Selective brain hypothermia is considered an effective treatment for neuronal injury after stroke,and avoids the complications of general hypothermia.However,the mechanisms by which selective brain hypothermia affects...Selective brain hypothermia is considered an effective treatment for neuronal injury after stroke,and avoids the complications of general hypothermia.However,the mechanisms by which selective brain hypothermia affects mitochondrial fission remain unknown.In this study,we investigated the effect of selective brain hypothermia on the expression of fission 1 (Fis1) protein,a key factor in the mitochondrial fission system,during focal cerebral ischemia/reperfusion injury.Sprague-Dawley rats were divided into four groups.In the sham group,the carotid arteries were exposed only.In the other three groups,middle cerebral artery occlusion was performed using the intraluminal filament technique.After 2 hours of occlusion,the filament was slowly removed to allow blood reperfusion in the ischemia/reperfusion group.Saline,at 4℃ and 37℃,were perfused through the carotid artery in the hypothermia and normothermia groups,respectively,followed by restoration of blood flow.Neurological function was assessed with the Zea Longa 5-point scoring method.Cerebral infarct volume was assessed by 2,3,5-triphenyltetrazolium chloride staining,and apoptosis was assessed by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling staining.Fis1 and cytosolic cytochrome c levels were assessed by western blot assay.Fis1 mRNA expression was assessed by quantitative reverse transcription-polymerase chain reaction.Mitochondrial ultrastructure was evaluated by transmission electron microscopy.Compared with the sham group,apoptosis,Fis1 protein and mRNA expression and cytosolic cytochrome c levels in the cortical ischemic penumbra and cerebral infarct volume were increased after reperfusion in the other three groups.These changes caused by cerebral ischemia/reperfusion were inhibited in the hypothermia group compared with the normothermia group.These findings show that selective brain hypothermia inhibits Fis1 expression and reduces apoptosis,thereby ameliorating focal cerebral ischemia/reperfusion injury in rats.Experiments were authorized by the Ethics Committee of Qingdao Municipal Hospital of China (approval No.2019008).展开更多
Background: The successful treatment of military combat casualties with penetrating injuries is significantly dependent on the time needed to get the patient to an adequate treatment facility. Profound hypothermia ind...Background: The successful treatment of military combat casualties with penetrating injuries is significantly dependent on the time needed to get the patient to an adequate treatment facility. Profound hypothermia induced suspended animation for delayed resuscitation(SADR) is a novel approach for inducing cardiac arrest and buying additional time for such injuries. However, the time used to safely administer circulatory arrest(CA) is controversial. The goal of this study was to evaluate the safety of hypothermia-induced SADR over 90 and 120 min time intervals.Methods: Sixteen male BAMA minipigs were randomized into two groups: CA90 group(90 min, n =8) and CA120 group(120 min, n =8). Cannulation of the right common carotid arteries and internal jugular veins was performed to establish cardiopulmonary bypass for each animal. Through the perfusion of cold organ preservation solution(OPS), cardioplegia and profound hypothermia(15℃) were induced. After CA, cardiopumonary bypass(CPB) was restarted, and the animals were gradually re-warmed and resuscitated. The animals were assisted with ventilators until spontaneous breathing was achieved. The index of hemodynamic perioperative serum chemistry values [alanine transaminase(ALT), aspartate aminotransferase(AST), creatinine(CR), lactic dehydrogenase(LDH) and troponin T(TnT)] and survival were observed from pre-operation to 7 days post-operation.Results: Fifteen animals were enrolled in the experiment, while 1 animal in CA120 group died from surgical error. All 8 animals in CA90 group recovered, with only 1 animal displaying mild disability. However, in CA120 group, only 2 animals survived with severe disability, and the other 5 animals died after 2 days post-operation. In CA90 group, the perioperative serum chemistry values increased at 1 day post-operation(ALT 84.43±18.65 U/L; AST 88.99±23.19 U/L; Cr 87.90±24.49μmol/L; LDH 1894.13±322.26 U/L; TnT 0.849±0.135 ng/ml) but decreased to normal or almost normal levels at 7 days post-operation(ALT 52.48±9.04 U/L; AST 75.23±21.46 U/L; Cr 82.69±18.41μmol/L; LDH 944.67±834.32 U/L; TnT 0.336±0.076 ng/ml).Conclusion: Profound hypothermia-induced SADR is an effective method for inducing cardiac arrest. Our results indicate that inducing CA for 90 min(at 15℃) is safer than doing so for 120 min. Our results indicate that 120 min of CA at 15℃ is dangerous and can result in high mortality and severe neurological complications. Further experimentation is needed to determine whether 120 min of CA at temperatures lower than 15℃ can lead to safe recovery.展开更多
AIM: To assess the safety of therapeutic hypothermia(TH) concerning arrhythmias we analyzed serial electrocardiograms(ECG) during TH.METHODS: All patients recovered from a cardiac arrest with Glasgow < 9 at admissi...AIM: To assess the safety of therapeutic hypothermia(TH) concerning arrhythmias we analyzed serial electrocardiograms(ECG) during TH.METHODS: All patients recovered from a cardiac arrest with Glasgow < 9 at admission were treated with induced mild TH to 32-34℃. TH was obtained with cool fluid infusion or a specific intravascular device. Twelvelead ECG before,during,and after TH,as well as ECG telemetry data was recorded in all patients. From a total of 54 patients admitted with cardiac arrest during the study period,47 patients had the 3 ECG and telemetry data available. ECG analysis was blinded and performed with manual caliper by two independent cardiologists from blinded copies of original ECG,recorded at 25 mm/s and 10 mm/m V. Coronary care unit staff analyzed ECG telemetry for rhythm disturbances. Variables measured in ECG were rhythm,RR,PR,QT and corrected QT(QTc by Bazett formula,measured in lead v2) intervals,QRS duration,presence of Osborn's J wave and U wave,as well as ST segment displacement and T wave amplitude in leads Ⅱ,v2 and v5.RESULTS: Heart rate went down an average of 19 bpm during hypothermia and increased again 16 bpm with rewarming(P < 0.0005,both). There was a nonsignificant prolongation of the PR interval during TH and a significant decrease with rewarming(P = 0.041). QRS duration significantly prolonged(P = 0.041) with TH and shortened back(P < 0.005) with rewarming. QTc interval presented a mean prolongation of 58 ms(P < 0.005) during TH and a significant shortening with rewarming of 22.2 ms(P = 0.017). Osborn or J wave was found in 21.3% of the patients. New arrhythmias occurred in 38.3% of the patients. Most frequent arrhythmia was non-sustained ventricular tachycardia(19.1%),followed by severe bradycardia or paced rhythm(10.6%),accelerated nodal rhythm(8.5%) and atrial fibrillation(6.4%). No life threatening arrhythmias(sustained ventricular tachycardia,polymorphic ventricular tachycardia or ventricular fibrillation) occurred during TH. CONCLUSION: A 38.3% of patients had cardiac arrhythmias during TH but without life-threatening arrhythmias. A concern may rise when inducing TH to patients with long QT syndrome.展开更多
Background:Ondansetron and hypothermia are both known to induce bradycardia or QT interval prolongation,thus placing affected patients at risk of cardiac arrest.Case Report:Herein,we report the case of a 97-year-old w...Background:Ondansetron and hypothermia are both known to induce bradycardia or QT interval prolongation,thus placing affected patients at risk of cardiac arrest.Case Report:Herein,we report the case of a 97-year-old woman who initially presented with confusion and hypothermia,and experienced severe bradycardia and asystolic cardiac arrest after a 4 mg intravenous ondansetron bolus injection.Conclusion:Ondansetron is associated with bradycardia and QTc prolongation,both of which might be further exacerbated by hypothermia.Clinicians should be aware that administering ondansetron in patients with hypothermia might further increase the risk of adverse cardiac events and eventual cardiac arrest.展开更多
This editorial addresses the growing concern of herb-induced liver injury(HILI),focusing on a unique case of Skullcap-induced HILI report.This editorial underscore the significant mortality rate linked to Skullcap-ind...This editorial addresses the growing concern of herb-induced liver injury(HILI),focusing on a unique case of Skullcap-induced HILI report.This editorial underscore the significant mortality rate linked to Skullcap-induced HILI,emphasizing the importance of vigilant monitoring and intervention.As herbal supplement usage rises,collaboration among clinicians and researchers is crucial to comprehend and address the complexities of HILI,particularly those involving Skullcap.展开更多
Objective To investigate the role of moderate h.vpothennia in the lung inflammation of rat acute lung injury induced by lipopolysaccharide(LPS). Methods A rat model of acute lung injury (ALl) was established by in-tin...Objective To investigate the role of moderate h.vpothennia in the lung inflammation of rat acute lung injury induced by lipopolysaccharide(LPS). Methods A rat model of acute lung injury (ALl) was established by in-tin-tracheal instillation of lipopolysaccharide ( 1.5 mg/kg, 0.5 ml) at 16 h after LPS ( 1.0 mg/kg) intraperitoneal adrninis-tmtion. Thirty-four male Sprague Dawley rats were randomly divided into four groups: control group, receiving saline only;LPS group, receiving LPS; hypothennia group, treated with hypothennia without LPS; LPS + hypothennia group, treated with LPS and cooled to 32.5℃-33.0℃ as PaO2/FiO2. was below 300 mmHg. Hemodynamics and blood gases were record-ed every hour throughout the study. Rats were killed 4 h after ALl, and lung lavage was performed to measure the tumor ne-crosis factor α(TNF-α), interleukin-6 (IL-6) and interleukin-10 (IL-10) concentrations in bronchoalveolar lavage fluid (BALF) by using enzyme-linked immunosorbent assay (ELISA). Results PaO2/FiO2 was significantly decreased and PaCO2 was increased in the LPS group as compared to their baseline values( P<0.01). Treatment with hypothermia inhib-ited the increase in PaCO2( P<0.05) but had no effect on PaO2/FiO2 in the presence of LPS. The administration of LPS significantly increased the concentrations of TNF-α, IL-6 and IL-10 in BALF as compared to the control experiment( P<0.05, P<0.01 ). Moderate hypothermia reduced the expressions of TNF-α and IL-6 ( P<0.01 ) but had no effect on the production of IL-10 ( P>0.05). Conclusion Moderate hypothermia significantly inhibits proinflammatory cytokine ex-pressions in lipopolysaccharide-induced acute lung injury.展开更多
Recent studies have mostly focused on engraftment of cells at the lesioned spinal cord,with the expectation that differentiated neurons facilitate recovery.Only a few studies have attempted to use transplanted cells a...Recent studies have mostly focused on engraftment of cells at the lesioned spinal cord,with the expectation that differentiated neurons facilitate recovery.Only a few studies have attempted to use transplanted cells and/or biomaterials as major modulators of the spinal cord injury microenvironment.Here,we aimed to investigate the role of microenvironment modulation by cell graft on functional recovery after spinal cord injury.Induced neural stem cells reprogrammed from human peripheral blood mononuclear cells,and/or thrombin plus fibrinogen,were transplanted into the lesion site of an immunosuppressed rat spinal cord injury model.Basso,Beattie and Bresnahan score,electrophysiological function,and immunofluorescence/histological analyses showed that transplantation facilitates motor and electrophysiological function,reduces lesion volume,and promotes axonal neurofilament expression at the lesion core.Examination of the graft and niche components revealed that although the graft only survived for a relatively short period(up to 15 days),it still had a crucial impact on the microenvironment.Altogether,induced neural stem cells and human fibrin reduced the number of infiltrated immune cells,biased microglia towards a regenerative M2 phenotype,and changed the cytokine expression profile at the lesion site.Graft-induced changes of the microenvironment during the acute and subacute stages might have disrupted the inflammatory cascade chain reactions,which may have exerted a long-term impact on the functional recovery of spinal cord injury rats.展开更多
Stem cell-based therapies have been proposed as a potential treatment for neural regeneration following closed head injury.We previously reported that induced neural stem cells exert beneficial effects on neural regen...Stem cell-based therapies have been proposed as a potential treatment for neural regeneration following closed head injury.We previously reported that induced neural stem cells exert beneficial effects on neural regeneration via cell replacement.However,the neural regeneration efficiency of induced neural stem cells remains limited.In this study,we explored differentially expressed genes and long non-coding RNAs to clarify the mechanism underlying the neurogenesis of induced neural stem cells.We found that H19 was the most downregulated neurogenesis-associated lnc RNA in induced neural stem cells compared with induced pluripotent stem cells.Additionally,we demonstrated that H19 levels in induced neural stem cells were markedly lower than those in induced pluripotent stem cells and were substantially higher than those in induced neural stem cell-derived neurons.We predicted the target genes of H19 and discovered that H19 directly interacts with mi R-325-3p,which directly interacts with Ctbp2 in induced pluripotent stem cells and induced neural stem cells.Silencing H19 or Ctbp2 impaired induced neural stem cell proliferation,and mi R-325-3p suppression restored the effect of H19 inhibition but not the effect of Ctbp2 inhibition.Furthermore,H19 silencing substantially promoted the neural differentiation of induced neural stem cells and did not induce apoptosis of induced neural stem cells.Notably,silencing H19 in induced neural stem cell grafts markedly accelerated the neurological recovery of closed head injury mice.Our results reveal that H19 regulates the neurogenesis of induced neural stem cells.H19 inhibition may promote the neural differentiation of induced neural stem cells,which is closely associated with neurological recovery following closed head injury.展开更多
Drug-induced liver injury(DILI)is a major problem in the United States,commonly leading to hospital admission.Diagnosing DILI is difficult as it is a diagnosis of exclusion requiring a temporal relationship between dr...Drug-induced liver injury(DILI)is a major problem in the United States,commonly leading to hospital admission.Diagnosing DILI is difficult as it is a diagnosis of exclusion requiring a temporal relationship between drug exposure and liver injury and a thorough work up for other causes.In addition,DILI has a very variable clinical and histologic presentation that can mimic many different etiologies of liver disease.Objective scoring systems can assess the probability that a drug caused the liver injury but liver biopsy findings are not part of the criteria used in these systems.This review will address some of the recent updates to the scoring systems and the role of liver biopsy in the diagnosis of DILI.展开更多
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
BACKGROUND Hypothermia during laparoscopic surgery in patients with multiple trauma is a significant concern owing to its potential complications.Machine learning models offer a promising approach to predict the occur...BACKGROUND Hypothermia during laparoscopic surgery in patients with multiple trauma is a significant concern owing to its potential complications.Machine learning models offer a promising approach to predict the occurrence of intraoperative hypothermia.AIM To investigate the value of machine learning model to predict hypothermia during laparoscopic surgery in patients with multiple trauma.METHODS This retrospective study enrolled 220 patients who were admitted with multiple injuries between June 2018 and December 2023.Of these,154 patients were allocated to a training set and the remaining 66 were allocated to a validation set in a 7:3 ratio.In the training set,53 cases experienced intraoperative hypothermia and 101 did not.Logistic regression analysis was used to construct a predictive model of intraoperative hypothermia in patients with polytrauma undergoing laparoscopic surgery.The area under the curve(AUC),sensitivity,and specificity were calculated.RESULTS Comparison of the hypothermia and non-hypothermia groups found significant differences in sex,age,baseline temperature,intraoperative temperature,duration of anesthesia,duration of surgery,intraoperative fluid infusion,crystalloid infusion,colloid infusion,and pneumoperitoneum volume(P<0.05).Differences between other characteristics were not significant(P>0.05).The results of the logistic regression analysis showed that age,baseline temperature,intraoperative temperature,duration of anesthesia,and duration of surgery were independent influencing factors for intraoperative hypothermia during laparoscopic surgery(P<0.05).Calibration curve analysis showed good consistency between the predicted occurrence of intraoperative hypothermia and the actual occurrence(P>0.05).The predictive model had AUCs of 0.850 and 0.829 for the training and validation sets,respectively.CONCLUSION Machine learning effectively predicted intraoperative hypothermia in polytrauma patients undergoing laparoscopic surgery,which improved surgical safety and patient recovery.展开更多
Induced abortion signifies that pregnancy has been tempered with. Abortion is the removal of an embryo or fetus weighing less than 500 grams from its mother. It can either be spontaneous (unprompted) or induced. Abort...Induced abortion signifies that pregnancy has been tempered with. Abortion is the removal of an embryo or fetus weighing less than 500 grams from its mother. It can either be spontaneous (unprompted) or induced. Abortion remains one of the leading causes of maternal deaths in developing countries with induced abortion being the key cause. In 2014 from January to August, 9 abortion related deaths occurred in Botswana. There are several reasons female students in tertiary institutions resort to seeking induced abortion which include the socio-demographics like age and socio-economic factors like financial instability. Parental fears, unintended pregnancy and pressure from the partner also force females to terminate pregnancy. Induced abortion has claimed many women’s lives especially in developing countries with very restrictive abortion laws like Botswana as women do not access safe abortion care services. The study intends to establish the determinants of induced abortion among female students in selected tertiary learning institutions in Gaborone City, Botswana. It concentrated primarily on determining the prevalence of induced abortion. This was a descriptive cross-sectional study using both quantitative and qualitative data collection techniques. Systematic random sampling technique was used to come up with 278 participants. Prior to commencement of data collection, all ethical and logistical prerequisites were satisfied. Informed consent was solicited from all the study participants and the purpose of the study was fully explained. A self-administered questionnaire was used to collect data. Microsoft Excel spread sheet was used to code, clean, and enter the data, which was then exported for analysis to the statistical package for social sciences version 24. Frequency distribution tables, percentages graphs, and pie charts were used to illustrate the descriptive information. The study revealed that prevalence of induced abortion among female students in Gaborone City is 7.9%. They even suggested that induced abortion be liberalized. Age was the only socio-demographic factor associated with induced abortion with p = 0.047 using Chi Square test χ<sup>2</sup> = 7.609, df = 3. The study findings concluded that female students resort to induced abortion as a result of pressure from both parents and male partners especially when the pregnancy is unintended. The study recommends that the abortion law in Botswana be made liberal to ease access to safe abortion care services. It also recommends that contraceptive commodities should consistently be available in public health facilities.展开更多
The subsurface fluid injection can cause pressure increase within faults,leading to earthquake occurrences.However,the factors controlling earthquake rupture due to pressure perturbation remain poorly understood.To re...The subsurface fluid injection can cause pressure increase within faults,leading to earthquake occurrences.However,the factors controlling earthquake rupture due to pressure perturbation remain poorly understood.To resolve this problem,we simulate the physical processes of earthquake nucleation and rupture on strike-slip faults perturbated by pressure migration based on the slip-weakening law.Multiple kinds of factors,including background stress,fluid injection rates,the area of the pressurized region,fault geometry,and fault friction coefficients,are considered in our simulations.Our simulation results reveal that the ratio of shear stress to normal stress rather than their absolute values controls the rupture behavior.With the large stress ratios,high injection rates,and large pressurized areas,earthquakes are prone to propagate as runaway ruptures.Additionally,faults with large aspect ratios of length to width are also favorable for causing runaway ruptures.In contrast,the factors of fault strike,dip angles and friction coefficients have minor influence on rupture behavior.展开更多
Blasting in surface mines aims to fragment rock masses to a proper size.However,flyrock is an undesirable effect of blasting that can result in human injuries.In this study,support vector regression(SVR)is combined wi...Blasting in surface mines aims to fragment rock masses to a proper size.However,flyrock is an undesirable effect of blasting that can result in human injuries.In this study,support vector regression(SVR)is combined with four algorithms:gravitational search algorithm(GSA),biogeography-based optimization(BBO),ant colony optimization(ACO),and whale optimization algorithm(WOA)for predicting flyrock in two surface mines in Iran.Additionally,three other methods,including artificial neural network(ANN),kernel extreme learning machine(KELM),and general regression neural network(GRNN),are employed,and their performances are compared to those of four hybrid SVR models.After modeling,the measured and predicted flyrock values are validated with some performance indices,such as root mean squared error(RMSE).The results revealed that the SVR-WOA model has the most optimal accuracy,with an RMSE of 7.218,while the RMSEs of the KELM,GRNN,SVR-GSA,ANN,SVR-BBO,and SVR-ACO models are 10.668,10.867,15.305,15.661,16.239,and 18.228,respectively.Therefore,combining WOA and SVR can be a valuable tool for accurately predicting flyrock distance in surface mines.展开更多
Magnesium and magnesium thin alloy films were deposited using a thermionic vacuum arc(TVA),which has multiple applications in the field of metallic electrodes for diodes and batteries or active corrosion protection.An...Magnesium and magnesium thin alloy films were deposited using a thermionic vacuum arc(TVA),which has multiple applications in the field of metallic electrodes for diodes and batteries or active corrosion protection.An improved laser-induced TVA(LTVA)method favors the crystallization processes of the deposited magnesium-based films because the interaction between laser and plasma discharge changes the thermal energy during photonic processes due to the local temperature variation.Plasma diagnosis based on current discharge measurements suggests an inelastic collision between the laser beam and the atoms from the plasma discharge.The morphology and surface properties of the obtained thin films differ between these two methods.While the amorphous character is dominant for TVA thin films,enabling a smooth surface,the LTVA method produces rough surfaces with prominent crystallinity,less hydrophobic character and lower surface energy.The smooth surfaces obtained by the TVA methods produce metallic electrodes with good electrical contact,ensuring better diodes and battery charge transport.Both methods allow uniform magnesium alloys to be obtained,but the laser used in the LTVA on the discharge plasma controls the added metal or element ratio.展开更多
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
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
BACKGROUND With an estimated 121 million abortions following unwanted pregnancies occurring worldwide each year,many countries are now committed to protecting women’s reproductive rights.AIM To analyze the impact of ...BACKGROUND With an estimated 121 million abortions following unwanted pregnancies occurring worldwide each year,many countries are now committed to protecting women’s reproductive rights.AIM To analyze the impact of emotional management and care on anxiety and contraceptive knowledge mastery in painless induced abortion(IA)patients.METHODS This study was retrospective analysis of 84 patients with IA at our hospital.According to different nursing methods,the patients were divided into a control group and an observation group,with 42 cases in each group.Degree of pain,rate of postoperative uterine relaxation,surgical bleeding volume,and postoperative bleeding volume at 1 h between the two groups of patients;nursing satisfaction;and mastery of contraceptive knowledge were analyzed.RESULTS After nursing,Self-Assessment Scale,Depression Self-Assessment Scale,and Hamilton Anxiety Scale scores were 39.18±2.18,30.27±2.64,6.69±2.15,respectively,vs 45.63±2.66,38.61±2.17,13.45±2.12,respectively,with the observation group being lower than the control group(P<0.05).Comparing visual analog scales,the observation group was lower than the control group(4.55±0.22 vs 3.23±0.41;P<0.05).The relaxation rate of the cervix after nursing,surgical bleeding volume,and 1-h postoperative bleeding volumes were 25(59.5),31.72±2.23,and 22.41±1.23,respectively,vs 36(85.7),42.39±3.53,28.51±3.34,respec tively,for the observation group compared to the control group.The observation group had a better nursing situation(P<0.05),and higher nursing satisfaction and contraceptive knowledge mastery scores compared to the control group(P<0.05).CONCLUSION The application of emotional management in postoperative care of IA has an ideal effect.展开更多
Boulder spacing in mountain rivers and near-wake flow zones within the boulder array is very useful for fish habitat and growth of aquatic organisms.The present study aims to investigate how the boulder array and spac...Boulder spacing in mountain rivers and near-wake flow zones within the boulder array is very useful for fish habitat and growth of aquatic organisms.The present study aims to investigate how the boulder array and spacing influence the near-bed flow structures in a gravel-bed stream.Boulders are staggered over a gravel-bed stream with three different inter-boulder spacing namely(a)large(b)medium and(c)small spacing.An acoustic Doppler velocimeter was used for flow measurements in a rectangular channel and the results were compared with those acquired from numerical simulation.The time-averaged velocity profiles at the near-wake flow zones of boulders experience maximum flow retardation which is an outcome of the boulder-induced form roughness.The ratio of velocity differences associated to form and skin roughness and its positive magnitude reveals the dominance of form roughness closest to the boulders.Form roughness computed is 1.75 to 2 times higher than the skin roughness at the near-wake flow region.In particular,the collective immobile boulders placed at different inter-boulder spacings developed high and low bed shear stresses closest to the boulders.The low bed shear stresses characterised by a secondary peak developed at the trough location of the boulders is attributed to the skin shear stress.Further,the spatial averaging of time-averaged flow quantities gives additional impetus to present an improved illustration of fluid shear stresses.The formation of form-induced shear stress is estimated to be 17%to 23%of doubleaveraged Reynolds shear stress and partially compensates for the damping of time-averaged Reynolds shear stress in the interfacial sub-layer.The quadrant analysis of spatial velocity fluctuations depicts that the form-induced shear stresses are dominant in the interfacial sub-layer and have no significance above the gravel-bed surface.展开更多
Defect engineering in transition metal oxides semiconductors(TMOs)is attracting considerable interest due to its potential to enhance conductivity by intentionally introducing defects that modulate the electronic stru...Defect engineering in transition metal oxides semiconductors(TMOs)is attracting considerable interest due to its potential to enhance conductivity by intentionally introducing defects that modulate the electronic structures of the materials.However,achieving a comprehensive understanding of the relationship between micro-structures and electromagnetic wave absorption capabilities remains elusive,posing a substantial challenge to the advancement of TMOs absorbers.The current research describes a process for the deposition of a MoO_(3)layer onto SiC nanowires,achieved via electro-deposition followed by high-temperature calcination.Subsequently,intentional creation of oxygen vacancies within the MoO_(3)layer was carried out,facilitating the precise adjustment of electromagnetic properties to enhance the microwave absorption performance of the material.Remarkably,the SiC@MO-t4 sample exhibited an excellent minimum reflection loss of-50.49 dB at a matching thickness of 1.27 mm.Furthermore,the SiC@MO-t6 sample exhibited an effective absorption bandwidth of 8.72 GHz with a thickness of 2.81 mm,comprehensively covering the entire Ku band.These results not only highlight the pivotal role of defect engineering in the nuanced adjustment of electromagnetic properties but also provide valuable insight for the application of defect engineering methods in broadening the spectrum of electromagnetic wave absor ption effectiveness.SiC@MO-t samples with varying concentrations of oxygen vacancies were prepared through in-situ etching of the SiC@MoO_(3)nanocomposite.The presence of oxygen vacancies plays a crucial role in adjusting the band gap and local electron distribution,which in turn enhances conductivity loss and induced polarization loss capacity.This finding reveals a novel strategy for improving the absorption properties of electromagnetic waves through defect engineering.展开更多
基金supported by the Natural Science Foundation of Shandong Province of China,No.ZR2015HM023(to MSW)the Science and Technology Plan Project of Qingdao City of China,No.19-6-1-50-nsh(to MSW)
文摘Selective brain hypothermia is considered an effective treatment for neuronal injury after stroke,and avoids the complications of general hypothermia.However,the mechanisms by which selective brain hypothermia affects mitochondrial fission remain unknown.In this study,we investigated the effect of selective brain hypothermia on the expression of fission 1 (Fis1) protein,a key factor in the mitochondrial fission system,during focal cerebral ischemia/reperfusion injury.Sprague-Dawley rats were divided into four groups.In the sham group,the carotid arteries were exposed only.In the other three groups,middle cerebral artery occlusion was performed using the intraluminal filament technique.After 2 hours of occlusion,the filament was slowly removed to allow blood reperfusion in the ischemia/reperfusion group.Saline,at 4℃ and 37℃,were perfused through the carotid artery in the hypothermia and normothermia groups,respectively,followed by restoration of blood flow.Neurological function was assessed with the Zea Longa 5-point scoring method.Cerebral infarct volume was assessed by 2,3,5-triphenyltetrazolium chloride staining,and apoptosis was assessed by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling staining.Fis1 and cytosolic cytochrome c levels were assessed by western blot assay.Fis1 mRNA expression was assessed by quantitative reverse transcription-polymerase chain reaction.Mitochondrial ultrastructure was evaluated by transmission electron microscopy.Compared with the sham group,apoptosis,Fis1 protein and mRNA expression and cytosolic cytochrome c levels in the cortical ischemic penumbra and cerebral infarct volume were increased after reperfusion in the other three groups.These changes caused by cerebral ischemia/reperfusion were inhibited in the hypothermia group compared with the normothermia group.These findings show that selective brain hypothermia inhibits Fis1 expression and reduces apoptosis,thereby ameliorating focal cerebral ischemia/reperfusion injury in rats.Experiments were authorized by the Ethics Committee of Qingdao Municipal Hospital of China (approval No.2019008).
基金supported by the Major Project for Equipment Development of PLA in 2013(ASY135001)the National High Technology Research and Development Program of China(2015AA020312)
文摘Background: The successful treatment of military combat casualties with penetrating injuries is significantly dependent on the time needed to get the patient to an adequate treatment facility. Profound hypothermia induced suspended animation for delayed resuscitation(SADR) is a novel approach for inducing cardiac arrest and buying additional time for such injuries. However, the time used to safely administer circulatory arrest(CA) is controversial. The goal of this study was to evaluate the safety of hypothermia-induced SADR over 90 and 120 min time intervals.Methods: Sixteen male BAMA minipigs were randomized into two groups: CA90 group(90 min, n =8) and CA120 group(120 min, n =8). Cannulation of the right common carotid arteries and internal jugular veins was performed to establish cardiopulmonary bypass for each animal. Through the perfusion of cold organ preservation solution(OPS), cardioplegia and profound hypothermia(15℃) were induced. After CA, cardiopumonary bypass(CPB) was restarted, and the animals were gradually re-warmed and resuscitated. The animals were assisted with ventilators until spontaneous breathing was achieved. The index of hemodynamic perioperative serum chemistry values [alanine transaminase(ALT), aspartate aminotransferase(AST), creatinine(CR), lactic dehydrogenase(LDH) and troponin T(TnT)] and survival were observed from pre-operation to 7 days post-operation.Results: Fifteen animals were enrolled in the experiment, while 1 animal in CA120 group died from surgical error. All 8 animals in CA90 group recovered, with only 1 animal displaying mild disability. However, in CA120 group, only 2 animals survived with severe disability, and the other 5 animals died after 2 days post-operation. In CA90 group, the perioperative serum chemistry values increased at 1 day post-operation(ALT 84.43±18.65 U/L; AST 88.99±23.19 U/L; Cr 87.90±24.49μmol/L; LDH 1894.13±322.26 U/L; TnT 0.849±0.135 ng/ml) but decreased to normal or almost normal levels at 7 days post-operation(ALT 52.48±9.04 U/L; AST 75.23±21.46 U/L; Cr 82.69±18.41μmol/L; LDH 944.67±834.32 U/L; TnT 0.336±0.076 ng/ml).Conclusion: Profound hypothermia-induced SADR is an effective method for inducing cardiac arrest. Our results indicate that inducing CA for 90 min(at 15℃) is safer than doing so for 120 min. Our results indicate that 120 min of CA at 15℃ is dangerous and can result in high mortality and severe neurological complications. Further experimentation is needed to determine whether 120 min of CA at temperatures lower than 15℃ can lead to safe recovery.
文摘AIM: To assess the safety of therapeutic hypothermia(TH) concerning arrhythmias we analyzed serial electrocardiograms(ECG) during TH.METHODS: All patients recovered from a cardiac arrest with Glasgow < 9 at admission were treated with induced mild TH to 32-34℃. TH was obtained with cool fluid infusion or a specific intravascular device. Twelvelead ECG before,during,and after TH,as well as ECG telemetry data was recorded in all patients. From a total of 54 patients admitted with cardiac arrest during the study period,47 patients had the 3 ECG and telemetry data available. ECG analysis was blinded and performed with manual caliper by two independent cardiologists from blinded copies of original ECG,recorded at 25 mm/s and 10 mm/m V. Coronary care unit staff analyzed ECG telemetry for rhythm disturbances. Variables measured in ECG were rhythm,RR,PR,QT and corrected QT(QTc by Bazett formula,measured in lead v2) intervals,QRS duration,presence of Osborn's J wave and U wave,as well as ST segment displacement and T wave amplitude in leads Ⅱ,v2 and v5.RESULTS: Heart rate went down an average of 19 bpm during hypothermia and increased again 16 bpm with rewarming(P < 0.0005,both). There was a nonsignificant prolongation of the PR interval during TH and a significant decrease with rewarming(P = 0.041). QRS duration significantly prolonged(P = 0.041) with TH and shortened back(P < 0.005) with rewarming. QTc interval presented a mean prolongation of 58 ms(P < 0.005) during TH and a significant shortening with rewarming of 22.2 ms(P = 0.017). Osborn or J wave was found in 21.3% of the patients. New arrhythmias occurred in 38.3% of the patients. Most frequent arrhythmia was non-sustained ventricular tachycardia(19.1%),followed by severe bradycardia or paced rhythm(10.6%),accelerated nodal rhythm(8.5%) and atrial fibrillation(6.4%). No life threatening arrhythmias(sustained ventricular tachycardia,polymorphic ventricular tachycardia or ventricular fibrillation) occurred during TH. CONCLUSION: A 38.3% of patients had cardiac arrhythmias during TH but without life-threatening arrhythmias. A concern may rise when inducing TH to patients with long QT syndrome.
文摘Background:Ondansetron and hypothermia are both known to induce bradycardia or QT interval prolongation,thus placing affected patients at risk of cardiac arrest.Case Report:Herein,we report the case of a 97-year-old woman who initially presented with confusion and hypothermia,and experienced severe bradycardia and asystolic cardiac arrest after a 4 mg intravenous ondansetron bolus injection.Conclusion:Ondansetron is associated with bradycardia and QTc prolongation,both of which might be further exacerbated by hypothermia.Clinicians should be aware that administering ondansetron in patients with hypothermia might further increase the risk of adverse cardiac events and eventual cardiac arrest.
文摘This editorial addresses the growing concern of herb-induced liver injury(HILI),focusing on a unique case of Skullcap-induced HILI report.This editorial underscore the significant mortality rate linked to Skullcap-induced HILI,emphasizing the importance of vigilant monitoring and intervention.As herbal supplement usage rises,collaboration among clinicians and researchers is crucial to comprehend and address the complexities of HILI,particularly those involving Skullcap.
文摘Objective To investigate the role of moderate h.vpothennia in the lung inflammation of rat acute lung injury induced by lipopolysaccharide(LPS). Methods A rat model of acute lung injury (ALl) was established by in-tin-tracheal instillation of lipopolysaccharide ( 1.5 mg/kg, 0.5 ml) at 16 h after LPS ( 1.0 mg/kg) intraperitoneal adrninis-tmtion. Thirty-four male Sprague Dawley rats were randomly divided into four groups: control group, receiving saline only;LPS group, receiving LPS; hypothennia group, treated with hypothennia without LPS; LPS + hypothennia group, treated with LPS and cooled to 32.5℃-33.0℃ as PaO2/FiO2. was below 300 mmHg. Hemodynamics and blood gases were record-ed every hour throughout the study. Rats were killed 4 h after ALl, and lung lavage was performed to measure the tumor ne-crosis factor α(TNF-α), interleukin-6 (IL-6) and interleukin-10 (IL-10) concentrations in bronchoalveolar lavage fluid (BALF) by using enzyme-linked immunosorbent assay (ELISA). Results PaO2/FiO2 was significantly decreased and PaCO2 was increased in the LPS group as compared to their baseline values( P<0.01). Treatment with hypothermia inhib-ited the increase in PaCO2( P<0.05) but had no effect on PaO2/FiO2 in the presence of LPS. The administration of LPS significantly increased the concentrations of TNF-α, IL-6 and IL-10 in BALF as compared to the control experiment( P<0.05, P<0.01 ). Moderate hypothermia reduced the expressions of TNF-α and IL-6 ( P<0.01 ) but had no effect on the production of IL-10 ( P>0.05). Conclusion Moderate hypothermia significantly inhibits proinflammatory cytokine ex-pressions in lipopolysaccharide-induced acute lung injury.
基金supported by the Stem Cell and Translation National Key Project,No.2016YFA0101403(to ZC)the National Natural Science Foundation of China,Nos.82171250 and 81973351(to ZC)+6 种基金the Natural Science Foundation of Beijing,No.5142005(to ZC)Beijing Talents Foundation,No.2017000021223TD03(to ZC)Support Project of High-level Teachers in Beijing Municipal Universities in the Period of 13th Five-year Plan,No.CIT&TCD20180333(to ZC)Beijing Municipal Health Commission Fund,No.PXM2020_026283_000005(to ZC)Beijing One Hundred,Thousand,and Ten Thousand Talents Fund,No.2018A03(to ZC)the Royal Society-Newton Advanced Fellowship,No.NA150482(to ZC)the National Natural Science Foundation of China for Young Scientists,No.31900740(to SL)。
文摘Recent studies have mostly focused on engraftment of cells at the lesioned spinal cord,with the expectation that differentiated neurons facilitate recovery.Only a few studies have attempted to use transplanted cells and/or biomaterials as major modulators of the spinal cord injury microenvironment.Here,we aimed to investigate the role of microenvironment modulation by cell graft on functional recovery after spinal cord injury.Induced neural stem cells reprogrammed from human peripheral blood mononuclear cells,and/or thrombin plus fibrinogen,were transplanted into the lesion site of an immunosuppressed rat spinal cord injury model.Basso,Beattie and Bresnahan score,electrophysiological function,and immunofluorescence/histological analyses showed that transplantation facilitates motor and electrophysiological function,reduces lesion volume,and promotes axonal neurofilament expression at the lesion core.Examination of the graft and niche components revealed that although the graft only survived for a relatively short period(up to 15 days),it still had a crucial impact on the microenvironment.Altogether,induced neural stem cells and human fibrin reduced the number of infiltrated immune cells,biased microglia towards a regenerative M2 phenotype,and changed the cytokine expression profile at the lesion site.Graft-induced changes of the microenvironment during the acute and subacute stages might have disrupted the inflammatory cascade chain reactions,which may have exerted a long-term impact on the functional recovery of spinal cord injury rats.
基金supported by the National Natural Science Foundation of China,Nos.82271397(to MG),82001293(to MG),82171355(to RX),81971295(to RX)and 81671189(to RX)。
文摘Stem cell-based therapies have been proposed as a potential treatment for neural regeneration following closed head injury.We previously reported that induced neural stem cells exert beneficial effects on neural regeneration via cell replacement.However,the neural regeneration efficiency of induced neural stem cells remains limited.In this study,we explored differentially expressed genes and long non-coding RNAs to clarify the mechanism underlying the neurogenesis of induced neural stem cells.We found that H19 was the most downregulated neurogenesis-associated lnc RNA in induced neural stem cells compared with induced pluripotent stem cells.Additionally,we demonstrated that H19 levels in induced neural stem cells were markedly lower than those in induced pluripotent stem cells and were substantially higher than those in induced neural stem cell-derived neurons.We predicted the target genes of H19 and discovered that H19 directly interacts with mi R-325-3p,which directly interacts with Ctbp2 in induced pluripotent stem cells and induced neural stem cells.Silencing H19 or Ctbp2 impaired induced neural stem cell proliferation,and mi R-325-3p suppression restored the effect of H19 inhibition but not the effect of Ctbp2 inhibition.Furthermore,H19 silencing substantially promoted the neural differentiation of induced neural stem cells and did not induce apoptosis of induced neural stem cells.Notably,silencing H19 in induced neural stem cell grafts markedly accelerated the neurological recovery of closed head injury mice.Our results reveal that H19 regulates the neurogenesis of induced neural stem cells.H19 inhibition may promote the neural differentiation of induced neural stem cells,which is closely associated with neurological recovery following closed head injury.
文摘Drug-induced liver injury(DILI)is a major problem in the United States,commonly leading to hospital admission.Diagnosing DILI is difficult as it is a diagnosis of exclusion requiring a temporal relationship between drug exposure and liver injury and a thorough work up for other causes.In addition,DILI has a very variable clinical and histologic presentation that can mimic many different etiologies of liver disease.Objective scoring systems can assess the probability that a drug caused the liver injury but liver biopsy findings are not part of the criteria used in these systems.This review will address some of the recent updates to the scoring systems and the role of liver biopsy in the diagnosis of DILI.
基金support from the OpenGeoSys communitypartially funded by the Prime Minister Research Fellowship,Ministry of Education,Government of India with the project number SB21221901CEPMRF008347.
文摘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.
文摘BACKGROUND Hypothermia during laparoscopic surgery in patients with multiple trauma is a significant concern owing to its potential complications.Machine learning models offer a promising approach to predict the occurrence of intraoperative hypothermia.AIM To investigate the value of machine learning model to predict hypothermia during laparoscopic surgery in patients with multiple trauma.METHODS This retrospective study enrolled 220 patients who were admitted with multiple injuries between June 2018 and December 2023.Of these,154 patients were allocated to a training set and the remaining 66 were allocated to a validation set in a 7:3 ratio.In the training set,53 cases experienced intraoperative hypothermia and 101 did not.Logistic regression analysis was used to construct a predictive model of intraoperative hypothermia in patients with polytrauma undergoing laparoscopic surgery.The area under the curve(AUC),sensitivity,and specificity were calculated.RESULTS Comparison of the hypothermia and non-hypothermia groups found significant differences in sex,age,baseline temperature,intraoperative temperature,duration of anesthesia,duration of surgery,intraoperative fluid infusion,crystalloid infusion,colloid infusion,and pneumoperitoneum volume(P<0.05).Differences between other characteristics were not significant(P>0.05).The results of the logistic regression analysis showed that age,baseline temperature,intraoperative temperature,duration of anesthesia,and duration of surgery were independent influencing factors for intraoperative hypothermia during laparoscopic surgery(P<0.05).Calibration curve analysis showed good consistency between the predicted occurrence of intraoperative hypothermia and the actual occurrence(P>0.05).The predictive model had AUCs of 0.850 and 0.829 for the training and validation sets,respectively.CONCLUSION Machine learning effectively predicted intraoperative hypothermia in polytrauma patients undergoing laparoscopic surgery,which improved surgical safety and patient recovery.
文摘Induced abortion signifies that pregnancy has been tempered with. Abortion is the removal of an embryo or fetus weighing less than 500 grams from its mother. It can either be spontaneous (unprompted) or induced. Abortion remains one of the leading causes of maternal deaths in developing countries with induced abortion being the key cause. In 2014 from January to August, 9 abortion related deaths occurred in Botswana. There are several reasons female students in tertiary institutions resort to seeking induced abortion which include the socio-demographics like age and socio-economic factors like financial instability. Parental fears, unintended pregnancy and pressure from the partner also force females to terminate pregnancy. Induced abortion has claimed many women’s lives especially in developing countries with very restrictive abortion laws like Botswana as women do not access safe abortion care services. The study intends to establish the determinants of induced abortion among female students in selected tertiary learning institutions in Gaborone City, Botswana. It concentrated primarily on determining the prevalence of induced abortion. This was a descriptive cross-sectional study using both quantitative and qualitative data collection techniques. Systematic random sampling technique was used to come up with 278 participants. Prior to commencement of data collection, all ethical and logistical prerequisites were satisfied. Informed consent was solicited from all the study participants and the purpose of the study was fully explained. A self-administered questionnaire was used to collect data. Microsoft Excel spread sheet was used to code, clean, and enter the data, which was then exported for analysis to the statistical package for social sciences version 24. Frequency distribution tables, percentages graphs, and pie charts were used to illustrate the descriptive information. The study revealed that prevalence of induced abortion among female students in Gaborone City is 7.9%. They even suggested that induced abortion be liberalized. Age was the only socio-demographic factor associated with induced abortion with p = 0.047 using Chi Square test χ<sup>2</sup> = 7.609, df = 3. The study findings concluded that female students resort to induced abortion as a result of pressure from both parents and male partners especially when the pregnancy is unintended. The study recommends that the abortion law in Botswana be made liberal to ease access to safe abortion care services. It also recommends that contraceptive commodities should consistently be available in public health facilities.
基金co-supported by the National Natural Science Foundation of China under Grants(42130101,42074007)the Fundamental Research Funds for the Central Universities under Grants 2042023kf1035。
文摘The subsurface fluid injection can cause pressure increase within faults,leading to earthquake occurrences.However,the factors controlling earthquake rupture due to pressure perturbation remain poorly understood.To resolve this problem,we simulate the physical processes of earthquake nucleation and rupture on strike-slip faults perturbated by pressure migration based on the slip-weakening law.Multiple kinds of factors,including background stress,fluid injection rates,the area of the pressurized region,fault geometry,and fault friction coefficients,are considered in our simulations.Our simulation results reveal that the ratio of shear stress to normal stress rather than their absolute values controls the rupture behavior.With the large stress ratios,high injection rates,and large pressurized areas,earthquakes are prone to propagate as runaway ruptures.Additionally,faults with large aspect ratios of length to width are also favorable for causing runaway ruptures.In contrast,the factors of fault strike,dip angles and friction coefficients have minor influence on rupture behavior.
文摘Blasting in surface mines aims to fragment rock masses to a proper size.However,flyrock is an undesirable effect of blasting that can result in human injuries.In this study,support vector regression(SVR)is combined with four algorithms:gravitational search algorithm(GSA),biogeography-based optimization(BBO),ant colony optimization(ACO),and whale optimization algorithm(WOA)for predicting flyrock in two surface mines in Iran.Additionally,three other methods,including artificial neural network(ANN),kernel extreme learning machine(KELM),and general regression neural network(GRNN),are employed,and their performances are compared to those of four hybrid SVR models.After modeling,the measured and predicted flyrock values are validated with some performance indices,such as root mean squared error(RMSE).The results revealed that the SVR-WOA model has the most optimal accuracy,with an RMSE of 7.218,while the RMSEs of the KELM,GRNN,SVR-GSA,ANN,SVR-BBO,and SVR-ACO models are 10.668,10.867,15.305,15.661,16.239,and 18.228,respectively.Therefore,combining WOA and SVR can be a valuable tool for accurately predicting flyrock distance in surface mines.
基金funded by CCDI-UEFISCDI project number PN-III-P2-2.1-PED-2021-0828,within PNCDI III and by the program Johannes Amos Comenius(cofunded by the European Union)QM4ST,project number CZ.02.01.01/00/22_008/0004572.
文摘Magnesium and magnesium thin alloy films were deposited using a thermionic vacuum arc(TVA),which has multiple applications in the field of metallic electrodes for diodes and batteries or active corrosion protection.An improved laser-induced TVA(LTVA)method favors the crystallization processes of the deposited magnesium-based films because the interaction between laser and plasma discharge changes the thermal energy during photonic processes due to the local temperature variation.Plasma diagnosis based on current discharge measurements suggests an inelastic collision between the laser beam and the atoms from the plasma discharge.The morphology and surface properties of the obtained thin films differ between these two methods.While the amorphous character is dominant for TVA thin films,enabling a smooth surface,the LTVA method produces rough surfaces with prominent crystallinity,less hydrophobic character and lower surface energy.The smooth surfaces obtained by the TVA methods produce metallic electrodes with good electrical contact,ensuring better diodes and battery charge transport.Both methods allow uniform magnesium alloys to be obtained,but the laser used in the LTVA on the discharge plasma controls the added metal or element ratio.
基金supported by the Taishan Scholars Program of Shandong Province,China(No.tsqn202306098)supported by the National Natural Science Foundations of China(No.52171282)the Shandong Provincial Key Research and Development Plan,China(No.2021ZLGX04).
文摘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.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.U2341211,62175136,12241408,and 12120101004)the Innovation Program for Quantum Science and Technology(Grant No.2023ZD0300902)+1 种基金the Fundamental Research Program of Shanxi Province(Grant No.202303021224007)the 1331 Project of Shanxi Province.
文摘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.
基金The study was reviewed and approved by Wuhan Maternal and Child Healthcare Hospital(Approval No.2024-013).
文摘BACKGROUND With an estimated 121 million abortions following unwanted pregnancies occurring worldwide each year,many countries are now committed to protecting women’s reproductive rights.AIM To analyze the impact of emotional management and care on anxiety and contraceptive knowledge mastery in painless induced abortion(IA)patients.METHODS This study was retrospective analysis of 84 patients with IA at our hospital.According to different nursing methods,the patients were divided into a control group and an observation group,with 42 cases in each group.Degree of pain,rate of postoperative uterine relaxation,surgical bleeding volume,and postoperative bleeding volume at 1 h between the two groups of patients;nursing satisfaction;and mastery of contraceptive knowledge were analyzed.RESULTS After nursing,Self-Assessment Scale,Depression Self-Assessment Scale,and Hamilton Anxiety Scale scores were 39.18±2.18,30.27±2.64,6.69±2.15,respectively,vs 45.63±2.66,38.61±2.17,13.45±2.12,respectively,with the observation group being lower than the control group(P<0.05).Comparing visual analog scales,the observation group was lower than the control group(4.55±0.22 vs 3.23±0.41;P<0.05).The relaxation rate of the cervix after nursing,surgical bleeding volume,and 1-h postoperative bleeding volumes were 25(59.5),31.72±2.23,and 22.41±1.23,respectively,vs 36(85.7),42.39±3.53,28.51±3.34,respec tively,for the observation group compared to the control group.The observation group had a better nursing situation(P<0.05),and higher nursing satisfaction and contraceptive knowledge mastery scores compared to the control group(P<0.05).CONCLUSION The application of emotional management in postoperative care of IA has an ideal effect.
文摘Boulder spacing in mountain rivers and near-wake flow zones within the boulder array is very useful for fish habitat and growth of aquatic organisms.The present study aims to investigate how the boulder array and spacing influence the near-bed flow structures in a gravel-bed stream.Boulders are staggered over a gravel-bed stream with three different inter-boulder spacing namely(a)large(b)medium and(c)small spacing.An acoustic Doppler velocimeter was used for flow measurements in a rectangular channel and the results were compared with those acquired from numerical simulation.The time-averaged velocity profiles at the near-wake flow zones of boulders experience maximum flow retardation which is an outcome of the boulder-induced form roughness.The ratio of velocity differences associated to form and skin roughness and its positive magnitude reveals the dominance of form roughness closest to the boulders.Form roughness computed is 1.75 to 2 times higher than the skin roughness at the near-wake flow region.In particular,the collective immobile boulders placed at different inter-boulder spacings developed high and low bed shear stresses closest to the boulders.The low bed shear stresses characterised by a secondary peak developed at the trough location of the boulders is attributed to the skin shear stress.Further,the spatial averaging of time-averaged flow quantities gives additional impetus to present an improved illustration of fluid shear stresses.The formation of form-induced shear stress is estimated to be 17%to 23%of doubleaveraged Reynolds shear stress and partially compensates for the damping of time-averaged Reynolds shear stress in the interfacial sub-layer.The quadrant analysis of spatial velocity fluctuations depicts that the form-induced shear stresses are dominant in the interfacial sub-layer and have no significance above the gravel-bed surface.
基金supported by the National Natural Science Foundation of China under Grant Nos. 52072196, 52002200, 52102106, 52202262, 22379081, 22379080Major Basic Research Program of Natural Science Foundation of Shandong Province under Grant No. ZR2020ZD09+1 种基金the Natural Science Foundation of Shandong Province under Grant Nos. ZR2020QE063, ZR2022ME090, ZR2023QE059. Moreoversupported by the Visiting Scholar Fellowship Funding for Teachers in Shandong Province’s General Undergraduate Institutions
文摘Defect engineering in transition metal oxides semiconductors(TMOs)is attracting considerable interest due to its potential to enhance conductivity by intentionally introducing defects that modulate the electronic structures of the materials.However,achieving a comprehensive understanding of the relationship between micro-structures and electromagnetic wave absorption capabilities remains elusive,posing a substantial challenge to the advancement of TMOs absorbers.The current research describes a process for the deposition of a MoO_(3)layer onto SiC nanowires,achieved via electro-deposition followed by high-temperature calcination.Subsequently,intentional creation of oxygen vacancies within the MoO_(3)layer was carried out,facilitating the precise adjustment of electromagnetic properties to enhance the microwave absorption performance of the material.Remarkably,the SiC@MO-t4 sample exhibited an excellent minimum reflection loss of-50.49 dB at a matching thickness of 1.27 mm.Furthermore,the SiC@MO-t6 sample exhibited an effective absorption bandwidth of 8.72 GHz with a thickness of 2.81 mm,comprehensively covering the entire Ku band.These results not only highlight the pivotal role of defect engineering in the nuanced adjustment of electromagnetic properties but also provide valuable insight for the application of defect engineering methods in broadening the spectrum of electromagnetic wave absor ption effectiveness.SiC@MO-t samples with varying concentrations of oxygen vacancies were prepared through in-situ etching of the SiC@MoO_(3)nanocomposite.The presence of oxygen vacancies plays a crucial role in adjusting the band gap and local electron distribution,which in turn enhances conductivity loss and induced polarization loss capacity.This finding reveals a novel strategy for improving the absorption properties of electromagnetic waves through defect engineering.