13,216 results match your criteria interference contrast

Non-cationic Material Design for Nucleic Acid Delivery.

Adv Ther (Weinh) 2020 Mar 13;3(3). Epub 2020 Feb 13.

Department of Chemistry, University of Massachusetts Amherst, Amherst, MA, 01003, USA.

Nucleic acid delivery provides effective options to control intracellular gene expression and protein production. Efficient delivery of nucleic acid typically requires delivery vehicles to facilitate the entry of nucleic acid into cells. Among non-viral delivery vehicles, cationic materials are favored because of their high loading capacity of nucleic acids and prominent cellular uptake efficiency through electrostatic interaction. Read More

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Elementary processes of DNA surface hybridization resolved by single-molecule kinetics: implication for macroscopic device performance.

Chem Sci 2020 Dec 22;12(6):2217-2224. Epub 2020 Dec 22.

Department of Chemistry, School of Science, Tokyo Institute of Technology 2-12-1 W4-11 Ookayama Meguro-ku Tokyo 152-8551 Japan

Direct monitoring of single-molecule reactions has recently become a promising means of mechanistic investigation. However, the resolution of reaction pathways from single-molecule experiments remains elusive, primarily because of interference from extraneous processes such as bulk diffusion. Herein, we report a single-molecule kinetic investigation of DNA hybridization on a metal surface, as an example of a bimolecular association reaction. Read More

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December 2020

A representational similarity analysis of cognitive control during color-word Stroop.

J Neurosci 2021 Jun 18. Epub 2021 Jun 18.

Department of Psychological & Brain Sciences, Washington University in St. Louis, STL, MO, USA 63130.

Progress in understanding the neural bases of cognitive control has been supported by the paradigmatic color-word Stroop task, in which a target response (color name) must be selected over a more automatic, yet potentially incongruent, distractor response (word). For this paradigm, models have postulated complementary coding schemes: dorsomedial frontal cortex (DMFC) is proposed to evaluate the demand for control via incongruency-related coding, whereas dorsolateral prefrontal cortex (DLPFC) is proposed to implement control via goal and target-related coding. Yet, mapping these theorized schemes to measured neural activity within this task has been challenging. Read More

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Neurocognitive subprocesses of working memory performance.

Cogn Affect Behav Neurosci 2021 Jun 21. Epub 2021 Jun 21.

University of California Los Angeles, Los Angeles, CA, USA.

Working memory (WM) has been defined as the active maintenance and flexible updating of goal-relevant information in a form that has limited capacity and resists interference. Complex measures of WM recruit multiple subprocesses, making it difficult to isolate specific contributions of putatively independent subsystems. The present study was designed to determine whether neurophysiological indicators of proposed subprocesses of WM predict WM performance. Read More

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Use of magnetic nanotrap particles in capturing Yersinia pestis virulence factors, nucleic acids and bacteria.

J Nanobiotechnology 2021 Jun 21;19(1):186. Epub 2021 Jun 21.

School of Systems Biology, George Mason University, Manassas, VA, 20110, USA.

Background: Many pathogens, including Yersinia pestis, cannot be consistently and reliably cultured from blood. New approaches are needed to facilitate the detection of proteins, nucleic acid and microorganisms in whole blood samples to improve downstream assay performance. Detection of biomarkers in whole blood is difficult due to the presence of host proteins that obscure standard detection mechanisms. Read More

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Speckle-dependent accuracy in phase-sensitive optical coherence tomography.

Opt Express 2021 May;29(11):16950-16968

Phase-sensitive optical coherence tomography (OCT) is used to measure motion in a range of techniques, such as Doppler OCT and optical coherence elastography (OCE). In phase-sensitive OCT, motion is typically estimated using a model of the OCT signal derived from a single reflector. However, this approach is not representative of turbid samples, such as tissue, which exhibit speckle. Read More

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Thymol as an Interesting Building Block for Promising Fungicides against .

J Agric Food Chem 2021 Jun 21. Epub 2021 Jun 21.

Programa de Pós-Graduação em Agroquímica, Universidade Federal do Espírito Santo, 29500000, Alegre, Espirito Santo, Brazil.

The semisynthesis of 15 new thymol derivatives was achieved through Williamson synthesis and copper-catalyzed azide-alkyne cycloaddition (CuAAC) approaches. The reaction of CuAAC using the "" strategy, in the presence of an alkynyl thymol derivative and commercial or prepared azides, provided nine thymol derivatives under microwave irradiation. This procedure reduces reaction time and cost. Read More

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Misdirected attentional focus in functional tremor.

Brain 2021 Jun 18. Epub 2021 Jun 18.

Neuroscience Research Centre, Institute of Molecular and Cell Sciences, St George's University of London, London, SW17 0QT, UK.

A characteristic and intriguing feature of functional neurological disorder is that symptoms typically manifest with attention and improve or disappear with distraction. Attentional phenomena are therefore likely to be important in functional neurological disorder, but exactly how this manifests is unknown. The aim of the study was to establish whether in functional tremor the attentional focus is misdirected, and if this misdirection is detrimental to the movement, or rather reflects a beneficial compensatory strategy. Read More

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Design and analysis of a compact subwavelength-grating-assisted 1.55/2  µm wavelength demultiplexer.

Appl Opt 2021 Jun;60(16):4972-4975

The wavelength demultiplexer (deWMUX) is an indispensable component for the wavelength diversity system. In this paper, we propose a subwavelength-grating-assisted ${{1}} \times {{2}}$ deWMUX based on the principle of multimode interference, which aims to output 1.55 and 2 µm wavelengths from two different channels. Read More

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Effect of scavenging on predation in a food web.

Ecol Evol 2021 Jun 3;11(11):6742-6765. Epub 2021 May 3.

Department of Arctic and Marine Biology UiT The Arctic University of Norway Tromsø Norway.

Scavenging can have important consequences for food web dynamics, for example, it may support additional consumer species and affect predation on live prey. Still, few food web models include scavenging. We develop a dynamic model that includes two facultative scavenger species, which we refer to as the predator or scavenger species according to their natural scavenging propensity, as well as live prey, and a carrion pool to show ramifications of scavenging for predation in simple food webs. Read More

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Circularly Polarized Plasmons in Chiral Gold Nanowires via Quantum-Mechanical Design.

J Phys Chem Lett 2021 Jun 17:5829-5835. Epub 2021 Jun 17.

Dipartimento di Scienze Chimiche e Farmaceutiche, Università di Trieste, Via Giorgieri 1, 34127 Trieste, Italy.

Time-dependent density functional theory (TDDFT) simulations are conducted on a series of chiral gold nanowires to explore whether an enhancement of circular dichroism at the plasmon resonance is possible and identify its quantum-mechanical origin. We find that in linear two-dimensional chiral nanowires the dichroic response is suppressed by destructive interference of nearly degenerate components with opposite signs, pointing to this phenomenon as a common and likely origin of the difficulty encountered so far in achieving a plasmonic CD response in experiment and suggesting nevertheless that these opposite components could be "decoupled" by using multiwall arrangements. In contrast, we predict a giant dichroic response for nanowires with three-dimensional helical coiling. Read More

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Chemical Sectioning for Immunofluorescence Imaging.

Anal Chem 2021 Jun 17. Epub 2021 Jun 17.

Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, Hubei 430074, China.

Immunofluorescence (IF) is a powerful investigative tool in biological research and medical diagnosis, whereas conventional imaging methods are always conflict between speed, contrast/resolution, and specimen volume. Chemical sectioning (CS) is an effective method to overcome the conflict, which works by chemically manipulating the off/on state of fluorescent materials and turning on only the extremely superficial surface fluorescence of tissues to realize the sectioning capacity of wide-field imaging. However, the current mechanism of CS is only applicable to samples labeled with pH-sensitive fluorescent proteins and still cannot fulfill samples immunolabeled with frequently used commercial fluorescent dyes. Read More

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Full-field measurement of complex objects illuminated by an ultrashort pulse laser using delay-line sweeping off-axis interferometry.

Opt Lett 2021 Jun;46(12):2803-2806

Measuring the complex field of ultrashort pulse lasers plays a fundamental role in light wavefront manipulation and nonlinear phenomena investigation; yet, it still constitutes a challenge for both full-field and high-resolution characterization due to the short coherent length. We proposed and implemented an off-axis interference system with a delay-line sweeping technique to overcome the fringe contrast degradation caused by the envelope mismatch between interfering pulses, resulting in an increased effective analysis area. The effectiveness of the proposed method was first demonstrated by measuring a complex field generated by a phase-only spatial light modulator, where a four-pixel binning technique was adopted for both amplitude and phase modulation; then it was used for the measurement of the second harmonic generation signal of a urea crystal sample. Read More

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Microglia proliferation plays distinct roles in acquired epilepsy depending on disease stages.

Epilepsia 2021 Jun 15. Epub 2021 Jun 15.

Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milan, Italy.

Objective: Microgliosis occurs in animal models of acquired epilepsy and in patients. It includes cell proliferation that is associated with seizure frequency and decreased neuronal cells in human epilepsy. The role of microglia proliferation in the development of acquired epilepsy is unknown; thus, we examined its contribution to spontaneous seizure, neurodegeneration, and cognitive deficits in different disease phases. Read More

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Effects of Spaceflight on Musculoskeletal Health: A Systematic Review and Meta-analysis, Considerations for Interplanetary Travel.

Sports Med 2021 Jun 11. Epub 2021 Jun 11.

Human Performance Laboratory, Directorate of Psychology and Sport, University of Salford, Salford, GM, UK.

Background: If interplanetary travel is to be successful over the coming decades, it is essential that countermeasures to minimize deterioration of the musculoskeletal system are as effective as possible, given the increased duration of spaceflight associated with such missions. The aim of this review, therefore, is to determine the magnitude of deconditioning of the musculoskeletal system during prolonged spaceflight and recommend possible methods to enhance the existing countermeasures.

Methods: A literature search was conducted using PubMed, Ovid and Scopus databases. Read More

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RNAi of vacuolar-type H-ATPase genes causes growth delay and molting defect in .

Bull Entomol Res 2021 Jun 11:1-10. Epub 2021 Jun 11.

Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing210095, China.

Henosepilachna vigintioctopunctata is one of the most serious insect pests to a large number of nightshades and cucurbits. RNA interference (RNAi) triggered by double-stranded RNA (dsRNA) offers a reduced risk approach to control the beetle. Identification of amenable target genes and determination of appropriate life stage for dsRNA treatment are two critical steps in order to improve RNAi efficiency. Read More

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Translation and codon usage regulate Argonaute slicer activity to trigger small RNA biogenesis.

Nat Commun 2021 06 9;12(1):3492. Epub 2021 Jun 9.

Mechanisms of Epigenetic Inheritance, Department of Developmental and Stem Cell Biology, Institut Pasteur, UMR3738, CNRS, Paris, France.

In the Caenorhabditis elegans germline, thousands of mRNAs are concomitantly expressed with antisense 22G-RNAs, which are loaded into the Argonaute CSR-1. Despite their essential functions for animal fertility and embryonic development, how CSR-1 22G-RNAs are produced remains unknown. Here, we show that CSR-1 slicer activity is primarily involved in triggering the synthesis of small RNAs on the coding sequences of germline mRNAs and post-transcriptionally regulates a fraction of targets. Read More

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The effect of the gene in body colour masculinization of the damselfly .

Biol Lett 2021 06 9;17(6):20200761. Epub 2021 Jun 9.

Graduate School of Life Sciences, Tohoku University, 6-3 Aramaki, Aoba, Sendai 980-8578, Japan.

Odonata species display a remarkable diversity of colour patterns, including intrasexual polymorphisms. In the damselfly (), the expression of a sex-determining transcription factor, the () gene is reportedly associated with female colour polymorphism (CP) (gynomorph for female-specific colour and andromorph for male-mimicking colour). Here, the function of in thoracic coloration was investigated by electroporation-mediated RNA interference (RNAi). Read More

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AIE-based nanoaggregate tracker: high-fidelity visualization of lysosomal movement and drug-escaping processes.

Chem Sci 2020 Aug 28;11(47):12755-12763. Epub 2020 Aug 28.

Shanghai Key Laboratory of Functional Materials Chemistry, Key Laboratory for Advanced Materials, Institute of Fine Chemicals, Joint International Research Laboratory of Precision Chemistry and Molecular Engineering, Feringa Nobel Prize Scientist Joint Research Center, Frontiers Science Center for Materiobiology and Dynamic Chemistry, School of Chemistry and Molecular Engineering, East China University of Science and Technology Shanghai 200237 China

High-fidelity imaging and long-term visualization of lysosomes are crucial for their functional evaluation, related disease detection and active drug screening. However, commercial aggregation-caused quenching probes are not conducive to precise lysosomal imaging because of their inherent drawbacks, like easy diffusion, short emission and small Stokes shift, let alone their long-term tracing due to rapid photobleaching. Herein we report a novel aggregation-induced emission (AIE)-based TCM-PI nanoaggregate tracker for direct visualization of lysosomes based on the building block of tricyano-methylene-pyridine (TCM), wherein introduced piperazine (PI) groups behave as targeting units to lysosomes upon protonation, and the self-assembled nanostructure contributes to fast endocytosis for enhanced targeting ability as well as extended retention time for long-term imaging. Read More

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Vitamin E succinate exerts anti-tumour effects on human cervical cancer cells via the CD47-SIRPɑ pathway both and .

J Cancer 2021 5;12(13):3877-3886. Epub 2021 May 5.

Institute of Basic Medical Sciences, Qilu Hospital of Shandong University, School of Medicine, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China.

Vitamin E succinate (RRR-a-tocopheryl succinate, VES) acts as a potent agent for cancer therapy and has no toxic and side effects on normal tissue cells. However, the mechanism by which VES mediates the effects are not yet fully understood. Here, we hypothesised that VES mediates antitumour activity on human cervical cancer cells via the CD47-SIRPɑ pathway and . Read More

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Distinct Roles of Hemocytes at Different Stages of Infection by Dengue and Zika Viruses in Mosquitoes.

Front Immunol 2021 13;12:660873. Epub 2021 May 13.

Department of Biochemistry and Immunology, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.

mosquitoes are vectors for arboviruses of medical importance such as dengue (DENV) and Zika (ZIKV) viruses. Different innate immune pathways contribute to the control of arboviruses in the mosquito vector including RNA interference, Toll and Jak-STAT pathways. However, the role of cellular responses mediated by circulating macrophage-like cells known as hemocytes remains unclear. Read More

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From Non-symbolic to Symbolic Proportions and Back: A Cuisenaire Rod Proportional Reasoning Intervention Enhances Continuous Proportional Reasoning Skills.

Front Psychol 2021 21;12:633077. Epub 2021 May 21.

Department of Psychology, Rutgers University, Newark, NJ, United States.

The persistent educational challenges that fractions pose call for developing novel instructional methods to better prepare students for fraction learning. Here, we examined the effects of a 24-session, Cuisenaire rod intervention on a building block for symbolic fraction knowledge, continuous and discrete non-symbolic proportional reasoning, in children who have yet to receive fraction instruction. Participants were 34 second-graders who attended the intervention (intervention group) and 15 children who did not participate in any sessions (control group). Read More

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Biocompatible zinc gallogermanate persistent luminescent nanoparticles for fast tumor drainage lymph node imaging in vivo.

Colloids Surf B Biointerfaces 2021 May 29;205:111887. Epub 2021 May 29.

Key Laboratory of Pollution Control Chemistry and Environmental Functional Materials for Qinghai-Tibet Plateau of the National Ethnic Affairs Commission, School of Chemistry and Environment, Southwest Minzu University, Chengdu, 610041, China. Electronic address:

Tumor drainage lymph node identification and dissection are crucial for the oncological surgery to prevent/delay the recurrence. However, commercial imaging reagents distinguish the lymph nodes by staining them dark, which would be seriously interfered by blood and surrounding tissues. In this study, we reported the Cr/Pr-doped zinc gallogermanate persistent luminescent nanoparticles (PLNPs) for fast tumor drainage lymph node imaging with high contrast. Read More

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Heart rate variability as a predictor of improvement in emotional interference in Generalized Anxiety Disorder.

J Psychiatr Res 2021 May 27;140:22-29. Epub 2021 May 27.

Anxiety Disorders Program (PROTAN), Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, RS, Brazil; Graduate Program in Psychiatry and Behavioral Sciences, School of Medicine, Universidade Federal Do Rio Grande Do Sul (UFRGS), Porto Alegre, RS, Brazil. Electronic address:

Background: Generalized anxiety disorder (GAD) is one of the most prevalent anxiety disorders but the least successfully treated. The search for accessible clinical, psychological and biological markers is crucial for developing more effective and personalized interventions.

Aims: To evaluate if changes in heart rate variability (HRV) between rest and stress conditions before interventions could predict improvement in emotional interference (EI) in a cognitive task after three different treatment modalities in patients with GAD. Read More

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Single-shot quantitative phase imaging as an extension of differential interference contrast microscopy.

Genes Cells 2021 Jun 4. Epub 2021 Jun 4.

Central Research Laboratory, Hamamatsu Photonics K.K, 5000 Hirakuchi, Hamakita-ku, Hamamatsu, Shizuoka, 434-8601, Japan.

Various studies have been conducted to obtain quantitative phase information based on differential interference contrast (DIC) microscopy. As one such attempt, we propose in this study a single-shot quantitative phase imaging (QPI) method by combining two developments. First, an add-on optical system to a commercialized DIC microscope was developed to perform quantitative phase gradient imaging (QPGI) with single image acquisition using a polarization camera. Read More

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Positive Psychosocial Factors and Oxytocin in the Ovarian Tumor Microenvironment.

Psychosom Med 2021 Jun;83(5):417-422

From the Department of Psychological and Brain Sciences (Cuneo, Schrepf, Lutgendorf), University of Iowa, Iowa City, Iowa; Department of Psychology (Szeto, McCabe), University of Miami, Coral Gables, Florida; Division of Gynecologic Oncology, Department of Obstetrics and Gynecology (Thaker), Washington University School of Medicine, St Louis, Missouri; Holden Comprehensive Cancer Center (Goodheart, Lutgendorf) and Division of Gynecologic Oncology, Department of Obstetrics and Gynecology (Goodheart, Lutgendorf), University of Iowa, Iowa City, Iowa; Department of Medicine, Division of Hematology/Oncology and Molecular Biology Institute, David Geffen School of Medicine (Cole), University of California, Los Angeles; Departments of Gynecologic Oncology, Cancer Biology and Center for RNA Interference and Noncoding RNA (Sood), University of Texas MD Anderson Cancer Center, Houston, Texas; and Diabetes Research Institute, Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Miller School of Medicine (Mendez), University of Miami, Coral Gables, Florida.

Objective: Clinical ovarian cancer research shows relationships between psychosocial factors and disease-promoting aspects of the stress response (e.g., norepinephrine and cortisol). Read More

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Monitoring and Managing Lorlatinib Adverse Events in the Portuguese Clinical Setting: A Position Paper.

Drug Saf 2021 Jun 3. Epub 2021 Jun 3.

Centro Hospitalar Universitário de São João, Porto, Portugal.

Rearrangements in the anaplastic lymphoma kinase (ALK) and proto-oncogene tyrosine-protein kinase ROS (ROS1) genes characterise two distinct molecular subsets of non-small cell lung cancer (NSCLC) tumours. Lorlatinib is a third-generation ALK/ROS1 tyrosine kinase inhibitor (TKI) shown to have systemic and intracranial activity in treatment-naive patients and in those who progressed on first- and second-generation TKIs. Despite being generally well tolerated, lorlatinib has a unique and challenging safety profile that includes hyperlipidaemia and central and peripheral nervous system adverse events (AEs). Read More

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Localized Induced Defenses Limit Gall Formation by Eriophyid Mite Against Invasive Lygodium microphyllum (Schizaeales: Lygodiaceae).

Environ Entomol 2021 Jun 3. Epub 2021 Jun 3.

USDA-ARS Invasive Plant Research Laboratory, 3225 College Avenue, Fort Lauderdale, FL 33314.

A potential barrier to the establishment of weed biological control agents is interference from other management tactics that induce plant defenses. Methods that suppress the weed such as feeding by other biological control agents or mechanical removal are especially disposed to inducing plant defenses and potentially limiting agent establishment. Here, we focused on the invasive weed Lygodium microphyllum (Cav. Read More

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Epigenetic Therapies for Heart Failure: Current Insights and Future Potential.

Vasc Health Risk Manag 2021 24;17:247-254. Epub 2021 May 24.

Department of Advanced Medical and Surgical Sciences (DAMSS), University of Campania "Luigi Vanvitelli", Naples, 80138, Italy.

Despite the current reductionist approach providing an optimal indication for diagnosis and treatment of patients with heart failure with reduced ejection fraction (HFrEF), there are no standard pharmacological therapies for heart failure with preserved ejection fraction (HFpEF). Although in its infancy in cardiovascular diseases, the epigenetic-based therapy ("epidrugs") is capturing the interest of physician community. In fact, an increasing number of controlled clinical trials is evaluating the putative beneficial effects of: 1) direct epigenetic-oriented drugs, eg, apabetalone, and 2) repurposed drugs with a possible indirect epigenetic interference, eg, metformin, statins, sodium glucose transporter inhibitors 2 (SGLT2i), and omega 3 polyunsaturated fatty acids (PUFAs) in both HFrEF and HFpEF, separately. Read More

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Mitochondria in epithelial ovarian carcinoma exhibit abnormal phenotypes and blunted associations with biobehavioral factors.

Sci Rep 2021 Jun 2;11(1):11595. Epub 2021 Jun 2.

Division of Behavioral Medicine, Department of Psychiatry, Columbia University Irving Medical Center, New York, NY, USA.

Malignant tumor cells exhibit mitochondrial alterations and are also influenced by biobehavioral processes, but the intersection of biobehavioral factors and mitochondria in malignant tumors remains unexplored. Here we examined multiple biochemical and molecular markers of mitochondrial content and function in benign tissue and in high-grade epithelial ovarian carcinoma (EOC) in parallel with exploratory analyses of biobehavioral factors. First, analysis of a publicly-available database (n = 1435) showed that gene expression of specific mitochondrial proteins in EOC is associated with survival. Read More

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