Preparation and Performance Investigation of Epoxy Resin-Based Permeable Concrete Containing Ceramsite.

Permeable concrete is an innovative type of concrete that provides a sustainable solution for stormwater management by allowing water to seep through and be filtered naturally. This study focuses on the preparation and performance investigation of an epoxy resin-based permeable concrete containing ceramsite. In this study, ceramsite, a lightweight aggregate, is used as a substitute for conventional aggregates in the concrete mixture. The epoxy resin is then added to improve the strength and durability of the concrete. A series of tests, including compressive strength, water permeability, and freeze-thaw resistance tests, are conducted to evaluate the performance of the epoxy resin-based permeable concrete. The results show that with an increasing epoxy resin binder-aggregate ratio, the compressive strength of the epoxy resin-based permeable concrete significantly increases while the permeability coefficient decreases. Different types of aggregates have varying effects on the compressive strength and permeability coefficient of epoxy resin-based permeable concrete, with high-strength clay ceramsite providing the highest compressive strength and lightweight ceramsite having the highest permeability coefficient. In addition, the discrete element simulation method effectively and feasibly determines the ultimate load and accurately simulates the compressive strength of the permeable cement-based mixture, consistent with the measured compressive strength. A quadratic polynomial regression analysis yielded an R2 value of around 0.93, showing a strong relationship between durability and freeze-thaw cycles. The findings contribute to the development of sustainable construction materials for stormwater management and offer potential applications in various infrastructure projects.

Prevalence, influencing factors and adverse consequences of workplace violence against nurses in China: A cross-sectional study.

AIMS: The primary objective of this study was to determine the prevalence of workplace violence among nurses in China and its association with demographic characteristics, quality of work life and coping styles. The secondary objective was to explore how nurses deal with workplace violence and the emotional/psychological impact of workplace violence on nurses. BACKGROUND: Workplace violence is a common occupational hazard that causes physical and psychological harm to nurses. METHODS: A cross-sectional study was conducted with 2769 nurses from China. A demographic information questionnaire, hospital workplace violence questionnaire, Chinese version of the work-related quality of life scale and coping style scale were used in this study. The Chi-squared test, Mann-Whitney U test and binary logistic regression analysis were used to investigate the effects of demographic characteristics, quality of work life and coping styles on nurses' workplace violence. RESULTS: A total of 49.12% of the nurses (n = 1360) had experienced at least one type of workplace violence in the past 6 months. Night shifts, work department, chronic diseases (odds ratio [OR] = 1.53, p < .001), sleep disorders (OR = 1.54, p < .001), frequent overtime (OR = 1.78, p < .001), adverse nursing events (OR = 2.01, p < .001) and passive coping (OR = 1.47, p < .001) were risk factors for workplace violence. Working conditions (OR = 0.61, p < .001), general well-being (OR = 0.65, p < .001) and positive coping (OR = 0.76, p < .001) were identified as protective factors for workplace violence. Nurses exposed to workplace violence experience various negative emotional and psychological consequences. CONCLUSIONS: Workplace violence is common among nurses in China. Good working conditions, general well-being and positive coping may help prevent workplace violence injuries. IMPLICATIONS FOR NURSING MANAGEMENT: Efforts should be made to improve and optimize existing workplace violence prevention measures, create and maintain a good working environment for health care workers and develop various coping styles or strategies to manage stress to reduce workplace violence. The cross-sectional study has been approved by the Ethics Committee of the First Affiliated Hospital of China Medical University, with the registration number 2019-221-2. Written informed consent was obtained prior to the survey.

An autonomous hybrid brain-computer interface system combined with eye-tracking in virtual environment.

BACKGROUND: Brain-computer interface (BCI) has become an effective human-machine interactive way. However, the performance of the traditional BCI system needs to be further improved, such as flexibility, robustness, and accuracy. We aim to develop an autonomous hybrid BCI system combined with eye-tracking for the control tasks in the virtual environment. NEW METHOD: This work developed an autonomous control strategy and proposed an effective fusion method for electroencephalogram (EEG) and eye tracking. For the autonomous control, the sliding window method was adopted to analyze the user's eye-gaze data. When the variance of eye-gaze data was less than the threshold, target recognition was triggered. EEG and eye-gaze data were synchronously collected and fused for classification. In addition, a fusion method based on particle swarm optimization (PSO) was proposed, which can find the best fusion weights to adapt to the differences of single modalities. RESULTS: EEG data and eye-gaze data of 15 subjects in steady-state visual evoked potentials (SSVEP) tasks were collected to evaluate the effectiveness of the hybrid BCI system. The results showed that the PSO fusion method performed best in all fusion methods. And the proposed hybrid BCI system obtained higher accuracy and information transfer rate (ITR) than the single-modality. COMPARISON WITH EXISTING METHODS: The PSO fusion method was compared with average weighting fusion, prior weighting fusion, support vector machine, decision tree, random forest, and extreme random tree. CONCLUSION: The proposed methods of autonomous control and dual-modal fusion can improve the flexibility, robustness and classification performance of the hybrid BCI system.

The S68G polymorphism is a compensatory mutation associated with the drug resistance mutation K65R in CRF01_AE strains.

BACKGROUND: The rate of S68G mutation in human immunodeficiency virus type 1 (HIV-1) reverse transcriptase has increased and is closely related to the K65R mutation among CRF01_AE-infected patients who failed treatment. We aimed to explore the temporal association of S68G and K65R mutations and disclose the role of the former on susceptibility to nucleotide/nucleoside reverse transcriptase inhibitor (NRTI) and viral replication with the K65R double mutations among CRF01_AE-infected patients who failed treatment. METHODS: The occurrence of S68G and K65R mutations was evaluated among HIV-1 of various subtypes in the global HIV Drug Resistance Database. The temporal association of S68G and K65R mutations was analyzed through next-generation sequencing in four CRF01_AE-infected patients who failed treatment with tenofovir/lamivudine/efavirenz. The impact of the S68G mutation on susceptibility to NRTI and replication fitness was analyzed using pseudovirus phenotypic resistance assays and growth competition assays, respectively. RESULTS: The frequency of the S68G mutation increased by 1.4-9.7% in almost all HIV subtypes and circulating recombinant forms in treatment-experienced patients, except subtype F. The S68G mutation often occurred in conjunction with the K65R mutation among RTI-treated patients, with frequencies ranging 21.1-61.7% in various subtypes. Next-generation sequencing revealed that the S68G mutation occurred following the K65R mutation in three of the four CRF01_AE-infected patients. In these three patients, there was no significant change detected in the half maximal inhibitory concentration for zidovudine, tenofovir, or lamivudine between the K65R and K65R/S68G mutations, as demonstrated by the phenotypic resistance assays. Virus stocks of the K65R and K65R/S68G mutations were mixed with 4:6, 1:1, and 9:1 and cultured for 13 days, the K65R/S68G mutants outgrew those of the K65R mutants irrespective of the input ratio. CONCLUSIONS: S68G may be a natural polymorphism and compensatory mutation of K65R selected by NRTIs in the CRF01_AE strain of HIV-1. This mutation does not affect susceptibility to NRTI; however, it improves the replication fitness of K65R mutants. This study deciphers the role of the S68G mutation in the HIV reverse transcriptase of the CRF01_AE strain and provides new evidence for the interpretation of drug-resistant mutations in non-B subtypes of HIV-1.