bluuebunny/crossref_metadata_2025_split huggingface dataset:
Distance to hospital and utilization of surgical services in Haiti: do children, delivering mothers, and patients with emergent surgical conditions experience greater geographical barriers to surgical care?
Authors: Friedman James M. , Hagander Lars , Hughes Christopher D. , Nash Katherine A. , Linden Allison F. , Blossom Jeff , Meara John G. 
Published: August 2012

SUMMARYBackgroundAn inverse relationship between healthcare utilization and distance to care has been previously described. The purpose of this study was to evaluate this effect related to emergency and essential surgical care in central Haiti.MethodsWe conducted a retrospective review of operative logbooks from the Clinique Bon Sauveur in Cange, Haiti, from 2008 to 2010. We used Geographic Information Systems to map the home locations of all patients. Spearman's correlation was used to determine the relationship between surgical utilization and distance, and a multivariate linear regression model identified characteristics associated with differences in distances traveled to care.ResultsThe highest annual surgical utilization rate was 184 operations/100 000 inhabitants. We found a significant inverse correlation between surgical utilization rate and distance from residence to hospital (rs = −0.68, p = 0.02). The median distance from residence to hospital was 55.9 km. Pediatric patients lived 10.1% closer to the hospital than adults (p < 0.01), and distance from residence to hospital was not significantly different between men and women (p = 0.25). Patients who received obstetric or gynecologic surgery originated 7.8% closer to the hospital than patients seeking other operations (p < 0.01), and patients who received emergent surgical care originated 24.8% closer to the hospital than patients who received elective surgery (p < 0.01).ConclusionsUtilization of surgical services was low and inversely related to distance from residence to hospital in rural areas of central Haiti. Children and patients receiving obstetric, gynecologic or emergent surgery lived significantly closer to the hospital, and these groups may need special attention to ensure adequate access to surgical care. Copyright © 2012 John Wiley & Sons, Ltd.
Silver nanoparticle‐induced oxidative stress, genotoxicity and apoptosis in cultured cells and animal tissues
Authors: Kim Soohee , Ryu Doug‐Young 
Published: August 2012

ABSTRACTSilver nanoparticles (AgNPs) have emerged as an important class of nanomaterials for a wide range of industrial and medical applications. However, the unique properties of AgNPs could potentially lead to unexpected hazards to both human health and the well being of the environment. Possible mechanisms of AgNP‐induced toxicity include the stimulation of oxidative stress, genotoxicity and apoptosis. In this study, a number of previous studies are therefore summarized that demonstrate oxidative stress‐, genotoxicity‐ and apoptosis‐related changes brought about by AgNPs in cultured cells and animal tissues. The physicochemical properties of AgNPs that are involved in encouraging such changes are also discussed. Copyright © 2012 John Wiley & Sons, Ltd.
Development of a chronic noncancer oral reference dose and drinking water screening level for sulfolane using benchmark dose modeling
Authors: Thompson Chad M. , Gaylor David W. , Tachovsky J. Andrew , Perry Camarie , Carakostas Michael C. , Haws Laurie C. 
Published: August 2012

ABSTRACTSulfolane is a widely used industrial solvent that is often used for gas treatment (sour gas sweetening; hydrogen sulfide removal from shale and coal processes, etc.), and in the manufacture of polymers and electronics, and may be found in pharmaceuticals as a residual solvent used in the manufacturing processes. Sulfolane is considered a high production volume chemical with worldwide production around 18 000–36 000 tons per year. Given that sulfolane has been detected as a contaminant in groundwater, an important potential route of exposure is tap water ingestion. Because there are currently no federal drinking water standards for sulfolane in the USA, we developed a noncancer oral reference dose (RfD) based on benchmark dose modeling, as well as a tap water screening value that is protective of ingestion. Review of the available literature suggests that sulfolane is not likely to be mutagenic, clastogenic or carcinogenic, or pose reproductive or developmental health risks except perhaps at very high exposure concentrations. RfD values derived using benchmark dose modeling were 0.01–0.04 mg kg−1 per day, although modeling of developmental endpoints resulted in higher values, approximately 0.4 mg kg−1 per day. The lowest, most conservative, RfD of 0.01 mg kg−1 per day was based on reduced white blood cell counts in female rats. This RfD was used to develop a tap water screening level that is protective of ingestion, viz. 365 µg l−1. It is anticipated that these values, along with the hazard identification and dose–response modeling described herein, should be informative for risk assessors and regulators interested in setting health‐protective drinking water guideline values for sulfolane. Copyright © 2012 John Wiley & Sons, Ltd.
A tyrosine kinase inhibitor‐induced myocardial degeneration in rats through off‐target phosphodiesterase inhibition
Authors: Hu Wenyue , Hirakawa Brad , Jessen Bart , Lee Michelle , Aguirre Shirley 
Published: August 2012

ABSTRACTPF‐04254644 is a selective kinase inhibitor of mesenchymal epithelial transition factor/hepatocyte growth factor receptor with known off‐target inhibitory activity against the phosphodiesterase (PDE) family. Rats given repeated oral doses of PF‐04254644 developed a mild to moderate myocardial degeneration accompanied by sustained increase in heart rate and contractility. Investigative studies were conducted to delineate the mechanisms of toxicity. Microarray analysis of Sprague–Dawley rat hearts in a 6 day repeat dose study with PF‐04254644 or milrinone, a selective PDE3 inhibitor, revealed similar perturbation of the cyclic adenosine monophosphate (c‐AMP) pathway. PDE inhibition and activation of c‐AMP were further substantiated using PDE3B immunofluorescence staining and through a c‐AMP response element reporter gene assay. The intracellular calcium and oxidative stress signaling pathways were more perturbed by treatment with PF‐04254644 than milrinone. The rat cardiomyocytes calcium assay found a dose‐dependent increase in intracellular calcium with PF‐04254644 treatment. These data suggest that cardiotoxicity of PF‐04254644 was probably due to activation of c‐AMP signaling, and possibly subsequent disruption of intracellular calcium and oxidative stress signaling pathways. The greater response with PF‐04254644 as compared with milrinone in gene expression and micro‐ and ultrastructural changes is probably due to the broader panel of PDEs inhibition. Copyright © 2012 John Wiley & Sons, Ltd.
In vivo comet assay of multi‐walled carbon nanotubes using lung cells of rats intratracheally instilled
Authors: Ema Makoto , Masumori Shoji , Kobayashi Norihiro , Naya Masato , Endoh Shigehisa , Maru Junko , Hosoi Masayo , Uno Fuyumi , Nakajima Madoka , Hayashi Makoto , Nakanishi Junko 
Published: August 2012

ABSTRACTThe genotoxicity of multi‐walled carbon nanotubes (MWCNTs) was evaluated in vivo with comet assays using the lung cells of rats given MWCNTs. The MWCNTs were intratracheally instilled as a single dose at 0.2 or 1.0 mg kg–1 or a repeated dose at 0.04 or 0.2 mg kg–1, once a week for 5 weeks, to male rats. The rats were sacrificed 3 or 24 h after the single instillation and were sacrificed 3 h after the last instillation in the repeated instillation groups. Histopathological examinations of the lungs revealed that MWCNTs caused inflammatory changes including the infiltration of macrophages and neutrophils after a single instillation and repeated instillation at both doses. In comet assays using rat lung cells, no changes in % Tail DNA were found in any group given MWCNTs. These findings indicate that MWCNTs do not have the potential to cause DNA damage in comet assays using the lung cells of rats given MWCNTs at doses causing inflammatory responses. Copyright © 2012 John Wiley & Sons, Ltd.
Configuration space partitioning and matrix buildup scaling for the vibrational configuration interaction method
Authors: Samsonyuk Andriy , Scheurer Christoph 
Published: August 2012

AbstractThe accurate computation of anharmonic vibrational states for medium to large molecules is a requirement for the detailed understanding of nonlinear multidimensional infrared spectra and the dynamical information encoded in them. The vibrational configuration interaction (VCI) method constitutes a particularly promising tool in this respect. It is generally hampered though by its unfavorable scaling with respect to system size. We analyze the scaling behavior of several well‐known as well as some new approximate VCI schemes in detail, which are complementary to the class of configuration selection schemes developed recently. We find that the combination of a configuration space partitioning, possibly based on configuration selection, with energetic thresholding and resonance screening provides an efficient scheme for the reduction of computational effort involved in VCI calculations while at the same time maintaining sufficient accuracy for the vibrational energies. © 2012 Wiley Periodicals, Inc.
Macromonomers as Well‐Defined Building Blocks in the Synthesis of Hybrid Octafunctional Star‐Shaped Poly(ethylene oxide)s
Authors: Pozza Gladys M.‐E. , Harris Hassan , Barthel Markus J. , Vitz Jürgen , Schubert Ulrich S. , Lutz Pierre J. 
Published: August 2012

AbstractThe present work addresses the synthesis and the molecular and structural characterization of soluble macromolecular architectures based on functional poly(ethylene oxide) (PEO)s and octafunctional silsesquioxanes. The synthesis of a series of functional PEOs by deactivation, decorated with allyl groups at one chain‐end, was considered first. PEO star‐shaped polymers were prepared by coupling via hydrosilylation of ω‐allyl PEOs with octakis(hydridodimethylsiloxy)octasilsesquioxane (HMe2SiOSiO1.5)8 (Q8M8H), in the presence of a “Speier” catalyst. The products were characterized by SEC, 1H NMR spectroscopy, light scattering, and MALDI–TOF MS to determine the molar masses and degree of functionalization. The star‐shaped PEOs (Q8M8PEO) could be isolated from the raw reaction product and characterized. A functionalization close to the theoretical value was obtained.
pH‐Responsive Double‐Hydrophilic Block Copolymers: Synthesis and Drug Delivery Application
Authors: Dai Xiao‐Hui , Hong Chun‐Yan , Pan Cai‐Yuan 
Published: August 2012

AbstractA novel double‐hydrophilic block copolymer P(MEO2MA‐co‐OEGMA)‐b‐PAMA has been successfully synthesized by two‐step RAFT polymerization. Then, the amino groups of PAMA blocks in the copolymers react with 1‐pyrenecarboxaldehyde via a “Schiff‐base” reaction, and the resulting copolymers are self‐assembled to form spherical micelles in aqueous solution. Because the “Schiff‐base” linkage is pH sensitive, the release rate of pyrene depends upon the pH of solution. Complete release is achieved at pH 1, and the control release is much faster at pH 5.5 than that at pH 7.4. With progress of pyrene release, the micelles are disassembled gradually and disappeared completely at last. This double‐hydrophilic copolymer is a promising candidate of drug carrier for the aldehyde‐ containing hydrophobic drugs.
Plant Oil‐Based Long‐Chain C26 Monomers and Their Polymers
Authors: Vilela Carla , Silvestre Armando J. D. , Meier Michael A. R. 
Published: August 2012

AbstractThe self‐metathesis of erucic acid with ruthenium‐based catalysts, followed by the hydrogenation of the double bond, yielded 1,26‐hexacosanedioic acid (AA). Polycondensation of this biobased long‐chain α,ω‐dicarboxylic acid with hexacosane‐1,26‐diol (BB), generated from the former by reduction, yielded the polyester 26,26. Monomer AA was also polymerized with short‐chain alkanediols, namely dodecane‐1,12‐diol and butane‐1,4‐diol, generating polyesters 12,26 and 4,26, respectively. The properties of these aliphatic polyesters were investigated by various techniques, revealing high crystallinity, melting, and degradation temperatures, depending on the monomers used. These materials are an attractive alternative to fossil resource‐based polymeric materials.
Recent Progress in the Development of New Acetylenic Polymers
Authors: Hu Rongrong , Lam Jacky Wing Yip , Tang Ben Zhong 
Published: August 2012

AbstractAcetylenic polymers are a group of specialty materials with novel properties. In this paper, recent progress in the development of functional acetylenic polymers is summarized. These polymers are synthesized through different polymerization approaches such as Sonogashira polycoupling, decarbonylative chloroarylation polyaddition, and polycyclotrimerization. Efforts in the development of new monomers and catalyst exploration as well as reaction optimization have lead to a large quantity of linear and hyperbranched polymers with high molecular weights and good processability. The polymer functionalization is realized by incorporating functional units into the monomer structures, which endow the resulting polymers with fascinating properties such as aggregation‐induced emission, optical nonlinearity, light refractivity, photosensitivity, photopatternability, redoxactivity, and magnetism.
Suboptimal robust linear visual servoing for a delayed underactuated system
Authors: Benitez‐Morales A. , Santos Omar , Romero Hugo , Ramos‐Velasco Luis Enrique 
Published: August 2012

SUMMARYIn this contribution, a suboptimal robust control law for a specific class of underactuated delayed system is synthesized. The control strategy based on very well‐known results for delay‐dependent stability considers the time delay involved in the dynamical system, which affects to control signal. This contribution illustrates how the theoretical results can be used to improve the real‐time performance of the closed‐loop system considered. The delay is introduced into the control system by the vision module, due to the time required to perform the image treatment. In order to show the good performance of the control law proposed, real‐time experiments are developed by applying a visual servoing technique on the cart‐inverted pendulum system. Obtained results also illustrate how the conservativeness of theoretical results affects the performance of the closed‐loop system and the negative effects of delays in the control loop. Furthermore, a robust stability analysis is done to establish the robustness of control law with respect to the amount of delay presented in the system.Copyright © 2012 John Wiley & Sons, Ltd.
Preparative Isolation and Purification of Three Stilbene Glycosides from the Tibetan Medicinal Plant Rheum tanguticum Maxim. Ex Balf. by High‐speed Counter‐current Chromatography
Authors: Zhao Xiao‐Hui , Han Fa , Li Yu‐Lin , Yue Hui‐Lan 
Published: August 2012

ABSTRACTIntroductionStilbene glycosides are the primary constituents of Rheum tanguticum Maxim. ex Balf., to which different bioactivities has been attributed, including: anti‐HIV, anti‐oxidant, anti‐tumour, anti‐malarial, and anti‐allergy activity. However, effective methods for the isolation and purification of stilbene glycosides, such as trans‐rhapontin, cis‐rhapontin and trans‐desoxyrhaponticin, from this herb are not currently available.ObjectiveTo develop an efficient method for the preparative isolation and purification of three stilbene glycosides from Rheum tanguticum Maxim. ex Balf. via high‐speed counter‐current chromatography (HSCCC).MethodsA solvent system composed of chloroform:n‐butanol:methanol:water (4:1:3:2, v/v/v/v) was developed for the separation. The upper phase was used as the stationary phase, and the lower phase was used as the mobile phase. The flow rate was 1.8 mL/min. The apparatus was controlled at 800 rpm and 25 °C, and the effluent was monitored at 280 nm. Chemical constituents were analysed by high‐performance liquid chromatography (HPLC), and their structures were identified by 1 H‐ and 13C‐NMR.ResultsUnder the optimised conditions, 25.5 mg trans‐rhapontin, 16.0 mg cis‐rhapontin and 20.5 mg trans‐desoxyrhaponticin were separated from 80 mg crude sample; the isolates had purities of 99.6, 97.2 and 99.2%, respectively.ConclusionA simple and efficient HSCCC method has been optimised for the preparative separation of stilbene glycosides from Rheum tanguticum Maxim. ex Balf. Copyright © 2012 John Wiley & Sons, Ltd.
Measurement of distress in Chinese inpatients with lymphoma
Authors: Wang Yisi , Zou Liqun , Jiang Ming , Wei Yuquan , Jiang Yu 
Published: August 2012

AbstractPurposeThe aim of this study was to assess the levels and sources of distress in patients with lymphoma. This study also focused on the influence of factors of the level of distress and the cutoff score using the Distress Thermometer (DT) relative to the Hospital Anxiety and Depression Scale (HADS).MethodDT and HADS were used to estimate the psychological status of 323 eligible lymphoma patients. The DT was evaluated against the HADS for its sensitivity and specificity.ResultsOne hundred and ninety‐three (59.7%) lymphoma patients experienced overall distress on the HADS, with 137 (42.4%) experiencing anxiety and 114 (35.3%) suffering from depression. There were 199 (61.6%) and 163 (50.5%) patients with distress score ≥4 and ≥5, respectively. DT was significantly correlated with the HADS‐total (T) (r = 0.820, p < 0.001), HADS‐depression (D) (r = 0.763, p < 0.001), and HADS‐anxiety (A) (r = 0.738, p < 0.001). The consistency of the DT and HADS was favorable (coherence index = 0.6030, p < 0.01) when the cutoff score was 5 for the DT. Referring to the cutoff of 15 on HADS, 5 on DT yielded optimal specificity (0.869, p < 0.001) and sensitivity (0.756, p < 0.001). In multiple logistic regression analysis, patients with ‘B symptoms’ were more likely to have a distress score ≥5 [OR = 4.512, p < 0.05, 95% CI 1.953–10.467].ConclusionDT is efficacious for screening for anxiety and depression in lymphoma patients. Copyright © 2012 John Wiley & Sons, Ltd.
Diamond as a nanomedical agent for versatile applications in drug delivery, imaging, and sensing
Authors: Man Han B. , Ho Dean 
Published: August 2012

AbstractA spectrum of materials has been explored as potential platforms for nanomedicine in the areas of drug delivery, imaging, and diagnostics/sensing. Depending upon the application required, the therapeutic compound being delivered, or the imaging agent being modified, certain nanoparticulate materials offer specific advantages that may uniquely enhance efficiency. Among the classes of particles being investigated, diamond‐based platforms have emerged as promising vehicles for drug delivery and imaging following several recent studies that demonstrate their ability to enhance therapeutic efficacy, particularly for anthracyclines, mediate markedly improved magnetic resonance imaging contrast and photostable fluorescence, possess scalable processing parameters, and exhibit biocompatibility, among many other important attributes. More specifically, detonation NDs have faceted surfaces that can mediate potent interactions with surrounding water molecules or therapeutic compounds. This attribute can mitigate premature drug release to prevent major side effects such as myelosuppression, while water molecule recruitment can increase the relaxivity of covalently conjugated gadolinium. These properties of NDs and diamond‐based devices will be discussed in this article, with a focus on therapeutic delivery in addition to insight on their use in imaging, devices, implants/coatings, and biocompatibility. Key areas of potential, where advances in biology and medicine can be realized through the continued development of this platform as well as requisite future studies, will also be highlighted.
From porous to dense thin ZnO films through reactive DC sputter deposition onto Si (100) substrates
Authors: Borysiewicz Michał A. , Dynowska Elżbieta , Kolkovsky Valery , Dyczewski Jan , Wielgus Maciej , Kamińska Eliana , Piotrowska Anna 
Published: August 2012

AbstractThin polycrystalline ZnO films are deposited onto Si (100) substrates by means of DC reactive sputter deposition from a Zn target in an argon–oxygen mixture. The influences of the oxygen content in the mixture and of the total gas pressure in the reactor during deposition as well as of applying postgrowth annealing in an oxygen flow at elevated temperatures on the structural, chemical, and electrical properties of the obtained films are discussed. Three types of thin‐film structures were obtained: a porous polycrystalline Zn layer, a porous polycrystalline ZnO layer and a dense ZnO film. The porous Zn layer grew at oxygen content less than 33% and upon annealing in an oxygen flow at 400, 600, and 800 °C transformed to porous polycrystalline ZnO films. For oxygen contents ≥33% the obtained films were dense and polycrystalline with a 00.2 dominating orientation. X‐ray diffraction (XRD), scanning electron microscopy (SEM), Rutherford backscattering spectroscopy (RBS), and Hall effect measurements were applied to characterize the obtained films.
Drift mobility of thermalized and highly energetic holes in thin layers of amorphous dielectric SiC
Authors: Sielski Jan , Jeszka Jeremiasz K. 
Published: August 2012

AbstractThe development of new technology in the electronics industry requires new dielectric materials. It is also important to understand the charge‐carrier transport mechanism in these materials. We examined the hole drift mobility in amorphous SiC dielectric thin films using the time‐of‐flight (TOF) method. Charge carriers were generated using an electron gun. The generated holes gave a dispersive TOF signal and the mobility was low. For electric field strengths above 4 × 105 V cm−1 the drift mobility shows a very strong dependence on the electric field and a weak temperature dependence (transport of “high‐energy” charge carriers). At lower electric fields and for thermalized charge carriers the mobility is practically field independent and thermally activated. The observed phenomenon was attributed to the changes in the effective energy of the generated carriers moving in the high electric fields and consequently in the density of localized states taking part in the transport.
Optical switching patterns using electrospun nanofiber array
Authors: Kim Bumjoo , Cho Seong J. , An Taechang , Ryu Hyobong , Lim Hoon , Lim Geunbae 
Published: August 2012

AbstractThis is a report on optical switching patterns textured by electrospun nanofibers according to the direction of the incident light. The effect of fiber size is also explained. Depending on the direction of the incident light, there should be two distinct reflective behaviors on the surfaces of the nanofibers: diffuse and specular reflections. The mechanism for this critical phenomenon is explained in terms of the cylindrical geometry of the fiber surface, and the “on–off” reflective behavior can be maximized when the diameters of the fibers are quite small, such as nanofibers.magnified imageSwitching the patterns of a nanofiber array according to the direction of light: north and east, respectively (scale bar = 1 mm).(© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)