Science.gov

Sample records for biological samples ii

  1. Spectrophotometric determination of copper(II) in pharmaceutical, biological and water samples by 4-(2'-benzothiazolylazo)-salicylic acid

    NASA Astrophysics Data System (ADS)

    Hashem, E. Y.; Seleim, M. M.; El-Zohry, A. M.

    2011-09-01

    A highly sensitive method is proposed to determine copper(II) ions by forming a stable complex through their interaction with 4-(2'-benzothiazolylazo)-salicylic acid (BTAS) at room temperature and pH of about 5.0. The complex gave a maximum absorption at λ = 485 nm with a molar absorptivity coefficient of 2.35·104 l/(mol·cm). The linear range for the copper determination is 0.63-5.04 mg/l. The method can be applied to determine copper ions in different biological specimens like some drugs and water samples.

  2. Biological sample collector

    DOEpatents

    Murphy, Gloria A.

    2010-09-07

    A biological sample collector is adapted to a collect several biological samples in a plurality of filter wells. A biological sample collector may comprise a manifold plate for mounting a filter plate thereon, the filter plate having a plurality of filter wells therein; a hollow slider for engaging and positioning a tube that slides therethrough; and a slide case within which the hollow slider travels to allow the tube to be aligned with a selected filter well of the plurality of filter wells, wherein when the tube is aligned with the selected filter well, the tube is pushed through the hollow slider and into the selected filter well to sealingly engage the selected filter well and to allow the tube to deposit a biological sample onto a filter in the bottom of the selected filter well. The biological sample collector may be portable.

  3. Preservation of Liquid Biological Samples

    NASA Technical Reports Server (NTRS)

    Putcha, Lakshmi (Inventor); Nimmagudda, Ramalingeshwara (Inventor)

    2004-01-01

    The present invention related to the preservation of a liquid biological sample. The biological sample is exposed to a preservative containing at least about 0.15 g of sodium benzoate and at least about 0.025 g of citric acid per 100 ml of sample. The biological sample may be collected in a vessel or an absorbent mass. The biological sample may also be exposed to a substrate and/or a vehicle.

  4. Preservation of Liquid Biological Samples

    NASA Technical Reports Server (NTRS)

    Putcha, Lakshmi (Inventor); Nimmagudda, Ramalingeshwara R. (Inventor)

    2000-01-01

    The present invention provides a method of preserving a liquid biological sample, comprising the step of: contacting said liquid biological sample with a preservative comprising, sodium benzoate in an amount of at least about 0.15% of the sample (weight/volume) and citric acid in an amount of at least about 0.025% of the sample (weight/volume).

  5. Estimated neutron-activation data for TFTR. Part II. Biological dose rate from sample-materials activation

    SciTech Connect

    Ku, L.; Kolibal, J.G.

    1982-06-01

    The neutron induced material activation dose rate data are summarized for the TFTR operation. This report marks the completion of the second phase of the systematic study of the activation problem on the TFTR. The estimations of the neutron induced activation dose rates were made for spherical and slab objects, based on a point kernel method, for a wide range of materials. The dose rates as a function of cooling time for standard samples are presented for a number of typical neutron spectrum expected during TFTR DD and DT operations. The factors which account for the variations of the pulsing history, the characteristic size of the object and the distance of observation relative to the standard samples are also presented.

  6. Biology II Curriculum Guide. Bulletin 1820.

    ERIC Educational Resources Information Center

    Louisiana State Dept. of Education, Baton Rouge. Div. of Academic Programs.

    In 1986, the Louisiana State Board of Elementary and Secondary Education requested that an advanced course in Biology II be developed. The resulting curriculum guide contains grade appropriate goals, skills, and competencies; suggested activities; suggested materials of instruction; and minimum time allotments for instruction. Biology II is a…

  7. Sample Exchange Evaluation (SEE) Report - Phase II

    SciTech Connect

    Winters, W.I.

    1994-09-28

    This report describes the results from Phase II of the Sample Exchange Evaluation (SEE) Program, a joint effort to compare analytical laboratory performance on samples from the Hanford Site`s high-level waste tanks. In Phase II, the program has been expanded to include inorganic constituents in addition to radionuclides. Results from Phase II that exceeded 20% relative percent difference criteria are identified.

  8. Modular microfluidic system for biological sample preparation

    DOEpatents

    Rose, Klint A.; Mariella, Jr., Raymond P.; Bailey, Christopher G.; Ness, Kevin Dean

    2015-09-29

    A reconfigurable modular microfluidic system for preparation of a biological sample including a series of reconfigurable modules for automated sample preparation adapted to selectively include a) a microfluidic acoustic focusing filter module, b) a dielectrophoresis bacteria filter module, c) a dielectrophoresis virus filter module, d) an isotachophoresis nucleic acid filter module, e) a lyses module, and f) an isotachophoresis-based nucleic acid filter.

  9. Spectroscopic diagnostics for bacteria in biologic sample

    DOEpatents

    El-Sayed, Mostafa A.; El-Sayed, Ivan H.

    2002-01-01

    A method to analyze and diagnose specific bacteria in a biologic sample using spectroscopy is disclosed. The method includes obtaining the spectra of a biologic sample of a non-infected patient for use as a reference, subtracting the reference from the spectra of an infected sample, and comparing the fingerprint regions of the resulting differential spectrum with reference spectra of bacteria in saline. Using this diagnostic technique, specific bacteria can be identified sooner and without culturing, bacteria-specific antibiotics can be prescribed sooner, resulting in decreased likelihood of antibiotic resistance and an overall reduction of medical costs.

  10. Trace Element Analysis of Biological Samples.

    ERIC Educational Resources Information Center

    Veillon, Claude

    1986-01-01

    Reviews background of atomic absorption spectrometry techniques. Discusses problems encountered and precautions to be taken in determining trace elements in the parts-per-billion concentration range and below. Concentrates on determining chromium in biological samples by graphite furnace atomic absorption. Considers other elements, matrices, and…

  11. Biological Sterilization of Returned Mars Samples

    NASA Technical Reports Server (NTRS)

    Allen, C. C.; Albert, F. G.; Combie, J.; Bodnar, R. J.; Hamilton, V. E.; Jolliff, B. L.; Kuebler, K.; Wang, A.; Lindstrom, D. J.; Morris, P. A.

    1999-01-01

    Martian rock and soil, collected by robotic spacecraft, will be returned to terrestrial laboratories early in the next century. Current plans call for the samples to be immediately placed into biological containment and tested for signs of present or past life and biological hazards. It is recommended that "Controlled distribution of unsterilized materials from Mars should occur only if rigorous analyses determine that the materials do not constitute a biological hazard. If any portion of the sample is removed from containment prior to completion of these analyses it should first be sterilized." While sterilization of Mars samples may not be required, an acceptable method must be available before the samples are returned to Earth. The sterilization method should be capable of destroying a wide range of organisms with minimal effects on the geologic samples. A variety of biological sterilization techniques and materials are currently in use, including dry heat, high pressure steam, gases, plasmas and ionizing radiation. Gamma radiation is routinely used to inactivate viruses and destroy bacteria in medical research. Many commercial sterilizers use Co-60 , which emits gamma photons of 1.17 and 1.33 MeV. Absorbed doses of approximately 1 Mrad (10(exp 8) ergs/g) destroy most bacteria. This study investigates the effects of lethal doses of Co-60 gamma radiation on materials similar to those anticipated to be returned from Mars. The goals are to determine the gamma dose required to kill microorganisms in rock and soil samples and to determine the effects of gamma sterilization on the samples' isotopic, chemical and physical properties. Additional information is contained in the original extended abstract.

  12. Microfluidic Tools for Biological Sample Preparation

    SciTech Connect

    Visuri, S R; Ness, K; Dzenitis, J; Benett, B; Bettencourt, K; Hamilton, J; Fisher, K; Krulevitch, P

    2002-04-10

    Researchers at Lawrence Livermore National Laboratory are developing means to collect and identify fluid-based biological pathogens in the forms of proteins, viruses, and bacteria. To support detection instruments, we are developing a flexible fluidic sample preparation unit. The overall goal of this Microfluidic Module is to input a fluid sample, containing background particulates and potentially target compounds, and deliver a processed sample for detection. We are developing techniques for sample purification, mixing, and filtration that would be useful to many applications including immunologic and nucleic acid assays. Sample preparation functions are accomplished with acoustic radiation pressure, dielectrophoresis, and solid phase extraction. We are integrating these technologies into packaged systems with pumps and valves to control fluid flow and investigating small-scale detection methods.

  13. [The ethical implications of conserving biological samples].

    PubMed

    Tazzite, A; Roky, R; Avard, D

    2009-09-01

    The conservation and use of biological samples become more and more frequent all around the world. Biobanks of human body substances (blood, urine, DNA, tissues, cells, etc.), and personal data associated with them are created. They have a double character as they are collections of both human biological samples and personal data. In some cases, the gametes, reproductive tissues, embryos, foetal tissue after abortion or even specimens of dead donors are collected and conserved. Although biobanks raise hopes in both the development of new therapies, new drugs and their integration into clinical medicine, they also point to concerns related to ethical questions such as: the principles of information, the consent of the persons concerned, the confidentiality about the personal data, and in some cases discrimination and stigmatisation. Other ethical aspects could raise gradually as research advance. Research being carried out on human sample requires informed free consent from the person who should be able to consent. The donor must be sufficiently informed about the process of research, the purpose, benefits and the risks involved in participating in this research. In the case of persons unable to give consent such minors or persons with mental disabilities, special measures are undertaken. Once the consent was given, the right of withdrawal has been consistently supported by the various declarations and regulations, but some oppose this right for a number of reasons particularly in the case of research on the samples without risk of physical exposure. In this case the notion of human body integrity is different than in research involving therapeutic or clinical intervention. In the case of withdrawal of consent, the samples should be destroyed, but the anonymous results arising from them and their analysis are not affected. What is the case for future uses? Should the researcher obtain again the consent from the donor for a secondary use of the samples? This is a

  14. Atomic force microscopy of biological samples

    SciTech Connect

    Doktycz, Mitchel John

    2010-01-01

    The ability to evaluate structural-functional relationships in real time has allowed scanning probe microscopy (SPM) to assume a prominent role in post genomic biological research. In this mini-review, we highlight the development of imaging and ancillary techniques that have allowed SPM to permeate many key areas of contemporary research. We begin by examining the invention of the scanning tunneling microscope (STM) by Binnig and Rohrer in 1982 and discuss how it served to team biologists with physicists to integrate high-resolution microscopy into biological science. We point to the problems of imaging nonconductive biological samples with the STM and relate how this led to the evolution of the atomic force microscope (AFM) developed by Binnig, Quate, and Gerber, in 1986. Commercialization in the late 1980s established SPM as a powerful research tool in the biological research community. Contact mode AFM imaging was soon complemented by the development of non-contact imaging modes. These non-contact modes eventually became the primary focus for further new applications including the development of fast scanning methods. The extreme sensitivity of the AFM cantilever was recognized and has been developed into applications for measuring forces required for indenting biological surfaces and breaking bonds between biomolecules. Further functional augmentation to the cantilever tip allowed development of new and emerging techniques including scanning ion-conductance microscopy (SICM), scanning electrochemical microscope (SECM), Kelvin force microscopy (KFM) and scanning near field ultrasonic holography (SNFUH).

  15. Quantitative analysis of bisphosphonates in biological samples.

    PubMed

    Lapko, Veniamin N; Miller, Patrick S; Sheldon, Curtis E; Nachi, Ridha; Kafonek, Chris J

    2014-01-01

    Bisphosphonate drugs pose significant challenges for bioanalysis due to various complicating factors. In 2006, a novel approach, utilizing 'on-column' derivatization with diazomethane, was reported that revolutionized the application of liquid-chromatography-tandem mass spectrometry to bisphosphonates bioanalysis. The methodology enables superior biological sample clean-up while transforming bisphosphonates into species amenable to liquid-chromatography-tandem mass spectrometry detection. Since then, the approach has been successfully applied to numerous bisphosphonates. The use of an alternative methylation reagent - trimethylsilyl diazomethane - for on-column derivatization has been reported recently. This review focuses on published methods utilizing on-column derivatization for bioanalysis of major bisphosphonate drugs in biological matrices. Critical points required for successful application of on-column derivatization to the bioanalysis of bisphosphonates will be discussed.

  16. [Ethical aspects of biological sample banks].

    PubMed

    Cambon-Thomsen, A; Rial-Sebbag, E

    2003-02-01

    Numerous activities in the domain of epidemiology require the constitution or the use of biological sample banks. Such biobanks raise ethical issues. A number of recommendations are applicable to this field, in France and elsewhere. Major principles applicable to biobanks include the respect of person's autonomy, the respect of human body, the respect of confidentiality. These principles are translated into practices through the following procedures: relevant information to the persons regarding their sample management prior to informed consent, opinion of an independent ethics committee, actual implementation of conditions for protecting samples and data. However, although those principles may appear quite simple and obvious, in the context of a largely international practice of research and given the large variety of biobanks, it is not always obvious for researchers to find their way. The attitudes vary between countries, there are numerous texts for various types of biobanks, the same texts raise different interpretations in different institutions, there are new ethical opinions expressed, and mainly the novelty of questions raised by the uses of samples that are possible today, especially in genetics, and were not foreseeable at the time of sampling make the field difficult in practice. This article reviews the types of biobanks, the relevant ethical issues. It also underlines the still unclear or ambiguous situations using some examples of practical situations.

  17. 40 CFR Appendix II to Subpart E of... - Sampling Tables

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 25 2014-07-01 2014-07-01 false Sampling Tables II Appendix II to Subpart E of Part 205 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) NOISE..., Subpt. E, App. II Appendix II to Subpart E of Part 205—Sampling Tables Table 1—Model Year...

  18. 40 CFR Appendix II to Subpart E of... - Sampling Tables

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 26 2013-07-01 2013-07-01 false Sampling Tables II Appendix II to Subpart E of Part 205 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) NOISE..., Subpt. E, App. II Appendix II to Subpart E of Part 205—Sampling Tables Table 1—Model Year...

  19. Measurement of NO in biological samples.

    PubMed

    Csonka, C; Páli, T; Bencsik, P; Görbe, A; Ferdinandy, P; Csont, T

    2015-03-01

    Although the physiological regulatory function of the gasotransmitter NO (a diatomic free radical) was discovered decades ago, NO is still in the frontline research in biomedicine. NO has been implicated in a variety of physiological and pathological processes; therefore, pharmacological modulation of NO levels in various tissues may have significant therapeutic value. NO is generated by NOS in most of cell types and by non-enzymatic reactions. Measurement of NO is technically difficult due to its rapid chemical reactions with a wide range of molecules, such as, for example, free radicals, metals, thiols, etc. Therefore, there are still several contradictory findings on the role of NO in different biological processes. In this review, we briefly discuss the major techniques suitable for measurement of NO (electron paramagnetic resonance, electrochemistry, fluorometry) and its derivatives in biological samples (nitrite/nitrate, NOS, cGMP, nitrosothiols) and discuss the advantages and disadvantages of each method. We conclude that to obtain a meaningful insight into the role of NO and NO modulator compounds in physiological or pathological processes, concomitant assessment of NO synthesis, NO content, as well as molecular targets and reaction products of NO is recommended.

  20. Measurement of NO in biological samples

    PubMed Central

    Csonka, C; Páli, T; Bencsik, P; Görbe, A; Ferdinandy, P; Csont, T

    2015-01-01

    Although the physiological regulatory function of the gasotransmitter NO (a diatomic free radical) was discovered decades ago, NO is still in the frontline research in biomedicine. NO has been implicated in a variety of physiological and pathological processes; therefore, pharmacological modulation of NO levels in various tissues may have significant therapeutic value. NO is generated by NOS in most of cell types and by non-enzymatic reactions. Measurement of NO is technically difficult due to its rapid chemical reactions with a wide range of molecules, such as, for example, free radicals, metals, thiols, etc. Therefore, there are still several contradictory findings on the role of NO in different biological processes. In this review, we briefly discuss the major techniques suitable for measurement of NO (electron paramagnetic resonance, electrochemistry, fluorometry) and its derivatives in biological samples (nitrite/nitrate, NOS, cGMP, nitrosothiols) and discuss the advantages and disadvantages of each method. We conclude that to obtain a meaningful insight into the role of NO and NO modulator compounds in physiological or pathological processes, concomitant assessment of NO synthesis, NO content, as well as molecular targets and reaction products of NO is recommended. Linked Articles This article is part of a themed section on Pharmacology of the Gasotransmitters. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2015.172.issue-6 PMID:24990201

  1. 40 CFR Appendix II to Subpart E - Sampling Tables

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 26 2012-07-01 2011-07-01 true Sampling Tables II Appendix II to Subpart E Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) NOISE ABATEMENT PROGRAMS... II to Subpart E—Sampling Tables Table 1—Model Year Production Volume of 50-99 Vehicles...

  2. 40 CFR Appendix II to Subpart E - Sampling Tables

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Sampling Tables II Appendix II to Subpart E Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) NOISE ABATEMENT PROGRAMS... II to Subpart E—Sampling Tables Table 1—Model Year Production Volume of 50-99 Vehicles...

  3. Determination of cadmium in biological samples.

    PubMed

    Klotz, Katrin; Weistenhöfer, Wobbeke; Drexler, Hans

    2013-01-01

    Analyses of cadmium concentrations in biological material are performed using inductively coupled plasma mass spectrometry (ICP-MS) and atomic absorption spectrometry (AAS), but also electrochemical methods, neutron activation analysis (NAA), and X-ray fluorescence spectrometry (XRF). The predominant sample matrices include blood, plasma, serum, and urine, as well as hair, saliva, and tissue of kidney cortex, lung, and liver. While cadmium in blood reveals rather the recent exposure situation, cadmium in urine reflects the body burden and is an indicator for the cumulative long term exposure.After chronic exposure, cadmium accumulates in the human body and causes kidney diseases, especially lesions of proximal tubular cells. A tubular proteinuria causes an increase in urinary excretion of microproteins. Excretions of retinol binding protein (RBP), β2-microglobulin (β2-M), and α1-microglobulin are validated biomarkers for analyzing cadmium effects. For this purpose, immunological procedures such as ELISA, and radio- and latex-immunoassays are used.However, proteinuria is not specific to cadmium, but can also occur after exposure to other nephrotoxic agents or due to various kidney diseases. In summary, cadmium in urine and blood are the most specific biomarkers of cadmium exposure. A combination of parameters of exposure (cadmium in blood, cadmium in urine) and parameters of effect (e.g., β2-M, RBP) is required to reveal cadmium-induced nephrological effects. PMID:23430771

  4. Synergistic extraction and spectrophotometric determination of copper(II) using 1-(2',4'-dinitro aminophenyl)-4,4,6-trimethyl-1,4-dihydropyrimidine-2-thiol: analysis of alloys, pharmaceuticals and biological samples.

    PubMed

    Kamble, Ganesh S; Kolekar, Sanjay S; Anuse, Mansing A

    2011-05-01

    A simple and selective spectrophotometric method was developed for the determination of copper(II) with 1-(2',4'-dinitro aminophenyl)-4,4,6-trimethyl-1,4-dihydropyrimidine-2-thiol [2',4'-dinitro APTPT] as a chromogenic reagent. The procedure was based on the synergistic extraction of copper(II) with 2',4'-dinitro APTPT in the presence of 0.5 mol L(-1) pyridine to give green colored ternary complex of a molar ratio 1:2:2 (M:L:Py) in the pH range 8.7-10.5. It exhibits a maximum absorption of colored complex at 445 nm and 645 nm in chloroform against the reagent blank. Beer's law was followed in the concentration range 10-80 μg mL(-1) of copper(II) and optimum range of 20-70 μg mL(-1) the metal as evaluated from Ringbom's plot. The molar absorptivity and Sandell's sensitivity of copper(II)-2',4'-dinitro APTPT-pyridine complex in chloroform are 0.87×10(3) L mol(-1)c m(-1) and 0.072 μg cm(-2), respectively. The interfering effects of various cations and anions were also studied, and use of suitable masking agents enhances the selectivity of the method. The proposed method is rapid, reproducible and successfully applied for the determination of copper(II) in binary and synthetic mixtures, alloys, pharmaceutical formulations, environmental and fertilizer samples. Comparison of the results with those obtained using an atomic absorption spectrophotometer also tested the validity of the method. PMID:21330190

  5. Synergistic extraction and spectrophotometric determination of copper(II) using 1-(2',4'-dinitro aminophenyl)-4,4,6-trimethyl-1,4-dihydropyrimidine-2-thiol: Analysis of alloys, pharmaceuticals and biological samples

    NASA Astrophysics Data System (ADS)

    Kamble, Ganesh S.; Kolekar, Sanjay S.; Anuse, Mansing A.

    2011-05-01

    A simple and selective spectrophotometric method was developed for the determination of copper(II) with 1-(2',4'-dinitro aminophenyl)-4,4,6-trimethyl-1,4-dihydropyrimidine-2-thiol [2',4'-dinitro APTPT] as a chromogenic reagent. The procedure was based on the synergistic extraction of copper(II) with 2',4'-dinitro APTPT in the presence of 0.5 mol L -1 pyridine to give green colored ternary complex of a molar ratio 1:2:2 (M:L:Py) in the pH range 8.7-10.5. It exhibits a maximum absorption of colored complex at 445 nm and 645 nm in chloroform against the reagent blank. Beer's law was followed in the concentration range 10-80 μg mL -1 of copper(II) and optimum range of 20-70 μg mL -1 the metal as evaluated from Ringbom's plot. The molar absorptivity and Sandell's sensitivity of copper(II)-2',4'-dinitro APTPT-pyridine complex in chloroform are 0.87 × 10 3 L mol -1 cm -1 and 0.072 μg cm -2, respectively. The interfering effects of various cations and anions were also studied, and use of suitable masking agents enhances the selectivity of the method. The proposed method is rapid, reproducible and successfully applied for the determination of copper(II) in binary and synthetic mixtures, alloys, pharmaceutical formulations, environmental and fertilizer samples. Comparison of the results with those obtained using an atomic absorption spectrophotometer also tested the validity of the method.

  6. Critical appraisal: dental amalgam update--part II: biological effects.

    PubMed

    Wahl, Michael J; Swift, Edward J

    2013-12-01

    Dental amalgam restorations have been controversial for over 150 years. In Part I of this Critical Appraisal, the clinical efficacy of dental amalgam was updated. Here in Part II, the biological effects of dental amalgam are addressed.

  7. Outdoor Biology Instructional Strategies Trial Edition. Set II.

    ERIC Educational Resources Information Center

    Fairwell, Kay, Ed.; And Others

    The 24 activities in the Outdoor Biology Instructional Strategies (OBIS) Trial Edition Set II use living organisms such as crabs, birds, crayfish, lichens, and insects to investigate biological interrelationships, organism behavior, and species density to promote greater environmental and sensory awareness. The activities, designed primarily for…

  8. COMPARISON OF BIOLOGICAL COMMUNITIES: THE PROBLEM OF SAMPLE REPRESENTATIVENESS

    EPA Science Inventory

    Obtaining an adequate, representative sample of biological communities or assemblages to make richness or compositional comparisons among sites is a continuing challenge. Traditionally, sample size is based on numbers of replicates or area collected or numbers of individuals enum...

  9. Determination of total mercury in biological and geological samples

    USGS Publications Warehouse

    Crock, James G.

    2005-01-01

    The analytical chemist is faced with several challenges when determining mercury in biological and geological materials. These challenges include widespread mercury contamination, both in the laboratory and the environment, possible losses of mercury during sample preparation and digestion, the wide range of mercury values commonly observed, ranging from the low nanogram per gram or per liter for background areas to hundreds of milligrams per kilogram in contaminated or ore-bearing areas, great matrix diversity, and sample heterogeneity1. These factors can be naturally occurring or anthropogenic, but must be addressed to provide a precise and accurate analysis. Although there are many instrumental methods available for the successful determination of mercury, no one technique will address all problems or all samples all of the time. The approach for the determination of mercury used at the U.S. Geological Survey, Crustal Imaging and Characterization Team, Denver Laboratories, utilizes a suite of complementary instrumental methods when approaching a study requiring mercury analyses. Typically, a study could require the analysis of waters, leachates or selective digestions of solids, vegetation, and biological materials such as tissue, bone, or shell, soils, rocks, sediments, coals, sludges, and(or) ashes. No one digestion or sample preparation method will be suitable for all of these matrices. The digestions typically employed at our laboratories include: (i) a closed-vessel microwave method using nitric acid and hydrogen peroxide, followed by digestion/dilution with a nitric acid/sodium dichromate solution, (ii) a robotic open test-tube digestion with nitric acid and sodium dichromate, (iii) a sealed Teflon? vessel with nitric acid and sodium dichromate, (iv) a sealed glass bottle with nitric acid and sodium dichromate, or (v) open test tube digestion with nitric and sulfuric acids and vanadium pentoxide. The common factor in all these digestions is that they are

  10. How to analyze those messy biological samples

    SciTech Connect

    Barker, S.A. . Dept. of Veterinary Physiology, Pharmacology, and Toxicology)

    1993-03-01

    Extracting drugs, pollutants, or naturally occurring components from tissues is always an analytical challenge. However, there is an increasing need to perform such extractions for the regulation of food safety, the determination of the degree or nature of pollution in various environments, or to isolate a particular class of structural components from cells. The samples may range from blood to whole oysters, milk to fish, calf's liver to crayfish, or beef to bacteria. The author has developed a generic process that greatly simplifies and speeds the isolation of drugs, pollutants, and biomolecules from tissues, bacteria, and processed foods. This process, called matrix solid-phase dispersion (MSPD; patent pending), allows the analyst to perform sample homogenization, cellular disruption, and sample purification in a single step. The methods that they have developed have shown to reduce solvent usage by 90% and analyst time by 95% when compared with classical procedures for drug isolations from tissue.

  11. Rapid Automated Sample Preparation for Biological Assays

    SciTech Connect

    Shusteff, M

    2011-03-04

    Our technology utilizes acoustic, thermal, and electric fields to separate out contaminants such as debris or pollen from environmental samples, lyse open cells, and extract the DNA from the lysate. The objective of the project is to optimize the system described for a forensic sample, and demonstrate its performance for integration with downstream assay platforms (e.g. MIT-LL's ANDE). We intend to increase the quantity of DNA recovered from the sample beyond the current {approx}80% achieved using solid phase extraction methods. Task 1: Develop and test an acoustic filter for cell extraction. Task 2: Develop and test lysis chip. Task 3: Develop and test DNA extraction chip. All chips have been fabricated based on the designs laid out in last month's report.

  12. 9 CFR 113.3 - Sampling of biological products.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... samples of each serial or subserial of a biological product manufactured in the United States or imported... filling operation. (iv) Representative samples of each serial or subserial in each shipment of imported... such samples from each serial and the minimum quantity of product to be provided in each sample...

  13. 40 CFR Appendix II to Subpart E - Sampling Tables

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Subpart E Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) NOISE ABATEMENT PROGRAMS TRANSPORTATION EQUIPMENT NOISE EMISSION CONTROLS Motorcycle Exhaust Systems Pt. 205, Subpt. E, App. II Appendix II to Subpart E—Sampling Tables Table 1—Model Year Production Volume of 50-99 Vehicles...

  14. A sample of Type II-L supernovae

    NASA Astrophysics Data System (ADS)

    Faran, T.; Poznanski, D.; Filippenko, A. V.; Chornock, R.; Foley, R. J.; Ganeshalingam, M.; Leonard, D. C.; Li, W.; Modjaz, M.; Serduke, F. J. D.; Silverman, J. M.

    2014-11-01

    What are Type II-Linear supernovae (SNe II-L)? This class, which has been ill defined for decades, now receives significant attention - both theoretically, in order to understand what happens to stars in the ˜15-25 M⊙ range, and observationally, with two independent studies suggesting that they cannot be cleanly separated photometrically from the regular hydrogen-rich SNe II-P characterized by a marked plateau in their light curve. Here, we analyse the multiband light curves and extensive spectroscopic coverage of a sample of 35 SNe II and find that 11 of them could be SNe II-L. The spectra of these SNe are hydrogen deficient, typically have shallow Hα absorption, may show indirect signs of helium via strong O I λ7774 absorption, and have faster line velocities consistent with a thin hydrogen shell. The light curves can be mostly differentiated from those of the regular, hydrogen-rich SNe II-P by their steeper decline rates and higher luminosity, and we propose to define them based on their decline in the V band: SNe II-L decline by more than 0.5 mag from peak brightness by day 50 after explosion. Using our sample we provide template light curves for SNe II-L and II-P in four photometric bands.

  15. Adaptive fractionation therapy: II. Biological effective dose

    NASA Astrophysics Data System (ADS)

    Chen, Mingli; Lu, Weiguo; Chen, Quan; Ruchala, Kenneth; Olivera, Gustavo

    2008-10-01

    Radiation therapy is fractionized to differentiate the cell killing between the tumor and organ at risk (OAR). Conventionally, fractionation is done by dividing the total dose into equal fraction sizes. However, as the relative positions (configurations) between OAR and the tumor vary from fractions to fractions, intuitively, we want to use a larger fraction size when OAR and the tumor are far apart and a smaller fraction size when OAR and the tumor are close to each other. Adaptive fractionation accounts for variations of configurations between OAR and the tumor. In part I of this series, the adaptation minimizes the OAR (physical) dose and maintains the total tumor (physical) dose. In this work, instead, the adaptation is based on the biological effective dose (BED). Unlike the linear programming approach in part I, we build a fraction size lookup table using mathematical induction. The lookup table essentially describes the fraction size as a function of the remaining tumor BED, the OAR/tumor dose ratio and the remaining number of fractions. The lookup table is calculated by maximizing the expected survival of OAR and preserving the tumor cell kill. Immediately before the treatment of each fraction, the OAR-tumor configuration and thus the dose ratio can be obtained from the daily setup image, and then the fraction size can be determined by the lookup table. Extensive simulations demonstrate the effectiveness of our method compared with the conventional fractionation method.

  16. Observation of biological samples using a scanning microwave microscope.

    PubMed

    Park, Jewook; Hyun, S; Kim, A; Kim, T; Char, K

    2005-01-01

    We present the application of a scanning microwave microscope technique to biological samples. Since dielectric properties of most biological samples originate mainly from the water they contain, we were able to obtain microscope images of biological samples by our scanning microwave microscope technique. As a model system, we have measured the electrical properties of water in the microwave region. The high dielectric constant and the large loss tangent of water were verified. Furthermore, we have measured the properties of water with differing amounts of sodium chloride concentration ranging from de-ionized water to the saturated solution. We have observed a significant change in the resonant frequency and Q value of the resonator as a function of sodium chloride concentration. The concentration dependence of the signals shows that our scanning microwave microscope technique can be useful for investigating the local electric behavior of biological samples with a simple model of ionic conduction.

  17. The molecular biology of WHO grade II gliomas.

    PubMed

    Marko, Nicholas F; Weil, Robert J

    2013-02-01

    The WHO grading scheme for glial neoplasms assigns Grade II to 5 distinct tumors of astrocytic or oligodendroglial lineage: diffuse astrocytoma, oligodendroglioma, oligoastrocytoma, pleomorphic xanthoastrocytoma, and pilomyxoid astrocytoma. Although commonly referred to collectively as among the "low-grade gliomas," these 5 tumors represent molecularly and clinically unique entities. Each is the subject of active basic research aimed at developing a more complete understanding of its molecular biology, and the pace of such research continues to accelerate. Additionally, because managing and predicting the course of these tumors has historically proven challenging, translational research regarding Grade II gliomas continues in the hopes of identifying novel molecular features that can better inform diagnostic, prognostic, and therapeutic strategies. Unfortunately, the basic and translational literature regarding the molecular biology of WHO Grade II gliomas remains nebulous. The authors' goal for this review was to present a comprehensive discussion of current knowledge regarding the molecular characteristics of these 5 WHO Grade II tumors on the chromosomal, genomic, and epigenomic levels. Additionally, they discuss the emerging evidence suggesting molecular differences between adult and pediatric Grade II gliomas. Finally, they present an overview of current strategies for using molecular data to classify low-grade gliomas into clinically relevant categories based on tumor biology.

  18. Column solid phase extraction and flame atomic absorption spectrometric determination of manganese(II) and iron(III) ions in water, food and biological samples using 3-(1-methyl-1H-pyrrol-2-yl)-1H-pyrazole-5-carboxylic acid on synthesized graphene oxide.

    PubMed

    Pourjavid, Mohammad Reza; Sehat, Ali Akbari; Arabieh, Masoud; Yousefi, Seyed Reza; Hosseini, Majid Haji; Rezaee, Mohammad

    2014-02-01

    A modified, selective, highly sensitive and accurate procedure for the determination of trace amounts of manganese and iron ions is established in the presented work. 3-(1-Methyl-1H-pyrrol-2-yl)-1H-pyrazole-5-carboxylic acid (MPPC) and graphene oxide (GO) were used in a glass column as chelating reagent and as adsorbent respectively prior to their determination by flame atomic absorption spectrometry. The adsorption mechanism of titled metals complexes on GO was investigated by using computational chemistry approach based on PM6 semi-empirical potential energy surface (PES). The effect of some parameters including pH, flow rate and volume of sample and type, volume and concentration of eluent, as well as the adsorption capacity of matrix ions on the recovery of Mn(II) and Fe(III) was investigated. The limit of detection was 145 and 162 ng L(-1) for Mn(II) and Fe(III), respectively. Calibration was linear over the range of 0.31-355 μg L(-1) for Mn(II) and 0.34-380 μg L(-1) for Fe(III) ions. The method was successfully applied for the determination of understudied ions in water, food and biological samples.

  19. Advances in imaging secondary ion mass spectrometry for biological samples

    SciTech Connect

    Boxer, Steven G.; Kraft, Mary L.; Weber, Peter K.

    2008-12-16

    Imaging mass spectrometry combines the power of mass spectrometry to identify complex molecules based on mass with sample imaging. Recent advances in secondary ion mass spectrometry have improved sensitivity and spatial resolution, so that these methods have the potential to bridge between high-resolution structures obtained by X-ray crystallography and cyro-electron microscopy and ultrastructure visualized by conventional light microscopy. Following background information on the method and instrumentation, we address the key issue of sample preparation. Because mass spectrometry is performed in high vacuum, it is essential to preserve the lateral organization of the sample while removing bulk water, and this has been a major barrier for applications to biological systems. Furthermore, recent applications of imaging mass spectrometry to cell biology, microbial communities, and biosynthetic pathways are summarized briefly, and studies of biological membrane organization are described in greater depth.

  20. Advances in imaging secondary ion mass spectrometry for biological samples

    DOE PAGESBeta

    Boxer, Steven G.; Kraft, Mary L.; Weber, Peter K.

    2008-12-16

    Imaging mass spectrometry combines the power of mass spectrometry to identify complex molecules based on mass with sample imaging. Recent advances in secondary ion mass spectrometry have improved sensitivity and spatial resolution, so that these methods have the potential to bridge between high-resolution structures obtained by X-ray crystallography and cyro-electron microscopy and ultrastructure visualized by conventional light microscopy. Following background information on the method and instrumentation, we address the key issue of sample preparation. Because mass spectrometry is performed in high vacuum, it is essential to preserve the lateral organization of the sample while removing bulk water, and this hasmore » been a major barrier for applications to biological systems. Furthermore, recent applications of imaging mass spectrometry to cell biology, microbial communities, and biosynthetic pathways are summarized briefly, and studies of biological membrane organization are described in greater depth.« less

  1. Home Economics. Sample Test Items. Levels I and II.

    ERIC Educational Resources Information Center

    New York State Education Dept., Albany. Bureau of Elementary and Secondary Educational Testing.

    A sample of behavioral objectives and related test items that could be developed for content modules in Home Economics levels I and II, this book is intended to enable teachers to construct more valid and reliable test materials. Forty-eight one-page modules are presented, and opposite each module are listed two to seven specific behavioral…

  2. Amchitka Island, Alaska, Biological Monitoring Report 2011 Sampling Results

    SciTech Connect

    2013-09-01

    The Long-Term Surveillance and Maintenance (LTS&M) Plan for the U.S. Department of Energy (DOE) Office of Legacy Management (LM) Amchitka Island sites describes how LM plans to conduct its mission to protect human health and the environment at the three nuclear test sites located on Amchitka Island, Alaska. Amchitka Island, near the western end of the Aleutian Islands, is approximately 1,340 miles west-southwest of Anchorage, Alaska. Amchitka is part of the Aleutian Island Unit of the Alaska Maritime National Wildlife Refuge, which is administered by the U.S. Fish and Wildlife Service (USFWS). Since World War II, Amchitka has been used by multiple U.S. government agencies for various military and research activities. From 1943 to 1950, it was used as a forward air base for the U.S. Armed Forces. During the middle 1960s and early 1970s, the U.S. Department of Defense (DOD) and the U.S. Atomic Energy Commission (AEC) used a portion of the island as a site for underground nuclear tests. During the late 1980s and early 1990s, the U.S. Navy constructed and operated a radar station on the island. Three underground nuclear tests were conducted on Amchitka Island. DOD, in conjunction with AEC, conducted the first nuclear test (named Long Shot) in 1965 to provide data that would improve the United States' capability of detecting underground nuclear explosions. The second nuclear test (Milrow) was a weapons-related test conducted by AEC in 1969 as a means to study the feasibility of detonating a much larger device. Cannikin, the third nuclear test on Amchitka, was a weapons-related test detonated on November 6, 1971. With the exception of small concentrations of tritium detected in surface water shortly after the Long Shot test, radioactive fission products from the tests remain in the subsurface at each test location As a continuation of the environmental monitoring that has taken place on Amchitka Island since before 1965, LM in the summer of 2011 collected biological and

  3. Fast X-Ray Fluorescence Microtomography of Hydrated Biological Samples

    PubMed Central

    Lombi, Enzo; de Jonge, Martin D.; Donner, Erica; Kopittke, Peter M.; Howard, Daryl L.; Kirkham, Robin; Ryan, Chris G.; Paterson, David

    2011-01-01

    Metals and metalloids play a key role in plant and other biological systems as some of them are essential to living organisms and all can be toxic at high concentrations. It is therefore important to understand how they are accumulated, complexed and transported within plants. In situ imaging of metal distribution at physiological relevant concentrations in highly hydrated biological systems is technically challenging. In the case of roots, this is mainly due to the possibility of artifacts arising during sample preparation such as cross sectioning. Synchrotron x-ray fluorescence microtomography has been used to obtain virtual cross sections of elemental distributions. However, traditionally this technique requires long data acquisition times. This has prohibited its application to highly hydrated biological samples which suffer both radiation damage and dehydration during extended analysis. However, recent advances in fast detectors coupled with powerful data acquisition approaches and suitable sample preparation methods can circumvent this problem. We demonstrate the heightened potential of this technique by imaging the distribution of nickel and zinc in hydrated plant roots. Although 3D tomography was still impeded by radiation damage, we successfully collected 2D tomograms of hydrated plant roots exposed to environmentally relevant metal concentrations for short periods of time. To our knowledge, this is the first published example of the possibilities offered by a new generation of fast fluorescence detectors to investigate metal and metalloid distribution in radiation-sensitive, biological samples. PMID:21674049

  4. Fast x-ray fluorescence microtomography of hydrated biological samples.

    PubMed

    Lombi, Enzo; de Jonge, Martin D; Donner, Erica; Kopittke, Peter M; Howard, Daryl L; Kirkham, Robin; Ryan, Chris G; Paterson, David

    2011-01-01

    Metals and metalloids play a key role in plant and other biological systems as some of them are essential to living organisms and all can be toxic at high concentrations. It is therefore important to understand how they are accumulated, complexed and transported within plants. In situ imaging of metal distribution at physiological relevant concentrations in highly hydrated biological systems is technically challenging. In the case of roots, this is mainly due to the possibility of artifacts arising during sample preparation such as cross sectioning. Synchrotron x-ray fluorescence microtomography has been used to obtain virtual cross sections of elemental distributions. However, traditionally this technique requires long data acquisition times. This has prohibited its application to highly hydrated biological samples which suffer both radiation damage and dehydration during extended analysis. However, recent advances in fast detectors coupled with powerful data acquisition approaches and suitable sample preparation methods can circumvent this problem. We demonstrate the heightened potential of this technique by imaging the distribution of nickel and zinc in hydrated plant roots. Although 3D tomography was still impeded by radiation damage, we successfully collected 2D tomograms of hydrated plant roots exposed to environmentally relevant metal concentrations for short periods of time. To our knowledge, this is the first published example of the possibilities offered by a new generation of fast fluorescence detectors to investigate metal and metalloid distribution in radiation-sensitive, biological samples. PMID:21674049

  5. Efficient Sample Preparation from Complex Biological Samples Using a Sliding Lid for Immobilized Droplet Extractions

    PubMed Central

    2015-01-01

    Sample preparation is a major bottleneck in many biological processes. Paramagnetic particles (PMPs) are a ubiquitous method for isolating analytes of interest from biological samples and are used for their ability to thoroughly sample a solution and be easily collected with a magnet. There are three main methods by which PMPs are used for sample preparation: (1) removal of fluid from the analyte-bound PMPs, (2) removal of analyte-bound PMPs from the solution, and (3) removal of the substrate (with immobilized analyte-bound PMPs). In this paper, we explore the third and least studied method for PMP-based sample preparation using a platform termed Sliding Lid for Immobilized Droplet Extractions (SLIDE). SLIDE leverages principles of surface tension and patterned hydrophobicity to create a simple-to-operate platform for sample isolation (cells, DNA, RNA, protein) and preparation (cell staining) without the need for time-intensive wash steps, use of immiscible fluids, or precise pinning geometries. Compared to other standard isolation protocols using PMPs, SLIDE is able to perform rapid sample preparation with low (0.6%) carryover of contaminants from the original sample. The natural recirculation occurring within the pinned droplets of SLIDE make possible the performance of multistep cell staining protocols within the SLIDE by simply resting the lid over the various sample droplets. SLIDE demonstrates a simple easy to use platform for sample preparation on a range of complex biological samples. PMID:24927449

  6. Development of an on-line preconcentration system for zinc determination in biological samples.

    PubMed

    Dutra, Rosilene L; Maltez, Heloisa F; Carasek, Eduardo

    2006-04-15

    An on-line preconcentration system for zinc determination in 24-h urine, blood plasma and erythrocyte matrices by flame atomic absorption spectrometry (FAAS) was used. This procedure was based on adsorption of Zn(II) ions onto a minicolumn filled with silica gel, chemically modified with niobium(V) oxide (Nb(2)O(5)-SiO(2)). The determination of the optimum conditions for Zn(II) preconcentration was done using two-level full factorial and Doehlert designs. In the optimization procedure, four variables (sample pH, eluent concentration, sample flow rate and eluent flow rate) were investigated. The results obtained from the full factorial design demonstrated that the sample pH and sample flow rate variables, and their interactions, were statistically significant. A Doehlert matrix was used in order to determine the optimum conditions for the sample pH and sample flow rate. The optimized conditions for sample pH and flow rate sampling were 6.6 and 7.1 ml min(-1), respectively, to obtain the maximum Zn(II) preconcentration and determination in the biological samples studied. Parameters of analytical curve, precision, effect of other ions in the proposed system and accuracy were achieved to assess the proposed method. The accuracy was confirmed by analysis of certified reference materials (urine Seronorm Trace Elements) and recovery tests in blood plasma and erythrocyte samples. Detection limit (3sigma/S) of 0.77 microg l(-1), precision (calculated as relative standard deviation) of 1.5% for Zn(II) concentration of 10 microg l(-1) (n=7) and a sampling frequency of 27 samples/h were obtained from the proposed system. PMID:18970593

  7. A large-scale cryoelectronic system for biological sample banking

    NASA Astrophysics Data System (ADS)

    Shirley, Stephen G.; Durst, Christopher H. P.; Fuchs, Christian C.; Zimmermann, Heiko; Ihmig, Frank R.

    2009-11-01

    We describe a polymorphic electronic infrastructure for managing biological samples stored over liquid nitrogen. As part of this system we have developed new cryocontainers and carrier plates attached to Flash memory chips to have a redundant and portable set of data at each sample. Our experimental investigations show that basic Flash operation and endurance is adequate for the application down to liquid nitrogen temperatures. This identification technology can provide the best sample identification, documentation and tracking that brings added value to each sample. The first application of the system is in a worldwide collaborative research towards the production of an AIDS vaccine. The functionality and versatility of the system can lead to an essential optimization of sample and data exchange for global clinical studies.

  8. Cryogenic X-ray Diffraction Microscopy for Biological Samples

    SciTech Connect

    E Lima; L Wiegart; P Pernot; M Howells; J Timmins; F Zontone; A Madsen

    2011-12-31

    X-ray diffraction microscopy (XDM) is well suited for nondestructive, high-resolution biological imaging, especially for thick samples, with the high penetration power of x rays and without limitations imposed by a lens. We developed nonvacuum, cryogenic (cryo-) XDM with hard x rays at 8 keV and report the first frozen-hydrated imaging by XDM. By preserving samples in amorphous ice, the risk of artifacts associated with dehydration or chemical fixation is avoided, ensuring the imaging condition closest to their natural state. The reconstruction shows internal structures of intact D. radiodurans bacteria in their natural contrast.

  9. Analytical methodologies for the determination of benzodiazepines in biological samples.

    PubMed

    Persona, Karolina; Madej, Katarzyna; Knihnicki, Paweł; Piekoszewski, Wojciech

    2015-09-10

    Benzodiazepine drugs belong to important and most widely used medicaments. They demonstrate such therapeutic properties as anxiolytic, sedative, somnifacient, anticonvulsant, diastolic and muscle relaxant effects. However, despite the fact that benzodiazepines possess high therapeutic index and are considered to be relatively safe, their use can be dangerous when: (1) co-administered with alcohol, (2) co-administered with other medicaments like sedatives, antidepressants, neuroleptics or morphine like substances, (3) driving under their influence, (4) using benzodiazepines non-therapeutically as drugs of abuse or in drug-facilitated crimes. For these reasons benzodiazepines are still studied and determined in a variety of biological materials. In this article, sample preparation techniques which have been applied in analysis of benzodiazepine drugs in biological samples have been reviewed and presented. The next part of the article is focused on a review of analytical methods which have been employed for pharmacological, toxicological or forensic study of this group of drugs in the biological matrices. The review was preceded by a description of the physicochemical properties of the selected benzodiazepines and two, very often coexisting in the same analyzed samples, sedative-hypnotic drugs.

  10. 7 CFR 42.110 - Sampling plans for tightened condition of container inspection; Tables II and II-A.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false Sampling plans for tightened condition of container... Procedures for Stationary Lot Sampling and Inspection § 42.110 Sampling plans for tightened condition of container inspection; Tables II and II-A. Table II—Single Sampling Plans for Tightened Condition...

  11. Specific fluorogenic probes for ozone in biological and atmospheric samples.

    PubMed

    Garner, Amanda L; St Croix, Claudette M; Pitt, Bruce R; Leikauf, George D; Ando, Shin; Koide, Kazunori

    2009-07-01

    Ozone exposure is a growing global health problem, especially in urban areas. While ozone in the stratosphere protects the earth from harmful ultraviolet light, tropospheric or ground-level ozone is toxic and can damage the respiratory tract. It has recently been shown that ozone may be produced endogenously in inflammation and antibacterial responses of the immune system; however, these results have sparked controversy owing to the use of a non-specific colorimetric probe. Here we report the synthesis of fluorescent molecular probes able to unambiguously detect ozone in both biological and atmospheric samples. Unlike other ozone-detection methods, in which interference from different reactive oxygen species is often a problem, these probes are ozone specific. Such probes will prove useful for the study of ozone in environmental science and biology, and so possibly provide some insight into the role of ozone in cells.

  12. Specific fluorogenic probes for ozone in biological and atmospheric samples

    PubMed Central

    Garner, Amanda L.; St Croix, Claudette M.; Pitt, Bruce R.; Leikauf, George D.; Ando, Shin; Koide, Kazunori

    2010-01-01

    Ozone exposure is a growing global health problem, especially in urban areas. While ozone in the stratosphere protects the earth from harmful ultraviolet light, tropospheric or ground-level ozone is toxic and can damage the respiratory tract. It has recently been shown that ozone may be produced endogenously in inflammation and antibacterial responses of the immune system; however, these results have sparked controversy owing to the use of a non-specific colorimetric probe. Here we report the synthesis of fluorescent molecular probes able to unambiguously detect ozone in both biological and atmospheric samples. Unlike other ozone-detection methods, in which interference from different reactive oxygen species is often a problem, these probes are ozone specific. Such probes will prove useful for the study of ozone in environmental science and biology, and so possibly provide some insight into the role of ozone in cells. PMID:20634904

  13. DUS II SOIL GAS SAMPLING AND AIR INJECTION TEST RESULTS

    SciTech Connect

    Noonkester, J.; Jackson, D.; Jones, W.; Hyde, W.; Kohn, J.; Walker, R.

    2012-09-20

    Soil vapor extraction (SVE) and air injection well testing was performed at the Dynamic Underground Stripping (DUS) site located near the M-Area Settling Basin (referred to as DUS II in this report). The objective of this testing was to determine the effectiveness of continued operation of these systems. Steam injection ended on September 19, 2009 and since this time the extraction operations have utilized residual heat that is present in the subsurface. The well testing campaign began on June 5, 2012 and was completed on June 25, 2012. Thirty-two (32) SVE wells were purged for 24 hours or longer using the active soil vapor extraction (ASVE) system at the DUS II site. During each test five or more soil gas samples were collected from each well and analyzed for target volatile organic compounds (VOCs). The DUS II site is divided into four parcels (see Figure 1) and soil gas sample results show the majority of residual VOC contamination remains in Parcel 1 with lesser amounts in the other three parcels. Several VOCs, including tetrachloroethylene (PCE) and trichloroethylene (TCE), were detected. PCE was the major VOC with lesser amounts of TCE. Most soil gas concentrations of PCE ranged from 0 to 60 ppmv with one well (VEW-22A) as high as 200 ppmv. Air sparging (AS) generally involves the injection of air into the aquifer through either vertical or horizontal wells. AS is coupled with SVE systems when contaminant recovery is necessary. While traditional air sparging (AS) is not a primary component of the DUS process, following the cessation of steam injection, eight (8) of the sixty-three (63) steam injection wells were used to inject air. These wells were previously used for hydrous pyrolysis oxidation (HPO) as part of the DUS process. Air sparging is different from the HPO operations in that the air was injected at a higher rate (20 to 50 scfm) versus HPO (1 to 2 scfm). . At the DUS II site the air injection wells were tested to determine if air sparging affected

  14. Electrochemical cells for voltammetry, coulometry, and protein activity assays of small-volume biological samples.

    PubMed

    Feldman, B J; Gheller, S F; Bailey, G F; Newton, W E; Schultz, F A

    1990-02-15

    Cell designs, experimental protocols, and results for electrochemical investigation of small quantitites of biological materials under anaerobic conditions are reported. Three types of electrochemical experiments are considered: (i) cyclic voltammetry of 20- to 100-microliters samples; (ii) direct coulometry of 0.5- to 1.5-ml samples; and (iii) an electrochemically initiated protein activity assay which includes provision for analysis of gaseous reaction products and correlation with electron flux. The first two procedures are illustrated by measurement of the formal electrode potential (E0') and number of electrons transferred (n) in redox reactions of small quantities of biological and inorganic materials. The third procedure is illustrated by assaying the activity of the MoFe protein plus Fe protein complex from Azotobacter vinelandii nitrogenase for reduction of C2H2 to C2H4.

  15. Consistency of ARESE II Cloud Absorption Estimates and Sampling Issues

    NASA Technical Reports Server (NTRS)

    Oreopoulos, L.; Marshak, A.; Cahalan, R. F.; Lau, William K. M. (Technical Monitor)

    2002-01-01

    Data from three cloudy days (March 3, 21, 29, 2000) of the ARM Enhanced Shortwave Experiment II (ARESE II) were analyzed. Grand averages of broadband absorptance among three sets of instruments were compared. Fractional solar absorptances were approx. 0.21-0.22 with the exception of March 3 when two sets of instruments gave values smaller by approx. 0.03-0.04. The robustness of these values was investigated by looking into possible sampling problems with the aid of 500 nm spectral fluxes. Grand averages of 500 nm apparent absorptance cover a wide range of values for these three days, namely from a large positive (approx. 0.011) average for March 3, to a small negative (approximately -0.03) for March 21, to near zero (approx. 0.01) for March 29. We present evidence suggesting that a large part of the discrepancies among the three days is due to the different nature of clouds and their non-uniform sampling. Hence, corrections to the grand average broadband absorptance values may be necessary. However, application of the known correction techniques may be precarious due to the sparsity of collocated flux measurements above and below the clouds. Our analysis leads to the conclusion that only March 29 fulfills all requirements for reliable estimates of cloud absorption, that is, the presence of thick, overcast, homogeneous clouds.

  16. A low temperature scanning force microscope for biological samples

    SciTech Connect

    Gustafsson, M. G.L.

    1993-05-01

    An SFM has been constructed capable of operating at 143 K. Two contributions to SFM technology are described: a new method of fabricating tips, and new designs of SFM springs that significantly lower the noise level. The SFM has been used to image several biological samples (including collagen, ferritin, RNA, purple membrane) at 143 K and room temperature. No improvement in resolution resulted from 143 K operation; several possible reasons for this are discussed. Possibly sharper tips may help. The 143 K SFM will allow the study of new categories of samples, such as those prepared by freeze-frame, single molecules (temperature dependence of mechanical properties), etc. The SFM was used to cut single collagen molecules into segments with a precision of {le} 10 nm.

  17. Microsystem strategies for sample preparation in biological detection.

    SciTech Connect

    James, Conrad D.; Galambos, Paul C.; Bennett, Dawn Jonita; Manginell, Monica; Okandan, Murat; Acrivos, Andreas; Brozik, Susan Marie; Khusid, Boris

    2005-03-01

    The objective of this LDRD was to develop microdevice strategies for dealing with samples to be examined in biological detection systems. This includes three sub-components: namely, microdevice fabrication, sample delivery to the microdevice, and sample processing within the microdevice. The first component of this work focused on utilizing Sandia's surface micromachining technology to fabricate small volume (nanoliter) fluidic systems for processing small quantities of biological samples. The next component was to develop interfaces for the surface-micromachined silicon devices. We partnered with Micronics, a commercial company, to produce fluidic manifolds for sample delivery to our silicon devices. Pressure testing was completed to examine the strength of the bond between the pressure-sensitive adhesive layer and the silicon chip. We are also pursuing several other methods, both in house and external, to develop polymer-based fluidic manifolds for packaging silicon-based microfluidic devices. The second component, sample processing, is divided into two sub-tasks: cell collection and cell lysis. Cell collection was achieved using dielectrophoresis, which employs AC fields to collect cells at energized microelectrodes, while rejecting non-cellular particles. Both live and dead Staph. aureus bacteria have been collected using RF frequency dielectrophoresis. Bacteria have been separated from polystyrene microspheres using frequency-shifting dielectrophoresis. Computational modeling was performed to optimize device separation performance, and to predict particle response to the dielectrophoretic traps. Cell lysis is continuing to be pursued using microactuators to mechanically disrupt cell membranes. Novel thermal actuators, which can generate larger forces than previously tested electrostatic actuators, have been incorporated with and tested with cell lysis devices. Significant cell membrane distortion has been observed, but more experiments need to be conducted to

  18. Proteomic Challenges: Sample Preparation Techniques for Microgram-Quantity Protein Analysis from Biological Samples

    PubMed Central

    Feist, Peter; Hummon, Amanda B.

    2015-01-01

    Proteins regulate many cellular functions and analyzing the presence and abundance of proteins in biological samples are central focuses in proteomics. The discovery and validation of biomarkers, pathways, and drug targets for various diseases can be accomplished using mass spectrometry-based proteomics. However, with mass-limited samples like tumor biopsies, it can be challenging to obtain sufficient amounts of proteins to generate high-quality mass spectrometric data. Techniques developed for macroscale quantities recover sufficient amounts of protein from milligram quantities of starting material, but sample losses become crippling with these techniques when only microgram amounts of material are available. To combat this challenge, proteomicists have developed micro-scale techniques that are compatible with decreased sample size (100 μg or lower) and still enable excellent proteome coverage. Extraction, contaminant removal, protein quantitation, and sample handling techniques for the microgram protein range are reviewed here, with an emphasis on liquid chromatography and bottom-up mass spectrometry-compatible techniques. Also, a range of biological specimens, including mammalian tissues and model cell culture systems, are discussed. PMID:25664860

  19. Constructing mock catalogues for the REFLEX II galaxy cluster sample

    NASA Astrophysics Data System (ADS)

    Balaguera-Antolínez, A.; Sánchez, Ariel G.; Böhringer, H.; Collins, C.

    2012-09-01

    We describe the construction of a suite of galaxy cluster mock catalogues from N-body simulations, based on the properties of the new ROSAT-ESO Flux Limited X-Ray (REFLEX II) galaxy cluster catalogue. Our procedure is based on the measurements of the cluster abundance, and involves the calibration of the underlying scaling relation linking the mass of dark matter haloes to the cluster X-ray luminosity determined in the ROSAT energy band 0.1-2.4 keV. In order to reproduce the observed abundance in the luminosity range probed by the REFLEX II X-ray luminosity function [0.01 < LX/(1044 erg s-1 h-2) < 10], a mass-X-ray luminosity relation deviating from a simple power law is required. We discuss the dependence of the calibration of this scaling relation on the X-ray luminosity and the definition of halo masses and analyse the one- and two-point statistical properties of the mock catalogues. Our set of mock catalogues provides samples with self-calibrated scaling relations of galaxy clusters together with inherent properties of flux-limited surveys. This makes them a useful tool to explore different systematic effects and statistical methods involved in constraining both astrophysical and cosmological information from present and future galaxy cluster surveys.

  20. Comparative analysis of toxin detection in biological and enviromental samples

    NASA Astrophysics Data System (ADS)

    Ogert, Robert A.; Burans, James; O'Brien, Tom; Ligler, Frances S.

    1994-03-01

    The basic recognition schemes underlying the principles of standard enzyme-linked immunosorbent assay (ELISA) and radioimmunoassay (RIA) protocols are increasingly being adapted for use with new detection devices. A direct comparison was made using a fiber optic biosensor that employs evanescent wave detection and an ELISA using avidin-biotin. The assays were developed for the detection of Ricinus communis agglutinin II, also known as ricin or RCA60. Detection limits between the two methods were comparable for ricin in phosphate buffered saline (PBS), however results in complex samples differed slightly. In PBS, sensitivity for ricin was 1 ng/ml using the fiber optic device and 500 pg/ml using the ELISA. The fiber optic sensor could not detect ricin directly in urine or serum spiked with 5 ng/ml ricin, however, the ELISA showed detection but at reduced levels to the PBS control.

  1. 40 CFR Appendix II to Part 600 - Sample Fuel Economy Calculations

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 30 2014-07-01 2014-07-01 false Sample Fuel Economy Calculations II... FUEL ECONOMY AND GREENHOUSE GAS EXHAUST EMISSIONS OF MOTOR VEHICLES Pt. 600, App. II Appendix II to Part 600—Sample Fuel Economy Calculations (a) This sample fuel economy calculation is applicable...

  2. 40 CFR Appendix II to Part 600 - Sample Fuel Economy Calculations

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 31 2013-07-01 2013-07-01 false Sample Fuel Economy Calculations II... FUEL ECONOMY AND GREENHOUSE GAS EXHAUST EMISSIONS OF MOTOR VEHICLES Pt. 600, App. II Appendix II to Part 600—Sample Fuel Economy Calculations (a) This sample fuel economy calculation is applicable...

  3. 40 CFR Appendix II to Part 600 - Sample Fuel Economy Calculations

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 30 2011-07-01 2011-07-01 false Sample Fuel Economy Calculations II... FUEL ECONOMY AND CARBON-RELATED EXHAUST EMISSIONS OF MOTOR VEHICLES Pt. 600, App. II Appendix II to Part 600—Sample Fuel Economy Calculations (a) This sample fuel economy calculation is applicable...

  4. 40 CFR Appendix II to Part 600 - Sample Fuel Economy Calculations

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 31 2012-07-01 2012-07-01 false Sample Fuel Economy Calculations II... FUEL ECONOMY AND GREENHOUSE GAS EXHAUST EMISSIONS OF MOTOR VEHICLES Pt. 600, App. II Appendix II to Part 600—Sample Fuel Economy Calculations (a) This sample fuel economy calculation is applicable...

  5. 40 CFR Appendix II to Part 600 - Sample Fuel Economy Calculations

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Sample Fuel Economy Calculations II... FUEL ECONOMY AND CARBON-RELATED EXHAUST EMISSIONS OF MOTOR VEHICLES Pt. 600, App. II Appendix II to Part 600—Sample Fuel Economy Calculations (a) This sample fuel economy calculation is applicable...

  6. Application of Acoustic Techniques for Characterization of Biological Samples

    NASA Astrophysics Data System (ADS)

    Tittmann, Bernhard R.; Ebert, Anne

    The atomic force microscope (AFM) is emerging as a powerful tool in cell biology. Originally developed for high-resolution imaging purposes, the AFM also has unique capabilities as a nano-indenter to probe the dynamic viscoelastic material properties of living cells in culture. In particular, AFM elastography combines imaging and indentation modalities to map the spatial distribution of cell mechanical properties, which in turn reflect the structure and function of the underlying cytoskeleton. Such measurements have contributed to our understanding of cell mechanics and cell biology and appear to be sensitive to the presence of disease in individual cells. Examples of applications and considerations on the effective capability of ultrasonic AFM techniques on biological samples (both mammalian and plant) are reported in this chapter. Included in the discussion is scanning near-field ultrasound holography an acoustic technique which has been used to image structure and in particular nanoparticles inside cells. For illustration an example that is discussed in some detail is a technique for rapid in vitro single-cell elastography. The technique is based on atomic force acoustic microscopy (AFAM) but (1) requires only a few minutes of scan time, (2) can be used on live cells briefly removed from most of the nutrient fluid, (3) does negligible harm or damage to the cell, (4) provides semi-quantitative information on the distribution of modulus across the cell, and (5) yields data with 1-10 nm resolution. The technique is shown to enable rapid assessment of physical/biochemical signals on the cell modulus and contributes to current understanding of cell mechanics.

  7. Micro-radiography of biological samples with medical contrast agents

    NASA Astrophysics Data System (ADS)

    Dammer, J.; Weyda, F.; Benes, J.; Sopko, V.; Gelbic, I.

    2013-12-01

    Micro-radiography is an imaging technique that uses X-rays to study the internal structures of objects. This fast and easy imaging tool is based on differential X-ray attenuation by various tissues and structures within biological samples. The experimental setup described is based on the semiconductor pixel X-ray detector Medipix2 and X-ray micro-focus tube. Our micro-radiographic system has been recently used not only for the examination of internal structures of various arthropods and other biological objects but also for tracing some processes in selected model species (we used living larvae of mosquito Culex quinquefasciatus). Low concentrations of iodine, lanthanum or gold particles were used as a tracer (contrast agent). Such contrast agents increase the absorption of X-rays and allow a better visibility of internal structures of model organisms (especially the various cavities, pores, etc.). In addition, the movement of tracers in selected timing experiments demonstrates some physiological functions of digestive and excretory system.

  8. Environmental estrogens in an urban aquatic ecosystem: II. Biological effects.

    PubMed

    Schultz, Melissa M; Minarik, Thomas A; Martinovic-Weigelt, Dalma; Curran, Erin M; Bartell, Stephen E; Schoenfuss, Heiko L

    2013-11-01

    Urban aquatic ecosystems are often overlooked in toxicological studies even though they serve many ecosystem functions and sustain fish populations despite large-scale habitat alterations. However, urban fish populations are likely exposed to a broad range of stressors, including environmental estrogens (EEs) that may affect anatomy, physiology and reproduction of exposed fish. Although significant progress has been made in establishing ecological consequences of EE exposure, these studies have focused largely on hydrologically simple systems that lack the complexity of urban aquatic environments. Therefore, the objective of this study was to assess the occurrence and biological effects of EEs across a large urbanized aquatic ecosystem. A multi-pronged study design was employed relying on quantitative determination of select EEs by liquid chromatography tandem mass spectrometry and repeated biological monitoring of wild-caught and caged fish for indications of endocrine disruption. Over three years, EEs were measured in aqueous samples (n=42 samples) and biological effects assessed in >1200 male fish across the 2000km(2) aquatic ecosystems of the Greater Metropolitan Area of Chicago, IL. Our study demonstrated that in addition to water reclamation plant (WRP) effluents, non-WRP sources contribute significant EE loads to the aquatic ecosystem. While resident and caged male fish responded with the induction of the egg-yolk protein vitellogenin, an indicator of EE exposure, neither resident nor caged sunfish exhibited prevalent histopathological changes to their reproductive organs (i.e., intersex) that have been reported in other studies. Vitellogenin induction was greater in spring than the fall and was not correlated with body condition factor, gonadosomatic index or hepatosomatic index. Exposure effects were not correlated with sites downstream of treated effluent discharge further affirming the complexity of sources and effects of EEs in urban aquatic ecosystems.

  9. Monitoring prion protein expression in complex biological samples by SERS for diagnostic applications

    NASA Astrophysics Data System (ADS)

    Manno, D.; Filippo, E.; Fiore, R.; Serra, A.; Urso, E.; Rizzello, A.; Maffia, M.

    2010-04-01

    Surface-enhanced Raman spectroscopy (SERS) allows a new insight into the analysis of cell physiology. In this work, the difficulty of producing suitable substrates that, besides permitting the amplification of the Raman signal, do not interact with the biological material causing alteration, has been overcome by a combined method of hydrothermal green synthesis and thermal annealing. The SERS analysis of the cell membrane has been performed with special attention to the cellular prion protein PrPC. In addition, SERS has also been used to reveal the prion protein-Cu(II) interaction in four different cell models (B104, SH-SY5Y, GN11, HeLa), expressing PrPC at different levels. A significant implication of the current work consists of the intriguing possibility of revealing and quantifying prion protein expression in complex biological samples by a cheap SERS-based method, replacing the expensive and time-consuming immuno-assay systems commonly employed.

  10. Integral field spectroscopy of a sample of nearby galaxies. II. Properties of the H ii regions

    NASA Astrophysics Data System (ADS)

    Sánchez, S. F.; Rosales-Ortega, F. F.; Marino, R. A.; Iglesias-Páramo, J.; Vílchez, J. M.; Kennicutt, R. C.; Díaz, A. I.; Mast, D.; Monreal-Ibero, A.; García-Benito, R.; Bland-Hawthorn, J.; Pérez, E.; González Delgado, R.; Husemann, B.; López-Sánchez, Á. R.; Cid Fernandes, R.; Kehrig, C.; Walcher, C. J.; Gil de Paz, A.; Ellis, S.

    2012-10-01

    We analyse the spectroscopic properties of thousands of H ii regions identified in 38 face-on spiral galaxies. All galaxies were observed out to 2.4 effective radii using integral field spectroscopy (IFS) over the wavelength range ~3700 to ~6900 Å. The near uniform sample has been assembled from the PPAK IFS Nearby Galaxy (PINGS) survey and a sample described in Paper I. We develop a new automatic procedure to detect H ii regions, based on the contrast of the Hα intensity maps extracted from the datacubes. Once detected, the algorithm provides us with the integrated spectra of each individual segmented region. In total, we derive good quality spectroscopic information for ~2600 independent H ii regions/complexes. This is by far the largest H ii region survey of its kind. Our selection criteria and the use of 3D spectroscopy guarantee that we cover the regions in an unbiased way. A well-tested automatic decoupling procedure has been applied to remove the underlying stellar population, deriving the main properties (intensity, dispersion and velocity) of the strongest emission lines in the considered wavelength range (covering from [O ii] λ3727 to [S ii] λ6731). A final catalogue of the spectroscopic properties of H ii regions has been created for each galaxy, which includes information on morphology, spiral structure, gaskinematics, and surface brightness of the underlying stellar population. In the current study, we focus on the understanding of the average properties of the H ii regions and their radial distributions. We find a significant change in the ionisation characteristics of H ii regions within r < 0.25 re due to contamination from sources with different ionising characteristics, as we discuss. We find that the gas-phase oxygen abundance and the Hα equivalent width present a negative and positive gradient, respectively. The distribution of slopes is statistically compatible with a random Gaussian distribution around the mean value, if the radial

  11. Thin-layer chromatography analysis of fructooligosaccharides in biological samples.

    PubMed

    Reiffová, Katarína; Nemcová, Radomíra

    2006-03-31

    This study presents the application of a rapid, simple and inexpensive thin-layer chromatography (TLC) for the analysis of fructooligosaccharides (FOSs) as feed additives (prebiotics) in complicated biological samples with minimal pre-treatment. Prebiotics have been monitored in different parts of the intestinal tract (jejunum, ileum and colon) of monogastric animals to which commercially available dietetic products containing fructooligosaccharides Raftifeed IPX, Raftilose and polysaccharide maltodextrin have been added into the feed. Thereby it contributes to a clarification of fructooligosaccharides and polysaccharides transformation in the digestive system. Chromatographic separation has been studied on different chromatographic systems (stationary and mobile phases). Optimal separation of fructooligosaccharides in dietetic products as well as in the samples from intestinal tract of monogastric animals has been achieved on glass-backed precoated silica gel layers impregnated with sodium acetate. The layers were developed with butanol-ethanol-water (5:3:2, v/v) in a vertical trough glass chamber with mobile phase vapour saturation. The visualisation of FOSs on chromatograms was performed with mixture of diphenylamine-aniline-phosphoric acid in acetone as primary detection reagent. Coloured spots of FOSs (blue-pink spots) on chromatograms have also been detected by reflectance densitometry at wavelength lambda=370nm. Simultaneously, the concentration of acetic acid, which is one of FOSs fermentation product, was monitored in the intestinal contents from jejunum, ileum and colon by capillary isotachophoresis.

  12. EPR Methods for Biological Cu(II): L-Band CW and NARS

    PubMed Central

    Bennett, Brian; Kowalski, Jason

    2016-01-01

    Copper has many roles in biology that involve the change of coordination sphere and/or oxidation state of the copper ion. Consequently, the study of copper in heterogeneous environments is an important area in biophysics. EPR is a primary technique for the investigation of paramagnetic copper, which is usually the isolated Cu(II) ion, but sometimes as Cu(II) in different oxidation states of multi-transition ion clusters. The gross geometry of the coordination environment of Cu(II) can often be determined from a simple inspection of the EPR spectrum, recorded in the traditional X-band frequency range (9 – 10 GHz). Identification and quantitation of the coordinating ligand atoms, however, is not so straightforward. In particular, analysis of the superhyperfine structure on the EPR spectrum, to determine the number of coordinated nitrogen atoms, is fraught with difficulty at X-band, despite the observation that the overwhelming number of EPR studies of Cu(II) in the literature have been carried out at X-band. Greater reliability has been demonstrated at S-band (3 – 4 GHz), using the low-field parallel (gz) features. However, analysis relies on clear identification of the outermost superhyperfine line, which has the lowest intensity of all the spectral features. Computer simulations have subsequently indicated that the much more intense perpendicular region of the spectrum can be reliably interpreted at L-band (2 GHz). The present work describes the development of L-band EPR of Cu(II) into a routine method, that is applicable to biological samples. PMID:26478491

  13. EPR Methods for Biological Cu(II): L-Band CW and NARS.

    PubMed

    Bennett, Brian; Kowalski, Jason M

    2015-01-01

    Copper has many roles in biology that involve the change of coordination sphere and/or oxidation state of the copper ion. Consequently, the study of copper in heterogeneous environments is an important area in biophysics. EPR is a primary technique for the investigation of paramagnetic copper, which is usually the isolated Cu(II) ion, but sometimes as Cu(II) in different oxidation states of multitransition ion clusters. The gross geometry of the coordination environment of Cu(II) can often be determined from a simple inspection of the EPR spectrum, recorded in the traditional X-band frequency range (9-10 GHz). Identification and quantitation of the coordinating ligand atoms, however, is not so straightforward. In particular, analysis of the superhyperfine structure on the EPR spectrum, to determine the number of coordinated nitrogen atoms, is fraught with difficulty at X-band, despite the observation that the overwhelming number of EPR studies of Cu(II) in the literature have been carried out at X-band. Greater reliability has been demonstrated at S-band (3-4 GHz), using the low-field parallel (gz) features. However, analysis relies on clear identification of the outermost superhyperfine line, which has the lowest intensity of all the spectral features. Computer simulations have subsequently indicated that the much more intense perpendicular region of the spectrum can be reliably interpreted at L-band (2 GHz). The present work describes the development of L-band EPR of Cu(II) into a routine method that is applicable to biological samples.

  14. Extractions of pyrroloquinoline quinone from crude biological samples.

    PubMed

    Suzuki, O; Kumazawa, T; Seno, H; Urakami, T; Matsumoto, T

    1990-01-01

    The best conditions for extractions of free pyrroloquinoline quinone (PQQ) from crude biological samples were investigated with various organic solvents and Sep-Pak C18 cartridges. PQQ was measured with use of its native fluorescence in aqueous solution. PQQ was well extracted into n-butanol under acid conditions, and addition of NaCl did not improve the solvent extraction. PQQ, which had been extracted into n-butanol, could be re-extracted into an aqueous phase by addition of either n-heptane or pyridine, or combination of them. PQQ, which had been adsorbed to Sep-Pak C18 cartridges, could be eluted with a mixture of pyridine and water with very excellent recovery. The recovery of 1 micrograms PQQ, which had been added to 1 g human liver, brain and 1 ml plasma and had undergone the n-butanol and the Sep-Pak extractions, was 50, 75 and 105%, respectively. From the blank fluorescence, endogenous levels of free PQQ in human liver, brain and plasma were found not greater than 0.41, 0.08 and 0.13 micrograms/g or ml, respectively, if present.

  15. A novel visible spectrophotometric method for the determination of ethamsylate in pharmaceutical preparations and biological samples.

    PubMed

    Zhang, Meiyun; Zhang, Yan; Li, Quanmin

    2010-03-01

    A highly sensitive visible spectrophotometric method has been developed to determine ethamsylate in this paper, which is based on using Cu(II) as spectroscopic probe reagent. The study indicates that in the presence of SCN(-) and KNO(3), Cu(II) is reduced to Cu(I) by ethamsylate at pH 5.0, and the in situ formed Cu(I) reacts with SCN(-) to form into the white emulsion CuSCN that could be stayed upon the surface of water. According to the amount of residual Cu(II), the amount of ethamsylate can be indirectly determined. Under the optimal conditions, Beer's law is applicable in the range of 0.2-9.0 microg/mL (7.60x10(-7)-3.42x10(-5)mol/L) for aqueous standard solution of ethamsylate with linear correlation coefficient of 0.9998. The detection limit and relative standard deviation are 0.12 microg/mL and 1.5%, respectively. And the molar absorption coefficient of the indirect determination of ethamsylate is 1.0x10(5)L/mol cm. The method is successfully applied to determine ethamsylate in pharmaceutical preparations and biological samples.

  16. Human Ecology: A Perspective for Biology Education. Monograph Series II.

    ERIC Educational Resources Information Center

    Bybee, Rodger W.

    This monograph provides a framework for biology teachers who are rethinking and redesigning their programs. The major focus is on the human ecology perspective in biology programs. The first chapter attempts to define and clarify human ecology through historical review. The second chapter provides support, based on a survey of citizens…

  17. Novel spectroscopic sensor for the hydroxyl radical scavenging activity measurement of biological samples.

    PubMed

    Bekdeşer, Burcu; Özyürek, Mustafa; Güçlü, Kubilay; Apak, Reşat

    2012-09-15

    A novel spectroscopic sensor was developed and validated for hydroxyl radical scavenging (HRS) activity estimation using terephthalate (TP) as probe. This sensor was designed by electrostatic immobilization of the chromogenic oxidizing agent of the CUPric Reducing Antioxidant Capacity (CUPRAC) method, Cu(II)-Neocuproine (Cu(II)-Nc) complex, on a Nafion cation-exchange membrane, and the spectrophotometric assay developed in aqueous-alcoholic solutions was integrated to the CUPRAC sensor. Hydroxyl radicals ((•)OH) generated from an equivalent mixture of Fe(II)+EDTA with hydrogen peroxide attacked both the probe and the (•)OH scavengers in 37 °C-incubated solutions for 1/2h. The HRS activity was measured using the decrease in CUPRAC absorbance at 450 nm - arising from the reduction of Cu(II)-Nc reagent to the Cu(I)-neocuproine chelate - of the hydroxylated probe (TP) undergoing radical attack in the presence of (•)OH scavengers. The HRS activity was evaluated as the second-order rate constants of biologically active compounds for (•)OH scavenging and also as the percentage scavenging of a measured compound or sample relative to a reference compound. Using this reaction, a kinetic approach was adopted to assess the HRS activity of amino acids, plasma- and thiol-antioxidants. This assay, applicable to small molecule antioxidants and tissue homogenates, proved to be efficient for serine and albumin for which the widely used TBARS (thiobarbituric acid-reactive substances) test is nonresponsive. Under optimal conditions, about half of the probe (TP) was converted into 2-hydroxyterephthalate (hTP), and this monohydroxylated derivative, being the only product of hydroxylation, was a more specific marker of (•)OH than the non-specific malondialdehyde end-product of the TBARS test. The sensor gave a linear response to scavenger concentration in the competition kinetic equation.

  18. 9 CFR 113.3 - Sampling of biological products.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    .... Each sample shall be marked for identification by the person making the selection after which they..., Modified Live Virus; (v) Sixteen samples of all other vaccines consisting of live microorganisms; (vi...-dose or 12 multiple-dose samples of all other vaccines consisting of killed microorganisms....

  19. 9 CFR 113.3 - Sampling of biological products.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    .... Each sample shall be marked for identification by the person making the selection after which they..., Modified Live Virus; (v) Sixteen samples of all other vaccines consisting of live microorganisms; (vi...-dose or 12 multiple-dose samples of all other vaccines consisting of killed microorganisms....

  20. 9 CFR 113.3 - Sampling of biological products.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    .... Each sample shall be marked for identification by the person making the selection after which they..., Modified Live Virus; (v) Sixteen samples of all other vaccines consisting of live microorganisms; (vi...-dose or 12 multiple-dose samples of all other vaccines consisting of killed microorganisms....

  1. 9 CFR 113.3 - Sampling of biological products.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    .... Each sample shall be marked for identification by the person making the selection after which they..., Modified Live Virus; (v) Sixteen samples of all other vaccines consisting of live microorganisms; (vi...-dose or 12 multiple-dose samples of all other vaccines consisting of killed microorganisms....

  2. Serum and tissue PIVKA-II expression reflect the biological malignant potential of small hepatocellular carcinoma.

    PubMed

    Tamano, Masaya; Sugaya, Hitoshi; Oguma, Motoo; Iijima, Makoto; Yoneda, Masashi; Murohisa, Toshimitsu; Kojima, Kazuo; Kuniyoshi, Toru; Majima, Yuichi; Hashimoto, Takashi; Terano, Akira

    2002-04-01

    A sensitive method for measuring the serum level of protein-induced by vitamin K absence or antagonist II (PIVKA-II) has become so widely available that it is now used for the clinical diagnosis of small hepatocellular carcinoma (HCC). It is known that serum PIVKA-II can be a prognostic indicator for HCC, but there have been no detailed investigations concerning the tissue expression of PIVKA-II. The present study assessed the relationship between serum or tissue PIVKA-II and the biological malignant potential of HCC. The subjects were 25 patients with histologically confirmed HCC, that were solitary and 3 cm or less in diameter. Tissue PIVKA-II was detected by immunostaining using MU-3 as the primary antibody. The biological malignant potential of the tumors was evaluated on the basis of the Ki-67 labeling index of HCC cells and the tumor arterial vascularity assesed by angiography and CO(2) enhanced ultrasonography. The recurrence-free period after treatment was also evaluated. Among the 25 patients, eight were positive for tissue PIVKA-II. Serum PIVKA-II levels were significantly higher in the tissue PIVKA-II-positive patients compared with the negative patients, but serum and tissue PIVKA-II expressions were not consistently parallel. Tumor cell proliferation was closely correlated with the tissue PIVKA-II expression, while the recurrence-free period was correlated with the serum PIVKA-II level. Tumor arterial vascularity showed a strong correlation with the expression of both serum and tissue PIVKA-II. In conclusion, serum and tissue PIVKA-II expression reflect the biological malignant potential of HCC and thus may be useful indicators for the prognosis of small HCC.

  3. Strontium: Part II. Chemistry, Biological Aspects and Applications.

    ERIC Educational Resources Information Center

    Britton, G. C.; Johnson, C. H.

    1987-01-01

    Reviews basic information on the Chemistry of strontium and its compounds. Explains biological aspects of strontium and its pharmaceutical applications. Highlights industrial application of strontium and its components. (ML)

  4. Invasion Ecology and School Biology--Part II.

    ERIC Educational Resources Information Center

    Wells, R. V.

    1981-01-01

    Suggests that invasion biology can supply subject matter for teaching evolution, genetics, ecological relationships, and conservation. Describes flowering and non-flowering plant invaders, vertebrates and invertebrates, and two ecological invasions on the southern coast of England. (JN)

  5. Molecular mechanisms of the biological activity of the anticancer drug elesclomol and its complexes with Cu(II), Ni(II) and Pt(II).

    PubMed

    Yadav, Arun A; Patel, Daywin; Wu, Xing; Hasinoff, Brian B

    2013-09-01

    The bis(thiohydrazide) amide elesclomol has extremely potent antiproliferative activity and is currently in clinical trials as an anticancer agent. Elesclomol strongly binds copper and may be exerting its cell growth inhibitory effects by generating copper-mediated oxidative stress. Nickel(II) and platinum(II) complexes of elesclomol were synthesized and characterized in order to investigate if these biologically redox inactive metal complexes could also inhibit cell growth. The nickel(II)-elesclomol and platinum(II) elesclomol complexes were 34- and 1040-fold less potent than the copper(II)-elesclomol complex towards human leukemia K562 cells. These results support the conclusion that a redox active metal is required for elesclomol to exert its cell growth inhibitory activity. Copper(II)-elesclomol was also shown to efficiently oxidize ascorbic acid at physiological ascorbic acid concentrations. Reoxidation of the copper(I) thus produced would lead to production of damaging reactive oxygen species. An X-ray crystallographic structure determination of copper(II)-elesclomol showed that it formed a 1:1 neutral complex with a distorted square planar structure. The kinetics and equilibria of the competition reaction of the strong copper(II) chelator TRIEN with copper(II)-elesclomol were studied spectrophotometrically under physiological conditions. These results showed elesclomol bound copper(II) with a conditional stability constant 24-fold larger than TRIEN. A log stability constant of 24.2 was thus indirectly determined for the copper(II)-elesclomol complex.

  6. Development of a new catalase activity assay for biological samples using optical CUPRAC sensor

    NASA Astrophysics Data System (ADS)

    Bekdeşer, Burcu; Özyürek, Mustafa; Güçlü, Kubilay; Alkan, Fulya Üstün; Apak, Reşat

    2014-11-01

    A novel catalase activity assay was developed for biological samples (liver and kidney tissue homogenates) using a rapid and low-cost optical sensor-based ‘cupric reducing antioxidant capacity' (CUPRAC) method. The reagent, copper(II)-neocuproine (Cu(II)-Nc) complex, was immobilized onto a cation-exchanger film of Nafion, and the absorbance changes associated with the formation of the highly-colored Cu(I)-Nc chelate as a result of reaction with hydrogen peroxide (H2O2) was measured at 450 nm. When catalase was absent, H2O2 produced the CUPRAC chromophore, whereas catalase, being an effective H2O2 scavenger, completely annihilated the CUPRAC signal due to H2O2. Thus, the CUPRAC absorbance due to H2O2 oxidation concomitant with Cu(I)-Nc formation decreased proportionally with catalase. The developed sensor gave a linear response over a wide concentration range of H2O2 (0.68-78.6 μM). This optical sensor-based method applicable to tissue homogenates proved to be efficient for low hydrogen peroxide concentrations (physiological and nontoxic levels) to which the widely used UV method is not accurately responsive. Thus, conventional problems of the UV method arising from relatively low sensitivity and selectivity, and absorbance disturbance due to gaseous oxygen evolution were overcome. The catalase findings of the proposed method for tissue homogenates were statistically alike with those of HPLC.

  7. Development of a new catalase activity assay for biological samples using optical CUPRAC sensor.

    PubMed

    Bekdeşer, Burcu; Özyürek, Mustafa; Güçlü, Kubilay; Alkan, Fulya Üstün; Apak, Reşat

    2014-11-11

    A novel catalase activity assay was developed for biological samples (liver and kidney tissue homogenates) using a rapid and low-cost optical sensor-based 'cupric reducing antioxidant capacity' (CUPRAC) method. The reagent, copper(II)-neocuproine (Cu(II)-Nc) complex, was immobilized onto a cation-exchanger film of Nafion, and the absorbance changes associated with the formation of the highly-colored Cu(I)-Nc chelate as a result of reaction with hydrogen peroxide (H2O2) was measured at 450 nm. When catalase was absent, H2O2 produced the CUPRAC chromophore, whereas catalase, being an effective H2O2 scavenger, completely annihilated the CUPRAC signal due to H2O2. Thus, the CUPRAC absorbance due to H2O2 oxidation concomitant with Cu(I)-Nc formation decreased proportionally with catalase. The developed sensor gave a linear response over a wide concentration range of H2O2 (0.68-78.6 μM). This optical sensor-based method applicable to tissue homogenates proved to be efficient for low hydrogen peroxide concentrations (physiological and nontoxic levels) to which the widely used UV method is not accurately responsive. Thus, conventional problems of the UV method arising from relatively low sensitivity and selectivity, and absorbance disturbance due to gaseous oxygen evolution were overcome. The catalase findings of the proposed method for tissue homogenates were statistically alike with those of HPLC.

  8. A data-independent acquisition workflow for qualitative screening of new psychoactive substances in biological samples.

    PubMed

    Kinyua, Juliet; Negreira, Noelia; Ibáñez, María; Bijlsma, Lubertus; Hernández, Félix; Covaci, Adrian; van Nuijs, Alexander L N

    2015-11-01

    Identification of new psychoactive substances (NPS) is challenging. Developing targeted methods for their analysis can be difficult and costly due to their impermanence on the drug scene. Accurate-mass mass spectrometry (AMMS) using a quadrupole time-of-flight (QTOF) analyzer can be useful for wide-scope screening since it provides sensitive, full-spectrum MS data. Our article presents a qualitative screening workflow based on data-independent acquisition mode (all-ions MS/MS) on liquid chromatography (LC) coupled to QTOFMS for the detection and identification of NPS in biological matrices. The workflow combines and structures fundamentals of target and suspect screening data processing techniques in a structured algorithm. This allows the detection and tentative identification of NPS and their metabolites. We have applied the workflow to two actual case studies involving drug intoxications where we detected and confirmed the parent compounds ketamine, 25B-NBOMe, 25C-NBOMe, and several predicted phase I and II metabolites not previously reported in urine and serum samples. The screening workflow demonstrates the added value for the detection and identification of NPS in biological matrices.

  9. A data-independent acquisition workflow for qualitative screening of new psychoactive substances in biological samples.

    PubMed

    Kinyua, Juliet; Negreira, Noelia; Ibáñez, María; Bijlsma, Lubertus; Hernández, Félix; Covaci, Adrian; van Nuijs, Alexander L N

    2015-11-01

    Identification of new psychoactive substances (NPS) is challenging. Developing targeted methods for their analysis can be difficult and costly due to their impermanence on the drug scene. Accurate-mass mass spectrometry (AMMS) using a quadrupole time-of-flight (QTOF) analyzer can be useful for wide-scope screening since it provides sensitive, full-spectrum MS data. Our article presents a qualitative screening workflow based on data-independent acquisition mode (all-ions MS/MS) on liquid chromatography (LC) coupled to QTOFMS for the detection and identification of NPS in biological matrices. The workflow combines and structures fundamentals of target and suspect screening data processing techniques in a structured algorithm. This allows the detection and tentative identification of NPS and their metabolites. We have applied the workflow to two actual case studies involving drug intoxications where we detected and confirmed the parent compounds ketamine, 25B-NBOMe, 25C-NBOMe, and several predicted phase I and II metabolites not previously reported in urine and serum samples. The screening workflow demonstrates the added value for the detection and identification of NPS in biological matrices. PMID:26396082

  10. Topical Conference on Oportunities in Biology for Physicists II

    SciTech Connect

    Franz, Judy R.

    2004-02-01

    In 2002, the American Physical Society (APS) organized and held the first topical conference in Boston, MA, as a way of informing physicists, particularly those just entering the field, of opportunities emerging at the interface of physics and biology. Because of the tremendous success of the first conference, it was decided to organize a second conference, similar in nature and focus, but with different presentation topic areas. Again the intended audience would be graduate students and postdocs considering applying methods of physics to biological research, and those who advise others on such opportunities.

  11. Elemental mapping of biological samples using a scanning proton microprobe

    NASA Astrophysics Data System (ADS)

    Watt, F.; Grime, G. W.

    1988-03-01

    Elemental mapping using a scanning proton microprobe (SPM) can be a powerful technique for probing trace elements in biology, allowing complex interfaces to be studied in detail, identifying contamination and artefacts present in the specimen, and in certain circumstances obtaining indirect chemical information. Examples used to illustrate the advantages of the technique include the elemental mapping of growing pollen tubes, honey bee brain section, a mouse macrophage cell, human liver section exhibiting primary biliary cirrhosis, and the attack by a mildew fungus on a pea leaf.

  12. River Pollution: Part II. Biological Methods for Assessing Water Quality.

    ERIC Educational Resources Information Center

    Openshaw, Peter

    1984-01-01

    Discusses methods used in the biological assessment of river quality and such indicators of clean and polluted waters as the Trent Biotic Index, Chandler Score System, and species diversity indexes. Includes a summary of a river classification scheme based on quality criteria related to water use. (JN)

  13. Alteration of biological samples in speciation analysis of metalloproteins.

    PubMed

    Wolf, Christian; Wenda, Nadine; Richter, Andrea; Kyriakopoulos, Antonios

    2007-10-01

    For investigations of metalloproteins by speciation analysis, the integrity of the protein-metal complexes before and during separation is crucial. Knowledge about potential alterations of the samples is thus essential to avoid misinterpretations of the analytical results. Chromatographic element profiles of different cytosolic samples from animal tissues were measured repeatedly to estimate the sample stability. The dependence of the signals on the dwell time of the sample in an autosampling device at 4 degrees C for a period of 10 h was observed. Alterations in the element content of different metal-containing fractions were quantified by means of recovery values. Some metalloprotein fractions (e.g. approximately 27-kDa arsenic, approximately 27-kDa iron and different zinc fractions) were stable or only minor alterations were observed and for their investigation an autosampling device is therefore suitable. However, most of the other metalloprotein fractions, especially nickel-containing proteins, showed major alterations: these samples should therefore be analysed immediately after preparation or directly after thawing.

  14. Determinations of actinides in biological and environmental samples.

    PubMed

    Singh, N P; Wrenn, M E

    1988-03-01

    This paper summarises the radiochemical procedures utilised in our laboratory to determine U, Th and Pu in different sample matrices, including soft tissues, bones, urine, faeces, soil, water, air-filters, lichen, and building materials such as granite, phosphate and concrete. Sample preparation, depending upon the matrix of the sample, includes either dry ashing and/or wet ashing with a mixture of HNO3 and H2SO4 or HNO3 alone with occasional additions of a few drops of HNO3 and H2O2. Uranium, Th and Pu are either co-precipitated with Fe carrier as hydroxides or with Ca as oxalates. Solvent extractions are performed from 2M HNO3, 4M HNO3 or 10M HCl depending upon the actinide or combination of actinides to be determined. The techniques have been very successful for most samples, with radiochemical recoveries exceeding 70%. However, radiochemical recoveries of Th from soil samples have been very poor (10-30%). Attempts are being made to improve these recoveries.

  15. Determination of platinum, palladium, and lead in biological samples by atomic absorption spectrophotometry.

    PubMed Central

    Tillery, J B; Johnson, D E

    1975-01-01

    A flameless atomic absorption method for the coextraction of platinum and palladium from biological and environmental samples by high molecular weight amine (HMWA) is given. Also, methods for lead determination in biological samples by use of extraction flameless analysis and direct aspiration-flame analysis are reported. A study of lead contamination of Vacutainer tubes is given. PMID:1227857

  16. Energy loss and straggling of MeV ions through biological samples

    SciTech Connect

    Ma Lei; Wang Yugang; Xue Jianming; Chen Qizhong; Zhang Weiming; Zhang Yanwen

    2007-10-15

    Energy loss and energy straggling of energetic ions through natural dehydrated biological samples were investigated using transmission technique. Biological samples (onion membrane, egg coat, and tomato coat) with different mass thickness were studied, together with Mylar for comparison. The energy loss and energy straggling of MeV H and He ions after penetrating the biological and Mylar samples were measured. The experimental results show that the average energy losses of MeV ions through the biological samples are consistent with SRIM predictions; however, large deviation in energy straggling is observed between the measured results and the SRIM predictions. Taking into account inhomogeneity in mass density and structure of the biological sample, an energy straggling formula is suggested, and the experimental energy straggling values are well predicted by the proposed formula.

  17. Energy loss and straggling of MeV ions through biological samples

    SciTech Connect

    Ma, Lie; Wang, Yugang; Xue, Jianming; Chen, Qizhong; Zhang, Weiming; Zhang, Yanwen

    2007-10-15

    Energy loss and energy straggling of energetic ions through natural dehydrated biological samples were investigated using transmission technique. Biological samples (onion membrane, egg coat and tomato coat) with different mass thickness were studied, together with mylar for comparison, in this work. The energy loss and energy straggling of MeV H and He ions after penetrating from the biological and mylar samples were measured. The experimental results show that the average energy losses of MeV ions through the biological samples are consistent with SRIM predictions, however, large deviation in energy straggling is observed between the measured result and the SRIM predictions. Taking into account inhomogeneity in mass density and structure of the biological sample, an energy straggling formula is suggested, and the experimental energy straggling values are well predicated by the proposed formula.

  18. Study of the spectral features of different biological samples

    NASA Astrophysics Data System (ADS)

    Atif, M.

    2015-03-01

    In the present study we have observed and analyzed the fluorescence changes in the fluorescence spectra of four different samples like brilliant sulphaflanine, quinine bisulphate, coumarine 120 and porcine cornea and sclera including the changes in fluorescence spectrum of cornea are also observed after CO2 laser exposure. The preliminary study clearly explains the proof of concept only.

  19. Sampling of vehicle emissions for chemical analysis and biological testing.

    PubMed Central

    Schuetzle, D

    1983-01-01

    Representative dilution tube sampling techniques for particulate and gas phase vehicle emissions are described using Teflon filter media and XAD-2 resin. More than 90% of the total gas (C8-C18) and particulate direct acting Ames assay mutagenicity (TA 98) was found in the particulate phase. The gas and particulate phase material was fractionated by HPLC into nonpolar, moderately polar and highly polar chemical fractions. The moderately polar chemical fraction of the particulates contained more than 50% of the direct acting Ames assay mutagenicity for the total extract. The concentration of oxygenated polynuclear aromatic hydrocarbons (oxy-PAH) and nitrated PAH (nitro-PAH) identified in the moderately polar particulate fractions are given. Nitro-PAH account for most of the direct-acting (TA 98) Ames assay mutagenicity in these moderately polar fractions. Reactions and kinetic expressions for chemical conversion of PAH are presented. Chemical conversion of PAH to nitro-PAH during dilution tube sampling of particulates on Teflon filters and gases on XAD-2 resin is a minor problem (representing 10-20%, on the average, of the 1-nitropyrene found in extracts) at short (46 min) sampling times, at low sampling temperatures (42 degrees C), and in diluted exhaust containing 3 ppm NO2. Particulate emissions collected from dilution tubes on filter media appear to be representative of what is emitted in the environment as based upon a comparison of highway and laboratory studies. PMID:6186484

  20. Copper(II) and nickel(II) complexes of benzyloxybenzaldehyde-4-phenyl-3-thiosemicarbazone: Synthesis, characterization and biological activity

    NASA Astrophysics Data System (ADS)

    Prathima, B.; Subba Rao, Y.; Adinarayana Reddy, S.; Reddy, Y. P.; Varada Reddy, A.

    2010-09-01

    Benzyloxybenzaldehyde-4-phenyl-3-thiosemicarbazone ligand (L) has been synthesized from benzyloxybenzaldehyde and 4-phenyl-3-thiosemicarbazide. Complexes of this ligand with chlorides of Cu(II) and Ni(II) have been prepared. The structure of the ligand (L) is proposed based on elemental analysis, IR and 1H NMR spectra. Its complexes with Cu(II) and Ni(II) ions are characterized from the studies of electronic as well as EPR spectra. On the basis of electronic and EPR studies, rhombically distorted octahedral structure has been proposed for Cu(II) complex while the Ni(II) complex has been found to acquire an octahedral structure. The ligand and their metal complexes have been tested in vitro for their biological effects. Their antibacterial activities against Gram-negative bacteria ( Escherichia coli and Klebsiella pneumoniae) and Gram-positive bacteria ( Staphylococcus aureus and Bacillus subtilis) have been investigated. The prepared metal complexes exhibit higher antibacterial activities than the parent ligand. The in vitro antioxidant activity of free ligand and its metal(II) complexes have also been investigated and the results however reveal that the ligand exhibits greater antioxidant activity than its complexes.

  1. Investigating Sexual Harassment Complaints--Part II: A Sample Procedure.

    ERIC Educational Resources Information Center

    Uhler, Scott F.; Allison, Rinda Y.

    1997-01-01

    Provides an example of procedures to be followed when investigating a sexual harassment complaint in libraries. Highlights include preparation, including reviewing personnel files; interviewing the complainant, including sample questions; interviewing the alleged harasser; gathering information from other sources, including third-party witnesses;…

  2. Family Violence: A Curriculum Sample. Women's Issues Series, Vol. II.

    ERIC Educational Resources Information Center

    Refugee Women's Alliance, Seattle, WA.

    The materials in this curriculum sample are written as an English-as-a-Second-Language (ESL) lesson for immigrants and refugees, designed to begin discussion of family violence. An introductory section outlines issues related to discussion of family violence in the classroom setting, including the importance of opening lines of communication and…

  3. Application of carrier element free coprecipitation (CEFC) method for determination of Co(II), Cu(II) and Ni(II) ions in food and water samples.

    PubMed

    Serencam, Huseyin; Duran, Celal; Ozdes, Duygu; Bektas, Hakan

    2013-01-01

    A simple and highly sensitive separation and preconcentration procedure, which has minimal impact on the environment, has been developed. The procedure is based on the carrier element free coprecipitation (CEFC) of Co(II), Cu(II), and Ni(II) ions by using 2-{4-[2-(1H-indol-3-yl)ethyl]-3-(4-methylbenzyl)-5-oxo-4,5-dihydro- 1H-1,2,4-triazol-l-yl}-N'-(pyridin-2-yl methylidene)acetohydrazide (IMOTPA), as an organic coprecipitant. The levels of analyte ions were determined by flame atomic absorption spectrometry (FAAS). The detection limits for Co(II), Cu(II) and Ni(II) ions were found to be 0.40, 0.16 and 0.17 microg L(-1), respectively, and the relative standard deviations for the analyte ions were lower than 3.0%. Spike tests and certified reference material analyses were performed to validate the method. The method was successfully applied for the determination of Co(II), Cu(II) and Ni(II) ions levels in sea and stream water as liquid samples and red pepper, black pepper, and peppermint as solid samples. PMID:23878931

  4. Reaction mechanism of Ru(II) piano-stool complexes: umbrella sampling QM/MM MD study.

    PubMed

    Futera, Zdeněk; Burda, Jaroslav V

    2014-07-15

    Biologically relevant interactions of piano-stool ruthenium(II) complexes with ds-DNA are studied in this article by hybrid quantum mechanics-molecular mechanics (QM/MM) computational technique. The whole reaction mechanism is divided into three phases: (i) hydration of the [Ru(II) (η(6) -benzene)(en)Cl](+) complex, (ii) monoadduct formation between the resulting aqua-Ru(II) complex and N7 position of one of the guanines in the ds-DNA oligomer, and (iii) formation of the intrastrand Ru(II) bridge (cross-link) between two adjacent guanines. Free energy profiles of all the reactions are explored by QM/MM MD umbrella sampling approach where the Ru(II) complex and two guanines represent a quantum core, which is described by density functional theory methods. The combined QM/MM scheme is realized by our own software, which was developed to couple several quantum chemical programs (in this study Gaussian 09) and Amber 11 package. Calculated free energy barriers of the both ruthenium hydration and Ru(II)-N7(G) DNA binding process are in good agreement with experimentally measured rate constants. Then, this method was used to study the possibility of cross-link formation. One feasible pathway leading to Ru(II) guanine-guanine cross-link with synchronous releasing of the benzene ligand is predicted. The cross-linking is an exergonic process with the energy barrier lower than for the monoadduct reaction of Ru(II) complex with ds-DNA.

  5. Reaction mechanism of Ru(II) piano-stool complexes: umbrella sampling QM/MM MD study.

    PubMed

    Futera, Zdeněk; Burda, Jaroslav V

    2014-07-15

    Biologically relevant interactions of piano-stool ruthenium(II) complexes with ds-DNA are studied in this article by hybrid quantum mechanics-molecular mechanics (QM/MM) computational technique. The whole reaction mechanism is divided into three phases: (i) hydration of the [Ru(II) (η(6) -benzene)(en)Cl](+) complex, (ii) monoadduct formation between the resulting aqua-Ru(II) complex and N7 position of one of the guanines in the ds-DNA oligomer, and (iii) formation of the intrastrand Ru(II) bridge (cross-link) between two adjacent guanines. Free energy profiles of all the reactions are explored by QM/MM MD umbrella sampling approach where the Ru(II) complex and two guanines represent a quantum core, which is described by density functional theory methods. The combined QM/MM scheme is realized by our own software, which was developed to couple several quantum chemical programs (in this study Gaussian 09) and Amber 11 package. Calculated free energy barriers of the both ruthenium hydration and Ru(II)-N7(G) DNA binding process are in good agreement with experimentally measured rate constants. Then, this method was used to study the possibility of cross-link formation. One feasible pathway leading to Ru(II) guanine-guanine cross-link with synchronous releasing of the benzene ligand is predicted. The cross-linking is an exergonic process with the energy barrier lower than for the monoadduct reaction of Ru(II) complex with ds-DNA. PMID:24865949

  6. Soft Robotic Grippers for Biological Sampling on Deep Reefs

    PubMed Central

    Galloway, Kevin C.; Becker, Kaitlyn P.; Phillips, Brennan; Kirby, Jordan; Licht, Stephen; Tchernov, Dan; Gruber, David F.

    2016-01-01

    Abstract This article presents the development of an underwater gripper that utilizes soft robotics technology to delicately manipulate and sample fragile species on the deep reef. Existing solutions for deep sea robotic manipulation have historically been driven by the oil industry, resulting in destructive interactions with undersea life. Soft material robotics relies on compliant materials that are inherently impedance matched to natural environments and to soft or fragile organisms. We demonstrate design principles for soft robot end effectors, bench-top characterization of their grasping performance, and conclude by describing in situ testing at mesophotic depths. The result is the first use of soft robotics in the deep sea for the nondestructive sampling of benthic fauna. PMID:27625917

  7. Soft Robotic Grippers for Biological Sampling on Deep Reefs

    PubMed Central

    Galloway, Kevin C.; Becker, Kaitlyn P.; Phillips, Brennan; Kirby, Jordan; Licht, Stephen; Tchernov, Dan; Gruber, David F.

    2016-01-01

    Abstract This article presents the development of an underwater gripper that utilizes soft robotics technology to delicately manipulate and sample fragile species on the deep reef. Existing solutions for deep sea robotic manipulation have historically been driven by the oil industry, resulting in destructive interactions with undersea life. Soft material robotics relies on compliant materials that are inherently impedance matched to natural environments and to soft or fragile organisms. We demonstrate design principles for soft robot end effectors, bench-top characterization of their grasping performance, and conclude by describing in situ testing at mesophotic depths. The result is the first use of soft robotics in the deep sea for the nondestructive sampling of benthic fauna.

  8. Use of STM for analysis of surfaces of biological samples

    NASA Astrophysics Data System (ADS)

    Permjakov, N. K.; Ananyan, M. A.; Luskinovich, P. N.; Sorokovoi, V. I.; Saveliev, S. V.

    1999-04-01

    Scanning tunnelling microscopy (STM) was used to image the cell surfaces of the olfactory organ of the shark Carcharhinus longimanus and ectoderm of the frog Xenopus laevis blastulae of 1024 stages, as well as human low-density lipoproteins surface. The samples from two of these objects were prepared by using traditional techniques for scanning electron microscopy (SEM). The lipoprotein samples were prepared by drying in the air. A comparison of the STM images with the earlier obtained SEM images indicates that there are some earlier unknown details of the surface structures of receptor microvilli and support cell membranes of the olfactory organ of the shark. There was found a fold of membrane on the surface of the ectodermal frog embryo cells, which covered yolk granules. STM images of the lipoprotein surface were obtained without increasing conductivity treatment.

  9. Experiment kits for processing biological samples inflight on SLS-2

    NASA Technical Reports Server (NTRS)

    Savage, P. D.; Hinds, W. E.; Jaquez, R.; Evans, J.; Dubrovin, L.

    1995-01-01

    This paper describes development of an innovative, modular approach to packaging the instruments used to obtain and preserve the inflight rodent tissue and blood samples associated with hematology experiments on the Spacelab Life Sciences-2 (SLS-2) mission. The design approach organized the multitude of instruments into twelve 5- x 6- x l-in. kits which were each used for a particular experiment. Each kit contained the syringes, vials, microscope slides, etc., necessary for processing and storing blood and tissue samples for one rat on a particular day. A total of 1245 components, packaged into 128 kits and stowed in 17 Zero(registered trademark) boxes, were required. Crewmembers found the design easy to use and laid out in a logical, simple configuration which minimized chances for error during the complex procedures in flight. This paper also summarizes inflight performance of the kits on SLS-2.

  10. Elemental distribution and sample integrity comparison of freeze-dried and frozen-hydrated biological tissue samples with nuclear microprobe

    NASA Astrophysics Data System (ADS)

    Vavpetič, P.; Vogel-Mikuš, K.; Jeromel, L.; Ogrinc Potočnik, N.; Pongrac, P.; Drobne, D.; Pipan Tkalec, Ž.; Novak, S.; Kos, M.; Koren, Š.; Regvar, M.; Pelicon, P.

    2015-04-01

    The analysis of biological samples in frozen-hydrated state with micro-PIXE technique at Jožef Stefan Institute (JSI) nuclear microprobe has matured to a point that enables us to measure and examine frozen tissue samples routinely as a standard research method. Cryotome-cut slice of frozen-hydrated biological sample is mounted between two thin foils and positioned on the sample holder. The temperature of the cold stage in the measuring chamber is kept below 130 K throughout the insertion of the samples and the proton beam exposure. Matrix composition of frozen-hydrated tissue is consisted mostly of ice. Sample deterioration during proton beam exposure is monitored during the experiment, as both Elastic Backscattering Spectrometry (EBS) and Scanning Transmission Ion Microscopy (STIM) in on-off axis geometry are recorded together with the events in two PIXE detectors and backscattered ions from the chopper in a single list-mode file. The aim of this experiment was to determine differences and similarities between two kinds of biological sample preparation techniques for micro-PIXE analysis, namely freeze-drying and frozen-hydrated sample preparation in order to evaluate the improvements in the elemental localisation of the latter technique if any. In the presented work, a standard micro-PIXE configuration for tissue mapping at JSI was used with five detection systems operating in parallel, with proton beam cross section of 1.0 × 1.0 μm2 and a beam current of 100 pA. The comparison of the resulting elemental distributions measured at the biological tissue prepared in the frozen-hydrated and in the freeze-dried state revealed differences in elemental distribution of particular elements at the cellular level due to the morphology alteration in particular tissue compartments induced either by water removal in the lyophilisation process or by unsatisfactory preparation of samples for cutting and mounting during the shock-freezing phase of sample preparation.

  11. Determination of Alkali Ions in Biological and Environmental Samples.

    PubMed

    Hauser, Peter C

    2016-01-01

    An overview of the common methods for the determination of the alkali metals is given. These are drawn from all of the three principle branches of quantitative analysis and consist mainly of optical atomic spectrometric methods, ion-selective electrodes, and the separation methods of ion-chromatography and capillary electrophoresis. Their main characteristics and performance parameters are discussed. Important specific applications are also examined, namely clinical analysis, single cell analysis, the analysis of soil samples and hydroponic nutrient solutions, as well as the detection of the radioactive (137)Cs isotope. PMID:26860298

  12. Determination of Alkali Ions in Biological and Environmental Samples.

    PubMed

    Hauser, Peter C

    2016-01-01

    An overview of the common methods for the determination of the alkali metals is given. These are drawn from all of the three principle branches of quantitative analysis and consist mainly of optical atomic spectrometric methods, ion-selective electrodes, and the separation methods of ion-chromatography and capillary electrophoresis. Their main characteristics and performance parameters are discussed. Important specific applications are also examined, namely clinical analysis, single cell analysis, the analysis of soil samples and hydroponic nutrient solutions, as well as the detection of the radioactive (137)Cs isotope.

  13. Cloud-point extraction, preconcentration and spectrophotometric determination of trace quantities of copper in food, water and biological samples.

    PubMed

    Gouda, Ayman A; Amin, Alaa S

    2014-01-01

    A new, simple and sensitive cloud point extraction procedure was presented for the preconcentration and determination of copper(II) ion in food, water and biological samples. The analyte was complexed with a new synthesized reagent, 2-amino-4-(m-tolylazo)pyridine-3-ol (ATAP) as a new complexing agent and Triton X-114 as the surfactant. After centrifugation, dilution of the surfactant-rich phase with 0.4 mL of ethanol acidified with 1.0M HNO3 was performed after phase separation, and the copper contents were measured by spectrophotometry at λmax 608 nm. The influence of analytical parameters including concentration of complexing agent, Triton X-114, pH, equilibration temperature and time, centrifuge rate and time were optimized. The analytical characteristics of the method (e.g. linear range, molar absorptivity, Sandell sensitivity, optimum Ringbom concentration ranges limits of detection and quantification, preconcentration factor, and improvement factors) were obtained. Linearity was obeyed in the range of 4.0-115 ng mL(-1) of Cu(II) ion. The detection and quantification limits of the method were 1.20 and 3.94 ng mL(-1) of Cu(II) ion, respectively. The interference effect of some anions and cations was also tested. The method was applied for determination of copper in food, water and biological samples.

  14. Physicochemical and biological properties of oxovanadium(IV), cobalt(II) and nickel(II) complexes with oxydiacetate anions.

    PubMed

    Wyrzykowski, Dariusz; Kloska, Anna; Pranczk, Joanna; Szczepańska, Aneta; Tesmar, Aleksandra; Jacewicz, Dagmara; Pilarski, Bogusław; Chmurzyński, Lech

    2015-03-01

    The potentiometric and conductometric titration methods have been used to characterize the stability of series of VO(IV)-, Co(II)- and Ni(II)-oxydiacetato complexes in DMSO-water solutions containing 0-50 % (v/v) DMSO. The influence of DMSO as a co-solvent on the stability of the complexes as well as the oxydiacetic acid was evaluated. Furthermore, the reactivity of the complexes towards superoxide free radicals was assessed by employing the nitro blue tetrazolium (NBT) assay. The biological properties of the complexes were investigated in relation to their cytoprotective activity against the oxidative damage generated exogenously by using hydrogen peroxide in the Human Dermal Fibroblasts adult (HDFa) cell line as well as to their antimicrobial activity against the bacteria (Bacillus subtilis, Escherichia coli, Enterococcus faecalis, Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus epidermidis). The relationship between physicochemical and biological properties of the complexes was discussed. PMID:25488702

  15. [Dementias: present situation and future perspectives (II). Biological markers].

    PubMed

    Espert, R; Bertolín, J M; Navarro, J F; González, A

    1995-01-01

    In the previous paper, the first one in our trilogy about dementias, we introduce the concept and evaluate the diagnostic methods and the data provided by epidemiological investigation. In this paper we review the different biological diagnostic markers, based, in the first place, on the studies of neuroimage (computerized axial tomography, magnetic resonance, functional neuroimage techniques) and those properly neurophysiological; in the second place, the anatomopathological and physiopathological markers are examined; and, in the third place, those based on the modern genetic investigations. In the absence of an 'univocal biological marker', the current investigation about markers is on the way to the study of abnormal proteins discovered in the brain, of the modifications detected in the cellular metabolism, of the manifestations of the immunologic mechanisms and of the involved inflammatory processes, and is on the way to the advances and proximate perspectives of molecular genetics and animal models. Meanwhile, the diagnostic for the main dementia, due to Alzheimer's disease, is basically a clinic, exclusive and residual one, mainly in its initial stadium.

  16. Multiphoton imaging of biological samples during freezing and heating

    NASA Astrophysics Data System (ADS)

    Breunig, H. G.; Uchugonova, A.; König, K.

    2014-02-01

    We applied multiphoton microscopic imaging to observe freezing and heating effects in plant- and animal cell samples. The experimental setups consisted of a multiphoton imaging system and a heating and cooling stage which allows for precise temperature control from liquid nitrogen temperature (-196°C 77 K) up to +600°C (873 K) with heating/freezing rates between 0.01 K/min and 150 K/min. Two multiphoton imaging systems were used: a system based on a modified optical microscope and a flexible mobile system. To illustrate the imaging capabilities, plant leafs as well as animal cells were microscopically imaged in vivo during freezing based on autofluorescence lifetime and intensity of intrinsic molecules. The measurements illustrate the usefulness of multiphoton imaging to investigate freezing effects on animal and plant cells.

  17. Broad Consent For Research With Biological Samples: Workshop Conclusions

    PubMed Central

    Grady, Christine; Eckstein, Lisa; Berkman, Ben; Brock, Dan; Cook-Deegan, Robert; Fullerton, Stephanie M.; Greely, Hank; Hansson, Mats G.; Hull, Sara; Kim, Scott; Lo, Bernie; Pentz, Rebecca; Rodriguez, Laura; Weil, Carol; Wilfond, Benjamin S.; Wendler, David

    2016-01-01

    Different types of consent are used to obtain human biospecimens for future research. This variation has resulted in confusion regarding what research is permitted, inadvertent constraints on future research, and research proceeding without consent. The NIH Clinical Center’s Department of Bioethics held a workshop to consider the ethical acceptability of addressing these concerns by using broad consent for future research on stored biospecimens. Multiple bioethics scholars, who have written on these issues, discussed the reasons for consent, the range of consent strategies, gaps in our understanding, and concluded with a proposal for broad initial consent coupled with oversight and, when feasible, ongoing provision of information to donors. The manuscript describes areas of agreement as well as areas that need more research and dialogue. Given recent proposed changes to the Common Rule, and new guidance regarding storing and sharing data and samples, this is an important and timely topic. PMID:26305750

  18. Uniform Sampling Table Method and its Applications II--Evaluating the Uniform Sampling by Experiment.

    PubMed

    Chen, Yibin; Chen, Jiaxi; Chen, Xuan; Wang, Min; Wang, Wei

    2015-01-01

    A new method of uniform sampling is evaluated in this paper. The items and indexes were adopted to evaluate the rationality of the uniform sampling. The evaluation items included convenience of operation, uniformity of sampling site distribution, and accuracy and precision of measured results. The evaluation indexes included operational complexity, occupation rate of sampling site in a row and column, relative accuracy of pill weight, and relative deviation of pill weight. They were obtained from three kinds of drugs with different shape and size by four kinds of sampling methods. Gray correlation analysis was adopted to make the comprehensive evaluation by comparing it with the standard method. The experimental results showed that the convenience of uniform sampling method was 1 (100%), odds ratio of occupation rate in a row and column was infinity, relative accuracy was 99.50-99.89%, reproducibility RSD was 0.45-0.89%, and weighted incidence degree exceeded the standard method. Hence, the uniform sampling method was easy to operate, and the selected samples were distributed uniformly. The experimental results demonstrated that the uniform sampling method has good accuracy and reproducibility, which can be put into use in drugs analysis. PMID:26525264

  19. Observations of the Ca ii IR Triplet in High Luminosity Quasars: Exploring the Sample

    NASA Astrophysics Data System (ADS)

    Martínez-Aldama, Mary Loli; Marziani, Paola; Dultzin, Deborah; Sulentic, Jack W.; Bressan, Alessandro; Chen, Yang; Stirpe, Giovanna M.

    2015-12-01

    We present a new spectroscopic sample of 11 quasars at intermediate redshift observed with the Infrared Spectrometer and Array Camera (ISAAC) on the ESO Very Large Telescope (VLT), covering O i λ8446 and the Ca ii triplet 8498, 8542, 8662. The new observations - that supplement the sample presented by Martínez-Aldama et al. (2015) - allow us to confirm the constraints on physical conditions and location of the region emitting the low ionization lines, as well as the relation between Ca ii and Fe ii.

  20. Effects of Cd(II) on wastewater biological nitrogen and phosphorus removal.

    PubMed

    Chen, Hong-Bo; Wang, Dong-Bo; Li, Xiao-Ming; Yang, Qi; Luo, Kun; Zeng, Guang-Ming; Tang, Mao-Lin

    2014-12-01

    Short-term and long-term effects of Cd(II) on wastewater biological nitrogen and phosphorus removal were investigated with respect to microorganism abundances, enzyme activities, and polyhydroxyalkanoates (PHAs) and glycogen transformations. Though no obvious effects on wastewater biological nutrient removal were observed after short-term exposure, the long-term exposure of 10 mg L(-)(1) Cd(II) inhibited nitrification and phosphorus uptake. Compared with the absence of Cd(II), the presence of 10 mg L(-1) of Cd(II) decreased total nitrogen and phosphorus removal efficiencies from 97% and 98% to 88% and 18%, respectively. Mechanism studies revealed that Cd(II) affected the transformations of intracellular PHAs and glycogen, and the activities of oxidoreductase and polyphosphate kinase, resulted in the decrease of nitrite oxidizing bacteria and polyphosphate accumulating organisms abundance, which might be the major reason for the negative effects of long-term exposure to 10 mg L(-1) Cd(II) on biological nitrogen and phosphorus removal.

  1. Quantification of sparfloxacin in pharmaceutical dosages and biological samples.

    PubMed

    Shah, Jasmin; Jan, Muhammad Rasul; Khan, Inayatullah; Khan, Muhammad Naeem

    2012-10-01

    A simple and fast method for spectrophotometric determination of sparfloxacin using p-dimethyl-aminobenzaldehyde (DMAB) has been developed. A yellow coloured product formed from reaction between sparfloxacin and DMAB as a result of condensation reaction at room temperature. The maximum absorbance was found at 392 nm with molar absorptivity of 4.9 × 10(3) L mol(-1) cm(-1). All parameters for the reaction, as concentration of DMBA reagent, molarity of sulphuric acid, and reaction temperature were studied. Under the conditions studied, a linear relationship between absorbance of the condensation product and concentration of sparfloxacin in the range of 2.0-80.0 μg mL(-1) was found with good correlation coefficient (0.9997). The limits of detection (LOD) and quantification (LOQ) for the proposed method were found to be 0.22 and 0.75 μg mL(-1) respectively. The repeatability and accuracy (model) of the method was studied at three different concentrations of sparfloxacin and found with value of relative standard deviation less than 2.0%. The method was found selective for determination of sparfloxacin in the presence of commonly used excipients in dosage forms. The developed method was validated statistically and applied successfully to the analysis of the drug in pure form, pharmaceutical preparations, and spiked blood plasma and urine samples with good accuracy (real) and precision. The percentage recovery was found from 99.0-100.0% with relative standard deviation less than 1%. The results of the proposed method were compared statistically with the results of literature HPLC method.

  2. Hybrid molecular probe for nucleic acid analysis in biological samples.

    PubMed

    Yang, Chaoyong James; Martinez, Karen; Lin, Hui; Tan, Weihong

    2006-08-01

    The ability to detect changes in gene expression, especially in real-time and with sensitivity sufficient enough to monitor small variations in a single-cell, will have considerable value in biomedical research and applications. Out of the many available molecular probes for intracellular monitoring of nucleic acids, molecular beacon (MB) is the most frequently used probe with the advantages of high sensitivity and selectivity. However, any processes in which the MB stem-loop structure is broken will result in a restoration of the fluorescence in MB. This brings in a few possibilities for false positive signal such as nuclease degradation, protein binding, thermodynamic fluctuation, solution composition variations (such as pH, salt concentration) and sticky-end pairing. These unwanted processes do exist inside living cells, making nucleic acid monitoring inside living cells difficult. We have designed and synthesized a hybrid molecular probe (HMP) for intracellular nucleic acid monitoring to overcome these problems. HMP has two DNA probes, one labeled with a donor and the other an acceptor. The two DNA probes are linked by a poly(ethylene glycol) (PEG) linker, with each DNA being complementary to adjacent areas of a target sequence. Target binding event brings the donor and acceptor in proximity, resulting in quenching of the donor fluorescence and enhancement of the acceptor emission. The newly designed HMP has high sensitivity, selectivity, and fast hybridization kinetics. The probe is easy to design and synthesize. HMP does not generate any false positive signal upon digestion by nuclease, binding by proteins, forming complexes by sticky-end pairing, or by other molecular interaction processes. HMP is capable of selectively detecting nucleic acid targets from cellular samples.

  3. Penicillamine-modified sensor for the voltammetric determination of Cd(II) and Pb(II) ions in natural samples.

    PubMed

    Pérez-Ràfols, Clara; Serrano, Núria; Díaz-Cruz, José Manuel; Ariño, Cristina; Esteban, Miquel

    2015-11-01

    A new penicillamine-GCE was developed based on the immobilization of d-penicillamine on aryl diazonium salt monolayers anchored to the glassy carbon electrode (GCE) surface and it was applied for the first time to the simultaneous determination of Cd(II) and Pb(II) ions by stripping voltammetric techniques. The detection and quantification limits at levels of µg L(-1) suggest that the penicillamine-GCE could be fully suitable for the determination of the considered ions in natural samples. PMID:26452863

  4. Chemical abundances in LMC stellar populations. II. The bar sample

    NASA Astrophysics Data System (ADS)

    Van der Swaelmen, M.; Hill, V.; Primas, F.; Cole, A. A.

    2013-12-01

    favour of an episode of enhanced star formation a few Gyr ago, occurring in the central parts of the LMC and leading to the formation of the bar. This is in agreement with recently derived star formation histories. Proposals 072.B-0293(B) and 078.B-0323(A), P.I. Vanessa Hill.Full Tables 3, 5, 7, 9, 11 and abundances tables for the LMC bar and disc samples are only available in electronic form at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/560/A44Table 11 is also available in electronic form at http://www.aanda.org

  5. Synthesis, Structural Characterization, and Biological Activity Studies of Ni(II) and Zn(II) Complexes

    PubMed Central

    Kavitha, Palakuri; Laxma Reddy, K.

    2014-01-01

    Ni(II) and Zn(II) complexes were synthesized from tridentate 3-formyl chromone Schiff bases such as 3-((2-hydroxyphenylimino)methyl)-4H-chromen-4-one (HL1), 2-((4-oxo-4H-chromen-3-yl)methylneamino)benzoic acid (HL2), 3-((3-hydroxypyridin-2-ylimino)methyl)-4H-chromen-4-one (HL3), and 3-((2-mercaptophenylimino)methyl)-4H-chromen-4-one (HL4). All the complexes were characterized in the light of elemental analysis, molar conductance, FTIR, UV-VIS, magnetic, thermal, powder XRD, and SEM studies. The conductance and spectroscopic data suggested that, the ligands act as neutral and monobasic tridentate ligands and form octahedral complexes with general formula [M(L1–4)2]·nH2O (M = Ni(II) and Zn(II)). Metal complexes exhibited pronounced activity against tested bacteria and fungi strains compared to the ligands. In addition metal complexes displayed good antioxidant and moderate nematicidal activities. The cytotoxicity of ligands and their metal complexes have been evaluated by MTT assay. The DNA cleavage activity of the metal complexes was performed using agarose gel electrophoresis in the presence and absence of oxidant H2O2. All metal complexes showed significant nuclease activity in the presence of H2O2. PMID:24948904

  6. The effect of sterilization on biological, organic geochemical and morphological information in natural samples

    NASA Technical Reports Server (NTRS)

    Hochstein, L. I.; Kvenvolden, K. A.; Philpott, D. E.

    1974-01-01

    The loss of biological, organic geochemical, and morphological science information that may occur should a Mars surface sample be sterilized prior to return to earth is examined. Results of experimental studies are summarized.

  7. Utility of solid-phase spectrophotometry to determine trace amounts of zinc in environmental and biological samples.

    PubMed

    Amin, Alaa S

    2011-11-15

    A solid-phase spectrophotometric analysis has been proposed for preconcentration and determination of Zn(II) in real samples. The procedure is based on sorption of zinc(II) as 5-(2-benzothiazolylazo)-8-hydroxyquinoline (BTAHQ) complex on dextran-type anion-exchange gel (Sephadex DEAE A-25). The influences of the analytical parameters, including pH of the aqueous solution, amounts of BTAHQ, and sample volume, were investigated. The absorbance of the gel at 675 and 750 nm, packed in a 1.0-mm cell, was measured directly. The molar absorptivities were found to be 2.50×10(7) and 9.55×10(7)L mol(-1) cm(-1) for 500 and 1000 ml, respectively. Calibration was linear over the range of 0.05-1.10 μg L(-1) with a relative standard deviation of less than 1.60% (n=10). The detection and quantification limits of the 500-ml sample method were 12 and 40 ng L(-1) on using 50 mg. For the 1000-ml sample, the detection and quantification limits were 7.5 and 25 ng L(-1) using a 50-mg exchanger. Increasing the sample volume can enhance sensitivity. No considerable interferences were observed from other investigated anions and cations on the Zn(II) determination. The proposed method was applied to determine zinc in environmental samples, including natural water, food, certified reference materials, meat, and biological samples, comparing the results simultaneously with those obtained using a flame atomic absorption spectrophotometer, whereby the validity of the method was tested. PMID:21820999

  8. Determination of Pb(II), Zn(II), Cd(II), and Co(II) ions by flame atomic absorption spectrometry in food and water samples after preconcentration by coprecipitation with Mo(VI)-diethyldithiocarbamate.

    PubMed

    Tufekci, Mehmet; Bulut, Volkan Numan; Elvan, Hamide; Ozdes, Duygu; Soylak, Mustafa; Duran, Celal

    2013-02-01

    A new, simple, and rapid separation and preconcentration procedure, for determination of Pb(II), Cd(II), Zn(II), and Co(II) ions in environmental real samples, has been developed. The method is based on the combination of coprecipitation of analyte ions by the aid of the Mo(VI)-diethyldithiocarbamate-(Mo(VI)-DDTC) precipitate and flame atomic absorption spectrometric determinations. The effects of experimental conditions like pH of the aqueous solution, amounts of DDTC and Mo(VI), standing time, centrifugation rate and time, sample volume, etc. and also the influences of some foreign ions were investigated in detail on the quantitative recoveries of the analyte ions. The preconcentration factors were found to be 150 for Pb(II), Zn(II) and Co(II), and 200 for Cd(II) ions. The detection limits were in the range of 0.1-2.2 μg L(-1) while the relative standard deviations were found to be lower than 5 % for the studied analyte ions. The accuracy of the method was checked by spiked/recovery tests and the analysis of certified reference material (CRM TMDW-500 Drinking Water). The procedure was successfully applied to seawater and stream water as liquid samples and baby food and dried eggplant as solid samples in order to determine the levels of Pb(II), Cd(II), Zn(II), and Co(II) ions. PMID:22527456

  9. Epigenetic Segregation of Microbial Genomes from Complex Samples Using Restriction Endonucleases HpaII and McrB

    PubMed Central

    Liu, Guohong; Weston, Christopher Q.; Pham, Long K.; Waltz, Shannon; Barnes, Helen; King, Paula; Sphar, Dan; Yamamoto, Robert T.; Forsyth, R. Allyn

    2016-01-01

    We describe continuing work to develop restriction endonucleases as tools to enrich targeted genomes of interest from diverse populations. Two approaches were developed in parallel to segregate genomic DNA based on cytosine methylation. First, the methyl-sensitive endonuclease HpaII was used to bind non-CG methylated DNA. Second, a truncated fragment of McrB was used to bind CpG methylated DNA. Enrichment levels of microbial genomes can exceed 100-fold with HpaII allowing improved genomic detection and coverage of otherwise trace microbial genomes from sputum. Additionally, we observe interesting enrichment results that correlate with the methylation states not only of bacteria, but of fungi, viruses, a protist and plants. The methods presented here offer promise for testing biological samples for pathogens and global analysis of population methylomes. PMID:26727463

  10. Minutes of the 28th Annual Plutonium Sample Exchange Meeting. Part II: metal sample exchange

    SciTech Connect

    Not Available

    1984-01-01

    Contents of this publication include the following list of participating laboratories; agenda; attendees; minutes of October 25 and 26 meeting; and handout materials supplied by speakers. The handout materials cover the following: statistics and reporting; plutonium - chemical assay 100% minus impurities; americium neptunium, uranium, carbon and iron data; emission spectroscopy data; plutonium metal sample exchange; the calorimetry sample exchange; chlorine determination in plutonium metal using phyrohydrolysis; spectrophotometric determination of 238-plutonium in oxide; plutonium measurement capabilities at the Savannah River Plant; and robotics in radiochemical laboratory.

  11. Biology of the tribe Ambelanieae (apocynaceae). Volumes I and II

    SciTech Connect

    Zarucchi, J.L.

    1982-01-01

    The tribe Ambelanieae consists of seventeen species of latex-bearing shrubs and trees in six genera found in the tropical lowlands of norther South America. The center of distribution as well as diversification for the Ambelanieae is the Rio Negro basin of Brazilian Amazonia. This study is based on field observations of representative species from five of the genera, supplemented by the examination of exsiccatae from the major herbaria of the world. The analysis includes a review of the taxonomic history, a presentation of a systematic treatment for the genera and species, and detailed discussions of morphology, anatomy, ecology, pollination, fruit dispersal, phenology, palynology, cytology, and biogeography. The first chromosome numbers for the tribe are reported, indicating that polyploidy occurs within the group. Pollen variability is demonstrated, not only among species of different genera but also within individual pollen samples. In reference to economic uses, some members of the tribe are suggested to hold promise for exploitation of usable latex, lightweight wood, and edible fruits. The presence of potentially important toxic and medicinal principles from several species is indicated by ethnopharmacological observations made in the northwest Amazon basin.

  12. Evaluation of pump pulsation in respirable size-selective sampling: part II. Changes in sampling efficiency.

    PubMed

    Lee, Eun Gyung; Lee, Taekhee; Kim, Seung Won; Lee, Larry; Flemmer, Michael M; Harper, Martin

    2014-01-01

    This second, and concluding, part of this study evaluated changes in sampling efficiency of respirable size-selective samplers due to air pulsations generated by the selected personal sampling pumps characterized in Part I (Lee E, Lee L, Möhlmann C et al. Evaluation of pump pulsation in respirable size-selective sampling: Part I. Pulsation measurements. Ann Occup Hyg 2013). Nine particle sizes of monodisperse ammonium fluorescein (from 1 to 9 μm mass median aerodynamic diameter) were generated individually by a vibrating orifice aerosol generator from dilute solutions of fluorescein in aqueous ammonia and then injected into an environmental chamber. To collect these particles, 10-mm nylon cyclones, also known as Dorr-Oliver (DO) cyclones, were used with five medium volumetric flow rate pumps. Those were the Apex IS, HFS513, GilAir5, Elite5, and Basic5 pumps, which were found in Part I to generate pulsations of 5% (the lowest), 25%, 30%, 56%, and 70% (the highest), respectively. GK2.69 cyclones were used with the Legacy [pump pulsation (PP) = 15%] and Elite12 (PP = 41%) pumps for collection at high flows. The DO cyclone was also used to evaluate changes in sampling efficiency due to pulse shape. The HFS513 pump, which generates a more complex pulse shape, was compared to a single sine wave fluctuation generated by a piston. The luminescent intensity of the fluorescein extracted from each sample was measured with a luminescence spectrometer. Sampling efficiencies were obtained by dividing the intensity of the fluorescein extracted from the filter placed in a cyclone with the intensity obtained from the filter used with a sharp-edged reference sampler. Then, sampling efficiency curves were generated using a sigmoid function with three parameters and each sampling efficiency curve was compared to that of the reference cyclone by constructing bias maps. In general, no change in sampling efficiency (bias under ±10%) was observed until pulsations exceeded 25% for the

  13. Evaluation of Pump Pulsation in Respirable Size-Selective Sampling: Part II. Changes in Sampling Efficiency

    PubMed Central

    Lee, Eun Gyung; Lee, Taekhee; Kim, Seung Won; Lee, Larry; Flemmer, Michael M.; Harper, Martin

    2015-01-01

    This second, and concluding, part of this study evaluated changes in sampling efficiency of respirable size-selective samplers due to air pulsations generated by the selected personal sampling pumps characterized in Part I (Lee E, Lee L, Möhlmann C et al. Evaluation of pump pulsation in respirable size-selective sampling: Part I. Pulsation measurements. Ann Occup Hyg 2013). Nine particle sizes of monodisperse ammonium fluorescein (from 1 to 9 μm mass median aerodynamic diameter) were generated individually by a vibrating orifice aerosol generator from dilute solutions of fluorescein in aqueous ammonia and then injected into an environmental chamber. To collect these particles, 10-mm nylon cyclones, also known as Dorr-Oliver (DO) cyclones, were used with five medium volumetric flow rate pumps. Those were the Apex IS, HFS513, GilAir5, Elite5, and Basic5 pumps, which were found in Part I to generate pulsations of 5% (the lowest), 25%, 30%, 56%, and 70% (the highest), respectively. GK2.69 cyclones were used with the Legacy [pump pulsation (PP) = 15%] and Elite12 (PP = 41%) pumps for collection at high flows. The DO cyclone was also used to evaluate changes in sampling efficiency due to pulse shape. The HFS513 pump, which generates a more complex pulse shape, was compared to a single sine wave fluctuation generated by a piston. The luminescent intensity of the fluorescein extracted from each sample was measured with a luminescence spectrometer. Sampling efficiencies were obtained by dividing the intensity of the fluorescein extracted from the filter placed in a cyclone with the intensity obtained from the filter used with a sharp-edged reference sampler. Then, sampling efficiency curves were generated using a sigmoid function with three parameters and each sampling efficiency curve was compared to that of the reference cyclone by constructing bias maps. In general, no change in sampling efficiency (bias under ±10%) was observed until pulsations exceeded 25% for the

  14. Restricted accessed material-copper(II) ion imprinted polymer solid phase extraction combined with inductively coupled plasma-optical emission spectrometry for the determination of free Cu(II) in urine and serum samples.

    PubMed

    Cui, Chao; He, Man; Chen, Beibei; Hu, Bin

    2013-11-15

    A novel restricted accessed material (RAM)-Cu(II) ion imprinted polymer (IIP) was synthesized by the surface imprinted-emulsion method, and possessed a high selectivity to Cu(II) and good macromolecules exclusion property. And a novel method of RAM-IIP packed microcolumn solid phase extraction (SPE) combined with inductively coupled plasma-optical emission spectrometry (ICP-OES) was developed for the determination of trace free Cu(II) in human body fluids. Under the optimized conditions, the adsorption capacity of RAM-IIP for Cu(II) was 15.9 mg g(-1). With a preconcentration factor of 30, the limit of detection was 0.17 µg L(-1), and the relative standard deviation was 2.2% (n=7, c=1 µg L(-1)). The developed method was validated by the analysis of two Certified Reference Materials, and the determined values were in good agreement with the certified values. This method was also successfully applied for the direct analysis of free Cu(II) in human urine and serum samples. While the total Cu can be determined by the proposed method after microwave digestion. The concentrations of free Cu(II) were much lower than that of total Cu, indicating that Cu is mainly coordinated with macromolecules in these biological samples. From this point of view, the developed method exhibits application potential in speciation of free metal ions and metallic complex molecules in biological samples. PMID:24148513

  15. Sampling Almonds for Aflatoxin, Part II: Estimating Risks Associated with Various Sampling Plans Designs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    About 100 nations have established regulatory limits for aflatoxin in food and feeds. Because these limits vary widely from one country to another, FAO/WHO working through the Codex Committee on Food Additives and Contaminants (CCFAC) has initiated work to harmonize aflatoxin limits and sampling pla...

  16. Multielement analysis of micro-volume biological samples by ICP-MS with highly efficient sample introduction system.

    PubMed

    Takasaki, Yuka; Inagaki, Kazumi; Sabarudin, Akhmad; Fujii, Shin-Ichiro; Iwahata, Daigo; Takatsu, Akiko; Chiba, Koichi; Umemura, Tomonari

    2011-12-15

    A method for multielement analysis of micro-volume biological sample by inductively coupled plasma mass spectrometry (ICP-MS) with a highly efficient sample introduction system was presented. The sample introduction system was the combination of (1) an inert loop injection unit and (2) a high performance concentric nebulizer (HPCN) coupled with a temperature controllable cyclone chamber. The loop injection unit could introduce 20 μL samples into the carrier liquid flow of 10 μL min(-1) producing a stable signal for 100s without any dilution. The injection loop is continuously washed with 0.1M HNO(3) carrier solution during the measurement, thereby much improving sample throughput. The HPCN is a triple tube concentric nebulizer, which can generate fine aerosols and provide a stable and highly measurement sensitivity in ICP-MS at a liquid flow rate less than 10 μL min(-1). With the combination of the chamber heating at 60°C, the sensitivity obtained with the proposed sample introduction system at the liquid flow rate of 10 μL min(-1) was almost the same as that with a common concentric nebulizer and cyclone chamber system at the liquid flow rate of 1 mL min(-1), though the sample consumption rate of the HPCN was two orders of the magnitude lower than that of the common nebulizer. The validation of the proposed system was performed by analyzing the NIST SRM 1577b Bovine Liver. The observed values for 12 elements such as Na, P, S, K, Ca, Mn, Fe, Co, Cu, Zn, Mo, Cd were in good agreement with their certified values and information value. Satisfactory analytical results for 14 elements such as Na, Mg, P, S, K, Ca, Cr, Mn, Fe, Ni, Cu, Zn, Y, Ba in Escherichia coli sample were also obtained. The proposed sample introduction system was quite effective in the cases when only micro-volume of biological sample is available. PMID:22099643

  17. Near infrared fluorescence quenching properties of copper (II) ions for potential applications in biological imaging

    NASA Astrophysics Data System (ADS)

    Maji, Dolonchampa; Zhou, Mingzhou; Sarder, Pinaki; Achilefu, Samuel

    2014-03-01

    Fluorescence quenching properties of copper(II) ions have been used for designing Cu(II) sensitive fluorescent molecular probes. In this paper, we demonstrate that static quenching plays a key role in free Cu(II)-mediated fluorescence quenching of a near infrared (NIR) fluorescent dye cypate. The Stern-Volmer quenching constant was calculated to be KSV = 970,000 M-1 in 25 mM MES buffer, pH 6.5 at room temperature. We synthesized LS835, a compound containing cypate attached covalently to chelated Cu(II) to study fluorescence quenching by chelated Cu(II). The fluorescence quenching mechanism of chelated Cu(II) is predominantly dynamic or collisional quenching. The quenching efficiency of chelated Cu(II) was calculated to be 58% ± 6% in dimethylsulfoxide at room temperature. Future work will involve further characterization of the mechanism of NIR fluorescence quenching by Cu(II) and testing its reversibility for potential applications in designing fluorophore-quencher based molecular probes for biological imaging.

  18. Psychometric properties of the Beck Depression Inventory-II in nonclinical adolescent samples.

    PubMed

    Osman, Augustine; Barrios, Francisco X; Gutierrez, Peter M; Williams, John E; Bailey, Jennifer

    2008-01-01

    This study examined the factor structure and psychometric properties of the Beck Depression Inventory-II (BDI-II; A. T. Beck, Steer, & Brown, 1996) in samples of high-school adolescents (N=414; 210 boys and 204 girls, ages 14-18 years). Confirmatory factor analyses provided satisfactory fit estimates for the two- and three-factor oblique solutions reported frequently in the extant literature. The solution to a general factor with domain-specific somatic and cognitive-affective factors was examined as an alternative model to previously established models for the current high-school sample data. Results provided stronger support for the general factor model. Estimates of internal consistency for scores on this instrument were high (coefficient alpha=.92, average interitem correlation=.35). The mean BDI-II total score for the nonclinical samples (M=12.50, SD=10.50) was compared with the mean scores reported for various adolescent normative samples in the extant literature. The BDI-II total score correlated moderately and significantly with scores on self-report measures of hopelessness (r=.63), anxiety (r=.53), and suicide-related behaviors (r=.57), providing support of adequate correlates for the BDI-II. Estimates of known-groups validity were evaluated using data from a small sample of 167 clinical adolescent inpatients. Specific study findings, limitations, and recommendations are discussed. PMID:18161034

  19. Analysis of low-angle x-ray scattering peaks from lyophilized biological samples

    NASA Astrophysics Data System (ADS)

    Desouky, Omar S.; Elshemey, Wael M.; Selim, Nabila S.; Ashour, Ahmed H.

    2001-08-01

    Low-angle x-ray scattering (LAXS) from lyophilized blood and its constituents is characterized by the presence of two peaks in the forward direction of scattering. These peaks are found to be sensitive to the variations in the molecular structure of a given sample. The present work aims to explore the nature of LAXS from a variety of lyophilized biological samples. It also aims to investigate the possibility that a certain biological macromolecule is responsible of the production of LAXS peaks. This is carried out through measurements of LAXS from complex biological samples and their basic constituents. Among the measured samples are haemoglobin (Hb), globin, haem, packed red blood cells, bovine albumin, egg albumin, milk, casein, glutamine, alanine, fat, muscle and DNA. A table containing some characteristic parameters of the LAXS profiles of these samples is also presented. Analysis of measured profiles shows that all lyophilized samples produce at least one relatively broad peak at a scattering angle around 10.35°. The full width at half maximum (FWHM) of this peak varies considerably among the measured samples. Except for milk and casein, one additional peak at a scattering angle around 4.65° is observed only in the LAXS profiles of proteins or protein-rich samples. This fact strongly suggests protein to be the biological macromolecule from which this characteristic peak originates. The same idea is further strengthened through discussion of some previous observations.

  20. Operable Unit 3-13, Group 3, Other Surface Soils (Phase II) Field Sampling Plan

    SciTech Connect

    G. L. Schwendiman

    2006-07-27

    This Field Sampling Plan describes the Operable Unit 3-13, Group 3, Other Surface Soils, Phase II remediation field sampling activities to be performed at the Idaho Nuclear Technology and Engineering Center located within the Idaho National Laboratory Site. Sampling activities described in this plan support characterization sampling of new sites, real-time soil spectroscopy during excavation, and confirmation sampling that verifies that the remedial action objectives and remediation goals presented in the Final Record of Decision for Idaho Nuclear Technology and Engineering Center, Operable Unit 3-13 have been met.

  1. Synthesis, fluorescence study and biological evaluation of three Zn(II) complexes with Paeonol Schiff base

    NASA Astrophysics Data System (ADS)

    Qin, Dong-dong; Yang, Zheng-yin; Qi, Gao-fei

    2009-10-01

    The synthesis of three Paeonol Schiff base ligand and their Zn(II) complexes are reported. The complexes were fully characterized by IR, 1H NMR, elemental analysis and molar conductivity. The experiment results show the three Zn(II) complexes can emit bright fluorescence at room temperature in DMF solution and solid state. The fluorescence quantum yields ( Φ) of three Schiff base ligands and their Zn(II) complexes were calculated using quinine sulfate as the reference with a known ΦR of 0.546 in 1.0N sulfuric acid. Furthermore, in order to develop these Zn(II) complexes' biological value, the antioxidant activities against hydroxyl radicals (OH rad ) were evaluated. The results show the three complexes possess excellent ability to scavenge hydroxyl radicals.

  2. Chromosome aberrations induced in human lymphocytes by U-235 fission neutrons: I. Irradiation of human blood samples in the "dry cell" of the TRIGA Mark II nuclear reactor.

    PubMed

    Fajgelj, A; Lakoski, A; Horvat, D; Remec, I; Skrk, J; Stegnar, P

    1991-11-01

    A set-up for irradiation of biological samples in the TRIGA Mark II research reactor in Ljubljana is described. Threshold activation detectors were used for characterisation of the neutron flux, and the accompanying gamma dose was measured by TLDs. Human peripheral blood samples were irradiated "in vitro" and biological effects evaluated according to the unstable chromosomal aberrations induced. Biological effects of two types of cultivation of irradiated blood samples, the first immediately after irradiation and the second after 96 h storage, were studied. A significant difference in the incidence of chromosomal aberrations between these two types of samples was obtained, while our dose-response curve fitting coefficients alpha 1 = (7.71 +/- 0.09) x 10(-2) Gy-1 (immediate cultivation) and alpha 2 = (11.03 +/- 0.08) x 10(-2) Gy-1 (96 h delayed cultivation) are in both cases lower than could be found in the literature.

  3. Chromosome aberrations induced in human lymphocytes by U-235 fission neutrons: I. Irradiation of human blood samples in the "dry cell" of the TRIGA Mark II nuclear reactor.

    PubMed

    Fajgelj, A; Lakoski, A; Horvat, D; Remec, I; Skrk, J; Stegnar, P

    1991-11-01

    A set-up for irradiation of biological samples in the TRIGA Mark II research reactor in Ljubljana is described. Threshold activation detectors were used for characterisation of the neutron flux, and the accompanying gamma dose was measured by TLDs. Human peripheral blood samples were irradiated "in vitro" and biological effects evaluated according to the unstable chromosomal aberrations induced. Biological effects of two types of cultivation of irradiated blood samples, the first immediately after irradiation and the second after 96 h storage, were studied. A significant difference in the incidence of chromosomal aberrations between these two types of samples was obtained, while our dose-response curve fitting coefficients alpha 1 = (7.71 +/- 0.09) x 10(-2) Gy-1 (immediate cultivation) and alpha 2 = (11.03 +/- 0.08) x 10(-2) Gy-1 (96 h delayed cultivation) are in both cases lower than could be found in the literature. PMID:1962281

  4. Helium Ion Microscopy (HIM) for the imaging of biological samples at sub-nanometer resolution

    PubMed Central

    Joens, Matthew S.; Huynh, Chuong; Kasuboski, James M.; Ferranti, David; Sigal, Yury J.; Zeitvogel, Fabian; Obst, Martin; Burkhardt, Claus J.; Curran, Kevin P.; Chalasani, Sreekanth H.; Stern, Lewis A.; Goetze, Bernhard; Fitzpatrick, James A. J.

    2013-01-01

    Scanning Electron Microscopy (SEM) has long been the standard in imaging the sub-micrometer surface ultrastructure of both hard and soft materials. In the case of biological samples, it has provided great insights into their physical architecture. However, three of the fundamental challenges in the SEM imaging of soft materials are that of limited imaging resolution at high magnification, charging caused by the insulating properties of most biological samples and the loss of subtle surface features by heavy metal coating. These challenges have recently been overcome with the development of the Helium Ion Microscope (HIM), which boasts advances in charge reduction, minimized sample damage, high surface contrast without the need for metal coating, increased depth of field, and 5 angstrom imaging resolution. We demonstrate the advantages of HIM for imaging biological surfaces as well as compare and contrast the effects of sample preparation techniques and their consequences on sub-nanometer ultrastructure. PMID:24343236

  5. Helium Ion Microscopy (HIM) for the imaging of biological samples at sub-nanometer resolution.

    PubMed

    Joens, Matthew S; Huynh, Chuong; Kasuboski, James M; Ferranti, David; Sigal, Yury J; Zeitvogel, Fabian; Obst, Martin; Burkhardt, Claus J; Curran, Kevin P; Chalasani, Sreekanth H; Stern, Lewis A; Goetze, Bernhard; Fitzpatrick, James A J

    2013-12-17

    Scanning Electron Microscopy (SEM) has long been the standard in imaging the sub-micrometer surface ultrastructure of both hard and soft materials. In the case of biological samples, it has provided great insights into their physical architecture. However, three of the fundamental challenges in the SEM imaging of soft materials are that of limited imaging resolution at high magnification, charging caused by the insulating properties of most biological samples and the loss of subtle surface features by heavy metal coating. These challenges have recently been overcome with the development of the Helium Ion Microscope (HIM), which boasts advances in charge reduction, minimized sample damage, high surface contrast without the need for metal coating, increased depth of field, and 5 angstrom imaging resolution. We demonstrate the advantages of HIM for imaging biological surfaces as well as compare and contrast the effects of sample preparation techniques and their consequences on sub-nanometer ultrastructure.

  6. Toward the realization of reproducible Atomic Force Microscopy measurements of elastic modulus in biological samples.

    PubMed

    Demichelis, A; Divieto, C; Mortati, L; Pavarelli, S; Sassi, G; Sassi, M P

    2015-04-13

    The validation of the AFM method for elastic modulus E measurement in soft materials (E <5 MPa) is still missing. The interest of measurements in materials with E <5 MPa is mainly biological, including soft tissues and single cells. For the diagnosis of malignant human tumors, a change in cell elasticity, within tissues, has recently been recognized as a marker of metastatic potential. To measure a cell elasticity difference, reproducible E measurements in biological samples are needed. In this work a robust method for a metrological validation of E measurements in the range 500-5000 kPa was developed, based on the realization of thick E standard samples and on the study of the interactions between the measurement process and the sample at micro- and nano-scale. E measurement reproducibility limit of 4% has been reached. This allows designing a very sensitive and reproducible measurement of E in biological samples representing thus a powerful diagnostic tool for cancer detection.

  7. Improved Butanol-Methanol (BUME) Method by Replacing Acetic Acid for Lipid Extraction of Biological Samples.

    PubMed

    Cruz, Mutya; Wang, Miao; Frisch-Daiello, Jessica; Han, Xianlin

    2016-07-01

    Extraction of lipids from biological samples is a critical step in lipidomics, especially for shotgun lipidomics where lipid extracts are directly infused into a mass spectrometer. The butanol-methanol (BUME) extraction method was originally developed to extract lipids from plasma samples with 1 % acetic acid. Considering some lipids are sensitive to acidic environments, we modified this protocol by replacing acetic acid with lithium chloride solution and extended the modified extraction to tissue samples. Although no significant reduction of plasmalogen levels in the acidic BUME extracts of rat heart samples was found, the modified method was established to extract various tissue samples, including rat liver, heart, and plasma. Essentially identical profiles of the majority of lipid classes were obtained from the extracts of the modified BUME and traditional Bligh-Dyer methods. However, it was found that neither the original, nor the modified BUME method was suitable for 4-hydroxyalkenal species measurement in biological samples. PMID:27245345

  8. Membrane materials for storing biological samples intended for comparative nanotoxicological testing

    NASA Astrophysics Data System (ADS)

    Metelkin, A.; Kuznetsov, D.; Kolesnikov, E.; Chuprunov, K.; Kondakov, S.; Osipov, A.; Samsonova, J.

    2015-11-01

    The study is aimed at identifying the samples of most promising membrane materials for storing dry specimens of biological fluids (Dried Blood Spots, DBS technology). Existing sampling systems using cellulose fiber filter paper have a number of drawbacks such as uneven distribution of the sample spot, dependence of the spot spreading area on the individual biosample properties, incomplete washing-off of the sample due to partially inconvertible sorption of blood components on cellulose fibers, etc. Samples of membrane materials based on cellulose, polymers and glass fiber with applied biosamples were studied using methods of scanning electron microscopy, FT-IR spectroscopy and surface-wetting measurement. It was discovered that cellulose-based membrane materials sorb components of biological fluids inside their structure, while membranes based on glass fiber display almost no interaction with the samples and biological fluid components dry to films in the membrane pores between the structural fibers. This characteristic, together with the fact that membrane materials based on glass fiber possess sufficient strength, high wetting properties and good storage capacity, attests them as promising material for dry samples of biological fluids storage systems.

  9. Absorption and Diffusion Measurements of Biological Samples using a THz Free Electron Laser.

    PubMed

    Giovenale, E; D'Arienzo, M; Doria, A; Gallerano, G P; Lai, A; Messina, G; Piccinelli, D

    2003-06-01

    A compact THz Free Electron Laser (FEL) isbeing used to perform irradiation ofbiological samples to investigate possiblegenotoxic effects. In order to evaluate theexact radiation dose absorbed by the singlecomponents of the samples it is necessaryto study the optical properties of thesamples, separating the contributions tothe radiation attenuation coefficientcoming from absorption and from diffusion.Spectroscopic measurements have beenperformed on different biological samples, comparing the experimental results withtheoretical models. PMID:23345832

  10. A versatile and highly sensitive probe for Hg(II), Pb(II) and Cd(II) detection individually and totally in water samples.

    PubMed

    Zhou, Yu; Tian, Xiang-Li; Li, Yan-Song; Zhang, Yuan-Yuan; Yang, Li; Zhang, Jun-Hui; Wang, Xin-Rui; Lu, Shi-Ying; Ren, Hong-Lin; Liu, Zeng-Shan

    2011-12-15

    The detection of heavy metal ions using enzyme-linked immunosorbent assays (ELISA) has been reported by several research groups. However, highly sensitive and selective detection of total heavy metal ions using ELISA is a major technical limitation. Here we describe the development of a versatile and highly sensitive probe combining goat anti-mice IgG, colloidal gold nanoparticles (AuNPs) and horseradish peroxidase (HRP). We demonstrate the utility of this probe using three kinds of heavy metal complete antigens and three monoclonal antibodies (McAbs) in one ELISA system to establish a high-throughput screening protocol. The procedure was successfully applied to analysis of Hg(II), Pb(II) and Cd(II) individually and totally from different water samples. The sensitivities for the detection of Hg(II), Pb(II) and Cd(II) individually and totally are 27.4, 3.9, 15.8 and 18.2 nM, respectively. And all limit of detection (LODs) are lower than 1.2 nM. The recovery results obtained from the developed technique showed a good correlation (R(2)=0.983) with those from ICP-MS. The major advantage of the probe is the versatility and high sensibility. The probe could be potentially used, upon demand, as a sensitive and versatile detector for a broad range of applications. PMID:21975341

  11. Determination of selenium in biological samples with an energy-dispersive X-ray fluorescence spectrometer.

    PubMed

    Li, Xiaoli; Yu, Zhaoshui

    2016-05-01

    Selenium is both a nutrient and a toxin. Selenium-especially organic selenium-is a core component of human nutrition. Thus, it is very important to measure selenium in biological samples. The limited sensitivity of conventional XRF hampers its widespread use in biological samples. Here, we describe the use of high-energy (100kV, 600W) linearly polarized beam energy-dispersive X-Ray fluorescence spectroscopy (EDXRF) in tandem with a three-dimensional optics design to determine 0.1-5.1μgg(-1) levels of selenium in biological samples. The effects of various experimental parameters such as applied voltage, acquisition time, secondary target and various filters were thoroughly investigated. The detection limit of selenium in biological samples via high-energy (100kV, 600W) linearly polarized beam energy-dispersive X-ray fluorescence spectroscopy was decreased by one order of magnitude versus conventional XRF (Paltridge et al., 2012) and found to be 0.1μg/g. To the best of our knowledge, this is the first report to describe EDXRF measurements of Se in biological samples with important implications for the nutrition and analytical chemistry communities. PMID:26922394

  12. Simultaneous determination of trace cadmium and arsenic in biological samples by hydride generation-double channel atomic fluorescence spectrometry.

    PubMed

    Lu, Yun-kai; Sun, Han-Wen; Yuan, Chun-Gang; Yan, Xiu-Ping

    2002-04-01

    Hydride generation atomic fluorescence spectrometry (HG-AFS) has been used for determination of hydride-forming elements because of its high sensitivity, simplicity, and low costs, but most of such work has been concentrated on single element analysis, and reports dealing with multielement determination by HG-nondispersive (ND)AFS are rare. In this work, a sensitive HG-NDAFS method was developed for simultaneous determination of trace cadmium and arsenic in biological materials. The conditions for the generation of volatile cadmium and arsenic species from the reaction with KBH4 in aqueous solution were investigated using a double-channel AFS integrated with an intermittent flow reactor. Like thiourea and Co(II), ascorbic acid was found to significantly enhance the generation efficiency of volatile Cd and As species. The interferences of coexisting ions were evaluated. Under optimal conditions, the detection limits for Cd and As were determined to be 10 and 150 ng L(-1), respectively. The precision for 11 replicate determinations at the 1 microg L(-1) Cd level and the 10 microg L(-1) As level were 3.5 and 2.7% (RSD), respectively. The recoveries of spike analytes in the biological samples studied ranged from 94 to 109%. The proposed method was successfully applied to the simultaneous determination of Cd and As in a variety of biological samples.

  13. Chemometric and Statistical Analyses of ToF-SIMS Spectra of Increasingly Complex Biological Samples

    SciTech Connect

    Berman, E S; Wu, L; Fortson, S L; Nelson, D O; Kulp, K S; Wu, K J

    2007-10-24

    Characterizing and classifying molecular variation within biological samples is critical for determining fundamental mechanisms of biological processes that will lead to new insights including improved disease understanding. Towards these ends, time-of-flight secondary ion mass spectrometry (ToF-SIMS) was used to examine increasingly complex samples of biological relevance, including monosaccharide isomers, pure proteins, complex protein mixtures, and mouse embryo tissues. The complex mass spectral data sets produced were analyzed using five common statistical and chemometric multivariate analysis techniques: principal component analysis (PCA), linear discriminant analysis (LDA), partial least squares discriminant analysis (PLSDA), soft independent modeling of class analogy (SIMCA), and decision tree analysis by recursive partitioning. PCA was found to be a valuable first step in multivariate analysis, providing insight both into the relative groupings of samples and into the molecular basis for those groupings. For the monosaccharides, pure proteins and protein mixture samples, all of LDA, PLSDA, and SIMCA were found to produce excellent classification given a sufficient number of compound variables calculated. For the mouse embryo tissues, however, SIMCA did not produce as accurate a classification. The decision tree analysis was found to be the least successful for all the data sets, providing neither as accurate a classification nor chemical insight for any of the tested samples. Based on these results we conclude that as the complexity of the sample increases, so must the sophistication of the multivariate technique used to classify the samples. PCA is a preferred first step for understanding ToF-SIMS data that can be followed by either LDA or PLSDA for effective classification analysis. This study demonstrates the strength of ToF-SIMS combined with multivariate statistical and chemometric techniques to classify increasingly complex biological samples

  14. Genomes, neurotoxins and biology of Clostridium botulinum Group I and Group II

    PubMed Central

    Carter, Andrew T.; Peck, Michael W.

    2015-01-01

    Recent developments in whole genome sequencing have made a substantial contribution to understanding the genomes, neurotoxins and biology of Clostridium botulinum Group I (proteolytic C. botulinum) and C. botulinum Group II (non-proteolytic C. botulinum). Two different approaches are used to study genomics in these bacteria; comparative whole genome microarrays and direct comparison of complete genome DNA sequences. The properties of the different types of neurotoxin formed, and different neurotoxin gene clusters found in C. botulinum Groups I and II are explored. Specific examples of botulinum neurotoxin genes are chosen for an in-depth discussion of neurotoxin gene evolution. The most recent cases of foodborne botulism are summarised. PMID:25445012

  15. Maryland biological stream survey: Ecological assessment of non-tidal streams sampled in 1996

    SciTech Connect

    Roth, N.E.; Southerland, M.T.; Chaillou, J.C.; Wilson, W.T.; Heimbuch, D.G.

    1998-10-01

    The report summarizes results from the second of three years of sampling for the first round of the statewide Maryland Biological Stream Survey (MBSS or the Survey) and provides an update on the program`s progress in assessing the condition of Maryland`s non-tidal streams. Supported and led by the Maryland Department of Natural Resources (MDNR), the MBSS is a comprehensive program to assess the status of biological resources in Maryland`s non-tidal streams; quantify the extent to which acidic deposition has affected or may be affecting critical biological resources in the state; examine which other water chemistry, physical habitat, and land use factors are important in explaining the current status of biological resources in streams; establish a benchmark for long-term monitoring of trends in these resources; and target future local-scale assessments and mitigation measures needed to restore degraded biological resources.

  16. Correlation of mRNA and protein in complex biological samples.

    PubMed

    Maier, Tobias; Güell, Marc; Serrano, Luis

    2009-12-17

    The correlation between mRNA and protein abundances in the cell has been reported to be notoriously poor. Recent technological advances in the quantitative analysis of mRNA and protein species in complex samples allow the detailed analysis of this pathway at the center of biological systems. We give an overview of available methods for the identification and quantification of free and ribosome-bound mRNA, protein abundances and individual protein turnover rates. We review available literature on the correlation of mRNA and protein abundances and discuss biological and technical parameters influencing the correlation of these central biological molecules.

  17. On the accuracy of protein determination in large biological samples by prompt gamma neutron activation analysis

    NASA Astrophysics Data System (ADS)

    Kasviki, K.; Stamatelatos, I. E.; Yannakopoulou, E.; Papadopoulou, P.; Kalef-Ezra, J.

    2007-10-01

    A prompt gamma neutron activation analysis (PGNAA) facility has been developed for the determination of nitrogen and thus total protein in large volume biological samples or the whole body of small animals. In the present work, the accuracy of nitrogen determination by PGNAA in phantoms of known composition as well as in four raw ground meat samples of about 1 kg mass was examined. Dumas combustion and Kjeldahl techniques were also used for the assessment of nitrogen concentration in the meat samples. No statistically significant differences were found between the concentrations assessed by the three techniques. The results of this work demonstrate the applicability of PGNAA for the assessment of total protein in biological samples of 0.25-1.5 kg mass, such as a meat sample or the body of small animal even in vivo with an equivalent radiation dose of about 40 mSv.

  18. Schiff base triphenylphosphine palladium (II) complexes: Synthesis, structural elucidation, electrochemical and biological evaluation

    NASA Astrophysics Data System (ADS)

    Shabbir, Muhammad; Akhter, Zareen; Ahmad, Iqbal; Ahmed, Safeer; Shafiq, Maryam; Mirza, Bushra; McKee, Vickie; Munawar, Khurram Shahzad; Ashraf, Ahmad Raza

    2016-08-01

    The complexes N-(2-oxidophenyl)salicylideneiminatotriphenylphosphine palladium(II) (1) and N-(2-sulfidophenyl)salicylideneiminato triphenylphosphine palladium(II) (2) of tridentate Schiff bases derived from salicylaldehyde and an amino- or thiophenol, have been synthesized and characterized by various spectroscopic, analytical and electro-analytical techniques. X-ray single crystal analysis of complex 1 has revealed its square planar geometry. The thermal analysis has shown the absence of coordinated water and final degradation product is PdO. The alkaline phosphatase studies have indicated that enzymatic activity is concentration dependent which is inversely proportional to the concentration of the compounds. The biological assays (brine shrimp cytotoxicity, DPPH) have reflected their biologically active and mild antioxidant nature. However, results of DNA protection assay have shown that they possess moderate protective activity against hydroxyl free radicals (rad OH). The voltammetric studies ascertain two-electron reduction of the compounds through purely diffusion controlled process and reveal intercalative mode of drug DNA interactions.

  19. Design, spectral characterization and biological studies of transition metal(II) complexes with triazole Schiff bases

    NASA Astrophysics Data System (ADS)

    Hanif, Muhammad; Chohan, Zahid H.

    2013-03-01

    A new series of three biologically active triazole derived Schiff base ligands L1-L3 have been synthesized in equimolar reaction of 3-amino-1H-1,2,4-triazole with pyrrol-2-carboxaldehyde, 4-bromo-thiophene-2-carboxaldehyde, and 5-iodo-2-hydroxy benzaldehyde. The prepared Schiff bases were used for further complex formation reaction with different metal elements like Co(II), Ni(II), Cu(II) and Zn(II) as chlorides by using a molar ratio of ligand:metal as 2:1. The structure and bonding nature of all the compounds were identified by their physical, spectral and analytical data. All the metal(II) complexes possessed an octahedral geometry except the Cu(II) complexes which showed a distorted octahedral geometry. All the synthesized compounds, were studied for their in vitro antibacterial, and antifungal activities, against four Gram-negative (Escherichia coli, Shigella sonnei, Pseudomonas aeruginosa and Salmonella typhi) and two Gram-positive (Bacillus subtilis and Staphylococcus aureus) bacterial strains and against six fungal strains (Trichophyton longifusus, Candida albicans, Aspergillus flavus, Microsporum canis, Fusarium solani and Candida glabrata) by using agar-well diffusion method. It has been shown that all the synthesized compounds showed moderate to significant antibacterial activity against one or more bacterial strains. In vitro Brine Shrimp bioassay was also carried out to investigate the cytotoxic properties of these compounds. The data also revealed that the metal complexes showed better activity than the ligands due to chelation/coordination.

  20. Design, spectral characterization and biological studies of transition metal(II) complexes with triazole Schiff bases.

    PubMed

    Hanif, Muhammad; Chohan, Zahid H

    2013-03-01

    A new series of three biologically active triazole derived Schiff base ligands L(1)-L(3) have been synthesized in equimolar reaction of 3-amino-1H-1,2,4-triazole with pyrrol-2-carboxaldehyde, 4-bromo-thiophene-2-carboxaldehyde, and 5-iodo-2-hydroxy benzaldehyde. The prepared Schiff bases were used for further complex formation reaction with different metal elements like Co(II), Ni(II), Cu(II) and Zn(II) as chlorides by using a molar ratio of ligand:metal as 2:1. The structure and bonding nature of all the compounds were identified by their physical, spectral and analytical data. All the metal(II) complexes possessed an octahedral geometry except the Cu(II) complexes which showed a distorted octahedral geometry. All the synthesized compounds, were studied for their in vitro antibacterial, and antifungal activities, against four Gram-negative (Escherichia coli, Shigella sonnei, Pseudomonas aeruginosa and Salmonella typhi) and two Gram-positive (Bacillus subtilis and Staphylococcus aureus) bacterial strains and against six fungal strains (Trichophyton longifusus, Candida albicans, Aspergillus flavus, Microsporum canis, Fusarium solani and Candida glabrata) by using agar-well diffusion method. It has been shown that all the synthesized compounds showed moderate to significant antibacterial activity against one or more bacterial strains. In vitro Brine Shrimp bioassay was also carried out to investigate the cytotoxic properties of these compounds. The data also revealed that the metal complexes showed better activity than the ligands due to chelation/coordination. PMID:23277183

  1. Methods for collection and analysis of aquatic biological and microbiological samples

    USGS Publications Warehouse

    Greeson, Phillip E., (Edited By); Ehlke, T.A.; Irwin, G.A.; Lium, B.W.; Slack, K.V.

    1977-01-01

    Chapter A4 contains methods used by the U.S. Geological Survey to collect, preserve, and analyze waters to determine their biological and microbiological properties. Part 1 discusses biological sampling and sampling statistics. The statistical procedures are accompanied by examples. Part 2 consists of detailed descriptions of more than 45 individual methods, including those for bacteria, phytoplankton, zooplankton, seston, periphyton, macrophytes, benthic invertebrates, fish and other vertebrates, cellular contents, productivity, and bioassays. Each method is summarized, and the application, interferences, apparatus, reagents, collection, analysis, calculations, reporting of results, precision and references are given. Part 3 consists of a glossary. Part 4 is a list of taxonomic references.

  2. Views of female breast cancer patients who donated biologic samples regarding storage and use of samples for genetic research.

    PubMed

    Kaphingst, K A; Janoff, J M; Harris, L N; Emmons, K M

    2006-05-01

    Although social and ethical issues related to the storage and use of biologic specimens for genetic research have been discussed extensively in the medical literature, few empiric data exist describing patients' views. This qualitative study explored the views of 26 female breast cancer patients who had consented to donate blood or tissue samples for breast cancer research. Participants generally did not expect personal benefits from research and had few unprompted concerns. Few participants had concerns about use of samples for studies not planned at the time of consent. Some participants did express concerns about insurance or employment discrimination, while others believed that current privacy protections might actually slow breast cancer research. Participants were generally more interested in receiving individual genetic test results from research studies than aggregate results. Most participants did not want individual results of uncertain clinical significance, although others believed that they should be able to receive such information. These data examined the range of participants' views regarding the storage and use of biologic samples. Further research with different and diverse patient populations is critical to establishing an appropriate balance between protecting the rights of human subjects in genetic research and allowing research to progress.

  3. Spectroscopic analysis of bosentan in biological samples after a liquid-liquid microextraction

    PubMed Central

    Sajedi-Amin, Sanaz; Assadpour-Zeynali, Karim; Panahi-Azar, Vahid; Kebriaeezadeh, Abbas; Khoubnasabjafari, Maryam; Ansarin, Khalil; Jouyban-Gharamaleki, Vahid; Jouyban, Abolghasem

    2015-01-01

    Introduction:Microextraction processes with UV-Vis measurement have been developed and validated for analysis of bosentan in biological samples. Methods:In this work, liquid–liquid microextraction procedures (DLLME & USAEME) were employed for cleanup, pre-concentration, and determination of bosentan in biological samples by UV-Vis spectroscopy at 270 nm. The method was validated and applied to the determination of bosentan in spiked serum, exhaled breath condensate and urine samples. Results:Various experimental factors including type of extraction and dispersive solvents and their volumes, pH, sonication time and centrifuging time were investigated. Under the optimum conditions, the method was linear in the range of 1.0–5.0 μg.mL-1, with coefficient of determination (R2) of > 0.998. The limit of detection (LOD) was 0.07 mg.L-1. Recovery of the target analyte in biological samples was 106.2%. The method could be easily applied for higher concentration of bosentan and needs more improvement for application in the pharmacokinetic investigations where more sensitive methods are required. Conclusion:A simple, low cost, precise and accurate spectrophotometric analysis of bosentan in biological samples after liquid-liquid microextraction were developed and validated for routine analyses. PMID:26929923

  4. Simulation of a Congress at the Chair of Biology II in Bioengineering

    NASA Astrophysics Data System (ADS)

    Naranjo, A. V.; Reznichenco, V.; López, N.; Hernández, R.; Bajinay, S.

    2007-11-01

    This work has been developed in the Chair of Biology II, the curricular contents of which correspond to Human Anatomy. This subject is taught in the second semester of the second year of studies in Bioengineering. Our main objective is that the students attending the course may integrate the syllabus contents of Anatomy with those of other subjects in the career. Ever since 1998 we have organized a congress named Congreso Intracátedra de Biología II (Intra Chair Congress on Biology II). This is the last assignment in the semester and is compulsory for regular students of the subject. It consists in simulating a scientific congress with international characteristics. The guidelines for the congress are made known to the students at the beginning of the semester. In groups of up to three members, the students must undertake a work that relates aspects of Anatomy with Bioengineering. Students are expected to investigate on diagnostic and/or therapeutic technology in order to write a paper that must be accepted in advance of the event. The presentation of the work must be made through PowerPoint. The originality of the research work done and the wide range of topics selected are surprising. Problems are tackled from the standpoints both of the various medical fields and of bioengineering despite the fact that they are just students of the second year in Bioengineering.

  5. Imaging material properties of biological samples with a force feedback microscope.

    PubMed

    Costa, Luca; Rodrigues, Mario S; Newman, Emily; Zubieta, Chloe; Chevrier, Joёl; Comin, Fabio

    2013-12-01

    Mechanical properties of biological samples have been imaged with a force feedback microscope. Force, force gradient, and dissipation are measured simultaneously and quantitatively, merely knowing the atomic force microscopy cantilever spring constant. Our first results demonstrate that this robust method provides quantitative high resolution force measurements of the interaction. The small oscillation imposed on the cantilever and the small value of its stiffness result in vibrational energies much smaller than the thermal energy, reducing interaction with the sample to a minimum. We show that the observed mechanical properties of the sample depend on the force applied by the tip and consequently on the sample indentation.

  6. American Indian/Alaska Native Willingness to Provide Biological Samples for Research Purposes

    PubMed Central

    Young, Kristin L.; Nazir, Niaman; Williams, Chandler; Brown, Travis; Choi, Won S.; Greiner, K. A.; Daley, Christine M.

    2011-01-01

    This article examines the willingness of American Indian/Alaska Natives (AI/AN) to provide biological samples for research purposes. Prior cases of abuse and misuse of individuals, materials, and data highlight ethical research concerns. Investigators may be hesitant to engage AI/ANs in research projects. We conducted a survey of AI/ANs in the central plains region of the US over 1 year. This convenience sample completed a series of questions on biological samples and research. Survey results (N = 998) indicate that 70.15% of AI/ANs would be willing to provide saliva/spit for a specific study with the proper consent and control of samples. In conclusion, researchers should find ways to work with and for AI/ANs, assuring participant input in the research process. PMID:22057422

  7. Camels, Cormorants, and Kangaroo Rats: Integration and Synthesis in Organismal Biology After World War II.

    PubMed

    Hagen, Joel B

    2015-01-01

    During the decades following World War II diverse groups of American biologists established a variety of distinctive approaches to organismal biology. Rhetorically, organismal biology could be used defensively to distinguish established research traditions from perceived threats from newly emerging fields such as molecular biology. But, organismal biologists were also interested in integrating biological disciplines and using a focus on organisms to synthesize levels of organization from molecules and cells to populations and communities. Part of this broad movement was the development of an area of research variously referred to as physiological ecology, environmental physiology, or ecophysiology. This area of research was distinctive in its self-conscious blend of field and laboratory practices and its explicit integration with other areas of biology such as ecology, animal behavior, and evolution in order to study adaptation. Comparing the intersecting careers of Knut Schmidt-Nielsen and George Bartholomew highlights two strikingly different approaches to physiological ecology. These alternative approaches to studying the interactions of organisms and environments also differed in important ways from the organismal biology championed by leading figures in the modern synthesis.

  8. Tomographic imaging of transparent biological samples using the pyramid phase microscope.

    PubMed

    Iglesias, Ignacio

    2016-08-01

    We show how a pyramid phase microscope can be used to obtain tomographic information of the spatial variation of refractive index in biological samples using the Radon transform. A method that uses the information provided by the phase microscope for axial and lateral repositioning of the sample when it rotates is also described. Its application to the reconstruction of mouse embryos in the blastocyst stage is demonstrated.

  9. Tomographic imaging of transparent biological samples using the pyramid phase microscope.

    PubMed

    Iglesias, Ignacio

    2016-08-01

    We show how a pyramid phase microscope can be used to obtain tomographic information of the spatial variation of refractive index in biological samples using the Radon transform. A method that uses the information provided by the phase microscope for axial and lateral repositioning of the sample when it rotates is also described. Its application to the reconstruction of mouse embryos in the blastocyst stage is demonstrated. PMID:27570696

  10. Photothermal method using a pyroelectric sensor for thermophysical characterization of agricultural and biological samples

    NASA Astrophysics Data System (ADS)

    Frandas, A.; Dadarlat, Dorin; Chirtoc, Mihai; Jalink, Henk; Bicanic, Dane D.; Paris, D.; Antoniow, Jean S.; Egee, Michel; Ungureanu, Costica

    1998-07-01

    The photopyroelectric method in different experimental configurations was used for thermophysical characterization of agricultural and biological samples. The study appears important due to the relation of thermal parameters to the quality of foodstuffs (connected to their preservation, storage and adulteration), migration profiles in biodegradable packages, and the mechanism of desiccation tolerance of seeds. Results are presented on the thermal parameters measurement and their dependence on temperature and water content for samples such as: honey, starch, seeds.

  11. Tomographic imaging of transparent biological samples using the pyramid phase microscope

    PubMed Central

    Iglesias, Ignacio

    2016-01-01

    We show how a pyramid phase microscope can be used to obtain tomographic information of the spatial variation of refractive index in biological samples using the Radon transform. A method that uses the information provided by the phase microscope for axial and lateral repositioning of the sample when it rotates is also described. Its application to the reconstruction of mouse embryos in the blastocyst stage is demonstrated. PMID:27570696

  12. Probes for High Field Solid-state NMR of Lossy Biological Samples

    PubMed Central

    Grant, Christopher V.; Wu, Chin H.; Opella, Stanley J.

    2010-01-01

    In solid-state NMR exphydrated samples biopolymers are susceptible to radio-frequency heating and have a significant impact on probe tuning frequency and performance parameters such as sensitivity. These considerations are increasingly important as magnetic field strengths increase with improved magnet technology. Recent developments in the design, construction, and performance of probes for solid-state NMR experiments on stationary lossy biological samples at high magnetic fields are reviewed. PMID:20435493

  13. Method for the concentration and separation of actinides from biological and environmental samples

    DOEpatents

    Horwitz, E.P.; Dietz, M.L.

    1989-05-30

    A method and apparatus for the quantitative recover of actinide values from biological and environmental sample by passing appropriately prepared samples in a mineral acid solution through a separation column of a dialkyl(phenyl)-N,N-dialylcarbamoylmethylphosphine oxide dissolved in tri-n-butyl phosphate on an inert substrate which selectively extracts the actinide values. The actinide values can be eluted either as a group or individually and their presence quantitatively detected by alpha counting. 3 figs.

  14. Method for the concentration and separation of actinides from biological and environmental samples

    DOEpatents

    Horwitz, E. Philip; Dietz, Mark L.

    1989-01-01

    A method and apparatus for the quantitative recover of actinide values from biological and environmental sample by passing appropriately prepared samples in a mineral acid solution through a separation column of a dialkyl(phenyl)-N,N-dialylcarbamoylmethylphosphine oxide dissolved in tri-n-butyl phosphate on an inert substrate which selectively extracts the actinide values. The actinide values can be eluted either as a group or individually and their presence quantitatively detected by alpha counting.

  15. Optimization of dielectrophoretic separation and concentration of pathogens in complex biological samples

    NASA Astrophysics Data System (ADS)

    Bisceglia, E.; Cubizolles, M.; Mallard, F.; Pineda, F.; Francais, O.; Le Pioufle, B.

    2013-05-01

    Sample preparation is a key issue of modern analytical methods for in vitro diagnostics of diseases with microbiological origins: methods to separate bacteria from other elements of the complex biological samples are of great importance. In the present study, we investigated the DEP force as a way to perform such a de-complexification of the sample by extracting micro-organisms from a complex biological sample under a highly non-uniform electric field in a micro-system based on an interdigitated electrodes array. Different parameters were investigated to optimize the capture efficiency, such as the size of the gap between the electrodes and the height of the capture channel. These parameters are decisive for the distribution of the electric field inside the separation chamber. To optimize these relevant parameters, we performed numerical simulations using COMSOL Multiphysics and correlated them with experimental results. The optimization of the capture efficiency of the device has first been tested on micro-organisms solution but was also investigated on human blood samples spiked with micro-organisms, thereby mimicking real biological samples.

  16. MCT-based SWIR hyperspectral imaging system for evaluation of biological samples

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hyperspectral imaging has been shown to be a powerful tool for nondestructive evaluation of biological samples. We recently developed a new line-scan-based shortwave infrared (SWIR) hyperspectral imaging system. Critical sensing components of the system include a SWIR spectrograph, an MCT (HgCdTe) a...

  17. Current methods for detecting the presence of botulinum neurotoxins in food and other biological samples

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Current methods for detecting the presence of botulinum neurotoxins in food and other biological samples Botulinum neurotoxins (BoNTs), the causative agents of botulism, are among the most lethal human bacterial toxins and the causative agent of botulism. BoNTs are also classified as Select Agents ...

  18. Biological sample evaluation using a line-scan based SWIR hyperspectral imaging system

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A new line-scan hyperspectral imaging system was developed to enable short wavelength infrared (SWIR) imagery for biological sample evaluation. Critical sensing components include a SWIR imaging spectrograph and an HgCdTe (MCT) focal plane array detector. To date, agricultural applications of infra...

  19. Fast quantitative retardance imaging of biological samples using quadri-wave interferometry (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Aknoun, Sherazade; Bon, Pierre; Savatier, Julien; Monneret, Serge; Wattellier, Benoit F.

    2016-03-01

    We describe the use of polarized spatially coherent illumination to perform linear retardance imaging and measurements of semi-transparent biological samples using a quantitative phase imaging technique [1]. Quantitative phase imaging techniques [2-5] are used in microscopy for the imaging of semi-transparent samples and gives information about the optical path difference (OPD). The strength of those techniques is their non-invasive (the sample is not labelled) and fast approach. However, this high contrast is non-specific and cannot be linked to specific properties of the sample. To overcome this limitation, we propose to use polarized light in combination with QPI. Indeed, anisotropy has been used to reveal ordered fibrous structures in biological samples without any staining or labelling with polarized light microscopy [6-8]. Recent studies have shown polarimetry as a potential diagnostic tool for various dermatological diseases on thick tissue samples [9]. Particularly, specific collagen fibers spatial distribution has been demonstrated to be a signature for the optical diagnosis and prognosis of cancer in tissues [10]. In this paper, we describe a technical improvement of our technique based on high-resolution quadri-wave lateral shearing interferometry (QWLSI) and liquid crystal retarder to perform quantitative linear birefringence measurements on biological samples. The system combines a set of quantitative phase images with different excitation polarizations to create birefringence images. These give information about the local retardance and orientation of biological anisotropic components. We propose using a commercial QWLSI [11] (SID4Bio, Phasics SA, Saint Aubin, France) directly plugged onto a lateral video port of an inverted microscope (TE2000-U, Nikon, Japan). We are able to take retardance images in less than 1 second which allows us to record dynamic phenomena (living cells study) and make high speed acquisitions to reconstruct tissues virtual

  20. Zn(II)-coordination modulated ligand photophysical processes – the development of fluorescent indicators for imaging biological Zn(II) ions

    PubMed Central

    Yuan, Zhao; Simmons, J. Tyler; Sreenath, Kesavapillai

    2014-01-01

    Molecular photophysics and metal coordination chemistry are the two fundamental pillars that support the development of fluorescent cation indicators. In this article, we describe how Zn(II)-coordination alters various ligand-centered photophysical processes that are pertinent to developing Zn(II) indicators. The main aim is to show how small organic Zn(II) indicators work under the constraints of specific requirements, including Zn(II) detection range, photophysical requirements such as excitation energy and emission color, temporal and spatial resolutions in a heterogeneous intracellular environment, and fluorescence response selectivity between similar cations such as Zn(II) and Cd(II). In the last section, the biological questions that fluorescent Zn(II) indicators help to answer are described, which have been motivating and challenging this field of research. PMID:25071933

  1. Co(II) and Cd(II) Complexes Derived from Heterocyclic Schiff-Bases: Synthesis, Structural Characterisation, and Biological Activity

    PubMed Central

    Ahmed, Riyadh M.; Yousif, Enaam I.; Al-Jeboori, Mohamad J.

    2013-01-01

    New monomeric cobalt and cadmium complexes with Schiff-bases, namely, N′-[(E)-(3-hydroxy-4-methoxyphenyl)methylidene]furan-2-carbohydrazide (L1) and N′-[(E)-(3-hydroxy-4-methoxyphenyl)methylidene]thiophene-2-carbohydrazide (L2) are reported. Schiff-base ligands L1 and L2 were derived from condensation of 3-hydroxy-4-methoxybenzaldehyde (iso-vanillin) with furan-2-carboxylic acid hydrazide and thiophene-2-carboxylic acid hydrazide, respectively. Complexes of the general formula [M(L)2]Cl2 (where M = Co(II) or Cd(II), L = L1 or L2) have been obtained from the reaction of the corresponding metal chloride with the ligands. The ligands and their metal complexes were characterised by spectroscopic methods (FTIR, UV-Vis, 1H, and 13C NMR spectra), elemental analysis, metal content, magnetic measurement, and conductance. These studies revealed the formation of four-coordinate complexes in which the geometry about metal ion is tetrahedral. Biological activity of the ligands and their metal complexes against gram positive bacterial strain Bacillus (G+) and gram negative bacteria Pseudomonas (G−) revealed that the metal complexes become less resistive to the microbial activities as compared to the free ligands. PMID:24027449

  2. Optimal sample preparation conditions for the determination of uranium in biological samples by kinetic phosphorescence analysis (KPA).

    PubMed

    Ejnik, J W; Hamilton, M M; Adams, P R; Carmichael, A J

    2000-12-15

    Kinetic phosphorescence analysis (KPA) is a proven technique for rapid, precise, and accurate determination of uranium in aqueous solutions. Uranium analysis of biological samples require dry-ashing in a muffle furnace between 400 and 600 degrees C followed by wet-ashing with concentrated nitric acid and hydrogen peroxide to digest the organic component in the sample that interferes with uranium determination by KPA. The optimal dry-ashing temperature was determined to be 450 degrees C. At dry-ashing temperatures greater than 450 degrees C, uranium loss was attributed to vaporization. High temperatures also caused increased background values that were attributed to uranium leaching from the glass vials. Dry-ashing temperatures less than 450 degrees C result in the samples needing additional wet-ashing steps. The recovery of uranium in urine samples was 99.2+/-4.02% between spiked concentrations of 1.98-1980 ng (0.198-198 microg l(-1)) uranium, whereas the recovery in whole blood was 89.9+/-7.33% between the same spiked concentrations. The limit of quantification in which uranium in urine and blood could be accurately measured above the background was determined to be 0.05 and 0.6 microg l(-1), respectively. PMID:11130202

  3. The NYC native air sampling pilot project: using HVAC filter data for urban biological incident characterization.

    PubMed

    Ackelsberg, Joel; Leykam, Frederic M; Hazi, Yair; Madsen, Larry C; West, Todd H; Faltesek, Anthony; Henderson, Gavin D; Henderson, Christopher L; Leighton, Terrance

    2011-09-01

    Native air sampling (NAS) is distinguished from dedicated air sampling (DAS) devices (eg, BioWatch) that are deployed to detect aerosol disseminations of biological threat agents. NAS uses filter samples from heating, ventilation, and air conditioning (HVAC) systems in commercial properties for environmental sampling after DAS detection of biological threat agent incidents. It represents an untapped, scientifically sound, efficient, widely distributed, and comparably inexpensive resource for postevent environmental sampling. Calculations predict that postevent NAS would be more efficient than environmental surface sampling by orders of magnitude. HVAC filter samples could be collected from pre-identified surrounding NAS facilities to corroborate the DAS alarm and delineate the path taken by the bioaerosol plume. The New York City (NYC) Native Air Sampling Pilot Project explored whether native air sampling would be acceptable to private sector stakeholders and could be implemented successfully in NYC. Building trade associations facilitated outreach to and discussions with property owners and managers, who expedited contact with building managers of candidate NAS properties that they managed or owned. Nominal NAS building requirements were determined; procedures to identify and evaluate candidate NAS facilities were developed; data collection tools and other resources were designed and used to expedite candidate NAS building selection and evaluation in Manhattan; and exemplar environmental sampling playbooks for emergency responders were completed. In this sample, modern buildings with single or few corporate tenants were the best NAS candidate facilities. The Pilot Project successfully demonstrated that in one urban setting a native air sampling strategy could be implemented with effective public-private collaboration. PMID:21793731

  4. The NYC native air sampling pilot project: using HVAC filter data for urban biological incident characterization.

    PubMed

    Ackelsberg, Joel; Leykam, Frederic M; Hazi, Yair; Madsen, Larry C; West, Todd H; Faltesek, Anthony; Henderson, Gavin D; Henderson, Christopher L; Leighton, Terrance

    2011-09-01

    Native air sampling (NAS) is distinguished from dedicated air sampling (DAS) devices (eg, BioWatch) that are deployed to detect aerosol disseminations of biological threat agents. NAS uses filter samples from heating, ventilation, and air conditioning (HVAC) systems in commercial properties for environmental sampling after DAS detection of biological threat agent incidents. It represents an untapped, scientifically sound, efficient, widely distributed, and comparably inexpensive resource for postevent environmental sampling. Calculations predict that postevent NAS would be more efficient than environmental surface sampling by orders of magnitude. HVAC filter samples could be collected from pre-identified surrounding NAS facilities to corroborate the DAS alarm and delineate the path taken by the bioaerosol plume. The New York City (NYC) Native Air Sampling Pilot Project explored whether native air sampling would be acceptable to private sector stakeholders and could be implemented successfully in NYC. Building trade associations facilitated outreach to and discussions with property owners and managers, who expedited contact with building managers of candidate NAS properties that they managed or owned. Nominal NAS building requirements were determined; procedures to identify and evaluate candidate NAS facilities were developed; data collection tools and other resources were designed and used to expedite candidate NAS building selection and evaluation in Manhattan; and exemplar environmental sampling playbooks for emergency responders were completed. In this sample, modern buildings with single or few corporate tenants were the best NAS candidate facilities. The Pilot Project successfully demonstrated that in one urban setting a native air sampling strategy could be implemented with effective public-private collaboration.

  5. Effects of different temperature treatments on biological ice nuclei in snow samples

    NASA Astrophysics Data System (ADS)

    Hara, Kazutaka; Maki, Teruya; Kakikawa, Makiko; Kobayashi, Fumihisa; Matsuki, Atsushi

    2016-09-01

    The heat tolerance of biological ice nucleation activity (INA) depends on their types. Different temperature treatments may cause varying degrees of inactivation on biological ice nuclei (IN) in precipitation samples. In this study, we measured IN concentration and bacterial INA in snow samples using a drop freezing assay, and compared the results for unheated snow and snow treated at 40 °C and 90 °C. At a measured temperature of -7 °C, the concentration of IN in untreated snow was 100-570 L-1, whereas the concentration in snow treated at 40 °C and 90 °C was 31-270 L-1 and 2.5-14 L-1, respectively. In the present study, heat sensitive IN inactivated by heating at 40 °C were predominant, and ranged 23-78% of IN at -7 °C compared with untreated samples. Ice nucleation active Pseudomonas strains were also isolated from the snow samples, and heating at 40 °C and 90 °C inactivated these microorganisms. Consequently, different temperature treatments induced varying degrees of inactivation on IN in snow samples. Differences in the concentration of IN across a range of treatment temperatures might reflect the abundance of different heat sensitive biological IN components.

  6. Rapid methods to detect organic mercury and total selenium in biological samples

    PubMed Central

    2011-01-01

    Background Organic mercury (Hg) is a global pollutant of concern and selenium is believed to afford protection against mercury risk though few approaches exist to rapidly assess both chemicals in biological samples. Here, micro-scale and rapid methods to detect organic mercury (< 1.5 ml total sample volume, < 1.5 hour) and total selenium (Se; < 3.0 ml total volume, < 3 hour) from a range of biological samples (10-50 mg) are described. Results For organic Hg, samples are digested using Tris-HCl buffer (with sequential additions of protease, NaOH, cysteine, CuSO4, acidic NaBr) followed by extraction with toluene and Na2S2O3. The final product is analyzed via commercially available direct/total mercury analyzers. For Se, a fluorometric assay has been developed for microplate readers that involves digestion (HNO3-HClO4 and HCl), conjugation (2,3-diaminonaphthalene), and cyclohexane extraction. Recovery of organic Hg (86-107%) and Se (85-121%) were determined through use of Standard Reference Materials and lemon shark kidney tissues. Conclusions The approaches outlined provide an easy, rapid, reproducible, and cost-effective platform for monitoring organic Hg and total Se in biological samples. Owing to the importance of organic Hg and Se in the pathophysiology of Hg, integration of such methods into established research monitoring efforts (that largely focus on screening total Hg only) will help increase understanding of Hg's true risks. PMID:21232132

  7. Microfluidic solutions enabling continuous processing and monitoring of biological samples: A review.

    PubMed

    Karle, Marc; Vashist, Sandeep Kumar; Zengerle, Roland; von Stetten, Felix

    2016-07-27

    The last decade has witnessed tremendous advances in employing microfluidic solutions enabling Continuous Processing and Monitoring of Biological Samples (CPMBS), which is an essential requirement for the control of bio-processes. The microfluidic systems are superior to the traditional inline sensors due to their ability to implement complex analytical procedures, such as multi-step sample preparation, and enabling the online measurement of parameters. This manuscript provides a backgound review of microfluidic approaches employing laminar flow, hydrodynamic separation, acoustophoresis, electrophoresis, dielectrophoresis, magnetophoresis and segmented flow for the continuous processing and monitoring of biological samples. The principles, advantages and limitations of each microfluidic approach are described along with its potential applications. The challenges in the field and the future directions are also provided. PMID:27251944

  8. Toward greener analytical techniques for the absolute quantification of peptides in pharmaceutical and biological samples.

    PubMed

    Van Eeckhaut, Ann; Mangelings, Debby

    2015-09-10

    Peptide-based biopharmaceuticals represent one of the fastest growing classes of new drug molecules. New reaction types included in the synthesis strategies to reduce the rapid metabolism of peptides, along with the availability of new formulation and delivery technologies, resulted in an increased marketing of peptide drug products. In this regard, the development of analytical methods for quantification of peptides in pharmaceutical and biological samples is of utmost importance. From the sample preparation step to their analysis by means of chromatographic or electrophoretic methods, many difficulties should be tackled to analyze them. Recent developments in analytical techniques emphasize more and more on the use of green analytical techniques. This review will discuss the progresses in and challenges observed during green analytical method development for the quantification of peptides in pharmaceutical and biological samples. PMID:25864956

  9. Nanocharacterization of Soft Biological Samples in Shear Mode with Quartz Tuning Fork Probes

    PubMed Central

    Otero, Jorge; Gonzalez, Laura; Puig-Vidal, Manel

    2012-01-01

    Quartz tuning forks are extremely good resonators and their use is growing in scanning probe microscopy. Nevertheless, only a few studies on soft biological samples have been reported using these probes. In this work, we present the methodology to develop and use these nanosensors to properly work with biological samples. The working principles, fabrication and experimental setup are presented. The results in the nanocharacterization of different samples in different ambients are presented by using different working modes: amplitude modulation with and without the use of a Phase-Locked Loop (PLL) and frequency modulation. Pseudomonas aeruginosa bacteria are imaged in nitrogen using amplitude modulation. Microcontact printed antibodies are imaged in buffer using amplitude modulation with a PLL. Finally, metastatic cells are imaged in air using frequency modulation. PMID:22666059

  10. Toward greener analytical techniques for the absolute quantification of peptides in pharmaceutical and biological samples.

    PubMed

    Van Eeckhaut, Ann; Mangelings, Debby

    2015-09-10

    Peptide-based biopharmaceuticals represent one of the fastest growing classes of new drug molecules. New reaction types included in the synthesis strategies to reduce the rapid metabolism of peptides, along with the availability of new formulation and delivery technologies, resulted in an increased marketing of peptide drug products. In this regard, the development of analytical methods for quantification of peptides in pharmaceutical and biological samples is of utmost importance. From the sample preparation step to their analysis by means of chromatographic or electrophoretic methods, many difficulties should be tackled to analyze them. Recent developments in analytical techniques emphasize more and more on the use of green analytical techniques. This review will discuss the progresses in and challenges observed during green analytical method development for the quantification of peptides in pharmaceutical and biological samples.

  11. Swabs as DNA collection devices for sampling different biological materials from different substrates.

    PubMed

    Verdon, Timothy J; Mitchell, Robert J; van Oorschot, Roland A H

    2014-07-01

    Currently, there is a variety of swabs for collection of biological evidence from crime scenes, but their comparative efficiency is unknown. Here, we report the results of an investigation into the efficiency of different swab types to collect blood, saliva and touch DNA from a range of substrates. The efficiency of extracting blood and saliva from each swab type was also tested. Some swabs were significantly more effective than others for sampling biological materials from different substrates. Swabs with the highest sampling efficiency, however, often did not have the highest extraction efficiency. Observations were recorded regarding practicality of each swab in a variety of situations. Our study demonstrates that selection of sampling device impacts greatly upon successful collection and extraction of DNA. We present guidelines to assist in evaluation of swab choice. PMID:24502761

  12. Cloud point extraction and flame atomic absorption spectrometric determination of cadmium(II), lead(II), palladium(II) and silver(I) in environmental samples.

    PubMed

    Ghaedi, Mehrorang; Shokrollahi, Ardeshir; Niknam, Khodabakhsh; Niknam, Ebrahim; Najibi, Asma; Soylak, Mustafa

    2009-09-15

    The phase-separation phenomenon of non-ionic surfactants occurring in aqueous solution was used for the extraction of cadmium(II), lead(II), palladium(II) and silver(I). The analytical procedure involved the formation of understudy metals complex with bis((1H-benzo [d] imidazol-2yl)ethyl) sulfane (BIES), and quantitatively extracted to the phase rich in octylphenoxypolyethoxyethanol (Triton X-114) after centrifugation. Methanol acidified with 1molL(-1) HNO(3) was added to the surfactant-rich phase prior to its analysis by flame atomic absorption spectrometry (FAAS). The concentration of BIES, pH and amount of surfactant (Triton X-114) was optimized. At optimum conditions, the detection limits of (3 sdb/m) of 1.4, 2.8, 1.6 and 1.4 ng mL(-1) for Cd(2+), Pb(2+), Pd(2+) and Ag(+) along with preconcentration factors of 30 and enrichment factors of 48, 39, 32 and 42 for Cd(2+), Pb(2+), Pd(2+) and Ag(+), respectively, were obtained. The proposed cloud point extraction has been successfully applied for the determination of metal ions in real samples with complicated matrix such as radiology waste, vegetable, blood and urine samples. PMID:19380196

  13. Direct observation of unstained wet biological samples by scanning-electron generation X-ray microscopy.

    PubMed

    Ogura, Toshihiko

    2010-01-01

    Analytical tools of nanometre-scale resolution are indispensable in the fields of biology, physics and chemistry. One suitable tool, the soft X-ray microscope, provides high spatial resolution of visible light for wet specimens. For biological specimens, X-rays of water-window wavelength between carbon (284 eV; 4.3 nm) and oxygen (540 eV; 2.3 nm) absorption edges provide high-contrast imaging of biological samples in water. Among types of X-ray microscope, the transmission X-ray microscope using a synchrotron radiation source with diffractive zone plates offers the highest spatial resolution, approaching 15-10nm. However, even higher resolution is required to measure proteins and protein complexes in biological specimens; therefore, a new type of X-ray microscope with higher resolution that uses a simple light source is desirable. Here we report a novel scanning-electron generation X-ray microscope (SGXM) that demonstrates direct imaging of unstained wet biological specimens. We deposited wet yeasts in the space between two silicon nitride (Si(3)N(4)) films. A scanning electron beam of accelerating voltage 5 keV and current 1.6 nA irradiates the titanium (Ti)-coated Si(3)N(4) film, and the soft X-ray signal from it is detected by an X-ray photodiode (PD) placed below the sample. The SGXM can theoretically achieve better than 5 nm resolution. Our method can be utilized easily for various wet biological samples of bacteria, viruses, and protein complexes.

  14. Biological sample collections from minors for genetic research: a systematic review of guidelines and position papers

    PubMed Central

    Hens, Kristien; Nys, Herman; Cassiman, Jean-Jacques; Dierickx, Kris

    2009-01-01

    Stored tissue samples are an important resource for epidemiological genetic research. Genetic research on biological material from minors can yield valuable information on the development and genesis of early-onset genetic disorders and the early interaction of environmental and genetic factors. The use of such tissue raises some specific ethical and governance questions, which are not completely covered by the discussion on biological materials from adults. We have retrieved 29 guidelines and position papers pertaining to the storage and use of biological tissue samples for genetic research, originating from 27 different organizations. Five documents have an international scope, three have an European scope and 21 have a national scope. We discovered that 11 of these documents did not contain a section on biological materials from minors. The content of the remaining 18 documents was categorized according to four themes: consent, principles of non-therapeutic research on vulnerable populations, ethics committee approval and difference between anonymous and identifiable samples. We found out that these themes are not consistently mentioned by each document, but that documents discussing the same themes were mostly in agreement with their recommendations. However, a systematic reflection on the ethical and policy issues arising from the participation of minors in biobank research is missing. PMID:19223929

  15. Inductively coupled plasma mass spectrometry in the analysis of biological samples and pharmaceutical drugs

    NASA Astrophysics Data System (ADS)

    Ossipov, K.; Seregina, I. F.; Bolshov, M. A.

    2016-04-01

    Inductively coupled plasma mass spectrometry (ICP-MS) is widely used in the analysis of biological samples (whole blood, serum, blood plasma, urine, tissues, etc.) and pharmaceutical drugs. The shortcomings of this method related to spectral and non-spectral interferences are manifested in full measure in determination of the target analytes in these complex samples strongly differing in composition. The spectral interferences are caused by similarity of masses of the target component and sample matrix components. Non-spectral interferences are related to the influence of sample matrix components on the physicochemical processes taking place during formation and transportation of liquid sample aerosols into the plasma, on the value and spatial distribution of plasma temperature and on the transmission of the ion beam from the interface to mass spectrometer detector. The review is devoted to analysis of different mechanisms of appearance of non-spectral interferences and to ways for their minimization or elimination. Special attention is paid to the techniques of biological sample preparation, which largely determine the mechanisms of the influence of sample composition on the results of element determination. The ways of lowering non-spectral interferences by instrumental parameter tuning and application of internal standards are considered. The bibliography includes 189 references.

  16. Specific absorption rate in electrically coupled biological samples between metal plates.

    PubMed

    Joines, W T; Blackman, C F; Spiegel, R J

    1986-01-01

    The specific absorption rate (SAR) in a biological sample irradiated by electromagnetic fields between the metal plates of a transmission line can be altered significantly by the spacing of the metal plates and the distance between neighboring samples. The SAR in spherical biological samples is calculated for a number of neighboring sample arrangements and metal-plate spacings by using the method of images and induced dipole coupling. For a decrease in metal-plate spacing, the derived equations predict an increase in SAR within a sample and a decrease in SAR with a decrease in neighboring-sample spacing. The calculations are compared with measurements made with the aid of an array of 1-in radius metal hemispheres on the lower plate of two parallel plates (thus forming an image system). The hemisphere on which measurements are taken is insulated from the metal plate and is connected via a coaxial center conductor to an HP 3582A spectrum analyzer that measures the voltage and hence the electric field intensity at the hemisphere. Measurements made at a frequency where wavelength is large compared with sample size (48 Hz) are in good agreement with calculations. PMID:3741491

  17. Solid Phase Microextraction and Related Techniques for Drugs in Biological Samples

    PubMed Central

    Moein, Mohammad Mahdi; Said, Rana; Bassyouni, Fatma

    2014-01-01

    In drug discovery and development, the quantification of drugs in biological samples is an important task for the determination of the physiological performance of the investigated drugs. After sampling, the next step in the analytical process is sample preparation. Because of the low concentration levels of drug in plasma and the variety of the metabolites, the selected extraction technique should be virtually exhaustive. Recent developments of sample handling techniques are directed, from one side, toward automatization and online coupling of sample preparation units. The primary objective of this review is to present the recent developments in microextraction sample preparation methods for analysis of drugs in biological fluids. Microextraction techniques allow for less consumption of solvent, reagents, and packing materials, and small sample volumes can be used. In this review the use of solid phase microextraction (SPME), microextraction in packed sorbent (MEPS), and stir-bar sorbtive extraction (SBSE) in drug analysis will be discussed. In addition, the use of new sorbents such as monoliths and molecularly imprinted polymers will be presented. PMID:24688797

  18. A supplement to "Methods for collection and analysis of aquatic biological and microbiological samples"

    USGS Publications Warehouse

    1979-01-01

    The report contains methods used by the U.S. Geological Survey to collect, preserve, and analyze waters to determine their biological and microbiological properties. It supplements, "Methods for Collection and Analysis of Aquatic Biological and Microbiological Samples" (TWRI, Book 5, Chapter A4, 1977, edited by P. E. Greeson, T. A. Ehlke, G. A. Irwin, B. W. Lium, and K. V. Slack). Included in the supplement are 5 new methods, a new section of selected taxonomic references for Ostracoda, and 6 revised methods.

  19. Creating internal conductivity in dry biological SEM samples by a simple vapour treatment.

    PubMed

    Ensikat, H-J; Weigend, M

    2014-12-01

    Internal sample conductivity in scanning electron microscopy can be a valuable alternative to metal coating. Proton conductivity may be used for this purpose. Many solid materials with active hydrogen atoms, such as hydrogen- and ammonium-salts, organic acids, and even ice, are protonic conductors or semiconductors. Here we present a method to generate proton conductivity in dry biological materials. A simple treatment with hydrogen chloride gas or hydrochloric acid vapour for a few minutes provides sufficient conductivity for many samples. After a removal of excess hydrogen chloride vapour with a vacuum desiccator, the objects may be examined in the SEM without metal coating. The use of internally conductive samples extends the range of easy-to-perform SEM preparation techniques. It is advantageous for material contrast imaging of uncoated samples, and it can be used in combination with metal coating to enhance conductivity on difficult samples with complex overlapping surfaces, where simple metal coating does not reliably eliminate charging problems. PMID:25204567

  20. Biological sampling methods and effects of exposure to municipal and chemical landfill leachate on aquatic organisms

    SciTech Connect

    Janisz, A.J.; Butterfield, W.S.

    1983-03-01

    Extensive biological sampling on five abandoned hazardous waste sites in New York, New Jersey, and Puerto Rico was undertaken during 1981 and 1982 to determine the impact of priority pollutants on aquatic fauna and, potentially, on human health. The selection criteria for sites, sampling equipment, problems in personnel protection, and sample handling procedures are presented. The effects of the hazardous waste sites were assessed using a wide range of fish and invertebrate species. Tissue specimens from eleven vertebrate and eight invertebrate species were analyzed. Forty samples of these tissue specimens were analyzed for all inorganic priority pollutant parameters; an additional 35 samples were analyzed for organic priority pollutants or an appropriate subset of them. High concentrations of polychlorinated biphenyls (PCBs) were found in aquatic organisms exposed to chemical landfill leachate; the results of the tissue analyses at other sites were negative.

  1. Hyperspectral imaging of nanoparticles in biological samples: Simultaneous visualization and elemental identification.

    PubMed

    Peña, María Del Pilar Sosa; Gottipati, Abhishek; Tahiliani, Sahil; Neu-Baker, Nicole M; Frame, Mary D; Friedman, Adam J; Brenner, Sara A

    2016-05-01

    While engineered nanomaterials (ENMs) are increasingly incorporated into industrial processes and consumer products, the potential biological effects and health outcomes of exposure remain unknown. Novel advanced direct visualization techniques that require less time, cost, and resource investment than electron microscopy (EM) are needed for identifying and locating ENMs in biological samples. Hyperspectral imaging (HSI) combines spectrophotometry and imaging, using advanced optics and algorithms to capture a spectrum from 400 to 1000 nm at each pixel in an enhanced dark-field microscopic (EDFM) image. HSI-EDFM can be used to confirm the identity of the materials of interest in a sample and generate an image "mapping" their presence and location in a sample. Hyperspectral mapping is particularly important for biological samples, where ENM morphology is visually indistinct from surrounding tissue structures. While use of HSI (without mapping) is increasing, no studies to date have compared results from hyperspectral mapping with conventional methods. Thus, the objective of this study was to utilize EDFM-HSI to locate, identify, and map metal oxide ENMs in ex vivo histological porcine skin tissues, a toxicological model of cutaneous exposure, and compare findings with those of Raman spectroscopy (RS), energy-dispersive X-ray spectroscopy (EDS), and scanning electron microscopy (SEM). Results demonstrate that EDFM-HSI mapping is capable of locating and identifying ENMs in tissue, as confirmed by conventional methods. This study serves as initial confirmation of EDFM-HSI mapping as a novel and higher throughput technique for ENM identification in biological samples, and serves as the basis for further protocol development utilizing EDFM-HSI for semiquantitation of ENMs. PMID:26864497

  2. Characterization and biological activities of two copper(II) complexes with dipropylenetriamine and diamine as ligands

    NASA Astrophysics Data System (ADS)

    AL-Noaimi, Mousa; Choudhary, Mohammad I.; Awwadi, Firas F.; Talib, Wamidh H.; Hadda, Taibi Ben; Yousuf, Sammer; Sawafta, Ashraf; Warad, Ismail

    2014-06-01

    Two new mixed-ligand copper(II) complexes, [Cu(dipn)(Nsbnd N)]Br2(1-2) [dipn = dipropylenetriamine, Nsbnd N = ethylenediamine (en) (1) and propylenediamine (pn) (2)], have been synthesized. These complexes were characterized by spectroscopic and thermal techniques. Crystal structure for 2 shows a distorted trigonal-bipyramidal geometry around Cu(II) ion with one solvate water molecule. Antimicrobial and antiproliferative assays were conducted to evaluate the biological activities of these complexes. The complexes exhibit a promising antimicrobial effect against an array of microbes at 200 μg/mL concentration. The antiproliferative assay shows a high potential of these complexes to target Human keratinocyte cell line with IC50 values of 155 and 152 μM. The absorption spectrum of 2 in water was modeled by time-dependent density functional theory (TD-DFT).

  3. Presence of Atrazine in the Biological Samples of Cattle and Its Consequence Adversity in Human Health

    PubMed Central

    Peighambarzadeh, SZ; Safi, S; Shahtaheri, SJ; Javanbakht, M; Rahimi Forushani, A

    2011-01-01

    Background Cattle can be considered as an important source for herbicides through nutrition. Therefore, herbicide residue in animal products is a potential human exposure to herbicides causing public health problems in human life. Triazines are a group of herbicides primarily used to control broadleaf weeds in corn and other feed ingredients and are considered as possible human carcinogens. To evaluate trace residue of these pollutants molecular imprinted solid phase extraction (MISPE) method has been developed, using biological samples. Methods: Blood samples were taken from the jugular vein of 45 Holstein cows in 3 commercial dairy farms in Khuzestan Province, Iran. Urine samples were also taken from the cows. Results: The mean ± SD concentrations of atrazine in serum and urine samples of the study group (0.739 ± 0.567 ppm and 1.389 ± 0.633 ppm, respectively) were higher (P < 0.05) than the concentrations in serum and urine samples of the control group (0.002 ± 0.005 ppm and 0.012 ± 0.026 ppm, respectively). Conclusion: Atrazine in the feed ingredients ingested by cattle could be transferred into the biological samples and consequently can be considered as a potential hazard for the public health. PMID:23113110

  4. Elemental and isotopic imaging of biological samples using NanoSIMS.

    PubMed

    Kilburn, Matt R; Clode, Peta L

    2014-01-01

    With its low detection limits and the ability to analyze most of the elements in the periodic table, secondary ion mass spectrometry (SIMS) represents one of the most versatile in situ analytical techniques available, and recent developments have resulted in significant advantages for the use of imaging mass spectrometry in biological and biomedical research. Increases in spatial resolution and sensitivity allow detailed interrogation of samples at relevant scales and chemical concentrations. Advances in dynamic SIMS, specifically with the advent of NanoSIMS, now allow the tracking of stable isotopes within biological systems at subcellular length scales, while static SIMS combines subcellular imaging with molecular identification. In this chapter, we present an introduction to the SIMS technique, with particular reference to NanoSIMS, and discuss its application in biological and biomedical research.

  5. Elemental and isotopic imaging of biological samples using NanoSIMS.

    PubMed

    Kilburn, Matt R; Clode, Peta L

    2014-01-01

    With its low detection limits and the ability to analyze most of the elements in the periodic table, secondary ion mass spectrometry (SIMS) represents one of the most versatile in situ analytical techniques available, and recent developments have resulted in significant advantages for the use of imaging mass spectrometry in biological and biomedical research. Increases in spatial resolution and sensitivity allow detailed interrogation of samples at relevant scales and chemical concentrations. Advances in dynamic SIMS, specifically with the advent of NanoSIMS, now allow the tracking of stable isotopes within biological systems at subcellular length scales, while static SIMS combines subcellular imaging with molecular identification. In this chapter, we present an introduction to the SIMS technique, with particular reference to NanoSIMS, and discuss its application in biological and biomedical research. PMID:24357388

  6. Improved cosmological constraints from a joint analysis of the SDSS-II and SNLS supernova samples

    NASA Astrophysics Data System (ADS)

    Betoule, M.; Kessler, R.; Guy, J.; Mosher, J.; Hardin, D.; Biswas, R.; Astier, P.; El-Hage, P.; Konig, M.; Kuhlmann, S.; Marriner, J.; Pain, R.; Regnault, N.; Balland, C.; Bassett, B. A.; Brown, P. J.; Campbell, H.; Carlberg, R. G.; Cellier-Holzem, F.; Cinabro, D.; Conley, A.; D'Andrea, C. B.; DePoy, D. L.; Doi, M.; Ellis, R. S.; Fabbro, S.; Filippenko, A. V.; Foley, R. J.; Frieman, J. A.; Fouchez, D.; Galbany, L.; Goobar, A.; Gupta, R. R.; Hill, G. J.; Hlozek, R.; Hogan, C. J.; Hook, I. M.; Howell, D. A.; Jha, S. W.; Le Guillou, L.; Leloudas, G.; Lidman, C.; Marshall, J. L.; Möller, A.; Mourão, A. M.; Neveu, J.; Nichol, R.; Olmstead, M. D.; Palanque-Delabrouille, N.; Perlmutter, S.; Prieto, J. L.; Pritchet, C. J.; Richmond, M.; Riess, A. G.; Ruhlmann-Kleider, V.; Sako, M.; Schahmaneche, K.; Schneider, D. P.; Smith, M.; Sollerman, J.; Sullivan, M.; Walton, N. A.; Wheeler, C. J.

    2014-08-01

    Aims: We present cosmological constraints from a joint analysis of type Ia supernova (SN Ia) observations obtained by the SDSS-II and SNLS collaborations. The dataset includes several low-redshift samples (z< 0.1), all three seasons from the SDSS-II (0.05 II spectroscopically-confirmed SN Ia sample in both the training of the SALT2 light-curve model and in the Hubble diagram analysis (374 SNe); 2) intercalibration of the SNLS and SDSS surveys and reduced systematic uncertainties in the photometric calibration, performed blindly with respect to the cosmology analysis; and 3) a thorough investigation of systematic errors associated with the SALT2 modeling of SN Ia light curves. Results: We produce recalibrated SN Ia light curves and associated distances for the SDSS-II and SNLS samples. The large SDSS-II sample provides an effective, independent, low-z anchor for the Hubble diagram and reduces the systematic error from calibration systematics in the low-z SN sample. For a flat ΛCDM cosmology, we find Ωm =0.295 ± 0.034 (stat+sys), a value consistent with the most recent cosmic microwave background (CMB) measurement from the Planck and WMAP experiments. Our result is 1.8σ (stat+sys) different than the previously published result of SNLS three-year data. The change is due primarily to improvements in the SNLS photometric calibration. When combined with CMB constraints, we measure a constant dark-energy equation of state parameter w =-1.018 ± 0.057 (stat+sys) for a flat universe. Adding baryon acoustic oscillation distance measurements gives similar constraints: w =-1.027 ± 0.055. Our supernova measurements provide the most stringent constraints to date on

  7. Derivatization of steroids in biological samples for GC-MS and LC-MS analyses.

    PubMed

    Marcos, Josep; Pozo, Oscar J

    2015-10-01

    The determination of steroids in biological samples is essential in different areas of knowledge. MS combined with either GC or LC is considered the best analytical technique for specific and sensitive determinations. However, due to the physicochemical properties of some steroids, and the low concentrations found in biological samples, the formation of a derivative prior to their analysis is required. In GC-MS determinations, derivatization is needed for generating volatile and thermally stable compounds. The improvement in terms of stability and chromatographic retention are the main reasons for selecting the derivatization agent. On the other hand, derivatization is not compulsory in LC-MS analyses and the derivatization is typically used for improving the ionization and therefore the overall sensitivity achieved.

  8. Microwave acid digestion and preconcentration neutron activation analysis of biological and diet samples for iodine.

    PubMed

    Rao, R R; Chatt, A

    1991-07-01

    A simple preconcentration neutron activation analysis (PNAA) method has been developed for the determination of low levels of iodine in biological and nutritional materials. The method involves dissolution of the samples by microwave digestion in the presence of acids in closed Teflon bombs and preconcentration of total iodine, after reduction to iodide with hydrazine sulfate, by coprecipitation with bismuth sulfide. The effects of different factors such as acidity, time for complete precipitation, and concentrations of bismuth, sulfide, and diverse ions on the quantitative recovery of iodide have been studied. The absolute detection limit of the PNAA method is 5 ng of iodine. Precision of measurement, expressed in terms of relative standard deviation, is about 5% at 100 ppb and 10% at 20 ppb levels of iodine. The PNAA method has been applied to several biological reference materials and total diet samples. PMID:1897721

  9. Recent advances in salt-assisted LLE for analyzing biological samples.

    PubMed

    Valente, Inês Maria; Rodrigues, José António

    2015-01-01

    Salt-assisted LLE (SALLE) has been attracting growing interest in bioanalysis. The technique is particularly advantageous due to its simple and fast experimental execution using conventional laboratory equipment. Besides, SALLE uses water-miscible organic solvents making the extracts readily compatible with various analytical separation and detection techniques. This article presents a brief overview of the extraction technique and its role in bioanalysis. Some of the most relevant achievements on SALLE application to biological samples are discussed - namely the study of the main extraction parameters, the combination with other extraction techniques and the instrumental analysis of the extracts. Developments on automation, miniaturization and microextraction for SALLE procedures are also discussed as a perspective for future applications even more attractive for the analysis of biological samples.

  10. Axial-scanning low-coherence interferometer method for noncontact thickness measurement of biological samples

    SciTech Connect

    Kim, Do-Hyun; Song, Chul-Gyu; Ilev, Ilko K.; Kang, Jin U.

    2011-02-20

    We investigated a high-precision optical method for measuring the thickness of biological samples regardless of their transparency. The method is based on the precise measurement of optical path length difference of the end surfaces of objects, using a dual-arm axial-scanning low-coherence interferometer. This removes any consideration of the shape, thickness, or transparency of testing objects when performing the measurement. Scanning the reference simplifies the measurement setup, resulting in unambiguous measurement. Using a 1310 nm wavelength superluminescent diode, with a 65 nm bandwidth, the measurement accuracy was as high as 11.6 {mu}m. We tested the method by measuring the thickness of both transparent samples and nontransparent soft biological tissues.

  11. Microwave acid digestion and preconcentration neutron activation analysis of biological and diet samples for iodine.

    PubMed

    Rao, R R; Chatt, A

    1991-07-01

    A simple preconcentration neutron activation analysis (PNAA) method has been developed for the determination of low levels of iodine in biological and nutritional materials. The method involves dissolution of the samples by microwave digestion in the presence of acids in closed Teflon bombs and preconcentration of total iodine, after reduction to iodide with hydrazine sulfate, by coprecipitation with bismuth sulfide. The effects of different factors such as acidity, time for complete precipitation, and concentrations of bismuth, sulfide, and diverse ions on the quantitative recovery of iodide have been studied. The absolute detection limit of the PNAA method is 5 ng of iodine. Precision of measurement, expressed in terms of relative standard deviation, is about 5% at 100 ppb and 10% at 20 ppb levels of iodine. The PNAA method has been applied to several biological reference materials and total diet samples.

  12. Applications of PIXE to biological and biomedical samples at the university of gent

    NASA Astrophysics Data System (ADS)

    Maenhaut, W.; Vandenhaute, J.; Duflou, H.; De Reuck, J.

    1987-03-01

    The research on biological and biomedical samples, conducted at the University of Gent during the last 4-5 years and using PIXE as analytical technique, is presented. Our optimized sample/target preparation methods are described, and the accuracy and precision obtainable with them are discussed. Two comprehensive biological/biomedical research projects, initiated at Gent, are presented. The first aims at investigating possible trace element changes in tissues of experimental animals (rats) as a result of liver necrosis or cirrhosis, induced by intraperitoneal injection with CCl 4. The second project involves the determination of the regional distribution of trace elements in the human brain. Eight elements, i.e. K, Ca, Mn, Fe, Cu, Zn, Se and Rb, are being measured in up to 50 different regions of 12 normal brains, and in selected brain regions from patients with neurological disorders. Some of the results of the two projects are discussed.

  13. A Rapid and Specific Method for the Detection of Indole in Complex Biological Samples

    PubMed Central

    Chappell, Cynthia; Gonzales, Christopher; Okhuysen, Pablo

    2015-01-01

    Indole, a bacterial product of tryptophan degradation, has a variety of important applications in the pharmaceutical industry and is a biomarker in biological and clinical specimens. Yet, specific assays to quantitate indole are complex and require expensive equipment and a high level of training. Thus, indole in biological samples is often estimated using the simple and rapid Kovács assay, which nonspecifically detects a variety of commonly occurring indole analogs. We demonstrate here a sensitive, specific, and rapid method for measuring indole in complex biological samples using a specific reaction between unsubstituted indole and hydroxylamine. We compared the hydroxylamine-based indole assay (HIA) to the Kovács assay and confirmed that the two assays are capable of detecting microgram amounts of indole. However, the HIA is specific to indole and does not detect other naturally occurring indole analogs. We further demonstrated the utility of the HIA in measuring indole levels in clinically relevant biological materials, such as fecal samples and bacterial cultures. Mean and median fecal indole concentrations from 53 healthy adults were 2.59 mM and 2.73 mM, respectively, but varied widely (0.30 mM to 6.64 mM) among individuals. We also determined that enterotoxigenic Escherichia coli strain H10407 produces 3.3 ± 0.22 mM indole during a 24-h period in the presence of 5 mM tryptophan. The sensitive and specific HIA should be of value in a variety of settings, such as the evaluation of various clinical samples and the study of indole-producing bacterial species in the gut microbiota. PMID:26386049

  14. Comparison of various dissolution techniques for determination of Po-210 in biological samples.

    PubMed

    Planinšek, P; Benedik, L; Smodiš, B

    2013-11-01

    The aim of the present study was to compare three wet digestion procedures for dissolution of biological samples in the determination of Po-210. Classical wet ashing over a gas flame with acids in a long-necked Kjeldahl flask, digestion with acids in an Erlenmeyer flask and microwave digestion in a Teflon vessel at temperatures at up to 200°C were investigated. The results obtained showed that the activity concentrations of Po-210 found in the samples analysed were comparable for all the procedures used.

  15. New hybrid materials as Zn(II) sorbents in water samples

    SciTech Connect

    Perez-Quintanilla, Damian

    2010-09-15

    Mesoporous silicas have been chemically modified with 5-mercapto-1-methyltetrazole (MTTZ) obtaining hybrid materials denominated MTTZ-MSU-2 and MTTZ-HMS. These materials were employed as Zn(II) sorbents from aqueous media at room temperature. The effect of several variables (stirring time, pH, presence of other metals) has been studied using batch and column techniques. Flame atomic absorption spectrometry (FAAS) was used to determinate Zn(II) concentration in the filtrate or in the eluted solution after the adsorption process. The results indicate that under pH 8, the maximum adsorption value was 0.94 {+-} 0.01 and 0.72 {+-} 0.01 mmol Zn(II)/g for MTTZ-MSU-2 and MTTZ-HMS, respectively. In tap water samples, a preconcentration factor of 200 was obtained. On the basis of these results, it can be concluded that it is possible to modify chemically MSU-2 and HMS with 5-mercapto-1-methyltetrazole and to use the resulting modified mesoporous silica as an effective adsorbent for Zn(II) in aqueous media.

  16. Assessment of the differential linear coherent scattering coefficient of biological samples

    NASA Astrophysics Data System (ADS)

    Conceição, A. L. C.; Antoniassi, M.; Poletti, M. E.

    2010-07-01

    New differential linear coherent scattering coefficient, μ CS, data for four biological tissue types (fat pork, tendon chicken, adipose and fibroglandular human breast tissues) covering a large momentum transfer interval (0.07≤ q≤70.5 nm -1), resulted from combining WAXS and SAXS data, are presented in order to emphasize the need to update the default data-base by including the molecular interference and the large-scale arrangements effect. The results showed that the differential linear coherent scattering coefficient demonstrates influence of the large-scale arrangement, mainly due to collagen fibrils for tendon chicken and fibroglandular breast samples, and triacylglycerides for fat pork and adipose breast samples at low momentum transfer region. While, at high momentum transfer, the μ CS reflects effects of molecular interference related to water for tendon chicken and fibroglandular samples and, fatty acids for fat pork and adipose samples.

  17. Comparison of 2 modifications of the twin-block appliance in matched Class II samples.

    PubMed

    Parkin, N A; McKeown, H F; Sandler, P J

    2001-06-01

    The purpose of this study was to compare the skeletal and dental changes contributing to Class II correction with 2 modifications of the Twin-block appliance: Twin-block appliances that use a labial bow (TB1) and Twin-block appliances that incorporate high-pull headgear and torquing spurs on the maxillary central incisors (TB2). After pretreatment equivalence was established, a total of 36 consecutively treated patients with the TB1 modification were compared with 27 patients treated with the TB2 modification. Both samples were treated in the same hospital department and the same technician made all the appliances. The cephalostat, digitizing package, and statistical methods were common to both groups. The results demonstrated that the addition of headgear to the appliance resulted in effective vertical and sagittal control of the maxillary complex and thus maximized the Class II skeletal correction in the TB2 sample. Use of the torquing springs resulted in less retroclination of the maxillary incisors in the TB2 sample when compared with the TB1 sample; however, this difference did not reach the level of statistical significance.

  18. Sampling designs matching species biology produce accurate and affordable abundance indices

    PubMed Central

    Farley, Sean; Russell, Gareth J.; Butler, Matthew J.; Selinger, Jeff

    2013-01-01

    Wildlife biologists often use grid-based designs to sample animals and generate abundance estimates. Although sampling in grids is theoretically sound, in application, the method can be logistically difficult and expensive when sampling elusive species inhabiting extensive areas. These factors make it challenging to sample animals and meet the statistical assumption of all individuals having an equal probability of capture. Violating this assumption biases results. Does an alternative exist? Perhaps by sampling only where resources attract animals (i.e., targeted sampling), it would provide accurate abundance estimates more efficiently and affordably. However, biases from this approach would also arise if individuals have an unequal probability of capture, especially if some failed to visit the sampling area. Since most biological programs are resource limited, and acquiring abundance data drives many conservation and management applications, it becomes imperative to identify economical and informative sampling designs. Therefore, we evaluated abundance estimates generated from grid and targeted sampling designs using simulations based on geographic positioning system (GPS) data from 42 Alaskan brown bears (Ursus arctos). Migratory salmon drew brown bears from the wider landscape, concentrating them at anadromous streams. This provided a scenario for testing the targeted approach. Grid and targeted sampling varied by trap amount, location (traps placed randomly, systematically or by expert opinion), and traps stationary or moved between capture sessions. We began by identifying when to sample, and if bears had equal probability of capture. We compared abundance estimates against seven criteria: bias, precision, accuracy, effort, plus encounter rates, and probabilities of capture and recapture. One grid (49 km2 cells) and one targeted configuration provided the most accurate results. Both placed traps by expert opinion and moved traps between capture sessions, which

  19. Sampling designs matching species biology produce accurate and affordable abundance indices.

    PubMed

    Harris, Grant; Farley, Sean; Russell, Gareth J; Butler, Matthew J; Selinger, Jeff

    2013-01-01

    Wildlife biologists often use grid-based designs to sample animals and generate abundance estimates. Although sampling in grids is theoretically sound, in application, the method can be logistically difficult and expensive when sampling elusive species inhabiting extensive areas. These factors make it challenging to sample animals and meet the statistical assumption of all individuals having an equal probability of capture. Violating this assumption biases results. Does an alternative exist? Perhaps by sampling only where resources attract animals (i.e., targeted sampling), it would provide accurate abundance estimates more efficiently and affordably. However, biases from this approach would also arise if individuals have an unequal probability of capture, especially if some failed to visit the sampling area. Since most biological programs are resource limited, and acquiring abundance data drives many conservation and management applications, it becomes imperative to identify economical and informative sampling designs. Therefore, we evaluated abundance estimates generated from grid and targeted sampling designs using simulations based on geographic positioning system (GPS) data from 42 Alaskan brown bears (Ursus arctos). Migratory salmon drew brown bears from the wider landscape, concentrating them at anadromous streams. This provided a scenario for testing the targeted approach. Grid and targeted sampling varied by trap amount, location (traps placed randomly, systematically or by expert opinion), and traps stationary or moved between capture sessions. We began by identifying when to sample, and if bears had equal probability of capture. We compared abundance estimates against seven criteria: bias, precision, accuracy, effort, plus encounter rates, and probabilities of capture and recapture. One grid (49 km(2) cells) and one targeted configuration provided the most accurate results. Both placed traps by expert opinion and moved traps between capture sessions

  20. Correction of radiation absorption on biological samples using Rayleigh to Compton scattering ratio

    NASA Astrophysics Data System (ADS)

    Pereira, Marcelo O.; Conti, Claudio de Carvalho; dos Anjos, Marcelino J.; Lopes, Ricardo T.

    2012-06-01

    The aim of this work was to develop a method to correct the absorbed radiation (the mass attenuation coefficient curve) in low energy (E < 30 keV) applied to a biological matrix based on the Rayleigh to Compton scattering ratio and the effective atomic number. For calibration, scattering measurements were performed on standard samples of radiation produced by a gamma-ray source of 241Am (59.54 keV) also applied to certified biological samples of milk powder, hay powder and bovine liver (NIST 1557B). In addition, six methods of effective atomic number determination were used as described in literature to determinate the Rayleigh to Compton scattering ratio (R/C), in order to calculate the mass attenuation coefficient. The results obtained by the proposed method were compared with those obtained using the transmission method. The experimental results were in good agreement with transmission values suggesting that the method to correct radiation absorption presented in this paper is adequate for biological samples.

  1. Synthesis of surface nano-molecularly imprinted polymers for sensitive baicalin detection from biological samples

    PubMed Central

    Gu, Xiaoli; He, Hongliang; Wang, Chong-Zhi; Gao, Yankun; Zhang, Hongjuan; Hong, Junli; Du, Shuhu; Chen, Lina; Yuan, Chun-Su

    2015-01-01

    Surface molecularly imprinted polymers (MIP@SBA-15) imprinted on the surface of hybrid nanostructured organic/inorganic materials (SBA-15) were prepared for the selective extraction and detection of baicalin (BA) from biological samples. The surface morphologies and characteristics of the imprinted and non-imprinted polymers were characterized by Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermo–gravimetric analysis (TGA) and nitrogen adsorption–desorption isotherms. The results indicated that the polymers were successfully grafted on the surface of SBA-15 and possessed a highly ordered mesoporous structure. In binding tests, MIP@SBA-15 reached saturated adsorption within 80 min and exhibited significant specific recognition toward BA with large adsorption capacity. Meanwhile, the prepared MIP@SBA-15 was used as a selective sorbent for solid-phase extraction of BA from biological samples. Recoveries of BA from the liver and spleen ranged from 90.6% to 90.9% with RSD < 3.7%. All these results reveal that this method is simple, rapid and sensitive for effectively extracting and detecting trace BA in biological samples. PMID:26257892

  2. Sequential injection anodic stripping voltammetry with monosegmented flow and in-line UV digestion for determination of Zn(II), Cd(II), Pb(II) and Cu(II) in water samples.

    PubMed

    Siriangkhawut, Watsaka; Grudpan, Kate; Jakmunee, Jaroon

    2011-06-15

    A cost-effective sequential injection system incorporating with an in-line UV digestion for breakdown of organic matter prior to voltammetric determination of Zn(II), Cd(II), Pb(II) and Cu(II) by anodic stripping voltammetry (ASV) on a hanging mercury drop electrode (HMDE) of a small scale voltammetric cell was developed. A low-cost small scale voltammetric cell was fabricated from disposable pipet tip and microcentrifuge tube with volume of about 3 mL for conveniently incorporated with the SI system. A home-made UV digestion unit was fabricated employing a small size and low wattage UV lamps and flow reactor made from PTFE tubing coiled around the UV lamp. An in-line single standard calibration or a standard addition procedure was developed employing a monosegmented flow technique. Performance of the proposed system was tested for in-line digestion of model water samples containing metal ions and some organic ligands such as strong organic ligand (EDTA) or intermediate organic ligand (humic acid). The wet acid digestion method (USEPA 3010a) was used as a standard digestion method for comparison. Under the optimum conditions, with deposition time of 180 s, linear calibration graphs in range of 10-300 μg L(-1) Zn(II), 5-200 μg L(-1) Cd(II), 10-200 μg L(-1) Pb(II), 20-400 μg L(-1) Cu(II) were obtained with detection limit of 3.6, 0.1, 0.7 and 4.3 μg L(-1), respectively. Relative standard deviation were 4.2, 2.6, 3.1 and 4.7% for seven replicate analyses of 27 μg L(-1) Zn(II), 13 μg L(-1) Cd(II), 13 μg L(-1) Pb(II) and 27 μg L(-1) Cu(II), respectively. The system was validated by certified reference material of trace metals in natural water (SRM 1640 NIST). The developed system was successfully applied for speciation of Cd(II) Pb(II) and Cu(II) in ground water samples collected from nearby zinc mining area.

  3. Extractive spectrophotometric determination of Cobalt(II) in synthetic and pharmaceutical samples using Cyanex 923.

    PubMed

    Reddy, B Ramachandra; Radhika, P; Kumar, J Rajesh; Priya, D Neela; Rajgopal, K

    2004-02-01

    Cyanex 923 has been proposed as a sensitive analytical reagent for the direct extractive spectrophotometric determination of cobalt(II). Cobalt(II) forms a blue-colored complex with Cyanex 923 in the organic phase. The maximum absorbance of the complex is measured at 635 nm. Beer's law was obeyed in the range 58.9 - 589.0 microg of cobalt. The molar absorptivitiy and Sandell's sensitivity of the complex was calculated to be 6.79 x 10920 l mol(-1) cm(-1) and 0.088 microg cm(-2), respectively. The nature of the extracted species was found to be Co(SCN)2 x 2S. An excellent linearity with a correlation coefficient value of 0.999 was obtained for the Co(II)-Cyanex 923 complex. Stability and regeneration of the reagent (Cyanex 923) for reuse is the main advantage of the present method. The method was successfully applied to the determination of cobalt in synthetic mixtures and pharmaceutical samples was found to give values close to the actual ones. Standard alloy samples, such as high-speed tool BCS 484 and 485, have been tested for the determination of cobalt for the purpose of validating the present method. The results of the proposed method are comparable with atomic absorption spectrometry and were found to be in good agreement.

  4. Attempts to develop a new nuclear measurement technique of β-glucuronidase levels in biological samples

    NASA Astrophysics Data System (ADS)

    Ünak, T.; Avcibasi, U.; Yildirim, Y.; Çetinkaya, B.

    2003-01-01

    β-Glucuronidase is one of the most important hydrolytic enzymes in living systems and plays an essential role in the detoxification pathway of toxic materials incorporated into the metabolism. Some organs, especially liver and some tumour tissues, have high level of β-glucuronidase activity. As a result the enzymatic activity of some kind of tumour cells, the radiolabelled glucuronide conjugates of cytotoxic, as well as radiotoxic compounds have potentially very valuable diagnostic and therapeutic applications in cancer research. For this reason, a sensitive measurement of β-glucuronidase levels in normal and tumour tissues is a very important step for these kinds of applications. According to the classical measurement method of β-glucuronidase activity, in general, the quantity of phenolphthalein liberated from its glucuronide conjugate, i.e. phenolphthalein-glucuronide, by β-glucuronidase has been measured by use of the spectrophotometric technique. The lower detection limit of phenolphthalein by the spectrophotometric technique is about 1 3 μg. This means that the β-glucuronidase levels could not be detected in biological samples having lower levels of β-glucuronidase activity and therefore the applications of the spectrophotometric technique in cancer research are very seriously limited. Starting from this consideration, we recently attempted to develop a new nuclear technique to measure much lower concentrations of β-glucuronidase in biological samples. To improve the detection limit, phenolphthalein-glucuronide and also phenyl-N-glucuronide were radioiodinated with 131I and their radioactivity was measured by use of the counting technique. Therefore, the quantity of phenolphthalein or aniline radioiodinated with 131I and liberated by the deglucuronidation reactivity of β-glucuronidase was used in an attempt to measure levels lower than the spectrophotometric measurement technique. The results obtained clearly verified that 0.01 pg level of

  5. Attempts to develop a new nuclear measurement technique of β-glucuronidase levels in biological samples

    NASA Astrophysics Data System (ADS)

    Ünak, T.; Avcibasi, U.; Yildirim, Y.; Çetinkaya, B.

    2003-01-01

    β-Glucuronidase is one of the most important hydrolytic enzymes in living systems and plays an essential role in the detoxification pathway of toxic materials incorporated into the metabolism. Some organs, especially liver and some tumour tissues, have high level of β-glucuronidase activity. As a result the enzymatic activity of some kind of tumour cells, the radiolabelled glucuronide conjugates of cytotoxic, as well as radiotoxic compounds have potentially very valuable diagnostic and therapeutic applications in cancer research. For this reason, a sensitive measurement of β-glucuronidase levels in normal and tumour tissues is a very important step for these kinds of applications. According to the classical measurement method of β-glucuronidase activity, in general, the quantity of phenolphthalein liberated from its glucuronide conjugate, i.e. phenolphthalein-glucuronide, by β-glucuronidase has been measured by use of the spectrophotometric technique. The lower detection limit of phenolphthalein by the spectrophotometric technique is about 1-3 μg. This means that the β-glucuronidase levels could not be detected in biological samples having lower levels of β-glucuronidase activity and therefore the applications of the spectrophotometric technique in cancer research are very seriously limited. Starting from this consideration, we recently attempted to develop a new nuclear technique to measure much lower concentrations of β-glucuronidase in biological samples. To improve the detection limit, phenolphthalein-glucuronide and also phenyl-N-glucuronide were radioiodinated with 131I and their radioactivity was measured by use of the counting technique. Therefore, the quantity of phenolphthalein or aniline radioiodinated with 131I and liberated by the deglucuronidation reactivity of β-glucuronidase was used in an attempt to measure levels lower than the spectrophotometric measurement technique. The results obtained clearly verified that 0.01 pg level of

  6. Synthesis, spectral characterization and biological evaluation of Mn(II), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) complexes with thiosemicarbazone ending by pyrazole and pyridyl rings

    NASA Astrophysics Data System (ADS)

    Yousef, T. A.; Abu El-Reash, G. M.; Al-Jahdali, M.; El-Rakhawy, El-Bastawesy R.

    2014-08-01

    Here we present the synthesis of the new Mn(II), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) complexes with chelating ligand (Z)-(2-((1,3-diphenyl-1H-pyrazol-4-yl)methylene) hydrazinyl)(pyridin-2-ylamino)methanethiol. All the complexes were characterized by elemental analysis, IR, 1H NMR, UV-vis, magnetic susceptibility measurements and EPR spectral studies. IR spectra of complexes showed that the ligand behaves as NN neutral bidentate, NSN mononegative tridentate and NSNN mononegative tetradentate. The electronic spectra and the magnetic measurements suggested the octahedral geometry for all complexes as well as the EPR confirmed the tetragonal distorted octahedral for Cu(II) complex. Cd(II) complex showed the highest inhibitory antioxidant activity either using ABTS method. The SOD-like activity exhibited those Cd(II) and Zn(II) complexes have strong antioxidative properties. We tested the synthesized compounds for antitumor activity and showed that the ability to kill liver (HePG2) and breast (MCF-7) cancer cells definitely.

  7. Trace iodine quantitation in biological samples by mass spectrometric methods: the optimum internal standard.

    PubMed

    Dyke, Jason V; Dasgupta, Purnendu K; Kirk, Andrea B

    2009-07-15

    Accurate quantitation of iodine in biological samples is essential for studies of nutrition and medicine, as well as for epidemiological studies for monitoring intake of this essential nutrient. Despite the importance of accurate measurement, a standardized method for iodine analysis of biological samples is yet to be established. We have evaluated the effectiveness of (72)Ge, (115)In, and (129)I as internal standards for measurement of iodine in milk and urine samples by induction coupled plasma mass spectrometry (ICP-MS) and of (35)Cl(18)O(4)(-), (129)I(-), and 2-chlorobenzenesulfonate (2-CBS) as internal standards for ion chromatography-tandem mass spectrometry (IC-MS/MS). We found recovery of iodine to be markedly low when IC-MS/MS was used without an internal standard. Percent recovery was similarly low using (35)Cl(18)O(4) as an internal standard for milk and unpredictable when used for urine. 2-Chlorobenzebenzenesulfonate provided accurate recovery of iodine from milk, but overestimated iodine in urine samples by as much as a factor of 2. Percent recovery of iodine from milk and urine using ICP-MS without an internal standard was approximately 120%. Use of (115)In predicted approximately 60% of known values for both milk and urine samples. (72)Ge provided reasonable and consistent percent recovery for iodine in milk samples (approximately 108%) but resulted in approximately 80% recovery of iodine from urine. Use of (129)I as an internal standard resulted in excellent recovery of iodine from both milk and urine samples using either IC-MS/MS and ICP-MS.

  8. The Tip-Sample Interaction in Atomic Force Microscopy and its Implications for Biological Applications.

    NASA Astrophysics Data System (ADS)

    Baselt, David Randall

    This thesis describes the construction of an atomic force microscope and its application to the study of tip -sample interactions, primarily through the use of friction and hardness (elasticity) imaging. Part one describes the atomic force microscope, which consists of a scanned-cantilever stage (chapter 2); a versatile digital signal processor-based control system with self-optimizing feedback, lock-in amplifier emulation (for hardness imaging), and macro programmability (chapter 3); and image processing software (chapter 4). Part two describes a number of results that have helped to characterize the tip-sample interaction and the contact imaging modes used for its study. Meniscus forces act laterally as well as normally, and that they vary with position (chapter 5). Friction measurements couple with scanner position and feedback, and the meniscus effects friction images (chapter 6). Sliding of the tip over the sample surface introduces slope-dependence into hardness measurements (chapter 7). Dull tips can create prominent topography artifacts even on very flat surfaces (chapter 8). In an investigation of collagen fibrils, AFM has revealed the characteristic 65 nm banding pattern, a second, minor banding pattern, and microfibrils that run along the fibril axis. The distribution of proteoglycans along the fibrils creates a characteristic pattern in friction images. Although imaging in water reduces interaction forces, water can also make biological samples more sensitive to force. However, for robust biological samples imaged in air, tip shape presents a greater obstacle than tip -sample interaction forces to obtaining high-resolution images. Tip contamination increases tip-sample friction and can occasionally improve resolution (chapter 9). For a separate project I have designed a general -purpose nearfield scanning optical microscope (chapter 10).

  9. The XAS model of dissolved Cu(II) and its significance to biological electron transfer

    NASA Astrophysics Data System (ADS)

    Frank, Patrick; Benfatto, Maurizio; Hedman, Britt; Hodgson, Keith O.

    2009-11-01

    The standard model for dissolved Cu(II) portrays the complex ion as an axially elongated, equatorially planar octahedron. Using EXAFS and MXAN analyses of copper K-edge XAS spectra, new structural models for dissolved [Cu(aq)]2+ and [Cu(amm)]2+ have been determined. These structures uniformly depart from the octahedral model in favour of an axially elongated square pyramidal core. MXAN results also indicate that the equatorial ligands need not be coplanar with copper. Further structural elements include a -z axially localized scatterer at ~3 Å. Even more distant scatterers imply second shell solvent organization, which can vary with the medium. Preliminary results from new extended, k = 18 Å-1, higher resolution copper K-edge XAS data sets are reported. The low symmetry of dissolved Cu(II) ion contradicts the central thesis of the rack-induced bonding hypothesis of copper electron transfer proteins. The asymmetry of biological copper is not a frozen vibronic excited state enforced by a rigid protein scaffold, but is entirely in harmony with the structural ground state of the dissolved aqueous Cu(II) complex ion.

  10. Half-sandwich ruthenium(II) biotin conjugates as biological vectors to cancer cells.

    PubMed

    Babak, Maria V; Plażuk, Damian; Meier, Samuel M; Arabshahi, Homayon John; Reynisson, Jóhannes; Rychlik, Błażej; Błauż, Andrzej; Szulc, Katarzyna; Hanif, Muhammad; Strobl, Sebastian; Roller, Alexander; Keppler, Bernhard K; Hartinger, Christian G

    2015-03-23

    Ruthenium(II)-arene complexes with biotin-containing ligands were prepared so that a novel drug delivery system based on tumor-specific vitamin-receptor mediated endocytosis could be developed. The complexes were characterized by spectroscopic methods and their in vitro anticancer activity in cancer cell lines with various levels of major biotin receptor (COLO205, HCT116 and SW620 cells) was tested in comparison with the ligands. In all cases, coordination of ruthenium resulted in significantly enhanced cytotoxicity. The affinity of Ru(II) -biotin complexes to avidin was investigated and was lower than that of unmodified biotin. Hill coefficients in the range 2.012-2.851 suggest strong positive cooperation between the complexes and avidin. To estimate the likelihood of binding to the biotin receptor/transporter, docking studies with avidin and streptavidin were conducted. These explain, to some extent, the in vitro anticancer activity results and support the conclusion that these novel half-sandwich ruthenium(II)-biotin conjugates may act as biological vectors to cancer cells, although no clear relationship between the cellular Ru content, the cytotoxicity, and the presence of the biotin moiety was observed. PMID:25676245

  11. Synthesis, characterization and biological evaluation of Rutin-zinc(II) flavonoid -metal complex.

    PubMed

    Ikeda, Norma Estefania Andrades; Novak, Estela Maria; Maria, Durvanei Augusto; Velosa, Adélia Segin; Pereira, Regina Mara Silva

    2015-09-01

    Synthesis of compounds analogous to natural products from secondary metabolites, such as flavonoids, is a promising source of novel drugs. Rutin (quercetin-3-O-rutinoside) is a natural flavone, which has, in its chemical structure, different sites for coordination with transition metals and the complexation with these metals enhances its biological properties. Rutin-zinc(II), a flavonoid-metal complex, was synthesized and characterized by UV-VIS, FT-IR, elemental analysis and (1)H NMR. The antioxidant and antitumor activities, as well as the cytotoxicity and in vivo toxicity of this complex were evaluated and compared with the free rutin. Rutin-zinc(II) has not shown any cytotoxicity against normal cells (fibroblasts and HUVECs) or toxicity in BALB/c mice, but has shown antioxidant activity in vitro and cytotoxicity against leukemia (KG1, K562 and Jurkat), multiple myeloma (RPMI8226) and melanoma (B16F10 and SK-Mel-28) cell lines in vitro. In Ehrlich ascites carcinoma model, Rutin-zinc(II) modulated the mitochondrial membrane potential and the expression of genes related to cell cycle progression, angiogenesis and apoptosis.

  12. Toxicological importance of human biomonitoring of metallic and metalloid elements in different biological samples.

    PubMed

    Gil, F; Hernández, A F

    2015-06-01

    Human biomonitoring has become an important tool for the assessment of internal doses of metallic and metalloid elements. These elements are of great significance because of their toxic properties and wide distribution in environmental compartments. Although blood and urine are the most used and accepted matrices for human biomonitoring, other non-conventional samples (saliva, placenta, meconium, hair, nails, teeth, breast milk) may have practical advantages and would provide additional information on health risk. Nevertheless, the analysis of these compounds in biological matrices other than blood and urine has not yet been accepted as a useful tool for biomonitoring. The validation of analytical procedures is absolutely necessary for a proper implementation of non-conventional samples in biomonitoring programs. However, the lack of reliable and useful analytical methodologies to assess exposure to metallic elements, and the potential interference of external contamination and variation in biological features of non-conventional samples are important limitations for setting health-based reference values. The influence of potential confounding factors on metallic concentration should always be considered. More research is needed to ascertain whether or not non-conventional matrices offer definitive advantages over the traditional samples and to broaden the available database for establishing worldwide accepted reference values in non-exposed populations.

  13. Potentiometric detection in UPLC as an easy alternative to determine cocaine in biological samples.

    PubMed

    Daems, Devin; van Nuijs, Alexander L N; Covaci, Adrian; Hamidi-Asl, Ezat; Van Camp, Guy; Nagels, Luc J

    2015-07-01

    The analytical methods which are often used for the determination of cocaine in complex biological matrices are a prescreening immunoassay and confirmation by chromatography combined with mass spectrometry. We suggest an ultra-high-pressure liquid chromatography combined with a potentiometric detector, as a fast and practical method to detect and quantify cocaine in biological samples. An adsorption/desorption model was used to investigate the usefulness of the potentiometric detector to determine cocaine in complex matrices. Detection limits of 6.3 ng mL(-1) were obtained in plasma and urine, which is below the maximum residue limit (MRL) of 25 ng mL(-1). A set of seven plasma samples and 10 urine samples were classified identically by both methods as exceeding the MRL or being inferior to it. The results obtained with the UPLC/potentiometric detection method were compared with the results obtained with the UPLC/MS method for samples spiked with varying cocaine concentrations. The intraclass correlation coefficient was 0.997 for serum (n =7) and 0.977 for urine (n =8). As liquid chromatography is an established technique, and as potentiometry is very simple and cost-effective in terms of equipment, we believe that this method is potentially easy, inexpensive, fast and reliable.

  14. Tailored magnetic nanoparticles for direct and sensitive detection of biomolecules in biological samples.

    PubMed

    Fornara, Andrea; Johansson, Petter; Petersson, Karolina; Gustafsson, Stefan; Qin, Jian; Olsson, Eva; Ilver, Dag; Krozer, Anatol; Muhammed, Mamoun; Johansson, Christer

    2008-10-01

    We developed nanoparticles with tailored magnetic properties for direct and sensitive detection of biomolecules in biological samples in a single step. Thermally blocked nanoparticles obtained by thermal hydrolysis, functionalized with specific ligands, are mixed with sample solutions, and the variation of the magnetic relaxation due to surface binding is used to detect the presence of biomolecules. The binding significantly increases the hydrodynamic volume of nanoparticles, thus changing their Brownian relaxation frequency which is measured by a specifically developed AC susceptometer. The system was tested for the presence of Brucella antibodies, a dangerous pathogen causing brucellosis with severe effects both on humans and animals, in serum samples from infected cows and the surface of the nanoparticles was functionalized with lipopolysaccharides (LPS) from Brucella abortus. The hydrodynamic volume of LPS-functionalized particles increased by 25-35% as a result of the binding of the antibodies, measured by changes in the susceptibility in an alternating magnetic field. The method has shown high sensitivity, with detection limit of 0.05 microg x mL(-1) of antibody in the biological samples without any pretreatment. This magnetic-based assay is very sensitive, cost-efficient, and versatile, giving a direct indication whether the animal is infected or not, making it suitable for point-of-care applications. The functionalization of tailored magnetic nanoparticles can be modified to suit numerous homogeneous assays for a wide range of applications. PMID:18754596

  15. Offer of rapid testing and alternative biological samples as practical tools to implement HIV screening programs.

    PubMed

    Parisi, Maria Rita; Soldini, Laura; Di Perri, Giovanni; Tiberi, Simon; Lazzarin, Adriano; Lillo, Flavia B

    2009-10-01

    Implementation of HIV testing has the objective to increase screening, identify and counsel persons with infection, link them to clinical services and reduce transmission. Rapid tests and/or alternative biological samples (like oral fluid) give the option for a better general consent in approaching screening, immediate referral of HIV positives to medical treatment and partner notification. We tested the performance characteristics of an oral fluid-based rapid HIV test (Rapidtest HIV lateral flow-Healthchem diag. LLC) in comparison with routinely utilized methods in a selected population of known positive (N = 121) or negative (N = 754) subjects. The sensitivity of the rapid test was 99.1% (one false negative sample) and the specificity 98.8%. Five negatives showed a faint reactivity, 3 of these were reactive also in the reference test, one with a p24 only reaction in Western blot. If these 3 samples were excluded from the analysis the specificity increases to 99.2%. Results from our study confirm that, although a continuous improvement of the test performance is still needed to minimize false negative and positive results, rapid test and alternative biological samples may contribute to HIV prevention strategies by reaching a larger population particularly when and where regular screening procedures are difficult to obtain. PMID:20128446

  16. A review on determination of steroids in biological samples exploiting nanobio-electroanalytical methods.

    PubMed

    Yadav, Saurabh K; Chandra, Pranjal; Goyal, Rajendra N; Shim, Yoon-Bo

    2013-01-31

    The applications of nanomaterial modified sensors, molecularly imprinting polymer based, aptamer based, and immunosensors have been described in the determination of steroids using electroanalytical techniques. After a brief description of the steroids and assays in biological fluids, the principles of electrochemical detection with the advantages and the limitations of the various sensors are presented. The nanomaterial modified sensors catalyze the oxidation/reduction of steroids and are suitable for sensing them in environmental samples and biological fluids. The determination of steroids based on their reduction has been found more useful in comparison to oxidation as the common metabolites present in the biological fluids do not undergo reduction in the usual potential window and hence, do not interfere in the determination. The sensors based on immunosensors and aptamers were found more sensitive and selective for steroid determination. Conducting polymer modified bio-sensors and microchip devices are suggested as possible future prospects for the ultra sensitive and simultaneous determination of steroids and their metabolites in various samples.

  17. Application of probe electrospray to direct ambient analysis of biological samples.

    PubMed

    Chen, Lee Chuin; Nishidate, Kentaro; Saito, Yuta; Mori, Kunihiko; Asakawa, Daiki; Takeda, Sen; Kubota, Takeo; Terada, Nobuo; Hashimoto, Yutaka; Hori, Hirokazu; Hiraoka, Kenzo

    2008-08-01

    Recently, we have developed probe electrospray ionization (PESI) that uses a solid needle. In this system, the probe needle moves up and down along the vertical axis by a motor-driven system. At the highest position of the probe needle, electrospray is generated by applying a high voltage. In this study, we applied PESI directly to biological samples such as urine, mouse brain, mouse liver, salmon egg, and fruits (orange, banana, etc.). Strong ion signals for almost all the samples were obtained. The amount of liquid sample picked up by the needle is as small as pL or less, making PESI a promising non-invasive technique for detecting biomolecules in living systems such as cells. Therefore, PESI may be useful as a versatile and ready-to-use semi-online analytical tool in the fields of medicine, pharmaceuticals, agriculture, food science, etc. PMID:18623622

  18. MALDI-MS drug analysis in biological samples: opportunities and challenges.

    PubMed

    Steuer, Andrea E; Poetzsch, Michael; Kraemer, Thomas

    2016-09-01

    Drug analysis represents a large field in different disciplines. Plasma is commonly considered to be the biosample of choice for that purpose. However, concentrations often do not represent the levels present within deeper compartments and therefore cannot sufficiently explain efficacy or toxicology of drugs. MALDI-MS in drug analysis is of great interest for high-throughput quantification and particularly spatially resolved tissue imaging. The current perspective article will deal with challenges and opportunities of MALDI-MS drug analysis in different biological samples. A particular focus will be on hair samples. Recent applications were included, reviewed for their instrumental setup and sample preparation and pros and cons as well as future perspectives are critically discussed. PMID:27524467

  19. Mapping molecular orientational distributions for biological sample in 3D (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    HE, Wei; Ferrand, Patrick; Richter, Benjamin; Bastmeyer, Martin; Brasselet, Sophie

    2016-04-01

    Measuring molecular orientation properties is very appealing for scientists in molecular and cell biology, as well as biomedical research. Orientational organization at the molecular scale is indeed an important brick to cells and tissues morphology, mechanics, functions and pathologies. Recent work has shown that polarized fluorescence imaging, based on excitation polarization tuning in the sample plane, is able to probe molecular orientational order in biological samples; however this applies only to information in 2D, projected in the sample plane. To surpass this limitation, we extended this approach to excitation polarization tuning in 3D. The principle is based on the decomposition of any arbitrary 3D linear excitation in a polarization along the longitudinal z-axis, and a polarization in the transverse xy-sample plane. We designed an interferometer with one arm generating radial polarization light (thus producing longitudinal polarization under high numerical aperture focusing), the other arm controlling a linear polarization in the transverse plane. The amplitude ratio between the two arms can vary so as to get any linear polarized excitation in 3D at the focus of a high NA objective. This technique has been characterized by polarimetry imaging at the back focal plane of the focusing objective, and modeled theoretically. 3D polarized fluorescence microscopy is demonstrated on actin stress fibers in non-flat cells suspended on synthetic polymer structures forming supporting pillars, for which heterogeneous actin orientational order could be identified. This technique shows a great potential in structural investigations in 3D biological systems, such as cell spheroids and tissues.

  20. Measurement of Beryllium in Biological Samples by Accelerator Mass Spectrometry: Applications for Studying Chronic Beryllium Disease

    SciTech Connect

    Chiarappa-Zucca, M L; Finkel, R C; Martinelli, R E; McAninch, J E; Nelson, D O; Turtletaub, K W

    2004-04-15

    A method using accelerator mass spectrometry (AMS) has been developed for quantifying attomoles of beryllium (Be) in biological samples. This method provides the sensitivity to trace Be in biological samples at very low doses with the purpose of identifying the molecular targets involved in chronic beryllium disease. Proof of the method was tested by administering 0.001, 0.05, 0.5 and 5.0 {micro}g {sup 9}Be and {sup 10}Be by intraperitoneal injection to male mice and removing spleen, liver, femurs, blood, lung, and kidneys after 24 h exposure. These samples were prepared for AMS analysis by tissue digestion in nitric acid, followed by further organic oxidation with hydrogen peroxide and ammonium persulfate and lastly, precipitation of Be with ammonium hydroxide, and conversion to beryllium oxide at 800 C. The {sup 10}Be/{sup 9}Be ratio of the extracted beryllium oxide was measured by AMS and Be in the original sample was calculated. Results indicate that Be levels were dose-dependent in all tissues and the highest levels were measured in the spleen and liver. The measured {sup 10}Be/{sup 9}Be ratios spanned 4 orders of magnitude, from 10{sup -10} to 10{sup -14}, with a detection limit of 3.0 x 10{sup -14}, which is equivalent to 0.8 attomoles of {sup 10}Be. These results show that routine quantification of nanogram levels of Be in tissues is possible and that AMS is a sensitive method that can be used in biological studies to understand the molecular dosimetry of Be and mechanisms of toxicity.

  1. A novel 4-(2-pyridylazo) resorcinol functionalised magnetic nanosorbent for selective extraction of Cu(II) and Pb(II) ions from food and water samples.

    PubMed

    Asgharinezhad, Ali Akbar; Ebrahimzadeh, Homeira; Rezvani, Mehdi; Shekari, Nafiseh; Loni, Masood

    2014-01-01

    This paper describes a novel sorbent based on 4-(2-pyridylazo) resorcinol functionalised magnetic nanoparticles and its application for the extraction and pre-concentration of trace amounts of Cu(II) and Pb(II) ions. The nanosorbent was characterised by Fourier transform infrared spectroscopy, X-ray powder diffraction, thermal analysis, elemental analysis and scanning electron microscopy. The effects of various parameters such as pH, sorption time, sorbent dosage, elution time, volume and concentration of eluent were investigated. Following the sorption and elution of analytes, Cu(II) and Pb(II) ions were quantified by flame atomic absorption spectrometry. The limits of detection were 0.07 and 0.7 μg l(-1) for Cu(II) and Pb(II), respectively. The relative standard deviations of the method were less than 7%. The sorption capacity of this new sorbent were 92 and 78 mg g(-1) for Cu(II) and Pb(II), respectively. Finally this nanosorbent was applied to the rapid extraction of trace quantities of Cu(II) and Pb(II) ions in different real samples and satisfactory results were obtained. PMID:24827373

  2. A novel 4-(2-pyridylazo) resorcinol functionalised magnetic nanosorbent for selective extraction of Cu(II) and Pb(II) ions from food and water samples.

    PubMed

    Asgharinezhad, Ali Akbar; Ebrahimzadeh, Homeira; Rezvani, Mehdi; Shekari, Nafiseh; Loni, Masood

    2014-01-01

    This paper describes a novel sorbent based on 4-(2-pyridylazo) resorcinol functionalised magnetic nanoparticles and its application for the extraction and pre-concentration of trace amounts of Cu(II) and Pb(II) ions. The nanosorbent was characterised by Fourier transform infrared spectroscopy, X-ray powder diffraction, thermal analysis, elemental analysis and scanning electron microscopy. The effects of various parameters such as pH, sorption time, sorbent dosage, elution time, volume and concentration of eluent were investigated. Following the sorption and elution of analytes, Cu(II) and Pb(II) ions were quantified by flame atomic absorption spectrometry. The limits of detection were 0.07 and 0.7 μg l(-1) for Cu(II) and Pb(II), respectively. The relative standard deviations of the method were less than 7%. The sorption capacity of this new sorbent were 92 and 78 mg g(-1) for Cu(II) and Pb(II), respectively. Finally this nanosorbent was applied to the rapid extraction of trace quantities of Cu(II) and Pb(II) ions in different real samples and satisfactory results were obtained.

  3. A direct solid sampling analysis method for the detection of silver nanoparticles in biological matrices.

    PubMed

    Feichtmeier, Nadine S; Ruchter, Nadine; Zimmermann, Sonja; Sures, Bernd; Leopold, Kerstin

    2016-01-01

    Engineered silver nanoparticles (AgNPs) are implemented in food contact materials due to their powerful antimicrobial properties and so may enter the human food chain. Hence, it is desirable to develop easy, sensitive and fast analytical screening methods for the determination of AgNPs in complex biological matrices. This study describes such a method using solid sampling high-resolution continuum source graphite furnace atomic absorption spectrometry (GFAAS). A recently reported novel evaluation strategy uses the atomization delay of the respective GFAAS signal as significant indicator for AgNPs and thereby allows discrimination of AgNPs from ionic silver (Ag(+)) in the samples without elaborate sample pre-treatment. This approach was further developed and applied to a variety of biological samples. Its suitability was approved by investigation of eight different food samples (parsley, apple, pepper, cheese, onion, pasta, maize meal and wheat flour) spiked with ionic silver or AgNPs. Furthermore, the migration of AgNPs from silver-impregnated polypropylene food storage boxes to fresh pepper was observed and a mussel sample obtained from a laboratory exposure study with silver was investigated. The differences in the atomization delays (Δt(ad)) between silver ions and 20-nm AgNPs vary in a range from -2.01 ± 1.38 s for maize meal to +2.06 ± 1.08 s for mussel tissue. However, the differences were significant in all investigated matrices and so indicative of the presence/absence of AgNPs. Moreover, investigation of model matrices (cellulose, gelatine and water) gives the first indication of matrix-dependent trends. Reproducibility and homogeneity tests confirm the applicability of the method.

  4. A direct solid sampling analysis method for the detection of silver nanoparticles in biological matrices.

    PubMed

    Feichtmeier, Nadine S; Ruchter, Nadine; Zimmermann, Sonja; Sures, Bernd; Leopold, Kerstin

    2016-01-01

    Engineered silver nanoparticles (AgNPs) are implemented in food contact materials due to their powerful antimicrobial properties and so may enter the human food chain. Hence, it is desirable to develop easy, sensitive and fast analytical screening methods for the determination of AgNPs in complex biological matrices. This study describes such a method using solid sampling high-resolution continuum source graphite furnace atomic absorption spectrometry (GFAAS). A recently reported novel evaluation strategy uses the atomization delay of the respective GFAAS signal as significant indicator for AgNPs and thereby allows discrimination of AgNPs from ionic silver (Ag(+)) in the samples without elaborate sample pre-treatment. This approach was further developed and applied to a variety of biological samples. Its suitability was approved by investigation of eight different food samples (parsley, apple, pepper, cheese, onion, pasta, maize meal and wheat flour) spiked with ionic silver or AgNPs. Furthermore, the migration of AgNPs from silver-impregnated polypropylene food storage boxes to fresh pepper was observed and a mussel sample obtained from a laboratory exposure study with silver was investigated. The differences in the atomization delays (Δt(ad)) between silver ions and 20-nm AgNPs vary in a range from -2.01 ± 1.38 s for maize meal to +2.06 ± 1.08 s for mussel tissue. However, the differences were significant in all investigated matrices and so indicative of the presence/absence of AgNPs. Moreover, investigation of model matrices (cellulose, gelatine and water) gives the first indication of matrix-dependent trends. Reproducibility and homogeneity tests confirm the applicability of the method. PMID:26483187

  5. H2S Analysis in Biological Samples Using Gas Chromatography with Sulfur Chemiluminescence Detection

    PubMed Central

    Vitvitsky, Victor; Banerjee, Ruma

    2015-01-01

    Hydrogen sulfide (H2S) is a metabolite and signaling molecule in biological tissues that regulates many physiological processes. Reliable and sensitive methods for H2S analysis are necessary for a better understanding of H2S biology and for the pharmacological modulation of H2S levels in vivo. In this chapter, we describe the use of gas chromatography coupled to sulfur chemiluminescence detection to measure the rates of H2S production and degradation by tissue homogenates at physiologically relevant concentrations of substrates. This method allows separation of H2S from other sulfur compounds and provides sensitivity of detection to ~15 pg (or 0.5 pmol) of H2S per injected sample. PMID:25725519

  6. Temperature-responsive Solid-phase Extraction Column for Biological Sample Pretreatment.

    PubMed

    Akimaru, Michiko; Okubo, Kohei; Hiruta, Yuki; Kanazawa, Hideko

    2015-01-01

    We have developed a novel solid-phase extraction (SPE) system utilizing a temperature-responsive polymer hydrogel-modified stationary phase. Aminopropyl silica beads (average diameter, 40 - 64 μm) were coated with poly(N-isopropylacrylamide) (PNIPAAm)-based thermo-responsive hydrogels. Butyl methacrylate (BMA) and N,N-dimethylaminopropyl acrylamide (DMAPAAm) were used as the hydrophobic and cationic monomers, respectively, and copolymerized with NIPAAm. To evaluate the use of this SPE cartridge for the analysis of drugs and proteins in biological fluids, we studied the separation of phenytoin and theophylline from human serum albumin (HSA) as a model system. The retention of the analytes in an exclusively aqueous eluent could be modulated by changing the temperature and salt content. These results indicated that this temperature-responsive SPE system can be applied to the pretreatment of biological samples for the measurement of serum drug levels.

  7. Measurement of copper in biological samples by flame or electrothermal atomic absorption spectrometry.

    PubMed

    Evenson, M A

    1988-01-01

    Guidelines presented here allow for copper analysis of biological materials by methods that are very sensitive, that require little sample preparation, that have few chemical or spectral interferences, that are inexpensive, and that require only usual care in contamination control. The commercial instruments for FAAS and ETAAS from Perkin-Elmer, from Varian, and from Instrumentation Laboratories Inc. (Allied Analytical Systems) all work well in either the flame or the flameless mode. Background correction techniques are not essential for copper analysis if care is taken with the sample preparation to minimize the background signals. Different types of burners will work adequately if one makes certain that the viscosity of the sample and the control products are similar to the calibration standards. Further, dilution of samples is preferred over increasing the viscosity of the calibration standards by the addition of a protein containing solution or a substance such as glycerol. A 1:10 dilution of blood plasma or serum with dilute nitric acid or water is all that is necessary for copper analysis by the FFAS methods. Cation and anion effects should be tested by bracketing the concentrations of the ions found in the sample with known amounts of ions in the sample solutions. Increasing the concentrations of the ions thought to interfere while keeping the copper concentration constant is another way to test for ion interferences.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3374386

  8. Samples of exact k-stage group sequential designs for Phase II and Pilot studies.

    PubMed

    Kepner, James L; Chang, Myron N

    2004-06-01

    That the test of H(0): p=p(0) versus H(1): p>p(0) can be based on a binomially distributed random variable is widely known among users of statistical methods. What is not generally known is that under certain very general conditions, it is possible to find an exact k-stage group sequential test whose total sample size is bounded above by the sample size for the single stage binomial test. That is, it is possible to find k-stage tests for detecting H(1) for which the sum of the sample sizes at each of the stages is bounded above by the sample size for the standard binomial test. This result is somewhat remarkable since the total sample size under the group sequential test setting can be strictly less than the sample size for the uniformly most powerful (UMP) one-stage binomial test. In other words, exact group sequential tests cannot only save the average sample size but can also save the maximum sample size when they are compared to the standard binomial test. In this paper, implications of existing theory are explored and a web application written by the authors is presented. No new theory is established. Applications are described and methods are demonstrated that use the web application to rapidly create efficient designs for Phase II and Pilot studies that put a minimum number of patients at risk and that facilitate the rapid progression through a scientific research agenda. While couched here in the context of clinical trials, the results may be used in any field of inquiry where inferences are made based on the size of a binomial random variable.

  9. Surface-enhanced Raman scattering detection of silver nanoparticles in environmental and biological samples.

    PubMed

    Guo, Huiyuan; Xing, Baoshan; Hamlet, Leigh C; Chica, Andrea; He, Lili

    2016-06-01

    Growing concerns over the potential release and threat of silver nanoparticles (AgNPs) to environmental and biological systems urge researchers to investigate their fate and behavior. However, current analytical techniques cannot meet the requirements for rapidly, sensitively and reliably probing AgNPs in complex matrices. Surface-enhanced Raman spectroscopy (SERS) has shown great capability for rapid detection of AgNPs based on an indicator molecule that can bind on the AgNP surface. The objective of this study was to exploit SERS to detect AgNPs in environmental and biological samples through optimizing the Raman indicator for SERS. Seven indicator molecules were selected and determined to obtain their SERS signals at optimal concentrations. Among them, 1,2-di(4-pyridyl)ethylene (BPE), crystal violet and ferric dimethyl-dithiocarbamate (ferbam) produced the highest SERS intensities. Further experiments on binding competition between each two of the three candidates showed that ferbam had the highest AgNPs-binding ability. The underlying mechanism lies in the strong binding affinity of ferbam with AgNPs via multiple sulfur atoms. We further validated ferbam to be an effective indicator for SERS detection of as low as 0.1mg/L AgNPs in genuine surface water and 0.57 mg/L in spinach juice. Moreover, limited interference on SERS detection of AgNPs was found from environmentally relevant inorganic ions, organic matter, inorganic particles, as well as biologically relevant components, demonstrating the ferbam-assisted SERS is an effective and sensitive method to detect AgNPs in complex environmental and biological samples.

  10. Systematic ratio normalization of gas chromatography signals for biological sample discrimination and biomarker discovery.

    PubMed

    Lehallier, Benoist; Ratel, Jérémy; Hanafi, Mohamed; Engel, Erwan

    2012-07-01

    The present paper introduces a new gas chromatography data processing procedure dubbed systematic ratio normalization (SRN) enabling to improve both sample set discrimination and biomarker identification. SRN consists in (1) calculating, for each sample, all the log-ratios between abundances of chromatography-analyzed compounds, then (2) selecting the log-ratio(s) that best maximize the discrimination between sample-sets. The relevance of SRN was evaluated on two data sets acquired through gas chromatography-mass spectrometry as part of separate studies designed (i) to discriminate source-origins between vegetable oils analyzed via an analytical system exposed to instrument drift (data set 1) and (ii) to discriminate animal feed between meat samples aged for different durations (data set 2). Applying SRN to raw data made it possible to obtain robust discrimination models for the two data sets by enhancing the contribution to the data variance of the factor-of-interest while stabilizing the contribution of the disturbance factor. The most discriminant log-ratios were shown to employ the most relevant biomarkers presenting relative independence of the factor-of-interest as well as co-behavior of the disturbance effects potentially biasing the discrimination, such as instrument drift or sample biochemical changes. SRN can be run a posteriori on any data set, and might be generalizable to most of separating methods. PMID:22704370

  11. Dithizone modified magnetic nanoparticles for fast and selective solid phase extraction of trace elements in environmental and biological samples prior to their determination by ICP-OES.

    PubMed

    Cheng, Guihong; He, Man; Peng, Hanyong; Hu, Bin

    2012-01-15

    A fast and simple method for analysis of trace amounts of Cr(III), Cu(II), Pb(II) and Zn(II) in environmental and biological samples was developed by combining magnetic solid phase extraction (MSPE) with inductively coupled plasma-optical emission spectrometry (ICP-OES) detection. Dithizone modified silica-coated magnetic Fe(3)O(4) nanoparticles (H(2)Dz-SCMNPs) were prepared and used for MSPE of trace amounts of Cr(III), Cu(II), Pb(II) and Zn(II). The prepared magnetic nanoparticles were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR). The factors affecting the extraction of the target metal ions such as pH, sample volume, eluent, and interfering ions had been investigated and the adsorption mechanism of the target metals on the self-prepared H(2)Dz-SCMNPs was investigated by FT-IR and X-ray photo electron spectroscopy (XPS). Under the optimized conditions, the detection limits of the developed method for Cr(III), Cu(II), Pb(II) and Zn(II) were 35, 11, 62, and 8ngL(-1), respectively, with the enrichment factor of 100. The relative standard deviations (RSDs, c=10μgL(-1), n=7) were in the range of 1.7-3.1% and the linear range was 0.1-100μgL(-1). The proposed method had been validated by two certified reference materials (GSBZ50009-88 environmental water and GBW07601 human hair), and the determined values were in good agreement with the certified values. The method was also applied for the determination of trace metals in real water and human hair samples with recoveries in the range of 85-110% for the spiked samples. The developed MSPE-ICP-OES method has the advantages of simplicity, rapidity, selectivity, high extraction efficiency and is suitable for the analysis of samples with large volume and complex matrix. PMID:22265534

  12. [Identification of two interference peaks during dioxin analysis for biological samples].

    PubMed

    Ren, Daiwei; Liang, Tao; Li, Gang; Zhang, Haidong; Wang, Pu; Xiao, Ke; Li, Yingming; Zhang, Qinghua

    2014-09-01

    Two interference peaks which generally appeared in company with 13C labeled 2,3,7,8-tetrachlorodibenzofuran (13C12-2,3,7,8-TCDF) in the same ion channel during dioxin analysis for biological samples were identified using high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS) and high resolution gas chromatography/low resolution mass spectrometry (HRGC/LRMS). It was firstly inferred that the interference peaks should be the two isomers of dichlorodiphenyldichloroethylene (DDE), which was a breakdown product of dichlorodiphenyltrichloroethane (DDT), one of the typical organic chlorine pesticides (OCPs). Thereafter, the standard solution of DDE including o,p'-DDE and p,p'-DDE was analyzed for confirmation. By evaluation of the peak separation in HRGC/HRMS, comparison of the GC retention times and ion abundance ratios of the two interference peaks in real samples with the two DDE isomers in standard solution, the interference peaks were finally confirmed as o,p'-DDE and p,p'-DDE in sequence on a DB-5MS column. This study provided valuable information for accurate identification of dioxin compounds during the biological sample analysis.

  13. Bayesian Model Comparison and Parameter Inference in Systems Biology Using Nested Sampling

    PubMed Central

    Pullen, Nick; Morris, Richard J.

    2014-01-01

    Inferring parameters for models of biological processes is a current challenge in systems biology, as is the related problem of comparing competing models that explain the data. In this work we apply Skilling's nested sampling to address both of these problems. Nested sampling is a Bayesian method for exploring parameter space that transforms a multi-dimensional integral to a 1D integration over likelihood space. This approach focusses on the computation of the marginal likelihood or evidence. The ratio of evidences of different models leads to the Bayes factor, which can be used for model comparison. We demonstrate how nested sampling can be used to reverse-engineer a system's behaviour whilst accounting for the uncertainty in the results. The effect of missing initial conditions of the variables as well as unknown parameters is investigated. We show how the evidence and the model ranking can change as a function of the available data. Furthermore, the addition of data from extra variables of the system can deliver more information for model comparison than increasing the data from one variable, thus providing a basis for experimental design. PMID:24523891

  14. Bayesian model comparison and parameter inference in systems biology using nested sampling.

    PubMed

    Pullen, Nick; Morris, Richard J

    2014-01-01

    Inferring parameters for models of biological processes is a current challenge in systems biology, as is the related problem of comparing competing models that explain the data. In this work we apply Skilling's nested sampling to address both of these problems. Nested sampling is a Bayesian method for exploring parameter space that transforms a multi-dimensional integral to a 1D integration over likelihood space. This approach focuses on the computation of the marginal likelihood or evidence. The ratio of evidences of different models leads to the Bayes factor, which can be used for model comparison. We demonstrate how nested sampling can be used to reverse-engineer a system's behaviour whilst accounting for the uncertainty in the results. The effect of missing initial conditions of the variables as well as unknown parameters is investigated. We show how the evidence and the model ranking can change as a function of the available data. Furthermore, the addition of data from extra variables of the system can deliver more information for model comparison than increasing the data from one variable, thus providing a basis for experimental design. PMID:24523891

  15. Synthesis, characterization, electrochemical and biological studies on some metal(II) Schiff base complexes containing quinoxaline moiety

    NASA Astrophysics Data System (ADS)

    Justin Dhanaraj, Chellaian; Johnson, Jijo

    2014-01-01

    Novel Co(II), Ni(II), Cu(II) and Zn(II) complexes of Schiff base derived from quinoxaline-2,3-(1,4H)-dione and 4-aminoantipyrine (QDAAP) were synthesized. The ligand and its complexes were characterized by elemental analyses, molar conductance, magnetic susceptibility measurements, FTIR, UV-Vis., mass and 1H NMR spectral studies. The X band ESR spectrum of the Cu(II) complex at 300 and 77 K were also recorded. Thermal studies of the ligand and its complexes show the presence of coordinated water in the Ni(II) and Zn(II) complexes. The coordination behavior of QDAAP is also discussed. All the complexes are mono nuclear and tetrahedral geometry was found for Co(II) complex. For the Ni(II) and Zn(II) complexes, octahedral geometry was assigned and for the Cu(II) complex, square planar geometry has been suggested. The grain size of the complexes was estimated using powder XRD. The surface morphology of the compounds was studied using SEM analysis. Electrochemical behavior of the synthesized complexes in DMF at room temperature was investigated by cyclic voltammetry. The in vitro biological screening of QDAAP and its metal complexes were tested against bacterial species Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. The fungal species include Aspergillus niger, Aspergillus flavus and Candida albicans. The DNA cleavage activity of QDAAP and its complexes were also discussed.

  16. Synthesis, characterization, electrochemical and biological studies on some metal(II) Schiff base complexes containing quinoxaline moiety.

    PubMed

    Dhanaraj, Chellaian Justin; Johnson, Jijo

    2014-01-24

    Novel Co(II), Ni(II), Cu(II) and Zn(II) complexes of Schiff base derived from quinoxaline-2,3-(1,4H)-dione and 4-aminoantipyrine (QDAAP) were synthesized. The ligand and its complexes were characterized by elemental analyses, molar conductance, magnetic susceptibility measurements, FTIR, UV-Vis., mass and (1)H NMR spectral studies. The X band ESR spectrum of the Cu(II) complex at 300 and 77K were also recorded. Thermal studies of the ligand and its complexes show the presence of coordinated water in the Ni(II) and Zn(II) complexes. The coordination behavior of QDAAP is also discussed. All the complexes are mono nuclear and tetrahedral geometry was found for Co(II) complex. For the Ni(II) and Zn(II) complexes, octahedral geometry was assigned and for the Cu(II) complex, square planar geometry has been suggested. The grain size of the complexes was estimated using powder XRD. The surface morphology of the compounds was studied using SEM analysis. Electrochemical behavior of the synthesized complexes in DMF at room temperature was investigated by cyclic voltammetry. The in vitro biological screening of QDAAP and its metal complexes were tested against bacterial species Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. The fungal species include Aspergillus niger, Aspergillus flavus and Candida albicans. The DNA cleavage activity of QDAAP and its complexes were also discussed.

  17. 3D nanoscale imaging of biological samples with laboratory-based soft X-ray sources

    NASA Astrophysics Data System (ADS)

    Dehlinger, Aurélie; Blechschmidt, Anne; Grötzsch, Daniel; Jung, Robert; Kanngießer, Birgit; Seim, Christian; Stiel, Holger

    2015-09-01

    In microscopy, where the theoretical resolution limit depends on the wavelength of the probing light, radiation in the soft X-ray regime can be used to analyze samples that cannot be resolved with visible light microscopes. In the case of soft X-ray microscopy in the water-window, the energy range of the radiation lies between the absorption edges of carbon (at 284 eV, 4.36 nm) and oxygen (543 eV, 2.34 nm). As a result, carbon-based structures, such as biological samples, posses a strong absorption, whereas e.g. water is more transparent to this radiation. Microscopy in the water-window, therefore, allows the structural investigation of aqueous samples with resolutions of a few tens of nanometers and a penetration depth of up to 10μm. The development of highly brilliant laser-produced plasma-sources has enabled the transfer of Xray microscopy, that was formerly bound to synchrotron sources, to the laboratory, which opens the access of this method to a broader scientific community. The Laboratory Transmission X-ray Microscope at the Berlin Laboratory for innovative X-ray technologies (BLiX) runs with a laser produced nitrogen plasma that emits radiation in the soft X-ray regime. The mentioned high penetration depth can be exploited to analyze biological samples in their natural state and with several projection angles. The obtained tomogram is the key to a more precise and global analysis of samples originating from various fields of life science.

  18. Quantitative LC-MS/MS Glycomic Analysis of Biological Samples Using AminoxyTMT.

    PubMed

    Zhou, Shiyue; Hu, Yunli; Veillon, Lucas; Snovida, Sergei I; Rogers, John C; Saba, Julian; Mechref, Yehia

    2016-08-01

    Protein glycosylation plays an important role in various biological processes, such as modification of protein function, regulation of protein-protein interactions, and control of turnover rates of proteins. Moreover, glycans have been considered as potential biomarkers for many mammalian diseases and development of aberrant glycosylation profiles is an important indicator of the pathology of a disease or cancer. Hence, quantitation is an important aspect of a comprehensive glycomics study. Although numerous MS-based quantitation strategies have been developed in the past several decades, some issues affecting sensitivity and accuracy of quantitation still exist, and the development of more effective quantitation strategies is still required. Aminoxy tandem mass tag (aminoxyTMT) reagents are recently commercialized isobaric tags which enable relative quantitation of up to six different glycan samples simultaneously. In this study, liquid chromatography and mass spectrometry conditions have been optimized to achieve reliable LC-MS/MS quantitative glycomic analysis using aminoxyTMT reagents. Samples were resuspended in 0.2 M sodium chloride solution to promote the formation of sodium adduct precursor ions, which leads to higher MS/MS reporter ion yields. This method was first evaluated with glycans from model glycoproteins and pooled human blood serum samples. The observed variation of reporter ion ratios was generally less than 10% relative to the theoretical ratio. Even for the highly complex minor N-glycans, the variation was still below 15%. This strategy was further applied to the glycomic profiling of N-glycans released from blood serum samples of patients with different esophageal diseases. Our results demonstrate the benefits of utilizing aminoxyTMT reagents for reliable quantitation of biological glycomic samples. PMID:27377957

  19. The correlation of arsenic levels in drinking water with the biological samples of skin disorders.

    PubMed

    Kazi, Tasneem Gul; Arain, Muhammad Balal; Baig, Jameel Ahmed; Jamali, Muhammad Khan; Afridi, Hassan Imran; Jalbani, Nusrat; Sarfraz, Raja Adil; Shah, Abdul Qadir; Niaz, Abdul

    2009-01-15

    Arsenic (As) poisoning has become a worldwide public health concern. The skin is quite sensitive to As and skin lesions are the most common and earliest nonmalignant effects associated to chronic As exposure. In 2005-2007, a survey was carried out on surface and groundwater arsenic contamination and relationships between As exposure via the drinking water and related adverse health effects (melanosis and keratosis) on villagers resides on the banks of Manchar lake, southern part of Sindh, Pakistan. We screened the population from arsenic-affected villages, 61 to 73% population were identified patients suffering from chronic arsenic toxicity. The effects of As toxicity via drinking water were estimated by biological samples (scalp hair and blood) of adults (males and females), have or have not skin problem (n=187). The referent samples of both genders were also collected from the areas having low level of As (<10 microg/L) in drinking water (n=121). Arsenic concentration in drinking water and biological samples were analyzed using electrothermal atomic absorption spectrometry. The range of arsenic concentrations in lake surface water was 35.2-158 microg/L, which is 3-15 folds higher than World Health Organization [WHO, 2004. Guidelines for drinking-water quality third ed., WHO Geneva Switzerland.]. It was observed that As concentration in the scalp hair and blood samples were above the range of permissible values 0.034-0.319 microg As/g for hair and <0.5-4.2 microg/L for blood. The linear regressions showed good correlations between arsenic concentrations in water versus hair and blood samples of exposed skin diseased subjects (R2=0.852 and 0.718) as compared to non-diseased subjects (R2=0.573 and 0.351), respectively.

  20. Magnetic induction spectroscopy: non-contact measurement of the electrical conductivity spectra of biological samples

    NASA Astrophysics Data System (ADS)

    Barai, A.; Watson, S.; Griffiths, H.; Patz, R.

    2012-08-01

    Measurement of the electrical conductivity of biological tissues as a function of frequency, often termed ‘bioelectrical impedance spectroscopy (BIS)’, provides valuable information on tissue structure and composition. In implementing BIS though, there can be significant practical difficulties arising from the electrode-sample interface which have likely limited its deployment in industrial applications. In magnetic induction spectroscopy (MIS) these difficulties are eliminated through the use of fully non-contacting inductive coupling between the sensors and sample. However, inductive coupling introduces its own set of technical difficulties, primarily related to the small magnitudes of the induced currents and their proportionality with frequency. This paper describes the design of a practical MIS system incorporating new, highly-phase-stable electronics and compares its performance with that of electrode-based BIS in measurements on biological samples including yeast suspensions in saline (concentration 50-400 g l-1) and solid samples of potato, cucumber, tomato, banana and porcine liver. The shapes of the MIS spectra were in good agreement with those for electrode-based BIS, with a residual maximum discrepancy of 28%. The measurement precision of the MIS was 0.05 S m-1 at 200 kHz, improving to 0.01 S m-1 at a frequency of 20 MHz, for a sample volume of 80 ml. The data-acquisition time for each MIS measurement was 52 s. Given the value of spectroscopic conductivity information and the many advantages of obtaining these data in a non-contacting manner, even through electrically-insulating packaging materials if necessary, it is concluded that MIS is a technique with considerable potential for monitoring bio-industrial processes and product quality.

  1. High resolution x-ray microtomography of biological samples: Requirements and strategies for satisfying them

    SciTech Connect

    Loo, B.W. Jr. ||; Rothman, S.S. |

    1997-02-01

    High resolution x-ray microscopy has been made possible in recent years primarily by two new technologies: microfabricated diffractive lenses for soft x-rays with about 30-50 nm resolution, and high brightness synchrotron x-ray sources. X-ray microscopy occupies a special niche in the array of biological microscopic imaging methods. It extends the capabilities of existing techniques mainly in two areas: a previously unachievable combination of sub-visible resolution and multi-micrometer sample size, and new contrast mechanisms. Because of the soft x-ray wavelengths used in biological imaging (about 1-4 nm), XM is intermediate in resolution between visible light and electron microscopies. Similarly, the penetration depth of soft x-rays in biological materials is such that the ideal sample thickness for XM falls in the range of 0.25 - 10 {mu}m, between that of VLM and EM. XM is therefore valuable for imaging of intermediate level ultrastructure, requiring sub-visible resolutions, in intact cells and subcellular organelles, without artifacts produced by thin sectioning. Many of the contrast producing and sample preparation techniques developed for VLM and EM also work well with XM. These include, for example, molecule specific staining by antibodies with heavy metal or fluorescent labels attached, and sectioning of both frozen and plastic embedded tissue. However, there is also a contrast mechanism unique to XM that exists naturally because a number of elemental absorption edges lie in the wavelength range used. In particular, between the oxygen and carbon absorption edges (2.3 and 4.4 nm wavelength), organic molecules absorb photons much more strongly than does water, permitting element-specific imaging of cellular structure in aqueous media, with no artifically introduced contrast agents. For three-dimensional imaging applications requiring the capabilities of XM, an obvious extension of the technique would therefore be computerized x-ray microtomography (XMT).

  2. Non-destructive high-resolution thermal imaging techniques to evaluate wildlife and delicate biological samples

    NASA Astrophysics Data System (ADS)

    Lavers, C.; Franklin, P.; Franklin, P.; Plowman, A.; Sayers, G.; Bol, J.; Shepard, D.; Fields, D.

    2009-07-01

    Thermal imaging cameras now allows routine monitoring of dangerous yet endangered wildlife in captivity. This study looks at the potential applications of radiometrically calibrated thermal data to wildlife, as well as providing parameters for future materials applications. We present a non-destructive active testing technique suitable for enhancing imagery contrast of thin or delicate biological specimens yielding improved thermal contrast at room temperature, for analysis of sample thermal properties. A broad spectrum of animals is studied with different textured surfaces, reflective and emissive properties in the infra red part of the electromagnetic spectrum. Some surface features offer biomimetic materials design opportunities.

  3. Separation Technique for the Determination of Highly Polar Metabolites in Biological Samples

    PubMed Central

    Iwasaki, Yusuke; Sawada, Takahiro; Hatayama, Kentaro; Ohyagi, Akihito; Tsukuda, Yuri; Namekawa, Kyohei; Ito, Rie; Saito, Koichi; Nakazawa, Hiroyuki

    2012-01-01

    Metabolomics is a new approach that is based on the systematic study of the full complement of metabolites in a biological sample. Metabolomics has the potential to fundamentally change clinical chemistry and, by extension, the fields of nutrition, toxicology, and medicine. However, it can be difficult to separate highly polar compounds. Mass spectrometry (MS), in combination with capillary electrophoresis (CE), gas chromatography (GC), or high performance liquid chromatography (HPLC) is the key analytical technique on which emerging "omics" technologies, namely, proteomics, metabolomics, and lipidomics, are based. In this review, we introduce various methods for the separation of highly polar metabolites. PMID:24957644

  4. Draft Genome Sequences of Five Pseudomonas fluorescens Subclade I and II Strains, Isolated from Human Respiratory Samples.

    PubMed

    Scales, Brittan S; Erb-Downward, John R; LiPuma, John J; Huffnagle, Gary B

    2015-07-30

    We report the draft genomes of five Pseudomonas fluorescens strains, isolated from clinical samples. Phylogenetic analysis places three in subclade I and two in subclade II of the P. fluorescens species complex. The average G+C content and genomic size are 63% and 7.1 Mbp (subclade I) and 59.6% and 6.14 Mbp (subclade II), respectively.

  5. Analysis of zinc in biological samples by flame atomic absorption spectrometry: use of addition calibration technique.

    PubMed

    Dutra, Rosilene L; Cantos, Geny A; Carasek, Eduardo

    2006-01-01

    The quantification of target analytes in complex matrices requires special calibration approaches to compensate for additional capacity or activity in the matrix samples. The standard addition is one of the most important calibration procedures for quantification of analytes in such matrices. However, this technique requires a great number of reagents and material, and it consumes a considerable amount of time throughout the analysis. In this work, a new calibration procedure to analyze biological samples is proposed. The proposed calibration, called the addition calibration technique, was used for the determination of zinc (Zn) in blood serum and erythrocyte samples. The results obtained were compared with those obtained using conventional calibration techniques (standard addition and standard calibration). The proposed addition calibration was validated by recovery tests using blood samples spiked with Zn. The range of recovery for blood serum and erythrocyte samples were 90-132% and 76-112%, respectively. Statistical studies among results obtained by the addition technique and conventional techniques, using a paired two-tailed Student's t-test and linear regression, demonstrated good agreement among them. PMID:16943611

  6. Evaluation of chemical and biological methods for the identification of mutagenic and cytotoxic hazardous waste samples

    SciTech Connect

    Andon, B.; Jackson, M.; Houk, V.; Claxton, L.

    1984-06-01

    To assist in the development of methods for identifying potentially hazardous wastes, the authors have conducted studies on the extraction of toxicants from several solid waste samples. The extracts were tested for toxicity in the Chinese Hamster Ovary (CHO) Cytotoxicity Test and for mutagenic potential in the Salmonella Histidine Reversion Assay. A new technique was also employed which measured the mutagenicity of neat waste samples by coupling Thin Layer Chromatography (TLC) with the Salmonella Histidine Reversion Assay. The wastes selected for study were coke plant waste, herbicide manufacturing acetone-water effluent, and oil refining waste. Three extraction solvents, ethanol (ETOH), dichloromethane (DCM), and dimethylsulfoxide (DMSO), were chosen based on their solubility and compatibility with bioassay procedures. Each sample was divided into three parts and extracted with each of the three solvents separately. All extracts were tested in the Salmonella assay at five dose levels with five Ames tester strains in the presence and in the absence of an exogenous metabolizing system. DMSO and DCM extracts were utilized for CHO cytotoxicity evaluations. The three neat waste samples and two extracts were assayed with the TLC technique. In addition to the biological assessments, the gross chemical parameters for each sample were determined. Results showed that coke plant waste and herbicide mfg. acetone-water were mutagenic to S. typhimurium with the standard plate test. With the TLC technique, the neat coke plant waste was mutagenic and oil refining waste was toxic. Oil refining waste was also toxic to CHO cells.

  7. Micro-organism extraction from biological samples using DEP forces enhanced by osmotic shock.

    PubMed

    Bisceglia, Emilie; Cubizolles, Myriam; Mallard, Frédéric; Vinet, Françoise; Français, Olivier; Le Pioufle, Bruno

    2013-03-01

    On the road towards efficient diagnostics of infectious diseases, sample preparation is considered as the key step and remains a real technical challenge. Finding new methods for extraction of micro-organisms from a complex biological sample remains a major challenge prior to pathogen detection and analysis. This paper reports a new technique for capturing and isolating micro-organisms from a complex sample. To achieve the segregation of pathogens and blood cells, dielectrophoretic forces applied to bioparticles previously subjected to an osmotic shock are successfully implemented within a dedicated microfluidic device. Our device involves an electrode array of interdigitated electrodes, coated with an insulating layer, to minimize electrochemical reactions with the electrolyte and to enable long-time use. The electric field intensity inside the device is optimized, considering the insulating layer, for a given frequency bandwidth, enabling the separation of bioparticles by dielectrophoretic forces. Our predictions are based on analytical models, consistent with numerical simulations (using COMSOL Multiphysics) and correlated to experimental results. The method and device have been shown to extract different types of micro-organisms spiked in a blood cell sample. We strongly believe that this new separation approach may open the way towards a simple device for pathogen extraction from blood and more generally complex samples, with potential advantages of genericness and simplicity.

  8. Design, synthesis and biological evaluation of type-II VEGFR-2 inhibitors based on quinoxaline scaffold.

    PubMed

    Shahin, Mai I; Abou El Ella, Dalal A; Ismail, Nasser S M; Abouzid, Khaled A M

    2014-10-01

    In an effort to develop ATP-competitive VEGFR-2 selective inhibitors, a series of new quinoxaline-based derivatives was designed and synthesized. The target compounds were biologically evaluated for their inhibitory activity against VEGFR-2. The design of the target compounds was accomplished after a profound study of the structure activity relationship (SAR) of type-II VEGFR-2 inhibitors. Among the synthesized compounds, 1-(2-((4-methoxyphenyl)amino)-3-oxo-3,4 dihydroquinoxalin-6-yl)-3-phenylurea (VIIa) displayed the highest inhibitory activity against VEGFR-2. Molecular modeling study involving molecular docking and field alignment was implemented to interpret the variable inhibitory activity of the newly synthesized compounds.

  9. Combined LIBS-Raman for remote detection and characterization of biological samples

    SciTech Connect

    Anderson, Aaron S.; Mukundan, Harshini; Mcinroy, Rhonda E.; Clegg, Samuel M.

    2015-02-07

    Laser-Induced Breakdown Spectroscopy (LIBS) and Raman Spectroscopy have rich histories in the analysis of a wide variety of samples in both in situ and remote configurations. Our team is working on building a deployable, integrated Raman and LIBS spectrometer (RLS) for the parallel elucidation of elemental and molecular signatures under Earth and Martian surface conditions. Herein, results from remote LIBS and Raman analysis of biological samples such as amino acids, small peptides, mono- and disaccharides, and nucleic acids acquired under terrestrial and Mars conditions are reported, giving rise to some interesting differences. A library of spectra and peaks of interest were compiled, and will be used to inform the analysis of more complex systems, such as large peptides, dried bacterial spores, and biofilms. Lastly, these results will be presented and future applications will be discussed, including the assembly of a combined RLS spectroscopic system and stand-off detection in a variety of environments.

  10. Combined LIBS-Raman for remote detection and characterization of biological samples

    DOE PAGESBeta

    Anderson, Aaron S.; Mukundan, Harshini; Mcinroy, Rhonda E.; Clegg, Samuel M.

    2015-02-07

    Laser-Induced Breakdown Spectroscopy (LIBS) and Raman Spectroscopy have rich histories in the analysis of a wide variety of samples in both in situ and remote configurations. Our team is working on building a deployable, integrated Raman and LIBS spectrometer (RLS) for the parallel elucidation of elemental and molecular signatures under Earth and Martian surface conditions. Herein, results from remote LIBS and Raman analysis of biological samples such as amino acids, small peptides, mono- and disaccharides, and nucleic acids acquired under terrestrial and Mars conditions are reported, giving rise to some interesting differences. A library of spectra and peaks of interestmore » were compiled, and will be used to inform the analysis of more complex systems, such as large peptides, dried bacterial spores, and biofilms. Lastly, these results will be presented and future applications will be discussed, including the assembly of a combined RLS spectroscopic system and stand-off detection in a variety of environments.« less

  11. Combined LIBS-Raman for remote detection and characterization of biological samples

    NASA Astrophysics Data System (ADS)

    Anderson, Aaron S.; Mukundan, Harshini; McInroy, Rhonda E.; Clegg, Samuel M.

    2015-03-01

    Laser-Induced Breakdown Spectroscopy (LIBS) and Raman Spectroscopy have rich histories in the analysis of a wide variety of samples in both in situ and remote configurations. Our team is working on building a deployable, integrated Raman and LIBS spectrometer (RLS) for the parallel elucidation of elemental and molecular signatures under Earth and Martian surface conditions. Herein, results from remote LIBS and Raman analysis of biological samples such as amino acids, small peptides, mono- and disaccharides, and nucleic acids acquired under terrestrial and Mars conditions are reported, giving rise to some interesting differences. A library of spectra and peaks of interest were compiled, and will be used to inform the analysis of more complex systems, such as large peptides, dried bacterial spores, and biofilms. These results will be presented and future applications will be discussed, including the assembly of a combined RLS spectroscopic system and stand-off detection in a variety of environments.

  12. Fiber laser-microscope system for femtosecond photodisruption of biological samples

    PubMed Central

    Yavaş, Seydi; Erdogan, Mutlu; Gürel, Kutan; Ilday, F. Ömer; Eldeniz, Y. Burak; Tazebay, Uygar H.

    2012-01-01

    We report on the development of a ultrafast fiber laser-microscope system for femtosecond photodisruption of biological targets. A mode-locked Yb-fiber laser oscillator generates few-nJ pulses at 32.7 MHz repetition rate, amplified up to ∼125 nJ at 1030 nm. Following dechirping in a grating compressor, ∼240 fs-long pulses are delivered to the sample through a diffraction-limited microscope, which allows real-time imaging and control. The laser can generate arbitrary pulse patterns, formed by two acousto-optic modulators (AOM) controlled by a custom-developed field-programmable gate array (FPGA) controller. This capability opens the route to fine optimization of the ablation processes and management of thermal effects. Sample position, exposure time and imaging are all computerized. The capability of the system to perform femtosecond photodisruption is demonstrated through experiments on tissue and individual cells. PMID:22435105

  13. Analytical Methodologies for the Determination of Endocrine Disrupting Compounds in Biological and Environmental Samples

    PubMed Central

    Sosa-Ferrera, Zoraida; Mahugo-Santana, Cristina; Santana-Rodríguez, José Juan

    2013-01-01

    Endocrine-disruptor compounds (EDCs) can mimic natural hormones and produce adverse effects in the endocrine functions by interacting with estrogen receptors. EDCs include both natural and synthetic chemicals, such as hormones, personal care products, surfactants, and flame retardants, among others. EDCs are characterised by their ubiquitous presence at trace-level concentrations and their wide diversity. Since the discovery of the adverse effects of these pollutants on wildlife and human health, analytical methods have been developed for their qualitative and quantitative determination. In particular, mass-based analytical methods show excellent sensitivity and precision for their quantification. This paper reviews recently published analytical methodologies for the sample preparation and for the determination of these compounds in different environmental and biological matrices by liquid chromatography coupled with mass spectrometry. The various sample preparation techniques are compared and discussed. In addition, recent developments and advances in this field are presented. PMID:23738329

  14. Enzymatic determination of carbon-14 labeled L-alanine in biological samples

    SciTech Connect

    Serra, F.; Palou, A.; Pons, A.

    1987-07-15

    A method for determination of L-alanine-specific radioactivity in biological samples is presented. This method is based on the specific enzymatic transformation of L-alanine to pyruvic acid hydrazone catalyzed by the enzyme L-alanine dehydrogenase, formation of the pyruvic acid 2,4-dinitrophenylhydrazone derivative, and quantitative trapping in Amberlite XAD-7 columns, followed by radioactivity counting of the lipophilic eluate. No interferences from other UC-labeled materials such as D-glucose, glycerol, L-lactate, L-serine, L-glutamate, L-phenylalanine, glycine, L-leucine, and L-arginine were observed. This inexpensive and high-speed method is applicable to the simultaneous determination of L-alanine-specific radioactivity for a large number of samples.

  15. An introduction to sample preparation and imaging by cryo-electron microscopy for structural biology

    PubMed Central

    Thompson, Rebecca F.; Walker, Matt; Siebert, C. Alistair; Muench, Stephen P.; Ranson, Neil A.

    2016-01-01

    Transmission electron microscopy (EM) is a versatile technique that can be used to image biological specimens ranging from intact eukaryotic cells to individual proteins >150 kDa. There are several strategies for preparing samples for imaging by EM, including negative staining and cryogenic freezing. In the last few years, cryo-EM has undergone a ‘resolution revolution’, owing to both advances in imaging hardware, image processing software, and improvements in sample preparation, leading to growing number of researchers using cryo-EM as a research tool. However, cryo-EM is still a rapidly growing field, with unique challenges. Here, we summarise considerations for imaging of a range of specimens from macromolecular complexes to cells using EM. PMID:26931652

  16. Phytochemical analysis and biological evaluation of selected African propolis samples from Cameroon and Congo.

    PubMed

    Papachroni, Danai; Graikou, Konstantia; Kosalec, Ivan; Damianakos, Harilaos; Ingram, Verina; Chinou, Ioanna

    2015-01-01

    The objective of this study was the chemical analysis of four selected samples of African propolis (Congo and Cameroon) and their biological evaluation. Twenty-one secondary metabolites belonging to four different chemical groups were isolated from the 70% ethanolic extracts of propolis and their structures were elucidated on the basis of spectral evidence. Three triterpenes and two diprenyl-flavonoids were identified from Congo propolis, which has been investigated for the first time, while thirteen triterpenes, three diprenyl-flavonoids, two monoterpenic alcohols and one fatty acid ester have been identified from Cameroon propolis samples. To our knowledge, the identified diprenyl-flavonoids, as well as five of the isolated and determined triterpenes, are reported for the first time in propolis. Moreover, the total polyphenol content was estimated in all extracts and the antimicrobial activities of all four extracts were studied against six Gram-positive and -negative bacteria and three pathogenic fungi, showing an interesting antibacterial profile.

  17. 4D x-ray phase contrast tomography for repeatable motion of biological samples

    NASA Astrophysics Data System (ADS)

    Hoshino, Masato; Uesugi, Kentaro; Yagi, Naoto

    2016-09-01

    X-ray phase contrast tomography based on a grating interferometer was applied to fast and dynamic measurements of biological samples. To achieve this, the scanning procedure in the tomographic scan was improved. A triangle-shaped voltage signal from a waveform generator to a Piezo stage was used for the fast phase stepping in the grating interferometer. In addition, an optical fiber coupled x-ray scientific CMOS camera was used to achieve fast and highly efficient image acquisitions. These optimizations made it possible to perform an x-ray phase contrast tomographic measurement within an 8 min scan with density resolution of 2.4 mg/cm3. A maximum volume size of 13 × 13 × 6 mm3 was obtained with a single tomographic measurement with a voxel size of 6.5 μm. The scanning procedure using the triangle wave was applied to four-dimensional measurements in which highly sensitive three-dimensional x-ray imaging and a time-resolved dynamic measurement of biological samples were combined. A fresh tendon in the tail of a rat was measured under a uniaxial stretching and releasing condition. To maintain the freshness of the sample during four-dimensional phase contrast tomography, the temperature of the bathing liquid of the sample was kept below 10° using a simple cooling system. The time-resolved deformation of the tendon and each fascicle was measured with a temporal resolution of 5.7 Hz. Evaluations of cross-sectional area size, length of the axis, and mass density in the fascicle during a stretching process provided a basis for quantitative analysis of the deformation of tendon fascicle.

  18. Initial chemical and biological characterization of hydrotreated solvent refined coal (SRC-II) liquids: a status report

    SciTech Connect

    Weimer, W.C.; Wilson, B.W.; Pelroy, R.A.; Craun, J.C.

    1980-07-01

    This report presents the results of both chemical and biomedical research performed on a solvent refined coal (SRC-II) research material (distillate blend) which was produced by the pilot plant facility at Fort Lewis, Washington. Samples of this distillate blend were subjected to research-scale hydrotreatment by Universal Oil Products, Inc., prior to chemical and biological analysis at PNL. The samples are considered to be, in general, generically representative of raw or hydrotreated materials which might be produced by demonstration or commercial-scale facilities. The above described feedstock and hydrotreated materials were analyzed for chemical composition both prior to and after chemical fractionation. The fractionation procedure used was an acid-base-neutral solvent extraction. The fractions produced, as well as the unfractionated materials, were subjected to microbial mutagenesis testing (Ames assay) and to further chemical analysis. The principal components of the unmodified distillate blend are two and three ringed aromatic and heteroatomic species together with high concentrations of phenolic and polynuclear aromatic components relative to typical levels found in petroleum crudes. The Ames assay mutagenic response for the unfractionated material, as well as the fractions produced by the solvent separation, was reduced considerably in the hydrotreated materials compared to that of the feedstock. Total mutagenic response for the hydrotreated products was approximately 1% of that in the untreated feedstock. The concentrations of two important genetically active compound classes, the polynuclear aromatic hydrocarbons and the primary aromatic amines, were considerably reduced in both of the hydrotreated products compared to the feedstock.

  19. Wavelet data processing of micro-Raman spectra of biological samples

    NASA Astrophysics Data System (ADS)

    Camerlingo, C.; Zenone, F.; Gaeta, G. M.; Riccio, R.; Lepore, M.

    2006-02-01

    A wavelet multi-component decomposition algorithm is proposed for processing data from micro-Raman spectroscopy (μ-RS) of biological tissue. The μ-RS has been recently recognized as a promising tool for the biopsy test and in vivo diagnosis of degenerative human tissue pathologies, due to the high chemical and structural information contents of this spectroscopic technique. However, measurements of biological tissues are usually hampered by typically low-level signals and by the presence of noise and background components caused by light diffusion or fluorescence processes. In order to overcome these problems, a numerical method based on discrete wavelet transform is used for the analysis of data from μ-RS measurements performed in vitro on animal (pig and chicken) tissue samples and, in a preliminary form, on human skin and oral tissue biopsy from normal subjects. Visible light μ-RS was performed using a He-Ne laser and a monochromator with a liquid nitrogen cooled charge coupled device equipped with a grating of 1800 grooves mm-1. The validity of the proposed data procedure has been tested on the well-characterized Raman spectra of reference acetylsalicylic acid samples.

  20. Preparation of chitosan grafted graphite composite for sensitive detection of dopamine in biological samples.

    PubMed

    Palanisamy, Selvakumar; Thangavelu, Kokulnathan; Chen, Shen-Ming; Gnanaprakasam, P; Velusamy, Vijayalakshmi; Liu, Xiao-Heng

    2016-10-20

    The accurate detection of dopamine (DA) levels in biological samples such as human serum and urine are essential indicators in medical diagnostics. In this work, we describe the preparation of chitosan (CS) biopolymer grafted graphite (GR) composite for the sensitive and lower potential detection of DA in its sub micromolar levels. The composite modified electrode has been used for the detection of DA in biological samples such as human serum and urine. The GR-CS composite modified electrode shows an enhanced oxidation peak current response and low oxidation potential for the detection of DA than that of electrodes modified with bare, GR and CS discretely. Under optimum conditions, the fabricated GR-CS composite modified electrode shows the DPV response of DA in the linear response ranging from 0.03 to 20.06μM. The detection limit and sensitivity of the sensor were estimated as 0.0045μM and 6.06μA μM(-1)cm(-2), respectively.

  1. Methods to Detect Nitric Oxide and its Metabolites in Biological Samples

    PubMed Central

    Bryan, Nathan S.; Grisham, Matthew B.

    2007-01-01

    Nitric oxide (NO) methodology is a complex and often confusing science and the focus of many debates and discussion concerning NO biochemistry. NO is involved in many physiological processes including regulation of blood pressure, immune response and neural communication. Therefore its accurate detection and quantification is critical to understanding health and disease. Due to the extremely short physiological half life of this gaseous free radical, alternative strategies for the detection of reaction products of NO biochemistry have been developed. The quantification of NO metabolites in biological samples provides valuable information with regards to in vivo NO production, bioavailability and metabolism. Simply sampling a single compartment such as blood or plasma may not always provide an accurate assessment of whole body NO status, particularly in tissues. Therefore, extrapolation of plasma or blood NO status to specific tissues of interest is no longer a valid approach. As a result, methods continue to be developed and validated which allow the detection and quantification of NO and NO-related products/metabolites in multiple compartments of experimental animals in vivo. The methods described in this review is not an exhaustive or comprehensive discussion of all methods available for the detection of NO but rather a description of the most commonly used and practical methods which allow accurate and sensitive quantification of NO products/metabolites in multiple biological matrices under normal physiological conditions. PMID:17664129

  2. A comparison of quantitative reconstruction techniques for PIXE-tomography analysis applied to biological samples

    NASA Astrophysics Data System (ADS)

    Beasley, D. G.; Alves, L. C.; Barberet, Ph.; Bourret, S.; Devès, G.; Gordillo, N.; Michelet, C.; Le Trequesser, Q.; Marques, A. C.; Seznec, H.; da Silva, R. C.

    2014-07-01

    The tomographic reconstruction of biological specimens requires robust algorithms, able to deal with low density contrast and low element concentrations. At the IST/ITN microprobe facility new GPU-accelerated reconstruction software, JPIXET, has been developed, which can significantly increase the speed of quantitative reconstruction of Proton Induced X-ray Emission Tomography (PIXE-T) data. It has a user-friendly graphical user interface for pre-processing, data analysis and reconstruction of PIXE-T and Scanning Transmission Ion Microscopy Tomography (STIM-T). The reconstruction of PIXE-T data is performed using either an algorithm based on a GPU-accelerated version of the Maximum Likelihood Expectation Maximisation (MLEM) method or a GPU-accelerated version of the Discrete Image Space Reconstruction Algorithm (DISRA) (Sakellariou (2001) [2]). The original DISRA, its accelerated version, and the MLEM algorithm, were compared for the reconstruction of a biological sample of Caenorhabditis elegans - a small worm. This sample was analysed at the microbeam line of the AIFIRA facility of CENBG, Bordeaux. A qualitative PIXE-T reconstruction was obtained using the CENBG software package TomoRebuild (Habchi et al. (2013) [6]). The effects of pre-processing and experimental conditions on the elemental concentrations are discussed.

  3. Respondent driven sampling for HIV biological and behavioral surveillance in Latin America and the Caribbean.

    PubMed

    Montealegre, Jane R; Johnston, Lisa G; Murrill, Christopher; Monterroso, Edgar

    2013-09-01

    Since 2005, respondent driven sampling (RDS) has been widely used for HIV biological and behavioral surveillance surveys (BBSS) in Latin America and the Caribbean (LAC). In this manuscript, we provide a focused review of RDS among hard-to-reach high-risk populations in LAC and describe their principal operational, design, and analytical considerations. We reviewed published and unpublished reports, protocols, and manuscripts for RDS studies conducted in LAC between January 1, 2005 and December 31, 2011. We abstracted key operational information and generated summary statistics across all studies. Between 2005 and 2011, 87 RDS studies were conducted in 15 countries in LAC (68 % in South America, 18 % in Mexico and Central America, and 14 % in the Caribbean). The target populations were primarily men who have sex with men (43 %), sex workers (29 %), and drug users (26 %). Study considerations included establishing clear eligibility criteria, measuring social network sizes, collecting specimens for biological testing, among others. Most of the reviewed studies are the first in their respective countries to collect data on hard-to-reach populations and the first attempt to use a probability-based sampling method. These RDS studies allowed researchers and public health practitioners in LAC to access hard-to-reach HIV high-risk populations and collect valuable data on the prevalence of HIV and other infections, as well as related risk behaviors. PMID:23568227

  4. Respondent driven sampling for HIV biological and behavioral surveillance in Latin America and the Caribbean.

    PubMed

    Montealegre, Jane R; Johnston, Lisa G; Murrill, Christopher; Monterroso, Edgar

    2013-09-01

    Since 2005, respondent driven sampling (RDS) has been widely used for HIV biological and behavioral surveillance surveys (BBSS) in Latin America and the Caribbean (LAC). In this manuscript, we provide a focused review of RDS among hard-to-reach high-risk populations in LAC and describe their principal operational, design, and analytical considerations. We reviewed published and unpublished reports, protocols, and manuscripts for RDS studies conducted in LAC between January 1, 2005 and December 31, 2011. We abstracted key operational information and generated summary statistics across all studies. Between 2005 and 2011, 87 RDS studies were conducted in 15 countries in LAC (68 % in South America, 18 % in Mexico and Central America, and 14 % in the Caribbean). The target populations were primarily men who have sex with men (43 %), sex workers (29 %), and drug users (26 %). Study considerations included establishing clear eligibility criteria, measuring social network sizes, collecting specimens for biological testing, among others. Most of the reviewed studies are the first in their respective countries to collect data on hard-to-reach populations and the first attempt to use a probability-based sampling method. These RDS studies allowed researchers and public health practitioners in LAC to access hard-to-reach HIV high-risk populations and collect valuable data on the prevalence of HIV and other infections, as well as related risk behaviors.

  5. Preparation of chitosan grafted graphite composite for sensitive detection of dopamine in biological samples.

    PubMed

    Palanisamy, Selvakumar; Thangavelu, Kokulnathan; Chen, Shen-Ming; Gnanaprakasam, P; Velusamy, Vijayalakshmi; Liu, Xiao-Heng

    2016-10-20

    The accurate detection of dopamine (DA) levels in biological samples such as human serum and urine are essential indicators in medical diagnostics. In this work, we describe the preparation of chitosan (CS) biopolymer grafted graphite (GR) composite for the sensitive and lower potential detection of DA in its sub micromolar levels. The composite modified electrode has been used for the detection of DA in biological samples such as human serum and urine. The GR-CS composite modified electrode shows an enhanced oxidation peak current response and low oxidation potential for the detection of DA than that of electrodes modified with bare, GR and CS discretely. Under optimum conditions, the fabricated GR-CS composite modified electrode shows the DPV response of DA in the linear response ranging from 0.03 to 20.06μM. The detection limit and sensitivity of the sensor were estimated as 0.0045μM and 6.06μA μM(-1)cm(-2), respectively. PMID:27474582

  6. Label-free three-dimensional reconstruction of biological samples (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Aknoun, Sherazade; Bon, Pierre; Savatier, Julien; Monneret, Serge; Wattellier, Benoit F.

    2016-03-01

    We describe the use of spatially incoherent illumination combined with quantitative phase imaging (QPI) [1] to make tridimensional reconstruction of semi-transparent biological samples. Quantitative phase imaging is commonly used with coherent illumination for the relatively simple interpretation of the phase measurement. We propose to use spatially incoherent illumination which is known to increase lateral and axial resolution compared to classical coherent illumination. The goal is to image thick samples with intracellular resolution [2]. The 3D volume is imaged by axially scanning the sample with a quadri-wave lateral shearing interferometer used as a conventional camera while using spatially incoherent white-light illumination (native microscope halogen source) or NIR light. We use a non-modified inverted microscope equipped with a Z-axis piezo stage. A z-stack is recorded by objective translation along the optical axis. The main advantages of this approach are its easy implementation, compared to the other state-of-the-art diffraction tomographic setups, and its speed which makes even label-free 3D living sample imaging possible. A deconvolution algorithm is used to compensate for the loss in contrast due to spatially incoherent illumination. This makes the tomographic volume phase values quantitative. Hence refractive index could be recovered from the optical slices. We will present tomographic reconstruction of cells, thick fixed tissue of few tens of micrometers using white light, and the use of NIR light to reach deeper planes in the tissue.

  7. Label-free three dimensional reconstruction of biological samples (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Aknoun, Sherazade; Bon, Pierre; Savatier, Julien; Monneret, Serge; Wattellier, Benoit F.

    2016-03-01

    We describe the use of spatially incoherent illumination combined with quantitative phase imaging (QPI) [1] to make tridimensional reconstruction of semi-transparent biological samples. Quantitative phase imaging is commonly used with coherent illumination for the relatively simple interpretation of the phase measurement. We propose to use spatially incoherent illumination which is known to increase lateral and axial resolution compared to classical coherent illumination. The goal is to image thick samples with intracellular resolution [2]. The 3D volume is imaged by axially scanning the sample with a quadri-wave lateral shearing interferometer used as a conventional camera while using spatially incoherent white-light illumination (native microscope halogen source) or NIR light. We use a non-modified inverted microscope equipped with a Z-axis piezo stage. A z-stack is recorded by objective translation along the optical axis. The main advantages of this approach are its easy implementation, compared to the other state-of-the-art diffraction tomographic setups, and its speed which makes even label-free 3D living sample imaging possible. A deconvolution algorithm is used to compensate for the loss in contrast due to spatially incoherent illumination. This makes the tomographic volume phase values quantitative. Hence refractive index could be recovered from the optical slices. We will present tomographic reconstruction of cells, thick fixed tissue of few tens of micrometers using white light, and the use of NIR light to reach deeper planes in the tissue.

  8. Methylmercury determination in biological samples using electrothermal atomic absorption spectrometry after acid leaching extraction.

    PubMed

    Saber-Tehrani, Mohammad; Hashemi-Moghaddam, Hamid; Givianrad, Mohammad Hadi; Abroomand-Azar, Parviz

    2006-11-01

    An efficient and sensitive method for the determination of methylmercury in biological samples was developed based on acid leaching extraction of methylmercury into toluene. Methylmercury in the organic phase was determined by electrothermal atomic absorption spectrometry (ETAAS). The methylmercury signal was enhanced and the reproducibility increased by formation of certain complexes and addition of Pd-DDC modifier. The complex of methylmercury with DDC produced the optimum analytical signal in terms of sensitivity and reproducibility compared to complexes with dithizone, cysteine, 1,10-phenanthroline, and diethyldithiocarbamate. Method performance was optimized by modifying parameters such as temperature of mineralization, atomization, and gas flow rate. The limit of detection for methylmercury determination was 0.015 mug g(-1) and the RSD of the whole procedure was 12% for human teeth samples (n=5) and 15.8% for hair samples (n=5). The method's accuracy was investigated by using NIES-13 and by spiking the samples with different amounts of methylmercury. The results were in good agreement with the certified values and the recoveries were 88-95%. PMID:16896613

  9. Preparative divergent flow IEF without carrier ampholytes for separation of complex biological samples.

    PubMed

    Stastna, Miroslava; Slais, Karel

    2010-01-01

    Efficient separation method is a crucial part of the process in which components of highly complex biological sample are identified and characterized. Based on the principles of recently newly established electrophoretic method called divergent flow IEF (DF IEF), we have tested the DF IEF instrument which is able to operate without the use of background carrier ampholytes. We have verified that during separation and focusing of sample consisting of high numbers of proteins (yeast lysate and wheat flour extract), the pH gradient of preparative DF IEF can be created by autofocusing of the sample components themselves without any addition of carrier ampholytes. In DF IEF, the proteins are separated, desalted and concentrated in one step. The fractions of yeast lysate sample, collected at the DF IEF output and subjected to gel IEF, contained the zones of proteins gradually covering the pI values from 3.7 to 8.5. In our experimental arrangement, the highest number of proteins has been found in fractions with pI values around 5.3 as detected by polyacrylamide gel IEF with CBB staining. During DF IEF, the selected protein bands have been concentrated up to 16.8-fold.

  10. An inexpensive and portable microvolumeter for rapid evaluation of biological samples.

    PubMed

    Douglass, John K; Wcislo, William T

    2010-08-01

    We describe an improved microvolumeter (MVM) for rapidly measuring volumes of small biological samples, including live zooplankton, embryos, and small animals and organs. Portability and low cost make this instrument suitable for widespread use, including at remote field sites. Beginning with Archimedes' principle, which states that immersing an arbitrarily shaped sample in a fluid-filled container displaces an equivalent volume, we identified procedures that maximize measurement accuracy and repeatability across a broad range of absolute volumes. Crucial steps include matching the overall configuration to the size of the sample, using reflected light to monitor fluid levels precisely, and accounting for evaporation during measurements. The resulting precision is at least 100 times higher than in previous displacement-based methods. Volumes are obtained much faster than by traditional histological or confocal methods and without shrinkage artifacts due to fixation or dehydration. Calibrations using volume standards confirmed accurate measurements of volumes as small as 0.06 microL. We validated the feasibility of evaluating soft-tissue samples by comparing volumes of freshly dissected ant brains measured with the MVM and by confocal reconstruction.

  11. Validation of the orthogonal tilt reconstruction method with a biological test sample.

    PubMed

    Chandramouli, Preethi; Hernandez-Lopez, Rogelio; Wang, Hong-Wei; Leschziner, Andres E

    2011-07-01

    Electron microscopy of frozen-hydrated samples (cryo-EM) can yield high resolution structures of macromolecular complexes by accurately determining the orientation of large numbers of experimental views of the sample relative to an existing 3D model. The "initial model problem", the challenge of obtaining these orientations ab initio, remains a major bottleneck in determining the structure of novel macromolecules, chiefly those lacking internal symmetry. We previously proposed a method for the generation of initial models--orthogonal tilt reconstruction (OTR)--that bypasses limitations inherent to the other two existing methods, random conical tilt (RCT) and angular reconstitution (AR). Here we present a validation of OTR with a biological test sample whose structure was previously solved by RCT: the complex between the yeast exosome and the subunit Rrp44. We show that, as originally demonstrated with synthetic data, OTR generates initial models that do not exhibit the "missing cone" artifacts associated with RCT and show an isotropic distribution of information when compared with the known structure. This eliminates the need for further user intervention to solve these artifacts and makes OTR ideal for automation and the analysis of heterogeneous samples. With the former in mind, we propose a set of simple quantitative criteria that can be used, in combination, to select from a large set of initial reconstructions a subset that can be used as reliable references for refinement to higher resolution.

  12. An inexpensive and portable microvolumeter for rapid evaluation of biological samples.

    PubMed

    Douglass, John K; Wcislo, William T

    2010-08-01

    We describe an improved microvolumeter (MVM) for rapidly measuring volumes of small biological samples, including live zooplankton, embryos, and small animals and organs. Portability and low cost make this instrument suitable for widespread use, including at remote field sites. Beginning with Archimedes' principle, which states that immersing an arbitrarily shaped sample in a fluid-filled container displaces an equivalent volume, we identified procedures that maximize measurement accuracy and repeatability across a broad range of absolute volumes. Crucial steps include matching the overall configuration to the size of the sample, using reflected light to monitor fluid levels precisely, and accounting for evaporation during measurements. The resulting precision is at least 100 times higher than in previous displacement-based methods. Volumes are obtained much faster than by traditional histological or confocal methods and without shrinkage artifacts due to fixation or dehydration. Calibrations using volume standards confirmed accurate measurements of volumes as small as 0.06 microL. We validated the feasibility of evaluating soft-tissue samples by comparing volumes of freshly dissected ant brains measured with the MVM and by confocal reconstruction. PMID:20701591

  13. An enzyme-based DNA preparation method for application to forensic biological samples and degraded stains.

    PubMed

    Lounsbury, Jenny A; Coult, Natalie; Miranian, Daniel C; Cronk, Stephen M; Haverstick, Doris M; Kinnon, Paul; Saul, David J; Landers, James P

    2012-09-01

    Extraction of DNA from forensic samples typically uses either an organic extraction protocol or solid phase extraction (SPE) and these methods generally involve numerous sample transfer, wash and centrifugation steps. Although SPE has been successfully adapted to the microdevice, it can be problematic because of lengthy load times and uneven packing of the solid phase. A closed-tube enzyme-based DNA preparation method has recently been developed which uses a neutral proteinase to lyse cells and degrade proteins and nucleases [14]. Following a 20 min incubation of the buccal or whole blood sample with this proteinase, DNA is polymerase chain reaction (PCR)-ready. This paper describes the optimization and quantitation of DNA yield using this method, and application to forensic biological samples, including UV- and heat-degraded whole blood samples on cotton or blue denim substrates. Results demonstrate that DNA yield can be increased from 1.42 (±0.21)ng/μL to 7.78 (±1.40)ng/μL by increasing the quantity of enzyme per reaction by 3-fold. Additionally, there is a linear relationship between the amount of starting cellular material added and the concentration of DNA in the solution, thereby allowing DNA yield estimations to be made. In addition, short tandem repeat (STR) profile results obtained using DNA prepared with the enzyme method were comparable to those obtained with a conventional SPE method, resulting in full STR profiles (16 of 16 loci) from liquid samples (buccal swab eluate and whole blood), dried buccal swabs and bloodstains and partial profiles from UV or heat-degraded bloodstains on cotton or blue denim substrates. Finally, the DNA preparation method is shown to be adaptable to glass or poly(methyl methacrylate) (PMMA) microdevices with little impact on STR peak height but providing a 20-fold reduction in incubation time (as little as 60 s), leading to a ≥1 h reduction in DNA preparation time.

  14. Type-II generalized family-wise error rate formulas with application to sample size determination.

    PubMed

    Delorme, Phillipe; de Micheaux, Pierre Lafaye; Liquet, Benoit; Riou, Jérémie

    2016-07-20

    Multiple endpoints are increasingly used in clinical trials. The significance of some of these clinical trials is established if at least r null hypotheses are rejected among m that are simultaneously tested. The usual approach in multiple hypothesis testing is to control the family-wise error rate, which is defined as the probability that at least one type-I error is made. More recently, the q-generalized family-wise error rate has been introduced to control the probability of making at least q false rejections. For procedures controlling this global type-I error rate, we define a type-II r-generalized family-wise error rate, which is directly related to the r-power defined as the probability of rejecting at least r false null hypotheses. We obtain very general power formulas that can be used to compute the sample size for single-step and step-wise procedures. These are implemented in our R package rPowerSampleSize available on the CRAN, making them directly available to end users. Complexities of the formulas are presented to gain insight into computation time issues. Comparison with Monte Carlo strategy is also presented. We compute sample sizes for two clinical trials involving multiple endpoints: one designed to investigate the effectiveness of a drug against acute heart failure and the other for the immunogenicity of a vaccine strategy against pneumococcus. Copyright © 2016 John Wiley & Sons, Ltd. PMID:26914402

  15. Investigation of resins suitable for the preparation of biological sample for 3-D electron microscopy.

    PubMed

    Kizilyaprak, Caroline; Longo, Giovanni; Daraspe, Jean; Humbel, Bruno M

    2015-02-01

    In the last two decades, the third-dimension has become a focus of attention in electron microscopy to better understand the interactions within subcellular compartments. Initially, transmission electron tomography (TEM tomography) was introduced to image the cell volume in semi-thin sections (∼ 500 nm). With the introduction of the focused ion beam scanning electron microscope, a new tool, FIB-SEM tomography, became available to image much larger volumes. During TEM tomography and FIB-SEM tomography, the resin section is exposed to a high electron/ion dose such that the stability of the resin embedded biological sample becomes an important issue. The shrinkage of a resin section in each dimension, especially in depth, is a well-known phenomenon. To ensure the dimensional integrity of the final volume of the cell, it is important to assess the properties of the different resins and determine the formulation which has the best stability in the electron/ion beam. Here, eight different resin formulations were examined. The effects of radiation damage were evaluated after different times of TEM irradiation. To get additional information on mass-loss and the physical properties of the resins (stiffness and adhesion), the topography of the irradiated areas was analysed with atomic force microscopy (AFM). Further, the behaviour of the resins was analysed after ion milling of the surface of the sample with different ion currents. In conclusion, two resin formulations, Hard Plus and the mixture of Durcupan/Epon, emerged that were considerably less affected and reasonably stable in the electron/ion beam and thus suitable for the 3-D investigation of biological samples. PMID:25433274

  16. Overbite and overjet correction in a Class II, division 1 sample treated with Edgewise therapy.

    PubMed

    Hellekant, M; Lagerström, L; Gleerup, A

    1989-05-01

    The purpose of this study was to compare the effect of overjet and overbite correction in non-extraction and extraction therapy in a sample of Class II malocclusions treated with the Edgewise appliance. The subjects were 20 children treated without extraction and 20 children treated with extraction of the four first premolars. During the post-treatment period a relapse of overjet and overbite occurred in both groups. However, there was a beneficial net effect of overjet and overbite correction in both groups with no significant difference between the two groups. The study showed that mandibular intercanine width, space conditions in the lower jaw and mandibular incisor position were important factors in treatment planning.

  17. Analytical performance evaluation of Anyplex II HPV28 and Euroarray HPV for genotyping of cervical samples.

    PubMed

    Latsuzbaia, Ardashel; Tapp, Jessica; Nguyen, Trung; Fischer, Marc; Arbyn, Marc; Weyers, Steven; Mossong, Joël

    2016-07-01

    Analytically accurate human papillomavirus (HPV) genotyping methods are required to assess the impact of HPV vaccination. The aim of this study was to evaluate the analytical performance of Anyplex II HPV28 (Seegene, Korea) and Euroarray HPV (Euroimmun, Germany) genotyping kits, for conducting a future HPV vaccine efficacy monitoring study in Luxembourg. A total number of 150 cervical swabs were collected from women with mean age 31.4 years. Agreements for detecting any HPV between Aptima/Anyplex (88.0%) and Aptima/Euroarray (90.7%) were similar. Agreement of Anyplex/EuroArray with Aptima was higher for Genotypes 16, 18 or 45 than for the other 11 HPVs. The average number of HPV genotypes detected per sample was similar with 2.6 and 2.5, for Anyplex and EuroArray, respectively. In conclusion, Anyplex and Euroarray showed high agreement in general and in particular for detecting genotypes contained in HPV vaccines.

  18. Spectrophotometric determination of Cu(II) in soil and vegetable samples collected from Abraha Atsbeha, Tigray, Ethiopia using heterocyclic thiosemicarbazone.

    PubMed

    Admasu, Daniel; Reddy, Desam Nagarjuna; Mekonnen, Kebede Nigussie

    2016-01-01

    Two selective and sensitive reagents, 2-acetylpyridine thiosemicarbazone (2-APT) and 3-acetylpyridine thiosemicarbazone (3-APT) were used for the spectrophotometric determination of Cu(II). Both reagents gave yellowish Cu(II) complex at a pH range of 8.0-10.0. Beer's law was obeyed for Cu(II)-2-APT and Cu(II)-3-APT in the concentration range of 0.16-1.3 and 0.44-1.05 µg/mL, respectively. The molar absorptivity and of Cu(II)-2-APT and Cu(II)-3-APT were 2.14 × 10(4) at 370 nm, and 6.7 × 10(3) L/mol cm at 350 nm, respectively, while the Sandell's sensitivity were 0.009 and 0.029 µg/cm(2) in that order. The correlation coefficient of the standard curves of Cu(II)-2-APT and Cu(II)-3-APT were 0.999 and 0.998, respectively. The detection limit of the Cu(II)-2-APT and Cu(II)-3-APT methods were 0.053 and 0.147 µg/mL, respectively. The results demonstrated that the procedure is precise (relative standard deviation <2 %, n = 10). The method was tested for Cu(II) determination in soil and vegetable samples. Comparisons of the results with those obtained using a flame atomic absorption spectrophotometer for Cu(II) determination also tested the validity of the method using paired sample t test at the 0.05 level showing a good agreement between them.

  19. Spectrophotometric determination of Cu(II) in soil and vegetable samples collected from Abraha Atsbeha, Tigray, Ethiopia using heterocyclic thiosemicarbazone.

    PubMed

    Admasu, Daniel; Reddy, Desam Nagarjuna; Mekonnen, Kebede Nigussie

    2016-01-01

    Two selective and sensitive reagents, 2-acetylpyridine thiosemicarbazone (2-APT) and 3-acetylpyridine thiosemicarbazone (3-APT) were used for the spectrophotometric determination of Cu(II). Both reagents gave yellowish Cu(II) complex at a pH range of 8.0-10.0. Beer's law was obeyed for Cu(II)-2-APT and Cu(II)-3-APT in the concentration range of 0.16-1.3 and 0.44-1.05 µg/mL, respectively. The molar absorptivity and of Cu(II)-2-APT and Cu(II)-3-APT were 2.14 × 10(4) at 370 nm, and 6.7 × 10(3) L/mol cm at 350 nm, respectively, while the Sandell's sensitivity were 0.009 and 0.029 µg/cm(2) in that order. The correlation coefficient of the standard curves of Cu(II)-2-APT and Cu(II)-3-APT were 0.999 and 0.998, respectively. The detection limit of the Cu(II)-2-APT and Cu(II)-3-APT methods were 0.053 and 0.147 µg/mL, respectively. The results demonstrated that the procedure is precise (relative standard deviation <2 %, n = 10). The method was tested for Cu(II) determination in soil and vegetable samples. Comparisons of the results with those obtained using a flame atomic absorption spectrophotometer for Cu(II) determination also tested the validity of the method using paired sample t test at the 0.05 level showing a good agreement between them. PMID:27512628

  20. Novel optical fiber reflectometric CUPRAC sensor for total antioxidant capacity measurement of food extracts and biological samples.

    PubMed

    Bener, Mustafa; Özyürek, Mustafa; Güçlü, Kubilay; Apak, Reşat

    2013-09-01

    A novel fiber optic sensor was developed for screening the total antioxidant capacity (TAC) based on the use of cupric-neocuproine (Cu(II)-Nc) immobilized onto a Nafion cation-exchange membrane with reflectance spectrometric measurement. The reflectance change associated with the formation of the highly colored Cu(I)-Nc chelate on the membrane as a result of reaction with antioxidants was measured at 530 nm by using a miniature reflectance spectrometer. The calibration graph of trolox (TR) was linear with a slope of 3.40 × 10(3) L mol(-1) mm(-1). The limit of detection (LOD) and limit of quantification (LOQ) for TR in the reflectometric cupric reducing antioxidant capacity (CUPRAC) method were found as 0.53 and 1.76 μM, respectively. The trolox equivalent antioxidant capacities (TEAC) of various antioxidant compounds using the proposed method were comparable to those of the main CUPRAC assay. This assay was validated through linearity, additivity, precision, and recovery. The developed reflectance sensor was used to screen the TAC of some commercial fruit juices and mice tissue homogenates without preliminary treatment. The method is rapid, inexpensive, versatile, and nonlaborious, uses stable reagents on the sensor, and enables the in situ estimation of antioxidant capacity of food extracts and biological samples.

  1. Troubleshooting digital macro photography for image acquisition and the analysis of biological samples.

    PubMed

    Liepinsh, Edgars; Kuka, Janis; Dambrova, Maija

    2013-01-01

    For years, image acquisition and analysis have been an important part of life science experiments to ensure the adequate and reliable presentation of research results. Since the development of digital photography and digital planimetric methods for image analysis approximately 20 years ago, new equipment and technologies have emerged, which have increased the quality of image acquisition and analysis. Different techniques are available to measure the size of stained tissue samples in experimental animal models of disease; however, the most accurate method is digital macro photography with software that is based on planimetric analysis. In this study, we described the methodology for the preparation of infarcted rat heart and brain tissue samples before image acquisition, digital macro photography techniques and planimetric image analysis. These methods are useful in the macro photography of biological samples and subsequent image analysis. In addition, the techniques that are described in this study include the automated analysis of digital photographs to minimize user input and exclude the risk of researcher-generated errors or bias during image analysis.

  2. New photoacoustic cell with diamond window for mid-infrared investigations on biological samples

    NASA Astrophysics Data System (ADS)

    Kottmann, Jonas; Rey, Julien M.; Sigrist, Markus W.

    2012-02-01

    We present a new photoacoustic (PA) cell, which is sealed on the sample side with a 163 μm thick chemical vapor deposition (CVD) diamond window. The investigation of samples containing volatile compounds with an openended PA cell leads to varying conditions in the PA chamber (changing light absorption or relative humidity) and thus causes unstable signals. In contrast the diamond cover ensures stable conditions in the PA chamber and thereby enables sensitive measurements. This is particularly important for the investigation of biological samples with a high water content. Due to the high thermal conductivity of CVD diamond (1800 W/mK) strong PA signals are generated and the broad optical transmission range (250 nm to THz) renders the cell useful for various applications. The performance of the cell is demonstrated by tracking glucose in aqueous keratinocyte solutions with an external-cavity quantum cascade laser (1010-1095 cm-1). These measurements yield a detection limit of 100 mg/dl (SNR=3). Although glucose measurements within the human physiological range (30-500 mg/dl) are feasible, further improvements are needed for non-invasive glucose monitoring of diabetes patients. First in vivo measurements at the human forearm show an additional PA signal induced by blood pulsation at a frequency around 1 Hz and a steadily increasing relative humidity in the PA chamber due to transepidermal water loss if the cell is neither closed with a diamond window nor ventilated with N2.

  3. Molecular dynamics simulations of biological membranes and membrane proteins using enhanced conformational sampling algorithms.

    PubMed

    Mori, Takaharu; Miyashita, Naoyuki; Im, Wonpil; Feig, Michael; Sugita, Yuji

    2016-07-01

    This paper reviews various enhanced conformational sampling methods and explicit/implicit solvent/membrane models, as well as their recent applications to the exploration of the structure and dynamics of membranes and membrane proteins. Molecular dynamics simulations have become an essential tool to investigate biological problems, and their success relies on proper molecular models together with efficient conformational sampling methods. The implicit representation of solvent/membrane environments is reasonable approximation to the explicit all-atom models, considering the balance between computational cost and simulation accuracy. Implicit models can be easily combined with replica-exchange molecular dynamics methods to explore a wider conformational space of a protein. Other molecular models and enhanced conformational sampling methods are also briefly discussed. As application examples, we introduce recent simulation studies of glycophorin A, phospholamban, amyloid precursor protein, and mixed lipid bilayers and discuss the accuracy and efficiency of each simulation model and method. This article is part of a Special Issue entitled: Membrane Proteins edited by J.C. Gumbart and Sergei Noskov.

  4. Mercury speciation and total trace element determination of low-biomass biological samples.

    PubMed

    Taylor, Vivien F; Jackson, Brian P; Chen, Celia Y

    2008-12-01

    Current approaches to mercury speciation and total trace element analysis require separate extraction/digestions of the sample. Ecologically important aquatic organisms--notably primary consumers such as zooplankton, polychaetes and amphipods--usually yield very low biomass for analysis, even with significant compositing of multiple organisms. Individual organisms in the lower aquatic food chains (mussels, snails, oysters, silversides, killifish) can also have very low sample mass, and analysis of whole single organisms is important to metal uptake studies. A method for the determination of both methyl Hg and total heavy metal concentrations (Zn, As, Se, Cd, Hg, Pb) in a single, low-mass sample of aquatic organisms was developed. Samples (2 to 50 mg) were spiked with enriched with (201)MeHg and (199)Hg, then leached in 4 M HNO(3) at 55 degrees C for extraction of MeHg. After 16 h, an aliquot (0.05 mL) was removed to determine mercury species (methyl and inorganic Hg) by isotope dilution gas chromatography inductively coupled plasma mass spectrometry (ICP-MS). The leachate was then acidified to 9 M HNO(3) and digested in a microwave at 150 degrees C for 10 min, and total metal concentrations were determined by collision cell ICP-MS. The method was validated by analyzing five biological certified reference materials. Average percent recoveries for Zn, As, Se, Cd, MeHg, Hg(total) and Pb were 99.9%, 103.5%, 100.4%, 103.3%, 101%, 97.7%, and 97.1%, respectively. The correlation between the sum of MeHg and inorganic Hg from the speciation analysis and total Hg by conventional digestion of the sample was determined for a large sample set of aquatic invertebrates (n = 285). Excellent agreement between the two measured values was achieved. This method is advantageous in situations where sample size is limited, and where correlations between Hg species and other metals are required in the same sample. The method also provides further validation of speciation data, by

  5. Potent and specific inhibition of the biological activity of the type-II transmembrane serine protease matriptase by the cyclic microprotein MCoTI-II.

    PubMed

    Gray, K; Elghadban, S; Thongyoo, P; Owen, K A; Szabo, R; Bugge, T H; Tate, E W; Leatherbarrow, R J; Ellis, V

    2014-08-01

    Matriptase is a type-II transmembrane serine protease involved in epithelial homeostasis in both health and disease, and is implicated in the development and progression of a variety of cancers. Matriptase mediates its biological effects both via as yet undefined substrates and pathways, and also by proteolytic cleavage of a variety of well-defined protein substrates, several of which it shares with the closely-related protease hepsin. Development of targeted therapeutic strategies will require discrimination between these proteases. Here we have investigated cyclic microproteins of the squash Momordica cochinchinensis trypsin-inhibitor family (generated by total chemical synthesis) and found MCoTI-II to be a high-affinity (Ki 9 nM) and highly selective (> 1,000-fold) inhibitor of matriptase. MCoTI-II efficiently inhibited the proteolytic activation of pro-hepatocyte growth factor (HGF) by matriptase but not by hepsin, in both purified and cell-based systems, and inhibited HGF-dependent cell scattering. MCoTI-II also selectively inhibited the invasion of matriptase-expressing prostate cancer cells. Using a model of epithelial cell tight junction assembly, we also found that MCoTI-II could effectively inhibit the re-establishment of tight junctions and epithelial barrier function in MDCK-I cells after disruption, consistent with the role of matriptase in regulating epithelial integrity. Surprisingly, MCoTI-II was unable to inhibit matriptase-dependent proteolytic activation of prostasin, a GPI-anchored serine protease also implicated in epithelial homeostasis. These observations suggest that the unusually high selectivity afforded by MCoTI-II and its biological effectiveness might represent a useful starting point for the development of therapeutic inhibitors, and further highlight the role of matriptase in epithelial maintenance. PMID:24696092

  6. Potent and specific inhibition of the biological activity of the type-II transmembrane serine protease matriptase by the cyclic microprotein MCoTI-II.

    PubMed

    Gray, K; Elghadban, S; Thongyoo, P; Owen, K A; Szabo, R; Bugge, T H; Tate, E W; Leatherbarrow, R J; Ellis, V

    2014-08-01

    Matriptase is a type-II transmembrane serine protease involved in epithelial homeostasis in both health and disease, and is implicated in the development and progression of a variety of cancers. Matriptase mediates its biological effects both via as yet undefined substrates and pathways, and also by proteolytic cleavage of a variety of well-defined protein substrates, several of which it shares with the closely-related protease hepsin. Development of targeted therapeutic strategies will require discrimination between these proteases. Here we have investigated cyclic microproteins of the squash Momordica cochinchinensis trypsin-inhibitor family (generated by total chemical synthesis) and found MCoTI-II to be a high-affinity (Ki 9 nM) and highly selective (> 1,000-fold) inhibitor of matriptase. MCoTI-II efficiently inhibited the proteolytic activation of pro-hepatocyte growth factor (HGF) by matriptase but not by hepsin, in both purified and cell-based systems, and inhibited HGF-dependent cell scattering. MCoTI-II also selectively inhibited the invasion of matriptase-expressing prostate cancer cells. Using a model of epithelial cell tight junction assembly, we also found that MCoTI-II could effectively inhibit the re-establishment of tight junctions and epithelial barrier function in MDCK-I cells after disruption, consistent with the role of matriptase in regulating epithelial integrity. Surprisingly, MCoTI-II was unable to inhibit matriptase-dependent proteolytic activation of prostasin, a GPI-anchored serine protease also implicated in epithelial homeostasis. These observations suggest that the unusually high selectivity afforded by MCoTI-II and its biological effectiveness might represent a useful starting point for the development of therapeutic inhibitors, and further highlight the role of matriptase in epithelial maintenance.

  7. Characterisation of radiation field for irradiation of biological samples at nuclear reactor-comparison of twin detector and recombination methods.

    PubMed

    Golnik, N; Gryziński, M A; Kowalska, M; Meronka, K; Tulik, P

    2014-10-01

    Central Laboratory for Radiological Protection is involved in achieving scientific project on biological dosimetry. The project includes irradiation of blood samples in radiation fields of nuclear reactor. A simple facility for irradiation of biological samples has been prepared at horizontal channel of the nuclear reactor MARIA in NCBJ in Poland. The radiation field, composed mainly of gamma radiation and thermal neutrons, has been characterised in terms of tissue kerma using twin-detector technique and recombination chambers.

  8. RNA-seq of human reference RNA samples using a thermostable group II intron reverse transcriptase.

    PubMed

    Nottingham, Ryan M; Wu, Douglas C; Qin, Yidan; Yao, Jun; Hunicke-Smith, Scott; Lambowitz, Alan M

    2016-04-01

    Next-generation RNA sequencing (RNA-seq) has revolutionized our ability to analyze transcriptomes. Current RNA-seq methods are highly reproducible, but each has biases resulting from different modes of RNA sample preparation, reverse transcription, and adapter addition, leading to variability between methods. Moreover, the transcriptome cannot be profiled comprehensively because highly structured RNAs, such as tRNAs and snoRNAs, are refractory to conventional RNA-seq methods. Recently, we developed a new method for strand-specific RNA-seq using thermostable group II intron reverse transcriptases (TGIRTs). TGIRT enzymes have higher processivity and fidelity than conventional retroviral reverse transcriptases plus a novel template-switching activity that enables RNA-seq adapter addition during cDNA synthesis without using RNA ligase. Here, we obtained TGIRT-seq data sets for well-characterized human RNA reference samples and compared them to previous data sets obtained for these RNAs by the Illumina TruSeq v2 and v3 methods. We find that TGIRT-seq recapitulates the relative abundance of human transcripts and RNA spike-ins in ribo-depleted, fragmented RNA samples comparably to non-strand-specific TruSeq v2 and better than strand-specific TruSeq v3. Moreover, TGIRT-seq is more strand specific than TruSeq v3 and eliminates sampling biases from random hexamer priming, which are inherent to TruSeq. The TGIRT-seq data sets also show more uniform 5' to 3' gene coverage and identify more splice junctions, particularly near the 5' ends of mRNAs, than do the TruSeq data sets. Finally, TGIRT-seq enables the simultaneous profiling of mRNAs and lncRNAs in the same RNA-seq experiment as structured small ncRNAs, including tRNAs, which are essentially absent with TruSeq.

  9. METHODS FOR USING 3-D ULTRASOUND SPECKLE TRACKING IN BIAXIAL MECHANICAL TESTING OF BIOLOGICAL TISSUE SAMPLES

    PubMed Central

    Yap, Choon Hwai; Park, Dae Woo; Dutta, Debaditya; Simon, Marc; Kim, Kang

    2014-01-01

    Being multilayered and anisotropic, biological tissues such as cardiac and arterial walls are structurally complex, making full assessment and understanding of their mechanical behavior challenging. Current standard mechanical testing uses surface markers to track tissue deformations and does not provide deformation data below the surface. In the study described here, we found that combining mechanical testing with 3-D ultrasound speckle tracking could overcome this limitation. Rat myocardium was tested with a biaxial tester and was concurrently scanned with high-frequency ultrasound in three dimensions. The strain energy function was computed from stresses and strains using an iterative non-linear curve-fitting algorithm. Because the strain energy function consists of terms for the base matrix and for embedded fibers, spatially varying fiber orientation was also computed by curve fitting. Using finite-element simulations, we first validated the accuracy of the non-linear curve-fitting algorithm. Next, we compared experimentally measured rat myocardium strain energy function values with those in the literature and found a matching order of magnitude. Finally, we retained samples after the experiments for fiber orientation quantification using histology and found that the results satisfactorily matched those computed in the experiments. We conclude that 3-D ultrasound speckle tracking can be a useful addition to traditional mechanical testing of biological tissues and may provide the benefit of enabling fiber orientation computation. PMID:25616585

  10. Determination of steroid hormones in biological and environmental samples using green microextraction techniques: an overview.

    PubMed

    Aufartová, Jana; Mahugo-Santana, Cristina; Sosa-Ferrera, Zoraida; Santana-Rodríguez, José Juan; Nováková, Lucie; Solich, Petr

    2011-10-17

    Residues of steroid hormones have become a cause for concern because they can affect the biological activity of non-target organisms. Steroid hormones are a potential risk for wildlife and humans through the consumption of contaminated food or water. Their determination requires extraction and clean-up steps, prior to detection, to reach low concentration levels. In recent years, a great effort has been made to develop new analytical methodologies, such as microextraction techniques, that reduce environmental pollution. Researchers have modified old methods to incorporate procedures that use less-hazardous chemicals or that use smaller amounts of them. They are able to do direct analysis using miniaturised equipment and reduced amounts of solvents and wastes. These accomplishments are the main objectives of green analytical chemistry. In this overview, we focus on microextraction techniques for the determination of steroid hormones in biological (e.g., human urine, human serum, fish, shrimp and prawn tissue and milk) and environmental (e.g., wastewaters, surface waters, tap waters, river waters, sewage sludges, marine sediments and river sediments) samples. We comment on the most recent applications in sorptive-microextraction modes, such as solid phase microextraction (SPME) with molecularly imprinted polymers (MIPs), in-tube solid-phase microextraction (IT-SPME), stir-bar sorptive extraction (SBSE) and microextraction in packed sorbent (MEPS). We also describe liquid-phase microextraction (LPME) approaches reported in the literature that are applied to the determination of steroid hormones.

  11. Chelation ion chromatography as a method for trace elemental analysis in complex environmental and biological samples

    SciTech Connect

    Siriraks, A.; Kingston, H.M. ); Riviello, J.M. )

    1990-06-01

    The development and evaluation of a new method for the determination of trace transition and rare-earth elements based on the combination of chelation and ion chromatography are described. The new method, chelation ion chromatography (Chelation IC), uses a chelating column to concentrate and separate transition and rare-earth elements from the common alkali and alkaline-earth metals, as well as other matrix components, prior to analysis by ion chromatography. The sample fraction from the chelating column contains only the concentrated analyte ions, thus eliminating interfering matrix components from complex matrices such as seawater and digested biological, botanical, and geological materials. This combination of chelation and ion chromatography provides a technique that makes possible the determination of trace elements in complex matrices that have proven to be difficult or impossible to analyze by ion chromatography or conventional atomic spectroscopy techniques.

  12. Biological sample preparation and {sup 41}Ca AMS measurement at LLNL

    SciTech Connect

    Freeman, S.P.H.T.; Southon, J.R.; Bench, G.S.; McAninch, J.E.; Serfass, R.E.; Fang, Y.; King, J.C.; Woodhouse, L.R.

    1994-10-10

    Calcium metabolism in biology may be better understood by the use of {sup 41}Ca labels, although detection by accelerator mass spectrometry (AMS) is required. Methodologies for preparation of urine samples and subsequent AMS measurement were investigated. Novel attempts at preparing CaH{sub 2} were unsuccessful, but CaF{sub 2} of sufficient purity could be produced by precipitation of calcium from urine as oxalate, followed by separation of calcium by cation exchange chromatography and washing the CaF{sub 2} precipitate. The presence of some remaining impurities could be compensated for by selecting the appropriate accelerated ion charge state for AMS. The use of projectile x rays for isobar discrimination was explored as an alternative to the conventional dE/dx device.

  13. Magnetically responsive polycaprolactone nanoparticles for progesterone screening in biological and environmental samples using gas chromatography.

    PubMed

    Es'haghi, Zarrin; Nezhadali, Azizollah; Khatibi, Aram-Dokht

    2016-08-01

    A new Fe3O4/poly(є-caprolactone) (PCL) magnetite nanocomposite was fabricated and used as a sorbent for magnetically mediated PCL microspheres solid-phase extraction (MM-PCL-SPE) followed by gas chromatography-flame ionization detection (GC-FID) for monitoring of progesterone (PGN) hormone in biological and environmental matrices, namely blood serum, tap water, urine, and hospital wastewater. The nanomagnetite core of the sorbent was synthesized by a co-precipitation method. Magnetic nanoparticles (MNPs) were then microencapsulated with PCL microspheres using emulsion polymerization. The nanocomposite was characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The magnetite sorbent can be effectively dispersed in aqueous solution and attracted to an external magnetic field. The MM-PCL-SPE process for PGN assay involved (a) dispersion of the sorbent in the donor phase aqueous solution with sonication, (b) exposure to a magnetic field to collect sorbent that had adsorbed the analyte, and (c) solvent desorption of extracted PGN for GC-FID analysis. The work demonstrates the usefulness of MM-PCL-SPE in the rapid and sensitive monitoring of trace amounts of PGN in real samples. The limit of detection (LOD) and limit of quantification (LOQ) were 1.00 and 3.30 ng/mL, respectively. The relative recoveries in real samples were adequate. Linearity was observed over a wide range of 2.2-10,000.0 ng/mL in aqueous media and urine and 0.01-70.0 μg/mL in blood serum. Graphical Abstract In this research new Fe3O4/poly(є-caprolactone) (PCL) magnetite microspheres were developed as an efficient sorbent for solid-phase extraction of progesterone hormone in biological and environmental matrices. PMID:27299775

  14. Burnup calculations and chemical analysis of irradiated fuel samples studied in LWR-PROTEUS phase II

    SciTech Connect

    Grimm, P.; Guenther-Leopold, I.; Berger, H. D.

    2006-07-01

    The isotopic compositions of 5 UO{sub 2} samples irradiated in a Swiss PWR power plant, which were investigated in the LWR-PROTEUS Phase II programme, were calculated using the CASMO-4 and BOXER assembly codes. The burnups of the samples range from 50 to 90 MWd/kg. The results for a large number of actinide and fission product nuclides were compared to those of chemical analyses performed using a combination of chromatographic separation and mass spectrometry. A good agreement of calculated and measured concentrations is found for many of the nuclides investigated with both codes. The concentrations of the Pu isotopes are mostly predicted within {+-}10%, the two codes giving quite different results, except for {sup 242}Pu. Relatively significant deviations are found for some isotopes of Cs and Sm, and large discrepancies are observed for Eu and Gd. The overall quality of the predictions by the two codes is comparable, and the deviations from the experimental data do not generally increase with burnup. (authors)

  15. Nested sampling for parameter inference in systems biology: application to an exemplar circadian model

    PubMed Central

    2013-01-01

    Background Model selection and parameter inference are complex problems that have yet to be fully addressed in systems biology. In contrast with parameter optimisation, parameter inference computes both the parameter means and their standard deviations (or full posterior distributions), thus yielding important information on the extent to which the data and the model topology constrain the inferred parameter values. Results We report on the application of nested sampling, a statistical approach to computing the Bayesian evidence Z, to the inference of parameters, and the estimation of log Z in an established model of circadian rhythms. A ten-fold difference in the coefficient of variation between degradation and transcription parameters is demonstrated. We further show that the uncertainty remaining in the parameter values is reduced by the analysis of increasing numbers of circadian cycles of data, up to 4 cycles, but is unaffected by sampling the data more frequently. Novel algorithms for calculating the likelihood of a model, and a characterisation of the performance of the nested sampling algorithm are also reported. The methods we develop considerably improve the computational efficiency of the likelihood calculation, and of the exploratory step within nested sampling. Conclusions We have demonstrated in an exemplar circadian model that the estimates of posterior parameter densities (as summarised by parameter means and standard deviations) are influenced predominately by the length of the time series, becoming more narrowly constrained as the number of circadian cycles considered increases. We have also shown the utility of the coefficient of variation for discriminating between highly-constrained and less-well constrained parameters. PMID:23899119

  16. Microscopic linear liquid streams in vacuum: Injection of solvated biological samples into X-ray free electron lasers

    SciTech Connect

    Doak, R. B.; DePonte, D. P.; Nelson, G.; Camacho-Alanis, F.; Ros, A.; Spence, J. C. H.; Weierstall, U.

    2012-11-27

    Microscopic linear liquid free-streams offer a means of gently delivering biological samples into a probe beam in vacuum while maintaining the sample species in a fully solvated state. By employing gas dynamic forces to form the microscopic liquid stream (as opposed to a conventional solid-walled convergent nozzle), liquid free-streams down to 300 nm diameter have been generated. Such 'Gas Dynamic Virtual Nozzles' (GDVN) are ideally suited to injecting complex biological species into an X-ray Free Electron Laser (XFEL) to determine the structure of the biological species via Serial Femtosecond Crystallography (SFX). GDVN injector technology developed for this purpose is described.

  17. Characterization of α-Synuclein Multimer Stoichiometry in Complex Biological Samples by Electrophoresis

    PubMed Central

    2016-01-01

    The aberrant aggregation of α-synuclein in the brain is a hallmark of Parkinson’s disease (PD). In vivo soluble α-synuclein occurs as a monomer and several multimers, the latter of which may be important for the biological function of α-synuclein. Currently, there is a lack of reproducible methods to compare α-synuclein multimer abundance between complex biological samples. Here we developed a method, termed “multimer-PAGE,” that combines in-gel chemical cross-linking with several common electrophoretic techniques to measure the stoichiometry of soluble α-synuclein multimers in brain tissue lysates. Results show that soluble α-synuclein from the rat brain exists as several high molecular weight species of approximately 56 kDa (αS56), 80 kDa (αS80), and 100 kDa (αS100) that comigrate with endogenous lipids, detergents, and/or micelles during blue native gel electrophoresis (BN-PAGE). Co-extraction of endogenous lipids with α-synuclein was essential for the detection of soluble α-synuclein multimers. Homogenization of brain tissue in small buffer volumes (>50 mg tissue per 1 mL buffer) increased relative lipid extraction and subsequently resulted in abundant soluble multimer detection via multimer-PAGE. α-Synuclein multimers captured by directly cross-linking soluble lysates resembled those observed following multimer-PAGE. The ratio of multimer (αS80) to monomer (αS17) increased linearly with protein input into multimer-PAGE, suggesting to some extent, multimers were also formed during electrophoresis. Overall, soluble α-synuclein maintains lipid interactions following tissue disruption and readily forms multimers when this lipid–protein complex is preserved. Once the multimer-PAGE technique was validated, relative stoichiometric comparisons could be conducted simultaneously between 14 biological samples. Multimer-PAGE provides a simple inexpensive biochemical technique to study the molecular factors influencing α-synuclein multimerization

  18. Analyzing free zinc(II) ion concentrations in cell biology with fluorescent chelating molecules.

    PubMed

    Maret, Wolfgang

    2015-02-01

    Essential metal ions are tightly controlled in biological systems. An understanding of metal metabolism and homeostasis is being developed from quantitative information of the sizes, concentrations, and dynamics of cellular and subcellular metal ion pools. In the case of human zinc metabolism, minimally 24 proteins of two zinc transporter families and a dozen metallothioneins participate in cellular uptake, extrusion, and re-distribution among cellular compartments. Significantly, zinc(ii) ions are now considered signaling ions in intra- and intercellular communication. Such functions require transients of free zinc ions. It is experimentally quite challenging to distinguish zinc that is protein-bound from zinc that is not bound to proteins. Measurement of total zinc is relatively straightforward with analytical techniques such as atomic absorption/emission spectroscopy or inductively coupled plasma mass spectrometry. Total zinc concentrations of human cells are 200-300 μM. In contrast, the pool of non-protein bound zinc is mostly examined with fluorescence microscopy/spectroscopy. There are two widely applied fluorescence approaches, one employing low molecular weight chelating agents ("probes") and the other metal-binding proteins ("sensors"). The protein sensors, such as the CALWY, Zap/ZifCY, and carbonic anhydrase-based sensors, can be genetically encoded and have certain advantages in terms of controlling intracellular concentration, localization, and calibration. When employed correctly, both probes and sensors can establish qualitative differences in free zinc ion concentrations. However, when quantitative information is sought, the assumptions underlying the applications of probes and sensors must be carefully examined and even then measured pools of free zinc ions remain methodologically defined. A consensus is building that the steady-state free zinc ion concentrations in the cytosol are in the picomolar range but there is no consensus on their

  19. 3D surface scan of biological samples with a Push-broom Imaging Spectrometer

    NASA Astrophysics Data System (ADS)

    Yao, Haibo; Kincaid, Russell; Hruska, Zuzana; Brown, Robert L.; Bhatnagar, Deepak; Cleveland, Thomas E.

    2013-08-01

    The food industry is always on the lookout for sensing technologies for rapid and nondestructive inspection of food products. Hyperspectral imaging technology integrates both imaging and spectroscopy into unique imaging sensors. Its application for food safety and quality inspection has made significant progress in recent years. Specifically, hyperspectral imaging has shown its potential for surface contamination detection in many food related applications. Most existing hyperspectral imaging systems use pushbroom scanning which is generally used for flat surface inspection. In some applications it is desirable to be able to acquire hyperspectral images on circular objects such as corn ears, apples, and cucumbers. Past research describes inspection systems that examine all surfaces of individual objects. Most of these systems did not employ hyperspectral imaging. These systems typically utilized a roller to rotate an object, such as an apple. During apple rotation, the camera took multiple images in order to cover the complete surface of the apple. The acquired image data lacked the spectral component present in a hyperspectral image. This paper discusses the development of a hyperspectral imaging system for a 3-D surface scan of biological samples. The new instrument is based on a pushbroom hyperspectral line scanner using a rotational stage to turn the sample. The system is suitable for whole surface hyperspectral imaging of circular objects. In addition to its value to the food industry, the system could be useful for other applications involving 3-D surface inspection.

  20. Biological Monitoring of Human Exposure to Neonicotinoids Using Urine Samples, and Neonicotinoid Excretion Kinetics

    PubMed Central

    Harada, Kouji H.; Tanaka, Keiko; Sakamoto, Hiroko; Imanaka, Mie; Niisoe, Tamon; Hitomi, Toshiaki; Kobayashi, Hatasu; Okuda, Hiroko; Inoue, Sumiko; Kusakawa, Koichi; Oshima, Masayo; Watanabe, Kiyohiko; Yasojima, Makoto; Takasuga, Takumi; Koizumi, Akio

    2016-01-01

    Background Neonicotinoids, which are novel pesticides, have entered into usage around the world because they are selectively toxic to arthropods and relatively non-toxic to vertebrates. It has been suggested that several neonicotinoids cause neurodevelopmental toxicity in mammals. The aim was to establish the relationship between oral intake and urinary excretion of neonicotinoids by humans to facilitate biological monitoring, and to estimate dietary neonicotinoid intakes by Japanese adults. Methodology/Principal Findings Deuterium-labeled neonicotinoid (acetamiprid, clothianidin, dinotefuran, and imidacloprid) microdoses were orally ingested by nine healthy adults, and 24 h pooled urine samples were collected for 4 consecutive days after dosing. The excretion kinetics were modeled using one- and two-compartment models, then validated in a non-deuterium-labeled neonicotinoid microdose study involving 12 healthy adults. Increased urinary concentrations of labeled neonicotinoids were observed after dosing. Clothianidin was recovered unchanged within 3 days, and most dinotefuran was recovered unchanged within 1 day. Around 10% of the imidacloprid dose was excreted unchanged. Most of the acetamiprid was metabolized to desmethyl-acetamiprid. Spot urine samples from 373 Japanese adults were analyzed for neonicotinoids, and daily intakes were estimated. The estimated average daily intake of these neonicotinoids was 0.53–3.66 μg/day. The highest intake of any of the neonicotinoids in the study population was 64.5 μg/day for dinotefuran, and this was <1% of the acceptable daily intake. PMID:26731104

  1. Methods of biological fluids sample preparation - biogenic amines, methylxanthines, water-soluble vitamins.

    PubMed

    Płonka, Joanna

    2015-01-01

    In recent years demands on the amount of information that can be obtained from the analysis of a single sample have increased. For time and economic reasons it is necessary to examine at the same time larger number of compounds, and compounds from different groups. This can best be seen in such areas as clinical analysis. In many diseases, the best results for patients are obtained when treatment fits the individual characteristics of the patient. Dosage monitoring is important at the beginning of therapy and in the full process of treatment. In the treatment of many diseases biogenic amines (dopamine, serotonin) and methylxanthines (theophylline, theobromine, caffeine) play an important role. They are used as drugs separately or in combination with others to support and strengthen the action of other drugs - for example, the combination of caffeine and paracetamol. Vitamin supplementation may be also an integral part of the treatment process. Specification of complete sample preparation parameters for extraction of the above compounds from biological matrices has been reviewed. Particular attention was given to the preparation stage and extraction methods. This review provides universal guidance on establishing a common procedures across laboratories to facilitate the preparation and analysis of all discussed compounds. PMID:25381720

  2. The Sorcerer II Global Ocean Sampling Expedition: Northwest Atlantic through Eastern Tropical Pacific

    PubMed Central

    Rusch, Douglas B; Halpern, Aaron L; Sutton, Granger; Heidelberg, Karla B; Williamson, Shannon; Yooseph, Shibu; Wu, Dongying; Eisen, Jonathan A; Hoffman, Jeff M; Remington, Karin; Beeson, Karen; Tran, Bao; Smith, Hamilton; Baden-Tillson, Holly; Stewart, Clare; Thorpe, Joyce; Freeman, Jason; Andrews-Pfannkoch, Cynthia; Venter, Joseph E; Li, Kelvin; Kravitz, Saul; Heidelberg, John F; Utterback, Terry; Rogers, Yu-Hui; Falcón, Luisa I; Souza, Valeria; Bonilla-Rosso, Germán; Eguiarte, Luis E; Karl, David M; Sathyendranath, Shubha; Platt, Trevor; Bermingham, Eldredge; Gallardo, Victor; Tamayo-Castillo, Giselle; Ferrari, Michael R; Strausberg, Robert L; Nealson, Kenneth; Friedman, Robert; Frazier, Marvin; Venter, J. Craig

    2007-01-01

    The world's oceans contain a complex mixture of micro-organisms that are for the most part, uncharacterized both genetically and biochemically. We report here a metagenomic study of the marine planktonic microbiota in which surface (mostly marine) water samples were analyzed as part of the Sorcerer II Global Ocean Sampling expedition. These samples, collected across a several-thousand km transect from the North Atlantic through the Panama Canal and ending in the South Pacific yielded an extensive dataset consisting of 7.7 million sequencing reads (6.3 billion bp). Though a few major microbial clades dominate the planktonic marine niche, the dataset contains great diversity with 85% of the assembled sequence and 57% of the unassembled data being unique at a 98% sequence identity cutoff. Using the metadata associated with each sample and sequencing library, we developed new comparative genomic and assembly methods. One comparative genomic method, termed “fragment recruitment,” addressed questions of genome structure, evolution, and taxonomic or phylogenetic diversity, as well as the biochemical diversity of genes and gene families. A second method, termed “extreme assembly,” made possible the assembly and reconstruction of large segments of abundant but clearly nonclonal organisms. Within all abundant populations analyzed, we found extensive intra-ribotype diversity in several forms: (1) extensive sequence variation within orthologous regions throughout a given genome; despite coverage of individual ribotypes approaching 500-fold, most individual sequencing reads are unique; (2) numerous changes in gene content some with direct adaptive implications; and (3) hypervariable genomic islands that are too variable to assemble. The intra-ribotype diversity is organized into genetically isolated populations that have overlapping but independent distributions, implying distinct environmental preference. We present novel methods for measuring the genomic similarity

  3. The Sorcerer II Global Ocean Sampling expedition: northwest Atlantic through eastern tropical Pacific.

    PubMed

    Rusch, Douglas B; Halpern, Aaron L; Sutton, Granger; Heidelberg, Karla B; Williamson, Shannon; Yooseph, Shibu; Wu, Dongying; Eisen, Jonathan A; Hoffman, Jeff M; Remington, Karin; Beeson, Karen; Tran, Bao; Smith, Hamilton; Baden-Tillson, Holly; Stewart, Clare; Thorpe, Joyce; Freeman, Jason; Andrews-Pfannkoch, Cynthia; Venter, Joseph E; Li, Kelvin; Kravitz, Saul; Heidelberg, John F; Utterback, Terry; Rogers, Yu-Hui; Falcón, Luisa I; Souza, Valeria; Bonilla-Rosso, Germán; Eguiarte, Luis E; Karl, David M; Sathyendranath, Shubha; Platt, Trevor; Bermingham, Eldredge; Gallardo, Victor; Tamayo-Castillo, Giselle; Ferrari, Michael R; Strausberg, Robert L; Nealson, Kenneth; Friedman, Robert; Frazier, Marvin; Venter, J Craig

    2007-03-01

    The world's oceans contain a complex mixture of micro-organisms that are for the most part, uncharacterized both genetically and biochemically. We report here a metagenomic study of the marine planktonic microbiota in which surface (mostly marine) water samples were analyzed as part of the Sorcerer II Global Ocean Sampling expedition. These samples, collected across a several-thousand km transect from the North Atlantic through the Panama Canal and ending in the South Pacific yielded an extensive dataset consisting of 7.7 million sequencing reads (6.3 billion bp). Though a few major microbial clades dominate the planktonic marine niche, the dataset contains great diversity with 85% of the assembled sequence and 57% of the unassembled data being unique at a 98% sequence identity cutoff. Using the metadata associated with each sample and sequencing library, we developed new comparative genomic and assembly methods. One comparative genomic method, termed "fragment recruitment," addressed questions of genome structure, evolution, and taxonomic or phylogenetic diversity, as well as the biochemical diversity of genes and gene families. A second method, termed "extreme assembly," made possible the assembly and reconstruction of large segments of abundant but clearly nonclonal organisms. Within all abundant populations analyzed, we found extensive intra-ribotype diversity in several forms: (1) extensive sequence variation within orthologous regions throughout a given genome; despite coverage of individual ribotypes approaching 500-fold, most individual sequencing reads are unique; (2) numerous changes in gene content some with direct adaptive implications; and (3) hypervariable genomic islands that are too variable to assemble. The intra-ribotype diversity is organized into genetically isolated populations that have overlapping but independent distributions, implying distinct environmental preference. We present novel methods for measuring the genomic similarity between

  4. Biological Parametric Mapping Accounting for Random Regressors with Regression Calibration and Model II Regression

    PubMed Central

    Yang, Xue; Lauzon, Carolyn B.; Crainiceanu, Ciprian; Caffo, Brian; Resnick, Susan M.; Landman, Bennett A.

    2012-01-01

    Massively univariate regression and inference in the form of statistical parametric mapping have transformed the way in which multi-dimensional imaging data are studied. In functional and structural neuroimaging, the de facto standard “design matrix”-based general linear regression model and its multi-level cousins have enabled investigation of the biological basis of the human brain. With modern study designs, it is possible to acquire multi-modal three-dimensional assessments of the same individuals — e.g., structural, functional and quantitative magnetic resonance imaging, alongside functional and ligand binding maps with positron emission tomography. Largely, current statistical methods in the imaging community assume that the regressors are non-random. For more realistic multi-parametric assessment (e.g., voxel-wise modeling), distributional consideration of all observations is appropriate. Herein, we discuss two unified regression and inference approaches, model II regression and regression calibration, for use in massively univariate inference with imaging data. These methods use the design matrix paradigm and account for both random and non-random imaging regressors. We characterize these methods in simulation and illustrate their use on an empirical dataset. Both methods have been made readily available as a toolbox plug-in for the SPM software. PMID:22609453

  5. Genotyping of samples from German patients with ocular, cerebral and systemic toxoplasmosis reveals a predominance of Toxoplasma gondii type II.

    PubMed

    Herrmann, Daland C; Maksimov, Pavlo; Hotop, Andrea; Groß, Uwe; Däubener, Walter; Liesenfeld, Oliver; Pleyer, Uwe; Conraths, Franz J; Schares, Gereon

    2014-10-01

    Toxoplasmosis is an important zoonosis transmitted from animals to humans world-wide. In order to determine Toxoplasma gondii genotypes in individuals living in Germany and to compare findings with those in animals, we analysed nine independent and unlinked genetic markers (nSAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico) by PCR-RFLP in 83 archived T. gondii-positive DNA samples from patients with ocular toxoplasmosis (n=35), toxoplasmic encephalitis (n=32), systemic toxoplasmosis after bone-marrow transplantation (n=15) and congenital toxoplasmosis (n=1). In 46 of these 83 samples the presence of T. gondii DNA was confirmed by conventional end-point PCR. Among these, 17 T. gondii-positive samples were typed at all nine loci. The majority (15/17, 88.2%) of these samples were of T. gondii type II (i.e., including both, the Apico type II and Apico type I variants). In addition, in one sample a T. gondii type II/type III allele combination and in another sample a T. gondii genotype displaying type III alleles at all markers was observed. In the remaining 11 samples, in which T. gondii could only be partially typed, exclusively type II (n=10) or type III (n=1) alleles were observed. Results of the present study suggest that the majority of patients in Germany are infected with type II T. gondii regardless of the clinical manifestation of toxoplasmosis. This finding is in accord with the predominance of type II T. gondii in oocysts isolated from cats and in tissues of other intermediate hosts in Germany.

  6. Pooling of samples for seroepidemiological surveillance of human T-cell lymphotropic virus types I and II.

    PubMed

    Andersson, S; Gessain, A; Taylor, G P

    2001-10-30

    We evaluated a straight forward pooling strategy for antibody screening of HTLV-I/II, using panels of sera from various parts of the world including a total of 43 HTLV-I and 54 HTLV-II positive specimens. Four antibody screening assays were included in the evaluation: the HTLV-I/II GE 80/81 (Murex Diagnostics), the HTLV-I/HTLV-II Ab Capture ELISA (Ortho Diagnostics), the HTLV-I/II ELISA 3.0 (Genelabs Diagnostics) and the Serodia HTLV-I (Fujirebio). The Murex and Ortho assays represent a new generation of HTLV screening tests with a sandwich format incorporating both HTLV-I and HTLV-II synthetic and/or recombinant peptide antigens. The Genelabs assay is an indirect ELISA with recombinant HTLV-I and -II antigens and Serodia is a particle agglutination assay with HTLV-I whole viral lysate. Each HTLV-positive sample was included in pools of 1/1 up to 1/16, in two-fold steps made in normal HTLV-negative blood donor serum from one up to nine donors. For HTLV-I, with the exception of one false negative sample in dilution 1/16 with Genelabs ELISA, all assays were positive at all dilutions. The Murex assay had absorbance values at maximum levels for all samples at all dilutions. The other assays had gradually decreasing absorbance values although clearly above cut-off. For HTLV-II, the Murex assay correctly detected all samples to dilution 1/16 despite gradually decreasing signals. The Serodia assay had 100% sensitivity to dilution 1/4 while at 1/8 and 1/16 it decreased 82 and 80%, respectively. The Genelabs ELISA had gradually decreasing sensitivity for HTLV-II from 98 (1/1) to 33% (1/16) while the Ortho assay detected all specimens at all dilutions in a limited set of samples tested. Taken together, this evaluation has shown that pooling of samples may be an appropriate strategy for serosurveillance of HTLV. It is, however, crucial to limit the number of samples and to choose assays that allow the dilution caused by the pooling. Using the best performing assays in this

  7. Multispectral diode laser based shifted excitation Raman difference spectroscopy for biological sample identification

    NASA Astrophysics Data System (ADS)

    Sowoidnich, Kay; Kronfeldt, Heinz-Detlef

    2012-06-01

    Raman spectroscopy is a well established analytical method with applications in many areas, e.g. analysis of biological samples. To overcome the problem of an undesired fluorescence background masking the Raman signals we present a multi-spectral approach using shifted excitation Raman difference spectroscopy (SERDS). For our investigations we applied microsystem diode lasers which realize two slightly shifted excitation wavelengths required to perform SERDS at 488 nm, 671 nm, and 785 nm. The emission at 488 nm with an optical power of up to 30 mW and a spectral shift of 0.3 nm (12 cm-1) is realized by frequency doubling of a 976 nm distributed feedback (DFB) diode laser. The 671 nm laser diode contains two separate laser cavities (spectral shift: 0.7 nm (13 cm-1)) each incorporating a volume Bragg grating as frequency selective element. In that case, optical powers up to 50 mW can be obtained. For investigations at 785 nm we used a DFB laser with a maximum optical power of 110 mW and a spectral shift of 0.5 nm (7 cm-1). Meat, fat tissue, connective tissue and bones from pork and beef were used as test samples to demonstrate the effective background removal using SERDS. For all three wavelengths integration times of only 5 - 10 seconds were necessary showing the possibility of SERDS for rapid sample identification. A comparison with conventional Raman spectra is given pointing out the improvement of spectral quality. The applicability of SERDS for other analytical applications, e.g. medical diagnosis will be discussed.

  8. Stable-isotope GC-MS/MS determination of aminoethylcysteine ketimine decarboxylated dimer in biological samples

    PubMed Central

    Tsikas, Dimitrios; Evans, Christopher E.; Denton, Travis T.; Mitschke, Anja; Gutzki, Frank-Mathias; Pinto, John T.; Khomenko, Tetyana; Szabo, Sandor; Cooper, Arthur J.L.

    2012-01-01

    Aminoethylcysteine ketimine decarboxylated dimer [AECK-DD; systematic name: 1,2–3,4–5,6–7,8-octahydro-1,8a-diaza-4,6-dithiafluoren-9(8aH)-one] is a previously described metabolite of cysteamine that has been reported to be present in mammalian brain, urine, plasma, cells in culture and vegetables, and to possess potent anti-oxidative properties. Here, we describe a stable-isotope GC-MS/MS method for specific and sensitive determination of AECK-DD in biological samples. 13C2-AECK-DD was synthesized and used as the internal standard. Derivatization was carried out by N-pentafluorobenzylation with pentafluorobenzyl bromide in acetonitrile. Quantification was performed by selected-reaction monitoring of the mass transitions m/z 328 to m/z 268 for AECK-DD and m/z 330 to m/z 270 for 13C2-AECK-DD in the electron-capture negative-ion chemical ionization mode. The procedure was systematically validated for human plasma and urine samples. AECK-DD was not detectable in human plasma above ~ 4 nM, but was present in urine samples of healthy humans at a maximal concentration of 46 nM. AECK-DD was detectable in rat brain at very low levels of about 8 pmol/g wet weight. Higher levels of AECK-DD were detected in mouse brain (~1 nmol/g wet weight). Among nine dietary vegetables evaluated, only shallots were found to contain trace amounts of AECK-DD (~ 6.8 pmol/g fresh tissue). PMID:22858756

  9. Parameters Affecting Spore Recovery from Wipes Used in Biological Surface Sampling ▿ †

    PubMed Central

    Da Silva, Sandra M.; Filliben, James J.; Morrow, Jayne B.

    2011-01-01

    The need for the precise and reliable collection of potential biothreat contaminants has motivated research in developing a better understanding of the variability in biological surface sampling methods. In this context, the objective of this work was to determine parameters affecting the efficiency of extracting Bacillus anthracis Sterne spores from commonly used wipe sampling materials and to describe performance using the interfacial energy concept. In addition, surface thermodynamics was applied to understand and predict surface sampling performance. Wipe materials were directly inoculated with known concentrations of B. anthracis spores and placed into extraction solutions, followed by sonication or vortexing. Experimental factors investigated included wipe material (polyester, cotton, and polyester-rayon), extraction solution (sterile deionized water [H2O], deionized water with 0.04% Tween 80 [H2O-T], phosphate-buffered saline [PBS], and PBS with 0.04% Tween 80 [PBST]), and physical dissociation method (vortexing or sonication). The most efficient extraction from wipes was observed for solutions containing the nonionic surfactant Tween 80. The increase in extraction efficiency due to surfactant addition was attributed to an attractive interfacial energy between Tween 80 and the centrifuge tube wall, which prevented spore adhesion. Extraction solution significantly impacted the extraction efficiency, as determined by statistical analysis (P < 0.05). Moreover, the extraction solution was the most important factor in extraction performance, followed by the wipe material. Polyester-rayon was the most efficient wipe material for releasing spores into solution by rank; however, no statistically significant difference between polyester-rayon and cotton was observed (P > 0.05). Vortexing provided higher spore recovery in H2O and H2O-T than sonication, when all three wipe materials and the reference control were considered (P < 0.05). PMID:21296945

  10. A high-resolution 2D J-resolved NMR detection technique for metabolite analyses of biological samples

    NASA Astrophysics Data System (ADS)

    Huang, Yuqing; Zhang, Zhiyong; Chen, Hao; Feng, Jianghua; Cai, Shuhui; Chen, Zhong

    2015-02-01

    NMR spectroscopy is a commonly used technique for metabolite analyses. Due to the observed macroscopic magnetic susceptibility in biological tissues, current NMR acquisitions in measurements of biological tissues are generally performed on tissue extracts using liquid NMR or on tissues using magic-angle spinning techniques. In this study, we propose an NMR method to achieve high-resolution J-resolved information for metabolite analyses directly from intact biological samples. A dramatic improvement in spectral resolution is evident in our contrastive demonstrations on a sample of pig brain tissue. Metabolite analyses for a postmortem fish from fresh to decayed statuses are presented to further reveal the capability of the proposed method. This method is a previously-unreported high-resolution 2D J-resolved spectroscopy for biological applications without specialised hardware requirements or complicated sample pretreatments. It provides a significant contribution to metabolite analyses of biological samples, and may be potentially applicable to in vivo samples. Furthermore, this method also can be applied to measurements of semisolid and viscous samples.

  11. Characterization and biological studies on Co(II), Ni(II) and Cu(II) complexes of carbohydrazones ending by pyridyl ring

    NASA Astrophysics Data System (ADS)

    Abu El-Reash, G. M.; El-Gammal, O. A.; Ghazy, S. E.; Radwan, A. H.

    2013-03-01

    The chelating behavior of ligands based on carbohydrazone core modified with pyridine end towards Co(II), Ni(II) and Cu(II) ions have been examined. The ligands derived from the condensation of carbohydrazide with 2-acetylpyridine (H2APC) and 4-acetylpyridine (H2APEC). The 1H NMR, IR data and the binding energy calculations of H2APC revealed the presence of two stereoisomers syn and anti in the solid state and in the solution. The 1H NMR, IR data and the binding energy calculations confirmed the presence of H2APEC in one keto form only in the solid state and in the solution. The spectroscopic data confirmed that H2APC behaves as a monobasic pentadentate in Co(II) and Cu(II) complexes and as mononegative tetradentate in Ni(II) complex. On the other hand, H2APEC acts as a mononegative tridentate in Co(II) complex, neutral tridentate in Ni(II) complex and neutral bidentate in Cu(II) complex. The electronic spectra and the magnetic measurements of complexes as well as the ESR of the copper complexes suggested the octahedral geometry. The bond length and bond angles were evaluated by DFT method using material studio program. The thermal behavior and the kinetic parameters of degradation were determined using Coats-Redfern and Horowitz-Metzger methods. The antioxidant (DDPH and ABTS methods), anti-hemolytic and in vitro Ehrlich ascites of the compounds have been screened.

  12. Synthesis, characterization, DFT and biological studies of isatinpicolinohydrazone and its Zn(II), Cd(II) and Hg(II) complexes

    NASA Astrophysics Data System (ADS)

    El-Gammal, O. A.; Rakha, T. H.; Metwally, H. M.; Abu El-Reash, G. M.

    2014-06-01

    Isatinpicolinohydrazone (H2IPH) and its Zn(II), Cd(II) and Hg(II) complexes have been synthesized and investigated using physicochemical techniques viz. IR, 1H NMR, 13C NMR, UV-Vis spectrometric methods and magnetic moment measurements. The investigation revealed that H2IPH acts as binegative tetradentate in Zn(II), neutral tridentate in Cd(II) and as neutral bidentate towards Hg(II) complex. Octahedral geometry is proposed for all complexes. The bond length, bond angle, chemical reactivity, energy components (kcal/mol), binding energy (kcal/mol) and dipole moment (Debyes) for all the title compounds were evaluated by DFT and also MEP for the ligand is shown. Theoretical infrared intensities of H2IPH and also the theoretical electronic spectra of the ligand and its complexes were calculated. The thermal behavior and the kinetic parameters of degradation were determined using Coats-Redfern and Horowitz-Metzger methods. The in vitro antibacterial studies of the complexes proved them as growth inhibiting agents. The DDPH antioxidant of the compounds have been screened. Antitumor activity, carried out in vitro on human mammary gland (breast) MCF7, have shown that Hg(II) complex exhibited potent activity followed by Zn(II), Cd(II) complexes and the ligand.

  13. Visualizing preparation using asymmetrical choline-like ionic liquids for scanning electron microscope observation of non-conductive biological samples.

    PubMed

    Abe, Shigeaki; Hyono, Atsushi; Kawai, Koji; Yonezawa, Tetsu

    2014-03-01

    In this study, we investigated conductivity preparation for scanning electron microscope (SEM) observation that used novel asymmetrical choline-type room temperature ionic liquids (RTIL). By immersion in only an RTIL solution, clear SEM images of several types of biological samples were successfully observed. In addition, we could visualize protozoans using RTILs without any dilution. These results suggested that the asymmetrical choline-type RTILs used in this study are suitable for visualizing of biological samples by SEM. Treatment without the need for dilution can obviate the need for adjusting the RTIL concentration and provide for a rapid and easy conductivity treatment for insulating samples.

  14. Decommissioning samples from the Ft. Lewis, WA, solvent refined coal pilot plant: chemical analysis and biological testing

    SciTech Connect

    Weimer, W.C.; Wright, C.W.

    1985-10-01

    This report presents the results from chemical analyses and limited biological assays of three sets of samples from the Ft. Lewis, WA solvent refined coal (SRC) pilot plant. The samples were collected during the process of decommissioning this facility. Chemical composition was determined for chemical class fractions of the samples by using high-resolution gas chromatography (GC), high-resolution GC/mass spectrometry (MS) and high-resolution MS. Biological activity was measuring using both the histidine reversion microbial mutagenicity assay with Salmonella typhimurium, TA98 and an initiation/promotion mouse-skin tumorigenicity assay. 19 refs., 7 figs., 27 tabs.

  15. A validated HPTLC method for determination of terbutaline sulfate in biological samples: Application to pharmacokinetic study

    PubMed Central

    Faiyazuddin, Md.; Rauf, Abdul; Ahmad, Niyaz; Ahmad, Sayeed; Iqbal, Zeenat; Talegaonkar, Sushma; Bhatnagar, Aseem; Khar, Roop K.; Ahmad, Farhan J.

    2011-01-01

    Terbutaline sulfate (TBS) was assayed in biological samples by validated HPTLC method. Densitometric analysis of TBS was carried out at 366 nm on precoated TLC aluminum plates with silica gel 60F254 as a stationary phase and chloroform–methanol (9.0:1.0, v/v) as a mobile phase. TBS was well resolved at RF 0.34 ± 0.02. In all matrices, the calibration curve appeared linear (r2 ⩾ 0.9943) in the tested range of 100–1000 ng spot−1 with a limit of quantification of 18.35 ng spot−1. Drug recovery from biological fluids averaged ⩾95.92%. In both matrices, rapid degradation of drug favored and the T0.5 of drug ranged from 9.92 to 12.41 h at 4 °C and from 6.31 to 9.13 h at 20 °C. Frozen at −20 °C, this drug was stable for at least 2 months (without losses >10%). The maximum plasma concentration (Cpmax) was found to be 5875.03 ± 114 ng mL−1, which is significantly higher than the maximum saliva concentration (Csmax, 1501.69 ± 96 ng mL−1). Therefore, the validated method could be used to carry out pharmacokinetic studies of the TBS from novel drug delivery systems. PMID:23960758

  16. Recent advances in SPE-chiral-HPLC methods for enantiomeric separation of chiral drugs in biological samples.

    PubMed

    Ali, Imran; Alam, Syed Dilshad; Al-Othman, Zeid A; Farooqi, Javed A

    2013-08-01

    In medical practices, the determination of enantiomeric ratio of the chiral drugs is very important for their activities, bioavailabilities and biodegradation. Only homochiral medication is safe for humans. The chiral analysis in biological samples is the first and most important step. The present article describes the technical strategies of the enantiomeric resolution of racemic drugs in biological samples. Attempts have been made to describe sample preparation by solid-phase extraction and enantiomeric resolution by chiral high-performance liquid chromatography. Various chiral stationary phases used in chiral separations of racemic drugs have been described. Efforts are also made to discuss the chiral recognition mechanism and future perspectives of chiral analyses in biological samples.

  17. Chemical and biological effects of heavy distillate recycle in the SRC-II process

    SciTech Connect

    Wilson, B.W.; Pelroy, R.A.; Anderson, R.P.; Freel, J.

    1983-12-01

    Recent work from the Merriam Laboratory continuous coal liquefaction units shows that heavy distillate from the SRC-II process can be recycled to extinction, and hence a distillate product boiling entirely below 310/sup 0/C (590/sup 0/F) (or other selected boiling points) is feasible. In these runs distillate yield was not reduced; gas make was unaffected; and hydrogen consumption was increased only slightly, in keeping with the generally higher hydrogen content of lighter end products. Total distillate yield (C/sub 5/-590/sup 0/F) was 56 wt %, MAF coal in runs with subbituminous coal from the Amax Belle Ayr mine. Product endpoint is well below 371/sup 0/C (700/sup 0/F), the temperature above which coal distillates appear to become genotoxic; and the product was shown to be free of mutagenic activity in the Ames test. Chemical analyses showed both the < 270/sup 0/C (< 518/sup 0/F) and the < 310/sup 0/C (< 590/sup 0/F) distillates to be essentially devoid of several reference polycyclic compounds known to be carcinogenic in laboratory animals. Tests for tumorigenic or carcinogenic activity were not carried out on these materials. However, a comparison of chemical data from the Merriam heavy distillate samples with data on the other SRC-II distillates where carcinogenesis or tumorigenesis data is available leads to the expectation that < 371/sup 0/C (< 700/sup 0/F) materials from the Merriam Laboratory will have greatly reduced tumorigenic and carcinogenic activity in skin painting tests. Other studies suggest the product should be more readily upgraded than full-range (C/sub 5/-900/sup 0/F) distillate.

  18. Synthesis, characterization and biological evaluation of novel Ru(II)-arene complexes containing intercalating ligands.

    PubMed

    Nikolić, Stefan; Rangasamy, Loganathan; Gligorijević, Nevenka; Aranđelović, Sandra; Radulović, Siniša; Gasser, Gilles; Grgurić-Šipka, Sanja

    2016-07-01

    Three new ruthenium(II)-arene complexes, namely [(η(6)-p-cymene)Ru(Me2dppz)Cl]PF6 (1), [(η(6)-benzene)Ru(Me2dppz)Cl]PF6 (2) and [(η(6)-p-cymene)Ru(aip)Cl]PF6 (3) (Me2dppz=11,12-dimethyldipyrido[3,2-a:2',3'-c]phenazine; aip=2-(9-anthryl)-1H-imidazo[4,5-f] [1,10] phenanthroline) have been synthesized and characterized using different spectroscopic techniques including elemental analysis. The complexes were found to be well soluble and stable in DMSO. The biological activity of the three complexes was tested in three different human cancer cell lines (A549, MDA-MB-231 and HeLa) and in one human non-cancerous cell line (MRC-5). Complexes 1 and 3, carrying η(6)-p-cymene as the arene ligand, were shown to be toxic in all cell lines in the low micromolar/subnanomolar range, with complex 1 being the most cytotoxic complex of the series. Flow cytometry analysis revealed that complex 1 caused concentration- and time-dependent arrest of the cell cycle in G2-M and S phases in HeLa cells. This event is followed by the accumulation of the sub-G1 DNA content after 48h, in levels higher than cisplatin and in the absence of phosphatidylserine externalization. Fluorescent microscopy and acridine orange/ethidium bromide staining revealed that complex 1 induced both apoptotic and necrotic cell morphology characteristics. Drug-accumulation and DNA-binding studies performed by inductively coupled plasma mass spectrometry in HeLa cells showed that the total ruthenium uptake increased in a time- and concentration-dependent manner, and that complex 1 accumulated more efficiently than cisplatin at equimolar concentrations. The introduction of a Me2dppz ligand into the ruthenium(II)-p-cymene scaffold was found to allow the discovery of a strongly cytotoxic complex with significantly higher cellular uptake and DNA-binding properties than cisplatin.

  19. Levels of arsenic, cadmium, lead, manganese and zinc in biological samples of paralysed steel mill workers with related to controls.

    PubMed

    Afridi, Hassan Imran; Kazi, Tasneem Gul; Kazi, Atif G; Shah, Faheem; Wadhwa, Sham Kumar; Kolachi, Nida Fatima; Shah, Abdul Qadir; Baig, Jameel Ahmed; Kazi, Naveed

    2011-12-01

    The determination of essential trace and toxic elements in the biological samples of human beings is an important clinical screening procedure. This study aimed to assess the possible effects of environmental exposure on paralysed male workers (n = 75) belonging to the production and quality control departments of a steel mill. In this investigation, the concentrations of arsenic, cadmium, lead, manganese and zinc were determined in biological samples (blood, urine and scalp hair samples) of exposed paralysis and non-paralysed steel mill workers. For comparative purposes, unexposed healthy subjects of same age group were selected as referents. The elements in the biological samples were measured by atomic absorption spectrophotometry prior to microwave-assisted acid digestion. The validity of the methodology was checked by the biological certified reference materials. The results indicate that the level understudy elements in all three biological samples were significantly higher in paralysed workers of both groups (quality control and production) as compared to referents (p < 0.01). The possible connection of these elements with the aetiology of disease is discussed. The results also show the need for immediate improvements of workplace ventilation and industrial hygiene practices.

  20. Toward proteome-scale identification and quantification of isoaspartyl residues in biological samples

    PubMed Central

    Yang, Hongqian; Fung, Eva Y. M.; Zubarev, Alexander R.; Zubarev, Roman A.

    2009-01-01

    Deamidation of asparaginyl and isomerization of aspartyl residues in proteins produce a mixture of aspartyl and isoaspartyl residues, the latter being involved in protein aging and inactivation. Electron capture dissociation (ECD) combined with Fourier transform mass spectrometry (FT MS) are known to be able to distinguish the isoaspartyl peptides by unique fragments of cn• + 58.0054 (C2H2O2) and zl−n − 56.9976 (C2HO2), where n is the position of the aspartyl residue and l is the peptide length. In the present study, we tested the specificity of isoAsp detection using the accurate masses of the specific fragments. For this purpose we analyzed 32 whole and partial proteomes obtained from human cells as well as tissue samples and identified by ECD 466 isoaspartyl peptide candidates. Detailed inspection revealed that many of these candidates were unreliable. In order to increase the isoAsp detection specificity, additional criteria had to be used, e.g. adjacent c/z fragments, specific losses from the reduced species, and the shape of the chromatographic peak. Most stringent filtering of candidates yielded several cases where the presence of isoAsp was beyond doubt. Among the identified proteins with isoAsp, actin, heat shock cognate 71 kDa protein and pyruvate kinase have previously been identified as substrates for L-isoaspartyl methyltransferase, an important repair enzyme converting isoaspartyl to aspartyl. Quantification of relative isomerization degree was performed by the label-free approach. This is the first attempt to analyze the human isoaspartome in a high-throughput manner. The developed workflow allows for further enhancement of the detection rate of isoaspartyl residues in biological samples. PMID:19663459

  1. Nanoparticle sensor for label free detection of swine DNA in mixed biological samples

    NASA Astrophysics Data System (ADS)

    Ali, M. E.; Hashim, U.; Mustafa, S.; Che Man, Y. B.; Yusop, M. H. M.; Bari, M. F.; Islam, Kh N.; Hasan, M. F.

    2011-05-01

    We used 40 ± 5 nm gold nanoparticles (GNPs) as colorimetric sensor to visually detect swine-specific conserved sequence and nucleotide mismatch in PCR-amplified and non-amplified mitochondrial DNA mixtures to authenticate species. Colloidal GNPs changed color from pinkish-red to gray-purple in 2 mM PBS. Visually observed results were clearly reflected by the dramatic reduction of surface plasmon resonance peak at 530 nm and the appearance of new features in the 620-800 nm regions in their absorption spectra. The particles were stabilized against salt-induced aggregation upon the adsorption of single-stranded DNA. The PCR products, without any additional processing, were hybridized with a 17-base probe prior to exposure to GNPs. At a critical annealing temperature (55 °C) that differentiated matched and mismatched base pairing, the probe was hybridized to pig PCR product and dehybridized from the deer product. The dehybridized probe stuck to GNPs to prevent them from salt-induced aggregation and retained their characteristic red color. Hybridization of a 27-nucleotide probe to swine mitochondrial DNA identified them in pork-venison, pork-shad and venison-shad binary admixtures, eliminating the need of PCR amplification. Thus the assay was applied to authenticate species both in PCR-amplified and non-amplified heterogeneous biological samples. The results were determined visually and validated by absorption spectroscopy. The entire assay (hybridization plus visual detection) was performed in less than 10 min. The LOD (for genomic DNA) of the assay was 6 µg ml - 1 swine DNA in mixed meat samples. We believe the assay can be applied for species assignment in food analysis, mismatch detection in genetic screening and homology studies between closely related species.

  2. State of the art of environmentally friendly sample preparation approaches for determination of PBDEs and metabolites in environmental and biological samples: A critical review.

    PubMed

    Berton, Paula; Lana, Nerina B; Ríos, Juan M; García-Reyes, Juan F; Altamirano, Jorgelina C

    2016-01-28

    Green chemistry principles for developing methodologies have gained attention in analytical chemistry in recent decades. A growing number of analytical techniques have been proposed for determination of organic persistent pollutants in environmental and biological samples. In this light, the current review aims to present state-of-the-art sample preparation approaches based on green analytical principles proposed for the determination of polybrominated diphenyl ethers (PBDEs) and metabolites (OH-PBDEs and MeO-PBDEs) in environmental and biological samples. Approaches to lower the solvent consumption and accelerate the extraction, such as pressurized liquid extraction, microwave-assisted extraction, and ultrasound-assisted extraction, are discussed in this review. Special attention is paid to miniaturized sample preparation methodologies and strategies proposed to reduce organic solvent consumption. Additionally, extraction techniques based on alternative solvents (surfactants, supercritical fluids, or ionic liquids) are also commented in this work, even though these are scarcely used for determination of PBDEs. In addition to liquid-based extraction techniques, solid-based analytical techniques are also addressed. The development of greener, faster and simpler sample preparation approaches has increased in recent years (2003-2013). Among green extraction techniques, those based on the liquid phase predominate over those based on the solid phase (71% vs. 29%, respectively). For solid samples, solvent assisted extraction techniques are preferred for leaching of PBDEs, and liquid phase microextraction techniques are mostly used for liquid samples. Likewise, green characteristics of the instrumental analysis used after the extraction and clean-up steps are briefly discussed.

  3. Towards national mapping of aquatic condition (II): Predicting the probable biological condition of USA streams and rivers

    EPA Science Inventory

    The US EPA’s National River and Stream Assessment (NRSA) uses spatially balanced sampling to estimate the proportion of streams within the conterminous US (CONUS) that deviate from least-disturbed biological condition (BC). These assessments do not infer BC at un-sampled st...

  4. A new magnetic ion-imprinted polymer as a highly selective sorbent for determination of cobalt in biological and environmental samples.

    PubMed

    Khoddami, Nafiseh; Shemirani, Farzaneh

    2016-01-01

    A magnetic ion-imprinted polymer (Fe3O4@TiO2@SiO2-IIP) functionalized with -NH groups for the selective determination of Co(II) ions from environmental and biological samples is presented. This sorbent was synthesized by surface imprinting technique combined with sol-gel process using 3-(2-aminoethylamino) propyltrimethoxysilane (AAPTS) as a functional ligand, tetraethyl orthosilicate as across-linking agent, and Co(II) ion as the template. The prepared magnetic ion-imprinted polymer was characterized by infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), dynamic light scattering (DLS), and X-ray diffraction (XRD). Fe3O4@TiO2@SiO2-IIP showed higher capacity and selectivity than that of Fe3O4@TiO2@SiO2-NIP. The important parameters influencing the recovery such as pH, the volume and eluent concentration, contact time, and the amount of sorbent on extraction percentage of Fe3O4@TiO2@SiO2-IIP were studied and optimized. The linear range (LR), relative standard deviation(RSD) and limit of detection (LOD=3 S(b)/m) for flame atomic absorption spectrometric determination of Co(II) ion, after its selective extraction by the prepared IIP polymer, were evaluated as 1-130 µg L(-1), 1.22% and 0.15 µg L(-1), respectively. The maximum capacity of Fe3O4@TiO2@SiO2-IIP and Fe3O4@TiO2@SiO2-NIP is 35.21 mg g(-1) and 10.34 mg g(-1), respectively. The separation factor of Fe3O4@TiO2@SiO2-IIP for Co(II)/Pb(II), Co(II)/Ni(II), and Co(II)/Cd(II) are 41.17, 79.74, and 56.48, respectively. In addition, the spent magnetic ion-imprinted polymer can be refreshed by simply washing with an aqueous HNO3 solution, and there is no significant decrease in adsorption capacity after a test of upto seven cycles, demonstrating that the Fe3O4@ TiO2@SiO2-IIP is stable and reusable. PMID:26695259

  5. A new magnetic ion-imprinted polymer as a highly selective sorbent for determination of cobalt in biological and environmental samples.

    PubMed

    Khoddami, Nafiseh; Shemirani, Farzaneh

    2016-01-01

    A magnetic ion-imprinted polymer (Fe3O4@TiO2@SiO2-IIP) functionalized with -NH groups for the selective determination of Co(II) ions from environmental and biological samples is presented. This sorbent was synthesized by surface imprinting technique combined with sol-gel process using 3-(2-aminoethylamino) propyltrimethoxysilane (AAPTS) as a functional ligand, tetraethyl orthosilicate as across-linking agent, and Co(II) ion as the template. The prepared magnetic ion-imprinted polymer was characterized by infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), dynamic light scattering (DLS), and X-ray diffraction (XRD). Fe3O4@TiO2@SiO2-IIP showed higher capacity and selectivity than that of Fe3O4@TiO2@SiO2-NIP. The important parameters influencing the recovery such as pH, the volume and eluent concentration, contact time, and the amount of sorbent on extraction percentage of Fe3O4@TiO2@SiO2-IIP were studied and optimized. The linear range (LR), relative standard deviation(RSD) and limit of detection (LOD=3 S(b)/m) for flame atomic absorption spectrometric determination of Co(II) ion, after its selective extraction by the prepared IIP polymer, were evaluated as 1-130 µg L(-1), 1.22% and 0.15 µg L(-1), respectively. The maximum capacity of Fe3O4@TiO2@SiO2-IIP and Fe3O4@TiO2@SiO2-NIP is 35.21 mg g(-1) and 10.34 mg g(-1), respectively. The separation factor of Fe3O4@TiO2@SiO2-IIP for Co(II)/Pb(II), Co(II)/Ni(II), and Co(II)/Cd(II) are 41.17, 79.74, and 56.48, respectively. In addition, the spent magnetic ion-imprinted polymer can be refreshed by simply washing with an aqueous HNO3 solution, and there is no significant decrease in adsorption capacity after a test of upto seven cycles, demonstrating that the Fe3O4@ TiO2@SiO2-IIP is stable and reusable.

  6. Unbiased Rare Event Sampling in Spatial Stochastic Systems Biology Models Using a Weighted Ensemble of Trajectories.

    PubMed

    Donovan, Rory M; Tapia, Jose-Juan; Sullivan, Devin P; Faeder, James R; Murphy, Robert F; Dittrich, Markus; Zuckerman, Daniel M

    2016-02-01

    The long-term goal of connecting scales in biological simulation can be facilitated by scale-agnostic methods. We demonstrate that the weighted ensemble (WE) strategy, initially developed for molecular simulations, applies effectively to spatially resolved cell-scale simulations. The WE approach runs an ensemble of parallel trajectories with assigned weights and uses a statistical resampling strategy of replicating and pruning trajectories to focus computational effort on difficult-to-sample regions. The method can also generate unbiased estimates of non-equilibrium and equilibrium observables, sometimes with significantly less aggregate computing time than would be possible using standard parallelization. Here, we use WE to orchestrate particle-based kinetic Monte Carlo simulations, which include spatial geometry (e.g., of organelles, plasma membrane) and biochemical interactions among mobile molecular species. We study a series of models exhibiting spatial, temporal and biochemical complexity and show that although WE has important limitations, it can achieve performance significantly exceeding standard parallel simulation--by orders of magnitude for some observables.

  7. The method of radioactive tracer for measuring the amount of inorganic nanoparticles in biological samples

    NASA Astrophysics Data System (ADS)

    Buzulukov, Yu; Antsiferova, A.; Demin, V. A.; Demin, V. F.; Kashkarov, P.

    2015-11-01

    The method to measure the mass of inorganic nanoparticles in biological (or any other samples) using nanoparticles labeled with radioactive tracers is developed and applied to practice. The tracers are produced in original nanoparticles by radioactive activation of some of their atomic nuclei. The method of radioactive tracers demonstrates a sensitivity, specificity and accuracy equal or better than popular methods of optical and mass spectrometry, or electron microscopy and has some specific advantages. The method can be used for study of absorption, distribution, metabolism and excretion in living organism, as well as in ecological and fundamental research. It was used in practice to study absorption, distribution, metabolism and excretion of nanoparticles of Ag, Au, Se, ZnO, TiO2 as well as to study transportation of silver nanoparticles through the barriers of blood-brain, placenta and milk gland of rats. Brief descriptions of data obtained in experiments with application of this method included in the article. The method was certified in Russian Federation standard system GOST-R and recommended by the Russian Federation regulation authority ROSPOTREBNADZOR for measuring of toxicokinetic and organotropy parameters of nanoparticles.

  8. Development of novel separation techniques for biological samples in capillary electrophoresis

    SciTech Connect

    Chang, H.T.

    1994-07-27

    This dissertation includes three different topics: general introduction of capillary electrophoresis (CE); gradient in CE and CE in biological separations; and capillary gel electrophoresis (CGE) for DNA separation. Factors such as temperature, viscosity, pH, and the surface of capillary walls affecting the separation performance are demonstrated. A pH gradient between 3.0 and 5.2 is useful to improve the resolution among eight different organic acids. A flow gradient due to the change in the concentration of surfactant, which is able to coat to the capillary wall to change the flow rate and its direction, is also shown as a good way to improve the resolution for organic compounds. A temperature gradient caused by joule heat is shown by voltage programming to enhance the resolution and shorten the separation time for several phenolic compounds. The author also shows that self-regulating dynamic control of electroosmotic flow in CE by simply running separation in different concentrations of surfactant has less matrix effect on the separation performance. One of the most important demonstrations in this dissertation is that the author proposes on-column reaction which gives several advantages including the use of a small amount of sample, low risk of contamination, and time saving and kinetic features. The author uses this idea with laser induced fluorescence (LIF) as a detection mode to detect an on-column digestion of sub-ng of protein. This technique also is applied to single cell analysis in the group.

  9. Smart oxygen cuvette for optical monitoring of dissolved oxygen in biological blood samples

    NASA Astrophysics Data System (ADS)

    Dabhi, Harish; Alla, Suresh Kumar; Shahriari, Mahmoud R.

    2010-02-01

    A smart Oxygen Cuvette is developed by coating the inner surface of a cuvette with oxygen sensitive thin film material. The coating is glass like sol-gel based sensor that has an embedded ruthenium compound in the glass film. The fluorescence of the ruthenium is quenched depending on the oxygen level. Ocean Optics phase fluorometer, NeoFox is used to measure this rate of fluorescence quenching and computes it for the amount of oxygen present. Multimode optical fibers are used for transportation of light from an LED source to cuvette and from cuvette to phase fluorometer. This new oxygen sensing system yields an inexpensive solution for monitoring the dissolved oxygen in samples for biological and medical applications. In addition to desktop fluorometers, smart oxygen cuvettes can be used with the Ocean Optics handheld Fluorometers, NeoFox Sport. The Smart Oxygen Cuvettes provide a resolution of 4PPB units, an accuracy of less than 5% of the reading, and 90% response in less than 10 seconds.

  10. Quantification of transition metals in biological samples and its possible impact on ferro-alloy workers.

    PubMed

    Mishra, Sandhya; Ramteke, Dilip S; Wate, Satish R

    2007-10-01

    Increased risk of ill-health and diseases has been associated with employment in the ferro-alloy factory. Since measurement of transition metals in human blood and hair along with respective exposure rates, provides a means of assessing individual risk, it has been the most important part of the study. In the study majority of the elements in the transition series, such as, vanadium (V), chromium (Cr), iron (Fe), manganese (Mn), cobalt, (Co) nickel (Ni), copper (Cu), zinc (Zn), molybdenum (Mo) and cadmium (Cd) were considered which are randomly emitted from the source, that is, manganese ore (used during ferro-alloy manufacturing process). The commonly available transition, metals, observed in biological samples of ferro-alloy workers, were found to be Fe, Zn, Co, Ni, Cu, Cr, Cd, V Mn and Mo in blood, while in hair, Mn, Fe, Zn, Co, Ni, Cu, Cr, Cd, V and Mo were present in decreasing order Surveillance of bio-concentration of these metals in workers, exposed to close proximity of the coke-ovens and smelting furnaces, revealed that the workers were prone to several physical disorders. PMID:18405124

  11. Quantitation of retinaldehyde in small biological samples using ultrahigh-performance liquid chromatography MS/MS

    PubMed Central

    Wang, Jinshan; Yoo, Hong Sik; Obrochta, Kristin M.; Huang, Priscilla; Napoli, Joseph L.

    2015-01-01

    We report an UHPLC-MS/MS to quantify all-trans-retinal in biological samples of limited size (15-35 mg), which is especially advantageous for use with adipose. To facilitate recovery, retinal and the internal standard 3,4-didehydroretinal were derivatized in situ into their O-ethyloximes. UHPLC resolution combined with high sensitivity and specificity of MS/MS allowed quantification of retinal-O-ethyloximes with a 5 fmol lower limit of detection and a linear range from 5 fmol to 1 pmol. This assay revealed that extra-ocular concentrations of retinal range from ~2 to 40 pmol/g in multiple tissues: the same range as all-trans-retinoic acid. All-trans-retinoic acid has high affinity (kd ≤ 0.4 nM) for its nuclear receptors (RARα, β, γ), whereas retinal has low, if any affinity for these receptors, making it unlikely that these retinal concentrations would activate RAR. We also show that the copious amount of vitamin A used in chow diets increases retinal in adipose depots 2 to 5-fold relative to levels in adipose of mice fed a vitamin A-sufficient diet, as recommended for laboratory rodents. This assay also is proficient for quantifying conversion of retinol into retinal in vitro, and therefore provides an efficient method to study metabolism of retinol in vivo and in vitro. PMID:26045160

  12. An integrative strategy for quantitative analysis of the N-glycoproteome in complex biological samples

    PubMed Central

    2014-01-01

    Background The complexity of protein glycosylation makes it difficult to characterize glycosylation patterns on a proteomic scale. In this study, we developed an integrated strategy for comparatively analyzing N-glycosylation/glycoproteins quantitatively from complex biological samples in a high-throughput manner. This strategy entailed separating and enriching glycopeptides/glycoproteins using lectin affinity chromatography, and then tandem labeling them with 18O/16O to generate a mass shift of 6 Da between the paired glycopeptides, and finally analyzing them with liquid chromatography-mass spectrometry (LC-MS) and the automatic quantitative method we developed based on Mascot Distiller. Results The accuracy and repeatability of this strategy were first verified using standard glycoproteins; linearity was maintained within a range of 1:10–10:1. The peptide concentration ratios obtained by the self-build quantitative method were similar to both the manually calculated and theoretical values, with a standard deviation (SD) of 0.023–0.186 for glycopeptides. The feasibility of the strategy was further confirmed with serum from hepatocellular carcinoma (HCC) patients and healthy individuals; the expression of 44 glycopeptides and 30 glycoproteins were significantly different between HCC patient and control serum. Conclusions This strategy is accurate, repeatable, and efficient, and may be a useful tool for identification of disease-related N-glycosylation/glycoprotein changes. PMID:24428921

  13. Quantification of transition metals in biological samples and its possible impact on ferro-alloy workers.

    PubMed

    Mishra, Sandhya; Ramteke, Dilip S; Wate, Satish R

    2007-10-01

    Increased risk of ill-health and diseases has been associated with employment in the ferro-alloy factory. Since measurement of transition metals in human blood and hair along with respective exposure rates, provides a means of assessing individual risk, it has been the most important part of the study. In the study majority of the elements in the transition series, such as, vanadium (V), chromium (Cr), iron (Fe), manganese (Mn), cobalt, (Co) nickel (Ni), copper (Cu), zinc (Zn), molybdenum (Mo) and cadmium (Cd) were considered which are randomly emitted from the source, that is, manganese ore (used during ferro-alloy manufacturing process). The commonly available transition, metals, observed in biological samples of ferro-alloy workers, were found to be Fe, Zn, Co, Ni, Cu, Cr, Cd, V Mn and Mo in blood, while in hair, Mn, Fe, Zn, Co, Ni, Cu, Cr, Cd, V and Mo were present in decreasing order Surveillance of bio-concentration of these metals in workers, exposed to close proximity of the coke-ovens and smelting furnaces, revealed that the workers were prone to several physical disorders.

  14. Unbiased Rare Event Sampling in Spatial Stochastic Systems Biology Models Using a Weighted Ensemble of Trajectories

    PubMed Central

    Donovan, Rory M.; Tapia, Jose-Juan; Sullivan, Devin P.; Faeder, James R.; Murphy, Robert F.; Dittrich, Markus; Zuckerman, Daniel M.

    2016-01-01

    The long-term goal of connecting scales in biological simulation can be facilitated by scale-agnostic methods. We demonstrate that the weighted ensemble (WE) strategy, initially developed for molecular simulations, applies effectively to spatially resolved cell-scale simulations. The WE approach runs an ensemble of parallel trajectories with assigned weights and uses a statistical resampling strategy of replicating and pruning trajectories to focus computational effort on difficult-to-sample regions. The method can also generate unbiased estimates of non-equilibrium and equilibrium observables, sometimes with significantly less aggregate computing time than would be possible using standard parallelization. Here, we use WE to orchestrate particle-based kinetic Monte Carlo simulations, which include spatial geometry (e.g., of organelles, plasma membrane) and biochemical interactions among mobile molecular species. We study a series of models exhibiting spatial, temporal and biochemical complexity and show that although WE has important limitations, it can achieve performance significantly exceeding standard parallel simulation—by orders of magnitude for some observables. PMID:26845334

  15. Square wave voltammetry in the determination of Ni2+ and Al3+ in biological sample.

    PubMed

    Paulino, Alexandre T; Vargas, Alexandro M M; Santos, Lídia B; Nozaki, Jorge; Muniz, Edvani C; Tambourgi, Elias B

    2008-01-01

    In this contribution, the amounts of Ni (nickel) and Al (aluminum) in tilapias (Oreochromis niloticus) were determined using square wave voltammetry (SWV) with glassy carbon working microelectrode with a mercury thin film, platinum counter electrode, and Ag/AgCl reference electrode. Ni was studied through the formation of the dimethylglyoxime-Ni (Ni-DMG) complex, while Al was studied through the formation of the Alizarin R-Al complex. The detection limit found for Ni-DMG and Alizarin R-Al complexes were 1.70 x 10(-7) and 1.0 x 10(-8) mol L(-1), respectively. The voltammetric anodic curves for the Alizarin R-Al complex were recorded over the potential range from -0.8 to -0.05 V while the voltammetric cathodic curve for the Ni-DMG complex was recorded over the potential range from -0.7 to -1.2 V. These methods detected low concentrations of Ni and Al in biological samples efficiently.

  16. Biological low pH Mn(II) oxidation in a manganese deposit influenced by metal-rich groundwater

    USGS Publications Warehouse

    Bohu, Tsing; Akob, Denise M.; Abratis, Michael; Lazar, Cassandre S.; Küsel, Kirsten

    2016-01-01

    The mechanisms, key organisms, and geochemical significance of biological low-pH Mn(II) oxidation are largely unexplored. Here, we investigated the structure of indigenous Mn(II)-oxidizing microbial communities in a secondary subsurface Mn oxide deposit influenced by acidic (pH 4.8) metal-rich groundwater in a former uranium mining area. Microbial diversity was highest in the Mn deposit compared to the adjacent soil layers and included the majority of known Mn(II)-oxidizing bacteria (MOB) and two genera of known Mn(II)-oxidizing fungi (MOF). Electron X-ray microanalysis showed that romanechite [(Ba,H2O)2(Mn4+,Mn3+)5O10] was conspicuously enriched in the deposit. Canonical correspondence analysis revealed that certain fungal, bacterial, and archaeal groups were firmly associated with the autochthonous Mn oxides. Eight MOB within the Proteobacteria, Actinobacteria, and Bacteroidetes and one MOF strain belonging to Ascomycota were isolated at pH 5.5 or 7.2 from the acidic Mn deposit. Soil-groundwater microcosms demonstrated 2.5-fold-faster Mn(II) depletion in the Mn deposit than adjacent soil layers. No depletion was observed in the abiotic controls, suggesting that biological contribution is the main driver for Mn(II) oxidation at low pH. The composition and species specificity of the native low-pH Mn(II) oxidizers were highly adapted to in situ conditions, and these organisms may play a central role in the fundamental biogeochemical processes (e.g., metal natural attenuation) occurring in the acidic, oligotrophic, and metalliferous subsoil ecosystems.

  17. Zinc(II) complexes with dithiocarbamato derivatives: structural characterisation and biological assays on cancerous cell lines.

    PubMed

    Nagy, Eszter Márta; Sitran, Sergio; Montopoli, Monica; Favaro, Monica; Marchiò, Luciano; Caparrotta, Laura; Fregona, Dolores

    2012-12-01

    Zinc is one of the most important trace elements in the body and it is essential as a cofactor for the structure and function of a number of cellular molecules including enzymes, transcription factors, cellular signalling proteins and DNA repair enzymes. On the other hand, recent studies have shown that zinc could play a role both in the development of various cancers and in the induction of apoptosis in some cell types, however, no established common relationships of zinc with cancer development and progression have been identified. To date, in our research group different metal-dithiocarbamato complexes have been designed that were expected to resemble the main features of cisplatin together with higher activity, improved selectivity and bioavailability, and lower side-effects. On the basis of the obtained encouraging achievements with other metals (such as gold and copper) we have decided to enlarge the studies to the complexes of zinc(II) using the same ligands. Hereby, we report the results on the synthesis and characterisation of ZnL(2) complexes with five different dithiocarbamato derivatives, such as dimethyl-(DMDT), pyrrolidine-(PyDT), methyl-(MSDT), ethyl-(ESDT) and tert-butyl-(TSDT) sarcosinedithiocarbamate. All the obtained compounds have fully been characterised by means of several spectroscopic techniques. In addition, the crystal structure of [Zn(MSDT)(2)](2) dinuclear complex is also reported. In order to evaluate the in vitro cytotoxic properties, some biological assays have been carried out on a panel of human tumour cell lines sensible and resistant to cisplatin. Some of the tested compounds show cytotoxicity levels comparable or even greater than the reference drug (cisplatin). PMID:23085593

  18. Structural, spectral, pH-metric and biological studies on mercury (II), cadmium (II) and binuclear zinc (II) complexes of NS donor thiosemicarbazide ligand.

    PubMed

    El-Gammal, Ola A; Abu El-Reash, Gaber M; El-Gamil, Mohammed M

    2014-04-01

    Hg(II), Cd(II) and binuclear Zn(II) complexes derived from the tetradentate N(1)-ethyl-N(2)-(pyridine-2-yl) hydrazine-1, 2-bis (carbothioamide) ligand (H2PET) have been prepared and characterized by conventional techniques. The isolated complexes acquired the formulas, [Hg(HPET)(H2O)2Cl]⋅H2O, [Cd(HPET)Cl] and [Zn2(HPET)(PET)(OAc)]⋅H2O, respectively. IR data revealed that the ligand behaves as monobasic tridentate through (CN)py, (C-S) and new (NC)azomethine(∗) groups in both Hg(II) and Cd(II) complexes. In the binuclear Zn(II) complex, the behavior of ligand contains two types, where H2PET acts as dibasic tetradentate via (CN)py, both deprotonated (C-SH) and the new (NC)azomethine(∗) towards two Zn atoms and also it acts as monobasic tridentate via (CS), deprotonated (C-SH) and (CN)py towards the same Zn atoms. An octahedral geometry for Hg(II) complex and tetrahedral geometry for both Cd(II) and Zn(II) complexes were proposed. The bond lengths, bond angles, HOMO, LUMO and dipole moment have been calculated by DFT using materials studio program to confirm the geometry of ligand and its metal complexes. The association constant of the ligand and the stability constants of its complexes as well as the thermodynamic parameters were calculated by pH metric measurements at 298, 308 and 318K in 50% dioxane-water mixture, respectively. Also, the kinetic and thermodynamic parameters for the different thermal degradation steps of the complexes were determined by Coats-Redfern and Horowitz-Metzger methods. Moreover, the anti-oxidant (using ABTS and DPPH methods), anti-hemolytic, and cytotoxic activities of the compounds have been tested.

  19. Synthesis of uranyl(II), vanadyl(II) and zirconyl urate complexes, spectral, thermal and biological studies

    NASA Astrophysics Data System (ADS)

    El-Megharbel, Samy M.; El-Metwaly, Nashwa M.; Refat, Moamen S.

    2015-10-01

    Three urate chelations were obtained when uric acid was reacted with UO2(CH3COO)2H2O, VOSO4·XH2O and ZrOCl2·XH2O salts with neutralized with 0.1 M NaOH aqueous media. The 1:2 metal-to-ligand complexes [(UO2)2(C5H2N4O3)2](H2O), [(ZrO)2(H2O)2(C5H2N4O3)2] and [VO((C5H3N4O3)2] were characterized by elemental analyses, molar conductivity, (infrared, Raman and UV-vis) spectra, effective magnetic moment in Bohr magnetons, and thermal analysis (TG/DTG). The urate ligand coordinates as mononegative bidentate donor towards the mononuclear central vanadium atom and coordinated as binegative tetradentate mode towards the binuclear dioxouranium and zirconyl centers. The antibacterial activity of the metal complexes were tested against some kind of bacteria and fungi strains and compared with uric acid. The ligand, ZrO(II) and UO2(II) complex showed a week potential degradation on calf thymus DNA, whereas VO(II) complex slightly degraded the DNA.

  20. Method development for mass spectrometry based molecular characterization of fossil fuels and biological samples

    NASA Astrophysics Data System (ADS)

    Mahat, Rajendra K.

    In an analytical (chemical) method development process, the sample preparation step usually determines the throughput and overall success of the analysis. Both targeted and non-targeted methods were developed for the mass spectrometry (MS) based analyses of fossil fuels (coal) and lipidomic analyses of a unique micro-organism, Gemmata obscuriglobus. In the non-targeted coal analysis using GC-MS, a microwave-assisted pressurized sample extraction method was compared with the traditional extraction method, such as Soxhlet. On the other hand, methods were developed to establish a comprehensive lipidomic profile and to confirm the presence of endotoxins (a.k.a. lipopolysaccharides, LPS) in Gemmata.. The performance of pressurized heating techniques employing hot-air oven and microwave irradiation were compared with that of Soxhlet method in terms of percentage extraction efficiency and extracted analyte profiles (via GC-MS). Sub-bituminous (Powder River Range, Wyoming, USA) and bituminous (Fruitland formation, Colorado, USA) coal samples were tested. Overall 30-40% higher extraction efficiencies (by weight) were obtained with a 4 hour hot-air oven and a 20 min microwave-heating extraction in a pressurized container when compared to a 72 hour Soxhlet extraction. The pressurized methods are 25 times more economic in terms of solvent/sample amount used and are 216 times faster in term of time invested for the extraction process. Additionally, same sets of compounds were identified by GC-MS for all the extraction methods used: n-alkanes and diterpanes in the sub-bituminous sample, and n-alkanes and alkyl aromatic compounds in the bituminous coal sample. G. obscuriglobus, a nucleated bacterium, is a micro-organism of high significances from evolutionary, cell and environmental biology standpoints. Although lipidomics is an essential tool in microbiological systematics and chemotaxonomy, complete lipid profile of this bacterium is still lacking. In addition, the presence of

  1. Dimensional comparison between amplitude-modulation atomic force microscopy and scanning ion conductance microscopy of biological samples

    NASA Astrophysics Data System (ADS)

    Kim, Joonhui; Choi, MyungHoon; Jung, Goo-Eun; Rahim Ferhan, Abdul; Cho, Nam-Joon; Cho, Sang-Joon

    2016-08-01

    The range of scanning probe microscopy (SPM) applications for atomic force microscopy (AFM) is expanding in the biological sciences field, reflecting an increasing demand for tools that can improve our fundamental understanding of the physics behind biological systems. However, the complexity associated with applying SPM techniques in biomedical research hampers the full exploitation of its capabilities. Recently, the development of scanning ion conductance microscopy (SICM) has overcome these limitations and enabled contact-free, high resolution imaging of live biological specimens. In this work, we demonstrate the limitation of AFM for imaging biological samples in liquid due to artifacts arising from AFM tip-sample interaction, and how SICM imaging is able to overcome those limitations with contact-free scanning. We also demonstrate that SICM measurements, when compared to AFM, show better fit to the actual dimensions of the biological samples. Our results highlight the superiority of SICM imaging, enabling it to be widely adopted as a general and versatile research tool for biological studies in the nanoscale.

  2. Dimensional comparison between amplitude-modulation atomic force microscopy and scanning ion conductance microscopy of biological samples

    NASA Astrophysics Data System (ADS)

    Kim, Joonhui; Choi, MyungHoon; Jung, Goo-Eun; Rahim Ferhan, Abdul; Cho, Nam-Joon; Cho, Sang-Joon

    2016-08-01

    The range of scanning probe microscopy (SPM) applications for atomic force microscopy (AFM) is expanding in the biological sciences field, reflecting an increasing demand for tools that can improve our fundamental understanding of the physics behind biological systems. However, the complexity associated with applying SPM techniques in biomedical research hampers the full exploitation of its capabilities. Recently, the development of scanning ion conductance microscopy (SICM) has overcome these limitations and enabled contact-free, high resolution imaging of live biological specimens. In this work, we demonstrate the limitation of AFM for imaging biological samples in liquid due to artifacts arising from AFM tip–sample interaction, and how SICM imaging is able to overcome those limitations with contact-free scanning. We also demonstrate that SICM measurements, when compared to AFM, show better fit to the actual dimensions of the biological samples. Our results highlight the superiority of SICM imaging, enabling it to be widely adopted as a general and versatile research tool for biological studies in the nanoscale.

  3. Insights on Antioxidant Assays for Biological Samples Based on the Reduction of Copper Complexes—The Importance of Analytical Conditions

    PubMed Central

    Marques, Sara S.; Magalhães, Luís M.; Tóth, Ildikó V.; Segundo, Marcela A.

    2014-01-01

    Total antioxidant capacity assays are recognized as instrumental to establish antioxidant status of biological samples, however the varying experimental conditions result in conclusions that may not be transposable to other settings. After selection of the complexing agent, reagent addition order, buffer type and concentration, copper reducing assays were adapted to a high-throughput scheme and validated using model biological antioxidant compounds of ascorbic acid, Trolox (a soluble analogue of vitamin E), uric acid and glutathione. A critical comparison was made based on real samples including NIST-909c human serum certified sample, and five study samples. The validated method provided linear range up to 100 µM Trolox, (limit of detection 2.3 µM; limit of quantification 7.7 µM) with recovery results above 85% and precision <5%. The validated developed method with an increased sensitivity is a sound choice for assessment of TAC in serum samples. PMID:24968275

  4. The RMS survey: resolving kinematic distance ambiguities towards a sample of compact H II regions using H I absorption

    NASA Astrophysics Data System (ADS)

    Urquhart, J. S.; Hoare, M. G.; Lumsden, S. L.; Oudmaijer, R. D.; Moore, T. J. T.; Mottram, J. C.; Cooper, H. D. B.; Mottram, M.; Rogers, H. C.

    2012-02-01

    We present high-resolution H I data obtained using the Australia Telescope Compact Array to resolve the near/far distance ambiguities towards a sample of compact H II regions from the Red MSX Source (RMS) survey. The high-resolution data are complemented with lower resolution archival H I data extracted from the Southern and Very Large Array (VLA) Galactic Plane surveys. We resolve the distance ambiguity for nearly all of the 105 sources where the continuum was strong enough to allow analysis of the H I absorption line structure. This represents another step in the determination of distances to the total RMS sample, which with over 1000 massive young stellar objects and compact H II regions is the largest and most complete sample of its kind. The full sample will allow the distribution of massive star formation in the Galaxy to be examined. Full versions of Figs 3 and 4 are only available in electronic form of the journal.

  5. Determination of cadmium(II), cobalt(II), nickel(II), lead(II), zinc(II), and copper(II) in water samples using dual-cloud point extraction and inductively coupled plasma emission spectrometry.

    PubMed

    Zhao, Lingling; Zhong, Shuxian; Fang, Keming; Qian, Zhaosheng; Chen, Jianrong

    2012-11-15

    A dual-cloud point extraction (d-CPE) procedure has been developed for simultaneous pre-concentration and separation of heavy metal ions (Cd2+, Co2+, Ni2+, Pb2+, Zn2+, and Cu2+ ion) in water samples by inductively coupled plasma optical emission spectrometry (ICP-OES). The procedure is based on forming complexes of metal ion with 8-hydroxyquinoline (8-HQ) into the as-formed Triton X-114 surfactant rich phase. Instead of direct injection or analysis, the surfactant rich phase containing the complexes was treated by nitric acid, and the detected ions were back extracted again into aqueous phase at the second cloud point extraction stage, and finally determined by ICP-OES. Under the optimum conditions (pH=7.0, Triton X-114=0.05% (w/v), 8-HQ=2.0×10(-4) mol L(-1), HNO3=0.8 mol L(-1)), the detection limits for Cd2+, Co2+, Ni2+, Pb2+, Zn2+, and Cu2+ ions were 0.01, 0.04, 0.01, 0.34, 0.05, and 0.04 μg L(-1), respectively. Relative standard deviation (RSD) values for 10 replicates at 100 μg L(-1) were lower than 6.0%. The proposed method could be successfully applied to the determination of Cd2+, Co2+, Ni2+, Pb2+, Zn2+, and Cu2+ ion in water samples.

  6. Self-esteem in adolescents with Angle Class I, II and III malocclusion in a Peruvian sample

    PubMed Central

    Florián-Vargas, Karla; Honores, Marcos J. Carruitero; Bernabé, Eduardo; Flores-Mir, Carlos

    2016-01-01

    ABSTRACT Objective: To compare self-esteem scores in 12 to 16-year-old adolescents with different Angle malocclusion types in a Peruvian sample. Material and Methods: A cross-sectional study was conducted in a sample of 276 adolescents (159, 52 and 65 with Angle Class I, II and III malocclusions, respectively) from Trujillo, Peru. Participants were asked to complete the Rosenberg Self-Esteem Scale (RSES) and were also clinically examined, so as to have Angle malocclusion classification determined. Analysis of covariance (ANCOVA) was used to compare RSES scores among adolescents with Class I, II and III malocclusions, with participants' demographic factors being controlled. Results: Mean RSES scores for adolescents with Class I, II and III malocclusions were 20.47 ± 3.96, 21.96 ± 3.27 and 21.26 ± 4.81, respectively. The ANCOVA test showed that adolescents with Class II malocclusion had a significantly higher RSES score than those with Class I malocclusion, but there were no differences between other malocclusion groups. Supplemental analysis suggested that only those with Class II, Division 2 malocclusion might have greater self-esteem when compared to adolescents with Class I malocclusion. Conclusion: This study shows that, in general, self-esteem did not vary according to adolescents' malocclusion in the sample studied. Surprisingly, only adolescents with Class II malocclusion, particularly Class II, Division 2, reported better self-esteem than those with Class I malocclusion. A more detailed analysis assessing the impact of anterior occlusal features should be conducted. PMID:27275616

  7. A method of high sensitivity and in situ determination of trace cobalt(II) in water samples with salicyl fluorone.

    PubMed

    Chen, Zhe; Li, Hua

    2014-01-01

    Based on the sensitive reaction of Co(II) and salicyl fluorone with the presence of cetylpyridinium bromide in basic solution, a new method of flow injection micelle-solubilized spectrophotometry was developed for the determination of cobalt. The reaction was monitored for the absorbance of Co(II) at 540 nm. The reagents, flow injection variables and effects of foreign ions were investigated and the optimum conditions were established. At the optimum test conditions, the developed method provides a linearity range of 3-40 μg L(-1) with a detection limit of 0.1 μg L(-1) at about 60 h(-1) sampling frequency. Relative standard deviation of 0.91, 0.95 and 0.89% were obtained for the determination of 3, 15 and 30 μg L(-1) Co(II) solution. The proposed method has been successfully applied for analysis of trace amounts of cobalt in water samples. PMID:25325542

  8. J-Band Infrared Spectroscopy of a Sample of Brown Dwarfs Using NIRSPEC on Keck II.

    PubMed

    McLean; Wilcox; Becklin; Figer; Gilbert; Graham; Larkin; Levenson; Teplitz; Kirkpatrick

    2000-04-10

    Near-infrared spectroscopic observations of a sample of very cool, low-mass objects are presented with higher spectral resolution than in any previous studies. Six of the objects are L dwarfs, ranging in spectral class from L2 to L8/9, and the seventh is a methane or T dwarf. These new observations were obtained during commissioning of the near-infrared spectrometer (NIRSPEC), the first high-resolution near-infrared cryogenic spectrograph for the Keck II 10 m telescope on Mauna Kea, Hawaii. Spectra with a resolving power of R approximately 2500 from 1.135 to 1.360 µm (approximately J band) are presented for each source. At this resolution, a rich spectral structure is revealed, much of which is due to blending of unresolved molecular transitions. Strong lines due to neutral potassium (K i) and bands due to iron hydride (FeH) and steam (H2O) change significantly throughout the L sequence. Iron hydride disappears between L5 and L8, the steam bands deepen, and the K i lines gradually become weaker but wider because of pressure broadening. An unidentified feature occurs at 1.22 µm that has a temperature dependence like FeH but has no counterpart in the available FeH opacity data. Because these objects are 3-6 mag brighter in the near-infrared compared with the I band, spectral classification is efficient. One of the objects studied (2MASSW J1523+3014) is the coolest L dwarf discovered so far by the 2 Micron All-Sky Survey (2MASS), but its spectrum is still significantly different from the methane-dominated objects such as Gl 229B or SDSS 1624+0029. PMID:10727388

  9. J-Band Infrared Spectroscopy of a Sample of Brown Dwarfs Using NIRSPEC on Keck II.

    PubMed

    McLean; Wilcox; Becklin; Figer; Gilbert; Graham; Larkin; Levenson; Teplitz; Kirkpatrick

    2000-04-10

    Near-infrared spectroscopic observations of a sample of very cool, low-mass objects are presented with higher spectral resolution than in any previous studies. Six of the objects are L dwarfs, ranging in spectral class from L2 to L8/9, and the seventh is a methane or T dwarf. These new observations were obtained during commissioning of the near-infrared spectrometer (NIRSPEC), the first high-resolution near-infrared cryogenic spectrograph for the Keck II 10 m telescope on Mauna Kea, Hawaii. Spectra with a resolving power of R approximately 2500 from 1.135 to 1.360 µm (approximately J band) are presented for each source. At this resolution, a rich spectral structure is revealed, much of which is due to blending of unresolved molecular transitions. Strong lines due to neutral potassium (K i) and bands due to iron hydride (FeH) and steam (H2O) change significantly throughout the L sequence. Iron hydride disappears between L5 and L8, the steam bands deepen, and the K i lines gradually become weaker but wider because of pressure broadening. An unidentified feature occurs at 1.22 µm that has a temperature dependence like FeH but has no counterpart in the available FeH opacity data. Because these objects are 3-6 mag brighter in the near-infrared compared with the I band, spectral classification is efficient. One of the objects studied (2MASSW J1523+3014) is the coolest L dwarf discovered so far by the 2 Micron All-Sky Survey (2MASS), but its spectrum is still significantly different from the methane-dominated objects such as Gl 229B or SDSS 1624+0029.

  10. 7 CFR 42.110 - Sampling plans for tightened condition of container inspection; Tables II and II-A.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Inspection Code Lot size ranges—Number of containers in lot Type of plan AQL 0.15 Sample size Ac Re Sample size Other acceptable quality levels 0.25 Ac Re 0.50 Ac Re 1.0 Ac Re 1.5 Ac Re 2.5 Ac Re 4.0 Ac Re 6.5 Ac Re 10.0 Ac Re CB 6,000 or less Single 264 0 1 168 0 1 1 2 2 3 4 5 5 6 7 8 11 12 16 17 Double...

  11. A Confirmatory Factor Analysis of the California Verbal Learning Test-Second Edition (CVLT-II) in the Standardization Sample

    ERIC Educational Resources Information Center

    Donders, Jacobus

    2008-01-01

    The purpose of this study is to determine the latent structure of the California Verbal Learning Test-Second Edition (CVLT-II; Delis, Kramer, Kaplan, & Ober, 2000) at three different age levels, using the standardization sample. Maximum likelihood confirmatory factor analyses are performed to test four competing hypothetical models for fit and…

  12. Optimal blood sampling time windows for parameter estimation using a population approach: design of a phase II clinical trial.

    PubMed

    Chenel, Marylore; Ogungbenro, Kayode; Duval, Vincent; Laveille, Christian; Jochemsen, Roeline; Aarons, Leon

    2005-12-01

    The objective of this paper is to determine optimal blood sampling time windows for the estimation of pharmacokinetic (PK) parameters by a population approach within the clinical constraints. A population PK model was developed to describe a reference phase II PK dataset. Using this model and the parameter estimates, D-optimal sampling times were determined by optimising the determinant of the population Fisher information matrix (PFIM) using PFIM_ _M 1.2 and the modified Fedorov exchange algorithm. Optimal sampling time windows were then determined by allowing the D-optimal windows design to result in a specified level of efficiency when compared to the fixed-times D-optimal design. The best results were obtained when K(a) and IIV on K(a) were fixed. Windows were determined using this approach assuming 90% level of efficiency and uniform sample distribution. Four optimal sampling time windows were determined as follow: at trough between 22 h and new drug administration; between 2 and 4 h after dose for all patients; and for 1/3 of the patients only 2 sampling time windows between 4 and 10 h after dose, equal to [4 h-5 h 05] and [9 h 10-10 h]. This work permitted the determination of an optimal design, with suitable sampling time windows which was then evaluated by simulations. The sampling time windows will be used to define the sampling schedule in a prospective phase II study.

  13. Probing Receptor Specificity by Sampling the Conformational Space of the Insulin-like Growth Factor II C-domain*

    PubMed Central

    Hexnerová, Rozálie; Křížková, Květoslava; Fábry, Milan; Sieglová, Irena; Kedrová, Kateřina; Collinsová, Michaela; Ullrichová, Pavlína; Srb, Pavel; Williams, Christopher; Crump, Matthew P.; Tošner, Zdeněk; Jiráček, Jiří; Veverka, Václav; Žáková, Lenka

    2016-01-01

    Insulin and insulin-like growth factors I and II are closely related protein hormones. Their distinct evolution has resulted in different yet overlapping biological functions with insulin becoming a key regulator of metabolism, whereas insulin-like growth factors (IGF)-I/II are major growth factors. Insulin and IGFs cross-bind with different affinities to closely related insulin receptor isoforms A and B (IR-A and IR-B) and insulin-like growth factor type I receptor (IGF-1R). Identification of structural determinants in IGFs and insulin that trigger their specific signaling pathways is of increasing importance in designing receptor-specific analogs with potential therapeutic applications. Here, we developed a straightforward protocol for production of recombinant IGF-II and prepared six IGF-II analogs with IGF-I-like mutations. All modified molecules exhibit significantly reduced affinity toward IR-A, particularly the analogs with a Pro-Gln insertion in the C-domain. Moreover, one of the analogs has enhanced binding affinity for IGF-1R due to a synergistic effect of the Pro-Gln insertion and S29N point mutation. Consequently, this analog has almost a 10-fold higher IGF-1R/IR-A binding specificity in comparison with native IGF-II. The established IGF-II purification protocol allowed for cost-effective isotope labeling required for a detailed NMR structural characterization of IGF-II analogs that revealed a link between the altered binding behavior of selected analogs and conformational rearrangement of their C-domains. PMID:27510031

  14. A solid phase extraction procedure for the determination of Cd(II) and Pb(II) ions in food and water samples by flame atomic absorption spectrometry.

    PubMed

    Daşbaşı, Teslima; Saçmacı, Şerife; Ülgen, Ahmet; Kartal, Şenol

    2015-05-01

    A relatively rapid, accurate and precise solid phase extraction method is presented for the determination of cadmium(II) and lead(II) in various food and water samples. Quantitation is carried out by flame atomic absorption spectrometry (FAAS). The method is based on the retention of the trace metal ions on Dowex Marathon C, a strong acid cation exchange resin. Some important parameters affecting the analytical performance of the method such as pH, flow rate and volume of the sample solution; type, concentration, volume, flow rate of the eluent; and matrix effects on the retention of the metal ions were investigated. Common coexisting ions did not interfere on the separation and determination of the analytes. The detection limits (3 σb) for Cd(II) and Pb(II) were found as 0.13 and 0.18 μg L(-1), respectively, while the limit of quantification values (10 σb) were computed as 0.43 and 0.60 μg L(-1) for the same sequence of the analytes. The precision (as relative standard deviation was lower than 4% at 5 μg L(-1) Cd(II) and 10 μg L(-1) Pb(II) levels, and the preconcentration factor was found to be 250. The accuracy of the proposed procedure was verified by analysing the certified reference materials, SPS-WW2 Batch 108 wastewater level 2 and INCT-TL-1 tea leaves, with the satisfactory results. In addition, for the accuracy of the method the recovery studies (⩾ 95%) were carried out. The method was applied to the determination of the analytes in the various natural waters (lake water, tap water, waste water with boric acid, waste water with H2SO4) and food samples (pomegranate flower, organic pear, radish leaf, lamb meat, etc.), and good results were obtained. While the food samples almost do not contain cadmium, they have included lead at low levels of 0.13-1.12 μg g(-1). PMID:25529724

  15. Humidity-controlled preparation of frozen-hydrated biological samples for cryogenic coherent x-ray diffraction microscopy.

    PubMed

    Takayama, Yuki; Nakasako, Masayoshi

    2012-05-01

    Coherent x-ray diffraction microscopy (CXDM) has the potential to visualize the structures of micro- to sub-micrometer-sized biological particles, such as cells and organelles, at high resolution. Toward advancing structural studies on the functional states of such particles, here, we developed a system for the preparation of frozen-hydrated biological samples for cryogenic CXDM experiments. The system, which comprised a moist air generator, microscope, micro-injector mounted on a micromanipulator, custom-made sample preparation chamber, and flash-cooling device, allowed for the manipulation of sample particles in the relative humidity range of 20%-94%rh at 293 K to maintain their hydrated and functional states. Here, we report the details of the system and the operation procedure, including its application to the preparation of a frozen-hydrated chloroplast sample. Sample quality was evaluated through a cryogenic CXDM experiment conducted at BL29XUL of SPring-8. Taking the performance of the system and the quality of the sample, the system was suitable to prepare frozen-hydrated biological samples for cryogenic CXDM experiments.

  16. Humidity-controlled preparation of frozen-hydrated biological samples for cryogenic coherent x-ray diffraction microscopy

    SciTech Connect

    Takayama, Yuki; Nakasako, Masayoshi

    2012-05-15

    Coherent x-ray diffraction microscopy (CXDM) has the potential to visualize the structures of micro- to sub-micrometer-sized biological particles, such as cells and organelles, at high resolution. Toward advancing structural studies on the functional states of such particles, here, we developed a system for the preparation of frozen-hydrated biological samples for cryogenic CXDM experiments. The system, which comprised a moist air generator, microscope, micro-injector mounted on a micromanipulator, custom-made sample preparation chamber, and flash-cooling device, allowed for the manipulation of sample particles in the relative humidity range of 20%-94%rh at 293 K to maintain their hydrated and functional states. Here, we report the details of the system and the operation procedure, including its application to the preparation of a frozen-hydrated chloroplast sample. Sample quality was evaluated through a cryogenic CXDM experiment conducted at BL29XUL of SPring-8. Taking the performance of the system and the quality of the sample, the system was suitable to prepare frozen-hydrated biological samples for cryogenic CXDM experiments.

  17. Occurrence of aminoglycoside phosphotransferase subclass I and II structural genes among Enterobacteriaceae spp. isolated from meat samples.

    PubMed

    Jayaratne, A H; Collins-Thompson, D L; Trevors, J T

    1990-08-01

    3'-Aminoglycoside phosphotransferase [APH(3')] enzymes are a group responsible for resistance to the antibiotics kanamycin (Km) and neomycin (Nm) in bacteria. Escherichia coli ECT24, originally isolated from a meat sample, harboured an 83-kb conjugative R-plasmid (pRPJ24) that carries transferable resistance to Km and Nm. Plasmid pRPJ24 was transferred by conjugation to Enterobacter cloacae 94R, which was used as the source of plasmid DNA in development of a probe for the Km-resistance determinant. Random cloning of BamHI and HindIII double-digest restriction fragments of pRPJ24 in the pUC18 vector plasmid produced clones resistant to both Nm and Km carrying a 1.9-kb DNA insert. Southern hybridization of pRPJ24 cloned chimeric plasmid DNA (pKPJ94) showed homology with the APH(3')II gene from transposon Tn5. A PstI digest of pKPJ94 produced a 920-bp fragment which hybridized with the APH(3')II structural gene, and was used as a DNA probe for the APH(3')II subclass gene. A 980-bp BamHI fragment from plasmid pGH54 carrying the APH(3')I gene from transposon Tn903 was used as a subclass I probe. Total DNA from 206 randomly screened Km-resistant Enterobacteriaceae isolates from raw ground beef and chicken meat samples were examined for the occurrence of APH(3') subclass I and II using non-radioactively-labelled DNA probes. Thirty-six percent and 60% of the isolates examined carried subclass I and II resistances, respectively, in the isolates from chicken meat samples. The corresponding values for bacterial strains from raw ground beef samples were 51% and 72%, respectively. Four percent of the resistant bacterial isolates from chicken samples did not display homology to either probe.(ABSTRACT TRUNCATED AT 250 WORDS)

  18. Latest developments and opportunities for 3D analysis of biological samples by confocal μ-XRF

    NASA Astrophysics Data System (ADS)

    Perez, Roberto D.; Sánchez, Héctor J.; Perez, Carlos A.; Rubio, Marcelo

    2010-02-01

    X-ray fluorescence analysis performed with a primary radiation focused in the micrometer range is known as micro-X-ray fluorescence (μ-XRF). It is characterized by a penetration depth higher than other micro-analytical methods, reaching hundreds of micrometers in biological samples. This characteristic of the X-ray beam can be employed in 3D analysis. An innovative method to perform 3D analysis by μ-XRF is the so-called confocal setup. The confocal setup consists of X-ray lenses in the excitation as well as in the detection channel. In this configuration, a micro-volume defined by the overlap of the foci of both X-ray lenses is analyzed. Scanning this micro-volume through the sample can be used to perform a study in three dimensions. At present, X-ray lenses used in confocal μ-XRF experiments are mainly glass capillaries and polycapillaries. Glass capillaries are used in the excitation channel with sources of high photon flux like synchrotron radiation. Half polycapillaries or conical polycapillary concentrators are used almost exclusively in the detection channel. Spatial resolution of the confocal μ-XRF depends on the dimensions of the foci of both X-ray lenses. The overlap of these foci forms an ellipsoid which is the probing volume of the confocal setup. The axis length of the probing volume reported in confocal μ-XRF experiments are of order of few tens of micrometer. In our confocal setup, we used a commercial glass monocapillary in the excitation channel and a monolithic half polycapillary in the detection channel. The polycapillary was home-made by means of drawing of multibundles of glass capillaries in a heating furnace. The experiment was carried out at the beamline D09B-XRF of the Synchrotron Light National Laboratory (Laboratório Nacional de Luz Síncrotron, LNLS) using white beam. A model for the theoretical description of X-ray fluorescence intensity registered by confocal μ-XRF was introduced by Malzer and Kanngieβer [2005. A model for the

  19. Correlations among Five Variables and the Biology Performance of a Sample of Jamaican High School Students

    ERIC Educational Resources Information Center

    Blair-Walters, Shonette; Soyibo, Kola

    2004-01-01

    This study investigates whether or not (a) 252 Jamaican high school students (168 boys, 84 girls, 171 grade 10 and 81 grade 11 students) had favourable attitudes to biology, (b) their level of biology performance was satisfactory, (c) there were significant differences in their performance based on their gender, grade level, school-type,…

  20. Accelerator mass spectrometry analysis of 14C-oxaliplatin concentrations in biological samples and 14C contents in biological samples and antineoplastic agents

    NASA Astrophysics Data System (ADS)

    Toyoguchi, Teiko; Kobayashi, Takeshi; Konno, Noboru; Shiraishi, Tadashi; Kato, Kazuhiro; Tokanai, Fuyuki

    2015-10-01

    Accelerator mass spectrometry (AMS) is expected to play an important role in microdose trials. In this study, we measured the 14C concentration in 14C-oxaliplatin-spiked serum, urine and supernatant of fecal homogenate samples in our Yamagata University (YU) - AMS system. The calibration curves of 14C concentration in serum, urine and supernatant of fecal homogenate were linear (the correlation coefficients were ⩾0.9893), and the precision and accuracy was within the acceptance criteria. To examine a 14C content of water in three vacuum blood collection tubes and a syringe were measured. 14C was not detected from water in these devices. The mean 14C content in urine samples of 6 healthy Japanese volunteers was 0.144 dpm/mL, and the intra-day fluctuation of 14C content in urine from a volunteer was little. The antineoplastic agents are administered to the patients in combination. Then, 14C contents of the antineoplastic agents were quantitated. 14C contents were different among 10 antineoplastic agents; 14C contents of paclitaxel injection and docetaxel hydrate injection were higher than those of the other injections. These results indicate that our quantitation method using YU-AMS system is suited for microdosing studies and that measurement of baseline and co-administered drugs might be necessary for the studies in low concentrations.

  1. Optimization of microwave digestion for mercury determination in marine biological samples by cold vapour atomic absorption spectrometry.

    PubMed

    Cardellicchio, Nicola; Di Leo, Antonella; Giandomenico, Santina; Santoro, Stefania

    2006-01-01

    Optimization of acid digestion method for mercury determination in marine biological samples (dolphin liver, fish and mussel tissues) using a closed vessel microwave sample preparation is presented. Five digestion procedures with different acid mixtures were investigated: the best results were obtained when the microwave-assisted digestion was based on sample dissolution with HNO3-H2SO4-K2Cr2O7 mixture. A comparison between microwave digestion and conventional reflux digestion shows there are considerable losses of mercury in the open digestion system. The microwave digestion method has been tested satisfactorily using two certified reference materials. Analytical results show a good agreement with certified values. The microwave digestion proved to be a reliable and rapid method for decomposition of biological samples in mercury determination.

  2. Ca II AND Na I QUASAR ABSORPTION-LINE SYSTEMS IN AN EMISSION-SELECTED SAMPLE OF SDSS DR7 GALAXY/QUASAR PROJECTIONS. I. SAMPLE SELECTION

    SciTech Connect

    Cherinka, B.; Schulte-Ladbeck, R. E.

    2011-10-15

    The aim of this project is to identify low-redshift host galaxies of quasar absorption-line systems by selecting galaxies that are seen in projection onto quasar sightlines. To this end, we use the Seventh Data Release of the Sloan Digital Sky Survey to construct a parent sample of 97,489 galaxy/quasar projections at impact parameters of up to 100 kpc to the foreground galaxy. We then search the quasar spectra for absorption-line systems of Ca II and Na I within {+-}500 km s{sup -1} of the galaxy's velocity. This yields 92 Ca II and 16 Na I absorption systems. We find that most of the Ca II and Na I systems are sightlines through the Galactic disk, through high-velocity cloud complexes in our halo, or Virgo Cluster sightlines. Placing constraints on the absorption line rest equivalent width significance ({>=}3.0{sigma}), the local standard of rest velocity along the sightline ({>=}345 km s{sup -1}), and the ratio of the impact parameter to the galaxy optical radius ({<=}5.0), we identify four absorption-line systems that are associated with low-redshift galaxies at high confidence, consisting of two Ca II systems (one of which also shows Na I) and two Na I systems. These four systems arise in blue, {approx}L*{sub r} galaxies. Tables of the 108 absorption systems are provided to facilitate future follow-up.

  3. Development of a multi-component chemically reactive detection conjugate for the determination of Hg(II) in water samples.

    PubMed

    Zhou, Yu; Tian, Xiang-Li; Li, Yan-Song; Zhang, Yuan-Yuan; Li, Zhao-Hui; Yang, Li; Zhang, Jun-Hui; Wang, Xin-Rui; Meng, Xian-Mei; Liu, Jing-Qiu

    2012-04-29

    Mercury ions (Hg(II)) are considered highly toxic and hazardous element even at low levels. The contamination of Hg(II) is a global problem. To develop selective and sensitive technique for the detection of Hg(II) has attracted considerable attention. In this study, a multi-component chemically reactive detection conjugate for determination of Hg(II) has been synthesized and a competitive format assay was proposed. In the technique, the chemically reactive capture conjugate was coated on the plate. The reactive detection conjugate was then captured by the capture conjugate. TMB solution was added and catalyzed by HRP molecules immobilized on AuNPs. Finally, the developed enzymatic signal was measured at 450 nm. The linear range of the assay was 0.35-350 ppb with a detection limit of 0.1 ppb. The average recoveries of Hg(II) from mineral water, tap water and lake water were 100.03%, 103.13% and 102.03%, respectively. All coefficients of variation (CVs) were less than 10%. The results are closely correlated with those from inductively coupled plasma mass spectrometry (ICP-MS), which indicated that the developed technique is a reliable method for and sensitive detection of Hg(II) in water samples.

  4. Development of a multi-component chemically reactive detection conjugate for the determination of Hg(II) in water samples.

    PubMed

    Zhou, Yu; Tian, Xiang-Li; Li, Yan-Song; Zhang, Yuan-Yuan; Li, Zhao-Hui; Yang, Li; Zhang, Jun-Hui; Wang, Xin-Rui; Meng, Xian-Mei; Liu, Jing-Qiu

    2012-04-29

    Mercury ions (Hg(II)) are considered highly toxic and hazardous element even at low levels. The contamination of Hg(II) is a global problem. To develop selective and sensitive technique for the detection of Hg(II) has attracted considerable attention. In this study, a multi-component chemically reactive detection conjugate for determination of Hg(II) has been synthesized and a competitive format assay was proposed. In the technique, the chemically reactive capture conjugate was coated on the plate. The reactive detection conjugate was then captured by the capture conjugate. TMB solution was added and catalyzed by HRP molecules immobilized on AuNPs. Finally, the developed enzymatic signal was measured at 450 nm. The linear range of the assay was 0.35-350 ppb with a detection limit of 0.1 ppb. The average recoveries of Hg(II) from mineral water, tap water and lake water were 100.03%, 103.13% and 102.03%, respectively. All coefficients of variation (CVs) were less than 10%. The results are closely correlated with those from inductively coupled plasma mass spectrometry (ICP-MS), which indicated that the developed technique is a reliable method for and sensitive detection of Hg(II) in water samples. PMID:22483216

  5. A Promising Raman Spectroscopy Technique for the Investigation of trans and cis Cholesteryl Ester Isomers in Biological Samples.

    PubMed

    Melchiorre, Michele; Ferreri, Carla; Tinti, Anna; Chatgilialoglu, Chryssostomos; Torreggiani, Armida

    2015-05-01

    Lipid geometry is an important issue in biology and medicine. The cis-trans geometry conversion of double bonds in lipids is an endogenous process that can be mediated by sulfur-centered free radicals. Trans isomers of polyunsaturated fatty acids can be used as biological markers of free radical stress, and their presence in biological samples can be determined by synthesis and characterization of appropriate reference compounds. Fractions of plasma lipids, such as cholesteryl linoleate and arachidonate esters, are interesting targets because of their connection with membrane phospholipid turnover and their roles in cardiovascular health. In this context, Raman spectroscopy can provide a useful contribution, since Raman analysis can be performed directly on the lipid extracts without any derivatization reaction, is nondestructive, and can rapidly supply biochemical information. This study focused on the build up of Raman spectral libraries of different cis and trans isomers of cholesteryl esters to be used as references for the examination of complex biological samples and to facilitate isomer recognition. Unsaturated cholesteryl esters obtained by chemical synthesis and with different alkyl chain lengths, double bond numbers, or both, were analyzed. The potential of Raman analysis for trans isomer detection in biological samples was successfully tested on some cholesteryl ester lipid fractions from human serum. The data suggest promising applications of Raman spectroscopy in metabolomics and lipidomics.

  6. Development of a biaxial compression device for biological samples: preliminary experimental results for a closed cell foam.

    PubMed

    Little, J P; Tevelen, G; Adam, C J; Evans, J H; Pearcy, M J

    2009-07-01

    Biological tissues are subjected to complex loading states in vivo and in order to define constitutive equations that effectively simulate their mechanical behaviour under these loads, it is necessary to obtain data on the tissue's response to multiaxial loading. Single axis and shear testing of biological tissues is often carried out, but biaxial testing is less common. We sought to design and commission a biaxial compression testing device, capable of obtaining repeatable data for biological samples. The apparatus comprised a sealed stainless steel pressure vessel specifically designed such that a state of hydrostatic compression could be created on the test specimen while simultaneously unloading the sample along one axis with an equilibrating tensile pressure. Thus a state of equibiaxial compression was created perpendicular to the long axis of a rectangular sample. For the purpose of calibration and commissioning of the vessel, rectangular samples of closed cell ethylene vinyl acetate (EVA) foam were tested. Each sample was subjected to repeated loading, and nine separate biaxial experiments were carried out to a maximum pressure of 204 kPa (30 psi), with a relaxation time of two hours between them. Calibration testing demonstrated the force applied to the samples had a maximum error of 0.026 N (0.423% of maximum applied force). Under repeated loading, the foam sample demonstrated lower stiffness during the first load cycle. Following this cycle, an increased stiffness, repeatable response was observed with successive loading. While the experimental protocol was developed for EVA foam, preliminary results on this material suggest that this device may be capable of providing test data for biological tissue samples. The load response of the foam was characteristic of closed cell foams, with consolidation during the early loading cycles, then a repeatable load-displacement response upon repeated loading. The repeatability of the test results demonstrated the

  7. Critical tests for determination of microbiological quality and biological activity in commercial vermicompost samples of different origins.

    PubMed

    Grantina-Ievina, Lelde; Andersone, Una; Berkolde-Pīre, Dace; Nikolajeva, Vizma; Ievinsh, Gederts

    2013-12-01

    The aim of the present paper was to show that differences in biological activity among commercially produced vermicompost samples can be found by using a relatively simple test system consisting of microorganism tests on six microbiological media and soilless seedling growth tests with four vegetable crop species. Significant differences in biological properties among analyzed samples were evident both at the level of microbial load as well as plant growth-affecting activity. These differences were mostly manufacturer- and feedstock-associated, but also resulted from storage conditions of vermicompost samples. A mature vermicompost sample that was produced from sewage sludge still contained considerable number of Escherichia coli. Samples from all producers contained several potentially pathogenic fungal species such as Aspergillus fumigatus, Pseudallescheria boidii, Pseudallescheria fimeti, Pseudallescheria minutispora, Scedosporium apiospermum, Scedosporium prolificans, Scopulariopsis brevicaulis, Stachybotrys chartarum, Geotrichum spp., Aphanoascus terreus, and Doratomyces columnaris. In addition, samples from all producers contained plant growth-promoting fungi from the genera Trichoderma and Mortierella. The described system can be useful both for functional studies aiming at understanding of factors affecting quality characteristics of vermicompost preparations and for routine testing of microbiological quality and biological activity of organic waste-derived composts and vermicomposts.

  8. 2,4-Dinitrophenylhydrazine functionalized sodium dodecyl sulfate-coated magnetite nanoparticles for effective removal of Cd(II) and Ni(II) ions from water samples.

    PubMed

    Sobhanardakani, Soheil; Zandipak, Raziyeh

    2015-07-01

    2,4-Dinitrophenylhydrazine immobilized on sodium dodecyl sulfate (SDS)-coated magnetite and was used for removal of Cd(II) and Ni(II) ions from aqueous solution. The prepared product was characterized by X-ray diffraction (XRD) analysis, Fourier transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM). The size of the nanoparticles according to SEM was obtained around 20-35 nm. In batch tests, the effects of pH, contact time, initial metal concentration, and temperature were studied. The kinetic and equilibrium data were modeled with recently developed models. The adsorption kinetics and isotherms were well fitted by the fractal-like pseudo-second-order model and Langmuir-Freundlich model, respectively. Maximum adsorption capacity by this adsorbent is 255.1 mg g(-1) for Cd(II) ion and 319.6 mg g(-1) for Ni(II) ion at pH 7.0 and 25 °C. The method was successfully applied to the removal of metal cations in real samples (tap water, river water, and petrochemical wastewater).

  9. Solid phase synthesis of somatostatin-28 II. A new biologically active octacosapeptide from anglerfish pancreatic islets.

    PubMed

    Nicolas, P; Delfour, A; Boussetta, H; Morel, A; Rholam, M; Cohen, P

    1986-10-30

    Somatostatin-28 II, an octacosapeptide recently isolated from anglerfish pancreatic islets, was synthetized by the solid phase method along with its somatostatin-14 II and somatostatin-28 II-(1-12) corresponding domains. Homogeneity of the synthetic peptides was demonstrated by analytical RP-HPLC, thin layer chromatography and electrophoresis. The peptides were further characterized by amino acids analysis, fast atomic bombarding mass spectrometry and/or 252Cf plasma desorption mass spectrometry. Synthetic somatostatin-28 II and somatostatin-14 II displace equally well the potent agonist (Tyr0,D-Trp8)-somatostatin-14 from its specific binding sites on anterior pituitary cells membranes. Both peptides activate adenylate cyclase from dispersed rat anterior pituitary cells. PMID:2877662

  10. New Methods of Simulation of Mn(II) EPR Spectra: Single Crystals, Polycrystalline and Amorphous (Biological) Materials

    NASA Astrophysics Data System (ADS)

    Misra, Sushil K.

    Biological systems exhibit properties of amorphous materials. The Mn(II) ion in amorphous materials is characterized by distributions of spin-Hamiltonian parameters around mean values. It has a certain advantage over other ions, being one of the most abundant elements on the earth. The extent to which living organisms utilize manganese varies from one organism to the other. There is a fairly high concentration of the Mn(II) ion in green plants, which use it in the O2 evolution reaction of photosynthesis (Sauer, 1980). Structure-reactivity relationships in Mn(II)-O2 complexes are given in a review article by Coleman and Taylor (1980). Manganese is a trace requirement in animal nutrition; highly elevated levels of manganese in the diet can be toxic, probably because of an interference with iron homeostasis (Underwood, 1971). On the other hand, animals raised with a dietary deficiency of manganese exhibit severe abnormalities in connective tissue; these problems have been attributed to the obligatory role of Mn(II) in mucopolysaccharide metabolism (Leach, 1971). Mn(II) has been detected unequivocally in living organisms.

  11. Hybrid random walk-linear discriminant analysis method for unwrapping quantitative phase microscopy images of biological samples

    PubMed Central

    Kim, Diane N. H.; Teitell, Michael A.; Reed, Jason; Zangle, Thomas A.

    2015-01-01

    Abstract. Standard algorithms for phase unwrapping often fail for interferometric quantitative phase imaging (QPI) of biological samples due to the variable morphology of these samples and the requirement to image at low light intensities to avoid phototoxicity. We describe a new algorithm combining random walk-based image segmentation with linear discriminant analysis (LDA)-based feature detection, using assumptions about the morphology of biological samples to account for phase ambiguities when standard methods have failed. We present three versions of our method: first, a method for LDA image segmentation based on a manually compiled training dataset; second, a method using a random walker (RW) algorithm informed by the assumed properties of a biological phase image; and third, an algorithm which combines LDA-based edge detection with an efficient RW algorithm. We show that the combination of LDA plus the RW algorithm gives the best overall performance with little speed penalty compared to LDA alone, and that this algorithm can be further optimized using a genetic algorithm to yield superior performance for phase unwrapping of QPI data from biological samples. PMID:26305212

  12. Interaction between selenium and mercury in biological samples of Pakistani myocardial infarction patients at different stages as related to controls.

    PubMed

    Afridi, Hassan Imran; Kazi, Tasneem Gul; Talpur, Farah Naz; Kazi, Atif; Arain, Sadaf Sadia; Arain, Salma Aslam; Brahman, Kapil Dev; Panhwar, Abdul Haleem; Naeemullah

    2014-05-01

    It has been speculated that trace elements may a play role in the pathogenesis of heart diseases. In the present study, we aimed to assess the levels of selenium (Se) and mercury (Hg) in biological samples (whole blood, urine, and scalp hair) of myocardial infarction (MI) patients of both genders (age range 45-60 years) at the first, second, and third heart attack (n = 130), hospitalized in a cardiac ward of a civil hospital of Hyderabad City (Pakistan). For comparison, healthy age-matched referent subjects (n = 61) of both genders were also selected. Se and Hg in biological samples were measured by electrothermal atomic absorption spectrometry and cold vapor atomic absorption spectrometry, prior to microwave acid digestion, respectively. The validity of the methodology was checked by biological certified reference materials. During this study, 78 % of the 32 registered patients of third MI attack (aged >50 years) died. The concentration of Se was decreased in scalp hair and blood samples of MI patients, while Hg was higher in all biological samples as compared to referent subjects. Se concentration was inversely associated with the risk of MI attacks in both genders. These results add to an increasing body of evidence that Se is a protective element for cardiovascular health. PMID:24643467

  13. Label-free visual detection of nucleic acids in biological samples with single-base mismatch detection capability.

    PubMed

    Song, Yanling; Zhang, Weiting; An, Yuan; Cui, Liang; Yu, Chundong; Zhu, Zhi; Yang, Chaoyong James

    2012-01-14

    We have combined an allosteric molecular beacon for target recognition and guanine-rich DNAzyme for signal amplification to develop a new platform for visual detection of nucleic acids with single-base mismatch detection capability. The fully DNA-structured platform can undergo color change in response to target DNA/RNA, which enables sensitive and selective visual detection in biological samples.

  14. Socioeconomic Status and School Grades: Placing Their Association in Broader Context in a Sample of Biological and Adoptive Families

    ERIC Educational Resources Information Center

    Johnson, Wendy; McGue, Matt; Iacono, William G.

    2007-01-01

    SES has long interested researchers investigating school achievement. Its effects are often addressed by studying predictors of achievement in economically disadvantaged samples living primarily in biological families, confounding genetic and environmental influences. Little is known about SES's purely environmental effects. We measured them in…

  15. Analysis of apoB and apoC-II gene polymorphism in random sample and CHD patients from Moscow

    SciTech Connect

    Pogoda, T.V.; Nikonova, A.; Perova, N.V.

    1994-09-01

    We have analyzed the allele frequency distributions of the 3{prime} apoB gene minisatellite and apoC-II gene microsatellite in random sample of coronary heart disease (CHD) patients. For this purpose we used the PCR technique followed by high-resolution PAGE. It was revealed that the apoB allele, harboring 30 repeats (apoB 30), as well as the apoC-II allele harboring 30 repeats (apoC-II 30), were less frequent in patients at the same time as the frequency of the apoB 32 and apoC-II 17 alleles was greater in patients. The greater frequency of apoB alleles which were larger in size than apoB 46 (defined as `long` - L) was observed in patients with high apoB levels (>160mg dl). The analysis of apoB genotype distribution showed that in a random sample the most common genotype was apoB 34,36 (a combination of the most frequent alleles in the random sample). In patients with high apoB levels, it was twice less frequent, and the most common genotype was apoB 36,L (43% versus 12% in the random sample). Analysis of data on a lipid spectrum of subjects from the random sample with different apoB and apoC-II 17 alleles were associated with atherogenic shifts in the lipid profile, at the same time as apoB 30 and apoC-II 30 alleles - with an apparently favorable lipid profile. The increment of the disease-related risk was observed for subjects with a combination of apoB 32 allele or apoB 36,L genotype with the apoC-11 17 allele. Alternatively, combination of these apoB variants with the apoC-II 30 allele resulted in decreased related risk. In conclusion, simultaneous analysis of two candidate gene variants demonstrated interaction in their influence on the lipid spectrum.

  16. Selective ionic liquid ferrofluid based dispersive-solid phase extraction for simultaneous preconcentration/separation of lead and cadmium in milk and biological samples.

    PubMed

    Fasih Ramandi, Negin; Shemirani, Farzaneh

    2015-01-01

    For the first time, a selective ionic liquid ferrofluid has been used in dispersive solid phase extraction (IL-FF-D-SPE) for simultaneous preconcentration and separation of lead and cadmium in milk and biological samples combined with flame atomic absorption spectrometry. To improve the selectivity of the ionic liquid ferrofluid, the surface of TiO2 nanoparticles with a magnetic core as sorbent was modified by loading 1-(2-pyridylazo)-2-naphtol. Due to the rapid injection of an appropriate amount of ionic liquid ferrofluid into the aqueous sample by a syringe, extraction can be achieved within a few seconds. In addition, based on the attraction of the ionic liquid ferrofluid to a magnet, no centrifugation step is needed for phase separation. The experimental parameters of IL-FF-D-SPE were optimized using a Box-Behnken design (BBD) after a Plackett-Burman screening design. Under the optimum conditions, the relative standard deviations of 2.2% and 2.4% were obtained for lead and cadmium, respectively (n=7). The limit of detections were 1.21 µg L(-1) for Pb(II) and 0.21 µg L(-1) for Cd(II). The preconcentration factors were 250 for lead and 200 for cadmium and the maximum adsorption capacities of the sorbent were 11.18 and 9.34 mg g(-1) for lead and cadmium, respectively. PMID:25281121

  17. Synthesis, characterization, biological activity of binuclear Co(II), Cu(II) and mononuclear Ni(II) complexes of bulky multi-dentate thiosemicarbazide

    NASA Astrophysics Data System (ADS)

    El-Gammal, O. A.; Abd Al-Gader, I. M.; El-Asmy, A. A.

    2014-07-01

    The chelation behavior of 9,10-dihydro-9,10-ethanoanthracene-11,12-dicarbonyl) bis (N-ethylhydrazine-1-carbothioamide) (H6ETS)(1) towards Co2+, Ni2+and Cu2+ have been studied. The spectral data revealed that the ligand acts as a bi- and/or mono-negative multi-dentate. The isolated Ni(II) and Cu(II) complexes are square-planar while the Co(II) is tetrahedral. EPR spectrum of Cu(II) complex confirmed simulated an axial spin-Hamiltonian exhibiting a four-line pattern with nitrogen super-hyperfine couplings originating from imine hydrazinic nitrogen atoms and possess a significant amount of tetrahedral distortion leading to a pseudo-square-planar geometry with unpaired electron has d ground state. Also, the thermal behavior and kinetic parameters were determined. Furthermore, the title compounds were investigated for their antibacterial activity using inhibition zone diameter and for DNA degradation, superoxide-scavenging activity as well as hydroxyl radicals that generated by the oxidation of cytochrome c in L-ascorbic acid/CuSO4-cytochrome c system.

  18. State of the art of environmentally friendly sample preparation approaches for determination of PBDEs and metabolites in environmental and biological samples: A critical review.

    PubMed

    Berton, Paula; Lana, Nerina B; Ríos, Juan M; García-Reyes, Juan F; Altamirano, Jorgelina C

    2016-01-28

    Green chemistry principles for developing methodologies have gained attention in analytical chemistry in recent decades. A growing number of analytical techniques have been proposed for determination of organic persistent pollutants in environmental and biological samples. In this light, the current review aims to present state-of-the-art sample preparation approaches based on green analytical principles proposed for the determination of polybrominated diphenyl ethers (PBDEs) and metabolites (OH-PBDEs and MeO-PBDEs) in environmental and biological samples. Approaches to lower the solvent consumption and accelerate the extraction, such as pressurized liquid extraction, microwave-assisted extraction, and ultrasound-assisted extraction, are discussed in this review. Special attention is paid to miniaturized sample preparation methodologies and strategies proposed to reduce organic solvent consumption. Additionally, extraction techniques based on alternative solvents (surfactants, supercritical fluids, or ionic liquids) are also commented in this work, even though these are scarcely used for determination of PBDEs. In addition to liquid-based extraction techniques, solid-based analytical techniques are also addressed. The development of greener, faster and simpler sample preparation approaches has increased in recent years (2003-2013). Among green extraction techniques, those based on the liquid phase predominate over those based on the solid phase (71% vs. 29%, respectively). For solid samples, solvent assisted extraction techniques are preferred for leaching of PBDEs, and liquid phase microextraction techniques are mostly used for liquid samples. Likewise, green characteristics of the instrumental analysis used after the extraction and clean-up steps are briefly discussed. PMID:26755134

  19. Microwave digestion using dual PTFE containers for analysis of trace elements in small amounts of biological samples.

    PubMed

    Mizushima, R; Yonezawa, M; Ejima, A; Koyama, H; Satoh, H

    1996-01-01

    The analysis of trace elements in biological samples is essential to extend our knowledge on human health and disease. Inductively coupled plasma mass spectrometry (ICP-MS) makes it possible to simultaneously determine these elements in trace amounts. Before analysis, however, biological samples such as organs and tissues must be liquefied and extra organic materials must be decomposed by acid digestion. We established a method of microwave digestion using dual PTFE containers to minimize the amount of samples. Samples (35-45 mg) of standard reference materials, bovine liver (1577a, NIST) and fish flesh (MA-A-2, IAEA), were weighed in PTFE-PFA vials and a small amount of nitric acid (0.5 ml) was added. The vials were sealed and two PTFE-PFA vials were placed in a PTFE-TFM vessel containing 6 ml of pure water. Then the vessels were placed in a rotor and the samples were digested for 38 min in a microwave oven according to a pre-set program. After the program was completed, the samples were analyzed by ICP-MS. The determined values of elements of the microwave-digested samples matched the certified values of the standard reference materials. Therefore, the digestion using dual containers was successfully applied to small samples.

  20. Standard Reporting Requirements for Biological Samples in Metabolomics Experiments: Environmental Context

    EPA Science Inventory

    Metabolomic technologies are increasingly being applied to study biological questions in a range of different settings from clinical through to environmental. As with other high-throughput technologies, such as those used in transcriptomics and proteomics, metabolomics continues...

  1. Estimation of calcium, magnesium, cadmium, and lead in biological samples from paralyzed quality control and production steel mill workers.

    PubMed

    Afridi, Hassan Imran; Talpur, Farah Naz; Kazi, Tasneem Gul; Kazi, Naveed; Arain, Sadaf Sadia; Shah, Faheem

    2015-06-01

    The determination of trace and toxic metals in the biological samples of human beings is an important clinical screening procedure. The aim of the present study was to compare the level of essential trace and toxic elements cadmium (Cd), calcium (Ca), lead (Pb), and magnesium (Mg) in biological samples (whole blood, urine, and scalp hair) of male paralyzed production (PPW) and quality control workers (PQW) of a steel mill, age ranged (35-55 years). For comparison purposes, healthy age-matched exposed referent subjects (EC), working in steel mill and control subjects (NEC), who were not working in industries and lived far away from the industrial areas, were selected as control subjects. The concentrations of electrolytes and toxic elements in biological samples were measured by atomic absorption spectrometry after microwave-assisted acid digestion. The validity and accuracy of the methodology were checked using certified reference materials. The results of this study showed that the mean values of Cd and Pb were significantly higher in scalp hair, blood, and urine samples of PPW and PQW as compared to NEC and EC (p < 0.001), whereas the concentrations of Ca and Mg were found to be lower in the scalp hair and blood but higher in the urine samples of PPW and PQW. The results show the need for immediate improvements in workplace, ventilation, and industrial hygiene practices.

  2. Australian Biology Test Item Bank, Years 11 and 12. Volume II: Year 12.

    ERIC Educational Resources Information Center

    Brown, David W., Ed.; Sewell, Jeffrey J., Ed.

    This document consists of test items which are applicable to biology courses throughout Australia (irrespective of course materials used); assess key concepts within course statement (for both core and optional studies); assess a wide range of cognitive processes; and are relevant to current biological concepts. These items are arranged under…

  3. Biology Labs That Work: The Best of How-To-Do-Its. Volume II.

    ERIC Educational Resources Information Center

    Black, Suzanne, Ed.; Moore, Randy, Ed.; Haugen, Heidi, Ed.

    This selected collection of How-To-Do-It articles published in the American Biology Teacher during the past six years presents experiments that can be conducted safely under properly trained and responsible teacher supervision. Contents include: (1) "General Biology and the Nature of Science"; (2) "Cells and Molecules"; (3) "Microbes and Fungi";…

  4. BASIC Simulation Programs; Volumes I and II. Biology, Earth Science, Chemistry.

    ERIC Educational Resources Information Center

    Digital Equipment Corp., Maynard, MA.

    Computer programs which teach concepts and processes related to biology, earth science, and chemistry are presented. The seven biology problems deal with aspects of genetics, evolution and natural selection, gametogenesis, enzymes, photosynthesis, and the transport of material across a membrane. Four earth science problems concern climates, the…

  5. The bank of biological samples representing individuals exposed to long-term ionizing radiation at various doses.

    PubMed

    Takhauov, Ravil M; Karpov, Andrey B; Albach, Elena N; Khalyuzova, Maria V; Freidin, Maxim B; Litviakov, Nicolai V; Sazonov, Aleksey E; Isubakova, Daria S; Bolshakov, Mikhail A; Mezheritskiy, Stanislav A; Mironova, Elena B; Semenova, Julia V; Nekrasov, Gennadiy B; Izosimov, Andrey S; Gagarin, Aleksey A; Brendakov, Roman V; Maksimov, Dmitriy E; Ermolaev, Yuriy D

    2015-04-01

    Collection and storage of biological specimens in biobanks aims to obtain and preserve samples of different kinds for biological and medical studies. Here we present a description of the Bank of Biological Materials (BBM) housed by the Seversk Biophysical Research Centre (SBRC; Seversk, Russia). The main goal of maintaining the BBM is to collect and store biological samples suitable for genetic studies of people exposed to long-term ionizing radiation. Currently, the collection includes 19,194 biological specimens obtained from 8105 donors, of whom 42.3% are diagnosed with malignant neoplasms, 28.7% are healthy residents of the city of Seversk, 18.8% are healthy employees of the Siberian Group of Chemical Enterprises (SGCE), and 10.2% are patients diagnosed with acute myocardial infarction. The donors were enrolled using the Regional Medical and Dosimetric Register database created by the SBRC. For each donor, DNA specimens were extracted from peripheral blood and tissues and cell suspensions for cytogenetic analysis were prepared routinely. The BBM's unique collection is suitable primarily for studies of individual radiosensitivity of humans (IRH), and genetic aspects of the pathophysiology of common human diseases, especially in populations exposed to long-term low-dose ionizing radiation.

  6. Cloud point extraction, preconcentration and spectrophotometric determination of trace amount of manganese(II) in water and food samples.

    PubMed

    Gouda, Ayman A

    2014-10-15

    A new cloud point extraction (CPE) process using the nonionic surfactant Triton X-114 to extract manganese(II) from aqueous solution was investigated. The method is based on the complexation reaction of manganese(II) with 1,2,5,8-tetrahydroxyanthracene-9,10-dione (quinalizarin) in the presence of borate buffer at pH 8.5 and micelle-mediated extraction of the complex. The enriched analyte in the surfactant-rich phase was determined by spectrophotometry at 528nm. The optimal extraction and reaction conditions (e.g. pH, reagent and surfactant concentrations, temperature and centrifugation times) were evaluated and optimized. Under the optimized experimental conditions, the analytical characteristics of the method (e.g., limit of detection (LOD), linear range, preconcentration and improvement factors) were obtained. The proposed CPE method showed linear calibration within the range 5.0-200ngmL(-1) of manganese(II) and the limit of detection of the method was 0.8ngmL(-1) with an preconcentration factor of ∼50 when 25mL of sample solution was preconcentrated to 0.5mL. The relative standard deviation (RSD) and relative error were found to be 1.35% and 1.42%, respectively (CMn(II)=150ngmL(-1), n=6) for pure standard solutions. The interference effect of some cations and anions was also studied. In the presence of foreign ions, no significant interference was observed. The method was applied to the determination of manganese(II) in water and food samples with a recovery for the spiked samples in the range of 95.87-102.5%.

  7. Cloud point extraction, preconcentration and spectrophotometric determination of trace amount of manganese(II) in water and food samples

    NASA Astrophysics Data System (ADS)

    Gouda, Ayman A.

    2014-10-01

    A new cloud point extraction (CPE) process using the nonionic surfactant Triton X-114 to extract manganese(II) from aqueous solution was investigated. The method is based on the complexation reaction of manganese(II) with 1,2,5,8-tetrahydroxyanthracene-9,10-dione (quinalizarin) in the presence of borate buffer at pH 8.5 and micelle-mediated extraction of the complex. The enriched analyte in the surfactant-rich phase was determined by spectrophotometry at 528 nm. The optimal extraction and reaction conditions (e.g. pH, reagent and surfactant concentrations, temperature and centrifugation times) were evaluated and optimized. Under the optimized experimental conditions, the analytical characteristics of the method (e.g., limit of detection (LOD), linear range, preconcentration and improvement factors) were obtained. The proposed CPE method showed linear calibration within the range 5.0-200 ng mL-1 of manganese(II) and the limit of detection of the method was 0.8 ng mL-1 with an preconcentration factor of ∼50 when 25 mL of sample solution was preconcentrated to 0.5 mL. The relative standard deviation (RSD) and relative error were found to be 1.35% and 1.42%, respectively (CMn(II) = 150 ng mL-1, n = 6) for pure standard solutions. The interference effect of some cations and anions was also studied. In the presence of foreign ions, no significant interference was observed. The method was applied to the determination of manganese(II) in water and food samples with a recovery for the spiked samples in the range of 95.87-102.5%.

  8. Cu(II) coordination chemistry of patellamide derivatives: possible biological functions of cyclic pseudopeptides.

    PubMed

    Comba, Peter; Dovalil, Nina; Gahan, Lawrence R; Haberhauer, Gebhard; Hanson, Graeme R; Noble, Christopher J; Seibold, Björn; Vadivelu, Prabha

    2012-02-27

    Two synthetic derivatives of the naturally occurring cyclic pseudooctapeptides patellamide  A-F and ascidiacyclamide, that is, H(4)pat(2), H(4)pat(3), as well as their Cu(II) complexes are described. These cyclic peptide derivatives differ from the naturally occurring macrocycles by the variation of the incorporated heterocyclic donor groups and the configuration of the amino acids connecting the heterocycles. The exchange of the oxazoline and thiazole groups by dimethylimidazoles or methyloxazoles leads to more rigid macrocycles, and the changes in the configuration of the side chains leads to significant differences in the folding of the cyclic peptides. These variations allow a detailed study of the various possible structural changes on the chemistry of the Cu(II) complexes formed. The coordination of Cu(II) with these macrocyclic species was monitored by high-resolution electrospray mass spectrometry (ESI-MS), spectrophotometric (UV/Vis) and circular dichroic (CD) titrations, and electron paramagnetic resonance (EPR) spectroscopy. Density functional theory (DFT) calculations and molecular mechanics (MM) simulations have been used to model the structures of the Cu(II) complexes and provide a detailed understanding of their geometric preferences and conformational flexibility. This is related to the Cu(II) coordination chemistry and the reactivity of the dinuclear Cu(II) complexes towards CO(2) fixation. The variation observed between the natural and various synthetic peptide systems enables conclusions about structure-reactivity correlations, and our results also provide information on why nature might have chosen oxazolines and thiazoles as incorporated heterocycles.

  9. Teaching about World War II: An ERIC/ChESS Sample.

    ERIC Educational Resources Information Center

    Schlene, Vickie L.

    1991-01-01

    Presents nine documents from the ERIC database dealing with teaching about World War II. Includes articles addressing the lessons of Pearl Harbor, the Holocaust, the wartime internment of Japanese Americans, industry's response to the war, and the moral lessons of Nazism. (SG)

  10. Authentic Instruction in Laptop Classrooms: Sample Lessons that Integrate Type II Applications

    ERIC Educational Resources Information Center

    Barron, Ann E.; Harmes, J. Christine

    2006-01-01

    Laptop computers and Type II applications can provide powerful tools for elementary classrooms, especially if they are combined with authentic instruction. This article provides information and lessons learned from a laptop initiative in an urban elementary school. The goal of the initiative was to develop lesson plans and document techniques that…

  11. 46 CFR Appendix II to Part 390 - Sample Capital Construction Fund Agreement

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... II to Part 390 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION REGULATIONS UNDER..., represented by the Maritime Administrator, Department of Transportation (“Maritime Administrator”), and ___, a... described in Schedule B hereof; 4. The Maritime Administrator and the Party desire to enter into...

  12. The World War II Homefront: An ERIC/ChESS Sample.

    ERIC Educational Resources Information Center

    Pinhey, Laura

    2002-01-01

    Provides citations with abstracts from the ERIC database focusing on the U.S. homefront during World War II. Includes background information and teaching materials on topics such as popular music from 1941-1945, propaganda directed towards women, and learning about Japanese American internment. (CMK)

  13. An Integrated Microfabricated Device for Dual Microdialysis and On-line ESI Ion Trap Mass Spectrometry for the Analysis of Complex Biological Samples

    SciTech Connect

    Xiang, Fan; Lin, Yuehe ); Wen, Jian Y.; Matson, Dean W. ); Smith, Richard D. )

    1999-05-01

    A microfabricated dual-microdialysis device in a single integrated microfabricated platform was constructed using laser micromachining techniques for the rapid fractionation and cleanup of complex biological samples. Results suggest the potential for integration of such microfabricated devices with other sample manipulations for the rapid ESI-MS analysis of complex biological samples.

  14. Automatic instrument for chemical processing to detect microorganism in biological samples by measuring light reactions

    NASA Technical Reports Server (NTRS)

    Kelbaugh, B. N.; Picciolo, G. L.; Chappelle, E. W.; Colburn, M. E. (Inventor)

    1973-01-01

    An automated apparatus is reported for sequentially assaying urine samples for the presence of bacterial adenosine triphosphate (ATP) that comprises a rotary table which carries a plurality of sample containing vials and automatically dispenses fluid reagents into the vials preparatory to injecting a light producing luciferase-luciferin mixture into the samples. The device automatically measures the light produced in each urine sample by a bioluminescence reaction of the free bacterial adenosine triphosphate with the luciferase-luciferin mixture. The light measured is proportional to the concentration of bacterial adenosine triphosphate which, in turn, is proportional to the number of bacteria present in the respective urine sample.

  15. Biological variation in a large sample of mouse lemurs from Amboasary, Madagascar: implications for interpreting variation in primate biology and paleobiology.

    PubMed

    Cuozzo, Frank P; Rasoazanabary, Emilienne; Godfrey, Laurie R; Sauther, Michelle L; Youssouf, Ibrahim Antho; LaFleur, Marni M

    2013-01-01

    A thorough knowledge of biological variation in extant primates is imperative for interpreting variation, and for delineating species in primate biology and paleobiology. This is especially the case given the recent, rapid taxonomic expansion in many primate groups, notably among small-bodied nocturnal forms. Here we present data on dental, cranial, and pelage variation in a single-locality museum sample of mouse lemurs from Amboasary, Madagascar. To interpret these data, we include comparative information from other museum samples, and from a newly collected mouse lemur skeletal sample from the Beza Mahafaly Special Reserve (BMSR), Madagascar. We scored forty dental traits (n = 126) and three pelage variants (n = 19), and collected 21 cranial/dental measures. Most dental traits exhibit variable frequencies, with some only rarely present. Individual dental variants include misshapen and supernumerary teeth. All Amboasary pelage specimens display a "reversed V" on the cap, and a distinct dorsal median stripe on the back. All but two displayed the dominant gray-brown pelage coloration typical of Microcebus griseorufus. Cranial and dental metric variability are each quite low, and craniometric variation does not illustrate heteroscedasticity. To assess whether this sample represents a single species, we compared dental and pelage variation to a documented, single-species M. griseorufus sample from BMSR. As at Amboasary, BMSR mouse lemurs display limited odontometric variation and wide variation in non-metric dental traits. In contrast, BMSR mouse lemurs display diverse pelage, despite reported genetic homogeneity. Ranges of dental and pelage variation at BMSR and Amboasary overlap. Thus, we conclude that the Amboasary mouse lemurs represent a single species - most likely (in the absence of genetic data to the contrary) M. griseorufus, and we reject their previous allocation to Microcebus murinus. Patterns of variation in the Amboasary sample provide a comparative

  16. Correlation of Arsenic Levels in Smokeless Tobacco Products and Biological Samples of Oral Cancer Patients and Control Consumers.

    PubMed

    Arain, Sadaf S; Kazi, Tasneem G; Afridi, Hassan I; Talpur, Farah N; Kazi, Atif G; Brahman, Kapil D; Naeemullah; Panhwar, Abdul H; Kamboh, Muhammad A

    2015-12-01

    It has been extensively reported that chewing of smokeless tobacco (SLT) can lead to cancers of oral cavity. In present study, the relationship between arsenic (As) exposure via chewing/inhaling different SLT products in oral cancer patients have or/not consumed SLT products was studied. The As in different types of SLT products (gutkha, mainpuri, and snuff) and biological (scalp hair and blood) samples of different types of oral cancer patients and controls were analyzed. Both controls and oral cancer patients have same age group (ranged 30-60 years), socio-economic status, localities, and dietary habits. The concentrations of As in SLT products and biological samples were measured by electrothermal atomic absorption spectrophotometer after microwave-assisted acid digestion. The validity and accuracy of the methodology were checked by certified reference materials. The resulted data of present study indicates that the concentration of As was significantly higher in scalp hair and blood samples of oral cancer patients than those of controls (p<0.001). It was also observed that the values of As were two- to threefolds higher in biological samples of controls subjects, consuming SLT products as compared to those have none of these habits (p>0.01). The intake of As via consuming different SLT may have synergistic effects, in addition to other risk factors associated with oral cancer.

  17. Comparison between Monte Carlo simulation and measurement with a 3D polymer gel dosimeter for dose distributions in biological samples.

    PubMed

    Furuta, T; Maeyama, T; Ishikawa, K L; Fukunishi, N; Fukasaku, K; Takagi, S; Noda, S; Himeno, R; Hayashi, S

    2015-08-21

    In this research, we used a 135 MeV/nucleon carbon-ion beam to irradiate a biological sample composed of fresh chicken meat and bones, which was placed in front of a PAGAT gel dosimeter, and compared the measured and simulated transverse-relaxation-rate (R2) distributions in the gel dosimeter. We experimentally measured the three-dimensional R2 distribution, which records the dose induced by particles penetrating the sample, by using magnetic resonance imaging. The obtained R2 distribution reflected the heterogeneity of the biological sample. We also conducted Monte Carlo simulations using the PHITS code by reconstructing the elemental composition of the biological sample from its computed tomography images while taking into account the dependence of the gel response on the linear energy transfer. The simulation reproduced the experimental distal edge structure of the R2 distribution with an accuracy under about 2 mm, which is approximately the same as the voxel size currently used in treatment planning. PMID:26266894

  18. Correlation of Arsenic Levels in Smokeless Tobacco Products and Biological Samples of Oral Cancer Patients and Control Consumers.

    PubMed

    Arain, Sadaf S; Kazi, Tasneem G; Afridi, Hassan I; Talpur, Farah N; Kazi, Atif G; Brahman, Kapil D; Naeemullah; Panhwar, Abdul H; Kamboh, Muhammad A

    2015-12-01

    It has been extensively reported that chewing of smokeless tobacco (SLT) can lead to cancers of oral cavity. In present study, the relationship between arsenic (As) exposure via chewing/inhaling different SLT products in oral cancer patients have or/not consumed SLT products was studied. The As in different types of SLT products (gutkha, mainpuri, and snuff) and biological (scalp hair and blood) samples of different types of oral cancer patients and controls were analyzed. Both controls and oral cancer patients have same age group (ranged 30-60 years), socio-economic status, localities, and dietary habits. The concentrations of As in SLT products and biological samples were measured by electrothermal atomic absorption spectrophotometer after microwave-assisted acid digestion. The validity and accuracy of the methodology were checked by certified reference materials. The resulted data of present study indicates that the concentration of As was significantly higher in scalp hair and blood samples of oral cancer patients than those of controls (p<0.001). It was also observed that the values of As were two- to threefolds higher in biological samples of controls subjects, consuming SLT products as compared to those have none of these habits (p>0.01). The intake of As via consuming different SLT may have synergistic effects, in addition to other risk factors associated with oral cancer. PMID:25975948

  19. A direct solid sampling electrothermal atomic absorption spectrometry method for the determination of silicon in biological materials

    NASA Astrophysics Data System (ADS)

    Huang, M. D.; Krivan, V.

    2007-03-01

    A solid sampling electrothermal atomic absorption spectrometry method for direct determination of trace silicon in biological materials was developed and applied to analysis of pork liver, bovine liver SRM 1577b and pure cellulose. The organic matrix was destroyed and expelled from the furnace in the pyrolysis stage involving a step-wise increasing the temperature from 160 °C to 1200 °C. The mixed Pd/Mg(NO 3) 2 modifier has proved to be the optimum one with respect to the achievement of maximum sensitivity, elimination of the effect of the remaining inorganic substances and the possibility of using calibration curves measured with aqueous standard solutions for quantification. For the maximum applicable sample amount of 6 mg, the limit of detection was found to be 30 ng g - 1 . The results were compared with those obtained by different spectrometric methods involving sample digestion, by electrothermal atomic absorption spectrometry using slurry sampling, by wavelength dispersive X-ray fluorescence spectrometry and by radiochemical neutron activation analysis. The method seems to be a promising one for analysis of biological materials containing no significant fraction of silicon in form of not naturally occurring volatile organosilicon compounds. The still incessant serious limitations and uncertainties in the determination of trace silicon in solid biological materials are discussed.

  20. Comparison between Monte Carlo simulation and measurement with a 3D polymer gel dosimeter for dose distributions in biological samples

    NASA Astrophysics Data System (ADS)

    Furuta, T.; Maeyama, T.; Ishikawa, K. L.; Fukunishi, N.; Fukasaku, K.; Takagi, S.; Noda, S.; Himeno, R.; Hayashi, S.

    2015-08-01

    In this research, we used a 135 MeV/nucleon carbon-ion beam to irradiate a biological sample composed of fresh chicken meat and bones, which was placed in front of a PAGAT gel dosimeter, and compared the measured and simulated transverse-relaxation-rate (R2) distributions in the gel dosimeter. We experimentally measured the three-dimensional R2 distribution, which records the dose induced by particles penetrating the sample, by using magnetic resonance imaging. The obtained R2 distribution reflected the heterogeneity of the biological sample. We also conducted Monte Carlo simulations using the PHITS code by reconstructing the elemental composition of the biological sample from its computed tomography images while taking into account the dependence of the gel response on the linear energy transfer. The simulation reproduced the experimental distal edge structure of the R2 distribution with an accuracy under about 2 mm, which is approximately the same as the voxel size currently used in treatment planning.

  1. Determination of cobalt in biological samples by line-source and high-resolution continuum source graphite furnace atomic absorption spectrometry using solid sampling or alkaline treatment

    NASA Astrophysics Data System (ADS)

    Ribeiro, Anderson Schwingel; Vieira, Mariana Antunes; da Silva, Alessandra Furtado; Borges, Daniel L. Gallindo; Welz, Bernhard; Heitmann, Uwe; Curtius, Adilson José

    2005-06-01

    Two procedures for the determination of Co in biological samples by graphite furnace atomic absorption spectrometry (GF AAS) were compared: solid sampling (SS) and alkaline treatment with tetramethylammonium hydroxide (TMAH) using two different instruments for the investigation: a conventional line-source (LS) atomic absorption spectrometer and a prototype high-resolution continuum source atomic absorption spectrometer. For the direct introduction of the solid samples, certified reference materials (CRM) were ground to a particle size ≤50 μm. Alkaline treatment was carried out by placing about 250 mg of the sample in polypropylene flasks, adding 2 mL of 25% m/v tetramethylammonium hydroxide and de-ionized water. Due to its unique capacity of providing a 3-D spectral plot, a high-resolution continuum source (HR-CS) graphite furnace atomic absorption spectrometry was used as a tool to evaluate potential spectral interferences, including background absorption for both sample introduction procedures, revealing that a continuous background preceded the atomic signal for pyrolysis temperatures lower than 700 °C. Molecular absorption bands with pronounced rotational fine structure appeared for atomization temperatures >1800 °C probably as a consequence of the formation of PO. After optimization had been carried out using high resolution continuum source atomic absorption spectrometry, the optimized conditions were adopted also for line-source atomic absorption spectrometry. Six biological certified reference materials were analyzed, with calibration against aqueous standards, resulting in agreement with the certified values (according to the t-test for a 95% confidence level) and in detection limits as low as 5 ng g -1.

  2. Combining partially ranked data in plant breeding and biology: II. Analysis with Rasch model.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many years of breeding experiments, germplasm screening, and molecular biologic experimentation have generated volumes of sequence, genotype, and phenotype information that have been stored in public data repositories. These resources afford genetic and genomic researchers the opportunity to handle ...

  3. A New Chelating Reagent: Its Synthesis/Characterization and Application for the Determination of Cd(II) and Ni(II) in Various Food and Make-Up Product Samples by FAAS Using Simultaneous Microextraction Sampling.

    PubMed

    Saçmacı, Şerife; Saçmacı, Mustafa

    2016-07-01

    A new and simple dispersive liquid-liquid simultaneous microextraction procedure was developed for the rapid separation and simultaneous extraction/preconcentration of Cd(II) and Ni(II) at ultratrace amounts. Microextraction of the analytes was carried out in the presence of 2-methyl-5-[(Z)-pyridin-4-yldiazenyl]quinolin-8-ol as the chelating reagent. Chloroform and ethanol were used as the extraction and dispersive solvents. Various parameters that influence the microextraction procedure's efficiency-such as pH, centrifugation rate and time, reagent concentration, and sampling volume on the recovery of analytes-were examined. The calibration curves were linear in the range of 0.01-1.25 and 0.075-5 mg/L with LODs of 0.25 and 0.84 μg/L, and with a preconcentration factor of 94, for Cd(II) and Ni(II), respectively. Precision was >1.0%. The accuracy of the method was confirmed by analyzing the Certified Standard Reference Material (CWW-TMD: Certified wastewater-Trace metals, wastewater). The results show that the dispersive liquid-liquid simultaneous microextraction pretreatment is a sensitive, rapid, simple, green, and safe method for the separation/preconcentration of cadmium and nickel. PMID:27301349

  4. Direct determination and speciation of mercury compounds in environmental and biological samples by carbon bed atomic absorption spectroscopy

    SciTech Connect

    Skelly, E.M.

    1982-01-01

    A method was developed for the direct determination of mercury in water and biological samples using a unique carbon bed atomizer for atomic absorption spectroscopy. The method avoided sources of error such as loss of volatile mercury during sample digestion and contamination of samples through added reagents by eliminating sample pretreatment steps. The design of the atomizer allowed use of the 184.9 nm mercury resonance line in the vacuum ultraviolet region, which increased sensitivity over the commonly used spin-forbidden 253.7 nm line. The carbon bed atomizer method was applied to a study of mercury concentrations in water, hair, sweat, urine, blood, breath and saliva samples from a non-occupationally exposed population. Data were collected on the average concentration, the range and distribution of mercury in the samples. Data were also collected illustrating individual variations in mercury concentrations with time. Concentrations of mercury found were significantly higher than values reported in the literature for a ''normal'' population. This is attributed to the increased accuracy gained by eliminating pretreatment steps and increasing atomization efficiency. Absorption traces were obtained for various solutions of pure and complexed mercury compounds. Absorption traces of biological fluids were also obtained. Differences were observed in the absorption-temperatures traces of various compounds. The utility of this technique for studying complexation was demonstrated.

  5. Design of sample carrier for neutron irradiation facility at TRIGA MARK II nuclear reactor

    NASA Astrophysics Data System (ADS)

    Abdullah, Y.; Hamid, N. A.; Mansor, M. A.; Ahmad, M. H. A. R. M.; Yusof, M. R.; Yazid, H.; Mohamed, A. A.

    2013-06-01

    The objective of this work is to design a sample carrier for neutron irradiation experiment at beam ports of research nuclear reactor, the Reaktor TRIGA PUSPATI (RTP). The sample carrier was designed so that irradiation experiment can be performed safely by researchers. This development will resolve the transferring of sample issues faced by the researchers at the facility when performing neutron irradiation studies. The function of sample carrier is to ensure the sample for the irradiation process can be transferred into and out from the beam port of the reactor safely and effectively. The design model used was House of Quality Method (HOQ) which is usually used for developing specifications for product and develop numerical target to work towards and determining how well we can meet up to the needs. The chosen sample carrier (product) consists of cylindrical casing shape with hydraulic cylinders transportation method. The sample placing can be done manually, locomotion was by wheel while shielding used was made of boron materials. The sample carrier design can shield thermal neutron during irradiation of sample so that only low fluencies fast neutron irradiates the sample.

  6. Stable isotope imaging of biological samples with high resolution secondary ion mass spectrometry and complementary techniques

    PubMed Central

    Jiang, H.; Favaro, E.; Goulbourne, C. N.; Rakowska, P. D.; Hughes, G. M.; Ryadnov, M. G.; Fong, L.G.; Young, S. G.; Ferguson, D. J. P.; Harris, A. L.; Grovenor, C. R. M.

    2014-01-01

    Stable isotopes are ideal labels for studying biological processes because they have little or no effect on the biochemical properties of target molecules. The NanoSIMS is a tool that can image the distribution of stable isotope labels with up to 50 nm spatial resolution and with good quantitation. This combination of features has enabled several groups to undertake significant experiments on biological problems in the last decade. Combining the NanoSIMS with other imaging techniques also enables us to obtain not only chemical information but also the structural information needed to understand biological processes. This article describes the methodologies that we have developed to correlate atomic force microscopy and backscattered electron imaging with NanoSIMS experiments to illustrate the imaging of stable isotopes at molecular, cellular, and tissue scales. Our studies make it possible to address 3 biological problems: (1) the interaction of antimicrobial peptides with membranes; (2) glutamine metabolism in cancer cells; and (3) lipoprotein interactions in different tissues. PMID:24556558

  7. neutron activation analysis using thermochromatography. III. analysis of samples of biological origin

    SciTech Connect

    Sattarov, G.; Davydov, A.V.; Khamatov, S.; Kist, A.A.

    1986-07-01

    The use of gas thermochromatography (GTC) in the radioactivation analysis of biological materials is discussed. A group separation of a number of highly volatile elements from sodium and bromine radionuclides has been achieved. The limit of detection of the elements by INAA and neutron activation analysis was estimated using GTC. The advantages of the procedure and the analytical parameters are discussed.

  8. Perceived Use of Inquiry Teaching by a Sample of Malaysian Biology Teachers.

    ERIC Educational Resources Information Center

    Ismail, Nor Asma; Rubba, Peter A.

    1981-01-01

    Determined degree to which Malaysian biology teachers (N=26) perceived they understood and used inquiry teaching. Data indicated that these teachers perceived they had a moderate amount of knowledge about inquiry and occasionally used the 21 inquiry-related behaviors assessed by "A Generic Problem Solving (Inquiry) Model" (Hungerford, 1975).…

  9. Application of a complex constraint for biological samples in coherent diffractive imaging.

    PubMed

    Jones, M W M; Peele, A G; van Riessen, G A

    2013-12-16

    We demonstrate the application of a complex constraint in the reconstruction of images from phase-diverse Fresnel coherent diffraction data for heterogeneous biological objects. The application of this constraint is shown to improve the quality of the reconstruction of both the phase and the magnitude of the complex object transmission function. PMID:24514606

  10. Determination of the Biologically Relevant Sampling Depth for Terrestrial and Aquatic Ecological Risk Assessments (Final Report)

    EPA Science Inventory

    This technical paper provides defensible approximations for what the depth of the biologically active zone, or “biotic zone” is within certain environments. The methods used in this study differ somewhat between Part 1 (Terrestrial Biotic Zone) and Part 2 (Aquatic Biotic Zone). ...

  11. Preparation of Plant Samples for Phytochemical Research and the Study of Their Biological Activities

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Prior to investigating plant natural products for biologically active constituents, it is necessary to establish guidelines and procedures for carefully collecting, cataloging, and storing specimens. All field collections should begin with detailed records on location, which should include a list o...

  12. How Parents Influence School Grades: Hints from a Sample of Adoptive and Biological Families

    ERIC Educational Resources Information Center

    Johnson, Wendy; McGue, Matt; Iacono, William G.

    2007-01-01

    Using the biological and adoptive families in the Minnesota-based Sibling Interaction and Behavior Study, we investigated the associations among genetic and environmental influences on IQ, parenting, parental expectations for offspring educational attainment, engagement in school, and school grades. All variables showed substantial genetic…

  13. Automated sample mounting and technical advance alignment system for biological crystallography at a synchrotron source

    SciTech Connect

    Snell, Gyorgy; Cork, Carl; Nordmeyer, Robert; Cornell, Earl; Meigs, George; Yegian, Derek; Jaklevic, Joseph; Jin, Jian; Stevens, Raymond C.; Earnest, Thomas

    2004-01-07

    High-throughput data collection for macromolecular crystallography requires an automated sample mounting system for cryo-protected crystals that functions reliably when integrated into protein-crystallography beamlines at synchrotrons. Rapid mounting and dismounting of the samples increases the efficiency of the crystal screening and data collection processes, where many crystals can be tested for the quality of diffraction. The sample-mounting subsystem has random access to 112 samples, stored under liquid nitrogen. Results of extensive tests regarding the performance and reliability of the system are presented. To further increase throughput, we have also developed a sample transport/storage system based on ''puck-shaped'' cassettes, which can hold sixteen samples each. Seven cassettes fit into a standard dry shipping Dewar. The capabilities of a robotic crystal mounting and alignment system with instrumentation control software and a relational database allows for automated screening and data collection to be developed.

  14. Spectroscopic and biological studies on newly synthesized nickel(II) complexes of semicarbazones and thiosemicarbazones

    NASA Astrophysics Data System (ADS)

    Chandra, Sulekh; Gupta, Lokesh Kumar

    2005-12-01

    Nickel(II) complexes, having the general composition Ni(L) 2X 2, have been synthesized [where L: isopropyl methyl ketone semicarbazone (LLA), isopropyl methyl ketone thiosemicarbazone (LLB), 4-aminoacetophenone semicarbazone (LLC) and 4-aminoacetophenone thiosemicarbazone (LLD) and X = Cl -, 1/2SO 42-]. All the Ni(II) complexes reported here have been characterized by elemental analyses, magnetic moments, IR, electronic and mass spectral studies. All the complexes were found to have magnetic moments corresponding to two unpaired electrons. The possible geometries of the complexes were assigned on the basis of electronic and infrared spectral studies. Newly synthesized ligand and its nickel(II) complexes have been screened against different bacterial and fungal growth.

  15. Simple method to measure power density entering a plane biological sample at millimeter wavelengths.

    PubMed

    Shen, Z Y; Birenbaum, L; Chu, A; Motzkin, S; Rosenthal, S; Sheng, K M

    1987-01-01

    A simple method for measuring microwave power density is described. It is applicable to situations where exposure of samples in the near field of a horn is necessary. A transmitted power method is used to calibrate the power density entering the surface of the sample. Once the calibration is available, the power density is known in terms of the incident and reflected powers within the waveguide. The calibration has been carried out for liquid samples in a quartz cell. Formulas for calculating specific absorption rate (SAR) are derived in terms of the power density and the complex dielectric constant of the sample. An error analysis is also given.

  16. Determination of total iodine in nutritional and biological samples by ICP-MS following their combustion within an oxygen stream.

    PubMed

    Gélinas, Y; Krushevska, A; Barnes, R M

    1998-03-01

    A mineralization and determination method for total iodine in nutritional and biological samples is described. Combustion of the sample in an oxygen stream is followed by collection of the combustion products in a 5% water-soluble tertiary amine solution. Iodine is determined by inductively coupled plasma mass spectrometry. The accuracy and precision of the quantitative iodine analysis using standard addition is better than +/- 10%. A semi-quantitative analysis of four standard reference materials is evaluated. Owing to the presence of low-level iodine contaminant in the blank solution, the determination limit of the method is +/- 10 micrograms kg-1. Good agreement with certified iodine values is obtained for six reference materials. The use of the tertiary amine matrix solution permits the simultaneous determination of iodine and other trace metals of biological and toxicological importance, including Mn, Co, Ni, Cu, Zn, Rb, Cd, and Pb.

  17. Sample Preparation Techniques for the Untargeted LC-MS-Based Discovery of Peptides in Complex Biological Matrices

    PubMed Central

    Finoulst, Inez; Pinkse, Martijn; Van Dongen, William; Verhaert, Peter

    2011-01-01

    Although big progress has been made in sample pretreatment over the last years, there are still considerable limitations when it comes to overcoming complexity and dynamic range problems associated with peptide analyses from biological matrices. Being the little brother of proteomics, peptidomics is a relatively new field of research aiming at the direct analysis of the small proteins, called peptides, many of which are not amenable for typical trypsin-based analytics. In this paper, we present an overview of different techniques and methods currently used for reducing a sample's complexity and for concentrating low abundant compounds to enable successful peptidome analysis. We focus on techniques which can be employed prior to liquid chromatography coupled to mass spectrometry for peptide detection and identification and indicate their advantages as well as their shortcomings when it comes to the untargeted analysis of native peptides from complex biological matrices. PMID:22203783

  18. A 96-well screen filter plate for high-throughput biological sample preparation and LC-MS/MS analysis.

    PubMed

    Peng, Sean X; Cousineau, Martin; Juzwin, Stephen J; Ritchie, David M

    2006-01-01

    A novel 96-well screen filter plate (patent pending) has been invented to eliminate a time-consuming and labor-intensive step in preparation of in vivo study samples--to remove blood or plasma clots. These clots plug the pipet tips during a manual or automated sample-transfer step causing inaccurate pipetting or total pipetting failure. Traditionally, these blood and plasma clots are removed by picking them out manually one by one from each sample tube before any sample transfer can be made. This has significantly slowed the sample preparation process and has become a bottleneck for automated high-throughput sample preparation using robotic liquid handlers. Our novel screen filter plate was developed to solve this problem. The 96-well screen filter plate consists of 96 stainless steel wire-mesh screen tubes connected to the 96 openings of a top plate so that the screen filter plate can be readily inserted into a 96-well sample storage plate. Upon insertion, the blood and plasma clots are excluded from entering the screen tube while clear sample solutions flow freely into it. In this way, sample transfer can be easily completed by either manual or automated pipetting methods. In this report, three structurally diverse compounds were selected to evaluate and validate the use of the screen filter plate. The plasma samples of these compounds were transferred and processed in the presence and absence of the screen filter plate and then analyzed by LC-MS/MS methods. Our results showed a good agreement between the samples prepared with and without the screen filter plate, demonstrating the utility and efficiency of this novel device for preparation of blood and plasma samples. The device is simple, easy to use, and reusable. It can be employed for sample preparation of other biological fluids that contain floating particulates or aggregates. PMID:16383347

  19. Gelatin embedding: a novel way to preserve biological samples for terahertz imaging and spectroscopy

    NASA Astrophysics Data System (ADS)

    Fan, Shuting; Ung, Benjamin; Parrott, Edward P. J.; Pickwell-MacPherson, Emma

    2015-04-01

    Sample dehydration has traditionally been a challenging problem in ex vivo terahertz biomedical experiments as water content changes significantly affect the terahertz properties and can diminish important contrast features. In this paper, we propose a novel method to prevent sample dehydration using gelatin embedding. By looking at terahertz image data and calculating the optical properties of the gelatin-embedded sample, we find that our method successfully preserves the sample for at least 35 h, both for imaging and spectroscopy. Our novel preservation method demonstrates for the first time the capability to simultaneously maintain sample structural integrity and prevent dehydration at room temperature. This is particularly relevant for terahertz studies of freshly excised tissues but could be beneficial for other imaging and spectroscopy techniques.

  20. A sensitive method for the determination of uranium in biological samples utilizing kinetic phosphorescence analysis (KPA).

    PubMed

    Hedaya, M A; Birkenfeld, H P; Kathren, R L

    1997-05-01

    Kinetic phosphorescence analysis is a technique that provides rapid, precise and accurate determination of uranium concentration in aqueous solutions. This technique utilizes a laser source to excite an aqueous solution of uranium, and measures the emission luminescence intensity over time to determine the luminescence decay profile. The lifetime of the luminescence decay profile and the linearity of the log luminescence intensity versus time profile are indications of the specificity of the technique for uranium determination. The luminescence intensity at the onset of decay (the initial luminescence intensity), which is the luminescence intensity at time zero after termination of the laser pulse used for excitation, is proportional to the uranium concentration in the sample. Calibration standards of known uranium concentrations are used to construct the calibration curve between the initial luminescence intensity and uranium concentration. This calibration curve is used to determine the uranium concentration of unknown samples from their initial luminescence intensity. We developed the sample preparation method that allows the determination of uranium concentrations in urine, plasma, kidney, liver, bone spleen and soft tissue samples. Tissue samples are subjected to dry-ashing in a muffle furnace at 600 degrees C and wet-ashing with concentrated nitric acid and hydrogen peroxide twice to destroy the organic component in the sample that may interfere with uranium determination by KPA. Samples are then solubilized in 0.82 M nitric acid prior to analysis by KPA. The assay calibration curves are linear and cover the range of uranium concentrations between 0.05 micrograms l-1 and 1000 micrograms l-1 (0.05-1000 ppb). The developed sample preparation procedures coupled with the KPA technique provide a specific, sensitive, precise and accurate method for the determination of uranium concentration in tissue samples. This method was used to quantify uranium in different

  1. Synthesis, characterization and biological activity of phthalimide derivatives of Cu(II) complex

    NASA Astrophysics Data System (ADS)

    Lingappa, Y.; Rao, S. Sreenivasa; Ravikumar, R. V. S. S. N.; Rao, P. Sambasiva

    The Cu(II) complex of phthalimide-o-aminophenylenediamine has been synthesized by a template method. The complex is characterized by elemental analysis, conductivity measurements and electronic and EPR spectral techniques. The electronic spectra reveal four coordinations for the Cu(II) ion with the ligand. The evaluated spin-Hamiltonian parameters from the EPR spectrum are g|D2.2041, g⊥D2.0263 and A|D166×10-4 cm-1 and A⊥D46×10-4 cm-1E By correlating EPR and electronic data, the calculated bonding parameters are α2D0.7132, αD0.8445, α'D0.6073 and ?. These bonding parameters suggest a moderate covalent nature of the Cu(II) ion with the ligand. Antimicrobial activities of this Cu(II) complex against six bacterial isolates like Bacillus faecalis, Escherichia coil, Pseudomonas aeruginosa, Salmonella typhimurium and Klebsiella pneumoniae are determined.

  2. Evaluation of cadmium, lead, nickel and zinc status in biological samples of smokers and nonsmokers hypertensive patients

    PubMed Central

    Afridi, H I; Kazi, T G; Kazi, N G; Jamali, M K; Arain, M B; Sirajuddin; Baig, J A; Kandhro, G A; Wadhwa, S K; Shah, A Q

    2010-01-01

    The objective of this study was to evaluate the association between trace and toxic elements zinc (Zn), cadmium (Cd), nickel (Ni) and lead (Pb) in biological samples (scalp hair, blood and urine) of smoker and nonsmoker hypertensive patients (n=457), residents of Hyderabad, Pakistan. For the purpose of comparison, the biological samples of age-matched healthy controls were selected as referents. The concentrations of trace and toxic elements were measured by atomic absorption spectrophotometer prior to microwave-assisted acid digestion. The validity and accuracy of the methodology were checked using certified reference materials and by the conventional wet acid digestion method on the same certified reference materials and real samples. The recovery of all the studied elements was found to be in the range of 97.8–99.3% in certified reference materials. The results of this study showed that the mean values of Cd, Ni and Pb were significantly higher in scalp hair, blood and urine samples of both smoker and nonsmoker patients than in referents (P<0.001), whereas the concentration of Zn was lower in the scalp hair and blood, but higher in the urine samples of hypertensive patients. The deficiency of Zn and the high exposure of toxic metals as a result of tobacco smoking may be synergistic with risk factors associated with hypertension. PMID:20010608

  3. Utility of cefixime as a complexing reagent for the determination of Ni(II) in synthetic mixture and water samples.

    PubMed

    Azmi, Syed Najmul Hejaz; Iqbal, Bashir; Al Khanbashi, Reem Saif; Al Hamhami, Nadia Humaid; Rahman, Nafisur

    2013-06-01

    A simple, sensitive, and accurate UV spectrophotometric method has been developed for the determination of nickel in synthetic mixture and water samples. The method is based on the complexation reaction of nickel ion with cefixime, thus leading to the formation of Ni-cefixime complex in ethanol-distilled water medium at room temperature. The complex showed the maximum absorption wavelength at 332 nm. Beer's law is obeyed in the working concentration range of 0.447-4.019 μg mL(-1) with apparent molar absorptivity of 7.314 × 10(3) L mol(-1) cm(-1) and Sandell's sensitivity of 0.008 μg/cm(2)/0.001 absorbance unit. The limits of detection and quantitation for the proposed method are 0.016 and 0.054 μg mL(-1), respectively. The factors such as cefixime concentration and solvent affecting the complexation reaction were carefully studied and optimized. The method is validated as per the International Conference on Harmonisation guideline. The method is successfully applied to the determination of Ni(II) in synthetic mixture and wadi water samples collected from Al Rustaq. The same water samples are also analyzed by atomic absorption spectrophotometry. Both methods determined the amount of Ni(II) in water sample and found to be approximately the same.

  4. PROPERTIES OF M31. II. A CEPHEID DISK SAMPLE DERIVED FROM THE FIRST YEAR OF PS1 PANDROMEDA DATA

    SciTech Connect

    Kodric, Mihael; Riffeser, Arno; Hopp, Ulrich; Seitz, Stella; Koppenhoefer, Johannes; Bender, Ralf; Goessl, Claus; Snigula, Jan; Lee, Chien-Hsiu; Ngeow, Chow-Choong; Chambers, K. C.; Magnier, E. A.; Price, P. A.; Burgett, W. S.; Hodapp, K. W.; Kaiser, N.; Kudritzki, R.-P.

    2013-04-15

    We present a sample of Cepheid variable stars toward M31 based on the first year of regular M31 observations of the PS1 survey in the r{sub P1} and i{sub P1} filters. We describe the selection procedure for Cepheid variable stars from the overall variable source sample and develop an automatic classification scheme using Fourier decomposition and the location of the instability strip. We find 1440 fundamental mode (classical {delta}) Cep stars, 126 Cepheids in the first overtone mode, and 147 belonging to the Population II types. Two hundred ninety-six Cepheids could not be assigned to one of these classes and three hundred fifty-four Cepheids were found in other surveys. These 2009 Cepheids constitute the largest Cepheid sample in M31 known so far and the full catalog is presented in this paper. We briefly describe the properties of our sample in its spatial distribution throughout the M31 galaxy, in its age properties, and we derive an apparent period-luminosity relation (PLR) in our two bands. The Population I Cepheids nicely follow the dust pattern of the M31 disk, whereas the 147 Type II Cepheids are distributed throughout the halo of M31. We outline the time evolution of the star formation in the major ring found previously and find an age gradient. A comparison of our PLR to previous results indicates a curvature term in the PLR.

  5. A high-performance direct transmethylation method for total fatty acids assessment in biological and foodstuff samples.

    PubMed

    Castro-Gómez, Pilar; Fontecha, Javier; Rodríguez-Alcalá, Luis M

    2014-10-01

    Isolation is the main bottleneck in the analysis of fatty acids in biological samples and foods. In the last few decades some methods described direct derivatization procedures bypassing these steps. They involve the utilization of methanolic HCL or BF3 as catalysts, but several evidences from previous works suggest these reagents are unstable, lead to the formation of artifacts and alter the distribution of specific compounds as hydroxy fatty acids or CLA. However, the main issue is that they are excellent esterification reagents but poor in transterification, being not suitable for the analysis of all lipid classes and leading to erroneous composition quantitations. The present research work is a comprehensive comparison of six general methylation protocols using base, acid or base/acid catalysts plus a proposed method in the analysis of total fatty acids in lipid standards mixtures, foodstuff and biological samples. The addition of aprotic solvents to the reaction mixture to avoid alterations was also tested. Results confirmed that procedures solely involving acid catalyst resulted in incomplete derivatizations and alteration of the fatty acid profile, partially corrected by addition of the aprotic solvent. The proposed method combining sodium methoxyde and sulfuric acid showed absence of alteration of the FAME profile and the best values for response factors (short chain fatty acids to PUFA), accuracy in the determination of total cholesterol and derivatization performance, thus showing a high reliability in the determination of the total fatty acid composition in biological samples and foods.

  6. Data mining and biological sample exportation from South Africa: A new wave of bioexploitation under the guise of clinical care?

    PubMed

    Staunton, Ciara; Moodley, Keymanthri

    2016-02-01

    Discovery Health, one of the leading healthcare funders in South Africa (SA), will offer genetic testing to its members for USD250 (approximately ZAR3 400) per test from 2016. On the surface, this appears to be innovative and futuristic. However, a deeper look at this announcement reveals considerable problems in the exportation of biological samples and data out of SA, and brings into sharp focus the lack of protection in place for potential donors. In return for a reduced-cost genetic test, which will nevertheless be billed to a member's savings plan, data from the patient's results, and probably the sample itself, will be sent to the USA for storage, research purposes and possible commercial use, with no further benefit for the patient. This development has demonstrated the need for more stringent protection of the movement of biological samples and data out of SA, particularly with reference to consenting procedures, material transfer agreements, and the export of biological data themselves. PMID:26821890

  7. Recent on-line processing procedures for biological samples for determination of trace elements by atomic spectrometric methods

    NASA Astrophysics Data System (ADS)

    Burguera, José L.; Burguera, Marcela

    2009-06-01

    Few of the elements present in nature play a metabolic role in living organisms. According to their abundance, these elements are classified as macro-, micro- or trace elements, representing 93%, 5% and around 1% respectively, of the total body weight. The remaining percentage could be attributed to those elements with unknown biological functions, to others which are present only because of the exposure to polluted environment or to those intentionally introduced into the body for a special treatment. This review summarizes and discusses the most recent publications related to the on-line processing of biological samples for trace element determination using atomic spectrometry-based detectors. Preconcentration/separation procedures based on solid phase or cloud point extractions, electrochemical deposition, microdialysis, as well as chemical vapor generation are the common practice for improving the sensitivity and selectivity of the available atomic spectrometric techniques. The advantages of using isotope dilution mass spectrometry in speciation studies are also emphasized. Digestion or leaching in oxidizing acidic mixtures aided by heat or by ultrasound or microwave radiation, performed off- or on-line, is necessary to previous steps when processing solid biological samples. The most relevant analytical figures of merit such as detection limits, enrichment factors and sample throughput as well as some aspects related to the on-line system configurations and accuracy assessments are critically presented.

  8. Capillary zone electrophoresis for analysis of phytochelatins and other thiol peptides in complex biological samples derivatized with monobromobimane.

    PubMed

    Perez-Rama, Mónica; Torres Vaamonde, Enrique; Abalde Alonso, Julio

    2005-02-01

    A new method to improve the analysis of phytochelatins and their precursors (cysteine, gamma-Glu-Cys, and glutathione) derivatized with monobromobimane (mBrB) in complex biological samples by capillary zone electrophoresis is described. The effects of the background electrolyte pH, concentration, and different organic additives (acetonitrile, methanol, and trifluoroethanol) on the separation were studied to achieve optimum resolution and number of theoretical plates of the analyzed compounds in the electropherograms. Optimum separation of the thiol peptides was obtained with 150 mM phosphate buffer at pH 1.60. Separation efficiency was improved when 2.5% v/v methanol was added to the background electrolyte. The electrophoretic conditions were 13 kV and capillary dimensions with 30 cm length from the inlet to the detector (38 cm total length) and 50 microm inner diameter. The injection was by pressure at 50 mbar for 17 s. Under these conditions, the separation between desglycyl-peptides and phytochelatins was also achieved. We also describe the optimum conditions for the derivatization of biological samples with mBrB to increase electrophoretic sensitivity and number of theoretical plates. The improved method was shown to be simple, reproducible, selective, and accurate in measuring thiol peptides in complex biological samples, the detection limit being 2.5 microM glutathione at a wavelength of 390 nm.

  9. A high-performance direct transmethylation method for total fatty acids assessment in biological and foodstuff samples.

    PubMed

    Castro-Gómez, Pilar; Fontecha, Javier; Rodríguez-Alcalá, Luis M

    2014-10-01

    Isolation is the main bottleneck in the analysis of fatty acids in biological samples and foods. In the last few decades some methods described direct derivatization procedures bypassing these steps. They involve the utilization of methanolic HCL or BF3 as catalysts, but several evidences from previous works suggest these reagents are unstable, lead to the formation of artifacts and alter the distribution of specific compounds as hydroxy fatty acids or CLA. However, the main issue is that they are excellent esterification reagents but poor in transterification, being not suitable for the analysis of all lipid classes and leading to erroneous composition quantitations. The present research work is a comprehensive comparison of six general methylation protocols using base, acid or base/acid catalysts plus a proposed method in the analysis of total fatty acids in lipid standards mixtures, foodstuff and biological samples. The addition of aprotic solvents to the reaction mixture to avoid alterations was also tested. Results confirmed that procedures solely involving acid catalyst resulted in incomplete derivatizations and alteration of the fatty acid profile, partially corrected by addition of the aprotic solvent. The proposed method combining sodium methoxyde and sulfuric acid showed absence of alteration of the FAME profile and the best values for response factors (short chain fatty acids to PUFA), accuracy in the determination of total cholesterol and derivatization performance, thus showing a high reliability in the determination of the total fatty acid composition in biological samples and foods. PMID:25059195

  10. Metabolomics identifies a biological response to chronic low-dose natural uranium contamination in urine samples.

    PubMed

    Grison, Stéphane; Favé, Gaëlle; Maillot, Matthieu; Manens, Line; Delissen, Olivia; Blanchardon, Eric; Banzet, Nathalie; Defoort, Catherine; Bott, Romain; Dublineau, Isabelle; Aigueperse, Jocelyne; Gourmelon, Patrick; Martin, Jean-Charles; Souidi, Maâmar

    2013-01-01

    Because uranium is a natural element present in the earth's crust, the population may be chronically exposed to low doses of it through drinking water. Additionally, the military and civil uses of uranium can also lead to environmental dispersion that can result in high or low doses of acute or chronic exposure. Recent experimental data suggest this might lead to relatively innocuous biological reactions. The aim of this study was to assess the biological changes in rats caused by ingestion of natural uranium in drinking water with a mean daily intake of 2.7 mg/kg for 9 months and to identify potential biomarkers related to such a contamination. Subsequently, we observed no pathology and standard clinical tests were unable to distinguish between treated and untreated animals. Conversely, LC-MS metabolomics identified urine as an appropriate biofluid for discriminating the experimental groups. Of the 1,376 features detected in urine, the most discriminant were metabolites involved in tryptophan, nicotinate, and nicotinamide metabolic pathways. In particular, N-methylnicotinamide, which was found at a level seven times higher in untreated than in contaminated rats, had the greatest discriminating power. These novel results establish a proof of principle for using metabolomics to address chronic low-dose uranium contamination. They open interesting perspectives for understanding the underlying biological mechanisms and designing a diagnostic test of exposure.

  11. Active Learning Not Associated with Student Learning in a Random Sample of College Biology Courses

    PubMed Central

    Andrews, T. M.; Leonard, M. J.; Colgrove, C. A.; Kalinowski, S. T.

    2011-01-01

    Previous research has suggested that adding active learning to traditional college science lectures substantially improves student learning. However, this research predominantly studied courses taught by science education researchers, who are likely to have exceptional teaching expertise. The present study investigated introductory biology courses randomly selected from a list of prominent colleges and universities to include instructors representing a broader population. We examined the relationship between active learning and student learning in the subject area of natural selection. We found no association between student learning gains and the use of active-learning instruction. Although active learning has the potential to substantially improve student learning, this research suggests that active learning, as used by typical college biology instructors, is not associated with greater learning gains. We contend that most instructors lack the rich and nuanced understanding of teaching and learning that science education researchers have developed. Therefore, active learning as designed and implemented by typical college biology instructors may superficially resemble active learning used by education researchers, but lacks the constructivist elements necessary for improving learning. PMID:22135373

  12. Active learning not associated with student learning in a random sample of college biology courses.

    PubMed

    Andrews, T M; Leonard, M J; Colgrove, C A; Kalinowski, S T

    2011-01-01

    Previous research has suggested that adding active learning to traditional college science lectures substantially improves student learning. However, this research predominantly studied courses taught by science education researchers, who are likely to have exceptional teaching expertise. The present study investigated introductory biology courses randomly selected from a list of prominent colleges and universities to include instructors representing a broader population. We examined the relationship between active learning and student learning in the subject area of natural selection. We found no association between student learning gains and the use of active-learning instruction. Although active learning has the potential to substantially improve student learning, this research suggests that active learning, as used by typical college biology instructors, is not associated with greater learning gains. We contend that most instructors lack the rich and nuanced understanding of teaching and learning that science education researchers have developed. Therefore, active learning as designed and implemented by typical college biology instructors may superficially resemble active learning used by education researchers, but lacks the constructivist elements necessary for improving learning.

  13. Information theory in systems biology. Part II: protein-protein interaction and signaling networks.

    PubMed

    Mousavian, Zaynab; Díaz, José; Masoudi-Nejad, Ali

    2016-03-01

    By the development of information theory in 1948 by Claude Shannon to address the problems in the field of data storage and data communication over (noisy) communication channel, it has been successfully applied in many other research areas such as bioinformatics and systems biology. In this manuscript, we attempt to review some of the existing literatures in systems biology, which are using the information theory measures in their calculations. As we have reviewed most of the existing information-theoretic methods in gene regulatory and metabolic networks in the first part of the review, so in the second part of our study, the application of information theory in other types of biological networks including protein-protein interaction and signaling networks will be surveyed.

  14. Cluster subtypes on the California Verbal Learning Test-Second Edition (CVLT-II) in a traumatic brain injury sample.

    PubMed

    DeJong, Joy; Donders, Jacobus

    2010-11-01

    Subtypes of learning and memory on the California Verbal Learning Test-Second Edition (CVLT-II; Delis, Kramer, Kaplan, & Ober, 2000) were examined in a clinical sample of 223 persons with traumatic brain injury (TBI), screened to remove individuals with complicating premorbid (e.g., psychiatric) or comorbid (e.g., financial compensation-seeking) histories. The z scores from 4 key CVLT-II variables were entered into a two-stage cluster analysis. These variables were selected to represent 4 latent constructs, identified in a recent confirmatory factor analysis: List A1 (Attention Span), List A5 (Learning Efficiency), Long Delay Free Recall (Delayed Memory), and False Positives (Inaccurate Memory). Six reliable subtypes were found (similar to those in the standardization sample) that were differentiated by both level and pattern of performance, with differences in level of performance meaningfully related to length of coma. In conclusion, the impact of TBI on CVLT-II performance can be manifested in various patterns that are not specifically unique, but are affected by injury severity. PMID:20408004

  15. Sensitive spectrophotometric determination of Co(II) using dispersive liquid-liquid micro-extraction method in soil samples.

    PubMed

    Hasanpour, Foroozan; Hadadzadeh, Hassan; Taei, Masoumeh; Nekouei, Mohsen; Mozafari, Elmira

    2016-05-01

    Analytical performance of conventional spectrophotometer was developed by coupling of effective dispersive liquid-liquid micro-extraction method with spectrophotometric determination for ultra-trace determination of cobalt. The method was based on the formation of Co(II)-alpha-benzoin oxime complex and its extraction using a dispersive liquid-liquid micro-extraction technique. During the present work, several important variables such as pH, ligand concentration, amount and type of dispersive, and extracting solvent were optimized. It was found that the crucial factor for the Co(II)-alpha benzoin oxime complex formation is the pH of the alkaline alcoholic medium. Under the optimized condition, the calibration graph was linear in the ranges of 1.0-110 μg L(-1) with the detection limit (S/N = 3) of 0.5 μg L(-1). The preconcentration operation of 25 mL of sample gave enhancement factor of 75. The proposed method was applied for determination of Co(II) in soil samples. PMID:27040110

  16. Sensitive spectrophotometric determination of Co(II) using dispersive liquid-liquid micro-extraction method in soil samples.

    PubMed

    Hasanpour, Foroozan; Hadadzadeh, Hassan; Taei, Masoumeh; Nekouei, Mohsen; Mozafari, Elmira

    2016-05-01

    Analytical performance of conventional spectrophotometer was developed by coupling of effective dispersive liquid-liquid micro-extraction method with spectrophotometric determination for ultra-trace determination of cobalt. The method was based on the formation of Co(II)-alpha-benzoin oxime complex and its extraction using a dispersive liquid-liquid micro-extraction technique. During the present work, several important variables such as pH, ligand concentration, amount and type of dispersive, and extracting solvent were optimized. It was found that the crucial factor for the Co(II)-alpha benzoin oxime complex formation is the pH of the alkaline alcoholic medium. Under the optimized condition, the calibration graph was linear in the ranges of 1.0-110 μg L(-1) with the detection limit (S/N = 3) of 0.5 μg L(-1). The preconcentration operation of 25 mL of sample gave enhancement factor of 75. The proposed method was applied for determination of Co(II) in soil samples.

  17. Impact of processing method on recovery of bacteria from wipes used in biological surface sampling.

    PubMed

    Downey, Autumn S; Da Silva, Sandra M; Olson, Nathan D; Filliben, James J; Morrow, Jayne B

    2012-08-01

    Environmental sampling for microbiological contaminants is a key component of hygiene monitoring and risk characterization practices utilized across diverse fields of application. However, confidence in surface sampling results, both in the field and in controlled laboratory studies, has been undermined by large variation in sampling performance results. Sources of variation include controlled parameters, such as sampling materials and processing methods, which often differ among studies, as well as random and systematic errors; however, the relative contributions of these factors remain unclear. The objective of this study was to determine the relative impacts of sample processing methods, including extraction solution and physical dissociation method (vortexing and sonication), on recovery of Gram-positive (Bacillus cereus) and Gram-negative (Burkholderia thailandensis and Escherichia coli) bacteria from directly inoculated wipes. This work showed that target organism had the largest impact on extraction efficiency and recovery precision, as measured by traditional colony counts. The physical dissociation method (PDM) had negligible impact, while the effect of the extraction solution was organism dependent. Overall, however, extraction of organisms from wipes using phosphate-buffered saline with 0.04% Tween 80 (PBST) resulted in the highest mean recovery across all three organisms. The results from this study contribute to a better understanding of the factors that influence sampling performance, which is critical to the development of efficient and reliable sampling methodologies relevant to public health and biodefense.

  18. Effect of poppy seed consummation on the positive results of opiates screening in biological samples.

    PubMed

    Jankovicová, Katarína; Ulbrich, Pavol; Fuknová, Mária

    2009-04-01

    Poppy seed is a popular substance of many traditional Slovak cakes. We can eat quite great amount of it, sometimes more than 50 g. Existing problem in interpreting the results of opiate urine analysis in case of drug abuse arises from the natural occurrence of opiate alkaloids in poppy seed. Interpretation of morphine presence in urine sample is in some cases a problem because morphine present in the urine sample may come from different "sources". The presence of additional, respectively, other opiate in urine sample is significant help when interpreting the presence of morphine. We used poppy seed bought in supermarket for our experiment. Presence of morphine and codeine was determined in poppy seed extracts, whereas the concentration of majority opiate-morphine was 0.9 mg/100 g (9 ppm). This poppy seed was used for two series of experiment-poppy seed consummation, where four persons consumed 100g of poppy seed in the first series and 50 g in the second series. Urine samples were taken in regular 1h intervals where first urine sample was given for testing 3 h after consummation. Concentrations of total opiates were determined in each urine sample by screening examination. Morphine concentrations were determined in selected urine samples using GC/MS with internal standard.

  19. Computed tomography and X-ray fluorescence CT of biological samples

    NASA Astrophysics Data System (ADS)

    Pereira, G. R.; Anjos, M. J.; Rocha, H. S.; Faria, P.; Pérez, C. A.; Lopes, R. T.

    2007-10-01

    Transmission microtomography ( μCT) and X-ray fluorescence microtomography (XRF μCT) are complementary and noninvasive techniques used for sample characterization. μCT provide information on the attenuation coefficients, while XRF μCT can provide the distribution of all elements in a sample. XRF μCT is a noninvasive technique, based on the detection of X-ray fluorescence emitted by the elements in the sample, and it is used to complement other techniques for sample characterization. The experiments were performed at the X-Ray Fluorescence (XRF) beamline of the Brazilian Synchrotron Light Laboratory (LNLS), Campinas, Brazil. A monochromatic beam of 9.8 keV was used for excitation of the elements within samples and the fluorescence photons were detected by an HPGe detector. The incident beam was monitored by an ionization chamber and a fast scintillator detector was used to detect the transmitted radiation. In this work, several intestine and breast tissue samples were investigated in order to verify the concentration of some elements correlated with the characteristics and pathology of each tissue observed by transmission μCT. All XRF μCT were reconstructed using a filtered back-projection algorithm. In those samples the elements Zn, Cu, and Fe were observed.

  20. Automated Sample Exchange Robots for the Structural Biology Beam Lines at the Photon Factory

    SciTech Connect

    Hiraki, Masahiko; Watanabe, Shokei; Yamada, Yusuke; Matsugaki, Naohiro; Igarashi, Noriyuki; Gaponov, Yurii; Wakatsuki, Soichi

    2007-01-19

    We are now developing automated sample exchange robots for high-throughput protein crystallographic experiments for onsite use at synchrotron beam lines. It is part of the fully automated robotics systems being developed at the Photon Factory, for the purposes of protein crystallization, monitoring crystal growth, harvesting and freezing crystals, mounting the crystals inside a hutch and for data collection. We have already installed the sample exchange robots based on the SSRL automated mounting system at our insertion device beam lines BL-5A and AR-NW12A at the Photon Factory. In order to reduce the time required for sample exchange further, a prototype of a double-tonged system was developed. As a result of preliminary experiments with double-tonged robots, the sample exchange time was successfully reduced from 70 seconds to 10 seconds with the exception of the time required for pre-cooling and warming up the tongs.

  1. Accelerating analysis for metabolomics, drugs and their metabolites in biological samples using multidimensional gas chromatography.

    PubMed

    Mitrevski, Blagoj S; Kouremenos, Konstantinos A; Marriott, Philip J

    2009-05-01

    Gas chromatography (GC) with mass spectrometry (MS) is one of the great enabling analytical tools available to the chemical and biochemical analyst for the measurement of volatile and semi-volatile compounds. From the analysis result, it is possible to assess progress in chemical reactions, to monitor environmental pollutants in a wide range of soil, water or air samples, to determine if an athlete or horse trainer has contravened doping laws, or if crude oil has migrated through subsurface rock to a reservoir. Each of these scenarios and samples has an associated implementation method for GC-MS. However, few samples and the associated interpretation of data is as complex or important as biochemical sample analysis for trace drugs or metabolites. Improving the analysis in both the GC and MS domains is a continual search for better separation, selectivity and sensitivity. Multidimensional methods are playing important roles in providing quality data to address the needs of analysts.

  2. Sample Preparation Approaches for iTRAQ Labeling and Quantitative Proteomic Analyses in Systems Biology.

    PubMed

    Spanos, Christos; Moore, J Bernadette

    2016-01-01

    Among a variety of global quantification strategies utilized in mass spectrometry (MS)-based proteomics, isobaric tags for relative and absolute quantitation (iTRAQ) are an attractive option for examining the relative amounts of proteins in different samples. The inherent complexity of mammalian proteomes and the diversity of protein physicochemical properties mean that complete proteome coverage is still unlikely from a single analytical method. Numerous options exist for reducing protein sample complexity and resolving digested peptides prior to MS analysis. Indeed, the reliability and efficiency of protein identification and quantitation from an iTRAQ workflow strongly depend on sample preparation upstream of MS. Here we describe our methods for: (1) total protein extraction from immortalized cells; (2) subcellular fractionation of murine tissue; (3) protein sample desalting, digestion, and iTRAQ labeling; (4) peptide separation by strong cation-exchange high-performance liquid chromatography; and (5) peptide separation by isoelectric focusing.

  3. Methodological issues affecting the study of fish parasites. II. Sampling method affects ectoparasite studies.

    PubMed

    Kvach, Yuriy; Ondračková, Markéta; Janáč, Michal; Jurajda, Pavel

    2016-08-31

    In this study, we assessed the impact of sampling method on the results of fish ectoparasite studies. Common roach Rutilus rutilus were sampled from the same gravel pit in the River Dyje flood plain (Czech Republic) using 3 different sampling methods, i.e. electrofishing, beach seining and gill-netting, and were examined for ectoparasites. Not only did fish caught by electrofishing have more of the most abundant parasites (Trichodina spp., Gyrodactylus spp.) than those caught by beach seining or gill-netting, they also had relatively rich parasite infracommunities, resulting in a significantly different assemblage composition, presumably as parasites were lost through handling and 'manipulation' in the net. Based on this, we recommend electrofishing as the most suitable method to sample fish for parasite community studies, as data from fish caught with gill-nets and beach seines will provide a biased picture of the ectoparasite community, underestimating ectoparasite abundance and infracommunity species richness. PMID:27596860

  4. neutron activation analysis using thermochromatography. II. thermochromatographic separation of elements in the analysis of geological samples

    SciTech Connect

    Sattarov, G.; Davydov, A.V.; Khamatov, S.; Kist, A.A.

    1986-07-01

    The use of gas thermochromatography (GTC) in the radioactivation analysis of difficulty soluble samples with a strongly activating substrate is discussed. The effect of sample coarseness and ore type on the rate of extraction of gold and accompanying elements was studied. The limits of detection of 22 elements were compared using neutron activation analysis with GTC and INAA. The analytical parameters of the procedure were estimated.

  5. Oxygen bomb combustion of biological samples for inductively coupled plasma optical emission spectrometry

    NASA Astrophysics Data System (ADS)

    Souza, Gilberto B.; Carrilho, Elma Neide V. M.; Oliveira, Camila V.; Nogueira, Ana Rita A.; Nóbrega, Joaquim A.

    2002-12-01

    A rapid sample preparation method is proposed for decomposition of milk powder, corn bran, bovine and fish tissues, containing certified contents of the analytes. The procedure involves sample combustion in a commercial stainless steel oxygen bomb operating at 25 bar. Most of the samples were decomposed within 5 min. Diluted nitric acid or water-soluble tertiary amines 10% v/v were used as absorption solutions. Calcium, Cu, K, Mg, Na, P, S and Zn were recovered with the bomb washings and determined by inductively coupled plasma optical emission spectrometry (ICP-OES). Ethanol mixed with paraffin was used as a combustion aid to allow complete combustion. A cooling step prior releasing of the bomb valve was employed to increase the efficiency of sample combustion. Iodine was also determined in milk samples spiked with potassium iodide to evaluate the volatilization and collection of iodine in amine CFA-C medium and the feasibility of its determination by ICP-OES with axial view configuration. Most of the element recoveries in the samples were between 91 and 105% and the certified and found contents exhibited a fair agreement at a 95% confidence level.

  6. Symmetry in the pigeon with sample and comparison stimuli in different locations. II.

    PubMed

    Swisher, Melissa; Urcuioli, Peter J

    2015-09-01

    Pigeons were trained on arbitrary (hue-form) and identity (hue-hue and form-form) successive matching with center-key samples and left-key comparisons. Later, they were tested on form-hue (symmetry) probe trials that were structured either in the different-locations fashion as the baseline trials (viz., center-key samples and left-key comparisons) or with a constant location by using center-key samples and center-key comparisons. Three of four pigeons showed symmetry when the probe-trial samples and comparisons appeared in center- and left-key spatial locations, respectively, but none did when both appeared in one (center-key) location. Subsequently, pigeons previously tested with center-key samples and left-key comparisons were tested with those form-hue stimuli shown in the same (center-key) location, and vice versa for the other pigeons. None of the former pigeons showed symmetry on the second test even if they had on the first test. By contrast, two of three pigeons that had not shown symmetry with single-location samples and comparisons did so when those stimuli appeared in different (center- vs. left-key) locations. Taken together, these results show that symmetrical relations between the same, nominal matching stimuli depend on where those stimuli appear in testing vis-à-vis in training and, more generally, confirm that spatial location is part of the functional matching stimuli.

  7. [Adaptation and Neurosciences II: Biological, Psychological and Social Adaptation, and Psychopathology].

    PubMed

    Desseilles, Martin

    2016-01-01

    In this article, we address adaptation in relation to the neurosciences. Adaptation is examined at the individual as well as various environmental levels: biological, psychological, and social. We then briefly discuss, from a neuroscientific perspective, the concept of adaptation in relation to psychopathology, including attachment theory and the third wave of cognitive-behavioral therapies. PMID:27570964

  8. PERFORMANCE OF NORTH AMERICAN BIOREACTOR LANDFILLS: II. CHEMICAL AND BIOLOGICAL CHARACTERISTICS

    EPA Science Inventory

    The objective of this research was to examine the performance of five North American bioreactor landfills. This paper represents the second of a two part series and addresses biological and chemical aspects of bioreactor performance including gas production and management, and l...

  9. The Didactics of Biology. A Selected Bibliography for 1979. Part I [and] Part II.

    ERIC Educational Resources Information Center

    Altmann, Antonin, Ed.; Lipertova, Pavla, Ed.

    Selected articles on various aspects of biology teaching published in 1979 have been annotated in this two-part bibliography. Entries from 18 journals representing 11 different countries are presented according to a topic area classification scheme listed in the table of contents. Countries represented include: Australia; Bulgaria; Czechoslovakia;…

  10. On the vicissitudes of Freud's early mothering. II: Alienation from his biological mother.

    PubMed

    Hardin, H T

    1988-01-01

    Continuing an exploration of the vicissitudes of Freud's early mothering experience, this paper utilizes three clinical examples to focus on alienation between Freud and his biological mother. This state of affairs is demonstrated in his reticence about her, his concern about dying before her, and, finally, in his perception of daughter Anna's being his surrogate mourner at the time of his mother's death.

  11. Biology-Chemistry-Physics, Teachers' Guide, a Three-Year Sequence, Parts I and II.

    ERIC Educational Resources Information Center

    Scott, Arthur; And Others

    This is one of two teacher's guides for a three-year integrated biology, chemistry, and physics course being prepared by the Portland Project Committee. This committee reviewed and selected material developed by the national course improvement groups--Physical Science Study Committee, Chemical Bond Approach, Chemical Education Materials Study,…

  12. Low Budget Biology II: A Collection of Low Cost Labs and Activities.

    ERIC Educational Resources Information Center

    Wartski, Bert; Wartski, Lynn Marie

    This document contains 13 low budget labs, demonstrations, and activities to be used in the biology classroom. Each activity has a teacher preparation section which states the purpose of each lab, some basic information, a list of materials and what they do, and how to prep the different solutions and chemicals. All labs are designed for a…

  13. Synthesis, spectroscopic characterization and biological activities of N4O2 Schiff base ligand and its metal complexes of Co(II), Ni(II), Cu(II) and Zn(II)

    NASA Astrophysics Data System (ADS)

    Al-Resayes, Saud I.; Shakir, Mohammad; Abbasi, Ambreen; Amin, Kr. Mohammad Yusuf; Lateef, Abdul

    The Schiff base ligand, bis(indoline-2-one)triethylenetetramine (L) obtained from condensation of triethylenetetramine and isatin was used to synthesize the complexes of type, [ML]Cl2 [M = Co(II), Ni(II), Cu(II) and Zn(II)]. L was characterized on the basis of the results of elemental analysis, FT-IR, 1H and 13C NMR, mass spectroscopic studies. The stoichiometry, bonding and stereochemistries of complexes were ascertained on the basis of results of elemental analysis, magnetic susceptibility values, molar conductance and various spectroscopic studies. EPR, UV-vis and magnetic moments revealed an octahedral geometry for complexes. L and its Cu(II) and Zn(II) complexes were screened for their antibacterial activity. Analgesic activity of Cu(II) and Zn(II) complexes was also tested in rats by tail flick method. Both complexes were found to possess good antibacterial and moderate analgesic activity.

  14. Sampling artifact in volume weighted velocity measurement. II. Detection in simulations and comparison with theoretical modeling

    NASA Astrophysics Data System (ADS)

    Zheng, Yi; Zhang, Pengjie; Jing, Yipeng

    2015-02-01

    Measuring the volume weighted velocity power spectrum suffers from a severe systematic error due to imperfect sampling of the velocity field from the inhomogeneous distribution of dark matter particles/halos in simulations or galaxies with velocity measurement. This "sampling artifact" depends on both the mean particle number density n¯P and the intrinsic large scale structure (LSS) fluctuation in the particle distribution. (1) We report robust detection of this sampling artifact in N -body simulations. It causes ˜12 % underestimation of the velocity power spectrum at k =0.1 h /Mpc for samples with n¯ P=6 ×10-3 (Mpc /h )-3 . This systematic underestimation increases with decreasing n¯P and increasing k . Its dependence on the intrinsic LSS fluctuations is also robustly detected. (2) All of these findings are expected based upon our theoretical modeling in paper I [P. Zhang, Y. Zheng, and Y. Jing, Sampling artifact in volume weighted velocity measurement. I. Theoretical modeling, arXiv:1405.7125.]. In particular, the leading order theoretical approximation agrees quantitatively well with the simulation result for n¯ P≳6 ×10-4 (Mpc /h )-3 . Furthermore, we provide an ansatz to take high order terms into account. It improves the model accuracy to ≲1 % at k ≲0.1 h /Mpc over 3 orders of magnitude in n¯P and over typical LSS clustering from z =0 to z =2 . (3) The sampling artifact is determined by the deflection D field, which is straightforwardly available in both simulations and data of galaxy velocity. Hence the sampling artifact in the velocity power spectrum measurement can be self-calibrated within our framework. By applying such self-calibration in simulations, it is promising to determine the real large scale velocity bias of 1013M⊙ halos with ˜1 % accuracy, and that of lower mass halos with better accuracy. (4) In contrast to suppressing the velocity power spectrum at large scale, the sampling artifact causes an overestimation of the velocity

  15. SAR of Cu (II) thiosemicarbazone complexes as hypoxic imaging agents: MM3 analysis and prediction of biologic properties.

    PubMed

    Singh, Sweta; Tiwari, Anjani K; Ojha, Himanshu; Kumar, Nitin; Singh, Bachcha; Mishra, Anil K

    2010-02-01

    Copper(II) bis(thiosemicarbazone) are very useful for blood flow and hypoxic imaging. The aim of this study was to identify structure-activity relationships (SARs) within a series of analogues with different substitution patterns in the ligands, in order to design improved hypoxia imaging agents and elucidate hypoxia selectivity mechanisms. Genetic algorithms (GAs) were used to develop specific copper metal-ligand force field parameters for the MM3 force-field calculations. These new parameters produced results in good agreement with experiment and previously reported copper metal-ligand parameters. A successful quantitative SAR (QSAR) for predicting the several classes of Cu(II)-chelating ligands was built using a training set of 21 Cu(II) complexes. The QSAR exhibited a correlation between the predicted and experimental test set. The QSAR preformed with great accuracy; r(2) = 0.95 and q(2) = 0.90 utilizing a leave-one-out cross-validation with multiple linear regression analysis to find correlation between different calculated molecular descriptors of these complexes. The final QSAR mathematical models were found as the following: Log P = {3.01698 (+/-0.0590)} - LUMO {0.1248 (+/-0.068)} + MR {0.3219 (+/-0.086)} n = 21 |r| = 0.972 s = 0.188 F = 98.102 The resulting models could act as an efficient strategy for estimating the hypoxic conditions through imaging and provide some insights into the structural features related to the biological activity of these compounds.

  16. Methods for collection and analysis of aquatic biological and microbiological samples

    USGS Publications Warehouse

    Britton, Linda J., (Edited By); Greeson, Phillip E.

    1989-01-01

    Chapter A4 contains methods used by the U.S. Geological Survey to collect, preserve, and analyze water to determine its biological and microbiological properties. Part 1 consists of detailed descriptions of more than 45 individual methods, including those for bacteria, phytoplankton, zooplankton, seston, periphyton, macrophytes, benthic invertebrates, fish and other vertebrates, cellular contents, productivity, and bioassays. Each method is summarized, and the applications, interferences, apparatus, reagents, analyses, calculations, reporting of results, precisions, and references are given. Part 2 consists of a glossary. Part 3 is a list of taxonomic references.

  17. Shiga-like toxin II-related cytotoxins in Citrobacter freundii strains from humans and beef samples.

    PubMed

    Schmidt, H; Montag, M; Bockemühl, J; Heesemann, J; Karch, H

    1993-02-01

    By hybridizing colonies grown from 928 individual stool samples of patients suffering from diarrhea with oligonucleotide probes 772 and 849 complementary to Shiga-like toxin I (SLT-I) and SLT-II gene sequences, respectively, we identified two strains that hybridized with probe 849, which biochemical identification revealed as Citrobacter freundii. An additional five slt-II probe-positive isolates were screened from 81 beef samples. Polymerase chain reaction analysis and restriction of amplified products provided evidence for slt-II-related genes in all seven strains. From C. freundii LM 76, the genes encoding the A and B subunits were cloned in pUC 18 vectors and sequenced. The gene encoding the A subunit differed from that of Escherichia coli slt-IIvhc in 4 bases, resulting in two amino acid residue differences. In 11, 13, and 11 nucleotides, differentiation of slt-IIA, slt-IIcA, and vtx2haA, respectively, was found. These differences affected the predicted amino acid sequence as follows: there were six amino acid differences with SLT-IIA, five with SLT-IIcA, and four with VTx2haA. The nucleotide sequence of the gene encoding the B subunit is identical to slt-IIvhcB and differed from slt-IIcB and vtx2haB by only a single nucleotide base, but this resulted in a predicted amino acid sequence identical to that reported for these toxins. We therefore termed the toxin genes C. freundii slt-IIcA and slt-IIcB. Culture filtrates inoculated with material from the colonies from primary cultures were cytotoxic to Vero cells. Neutralization assays with antisera to E. coli SLT-I, SLT-II, and SLT-IIvhc revealed that antibodies against SLT-IIvhc reduced the C. freundii cytotoxic activity specifically and to the same degree as with the E. coli SLT-IIvhc control strain. In five of the seven strains tested, subcultivation on both a liquid or solid medium resulted in loss of cytotoxic activity. With polymerase chain reaction, we demonstrated that loss of cytotoxic activity ran

  18. Preparation, characterisation and study of in vitro biologically active azamacrocyclic Cu(II) dicarboxylate complexes

    NASA Astrophysics Data System (ADS)

    Antonijević-Nikolić, Mirjana; Antić-Stanković, Jelena; Tanasković, Sladjana B.; Korabik, Maria J.; Gojgić-Cvijović, Gordana; Vučković, Gordana

    2013-12-01

    New cationic Cu(II) complexes with N, N‧, N″, N″‧-tetrakis(2-pyridylmethyl)-1,4,8,11-tetraazacyclotetradecane (tpmc) and aliphatic dicarboxylic acids: pentanedioic (glutaric acid = glutH2), hexanedioic acid (adipic acid = adipH2) and decanedioic acid (sebacic acid = sebH2) of general formula [Cu4(L)(tpmc)2](ClO4)6·xH2O, L = glut, x = 2; L = adip, x = 7; L = seb, x = 6 were isolated. Their composition and charges are proposed based on elemental analyses and molar conductivity measurements. By the comparison of their UV-Vis, reflectance, FTIR and EPR spectral data, CV and SQUID magnetic measurements, with those for the complex with butanedioic acid (succinic acid = succH2) of known molecular structure and analysis of LC/MS spectra, geometry with two [Cu2tpmc]4+ units bridged by dicarboxylate dianion engaging all oxygens is proposed. Within units, Cu(II) ions are also bridged with N portion of cyclam ring. All four complexes were screened to in vitro antimicrobial and cytotoxic activity along with free primary and secondary ligands, Cu(II) salt and solvent controls. Detected antibacterial and cytotoxic activity for the complexes was enhanced in most cases than the corresponding controls.

  19. Measurement of the unstained biological sample by a novel scanning electron generation X-ray microscope based on SEM.

    PubMed

    Ogura, Toshihiko

    2009-08-01

    We introduced a novel X-ray microscope system based on scanning electron microscopy using thin film, which enables the measurement of unstained biological samples without damage. An unstained yeast sample was adsorbed under a titanium (Ti)-coated silicon nitride (Si3N4) film 90 nm thick. The X-ray signal from the film was detected by an X-ray photodiode (PD) placed below the sample. With an electron beam at 2.6 kV acceleration and 6.75 nA current, the yeast image is obtained using the X-ray PD. The image is created by soft X-rays from the Ti layer. The Ti layer is effective in generating the characteristic 2.7-nm wavelength X-rays by the irradiation of electrons. Furthermore, we investigated the electron trajectory and the generation of the characteristic X-rays within the Ti-coated Si3N4 film by Monte Carlo simulation. Our system can be easily utilized to observe various unstained biological samples of cells, bacteria, and viruses.

  20. Supercritical fluid extraction and ultra performance liquid chromatography of respiratory quinones for microbial community analysis in environmental and biological samples.

    PubMed

    Hanif, Muhammad; Atsuta, Yoichi; Fujie, Koichi; Daimon, Hiroyuki

    2012-03-05

    Microbial community structure plays a significant role in environmental assessment and animal health management. The development of a superior analytical strategy for the characterization of microbial community structure is an ongoing challenge. In this study, we developed an effective supercritical fluid extraction (SFE) and ultra performance liquid chromatography (UPLC) method for the analysis of bacterial respiratory quinones (RQ) in environmental and biological samples. RQ profile analysis is one of the most widely used culture-independent tools for characterizing microbial community structure. A UPLC equipped with a photo diode array (PDA) detector was successfully applied to the simultaneous determination of ubiquinones (UQ) and menaquinones (MK) without tedious pretreatment. Supercritical carbon dioxide (scCO(2)) extraction with the solid-phase cartridge trap proved to be a more effective and rapid method for extracting respiratory quinones, compared to a conventional organic solvent extraction method. This methodology leads to a successful analytical procedure that involves a significant reduction in the complexity and sample preparation time. Application of the optimized methodology to characterize microbial communities based on the RQ profile was demonstrated for a variety of environmental samples (activated sludge, digested sludge, and compost) and biological samples (swine and Japanese quail feces).

  1. Detection of motile micro-organisms in biological samples by means of a fully automated image processing system

    NASA Astrophysics Data System (ADS)

    Alanis, Elvio; Romero, Graciela; Alvarez, Liliana; Martinez, Carlos C.; Hoyos, Daniel; Basombrio, Miguel A.

    2001-08-01

    A fully automated image processing system for detection of motile microorganism is biological samples is presented. The system is specifically calibrated for determining the concentration of Trypanosoma Cruzi parasites in blood samples of mice infected with Chagas disease. The method can be adapted for use in other biological samples. A thin layer of blood infected by T. cruzi parasites is examined in a common microscope in which the images of the vision field are taken by a CCD camera and temporarily stored in the computer memory. In a typical field, a few motile parasites are observable surrounded by blood red cells. The parasites have low contrast. Thus, they are difficult to detect visually but their great motility betrays their presence by the movement of the nearest neighbor red cells. Several consecutive images of the same field are taken, decorrelated with each other where parasites are present, and digitally processed in order to measure the number of parasites present in the field. Several fields are sequentially processed in the same fashion, displacing the sample by means of step motors driven by the computer. A direct advantage of this system is that its results are more reliable and the process is less time consuming than the current subjective evaluations made visually by technicians.

  2. Synthesis, characterization and biological activity of some new VO(IV), Co(II), Ni(II), Cu(II) and Zn(II) complexes of chromone based NNO Schiff base derived from 2-aminothiazole

    NASA Astrophysics Data System (ADS)

    Kalanithi, M.; Kodimunthiri, D.; Rajarajan, M.; Tharmaraj, P.

    2011-11-01

    Coordination compounds of VO(IV), Co(II), Ni(II), Cu(II) and Zn(II) with the Schiff base obtained through the condensation of 2-aminothiazole with 3-formyl chromone were synthesized. The compounds were characterized by 1H, 13C NMR, UV-Vis, IR, Mass, EPR, molar conductance and magnetic susceptibility measurements. The Cu(II) complex possesses tetrahedrally distorted square planar geometry whereas Co(II), Ni(II), and Zn(II) show distorted tetrahedral geometry. The VO(IV) complex shows square pyramidal geometry. The cyclic voltammogram of Cu (II) complex showed a well defined redox couple Cu(II)/Cu(I) with quasireversible nature. The antimicrobial activity against the species Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Candida albigans and Aspergillus niger was screened and compared to the activity of the ligand. Emission spectrum was recorded for the ligand and the metal(II) complexes. The second harmonic generation (SHG) efficiency was measured and found to have one fourth of the activity of urea. The SEM image of the copper(II) complex implies that the size of the particles is 2 μm.

  3. Synthesis, characterization and biological activity of some new VO(IV), Co(II), Ni(II), Cu(II) and Zn(II) complexes of chromone based NNO Schiff base derived from 2-aminothiazole.

    PubMed

    Kalanithi, M; Kodimunthiri, D; Rajarajan, M; Tharmaraj, P

    2011-11-01

    Coordination compounds of VO(IV), Co(II), Ni(II), Cu(II) and Zn(II) with the Schiff base obtained through the condensation of 2-aminothiazole with 3-formyl chromone were synthesized. The compounds were characterized by (1)H, (13)C NMR, UV-Vis, IR, Mass, EPR, molar conductance and magnetic susceptibility measurements. The Cu(II) complex possesses tetrahedrally distorted square planar geometry whereas Co(II), Ni(II), and Zn(II) show distorted tetrahedral geometry. The VO(IV) complex shows square pyramidal geometry. The cyclic voltammogram of Cu (II) complex showed a well defined redox couple Cu(II)/Cu(I) with quasireversible nature. The antimicrobial activity against the species Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Candida albigans and Aspergillus niger was screened and compared to the activity of the ligand. Emission spectrum was recorded for the ligand and the metal(II) complexes. The second harmonic generation (SHG) efficiency was measured and found to have one fourth of the activity of urea. The SEM image of the copper(II) complex implies that the size of the particles is 2 μm.

  4. Validity of extracellular water assessment with saliva samples using plasma as the reference biological fluid.

    PubMed

    Matias, Catarina N; Silva, Analiza M; Santos, Diana A; Gobbo, Luis A; Schoeller, Dale A; Sardinha, Luís B

    2012-11-01

    Extracellular water (ECW) assessment is based on dilution techniques, commonly using blood sampling. However, plasma collection is an invasive procedure. We aimed to validate the use of saliva for ECW estimation by the bromide dilution technique using plasma as the reference method, in a sample of elite athletes. A total of 89 elite athletes with a mean age of 20.4 ± 4.4 years were evaluated. Baseline samples were collected before sodium bromide oral dose administration, and enriched samples were collected 3 h post-dose administration. The bromide concentration was assessed by high-performance liquid chromatography. Comparison of means, concordance coefficient correlation (CCC), multiple regression and Bland-Altman analysis were performed. The ECW from saliva explained 91% of the variance in ECW by plasma with a standard error of estimation of 0.91 kg. The CCC between alternative and reference methods was 0.952. No significant trend was observed between the mean and difference of the methods, with limits of agreement ranging between -1.5 and 2.1 kg. These findings reveal that bromide dilution volume calculated from saliva samples is a valid noninvasive method for ECW assessment in elite athletes. PMID:22275182

  5. Ultra-weak photon emission from biological samples: definition, mechanisms, properties, detection and applications.

    PubMed

    Cifra, Michal; Pospíšil, Pavel

    2014-10-01

    This review attempts to summarize molecular mechanisms, spectral and intensity properties, detection techniques and applications of ultra-weak photon emission. Ultra-weak photon emission is the chemiluminescence from biological systems where electronically excited species are formed during oxidative metabolic or oxidative stress processes. It is generally accepted that photons are emitted (1) at near UVA, visible, and near IR spectral ranges from 350 to 1300nm and (2) at the intensity of photon emission in the range of several units to several hundreds (oxidative metabolic process) and several hundreds to several thousands (oxidative stress process) photons s(-1)cm(-2). Current development in detection using low-noise photomultiplier tubes and imaging using highly sensitive charge coupled device cameras allows temporal and spatial visualization of oxidative metabolic or oxidative stress processes, respectively. As the phenomenon of ultra-weak photon emission reflects oxidative metabolic or oxidative stress processes, it can be widely used as a non-invasive tool for monitoring of the physiological state of biological systems.

  6. On the modeling of equilibrium twin interfaces in a single-crystalline magnetic shape memory alloy sample. II: numerical algorithm

    NASA Astrophysics Data System (ADS)

    Wang, Jiong; Steinmann, Paul

    2016-05-01

    This is part II of this series of papers. The aim of the current paper was to solve the governing PDE system derived in part I numerically, such that the procedure of variant reorientation in a magnetic shape memory alloy (MSMA) sample can be simulated. The sample to be considered in this paper has a 3D cuboid shape and is subject to typical magnetic and mechanical loading conditions. To investigate the demagnetization effect on the sample's response, the surrounding space of the sample is taken into account. By considering the different properties of the independent variables, an iterative numerical algorithm is proposed to solve the governing system. The related mathematical formulas and some techniques facilitating the numerical calculations are introduced. Based on the results of numerical simulations, the distributions of some important physical quantities (e.g., magnetization, demagnetization field, and mechanical stress) in the sample can be determined. Furthermore, the properties of configurational force on the twin interfaces are investigated. By virtue of the twin interface movement criteria derived in part I, the whole procedure of magnetic field- or stress-induced variant reorientations in the MSMA sample can be properly simulated.

  7. A combined method for correlative 3D imaging of biological samples from macro to nano scale

    PubMed Central

    Kellner, Manuela; Heidrich, Marko; Lorbeer, Raoul-Amadeus; Antonopoulos, Georgios C.; Knudsen, Lars; Wrede, Christoph; Izykowski, Nicole; Grothausmann, Roman; Jonigk, Danny; Ochs, Matthias; Ripken, Tammo; Kühnel, Mark P.; Meyer, Heiko

    2016-01-01

    Correlative analysis requires examination of a specimen from macro to nano scale as well as applicability of analytical methods ranging from morphological to molecular. Accomplishing this with one and the same sample is laborious at best, due to deformation and biodegradation during measurements or intermediary preparation steps. Furthermore, data alignment using differing imaging techniques turns out to be a complex task, which considerably complicates the interconnection of results. We present correlative imaging of the accessory rat lung lobe by combining a modified Scanning Laser Optical Tomography (SLOT) setup with a specially developed sample preparation method (CRISTAL). CRISTAL is a resin-based embedding method that optically clears the specimen while allowing sectioning and preventing degradation. We applied and correlated SLOT with Multi Photon Microscopy, histological and immunofluorescence analysis as well as Transmission Electron Microscopy, all in the same sample. Thus, combining CRISTAL with SLOT enables the correlative utilization of a vast variety of imaging techniques. PMID:27759114

  8. The REFLEX II Galaxy Cluster sample: mock catalogues and clustering analysis

    NASA Astrophysics Data System (ADS)

    Balaguera-Antolinez, Andres; Sanchez, Ariel G.; Bohringer, Hans

    2012-09-01

    We present results of the analysis of abundance and clustering from the new ROSAT-ESO Flux-Limited X-Ray (REFLEX) II galaxy cluster catalogue. To model the covariance matrix of the different statistics, we have created a set of 100 mock galaxy cluster catalogues built from a suite large volume LambdaCDM N-Body simulations (L-BASICC and calibrated with the X-ray luminosity function. We discuss the calibration scheme and some implications regarding the cluster scaling relations, particularly, the link between mass and luminosity. Similarly we show the behavior of the clustering signal as a function of the X-ray luminosity and some cosmological implications.

  9. Selenium levels in related biological samples: human placenta, maternal and umbilical cord blood, hair and nails.

    PubMed

    Lorenzo Alonso, Maria José; Bermejo Barrera, Adela; Cocho de Juan, José Angel; Fraga Bermúdez, José María; Bermejo Barrera, Pilar

    2005-01-01

    A study on selenium levels has been carried out in human placenta, maternal and umbilical cord blood, hair and nails of a group of 50 mothers and in the hair of the newborns. The determinations were perfomed by electrothermal atomic absorption spectrometry. The selenium concentration obtained for each sample type was as follows: For the human placenta the values obtained were between 0.56 and 1.06 microg/g (mean +/- standard deviation: 0.81 +/- 0.02 microg/g). The levels for the umbilical cord blood were 51.1-104.2 microg/l (76.3 +/- 6.5 microg/l). For the maternal blood the values measured were between 57.3 and 117.9 microg/l (90.0 +/- 15.2 microg/l), and for hair and nails were 0.22-1.5 microg/g (0.60 +/- 0.37 microg/g) and 0.46-1.57 microg/g (0.90 +/- 0.27 microg/g), respectively. For the hair of the newborns the values obtained were between 0.40 and 2.53 microg/g (1.04 +/- 0.48 microg/g). The effect of different variables as age, habitat, nutritional index or gestation age of the mothers on the selenium concentration in the samples was studied. The influence of the habitat is significant with a confidence level of 95% for the selenium concentration in maternal blood and umbilical cord blood samples. The influence of the mothers' age is significant with a confidence level of 95% for the selenium concentration in the umbilical cord blood samples. For the placenta samples, the effect of the nutritional index is significant with a confidence level of 95%. There is a positive correlation between samples of umbilical cord blood and the newborns' hair, between placenta and umbilical cord, and between cord blood and maternal blood.

  10. Periodontal Research: Basics and beyond – Part II (Ethical issues, sampling, outcome measures and bias)

    PubMed Central

    Avula, Haritha

    2013-01-01

    A good research beginning refers to formulating a well-defined research question, developing a hypothesis and choosing an appropriate study design. The first part of the review series has discussed these issues in depth and this paper intends to throw light on other issues pertaining to the implementation of research. These include the various ethical norms and standards in human experimentation, the eligibility criteria for the participants, sampling methods and sample size calculation, various outcome measures that need to be defined and the biases that can be introduced in research. PMID:24174747

  11. Joseph S. Weiner and the foundation of post-WW II human biology in the United Kingdom.

    PubMed

    Little, Michael A; Collins, Kenneth J

    2012-01-01

    Both the United States and the United Kingdom experienced a transformation in the science of physical anthropology from the period before World War II until the post-war period. In the United States, Sherwood L. Washburn is credited with being a leading figure in this transformation. In the United Kingdom, two individuals were instrumental in bringing about a similar change in the profession. These were Joseph S. Weiner at the University of Oxford and Nigel Barnicot at the University of London, with Weiner playing the principal role as leader in what Washburn called the "New Physical Anthropology," that is, the application of evolutionary theory, the de-emphasis on race classification, and the application of the scientific method and experimental approaches to problem solving. Weiner's contributions to physical anthropology were broad-based--climatic and work physiology, paleoanthropology, and human variation--in what became known as human biology in the U.K. and human adaptability internationally. This biographical essay provides evidence for the significant influence of J.S. Weiner on the post-war development of human biology (biological or physical anthropology) inthe U.K. PMID:23124506

  12. Two-photon fluorescent probes of biological Zn(II) derived from 7-hydroxyquinoline.

    PubMed

    Chen, Xiao-Yun; Shi, Jing; Li, Yi-Ming; Wang, Feng-Liang; Wu, Xu; Guo, Qing-Xiang; Liu, Lei

    2009-10-01

    A new fluorescent probe for monitoring Zn(2+) was synthesized based on the structure of 7-hydroxyquinoline. Compared with 8-substituted quinolines, the new probe exhibited higher selectivity for Zn(2+) over Cd(2+). Its fluorescence enhancement (14-fold) and nanomolar range sensitivity (K(d) = 0.117 nM) were favorable toward biological applications. Experiments also showed that a cell-permeable derivative of the new probe was potentially useful for two-photon imaging in living cells.

  13. Basics of particle therapy II biologic and dosimetric aspects of clinical hadron therapy.

    PubMed

    Rong, Yi; Welsh, James

    2010-12-01

    Besides photons and electrons, high-energy particles like protons, neutrons, ⁴He ions or heavier ions (C, Ne, etc) have been finding increasing applications in the treatment of radioresistant tumors and tumors located near critical structures. The main difference between photons and hadrons is their different biologic effect and depth-dose distribution. Generally speaking, protons are superior in dosimetric aspects whereas neutrons have advantages in biologic effectiveness because of the high linear energy transfer. In 1946 Robert Wilson first published the physical advantages in dose distribution of ion particles for cancer therapy. Since that time hadronic radiotherapy has been intensively studied in physics laboratories worldwide and clinical application have gradually come to fruition. Hadron therapy was made possible by the advances in accelerator technology, which increases the particles' energy high enough to place them at any depth within the patient's body. As a follow-up to the previous article Introduction to Hadrons, this review discusses certain biologic and dosimetric aspects of using protons, neutrons, and heavy charged particles for radiation therapy. PMID:20395789

  14. A Review on the Wettability of Dental Implant Surfaces II: Biological and Clinical Aspects

    PubMed Central

    Gittens, Rolando A.; Scheideler, Lutz; Rupp, Frank; Hyzy, Sharon L.; Geis-Gerstorfer, Jürgen; Schwartz, Zvi; Boyan, Barbara D.

    2014-01-01

    Dental and orthopaedic implants have been under continuous advancement to improve their interactions with bone and ensure a successful outcome for patients. Surface characteristics such as surface topography and surface chemistry can serve as design tools to enhance the biological response around the implant, with in vitro, in vivo and clinical studies confirming their effects. However, the comprehensive design of implants to promote early and long-term osseointegration requires a better understanding of the role of surface wettability and the mechanisms by which it affects the surrounding biological environment. This review provides a general overview of the available information about the contact angle values of experimental and of marketed implant surfaces, some of the techniques used to modify surface wettability of implants, and results from in vitro and clinical studies. We aim to expand the current understanding on the role of wettability of metallic implants at their interface with blood and the biological milieu, as well as with bacteria, and hard and soft tissues. PMID:24709541

  15. Detection of triglycerides using immobilized enzymes in food and biological samples

    NASA Astrophysics Data System (ADS)

    Raichur, Ashish; Lesi, Abiodun; Pedersen, Henrik

    1996-04-01

    A scheme for the determination of total triglyceride (fat) content in biomedical and food samples is being developed. The primary emphasis is to minimize the reagents used, simplify sample preparation and develop a robust system that would facilitate on-line monitoring. The new detection scheme developed thus far involves extracting triglycerides into an organic solvent (cyclohexane) and performing partial least squares (PLS) analysis on the NIR (1100 - 2500 nm) absorbance spectra of the solution. A training set using 132 spectra of known triglyceride mixtures was complied. Eight PLS calibrations were generated and were used to predict the total fat extracted from commercial samples such as mayonnaise, butter, corn oil and coconut oil. The results typically gave a correlation coefficient (r) of 0.99 or better. Predictions were typically within 90% and better at higher concentrations. Experiments were also performed using an immobilized lipase reactor to hydrolyze the fat extracted into the organic solvent. Performing PLS analysis on the difference spectra of the substrate and product could enhance specificity. This is being verified experimentally. Further work with biomedical samples is to be performed. This scheme may be developed into a feasible detection method for triglycerides in the biomedical and food industries.

  16. Determination of methenamine in biological samples by gas-liquid chromatography.

    PubMed

    Nieminen, A L; Kangas, L; Anttila, M; Hautoniemi, L

    1980-01-11

    Methenamine (hexamethylenetetramine), a urinary disinfectant, was determined in human plasma and urine by gas-liquid chromatography with a short (10 m) open-bore glass capillary column (split ratio 1:20) and nitrogen-selective detector. An almost quantitative recovery (92.1%) was achieved by simple dilution of water-containing samples (0.5 ml) with acetone (4.5 ml). After centrifugation an aliquot (2 microliter) of the supernatant was injected into the gas chromatograph. Selectivity and sensitivity of the nitrogen detector allowed the quantitation of unchanged methenamine in plasma and urine up to 24 h after a single therapeutic dose of 1 g. Reproducibility of the method was 7.6 and 2.1% (C.V.) in serum and urine, respectively. The time required for the analysis of one sample was approx. 2 min. Due to the simple extraction and short analysis time it was possible to analyze the samples concurrently with sample taking. Absorption of standard tablets and an enterosoluble preparation of methenamine hippurate was compared.

  17. Determination of alkylresorcinols and their metabolites in biological samples by gas chromatography-mass spectrometry.

    PubMed

    Wierzbicka, Roksana; Wu, Huaxing; Franek, Milan; Kamal-Eldin, Afaf; Landberg, Rikard

    2015-09-01

    High throughput GC-MS methods for quantification of alkylresorcinols (AR), biomarkers of whole grain wheat and rye intake, in plasma and adipose tissue and their metabolites in urine were developed and optimised. Alkylresorcinols in plasma (200μL) and adipose tissues (10-50mg) were extracted with diethyl ether, whereas main AR metabolites such as DHBA and DHPPA and newly identified metabolites in urine (50μL) were extracted with ethyl acetate after enzymatic deconjugation. All extracts were purified on OASIS-MAX solid phase extraction cartridges. Plasma and adipose tissue sample extracts were then derivatised with trifluoroacetic anhydride and reconstituted in undecane, whereas AR metabolites in urine samples were derivatised with BSTFA+TMCS (99:1, v/v, 100μL). Prepared samples were quantified by GC-MS (EI-SIM). Analysis of all compounds in the different matrices showed good selectivity, sensitivity, linearity, precision (<15% within and between batches), adequate recovery (75-108%), and short total run time (10-12min). The methods developed are applicable to large-scale sample sets such as epidemiological studies. PMID:26218771

  18. Quantitation of Bacillus clausii in biological samples by real-time polymerase chain reaction.

    PubMed

    Perotti, Mario; Mancini, Nicasio; Cavallero, Annalisa; Carletti, Silvia; Canducci, Filippo; Burioni, Roberto; Clementi, Massimo

    2006-06-01

    A real-time PCR assay targeting the highly specific erm34 sequence of Bacillus clausii DNA was developed and optimized. The quantitative assay showed a sensitivity level of 10(2) CFU/microl of sample. The method may represent a useful tool for monitoring the role of B. clausii as probiotic in vivo. PMID:16318892

  19. Measuring effective radium concentration with large numbers of samples. Part II--general properties and representativity.

    PubMed

    Girault, Frédéric; Perrier, Frédéric

    2012-11-01

    Effective radium concentration EC(Ra), product of radium concentration and radon emanation, is the source term for radon release into the pore space of rocks and the environment. Over a period of three years, we performed more than 6000 radon-222 accumulation experiments in the laboratory with scintillation flasks and SSNTDs and we obtained experimental EC(Ra) values from more than 1570 rock and soil samples. With this method, which allowed the measurement of EC(Ra) from large numbers of samples with sufficient accuracy and uncertainty, as detailed in the companion paper, the dependence of the emanation factor on temperature and moisture content is revisited. In addition, with such a large EC(Ra) dataset, dispersion of EC(Ra) can be studied at sample-scale (cm to dm) and at scarp-scale (m to tens of m). Furthermore, we are able to discuss the representativity of obtained EC(Ra) values at field-scale, and to investigate the spatial variations of EC(Ra) over kilometric scales, within geological formations and across formations and faults. This experimental study opens new perspectives in the understanding of radium geochemistry and illustrates the importance of studying the radon source term with large numbers of samples for the modelling of geological and environmental processes, and also for the assessment of the radon health hazard.

  20. Population and Family Education. Book II. Draft Sample Instructional Materials. Social Studies.

    ERIC Educational Resources Information Center

    United Nations Educational, Scientific, and Cultural Organization, Bangkok (Thailand). Regional Office for Education in Asia and Oceania.

    Produced by participants at the Unesco Regional workshop on Population and Family Education held in Bangkok, Thailand, in October 1970, the instructional materials intended for elementary and secondary students are to be considered sample first-draft materials usable for reference purposes by groups responsible for designing population education…