生物物理学期刊(英文)最新文献

{"title":"Intrinsic Noise Monitoring of Complex Systems","authors":"O. Szász, G. Szigeti, A. Szász","doi":"10.4236/OJBIPHY.2017.74015","DOIUrl":"https://doi.org/10.4236/OJBIPHY.2017.74015","url":null,"abstract":"The power-density function of the noise spectrum of open and complex systems changes by the power of frequency. We show that the fluctuation origin and the noise-powered description are equivalent to describe the colored noise power density. Based on this, we introduce a scale-independent invariant for monitoring the dynamics of the complex system. The monitoring of the noise spectrum of the system specifies the forecast of failure, the timing of desired regular corrections and/or the assessed operation life of the system, indicating the possible faults before it happens, predicting deterioration like wear/tear, fatigue in the still properly working system. These considerations are highly applicable to living systems and their preventive care.","PeriodicalId":59528,"journal":{"name":"生物物理学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42265390","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":"Contribution of Myocardial Perfusion’s Tomoscintigraphy in the Management of Coronarian Disease in Senegal: About 42 Cases","authors":"B. Ndong, G. Mbaye, E. Bathily, O. Diop, A. Diop, L. Diouf, A. Mbaye, R. S. Senghor, M. Soumboundou, A. Djiboune, P. M. Sy, N. Badji, A. Dia, M. S. Djigo, M. Mbodj, O. Ndoye, M. Diarra, A. Kane, S. Seck-gassama","doi":"10.4236/OJBIPHY.2017.74013","DOIUrl":"https://doi.org/10.4236/OJBIPHY.2017.74013","url":null,"abstract":"The aim of the study was to evaluate the contribution to moscintigraphy of \u0000myocardial perfusion (TSMP) with 99mTc-sestamibi in the management of \u0000suspected or known coronary patients’s population. It included 42 patients \u0000with an average age of 57.02 ± 9.77 years with extremes ranging from 36 to 77 \u0000years. The pre-test probability in 38 patients was high in 7 patients (18.42%), \u0000intermediate in 29 patients (76.31%) and low in 2 patients (5.26%). Patients \u0000with a high pre-test probability had a positive scintigraphy. Among the 26 \u0000patients who underwent transthoracic ultrasound (TTU), 10 with normal \u0000kinetics on trans-thoracic ultrasound (TTU) had positive scintigraphy. For 16 \u0000patients with TTU abnormalities, 6 had negative scintigraphy and 10 had \u0000positive scintigraphy. The TSMP was positive for 28 patients (66.66%). Among \u0000these patients, 16 had pure ischemia, 57.14% (16/28), 7 pure necrosis (25%), \u0000and 5 both necrosis and ischemia. Myocardial perfusion scintigraphy remains \u0000a very contributory consideration in the management of coronary disease. \u0000This is synchronized with the electrocardiogram (ECG) and is an important \u0000diagnostic and prognostic tool for coronary artery disease. It also provides a \u0000good indication of coronary angiography.","PeriodicalId":59528,"journal":{"name":"生物物理学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46650235","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":"On the Self-Similarity in Biological Processes","authors":"O. Szász, G. Szigeti, A. Szász","doi":"10.4236/OJBIPHY.2017.74014","DOIUrl":"https://doi.org/10.4236/OJBIPHY.2017.74014","url":null,"abstract":"We show that the processes described by Avrami functions are self-similar. A comparative function characterizes a self-similar process by a certain Avrami exponent. We define the self-similar categories of some well-known biological processes. The method to determine the Avrami exponent by choosing the comparative function is demonstrated on the diffusion model of the growth of nuclei. We generalize the results.","PeriodicalId":59528,"journal":{"name":"生物物理学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45808327","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":"Energy Absorption by the Membrane Rafts in the Modulated Electro-Hyperthermia (mEHT)","authors":"Edina Papp, T. Vancsik, É. Kiss, O. Szász","doi":"10.4236/OJBIPHY.2017.74016","DOIUrl":"https://doi.org/10.4236/OJBIPHY.2017.74016","url":null,"abstract":"Aim: Heating by nanoparticles, which are located in the tissue to be treated, is a well-recognized method in hyperthermic oncology. Our objective is to investigate selective, nanoscopic heating without concentrating extra artificial nanoparticles. We have in silico calculation to study the heating of the transmembrane protein clusters (rafts) on cell-membrane. The transmembrane protein domains have significantly higher dielectric constant than their lipid neighborhood in the membrane. This difference causes a local gradient in the Specific Absorption Rate (SAR), which could be a factor of heating of the membranes locally, as well as exciting the receptors for various signal transduction in the cells. We suppose that this process determines the observed cellular effects of modulated electro-hyperthermia (mEHT, trade-name: oncothermia). Materials and Methods: In silico models with highly specialized software (Computer Simulation Technology (CST), Darmstadt, Germany) were performed visualizing the selectivity for the membrane domains. Local raft models were created to simulate the electromagnetic (EM) effect of a 13.56 MHz excitation between two perfect electrical conductor plates, simulating the equipotential conditions of the sides of the membrane in the vicinity of the raft. The simulations were performed with near-field (EQS) solver of CST. The electric field, current density, and electric loss density were monitored by the simulations. The applied material properties and parameters refer to the recent literature. Results: In silico models show ten times higher energy-absorption of the transmembrane domains than that of its lipid-membrane surrounding, and intra- and extracellular neighborhood. Depending on the size, orientation, and location of the membrane rafts, the value of SAR varies, but we use only two simplified models to see the absorption properties. Taking into account the characteristics of the EM field effects we showed that the selective energy-absorption increased further by the cell-cell interactions. The model-calculation could confirm the opportunity of the local membrane heating. Conclusion: Our results indicate the heating in nanoscopic range with energy-absorption by the transmembrane proteins. The heated protein-clusters (membrane rafts) are used the same way as the artificial nanoparticles, while these absorbers are natural parts of the biological system.","PeriodicalId":59528,"journal":{"name":"生物物理学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44444563","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":"Heating Preciosity—Trends in Modern Oncological Hyperthermia","authors":"O. Szász, M. Szász, C. Minnaar, A. Szász","doi":"10.4236/OJBIPHY.2017.73010","DOIUrl":"https://doi.org/10.4236/OJBIPHY.2017.73010","url":null,"abstract":"The use of hyperthermia as a treatment in oncology is a common topic for debate. Some researchers expect a breakthrough in oncological treatments with hyperthermia, whereas others have disregarded the method. Serious questions concerning hyperthermia have arisen. Should homogeneous (isothermal) or heterogeneous (selective) heating being used? When we use selective heating (heterogeneity), should the entire tumour be targeted or should the malignant cells be individually selected? Does the mechanism involve thermal cell death or thermally-assisted cell death? Is the goal necrosis or apoptosis? Is hyperthermia safe as a monotherapy or does it have to be combined with conventional treatments? When the selection is local, how do we act on disseminated cells that represent a high risk of life threatening metastases? When local heating is the focus, how should it be carried out with measured and controlled? Our objective is to show how precise, selective heat transfer is necessary to remove malignant cells and, consequently, how hyperthermia as part of the immune-oncology can change the game in this promising field of oncological therapies.","PeriodicalId":59528,"journal":{"name":"生物物理学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46000386","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-Thermal Radio Frequency Stimulation Inhibits the Tryptophan Synthase Beta Subunit in the Algae Chlamydomonas reinhardtii","authors":"B. M. Butters, G. Vogeli, Xavier A. Figueroa","doi":"10.4236/OJBIPHY.2017.73007","DOIUrl":"https://doi.org/10.4236/OJBIPHY.2017.73007","url":null,"abstract":"To demonstrate the ability of the Nativis signal transduction technology (Butters et al. 2014) to modulate the expression of algae mRNA and protein, we tested if we can alter specific enzyme levels in Chlamydomonas reinhardtii. We inhibited the synthesis of the enzyme tryptophan synthase beta subunit (MAA7) by applying the signal derived from a published siRNA (Zhao et al. 2009). With lower levels of MAA7, Chlamydomonas reinhardtii can grow in the presence of the prodrug 5-Fluoroindole (5-FI), because less 5-Fluoroin-dole can be converted to the toxic 5-Fluoro-L-tryptophan (5-FT). We find a 24% (±5%) increase of growth with the signal versus no signal. To see if that effect was due to the reduction of the amount of mRNA encoding MAA7, we used Real-Time Quantitative PCR (RT-QPCR) to measure the levels of MAA7 mRNA. To normalize the MAA7 mRNA level, we compared them to the levels of a mRNA that is not affected by the signal (G protein beta subunit-like polypeptide, Cblp). Two conditions increase the effectiveness of the signal. One can either treat the cell cultures during the logarithmic growth phase (starting the cultures at density of 0.104 OD at 750 nm). Or one can treat the cultures at a later stage of the logarithmic growth, but treating them for a longer time (8.7% versus 3.5% of the culture time). Under these conditions we found around a 50% decrease in the mRNA levels for MAA7. Treating the cultures at the earlier growth phase or at a later growth phase is less effective, with only a 20% effect.","PeriodicalId":59528,"journal":{"name":"生物物理学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44585112","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":"Quantifying Biofilm Formation of Sinorhizobium meliloti Bacterial Strains in Microfluidic Platforms by Measuring the Diffusion Coefficient of Polystyrene Beads","authors":"Chengcheng Cheng, Yijun Dong, M. Dorian, F. Kamili, Effrosyni Seitaridou","doi":"10.4236/OJBIPHY.2017.73012","DOIUrl":"https://doi.org/10.4236/OJBIPHY.2017.73012","url":null,"abstract":"Though the majority of bacteria can form structured communities known as biofilms, mutations can cause bacterial strains to vary in their ability to form a biofilm. In this study, the apparent diffusion coefficient of polystyrene microspheres 0.29 μm in diameter, which were executing Brownian motion inside bacterial colonies, was used as a quantitative parameter of the ability of a strain to form a biofilm and of the biofilm development. The study was performed using five Sinorhizobium meliloti strains, the biofilm-forming strains Rm8530 expR+, Rm8530 exoY, and Rm9034 expG, and the non-biofilm forming strains Rm1021 and Rm9030-2 expA1. The green fluorescent beads were placed with each strain in a separate channel of a microfluidic device. Thus, as the bacterial colonies grew under identical conditions over a 4-day period, the motion of the fluorescent microspheres was recorded and the diffusion coefficients were measured every 24 hours via particle tracking algorithms. It was found that each strain displayed a unique pattern of change in diffusion coefficient over time. Also, for a given biofilm-forming strain, there was a clear correlation between the value of the diffusion coefficient and the appearance and motility of the bacterial community. Thus, the diffusion coefficient can be used to identify different S. meliloti strains, and for the biofilm-forming strains, it is also a quantitative indicator of the stage of biofilm development.","PeriodicalId":59528,"journal":{"name":"生物物理学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42068869","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 Effects of Tissue Regenerative Status on Hormesis in Dogs Irradiated during Their Lifespan","authors":"A. N. Shoutko, L. P. Ekimova","doi":"10.4236/OJBIPHY.2017.73009","DOIUrl":"https://doi.org/10.4236/OJBIPHY.2017.73009","url":null,"abstract":"The goal of this study was to evaluate the influence of natural variation in the regenerative status of dog tissues on the signs of hormesis, which are evident after total body exposure to low daily doses of external gamma radiation throughout the lifespan. Ninety beagle dogs of both sexes were irradiated with cobalt 60 at 0.003 Gy/day commencing 1 year after birth to death. Control (n = 169) and irradiated animals underwent whole-life clinical observation and autopsy, and were then retrospectively divided into two subgroups with (W) or without benign tumors or tumors of unknown nature (WO) that were clinically recorded on single days throughout the lifespan. Radiation hormesis was only detected in subgroup WO, which had life span (LS) of 10.7 years in the absence of radiation. The radiogenic prolongation of life to 11.8 years in the WO subgroup (p 0.05) was similar to that in the W control and irradiated W subgroups (11.8 and 11.5 years, respectively). The number of solid malignancies found upon autopsy of the control WO subgroup was less (39.5%) than that evident in the control W subgroup (60%). Compared to the irradiated W subgroup, irradiation of the WO subgroup was accompanied by a slight increase (1.14-fold) in the number of solid malignancies evident at autopsy and in the clinical signs of tissue atrophy and body weight loss (2.4-fold and 2.4-fold, respectively), but was accompanied by strong reductions in the extent of anemia and hemoblastoses (>10-fold for both). The data exclude the notion that radiation is associated with healing, but suggest that certain pathologies (e.g., hemoblastoses) may be substituted with other less dangerous somatic diseases in weaker animals only.","PeriodicalId":59528,"journal":{"name":"生物物理学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49496697","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 Effects of Irradiation of Peanut Grain by a Gamma-Ray Beam on Culture","authors":"G. Mbaye, M. Soumboundou, L. Diouf, B. Ndong, A. Djiboune, P. M. Sy, S. Dieng, M. Diouf, N. Diouf, A. Barry, M. Diarra","doi":"10.4236/OJBIPHY.2017.73008","DOIUrl":"https://doi.org/10.4236/OJBIPHY.2017.73008","url":null,"abstract":"The problems of agriculture in Senegal result in a low yield per hectare and poor seed quality contributing strongly to the decline in productivity. Mutagenesis by X- or Y-ray irradiation makes it possible to obtain genetic mutants necessary to improve production. It is in this context that we undertook this study to evaluate the effects induced on the cultivation of peanut seeds irradiated by X-rays at low doses applied in radiotherapy. X-ray irradiation of four (2, 3, 4, 5) lots of peanuts are performed with respectively 0.5, 1.5, 2 and 4 Gray using the cobalt 60 therapy device (Alcyon II). The seeding of the seeds and then the following-up of the crops during 35 days allowed us to study the parameters of germination, growth and yield. The results obtained after monitoring revealed that the irradiation did not have any significant impact on germination and would appear to temporarily inhibit the growth rate compared to the control batch. However, the decrease in weight of the harvested seeds can be explained by the absence of fertilizer during the cultivation.","PeriodicalId":59528,"journal":{"name":"生物物理学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45764523","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":"Two Small Molecules, ZCL278 and AZA197 Show Promise in Influencing Protein Interactions Involving the Ras-Related Protein Cell division cycle 42 [Cdc42] to Modulate Its Oncogenic Potential","authors":"D. Muhoza, P. Adams","doi":"10.4236/OJBIPHY.2017.73006","DOIUrl":"https://doi.org/10.4236/OJBIPHY.2017.73006","url":null,"abstract":"Cdc42 is a member of the Rho subfamily of Ras-related proteins, which were among the first oncogenic proteins to be identified as playing a sig-nificant role in a variety of cellular events [Barbacaid, 1987, Ann. Rev. Biochem]. Equally important, Protein-Protein Interactions [PPIs] involving Cdc42 continue to highlight the role of Ras-related proteins’ relevance to cancer. As these proteins have been considered incapable of being “druggable”, due to a perceived lack of binding surface[s] that are amenable to small molecule targeting, there remains limited development of therapies to tackle diseased states caused by Cdc42-stimulated hyperactivity. Thusly, it has become important to characterize molecular details, including dynamics, of PPIs involving Cdc42 that may lend themselves as potential targets for therapeutic approaches. Recently, two small molecules, ZCL278 and AZA197, have shown promise in directly targeting Cdc42 to influence PPIs that are capable of causing Cdc42-stimulated abnormal signaling. In this editorial, we highlight recent studies that show case how these two small molecules may influence Cdc42-protein interactions.","PeriodicalId":59528,"journal":{"name":"生物物理学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49177144","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}