Construction of Hollow Carbon Nanofibers with Graphene Nanorods as Nano-Antennas for Lower-Frequency Microwave Absorption.

Electromagnetic (EM) wave absorbers at a lower-frequency region (2-8 GHz) require higher attenuation ability to achieve efficient absorption. However, the impedance match condition and attenuation ability are usually inversely related. Herein, one-dimensional hollow carbon nanofibers with graphene nanorods are prepared based on coaxial electrospinning technology. The morphology of graphene nanorods can be controlled by the annealing process. As the annealing time increased from 2 to 8 h, graphene nanospheres grew into graphene nanorods, which were catalyzed by Co catalysts derived from ZIF-67 nanoparticles. These nanorods can play the role of nano-antennas, which can guide EM waves into materials to enhance impedance match conditions. As a result, the carbon nanofibers with graphene nanorods possess a larger impedance match area with higher attenuation ability. The minimum reflection loss reaches -57.1 dB at a thickness of 4.6 mm, and the effective absorption bandwidth can cover almost both the S and C bands (2.4-8 GHz). This work contributes a meaningful perspective into the modulation of microwave absorption performance in the lower-frequency range.

Impact of slack resources on healthcare costs in tertiary and secondary hospitals: a panel data study of public hospitals in Beijing from 2015 to 2019.

OBJECTIVE: This study aims to explore the relationship between slack resources and cost consumption index in tertiary and secondary hospitals and to provide targeted healthcare resource utilisation recommendations for tertiary and secondary hospital managers. DESIGN: This is a panel data study of 51 public hospitals in Beijing from 2015 to 2019. SETTING: Tertiary and secondary public hospitals in Beijing. Data envelope analysis was used to calculate the slack resources. Regression models were used to explore the relationship between slack resources and healthcare costs. PARTICIPANTS: A total of 255 observations were collected from 33 tertiary hospitals and 18 secondary hospitals. OUTCOME MEASURES: Slack resources and healthcare costs in tertiary and secondary public hospitals in Beijing from 2015 to 2019. Linear or curve relationship between slack resources and healthcare costs in tertiary and secondary hospitals. RESULTS: The cost of healthcare in tertiary hospitals has always been higher than in secondary hospitals, and the slack resources in secondary hospitals have always been worse than in tertiary hospitals. For tertiary hospitals, the cubic coefficient of slack resources is significant (ß=-12.914, p<0.01) and the R2 of cubic regression is increased compared with linear and quadratic regression models, so there is a transposed S-shaped relationship between slack resources and cost consumption index. For secondary hospitals, only the first-order coefficient of slack resources in the linear regression was significant (ß=0.179, p<0.05), so slack resources in secondary hospitals were positively related to the cost consumption index. CONCLUSIONS: This study shows that slack resources' impact on healthcare costs differs in tertiary and secondary public hospitals. For tertiary hospitals, slack should be kept within a reasonable range to control excessive growth in healthcare costs. In secondary hospitals, keeping too many slack resources is not ideal, so managers should adopt strategies to improve competitiveness and service transformation.

Slack resources and individual performance of clinicians: the mediating role of job satisfaction and empirical evidence from public hospitals in Beijing, China.

BACKGROUND: Clinicians in Chinese public hospitals face a complex and severe clinical practice environment, and the individual performance of clinicians is key to improving the output of the healthcare industry. This study aims to explore the mechanism of slack resources in improving individual performance of clinicians and the role of job satisfaction in this process, while the study framework is based on the widely applied Job-Demands Resources theory. METHODS: Based on the study framework composed of slack resources, individual performance, and job satisfaction, hypotheses have been put forward, and questionnaires have been distributed to representative clinicians in tertiary public hospitals. Finally, 318 valid data collected from clinicians have been obtained. To verify the hypotheses, multiple linear regression models have been established to explore the relationship between variables, and the three-stage regression models have been used to verify the presence of mediating role. RESULTS: All four hypotheses proposed in this study have been proved to be held. Clinicians' job satisfaction has played a mediating role in the impact of slack resources and its three dimensions on individual performance. Among them, there has been a complete mediating role for staff slack, while time and space dimensions have played a partial mediating role in the impact of slack resources on individual performance. CONCLUSIONS: In public hospitals in environments where behavior is subject to significant government interference, it is necessary and feasible to retain appropriate slack resources to improve individual performance. From the perspective of resources management in hospitals, it is necessary for public hospitals to implement a strategy of reserving an appropriate portion of time, staff and space in order to have the conditions to improve clinicians' satisfaction. The existence of slack resources in public hospitals can improve the job satisfaction of clinicians, and then improve the individual performance through the process.

Ultrasound Frame-to-Volume Registration via Deep Learning for Interventional Guidance.

Fusing intraoperative 2-D ultrasound (US) frames with preoperative 3-D magnetic resonance (MR) images for guiding interventions has become the clinical gold standard in image-guided prostate cancer biopsy. However, developing an automatic image registration system for this application is challenging because of the modality gap between US/MR and the dimensionality gap between 2-D/3-D data. To overcome these challenges, we propose a novel US frame-to-volume registration (FVReg) pipeline to bridge the dimensionality gap between 2-D US frames and 3-D US volume. The developed pipeline is implemented using deep neural networks, which are fully automatic without requiring external tracking devices. The framework consists of three major components, including one) a frame-to-frame registration network (Frame2Frame) that estimates the current frame's 3-D spatial position based on previous video context, two) a frame-to-slice correction network (Frame2Slice) adjusting the estimated frame position using the 3-D US volumetric information, and three) a similarity filtering (SF) mechanism selecting the frame with the highest image similarity with the query frame. We validated our method on a clinical dataset with 618 subjects and tested its potential on real-time 2-D-US to 3-D-MR fusion navigation tasks. The proposed FVReg achieved an average target navigation error of 1.93 mm at 5-14 fps. Our source code is publicly available at https://github.com/DIAL-RPI/Frame-to-Volume-Registration.

A Carbon Is a Carbon Is a Carbon: Orbital-Free Simulations of Hydrocarbon Chemistry without Resort to Atom Types.

Semiclassical electrons (aka Lewis dots) have been a mainstay of chemists' thinking about molecular structure, polarizability, and reactivity for over a century. This utility has motivated the development of a corresponding quantitative description. Here we devise pairwise potentials that describe the behavior of valence electron pairs in hydrocarbons, including those in single, double, bridge, and bent bonds of linear, branched, and cyclic compounds, including anionic and cationic states. Beyond predicting structures and energies, the new subatomistic force field, dubbed LEWIS-B, efficiently simulates carbocation addition to a double bond and cation migration to a neighboring carbon. A crucial feature of the semiclassical electrons is variable spread, a fourth degree of freedom in addition to three Cartesian coordinates. In spontaneously adapting to different environments, the spread provides a signature of electron stability, with more contracted clouds where the electron interactions are favorable and expanded clouds where electrons are less tightly held. In addition, the pair potentials provide insight into the subtle trade-offs that govern isomerizations and reactions.

How slack resource affects hospital financial performance: The evidence from public hospitals in Beijing.

Background: Beijing is a city with high concentration and congestion of quality medical resources in China. While moderate slack seems to be beneficial to the improvement of medical quality. The actual relationship between hospital slack resources and their performance deserves further exploration. The study aims to analyze the slack resources of public hospitals in Beijing and investigate the relationship between slack and hospital financial performance. Finding a reasonable range of slack to optimize resource allocation. Methods: The panel data of 22 public hospitals in Beijing from 2005 to 2011 were selected as the sample, and the DEA model was applied to measure the main variable using DEAP 2.1. Descriptive statistical analysis was performed using Excel and STATA 15. Pearson correlation coefficient analysis and variance inflation factor test were performed for each variable to avoid multicollinearity. The HAUSMAN test was used to determine the appropriate panel regression model, and then to analyze the influence relationship between the variables. Results: From 2005 to 2011, hospital slack resource transitioned from high to low. The slack measured by the DEA model has an inverted U-shaped relationship with financial performance, with ROA increasing from 4.088 to 8.083 when slack increases from 0 to about 0.378, and then showing a decreasing trend; slack measured by financial indicators has a transposed S-shaped relationship with financial performance, with ROA increasing when slack increase from 3.772 to 5.933. Conclusions: The slack resources of Beijing public hospitals decreased year by year from 2005 to 2011. Moderate slack resources are conducive to the improvement of healthcare quality, but when slack resources increase to a certain level, it will have a negative impact on healthcare quality. Therefore, hospital managers should control the slack within a moderate range according to the hospital operation policy and development plan to obtain the best performance.

Cross-modal attention for multi-modal image registration.

In the past few years, convolutional neural networks (CNNs) have been proven powerful in extracting image features crucial for medical image registration. However, challenging applications and recent advances in computer vision suggest that CNNs are limited in their ability to understand the spatial correspondence between features, which is at the core of image registration. The issue is further exaggerated when it comes to multi-modal image registration, where the appearances of input images can differ significantly. This paper presents a novel cross-modal attention mechanism for correlating features extracted from the multi-modal input images and mapping such correlation to image registration transformation. To efficiently train the developed network, a contrastive learning-based pre-training method is also proposed to aid the network in extracting high-level features across the input modalities for the following cross-modal attention learning. We validated the proposed method on transrectal ultrasound (TRUS) to magnetic resonance (MR) registration, a clinically important procedure that benefits prostate cancer biopsy. Our experimental results demonstrate that for MR-TRUS registration, a deep neural network embedded with the cross-modal attention block outperforms other advanced CNN-based networks with ten times its size. We also incorporated visualization techniques to improve the interpretability of our network, which helps bring insights into the deep learning based image registration methods. The source code of our work is available at https://github.com/DIAL-RPI/Attention-Reg.

The Effect of Slack Resources on Innovation Performance and the Environmental Adaptability of Public Hospitals: The Empirical Evidence From Beijing of China.

Background: The development level of public hospitals has a direct impact on people's health. The reform of the medical industry in China has been gradually underway in recent years, while hospitals face a complex and uncertain environment. This study aims to explore the mechanism of resources slack in buffering environmental uncertainty and promoting innovation in public hospitals. Methods: Based on previous literature related to environmental adaptability, resources slack, and innovation performance, this study has conducted a literature review and has established a study framework. A questionnaire survey has been conducted among clinicians in representative tertiary public hospitals in Beijing. A total of 318 valid data have been eventually obtained, while regression models have been used to analyze the data. Results: Innovation performance has played a mediating role in the impact of both resources slack and its three dimensions on environmental adaptability of public hospitals. Among them, there has been a complete mediating effect for time slack, while there has been a partial mediating effect for staff and space dimensions. Conclusion: This study found that resources slack in public hospitals can improve environmental adaptability by affecting innovation performance. It is necessary for public hospitals to reserve resources slack to ensure that there is sufficient condition for innovation in the face of uncertain changes.

Facile synthesis of hierarchical MoS2/ZnS @ porous hollow carbon nanofibers for a stable Li metal anode.

Lithium metal is considered as an ideal anode candidate for next generation Li battery systems since its high capacity, low density, and low working potential. However, the uncontrollable growth of Li dendrites and infinite volume expansion impede the commercialized applications of Li-metal anodes. In this work, we rationally designed and constructed a hierarchical porous hollow carbon nanofiber decorated with diverse metal sulfides (MS-ZS@PHC). This composite scaffold has three advantages: First, the synergistic effect of multiple-size lithiophilic phases (nano ZnS and micro MoS2) can regulate Li ions nuclei and grow up homogenously on the scaffold. Second, the enlarged interplanar spacing of MoS2 microsphere on the fibers can provide abundant channels for Li ions transportation. Third, the porous scaffold can confine the volume expansion of Li metal anode during cycling. Therefore, in a symmetrical cell, the MS-ZS@PHC host presents a homogenous Li plating/stripping behavior and runs steadily for 1100 h at 5 mA cm-2 with a capacity of 5 mAh cm-2 and even for 700 h at 10 mA cm-2 with a capacity of 1 mAh cm-2. A full cell using MS-ZS@PHC /Li composite as anode and coupled with LiFePO4 as cathode delivers an excellent cyclic and rate performances.

Changes in efficiency of tertiary public general hospitals during the reform of public hospitals in Beijing, China.

BACKGROUND: In March 2009, the Chinese government formally launched a new round of healthcare reform. As the city with the highest concentration of high-quality medical resources in China, in the past 10 years, Beijing has also been exploring medical reforms. This article studied the performance and development of the 10 tertiary general public hospitals managed by Beijing Municipal Hospital Management Centre to provide policy basis for further deepening Beijing public hospital reform and improving hospital efficiency. METHODS: The 2011, 2015 and 2018 'Beijing Health Work Statistics' were used to evaluate the performance of Beijing's tertiary public general hospitals, based on the Pabon Lasso model and the data envelopment analysis (DEA) model. RESULTS: Based on the Pabon Lasso model, 60%, 70% and 70% of the hospitals were entirely efficient (zone 3) in 2011, 2015 and 2018. It shows that among the 10 general public hospitals in Beijing, efficient hospitals accounted for the majority and further increased during the reform period. The DEA model further illustrates this point and shows more effective hospitals (80%) than the Pabon Lasso model, showing the efficiency of these hospitals to be improved during the reform period. CONCLUSIONS: The efficiency of the 10 hospitals has gradually improved during the reform period, and the difficulty of seeing a doctor in Beijing at a national medical centre has been relieved to a certain extent. Combining the Pabon Lasso model and the DEA model can analyse hospital efficiency more comprehensively, and can prompt initial information for improving hospital efficiency, but the results also reflect some problems.

Bending the Curve: Molecular Manifestations of Electron Antisymmetry.

As very light fermions, electrons are governed by antisymmetric wave functions that lead to exchange integrals in the evaluation of the energy. Here we use the localized representation of orbitals to decompose the electronic energy in a fashion that isolates the enigmatic exchange contributions and characterizes their distinctive control over electron distributions. The key to this completely general analysis is considering the electrons in groups of three, drawing attention to the curvatures of pair potentials, rather than just their amplitudes and slopes. We show that a positive curvature at short distances is essential for the mutual distancing of electrons and a negative curvature at longer distances is essential to account for the influence of lone pairs on bond torsion. Neither curvature is available in the absence of the exchange contributions. Thus, although exchange energies are much shorter range than Coulomb energies, their influence on molecular geometry is profound and readily understood.

Magnetism and NIR dual-response polypyrrole-coated Fe3O4 nanoparticles for bacteria removal and inactivation.

Microbial contamination of water represents a great threat to the public health that has attracted worldwide attention. In this work, polypyrrole magnetic nanoparticles (Fe3O4@PPy NPs) with sterilization properties were fabricated. More specifically, the Fe3O4@PPy NPs obtained via aqueous dispersion polymerization and an in situ chemical oxidative polymerization exhibited a cationic surface and high photothermal conversion efficiency. More than 50% of bacteria adsorption can be achieved at a dosage of 100 µg/mL Fe3O4@PPy NPs under magnetic field, and high photothermal sterilization efficacy (~100%) can be obtained upon NIR exposure at the same dosage for 10 min. Noteworthy, the Fe3O4@PPy NPs can be recycled by magnetism and reused without affecting their photothermal sterilization capability. This study clearly provides experimental evidence of the great potential of Fe3O4@PPy NPs as stable and reusable nanocomposite materials for bacteria adsorption and photothermal sterilization performance. The application of Fe3O4@PPy NPs can realize enviromental-friendly bacterial contaminated water treatment as well as provide stratgies for synergistical antibacterial materials design.

Lifestyle pattern of middle school students in Guangzhou / 中国学校卫生

Objective@#To identify the lifestyle pattern of adolescents in Guangzhou and to provide a scientific basis for targeted and individualized interventions for adolescents with different lifestyle pattern.@*Methods@#A survey was conducted by questionnaire among 12 540 students from 27 middle schools in the urban area of Guangzhou using a convenient sampling method. The latent class model (LCM) was used to identify lifestyle patterns of adolescents, and further analyses were conducted to compare differences in dietary habits and willingness to exercise among the different classes.@*Results@#Three lifestyle patterns were identified based on the latent class model: "high sweet snacks/excessive screen time, sleep and exercise deficiency group", 3 797 people, accounting for 30.3%; "low nutrition diet/severe sleep and exercise deficiency group", 2 745 people, accounting for 21.9%; "general diet/sleep and exercise deficiency group", 5 998 people, accounting for 47.8%. Adolescents of different classes had different perceptions of their eating habits and different degrees of willingness to participate in physical exercise, these differences were statistically significant(χ 2=671.54, Z=153.16, P<0.05).@*Conclusion@#The results of the latent class model showed that the three classes of adolescents had their own unique characteristics. It is necessary to inform them of their needs, provide guidance and implement targeted interventions according to the unique characteristics of the different lifestyle patterns in empirical work.

Defect-rich honeycomb-like nickel cobalt sulfides on graphene through rapid microwave-induced synthesis for ultrahigh rate supercapacitors.

Nickel cobalt sulfides (NCS) are regarded as potential energy storage materials due to the versatile valent states and rich electrochemical activity, but their sluggish synthesis process and inferior rate performance hinder them from large-scale application. Herein, microwave-induced strategy has been employed for efficient synthesis of honeycomb-like NCS/graphene composites, which are explored as ultrahigh rate battery-type electrodes for supercapacitors. Due to the internal heat mechanism, the synthesis time of NCS by microwave could be shortened from hours to minutes. Density functional theory was simulated to uncover the interfacial effect between NCS and graphene, and the resulted Schottky barrier is in favor of enhancing redox activity and capacity. Ultimately, the obtained defect-rich nickel cobalt sulfides/graphene with thermal treatment (NCS/G-H) could exhibit a high specific capacitance of 1186 F g-1 at 1 A g-1 and sustain 89.8% capacity even after the increase of current density over 20 times, which is much superior to bare NCS and NCS/graphene. Furthermore, the assembled NCS/G-H hybrid supercapacitor delivers supreme energy density of 46.4 Wh kg-1, and retains outstanding long-term stability of 89.2% after 10 k cycles. These results indicate that the synthesized NCS/G-H by time-saving microwave-induced liquid process could be served as high rate materials for supercapacitors.

Effect of Bacillus natto solid-state fermentation on the functional constituents and properties of Ginkgo seeds.

In the present investigation, fibrinolytic Ginkgo seeds were produced by solid-state fermentation (SSF) with Bacillus natto strains, and some parameters of the fermentation processes were investigated. Under optimal fermentation conditions, the fibrinolytic activity of Ginkgo seeds reached 3,682 ± 43 IU/g with the fermentation parameters of relative humidity 80%, initial water content 73%, fermentation temperature 38°C, inoculation volume 18%, and fermentation time 38 hr, respectively. The fermented Ginkgo seeds possessed a superior potential for the production of Nattokinase. What's more, the fermented Ginkgo seeds possessed higher total flavonoid and lower ginkgolic acids contents, which could enhance bioactivity and guarantee food safety. Sensory evaluations indicated that Ginkgo seeds produced by SSF could also be consumed as a kind of popular food. PRACTICAL APPLICATIONS: Fermented food is popular in countries. It can not only improve the sensory properties of the products, reduce undesirable constituents, and make nutrients easily absorbable, but also improve the nutritional properties. Ginkgo biloba L is one of the oldest species that has existed on earth for more than 200 million years. However, the application of Ginkgo seeds has been limited because of the ginkgolic acids. In a previous study, immobilized Bacillus natto acted upon Ginkgo seeds to enhance the bioactivity and safety of fermented Ginkgo seeds. However, separating the fermented Ginkgo seeds from the liquid needs a large amount of energy. The solid-state fermentation of Ginkgo seeds is a good choice to produce functional Ginkgo seed products.

The development and application of in silico models for drug induced liver injury.

Drug-induced liver injury (DILI), caused by drugs, herbal agents or nutritional supplements, is a major issue for patients and the pharmaceutical industry. It has been a leading cause of clinical trials failure and withdrawal of FDA approval. In this research, we focused on in silico estimation of chemical DILI potential on humans based on structurally diverse organic chemicals. We developed a series of binary classification models using five different machine learning methods and eight different feature reduction methods. The model, developed with the support vector machine (SVM) and the MACCS fingerprint, performed best both on the test set and external validation. It achieved a prediction accuracy of 80.39% on the test set and 82.78% on external validation. We made this model available at http://opensource.vslead.com/. The user can freely predict the DILI potential of molecules. Furthermore, we analyzed the difference of distributions of 12 key physical-chemical properties between DILI-positive and DILI-negative compounds and 20 privileged substructures responsible for DILI were identified from the Klekota-Roth fingerprint. Moreover, since traditional Chinese medicine (TCM)-induced liver injury is also one of the major concerns among the toxic effects, we evaluated the DILI potential of TCM ingredients using the MACCS_SVM model developed in this study. We hope the model and privileged substructures could be useful complementary tools for chemical DILI evaluation.

Discovery of ERBB3 inhibitors for non-small cell lung cancer (NSCLC) via virtual screening.

As a member of the epidermal growth factor receptor family (EGFR) of receptor tyrosine kinases, ERBB3 plays an important role in mediating cellular growth and differentiation. Recent research works identified that CD74-NRG1 fusions lead to overexpression of the EGF-like domain of NRG1, and thus activate ERBB3 and PI3K-AKT signaling pathways. The fusion was detected in lung adenocarcinomas, and served as an important oncogenic factor for ERBB3 driven cancers. A sequential virtual screening strategy has been applied to ERBB3 crystal structure using databases of natural products and Chinese traditional medicine compounds, and led to identification of a group of small molecular compounds potentially capable of blocking ERBB3. Six small molecular compounds were selected for in vitro analysis. Five of these molecules significantly inhibited the growth of A549 cells. Among them, compound VS1 is the most promising one with IC50 values of 269.75 µM, comparing to the positive control of nimustine hydrochloride with IC50 values of 264.14 µM. With good specificity and predicted ADMET results, our results support the feasibility by using a pharmacophore of the compound VS1 for designing and optimization of ERBB3 inhibitors.