Advancing Small Satellite Electronics Heritage for Microfluidic Biological Experiments

Science.gov (United States)

White, Bruce; Mazmanian, Edward; Tapio, Eric

2016-01-01

DLR's Eu:CROPIS (Euglena and Combined Regenerative Organic-Food Production in Space) mission, launching in 2017, will carry multiple biological payloads into a sun-synchronous orbit, including NASA Ames' PowerCell experiment. PowerCell will attempt to characterize the viability of synthetic biology at micro-g, Lunar, and Martian gravity levels. PowerCell experiment requirements demand an electronic system similar to previous microfluidic biology payloads, but with an expanded feature set. As such, the system was based on PharmaSat (Diaz-Aguado et al. 2009), a previous successful biology payload from NASA Ames, and improved upon. Newer, more miniaturized electronics allow for greater capability with a lower part count and smaller size. Two identical PowerCell enclosures will fly. Each enclosure contains two separate and identical experiments with a 48-segment optical density measurement system, grow light system, microfluidic system for nutrient delivery and waste flushing, plus thermal control and environmental sensing/housekeeping including temperature, pressure, humidity, and acceleration. Electronics consist of a single Master PCB that interfaces to the spacecraft bus and regulates power and communication, plus LED, Detector, and Valve Manifold PCBs for each experiment. To facilitate ease of reuse on future missions, experiment electronics were designed to be compatible with a standard 3U small sat form factor and power bus, or to interface with a Master power/comm PCB for use in a larger satellite as in the case of PowerCell's flight on Eu:CROPIS.

Electron Bifurcation: Thermodynamics and Kinetics of Two-Electron Brokering in Biological Redox Chemistry

Energy Technology Data Exchange (ETDEWEB)

Zhang, Peng; Yuly, Jonathon L.; Lubner, Carolyn E. [National Renewable Energy Laboratory, Golden, Colorado 80401, United States; Mulder, David W. [National Renewable Energy Laboratory, Golden, Colorado 80401, United States; King, Paul W. [National Renewable Energy Laboratory, Golden, Colorado 80401, United States; Peters, John W. [Institute; Beratan, David N. [Department

2017-08-23

How can proteins drive two electrons from a redox active donor onto two acceptors at very different potentials and distances? And how can this transaction be conducted without dissipating very much energy or violating the laws of thermodynamics? Nature appears to have addressed these challenges by coupling thermodynamically uphill and downhill electron transfer reactions, using two-electron donor cofactors that have very different potentials for the removal of the first and second electron. Although electron bifurcation is carried out with near perfection from the standpoint of energy conservation and electron delivery yields, it is a biological energy transduction paradigm that has only come into focus recently. This Account provides an exegesis of the biophysical principles that underpin electron bifurcation.

Methanol as electron donor for thermophilic biological sulfate and sulfite reduction

OpenAIRE

Weijma, J.

2000-01-01

Sulfur oxyanions (e.g. sulfate, sulfite) can be removed from aqueous waste- and process streams by biological reduction with a suitable electron donor to sulfide, followed by partial chemical or biological oxidation of sulfide to elemental sulfur. The aim of the research described in this thesis was to make this biological process more broadly applicable for desulfurization of flue-gases and ground- and wastewaters by using the cheap chemical methanol as electron donor for the reduct...

Towards native-state imaging in biological context in the electron microscope

Science.gov (United States)

Weston, Anne E.; Armer, Hannah E. J.

2009-01-01

Modern cell biology is reliant on light and fluorescence microscopy for analysis of cells, tissues and protein localisation. However, these powerful techniques are ultimately limited in resolution by the wavelength of light. Electron microscopes offer much greater resolution due to the shorter effective wavelength of electrons, allowing direct imaging of sub-cellular architecture. The harsh environment of the electron microscope chamber and the properties of the electron beam have led to complex chemical and mechanical preparation techniques, which distance biological samples from their native state and complicate data interpretation. Here we describe recent advances in sample preparation and instrumentation, which push the boundaries of high-resolution imaging. Cryopreparation, cryoelectron microscopy and environmental scanning electron microscopy strive to image samples in near native state. Advances in correlative microscopy and markers enable high-resolution localisation of proteins. Innovation in microscope design has pushed the boundaries of resolution to atomic scale, whilst automatic acquisition of high-resolution electron microscopy data through large volumes is finally able to place ultrastructure in biological context. PMID:19916039

21 CFR 25.31 - Human drugs and biologics.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Human drugs and biologics. 25.31 Section 25.31 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ENVIRONMENTAL IMPACT CONSIDERATIONS Categorical Exclusions § 25.31 Human drugs and biologics. The classes of...

Generalized Fokker-Planck theory for electron and photon transport in biological tissues: application to radiotherapy.

Science.gov (United States)

Olbrant, Edgar; Frank, Martin

2010-12-01

In this paper, we study a deterministic method for particle transport in biological tissues. The method is specifically developed for dose calculations in cancer therapy and for radiological imaging. Generalized Fokker-Planck (GFP) theory [Leakeas and Larsen, Nucl. Sci. Eng. 137 (2001), pp. 236-250] has been developed to improve the Fokker-Planck (FP) equation in cases where scattering is forward-peaked and where there is a sufficient amount of large-angle scattering. We compare grid-based numerical solutions to FP and GFP in realistic medical applications. First, electron dose calculations in heterogeneous parts of the human body are performed. Therefore, accurate electron scattering cross sections are included and their incorporation into our model is extensively described. Second, we solve GFP approximations of the radiative transport equation to investigate reflectance and transmittance of light in biological tissues. All results are compared with either Monte Carlo or discrete-ordinates transport solutions.

Human biological rhythm in traditional Chinese medicine

Directory of Open Access Journals (Sweden)

Tianxing Zhang

2016-10-01

Full Text Available Traditional Chinese medicine (TCM has a comprehensive and thorough understanding of biological rhythm. Biological rhythm is an inherent connotation of “harmony between human and nature”, one of the thoughts in TCM. TCM discusses emphatically circadian rhythm, syzygial rhythm and seasonal rhythm, and particularly circadian and seasonal rhythms. Theories of Yin Yang and Five Elements are the principles and methods, with which TCM understands biological rhythms. Based on theories in TCM, biological rhythm in essence is a continuous variation of the human body state synchronized with natural rhythms, and theories of Yin Yang and Five Elements are both language tools to describe this continuous variation and theoretical tools for its investigation and application. The understandings of biological rhythm in TCM can be applied to etiology, health care, disease control and treatment. Many understandings in TCM have been confirmed by modern research and clinical reports, but there are still some pending issues. TCM is distinguished for its holistic viewpoint on biological rhythms.

Damage-free vibrational spectroscopy of biological materials in the electron microscope.

Science.gov (United States)

Rez, Peter; Aoki, Toshihiro; March, Katia; Gur, Dvir; Krivanek, Ondrej L; Dellby, Niklas; Lovejoy, Tracy C; Wolf, Sharon G; Cohen, Hagai

2016-03-10

Vibrational spectroscopy in the electron microscope would be transformative in the study of biological samples, provided that radiation damage could be prevented. However, electron beams typically create high-energy excitations that severely accelerate sample degradation. Here this major difficulty is overcome using an 'aloof' electron beam, positioned tens of nanometres away from the sample: high-energy excitations are suppressed, while vibrational modes of energies electron energy loss spectra from biogenic guanine crystals in their native state, resolving their characteristic C-H, N-H and C=O vibrational signatures with no observable radiation damage. The technique opens up the possibility of non-damaging compositional analyses of organic functional groups, including non-crystalline biological materials, at a spatial resolution of ∼10 nm, simultaneously combined with imaging in the electron microscope.

A national facility for biological cryo-electron microscopy

International Nuclear Information System (INIS)

Saibil, Helen R.; Grünewald, Kay; Stuart, David I.

2015-01-01

This review provides a brief update on the use of cryo-electron microscopy for integrated structural biology, along with an overview of the plans for the UK national facility for electron microscopy being built at the Diamond synchrotron. Three-dimensional electron microscopy is an enormously powerful tool for structural biologists. It is now able to provide an understanding of the molecular machinery of cells, disease processes and the actions of pathogenic organisms from atomic detail through to the cellular context. However, cutting-edge research in this field requires very substantial resources for equipment, infrastructure and expertise. Here, a brief overview is provided of the plans for a UK national three-dimensional electron-microscopy facility for integrated structural biology to enable internationally leading research on the machinery of life. State-of-the-art equipment operated with expert support will be provided, optimized for both atomic-level single-particle analysis of purified macromolecules and complexes and for tomography of cell sections. The access to and organization of the facility will be modelled on the highly successful macromolecular crystallography (MX) synchrotron beamlines, and will be embedded at the Diamond Light Source, facilitating the development of user-friendly workflows providing near-real-time experimental feedback

Dose-response relationship for chromosomal aberrations induced in human lymphocytes by 18 MeV electron beam irradiation

International Nuclear Information System (INIS)

Lashin, E.A.; Elaasar, E.M.; Moustafa, H.F.; Bakir, Y.Y.; Al Zenki, S.D.

1990-01-01

Dose response curves for lymphocyte chromosome aberration frequencies using X- and gamma radiation became an important and reliable indicator as biological dosimeter especially in radiation accidents and occupational over exposures. Nowadays electron beam therapy is frequently used for their advantages in cases of tumours under or near to the body surface. Dose-response curves for these electron beams are rarely published. Human peripheral blood lymphocytes were in vitro irradiated with various low and high doses (0.1 Gy to 4.9 Gy) of 18 MeV electron beams to utilize such a dose-response curve using chromosomal aberration frequencies as a biological indicator. Then we compared the biological curve with physically obtained curves normally used in planning for radiotherapy treatment. It is interesting to find a significant difference between both of them. The biological curve is generally higher in value and the aberrations induced by 93% of a dose is significantly higher and deeper in site than those aberrations induced by the 100% dose calculated physically. If the above observation is confirmed by detailed studies, it would be of importance to the radiotherapist to plan for isodose curves according to biological determinations. (author)

Biological applications of phase-contrast electron microscopy.

Science.gov (United States)

Nagayama, Kuniaki

2014-01-01

Here, I review the principles and applications of phase-contrast electron microscopy using phase plates. First, I develop the principle of phase contrast based on a minimal model of microscopy, introducing a double Fourier-transform process to mathematically formulate the image formation. Next, I explain four phase-contrast (PC) schemes, defocus PC, Zernike PC, Hilbert differential contrast, and schlieren optics, as image-filtering processes in the context of the minimal model, with particular emphases on the Zernike PC and corresponding Zernike phase plates. Finally, I review applications of Zernike PC cryo-electron microscopy to biological systems such as protein molecules, virus particles, and cells, including single-particle analysis to delineate three-dimensional (3D) structures of protein and virus particles and cryo-electron tomography to reconstruct 3D images of complex protein systems and cells.

Applications of Free Electron Lasers in Biology and Medicine

International Nuclear Information System (INIS)

Pelka, J.B.; Tybor, K.R.; Nietubyc, R.; Wrochna, G.

2010-01-01

The advent of free electron lasers opens up new opportunities to probe the dynamics of ultrafast processes and the structure of matter with unprecedented spatial and temporal resolution. New methods inaccessible with other known types of radiation sources can be developed, resulting in a breakthrough in deep understanding the fundamentals of life as well as in numerous medical and biological applications. In the present work the properties of free electron laser radiation that make the sources excellent for probing biological matter at an arbitrary wavelength, in a wide range of intensities and pulse durations are briefly discussed. A number of biophysical and biomedical applications of the new sources, currently considered among the most promising in the field, are presented. (author)

Transmission electron microscopy in molecular structural biology: A historical survey.

Science.gov (United States)

Harris, J Robin

2015-09-01

In this personal, historic account of macromolecular transmission electron microscopy (TEM), published data from the 1940s through to recent times is surveyed, within the context of the remarkable progress that has been achieved during this time period. The evolution of present day molecular structural biology is described in relation to the associated biological disciplines. The contribution of numerous electron microscope pioneers to the development of the subject is discussed. The principal techniques for TEM specimen preparation, thin sectioning, metal shadowing, negative staining and plunge-freezing (vitrification) of thin aqueous samples are described, with a selection of published images to emphasise the virtues of each method. The development of digital image analysis and 3D reconstruction is described in detail as applied to electron crystallography and reconstructions from helical structures, 2D membrane crystals as well as single particle 3D reconstruction of icosahedral viruses and macromolecules. The on-going development of new software, algorithms and approaches is highlighted before specific examples of the historical progress of the structural biology of proteins and viruses are presented. Copyright © 2014 Elsevier Inc. All rights reserved.

Electron Bifurcation: Thermodynamics and Kinetics of Two-Electron Brokering in Biological Redox Chemistry.

Science.gov (United States)

Zhang, Peng; Yuly, Jonathon L; Lubner, Carolyn E; Mulder, David W; King, Paul W; Peters, John W; Beratan, David N

2017-09-19

How can proteins drive two electrons from a redox active donor onto two acceptors at very different potentials and distances? And how can this transaction be conducted without dissipating very much energy or violating the laws of thermodynamics? Nature appears to have addressed these challenges by coupling thermodynamically uphill and downhill electron transfer reactions, using two-electron donor cofactors that have very different potentials for the removal of the first and second electron. Although electron bifurcation is carried out with near perfection from the standpoint of energy conservation and electron delivery yields, it is a biological energy transduction paradigm that has only come into focus recently. This Account provides an exegesis of the biophysical principles that underpin electron bifurcation. Remarkably, bifurcating electron transfer (ET) proteins typically send one electron uphill and one electron downhill by similar energies, such that the overall reaction is spontaneous, but not profligate. Electron bifurcation in the NADH-dependent reduced ferredoxin: NADP + oxidoreductase I (Nfn) is explored in detail here. Recent experimental progress in understanding the structure and function of Nfn allows us to dissect its workings in the framework of modern ET theory. The first electron that leaves the two-electron donor flavin (L-FAD) executes a positive free energy "uphill" reaction, and the departure of this electron switches on a second thermodynamically spontaneous ET reaction from the flavin along a second pathway that moves electrons in the opposite direction and at a very different potential. The singly reduced ET products formed from the bifurcating flavin are more than two nanometers distant from each other. In Nfn, the second electron to leave the flavin is much more reducing than the first: the potentials are said to be "crossed." The eventually reduced cofactors, NADH and ferredoxin in the case of Nfn, perform crucial downstream redox

Thyrotropin-releasing hormone controls mitochondrial biology in human epidermis.

Science.gov (United States)

Knuever, Jana; Poeggeler, Burkhard; Gáspár, Erzsébet; Klinger, Matthias; Hellwig-Burgel, Thomas; Hardenbicker, Celine; Tóth, Balázs I; Bíró, Tamás; Paus, Ralf

2012-03-01

Mitochondrial capacity and metabolic potential are under the control of hormones, such as thyroid hormones. The most proximal regulator of the hypothalamic-pituitary-thyroid (HPT) axis, TRH, is the key hypothalamic integrator of energy metabolism via its impact on thyroid hormone secretion. Here, we asked whether TRH directly modulates mitochondrial functions in normal, TRH-receptor-positive human epidermis. Organ-cultured human skin was treated with TRH (5-100 ng/ml) for 12-48 h. TRH significantly increased epidermal immunoreactivity for the mitochondria-selective subunit I of respiratory chain complex IV (MTCO1). This resulted from an increased MTCO1 transcription and protein synthesis and a stimulation of mitochondrial biogenesis as demonstrated by transmission electron microscopy and TRH-enhanced mitochondrial DNA synthesis. TRH also significantly stimulated the transcription of several other mitochondrial key genes (TFAM, HSP60, and BMAL1), including the master regulator of mitochondrial biogenesis (PGC-1α). TRH significantly enhanced mitochondrial complex I and IV enzyme activity and enhanced the oxygen consumption of human skin samples, which shows that the stimulated mitochondria are fully vital because the main source for cellular oxygen consumption is mitochondrial endoxidation. These findings identify TRH as a potent, novel neuroendocrine stimulator of mitochondrial activity and biogenesis in human epidermal keratinocytes in situ. Thus, human epidermis offers an excellent model for dissecting neuroendocrine controls of human mitochondrial biology under physiologically relevant conditions and for exploring corresponding clinical applications.

Methanol as electron donor for thermophilic biological sulfate and sulfite reduction

NARCIS (Netherlands)

Weijma, J.

2000-01-01

Sulfur oxyanions (e.g. sulfate, sulfite) can be removed from aqueous waste- and process streams by biological reduction with a suitable electron donor to sulfide, followed by partial chemical or biological oxidation of sulfide to elemental sulfur. The aim of the research described in this

Human development I: Twenty Fundamental Problems of Biology, Medicine, and Neuro-Psychology Related to Biological Information

Directory of Open Access Journals (Sweden)

Tyge Dahl Hermansen

2006-01-01

Full Text Available In a new series of papers, we address a number of unsolved problems in biology today. First of all, the unsolved enigma concerning how the differentiation from a single zygote to an adult individual happens has been object for severe research for decades. By uncovering a new holistic biological paradigm that introduces an energetic-informational interpretation of reality as a new way to experience biology, these papers will try to solve the problems connected with the events of biological ontogenesis involving a fractal hierarchy, from a single cell to the function of the human brain. The problems discussed are interpreted within the frames of a universe of roomy fractal structures containing energetic patterns that are able to deliver biological information. We think biological organization is guided by energetic changes on the level of quantum mechanics, interacting with the intention that again guides the energetic conformation of the fractal structures to gain disorders or healthiness. Furthermore, we introduce two new concepts: “metamorphous top down” evolution and “adult human metamorphosis”. The first is a new evolutionary theory involving metamorphosis as a main concept of evolution. The last is tightly linked to the evolutionary principle and explains how human self-recovery is governed. Other subjects of special interest that we shall look deeper into are the immunological self-nonself discrimination, the structure and function of the human brain, the etiology and salutogenesis of mental and somatic diseases, and the structure of the consciousness of a human being. We shall criticize Szentagothai’s model for the modulated structure of the human cerebral cortex and Jerne’s theory of the immunological regulatory anti-idiotypic network.

Source Identification of Human Biological Materials and Its Prospect in Forensic Science.

Science.gov (United States)

Zou, K N; Gui, C; Gao, Y; Yang, F; Zhou, H G

2016-06-01

Source identification of human biological materials in crime scene plays an important role in reconstructing the crime process. Searching specific genetic markers to identify the source of different human biological materials is the emphasis and difficulty of the research work of legal medical experts in recent years. This paper reviews the genetic markers which are used for identifying the source of human biological materials and studied widely, such as DNA methylation, mRNA, microRNA, microflora and protein, etc. By comparing the principles and methods of source identification of human biological materials using different kinds of genetic markers, different source of human biological material owns suitable marker types and can be identified by detecting single genetic marker or combined multiple genetic markers. Though there is no uniform standard and method for identifying the source of human biological materials in forensic laboratories at present, the research and development of a series of mature and reliable methods for distinguishing different human biological materials play the role as forensic evidence which will be the future development direction. Copyright© by the Editorial Department of Journal of Forensic Medicine.

Electronic cigarettes: human health effects

OpenAIRE

Callahan-Lyon, Priscilla

2014-01-01

Objective With the rapid increase in use of electronic nicotine delivery systems (ENDS), such as electronic cigarettes (e-cigarettes), users and non-users are exposed to the aerosol and product constituents. This is a review of published data on the human health effects of exposure to e-cigarettes and their components. Methods Literature searches were conducted through September 2013 using multiple electronic databases. Results Forty-four articles are included in this analysis. E-cigarette ae...

Synthetic Biology and Human Health: Potential Applications for Spaceflight

Science.gov (United States)

Karouia, Fathi; Carr, Christopher; Cai, Yizhi; Chen, Y.; Grenon, Marlene; Larios-Sanz, Maia; Jones, Jeffrey A.; Santos, Orlando

2011-01-01

Human space travelers experience a unique environment that affects homeostasis and physiologic adaptation. Spaceflight-related changes have been reported in the musculo-skeletal, cardiovascular, neurovestibular, endocrine, and immune systems. The spacecraft environment further subjects the traveler to noise and gravitational forces, as well as airborne chemical, microbiological contaminants, and radiation exposure. As humans prepare for longer duration missions effective countermeasures must be developed, verified, and implemented to ensure mission success. Over the past ten years, synthetic biology has opened new avenues for research and development in areas such as biological control, biomaterials, sustainable energy production, bioremediation, and biomedical therapies. The latter in particular is of great interest to the implementation of long-duration human spaceflight capabilities. This article discusses the effects of spaceflight on humans, and reviews current capabilities and potential needs associated with the health of the astronauts where synthetic biology could play an important role in the pursuit of space exploration.

The biology of human sexuality: evolution, ecology and physiology

Directory of Open Access Journals (Sweden)

PW Bateman

2006-09-01

Full Text Available Many evolutionary biologists argue that human sexual behaviour can be studied in exactly the same way as that of other species. Many sociologists argue that social influences effectively obscure, and are more important than, a reductionist biological approach to human sexual behaviour. Here,we authors attempt to provide a broad introduction to human sexual behaviour from a biological standpoint and to indicate where the ambiguous areas are. We outline the evolutionary selective pressures that are likely to have influenced human behaviour and mate choice in the past and in the present; ecological features that influence such things as degree of parental care and polygamy; and the associated physiology of human sexuality. Then they end with a discussion of �abnormal� sexuality.

Mass determination based on electron scattering in electron probe X-ray microanalysis of thin biological specimens

International Nuclear Information System (INIS)

Linders, P.W.J.

1984-01-01

This thesis describes the development of a method for mass determination of thin biological objects by quantitative electron microscopy. The practical realization of the mass determination consists of photographical recording with subsequent densitometry. (Auth.)

Biological effects of radiation human health and safety

International Nuclear Information System (INIS)

1977-05-01

The biological hazards of nuclear energy usage are a growing source of public concern. The medical profession may well be expected to contribute to public debate on the issue. This document, therefore, attempts a balanced review of the known and suspected human biological consequences of exposure to different types of ionizing radiation, emphasizing in particular the nuclear industry

The biology of human psychosexual differentiation.

Science.gov (United States)

Gooren, Louis

2006-11-01

Most attempts to identify biological underpinnings of gender identity and sexual orientation in humans have investigated effects of sex steroids, so pivotal in the differentiation of the genitalia, showing strong parallels between animals and the human. The information on humans is derived from the so-called 'experiments of nature', clinical entities with a lesser-than-normal androgen exposure in XY subjects and a higher than normal androgen exposure in XX subjects. Prenatal androgenization appears to predispose to a male gender identity development, but apparently not decisively since 40-50% of 46,XY intersexed children with a history of prenatal androgen exposure do not develop a male gender identity. Obviously, male-to-female transsexuals, with a normal androgen exposure prenatally (there is no serious evidence to the contrary) develop a female gender identity, through unknown biological mechanisms apparently overriding the effects of prenatal androgens. The latest studies in 46, XX subjects exposed to prenatal androgens show that prenatal androgenization of 46,XX fetuses leads to marked masculinization of later gender-related behavior but does not lead to gender confusion/dysphoria. The example of female-to-male transsexuals, without evidence of prenatal androgen exposure, indicates that a male gender identity can develop without a significant androgen stimulus. So we are far away from any comprehensive understanding of hormonal imprinting on gender identity formation. Brain studies in homosexuals have not held up in replication studies or are in need of replication in transsexuals. Genetic studies and the fraternal birth order hypothesis provide indications of familial clustering of homosexuality but in many homosexuals these genetic patterns cannot be identified. The biological explanations advanced for the birth order hypothesis lack any experimental support.

Correlation between biological activity and electron transferring of bovine liver catalase: Osmolytes effects

International Nuclear Information System (INIS)

Tehrani, H. Sepasi; Moosavi-Movahedi, A.A.; Ghourchian, H.

2013-01-01

Highlights: • Proline increases ET in Bovine Liver Catalase (BLC) whereas histidine decreases it. • Proline also increased the biological activity, whereas histidine decreased it. • Electron transferring and biological activity for BLC are directly correlated. • Proline causes favorable ET for BLC shown by positive E 1/2 (E°′) and negative ΔG. • Histidine makes ET unfavorable for BLC, manifested by E 1/2 (E°′) 0. -- Abstract: Catalase is a crucial antioxidant enzyme that protects life against detrimental effects of H 2 O 2 by disproportionating it into water and molecular oxygen. Effect of proline as a compatible and histidine as a non compatible osmolyte on the electron transferring and midpoint potential of catalase has been investigated. Proline increases the midpoint potential (ΔE m > 0), therefore causing the ΔG ET to be less positive and making the electron transfer reaction more facile whereas histidine decreases the E m (ΔE m ET , thereby rendering the electron transfer reaction less efficient. These results indicate the inhibitory effect of histidine evident by a −37% decrease in the cathodic peak current compared to 16% increase in the case of proline indicative of activation. The insight paves the tedious way towards our ultimate goal of elucidating a correlation between biological activity and electron transferring

The Value of Humans in the Biological Exploration of Space

Science.gov (United States)

Cockell, C. S.

2004-06-01

Regardless of the discovery of life on Mars, or of "no apparent life" on Mars, the questions that follow will provide a rich future for biological exploration. Extraordinary pattern recognition skills, decadal assimilation of data and experience, and rapid sample acquisition are just three of the characteristics that make humans the best means we have to explore the biological potential of Mars and other planetary surfaces. I make the case that instead of seeing robots as in conflict, or even in support, of human exploration activity, from the point of view of scientific data gathering and analysis, we should view humans as the most powerful robots we have, thus removing the separation that dogs discussions on the exploration of space. The narrow environmental requirements of humans, although imposing constraints on the life support systems required, is more than compensated for by their capabilities in biological exploration. I support this view with an example of the "Christmas present effect," a simple demonstration of human data and pattern recognition capabilities.

Metal-like transport in proteins: A new paradigm for biological electron transfer

Science.gov (United States)

Malvankar, Nikhil; Vargas, Madeline; Tuominen, Mark; Lovley, Derek

2012-02-01

Electron flow in biologically proteins generally occurs via tunneling or hopping and the possibility of electron delocalization has long been discounted. Here we report metal-like transport in protein nanofilaments, pili, of bacteria Geobacter sulfurreducens that challenges this long-standing belief [1]. Pili exhibit conductivities comparable to synthetic organic metallic nanostructures. The temperature, magnetic field and gate-voltage dependence of pili conductivity is akin to that of quasi-1D disordered metals, suggesting a metal-insulator transition. Magnetoresistance (MR) data provide evidence for quantum interference and weak localization at room temperature, as well as a temperature and field-induced crossover from negative to positive MR. Furthermore, pili can be doped with protons. Structural studies suggest the possibility of molecular pi stacking in pili, causing electron delocalization. Reducing the disorder increases the metallic nature of pili. These electronically functional proteins are a new class of electrically conductive biological proteins that can be used to generate future generation of inexpensive and environmentally-sustainable nanomaterials and nanolectronic devices such as transistors and supercapacitors. [1] Malvankar et al. Nature Nanotechnology, 6, 573-579 (2011)

Adventures in human population biology.

Science.gov (United States)

Baker, P T

1996-01-01

This article is a memoir of anthropologist Paul Baker's professional life. The introduction notes that the field of anthropology was altered by the impact of World War II when physical anthropologists provided vital information to the military. After the war, the GI bill supported the undergraduate and graduate studies of veterans, including Baker. After describing his academic training at the University of New Mexico and Harvard, Baker details his research training and field work in the desert for the US Climatic Research Laboratory and his work identifying the dead in Japan for the Quartermaster unit. Baker then traces his academic career at the Pennsylvania State University during which he directed two multidisciplinary research efforts for the International Biological Programme, one that sought to understand human adaptability at high altitude in Peru and another that studied migration and modernization in Samoa. Baker's last administrative positions were as staff consultant to the Man and the Biosphere (MAB) program and as chair of the US MAB committee. Baker retired from academic life at age 60 in 1987 and has devoted his time to reading and to helping organize professional associations in anthropology, especially those devoted to furthering internationally organized scientific efforts. Baker concludes this memoir by acknowledging the growth and development of the discipline of human population biology.

Electron Transfer in Chemistry and Biology – The Primary Events

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education; Volume 2; Issue 12. Electron Transfer in Chemistry and Biology – The Primary Events in Photosynthesis. V Krishnan. General Article Volume 2 Issue 12 December 1997 pp 77-86. Fulltext. Click here to view fulltext PDF. Permanent link:

Some examples of utilization of electron paramagnetic resonance in biology

International Nuclear Information System (INIS)

Bemski, G.

1982-10-01

A short outline of the fundamentals of electron paramagnetic resonance (EPR) is presented and is followed by examples of the application of EPR to biology. These include use of spin labels, as well as of ENDOR principally to problems of heme proteins, photosynthesis and lipids. (Author) [pt

Design of Functional Polyesters for Electronic and Biological Applications

OpenAIRE

Nelson, Ashley Marie

2015-01-01

Melt polymerization and novel monomers enabled the synthesis of polyesters for electronic and biological applications. Inspiration from nature and a passion for environmental preservation instigated an emphasis on the incorporation of renewable resources into polymeric materials. Critical analysis of current research surrounding bisphenol-A replacements and ioncontaining segmented polyurethanes aided in identifying benchmark polymers, including limitations, challenges, and future needs. Struc...

Radiation damage relative to transmission electron microscopy of biological specimens at low temperature: a review

International Nuclear Information System (INIS)

Glaeser, R.M.; Taylor, K.A.

1978-01-01

When biological specimens are irradiated by the electron beam in the electron microscope, the specimen structure is damaged as a result of molecular excitation, ionization, and subsequent chemical reactions. The radiation damage that occurs in the normal process of electron microscopy is known to present severe limitations for imaging high resolution detail in biological specimens. The question of radiation damage at low temperatures has therefore been investigated with the view in mind of reducing somewhat the rate at which damage occurs. The radiation damage protection found for small molecule (anhydrous) organic compounds is generally rather limited or even non-existent. However, large molecule, hydrated materials show as much as a 10-fold reduction at low temperature in the rate at which radiation damage occurs, relative to the damage rate at room temperature. In the case of hydrated specimens, therefore, low temperature electron microscopy offers an important advantage as part of the overall effort required in obtaining high resolution images of complex biological structures. (author)

Human enamel structure studied by high resolution electron microscopy

International Nuclear Information System (INIS)

Wen, S.L.

1989-01-01

Human enamel structural features are characterized by high resolution electron microscopy. The human enamel consists of polycrystals with a structure similar to Ca10(PO4)6(OH)2. This article describes the structural features of human enamel crystal at atomic and nanometer level. Besides the structural description, a great number of high resolution images are included. Research into the carious process in human enamel is very important for human beings. This article firstly describes the initiation of caries in enamel crystal at atomic and unit-cell level and secondly describes the further steps of caries with structural and chemical demineralization. The demineralization in fact, is the origin of caries in human enamel. The remineralization of carious areas in human enamel has drawn more and more attention as its potential application is realized. This process has been revealed by high resolution electron microscopy in detail in this article. On the other hand, the radiation effects on the structure of human enamel are also characterized by high resolution electron microscopy. In order to reveal this phenomenon clearly, a great number of electron micrographs have been shown, and a physical mechanism is proposed. 26 references

Systems biology of human metabolism - Defining the epithelial to mesenchymal transition and the activity of human gluconokinase

OpenAIRE

Rohatgi, Neha

2016-01-01

Studying human metabolism is crucial for the understanding of diseases and improvement of therapy as metabolic alterations are central to a number of human diseases. A variety of experimental disciplines, such as biochemistry, biophysics and systems biology are involved in the elucidation of metabolic pathways. The work presented in this thesis is divided into three main studies, which expand the knowledge of human metabolism using systems biology and biochemical techniques....

A short comparison of electron and proton transfer processes in biological systems

International Nuclear Information System (INIS)

Bertrand, Patrick

2005-01-01

The main differences between electron and proton transfers that take place in biological systems are examined. The relation between the distance dependence of the rate constant and the mass of the transferred particle is analyzed in detail. Differences between the two processes have important consequences at the experimental level, which are discussed. The various mechanisms that ensure the coupling between electron and proton transfers are briefly described

Practical guide to electronic resources in the humanities

CERN Document Server

Dubnjakovic, Ana

2010-01-01

From full-text article databases to digitized collections of primary source materials, newly emerging electronic resources have radically impacted how research in the humanities is conducted and discovered. This book, covering high-quality, up-to-date electronic resources for the humanities, is an easy-to-use annotated guide for the librarian, student, and scholar alike. It covers online databases, indexes, archives, and many other critical tools in key humanities disciplines including philosophy, religion, languages and literature, and performing and visual arts. Succinct overviews of key eme

Quantitative biological measurement in Transmission Electron Tomography

International Nuclear Information System (INIS)

Mantell, Judith M; Verkade, Paul; Arkill, Kenton P

2012-01-01

It has been known for some time that biological sections shrink in the transmission electron microscope from exposure to the electron beam. This phenomenon is especially important in Electron Tomography (ET). The effect on shrinkage of parameters such as embedding medium or sample type is less well understood. In addition anisotropic area shrinkage has largely been ignored. The intention of this study is to explore the shrinkage on a number of samples ranging in thickness from 200 nm to 500 nm. A protocol was developed to determine the shrinkage in area and thickness using the gold fiducials used in electron tomography. In brief: Using low dose philosophy on the section, a focus area was used prior to a separate virgin study area for a series of known exposures on a tilted sample. The shrinkage was determined by measurements on the gold beads from both sides of the section as determined by a confirmatory tomogram. It was found that the shrinkage in area (approximately to 90-95% of the original) and the thickness (approximately 65% of the original at most) agreed with pervious authors, but that a lmost all the shrinkage was in the first minute and that although the direction of the in-plane shrinkage (in x and y) was sometimes uneven the end result was consistent. It was observed, in general, that thinner samples showed more percentage shrinkage than thicker ones. In conclusion, if direct quantitative measurements are required then the protocol described should be used for all areas studied.

Quantitative biological measurement in Transmission Electron Tomography

Science.gov (United States)

Mantell, Judith M.; Verkade, Paul; Arkill, Kenton P.

2012-07-01

It has been known for some time that biological sections shrink in the transmission electron microscope from exposure to the electron beam. This phenomenon is especially important in Electron Tomography (ET). The effect on shrinkage of parameters such as embedding medium or sample type is less well understood. In addition anisotropic area shrinkage has largely been ignored. The intention of this study is to explore the shrinkage on a number of samples ranging in thickness from 200 nm to 500 nm. A protocol was developed to determine the shrinkage in area and thickness using the gold fiducials used in electron tomography. In brief: Using low dose philosophy on the section, a focus area was used prior to a separate virgin study area for a series of known exposures on a tilted sample. The shrinkage was determined by measurements on the gold beads from both sides of the section as determined by a confirmatory tomogram. It was found that the shrinkage in area (approximately to 90-95% of the original) and the thickness (approximately 65% of the original at most) agreed with pervious authors, but that a lmost all the shrinkage was in the first minute and that although the direction of the in-plane shrinkage (in x and y) was sometimes uneven the end result was consistent. It was observed, in general, that thinner samples showed more percentage shrinkage than thicker ones. In conclusion, if direct quantitative measurements are required then the protocol described should be used for all areas studied.

Human evolution, life history theory, and the end of biological reproduction.

Science.gov (United States)

Last, Cadell

2014-01-01

Throughout primate history there have been three major life history transitions towards increasingly delayed sexual maturation and biological reproduction, as well as towards extended life expectancy. Monkeys reproduce later and live longer than do prosimians, apes reproduce later and live longer than do monkeys, and humans reproduce later and live longer than do apes. These life history transitions are connected to increased encephalization. During the last life history transition from apes to humans, increased encephalization co-evolved with increased dependence on cultural knowledge for energy acquisition. This led to a dramatic pressure for more energy investment in growth over current biological reproduction. Since the industrial revolution socioeconomic development has led to even more energy being devoted to growth over current biological reproduction. I propose that this is the beginning of an ongoing fourth major primate life history transition towards completely delayed biological reproduction and an extension of the evolved human life expectancy. I argue that the only fundamental difference between this primate life history transition and previous life history transitions is that this transition is being driven solely by cultural evolution, which may suggest some deeper evolutionary transition away from biological evolution is already in the process of occurring.

Biological and social understanding of human nature: biopolitical dimension

Directory of Open Access Journals (Sweden)

S. K. Kostiuchkov

2014-07-01

Full Text Available This paper examines the position of the biopolitical nature of man as a biosocial being given supplies of both the two spheres of life – natural, biological and social. The necessity of understanding of human nature, which by definition are bio-social importance of the approach to the definition of man as an integral, binary-konnotovanoyi of the «social individual – a species» which is characterized by symmetrical opposition – upposition social and biological. It was found that the main task of modern political science, and in particular bio-political studies presented appeals to rethink the political picture of the world in order to predict the development of a new order or a new chaos. Understanding the formation of a new global civilization worldview is today one of the most important problems, which is connected with the main problem of the modern world – the task of preserving life on the planet. It is concluded that the contradictions of human nature – between the biological and the social, physical and spiritual, universal and the particular, natural and artificial, rational and emotional – in today’s conditions are extremely sharp. The said situation requires more in-depth scientific analysis of human nature, the study of the structural level as human biosocial system.

A histomorphometric and scanning electron microscopy study of human condylar cartilage and bone tissue changes in relation to age

DEFF Research Database (Denmark)

Paulsen, Hans Ulrik; Thomsen, J.S.; Hougen, Hans Petter

1999-01-01

To determine the possibility for adaptive growth in human condyles, quantifying the thickness of fibrocartilage and the constitution of cells with potential activity, the trabecular bone volume, and the structural parameter: marrow space star volume in a larger sample of human autopsy condyles....... EXPERIMENTAL SETTING AND DESIGN: A histomorphometric and scanning electron microscopic analysis of cartilage characteristics and bone remodelling activity. The Departments of Orthodontics and Cell Biology at Aarhus University, Denmark. An autopsy sample of condyles from 20 individuals, 18-31 years of age...

Modelling low energy electron and positron tracks in biologically relevant media

International Nuclear Information System (INIS)

Blanco, F.; Munoz, A.; Almeida, D.; Ferreira da Silva, F.; Limao-Vieira, P.; Fuss, M.C.; Sanz, A.G.; Garcia, G.

2013-01-01

This colloquium describes an approach to incorporate into radiation damage models the effect of low and intermediate energy (0-100 eV) electrons and positrons, slowing down in biologically relevant materials (water and representative biomolecules). The core of the modelling procedure is a C++ computing programme named 'Low Energy Particle Track Simulation (LEPTS)', which is compatible with available general purpose Monte Carlo packages. Input parameters are carefully selected from theoretical and experimental cross section data and energy loss distribution functions. Data sources used for this purpose are reviewed showing examples of electron and positron cross section and energy loss data for interactions with different media of increasing complexity: atoms, molecules, clusters and condense matter. Finally, we show how such a model can be used to develop an effective dosimetric tool at the molecular level (i.e. nanodosimetry). Recent experimental developments to study the fragmentation induced in biologically material by charge transfer from neutrals and negative ions are also included. (authors)

What is human in humans? Responses from biology, anthropology, and philosophy.

Science.gov (United States)

Bibeau, Gilles

2011-08-01

Genomics has brought biology, medicine, agriculture, psychology, anthropology, and even philosophy to a new threshold. In this new context, the question about "what is human in humans" may end up being answered by geneticists, specialists of technoscience, and owners of biotech companies. The author defends, in this article, the idea that humanity is at risk in our age of genetic engineering, biotechnologies, and market-geared genetic research; he also argues that the values at the very core of our postgenomic era bring to its peak the science-based ideology that has developed since the time of Galileo, Newton, Descartes, and Harvey; finally, it shows that the bioindustry has invented a new genomythology that goes against the scientific evidence produced by the research in human sciences in which life is interpreted as a language.

The relative biological effectiveness (RBE) of high-energy electrons, x-rays and Co-60 gamma-rays

International Nuclear Information System (INIS)

Kiyono, Kunihiro

1974-01-01

Linac (Mitsubishi-Shimizu 15 MeV medical linear accelerator) electron beams with actual generated energies of 8, 10, 12 and 15 MeV were compared with X-ray beams having energies of 8 and 10 MV. The RBE values were calculated from 50 percent hatch-ability (LD 50 ) in silk-worm embryos, 30-days lethality (LDsub(50/30)) in ddY mice, and mean lethal dose (Do) in cultured mouse YL cells or human FL cells. To estimate the RBE in clinical experiments, LRD (leukocyte reduction dose) value was calculated for each patient irradiated on the chest or lumbar vertebrae. It was concluded that there is little difference in practical significance between 8 to 10 MV X-rays and 8 to 15 MeV electrons, and that the biological effects of Linac radiations are about 90 to 100 percent of the effect of 60 Co gamma rays. The RBE values gradually decreased, contrary to the elevation of energy between 8 and 15 MeV for electrons and between 8 and 10 MV for X-rays. These values were compared with those of earlier reviews of work in this field, and were briefly discussed. (Evans, J.)

Human biological monitoring of occupational genotoxic exposures

DEFF Research Database (Denmark)

Knudsen, Lisbeth E.; Sorsa, M

1993-01-01

Human biological monitoring is a valuable tool for exposure assessment in groups of persons occupationally exposed to genotoxic agents. If the monitoring activity covers genetic material the term genetic monitoring is used. The methods used for genetic monitoring are either substance specific, e......) occupational exposure limit value of styrene in ambient air. The consideration of ethical issues in human genetic monitoring is an important but often overlooked aspect. This includes the scientific and preventional relevance of performing a test on individuals, pre- and post study information of donors...

Electron spin interactions in chemistry and biology fundamentals, methods, reactions mechanisms, magnetic phenomena, structure investigation

CERN Document Server

Likhtenshtein, Gertz

2016-01-01

This book presents the versatile and pivotal role of electron spin interactions in nature. It provides the background, methodologies and tools for basic areas related to spin interactions, such as spin chemistry and biology, electron transfer, light energy conversion, photochemistry, radical reactions, magneto-chemistry and magneto-biology. The book also includes an overview of designing advanced magnetic materials, optical and spintronic devices and photo catalysts. This monograph appeals to scientists and graduate students working in the areas related to spin interactions physics, biophysics, chemistry and chemical engineering.

Fundamental Technical Elements of Freeze-fracture/Freeze-etch in Biological Electron Microscopy

Science.gov (United States)

Freeze-fracture/freeze-etch describes a process whereby specimens, typically biological or nanomaterial in nature, are frozen, fractured, and replicated to generate a carbon/platinum "cast" intended for examination by transmission electron microscopy. Specimens are subjected to u...

Physical biology of human brain development

Directory of Open Access Journals (Sweden)

Silvia eBudday

2015-07-01

Full Text Available Neurodevelopment is a complex, dynamic process that involves a precisely orchestrated sequence of genetic, environmental, biochemical, and physical events. Developmental biology and genetics have shaped our understanding of the molecular and cellular mechanisms during neurodevelopment. Recent studies suggest that physical forces play a central role in translating these cellular mechanisms into the complex surface morphology of the human brain. However, the precise impact of neuronal differentiation, migration, and connection on the physical forces during cortical folding remains unknown. Here we review the cellular mechanisms of neurodevelopment with a view towards surface morphogenesis, pattern selection, and evolution of shape. We revisit cortical folding as the instability problem of constrained differential growth in a multi-layered system. To identify the contributing factors of differential growth, we map out the timeline of neurodevelopment in humans and highlight the cellular events associated with extreme radial and tangential expansion. We demonstrate how computational modeling of differential growth can bridge the scales-from phenomena on the cellular level towards form and function on the organ level-to make quantitative, personalized predictions. Physics-based models can quantify cortical stresses, identify critical folding conditions, rationalize pattern selection, and predict gyral wavelengths and gyrification indices. We illustrate that physical forces can explain cortical malformations as emergent properties of developmental disorders. Combining biology and physics holds promise to advance our understanding of human brain development and enable early diagnostics of cortical malformations with the ultimate goal to improve treatment of neurodevelopmental disorders including epilepsy, autism spectrum disorders, and schizophrenia.

Novelty, Stress, and Biological Roots in Human Market Behavior

Directory of Open Access Journals (Sweden)

Alexey Sarapultsev

2014-02-01

Full Text Available Although studies examining the biological roots of human behavior have been conducted since the seminal work Kahneman and Tversky, crises and panics have not disappeared. The frequent occurrence of various types of crises has led some economists to the conviction that financial markets occasionally praise irrational judgments and that market crashes cannot be avoided a priori (Sornette 2009; Smith 2004. From a biological point of view, human behaviors are essentially the same during crises accompanied by stock market crashes and during bubble growth when share prices exceed historic highs. During those periods, most market participants see something new for themselves, and this inevitably induces a stress response in them with accompanying changes in their endocrine profiles and motivations. The result is quantitative and qualitative changes in behavior (Zhukov 2007. An underestimation of the role of novelty as a stressor is the primary shortcoming of current approaches for market research. When developing a mathematical market model, it is necessary to account for the biologically determined diphasisms of human behavior in everyday low-stress conditions and in response to stressors. This is the only type of approach that will enable forecasts of market dynamics and investor behaviors under normal conditions as well as during bubbles and panics.

A national facility for biological cryo-electron microscopy.

Science.gov (United States)

Saibil, Helen R; Grünewald, Kay; Stuart, David I

2015-01-01

Three-dimensional electron microscopy is an enormously powerful tool for structural biologists. It is now able to provide an understanding of the molecular machinery of cells, disease processes and the actions of pathogenic organisms from atomic detail through to the cellular context. However, cutting-edge research in this field requires very substantial resources for equipment, infrastructure and expertise. Here, a brief overview is provided of the plans for a UK national three-dimensional electron-microscopy facility for integrated structural biology to enable internationally leading research on the machinery of life. State-of-the-art equipment operated with expert support will be provided, optimized for both atomic-level single-particle analysis of purified macromolecules and complexes and for tomography of cell sections. The access to and organization of the facility will be modelled on the highly successful macromolecular crystallography (MX) synchrotron beamlines, and will be embedded at the Diamond Light Source, facilitating the development of user-friendly workflows providing near-real-time experimental feedback.

Imaging and elemental mapping of biological specimens with a dual-EDS dedicated scanning transmission electron microscope

Science.gov (United States)

Wu, J.S.; Kim, A. M.; Bleher, R.; Myers, B.D.; Marvin, R. G.; Inada, H.; Nakamura, K.; Zhang, X.F.; Roth, E.; Li, S.Y.; Woodruff, T. K.; O'Halloran, T. V.; Dravid, Vinayak P.

2013-01-01

A dedicated analytical scanning transmission electron microscope (STEM) with dual energy dispersive spectroscopy (EDS) detectors has been designed for complementary high performance imaging as well as high sensitivity elemental analysis and mapping of biological structures. The performance of this new design, based on a Hitachi HD-2300A model, was evaluated using a variety of biological specimens. With three imaging detectors, both the surface and internal structure of cells can be examined simultaneously. The whole-cell elemental mapping, especially of heavier metal species that have low cross-section for electron energy loss spectroscopy (EELS), can be faithfully obtained. Optimization of STEM imaging conditions is applied to thick sections as well as thin sections of biological cells under low-dose conditions at room- and cryogenic temperatures. Such multimodal capabilities applied to soft/biological structures usher a new era for analytical studies in biological systems. PMID:23500508

Electron probe analysis of biological fluids: Possibilities and limitations

International Nuclear Information System (INIS)

Roinel, N.

1984-01-01

Physical methods of investigation have become essential to investigations at the cellular or subcellular level. Nuclear magnetic resonance is the most recent and striking example, since it is not only a tool for fundamental physicists and organic chemists, but also an extraordinary powerful imaging tool for physicians. The absorption properties of X rays were used immediately after their discovery to image the bones of skeletons. Later, X rays were also found to be extremely efficient in the measurement of the elemental content of microvolumes irradiated by electron probes. The electron probe analyzer (EPA) was immediately adopted by numerous laboratories of metallurgy, geology, and mineral sciences. In the last fifteen years, since the use of this instrument was suggested for liquid analysis, and a preparative technique was developed, the EPA has been used by an increasing number of biological laboratories for measuring the concentrations of the elements contained in subnanoliter volumes of biological fluids. The so-called microdroplet technique has become a routine laboratory method, the only one able to measure the concentrations of an unlimited number of elements in a single 0.1-nl sample. This explains its use in fields as various as renal, reproductive, digestive, and plant physiology, zoology, etc. Several review papers discuss these applications. The possibilities and limitations of the technique are discussed below

Electronic Textbook in Human Physiology.

Science.gov (United States)

Broering, Naomi C.; Lilienfield, Lawrence S.

1994-01-01

Describes the development of an electronic textbook in human physiology at the Georgetown University Medical Center Library that was designed to enhance learning and visualization through a prototype knowledge base of core instructional materials stored in digital format on Macintosh computers. The use of computers in the medical curriculum is…

Dynamical "in situ" observation of biological samples using variable pressure scanning electron microscope

Czech Academy of Sciences Publication Activity Database

Neděla, Vilém

2008-01-01

Roč. 126, - (2008), 012046:1-4 ISSN 1742-6588. [Electron Microscopy and Analysis Group Conference 2007 (EMAG 2007). Glasgow, 03.09.2007-07.09.2007] R&D Projects: GA ČR(CZ) GA102/05/0886; GA AV ČR KJB200650602 Institutional research plan: CEZ:AV0Z20650511 Keywords : biological sample * VP-SEM * dynamical experiments Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

Cloning humans? Biological, ethical, and social considerations.

Science.gov (United States)

Ayala, Francisco J

2015-07-21

There are, in mankind, two kinds of heredity: biological and cultural. Cultural inheritance makes possible for humans what no other organism can accomplish: the cumulative transmission of experience from generation to generation. In turn, cultural inheritance leads to cultural evolution, the prevailing mode of human adaptation. For the last few millennia, humans have been adapting the environments to their genes more often than their genes to the environments. Nevertheless, natural selection persists in modern humans, both as differential mortality and as differential fertility, although its intensity may decrease in the future. More than 2,000 human diseases and abnormalities have a genetic causation. Health care and the increasing feasibility of genetic therapy will, although slowly, augment the future incidence of hereditary ailments. Germ-line gene therapy could halt this increase, but at present, it is not technically feasible. The proposal to enhance the human genetic endowment by genetic cloning of eminent individuals is not warranted. Genomes can be cloned; individuals cannot. In the future, therapeutic cloning will bring enhanced possibilities for organ transplantation, nerve cells and tissue healing, and other health benefits.

[The policy of human biological reproduction in Brazil].

Science.gov (United States)

Oliveira, M A

1992-08-01

The author presents some of the historical determinations of the policies of human reproduction in Brazil, placing them among other social policies. She argues that reproductive profile of the social classes depends upon not only the biological reproduction, but also upon the work power.

The Human Genome Project: big science transforms biology and medicine.

Science.gov (United States)

Hood, Leroy; Rowen, Lee

2013-01-01

The Human Genome Project has transformed biology through its integrated big science approach to deciphering a reference human genome sequence along with the complete sequences of key model organisms. The project exemplifies the power, necessity and success of large, integrated, cross-disciplinary efforts - so-called 'big science' - directed towards complex major objectives. In this article, we discuss the ways in which this ambitious endeavor led to the development of novel technologies and analytical tools, and how it brought the expertise of engineers, computer scientists and mathematicians together with biologists. It established an open approach to data sharing and open-source software, thereby making the data resulting from the project accessible to all. The genome sequences of microbes, plants and animals have revolutionized many fields of science, including microbiology, virology, infectious disease and plant biology. Moreover, deeper knowledge of human sequence variation has begun to alter the practice of medicine. The Human Genome Project has inspired subsequent large-scale data acquisition initiatives such as the International HapMap Project, 1000 Genomes, and The Cancer Genome Atlas, as well as the recently announced Human Brain Project and the emerging Human Proteome Project.

RGB color coded images in scanning electron microscopy of biological surfaces

Czech Academy of Sciences Publication Activity Database

Kofroňová, Olga; Benada, Oldřich

2017-01-01

Roč. 61, č. 3 (2017), s. 349-352 ISSN 0001-723X R&D Projects: GA MŠk(CZ) LO1509; GA ČR(CZ) GA16-20229S Institutional support: RVO:61388971 Keywords : Biological surfaces * Color image s * Scanning electron microscopy Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 0.673, year: 2016

Human · mouse genome analysis and radiation biology. Proceedings

International Nuclear Information System (INIS)

Hori, Tada-aki

1994-03-01

This issue is the collection of the papers presented at the 25th NIRS symposium on Human, Mouse Genome Analysis and Radiation Biology. The 14 of the presented papers are indexed individually. (J.P.N.)

Human Biological Monitoring of Diisononyl Phthalate and Diisodecyl Phthalate: A Review

Directory of Open Access Journals (Sweden)

Gurusankar Saravanabhavan

2012-01-01

Full Text Available High molecular-weight phthalates, such as diisononyl phthalate (DINP, and diisodecyl phthalate (DIDP, are widely used as plasticizers in the manufacturing of polymers and consumer products. Human biological monitoring studies have employed the metabolites of DINP and DIDP as biomarkers to assess human exposure. In this review, we summarize and analyze publicly available scientific data on chemistry, metabolism, and excretion kinetics, of DINP and DIDP, to identify specific and sensitive metabolites. Human biological monitoring data on DINP and DIDP are scrutinised to assess the suitability of these metabolites as biomarkers of exposure. Results from studies carried out in animals and humans indicate that phthalates are metabolised rapidly and do not bioaccmulate. During Phase-I metabolism, ester hydrolysis of DINP and DIDP leads to the formation of hydrolytic monoesters. These primary metabolites undergo further oxidation reactions to produce secondary metabolites. Hence, the levels of secondary metabolites of DINP and DIDP in urine are found to be always higher than the primary metabolites. Results from human biological monitoring studies have shown that the secondary metabolites of DINP and DIDP in urine were detected in almost all tested samples, while the primary metabolites were detected in only about 10% of the samples. This indicates that the secondary metabolites are very sensitive biomarkers of DINP/DIDP exposure while primary metabolites are not. The NHANES data indicate that the median concentrations of MCIOP and MCINP (secondary metabolites of DINP and DIDP, resp. at a population level are about 5.1 μg/L and 2.7 μg/L, respectively. Moreover, the available biological monitoring data suggest that infants/children are exposed to higher levels of phthalates than adults.

Human Biological Monitoring of Diisononyl Phthalate and Diisodecyl Phthalate: A Review

International Nuclear Information System (INIS)

Saravanabhavan, G.; Murray, J.

2012-01-01

High molecular-weight phthalates, such as diisononyl phthalate (Din), and diisodecyl phthalate (DIDP), are widely used as plasticizers in the manufacturing of polymers and consumer products. Human biological monitoring studies have employed the metabolites of DINP and DIDP as bio markers to assess human exposure. In this review, we summarize and analyze publicly available scientific data on chemistry, metabolism, and excretion kinetics, of DINP and DIDP, to identify specific and sensitive metabolites. Human biological monitoring data on DINP and DIDP are scrutinised to assess the suitability of these metabolites as bio markers of exposure. Results from studies carried out in animals and humans indicate that phthalates are metabolised rapidly and do not bio accumulate. During Phase-I metabolism, ester hydrolysis of DINP and DIDP leads to the formation of hydrolytic monoesters. These primary metabolites undergo further oxidation reactions to produce secondary metabolites. Hence, the levels of secondary metabolites of DINP and DIDP in urine are found to be always higher than the primary metabolites. Results from human biological monitoring studies have shown that the secondary metabolites of DINP and DIDP in urine were detected in almost all tested samples, while the primary metabolites were detected in only about 10% of the samples. This indicates that the secondary metabolites are very sensitive bio markers of DINP/DIDP exposure while primary metabolites are not. The NHANES data indicate that the median concentrations of MCIOP and MCINP (secondary metabolites of DINP and DIDP, resp.) at a population level are about 5.1 μg/L and 2.7 μg/L, respectively. Moreover, the available biological monitoring data suggest that infants/children are exposed to higher levels of phthalates than adults.

Correlation between the dielectric properties and biological activities of human ex vivo hepatic tissue

International Nuclear Information System (INIS)

Wang, Hang; You, Fusheng; Fu, Feng; Dong, Xiuzhen; Shi, Xuetao; He, Yong; Yang, Min; Yan, Qingguo

2015-01-01

Dielectric properties are vital biophysical features of biological tissues, and biological activity is an index to ascertain the active state of tissues. This study investigated the potential correlation between the dielectric properties and biological activities of human hepatic tissue with prolonged ex vivo time through correlation and regression analyses. The dielectric properties of 26 cases of normal human hepatic tissue at 10 Hz to 100 MHz were measured from 15 min after isolation to 24 h at 37 °C with 90% humidity. Cell morphologies, including nucleus area (NA) and alteration rate of intercellular area (ICAR), were analyzed as indicators of biological activities. Conductivity, complex resistivity, and NA exhibited opposing changes 1 h after isolation. Relative permittivity and ex vivo time were not closely correlated (p > 0.05). The dielectric properties measured at low frequencies (i.e. <1 MHz) were more sensitive than those measured at high frequencies in reflecting the biological activity of ex vivo tissue. Highly significant correlations were found between conductivity, resistivity and the ex vivo time (p < 0.05) as well as conductivity and the cell morphology (p < 0.05). The findings indicated that establishing the correlation between the dielectric properties and biological activities of human hepatic tissue is of great significance for promoting the role of dielectric properties in biological science, particularly in human biology. (paper)

Imaging and elemental mapping of biological specimens with a dual-EDS dedicated scanning transmission electron microscope

Energy Technology Data Exchange (ETDEWEB)

Wu, J.S., E-mail: jinsong-wu@northwestern.edu [Northwestern University Atomic and Nanoscale Characterization Experimental (NUANCE) Center, Northwestern University, Evanston, IL 60208 (United States); Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208 (United States); Kim, A.M. [Department of Obstetrics and Gynecology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611 (United States); Chemistry of Life Processes Institute, Northwestern University, Evanston, IL 60208 (United States); Bleher, R. [Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208 (United States); Chemistry of Life Processes Institute, Northwestern University, Evanston, IL 60208 (United States); Myers, B.D. [Northwestern University Atomic and Nanoscale Characterization Experimental (NUANCE) Center, Northwestern University, Evanston, IL 60208 (United States); Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208 (United States); Marvin, R.G. [Department of Chemistry, Northwestern University, Evanston, IL 60208 (United States); Chemistry of Life Processes Institute, Northwestern University, Evanston, IL 60208 (United States); Inada, H.; Nakamura, K. [Hitachi High-Technologies Corporation, Ibaraki 312-8504 (Japan); Zhang, X.F. [Hitachi High Technologies America, Inc., 5960 Inglewood Drive, Pleasanton, California 94588 (United States); Roth, E. [Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208 (United States); Chemistry of Life Processes Institute, Northwestern University, Evanston, IL 60208 (United States); Li, S.Y. [Northwestern University Atomic and Nanoscale Characterization Experimental (NUANCE) Center, Northwestern University, Evanston, IL 60208 (United States); and others

2013-05-15

A dedicated analytical scanning transmission electron microscope (STEM) with dual energy dispersive spectroscopy (EDS) detectors has been designed for complementary high performance imaging as well as high sensitivity elemental analysis and mapping of biological structures. The performance of this new design, based on a Hitachi HD-2300A model, was evaluated using a variety of biological specimens. With three imaging detectors, both the surface and internal structure of cells can be examined simultaneously. The whole-cell elemental mapping, especially of heavier metal species that have low cross-section for electron energy loss spectroscopy (EELS), can be faithfully obtained. Optimization of STEM imaging conditions is applied to thick sections as well as thin sections of biological cells under low-dose conditions at room and cryogenic temperatures. Such multimodal capabilities applied to soft/biological structures usher a new era for analytical studies in biological systems. - Highlights: ► Applications of STEM in characterization of biological samples are demonstrated. ► Elemental analyses are performed by dual EDS and EELS. ► Both the surface and internal structure of cells can be studied simultaneously. ► The imaging contrast in low-dose cryo-STEM has been analyzed.

Imaging and elemental mapping of biological specimens with a dual-EDS dedicated scanning transmission electron microscope

International Nuclear Information System (INIS)

Wu, J.S.; Kim, A.M.; Bleher, R.; Myers, B.D.; Marvin, R.G.; Inada, H.; Nakamura, K.; Zhang, X.F.; Roth, E.; Li, S.Y.

2013-01-01

A dedicated analytical scanning transmission electron microscope (STEM) with dual energy dispersive spectroscopy (EDS) detectors has been designed for complementary high performance imaging as well as high sensitivity elemental analysis and mapping of biological structures. The performance of this new design, based on a Hitachi HD-2300A model, was evaluated using a variety of biological specimens. With three imaging detectors, both the surface and internal structure of cells can be examined simultaneously. The whole-cell elemental mapping, especially of heavier metal species that have low cross-section for electron energy loss spectroscopy (EELS), can be faithfully obtained. Optimization of STEM imaging conditions is applied to thick sections as well as thin sections of biological cells under low-dose conditions at room and cryogenic temperatures. Such multimodal capabilities applied to soft/biological structures usher a new era for analytical studies in biological systems. - Highlights: ► Applications of STEM in characterization of biological samples are demonstrated. ► Elemental analyses are performed by dual EDS and EELS. ► Both the surface and internal structure of cells can be studied simultaneously. ► The imaging contrast in low-dose cryo-STEM has been analyzed

Developing Humanities Collections in the Digital Age: Exploring Humanities Faculty Engagement with Electronic and Print Resources

Science.gov (United States)

Kachaluba, Sarah Buck; Brady, Jessica Evans; Critten, Jessica

2014-01-01

This article is based on quantitative and qualitative research examining humanities scholars' understandings of the advantages and disadvantages of print versus electronic information resources. It explores how humanities' faculty members at Florida State University (FSU) use print and electronic resources, as well as how they perceive these…

Analysis of Human Resources Management Strategy in China Electronic Commerce Enterprises

Science.gov (United States)

Shao, Fang

The paper discussed electronic-commerce's influence on enterprise human resources management, proposed and proved the human resources management strategy which electronic commerce enterprise should adopt from recruitment strategy to training strategy, keeping talent strategy and other ways.

Electron tomography study of isolated human centrioles.

Science.gov (United States)

Ibrahim, Rana; Messaoudi, Cédric; Chichon, Francisco Javier; Celati, Claude; Marco, Sergio

2009-01-01

Centrioles are components of the centrosome, which is present in most eukaryotic cells (from protozoa to mammals). They organize the microtubule skeleton during interphase and the mitotic spindle during cell division. In ciliate cells, centrioles form basal bodies that are involved in cellular motility. Despite their important roles in biology, the detailed structure of centrioles remains obscure. This work contributes to a more complete model of centriole structure. The authors used electron tomography of isolated centrosomes from the human lymphoblast KE37 to explore the details of subdistal appendages and centriole lumen organization in mother centrioles. Their results reveal that each of the nine subdistal appendages is composed of two halves (20 nm diameter each) fused in a 40 nm tip that extends 100 nm from where it anchors to microtubules. The centriole lumen is filled at the distal domain by a 45 nm periodic stack of rings. Each ring has a 30 nm diameter, is 15 nm thick, and appears to be tilted at 53 degrees perpendicular to the centriole axis. The rings are anchored to microtubules by arms. Based on their results, the authors propose a model of the mother centriole distal structure. Copyright 2008 Wiley-Liss, Inc.

Enhancing Biology Instruction with the Human Genome Project

Science.gov (United States)

Buxeda, Rosa J.; Moore-Russo, Deborah A.

2003-01-01

The Human Genome Project (HGP) is a recent scientific milestone that has received notable attention. This article shows how a biology course is using the HGP to enhance students' experiences by providing awareness of cutting edge research, with information on new emerging career options, and with opportunities to consider ethical questions raised…

NMR studies of transmembrane electron transport in human erythrocytes

International Nuclear Information System (INIS)

Kennett, E.C.; Bubb, W.A.; Kuchel, P.W.

2002-01-01

Full text: Electron transport systems exist in the plasma membranes of all cells. These systems appear to play a role in cell growth and proliferation, intracellular signalling, hormone responses, apoptotic events, cell defence and perhaps most importantly they enable the cell to respond to changes in the redox state of both the intra- and extracellular environments. Previously, 13 C NMR has been used to study transmembrane electron transport in human erythrocytes, specifically the reduction of extracellular 13 C-ferricyanide. NMR is a particularly useful tool for studying such systems as changes in the metabolic state of the cell can be observed concomitantly with extracellular reductase activity. We investigated the oxidation of extracellular NADH by human erythrocytes using 1 H and 31 P NMR spectroscopy. Recent results for glucose-starved human erythrocytes indicate that, under these conditions, extracellular NADH can be oxidised at the plasma membrane with the electron transfer across the membrane resulting in reduction of intracellular NAD + . The activity is inhibited by known trans-plasma membrane electron transport inhibitors (capsaicin and atebrin) and is unaffected by inhibition of the erythrocyte Band 3 anion transporter. These results suggest that electron import from extracellular NADH allows the cell to re-establish a reducing environment after the normal redox balance is disturbed

Small-scale laser based electron accelerators for biology and medicine: a comparative study of the biological effectiveness

Science.gov (United States)

Labate, Luca; Andreassi, Maria Grazia; Baffigi, Federica; Basta, Giuseppina; Bizzarri, Ranieri; Borghini, Andrea; Candiano, Giuliana C.; Casarino, Carlo; Cresci, Monica; Di Martino, Fabio; Fulgentini, Lorenzo; Ghetti, Francesco; Gilardi, Maria Carla; Giulietti, Antonio; Köster, Petra; Lenci, Francesco; Levato, Tadzio; Oishi, Yuji; Russo, Giorgio; Sgarbossa, Antonella; Traino, Claudio; Gizzi, Leonida A.

2013-05-01

Laser-driven electron accelerators based on the Laser Wakefield Acceleration process has entered a mature phase to be considered as alternative devices to conventional radiofrequency linear accelerators used in medical applications. Before entering the medical practice, however, deep studies of the radiobiological effects of such short bunches as the ones produced by laser-driven accelerators have to be performed. Here we report on the setup, characterization and first test of a small-scale laser accelerator for radiobiology experiments. A brief description of the experimental setup will be given at first, followed by an overview of the electron bunch characterization, in particular in terms of dose delivered to the samples. Finally, the first results from the irradiation of biological samples will be briefly discussed.

The irradiation action on human dental tissue by X-rays and electrons. A nanoindenter study

Energy Technology Data Exchange (ETDEWEB)

Fraenzel, Wolfgang [Halle-Wittenberg Univ., Halle (Germany). Dept. of Physics; Gerlach, Reinhard [Halle-Wittenberg Univ., Halle (Germany). Clinic of Radiation Therapy

2009-07-01

It is known that ionizing radiation is used in medicine for Roentgen diagnostics and for radiation therapy. The radiation interacts with matter, in particular with biological one, essentially by scattering, photoelectric effect, Compton effect and pair production. To what extent the biological material is changed thereby, depends on the type and the amount of radiation energy, on the dose and on the tissue constitution. In modern radiation therapy two different kinds of radiation are used: high energy X-rays and electron radiation. In the case of head-neck tumors the general practice is an irradiation with high energy X-rays with absorbed dose to water up to 70 Gy. Teeth destruction has been identified as a side effect during irradiation. In addition, damage to the salivary glands is often observed which leads to a decrease or even the complete loss of the salivary secretion (xerostomia). This study shows how the different energy and radiation types damage the tooth tissue. The effects of both, high X-ray energy and high energy electrons, on the mechanical properties hardness and elasticity of the human dental tissue are measured by the nanoindentation technique. We compare these results with the effect of the irradiation of low X-ray energy on the dental tissue. (orig.)

The irradiation action on human dental tissue by X-rays and electrons. A nanoindenter study

International Nuclear Information System (INIS)

Fraenzel, Wolfgang; Gerlach, Reinhard

2009-01-01

It is known that ionizing radiation is used in medicine for Roentgen diagnostics and for radiation therapy. The radiation interacts with matter, in particular with biological one, essentially by scattering, photoelectric effect, Compton effect and pair production. To what extent the biological material is changed thereby, depends on the type and the amount of radiation energy, on the dose and on the tissue constitution. In modern radiation therapy two different kinds of radiation are used: high energy X-rays and electron radiation. In the case of head-neck tumors the general practice is an irradiation with high energy X-rays with absorbed dose to water up to 70 Gy. Teeth destruction has been identified as a side effect during irradiation. In addition, damage to the salivary glands is often observed which leads to a decrease or even the complete loss of the salivary secretion (xerostomia). This study shows how the different energy and radiation types damage the tooth tissue. The effects of both, high X-ray energy and high energy electrons, on the mechanical properties hardness and elasticity of the human dental tissue are measured by the nanoindentation technique. We compare these results with the effect of the irradiation of low X-ray energy on the dental tissue. (orig.)

The Human Genome Project: Biology, Computers, and Privacy.

Science.gov (United States)

Cutter, Mary Ann G.; Drexler, Edward; Gottesman, Kay S.; Goulding, Philip G.; McCullough, Laurence B.; McInerney, Joseph D.; Micikas, Lynda B.; Mural, Richard J.; Murray, Jeffrey C.; Zola, John

This module, for high school teachers, is the second of two modules about the Human Genome Project (HGP) produced by the Biological Sciences Curriculum Study (BSCS). The first section of this module provides background information for teachers about the structure and objectives of the HGP, aspects of the science and technology that underlie the…

Cytotoxicity and mitogenicity assays with real-time and label-free monitoring of human granulosa cells with an impedance-based signal processing technology intergrating micro-electronics and cell biology.

Science.gov (United States)

Oktem, Ozgur; Bildik, Gamze; Senbabaoglu, Filiz; Lack, Nathan A; Akin, Nazli; Yakar, Feridun; Urman, Defne; Guzel, Yilmaz; Balaban, Basak; Iwase, Akira; Urman, Bulent

2016-04-01

A recently developed technology (xCelligence) integrating micro-electronics and cell biology allows real-time, uninterrupted and quantitative analysis of cell proliferation, viability and cytotoxicity by measuring the electrical impedance of the cell population in the wells without using any labeling agent. In this study we investigated if this system is a suitable model to analyze the effects of mitogenic (FSH) and cytotoxic (chemotherapy) agents with different toxicity profiles on human granulosa cells in comparison to conventional methods of assessing cell viability, DNA damage, apoptosis and steroidogenesis. The system generated the real-time growth curves of the cells, and determined their doubling times, mean cell indices and generated dose-response curves after exposure to cytotoxic and mitogenic stimuli. It accurately predicted the gonadotoxicity of the drugs and distinguished less toxic agents (5-FU and paclitaxel) from more toxic ones (cisplatin and cyclophosphamide). This platform can be a useful tool for specific end-point assays in reproductive toxicology. Copyright © 2015 Elsevier Inc. All rights reserved.

Electronic cigarettes: human health effects.

Science.gov (United States)

Callahan-Lyon, Priscilla

2014-05-01

With the rapid increase in use of electronic nicotine delivery systems (ENDS), such as electronic cigarettes (e-cigarettes), users and non-users are exposed to the aerosol and product constituents. This is a review of published data on the human health effects of exposure to e-cigarettes and their components. Literature searches were conducted through September 2013 using multiple electronic databases. Forty-four articles are included in this analysis. E-cigarette aerosols may contain propylene glycol, glycerol, flavourings, other chemicals and, usually, nicotine. Aerosolised propylene glycol and glycerol produce mouth and throat irritation and dry cough. No data on the effects of flavouring inhalation were identified. Data on short-term health effects are limited and there are no adequate data on long-term effects. Aerosol exposure may be associated with respiratory function impairment, and serum cotinine levels are similar to those in traditional cigarette smokers. The high nicotine concentrations of some products increase exposure risks for non-users, particularly children. The dangers of secondhand and thirdhand aerosol exposure have not been thoroughly evaluated. Scientific evidence regarding the human health effects of e-cigarettes is limited. While e-cigarette aerosol may contain fewer toxicants than cigarette smoke, studies evaluating whether e-cigarettes are less harmful than cigarettes are inconclusive. Some evidence suggests that e-cigarette use may facilitate smoking cessation, but definitive data are lacking. No e-cigarette has been approved by FDA as a cessation aid. Environmental concerns and issues regarding non-user exposure exist. The health impact of e-cigarettes, for users and the public, cannot be determined with currently available data.

Biological 2-Input Decoder Circuit in Human Cells

Science.gov (United States)

2015-01-01

Decoders are combinational circuits that convert information from n inputs to a maximum of 2n outputs. This operation is of major importance in computing systems yet it is vastly underexplored in synthetic biology. Here, we present a synthetic gene network architecture that operates as a biological decoder in human cells, converting 2 inputs to 4 outputs. As a proof-of-principle, we use small molecules to emulate the two inputs and fluorescent reporters as the corresponding four outputs. The experiments are performed using transient transfections in human kidney embryonic cells and the characterization by fluorescence microscopy and flow cytometry. We show a clear separation between the ON and OFF mean fluorescent intensity states. Additionally, we adopt the integrated mean fluorescence intensity for the characterization of the circuit and show that this metric is more robust to transfection conditions when compared to the mean fluorescent intensity. To conclude, we present the first implementation of a genetic decoder. This combinational system can be valuable toward engineering higher-order circuits as well as accommodate a multiplexed interface with endogenous cellular functions. PMID:24694115

Biological 2-input decoder circuit in human cells.

Science.gov (United States)

Guinn, Michael; Bleris, Leonidas

2014-08-15

Decoders are combinational circuits that convert information from n inputs to a maximum of 2(n) outputs. This operation is of major importance in computing systems yet it is vastly underexplored in synthetic biology. Here, we present a synthetic gene network architecture that operates as a biological decoder in human cells, converting 2 inputs to 4 outputs. As a proof-of-principle, we use small molecules to emulate the two inputs and fluorescent reporters as the corresponding four outputs. The experiments are performed using transient transfections in human kidney embryonic cells and the characterization by fluorescence microscopy and flow cytometry. We show a clear separation between the ON and OFF mean fluorescent intensity states. Additionally, we adopt the integrated mean fluorescence intensity for the characterization of the circuit and show that this metric is more robust to transfection conditions when compared to the mean fluorescent intensity. To conclude, we present the first implementation of a genetic decoder. This combinational system can be valuable toward engineering higher-order circuits as well as accommodate a multiplexed interface with endogenous cellular functions.

Human mesenchymal stromal cells : biological characterization and clinical application

NARCIS (Netherlands)

Bernardo, Maria Ester

2010-01-01

This thesis focuses on the characterization of the biological and functional properties of human mesenchymal stromal cells (MSCs), isolated from different tissue sources. The differentiation capacity of MSCs from fetal and adult tissues has been tested and compared. Umbilical cord blood (UCB) has

The DNA-damage response in human biology and disease

DEFF Research Database (Denmark)

Jackson, Stephen P; Bartek, Jiri

2009-01-01

, signal its presence and mediate its repair. Such responses, which have an impact on a wide range of cellular events, are biologically significant because they prevent diverse human diseases. Our improving understanding of DNA-damage responses is providing new avenues for disease management....

BIOLOGY OF HUMAN MALARIA PLASMODIA INCLUDING PLASMODIUM KNOWLESI

Directory of Open Access Journals (Sweden)

Spinello Antinori

2012-03-01

Full Text Available Malaria is a vector-borne infection caused by unicellular parasite of the genus Plasmodium. Plasmodia are obligate intracellular parasites that in humans after a clinically silent replication phase in the liver are able to infect and replicate within the erythrocytes. Four species (P.falciparum, P.malariae, P.ovale and P.vivax are traditionally recognized as responsible of natural infection in human beings but the recent upsurge of P.knowlesi malaria in South-East Asia has led clinicians to consider it as the fifth human malaria parasite. Recent studies in wild-living apes in Africa have revealed that P.falciparum, the most deadly form of human malaria, is not only human-host restricted as previously believed and its phylogenetic lineage is much more complex with new species identified in gorilla, bonobo and chimpanzee. Although less impressive, new data on biology of P.malariae, P.ovale and P.vivax are also emerging and will be briefly discussed in this review.

Biologic activities of recombinant human-beta-defensin-4 toward cultured human cancer cells.

Science.gov (United States)

Gerashchenko, O L; Zhuravel, E V; Skachkova, O V; Khranovska, N N; Filonenko, V V; Pogrebnoy, P V; Soldatkina, M A

2013-06-01

The aim of the study was in vitro analysis of biological activity of recombinant human beta-defensin-4 (rec-hBD-4). hBD-4 cDNA was cloned into pGEX-2T vector, and recombinant plasmid was transformed into E. coli BL21(DE3) cells. To purify soluble fusion GST-hBD-4 protein, affinity chromatography was applied. Rec-hBD-4 was cleaved from the fusion protein with thrombin, and purified by reverse phase chromatography on Sep-Pack C18. Effects of rec-hBD-4 on proliferation, viability, cell cycle distribution, substrate-independent growth, and mobility of cultured human cancer cells of A431, A549, and TPC-1 lines were analyzed by direct cell counting technique, MTT assay, flow cytofluorometry, colony forming assay in semi-soft medium, and wound healing assay. Rec-hBD-4 was expressed in bacterial cells as GST-hBD-4 fusion protein, and purified by routine 3-step procedure (affine chromatography on glutathione-agarose, cleavage of fusion protein by thrombin, and reverse phase chromatography). Analysis of in vitro activity of rec-hBD-4 toward three human cancer cell lines has demonstrated that the defensin is capable to affect cell behaviour in concentration-dependent manner. In 1-100 nM concentrations rec-hBD-4 significantly stimulates cancer cell proliferation and viability, and promotes cell cycle progression through G2/M checkpoint, greatly enhances colony-forming activity and mobility of the cells. Treatment of the cells with 500 nM of rec-hBD-4 resulted in opposite effects: significant suppression of cell proliferation and viability, blockage of cell cycle in G1/S checkpoint, significant inhibition of cell migration and colony forming activity. Recombinant human beta-defensin-4 is biologically active peptide capable to cause oppositely directed effects toward biologic features of cancer cells in vitro dependent on its concentration.

Three-Dimensional scanning transmission electron microscopy of biological specimens

KAUST Repository

De Jonge, Niels

2010-01-18

A three-dimensional (3D) reconstruction of the cytoskeleton and a clathrin-coated pit in mammalian cells has been achieved from a focal-series of images recorded in an aberration-corrected scanning transmission electron microscope (STEM). The specimen was a metallic replica of the biological structure comprising Pt nanoparticles 2-3 nm in diameter, with a high stability under electron beam radiation. The 3D dataset was processed by an automated deconvolution procedure. The lateral resolution was 1.1 nm, set by pixel size. Particles differing by only 10 nm in vertical position were identified as separate objects with greater than 20% dip in contrast between them. We refer to this value as the axial resolution of the deconvolution or reconstruction, the ability to recognize two objects, which were unresolved in the original dataset. The resolution of the reconstruction is comparable to that achieved by tilt-series transmission electron microscopy. However, the focal-series method does not require mechanical tilting and is therefore much faster. 3D STEM images were also recorded of the Golgi ribbon in conventional thin sections containing 3T3 cells with a comparable axial resolution in the deconvolved dataset. © 2010 Microscopy Society of America.

Analysis of the three-dimensional delamination behavior of stretchable electronics applications

NARCIS (Netherlands)

Sluis, van der O.; Timmermans, P.H.M.; Zanden, van der E.J.L.; Hoefnagels, J.P.M.; Ernst, L.J.

2009-01-01

Stretchable electronics offer potential application areasin biological implants interacting with human tissue. Furthermore, they facilitate increased design freedom of electronic products. Typical applications can be found in healthcare, wellness and functional clothes. A key requirement on these

Metabolic adaptation of a human pathogen during chronic infections - a systems biology approach

DEFF Research Database (Denmark)

Thøgersen, Juliane Charlotte

modeling to uncover how human pathogens adapt to the human host. Pseudomonas aeruginosa infections in cystic fibrosis patients are used as a model system for under-­‐ standing these adaptation processes. The exploratory systems biology approach facilitates identification of important phenotypes...... by classical molecular biology approaches where genes and reactions typically are investigated in a one to one relationship. This thesis is an example of how mathematical approaches and modeling can facilitate new biologi-­‐ cal understanding and provide new surprising ideas to important biological processes....... and metabolic pathways that are necessary or related to establishment of chronic infections. Archetypal analysis showed to be successful in extracting relevant phenotypes from global gene expression da-­‐ ta. Furthermore, genome-­‐scale metabolic modeling showed to be useful in connecting the genotype...

2. Brazilian Congress on Cell Biology and 7. Brazilian Colloquium on Electron Microscopy - Abstracts

International Nuclear Information System (INIS)

1980-01-01

Immunology, virology, bacteriology, genetics and protozoology are some of the subjects treated in the 2. Brazilian Congress on Cell Biology. Studies using radioisotopic techniques and ultrastructural cytological studies are presented. Use of optical - and electron microscopy in some of these studies is discussed. In the 7. Brazilian Colloquium on Electron Microscopy, the application of this technique to materials science is discussed (failure analysis in metallurgy, energy dispersion X-ray analysis, etc). (I.C.R.) [pt

Electronic cigarettes: human health effects

Science.gov (United States)

Callahan-Lyon, Priscilla

2014-01-01

Objective With the rapid increase in use of electronic nicotine delivery systems (ENDS), such as electronic cigarettes (e-cigarettes), users and non-users are exposed to the aerosol and product constituents. This is a review of published data on the human health effects of exposure to e-cigarettes and their components. Methods Literature searches were conducted through September 2013 using multiple electronic databases. Results Forty-four articles are included in this analysis. E-cigarette aerosols may contain propylene glycol, glycerol, flavourings, other chemicals and, usually, nicotine. Aerosolised propylene glycol and glycerol produce mouth and throat irritation and dry cough. No data on the effects of flavouring inhalation were identified. Data on short-term health effects are limited and there are no adequate data on long-term effects. Aerosol exposure may be associated with respiratory function impairment, and serum cotinine levels are similar to those in traditional cigarette smokers. The high nicotine concentrations of some products increase exposure risks for non-users, particularly children. The dangers of secondhand and thirdhand aerosol exposure have not been thoroughly evaluated. Conclusions Scientific evidence regarding the human health effects of e-cigarettes is limited. While e-cigarette aerosol may contain fewer toxicants than cigarette smoke, studies evaluating whether e-cigarettes are less harmful than cigarettes are inconclusive. Some evidence suggests that e-cigarette use may facilitate smoking cessation, but definitive data are lacking. No e-cigarette has been approved by FDA as a cessation aid. Environmental concerns and issues regarding non-user exposure exist. The health impact of e-cigarettes, for users and the public, cannot be determined with currently available data. PMID:24732161

Prediction of phenotypes of missense mutations in human proteins from biological assemblies.

Science.gov (United States)

Wei, Qiong; Xu, Qifang; Dunbrack, Roland L

2013-02-01

Single nucleotide polymorphisms (SNPs) are the most frequent variation in the human genome. Nonsynonymous SNPs that lead to missense mutations can be neutral or deleterious, and several computational methods have been presented that predict the phenotype of human missense mutations. These methods use sequence-based and structure-based features in various combinations, relying on different statistical distributions of these features for deleterious and neutral mutations. One structure-based feature that has not been studied significantly is the accessible surface area within biologically relevant oligomeric assemblies. These assemblies are different from the crystallographic asymmetric unit for more than half of X-ray crystal structures. We find that mutations in the core of proteins or in the interfaces in biological assemblies are significantly more likely to be disease-associated than those on the surface of the biological assemblies. For structures with more than one protein in the biological assembly (whether the same sequence or different), we find the accessible surface area from biological assemblies provides a statistically significant improvement in prediction over the accessible surface area of monomers from protein crystal structures (P = 6e-5). When adding this information to sequence-based features such as the difference between wildtype and mutant position-specific profile scores, the improvement from biological assemblies is statistically significant but much smaller (P = 0.018). Combining this information with sequence-based features in a support vector machine leads to 82% accuracy on a balanced dataset of 50% disease-associated mutations from SwissVar and 50% neutral mutations from human/primate sequence differences in orthologous proteins. Copyright © 2012 Wiley Periodicals, Inc.

Social justice and research using human biological material: A ...

African Journals Online (AJOL)

Social justice and research using human biological material: A response to Mahomed, Nöthling-Slabbert and Pepper. ... South African Medical Journal ... In a recent article, Mahomed, Nöthling-Slabbert and Pepper proposed that research participants should be entitled to share in the profits emanating from such research ...

Quantification of Wine Mixtures with an Electronic Nose and a Human Panel

Science.gov (United States)

Aleixandre, Manuel; Cabellos, Juan M.; Arroyo, Teresa; Horrillo, M. C.

2018-01-01

In this work, an electronic nose and a human panel were used for the quantification of wines formed by binary mixtures of four white grape varieties and two varieties of red wines at different percentages (from 0 to 100% in 10% steps for the electronic nose and from 0 to 100% in 25% steps for the human panel). The wines were prepared using the traditional method with commercial yeasts. Both techniques were able to quantify the mixtures tested, but it is important to note that the technology of the electronic nose is faster, simpler, and more objective than the human panel. In addition, better results of quantification were also obtained using the electronic nose. PMID:29484296

Treatment of textiles industrial wastewater by electron beam and biological treatment (sbr)

International Nuclear Information System (INIS)

Khomsaton Abu Bakar; Khairul Zaman Mohd Dahlan; Zulkafli Ghazali; Ting Teo Ming

2008-08-01

Study of treating textiles industrial wastewater with combined of electron beam and Tower Style Biological Treatment (TSB) was investigated in Korea. In this project, textiles wastewater was also treated with electron beam, but hybrid with Sequencing Batch Reactor (SBR). The purpose of this research is to develop combined electron beam treatment with existing biological treatment facility (SBR), of textile industries in Malaysia. The objectives of this project are to determine the effective irradiation parameter for treatment and to identify effective total retention time in SBR system. To achieve the objective, samples fill in polypropyle tray were irradiated at 1 MeV, 20 mA and 1 MeV ,5 mA at doses 11, 20, 30, 40 and 50 kGy respectively. Raw effluent and two series of irradiated effluent at 1 MeV 20 mA (11, 20, 30, 40 and 50 kGy) and 1 MeV 5 mA (11, 20, 30, 40 and 50 kGy) were then treated in SBR system. Samples were analysed at 6, 14 and 20 hrs after aeration in the SBR. The results show that, average reduction in BOD was about 2-11% after irradiated at 5 mA, and the percentage increased to 21-73% after treatment in SBR system. At 20 mA, BOD reduced to 7-29% during irradiation and the value increased to 57-87% after treatment in SBR system. (Author)

AFM Nanotools for Surgery of Biological Cells

Energy Technology Data Exchange (ETDEWEB)

Beard, J D; Gordeev, S N [Department of Physics, Claverton Down, University of Bath, Bath, BA2 7AY (United Kingdom); Guy, R H, E-mail: jdb28@bath.ac.uk [Department of Pharmacy and Pharmacology, Claverton Down, University of Bath, Bath, BA2 7AY (United Kingdom)

2011-03-01

Using a method of electron-beam induced deposition, we have been able to fabricate specialized AFM probes with application as 'nanotools' for the manipulation of biological structures ('nanosurgery'). We describe several such tools, including a 'nanoscalpel', 'nanoneedles' for probing intracellular structures, and a 'nanotome' which can separate surface layers from a biological structure. These applications are demonstrated by performing nanomanipulation on corneocyte cells from the outer layer of human skin.

The SCID-hu mouse and its application to human radiation biology

International Nuclear Information System (INIS)

Kyoizumi, Seishi; Akiyama, Mitoshi; McCune, J.M.; Namikawa, Reiko.

1993-01-01

The radiobiological study of humans has been hampered by a lack of suitable in vivo experimental models. Of course, acute and chronic radiation effects in humans have been documented in the studies of atomic bomb (A-bomb) survivors and patients irradiated either by therapeutic intent or by accident. However, the information gained from these studies has been limited by the difficulties in estimating precise radiation doses and in obtaining biological samples for directly analyzing the processes of radiation-induced pathogenesis. With these issues in mind, we propose that the severe combined immunodeficient mouse-human chimera can be used as an in vivo experimental model for human radiation biology. We have developed techniques by which normal human bone marrow can be implanted into immunodeficient C.B-17 scid/scid (SCID) mice (S. Kyoizumi et al, Blood 79, 1704, 1992). We have report that this in vivo model can be used for the analysis of radiation damage to human bone marrow. After whole-body irradiation of the engrafted animals, human progenitor cells within the human marrow were destroyed in a dose-dependent manner (D 0 = 0.7-1.0Gy, n = 1.0). Acute hematotoxicity was reduced when the radioprotective agent (WR-2721) was administered prior to irradiation. After low dose irradiation, the recovery of human progenitor activity was accelerated by treatment with human granulocyte-colony stimulating factor (G-CSF). This small animal model may prove amenable for the risk analysis of human radiation exposure as well as for the development of new modalities for the prevention and treatment of radiotoxic damage to the human hematopoietic system. (author)

Approaching an experimental electron density model of the biologically active trans -epoxysuccinyl amide group-Substituent effects vs. crystal packing

Energy Technology Data Exchange (ETDEWEB)

Shi, Ming W.; Stewart, Scott G.; Sobolev, Alexandre N.; Dittrich, Birger; Schirmeister, Tanja; Luger, Peter; Hesse, Malte; Chen, Yu-Sheng; Spackman, Peter R.; Spackman, Mark A.; Grabowsky, Simon (Heinrich-Heine); (Freie); (UC); (Bremen); (JG-UM); (UWA)

2017-01-24

The trans-epoxysuccinyl amide group as a biologically active moiety in cysteine protease inhibitors such as loxistatin acid E64c has been used as a benchmark system for theoretical studies of environmental effects on the electron density of small active ingredients in relation to their biological activity. Here, the synthesis and the electronic properties of the smallest possible active site model compound are reported to close the gap between the unknown experimental electron density of trans-epoxysuccinyl amides and the well-known function of related drugs. Intramolecular substituent effects are separated from intermolecular crystal packing effects on the electron density, which allows us to predict the conditions under which an experimental electron density investigation on trans-epoxysuccinyl amides will be possible. In this context, the special importance of the carboxylic acid function in the model compound for both crystal packing and biological activity is revealed through the novel tool of model energy analysis.

The Human Genome Project: big science transforms biology and medicine

OpenAIRE

Hood, Leroy; Rowen, Lee

2013-01-01

The Human Genome Project has transformed biology through its integrated big science approach to deciphering a reference human genome sequence along with the complete sequences of key model organisms. The project exemplifies the power, necessity and success of large, integrated, cross-disciplinary efforts - so-called ‘big science’ - directed towards complex major objectives. In this article, we discuss the ways in which this ambitious endeavor led to the development of novel technologies and a...

Biological Applications and Transmission Electron Microscopy Investigations of Mesoporous Silica Nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Trewyn, Brian G. [Iowa State Univ., Ames, IA (United States)

2006-01-01

The research presented and discussed within involves the development of novel biological applications of mesoporous silica nanoparticles (MSN) and an investigation of mesoporous material by transmission electron microscopy (TEM). Mesoporous silica nanoparticles organically functionalized shown to undergo endocytosis in cancer cells and drug release from the pores was controlled intracellularly and intercellularly. Transmission electron microscopy investigations demonstrated the variety of morphologies produced in this field of mesoporous silica nanomaterial synthesis. A series of room-temperature ionic liquid (RTIL) containing mesoporous silica nanoparticle (MSN) materials with various particle morphologies, including spheres, ellipsoids, rods, and tubes, were synthesized. By changing the RTIL template, the pore morphology was tuned from the MCM-41 type of hexagonal mesopores to rotational moire type of helical channels, and to wormhole-like porous structures. These materials were used as controlled release delivery nanodevices to deliver antibacterial ionic liquids against Escherichia coli K12. The involvement of a specific organosiloxane function group, covalently attached to the exterior of fluorescein doped mesoporous silica nanoparticles (FITC-MSN), on the degree and kinetics of endocytosis in cancer and plant cells was investigated. The kinetics of endocystosis of TEG coated FITC-MSN is significantly quicker than FITC-MSN as determined by flow cytometry experiments. The fluorescence confocal microscopy investigation showed the endocytosis of TEG coated-FITC MSN triethylene glycol grafted fluorescein doped MSN (TEG coated-FITC MSN) into both KeLa cells and Tobacco root protoplasts. Once the synthesis of a controlled-release delivery system based on MCM-41-type mesoporous silica nanorods capped by disulfide bonds with superparamagnetic iron oxide nanoparticles was completed. The material was characterized by general methods and the dosage and kinetics of the

Semiconductor Devices Inspired By and Integrated With Biology

Energy Technology Data Exchange (ETDEWEB)

Rogers, John [University of Illinois

2012-04-25

Biology is curved, soft and elastic; silicon wafers are not. Semiconductor technologies that can bridge this gap in form and mechanics will create new opportunities in devices that adopt biologically inspired designs or require intimate integration with the human body. This talk describes the development of ideas for electronics that offer the performance of state-of-the-art, wafer- based systems but with the mechanical properties of a rubber band. We explain the underlying materials science and mechanics of these approaches, and illustrate their use in (1) bio- integrated, ‘tissue-like’ electronics with unique capabilities for mapping cardiac and neural electrophysiology, and (2) bio-inspired, ‘eyeball’ cameras with exceptional imaging properties enabled by curvilinear, Petzval designs.

Medical and biological progress and the European Convention on Human Rights.

Science.gov (United States)

Byk, C

1992-01-01

The advances made in life sciences are one of the most significant features of the 20th century scientific revolution and human rights obviously enjoy prominence among the legal issues affected by the development of medicine. The case law of the organs of the European Convention on Human Rights arising from developments in the biomedical sciences is reviewed. The approach of especially the European Commission on Human Rights to the consequences of advances in the life sciences on the protection of the individual's physical integrity and the protection of freedom of thought and private and family life is analysed. 'Contrary to what we are led to believe, it is not from the starting-point of biology that a particular idea of man can be formed; on the contrary, it is from the starting-point of a particular idea of man that biology can be used to serve him': F Gros, F Jacob & P Royer Life Sciences and Society (1979) 288.

HExpoChem: a systems biology resource to explore human exposure to chemicals

DEFF Research Database (Denmark)

Taboureau, Olivier; Jacobsen, Ulrik Plesner; Kalhauge, Christian Gram

2013-01-01

of computational biology approaches are needed to assess the health risks of chemical exposure. Here we present HExpoChem, a tool based on environmental chemicals and their bioactivities on human proteins with the objective of aiding the qualitative exploration of human exposure to chemicals. The chemical...

Biologic Rhythms Derived from Siberian Mammoths Hairs

Energy Technology Data Exchange (ETDEWEB)

M Spilde; A Lanzirotti; C Qualls; G Phillips; A Ali; L Agenbroad; O Appenzeller

2011-12-31

Hair is preserved for millennia in permafrost; it enshrines a record of biologic rhythms and offers a glimpse at chronobiology as it was in extinct animals. Here we compare biologic rhythms gleaned from mammoth's hairs with those of modern human hair. Four mammoths' hairs came from varying locations in Siberia 4600 km, four time zones, apart ranging in age between 18,000 and 20,000 years before present. We used two contemporaneous human hairs for comparison. Power spectra derived from hydrogen isotope ratios along the length of the hairs gave insight into biologic rhythms, which were different in the mammoths depending on location and differed from humans. Hair growth for mammoths was {approx}31 cms/year and {approx}16 cms/year for humans. Recurrent annual rhythms of slow and fast growth varying from 3.4 weeks/cycles to 8.7 weeks/cycles for slow periods and 1.2 weeks/cycles to 2.2 weeks/cycles for fast periods were identified in mammoth's hairs. The mineral content of mammoth's hairs was measured by electron microprobe analysis (k-ratios), which showed no differences in sulfur amongst the mammoth hairs but significantly more iron then in human hair. The fractal nature of the data derived from the hairs became evident in Mandelbrot sets derived from hydrogen isotope ratios, mineral content and geographic location. Confocal microscopy and scanning electron microscopy showed varied degrees of preservation of the cuticle largely independent of age but not location of the specimens. X-ray fluorescence microprobe and fluorescence computed micro-tomography analyses allowed evaluation of metal distribution and visualization of hollow tubes in the mammoth's hairs. Seasonal variations in iron and copper content combined with spectral analyses gave insights into variation in food intake of the animals. Biologic rhythms gleaned from power spectral plots obtained by modern methods revealed life style and behavior of extinct mega-fauna.

Biologic rhythms derived from Siberian mammoths' hairs.

Directory of Open Access Journals (Sweden)

Mike Spilde

Full Text Available Hair is preserved for millennia in permafrost; it enshrines a record of biologic rhythms and offers a glimpse at chronobiology as it was in extinct animals. Here we compare biologic rhythms gleaned from mammoth's hairs with those of modern human hair. Four mammoths' hairs came from varying locations in Siberia 4600 km, four time zones, apart ranging in age between 18,000 and 20,000 years before present. We used two contemporaneous human hairs for comparison. Power spectra derived from hydrogen isotope ratios along the length of the hairs gave insight into biologic rhythms, which were different in the mammoths depending on location and differed from humans. Hair growth for mammoths was ∼31 cms/year and ∼16 cms/year for humans. Recurrent annual rhythms of slow and fast growth varying from 3.4 weeks/cycles to 8.7 weeks/cycles for slow periods and 1.2 weeks/cycles to 2.2 weeks/cycles for fast periods were identified in mammoth's hairs. The mineral content of mammoth's hairs was measured by electron microprobe analysis (k-ratios, which showed no differences in sulfur amongst the mammoth hairs but significantly more iron then in human hair. The fractal nature of the data derived from the hairs became evident in Mandelbrot sets derived from hydrogen isotope ratios, mineral content and geographic location. Confocal microscopy and scanning electron microscopy showed varied degrees of preservation of the cuticle largely independent of age but not location of the specimens. X-ray fluorescence microprobe and fluorescence computed micro-tomography analyses allowed evaluation of metal distribution and visualization of hollow tubes in the mammoth's hairs. Seasonal variations in iron and copper content combined with spectral analyses gave insights into variation in food intake of the animals. Biologic rhythms gleaned from power spectral plots obtained by modern methods revealed life style and behavior of extinct mega-fauna.

From bricolage to BioBricks™: Synthetic biology and rational design.

Science.gov (United States)

Lewens, Tim

2013-12-01

Synthetic biology is often described as a project that applies rational design methods to the organic world. Although humans have influenced organic lineages in many ways, it is nonetheless reasonable to place synthetic biology towards one end of a continuum between purely 'blind' processes of organic modification at one extreme, and wholly rational, design-led processes at the other. An example from evolutionary electronics illustrates some of the constraints imposed by the rational design methodology itself. These constraints reinforce the limitations of the synthetic biology ideal, limitations that are often freely acknowledged by synthetic biology's own practitioners. The synthetic biology methodology reflects a series of constraints imposed on finite human designers who wish, as far as is practicable, to communicate with each other and to intervene in nature in reasonably targeted and well-understood ways. This is better understood as indicative of an underlying awareness of human limitations, rather than as expressive of an objectionable impulse to mastery over nature. Copyright © 2013 Elsevier Ltd. All rights reserved.

Casual Games and Casual Learning About Human Biological Systems

Science.gov (United States)

Price, C. Aaron; Gean, Katherine; Christensen, Claire G.; Beheshti, Elham; Pernot, Bryn; Segovia, Gloria; Person, Halcyon; Beasley, Steven; Ward, Patricia

2016-02-01

Casual games are everywhere. People play them throughout life to pass the time, to engage in social interactions, and to learn. However, their simplicity and use in distraction-heavy environments can attenuate their potential for learning. This experimental study explored the effects playing an online, casual game has on awareness of human biological systems. Two hundred and forty-two children were given pretests at a Museum and posttests at home after playing either a treatment or control game. Also, 41 children were interviewed to explore deeper meanings behind the test results. Results show modest improvement in scientific attitudes, ability to identify human biological systems and in the children's ability to describe how those systems work together in real-world scenarios. Interviews reveal that children drew upon their prior school learning as they played the game. Also, on the surface they perceived the game as mainly entertainment but were easily able to discern learning outcomes when prompted. Implications for the design of casual games and how they can be used to enhance transfer of knowledge from the classroom to everyday life are discussed.

Human pluripotent stem cells: an emerging model in developmental biology.

Science.gov (United States)

Zhu, Zengrong; Huangfu, Danwei

2013-02-01

Developmental biology has long benefited from studies of classic model organisms. Recently, human pluripotent stem cells (hPSCs), including human embryonic stem cells and human induced pluripotent stem cells, have emerged as a new model system that offers unique advantages for developmental studies. Here, we discuss how studies of hPSCs can complement classic approaches using model organisms, and how hPSCs can be used to recapitulate aspects of human embryonic development 'in a dish'. We also summarize some of the recently developed genetic tools that greatly facilitate the interrogation of gene function during hPSC differentiation. With the development of high-throughput screening technologies, hPSCs have the potential to revolutionize gene discovery in mammalian development.

A geometric initial guess for localized electronic orbitals in modular biological systems

Energy Technology Data Exchange (ETDEWEB)

Beckman, P. G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Univ. of Chicago, IL (United States); Fattebert, J. L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lau, E. Y. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Osei-Kuffuor, D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2017-09-11

Recent first-principles molecular dynamics algorithms using localized electronic orbitals have achieved O(N) complexity and controlled accuracy in simulating systems with finite band gaps. However, accurately deter- mining the centers of these localized orbitals during simulation setup may require O(N³) operations, which is computationally infeasible for many biological systems. We present an O(N) approach for approximating orbital centers in proteins, DNA, and RNA which uses non-localized solutions for a set of fixed-size subproblems to create a set of geometric maps applicable to larger systems. This scalable approach, used as an initial guess in the O(N) first-principles molecular dynamics code MGmol, facilitates first-principles simulations in biological systems of sizes which were previously impossible.

Quantitative mass spectrometry of unconventional human biological matrices

Science.gov (United States)

Dutkiewicz, Ewelina P.; Urban, Pawel L.

2016-10-01

The development of sensitive and versatile mass spectrometric methodology has fuelled interest in the analysis of metabolites and drugs in unconventional biological specimens. Here, we discuss the analysis of eight human matrices-hair, nail, breath, saliva, tears, meibum, nasal mucus and skin excretions (including sweat)-by mass spectrometry (MS). The use of such specimens brings a number of advantages, the most important being non-invasive sampling, the limited risk of adulteration and the ability to obtain information that complements blood and urine tests. The most often studied matrices are hair, breath and saliva. This review primarily focuses on endogenous (e.g. potential biomarkers, hormones) and exogenous (e.g. drugs, environmental contaminants) small molecules. The majority of analytical methods used chromatographic separation prior to MS; however, such a hyphenated methodology greatly limits analytical throughput. On the other hand, the mass spectrometric methods that exclude chromatographic separation are fast but suffer from matrix interferences. To enable development of quantitative assays for unconventional matrices, it is desirable to standardize the protocols for the analysis of each specimen and create appropriate certified reference materials. Overcoming these challenges will make analysis of unconventional human biological matrices more common in a clinical setting. This article is part of the themed issue 'Quantitative mass spectrometry'.

Examination of Signatures of Recent Positive Selection on Genes Involved in Human Sialic Acid Biology.

Science.gov (United States)

Moon, Jiyun M; Aronoff, David M; Capra, John A; Abbot, Patrick; Rokas, Antonis

2018-03-28

Sialic acids are nine carbon sugars ubiquitously found on the surfaces of vertebrate cells and are involved in various immune response-related processes. In humans, at least 58 genes spanning diverse functions, from biosynthesis and activation to recycling and degradation, are involved in sialic acid biology. Because of their role in immunity, sialic acid biology genes have been hypothesized to exhibit elevated rates of evolutionary change. Consistent with this hypothesis, several genes involved in sialic acid biology have experienced higher rates of non-synonymous substitutions in the human lineage than their counterparts in other great apes, perhaps in response to ancient pathogens that infected hominins millions of years ago (paleopathogens). To test whether sialic acid biology genes have also experienced more recent positive selection during the evolution of the modern human lineage, reflecting adaptation to contemporary cosmopolitan or geographically-restricted pathogens, we examined whether their protein-coding regions showed evidence of recent hard and soft selective sweeps. This examination involved the calculation of four measures that quantify changes in allele frequency spectra, extent of population differentiation, and haplotype homozygosity caused by recent hard and soft selective sweeps for 55 sialic acid biology genes using publicly available whole genome sequencing data from 1,668 humans from three ethnic groups. To disentangle evidence for selection from confounding demographic effects, we compared the observed patterns in sialic acid biology genes to simulated sequences of the same length under a model of neutral evolution that takes into account human demographic history. We found that the patterns of genetic variation of most sialic acid biology genes did not significantly deviate from neutral expectations and were not significantly different among genes belonging to different functional categories. Those few sialic acid biology genes that

T3 Regulates a Human Macrophage-Derived TSH-β Splice Variant: Implications for Human Bone Biology.

Science.gov (United States)

Baliram, R; Latif, R; Morshed, S A; Zaidi, M; Davies, T F

2016-09-01

TSH and thyroid hormones (T3 and T4) are intimately involved in bone biology. We have previously reported the presence of a murine TSH-β splice variant (TSH-βv) expressed specifically in bone marrow-derived macrophages and that exerted an osteoprotective effect by inducing osteoblastogenesis. To extend this observation and its relevance to human bone biology, we set out to identify and characterize a TSH-β variant in human macrophages. Real-time PCR analyses using human TSH-β-specific primers identified a 364-bp product in macrophages, bone marrow, and peripheral blood mononuclear cells that was sequence verified and was homologous to a human TSH-βv previously reported. We then examined TSH-βv regulation using the THP-1 human monocyte cell line matured into macrophages. After 4 days, 46.1% of the THP-1 cells expressed the macrophage markers CD-14 and macrophage colony-stimulating factor and exhibited typical morphological characteristics of macrophages. Real-time PCR analyses of these cells treated in a dose-dependent manner with T3 showed a 14-fold induction of human TSH-βv mRNA and variant protein. Furthermore, these human TSH-βv-positive cells, induced by T3 exposure, had categorized into both M1 and M2 macrophage phenotypes as evidenced by the expression of macrophage colony-stimulating factor for M1 and CCL-22 for M2. These data indicate that in hyperthyroidism, bone marrow resident macrophages have the potential to exert enhanced osteoprotective effects by oversecreting human TSH-βv, which may exert its local osteoprotective role via osteoblast and osteoclast TSH receptors.

Monitoring of biological odour filtration in closed environments with olfactometry and an electronic nose

NARCIS (Netherlands)

Willers, H.C.; Gijsel, de P.; Ogink, N.W.M.; Amico, D' A.; Martinelli, E.; Natale, Di C.; Ras, van N.; Waarde, van der J.

2004-01-01

Air treatment with a compact biological membrane filter, and air quality monitoring with an electronic nose were tested in the laboratory on air from a cage containing six mice. Additional analyses of air to and from the filter were performed using olfactometry and ammonia and hydrogen sulphide gas

DNA markers for forensic identification of non-human biological traces

NARCIS (Netherlands)

Wesselink, M.

2018-01-01

In this thesis, DNA markers are described that enable forensically relevant classification of three groups of non-human biological traces: fungi (Chapter 1), domestic cats (Chapters 2, 3 an d 4) and birch trees (Chapters 5 and 6). Because the forensic questions associated with these traces require

Thermal analysis of epidermal electronic devices integrated with human skin considering the effects of interfacial thermal resistance

Science.gov (United States)

Li, Yuhang; Zhang, Jianpeng; Xing, Yufeng; Song, Jizhou

2018-05-01

Epidermal electronic devices (EEDs) have similar mechanical properties as those of human skin such that they can be integrated with human skin for potential applications in monitoring of human vital signs for diagnostic, therapeutic or surgical functions. Thermal management is critical for EEDs in these applications since excessive heating may cause discomfort. Comprehensive analytical studies, finite element analysis and experiments are carried out to study the effects of interfacial thermal resistance between EEDs and human skin on thermal properties of the EED/skin system in this paper. The coupling between the Fourier heat transfer in EEDs and the bio-heat transfer in human skin is accounted in the analytical model based on the transfer matrix method to give accurate predictions on temperatures, which agree well with finite element analysis and experimental measurements. It is shown that the maximum temperature increase of the EED for the case of imperfect bonding between EED and skin is much higher than that of perfect bonding. These results may help the design of EEDs in bi-integrated applications and suggest a valuable route to evaluate the bonding condition between EEDs and biological tissues.

Dose rate effect on micronuclei induction in human blood lymphocytes exposed to single pulse and multiple pulses of electrons.

Science.gov (United States)

Acharya, Santhosh; Bhat, N N; Joseph, Praveen; Sanjeev, Ganesh; Sreedevi, B; Narayana, Y

2011-05-01

The effects of single pulses and multiple pulses of 7 MV electrons on micronuclei (MN) induction in cytokinesis-blocked human peripheral blood lymphocytes (PBLs) were investigated over a wide range of dose rates per pulse (instantaneous dose rate). PBLs were exposed to graded doses of 2, 3, 4, 6, and 8 Gy of single electron pulses of varying pulse widths at different dose rates per pulse, ranging from 1 × 10(6) Gy s(-1) to 3.2 × 10(8) Gy s(-1). Different dose rates per pulse were achieved by changing the dose per electron pulse by adjusting the beam current and pulse width. MN yields per unit absorbed dose after irradiation with single electron pulses were compared with those of multiple pulses of electrons. A significant decrease in the MN yield with increasing dose rates per pulse was observed, when dose was delivered by a single electron pulse. However, no reduction in the MN yield was observed when dose was delivered by multiple pulses of electrons. The decrease in the yield at high dose rates per pulse suggests possible radical recombination, which leads to decreased biological damage. Cellular response to the presence of very large numbers of chromosomal breaks may also alter the damage.

Biological psychological and social determinants of old age: Bio-psycho-social aspects of human aging

Directory of Open Access Journals (Sweden)

Małgorzata Dziechciaż

2014-11-01

Full Text Available Biological psychological and social determinants of old age: Bio-psycho-social aspects of human aging. The aging of humans is a physiological and dynamic process ongoing with time. In accordance with most gerontologists’ assertions it starts in the fourth decade of life and leads to death. The process of human aging is complex and individualized, occurs in the biological, psychological and social sphere. Biological aging is characterized by progressive age-changes in metabolism and physicochemical properties of cells, leading to impaired self-regulation, regeneration, and to structural changes and functional tissues and organs. It is a natural and irreversible process which can run as successful aging, typical or pathological. Biological changes that occur with age in the human body affect mood, attitude to the environment, physical condition and social activity, and designate the place of seniors in the family and society. Psychical ageing refers to human awareness and his adaptability to the ageing process. Among adaptation attitudes we can differentiate: constructive, dependence, hostile towards others and towards self attitudes. With progressed age, difficulties with adjustment to the new situation are increasing, adverse changes in the cognitive and intellectual sphere take place, perception process involutes, perceived sensations and information received is lowered, and thinking processes change. Social ageing is limited to the role of an old person is culturally conditioned and may change as customs change. Social ageing refers to how a human being perceives the ageing process and how society sees it.

Effects of electronic cigarette smoking on human health.

Science.gov (United States)

Meo, S A; Al Asiri, S A

2014-01-01

Electronic cigarette smoking is gaining dramatic popularity and is steadily spreading among the adolescents, high income, urban population around the world. The aim of this study is to highlight the hazards of e-cigarette smoking on human health. In this study, we identified 38 published studies through a systematic database searches including ISI-web of science and pub-med. We searched the related literature by using the key words including Electronic cigarette, E-cigarette, E-vapers, incidence, hazards. Studies in which electronic cigarette smoking hazards was investigated were included in the study. No limitations on publication status, study design of publication were implemented. Finally we included 28 publications and remaining 10 were excluded. E-smoking can cause, nausea, vomiting, headache, dizziness, choking, burn injuries, upper respiratory tract irritation, dry cough, dryness of the eyes and mucous membrane, release of cytokines and pro-inflammatory mediators, allergic airway inflammation, decreased exhaled nitric oxide (FeNO) synthesis in the lungs, change in bronchial gene expression and risk of lung cancer. Electronic cigarettes are swiftly promoted as an alternative to conventional cigarette smoking, although its use is highly controversial. Electronic cigarettes are not a smoking cessation product. Non-scientific claims about e-cigarettes are creating confusion in public perception about e-cigarette and people believe that e-cigarettes are safe and less addictive, but its use is unsafe and hazardous to human health. E-cigarette smoking should be regulated in the same way as traditional cigarettes and must be prohibited to children and adolescents.

Classification of human pathogen bacteria for early screening using electronic nose

Science.gov (United States)

Zulkifli, Syahida Amani; Mohamad, Che Wan Syarifah Robiah; Abdullah, Abu Hassan

2017-10-01

This paper present human pathogen bacteria for early screening using electronic nose. Electronic nose (E-nose) known as gas sensor array is a device that analyze the odor measurement give the fast response and less time consuming for clinical diagnosis. Many bacterial pathogens could lead to life threatening infections. Accurate and rapid diagnosis is crucial for the successful management of these infections disease. The conventional method need more time to detect the growth of bacterial. Alternatively, the bacteria are Pseudomonas aeruginosa and Shigella cultured on different media agar can be detected and classifies according to the volatile compound in shorter time using electronic nose (E-nose). Then, the data from electronic nose (E-nose) is processed using statistical method which is principal component analysis (PCA). The study shows the capability of electronic nose (E-nose) for early screening for bacterial infection in human stomach.

Knowledge Gaps in Rodent Pancreas Biology: Taking Human Pluripotent Stem Cell-Derived Pancreatic Beta Cells into Our Own Hands.

Science.gov (United States)

Santosa, Munirah Mohamad; Low, Blaise Su Jun; Pek, Nicole Min Qian; Teo, Adrian Kee Keong

2015-01-01

In the field of stem cell biology and diabetes, we and others seek to derive mature and functional human pancreatic β cells for disease modeling and cell replacement therapy. Traditionally, knowledge gathered from rodents is extended to human pancreas developmental biology research involving human pluripotent stem cells (hPSCs). While much has been learnt from rodent pancreas biology in the early steps toward Pdx1(+) pancreatic progenitors, much less is known about the transition toward Ngn3(+) pancreatic endocrine progenitors. Essentially, the later steps of pancreatic β cell development and maturation remain elusive to date. As a result, the most recent advances in the stem cell and diabetes field have relied upon combinatorial testing of numerous growth factors and chemical compounds in an arbitrary trial-and-error fashion to derive mature and functional human pancreatic β cells from hPSCs. Although this hit-or-miss approach appears to have made some headway in maturing human pancreatic β cells in vitro, its underlying biology is vaguely understood. Therefore, in this mini-review, we discuss some of these late-stage signaling pathways that are involved in human pancreatic β cell differentiation and highlight our current understanding of their relevance in rodent pancreas biology. Our efforts here unravel several novel signaling pathways that can be further studied to shed light on unexplored aspects of rodent pancreas biology. New investigations into these signaling pathways are expected to advance our knowledge in human pancreas developmental biology and to aid in the translation of stem cell biology in the context of diabetes treatments.

Where Synthetic Biology Meets ET

Science.gov (United States)

Rothschild, Lynn J.

2016-01-01

Synthetic biology - the design and construction of new biological parts and systems and the redesign of existing ones for useful purposes - has the potential to transform fields from pharmaceuticals to fuels. Our lab has focused on the potential of synthetic biology to revolutionize all three major parts of astrobiology: Where do we come from? Where are we going? and Are we alone? For the first and third, synthetic biology is allowing us to answer whether the evolutionary narrative that has played out on planet earth is likely to have been unique or universal. For example, in our lab we are re-evolving the biosynthetic pathways of amino acids in order to understand potential capabilities of an early organism with a limited repertoire of amino acids and developing techniques for the recovery of metals from spent electronics on other planetary bodies. And what about the limits for life? Can we create organisms that expand the envelope for life? In the future synthetic biology will play an increasing role in human activities both on earth, in fields as diverse as human health and the industrial production of novel bio-composites. Beyond earth, we will rely increasingly on biologically-provided life support, as we have throughout our evolutionary history. In order to do this, the field will build on two of the great contributions of astrobiology: studies of the origin of life and life in extreme environments.

Distorted wave calculations for electron loss process induced by bare ion impact on biological targets

International Nuclear Information System (INIS)

Monti, J.M.; Tachino, C.A.; Hanssen, J.; Fojón, O.A.; Galassi, M.E.; Champion, C.; Rivarola, R.D.

2014-01-01

Distorted wave models are employed to investigate the electron loss process induced by bare ions on biological targets. The two main reactions which contribute to this process, namely, the single electron ionization as well as the single electron capture are here studied. In order to further assess the validity of the theoretical descriptions used, the influence of particular mechanisms are studied, like dynamic screening for the case of electron ionization and energy deposition on the target by the impacting projectile for the electron capture one. Results are compared with existing experimental data. - Highlights: ► Distorted wave models are used to investigate ion-molecule collisions. ► Differential and total cross-sections for capture and ionization are evaluated. ► The influence of dynamic screening is determined. ► Capture reaction dominates the mean energy deposited by the projectile on the target

Microbial Degradation of Forensic Samples of Biological Origin: Potential Threat to Human DNA Typing.

Science.gov (United States)

Dash, Hirak Ranjan; Das, Surajit

2018-02-01

Forensic biology is a sub-discipline of biological science with an amalgam of other branches of science used in the criminal justice system. Any nucleated cell/tissue harbouring DNA, either live or dead, can be used as forensic exhibits, a source of investigation through DNA typing. These biological materials of human origin are rich source of proteins, carbohydrates, lipids, trace elements as well as water and, thus, provide a virtuous milieu for the growth of microbes. The obstinate microbial growth augments the degradation process and is amplified with the passage of time and improper storage of the biological materials. Degradation of these biological materials carriages a huge challenge in the downstream processes of forensic DNA typing technique, such as short tandem repeats (STR) DNA typing. Microbial degradation yields improper or no PCR amplification, heterozygous peak imbalance, DNA contamination from non-human sources, degradation of DNA by microbial by-products, etc. Consequently, the most precise STR DNA typing technique is nullified and definite opinion can be hardly given with degraded forensic exhibits. Thus, suitable precautionary measures should be taken for proper storage and processing of the biological exhibits to minimize their decaying process by micro-organisms.

Direct Electron Transfer of Enzymes in a Biologically Assembled Conductive Nanomesh Enzyme Platform.

Science.gov (United States)

Lee, Seung-Woo; Lee, Ki-Young; Song, Yong-Won; Choi, Won Kook; Chang, Joonyeon; Yi, Hyunjung

2016-02-24

Nondestructive assembly of a nanostructured enzyme platform is developed in combination of the specific biomolecular attraction and electrostatic coupling for highly efficient direct electron transfer (DET) of enzymes with unprecedented applicability and versatility. The biologically assembled conductive nanomesh enzyme platform enables DET-based flexible integrated biosensors and DET of eight different enzyme with various catalytic activities. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Human Induced Pluripotent Stem Cell-Derived Macrophages for Unraveling Human Macrophage Biology.

Science.gov (United States)

Zhang, Hanrui; Reilly, Muredach P

2017-11-01

Despite a substantial appreciation for the critical role of macrophages in cardiometabolic diseases, understanding of human macrophage biology has been hampered by the lack of reliable and scalable models for cellular and genetic studies. Human induced pluripotent stem cell (iPSC)-derived macrophages (IPSDM), as an unlimited source of subject genotype-specific cells, will undoubtedly play an important role in advancing our understanding of the role of macrophages in human diseases. In this review, we summarize current literature in the differentiation and characterization of IPSDM at phenotypic, functional, and transcriptomic levels. We emphasize the progress in differentiating iPSC to tissue resident macrophages, and in understanding the ontogeny of in vitro differentiated IPSDM that resembles primitive hematopoiesis, rather than adult definitive hematopoiesis. We review the application of IPSDM in modeling both Mendelian genetic disorders and host-pathogen interactions. Finally, we highlighted the potential areas of research using IPSDM in functional validation of coronary artery disease loci in genome-wide association studies, functional genomic analyses, drug testing, and cell therapeutics in cardiovascular diseases. © 2017 American Heart Association, Inc.

The species translation challenge-a systems biology perspective on human and rat bronchial epithelial cells.

Science.gov (United States)

Poussin, Carine; Mathis, Carole; Alexopoulos, Leonidas G; Messinis, Dimitris E; Dulize, Rémi H J; Belcastro, Vincenzo; Melas, Ioannis N; Sakellaropoulos, Theodore; Rhrissorrakrai, Kahn; Bilal, Erhan; Meyer, Pablo; Talikka, Marja; Boué, Stéphanie; Norel, Raquel; Rice, John J; Stolovitzky, Gustavo; Ivanov, Nikolai V; Peitsch, Manuel C; Hoeng, Julia

2014-01-01

The biological responses to external cues such as drugs, chemicals, viruses and hormones, is an essential question in biomedicine and in the field of toxicology, and cannot be easily studied in humans. Thus, biomedical research has continuously relied on animal models for studying the impact of these compounds and attempted to 'translate' the results to humans. In this context, the SBV IMPROVER (Systems Biology Verification for Industrial Methodology for PROcess VErification in Research) collaborative initiative, which uses crowd-sourcing techniques to address fundamental questions in systems biology, invited scientists to deploy their own computational methodologies to make predictions on species translatability. A multi-layer systems biology dataset was generated that was comprised of phosphoproteomics, transcriptomics and cytokine data derived from normal human (NHBE) and rat (NRBE) bronchial epithelial cells exposed in parallel to more than 50 different stimuli under identical conditions. The present manuscript describes in detail the experimental settings, generation, processing and quality control analysis of the multi-layer omics dataset accessible in public repositories for further intra- and inter-species translation studies.

The species translation challenge—A systems biology perspective on human and rat bronchial epithelial cells

Science.gov (United States)

Poussin, Carine; Mathis, Carole; Alexopoulos, Leonidas G; Messinis, Dimitris E; Dulize, Rémi H J; Belcastro, Vincenzo; Melas, Ioannis N; Sakellaropoulos, Theodore; Rhrissorrakrai, Kahn; Bilal, Erhan; Meyer, Pablo; Talikka, Marja; Boué, Stéphanie; Norel, Raquel; Rice, John J; Stolovitzky, Gustavo; Ivanov, Nikolai V; Peitsch, Manuel C; Hoeng, Julia

2014-01-01

The biological responses to external cues such as drugs, chemicals, viruses and hormones, is an essential question in biomedicine and in the field of toxicology, and cannot be easily studied in humans. Thus, biomedical research has continuously relied on animal models for studying the impact of these compounds and attempted to ‘translate’ the results to humans. In this context, the SBV IMPROVER (Systems Biology Verification for Industrial Methodology for PROcess VErification in Research) collaborative initiative, which uses crowd-sourcing techniques to address fundamental questions in systems biology, invited scientists to deploy their own computational methodologies to make predictions on species translatability. A multi-layer systems biology dataset was generated that was comprised of phosphoproteomics, transcriptomics and cytokine data derived from normal human (NHBE) and rat (NRBE) bronchial epithelial cells exposed in parallel to more than 50 different stimuli under identical conditions. The present manuscript describes in detail the experimental settings, generation, processing and quality control analysis of the multi-layer omics dataset accessible in public repositories for further intra- and inter-species translation studies. PMID:25977767

Ab Initio Calculations of the Electronic Structures and Biological Functions of Protein Molecules

Science.gov (United States)

Zheng, Haoping

2003-04-01

The self-consistent cluster-embedding (SCCE) calculation method reduces the computational effort from M3 to about M1 (M is the number of atoms in the system) with unchanged calculation precision. So the ab initio, all-electron calculation of the electronic structure and biological function of protein molecule becomes a reality, which will promote new proteomics considerably. The calculated results of two real protein molecules, the trypsin inhibitor from the seeds of squash Cucurbita maxima (CMTI-I, 436 atoms) and the Ascaris trypsin inhibitor (912 atoms, two three-dimensional structures), are presented. The reactive sites of the inhibitors are determined and explained. The precision of structure determination of inhibitors are tested theoretically.

Colloquium paper: uniquely human evolution of sialic acid genetics and biology.

Science.gov (United States)

Varki, Ajit

2010-05-11

Darwinian evolution of humans from our common ancestors with nonhuman primates involved many gene-environment interactions at the population level, and the resulting human-specific genetic changes must contribute to the "Human Condition." Recent data indicate that the biology of sialic acids (which directly involves less than 60 genes) shows more than 10 uniquely human genetic changes in comparison with our closest evolutionary relatives. Known outcomes are tissue-specific changes in abundant cell-surface glycans, changes in specificity and/or expression of multiple proteins that recognize these glycans, and novel pathogen regimes. Specific events include Alu-mediated inactivation of the CMAH gene, resulting in loss of synthesis of the Sia N-glycolylneuraminic acid (Neu5Gc) and increase in expression of the precursor N-acetylneuraminic acid (Neu5Ac); increased expression of alpha2-6-linked Sias (likely because of changed expression of ST6GALI); and multiple changes in SIGLEC genes encoding Sia-recognizing Ig-like lectins (Siglecs). The last includes binding specificity changes (in Siglecs -5, -7, -9, -11, and -12); expression pattern changes (in Siglecs -1, -5, -6, and -11); gene conversion (SIGLEC11); and deletion or pseudogenization (SIGLEC13, SIGLEC14, and SIGLEC16). A nongenetic outcome of the CMAH mutation is human metabolic incorporation of foreign dietary Neu5Gc, in the face of circulating anti-Neu5Gc antibodies, generating a novel "xeno-auto-antigen" situation. Taken together, these data suggest that both the genes associated with Sia biology and the related impacts of the environment comprise a relative "hot spot" of genetic and physiological changes in human evolution, with implications for uniquely human features both in health and disease.

Comparative systems biology between human and animal models based on next-generation sequencing methods.

Science.gov (United States)

Zhao, Yu-Qi; Li, Gong-Hua; Huang, Jing-Fei

2013-04-01

Animal models provide myriad benefits to both experimental and clinical research. Unfortunately, in many situations, they fall short of expected results or provide contradictory results. In part, this can be the result of traditional molecular biological approaches that are relatively inefficient in elucidating underlying molecular mechanism. To improve the efficacy of animal models, a technological breakthrough is required. The growing availability and application of the high-throughput methods make systematic comparisons between human and animal models easier to perform. In the present study, we introduce the concept of the comparative systems biology, which we define as "comparisons of biological systems in different states or species used to achieve an integrated understanding of life forms with all their characteristic complexity of interactions at multiple levels". Furthermore, we discuss the applications of RNA-seq and ChIP-seq technologies to comparative systems biology between human and animal models and assess the potential applications for this approach in the future studies.

Applied Developmental Biology: Making Human Pancreatic Beta Cells for Diabetics.

Science.gov (United States)

Melton, Douglas A

2016-01-01

Understanding the genes and signaling pathways that determine the differentiation and fate of a cell is a central goal of developmental biology. Using that information to gain mastery over the fates of cells presents new approaches to cell transplantation and drug discovery for human diseases including diabetes. © 2016 Elsevier Inc. All rights reserved.

Integrating phenotypic data from electronic patient records with molecular level systems biology

DEFF Research Database (Denmark)

Brunak, Søren

2011-01-01

Electronic patient records remain a rather unexplored, but potentially rich data source for discovering correlations between diseases. We describe a general approach for gathering phenotypic descriptions of patients from medical records in a systematic and non-cohort dependent manner. By extracti...... Classification of Disease ontology and is therefore in principle language independent. As a use case we show how records from a Danish psychiatric hospital lead to the identification of disease correlations, which subsequently are mapped to systems biology frameworks....

Determination of azide in biological fluids by use of electron paramagnetic resonance

International Nuclear Information System (INIS)

Minakata, Kayoko; Suzuki, Osamu

2005-01-01

A simple and sensitive method has been developed for the determination of azide ion (N 3 - ) in biological fluids and beverages. The procedure was based on the formation of a ternary complex Cu(N 3 ) 2 (4-methylpyridine) x in benzene, followed by its detection by electron paramagnetic resonance. The complex in benzene showed a characteristic four-peak hyperfine structure with a g-value of 2.115 at room temperature. Cu 2+ reacted with N 3 - most strongly among common metals found in biological fluids. Several anions and metal ions in biological fluids did not interfere with the determination of N 3 - in the presence of large amounts of Cu 2+ and oxidants. In the present method, N 3 - at the concentration from 5 μM to 2 mM in 100 μl solution could be determined with the detection limit of 20 ng. The recoveries were more than 95% for N 3 - added to 100 μl of blood, urine, milk and beverages at 200 μM. Our method is recommendable because it takes less than 10 min to determine N 3 - and the produced complex is quite stable

The Mathematical Biology of Human Infections

Directory of Open Access Journals (Sweden)

Martin A. Nowak

1999-12-01

Full Text Available Humans are constant victims of infectious diseases. Biomedical research during this century has led to important insights into the molecular details of immune defense. Yet, many questions relating to disease require a quantitative understanding of the complex systems that arise from the nonlinear interactions between populations of immune cells and infectious agents. Exploration of such questions has lead to a newly emerging field of mathematical biology describing the spread of infectious agents both within and between infected individuals. This essay will discuss simple and complex models of evolution, and the propagation of virus and prion infections. Such models provide new perspectives for our understanding of infectious disease and provide guidelines for interpreting experimental observation; they also define what needs to be measured to improve understanding.

Dimeric ligands for GPCRs involved in human reproduction : synthesis and biological evaluation

NARCIS (Netherlands)

Bonger, Kimberly Michelle

2008-01-01

Dimeric ligands for G-protein coupled receptors that are involved in human reproduction, namely the gonadotropin releasing hormone receptor, the luteinizing hormone receptor and the follicle-stimulating hormone receptor, were synthesized and biologically evaluated.

75 FR 33312 - Indexing Structured Product Labeling for Human Prescription Drug and Biological Products; Request...

Science.gov (United States)

2010-06-11

...] Indexing Structured Product Labeling for Human Prescription Drug and Biological Products; Request for... Biologics Evaluation and Research (CBER) are indexing certain categories of information in product labeling for use as terms to search repositories of approved prescription medical product structured product...

Electron Bio-Imaging Centre (eBIC): the UK national research facility for biological electron microscopy.

Science.gov (United States)

Clare, Daniel K; Siebert, C Alistair; Hecksel, Corey; Hagen, Christoph; Mordhorst, Valerie; Grange, Michael; Ashton, Alun W; Walsh, Martin A; Grünewald, Kay; Saibil, Helen R; Stuart, David I; Zhang, Peijun

2017-06-01

The recent resolution revolution in cryo-EM has led to a massive increase in demand for both time on high-end cryo-electron microscopes and access to cryo-electron microscopy expertise. In anticipation of this demand, eBIC was set up at Diamond Light Source in collaboration with Birkbeck College London and the University of Oxford, and funded by the Wellcome Trust, the UK Medical Research Council (MRC) and the Biotechnology and Biological Sciences Research Council (BBSRC) to provide access to high-end equipment through peer review. eBIC is currently in its start-up phase and began by offering time on a single FEI Titan Krios microscope equipped with the latest generation of direct electron detectors from two manufacturers. Here, the current status and modes of access for potential users of eBIC are outlined. In the first year of operation, 222 d of microscope time were delivered to external research groups, with 95 visits in total, of which 53 were from unique groups. The data collected have generated multiple high- to intermediate-resolution structures (2.8-8 Å), ten of which have been published. A second Krios microscope is now in operation, with two more due to come online in 2017. In the next phase of growth of eBIC, in addition to more microscope time, new data-collection strategies and sample-preparation techniques will be made available to external user groups. Finally, all raw data are archived, and a metadata catalogue and automated pipelines for data analysis are being developed.

Chimeric animal models in human stem cell biology.

Science.gov (United States)

Glover, Joel C; Boulland, Jean-Luc; Halasi, Gabor; Kasumacic, Nedim

2009-01-01

The clinical use of stem cells for regenerative medicine is critically dependent on preclinical studies in animal models. In this review we examine some of the key issues and challenges in the use of animal models to study human stem cell biology-experimental standardization, body size, immunological barriers, cell survival factors, fusion of host and donor cells, and in vivo imaging and tracking. We focus particular attention on the various imaging modalities that can be used to track cells in living animals, comparing their strengths and weaknesses and describing technical developments that are likely to lead to new opportunities for the dynamic assessment of stem cell behavior in vivo. We then provide an overview of some of the most commonly used animal models, their advantages and disadvantages, and examples of their use for xenotypic transplantation of human stem cells, with separate reviews of models involving rodents, ungulates, nonhuman primates, and the chicken embryo. As the use of human somatic, embryonic, and induced pluripotent stem cells increases, so too will the range of applications for these animal models. It is likely that increasingly sophisticated uses of human/animal chimeric models will be developed through advances in genetic manipulation, cell delivery, and in vivo imaging.

Doppler-broadening of positron annihilation in a biological environment

International Nuclear Information System (INIS)

Torrisi, L.; La Mela, C.; Catania, Univ.

1997-01-01

The aim of this study was to investigate the Doppler effect of the 511 keV γ peak from positron annihilation in biological matter: The broadening of the annihilation peak is due to positron annihilation with electrons that have high momentum. In aqueous solutions annihilation depends on the temperature and it is linked positronium formation. Measurements in vivo, on human brain, were taken during the diagnosis of positron emission tomography (PET) on healthy patients by injecting them with the beta emitter of short lifetime 18F . The Doppler-broadening in biological tissues rich in water content decreased significantly compared to biological solutions and water

The functional biology of human milk oligosaccharides.

Science.gov (United States)

Bode, Lars

2015-11-01

Human milk oligosaccharides (HMOs) are a group of complex sugars that are highly abundant in human milk, but currently not present in infant formula. More than a hundred different HMOs have been identified so far. The amount and composition of HMOs are highly variable between women, and each structurally defined HMO might have a distinct functionality. HMOs are not digested by the infant and serve as metabolic substrates for select microbes, contributing to shape the infant gut microbiome. HMOs act as soluble decoy receptors that block the attachment of viral, bacterial or protozoan parasite pathogens to epithelial cell surface sugars, which may help prevent infectious diseases in the gut and also the respiratory and urinary tracts. HMOs are also antimicrobials that act as bacteriostatic or bacteriocidal agents. In addition, HMOs alter host epithelial and immune cell responses with potential benefits for the neonate. The article reviews current knowledge as well as future challenges and opportunities related to the functional biology of HMOs. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Biological effects of space radiation on human cells. History, advances and outcomes

International Nuclear Information System (INIS)

Maalouf, M.; Foray, N.; Durante, M.

2011-01-01

Exposure to radiation is one of the main concerns for space exploration by humans. By focusing deliberately on the works performed on human cells, we endeavored to review, decade by decade, the technological developments and conceptual advances of space radiation biology. Despite considerable efforts, the cancer and the toxicity risks remain to be quantified: the nature and the frequency of secondary heavy ions need to be better characterized in order to estimate their contribution to the dose and to the final biological response; the diversity of radiation history of each astronaut and the impact of individual susceptibility make very difficult any epidemiological analysis for estimating hazards specifically due to space radiation exposure. Cytogenetic data undoubtedly revealed that space radiation exposure produce significant damage in cells. However, our knowledge of the basic mechanisms specific to low-dose, to repeated doses and to adaptive response is still poor. The application of new radiobiological techniques, like immunofluorescence, and the use of human tissue models different from blood, like skin fibroblasts, may help in clarifying all the above items. (author)

Electronic cigarettes: incorporating human factors engineering into risk assessments

OpenAIRE

Yang, Ling; Rudy, Susan F; Cheng, James M; Durmowicz, Elizabeth L

2014-01-01

Objective A systematic review was conducted to evaluate the impact of human factors (HF) on the risks associated with electronic cigarettes (e-cigarettes) and to identify research gaps. HF is the evaluation of human interactions with products and includes the analysis of user, environment and product complexity. Consideration of HF may mitigate known and potential hazards from the use and misuse of a consumer product, including e-cigarettes. Methods Five databases were searched through Januar...

Department of Health and Human Services Semiannual Regulatory Agenda

Science.gov (United States)

2010-04-26

...-AB58 Specifications, and Certification Criteria for Electronic Health Record Technology (Rulemaking... Electronic Submission of Data From Studies Evaluating Human Drugs and Biologics....... 0910-AC52 137 Over-the... 147 Cigars Subject to the Family Smoking Prevention and Tobacco Control Act 0910-AG38 Food and Drug...

Advances in Structural Biology and the Application to Biological Filament Systems.

Science.gov (United States)

Popp, David; Koh, Fujiet; Scipion, Clement P M; Ghoshdastider, Umesh; Narita, Akihiro; Holmes, Kenneth C; Robinson, Robert C

2018-04-01

Structural biology has experienced several transformative technological advances in recent years. These include: development of extremely bright X-ray sources (microfocus synchrotron beamlines and free electron lasers) and the use of electrons to extend protein crystallography to ever decreasing crystal sizes; and an increase in the resolution attainable by cryo-electron microscopy. Here we discuss the use of these techniques in general terms and highlight their application for biological filament systems, an area that is severely underrepresented in atomic resolution structures. We assemble a model of a capped tropomyosin-actin minifilament to demonstrate the utility of combining structures determined by different techniques. Finally, we survey the methods that attempt to transform high resolution structural biology into more physiological environments, such as the cell. Together these techniques promise a compelling decade for structural biology and, more importantly, they will provide exciting discoveries in understanding the designs and purposes of biological machines. © 2018 The Authors. BioEssays Published by WILEY Periodicals, Inc.

Quantitative analysis of biological fluids by electron probe and X ray spectrometry

International Nuclear Information System (INIS)

Girod, Chantal

1986-01-01

In order to know the kidney normal operation and to have an insight on cellular transport mechanisms and hormonal regulations at the nephron level, a technique based on the use of an electron probe has been developed for the elemental analysis of micro-volumes of biological fluids. This academic document reports applications of this technique on animals on which such fluids have been sampled at different levels of the nephron. As these samples are available in too small volumes to be dosed by conventional methods, they have been quantitatively analysed by using an electronic probe based analyser in order to determine concentrations of all elements with an atomic number greater than that of carbon. After a presentation of the implemented method and hardware, the author thus describes how an analysis is performed, and reports and discusses an example (analysis conditions, data acquisition, data processing, minimum detectable concentration, reasons for measurement scattering)

Photo-induced regeneration of hormones by electron transfer processes: Potential biological and medical consequences

Science.gov (United States)

Getoff, Nikola; Hartmann, Johannes; Schittl, Heike; Gerschpacher, Marion; Quint, Ruth Maria

2011-08-01

Based on the previous results concerning electron transfer processes in biological substances, it was of interest to investigate if hormone transients resulting by e.g. electron emission can be regenerated. The presented results prove for the first time that the hormone transients originating by the electron emission process can be successfully regenerated by the transfer of electrons from a potent electron donor, such as vitamin C (VitC). Investigations were performed using progesterone (PRG), testosterone (TES) and estrone (E1) as representatives of hormones. By irradiation with monochromatic UV light (λ=254 nm) in a media of 40% water and 60% ethanol, the degradation as well as the regeneration of the hormones was studied with each hormone individually and in the mixture with VitC as a function of the absorbed UV dose, using HPLC. Calculated from the obtained initial yields, the determined regeneration of PRG amounted to 52.7%, for TES to 58.6% and for E1 to 90.9%. The consumption of VitC was determined in the same way. The reported results concerning the regeneration of hormones by the transfer of electrons from an electron donor offer a new, promising method for the therapy with hormones. As a consequence of the regeneration of hormones, a decreased formation of carcinogenic metabolites is expected.

Photo-induced regeneration of hormones by electron transfer processes: Potential biological and medical consequences

Energy Technology Data Exchange (ETDEWEB)

Getoff, Nikola, E-mail: nikola.getoff@univie.ac.a [Section of Radiation Biology, Faculty of Life Sciences, University of Vienna, A-1090 Vienna (Austria); Hartmann, Johannes [Department of Gynecologic Endocrinology and Reproduction, Medical University of Vienna, A-1090 Vienna (Austria); Schittl, Heike [Section of Radiation Biology, Faculty of Life Sciences, University of Vienna, A-1090 Vienna (Austria); Gerschpacher, Marion [Department of Gynecologic Endocrinology and Reproduction, Medical University of Vienna, A-1090 Vienna (Austria); Quint, Ruth Maria [Section of Radiation Biology, Faculty of Life Sciences, University of Vienna, A-1090 Vienna (Austria)

2011-08-15

Based on the previous results concerning electron transfer processes in biological substances, it was of interest to investigate if hormone transients resulting by e.g. electron emission can be regenerated. The presented results prove for the first time that the hormone transients originating by the electron emission process can be successfully regenerated by the transfer of electrons from a potent electron donor, such as vitamin C (VitC). Investigations were performed using progesterone (PRG), testosterone (TES) and estrone (E1) as representatives of hormones. By irradiation with monochromatic UV light ({lambda}=254 nm) in a media of 40% water and 60% ethanol, the degradation as well as the regeneration of the hormones was studied with each hormone individually and in the mixture with VitC as a function of the absorbed UV dose, using HPLC. Calculated from the obtained initial yields, the determined regeneration of PRG amounted to 52.7%, for TES to 58.6% and for E1 to 90.9%. The consumption of VitC was determined in the same way. The reported results concerning the regeneration of hormones by the transfer of electrons from an electron donor offer a new, promising method for the therapy with hormones. As a consequence of the regeneration of hormones, a decreased formation of carcinogenic metabolites is expected.

Photo-induced regeneration of hormones by electron transfer processes: Potential biological and medical consequences

International Nuclear Information System (INIS)

Getoff, Nikola; Hartmann, Johannes; Schittl, Heike; Gerschpacher, Marion; Quint, Ruth Maria

2011-01-01

Based on the previous results concerning electron transfer processes in biological substances, it was of interest to investigate if hormone transients resulting by e.g. electron emission can be regenerated. The presented results prove for the first time that the hormone transients originating by the electron emission process can be successfully regenerated by the transfer of electrons from a potent electron donor, such as vitamin C (VitC). Investigations were performed using progesterone (PRG), testosterone (TES) and estrone (E1) as representatives of hormones. By irradiation with monochromatic UV light (λ=254 nm) in a media of 40% water and 60% ethanol, the degradation as well as the regeneration of the hormones was studied with each hormone individually and in the mixture with VitC as a function of the absorbed UV dose, using HPLC. Calculated from the obtained initial yields, the determined regeneration of PRG amounted to 52.7%, for TES to 58.6% and for E1 to 90.9%. The consumption of VitC was determined in the same way. The reported results concerning the regeneration of hormones by the transfer of electrons from an electron donor offer a new, promising method for the therapy with hormones. As a consequence of the regeneration of hormones, a decreased formation of carcinogenic metabolites is expected.

Compressed sensing electron tomography of needle-shaped biological specimens – Potential for improved reconstruction fidelity with reduced dose

Energy Technology Data Exchange (ETDEWEB)

Saghi, Zineb, E-mail: saghizineb@gmail.com [Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS (United Kingdom); Divitini, Giorgio [Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS (United Kingdom); Winter, Benjamin [Center for Nanoanalysis and Electron Microscopy (CENEM), Friedrich-Alexander-Universität Erlangen-Nürnberg, Cauerstraße 6, 91058 Erlangen (Germany); Leary, Rowan [Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS (United Kingdom); Spiecker, Erdmann [Center for Nanoanalysis and Electron Microscopy (CENEM), Friedrich-Alexander-Universität Erlangen-Nürnberg, Cauerstraße 6, 91058 Erlangen (Germany); Ducati, Caterina [Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS (United Kingdom); Midgley, Paul A., E-mail: pam33@cam.ac.uk [Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS (United Kingdom)

2016-01-15

Electron tomography is an invaluable method for 3D cellular imaging. The technique is, however, limited by the specimen geometry, with a loss of resolution due to a restricted tilt range, an increase in specimen thickness with tilt, and a resultant need for subjective and time-consuming manual segmentation. Here we show that 3D reconstructions of needle-shaped biological samples exhibit isotropic resolution, facilitating improved automated segmentation and feature detection. By using scanning transmission electron tomography, with small probe convergence angles, high spatial resolution is maintained over large depths of field and across the tilt range. Moreover, the application of compressed sensing methods to the needle data demonstrates how high fidelity reconstructions may be achieved with far fewer images (and thus greatly reduced dose) than needed by conventional methods. These findings open the door to high fidelity electron tomography over critically relevant length-scales, filling an important gap between existing 3D cellular imaging techniques. - Highlights: • On-axis electron tomography of a needle-shaped biological sample is presented. • A reconstruction with isotropic resolution is achieved. • Compressed sensing methods are compared to conventional reconstruction algorithms. • High fidelity reconstructions are achieved with greatly undersampled datasets.

Compressed sensing electron tomography of needle-shaped biological specimens – Potential for improved reconstruction fidelity with reduced dose

International Nuclear Information System (INIS)

Saghi, Zineb; Divitini, Giorgio; Winter, Benjamin; Leary, Rowan; Spiecker, Erdmann; Ducati, Caterina; Midgley, Paul A.

2016-01-01

Electron tomography is an invaluable method for 3D cellular imaging. The technique is, however, limited by the specimen geometry, with a loss of resolution due to a restricted tilt range, an increase in specimen thickness with tilt, and a resultant need for subjective and time-consuming manual segmentation. Here we show that 3D reconstructions of needle-shaped biological samples exhibit isotropic resolution, facilitating improved automated segmentation and feature detection. By using scanning transmission electron tomography, with small probe convergence angles, high spatial resolution is maintained over large depths of field and across the tilt range. Moreover, the application of compressed sensing methods to the needle data demonstrates how high fidelity reconstructions may be achieved with far fewer images (and thus greatly reduced dose) than needed by conventional methods. These findings open the door to high fidelity electron tomography over critically relevant length-scales, filling an important gap between existing 3D cellular imaging techniques. - Highlights: • On-axis electron tomography of a needle-shaped biological sample is presented. • A reconstruction with isotropic resolution is achieved. • Compressed sensing methods are compared to conventional reconstruction algorithms. • High fidelity reconstructions are achieved with greatly undersampled datasets.

Magnetic iron oxide nanoparticles grafted N-isopropylacrylamide/chitosan copolymer for the extraction and determination of letrozole in human biological samples.

Science.gov (United States)

Khalaj Moazen, Mercede; Ahmad Panahi, Homayon

2017-03-01

Magnetic iron oxide nanoparticles are used for the extraction of a drug from an aqueous solution. In the current study, the magnetic iron oxide nanoparticles were synthesized via a facile coprecipitation approach, and then modified by (3-mercaptopropyl)trimethoxysilane followed by grafting thermosensitive polymer N-isopropylacrylamide and biopolymer chitosan. Structure, morphology, size, thermal resistance, specific surface area, and magnetic properties of the grafted nanosorbent were characterized by using Fourier transform infrared spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, elemental analysis, thermogravimetric analysis, specific surface area analysis and vibrating sample magnetometry. The effective parameters on sorption/desorption of letrozole on grafted magnetic nanosorbent were evaluated. The best sorption of letrozole via the grafted nanosorbent occurred at 20°C at an optimum pH of 7. The extraction of trace letrozole in human biological fluids is investigated and revealed 89.1 and 97.8% recovery in plasma and urine, respectively. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Human genome project: revolutionizing biology through leveraging technology

Science.gov (United States)

Dahl, Carol A.; Strausberg, Robert L.

1996-04-01

The Human Genome Project (HGP) is an international project to develop genetic, physical, and sequence-based maps of the human genome. Since the inception of the HGP it has been clear that substantially improved technology would be required to meet the scientific goals, particularly in order to acquire the complete sequence of the human genome, and that these technologies coupled with the information forthcoming from the project would have a dramatic effect on the way biomedical research is performed in the future. In this paper, we discuss the state-of-the-art for genomic DNA sequencing, technological challenges that remain, and the potential technological paths that could yield substantially improved genomic sequencing technology. The impact of the technology developed from the HGP is broad-reaching and a discussion of other research and medical applications that are leveraging HGP-derived DNA analysis technologies is included. The multidisciplinary approach to the development of new technologies that has been successful for the HGP provides a paradigm for facilitating new genomic approaches toward understanding the biological role of functional elements and systems within the cell, including those encoded within genomic DNA and their molecular products.

Biological Activity Alterations of Human Amniotic Membrane Pre and Post Irradiation Tissue Banking.

Science.gov (United States)

Nemr, Waleed; Bashandy, A S; Araby, Eman; Khamiss, O

Innate immunity of Human Amniotic Membrane (HAM) and its highly active secretome that rich with various types of growth factors and anti-inflammatory substances proposed it as a promising material for many medical studies and applications. This study evaluate the biological activity of cultivated HAM pre and post tissue banking process in which freeze-dried HAM was sterilized by 25 KGray (kGy) dose of γ radiation. The HAM's antimicrobial activity, viability, growth of isolated human amniotic epithelial cells (HAECs), hematopoietic stimulation of co-cultivated murine bone marrow cells (mammalian model), scaffold efficiency for fish brain building up (non-mammalian model) and self re-epithelialization after trypsin denuding treatment were examined as supposed biological activity features. Native HAM revealed viability indications and was active to kill all tested microorganisms; 6 bacterial species (3 Gram-positive and 3 Gram-negative) and Candida albicans as a pathogenic fungus. Also, HAM activity promoted colony formation of murine hematopoietic cells, Tilapia nilotica brain fragment building-up and self re-epithelialization after trypsin treatment. In contrary, radiation-based tissue banking of HAM caused HAM cellular death and consequently lacked almost all of examined biological activity features. Viable HAM was featured with biological activity than fixed HAM prepared by irradiation tissue banking.

Transmission microscopy of unmodified biological materials: comparative radiation dosages with electrons and ultrasoft X-ray photons

International Nuclear Information System (INIS)

Sayre, D.; Feder, R.; Spiller, E.; Kirz, J.; Kim, D.M.

1977-01-01

The minimum radiation dosage in a specimen consistent with transmission microscopy at resolution d and specimen thickness t is calculated for model specimens resembling biological materials in their natural state. The calculations cover 10 4 -10 7 eV electrons and 1.3-90 A photons in a number of microscopy modes. The results indicate that over a considerable part of the (t,d)-plane transmission microscopy on such specimens can be carried out at lower dosage with photons than with electrons. Estimates of the maximum resolutions obtainable with electrons and photons, consistent with structural survival of the specimen, are obtained, as are data on optimal operating conditions for microscopy with the two particles

New frontiers in human cell biology and medicine: can pluripotent stem cells deliver?

Science.gov (United States)

Goldstein, Lawrence S B

2012-11-12

Human pluripotent stem cells provide enormous opportunities to treat disease using cell therapy. But human stem cells can also drive biomedical and cell biological discoveries in a human model system, which can be directly linked to understanding disease or developing new therapies. Finally, rigorous scientific studies of these cells can and should inform the many science and medical policy issues that confront the translation of these technologies to medicine. In this paper, I discuss these issues using amyotrophic lateral sclerosis as an example.

Chitosan to Connect Biology to Electronics: Fabricating the Bio-Device Interface and Communicating Across This Interface

Directory of Open Access Journals (Sweden)

Eunkyoung Kim

2014-12-01

Full Text Available Individually, advances in microelectronics and biology transformed the way we live our lives. However, there remain few examples in which biology and electronics have been interfaced to create synergistic capabilities. We believe there are two major challenges to the integration of biological components into microelectronic systems: (i assembly of the biological components at an electrode address, and (ii communication between the assembled biological components and the underlying electrode. Chitosan possesses a unique combination of properties to meet these challenges and serve as an effective bio-device interface material. For assembly, chitosan’s pH-responsive film-forming properties allow it to “recognize” electrode-imposed signals and respond by self-assembling as a stable hydrogel film through a cathodic electrodeposition mechanism. A separate anodic electrodeposition mechanism was recently reported and this also allows chitosan hydrogel films to be assembled at an electrode address. Protein-based biofunctionality can be conferred to electrodeposited films through a variety of physical, chemical and biological methods. For communication, we are investigating redox-active catechol-modified chitosan films as an interface to bridge redox-based communication between biology and an electrode. Despite significant progress over the last decade, many questions still remain which warrants even deeper study of chitosan’s structure, properties, and functions.

Graphene as a transparent conductive support for studying biological molecules by transmission electron microscopy

International Nuclear Information System (INIS)

Nair, R. R.; Anissimova, S.; Novoselov, K. S.; Blake, P.; Blake, J. R.; Geim, A. K.; Zan, R.; Bangert, U.; Golovanov, A. P.; Morozov, S. V.; Latychevskaia, T.

2010-01-01

We demonstrate the application of graphene as a support for imaging individual biological molecules in transmission electron microscope (TEM). A simple procedure to produce free-standing graphene membranes has been designed. Such membranes are extremely robust and can support practically any submicrometer object. Tobacco mosaic virus has been deposited on graphene samples and observed in a TEM. High contrast has been achieved even though no staining has been applied.

Effectiveness of Biology-Based Methods for Inhibiting Orthodontic Tooth Movement. A Systematic Review.

Science.gov (United States)

Cadenas de Llano-Pérula, M; Yañez-Vico, R M; Solano-Reina, E; Palma-Fernandez, J C; Iglesias-Linares, A

Several experimental studies in the literature have tested different biology-based methods for inhibiting or decreasing orthodontic tooth movement (OTM) in humans. This systematic review investigated the effects of these interventions on the rate of tooth movement. Electronic [MedLine; SCOPUS; Cochrane Library; OpenGrey;Web of Science] and manual searches were conducted up to January 26th, 2016 in order to identify publications of clinical trials that compared the decreasing or inhibiting effects of different biology-based methods over OTM in humans. A primary outcome (rate of OTM deceleration/inhibition) and a number of secondary outcomes were examined (clinical applicability, orthodontic force used, possible side effects). Two reviewers selected the studies complying with the eligibility criteria (PICO format) and assessed risk of bias [Cochrane Collaboration's tool]. Data collection and analysis were performed following the Cochrane recommendations. From the initial electronic search, 3726 articles were retrieved and 5 studies were finally included. Two types of biology-based techniques used to reduce the rate of OTM in humans were described: pharmacological and low-level laser therapy. In the first group, human Relaxin was compared to a placebo and administered orally. It was described as having no effect on the inhibition of OTM in humans after 32 days, while the drug tenoxicam, injected locally, inhibited the rate of OTM by up to 10% in humans after 42 days. In the second group, no statistically significant differences were reported, compared to placebo, for the rate of inhibition of OTM in humans after 90 days of observation when a 860 nm continuous wave GaAlA slow-level laser was used. The currently available data do not allow us to draw definitive conclusions about the use of various pharmacological substances and biology-based therapies in humans able to inhibit or decrease the OTM rate. There is an urgent need for more sound well-designed randomized

MDI Biological Laboratory Arsenic Summit: Approaches to Limiting Human Exposure to Arsenic

OpenAIRE

Stanton, Bruce A.

2015-01-01

This report is the outcome of the meeting: “Environmental and Human Health Consequences of Arsenic”, held at the MDI Biological Laboratory in Salisbury Cove, Maine, August 13–15, 2014. Human exposure to arsenic represents a significant health problem worldwide that requires immediate attention according to the World Health Organization (WHO). One billion people are exposed to arsenic in food and more than 200 million people ingest arsenic via drinking water at concentrations greater than inte...

Scanning electron microscopy and electron probe microanalyses of the crystalline components of human and animal dental calculi

International Nuclear Information System (INIS)

LeGeros, R.Z.; Orly, I.; LeGeros, J.P.; Gomez, C.; Kazimiroff, J.; Tarpley, T.; Kerebel, B.

1988-01-01

A review of the use of scanning electron microscopy (SEM) and electron probe microanalyses in the study of dental calculus showed that such studies provided confirmatory and supplementary data on the morphological features of human dental calculi but gave only limited information on the identity of the crystalline or inorganic components. This study aimed to explore the potential of combined SEM and microanalyses in the identification of the crystalline components of the human and animal dental calculi. Human and animal calculi were analyzed. Identification of the crystalline components were made based on the combined information of the morphology (SEM) and Ca/P molar ratios of the crystals with the morphology and Ca/P molar ratio of synthetic calcium phosphates (brushite or DCPD; octacalcium phosphate, OCP; Mg-substituted whitlockite, beta-TCMP; CO 3 -substituted apatite, (CHA); and calcite. SEM showed similarities in morphological features of human and animal dental calculi but differences in the forms of crystals present. Microanalyses and crystal morphology data suggested the presence of CaCO 3 (calcite) and CHA in the animal (cat, dog, tiger) and of OCP, beta-TCMP and CHA in human dental calculi. X-ray diffraction and infrared (IR) absorption analyses confirmed these results. This exploratory study demonstrated that by taking into consideration what is known about the crystalline components of human and animal dental calculi, combined SEM and microanalyses can provide qualitative identification

Biological responses of progestogen metabolites in normal and cancerous human breast.

Science.gov (United States)

Pasqualini, Jorge R; Chetrite, Gérard S

2010-12-01

At present, more than 200 progestogen molecules are available, but their biological response is a function of various factors: affinity to progesterone or other receptors, their structure, the target tissues considered, biological response, experimental conditions, dose, method of administration and metabolic transformations. Metabolic transformation is of huge importance because in various biological processes the metabolic product(s) not only control the activity of the maternal hormone but also have an important activity of its own. In this regard, it was observed that the 20-dihydro derivative of the progestogen dydrogesterone (Duphaston®) is significantly more active than the parent compound in inhibiting sulfatase and 17β-hydroxysteroid dehydrogenase in human breast cancer cells. Estrone sulfatase activity is also inhibited by norelgestromin, a norgestimate metabolite. Interesting information was obtained with a similar progestogen, tibolone, which is rapidly metabolized into the active 3α/3β-hydroxy and 4-ene metabolites. All these metabolites can inhibit sulfatase and 17β-hydroxysteroid dehydrogenase and stimulate sulfotransferase in human breast cancer cells. Another attractive aspect is the metabolic transformation of progesterone itself in human breast tissues. In the normal breast progesterone is mainly converted to 4-ene derivatives, whereas in the tumor tissue it is converted mostly to 5α-pregnane derivatives. 20α-Dihydroprogesterone is found mainly in normal breast tissue and possesses antiproliferative properties as well as the ability to act as an anti-aromatase agent. Consequently, this progesterone metabolite could be involved in the control of estradiol production in the normal breast and therefore implicated in one of the multifactorial mechanisms of the breast carcinogenesis process. In conclusion, a better understanding of both natural and synthetic hormone metabolic transformations and their control could potentially provide

Synthetic biology meets bioprinting: enabling technologies for humans on Mars (and Earth).

Science.gov (United States)

Rothschild, Lynn J

2016-08-15

Human exploration off planet is severely limited by the cost of launching materials into space and by re-supply. Thus materials brought from Earth must be light, stable and reliable at destination. Using traditional approaches, a lunar or Mars base would require either transporting a hefty store of metals or heavy manufacturing equipment and construction materials for in situ extraction; both would severely limit any other mission objectives. Long-term human space presence requires periodic replenishment, adding a massive cost overhead. Even robotic missions often sacrifice science goals for heavy radiation and thermal protection. Biology has the potential to solve these problems because life can replicate and repair itself, and perform a wide variety of chemical reactions including making food, fuel and materials. Synthetic biology enhances and expands life's evolved repertoire. Using organisms as feedstock, additive manufacturing through bioprinting will make possible the dream of producing bespoke tools, food, smart fabrics and even replacement organs on demand. This new approach and the resulting novel products will enable human exploration and settlement on Mars, while providing new manufacturing approaches for life on Earth. © 2016 The Author(s).

The Mouse Tumor Biology Database: A Comprehensive Resource for Mouse Models of Human Cancer.

Science.gov (United States)

Krupke, Debra M; Begley, Dale A; Sundberg, John P; Richardson, Joel E; Neuhauser, Steven B; Bult, Carol J

2017-11-01

Research using laboratory mice has led to fundamental insights into the molecular genetic processes that govern cancer initiation, progression, and treatment response. Although thousands of scientific articles have been published about mouse models of human cancer, collating information and data for a specific model is hampered by the fact that many authors do not adhere to existing annotation standards when describing models. The interpretation of experimental results in mouse models can also be confounded when researchers do not factor in the effect of genetic background on tumor biology. The Mouse Tumor Biology (MTB) database is an expertly curated, comprehensive compendium of mouse models of human cancer. Through the enforcement of nomenclature and related annotation standards, MTB supports aggregation of data about a cancer model from diverse sources and assessment of how genetic background of a mouse strain influences the biological properties of a specific tumor type and model utility. Cancer Res; 77(21); e67-70. ©2017 AACR . ©2017 American Association for Cancer Research.

THREE-DIMENSIONAL OBSERVATIONS ON THICK BIOLOGICAL SPECIMENS BY HIGH VOLTAGE ELECTRON MICROSCOPY

Directory of Open Access Journals (Sweden)

Tetsuji Nagata

2011-05-01

Full Text Available Thick biological specimens prepared as whole mount cultured cells or thick sections from embedded tissues were stained with histochemical reactions, such as thiamine pyrophosphatase, glucose-6-phosphatase, cytochrome oxidase, acid phosphatase, DAB reactions and radioautography, to observe 3-D ultrastructures of cell organelles producing stereo-pairs by high voltage electron microscopy at accerelating voltages of 400-1000 kV. The organelles demonstrated were Golgi apparatus, endoplasmic reticulum, mitochondria, lysosomes, peroxisomes, pinocytotic vesicles and incorporations of radioactive compounds. As the results, those cell organelles were observed 3- dimensionally and the relative relationships between these organelles were demonstrated.

Biological and social aspects of human sexual orientation: chemocommunicative hypothesis

Directory of Open Access Journals (Sweden)

Eugene V. Daev

2016-09-01

Full Text Available Failure to understand the role of biological and social factors in the formation of some socially important traits in humans can lead to the appearance of undue tension in interpersonal relationships. This is due to a distorted perception of man often unreliable information, its ambiguity due to the uncertainty of the terminology used and, as a consequence, the impossibility of its correct analysis. Using of term “sexual orientation” shows as a genetic understanding of the trait’s formation and data on sex formation control mechanisms may clarify and complement our knowledge on the subject. Under the theme chemocommunicative model is considered and its contribution to the formation of “sexual orientation” in humans.

Prostaglandins - universal biological regulators in the human body (literature review

Directory of Open Access Journals (Sweden)

О. V. Tymoshchuk

2018-02-01

Full Text Available Recently, researchers of different industries pay great attention to the problem of prostaglandins. Objective: to study and systematize the basic questions of structure, biological action and metabolism of prostaglandins in the human body and using their analogues in pharmacy through the domestic and foreign literature data analysis. Prostaglandins – biologically active substances which are similar in effect to hormones, but are synthesized in cells of different tissues. Prostaglandins as universal cellular mediators are widely distributed in the body, synthesized in small amounts in almost all tissues, have both local and systemic effects. For each prostaglandin there is a target organ. On chemical structure they are small molecules related to eicosanoids - a group of fat-like substances (lipids. Depending on the chemical structure prostaglandins are divided into series (A, B, C, D, E, F, G, H, I and J and three groups (1–3; type F isomers are to be indicated by additional letters α and β. Prostaglandins have an extremely wide range of physiological effects in the body and have three main functions: supporting, molecular, neurotransmitter. Most prostaglandins interact with specific receptors of plasma membranes, but some prostaglandins (group A can act without receptors. There is no stock of prostaglandins in the body, their life cycle is short, and they are quickly produced in response to biological stimulants exposure, have their effect in extremely small quantity and are rapidly inactivated in the bloodstream. Due to the extremely rapid breakdown of prostaglandins in the body they work near their place of secretion. Preparations of prostaglandins and their derivatives are used in experimental and clinical medicine for abortion and induction of labor, treatment of stomach ulcers, asthma, certain heart diseases, congenital heart defects in newborns, glaucoma, atherosclerosis, rheumatic and neurological diseases, kidney diseases, diabetes

Human biological monitoring as demonstrated by means of a heavy-metal polluted abandoned site; Human-Biomonitoring am Beispiel einer Schwermetallaltlast

Energy Technology Data Exchange (ETDEWEB)

Elison, M; Schulte-Hostede, S [GSF-Forschungzentrum fuer Umwelt und Gesundheit Neuherberg (Germany). Inst. fuer Oekologische Chemie

1998-12-31

Models for estimating exposure permit to make a rough assessment of the risk emanating from a contaminated area. But it must not be overlooked that such models are fraught with considerable weaknesses.- In studies such as the one described, concerned citizens should additionally be examined in order to obtain supplementary information and to aid interpretation. Such human biological monitoring makes sense only if the persons in question actually live in the contaminated areas, so that a higher exposure may reasonably be expected. Human biological monitoring is to help assess the inner exposure of human beings to pollutants emanating from the contaminated area. (orig./SR) [Deutsch] Mit Hilfe von Modellen zur Expositionsabschaetzung ist man nach den oben dargestellten Vorgehensweisen in der Lage, eine orientierende Bewertung des von einer kontaminierten Flaeche ausgehenden Risikos vorzunehmen. Dabei ist jedoch zu beruecksichtigen, dass solche Modelle mit erheblichen Schwachstellen belastet sind. Zur Ergaenzung und Interpretationshilfe sind bei Untersuchungen wie der hier vorgestellten auch Untersuchungen an den betroffenen Buergen vorzunehmen. Dieses Human-Biomonitoring hat nur dort einen Sinn, wo sichergestellt ist, dass die Menschen dort tatsaechlich auf belasteten Flaechen leben und damit eine erhoehte Belastung der Menschen anzunehmen ist. Das Human-Biomonitoring soll eine Abschaetzung der inneren Belastung des Menschen mit Schadstoffen, die von der kontaminierten Flaeche herruehren, ermoeglichen. (orig./SR)

Human biological monitoring as demonstrated by means of a heavy-metal polluted abandoned site; Human-Biomonitoring am Beispiel einer Schwermetallaltlast

Energy Technology Data Exchange (ETDEWEB)

Elison, M.; Schulte-Hostede, S. [GSF-Forschungzentrum fuer Umwelt und Gesundheit Neuherberg (Germany). Inst. fuer Oekologische Chemie

1997-12-31

Models for estimating exposure permit to make a rough assessment of the risk emanating from a contaminated area. But it must not be overlooked that such models are fraught with considerable weaknesses.- In studies such as the one described, concerned citizens should additionally be examined in order to obtain supplementary information and to aid interpretation. Such human biological monitoring makes sense only if the persons in question actually live in the contaminated areas, so that a higher exposure may reasonably be expected. Human biological monitoring is to help assess the inner exposure of human beings to pollutants emanating from the contaminated area. (orig./SR) [Deutsch] Mit Hilfe von Modellen zur Expositionsabschaetzung ist man nach den oben dargestellten Vorgehensweisen in der Lage, eine orientierende Bewertung des von einer kontaminierten Flaeche ausgehenden Risikos vorzunehmen. Dabei ist jedoch zu beruecksichtigen, dass solche Modelle mit erheblichen Schwachstellen belastet sind. Zur Ergaenzung und Interpretationshilfe sind bei Untersuchungen wie der hier vorgestellten auch Untersuchungen an den betroffenen Buergen vorzunehmen. Dieses Human-Biomonitoring hat nur dort einen Sinn, wo sichergestellt ist, dass die Menschen dort tatsaechlich auf belasteten Flaechen leben und damit eine erhoehte Belastung der Menschen anzunehmen ist. Das Human-Biomonitoring soll eine Abschaetzung der inneren Belastung des Menschen mit Schadstoffen, die von der kontaminierten Flaeche herruehren, ermoeglichen. (orig./SR)

Biosocial Conservation: Integrating Biological and Ethnographic Methods to Study Human-Primate Interactions.

Science.gov (United States)

Setchell, Joanna M; Fairet, Emilie; Shutt, Kathryn; Waters, Siân; Bell, Sandra

2017-01-01

Biodiversity conservation is one of the grand challenges facing society. Many people interested in biodiversity conservation have a background in wildlife biology. However, the diverse social, cultural, political, and historical factors that influence the lives of people and wildlife can be investigated fully only by incorporating social science methods, ideally within an interdisciplinary framework. Cultural hierarchies of knowledge and the hegemony of the natural sciences create a barrier to interdisciplinary understandings. Here, we review three different projects that confront this difficulty, integrating biological and ethnographic methods to study conservation problems. The first project involved wildlife foraging on crops around a newly established national park in Gabon. Biological methods revealed the extent of crop loss, the species responsible, and an effect of field isolation, while ethnography revealed institutional and social vulnerability to foraging wildlife. The second project concerned great ape tourism in the Central African Republic. Biological methods revealed that gorilla tourism poses risks to gorillas, while ethnography revealed why people seek close proximity to gorillas. The third project focused on humans and other primates living alongside one another in Morocco. Incorporating shepherds in the coproduction of ecological knowledge about primates built trust and altered attitudes to the primates. These three case studies demonstrate how the integration of biological and social methods can help us to understand the sustainability of human-wildlife interactions, and thus promote coexistence. In each case, an integrated biosocial approach incorporating ethnographic data produced results that would not otherwise have come to light. Research that transcends conventional academic boundaries requires the openness and flexibility to move beyond one's comfort zone to understand and acknowledge the legitimacy of "other" kinds of knowledge. It is

Comparison of human and electronic observation for the measurement of compliance with hand hygiene.

Science.gov (United States)

Filho, Miguel Almeida O; Marra, Alexandre R; Magnus, Thyago Pereira; Rodrigues, Rodrigo Dias; Prado, Marcelo; de Souza Santini, Tales Roberto; da Silva Victor, Elivane; Ishibe, Eder Issao; Pavão Dos Santos, Oscar Fernando; Edmond, Michael B

2014-11-01

Monitoring of hand hygiene is an important part of the improvement of hospital quality indicators. This study was prospectively performed over a 14-week (electronic observer) period from December 3, 2013-March 9, 2014, to evaluate hand hygiene compliance in an adult step-down unit. We compared electronic handwash counters with the application of radiofrequency identification (RFID - ZigBee; i-Healthsys, São Carlos, Brazil) (electronic observer), which counts each activation of the alcohol gel dispenser to direct observation (human observer) using the iScrub application. For the overall time period of simultaneous electronic and human observation, we found that the electronic observer identified 414 hand hygiene episodes, whereas the human observers identified 448 episodes. Therefore, we found 92% (95% confidence interval [CI], 90%-95%) overall concordance (414/448), with an intraclass correlation coefficient of .87 (95% CI, 0.77-0.92). Our RFID (ZigBee) system showed good accuracy (92%) and is a useful method to monitor hand hygiene compliance. Copyright © 2014 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

The impact of advances in human molecular biology on radiation genetic risk estimation in man

International Nuclear Information System (INIS)

Sankaranarayanan, K.

1996-01-01

This paper provides an overview of the conceptual framework, the data base, methods and assumptions used thus far to assess the genetic risks of exposure of human populations to ionising radiation. These are then re-examined in the contemporary context of the rapidly expanding knowledge of the molecular biology of human mendelian diseases. This re-examination reveals that (i) many of the assumptions used thus far in radiation genetic risk estimation may not be fully valid and (ii) the current genetic risk estimates are probably conservative, but provide an adequate margin of safety for radiological protection. The view is expressed that further advances in the field of genetic risk estimation will be largely driven by advances in the molecular biology of human genetic diseases. (author). 37 refs., 5 tabs

Electron Resonance Decay into a Biological Function: Decrease in Viability of E. coli Transformed by Plasmid DNA Irradiated with 0.5-18 eV Electrons.

Science.gov (United States)

Kouass Sahbani, S; Cloutier, P; Bass, A D; Hunting, D J; Sanche, L

2015-10-01

Transient negative ions (TNIs) are ubiquitous in electron-molecule scattering at low electron impact energies (0-20 eV) and are particularly effective in damaging large biomolecules. Because ionizing radiation generates mostly 0-20 eV electrons, TNIs are expected to play important roles in cell mutagenesis and death during radiotherapeutic cancer treatment, although this hypothesis has never been directly verified. Here, we measure the efficiency of transforming E. coli bacteria by inserting into the cells, pGEM-3ZfL(-) plasmid DNA that confers resistance to the antibiotic ampicillin. Before transformation, plasmids are irradiated with electrons of specific energies between 0.5 and 18 eV. The loss of transformation efficiency plotted as a function of irradiation energy reveals TNIs at 5.5 and 9.5 eV, corresponding to similar states observed in the yields of DNA double strand breaks. We show that TNIs are detectable in the electron-energy dependence of a biological process and can decrease cell viability.

Hydrogen, metals, bifurcating electrons, and proton gradients: the early evolution of biological energy conservation.

Science.gov (United States)

Martin, William F

2012-03-09

Life is a persistent, self-specified set of far from equilibrium chemical reactions. In modern microbes, core carbon and energy metabolism are what keep cells alive. In very early chemical evolution, the forerunners of carbon and energy metabolism were the processes of generating reduced carbon compounds from CO(2) and the mechanisms of harnessing energy as compounds capable of doing some chemical work. The process of serpentinization at alkaline hydrothermal vents holds promise as a model for the origin of early reducing power, because Fe(2+) in the Earth's crust reduces water to H(2) and inorganic carbon to methane. The overall geochemical process of serpentinization is similar to the biochemical process of methanogenesis, and methanogenesis is similar to acetogenesis in that both physiologies allow energy conservation from the reduction of CO(2) with electrons from H(2). Electron bifurcation is a newly recognized cytosolic process that anaerobes use generate low potential electrons, it plays an important role in some forms of methanogenesis and, via speculation, possibly in acetogenesis. Electron bifurcation likely figures into the early evolution of biological energy conservation. Copyright © 2011. Published by Elsevier B.V.

Assessment of a Standardized ROS Production Profile in Humans by Electron Paramagnetic Resonance

Directory of Open Access Journals (Sweden)

Simona Mrakic-Sposta

2012-01-01

Full Text Available Despite the growing interest in the role of reactive oxygen species (ROS in health and disease, reliable quantitative noninvasive methods for the assessment of oxidative stress in humans are still lacking. EPR technique, coupled to a specific spin probe (CMH: 1-hydroxy-3-methoxycarbonyl-2,2,5,5-tetramethylpyrrolidine is here presented as the method of choice to gain a direct measurement of ROS in biological fluids and tissues. The study aimed at demonstrating that, differently from currently available “a posteriori” assays of ROS-induced damage by means of biomolecules (e.g., proteins and lipids spin-trapping EPR provides direct evidence of the “instantaneous” presence of radical species in the sample and, as signal areas are proportional to the number of excited electron spins, lead to absolute concentration levels. Using a recently developed bench top continuous wave system (e-scan EPR scanner, Bruker dealing with very low ROS concentration levels in small (50 μL samples, we successfully monitored rapid ROS production changes in peripheral blood of athletes after controlled exercise and sedentary subjects after antioxidant supplementation. The correlation between EPR results and data obtained by various enzymatic assays (e.g., protein carbonyls and thiobarbituric acid reactive substances was determined too. Synthetically, our method allows reliable, quick, noninvasive quantitative determination of ROS in human peripheral blood.

Quantifying electron transfer reactions in biological systems

DEFF Research Database (Denmark)

Sjulstok, Emil Sjulstok; Olsen, Jógvan Magnus Haugaard; Solov'yov, Ilia A

2015-01-01

which for example occur in photosynthesis, cellular respiration, DNA repair, and possibly magnetic field sensing. Quantum biology uses computation to model biological interactions in light of quantum mechanical effects and has primarily developed over the past decade as a result of convergence between...

Biological stimulation of the Human skin applying health promoting light and plasma sources

Energy Technology Data Exchange (ETDEWEB)

Awakowicz, P.; Bibinov, N. [Center for Plasma Science and Technology, Ruhr-University, Bochum (Germany); Born, M.; Niemann, U. [Philips Research, Aachen (Germany); Busse, B. [Zell-Kontakt GmbH, Noerten-Hardenberg (Germany); Gesche, R.; Kuehn, S.; Porteanu, H.E. [Ferdinand-Braun-Institut fuer Hoechstfrequenztechnik, Berlin (Germany); Helmke, A. [University of Applied Sciences and Arts, Goettingen (Germany); Kaemling, A.; Wandke, D. [CINOGY GmbH, Duderstadt (Germany); Kolb-Bachofen, V.; Liebmann, J. [Institute for Immunobiology, Heinrich-Heine University, Duesseldorf (Germany); Kovacs, R.; Mertens, N.; Scherer, J. [Aurion Anlagentechnik GmbH, Seligenstadt (Germany); Oplaender, C.; Suschek, C. [Clinic for Plastic Surgery, University Clinic, Aachen (Germany); Vioel, W. [Laser-Laboratorium, Goettingen (Germany); University of Applied Sciences and Arts, Goettingen (Germany)

2009-10-15

In the frame of BMBF project ''BioLiP'', new physical treatment techniques aiming at medical treatment of the human skin have been developed. The acronym BioLiP stands for ''Desinfektion, Entkeimung und biologische Stimulation der Haut durch gesundheitsfoerdernde Licht- und Plasmaquellen'' (Disinfection, germ reduction and biological stimulation of the human skin by health promoting light and plasma sources). A source applying a low-temperature dielectric barrier discharge plasma (DBD) has been investigated on its effectiveness for skin disinfection and stimulation of biological material. Alternatively an atmospheric plasma source consisting of a microwave resonator combined with a solid state power oscillator has been examined. This concept which allows for a compact and efficient design avoiding external microwave power supply and matching units has been optimized with respect to nitrogen monoxide (NO) production in high yields. In both cases various application possibilities in the medical and biological domain are opened up. Light sources in the visible spectral range have been investigated with respect to the proliferation of human cell types. Intensive highly selective blue light sources based on LED technology can slow down proliferation rates without inducing toxic effects which offers new opportunities for treatments of so-called hyperproliferative skin conditions (e.g. with psoriasis or in wound healing) using UV-free light. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Designing mental health interventions informed by child development and human biology theory: a social ecology intervention for child soldiers in Nepal.

Science.gov (United States)

Kohrt, Brandon A; Jordans, Mark J D; Koirala, Suraj; Worthman, Carol M

2015-01-01

The anthropological study of human biology, health, and child development provides a model with potential to address the gap in population-wide mental health interventions. Four key concepts from human biology can inform public mental health interventions: life history theory and tradeoffs, redundancy and plurality of pathways, cascades and multiplier effects in biological systems, and proximate feedback systems. A public mental health intervention for former child soldiers in Nepal is used to illustrate the role of these concepts in intervention design and evaluation. Future directions and recommendations for applying human biology theory in pursuit of public mental health interventions are discussed. © 2014 Wiley Periodicals, Inc.

Marine Biology and Human Affairs

Science.gov (United States)

Russell, F. S.

1976-01-01

Marine biology has become an important area for study throughout the world. The author of this article discusses some of the important discoveries and fields of research in marine biology that are useful for mankind. Topics include food from the sea, fish farming, pesticides, pollution, and conservation. (MA)

Modeling human risk: Cell & molecular biology in context

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-06-01

It is anticipated that early in the next century manned missions into outer space will occur, with a mission to Mars scheduled between 2015 and 2020. However, before such missions can be undertaken, a realistic estimation of the potential risks to the flight crews is required. One of the uncertainties remaining in this risk estimation is that posed by the effects of exposure to the radiation environment of outer space. Although the composition of this environment is fairly well understood, the biological effects arising from exposure to it are not. The reasons for this are three-fold: (1) A small but highly significant component of the radiation spectrum in outer space consists of highly charged, high energy (HZE) particles which are not routinely experienced on earth, and for which there are insufficient data on biological effects; (2) Most studies on the biological effects of radiation to date have been high-dose, high dose-rate, whereas in space, with the exception of solar particle events, radiation exposures will be low-dose, low dose-rate; (3) Although it has been established that the virtual absence of gravity in space has a profound effect on human physiology, it is not clear whether these effects will act synergistically with those of radiation exposure. A select panel will evaluate the utilizing experiments and models to accurately predict the risks associated with exposure to HZE particles. Topics of research include cellular and tissue response, health effects associated with radiation damage, model animal systems, and critical markers of Radiation response.

Practical aspects of Boersch phase contrast electron microscopy of biological specimens

Energy Technology Data Exchange (ETDEWEB)

Walter, Andreas [Max-Planck-Institute of Biophysics, Department of Structural Biology, Max-von-Laue-Str. 3, D-60439 Frankfurt (Germany); Muzik, Heiko; Vieker, Henning; Turchanin, Andrey; Beyer, Andre; Goelzhaeuser, Armin [University of Bielefeld, Physics of Supramolecular Systems and Surfaces, Universitaetsstr. 25, D-33615 Bielefeld (Germany); Lacher, Manfred; Steltenkamp, Siegfried; Schmitz, Sam; Holik, Peter [Caesar Research Center, Ludwig-Erhard-Allee 2, D-53175 Bonn (Germany); Kuehlbrandt, Werner [Max-Planck-Institute of Biophysics, Department of Structural Biology, Max-von-Laue-Str. 3, D-60439 Frankfurt (Germany); Rhinow, Daniel, E-mail: daniel.rhinow@biophys.mpg.de [Max-Planck-Institute of Biophysics, Department of Structural Biology, Max-von-Laue-Str. 3, D-60439 Frankfurt (Germany)

2012-05-15

Implementation of physical phase plates into transmission electron microscopes to achieve in-focus contrast for ice-embedded biological specimens poses several technological challenges. During the last decade several phase plates designs have been introduced and tested for electron cryo-microscopy (cryoEM), including thin film (Zernike) phase plates and electrostatic devices. Boersch phase plates (BPPs) are electrostatic einzel lenses shifting the phase of the unscattered beam by an arbitrary angle. Adjusting the phase shift to 90 Degree-Sign achieves the maximum contrast transfer for phase objects such as biomolecules. Recently, we reported the implementation of a BPP into a dedicated phase contrast aberration-corrected electron microscope (PACEM) and demonstrated its use to generate in-focus contrast of frozen-hydrated specimens. However, a number of obstacles need to be overcome before BPPs can be used routinely, mostly related to the phase plate devices themselves. CryoEM with a physical phase plate is affected by electrostatic charging, obliteration of low spatial frequencies, and mechanical drift. Furthermore, BPPs introduce single sideband contrast (SSB), due to the obstruction of Friedel mates in the diffraction pattern. In this study we address the technical obstacles in detail and show how they may be overcome. We use X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES) to identify contaminants responsible for electrostatic charging, which occurs with most phase plates. We demonstrate that obstruction of low-resolution features is significantly reduced by lowering the acceleration voltage of the microscope. Finally, we present computational approaches to correct BPP images for SSB contrast and to compensate for mechanical drift of the BPP. -- Highlights: Black-Right-Pointing-Pointer Various obstacles need to be overcome before Boersch phase plates can be used routinely. Black-Right-Pointing-Pointer Technical problems include

Practical aspects of Boersch phase contrast electron microscopy of biological specimens

International Nuclear Information System (INIS)

Walter, Andreas; Muzik, Heiko; Vieker, Henning; Turchanin, Andrey; Beyer, André; Gölzhäuser, Armin; Lacher, Manfred; Steltenkamp, Siegfried; Schmitz, Sam; Holik, Peter; Kühlbrandt, Werner; Rhinow, Daniel

2012-01-01

Implementation of physical phase plates into transmission electron microscopes to achieve in-focus contrast for ice-embedded biological specimens poses several technological challenges. During the last decade several phase plates designs have been introduced and tested for electron cryo-microscopy (cryoEM), including thin film (Zernike) phase plates and electrostatic devices. Boersch phase plates (BPPs) are electrostatic einzel lenses shifting the phase of the unscattered beam by an arbitrary angle. Adjusting the phase shift to 90° achieves the maximum contrast transfer for phase objects such as biomolecules. Recently, we reported the implementation of a BPP into a dedicated phase contrast aberration-corrected electron microscope (PACEM) and demonstrated its use to generate in-focus contrast of frozen–hydrated specimens. However, a number of obstacles need to be overcome before BPPs can be used routinely, mostly related to the phase plate devices themselves. CryoEM with a physical phase plate is affected by electrostatic charging, obliteration of low spatial frequencies, and mechanical drift. Furthermore, BPPs introduce single sideband contrast (SSB), due to the obstruction of Friedel mates in the diffraction pattern. In this study we address the technical obstacles in detail and show how they may be overcome. We use X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES) to identify contaminants responsible for electrostatic charging, which occurs with most phase plates. We demonstrate that obstruction of low-resolution features is significantly reduced by lowering the acceleration voltage of the microscope. Finally, we present computational approaches to correct BPP images for SSB contrast and to compensate for mechanical drift of the BPP. -- Highlights: ► Various obstacles need to be overcome before Boersch phase plates can be used routinely. ► Technical problems include electrostatic charging, mechanical drift, and image artefacts. �

The sinusoidal lining cells in "normal" human liver. A scanning electron microscopic investigation

DEFF Research Database (Denmark)

Horn, T; Henriksen, Jens Henrik Sahl; Christoffersen, P

1986-01-01

The scanning electron microscopic was used to study the fenestrations of human liver sinusoids. Thirteen biopsies, where light microscopy and transmission electron microscopy revealed normal sinusoidal architecture, were investigated. The number of fenestrae was calculated in acinar zone 3...

Electronic Document Management: A Human Resource Management Case Study

Directory of Open Access Journals (Sweden)

Thomas Groenewald

2004-11-01

Full Text Available This case study serve as exemplar regarding what can go wrong with the implementation of an electronic document management system. Knowledge agility and knowledge as capital, is outlined against the backdrop of the information society and knowledge economy. The importance of electronic document management and control is sketched thereafter. The literature review is concluded with the impact of human resource management on knowledge agility, which includes references to the learning organisation and complexity theory. The intervention methodology, comprising three phases, follows next. The results of the three phases are presented thereafter. Partial success has been achieved with improving the human efficacy of electronic document management, however the client opted to discontinue the system in use. Opsomming Die gevalle studie dien as voorbeeld van wat kan verkeerd loop met die implementering van ’n elektroniese dokumentbestuur sisteem. Teen die agtergrond van die inligtingsgemeenskap en kennishuishouding word kennissoepelheid en kennis as kapitaal bespreek. Die literatuurstudie word afgesluit met die inpak van menslikehulpbronbestuur op kennissoepelheid, wat ook die verwysings na die leerorganisasie en kompleksietydsteorie insluit. Die metodologie van die intervensie, wat uit drie fases bestaan, volg daarna. Die resultate van die drie fases word vervolgens aangebied. Slegs gedeelte welslae is behaal met die verbetering van die menslike doeltreffendheid ten opsigte van elektroniese dokumentbestuur. Die klient besluit egter om nie voort te gaan om die huidige sisteem te gebruik nie.

Human Embryonic Kidney 293 Cells: A Vehicle for Biopharmaceutical Manufacturing, Structural Biology, and Electrophysiology.

Science.gov (United States)

Hu, Jianwen; Han, Jizhong; Li, Haoran; Zhang, Xian; Liu, Lan Lan; Chen, Fei; Zeng, Bin

2018-01-01

Mammalian cells, e.g., CHO, BHK, HEK293, HT-1080, and NS0 cells, represent important manufacturing platforms in bioengineering. They are widely used for the production of recombinant therapeutic proteins, vaccines, anticancer agents, and other clinically relevant drugs. HEK293 (human embryonic kidney 293) cells and their derived cell lines provide an attractive heterologous system for the development of recombinant proteins or adenovirus productions, not least due to their human-like posttranslational modification of protein molecules to provide the desired biological activity. Secondly, they also exhibit high transfection efficiency yielding high-quality recombinant proteins. They are easy to maintain and express with high fidelity membrane proteins, such as ion channels and transporters, and thus are attractive for structural biology and electrophysiology studies. In this article, we review the literature on HEK293 cells regarding their origins but also stress their advancements into the different cell lines engineered and discuss some significant aspects which make them versatile systems for biopharmaceutical manufacturing, drug screening, structural biology research, and electrophysiology applications. © 2018 S. Karger AG, Basel.

Wood-Derived Materials for Green Electronics, Biological Devices, and Energy Applications.

Science.gov (United States)

Zhu, Hongli; Luo, Wei; Ciesielski, Peter N; Fang, Zhiqiang; Zhu, J Y; Henriksson, Gunnar; Himmel, Michael E; Hu, Liangbing

2016-08-24

With the arising of global climate change and resource shortage, in recent years, increased attention has been paid to environmentally friendly materials. Trees are sustainable and renewable materials, which give us shelter and oxygen and remove carbon dioxide from the atmosphere. Trees are a primary resource that human society depends upon every day, for example, homes, heating, furniture, and aircraft. Wood from trees gives us paper, cardboard, and medical supplies, thus impacting our homes, school, work, and play. All of the above-mentioned applications have been well developed over the past thousands of years. However, trees and wood have much more to offer us as advanced materials, impacting emerging high-tech fields, such as bioengineering, flexible electronics, and clean energy. Wood naturally has a hierarchical structure, composed of well-oriented microfibers and tracheids for water, ion, and oxygen transportation during metabolism. At higher magnification, the walls of fiber cells have an interesting morphology-a distinctly mesoporous structure. Moreover, the walls of fiber cells are composed of thousands of fibers (or macrofibrils) oriented in a similar angle. Nanofibrils and nanocrystals can be further liberated from macrofibrils by mechanical, chemical, and enzymatic methods. The obtained nanocellulose has unique optical, mechanical, and barrier properties and is an excellent candidate for chemical modification and reconfiguration. Wood is naturally a composite material, comprised of cellulose, hemicellulose, and lignin. Wood is sustainable, earth abundant, strong, biodegradable, biocompatible, and chemically accessible for modification; more importantly, multiscale natural fibers from wood have unique optical properties applicable to different kinds of optoelectronics and photonic devices. Today, the materials derived from wood are ready to be explored for applications in new technology areas, such as electronics, biomedical devices, and energy. The

Wood-Derived Materials for Green Electronics, Biological Devices, and Energy Applications

Energy Technology Data Exchange (ETDEWEB)

Zhu, Hongli; Luo, Wei; Ciesielski, Peter N.; Fang, Zhiqiang; Zhu, J. Y.; Henriksson, Gunnar; Himmel, Michael E.; Hu, Liangbing

2016-08-24

With the arising of global climate change and resource shortage, in recent years, increased attention has been paid to environmentally friendly materials. Trees are sustainable and renewable materials, which give us shelter and oxygen and remove carbon dioxide from the atmosphere. Trees are a primary resource that human society depends upon every day, for example, homes, heating, furniture, and aircraft. Wood from trees gives us paper, cardboard, and medical supplies, thus impacting our homes, school, work, and play. All of the above-mentioned applications have been well developed over the past thousands of years. However, trees and wood have much more to offer us as advanced materials, impacting emerging high-tech fields, such as bioengineering, flexible electronics, and clean energy. Wood naturally has a hierarchical structure, composed of well-oriented microfibers and tracheids for water, ion, and oxygen transportation during metabolism. At higher magnification, the walls of fiber cells have an interesting morphology--a distinctly mesoporous structure. Moreover, the walls of fiber cells are composed of thousands of fibers (or macrofibrils) oriented in a similar angle. Nanofibrils and nanocrystals can be further liberated from macrofibrils by mechanical, chemical, and enzymatic methods. The obtained nanocellulose has unique optical, mechanical, and barrier properties and is an excellent candidate for chemical modification and reconfiguration. Wood is naturally a composite material, comprised of cellulose, hemicellulose, and lignin. Wood is sustainable, earth abundant, strong, biodegradable, biocompatible, and chemically accessible for modification; more importantly, multiscale natural fibers from wood have unique optical properties applicable to different kinds of optoelectronics and photonic devices. Today, the materials derived from wood are ready to be explored for applications in new technology areas, such as electronics, biomedical devices, and energy. The

On making nursing undergraduate human reproductive physiology content meaningful and relevant: discussion of human pleasure in its biological context.

Science.gov (United States)

McClusky, Leon Mendel

2012-01-01

The traditional presentation of the Reproductive Physiology component in an Anatomy and Physiology course to nursing undergraduates focuses on the broad aspects of hormonal regulation of reproduction and gonadal anatomy, with the role of the higher centres of the brain omitted. An introductory discussion is proposed which could precede the lectures on the reproductive organs. The discussion gives an overview of the biological significance of human pleasure, the involvement of the neurotransmitter dopamine, and the role of pleasure in the survival of the individual and even species. Pleasure stimuli (positive and negative) and the biological significance of naturally-induced pleasurable experiences are briefly discussed in the context of reproduction and the preservation of genetic material with an aim to foster relevancy between subject material and human behaviour in any type of society. The tenderness of this aspect of the human existence is well-understood because of its invariable association with soul-revealing human expressions such as love, infatuation, sexual flirtations, all of which are underpinned by arousal, desire and/or pleasure. Assuming that increased knowledge correlates with increased confidence, the proposed approach may provide the nurse with an adequate knowledge base to overcome well-known barriers in communicating with their patients about matters of sexual health and intimacy. Copyright © 2011 Elsevier Ltd. All rights reserved.

Biological effects of plasma rich in growth factors (PRGF) on human endometrial fibroblasts.

Science.gov (United States)

Anitua, Eduardo; de la Fuente, María; Ferrando, Marcos; Quintana, Fernando; Larreategui, Zaloa; Matorras, Roberto; Orive, Gorka

2016-11-01

To evaluate the biological outcomes of plasma rich in growth factors (PRGF) on human endometrial fibroblasts in culture. PRGF was obtained from three healthy donors and human endometrial fibroblasts (HEF) were isolated from endometrial specimens from five healthy women. The effects of PRGF on cell proliferation and migration, secretion of vascular endothelial growth factor (VEGF), procollagen type I and hyaluronic acid (HA) and contractility of isolated and cultured human endometrial fibroblasts (HEF) were analyzed. Statistical analysis was performed in order to compare the effects of PRGF with respect to control situation (T-test or Mann-Whitney U-test). We report a significantly elevated human endometrial fibroblast proliferation and migration after treatment with PRGF. In addition, stimulation of HEF with PRGF induced an increased expression of the angiogenic factor VEGF and favored the endometrial matrix remodeling by the secretion of procollagen type I and HA and endometrial regeneration by elevating the contractility of HEF. These results were obtained for all PRGF donors and each endometrial cell line. The myriad of growth factors contained in PRGF promoted HEF proliferation, migration and synthesis of paracrine molecules apart from increasing their contractility potential. These preliminary results suggest that PRGF improves the biological activity of HEF in vitro, enhancing the regulation of several cellular processes implied in endometrial regeneration. This innovative treatment deserves further investigation for its potential in "in vivo" endometrial development and especially in human embryo implantation. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Exploring Visuomotor Priming Following Biological and Non-Biological Stimuli

Science.gov (United States)

Gowen, E.; Bradshaw, C.; Galpin, A.; Lawrence, A.; Poliakoff, E.

2010-01-01

Observation of human actions influences the observer's own motor system, termed visuomotor priming, and is believed to be caused by automatic activation of mirror neurons. Evidence suggests that priming effects are larger for biological (human) as opposed to non-biological (object) stimuli and enhanced when viewing stimuli in mirror compared to…

Human Possibilities: The Interaction of Biology and Culture

Directory of Open Access Journals (Sweden)

Riane Eisler

2015-06-01

Full Text Available This article briefly describes the two main strands of a new unified theory about human nature and human possibilities: cultural transformation theory and bio-culturalism. Bio-culturalism combines findings from neuroscience about how our brains develop in interaction with our environments with findings from the study of relational dynamics, a new method of social analysis focusing on what kinds of relations—from intimate to international—a particular culture or subculture supports. Bio-culturalism recognizes that our species has a vast spectrum of genetic capacities, ranging from consciousness, caring, empathy, cooperation, and creativity to insensitivity, cruelty, exploitation, and destructiveness, and proposes that which of these capacities are expressed or inhibited largely hinges on the nature of our cultural environments. Cultural transformation theory looks at the whole span of human cultural evolution from the perspective of the tension between the contrasting configurations of the partnership system and the domination system as two underlying possibilities for structuring beliefs, institutions, and relationships. The article describes the core components of partnership- and domination-oriented societies, provides examples of each, and proposes that our future hinges on accelerating the cultural transformation from domination to partnership in our time of nuclear and biological weapons and the ever more efficient despoliation of nature, when high technology guided by an ethos of domination and conquest could take us to an evolutionary dead end.

Protein electron transfer: is biology (thermo)dynamic?

International Nuclear Information System (INIS)

Matyushov, Dmitry V

2015-01-01

Simple physical mechanisms are behind the flow of energy in all forms of life. Energy comes to living systems through electrons occupying high-energy states, either from food (respiratory chains) or from light (photosynthesis). This energy is transformed into the cross-membrane proton-motive force that eventually drives all biochemistry of the cell. Life’s ability to transfer electrons over large distances with nearly zero loss of free energy is puzzling and has not been accomplished in synthetic systems. The focus of this review is on how this energetic efficiency is realized. General physical mechanisms and interactions that allow proteins to fold into compact water-soluble structures are also responsible for a rugged landscape of energy states and a broad distribution of relaxation times. Specific to a protein as a fluctuating thermal bath is the protein-water interface, which is heterogeneous both dynamically and structurally. The spectrum of interfacial fluctuations is a consequence of protein’s elastic flexibility combined with a high density of surface charges polarizing water dipoles into surface nanodomains. Electrostatics is critical to the protein function and the relevant questions are: (i) What is the spectrum of interfacial electrostatic fluctuations? (ii) Does the interfacial biological water produce electrostatic signatures specific to proteins? (iii) How is protein-mediated chemistry affected by electrostatics? These questions connect the fluctuation spectrum to the dynamical control of chemical reactivity, i.e. the dependence of the activation free energy of the reaction on the dynamics of the bath. Ergodicity is often broken in protein-driven reactions and thermodynamic free energies become irrelevant. Continuous ergodicity breaking in a dense spectrum of relaxation times requires using dynamically restricted ensembles to calculate statistical averages. When applied to the calculation of the rates, this formalism leads to the nonergodic

Electron reactions in model liquids and biological systems

International Nuclear Information System (INIS)

Bakale, G.; Gregg, E.C.

1982-01-01

Progress is reported in the following studies: (1) Field-dependent electron attachment; (2) Dependence of electron attachment rate on electron-acceptor dipole moment; (3) Electron attachment in i-octane/TMS mixtures; (4) Electron attachment/detachment equilibria; (5) Electron attachment to reversed micelles; (6) Electron attachment to chemical carcinogens; (7) Radiation-induced bacterial mutagenesis; and (8) Bacterial mutagenicity of nitrobenzene derivatives. 14 references

In-focus electron microscopy of frozen-hydrated biological samples with a Boersch phase plate

Energy Technology Data Exchange (ETDEWEB)

Barton, B.; Rhinow, D.; Walter, A.; Schroeder, R. [Max Planck Institute of Biophysics, Max-von-Laue Str. 3, 60438 Frankfurt am Main (Germany); Benner, G.; Majorovits, E.; Matijevic, M.; Niebel, H. [Carl Zeiss NTS GmbH, D-73447 Oberkochen (Germany); Mueller, H.; Haider, M. [CEOS GmbH, Englerstr. 26, 69126 Heidleberg (Germany); Lacher, M.; Schmitz, S.; Holik, P. [Caesar Research Center, Ludwig-Erhard-Allee 2, D-53175 Bonn (Germany); Kuehlbrandt, W., E-mail: werner.kuehlbrandt@mpibp-frankfurt.mpg.de [Max Planck Institute of Biophysics, Max-von-Laue Str. 3, 60438 Frankfurt am Main (Germany)

2011-12-15

We report the implementation of an electrostatic Einzel lens (Boersch) phase plate in a prototype transmission electron microscope dedicated to aberration-corrected cryo-EM. The combination of phase plate, C{sub s} corrector and Diffraction Magnification Unit (DMU) as a new electron-optical element ensures minimal information loss due to obstruction by the phase plate and enables in-focus phase contrast imaging of large macromolecular assemblies. As no defocussing is necessary and the spherical aberration is corrected, maximal, non-oscillating phase contrast transfer can be achieved up to the information limit of the instrument. A microchip produced by a scalable micro-fabrication process has 10 phase plates, which are positioned in a conjugate, magnified diffraction plane generated by the DMU. Phase plates remained fully functional for weeks or months. The large distance between phase plate and the cryo sample permits the use of an effective anti-contaminator, resulting in ice contamination rates of <0.6 nm/h at the specimen. Maximal in-focus phase contrast was obtained by applying voltages between 80 and 700 mV to the phase plate electrode. The phase plate allows for in-focus imaging of biological objects with a signal-to-noise of 5-10 at a resolution of 2-3 nm, as demonstrated for frozen-hydrated virus particles and purple membrane at liquid-nitrogen temperature. -- Highlights: Black-Right-Pointing-Pointer We implement an electrostatic Boersch phase plate into a dedicated prototypical TEM. Black-Right-Pointing-Pointer Phase contrast aberration-corrected electron microscope (PACEM) includes a diffraction magnification unit (DMU). Black-Right-Pointing-Pointer DMU minimizes obstruction of low spatial frequencies by the phase plate. Black-Right-Pointing-Pointer In-focus phase contrast generation is demonstrated for frozen-hydrated biological specimens.

Biological shielding design and qualification of concreting process for construction of electron beam irradiation facility

International Nuclear Information System (INIS)

Petwal, V.C.; Kumar, P.; Suresh, N.; Parchani, G.; Dwivedi, J.; Thakurta, A.C.

2011-01-01

A technology demonstration facility for irradiation of food and agricultural products is being set-up by RRCAT at Indore. The facility design is based on linear electron accelerator with maximum beam power of 10 kW and can be operated either in electron mode at 10 MeV or photon modes at 5/7.5 MeV. Biological shielding has been designed in accordance with NCRP 51 to achieve dose rate at all accessible points outside the irradiation vault less than the permissible limit of 0.1 mR/hr. In addition to radiation attenuation property, concrete must have satisfactory mechanical properties to meet the structural requirements. There are number of site specific variables which affect the structural, thermal and radiological properties of concrete, leading to considerable difference in actual values and design values. Hence it is essential to establish a suitable site and environmental specific process to cast the concrete and qualify the process by experimental measurement. For process qualification we have cast concrete test blocks of different thicknesses up to 3.25 m and evaluated the radiological and mechanical properties by radiometry, ultrasonic and mechanical tests. In this paper we describe the biological shielding design of the facility and analyse the results of tests carried out for qualification of the process. (author)

The analysis for energy distribution and biological effects of the clusters from electrons in the tissue equivalent material

International Nuclear Information System (INIS)

Zhang Wenzhong; Guo Yong; Luo Yisheng; Wang Yong

2004-01-01

Objective: To study energy distribution of the clusters from electrons in the tissue equivalent material, and discuss the important aspects of these clusters on inducing biological effects. Methods: Based on the physical mechanism for electrons interacting with tissue equivalent material, the Monte Carlo (MC) method was used. The electron tracks were lively simulated on an event-by-event (ionization, excitation, elastic scattering, Auger electron emission) basis in the material. The relevant conclusions were drawn from the statistic analysis of these events. Results: The electrons will deposit their energy in the form (30%) of cluster in passing through tissue equivalent material, and most clusters (80%) have the energy amount of more than 50 eV. The cluster density depends on its diameter and energy of electrons, and the deposited energy in the cluster depends on the type and energy of radiation. Conclusion: The deposited energy in cluster is the most important factor in inducing all sort of lesions on DNA molecules in tissue cells

How do precision medicine and system biology response to human body's complex adaptability?

Science.gov (United States)

Yuan, Bing

2016-12-01

In the field of life sciences, although system biology and "precision medicine" introduce some complex scientifific methods and techniques, it is still based on the "analysis-reconstruction" of reductionist theory as a whole. Adaptability of complex system increase system behaviour uncertainty as well as the difficulties of precise identifification and control. It also put systems biology research into trouble. To grasp the behaviour and characteristics of organism fundamentally, systems biology has to abandon the "analysis-reconstruction" concept. In accordance with the guidelines of complexity science, systems biology should build organism model from holistic level, just like the Chinese medicine did in dealing with human body and disease. When we study the living body from the holistic level, we will fifind the adaptability of complex system is not the obstacle that increases the diffificulty of problem solving. It is the "exceptional", "right-hand man" that helping us to deal with the complexity of life more effectively.

New methodologies of biological dosimetry applied to human protection

International Nuclear Information System (INIS)

Catena, C.; Parasacchi, P.; Conti, D.; Righi, E.

1995-04-01

Biological dosimetry is a diagnostic methodology for the measurement of the individual dose absorbed in the case of accidental overexposition to ionizing radiation. It is demonstrated how in vitro radiobiological and chemobiological studies using cytogenetic methods (count of chromosomal aberrations and micronuclei) on human lymphocytes from healthy subjects and individuals undergoing radiotherapy or chemotherapy, as well as on lymphocytes of mammals other than man (comparative cytogenetics), can help to increase the basic radiobiological and chemobiological scientific information. Such information gives a valid contribution to understanding of the action of ionizing radiation or of pharmaceuticals on cells and, in return, can be of value to human radioprotection and chemoprotection. Cytogenetic studies can be summerized as follows: a) biodosimetry (estimate of dose received after accidental events); b) individual radiosensitivity (level of individual response); c) clinical radiobiology and chemobiology (individual response to radiopharmaceuticals, to radiotherapy and to chemopharmaceuticals); d) comparative radiobiology (cytogenetic studies on species other than man); e) animal model in the environmental surveillance

Screening vaccine formulations for biological activity using fresh human whole blood.

OpenAIRE

Brookes, RH; Hakimi, J; Ha, Y; Aboutorabian, S; Ausar, SF; Hasija, M; Smith, SG; Todryk, SM; Dockrell, HM; Rahman, N

2014-01-01

Understanding the relevant biological activity of any pharmaceutical formulation destined for human use is crucial. For vaccine-based formulations, activity must reflect the expected immune response, while for non-vaccine therapeutic agents, such as monoclonal antibodies, a lack of immune response to the formulation is desired. During early formulation development, various biochemical and biophysical characteristics can be monitored in a high-throughput screening (HTS) format. However, it rem...

Dendritic Cells in the Context of Human Tumors: Biology and Experimental Tools.

Science.gov (United States)

Volovitz, Ilan; Melzer, Susanne; Amar, Sarah; Bocsi, József; Bloch, Merav; Efroni, Sol; Ram, Zvi; Tárnok, Attila

2016-01-01

Dendritic cells (DC) are the most potent and versatile antigen-presenting cells (APC) in the immune system. DC have an exceptional ability to comprehend the immune context of a captured antigen based on molecular signals identified from its vicinity. The analyzed information is then conveyed to other immune effector cells. Such capability enables DC to play a pivotal role in mediating either an immunogenic response or immune tolerance towards an acquired antigen. This review summarizes current knowledge on DC in the context of human tumors. It covers the basics of human DC biology, elaborating on the different markers, morphology and function of the different subsets of human DC. Human blood-borne DC are comprised of at least three subsets consisting of one plasmacytoid DC (pDC) and two to three myeloid DC (mDC) subsets. Some tissues have unique DC. Each subset has a different phenotype and function and may induce pro-tumoral or anti-tumoral effects. The review also discusses two methods fundamental to the research of DC on the single-cell level: multicolor flow cytometry (FCM) and image-based cytometry (IC). These methods, along with new genomics and proteomics tools, can provide high-resolution information on specific DC subsets and on immune and tumor cells with which they interact. The different layers of collected biological data may then be integrated using Immune-Cytomics modeling approaches. Such novel integrated approaches may help unravel the complex network of cellular interactions that DC carry out within tumors, and may help harness this complex immunological information into the development of more effective treatments for cancer.

The preparation of albumin as a biological drug from human plasma by fiber filtration

Directory of Open Access Journals (Sweden)

Mousavi Hosseini K

2011-08-01

Full Text Available "nBackground: In recent years, consumption of whole-blood for the treatment of patients has decreased but use of biological plasma-derived medicines such as albumin, immunoglobulin and coagulation factors have increased instead. Paying attention to albumin molecular structure is important for its isolation from human plasma. Albumin is a single-chain protein consisting of about 585 amino acids and a molecular weight of 66500 Daltons. Albumin is a stable molecule and it is spherical in shape. There are different methods for human albumin preparation. Considering the large consumption of this biological drug in clinical settings, methods with fewer steps in production line are of big advantage in saving time and manufacturing more products."n "nMethods: In this project, we prepared human albumin using hollow fiber cartridges in order to omit the rework on fraction V+VI. Human albumin is usually produced by the application of cold ethanol method, where albumin is obtained from fraction V by doing a rework on fraction V+VI to separate fraction V."n "nResults: In the current work, human albumin was prepared from fraction V+VI by the help of hollow fiber cartridges. With a concentration of 20%, the obtained albumin had 96.5% of monomer and 3.5% of polymer and polymer aggregate."n "nConclusion: Comparing the obtained human albumin with a number of commercial human albumin samples by the use of SDS-page, the results were satisfactory regarding the 3.5 percent polymer and aggregate rate for the prepared albumin.

An Augmented γ-Spray System to Visualize Biological Effects for Human Body

Science.gov (United States)

Manabe, Seiya; Tenzou, Hideki; Kasuga, Takaaki; Iwakura, Yukiko; Johnston, Robert

2017-09-01

The purpose of this study was to develop a new educational system with an easy-to-use interface in order to support comprehension of the biological effects of radiation on the human body within a short period of time. A paint spray-gun was used as a gamma rays source mock-up for the system. The application screen shows the figure of a human body for radiation deposition using the γ-Sprayer, a virtual radiation source, as well as equivalent dosage and a panel for setting the irradiation conditions. While the learner stands in front of the PC monitor, the virtual radiation source is used to deposit radiation on the graphic of the human body that is displayed. Tissue damage is calculated using an interpolation method from the data calculated by the PHITS simulation code in advance while the learner is pulling the trigger with respect to the irradiation time, incident position, and distance from the screen. It was confirmed that the damage was well represented by the interpolation method. The augmented ?-Spray system was assessed by questionnaire. Pre-post questionnaire was taken for our 41 students in National Institute of Technology, Kagawa College. It was also confirmed that the system has a capability of teaching the basic radiation protection concept, quantitative feeling of the radiation dose, and the biological effects

Diversity of extracellular vesicles in human ejaculates revealed by cryo-electron microscopy

Directory of Open Access Journals (Sweden)

Johanna L. Höög

2015-11-01

Full Text Available Human ejaculates contain extracellular vesicles (EVs, that to a large extent are considered to originate from the prostate gland, and are often denominated “prostasomes.” These EVs are important for human fertility, for example by promoting sperm motility and by inducing immune tolerance of the female immune system to the spermatozoa. So far, the EVs present in human ejaculate have not been studied in their native state, inside the seminal fluid without prior purification and isolation procedures. Using cryo-electron microscopy and tomography, we performed a comprehensive inventory of human ejaculate EVs. The sample was neither centrifuged, fixed, filtered or sectioned, nor were heavy metals added. Approximately 1,500 extracellular structures were imaged and categorized. The extracellular environment of human ejaculate was found to be diverse, with 5 major subcategories of EVs and 6 subcategories of extracellular membrane compartments, including lamellar bodies. Furthermore, 3 morphological features, including electron density, double membrane bilayers and coated surface, are described in all subcategories. This study reveals that the extracellular environment in human ejaculate is multifaceted. Several novel morphological EV subcategories are identified and clues to their cellular origin may be found in their morphology. This inventory is therefore important for developing future experimental approaches, and to interpret previously published data to understand the role of EVs for human male fertility.

Urban Biomining Meets Printable Electronics: End-To-End at Destination Biological Recycling and Reprinting

Science.gov (United States)

Rothschild, Lynn J. (Principal Investigator); Koehne, Jessica; Gandhiraman, Ram; Navarrete, Jesica; Spangle, Dylan

2017-01-01

Space missions rely utterly on metallic components, from the spacecraft to electronics. Yet, metals add mass, and electronics have the additional problem of a limited lifespan. Thus, current mission architectures must compensate for replacement. In space, spent electronics are discarded; on earth, there is some recycling but current processes are toxic and environmentally hazardous. Imagine instead an end-to-end recycling of spent electronics at low mass, low cost, room temperature, and in a non-toxic manner. Here, we propose a solution that will not only enhance mission success by decreasing upmass and providing a fresh supply of electronics, but in addition has immediate applications to a serious environmental issue on the Earth. Spent electronics will be used as feedstock to make fresh electronic components, a process we will accomplish with so-called 'urban biomining' using synthetically enhanced microbes to bind metals with elemental specificity. To create new electronics, the microbes will be used as 'bioink' to print a new IC chip, using plasma jet electronics printing. The plasma jet electronics printing technology will have the potential to use martian atmospheric gas to print and to tailor the electronic and chemical properties of the materials. Our preliminary results have suggested that this process also serves as a purification step to enhance the proportion of metals in the 'bioink'. The presence of electric field and plasma can ensure printing in microgravity environment while also providing material morphology and electronic structure tunabiity and thus optimization. Here we propose to increase the TRL level of the concept by engineering microbes to dissolve the siliceous matrix in the IC, extract copper from a mixture of metals, and use the microbes as feedstock to print interconnects using mars gas simulant. To assess the ability of this concept to influence mission architecture, we will do an analysis of the infrastructure required to execute

Evaluation of the biological differences of canine and human factor VIII in gene delivery: Implications in human hemophilia treatment

Science.gov (United States)

The canine is the most important large animal model for testing novel hemophilia A(HA) treatment. It is often necessary to use canine factor VIII (cFIII) gene or protein for the evaluation of HA treatment in the canine model. However, the different biological properties between cFVIII and human FVII...

PreproVIP-derived peptides in the human female genital tract: expression and biological function

DEFF Research Database (Denmark)

Bredkjoer, H E; Palle, C; Ekblad, E

1997-01-01

The aim of the study was to elucidate the localization, distribution, colocalization and biological effect of preproVIP-derived peptides in the human female genital tract. Radioimmunoassays applying antisera against the five functional domains of the VIP precursor in combination with immunohistoc......The aim of the study was to elucidate the localization, distribution, colocalization and biological effect of preproVIP-derived peptides in the human female genital tract. Radioimmunoassays applying antisera against the five functional domains of the VIP precursor in combination...... with immunohistochemistry were used. The effect of preproVIP 22-79, preproVIP 111-122 and preproVIP 156-170 on genital smooth muscle activity in the Fallopian tube was investigated in vitro and compared to that of VIP. All the preproVIP-derived peptides were expressed throughout the genital tract in neuronal elements...

Energy Harvesting from the Animal/Human Body for Self-Powered Electronics.

Science.gov (United States)

Dagdeviren, Canan; Li, Zhou; Wang, Zhong Lin

2017-06-21

Living subjects (i.e., humans and animals) have abundant sources of energy in chemical, thermal, and mechanical forms. The use of these energies presents a viable way to overcome the battery capacity limitation that constrains the long-term operation of wearable/implantable devices. The intersection of novel materials and fabrication techniques offers boundless possibilities for the benefit of human health and well-being via various types of energy harvesters. This review summarizes the existing approaches that have been demonstrated to harvest energy from the bodies of living subjects for self-powered electronics. We present material choices, device layouts, and operation principles of these energy harvesters with a focus on in vivo applications. We discuss a broad range of energy harvesters placed in or on various body parts of human and animal models. We conclude with an outlook of future research in which the integration of various energy harvesters with advanced electronics can provide a new platform for the development of novel technologies for disease diagnostics, treatment, and prevention.

Dynamic Processes in Biology, Chemistry, and Materials Science: Opportunities for UltraFast Transmission Electron Microscopy - Workshop Summary Report

Energy Technology Data Exchange (ETDEWEB)

Kabius, Bernd C.; Browning, Nigel D.; Thevuthasan, Suntharampillai; Diehl, Barbara L.; Stach, Eric A.

2012-07-25

This report summarizes a 2011 workshop that addressed the potential role of rapid, time-resolved electron microscopy measurements in accelerating the solution of important scientific and technical problems. A series of U.S. Department of Energy (DOE) and National Academy of Science workshops have highlighted the critical role advanced research tools play in addressing scientific challenges relevant to biology, sustainable energy, and technologies that will fuel economic development without degrading our environment. Among the specific capability needs for advancing science and technology are tools that extract more detailed information in realistic environments (in situ or operando) at extreme conditions (pressure and temperature) and as a function of time (dynamic and time-dependent). One of the DOE workshops, Future Science Needs and Opportunities for Electron Scattering: Next Generation Instrumentation and Beyond, specifically addressed the importance of electron-based characterization methods for a wide range of energy-relevant Grand Scientific Challenges. Boosted by the electron optical advancement in the last decade, a diversity of in situ capabilities already is available in many laboratories. The obvious remaining major capability gap in electron microscopy is in the ability to make these direct in situ observations over a broad spectrum of fast (µs) to ultrafast (picosecond [ps] and faster) temporal regimes. In an effort to address current capability gaps, EMSL, the Environmental Molecular Sciences Laboratory, organized an Ultrafast Electron Microscopy Workshop, held June 14-15, 2011, with the primary goal to identify the scientific needs that could be met by creating a facility capable of a strongly improved time resolution with integrated in situ capabilities. The workshop brought together more than 40 leading scientists involved in applying and/or advancing electron microscopy to address important scientific problems of relevance to DOE’s research

Three-dimensional printing of human skeletal muscle cells: An interdisciplinary approach for studying biological systems.

Science.gov (United States)

Bagley, James R; Galpin, Andrew J

2015-01-01

Interdisciplinary exploration is vital to education in the 21st century. This manuscript outlines an innovative laboratory-based teaching method that combines elements of biochemistry/molecular biology, kinesiology/health science, computer science, and manufacturing engineering to give students the ability to better conceptualize complex biological systems. Here, we utilize technology available at most universities to print three-dimensional (3D) scale models of actual human muscle cells (myofibers) out of bioplastic materials. The same methodological approach could be applied to nearly any cell type or molecular structure. This advancement is significant because historically, two-dimensional (2D) myocellular images have proven insufficient for detailed analysis of organelle organization and morphology. 3D imaging fills this void by providing accurate and quantifiable myofiber structural data. Manipulating tangible 3D models combats 2D limitation and gives students new perspectives and alternative learning experiences that may assist their understanding. This approach also exposes learners to 1) human muscle cell extraction and isolation, 2) targeted fluorescence labeling, 3) confocal microscopy, 4) image processing (via open-source software), and 5) 3D printing bioplastic scale-models (×500 larger than the actual cells). Creating these physical models may further student's interest in the invisible world of molecular and cellular biology. Furthermore, this interdisciplinary laboratory project gives instructors of all biological disciplines a new teaching tool to foster integrative thinking. © 2015 The International Union of Biochemistry and Molecular Biology.

78 FR 57293 - Distribution of Reference Biological Standards and Biological Preparations

Science.gov (United States)

2013-09-18

... DEPARTMENT OF HEALTH AND HUMAN SERVICES 42 CFR Part 7 [Docket No. CDC-2013-0013] RIN 0920-AA52 Distribution of Reference Biological Standards and Biological Preparations AGENCY: Centers for Disease Control and Prevention (HHS/CDC), Department of Health and Human Services (HHS). ACTION: Confirmation of...

A Comprehensive Experiment for Molecular Biology: Determination of Single Nucleotide Polymorphism in Human REV3 Gene Using PCR-RFLP

Science.gov (United States)

Zhang, Xu; Shao, Meng; Gao, Lu; Zhao, Yuanyuan; Sun, Zixuan; Zhou, Liping; Yan, Yongmin; Shao, Qixiang; Xu, Wenrong; Qian, Hui

2017-01-01

Laboratory exercise is helpful for medical students to understand the basic principles of molecular biology and to learn about the practical applications of molecular biology. We have designed a lab course on molecular biology about the determination of single nucleotide polymorphism (SNP) in human REV3 gene, the product of which is a subunit of…

Advances in radiation biology: Relative radiation sensitivities of human organ systems. Volume 12

International Nuclear Information System (INIS)

Lett, J.T.; Altman, K.I.; Ehmann, U.K.; Cox, A.B.

1987-01-01

This volume is a thematically focused issue of Advances in Radiation Biology. The topic surveyed is relative radiosensitivity of human organ systems. Topics considered include relative radiosensitivities of the thymus, spleen, and lymphohemopoietic systems; relative radiosensitivities of the small and large intestine; relative rediosensitivities of the oral cavity, larynx, pharynx, and esophagus; relative radiation sensitivity of the integumentary system; dose response of the epidermal; microvascular, and dermal populations; relative radiosensitivity of the human lung; relative radiosensitivity of fetal tissues; and tolerance of the central and peripheral nervous system to therapeutic irradiation

Advances in radiation biology: Relative radiation sensitivities of human organ systems. Volume 12

Energy Technology Data Exchange (ETDEWEB)

Lett, J.T.; Altman, K.I.; Ehmann, U.K.; Cox, A.B.

1987-01-01

This volume is a thematically focused issue of Advances in Radiation Biology. The topic surveyed is relative radiosensitivity of human organ systems. Topics considered include relative radiosensitivities of the thymus, spleen, and lymphohemopoietic systems; relative radiosensitivities of the small and large intestine; relative rediosensitivities of the oral cavity, larynx, pharynx, and esophagus; relative radiation sensitivity of the integumentary system; dose response of the epidermal; microvascular, and dermal populations; relative radiosensitivity of the human lung; relative radiosensitivity of fetal tissues; and tolerance of the central and peripheral nervous system to therapeutic irradiation.

Toxicity of silver nanoparticles in biological systems: Does the complexity of biological systems matter?

Science.gov (United States)

Vazquez-Muñoz, Roberto; Borrego, Belen; Juárez-Moreno, Karla; García-García, Maritza; Mota Morales, Josué D; Bogdanchikova, Nina; Huerta-Saquero, Alejandro

2017-07-05

Currently, nanomaterials are more frequently in our daily life, specifically in biomedicine, electronics, food, textiles and catalysis just to name a few. Although nanomaterials provide many benefits, recently their toxicity profiles have begun to be explored. In this work, the toxic effects of silver nanoparticles (35nm-average diameter and Polyvinyl-Pyrrolidone-coated) on biological systems of different levels of complexity was assessed in a comprehensive and comparatively way, through a variety of viability and toxicological assays. The studied organisms included viruses, bacteria, microalgae, fungi, animal and human cells (including cancer cell lines). It was found that biological systems of different taxonomical groups are inhibited at concentrations of silver nanoparticles within the same order of magnitude. Thus, the toxicity of nanomaterials on biological/living systems, constrained by their complexity, e.g. taxonomic groups, resulted contrary to the expected. The fact that cells and virus are inhibited with a concentration of silver nanoparticles within the same order of magnitude could be explained considering that silver nanoparticles affects very primitive cellular mechanisms by interacting with fundamental structures for cells and virus alike. Copyright © 2017 Elsevier B.V. All rights reserved.

Are Prompts Provided by Electronic Books as Effective for Teaching Preschoolers a Biological Concept as Those Provided by Adults?

Science.gov (United States)

Strouse, Gabrielle A.; Ganea, Patricia A.

2016-01-01

Research Findings: Prior research indicates that shared book reading is an effective method for teaching biological concepts to young children. Adult questioning during reading enhances children's comprehension. We investigated whether adult prompting during the reading of an electronic book enhanced children's understanding of a biological…

Modeling human risk: Cell ampersand molecular biology in context

International Nuclear Information System (INIS)

1997-06-01

It is anticipated that early in the next century manned missions into outer space will occur, with a mission to Mars scheduled between 2015 and 2020. However, before such missions can be undertaken, a realistic estimation of the potential risks to the flight crews is required. One of the uncertainties remaining in this risk estimation is that posed by the effects of exposure to the radiation environment of outer space. Although the composition of this environment is fairly well understood, the biological effects arising from exposure to it are not. The reasons for this are three-fold: (1) A small but highly significant component of the radiation spectrum in outer space consists of highly charged, high energy (HZE) particles which are not routinely experienced on earth, and for which there are insufficient data on biological effects; (2) Most studies on the biological effects of radiation to date have been high-dose, high dose-rate, whereas in space, with the exception of solar particle events, radiation exposures will be low-dose, low dose-rate; (3) Although it has been established that the virtual absence of gravity in space has a profound effect on human physiology, it is not clear whether these effects will act synergistically with those of radiation exposure. A select panel will evaluate the utilizing experiments and models to accurately predict the risks associated with exposure to HZE particles. Topics of research include cellular and tissue response, health effects associated with radiation damage, model animal systems, and critical markers of Radiation response

Biological variability dominates and influences analytical variance in HPLC-ECD studies of the human plasma metabolome

Directory of Open Access Journals (Sweden)

Willett Walter C

2007-11-01

Full Text Available Abstract Background Biomarker-based assessments of biological samples are widespread in clinical, pre-clinical, and epidemiological investigations. We previously developed serum metabolomic profiles assessed by HPLC-separations coupled with coulometric array detection that can accurately identify ad libitum fed and caloric-restricted rats. These profiles are being adapted for human epidemiology studies, given the importance of energy balance in human disease. Methods Human plasma samples were biochemically analyzed using HPLC separations coupled with coulometric electrode array detection. Results We identified these markers/metabolites in human plasma, and then used them to determine which human samples represent blinded duplicates with 100% accuracy (N = 30 of 30. At least 47 of 61 metabolites tested were sufficiently stable for use even after 48 hours of exposure to shipping conditions. Stability of some metabolites differed between individuals (N = 10 at 0, 24, and 48 hours, suggesting the influence of some biological factors on parameters normally considered as analytical. Conclusion Overall analytical precision (mean median CV, ~9% and total between-person variation (median CV, ~50–70% appear well suited to enable use of metabolomics markers in human clinical trials and epidemiological studies, including studies of the effect of caloric intake and balance on long-term cancer risk.

Positioning genomics in biology education: content mapping of undergraduate biology textbooks.

Science.gov (United States)

Wernick, Naomi L B; Ndung'u, Eric; Haughton, Dominique; Ledley, Fred D

2014-12-01

Biological thought increasingly recognizes the centrality of the genome in constituting and regulating processes ranging from cellular systems to ecology and evolution. In this paper, we ask whether genomics is similarly positioned as a core concept in the instructional sequence for undergraduate biology. Using quantitative methods, we analyzed the order in which core biological concepts were introduced in textbooks for first-year general and human biology. Statistical analysis was performed using self-organizing map algorithms and conventional methods to identify clusters of terms and their relative position in the books. General biology textbooks for both majors and nonmajors introduced genome-related content after text related to cell biology and biological chemistry, but before content describing higher-order biological processes. However, human biology textbooks most often introduced genomic content near the end of the books. These results suggest that genomics is not yet positioned as a core concept in commonly used textbooks for first-year biology and raises questions about whether such textbooks, or courses based on the outline of these textbooks, provide an appropriate foundation for understanding contemporary biological science.

Advances in Electronic-Nose Technologies for the Detection of Volatile Biomarker Metabolites in the Human Breath

Directory of Open Access Journals (Sweden)

Alphus D. Wilson

2015-03-01

Full Text Available Recent advancements in the use of electronic-nose (e-nose devices to analyze human breath profiles for the presence of specific volatile metabolites, known as biomarkers or chemical bio-indicators of specific human diseases, metabolic disorders and the overall health status of individuals, are providing the potential for new noninvasive tools and techniques useful to point-of-care clinical disease diagnoses. This exciting new area of electronic disease detection and diagnosis promises to yield much faster and earlier detection of human diseases and disorders, allowing earlier, more effective treatments, resulting in more rapid patient recovery from various afflictions. E-nose devices are particularly suited for the field of disease diagnostics, because they are sensitive to a wide range of volatile organic compounds (VOCs and can effectively distinguish between different complex gaseous mixtures via analysis of electronic aroma sensor-array output profiles of volatile metabolites present in the human breath. This review provides a summary of some recent developments of electronic-nose technologies, particularly involving breath analysis, with the potential for providing many new diagnostic applications for the detection of specific human diseases associated with different organs in the body, detectable from e-nose analyses of aberrant disease-associated VOCs present in air expired from the lungs.

78 FR 20924 - Center for Biologics Evaluation and Research eSubmitter Pilot Evaluation Program for...

Science.gov (United States)

2013-04-08

..., Office of Blood Research and Review, Center for Biologics Evaluation and Research (HFM-375), Food and... assist CBER in the final development and release of this electronic program for use by industry. III... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2013-N-0248...

Ethics and methods for biological rhythm research on animals and human beings.

Science.gov (United States)

Portaluppi, Francesco; Smolensky, Michael H; Touitou, Yvan

2010-10-01

This article updates the ethical standards and methods for the conduct of high-quality animal and human biological rhythm research, which should be especially useful for new investigators of the rhythms of life. The editors of Chronobiology International adhere to and endorse the Code of Conduct and Best Practice Guidelines of the Committee On Publication Ethics (COPE), which encourages communication of such updates at regular intervals in the journal. The journal accepts papers representing original work, no part of which was previously submitted for publication elsewhere, except as brief abstracts, as well as in-depth reviews. The majority of research papers published in Chronobiology International entails animal and human investigations. The editors and readers of the journal expect authors of submitted manuscripts to have made an important contribution to the research of biological rhythms and related phenomena using ethical methods/procedures and unbiased, accurate, and honest reporting of findings. Authors of scientific papers are required to declare all potential conflicts of interest. The journal and its editors endorse compliance of investigators to the Guide for the Care and Use of Laboratory Animals of the Institute for Laboratory Animal Research of the National Research Council, relating to the conduct of ethical research on laboratory and other animals, and the principles of the Declaration of Helsinki of the World Medical Association, relating to the conduct of ethical research on human beings. The peer review of manuscripts by Chronobiology International thus includes judgment as to whether or not the protocols and methods conform to ethical standards. Authors are expected to show mastery of the basic methods and procedures of biological rhythm research and proper statistical assessment of data, including the appropriate application of time series data analyses, as briefly reviewed in this article. The journal editors strive to consistently achieve

78 FR 47319 - Fee Schedule for Reference Biological Standards and Biological Preparations

Science.gov (United States)

2013-08-05

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Centers for Disease Control and Prevention Fee Schedule for Reference Biological Standards and Biological Preparations AGENCY: Centers for Disease Control and... for Disease Control and Prevention (CDC), located within the Department of Health and Human Services...

Urgent Biophilia: Human-Nature Interactions and Biological Attractions in Disaster Resilience

Directory of Open Access Journals (Sweden)

Keith G. Tidball

2012-06-01

Full Text Available This contribution builds upon contemporary work on principles of biological attraction as well as earlier work on biophilia while synthesizing literatures on restorative environments, community-based ecological restoration, and both community and social-ecological disaster resilience. It suggests that when humans, faced with a disaster, as individuals and as communities and populations, seek engagement with nature to further their efforts to summon and demonstrate resilience in the face of a crisis, they exemplify an urgent biophilia. This urgent biophilia represents an important set of human-nature interactions in SES characterized by hazard, disaster, or vulnerability, often appearing in the 'backloop' of the adaptive cycle. The relationships that human-nature interactions have to other components within interdependent systems at many different scales may be one critical source of resilience in disaster and related contexts. In other words, the affinity we humans have for the rest of nature, the process of remembering that attraction, and the urge to express it through creation of restorative environments, which may also restore or increase ecological function, may confer resilience across multiple scales. In making this argument, the paper also represents a novel contribution to further theorizing alternatives to anthropocentric understandings of human-nature relations, and strongly makes the case for humans as part of, not separate from, ecosystems.

Knowledge Enrichment Analysis for Human Tissue- Specific Genes Uncover New Biological Insights

Directory of Open Access Journals (Sweden)

Gong Xiu-Jun

2012-06-01

Full Text Available The expression and regulation of genes in different tissues are fundamental questions to be answered in biology. Knowledge enrichment analysis for tissue specific (TS and housekeeping (HK genes may help identify their roles in biological process or diseases and gain new biological insights.In this paper, we performed the knowledge enrichment analysis for 17,343 genes in 84 human tissues using Gene Set Enrichment Analysis (GSEA and Hypergeometric Analysis (HA against three biological ontologies: Gene Ontology (GO, KEGG pathways and Disease Ontology (DO respectively.The analyses results demonstrated that the functions of most gene groups are consistent with their tissue origins. Meanwhile three interesting new associations for HK genes and the skeletal muscle tissuegenes are found. Firstly, Hypergeometric analysis against KEGG database for HK genes disclosed that three disease terms (Parkinson’s disease, Huntington’s disease, Alzheimer’s disease are intensively enriched.Secondly, Hypergeometric analysis against the KEGG database for Skeletal Muscle tissue genes shows that two cardiac diseases of “Hypertrophic cardiomyopathy (HCM” and “Arrhythmogenic right ventricular cardiomyopathy (ARVC” are heavily enriched, which are also considered as no relationship with skeletal functions.Thirdly, “Prostate cancer” is intensively enriched in Hypergeometric analysis against the disease ontology (DO for the Skeletal Muscle tissue genes, which is a much unexpected phenomenon.

Retinyl β-glucoronide: its occurrence in human serum, chemical synthesis and biological activity

International Nuclear Information System (INIS)

Barua, A.B.; Batres, R.O.; Olson, J.A.

1986-01-01

When retinol is administered to rats, retinyl and retinoyl β-glucuronides appear in the bile. Retinyl or retinoyl β-glucuronide is also synthesized in vitro when rat liver microsomes are incubated with uridinediphosphoglucuronic acid and either retinol or retinoic acid. Retinoyl β-glucuronide, a major metabolite of retinoic acid in a number of tissues, is highly active biologically, has been chemically synthesized, and is found in human blood. The physiological significance of the glucuronides of vitamin A are not known yet. To investigate further its metabolism and possible physiological role, retinyl β-glucuronide was chemically synthesized from retinol and characterized by study of its ultra-violet spectrum (γ/sub max/ 325 nm in methanol, 329 nm in water), 1 H-NMR and mass spectra. Retinyl β-glucuronide was extensively hydrolyzed by bacterial β-glucuronidase to retinol. Retinyl β-glucuronide is soluble in water and was detected in significant amounts in the serum of healthy human adults. The biological activity of synthetic retinyl β-glucuronide was determined in rats by the rat growth bioassay method

Interactions of electrons with biologically important molecules

International Nuclear Information System (INIS)

Pisklova, K.; Papp, P.; Stano, M.

2012-01-01

For the study of interactions of low-energy electrons with the molecules in the gas phase, the authors used electron-molecule cross-beam apparatus. The experiment is carried out in high vacuum, where molecules of the tested compound are inducted through a capillary. For purposes of this experiment the sample was electrically heated to 180 Deg C., giving a bundle of GlyGly molecules into the gas phase. The resulting signals can be evaluated in two different modes: mass spectrum - at continuous electron energy (e.g. 100 eV) they obtained the signal of intensity of the ions according to their mass to charge ratio; ionization and resonance spectra - for selected ion mass when the authors received the signal of intensity of the ions, depending on the energy of interacting electron.

Universe, human immortality and future human evaluation

CERN Document Server

Bolonkin, Alexander

2011-01-01

This book debates the universe, the development of new technologies in the 21st century and the future of the human race. Dr Bolonkin shows that a human soul is only the information in a person's head. He offers a new unique method for re-writing the main brain information in chips without any damage to the human brain. This is the scientific prediction of the non-biological (electronic) civilization and immortality of the human being. Such a prognosis is predicated upon a new law, discovered by the author, for the development of complex systems. According to this law, every self-copying system tends to be more complex than the previous system, provided that all external conditions remain the same. The consequences are disastrous: humanity will be replaced by a new civilization created by intellectual robots (which Dr Bolonkin refers to as "E-humans" and "E-beings"). These creatures, whose intellectual and mechanical abilities will far exceed those of man, will require neither food nor oxygen to sustain their...

An ESR study on biological dosimeters: Human hair

International Nuclear Information System (INIS)

Colak, Seyda; Ozbey, Turan

2011-01-01

In the present work, characteristic features of the radicals found in untreated, gamma and UV-irradiated and mechanical damaged human hair samples were investigated by ESR spectroscopy. Heights of the resonance peaks measured with respect to the spectrum base line were used to monitor microwave power, dose-response, storage time and temperature dependent kinetic features of the radical species contributing to the formation of recorded experimental ESR spectra. Peak heights and g-values (2.0037-2.0052) determined from recorded spectra of hair were color dependent with ΔHpp-0.47 mT. The act of cutting hair samples gene rates sulfur centered radicals which are found in the a-keratin structure of hair. The variations of the peak heights with temperature were related with the water content found in the hair samples. In the 6-1100 Gy dose range, a linear + quadratic dose-response curve was recorded for hair and the mean radiation yield (G mean ) was calculated to be 0.4. The gamma radiation induced radicals were stable for a several hours at room temperature storage conditions. Based on these findings it was concluded that human hair samples could be used as biological/personnel dosimeters and that ESR spectroscopy could be successfully used as a potential technique for monitoring its dosimetric behaviours.

Earthing: Health Implications of Reconnecting the Human Body to the Earth's Surface Electrons

International Nuclear Information System (INIS)

Chevalier, G.; Chevalier, G.; Sinatra, S.T.; Oschman, J.L.; Sokal, K.; Sokal, P.

2012-01-01

Environmental medicine generally addresses environmental factors with a negative impact on human health. However, emerging scientific research has revealed a surprisingly positive and overlooked environmental factor on health: direct physical contact with the vast supply of electrons on the surface of the Earth. Modern lifestyle separates humans from such contact. The research suggests that this disconnect may be a major contributor to physiological dysfunction and un wellness. Reconnection with the Earth's electrons has been found to promote intriguing physiological changes and subjective reports of well-being. Earthing (or grounding) refers to the discovery of benefits including better sleep and reduced pain from walking barefoot outside or sitting, working, or sleeping indoors connected to conductive systems that transfer the Earth's electrons from the ground into the body. This paper reviews the earthing research and the potential of earthing as a simple and easily accessed global modality of significant clinical importance

Screening vaccine formulations for biological activity using fresh human whole blood.

Science.gov (United States)

Brookes, Roger H; Hakimi, Jalil; Ha, Yukyung; Aboutorabian, Sepideh; Ausar, Salvador F; Hasija, Manvi; Smith, Steven G; Todryk, Stephen M; Dockrell, Hazel M; Rahman, Nausheen

2014-01-01

Understanding the relevant biological activity of any pharmaceutical formulation destined for human use is crucial. For vaccine-based formulations, activity must reflect the expected immune response, while for non-vaccine therapeutic agents, such as monoclonal antibodies, a lack of immune response to the formulation is desired. During early formulation development, various biochemical and biophysical characteristics can be monitored in a high-throughput screening (HTS) format. However, it remains impractical and arguably unethical to screen samples in this way for immunological functionality in animal models. Furthermore, data for immunological functionality lag formulation design by months, making it cumbersome to relate back to formulations in real-time. It is also likely that animal testing may not accurately reflect the response in humans. For a more effective formulation screen, a human whole blood (hWB) approach can be used to assess immunological functionality. The functional activity relates directly to the human immune response to a complete formulation (adjuvant/antigen) and includes adjuvant response, antigen response, adjuvant-modulated antigen response, stability, and potentially safety. The following commentary discusses the hWB approach as a valuable new tool to de-risk manufacture, formulation design, and clinical progression.

Biological effects on human health due to radiofrequency/microwave exposure

DEFF Research Database (Denmark)

Breckenkamp, Jürgen; Berg, Gabriele; Blettner, Maria

2003-01-01

We evaluated the methods and results of nine cohort studies dealing with the biological effects on human health from exposure to radiofrequencies/microwaves, published between 1980 and 2002. The size of the cohorts varied between 304 (3,362 person years) and nearly 200,000 persons (2.7 million......, however, inconsistent. The most important limitations of the studies were the lack of measurements referring to past and current exposures and, thus, the unknown details on actual exposure, the use of possibly biased data as well as the lack of adjustment for potential confounders and the use of indirect...

Biology, diagnosis and treatment of canine appendicular osteosarcoma: similarities and differences with human osteosarcoma.

Science.gov (United States)

Morello, Emanuela; Martano, Marina; Buracco, Paolo

2011-09-01

Osteosarcoma (OSA) is the most common primary bone tumour in dogs. The appendicular locations are most frequently involved and large to giant breed dogs are commonly affected, with a median age of 7-8 years. OSA is a locally invasive neoplasm with a high rate of metastasis, mostly to the lungs. Due to similarities in biology and treatment of OSA in dogs and humans, canine OSA represents a valid and important tumour model. Differences between canine and human OSAs include the age of occurrence (OSA is most commonly an adolescent disease in humans), localisation (the stifle is the most common site of localisation in humans) and limited use of neoadjuvant chemotherapy in canine OSA. Copyright © 2010 Elsevier Ltd. All rights reserved.

X-ray Microscopy as an Approach to Increasing Accuracy and Efficiency of Serial Block-face Imaging for Correlated Light and Electron Microscopy of Biological Specimens

OpenAIRE

Bushong, Eric A.; Johnson, Donald D.; Kim, Keun-Young; Terada, Masako; Hatori, Megumi; Peltier, Steven T.; Panda, Satchidananda; Merkle, Arno; Ellisman, Mark H.

2014-01-01

The recently developed three-dimensional electron microscopic (EM) method of serial block-face scanning electron microscopy (SBEM) has rapidly established itself as a powerful imaging approach. Volume EM imaging with this scanning electron microscopy (SEM) method requires intense staining of biological specimens with heavy metals to allow sufficient back-scatter electron signal and also to render specimens sufficiently conductive to control charging artifacts. These more extreme heavy metal s...

Theoretical description of protein field effects on electronic excitations of biological chromophores

International Nuclear Information System (INIS)

Varsano, Daniele; Caprasecca, Stefano; Coccia, Emanuele

2017-01-01

Photoinitiated phenomena play a crucial role in many living organisms. Plants, algae, and bacteria absorb sunlight to perform photosynthesis, and convert water and carbon dioxide into molecular oxygen and carbohydrates, thus forming the basis for life on Earth. The vision of vertebrates is accomplished in the eye by a protein called rhodopsin, which upon photon absorption performs an ultrafast isomerisation of the retinal chromophore, triggering the signal cascade. Many other biological functions start with the photoexcitation of a protein-embedded pigment, followed by complex processes comprising, for example, electron or excitation energy transfer in photosynthetic complexes. The optical properties of chromophores in living systems are strongly dependent on the interaction with the surrounding environment (nearby protein residues, membrane, water), and the complexity of such interplay is, in most cases, at the origin of the functional diversity of the photoactive proteins. The specific interactions with the environment often lead to a significant shift of the chromophore excitation energies, compared with their absorption in solution or gas phase. The investigation of the optical response of chromophores is generally not straightforward, from both experimental and theoretical standpoints; this is due to the difficulty in understanding diverse behaviours and effects, occurring at different scales, with a single technique. In particular, the role played by ab initio calculations in assisting and guiding experiments, as well as in understanding the physics of photoactive proteins, is fundamental. At the same time, owing to the large size of the systems, more approximate strategies which take into account the environmental effects on the absorption spectra are also of paramount importance. Here we review the recent advances in the first-principle description of electronic and optical properties of biological chromophores embedded in a protein environment. We show

Theoretical description of protein field effects on electronic excitations of biological chromophores

Science.gov (United States)

Varsano, Daniele; Caprasecca, Stefano; Coccia, Emanuele

2017-01-01

Photoinitiated phenomena play a crucial role in many living organisms. Plants, algae, and bacteria absorb sunlight to perform photosynthesis, and convert water and carbon dioxide into molecular oxygen and carbohydrates, thus forming the basis for life on Earth. The vision of vertebrates is accomplished in the eye by a protein called rhodopsin, which upon photon absorption performs an ultrafast isomerisation of the retinal chromophore, triggering the signal cascade. Many other biological functions start with the photoexcitation of a protein-embedded pigment, followed by complex processes comprising, for example, electron or excitation energy transfer in photosynthetic complexes. The optical properties of chromophores in living systems are strongly dependent on the interaction with the surrounding environment (nearby protein residues, membrane, water), and the complexity of such interplay is, in most cases, at the origin of the functional diversity of the photoactive proteins. The specific interactions with the environment often lead to a significant shift of the chromophore excitation energies, compared with their absorption in solution or gas phase. The investigation of the optical response of chromophores is generally not straightforward, from both experimental and theoretical standpoints; this is due to the difficulty in understanding diverse behaviours and effects, occurring at different scales, with a single technique. In particular, the role played by ab initio calculations in assisting and guiding experiments, as well as in understanding the physics of photoactive proteins, is fundamental. At the same time, owing to the large size of the systems, more approximate strategies which take into account the environmental effects on the absorption spectra are also of paramount importance. Here we review the recent advances in the first-principle description of electronic and optical properties of biological chromophores embedded in a protein environment. We show

The Science and Issues of Human DNA Polymoprhisms: A Training Workshop for High School Biology Teachers

Energy Technology Data Exchange (ETDEWEB)

David. A Micklos

2006-10-30

This project achieved its goal of implementing a nationwide training program to introduce high school biology teachers to the key uses and societal implications of human DNA polymorphisms. The 2.5-day workshop introduced high school biology faculty to a laboratory-based unit on human DNA polymorphisms – which provides a uniquely personal perspective on the science and Ethical, Legal and Social Implications (ELSI) of the Human Genome Project. As proposed, 12 workshops were conducted at venues across the United States. The workshops were attended by 256 high school faculty, exceeding proposed attendance of 240 by 7%. Each workshop mixed theoretical, laboratory, and computer work with practical and ethical implications. Program participants learned simplified lab techniques for amplifying three types of chromosomal polymorphisms: an Alu insertion (PV92), a VNTR (pMCT118/D1S80), and single nucleotide polymorphisms (SNPs) in the mitochondrial control region. These polymorphisms illustrate the use of DNA variations in disease diagnosis, forensic biology, and identity testing - and provide a starting point for discussing the uses and potential abuses of genetic technology. Participants also learned how to use their Alu and mitochondrial data as an entrée to human population genetics and evolution. Our work to simplify lab techniques for amplifying human DNA polymorphisms in educational settings culminated with the release in 1998 of three Advanced Technology (AT) PCR kits by Carolina Biological Supply Company, the nation’s oldest educational science supplier. The kits use a simple 30-minute method to isolate template DNA from hair sheaths or buccal cells and streamlined PCR chemistry based on Pharmacia Ready-To-Go Beads, which incorporate Taq polymerase, deoxynucleotide triphosphates, and buffer in a freeze-dried pellet. These kits have greatly simplified teacher implementation of human PCR labs, and their use is growing at a rapid pace. Sales of human polymorphism

The Science and Issues of Human DNA Polymorphisms: A Training Workshop for High School Biology Teachers

Energy Technology Data Exchange (ETDEWEB)

Micklos, David A.

2006-10-30

This project achieved its goal of implementing a nationwide training program to introduce high school biology teachers to the key uses and societal implications of human DNA polymorphisms. The 2.5-day workshop introduced high school biology faculty to a laboratory-based unit on human DNA polymorphisms â which provides a uniquely personal perspective on the science and Ethical, Legal and Social Implications (ELSI) of the Human Genome Project. As proposed, 12 workshops were conducted at venues across the United States. The workshops were attended by 256 high school faculty, exceeding proposed attendance of 240 by 7%. Each workshop mixed theoretical, laboratory, and computer work with practical and ethical implications. Program participants learned simplified lab techniques for amplifying three types of chromosomal polymorphisms: an Alu insertion (PV92), a VNTR (pMCT118/D1S80), and single nucleotide polymorphisms (SNPs) in the mitochondrial control region. These polymorphisms illustrate the use of DNA variations in disease diagnosis, forensic biology, and identity testing - and provide a starting point for discussing the uses and potential abuses of genetic technology. Participants also learned how to use their Alu and mitochondrial data as an entrée to human population genetics and evolution. Our work to simplify lab techniques for amplifying human DNA polymorphisms in educational settings culminated with the release in 1998 of three Advanced Technology (AT) PCR kits by Carolina Biological Supply Company, the nationâÂÂs oldest educational science supplier. The kits use a simple 30-minute method to isolate template DNA from hair sheaths or buccal cells and streamlined PCR chemistry based on Pharmacia Ready-To-Go Beads, which incorporate Taq polymerase, deoxynucleotide triphosphates, and buffer in a freeze-dried pellet. These kits have greatly simplified teacher implementation of human PCR labs, and their use is growing at a rapid pace. Sales of human

Laws and regulations associated with ownership of human biological material in South Africa

Directory of Open Access Journals (Sweden)

Kishen Mahesh

2015-05-01

Full Text Available Ownership with regard to human biological material (HBM is addressed to some extent within South African law, specifically in chapter eight of the National Health Act (NHA and its associated regulations. However, members of the legal fraternity struggle to conceptualise ownership of such materials without objectifying a person or people and risking reducing such individuals to a state of property. This then infers a reduction in human dignity by rendering one-self or parts of that same self as a commodity. The complexity of the issue raises much debate both legally as well as ethically. 

Radioimmunological assay of the biologically active fragment of the human parathyroid hormone

International Nuclear Information System (INIS)

Desplan, C.; Jullienne, A.; Raulais, D.; Rivaille, P.; Barlet, J.P.; Moukthar, M.S.; Milhaud, G.

1977-01-01

The authors describe a RIA of the biologically active fraction (N-terminal) of human parathyroid hormone. This homologous test uses antibodies obtained in goats against a N-terminal 1-34 fragment of hPTH synthetised according to the method of Niall and Coll. In this system, natural hPTH of different origin (extracts from parathyroid adenomas, adenomal culture medium, hyperparathyroid plasma, adsorption chromatography extract of normal human plasma) behaved in the same manner as the synthetic reference hormone 1-34 hPTHN. The RIA detected PTH in 65% of the normal subjects and distinguished the normal values from the values of hyperparathyroid patients, which makes it suitable for clinical practice. (AJ) [de

Indicative and complementary effects of human biological indicators for heavy metal exposure assessment.

Science.gov (United States)

Xing, Ruiya; Li, Yonghua; Zhang, Biao; Li, Hairong; Liao, Xiaoyong

2017-10-01

Although human biological indicators have been widely utilized for biomonitoring environmental pollutants in health exposure assessment, the relationship between internal and external exposure has not yet been adequately established. In this study, we collected and analyzed 61 rice, 56 pepper, and 58 soil samples, together with 107 hair, 107 blood, and 107 urine samples from residents living in selected intensive mining areas in China. Concentrations of most of the four elements considered (Pb, Cd, Hg, and Se) exceeded national standards, implying high exposure risk in the study areas. Regression analysis also revealed a correlation (0.33, P human hair (as well as in human blood); to some extent, Pb content in hair and blood could therefore be used to characterize external Pb exposure. The correlation between Hg in rice and in human hair (up to 0.5, P human hair for Hg exposure. A significant correlation was also noted between concentrations of some elements in different human samples, for example, between Hg in hair and blood (0.641, P assessing heavy metal exposure.

Radiation dosimetry in human bone using electron paramagnetic resonance

International Nuclear Information System (INIS)

Breen, S.L.

1995-01-01

Accurate measurements of dose in bone are required in order to improve the dosimetry of systemic radiotherapy for osseous metastases. Bone is an integrating dosimeter which records the radiation history of the skeleton. During irradiation, electrons become trapped in the crystalline component of bone mineral (hydroxyapatite). The traps are very stable; at room temperature, emptying of the traps occurs with a half-life of many years. The population of trapped unpaired electrons is proportional to the radiation dose administered to the bone and can be measured in excised bone samples using electron paramagnetic resonance (EPR). EPR spectra of synthetic hydroxyapatite, irradiated with Co-60, were obtained at room temperature and at 77 K. At room temperature, the radiation-induced signal, with a g-value of 2.001 ± 0.001 increased linearly with absorbed dose above a lower threshold of 3 Gy, up to doses of 200 Gy. In contrast with pure hydroxyapatite, EPR spectra of excised human bone showed a broad 'native' signal, due to the organic component of bone, which masks the dosimetrically important signal. This native signal is highly variable from sample to sample and precludes the use of EPR as an absolute dosimetry technique. However, after subtraction of the background signal, irradiated human bone showed a linear response with a lower limit of measurement similar to that of synthetic hydroxyapatite. Bone is an in vivo linear dosimeter which can be exploited to develop accurate estimates of the radiation dose delivered during systemic radiotherapy and teletherapy. However, improved sensitivity of the EPR dosimetry technique is necessary before it can be applied reliably in clinical situations. (author)

Biology and relevance of human acute myeloid leukemia stem cells.

Science.gov (United States)

Thomas, Daniel; Majeti, Ravindra

2017-03-23

Evidence of human acute myeloid leukemia stem cells (AML LSCs) was first reported nearly 2 decades ago through the identification of rare subpopulations of engrafting cells in xenotransplantation assays. These AML LSCs were shown to reside at the apex of a cellular hierarchy that initiates and maintains the disease, exhibiting properties of self-renewal, cell cycle quiescence, and chemoresistance. This cancer stem cell model offers an explanation for chemotherapy resistance and disease relapse and implies that approaches to treatment must eradicate LSCs for cure. More recently, a number of studies have both refined and expanded our understanding of LSCs and intrapatient heterogeneity in AML using improved xenotransplant models, genome-scale analyses, and experimental manipulation of primary patient cells. Here, we review these studies with a focus on the immunophenotype, biological properties, epigenetics, genetics, and clinical associations of human AML LSCs and discuss critical questions that need to be addressed in future research. © 2017 by The American Society of Hematology.

Soft Electronics Enabled Ergonomic Human-Computer Interaction for Swallowing Training

Science.gov (United States)

Lee, Yongkuk; Nicholls, Benjamin; Sup Lee, Dong; Chen, Yanfei; Chun, Youngjae; Siang Ang, Chee; Yeo, Woon-Hong

2017-04-01

We introduce a skin-friendly electronic system that enables human-computer interaction (HCI) for swallowing training in dysphagia rehabilitation. For an ergonomic HCI, we utilize a soft, highly compliant (“skin-like”) electrode, which addresses critical issues of an existing rigid and planar electrode combined with a problematic conductive electrolyte and adhesive pad. The skin-like electrode offers a highly conformal, user-comfortable interaction with the skin for long-term wearable, high-fidelity recording of swallowing electromyograms on the chin. Mechanics modeling and experimental quantification captures the ultra-elastic mechanical characteristics of an open mesh microstructured sensor, conjugated with an elastomeric membrane. Systematic in vivo studies investigate the functionality of the soft electronics for HCI-enabled swallowing training, which includes the application of a biofeedback system to detect swallowing behavior. The collection of results demonstrates clinical feasibility of the ergonomic electronics in HCI-driven rehabilitation for patients with swallowing disorders.

Mechanically Compliant Electronic Materials for Wearable Photovoltaics and Human-Machine Interfaces

Science.gov (United States)

O'Connor, Timothy Francis, III

Applications of stretchable electronic materials for human-machine interfaces are described herein. Intrinsically stretchable organic conjugated polymers and stretchable electronic composites were used to develop stretchable organic photovoltaics (OPVs), mechanically robust wearable OPVs, and human-machine interfaces for gesture recognition, American Sign Language Translation, haptic control of robots, and touch emulation for virtual reality, augmented reality, and the transmission of touch. The stretchable and wearable OPVs comprise active layers of poly-3-alkylthiophene:phenyl-C61-butyric acid methyl ester (P3AT:PCBM) and transparent conductive electrodes of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) and devices could only be fabricated through a deep understanding of the connection between molecular structure and the co-engineering of electronic performance with mechanical resilience. The talk concludes with the use of composite piezoresistive sensors two smart glove prototypes. The first integrates stretchable strain sensors comprising a carbon-elastomer composite, a wearable microcontroller, low energy Bluetooth, and a 6-axis accelerometer/gyroscope to construct a fully functional gesture recognition glove capable of wirelessly translating American Sign Language to text on a cell phone screen. The second creates a system for the haptic control of a 3D printed robot arm, as well as the transmission of touch and temperature information.

Alliances in Human Biology: The Harvard Committee on Industrial Physiology, 1929-1939.

Science.gov (United States)

Oakes, Jason

2015-08-01

In 1929 the newly-reorganized Rockefeller Foundation funded the work of a cross-disciplinary group at Harvard University called the Committee on Industrial Physiology (CIP). The committee's research and pedagogical work was oriented towards different things for different members of the alliance. The CIP program included a research component in the Harvard Fatigue Laboratory and Elton May's interpretation of the Hawthorne Studies; a pedagogical aspect as part of Wallace Donham's curriculum for Harvard Business School; and Lawrence Henderson's work with the Harvard Pareto Circle, his course Sociology 23, and the Harvard Society of Fellows. The key actors within the CIP alliance shared a concern with training men for elite careers in government service, business leadership, and academic prominence. But the first communications between the CIP and the Rockefeller Foundation did not emphasize training in human biology. Instead, the CIP presented itself as a coordinating body that would be able to organize all the varied work going on at Harvard that did not fit easily into one department, and it was on this basis that the CIP became legible to the President of Harvard, A. Lawrence Lowell, and to Rockefeller's Division of Social Sciences. The members of the CIP alliance used the term human biology for this project of research, training and institutional coordination.

Is synthetic biology mechanical biology?

Science.gov (United States)

Holm, Sune

2015-12-01

A widespread and influential characterization of synthetic biology emphasizes that synthetic biology is the application of engineering principles to living systems. Furthermore, there is a strong tendency to express the engineering approach to organisms in terms of what seems to be an ontological claim: organisms are machines. In the paper I investigate the ontological and heuristic significance of the machine analogy in synthetic biology. I argue that the use of the machine analogy and the aim of producing rationally designed organisms does not necessarily imply a commitment to mechanical biology. The ideal of applying engineering principles to biology is best understood as expressing recognition of the machine-unlikeness of natural organisms and the limits of human cognition. The paper suggests an interpretation of the identification of organisms with machines in synthetic biology according to which it expresses a strategy for representing, understanding, and constructing living systems that are more machine-like than natural organisms.

Ultrastable gold substrates: Properties of a support for high-resolution electron cryomicroscopy of biological specimens

Science.gov (United States)

Russo, Christopher J.; Passmore, Lori A.

2016-01-01

Electron cryomicroscopy (cryo-EM) allows structure determination of a wide range of biological molecules and specimens. All-gold supports improve cryo-EM images by reducing radiation-induced motion and image blurring. Here we compare the mechanical and electrical properties of all-gold supports to amorphous carbon foils. Gold supports are more conductive, and have suspended foils that are not compressed by differential contraction when cooled to liquid nitrogen temperatures. These measurements show how the choice of support material and geometry can reduce specimen movement by more than an order of magnitude during low-dose imaging. We provide methods for fabrication of all-gold supports and preparation of vitrified specimens. We also analyse illumination geometry for optimal collection of high resolution, low-dose data. Together, the support structures and methods herein can improve the resolution and quality of images from any electron cryomicroscope. PMID:26592474

Investigations in space-related molecular biology. [cryo-electron microscopic and diffraction studies on terrestrial and extraterrestrial specimens

Science.gov (United States)

Fernandez-Moran, H.; Pritzker, A. N.

1974-01-01

Improved instrumentation and preparation techniques for high resolution, high voltage cryo-electron microscopic and diffraction studies on terrestrial and extraterrestrial specimens are reported. Computer correlated ultrastructural and biochemical work on hydrated and dried cell membranes and related biological systems provided information on membrane organization, ice crystal formation and ordered water, RNA virus linked to cancer, lunar rock samples, and organometallic superconducting compounds. Apollo 11, 12, 14, and 15 specimens were analyzed

Preparation of biologically active 32P-labeled human relaxin. Displaceable binding to rat uterus, cervix, and brain

International Nuclear Information System (INIS)

Osheroff, P.L.; Ling, V.T.; Vandlen, R.L.; Cronin, M.J.; Lofgren, J.A.

1990-01-01

Relaxin is a member of the insulin family of polypeptide hormones and is known to exert its biological effects on various parts of the mammalian reproductive system. Biologically active human relaxin has been chemically synthesized based on the nucleotide sequence obtained from an ovarian cDNA clone. In the present study synthetic human relaxin was radiolabled by phosphorylation with cAMP-dependent protein kinase and [gamma-32P]ATP to a specific activity of 5000 Ci/mmol. The phosphorylated relaxin was purified on cation exchange high performance liquid chromatography and was shown to co-migrate with relaxin on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Mass spectrometry revealed a single phosphorylated site on the B chain of relaxin. The 32P-relaxin was able to bind to a goat anti-relaxin antibody, and this binding could be displaced by unlabeled relaxin in a concentration-dependent manner. A comparison of the concentration responses of cellular cAMP production stimulated by relaxin and phosphorylated relaxin in a primary human uterine cell line showed that phosphorylation did not affect the in vitro biological efficacy of relaxin. This made it suitable for in situ autoradiographic localization of relaxin binding sites in rat uterine, cervical, and brain tissue sections. Displacement of the binding of 100 pM 32P-relaxin by 100, 10, and 3 nM unlabeled relaxin, but not by 100 nM insulin, insulin-like growth factor-I, and an insulin-like growth factor-I analog, demonstrated the high affinity and specificity of such binding. We conclude that 32P-labeled human relaxin is biologically and immunologically active and that this novel probe binds reversibly and with high affinity to classical (e.g. uterus) and unpredicted (e.g. brain) tissues

Removal of diclofenac from surface water by electron beam irradiation combined with a biological aerated filter

Science.gov (United States)

He, Shijun; Wang, Jianlong; Ye, Longfei; Zhang, Youxue; Yu, Jiang

2014-12-01

The degradation of DCF was investigated in aqueous solution by using electron beam (EB) technology. When the initial concentration was between 10 and 40 mg/L, almost 100% of the DCF was degraded at a dose of 0.5 kGy. However, only about 6.5% of DCF was mineralized even at 2 kGy according to total organic carbon (TOC) measurements. A combined process of EB and biological aerated filter (BAF) was therefore developed to enhance the treatment of DCF contaminated surface water. The effluent quality of combined process was substantially improved by EB pretreatment due to the degradation of DCF and related intermediates. Both irradiation and biological treatment reduced the toxicity of the treated water. The experimental results showed that EB is effective for removing DCF from artificial aqueous solution and real surface water.

Three-dimensional distributions of elements in biological samples by energy-filtered electron tomography

Energy Technology Data Exchange (ETDEWEB)

Leapman, R.D.; Kocsis, E.; Zhang, G.; Talbot, T.L.; Laquerriere, P

2004-07-15

By combining electron tomography with energy-filtered electron microscopy, we have shown the feasibility of determining the three-dimensional distributions of phosphorus in biological specimens. Thin sections of the nematode, Caenorhabditis elegans were prepared by high-pressure freezing, freeze-substitution and plastic embedding. Images were recorded at energy losses above and below the phosphorus L{sub 2,3} edge using a post-column imaging filter operating at a beam energy of 120 keV. The unstained specimens exhibited minimal contrast in bright-field images. After it was determined that the specimen was sufficiently thin to allow two-window ratio imaging of phosphorus, pairs of pre-edge and post-edge images were acquired in series over a tilt range of {+-}55 deg. at 5 deg. increments for two orthogonal tilt axes. The projected phosphorus distributions were aligned using the pre-edge images that contained inelastic contrast from colloidal gold particles deposited on the specimen surface. A reconstruction and surface rendering of the phosphorus distribution clearly revealed features 15-20 nm in diameter, which were identified as ribosomes distributed along the stacked membranes of endoplasmic reticulum and in the cytoplasm. The sensitivity of the technique was estimated at <35 phosphorus atoms per voxel based on the known total ribosomal phosphorus content of approximately 7000 atoms. Although a high electron dose of approximately 10{sup 7} e/nm{sup 2} was required to record two-axis tilt series, specimens were sufficiently stable to allow image alignment and tomographic reconstruction.

New developments in high field electron paramagnetic resonance with applications in structural biology

International Nuclear Information System (INIS)

Bennati, Marina; Prisner, Thomas F

2005-01-01

Recent developments in microwave technologies have led to a renaissance of electron paramagnetic resonance (EPR) due to the implementation of new spectrometers operating at frequencies ≥90 GHz. EPR at high fields and high frequencies (HF-EPR) has been established up to THz (very high frequency (VHF) EPR) in continuous wave (cw) operation and up to about 300 GHz in pulsed operation. To date, its most prominent application field is structural biology. This review article first gives an overview of the theoretical basics and the technical aspects of HF-EPR methodologies, such as cw and pulsed HF-EPR, as well as electron nuclear double resonance at high fields (HF-ENDOR). In the second part, the article illustrates different application areas of HF-EPR in studies of protein structure and function. In particular, HF-EPR has delivered essential contributions to disentangling complex spectra of radical cofactors or reaction intermediates in photosynthetic reaction centres, radical enzymes (such as ribonucleotide reductase) and in metalloproteins. Furthermore, HF-EPR combined with site-directed spin labelling in membranes and soluble proteins provides new methods of investigating complex molecular dynamics and intermolecular distances

Effect of low oxygen tension on the biological characteristics of human bone marrow mesenchymal stem cells

OpenAIRE

Kim, Dae Seong; Ko, Young Jong; Lee, Myoung Woo; Park, Hyun Jin; Park, Yoo Jin; Kim, Dong-Ik; Sung, Ki Woong; Koo, Hong Hoe; Yoo, Keon Hee

2016-01-01

Culture of mesenchymal stem cells (MSCs) under ambient conditions does not replicate the low oxygen environment of normal physiological or pathological states and can result in cellular impairment during culture. To overcome these limitations, we explored the effect of hypoxia (1 % O2) on the biological characteristics of MSCs over the course of different culture periods. The following biological characteristics were examined in human bone marrow-derived MSCs cultured under hypoxia for 8 week...

Development of biological treatment known as SBR process for supporting radiation treatment of industrial wastewater using electron beam

International Nuclear Information System (INIS)

Khomsaton Abu Bakar; Siti Aishah Hashim; Zulkafli Ghazali; Khairul Zaman Dahlan; Ismail Yaziz

2005-01-01

Electron beam irradiation of wastewater is capable of degrading stable non-biodegradable compound. However it requires high dose and in turn increase the cost of operation. A combination of irradiation and biological treatment is expected to overcome this problem. In this study, the treatment system will use a biological process known as Sequencing Batch Reactor (SBR). The SBR will be developed in a series and each series consist of reaction tank and clarifier tank. Filling and reaction step will occur in reaction tank while settling, decanting and idling step will ensue in the clarifier tank. The process is designed as such to enable rapid and simultaneous analysis on treated sample in order to achieve reliable results. (Author)

Translational environmental biology: cell biology informing conservation.

Science.gov (United States)

Traylor-Knowles, Nikki; Palumbi, Stephen R

2014-05-01

Typically, findings from cell biology have been beneficial for preventing human disease. However, translational applications from cell biology can also be applied to conservation efforts, such as protecting coral reefs. Recent efforts to understand the cell biological mechanisms maintaining coral health such as innate immunity and acclimatization have prompted new developments in conservation. Similar to biomedicine, we urge that future efforts should focus on better frameworks for biomarker development to protect coral reefs. Copyright © 2014 Elsevier Ltd. All rights reserved.

78 FR 12760 - Guidance for Industry on Labeling for Human Prescription Drug and Biological Products...

Science.gov (United States)

2013-02-25

...--Implementing the Physician Labeling Rule Content and Format Requirements; Availability AGENCY: Food and Drug...--Implementing the PLR Content and Format Requirements.'' This guidance is intended to assist applicants in complying with the content and format requirements of labeling for human prescription drug and biological...

General Biology Syllabus.

Science.gov (United States)

Hunter, Scott; Watthews, Thomas

This syllabus has been developed as an alternative to Regents biology and is intended for the average student who could benefit from an introductory biology course. It is divided into seven major units dealing with, respectively: (1) similarities among living things; (2) human biology (focusing on nutrition, transport, respiration, excretion, and…

Surface Immobilized His-tagged Azurin as a Model Interface for the Investigation of Vectorial Electron Transfer in Biological Systems

International Nuclear Information System (INIS)

Casalini, Stefano; Berto, Marcello; Kovtun, Alessandro; Operamolla, Alessandra; Di Rocco, Giulia; Facci, Paolo; Liscio, Andrea; Farinola, Gianluca M.; Borsari, Marco; Bortolotti, Carlo A.

2015-01-01

A model system for the electrochemical investigation of vectorial electron transfer in biological systems was designed, assembled and characterized. Gold electrodes, functionalized with a -OCH_3 terminated, aromatic self-assembled monolayer, were used as a substrate for the adsorption of variants of copper-containing, redox metalloprotein azurin. The engineered azurin bears a polyhistidine tag at its C-terminus. Thanks to the presence of the solvent exposed tag, which chelates Cu"2"+ ions in solution, we introduced an exogenous redox centre. The different reduction potentials of the two redox centres and their positioning with respect to the surface are such that electron transfer from the exogenous copper centre and the electrode is mediated by the native azurin active site, closely paralleling electron transfer processes in naturally occurring multicentre metalloproteins.

Bright field electron microscopy of biological specimens

International Nuclear Information System (INIS)

Johansen, B.V.

1976-01-01

A preirradiation procedure is described which preserves negatively stained morphological features in bright field electron micrographs to a resolution of about 1.2 nm. Prior to microscopy the pre-irradiation dose (1.6 x 10 -3 C cm -2 ) is given at low electron optical magnification at five different areas on the grid (the centre plus four 'corners'). This pre-irradiation can be measured either with a Faraday cage or through controlled exposure-developing conditions. Uranyl formate stained T2 bacteriophages and stacked disk aggregates of Tobacco Mosaic Virus (TMV) protein served as test objects. A comparative study was performed on specimens using either the pre-irradiation procedure or direct irradiation by the 'minimum beam exposure' technique. Changes in the electron diffraction pattern of the stain-protein complex and the disappearance of certain morphological features in the specimens were both used in order to compare the pre-irradiation method with the direct exposure technique. After identical electron exposures the pre-irradiation approach gave a far better preservation of specimen morphology. Consequently this procedure gives the microscopist more time to select and focus appropriate areas for imaging before deteriorations take place. The investigation also suggested that microscopy should be carried out between 60,000 and 100,000 times magnification. Within this magnification range, it is possible to take advantage of the phase contrast transfer characteristics of the objective lens while the electron load on the object is kept at a moderate level. Using the pre-irradiation procedure special features of the T2 bacteriophage morphology could be established. (author)

MATLAB Algorithms for Rapid Detection and Embedding of Palindrome and Emordnilap Electronic Watermarks in Simulated Chemical and Biological Image Data

National Research Council Canada - National Science Library

Robbins, Ronny C

2004-01-01

.... This is similar to words such as STOP which when flipped left right gives the new word POTS. Emordnilap is palindrome spelled backwards. This paper explores the use of MATLAB algorithms in the rapid detection and embedding of palindrome and emordnilap electronic watermarks in simulated chemical and biological Image Data.

Oxidation of the FAD cofactor to the 8-formyl-derivative in human electron-transferring flavoprotein

Science.gov (United States)

Augustin, Peter; Toplak, Marina; Fuchs, Katharina; Gerstmann, Eva Christine; Prassl, Ruth; Winkler, Andreas; Macheroux, Peter

2018-01-01

The heterodimeric human (h) electron-transferring flavoprotein (ETF) transfers electrons from at least 13 different flavin dehydrogenases to the mitochondrial respiratory chain through a non-covalently bound FAD cofactor. Here, we describe the discovery of an irreversible and pH-dependent oxidation of the 8α-methyl group to 8-formyl-FAD (8f-FAD), which represents a unique chemical modification of a flavin cofactor in the human flavoproteome. Furthermore, a set of hETF variants revealed that several conserved amino acid residues in the FAD-binding pocket of electron-transferring flavoproteins are required for the conversion to the formyl group. Two of the variants generated in our study, namely αR249C and αT266M, cause glutaric aciduria type II, a severe inherited disease. Both of the variants showed impaired formation of 8f-FAD shedding new light on the potential molecular cause of disease development. Interestingly, the conversion of FAD to 8f-FAD yields a very stable flavin semiquinone that exhibited slightly lower rates of electron transfer in an artificial assay system than hETF containing FAD. In contrast, the formation of 8f-FAD enhanced the affinity to human dimethylglycine dehydrogenase 5-fold, indicating that formation of 8f-FAD modulates the interaction of hETF with client enzymes in the mitochondrial matrix. Thus, we hypothesize that the FAD cofactor bound to hETF is subject to oxidation in the alkaline (pH 8) environment of the mitochondrial matrix, which may modulate electron transport between client dehydrogenases and the respiratory chain. This discovery challenges the current concepts of electron transfer processes in mitochondria. PMID:29301933

Confronting actual influence of radiation on human bodies and biological defense mechanism

International Nuclear Information System (INIS)

Matsubara, Junko

2012-01-01

After the accident at Fukushima Daiichi Nuclear Power Plant of Tokyo Electric Power Company, social, economical, psychological pressures on local residents and fears of radiation among the general public have not been resolved. Based on the assumption that the negligence of specialists to clearly explain the influence of radiation on human bodies to the general public is the factor for above mentioned pressures and fears, the influence of radiation from a realistic view was discussed. The topics covered are: (1) understanding the meaning of radiation regulation, (2) radiation and threshold values, (3) actual influence of low-dose radiation, (4) chemical and biological defense in defense mechanism against radiation, (5) problems raised by Fukushima Daiichi nuclear accident. Furthermore, the article explains the principles and the applications of biological defense function activation, and suggested that self-help efforts to fight against stress are from now on. (S.K.)

Electro-induced reactions of biologically important molecules

International Nuclear Information System (INIS)

Kocisek, J.

2010-01-01

The thesis presents the results of research activities in the field of electron interactions with biologically relevant molecules which was carried out during my PhD studies at the Department of Experimental Physics, Comenius University in Bratislava. Electron induced interactions with biologically relevant molecules were experimentally studied using crossed electron-molecule beams experiment. The obtained results, were presented in four publications in international scientific journals. First study of deals with electron impact ionisation of furanose alcohols [see 1. in list of author publications on page 22]. It has been motivated by most important works in the field of electron induced damages of DNA bases [4]. Studied 3-hydroxytetrahydrofuran and tetrahydrofurfuryl alcohol, are important model molecules for more complex biological systems (e.g. deoxyribose).The influence of hydroxyl group on stabilisation of the positive ions of the molecules, together with the stability of furan ring in ionized form are main themes of the study. The studies of small amides and aminoacids are connected to scientific studies in the field of formation of the aminoacids and other biologically relevant molecules in space and works trying to explain electron induced processes in more complex molecules[12, 13, 24]. The most important results were obtained for aminoacid Serine [see 2. in list of author publications on page 22]. We have showed that additional OH group of Serine considerably lower the reaction enthalpy limit of reactions resulting to formation of neutral water molecules, in comparison to other amino acids. Also the study of (M-H)- reaction channel using the electron beam with FWHM under 100 meV is of high importance in the field. The last part of the thesis is focused on the electron interactions with organosilane compounds. Materials prepared from organosilane molecules in plasmas have wide range of applications in both biology and medicine. We have studied electron

Estimation and harvesting of human heat power for wearable electronic devices

International Nuclear Information System (INIS)

Dziurdzia, P; Brzozowski, I; Bratek, P; Gelmuda, W; Kos, A

2016-01-01

The paper deals with the issue of self-powered wearable electronic devices that are capable of harvesting free available energy dissipated by the user in the form of human heat. The free energy source is intended to be used as a secondary power source supporting primary battery in a sensor bracelet. The main scope of the article is a presentation of the concept for a measuring setup used to quantitative estimation of heat power sources in different locations over the human body area. The crucial role in the measurements of the human heat plays a thermoelectric module working in the open circuit mode. The results obtained during practical tests are confronted with the requirements of the dedicated thermoelectric generator. A prototype design of a human warmth energy harvester with an ultra-low power DC-DC converter based on the LTC3108 circuit is analysed

Virtual lesions of the IFG abolish response facilitation for biological and non-biological cues

Directory of Open Access Journals (Sweden)

Roger D Newman-Norlund

2010-03-01

Full Text Available Humans are faster to perform a given action following observation of that same action. Converging evidence suggests that the human mirror neuron system (MNS plays an important role in this phenomenon. However, the specificity of the neural mechanisms governing this effect remain controversial. Specialist theories of imitation suggest that biological cues are maximally capable of eliciting imitative facilitation. Generalist models, on the other hand, posit a broader role for the MNS in linking visual stimuli with appropriate responses. In the present study, we investigated the validity of these two theoretical approaches by disrupting the left and right inferior frontal gyrus (IFG during the preparation of congruent (imitative and incongruent (complementary actions cued by either biological (hand or non-biological (static dot stimuli. Delivery of TMS over IFG abolished imitative response facilitation. Critically, this effect was identical whether actions were cued by biological or non-biological stimuli. This finding argues against theories of imitation in which biological stimuli are treated preferentially and stresses the notion of the IFG as a vital center of general perception-action coupling in the human brain.

Biology and natural history of human papillomavirus infection

Directory of Open Access Journals (Sweden)

Fernandes JV

2013-01-01

Full Text Available José Veríssimo Fernandes,1 Josélio Maria Galvão de Araújo,1 Thales Allyrio Araújo de Medeiros Fernandes21Laboratory of Molecular Biology for Infectious Diseases and Cancer, Federal University of Rio Grande do Norte, Natal, Brazil; 2Department of Biomedical Sciences, University of Rio Grande do Norte State, Mossoró, BrazilAbstract: Human papillomavirus (HPV is one of the most common causes of sexually transmitted diseases worldwide. It has been proposed that the great majority of women and men have been infected with HPV at least once during their lifetime. HPV infection is associated with a variety of clinical conditions, ranging from benign lesions to cervical cancer. In most cases, the infection is transient, where most of the individuals are healing, eliminating the virus without the presence of any clinical manifestation. Actually, more than 120 HPV types have been cataloged, of which approximately 40 can infect the mucosa of the anogenital tract and are collectively known as mucosal HPV, which are classified based on their oncogenic potential as either low- or high-risk HPV types. The low-risk HPV type causes benign hyperproliferative lesions or genital warts, with a very limited tendency for malignant progression, while the high-risk HPV type is strongly associated with premalignant and malignant cervical lesions. The HPV cycle initiates when the virus gains access to undifferentiated cells of the basement membrane of the squamous columnar junction epithelium of the ectocervix, after these regions are exposed to mechanical or chemical trauma. The basal cells in the transformation zone retain the ability to differentiate, a property required for virion production. Cervical infection with high-risk HPV typically lasts from 12 to 18 months and in most cases is cleared spontaneously. However, in some women the immune response is insufficient to eliminate the virus, resulting in a persistent, long-term infection that may progress to a

Challenges regarding the start-up of an anaerobic biological sulphate reactor using H2 and CO2 as electron donor and carbon sources

CSIR Research Space (South Africa)

Roux, SP

2009-05-01

Full Text Available Include neutralization and chemical precipitation as well as membrane dependent processes. Biological sulphate reduction is another, environmentally benign option but relies heavily on the availability of an economically viable electron donor...

Comparison study of in vivo dose response to laser-driven versus conventional electron beam.

Science.gov (United States)

Oppelt, Melanie; Baumann, Michael; Bergmann, Ralf; Beyreuther, Elke; Brüchner, Kerstin; Hartmann, Josefin; Karsch, Leonhard; Krause, Mechthild; Laschinsky, Lydia; Leßmann, Elisabeth; Nicolai, Maria; Reuter, Maria; Richter, Christian; Sävert, Alexander; Schnell, Michael; Schürer, Michael; Woithe, Julia; Kaluza, Malte; Pawelke, Jörg

2015-05-01

The long-term goal to integrate laser-based particle accelerators into radiotherapy clinics not only requires technological development of high-intensity lasers and new techniques for beam detection and dose delivery, but also characterization of the biological consequences of this new particle beam quality, i.e. ultra-short, ultra-intense pulses. In the present work, we describe successful in vivo experiments with laser-driven electron pulses by utilization of a small tumour model on the mouse ear for the human squamous cell carcinoma model FaDu. The already established in vitro irradiation technology at the laser system JETI was further enhanced for 3D tumour irradiation in vivo in terms of beam transport, beam monitoring, dose delivery and dosimetry in order to precisely apply a prescribed dose to each tumour in full-scale radiobiological experiments. Tumour growth delay was determined after irradiation with doses of 3 and 6 Gy by laser-accelerated electrons. Reference irradiation was performed with continuous electron beams at a clinical linear accelerator in order to both validate the dedicated dosimetry employed for laser-accelerated JETI electrons and above all review the biological results. No significant difference in radiation-induced tumour growth delay was revealed for the two investigated electron beams. These data provide evidence that the ultra-high dose rate generated by laser acceleration does not impact the biological effectiveness of the particles.

Epidemiological and radio-biological studies in high background radiation areas of Kerala coast: implications in radiation protection science and human health

International Nuclear Information System (INIS)

Das, Birajalaxmi

2018-01-01

Till date, Linear No Threshold hypothesis (LNT) is well accepted in radiation protection science in spite of its limitations. However, dose response studies using multiple biological end points from high-background radiation areas have challenged the linearity. Radio-biological and epidemiological studies from high level natural radiation areas of Kerala coast showed non-linearity as well as efficient repair of DNA damage in HLNRA indicating that dose limits for public exposure needs to be revisited which may have implications in radiation protection science, human health and low dose radiation biology. However, further studies using high throughput approach is required to identify chronic radiation signatures in human population exposed to elevated level of natural background radiation

Electronic Nose and Electronic Tongue

Science.gov (United States)

Bhattacharyya, Nabarun; Bandhopadhyay, Rajib

Human beings have five senses, namely, vision, hearing, touch, smell and taste. The sensors for vision, hearing and touch have been developed for several years. The need for sensors capable of mimicking the senses of smell and taste have been felt only recently in food industry, environmental monitoring and several industrial applications. In the ever-widening horizon of frontier research in the field of electronics and advanced computing, emergence of electronic nose (E-Nose) and electronic tongue (E-Tongue) have been drawing attention of scientists and technologists for more than a decade. By intelligent integration of multitudes of technologies like chemometrics, microelectronics and advanced soft computing, human olfaction has been successfully mimicked by such new techniques called machine olfaction (Pearce et al. 2002). But the very essence of such research and development efforts has centered on development of customized electronic nose and electronic tongue solutions specific to individual applications. In fact, research trends as of date clearly points to the fact that a machine olfaction system as versatile, universal and broadband as human nose and human tongue may not be feasible in the decades to come. But application specific solutions may definitely be demonstrated and commercialized by modulation in sensor design and fine-tuning the soft computing solutions. This chapter deals with theory, developments of E-Nose and E-Tongue technology and their applications. Also a succinct account of future trends of R&D efforts in this field with an objective of establishing co-relation between machine olfaction and human perception has been included.

Relations between Intuitive Biological Thinking and Biological Misconceptions in Biology Majors and Nonmajors

Science.gov (United States)

Coley, John D.; Tanner, Kimberly

2015-01-01

Research and theory development in cognitive psychology and science education research remain largely isolated. Biology education researchers have documented persistent scientifically inaccurate ideas, often termed misconceptions, among biology students across biological domains. In parallel, cognitive and developmental psychologists have described intuitive conceptual systems—teleological, essentialist, and anthropocentric thinking—that humans use to reason about biology. We hypothesize that seemingly unrelated biological misconceptions may have common origins in these intuitive ways of knowing, termed cognitive construals. We presented 137 undergraduate biology majors and nonmajors with six biological misconceptions. They indicated their agreement with each statement, and explained their rationale for their response. Results indicate frequent agreement with misconceptions, and frequent use of construal-based reasoning among both biology majors and nonmajors in their written explanations. Moreover, results also show associations between specific construals and the misconceptions hypothesized to arise from those construals. Strikingly, such associations were stronger among biology majors than nonmajors. These results demonstrate important linkages between intuitive ways of thinking and misconceptions in discipline-based reasoning, and raise questions about the origins, persistence, and generality of relations between intuitive reasoning and biological misconceptions. PMID:25713093

Nutrition and the biology of human ageing: Proceedings of the ninth nestle international nutrition symposium

Science.gov (United States)

This 9th Nestle Nutrition Symposium on “Nutrition and the Biology of Human Ageing” is presented at a time of unprecedented demographic change worldwide. The UN population division forecasts that the number of people living over age 65 will rise to almost 1 billion (12% percent of the world’s populat...

The reactivity of plant, murine and human genome to electron beam irradiation

International Nuclear Information System (INIS)

Gavrila, L.; Usurelu, D.; Radu, I.; Timus, D.

2005-01-01

A broad spectrum of chromosomal rearrangements is described in plants (Allium cepa), mouse (Mus musculus domestics) and in humans (Homo sapiens sapiens), following in vivo and in vitro beta irradiation. Irradiations were performed at EAL, using a 2.998 GHz traveling-wave electron accelerator. The primary effect of electron beam irradiation is chromosomal breakage followed up by a variety of chromosomal rearrangements i.e. chromosomal aberrations represented mainly by chromatid gaps, deletions, ring chromosomes, dicentrics, translocations, complex chromosomal interchanges, acentric fragments and double minutes (DM). The clastogenic effects were associated in some instances with cell sterilization (i.e. cell death)

Comparative investigation on electron spin resonance dosimetry of tooth enamel of cow and human

International Nuclear Information System (INIS)

Jiao Ling; Zhang Wenyi; Ding Yanqiu; Kou Mingying

2010-01-01

The enamel samples from cow teeth and human teeth were irradiated with 137 Cs γ ray. Their electron spin resonance (ESR) spectra pre and post-irradiation were weaker than those of human. Mass of each sample is 100 mg, the dosimetric signal intensity of cow enamel increased with the radiation dose; the averaged radiation response of cow samples was (34.4±2.0) Gy -1 , very close to the average response of human tooth samples (36.3±2.9) Gy -1 . Therefore cow teeth can be used for retrospective radiation dosimetry when human teeth are unavailable. (authors)

Design of a biologically inspired lower limb exoskeleton for human gait rehabilitation.

Science.gov (United States)

Lyu, Mingxing; Chen, Weihai; Ding, Xilun; Wang, Jianhua; Bai, Shaoping; Ren, Huichao

2016-10-01

This paper proposes a novel bionic model of the human leg according to the theory of physiology. Based on this model, we present a biologically inspired 3-degree of freedom (DOF) lower limb exoskeleton for human gait rehabilitation, showing that the lower limb exoskeleton is fully compatible with the human knee joint. The exoskeleton has a hybrid serial-parallel kinematic structure consisting of a 1-DOF hip joint module and a 2-DOF knee joint module in the sagittal plane. A planar 2-DOF parallel mechanism is introduced in the design to fully accommodate the motion of the human knee joint, which features not only rotation but also relative sliding. Therefore, the design is consistent with the requirements of bionics. The forward and inverse kinematic analysis is studied and the workspace of the exoskeleton is analyzed. The structural parameters are optimized to obtain a larger workspace. The results using MATLAB-ADAMS co-simulation are shown in this paper to demonstrate the feasibility of our design. A prototype of the exoskeleton is also developed and an experiment performed to verify the kinematic analysis. Compared with existing lower limb exoskeletons, the designed mechanism has a large workspace, while allowing knee joint rotation and small amount of sliding.

Design of a biologically inspired lower limb exoskeleton for human gait rehabilitation

Science.gov (United States)

Lyu, Mingxing; Chen, Weihai; Ding, Xilun; Wang, Jianhua; Bai, Shaoping; Ren, Huichao

2016-10-01

This paper proposes a novel bionic model of the human leg according to the theory of physiology. Based on this model, we present a biologically inspired 3-degree of freedom (DOF) lower limb exoskeleton for human gait rehabilitation, showing that the lower limb exoskeleton is fully compatible with the human knee joint. The exoskeleton has a hybrid serial-parallel kinematic structure consisting of a 1-DOF hip joint module and a 2-DOF knee joint module in the sagittal plane. A planar 2-DOF parallel mechanism is introduced in the design to fully accommodate the motion of the human knee joint, which features not only rotation but also relative sliding. Therefore, the design is consistent with the requirements of bionics. The forward and inverse kinematic analysis is studied and the workspace of the exoskeleton is analyzed. The structural parameters are optimized to obtain a larger workspace. The results using MATLAB-ADAMS co-simulation are shown in this paper to demonstrate the feasibility of our design. A prototype of the exoskeleton is also developed and an experiment performed to verify the kinematic analysis. Compared with existing lower limb exoskeletons, the designed mechanism has a large workspace, while allowing knee joint rotation and small amount of sliding.

Understanding the limits of animal models as predictors of human biology: lessons learned from the sbv IMPROVER Species Translation Challenge.

Science.gov (United States)

Rhrissorrakrai, Kahn; Belcastro, Vincenzo; Bilal, Erhan; Norel, Raquel; Poussin, Carine; Mathis, Carole; Dulize, Rémi H J; Ivanov, Nikolai V; Alexopoulos, Leonidas; Rice, J Jeremy; Peitsch, Manuel C; Stolovitzky, Gustavo; Meyer, Pablo; Hoeng, Julia

2015-02-15

Inferring how humans respond to external cues such as drugs, chemicals, viruses or hormones is an essential question in biomedicine. Very often, however, this question cannot be addressed because it is not possible to perform experiments in humans. A reasonable alternative consists of generating responses in animal models and 'translating' those results to humans. The limitations of such translation, however, are far from clear, and systematic assessments of its actual potential are urgently needed. sbv IMPROVER (systems biology verification for Industrial Methodology for PROcess VErification in Research) was designed as a series of challenges to address translatability between humans and rodents. This collaborative crowd-sourcing initiative invited scientists from around the world to apply their own computational methodologies on a multilayer systems biology dataset composed of phosphoproteomics, transcriptomics and cytokine data derived from normal human and rat bronchial epithelial cells exposed in parallel to 52 different stimuli under identical conditions. Our aim was to understand the limits of species-to-species translatability at different levels of biological organization: signaling, transcriptional and release of secreted factors (such as cytokines). Participating teams submitted 49 different solutions across the sub-challenges, two-thirds of which were statistically significantly better than random. Additionally, similar computational methods were found to range widely in their performance within the same challenge, and no single method emerged as a clear winner across all sub-challenges. Finally, computational methods were able to effectively translate some specific stimuli and biological processes in the lung epithelial system, such as DNA synthesis, cytoskeleton and extracellular matrix, translation, immune/inflammation and growth factor/proliferation pathways, better than the expected response similarity between species. pmeyerr@us.ibm.com or Julia

Production of biologically active recombinant human factor H in Physcomitrella.

Science.gov (United States)

Büttner-Mainik, Annette; Parsons, Juliana; Jérôme, Hanna; Hartmann, Andrea; Lamer, Stephanie; Schaaf, Andreas; Schlosser, Andreas; Zipfel, Peter F; Reski, Ralf; Decker, Eva L

2011-04-01

The human complement regulatory serum protein factor H (FH) is a promising future biopharmaceutical. Defects in the gene encoding FH are associated with human diseases like severe kidney and retinal disorders in the form of atypical haemolytic uremic syndrome (aHUS), membranoproliferative glomerulonephritis II (MPGN II) or age-related macular degeneration (AMD). There is a current need to apply intact full-length FH for the therapy of patients with congenital or acquired defects of this protein. Application of purified or recombinant FH (rFH) to these patients is an important and promising approach for the treatment of these diseases. However, neither protein purified from plasma of healthy individuals nor recombinant protein is currently available on the market. Here, we report the first stable expression of the full-length human FH cDNA and the subsequent production of this glycoprotein in a plant system. The moss Physcomitrella patens perfectly suits the requirements for the production of complex biopharmaceuticals as this eukaryotic system not only offers an outstanding genetical accessibility, but moreover, proteins can be produced safely in scalable photobioreactors without the need for animal-derived medium compounds. Transgenic moss lines were created, which express the human FH cDNA and target the recombinant protein to the culture supernatant via a moss-derived secretion signal. Correct processing of the signal peptide and integrity of the moss-produced rFH were verified via peptide mapping by mass spectrometry. Ultimately, we show that the rFH displays complement regulatory activity comparable to FH purified from plasma. © 2010 The Authors. Plant Biotechnology Journal © 2010 Society for Experimental Biology, Association of Applied Biologists and Blackwell Publishing Ltd.

Effects of Thermal Resistance on One-Dimensional Thermal Analysis of the Epidermal Flexible Electronic Devices Integrated with Human Skin

Science.gov (United States)

Li, He; Cui, Yun

2017-12-01

Nowadays, flexible electronic devices are increasingly used in direct contact with human skin to monitor the real-time health of human body. Based on the Fourier heat conduction equation and Pennes bio-heat transfer equation, this paper deduces the analytical solutions of one - dimensional heat transfer for flexible electronic devices integrated with human skin under the condition of a constant power. The influence of contact thermal resistance between devices and skin is considered as well. The corresponding finite element model is established to verify the correctness of analytical solutions. The results show that the finite element analysis agrees well with the analytical solution. With bigger thermal resistance, temperature increase of skin surface will decrease. This result can provide guidance for the design of flexible electronic devices to reduce the negative impact that exceeding temperature leave on human skin.

Molecular biology in a distributed world. A Kantian perspective on scientific practices and the human mind

Directory of Open Access Journals (Sweden)

Mariagrazia Portera

2016-01-01

Full Text Available In recent years the number of scholarly publications devoted to Kant's theory of biology has rapidly growing, with particular attention being given to Kant's thoughts about the concepts of teleology, function, organism, and their respective roles in scientific practice. Moving from these recent studies, and distancing itself from their mostly evolutionary background, the main aim of the present paper is to suggest an original "cognitive turn" in the interpretation of Kant's theory of biology. More specifically, the Authors will trace a connection between some Kantian theses about the “peculiar” or special nature of the human mind (intellectus ectypus, advanced in the Critique of the Power of Judgement (§ 76, 77, and some specific epistemological issues pertaining to the research practice of contemporary molecular biology.

Quantum effects in biological electron transfer

Czech Academy of Sciences Publication Activity Database

de la Lande, A.; Babcock, N. S.; Řezáč, Jan; Levy, B.; Sanders, B. C.; Salahub, D.

2012-01-01

Roč. 14, č. 17 (2012), s. 5902-5918 ISSN 1463-9076 Institutional research plan: CEZ:AV0Z40550506 Keywords : electron transfer * tunnelling * decoherence * semi-classical molecular dynamics * density functional theory Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.829, year: 2012

Synthetic Biology Approaches to Engineer Probiotics and Members of the Human Microbiota for Biomedical Applications.

Science.gov (United States)

Bober, Josef R; Beisel, Chase L; Nair, Nikhil U

2018-03-12

An increasing number of studies have strongly correlated the composition of the human microbiota with many human health conditions and, in several cases, have shown that manipulating the microbiota directly affects health. These insights have generated significant interest in engineering indigenous microbiota community members and nonresident probiotic bacteria as biotic diagnostics and therapeutics that can probe and improve human health. In this review, we discuss recent advances in synthetic biology to engineer commensal and probiotic lactic acid bacteria, bifidobacteria, and Bacteroides for these purposes, and we provide our perspective on the future potential of these technologies. 277 Expected final online publication date for the Annual Review of Biomedical Engineering Volume 20 is June 4, 2018. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Studies of the electronic structure and biological activity of chosen 1,4-benzodiazepines by {sup 35}Cl NQR spectroscopy and DFT calculations

Energy Technology Data Exchange (ETDEWEB)

Bronisz, K. [Department of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznan (Poland); Ostafin, M. [Department of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznan (Poland)], E-mail: ostifnqr@amu.edu.pl; Poleshchuk, O. Kh. [Department of Chemistry, Tomsk Pedagogical University, Komsomolskii 75, 634041 Tomsk (Russian Federation); Mielcarek, J. [Faculty of Pharmacy, University of Medical Sciences, Grunwaldzka 6, 60-780 Poznan (Poland); Nogaj, B. [Department of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznan (Poland)

2006-11-08

Selected derivatives of 1,4-benzodiazepine: lorazepam, lormetazepam, oxazepam and temazepam, used as active substances in anxiolytic drugs, have been studied by {sup 35}Cl NQR method in order to find the correlation between electronic structure and biological activity. The {sup 35}Cl NQR resonance frequencies ({nu} {sub Q}) measured at 77 K have been correlated with the following parameters characterising their biological activity: biological half-life period (t {sub 0.5}), affinity to benzodiazepine receptor (IC{sub 50}) and mean dose equivalent. The results of experimental study of some benzodiazepine derivatives by nuclear quadrupole resonance of {sup 35}Cl nuclei are compared with theoretical results based on DFT calculations which were carried out by means of Gaussian'98 W software.

Humans in Space: Summarizing the Medico-Biological Results of the Space Shuttle Program

Science.gov (United States)

Risin, Diana; Stepaniak, P. C.; Grounds, D. J.

2011-01-01

As we celebrate the 50th anniversary of Gagarin's flight that opened the era of Humans in Space we also commemorate the 30th anniversary of the Space Shuttle Program (SSP) which was triumphantly completed by the flight of STS-135 on July 21, 2011. These were great milestones in the history of Human Space Exploration. Many important questions regarding the ability of humans to adapt and function in space were answered for the past 50 years and many lessons have been learned. Significant contribution to answering these questions was made by the SSP. To ensure the availability of the Shuttle Program experiences to the international space community NASA has made a decision to summarize the medico-biological results of the SSP in a fundamental edition that is scheduled to be completed by the end of 2011 beginning 2012. The goal of this edition is to define the normal responses of the major physiological systems to short-duration space flights and provide a comprehensive source of information for planning, ensuring successful operational activities and for management of potential medical problems that might arise during future long-term space missions. The book includes the following sections: 1. History of Shuttle Biomedical Research and Operations; 2. Medical Operations Overview Systems, Monitoring, and Care; 3. Biomedical Research Overview; 4. System-specific Adaptations/Responses, Issues, and Countermeasures; 5. Multisystem Issues and Countermeasures. In addition, selected operational documents will be presented in the appendices. The chapters are written by well-recognized experts in appropriate fields, peer reviewed, and edited by physicians and scientists with extensive expertise in space medical operations and space-related biomedical research. As Space Exploration continues the major question whether humans are capable of adapting to long term presence and adequate functioning in space habitats remains to be answered We expect that the comprehensive review of

Quantum Biology

Directory of Open Access Journals (Sweden)

Alessandro Sergi

2009-06-01

Full Text Available A critical assessment of the recent developmentsof molecular biology is presented.The thesis that they do not lead to a conceptualunderstanding of life and biological systems is defended.Maturana and Varela's concept of autopoiesis is briefly sketchedand its logical circularity avoided by postulatingthe existence of underlying living processes,entailing amplification from the microscopic to the macroscopic scale,with increasing complexity in the passage from one scale to the other.Following such a line of thought, the currently accepted model of condensed matter, which is based on electrostatics and short-ranged forces,is criticized. It is suggested that the correct interpretationof quantum dispersion forces (van der Waals, hydrogen bonding, and so onas quantum coherence effects hints at the necessity of includinglong-ranged forces (or mechanisms for them incondensed matter theories of biological processes.Some quantum effects in biology are reviewedand quantum mechanics is acknowledged as conceptually important to biology since withoutit most (if not all of the biological structuresand signalling processes would not even exist. Moreover, it is suggested that long-rangequantum coherent dynamics, including electron polarization,may be invoked to explain signal amplificationprocess in biological systems in general.

Biological effects of transuranic elements in the environment: human effects and risk estimates

International Nuclear Information System (INIS)

Thompson, R.C.; Wachholz, B.W.

1980-01-01

The potential for human effects from environmentally dispersed transuranic elements is briefly reviewed. Inhalation of transuranics suspended in air and ingestion of transuranics deposited on or incorporated in foodstuffs are the significant routes of entry. Inhalation is probably the more important of these routes because gastrointestinal absorption of ingested transuranics is so inefficient. Major uncertainties are those concerned with substantially enhanced absorption by the very young and the possibility of increased availability as transuranics become incorporated in biological food chains

The biological response of plucked human hair to low-dose radiation: a measure of individual radiosensitivity and a technique for biological dosimetry

International Nuclear Information System (INIS)

Swain, D.

1997-01-01

It is often assumed that the effects of radiation are linear with dose and that high dose effects can be extrapolated to low dose levels. However, there are a variety of mechanisms which can alter the response at low doses. The most important of these relate to induced sensitivity or induced repair mechanisms. It is therefore important that this area is studied in more depth by looking at the molecular effects and damage to cells at low doses. It is well known that there are certain rare genetic syndromes which predispose individuals to cancer, e.g. ataxia telangiectasia. It is also probable that there is a large range of sensitivity in the natural variation of individuals to the risk of radiation-induced cancer. It is proposed that radiosensitivity is studied using stimulated lymphocytes from whole blood and the technique extended to look at the effects in cell cultures established from human hair. Radiation treatment of cell cultures established from plucked human hair has been previously advocated as a non-invasive technique for non-uniform biological dosimetry and it is proposed that these techniques are adapted to the use of hair to estimate individual radiosensitivity. The aim is to establish and optimize these techniques for culturing keratinocytes from plucked human hair follicles with a view to study biological markers for the subsequent assessment of radiosensitivity. Preliminary results are promising and suggest that the technique for culturing keratinocytes from hair presents a feasible approach. Results from this primary cell culture technique and results from the comparison of the micronuclei data obtained from the cell cultures and stimulated lymphocytes will be presented. (author)

Integration of Principles of Systems Biology and Radiation Biology: Toward Development of in silico Models to Optimize IUdR-Mediated Radiosensitization of DNA Mismatch Repair Deficient (Damage Tolerant) Human Cancers

International Nuclear Information System (INIS)

Kinsella, Timothy J.; Gurkan-Cavusoglu, Evren; Du, Weinan; Loparo, Kenneth A.

2011-01-01

Over the last 7 years, we have focused our experimental and computational research efforts on improving our understanding of the biochemical, molecular, and cellular processing of iododeoxyuridine (IUdR) and ionizing radiation (IR) induced DNA base damage by DNA mismatch repair (MMR). These coordinated research efforts, sponsored by the National Cancer Institute Integrative Cancer Biology Program (ICBP), brought together system scientists with expertise in engineering, mathematics, and complex systems theory and translational cancer researchers with expertise in radiation biology. Our overall goal was to begin to develop computational models of IUdR- and/or IR-induced base damage processing by MMR that may provide new clinical strategies to optimize IUdR-mediated radiosensitization in MMR deficient (MMR − ) “damage tolerant” human cancers. Using multiple scales of experimental testing, ranging from purified protein systems to in vitro (cellular) and to in vivo (human tumor xenografts in athymic mice) models, we have begun to integrate and interpolate these experimental data with hybrid stochastic biochemical models of MMR damage processing and probabilistic cell cycle regulation models through a systems biology approach. In this article, we highlight the results and current status of our integration of radiation biology approaches and computational modeling to enhance IUdR-mediated radiosensitization in MMR − damage tolerant cancers.

Tiptoeing to chromosome tips: facts, promises and perils of today's human telomere biology.

Science.gov (United States)

Fajkus, J; Simícková, M; Maláska, J

2002-04-29

The past decade has witnessed an explosion of knowledge concerning the structure and function of chromosome terminal structures-telomeres. Today's telomere research has advanced from a pure descriptive approach of DNA and protein components to an elementary understanding of telomere metabolism, and now to promising applications in medicine. These applications include 'passive' ones, among which the use of analysis of telomeres and telomerase (a cellular reverse transcriptase that synthesizes telomeres) for cancer diagnostics is the best known. The 'active' applications involve targeted downregulation or upregulation of telomere synthesis, either to mortalize immortal cancer cells, or to rejuvenate mortal somatic cells and tissues for cellular transplantations, respectively. This article reviews the basic data on structure and function of human telomeres and telomerase, as well as both passive and active applications of human telomere biology.

Synthetic biology as red herring.

Science.gov (United States)

Preston, Beth

2013-12-01

It has become commonplace to say that with the advent of technologies like synthetic biology the line between artifacts and living organisms, policed by metaphysicians since antiquity, is beginning to blur. But that line began to blur 10,000 years ago when plants and animals were first domesticated; and has been thoroughly blurred at least since agriculture became the dominant human subsistence pattern many millennia ago. Synthetic biology is ultimately only a late and unexceptional offshoot of this prehistoric development. From this perspective, then, synthetic biology is a red herring, distracting us from more thorough philosophical consideration of the most truly revolutionary human practice-agriculture. In the first section of this paper I will make this case with regard to ontology, arguing that synthetic biology crosses no ontological lines that were not crossed already in the Neolithic. In the second section I will construct a parallel case with regard to cognition, arguing that synthetic biology as biological engineering represents no cognitive advance over what was required for domestication and the new agricultural subsistence pattern it grounds. In the final section I will make the case with regard to human existence, arguing that synthetic biology, even if wildly successful, is not in a position to cause significant existential change in what it is to be human over and above the massive existential change caused by the transition to agriculture. I conclude that a longer historical perspective casts new light on some important issues in philosophy of technology and environmental philosophy. Copyright © 2013 Elsevier Ltd. All rights reserved.

Natural killer cell biology illuminated by primary immunodeficiency syndromes in humans.

Science.gov (United States)

Voss, Matthias; Bryceson, Yenan T

2017-04-01

Natural killer (NK) cells are innate immune cytotoxic effector cells well known for their role in antiviral immunity and tumor immunosurveillance. In parts, this knowledge stems from rare inherited immunodeficiency disorders in humans that abrogate NK cell function leading to immune impairments, most notably associated with a high susceptibility to viral infections. Phenotypically, these disorders range from deficiencies selectively affecting NK cells to complex general immune defects that affect NK cells but also other immune cell subsets. Moreover, deficiencies may be associated with reduced NK cell numbers or rather impair specific NK cell effector functions. In recent years, genetic defects underlying the various NK cell deficiencies have been uncovered and have triggered investigative efforts to decipher the molecular mechanisms underlying these disorders. Here we review the associations between inherited human diseases and NK cell development as well as function, with a particular focus on defects in NK cell exocytosis and cytotoxicity. Furthermore we outline how reports of diverse genetic defects have shaped our understanding of NK cell biology. Copyright © 2015. Published by Elsevier Inc.

Human METTL20 methylates lysine residues adjacent to the recognition loop of the electron transfer flavoprotein in mitochondria.

Science.gov (United States)

Rhein, Virginie F; Carroll, Joe; He, Jiuya; Ding, Shujing; Fearnley, Ian M; Walker, John E

2014-08-29

In mammalian mitochondria, protein methylation is a relatively uncommon post-transcriptional modification, and the extent of the mitochondrial protein methylome, the modifying methyltransferases, and their substrates have been little studied. As shown here, the β-subunit of the electron transfer flavoprotein (ETF) is one such methylated protein. The ETF is a heterodimer of α- and β-subunits. Lysine residues 199 and 202 of mature ETFβ are almost completely trimethylated in bovine heart mitochondria, whereas ETFα is not methylated. The enzyme responsible for the modifications was identified as methyltransferase-like protein 20 (METTL20). In human 143B cells, the methylation of ETFβ is less extensive and is diminished further by suppression of METTL20. Tagged METTL20 expressed in HEK293T cells specifically associates with the ETF and promotes the trimethylation of ETFβ lysine residues 199 and 202. ETF serves as a mobile electron carrier linking dehydrogenases involved in fatty acid oxidation and one-carbon metabolism to the membrane-associated ubiquinone pool. The methylated residues in ETFβ are immediately adjacent to a protein loop that recognizes and binds to the dehydrogenases. Suppression of trimethylation of ETFβ in mouse C2C12 cells oxidizing palmitate as an energy source reduced the consumption of oxygen by the cells. These experiments suggest that the oxidation of fatty acids in mitochondria and the passage of electrons via the ETF may be controlled by modulating the protein-protein interactions between the reduced dehydrogenases and the β-subunit of the ETF by trimethylation of lysine residues. METTL20 is the first lysine methyltransferase to be found to be associated with mitochondria. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

Materials and optimized designs for human-machine interfaces via epidermal electronics.

Science.gov (United States)

Jeong, Jae-Woong; Yeo, Woon-Hong; Akhtar, Aadeel; Norton, James J S; Kwack, Young-Jin; Li, Shuo; Jung, Sung-Young; Su, Yewang; Lee, Woosik; Xia, Jing; Cheng, Huanyu; Huang, Yonggang; Choi, Woon-Seop; Bretl, Timothy; Rogers, John A

2013-12-17

Thin, soft, and elastic electronics with physical properties well matched to the epidermis can be conformally and robustly integrated with the skin. Materials and optimized designs for such devices are presented for surface electromyography (sEMG). The findings enable sEMG from wide ranging areas of the body. The measurements have quality sufficient for advanced forms of human-machine interface. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Molecular biology of Homo sapiens: Abstracts of papers presented at the 51st Cold Spring Harbor symposium on quantitative biology

International Nuclear Information System (INIS)

Watson, J.D.; Siniscalco, M.

1986-01-01

This volume contains abstracts of papers presented at the 51st Cold Springs Harbor Symposium on Quantitative Biology. The topic for this meeting was the ''Molecular Biology of Homo sapiens.'' Sessions were entitled Human Gene Map, Human Cancer Genes, Genetic Diagnosis, Human Evolution, Drugs Made Off Human Genes, Receptors, and Gene Therapy. (DT)

Holography and coherent diffraction with low-energy electrons: A route towards structural biology at the single molecule level.

Science.gov (United States)

Latychevskaia, Tatiana; Longchamp, Jean-Nicolas; Escher, Conrad; Fink, Hans-Werner

2015-12-01

The current state of the art in structural biology is led by NMR, X-ray crystallography and TEM investigations. These powerful tools however all rely on averaging over a large ensemble of molecules. Here, we present an alternative concept aiming at structural analysis at the single molecule level. We show that by combining electron holography and coherent diffraction imaging estimations concerning the phase of the scattered wave become needless as the phase information is extracted from the data directly and unambiguously. Performed with low-energy electrons the resolution of this lens-less microscope is just limited by the De Broglie wavelength of the electron wave and the numerical aperture, given by detector geometry. In imaging freestanding graphene, a resolution of 2Å has been achieved revealing the 660.000 unit cells of the graphene sheet from a single data set. Once applied to individual biomolecules the method shall ultimately allow for non-destructive imaging and imports the potential to distinguish between different conformations of proteins with atomic resolution. Copyright © 2015. Published by Elsevier B.V.

Advances in imaging and electron physics time resolved electron diffraction for chemistry, biology and material science

CERN Document Server

Hawkes, Peter W

2014-01-01

Advances in Imaging & Electron Physics merges two long-running serials-Advances in Electronics & Electron Physics and Advances in Optical & Electron Microscopy. The series features extended articles on the physics of electron devices (especially semiconductor devices), particle optics at high and low energies, microlithography, image science and digital image processing, electromagnetic wave propagation, electron microscopy, and the computing methods used in all these domains. Contributions from leading authorities Informs and updates on all the latest developments in the field.

The DNA sequence and biology of human chromosome 19

Energy Technology Data Exchange (ETDEWEB)

Grimwood, J; Gordon, L A; Olsen, A; Terry, A; Schmutz, J; Lamerdin, J; Hellsten, U; Goodstein, D; Couronne, O; Tran-Gyamfi, M

2004-04-06

Chromosome 19 has the highest gene density of all human chromosomes, more than double the genome-wide average. The large clustered gene families, corresponding high GC content, CpG islands and density of repetitive DNA indicate a chromosome rich in biological and evolutionary significance. Here we describe 55.8 million base pairs of highly accurate finished sequence representing 99.9% of the euchromatin portion of the chromosome. Manual curation of gene loci reveals 1,461 protein-coding genes and 321 pseudogenes. Among these are genes directly implicated in Mendelian disorders, including familial hypercholesterolemia and insulin-resistant diabetes. Nearly one quarter of these genes belong to tandemly arranged families, encompassing more than 25% of the chromosome. Comparative analyses show a fascinating picture of conservation and divergence, revealing large blocks of gene orthology with rodents, scattered regions with more recent gene family expansions and deletions, and segments of coding and non-coding conservation with the distant fish species Takifugu.

Using a Redox Modality to Connect Synthetic Biology to Electronics: Hydrogel-Based Chemo-Electro Signal Transduction for Molecular Communication.

Science.gov (United States)

Liu, Yi; Tsao, Chen-Yu; Kim, Eunkyoung; Tschirhart, Tanya; Terrell, Jessica L; Bentley, William E; Payne, Gregory F

2017-01-01

A hydrogel-based dual film coating is electrofabricated for transducing bio-relevant chemical information into electronical output. The outer film has a synthetic biology construct that recognizes an external molecular signal and transduces this input into the expression of an enzyme that converts redox-inactive substrate into a redox-active intermediate, which is detected through an amplification mechanism of the inner redox-capacitor film. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A New Approach to Studying Biological and Soft Materials Using Focused Ion Beam Scanning Electron Microscopy (FIB SEM)

International Nuclear Information System (INIS)

Stokes, D J; Morrissey, F; Lich, B H

2006-01-01

Over the last decade techniques such as confocal light microscopy, in combination with fluorescent labelling, have helped biologists and life scientists to study biological architectures at tissue and cell level in great detail. Meanwhile, obtaining information at very small length scales is possible with the combination of sample preparation techniques and transmission electron microscopy (TEM) or scanning transmission electron microscopy (STEM). Scanning electron microscopy (SEM) is well known for the determination of surface characteristics and morphology. However, the desire to understand the three dimensional relationships of meso-scale hierarchies has led to the development of advanced microscopy techniques, to give a further complementary approach. A focused ion beam (FIB) can be used as a nano-scalpel and hence allows us to reveal internal microstructure in a site-specific manner. Whilst FIB instruments have been used to study and verify the three-dimensional architecture of man made materials, SEM and FIB technologies have now been brought together in a single instrument representing a powerful combination for the study of biological specimens and soft materials. We demonstrate the use of FIB SEM to study three-dimensional relationships for a range of length scales and materials, from small-scale cellular structures to the larger scale interactions between biomedical materials and tissues. FIB cutting of heterogeneous mixtures of hard and soft materials, resulting in a uniform cross-section, has proved to be of particular value since classical preparation methods tend to introduce artefacts. Furthermore, by appropriate selection, we can sequentially cross-section to create a series of 'slices' at specific intervals. 3D reconstruction software can then be used to volume-render information from the 2D slices, enabling us to immediately see the spatial relationships between microstructural components

Review of the biological effects of weightlessness on the human endocrine system

Science.gov (United States)

Hughes-Fulford, M.

1993-01-01

Studies from space flights over the past two decades have demonstrated that there are basic physiological changes in humans during space flight. These changes include cephalad fluid shifts, loss of fluid and electrolytes, loss of muscle mass, space motion sickness, anemia, reduced immune response, and loss of calcium and mineralized bone. The cause of most of these manifestations is not known but the general approach has been to investigate systemic and hormonal changes. However, data from the 1973-1974 Skylabs, Spacelab 3 (SL-3), Spacelab D-I (SL-DI), and now the new SLS-1 missions support a more basic biological response to microgravity that may occur at the tissue, cellular, and molecular level. This report summarizes ground-based and SLS-1 experiments that examined the mechanism of loss of red blood cell mass in humans, the loss of bone mass and lowered osteoblast growth under space flight conditions, and loss of immune function in microgravity.

Aberrant Free Radical Biology Is a Unifying Theme in the Etiology and Pathogenesis of Major Human Diseases

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Frederick E. Domann

2013-04-01

Full Text Available The seemingly disparate areas of oxygen toxicity, radiation exposure, and aging are now recognized to share a common feature—the aberrant production and/or removal of biologically derived free radicals and other reactive oxygen and nitrogen species (ROS/RNS. Advances in our understanding of the effects of free radicals in biology and medicine have been, and continue to be, actively translated into clinically tractable diagnostic and therapeutic applications. This issue is dedicated to recent advances, both basic discoveries and clinical applications, in the field of free radicals in biology and medicine. As more is understood about the proximal biological targets of aberrantly produced or removed reactive species, their sensors, and effectors of compensatory response, a great deal more will be learned about the commonalities in mechanisms underlying seemingly disparate disease states. Together with this deeper understanding, opportunities will arise to devise rational therapeutic interventions to decrease the incidence and severity of these diseases and positively impact the human healthspan.

Molecular biology of Homo sapiens: Abstracts of papers presented at the 51st Cold Spring Harbor symposium on quantitative biology

Energy Technology Data Exchange (ETDEWEB)

Watson, J.D.; Siniscalco, M.

1986-01-01

This volume contains abstracts of papers presented at the 51st Cold Springs Harbor Symposium on Quantitative Biology. The topic for this meeting was the ''Molecular Biology of Homo sapiens.'' Sessions were entitled Human Gene Map, Human Cancer Genes, Genetic Diagnosis, Human Evolution, Drugs Made Off Human Genes, Receptors, and Gene Therapy. (DT)

Enhanced Physicochemical and Biological Properties of Ion-Implanted Titanium Using Electron Cyclotron Resonance Ion Sources

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Csaba Hegedűs

2016-01-01

Full Text Available The surface properties of metallic implants play an important role in their clinical success. Improving upon the inherent shortcomings of Ti implants, such as poor bioactivity, is imperative for achieving clinical use. In this study, we have developed a Ti implant modified with Ca or dual Ca + Si ions on the surface using an electron cyclotron resonance ion source (ECRIS. The physicochemical and biological properties of ion-implanted Ti surfaces were analyzed using various analytical techniques, such as surface analyses, potentiodynamic polarization and cell culture. Experimental results indicated that a rough morphology was observed on the Ti substrate surface modified by ECRIS plasma ions. The in vitro electrochemical measurement results also indicated that the Ca + Si ion-implanted surface had a more beneficial and desired behavior than the pristine Ti substrate. Compared to the pristine Ti substrate, all ion-implanted samples had a lower hemolysis ratio. MG63 cells cultured on the high Ca and dual Ca + Si ion-implanted surfaces revealed significantly greater cell viability in comparison to the pristine Ti substrate. In conclusion, surface modification by electron cyclotron resonance Ca and Si ion sources could be an effective method for Ti implants.

The Use of Ethical Frameworks for Implementing Science as a Human Endeavour in Year 10 Biology

Science.gov (United States)

Yap, Siew Fong; Dawson, Vaille

2014-01-01

This research focuses on the use of ethical frameworks as a pedagogical model for socio-scientific education in implementing the "Science as a Human Endeavour" (SHE) strand of the Australian Curriculum: Science in a Year 10 biology class in a Christian college in metropolitan Perth, Western Australia. Using a case study approach, a mixed…

Excited states in biological systems

International Nuclear Information System (INIS)

Cilento, G.; Zinner, K.; Bechara, E.J.H.; Duran, N.; Baptista, R.C. de; Shimizu, Y.; Augusto, O.; Faljoni-Alario, A.; Vidigal, C.C.C.; Oliveira, O.M.M.F.; Haun, M.

1979-01-01

Some aspects of bioluminescence related to bioenergetics are discussed: 1. chemical generation of excited species, by means of two general processes: electron transference and cyclic - and linear peroxide cleavage; 2. biological systems capable of generating excited states and 3. biological functions of these states, specially the non-emissive ones (tripletes). The production and the role of non-emissive excited states in biological systems are analysed, the main purpose of the study being the search for non-emissive states. Experiences carried out in biological systems are described; results and conclusions are given. (M.A.) [pt

HNS{sup +} and HSN{sup +} cations: Electronic states, spin-rovibronic spectroscopy with planetary and biological implications

Energy Technology Data Exchange (ETDEWEB)

Trabelsi, Tarek; Hochlaf, Majdi, E-mail: hochlaf@univ-mlv.fr [Laboratoire Modélisation et Simulation Multi Echelle, Université Paris-Est, MSME UMR 8208 CNRS, 5 Blvd. Descartes, 77454 Marne-la-Vallée (France); Ben Yaghlane, Saida [Laboratoire de Spectroscopie Atomique, Moléculaire et Applications—LSAMA, Université de Tunis El Manar, Tunis (Tunisia); Al Mogren, Muneerah Mogren [Chemistry Department, Faculty of Science, King Saud University, P.O. Box 2455, Riyadh 11451 (Saudi Arabia); Francisco, Joseph S. [Department of Chemistry, University of Nebraska-Lincoln, 433 Hamilton Hall, Lincoln, Nebraska 68588-0304 (United States)

2016-08-28

Ab initio methods in conjunction with a large basis set are used to compute the potential energy surfaces of the 12 lowest electronic states of the HNS{sup +} and HSN{sup +} isomeric forms. These potentials are used in discussions of the metastability of these cations and plausible mechanisms for the H{sup +}/H + SN{sup +}/SN, S/S{sup +} + NH{sup +}/NH, N/N{sup +} + SH{sup +}/SH ion-molecule reactions. Interestingly, the low rovibrational levels of HSN{sup +}(1{sup 2}A″) and HNS{sup +}(1{sup 2}A″) electronically excited ions are predicted to be long-lived. Both ions are suggested to be a suitable candidate for light-sensitive NO{sup ⋅} donor in vivo and as a possible marker for the detection of intermediates in nitrites + H{sub 2}S reactions at the cellular level. The full spin rovibronic levels of HNS{sup +} are presented, which may assist in the experimental identification of HNS{sup +} and HSN{sup +} ions and in elucidating their roles in astrophysical and biological media.

Structural and Biological Assessment of Zinc Doped Hydroxyapatite Nanoparticles

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Cristina Liana Popa

2016-01-01

Full Text Available The aim of the current research work was to study the physicochemical and biological properties of synthesized zinc doped hydroxyapatite (ZnHAp nanoparticles with Zn concentrations xZn=0 (HAp, xZn=0.07 (7ZnHAp, and xZn=0.1 (10ZnHAp for potential use in biological applications. The morphology, size, compositions, and incorporation of zinc into hydroxyapatite were characterized by scanning electron microscopy (SEM, transmission electron microscopy (TEM, Fourier Transform Infrared Spectroscopy (FTIR, Raman scattering, and X-Ray Photoelectron Spectroscopy (XPS. In addition, the cytotoxicity of ZnHAp nanoparticles was tested on both E. coli bacteria and human hepatocarcinoma cell line HepG2. The results showed that ZnHAp nanoparticles (HAp, 7ZnHAp, and 10ZnHAp have slightly elongated morphologies with average diameters between 25 nm and 18 nm. On the other hand, a uniform and homogeneous distribution of the constituent elements (calcium, phosphorus, zinc, and oxygen in the ZnHAp powder was noticed. Besides, FTIR and Raman analyses confirmed the proper hydroxyapatite structure of the synthesized ZnHAp nanoparticles with the signature of phosphate, carbonate, and hydroxyl groups. Moreover, it can be concluded that Zn doping at the tested concentrations is not inducing a specific prokaryote or eukaryote toxicity in HAp compounds.

Relations between intuitive biological thinking and biological misconceptions in biology majors and nonmajors.

Science.gov (United States)

Coley, John D; Tanner, Kimberly

2015-03-02

Research and theory development in cognitive psychology and science education research remain largely isolated. Biology education researchers have documented persistent scientifically inaccurate ideas, often termed misconceptions, among biology students across biological domains. In parallel, cognitive and developmental psychologists have described intuitive conceptual systems--teleological, essentialist, and anthropocentric thinking--that humans use to reason about biology. We hypothesize that seemingly unrelated biological misconceptions may have common origins in these intuitive ways of knowing, termed cognitive construals. We presented 137 undergraduate biology majors and nonmajors with six biological misconceptions. They indicated their agreement with each statement, and explained their rationale for their response. Results indicate frequent agreement with misconceptions, and frequent use of construal-based reasoning among both biology majors and nonmajors in their written explanations. Moreover, results also show associations between specific construals and the misconceptions hypothesized to arise from those construals. Strikingly, such associations were stronger among biology majors than nonmajors. These results demonstrate important linkages between intuitive ways of thinking and misconceptions in discipline-based reasoning, and raise questions about the origins, persistence, and generality of relations between intuitive reasoning and biological misconceptions. © 2015 J. D. Coley and K. Tanner. CBE—Life Sciences Education © 2015 The American Society for Cell Biology. This article is distributed by The American Society for Cell Biology under license from the author(s). It is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

Biological fuel cells and their applications

OpenAIRE

Shukla, AK; Suresh, P; Berchmans, S; Rajendran, A

2004-01-01

One type of genuine fuel cell that does hold promise in the long-term is the biological fuel cell. Unlike conventional fuel cells, which employ hydrogen, ethanol and methanol as fuel, biological fuel cells use organic products produced by metabolic processes or use organic electron donors utilized in the growth processes as fuels for current generation. A distinctive feature of biological fuel cells is that the electrode reactions are controlled by biocatalysts, i.e. the biological redox-reac...

Advances in electronic-nose technologies for the detection of volatile biomarker metabolites in the human breath

Science.gov (United States)

Alphus D. Wilson

2015-01-01

Recent advancements in the use of electronic-nose (e-nose) devices to analyze human breath profiles for the presence of specific volatile metabolites, known as biomarkers or chemical bio-indicators of specific human diseases, metabolic disorders and the overall health status of individuals, are providing the potential for new noninvasive tools and techniques useful to...

Quality of Life Theory II. Quality of Life as the Realization of Life Potential: A Biological Theory of Human Being

Directory of Open Access Journals (Sweden)

Soren Ventegodt

2003-01-01

Full Text Available This review presents one of the eight theories of the quality of life (QOL used for making the SEQOL (self-evaluation of quality of life questionnaire or the quality of life as realizing life potential. This theory is strongly inspired by Maslow and the review furthermore serves as an example on how to fulfill the demand for an overall theory of life (or philosophy of life, which we believe is necessary for global and generic quality-of-life research.Whereas traditional medical science has often been inspired by mechanical models in its attempts to understand human beings, this theory takes an explicitly biological starting point. The purpose is to take a close view of life as a unique entity, which mechanical models are unable to do. This means that things considered to be beyond the individual's purely biological nature, notably the quality of life, meaning in life, and aspirations in life, are included under this wider, biological treatise. Our interpretation of the nature of all living matter is intended as an alternative to medical mechanism, which dates back to the beginning of the 20th century. New ideas such as the notions of the human being as nestled in an evolutionary and ecological context, the spontaneous tendency of self-organizing systems for realization and concord, and the central role of consciousness in interpreting, planning, and expressing human reality are unavoidable today in attempts to scientifically understand all living matter, including human life.

Scanning electron microscopy

Energy Technology Data Exchange (ETDEWEB)

Cox, B. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada)

1970-05-15

The JSM-11 scanning electron microscope at CRNL has been used extensively for topographical studies of oxidized metals, fracture surfaces, entomological and biological specimens. A non-dispersive X-ray attachment permits the microanalysis of the surface features. Techniques for the production of electron channeling patterns have been developed. (author)

[Role of different scale structures of titanium implant in the biological behaviors of human umbilical vein endothelial cells].

Science.gov (United States)

Liang, N W; Shi, L; Huang, Y; Deng, X L

2017-02-18

To study the role of different scale structure of Ti implants on the biological behaviors of human umbilical vein endothelial cell (HUVECs) and to reveal the role of material surface topographical features on peri-implant angiogenesis. Titanium (Ti) discs with different surface structures (Ti discs with smooth surface, Ti discs with nano scale structure, Ti discs with micro scale structure and Ti discs with micro/nano scale structure, named as SM-Ti, Nano-Ti, Micro-Ti and Micro/Nano-Ti, respectively) were prepared and their surface topographical features were confirmed via scanning electron microscopy (SEM) observation. HUVECs were cultured on these Ti discs. Biological outcomes of HUVECs on different surfaces were carried out, including cell adhesive capacity, proliferation, vascular endothelial growth factor (VEGF) production and intracellular expression of Ca(2+). The results of SEM images and immunofluorescence double staining of rhodamine-phalloidin and DAPI showed that compared with the SM-Ti and Nano-Ti group, the adhesive capacity and proliferation behavior of HUVECs on the surfaces of Micro-Ti and Micro/Nano-Ti was decreased. The results of culturing HUVECs on different groups of Ti discs after 24 hours showed that the cells number grew from (18±4) to (42±6)/ vision on SM-Ti, (28±6) to (52±10)/vision on Nano-Ti, (20±4) to (21±6)/vision on Micro-Ti and (16±4) to (18±6)/vision on Micro/Nano-Ti. Moreover, compared with the adhesion and proliferation of HUVECs on SM-Ti group and Nano-Ti, the adhesion and proliferation of HUVECs on Micro-Ti group and Micro/Nano-Ti group was significantly reduced (PMicro-Ti and Micro/Nano-Ti were (690±35) ng/L, (560±20) ng/L, (474±43) ng/L and (517±29) ng/L, respectively. Moreover, compared with the VEGF production of HUVECs on SM-Ti group, the VEGF production of HUVECs on Micro-Ti group and Micro/Nano-Ti group was significantly reduced (PMicro-Ti and Micro/Nano-Ti was significantly higher than that on the surface of

Population Genomics and the Statistical Values of Race:An Interdisciplinary Perspective on the Biological Classification of Human Populations and Implications for Clinical Genetic Epidemiological Research

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Koffi N. Maglo

2016-02-01

Full Text Available The biological status and biomedical significance of the concept of race as applied to humans continue to be contentious issues despite the use of advanced statistical and clustering methods to determine continental ancestry. It is thus imperative for researchers to understand the limitations as well as potential uses of the concept of race in biology and biomedicine. This paper deals with the theoretical assumptions behind cluster analysis in human population genomics. Adopting an interdisciplinary approach, it demonstrates that the hypothesis that attributes the clustering of human populations to frictional effects of landform barriers at continental boundaries is empirically incoherent. It then contrasts the scientific status of the cluster and cline constructs in human population genomics, and shows how cluster may be instrumentally produced. It also shows how statistical values of race vindicate Darwin’s argument that race is evolutionarily meaningless. Finally, the paper explains why, due to spatiotemporal parameters, evolutionary forces and socio-cultural factors influencing population structure, continental ancestry may be pragmatically relevant to global and public health genomics. Overall, this work demonstrates that, from a biological systematic and evolutionary taxonomical perspective, human races/continental groups or clusters have no natural meaning or objective biological reality. In fact, the utility of racial categorizations in research and in clinics can be explained by spatiotemporal parameters, socio-cultural factors and evolutionary forces affecting disease causation and treatment response.

High resolution IVEM tomography of biological specimens

Energy Technology Data Exchange (ETDEWEB)

Sedat, J.W.; Agard, D.A. [Univ. of California, San Francisco, CA (United States)

1997-02-01

Electron tomography is a powerful tool for elucidating the three-dimensional architecture of large biological complexes and subcellular organelles. The introduction of intermediate voltage electron microscopes further extended the technique by providing the means to examine very large and non-symmetrical subcellular organelles, at resolutions beyond what would be possible using light microscopy. Recent studies using electron tomography on a variety of cellular organelles and assemblies such as centrosomes, kinetochores, and chromatin have clearly demonstrated the power of this technique for obtaining 3D structural information on non-symmetric cell components. When combined with biochemical and molecular observations, these 3D reconstructions have provided significant new insights into biological function.

Biological monitoring of radiation exposure

Science.gov (United States)

Horneck, G.

1998-11-01

Complementary to physical dosimetry, biological dosimetry systems have been developed and applied which weight the different components of environmental radiation according to their biological efficacy. They generally give a record of the accumulated exposure of individuals with high sensitivity and specificity for the toxic agent under consideration. Basically three different types of biological detecting/monitoring systems are available: (i) intrinsic biological dosimeters that record the individual radiation exposure (humans, plants, animals) in measurable units. For monitoring ionizing radiation exposure, in situ biomarkers for genetic (e.g. chromosomal aberrations in human lymphocytes, germ line minisatellite mutation rates) or metabolic changes in serum, plasma and blood (e.g. serum lipids, lipoproteins, lipid peroxides, melatonin, antibody titer) have been used. (ii) Extrinsic biological dosimeters/indicators that record the accumulated dose in biological model systems. Their application includes long-term monitoring of changes in environmental UV radiation and its biological implications as well as dosimetry of personal UV exposure. (iii) Biological detectors/biosensors for genotoxic substances and agents such as bacterial assays (e.g. Ames test, SOS-type test) that are highly sensitive to genotoxins with high specificity. They may be applicable for different aspects in environmental monitoring including the International Space Station.

Applications of positron annihilation spectroscopy to polymeric and biological systems

International Nuclear Information System (INIS)

Jean, Y.C.; Chen, Hongmin; Liu, Guang; Chakka, Lakshmi; Gadzia, Joseph E.

2007-01-01

Positron annihilation spectroscopy (PAS) is a novel radio-analytical technique which uses the positron (anti-electron) and is capable of probing the atomic and molecular scale (0.2-2 nm) free-volume and hole properties in polymeric and biological materials. Recently, we developed positron annihilation lifetime and Doppler broadening of energy spectroscopies coupled with a variable mono-energetic positron beam to measure the free-volume depth profile from the surface, interfaces, and to the bulk. This paper presents applications of PAS to determine multi-layer structures, glass transition temperatures in nano-scale polymeric films and to detect cancer in the human skin. (author)

A comprehensive experiment for molecular biology: Determination of single nucleotide polymorphism in human REV3 gene using PCR-RFLP.

Science.gov (United States)

Zhang, Xu; Shao, Meng; Gao, Lu; Zhao, Yuanyuan; Sun, Zixuan; Zhou, Liping; Yan, Yongmin; Shao, Qixiang; Xu, Wenrong; Qian, Hui

2017-07-08

Laboratory exercise is helpful for medical students to understand the basic principles of molecular biology and to learn about the practical applications of molecular biology. We have designed a lab course on molecular biology about the determination of single nucleotide polymorphism (SNP) in human REV3 gene, the product of which is a subunit of DNA polymerase ζ and SNPs in this gene are associated with altered susceptibility to cancer. This newly designed experiment is composed of three parts, including genomic DNA extraction, gene amplification by PCR, and genotyping by RFLP. By combining these activities, the students are not only able to learn a series of biotechniques in molecular biology, but also acquire the ability to link the learned knowledge with practical applications. This comprehensive experiment will help the medical students improve the conceptual understanding of SNP and the technical understanding of SNP detection. © 2017 by The International Union of Biochemistry and Molecular Biology, 45(4):299-304, 2017. © 2017 The International Union of Biochemistry and Molecular Biology.

Novel insights into embryonic stem cell self-renewal revealed through comparative human and mouse systems biology networks.

Science.gov (United States)

Dowell, Karen G; Simons, Allen K; Bai, Hao; Kell, Braden; Wang, Zack Z; Yun, Kyuson; Hibbs, Matthew A

2014-05-01

Embryonic stem cells (ESCs), characterized by their ability to both self-renew and differentiate into multiple cell lineages, are a powerful model for biomedical research and developmental biology. Human and mouse ESCs share many features, yet have distinctive aspects, including fundamental differences in the signaling pathways and cell cycle controls that support self-renewal. Here, we explore the molecular basis of human ESC self-renewal using Bayesian network machine learning to integrate cell-type-specific, high-throughput data for gene function discovery. We integrated high-throughput ESC data from 83 human studies (~1.8 million data points collected under 1,100 conditions) and 62 mouse studies (~2.4 million data points collected under 1,085 conditions) into separate human and mouse predictive networks focused on ESC self-renewal to analyze shared and distinct functional relationships among protein-coding gene orthologs. Computational evaluations show that these networks are highly accurate, literature validation confirms their biological relevance, and reverse transcriptase polymerase chain reaction (RT-PCR) validation supports our predictions. Our results reflect the importance of key regulatory genes known to be strongly associated with self-renewal and pluripotency in both species (e.g., POU5F1, SOX2, and NANOG), identify metabolic differences between species (e.g., threonine metabolism), clarify differences between human and mouse ESC developmental signaling pathways (e.g., leukemia inhibitory factor (LIF)-activated JAK/STAT in mouse; NODAL/ACTIVIN-A-activated fibroblast growth factor in human), and reveal many novel genes and pathways predicted to be functionally associated with self-renewal in each species. These interactive networks are available online at www.StemSight.org for stem cell researchers to develop new hypotheses, discover potential mechanisms involving sparsely annotated genes, and prioritize genes of interest for experimental validation

Study and structural and chemical characterization of human dental smalt by electron microscopy

International Nuclear Information System (INIS)

Belio R, I.A.; Reyes G, J.

1998-01-01

The study of human dental smalt has been subject to investigation for this methods with electron microscopy, electron diffraction, X-ray diffraction and image simulation programs have been used with the purpose to determine its chemical and structural characteristics of the organic and inorganic materials. This work has been held mainly for the characterization of hydroxyapatite (Ca) 10 (PO 4 ) 6 (OH 4 ) 2 , inorganic material which conforms the dental smalt in 97%, so observing its structural unity which is composed by the prisms and these by crystals and atoms. It was subsequently initiated the study of the organic material, with is precursor of itself. (Author)

Biological evaluation of recombinant human erythropoietin in pharmaceutical products

Directory of Open Access Journals (Sweden)

Ramos A.S.

2003-01-01

Full Text Available The potencies of mammalian cell-derived recombinant human erythropoietin pharmaceutical preparations, from a total of five manufacturers, were assessed by in vivo bioassay using standardized protocols. Eight-week-old normocythemic mice received a single subcutaneous injection followed by blood sampling 96 h later or multiple daily injections with blood sampling 24 h after the last injection. Reticulocyte counting by microscopic examination was employed as the end-point using the brilliant cresyl blue or selective hemolysis methods, together with automated flow cytometry. Different injection schedules were investigated and dose-response curves for the European Pharmacopoeia Biological Reference Preparation of erythropoietin were compared. Manual and automated methods of reticulocyte counting were correlated with respect to assay validity and precision. Using 8 mice per treatment group, intra-assay precision determined for all of the assays in the study showed coefficients of variation of 12.1-28.4% for the brilliant cresyl blue method, 14.1-30.8% for the selective hemolysis method and 8.5-19.7% for the flow cytometry method. Applying the single injection protocol, a combination of at least two independent assays was required to achieve the precision potency and confidence limits indicated by the manufacturers, while the multiple daily injection protocol yielded the same acceptable results within a single assay. Although the latter protocol using flow cytometry for reticulocyte counting gave more precise and reproducible results (intra-assay coefficients of variation: 5.9-14.2%, the well-characterized manual methods provide equally valid alternatives for the quality control of recombinant human erythropoietin therapeutic products.

Radiation cytogenetic in vitro studies on human donors in the development of a suitable biological dosimeter

International Nuclear Information System (INIS)

Barjaktarovic, N.

1988-02-01

The final report is on the work carried out under the Agency research contract 3173/RB entitled ''Radiation cytogenetic in vitro studies on human donors in the development of a suitable biological dosimeter'', at the Clinical Hospital Centre ''Zvezdara'' in Belgrade, Yugoslavia. In co-operation and co-ordination dissemination with an international team of cytogeneticists under the IAEA CRP, the development of a suitable biological dosimetry system has been accomplished at the national institute to assist reliably in the absorbed radiation-dose assessment of accidentally-over-exposed personnel. The quantitative yield of asymmetrical chromosomal aberrations, such as dicentrics, rings and fragments consequent to exposure(s) to radiation overdose, help in such estimation of vital prognostic and radiation protection significance. This biological dosimeter system is particularly essential where the exposed person was not wearing any physical dosemeter during the accident. Prerequisite for implementation of an effective biological dosimetry is the availability of a reliable standard dose-response curve and an adherence to a protocol for lymphocytic chromosome analysis in first division phase of lymphocytes. The validation of the reported biological dosimeter is established through its successful analysis of a simulated over-exposure incident, with the associated error of less than 10%. Analytical cytogenetic methods for whole- and part-body acute exposures have been discussed. Part of the results have been reported in the publications under the CRP concerned

Tritium biological effects and perspective of the biological study

International Nuclear Information System (INIS)

Komatsu, Kenshi

1998-01-01

Since tritium is an emitter of weak β-rays (5.7keV) and is able to bind to DNA, i.e., the most important genome component, the biological effects should be expected to be more profound than that of X-rays and γ-rays. When carcinogenesis, genetical effects and the detriments for fetus and embryo were used as a biological endpoint, most of tritium RBE (relative biological effectiveness) ranged from 1 to 2. The tritium risk in man could be calculated from these RBEs and γ-ray risk for human exposure, which are obtained mainly from the data on Atomic Bomb survivors. However, the exposure modality from environmental tritium should be a chronic irradiation with ultra low dose rate or a fractionated irradiation. We must estimate the tritium effect in man based on biological experiments alone, due to lack of such epidemiological data. Low dose rate experiment should be always accompanied by the statistical problem of data, since their biological effects are fairy low, and they should involve a possible repair system, such as adaptive response (or hormesis effect) and 'Kada effect' observed in bacteria. Here we discuss future works for the tritium assessment in man, such as (1) developing a high radiation sensitive assay system with rodent hybrid cells containing a single human chromosome and also (2) study on mammal DNA repair at molecular levels using a radiosensitive hereditary disease, Nijmegen Breakage Syndrome. (author)

Specific absorbed fractions of electrons and photons for Rad-HUMAN phantom using Monte Carlo method

International Nuclear Information System (INIS)

Wang Wen; Hu Liqin; Cheng Mengyun; Long Pengcheng

2015-01-01

The specific absorbed fractions (SAF) for self- and cross-irradiation are effective tools for the internal dose estimation of inhalation and ingestion intakes of radionuclides. A set of SAFs of photons and electrons were calculated using the Rad-HUMAN phantom, which is a computational voxel phantom of a Chinese adult female that was created using the color photographic image of the Chinese Visible Human (CVH) data set by the FDS Team. The model can represent most Chinese adult female anatomical characteristics and can be taken as an individual phantom to investigate the difference of internal dose with Caucasians. In this study, the emission of mono-energetic photons and electrons of 10 keV to 4 MeV energy were calculated using the Monte Carlo particle transport calculation code MCNP. Results were compared with the values from ICRP reference and ORNL models. The results showed that SAF from the Rad-HUMAN have similar trends but are larger than those from the other two models. The differences were due to the racial and anatomical differences in organ mass and inter-organ distance. The SAFs based on the Rad-HUMAN phantom provide an accurate and reliable data for internal radiation dose calculations for Chinese females. (authors)

Melatonin the "light of night" in human biology and adolescent idiopathic scoliosis

Directory of Open Access Journals (Sweden)

Savvidou Olga D

2007-04-01

Full Text Available Abstract Melatonin "the light of night" is secreted from the pineal gland principally at night. The hormone is involved in sleep regulation, as well as in a number of other cyclical bodily activities and circadian rhythm in humans. Melatonin is exclusively involved in signalling the 'time of day' and 'time of year' (hence considered to help both clock and calendar functions to all tissues and is thus considered to be the body's chronological pacemaker or 'Zeitgeber'. The last decades melatonin has been used as a therapeutic chemical in a large spectrum of diseases, mainly in sleep disturbances and tumours and may play a role in the biologic regulation of mood, affective disorders, cardiovascular system, reproduction and aging. There are few papers regarding melatonin and its role in adolescent idiopathic scoliosis (AIS. Melatonin may play a role in the pathogenesis of scoliosis (neuroendocrine hypothesis but at present, the data available cannot clearly support this hypothesis. Uncertainties and doubts still surround the role of melatonin in human physiology and pathophysiology and future research is needed.

Biospheric Life Support - integrating biological regeneration into protection of humans in space.

Science.gov (United States)

Rocha, Mauricio; Iha, Koshun

2016-07-01

A biosphere stands for a set of biomes (regional biological communities) interacting in a materially closed (though energetically open) ecological system (CES). Earth's biosphere, the thin layer of life on the planet's surface, can be seen as a natural CES- where life "consumables" are regenerated/restored via biological, geological and chemical processes. In Life Sciences, artificial CESs- local ecosystems extracts with varying scales and degrees of closure, are considered convenient/representatives objects of study. For outer space, these concepts have been applied to the issue of life support- a significant consideration as long as distance from Earth increases. In the nineties, growing on the Russian expertise on biological life support, backed by a multidisciplinary science team, the famous Biosphere 2 appeared. That private project innovated, by assembling a set of Earth biomes samples- plus an organic ag one, inside a closed Mars base-like structure, next to 1.5 ha under glass, in Arizona, US. The crew of 8 inside completed their two years contract, though facing setbacks- the system failed, e.g., to produce enough food/air supplies. But their "failures"- if this word can be fairly applied to science endeavors, were as meaningful as their achievements for the future of life support systems (LSS) research. By this period, the Russians had accumulated experience in extended orbital stays, achieving biological outcomes inside their stations- e.g. complete wheat cycles. After reaching the Moon, the US administration decided to change national priorities, putting the space program as part of a "détente" policy, to relieve international tensions. Alongside the US space shuttle program, the Russians were invited to join the new International Space Station (ISS), bringing to that pragmatic project, also their physical/chemical LSS- top air/water regenerative technology at the time. Present US policy keeps the ISS operational, extending its service past its planned

Effects of different external carbon sources and electron acceptors on interactions between denitrification and phosphorus removal in biological nutrient removal processes.

Science.gov (United States)

Hu, Xiang; Sobotka, Dominika; Czerwionka, Krzysztof; Zhou, Qi; Xie, Li; Makinia, Jacek

The effects of two different external carbon sources (acetate and ethanol) and electron acceptors (dissolved oxygen, nitrate, and nitrite) were investigated under aerobic and anoxic conditions with non-acclimated process biomass from a full-scale biological nutrient removal-activated sludge system. When acetate was added as an external carbon source, phosphate release was observed even in the presence of electron acceptors. The release rates were 1.7, 7.8, and 3.5 mg P/(g MLVSS·h) (MLVSS: mixed liquor volatile suspended solids), respectively, for dissolved oxygen, nitrate, and nitrite. In the case of ethanol, no phosphate release was observed in the presence of electron acceptors. Results of the experiments with nitrite showed that approximately 25 mg NO 2 -N/L of nitrite inhibited anoxic phosphorus uptake regardless of the concentration of the tested external carbon sources. Furthermore, higher denitrification rates were obtained with acetate (1.4 and 0.8 mg N/(g MLVSS·h)) compared to ethanol (1.1 and 0.7 mg N/ (g MLVSS·h)) for both anoxic electron acceptors (nitrate and nitrite).

Applications of tissue heterogeneity corrections and biologically effective dose volume histograms in assessing the doses for accelerated partial breast irradiation using an electronic brachytherapy source

Science.gov (United States)

Shi, Chengyu; Guo, Bingqi; Cheng, Chih-Yao; Eng, Tony; Papanikolaou, Nikos

2010-09-01

A low-energy electronic brachytherapy source (EBS), the model S700 Axxent™ x-ray device developed by Xoft Inc., has been used in high dose rate (HDR) intracavitary accelerated partial breast irradiation (APBI) as an alternative to an Ir-192 source. The prescription dose and delivery schema of the electronic brachytherapy APBI plan are the same as the Ir-192 plan. However, due to its lower mean energy than the Ir-192 source, an EBS plan has dosimetric and biological features different from an Ir-192 source plan. Current brachytherapy treatment planning methods may have large errors in treatment outcome prediction for an EBS plan. Two main factors contribute to the errors: the dosimetric influence of tissue heterogeneities and the enhancement of relative biological effectiveness (RBE) of electronic brachytherapy. This study quantified the effects of these two factors and revisited the plan quality of electronic brachytherapy APBI. The influence of tissue heterogeneities is studied by a Monte Carlo method and heterogeneous 'virtual patient' phantoms created from CT images and structure contours; the effect of RBE enhancement in the treatment outcome was estimated by biologically effective dose (BED) distribution. Ten electronic brachytherapy APBI cases were studied. The results showed that, for electronic brachytherapy cases, tissue heterogeneities and patient boundary effect decreased dose to the target and skin but increased dose to the bones. On average, the target dose coverage PTV V100 reduced from 95.0% in water phantoms (planned) to only 66.7% in virtual patient phantoms (actual). The actual maximum dose to the ribs is 3.3 times higher than the planned dose; the actual mean dose to the ipsilateral breast and maximum dose to the skin were reduced by 22% and 17%, respectively. Combining the effect of tissue heterogeneities and RBE enhancement, BED coverage of the target was 89.9% in virtual patient phantoms with RBE enhancement (actual BED) as compared to 95

Applications of tissue heterogeneity corrections and biologically effective dose volume histograms in assessing the doses for accelerated partial breast irradiation using an electronic brachytherapy source

Energy Technology Data Exchange (ETDEWEB)

Shi Chengyu; Guo Bingqi; Eng, Tony; Papanikolaou, Nikos [Cancer Therapy and Research Center, University of Texas Health Science Center at San Antonio, TX 78229 (United States); Cheng, Chih-Yao, E-mail: shic@uthscsa.ed [Radiation Oncology Department, Oklahoma University Health Science Center, Oklahoma, OK 73104 (United States)

2010-09-21

A low-energy electronic brachytherapy source (EBS), the model S700 Axxent(TM) x-ray device developed by Xoft Inc., has been used in high dose rate (HDR) intracavitary accelerated partial breast irradiation (APBI) as an alternative to an Ir-192 source. The prescription dose and delivery schema of the electronic brachytherapy APBI plan are the same as the Ir-192 plan. However, due to its lower mean energy than the Ir-192 source, an EBS plan has dosimetric and biological features different from an Ir-192 source plan. Current brachytherapy treatment planning methods may have large errors in treatment outcome prediction for an EBS plan. Two main factors contribute to the errors: the dosimetric influence of tissue heterogeneities and the enhancement of relative biological effectiveness (RBE) of electronic brachytherapy. This study quantified the effects of these two factors and revisited the plan quality of electronic brachytherapy APBI. The influence of tissue heterogeneities is studied by a Monte Carlo method and heterogeneous 'virtual patient' phantoms created from CT images and structure contours; the effect of RBE enhancement in the treatment outcome was estimated by biologically effective dose (BED) distribution. Ten electronic brachytherapy APBI cases were studied. The results showed that, for electronic brachytherapy cases, tissue heterogeneities and patient boundary effect decreased dose to the target and skin but increased dose to the bones. On average, the target dose coverage PTV V{sub 100} reduced from 95.0% in water phantoms (planned) to only 66.7% in virtual patient phantoms (actual). The actual maximum dose to the ribs is 3.3 times higher than the planned dose; the actual mean dose to the ipsilateral breast and maximum dose to the skin were reduced by 22% and 17%, respectively. Combining the effect of tissue heterogeneities and RBE enhancement, BED coverage of the target was 89.9% in virtual patient phantoms with RBE enhancement (actual BED) as

Applications of tissue heterogeneity corrections and biologically effective dose volume histograms in assessing the doses for accelerated partial breast irradiation using an electronic brachytherapy source

International Nuclear Information System (INIS)

Shi Chengyu; Guo Bingqi; Eng, Tony; Papanikolaou, Nikos; Cheng, Chih-Yao

2010-01-01

A low-energy electronic brachytherapy source (EBS), the model S700 Axxent(TM) x-ray device developed by Xoft Inc., has been used in high dose rate (HDR) intracavitary accelerated partial breast irradiation (APBI) as an alternative to an Ir-192 source. The prescription dose and delivery schema of the electronic brachytherapy APBI plan are the same as the Ir-192 plan. However, due to its lower mean energy than the Ir-192 source, an EBS plan has dosimetric and biological features different from an Ir-192 source plan. Current brachytherapy treatment planning methods may have large errors in treatment outcome prediction for an EBS plan. Two main factors contribute to the errors: the dosimetric influence of tissue heterogeneities and the enhancement of relative biological effectiveness (RBE) of electronic brachytherapy. This study quantified the effects of these two factors and revisited the plan quality of electronic brachytherapy APBI. The influence of tissue heterogeneities is studied by a Monte Carlo method and heterogeneous 'virtual patient' phantoms created from CT images and structure contours; the effect of RBE enhancement in the treatment outcome was estimated by biologically effective dose (BED) distribution. Ten electronic brachytherapy APBI cases were studied. The results showed that, for electronic brachytherapy cases, tissue heterogeneities and patient boundary effect decreased dose to the target and skin but increased dose to the bones. On average, the target dose coverage PTV V 100 reduced from 95.0% in water phantoms (planned) to only 66.7% in virtual patient phantoms (actual). The actual maximum dose to the ribs is 3.3 times higher than the planned dose; the actual mean dose to the ipsilateral breast and maximum dose to the skin were reduced by 22% and 17%, respectively. Combining the effect of tissue heterogeneities and RBE enhancement, BED coverage of the target was 89.9% in virtual patient phantoms with RBE enhancement (actual BED) as compared to 95

Electronic Integrated Disease Surveillance System and Pathogen Asset Control System

Directory of Open Access Journals (Sweden)

Tom G. Wahl

2012-06-01

Full Text Available Electronic Integrated Disease Surveillance System (EIDSS has been used to strengthen and support monitoring and prevention of dangerous diseases within One Health concept by integrating veterinary and human surveillance, passive and active approaches, case-based records including disease-specific clinical data based on standardised case definitions and aggregated data, laboratory data including sample tracking linked to each case and event with test results and epidemiological investigations. Information was collected and shared in secure way by different means: through the distributed nodes which are continuously synchronised amongst each other, through the web service, through the handheld devices. Electronic Integrated Disease Surveillance System provided near real time information flow that has been then disseminated to the appropriate organisations in a timely manner. It has been used for comprehensive analysis and visualisation capabilities including real time mapping of case events as these unfold enhancing decision making. Electronic Integrated Disease Surveillance System facilitated countries to comply with the IHR 2005 requirements through a data transfer module reporting diseases electronically to the World Health Organisation (WHO data center as well as establish authorised data exchange with other electronic system using Open Architecture approach. Pathogen Asset Control System (PACS has been used for accounting, management and control of biological agent stocks. Information on samples and strains of any kind throughout their entire lifecycle has been tracked in a comprehensive and flexible solution PACS. Both systems have been used in a combination and individually. Electronic Integrated Disease Surveillance System and PACS are currently deployed in the Republics of Kazakhstan, Georgia and Azerbaijan as a part of the Cooperative Biological Engagement Program (CBEP sponsored by the US Defense Threat Reduction Agency (DTRA.

Electronic integrated disease surveillance system and pathogen asset control system.

Science.gov (United States)

Wahl, Tom G; Burdakov, Aleksey V; Oukharov, Andrey O; Zhilokov, Azamat K

2012-06-20

Electronic Integrated Disease Surveillance System (EIDSS) has been used to strengthen and support monitoring and prevention of dangerous diseases within One Health concept by integrating veterinary and human surveillance, passive and active approaches, case-based records including disease-specific clinical data based on standardised case definitions and aggregated data, laboratory data including sample tracking linked to each case and event with test results and epidemiological investigations. Information was collected and shared in secure way by different means: through the distributed nodes which are continuously synchronised amongst each other, through the web service, through the handheld devices. Electronic Integrated Disease Surveillance System provided near real time information flow that has been then disseminated to the appropriate organisations in a timely manner. It has been used for comprehensive analysis and visualisation capabilities including real time mapping of case events as these unfold enhancing decision making. Electronic Integrated Disease Surveillance System facilitated countries to comply with the IHR 2005 requirements through a data transfer module reporting diseases electronically to the World Health Organisation (WHO) data center as well as establish authorised data exchange with other electronic system using Open Architecture approach. Pathogen Asset Control System (PACS) has been used for accounting, management and control of biological agent stocks. Information on samples and strains of any kind throughout their entire lifecycle has been tracked in a comprehensive and flexible solution PACS.Both systems have been used in a combination and individually. Electronic Integrated Disease Surveillance System and PACS are currently deployed in the Republics of Kazakhstan, Georgia and Azerbaijan as a part of the Cooperative Biological Engagement Program (CBEP) sponsored by the US Defense Threat Reduction Agency (DTRA).

Institute for Genomics and Systems Biology

Science.gov (United States)

Institute for Genomics and Systems Biology Discover. Predict. Improve. Advancing Human and , 2015 See all Research Papers Featured Video Introduction to Systems Biology Video: Introduction to Systems Biology News Jack Gilbert Heading UChicago Startup that Aims to Predict Behavior of Trillions of

Human biological monitoring for exposure assessment in response to an incident involving hazardous materials.

Science.gov (United States)

Scheepers, Paul T J; van Brederode, Nelly E; Bos, Peter M J; Nijhuis, Nicole J; van de Weerdt, Rik H J; van der Woude, Irene; Eggens, Martin L

2014-12-15

Biological monitoring in humans (HBM) is widely used in the field of occupational and environmental health. In the situation of an unexpected release of hazardous materials HBM may contribute to the medical support and treatment of exposed individuals from the general population or of emergency responders. Such exposure information may also be used to respond to individual concerns such as questions about a possible relationship between the chemicals released during the incident and health effects. In The Netherlands a guideline was prepared to support early decision-making about the possible use of HBM for exposure assessment during or as soon as possible following a chemical incident. The application of HBM in such an emergency setting is not much different from situations where HBM is normally used but there are some issues that need extra attention such as the choice of the biomarker, the biological media to be sampled, the time point at which biological samples should be collected, the ethics approval and technical implementation of the study protocol and the interpretation and communication of the study results. These issues addressed in the new guideline will support the use of HBM in the management of chemical disasters. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Marine molecular biology: an emerging field of biological sciences.

Science.gov (United States)

Thakur, Narsinh L; Jain, Roopesh; Natalio, Filipe; Hamer, Bojan; Thakur, Archana N; Müller, Werner E G

2008-01-01

An appreciation of the potential applications of molecular biology is of growing importance in many areas of life sciences, including marine biology. During the past two decades, the development of sophisticated molecular technologies and instruments for biomedical research has resulted in significant advances in the biological sciences. However, the value of molecular techniques for addressing problems in marine biology has only recently begun to be cherished. It has been proven that the exploitation of molecular biological techniques will allow difficult research questions about marine organisms and ocean processes to be addressed. Marine molecular biology is a discipline, which strives to define and solve the problems regarding the sustainable exploration of marine life for human health and welfare, through the cooperation between scientists working in marine biology, molecular biology, microbiology and chemistry disciplines. Several success stories of the applications of molecular techniques in the field of marine biology are guiding further research in this area. In this review different molecular techniques are discussed, which have application in marine microbiology, marine invertebrate biology, marine ecology, marine natural products, material sciences, fisheries, conservation and bio-invasion etc. In summary, if marine biologists and molecular biologists continue to work towards strong partnership during the next decade and recognize intellectual and technological advantages and benefits of such partnership, an exciting new frontier of marine molecular biology will emerge in the future.

Inalienably Yours? The new case for an inalienable property right in human biological material: Empowerment of sample donors or a recipe for a tragic Anti-Commons?

Directory of Open Access Journals (Sweden)

Jasper A. Bovenberg

2004-12-01

Full Text Available Modern biomedical research into the genetic component of common diseases calls for broad access to existing and novel collections of samples of human biological material, aka Biobanks. Groups of donors of these samples, however, increasingly claim a property right in their samples. They perceive the recognition of a personal property right in their biological material as the best means to serve two goals: to secure ongoing control over their samples after donation and to underpin their claim for a share in the proceeds that the research on their samples may yield. Given the objective of ensuring ongoing control, this property right is claimed to be inalienable. Recognition of a personal property right in one’s biological material is problematic, especially where the requirement of inalienability seems at odds with the claim for a share of the profits. Yet, property rights in human biological material may be justified in a certain context, e.g. to enable subsets of patients to negotiate the terms and conditions of the research into their specific disorders. Biobanks, however, contain so many samples, which can be used for so many research purposes, that the unrestricted exercise of personal property rights by the sample donors will lead to a proliferation of rights. This proliferation is likely to deter or slow down both the creation of de novo Biobanks and the use of existing sample collections. Thus, recognising inalienable property rights in human biological material may lead to suboptimal use of these resources and create a classic ‘anticommons property’ scenario. It would also undermine the current trend to simplify existing informed consent requirements which aims to facilitate broad and previously unanticipated research on de novo and existing Biobanks. In addition, the tradition of altruistic participation in research and the notion that large-scale collections of human biological material are global public goods are arguments against

Can Chimpanzee Biology Highlight Human Origin and Evolution?

Directory of Open Access Journals (Sweden)

Itai Roffman

2010-07-01

Full Text Available The closest living relatives of humans are their chimpanzee/bonobo (Pan sister species, members of the same subfamily “Homininae”. This classification is supported by over 50 years of research in the fields of chimpanzee cultural diversity, language competency, genomics, anatomy, high cognition, psychology, society, self-consciousness and relation to others, tool use/production, as well as Homo level emotions, symbolic competency, memory recollection, complex multifaceted problem-solving capabilities, and interspecies communication. Language competence and symbolism can be continuously bridged from chimpanzee to man. Emotions, intercommunity aggression, body language, gestures, facial expressions, and vocalization of intonations seem to parallel between the sister taxa Homo and Pan. The shared suite of traits between Pan and Homo genus demonstrated in this article integrates old and new information on human–chimpanzee evolution, bilateral informational and cross-cultural exchange, promoting the urgent need for Pan cultures in the wild to be protected, as they are part of the cultural heritage of mankind. Also, we suggest that bonobos, Pan paniscus, based on shared traits with Australopithecus, need to be included in Australopithecine’s subgenus, and may even represent living-fossil Australopithecines. Unfolding bonobo and chimpanzee biology highlights our common genetic and cultural evolutionary origins.

Revisit of Machine Learning Supported Biological and Biomedical Studies.

Science.gov (United States)

Yu, Xiang-Tian; Wang, Lu; Zeng, Tao

2018-01-01

Generally, machine learning includes many in silico methods to transform the principles underlying natural phenomenon to human understanding information, which aim to save human labor, to assist human judge, and to create human knowledge. It should have wide application potential in biological and biomedical studies, especially in the era of big biological data. To look through the application of machine learning along with biological development, this review provides wide cases to introduce the selection of machine learning methods in different practice scenarios involved in the whole biological and biomedical study cycle and further discusses the machine learning strategies for analyzing omics data in some cutting-edge biological studies. Finally, the notes on new challenges for machine learning due to small-sample high-dimension are summarized from the key points of sample unbalance, white box, and causality.

Influence of Bicarbonate, Sulfate, and Electron Donors on Biological reduction of Uranium and Microbial Community Composition

Energy Technology Data Exchange (ETDEWEB)

Luo, Wensui [ORNL; Zhou, Jizhong [ORNL; Wu, Weimin [ORNL; Yan, Tingfen [ORNL; Criddle, Craig [ORNL; Jardine, Philip M [ORNL; Gu, Baohua [ORNL

2007-01-01

A microcosm study was performed to investigate the effect of ethanol and acetate on uranium(VI) biological reduction and microbial community changes under various geochemical conditions. Each microcosm contained an uranium-contaminated sediment (up to 2.8 g U/kg) suspended in buffer with bicarbonate at concentrations of either 1 mM or 40 mM and sulfate at either 1.1 or 3.2 mM. Ethanol or acetate was used as an electron donor. Results indicate that ethanol yielded in significantly higher U(VI) reduction rates than acetate. A low bicarbonate concentration (1 mM) was favored for U(VI) bioreduction to occur in sediments, but high concentrations of bicarbonate (40 mM) and sulfate (3.2 mM) decreased the reduction rates of U(VI). Microbial communities were dominated by species from the Geothrix genus and Proteobacteria phylum in all microcosms. However, species in the Geobacteraceae family capable of reducing U(VI) were significantly enriched by ethanol and acetate in low bicarbonate buffer. Ethanol increased the population of unclassified Desulfuromonales, while acetate increased the population of Desulfovibrio. Additionally, species in the Geobacteraceae family were not enriched in high bicarbonate buffer, but the Geothrix and the unclassified Betaproteobacteria species were enriched. This study concludes that ethanol could be a better electron donor than acetate for reducing U(VI) under given experimental conditions, and electron donor and geoundwater geochemistry alter microbial communities responsible for U(VI) reduction.

Influence of bicarbonate, sulfate, and electron donors on biological reduction of uranium and microbial community composition

Energy Technology Data Exchange (ETDEWEB)

Luo Wensui [Oak Ridge Inst. for Science and Education, TN (United States); Oak Ridge National Lab., TN (United States). Environmental Sciences Div.; Wu Wei-Min; Criddle, C.S. [Stanford Univ., CA (United States). Dept. of Civil and Environmental Engineering; Yan Tingfen [Oak Ridge Inst. for Science and Education, TN (United States); Jardine, P.M.; Gu Baohua [Oak Ridge National Lab., TN (United States). Environmental Sciences Div.; Zhou Jizhong [Oklahoma Univ., Norman, OK (United States). Dept. of Botany and Microbiology

2007-12-15

A microcosm study was performed to investigate the effect of ethanol and acetate on uranium(VI) biological reduction and microbial community changes under various geochemical conditions. Each microcosm contained an uranium-contaminated sediment (up to 2.8 g U/kg) suspended in buffer with bicarbonate at concentrations of either 1 or 40 mM and sulfate at either 1.1 or 3.2 mM. Ethanol or acetate was used as an electron donor. Results indicate that ethanol yielded in significantly higher U(VI) reduction rates than acetate. A low bicarbonate concentration (1 mM) was favored for U(VI) bioreduction to occur in sediments, but high concentrations of bicarbonate (40 mM) and sulfate (3.2 mM) decreased the reduction rates of U(VI). Microbial communities were dominated by species from the Geothrix genus and Proteobacteria phylum in all microcosms. However, species in the Geobacteraceae family capable of reducing U(VI) were significantly enriched by ethanol and acetate in low-bicarbonate buffer. Ethanol increased the population of unclassified Desulfuromonales, while acetate increased the population of Desulfovibrio. Additionally, species in the Geobacteraceae family were not enriched in high-bicarbonate buffer, but the Geothrix and the unclassified Betaproteobacteria species were enriched. This study concludes that ethanol could be a better electron donor than acetate for reducing U(VI) under given experimental conditions, and electron donor and groundwater geochemistry alter microbial communities responsible for U(VI) reduction. (orig.)

Increased biological activity of deglycosylated recombinant human granulocyte/macrophage colony-stimulating factor produced by yeast or animal cells

International Nuclear Information System (INIS)

Moonen, P.; Mermod, J.J.; Ernst, J.F.; Hirschi, M.; DeLamarter, J.F.

1987-01-01

Human granulocyte/macrophage colony-stimulating factor (hGM-CSF) produced by several recombinant sources including Escherichia coli, yeast, and animal cells was studied. Recombinant animal cells produced hGM-CSF in low quantities and in multiple forms of varying size. Mammalian hGM-CSF was purified 200,000-fold using immunoaffinity and lectin chromatography. Partially purified proteins produced in yeast and mammalian cells were assayed for the effects of deglycosylation. Following enzymatic deglycosylation, immunoreactivity was measured by radioimmunoassay and biological activity was measured in vitro on responsive human primary cells. Removal of N-linked oligosaccharides from both proteins increased their immunoreactivities by 4- to 8-fold. Removal of these oligosaccharides also increased their specific biological activities about 20-fold, to reach approximately the specific activity of recombinant hGM-CSF from E. coli. The E. coli produced-protein-lacking any carbohydrate- had by far the highest specific activity observed for the recombinant hGM-CSFs

Ethics and law in research with human biological samples: a new approach.

Science.gov (United States)

Petrini, Carlo

2014-01-01

During the last century a large number of documents (regulations, ethical codes, treatises, declarations, conventions) were published on the subject of ethics and clinical trials, many of them focusing on the protection of research participants. More recently various proposals have been put forward to relax some of the constraints imposed on research by these documents and regulations. It is important to distinguish between risks deriving from direct interventions on human subjects and other types of risk. In Italy the Data Protection Authority has acted in the question of research using previously collected health data and biological samples to simplify the procedures regarding informed consent. The new approach may be of help to other researchers working outside Italy.

Disregarded Effect of Biological Fluids in siRNA Delivery: Human Ascites Fluid Severely Restricts Cellular Uptake of Nanoparticles.

Science.gov (United States)

Dakwar, George R; Braeckmans, Kevin; Demeester, Joseph; Ceelen, Wim; De Smedt, Stefaan C; Remaut, Katrien

2015-11-04

Small interfering RNA (siRNA) offers a great potential for the treatment of various diseases and disorders. Nevertheless, inefficient in vivo siRNA delivery hampers its translation into the clinic. While numerous successful in vitro siRNA delivery stories exist in reduced-protein conditions, most studies so far overlook the influence of the biological fluids present in the in vivo environment. In this study, we compared the transfection efficiency of liposomal formulations in Opti-MEM (low protein content, routinely used for in vitro screening) and human undiluted ascites fluid obtained from a peritoneal carcinomatosis patient (high protein content, representing the in vivo situation). In Opti-MEM, all formulations are biologically active. In ascites fluid, however, the biological activity of all lipoplexes is lost except for lipofectamine RNAiMAX. The drop in transfection efficiency was not correlated to the physicochemical properties of the nanoparticles, such as premature siRNA release and aggregation of the nanoparticles in the human ascites fluid. Remarkably, however, all of the formulations except for lipofectamine RNAiMAX lost their ability to be taken up by cells following incubation in ascites fluid. To take into account the possible effects of a protein corona formed around the nanoparticles, we recommend always using undiluted biological fluids for the in vitro optimization of nanosized siRNA formulations next to conventional screening in low-protein content media. This should tighten the gap between in vitro and in vivo performance of nanoparticles and ensure the optimal selection of nanoparticles for further in vivo studies.

Constraints on Biological Mechanism from Disease Comorbidity Using Electronic Medical Records and Database of Genetic Variants.

Directory of Open Access Journals (Sweden)

Steven C Bagley

2016-04-01

Full Text Available Patterns of disease co-occurrence that deviate from statistical independence may represent important constraints on biological mechanism, which sometimes can be explained by shared genetics. In this work we study the relationship between disease co-occurrence and commonly shared genetic architecture of disease. Records of pairs of diseases were combined from two different electronic medical systems (Columbia, Stanford, and compared to a large database of published disease-associated genetic variants (VARIMED; data on 35 disorders were available across all three sources, which include medical records for over 1.2 million patients and variants from over 17,000 publications. Based on the sources in which they appeared, disease pairs were categorized as having predominant clinical, genetic, or both kinds of manifestations. Confounding effects of age on disease incidence were controlled for by only comparing diseases when they fall in the same cluster of similarly shaped incidence patterns. We find that disease pairs that are overrepresented in both electronic medical record systems and in VARIMED come from two main disease classes, autoimmune and neuropsychiatric. We furthermore identify specific genes that are shared within these disease groups.

Distinguishing Biologically Controlled Calcareous Biomineralization in Fossil Organisms Using Electron Backscatter Diffraction (EBSD)

Science.gov (United States)

Päßler, Jan-Filip; Jarochowska, Emilia; Bestmann, Michel; Munnecke, Axel

2018-02-01

Although carbonate-precipitating cyanobacteria are ubiquitous in aquatic ecosystems today, the criteria used to identify them in the geological record are subjective and rarely testable. Differences in the mode of biomineralization between cyanobacteria and eukaryotes, i.e. biologically induced calcification (BIM) vs. biologically controlled calcification (BCM), result in different crystallographic structures which might be used as a criterion to test cyanobacterial affinities. Cyanobacteria are often used as a ‘wastebasket taxon’, to which various microfossils are assigned. The lack of a testable criterion for the identification of cyanobacteria may bias their fossil record severely. We employed electron backscatter diffraction (EBSD) to investigate the structure of calcareous skeletons in two microproblematica widespread in Palaeozoic marine ecosystems: Rothpletzella, hypothesized to be a cyanobacterium, and an incertae sedis microorganism Allonema. We used a calcareous trilobite shell as a BCM reference. The mineralized structure of Allonema has a simple single-layered structure of acicular crystals perpendicular to the surface of the organism. The c-axes of these crystals are parallel to the elongation and thereby normal to the surface of the organism. EBSD pole figures and misorientation axes distribution reveal a fibre texture around the c-axis with a small degree of variation (up to 30°), indicating a highly ordered structure. A comparable pattern was found in the trilobite shell. This structure allows excluding biologically induced mineralization as the mechanism of shell formation in Allonema. In Rothpletzella, the c-axes of the microcrystalline sheath show a broader clustering compared to Allonema, but still reveal crystals tending to be perpendicular to the surface of the organism. The misorientation axes of adjacent crystals show an approximately random distribution. Rothpletzella also shares morphological similarities with extant cyanobacteria. We

Understanding the biological effects of thorium in human cells and animals and developing efficient approaches for its decorporation and mitigation

International Nuclear Information System (INIS)

Kumar, Amit; Ali, Manjoor; Pandey, Badri N.

2016-01-01

Thorium-232 (Th) is being realized as a potential source of nuclear fuel for meeting long-term energy generation in India/other nations. In view of utilizing Th, it is hoped that mining, extraction, purification, back-end processing and disposal would increase significantly in near future. Therefore, understanding the biological effects of Th would enable its efficient utilization with adequate human health protection. Biological half-life and associated health effects of Th govern by its speciation, bio-kinetics, radiation decay and organ-specific accumulation due to Fe-like behaviour inside the body system. Our animal studies showed that Th mainly accumulates in liver and bone, in contrast to the accumulation of uranium in kidney. Cell culture experiments were performed to study the binding/internalization mechanism of Th (IV) with human liver cells (HepG2). Experiments using HepG2 cells suggested the role of transferrin (Tf), a blood protein in Th internalization. Recently, our in vitro study observed that the low concentration of Th nitrate induced proliferation in HepG2 through IGF-1R pathway. This study may have relevance to prevent early effects of Th using IGF-1 receptor-specific inhibitor. One of the major goals of our research group is to develop biological approaches for efficient decorporation of Th from liver. In this direction, liposomal form of DTPA has been optimized to effectively deliver DTPA to the liver. Testing of liposomal-DTPA in Th injected animal showed significant enhancement in removal of Th from liver and blood as compared to non-liposomal DTPA. Using ex-vivo human erythrocytes hemolysis assay and in whole blood condition, further efforts are in-progress to evaluate metal binding molecules in search of more effective decorporating agent than DTPA. In conclusion, this paper would discuss the results on mechanism of biological effects of Th on cells and proteins and newer molecules/approaches for its decorporation for human application

The implications of non-linear biological oscillations on human electrophysiology for electrohypersensitivity (EHS) and multiple chemical sensitivity (MCS).

Science.gov (United States)

Sage, Cindy

2015-01-01

The 'informational content' of Earth's electromagnetic signaling is like a set of operating instructions for human life. These environmental cues are dynamic and involve exquisitely low inputs (intensities) of critical frequencies with which all life on Earth evolved. Circadian and other temporal biological rhythms depend on these fluctuating electromagnetic inputs to direct gene expression, cell communication and metabolism, neural development, brainwave activity, neural synchrony, a diversity of immune functions, sleep and wake cycles, behavior and cognition. Oscillation is also a universal phenomenon, and biological systems of the heart, brain and gut are dependent on the cooperative actions of cells that function according to principles of non-linear, coupled biological oscillations for their synchrony. They are dependent on exquisitely timed cues from the environment at vanishingly small levels. Altered 'informational content' of environmental cues can swamp natural electromagnetic cues and result in dysregulation of normal biological rhythms that direct growth, development, metabolism and repair mechanisms. Pulsed electromagnetic fields (PEMF) and radiofrequency radiation (RFR) can have the devastating biological effects of disrupting homeostasis and desynchronizing normal biological rhythms that maintain health. Non-linear, weak field biological oscillations govern body electrophysiology, organize cell and tissue functions and maintain organ systems. Artificial bioelectrical interference can give false information (disruptive signaling) sufficient to affect critical pacemaker cells (of the heart, gut and brain) and desynchronize functions of these important cells that orchestrate function and maintain health. Chronic physiological stress undermines homeostasis whether it is chemically induced or electromagnetically induced (or both exposures are simultaneous contributors). This can eventually break down adaptive biological responses critical to health

Direct electron transfer based enzymatic fuel cells

International Nuclear Information System (INIS)

Falk, Magnus; Blum, Zoltan; Shleev, Sergey

2012-01-01

In this mini-review we briefly describe some historical developments made in the field of enzymatic fuel cells (FCs), discussing important design considerations taken when constructing mediator-, cofactor-, and membrane-less biological FCs (BFCs). Since the topic is rather extensive, only BFCs utilizing direct electron transfer (DET) reactions on both the anodic and cathodic sides are considered. Moreover, the performance of mostly glucose/oxygen biodevices is analyzed and compared. We also present some unpublished results on mediator-, cofactor-, and membrane-less glucose/oxygen BFCs recently designed in our group and tested in different human physiological fluids, such as blood, plasma, saliva, and tears. Finally, further perspectives for BFC applications are highlighted.

Medical significance of the essential biological metals

International Nuclear Information System (INIS)

Davies, I.J.T.

1977-01-01

The medical significance of the essential biological metals such as zinc, copper and molybdenum as well as their nutritional and biochemical importance are reviewed. The following topics are treated: biochemical actions of the essential biological metals; the concept of essentiality; the development of knowledge about the essential biological metals. Data are given on zinc deficiency and hypogonadismi in humans, zinc and acrodermatitis enterophatica, zinc and the skin, zinc in diabetes mellitus, zinc and insulin, zinc and the liver; copper functions, copper deficiency - ''sway back'' in sheep, copper and haemopoiesis, copper and the function of blood vessels; molybdenum and dental caries in humans, oesophageal carcinoma and molybdenum deficiency in humans. (T.G.)

Quantitative secondary electron detection

Science.gov (United States)

Agrawal, Jyoti; Joy, David C.; Nayak, Subuhadarshi

2018-05-08

Quantitative Secondary Electron Detection (QSED) using the array of solid state devices (SSD) based electron-counters enable critical dimension metrology measurements in materials such as semiconductors, nanomaterials, and biological samples (FIG. 3). Methods and devices effect a quantitative detection of secondary electrons with the array of solid state detectors comprising a number of solid state detectors. An array senses the number of secondary electrons with a plurality of solid state detectors, counting the number of secondary electrons with a time to digital converter circuit in counter mode.

Characterising the Development of the Understanding of Human Body Systems in High-School Biology Students--A Longitudinal Study

Science.gov (United States)

Snapir, Zohar; Eberbach, Catherine; Ben-Zvi-Assaraf, Orit; Hmelo-Silver, Cindy; Tripto, Jaklin

2017-01-01

Science education today has become increasingly focused on research into complex natural, social and technological systems. In this study, we examined the development of high-school biology students' systems understanding of the human body, in a three-year longitudinal study. The development of the students' system understanding was evaluated…

Applicability of Computational Systems Biology in Toxicology

DEFF Research Database (Denmark)

Kongsbak, Kristine Grønning; Hadrup, Niels; Audouze, Karine Marie Laure

2014-01-01

be used to establish hypotheses on links between the chemical and human diseases. Such information can also be applied for designing more intelligent animal/cell experiments that can test the established hypotheses. Here, we describe how and why to apply an integrative systems biology method......Systems biology as a research field has emerged within the last few decades. Systems biology, often defined as the antithesis of the reductionist approach, integrates information about individual components of a biological system. In integrative systems biology, large data sets from various sources...... and databases are used to model and predict effects of chemicals on, for instance, human health. In toxicology, computational systems biology enables identification of important pathways and molecules from large data sets; tasks that can be extremely laborious when performed by a classical literature search...

Secondary mineralization in carious lesions of human dentin. Electron-probe, electron microscope, and electron diffraction studies

Energy Technology Data Exchange (ETDEWEB)

Ogiwara, H [Tokyo Dental Coll. (Japan)

1975-02-01

Dentinal carious lesions having a remineralized surface layer were studied by means electron-probe microanalysis, electron microscopy, electron diffraction. As the results of electron-probe study, F, Mg, and Na were found to be distributed mainly in the remineralized surface layer and S in the decalcified region where decreases in Ca, P, and Mg concentration were usually observed. The decrease in Mg concentration always started earlier than that of Ca and P concentration. Electron microscope and electron diffraction studies revealed that apatic crystals in the remineralized surface layer were much larger than those in the intact dentin. Although they were less conspicuous, crystals in the decalcified region also were larger than those in the intact region. Dentinal tubules, occluded by many crystals, were frequently seen during the observations. Crystals in the tubules varied in morphology, showing granular, needle, rhomboid, and tabular shapes. By means of electron diffraction, the granular- or needle-shaped crystals were identified as apatite and the rhomboid-shaped crystals as whitlockite. Some of the tabular-shaped crystals appeared to be cotacalcium phosphate.

Skin electronics from scalable fabrication of an intrinsically stretchable transistor array.

Science.gov (United States)

Wang, Sihong; Xu, Jie; Wang, Weichen; Wang, Ging-Ji Nathan; Rastak, Reza; Molina-Lopez, Francisco; Chung, Jong Won; Niu, Simiao; Feig, Vivian R; Lopez, Jeffery; Lei, Ting; Kwon, Soon-Ki; Kim, Yeongin; Foudeh, Amir M; Ehrlich, Anatol; Gasperini, Andrea; Yun, Youngjun; Murmann, Boris; Tok, Jeffery B-H; Bao, Zhenan

2018-03-01

Skin-like electronics that can adhere seamlessly to human skin or within the body are highly desirable for applications such as health monitoring, medical treatment, medical implants and biological studies, and for technologies that include human-machine interfaces, soft robotics and augmented reality. Rendering such electronics soft and stretchable-like human skin-would make them more comfortable to wear, and, through increased contact area, would greatly enhance the fidelity of signals acquired from the skin. Structural engineering of rigid inorganic and organic devices has enabled circuit-level stretchability, but this requires sophisticated fabrication techniques and usually suffers from reduced densities of devices within an array. We reasoned that the desired parameters, such as higher mechanical deformability and robustness, improved skin compatibility and higher device density, could be provided by using intrinsically stretchable polymer materials instead. However, the production of intrinsically stretchable materials and devices is still largely in its infancy: such materials have been reported, but functional, intrinsically stretchable electronics have yet to be demonstrated owing to the lack of a scalable fabrication technology. Here we describe a fabrication process that enables high yield and uniformity from a variety of intrinsically stretchable electronic polymers. We demonstrate an intrinsically stretchable polymer transistor array with an unprecedented device density of 347 transistors per square centimetre. The transistors have an average charge-carrier mobility comparable to that of amorphous silicon, varying only slightly (within one order of magnitude) when subjected to 100 per cent strain for 1,000 cycles, without current-voltage hysteresis. Our transistor arrays thus constitute intrinsically stretchable skin electronics, and include an active matrix for sensory arrays, as well as analogue and digital circuit elements. Our process offers a

Skin electronics from scalable fabrication of an intrinsically stretchable transistor array

Science.gov (United States)

Wang, Sihong; Xu, Jie; Wang, Weichen; Wang, Ging-Ji Nathan; Rastak, Reza; Molina-Lopez, Francisco; Chung, Jong Won; Niu, Simiao; Feig, Vivian R.; Lopez, Jeffery; Lei, Ting; Kwon, Soon-Ki; Kim, Yeongin; Foudeh, Amir M.; Ehrlich, Anatol; Gasperini, Andrea; Yun, Youngjun; Murmann, Boris; Tok, Jeffery B.-H.; Bao, Zhenan

2018-03-01

Skin-like electronics that can adhere seamlessly to human skin or within the body are highly desirable for applications such as health monitoring, medical treatment, medical implants and biological studies, and for technologies that include human-machine interfaces, soft robotics and augmented reality. Rendering such electronics soft and stretchable—like human skin—would make them more comfortable to wear, and, through increased contact area, would greatly enhance the fidelity of signals acquired from the skin. Structural engineering of rigid inorganic and organic devices has enabled circuit-level stretchability, but this requires sophisticated fabrication techniques and usually suffers from reduced densities of devices within an array. We reasoned that the desired parameters, such as higher mechanical deformability and robustness, improved skin compatibility and higher device density, could be provided by using intrinsically stretchable polymer materials instead. However, the production of intrinsically stretchable materials and devices is still largely in its infancy: such materials have been reported, but functional, intrinsically stretchable electronics have yet to be demonstrated owing to the lack of a scalable fabrication technology. Here we describe a fabrication process that enables high yield and uniformity from a variety of intrinsically stretchable electronic polymers. We demonstrate an intrinsically stretchable polymer transistor array with an unprecedented device density of 347 transistors per square centimetre. The transistors have an average charge-carrier mobility comparable to that of amorphous silicon, varying only slightly (within one order of magnitude) when subjected to 100 per cent strain for 1,000 cycles, without current-voltage hysteresis. Our transistor arrays thus constitute intrinsically stretchable skin electronics, and include an active matrix for sensory arrays, as well as analogue and digital circuit elements. Our process offers a

Electron image reconstruction of helical protein assemblies

International Nuclear Information System (INIS)

Cremers, A.F.M.

1980-01-01

The analysis of projections of large ordered biological systems obtained by electron microscopy of negatively stained specimens is described. The biological structures amenable to this approach are constructed from a large number of identical protein molecules, which are arranged according to helical symmetry. Electron images of these structures generally contain sufficient information in order to calculate a three-dimensional density map. (Auth.)

Interaction mechanisms and biological effects of static magnetic fields

Energy Technology Data Exchange (ETDEWEB)

Tenforde, T.S.

1994-06-01

Mechanisms through which static magnetic fields interact with living systems are described and illustrated by selected experimental observations. These mechanisms include electrodynamic interactions with moving, ionic charges (blood flow and nerve impulse conduction), magnetomechanical interactions (orientation and translation of molecules structures and magnetic particles), and interactions with electronic spin states in charge transfer reactions (photo-induced electron transfer in photosynthesis). A general summary is also presented of the biological effects of static magnetic fields. There is convincing experimental evidence for magnetoreception mechanisms in several classes of lower organisms, including bacteria and marine organisms. However, in more highly evolved species of animals, there is no evidence that the interactions of static magnetic fields with flux densities up to 2 Tesla (1 Tesla [T] = 10{sup 4} Gauss) produce either behavioral or physiolocical alterations. These results, based on controlled studies with laboratory animals, are consistent with the outcome of recent epidemiological surveys on human populations exposed occupationally to static magnetic fields.

Synthetic Plasma Liquid Based Electronic Circuits Realization-A Novel Concept.

Science.gov (United States)

Pandya, Killol V; Kosta, ShivPrasad

2016-09-01

Biomedical research is contributing significant role in the field of biomedical engineering and applied science. It brings research and innovations to a different level. This study investigated artificial human blood -synthetic plasma liquid as conductive medium. Keeping in mind the conductivity of synthetic plasma, astable multivibrator as well as differential amplifier circuit were demonstrated. The circuits were given normal input voltages at regular temperature and ideal conditions. The result shows desired response which supports the novel concept. For both the circuits, phase shift of 180° achieved by analysing biological electronic circuits.

An in vivo model to assess magnesium alloys and their biological effect on human bone marrow stromal cells.

Science.gov (United States)

Yoshizawa, Sayuri; Chaya, Amy; Verdelis, Kostas; Bilodeau, Elizabeth A; Sfeir, Charles

2015-12-01

Magnesium (Mg) alloys have many unique qualities which make them ideal candidates for bone fixation devices, including biocompatibility and degradation in vivo. Despite a rise in Mg alloy production and research, there remains no standardized system to assess their degradation or biological effect on human stem cells in vivo. In this study, we developed a novel in vivo model to assess Mg alloys for craniofacial and orthopedic applications. Our model consists of a collagen sponge seeded with human bone marrow stromal cells (hBMSCs) around a central Mg alloy rod. These scaffolds were implanted subcutaneously in mice and analyzed after eight weeks. Alloy degradation and biological effect were determined by microcomputed tomography (microCT), histological staining, and immunohistochemistry (IHC). MicroCT showed greater volume loss for pure Mg compared to AZ31 after eight weeks in vivo. Histological analysis showed that hBMSCs were retained around the Mg implants after 8 weeks. Furthermore, immunohistochemistry showed the expression of dentin matrix protein 1 and osteopontin around both pure Mg and AZ31 with implanted hBMSCs. In addition, histological sections showed a thin mineral layer around all degrading alloys at the alloy-tissue interface. In conclusion, our data show that degrading pure Mg and AZ31 implants are cytocompatible and do not inhibit the osteogenic property of hBMSCs in vivo. These results demonstrate that this model can be used to efficiently assess the biological effect of corroding Mg alloys in vivo. Importantly, this model may be modified to accommodate additional cell types and clinical applications. Magnesium (Mg) alloys have been investigated as ideal candidates for bone fixation devices due to high biocompatibility and degradation in vivo, and there is a growing need of establishing an efficient in vivo material screening system. In this study, we assessed degradation rate and biological effect of Mg alloys by transplanting Mg alloy rod with

Do-it-yourself biology and electronic waste hacking: A politics of demonstration in precarious times.

Science.gov (United States)

Delgado, Ana; Callén, Blanca

2017-02-01

In recent years, there has been an explosion of do it yourself, maker and hacker spaces in Europe. Through makers and do-it-yourself initiatives, 'hacking' is moving into the everyday life of citizens. This article explores the collective and political nature of those hacks by reporting on empirical work on electronic waste and do-it-yourself biology hacking. Using Dewey's experimental approach to politics, we analyse hacks as 'inquiry' to see how they serve to articulate public and political action. We argue that do-it-yourself and makers' hacks are technical and political demonstrations. What do-it-yourself and makers' hacks ultimately demonstrate is that things can be done otherwise and that 'you' can also do it. In this sense, they have a potential viral effect. The final part of the article explores some potential shortcomings of such politics of demonstration.

Drivers of extinction risk in African mammals: the interplay of distribution state, human pressure, conservation response and species biology.

Science.gov (United States)

Di Marco, Moreno; Buchanan, Graeme M; Szantoi, Zoltan; Holmgren, Milena; Grottolo Marasini, Gabriele; Gross, Dorit; Tranquilli, Sandra; Boitani, Luigi; Rondinini, Carlo

2014-01-01

Although conservation intervention has reversed the decline of some species, our success is outweighed by a much larger number of species moving towards extinction. Extinction risk modelling can identify correlates of risk and species not yet recognized to be threatened. Here, we use machine learning models to identify correlates of extinction risk in African terrestrial mammals using a set of variables belonging to four classes: species distribution state, human pressures, conservation response and species biology. We derived information on distribution state and human pressure from satellite-borne imagery. Variables in all four classes were identified as important predictors of extinction risk, and interactions were observed among variables in different classes (e.g. level of protection, human threats, species distribution ranges). Species biology had a key role in mediating the effect of external variables. The model was 90% accurate in classifying extinction risk status of species, but in a few cases the observed and modelled extinction risk mismatched. Species in this condition might suffer from an incorrect classification of extinction risk (hence require reassessment). An increased availability of satellite imagery combined with improved resolution and classification accuracy of the resulting maps will play a progressively greater role in conservation monitoring.

Electronic human resource management: Enhancing or entrancing?

Directory of Open Access Journals (Sweden)

Paul Poisat

2017-07-01

Full Text Available Orientation: This article provides an investigation into the current level of development of the body of knowledge related to electronic human resource management (e-HRM by means of a qualitative content analysis. Several aspects of e-HRM, namely definitions of e-HRM, the theoretical perspectives around e-HRM, the role of e-HRM, the various types of e-HRM and the requirements for successful e-HRM, are examined. Research purpose: The purpose of the article was to determine the status of e-HRM and examine the studies that report on the link between e-HRM and organisational productivity. Motivation for the study: e-HRM has the capacity to improve organisational efficiency and leverage the role of human resources (HR as a strategic business partner. Main findings: The notion that the implementation of e-HRM will lead to improved organisational productivity is commonly assumed; however, empirical evidence in this regard was found to be limited. Practical/managerial implications: From the results of this investigation it is evident that more research is required to gain a greater understanding of the influence of e-HRM on organisational productivity, as well as to develop measures for assessing this influence. Contribution: This article proposes additional areas to research and measure when investigating the effectiveness of e-HRM. It provides a different lens from which to view e-HRM assessment whilst keeping it within recognised HR measurement parameters (the HR value chain. In addition, it not only provides areas for measuring e-HRM’s influence but also provides important clues as to how the measurements may be approached.

Biologically Produced Methane as a Renewable Energy Source.

Science.gov (United States)

Holmes, D E; Smith, J A

2016-01-01

Methanogens are a unique group of strictly anaerobic archaea that are more metabolically diverse than previously thought. Traditionally, it was thought that methanogens could only generate methane by coupling the oxidation of products formed by fermentative bacteria with the reduction of CO 2 . However, it has recently been observed that many methanogens can also use electrons extruded from metal-respiring bacteria, biocathodes, or insoluble electron shuttles as energy sources. Methanogens are found in both human-made and natural environments and are responsible for the production of ∼71% of the global atmospheric methane. Their habitats range from the human digestive tract to hydrothermal vents. Although biologically produced methane can negatively impact the environment if released into the atmosphere, when captured, it can serve as a potent fuel source. The anaerobic digestion of wastes such as animal manure, human sewage, or food waste produces biogas which is composed of ∼60% methane. Methane from biogas can be cleaned to yield purified methane (biomethane) that can be readily incorporated into natural gas pipelines making it a promising renewable energy source. Conventional anaerobic digestion is limited by long retention times, low organics removal efficiencies, and low biogas production rates. Therefore, many studies are being conducted to improve the anaerobic digestion process. Researchers have found that addition of conductive materials and/or electrically active cathodes to anaerobic digesters can stimulate the digestion process and increase methane content of biogas. It is hoped that optimization of anaerobic digesters will make biogas more readily accessible to the average person. Copyright © 2016 Elsevier Inc. All rights reserved.

Leptospira interrogans causes quantitative and morphological disturbances in adherens junctions and other biological groups of proteins in human endothelial cells

Science.gov (United States)

Sato, Hiromi

2017-01-01

Pathogenic Leptospira transmits from animals to humans, causing the zoonotic life-threatening infection called leptospirosis. This infection is reported worldwide with higher risk in tropical regions. Symptoms of leptospirosis range from mild illness to severe illness such as liver damage, kidney failure, respiratory distress, meningitis, and fatal hemorrhagic disease. Invasive species of Leptospira rapidly disseminate to multiple tissues where this bacterium damages host endothelial cells, increasing vascular permeability. Despite the burden in humans and animals, the pathogenic mechanisms of Leptospira infection remain to be elucidated. The pathogenic leptospires adhere to endothelial cells and permeabilize endothelial barriers in vivo and in vitro. In this study, human endothelial cells were infected with the pathogenic L. interrogans serovar Copenhageni or the saprophyte L. biflexa serovar Patoc to investigate morphological changes and other distinctive phenotypes of host cell proteins by fluorescence microscopy. Among those analyzed, 17 proteins from five biological classes demonstrated distinctive phenotypes in morphology and/or signal intensity upon infection with Leptospira. The affected biological groups include: 1) extracellular matrix, 2) intercellular adhesion molecules and cell surface receptors, 3) intracellular proteins, 4) cell-cell junction proteins, and 5) a cytoskeletal protein. Infection with the pathogenic strain most profoundly disturbed the biological structures of adherens junctions (VE-cadherin and catenins) and actin filaments. Our data illuminate morphological disruptions and reduced signals of cell-cell junction proteins and filamentous actin in L. interrogans-infected endothelial cells. In addition, Leptospira infection, regardless of pathogenic status, influenced other host proteins belonging to multiple biological classes. Our data suggest that this zoonotic agent may damage endothelial cells via multiple cascades or pathways

Leptospira interrogans causes quantitative and morphological disturbances in adherens junctions and other biological groups of proteins in human endothelial cells.

Science.gov (United States)

Sato, Hiromi; Coburn, Jenifer

2017-07-01

Pathogenic Leptospira transmits from animals to humans, causing the zoonotic life-threatening infection called leptospirosis. This infection is reported worldwide with higher risk in tropical regions. Symptoms of leptospirosis range from mild illness to severe illness such as liver damage, kidney failure, respiratory distress, meningitis, and fatal hemorrhagic disease. Invasive species of Leptospira rapidly disseminate to multiple tissues where this bacterium damages host endothelial cells, increasing vascular permeability. Despite the burden in humans and animals, the pathogenic mechanisms of Leptospira infection remain to be elucidated. The pathogenic leptospires adhere to endothelial cells and permeabilize endothelial barriers in vivo and in vitro. In this study, human endothelial cells were infected with the pathogenic L. interrogans serovar Copenhageni or the saprophyte L. biflexa serovar Patoc to investigate morphological changes and other distinctive phenotypes of host cell proteins by fluorescence microscopy. Among those analyzed, 17 proteins from five biological classes demonstrated distinctive phenotypes in morphology and/or signal intensity upon infection with Leptospira. The affected biological groups include: 1) extracellular matrix, 2) intercellular adhesion molecules and cell surface receptors, 3) intracellular proteins, 4) cell-cell junction proteins, and 5) a cytoskeletal protein. Infection with the pathogenic strain most profoundly disturbed the biological structures of adherens junctions (VE-cadherin and catenins) and actin filaments. Our data illuminate morphological disruptions and reduced signals of cell-cell junction proteins and filamentous actin in L. interrogans-infected endothelial cells. In addition, Leptospira infection, regardless of pathogenic status, influenced other host proteins belonging to multiple biological classes. Our data suggest that this zoonotic agent may damage endothelial cells via multiple cascades or pathways

Leptospira interrogans causes quantitative and morphological disturbances in adherens junctions and other biological groups of proteins in human endothelial cells.

Directory of Open Access Journals (Sweden)

Hiromi Sato

2017-07-01

Full Text Available Pathogenic Leptospira transmits from animals to humans, causing the zoonotic life-threatening infection called leptospirosis. This infection is reported worldwide with higher risk in tropical regions. Symptoms of leptospirosis range from mild illness to severe illness such as liver damage, kidney failure, respiratory distress, meningitis, and fatal hemorrhagic disease. Invasive species of Leptospira rapidly disseminate to multiple tissues where this bacterium damages host endothelial cells, increasing vascular permeability. Despite the burden in humans and animals, the pathogenic mechanisms of Leptospira infection remain to be elucidated. The pathogenic leptospires adhere to endothelial cells and permeabilize endothelial barriers in vivo and in vitro. In this study, human endothelial cells were infected with the pathogenic L. interrogans serovar Copenhageni or the saprophyte L. biflexa serovar Patoc to investigate morphological changes and other distinctive phenotypes of host cell proteins by fluorescence microscopy. Among those analyzed, 17 proteins from five biological classes demonstrated distinctive phenotypes in morphology and/or signal intensity upon infection with Leptospira. The affected biological groups include: 1 extracellular matrix, 2 intercellular adhesion molecules and cell surface receptors, 3 intracellular proteins, 4 cell-cell junction proteins, and 5 a cytoskeletal protein. Infection with the pathogenic strain most profoundly disturbed the biological structures of adherens junctions (VE-cadherin and catenins and actin filaments. Our data illuminate morphological disruptions and reduced signals of cell-cell junction proteins and filamentous actin in L. interrogans-infected endothelial cells. In addition, Leptospira infection, regardless of pathogenic status, influenced other host proteins belonging to multiple biological classes. Our data suggest that this zoonotic agent may damage endothelial cells via multiple cascades or

Molecular cloning and biological characterization of the human excision repair gene ERCC-3

International Nuclear Information System (INIS)

Weeda, G.; van Ham, R.C.; Masurel, R.; Westerveld, A.; Odijk, H.; de Wit, J.; Bootsma, D.; van der Eb, A.J.; Hoeijmakers, J.H.

1990-01-01

In this report we present the cloning, partial characterization, and preliminary studies of the biological activity of a human gene, designated ERCC-3, involved in early steps of the nucleotide excision repair pathway. The gene was cloned after genomic DNA transfection of human (HeLa) chromosomal DNA together with dominant marker pSV3gptH to the UV-sensitive, incision-defective Chinese hamster ovary (CHO) mutant 27-1. This mutant belongs to complementation group 3 of repair-deficient rodent mutants. After selection of UV-resistant primary and secondary 27-1 transformants, human sequences associated with the induced UV resistance were rescued in cosmids from the DNA of a secondary transformant by using a linked dominant marker copy and human repetitive DNA as probes. From coinheritance analysis of the ERCC-3 region in independent transformants, we deduce that the gene has a size of 35 to 45 kilobases, of which one essential segment has so far been refractory to cloning. Conserved unique human sequences hybridizing to a 3.0-kilobase mRNA were used to isolate apparently full-length cDNA clones. Upon transfection to 27-1 cells, the ERCC-3 cDNA, inserted in a mammalian expression vector, induced specific and (virtually) complete correction of the UV sensitivity and unscheduled DNA synthesis of mutants of complementation group 3 with very high efficiency. Mutant 27-1 is, unlike other mutants of complementation group 3, also very sensitive toward small alkylating agents. This unique property of the mutant is not corrected by introduction of the ERCC-3 cDNA, indicating that it may be caused by an independent second mutation in another repair function. By hybridization to DNA of a human x rodent hybrid cell panel, the ERCC-3 gene was assigned to chromosome 2, in agreement with data based on cell fusion

[Human myoblast culture as muscle stem cells in medical and biological studies].

Science.gov (United States)

Terekhov, S M; Krokhina, T B; Shishkin, S S; Krakhmaleva, I N; Zakharov, S F; Ershova, E S

2001-01-01

The method for obtaining human myoblast culture has been modified to consider the specific histological localization of the satellite cells as well as their growth properties; the cultivation conditions have been selected to grow up to 150000 cells/cm2. At high densities, the cells remain mononuclear and preserve their typical myoblast morphology as well as the capacity for fusion and the formation of myotubes. By contrast to fibroblasts, up to 80% of the cells in the myoblast culture were positive in the acid phosphatase test, which indicates their stem nature. The obtained myoblast cultures were used in the clinical tests of cell-mediated gene therapy of Duchenne's muscular dystrophy as well as in the bioassay for the effects of biologically active compounds.

Electron beam treatment of industrial wastewater

International Nuclear Information System (INIS)

Han, Bumsoo; Kim, JinKyu; Kim, Yuri

2004-01-01

For industrial wastewater with low impurity levels such as contaminated ground water, cleaning water and etc., purification only with electron beam is possible, but it should be managed carefully with reducing required irradiation doses as low as possible. Also for industrial wastewater with high impurity levels such as dyeing wastewater, leachate and etc., purification only with electron beam requires high amount of doses and far beyond economies. Electron beam treatment combined with conventional purification methods such as coagulation, biological treatment, etc. is suitable for reduction of non-biodegradable impurities in wastewater and will extend the application area of electron beam. A pilot plant with electron beam for treating 1,000 m 3 /day of wastewater from dyeing industries has constructed and operated continuously since Oct 1998. Electron beam irradiation instead of chemical treatment shows much improvement in removing impurities and increases the efficiency of biological treatment. Actual plant is under consideration based upon the experimental results. (author)

Integration of systems biology with organs-on-chips to humanize therapeutic development

Science.gov (United States)

Edington, Collin D.; Cirit, Murat; Chen, Wen Li Kelly; Clark, Amanda M.; Wells, Alan; Trumper, David L.; Griffith, Linda G.

2017-02-01

"Mice are not little people" - a refrain becoming louder as the gaps between animal models and human disease become more apparent. At the same time, three emerging approaches are headed toward integration: powerful systems biology analysis of cell-cell and intracellular signaling networks in patient-derived samples; 3D tissue engineered models of human organ systems, often made from stem cells; and micro-fluidic and meso-fluidic devices that enable living systems to be sustained, perturbed and analyzed for weeks in culture. Integration of these rapidly moving fields has the potential to revolutionize development of therapeutics for complex, chronic diseases, including those that have weak genetic bases and substantial contributions from gene-environment interactions. Technical challenges in modeling complex diseases with "organs on chips" approaches include the need for relatively large tissue masses and organ-organ cross talk to capture systemic effects, such that current microfluidic formats often fail to capture the required scale and complexity for interconnected systems. These constraints drive development of new strategies for designing in vitro models, including perfusing organ models, as well as "mesofluidic" pumping and circulation in platforms connecting several organ systems, to achieve the appropriate physiological relevance.

EPR Characterization of Dinitrosyl Iron Complexes with Thiol-Containing Ligands as an Approach to Their Identification in Biological Objects: An Overview.

Science.gov (United States)

Vanin, Anatoly F

2018-06-01

The overview demonstrates how the use of only one physico-chemical approach, viz., the electron paramagnetic resonance method, allowed detection and identification of dinitrosyl iron complexes with thiol-containing ligands in various animal and bacterial cells. These complexes are formed in biological objects in the paramagnetic (electron paramagnetic resonance-active) mononuclear and diamagnetic (electron paramagnetic resonance-silent) binuclear forms and control the activity of nitrogen monoxide, one of the most universal regulators of metabolic processes in the organism. The analysis of electronic and spatial structures of dinitrosyl iron complex sheds additional light on the mechanism whereby dinitrosyl iron complex with thiol-containing ligands function in human and animal cells as donors of nitrogen monoxide and its ionized form, viz., nitrosonium ions (NO + ).

The Human Proteome Organization Chromosome 6 Consortium: integrating chromosome-centric and biology/disease driven strategies.

Science.gov (United States)

Borchers, C H; Kast, J; Foster, L J; Siu, K W M; Overall, C M; Binkowski, T A; Hildebrand, W H; Scherer, A; Mansoor, M; Keown, P A

2014-04-04

The Human Proteome Project (HPP) is designed to generate a comprehensive map of the protein-based molecular architecture of the human body, to provide a resource to help elucidate biological and molecular function, and to advance diagnosis and treatment of diseases. Within this framework, the chromosome-based HPP (C-HPP) has allocated responsibility for mapping individual chromosomes by country or region, while the biology/disease HPP (B/D-HPP) coordinates these teams in cross-functional disease-based groups. Chromosome 6 (Ch6) provides an excellent model for integration of these two tasks. This metacentric chromosome has a complement of 1002-1034 genes that code for known, novel or putative proteins. Ch6 is functionally associated with more than 120 major human diseases, many with high population prevalence, devastating clinical impact and profound societal consequences. The unique combination of genomic, proteomic, metabolomic, phenomic and health services data being drawn together within the Ch6 program has enormous potential to advance personalized medicine by promoting robust biomarkers, subunit vaccines and new drug targets. The strong liaison between the clinical and laboratory teams, and the structured framework for technology transfer and health policy decisions within Canada will increase the speed and efficacy of this transition, and the value of this translational research. Canada has been selected to play a leading role in the international Human Proteome Project, the global counterpart of the Human Genome Project designed to understand the structure and function of the human proteome in health and disease. Canada will lead an international team focusing on chromosome 6, which is functionally associated with more than 120 major human diseases, including immune and inflammatory disorders affecting the brain, skeletal system, heart and blood vessels, lungs, kidney, liver, gastrointestinal tract and endocrine system. Many of these chronic and persistent

Biology-inspired AMO physics

Science.gov (United States)

Mathur, Deepak

2015-01-01

This Topical Review presents an overview of increasingly robust interconnects that are being established between atomic, molecular and optical (AMO) physics and the life sciences. AMO physics, outgrowing its historical role as a facilitator—a provider of optical methodologies, for instance—now seeks to partner biology in its quest to link systems-level descriptions of biological entities to insights based on molecular processes. Of course, perspectives differ when AMO physicists and biologists consider various processes. For instance, while AMO physicists link molecular properties and dynamics to potential energy surfaces, these have to give way to energy landscapes in considerations of protein dynamics. But there are similarities also: tunnelling and non-adiabatic transitions occur both in protein dynamics and in molecular dynamics. We bring to the fore some such differences and similarities; we consider imaging techniques based on AMO concepts, like 4D fluorescence microscopy which allows access to the dynamics of cellular processes, multiphoton microscopy which offers a built-in confocality, and microscopy with femtosecond laser beams to saturate the suppression of fluorescence in spatially controlled fashion so as to circumvent the diffraction limit. Beyond imaging, AMO physics contributes with optical traps that probe the mechanical and dynamical properties of single ‘live’ cells, highlighting differences between healthy and diseased cells. Trap methodologies have also begun to probe the dynamics governing of neural stem cells adhering to each other to form neurospheres and, with squeezed light to probe sub-diffusive motion of yeast cells. Strong field science contributes not only by providing a source of energetic electrons and γ-rays via laser-plasma accelerations schemes, but also via filamentation and supercontinuum generation, enabling mainstream collision physics into play in diverse processes like DNA damage induced by low-energy collisions to

Granulocyte macrophage colony stimulating factor (GM-CSF biological actions on human dermal fibroblasts

Directory of Open Access Journals (Sweden)

S Montagnani

2009-12-01

Full Text Available Fibroblasts are involved in all pathologies characterized by increased ExtraCellularMatrix synthesis, from wound healing to fibrosis. Granulocyte Macrophage-Colony Stimulating Factor (GM-CSF is a cytokine isolated as an hemopoietic growth factor but recently indicated as a differentiative agent on endothelial cells. In this work we demonstrated the expression of the receptor for GM-CSF (GMCSFR on human normal skin fibroblasts from healthy subjects (NFPC and on a human normal fibroblast cell line (NHDF and we try to investigate the biological effects of this cytokine. Human normal fibroblasts were cultured with different doses of GM-CSF to study the effects of this factor on GMCSFR expression, on cell proliferation and adhesion structures. In addition we studied the production of some Extra-Cellular Matrix (ECM components such as Fibronectin, Tenascin and Collagen I. The growth rate of fibroblasts from healthy donors (NFPC is not augmented by GM-CSF stimulation in spite of increased expression of the GM-CSFR. On the contrary, the proliferation of normal human dermal fibroblasts (NHDF cell line seems more influenced by high concentration of GM-CSF in the culture medium. The adhesion structures and the ECM components appear variously influenced by GM-CSF treatment as compared to fibroblasts cultured in basal condition, but newly only NHDF cells are really induced to increase their synthesis activity. We suggest that the in vitro treatment with GM-CSF can shift human normal fibroblasts towards a more differentiated state, due or accompanied by an increased expression of GM-CSFR and that such “differentiation” is an important event induced by such cytokine.

The biological effects of quadripolar radiofrequency sequential application: a human experimental study.

Science.gov (United States)

Nicoletti, Giovanni; Cornaglia, Antonia Icaro; Faga, Angela; Scevola, Silvia

2014-10-01

An experimental study was conducted to assess the effectiveness and safety of an innovative quadripolar variable electrode configuration radiofrequency device with objective measurements in an ex vivo and in vivo human experimental model. Nonablative radiofrequency applications are well-established anti-ageing procedures for cosmetic skin tightening. The study was performed in two steps: ex vivo and in vivo assessments. In the ex vivo assessments the radiofrequency applications were performed on human full-thickness skin and subcutaneous tissue specimens harvested during surgery for body contouring. In the in vivo assessments the applications were performed on two volunteer patients scheduled for body contouring surgery at the end of the study. The assessment methods were: clinical examination and medical photography, temperature measurement with thermal imaging scan, and light microscopy histological examination. The ex vivo assessments allowed for identification of the effective safety range for human application. The in vivo assessments allowed for demonstration of the biological effects of sequential radiofrequency applications. After a course of radiofrequency applications, the collagen fibers underwent an immediate heat-induced rearrangement and were partially denaturated and progressively metabolized by the macrophages. An overall thickening and spatial rearrangement was appreciated both in the collagen and elastic fibers, the latter displaying a juvenile reticular pattern. A late onset in the macrophage activation after sequential radiofrequency applications was appreciated. Our data confirm the effectiveness of sequential radiofrequency applications in obtaining attenuation of the skin wrinkles by an overall skin tightening.

Seven-day human biological rhythms: An expedition in search of their origin, synchronization, functional advantage, adaptive value and clinical relevance.

Science.gov (United States)

Reinberg, Alain E; Dejardin, Laurence; Smolensky, Michael H; Touitou, Yvan

2017-01-01

This fact-finding expedition explores the perspectives and knowledge of the origin and functional relevance of the 7 d domain of the biological time structure, with special reference to human beings. These biological rhythms are displayed at various levels of organization in diverse species - from the unicellular sea algae of Acetabularia and Goniaulax to plants, insects, fish, birds and mammals, including man - under natural as well as artificial, i.e. constant, environmental conditions. Nonetheless, very little is known about their derivation, functional advantage, adaptive value, synchronization and potential clinical relevance. About 7 d cosmic cycles are seemingly too weak, and the 6 d work/1 d rest week commanded from G-d through the Laws of Mosses to the Hebrews is too recent an event to be the origin in humans. Moreover, human and insect studies conducted under controlled constant conditions devoid of environmental, social and other time cues report the persistence of 7 d rhythms, but with a slightly different (free-running) period (τ), indicating their source is endogenous. Yet, a series of human and laboratory rodent studies reveal certain mainly non-cyclic exogenous events can trigger 7 d rhythm-like phenomena. However, it is unknown whether such triggers unmask, amplify and/or synchronize previous non-overtly expressed oscillations. Circadian (~24 h), circa-monthly (~30 d) and circannual (~1 y) rhythms are viewed as genetically based features of life forms that during evolution conferred significant functional advantage to individual organisms and survival value to species. No such advantages are apparent for endogenous 7 d rhythms, raising several questions: What is the significance of the 7 d activity/rest cycle, i.e. week, storied in the Book of Genesis and adopted by the Hebrews and thereafter the residents of nearby Mediterranean countries and ultimately the world? Why do humans require 1 d off per 7 d span? Do 7 d rhythms bestow functional

Assessment of uranium and selenium speciation in human and bacterial biological models to probe changes in their structural environment

International Nuclear Information System (INIS)

Avoscan, L.; Milgram, S.; Untereiner, G.; Collins, R.; Khodja, H.; Carriere, M.; Gouget, B.; Coves, J.; Hazemann, J.L.

2009-01-01

This study illustrates the potential of physicochemical techniques to speciate uranium (U) and selenium (Se) in biological samples. Speciation, defined he0re as the study of structural environment, of both toxic elements, was characterized at several levels in biological media and directly in human cells or bacteria once the metal(loid)s were internalized. External speciation that is extracellular speciation in culture media was predicted by thermodynamic equilibrium computer modelling using the JChess software and validated by spectroscopic measurements (XANES and EXAFS). Internal speciation that is intracellular speciation in eukaryotic and prokaryotic cells was studied in vitro with a soil bacterium Cupriavidus metallidurans CH34 and ROS 17/2.8 osteoblasts, human cells responsible for bone formation. XANES, EXAFS, HPLC-ICP-MS and SDS-PAGE coupled to particle induced X-ray emission (PIXE) permitted the identification and quantification of complexes formed with organic or inorganic molecules and/or larger proteins. (orig.)

Assessment of uranium and selenium speciation in human and bacterial biological models to probe changes in their structural environment

Energy Technology Data Exchange (ETDEWEB)

Avoscan, L.; Milgram, S.; Untereiner, G.; Collins, R.; Khodja, H.; Carriere, M.; Gouget, B. [Lab. Pierre Sue, CEA-CNRS UMR 9956, CEA/Saclay, Gif-sur-Yvette (France); Coves, J. [Inst. de Biologie Structurale - J.-P. Ebel, Lab. des Proteines Membranaires, Grenoble (France); Hazemann, J.L. [Lab. de Geophysique Interne et Tectonopbysique, UMR CNRS/Univ. Joseph Fourier, Saint-Martin-D' Heres (France)

2009-07-01

This study illustrates the potential of physicochemical techniques to speciate uranium (U) and selenium (Se) in biological samples. Speciation, defined he0re as the study of structural environment, of both toxic elements, was characterized at several levels in biological media and directly in human cells or bacteria once the metal(loid)s were internalized. External speciation that is extracellular speciation in culture media was predicted by thermodynamic equilibrium computer modelling using the JChess software and validated by spectroscopic measurements (XANES and EXAFS). Internal speciation that is intracellular speciation in eukaryotic and prokaryotic cells was studied in vitro with a soil bacterium Cupriavidus metallidurans CH34 and ROS 17/2.8 osteoblasts, human cells responsible for bone formation. XANES, EXAFS, HPLC-ICP-MS and SDS-PAGE coupled to particle induced X-ray emission (PIXE) permitted the identification and quantification of complexes formed with organic or inorganic molecules and/or larger proteins. (orig.)

Metagenomic Systems Biology of the Human Microbiome

DEFF Research Database (Denmark)

Bonde, Ida

The human microbiome is an integrated part of the human body, outnumbering the human cells by approximately a factor 10. These microorganisms are very important for human health, hence knowledge about this, ”our other genome”, has been growing rapidly in recent years. This is manly due to the adv...

Theoretical study of electron transfer mechanism in biological systems with a QM (MRSCI+DFT)/MM method

Energy Technology Data Exchange (ETDEWEB)

Takada, Toshikazu [Research Program for Computational Science, RIKEN 2-1, Hirosawa, Wako, Saitama 351-0198 (Japan)

2007-07-15

The goal of this project is to understand the charge separation mechanisms in biological systems using the molecular orbital theories. Specially, the charge separation in the photosynthetic reaction center is focused on, since the efficiency in use of the solar energy is extraordinary and the reason for it is still kept unknown. Here, a QM/MM theoretical scheme is employed to take the effects of the surrounding proteins onto the pigments into account. To describe such excited electronic structures, a unified theory by MRSCI and DFT is newly invented. For atoms in the MM space, a new sampling method has also been created, based on the statistical physics. By using these theoretical framework, the excited and positively charged states of the special pair, that is, chlorophyll dimmer are planning to be calculated this year.

Theoretical study of electron transfer mechanism in biological systems with a QM (MRSCI+DFT)/MM method

International Nuclear Information System (INIS)

Takada, Toshikazu

2007-01-01

The goal of this project is to understand the charge separation mechanisms in biological systems using the molecular orbital theories. Specially, the charge separation in the photosynthetic reaction center is focused on, since the efficiency in use of the solar energy is extraordinary and the reason for it is still kept unknown. Here, a QM/MM theoretical scheme is employed to take the effects of the surrounding proteins onto the pigments into account. To describe such excited electronic structures, a unified theory by MRSCI and DFT is newly invented. For atoms in the MM space, a new sampling method has also been created, based on the statistical physics. By using these theoretical framework, the excited and positively charged states of the special pair, that is, chlorophyll dimmer are planning to be calculated this year

Systems-Biology Approaches to Discover Anti-Viral Effectors of the Human Innate Immune Response

Directory of Open Access Journals (Sweden)

Andreas F.R. Sommer

2011-07-01

Full Text Available Virus infections elicit an immediate innate response involving antiviral factors. The activities of some of these factors are, in turn, blocked by viral countermeasures. The ensuing battle between the host and the viruses is crucial for determining whether the virus establishes a foothold and/or induces adaptive immune responses. A comprehensive systems-level understanding of the repertoire of anti-viral effectors in the context of these immediate virus-host responses would provide significant advantages in devising novel strategies to interfere with the initial establishment of infections. Recent efforts to identify cellular factors in a comprehensive and unbiased manner, using genome-wide siRNA screens and other systems biology “omics” methodologies, have revealed several potential anti-viral effectors for viruses like Human immunodeficiency virus type 1 (HIV-1, Hepatitis C virus (HCV, West Nile virus (WNV, and influenza virus. This review describes the discovery of novel viral restriction factors and discusses how the integration of different methods in systems biology can be used to more comprehensively identify the intimate interactions of viruses and the cellular innate resistance.

An experimental electronic model for a neuronal cell

International Nuclear Information System (INIS)

Campos-Cantón, I; Martel-Gallegos, G; Rangel-López, A; Vertiz-Hérnandez, A; Zarazúa, S

2014-01-01

Over the last two decades, the study of information transmission in living beings has acquired great relevance, because it regulates and conducts the functioning of all of the organs in the body. In information transmission pathways, the neuron plays an important role in that it receives, transmits, and processes electrical signals from different parts of the human body; these signals are transmitted as electrical impulses called action potentials, and they transmit information from one neuron to another. In this work, and with the aim of developing experiments for teaching biological processes, we implemented an electronic circuit of the neuron cell device and its mathematical model based on piecewise linear functions. (paper)

Heuristic Strategies in Systems Biology

Directory of Open Access Journals (Sweden)

Fridolin Gross

2016-06-01

Full Text Available Systems biology is sometimes presented as providing a superior approach to the problem of biological complexity. Its use of ‘unbiased’ methods and formal quantitative tools might lead to the impression that the human factor is effectively eliminated. However, a closer look reveals that this impression is misguided. Systems biologists cannot simply assemble molecular information and compute biological behavior. Instead, systems biology’s main contribution is to accelerate the discovery of mechanisms by applying models as heuristic tools. These models rely on a variety of idealizing and simplifying assumptions in order to be efficient for this purpose. The strategies of systems biologists are similar to those of experimentalists in that they attempt to reduce the complexity of the discovery process. Analyzing and comparing these strategies, or ‘heuristics’, reveals the importance of the human factor in computational approaches and helps to situate systems biology within the epistemic landscape of the life sciences.

Determining environmental causes of biological effects: the need for a mechanistic physiological dimension in conservation biology.

Science.gov (United States)

Seebacher, Frank; Franklin, Craig E

2012-06-19

The emerging field of Conservation Physiology links environmental change and ecological success by the application of physiological theory, approaches and tools to elucidate and address conservation problems. Human activity has changed the natural environment to a point where the viability of many ecosystems is now under threat. There are already many descriptions of how changes in biological patterns are correlated with environmental changes. The next important step is to determine the causative relationship between environmental variability and biological systems. Physiology provides the mechanistic link between environmental change and ecological patterns. Physiological research, therefore, should be integrated into conservation to predict the biological consequences of human activity, and to identify those species or populations that are most vulnerable.

Critical assessment of the performance of electronic moisture analyzers for small amounts of environmental samples and biological reference materials.

Science.gov (United States)

Krachler, M

2001-12-01

Two electronic moisture analyzers were critically evaluated with regard to their suitability for determining moisture in small amounts (environmental matrices such as leaves, needles, soil, peat, sediments, and sewage sludge, as well as various biological reference materials. To this end, several homogeneous bulk materials were prepared which were subsequently employed for the development and optimization of all analytical procedures. The key features of the moisture analyzers included a halogen or ceramic heater and an integrated balance with a resolution of 0.1 mg, which is an essential prerequisite for obtaining precise results. Oven drying of the bulk materials in a conventional oven at 105 degrees C until constant mass served as reference method. A heating temperature of 65degrees C was found to provide accurate and precise results for almost all matrices investigated. To further improve the accuracy and precision, other critical parameters such as handling of sample pans, standby temperature, and measurement delay were optimized. Because of its ponderous heating behavior, the performance of the ceramic radiator was inferior to that of the halogen heater, which produced moisture results comparable to those obtained by oven drying. The developed drying procedures were successfully applied to the fast moisture analysis (1.4-6.3 min) of certified biological reference materials of similar provenance to the investigated the bulk materials. Moisture results for 200 mg aliquots ranged from 1.4 to 7.8% and good agreement was obtained between the recommended drying procedure for the reference materials and the electronic moisture analyzers with absolute uncertainties amounting to 0.1% and 0.2-0.3%, respectively.

Enhanced Electron-Phonon Coupling at Metal Surfaces

Energy Technology Data Exchange (ETDEWEB)

Plummer, Ward E.

2010-08-04

The Born-Oppenheimer approximation (BOA) decouples electronic from nuclear motion, providing a focal point for most quantum mechanics textbooks. However, a multitude of important chemical, physical and biological phenomena are driven by violations of this approximation. Vibronic interactions are a necessary ingredient in any process that makes or breaks a covalent bond, for example, conventional catalysis or enzymatically delivered biological reactions. Metastable phenomena associated with defects and dopants in semiconductors, oxides, and glasses entail violation of the BOA. Charge exchange in inorganic polymers, organic slats and biological systems involves charge- induced distortions of the local structure. A classic example is conventional superconductivity, which is driven by the electron-lattice interaction. High-resolution angle-resolved photoemission experiments are yielding new insight into the microscopic origin of electron-phonon coupling (EPC) in anisotropic two-dimensional systems. Our recent surface phonon measurement on the surface of a high-Tc material clearly indicates an important momentum dependent EPC in these materials. In the last few years we have shifted our research focus from solely looking at electron phonon coupling to examining the structure/functionality relationship at the surface of complex transition metal compounds. The investigation on electron phonon coupling has allowed us to move to systems where there is coupling between the lattice, the electrons and the spin.

Do-it-yourself biology and electronic waste hacking: A politics of demonstration in precarious times

Science.gov (United States)

Delgado, Ana; Callén, Blanca

2016-01-01

In recent years, there has been an explosion of do it yourself, maker and hacker spaces in Europe. Through makers and do-it-yourself initiatives, ‘hacking’ is moving into the everyday life of citizens. This article explores the collective and political nature of those hacks by reporting on empirical work on electronic waste and do-it-yourself biology hacking. Using Dewey’s experimental approach to politics, we analyse hacks as ‘inquiry’ to see how they serve to articulate public and political action. We argue that do-it-yourself and makers’ hacks are technical and political demonstrations. What do-it-yourself and makers’ hacks ultimately demonstrate is that things can be done otherwise and that ‘you’ can also do it. In this sense, they have a potential viral effect. The final part of the article explores some potential shortcomings of such politics of demonstration. PMID:27233296

Quantitating morphological changes in biological samples during scanning electron microscopy sample preparation with correlative super-resolution microscopy.

Science.gov (United States)

Zhang, Ying; Huang, Tao; Jorgens, Danielle M; Nickerson, Andrew; Lin, Li-Jung; Pelz, Joshua; Gray, Joe W; López, Claudia S; Nan, Xiaolin

2017-01-01

Sample preparation is critical to biological electron microscopy (EM), and there have been continuous efforts on optimizing the procedures to best preserve structures of interest in the sample. However, a quantitative characterization of the morphological changes associated with each step in EM sample preparation is currently lacking. Using correlative EM and superresolution microscopy (SRM), we have examined the effects of different drying methods as well as osmium tetroxide (OsO4) post-fixation on cell morphology during scanning electron microscopy (SEM) sample preparation. Here, SRM images of the sample acquired under hydrated conditions were used as a baseline for evaluating morphological changes as the sample went through SEM sample processing. We found that both chemical drying and critical point drying lead to a mild cellular boundary retraction of ~60 nm. Post-fixation by OsO4 causes at least 40 nm additional boundary retraction. We also found that coating coverslips with adhesion molecules such as fibronectin prior to cell plating helps reduce cell distortion from OsO4 post-fixation. These quantitative measurements offer useful information for identifying causes of cell distortions in SEM sample preparation and improving current procedures.

Electron spin relaxation enhancement measurements of interspin distances in human, porcine, and Rhodobacter electron transfer flavoprotein ubiquinone oxidoreductase (ETF QO)

Science.gov (United States)

Fielding, Alistair J.; Usselman, Robert J.; Watmough, Nicholas; Simkovic, Martin; Frerman, Frank E.; Eaton, Gareth R.; Eaton, Sandra S.

2008-02-01

Electron transfer flavoprotein-ubiquinone oxidoreductase (ETF-QO) is a membrane-bound electron transfer protein that links primary flavoprotein dehydrogenases with the main respiratory chain. Human, porcine, and Rhodobacter sphaeroides ETF-QO each contain a single [4Fe-4S] 2+,1+ cluster and one equivalent of FAD, which are diamagnetic in the isolated enzyme and become paramagnetic on reduction with the enzymatic electron donor or with dithionite. The anionic flavin semiquinone can be reduced further to diamagnetic hydroquinone. The redox potentials for the three redox couples are so similar that it is not possible to poise the proteins in a state where both the [4Fe-4S] + cluster and the flavoquinone are fully in the paramagnetic form. Inversion recovery was used to measure the electron spin-lattice relaxation rates for the [4Fe-4S] + between 8 and 18 K and for semiquinone between 25 and 65 K. At higher temperatures the spin-lattice relaxation rates for the [4Fe-4S] + were calculated from the temperature-dependent contributions to the continuous wave linewidths. Although mixtures of the redox states are present, it was possible to analyze the enhancement of the electron spin relaxation of the FAD semiquinone signal due to dipolar interaction with the more rapidly relaxing [4Fe-4S] + and obtain point-dipole interspin distances of 18.6 ± 1 Å for the three proteins. The point-dipole distances are within experimental uncertainty of the value calculated based on the crystal structure of porcine ETF-QO when spin delocalization is taken into account. The results demonstrate that electron spin relaxation enhancement can be used to measure distances in redox poised proteins even when several redox states are present.

Electron spin relaxation enhancement measurements of interspin distances in human, porcine, and Rhodobacter electron transfer flavoprotein-ubiquinone oxidoreductase (ETF-QO).

Science.gov (United States)

Fielding, Alistair J; Usselman, Robert J; Watmough, Nicholas; Simkovic, Martin; Frerman, Frank E; Eaton, Gareth R; Eaton, Sandra S

2008-02-01

Electron transfer flavoprotein-ubiquinone oxidoreductase (ETF-QO) is a membrane-bound electron transfer protein that links primary flavoprotein dehydrogenases with the main respiratory chain. Human, porcine, and Rhodobacter sphaeroides ETF-QO each contain a single [4Fe-4S](2+,1+) cluster and one equivalent of FAD, which are diamagnetic in the isolated enzyme and become paramagnetic on reduction with the enzymatic electron donor or with dithionite. The anionic flavin semiquinone can be reduced further to diamagnetic hydroquinone. The redox potentials for the three redox couples are so similar that it is not possible to poise the proteins in a state where both the [4Fe-4S](+) cluster and the flavoquinone are fully in the paramagnetic form. Inversion recovery was used to measure the electron spin-lattice relaxation rates for the [4Fe-4S](+) between 8 and 18K and for semiquinone between 25 and 65K. At higher temperatures the spin-lattice relaxation rates for the [4Fe-4S](+) were calculated from the temperature-dependent contributions to the continuous wave linewidths. Although mixtures of the redox states are present, it was possible to analyze the enhancement of the electron spin relaxation of the FAD semiquinone signal due to dipolar interaction with the more rapidly relaxing [4Fe-4S](+) and obtain point-dipole interspin distances of 18.6+/-1A for the three proteins. The point-dipole distances are within experimental uncertainty of the value calculated based on the crystal structure of porcine ETF-QO when spin delocalization is taken into account. The results demonstrate that electron spin relaxation enhancement can be used to measure distances in redox poised proteins even when several redox states are present.

A direct electron detector for time-resolved MeV electron microscopy

Energy Technology Data Exchange (ETDEWEB)

Vecchione, T.; Denes, P.; Jobe, R. K.; Johnson, I. J.; Joseph, J. M.; Li, R. K.; Perazzo, A.; Shen, X.; Wang, X. J.; Weathersby, S. P.; Yang, J.; Zhang, D.

2017-03-01

The introduction of direct electron detectors enabled the structural biology revolution of cryogenic electron microscopy. Direct electron detectors are now expected to have a similarly dramatic impact on time-resolved MeV electron microscopy, particularly by enabling both spatial and temporal jitter correction. Here we report on the commissioning of a direct electron detector for time-resolved MeV electron microscopy. The direct electron detector demonstrated MeV single electron sensitivity and is capable of recording megapixel images at 180 Hz. The detector has a 15-bit dynamic range, better than 30-μmμm spatial resolution and less than 20 analogue-to-digital converter count RMS pixel noise. The unique capabilities of the direct electron detector and the data analysis required to take advantage of these capabilities are presented. The technical challenges associated with generating and processing large amounts of data are also discussed.

CMOS biomicrosystems where electronics meets biology

CERN Document Server

2011-01-01

"The book will address the-state-of-the-art in integrated Bio-Microsystems that integrate microelectronics with fluidics, photonics, and mechanics. New exciting opportunities in emerging applications that will take system performance beyond offered by traditional CMOS based circuits are discussed in detail. The book is a must for anyone serious about microelectronics integration possibilities for future technologies. The book is written by top notch international experts in industry and academia. The intended audience is practicing engineers with electronics background that want to learn about integrated microsystems. The book will be also used as a recommended reading and supplementary material in graduate course curriculum"--

Redox-capacitor to connect electrochemistry to redox-biology.

Science.gov (United States)

Kim, Eunkyoung; Leverage, W Taylor; Liu, Yi; White, Ian M; Bentley, William E; Payne, Gregory F

2014-01-07

It is well-established that redox-reactions are integral to biology for energy harvesting (oxidative phosphorylation), immune defense (oxidative burst) and drug metabolism (phase I reactions), yet there is emerging evidence that redox may play broader roles in biology (e.g., redox signaling). A critical challenge is the need for tools that can probe biologically-relevant redox interactions simply, rapidly and without the need for a comprehensive suite of analytical methods. We propose that electrochemistry may provide such a tool. In this tutorial review, we describe recent studies with a redox-capacitor film that can serve as a bio-electrode interface that can accept, store and donate electrons from mediators commonly used in electrochemistry and also in biology. Specifically, we (i) describe the fabrication of this redox-capacitor from catechols and the polysaccharide chitosan, (ii) discuss the mechanistic basis for electron exchange, (iii) illustrate the properties of this redox-capacitor and its capabilities for promoting redox-communication between biology and electrodes, and (iv) suggest the potential for enlisting signal processing strategies to "extract" redox information. We believe these initial studies indicate broad possibilities for enlisting electrochemistry and signal processing to acquire "systems level" redox information from biology.

Biological bases of human musicality.

Science.gov (United States)

Perrone-Capano, Carla; Volpicelli, Floriana; di Porzio, Umberto

2017-04-01

Music is a universal language, present in all human societies. It pervades the lives of most human beings and can recall memories and feelings of the past, can exert positive effects on our mood, can be strongly evocative and ignite intense emotions, and can establish or strengthen social bonds. In this review, we summarize the research and recent progress on the origins and neural substrates of human musicality as well as the changes in brain plasticity elicited by listening or performing music. Indeed, music improves performance in a number of cognitive tasks and may have beneficial effects on diseased brains. The emerging picture begins to unravel how and why particular brain circuits are affected by music. Numerous studies show that music affects emotions and mood, as it is strongly associated with the brain's reward system. We can therefore assume that an in-depth study of the relationship between music and the brain may help to shed light on how the mind works and how the emotions arise and may improve the methods of music-based rehabilitation for people with neurological disorders. However, many facets of the mind-music connection still remain to be explored and enlightened.

Electron microscopy of CO/sub 2/-laser-induced effects in human fibrocartilage

Energy Technology Data Exchange (ETDEWEB)

Whipple, T.L.; Marotta, J.J.; May, T.C.; Caspari, R.B.; Meyers, J.F.

1987-01-01

Previous reports of effects of CO/sub 2/ laser energy on human fibrocartilage suggest thermal injury extends to a depth of approximately 70 microns from the target surface with power settings of 35 W and exposure times of 0.5 seconds. The present study was undertaken to look for more subtle evidence of thermal alteration of human fibrocartilage treated with CO/sub 2/ laser irradiation. Fifteen human menisci were irradiated at power settings of 10, 20, and 30 W with exposure times of 0.1 and 0.5 seconds. The specimens were immediately fixed and sectioned for electron microscopic examination. Loss of a normal cross banding, and marginal clarity of individual collagen fibers were observed in the extracellular matrix and were observed at distances up to 300 microns from the exposed tissue surface. In addition, cellular changes at similar tissue depth consisted of cell membrane invaginations, clumping of nuclear chromatin, breakdown of endoplasmic reticulum architecture, and loss of mitochondria and Golgi complexes from the cytoplasm were observed. This study demonstrates deeper penetration of a radiation that was previously appreciated by light microscopy in irradiated human fibrocartilage, although the implications with respect to contraside viability and healing potential of the tissue in vivo is not known.

Biological effects of particle radiation

International Nuclear Information System (INIS)

Sakamoto, Kiyohiko

1988-01-01

Conventional radiations such as photons, gamma rays or electrons show several physical or biological disadvantages to bring tumors to cure, therefore, more and more attentions is being paid to new modalitie such as fast neutrons, protons, negative pions and heavy ions, which are expected to overcome some of the defects of the conventional radiations. Except for fast neutrons, these particle radiations show excellet physical dose localization in tissue, moreover, in terms of biological effects, they demonstrate several features compared to conventional radiations, namely low oxygen enhancement ratio, high value of relative biological effectiveness, smaller cellular recovery, larger therapeutic gain factor and less cell cycle dependency in radiation sensitivity. In present paper the biological effects of particle radiations are shown comparing to the effects of conventional radiations. (author)

Study of electron densities of normal and neoplastic human breast tissues by Compton scattering using synchrotron radiation

Energy Technology Data Exchange (ETDEWEB)

Antoniassi, M.; Conceicao, A.L.C. [Departamento de Fisica-Faculdade de Filosofia Ciencias e Letras de Ribeirao Preto-Universidade de Sao Paulo, Ribeirao Preto, Sao Paulo (Brazil); Poletti, M.E., E-mail: poletti@ffclrp.usp.br [Departamento de Fisica-Faculdade de Filosofia Ciencias e Letras de Ribeirao Preto-Universidade de Sao Paulo, Ribeirao Preto, Sao Paulo (Brazil)

2012-07-15

Electron densities of 33 samples of normal (adipose and fibroglangular) and neoplastic (benign and malignant) human breast tissues were determined through Compton scattering data using a monochromatic synchrotron radiation source and an energy dispersive detector. The area of Compton peaks was used to determine the electron densities of the samples. Adipose tissue exhibits the lowest values of electron density whereas malignant tissue the highest. The relationship with their histology was discussed. Comparison with previous results showed differences smaller than 4%. - Highlights: Black-Right-Pointing-Pointer Electron density of normal and neoplastic breast tissues was measured using Compton scattering. Black-Right-Pointing-Pointer Monochromatic synchrotron radiation was used to obtain the Compton scattering data. Black-Right-Pointing-Pointer The area of Compton peaks was used to determine the electron densities of samples. Black-Right-Pointing-Pointer Adipose tissue shows the lowest electron density values whereas the malignant tissue the highest. Black-Right-Pointing-Pointer Comparison with previous results showed differences smaller than 4%.

Study of electron densities of normal and neoplastic human breast tissues by Compton scattering using synchrotron radiation

International Nuclear Information System (INIS)

Antoniassi, M.; Conceição, A.L.C.; Poletti, M.E.

2012-01-01

Electron densities of 33 samples of normal (adipose and fibroglangular) and neoplastic (benign and malignant) human breast tissues were determined through Compton scattering data using a monochromatic synchrotron radiation source and an energy dispersive detector. The area of Compton peaks was used to determine the electron densities of the samples. Adipose tissue exhibits the lowest values of electron density whereas malignant tissue the highest. The relationship with their histology was discussed. Comparison with previous results showed differences smaller than 4%. - Highlights: ► Electron density of normal and neoplastic breast tissues was measured using Compton scattering. ► Monochromatic synchrotron radiation was used to obtain the Compton scattering data. ► The area of Compton peaks was used to determine the electron densities of samples. ► Adipose tissue shows the lowest electron density values whereas the malignant tissue the highest. ► Comparison with previous results showed differences smaller than 4%.

Branching processes in biology

CERN Document Server

Kimmel, Marek

2015-01-01

This book provides a theoretical background of branching processes and discusses their biological applications. Branching processes are a well-developed and powerful set of tools in the field of applied probability. The range of applications considered includes molecular biology, cellular biology, human evolution and medicine. The branching processes discussed include Galton-Watson, Markov, Bellman-Harris, Multitype, and General Processes. As an aid to understanding specific examples, two introductory chapters, and two glossaries are included that provide background material in mathematics and in biology. The book will be of interest to scientists who work in quantitative modeling of biological systems, particularly probabilists, mathematical biologists, biostatisticians, cell biologists, molecular biologists, and bioinformaticians. The authors are a mathematician and cell biologist who have collaborated for more than a decade in the field of branching processes in biology for this new edition. This second ex...

Molecular biology of the cell

CERN Document Server

Alberts, Bruce; Lewis, Julian

2000-01-01

Molecular Biology of the Cell is the classic in-dept text reference in cell biology. By extracting the fundamental concepts from this enormous and ever-growing field, the authors tell the story of cell biology, and create a coherent framework through which non-expert readers may approach the subject. Written in clear and concise language, and beautifully illustrated, the book is enjoyable to read, and it provides a clear sense of the excitement of modern biology. Molecular Biology of the Cell sets forth the current understanding of cell biology (completely updated as of Autumn 2001), and it explores the intriguing implications and possibilities of the great deal that remains unknown. The hallmark features of previous editions continue in the Fourth Edition. The book is designed with a clean and open, single-column layout. The art program maintains a completely consistent format and style, and includes over 1,600 photographs, electron micrographs, and original drawings by the authors. Clear and concise concept...

Integrating biological redesign: where synthetic biology came from and where it needs to go.

Science.gov (United States)

Way, Jeffrey C; Collins, James J; Keasling, Jay D; Silver, Pamela A

2014-03-27

Synthetic biology seeks to extend approaches from engineering and computation to redesign of biology, with goals such as generating new chemicals, improving human health, and addressing environmental issues. Early on, several guiding principles of synthetic biology were articulated, including design according to specification, separation of design from fabrication, use of standardized biological parts and organisms, and abstraction. We review the utility of these principles over the past decade in light of the field's accomplishments in building complex systems based on microbial transcription and metabolism and describe the progress in mammalian cell engineering. Copyright © 2014 Elsevier Inc. All rights reserved.

Monte Carlo electron-trajectory simulations in bright-field and dark-field STEM: Implications for tomography of thick biological sections

Energy Technology Data Exchange (ETDEWEB)

Sousa, A.A.; Hohmann-Marriott, M.F.; Zhang, G. [Laboratory of Bioengineering and Physical Science, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bldg. 13, Rm. 3N17, 13 South Drive, Bethesda, MD 20892-5766 (United States); Leapman, R.D. [Laboratory of Bioengineering and Physical Science, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bldg. 13, Rm. 3N17, 13 South Drive, Bethesda, MD 20892-5766 (United States)], E-mail: leapmanr@mail.nih.gov

2009-02-15

A Monte Carlo electron-trajectory calculation has been implemented to assess the optimal detector configuration for scanning transmission electron microscopy (STEM) tomography of thick biological sections. By modeling specimens containing 2 and 3 at% osmium in a carbon matrix, it was found that for 1-{mu}m-thick samples the bright-field (BF) and annular dark-field (ADF) signals give similar contrast and signal-to-noise ratio provided the ADF inner angle and BF outer angle are chosen optimally. Spatial resolution in STEM imaging of thick sections is compromised by multiple elastic scattering which results in a spread of scattering angles and thus a spread in lateral distances of the electrons leaving the bottom surface. However, the simulations reveal that a large fraction of these multiply scattered electrons are excluded from the BF detector, which results in higher spatial resolution in BF than in high-angle ADF images for objects situated towards the bottom of the sample. The calculations imply that STEM electron tomography of thick sections should be performed using a BF rather than an ADF detector. This advantage was verified by recording simultaneous BF and high-angle ADF STEM tomographic tilt series from a stained 600-nm-thick section of C. elegans. It was found that loss of spatial resolution occurred markedly at the bottom surface of the specimen in the ADF STEM but significantly less in the BF STEM tomographic reconstruction. Our results indicate that it might be feasible to use BF STEM tomography to determine the 3D structure of whole eukaryotic microorganisms prepared by freeze-substitution, embedding, and sectioning.

Dose rate effect models for biological reaction to ionizing radiation in human cell lines

International Nuclear Information System (INIS)

Magae, Junji; Ogata, Hiromitsu

2008-01-01

Full text: Because of biological responses to ionizing radiation are dependent on irradiation time or dose rate as well as dose, simultaneous inclusion of dose and dose rate is required to evaluate the risk of long term irradiation at low dose rates. We previously published a novel statistical model for dose rate effect, modified exponential (MOE) model, which predicts irradiation time-dependent biological response to low dose rate ionizing radiation, by analyzing micronucleus formation and growth inhibition in a human osteosarcoma cell line, exposed to wide range of doses and dose rates of gamma-rays. MOE model demonstrates that logarithm of median effective dose exponentially increases in low dose rates, and thus suggests that the risk approaches to zero at infinitely low dose rate. In this paper, we extend the analysis in various kinds of human cell lines exposed to ionizing radiation for more than a year. We measured micronucleus formation and [ 3 H]thymidine uptake in human cell lines including an osteosarcoma, a DNA-dependent protein kinase-deficient glioma, a SV40-transformed fibroblast derived from an ataxia telangiectasia patient, a normal fibroblast, and leukemia cell lines. Cells were exposed to gamma-rays in irradiation room bearing 50,000 Ci of cobalt-60. After the irradiation, they were cultured for 24 h in the presence of cytochalasin B to block cytokinesis, and cytoplasm and nucleus were stained with DAPI and prospidium iodide. The number of binuclear cells bearing a micronucleus was counted under a fluorescence microscope. For proliferation inhibition, cells were cultured for 48 h after the irradiation and [ 3 H] thymidine was pulsed for 4 h before harvesting. We statistically analyzed the data for quantitative evaluation of radiation risk. While dose and dose rate relationship cultured within one month followed MOE model in cell lines holding wild-type DNA repair system, dose rate effect was greatly impaired in DNA repair-deficient cell lines

Radiation physics, biophysics, and radiation biology

International Nuclear Information System (INIS)

Hall, E.J.; Zaider, M.

1993-05-01

Research at the Center for Radiological Research is a multidisciplenary blend of physics, chemistry and biology aimed at understanding the mechanisms involved in the health problems resulting from human exposure to ionizing radiations. The focus is increased on biochemistry and the application of the techniques of molecular biology to the problems of radiation biology. Research highlights of the program from the past year are described. A mathematical model describing the production of single-strand and double-strand breaks in DNA as a function radiation quality has been completed. For the first time Monte Carlo techniques have been used to obtain directly the spatial distribution of DNA moieties altered by radiation. This information was obtained by including the transport codes a realistic description of the electronic structure of DNA. We have investigated structure activity relationships for the potential oncogenicity of a new generation of bioreductive drugs that function as hypoxic cytotoxins. Experimental and theoretical investigation of the inverse dose rate effect, whereby medium LET radiations actually produce an c effect when the dose is protracted, is now at a point where the basic mechanisms are reasonably understood and the complex interplay between dose, dose rate and radiation quality which is necessary for the effect to be present can now be predicted at least in vitro. In terms of early radiobiological damage, a quantitative link has been established between basic energy deposition and locally multiply damaged sites, the radiochemical precursor of DNA double strand breaks; specifically, the spatial and energy deposition requirements necessary to form LMDs have been evaluated. For the first time, a mechanically understood ''biological fingerprint'' of high-LET radiation has been established. Specifically measurement of the ratio of inter-to intra-chromosomal aberrations produces a unique signature from alpha-particles or neutrons

Radiation physics, biophysics, and radiation biology

Energy Technology Data Exchange (ETDEWEB)

Hall, E.J.; Zaider, M.

1993-05-01

Research at the Center for Radiological Research is a multidisciplenary blend of physics, chemistry and biology aimed at understanding the mechanisms involved in the health problems resulting from human exposure to ionizing radiations. The focus is increased on biochemistry and the application of the techniques of molecular biology to the problems of radiation biology. Research highlights of the program from the past year are described. A mathematical model describing the production of single-strand and double-strand breaks in DNA as a function radiation quality has been completed. For the first time Monte Carlo techniques have been used to obtain directly the spatial distribution of DNA moieties altered by radiation. This information was obtained by including the transport codes a realistic description of the electronic structure of DNA. We have investigated structure activity relationships for the potential oncogenicity of a new generation of bioreductive drugs that function as hypoxic cytotoxins. Experimental and theoretical investigation of the inverse dose rate effect, whereby medium LET radiations actually produce an c effect when the dose is protracted, is now at a point where the basic mechanisms are reasonably understood and the complex interplay between dose, dose rate and radiation quality which is necessary for the effect to be present can now be predicted at least in vitro. In terms of early radiobiological damage, a quantitative link has been established between basic energy deposition and locally multiply damaged sites, the radiochemical precursor of DNA double strand breaks; specifically, the spatial and energy deposition requirements necessary to form LMDs have been evaluated. For the first time, a mechanically understood biological fingerprint'' of high-LET radiation has been established. Specifically measurement of the ratio of inter-to intra-chromosomal aberrations produces a unique signature from alpha-particles or neutrons.

Mega-electron-volt ultrafast electron diffraction at SLAC National Accelerator Laboratory

Energy Technology Data Exchange (ETDEWEB)

Weathersby, S. P.; Brown, G.; Chase, T. F.; Coffee, R.; Corbett, J.; Eichner, J. P.; Frisch, J. C.; Fry, A. R.; Gühr, M.; Hartmann, N.; Hast, C.; Hettel, R.; Jobe, R. K.; Jongewaard, E. N.; Lewandowski, J. R.; Li, R. K., E-mail: lrk@slac.stanford.edu; Lindenberg, A. M.; Makasyuk, I.; May, J. E.; McCormick, D. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025 (United States); and others

2015-07-15

Ultrafast electron probes are powerful tools, complementary to x-ray free-electron lasers, used to study structural dynamics in material, chemical, and biological sciences. High brightness, relativistic electron beams with femtosecond pulse duration can resolve details of the dynamic processes on atomic time and length scales. SLAC National Accelerator Laboratory recently launched the Ultrafast Electron Diffraction (UED) and microscopy Initiative aiming at developing the next generation ultrafast electron scattering instruments. As the first stage of the Initiative, a mega-electron-volt (MeV) UED system has been constructed and commissioned to serve ultrafast science experiments and instrumentation development. The system operates at 120-Hz repetition rate with outstanding performance. In this paper, we report on the SLAC MeV UED system and its performance, including the reciprocal space resolution, temporal resolution, and machine stability.

Flexible and wearable electronic silk fabrics for human physiological monitoring

Science.gov (United States)

Mao, Cuiping; Zhang, Huihui; Lu, Zhisong

2017-09-01

The development of textile-based devices for human physiological monitoring has attracted tremendous interest in recent years. However, flexible physiological sensing elements based on silk fabrics have not been realized. In this paper, ZnO nanorod arrays are grown in situ on reduced graphene oxide-coated silk fabrics via a facile electro-deposition method for the fabrication of silk-fabric-based mechanical sensing devices. The data show that well-aligned ZnO nanorods with hexagonal wurtzite crystalline structures are synthesized on the conductive silk fabric surface. After magnetron sputtering of gold electrodes, silk-fabric-based devices are produced and applied to detect periodic bending and twisting. Based on the electric signals, the deformation and release processes can be easily differentiated. Human arterial pulse and respiration can also be real-time monitored to calculate the pulse rate and respiration frequency, respectively. Throat vibrations during coughing and singing are detected to demonstrate the voice recognition capability. This work may not only help develop silk-fabric-based mechanical sensing elements for potential applications in clinical diagnosis, daily healthcare monitoring and voice recognition, but also provide a versatile method for fabricating textile-based flexible electronic devices.

The Use of Liquid Isopropyl Alcohol and Hydrogen Peroxide Gas Plasma to Biologically Decontaminate Spacecraft Electronics

Science.gov (United States)

Bonner, J. K.; Tudryn, Carissa D.; Choi, Sun J.; Eulogio, Sebastian E.; Roberts, Timothy J.; Tudryn, Carissa D.

2006-01-01

Legitimate concern exists regarding sending spacecraft and their associated hardware to solar system bodies where they could possibly contaminate the body's surface with terrestrial microorganisms. The NASA approved guidelines for sterilization as set forth in NPG 8020.12C, which is consistent with the biological contamination control objectives of the Committee on Space Research (COSPAR), recommends subjecting the spacecraft and its associated hardware to dry heat-a dry heat regimen that could potentially employ a temperature of 110(deg)C for up to 200 hours. Such a temperature exposure could prove detrimental to the spacecraft electronics. The stimulated growth of intermetallic compounds (IMCs) in metallic interconnects and/or thermal degradation of organic materials composing much of the hardware could take place over a prolonged temperature regimen. Such detrimental phenomena would almost certainly compromise the integrity and reliability of the electronics. Investigation of sterilization procedures in the medical field suggests that hydrogen peroxide (H202) gas plasma (HPGP) technology can effectively function as an alternative to heat sterilization, especially for heat-sensitive items. Treatment with isopropyl alcohol (IPA) in liquid form prior to exposure of the hardware to HPGP should also prove beneficial. Although IPA is not a sterilant, it is frequently used as a disinfectant because of its bactericidal properties. The use of IPA in electronics cleaning is widely recognized and has been utilized for many years with no adverse affects reported. In addition, IPA is the principal ingredient of the test fluid used in ionic contamination testers to assess the amount of ionic contamination found on the surfaces of printed wiring assemblies. This paper will set forth experimental data confirming the feasibility of the IPA/H202 approach to reach acceptable microbial reduction (MR) levels of spacecraft electronic hardware. In addition, a proposed process flow in

Electron density values of various human tissues: in vitro Compton scatter measurements and calculated ranges

International Nuclear Information System (INIS)

Shrimpton, P.C.

1981-01-01

Accurate direct measurements of electron density have been performed on specimens from 10 different tissue types of the human body, representing the major organs, using a Compton scatter technique. As a supplement to these experimental values, calculations have been carried out to determine the electron densities expected for these tissue types. The densities observed are in good agreement with the broad ranges deduced from the basic data previously published. The results of both the in vitro sample measurements and the approximate calculations indicate that the electron density of most normal healthy soft tissue can be expected to fall within the fairly restricted range of +- 5% around 3.4 X 10 23 electrons per cm 3 . The obvious exception to this generalisation is the result for lung tissue, which falls considerably below this range owing to the high air content inherent in its construction. In view of such an overall limited variation with little difference between tissues, it would appear that electron density alone is likely to be a rather poor clinical parameter for tissue analysis, with high accuracy and precision being essential in any in vivo Compton measurements for imaging or diagnosis on specific organs. (author)

The use of human hair as biodosimeter

International Nuclear Information System (INIS)

Tepe Çam, S.; Polat, M.; Seyhan, N.

2014-01-01

The potential use of human hair samples as biologic dosimeter was investigated by electron spin resonance (ESR) spectroscopy. The hair samples were obtained from female volunteers and classified according to the color, age and whether they are natural or dyed. Natural black, brown, red, blonde and dyed black hair samples were irradiated at low doses (5–50 Gy) and high doses (75–750 Gy) by gamma source giving the dose rate of 0.25 Gy/s in The Sarayköy Establishment of Turkish Atomic Energy Authority. While the peak heights and g-values (2.0021–2.0023) determined from recorded spectra of hair were color dependent, the peak-to-peak line widths were varied according to natural or dyed hair (ΔH pp : 0.522–0.744 mT). In all samples, the linear dose–response curves at low doses saturated after ∼300 Gy. In black hair samples taken from different individuals, differences in the structure of the spectrum and signal intensities were not observed. The EPR signal intensities of samples stored at room temperature for 22 days fell to their half-values in 44 h in black hair, 41 h in blonde and brown hairs, 35 h in dyed black hair and in 17 h in red hair. The activation energies of samples annealed at high temperatures for different periods of time were correlated well with those obtained in the literature. In conclusion, hair samples can be used as a biological dosimeter considering the limitations showed in this study. - Highlights: • Applied electron spin resonance spectroscopy to human hair used in biodosimetry. • Showed the limitations of hair samples using as a biological dosimeter. • Provided more systematic information on radiation-induced radicals in hair. • Found at least 3 different contributions in the RIS. That is the major finding of this work

[Is there a "biology of violence"?].

Science.gov (United States)

Karli, Pierre

2004-01-01

Human violence does not stem from any specific biological substrate. As affective processes play a pre-eminent role in the elaboration and evolution of social interactions, a "biology of violence" draws essentially upon the concepts, methods and techniques of "affective neuroscience".

Electron transfer in proteins

DEFF Research Database (Denmark)

Farver, O; Pecht, I

1991-01-01

Electron migration between and within proteins is one of the most prevalent forms of biological energy conversion processes. Electron transfer reactions take place between active centers such as transition metal ions or organic cofactors over considerable distances at fast rates and with remarkable...... specificity. The electron transfer is attained through weak electronic interaction between the active sites, so that considerable research efforts are centered on resolving the factors that control the rates of long-distance electron transfer reactions in proteins. These factors include (in addition......-containing proteins. These proteins serve almost exclusively in electron transfer reactions, and as it turns out, their metal coordination sites are endowed with properties uniquely optimized for their function....

Autopsy tissues as biological monitors of human exposure to environmental pollutants. A case study: Concentrations of metals and PCDD/Fs in subjects living near a hazardous waste incinerator.

Science.gov (United States)

Domingo, José L; García, Francisco; Nadal, Martí; Schuhmacher, Marta

2017-04-01

Human biomonitoring is of tremendous importance to prevent potential adverse effects derived from human exposure to chemicals. Blood and urine are among the biological monitors more frequently used. However, biological matrices such as breast milk, hair, nails, saliva, feces, teeth, and expired air are also often used. In addition, and focused mainly on long-term exposure, adipose tissue and other human tissues like bone, liver, brain or kidney, are also used as biological monitors of certain substances, especially for long-term biomonitoring. However, for this kind of tissues sampling is always a limiting factor. In this paper, we have examined the role of autopsy tissues as biological monitors of human exposure to environmental pollutants. For it, we have used a case study conducted near a hazardous waste incinerator (HWI) in Catalonia (Spain), in which the concentrations of metals and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), have been periodically determined in autopsy tissues of subjects living in the area under potential influence of the facility. This case study does not show advantages -in comparison to other appropriate biomonitors such as blood- in using autopsy tissues in the monitoring of long-term exposure to metals and PCDD/Fs. Copyright © 2017 Elsevier Inc. All rights reserved.

Electron beam agrobionanotechnologies for agriculture and food industry enabled by electron accelerators

Science.gov (United States)

Pavlov, Y. S.; Revina, A. A.; Souvorova, O. V.; Voropaeva, N. L.; Chekmar, D. V.; Abkhalimov, E. V.; Zavyalov, M. A.; Filippovich, V. P.

2017-12-01

Electron beam (EB) radiation technologies have been employed to increase efficiency of biologically active nanochips developed for agricultural plants seed pre-treatment with purpose of enhancing crop yield and productivity. Iron-containing nanoparticles (NPs), synthesized in reverse micelles following known radiation-chemical technique, have served as a multifunctional biologically active and phytosanitary substance of the chips. Porous chip carriers activation has been performed by EB ionization (doze 20kGy) of the active carbons (AC) prepared from agricultural waste and by-products: Jerusalem artichoke (Helianthus tuberosus) straw, rape (Brassica napus L. ssp. oleifera Metzg) straw, camelina (Camelina sativa (L.) Crantz) straw, wheat (Triticum aestivum) straw. Three methods, UV-VIS spectrophotometry, Electron Paramagnetic Resonance (EPR) spectroscopy, cyclic voltammetry (CV) have been used for process control and characterization of radiation-activated and NPs-modified ACs. The results show a notable effect of ACs activation by electron beam radiation, evidenced by FeNPs-adsorption capacity increase. Studies of the impact of Fe NPs-containing nanochip technology on enhancement of seeds germination rate and seedlings vigour suggest that reported electron beam radiation treatment techniques of the ACs from selected agricultural residues may be advantageous for industrial application.

Electric and magnetic fields in medicine and biology

International Nuclear Information System (INIS)

Anon.

1985-01-01

Papers Include: The effects of low frequency (50 Hz) magnetic fields on neuro-chemical transmission in vitro; Morphological changes in E Coli subjected to DC electrical fields; An investigation of some claimed biological effects of electromagnetic fields; Electrical phenomena and bone healing - a comparison of contemporary techniques; Clinical evaluations of a portable module emitting pulsed RF energy; The design, construction and performance of a magnetic nerve stimulator; The principle of electric field tomography and its application to selective read-out of information from peripheral nerves; Applied potential tomography - clinical applications; Impendance imaging using a linear electrode array; Mathematics as an aid to experiment: human body currents induced by power frequency electric fields; Effects of electric field near 750KV transmission line and protection against their harmful consequences; Leukemia and electromagnetic fields: a case-control study; Overhead power lines and childhood cancer; Magnetic measurement of nerve action currents - a new intraoperative recording technique; The potential use of electron spin resonance or impedance measurement to image neuronal electrical activity in the human brain

Tracking Human Immunodeficiency Virus-1 Infection in the Humanized DRAG Mouse Model

OpenAIRE

Jiae Kim; Jiae Kim; Kristina K. Peachman; Kristina K. Peachman; Ousman Jobe; Ousman Jobe; Elaine B. Morrison; Atef Allam; Atef Allam; Linda Jagodzinski; Sofia A. Casares; Mangala Rao

2017-01-01

Humanized mice are emerging as an alternative model system to well-established non-human primate (NHP) models for studying human immunodeficiency virus (HIV)-1 biology and pathogenesis. Although both NHP and humanized mice have their own strengths and could never truly reflect the complex human immune system and biology, there are several advantages of using the humanized mice in terms of using primary HIV-1 for infection instead of simian immunodeficiency virus or chimera simian/HIV. Several...

Biologically active substances of edible insects and their use in agriculture, veterinary and human medicine a review

Directory of Open Access Journals (Sweden)

Jiri Mlcek

2014-12-01

Full Text Available Possibilities of edible insect use in Western countries is now increasingly debated issue. Insects in Asian, African, American and South Central American cultures are mainly nutritional components. In Europe and other developed countries, however, insect is used in different ways, and this issue is viewed from a different angle. Insects are mainly used as feed for animals, in the organic waste recycling systems, in human and veterinary medicine, material production (such as silk etc. This review summarizes up-to-date knowledge about using edible insects in human, veterinary medicine and agriculture, especially from the viewpoint of the biological and chemical content of active substances and the possibilities of further use in these areas.

Biological effects of tritiated water in low concentration of human lymphocyte chromosome

International Nuclear Information System (INIS)

Tanaka, K.; Kamada, N.; Sawaeda, S.

1992-01-01

This study was undertaken to investigate the dose-response relationship of tritiated water (HTO) for chromosome aberration in the human lymphocytes, at low dose in vitro exposure ranging from 0.1-1 Gy. The Relative Biological Effectiveness values of HTO with respect to 60 Co gamma ray at a dose rate of 2 cGy/min(15 mCi/ml), at low dose range for the induction of dicentric and centric ring chromosomes were 2.7 in lymphocytes. Also lymphocytes were chronically exposed to HTO for 67 to 80 hrs at different lower dose rates (0.5 and 0.02 cGy/min). There was a 77% decrease in the yields of dicentrics and centric rings, at the dose rate of 0.02cGy/min of HTO, presenting a clear dose rate effect of HTO. The RBE value of HTO relative to 137 Cs gamma ray was 2.0 at the dose rate of 0.02cGy/min(0.15mCi/ml). This suggests that a higher dose rate of HTO exposure has a higher risk and a decrease of RBE value at low dose rate. These results provide useful information for the assessment of health risks in humans specially exposed to low concentration of HTO. (author). 6 refs., 2 figs

Relative biological effectiveness of high energy protons for a human melanoma

International Nuclear Information System (INIS)

Petrovic, I.; Ristic-Fira, A.; Todorovic, D.; Valastro, I.; Cirrone, P.; Cuttone, G.

2005-01-01

Relative biological effectiveness (RBE) for the survival of human melanoma cells induced by high linear energy transfer (LET) protons was investigated. Exponentially growing HTB140 cells were irradiated close to the Bragg peak maximum of the 62 MeV protons, as well as with 60 Co γ-rays, over single doses, ranging from 8-24 Gy. Clonogenic survival and cell viability were assessed up to 48 h post-irradiation, therefore considered as early inactivation effects. Dose dependent cell inactivation induced by high LET protons was observed. Surviving fractions have shown great overlapping with estimated cell viability, both with the increase of dose and with prolonged cell incubation. Evaluated RBEs were higher with the rise of dose, being in the range from 2 to 3. All analyzes performed have demonstrated a very radio-resistant nature of HTB140 melanoma cells. However, high LET protons are able to inactivate these cells in a larger extent compared to the effects of γ-rays. (author)

Biological dosimetry: the potential use of radiation-induced apoptosis in human T-lymphocytes

International Nuclear Information System (INIS)

Menz, R.; Andres, R.; Larsson, B.; Ozsahin, M.; Crompton, N.E.A.; Trott, K.

1997-01-01

An assay for biological dosimetry based on the induction of apoptosis in human T-lymphocytes is described. Radiation-induced apoptosis was assessed by flow cytometric identification of cells displaying apoptosis-associated DNA condensation. CD4 and CD8 T-lymphocytes were analysed. They were recognized on the basis of their cell-surface antigens. Four parameters were measured for both cell types: cell size, granularity, antigen immunofluorescence and DNA content. Apoptosis was quantified as the fraction of CD4-, or CD8-positive cells with a characteristic reduction of cell size and DNA content. At doses below 1 Gy, levels of radiation-induced apoptosis increased for up to 5 days after irradiation. Optimal dose discrimination was observed 4 days after irradiation, at which time the dose-response curves were linear, with a slope of 8% ± 0.5% per 0.1 Gy. In controlled, dose-response experiments the lowest dose level at which the radiation-induced apoptosis frequency was still significantly above control was 0.05 Gy. After 5 days post-irradiation incubation, intra- and interdonor variations were measured and found to be similar; thus, apoptotic levels depend more on the dose than on the donor. The results demonstrate the potential of this assay as a biological dosimeter. (orig.)

XXIII International Conference on Nonlinear Dynamics of Electronic Systems

CERN Document Server

Stoop, Ruedi; Stramaglia, Sebastiano

2017-01-01

This book collects contributions to the XXIII international conference “Nonlinear dynamics of electronic systems”. Topics range from non-linearity in electronic circuits to synchronisation effects in complex networks to biological systems, neural dynamics and the complex organisation of the brain. Resting on a solid mathematical basis, these investigations address highly interdisciplinary problems in physics, engineering, biology and biochemistry.