47,030 results match your criteria perturbation protein-coding

Prediction and Boolean logical modelling of synergistic microRNA regulatory networks during reprogramming of male germline pluripotent stem cells.

Biosystems 2021 Jun 12;207:104453. Epub 2021 Jun 12.

Department of Biotechnology and Medical Engineering, National Institute of Technology Rourkela, Odisha 769008, India. Electronic address:

Unipotent male germline stem (GS) cells can undergo spontaneous reprogramming to germline pluripotent stem (GPS) cells during in vitro culture. In our previous study, we proposed a Boolean logical model of gene regulatory network (GRN) during reprogramming of GS cells to GPS cells. This study was designed to predict and model synergistic microRNA (miRNA) regulatory network during reprogramming of GS cells into GPS cells. Read More

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Is the diatom sex clock a clock?

J R Soc Interface 2021 Jun 16;18(179):20210146. Epub 2021 Jun 16.

Algorithmic Algebra and Discrete Mathematics, Institute of Mathematics, Faculty of Mathematics and Natural Sciences, University of Kassel, 34109 Kassel, Germany.

The unique life cycle of diatoms with continuous decreasing and restoration of the cell size leads to periodic fluctuations in cell size distribution and has been regarded as a multi-annual clock. To understand the long-term behaviour of a population analytically, generic mathematical models are investigated algebraically and numerically for their capability to describe periodic oscillations. Whereas the generally accepted simple concepts for the proliferation dynamics do not sustain oscillating behaviour owing to broadening of the size distribution, simulations show that a proposed limited lifetime of a newly synthesized cell wall slows down the relaxation towards a time-invariant equilibrium state to the order of a hundred thousand generations. Read More

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Transition between toroidic orders in dielectric metasurfaces by polarization of the incident wave.

Opt Lett 2021 Jun;46(12):2964-2967

We propose a design and perform a theoretical and experimental study of optical properties of a metasurface composed of hexagonal oligomers of dielectric particles that somewhat resemble characteristics of multiferroics. It can maintain both toroidic and antitoroidic orders in the dynamical response on irradiation by a linearly polarized plane wave. These orders originate from the dark states of toroidal dipole moments. Read More

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Transient Permeation Enhancer® (TPE®) technology for oral delivery of octreotide: a technological evaluation.

Expert Opin Drug Deliv 2021 Jun 15. Epub 2021 Jun 15.

School of Pharmacy and Biomolecular Sciences, Royal College of Surgeons in Ireland, St. Stephen's Green, Dublin 2, Ireland.

Introduction: : The FDA approval of oral semaglutide for type 2 diabetes (2019) and oral octreotide for acromegaly (2020) is evidence that selected niche peptides can be administered orally if formulated with selected intestinal permeation enhancers.

Areas Covered: We evaluated the oral octreotide formulation, MYCAPSSA® (Chiasma Pharmaceuticals, Needham, MA, USA). An outline of the current standard of care in acromegaly and the benefits of oral octreotide versus depot injections is provided. Read More

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Photophysical properties of -methyl and -acetyl substituted alloxazines: a theoretical investigation.

Phys Chem Chem Phys 2021 Jun 15. Epub 2021 Jun 15.

Institut für Physikalische und Theoretische Chemie, Universität Regensburg, Universitätsstr. 31, Regensburg, 93053, Germany.

The electronic structure and photophysical properties of a series of N-methyl and N-acetyl substituted alloxazines (AZs) were investigated with extensive density functional theory (DFT) and time-dependent density functional theory (TD-DFT) based calculations. We showed that non-radiative decays from the lowest singlet and triplet excited states of these AZs are dominant over their radiative counterparts. The fast non-radiative decays of the excited AZs can be attributed to the energy consumption (Ereorg) through structural reorganization facilitated by the intrinsic normal modes of the alloxazine framework, as well as their coupling with those of the functional groups. Read More

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Long-term effects of somatostatin analogues in rat GH-secreting pituitary tumor cell lines.

J Endocrinol Invest 2021 Jun 14. Epub 2021 Jun 14.

Laboratory of Geriatric and Oncologic Neuroendocrinology Research, Istituto Auxologico Italiano, IRCCS, Via Zucchi 18, 20095, Cusano Milanino, MI, Italy.

Purpose: First-generation somatostatin analogs, octreotide (OCT) and lanreotide, are the cornerstone for the medical treatment of growth hormone (GH)-secreting pituitary tumors. A new multireceptor analog, such as pasireotide (PAS), showed better activity than OCT in long-term treatment of patients with acromegaly, but modulation of intracellular key processes is still unclear in vitro. In this study, we evaluated the antitumor activity of OCT and PAS in two GH-secreting pituitary tumor cell lines, GH3 and GH4C1, after a long-term incubation. Read More

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Type I Interferon Transcriptional Network Regulates Expression of Coinhibitory Receptors in Human T cells.

Res Sq 2021 Jun 8. Epub 2021 Jun 8.

While inhibition of T cell co-inhibitory receptors has revolutionized cancer therapy, the mechanisms governing their expression on human T cells have not been elucidated. Type 1 interferon (IFN-I) modulates T cell immunity in viral infection, autoimmunity, and cancer, and may facilitate induction of T cell exhaustion in chronic viral infection. Here we show that IFN-I regulates co-inhibitory receptor expression on human T cells, inducing PD-1/TIM-3/LAG-3 while surprisingly inhibiting TIGIT expression. Read More

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Pre-operative exercise therapy triggers anti-inflammatory trained immunity of Kupffer cells through metabolic reprogramming.

Nat Metab 2021 Jun 14. Epub 2021 Jun 14.

Department of Surgery, The Ohio State University Wexner Medical Center, Columbus, OH, USA.

Pre-operative exercise therapy improves outcomes for many patients who undergo surgery. Despite the well-known effects on tolerance to systemic perturbation, the mechanisms by which pre-operative exercise protects the organ that is operated on from inflammatory injury are unclear. Here, we show that four-week aerobic pre-operative exercise significantly attenuates liver injury and inflammation from ischaemia and reperfusion in mice. Read More

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Perturbation of resting-state network nodes preferentially propagates to structurally rather than functionally connected regions.

Sci Rep 2021 Jun 14;11(1):12458. Epub 2021 Jun 14.

Berenson-Allen Center for Non-Invasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.

Combining Transcranial Magnetic Stimulation (TMS) with electroencephalography (EEG) offers the opportunity to study signal propagation dynamics at high temporal resolution in the human brain. TMS pulse induces a local effect which propagates across cortical networks engaging distant cortical and subcortical sites. However, the degree of propagation supported by the structural compared to functional connectome remains unclear. Read More

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A large multiethnic GWAS meta-analysis of cataract identifies new risk loci and sex-specific effects.

Nat Commun 2021 06 14;12(1):3595. Epub 2021 Jun 14.

Kaiser Permanente Northern California (KPNC), Division of Research, Oakland, CA, USA.

Cataract is the leading cause of blindness among the elderly worldwide and cataract surgery is one of the most common operations performed in the United States. As the genetic etiology of cataract formation remains unclear, we conducted a multiethnic genome-wide association meta-analysis, combining results from the GERA and UK Biobank cohorts, and tested for replication in the 23andMe research cohort. We report 54 genome-wide significant loci, 37 of which were novel. Read More

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Roux-en-Y gastric bypass-induced bacterial perturbation contributes to altered host-bacterial co-metabolic phenotype.

Microbiome 2021 Jun 14;9(1):139. Epub 2021 Jun 14.

Division of Digestive Disease, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, SW7 2AZ, UK.

Background: Bariatric surgery, used to achieve effective weight loss in individuals with severe obesity, modifies the gut microbiota and systemic metabolism in both humans and animal models. The aim of the current study was to understand better the metabolic functions of the altered gut microbiome by conducting deep phenotyping of bariatric surgery patients and bacterial culturing to investigate causality of the metabolic observations.

Methods: Three bariatric cohorts (n = 84, n = 14 and n = 9) with patients who had undergone Roux-en-Y gastric bypass (RYGB), sleeve gastrectomy (SG) or laparoscopic gastric banding (LGB), respectively, were enrolled. Read More

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Probing competing relaxation pathways in malonaldehyde with transient X-ray absorption spectroscopy.

Chem Sci 2020 Mar 25;11(16):4180-4193. Epub 2020 Mar 25.

Department of Chemistry, The PULSE Institute, Stanford University Stanford CA 94305 USA

Excited-state intramolecular hydrogen transfer (ESIHT) is a fundamental reaction relevant to chemistry and biology. Malonaldehyde is the simplest example of ESIHT, yet only little is known experimentally about its excited-state dynamics. Several competing relaxation pathways have been proposed, including internal conversion mediated by ESIHT and C[double bond, length as m-dash]C torsional motion as well as intersystem crossing. Read More

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Apoferritin-Engineered Nanoprobe for Tumor-Targeted Triple-NIR Imaging and Phototherapy.

Anal Chem 2021 Jun 14. Epub 2021 Jun 14.

State Key Laboratory of Radiation Medicine and Protection, School for Radiological and Interdisciplinary Sciences (RAD-X), Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Soochow University, Suzhou 215123, China.

Considering that pathological hallmarks are directly related to structural and chemical information of tumor, noninvasive, real-time, spatially resolved quantitative chemical imaging is significant for treatment decisions. The discovery of the transparency window of biological tissues and the advancement of near-infrared technology provide exciting prospects for imaging. Herein, an engineering apoferritin-conjugated cypate nanoprobe is fabricated for near-infrared photoacoustic imaging and fluorescence imaging in the first and second window. Read More

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Toward an Accurate Description of Low-Lying Singlet Excited States of Polyenes.

J Chem Theory Comput 2021 Jun 14. Epub 2021 Jun 14.

Department of Chemistry, Lomonosov Moscow State University, Moscow, 119991, Russia.

The low-lying excited states of carotenoids play a crucial role in many important biophysical processes such as photosynthesis. Most of these excited states are strongly correlated, which makes them both challenging for a qualitative description and an engaging model system for trying out emerging multireference methods. Among these methods, driven similarity renormalization group (DSRG) and its perturbative version (DSRG-MRPT2) are especially attractive in terms of both accuracy and moderate numerical complexity. Read More

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Novel Model for Rate Transient Analysis in Stress-Sensitive Shale Gas Reservoirs.

ACS Omega 2021 Jun 27;6(22):14015-14029. Epub 2021 May 27.

SINOPEC Key Laboratory of Shale Oil/Gas Exploration & Production, Beijing 100083, China.

Technical advances in hydraulic fracturing and horizontal drilling technologies enable shale to be commercially exploited. Due to the technical and economic limitations of well testing in shale gas plays, rate transient analysis has become a more attractive option. After hydraulic fracturing, flow mechanisms in multiple scaled pores of shale become extraordinarily complicated: adsorption in nanopores, diffusion in micropores, and non-Darcy flow in macropores. Read More

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Mitochondrial DNA Depletion in Granulosa Cell Derived Nuclear Transfer Tissues.

Front Cell Dev Biol 2021 14;9:664099. Epub 2021 May 14.

Molecular Animal Breeding and Biotechnology, Gene Center and Department of Veterinary Science, LMU Munich, Munich, Germany.

Somatic cell nuclear transfer (SCNT) is a key technology with broad applications that range from production of cloned farm animals to derivation of patient-matched stem cells or production of humanized animal organs for xenotransplantation. However, effects of aberrant epigenetic reprogramming on gene expression compromise cell and organ phenotype, resulting in low success rate of SCNT. Standard SCNT procedures include enucleation of recipient oocytes before the nuclear donor cell is introduced. Read More

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Folding-controlled assembly of -phenylene-based macrocycles.

Chem Sci 2021 Apr 14;12(20):6992-7002. Epub 2021 Apr 14.

Department of Chemistry & Biochemistry, Miami University Oxford OH 45056 USA

The self-assembly of foldamers into macrocycles is a simple approach to non-biological higher-order structure. Previous work on the co-assembly of -phenylene foldamers with rod-shaped linkers has shown that folding and self-assembly affect each other; that is, the combination leads to new emergent behavior, such as access to otherwise unfavorable folding states. To this point this relationship has been passive. Read More

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Elusive structural changes of New Delhi metallo-β-lactamase revealed by ultraviolet photodissociation mass spectrometry.

Chem Sci 2020 Aug 11;11(33):8999-9010. Epub 2020 Aug 11.

Department of Chemistry, University of Texas at Austin Austin TX 78712 USA

We use mass spectrometry (MS), under denaturing and non-denaturing solution conditions, along with ultraviolet photodissociation (UVPD) to characterize structural variations in New Delhi metallo-β-lactamase (NDM) upon perturbation by ligands or mutation. Mapping changes in the abundances and distributions of fragment ions enables sensitive detection of structural alterations throughout the protein. Binding of three covalent inhibitors was characterized: a pentafluorphenyl ester, an -aryloxycarbonyl hydroxamate, and ebselen. Read More

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Large transition state stabilization from a weak hydrogen bond.

Chem Sci 2020 Jul 2;11(28):7487-7494. Epub 2020 Jul 2.

Department of Chemistry and Biochemistry, University of South Carolina Columbia SC 29208 USA

A series of molecular rotors was designed to study and measure the rate accelerating effects of an intramolecular hydrogen bond. The rotors form a weak neutral O-H⋯O[double bond, length as m-dash]C hydrogen bond in the planar transition state (TS) of the bond rotation process. The rotational barrier of the hydrogen bonding rotors was dramatically lower (9. Read More

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Structural trends in the dehydrogenation selectivity of palladium alloys.

Chem Sci 2020 May 5;11(19):5066-5081. Epub 2020 May 5.

Davidson School of Chemical Engineering, Purdue University West Lafayette IN 47907 USA

Alloying is well-known to improve the dehydrogenation selectivity of pure metals, but there remains considerable debate about the structural and electronic features of alloy surfaces that give rise to this behavior. To provide molecular-level insights into these effects, a series of Pd intermetallic alloy catalysts with Zn, Ga, In, Fe and Mn promoter elements was synthesized, and the structures were determined using X-ray absorption spectroscopy (XAS) and synchrotron X-ray diffraction (XRD). The alloys all showed propane dehydrogenation turnover rates 5-8 times higher than monometallic Pd and selectivity to propylene of over 90%. Read More

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Neutrophil Extracellular Traps in Dengue Are Mainly Generated NOX-Independently.

Front Immunol 2021 26;12:629167. Epub 2021 May 26.

Department of Internal Medicine and the Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, Netherlands.

Neutrophil extracellular traps (NETs) are increasingly recognized to play a role in the pathogenesis of viral infections, including dengue. NETs can be formed NADPH oxidase (NOX)-dependently or NOX-independently. NOX-independent NETs can be induced by activated platelets and are very potent in activating the endothelium. Read More

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Anthropogenic disturbance favours generalist over specialist parasites in bird communities: Implications for risk of disease emergence.

Ecol Lett 2021 Jun 13. Epub 2021 Jun 13.

Indian Institute of Science Education and Research Tirupati, Tirupati, Andhra Pradesh, India.

Niche theory predicts specialists which will be more sensitive to environmental perturbation compared to generalists, a hypothesis receiving broad support in free-living species. Based on their niche breadth, parasites can also be classified as specialists and generalists, with specialists infecting only a few and generalists a diverse array of host species. Here, using avian haemosporidian parasites infecting wild bird populations inhabiting the Western Ghats, India as a model system, we elucidate how climate, habitat and human disturbance affects parasite prevalence both directly and indirectly via their effects on host diversity. Read More

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Endoplasmic reticulum stress in the acute intestinal epithelial injury of necrotizing enterocolitis.

Pediatr Surg Int 2021 Jun 12. Epub 2021 Jun 12.

Division of General and Thoracic Surgery, The Hospital for Sick Children, University of Toronto, 1526-555 University Ave, Toronto, ON, M5G 1X8, Canada.

Endoplasmic reticulum (ER) is a dynamic organelle that has many functions including protein synthesis, lipid synthesis, and calcium metabolism. Any perturbation in the ER such as accumulation of unfolded or misfolded proteins in the ER lumen causes ER stress. ER stress has been implicated in many intestinal inflammatory diseases. Read More

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3D Electron Diffraction Structure Determination of Terrylene, a Promising Candidate for Intermolecular Singlet Fission.

Chemphyschem 2021 Jun 12. Epub 2021 Jun 12.

University of Bristol, School of Chemistry, Cantocks Close, BS81TS, Bristol, UNITED KINGDOM.

Herein we demonstrate the prowess of the 3D electron diffraction approach by unveiling the structure of terrylene, the third member in the series of peri-condensed naphthalene analogues, which has eluded structure determination for 65 years. The structure was determined by direct methods using electron diffraction data and corroborated by dispersion-inclusive density functional theory optimizations. Terrylene crystalizes in the monoclinic space group P21/a, arranging in a sandwich-herringbone packing motif, similar to analogous compounds. Read More

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Assessing Early Cardiac Outflow Tract Adaptive Responses Through Combined Experimental-Computational Manipulations.

Ann Biomed Eng 2021 Jun 11. Epub 2021 Jun 11.

Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, 304 Weill Hall, Ithaca, NY, 14853-7202, USA.

Mechanical forces are essential for proper growth and remodeling of the primitive pharyngeal arch arteries (PAAs) into the great vessels of the heart. Despite general acknowledgement of a hemodynamic-malformation link, the direct correlation between hemodynamics and PAA morphogenesis remains poorly understood. The elusiveness is largely due to difficulty in performing isolated hemodynamic perturbations and quantifying changes in-vivo. Read More

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Loss of the transcriptional repressor Rev-erbα upregulates metabolism and proliferation in cultured mouse embryonic fibroblasts.

Sci Rep 2021 Jun 11;11(1):12356. Epub 2021 Jun 11.

Department of Molecular Biology, Cellular Biology, and Biochemistry, Brown University, 185 Meeting Street, Providence, RI, 02912, USA.

The transcriptional repressor Rev-erbα is known to down-regulate fatty acid metabolism and gluconeogenesis gene expression. In animal models, disruption of Rev-erbα results in global changes in exercise performance, oxidative capacity, and blood glucose levels. However, the complete extent to which Rev-erbα-mediated transcriptional repression of metabolism impacts cell function remains unknown. Read More

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Perturbation of ribosomal subunits dynamics by inhibitors of tRNA translocation.

RNA 2021 Jun 11. Epub 2021 Jun 11.

Max Planck Institute for Biophysical Chemistry

Many antibiotics that bind to the ribosome inhibit translation by blocking the movement of tRNAs and mRNA or interfering with ribosome dynamics, which impairs the formation of essential translocation intermediates. Here we show how translocation inhibitors viomycin (Vio), neomycin (Neo), paromomycin (Par), kanamycin (Kan), spectinomycin (Spc), hygromycin B (HygB), and streptomycin (Str, an antibiotic that does not inhibit tRNA movement), affect principal motions of the small ribosomal subunits (SSU) during EF-G-promoted translocation. Using ensemble kinetics, we studied the SSU body domain rotation and SSU head domain swiveling in real time. Read More

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The Impact of Vocal Task on Voice Acoustics, Effort and Discomfort Following Submandibular Neuromuscular Electrical Stimulation in Healthy Adults.

J Voice 2021 Jun 8. Epub 2021 Jun 8.

Department of Physical Therapy and Human Movement, Sacred Heart University, Fairfield, Connecticut; College of Health & Wellness, Johnson & Wales University, Providence, RI.

Background: Neuromuscular electrical stimulation (NMES) offers a potential adjuvant to traditional voice therapy for individuals with dysphonia. The type of vocal task to implement in conjunction with electrical stimulation to achieve maximal therapeutic benefit is unknown. The purpose of this study was to elucidate the impact of tasks on voice outcomes. Read More

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Effects of Medical Masks on Voice Assessment During the COVID-19 Pandemic.

J Voice 2021 May 9. Epub 2021 May 9.

Department of Otolaryngology-Head and Neck Surgery, Beijing Tongren Hospital, Capital Medical University, Beijing, China. Electronic address:

Objective: Voice assessment is of great significance to the evaluation of voice quality. Our study aims to explore the effects of medical masks on healthy people in acoustic, aerodynamic and formant parameters during the COVID-19 pandemic. In addition, we also attempted to verify the differences between different sexes and ages. Read More

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Numerical study of acoustophoretic manipulation of particles in microfluidic channels.

Proc Inst Mech Eng H 2021 Jun 11:9544119211024775. Epub 2021 Jun 11.

State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing, P.R. China.

The microfluidic technology based on surface acoustic waves (SAW) has been developing rapidly, as it can precisely manipulate fluid flow and particle motion at microscales. We hereby present a numerical study of the transient motion of suspended particles in a microchannel. In conventional studies, only the microchannel's bottom surface generates SAW and only the final positions of the particles are analyzed. Read More

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