期刊文献+
共找到112,505篇文章
< 1 2 250 >
每页显示 20 50 100
Spontaneous versus Induced Labor Delivery, a Retrospective Analysis 被引量:1
1
作者 D. Alalem S. Kafy +2 位作者 H. Hashim L. Aldukkan H. Bajahmom 《Advances in Reproductive Sciences》 2019年第1期1-6,共6页
Background: Induction of labor is the stimulation of the uterus to initiate the labor process whether by administering oxytocin, prostaglandin or reputing the membrane [1]. It was realized that the number of induction... Background: Induction of labor is the stimulation of the uterus to initiate the labor process whether by administering oxytocin, prostaglandin or reputing the membrane [1]. It was realized that the number of induction of labor patients was thought to be increasing in comparison with the spontaneous labor patients. Therefore, the complications of induced labor were higher. A detailed analysis was needed to confirm that. Objective: The aim of the study is to analyze the outcomes between spontaneous versus induced labor. Materials and Methods: A retrospective analysis was conducted at our tertiary care university hospital, in the period from December 2015 to December 2016 when 311 women were divided into two groups: group 1, women who had spontaneous labor (n = 106) compared with group 2, women who were labor induced (n = 205). Complications of pregnancy, delivery type, tear, episiotomy, blood transfusion and instruments used were analyzed retrospectively. Results: The mean ± SD of baseline characteristics, like age, height, weight, BMI and hemoglobin level for all study samples was 28.59 ± 5.95 years, 1.58 ± 0.06 m, 71.77 ± 13.42 kg, 28.59 ± 5.89 kg/m2 and 11.08 ± 1.45 g/dl respectively. A statistically significant difference was noticed in the duration of labor between spontaneous and induced labor (95% CI: 9.194 - 152.130;p-value 0.004 and OR: 0.239). There was no significant difference in complications, delivery type (Spontaneous Vaginal Delivery (SVD) or other), blood transfusion, and instrument used between women who had spontaneous labor versus induced labor. However, significant differences in tear (95% CI: 4.354 - 0.996;p-value 0.035) and episiotomy (95% CI: 0.928 - 0.224;p-value 0.028) were found between the two groups. In conclusion, the induced labor was found to be associated with high incidence of duration of labor, tear and episiotomy. Patients should always be counseled when there it is an option between the two delivery types. 展开更多
关键词 CESAREAN Section labor Induction SPONTANEOUS labor SPONTANEOUS VAGINAL Delivery (SVD) OXYTOCIN
下载PDF
Uterine Rupture in an Unscarred Uterus Following Induced Labor with Titrated Oral Misoprostol
2
作者 William Ceurvels Shi-Yann Cheng 《Open Journal of Obstetrics and Gynecology》 2015年第14期795-798,共4页
Misoprostol (Cytotec, Pfizer) is a prostaglandin E1 analogue widely used in labor induction. Understanding of potential risks of misoprostol in labor induction is lacking as the drug is used off-label in most countrie... Misoprostol (Cytotec, Pfizer) is a prostaglandin E1 analogue widely used in labor induction. Understanding of potential risks of misoprostol in labor induction is lacking as the drug is used off-label in most countries. A 35-year-old G3P2 woman with post-date pregnancy at 40 + 3 weeks was induced using titrated oral misoprostol. Following delivery, post-partum hemorrhage was noted and, upon discovery of a uterine wall rupture due to congenital weakness of the myometrium, emergency abdominal total hysterectomy was conducted. Following surgery, the patient made a full recovery and was discharged. The main contraindications for misoprostol in labor induction are a scarred uterus or multipara greater than 4. Uterine wall weakness should be considered as a potential contraindication. Extreme vigilance is required in use of misoprostol for labor induction. 展开更多
关键词 labor Induction MISOPROSTOL POST-PARTUM HEMORRHAGE UTERINE RUPTURE
下载PDF
Laboratory Experiment on Wave Induced Turbulence 被引量:1
3
作者 WEI Lai GUAN Changlong TROITSKAYA Yuliya 《Journal of Ocean University of China》 SCIE CAS CSCD 2018年第4期721-726,共6页
A laboratory experiment was conducted inside a wind wave tank to investigate the wave induced turbulence. In this experiment, the wave surface elevation and velocity beneath the water surface were measured simultaneou... A laboratory experiment was conducted inside a wind wave tank to investigate the wave induced turbulence. In this experiment, the wave surface elevation and velocity beneath the water surface were measured simultaneously to investigate the relation between the wave status and wave induced turbulence. The profile of the turbulent dissipation rate and Reynolds stress were calculated using experimental data. The effect of the wave status on turbulence is investigated with regard to the wind wave, swell, and mixed wave conditions. It was depicted that the turbulence decreased with increasing depth from the water surface and that the turbulence that was induced by a wave with larger wavelength and wave height is much stronger for the same wave status. Finally, we observed that the wind wave is more effective in activating the wave induced turbulence. 展开更多
关键词 WAVE induced TURBULENCE TURBULENT DISSIPATION RATE wave-turbulence DECOMPOSITION
下载PDF
Human induced pluripotent stem cell-derived therapies for regeneration after central nervous system injury
4
作者 Stephen Vidman Yee Hang Ethan Ma +1 位作者 Nolan Fullenkamp Giles W.Plant 《Neural Regeneration Research》 SCIE CAS 2025年第11期3063-3075,共13页
In recent years,the progression of stem cell therapies has shown great promise in advancing the nascent field of regenerative medicine.Considering the non-regenerative nature of the mature central nervous system,the c... In recent years,the progression of stem cell therapies has shown great promise in advancing the nascent field of regenerative medicine.Considering the non-regenerative nature of the mature central nervous system,the concept that“blank”cells could be reprogrammed and functionally integrated into host neural networks remained intriguing.Previous work has also demonstrated the ability of such cells to stimulate intrinsic growth programs in post-mitotic cells,such as neurons.While embryonic stem cells demonstrated great potential in treating central nervous system pathologies,ethical and technical concerns remained.These barriers,along with the clear necessity for this type of treatment,ultimately prompted the advent of induced pluripotent stem cells.The advantage of pluripotent cells in central nervous system regeneration is multifaceted,permitting differentiation into neural stem cells,neural progenitor cells,glia,and various neuronal subpopulations.The precise spatiotemporal application of extrinsic growth factors in vitro,in addition to microenvironmental signaling in vivo,influences the efficiency of this directed differentiation.While the pluri-or multipotency of these cells is appealing,it also poses the risk of unregulated differentiation and teratoma formation.Cells of the neuroectodermal lineage,such as neuronal subpopulations and glia,have been explored with varying degrees of success.Although the risk of cancer or teratoma formation is greatly reduced,each subpopulation varies in effectiveness and is influenced by a myriad of factors,such as the timing of the transplant,pathology type,and the ratio of accompanying progenitor cells.Furthermore,successful transplantation requires innovative approaches to develop delivery vectors that can mitigate cell death and support integration.Lastly,host immune responses to allogeneic grafts must be thoroughly characterized and further developed to reduce the need for immunosuppression.Translation to a clinical setting will involve careful consideration when assessing both physiologic and functional outcomes.This review will highlight both successes and challenges faced when using human induced pluripotent stem cell-derived cell transplantation therapies to promote endogenous regeneration. 展开更多
关键词 axon regeneration central nervous system regeneration induced pluripotent stem cells NEUROTRAUMA regenerative medicine spinal cord injury stem cell therapy
下载PDF
Butorphanol in epidural:Could this be the breakthrough solution for safe and effective labor analgesia that we've been waiting for?
5
作者 Anju Gupta Brinda Valecha Nishkarsh Gupta 《World Journal of Clinical Cases》 SCIE 2024年第32期6566-6569,共4页
The authors have conducted a comprehensive investigation into the safety and effectiveness of butorphanol for epidural analgesia during labor.Their critical analysis of the paper and discussion of the technique's ... The authors have conducted a comprehensive investigation into the safety and effectiveness of butorphanol for epidural analgesia during labor.Their critical analysis of the paper and discussion of the technique's advantages and disadvantages provide a thorough understanding of the topic. 展开更多
关键词 Metanalysis Protocol labor analgesia labor pain
下载PDF
Rural labor migration and farmers’arrangements of rice production systems in Central China:Insight from the intergenerational division of labor
6
作者 Xue Shen Quanyu Yang +1 位作者 Rongjun Ao Shengsheng Gong 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2024年第9期3200-3214,共15页
Rice production is crucial for food security in China,and its relationship with rural labor migration has been studied extensively.Labor migration in rural China has taken new forms in recent years.There has been a di... Rice production is crucial for food security in China,and its relationship with rural labor migration has been studied extensively.Labor migration in rural China has taken new forms in recent years.There has been a discernible trend wherein adult children have started migrating to cities while their elderly parents return to villages to re-engage in on-farm work.The phenomenon has notably shaped the intergenerational division of labor(IDL)within households.However,it remains to be seen how farmers adjust their rice production systems in response to the IDL.The age of 60 years for employment injury insurance is the eligibility threshold for off-farm employment and is used to obtain a source of exogenous variation in the IDL.Based on a representative household survey of 1,752 rice farmers in the Hubei Province of Central China,our fuzzy regression discontinuity analysis reveals that farmers in IDL households are more likely to adopt ratoon rice(RR)than single cropping rice(SR)or double cropping rice(DR).The effect of the IDL varies under different levels of operational scales and specialized agricultural service availability.Further analysis suggests that farmers’arrangements are associated with two potential mechanisms of downward intergenerational transfer.Monetary transfer for urban housing purchases increases RR in IDL households,and time transfer for intergenerational childcare significantly promotes SR in IDL households.This study enhances the understanding of the relationship between rural labor migration and rice production in China,providing a reference for adjusting rice production systems to ensure food security. 展开更多
关键词 labor migration intergenerational division of labor rice production systems fuzzy regression discontinuity Central China
下载PDF
Adaptation of Foreign Labor in Russia
7
作者 Nina V. Shabrova 《Sociology Study》 2012年第6期428-436,共9页
The article is devoted to problems of adaptation of foreign labor in Russia. The feature of approach to analysis of the problem lies in trying to examine this process at several levels: macro-level, meso-level, micro... The article is devoted to problems of adaptation of foreign labor in Russia. The feature of approach to analysis of the problem lies in trying to examine this process at several levels: macro-level, meso-level, micro-level, and individual level. The major factors influencing adaptation of foreign labor at each level are allocated. It is assumed between foreign workers and local communities. The author considers such aspects as the relation of local communities to arrival of foreign labor, the reasons for arrival of foreign labor to Russia and features of contact of local communities with foreign workers. This position is proved by means of a case study conducted in Yekaterinburg. 展开更多
关键词 Foreign labor adaptation of foreign labor adaptation levels of foreign labor stages of adaptation of foreign labor factors ofadaptation of foreign labor
下载PDF
Safety and effectiveness of butorphanol in epidural labor analgesia:A protocol for a systematic review and meta-analysis 被引量:3
8
作者 Guan-Cheng Tang Man He +1 位作者 Zhen-Zhao Huang Yan Cheng 《World Journal of Clinical Cases》 SCIE 2024年第8期1416-1421,共6页
BACKGROUND Epidural analgesia is the most effective analgesic method during labor.Butorphanol administered epidurally has been shown to be a successful analgesic method during labor.However,no comprehensive study has ... BACKGROUND Epidural analgesia is the most effective analgesic method during labor.Butorphanol administered epidurally has been shown to be a successful analgesic method during labor.However,no comprehensive study has examined the safety and efficacy of using butorphanol as an epidural analgesic during labor.AIM To assess butorphanol's safety and efficacy for epidural labor analgesia.METHODS The PubMed,Cochrane Library,EMBASE,Web of Science,China National Knowledge Infrastructure,and Google Scholar databases will be searched from inception.Other types of literature,such as conference abstracts and references to pertinent reviews,will also be reviewed.We will include randomized controlled trials comparing butorphanol with other opioids combined with local anesthetics for epidural analgesia during labor.There will be no language restrictions.The primary outcomes will include the visual analog scale score for the first stage of labor,fetal effects,and Apgar score.Two independent reviewers will evaluate the full texts,extract data,and assess the risk of bias.Publication bias will be evaluated using Egger's or Begg's tests as well as visual analysis of a funnel plot,and heterogeneity will be evaluated using the Cochran Q test,P values,and I2 values.Meta-analysis,subgroup analysis,and sensitivity analysis will be performed using RevMan software version 5.4.This protocol was developed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISMA)Protocols statement,and the PRISMA statement will be used for the systematic review.RESULTS This study provides reliable information regarding the safety and efficacy of using butorphanol as an epidural analgesic during labor.CONCLUSION To support clinical practice and development,this study provides evidence-based findings regarding the safety and efficacy of using butorphanol as an epidural analgesic during labor. 展开更多
关键词 Epidural analgesia during labor BUTORPHANOL SAFETY PROTOCOL META-ANALYSIS
下载PDF
Coupled multiphysical model for investigation of influence factors in the application of microbially induced calcite precipitation 被引量:1
9
作者 Xuerui Wang Pavan Kumar Bhukya +1 位作者 Dali Naidu Arnepalli Shuang Chen 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第6期2232-2249,共18页
The study presents a comprehensive coupled thermo-bio-chemo-hydraulic(T-BCH)modeling framework for stabilizing soils using microbially induced calcite precipitation(MICP).The numerical model considers relevant multiph... The study presents a comprehensive coupled thermo-bio-chemo-hydraulic(T-BCH)modeling framework for stabilizing soils using microbially induced calcite precipitation(MICP).The numerical model considers relevant multiphysics involved in MICP,such as bacterial ureolytic activities,biochemical reactions,multiphase and multicomponent transport,and alteration of the porosity and permeability.The model incorporates multiphysical coupling effects through well-established constitutive relations that connect parameters and variables from different physical fields.It was implemented in the open-source finite element code OpenGeoSys(OGS),and a semi-staggered solution strategy was designed to solve the couplings,allowing for flexible model settings.Therefore,the developed model can be easily adapted to simulate MICP applications in different scenarios.The numerical model was employed to analyze the effect of various factors,including temperature,injection strategies,and application scales.Besides,a TBCH modeling study was conducted on the laboratory-scale domain to analyze the effects of temperature on urease activity and precipitated calcium carbonate.To understand the scale dependency of MICP treatment,a large-scale heterogeneous domain was subjected to variable biochemical injection strategies.The simulations conducted at the field-scale guided the selection of an injection strategy to achieve the desired type and amount of precipitation.Additionally,the study emphasized the potential of numerical models as reliable tools for optimizing future developments in field-scale MICP treatment.The present study demonstrates the potential of this numerical framework for designing and optimizing the MICP applications in laboratory-,prototype-,and field-scale scenarios. 展开更多
关键词 MULTIPHYSICS Microbially induced calcite precipitation(MICP) Coupled thermo-bio-chemo-hydraulic(TBCH) model OpenGeoSys(OGS) Influence factors
下载PDF
Measurement of Surplus Labor in Viet Nam Agriculture 被引量:1
10
《Journal of Mathematics and System Science》 2014年第2期105-110,共6页
The large shift of surplus labor from agriculture to industry and services is seen in many countries around the world as well as in Vietnam in the process of industrialization and modernization of the country that has... The large shift of surplus labor from agriculture to industry and services is seen in many countries around the world as well as in Vietnam in the process of industrialization and modernization of the country that has set questions about the sustainability of rural surplus labor: is there still a source of surplus labor in rural areas? If so, how large is the source of surplus labor and how long it can be lasting? These questions were hotly debated in the literature abroad. But in Vietnam there is very little or hardly exchanged opinions about the concepts and methods of measurement of surplus labor in general and surplus labor in agriculture in particular. This article refers to the measurement approach of surplus labor in agriculture in Vietnam. 展开更多
关键词 labor force agricultural labor surplus labor surplus labor in agriculture.
下载PDF
Fibromyalgia Being Strongly Associated with Manual Labor Among Male Patients Attending Rheumatology Clinic
11
作者 George Habib Mohammad Haydar +1 位作者 Uriel Levinger Fahed Sakas 《Open Journal of Rheumatology and Autoimmune Diseases》 2024年第4期179-183,共5页
Introduction: Fibromyalgia is a common chronic pain syndrome, associated with different risk factors, including trauma. Many patients with the current or past history of manual labor attend our rheumatology clinic/s. ... Introduction: Fibromyalgia is a common chronic pain syndrome, associated with different risk factors, including trauma. Many patients with the current or past history of manual labor attend our rheumatology clinic/s. Should manual labor be considered a risk factor for the development of fibromyalgia? Patients and Methods: A prospective study, where all male patients seen at the rheumatology clinic/s with the diagnosis of fibromyalgia were asked about their present and past type of job/s. Manual job was defined as a job where the participant had a strenuous physical activity of more than 2 hours during the working day. A similar number of Ethnic- and age-matched female patients from the same clinic/s were recruited as a control group. Results: 69 and 40 Arab and Jewish male participants were recruited, respectively. 54% of the Arab male patients and 20% of the Jewish male patients were considered manual laborers. Construction and renovation accounted for 46% of the type of jobs practiced by Arab patients. Only 4% of Arab female patients were considered manual laborers. Conclusion: Manual labor seems to be a risk factor for the development of fibromyalgia among male laborers. 展开更多
关键词 Manual labor FIBROMYALGIA MALE Rheumatology Clinic
下载PDF
Advances in epidural labor analgesia:Effectiveness and treatment strategies of butorphanol
12
作者 Wan-Qiu Yu Zhao-Qiong Zhu Fu-Shan Tang 《World Journal of Clinical Cases》 SCIE 2024年第34期6669-6673,共5页
In this editorial,we provide a critical review of the article by Tang et al published in the World J Clin Cases,focusing on the utilization of butorphanol for epidural analgesia during labor.Our discussion encompasses... In this editorial,we provide a critical review of the article by Tang et al published in the World J Clin Cases,focusing on the utilization of butorphanol for epidural analgesia during labor.Our discussion encompasses recent research developments in epidural labor analgesia,specifically highlighting the current status of clinical applications of butorphanol and associated treatment approaches.Epidural analgesia is widely acknowledged as the primary method for pain management during labor,offering effective and prolonged pain relief while allowing mothers to remain alert and actively participate in the delivery process.Among the various drugs utilized for epidural labor analgesia,butorphanol has received increasing attention due to its potential efficacy and distinctive pharmacological properties.As a synthetic opioid analgesic,butorphanol exhibits both agonistic and antagonistic activity on opioid receptors,striking a balance between analgesia and minimizing side effects.Nevertheless,the safety and efficacy of butorphanol in epidural labor analgesia remains controversial.While certain studies have reported positive outcomes with butorphanol,including effective pain relief and a reduced incidence of side effects,others have raised concerns about its safety and efficacy compared to traditional opioids or alternative analgesics.In addition,the optimal dosing strategy and regimen of butorphanol as an adjuvant in epidural labor analgesia still need to be verified.Through comprehensive synthesis and analysis of existing literature,we aim to evaluate the current evidence regarding the use of butorphanol for epidural labor analgesia,delineate areas of consensus and controversy,and propose future avenues for research and clinical practice in this domain. 展开更多
关键词 BUTORPHANOL Epidural analgesia labor analgesia OPIOIDS Pain management
下载PDF
Fracture sealing based on microbially induced carbonate precipitation and its engineering applications:A review 被引量:1
13
作者 Zhichao Song Chuangzhou Wu +1 位作者 Zuoyong Li Danyi Shen 《Biogeotechnics》 2024年第4期41-51,共11页
In this review,the development and application of microbially induced carbonate precipitation(MICP)technology for the sealing of underground engineering fractures are discussed in detail.The importance of sealing micr... In this review,the development and application of microbially induced carbonate precipitation(MICP)technology for the sealing of underground engineering fractures are discussed in detail.The importance of sealing micro-fractures in an environmentally friendly and efficient manner is emphasized,and the potential of the MICP method in controlling pore and fracture seepage is highlighted.The fundamental mechanisms,key influencing factors,numerical models,and applications of the MICP in the fields of geological CO_(2) storage and oil resources development are comprehensively summarized in the paper.At the same time,the limitations of the existing research and the future research directions are discussed,especially in terms of improving the processing efficiency,environmental impacts,and cost considerations.Overall,the development of MICP technology provides a new environmentally friendly reinforcement method for geotechnical engineering and is expected to play a key role in the future development of underground space engineering. 展开更多
关键词 Microbially induced carbonate precipitation(MICP) Fracture sealing Bio-grouting Engineering applications
下载PDF
Association of Squatting Activities of Pregnant Women during the Antenatal Period and Labor Outcomes
14
作者 Sharada Manoj Aruna Siriwardena Pulukkuttige Ama Madhushani Perera Janakie Karunasingha 《Open Journal of Obstetrics and Gynecology》 2024年第2期278-294,共17页
Aim: To investigate impact of antenatal squatting activities on labour outcomes. Methods: All eligible primigravida women, with singleton cephalic fetuses, who presented to ward 18 of Colombo South Teaching Hospital, ... Aim: To investigate impact of antenatal squatting activities on labour outcomes. Methods: All eligible primigravida women, with singleton cephalic fetuses, who presented to ward 18 of Colombo South Teaching Hospital, Sri Lanka, during the period 1st of February to 28th of May 2017 were invited into the study. Those who were already in active stage of labor (at least more than two moderate contractions per 10 minutes) on admission were excluded. Demographic data such as age, ethnicity, religion, educational level, occupation, latrine type in use, and booking Body mass index (BMI) were collected via an interviewer administered questionnaire. Data related to labor (modified Bishop score at onset of active labor, labor augmentation, pain relief, labor duration, mode of delivery, episiotomy or tears) and neonatal outcome (birth weight, APGAR score at 1, 5, 10 minutes) were collected from delivery notes. A pre tested interviewer administered questionnaire was used to obtain data regarding routine squatting activities during the previous 6 months. Pain visual analogue scale was used on day after delivery to assess the degree of labour pain. Duration of each squatting activity per day and number of days engaged with the activity per week;were used to calculate total squatting hours per week. In the absence of an accepted threshold for adequate squatting, we employed the sample mean as an operational data-driven threshold to define “more” against “less” squatting activities. Women who did not have squatting activities were considered as the controls. We used chi-square and Fisher’s exact tests to compare characteristics and outcomes between those engaging in more and less levels of squatting activity. We fitted a series of logistic regression models with each dichotomized outcome as the dependent variable, more/less squatting activity as the main independent variable of interest, and age, gestation period, BMI and patient’s occupation as covariates. The resulting adjusted odds ratios (AOR) and their 95% confidence intervals (CI) and statistical significance (p < 0.05) were used to draw conclusions of adjusted associations. Results: We recruited 430 women into this study. Overall, 68% of the women were of 20 - 30 years old, 47% had normal body mass index and 65% were housewives. The most frequent squatting activities were for urination/defecation and clothes washing (146 and 62 minutes/week, respectively). Mean total time was 246 minutes per week, of which more than 147 women (34%) achieved above this level of squatting activities. Those with more squatting activities had a greater modified Bishop Score ≥ 6/10 (92% vs 82%;p < 0.01);labor duration of <6 hours (82% vs 56%;p < 0.01), less likely for labour augmentation (39% vs 51%;p < 0.01) and pain relief (53% vs 65%;p = 0.013). Similar results were obtained after adjustments for maternal age, BMI, gestational age and occupation. However, there were no significant differences in the mode of delivery (normal vaginal vs instrumental vs caesarean), episiotomy rate, birth weight and neonatal Apgar scores. Conclusion: Squatting activities of more than 246 minutes per week may improve labor outcome. Women should be encouraged to increase squatting exercises or incorporate more habitual squatting activities antenatally. 展开更多
关键词 Antenatal Squatting labor Outcomes
下载PDF
Flow-Slip Stability Behavior of Calcareous Sand Treated by Microbially Induced Carbonate Precipitation Technology
15
作者 KOU Hailei HE Xiang +4 位作者 HOU Wangxiang LI Zhendong ZHANG Xixin AN Zhaotun LU Jiaqing 《Journal of Ocean University of China》 SCIE CAS CSCD 2024年第5期1381-1389,共9页
Flow-slip damage commonly destabilizes coastal slopes.Finding a slope stabilization method for calcareous sands in the South China Sea is crucial.Microbially induced calcite precipitation is a promising,eco-friendly m... Flow-slip damage commonly destabilizes coastal slopes.Finding a slope stabilization method for calcareous sands in the South China Sea is crucial.Microbially induced calcite precipitation is a promising,eco-friendly method for soil stabilization.This study investigates the effect of microbial treatments,initial relative density,initial cell pressure,and initial stress ratio on the flow-slip stability of calcareous sand specimens by using constant shear drained tests.These tests lay the foundation to study the mechanical instability of sand slopes.Results show that the microbial-treated specimens maintain stable stresses longer,take longer to reach the instability,and withstand larger volumetric strains.Microbial treatment effectively enhances sand stability under constant shear drainage,with improvements amplified by higher initial relative density and initial cell pressure.In addition,a smaller initial stress ratio reduces shear effects on the specimen and increases resistance to flow slides.Microanalysis reveals that the flow-slip stability of calcareous sand slopes is enhanced by contact cementation,particle coating,void filling,and mutual embedment of calcium carbonate crystals. 展开更多
关键词 clcareous sand microbially induced carbonate precipitation constant shear drained tests flow-slip stability
下载PDF
Microwave field sensor based on cold cesium Rydberg three-photon electromagnetically induced spectroscopy
16
作者 Yuan-Yuan Wu Yun-Hui He +1 位作者 Yue-Chun Jiao Jian-Ming Zhao 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第11期249-254,共6页
We present the electromagnetically induced transparency(EIT)spectra of cold Rydberg four-level cascade atoms consisting of the 6S_(1/2)→6P_(3/2)→7S_(1/2)→60P_(3/2) scheme.A coupling laser drives the Rydberg transit... We present the electromagnetically induced transparency(EIT)spectra of cold Rydberg four-level cascade atoms consisting of the 6S_(1/2)→6P_(3/2)→7S_(1/2)→60P_(3/2) scheme.A coupling laser drives the Rydberg transition,a dressing laser couples two intermediate levels and a weak probe laser probes the EIT signal.We numerically solve the Bloch equations and investigate the dependence of the probe transmission rate signal on the coupling and dressing lasers.We find that the probe transmission rate can display an EIT or electromagnetically induced absorption(EIA)profile,depending on the Rabi frequencies of the coupling and dressing lasers.When we increase the Rabi frequency of the coupling laser and keep the Rabi frequency of the probe and dressing laser fixed,flipping of the EIA to EIT spectrum occurs at the critical coupling Rabi frequency.When we apply a microwave field coupling the transition 60P_(3/2)→61S_(1/2),the EIT spectrum shows Autler–Townes splitting,which is employed to measure the microwave field.The theoretical measurement sensitivity can be 1.52×10^(−2) nV・cm^(−1)・Hz−^(1/2) at the EIA–EIT flipping point. 展开更多
关键词 Rydberg atoms atomic microwave sensor electromagnetically induced transparency and absorption
下载PDF
Is Induction of Labor with Early Rupture of Membranes Associated with an Increased Rate of Clinical Chorioamnionitis?
17
作者 Laura Rankin Matthew Romagano +1 位作者 Shauna Williams Joseph Apuzzio 《Open Journal of Obstetrics and Gynecology》 2024年第2期240-249,共10页
Objective: The objective of this study was to determine if early rupture of membranes (ROM) in women undergoing induction of labor (IOL) at term is associated with an increased rate of clinical chorioamnionitis. Study... Objective: The objective of this study was to determine if early rupture of membranes (ROM) in women undergoing induction of labor (IOL) at term is associated with an increased rate of clinical chorioamnionitis. Study Design: A retrospective cohort study was performed on women undergoing IOL. Early ROM was defined as ROM at a modified Bishop score less than 5, cervical dilation less than 4 cm, or cervical effacement less than 80%. The rate of clinical chorioamnionitis was compared between women with early and late ROM. Results: The rate of clinical chorioamnionitis was 8.6% (24/279). ROM at an effacement of less than 80% was associated with a rate of clinical chorioamnionitis of 15.4% (12/78) compared to 6.0% (12/201) at an effacement of equal to or greater than 80%, p = 0.017. The rate of cesarean delivery was higher for patients with early ROM by any definition: 32% compared to 17.5% by modified Bishop score (p = 0.031), 32.4% versus 18.2% by cervical dilation (p = 0.049), and 33.3% versus 14.9% by cervical effacement (p = 0.001). Conclusions: In patients undergoing IOL, early ROM may be associated with an increased rate of clinical chorioamnionitis when performed at a cervical effacement of less than 80% and an increased rate of cesarean delivery. 展开更多
关键词 Amniotomy Cesarean Delivery CHORIOAMNIONITIS Induction of labor Intraamniotic Infection Perinatal Infection Rupture of Membranes Term Pregnancy
下载PDF
China’s Labor Standard Legislation: Confused Reality and Unclear Future
18
作者 Liu Dawei 《学术界》 CSSCI 北大核心 2020年第6期210-217,共8页
The reasons why labor standards law has not been enacted so far include the unreadiness of entrepreneurs and enterprises as well as legislators and the market. It is a great challenge for legislators because they need... The reasons why labor standards law has not been enacted so far include the unreadiness of entrepreneurs and enterprises as well as legislators and the market. It is a great challenge for legislators because they need to focus on the coordination of relationship between central and local labor standards legislation,on special problems of sectors or industries,on coordination of special industries and general industries. in addition to many other historical factors. The introduction of labor standards legislation must be based on a good familiarity of current situation and international labor standards,the frequent points of labor disputes in China,and the specific characteristics of different regions and industries,which is also the mission and responsibility of the legislators. 展开更多
关键词 labor laws basic labor standards labor standards law labor legislation
下载PDF
Implications for fault reactivation and seismicity induced by hydraulic fracturing
19
作者 Zi-Han Sun Ming-Guang Che +3 位作者 Li-Hong Zhu Shu-Juan Zhang Ji-Yuan Lu Chang-Yu Jin 《Petroleum Science》 SCIE EI CAS CSCD 2024年第2期1081-1098,共18页
Evaluating the physical mechanisms that link hydraulic fracturing(HF) operations to induced earthquakes and the anticipated form of the resulting events is significant in informing subsurface fluid injection operation... Evaluating the physical mechanisms that link hydraulic fracturing(HF) operations to induced earthquakes and the anticipated form of the resulting events is significant in informing subsurface fluid injection operations. Current understanding supports the overriding role of the effective stress magnitude in triggering earthquakes, while the impact of change rate of effective stress has not been systematically addressed. In this work, a modified critical stiffness was brought up to investigate the likelihood, impact,and mitigation of induced seismicity during and after hydraulic fracturing by developing a poroelastic model based on rate-and-state fraction law and linear stability analysis. In the new criterion, the change rate of effective stress was considered a key variable to explore the evolution of this criterion and hence the likelihood of instability slip of fault. A coupled fluid flow-deformation model was used to represent the entire hydraulic fracturing process in COMSOL Multiphysics. The possibility of triggering an earthquake throughout the entire hydraulic fracturing process, from fracturing to cessation, was investigated considering different fault locations, orientations, and positions along the fault. The competition between the effects of the magnitude and change rate of effective stress was notable at each fracturing stage. The effective stress magnitude is a significant controlling factor during fracturing events, with the change rate dominating when fracturing is suddenly started or stopped. Instability dominates when the magnitude of the effective stress increases(constant injection at each fracturing stage) and the change rate of effective stress decreases(the injection process is suddenly stopped). Fracturing with a high injection rate, a fault adjacent to the hydraulic fracturing location and the position of the junction between the reservoir and fault are important to reduce the Coulomb failure stress(CFS) and enhance the critical stiffness as the significant disturbance of stresses at these positions in the coupled process. Therefore,notable attention should be given to the injection rate during fracturing, fault position, and position along faults as important considerations to help reduce the potential for induced seismicity. Our model was verified and confirmed using the case of the Longmaxi Formation in the Sichuan Basin, China, in which the reported microseismic data were correlated with high critical stiffness values. This work supplies new thoughts of the seismic risk associated with HF engineering. 展开更多
关键词 Hydraulic fracturing Coulomb failure stress Rate-and-state fraction model Linear stability analysis Critical stiffness Seismically induced fault
下载PDF
Patient-derived induced pluripotent stem cells with a MERTK mutation exhibit cell junction abnormalities and aberrant cellular differentiation potential
20
作者 Hang Zhang Ling-Zi Wu +1 位作者 Zhen-Yu Liu Zi-Bing Jin 《World Journal of Stem Cells》 SCIE 2024年第5期512-524,共13页
BACKGROUND Human induced pluripotent stem cell(hiPSC)technology is a valuable tool for generating patient-specific stem cells,facilitating disease modeling,and invest-igating disease mechanisms.However,iPSCs carrying ... BACKGROUND Human induced pluripotent stem cell(hiPSC)technology is a valuable tool for generating patient-specific stem cells,facilitating disease modeling,and invest-igating disease mechanisms.However,iPSCs carrying specific mutations may limit their clinical applications due to certain inherent characteristics.AIM To investigate the impact of MERTK mutations on hiPSCs and determine whether hiPSC-derived extracellular vesicles(EVs)influence anomalous cell junction and differentiation potential.METHODS We employed a non-integrating reprogramming technique to generate peripheral blood-derived hiPSCs with and hiPSCs without a MERTK mutation.Chromo-somal karyotype analysis,flow cytometry,and immunofluorescent staining were utilized for hiPSC identification.Transcriptomics and proteomics were employed to elucidate the expression patterns associated with cell junction abnormalities and cellular differentiation potential.Additionally,EVs were isolated from the supernatant,and their RNA and protein cargos were examined to investigate the involvement of hiPSC-derived EVs in stem cell junction and differentiation.RESULTS The generated hiPSCs,both with and without a MERTK mutation,exhibited normal karyotype and expressed pluripotency markers;however,hiPSCs with a MERTK mutation demonstrated anomalous adhesion capability and differentiation potential,as confirmed by transcriptomic and proteomic profiling.Furthermore,hiPSC-derived EVs were involved in various biological processes,including cell junction and differentiation.CONCLUSION HiPSCs with a MERTK mutation displayed altered junction characteristics and aberrant differentiation potential.Furthermore,hiPSC-derived EVs played a regulatory role in various biological processes,including cell junction and differentiation. 展开更多
关键词 Cell junction Cellular differentiation Extracellular vesicle Human induced pluripotent stem cells TRANSCRIPTOMICS Proteomics
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部