections. Individuals with type 2 diabetes mellitus can excrete insulin and/or glucose in their urine. This population also has an increased incidence of urinary tract infections. The focus of this study was to determine if the composition of Foley catheter material affects biofilm formation by E. coli in a model system for type 2 diabetes mellitus. Rubber (lubricious-coated), silicon-coated, silver-coated and nitrofurazone-coated catheter segments (5 mm;n = 6) were tested. Catheter segments were added to E. coli ATCC25922 (104 CFU/ml, final concentration) in artificial urine alone, or with insulin (40 μU/ml) and/or glucose (0.1%). After incubation (18 h, 37?C, in air and anaerobically) the level of catheter-associated biofilm was determined by crystal violet staining (Abs550nm). Statistical analysis was done by ANOVA with post-hoc analysis (Tukey). Neither nitrofurazone-coated nor silver-coated catheters supported the formation of E. coli biofilm, regardless of growth condition tested. In contrast, under aerobic biofilm formation on silicon catheters was significantly higher (p E. coli controls. Biofilm formation was also significantly increased

3D magnetic field guided sunflower-like nanocatalytic active swarm targeting patients-derived organoids

Nanocatalytic medicine triggering in situ catalytic reactions has been considered as a promising strategy for tumor-selective therapeutics.However,the targeted distribution of nanocatalysts was still low,considering the absence of targeting propulsion capability.Here,encouraged by the fast-developing controllable microrobotics for targeting delivery,a sunflower-like nanocatalytic active swarm(SNCAS)controlled by a three-dimensional(3D)magnetic field was proposed for synergistic tumorselective and magnetic-actively tumor-targeting therapeutics.Furthermore,a patient-derived renal cancer cell 3D organoid was utilized for the verification of the effective tumor therapeutic outcomes.Under the targeted control of 3D magnetic field,the multiple cascade catalytic efficiency of SNCAS based on Fenton reaction was evaluated,resulting in efficient tumor cell apoptosis and death.For the patient-derived organoid treatment,the SNCAS presented significant lethality toward 3D organoid structure to induce cell apoptosis with the collapse of organoid morphology.The targeting efficiency was further enhanced under the magnetic-controllable of SNCAS.Overall,empowered by the magnetic control technology,the synergistic therapeutic strategy based on controllable swarm combined active targeting and tumor-specific catalytic nanomedicine has provided a novel way for advanced cancer therapy.Meanwhile,3D patient-derived organoids were proved as a powerful tool for the effectiveness verification of nanocatalytic medicine.

Highly effective and reproducible surface-enhanced Raman scattering substrates based on Ag pyramidal arrays

Close-packed Ag pyramidal arrays have been fabricated by using inverted pyramidal pits on Si as a template and used to generate plentiful and homogeneous surface-enhanced Raman scattering （SERS） hot sites. The sharp nanotip and the four edges of the Ag pyramid result in strong electromagnetic field enhancement with an average enhancement factor （EF） of 2.84 × 10^7. Moreover, the features of the close-packed Ag pyramidal array can be well controlled, which allows SERS substrates with good reproducibility to be obtained. The relative standard deviation （RSD） was lower than 8.78% both across a single substrate and different batches of substrates.

Optimization and Evaluation of Sputtering Barrier/Seed Layer in Through Silicon Via for 3-D Integration

The barrier/seed layer is a key issue in Through Silicon Via （TSV） technology for 3-D integration. Sputtering is an important deposition method for via metallization in semiconductor process. However, due to the limitation of sputtering and a ＂scallop＂ profile inside vias, poor step coverage of the barrier/seed layer always occurs in the via metallization process. In this paper, the effects of several sputter parameters （DC power, Ar pressure, deposition time, and substrate temperature） on thin film coverage for TSV applications are investigated. Robust TSVs with aspect ratio 5 ： 1 were obtained with optimized magnetron sputter parameters. In addition, the influences of different sputter parameters are compared and the conclusion could be used as a guideline to select appropriate parameter sets.

A coordinated bus bridging and metro short turning model in response to urban metro disruptions

When an urban metro disruption occurs,the urban metro usually operates in a short turning mode and bus bridging is the typical way to relink the disconnected stations.For emergency response models dealing with urban metro disruptions,minimizing passenger delay in the bus bridging process and the metro short turning process is usually the optimization objective.In this study,we simultaneously consider the passenger delay in the bus bridging process and the metro short turning process to develop a coordinated emergency response model dealing with urban metro disruptions.The proposed coordinated model is validated in an actual urban metro line using actual passenger boarding demand data.Useful insights in response to urban metro disruptions are obtained.