bluuebunny/crossref_metadata_2025_split huggingface dataset:
Staffing Benchmarks for Clinical Laboratories: A College of American Pathologists Q-Probes Study of Laboratory Staffing at 98 Institutions
Authors: Jones Bruce A. , Darcy Teresa , Souers Rhona J. , Meier Frederick A. 
Published: January 2012

Context.—Publicly available information concerning laboratory staffing benchmarks is scarce. One of the few publications on this topic summarized the findings of a Q-Probes study performed in 2004. This publication reports a similar survey with data collected in 2010.Objective.—To assess the relationship between staffing levels in specified laboratory sections and test volumes in these sections and quantify management span of control.Design.—The study defined 4 laboratory sections: anatomic pathology (including cytology), chemistry/hematology/immunology, microbiology, and transfusion medicine. It divided staff into 3 categories: management, nonmanagement (operational or bench staff), and doctoral (MD, PhD) supervisory staff. People in these categories were tabulated as full-time equivalents and exclusions specified. Tests were counted in uniform formats, specified for each laboratory section, according to Medicare rules for the bundling and unbundling of tests.Results.—Ninety-eight participating institutions provided data that showed significant associations between test volumes and staffing for all 4 sections. There was wide variation in productivity based on volume. There was no relationship between testing volume per laboratory section and management span of control. Higher productivity in chemistry/hematology/immunology was associated with a higher fraction of tests coming from nonacute care patients. In both the 2004 and 2010 studies, productivity was inseparably linked to test volume.Conclusions.—Higher test volume was associated with higher productivity ratios in chemistry/hematology/immunology and transfusion medicine sections. The impact of various testing services on productivity is section-specific.
Beryllium
Authors: Welch Laura S. 
Published: January 2012

AbstractBeryllium (Be) is one of the lightest of all metals and has one of the highest melting points of any light metal. Be metal is often used in aerospace and defense applications. Beryllium‐copper alloys are used in a wide variety of applications because of their electrical and thermal conductivity, high strength and hardness. Beryllium oxide acts as a good electrical insulator in some applications. Beryllium is associated with many different health effects in humans. At high levels it causes an acute form of lung disease. Among exposed individuals, a substantial fraction develop beryllium sensitization that can lead to a chronic lung disease known as berylliosis or chronic beryllium disease (CBD). Beryllium can cause skin disease and it has been classified as a human carcinogen. The chapter presents selected pulmonary and immunologic toxicity, inhalation‐carcinogenicity, exposure assessment and regulations of beryllium and beryllium compounds.
Magnesium, Calcium, Strontium, Barium, and Radium
Authors: Genter Mary Beth 
Published: January 2012

AbstractMagnesium, calcium, strontium, barium, and radium are among the alkaline‐earth metals, found in group IIA of the periodic table. Sir Humphrey Davy first described the electrochemical isolation of barium, magnesium, calcium, and strontium in 1808, and the isolation of a radium salt from waste uranium ore was described by the Curies in 1898. These metals are being presented separately from other metals in this edition. Beryllium, the lightest of the alkaline‐earth metals, is also being handled separately from the alkaline earths covered in this chapter, as beryllium has a number of special immunological and pulmonary toxicology concerns that impact workplace practices and industrial hygiene concerns. Topics covered include chemical and physical properties, production and use, exposure assessments, toxic effects, standards regulations, and guidelines for each matter.
Zinc and Cadmium Compounds
Authors: Jakubowski Marek 
Published: January 2012

AbstractZinc is widely distributed in nature. The methods for the determination of zinc in different environmental media (air, soil, water, waste, plants) have been reviewed. Zinc screenings are widely applied in the clinical practice. Zinc is essential for humans and animals. It is necessary for the function of numerous enzymes. The toxic effects of zinc have been associated with excess exposure. Zinc acetate has been found to be the most toxic of the compounds tested so far. It has been noticed that excessive zinc addition to food or water has resulted in a variety of systemic effects in the hematological and gastrointestinal systems. Genotoxicity studies conducted in a variety of test systems have failed to provide evidence for the mutagenicity. Zinc is relatively nontoxic, particularly if taken orally, except for the corrosive properties of some salts. The present chapter discusses chemical and physical properties, exposure assessment, guidelines of exposure and clinical cases for various zinc and zinc compounds.
Gallium, Indium, and Thallium
Authors: Repetto Guillermo , del Peso Ana 
Published: January 2012

AbstractThe chemical elements gallium, indium, and thallium belong to group IIIA in the periodic table. Unlike other metals, such as lead and arsenic, which have been featured prominently in toxicological folklore since antiquity, these are relative newcomers, discovered from 1861 to 1876. Since then, thallium has developed a well‐deserved reputation for its toxic properties and is recognized as a potent accidental, occupational, and environmental poison, with incidence in cases of homicide and suicide. Although gallium and indium are not as toxic as thallium, their production and industrial use represent an important source of exposure, particularly in the increasing manufacture of semiconductor electronic devices. Gallium compounds particularly produce pulmonary toxicity. Indium compounds induce pulmonary toxicity and also nephrotoxicity, hepatotoxicity, and developmental toxicity, whereas thallium compounds act as general poisons. Some compounds are also capable of altering various cellular defense mechanisms involved in carcinogenesis. However, many aspects of the toxicity of individual compounds in human beings, including toxicokinetics, mechanisms of action, teratogenic potential, and the best treatment, remain to be elucidated.
Titanium, Zirconium, and Hafnium
Authors: Malczewska‐Toth Barbara 
Published: January 2012

AbstractTitanium, zirconium, and hafnium belong to the group IVB of the periodic table. A characteristic feature of these transition elements is the ease with which they form stable complex ions. Features that contribute to this ability are favorably high charge‐to‐radius ratios and the availability of unfilled d orbitals. The ability of forming metallic bonds is demonstrated by the existence of a wide variety of alloys among different transition metals. Other features of these metals are high densities, high melting points, and low vapor pressures. Within this group, these properties tend to increase with increasing atomic weight.This chapter discusses the chemical and physical properties followed by the toxicity of each chemical and compound in three sections: the first section provides details on titanium, the second section on zirconium, and the third section on hafnium. Tables present the atomic number, atomic weight, and natural isotopes of titanium, zirconium, and hafnium.
Using Mean Field Theory to Guide Biofunctional Materials Design
Authors: Freudenberg Uwe , Sommer Jens‐Uwe , Levental Kandice R. , Welzel Petra B. , Zieris Andrea , Chwalek Karolina , Schneider Katja , Prokoph Silvana , Prewitz Marina , Dockhorn Ron , Werner Carsten 
Published: January 2012

AbstractCell‐instructive characteristics of extracellular matrices (ECM) resulting from a subtle balance of biomolecular and biophysical signals must be recapitulated in engineered biomaterials to facilitate regenerative therapies. However, no material explored so far allows the independent tuning of the involved molecular and physical cues due to the inherent correlation between biopolymer concentration and material properties. Addressing the resulting challenge, a rational design strategy for ECM‐inspired biohybrid hydrogels based on multi‐armed poly(ethylene glycol) and heparin, adapting a mean field approach to identify conditions at which the balance of elastic, electrostatic, and excluded volume forces results in constant heparin concentrations within swollen polymer networks with gradually varied physical properties is introduced. Applying heparin‐based biofunctionalization schemes, multiple distinct combinations of matrix parameters could be identified to effectively stimulate the pro‐angiogenic state of human endothelial cells and the differentiation of human mesenchymal stem cells. The study demonstrates the power of joint theoretical and experimental efforts in creating bioactive materials with specifically and independently controllable characteristics.
The Effect of Ageing on Exciton Dynamics, Charge Separation, and Recombination in P3HT/PCBM Photovoltaic Blends
Authors: Deschler Felix , De Sio Antonietta , von Hauff Elizabeth , Kutka Peter , Sauermann Tobias , Egelhaaf Hans‐J. , Hauch Jens , Da Como Enrico 
Published: January 2012

AbstractA study of how light‐induced degradation influences the fundamental photophysical processes in the active layer of poly(3‐hexylthiophene)/[6,6]‐phenyl C61‐butyric acid methyl ester (P3HT/PCBM) solar cells is presented. Non‐encapsulated samples are systematically aged by exposure to AM 1.5 illumination in the presence of dry air for different periods of time. The extent of degradation is quantified by the relative loss in the absorption maximum of the P3HT, which is varied in the range 0% to 20%. For degraded samples an increasing loss in the number of excitons within the P3HT domains is observed with longer ageing periods. This loss occurs rapidly, within the first 15 ps after photoexcitation. A more pronounced decrease in the population of polarons than excitons is observed, which also occurs on a timescale of a few picoseconds. These observations, complemented by a quantitative analysis of the polaron and exciton population dynamics, unravel two primary loss mechanisms for the performances of aged P3HT/PCBM solar cells. One is an initial ultrafast decrease in the polaron generation, apparently not related to the exciton diffusion to the polymer/fullerene interface; the second, less significant, is a loss in the exciton population within the photoexcited P3HT domains. The steady‐state photoinduced absorption spectra of degraded samples exhibits the appearance of a signal ascribed to triplet excitons, which is absent for non‐degraded samples. This latter observation is interpreted considering the formation of degraded sites where intersystem crossing and triplet exciton formation is more effective. The photovoltaic characteristics of same blends are also studied and discussed by comparing the decrease in the overall power conversion efficiency of solar cells.
Electrochemical Micromachining as an Enabling Technology for Advanced Silicon Microstructuring
Authors: Bassu Margherita , Surdo Salvatore , Strambini Lucanos Marsilio , Barillaro Giuseppe 
Published: January 2012

AbstractBased on previous theoretical and experimental results on the electrochemical etching of silicon in HF‐based aqueous electrolytes, it is shown for the first time that silicon microstructures of various shapes and silicon microsystems of high complexity can be effectively fabricated in any research lab with sub‐micrometer accuracy and high aspect ratio values (about 100). This is well beyond any up‐to‐date wet or dry microstructuring approach and is achieved using a wet etching, low‐cost technology: silicon electrochemical micromachining (ECM). Dynamic control of the etching anisotropy (from 1 to 0) as the electrochemical etching progresses allows the silicon dissolution to be switched in real‐time from the anisotropic to the isotropic regime and enables advanced silicon microstructuring to be achieved through the use of high‐aspect‐ratio functional and sacrificial structures, the former being functional to the microsystem operation and the latter being sacrificed for accurate microsystem fabrication. World‐wide dissemination of the ECM technology for silicon microstructuring is envisaged in the near future, due to its low cost and high flexibility, with high‐potential impact on, though not limited to, the broad field of microelectronics and microfabrication.
Protein/Polymer‐Based Dual‐Responsive Gold Nanoparticles with pH‐Dependent Thermal Sensitivity
Authors: Strozyk Malte S. , Chanana Munish , Pastoriza‐Santos Isabel , Pérez‐Juste Jorge , Liz‐Marzán Luis M. 
Published: January 2012

AbstractThis article presents the synthesis and physicochemical behavior of dual‐responsive plasmonic nanoparticles with reversible optical properties based on protein‐coated gold nanoparticles grafted with thermosensitive polymer brushes by means of surface‐initiated atom transfer radical polymerization (SI‐ATRP) that exhibit pH‐dependent thermo‐responsive behavior. Spherical gold NPs of two different sizes (15 nm and 60 nm) and with different stabilizing agents (citrate and cetyltrimethylammonium bromide (CTAB), respectively) were first capped with bovine serum albumin (BSA). The resulting BSA‐capped NPs (Au@BSA NPs) exhibited not only extremely high colloidal stability under physiological conditions, but also a reversible U‐shaped pH‐responsive behavior, similar to pure BSA. The ϵ‐amine of the L‐lysine in the protein coating was then used to covalently bind an ATRP‐initiator, allowing for the SI‐ATRP of thermosensitive polymer brushes of oligo(ethylene glycol) methacrylates with an LCST of 42 °C in pure water and around 37 °C under physiological conditions. Such protein coated nanoparticles grafted with thermosensitive polymers exhibit a smart pH‐dependent thermosensitive behavior.
Auf der Suche nach neuen Materialien: Kristallzucht von quaternären und höherwertigen Oxiden in Flussmitteln
Authors: Bugaris Daniel E. , zur Loye Hans‐Conrad 
Published: January 2012

AbstractDieser Aufsatz behandelt die explorative Kristallzucht in Hochtemperaturlösungen als eine Methode zur Entdeckung von komplexen Oxidmaterialien. Er gibt eine Übersicht über das Verfahren der Kristallzucht in der Schmelze (Flux‐ oder Flussmittelzüchtung) und kann als Leitfaden für die Anwendung dieser Technik dienen. Die am häufigsten eingesetzten Schmelzen werden hinsichtlich ihres Lösungsvermögens für spezifische Elemente diskutiert, und typische Reaktionsbedingungen werden zusammengestellt. Um das Leistungsvermögen der Fluxmethode zu demonstrieren, werden verschiedene kürzlich hergestellte quaternäre und höhere Oxide vorgestellt, die für das Züchten von Oxidkristallen aus spezifischen Elementen geeignet sind.
Single, binary and ternary metal adsorption using acid‐treated Aegle marmelos Correa shell: kinetic, mechanistic and thermodynamic study
Authors: Anandkumar J. , Mandal B. 
Published: January 2012

ABSTRACTIn this study, adsorption of metals from aqueous solution using H2SO4‐treated Aegle marmelos Correa shell (AMCS) was carried out in single and multimetal system. The maximum BET surface area (34.28 m2/g) and conspicuous change in the adsorbent surface were achieved when absolute concentration (98%) of acid was used to activate the AMCS. The sorption capacity of Pb2+, Ni2+ and Sr2+ was increased from 21.48 to 81.6 mg/g, 6.37 to 52.89 mg/g and 19.57 to 69.95 mg/g, respectively, as the H2SO4 concentration increased from 24.5% to 98% to activate the AMCS. The maximum adsorption capacities of Pb2+, Ni2+ and Sr2+ were observed at pH 5.2 (82.9 mg/g), 5.8 (54.89 mg/g) and 6.8 (72.95 mg/g), respectively. Presence of other ions significantly reduces the metal uptake when they were present at high concentrations in the metal solution. The equilibrium data fitted satisfactorily with Langmuir model compared with other models. Monolayer sorption capacity was obtained as 122.7, 70.18 and 80.73 mg/g for Pb2+, Ni2+ and Sr2+ at 30 °C, respectively. The effect of binary and ternary metal ions on adsorption capacity was found to be antagonistic behavior. The sorption kinetics was found to follow the pseudo‐second‐order kinetic model. But, the positive values of ΔH° and the increase in metal uptake with increase in solution temperature indicate the endothermic reaction for Ni2+ adsorption. The intermolecular binding (ion–dipole) of Pb2+ and Sr2+ and intermolecular binding coupled with intramolecular binding of Ni2+ were responsible for metal binding with cellulosic and lignin function groups. © 2012 Curtin University of Technology and John Wiley & Sons, Ltd.
Response Surface Methodology, an effective strategy in the optimization of the generation of curcumin‐loaded micelles
Authors: Wei Tan Khang , Manickam Sivakumar 
Published: January 2012

ABSTRACTCurcumin, a yellow pigment extracted from the dried rhizome of Curcuma longa, found to have significant pharmaceutical activities. However, the bioavailability of curcumin after administration is always low because of its extremely poor solubility in water. To improve the absorption rate of curcumin in vivo, curcumin‐loaded micelles have been developed by using GRAS surfactants, namely Brij 56 and Span 20, and by the application of ultrasonic cavitation. To investigate the interaction between different factors and to optimize the formulation conditions, Response Surface Methodology has been adopted. Both Central Composite Design and Box–Behnken Design (BBD) have been attempted in this study, and a better fitted quadric polynomial equation has been obtained from BBD that resulted into the coefficient of determination (R2) of 0.9894 and 0.9574 for the zeta‐average and polydispersity index of the formulation, respectively. In contrast, Analysis of Variance suggested a coefficient of determination (R2) for Central Composite Design plots that is 0.9172 for particle size response surface and 0.8246 for the polydispersity response surface. Optimization based on BBD model suggested 28 possible solutions, for which the generated solution with the highest desirability (0.764) predicted the curcumin‐loaded micelle formulation with 19.99 nm particle size and with 0.267 polydispersity index, when the formulation hydrophilic–lipophilic balance number is 9.46, curcumin‐to‐water weight ratio is 0.7 and surfactant‐to‐water weight ratio is 0.11. The whole investigation clearly supports the potential of ultrasonic cavitation in the generation of curcumin‐loaded micelles. © 2012 Curtin University of Technology and John Wiley & Sons, Ltd.
Present and future climate change in the semi‐arid region of West Africa: a crucial input for practical adaptation in agriculture
Authors: Sarr Benoît 
Published: January 2012

AbstractClimate change trends and projections based on observation and climate models were reviewed in West Africa (WA). Historically, the region has experienced decades of severe drought along with cycles of above average rainfall which have greatly affected agricultural production. Future projections indicate decreased rainfall over the Sahel coastline. Observations already indicate an average increase in temperature of between 0.2 and 0.8 °C; when projected, this increases further to between 3.0 and 4.0 °C. Of greater concern, however, is the late onset, early cessation dates of rainfall and reduction of length of growing period (LGP) which are now locally negatively impacting agriculture in the region. Furthermore, projections indicate a 20% reduction of LGP in 2050. These results represent essential input for accelerating agricultural adaptation to climate change. Copyright © 2012 Royal Meteorological Society
Visualizing and quantifying cell phenotype using soft X‐ray tomography
Authors: McDermott Gerry , Fox Douglas M. , Epperly Lindsay , Wetzler Modi , Barron Annelise E. , Le Gros Mark A. , Larabell Carolyn A. 
Published: January 2012

AbstractSoft X‐ray tomography (SXT) is an imaging technique capable of characterizing and quantifying the structural phenotype of cells. In particular, SXT is used to visualize the internal architecture of fully hydrated, intact eukaryotic and prokaryotic cells at high spatial resolution (50 nm or better). Image contrast in SXT is derived from the biochemical composition of the cell, and obtained without the need to use potentially damaging contrast‐enhancing agents, such as heavy metals. The cells are simply cryopreserved prior to imaging, and are therefore imaged in a near‐native state. As a complement to structural imaging by SXT, the same specimen can now be imaged by correlated cryo‐light microscopy. By combining data from these two modalities specific molecules can be localized directly within the framework of a high‐resolution, three‐dimensional reconstruction of the cell. This combination of data types allows sophisticated analyses to be carried out on the impact of environmental and/or genetic factors on cell phenotypes.
Spectrofluorimetric determination of aliskiren in dosage forms and urine
Authors: Aydoğmuş Zeynep 
Published: January 2012

ABSTRACTA new, simple and sensitive spectrofluorimetric method has been developed for the determination of aliskiren (ALS) in dosage forms and human urine. The method is based on the reaction between ALS and fluorescamine in borate buffer solution, pH 9, to give a highly fluorescent derivative which is measured at 482 nm after excitation at 382 nm. The factors affecting the reaction were carefully studied. The fluorescence intensity concentration plots were rectilinear over the range 140–1400 ng/mL with a limit of detection 13.47 ng/mL and limit of quantitation 40.81 ng/mL. The developed method was successfully applied to the analysis of the drug in tablets and human urine; the average recoveries (n = 6) were 99.88 ± 0.38% and 99.57 ± 0.44%, respectively. The analytical performance of the method was fully validated and the results were satisfactory. The stability of the drug was studied by subjecting it to acidic, basic, oxidative and thermal degradation. Copyright © 2012 John Wiley & Sons, Ltd.
Application of optimized chemiluminescence assay for determination of the antioxidant capacity of herbal extracts
Authors: Pogačnik Lea , Ulrih Nataša Poklar 
Published: January 2012

ABSTRACTA chemiluminescence (CL) assay for the determination of antioxidant capacity (AOC) has been optimized and applied to analyses of herbal extracts in the present study. The optimal concentrations of reagents (luminol, H2O2, horseradish peroxidase) have been determined, as well as the optimal reaction conditions (wavelength, pH, temperature, sample volume). All of the measurements were performed at the emission maximum of the oxidized form of luminol (425 nm). The optimal concentrations of the reagents were determined as follows: 1.6 mmol/L luminol, 7.5 mmol/L H2O2 and 0.14 U/mL horseradish peroxidase activity in the reaction mixture. Analyses were carried out in phosphate buffer, pH 7.4, at room temperature. With the optimized CL assay, the AOCs of various water and methanol herbal extracts were determined (dog rose hips, plantain leaves and coltsfoot and thyme flowers) and the results were compared to those obtained by other classical methods for the evaluation of antioxidants. Strong correlations (r > 0.9) with the Folin–Ciocalteau assay and the 2,2‐diphenyl‐1‐picrylhydrazyl radical (DPPH)● assay are confirmed, although there is no correlation between AOC and the concentration of ascorbic acid in the samples analysed. This optimized CL assay is simple, rapid and reliable, and it represents a good alternative to classical methods (Folin–Ciocalteau, DPPH●) for the determination of AOC of herbal extracts and other food samples. Copyright © 2012 John Wiley & Sons, Ltd.