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Abstract In rural China, the aging population faces unique challenges that affect their life satisfaction. These challenges are compounded by disparities in access to resources compared to urban areas, making it crucial to address these issues to ensure a dignified and fulfilling later life. Understanding and improving life satisfaction for this demographic is essential, not only for the well-being of the elderly but also for the overall social stability and economic sustainability of these communities. Using a rural sample from the Chinese Social Survey (CSS), this study investigates the interplay between social quality factors and life satisfaction among older adults in rural China. It focuses on the roles of socioeconomic security, social cohesion, social inclusion, and social empowerment in shaping the well-being of this demographic. It was found that the four conditional factors of social quality—socioeconomic security, social cohesion, social inclusion, and social empowerment—have different influences on life satisfaction among older adults in rural areas. The statistical model shows that the influence of absolute family income on social and economic security does not have statistical significance. In contrast, housing, pension insurance participation, and public safety perception positively affect life satisfaction among older adults in rural areas. Among the social cohesion factors, higher social morality, legal system evaluation, social identity, grassroots government, and interpersonal trust contribute to the life satisfaction of older adults in rural areas. Regarding social inclusion factors, good social tolerance, social equity, and perception of government public services can significantly improve life satisfaction among older adults in rural areas. For social empowerment factors, social participation helps expand the social support network of older adults in rural areas, enhancing their life satisfaction. Paths to improving the quality of rural society should be explored to improve relative poverty in rural areas. They should continue to be pursued to strengthen the old-age security system for older adults in rural areas. Further, the National Medium- and Long-Term Plan for Actively Responding to Population Aging should be the base for forming an elderly-friendly society. A good atmosphere promotes the participation of people, families, and society; supports social cohesion; enhances inclusion; and promotes social participation, improving life satisfaction.

Abstract Improving access to HIV/AIDS healthcare services is of great concern to government and policymakers striving to strengthen overall public health. How to reasonably allocate HIV/AIDS healthcare resources and maximize the equality of access to healthcare services across subdistrict areas has become an urgent problem to be solved. However, there is limited research on this topic in China. It is necessary to evaluate spatial accessibility to improve the accessibility and equity of HIV/AIDS healthcare services. In this study, the improved multi-modal two-step floating catchment area (2SFCA) and inverted 2SFCA (i2SFCA) methods are used to measure the spatial accessibility of HIV/AIDS healthcare services and the crowdedness of the healthcare sites in Shandong Province, China. Then, the theoretical supply and the optimal spatial distribution of resources are calculated and visualized by minimizing the accessibility gaps between demand locations. This study showed that the spatial accessibility of HIV/AIDS service resources in Shandong Province was concentrated and unevenly distributed, and the accessibility scores in the marginal areas of prefecture-level cities were significantly lower than those in other areas. Regions with a large number of doctors had significantly higher levels of spatial accessibility. The ART accessibility scores in the southwest of Shandong Province were higher than those in other regions. As the travel friction coefficient increased, the accessibility scores formed an approximately circular cluster distribution centered on the healthcare sites in geographical distribution. More ART drugs needed to be supplied in marginal areas and more doctors were needed to work on HIV/AIDS in urban areas to address the spatial distribution imbalance of HIV/AIDS healthcare services. This study profoundly analyzed the spatial accessibility of HIV/AIDS healthcare services and provided essential references for decision-makers. In addition, it gives a significant exploration for achieving the goal of equal access to HIV/AIDS healthcare services in the future.

Abstract The optimal treatment for acute intussusception has not yet been defined. In this study, we explored whether employing a liberal laparoscopic intervention for intussusception could lead to favorable outcomes. We performed a historical control analysis to evaluate the outcomes associated with this liberal surgical management protocol. This liberal surgical management protocol were revised to incorporate a new protocol centered around the laparoscopic approach. In some cases of acute intussusception, liberal laparoscopic exploration and intervention were undertaken without initial hydrostatic or pneumatic reduction. During the study interval, a retrospective review was conducted on a total of 3086 patients. These were categorized into two groups: 1338 cases before May 2019 (pre-protocol group) and 1748 cases after May 2019 (post-protocol group). Surgical intervention rates in the pre-protoco and post-protocol period were 10.2% and 27.4% respectively (odds ratio [OR] = 0.30 [95% CI 0.25–0.37]; p

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Abstract Background The need for pain management is increasing in pediatrics, but the side effects of overuse or abuse of analgesics can be harmful to children’s health and even life-threatening in severe cases. Methods Patients who underwent resection of Meckel’s diverticulum at the Children’s Hospital of Chongqing Medical University from July 1, 2019, to July 1, 2022, were included in this study. Opioids were administered through patient-controlled analgesia (PCA). Based on the preoperative choices made by the legal guardians, patients were stratified into two groups: PCA Group (PCAG) and Non-PCA Group (NPCAG). Data pertaining to the clinical characteristics and prognoses of these patients were subsequently collected and analyzed to assess the impact of opioid administration. Results In the study, a total of 126 patients were enrolled, with 72 allocated to the Patient-Controlled Analgesia Group (PCAG) and 54 to the Non-Patient-Controlled Analgesia Group (NPCAG). When compared to the NPCAG, the PCAG exhibited a longer duration of postoperative fasting (median 72 vs. 62 h, p = 0.044) and increased utilization of laxatives (12[16.7%] vs. 2[3.7%], p = 0.022). However, the PCAG also experienced higher incidences of intestinal stasis and abnormal intestinal dilation (13[18.1%] vs. 3[5.6%], p = 0.037). No statistically significant differences were observed in pain assessments at the conclusion of the surgical procedure (0 vs. 1[1.9%], p = 0.429) or within the first 24 h postoperatively (16[22.2%] vs. 18[33.3%], p = 0.164). Additionally, NPCAG patients did not necessitate increased administration of rescue analgesics (2[2.8%] vs. 4[7.4%], p = 0.432). Conclusions The administration of opioids did not demonstrably ameliorate postoperative pain but was associated with a heightened incidence of postoperative gastrointestinal tract dysfunction. The retrospective nature of the current research should be considered and should be clarified further.

High-precision time–frequency is widely used in time measurement, satellite navigation, scientific research, and other fields. With the rapid development of optical clock technology, the fractional frequency instability and uncertainty of optical clock have reached 10−18 orders of magnitude, which is expected to contribute to generating the International Atomic Time and may even be used to redefine the “second” in the future. Therefore, the long-distance transfer of time–frequency signals between optical atomic clocks is of great significance. Free-space optical frequency transfer technology is one of the important technologies for solving the space-based optical clock comparison because of its high transfer precision and easy networking characteristics. In order to solve the long-distance space-based optical clock comparison, this paper investigates a free-space active phase noise compensation method using an Acousto-Optic Modulator (AOM), based on the traditional optical fiber phase noise compensation scheme. This new method is more flexible and scalable than the optical fiber time–frequency transfer technology. The optical frequency transfer over a 64 m free-space link is demonstrated. The fractional frequency transfer instability during free running is 9.50 × 10−16 at 1 s, and 4.44 × 10−16 at 2000 s, and the fractional frequency instability after compensation is 7.10 × 10−17 at 1 s, 3.07 × 10−19 at 2000 s, which is about 1–3 orders of magnitude better than that in free running, and provides a feasible scheme for space-based optical clock comparison.

Amidation of lactobionic acid with N,N-dimethylaminopropyltriamine was conducted to obtain N-(3′-dimethylaminopropyl)-lactamido-3-aminopropane (DDLPD), which was quaternized with bromoalkanes of different carbon chain lengths to synthesize double-stranded lactosylamide quaternary ammonium salt N-[N′[3-(lactosylamide)]propyl-N′-alkyl] propyl-N,N-dimethyl-N-alkylammonium bromide (CnDDLPB, n = 8, 10, 12, 14, 16). The surface activity and the adsorption and aggregation behaviors of the surfactants were investigated via equilibrium surface tension, dynamic light scattering, and cryo-electron microscopy measurements in an aqueous solution. The application properties of the products in terms of wettability, emulsification, foam properties, antistatic, salt resistance, and bacteriostatic properties were tested. CnDDLPB exhibited a low equilibrium surface tension of 27.82 mN/m. With an increase in the carbon chain length, the critical micellar concentration of CnDDLPBD decreased. Cryo-electron microscopy revealed that all products except C8DDLPB formed stable monolayer, multi-layer, and multi-compartmental vesicle structures in an aqueous solution. C14DDLPB has the best emulsification performance on soybean oil, with a time of 16.6 min; C14DDLPB has good wetting and spreading properties on polytetrafluoroethylene (PTFE) when the length of carbon chain is from 8 to 14, and the contact angle can be lowered to 33°~40°; CnDDLPB has low foam, which is typical of low-foaming products; C8DDLPB and C10DDLPB both show good antistatic properties. C8DDLPB and C14DDLPB have good salt resistance, and C12DDLPB has the best antimicrobial property, with the inhibition rate of 99.29% and 95.28% for E. coli and Gluconococcus aureus, respectively, at a concentration of 350 ppm.

Abstract Backgroud The proportion of HIV-infected students in China showed an increasing trend. This study aimed to identify the epidemiological characteristics and the HIV care continuum for HIV-infected students in Shandong Province, China. Methods Case report and follow-up data of HIV-infected students were obtained from the National HIV/AIDS comprehensive response information management system. Logistic regression analyses were used to analyze the associating factors of HIV-infected students accepting CD4 + T cells (CD4) test and antiviral therapy (ART) in 30 days, and ArcGIS software was used for the spatial anlysis. Results From 2017 to 2019, 403 HIV-infected students were reported in Shandong Province. The majority of them were male (99.5%) and transmitted through homosexual sexual activity(92.1%). Most of them lived in Jinan city and Qingdao city. 68.5% (276 cases) accepted CD4 test in 30 days, and 48.6% (196 cases) started ART in 30 days. The heterosexual transmitted cases (AOR = 0.458, 95%CI: 0.210–0.998), patients accepting HIV care in western area (AOR = 0.266,95%CI: 0.147–0.481) were less likely to test CD4 within 30 days; patients aged 23–25 (AOR = 2.316, 95%CI: 1.009–5.316) and patients who had tested CD4 within 30 days (AOR = 4.377; 95%CI: 2.572–7.447) prefered to receive ART within 30 days; patients accepted HIV care in central area (AOR = 0.407; 95%CI: 0.251–0.657) and western area (AOR = 0.508; 95%CI: 0.261–0.989) and patients diagnosed by voluntary blood donation (AOR = 0.352; 95%CI: 0.144–0.864) were less willing to receive ART in 30 days. Conclusions The HIV care continuum of HIV-infected students in Shandong Province still needed strenghthing. More health education and case management should be done for cases transmitted through heterosexual behavior, accepted HIV care in central and western area, and diagnosed by voluntary blood donation.

BackgroundThe COVID-19 pandemic, caused by the SARS-CoV-2 virus, has necessitated reliable and authoritative information for public guidance. The World Health Organization (WHO) has been a primary source of such information, disseminating it through a question and answer format on its official website. Concurrently, ChatGPT 3.5 and 4.0, a deep learning-based natural language generation system, has shown potential in generating diverse text types based on user input. ObjectiveThis study evaluates the accuracy of COVID-19 information generated by ChatGPT 3.5 and 4.0, assessing its potential as a supplementary public information source during the pandemic. MethodsWe extracted 487 COVID-19–related questions from the WHO’s official website and used ChatGPT 3.5 and 4.0 to generate corresponding answers. These generated answers were then compared against the official WHO responses for evaluation. Two clinical experts scored the generated answers on a scale of 0-5 across 4 dimensions—accuracy, comprehensiveness, relevance, and clarity—with higher scores indicating better performance in each dimension. The WHO responses served as the reference for this assessment. Additionally, we used the BERT (Bidirectional Encoder Representations from Transformers) model to generate similarity scores (0-1) between the generated and official answers, providing a dual validation mechanism. ResultsThe mean (SD) scores for ChatGPT 3.5–generated answers were 3.47 (0.725) for accuracy, 3.89 (0.719) for comprehensiveness, 4.09 (0.787) for relevance, and 3.49 (0.809) for clarity. For ChatGPT 4.0, the mean (SD) scores were 4.15 (0.780), 4.47 (0.641), 4.56 (0.600), and 4.09 (0.698), respectively. All differences were statistically significant (P

IntroductionPrevious studies have indicated different immunological recovery trajectories based on CD4 count or CD4/CD8 ratio. However, these immune indicators are interconnected, and relying solely on one indicator may lead to inaccurate estimates. Therefore, it is essential to develop a comprehensive trajectory model that integrates CD4 count, CD8 count and CD4/CD8 ratio.MethodsWe utilized a group-based multi-trajectory model to characterize the latent cluster of recovery based on measurements of CD4 count, CD8 count and CD4/CD8 ratio over a period of up to 96 months following ART initiation. Subsequently, we investigated the characteristics associated with trajectory groups, especially sex and age. Cox model and Kaplan-Meier survival curve were employed to assess differences in all-cause, AIDS-related and non-AIDS related mortality between trajectory groups.ResultsA total of 14,718 eligible individuals were followed for a median of 55 months. Longitudinal model identified four subgroups: group 1 (32.5%, low CD4 and CD4/CD8 inversion), group 2 (25.9%, high CD8 and CD4/CD8 inversion), group 3 (27.2%, slow recovery of CD4 and CD4/CD8 inversion) and group 4 (14.4%, rapid increase of CD4 and normal CD4/CD8). Immune recovery was slower in male than in female, and in elders than in youngers. Compared to group 2, group 1 (adjusted hazard ratio [aHR]=3.28; 95% CI 2.33-4.60) and group 3 (aHR=1.56; 95% CI 1.09-2.24) had increased risk of all-cause mortality after adjusting for other factors. Besides, group 1 (aHR=2.17) and group 3 (aHR=1.58) had higher risk of non-AIDS related mortality, and group 1 (aHR=5.92) had significantly increased risk of AIDS related mortality.ConclusionLongitudinal trajectory analysis of multiple immune indicators can be employed to guide targeted interventions among vulnerable populations in clinical practice.

This paper considers a multi-depot heterogeneous vehicle routing problem (MDHVRP) with time windows, which is very crucial for hazardous materials transportation. For this reason, we formalize this problem as a multi-objective MDHVRP optimization model, where the actual load dependent risk of hazardous materials transportation is considered. To solve the optimization problem, we propose a hybrid multi-objective evolutionary algorithm (HMOEA) and a two-stage algorithm (TSA). In addition, we verify the performance of the proposed algorithms by experiments on the modified Solomon’s VRPTW examples. In the experiment, it can be seen from the distribution of Pareto solution sets and the convergence distribution of IGD values that HMOEA is significantly superior to the other three algorithms in searching for Pareto solutions, as well as in the convergence and diversity of the algorithm. HMOEA and TSA were compared, and the minimum cost obtained by TSA was 13.38% lower than HMOEA, while the minimum risk was 81.69% higher than HMOEA. The advantages of each algorithm in finding solutions in reality were analyzed. A comparison was made between multi-depots heterogeneous VRP and multi-depots homogeneous VRP in the C101 instance, and the results showed that scheduling heterogeneous vehicles would reduce risk and cost.

Abstract Zero‐shot learning (ZSL) is to identify target categories without labeled data, in which semantic information is used to transfer knowledge from some seen categories. In the existing Generalized Zero‐Shot Learning (GZSL) methods, domains shift problem always appeared during generating feature stage. In order to solve this problem, a new method to Auto‐Encode the Synthesis Pseudo Features for the GZSL task (AESPF‐GZSL) is proposed in this manuscript. Specifically, the AESPF‐GZSL method trains the generated features under the semantic auto‐encoder framework and exploits attention mechanism to train the generated features again. Then, the generated features are input to the classifier. The proposed method is performed on three benchmark data sets referred as to AWA, CUB and SUN. The experimental results show that the proposed method achieves the state‐of‐the art classifier accuracy both in ZSL and GZSL settings. In ZSL setting, the classification accuracy of our method is superior to the compared algorithms, improved by 0.40% in AWA and 0.30% in SUN, respectively. And in GZSL setting, the classification accuracy of the method is superior to the comparison algorithm 0.41% in Harmonic mean on AWA, and 1.01%, 0.62%, and 1.05% in training data set, testing data set, and harmonic average on SUN.

BackgroundIntussusception is a prevalent pediatric issue causing acute abdominal pain, with potential links to rotavirus vaccines. The variety of these vaccines has grown in recent years. This meta-analysis study aims to evaluate the impact of various rotavirus vaccines on intussusception incidence.MethodsWe executed a thorough search across databases like PubMed, Cochrane Library, Embase, and Web of Science, leading to the selection of 15 credible randomized controlled trials (RCTs) that encompass various types of rotavirus vaccines. From each study, we extracted essential details such as vaccine types and intussusception occurrences. We assessed the risk of bias using the Cochrane Collaboration's tool, conducted statistical analysis with R (version 4.2.3), determined relative risk (RR) using a random effects model, and performed a subgroup analysis for vaccines of differing brands and types.ResultsWe included 15 randomized controlled studies from various countries. While intussusception incidence differed between vaccinated and control groups, this difference was not statistically significant. The overall risk ratio (RR), calculated using a random effects model, was 0.81, with a 95% confidence interval of [0.53, 1.23]. This crossing 1 shows that vaccination didn't notably change disease risk. Additionally, the 0% group heterogeneity suggests consistency across studies, strengthening our conclusions. Subgroup analysis for different vaccine brands and types (RV1 (Rotarix, Rotavac, RV3-BB), RV3 (LLR3), RV5 (RotasiiL, RotaTeq), and RV6) showed no significant variation in intussusception incidence. Despite variations in RR among subgroups, these differences were not statistically significant (P > 0.05).ConclusionsOur study indicates that rotavirus vaccination does not significantly increase the incidence of intussusception. Despite varying impacts across different vaccine brands and types, these variations are insignificant. Given the substantial benefits outweighing the risks, promoting the use of newly developed rotavirus vaccines remains highly valuable.Systematic Review Registrationwww.crd.york.ac.uk/prospero/, Identifier CRD42023425279.

Coal–gangue sorting is a vital component of intelligent mine construction. As intelligent manufacturing continued to advance, data-driven coal–gangue recognition emerged as a prominent research topic. However, conventional data-driven methods for coal–gangue recognition heavily rely on expert-extracted features. The process of feature extraction is labor-intensive and significantly impacts the final outcome. Deep learning (DL) offers an effective approach to automatically extract features from raw data. Among the various DL techniques, convolutional neural networks (CNNs) have proven to be particularly effective. In this paper, we propose an intelligent method for recognizing coal–rock by fusing multiple preprocessing techniques applied to near-infrared spectra and employing dual attention. Initially, a signal-to-RGB image conversion method is applied to fuse three types of preprocessing data, namely first-order differential, second-order differential, and standard normal transform, into an RGB image representation. Subsequently, we propose a neural network model (CBAM-VIT) that integrates the convolutional block attention mechanism (CBAM) and Vision Transformer (VIT). When evaluated on the coal–rock dataset, this model achieves an accuracy of 98.5%, surpassing the performance of VIT (95.3%), VGG-16 (89%), and AlexNet (82%). The comparative results clearly demonstrate that the proposed coal–gangue recognition method yields significant improvements in classification outcomes.

This paper reports the synthesis of a novel quaternary surfactant containing a hydroxyethyl group (PFPE-C) and the surface properties of its aqueous solution (investigated by comparisons with two structurally similar chemicals, dodecyl-(2-hydroxyethyl)-dimethylammonium chloride (DHDAC) and PFPE-A). The minimum surface tension (γCMC) and critical micelle concentration (CMC) of the PFPE-C aqueous solution were 17.35 mN/m and 0.024 mmol/L, respectively. This study confirms that surfactants containing hydroxyethyl groups efficiently reduce the surface tension of aqueous solutions, and fluorocarbon surfactants exhibit better surface activity than ordinary hydrocarbon surfactants with similar structures. The micellization, aggregation, air-water interfacial adsorption, and wettability of PFPE-C aqueous solutions have been systematically investigated. Highly concentrated PFPE-C aqueous solutions exhibit good wettability on PTFE and paraffin films. Moreover, the aggregates of PFPE-C in the aqueous solution were clearly seen as vesicles on Cryo-TEM micrographs. Primary biodegradation results indicate that 19% of PFPC-C can be degraded within one week.

Fused LEO navigation systems have been proposed as a low-cost means of supplementing and backing up global navigation satellite system (GNSS) navigation services based on low-earth orbit (LEO) constellations, which means broadcasting navigation signals based on the spectrum and hardware of the currently planned communication constellation. In this paper, we introduce Doppler-aided positioning to fused LEO navigation systems, which can improve the positioning performance and availability of fused LEO navigation systems by addressing insufficient pseudorange measures caused by insufficient navigation resources or the early stages of system construction. Theoretical analysis and simulation results show that Doppler-aided positioning based on the weighted least squares (WLS) method can improve the positioning accuracy of pseudorange positioning and achieve 95% three-dimensional errors within 21 m, even if the number of pseudorange measurements is less than four. Therefore, Doppler-aided positioning can expand the application scenarios of independent navigation services for fused LEO navigation systems.

In the case of limited endurance of unmanned aerial vehicles (UAVs), in order to further improve UAV data collection efficiency, this paper puts forward EDC-UAVIIoT: an enhanced energy-efficient data collection optimization algorithm for UAV swarm in the intelligent Internet of Things. First of all, the algorithm optimizes the UAV cruise path through the intelligent Internet of Things routing mechanism, avoids the occurrence of data errors in the packet transmission process, and uses the end-to-end transmission error probability model. The error probability of data packets in the transmission process is calculated to improve the efficiency of data collection tasks and data throughput. Secondly, considering the relationship between energy harvesting and energy consumption balance, this paper uses semi-definite programming and a convex approximation algorithm to transform the non-convex optimization problem into a convex optimization problem and realize the mapping relationship between the UAV cluster node and the target node coordinates, which reduces the computational complexity. Finally, the simulation results show that the EDC-UAVIIoT algorithm is compared with other algorithms in network energy consumption, running time, network delay, and network throughput. The numerical values are increased by 7.03%, 10.16%, 12.39%, and 8.82%, respectively, thus verifying the effectiveness and stability of the proposed EDC-UAVIIoT algorithm.

Abstract Background Men who have sex with men (MSM) are an important HIV key population in China. However, HIV testing rates among MSM remain suboptimal. Digital crowdsourced media interventions may be a useful tool to reach this marginalized population. We define digital crowdsourced media as using social media, mobile phone applications, Internet, or other digital approaches to disseminate messages developed from crowdsourcing contests. The proposed cluster randomized controlled trial (RCT) study aims to assess the effectiveness of a digital crowdsourced intervention to increase HIV testing uptake and decrease risky sexual behaviors among Chinese MSM. Methods A two-arm, cluster-randomized controlled trial will be implemented in eleven cities (ten clusters) in Shandong Province, China. Targeted study participants will be 250 MSM per arm and 50 participants per cluster. MSM who are 18 years old or above, live in the study city, have not been tested for HIV in the past 3 months, are not living with HIV or have never been tested for HIV, and are willing to provide informed consent will be enrolled. Participants will be recruited through banner advertisements on Blued, the largest gay dating app in China, and in-person at community-based organizations (CBOs). The intervention includes a series of crowdsourced intervention materials (24 images and four short videos about HIV testing and safe sexual behaviors) and HIV self-test services provided by the study team. The intervention was developed through a series of participatory crowdsourcing contests before this study. The self-test kits will be sent to the participants in the intervention group at the 2nd and 3rd follow-ups. Participants will be followed up quarterly during the 12-month period. The primary outcome will be self-reported HIV testing uptake at 12 months. Secondary outcomes will include changes in condomless sex, self-test efficacy, social network engagement, HIV testing social norms, and testing stigma. Discussion Innovative approaches to HIV testing among marginalized population are urgently needed. Through this cluster randomized controlled trial, we will evaluate the effectiveness of a digital crowdsourced intervention, improving HIV testing uptake among MSM and providing a resource in related public health fields. Trial registration ChiCTR1900024350 . Registered on 6 July 2019.

A reinforcement learning-based continuous action space path planning method for mobile robots is proposed in this article. First, the kinematic model of the mobile robot is analyzed, and on this basis, the optimal state space is constructed according to the minimum depth of the field value in the depth image to characterize the distance between the robot and the obstacle. Then, by setting the reward function of the mobile robot based on the artificial potential field method, the information of the robot’s distance from obstacles is continuous, and a new reinforcement learning training process is proposed. Finally, by introducing a DDPG algorithm, the path planning of a mobile robot in an unknown environment is described as a Markov decision process, and the optimal planning of the mobile robot’s continuous action space path is realized with a high success rate. The results show that compared with other three comparison methods, the final success rates of the proposed method are the highest, which are 97.2%, 99.1%, 98.4%, and 98.6%, respectively.

Remdesivir has displayed pharmacological activity against SARS-CoV-2. However, no pharmacometabolomics (PM) or correlation analysis with pharmacokinetics (PK) was revealed. Rats were intravenously administered remdesivir, and a series of blood samples were collected before and after treatment. Comprehensive metabolomics profile and PK were investigated and quantitated simultaneously using our previous reliable HPLC-MS/MS method. Both longitudinal and transversal metabolic analyses were conducted, and the correlation between PM and PK parameters was evaluated using Pearson’s correlation analysis and the PLS model. Multivariate statistical analysis was employed for discovering candidate biomarkers which predicted drug exposure or toxicity of remdesivir. The prominent metabolic profile variation was observed between pre- and posttreatment, and significant changes were found in 65 metabolites. A total of 15 metabolites—12 carnitines, one N-acetyl-D-glucosamine, one allantoin, and one corticosterone—were significantly correlated with the concentration of Nuc (active metabolite of remdesivir). Adenosine, spermine, guanosine, sn-glycero-3-phosphocholine, and l-homoserine may be considered potential biomarkers for predicting drug exposure or toxicity. This study is the first attempt to apply PM and PK to study remdesivir response/toxicity, and the identified candidate biomarkers might be used to predict the AUC and Cmax, indicating capability of discriminating good or poor responders. Currently, this study originally offers considerable evidence to metabolite reprogramming of remdesivir and sheds light on precision therapy development in fighting COVID-19.

To seek effective ways of lowering development cost and tapping inter-well remaining reserves, sidetracking horizontal wells from old wells in Su10 and Su53 Block were conducted. The engineering and geological problems such as leakage, collapse and sticking in slim-hole sidetracking, and difficult evaluation of remaining gas were gradually overcome, and a set of drilling and completion technology, well deployment optimization technology and geo-steering technology suitable for sidetracking horizontal wells in tight sandstone gas reservoirs have been worked out. By making full use of the old well, sidetracking horizontal wells can greatly reduce development costs, enhance the producing degree of inter-well remaining reserves, and get production 3-5 times of that of adjacent vertical wells. Its production effect is influenced by encountered sandstone length, the position of the horizontal segment in the reservoir, produced effective reservoir thickness, gas saturation, controlled reserves and fracturing effect, etc. Up to now, in Block Su10 and Su53, 12 sidetracking horizontal wells have been drilled, which have an average drilling cycle of 49 days, average horizontal section length of 689 m, average effective drilling ratio of 61.5%, average well-head pressure of 16.2 MPa, and daily output of 4.7×104 m3 at the initial stage after production. By the end of 2017, the average yield increment was more than 1 000×104 m3 with good effect. With the increase of low yield old wells, wells in the enrichment regions tend to be saturated and the rest gas-bearing areas are lower in grade, therefore, sidetracking horizontal well can be used for optimization of well pattern, well deployment mode and exploitation of remaining oil areas. Key Words: Sulige Gas Field, sidetracking horizontal well, tight sandstone, old well stimulation, reserves producing

Low Earth Orbit (LEO) satellites have stronger received signals and more rapid geometry changes than Global Navigation Satellite System (GNSS) satellites, making them attractive for positioning, navigation, and timing (PNT) applications. Due to the low altitude, the LEO constellation requires more satellites to cover the entire globe and more Pseudo Random Noise (PRN) codes to realize Code Division Multiple Access (CDMA), which means greater receiver storage resources and receiver acquisition time. In this paper, different from the traditional methods that assign a unique PRN code to each satellite, we propose a novel method in which several satellites share the same PRN code, and simply demonstrate the feasibility and benefits of this method. To determine the minimum number of PRN codes needed for a constellation, we build a mathematical model. After the algorithm comparison, we improve the recursive largest first (RLF) algorithm so that it has a higher running speed and a smaller approximate optimal solution within a certain time period. By studying polar-orbiting and walker constellations, we find that if other satellite parameters remain the same, the higher the orbital altitude is, the more PRN codes are needed, and no matter what the orbital inclination is, the minimum number of PRN codes remains the same. Overall, it is feasible and meaningful for several satellites sharing the same PRN code to save storage resources and reduce the satellite acquisition time of the receiver. If this new technology is applied, the storage resources and the average satellite acquisition time of the receiver will be, at most, one-third of previous ones.

Fatty liver hemorrhage syndrome (FLHS) in chickens is characterized by steatosis and bleeding in the liver, which has caused huge losses to the poultry industry. This study aimed to use primary cultured broiler hepatocytes to establish a steatosis model to explore the optimal conditions for inducing steatosis by incubating the cells with a fat emulsion. Primary hepatocytes were isolated from an AA broiler by a modified two-step in situ perfusion method. Hepatocytes were divided into an untreated control group and a fat emulsion group that was incubated with 2.5, 5, 10, or 20% fat emulsion for different times to determine the optimal conditions for inducing steatosis of primary hepatocytes. Incubation of the cells with 10% fat emulsion resulted in cell viability at 48 h of 67%, which was higher than the control group and met the requirements of the model. In the second experiment, steatosis was induced by incubating hepatocytes with 10% fat emulsion for 48 h. In consequence, the apoptosis rate decreased (p > 0.05) and the concentration of ALT (p < 0.001), AST (p < 0.01), and TG (p < 0.05) increased significantly; the expression level of SREBP-1c (p < 0.05) increased, and the expression levels of PPARα (p < 0.001), CPT1 (p < 0.001), and CPT2 (p < 0.05) were lower in the fat emulsion group than in the control group. In conclusion, the induction condition was selected as 10% fat emulsion incubation for 48 h, and we successfully established a fatty liver degeneration model for broilers.

Poly l-lactic acid (PLLA) was limited in the further orthopaedic application due to its insufficient mechanical property and poor bioactivity. Graphene oxide (GO) is an effective reinforcement, whereas silicon-doped hydroxyapatite (Si-HA) possesses excellent bioactivity, but either GO or Si-HA tends to aggregate in PLLA matrix. In this study, a GO@Si-HA nanosystem was achieved by in-situ growth of Si-HA on GO, and then incorporated into PLLA scaffold fabricated by laser sintering technology. On one hand, Si-HA on the surface of GO effectively prevented the aggregation of GO by acting as a barrier between GO nanosheets. On the other hand, GO hindered the aggregation of Si-HA by means of anchoring Si-HA. Results displayed that the compressive strength and modulus of the PLLA/GO@Si-HA composite scaffold were enhanced by 85% and 120%, respectively. Meanwhile, the scaffold exhibited significantly improved bioactivity, and consequently promoted cell adhesion, proliferation and differentiation. The developed PLLA/GO@Si-HA composite scaffold with excellent mechanical properties and superior bioactivity could serve as a promising substitute for bone repairing.

In this study, the manoeuvering target tracking problem is addressed by using the unbiased converted measurements from a two-dimensional radar system. Due to the fact that radar measurements are usually expressed in polar coordinates while the target motion is described in the Cartesian coordinates, the unbiased converted measurements are utilised to linearise the system model of the manoeuvering target tracking problem in the Cartesian coordinates. The manoeuver acceleration is modelled as the unknown input of the constant velocity kinematic model of the target. First, it is pointed out that the converted measurement noise no longer satisfies Gaussian distribution, even if the raw radar measurement noise is Gaussian noise. In order to solve the manoeuvering target tracking problem with non-Gaussian disturbances, a joint estimation method for the target state and the unknown input is presented under the maximum correntropy criterion. In the simulation, the proposed manoeuvering target tracking method is compared with the one developed on the basis of the traditional Kalman filter. The simulation results verify the effectiveness of the method proposed in this study.

Polyvinylidene fluoride (PVDF), as a typical piezoelectric polymer, has a great potential in reconstructing the electrical microenvironment of bone tissue. In present study, graphene oxide (GO) was introduced into PVDF scaffold manufactured via selective laser sintering, aiming to enhance piezoelectric effect of PVDF by increasing β phase content. In detail, the oxygen-containing functional groups of GO could form strong hydrogen bonding with fluorine groups of PVDF. The interaction would force the fluorine groups to be arranged in parallel and perpendicular to the polymer chain, thereby inducing the transformation from α phase to β phase. Results demonstrated that the PVDF/0.3GO scaffold with improved β phase exhibited the maximal output voltage (~8.2 V) and current (~101.6 nA), which were improved by 82.2% and 68.2%, respectively, in comparison with pure PVDF. In vitro cell culture confirmed that enhanced electrical charges could significantly improve cell behavior. Moreover, the scaffold presented a 97.9% increase in compressive strength and 24.5% increase in tensile strength, which was attributed to GO reinforcements forming strong interaction with PVDF chains. These positive results suggested that the scaffold might have possible application in bone tissue engineering. Keywords: Bone regeneration, Piezoelectric, Polyvinylidene fluoride, Graphene oxide, Selective laser sintering

Based on drilling and production test data and the geological, geochemical, geophysical and rock mechanics achievements of Weiyuan Block of Sichuan Basin, “sweet spots” of shale gas were determined and geosteering technology was tested in drilling the sweet spots under complex structural background. The high quality Silurian Longmaxi Formation shale (with TOC≥2%) in the study area, thick (36.0−44.5 meters), is divided into four sublayers, from bottom to top, which differ widely in TOC (2.0%−8.1%), gas content (1.2−12.6 m3/t), porosity (0.66%−11.80%), and brittle mineral content (17.5%−98.5%). Considering gas content and fracability of shale, the layer Long 11a in Longmaxi Formation is the best “sweet spot” layer in vertical direction; horizontally, the areas with folding structure in shale reservoir have more natural fractures, and thus have better storage quality and permeability, are “sweet spots”. During drilling of the sweet spots, three-dimensional seismic and geological modeling was used to predict the depth of “sweet spot”, which was corrected in time with drilling data, and by controlling well trajectory this way, the drilling rate of “sweet spots” has been improved. Key words: Sichuan Basin, Weiyuan Block, Silurian Longmaxi Formation, shale gas, high quality shale, sweet spot, geosteering technology in drilling

Poly‑l‑lactic acid (PLLA) is a promising bone repair material because of its good biocompatibility and natural degradability. Nevertheless, the poor mechanical properties and local inflammatory response limits its further application in bone repair. In this research, nano magnesium oxide (nMgO) was incorporated into PLLA scaffold manufactured by selective laser sintering technique. Results shown that nMgO with good affinity to PLLA could act as nucleating agent during crystallization process and effectively enhance the crystallinity of PLLA, which was proved by the isothermal behavior and non-isothermal behavior analysis. The evolution of crystallization was also achieved by polarized optical microscopy. Mechanical tests confirmed that the tensile strength, young modulus and Vickers hardness of PLLA/3nMgO was enhanced by 38%, 24% and 11%, respectively, as compared with PLLA. On the other hand, the incorporated nMgO neutralized the acid degradation by-products of PLLA, forming a weak alkaline environment which might contribute to avoiding sever local inflammation after implantation. Moreover, in vitro cell culture revealed an improved biocompatibility of PLLA/nMgO scaffolds. All these positive results suggested that PLLA/3nMgO scaffold was a potential material for bone repair application. Keywords: PLLA, Bone scaffolds, Mechanical properties, Degradation behavior, Biocompability

Poly-L-Lactic Acid (PLLA) is a bioabsorbable implant material due to its favorable biocompatibility and inherent degradability, while the insufficient mechanical strength hinders its further bone repair application. In present work, carbon nanotubes (CNTs) were introduced into PLLA scaffolds fabricated via selective laser sintering. It was found that the crystallinity of PLLA increased considerably since CNTs could promote the orderly stacking of its molecular chains, thereby improving the mechanical strength of PLLA scaffold. Furthermore, the fracture surface analysis revealed that CNTs acted as a bridge across the cracks and hindered their further expansion. Moreover, CNTs pulled out from the matrix to consume a large amount of fracture energy, which enhanced the resistance to external forces. As a consequence, the compressive strength, Vickers hardness and tensile strength of the scaffold were enhanced by 22.7%, 58.8% and 17.6%, respectively. Besides, the cells exhibited good attachment, spreading and proliferation on the scaffold. This study demonstrated that PLLA/CNTs scaffold was a promising candidate as bone implant.

This paper describes the physical model of a multi-stage fractured horizontal well in tight reservoirs. Moreover, a composite zonal productivity prediction model of staged multi-cluster fracturing horizontal well was established. The inner area of the model is a dual porosity model composed of matrix and micro-fracture network formed by the artificial fracture and natural fractures opened by fracturing treatment, and the outer region is a single matrix. The effects of threshold pressure gradient, stress-sensitive matrix permeability, capillary pressure, and the conductivity failure capacity of artificial fractures in the production forecast are fully considered in the model. The influence of different clusters, different fracturing stages, half-length of fractures, and permeability of the micro-fractures on the oil drainage area of the horizontal well was analyzed via numerical simulation. The influencing factors of different well patterns and drainage area of multi-stage fractured horizontal well were also studied. The method of using drainage radius of multi-stage fractured horizontal well and the technical countermeasures to improve the well productivity are instructive for the development of tight oil reservoirs.

In order to ensure the safety of chemical plants, this paper analyzes the image and numerical simulation technology applied by chemical plants to position the fire source and carry out the fire protection. Actual researches and simulation computation are used in the analysis. The fire source position strategy for chemical plants based on image and numerical simulation technology is obtained. The image and numerical simulation technology can effectively manage fire spread, crowd evacuation and smoke control in fire.

Migrant men who have sex with men (MSM) have a higher predisposition for HIV transmission. We aimed to determine and compare the prevalence and trends of HIV, Syphilis, and HCV between migrant and resident MSM in Shandong, China.A serial cross-sectional study was conducted in eight cities in Shandong, China from 2010 to 2014. The surveys collected information on demographics, HIV-related knowledge, and HIV-related behaviors including the serologic status of HIV, syphilis, and HCV. Bivariate and multivariable logistic regressions were used to determine differences between migrant and resident MSM.The overall prevalence of HIV among the 15,705 MSM (14120 were resident, 1580 were migrant and 5 were missing) was 2.6%, with an increase of 1.0% in 2010 to 4.4% in 2014. Prevalence of HIV was higher among migrant MSMs (5.5%) compared to resident MSMs (2.3%). Compared to residents, migrants also had higher prevalence of syphilis (7.5% vs 4.9%) and HCV (1.1% vs 0.6%). We found that there was an increase in the proportion of migrant MSM engaging in anal sex [adjusted OR (AOR) = 1.41 in migrants vs 1.12 in residents], condom use during last anal sex (AOR = 1.14 in residents, P for trend = 0.32), consistent condom use (AOR = 1.04 residents, P for trend = 0.11) and drug use (AOR = 1.51 in migrants and 1.29 among residents). Except in the year 2011, receiving some health services in last year was significant for people who were HIV-positive compared to negative. (P for trend

Strain-hardening and warm deformation behaviors of extruded Mg–2Sn–0.5Yb alloy (at.%) sheet were investigated in uniaxial tensile test at temperatures of 25–250 °C and strain rates of 1 × 10−3 s−1–0.1 s−1. The data fit with the Kocks–Mecking type plots were used to show different stages of strain hardening. Besides III-stage and IV-stage, the absence of the II-stage strain hardening at room temperature should be related to the sufficient dynamic recrystallization during extrusion. The decrease of strain hardening ability of the alloy after yielding was attributed to the reduction of dislocation density with increasing testing temperature. Strain rate sensitivity (SRS) was significantly enhanced with increasing temperature, and the corresponding m-value was calculated as 0.07–0.12, which indicated that the deformation mechanism was dominated by the climb-controlled dislocation creep at 200 °C. Furthermore, the grain boundary sliding (GBS) was activated at 250 °C, which contributed to the higher SRS. The activation energy was calculated as 213.67 kJ mol−1, which was higher than that of lattice diffusion or grain boundary self-diffusion. In addition, the alloy exhibited a quasi superplasticity at 250 °C with a strain rate of 1 × 10−3 s−1, which was mainly related to the fine microstructure and the presence of the Mg2Sn and Mg2(Sn,Yb) particles.

Perfluoropolyether (PFPE) glycerol emulsions were prepared. Three different green surfactants (AES (sodium laureth sulfate), APG (alkyl polyglycoside), and SDS (sodium dodecyl sulfate)) were chosen to emulsify the PFPE. Their properties and performance in shampoo were also investigated. Centrifuge stability measurements show that three PFPE emulsions have good stability. They are stable for 60 min when the centrifugal speed is 6000 r/min. In addition, a change of droplet size was observed with time. Moreover, its rheological properties and application performance was studied. The AES emulsion was the most stable emulsion and it was found to improve the slip and lubricity performance of the cotton, so it has potential applications in shampoo.

This paper is concerned to the fire localization problem for large-space buildings. Two kinds of circular fire source arrangement localization methods are proposed on the basis of the dynamic optimization technology. In the Range-Point-Range frame, a dynamic optimization localization is proposed to globally estimate the circle center of the circular arrangement to be determined based on all the point estimates of the fire source. In the Range-Range-Range frame, a dynamic optimization localization method is developed by solving a non-convex optimization problem. In this way, the circle center and the radius are obtained simultaneously. Additionally, the dynamic angle bisector method is evaluated. Finally, a simulation with three simulation scenes is provided to illustrate the effectiveness and availability of the proposed methods.

BACKGROUND:The availability of oral fluid HIV rapid testing provides an approach that may have the potential to expand HIV testing in China, especially among most-a-risk populations. There are few investigations about the acceptability of oral fluid HIV testing among most-at-risk populations in China. METHOD:A cross-sectional study with men who have sex with men (MSM), female sex workers (FSW) and voluntary counseling and testing (VCT) clients was conducted in three cities of Shandong province, China from 2011 to 2012. Data were collected by face-to-face questionnaire. RESULTS:About 71% of participants were willing to accept the oral fluid HIV rapid testing, and home HIV testing was independently associated with acceptability of the new testing method among MSM, FSW and VCT clients (AOR of 4.46, 3.19 and 5.74, respectively). Independent predictors of oral fluid HIV rapid testing acceptability among MSM were having ever taken an oral fluid HIV rapid test (AOR= 15.25), having ever taken an HIV test (AOR= 2.07), and education level (AOR= 1.74). Engagement in HIV-related risk behaviors (AOR= 1.68) was an independent predictor of acceptability for FSW. Having taken an HIV test (AOR= 2.85) was an independent predictor of acceptability for VCT clients. The primary concern about the oral fluid HIV testing was accuracy. The median price they would pay for the testing ranged from 4.8 to 8.1 U.S. dollars. CONCLUSION:High acceptability of oral fluid HIV rapid testing was shown among most-at-risk populations. Findings provide support for oral rapid HIV testing as another HIV prevention tool, and provide a backdrop for the implementation of HIV home testing in the near future. Appropriate pricing and increased public education through awareness campaigns that address concerns about the accuracy and safety of the oral fluid HIV rapid testing may help increase acceptability and use among most-at-risk populations in China.

Abstract This study’s objective was to assess the social skills, peer acceptance, and friendship among students involved in bullying situations transitioning from elementary to middle school. A total of 408 6th grade students from six public schools in the interior of São Paulo, Brazil composed the sample; 54.9% of whom were aged 11.3 years on average (Standard Deviation = 0.6). Data were analyzed using Analysis of Variance and Spearman’s correlation. In regard to social skills, bully-victims present a greater amount of passive and active responses when compared to victims, bullies, and not involved students. Only male bully-victims, however, experienced significantly more frequent rejection by peers, while female bully-victims had significantly fewer friends. The results indicate the need to develop interventions intended to prevent and decrease bullying in the period of school transition. Such interventions should, however, be gender-sensitive because of differences existing between boys and girls.