31,372 results match your criteria initial step


IMU-based knee flexion, abduction and internal rotation estimation during drop landing and cutting tasks.

J Biomech 2021 Jun 13;124:110549. Epub 2021 Jun 13.

School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai, China. Electronic address:

Anterior cruciate ligament (ACL) injury is a common and severe knee injury in sports. Knee flexion, abduction and internal rotation angles are considered crucial biomechanical indicators of the ACL injury risk but currently are computed in a laboratory with an optical motion capture. This paper introduces an inertial measurement unit (IMU) based algorithm for knee flexion, abduction and internal rotation estimation during ACL injury risk assessment tests, including drop landing and cutting tasks. Read More

View Article and Full-Text PDF

Evolution of Clinical Skills Assessment in the USMLE: Looking to the Future After Step 2 CS Discontinuation.

Acad Med 2021 Jun 22. Epub 2021 Jun 22.

P.J. Katsufrakis is president and CEO, NBME, Philadelphia, Pennsylvania; ORCID: https://orcid.org/0000-0001-9077-9190. H.J. Chaudhry is president and CEO, Federation of State Medical Boards, Euless, Texas; ORCID: https://orcid.org/0000-0003-3356-1106.

The COVID-19 pandemic interrupted administration of the United States Medical Licensing Examination (USMLE) Step 2 Clinical Skills (CS) exam in March 2020 due to public health concerns. As the scope and magnitude of the pandemic became clearer, the initial plans by the USMLE program's sponsoring organizations (NBME and Federation of State Medical Boards) to resume Step 2 CS in the short-term shifted to long-range plans to relaunch an exam that could harness technology and reduce infection risk. Insights about ongoing changes in undergraduate and graduate medical education and practice environments, coupled with challenges in delivering a transformed examination during a pandemic, led to the January 2021 decision to permanently discontinue Step 2 CS. Read More

View Article and Full-Text PDF

Probing Monomer and Dimer Adsorption Trends in the MFI Framework.

J Phys Chem B 2021 Jun 24. Epub 2021 Jun 24.

Department of Chemical and Biological Engineering, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States.

Porous aluminosilicates such as zeolites are ubiquitous catalysts for the production of high-value and industrially relevant commodity chemicals, including the conversion of hydrocarbons, amines, alcohols, and others. Bimolecular reactions are an important subclass of reactions that can occur on Brønsted acid sites of a zeolite catalyst. Kinetic modeling of these systems at the process scale requires the interaction energetics of reactants and the active sites to be described accurately. Read More

View Article and Full-Text PDF

Interplay between spin crossover and proton migration along short strong hydrogen bonds.

Chem Sci 2020 Nov 16;12(3):1038-1053. Epub 2020 Nov 16.

Instituto de Ciencia Molecular, Universitat de València P. O. Box 22085 46071 València Spain

The iron(ii) salt [Fe(bpp)](isonicNO)·HisonicNO·5HO () (bpp = 2,6-bis(pyrazol-3-yl)pyridine; isonicNO = isonicotinate N-oxide anion) undergoes a partial spin crossover (SCO) with symmetry breaking at = 167 K to a mixed-spin phase (50% high-spin (HS), 50% low-spin (LS)) that is metastable below = 116 K. Annealing the compound at lower temperatures results in a 100% LS phase that differs from the initial HS phase in the formation of a hydrogen bond (HB) between two water molecules (O4W and O5W) of crystallisation. Neutron crystallography experiments have also evidenced a proton displacement inside a short strong hydrogen bond (SSHB) between two isonicNO anions. Read More

View Article and Full-Text PDF
November 2020

Single-molecule imaging and kinetic analysis of intermolecular polyoxometalate reactions.

Chem Sci 2021 Apr 26;12(21):7377-7387. Epub 2021 Apr 26.

School of Chemistry, University of Nottingham University Park Nottingham NG7 2RD UK

We induce and study reactions of polyoxometalate (POM) molecules, [PWO] (Keggin) and [PWO] (Wells-Dawson), at the single-molecule level. Several identical carbon nanotubes aligned side by side within a bundle provided a platform for spatiotemporally resolved imaging of 100 molecules encapsulated within the nanotubes by transmission electron microscopy (TEM). Due to the entrapment of POM molecules their proximity to one another is effectively controlled, limiting molecular motion in two dimensions but leaving the third dimension available for intermolecular reactions between pairs of neighbouring molecules. Read More

View Article and Full-Text PDF

Modeling host-associating microbes under selection.

ISME J 2021 Jun 22. Epub 2021 Jun 22.

Max-Planck-Institute for Evolutionary Biology, Ploen, Germany.

The concept of fitness is often reduced to a single component, such as the replication rate in a given habitat. For species with multi-step life cycles, this can be an unjustified oversimplification, as every step of the life cycle can contribute to the overall reproductive success in a specific way. In particular, this applies to microbes that spend part of their life cycles associated to a host. Read More

View Article and Full-Text PDF

Native mass spectrometry analyses of chaperonin complex TRiC/CCT reveal subunit N-terminal processing and re-association patterns.

Sci Rep 2021 Jun 22;11(1):13084. Epub 2021 Jun 22.

Department of Biology, Stanford University, Stanford, CA, USA.

The eukaryotic chaperonin TRiC/CCT is a large ATP-dependent complex essential for cellular protein folding. Its subunit arrangement into two stacked eight-membered hetero-oligomeric rings is conserved from yeast to man. A recent breakthrough enables production of functional human TRiC (hTRiC) from insect cells. Read More

View Article and Full-Text PDF

Chemical insights into the atmospheric oxidation of thiophene by hydroperoxyl radical.

Sci Rep 2021 Jun 22;11(1):13049. Epub 2021 Jun 22.

Department of Chemistry, University of Zanjan, PO Box 38791-45371, Zanjan, Iran.

The reaction mechanisms and kinetics of thiophene oxidation reactions initiated by hydroperoxyl radical, and decomposition of the related intermediates and complexes, have been considered herein by using high-level DFT and ab initio calculations. The main energetic parameters of all stationary points of the suggested potential energy surfaces have been computed at the BD(T) and CCSD(T) methods, based on the geometries optimized at the B3LYP/6-311 + g(d,p) level of theory. Rate constants of bimolecular reactions (high-pressure limit rate constants) at temperatures from 300 to 3000 K for the first steps of the title reaction have been obtained through the conventional transition state theory (TST), while the pressure dependent rate constants and the rate constants of the second and other steps have been calculated employing the Rice-Ramsperger-Kassel-Marcus/Master equation (RRKM/ME). Read More

View Article and Full-Text PDF

Mechanism and structure based design of inhibitors of AMP and adenosine deaminase.

Bioorg Med Chem 2021 Jun 10;43:116272. Epub 2021 Jun 10.

Department of Biomedical Sciences, Oakland University, William Beaumont School of Medicine, Rochester, MI 48309, USA.

Inhibitors of the enzyme adenosine monophosphate deaminase (AMPD) show interesting levels of herbicidal activity. An enzyme mechanism-based approach has been used to design new inhibitors of AMPD starting from nebularine (6) and resulting in the synthesis of 2-deoxy isonebularine (16). This compound is a potent inhibitor of the related enzyme adenosine deaminase (ADA; IC 16 nM), binding over 5000 times more strongly than nebularine. Read More

View Article and Full-Text PDF

Highly Dense and Stable p-Type Thin-Film Transistor Based on Atomic Layer Deposition SnO Fabricated by Two-Step Crystallization.

ACS Appl Mater Interfaces 2021 Jun 22. Epub 2021 Jun 22.

Division of Materials Science and Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 04763, Republic of Korea.

Over the past several decades, tin monoxide (SnO) has been studied extensively as a p-type thin film transistor (TFT). However, its TFT performance is still insufficient for practical use. Many studies suggested that the instability of the valence state of Sn (Sn/Sn) is a critical reason for the poor performance such as limited mobility and low on/off ratio. Read More

View Article and Full-Text PDF

Quantification of US Food and Drug Administration Premarket Approval Statements for High-Risk Medical Devices With Pediatric Age Indications.

JAMA Netw Open 2021 Jun 1;4(6):e2112562. Epub 2021 Jun 1.

Hasso Plattner Institute for Digital Health at Mount Sinai, Icahn School of Medicine at Mount Sinai, New York, New York.

Importance: Medical device companies submit premarket approval (PMA) statements to the US Food and Drug Administration (FDA) for approval of the highest-risk class of devices. Devices indicated for the pediatric population that use the PMA pathway have not been well characterized or analyzed.

Objective: To identify and characterize high-risk devices with pediatric age indications derived from PMA statements. Read More

View Article and Full-Text PDF

Engaging Sexual and Gender Minority Youth in HIV Interventions Through Gay Dating Apps: Recruitment Protocol.

JMIR Res Protoc 2021 06 22;10(6):e28864. Epub 2021 Jun 22.

Department of Pediatrics, School of Medicine, Tulane University, New Orleans, LA, United States.

Background: HIV continues to disproportionately impact sexual and gender minority youth (SGMY) in the United States. Public health efforts have increasingly focused on developing efficacious interventions to curb the spread of HIV among SGMY and help those living with HIV achieve and sustain viral suppression. However, recruiting and engaging SGMY in prevention and care interventions is challenging. Read More

View Article and Full-Text PDF

Physics-Based Protein Structure Refinement in the Era of Artificial Intelligence.

Proteins 2021 Jun 22. Epub 2021 Jun 22.

Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, USA.

Protein structure refinement is the last step in protein structure prediction pipelines. Physics-based refinement via molecular dynamics (MD) simulations has made significant progress during recent years. During CASP14, we tested a new refinement protocol based on an improved sampling strategy via MD simulations. Read More

View Article and Full-Text PDF

Interspecies signalling affects virulence related morphological characteristics of Streptococcus pyogenes M3.

FEMS Microbiol Lett 2021 Jun 22. Epub 2021 Jun 22.

Symbiosis School of Biological Sciences, Symbiosis International (Deemed University), Symbiosis Knowledge Village, Lavale Pune 412115, Maharashtra, India.

Streptococcus pyogenes is a gram-positive human-specific pathogen that asymptomatically colonises the human respiratory tract. The factors affecting the colonization to the host is not clearly understood. Adherence of the pathogen to host epithelial cell is the initial step for a successful colonisation process. Read More

View Article and Full-Text PDF

Msi1 promotes breast cancer metastasis by regulating invadopodia-mediated extracellular matrix degradation via the Timp3-Mmp9 pathway.

Oncogene 2021 Jun 21. Epub 2021 Jun 21.

Key Laboratory of Precision Nutrition and Food Quality, Ministry of Education, Department of Nutrition and Health, College of Biological Sciences, China Agricultural University, Beijing, China.

Metastasis is the main cause of death in breast cancer patients. The initial step of metastasis is invadopodia-mediated extracellular matrix (ECM) degradation, which enables local breast tumor cells to invade surrounding tissues. However, the molecular mechanism underlying invadopodia-mediated metastasis remains largely unknown. Read More

View Article and Full-Text PDF

One-step preparation of antimicrobial silicone materials based on PDMS and salicylic acid: insights from spatially and temporally resolved techniques.

NPJ Biofilms Microbiomes 2021 Jun 21;7(1):51. Epub 2021 Jun 21.

Open Innovation Hub for Antimicrobial Surfaces, Department of Chemistry, University of Liverpool & National Biofilm Innovation Centre, Liverpool, UK.

In this work, we introduce a one-step strategy that is suitable for continuous flow manufacturing of antimicrobial PDMS materials. The process is based on the intrinsic capacity of PDMS to react to certain organic solvents, which enables the incorporation of antimicrobial actives such as salicylic acid (SA), which has been approved for use in humans within pharmaceutical products. By combining different spectroscopic and imaging techniques, we show that the surface properties of PDMS remain unaffected while high doses of the SA are loaded inside the PDMS matrix. Read More

View Article and Full-Text PDF

Treadmill versus overground gait training in patients with lower limb burn injury: A matched control study.

Burns 2021 Apr 24. Epub 2021 Apr 24.

Hacettepe University, Faculty of Physical Therapy and Rehabilitation, Ankara, Turkey.

Introduction: Gait impairment is commonly seen in patients with a lower limb burn injury (LLBI). Therefore, the aim of this study was to investigate the effects of two different gait training modes on gait symmetry, functional mobility and kinesiophobia in patients with LLBI.

Methods: This matched control study was conducted between January 2017 and August 2018. Read More

View Article and Full-Text PDF

Paired analysis of tumor mutation burden calculated by targeted deep sequencing panel and whole exome sequencing in Non-Small Cell Lung Cancer.

BMB Rep 2021 Jun 22. Epub 2021 Jun 22.

Division of Hematology-Oncology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.

Background: Owing to rapid advancements in NGS (next generation sequencing), genomic alteration is now considered an essential predictive biomarkers that impact the treatment decision in many cases of cancer. Among the various predictive biomarkers, tumor mutation burden (TMB) was identified by NGS and was considered to be useful in predicting a clinical response in cancer cases treated by immunotherapy. In this study, we directly compared the lab-developed-test (LDT) results by target sequencing panel, K-MASTER panel v3. Read More

View Article and Full-Text PDF

One-shot phase retrieval method for interferometry using a hypercolumns convolutional neural network.

Opt Express 2021 May;29(11):16406-16421

In three dimensional profilometry, phase retrieval technique plays a key role in signal processing stage. Fringe images need to be transformed into phase information to obtain the measurement result. In this paper, a new phase retrieval method based on deep learning technique is proposed for interferometry. Read More

View Article and Full-Text PDF

Construction of Spiro-γ-butyrolactone Core via Cascade Photochemical Reaction of 3-Hydroxypyran-4-one Derivatives.

Org Lett 2021 Jun 21. Epub 2021 Jun 21.

N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Science, Leninsky Pr., 47, Moscow 119991, Russian Federation.

We elaborate a novel one-step photochemical method for the synthesis of spiro-γ-butyrolactone derivatives from 3-hydroxypyran-4-ones. The suggested approach is based on a cascade process including initial photoinduced contraction of 4-pyranone ring followed by intramolecular cyclization leading to the final spiro system. A distinctive feature of the proposed method is intramolecular trapping of unstable α-hydroxydiketone intermediate formed as a result of a photochemical reaction. Read More

View Article and Full-Text PDF

Plasma Levels of Amyloid-β Peptides and Tau Protein in Mexican Patients with Alzheimer's Disease.

J Alzheimers Dis 2021 Jun 11. Epub 2021 Jun 11.

Unidad de Investigación Médica en Farmacología, Hospital de Especialidades Bernardo Sepúlveda, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Mexico City, Mexico.

Background: Alzheimer's disease (AD) causes memory deficit and alterations in other cognitive functions, mainly in adults over 60 years of age. As the diagnosis confirmation is performed by a postmortem neuropathological examination of the brain, this disease can be confused with other types of dementia at early stages. About 860,000 Mexicans are affected by dementia, most of them with insufficient access to adequate comprehensive health care services. Read More

View Article and Full-Text PDF

Harvesting Cool Daylight in Hybrid Organic-Inorganic Halides Microtubules through the Reservation of Pressure-Induced Emission.

Adv Mater 2021 Jun 21:e2100323. Epub 2021 Jun 21.

State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun, 130012, China.

Pressure-induced emission (PIE) is extensively studied in halide perovskites or derivative hybrid halides. However, owing to the soft inorganic lattice of these materials, the intense emission is barely retained under ambient conditions, thus largely limiting their practical applications in optoelectronics at atmospheric pressure. Here, remarkably enhanced emission in microtubules of the 0D hybrid halide (C H N ) ZnBr ((4AMP) ZnBr ) is successfully achieved by means of pressure treatment at room temperature. Read More

View Article and Full-Text PDF

Adsorption of Hydrogen Sulfide at Low Temperatures Using an Industrial Molecular Sieve: An Experimental and Theoretical Study.

ACS Omega 2021 Jun 28;6(23):14774-14787. Epub 2021 May 28.

Laboratory of Alternative Fuels and Environmental Catalysis (LAFEC), Department of Chemical Engineering, University of Western Macedonia, GR-50100 Koila, Greece.

In the work presented herein, a joint experimental and theoretical approach has been carried out to obtain an insight into the desulfurization performance of an industrial molecular sieve (IMS), resembling a zeolitic structure with a morphology of cubic crystallites and a high surface area of 590 m g, with a view to removing HS from biogas. The impact of temperature, HS inlet concentration, gas matrix, and regeneration cycles on the desulfurization performance of the IMS was thoroughly probed. The adsorption equilibrium, sorption kinetics, and thermodynamics were also examined. Read More

View Article and Full-Text PDF

Simultaneous reduction and adsorption of arsenite anions by green synthesis of iron nanoparticles using pomegranate peel extract.

J Environ Health Sci Eng 2021 Jun 11;19(1):603-612. Epub 2021 Mar 11.

Environmental Science and Technology Research Center, Department of Environmental Health Engineering, School of Public Health, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.

Purpose: Arsenic is a toxic metalloid that is present in the environment as arsenate and arsenite anions. Exposure to arsenic anions caused skin problems, degenerative diseases, kidney, liver, and lung cancer. The synthesized iron nanoparticles (NPs) were examined as a green low-cost adsorbent for the removal of arsenite anions from aqueous solution via batch adsorption procedure. Read More

View Article and Full-Text PDF

Safety and feasibility of umbilical cord blood collection from preterm neonates after delayed cord clamping for the use of improving preterm complications.

Am J Transl Res 2021 15;13(5):4553-4560. Epub 2021 May 15.

The First Affiliated Hospital of Jinan University Guangzhou, China.

Background: Umbilical cord blood (UCB) is a new and convenient source of stem cells reported to be safe and effective in preventing and treating preterm complications. The initial processing step for this therapy involves cord blood collection and isolation of the mononuclear cell (MNC) layer. However, there is limited information regarding the feasibility and safety of cord blood collection in preterm infants, and whether cord blood cell quality and quantity are adequate for treating complications in preterm infants. Read More

View Article and Full-Text PDF

[Usefulness of Trapezoidal Cross-injection in Aortic 3D-CTA].

Authors:
Shun Muramatsu

Nihon Hoshasen Gijutsu Gakkai Zasshi 2021 ;77(6):564-571

Department of Radiology, Ohara General Hospital.

Purpose: This study aimed to compare the contrast effects of administration via the subclavian vein, the superior vena cava and right ventricular venous tract, and the aorta in three-dimensional computed tomography angiography (3D-CTA) using one-step injection and trapezoidal cross-injection.

Method: The subjects were 56 patients who underwent aortic 3D-CTA. In the one-step injection method, a 30-second injection of contrast medium was followed by saline injected at the same rate as the 30-ml contrast medium. Read More

View Article and Full-Text PDF

Prenatal Stress Exposure and Post-traumatic Stress Disorder Associated With Risk of Postpartum Alcohol Misuse Among Women Veterans.

Womens Health Issues 2021 Jun 18. Epub 2021 Jun 18.

Division of Research & Education, VA Central Western Massachusetts Healthcare System, Leeds, Massachusetts; Department of Psychiatry & Division of Addiction, University of Massachusetts Medical School, Worcester, Massachusetts; Department of Population and Quantitative Health Sciences, University of Massachusetts Medical School, Worcester, Massachusetts.

Objectives: Maternal alcohol misuse during the postpartum period is associated with negative maternal and infant outcomes. This study examined whether greater stress exposure in the year before the baby's birth and maternal post-traumatic stress disorder (PTSD) were associated with postpartum alcohol misuse among a sample of women veterans. Maternal PTSD was also examined as a moderator of the association between stress exposure and postpartum alcohol misuse. Read More

View Article and Full-Text PDF

COMPUTING ILL-POSED TIME-REVERSED 2D NAVIER-STOKES EQUATIONS, USING A STABILIZED EXPLICIT FINITE DIFFERENCE SCHEME MARCHING BACKWARD IN TIME.

Authors:
Alfred S Carasso

Inverse Probl Sci Eng 2020 ;28(7)

Applied and Computational Mathematics Division, National Institute of Standards and Technology, Gaithersburg, MD 20899.

This paper constructs an unconditionally stable explicit finite difference scheme, marching backward in time, that can solve an interesting but limited class of ill-posed, time-reversed, 2D incompressible Navier-Stokes initial value problems. Stability is achieved by applying a compensating smoothing operator at each time step to quench the instability. This leads to a distortion away from the true solution. Read More

View Article and Full-Text PDF
January 2020

Engineering triangular bimetallic metal-organic-frameworks derived hierarchical zinc-nickel-cobalt oxide nanosheet [email protected] graphene oxide-Ni foam as a binder-free electrode for ultra-high rate performance supercapacitors and methanol electro-oxidation.

J Colloid Interface Sci 2021 Jun 10;602:573-589. Epub 2021 Jun 10.

Carbon Composite Energy Nanomaterials Research Center, Woosuk University, Wanju, Chonbuk 55338, Republic of Korea; Department of Fire Disaster Prevention, Woosuk University, Wanju, Chonbuk 55338, Republic of Korea; Woosuk Institute of Smart Convergence Life Care (WSCLC), Woosuk University, Wanju, Chonbuk 55338, Republic of Korea. Electronic address:

The rigorous fabrication of electrode materials using upper-ranked porous precursor especially metal organic frameworks (MOFs) are challenging but appealing task to procure electrochemical energy storage and conversion system with altitudinous performance. Herein, we replenish the rational construction of atypical electrode of hollow Zn-Ni-Co-oxide (ZNCO) nanosheet arrays onto rGO garnished Ni foam (rGO/NF) via two step solution based method. Firstly, 2D Zn-Co-MOFs derived nanoleave arrays are prepared by co-precipitation method. Read More

View Article and Full-Text PDF

Indoleamine 2,3-dioxygenase 1 (IDO1): an up-to-date overview of an eclectic immunoregulatory enzyme.

FEBS J 2021 Jun 19. Epub 2021 Jun 19.

Departments of Medicine and Surgery, Italy.

Indoleamine 2,3-dioxygenase 1 (IDO1) catalyzes the initial rate-limiting step in the degradation of the essential amino acid tryptophan along the kynurenine pathway. When discovered more than 50 years ago, IDO1 was thought to be an effector molecule capable of mediating a survival strategy based on the deprivation of bacteria and tumor cells of the essential amino acid tryptophan. Since 1998, when tryptophan catabolism was discovered to be crucially involved in the maintenance of maternal T cell tolerance, IDO1 has become the focus of several laboratories around the world. Read More

View Article and Full-Text PDF