bluuebunny/crossref_metadata_2025_split huggingface dataset:
Right‐ and left‐handed three‐helix proteins. I. Experimental and simulation analysis of differences in folding and structure
Authors: Glyakina Anna V. , Pereyaslavets Leonid B. , Galzitskaya Oxana V. 
Published: April 2013

ABSTRACTDespite the large number of publications on three‐helix protein folding, there is no study devoted to the influence of handedness on the rate of three‐helix protein folding. From the experimental studies, we make a conclusion that the left‐handed three‐helix proteins fold faster than the right‐handed ones. What may explain this difference? An important question arising in this paper is whether the modeling of protein folding can catch the difference between the protein folding rates of proteins with similar structures but with different folding mechanisms. To answer this question, the folding of eight three‐helix proteins (four right‐handed and four left‐handed), which are similar in size, was modeled using the Monte Carlo and dynamic programming methods. The studies allowed us to determine the orders of folding of the secondary‐structure elements in these domains and amino acid residues which are important for the folding. The obtained data are in good correlation with each other and with the experimental data. Structural analysis of these proteins demonstrated that the left‐handed domains have a lesser number of contacts per residue and a smaller radius of cross section than the right‐handed domains. This may be one of the explanations of the observed fact. The same tendency is observed for the large dataset consisting of 332 three‐helix proteins (238 right‐ and 94 left‐handed). From our analysis, we found that the left‐handed three‐helix proteins have some less‐dense packing that should result in faster folding for some proteins as compared to the case of right‐handed proteins.Proteins 2013; © 2013 Wiley Periodicals, Inc.
Coenzyme Q10 quantification in muscle, fibroblasts and cerebrospinal fluid by liquid chromatography/tandem mass spectrometry using a novel deuterated internal standard
Authors: Duberley Kate E. C. , Hargreaves Iain P. , Chaiwatanasirikul Korn‐Anong , Heales Simon J. R. , Land John M. , Rahman Shamima , Mills Kevin , Eaton Simon 
Published: April 2013

RATIONALENeurological dysfunction is common in primary coenzyme Q10 (2,3‐dimethoxy, 5‐methyl, 6‐polyisoprene parabenzoquinone; CoQ10; ubiquinone) deficiencies, the most readily treatable subgroup of mitochondrial disorders. Therapeutic benefit from CoQ10 supplementation has also been noted in other neurodegenerative diseases. CoQ10 can be measured by high‐performance liquid chromatography (HPLC) in plasma, muscle or leucocytes; however, there is no reliable method to quantify CoQ10 in cerebrospinal fluid (CSF). Additionally, many methods use CoQ9, an endogenous ubiquinone in humans, as an internal standard.METHODSDeuterated CoQ10 (d6‐CoQ10) was synthesised by a novel, simple, method. Total CoQ10 was measured by liquid chromatography/tandem mass spectrometry (LC/MS/MS) using d6‐CoQ10 as internal standard and 5 mM methylamine as an ion‐pairing reagent. Chromatography was performed using a Hypsersil GOLD C4 column (150 × 3 mm, 3 µm).RESULTSCoQ10 levels were linear over a concentration range of 0–200 nM (R2 = 0.9995). The lower limit of detection was 2 nM. The inter‐assay coefficient of variation (CV) was 3.6% (10 nM) and 4.3% (20 nM), and intra‐assay CV 3.4% (10 nM) and 3.6% (20 nM). Reference ranges were established for CoQ10 in CSF (5.7–8.7 nM; n = 17), fibroblasts (57.0–121.6 pmol/mg; n = 50) and muscle (187.3–430.1 pmol/mg; n = 15).CONCLUSIONSUse of d6‐CoQ10 internal standard has enabled the development of a sensitive LC/MS/MS method to accurately determine total CoQ10 levels. Clinical applications of CSF CoQ10 determination include identification of patients with cerebral CoQ10 deficiency, and monitoring CSF CoQ10 levels following supplementation. Copyright © 2013 John Wiley & Sons, Ltd.
Speciation of platinum‐benzoylthiourea in the gas phase using electrospray ionization mass spectrometry and density functional theory
Authors: Kumar Pranaw , Jaison P. G. , Sundararajan Mahesh , Telmore Vijay M. , Ghosh Swapan K. , Aggarwal Suresh K. 
Published: April 2013

RATIONALEDetermining the speciation of platinum‐benzoylthiourea (Pt‐BTU) in the gas phase is a challenging task due to various reaction pathways and the conformational flexibility of the BTU ligand.METHODSElectrospray ionization mass spectrometry (ESI‐MS) experiments and density functional theory (DFT) based calculations were carried out to shed light on this complex reaction in the gas phase using K2PtCl4salt and BTU. Various Pt complexes were studied in both positive and negative ion modes of ESI‐MS using a quadrupole‐time‐of‐flight mass spectrometer. The effects of the ESI‐MS experimental parameters such as capillary voltage, pH and electrolyte on the peak intensity of the Pt‐BTU complex were investigated. DFT calculations employing B3LYP functional with the 6‐311++G** basis set were used to characterize the geometric parameters and fragmentation patterns of various Pt complexes in the gas phase.RESULTSIn the positive ion mode, complexes with differing numbers of BTU ligands coordinated to the metal ion were observed, whereas, in the negative ion mode, no species associated with BTU or with the solvent (acetonitrile) molecules were found. It was also found that Pt forms complexes with the BTU ligand in different stoichiometric ratios. For both Pt(BTU)2and Pt(BTU)3complexes, the BTU ligand undergoes deprotonation followed by bi‐dentate coordination. DFT calculations suggest that BTU can coordinate to Pt in bothcisandtransisomeric forms, which are nearly iso‐energetic with a slight preference towards thetrans‐isomer. The preference oftrans‐BTU binding is attributed to the exclusive retention of intra‐molecular hydrogen bonding which is absent in thecis‐form.CONCLUSIONSExperimental and theoretical calculations have shown that the gas‐phase interaction of BTU to Pt is very complex. The BTU ligand can coordinate to Pt in both mono‐dentate and bi‐dentate modes, the latter mode being favorable upon deprotonation of the BTU ligand. Furthermore, many close lying species with different geometric isomeric forms are found to be possible due to the presence of intra‐ and inter‐molecular hydrogen bonding. Copyright © 2013 John Wiley & Sons, Ltd.
The Association of Family Influence and Initial Interest in Science
Authors: DABNEY KATHERINE P. , CHAKRAVERTY DEVASMITA , TAI ROBERT H. 
Published: April 2013

ABSTRACTWith recent attention to improving scientific workforce development and student achievement, there has been a rise in effort to understand and encourage student engagement in physical science. This study examines the association of family influence and initial interest in science through multiple and logistic regression models. Research questions addressed include Controlling for demographic variables, are physical science doctoral students or scientists who report family as a primary source of interest in science, as opposed to those that do not, more likely to develop an early interest in science? And what specific forms of family support are associated with doctoral students or scientists who report family as a primary source of initial interest in science? The study uses survey data from Project Crossover (n= 4,285), a sequential mixed methods study that examines factors influencing entrance into physical science doctoral programs as well as the transition from graduate students to independent researcher. Results suggest that family interest in science facilitates earlier initial interest in science. Further analyses show that family influence shifts from parental occupation as the primary source of interest for the older generation of scientists to one of three influences (occupation, diversion or hobby, and encouragement) among doctoral students. © 2013Wiley Periodicals, Inc. Sci Ed 97:395–409, 2013
Synergetic Material and Structure Optimization Yields Robust Spider Web Anchorages
Authors: Pugno Nicola M. , Cranford Steven W. , Buehler Markus J. 
Published: April 2013

AbstractMillions of years of evolution have adapted spider webs to achieve a range of properties, including the well‐known capture of prey, with efficient use of materials. One feature that remains poorly understood is the attachment disc, a network of silk fibers that mechanically anchors a web to its environment. Experimental observations suggest that one possible attachment disc adheres to a substrate through multiple symmetrically branched structures composed of sub‐micrometer scale silk fibers. Here, a theoretical model is used to explore the adaptation of the strength of attachment of such an anchorage, and complementary mesoscale simulations are applied to demonstrate a novel mechanism of synergetic material and structural optimization, such that the maximum anchorage strength can be achieved regardless of the initial anchor placement or material type. The optimal delamination (peeling) angle is facilitated by the inherent extensibility of silk, and is attained automatically during the process of delamination. This concept of self‐optimizing peeling angle suggests that attachment discs do not require precise placement by the spider, irrespective of adhesion strength. Additional hierarchical branching of the anchorage increases efficiency, where both the delamination force and toughness modulus increase with a splitting of the cross‐sectional area.
Single Layer of Polymeric Cobalt Phthalocyanine: Promising Low‐Cost and High‐Activity Nanocatalysts for CO Oxidation
Authors: Deng Qingming , Zhao Lina , Gao Xingfa , Zhang Meng , Luo Youhua , Zhao Yuliang 
Published: April 2013

AbstractThe catalytic behavior of transition metals (Sc to Zn) combined in polymeric phthalocyanine (Pc) is investigated systematically by using first‐principles calculations. The results indicate that CoPc exhibits the highest catalytic activity for CO oxidation at room temperature with low energy barriers. By exploring the two well‐established mechanisms for CO oxidation with O2, namely, the Langmuir–Hinshelwood (LH) and the Eley–Rideal (ER) mechanisms, it is found that the first step of CO oxidation catalyzed by CoPc is the LH mechanism (CO + O2 → CO2 + O) with energy barrier as low as 0.65 eV. The second step proceeds via both ER and LH mechanisms (CO + O → CO2) with small energy barriers of 0.10 and 0.12 eV, respectively. The electronic resonance among Co‐3d, CO‐2π*, and O2‐2π* orbitals is responsible for the high activity of CoPc. These results have significant implications for a novel avenue to fabricate organometallic sheet nanocatalysts for CO oxidation with low cost and high activity.
Anthropological contributions to the study of climate: past, present, future
Authors: Hastrup Kirsten 
Published: April 2013

AbstractIn the world of climate science there is an increasing demand for contributions from the social sciences, given that the current processes of climate change deeply affect societies. This article is a response to this call, with specific focus on past and potential contributions from anthropology, as we have known it from the 19th century onwards. It is shown how through the ages, different anthropological interests have shaped distinct perspectives on the entanglement of society and nature. It is argued that the present global concerns about climate change necessitate a refashioning of anthropology, and make it expedient to pay attention to the emergent global imaginaries.WIREs Clim Change2013, 4:269–281. doi: 10.1002/wcc.219This article is categorized under:Climate, History, Society, Culture > Disciplinary Perspectives
Ezetimibe Impairs Uptake of Dietary Cholesterol Oxidation Products and Reduces Alterations in Hepatic Cholesterol Metabolism and Antioxidant Function in Rats
Authors: Terunuma Shoichiro , Kumata Noriko , Osada Kyoichi 
Published: April 2013

AbstractDietary cholesterol oxidation products (COP) induce various adverse effects, including development of atherosclerosis, modulation of lipid metabolism, and unfavorable changes in the antioxidant system. Therefore, we examined the effects of ezetimibe, a cholesterol absorption inhibitor on hepatic cholesterol metabolism and down‐regulation of the antioxidant system in rats fed COP. Rats were fed a purified diet containing 0.3 % COP with or without ezetimibe (0.07 mg/100 g body weight) for 27 days. Levels of COP in both the plasma and liver were lowered by ezetimibe through promotion of COP excretion into the feces. Reflecting this effect, an increase in the arteriosclerotic index and a reduction in the mRNA expression of hepatic cholesterol biosynthesis transcripts by dietary COP were observed. Moreover, the ferric reducing ability of the plasma also was significantly higher in rats fed COP plus ezetimibe than in those fed COP alone. Finally, we also observed that ezetimibe enhanced the down‐regulation of hepatic fatty acid synthesis in rats fed COP. Thus, ezetimibe, which inhibits the absorption of dietary COP from the small intestine, may exert preventive effects on dietary COP‐induced disruption of cholesterol and fatty acid metabolism in the liver and down‐regulation of the antioxidant system.
Effect of Accelerated Storage on Microencapsulated Kenaf Seed Oil
Authors: Ng Shy‐Kai , Jessie Li‐Ying Lau , Tan Chin‐Ping , Long Kamariah , Nyam Kar‐Lin 
Published: April 2013

AbstractIn order to improve the quality and protect against degradation, kenaf (Hibiscus cannabinus L.) seed oil was microencapsulated by using spray drying. The microencapsulated kenaf seed oil (MKSO) was then stored at 65 °C for 24 days, the changes of fatty acids and bioactive compounds were examined every six days. Bulk (unencapsulated) kenaf seed oil was used as a control and was compared to the MKSO. The fatty acids and phytosterols compositions were determined by using gas chromatography, while tocopherols and phenolic acids of microencapsulated kenaf seed oil were determined by using high performance liquid chromatography. The results showed that there was a significant decrease (p < 0.05) in bioactive compounds in kenaf seed oil while the bioactive compounds in MKSO were maintained in a stable condition upon accelerated storage. Microencapsulation was shown to protect kenaf seed oil against oxidation, as well as preventing the degradation and/or loss of bioactive compounds in kenaf seed oil.
Interventions for Substance Misuse following TBI: A Systematic Review
Authors: Bogner Jennifer , Corrigan John D. 
Published: April 2013

Objective: Review the literature to evaluate the evidence for effective treatment to mitigate substance misuse and substance use disorders (SUD) following traumatic brain injury (TBI).Design: Systematic review.Data source: Scopus.Study eligibility criteria: A study was considered eligible for review if (a) the intended population specifically included persons with TBI; (b) the experimental intervention targeted misuse of alcohol, illegal drugs or prescription drugs; (c) the intervention was compared to the standard of care, control or another intervention; (d) the outcomes under study included substance use or misuse; and (e) the study design was a controlled trial.Results: Six studies were identified that met the inclusion criteria. Three studies were conducted during the acute phase of recovery using brief interventions, while the remaining three were conducted with individuals in the post-acute phase (usually several years post-injury) using more intensive treatment. All studies were found to be vulnerable to bias due to methodological weaknesses.Conclusions: While firm conclusions could not be drawn from the results of the studies, each study provided important information about the challenges to conducting SUD intervention trials with persons with TBI. The choices researchers will have to make to address these challenges are delineated.
Chondroperichondrial clip myringoplasty: a new technique for closure of tympanic membrane perforations
Authors: Ahmed S , Raza N , Ullah S , Shabbir A 
Published: April 2013

AbstractObjective:This study aimed to evaluate the feasibility and efficacy of the recently described chondroperichondrial clip myringoplasty technique, and make comparisons with conventional myringoplasty techniques.Methods:The study comprised a select group of patients with chronic otitis media (mucosal disease only), with central tympanic membrane perforations affecting less than 50 per cent of the pars tensa, and an air–bone gap below 35 dB. A modified custom-made cartilage perichondrial graft was placed using the recently described ‘clip’ technique.Results:The graft success rate was 91.3 per cent. Post-operatively, the air–bone gap was within 10 dB in 52 per cent of cases and within 10–20 dB in 48 per cent of cases. There were few minor complications.Conclusion:Chondroperichondrial clip myringoplasty can be considered as an alternative minimally invasive technique for the repair of select cases of tympanic membrane perforations. This technique, which showed impressive results, was associated with minimum morbidity and reduced operative time.
Proximity to animal or crop operations may be associated with de novo daptomycin-non-susceptible Enterococcus infection
Authors: KELESIDIS T. , CHOW A. L. 
Published: April 2013

SUMMARYDaptomycin-non-susceptible enterococci (DNSE) are emerging pathogens. We have previously reported de novo DNSE isolates in patients with agricultural activities and exposure to livestock. We studied the geographical distribution of the residencies of 34 patients with DNSE infections described in a tertiary centre over a 5-year period in an effort to explore the association between patients’ residential locations and agricultural and farm lands. Nine patients had no prior exposure to daptomycin (de novo) and seven of these lived in areas with animal or crop operations. Of those living near an animal or crop operation, the mean number of operations in the proximity of the residence of patients with daptomycin-exposed DNSE was 13·8 (range 1–67) compared to 98·6 (3–529) for those patients with de novo DNSE (P = 0·0486). These data are consistent with previous reports that the transport of daptomycin resistance genes between animals and humans may be a possible mechanism for development of de novo daptomycin resistance in enterococci.
Nanotechnology and challenges to international humanitarian law: a preliminary legal assessment
Authors: Nasu Hitoshi 
Published: April 2013

AbstractThe introduction of nanotechnology into our civil life and warfare is expected to influence the application and interpretation of the existing rules of international humanitarian law. This article examines the challenges posed to international humanitarian law by the widespread use of nanotechnology in light of four basic rules of international humanitarian law: (1) the obligation to ensure the legality of weapons; (2) distinction; (3) proportionality; and (4) precaution. It concludes by identifying three areas of concern, which arise from widespread use of nanotechnology, for the application of international humanitarian law.
Supporting Undergraduate Education with Realistic Laboratory Exercises and Research Experience
Authors: Myrick Christopher A , Underwood Zachary E , Kinzli Kristoph D 
Published: April 2013

Abstract
Higher education programs can offer hands-on experiences in the form of laboratory or field exercises, experiential learning, and undergraduate research opportunities to students, though at an increased cost in terms of financial, material, and personnel requirements. In a climate where institutions seek to streamline their dwindling budgets, it could be tempting to eliminate some of these programs to focus on more traditional classroom-based education. This outcome, if combined with the traits of the typical “millennial generation” student, raises the possibility that current and future student cohorts will lack practical experience in core areas. We argue that despite the challenges of garnering funding and institutional support, it is both possible and beneficial to provide undergraduates with the hands-on experiences, experiential learning, and exposure to research and management topics that enrich their education and better prepare them for entry-level positions or graduate school. We describe a multitiered approach for doing so and include examples from successful programs at Colorado State University and Florida Gulf Coast University.
RESUMEN
los programas de educación a nivel superior pueden ofrecer contacto directo con la práctica en forma de ejercicios de campo o laboratorio, aprendizaje por experiencia, y oportunidades de investigación para estudiantes no graduados, sin embargo esto se ha logrado a un costo creciente en términos de recursos humanos, materiales y financieros. En un clima en el que las instituciones buscan optimizar sus magros presupuestos, pudiera resultar atractivo la eliminación de algunos de estos programas y enfocarse en una educación más tradicional en las aulas. Este resultado, si se combinase con los atributos del típico estudiante de la “generación del milenio”, aumentaría la posibilidad de que las cohortes de estudiantes del presente y del futuro adolezcan de una experiencia práctica en áreas críticas. Se argumenta que a pesar de los retos de encontrar fondos y apoyo institucional, es posible y también benéfico darles a los estudiantes de nivel superior experiencias directas, aprendizaje por experiencia y contacto con investigación sobre tópicos de manejo, enriqueciendo su educación y preparándolos mejor para que opten por un puesto básico o por un posgrado. Para lograr esto, aquí se describe un enfoque multi-niveles y se incluyen ejemplos de programas exitosos en la Universidad del Estado de Colorado y en la Universidad de la Costa Oeste de Florida.
Effects of hydroxy‐delta‐5‐steroid dehydrogenase, 3 beta‐ and steroid delta‐isomerase 1 polymorphisms on fat androstenone level and gene expression in Duroc pigs
Authors: Kim J. M. , Ahn J. H. , Lim K. S. , Lee E. A. , Chun T. , Hong K. C. 
Published: April 2013

SummaryA high level of androstenone in porcine adipose tissue is a major factor contributing to boar taint. Porcine hydroxy‐delta‐5‐steroid dehydrogenase, 3 beta‐ and steroid delta‐isomerase 1 (3β‐HSD, also known as HSD3B1) plays a key role in the hepatic metabolism that catalyzes androstenone to β‐androstenol. Therefore, 3β‐HSD is a candidate gene for boar taint. This study aimed to investigate functional 3β‐HSD polymorphisms in Duroc pigs. We found eight single nucleotide polymorphisms (SNPs) in the full‐length porcine 3β‐HSD. Four of the SNPs had restriction enzyme sites, and we genotyped them in 147 uncastrated male Duroc pigs using a polymerase chain reaction–restriction fragment length polymorphism method. Pigs with the GG genotype at the g.165262G>A locus (SNP5) had significantly lower androstenone levels than did those with other genotypes (P = 0.030). SNP5 also was associated with differences in 3β‐HSD mRNA levels: pigs with the GG genotype had higher levels than those with other genotypes (P = 0.019). The SNP5 polymorphism could affect the hepatic catabolism of androstenone and consequently impact androstenone accumulation in the adipose tissue. Therefore, SNP5 in the 3β‐HSD of Duroc pigs could be a useful selective marker for decreasing boar taint.
Early recognition of growth abnormalities permitting early intervention
Authors: Haymond Morey , Kappelgaard Anne-Marie , Czernichow Paul , Biller Beverly MK , Takano Koji , Kiess Wieland ,   The participants in the global advisory panel meeting on the effects of growth hormone
Published: April 2013

AbstractNormal growth is a sign of good health. Monitoring for growth disturbances is fundamental to children's health care. Early detection and diagnosis of the causes of short stature allows management of underlying medical conditions, optimizing attainment of good health and normal adult height.ConclusionThis review summarizes currently available information on monitoring for short stature in children and conditions usually associated with short stature and summarizes the authors’ conclusions on the early recognition of growth disorders.