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Matthew A Psioda, Joseph G Ibrahim
We consider the problem of Bayesian sample size determination for a clinical trial in the presence of historical data that inform the treatment effect. Our broadly applicable, simulation-based methodology provides a framework for calibrating the informativeness of a prior while simultaneously identifying the minimum sample size required for a new trial such that the overall design has appropriate power to detect a non-null treatment effect and reasonable type I error control. We develop a comprehensive strategy for eliciting null and alternative sampling prior distributions which are used to define Bayesian generalizations of the traditional notions of type I error control and power...
March 14, 2018: Biostatistics
Samuel Mesihää, Ilpo Rasanen, Ilkka Ojanperä
Gas chromatography (GC) hyphenated with nitrogen chemiluminescence detection (NCD) and quadrupole time-of-flight mass spectrometry (QTOFMS) was applied for the first time to the quantitative analysis of new psychoactive substances (NPS) in urine, based on the N-equimolar response of NCD. A method was developed and validated to estimate the concentrations of three metabolites of the common stimulant NPS α-pyrrolidinovalerophenone (α-PVP) in spiked urine samples, simulating an analysis having no authentic reference standards for the metabolites and using the parent drug instead for quantitative calibration...
February 27, 2018: Forensic Science International
A Abellán-Llobregat, C González-Gaitán, L Vidal, A Canals, E Morallón
A new portable electrochemical sensor based on 4-aminobenzoic acid-modified herringbone carbon nanotubes (hCNTs-4ABA/Au-IDA) has been developed for the simultaneous determination of ascorbic acid (AA) and uric acid (UA) in physiological fluids. AA and UA were quantified by chronoamperometry at 0.1 and 0.32 V, respectively, in phosphate buffer solution (PBS 0.25 M, pH 7.0). Significant results were obtained for the separate quantification of AA and UA, with a limit of detection (LOD) of 0.65 μM for both analytes, and sensitivities of (9...
February 23, 2018: Biosensors & Bioelectronics
Christopher Nicolai Roterman, Won-Kyung Lee, Xinming Liu, Rongcheng Lin, Xinzheng Li, Yong-Jin Won
The recent discovery of two new species of kiwaid squat lobsters on hydrothermal vents in the Pacific Ocean and in the Pacific sector of the Southern Ocean has prompted a re-analysis of Kiwaid biogeographical history. Using a larger alignment with more fossil calibrated nodes than previously, we consider the precise relationship between Kiwaidae, Chirostylidae and Eumunididae within Chirostyloidea (Decapoda: Anomura) to be still unresolved at present. Additionally, the placement of both new species within a new "Bristly" clade along with the seep-associated Kiwa puravida is most parsimoniously interpreted as supporting a vent origin for the family, rather than a seep-to-vent progression...
2018: PloS One
Estefania Munoz Diaz, Susanna Kaiser, Dina Bousdar Ahmed
Shoe-mounted inertial sensors are widespread deployed in satellite-denied scenarios because of the possibility to re-calibrate stepwise the estimated position. These re-calibrations, known as zero-velocity corrections, prevent an accumulated positioning error growth over time caused by the noise of current medium- and low-cost sensors. However, the error accumulated over time in the height estimation is still an issue under study. The objective of this article is to propose a height correction that is based on the dynamics of the foot...
March 16, 2018: Sensors
Bismil Ali Ali, Rolf Lefering, Mariano Fortún Moral, Tomás Belzunegui Otano
OBJECTIVES: To validate the Mortality Prediction Model of Navarre (MPMN) to predict death after severe trauma and compare it to the Revised Injury Severity Classification Score II (RISCII). MATERIAL AND METHODS: Retrospective analysis of a cohort of severe trauma patients (New Injury Severity Score >15) who were attended by emergency services in the Spanish autonomous community of Navarre between 2013 and 2015. The outcome variable was 30-day all-cause mortality...
2018: Emergencias: Revista de la Sociedad Española de Medicina de Emergencias
Susana García-Gutiérrez, José M Quintana López, Ane Antón-Ladislao, María Soledad Gallardo Rebollal, Irene Rilo Miranda, Miren Morillas Bueno, Nekane Murga Eizagaetxebarria, Ricardo Palenzuela Arocena, Esther Pulido, Irantzu Barrio Beraza, Urko Aguirre Larracoechea, Inmaculada Arostegui
OBJECTIVES: To validate the EAHFE-3D scale, based on the Acute Heart Failure in Emergency Departments registry, in a cohort of patients attended for acute heart failure. MATERIAL AND METHODS: Study of a multipurpose cohort of patients with acute heart failure in 3 hospitals in the Basque Country between 2011 and 2013. We extracted age, baseline New York Heart Association functional class, systolic blood pressure, baseline arterial oxygen saturation, sodium level in blood, and emergency department treatments (noninvasive mechanical ventilation, use of inotropic agents and vasopressors) in order to calculate each patient's EAHFE-3D score...
2018: Emergencias: Revista de la Sociedad Española de Medicina de Emergencias
Jejoong Yoo, Aleksei Aksimentiev
In contrast to ordinary polymers, the vast majority of biological macromolecules adopt highly ordered three-dimensional structures that define their functions. The key to folding of a biopolymer into a unique 3D structure or to an assembly of several biopolymers into a functional unit is a delicate balance between the attractive and repulsive forces that also makes such self-assembly reversible under physiological conditions. The all-atom molecular dynamics (MD) method has emerged as a powerful tool for studies of individual biomolecules and their functional assemblies, encompassing systems of ever increasing complexity...
March 16, 2018: Physical Chemistry Chemical Physics: PCCP
Galia Spectre, Fariborz Mobarrez, Ragnhild Stålesen, Claes-Göran Östenson, David Varon, Håkan Wallen, Paul Hjemdahl
Diabetes mellitus (DM) is associated with prothrombotic alterations, and postprandial hyperglycemia is an independent risk factor for cardiovascular complications. We therefore investigated whether a standardized mixed meal alters circulating microparticles (MPs) and their procoagulant activity in DM patients. Patients with DM type 1 (T1DM, n = 11) and type 2 (T2DM; n = 9) were studied before and 90 min after a standardized meal (without premeal insulin). MPs in plasma derived from platelets (PMPs), endothelial cells (EMPs), or monocytes (MMPs) were measured by flow cytometry...
March 16, 2018: Platelets
S T Ayrton, X Chen, R M Bain, C J Pulliam, M Achmatowicz, T G Flick, D Ren, R G Cooks
Proof of concept evidence is presented for a new method for the determination of isoaspartate, an important post-translational modification. Chemical derivatization is performed using common reagents for the modification of carboxylic acids and shown to yield suitable diagnostic information with regard to isomerization at the aspartate residue. The diagnostic gas phase chemistry is probed by collision-induced dissociation mass spectrometry, on the timescale of the MS experiment and semi-quantitative calibration of the percentage of isoaspartate in a peptide sample is demonstrated...
March 15, 2018: Journal of the American Society for Mass Spectrometry
Christopher B Forrest, Lisa J Meltzer, Carole L Marcus, Anna de la Motte, Amy Kratchman, Daniel J Buysse, Paul A Pilkonis, Brandon D Becker, Katherine B Bevans
Study Objectives: To develop and evaluate the measurement properties of child-report and parent-proxy versions of the PROMIS ® Pediatric Sleep Disturbance and Sleep-Related Impairment item banks. Methods: A national sample of 1,104 children (8-17 years-old) and 1,477 parents of children 5-17 years-old was recruited from an internet panel to evaluate the psychometric properties of 43 sleep health items. A convenience sample of children and parents recruited from a pediatric sleep clinic was obtained to provide evidence of the measures' validity; polysomnography data were collected from a subgroup of these children...
March 13, 2018: Sleep
Yanqi Huang, Lan He, Di Dong, Caiyun Yang, Cuishan Liang, Xin Chen, Zelan Ma, Xiaomei Huang, Su Yao, Changhong Liang, Jie Tian, Zaiyi Liu
Objective: To develop and validate a radiomics prediction model for individualized prediction of perineural invasion (PNI) in colorectal cancer (CRC). Methods: After computed tomography (CT) radiomics features extraction, a radiomics signature was constructed in derivation cohort (346 CRC patients). A prediction model was developed to integrate the radiomics signature and clinical candidate predictors [age, sex, tumor location, and carcinoembryonic antigen (CEA) level]...
February 2018: Chinese Journal of Cancer Research, Chung-kuo Yen Cheng Yen Chiu
Alan L Deino, Anna K Behrensmeyer, Alison S Brooks, John E Yellen, Warren D Sharp, Richard Potts
The origin of the Middle Stone Age (MSA) denotes the transition from a highly persistent mode of stone toolmaking, the Acheulean, to a period of increasing technological innovation and cultural indicators associated with the evolution of Homo sapiens Here we use40 Ar/39 Ar and U-series dating to calibrate the chronology of Acheulean- and early MSA-rich sedimentary deposits in the Olorgesailie Basin, South Kenya Rift. We establish the age of late Acheulean tool assemblages from 615 to 499 ka, after which a large technological and faunal transition occurred, with definitive MSA lacking Acheulean elements beginning most likely by ~320 ka, but at least by 305 ka...
March 15, 2018: Science
James R Thunes, Julie A Phillippi, Thomas G Gleason, David A Vorp, Spandan Maiti
High lethality of aortic dissection necessitates accurate predictive metrics for dissection risk assessment. The not infrequent incidence of dissection at aortic diameters <5.5 cm, the current threshold guideline for surgical intervention (Nishimura et al., 2014), indicates an unmet need for improved evidence-based risk stratification metrics. Meeting this need requires a fundamental understanding of the structural mechanisms responsible for dissection evolution within the vessel wall. We present a structural model of the repeating lamellar structure of the aortic media comprised of elastic lamellae and collagen fiber networks, the primary load-bearing components of the vessel wall...
February 8, 2018: Journal of Biomechanics
C J Gauthier, A P Fan
The BOLD contrast mechanism has a complex relationship with functional brain activity, oxygen metabolism, and neurovascular factors. Accurate interpretation of the BOLD signal for neuroscience and clinical applications necessitates a clear understanding of the sources of BOLD contrast and its relationship to underlying physiology. This review describes the physiological components that contribute to the BOLD signal and the steady-state calibrated BOLD models that enable quantification of functional changes with a separate challenge paradigm...
March 12, 2018: NeuroImage
Long Chen, Wen Tang, Nigel W John, Tao Ruan Wan, Jian Jun Zhang
BACKGROUND AND OBJECTIVE: While Minimally Invasive Surgery (MIS) offers considerable benefits to patients, it also imposes big challenges on a surgeon's performance due to well-known issues and restrictions associated with the field of view (FOV), hand-eye misalignment and disorientation, as well as the lack of stereoscopic depth perception in monocular endoscopy. Augmented Reality (AR) technology can help to overcome these limitations by augmenting the real scene with annotations, labels, tumour measurements or even a 3D reconstruction of anatomy structures at the target surgical locations...
May 2018: Computer Methods and Programs in Biomedicine
E S Von Zuben, A G Oliveira, M Chorilli, M V Scarpa
A reversed-phase liquid chromatography (RP-LC) method was successfully developed and validated for the determination of methotrexate in nanostructured liquid crystalline systems composed by polyether functional siloxane and silicone polyether copolymer. The LC method was performed on RP C18-ODS column, Agilent Zorbax® (4.6 x 250 mm, 5 μm), maintained at room temperature, with a mobile phase constituted by a mixture of 50 mM ammonium acetate buffer (pH 6.0) and methanol (77:23,v/v) with a flow rate of 1.0 mL/min, using ultraviolet detection at 313 nm...
March 5, 2018: Die Pharmazie
Hua Gao, Xiaolong Sun, Wen Li, Qiong Gao, Jing Zhang, Yi Zhang, Yue Ma, Xiai Yang, Xiaogang Kang, Wen Jiang
Objective Stroke due to atrial fibrillation (AF) is common and frequently devastating. However, there is no specific tool to accurately estimate the risk of mortality. This study aims to develop and validate a comprehensive risk score for predicting 30-day mortality in the patients with AF-related stroke. Methods A retrospective multi-center clinical study was performed based on the data from the project of secondary prevention of stroke in patients with nonvalvular AF in Shaanxi province, China. A total of 1077 consecutive patients were randomly classified into derivation (66...
March 16, 2018: Neurological Research
Henrik Staer-Jensen, Kjetil Sunde, Espen Rostrup Nakstad, Jan Eritsland, Geir Øystein Andersen
OBJECTIVES: Haemodynamic monitoring during post arrest care is important to optimise treatment. We compared stroke volume measured by minimally-invasive monitoring devices with or without thermodilution calibration, and transthoracic echocardiography (TTE), and hypothesised that thermodilution calibration would give stroke volume index (SVI) more in agreement with TTE during targeted temperature management (TTM). DESIGN: Comatose out-of-hospital cardiac arrest survivors receiving TTM (33 °C for 24 hrs) underwent haemodynamic monitoring with arterial pulse contour analyses with (PiCCO2®) and without (FloTrac® /Vigileo® monitor® ) transpulmonary thermodilution calibration...
March 16, 2018: Scandinavian Cardiovascular Journal: SCJ
Evelina Cardoso, Thomas Mercier, Anna Dorothea Wagner, Krisztian Homicsko, Olivier Michielin, Kim Ellefsen-Lavoie, Laurène Cagnon, Manuel Diezi, Thierry Buclin, Nicolas Widmer, Chantal Csajka, Laurent Decosterd
A sensitive and selective method of high performance liquid chromatography (HPLC) coupled to tandem mass spectrometry (MS/MS) has been developed for the simultaneous quantification of six anticancer protein kinase inhibitors (PKIs), dabrafenib, trametinib, vemurafenib, cobimetinib, pazopanib, regorafenib, and two active metabolites (regorafenib-M2 and regorafenib-M5) in human plasma. Plasma protein precipitation with methanol enables the sample extraction of 100 μL aliquot of plasma. Analytes are detected by electrospray triple-stage quadrupole mass spectrometry and quantified using the calibration curves with stable isotope-labeled internal standards...
February 8, 2018: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
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