Sulfonic acid functionalized monolithic column for high selectivity capillary electrochromatography separation.

A new nano-scale spherical vinyl-functionalized covalent organic polymer (TAPT-DVA-COP) with uniform sizes around 300 nm was initially constructed using 2,5-divinyl-1,4-benzaldehyde (DVA) and 2,4,6-tris(4-aminophenyl)-1,3,5-triazine (TAPT) as monomers. Then, a sulfonic acid (-SO3H) modified COP termed COP-SO3H was developed based on post-sythesis method employing TAPT-DVA-COP as precursor. Capillary electrochromatography (CEC) monolithic columns were fabricated using the physical doping technique to exhibit the application potential of TAPT-DVA-COP and COP-SO3H. Compared to the TAPT-DVA-COP monolithic column, the COP-SO3H monolithic column achieved a highly selective separation between analytes with different properties, including monosubstituted benzenes, alkylbenzenes, hydroxybenzoates, nucleoside bases, and biogenic amines. Non-covalent interaction (NCI) analysis and experimental data show that the synergism of the sulfonic acid group and aromatic moieties on COP-SO3H endows the new stationary phase with diverse interactions, including ion exchange, hydrophobic, π-π and hydrogen bonding. In addition, the COP-SO3H monolithic column exhibited good reproducibility and excellent potential for the determination of hydroxybenzoates in compact powders and alkylbenzenes in effluent samples.

OAF is a DAF-like gene that controls ovule development in plants.

We previously found that the RING-type E3 ligase DEFECTIVE IN ANTHER DEHISCENCE1- (DAD1-) Activating Factor (DAF) controls anther dehiscence by activating the jasmonate biosynthetic pathway in Arabidopsis. Here, we show that in Arabidopsis, the DAF ancestor was duplicated into three genes (DAF, Ovule Activating Factor (OAF), DAFL2), which evolved divergent partial functions from their ancestor through subfunctionalization. In this case, DAF-DAD1-JA signaling regulates anther dehiscence, whereas OAF controls ovule development by negatively regulating cinnamyl alcohol dehydrogenase 9 (CAD9) activity and being negatively regulated by miR847 itself in Arabidopsis. Downregulation of OAF or upregulation of CAD9 and miR847 caused similar abortion of ovule formation due to precocious ovule lignification in transgenic Arabidopsis. Interestingly, only one DAF-like gene, PaOAF, exists in the monocot orchids, which has likely evolved through nonfunctionalization and maintains a conserved function as Arabidopsis OAF in regulating ovule development since defective ovules were observed in the virus-induced gene silencing (VIGS) PaOAF Phalaenopsis orchids. The absence of the DAF ortholog and its function in orchids is likely due to the evolution of stamens to a unique pollinium structure that lacks the feature of anther dehiscence. These findings expand the current knowledge underlying the multifunctional evolution and diverse functionalization of duplicate gene pairs within/among plants.

Copper(I)-Iodide Clusters as Carriers for Regulating and Visualizing Release of Aroma Molecules.

Achieving the controlled release of functional substances is indispensable in many aspects of life. Especially for the aroma molecules, their effective delivery of flavor and fragrance is challenging. Here, selected pyridines, as highly volatile odorants, were individually coordinated with copper(I) iodide (CuII) via a straightforward one-pot synthesis method, rapidly forming pure or even crystalline CuII cluster-based profragrances at room temperature. The obtained profragrances enabled the stable and high loading of volatile fragrances under ambient conditions and guaranteed their long-lasting release during heating. Furthermore, the intrinsic emission luminescence of these solid-state profragrances decayed along with the aroma release, which can serve as an additional indicator for monitoring the delivery process. This research sets a precedent for using CuII clusters as dual-purpose release agents and greatly expands their potential applications.

Role of social organization engagement in high-risk groups intervention against HIV/AIDS: a case study from 176 cities of China.

BACKGROUND: A high-risk prevention strategy is an effective way to fight against human immunodeficiency virus (HIV) and acquired immunodeficiency syndrome (AIDS). The China AIDS Fund for Non-Governmental Organizations (CAFNGO) was established in 2015 to help social organizations intervene to protect high-risk populations in 176 cities. This study aimed to evaluate the role of social organizations in high-risk population interventions against HIV/AIDS. METHODS: This study was based on the CAFNGO program from 2016 to 2020. The collected data included the number and types of social organizations participating in high-risk group interventions and the amount of funds obtained by these organizations each year. We explored the factors influencing the number of newly diagnosed AIDS cases using a spatial econometric model. Furthermore, we evaluated the effectiveness of intervention activities by comparing the percentages of the individuals who initially tested positive, and the individuals who took the confirmatory test, as well as those who retested positive and underwent the treatment. RESULTS: Overall, from 2016 to 2020, the number of social organizations involved in interventions to protect HIV/AIDS high-risk populations increased from 441 to 532, and the invested fund increased from $3.98 to $10.58 million. The number of newly diagnosed cases decreased from 9128 to 8546 during the same period. Although the number of cities with overall spatial correlations decreased, the spatial agglomeration effect persisted in the large cities. City-wise, the number of social organizations (direct effect 19.13), the permanent resident population (direct effect 0.12), GDP per capita (direct effect 17.58; indirect effect - 15.38), and passenger turnover volume (direct effect 5.50; indirect effect - 8.64) were the major factors influencing new positive cases confirmed through the testing interventions performed by the social organizations. The initial positive test rates among high-risk populations were below 5.5%, the retesting rates among those who initially tested positive were above 60%, and the treatment rates among diagnosed cases were above 70%. CONCLUSIONS: The spatial effect of social organizations participating in interventions targeting high-risk populations funded by CAFNGO is statistically significant. Nevertheless, despite the achievements of these social organizations in tracking new cases and encouraging treatment, a series of measures should be taken to further optimize the use of CAFNGO. Working data should be updated from social organizations to CAFNGO more frequently by establishing a data monitoring system to help better track newly diagnosed AIDS cases. Multichannel financing should be expanded as well.

[Determination of three penicillin residues in milk by solid-phase extraction-ultra performance liquid chromatography-tandem mass spectrometry using a covalent triazine framework sorbent].

A method based on solid-phase extraction-ultra performance liquid chromatography-tandem mass spectrometry (SPE-UPLC-MS/MS) was established for the determination of gpenicillin, cloxacillin, ampicillin residues in milk. Using self-made covalent triazine frameworks (CTFs) as the solid-phase extraction sorbents, the main factors influencing the efficiency of the solid-phase extraction columns, such as the sorbent amount, eluent type, eluent volume, and flow rate, were optimized. The extraction and purification conditions for the samples were also investigated. The optimal extraction effect was achieved at a flow rate of 3 mL/min with 60 mg CTFs and 6 mL eluent solution (acetonitrile). Separation was carried out on a Waters ACQUITY UPLC BEH C18 column, and 0.1% formic acid aqueous solution-acetonitrile was used as the mobile phases for gradient elution. The filtrate was detected by ultra performance liquid chromatography-tandem mass spectrometry, identified by electrospray ionization (ESI) in the positive mode using multiple reaction monitoring, and quantified using external standards. The calibration curves of the three penicillins showed good linearity and the correlation coefficients of the linear regression equations for the three target analytes were all greater than 0.999. The limits of detection (LODs) and limits of quantification (LOQs) were 0.05-0.10 µg/kg and 0.1-0.4 µg/kg, respectively. The average recoveries of the three analytes were 84.9%-94.1%, and the relative standard deviations (RSDs, n=5) were 1.66%-3.27%. Moreover, the mechanism of interaction between the CTFs and the target analytes was analyzed. The results revealed the existence of π-π and hydrogen-bond interactions between the CTFs and analytes. The results further indicated that the CTFs could be successfully used for the enrichment and purification of penicillins in milk. The proposed method has the advantages of high precision, good reproducibility, high resolution, and short analysis time, and it is suitable for the qualitative and quantitative determination of trace targets in complex matrices.

Bending modulus of the rippled graphene: the role of thickness.

Bending modulus is a key parameter to characterize the stiffness of materials. Commonly, it is believed that the bending modulus is closely related to the thickness as described by the thin plate theory. However, the thin plate theory fails in multilayer van der Waals materials like multilayer graphene, suggesting a more complex relationship between the bending modulus and thickness. Here, rippled graphene structures containing non-hexagonal carbon rings with different thicknesses are constructed to study the thickness-dependent bending modulus by the first-principles calculations. It is found that the bending modulus of rippled graphene depends on several factors, such as geometry, bending curvature, and thickness. Particularly, for the egg-tray graphene structures with similar structural pattern and bending curvature, i.e., eliminating the effects of structural pattern and bending curvature, the bending modulus could show a linear relationship to the thickness. Moreover, this linear relationship is very robust even in the case of changing the thickness through heteroatom doping.

Tunable bending modulus and bending limit of oxidized graphene.

Graphene is highly flexible and widely used in flexible devices. However, is the oxidized graphene more flexible than graphene? This is still under debate between simulations and experiments. By employing density functional theory calculations, we show that the bending modulus of oxidized graphene is quite tunable by changing the type and coverage of the functional groups, as well as the bending direction. The hydroxyl increases the bending modulus of graphene, but epoxide can degrade the bending modulus in the armchair bending direction, making the oxidized graphene more flexible than graphene. On the other hand, there exists a curvature limit during bending the oxidized graphene, where OH hydrogen bonds start to transform into O-H covalent bonds. Generally, our results demonstrate the effects of the functional groups and bending direction on the flexibility of oxidized graphene, which should be helpful to design graphene-based flexible devices.

Recommendation on global prevention and control of coronavirus disease 2019 in the early stage / 预防医学

@#Severe acute respiratory syndrome coronavirus（SARS-CoV-2）is highly infectious and people are generally susceptible to it. In this article,we reviewed current research into the epidemiological characteristics of coronavirus disease 2019（COVID-19）,introduced China's effective prevention and control experience,preliminarily summarized the phased Results of China's fight against the COVID-19,and reviewed the early measures taken by Singapore,Japan,Italy,Iran and South Korea. We recommended China’s prevention and control measures in response to COVID-19 to the world;appealed to pay attention to non-drug interventions,to strengthen the cooperation and sharing of COVID-19 epidemic data and research,to improve the global ability in respond to public health emergencies,and to reduce the impact of COVID-2019 on the sustainable development of economy and society.

The Gene ANTHER DEHISCENCE REPRESSOR (ADR) Controls Male Fertility by Suppressing the ROS Accumulation and Anther Cell Wall Thickening in Arabidopsis.

Male sterility in plants is caused by various stimuli such as hormone changes, stress, cytoplasmic alterations and nuclear gene mutations. The gene ANTHER DEHISCENCE REPRESSOR (ADR), which is involved in regulating male sterility in Arabidopsis, was functionally analyzed in this study. In ADR::GUS flowers, strong GUS activity was detected in the anthers of young flower buds but was low in mature flowers. ADR + GFP fusion proteins, which can be modified by N-myristoylation, were targeted to peroxisomes. Ectopic expression of ADR in transgenic Arabidopsis plants resulted in male sterility due to anther indehiscence. The defect in anther dehiscence in 35S::ADR flowers is due to the reduction of ROS accumulation, alteration of the secondary thickening in the anther endothecium and suppression of the expression of NST1 and NST2, which are required for anther dehiscence through regulation of secondary wall thickening in anther endothecial cells. This defect could be rescued by external application of hydrogen peroxide (H2O2). These results demonstrated that ADR must be N-myristoylated and targeted to the peroxisome during the early stages of flower development to negatively regulate anther dehiscence by suppressing ROS accumulation and NST1/NST2 expression.