Application of improved Jellyfish search algorithm for 9-parameters cell extraction and GMPPT in PV systems.

Optimization algorithms are essential tools used to address real-world problems through minimization or maximization processes. In the context of photovoltaic (PV) systems, various optimization algorithms have been employed to extract solar cell parameters using minimization techniques, and to identify the maximum power point (MPP) using maximization approaches. However, under partial shading conditions or during rapidly changing irradiance, many of these algorithms tend to get trapped in local minima, failing to locate the global maximum power point (GMPPT). This shortcoming leads to significant energy losses from PV cells. Similarly, the extraction of solar cell parameters is often compromised by the random search behavior and inadequate exploration and exploitation capabilities of many existing algorithms. The Jellyfish Search Optimization (JSO) algorithm is a recent, parameter-free method developed to tackle a wide range of optimization problems. Despite its innovative design, JSO is prone to premature convergence and exhibits a longer convergence time. To address these limitations, this paper proposes a modified version of the JSO algorithm, which integrates the state-of-the-art features of JSO with the Lévy flight characteristic from the cuckoo search algorithm. This combination aims to achieve a better balance between exploration and exploitation. To validate the effectiveness of the proposed Improved Jellyfish Search Optimization (IJSO) algorithm in PV systems, extensive experiments were conducted. These experiments included benchmarking with complex test functions, extracting cell parameters using various solar cell models, and maximizing energy output from PV systems under different environmental conditions. The results demonstrate that the proposed IJSO algorithm effectively enhances parameter extraction and global maximum power point tracking, making it a promising solution for optimizing energy extraction from PV cells in dynamic conditions.

Improving the Cycle Stability of LiNiO2 through Al3+ Doping and LiAlO2 Coating.

In this study, we addressed the poor cycling and rate performance of LiNiO2, a material with ultrahigh nickel content considered a strong contender for high-energy-density lithium-ion battery cathodes. We introduced nano-Al2O3 during the lithiation process to achieve dual modified material through bulk phase element doping and in situ LiAlO2 coating. Comparison revealed notable improvements in the modified materials. In particular, LiNi0.99Al0.01O2 maintained a capacity retention rate of 73.1% after 300 cycles in a long-cycle test at 0.5C current density, outperforming the undoped material. In rate performance tests, the doped samples consistently exhibited higher discharge-specific capacities than that of the undoped counterpart. Notably, at a high current density of 5C, LiNi0.99Al0.01O2 exhibited a discharge-specific capacity of 101.75 mAh g-1. The results indicate that an appropriate amount of Al doping can effectively stabilize the layered structure of the cathode material and delay the irreversible phase transition from H2 to H3. Further, Al doping facilitates the formation of a LiAlO2 coating on the surface of the particles. This coating acts as a fast-ion conductor, enhancing the transport of lithium ions and reducing the erosion of the active material by the electrolyte.

Ball-Milling-Assisted N/O Codoping for Enhanced Sodium Storage Performance of Coconut-Shell-Derived Hard Carbon Anodes in Sodium-Ion Batteries.

Sodium-ion batteries (SIBs) are regarded as cost-effective alternatives or competitors to lithium-ion batteries for large-scale electric energy storage applications. However, their development has been hindered by the high cost of hard carbon (HC) anodes and poor electrochemical performance. To enhance the sodium storage capacity and rate performance of HC, this study accelerated the electrochemical performance of coconut-shell-derived HC anodes for SIBs through N/O codoping using ball milling and pyrolysis. Experimental results demonstrate that the simultaneous introduction of N and O generates a synergistic effect, increasing the surface oxygen-containing functional groups, defects, and interlayer spacing of coconut-shell-derived HC through the codoping of light elements. The excellent strategy has increased the slope capacity and platform capacity of HC, and the synergistic modification of N/O has increased its reversible specific capacity from 272 to 343 mA h g-1 (30 mA g-1), with a retention rate of approximately 92.1% after 100 cycles. In addition, it also exhibits an excellent rate performance, reaching 178 mA h g-1 at 1500 mA g-1. In summary, this study presents an effective strategy for modifying biomass-derived HC.

Changes in the Epidemiological Features of Influenza After the COVID-19 Pandemic in China, the United States, and Australia: Updated Surveillance Data for Influenza Activity.

BACKGROUND: There has been a global decrease in seasonal influenza activity since the onset of the COVID-19 pandemic. OBJECTIVE: We aimed to describe influenza activity during the 2021/2022 season and compare it to the trends from 2012 to 2023. We also explored the influence of social and public health prevention measures during the COVID-19 pandemic on influenza activity. METHODS: We obtained influenza data from January 1, 2012, to February 5, 2023, from publicly available platforms for China, the United States, and Australia. Mitigation measures were evaluated per the stringency index, a composite index with 9 measures. A general additive model was used to assess the stringency index and the influenza positivity rate correlation, and the deviance explained was calculated. RESULTS: We used over 200,000 influenza surveillance data. Influenza activity remained low in the United States and Australia during the 2021/2022 season. However, it increased in the United States with a positive rate of 26.2% in the 49th week of 2022. During the 2021/2022 season, influenza activity significantly increased compared with the previous year in southern and northern China, with peak positivity rates of 28.1% and 35.1% in the second week of 2022, respectively. After the COVID-19 pandemic, the dominant influenza virus genotype in China was type B/Victoria, during the 2021/2022 season, and accounted for >98% (24,541/24,908 in the South and 20,543/20,634 in the North) of all cases. Influenza virus type B/Yamagata was not detected in all these areas after the COVID-19 pandemic. Several measures individually significantly influence local influenza activity, except for influenza type B in Australia. When combined with all the measures, the deviance explained values for influenza A and B were 87.4% (P<.05 for measures of close public transport and restrictions on international travel) and 77.6% in southern China and 83.4% (P<.05 for measures of school closing and close public transport) and 81.4% in northern China, respectively. In the United States, the association was relatively stronger, with deviance-explained values of 98.6% for influenza A and 99.1% (P<.05 for measures of restrictions on international travel and public information campaign) for influenza B. There were no discernible effects on influenza B activity in Australia between 2020 and 2022 due to the incredibly low positive rate of influenza B. Additionally, the deviance explained values were 95.8% (P<.05 for measures of restrictions on gathering size and restrictions on international travel) for influenza A and 72.7% for influenza B. CONCLUSIONS: Influenza activity has increased gradually since 2021. Mitigation measures for COVID-19 showed correlations with influenza activity, mainly driven by the early stage of the pandemic. During late 2021 and 2022, the influence of mitigation management for COVID-19 seemingly decreased gradually, as the activity of influenza increased compared to the 2020/2021 season.

Mapping the Characteristics of Respiratory Infectious Disease Epidemics in China Based on the Baidu Index from November 2022 to January 2023.

Introduction: Infectious diseases pose a significant global health and economic burden, underscoring the critical need for precise predictive models. The Baidu index provides enhanced real-time surveillance capabilities that augment traditional systems. Methods: Baidu search engine data on the keyword "fever" were extracted from 255 cities in China from November 2022 to January 2023. Onset and peak dates for influenza epidemics were identified by testing various criteria that combined thresholds and consecutive days. Results: The most effective scenario for indicating epidemic commencement involved a 90th percentile threshold exceeded for seven consecutive days, minimizing false starts. Peak detection was optimized using a 7-day moving average, balancing stability and precision. Discussion: The use of internet search data, such as the Baidu index, significantly improves the timeliness and accuracy of disease surveillance models. This innovative approach supports faster public health interventions and demonstrates its potential for enhancing epidemic monitoring and response efforts.

A high-quality genome assembly of the shrubby cinquefoil (Dasiphora fruticosa).

Dasiphora fruticosa (Rosaceae), commonly known as shrubby cinquefoil, is a flowering shrub of high ornamental value yet underutilized in East Asian landscapes. Given its broad elevational distribution range, D. fruticosa serves as an ideal model for studying genetic adaptations and speciation along elevation gradients. Here, we present a high-quality chromosome-scale assembly of D. fruticosa with a genome size of 249.23 Mb and a contig N50 length of 14.01 Mb. The genome sequence contains 32,613 protein-coding genes, of which 30,643 (93.96%) were functionally annotated. Compared to the published D. fruticosa genome sequence, our assembly demonstrates higher completeness and continuity. Furthermore, comparative genomic analyses provide insights into the phylogenetic relationship and high-altitude adaptation of D. fruticosa. Overall, our study offers a valuable genetic resource for both molecular and evolutionary research on shrubby cinquefoil.

Investigation on the solidification effect and mechanism of loess utilizing magnesium oxysulfate cement as a curing agent.

In this study, magnesium oxysulfate cement (MOS) was used as a binder for curing loess. The changes in bulk density, porosity, mineral structure and microstructure of the consolidated loess were systematically studied and verified. The porosity decreased from 40.97 % in pure loess to 28.75 % in 13 % MOS solidified sample. Scanning electron microscopy, energy spectrum analysis and thermogravimetric analysis revealed that the addition of MOS binder resulted in the formation of hydrated products, including Mg(OH)2, MgO·mSiO2·nH2O (M-S-H), and 3Mg(OH)2·MgSO4·8H2O (3·1·8 phase), which effectively filled the voids between the grains and facilitated strong bonding among them. After a curing period of 28 days, the compressive strength of loess stabilized with 13 % MOS exhibited an increase to 7.9 MPa. Moreover, following immersion in water for 24 h, the softening coefficient K remained at 0.66. Furthermore, after undergoing five cycles of freeze-thaw cycling, the rate of change in compressive strength RP was only 6.3 %. All the results indicate that MOS exhibits promising potential as a binder for soil stabilization applications.

Development of SSR Markers and Evaluation of Genetic Diversity of Endangered Plant Saussurea involucrata.

The conservation biology field underscores the importance of understanding genetic diversity and gene flow within plant populations and the factors that influence them. This study employs Simple Sequence Repeat (SSR) molecular markers to investigate the genetic diversity of the endangered plant species Saussurea involucrata, offering a theoretical foundation for its conservation efforts. Utilizing sequencing results to screen SSR loci, we designed and scrutinized 18 polymorphic microsatellite primers across 112 samples from 11 populations in the Bayinbuluke region. Our findings reveal high genetic diversity (I = 0.837, He = 0.470) and substantial gene flow (Nm = 1.390) among S. involucrata populations (China, Xinjiang), potentially attributed to efficient pollen and seed dispersal mechanisms. Principal Coordinate Analysis (PCoA) indicates a lack of distinct genetic structuring within the Bayinbuluke populations. The cluster analysis using STRUCTURE reflected the genetic structure of S. involucrata to a certain extent compared with PCoA. The results showed that all samples were divided into four groups. To safeguard this species, we advocate for the in situ conservation of all S. involucrata populations in the area. The SSR markers developed in this study provide a valuable resource for future genetic research on S. involucrata.

Analysis of the 5' Untranslated Region Length-Dependent Control of Gene Expression in Maize: A Case Study with the ZmLAZ1 Gene Family.

The untranslated regions (UTRs) within plant mRNAs play crucial roles in regulating gene expression and the functionality of post-translationally modified proteins by various mechanisms. These regions are vital for plants' ability to sense to multiple developmental and environmental stimuli. In this study, we conducted a genome-wide analysis of UTRs and UTR-containing genes in maize (Zea mays). Using the ZmLAZ1 family as a case study, we demonstrated that the length of 5' UTRs could influence gene expression levels by employing GUS reporter gene assays. Although maize and arabidopsis (Arabidopsis thaliana), as well as rice (Oryza sativa), have distinct functional categories of UTR-containing genes, we observed a similar lengthwise distribution of UTRs and a recurring appearance of certain gene ontology (GO) terms between maize and rice. These suggest a potentially conserved mechanism within the Poaceae species. Furthermore, the analysis of cis-acting elements in these 5' UTRs of the ZmLAZ1 gene family further supports the hypothesis that UTRs confer functional specificity to genes in a length-dependent manner. Our findings offer novel insights into the role of UTRs in maize, contributing to the broader understanding of gene expression regulation in plants.

Morphological, Physiological, and Photosynthetic Differences of Tartary Buckwheat Induced by Post-Anthesis Drought.

Tartary buckwheat (Fagopyrum tataricum (L.) Gaertn) is a crop of significant interest due to its nutritional value and resilience to drought conditions. However, drought, particularly following flowering, is a major factor contributing to yield reduction. This research employed two distinct Tartary buckwheat genotypes to investigate the effects of post-anthesis drought on growth and physicochemical characteristics. The study aimed to elucidate the response of Tartary buckwheat to drought stress. The findings indicated that post-anthesis drought adversely impacted the growth, morphology, and biomass accumulation of Tartary buckwheat. Drought stress enhanced the maximum photosynthetic capacity (Fv/Fm) and light protection ability (NPQ) of the 'Xiqiao-2' genotype. In response to drought stress, 'Dingku-1' and 'Xiqiao-2' maintained osmotic balance by accumulating soluble sugars and proline, respectively. Notably, 'Xiqiao-2' exhibited elevated levels of flavonoids and polyphenols in its leaves, which helped mitigate oxidative damage caused by drought. Furthermore, rewatering after a brief drought period significantly improved plant height, stem diameter, and biomass accumulation in 'Dingku-1'. Overall, 'Xiqiao-2' demonstrated greater long-term tolerance to post-anthesis drought, while 'Dingku-1' was less adversely affected by short-term post-anthesis drought.

Impact of different concentration iodinated contrast media on pain and comfort in abdominal computed tomography.

OBJECTIVES: To investigate whether high concentration iodinated contrast media (CM), compared with low concentration CM, could reduce pain and discomfort levels in patients who had level II and III venous conditions. METHODS: This prospective, single-center study enrolled patients who had level II and III venous conditions and underwent abdominal contrast-enhanced CT scan between July 2021 and February 2022. The venous condition to establish peripheral venous access for CM injection was graded using the Intravenous Access Scoring system, of which level II and III indicated poor venous condition and difficult venous access. Patients received iomeprol 400 in high concentration group and ioversol 320 in low group at an identical iodine delivery rate of 1.12 gI/s. The primary outcomes were pain and comfort levels. The secondary outcomes included adverse events and image quality. Patients rated pain intensity via Numerical Rating Scale and comfort level via Visual Analogue Scale with higher scores indicating higher levels of pain and discomfort. Quantitative and qualitative image assessment were compared between two groups. Continuous variables were compared using Student's t test or Mann-Whitney U test. Categorical variables were compared using χ2 test, χ2 test for trend or Fisher's exact test. RESULTS: A total of 206 patients (mean age, 60.13 ± 12.14 years; 81 males) were included with 99 in the high concentration group and 107 in the low concentration group. The high group had significantly lower pain scores (median 1 [IQR: 0-2] vs 2 (IQR 2-4), p < 0.001) and comfort scores (1 [IQR: 0-3] vs 3 [IQR: 2-5], p < 0.001) than the low group. Incidence of CM extravasation did not significantly differ (1.0 % vs 4.5 %, p = 0.214). No hypersensitivity reaction was observed. Qualitative assessment showed higher clarity scores of intrahepatic hepatic artery and portal vein in the high group. Quantitative assessment results were comparable between two groups. CONCLUSION: High concentration iodinated CM could lower pain intensity and improve comfort levels without comprising image quality of CT scan. High concentration CM is a preferable choice in patients with poor venous conditions during contrast-enhanced CT scan.

Pathogen characteristics of respiratory infections in the season after the COVID-19 pandemic between August and December 2023: evidence from direct-to-consumer testing-based surveillance in Guangzhou and Beijing, China.

OBJECTIVES: In the fall-winter of 2023, China experienced its first epidemic season of respiratory diseases since the COVID-19 pandemic. Gathering timely data about pathogenetic characteristics of respiratory infections is crucial to complement current respiratory surveillance mechanisms in China. Data from direct-to-consumer (DTC) multi-respiratory pathogen (MRP) testing could serve as a novel source of multi-pathogen data for community-based surveillance. METHODS: A pioneering initiative was launched to detect multiple respiratory pathogens in Beijing and Guangzhou, China. DTC MRP tests were used to provide proactive surveillance ahead of medical services. RESULTS: A total of 28,018 participants were enrolled between 22 August and 10 December 2023. Positive findings for at least one respiratory pathogen were observed in 26,202 (93.5%) participants. Influenza virus A, respiratory syncytial virus (RSV), and human adenovirus are the three leading viral pathogens detected with proportions of 18.0%, 10.6%, and 8.8%. Viral-bacterial pathogens were co-detected in 9736 (34.7%) of participants, which reduced to 22.2% for bacterial-bacterial co-detection, and 22.0% for bacterial mono-detection. The epidemiological ecology of respiratory pathogens within both viral clusters and specific pathogens varied among cities. The peak of RSV epidemics in Guangzhou occurred in the fall of 2023, earlier than in Beijing. CONCLUSION: The innovative program offered enhanced surveillance capabilities beyond traditional methods, enabling prompt feedback about test results and mitigating the risk of cross-infection caused by waits in healthcare facilities.

Association between influenza vaccination and one-year all-cause and cardiovascular mortality risk: A self-controlled case series and matched case-control study.

Debates surrounding the efficacy of influenza vaccination for survival benefits persist, and there is a lack of data regarding its duration of protection. A self-controlled case series (SCCS) and a 1:4 matched case-control study were conducted using the National Health Interview Survey (NHIS) and public-use mortality data from 2005 to 2018 in the United States. The SCCS study identified participants who received influenza vaccination within 12 months before the survey and subsequently died within 1 year of postvaccination. The matched case-control study paired participants who died during the influenza season at the time of survey with four survivors. Among 1167 participants in the SCCS study, there was a 46% reduction in all-cause mortality and a 43% reduction in cardiovascular mortality within 29-196 days of postvaccination. The greatest protection was observed during days 29-56 (all-cause mortality: RI: 0.19; 95% CI: 0.12-0.29; cardiovascular mortality: RI: 0.28; 95% CI: 0.14-0.56). Among 626 cases and 2504 controls included in the matched case-control study, influenza vaccination was associated with a reduction in all-cause mortality (OR: 0.74, 95% CI: 0.60-0.92) and cardiovascular mortality (OR: 0.64, 95% CI: 0.44-0.93) during the influenza season. This study highlights the importance of influenza vaccination in reducing the risks of all-cause and cardiovascular mortality, with effects lasting for approximately 6 months.

Biochar-enhanced three-dimensional conductive network thick electrodes for efficient lithium extraction from salt lake brines with high Magnesia-lithium ratios.

Enhancing the kinetic performance of thick electrodes is essential for improving the efficiency of lithium extraction processes. Biochar, known for its affordability and unique three-dimensional (3D) structure, is utilized across various applications. In this study, we developed a biochar-based, 3D-conductive network thick electrode (∼20 mg cm-2) by in-situ deposition of LiFePO4 (LFP) onto watermelon peel biomass (WB). Utilizing Density Functional Theory (DFT) calculations complemented by experimental data, we confirmed that this The thick electrode exhibits outstanding kinetic properties and a high capacity for lithium intercalation in brines, even in environments where the Magnesia-lithium ratios are significantly high. The electrode showed an impressive intercalation capacity of 30.67 mg g-1 within 10 min in a pure lithium solution. It also maintained high intercalation performance (31.17 mg g-1) in simulated brines with high Magnesia-lithium ratios. Moreover, in actual brine, it demonstrated a significant extraction capacity (23.87 mg g-1), effectively lowering the Magnesia-lithium ratio from 65 to 0.50. This breakthrough in high-conductivity thick electrode design offers new perspectives for lithium extraction technologies.

An effectiveness study of vaccination and quarantine combination strategies for containing mpox transmission on simulated college campuses.

The ongoing transmission of mpox in specific countries and regions necessitates urgent action. It is essential to implement targeted containment strategies that concentrate on high-risk populations and critical locations, such as college campuses, to effectively curb the spread of mpox. This study is dedicated to evaluating the performance of various vaccination and quarantine strategies in curbing the spread of mpox and estimating the outbreak risk. To accomplish this, we constructed a stochastic, agent-based, discrete-time susceptible-latent-infectious-recovered (SLIR) model, to examine mpox transmission on a simulated college campus. Our findings reveal that relying solely on PEP is insufficient in containing mpox effectively. To bolster the population immunity and protect the vulnerable, pre-exposure vaccination among high-risk populations prior to an outbreak is imperative. Our study demonstrates that a pre-exposure vaccination rate of 50% in high-risk populations can led to a remarkable 74.2% reduction of infections. This translated to a mere 1.0% cumulative infection incidence in the overall population. In cases where the desired vaccination coverage is not attainable, enhancing case detection and isolation measures can serve as an effective emergency response to contain mpox outbreaks. For pre-exposure vaccination coverage of 20% or lower, a 40% isolation ratio is necessary to keep the cumulative number of infections in check. However, when the coverage exceeds 30%, a reduced isolation ratio of 20% becomes sufficient to manage the outbreak effectively. These insights underscore the importance of strategic pre-exposure vaccination in conjunction with robust surveillance and isolation protocols to safeguard public health and prevent the escalation of mpox outbreaks.

A Large-Scale Online Survey on Clinical Severity and Associated Risk Factors for SARS-CoV-2 Omicron Infection - China, April-May 2023.

What is already known about this topic?: Individuals who initially contract severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) lack significant mixed immunity. Therefore, it is crucial to monitor the clinical characteristics and associated factors of these individuals in order to inform policy-making. What is added by this report?: The common symptoms reported were fever, cough, and sore throat. Reinfections and receiving four vaccination doses within a 6-month period were found to be associated with a shorter duration of virus shedding, decreased hospitalization rate, and reduced risk of pneumonia. Individuals aged 60 years and older, as well as those with underlying medical conditions, had a higher risk of developing pneumonia. What are the implication for public health practices?: Online surveys conducted through social media platforms have the potential to complement disease surveillance and data collection efforts. In terms of vaccination prioritization, it is recommended to prioritize older individuals and those with underlying diseases.

Enhanced Cathode Performance: The Heterostructure Construction of LiCoO2@Co3O4@Li6.4La3Zr1.4Ta0.6O12.

In this study, the heterostructure cathode material LiCoO2@Co3O4@Li6.4La3Zr1.4Ta0.6O12 was prepared by coating Li6.4La3Zr1.4Ta0.6O12 on the surface of LiCoO2 through a one-step solid-phase synthesis. The morphology, structure, electrical state, and elemental contents of both pristine and modified materials were assessed through a range of characterization techniques. Theoretical calculations revealed that the LCO@LLZTO material possessed a reduced diffusion barrier compared to LiCoO2, thereby facilitating the movement of Li ions. Electrochemical tests indicated that the capacity retention rate of the modified cathode composites stood at 70.43% following 300 cycles at a 2C rate. This high rate occurred because the Li6.4La3Zr1.4Ta0.6O12 film on the surface enhanced the migration of Li+, and the spinel phase of Co3O4 had better interfacial stability to alleviate the generation of microcracks by inhibiting the phase change from the layered phase to the rock-salt phase, which considerably improved the electrochemical properties.

Understanding Electrochemical Performance Enhancement with Quaternary NCMA Cathode Materials.

Ni-rich cathode materials show promise for use in lithium-ion batteries. However, a significant obstacle to their widespread adoption is the structural damage caused by microcracks. This research paper presents the synthesis of Ni-rich cathode materials, including LiNi0.8Co0.1Mn0.1O2 (referred to as NCM) and Li(Ni0.8Co0.1Mn0.1)0.98Al0.02O2 (referred to as NCMA), achieved through the high-temperature solid-phase method. Electrochemical (EC) testing results reveal the impressive EC performance of NCMA. NCMA exhibited a discharge capacity of 141.6 mAh g-1 and maintained a cycle retention rate of up to 74.92% after 300 cycles at a 1 C rate. In contrast, the NCM had a discharge capacity of 109.7 mAh g-1 and a cycle retention rate of 61.22%. Atomic force microscopy showed that the Derjaguin-Muller-Toporov (DMT) modulus value of NCMA exceeded that of NCM, signifying a greater mechanical strength of NCMA. Density functional theory calculations demonstrated that the addition of aluminum during the delithiation process led to the mitigation of anisotropic lattice changes and the stabilization of the NCMA structure. This improvement was attributed to the relatively stronger Al-O bonds compared to the Ni(Co, Mn)-O bonds, which reduced the formation of microcracks by enhancing NCMA's mechanical strength.

Application of Dexmedetomidine in Epidural Labor Analgesia: A Systematic Review and Meta-Analysis on Randomized Controlled Trials.

OBJECTIVES: To summarize and appraise the use of dexmedetomidine in epidural labor analgesia, we conducted a systematic review and meta-analysis of randomized controlled trials (RCTs). METHODS: We conducted the literature search about the RCTs of epidural labor analgesia with or without dexmedetomidine from inception until November 1, 2022, in the following databases: PubMed, Cochrane Library, and Embase. The primary outcome was visual analog scale (VAS) within 2 hours after epidural intubation. The secondary outcomes included the duration of the first and second labor stages, Apgar score, umbilical blood pH, dosage of analgesics, and side effects. RESULTS: Eight RCTs including 846 parturients were included. The VAS score of the dexmedetomidine group was significantly lower than that of the control group at the time of 15 minutes (mean difference [MD] -1.41, 95% confidence interval [CI] -2.23, -0.59), 30 minutes (MD -1.02, 95% CI -1.70, -0.33), 60 minutes (MD -0.90, 95% CI -1.36, -0.44), and 90 minutes (MD -0.70, 95% CI -1.16, -0.23). The incidence of pruritus in the dexmedetomidine group was lower than that of the control group （MD 0.28, 95% CI 0.11, 0.74), but the incidence of maternal bradycardia was higher (MD 6.41, 95% CI 1.64, 25.04). There were no significant difference in other outcomes. DISCUSSION: Dexmedetomidine combined with local anesthetic for epidural labor analgesia can improve the VAS score of parturients. Except for the increased incidence of maternal bradycardia, it seems to be safe for the parturients and fetuses.