311 results match your criteria best sigmoidal

Predicting the Digestive Tract Development and Growth Performance of Goat Kids Using Sigmoidal Models.

Animals (Basel) 2021 Mar 10;11(3). Epub 2021 Mar 10.

Key Laboratory of Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.

The transition from monogastric to rumination stage is crucial in ruminants' growth to avoid stressors-weaning and neonatal mortalities. Poor growth of the digestive tract could adversely affect the performance of the animal. Modeling informative growth curves is of great importance for a better understanding of the effective development pattern, in order to optimize feeding management system, and to achieve more production efficiency. Read More

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Quantitative and Predictive Modelling of Lipid Oxidation in Mayonnaise.

Antioxidants (Basel) 2021 Feb 15;10(2). Epub 2021 Feb 15.

Laboratory of Food Chemistry, Wageningen University & Research, Bornse Weilanden 9, 6708 WG Wageningen, The Netherlands.

Food emulsions with high amounts of unsaturated fats, such as mayonnaise, are prone to lipid oxidation. In the food industry, typically accelerated shelf life tests are applied to assess the oxidative stability of different formulations. Here, the appearance of aldehydes at the so-called onset time, typically weeks, is considered a measure for oxidative stability of food emulsions, such as mayonnaise. Read More

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February 2021

Sample-size calculation for preclinical dose-response experiments using heterogeneous tumour models.

Radiother Oncol 2021 Mar 3;158:262-267. Epub 2021 Mar 3.

OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden - Rossendorf, Dresden, Germany; Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Germany; German Cancer Research Center (DKFZ), Heidelberg, Germany, and German Cancer Consortium (DKTK), partner site Dresden, Germany. Electronic address:

Background: In preclinical radio-oncological research, local tumour control is considered the most relevant endpoint as it reflects the inactivation of cancer stem cells. Preclinical tumour-control assays may compare dose-response curves between different radiotherapy strategies, e.g. Read More

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Study of patterned GaAsSbN nanowires using sigmoidal model.

Sci Rep 2021 Feb 25;11(1):4651. Epub 2021 Feb 25.

Nanoengineering, Joint School of Nanoscience and Nanoengineering, North Carolina A&T State University, Greensboro, NC, 27401, USA.

This study presents the first report on patterned nanowires (NWs) of dilute nitride GaAsSbN on p-Si (111) substrates by self-catalyzed plasma-assisted molecular beam epitaxy. Patterned NW array with GaAsSbN of Sb composition of 3% as a stem provided the best yield of vertical NWs. Large bandgap tuning of ~ 75 meV, as ascertained from 4 K photoluminescence (PL), over a pitch length variation of 200-1200 nm has been demonstrated. Read More

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February 2021

Pharmacodynamics of Posaconazole in Experimental Invasive Pulmonary Aspergillosis: Utility of Serum Galactomannan as a Dynamic Endpoint of Antifungal Efficacy.

Antimicrob Agents Chemother 2021 01 20;65(2). Epub 2021 Jan 20.

Infectious Disease Research Program, Center for Bone Marrow Transplantation and Department of Pediatric Hematology/Oncology, University Children's Hospital Münster, Münster, Germany

galactomannan antigenemia is an accepted tool for the diagnosis of invasive pulmonary aspergillosis (IPA) in neutropenic patients. Little is known, however, about the utility of this biomarker to assess the efficacy of antifungal therapies. The pharmacokinetics (PK) and pharmacodynamics (PD) of posaconazole in treatment and prophylaxis were investigated in the persistently neutropenic rabbit model of IPA at doses between 2 and 20 mg/kg per day. Read More

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January 2021

Auroral ionospheric plasma flow extraction using subsonic retarding potential analyzers.

Rev Sci Instrum 2020 Sep;91(9):094503

SRI International, Menlo Park, California 94025, USA.

Thermal ion retarding potential analyzers (RPAs) are used to measure in situ auroral ionospheric plasma parameters. This article analyzes data from a low-resource RPA in order to quantify the capability of the sensor. The RPA collects a sigmoidal current-voltage (I-V) curve, which depends on a non-linear combination of Maxwellian plasma parameters, so a forward-modeling procedure is used to match the best choice plasma parameters for each I-V curve. Read More

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September 2020

Development and Verification of a Body Weight-Directed Disease Trial Model for Glucose Homeostasis.

J Clin Pharmacol 2021 Feb 7;61(2):234-243. Epub 2020 Sep 7.

Center for Pharmacometrics and Systems Pharmacology, College of Pharmacy, University of Florida, Orlando, Florida, USA.

Weight loss has been associated with improvement in insulin sensitivity. It is consequently a cornerstone in the management of type 2 diabetes mellitus (T2DM). However, the strictly quantitative relationship between weight loss, insulin sensitivity, and clinically relevant glucose homeostasis biomarkers as well as changes therein as T2DM progresses is not yet fully understood. Read More

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February 2021

The growth of domestic goats and sheep: A meta study with Bertalanffy-Pütter models.

Vet Anim Sci 2020 Dec 1;10:100135. Epub 2020 Aug 1.

University of Natural Resources and Life Sciences (BOKU), Department of Integrative Biology and Biodiversity Research (DIBB), A-1180 Vienna, Austria.

Growth literature often uses the Brody, Gompertz, Verhulst, and von Bertalanffy models. Is there a rationale for the preference of these classical named models? The versatile five-parameter Bertalanffy-Pütter (BP) model generalizes these models. We revisited peer-reviewed publications from the years 1970-2019 that fitted growth models to together 122 mass-at-age data of sheep and goats from 19 countries and studied the best-fit BP-models using the least-squares method. Read More

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December 2020

A Time-to-Event Model Relating Integrated Craving to Risk of Smoking Relapse Across Different Nicotine Replacement Therapy Formulations.

Clin Pharmacol Ther 2021 Feb 19;109(2):416-423. Epub 2020 Sep 19.

Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden.

Smoking increases the risk of cancer and other diseases, causing an estimated 7 million deaths per year. Nicotine replacement therapy (NRT) reduces craving for smoking, therefore, increasing an individual's probability to remain abstinent. In this work, we for the first time quantitatively described the relationship between craving and smoking abstinence, using retrospectively collected data from 19 studies, including 3 NRT formulations (inhaler, mouth spray, and patch) and a combination of inhaler and patch. Read More

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February 2021

Sigmoidal VO on-kinetics: A new pattern in VO responses at the lower district of extreme exercise domain.

Respir Physiol Neurobiol 2020 10 26;281:103507. Epub 2020 Jul 26.

Coaching Education Department, Faculty of Sport Sciences, Ege University, 35050 Bornova, Izmir, Turkey. Electronic address:

The aim of the study was to analyse the VO on-kinetics belonging to the work rates within the lower district of extreme exercise domain. Maximal O utilisation and peak power outputs of eight well-trained cyclists were revealed by multisession trails. Critical threshold (CT) as the lower boundary of severe domain and aerobic limit power (ALP) as the upper boundary of severe domain were determined by multisession constant-load exercises. Read More

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October 2020

Weight gain responses of laying-type pullets to methionine plus cystine intake.

Animal 2020 Aug 22;14(S2):s294-s302. Epub 2020 May 22.

Department of Animal Sciences, Universidade Estadual Paulista, College of Agriculture and Veterinary Sciences, Via de Acesso Professor Paulo Donato Castelane s/n, 14883-900Jaboticabal, SP, Brazil.

Each individual in the population has a distinct maximum growth potential, and the growth curve may vary depending on the response to nutrient intake, growth phase and variability among animals. The present study aimed to (1) model weight gain (WG) response to methionine+cystine (Met+Cys) supply using different mathematical functions, (2) identify functions that better fit the growth responses of pullets, (3) determine the Met+Cys requirements that maximize WG based on breeding standards and (4) partition the Met+Cys requirements for WG and maintenance. Three trials were performed using 1448 laying-type pullets. Read More

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Population Pharmacokinetics of Sertraline in Healthy Subjects: a Model-Based Meta-analysis.

AAPS J 2020 05 19;22(4):73. Epub 2020 May 19.

Department of Experimental and Clinical Pharmacology, University of Minnesota, Minneapolis, Minnesota, USA.

Sertraline pharmacokinetics is poorly understood and highly variable due to large between-subject variability with inconsistent reports for oral bioavailability. The study objective was to characterize sertraline pharmacokinetics by developing and validating a sertraline population pharmacokinetic (PK) model in healthy subjects using published clinical PK data. We carried a systematic literature search in PubMed in October 2015 and identified 27 pharmacokinetic studies of sertraline conducted in healthy adult subjects and reported in the English language. Read More

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The Sigmoidal Pregnancy: A Rare Entity Complicated by an Inappropriate Medical Intervention.

Case Rep Obstet Gynecol 2020 1;2020:2725975. Epub 2020 Apr 1.

Faculty of Medicine of Damascus University, Damascus, Syria.

The abdominal ectopic pregnancy is very rare and accounts for less than 1% of all ectopic gestations. Due to the lack of clinical suspicion, many obstetricians confuse it with other diseases and manage it inappropriately. Here, we are reporting the case of a 41-year-old woman that was referred to our hospital because of severe vaginal bleeding caused by multiple uterine perforations during the dilatation and curettage. Read More

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Lipophilicity matters - A new look at experimental plant uptake data from literature.

Sci Total Environ 2020 Apr 13;713:136667. Epub 2020 Jan 13.

Bayer AG, Monheim, Germany.

Peer-reviewed Transpiration Stream Concentration Factor (TSCF) values were analysed to elucidate whether pH-induced changes in lipophilicity can explain some of the variability in reported TSCF and whether a potential relationship between lipophilicity and TSCF can be described by a simple mathematical model. The data set for this investigation combined TSCF values of 42 non-ionisable and ionisable compounds from hydroponic tests with intact plants and publicly available lipophilicity data for the tested compounds. The data set was not homogenous in terms of molecular weight of the tested compounds, plant species used for testing and experimental conditions, but a strong effect of one of these factors on variation in reported TSCF was not detected. Read More

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Bumpy and Smoother Pathways of Puberty Hormone Change: A Novel Way to Define Gonadal Hormone Trajectories in Adolescents.

J Endocr Soc 2020 Feb 29;4(2):bvz014. Epub 2019 Nov 29.

The University of Sydney, ANZAC Research Institute, Concord, NSW, Australia.

Context: The study of gonadal hormone effects on adolescent wellbeing has been limited by logistical challenges. Urine hormone profiling offers new opportunities to understand the health and behavioral implications of puberty hormones.

Objective: To characterize pubertal change in urinary testosterone and estradiol among male and female adolescents, respectively. Read More

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February 2020

Cranial anatomy of , a new species from the lower part of the Morrison Formation (Upper Jurassic) of Western North America.

PeerJ 2020 24;8:e7803. Epub 2020 Jan 24.

Natural History Museum of Utah, University of Utah, Salt Lake City, UT, USA.

is one of the best known theropod dinosaurs from the Jurassic and a crucial taxon in phylogenetic analyses. On the basis of an in-depth, firsthand study of the bulk of specimens housed in North American institutions, we describe here a new theropod dinosaur from the Upper Jurassic Morrison Formation of Western North America, sp. nov. Read More

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January 2020

Mechanistic Modeling of Mycobacterium tuberculosis Infection in Murine Models for Drug and Vaccine Efficacy Studies.

Antimicrob Agents Chemother 2020 02 21;64(3). Epub 2020 Feb 21.

University of California San Francisco, San Francisco, California, USA

Tuberculosis (TB) drug, regimen, and vaccine development rely heavily on preclinical animal experiments, and quantification of bacterial and immune response dynamics is essential for understanding drug and vaccine efficacy. A mechanism-based model was built to describe H37Rv infection over time in BALB/c and athymic nude mice, which consisted of bacterial replication, bacterial death, and adaptive immune effects. The adaptive immune effect was best described by a sigmoidal function on both bacterial load and incubation time. Read More

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February 2020

Human efflux transport of testosterone, epitestosterone and other androgen glucuronides.

J Steroid Biochem Mol Biol 2020 03 6;197:105518. Epub 2019 Nov 6.

Drug Research Program, Division of Pharmaceutical Chemistry and Technology, Faculty of Pharmacy, University of Helsinki, Finland.

Several drug-metabolizing enzymes are known to control androgen homeostasis in humans. UDP-glucuronosyltransferases convert androgens to glucuronide conjugates in the liver and intestine, which enables subsequent elimination of these conjugated androgens via urine. The most important androgen is testosterone, while others are the testosterone metabolites androsterone and etiocholanolone, and the testosterone precursor dehydroepiandrosterone. Read More

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The Effect of Interphase Gap on Neural Response of the Electrically Stimulated Cochlear Nerve in Children With Cochlear Nerve Deficiency and Children With Normal-Sized Cochlear Nerves.

Ear Hear 2020 Jul/Aug;41(4):918-934

Department of Auditory Implantation, Shandong Provincial ENT Hospital Affiliated to Shandong University, Jinan, Shandong Province, People's Republic of China.

Objectives: This study aimed to compare the effects of increasing the interphase gap (IPG) on the neural response of the electrically stimulated cochlear nerve (CN) between children with CN deficiency (CND) and children with normal-sized CNs.

Design: Study participants included 30 children with CND and 30 children with normal-sized CNs. All subjects were implanted with a Cochlear Nucleus device with the internal electrode array 24RE[CA] in the test ear. Read More

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November 2019

A continuum of stomatal responses to water deficits among 17 wine grape cultivars (Vitis vinifera).

Funct Plant Biol 2019 01;47(1):11-25

Department of Viticulture and Enology, University of California, Davis, CA 95616, USA.

Vitis vinifera L. cultivars have been previously classified as isohydric, near-isohydric, anisohydric or isohydrodynamic, depending on the study. To test the hypothesis that V. Read More

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January 2019

Oxidative stress in microbes after exposure to iron nanoparticles: analysis of aldehydes as oxidative damage products of lipids and proteins.

Environ Sci Pollut Res Int 2019 Nov 8;26(32):33670-33682. Epub 2019 Oct 8.

Institute of Microbiology of the Czech Academy of Sciences, Vídeňská 1083, CZ-142 20, Prague 4, Czech Republic.

Due to their enhanced reactivity, metal and metal-oxide nanoscale zero-valent iron (nZVI) nanomaterials have been introduced into remediation practice. To ensure that environmental applications of nanomaterials are safe, their possible toxic effects should be described. However, there is still a lack of suitable toxicity tests that address the specific mode of action of nanoparticles, especially for nZVI. Read More

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November 2019

Using Simulation to Define the Learning Curve for the Digital Cervical Examination.

Obstet Gynecol 2019 10;134 Suppl 1:1S-8S

Departments of Obstetrics and Gynecology and Biostatistics and Data Science, Wake Forest School of Medicine, Winston-Salem, North Carolina.

Introduction: To assess how skill in the digital cervical examination is acquired in medical students.

Methods: In a longitudinal study, medical students completed 200 simulated cervical examinations. We performed regressions of each student's cumulative accuracy using the linear, power, and sigmoidal models to determine best fit. Read More

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October 2019

Scanning Electron Microscopy in the Evaluation of Defects to the Ossicular Chain in the Course of Chronic Otitis Media.

Ear Nose Throat J 2019 Sep 29:145561319873913. Epub 2019 Sep 29.

Department of Otolaryngology, Head and Neck Surgery, Jagiellonian University Medical College, Kraków, Poland.

Objective: Chronic otitis media is a heterogeneous disorder. Chronic suppurative otitis media with cholesteatoma and, to a lesser extent, chronic otitis media with granulation lead to the destruction of bone structures within the middle ear. Bone loss may appear in the prominence of the horizontal semicircular canals and the bony canal of the facial nerve. Read More

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September 2019

Development of a non-linear growth model for predicting temporal evolution of Scenedesmus obliquus with varying irradiance.

Bioprocess Biosyst Eng 2019 Dec 20;42(12):2047-2054. Epub 2019 Aug 20.

Biofuels Division, CSIR-Indian Institute of Petroleum, Mohkampur, Dehradun, 248005, India.

In the present study, the effect of irradiance on growth performance of Scenedesmus obliquus was investigated, and various non-linear growth models were evaluated to predict its temporal evolution. This microalga was cultured in a LED-illuminated flat-panel gas-lift photobioreactor operated in batch mode at varying irradiance ranging from 50 to 200 µmol/m/s keeping all the other physico-chemical parameters constant. When growth data in terms of optical density were fitted in sigmoidal growth models, three non-linear models, namely, Richards model, Gompertz model, and logistic model, were found to be the best fit. Read More

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December 2019

Continuous infusion of physostigmine in patients with perioperative septic shock: A pharmacokinetic/pharmacodynamic study with population pharmacokinetic modeling.

Biomed Pharmacother 2019 Oct 6;118:109318. Epub 2019 Aug 6.

Pharmacy Department, Heidelberg University Hospital, Im Neuenheimer Feld 670, 69120 Heidelberg, Germany.

Background: In the context of the cholinergic anti-inflammatory pathway, the clinical trial Anticholium® per Se (EudraCT Number: 2012-001650-26, ClinicalTrials.gov NCT03013322) addressed the possibility of taking adjunctive physostigmine salicylate treatment in septic shock from bench to bedside. Pharmacokinetics (PK) are likely altered in critically ill patients; data on physostigmine PK and target concentrations are sparse, particularly for continuous infusion. Read More

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October 2019

A Semi-Mechanistic Population Pharmacokinetic/Pharmacodynamic Model of Bortezomib in Pediatric Patients with Relapsed/Refractory Acute Lymphoblastic Leukemia.

Clin Pharmacokinet 2020 02;59(2):207-216

Department of Pharmacy and Pharmacology, Netherlands Cancer Institute-Antoni van Leeuwenhoek, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands.

Introduction: The pharmacokinetics (PK) of the 20S proteasome inhibitor bortezomib are characterized by a large volume of distribution and a rapid decline in plasma concentrations within the first hour after administration. An increase in exposure was observed in the second week of treatment, which has previously been explained by extensive binding of bortezomib to proteasome in erythrocytes and peripheral tissues. We characterized the nonlinear population PK and pharmacodynamics (PD) of bortezomib in children with acute lymphoblastic leukemia. Read More

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February 2020

Mechanism study of photo-induced gold nanoparticles formation by Shewanella oneidensis MR-1.

Sci Rep 2019 05 20;9(1):7589. Epub 2019 May 20.

Department of Chemical Engineering, National Cheng Kung University, Tainan, 70101, ROC, Taiwan.

Shewanella oneidensis MR-1, a bioelectricity generating bacterium, is broadly used in bioremediation, microbial fuel cell and dissimilatory reduction and recovery of precious metals. Herein, we report for the first time that photo induction as a trigger to stimulate gold nanoparticles (Au@NPs) formation by MR-1, with wavelength and light intensity as two key variables. Results indicated that sigmoidal model is the best fit for Au@NPs formation at various wavelengths (with R > 0. Read More

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Comparison of pharmacokinetics and the exposure-response relationship of dapagliflozin between adolescent/young adult and adult patients with type 1 diabetes mellitus.

Br J Clin Pharmacol 2019 08 20;85(8):1820-1828. Epub 2019 Jun 20.

Quantitative Clinical Pharmacology, Early Clinical Development, IMED Biotech Unit, AstraZeneca, Gothenburg, Sweden.

Aims: To quantitatively compare pharmacokinetics (PK) and the exposure-response (ER) relationship of the sodium-glucose cotransporter-2 inhibitor, dapagliflozin, between adolescents/young adults and adults with type 1 diabetes mellitus (T1DM).

Methods: Data from 2 clinical studies for dapagliflozin were analysed using a non-linear mixed-effects approach. The PK and the relationship between dapagliflozin exposure and response (24-hour urinary glucose excretion) were characterized. Read More

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Arterial waveform morphomics during hemorrhagic shock.

Eur J Trauma Emerg Surg 2021 Apr 23;47(2):325-332. Epub 2019 Apr 23.

R Adams Cowley Shock Trauma Center, 22 S. Greene Street, Baltimore, MD, 21201, USA.

Purpose: The arterial pressure waveform is a composite of multiple interactions, and there may be more sensitive and specific features associated with hemorrhagic shock and intravascular volume depletion than systolic and/or diastolic blood pressure (BP) alone. The aim of this study was to characterize the arterial pressure waveform in differing grades of hemorrhage.

Methods: Ten anesthetized swine (70-90 kg) underwent a 40% controlled exponential hemorrhage. Read More

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Development of an HPLC-based guanosine monophosphate kinase assay and application to Plasmodium vivax guanylate kinase.

Anal Biochem 2019 06 31;575:63-69. Epub 2019 Mar 31.

Griffith Institute for Drug Discovery, Griffith University, Brisbane, Queensland, Australia. Electronic address:

The development of a high-performance liquid chromatography (HPLC)-based method, for guanosine monophosphate kinase activity assays, is presented. The method uses the intrinsic UV absorption (at 260 nm) of substrates and products of the enzymatic reaction (GMP, ATP, ADP and GDP) to unambiguously determine percent conversion of substrate into product. It uses a commercially available C18 column which can separate reaction samples by elution under isocratic conditions in 12 min per run. Read More

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