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Structural performance assessment of GFRP elastic gridshells by machine learning interpretability methods

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Frontiers of Structural and Civil Engineering 2022年第10期16卷 1249-1266页

作者： Soheila KOOKALANI Bin CHENG Jose luis chavez TORRES Department of Civil Engineering Shanghai Jiao Tong UniversityShanghai 200240China Department of Civil Engineering Technical University of LojaLoja 110102Ecuador

The prediction of structural performance plays a significant role in damage assessment of glass fiber reinforcement polymer(GFRP)elastic gridshell *** learning(ML)approaches are implemented in this study,to predict maximum stress and displacement of GFRP elastic gridshell *** ML algorithms,including linear regression(LR),ridge regression(RR),support vector regression(SVR),K-nearest neighbors(KNN),decision tree(DT),random forest(RF),adaptive boosting(AdaBoost),extreme gradient boosting(XGBoost),category boosting(CatBoost),and light gradient boosting machine(LightGBM),are implemented in this *** features of structural performance considered in this study are the maximum stress as f1(x)and the maximum displacement to self-weight ratio as f2(x).A comparative study is conducted and the Catboost model presents the highest prediction ***,interpretable ML approaches,including shapely additive explanations(SHAP),partial dependence plot(PDP),and accumulated local effects(ALE),are applied to explain the *** is employed to describe the importance of each variable to structural performance both locally and *** results of sensitivity analysis(SA),feature importance of the CatBoost model and SHAP approach indicate the same parameters as the most significant variables for f1(x)and f2(x).

关键词： machine learning gridshell structure regression sensitivity analysis interpretability methods

Hepatic hemangioma:What internists need to know

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World Journal of Gastroenterology 2020年第1期26卷 11-20页

作者： Monica Leon luis chavez Salim Surani Centro Medico ABC Ciudad de MexicoCDMX 01120Mexico Department of Internal Medicine Texas Tech University Health Sciences CenterEl PasoTX 79905United States Texas A&M University Corpus ChristiTX 78405United States

Hepatic hemangioma(HH)is the most common benign liver tumor and it is usually found incidentally during radiological *** tumor arises from a vascular malformation;however,the pathophysiology has not been clearly *** usually correlate with the size and location of the *** commonly the presence of a large HH may cause life-threatening *** diagnosis can be established by the identification of HH hallmarks in several imaging *** patients that present with abdominal symptoms other etiologies should be excluded first before attributing HH as the *** asymptomatic patient’s treatment is not required and follow up is usually reserved for HH of more than 5 *** patients can be managed surgically or with other non-surgical modalities such as transcatheter arterial embolization or radiofrequency *** surgery has shown to have fewer complications as compared to hepatectomy or other surgical *** of the tumor is seen in less than 40%.Hormone stimulation may play a role in HH growth;however,there are no contraindications for hormonal therapy in patients with HH due to the lack of concrete *** clinicians encounter this condition,they should discern between observation and surgical or non-surgical management based on the clinical presentation.

关键词： Hepatic hemangioma Liver masses Liver Vascular lesion

Abdominal compartment syndrome among surgical patients

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World Journal of Gastrointestinal Surgery 2021年第4期13卷 330-339页

作者： Monica Leon luis chavez Salim Surani Department of Medicine Centro Medico ABCCiudad de Mexico 01120Mexico Department of Medicine University of TexasEl PasoTX 79905United States Department of Medicine Texas A&M UniversityCorpus ChristiTX 78405United States

Abdominal compartment syndrome(ACS)develops when organ failure arises secondary to an increase in intraabdominal *** abdominal pressure is determined by multiple factors such as blood pressure,abdominal compliance,and other factors that exert a constant pressure within the abdominal *** conditions in the critically ill may increase abdominal pressure compromising organ perfusion that may lead to renal and respiratory *** surgical and trauma patients,aggressive fluid resuscitation is the most commonly reported risk factor to develop *** conditions that have also been identified as risk factors are ascites,hemoperitoneum,bowel distention,and large *** patients with abdominal trauma possess a higher risk of developing intra-abdominal hypertension(IAH).Certain surgical interventions are reported to have a higher risk to develop IAH such as damage control surgery,abdominal aortic aneurysm repair,and liver transplantation among *** monitoring of organ function and intra-abdominal pressure(IAP)allows clinicians to diagnose ACS rapidly and intervene with target-specific management to reduce *** decompression followed by temporary abdominal closure should be considered in all patients with signs of organ *** is still a great need for more studies to determine the adequate timing for interventions to improve patient outcomes.

关键词： Intra-abdominal hypertension Abdominal compartment syndrome Intraabdominal pressure Open abdomen treatment Multiple organ failure Surgical decompression

Ligation of intersphincteric fistula tract:What is the evidence in a review?

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World Journal of Gastroenterology 2013年第40期19卷 6805-6813页

作者： omar Vergara-Fernandez luis Alberto Espino-Urbina Department of Colorectal Surgery Instituto Nacional de Ciencias Medicas y Nutricion "Salvador Zubiran"14000 Mexico CityMexico

Broadly,complex fistulas are those that are not low transsphincteric or intersphincteric. The objectives of surgical management are to achieve fistula healing,prevent recurrences and maintain continence. The risk of incontinence associated with treatment ranges from10% to 57%. The objective of this manuscript is to review the current literature to date on the ligation of the intersphincteric fistula tract procedure(LIFT procedure) as a treatment option in these types of fistula.A search was conducted in Medline,PUBMED,EMBASE and ISI Web of Knowledge,and studies published from January 2009 to May 2013 were included. The primary outcomes were fistula healing rates,mean healing time and patient satisfaction with this surgical *** studies were included in this review. The total number of patients included was 592(65% male).The median age reported was 42.8 years. The most common type of fistula included was transsphincteric(73.3% of cases). The mean healing rate reported was74.6%. The risk factors for failure discovered were obesity,smoking,multiple previous surgeries and the length of the fistula tract. The mean healing time was5.5 wk,and the mean follow-up period was 42.3 *** patient satisfaction rates ranged from 72% to 100%. No de novo incontinence developed secondary to the LIFT procedure. There is not enough evidence that variants in the surgical technique achieve better outcomes(Bio-LIFT,LIFT-Plug,LIFT-Plus). This review indicates that the LIFT procedure is primarily effective for transsphincteric fistulas with an overall fistula closure of 74.6% and has a low impact on fecal continence. This procedure produces better outcomes at the first surgical attempt.

关键词： Fistula-in-ano Ligation Intersphincteric Fistula tract Incontinence Recurrence Transsphincteric fistula

Sintering study of Ti6Al4V powders with different particle sizes and their mechanical properties

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International Journal of Minerals,Metallurgy and Materials 2018年第12期25卷 1389-1401页

作者： Joséluis Cabezas-Villa JoséLemus-Ruiz Didier Bouvard omar Jiménez Héctor Javier Vergara-Hernández luis Olmos University Michoacana of San Nicolás of Hidalgo IIMMMorelia 58060México University Grenoble Alpes CNRSSIMaPGrenoble 38000France University of Guadalajara Departamento de Ingeniería de ProyectosZapopan 45100México National Technological Institute of Mexico I.T.MoreliaMorelia 58120México University Michoacana of San Nicolás of Hidalgo INICITMorelia 58060México

Ti6Al4V powders with three different particle size distributions(0–20, 20–45, and 45–75 μm) were used to evaluate the effect of the particle size distribution on the solid-state sintering and their mechanical properties. The sintering kinetics was determined by dilatometry at temperatures from 900 to 1260°C. The mechanical properties of the sintered samples were evaluated by microhardness and compression tests. The sintering kinetics indicated that the predominant mechanism depends on the relative density irrespective of the particle size used. The mechanical properties of the sintered samples are adversely affected by increasing pore volume fraction. The elastic Young's modulus and yield stress follow a power law function of the relative density. The fracture behavior after compression is linked to the neck size developed during sintering, exhibiting two different mechanisms of failure: interparticle neck breaking and intergranular cracking in samples with relative densities below and above of 90%, respectively. The main conclusion is that relative density is responsible for the kinetics, mechanical properties, and failure behavior of Ti6 Al4 V powders.

关键词： Ti6Al4V powders dilatometry microhardness sintering kinetics compression failure behavior

Perinuclear anti-neutrophil cytoplasmic antibodies (p-anca) in chronic ulcerative colitis: Experience in a Mexican institution

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World Journal of Gastroenterology 2006年第21期12卷 3406-3409页

作者： Jesus K Yamamoto-Furusho Takeshi Takahashi-Monroy omar Vergara-Fernandez Edgardo Reyes luis Uscanga Departments of Gastroenterology. Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran Mexico City Mexico Departments of Surgery. Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran Mexico City Mexico Departments of Pathology. Institute Nacional de Ciencias Medicas y Nutricion Salvador Zubiran Mexico City Mexico

AIM： To assess the prevalence and clinical value of p-ANCA in a sample of Mexican ulcerative colitis （UC） patients. METHODS： In a prospective, IRB-approved protocol, p-ANCA was determined in 80 patients with UC （mean age, 32 ± 12.9 years）. The severity and extension of disease were determined by clinical methods, searching a statistical association with p-ANCA status. RESULTS： p-ANCA were detected in 41 （51%） patients. Severity of disease was the only clinical variable statistically associated with their presence （P 〈 0.0001; OR = 9; CI 95% = 3.2-24.7）. CONCLUSION： The prevalence of p-ANCA was similar to that reported in other countries. Their presence was associated to UC severity, but offered no more information than the obtained by clinical methods.

关键词： Ulcerative colitis Inflammatory bowel disease Perinuclear anti-neutrophil cytoplasmic antibodies

Grain yield losses in yellow-rusted durum wheat estimated using digital and conventional parameters under field conditions

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The Crop Journal 2015年第3期3卷 200-210页

作者： omar Vergara-Diaz Shawn C.Kefauver Abdelhalim Elazab Maria Teresa Nieto-Taladriz Jose luis Araus Unit of Plant Physiology Department of Plant BiologyFaculty of BiologyUniversity of BarcelonaDiagonal 64508028 BarcelonaSpain National Institute for Agricultural and Food Research and Technology(INIA) Ctra de la Coruna 7.528040Madrid Spain

The biotrophic fungus Puccinia striiformis f. sp. tritici is the causal agent of the yellow rust in wheat. Between the years 2010–2013 a new strain of this pathogen(Warrior/Ambition),against which the present cultivated wheat varieties have no resistance, appeared and spread rapidly. It threatens cereal production in most of Europe. The search for sources of resistance to this strain is proposed as the most efficient and safe solution to ensure high grain production. This will be helped by the development of high performance and low cost techniques for field phenotyping. In this study we analyzed vegetation indices in the Red,Green, Blue(RGB) images of crop canopies under field conditions. We evaluated their accuracy in predicting grain yield and assessing disease severity in comparison to other field measurements including the Normalized Difference Vegetation Index(NDVI), leaf chlorophyll content, stomatal conductance, and canopy temperature. We also discuss yield components and agronomic parameters in relation to grain yield and disease ***-based indices proved to be accurate predictors of grain yield and grain yield losses associated with yellow rust(R2= 0.581 and R2= 0.536, respectively), far surpassing the predictive ability of NDVI(R2= 0.118 and R2= 0.128, respectively). In comparison to potential yield, we found the presence of disease to be correlated with reductions in the number of grains per spike, grains per square meter, kernel weight and harvest index. Grain yield losses in the presence of yellow rust were also greater in later heading varieties. The combination of RGB-based indices and days to heading together explained 70.9% of the variability in grain yield and 62.7% of the yield losses.

关键词： Wheat yellow rust Field phenotyping NDVI Phenology,Puccinia striiformis RGB-based indices Triticum durum

Abnormal liver enzymes: A review for clinicians

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World Journal of Hepatology 2021年第11期13卷 1688-1698页

作者： M Ammar Kalas luis chavez Monica Leon Pahnwat Tonya Taweesedt Salim Surani Department of Internal Medicine Texas Tech University Health Science CenterEl PasoTX 79905United States Department of General Surgery University of MexicoCiudad de Mexico 01120Mexico Department of Medicine Corpus Christi Medical CenterCorpus ChristiTX 78412United States Department of Medicine Texas A&M UniversityCollege StationTX 77843United States Department of Anesthesiology Mayo ClinicRochesterMN 55905United States

Liver biochemical tests are some of the most commonly ordered routine tests in the inpatient and outpatient setting,especially with the automatization of testing in this technological *** tests include aminotransferases,alkaline phosphatase,gamma-glutamyl transferase,bilirubin,albumin,prothrombin time and international normalized ratio(INR).Abnormal liver biochemical tests can be categorized based on the pattern and the magnitude of aminotransferases ***,abnormalities in aminotransferases can be classified into a hepatocellular pattern or cholestatic pattern and can be further sub-classified based on the magnitude of aminotransferase elevation to mild[5-15×ULN).Hepatocellular pattern causes include but are not limited to;non-alcoholic fatty liver disease/non-alcoholic steatohepatitis,alcohol use,chronic viral hepatitis,liver cirrhosis(variable),autoimmune hepatitis,hemochromatosis,Wilson’s disease,alpha-1 antitrypsin deficiency,celiac disease,medication-induced and ischemic *** pattern causes include but is not limited to;biliary pathology(obstruction,autoimmune),other conditions with hyperbilirubinemia(conjugated and unconjugated).It is crucial to interpret these commonly ordered tests accurately as appropriate further workup,treatment and referral can greatly benefit the patient due to prompt treatment which can improve the natural history of several of the diseases mentioned and possibly reduce the risk of progression to the liver cirrhosis.

关键词： Liver function test Liver enzymes Hepatitis Liver biochemical studies Nonalcoholic steatohepatitis Hyperbilirubenemia

Evolution of wheat architecture,physiology,and metabolism during domestication and further cultivation:Lessons for crop improvement

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The Crop Journal 2023年第4期11卷 1080-1096页

作者： Arturs Katamadze omar Vergara-Díaz Estefanía Uberegui Ander Yoldi-Achalandabaso José luis Araus Rubén Vicente Plant Ecophysiology and Metabolism Group Instituto de Tecnologia Química e Biológica António XavierUniversidade Nova de LisboaP-2780 OeirasPortugal Genetics and Genomics of Plant Complex Traits Instituto de Tecnologia Química e Biológica António XavierUniversidade Nova de LisboaP-2780 OeirasPortugal FisioClimaCO_(2) Group Department of Plant Biology and EcologyFaculty of Science and TechnologyUniversity of the Basque CountryE-48940 LeioaSpain Integrative Crop Ecophysiology Group Section of Plant PhysiologyFaculty of BiologyUniversity of BarcelonaE-08028 Barcelona&AGROTECNIO-CERCA CenterE-25198 LleidaSpain

In recent decades,genetic advances in yield improvement in the major cereal crops,including wheat,has stagnated or proceeded at a slower rate than is required to meet future global food demand,particularly in the face of climate *** reverse this situation,and in view of the future climate scenario,there is a need to increase the genetic diversity of wheat to increase its productivity,quality,stability,and adaptation to local *** abundant genetic resources and literature are a basis for wheat ***,many species,such as wild relatives,landraces,and old cultivars have not been studied beyond their agronomic characteristics,highlighting the lack of understanding of the physiological and metabolic processes(and their integration) associated with higher productivity and resilience in limiting *** studies using wheat ancestors and modern cultivars may identify novel traits that have not previously been considered,or have been underestimated,during domestication and breeding,but that may contribute to future food *** review describes existing wheat genetic diversity and changes that occurred during domestication and breeding,and considers whether mining natural variation among wheat ancestors offers an opportunity to enhance wheat agronomic performance,spike architecture,canopy-and organ-level photosynthetic capacity,and responses to abiotic stress,as well as to develop new wheat hybrids.

关键词： Breeding Landraces Photosynthesis Wild relatives Yield