371,856 results match your criteria challenge


Antithrombotic Management in Ischemic Stroke with Essential Thrombocythemia: Current Evidence and Dilemmas.

Med Princ Pract 2021 Apr 13. Epub 2021 Apr 13.

Thrombotic diseases like ischemic stroke are common complications of essential thrombocythemia (ET) due to abnormal megakaryopoiesis and platelet dysfunction. Ischemic stroke in ET can occur as a result of both cerebral arterial and venous thrombosis. Management of ET is aimed at preventing vascular complications including thrombosis. Read More

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Hollow Fiber and Nanofiber Membranes in Bioartificial Liver and Neuronal Tissue Engineering.

Cells Tissues Organs 2021 Apr 13:1-30. Epub 2021 Apr 13.

Institute on Membrane Technology, National Research Council of Italy, CNR-ITM, Rende, Italy.

To date, the creation of biomimetic devices for the regeneration and repair of injured or diseased tissues and organs remains a crucial challenge in tissue engineering. Membrane technology offers advanced approaches to realize multifunctional tools with permissive environments well-controlled at molecular level for the development of functional tissues and organs. Membranes in fiber configuration with precisely controlled, tunable topography, and physical, biochemical, and mechanical cues, can direct and control the function of different kinds of cells toward the recovery from disorders and injuries. Read More

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Automatic classification of idiopathic Parkinson's disease and atypical parkinsonian syndromes combining [C]raclopride PET uptake and MRI grey matter morphometry.

J Neural Eng 2021 Apr 13. Epub 2021 Apr 13.

Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), ICNAS Polo 3, Coimbra, 3000-548, PORTUGAL.

Objective: To explore the viability of developing a computer-aided diagnostic system for Parkinsonian syndromes using dynamic [11C]raclopride PET and T1-weighted MRI data.

Approach: The biological heterogeneity of Parkinsonian syndromes renders their statistical classification a challenge. The unique combination of structural and molecular imaging data allowed different classifier designs to be tested. Read More

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Spotting isomer mixtures in forensic illicit drug casework with GC-VUV using automated coelution detection and spectral deconvolution.

J Chromatogr B Analyt Technol Biomed Life Sci 2021 Mar 29;1173:122675. Epub 2021 Mar 29.

Van 't Hoff Institute for Molecular Sciences, University of Amsterdam, PO Box 94157, Amsterdam 1090 GD, the Netherlands; Co van Ledden Hulsebosch Center (CLHC), Amsterdam Center for Forensic Science and Medicine, PO Box 94157, Amsterdam 1090 GD, the Netherlands.

Analysis of isomeric mixtures is a significant analytical challenge. In the forensic field, for example, over 1000 new psychoactive substances (NPSs), comprising of many closely related and often isomeric varieties, entered the drugs-of-abuse market within the last decade. Unambiguous identification of the isomeric form requires advanced spectroscopic techniques, such as GC-Vacuum Ultraviolet Spectroscopy (GC-VUV). Read More

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Immune response and susceptibility of Nile tilapia fish to Aeromonas hydrophila infection following the exposure to Bifenthrin and/or supplementation with Petroselinum crispum essential oil.

Ecotoxicol Environ Saf 2021 Apr 10;216:112205. Epub 2021 Apr 10.

Forensic Medicine and Toxicology Department, Faculty of Veterinary Medicine, University of Sadat City, 32897, Egypt.

Bifenthrin (BF) is a widely used 3rd generation type I pyrethroid with a potential toxic effect in fish. Nevertheless, its effect on the immune system remains unclear. In the present study, Oreochromis niloticus was exposed to BF at 0. Read More

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Inflammatory tumor microenvironment responsive neutrophil exosomes-based drug delivery system for targeted glioma therapy.

Biomaterials 2021 Mar 31;273:120784. Epub 2021 Mar 31.

School of Medicine, Chongqing University, Chongqing, 400044, China; Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing, 400044, China. Electronic address:

Clinical treatment of malignant glioma remains a major challenge due to high infiltrative growth and chemotherapeutic resistance of tumors and the presence of the blood brain barrier (BBB). Advanced nanoplatforms that can efficiently cross the BBB and target to brain tumor are urgently needed. Encouraged by the intrinsic inflammatory chemotaxis and excellent BBB-crossing capability of neutrophils, a bioinspired neutrophil-exosomes (NEs-Exos) system for delivering loaded doxorubicin (DOX) drug for glioma treatment is proposed and systematically investigated. Read More

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Ultrathin chalcogenide nanosheets for photoacoustic imaging-guided synergistic photothermal/gas therapy.

Biomaterials 2021 Apr 7;273:120807. Epub 2021 Apr 7.

State Key Laboratory of Chemical Resource Engineering, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, PR China. Electronic address:

Previous preclinical and clinical studies have shown that using only a single therapy makes it difficult to completely eradicate tumors and restrain cancer metastasis. To overcome this challenge, multi-modal synergistic treatments have attracted considerable attention. Herein, an ultrathin Cu-loaded CoCuFe-selenide (CCFS) was prepared by a facile topotactic transformation from CoCuFe layered double hydroxide (LDH) nanosheets (NSs), followed by surface modification with polyvinyl pyrrolidone (PVP) and l-arginine (L-Arg). Read More

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An affinity prediction approach for the ligand of E3 ligase Cbl-b and an insight into substrate binding pattern.

Bioorg Med Chem 2021 Apr 2;38:116130. Epub 2021 Apr 2.

State Key Laboratory of Natural Medicines, and Jiang Su Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing 210009, China; Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China. Electronic address:

Protein-protein interactions (PPIs) are essentially fundamental to all cellular processes, so that developing small molecule inhibitors of PPIs have great significance despite representing a huge challenge. Studying PPIs with the help of peptide motifs could obtain the structural information and reference significance to reduce the difficulty in the development of small molecules. Computational methods are powerful tools to characterize peptide-protein interactions, especially molecular dynamics simulation and binding free energy calculation. Read More

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Validation of a high-throughput method for analysis of pesticide residues in hemp and hemp products.

J Chromatogr A 2021 Mar 27;1645:462097. Epub 2021 Mar 27.

Programa de Investigación y Análisis de Residuos y Contaminantes Químicos (PRINARC), Facultad de Ingeniería Química, Universidad Nacional del Litoral, 3000 Santa Fe, Argentina.

Hemp has been an agricultural commodity for millennia, and it has been undergoing a resurgence in interest and production due to its high content of cannabinoids, protein, fiber and other ingredients. For legal possession and use throughout the USA, hemp and hemp products must have delta-9-tetrahydrocannabinol (THC) concentration < 0.3%. Read More

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Chemical fingerprinting strategies based on comprehensive two-dimensional gas chromatography combined with gas chromatography-olfactometry to capture the unique signature of Piemonte peppermint essential oil (Mentha x piperita var Italo-Mitcham).

J Chromatogr A 2021 Mar 26;1645:462101. Epub 2021 Mar 26.

Soremartec Italia srl, Alba, Cuneo Italy.

Accurate, reliable, and informative mapping of untargeted and targeted components across many samples is here performed by combining off-line GC-Olfactometry (GC-O) and comprehensive two-dimensional gas chromatography (GC×GC) coupled to time-of-flight mass spectrometry with variable ionization energy (TOF MS featuring Tandem Ionization™). In particular, untargeted and targeted (UT) features patterns are processed by chromatographic fingerprinting, giving differential priority to potent odorants' retention-times regions. Distinguishing peppermint essential oil (EO) from Piedmont (Italy - Mentha × piperita L. Read More

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Characterization of mandarin fish (Siniperca chuatsi) IL-6 and IL-6 signal transducer and the association between their SNPs and resistance to ISKNV disease.

Fish Shellfish Immunol 2021 Apr 10. Epub 2021 Apr 10.

Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of Fishery Drug Development, Ministry of Agriculture and Rural Affairs, Key Laboratory of Aquatic Animal Immune Technology, Guangdong Provinces, Guangzhou, 510380, China.

In fish, interleukin-6 (IL-6) is a very important immune-regulatory cytokine that plays a polyfunctional role in inflammation, metabolism, regeneration, and neural processes. IL-6 signal transducer (IL-6ST) is a specific receptor for IL-6 and expressed mainly in immune cells and hepatocytes. In this study, the complete cDNA and genomic DNA sequences of mandarin fish (Siniperca chuatsi) IL-6 and IL-6ST genes were identified and analyzed. Read More

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Exploiting Nut Cross Reactivity to Facilitate Real World Treatment of Tree Nut Allergy.

Ann Allergy Asthma Immunol 2021 Apr 10. Epub 2021 Apr 10.

Windom Allergy Asthma and Sinus, Sarasota, Florida.

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Comparing the NAC and EEU Models of Allergic Rhinitis.

Ann Allergy Asthma Immunol 2021 Apr 10. Epub 2021 Apr 10.

Department of Medicine, Queen's University, Kingston, ON, Canada; Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON, Canada; Allergy Research Unit, Kingston Health Sciences Center - KGH Site, Kingston, ON, Canada. Electronic address:

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Sleep: Opening a portal to the dreaming brain.

Curr Biol 2021 Apr;31(7):R352-R353

Université de Montréal, Montreal, QC H3C 3J7, Canada.

The retrospective nature of dream reports represents a challenge to the study of dreams. Two-way, real-time communication between researchers and lucid dreamers immersed in REM sleep offers a new and exciting window into the study of dreams and dreaming. Read More

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Mechanobiology: Forging a strong matrix at tendons.

Curr Biol 2021 Apr;31(7):R347-R350

Turing Center for Living Systems, Aix Marseille University, CNRS, IBDM, 13288 Marseille, France. Electronic address:

Nature faces the challenge of stably attaching soft muscles to a stiff skeleton. A new study combines live imaging and fly genetics to reveal that mechanical tension and a putative intracellular chaperone assist in assembling the gigantic extracellular matrix protein Dumpy at fly tendon-skeleton interfaces. Read More

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Programmable protein circuit design.

Cell 2021 Apr 5. Epub 2021 Apr 5.

Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA; Howard Hughes Medical Institute, California Institute of Technology, Pasadena, CA 91125, USA. Electronic address:

A fundamental challenge in synthetic biology is to create molecular circuits that can program complex cellular functions. Because proteins can bind, cleave, and chemically modify one another and interface directly and rapidly with endogenous pathways, they could extend the capabilities of synthetic circuits beyond what is possible with gene regulation alone. However, the very diversity that makes proteins so powerful also complicates efforts to harness them as well-controlled synthetic circuit components. Read More

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African and Asian leopards are highly differentiated at the genomic level.

Curr Biol 2021 Apr 10. Epub 2021 Apr 10.

Institute for Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam, Germany.

Leopards are the only big cats still widely distributed across the continents of Africa and Asia. They occur in a wide range of habitats and are often found in close proximity to humans. But despite their ubiquity, leopard phylogeography and population history have not yet been studied with genomic tools. Read More

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Low risk of SARS-CoV-2 in blood transfusion.

PLoS One 2021 13;16(4):e0249069. Epub 2021 Apr 13.

Kumasi Centre for Collaborative Research in Tropical Medicine, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.

Background: The novel coronavirus disease (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), continues to remain a global challenge. There is emerging evidence of SARS-CoV-2 virus found in the blood of patients from China and some developed countries. However, there is inadequate data reported in Ghana and other parts of Africa, where blood transfusion service heavily relies on voluntary and replacement blood donors. Read More

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Two Cases of Spontaneous Isolated Dissection of Superior Mesenteric Artery in One Night: Report of a (Noninvasive) Double Challenge.

Am J Case Rep 2021 Apr 13;22:e929538. Epub 2021 Apr 13.

Department of Medical Surgical Sciences and Advanced Technologies "GF Ingrassia" - Radiology Unit I, University Hospital "Policlinico-San Marco", Catania, Italy.

BACKGROUND Spontaneous isolated dissection of the superior mesenteric artery (SID-SMA) is a rare but potentially fatal condition. Although many cases of SID-SMA have been reported in the literature in recent years because of the increased use of contrast-enhanced computed tomography (CT) scanning, optimal management has not yet been firmly established. CASE REPORT We report 2 cases of SID-SMA that were managed with stenting and angioplasty via transfemoral access. Read More

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TREM2 Dictates Antibacterial Defense and Viability of Bone Marrow-derived Macrophages During Bacterial Infection.

Am J Respir Cell Mol Biol 2021 Apr 13. Epub 2021 Apr 13.

Zhejiang University School of Medicine First Affiliated Hospital, 71069, Anesthesiology and Intensive Care, Hangzhou, China;

Macrophages undergo profound metabolic reprogramming to join key immunoregulatory functions, which can be initiated by pattern recognition receptors. TREM2, a macrophage phagocytic receptor, plays pivotal roles in sepsis by enhancing bacterial clearance, which is associated with regulation of reactive oxygen species (ROS) production. However, how intracellular ROS participate in TREM2-mediated bactericidal activity remains unclear. Read More

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The academic success of boys and girls as an identity issue in gender relations: when the most threatened is not the one expected.

J Soc Psychol 2021 Apr 13:1-22. Epub 2021 Apr 13.

The present research aims to determine whether girls' higher academic achievement, which should grant them a higher academic status than boys, could prevent them from experiencing social-identity threat on this dimension. Because they fear situations questioning their superiority, we argue that an unfavorable intergroup comparison would be more threatening for the high-status, rather than low-status, group on the dimension of academic achievement. Two studies were conducted, respectively, in high school, where girls should represent the high-status group (Study 1), and middle school, where students might perceive their own group as the high-status group (Study 2). Read More

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Three Synchronous Head and Neck Cancers: A Multidisciplinary and Surgical Challenge.

Ear Nose Throat J 2021 Apr 13:1455613211007946. Epub 2021 Apr 13.

ENT Department, 472601Degli Infermi Hospital, Biella, Italy.

Second primary cancer (SPC) is a term used to describe a new primary cancer occurring in patients who had formerly been diagnosed with tumor. Even though SPCs appear to be related to primary cancers, they are actually entities that have arisen independently and not as a result of recurrence. This report is of the first case in literature of a patient hospitalized for the surgical treatment of 3 synchronous Head and Neck Cancers. Read More

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Bleeding and Thrombotic Adverse Events in Hospitalized Patients Under Empiric Treatment for Suspected Heparin-Induced Thrombocytopenia While Awaiting Confirmatory Testing.

Clin Appl Thromb Hemost 2021 Jan-Dec;27:1076029621996473

Hematology, 23217Thomas Jefferson University Hospital, Philadelphia, PA, USA.

Empiric management in suspected heparin-induced thrombocytopenia (HIT) is challenging due to imperfect prediction models, latency while awaiting test results and risks of empiric therapies. When there is high clinical suspicion for HIT, cessation of heparin and empiric non-heparin anticoagulation with FDA-approved argatroban is recommended. Alternatively off-label fondaparinux or watchful waiting have been utilized in clinical practice. Read More

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Hierarchical Self-Assembly of Nanowires on the Surface by Metallo-Supramolecular Truncated Cuboctahedra.

J Am Chem Soc 2021 Apr 13. Epub 2021 Apr 13.

College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, Guangdong 518060, China.

Parastichy, the spiral arrangement of plant organs, is an example of the long-range apparent order seen in biological systems. These ordered arrangements provide scientists with both an aesthetic challenge and a mathematical inspiration. Synthetic efforts to replicate the regularity of parastichy may allow for molecular-scale control over particle arrangement processes. Read More

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Dual-Colored Fluorescence Imaging of Mitochondrial HNO and Golgi-HNO in Mice with DILI.

Anal Chem 2021 Apr 13. Epub 2021 Apr 13.

College of Chemistry, Chemical Engineering and Materials Science, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Institutes of Biomedical Sciences, Shandong Normal University, Jinan 250014, People's Republic of China.

Drug-induced liver injury (DILI) is the most common reason for the post-marketing withdrawal of drugs. Poor understanding of the mechanisms of DILI presents a large challenge in clinical diagnosis. Previous evidences indicate a potential relationship between reactive nitrogen species (RNS) and DILI. Read More

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Natural Silk Nanofibril Aerogels with Distinctive Filtration Capacity and Heat-Retention Performance.

ACS Nano 2021 Apr 13. Epub 2021 Apr 13.

Department of Biomedical Engineering, Tufts University, Medford, Massachusetts 02155, United States.

Nanofibrous aerogels have been extensively developed as multifunctional substrates in a wide range of fields. Natural silk nanofibrils (SNFs) are an appealing biopolymer due to their natural abundance, mechanical toughness, biodegradability, and excellent biocompatibility. However, fabricating 3D SNF materials with mechanical flexibility remains a challenge. Read More

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Ocular Imaging for Enhancing the Understanding, Assessment, and Management of Age-Related Macular Degeneration.

Adv Exp Med Biol 2021 ;1256:33-66

Doheny Image Reading Center, Doheny Eye Institute, Los Angeles, CA, USA.

Age-related macular degeneration (AMD) is a progressive neuro-retinal disease and the leading cause of central vision loss among elderly individuals in the developed countries. Modern ocular imaging technologies constitute an essential component of the evaluation of these patients and have contributed extensively to our understanding of the disease. A challenge with any review of ocular imaging technologies is the rapid pace of progress and evolution of these instruments. Read More

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January 2021

CRISPR Interference and Activation to Modulate Transcription in Yarrowia lipolytica.

Methods Mol Biol 2021 ;2307:95-109

Chemical and Environmental Engineering, University of California Riverside, Riverside, CA, USA.

Recent developments in RNA-guided nuclease technologies have advanced the engineering of a wide range of organisms, including the nonconventional yeast Yarrowia lipolytica. Y. lipolytica has been the focus of a range of synthetic biology and metabolic engineering studies due to its high capacity to synthesize and accumulate intracellular lipids. Read More

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January 2021

Single-Stranded DNA Curtains for Single-Molecule Visualization of Rad51-ssDNA Filament Dynamics.

Methods Mol Biol 2021 ;2281:193-207

Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA.

Homologous recombination (HR) is a highly conserved DNA repair pathway required for the accurate repair of DNA double-stranded breaks. DNA recombination is catalyzed by the RecA/Rad51 family of proteins, which are conserved from bacteria to humans. The key intermediate catalyzing DNA recombination is the presynaptic complex (PSC), which is a helical filament comprised of Rad51-bound single-stranded DNA (ssDNA). Read More

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January 2021

Two people, one graph: the effect of rotated viewpoints on accessibility of data visualizations.

Cogn Res Princ Implic 2021 Apr 13;6(1):31. Epub 2021 Apr 13.

Leibniz-Institut Für Wissensmedien, Schleichstr. 6, 72076, Tübingen, Germany.

In co-located, multi-user settings such as multi-touch tables, user interfaces need to be accessible from multiple viewpoints. In this project, we investigated how this goal can be achieved for depictions of data in bar graphs. We designed a laboratory task in which participants answered simple questions based on information depicted in bar graphs presented from differently rotated points of view. Read More

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