In vitro bio-corrosion behaviors of biodegradable AZ31B magnesium alloy under static stresses of different forms and magnitudes

Biomedical degradable materials would be subjected to different degrees and forms of static stress after being implanted in the human body.In this work,the biocorrosion behaviors of AZ31B magnesium alloy under different stress forms with different magnitudes(20~150MPa)were studied.It was found that the corrosion behaviors at stressed conditions were severer than those at unstressed conditions and corrosion rates were obviously accelerated.The biocorrosion behaviors are more sensitive to the effects of tensile loads than to compressive loads.A biocorrosion numerical model on the degradation process of Mg alloy under static loads was established.The corrosion current density(i_(corr))of Mg alloy and the applied static stress(σ)matches a linear relationship of ln i_(corr)~σwell during the early stage(within 24 hrs)while deviated gradually in the latter period of corrosion.This work could provide a guidance and theoretical reference for further researches on the biocorrosion behaviors and practical clinical applications of the biomedical materials subjected to physiological loads.

Controlling dispersion and morphology of MoS2 nanospheres by hydrothermal method using SiO2 as template

Monodispersed MoS_2 nanospheres were successfully synthesized by using SiO_2 as hard template. The size and morphology of the MoS_2 nanospheres could be finely controlled by the content of SiO_2 and sulfur precursors. Furthermore, higher surface area of monodispersed MoS_2 nanospheres exhibited high reaction rate for hydrodesulfurization(HDS) of dibenzenethiophene(DBT).

Polyetheramide Templated Synthesis of Monodisperse Mn_3O_4 Nanoparticles with Controlled Size and Study of the Electrochemical Properties

Monodisperse Mn3O4 nanoparticles were prepared solvothermally starting from manganese acetate by using polyether amide block copolymers(Pebax2533) as a template in isopropanol. The diameter of the nanoparticles in the range of 8.7 nm^31.5 nm was decreased with increase of Pebax2533 concentration.The electrochemical properties and application in supercapacitor of Mn3O4 nanoparticles were further studied.The results showed that smaller nanoparticles had a larger capacitance. The higher capacitance of 217.5 F/g at a current density of 0.5 A/g was obtained on 8.7 nm Mn3O4 nanoparticles. The specific capacitance retention of 82% was maintained after 500 times of continuous charge-discharge cycles.

Amide-linked covalent organic frameworks as efficient heterogeneous photocatalysts in water

Semiconductor photocatalysts play an indispensable role in the photocatalytic process.Two-dimensional covalent organic frameworks(2D-COFs),as a kind of innovative photocatalyst,have garnered tremendous attention.Herein,we report an amide-linked 2D-COF(COF-JLU19)with outstanding photocatalytic performance in water,designed through a multi-synergistic approach.The synergistic effects of the high porosity,photoactive framework,high wettability,and stability of COF-JLU19 led to an unprecedented enhancement in the photocatalytic activity and recyclability in water upon illumination by visible light.More importantly,amide-linked 2D-COF based electrospinning membranes were prepared,which also exhibited superior photocatalytic activity for the degradation of Rhodamine B in water with sunlight.This study highlights the potential of the multi-synergistic approach as a universal rule for developing COF-based photocatalysts to address environmental and energy challenges.

IMPACT OF DYNAMICAL HYDRATION SHELL AROUND HA PROTEIN ON NONLINEAR CONCENTRATION DEPENDENT T-RAYS ABSORPTION

T rays is sensitive to covalently cross linked proteins and can be used to probe unique dynamic properties of water surrounding a protein.In this paper,we demonstrate the unique abeorption properties of the dynamic hydnation shells deternined by hemagglutinin(HA)protein in ter-ahertz frequency.We study the changes arising fom diferent concentrations in detail and show that nonlinear absorption coefficient is induced by the dynamic hydration water.The binary and ternary component model were used to interpret the nonlinearity absorption behaviors and predict the thickness of the hydration shells around the HA protein in aquous phase.

Detection of Volatile Components in Leaves and Bark of Picrasma quassioides by GC-MS

[Objectives]This study aimed to analyze the volatile oil components of the leaves and bark of Picrasma quassioides.[Methods]The volatile oils in the leaves and bark of P.quassioides were extracted using steam distillation(SD)method and identified with gas chromatography-mass spectrometry(GC-MS).Based on the mass spectrum database(NiST08),combined with artificial spectrum analysis,referring to relevant literature,the base peak and relative abundance were compared to identify the volatile components of the leaves and bark.The relative content of each component was determined by peak area normalization method.[Results]A total of 24 and 23 chemical components were identified in the leaves and bark of P.quassioides,respectively,including 11 common components.[Conclusions]Leaf and bark are different tissues.They contain different volatile chemical components,of which the contents vary greatly.They should be treated differently in the further research and development of P.quassioides resources.

Directly targeting BAX for drug discovery:Therapeutic opportunities and challenges

For over two decades,the development of B-cell lymphoma-2(Bcl-2)family therapeutics has primarily focused on anti-apoptotic proteins,resulting in the first-in-class drugs called BH3 mimetics,especially for Bcl-2 inhibitor Venetoclax.The pro-apoptotic protein Bcl-2-associated X protein(BAX)plays a crucial role as the executioner protein of the mitochondrial regulated cell death,contributing to organismal development,tissue homeostasis,and immunity.The dysregulation of BAX is closely associated with the onset and progression of diseases characterized by pathologic cell survival or death,such as cancer,neurodegeneration,and heart failure.In addition to conducting thorough investigations into the physiological modulation of BAX,research on the regulatory mechanisms of small molecules identified through biochemical screening approaches has prompted the identification of functional and potentially druggable binding sites on BAX,as well as diverse all-molecule BAX modulators.This review presents recent advancements in elucidating the physiological and pharmacological modulation of BAX and in identifying potentially druggable binding sites on BAX.Furthermore,it highlights the structural and mechanistic insights into small-molecule modulators targeting diverse binding surfaces or conformations of BAX,offering a promising avenue for developing next-generation apoptosis modulators to treat a wide range of diseases associated with dysregulated cell death by directly targeting BAX.

Rational design of graphyne-based dual-atom site catalysts for CO oxidation

There are increasing concerns about the environmental impact of rising atmospheric carbon monoxide concentrations,thus it is necessary to develop new catalysts for efficient CO oxidation.Based on first-principles calculations,the potential ofγ-graphyne(GY)as substrate for metals in the 4th and 5th periods under single-atom and dual-atoms concentration modes has been systematically investigated.It was found that single-atom Co,Ir,Rh,and Ru could effectively oxidate CO molecules,especially for single Rh.Furthermore,proper atoms concentration could boost the CO oxidation activity by supplying more reaction centers,such as Rh^(2)/GY.It was determined that two Rh atoms in Rh^(2)/GY act different roles in the catalytic reaction:one structural and another functional.Screening tests suggest that substituting the structural Rh atom in the center of acetylenic ring by Co or Cu atom is a possible way to maintain the reaction performance while reducing the noble metal cost.This systemic investigation will help in understanding the fundamental reaction mechanisms on GY-based substrates.We emphasize that properly exposed frontier orbital of functional metal atom is crucial in adsorption configuration as well as entire catalytic performance.This study constructs a workflow and provides valuable information for rational design of CO oxidation catalysts.

Population Attributable Fractions for Modifiable Factors of Longevity and Healthy Longevity Among the Late-Elderly Aged 75 Years or Older—China,1998-2018

Summary What is already known about this topic?Limited evidence on healthy longevity was provided in the world,and no studies investigated the fractions of healthy longevity attributed to modifiable factors.What is added by this report?Incidences of longevity and healthy longevity in China are provided.It reveals that the total weighted population attributable fractions for lifestyles and all modifiable factors were 32.8% and 83.7% for longevity,respectively,and 30.4% and 73.4% for healthy longevity,respectively.What are the implications for public health practice?China has a high potential for longevity and healthy longevity.Strategies may be targeted at education and residence in early life as well as healthy lifestyles,disease prevention,and functional optimization in late life.

Terahertz-dependent PM2.5 monitoring and grading in the atmosphere

Rapid industrialization and economic development have led to serious pollution in the form of fine particulate matter(PM2.5,particulate matter with a diameter of less than 2.5 μm). In China, PM2.5 has been one of the most debated topics in councils of government and issues of public concern. Terahertz(THz) radiation was employed to measure the PM2.5 in the atmosphere from September 2014 to April 2015 in Beijing. Comparison of the PM2.5 level from the website with THz absorbance revealed a significant phenomenon: THz radiation can be used to monitor PM2.5 in the atmosphere. During Asia-Pacific Economic Cooperation(APEC) 2014, "APEC Blue" was also recorded in a THz system. The relationship between absorbance and PM2.5 demonstrates that THz radiation is an effective selection for air pollution grading. Based on the absorbance spectra, the elemental compositions were studied by two-dimensional correlation spectroscopy(2 DCOS) in conjunction with X-ray fluorescence.Several single absorption peaks were revealed and caused by sulphate from coal combustion, vehicle exhaust emissions and secondary reactions. Furthermore, mathematical algorithms, such as the BPANN and SVM, can process the THz absorbance data and greatly improve the precision of the estimation of PM2.5 mass. Our results suggest that THz spectroscopy can not only reveal the component information for pollution source determination, but quantitatively monitor the PM2.5 content for pollution level evaluation. Therefore, the use of THz radiation is a new method for future air pollution monitoring and grading systems.

Terahertz assessment of the atmospheric pollution during the first-ever red alert period in Beijing

Haze or smog episodes, which are characterized by the presence of particulate matter at diameters less than 2.5 μm （PM2.5）, have attracted increasing attention during the past few decades [ 1 ]. PM2.5 has adverse effects on human respiratory health as well as on air visibility [2,3]. In the Beijing-Tianjin-Hebei （BTH） region of China, haze has become especially serious in recent years because of industrial expansion and traffic-related emissions [4,5] （http：//news.xinhuanet.com/english/2016-01/07/c_134987525.htm; http：// news.cenews.com.cn/html/2016-01/07/content_38614.htm）. To protect public health, the first-ever red alert for smog in China was issued by the Beijing municipal environmental protection bureau （MEPB）,

Spontaneous decoherence of coupled harmonic oscillators confined in a ring

We study the spontaneous decoherence of coupled harmonic oscillators confined in a ring container, where the nearest-neighbor harmonic potentials are taken into consideration. Without any external symmetry-breaking field or surrounding environment, the quantum superposition state prepared in the relative degrees of freedom gradually loses its quantum coherence spontaneously.This spontaneous decoherence is interpreted by the gauge couplings between the center-of-mass and the relative degrees of freedoms, which actually originate from the symmetries of the ring geometry and the corresponding nontrivial boundary conditions.In particular, such spontaneous decoherence does not occur at all at the thermodynamic limit because the nontrivial boundary conditions become the trivial Born-von Karman boundary conditions when the perimeter of the ring container tends to infinity.Our investigation shows that a thermal macroscopic object with certain symmetries has a chance for its quantum properties to degrade even without applying an external symmetry-breaking field or surrounding environment.

Revisiting the relationship between composite multiscale entropy and THz optical parameters with exterior product

With the framework of exterior product,we investigate the relationship between composite multiscale entropy[CMSE]and refractive index and absorption coefficient by reanalyzing six concentrations of bovine serum albumin aqueous solutions from the published work.Two bivectors are constructed by CMSE and its square by the refractive index and absorption coefficient under vectorization.The desirable linear behaviors can be captured,not only between the defined two bivectors in normalized magnitudes,but also between the normalized magnitude of bivectors pertinent to CMSE and the magnitude of a single vector on the refractive index or absorption coefficient,with the processing of optimum selection.Besides that,the relationship between the coefficients of two bivectors is also considered.The results reveal that plenty of sound linear behaviors can be found and also suggest the scale of 15,16 and frequency of 0.2,0.21 THz are prominent for those linear behaviors.This work provides a new insight into the correlation between terahertz[THz]time and frequency domain information.

The influence of alternating cyclic dynamic loads with different low frequencies on the bio-corrosion behaviors of AZ31B magnesium alloy in vitro

The real physiological environment of human body is complicated with different degrees and forms of dynamic loads applied to implanted medical devices due to the daily activities of the patients,which would have impacts on the degradation behaviors of magnesium alloy implants.In this work,the bio-corrosion behaviors of AZ31B magnesium alloy under alternating cyclic dynamic loads with different low frequencies(0.1-2.5 Hz)were specially investigated.It was found that the bio-degradation performances under external dynamic stressed conditions were much severer than those under unstressed conditions and static loads.The corrosion rates were generally accelerated as the rise of cyclic frequency.Hereby a numerical model for the degradation process of Mg alloy was established.The corrosion current density icorr of Mg alloy and the applied loading frequency f matches a linear relationship of ln icorr∝f,which is the result of interactions between the cyclic alternating load and corrosive environment.This work could provide a theoretical reference and an experimental basis for further researches on the biodegradation behaviors of biomedical materials under dynamic conditions.

Characterizing PM2.5 in Beijing and Shanxi Province using terahertz radiation

Particles of aerodynamic diameter〈2.5 pm （PM/.5） caused extremely severe and persistent haze pollution is of concern in many cities. In this study, samples of PM2.5 were collected from atmosphere environment of Beijing and Shanxi Province, and analyzed using terahertz （THz） radiation. The transmission spectrum of PM2.5 in Shanxi Province had two distinct absorption peaks at 6.0 and 6.7 THz, and the curve was increasing on the whole. However, the transmission spectrum of PMa.5 in Beijing had obviously different variation tendency and the absorption peak was studied by monitoring PM2.5 masses in conjunction with two-dimensional correlation spectro- scopy （2DCOS）. By comparing the pollutant species and concentrations of Shanxi Province and Beijing over the time of collecting samples, the concentrations of sulfate and ammonium were similar, which contributed to emerge absorption bands in the same position. While the concentrations of organic matter （OM）, nitrate, chloride and elemental carbon （EC） were different. Furthermore, dust and some other inorganic ion are unique to Shanxi province, which lead to different variation tendency of the transmission spectrum of PM2.5. These results will be of importance for environmental monitoring and for control- ling PM emissions. According to this research, optical techniques, and especially spectral methods, should be considered for PM2.5 monitoring.

A proposed approach for detecting terahertz pulses by using double few-cycle laser pulses with opposite carrier envelope phases

Previous research shows that few-cycle laser（FCL） pulses with low energy and without a bias field can be used to coherently detect terahertz（THz） pulses. As we know, it is very difficult to stabilize the carrier envelope phase（CEP） of FCL pulses, i.e., there are some random fluctuations for the CEP. Here we theoretically investigate the influence of such instability on the accuracy of THz detection. Our results show that although there is an optimum CEP for THz detection, the fluctuations of the CEP will lead to terrible thorns on the detected THz waveform. In order to solve this problem, we propose an approach using two few-cycle laser pulses with opposite CEPs, i.e., their CEPs are differed by π.

Statistical Analysis of Articles Published in China CDC Weekly——Worldwide,2019-2020

Introduction:This study analyzed views and downloads of articles published in China CDC Weekly from 2019 to 2020 as part of an evaluation of the academic level and quality of the journal.Methods:The study included articles published between November 29,2019 and December 25,2020 and evaluated views and downloads through February 9,2021 using standard bibliometrics.We conducted network analysis with VOSviewer software.Results:There were 283 articles from 101 institutions published in China CDC Weekly during the analysis period,among which 22(21.8%)institutions were overseas institutions.There were 220 unique first authors,with 1.28 articles per first author.There were 2,404,882 views and 58,760 downloads in total.The article with the highest view and download counts had 1,244,826 views and 38,978 downloads.Article types with more than 4,500 views per article were Vital Surveillance,Notes from the Field,and Preplanned Studies.Subjects with more than 3,500 views per article were epidemiology of infectious diseases,epidemiology of non-infectious diseases,and maternal and child health.Articles with descriptive research and articles discussing public health monitoring received more attention,shown by larger average per article page views.Discussion:Study results can help the editorial department improve the journal’s international influence through targeted measures,such as adjusting article types according to view and download analyses and increasing the proportion of international manuscripts selected.