bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preservation of GHRH and GH-releasing peptide-2 efficacy in young men with experimentally induced hypogonadism
Authors: Veldhuis Johannes D , Keenan Daniel M , Bailey Joy N , Miles John M , Bowers Cyril Y 
Published: May 2009

BackgroundSomatostatin (SS), GHRH, GH-releasing peptide (GHRP), and the sex-steroid milieu regulate GH secretion.ObjectiveTo test whether GHRH and GHRP remain effective secretagogs in the face of short-term hypogonadism.DesignProspective, randomized double-blind.MethodsHealthy young men (n=24) received a GnRH agonist twice 3 weeks apart followed by placebo (n=13, Pl) or testosterone (n=11, testosterone) addback. Subjects were then given consecutive i.v. infusions of l-arginine (to restrain SS outflow) and a maximally effective dose of GHRH or GHRP-2 (to test corresponding secretagog pathways).ResultsGH secretion stimulated by l-arginine/GHRH and by l-arginine/GHRP-2 was unaffected by combined testosterone/estradiol (E2) depletion. The low testosterone/E2 milieu decreased basal (nonpulsatile) GH secretion (P=0.038), without altering fasting pulsatile GH secretion or IGF1 or IGF-binding protein (IGFBP)-3 concentrations. IGFBP-1 (P<0.0001) and abdominal visceral fat (AVF, P=0.017) correlated negatively with fasting basal GH secretion. By contrast, IGF1 (P=0.0012) and IGFBP-3 (P=0.015) correlated positively with fasting pulsatile GH secretion. AVF (P=0.0024) was a negative determinant, and IGF1 a positive determinant (P=0.018), of GHRH-driven GH pulses. Responses to GHRP-2 were unrelated to any of these factors.Conclusionl-arginine/GHRP-2 appears to be an especially robust stimulus of GH secretion, since efficacy is unmodified by profound short-term hypogonadism, a range of AVF estimates, and a spectrum of IGF1, IGFBP-1, and IGFBP-3 concentrations. Whether robustness also applies to chronic hypogonadism is not known.
Selenium bioaccumulation and body condition in shorebirds and terns breeding in San Francisco Bay, California, USA
Authors: Ackerman Joshua T. , Eagles-Smith Collin A. 
Published: May 2009

Abstract
The present study evaluated Se bioaccumulation in four waterbird species (n = 206 birds) that breed within San Francisco Bay, California, USA: American avocets (Recurvirostra americana), black-necked stilts (Himantopus mexicanus), Forster's terns (Sterna forsteri), and Caspian terns (Hydroprogne caspia). Selenium concentrations were variable and influenced by several factors, including species, region, reproductive stage, age, and sex. Adult Se concentrations (μg/g dry wt) in livers ranged from 3.07 to 48.70 in avocets (geometric mean ± standard error, 7.92 ± 0.64), 2.28 to 41.10 in stilts (5.29 ± 0.38), 3.73 to 14.50 in Forster's terns (7.13 ± 0.38), and 4.77 to 14.40 in Caspian terns (6.73 ± 0.78). Avocets had higher Se concentrations in the North Bay compared to the South Bay, whereas stilt Se concentrations were similar between these regions and Forster's terns had lower Se concentrations in the North Bay compared to the South Bay. Female avocets had higher Se concentrations than male avocets, but this was not the case for stilts and Forster's terns. Of the factors assessed, reproductive stage had the most consistent effect among species. Prebreeding birds tended to have higher liver Se concentrations than breeding birds, but this trend was statistically significant only for Forster's terns. Forster's tern chicks had lower Se concentrations than Forster's tern adults, whereas avocet and stilt adults and chicks were similar. Additionally, body condition was negatively related to liver Se concentrations in Forster's tern adults but not in avocet, stilt, or Caspian tern adults and chicks. These variable results illustrate the complexity of Se bioaccumulation and highlight the need to sample multiple species and examine several factors to assess the impact of Se on wildlife.
The Role of Theory in Increasing Adherence to Prescribed Practice
Authors: Sirur Ruth , Richardson Julie , Wishart Laurie , Hanna Steven 
Published: May 2009

Purpose: The purpose of this article is to apply theoretical frameworks to adherence behaviour and to guide the development of an intervention to increase adherence to prescribed home programmes. Summary of Key Points: Delivering an effective intervention requires establishing one that is evidence based and of adequate dosage. Two-thirds of patients who receive home exercise prescriptions do not adhere to their home programme, which may contribute to their physiotherapy's being ineffective. The mediating concepts of self-efficacy (SE) and outcome expectations (OE) are common to the five relevant theories used to explain adherence to exercise: the health belief model, protection motivation theory, theory of reasoned action, theory of planned behaviour, and social cognitive theory. Conclusion/Recommendations: Few intervention studies with any theoretical underpinning have examined adherence to exercise. Even fewer have been designed to affect and measure change in the theoretical mediators of SE and OE in patient populations. Physiotherapists must consider increasing adherence as a component of effective physiotherapy. Ongoing research is needed to increase our understanding of adherence to prescribed home programmes and to design interventions to affect theoretical mediators for increasing adherence.
Conductive Core–Sheath Nanofibers and Their Potential Application in Neural Tissue Engineering
Authors: Xie Jingwei , MacEwan Matthew R. , Willerth Stephanie M. , Li Xiaoran , Moran Daniel W. , Sakiyama‐Elbert Shelly E. , Xia Younan 
Published: May 2009

AbstractConductive core–sheath nanofibers are prepared by a combination of electrospinning and aqueous polymerization. Specifically, nanofibers electrospun from poly(ε‐caprolactone) (PCL) and poly(L‐lactide) (PLA) are employed as templates to generate uniform sheaths of polypyrrole (PPy) by in‐situ polymerization. These conductive core–sheath nanofibers offer a unique system to study the synergistic effect of different cues on neurite outgrowth in vitro. It is found that explanted dorsal root ganglia (DRG) adhere well to the conductive core–sheath nanofibers and generate neurites across the surface when there is a nerve growth factor in the medium. Furthermore, the neurites can be oriented along one direction and enhanced by 82% in terms of maximum length when uniaxially aligned conductive core–sheath nanofibers are compared with their random counterparts. Electrical stimulation, when applied through the mats of conductive core–sheath nanofibers, is found to further increase the maximum length of neurites for random and aligned samples by 83% and 47%, respectively, relative to the controls without electrical stimulation. Together these results suggest the potential use of the conductive core–sheath nanofibers as scaffolds in applications such as neural tissue engineering.
Electroluminescence and Laser Emission of Soluble Pure Red Fluorescent Molecular Glasses Based on Dithienylbenzothiadiazole
Authors: Huang Ju , Liu Quan , Zou Jian‐Hua , Zhu Xu‐Hui , Li Ai‐Yuan , Li Jun‐Wen , Wu Sha , Peng Junbiao , Cao Yong , Xia Ruidong , Bradley Donal D. C. , Roncali Jean 
Published: May 2009

AbstractSoluble molecular red emitters 1a/1b are synthesized by Stille coupling from 2‐(3,5‐di(1‐naphthyl)phenyl)thiophene precursors. The compounds show emission maxima at ca. 610 nm in CH2Cl2 solution and 620 nm in solid films. Replacing the n‐hexyl substituent by 4‐sec‐butoxyphenyl produces a marked increase of glass transition temperature (Tg) from 82 °C to 137 °C and increases the solubility in toluene and p‐xylene, thus improving the film‐forming properties. Cyclic voltammetry shows that the compounds can be reversibly oxidized and reduced around +1.10 and −1.20 V, respectively. A two‐layered electroluminescent device based on 1b produces a pure red light emission with CIE coordinates (0.646, 0.350) and a maximal luminous efficiency of 2.1 cd A−1. Furthermore, when used as a solution‐processed red emitter in optically pumped laser devices, compound 1b successfully produces a lasing emission at ca. 650 nm.
Structure and properties of polypropylene‐wrapped carbon nanotubes composite
Authors: Li Wen‐Hua , Chen Xiao‐Hua , Yang Zhi , Xu Long‐Shan 
Published: May 2009

AbstractBy means of in situ graft method, polypropylene (PP)‐wrapped carbon nanotubes (CNTs) composite were prepared. Infrared spectroscopy (IR) results showed that there was covalent linkage between PP and CNTs via maleic anhydride (MAH) grafting. Owing to the uniform dispersion of CNTs and covalent adhesion between PP and CNTs, the tensile strength of PP‐wrapped CNTs composite was higher than that for neat PP by 110%, and a 74% increase as compared to the CNTs/PP (with the same CNTs content) composite. The further test showed a strong mechanical behavior with up to 113% increase in Young's modulus of the neat PP. Based on the uniform dispersion of CNTs, the electrical conductivity of PP‐wrapped CNTs composite increased sharply by up to seven orders of magnitude with 4 wt % CNT fillers. As a result, the volume resistivity was decreased with increase in the CNT content that could be governed in a percolation‐like power law with a relatively low percolation threshold. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Fracture behaviors of metallocene catalyzed polyethylene elastomer via peroxide crosslinking
Authors: Lai S.‐M. , Liu J.‐L. , Hu S.‐H. , Huang C.‐H. , Wang S.‐J. , Chien S.‐C. 
Published: May 2009

AbstractPeroxide cured metallocene catalyzed polyethylene (mPE) has been prepared to form an elastomer. mPEs with two different levels of comonomer contents have been cured with various amounts of dicumyl peroxide. “Threshold” fracture energy is roughly proportional to the reciprocal square root of Young's modulus. The values of tear strength are generally two orders of magnitude larger than the results from cutting measurements. The cutting strength of mPE vulcanizates gives an intermediate value compared with crystalline plastics and conventional elastomers and is comparable with other evaluations of cutting strength for different crosslinking types of mPE and different types of materials, which further signifies the importance of crystalline yielding even in the nanofracture zone of deformation. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Highly thermally stable novolac derivatives and their properties in epoxy composites
Authors: Wu Hsin Ho , Chu Peter P. 
Published: May 2009

AbstractTwo diazo‐coupling novolac derivative resins (carbonyl phenyl azo novolac resin and carbonyl phenol–biphenylene azo novolac resin) were used as flame retardants. The cured resins exhibited elevated glass‐transition temperatures from 115°C (blank) to 195 and 167°C, respectively. The char yield at 800°C was increased, which elaborated the effectiveness of flame retardancy with evaluated limiting oxygen indices around 36 to 40. This was mainly attributed to the increased crosslink densities and highly aromatic contents in the modified phenol novolac derivative resins, which exhibited higher thermal degradation energies. Furthermore, the more effective flame retardancy was expected because of the loss of nitrogen during combustion. Through the evaluation of the cooperative flame retardancy in the organic/inorganic hybrid with char yield and increasing limiting oxygen index percentage, the effects of the filler showed cooperative flame retardancy only with the appropriate addition and with a difference in the crosslinking densities. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Injectable and thermosensitive poly(organophosphazene) hydrogels for a 5‐fluorouracil delivery
Authors: Lee Sun Mi , Chun Chang Ju , Heo Jeong Yun , Song Soo‐Chang 
Published: May 2009

AbstractThe drug solubility and its release profiles of an anticancer drug from an injectable thermosensitive poly(organophosphazene) hydrogel bearing hydrophobic L‐isoleucine ethyl ester and hydrophilic α‐amino‐ω‐methoxy‐poly(ethylene glycol) with and without hydrolysis‐sensitive glycyl lactate ethyl ester or functional glycyl glycine have been investigated. 5‐Fluorouracil (5‐FU) was used as a model anticancer drug. The aqueous solutions of 5‐FU incorporated poly(organophosphazenes) were an injectable fluid state at room temperature and formed a transparent gel at body temperature. The poly(organophosphazene) solution could enhance the solubility of 5‐FU and its solubility (34.26 mg/mL) was increased up to 10‐fold compared to that in phosphate‐buffered saline (3.39 mg/mL, pH 7.4, 4°C). The in vitro drug release profiles from poly(organophosphazene) hydrogels were established in phosphate‐buffered saline at pH 7.4 at 37°C and the release of 5‐FU was significantly affected by the diffusion‐controlled stage. The results suggest that the injectable and thermosensitive poly(organophosphazene) hydrogel is a potential carrier for 5‐FU to increase its solubility, control a relatively sustained and localized release at target sites and thus decrease systemic side effects. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Concentration profile of glass fiber bundles in epoxy‐based gradient composites during centrifugation
Authors: Hashmi S. A. R. , Dwivedi U. K. , Chand Navin 
Published: May 2009

AbstractThe short fiber bundles separated from the machining waste of a printed circuit board (PCB) manufacturing plant were used in preparing functionally graded composites using polysulfide‐modified epoxy resin. The graded material was developed using centrifugation technique. The centrifugation time was varied to obtain different gradient profiles. The concentration profile was then compared with the theoretical HD model (Hashmi‐Dwivedi model), which was modified to accommodate the changes in the shape of suspending particles. A shape factor was introduced in terminal velocity estimation. The simulated results are in agreement with the experimental trends. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Architectonic Subdivisions of Neocortex in the Tree Shrew (Tupaia belangeri)
Authors: Wong Peiyan , Kaas Jon H. 
Published: May 2009

AbstractTree shrews are small mammals that bear some semblance to squirrels, but are actually close relatives of primates. Thus, they have been extensively studied as a model for the early stages of primate evolution. In this study, subdivisions of cortex were reconstructed from brain sections cut in the coronal, sagittal, or horizontal planes, and processed for parvalbumin, SMI‐32‐immunopositive neurofilament protein epitopes, vesicle glutamate transporter 2 (VGluT2), free ionic zinc, myelin, cytochrome oxidase, and Nissl substance. These different procedures revealed similar boundaries between areas, suggesting the detection of functionally relevant borders and allowed a more precise demarcation of cortical areal boundaries. Primary cortical areas were most clearly revealed by the zinc stain, because of the poor staining of layer 4, as thalamocortical terminations lack free ionic zinc. Area 17 (V1) was especially prominent, as the broad layer 4 was nearly free of zinc stain. However, this feature was less pronounced in primary auditory and somatosensory cortex. In primary sensory areas, thalamocortical terminations in layer 4 densely express VGluT2. Auditory cortex consists of two architectonically distinct subdivisions, a primary core region (Ac), surrounded by a belt region (Ab) that had a slightly less developed koniocellular appearance. Primary motor cortex (M1) was identified by the absence of VGluT2 staining in the poorly developed granular layer 4 and the presence of SMI‐32‐labeled pyramidal cells in layers 3 and 5. The presence of well‐differentiated cortical areas in tree shrews indicates their usefulness in studies of cortical organization and function. Anat Rec, 2009. © 2009 Wiley‐Liss, Inc.
Probing the Initial Stages of Molecular Organization of Oligo(p‐phenylenevinylene) Assemblies with Monolayer Protected Gold Nanoparticles
Authors: Kumar Vattakattu R. Rajeev , Sajini Vadukumpulli , Sreeprasad Theruvakkattil S. , Praveen Vakayil K. , Ajayaghosh Ayyappanpillai , Pradeep Thalappil 
Published: May 2009

AbstractTapes, fibrils, and fibers: Thiol‐protected gold nanoparticles have been used to probe the initial stages of the molecular organization of oligo(p‐phenylenevinylene) gelators. The oligo(p‐phenylenevinylene) molecules self‐assemble to form tapes. Further self‐assembly leads to the formation of fibrils, which in turn self‐assemble to form fibers. The existence of these forms has been confirmed by nanoparticle marking.magnified imageThiol‐protected gold nanoparticles (GNPs) have been used to probe the initial stages of the molecular organization of oligo(p‐phenylenevinylene) (OPV) gelators. The hybrid materials prepared by the self‐assembly of OPVs and GNPs are characterized by optical microscopy, fluorescence microscopy, scanning electron microscopy, transmission electron microscopy, and atomic force microscopy. GNPs are located preferentially on the sides of the OPV structures, which implies the presence of alkyl chains at the edges, which makes the assemblies hydrophobic. TEM analyses at the early stages of self‐assembly show tapes that have a width of 4 nm, which upon further self‐assembly, form fibrils through hydrogen bonding. The experiment was performed with GNPs protected with dodecane and octadecane thiols. The existence of tapes, ribbons, fibrils, and fibers were confirmed by nanoparticle marking. Based on the experimental data, we have proposed a hierarchical model for the self‐assembly of OPV molecules. The presence of nanoparticles does not alter the morphology or electronic properties of the OPV structures, as revealed by microscopic and spectroscopic studies.
Robust optimization for multiple responses using response surface methodology
Authors: He Zhen , Wang Jing , Oh Jinho , Park Sung H. 
Published: May 2009

AbstractTypically in the analysis of industrial data for product/process optimization, there are many response variables that are under investigation at the same time. Robustness is also an important concept in industrial optimization. Here, robustness means that the responses are not sensitive to the small changes of the input variables. However, most of the recent work in industrial optimization has not dealt with robustness, and most practitioners follow up optimization calculations without consideration for robustness. This paper presents a strategy for dealing with robustness and optimization simultaneously for multiple responses. In this paper, we propose a robustness desirability function distinguished from the optimization desirability function and also propose an overall desirability function approach, which makes balance between robustness and optimization for multiple response problems. Simplex search method is used to search for the most robust optimal point in the feasible operating region. Finally, the proposed strategy is illustrated with an example from the literature. Copyright © 2009 John Wiley & Sons, Ltd.
A multipurpose capacitive biosensor for assay and quality control of human immunoglobulin G
Authors: Labib Mahmoud , Hedström Martin , Amin Magdy , Mattiasson Bo 
Published: May 2009

AbstractWe report a flow‐injection biosensor system with a capacitive transducer for assay and quality control of human immunoglobulin G (hIgG). The sensing platform is based on self‐assembled monolayers (SAMs) of carboxylic acid terminated alkyl‐thiols with covalently attached concanavalin A. The electrochemical characteristics of the sensor surface were assessed by cyclic voltammetry using a permeable redox couple (potassium ferricyanide). The developed biosensor proved capable of performing a sensitive label‐free assay of hIgG with a detection limit of 1.0 µg mL−1. The capacitance response depended linearly on hIgG concentration over the range from 5.0 to 100 µg mL−1, in a logarithmic plot. Typical measurements were performed in 15 min and up to 18 successive assays were achieved without significant loss of sensitivity using a single electrode. In addition, the biosensor can detect hIgG aggregates with concentrations as low as 0.01% of the total hIgG content (5.0 µg mL−1). Hence, it represents a potential post‐size‐exclusion chromatography–UV (post‐SEC–UV) binding assay for in‐process quality control of hIgG, which cannot be detected by SEC–UV singly at concentrations below 0.3% of the total hIgG content. Biotechnol. Bioeng. 2009; 104: 312–320 © 2009 Wiley Periodicals, Inc.
Induction of mammalian cell death by simple shear and extensional flows
Authors: Tanzeglock Timm , Soos Miroslav , Stephanopoulos Gregory , Morbidelli Massimo 
Published: May 2009

AbstractIn this work we investigated whether the type of shear flow, to which cells are exposed, influences the initiation of cell death. It is shown that mammalian cells, indeed, distinguish between discrete types of flow and respond differently. Two flow devices were employed to impose accurate hydrodynamic flow fields: uniform steady simple shear flow and oscillating extensional flow. To distinguish between necrotic and apoptotic cell death, fluorescence activated cell sorting and the release of DNA in the culture supernatant was used. Results show that Chinese Hamster Ovaries and Human Embryonic Kidney cells will enter the apoptotic pathway when subjected to low levels of hydrodynamic stress (around 2.0 Pa) in oscillating, extensional flow. In contrast, necrotic death prevails when the cells are exposed to hydrodynamic stresses around 1.0 Pa in simple shear flow or around 500 Pa in extensional flow. These threshold values at which cells enter the respective death pathway should be avoided when culturing cells for recombinant protein production to enhance culture longevity and productivity. Biotechnol. Bioeng. 2009; 104: 360–370 © 2009 Wiley Periodicals, Inc.
The generation of stable, high MAb expressing CHO cell lines based on the artificial chromosome expression (ACE) technology
Authors: Kennard Malcolm L. , Goosney Danika L. , Monteith Diane , Zhang Lin , Moffat Mark , Fischer David , Mott John 
Published: May 2009

AbstractThe manufacture of recombinant proteins at industrially relevant levels requires technologies that can engineer stable, high expressing cell lines rapidly, reproducibly and with relative ease. Commonly used methods incorporate transfection of mammalian cell lines with plasmid DNA containing the gene of interest. Identifying stable high expressing transfectants is normally laborious and time consuming. To improve this process, the ACE System has been developed based on pre‐engineered artificial chromosomes with multiple recombination acceptor sites. This system allows for the targeted transfection of single or multiple genes and eliminates the need for random integration into native host chromosomes. To illustrate the utility of the ACE System in generating stable, high expressing cell lines, CHO based candidate cell lines were generated to express a human monoclonal IgG1 antibody. Candidate cell lines were generated in under 6 months and expressed over 1 g/L and with specific productivities of up to 45 pg/cell/day under non‐fed, non‐optimized shake flask conditions. These candidate cell lines were shown to have stable expression of the monoclonal antibody for up to 70 days of continuous culture. The results of this study demonstrate that clonal, stable monoclonal antibody expressing CHO based cell lines can be generated by the ACE System rapidly and perform competitively with those cell lines generated by existing technologies. The ACE System, therefore, provides an attractive and practical alternative to conventional methods of cell line generation. Biotechnol. Bioeng. 2009; 104: 540–553 © 2009 Wiley Periodicals, Inc.