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Significant risk factors for intensive care unit-acquired weakness:A processing strategy based on repeated machine learning 被引量:10
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作者 Ling Wang Deng-Yan Long 《World Journal of Clinical Cases》 SCIE 2024年第7期1235-1242,共8页
BACKGROUND Intensive care unit-acquired weakness(ICU-AW)is a common complication that significantly impacts the patient's recovery process,even leading to adverse outcomes.Currently,there is a lack of effective pr... BACKGROUND Intensive care unit-acquired weakness(ICU-AW)is a common complication that significantly impacts the patient's recovery process,even leading to adverse outcomes.Currently,there is a lack of effective preventive measures.AIM To identify significant risk factors for ICU-AW through iterative machine learning techniques and offer recommendations for its prevention and treatment.METHODS Patients were categorized into ICU-AW and non-ICU-AW groups on the 14th day post-ICU admission.Relevant data from the initial 14 d of ICU stay,such as age,comorbidities,sedative dosage,vasopressor dosage,duration of mechanical ventilation,length of ICU stay,and rehabilitation therapy,were gathered.The relationships between these variables and ICU-AW were examined.Utilizing iterative machine learning techniques,a multilayer perceptron neural network model was developed,and its predictive performance for ICU-AW was assessed using the receiver operating characteristic curve.RESULTS Within the ICU-AW group,age,duration of mechanical ventilation,lorazepam dosage,adrenaline dosage,and length of ICU stay were significantly higher than in the non-ICU-AW group.Additionally,sepsis,multiple organ dysfunction syndrome,hypoalbuminemia,acute heart failure,respiratory failure,acute kidney injury,anemia,stress-related gastrointestinal bleeding,shock,hypertension,coronary artery disease,malignant tumors,and rehabilitation therapy ratios were significantly higher in the ICU-AW group,demonstrating statistical significance.The most influential factors contributing to ICU-AW were identified as the length of ICU stay(100.0%)and the duration of mechanical ventilation(54.9%).The neural network model predicted ICU-AW with an area under the curve of 0.941,sensitivity of 92.2%,and specificity of 82.7%.CONCLUSION The main factors influencing ICU-AW are the length of ICU stay and the duration of mechanical ventilation.A primary preventive strategy,when feasible,involves minimizing both ICU stay and mechanical ventilation duration. 展开更多
关键词 Intensive care unit-acquired weakness Risk factors Machine learning PREVENTION Strategies
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Beidou receiver based on anti-jamming antenna arrays with self-calibration for precise relative positioning
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作者 AN Yi KANG Ronglei +1 位作者 BAN Yalong YANG Shaoshuai 《Journal of Systems Engineering and Electronics》 SCIE CSCD 2024年第5期1132-1147,共16页
Unmanned aerial vehicles(UAVs)may be subjected to unintentional radio frequency interference(RFI)or hostile jamming attack which will lead to fail to track global navigation satellite system(GNSS)signals.Therefore,the... Unmanned aerial vehicles(UAVs)may be subjected to unintentional radio frequency interference(RFI)or hostile jamming attack which will lead to fail to track global navigation satellite system(GNSS)signals.Therefore,the simultaneous realization of anti-jamming and high-precision carrier phase difference positioning becomes a dilemmatic problem.In this paper,a distortionless phase digital beamforming(DBF)algorithm with self-calibration antenna arrays is proposed,which enables to obtain distortionless carrier phase while suppressing jamming.Additionally,architecture of high precision Beidou receiver based on anti-jamming antenna arrays is proposed.Finally,the performance of the algorithm is evaluated,including antenna calibration accuracy,carrier phase distortionless accuracy,and carrier phase measurement accuracy without jamming.Meanwhile,the maximal jamming to signal ratio(JSR)and real time kinematic(RTK)positioning accuracy under wideband jamming are also investigated.The experimental results based on the real-life Beidou signals show that the proposed method has an excellent performance for precise relative positioning under jamming when compared with other anti-jamming methods. 展开更多
关键词 Beidou receiver antenna array anti-jamming high precision distortionless carrier phase
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Anti-Jamming Null Space Projection Beamforming Based on Symbiotic Radio
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作者 Baofeng Ji Yifan Liu +6 位作者 Tingpeng Li Ling Xing Weixing Wang Shahid Mumtaz Xiaolong Shang Wanying Liu Congzheng Han 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第1期679-689,共11页
With the development of information technology,more and more devices are connected to the Internet through wireless communication to complete data interconnection.Due to the broadcast characteristics ofwireless channe... With the development of information technology,more and more devices are connected to the Internet through wireless communication to complete data interconnection.Due to the broadcast characteristics ofwireless channels,wireless networks have suffered more and more malicious attacks.Physical layer security has received extensive attention from industry and academia.MIMO is considered to be one of the most important technologies related to physical layer security.Through beamforming technology,messages can be transmitted to legitimate users in an offset direction that is as orthogonal as possible to the interference channel to ensure the reception SINR by legitimate users.Combining the symbiotic radio(SR)technology,this paper considers a symbiotic radio antijamming MIMO system equipped with a multi-antenna system at the main base station.In order to avoid the interference signal and improve the SINR of the signal received by the user.The base station is equipped with a uniform rectangular antenna array,and using Null Space Projection(NSP)Beamforming,Intelligent Reflecting Surface(IRS)can assist in changing the beam’s angle.The simulation results show that NSP Beamforming could make a better use of the null space of interference,which can effectively improve the received SINR of users under directional interference,and improve the utilization efficiency of signal energy. 展开更多
关键词 Symbiotic radio anti-jamming MIMO NSP Beamforming physical layer security
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Risk factors for intensive-care-unit-acquired weakness
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作者 Ming Liu Yu-Tong Chen +1 位作者 Guang-Liang Wang Xue-Mei Wu 《World Journal of Clinical Cases》 SCIE 2024年第21期4853-4855,共3页
Wang et al reported 1063 cases from the initial 14 d of intensive care unit(ICU)stay,and analyzed relevant data such as age,comorbidities,recent dosages,vapor pressure dosages,duration of mechanical ventilation,length... Wang et al reported 1063 cases from the initial 14 d of intensive care unit(ICU)stay,and analyzed relevant data such as age,comorbidities,recent dosages,vapor pressure dosages,duration of mechanical ventilation,length of ICU stay,and rehabilitation therapy,which are closely related to ICU-acquired weakness(ICUAW).It is suggested that the length of ICU stay and the duration of mechanical ventilation are the main factors.ICU-AW is the most common neuromuscular injury in the ICU,which affects clinical progression and outcomes of patients.This manuscript helps to improve the early recognition of ICU-AW,thereby reducing mortality and improving prognosis. 展开更多
关键词 Risk factors Intensive care unit Acquired weakness Prognosis Neuromuscular injury
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Intensive care unit-acquired weakness:Unveiling significant risk factors and preemptive strategies through machine learning
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作者 Xiao-Yu He Yi-Huan Zhao +1 位作者 Qian-Wen Wan Fu-Shan Tang 《World Journal of Clinical Cases》 SCIE 2024年第35期6760-6763,共4页
This editorial discusses an article recently published in the World Journal of Clinical Cases,focusing on risk factors associated with intensive care unit-acquired weak-ness(ICU-AW).ICU-AW is a serious neuromuscular c... This editorial discusses an article recently published in the World Journal of Clinical Cases,focusing on risk factors associated with intensive care unit-acquired weak-ness(ICU-AW).ICU-AW is a serious neuromuscular complication seen in criti-cally ill patients,characterized by muscle dysfunction,weakness,and sensory impairments.Post-discharge,patients may encounter various obstacles impacting their quality of life.The pathogenesis involves intricate changes in muscle and nerve function,potentially leading to significant disabilities.Given its global significance,ICU-AW has become a key research area.The study identified critical risk factors using a multilayer perceptron neural network model,highlighting the impact of intensive care unit stay duration and mechanical ventilation duration on ICU-AW.Recommendations were provided for preventing ICU-AW,empha-sizing comprehensive interventions and risk factor mitigation.This editorial stresses the importance of external validation,cross-validation,and model tran-sparency to enhance model reliability.Moreover,the application of machine learning in clinical medicine has demonstrated clear benefits in improving disease understanding and treatment decisions.While machine learning presents oppor-tunities,challenges such as model reliability and data management necessitate thorough validation and ethical considerations.In conclusion,integrating ma-chine learning into healthcare offers significant potential and challenges.Enhan-cing data management,validating models,and upholding ethical standards are crucial for maximizing the benefits of machine learning in clinical practice. 展开更多
关键词 Intensive care unit-acquired weakness Risk factors Machine learning Clinical medicine Treatment decision
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Evaluating neuromuscular electrical stimulation for preventing and managing intensive care unit-acquired weakness:Current evidence and future directions
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作者 Annu Lisa Kurian Brandon Lucke-Wold 《World Journal of Cardiology》 2024年第10期604-607,共4页
Intensive care unit-acquired weakness(ICU-AW)is a prevalent issue in critical care,leading to significant muscle atrophy and functional impairment.Aiming to address this,Neuromuscular Electrical Stimulation(NMES)has b... Intensive care unit-acquired weakness(ICU-AW)is a prevalent issue in critical care,leading to significant muscle atrophy and functional impairment.Aiming to address this,Neuromuscular Electrical Stimulation(NMES)has been explored as a therapy.This systematic review assesses NMES's safety and effectiveness in enhancing functional capacity and mobility in pre-and post-cardiac surgery patients.NMES was generally safe and feasible,with intervention sessions varying in frequency and duration.Improvements in muscle strength and 6-minute walking test distances were observed,particularly in preoperative settings,but postoperative benefits were inconsistent.NMES showed promise in preventing muscle loss and improving strength,although its impact on overall functional capacity remained uncertain.Challenges such as short ICU stays and body composition affecting NMES efficacy were noted.NMES also holds potential for other conditions like cerebral palsy and stroke.Further research is needed to optimize NMES protocols and better understand its full benefits in preventing ICU-AW and improving patient outcomes. 展开更多
关键词 Neuromuscular electrical stimulation Intensive care unit-acquired weakness Cardiac surgery Muscle atrophy Functional capacity
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Pioneering role of machine learning in unveiling intensive care unitacquired weakness
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作者 Silvano Dragonieri 《World Journal of Clinical Cases》 SCIE 2024年第13期2157-2159,共3页
In the research published in the World Journal of Clinical Cases,Wang and Long conducted a quantitative analysis to delineate the risk factors for intensive care unit-acquired weakness(ICU-AW)utilizing advanced machin... In the research published in the World Journal of Clinical Cases,Wang and Long conducted a quantitative analysis to delineate the risk factors for intensive care unit-acquired weakness(ICU-AW)utilizing advanced machine learning methodologies.The study employed a multilayer perceptron neural network to accurately predict the incidence of ICU-AW,focusing on critical variables such as ICU stay duration and mechanical ventilation.This research marks a significant advancement in applying machine learning to clinical diagnostics,offering a new paradigm for predictive medicine in critical care.It underscores the importance of integrating artificial intelligence technologies in clinical practice to enhance patient management strategies and calls for interdisciplinary collaboration to drive innovation in healthcare. 展开更多
关键词 Intensive care unit-acquired weakness Machine learning Multilayer perceptron neural network Predictive medicine Interdisciplinary collaboration
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Predicting intensive care unit-acquired weakness:A multilayer perceptron neural network approach
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作者 Carlos Martin Ardila Daniel González-Arroyave Mateo Zuluaga-Gómez 《World Journal of Clinical Cases》 SCIE 2024年第12期2023-2030,共8页
In this editorial,we comment on the article by Wang and Long,published in a recent issue of the World Journal of Clinical Cases.The article addresses the challenge of predicting intensive care unit-acquired weakness(I... In this editorial,we comment on the article by Wang and Long,published in a recent issue of the World Journal of Clinical Cases.The article addresses the challenge of predicting intensive care unit-acquired weakness(ICUAW),a neuromuscular disorder affecting critically ill patients,by employing a novel processing strategy based on repeated machine learning.The editorial presents a dataset comprising clinical,demographic,and laboratory variables from intensive care unit(ICU)patients and employs a multilayer perceptron neural network model to predict ICUAW.The authors also performed a feature importance analysis to identify the most relevant risk factors for ICUAW.This editorial contributes to the growing body of literature on predictive modeling in critical care,offering insights into the potential of machine learning approaches to improve patient outcomes and guide clinical decision-making in the ICU setting. 展开更多
关键词 Intensive care units Intensive care unit-acquired weakness Risk factors Machine learning Computer neural network
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Unveiling significant risk factors for intensive care unit-acquired weakness:Advancing preventive care
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作者 Chun-Yao Cheng Wen-Rui Hao Tzu-Hurng Cheng 《World Journal of Clinical Cases》 SCIE 2024年第18期3288-3290,共3页
In this editorial,we discuss an article titled,“Significant risk factors for intensive care unit-acquired weakness:A processing strategy based on repeated machine learning,”published in a recent issue of the World J... In this editorial,we discuss an article titled,“Significant risk factors for intensive care unit-acquired weakness:A processing strategy based on repeated machine learning,”published in a recent issue of the World Journal of Clinical Cases.Intensive care unit-acquired weakness(ICU-AW)is a debilitating condition that affects critically ill patients,with significant implications for patient outcomes and their quality of life.This study explored the use of artificial intelligence and machine learning techniques to predict ICU-AW occurrence and identify key risk factors.Data from a cohort of 1063 adult intensive care unit(ICU)patients were analyzed,with a particular emphasis on variables such as duration of ICU stay,duration of mechanical ventilation,doses of sedatives and vasopressors,and underlying comorbidities.A multilayer perceptron neural network model was developed,which exhibited a remarkable impressive prediction accuracy of 86.2%on the training set and 85.5%on the test set.The study highlights the importance of early prediction and intervention in mitigating ICU-AW risk and improving patient outcomes. 展开更多
关键词 Intensive care unit-acquired weakness Artificial intelligence Machine learning Neural network Risk factors Prediction Critical care
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Machine learning insights on intensive care unit-acquired weakness
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作者 Muad Abdi Hassan Abdulqadir J Nashwan 《World Journal of Clinical Cases》 SCIE 2024年第18期3285-3287,共3页
Intensive care unit-acquired weakness(ICU-AW)significantly hampers patient recovery and increases morbidity.With the absence of established preventive strategies,this study utilizes advanced machine learning methodolo... Intensive care unit-acquired weakness(ICU-AW)significantly hampers patient recovery and increases morbidity.With the absence of established preventive strategies,this study utilizes advanced machine learning methodologies to unearth key predictors of ICU-AW.Employing a sophisticated multilayer perceptron neural network,the research methodically assesses the predictive power for ICU-AW,pinpointing the length of ICU stay and duration of mechanical ventilation as pivotal risk factors.The findings advocate for minimizing these elements as a preventive approach,offering a novel perspective on combating ICU-AW.This research illuminates critical risk factors and lays the groundwork for future explorations into effective prevention and intervention strategies. 展开更多
关键词 Length of intensive care unit stay Intensive care unit-acquired weakness Machine learning Likelihood factors Precautionary measures
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Advancing critical care recovery:The pivotal role of machine learning in early detection of intensive care unit-acquired weakness
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作者 Georges Khattar Elie Bou Sanayeh 《World Journal of Clinical Cases》 SCIE 2024年第21期4455-4459,共5页
This editorial explores the significant challenge of intensive care unit-acquiredweakness(ICU-AW),a prevalent condition affecting critically ill patients,characterizedby profound muscle weakness and complicating patie... This editorial explores the significant challenge of intensive care unit-acquiredweakness(ICU-AW),a prevalent condition affecting critically ill patients,characterizedby profound muscle weakness and complicating patient recovery.Highlightingthe paradox of modern medical advances,it emphasizes the urgent needfor early identification and intervention to mitigate ICU-AW's impact.Innovatively,the study by Wang et al is showcased for employing a multilayer perceptronneural network model,achieving high accuracy in predicting ICU-AWrisk.This advancement underscores the potential of neural network models inenhancing patient care but also calls for continued research to address limitationsand improve model applicability.The editorial advocates for the developmentand validation of sophisticated predictive tools,aiming for personalized carestrategies to reduce ICU-AW incidence and severity,ultimately improving patientoutcomes in critical care settings. 展开更多
关键词 Critical illness myopathy Critical illness polyneuropathy Early detection Intensive care unit-acquired weakness Neural network models Patient outcomes Personalized intervention strategies Predictive modeling
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Intensive care unit-acquired weakness–preventive,and therapeutic aspects;future directions and special focus on lung transplantation
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作者 Thirugnanasambandan Sunder 《World Journal of Clinical Cases》 SCIE 2024年第19期3665-3670,共6页
In this editorial,comments are made on an interesting article in the recent issue of the World Journal of Clinical Cases by Wang and Long.The authors describe the use of neural network model to identify risk factors f... In this editorial,comments are made on an interesting article in the recent issue of the World Journal of Clinical Cases by Wang and Long.The authors describe the use of neural network model to identify risk factors for the development of intensive care unit(ICU)-acquired weakness.This condition has now become common with an increasing number of patients treated in ICUs and continues to be a source of morbidity and mortality.Despite identification of certain risk factors and corrective measures thereof,lacunae still exist in our understanding of this clinical entity.Numerous possible pathogenetic mechanisms at a molecular level have been described and these continue to be increasing.The amount of retrievable data for analysis from the ICU patients for study can be huge and enormous.Machine learning techniques to identify patterns in vast amounts of data are well known and may well provide pointers to bridge the knowledge gap in this condition.This editorial discusses the current knowledge of the condition including pathogenesis,diagnosis,risk factors,preventive measures,and therapy.Furthermore,it looks specifically at ICU acquired weakness in recipients of lung transplantation,because–unlike other solid organ transplants-muscular strength plays a vital role in the preservation and survival of the transplanted lung.Lungs differ from other solid organ transplants in that the proper function of the allograft is dependent on muscle function.Muscular weakness especially diaphragmatic weakness may lead to prolonged ventilation which has deleterious effects on the transplanted lung–ranging from ventilator associated pneumonia to bronchial anastomotic complications due to prolonged positive pressure on the anastomosis. 展开更多
关键词 Intensive care unit-acquired weakness Critical illness myopathy Critical illness polyneuropathy Critical illness polyneuromyopathy Early mobilization Prolonged ventilation Nutritional rehabilitation Lung transplantation
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Clinical Effect of Modified Shengyang Yiwei Decoction in the Treatment of Diarrhea-Predominant Irritable Bowel Syndrome due to Spleen and Stomach Weakness
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作者 Yamei Wang 《Journal of Clinical and Nursing Research》 2024年第1期174-180,共7页
Objective:To explore the therapeutic effect of Shengyang Yiwei Decoction in patients with diarrhea-predominant irritable bowel syndrome(IBS)due to spleen and stomach weakness.Methods:40 patients with diarrhea-predomin... Objective:To explore the therapeutic effect of Shengyang Yiwei Decoction in patients with diarrhea-predominant irritable bowel syndrome(IBS)due to spleen and stomach weakness.Methods:40 patients with diarrhea-predominant IBS who were treated from April 2018 to April 2020 were taken as samples.TCM(traditional Chinese medicine)syndrome differentiation found that they were all due to spleen and stomach weakness.They were randomly divided into two groups.Group A was treated with modified prescriptions of Shengyang Yiwei Decoction,while Group B was treated with Western medicine.The therapeutic effects in the two groups were compared.Results:The treatment efficacy in Group A was higher than that in Group B(P<0.05);the symptom scores of Group A such as loose stools,chills,physical weakness,poor appetite,and abdominal distension after meals were all lower than those in Group B(P<0.05);the SF-36(36-Item Short Form Health Survey)scores of patients with diarrhea-predominant IBS in Group A were higher than those in Group B(P<0.05);the treatment satisfaction of Group A was higher than that of Group B(P<0.05).Conclusion:Treatment of diarrhea-predominant IBS patients with spleen and stomach weakness by Shengyang Yiwei Decoction can promote the disappearance of gastrointestinal discomfort symptoms,improve the quality of life,and enhance treatment efficacy.Hence,it is an efficient and feasible treatment for diarrhea-predominant IBS due to spleen and stomach weakness. 展开更多
关键词 Diarrhea-predominant Spleen and stomach weakness Irritable bowel syndrome Shengyang Yiwei Decoction EFFICACY
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Studies on Novel Anti-jamming Technique of Unmanned Aerial Vehicle Data Link 被引量:7
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作者 黄文准 王永生 叶向阳 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2008年第2期141-148,共8页
Based on the M-ary spread spectrum (M-ary-SS), direct sequence spread spectrum (DS-SS), and orthogonal frequency division multiplex (OFDM), a novel anti-jamming scheme, named orthogonal code time division multi-... Based on the M-ary spread spectrum (M-ary-SS), direct sequence spread spectrum (DS-SS), and orthogonal frequency division multiplex (OFDM), a novel anti-jamming scheme, named orthogonal code time division multi-subchannels spread spectrum modulation (OC-TDMSCSSM), is proposed to enhance the anti-jamming ability of the unmanned aerial vehicle (UAV) data link. The anti-jamming system with its mathematical model is presented first, and then the signal formats of transmitter and receiver are derived. The receiver's bit error rate (BER) is demonstrated and anti-jamming performance analysis is carded out in an additive white Ganssian noise (AWGN) channel. Theoretical research and simulation results show the anti-jamming performance of the proposed scheme better than that of the hybrid direct sequence frequency hopping spread spectrum (DS/FH SS) system. The jamming margin of the OC-TDMSCSSM system is 5 dB higher than that of DS/FH SS system under the condition of Rician channel and full-band jamming, and 6 dB higher under the condition of Rician channel environment and partial-band jamming. 展开更多
关键词 UAV data link OC-TDMSCSSM systemview simulation orthogonal code anti-jamming
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Histological Effects of Guchangcuzhang Powder on Intestine and Spleen in Experimental Piglets with Spleen Weakness
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作者 史秋梅 高桂生 +3 位作者 沈萍 高光平 张艳英 邵欣华 《Agricultural Science & Technology》 CAS 2013年第8期1174-1177,共4页
[Objective] This study aimed to explore the histological effects of Guchangcuzhang powder on intestine and spleen in experiment piglets with spleen weakness.[Method] The 12 piglets with diarrhea were divided into two ... [Objective] This study aimed to explore the histological effects of Guchangcuzhang powder on intestine and spleen in experiment piglets with spleen weakness.[Method] The 12 piglets with diarrhea were divided into two groups,namely the Guchangcuzhang powder group and the control group,six in each.On two and eight days after the drug discontinuance respectively,three piglets were selected from each of the group and killed by bloodletting from the jugular vein.Afterwards,paraffin sections of intestine and spleen were made and stained by HE staining solution,followed by observation of the histological changes.[Result] The structures of intestine and spleen in piglets drenched with Guchangcuzhang powder restored or approachedto normal.[Conlusion] Guchangcuzhang powder has the function of healing piglet diarrhea. 展开更多
关键词 PIGLETS Guchangcuzhang powder Spleen weakness and diarrhea Histology
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Strength and Weakness of Eco-agricultural Sightseeing Development in Baise City and Corresponding Strategies
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作者 李英策 《Journal of Landscape Research》 2010年第8期68-71,75,共5页
The development of eco-agricultural sightseeing in Baise City shows a sound foundation and outstanding advantages as well as a rapid growth trend in recent years, however, there are also problems to be settled, such a... The development of eco-agricultural sightseeing in Baise City shows a sound foundation and outstanding advantages as well as a rapid growth trend in recent years, however, there are also problems to be settled, such as shortage of talents, insufficient planning, low level of development, limited products and lack of competitive products. In view of such a condition, development concepts should be reformed first, competitive and special products made, marketing and propaganda enhanced to promote the healthy, coordinated and ordered development of eco-agricultural sightseeing in Baise City, Guangxi Zhuang Nationality Autonomous Region. 展开更多
关键词 Eco-agriculture SIGHTSEEING TOUR STRENGTH weakness Strategy
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Weaknesses of Chomsky's Theory of Language
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作者 鲍志坤 《海外英语》 2013年第13期1-3,共3页
As seemingly persuasive as Chomsky's theory is, it is significantly flawed in four aspects: 1. ignoring a much fundamental creative force in early infancy; 2. equation of first-language learning with second-langua... As seemingly persuasive as Chomsky's theory is, it is significantly flawed in four aspects: 1. ignoring a much fundamental creative force in early infancy; 2. equation of first-language learning with second-language learning; 3. methodology; 4. employment of terms. 展开更多
关键词 weaknesses Chomsky’s THEORY of LANGUAGE
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Azimuthal elastic impedance-based Fourier coefficient variation with angle inversion for fracture weakness 被引量:10
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作者 Lin Li Jia-Jia Zhang +1 位作者 Xin-Peng Pan Guang-Zhi Zhang 《Petroleum Science》 SCIE CAS CSCD 2020年第1期86-104,共19页
Quantitative inversion of fracture weakness plays an important role in fracture prediction.Considering reservoirs with a set of vertical fractures as horizontal transversely isotropic media,the logarithmic normalized ... Quantitative inversion of fracture weakness plays an important role in fracture prediction.Considering reservoirs with a set of vertical fractures as horizontal transversely isotropic media,the logarithmic normalized azimuthal elastic impedance(EI)is rewritten in terms of Fourier coefficients(FCs),the 90°ambiguity in the azimuth estimation of the symmetry axis is resolved by judging the sign of the second FC,and we choose the FCs with the highest sensitivity to fracture weakness and present a feasible inversion workflow for fracture weakness,which involves:(1)the inversion for azimuthal EI datasets from observed azimuthal angle gathers;(2)the prediction for the second FCs and azimuth of the symmetry axis from the estimated azimuthal EI datasets;and(3)the estimation of fracture weakness combining the extracted second FCs and azimuth of the symmetry axis iteratively,which is constrained utilizing the Cauchy sparse regularization and the low-frequency regularization in a Bayesian framework.Tests on synthetic and field data demonstrate that the 90°ambiguity in the azimuth estimation of the symmetry axis has been removed,and reliable fracture weakness can be obtained when the estimated azimuth of the symmetry axis deviates less than 30°,which can guide the prediction of fractured reservoirs. 展开更多
关键词 FRACTURE weakness AZIMUTH of the SYMMETRY axis Azimuthal FOURIER COEFFICIENTS HTI Azimuthal elastic impedance
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Strengths, weaknesses, opportunities and threats (SWOT) analysis of reinitiation into methamphetamine abusers: qualitative findings from an exploration of methamphetamine abusers in Shanghai, China 被引量:10
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作者 Youwei Zhu Na Zhong +8 位作者 Hang Su Xiaolu Ruan Jiayi Bao Lei Zhang Jiang Du Ding Xu Rongjie Ding Ke Xiao Min Zhao 《General Psychiatry》 CSCD 2019年第3期137-145,共9页
Background Despite high relapse rate among methamphetamine (MA) abusers, there still have been little empirical data to date detecting the risk factors related to craving and relapse from the perspective of MA abusers... Background Despite high relapse rate among methamphetamine (MA) abusers, there still have been little empirical data to date detecting the risk factors related to craving and relapse from the perspective of MA abusers. Therefore, the aim of this study was to use qualitative research methods exploring the strengths, weaknesses, opportunities and threat factors that could facilitate or impede individuals' abstinence in a real-life context from the perspectives of MA abusers. Aim To use qualitative research methods exploring the strengths, weaknesses, opportunities and threat factors relating to individuals' abstinence in a real-life context. Method Semistructured interviews were conducted with 32 MA abusers recruited in Shanghai guided by open-ended questions on narrating the real-life catalysts and inhibitors related to craving, initiation, relapse and abstinence. All data were transcribed verbatim and analysed using a strengths, weaknesses, opportunities and threats (SWOT) analysis. Results The results of the SWOT analysis revealed that contextual factors including peer influence, prevalence and availability of MA, familiar venue of MA use, discrimination, sexual behaviours, alcohol, emotional states and their attitudes towards smoking MA were important factors that contribute to reinitiation and relapse. Surveillance systems, antidrug social workers, vocational skills trainings, moving to another city and family responsibility might serve as counter measures targeti叩 those mentioned weaknesses and threats above. Conclusion This SWOT analysis highlights the complex nature of relapse. Comprehensive interventions strengtheni叩 coping skills such as virtual reality techniques are desperately needed to facilitate individuals1 sustained abstinence. 展开更多
关键词 Strengths weaknesses OPPORTUNITIES
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GNSS array receiver faced with overloaded interferences:anti-jamming performance and the incident directions of interferences 被引量:4
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作者 WANG Jie LIU Wenxiang +2 位作者 CHEN Feiqiang LU Zukun OU Gang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2023年第2期335-341,共7页
Anti-jamming solutions based on antenna arrays enhance the anti-jamming ability and the robustness of global navigation satellite system(GNSS)receiver remarkably.However,the performance of the receiver will deteriorat... Anti-jamming solutions based on antenna arrays enhance the anti-jamming ability and the robustness of global navigation satellite system(GNSS)receiver remarkably.However,the performance of the receiver will deteriorate significantly in the overloaded interferences scenario.We define the overloaded interferences scenario as where the number of interferences is more than or equal to the number of antenna arrays elements.In this paper,the effect mechanism of interferences with different incident directions is found by studying the anti-jamming performance of the adaptive space filter.The theoretical analysis and conclusions,which are first validated through numerical examples,reveal the relationships between the optimal weight vector and the eigenvectors of the input signal autocorrelation matrix,the relationships between the interference cancellation ratio(ICR),the signal to interference and noise power ratio(SINR)of the adaptive space filter output and the number of interferences,the eigenvalues of the input signal autocorrelation matrix.In addition,two simulation experiments are utilized to further corroborate the theoretical findings through soft anti-jamming receiver.The simulation results match well with the theoretical analysis results,thus validating the effect mechanism of overloaded interferences.The simulation results show that,for a four elements circular array,the performance difference is up to 19 dB with different incident directions of interferences.Anti-jamming performance evaluation and jamming deployment optimization can obtain more accurate and efficient results by using the conclusions. 展开更多
关键词 antenna arrays anti-jamming overloaded interferences incident direction
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