bluuebunny/crossref_metadata_2025 huggingface dataset:
A measurement‐based study on user management in private BitTorrent communities
Authors: Jiang Honglei , Jin Hai , Guo Song , Liao Xiaofei
Published: July 2012

Beyond the traditional BitTorrent, a new genre of peer‐to‐peer communications protocol for worldwide file sharing is rapidly evolving towards private BitTorrent (PT). In recent years, a proliferation of PT communities have emerged. To enhance the user experience, account‐based share‐ratio enforcement (SRE) has been developed and widely adopted. Whereas existing studies mainly take SRE as an incentive, we discover that it also plays a critical role in selecting and filtering users. In addition to SRE, a rich set of user management rules, such as registration management, banning policies, and user caste system, are also studied in this paper. This includes to explore their effects on user behavior, download performance, content availability, and system scalability. The measurement results presented in this paper are based on large‐scale experiments conducted over six representative PT sites for over a year. We find that the stricter registration will lead to fewer new users, resulting in a scalability problem, which is critical for the PT communities because the download performance and content availability depend on not only the contribution of users but also the population of the community. Our measurement and analysis pose a direction for the design of new incentive mechanisms that take the difficulty of enrollment into the consideration.Copyright © 2012 John Wiley & Sons, Ltd.
Modified 6‐Aza Uridines: Highly Emissive pH‐Sensitive Fluorescent Nucleosides
Authors: Sinkeldam Renatus W. , Hopkins Patrycja A. , Tor Yitzhak
Published: July 2012

Optimized facile syntheses and highly desirable spectroscopic properties of two isomorphic fluorescent pyrimidines, comprising a 1,2,4‐triazine motif conjugated to a thiophene (1 a) or a furan (1 b), are described. Although structurally related to their 5‐modified uridine counterparts, these modified 6‐aza‐uridines reveal dramatically improved fluorescence properties and a remarkable sensitivity to polarity and pH changes. The thiophene derivative 1 a has an absorption maximum around 335 nm, which upon excitation yields visible emission with a polarity‐sensitive maximum and fluorescence quantum yield ranging from 415 nm (Φ=0.8) to 455 nm (Φ=0.2) in dioxane and water, respectively. Nucleoside 1 a also displays susceptibility to acidity. Correlating emission intensity and solution pH yields a pKa value of 6.7–6.9, reasonably close to physiological pH values. The results illustrate that highly sought‐after fluorescence features (brightness and responsiveness) are not necessarily the trait of large fluorophores alone, but can be observed with probes that meet stringent isomorphic design criteria.
Fructose Dehydration to 5‐Hydroxymethylfurfural over Solid Acid Catalysts in a Biphasic System
Authors: Ordomsky Vitaly V. , van der Schaaf John , Schouten Jaap C. , Nijhuis T. Alexander
Published: July 2012

Different acidic heterogeneous catalysts like alumina, aluminosilicate, zirconium phosphate, niobic acid, ion‐exchange resin Amberlyst‐15, and zeolite MOR have been studied in fructose dehydration to 5‐hydroxymethylfurfural (HMF). The acidity of these materials was characterized using temperature‐programmed desorption of NH3 and IR spectroscopy of adsorbed pyridine. The nature and strength of acid sites was shown to play a crucial role in the selectivity towards HMF. Brønsted acid sites in the case of zeolites and ion‐exchange resin led to high selectivities in the dehydration of fructose with an increase in selectivity with the addition of an organic phase. Lewis acidity in the case of phosphate and oxides resulted in the intensive production of humins from fructose at the initial stages of the process, whereas organic phase addition did not affect selectivity.
Ethanol influences on bax associations with mitochondrial membrane proteins in neonatal rat cerebellum
Authors: Heaton Marieta Barrow , Siler‐Marsiglio Kendra , Paiva Michael , Kotler Alexandra , Rogozinski Jonathan , Kubovec Stacey , Coursen Mary , Madorsky Vladimir
Published: July 2012

These studies investigated interactions taking place at the mitochondrial membrane in neonatal rat cerebellum following ethanol exposure and focused on interactions between proapoptotic Bax and proteins of the permeability transition pore (PTP), voltage‐dependent anion channel (VDAC) and adenine nucleotide translocator (ANT) of the outer and inner mitochondrial membranes, respectively. Cultured cerebellar granule cells were used to assess the role of these interactions in ethanol neurotoxicity. Analyses were made at the age of maximal cerebellar ethanol vulnerability (P4), compared to the later age of relative resistance (P7), to determine whether differential ethanol sensitivity was mirrored by differences in these molecular interactions. We found that, following ethanol exposure, Bax proapoptotic associations with both VDAC and ANT were increased, particularly at the age of greater ethanol sensitivity, and these interactions were sustained at this age for at least 2 h postexposure. Since Bax:VDAC interactions disrupt protective VDAC interactions with mitochondrial hexokinase (HXK), we also assessed VDAC:HXK associations following ethanol treatment and found such interactions were altered by ethanol treatment, but only at 2 h postexposure and only in the P4, ethanol‐sensitive cerebellum. Ethanol neurotoxicity in cultured neuronal preparations was abolished by pharmacological inhibition of both VDAC and ANT interactions with Bax but not by a Bax channel blocker. Therefore, we conclude that, at this age, within the constraints of our experimental model, a primary mode of Bax‐induced initiation of the apoptosis cascade following ethanol insult involves interactions with proteins of the PTP complex and not channel formation independent of PTP constituents. © 2012 Wiley Periodicals, Inc. Develop Neurobiol, 2013
Cell‐Compatible Fluorescent Chemosensor for Zn2+ Based on a 3,8‐Extended 1,10‐Phenanthroline Derivative
Authors: Zhang Bo , Cao Kou‐Sen , Xu Ze‐An , Yang Zhe‐Qin , Chen Hao‐Wen , Huang Wei , Yin Gui , You Xiao‐Zeng
Published: July 2012

A new 1,10‐phenanthroline (Phen) derivative, 3,8‐bis(5‐methylthiophen‐2‐yl)‐1,10‐phenanthroline (PHT1), has been synthesized and fully characterized including by single‐crystal X‐ray structure analysis. The electron‐donating effects of the two 5‐methylthiophene groups lead to distinctive fluorescence emission enhancement on complexation with Zn2+ compared with non‐emissive Phen. However, PHT1 shows stronger Zn2+‐sensing ability than 3,8‐bis(thiophen‐2‐yl)‐1,10‐phenanthroline (PHT0) or 3,8‐bis(3‐methylthiophen‐2‐yl)‐1,10‐phenanthroline (PHT2) and longer‐wavelength fluorescence emission (λem = 461 nm), which is vital for studies of living systems, mainly because of the lower steric hindrance and the electron‐donating effects of the 5‐methyl groups on the thiophene rings. More interestingly, PHT1 displays high selectivity towards Zn2+ over a broad range of pH and has an extremely low detection limit (5 ppb). An approximately 51‐fold Zn2+‐selective CHEF response has been attributed to the formation of a 1:2 metal–ligand complex, and the association equilibrium constant (Kass0) of [Zn(PHT1)2](ClO4)2 was determined to be 3.4 × 1012. Anionic effects and variations in the 1H NMR spectra before and after zinc(II) ion complextion were observed. Moreover, the ability of probe PHT1 to sense Zn2+ within living HL‐60, yeast, and HepG‐2 cells has been explored, and the Zn2+‐probing process in living cells was found to be reversible with a zinc chelator solution of N,N,N′,N′‐tetrakis(2‐pyridylmethyl)ethylenediamine (TPEN).
An Insight into the Reversible Dissociation and Chemical Reactivity of a Sterically Encumbered Diphosphane
Authors: Förster Daniela , Dilger Herbert , Ehret Fabian , Nieger Martin , Gudat Dietrich
Published: July 2012

The known 1,1′,3,3′‐tetrahydro‐2,2′‐bi‐1,3,2‐diazaphosphole 4a was for the first time synthesized on a preparative scale and characterized by spectroscopy. Equilibrium constants for the dissociation 4a [rlarr2] 2 5a were determined from quantitative variable‐temperature electron paramagnetic resonance(VT‐EPR) studies and were used to obtain thermochemical data for the P–P bond homolysis. The calculated bond dissociation energy of 79(1) kJ mol–1 is substantially lower than the gas‐phase dissociation energies of small diphosphanes. Modeling of the molecular structure of 4a by DFT calculations was feasible if dispersion effects were included, but the calculations still failed to give a reasonable account of the energetics of the dissociation process. Chemical reactions of 4a with alkynes proceeded, depending on substrate structure, either as a radical‐induced diphosphanation of the triple bond or by a nonradical reaction to give an unprecedented ring metathesis.
Enhanced dissolution of the substrate d,l‐2‐amino‐Δ2‐thiazoline‐4‐carboxylic acid and enzymatic production of l‐cysteine at high concentrations
Authors: Youn Sung Hun , Park Hae Woong , Shin Chul Soo
Published: July 2012

l‐Cysteine is widely used as a precursor in the pharmaceutical, cosmetic, food, and feed additive industries. It has been industrially produced from hydrolysis of human and animal hairs, which is limited for industrial production. At the same time, chemical hydrolysis causes the formation of intractable waste material. Thus, environmentally friendly methods have been developed. A big obstacle of currently available methods is the low substrate solubility leading to poor l‐cysteine yield. Here, a method for improving the low solubility of the substrate d,l‐2‐amino‐Δ2‐thiazoline‐4‐carboxylic acid (d,l‐ATC) is presented and the enzymatic reaction at high concentration levels was optimized. The substrate was dissolved in large amounts in aqueous solutions by pH control using salts. d,l‐ATC solubility increased with an increasing solution pH due to its enhanced hydrophilicity, which can be achieved by a shift to dissociated carboxylic group (–COO−). The highest d,l‐ATC solubility of 610 mM was obtained at pH 10.5. The maximum l‐cysteine yield of 250 mM was attained at pH 9.1, which lies between the optimum values for high substrate solubility and reaction rate. The product yield could be increased by more than 10 times compared to those in previous reports, which is industrially meaningful.
Kinematics of an alpine retrogressive rockslide in the Japanese Alps
Authors: Nishii Ryoko , Matsuoka Norikazu
Published: July 2012

The Aresawa rockslide in the Japanese Alps experienced a partial collapse (5–10 × 105 m3) in 2004, followed by an accelerated downward movement of the head area rather than stabilization. This paper discusses the kinematics of a retrogressive rockslide area and factors promoting slope instability subsequent to the 2004 collapse, on the basis of geodetic surveys and meteorological observations from 2006 to 2010. The unstable area covers at least 2·3 × 104 m2 and consists of five active blocks. The main blocks are separated from the stable rock slope by pre‐existing ‘sackung features’ that follow the strike of the bedding plane. Shear zones below these sackung features have developed into slip planes potentially causing the next collapse. In particular, the propagation of a slip plane causing movement at 70 cm yr−1 in the head area is promoted by bidirectional movement. It consists of slow ‘dip‐slip’ movement in snow‐accumulating periods and rapid ‘side‐slip’ movement in snow‐melting and snow‐free periods, both of which occur on the same slip plane. This bidirectional movement appears to result from the combination of a loss of lateral support by the 2004 event and the immature state of the slip plane. The primary trigger of the acceleration in the unstable area is the stress release by the 2004 collapse. In addition, the presence of a potential slip plane below the sackung features also promotes slope instability, suggesting that sackung features behind a rockslide area may predefine the new head scarp of a forthcoming collapse. Copyright © 2012 John Wiley & Sons, Ltd.
Assessing aeolian beach‐surface dynamics using a remote sensing approach
Authors: Delgado‐Fernandez Irene , Davidson‐Arnott Robin , Bauer Bernard O. , Walker Ian J. , Ollerhead Jeff , Rhew Hosahng
Published: July 2012

A remote sensing technique for assessing beach surface moisture was used to provide insight into beach‐surface evolution during an aeolian event. An experiment was carried out on 21 October 2007 at Greenwich Dunes, Prince Edward Island National Park, Canada, during which cameras were mounted on a mast on the foredune crest at a height of about 14 m above the beach. Maps of beach surface moisture were created based on a calibrated relationship between surface brightness from the photographs and surface moisture content measured in situ at points spaced every 2.5 m along a transect using a Delta‐T moisture probe. A time sequence of maps of surface moisture content captured beach surface evolution through the transport event at a spatial and temporal resolution that would be difficult to achieve with other sampling techniques such as impedance probes. Erosion of the foreshore and berm crest resulted in an increase in surface moisture content in these areas as the wetter underlying sediments were exposed. Flow expansion downwind of the berm crest led to sand deposition and a consequent decrease in surface moisture content. Remote sensing systems such as the one presented here allow observations of the combined evolution of beach surface moisture, shoreline position, and fetch distances during short‐term experiments and hence provide a comprehensive rendering of sediment erosion and transport processes. Copyright © 2012 John Wiley & Sons, Ltd.
Double‐diffusive natural convection in a partially heated enclosure using a nanofluid
Authors: Parvin Salma , Nasrin Rehena , Alim M.A. , Hossain N.F.
Published: July 2012

This paper analyzes numerically the effect of double‐diffusive natural convection of a water–Al2O3 nanofluid in a partially heated enclosure with Soret and Dufour coefficients. The top horizontal wall has constant temperature Tc, while the bottom wall is partially heated Th, with Th > Tc . The concentration in the top wall is maintained higher than the bottom wall Cc < Ch. The remaining bottom wall and the two vertical walls are considered adiabatic. Water is considered as the base fluid. The governing equations are solved by the Penalty Finite Element Method using Galerkin's weighted residual scheme. The effect of the parameters, namely, Rayleigh number and solid volume fraction of the nanoparticles on the flow pattern and heat and mass transfer has been depicted. Comprehensive average Nusselt and Sherwood numbers, average temperature and concentration, and mid‐height horizontal and vertical velocities at the middle of the cavity are presented as functions of the governing parameters mentioned above. © 2012 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley Online Library (wileyonlinelibrary.com/journal/htj). DOI 10.1002/htj.21010
Use of the Diagnostic Classification of Mental Health and Developmental Disorders of Infancy and Early Childhood: Revised Edition (DC:0–3R) with Canadian Infants and Young Children Prenatally Exposed to Substances
Authors: Motz Mary , Espinet Stacey D. , Jeong Jessica Jeihyun , Zimmerman Patricia , Chamberlin Julie , Pepler Debra J.
Published: July 2012

The current study examined the mental health diagnostic profiles of infants and young children prenatally exposed to substances using the Diagnostic Classification of Mental Health and Developmental Disorders of Infancy and Early Childhood, Revised (DC:0–3R) diagnostic system. Participants were 46 biological mother–infant dyads who were engaged in a clinical program for mothers with substance‐use problems and their young children (aged 10–41 months). Diagnostic information was reported for each of the five axes listed in the DC:0–3R diagnostic system based on file reviews. In addition, the children's socioemotional and adaptive behaviors were assessed using the Child Behavior Checklist, Infant–Toddler Social Emotional Assessment, the Social‐Emotional Scale, and the Adaptive Behavior Assessment System (2nd ed.). In this sample of young children with prenatal substance exposure, a broad range of socioemotional symptoms were evident, with almost one third of the children meeting criteria for at least one Axis I mental health diagnosis. In addition, the majority of dyads demonstrated features of a disordered relationship. Children in more problematic relationships demonstrated higher levels of socioemotional and adaptive functioning difficulties and were more likely to have an Axis I diagnosis than were children in adapted relationships. The importance of early intervention efforts aimed at infants with prenatal substance exposure and their biological mothers is highlighted, with a particular focus on enhancing the quality of the mother–child relationship.
Encapsulation of protein microfiber networks supporting pancreatic islets
Authors: Steele Joseph A. M. , Barron Annelise E. , Carmona Euridice , Hallé Jean‐Pierre , Neufeld Ronald J.
Published: July 2012

Networks of discrete, genipin‐crosslinked gelatin microfibers enveloping pancreatic islets were incorporated within barium alginate microcapsules. This novel technique enabled encapsulation of cellular aggregates in a spherical fibrous matrix <300 μm in diameter. Microfibers were produced by vortex‐drawn extrusion within an alginate support matrix. Optimization culminated in a hydrated fiber diameter of 22.3 ± 0.4 μm, a significant reduction relative to that available through current gelatin microfiber spinning techniques, while making the process more reliable and less labor intensive. Microfibers were encapsulated at 40 vol % within 294 ± 4 μm 1.6% barium alginate microparticles by electrostatic‐mediated dropwise extrusion. Pancreatic islets extracted from Sprague Dawley rats were encapsulated within the microparticles and analyzed over 21 days. Acridine orange and propidium iodide fluorescent viability staining and light microscopy indicated a significant increase in viability for islets within the fiber‐embedded particles relative to fiber‐free controls at days 7, 14, and 21. The fiber‐embedded system also promoted cellular aggregate cohesion, reducing the incidence of dispersed islet morphologies within the capsules from 31 to 8% at day 21. Further enquiry into benefits of islet encapsulation within a protein fiber network will be the subject of future investigation. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 100A:3384–3391, 2012.
Bone material properties in premenopausal women with idiopathic osteoporosis
Authors: Misof Barbara M , Gamsjaeger Sonja , Cohen Adi , Hofstetter Birgit , Roschger Paul , Stein Emily , Nickolas Thomas L , Rogers Halley F , Dempster David , Zhou Hua , Recker Robert , Lappe Joan , McMahon Donald , Paschalis Eleftherios P , Fratzl Peter , Shane Elizabeth , Klaushofer Klaus
Published: July 2012

Idiopathic osteoporosis (IOP) in premenopausal women is characterized by fragility fractures at low or normal bone mineral density (BMD) in otherwise healthy women with normal gonadal function. Histomorphometric analysis of transiliac bone biopsy samples has revealed microarchitectural deterioration of cancellous bone and thinner cortices. To examine bone material quality, we measured the bone mineralization density distribution (BMDD) in biopsy samples by quantitative backscattered electron imaging (qBEI), and mineral/matrix ratio, mineral crystallinity/maturity, relative proteoglycan content, and collagen cross-link ratio at actively bone forming trabecular surfaces by Raman microspectroscopy and Fourier transform infrared microspectroscopy (FTIRM) techniques. The study groups included: premenopausal women with idiopathic fractures (IOP, n = 45), or idiopathic low BMD (Z-score ≤ −2.0 at spine and/or hip) but no fractures (ILBMD, n = 19), and healthy controls (CONTROL, n = 38). BMDD of cancellous bone showed slightly lower mineral content in IOP (both the average degree of mineralization of cancellous bone [Cn.CaMean] and mode calcium concentration [Cn.CaPeak] are 1.4% lower) and in ILBMD (both are 1.6% lower, p < 0.05) versus CONTROL, but no difference between IOP and ILBMD. Similar differences were found when affected groups were combined versus CONTROL. The differences remained significant after adjustment for cancellous mineralizing surface (MS/BS), suggesting that the reduced mineralization of bone matrix cannot be completely accounted for by differences in bone turnover. Raman microspectroscopy and FTIRM analysis at forming bone surfaces showed no differences between combined IOP/ILBMD groups versus CONTROL, with the exceptions of increased proteoglycan content per mineral content and increased collagen cross-link ratio. When the two affected subgroups were considered individually, mineral/matrix ratio and collagen cross-link ratio were higher in IOP than ILBMD. In conclusion, our findings suggest that bone material properties differ between premenopausal women with IOP/ILBMD and normal controls. In particular, the altered collagen properties at sites of active bone formation support the hypothesis that affected women have osteoblast dysfunction that may play a role in bone fragility. © 2012 American Society for Bone and Mineral Research.
Milestones for Apheresis education
Authors: Marshall Carol S. , Andrzejewski Chester , Carey Patricia M. , Crookston Kendall P. , Li Yanhua , Lopez‐Plaza Ileana , Sachais Bruce S. , Schwartz Joseph , Winters Jeffrey L. , Wong Edward C. C. , Wu YanYun
Published: July 2012

Milestones represent the essential knowledge, skills, and attitudes required for the practice of a medical discipline. Defining these milestones for each medical specialty has become a focus for the American Council of Graduate Medical Education (ACGME). Practitioners of Apheresis Medicine come from a variety of medical specialties making it challenging to establish the essential educational milestones for all. The American Society for Apheresis (ASFA) has an interest in promoting standards of excellence for Apheresis Medicine. ASFA's Physician's Curriculum Content Committee is a group of physician educators in the field of Apheresis Medicine, both donor and therapeutic, from across the United States, who have met regularly for several years to discuss the appropriate educational milestones in Apheresis training. The committee members teach residents and fellows from Pathology, Transfusion Medicine, Hematology/Oncology, Nephrology and other specialties. In this document, we have outlined the basic set of Apheresis milestones required in the ACGME defined competency areas of Patient Care and Medical Knowledge. We have also recommended methods of evaluation and estimated the time necessary for the acquisition of these cognitive and behavioral elements. J. Clin. Apheresis 27:242–246, 2012. © 2012 Wiley Periodicals, Inc.
Explaining the Covariance Between Attention‐Deficit Hyperactivity Disorder Symptoms and Depressive Symptoms: The Role of Hedonic Responsivity
Authors: Meinzer Michael C. , Pettit Jeremy W. , Leventhal Adam M. , Hill Ryan M.
Published: July 2012

Objective

The aim of this study was to examine low hedonic responsivity, a facet of hedonic capacity, as a potential explanatory variable in the relationship between attention deficit/hyperactivity disorder (ADHD) symptoms and depressive symptoms.

Method

One hundred ninety‐eight undergraduate students (mean age = 21.3, standard deviation = 4.6; 59.6% women) from a large, public university completed self‐report measures for this cross‐sectional study.

Results

Results indicated that ADHD symptoms were significantly associated with depressive symptoms, and that low hedonic responsivity partially accounted for this association. This effect was statistically significant for total ADHD symptoms and inattentive symptoms, but not for hyperactive‐impulsive symptoms.

Conclusions

Findings are consistent with the possibility that impaired hedonic responsiveness may be a common endophenotype for depression and the inattentive symptoms of ADHD. Implications for future research and clinical work are discussed.
The Role of Anxiety Sensitivity, Behavioral Inhibition, and Cognitive Biases in Anxiety Symptoms: Structural Equation Modeling of Direct and Indirect Pathways
Authors: Viana Andres G. , Gratz Kim L.
Published: July 2012

Objective(s):

Limited research has examined how temperamental (i.e., behavioral inhibition, anxiety sensitivity) and cognitive (i.e., interpretive and judgment biases) risks for the development anxiety covary to influence anxiety symptoms. Thus, the present study aimed to advance understanding of the direct and indirect links between anxiety sensitivity, behavioral inhibition, and interpretive biases, and judgment biases (in the form of perceived control) to anxiety outcomes (i.e., worry and trait anxiety symptoms).

Method:

842 emerging adults (mean = 18.75 years, standard deviation = 1.05; age range = 18–24; 70% women) recruited from a university in the northeast participated in this study. Participants completed a battery of self‐report measures assessing risk factors and anxiety outcomes of interest.

Results:

Structural equation modeling revealed anxiety sensitivity and behavioral inhibition were directly linked with anxiety outcomes. Anxiety sensitivity and behavioral inhibition were also indirectly linked with anxiety outcomes through interpretive and judgment biases. The hypothesized model was partially invariant across high‐risk and low‐risk groups for anxiety disorders.

Conclusions:

Results of this study provide preliminary support for theoretical models hypothesizing a developmental progression from temperamental to cognitive risks and culminating in the expression of anxiety symptoms. Limitations and clinical implications of this research are discussed. © 2012 Wiley Periodicals, Inc. J. Clin. Psychol. 00:1‐20, 2012.
Different concentrations of grape seed extract affect in vitro starch fermentation by porcine small and large intestinal inocula
Authors: Wang Dongjie , Williams Barbara A , Ferruzzi Mario G , D'Arcy Bruce R
Published: July 2012

BACKGROUND: Grape seed extract (GSE) phenolics have potential health‐promoting properties, either from compounds present within the extract, or metabolites resulting from gastrointestinal tract (GIT) fermentation of these compounds. This study describes how GSE affected the kinetics and end‐products of starch fermentation in vitro using pig intestinal and fecal inocula. Six GSE concentrations (0, 60, 125, 250, 500, and 750 µg ml−1 were fermented in vitro by porcine ileal and fecal microbiota using starch as the energy source. Cumulative gas production, and end‐point short chain fatty acids and ammonia were measured.

RESULTS: GSE phenolics altered the pattern (gas kinetics, and end‐products such as SCFA and NH$_{4}^{+}$) of starch fermentation by both inocula, at concentrations above 250 µg ml−1. Below this level, neither inoculum showed any significant (P > 0.05) effect of the GSE.

CONCLUSION: The results show that GSE phenolics at a concentration over 250 µg ml−1 can have measurable effects on microbial activity in an in vitro fermentation system, as evidenced by the changes in kinetics and end‐products from starch fermentation. This suggests that fermentation patterns could be conceivably shifted in the actual GIT, though further evidence will be required from in vivo studies. Copyright © 2012 Society of Chemical Industry
Effects of high‐pressure processing and enzymatic dephosphorylation on phosvitin properties
Authors: Volk Stephanie P , Ahn Dong U , Zeece Michael , Jung Stephanie
Published: July 2012

BACKGROUND: Egg phosvitin could be a good source of functional peptides. Enzymatic dephosphorylation and high‐pressure processing combined with thermal treatment applied before proteolysis could produce phosvitin hydrolysates with different properties compared to its native form.

RESULTS: Phosvitin structure was maintained overall during high‐pressure treatment of 600 MPa applied at an initial temperature of 65 °C regardless of the pH and duration of treatment, confirming the high structural stability of this phosphoprotein. Treatment of phosvitin with phosphatase increased the degree of dephosphorylation from 24% to 63%, after 2 and 18 h, respectively. Moderate dephosphorylation of phosvitin prior to proteolytic digestion improved its hydrolysis, allowing formation of peptides with a molecular weight lower than 17,000 kDa as determined by size exclusion chromatography. Angiotensin‐converting enzyme (ACE) inhibition and antioxidant activity of dephosphorylated and protease‐treated phosvitin was increased by 52% and 39%, respectively, as compared to protease‐digested native phosvitin.

CONCLUSION: Enzymatic dephosphorylation before proteolysis mimicking in vivo gut conditions improved ACE inhibition and antioxidant activity of phosvitin hydrolysates. Copyright © 2012 Society of Chemical Industry
Using persuasive messages to encourage hunters to support regulation of lead shot
Authors: Schroeder Susan A. , Fulton David C. , Penning William , Doncarlos Kathy
Published: July 2012

Lead shot from hunting adds the toxic metal to environments worldwide. The United States banned lead shot for hunting waterfowl in 1991 and 26 states have lead shot restrictions beyond those mandated for waterfowl hunting. The Minnesota Department of Natural Resources (MDNR) was interested in studying hunter attitudes about expanded restrictions on the use of lead shot for hunting small game to understand what communication strategies might increase public support for potential restrictions on lead shot. We mailed messages about lead shot, including 1,200 control messages and 400 of each of 9 treatment messages, and surveys to 4,800 resident small game hunters. We compared attitudes and intentions related to a possible ban among control and treatment groups. Compared to the control message, all treatment messages elicited more positive attitudes and intentions to support a ban. A basic factual message, messages with references to Ducks Unlimited, and a first‐person narrative message generated the strongest support for a ban. Results also demonstrated a substantial relationship between the use of lead shot and response to persuasive messages supporting a ban. © 2012 The Wildlife Society.
Towards a More Articulated Typology of Internally Headed Relative Constructions: The Semantics Connection
Authors: Grosu Alexander
Published: July 2012

This article outlines the shortcomings found in two well‐known syntax‐based typologies of internally headed relative constructions (IHRCs), and demonstrates the benefits of a typology that relies on the syntax‐semantics interface and takes semantics seriously into account. It is argued that the latter approach yields a more revealing and empirically superior typology of IHRCs.
Study of blood charring precursor states using backscattering at 663 nm from blood and optical window boundary
Authors: Takahashi Mei , Ito Arisa , Miyoshi Shunichiro , Kimura Takehiro , Takatsuki Seiji , Fukumoto Kotaro , Fukuda Keiichi , Arai Tsunenori
Published: July 2012

Background and Objective

Contact laser irradiation is generally used in therapeutic laser procedures such as plastic surgery and laser catheter lead removal. However, it may induce blood charring on the surface of the optical window in blood circumstance so that the laser beam might be blocked. Various charring detection methods have been proposed, but they detect charring only after charring has occurred. This study investigates the transient behavior of red blood cells (RBCs) prior to the charring on the surface of an optical window during red laser irradiation in blood circumstance.

Materials and Methods

The backscattering light power was continuously measured to investigate the transient behavior of a 1‐mm‐thick porcine blood model (hematocrit: 40%) during continuous laser irradiation (center wavelength: 663 nm; irradiance: 81 W/cm2). A rabbit blood model was microscopically observed after irradiation. The absorption coefficient (µa) and the reduced scattering coefficient ($\mu '_{{\rm s}} $) were measured using a double integrating sphere setup and the inverse adding–doubling method. The backscattering light power was continuously measured in vivo during contact laser irradiation via a laser catheter in a porcine heart cavity.

Results

The results reveal that it may be possible to detect a precursory state of charring from a time course of the backscattering light power. µa increased monotonically by 15% until charring occurred. $\mu '_{{\rm s}} $ decreased by 10% followed a broad peak until charring occurred. These changes in the optical property correspond to changes in the morphology of RBCs. Changes in the backscattering light power measured in vivo were similar to those measured ex vivo.

Conclusions

The transient optical changes in blood prior to charring may be caused by changes in the morphology of RBCs on the optical window surface. Backscattering light power measurements may be a practical method to detect the precursor state of charring. Lasers Surg. Med. 44: 508–513, 2012. © Wiley Periodicals, Inc.
Preoperative prediction of the microvascular invasion of hepatocellular carcinoma with diffusion-weighted imaging
Authors: Suh Young Joo , Kim Myeong-Jin , Choi Jin-Young , Park Mi-Suk , Kim Ki Whang
Published: July 2012

The aim of this study was to investigate whether diffusion-weighted imaging (DWI) could be useful in predicting the microvascular invasion (MVI) of hepatocellular carcinoma (HCC). Sixty-seven surgically proven HCCs from 65 patients (54 men and 11 women with an age range of 35-75 years and a mean age of 56.0 years) were retrospectively analyzed. The signal intensities (SIs) of the lesions on preoperative diffusion-weighted (DW) images were visually categorized as isointense or hyperintense in comparison with the adjacent liver. We also quantitatively measured SIs and apparent diffusion coefficients (ADCs) by drawing regions of interest in HCCs and livers on DW images with b values of 50, 400, and 800 second/mm2 and on ADC map images. Logistic regression analyses were performed so that we could identify independent predictors of MVI among laboratory and DWI findings. A univariate analysis showed that a histological grade of 3, a larger tumor size, a higher SI ratio on DW images, and a lower ADC value were significantly associated with MVI. A multiple logistic regression analysis showed that a histological grade of 3 and the ADC value were independent predictors of MVI. With a cutoff of 1.11 × 10−3 mm2/second, the ADC value provided a sensitivity of 93.5% and a specificity of 72.2% for the prediction of MVI with an odds ratio of 24.5 (95% confidence interval = 4.14-144.8, P < 0.001). In conclusion, lower ADC values (1.11 × 10−3 mm2/second or less) can be a useful predictor of MVI during the preoperative evaluation of HCC. Liver Transpl 18:1171–1178, 2012. © 2012 AASLD.
Orchestrating Cell/Material Interactions For Tissue Engineering of Surgical Implants
Authors: de Mel Achala , Seifalian Alexander M. , Birchall Martin A.
Published: July 2012

Research groups are currently recognising a critical clinical need for innovative approaches to organ failure and agenesis. Allografting, autologous reconstruction and prosthetics are hampered with severe limitations. Pertinently, readily available ‘laboratory‐grown’ organs and implants are becoming a reality. Tissue engineering constructs vary in their design complexity depending on the specific structural and functional demands. Expeditious methods on integrating autologous stem cells onto nanoarchitectured 3D nanocomposites, are being transferred from lab to patients with a number of successful first‐in‐man experiences. Despite the need for a complete understanding of cell/material interactions tissue engineering is offering a plethora of exciting possibilities in regenerative medicine.

magnified image
Accelerated Ambient‐Temperature ATRP of Methyl Acrylate in Alcohol–Water Solutions with a Mixed Transition‐Metal Catalyst System
Authors: Abreu Carlos M. R. , Mendonça Patrícia V. , Serra Arménio C. , Coelho Jorge F. J. , Popov Anatoliy V. , Guliashvili Tamaz
Published: July 2012

The current trend in developing next‐generation LRP systems and in particular ATRP involves reduction, elimination, and/or replacement of toxic and highly expensive catalysts and solvents with environmently friendly ones. Here, the unexpected, accelerated, ambient‐temperature ATRP of methyl acrylate catalyzed by a Fe(0)/CuBr2/Me6TREN system in a mixture of water and inexpensive and environmentally more friendly alcohols (methanol, ethanol, and 1‐propanol) is reported. The data presented open up the possibility of using fast ATRP catalyzed by a mixed transition‐metal catalyst system in solvents that are inexpensive, eco‐friendly, and have low boiling points.
Effect of Chemical Structure and Charge Distribution on Behavior of Polyzwitterions in Solution
Authors: Lezov A. A. , Vlasov P. S. , Polushina G. E. , Lezov A. V.
Published: July 2012

Summary: The hydrodynamic and conformational properties of polyelectrolyte poly(N,N‐diallyl‐N,N‐dimethylammonium chloride) and its corresponding polybetaine poly(2‐diallyl(methyl)ammonio)acetate) molecules in aqueous solutions with various ionic strength and pH, were studied by viscometry, static and dynamic light scattering methods. It was established that a 1 M NaCl solution is a thermodynamically good solvent for poly(N,N‐diallyl‐N,N‐dimethylammonium chloride). In water solutions conformation of poly(2‐diallyl(methyl)ammonio)acetate) molecules corresponds to polymer coil under θ–conditions. An increase in the concentration of NaCl in water and 0.1M NaOH solutions from 0 to 1 mol/l brings about a sharp gain in the intrinsic viscosity of the polymer and in the hydrodynamic radius of molecules. This effect results from the decomposition of zwitterion pairs responsible for the compact conformation of polymer molecules in water and 0.1 M NaOH. The Kuhn segment length for poly(2‐diallyl(methyl)ammonio)acetate) molecules A = 6.3 nm determined in water and in 0.1 M NaOH solutions practically coincided with A value 6.6 nm, received in 1 M NaCl and in 0.1 M NaOH/1M NaCl. For poly(N,N‐diallyl‐N,N‐dimethylammonium chloride) molecules in 1 M NaCl solutions A = 3.9 nm.
Hydrodynamic Properties of “Pseudo‐Dendrimer”
Authors: Filippov Alexander P. , Amirova Alina I. , Belyaeva Elena V. , Tarabukina Elena B. , Sheremetyeva Natalia A. , Muzafarov Aziz M.
Published: July 2012

Summary: Hyperbranched polycarbosilane with terminal butyl groups is obtained by chemical modification of hyperbranched polyallylcarbosilane using the reaction of hydrosilylation with methyldichlorosilane, followed by treatment of the polychlorosilyl derivative with butyllithium. Its hydrodynamic and conformational properties are studied by the methods of light scattering, sedimentation‐diffusion analysis, and viscosimetry in dilute solutions of methyl‐tert‐butyl ether, hexane, THF, chloroform, and toluene. The results obtained are compared with the data for the initial polyallylcarbosilane and carbosilane dendrimer with butyl terminal groups. It is demonstrated that branching regularity is the decisive factor determining the solution properties at fixed degree of the branching.
Dynamic Mechanical Analysis and Molecular Mobility of the R‐BAPB Type Polyimide
Authors: Toshchevikov V. P. , Smirnova V. E. , Yudin V. E. , Svetlichnyi V. M.
Published: July 2012

Summary:Dynamic mechanical experiments are performed to study molecular mobility of the R‐BAPB type polyimide based on 1,3‐bis‐(3,3′,4,4′‐dicarboxyphenoxy)benzene (R) and 4,4′‐bis‐(4‐aminophenoxy)biphenyl (BAPB) with a molecular weight Mw∼ 80 000 g/mol. Frequency dependences of the storage and the loss tensile moduli are measured within the temperature domain 199°C ≤ T ≤ 211°C that includes the glass transition temperature of the compound, Tg = 206°C. It is shown that the time‐temperature superposition principle holds for the R‐BAPB type polyimide. A theoretical analysis of the master curves constructed at Tref = 204°C is performed on the basis of the piecewise‐power‐type distribution function of the relaxation times. Relaxation times for typical scales of motion inside polyimide macromolecules are calculated and the molecular weights of the characteristic kinetic units (the Kuhn segment and the chain fragment between entanglements) are estimated.
Comparative Study of the Quantity of Volatile Organic Compounds in Water‐Based Paint and Solvent‐Based Applied Polyurethane
Authors: da Conceição Ailton R. , Pimenta Ednilson A. R. , Fujisawa Ronaldo S. , Nohara Evandro L.
Published: July 2012

Summary: The concern about the environmental impacts generated in the production of goods and services has increased last decades. The industry has used paints and varnishes in the manufacturing process have been pressed to improve air pollution prevention. Thus, the present work aims to identify the quantitative differences of VOC's and analyze the effect of VOC's in the burning rate, in a solvent and water‐based paint, applied in the manufacture of automotive steering wheels. The results has showed that the solvent‐based paint contains nine times more VOC's in your formulation in relation to water‐based paint, when compared liquid and volatile organic compounds present in the solvent‐based paint increase the speed of combustion of the polyurethanes samples. These data indicate that a discussion on the subject must be initiated in order to reduce these emissions that can harm society.
High frequency of Parkin exon rearrangements in Mexican‐mestizo patients with early‐onset Parkinson's disease
Authors: Camacho Jorge Luis Guerrero , Jaramillo Nancy Monroy , Gómez Petra Yescas , Violante Mayela Rodríguez , Woehrlen Catherine Boll , Vilatela Ma. Elisa Alonso , López López Marisol
Published: July 2012

Background:

Parkin mutations in patients with early‐onset Parkinson's disease (EOPD) are estimated to occur in 49% of familial cases and 18% of sporadic cases.

Methods:

We analyzed the entire sequence‐coding region and dosage mutations of parkin in 63 Mexican‐mestizo EOPD patients and 120 controls.

Results:

Parkin mutations were present in 34 patients (54.0%). Exon rearrangements, predominantly spanning exons 9 and 12 (31.7% and 19.0%, respectively) were present in 32 patients, with 17.5% carrying simple heterozygous and 25.4% carrying compound heterozygous parkin mutations.

Conclusions:

A higher frequency of parkin exon rearrangements than of sequence mutations was observed. Patients with parkin exons 9 and 12 rearrangements showed a later age at onset than did cases with other regions affected (40.3 ± 4.5 vs 30.1 ± 8.8; P = .005), suggesting a mutational hot spot in the etiology of Mexican‐mestizo patients with EOPD. To our knowledge, this study represents the largest sampling of Mexican‐mestizo patients with EOPD cases for which parkin sequence and dosage alterations were analyzed. © 2012 Movement Disorder Society
Clinical differences among mild cognitive impairment subtypes in Parkinson's disease
Authors: Goldman Jennifer G. , Weis Holly , Stebbins Glenn , Bernard Bryan , Goetz Christopher G.
Published: July 2012

Mild cognitive impairment is increasingly recognized as a construct in Parkinson's disease (PD) and occurs in about 25% of nondemented PD patients. Although executive dysfunction is the most frequent type of cognitive deficit in PD, the cognitive phenotype of PD mild cognitive impairment (PD‐MCI) is broad. PD‐MCI subtypes are represented by amnestic and nonamnestic domain impairment as well as single‐ and multiple‐domain impairment. However, it is unclear whether patients with different PD‐MCI subtypes also differ in other clinical characteristics in addition to cognitive profile. We studied 128 PD‐MCI subjects at our Movement Disorders center, comparing clinical, motor, and behavioral characteristics across the PD‐MCI subtypes. We found varying proportions of impairment subtypes: nonamnestic single domain, 47.7%; amnestic multiple domain, 24.2%; amnestic single domain, 18.8%; and nonamnestic multiple domain, 9.5%. Attentional/executive functioning and visuospatial abilities were the most frequently impaired domains. PD‐MCI subtypes differed in their motor features, with nonamnestic multiple‐domain PD‐MCI subjects showing particularly pronounced problems with postural instability and gait. Differences among PD‐MCI subtypes in age, PD duration, medication use, mood or behavioral disturbances, and vascular disease were not significant. Thus, in addition to differing cognitive profiles, PD‐MCI subtypes differed in motor phenotype and severity but not in mood, behavioral, or vascular comorbidities. Greater postural instability and gait disturbances in the nonamnestic multiple‐domain subtype emphasize shared nondopaminergic neural substrates of gait and cognition in PD. Furthermore, increased burden of cognitive dysfunction, rather than type of cognitive deficit, may be associated with greater motor impairment in PD‐MCI. © 2012 Movement Disorder Society
Detailed Microstructure Investigation of Acrylate/Methacrylate Functional Copolymers by Kinetic Monte Carlo Simulation
Authors: Hamzehlou Shaghayegh , Reyes Yuri , Leiza Jose R.
Published: July 2012

A kinetic Monte Carlo simulation model is developed to study the microstructure of acrylic functional copolymers, taking into account all complexities of acrylic kinetics like backbiting, β‐scission, and propagation to macromonomer. The model is used to study the bulk and solution copolymerization of butyl acrylate/hydroxyethyl methacrylate in batch and semibatch processes. The model is able to reproduce experimental findings, providing new information that might be difficult to obtain (if possible) by deterministic or experimental methods. With the simulation the influence of the polymerization conditions on the branching density and copolymer composition as a function of chain length are discussed.

magnified image
Macromolecule‐suppressed GABA‐edited magnetic resonance spectroscopy at 3T
Authors: Edden Richard A. E. , Puts Nicolaas A. J. , Barker Peter B.
Published: July 2012

Edited magnetic resonance spectroscopy makes possible noninvasive studies of the role of the inhibitory neurotransmitter GABA in the healthy brain and in disease processes. A major limitation of the methodology is coediting of macromolecular signals. Although it has previously been shown that macromolecular signal can be suppressed using a symmetrical editing scheme, this approach is rarely applied at field strength of 3T as insufficiently selective pulses result in loss of GABA signal (in addition to the intended suppression of macromolecular signal). In this article, the authors show that increasing the echo time to 80 ms lets more selective editing pulses be used, allowing for symmetric editing‐based suppression of coedited macromolecular signal without loss of GABA signal. The method is applied to acquire macromolecule‐suppressed GABA‐edited spectra in 10 healthy participants. Magn Reson Med, 2012. © 2012 Wiley Periodicals, Inc.
Kleine Partikel — große Hoffnung
Authors: Eckensberger David
Published: July 2012

Liegt in der Nanotechnologie die Zukunft der Medizin? Nanotechnik hilft bei Therapie und Diagnostik. Erste Produkte sind im Markt angekommen, weitere befinden sich in präklinischen oder klinischen Studien.
Stromspeicher: Radikal organisch
Authors: Janoschka Tobias , Hager Martin D. , Schubert Ulrich S.
Published: July 2012

Lithiumionenbatterie, Bleiakku und Co. sind für den Sprung von der konventionellen zur flexiblen, gedruckten organischen Elektronik wenig geeignet. Polymerbasierte, organische Radikalbatterien bieten einen effizienten Ausweg.
Wie die Evolution Symmetrie erzeugt — und wieder verliert
Authors: Groß Michael
Published: July 2012

Die molekularen Maschinen der Zelle bestehen meistens aus mehreren Proteinmolekülen. Oft sind diese identisch und hochgradig symmetrisch angeordnet, doch manchmal entwickeln sie sich auseinander.
Globale Chemikaliensicherheit
Authors: Karavezyris Vassilius , Koch‐Jugl Juliane
Published: July 2012

Die internationalen Besprechungen zum Chemikalienmanagement gehen in die dritte Runde. Zu den diskutierten Themen gehören Blei in Farben, Nanomaterialien und perfluorierte Chemikalien.