Pd/N-doped carbon dots@dendritic mesoporous silica nanospheres:A highly efficient catalyst for the hydrogenation of 4-nitrophenol

Highly dispersed Pd/N-doped carbon dots(Pd/NCDs)were successfully immobilized in the mesoporous channels of amino-functionalized dendritic mesoporous silica nanospheres(NMS).The synthesized Pd/NCDs@NMS catalyst exhibits outstanding performance in the catalytic reduction of 4-nitrophenol(4-NP),achieving a turnover frequency of 1461.8 mol·molPd^(-1)·h^(-1),with the conversion rate remaining above 80%after 11 cycles.Experiments and density functional theory calculations reveal that the NCDs significantly affect the electronic structure of Pd nanoparticles,leading to changes in the energy barriers for the adsorption of 4-NP at the Pd sites and the conversion of 4-NP reaction intermediates,which is a key factor contributing to the catalytic performance.This study offers a new strategy for synthesizing carbon-dot-modified metal-based catalysts.

Micro femoral head prosthesis in applications to collapsed femoral head necrosis in the weight-bearing dome(ARCO III):A case series with short-term follow-up

Osteonecrosis of the femoral head(ONFH)is mainly caused by a decrease in the vascular supply to the subchondral bone of the femoral head,leading to the death of bone cells,degeneration and necrosis of the subchondral bone,and eventually collapse of the femoral head.^([1])Early and accurate diagnosis is the key to successful hip-preserving therapy,and the size/location of necrosis is the main determinant for ONFH treatment.Previous studies have shown that many hip-preserving therapies achieved satisfactory results in ONFH patients with Association Research Circulation Osseous(ARCO)I–II.When ONFH progresses to ARCO IV with clinical manifestations of osteoarthrosis,total hip arthroplasty(THA)may be the only option.

Research on power control strategy of household-level electric power router based on hybrid energy storage droop control

In the light of user-side energy power control requirements, a power control strategy for a household-level EPR based on HES droop control is proposed, focusing on the on-grid, off-grid and seamless switching process. The system operating states are divided based on the DC bus voltage information with one converter used as a slack terminal to stabilize the DC bus voltage and the other converters as power terminals. In the on-grid mode, the GCC and the HES are used as the main control unit to achieve on-grid stable operation, whereas in the off-grid mode, the PV, HES and LC are used as the main control unit at different voltages to achieve stable operation of the island network. Finally, a DC MG system based on a household-level EPR is developed using the PSCAD / EMTDC simulation platform and the results show that the control strategy can effectively adjust the output of each subunit and maintain the stability of the DC bus voltage.

An improved Hummers method to synthesize graphene oxide using much less concentrated sulfuric acid

The production of graphene oxide with less acid is beneficial to reduce the costs and lower the impact on the environment,but it is still a great challenge.In this work,a relatively simple,safe method for synthesizing graphene oxide with much less acid(decrease∼40%)is proposed.With assistance of the heat absorbed from environment and reaction system,the temperature of reaction system of low acid can be well controlled.More interestingly,the graphite can be completely oxidized into graphite oxide by using much less acid,with lowering the production of high-concentration aqueous waste acid(>1 mol/L,decrease∼40%).A series of characterizations show that the prepared graphene oxide has similar yield and functional groups compared with that of using the conventional method.This work provides a safe and environmentally friendly choice for the large-scale production of graphene oxide and its derivative materials.

Ultrafast room-temperature reduction of graphene oxide by sodium borohydride,sodium molybdate and hydrochloric acid

Since graphene-based materials have shown great potential in many fields,it is important to explore ultrafast and high-efficient methods to synthesize reduced graphene oxide(rGO) using inexpensive reducing agents under mild conditions.Here,we reported a novel method for the ultrafast chemical reduction of graphene oxide(GO) at room temperature using sodium borohydride(NaBH_(4)),sodium molybdate(Na_(2)MoO_(4)) and hydrochloric acid(HCl).The reduction was carried out within 2 min.A series of characterization results revealed that the obtained reduced graphene oxide has higher reduction degree than that synthesized by NaBH_(4) alone at high temperature.Moreover,rGO electrode based on the present reducing method exhibited a superior specific capacitance of 139.8 F/g at a current density of1 A/g,indicating that it can be used as electrode materials for supercapacitors.

National incidence of joint dislocation in China:a retrospective survey of 512,187 individuals

Background:Joint dislocations significantly impact public health.However,a comprehensive study on the incidence,distribution,and risk factors for joint dislocations in China is lacking.We conducted the China National Joint Dislocation Study,which is a part of the China National Fracture Study conducted to obtain the national incidence and risk factors for traumatic fractures,and to investigate the incidence and risk factors for joint dislocations.Methods:For this national retrospective epidemiological study,512,187 participants were recruited using stratified random sampling and probability-proportional-to-size method from January 19 to May 16,2015.Participants who sustained joint dislocations of the trunk,arms,or legs(skull,sternum,and ribs being excluded)in 2014 were personally interviewed to obtain data on age,educational background,ethnic origin,occupation,geographic region,and urbanization degree.The joint-dislocation incidence was calculated based on age,sex,body site,and demographic factors.The risk factors for different groups were examined using multiple logistic regression.Results:One hundred and nineteen participants sustained 121 joint dislocations in 2014.The population-weighted incidence rate of joint dislocations of the trunk,arms,or legs was 0.22(95%confidence interval[CI]:0.16,0.27)per 1000 population in 2014(men,0.27[0.20,0.34];women,0.16[0.10,0.23]).For all ages,previous dislocation history(male:OR 42.33,95%confidence interval[CI]:12.03-148.90;female:OR 54.43,95%CI:17.37-170.50)and alcohol consumption(male:OR 3.50,95%CI:1.49-8.22;female:OR 2.65,95%CI:1.08-6.50)were risk factors for joint dislocation.Sleeping less than 7 h/day was a risk factor for men.Compared with children,women aged≥15 years(female 15-64 years:OR 0.16,95%CI:0.04-0.61;female≥65 years:OR 0.06,95%CI:0.01-0.41)were less likely to sustain joint dislocations.Women with more than three children were at higher dislocation risk than women without children(OR 6.92,95%CI:1.18-40.78).Conclusions:The up-to-date data on joint dislocation incidence,distribution,and risk factors can be used as a reference for national healthcare,prevention,and management in China.Specific strategies for decreasing alcohol consumption and encouraging adequate sleeping hours should be developed to prevent or reduce dislocation incidents.Trial Registration:Chinese Clinical Trial Registry,ChiCTR-EPR-15005878.