生物物理学期刊(英文)最新文献

{"title":"Electrostatic Mechanism for Depolymerization-Based Poleward Force Generation at Kinetochores","authors":"L. J. Gagliardi, D. Shain","doi":"10.4236/OJBIPHY.2019.93014","DOIUrl":"https://doi.org/10.4236/OJBIPHY.2019.93014","url":null,"abstract":"Experiments implicating bound volume positive charge at kinetochores interacting with negative charge at microtubule free ends have prompted our calculation of the force at kinetochores for chromosome poleward motility during mitosis. We present here a corroborating force calculation between positively charged Hec1 tails in kinetochores and negatively charged C-termini at microtubule free ends. Based on experimentally-known charge magnitudes on Hec1 tails and C-termini at microtubule free ends, an ab initio calculation of poleward (tension) force per microtubule that falls within the experimental range is demonstrated. Due to the locations of C-termini charges on concave sides of splaying microtubules, this attractive force between subsets of low curvature splaying microtubule protofilaments C-termini eventually fails for subsets of protofilaments with more pronounced curvature, thus generating poleward force as microtubules depolymerize in a dynamic coupling, as observed experimentally. The mechanism by which kinetochores establish and maintain a dynamic coupling to microtubules for force production during the complex motions of mitosis remains elusive, and force generation at kinetochores has emerged as a signature problem in chromosome motility. In agreement with experiment, two separate calculations show that attractive electrostatic interactions over nanometer distances account for poleward chromosome forces at kinetochores.","PeriodicalId":59528,"journal":{"name":"生物物理学期刊(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46863681","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"DNA Sequencing: Current State and Prospects of Development","authors":"L. Gasparyan, I. Mazo, V. Simonyan, F. Gasparyan","doi":"10.4236/ojbiphy.2019.93013","DOIUrl":"https://doi.org/10.4236/ojbiphy.2019.93013","url":null,"abstract":"In this review, we collected and classified the stages of development of DNA sequencing methods and described its peculiarities. We pay attention mostly on solid-stead nanopore sequencing methods. Detailed discussion of the peculiarity and feasibility of the electrical methods of DNA sequencing is discussed. The detail analyses of the literature data, some critical considerations and the potential ways of optimization of DNA nanopore sequencing were presented.","PeriodicalId":59528,"journal":{"name":"生物物理学期刊(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46550010","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Non-Invasive Vibration-Stress of the Cirrhotic Liver of Patients Waiting for Transplantation Induces of Circulating CD133+ Stem Lymphocytes Committed Phenotypically toward the Liver","authors":"A. N. Shoutko, O. Gerasimova, V. Fedorov, F. K. Zherebtsov","doi":"10.4236/OJBIPHY.2019.93012","DOIUrl":"https://doi.org/10.4236/OJBIPHY.2019.93012","url":null,"abstract":"Background: Numerous studies of tissues’ regeneration have confessed the recovery of damaged liver by hematopoietic stem cells. The cells act not only by cell replacement in the target organ but also by delivering trophic factors that support endogenous liver regeneration. A little is known of how organ-derived signals recruit such committed cells into circulation. Objective: We investigated the roles of noninvasive mechanical percutaneous stress of cirrhotic human liver in numbers fluctuation of trophic, liver-specific alpha-fetoprotein-positive fraction of CD133-positive hematopoietic stem cells in lymphocytes of patients waiting for liver transplantation. Methods: To promote in blood the number of the alpha-fetoprotein-positive fraction of CD133-positive hematopoietic stem cells, committed to liver’ tissue, we activated mechanically the cirrhotic liver of patient by transcutaneous micro vibration received from skin-contacted electro-magnetic vibraphones generated mechanical pulses with amplitude 10 μm and smoothly changing frequency from 0.03 kHz to 18 kHz and back forth during one cycle duration 1 minute. The number of the alpha-fetoprotein-positive fraction of CD133-positive hematopoietic stem cells in lymphocytes of potential recipients was controlled by flow cytometry before and during daily sonication of skin area, which corresponds to liver projection on it. The 15 minutes cyclic sonication of the liver area performed daily for three weeks. Results: The sonication increased significantly averaged number of liver-specific alpha-fetoprotein-positive CD133-positive blood lymphocytes in 2 - 3 times compared to a base lane. The second similar sonication, the same zone after three weeks break showed differences with baseline, but it was statistically insignificant. The result was specifically related to the liver as it showed the control sonication of the backbone’s projection on the skin of a separate group of patients with cirrhotic liver from the waiting list. Conclusion: The stem cells committed to the liver recruit from the bone marrow into circulation, when organ mechanically stresses and secretes specific humoral signals to provoke of lymphopoiesis on host liver repair.","PeriodicalId":59528,"journal":{"name":"生物物理学期刊(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46975962","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of the Knowledge of CT Scan Prescribers on Patients’ Radioprotection in Senegal","authors":"S. M. Badiane, Pape Ibrahima Sane, C. Ndiaye, K. Gueye, O. Ndoye, K. M. Amoussou-Guénou, M. Mbodji","doi":"10.4236/OJBIPHY.2019.93015","DOIUrl":"https://doi.org/10.4236/OJBIPHY.2019.93015","url":null,"abstract":"Medical imaging has enabled major improvements in the medical care of the patient. However, some of these tests have the disadvantage of using ionizing radiation at low doses. Although the CT scan is a powerful diagnostic tool, it remains a highly radiant imaging modality. In addition, the risk of radiation-induced cancer associated with low X-ray doses is established by the American Phase 2 study BEIR VII, and preventive measures require a good level of knowledge on radioprotection by imaging test prescribers. In our study, we evaluated the knowledge of CT scan prescribers in Senegal regarding patient radioprotection. These prescribers consisted of physicians and surgeons without distinction of specialty. Our objective was to have the required data for optimizing CT prescriptions in compliance with the principles of radioprotection. Our work focused on a descriptive analytical study of 107 doctors who prescribed CT scan in public health institutions in Senegal. Our results revealed poor knowledge of doctors prescribing CT scan on induced radio risks, even though the majority of them stated that they took those risks into account. Our data were not isolated, they were applicable to similar studies conducted outside Senegal. In summary, our study led on the one hand to recommendations on initial and continuing training and on the other hand on organizational and regulatory considerations.","PeriodicalId":59528,"journal":{"name":"生物物理学期刊(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46926714","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Aging Leads to Over-Expression of Na+/K+ Pump Units in Liver and Na+/Ca2+ Exchangers in Brain Cortex","authors":"A. Nikoghosyan, Armenuhi Heqimyan, S. Ayrapetyan","doi":"10.4236/OJBIPHY.2019.93016","DOIUrl":"https://doi.org/10.4236/OJBIPHY.2019.93016","url":null,"abstract":"The metabolic controlling of tissue hydration is the fundamental parameter determining cell functional activity and its dysfunction is the common consequence of any cell pathology, including aging. The aim of the present study is to reveal the differences of age-dependent metabolic controlling of cell hydration of excitable tissue such as brain cortex and non-excitable tissues such as liver and spleen. For this purpose, the age-dependent sensitivity of cell hydration in excitable and non-excitablet issues is studied through depressing metabolic activity by cooling and its activation by supplying animals with distilled water, by inactivation of Na+/K+ pump and activation of Na+/Ca2+ exchange in the reverse mode. The obtained data bring us to the conclusion that the metabolic regulation of cell hydration in excitable tissue is realized by the activation of electrogenic Na+/K+ pump and Na+/Ca2+ exchange in the cell membrane and the formation of endogen water by mitochondrial activity, while the regulation of cell hydration in non-excitable tissue is carried out only by the activity of mitochondrial function. Aging leads to an over-expression of Na+/K+ pump units in liver and Na+/Ca2+ exchanger in brain cortex of rats.","PeriodicalId":59528,"journal":{"name":"生物物理学期刊(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42860576","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spectroscopic Characterization of the Interaction between Dopamine and Human Serum Albumin","authors":"I. M. Khalid, S. Sharkh, Husain Samamarh, Rania Alfaqeeh, M. Abuteir, Saqer M Darwish","doi":"10.4236/OJBIPHY.2019.92009","DOIUrl":"https://doi.org/10.4236/OJBIPHY.2019.92009","url":null,"abstract":"The interactions of HSA with DA have received great attention nowadays due to its significant effect in the biomedical field and overall health. The main aim of this work is to examine the interaction between DA and HSA at physiological conditions. Upon addition of DA to HSA, the fluorescence emission was quenched with quenching constant Kq = 1.32 × 109 L⋅mol−1⋅s−1 and the binding constant of DA with HSA is found to be K = 4.4 × 102 mainly indicating dynamic quenching. The HSA conformation was altered upon binding of DA to HSA with an increase in α-helix and a decrease in β-sheets suggesting unfolding of HSA secondary structure due to weak intermolecular interaction with HSA. In view of the evidence presented, it is important to understand the details of the interactions of HSA with DA which will be crucial in the design of new DA-inspired drugs and help revealing vital details to better understand the HSA’s role as a transporter for many drugs.","PeriodicalId":59528,"journal":{"name":"生物物理学期刊(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42950366","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mimicking Bone Chemical Composition Using Economical Materials for X-Ray Imaging Quality Assurance and Educational Purposes","authors":"Shyma M. Alkhateeb","doi":"10.4236/OJBIPHY.2019.92006","DOIUrl":"https://doi.org/10.4236/OJBIPHY.2019.92006","url":null,"abstract":"Imaging different bone sites for medical education requires the formation of bone-equivalent materials that mimic bone density. We investigated an economic imaging composition that characterizes bone density in imaging for quality assurance and educational purposes. Four different compositions were tested to reveal the best composition in simulating bone density in X-ray imaging. Hydrated lime was discovered to be the most suitable because it is durable (stiff and does not crumble), easy to source and process, and attenuates imaging X-rays enough to resemble real bone. Hydrated lime provides a significantly better phantom than the other combinations used.","PeriodicalId":59528,"journal":{"name":"生物物理学期刊(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43026749","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Intrinsic Self-Time of Biosystems","authors":"O. Szász, Peter Szigeti, A. Szász","doi":"10.4236/OJBIPHY.2019.92010","DOIUrl":"https://doi.org/10.4236/OJBIPHY.2019.92010","url":null,"abstract":"In biological systems, self-time differs from the physical time scale. Biological self-time is the characteristic of individual biosystems and invariantly describes the various dynamic processes in organisms. This biological invariance is introduced by using 2 basic theorems: Allometric scaling and the Weibull psychometric function. Our objective was to precisely describe the timing phenomenon in biosystems and provide a framework to further develop this analogy for other fields.","PeriodicalId":59528,"journal":{"name":"生物物理学期刊(英文)","volume":"9 1","pages":"131-145"},"PeriodicalIF":0.0,"publicationDate":"2019-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41899306","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bioelectromagnetic Paradigm of Cancer Treatment—Modulated Electro-Hyperthermia (mEHT)","authors":"O. Szász","doi":"10.4236/OJBIPHY.2019.92008","DOIUrl":"https://doi.org/10.4236/OJBIPHY.2019.92008","url":null,"abstract":"One of the most frequently applied bioelectromagnetic effects is the deep heating of the living species with EMF energy. Despite its long history, hyperthermia is a rarely applied oncotherapy. The reason is its controversial results and complicated control. One of the solutions is concentrating the electromagnetic energy nanoscopically on the parts of the malignant cells instead of heating up the complete tumor-mass. This approach is a kind of non-uniform energy absorption, providing energy liberation only in the selected regions. The energy-absorption of the malignant cells targets the membranes and creates a situation far from thermal equilibrium. The selection of the malignant cells is based on their decided differences from their healthy counterparts. The distinguishing parameters are the electromagnetic properties of the components of the malignant tissue which are the physiologic differences between the malignant cells and their healthy counterparts. The targets realize nano-range heating, using natural nanoclusters on the cell-membrane without artificially implementing them. This energy absorption generates consequent reactions, like programmed cell-death (apoptosis) continued by immunogenic cell-death involving extended immune reactions.  The applied radiofrequency current is amplitude modulated by time-fractal modulation pattern. The accurately matched impedance realizes the self-selective mechanisms which are promoted by stochastic resonances. This complex method is a new kind of hyperthermia, named mEHT. Our objective is to analyze the problems of the selective, non-equilibrium energy absorption, and present a solution by the electromagnetic mechanisms for an effective and controllable hyperthermia in oncology.","PeriodicalId":59528,"journal":{"name":"生物物理学期刊(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41487708","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Determination of the Optical Properties of Basal Cancer Using OCT System","authors":"S. S. Elwakeel, N. Almuslet, Yahia Badr Aldeen, K. M. Haroun","doi":"10.4236/ojbiphy.2019.92007","DOIUrl":"https://doi.org/10.4236/ojbiphy.2019.92007","url":null,"abstract":"The objective of this work is to determinate the optical properties of basal cancer cells using an optical coherence tomography (OCT). OCT system with He-Ne & diode laser was used to make interference pattern for the basal cancer, then the output was displayed by optical detector, information of an electrical signal passed to the digital oscilloscope to give the object information after Fourier transform processing for that signal, then PC and CCD were used to display FFT signal. Finally many steps were done to determine the optical properties for the basal cancer. The intensity of the signals was plotted against scanning distance; the obtained graphs were used to determine the penetration depth and absorption coefficient.","PeriodicalId":59528,"journal":{"name":"生物物理学期刊(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48106375","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}