Let M be a compact n-manifold of positive sectional curvature.We will review classical results on the fundamental group of M,a motivation on the c(n)-cyclic conjecture that the fundamental group of M contains a cyclic...Let M be a compact n-manifold of positive sectional curvature.We will review classical results on the fundamental group of M,a motivation on the c(n)-cyclic conjecture that the fundamental group of M contains a cyclic subgroup of index bounded above by c(n),a constant depending only on n,and we will survey partial results(up to date)on the c(n)-cyclic conjecture.展开更多
To overcome the limitations of low efficiency and reliance on manual processes in the measurement of geometric parameters for bridge prefabricated components,a method based on deep learning and computer vision is deve...To overcome the limitations of low efficiency and reliance on manual processes in the measurement of geometric parameters for bridge prefabricated components,a method based on deep learning and computer vision is developed to identify the geometric parameters.The study utilizes a common precast element for highway bridges as the research subject.First,edge feature points of the bridge component section are extracted from images of the precast component cross-sections by combining the Canny operator with mathematical morphology.Subsequently,a deep learning model is developed to identify the geometric parameters of the precast components using the extracted edge coordinates from the images as input and the predefined control parameters of the bridge section as output.A dataset is generated by varying the control parameters and noise levels for model training.Finally,field measurements are conducted to validate the accuracy of the developed method.The results indicate that the developed method effectively identifies the geometric parameters of bridge precast components,with an error rate maintained within 5%.展开更多
Radar cross section(RCS)plays a critical role in modeling target scattering characteristics and enhancing the precision of target detection and localization in integrated sensing and communication(ISAC)systems.This pa...Radar cross section(RCS)plays a critical role in modeling target scattering characteristics and enhancing the precision of target detection and localization in integrated sensing and communication(ISAC)systems.This paper investigates the human body RCS at 26 GHz via multiangle channel measurements under different clothing conditions.Based on calibrated electromagnetic(EM)parameters,the RCS characteristics of the human body in far-field conditions are analyzed using ray-tracing(RT)simulations.Some suggestions for the design of ISAC systems are also discussed.The results provide a solid theoretical foundation and practical reference for the modeling of target scattering characteristics for ISAC channels.展开更多
BACKGROUND Intrathecal bupivacaine is the traditional anesthetic drug used in spinal anesthesia for caesarean sections(CSs),but ropivacaine has emerged as a potential alter-native.This meta-analysis compares the effic...BACKGROUND Intrathecal bupivacaine is the traditional anesthetic drug used in spinal anesthesia for caesarean sections(CSs),but ropivacaine has emerged as a potential alter-native.This meta-analysis compares the efficacy and safety of intrathecal hyper-baric bupivacaine vs hyperbaric ropivacaine for cesarean sections.AIM To systematically evaluate and compare the efficacy and safety of intrathecal hyperbaric bupivacaine and hyperbaric ropivacaine for spinal anesthesia in CSs.METHODS A thorough search of electronic databases was carried out to find pertinent randomized controlled trials(RCTs)comparing intrathecal hyperbaric ropi-vacaine and hyperbaric bupivacaine during CSs.PubMed,Cochrane database,Google Scholar,and Scopus were searched,and papers from January 2000 to January 2024 were deemed eligible and filtered using predetermined inclusion and exclusion criteria.Studies were assessed for methodological quality,and data were extracted for time to adequate anesthesia(sensory and motor blockade),duration of sensory and motor block,hemodynamic changes and side effect profile.The standardized mean difference with 95%CI was used for continuous data.Dichotomous variables were assessed using the Mantel-Haenszel test and the random effect model to compute the odds ratio.RESULTS Total 8 RCTs were selected from a pool of 119 search results for meta-analysis.The meta-analysis evaluated pooled effect sizes and assessed heterogeneity among the studies.The primary objective was to compare key outcomes to identify any significant variances in efficacy and safety profiles between two local anesthetics.The analysis revealed that the difference in the onset of sensory blockade between the two local anesthetics was statistically insignificant(P=0.1586).However,the onset of motor blockade appeared to be faster with bupivacaine(P=0.03589).Additionally,the regression of sensory and motor blockade occurred earlier in the ropivacaine group.Furthermore,the duration of the first analgesic effect was shorter with a significance level of P<0.05.Regarding side effects profile,including hypotension,nausea,and shivering,the study did not observe any significant differences between the two groups.CONCLUSION This meta-analysis offers insights into the effectiveness and safety of hyperbaric bupivacaine vs ropivacaine for cesarean sections.Hyperbaric ropivacaine had a comparable safety profile and faster regression of sensory and motor blockade than hyperbaric bupivacaine,perhaps aiding early mobilization of parturient and facilitating mother-child bonding.Choosing ropivacaine may offer benefits beyond efficacy for cesarean section patients and short surgical procedures.展开更多
Background: Cesarean sections have become increasingly prevalent in both developed and developing nations. Nevertheless, postoperative complications, including surgical site infections (SSIs), remain a substantial con...Background: Cesarean sections have become increasingly prevalent in both developed and developing nations. Nevertheless, postoperative complications, including surgical site infections (SSIs), remain a substantial concern that contributes to heightened morbidity and mortality. This study is designed to evaluate the frequency and key determining factors associated with surgical site infections following cesarean section procedures in a tertiary care hospital in Bangladesh. Materials and Methods: This observational cross-sectional study, conducted at the Gynecology Department of Dhaka Medical College Hospital, involved 100 patients aged 15 - 45 who had cesarean deliveries. Data was collected during hospitalization and post-discharge and analyzed to determine the prevalence and relationship between socio-demographic characteristics and surgical site infection. Results: Among the study participants, 14% developed surgical site infections following cesarean operations. More than half of these patients were under the age of 25, with a mean age of 24.45 ± 4.44 years. Surgical site infections were more prevalent in individuals over 30 years old (P-value Conclusion: Post-cesarean surgical site infections are notably prevalent among the participants in this study. Several risk factors have been identified, including age, body mass index (BMI), socioeconomic status, anemia, preterm delivery, personal hygiene practices, regular menstrual cycles, and adherence to antenatal check-ups. The implementation of an effective awareness program, coupled with updated antibiotic protocols, is crucial for significantly reducing the incidence of these infections.展开更多
This study introduces a novel flow-through cowcatcher with integrated inlet and outlet channels as an aerodynamic noise mitigation strategy for the nose car of a high-speed train.The wall-adapting local eddy-viscosity...This study introduces a novel flow-through cowcatcher with integrated inlet and outlet channels as an aerodynamic noise mitigation strategy for the nose car of a high-speed train.The wall-adapting local eddy-viscosity large eddy simulation(WALE-LES)combined with the Ffowcs Williams-Hawkings(FW-H)acoustic analogy approach is employed to evaluate its impact on the aerodynamic and aeroacoustic characteristics of the leading bogie region.Compared with the conventional closed cowcatcher,results show that the flow-through structure suppresses the flow separation,promotes more stable vortex evolution within the bogie cavity,and reduces the spatial extent of high amplitude wall pressure fluctuations up to 40%,mitigating effectively the generation of aerodynamic noise.Semi anechoic wind tunnel experiments validate the simulation results and demonstrate that the sound pressure levels at the far field observers decrease by 0.4-0.6 dB(A)with the flow-through cowcatcher applied underneath the nose car.The dominant sound source around the leading bogie region is shrunk with intensity reduced about 1.0 dB(A).These findings confirm the effectiveness of the flow-through cowcatcher in reducing the aerodynamic noise produced from the leading bogie region,providing both theoretical insight and engineering guidance for structural optimization and low-noise design of the nose car in a high-speed train.展开更多
Tissue clearing combined with high-resolution confocal imaging is a cutting-edge approach for dissecting the three-dimensional(3D)architecture of tissues and deciphering cellular spatial interactions under physiologic...Tissue clearing combined with high-resolution confocal imaging is a cutting-edge approach for dissecting the three-dimensional(3D)architecture of tissues and deciphering cellular spatial interactions under physiological and pathological conditions.Deciphering the spatial interaction of leptin receptor-expressing(LepR^(+))stromal cells with other compartments in the bone marrow is crucial for a deeper understanding of the stem cell niche and the skeletal tissue.In this study,we introduce an optimized protocol for the 3D analysis of skeletal tissues,enabling the visualization of hematopoietic and stromal cells,especially LepR+stromal cells,within optically cleared bone hemisections.Our method preserves the 3D tissue architecture and is extendable to other hematopoietic sites such as calvaria and vertebrae.The protocol entails tissue fixation,decalcification,and cryosectioning to reveal the marrow cavity.Completed within approximately 12 days,this process yields highly transparent tissues that maintain genetically encoded or antibody-stained fluorescent signals.The bone hemisections are compatible with diverse antibody labeling strategies.Confocal microscopy of these transparent samples allows for qualitative and quantitative image analysis using Aivia or Bitplane Imaris software,assessing a spectrum of parameters.With proper storage,the fluorescent signal in the stained and cleared bone hemisections remains intact for at least 2–3 months.This protocol is robust,straightforward to implement,and highly reproducible,offering a valuable tool for tissue architecture and cellular interaction studies.展开更多
Acute pulmonary edema is a leading cause of death in patients with preeclampsia.The authors reported a case of a pregnant woman at 25 weeks of gestation with severe preeclampsia complicated by pulmonary edema,who requ...Acute pulmonary edema is a leading cause of death in patients with preeclampsia.The authors reported a case of a pregnant woman at 25 weeks of gestation with severe preeclampsia complicated by pulmonary edema,who required an emergency cesarean section,posing a significant challenge to the anesthesiologist.The patient had developed Type 1 respiratory failure and needed supplemental oxygen with high-flow nasal oxygen.Due to contraindications for neuraxial anesthesia,the cesarean section was performed under general anesthesia.After induction of anesthesia,the patient’s hypoxemia worsened.Eventually,after treatment with fluid restriction,diuretics,and albumin,oxygenation improved gradually,and the procedure was performed successfully.Both the patient and the newborn had a good prognosis.展开更多
Objective:The objective of this study is to determine the effect of nurse-led instructional video(NLIV)on anxiety,satisfaction,and recovery among mothers admitted for cesarean section(CS).Materials and Methods:A quasi...Objective:The objective of this study is to determine the effect of nurse-led instructional video(NLIV)on anxiety,satisfaction,and recovery among mothers admitted for cesarean section(CS).Materials and Methods:A quasi-experimental design was carried out on the mothers scheduled for CS.Eighty participants were selected by a purposive sampling technique,which were divided(40 participants in each group)into an experimental group and a control group.Nurse-led informational video(NLIV)was shown to the experimental group,and routine care was provided for the control group.Modified hospital anxiety scale(HADS),scale for measuring maternal satisfaction in cesarean birth,and obstetric quality of recovery following cesarean delivery were used to assess anxiety,satisfaction,and recovery.Results:Both the experimental and control groups showed significant reductions in anxiety by the first postintervention day(P<0.001),with the experimental group experiencing a greater mean reduction(mean difference[MD]=4.37)than the control group(MD=3.35)but the intergroup difference was not statistically significant(P>0.05).The experimental group reported significantly higher satisfaction scores(175.55±9.42)on the 3rd postoperative day compared to the control group(151.93±14.89;P<0.001).Similarly,the experimental group’s recovery scores(79.90±6.24)were considerably higher than those of the control group(62.45±15.18;P<0.001).On the 3rd postintervention day,satisfaction was significantly associated with age(P<0.001),and recovery with gravidity(P<0.05).Conclusions:NLIV can be used in the preoperative period to reduce anxiety related to CS and to improve satisfaction and recovery after the CS.展开更多
OBJECTIVE:To evaluate the clinical outcome of Traditional Chinese Medicine(TCM)syndrome differentiation combined with hysteroscopic treatment for uterine incision defect after cesarean section[previous cesarean scar d...OBJECTIVE:To evaluate the clinical outcome of Traditional Chinese Medicine(TCM)syndrome differentiation combined with hysteroscopic treatment for uterine incision defect after cesarean section[previous cesarean scar defect(PCSD)]after cesarean section.METHODS:This is a single-center retrospective study.A total of 120 PCSD patients were enrolled from February 2022 to February 2023 and divided into two groups according to different treatment methods,the TCM group(n=60)and the control group(n=60).The control group was treated with hysteroscopy,and the TCM group combined TCM syndrome differentiation with hysteroscopy.Clinical outcome included menstrual scores,menstrual days,TCM symptom scores and intrauterine pregnancy recurrence rate was analyzed in two groups.RESULTS:The total response rate of the TCM group was significantly higher than that of the control group(P<0.05);after treatment,the menstrual scores,menstrual days and TCM symptoms of the two groups were decreased,and the menstrual scores,menstrual days and TCM symptoms of the TCM group were all lower than that of the control group(P<0.05);the recurrence rate of the TCM group was significantly lower than that of the control group(P<0.05).Follow-up results showed higher healing of incisional scar diverticulum in the TCM group than in the control group(P<0.05).The duration of menstruation before and after treatment,and the TCM group was better than the control group(P<0.05).CONCLUSION:TCM syndrome differentiation combined with hysteroscopy presented favorable outcome on the prolonged menstrual period of PCSD,which could significantly improve the recovery of menstruation,relief the symptoms of TCM,reduce the recurrence rate and accelerate wound healing.展开更多
The purpose of this article is to explore the design of compound interchange interweaving sections on expressways.During the research phase,based on the support of the literature research method,the classification and...The purpose of this article is to explore the design of compound interchange interweaving sections on expressways.During the research phase,based on the support of the literature research method,the classification and development of the interchange system,as well as the design forms of the compound interchange interweaving section,were analyzed.Subsequently,based on the case method,the design of the compound interchange interweaving section of the ShiWu and ShiBai expressways in Shiyan,Hubei Province,was discussed,and a design scheme and scheme comparison were proposed.It is hoped that this article can provide technical reference and ideas for China’s road and bridge engineering teams,ensuring that the design results can not only guarantee the normal passage of traffic on the North Intersection Expressway but also ensure the straight-line traffic capacity of the main highway under the background of dislocation intersection,achieving smooth and safe transitions between different expressways.展开更多
The direct and dissociative ionizations of oxygen molecule are investigated experimen-tally by electron collision with energies from 350 eV to 8000 eV.The absolute ionization cross sections for the product ions(O_(2)^...The direct and dissociative ionizations of oxygen molecule are investigated experimen-tally by electron collision with energies from 350 eV to 8000 eV.The absolute ionization cross sections for the product ions(O_(2)^(2+),O_(2)^(2+)O^(+),O^(2+),and their total)and two Coulomb explosion channels(O^(+)+O^(+)and O^(2+)+O^(+))are obtained by putting the data of O^(2+)on the scale of Ar+from O_(2)and Ar gases mixed with a fixed relative flow ratio of 1:1.The experimental errors are assessed by taking uncertainties of various factors into account.The present absolute cross sections are well consistent with the previous data in the overlapped energy range below 1000 eV.展开更多
Emergency cesarean section has always been a challenge for patients,surgeons,and anesthesiologists,as it endangers the safety of both parturients and fetuses.Obesity and hypertension are common among pregnant women,bu...Emergency cesarean section has always been a challenge for patients,surgeons,and anesthesiologists,as it endangers the safety of both parturients and fetuses.Obesity and hypertension are common among pregnant women,but severe obesity combined with refractory hypertension is very rare in clinical practice.The optimal anesthetic management strategy for obese pregnant women with a difficult airway and poorly controlled hypertension remains debatable.This report presents a 32-year-old woman with severe obesity and refractory hypertension at 36 weeks and 6 days of pregnancy.Owing to fetal heart rate abnormalities,she was scheduled for emergency cesarean section.Given the urgency of the fetal condition and the challenges posed by the patient's obesity for epidural puncture,the anesthesiologist opted for rapid sequence induction and tracheal intubation instead of intervertebral anesthesia.Short-acting antihypertensive medications were adminstrated preoperatively to control elevated blood pressure,and vasopressor agents were continuously infused during surgery to prevent severe hypotension induced by anesthetic drugs.The entire anesthesia and surgical procedure proceeded uneventfully,with no major adverse events observed.Both the patient and fetus achieved favorable outcomes.This case indicates that early anesthetic risk assessment and meticulous pre-delivery planning are paramount,necessitating personalized management of airway and hemodynamics to optimize outcomes in obese parturients.展开更多
Background:Postcesarean mothers often experience delayed lactogenesis II due to surgical stress and reduced oxytocin levels.Almond oil breast massage is a nonpharmacological intervention thought to enhance prolactin r...Background:Postcesarean mothers often experience delayed lactogenesis II due to surgical stress and reduced oxytocin levels.Almond oil breast massage is a nonpharmacological intervention thought to enhance prolactin release and improve milk production.Objective:The objective of the study was to evaluate the effectiveness of almond oil massage on breast milk adequacy among primigravida lower segment cesarean section(LSCS)mothers.Materials and Methods:A randomized pretest-posttest control group design was conducted among 60 primigravida mothers post-LSCS,randomly assigned to experimental(n=30)and control(n=30)groups.The experimental group received three daily almond oil breast massages(5-10 mL;5 min/breast)for 3 days;controls received routine care.Breast milk adequacy was measured using a validated 16-item rating scale at baseline and day 4 post-intervention.Results:The mean breast milk adequacy scores increased from 29.30±1.915 to 39.80±1.690 in the experimental group(t=22.15,P<0.001).Control group change(29.93±2.132-30.27±2.116)was non-significant(t=0.776,P>0.05).Posttest scores between the two groups differed significantly between groups(t=19.282,P<0.001).Conclusion:Almond oil breast massage significantly enhances breast milk adequacy in post-LSCS mothers and can be integrated into routine postnatal nursing care.展开更多
Here,we report the spin-orbit state-resolved differential cross sections(DCSs)for the prototype barrierless reaction S(^(1)D)+HD.Both product channels,namely H+SD(^(2)Π_(3/2,1/2))and D+SH(^(2)Π_(3/2,1/2)),were measu...Here,we report the spin-orbit state-resolved differential cross sections(DCSs)for the prototype barrierless reaction S(^(1)D)+HD.Both product channels,namely H+SD(^(2)Π_(3/2,1/2))and D+SH(^(2)Π_(3/2,1/2)),were measured by high-resolution crossed molecular beam experiments.The DCSs of the two product channels show an overall forward-backward symmetry,in accordance with statistical model predictions.However,the DCSs for different spin-orbit manifolds show different preferences in forward or backward scattering directions at the same collision energies.This study reveals that,even though the title reaction proceeds via the long-lived complex mechanism,the spin-orbit coupling effects in the product channels play an important role in the reaction process.展开更多
Rock thin section description is an essential method for examining lithology,structure,diagenesis,and sedimentary environment,playing a pivotal role in fields such as geology,geophysics,and petroleum exploration.To ov...Rock thin section description is an essential method for examining lithology,structure,diagenesis,and sedimentary environment,playing a pivotal role in fields such as geology,geophysics,and petroleum exploration.To overcome the challenges of subjectivity,low efficiency,and high expertise requirements in describing rock thin sections,we design a multimodal mapping network,ThinGPT,which aligns the feature spaces of the contrastive language-image pre-training(CLIP)and Generative Pre-trained(GPT-2)through network training.Given the high frequency of keywords and the structured sentence patterns in thin-section descriptions,we introduce a tokenization method tailored for rock thin sections.This approach enhances GPT-2's ability to effectively encode text and produce text feature vectors.We conducted comparative experiments using ThinGPT and other models on common sedimentary rocks.The results demonstrate that ThinGPT exhibits excellent potential in generating thin-section feature descriptions of rocks.Based on the geological expert evaluation criteria proposed in this study,ThinGPT achieved a score of 1.62 on the test set.For model complexity,ThinGPT avoids heavy initial training of large language models(LLMs).This training strategy makes the model lighter and improves the efficiency of rock thin section descriptions.As an innovative application of a LLMs within a lightweight architecture for rock thin section description,ThinGPT has significant implications for intelligent geology,geophysics,and petroleum exploration.展开更多
Foamed concrete is widely employed in highway transition sections,due to its lightweight,high-strength,and effective settlement control.It is crucial to investigate its dynamic response linked to the traffic-loading i...Foamed concrete is widely employed in highway transition sections,due to its lightweight,high-strength,and effective settlement control.It is crucial to investigate its dynamic response linked to the traffic-loading influence zone of embankment and transition section smoothness.In this study,in-situ truck tests were conducted in the road-culvert-bridge transition section to obtain the spatio-temporal response patterns.Based on the vertical response,the influence zone was ascertained.Depending on the longitudinal response,the smoothness was evaluated by equivalent dynamic stiffness(EDS)and acceleration variation rate(AVR).Furthermore,the response discrepancies of embankments with different fillings were compared.Findings reveal exponential attenuation of dynamic stress and acceleration with increasing depth.The acceleration and dynamic displacement exhibit U-shaped patterns in the culvert subsection and abrupt changes in the bridgehead subsection.The influence zone determined by the acceleration attenuation coefficient method,dynamic stress attenuation method,and stress diffusion angle method was 1.55 m,2.05 m,and 2.89 m,respectively.The maximum disparity in EDS occurs at the culvert subsection and bridge abutment,and the AVR ranges from 0 to 0.52 s^(-2).Moreover,94.1%attenuation of the dynamic stress occurred within the 1.5-meter foamed concrete embankment under the setting of 100 kN-60 km/h.展开更多
文摘Let M be a compact n-manifold of positive sectional curvature.We will review classical results on the fundamental group of M,a motivation on the c(n)-cyclic conjecture that the fundamental group of M contains a cyclic subgroup of index bounded above by c(n),a constant depending only on n,and we will survey partial results(up to date)on the c(n)-cyclic conjecture.
基金The National Natural Science Foundation of China(No.52338011,52378291)Young Elite Scientists Sponsorship Program by CAST(No.2022-2024QNRC0101).
文摘To overcome the limitations of low efficiency and reliance on manual processes in the measurement of geometric parameters for bridge prefabricated components,a method based on deep learning and computer vision is developed to identify the geometric parameters.The study utilizes a common precast element for highway bridges as the research subject.First,edge feature points of the bridge component section are extracted from images of the precast component cross-sections by combining the Canny operator with mathematical morphology.Subsequently,a deep learning model is developed to identify the geometric parameters of the precast components using the extracted edge coordinates from the images as input and the predefined control parameters of the bridge section as output.A dataset is generated by varying the control parameters and noise levels for model training.Finally,field measurements are conducted to validate the accuracy of the developed method.The results indicate that the developed method effectively identifies the geometric parameters of bridge precast components,with an error rate maintained within 5%.
基金supported by the National Natural Science Foundation of China under Grant No.62271043Ministry of Education of China under Grant No.8091B032123Beijing Natural Science Foundation under Grant No.L212029。
文摘Radar cross section(RCS)plays a critical role in modeling target scattering characteristics and enhancing the precision of target detection and localization in integrated sensing and communication(ISAC)systems.This paper investigates the human body RCS at 26 GHz via multiangle channel measurements under different clothing conditions.Based on calibrated electromagnetic(EM)parameters,the RCS characteristics of the human body in far-field conditions are analyzed using ray-tracing(RT)simulations.Some suggestions for the design of ISAC systems are also discussed.The results provide a solid theoretical foundation and practical reference for the modeling of target scattering characteristics for ISAC channels.
文摘BACKGROUND Intrathecal bupivacaine is the traditional anesthetic drug used in spinal anesthesia for caesarean sections(CSs),but ropivacaine has emerged as a potential alter-native.This meta-analysis compares the efficacy and safety of intrathecal hyper-baric bupivacaine vs hyperbaric ropivacaine for cesarean sections.AIM To systematically evaluate and compare the efficacy and safety of intrathecal hyperbaric bupivacaine and hyperbaric ropivacaine for spinal anesthesia in CSs.METHODS A thorough search of electronic databases was carried out to find pertinent randomized controlled trials(RCTs)comparing intrathecal hyperbaric ropi-vacaine and hyperbaric bupivacaine during CSs.PubMed,Cochrane database,Google Scholar,and Scopus were searched,and papers from January 2000 to January 2024 were deemed eligible and filtered using predetermined inclusion and exclusion criteria.Studies were assessed for methodological quality,and data were extracted for time to adequate anesthesia(sensory and motor blockade),duration of sensory and motor block,hemodynamic changes and side effect profile.The standardized mean difference with 95%CI was used for continuous data.Dichotomous variables were assessed using the Mantel-Haenszel test and the random effect model to compute the odds ratio.RESULTS Total 8 RCTs were selected from a pool of 119 search results for meta-analysis.The meta-analysis evaluated pooled effect sizes and assessed heterogeneity among the studies.The primary objective was to compare key outcomes to identify any significant variances in efficacy and safety profiles between two local anesthetics.The analysis revealed that the difference in the onset of sensory blockade between the two local anesthetics was statistically insignificant(P=0.1586).However,the onset of motor blockade appeared to be faster with bupivacaine(P=0.03589).Additionally,the regression of sensory and motor blockade occurred earlier in the ropivacaine group.Furthermore,the duration of the first analgesic effect was shorter with a significance level of P<0.05.Regarding side effects profile,including hypotension,nausea,and shivering,the study did not observe any significant differences between the two groups.CONCLUSION This meta-analysis offers insights into the effectiveness and safety of hyperbaric bupivacaine vs ropivacaine for cesarean sections.Hyperbaric ropivacaine had a comparable safety profile and faster regression of sensory and motor blockade than hyperbaric bupivacaine,perhaps aiding early mobilization of parturient and facilitating mother-child bonding.Choosing ropivacaine may offer benefits beyond efficacy for cesarean section patients and short surgical procedures.
文摘Background: Cesarean sections have become increasingly prevalent in both developed and developing nations. Nevertheless, postoperative complications, including surgical site infections (SSIs), remain a substantial concern that contributes to heightened morbidity and mortality. This study is designed to evaluate the frequency and key determining factors associated with surgical site infections following cesarean section procedures in a tertiary care hospital in Bangladesh. Materials and Methods: This observational cross-sectional study, conducted at the Gynecology Department of Dhaka Medical College Hospital, involved 100 patients aged 15 - 45 who had cesarean deliveries. Data was collected during hospitalization and post-discharge and analyzed to determine the prevalence and relationship between socio-demographic characteristics and surgical site infection. Results: Among the study participants, 14% developed surgical site infections following cesarean operations. More than half of these patients were under the age of 25, with a mean age of 24.45 ± 4.44 years. Surgical site infections were more prevalent in individuals over 30 years old (P-value Conclusion: Post-cesarean surgical site infections are notably prevalent among the participants in this study. Several risk factors have been identified, including age, body mass index (BMI), socioeconomic status, anemia, preterm delivery, personal hygiene practices, regular menstrual cycles, and adherence to antenatal check-ups. The implementation of an effective awareness program, coupled with updated antibiotic protocols, is crucial for significantly reducing the incidence of these infections.
基金Projects(51875411,52232013)supported by the National Natural Science Foundation of ChinaProject(19DZ2290400)supported by the Shanghai Professional Technical Service Platform Program,China。
文摘This study introduces a novel flow-through cowcatcher with integrated inlet and outlet channels as an aerodynamic noise mitigation strategy for the nose car of a high-speed train.The wall-adapting local eddy-viscosity large eddy simulation(WALE-LES)combined with the Ffowcs Williams-Hawkings(FW-H)acoustic analogy approach is employed to evaluate its impact on the aerodynamic and aeroacoustic characteristics of the leading bogie region.Compared with the conventional closed cowcatcher,results show that the flow-through structure suppresses the flow separation,promotes more stable vortex evolution within the bogie cavity,and reduces the spatial extent of high amplitude wall pressure fluctuations up to 40%,mitigating effectively the generation of aerodynamic noise.Semi anechoic wind tunnel experiments validate the simulation results and demonstrate that the sound pressure levels at the far field observers decrease by 0.4-0.6 dB(A)with the flow-through cowcatcher applied underneath the nose car.The dominant sound source around the leading bogie region is shrunk with intensity reduced about 1.0 dB(A).These findings confirm the effectiveness of the flow-through cowcatcher in reducing the aerodynamic noise produced from the leading bogie region,providing both theoretical insight and engineering guidance for structural optimization and low-noise design of the nose car in a high-speed train.
基金National Natural Science Foundation of China(grant number 82272563 to B.S.)National Science and Technology Major Project of the Ministry of Science and Technology of China(grant number 2023ZD0501202 to B.S.)+4 种基金institutional grants allocated to the National Institute of Biological Sciences,Beijing(NIBS)from the Chinese Ministry of Science and Technology,Beijing Municipal Commission of Science and Technology,and Tsinghua Universitythe support from China Pharmaceutical University(grant number 3150140001 to S.F.)National Natural Science Foundation of China(grant numbers 82203653 to S.F.,82371957 to L.W.,and 82371956 to X.C.)Beijing Municipal Public Welfare Development and Reform Pilot Project for Medical Research Institutes(grant number JYY2023-8 to X.C.)Research Grants Council of University Grants Committee Hong Kong(grant numbers 14113723,14108720,14121721,14202920,N_CUHK472/22,C7030-18G,T13-402/17-N,and AoE/M-402/20)。
文摘Tissue clearing combined with high-resolution confocal imaging is a cutting-edge approach for dissecting the three-dimensional(3D)architecture of tissues and deciphering cellular spatial interactions under physiological and pathological conditions.Deciphering the spatial interaction of leptin receptor-expressing(LepR^(+))stromal cells with other compartments in the bone marrow is crucial for a deeper understanding of the stem cell niche and the skeletal tissue.In this study,we introduce an optimized protocol for the 3D analysis of skeletal tissues,enabling the visualization of hematopoietic and stromal cells,especially LepR+stromal cells,within optically cleared bone hemisections.Our method preserves the 3D tissue architecture and is extendable to other hematopoietic sites such as calvaria and vertebrae.The protocol entails tissue fixation,decalcification,and cryosectioning to reveal the marrow cavity.Completed within approximately 12 days,this process yields highly transparent tissues that maintain genetically encoded or antibody-stained fluorescent signals.The bone hemisections are compatible with diverse antibody labeling strategies.Confocal microscopy of these transparent samples allows for qualitative and quantitative image analysis using Aivia or Bitplane Imaris software,assessing a spectrum of parameters.With proper storage,the fluorescent signal in the stained and cleared bone hemisections remains intact for at least 2–3 months.This protocol is robust,straightforward to implement,and highly reproducible,offering a valuable tool for tissue architecture and cellular interaction studies.
文摘Acute pulmonary edema is a leading cause of death in patients with preeclampsia.The authors reported a case of a pregnant woman at 25 weeks of gestation with severe preeclampsia complicated by pulmonary edema,who required an emergency cesarean section,posing a significant challenge to the anesthesiologist.The patient had developed Type 1 respiratory failure and needed supplemental oxygen with high-flow nasal oxygen.Due to contraindications for neuraxial anesthesia,the cesarean section was performed under general anesthesia.After induction of anesthesia,the patient’s hypoxemia worsened.Eventually,after treatment with fluid restriction,diuretics,and albumin,oxygenation improved gradually,and the procedure was performed successfully.Both the patient and the newborn had a good prognosis.
文摘Objective:The objective of this study is to determine the effect of nurse-led instructional video(NLIV)on anxiety,satisfaction,and recovery among mothers admitted for cesarean section(CS).Materials and Methods:A quasi-experimental design was carried out on the mothers scheduled for CS.Eighty participants were selected by a purposive sampling technique,which were divided(40 participants in each group)into an experimental group and a control group.Nurse-led informational video(NLIV)was shown to the experimental group,and routine care was provided for the control group.Modified hospital anxiety scale(HADS),scale for measuring maternal satisfaction in cesarean birth,and obstetric quality of recovery following cesarean delivery were used to assess anxiety,satisfaction,and recovery.Results:Both the experimental and control groups showed significant reductions in anxiety by the first postintervention day(P<0.001),with the experimental group experiencing a greater mean reduction(mean difference[MD]=4.37)than the control group(MD=3.35)but the intergroup difference was not statistically significant(P>0.05).The experimental group reported significantly higher satisfaction scores(175.55±9.42)on the 3rd postoperative day compared to the control group(151.93±14.89;P<0.001).Similarly,the experimental group’s recovery scores(79.90±6.24)were considerably higher than those of the control group(62.45±15.18;P<0.001).On the 3rd postintervention day,satisfaction was significantly associated with age(P<0.001),and recovery with gravidity(P<0.05).Conclusions:NLIV can be used in the preoperative period to reduce anxiety related to CS and to improve satisfaction and recovery after the CS.
文摘OBJECTIVE:To evaluate the clinical outcome of Traditional Chinese Medicine(TCM)syndrome differentiation combined with hysteroscopic treatment for uterine incision defect after cesarean section[previous cesarean scar defect(PCSD)]after cesarean section.METHODS:This is a single-center retrospective study.A total of 120 PCSD patients were enrolled from February 2022 to February 2023 and divided into two groups according to different treatment methods,the TCM group(n=60)and the control group(n=60).The control group was treated with hysteroscopy,and the TCM group combined TCM syndrome differentiation with hysteroscopy.Clinical outcome included menstrual scores,menstrual days,TCM symptom scores and intrauterine pregnancy recurrence rate was analyzed in two groups.RESULTS:The total response rate of the TCM group was significantly higher than that of the control group(P<0.05);after treatment,the menstrual scores,menstrual days and TCM symptoms of the two groups were decreased,and the menstrual scores,menstrual days and TCM symptoms of the TCM group were all lower than that of the control group(P<0.05);the recurrence rate of the TCM group was significantly lower than that of the control group(P<0.05).Follow-up results showed higher healing of incisional scar diverticulum in the TCM group than in the control group(P<0.05).The duration of menstruation before and after treatment,and the TCM group was better than the control group(P<0.05).CONCLUSION:TCM syndrome differentiation combined with hysteroscopy presented favorable outcome on the prolonged menstrual period of PCSD,which could significantly improve the recovery of menstruation,relief the symptoms of TCM,reduce the recurrence rate and accelerate wound healing.
文摘The purpose of this article is to explore the design of compound interchange interweaving sections on expressways.During the research phase,based on the support of the literature research method,the classification and development of the interchange system,as well as the design forms of the compound interchange interweaving section,were analyzed.Subsequently,based on the case method,the design of the compound interchange interweaving section of the ShiWu and ShiBai expressways in Shiyan,Hubei Province,was discussed,and a design scheme and scheme comparison were proposed.It is hoped that this article can provide technical reference and ideas for China’s road and bridge engineering teams,ensuring that the design results can not only guarantee the normal passage of traffic on the North Intersection Expressway but also ensure the straight-line traffic capacity of the main highway under the background of dislocation intersection,achieving smooth and safe transitions between different expressways.
基金supported by the National Key Research and Development Program of China(No.2022YFA1602502)the National Natural Science Foundation of China(No.12127804).
文摘The direct and dissociative ionizations of oxygen molecule are investigated experimen-tally by electron collision with energies from 350 eV to 8000 eV.The absolute ionization cross sections for the product ions(O_(2)^(2+),O_(2)^(2+)O^(+),O^(2+),and their total)and two Coulomb explosion channels(O^(+)+O^(+)and O^(2+)+O^(+))are obtained by putting the data of O^(2+)on the scale of Ar+from O_(2)and Ar gases mixed with a fixed relative flow ratio of 1:1.The experimental errors are assessed by taking uncertainties of various factors into account.The present absolute cross sections are well consistent with the previous data in the overlapped energy range below 1000 eV.
文摘Emergency cesarean section has always been a challenge for patients,surgeons,and anesthesiologists,as it endangers the safety of both parturients and fetuses.Obesity and hypertension are common among pregnant women,but severe obesity combined with refractory hypertension is very rare in clinical practice.The optimal anesthetic management strategy for obese pregnant women with a difficult airway and poorly controlled hypertension remains debatable.This report presents a 32-year-old woman with severe obesity and refractory hypertension at 36 weeks and 6 days of pregnancy.Owing to fetal heart rate abnormalities,she was scheduled for emergency cesarean section.Given the urgency of the fetal condition and the challenges posed by the patient's obesity for epidural puncture,the anesthesiologist opted for rapid sequence induction and tracheal intubation instead of intervertebral anesthesia.Short-acting antihypertensive medications were adminstrated preoperatively to control elevated blood pressure,and vasopressor agents were continuously infused during surgery to prevent severe hypotension induced by anesthetic drugs.The entire anesthesia and surgical procedure proceeded uneventfully,with no major adverse events observed.Both the patient and fetus achieved favorable outcomes.This case indicates that early anesthetic risk assessment and meticulous pre-delivery planning are paramount,necessitating personalized management of airway and hemodynamics to optimize outcomes in obese parturients.
基金funded by the Sum Nursing College,SOA University,Bhubaneswar,Odisha.
文摘Background:Postcesarean mothers often experience delayed lactogenesis II due to surgical stress and reduced oxytocin levels.Almond oil breast massage is a nonpharmacological intervention thought to enhance prolactin release and improve milk production.Objective:The objective of the study was to evaluate the effectiveness of almond oil massage on breast milk adequacy among primigravida lower segment cesarean section(LSCS)mothers.Materials and Methods:A randomized pretest-posttest control group design was conducted among 60 primigravida mothers post-LSCS,randomly assigned to experimental(n=30)and control(n=30)groups.The experimental group received three daily almond oil breast massages(5-10 mL;5 min/breast)for 3 days;controls received routine care.Breast milk adequacy was measured using a validated 16-item rating scale at baseline and day 4 post-intervention.Results:The mean breast milk adequacy scores increased from 29.30±1.915 to 39.80±1.690 in the experimental group(t=22.15,P<0.001).Control group change(29.93±2.132-30.27±2.116)was non-significant(t=0.776,P>0.05).Posttest scores between the two groups differed significantly between groups(t=19.282,P<0.001).Conclusion:Almond oil breast massage significantly enhances breast milk adequacy in post-LSCS mothers and can be integrated into routine postnatal nursing care.
基金supported by the National Natural Science Foundation of China(Nos.92476207,22288201)the Chinese Academy of Sciences(No.XBD0970202)+2 种基金the Innovation Program for Quantum Science and Technology(No.2021ZD0303300)the Shenzhen Science and Technology Innovation Committee(No.20220814164755002)the Guangdong Innovative&Entrepreneurial Research Team Program(Nos.2019ZT08L455,2019JC01X091).
文摘Here,we report the spin-orbit state-resolved differential cross sections(DCSs)for the prototype barrierless reaction S(^(1)D)+HD.Both product channels,namely H+SD(^(2)Π_(3/2,1/2))and D+SH(^(2)Π_(3/2,1/2)),were measured by high-resolution crossed molecular beam experiments.The DCSs of the two product channels show an overall forward-backward symmetry,in accordance with statistical model predictions.However,the DCSs for different spin-orbit manifolds show different preferences in forward or backward scattering directions at the same collision energies.This study reveals that,even though the title reaction proceeds via the long-lived complex mechanism,the spin-orbit coupling effects in the product channels play an important role in the reaction process.
基金supported by a grant from the National Natural Science Foundation of China(Grant No.42174156).
文摘Rock thin section description is an essential method for examining lithology,structure,diagenesis,and sedimentary environment,playing a pivotal role in fields such as geology,geophysics,and petroleum exploration.To overcome the challenges of subjectivity,low efficiency,and high expertise requirements in describing rock thin sections,we design a multimodal mapping network,ThinGPT,which aligns the feature spaces of the contrastive language-image pre-training(CLIP)and Generative Pre-trained(GPT-2)through network training.Given the high frequency of keywords and the structured sentence patterns in thin-section descriptions,we introduce a tokenization method tailored for rock thin sections.This approach enhances GPT-2's ability to effectively encode text and produce text feature vectors.We conducted comparative experiments using ThinGPT and other models on common sedimentary rocks.The results demonstrate that ThinGPT exhibits excellent potential in generating thin-section feature descriptions of rocks.Based on the geological expert evaluation criteria proposed in this study,ThinGPT achieved a score of 1.62 on the test set.For model complexity,ThinGPT avoids heavy initial training of large language models(LLMs).This training strategy makes the model lighter and improves the efficiency of rock thin section descriptions.As an innovative application of a LLMs within a lightweight architecture for rock thin section description,ThinGPT has significant implications for intelligent geology,geophysics,and petroleum exploration.
基金National Natural Science Foundation of China under Grant Nos.52078205 and 42172322Joint Fund for High-Speed Railway Basic Research under Grant No.U2268213the Postgraduate Scientific Research Innovation Project of Hunan Province under Grant Nos.QL20230104 and CX20240431。
文摘Foamed concrete is widely employed in highway transition sections,due to its lightweight,high-strength,and effective settlement control.It is crucial to investigate its dynamic response linked to the traffic-loading influence zone of embankment and transition section smoothness.In this study,in-situ truck tests were conducted in the road-culvert-bridge transition section to obtain the spatio-temporal response patterns.Based on the vertical response,the influence zone was ascertained.Depending on the longitudinal response,the smoothness was evaluated by equivalent dynamic stiffness(EDS)and acceleration variation rate(AVR).Furthermore,the response discrepancies of embankments with different fillings were compared.Findings reveal exponential attenuation of dynamic stress and acceleration with increasing depth.The acceleration and dynamic displacement exhibit U-shaped patterns in the culvert subsection and abrupt changes in the bridgehead subsection.The influence zone determined by the acceleration attenuation coefficient method,dynamic stress attenuation method,and stress diffusion angle method was 1.55 m,2.05 m,and 2.89 m,respectively.The maximum disparity in EDS occurs at the culvert subsection and bridge abutment,and the AVR ranges from 0 to 0.52 s^(-2).Moreover,94.1%attenuation of the dynamic stress occurred within the 1.5-meter foamed concrete embankment under the setting of 100 kN-60 km/h.
