314 results match your criteria structures hamper

Catalytically active peptides affected by self-assembly and residues order.

Colloids Surf B Biointerfaces 2021 Apr 7;203:111751. Epub 2021 Apr 7.

Avram and Stella Goldstein-Goren Department of Biotechnology Engineering and Ilse Katz Institute for Nanoscience and Technology, Ben-Gurion University of the Negev POB 653, Beer-Sheva, 8410501, Israel. Electronic address:

Amphiphilic peptides that induce catalysis are interesting alternatives to natural enzymes thanks to robustness of their synthesis and the ability to induce certain types of conformations by specific motifs of amino acid sequences. Various studies aimed at mimicking the activity of serine proteases by designed peptides. Here we demonstrate that the order by which the catalytic triad residues are positioned along amphiphilic β-strands influences both assembly structures and catalytic activity. Read More

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Tailoring a complex perfect optical vortex array with multiple selective degrees of freedom.

Opt Express 2021 Mar;29(7):10811-10824

Optical vortex arrays (OVAs) have successfully aroused substantial interest from researchers for their promising prospects ranging from classical to quantum physics. Previous reported OVAs still show a lack of controllable dimensions which may hamper their applications. Taking an isolated perfect optical vortex (POV) as an array element, whose diameter is independent of its topological charge (TC), this paper proposes combined phase-only holograms to produce sophisticated POV arrays. Read More

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Strontium ranelate incorporated 3D porous sulfonated PEEK simulating MC3T3-E1 cell differentiation.

Regen Biomater 2021 Feb 28;8(1):rbaa043. Epub 2020 Nov 28.

Department of Pharmacy, Tongren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200336, China.

Polyetheretherketone (PEEK) has been used as an implant material because it has similar mechanical properties to natural bone. However, inferior osseointegration and bioinertness hamper the clinical application of PEEK. In this study, the surfaces of sulfonated three-dimensional (3D) PEEK porous structures were loaded with different concentrations of strontium ranelate, a compound commonly used in the treatment or prevention of osteoporosis by promoting bone formation and inhibiting bone resorption. Read More

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February 2021

Probing d- and l-Adrenaline Binding to β-Adrenoreceptor Peptide Motifs by Gas-Phase Photodissociation Cross-Linking and Ion Mobility Mass Spectrometry.

J Am Soc Mass Spectrom 2021 Apr 3;32(4):1041-1052. Epub 2021 Mar 3.

Department of Chemistry, University of Washington, Bagley Hall, Box 351700, Seattle, Washington 98195-1700, United States.

Diazirine-tagged d- and l-adrenaline derivatives formed abundant noncovalent gas-phase ion complexes with peptides -Ac-SSIVSFY-NH (peptide S) and -Ac-VYILLNWIGY-NH (peptide V) upon electrospray ionization. These peptide sequences represent the binding motifs in the β-adrenoreceptor. The structures of the gas-phase complexes were investigated by selective laser photodissociation of the diazirine chromophore at 354 nm, which resulted in a loss of N and formation of a transient carbene intermediate in the adrenaline ligand without causing its expulsion. Read More

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Barriers to Equitable Public Participation in Health-System Priority Setting Within the Context of Decentralization: The Case of Vulnerable Women in a Ugandan District.

Int J Health Policy Manag 2020 Dec 26. Epub 2020 Dec 26.

Department of Health Research Methods, Evidence, and Impact (HEI), McMaster Health Forum, Centre for Health Economics and Policy Analysis, McMaster University, Hamilton, ON, Canada.

Background: Decentralization of healthcare decision-making in Uganda led to the promotion of public participation. To facilitate this, participatory structures have been developed at sub-national levels. However, the degree to which the participation structures have contributed to improving the participation of vulnerable populations, specifically vulnerable women, remains unclear. Read More

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December 2020

Towards plant resistance to viruses using protein-only RNase P.

Nat Commun 2021 02 12;12(1):1007. Epub 2021 Feb 12.

Institut de biologie moléculaire des plantes, UPR2357 du CNRS, Université de Strasbourg, Strasbourg, France.

Plant viruses cause massive crop yield loss worldwide. Most plant viruses are RNA viruses, many of which contain a functional tRNA-like structure. RNase P has the enzymatic activity to catalyze the 5' maturation of precursor tRNAs. Read More

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February 2021

Early-phase pelvic bone SPECT: Simulation and comparison of several acquisition protocols to reduce bladder artifact and improve image quality.

Medicine (Baltimore) 2021 Jan;100(4):e24473

Nuclear Medicine Department.

Abstract: Tomoscintigraphic reconstruction in nuclear medicine assumes that the distribution of the tracer is unchanged in the volume of interest throughout the duration of the acquisition. This condition is however not met in early-phase bone scintigraphy and early-phase pelvic SPECT may display helical artifacts due to the filling of the bladder. Those artifacts may hamper proper interpretation of surrounding bone areas. Read More

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January 2021

Participatory health research with migrants: Opportunities, challenges, and way forwards.

Health Expect 2021 Feb 2. Epub 2021 Feb 2.

School of Medicine Limerick, Limerick, Ireland.

Context: Migration is one of the most politically pressing issues of the 21st century but migrant health remains an under-researched area. The International Collaboration for Participatory Health Research (ICPHR) working group on migration developed this position statement to address opportunities and challenges in relation to migrant health. It aims to contribute to a shift from a deficit model that sees migrants as passively affected by policies to their reconceptualization as citizens who are engaged in the co-creation of solutions. Read More

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February 2021

Defects and plasticity in ultrastrong supercrystalline nanocomposites.

Sci Adv 2021 Jan 8;7(2). Epub 2021 Jan 8.

Institute of Advanced Ceramics, Hamburg University of Technology, Hamburg, Germany.

Supercrystalline nanocomposites are nanoarchitected materials with a growing range of applications but unexplored in their structural behavior. They typically consist of organically functionalized inorganic nanoparticles arranged into periodic structures analogous to crystalline lattices, including superlattice imperfections induced by processing or mechanical loading. Although featuring a variety of promising functional properties, their lack of mechanical robustness and unknown deformation mechanisms hamper their implementation into devices. Read More

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January 2021

Cerebral Vessels: An Overview of Anatomy, Physiology, and Role in the Drainage of Fluids and Solutes.

Front Neurol 2020 13;11:611485. Epub 2021 Jan 13.

Faculty of Medicine, University of Southampton, Southampton, United Kingdom.

The cerebral vasculature is made up of highly specialized structures that assure constant brain perfusion necessary to meet the very high demand for oxygen and glucose by neurons and glial cells. A dense, redundant network of arteries is spread over the entire pial surface from which penetrating arteries dive into the cortex to reach the neurovascular units. Besides providing blood to the brain parenchyma, cerebral arteries are key in the drainage of interstitial fluid (ISF) and solutes such as amyloid-beta. Read More

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January 2021

Hydrogel-Based Bioinks for Cell Electrowriting of Well-Organized Living Structures with Micrometer-Scale Resolution.

Biomacromolecules 2021 Feb 7;22(2):855-866. Epub 2021 Jan 7.

Department of Orthopedics, University Medical Center Utrecht, Utrecht University, 3508 GA Utrecht, The Netherlands.

Bioprinting has become an important tool for fabricating regenerative implants and cell culture platforms. However, until today, extrusion-based bioprinting processes are limited to resolutions of hundreds of micrometers, which hamper the reproduction of intrinsic functions and morphologies of living tissues. This study describes novel hydrogel-based bioinks for cell electrowriting (CEW) of well-organized cell-laden fiber structures with diameters ranging from 5 to 40 μm. Read More

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February 2021

Mode-Matching Enhancement of Second-Harmonic Generation with Plasmonic Nanopatch Antennas.

ACS Photonics 2020 Dec 25;7(12):3333-3340. Epub 2020 Nov 25.

Center for Biomolecular Nanotechnologies, Istituto Italiano di Tecnologia, Via Barsanti 14, Arnesano 73010, Italy.

Plasmonic enhancement of nonlinear optical processes confront severe limitations arising from the strong dispersion of metal susceptibilities and small interaction volumes that hamper the realization of desirable phase-matching-like conditions. Maximizing nonlinear interactions in nanoscale systems require simultaneous excitation of resonant modes that spatially and constructively overlap at all wavelengths involved in the process. Here, we present a hybrid rectangular patch antenna design for optimal second-harmonic generation (SHG) that is characterized by a non-centrosymmetric dielectric/ferroelectric material at the plasmonic hot spot. Read More

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December 2020

Structural Diversity and Highly Specific Host-Pathogen Transcriptional Regulation of Defensin Genes Is Revealed in Tomato.

Int J Mol Sci 2020 Dec 9;21(24). Epub 2020 Dec 9.

Department of Viticulture, Vegetable Crops, Floriculture and Plant Protection, Institute of Olive Tree, Subtropical Crops and Viticulture, Hellenic Agricultural Organization ELGO-DIMITRA, Mesa Katsabas, 71307 Heraklion, Crete, Greece.

Defensins are small and rather ubiquitous cysteine-rich anti-microbial peptides. These proteins may act against pathogenic microorganisms either directly (by binding and disrupting membranes) or indirectly (as signaling molecules that participate in the organization of the cellular defense). Even though defensins are widespread across eukaryotes, still, extensive nucleotide and amino acid dissimilarities hamper the elucidation of their response to stimuli and mode of function. Read More

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December 2020

Experiences of barriers to trans-sectoral treatment of patients with severe mental illness. A qualitative study.

Int J Ment Health Syst 2020 Nov 30;14(1):87. Epub 2020 Nov 30.

Department of Public Health, Section of General Practice and Research Unit for General Practice, University of Copenhagen, Oester Farimagsgade 5, 1014, Copenhagen K, Denmark.

Background: Patients with severe mental illness (SMI) have shorter life expectancy than people without SMI, mainly due to overmortality from physical diseases. They are treated by professionals in three different health and social care sectors with sparse collaboration between them, hampering coherent treatment. Previous studies have shown difficulties involved in establishing such collaboration. Read More

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November 2020

Thermally Triggered, Cell-Specific Enzymatic Glyco-Editing: Regulation of Lectin Recognition and Immune Response on Target Cells.

ACS Appl Mater Interfaces 2020 Dec 25;12(49):54387-54398. Epub 2020 Nov 25.

State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China.

glyco-editing on the cell surface can endow cellular glycoforms with new structures and properties; however, the lack of cell specificity and dependence on cells' endogenous functions plague the revelation of cellular glycan recognition properties and hamper the application of glyco-editing in complicated authentic biosystems. Herein, we develop a thermally triggered, cell-specific glyco-editing method for regulation of lectin recognition on target live cells in both single- and cocultured settings. The method relies on the aptamer-mediated anchoring of microgel-encapsulated neuraminidase on target cells and subsequent thermally triggered enzyme release for localized sialic acid (Sia) trimming. Read More

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December 2020

Experience of physical activity described by patients with heart failure who have received individualized exercise advice: A qualitative study.

J Rehabil Med 2021 Jan 5;53(1):jrm00139. Epub 2021 Jan 5.

Department of Health, Medicine and Caring Sciences, Linkoping University, Norrköping, Sweden.

Objective: To describe the experience of physical activity in patients with heart failure who were randomized to a control group in which they received exercise advice and motivational support.

Design: A qualitative descriptive interview study, using qualitative content analysis.

Patients: Fifteen patients with heart failure. Read More

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January 2021

High-Frequency Application of Cationic Agents Containing Lubricant Eye Drops Causes Cumulative Corneal Toxicity in an Eye Irritation Test Model.

J Ocul Pharmacol Ther 2020 12 11;36(10):725-731. Epub 2020 Nov 11.

Aachen Centre of Technology Transfer in Ophthalmology e.V., An-Institute RWTH Aachen University, Aachen, Germany.

High-frequency applied cetalkonium chloride (CAC) and benzalkonium chloride (BAC) 0.02% did not hamper corneal healing in a living rabbit model of induced corneal erosion. In contrast, the eye irritation test (EVEIT) shows inhibition of healing for these substances. Read More

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December 2020

Anthropogenic and natural barriers affect genetic connectivity in an Alpine butterfly.

Mol Ecol 2021 01 26;30(1):114-130. Epub 2020 Nov 26.

Institute for Integrated Natural Sciences, Zoology, University Koblenz-Landau, Koblenz, Germany.

Dispersal is a key biological process serving several functions including connectivity among populations. Habitat fragmentation caused by natural or anthropogenic structures may hamper dispersal, thereby disrupting genetic connectivity. Investigating factors affecting dispersal and gene flow is important in the current era of anthropogenic global change, as dispersal comprises a vital part of a species' resilience to environmental change. Read More

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January 2021

Unveiling the Actual Functions of Awns in Grasses: From Yield Potential to Quality Traits.

Int J Mol Sci 2020 Oct 14;21(20). Epub 2020 Oct 14.

State Key Laboratory of Grassland Agro-Ecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, China.

Awns, which are either bristles or hair-like outgrowths of lemmas in the florets, are one of the typical morphological characteristics of grass species. These stiff structures contribute to grain dispersal and burial and fend off animal predators. However, their phenotypic and genetic associations with traits deciding potential yield and quality are not fully understood. Read More

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October 2020

Realization of Harmonic Oscillator Arrays with Graded Semiconductor Quantum Wells.

Phys Rev Lett 2020 Aug;125(9):097403

Department of Electrical and Computer Engineering, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada.

The harmonic oscillator is a foundational concept in both theoretical and experimental quantum mechanics. Here, we demonstrate harmonic oscillators in a semiconductor platform by faithfully implementing continuously graded alloy semiconductor quantum wells. Unlike current technology, this technique avoids interfaces that can hamper the system and allows for the production of multiwell stacks several micrometers thick. Read More

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Rural communities in Africa should not be forgotten in responses to COVID-19.

Int J Health Plann Manage 2020 Nov 13;35(6):1302-1305. Epub 2020 Aug 13.

Department of Global Health and Development, London School of Hygiene and Tropical Medicine, UK.

Rural areas in Africa make up a large proportion of the continent. Since the emergence of COVID-19 on the continent, major attention and responses have been placed on urban areas. Rural areas are typified by certain challenges which may serve as limitations to the provision of resources and tools for COVID-19 responses in these areas. Read More

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November 2020

Design of Self-Expanding Auxetic Stents Using Topology Optimization.

Front Bioeng Biotechnol 2020 14;8:736. Epub 2020 Jul 14.

School of Mechanical and Manufacturing Engineering, University of New South Wales, Sydney, NSW, Australia.

Implanting stents is the most efficient and minimally invasive technique for treating coronary artery diseases, but the risks of stent thrombosis (ST) and in-stent restenosis (IRS) hamper the healing process. There have been a variety of stents in market but dominated by design motifs. A systematic design method that can enhance deliverability, safety and efficacy is still in demand. Read More

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Stable high-capacity and high-rate silicon-based lithium battery anodes upon two-dimensional covalent encapsulation.

Nat Commun 2020 Jul 31;11(1):3826. Epub 2020 Jul 31.

CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, China.

Silicon is a promising anode material for lithium-ion and post lithium-ion batteries but suffers from a large volume change upon lithiation and delithiation. The resulting instabilities of bulk and interfacial structures severely hamper performance and obstruct practical use. Stability improvements have been achieved, although at the expense of rate capability. Read More

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The Vicious Cycle of Renal Lipotoxicity and Mitochondrial Dysfunction.

Front Physiol 2020 7;11:732. Epub 2020 Jul 7.

Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, United States.

The kidney is one of the most energy-demanding organs that require abundant and healthy mitochondria to maintain proper function. Increasing evidence suggests a strong association between mitochondrial dysfunction and chronic kidney diseases (CKDs). Lipids are not only important sources of energy but also essential components of mitochondrial membrane structures. Read More

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While We Wait for a Vaccine Against SARS-CoV-2, Why Not Think About Available Drugs?

Front Physiol 2020 3;11:820. Epub 2020 Jul 3.

Biomedical Research Institute (BIOMED), Argentina Pontifical Catholic University of Argentina (UCA) and National Scientific and Technical Research Council (CONICET), Buenos Aires, Argentina.

At the time of reception of this article (April 2, 2020), efforts to develop a specific vaccine against SARS-Cov-2, the causative agent of the coronavirus disease 2019 (COVID-19), had just begun trial phase 1, but full validation of this and other current developments is likely to take many more months to reach completion. The ongoing pandemic constitutes a major health burden of world proportions that is also having a devastating impact on whole economies worldwide, the knock-on effects of which could be catastrophic especially in poorer countries. Alternative measures to ameliorate the impact and hamper or minimally slow down disease progression are urgently called for. Read More

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Structural Characteristics in the γ Chain Variants Associated with Fibrinogen Storage Disease Suggest the Underlying Pathogenic Mechanism.

Int J Mol Sci 2020 Jul 20;21(14). Epub 2020 Jul 20.

Department of Pathology and Molecular Histopathology, Catholic University and Bugando Medical Centre, Mwanza P.O. Box 1464, Tanzania.

Particular fibrinogen γ chain mutations occurring in the γ-module induce changes that hamper γ-γ dimerization and provoke intracellular aggregation of the mutant fibrinogen, defective export and plasma deficiency. The hepatic storage predisposes to the development of liver disease. This condition has been termed hereditary hypofibrinogenemia with hepatic storage (HHHS). Read More

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A Potential Checkmate to Lead: Bismuth in Organometal Halide Perovskites, Structure, Properties, and Applications.

Adv Sci (Weinh) 2020 Jul 27;7(13):1903143. Epub 2020 May 27.

Zhejiang Province Key Laboratory of Quantum Technology and Devices and Department of Physics State Key Laboratory for Silicon Materials Zhejiang University Hangzhou 310027 P. R. China.

The remarkable optoelectronic properties and considerable performance of the organo lead-halide perovskites (PVKs) in various optoelectronic applications grasp tremendous scientific attention. However, the existence of the toxic lead in these compounds is threatening human health and remains a major concern in the way of their commercialization. To address this issue, numerous nontoxic alternatives have been reported. Read More

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Positively Charged Polymers as Promising Devices against Multidrug Resistant Gram-Negative Bacteria: A Review.

Polymers (Basel) 2020 May 23;12(5). Epub 2020 May 23.

Department of Surgical Sciences and Integrated Diagnostics (DISC), University of Genoa, Viale Benedetto XV, 6, I-16132 Genova, Italy.

Antibiotic resistance has increased markedly in Gram-negative bacteria, causing severe infections intractable with traditional drugs and amplifying mortality and healthcare costs. Consequently, to find novel antimicrobial compounds, active on multidrug resistant bacteria, is mandatory. In this regard, cationic antimicrobial peptides (CAMPs)-able to kill pathogens on contact-could represent an appealing solution. Read More

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Aromatic [b]-fused BODIPY dyes as promising near-infrared dyes.

Org Biomol Chem 2020 06;18(22):4135-4156

Laboratory of Functional Molecular Solids, Ministry of Education; School of Chemistry and Materials Science, Anhui Normal University, Wuhu, 241002, China.

Far-red and near-infrared (NIR) absorbing/emitting dyes have found diverse applications in biomedicine and material science. However, the absorption and emission of classical BODIPY chromophores at short wavelength hamper their applications. Several strategies have been adopted to modify the structure of the BODIPY core to design NIR dyes. Read More

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Preanalytical variables that affect the outcome of cell-free DNA measurements.

Crit Rev Clin Lab Sci 2020 11 12;57(7):484-507. Epub 2020 May 12.

Institute for Laboratory Medicine, German Heart Centre, Technical University Munich, Munich, Germany.

Fragments of cell-free DNA (cfDNA) in human body fluids often carry disease-specific alterations and are now widely recognized as ideal biomarkers for the detection and monitoring of genomic disorders, especially cancer, that are normally difficult to examine noninvasively. However, the conversion of promising research findings into tools useful in routine clinical testing of cancer has been a slow-moving process. A major reason is that the diagnostic sensitivity and specificity of cfDNA-based clinical assays are negatively impacted by a combination of suboptimal and inter-institutional differences in preanalytical procedures. Read More

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November 2020