This paper studies certain estimates for the lower bound of distance between unitary orbits of normal elements.We show that the distance between unitary orbits of normal elements of simple C^(*)-algebras of tracial ra...This paper studies certain estimates for the lower bound of distance between unitary orbits of normal elements.We show that the distance between unitary orbits of normal elements of simple C^(*)-algebras of tracial rank no more than k has a lower bound.Furthermore,if k≤1 and normal elements are commuting,then the lower bound will be better.Another result establishes a connection involving the spectrum distance operator Dc between a C^(*)-algebra of stable rank one C^(*)-algebra and its hereditary C^(*)-subalgebra.展开更多
The development of brain-computer interfaces(BCI)based on motor imagery(MI)has greatly improved patients’quality of life with movement disorders.The classification of upper limb MI has been widely studied and applied...The development of brain-computer interfaces(BCI)based on motor imagery(MI)has greatly improved patients’quality of life with movement disorders.The classification of upper limb MI has been widely studied and applied in many fields,including rehabilitation.However,the physiological representations of left and right lower limb movements are too close and activated deep in the cerebral cortex,making it difficult to distinguish their features.Therefore,classifying lower limbs motor imagery is more challenging.In this study,we propose a feature extraction method based on functional connectivity,which utilizes phase-locked values to construct a functional connectivity matrix as the features of the left and right legs,which can effectively avoid the problem of physiological representations of the left and right lower limbs being too close to each other during movement.In addition,considering the topology and the temporal characteristics of the electroencephalogram(EEG),we designed a temporal-spatial convolutional network(TSGCN)to capture the spatiotemporal information for classification.Experimental results show that the accuracy of the proposed method is higher than that of existing methods,achieving an average classification accuracy of 73.58%on the internal dataset.Finally,this study explains the network mechanism of left and right foot MI from the perspective of graph theoretic features and demonstrates the feasibility of decoding lower limb MI.展开更多
BACKGROUND The therapeutic role of neurodynamic mobilization in improving lower limb function in patients with mild post-traumatic knee osteoarthritis remains poorly understood.AIM To further elucidate the role of neu...BACKGROUND The therapeutic role of neurodynamic mobilization in improving lower limb function in patients with mild post-traumatic knee osteoarthritis remains poorly understood.AIM To further elucidate the role of neurodynamic mobilization in facilitating knee joint functional recovery.METHODS Thirty-two patients with post-traumatic knee osteoarthritis treated at Chonghua Hospital of Traditional Chinese Medicine(Guilin)from March 2024 to August 2025 were randomly assigned to a control group(n=16)or an intervention group(n=16).Both groups received eight weeks of conventional treatment;and the intervention group additionally underwent neurodynamic mobilization.Outcomes including pain assessed by the visual analogue scale,active range of motion,Lysholm score,stork stand test,single hop test,and Y-balance test were assessed before and after the intervention.RESULTS There were no significant differences between the two groups in baseline characteristics,including gender,age,body mass index,or surgical side(P>0.05).Two-way repeated-measures analysis of variance demonstrated significant time×group interaction effects for the visual analogue scale score(F=13.364,P<0.05),Lysholm knee score(F=20.385,P<0.05),stork stand test(F=103.756,P<0.05),and Y-balance test score(F=8.089,P<0.05).CONCLUSION Neurodynamic mobilization effectively reduces pain,improves knee function,and enhances lower limb balance in patients with mild post-traumatic knee osteoarthritis.展开更多
Background:Prostate cancer is a common malignancy,with many men on active surveillance for localized,low-risk disease also experiencing lower urinary tract symptoms(LUTS)from benign prostatic hyperplasia(BPH).Water Va...Background:Prostate cancer is a common malignancy,with many men on active surveillance for localized,low-risk disease also experiencing lower urinary tract symptoms(LUTS)from benign prostatic hyperplasia(BPH).Water Vapor Thermal Therapy(WVTT)is a minimally invasive BPH treatment,but its safety and efficacy in this setting are unclear.Case Description:We report three men with localized PCa on active surveillance who underwent WVTT for LUTS.Conclusions:WVTT appears safe and potentially effective in treating LUTS,especially in those with lower-risk disease and smaller prostate volumes.Further research is needed to confirm safety,efficacy,and optimal patient selection.展开更多
This research presents a Human Lower Limb Activity Recognition(HLLAR)system that identifies specific activities and predicts the angles of the knees simultaneously,based on the EMG signals.The HLLAR systems streamline...This research presents a Human Lower Limb Activity Recognition(HLLAR)system that identifies specific activities and predicts the angles of the knees simultaneously,based on the EMG signals.The HLLAR systems streamlines the research on the lower limb activities.The HILLAR model includes Discrete Hermite Wavelets Transform-based Synchrosqueezing(DHWTS),Deep Two-Layer Multiscale Convolutional Neural Network(DTLMCNN),and Generalized Regression Neural Network(GRNN)as feature extraction,activity recognition,and knee angle prediction respectively.Electromyography signal-based automatic lower limb activity detection is crucial to rehabilitation and human movement analysis.Yet several of these methods face issues in feature extraction in complex data,overlapping signals,extraction of crucial parameters,and adaptation constraints.This research aims classify lower limb activities and predict knee joint angles from electromy-ography signals using HILLAR model.The model is validated on two datasets,comprising 26 subjects performing three classes of activities:walking,standing,and sitting.The proposed model obtained a classification accuracy of 99.95%,along with significant achievements in precision(99.93%),recall(99.91%),and F1-score(99.93%).The generalized regression neural network predicted angles of the knee joint with a root mean squared error of 1.25%.Robustness is demonstrated through consistent results in five-fold cross-validation and statistical significance testing(p-value=0.004,McNemar's test).Additionally,the proposed model showed superior performance over baseline methods by reducing error rates by 18%and decreasing processing time to 0.98 s.展开更多
Usually, only the Cramer-Rao lower bound （CRLB） of single target is taken into consideration in the state estimate of passive tracking systems. As for the case of multitarget, there are few works done due to its com...Usually, only the Cramer-Rao lower bound （CRLB） of single target is taken into consideration in the state estimate of passive tracking systems. As for the case of multitarget, there are few works done due to its complexity. The recursion formula of the posterior Cramer-Rao lower bound （PCRLB） in multitarget bearings-only tracking with the three kinds of data association is presented. Meanwhile, computer simulation is carried out for data association. The final result shows that the accuracy probability of data association has an important impact on the PCRLB.展开更多
Objective This study aims to analyze the burden of lower respiratory infections in Chinese elderly people aged 70 and above.Methods This study utilized Global Burden of Disease(GBD)1990-2050 prediction data to analyze...Objective This study aims to analyze the burden of lower respiratory infections in Chinese elderly people aged 70 and above.Methods This study utilized Global Burden of Disease(GBD)1990-2050 prediction data to analyze changes in mortality rates and disability-adjusted life year(DALY)rates for lower respiratory infections in the elderly population(aged 70 and above)in China from 1990 to 2050.It also discusses future trends in the burden of lower respiratory infections(LRI)in China under different scenarios.Results According to GBD predictions,the burden of lower respiratory infections in the elderly aged 70 years and above in China is lower than the global average.The burden has been decreasing from 1990 to 2020,but is projected to increase from 2020 to 2050.Scenario-based predictions suggest that,under scenarios involving improvements in nutrition and vaccination,the burden of lower respiratory infections in the elderly in China is expected to be the lowest in 2050.Conclusion This study indicates that the burden of lower respiratory infections in elderly people aged 70 years and above in China remains a significant public health issue and may worsen.The government should consider strengthening the preventive measures and management strategies for respiratory infections in the elderly population.展开更多
Understanding the relationships between human activities and hydrological processes is critical for sustainable water resources management, especially under the threat of increasing climate extremes. China's Lower...Understanding the relationships between human activities and hydrological processes is critical for sustainable water resources management, especially under the threat of increasing climate extremes. China's Lower Yellow River(LYR) region is one of the world's most water-scarce and human-impacted areas, yet comprehensive information on its water resources is lacking. This study adopted a water resources system(WRS) analytical framework to investigate the water crisis facing the region. The findings reveal that over the last decade, the system's resilience has been undermined by the combined impacts of climate aridification and intensified human interference. Specifically, a delicate balance between natural groundwater depletion and irrigation replenishment has been disrupted by a series of drought events since 2012. Increased groundwater extraction during droughts, coupled with an imbalanced allocation of surface water resources, has led to a persistent decline in water storage that has continued even after the droughts have ended. To mitigate future climate risks in the LYR,we recommend implementing more adaptive strategies, such as flexible water regulation policies and combined surface-groundwater management. Lessons from the LYR have important implications for other regions facing water resource challenges.展开更多
BACKGROUND Most patients who were included in previous studies on achalasia had increased lower esophageal sphincter(LES)pressure.Peroral endoscopic myotomy(POEM)has been confirmed to be effective at relieving the cli...BACKGROUND Most patients who were included in previous studies on achalasia had increased lower esophageal sphincter(LES)pressure.Peroral endoscopic myotomy(POEM)has been confirmed to be effective at relieving the clinical symptoms of achalasia associated with increased LES pressure.AIM To identify the safety and efficacy of POEM for patients with normal LES integrated relaxation pressure(LES-IRP).METHODS The clinical data of patients who underwent POEM successfully in The First Medical Center of Chinese PLA General Hospital were retrospectively analyzed.A total of 481 patients who underwent preoperative high-resolution manometry(HRM)at our hospital were ultimately included in this research.According to the HRM results,the patients were divided into two groups:71 patients were included in the normal LES-IRP group(LES-IRP<15 mmHg)and 410 patients were included in the increased LES-IRP group(LES-IRP≥15 mmHg).Clinical characteristics,procedure-related parameters,adverse events,and outcomes were compared between the two groups to evaluate the safety and efficacy of POEM for patients with normal LES-IRP.RESULTS Among the 481 patients included in our study,209 were males and 272 were females,with a mean age of 44.2 years.All patients underwent POEM without severe adverse events.The median pre-treatment Eckardt scores of the normal LES-IRP and increased LES-IRP groups were 7.0 and 7.0(P=0.132),respectively,decreasing to 1.0 and 1.0 post-treatment(P=0.572).The clinical success rate of the normal LES-IRP group was 87.3%(62/71),and that of the increased LES-IRP group was 91.2%(374/410)(P=0.298).Reflux symptoms were measured by the GerdQ questionnaire,and the percentages of patients with GerdQ scores≥9 in the normal LES-IRP and increased LES-IRP groups were 8.5%and 10.7%,respectively(P=0.711).After matching,the rates of clinical success and the rates of GerdQ score≥9 were not significantly different between the two groups.CONCLUSION Our results suggest that POEM is safe and effective for achalasia and patients with normal LES-IRP.In addition,in patients with normal LES-IRP,compared with those with increased LES-IRP,POEM was not associated with a greater incidence of reflux symptoms.展开更多
Introduction: Foreign bodies (FB) in the lower airways (LAs) constitute a potentially life-threatening emergency requiring immediate management. The objective of our study was to describe the patient pathway and manag...Introduction: Foreign bodies (FB) in the lower airways (LAs) constitute a potentially life-threatening emergency requiring immediate management. The objective of our study was to describe the patient pathway and management of foreign bodies in the lower airways. Methodology: This was a descriptive study with retrospective data collection conducted over a 6-year period (January 1, 2014, to December 31, 2019) in the ENT and Head and Neck Surgery Department of Donka National Hospital. Results: We observed a prevalence of 1.79%. The average age was 5.71 years, with a sex ratio of 1.2. However, 82.61% of the cases originated from rural areas. We noted that 78.83% of patients were referred after visiting 1 to 2 healthcare facilities (75.36%). The consultation delay was 3 days. Penetration syndrome was present in 98.56% of cases. The foreign body incidents occurred during play in 54.84% and during meals in 29.09% of cases. Radiographs were performed in 93.9% of cases. Endoscopy was used for both diagnostic and therapeutic purposes in all patients. The foreign bodies were located in the trachea (37.68%), larynx (26.08%), and bronchi (21.73%). Non-organic foreign bodies were predominant (52.17%). Postoperative outcomes were uncomplicated in 95.98% of cases, and the lethality rate was 2.85%. Conclusion: The pathway of patients with foreign bodies in the airways remains unpredictable in our context due to parental hesitations. Early management reduces morbidity and mortality rates.展开更多
Varicose veins of the lower limbs are a cosmopolitan condition, thought to be rare in Africa but widespread in Europe. The aim of this study is to analyze the indications and evaluate the results of surgical managemen...Varicose veins of the lower limbs are a cosmopolitan condition, thought to be rare in Africa but widespread in Europe. The aim of this study is to analyze the indications and evaluate the results of surgical management of varicose pathology of the IM in Dakar. We enrolled 280 patients, with a mean age of 36 and a sex ratio of 2. Factors favouring venous disease were dominated by prolonged orthostatism and multiparity. The average consultation time was 6 years. The reasons for consultation were functional manifestations, progressive complications and aesthetics. The venous trunks concerned were the great saphenous vein (GSV) in 58.9% of cases, the small saphenous vein (SSV) in 29% of cases, perforating veins and varicose veins were unsystematized in 28.5% of cases. Surgery was performed under spinal anaesthesia. Surgical procedures were dominated by stripping of the GSV, crossectomy of the SSV and staged ligations. One patient developed meningismus immediately after the operation. Average follow-up was 2 years. Mortality was null.展开更多
Purpose: To evaluate open lower limb trauma management in children. Me-thod: We conducted a twelve-month cross-sectional prospective study. Results: Open trauma of lower limb had 7.9% of hospital frequency. Mean age w...Purpose: To evaluate open lower limb trauma management in children. Me-thod: We conducted a twelve-month cross-sectional prospective study. Results: Open trauma of lower limb had 7.9% of hospital frequency. Mean age was 8 years with a sex ratio of 2.45. In 68.4% of cases, trauma occurred in road traffic accidents. Average consultation time was 2.4 hours. Trauma mainly affected the leg in 39.5% of cases, and the thigh in 34.2%. Soft tissue wounds occurred in 52.6% of cases, and open fractures in 47.4%. Average response time was one hour. Wound trimming and suturing were performed in 76.3% of cases and combined with bone nailing in 15.8%. The outcome was favorable in 92.1% of cases. Average hospital stay was 4.37 days. Conclusion: Open trauma to the lower limb is a frequent and occurs mainly in road traffic accidents. Management was early, with a favorable outcome for most patients and a short hospital stay.展开更多
Here we report a left cheek plate of Psarolepis,a postparietal shield of Youngolepis,a skull of Diabolepis,and a scale of Styloichthys from the Lianhuashan and Nahkaoling formations(Lochkovian,Lower Devonian)of Nannin...Here we report a left cheek plate of Psarolepis,a postparietal shield of Youngolepis,a skull of Diabolepis,and a scale of Styloichthys from the Lianhuashan and Nahkaoling formations(Lochkovian,Lower Devonian)of Nanning,Guangxi.This marks the first report of Diabolepis and Styloichthys beside Qujing,Yunnan,and the latest occurrence of Psarolepis to date.The fossil community displays significant similarities to the Xujiachong Assemblage,and provides new data for the Lower Devonian stratigraphic correlation between southwestern China and northern Vietnam.Given the latest dating constraint based on the conodont evidence,we regard that the Xujiachong Assemblage has a much longer range than previously supposed,extending from the latest Lochkovian to the end of Pragian.We propose that the transition of the Nahkaoling and Lianhuashan formations in Nanning might correspond to the Guijiatun Formation in Qujing.The relatively large size of fish individuals from Guangxi is probably attributed to the increase in the oxygen content of the ocean.展开更多
Shale gas is abundant in the Paleozoic of the Yangtze Platform,and several high-yield shale gas fields have been built in the Upper Yangtze Platform,China.The Permian of the South Yellow Sea Basin(SYSB)in the Lower Ya...Shale gas is abundant in the Paleozoic of the Yangtze Platform,and several high-yield shale gas fields have been built in the Upper Yangtze Platform,China.The Permian of the South Yellow Sea Basin(SYSB)in the Lower Yangtze area is considered a potential target for shale gas exploration;however,the fundamental geological conditions of shale gas have not been studied.Based on the first whole-cored scientific drilling borehole(CSDP-2)in the SYSB,detailed tests involving petrology,organic geochemistry,and reservoir physical properties were conducted to evaluate the shale gas potential of the Lower Permian.The Lower Permian is dominated by organic-rich siliceous,clay,and clay-mixed shales.The average total organic carbon content is 5.99%,and the organic matter is mainly type Ⅱ_(1)−Ⅱ_(2),which has entered the high-over mature evolution stage.The pore types of organic-rich shales mainly include organic pores,dissolution pores,and intergranular pores,of which the meso-/macropores are well developed.The average porosity is 3.04%,and the total specific surface area and pore volume are 3.47 m^(2)/g and 7.21×10^(−3) cm^(3)/g,respectively.The average Langmuir volume obtained from the methane adsorption isotherms is 2.70 cm^(3)/g,and methane is mainly adsorbed in the meso-/macropores.The lower Permian shales are rich in methane as indicated by gas logging results,with an average content of 7.3%,which can reach up to 65.9%.A comparison of the study area with typical shale gas fields shows that the Lower Permian is brittle and shallowly buried and has a high potential for shale gas exploration and low-cost development.The depression areas of the SYSB are overlain by thick Mesozoic-Cenozoic sediments,show higher organic matter maturity,and may have greater shale gas potential.The shale gas exploration breakthrough of the study area is of great significance to ensure the energy supply of economically developed areas on the east China.展开更多
Background Frailty is a major determinant of outcomes in patients with coronary artery disease(CAD)undergoing lower limb amputation.This study evaluates the impact of frailty on in-hospital outcomes in these patients....Background Frailty is a major determinant of outcomes in patients with coronary artery disease(CAD)undergoing lower limb amputation.This study evaluates the impact of frailty on in-hospital outcomes in these patients.Methods We performed a retrospective analysis of the National Inpatient Sample(2016–2021)to identify adult patients with CAD who underwent lower limb amputation.Frailty was defined using the Johns Hopkins Adjusted Clinical Groups(ACG)frailty indicator.Multivariable logistic regression was used to assess the independent association of frailty with in-hospital outcomes,and propensity score matching(PSM)was performed to further account for confounding factors.Results After PSM,9,990 patients were included in each cohort.Frail patients experienced higher rates of in-hospital mortality(3.9%vs.1.5%,P<0.001),acute limb ischemia(3.8%vs.3.1%,P=0.015),fasciotomy(2.1%vs.1.4%,P<0.001),stump infection(7.9%vs.6.6%,P<0.001),cardiogenic shock(0.9%vs.0.7%,P=0.032),sudden cardiac arrest(2.7%vs.2.1%,P=0.004),mechanical circulatory support(0.3%vs.0.2%,P=0.028),major adverse cardiac and cerebrovascular events(7.7%vs.5.4%,P<0.001),and sepsis(18.3%vs.13.8%,P<0.001).In multivariable logistic regression analysis,frailty remained an independent predictor of inhospital mortality and major complications.Conclusion Frailty is independently associated with increased in-hospital mortality and adverse events among CAD patients undergoing lower limb amputation.Incorporating frailty assessment into preoperative evaluation may improve risk stratification and guide clinical decision-making in this high-risk population.展开更多
AIM:To evaluate the outcome and the degree of patient satisfaction with the reconstruction of full-thickness medial and central lower lid defects using a pendular flap of the remaining lateral part of the lower lid.ME...AIM:To evaluate the outcome and the degree of patient satisfaction with the reconstruction of full-thickness medial and central lower lid defects using a pendular flap of the remaining lateral part of the lower lid.METHODS:Totally 20 patients with full thickness medial or central lower lid defects that could not be repaired by direct closure with or without cantholysis.A sliding full-thickness composite flap was created from the lateral part of the remaining lid to cover the defect.The posterior lamella of the induced lateral defect was repaired by either a periosteal flap alone or in combination with a free tarsal graft.Postoperative cosmetic and functional outcomes were evaluated.RESULTS:The mean age of the patients was 46.3±18.1y(20-70y).The defects ranged from 30%-80%of the lid width and resulted from the excision of lid tumors in 11 patients(55%)and from trauma in 9(45%)patients.Postoperative complications included one case of lateral graft ectropion,2 cases of lid retraction and 3 cases of marginal graft necrosis.Most of the patients had an acceptable final cosmetic outcome.CONCLUSION:Reconstruction of moderate-sized defects in the medial/central lower lid via a sliding flap yielded acceptable cosmetic and functional outcomes with high patient satisfaction.Large defects≥50%of the horizontal length are at greater risk of complications.Reconstruction of medial defects by this technique was associated with a greater incidence of complications.展开更多
BACKGROUND The prevalence of lower extremity arteriosclerosis obliterans(LEASO)in China is progressively increasing with the increment in age.Certain patients may be diagnosed with lower extremity arterial stenosis an...BACKGROUND The prevalence of lower extremity arteriosclerosis obliterans(LEASO)in China is progressively increasing with the increment in age.Certain patients may be diagnosed with lower extremity arterial stenosis and occlusion that resist complete curative efforts,which will invariably impose a substantial psychological strain on them.AIM To investigate the anxiety and depression conditions among patients with LEASO and analyze the associated risk factors.METHODS The Affiliated Hospital of Bengbu Medical University from January 2019 to December 2022.Their demographic and clinical data were obtained through the basic information questionnaire.The social support situation was assessed with the social support rating scale,and the hospital anxiety and depression scale were used to analyze their depression and anxiety levels.RESULTS The prevalence rate of anxiety was 44.0%among the 159 patients,with a total Self-Rating Anxiety Scale score of 49.01±9.65.The incidence of depression was 40.9%,and the total self-rating depression scale score reached 49.91±9.18.The overall social support score for all participants averaged 24.82±5.80.The correlation analysis between social support scores and anxiety and depression scores revealed that the total social support score,subjective social support,objective social support,as well as the degree of social support utilization,all exhibited a significant negative correlation with the anxiety and depression scores,which was statistically significant(P<0.05).The univariate analysis revealed statistically significant differences in the depression and anxiety states among patients with varying pain manifestations,disease stages,disease durations,and social support magnitudes(P<0.05).The multivariate analysis further demonstrated that patients presenting with intermittent claudication,rest pain,and pain,whose disease course was within half a year,and who had relatively low social support,were more predisposed to anxiety.Intriguingly,a monthly income of>6000 yuan was considered a protective factor in this context(P<0.05).Similarly,patients with intermittent claudication,rest pain,gangrene,and pain,and who had relatively low social support,were more liable to succumb to depressive moods(P<0.05).CONCLUSION Patients with LEASO typically receive relatively scant social support.Notably,those who concurrently present with symptoms,such as pain,claudication,and gangrene,are at a substantially increased risk of developing depression and anxiety disorders.A significant negative correlation is manifested between the social support level that patients receive and the severity of their anxiety and depression symptoms.Hence,the lower the social support score,the greater the propensity for patients to experience anxiety and depressive emotions.Therefore,during clinical practice,the crucial role that social support plays in safeguarding patients’physical and mental well-being as well as facilitating the effectiveness of disease treatment needs to be particularly emphasized.展开更多
Early Cambrian organic-rich shales in the Yangtze Plate are key shale gas exploration targets in China,but their sedimentary environments are not well understood.This lack of knowledge complicates the evaluation of th...Early Cambrian organic-rich shales in the Yangtze Plate are key shale gas exploration targets in China,but their sedimentary environments are not well understood.This lack of knowledge complicates the evaluation of these targets and associated risks.Assessing shale depositional environments is also challenging due to the fine-grained nature of the sediments and subtle compositional variations.Herein,marine black shales of the Lower Cambrian Shiyantou(SYT)Formation(Fm)and Yu'anshan(YAS)Fm are investigated through a series of experiment,including thin sections,scanning electron microscopy,and major and trace elements analysis.Results show that five lithofacies can be identified in the SYT and YAS shales:(1)calcareous mudstone;(2)wavy-laminated sand,silt,and clay bearing mudstone;(3)laminated and massive mudstone;(4)planar-laminated pyritic mudstone,and(5)thin bedded sand and siltstone.Average content of major elements SiO_(2),Al_(2)O_(3),MgO,Fe_(2)O_(3),K_(2)O,CaO,Na_(2)O,TiO_(2),P_(2)O_(5),and MnO of SYT Fm are 57.03%,12.74%,4.20%,3.97%,3.93%,3.35%,1.09%,0.68%,0.28%,and 0.05%,respectively.Average content of major elements SiO_(2),Al_(2)O_(3),MgO,Fe_(2)O_(3),K_(2)O,CaO,Na_(2)O,TiO_(2),P_(2)O_(5),and MnO of Yu'anshan Fm are 54.93%,14.52%,5.26%,6.00%,3.77%,3.88%,0.15%,0.63%,0.19%,and 0.10%,respectively.Samples from SYT Fm are enriched in Li,V,Cr,Co,Zr,Cs,and U relative to Upper Continental Crust(UCC)and most of shale samples from YAS Fm are enriched in Li,V,Co,and U relative to UCC.The marine black shales are deposited in dynamic anoxic to oxic environment in upper Yangtze Plate,which indicated the seabed had already oxidized in the Cambrian Stages 2 and 3.The Chemical Index of Alteration(CIA)values ranged 51.84–79.46 indicate a warm and humid climate in the 2 stages.These findings are consistent with the region's paleogeography and previous studies.They hold significance for sedimentologists,paleontologists,and other researchers involved in petroleum geology.展开更多
In Switzerland,the Opalinus Clay has been selected as a potential host rock for the deep geological disposal of radioactive waste due to its low hydraulic conductivity and favorable swelling properties.During the oper...In Switzerland,the Opalinus Clay has been selected as a potential host rock for the deep geological disposal of radioactive waste due to its low hydraulic conductivity and favorable swelling properties.During the operational phase of the repository,the host rock will be exposed to pH values as high as 13.5 due to concrete degradation,which will certainly affect its hydraulic properties.This study investigates the effect of pH increase on the water retention properties of Opalinus Clay.A series of samples from the lower sandy facies of the Mont Terri site in Switzerland,at initial dry state,were exposed to a hyperalkaline solution of pH=13.5 and to the synthetic water of pH=7.5 at different water contents.After equilibrium,the total suction was measured with a dew point potentiometer and microstructural analyses were conducted via mercury intrusion porosimetry(MIP)and nitrogen adsorption-desorption technique.It was found that the total suction decreased with hydration and pH increase.Since the two investigated solutions have the same osmotic suction,the decrease in total suction was attributed to the decrease in matric suction.Indeed,the total porosity increased with saturation and pH increase.This was confirmed by MIP data that evidenced an increase in the proportion of macropores,and by Barret eJoynereHalenda(BJH)data that showed mesopore generation.The specific surface area(SSA)also increased.The previous results were due to mineral hydration and,exclusively in the case of alkaline solution,to(1)the dissolution of quartz and calcite and(2)the acid-base reactions,which were concentrated at the edges of the clay particles,leading to an increase in negatively charged groups and thus to a face-to-face association of the clay particles(dispersion),causing an increase in the repulsive forces between the clay particles.In addition,the weakening of covalent bonds led to the primary dissolution of clay minerals,i.e.silicon and aluminum detachment.展开更多
Understanding mixed infections in the female lower genital tract is a critical challenge in modern infection research.The interplay of multiple pathogens complicates disease progression,often resulting in treatment fa...Understanding mixed infections in the female lower genital tract is a critical challenge in modern infection research.The interplay of multiple pathogens complicates disease progression,often resulting in treatment failure,recurrent infections,and significant public health and economic burdens.These infections are further exacerbated by disrupted host immune responses,which hinder the recovery of the vaginal microecosystem.Additionally,microbial biofilms—a fundamental mode of pathogen coexistence—contribute to the persistence and drug resistance of these infections,complicating management strategies.This review examines the pathogenesis,diagnosis,and treatment of mixed infections in the female lower genital tract while exploring potential avenues for future research.These findings emphasize the need for greater focus on these infections and offer insights to enhance further research in this area.展开更多
基金Supported by Zhejiang Provincial Natural Science Foundation of China(No.ZCLQN25A0103)。
文摘This paper studies certain estimates for the lower bound of distance between unitary orbits of normal elements.We show that the distance between unitary orbits of normal elements of simple C^(*)-algebras of tracial rank no more than k has a lower bound.Furthermore,if k≤1 and normal elements are commuting,then the lower bound will be better.Another result establishes a connection involving the spectrum distance operator Dc between a C^(*)-algebra of stable rank one C^(*)-algebra and its hereditary C^(*)-subalgebra.
基金supported in part by the National Natural Science Foundation of China under Grant 62172368the Natural Science Foundation of Zhejiang Province under Grant LR22F020003.
文摘The development of brain-computer interfaces(BCI)based on motor imagery(MI)has greatly improved patients’quality of life with movement disorders.The classification of upper limb MI has been widely studied and applied in many fields,including rehabilitation.However,the physiological representations of left and right lower limb movements are too close and activated deep in the cerebral cortex,making it difficult to distinguish their features.Therefore,classifying lower limbs motor imagery is more challenging.In this study,we propose a feature extraction method based on functional connectivity,which utilizes phase-locked values to construct a functional connectivity matrix as the features of the left and right legs,which can effectively avoid the problem of physiological representations of the left and right lower limbs being too close to each other during movement.In addition,considering the topology and the temporal characteristics of the electroencephalogram(EEG),we designed a temporal-spatial convolutional network(TSGCN)to capture the spatiotemporal information for classification.Experimental results show that the accuracy of the proposed method is higher than that of existing methods,achieving an average classification accuracy of 73.58%on the internal dataset.Finally,this study explains the network mechanism of left and right foot MI from the perspective of graph theoretic features and demonstrates the feasibility of decoding lower limb MI.
基金Supported by the Central Guided Local Science and Technology Development Fund Project for Science and Technology Innovation Base Construction,No.Guike ZY24212046National Natural Science Foundation of China,No.U22A2092+3 种基金Guangxi Education Science“the 14th Five-Year Plan”2024 Special Project“Research on Steam Education Practice in Rehabilitation Engineering”,No.2024ZJY304the Research Basic Ability Enhancement Program for Young and Middle-aged Teachers of Guangxi,No.2025KY2255the Innovation Project of GUET Graduate Education,No.2025YCXB010Natural Science Research Project of Guilin Life and Health Career Technical College,No.2025GKKY04.
文摘BACKGROUND The therapeutic role of neurodynamic mobilization in improving lower limb function in patients with mild post-traumatic knee osteoarthritis remains poorly understood.AIM To further elucidate the role of neurodynamic mobilization in facilitating knee joint functional recovery.METHODS Thirty-two patients with post-traumatic knee osteoarthritis treated at Chonghua Hospital of Traditional Chinese Medicine(Guilin)from March 2024 to August 2025 were randomly assigned to a control group(n=16)or an intervention group(n=16).Both groups received eight weeks of conventional treatment;and the intervention group additionally underwent neurodynamic mobilization.Outcomes including pain assessed by the visual analogue scale,active range of motion,Lysholm score,stork stand test,single hop test,and Y-balance test were assessed before and after the intervention.RESULTS There were no significant differences between the two groups in baseline characteristics,including gender,age,body mass index,or surgical side(P>0.05).Two-way repeated-measures analysis of variance demonstrated significant time×group interaction effects for the visual analogue scale score(F=13.364,P<0.05),Lysholm knee score(F=20.385,P<0.05),stork stand test(F=103.756,P<0.05),and Y-balance test score(F=8.089,P<0.05).CONCLUSION Neurodynamic mobilization effectively reduces pain,improves knee function,and enhances lower limb balance in patients with mild post-traumatic knee osteoarthritis.
文摘Background:Prostate cancer is a common malignancy,with many men on active surveillance for localized,low-risk disease also experiencing lower urinary tract symptoms(LUTS)from benign prostatic hyperplasia(BPH).Water Vapor Thermal Therapy(WVTT)is a minimally invasive BPH treatment,but its safety and efficacy in this setting are unclear.Case Description:We report three men with localized PCa on active surveillance who underwent WVTT for LUTS.Conclusions:WVTT appears safe and potentially effective in treating LUTS,especially in those with lower-risk disease and smaller prostate volumes.Further research is needed to confirm safety,efficacy,and optimal patient selection.
文摘This research presents a Human Lower Limb Activity Recognition(HLLAR)system that identifies specific activities and predicts the angles of the knees simultaneously,based on the EMG signals.The HLLAR systems streamlines the research on the lower limb activities.The HILLAR model includes Discrete Hermite Wavelets Transform-based Synchrosqueezing(DHWTS),Deep Two-Layer Multiscale Convolutional Neural Network(DTLMCNN),and Generalized Regression Neural Network(GRNN)as feature extraction,activity recognition,and knee angle prediction respectively.Electromyography signal-based automatic lower limb activity detection is crucial to rehabilitation and human movement analysis.Yet several of these methods face issues in feature extraction in complex data,overlapping signals,extraction of crucial parameters,and adaptation constraints.This research aims classify lower limb activities and predict knee joint angles from electromy-ography signals using HILLAR model.The model is validated on two datasets,comprising 26 subjects performing three classes of activities:walking,standing,and sitting.The proposed model obtained a classification accuracy of 99.95%,along with significant achievements in precision(99.93%),recall(99.91%),and F1-score(99.93%).The generalized regression neural network predicted angles of the knee joint with a root mean squared error of 1.25%.Robustness is demonstrated through consistent results in five-fold cross-validation and statistical significance testing(p-value=0.004,McNemar's test).Additionally,the proposed model showed superior performance over baseline methods by reducing error rates by 18%and decreasing processing time to 0.98 s.
文摘Usually, only the Cramer-Rao lower bound （CRLB） of single target is taken into consideration in the state estimate of passive tracking systems. As for the case of multitarget, there are few works done due to its complexity. The recursion formula of the posterior Cramer-Rao lower bound （PCRLB） in multitarget bearings-only tracking with the three kinds of data association is presented. Meanwhile, computer simulation is carried out for data association. The final result shows that the accuracy probability of data association has an important impact on the PCRLB.
基金supported by the National High Level Hospital Clinical Research Funding(No.BJ-2023-066).
文摘Objective This study aims to analyze the burden of lower respiratory infections in Chinese elderly people aged 70 and above.Methods This study utilized Global Burden of Disease(GBD)1990-2050 prediction data to analyze changes in mortality rates and disability-adjusted life year(DALY)rates for lower respiratory infections in the elderly population(aged 70 and above)in China from 1990 to 2050.It also discusses future trends in the burden of lower respiratory infections(LRI)in China under different scenarios.Results According to GBD predictions,the burden of lower respiratory infections in the elderly aged 70 years and above in China is lower than the global average.The burden has been decreasing from 1990 to 2020,but is projected to increase from 2020 to 2050.Scenario-based predictions suggest that,under scenarios involving improvements in nutrition and vaccination,the burden of lower respiratory infections in the elderly in China is expected to be the lowest in 2050.Conclusion This study indicates that the burden of lower respiratory infections in elderly people aged 70 years and above in China remains a significant public health issue and may worsen.The government should consider strengthening the preventive measures and management strategies for respiratory infections in the elderly population.
基金supported by the National Natural Science Foundation of China (Grant No. 42041007)。
文摘Understanding the relationships between human activities and hydrological processes is critical for sustainable water resources management, especially under the threat of increasing climate extremes. China's Lower Yellow River(LYR) region is one of the world's most water-scarce and human-impacted areas, yet comprehensive information on its water resources is lacking. This study adopted a water resources system(WRS) analytical framework to investigate the water crisis facing the region. The findings reveal that over the last decade, the system's resilience has been undermined by the combined impacts of climate aridification and intensified human interference. Specifically, a delicate balance between natural groundwater depletion and irrigation replenishment has been disrupted by a series of drought events since 2012. Increased groundwater extraction during droughts, coupled with an imbalanced allocation of surface water resources, has led to a persistent decline in water storage that has continued even after the droughts have ended. To mitigate future climate risks in the LYR,we recommend implementing more adaptive strategies, such as flexible water regulation policies and combined surface-groundwater management. Lessons from the LYR have important implications for other regions facing water resource challenges.
文摘BACKGROUND Most patients who were included in previous studies on achalasia had increased lower esophageal sphincter(LES)pressure.Peroral endoscopic myotomy(POEM)has been confirmed to be effective at relieving the clinical symptoms of achalasia associated with increased LES pressure.AIM To identify the safety and efficacy of POEM for patients with normal LES integrated relaxation pressure(LES-IRP).METHODS The clinical data of patients who underwent POEM successfully in The First Medical Center of Chinese PLA General Hospital were retrospectively analyzed.A total of 481 patients who underwent preoperative high-resolution manometry(HRM)at our hospital were ultimately included in this research.According to the HRM results,the patients were divided into two groups:71 patients were included in the normal LES-IRP group(LES-IRP<15 mmHg)and 410 patients were included in the increased LES-IRP group(LES-IRP≥15 mmHg).Clinical characteristics,procedure-related parameters,adverse events,and outcomes were compared between the two groups to evaluate the safety and efficacy of POEM for patients with normal LES-IRP.RESULTS Among the 481 patients included in our study,209 were males and 272 were females,with a mean age of 44.2 years.All patients underwent POEM without severe adverse events.The median pre-treatment Eckardt scores of the normal LES-IRP and increased LES-IRP groups were 7.0 and 7.0(P=0.132),respectively,decreasing to 1.0 and 1.0 post-treatment(P=0.572).The clinical success rate of the normal LES-IRP group was 87.3%(62/71),and that of the increased LES-IRP group was 91.2%(374/410)(P=0.298).Reflux symptoms were measured by the GerdQ questionnaire,and the percentages of patients with GerdQ scores≥9 in the normal LES-IRP and increased LES-IRP groups were 8.5%and 10.7%,respectively(P=0.711).After matching,the rates of clinical success and the rates of GerdQ score≥9 were not significantly different between the two groups.CONCLUSION Our results suggest that POEM is safe and effective for achalasia and patients with normal LES-IRP.In addition,in patients with normal LES-IRP,compared with those with increased LES-IRP,POEM was not associated with a greater incidence of reflux symptoms.
文摘Introduction: Foreign bodies (FB) in the lower airways (LAs) constitute a potentially life-threatening emergency requiring immediate management. The objective of our study was to describe the patient pathway and management of foreign bodies in the lower airways. Methodology: This was a descriptive study with retrospective data collection conducted over a 6-year period (January 1, 2014, to December 31, 2019) in the ENT and Head and Neck Surgery Department of Donka National Hospital. Results: We observed a prevalence of 1.79%. The average age was 5.71 years, with a sex ratio of 1.2. However, 82.61% of the cases originated from rural areas. We noted that 78.83% of patients were referred after visiting 1 to 2 healthcare facilities (75.36%). The consultation delay was 3 days. Penetration syndrome was present in 98.56% of cases. The foreign body incidents occurred during play in 54.84% and during meals in 29.09% of cases. Radiographs were performed in 93.9% of cases. Endoscopy was used for both diagnostic and therapeutic purposes in all patients. The foreign bodies were located in the trachea (37.68%), larynx (26.08%), and bronchi (21.73%). Non-organic foreign bodies were predominant (52.17%). Postoperative outcomes were uncomplicated in 95.98% of cases, and the lethality rate was 2.85%. Conclusion: The pathway of patients with foreign bodies in the airways remains unpredictable in our context due to parental hesitations. Early management reduces morbidity and mortality rates.
文摘Varicose veins of the lower limbs are a cosmopolitan condition, thought to be rare in Africa but widespread in Europe. The aim of this study is to analyze the indications and evaluate the results of surgical management of varicose pathology of the IM in Dakar. We enrolled 280 patients, with a mean age of 36 and a sex ratio of 2. Factors favouring venous disease were dominated by prolonged orthostatism and multiparity. The average consultation time was 6 years. The reasons for consultation were functional manifestations, progressive complications and aesthetics. The venous trunks concerned were the great saphenous vein (GSV) in 58.9% of cases, the small saphenous vein (SSV) in 29% of cases, perforating veins and varicose veins were unsystematized in 28.5% of cases. Surgery was performed under spinal anaesthesia. Surgical procedures were dominated by stripping of the GSV, crossectomy of the SSV and staged ligations. One patient developed meningismus immediately after the operation. Average follow-up was 2 years. Mortality was null.
文摘Purpose: To evaluate open lower limb trauma management in children. Me-thod: We conducted a twelve-month cross-sectional prospective study. Results: Open trauma of lower limb had 7.9% of hospital frequency. Mean age was 8 years with a sex ratio of 2.45. In 68.4% of cases, trauma occurred in road traffic accidents. Average consultation time was 2.4 hours. Trauma mainly affected the leg in 39.5% of cases, and the thigh in 34.2%. Soft tissue wounds occurred in 52.6% of cases, and open fractures in 47.4%. Average response time was one hour. Wound trimming and suturing were performed in 76.3% of cases and combined with bone nailing in 15.8%. The outcome was favorable in 92.1% of cases. Average hospital stay was 4.37 days. Conclusion: Open trauma to the lower limb is a frequent and occurs mainly in road traffic accidents. Management was early, with a favorable outcome for most patients and a short hospital stay.
文摘Here we report a left cheek plate of Psarolepis,a postparietal shield of Youngolepis,a skull of Diabolepis,and a scale of Styloichthys from the Lianhuashan and Nahkaoling formations(Lochkovian,Lower Devonian)of Nanning,Guangxi.This marks the first report of Diabolepis and Styloichthys beside Qujing,Yunnan,and the latest occurrence of Psarolepis to date.The fossil community displays significant similarities to the Xujiachong Assemblage,and provides new data for the Lower Devonian stratigraphic correlation between southwestern China and northern Vietnam.Given the latest dating constraint based on the conodont evidence,we regard that the Xujiachong Assemblage has a much longer range than previously supposed,extending from the latest Lochkovian to the end of Pragian.We propose that the transition of the Nahkaoling and Lianhuashan formations in Nanning might correspond to the Guijiatun Formation in Qujing.The relatively large size of fish individuals from Guangxi is probably attributed to the increase in the oxygen content of the ocean.
基金supported by the Natural Science Foundation of Shandong Province(ZR2023MD112)financially supported by Laoshan Laboratory(LSKJ202203401).
文摘Shale gas is abundant in the Paleozoic of the Yangtze Platform,and several high-yield shale gas fields have been built in the Upper Yangtze Platform,China.The Permian of the South Yellow Sea Basin(SYSB)in the Lower Yangtze area is considered a potential target for shale gas exploration;however,the fundamental geological conditions of shale gas have not been studied.Based on the first whole-cored scientific drilling borehole(CSDP-2)in the SYSB,detailed tests involving petrology,organic geochemistry,and reservoir physical properties were conducted to evaluate the shale gas potential of the Lower Permian.The Lower Permian is dominated by organic-rich siliceous,clay,and clay-mixed shales.The average total organic carbon content is 5.99%,and the organic matter is mainly type Ⅱ_(1)−Ⅱ_(2),which has entered the high-over mature evolution stage.The pore types of organic-rich shales mainly include organic pores,dissolution pores,and intergranular pores,of which the meso-/macropores are well developed.The average porosity is 3.04%,and the total specific surface area and pore volume are 3.47 m^(2)/g and 7.21×10^(−3) cm^(3)/g,respectively.The average Langmuir volume obtained from the methane adsorption isotherms is 2.70 cm^(3)/g,and methane is mainly adsorbed in the meso-/macropores.The lower Permian shales are rich in methane as indicated by gas logging results,with an average content of 7.3%,which can reach up to 65.9%.A comparison of the study area with typical shale gas fields shows that the Lower Permian is brittle and shallowly buried and has a high potential for shale gas exploration and low-cost development.The depression areas of the SYSB are overlain by thick Mesozoic-Cenozoic sediments,show higher organic matter maturity,and may have greater shale gas potential.The shale gas exploration breakthrough of the study area is of great significance to ensure the energy supply of economically developed areas on the east China.
文摘Background Frailty is a major determinant of outcomes in patients with coronary artery disease(CAD)undergoing lower limb amputation.This study evaluates the impact of frailty on in-hospital outcomes in these patients.Methods We performed a retrospective analysis of the National Inpatient Sample(2016–2021)to identify adult patients with CAD who underwent lower limb amputation.Frailty was defined using the Johns Hopkins Adjusted Clinical Groups(ACG)frailty indicator.Multivariable logistic regression was used to assess the independent association of frailty with in-hospital outcomes,and propensity score matching(PSM)was performed to further account for confounding factors.Results After PSM,9,990 patients were included in each cohort.Frail patients experienced higher rates of in-hospital mortality(3.9%vs.1.5%,P<0.001),acute limb ischemia(3.8%vs.3.1%,P=0.015),fasciotomy(2.1%vs.1.4%,P<0.001),stump infection(7.9%vs.6.6%,P<0.001),cardiogenic shock(0.9%vs.0.7%,P=0.032),sudden cardiac arrest(2.7%vs.2.1%,P=0.004),mechanical circulatory support(0.3%vs.0.2%,P=0.028),major adverse cardiac and cerebrovascular events(7.7%vs.5.4%,P<0.001),and sepsis(18.3%vs.13.8%,P<0.001).In multivariable logistic regression analysis,frailty remained an independent predictor of inhospital mortality and major complications.Conclusion Frailty is independently associated with increased in-hospital mortality and adverse events among CAD patients undergoing lower limb amputation.Incorporating frailty assessment into preoperative evaluation may improve risk stratification and guide clinical decision-making in this high-risk population.
文摘AIM:To evaluate the outcome and the degree of patient satisfaction with the reconstruction of full-thickness medial and central lower lid defects using a pendular flap of the remaining lateral part of the lower lid.METHODS:Totally 20 patients with full thickness medial or central lower lid defects that could not be repaired by direct closure with or without cantholysis.A sliding full-thickness composite flap was created from the lateral part of the remaining lid to cover the defect.The posterior lamella of the induced lateral defect was repaired by either a periosteal flap alone or in combination with a free tarsal graft.Postoperative cosmetic and functional outcomes were evaluated.RESULTS:The mean age of the patients was 46.3±18.1y(20-70y).The defects ranged from 30%-80%of the lid width and resulted from the excision of lid tumors in 11 patients(55%)and from trauma in 9(45%)patients.Postoperative complications included one case of lateral graft ectropion,2 cases of lid retraction and 3 cases of marginal graft necrosis.Most of the patients had an acceptable final cosmetic outcome.CONCLUSION:Reconstruction of moderate-sized defects in the medial/central lower lid via a sliding flap yielded acceptable cosmetic and functional outcomes with high patient satisfaction.Large defects≥50%of the horizontal length are at greater risk of complications.Reconstruction of medial defects by this technique was associated with a greater incidence of complications.
基金Supported by the Key Project of Natural Science Research in Universities of Anhui Province,No.2023AH051985Key Project of Natural Science Research at Bengbu Medical University,No.2023byzd038Anhui Provincial Health Research Project,No.AHWJ2024BAc30042.
文摘BACKGROUND The prevalence of lower extremity arteriosclerosis obliterans(LEASO)in China is progressively increasing with the increment in age.Certain patients may be diagnosed with lower extremity arterial stenosis and occlusion that resist complete curative efforts,which will invariably impose a substantial psychological strain on them.AIM To investigate the anxiety and depression conditions among patients with LEASO and analyze the associated risk factors.METHODS The Affiliated Hospital of Bengbu Medical University from January 2019 to December 2022.Their demographic and clinical data were obtained through the basic information questionnaire.The social support situation was assessed with the social support rating scale,and the hospital anxiety and depression scale were used to analyze their depression and anxiety levels.RESULTS The prevalence rate of anxiety was 44.0%among the 159 patients,with a total Self-Rating Anxiety Scale score of 49.01±9.65.The incidence of depression was 40.9%,and the total self-rating depression scale score reached 49.91±9.18.The overall social support score for all participants averaged 24.82±5.80.The correlation analysis between social support scores and anxiety and depression scores revealed that the total social support score,subjective social support,objective social support,as well as the degree of social support utilization,all exhibited a significant negative correlation with the anxiety and depression scores,which was statistically significant(P<0.05).The univariate analysis revealed statistically significant differences in the depression and anxiety states among patients with varying pain manifestations,disease stages,disease durations,and social support magnitudes(P<0.05).The multivariate analysis further demonstrated that patients presenting with intermittent claudication,rest pain,and pain,whose disease course was within half a year,and who had relatively low social support,were more predisposed to anxiety.Intriguingly,a monthly income of>6000 yuan was considered a protective factor in this context(P<0.05).Similarly,patients with intermittent claudication,rest pain,gangrene,and pain,and who had relatively low social support,were more liable to succumb to depressive moods(P<0.05).CONCLUSION Patients with LEASO typically receive relatively scant social support.Notably,those who concurrently present with symptoms,such as pain,claudication,and gangrene,are at a substantially increased risk of developing depression and anxiety disorders.A significant negative correlation is manifested between the social support level that patients receive and the severity of their anxiety and depression symptoms.Hence,the lower the social support score,the greater the propensity for patients to experience anxiety and depressive emotions.Therefore,during clinical practice,the crucial role that social support plays in safeguarding patients’physical and mental well-being as well as facilitating the effectiveness of disease treatment needs to be particularly emphasized.
基金Supported by the National Natural Science Foundation of China(Nos.42130206,41302076)the Ministry of Science and Technology of the People’s Republic of China(MOST)Special Fund+1 种基金the State Key Laboratory of Continental Dynamics,Northwest University(No.201210128)the Major Scientific and Technological Projects of Changqing Oilfield(No.ZDZX-2021-03)。
文摘Early Cambrian organic-rich shales in the Yangtze Plate are key shale gas exploration targets in China,but their sedimentary environments are not well understood.This lack of knowledge complicates the evaluation of these targets and associated risks.Assessing shale depositional environments is also challenging due to the fine-grained nature of the sediments and subtle compositional variations.Herein,marine black shales of the Lower Cambrian Shiyantou(SYT)Formation(Fm)and Yu'anshan(YAS)Fm are investigated through a series of experiment,including thin sections,scanning electron microscopy,and major and trace elements analysis.Results show that five lithofacies can be identified in the SYT and YAS shales:(1)calcareous mudstone;(2)wavy-laminated sand,silt,and clay bearing mudstone;(3)laminated and massive mudstone;(4)planar-laminated pyritic mudstone,and(5)thin bedded sand and siltstone.Average content of major elements SiO_(2),Al_(2)O_(3),MgO,Fe_(2)O_(3),K_(2)O,CaO,Na_(2)O,TiO_(2),P_(2)O_(5),and MnO of SYT Fm are 57.03%,12.74%,4.20%,3.97%,3.93%,3.35%,1.09%,0.68%,0.28%,and 0.05%,respectively.Average content of major elements SiO_(2),Al_(2)O_(3),MgO,Fe_(2)O_(3),K_(2)O,CaO,Na_(2)O,TiO_(2),P_(2)O_(5),and MnO of Yu'anshan Fm are 54.93%,14.52%,5.26%,6.00%,3.77%,3.88%,0.15%,0.63%,0.19%,and 0.10%,respectively.Samples from SYT Fm are enriched in Li,V,Cr,Co,Zr,Cs,and U relative to Upper Continental Crust(UCC)and most of shale samples from YAS Fm are enriched in Li,V,Co,and U relative to UCC.The marine black shales are deposited in dynamic anoxic to oxic environment in upper Yangtze Plate,which indicated the seabed had already oxidized in the Cambrian Stages 2 and 3.The Chemical Index of Alteration(CIA)values ranged 51.84–79.46 indicate a warm and humid climate in the 2 stages.These findings are consistent with the region's paleogeography and previous studies.They hold significance for sedimentologists,paleontologists,and other researchers involved in petroleum geology.
文摘In Switzerland,the Opalinus Clay has been selected as a potential host rock for the deep geological disposal of radioactive waste due to its low hydraulic conductivity and favorable swelling properties.During the operational phase of the repository,the host rock will be exposed to pH values as high as 13.5 due to concrete degradation,which will certainly affect its hydraulic properties.This study investigates the effect of pH increase on the water retention properties of Opalinus Clay.A series of samples from the lower sandy facies of the Mont Terri site in Switzerland,at initial dry state,were exposed to a hyperalkaline solution of pH=13.5 and to the synthetic water of pH=7.5 at different water contents.After equilibrium,the total suction was measured with a dew point potentiometer and microstructural analyses were conducted via mercury intrusion porosimetry(MIP)and nitrogen adsorption-desorption technique.It was found that the total suction decreased with hydration and pH increase.Since the two investigated solutions have the same osmotic suction,the decrease in total suction was attributed to the decrease in matric suction.Indeed,the total porosity increased with saturation and pH increase.This was confirmed by MIP data that evidenced an increase in the proportion of macropores,and by Barret eJoynereHalenda(BJH)data that showed mesopore generation.The specific surface area(SSA)also increased.The previous results were due to mineral hydration and,exclusively in the case of alkaline solution,to(1)the dissolution of quartz and calcite and(2)the acid-base reactions,which were concentrated at the edges of the clay particles,leading to an increase in negatively charged groups and thus to a face-to-face association of the clay particles(dispersion),causing an increase in the repulsive forces between the clay particles.In addition,the weakening of covalent bonds led to the primary dissolution of clay minerals,i.e.silicon and aluminum detachment.
基金supported by a grant from the National Natural Science Foundation of China(No.81874483).
文摘Understanding mixed infections in the female lower genital tract is a critical challenge in modern infection research.The interplay of multiple pathogens complicates disease progression,often resulting in treatment failure,recurrent infections,and significant public health and economic burdens.These infections are further exacerbated by disrupted host immune responses,which hinder the recovery of the vaginal microecosystem.Additionally,microbial biofilms—a fundamental mode of pathogen coexistence—contribute to the persistence and drug resistance of these infections,complicating management strategies.This review examines the pathogenesis,diagnosis,and treatment of mixed infections in the female lower genital tract while exploring potential avenues for future research.These findings emphasize the need for greater focus on these infections and offer insights to enhance further research in this area.
