91,368 results match your criteria gradient method

Computer-assisted UHPLC method development and optimization for the determination of albendazole and its related substances.

J Pharm Biomed Anal 2021 Jun 11;203:114203. Epub 2021 Jun 11.

George Emil Palade University of Medicine, Pharmacy, Science, and Technology of Targu Mures, Gh. Marinescu 38, RO-540139, Tîrgu Mureș, Romania; Sz-imfidum Ltd, RO-525401, Lunga No. 504, Romania. Electronic address:

Computer-aided ultrahigh performance liquid chromatographic (UHPLC) method development and optimization was undertaken in order to replace an underperforming European Pharmacopoeia method for the determination of albendazole and its related substances. In the preliminary screening, a temperature-gradient time bidimensional model was chosen to aid selection of the proper stationary phase. Hereinafter temperature-gradient time-ternary composition and temperature-gradient time-pH tridimensional models were applied for the optimization of critical method parameters. Read More

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Conditional generation of medical images via disentangled adversarial inference.

Med Image Anal 2021 May 24;72:102106. Epub 2021 May 24.

Imagia, Canada; Montréal Institute for Learning Algorithms (MILA), Université de Montréal, Canada; West China Biomedical Big Data Center, West China Hospital of Sichuan University, Chengdu, China. Electronic address:

Synthetic medical image generation has a huge potential for improving healthcare through many applications, from data augmentation for training machine learning systems to preserving patient privacy. Conditional Adversarial Generative Networks (cGANs) use a conditioning factor to generate images and have shown great success in recent years. Intuitively, the information in an image can be divided into two parts: 1) content which is presented through the conditioning vector and 2) style which is the undiscovered information missing from the conditioning vector. Read More

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Ann Pharm Fr 2021 Jun 18. Epub 2021 Jun 18.

Aurobindo Pharma Limited, Bachupally, R.R District, Hyderabad, 500090, Telangana, India.

The basic objective of this study is to propose a short, reliable, mass compatible ultra-performance liquid chromatography (UPLC) method to confirm the identity of impurities and to estimate the assay and purity of Tirofiban simultaneously in aqueous injection (5 mg/100 mL bag). Aqueous formulations are susceptible to oxidation, hence the possible oxidative degradation impurities of Tirofiban were studied in this experiment by using UPLC coupled with Photodiode Array/Quadrupole Dalton Analyzer (PDA/QDa) detectors. The required separations were achieved in the column: ACQUITY HSS T3 (100 x 2. Read More

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Essential Protein Prediction Based on node2vec and XGBoost.

J Comput Biol 2021 Jun 21. Epub 2021 Jun 21.

School of Computer Science and Engineering, Central South University, Changsha, P.R. China.

Essential proteins are a vital part of the survival of organisms and cells. Identification of essential proteins lays a solid foundation for understanding protein functions and discovering drug targets. The traditional biological experiments are expensive and time-consuming. Read More

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Polysome Profiling without Gradient Makers or Fractionation Systems.

J Vis Exp 2021 Jun 1(172). Epub 2021 Jun 1.

Signal Transduction Laboratory, National Institute of Environmental Health Sciences, Department of Health and Human Services, National Institutes of Health;

Polysome fractionation by sucrose density gradient centrifugation is a powerful tool that can be used to create ribosome profiles, identify specific mRNAs being translated by ribosomes, and analyze polysome associated factors. While automated gradient makers and gradient fractionation systems are commonly used with this technique, these systems are generally expensive and can be cost-prohibitive for laboratories that have limited resources or cannot justify the expense due to their infrequent or occasional need to perform this method for their research. Here, a protocol is presented to reproducibly generate polysome profiles using standard equipment available in most molecular biology laboratories without specialized fractionation instruments. Read More

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A Change Talk Model for Abstinence Based on Web-Based Anonymous Gambler Chat Meeting Data by Using an Automatic Change Talk Classifier: Development Study.

Kenji Yokotani

J Med Internet Res 2021 Jun 21;23(6):e24088. Epub 2021 Jun 21.

Department of Clinical Psychology, Graduate School of Sciences and Technology for Innovation, Tokushima University, Tokushima-shi, Japan.

Background: Change and sustain talks (negative and positive comments) on gambling have been relevant for determining gamblers' outcomes but they have not been used to clarify the abstinence process in anonymous gambler meetings.

Objective: The aim of this study was to develop a change talk model for abstinence based on data extracted from web-based anonymous gambler chat meetings by using an automatic change talk classifier.

Methods: This study used registry data from the internet. Read More

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Use of Multiprognostic Index Domain Scores, Clinical Data, and Machine Learning to Improve 12-Month Mortality Risk Prediction in Older Hospitalized Patients: Prospective Cohort Study.

J Med Internet Res 2021 Jun 21;23(6):e26139. Epub 2021 Jun 21.

College of Medicine and Public Health, Flinders University, Adelaide, Australia.

Background: The Multidimensional Prognostic Index (MPI) is an aggregate, comprehensive, geriatric assessment scoring system derived from eight domains that predict adverse outcomes, including 12-month mortality. However, the prediction accuracy of using the three MPI categories (mild, moderate, and severe risk) was relatively poor in a study of older hospitalized Australian patients. Prediction modeling using the component domains of the MPI together with additional clinical features and machine learning (ML) algorithms might improve prediction accuracy. Read More

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Diverse Right Ventricular Remodeling Evaluated by MRI and Prognosis in Eisenmenger Syndrome With Different Shunt Locations.

J Magn Reson Imaging 2021 Jun 21. Epub 2021 Jun 21.

Department of Cardiology, West China Hospital, Sichuan University, Chengdu, PR China.

Background: Congenital shunt location is related to Eisenmenger syndrome (ES) survival. Moreover, right ventricular (RV) remodeling is associated with poor survival in pulmonary hypertension.

Purpose: To investigate RV remodeling using comprehensive magnetic resonance imaging (MRI) techniques and identify its relationship with prognosis in ES subgroups classified by shunt location. Read More

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PolSIRD: Modeling Epidemic Spread Under Intervention Policies: Analyzing the First Wave of COVID-19 in the USA.

J Healthc Inform Res 2021 Jun 14:1-18. Epub 2021 Jun 14.

Department of Computer Science, University of Southern California, Los Angeles, CA USA.

Epidemic spread in a population is traditionally modeled via compartmentalized models which represent the free evolution of disease in the absence of any intervention policies. In addition, these models assume full observability of disease cases and do not account for under-reporting. We present a mathematical model, namely PolSIRD, which accounts for the under-reporting by introducing an observation mechanism. Read More

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Calibrating models of cancer invasion: parameter estimation using approximate Bayesian computation and gradient matching.

R Soc Open Sci 2021 Jun 16;8(6):202237. Epub 2021 Jun 16.

School of Mathematics and Statistics, University of St Andrews, St Andrews, KY16 9SS UK.

We present two different methods to estimate parameters within a partial differential equation model of cancer invasion. The model describes the spatio-temporal evolution of three variables-tumour cell density, extracellular matrix density and matrix degrading enzyme concentration-in a one-dimensional tissue domain. The first method is a likelihood-free approach associated with approximate Bayesian computation; the second is a two-stage gradient matching method based on smoothing the data with a generalized additive model (GAM) and matching gradients from the GAM to those from the model. Read More

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Improving Risk Identification of Adverse Outcomes in Chronic Heart Failure Using SMOTE+ENN and Machine Learning.

Risk Manag Healthc Policy 2021 8;14:2453-2463. Epub 2021 Jun 8.

Department of Health Statistics, School of Public Health, Shanxi Medical University, Taiyuan, People's Republic of China.

Purpose: This study sought to develop models with good identification for adverse outcomes in patients with heart failure (HF) and find strong factors that affect prognosis.

Patients And Methods: A total of 5004 qualifying cases were selected, among which 498 cases had adverse outcomes and 4506 cases were discharged after improvement. The study subjects were hospitalized patients diagnosed with HF from a regional cardiovascular hospital and the cardiology department of a medical university hospital in Shanxi Province of China between January 2014 and June 2019. Read More

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A novel restricted single-isocenter stereotactic body radiotherapy (RESIST) method for synchronous multiple lung lesions to minimize setup uncertainties.

Med Dosim 2021 Jun 17. Epub 2021 Jun 17.

Medical Physics Graduate Program, Department of Radiation Oncology, University of Kentucky, Lexington KY, USA.

Treating multiple lung lesions synchronously using a single-isocenter volumetric modulated arc therapy (VMAT) stereotactic body radiation therapy (SBRT) plan can improve treatment efficiency and patient compliance. However, due to set up uncertainty, aligning multiple lung tumors on a single daily cone beam CT (CBCT) image has shown clinically unacceptable loss of target(s) coverage. Herein, we propose a Restricted Single-Isocenter Stereotactic Body Radiotherapy (RESIST), an alternative treatment that mitigates patient setup uncertainties. Read More

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A real-world application of Markov chain Monte Carlo method for Bayesian trajectory control of a robotic manipulator.

ISA Trans 2021 Jun 9. Epub 2021 Jun 9.

Sabanci University, Faculty of Engineering and Natural Sciences, Mechatronics Engineering, Orhanli, Tuzla, Istanbul, Turkey. Electronic address:

Reinforcement learning methods are being applied to control problems in robotics domain. These algorithms are well suited for dealing with the continuous large scale state spaces in robotics field. Even though policy search methods related to stochastic gradient optimization algorithms have become a successful candidate for coping with challenging robotics and control problems in recent years, they may become unstable when abrupt variations occur in gradient computations. Read More

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The advanced machine learner XGBoost did not reduce prehospital trauma mistriage compared with logistic regression: a simulation study.

BMC Med Inform Decis Mak 2021 Jun 21;21(1):192. Epub 2021 Jun 21.

Department of Global Public Health, Karolinska Institutet, 171 77, Solna, Sweden.

Background: Accurate prehospital trauma triage is crucial for identifying critically injured patients and determining the level of care. In the prehospital setting, time and data are often scarce, limiting the complexity of triage models. The aim of this study was to assess whether, compared with logistic regression, the advanced machine learner XGBoost (eXtreme Gradient Boosting) is associated with reduced prehospital trauma mistriage. Read More

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Review of cluster analysis of phenotypic data in Autism Spectrum Disorders: distinct subtypes or a severity gradient model?

Int J Dev Disabil 2019 Jan 15;66(1):13-21. Epub 2019 Jan 15.

Department of Educational and Social Policy, University of Macedonia, Thessaloniki, Greece.

Individuals with autism spectrum disorder (ASD) form a heterogeneous group, posing a challenge for clinical definition. Additional problems regarding the diverse clinical presentation arise from changes in diagnostic criteria according to the latest Diagnostic and Statistical Manual of Mental Disorders (DSM-5), with exclusion of individuals who met earlier criteria or inclusion of more than previously. To investigate studies that have attempted to reduce the heterogeneity of ASD based on cluster analysis of phenotypic data and to clarify whether ASD should be interpreted as 'a unitary spectrum,' with a severity gradient, or defined by distinct subtypes. Read More

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January 2019

Low oxygen tension potentiates proliferation and stemness but not multilineage differentiation of caprine male germline stem cells.

Mol Biol Rep 2021 Jun 20. Epub 2021 Jun 20.

ICAR-National Dairy Research Institute, Karnal, Haryana, 132001, India.

The milieu of male germline stem cells (mGSCs) is characterized as a low-oxygen (O) environment, whereas, their in-vitro expansion is typically performed under normoxia (20-21% O). The comparative information about the effects of low and normal O levels on the growth and differentiation of caprine mGSCs (cmGSCs) is lacking. Thus, we aimed to investigate the functional and multilineage differentiation characteristics of enriched cmGSCs, when grown under hypoxia and normoxia. Read More

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The ACURATE neo2 valve system for transcatheter aortic valve implantation: 30-day and 1-year outcomes.

Clin Res Cardiol 2021 Jun 20. Epub 2021 Jun 20.

Department of Cardiology/Cardiac Surgery, Kerckhoff Heart Centre, Bad Nauheim, Germany.

Background: Transcatheter aortic valve implantation (TAVI) has become standard treatment for elderly patients with symptomatic severe aortic valve stenosis. The ACURATE neo AS study evaluates 30-day and 1-year clinical and hemodynamic outcomes in patients treated with the ACURATE neo2 valve.

Methods: The primary endpoint of this single-arm multicenter study is 30-day all-cause mortality. Read More

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Cardiac-induced liver deformation as a measure of liver stiffness using dynamic imaging without magnetization tagging-preclinical proof-of-concept, clinical translation, reproducibility and feasibility in patients with cirrhosis.

Abdom Radiol (NY) 2021 Jun 20. Epub 2021 Jun 20.

Division of Medicine, Centre for Medical Imaging, University College London (UCL), London, UK.

Purpose: MR elastography and magnetization-tagging use liver stiffness (LS) measurements to diagnose fibrosis but require physical drivers, specialist sequences and post-processing. Here we evaluate non-rigid registration of dynamic two-dimensional cine MRI images to measure cardiac-induced liver deformation (LD) as a measure of LS by (i) assessing preclinical proof-of-concept, (ii) clinical reproducibility and inter-reader variability, (iii) the effects of hepatic hemodynamic changes and (iv) feasibility in patients with cirrhosis.

Methods: Sprague-Dawley rats (n = 21 bile duct ligated (BDL), n = 17 sham-operated controls) and fasted patients with liver cirrhosis (n = 11) and healthy volunteers (HVs, n = 10) underwent spoiled gradient-echo short-axis cardiac cine MRI studies at 9. Read More

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A validated LC-MS/MS assay for the quantification of phosphodiesterase-5 inhibitors in human plasma.

J Chromatogr B Analyt Technol Biomed Life Sci 2021 Jun 12;1179:122829. Epub 2021 Jun 12.

Universidade Federal do Paraná, Department of Pharmacy, 632 Lothário Meissner Avenue, 80210-170 Curitiba, PR, Brazil. Electronic address:

Phosphodiesterase inhibitors (PDE5i) are considered the first line therapy for erectile dysfunction. All PDE5i available on the market are structurally related; their main differences relate to their pharmacokinetic parameters. For these treatments to be effective and safe, it is necessary that these drugs are in the appropriate doses and that they reach adequate concentrations in the plasma. Read More

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Effectiveness of different types of Masks in Aerosol Dispersion in SARS-CoV-2 Infection.

Int J Infect Dis 2021 Jun 17. Epub 2021 Jun 17.

Koc University, School of Medicine, Department of Infectious Diseases and Clinical Microbiology, Istanbul, Turkey; Koc University Isbank Center for Infectious Diseases (KUISCID), Istanbul, Turkey. Electronic address:

Objective: We aimed to compare the effectiveness of different masks in limiting the dispersion of coughed air.

Method: We employed the single-curved mirror Schlieren method. Coughed air with a slightly higher temperature than the ambient air generates a refractive index gradient. Read More

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Optimized gradient spoiling of UTE VFA-AFI sequences for robust T estimation with B-field correction.

Magn Reson Imaging 2021 Jun 17. Epub 2021 Jun 17.

Medical Physics Group, Institute of Diagnostic and Interventional Radiology, Jena University Hospital - Friedrich Schiller University Jena, Germany. Electronic address:

Quantifying T relaxation times is a challenge because inhomogeneities of the B field have to be corrected to obtain proper values. It is a particular challenge in tissues with short T values, for which conventional MRI techniques do not provide sufficient signal. Recently, a B-field correction technique called AFI (Actual Flip angle Imaging) has been introduced that can be combined with UTE (ultra-short echo-time) sequences, which have much shorter echo times compared to conventional MRI techniques, allowing quantification of signal in short T tissues. Read More

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Respiratory triggered diffusion-weighted imaging with a single diffusion sensitising gradient to reduce image acquisition time - A feasibility study in the workup of hepatocellular carcinoma.

Eur J Radiol 2021 Jun 3;141:109807. Epub 2021 Jun 3.

Department of Radiodiagnosis, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029, India. Electronic address:

Purpose: We evaluated respiratory triggered unidirectional single-shot echo-planar imaging (u-SSEPI) as a time-saving measure in diffusion imaging of the upper abdomen. Specifically, we compared the ADC values obtained from unidirectional DWI (u-SSEPI) and routine DWI (4t-SSEPI) and also the diagnostic accuracies of unidirectional and routine DWI sequences in the identification of focal liver lesions in the setting of chronic liver disease (CLD).

Materials And Methods: This prospective, IRB approved study, included 48 patients of CLD who underwent-DCE-MRI on a 1. Read More

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Fast Numerical Optimization for Genome Sequencing Data in Population Biobanks.

Bioinformatics 2021 Jun 19. Epub 2021 Jun 19.

Department of Statistics, Stanford University, Stanford, 94305, United States.

Motivation: Large-scale and high-dimensional genome sequencing data poses computational challenges. General purpose optimization tools are usually not optimal in terms of computational and memory performance for genetic data.

Results: We develop two efficient solvers for optimization problems arising from large-scale regularized regressions on millions of genetic variants sequenced from hundreds of thousands of individuals. Read More

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[Prediction of intensive care unit readmission for critically ill patients based on ensemble learning].

Beijing Da Xue Xue Bao Yi Xue Ban 2021 Jun;53(3):566-572

National Institute of Health Data Science, Peking University, Beijing 100191, China.

Objective: To develop machine learning models for predicting intensive care unit (ICU) readmission using ensemble learning algorithms.

Methods: A publicly accessible American ICU database, medical information mart for intensive care (MIMIC)-Ⅲ as the data source was used, and the patients were selected by the inclusion and exclusion criteria. A set of variables that had the predictive ability of outcome including demographics, vital signs, laboratory tests, and comorbidities of patients were extracted from the dataset. Read More

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Event-based backpropagation can compute exact gradients for spiking neural networks.

Sci Rep 2021 Jun 18;11(1):12829. Epub 2021 Jun 18.

Kirchhoff-Institute for Physics, Heidelberg University, 69120, Heidelberg, Germany.

Spiking neural networks combine analog computation with event-based communication using discrete spikes. While the impressive advances of deep learning are enabled by training non-spiking artificial neural networks using the backpropagation algorithm, applying this algorithm to spiking networks was previously hindered by the existence of discrete spike events and discontinuities. For the first time, this work derives the backpropagation algorithm for a continuous-time spiking neural network and a general loss function by applying the adjoint method together with the proper partial derivative jumps, allowing for backpropagation through discrete spike events without approximations. Read More

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[Impact of socioeconomic factors on blood pressure control: Observational study about 2887 hypertensive patients].

Ann Cardiol Angeiol (Paris) 2021 Jun 15. Epub 2021 Jun 15.

Service de cardiologie, centre hospitalo-universitaire Hèdi-Chaker, Sfax, Tunisie.

Introduction: Despite therapeutic progress, less than half of hypertensive patients are controlled. The objective of this study was to examine the links between blood pressure control and socioeconomic factors.

Methods: We used data collected in the cardiology department of Sfax University Hospital as part of the Tunisian national hypertension registry. Read More

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Immediate outcomes of low-pressure balloon valvuloplasty for severe pulmonary valve stenosis in 20 dogs: a retrospective, single-center case series.

J Vet Cardiol 2021 May 21;36:99-104. Epub 2021 May 21.

College of Veterinary Medicine, Michigan State University, 784 Wilson Rd, East Lansing, MI, 48824, USA. Electronic address:

Introduction: The primary objective of this study was to describe the immediate post-procedural outcomes in dogs with severe pulmonary stenosis that were treated with low-pressure balloon valvuloplasty (BV) at a single institution.

Animals, Materials And Methods: Retrospective case series; medical records of dogs that underwent BV performed with a balloon dilation catheter >20 mm in diameter and a burst pressure of less than 4 atm (atm) were retrospectively reviewed. Twenty animals were identified fitting the criteria. Read More

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Effectiveness of resampling methods in coping with imbalanced crash data: Crash type analysis and predictive modeling.

Accid Anal Prev 2021 Jun 16;159:106240. Epub 2021 Jun 16.

College of Engineering, University of Georgia, Athens, GA 30602, USA. Electronic address:

Crash data analysis is commonly subjected to imbalanced data. Varied by facility and control types, some crash types are more frequent than others. However, uncommon crash types are routinely more severe and associated with higher economic and societal costs, and thus crucial to prevent. Read More

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Predictors of tooth loss: A machine learning approach.

PLoS One 2021 18;16(6):e0252873. Epub 2021 Jun 18.

Department of Epidemiology, University of Sao Paulo Public Health School, Sao Paulo, Brazil.

Introduction: Little is understood about the socioeconomic predictors of tooth loss, a condition that can negatively impact individual's quality of life. The goal of this study is to develop a machine-learning algorithm to predict complete and incremental tooth loss among adults and to compare the predictive performance of these models.

Methods: We used data from the National Health and Nutrition Examination Survey from 2011 to 2014. Read More

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Diagnosis of central serous chorioretinopathy by deep learning analysis of en face images of choroidal vasculature: A pilot study.

PLoS One 2021 18;16(6):e0244469. Epub 2021 Jun 18.

Department of Ophthalmology, Tokyo Women's Medical University, Shinjuku, Tokyo, Japan.

Purpose: To diagnose central serous chorioretinopathy (CSC) by deep learning (DL) analyses of en face images of the choroidal vasculature obtained by optical coherence tomography (OCT) and to analyze the regions of interest for the DL from heatmaps.

Methods: One-hundred eyes were studied; 53 eyes with CSC and 47 normal eyes. Volume scans of 12×12 mm square were obtained at the same time as the OCT angiographic (OCTA) scans (Plex Elite 9000 Swept-Source OCT®, Zeiss). Read More

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