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A method to deliver patterned electrical impulses to Schwann cells cultured on an artificial axon

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Neural Regeneration Research 2019年第6期14卷 1052-1059页

作者： Antonio merolli Yong mao gregory Voronin Joseph A.m.Steele N.Sanjeeva murthy Joachim Kohn New Jersey Center for Biomaterials Rutgers-The State University of New Jersey In Vivo Research Services Rutgers-The State University of New Jersey

Information from the brain travels back and forth along peripheral nerves in the form of electrical impulses generated by neurons and these impulses have repetitive patterns. Schwann cells in peripheral nerves receive molecular signals from axons to coordinate the process of myelination. There is evidence, however,that non-molecular signals play an important role in myelination in the form of patterned electrical impulses generated by neuronal activity. The role of patterned electrical impulses has been investigated in the literature using co-cultures of neurons and myelinating cells. The co-culturing method, however, prevents the uncoupling of the direct effect of patterned electrical impulses on myelinating cells from the indirect effect mediated by neurons. To uncouple these effects and focus on the direct response of Schwann cells,we developed an in vitro model where an electroconductive carbon fiber acts as an artificial axon. The fiber provides only the biophysical characteristics of an axon but does not contribute any molecular *** our "suspended wire model", the carbon fiber is suspended in a liquid media supported by a 3D printed scaffold. Patterned electrical impulses are generated by an Arduino 101 microcontroller. In this study, we describe the technology needed to set-up and eventually replicate this model. We also report on our initial in vitro tests where we were able to document the adherence and ensheath of human Schwann cells to the carbon fiber in the presence of patterned electrical impulses(hSCs were purchased from ScienCell Research Laboratories, Carlsbad, CA, USA; ScienCell fulfills the ethic requirements, including donor's consent). This technology will likely make feasible to investigate the response of Schwann cells to patterned electrical impulses in the future.

关键词： Schwann cell carbon fiber myelination electrical impulse artificial axon in vitro system Arduino microcontroller myelin basic protein

Surgical dilemmas in the management of colorectal liver metastases: the role of timing

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World Journal of Gastroenterology 2016年第21期22卷 4963-4965页

作者： Dimitrios Dimitroulis gregory Kouraklis Second Department of Surgery University of Athens Medical SchoolAthens GreeceLaiko Hospital11527 AthensGreece

Colorectal cancer(CRC) is an emerging health problem in the Western World both for its raising tendency as well as for its metastatic potential. Almost half of the patients with CRC will develop liver metastases during the course of their disease. The liver surgeon dealing with colorectal liver metastases faces several surgical dilemmas especially in the setting of the timing of operation. Synchronous resectable metastases should be treated prior or after induction chemotherapy? Furthermore in the case of synchronous colorectal liver metastases which organ should we first deal with, the liver or the colon? All these questions are set in the editorial and impulse for further investigation is put focusing on multidisciplinary approach and individualization of treatment modalities.

关键词： Colorectal cancer Chemotherapy Timing of surgery Colorectal liver metastases Liver first procedure multidisciplinary approach Individualized treatment strategies

Intra-procedural arrhythmia during cardiac catheterization: A systematic review of literature

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World Journal of Cardiology 2020年第6期12卷 269-284页

作者： Fatima A Shaik David J Slotwiner gregory m Gustafson Xuming Dai Division of Cardiology New York Presbyterian Queens HospitalFlushingNY 11355United States

BACKGROUND Cardiac catheterization is among the most performed medical procedures in the modern *** were sporadic reports indicating that cardiac arrhythmias are common during cardiac catheterization,and there are risks of developing serious and potentially life-threatening arrhythmias,such as sustained ventricular tachycardia(VT),ventricular fibrillation(VF)and high-grade conduction disturbances such as complete heart block(CHB),requiring immediate ***,there is lack of systematic overview of these *** To systematically review existing literature and gain better understanding of the incidence of cardiac arrhythmias during cardiac catheterization,and their impact on outcomes,as well as potential approaches to minimize this *** We applied a combination of terms potentially used in reports describing various cardiac arrhythmias during common cardiac catheterization procedures to systematically search Pubmed,EmBASE and Cochrane databases,as well as references of full-length *** During right heart catheterization(RHC),the incidence of atrial arrhythmias(premature atrial complexes,atrial fibrillation and flutter)was low(mias were usually transient and *** associated with the development of a new RBBB at a rate of 0.1%-0.3%in individuals with normal conduction system but up to 6.3%in individuals with pre-existing left bundle branch *** patients may require temporary pacing due to transient *** premature ventricular complexes or non-sustained VT are common during RHC(up to 20%of cases).Sustained ventricular arrhythmias(VT and/or VF)requiring either withdrawal of catheter or cardioversion occurred infrequently(1%-1.3%).During left heart catheterizations(LHC),the incidence of ventricular arrhythmias has declined significantly over the last few decades,from 1.1%historically to 0.1%*** overall reported rate of VT/VF in diagnostic LHC and coronary angiography is 0.8

关键词： Catheterization Coronary angiography Percutaneous coronary intervention Ventricular fibrillation Ventricular tachycardia

Laser capture microdissection and genetic analysis of carbon-labeled Kupffer cells

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World Journal of Gastroenterology 2009年第14期15卷 1708-1718页

作者： Stephan Gehring Edmond Sabo maryann E San martin Elizabeth m Dickson Chao-Wen Cheng Stephen H gregory Department of medicine Rhode Island Hospital and The Warren Alpert Medical School of Brown University Providence RI 02903 United States Department of Pathology Rhode Island Hospital and The Warren Alpert Medical School of Brown University Providence RI 02903 United States zentrum fur Kinder- und Jugendmedizin der Universitaitsmedizin der Johannes Gutenberg-Universitait 55101 Mainz Germany

AIm： To develop a method of labeling and microdissecting mouse Kupffer cells within an extraordinarily short period of time using laser capture microdissection （LCm）. mETHODS： Tissues are complex structures comprised of a heterogeneous population of interconnected cells. LCm offers a method of isolating a single cell type from specific regions of a tissue section. LCm is an essential approach used in conjunction with molecular analysis to study the functional interaction of cells in their native tissue environment. The process of labeling and acquiring cells by LCm prior to mRNA isolation can be elaborate, thereby subjecting the RNA to considerable degradation. Kupffer cell labeling is achieved by injecting India ink intravenously, thus circumventing the need for in vitro staining. The significance of this novel approach was validated using a cholestatic liver injury model. RESULTS： mRNA extracted from the microdissected cell population displayed marked increases in colonystimulating factor-1 receptor and Kupffer cell receptor message expression, which demonstrated Kupffer cell enrichment. Gene expression by Kupffer ceils derived from bile-duct-ligated, versus sham-operated, mice was compared. microarray analysis revealed a significant （2.5-fold, q value 〈 10） change in 493 genes. Based on this fold-change and a standardized Pubmed search, 10 genes were identified that were relevant to the ability of Kupffer cells to suppress liver injury. CONCLUSION; The methodology outlined herein provides an approach to isolating high quality RNA from Kupffer cells, without altering the tissue integrity.

关键词： Kupffer cells India ink Laser capturemicrodissection Bile duct ligation DNA microarray

Friction characteristics of confined inflatable structures

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Friction 2014年第4期2卷 365-390页

作者： Eduardo m.SOSA gregory J.THOmPSON Ever J.BARBERO Subhadeep GHOSH Kevin L.PEIL Department of Civil and Environmental Engineering West Virginia UniversityMorgantownWV 26506-6103USA Department of mechanical and Aerospace Engineering West Virginia UniversityMorgantownWV 26506-6106USA

The availability of high‐strength fabrics and progress in the development of large‐scale inflatable technology made possible the creation of temporary and quickly deployable structures for protection of underground *** structures are relatively lightweight and portable,and can maintain the required rigidity while in *** benefits have prompted the development of inflatable structures for use in confined spaces,such as tunnels and large‐diameter pipes to act as barriers for containing flooding with minimal infrastructure *** work presents experimental results obtained from the evaluation of frictional characteristics of the fabric material that constitute the structural membrane of confined inflatable structures developed for protection of underground transportation tunnels and other large *** tests at coupon level and slippage tests in a reduced‐scale inflatable structure were performed in order to evaluate the frictional characteristics of Vectran *** at coupon level were performed to determine the friction coefficient for different surface types and *** with the reduced‐scale inflatable structure contributed to the understanding of the friction characteristics at system level when subjected to different pressurization or depressurization sequences designed to induce *** results indicate that friction coefficient values at coupon level are about 29 percent higher than values derived from reduced‐scale tests.

关键词： friction fabric materials inflatable structures slippage Vectran

Simple glycolipids of microbes:Chemistry,biological activity and metabolic engineering

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Synthetic and Systems Biotechnology 2018年第1期3卷 3-19页

作者： Ahmad mohammad Abdel-mawgoud gregory Stephanopoulos Department of Chemical Engineering Massachusetts Institute of Technology77 Massachusetts Ave.CambridgeMA 02139USA

Glycosylated lipids(GLs)are added-value lipid derivatives of great *** their interesting surface activities that qualify many of them to act as excellent ecological detergents,they have diverse biological activities with promising biomedical and cosmeceutical ***,especially those of microbial origin,have interesting antimicrobial,anticancer,antiparasitic as well as immunomodulatory ***,GLs are hardly accessing the market because of their high cost of *** believe that experience of metabolic engineering(mE)of microbial lipids for biofuel production can now be harnessed towards a successful synthesis of microbial GLs for biomedical and other *** review presents chemical groups of bacterial and fungal GLs,their biological activities,their general biosynthetic pathways and an insight on mE strategies for their production.

关键词： Biosurfactant Glycolipids biosynthesis Glycosyl/acyl transferases Glycosides Physiological roles Lipid biotechnology

Engineering porous organic polymers for carbon dioxide capture

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Science China Chemistry 2017年第8期60卷 1007-1014页

作者： Ning Huang gregory Day Xinyu Yang Hannah Drake Hong-Cai Zhou Department of Chemistry Texas A＆M University College Station TX 77843 US

As atmospheric CO_2 levels rise, the development of physical or chemical adsorbents for CO_2 capture and separation is of great importance on the way towards a sustainable low-carbon future. Porous organic polymers are promising candidates for CO_2 capture materials owing to their structural flexibility, high surface area, and high stability. In this review, we highlight high-performance porous organic polymers for CO_2 capture and summarize the strategies to enhance CO_2 uptake and selectivity, such as increasing surface area, increasing interaction between porous organic polymers and CO_2, and pore surface functionalization.

关键词： porous organic polymers C02 capture nanomaterials post-synthesis polymer

Alzheimer’s Disease: A Washing machine on the Fritz

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Journal of Behavioral and Brain Science 2022年第4期12卷 131-163页

作者： James m. gregory Professor Emeritus Texas Tech University Lubbock TX USA

A mathematical model has been developed to numerically model the risk of developing Alzheimer’s disease and Chronic Traumatic Encephalopathy (CTE) as a person ages. The model was programmed in Excel to provide a working prototype computer simulation model. The model provides estimates of the cumulative risk of developing Alzheimer’s disease and CTE as age increases. A one-year step size was used. The model has two major parts: one predicts changes in slow-wave sleep as a person ages and the second component adjusts the flushing efficiency of waste products from the brain. The two components work together and interact to lower the flushing of waste components as age increases. The development of the model provides an overview of how the various factors work together that lead to the onset of Alzheimer’s disease and the associated CTE. Calibration of the coefficients in the model is based on published data sets presented in the literature. Further research and refinement of calibration coefficients should be explored.

关键词： Alzheimer’s Disease Sleep mathematical modeling Chronic Traumatic Encephalopathy CTE Aging Depression Amyloid β Tau

WASO: Why Does It Increase with Age?

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Journal of Behavioral and Brain Science 2022年第4期12卷 164-176页

作者： James m. gregory Professor Emeritus Texas Tech University Lubbock TX USA

Insomnia is a common sleep disorder, especially for seniors. WASO (time awake after sleep onset), a component of insomnia, tends to increase with age. There are also many variations in WASO for seniors. To better understand the nature of insomnia, an equation was developed to predict WASO using maximum oxygen uptake (VO2max) as a measure of fitness associated with aerobic exercise. Predictions from the equation matched measured values with an R2 = 0.98. The results were highly significant (p 2max as a function of age and relative fitness (a measure of aerobic fitness independent of age). The two equations were combined to predict WASO as a function of age, gender, and relative fitness. Based on these results, it appears that aerobic exercise to improve relative fitness can be used to reduce WASO. The WASO model explains the numerous reports of reduced WASO associated with long-term exercise programs. The model also explains why WASO increases with age and why high WASO values associate with early death.

关键词： WASO Time Awake Sleep Disorders Sleep Quality Aerobic Exercise