bluuebunny/crossref_metadata_2025 huggingface dataset:
A mutation in the canine gene encoding folliculin‐interacting protein 2 (FNIP2) associated with a unique disruption in spinal cord myelination
Authors: Pemberton Trevor J. , Choi Sunju , Mayer Joshua A. , Li Fang‐Yuan , Gokey Nolan , Svaren John , Safra Noa , Bannasch Danika L. , Sullivan Katrina , Breuhaus Babetta , Patel Pragna I. , Duncan Ian D.
Published: November 2013

Novel mutations in myelin and myelin‐associated genes have provided important information on oligodendrocytes and myelin and the effects of their disruption on the normal developmental process of myelination of the central nervous system (CNS). We report here a mutation in the folliculin‐interacting protein 2 (FNIP2) gene in the Weimaraner dog that results in hypomyelination of the brain and a tract‐specific myelin defect in the spinal cord. This myelination disruption results in a notable tremor syndrome from which affected dogs recover with time. In the peripheral tracts of the lateral and ventral columns of the spinal cord, there is a lack of mature oligodendrocytes. A genome‐wide association study of DNA from three groups of dogs mapped the gene to canine chromosome 15. Sequencing of all the genes in the candidate region identified a frameshift mutation in the FNIP2 gene that segregated with the phenotype. While the functional role of FNIP2 is not known, our data would suggest that production of truncated protein results in a delay or failure of maturation of a subpopulation of oligodendrocytes. GLIA 2014;62:39–51
Nbn gene inactivation in the CNS of mouse inhibits the myelinating ability of the mature cortical oligodendrocytes
Authors: Liu Bo , Chen Xin , Wang Zhao‐Qi , Tong Wei‐Min
Published: November 2013

Nijmegen Breakage Syndrome (NBS) is a recessive genetic disorder characterized by immunodeficiency, elevated sensitivity to ionizing radiation, chromosomal instability, microcephaly, and high predisposition to malignancies. Since the underlying molecular mechanisms of the NBS microcephaly are still obscure, thus our group previously inactivated the Nbn gene in the central nervous system (CNS) of mice by nestin‐Cre targeting gene system, and generated NbnCNS‐del mice. Interestingly, the newborn NbnCNS‐del mice exhibit obvious microcephaly, which is accompanied by severe ataxia and balance deficiency. In this study presented here, we report that Nbn‐deficiency induces the enhanced apoptosis of the mature oligodendrocytes at postnatal day 7, which further affects the myelination of the nerve fibers of cerebrum and corpus callosum.The distinct regulatory roles of Ataxia telangiectasia mutated (ATM) signaling and protein kinase B(Akt)/the mammalian target of Rapamycin (AKT/mTOR) signaling are responsible for the enhanced apoptosis of the Nbn‐deficient oligodendrocytes. In addition, a series of transcriptional factors including histonedeacetylase (HDAC), zinc finger protein 191 (ZFP‐191) and myelin sheath regulatory factor (MRF) play distinct roles in regulating the myelination of the Nbn‐deficient oligodendrocytes. Based on these results, it concludes that ATM‐Chk2‐P53‐P21 signaling pathway and the AKT/mTOR signaling pathway are both responsible for the enhanced apoptosis of the Nbn‐deficient oligodendrocytes. HDAC, ZFP‐191, and MRF are also involved in the pathogenesis of the hypomyelination of the Nbn‐deficient oligodendrocytes. GLIA 2014;62:133–144
Parsing pyrogenic polycyclic aromatic hydrocarbons: Forensic chemistry, receptor models, and source control policy
Authors: O'Reilly Kirk T , Pietari Jaana , Boehm Paul D
Published: November 2013

A realistic understanding of contaminant sources is required to set appropriate control policy. Forensic chemical methods can be powerful tools in source characterization and identification, but they require a multiple-lines-of-evidence approach. Atmospheric receptor models, such as the US Environmental Protection Agency (USEPA)'s chemical mass balance (CMB), are increasingly being used to evaluate sources of pyrogenic polycyclic aromatic hydrocarbons (PAHs) in sediments. This paper describes the assumptions underlying receptor models and discusses challenges in complying with these assumptions in practice. Given the variability within, and the similarity among, pyrogenic PAH source types, model outputs are sensitive to specific inputs, and parsing among some source types may not be possible. Although still useful for identifying potential sources, the technical specialist applying these methods must describe both the results and their inherent uncertainties in a way that is understandable to nontechnical policy makers. The authors present an example case study concerning an investigation of a class of parking-lot sealers as a significant source of PAHs in urban sediment. Principal component analysis is used to evaluate published CMB model inputs and outputs. Targeted analyses of 2 areas where bans have been implemented are included. The results do not support the claim that parking-lot sealers are a significant source of PAHs in urban sediments. Integr Environ Assess Manag 2014;10:279–285. © 2013 SETAC

Key Points

Receptor models can be useful tools for evaluating contaminant sources, but careful consideration of each model's underlying assumption is critical. These include that all potential sources have been identified and their chemical profiles are known and stable. Given the variability within and similarity among pyrogenic polycyclic aromatic hydrocarbons (PAH) source types, receptor models may not be able to accurately estimate their individual contributions. When used to support source control policy decisions, the inherent uncertainties in the results of receptor models must be described in a way that are understandable to nontechnical policy makers. In a case study, a multiple-lines-of-evidence evaluation did not support the receptor model based claim that parking-lot sealers are a significant source of PAHs in urban sediments.
Human Keloid Cell Characterization and Inhibition of Growth with Human Wharton's Jelly Stem Cell Extracts
Authors: Fong Chui‐Yee , Biswas Arijit , Subramanian Arjunan , Srinivasan Akshaya , Choolani Mahesh , Bongso Ariff
Published: November 2013

Keloids are firm rubbery growths that grow beyond the boundaries of human wounds and their treatment has met with limited success. Their properties and growth behavior have not been properly characterized and it has been suggested that a benign neoplastic stem cell‐like phenotype in an altered cytokine microenvironment drives their uncontrolled cell proliferation. Modification of the stem cell niche may be an attractive approach to its prevention. We studied the growth behavior, stemness, and tumorigenic characteristics of keloid cells in prolonged culture. Since human Wharton's jelly stem cells (hWJSCs) secrete high levels of cytokines and have anti‐tumorigenic properties we explored its role on the inhibition of keloid growth in vitro. Keloid cells grew readily in both adherent and sphere culture and expressed high levels of mesenchymal CD and tumor‐associated fibroblast (TAF) markers up to passage 10. When they were exposed to repeat doses of hWJSC conditioned medium (hWJSC‐CM) and lysate (hWJSC‐CL) every 72 h up to 9 days their growth was inhibited with a reduction in CD and TAF marker expression. On Days 3, 6, and 9 treated keloid cells showed linear decreases in cell proliferation (BrdU), increases in Annexin V‐FITC and TUNEL‐positive cells, interruptions of the cell cycle and inhibition of migration in scratch‐wound assays. Immunocytochemistry and qRT‐PCR confirmed a significant downregulation of TAF and anti‐apoptotic‐related gene (SURVIVIN) expression and upregulation of autophagy‐related (BAX, ATG5, ATG7, BECLIN‐1) gene expression. The results suggest that hWJSCs or molecules secreted by them may be of therapeutic value in the treatment of keloids. J. Cell. Biochem. 115: 826–838, 2014. © 2013 Wiley Periodicals, Inc.
The circadian schedule for childhood acute lymphoblastic leukemia maintenance therapy does not influence event‐free survival in the NOPHO ALL92 protocol
Authors: Clemmensen Kim K.B. , Christensen Regitse H. , Shabaneh Diana N. , Harila‐Saari Arja , Heyman Mats , Jonsson Olafur G. , Wesenberg Finn , Rosthøj Susanne , Schmiegelow Kjeld ,   On behalf of the Nordic Society of Pediatric Hematology, Oncology (NOPHO)
Published: November 2013

Background

The event‐free survival of childhood acute lymphoblastic leukemia (ALL) has been reported to be superior when oral methotrexate (MTX) and 6‐mercaptopurine (6MP) maintenance therapy (MT) is administered in the evening compared to the morning.

Procedure

In the ALL92 MT study we prospectively registered the intake of MTX/6MP. The registration was done when blood samples for erythrocyte MTX/6MP metabolite measurements were collected, and referred to the time of intake in the period since last registration. Nine thousand one hundred ninety‐five registrations in total. The administration of MTX/6MP was scored as morning, midday, or evening.

Results

Of 532 patients, 296 took their medication consistently in the evening, 129 in the evening 50.0–99.9% of the time, and 101 in the evening <50% of the time, six did not have any registrations. The circadian schedule did not differ significantly by age, sex, MTX/6MP doses, and average absolute neutrophil counts. The circadian schedule groups did differ on risk groups (P = 0.003) with fewer HR patients in the 50–99.9% group, and there was a negative correlation between percentage of time on evening schedule and average WBC (Spearman's rho −0.15;P = 0.0004). Average WBC was not associated with relapse on ALL92. In a Cox multivariate model the circadian schedule of MTX/6MP was not of prognostic significance for the risk of relapse, and the 10‐year cumulative relapse risk was below 20% in all groups.

Conclusion

An evening schedule may still be recommended based on the previous publications, but in this study morning administration of MTX and 6MP does not seem to impact EFS. Pediatr Blood Cancer 2014;61:653–658. © 2013 Wiley Periodicals, Inc.
An improved in‐gel digestion method for efficient identification of protein and glycosylation analysis of glycoproteins using guanidine hydrochloride
Authors: Takakura Daisuke , Hashii Noritaka , Kawasaki Nana
Published: November 2013

In‐gel digestion followed by LC/MS/MS is widely used for the identification of trace amounts of proteins and for the site‐specific glycosylation analysis of glycoproteins in cells and tissues. A major limitation of this technique is the difficulty in acquiring reliable mass spectra for peptides present in minute quantities and glycopeptides with high heterogeneity and poor hydrophobicity. It is considered that the SDS used in electrophoresis can interact with proteins noncovalently and impede the ionization of peptides/glycopeptides. In this study, we report an improved in‐gel digestion method to acquire reliable mass spectra of a trace amount of peptides/glycopeptides. A key innovation of our improved method is the use of guanidine hydrochloride, which forms complexes with the residual SDS molecules in the sample. The precipitation and removal of SDS by addition of the guanidine hydrochloride was successful in improving the S/N of peptides/glycopeptides in mass spectra and acquiring a more comprehensive MS/MS data set for the various glycoforms of each glycopeptide.
ApoA‐I mutations, L202P and K131del, in HDL from heterozygotes with low HDL‐C
Authors: Ljunggren Stefan , Levels Johannes H. M. , Turkina Maria V. , Sundberg Sofie , Bochem Andrea E. , Hovingh Kees , Holleboom Adriaan G. , Lindahl Mats , Kuivenhoven Jan Albert , Karlsson Helen
Published: November 2013

Purpose

Mutations in apolipoprotein A‐I (apoA‐I) may affect plasma high‐density lipoprotein (HDL) cholesterol levels and the risk for cardiovascular disease but little is known about the presence and effects of circulating apoA‐I variants. This study investigates whether the apoA‐I mutations, apoA‐IL202P and apoA‐IK131del, are present on plasma HDL particles derived from heterozygote carriers and whether this is associated to changes in HDL protein composition.

Experimental design

Plasma HDL of heterozygotes for either apoA‐IL202P or apoA‐IK131del and family controls was isolated using ultracentrifugation. HDL proteins were separated by 2DE and analyzed by MS.

Results

ApoA‐I peptides containing apoA‐IL202P or apoA‐IK131del were identified in HDL from heterozygotes. The apoA‐IL202P mutant peptide was less abundant than wild‐type peptide while the apoA‐IK131del mutant peptide was more abundant than wild‐type peptide in the heterozygotes. Two‐dimensional gel electrophoresis analyses indicated that, compared to controls, HDL in apoA‐IL202P carriers contained less apoE and more zinc‐α‐2‐glycoprotein while HDL from the apoA‐IK131del heterozygotes contained more alpha‐1‐antitrypsin and transthyretin.

Conclusions and clinical relevance

Both apoA‐IL202P and apoA‐IK131del were identified in HDL. In heterozygotes, these mutations have markedly differential effects on the concentration of wild‐type apoA‐I in the circulation, as well as the HDL proteome, both of which might affect the clinical phenotype encountered in the heterozygous carriers.
Contact of ropes and orthotropic rough surfaces
Authors: Konyukhov Alexander
Published: November 2013

Contact between arbitrary curved ropes and arbitrary curved rough orthotropic surfaces has been revised from the geometrical point of view. Variational equations for the equilibrium of ropes on orthotropic rough surfaces are derived, first, using the consistent variational inclusion of frictional contact constraints via Karush‐Kuhn‐Tucker conditions expressed in Darboux basis. Then, the systems of differential equations are derived for both statics and dynamics of ropes on a rough surface depending on the sticking‐sliding condition for orthotropic Coulomb's friction. Three criteria are found to be fulfilled during the static equilibrium of a rope on a rough surface: “no separation”, condition for dragging coefficient of friction and inequality for tangential forces at the end of the rope. The limit tangential loads still preserve the famous “Euler view” T = T0e± ω s for the curves and surfaces of constant curvature. It is shown that the curve of the maximum tension of a rough orthotropic surface is geodesic. Equations of motion are derived in the case if the sliding criteria is fulfilled and there is “no separation”. Various cases possessing analytical solutions of the derived system, including Euler case and a spiral rope on a cylinder are shown as examples of application of the derived theory.
Enhanced expression of endoinulinase from Aspergillus niger by codon optimization in Pichia pastoris and its application in inulooligosaccharide production
Authors: He Miao , Wu Dan , Wu Jing , Chen Jian
Published: November 2013

In the present study, the endoinulinase gene (EnInu) from Aspergillus niger CICIM F0620 was optimized according to the codon usage of Pichia pastoris and both the native and the optimized gene were expressed in P. pastoris. Use of the optimized gene resulted in the secretion of recombinant endoinulinase activity that reached 1,349 U ml−1, 4.18 times that observed using the native gene. This is the highest endoinulinase activity reported to date. The recombinant enzyme was optimally active at pH 6.0 and 60 °C. Moreover, inulooligosaccharides production from inulin was studied using the recombinant enzyme produced from the optimized gene. After 8 h under optimal conditions, which included 400 g l−1 inulin, an enzyme concentration of 40 U g−1 substrate, 50 °C and pH 6.0, the inulooligosaccharide yield was 91 %. The high substrate concentration and short reaction time described here should reduce production costs distinctly, compared with the conditions used in previous studies. Thus, this study may provide the basis for the industrial use of this recombinant endoinulinase for the production of inulooligosaccharides.
Genomics-enabled discovery of phosphonate natural products and their biosynthetic pathways
Authors: Ju Kou-San , Doroghazi James R , Metcalf William W
Published: November 2013

Phosphonate natural products have proven to be a rich source of useful pharmaceutical, agricultural, and biotechnology products, whereas study of their biosynthetic pathways has revealed numerous intriguing enzymes that catalyze unprecedented biochemistry. Here we review the history of phosphonate natural product discovery, highlighting technological advances that have played a key role in the recent advances in their discovery. Central to these developments has been the application of genomics, which allowed discovery and development of a global phosphonate metabolic framework to guide research efforts. This framework suggests that the future of phosphonate natural products remains bright, with many new compounds and pathways yet to be discovered.
Stripe rust resistance and genes in Chinese wheat cultivars and breeding lines
Authors: Zeng Qing-Dong , Han De-Jun , Wang Qi-Lin , Yuan Feng-Ping , Wu Jian-Hui , Zhang Li , Wang Xiao-Jie , Huang Li-Li , Chen Xian-Ming , Kang Zhen-Sheng
Published: November 2013

Stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most important diseases on wheat in China. To assess resistance in wheat cultivars and breeding lines in China, 330 leading cultivars and 164 advanced breeding lines were evaluated with stripe rust. In the greenhouse tests, seedlings of the entries were inoculated separately with several Pst pathotypes. In the field tests, the entries were evaluated for stripe rust resistance in Yangling, Shaanxi Province artificially inoculated and in Tianshui, Gansu Province under natural infection of Pst. The oversummering/wintering and spring epidemic zones of resistance genes were postulated using molecular markers for Yr5, Yr9, Yr10, Yr15, Yr17, Yr18, and Yr26, in combination with resistance spectra. Out of the 494 wheat entries, 16 (3.24 %) entries had all-stage resistance (ASR) in all race tests, 99 (20.04 %) had adult-plant resistance (APR), 28 (5.67 %) were considered to have slow-rusting (SR), and 351 (71.05 %) were susceptible to one or more races in both seedling and adult-plant stages. Advanced breeding lines had a higher percentage (37.2 %) of resistant entries (The sum of ASR, APR and SR) than leading cultivars (24.85 %). Among the epidemic regions, southern Gansu had a higher percentage of resistant entries than any other regions. Based on stripe rust reactions and molecular markers, two cultivars were found to possibly have Yr5 while no entries have Yr10 or Yr15. Resistance genes Yr9, Yr17, Yr18, and Yr26 were found in 134 (29.4 %), 45 (9.1 %), 10 (2 %), and 15 (3 %) entries, respectively.
Large‐scale features affect spatial variation in seed dispersal by birds in juniper woodlands
Authors: Tellería José L. , Carrascal Luis M. , Santos Tomás
Published: November 2013

Fruit–frugivore interactions have received great attention from evolutionary, ecological and applied perspectives. However, despite the fact that large‐scale approaches may offer new insights on fruit–frugivore interactions, little work has been devoted to exploring the factors shaping large‐scale variation of seed dispersal. This paper studies the spatial variation in seeds regurgitated within pellets by wintering thrushes (genusTurdus) in a set of 26 Spanish juniper (Juniperus thurifera) woodlands scattered along a latitudinal gradient during two winters of contrasting cone and bird abundance. It explicitly explores whether pellet rain variation among woodlands was related to changes in vegetation cover, temperature, day length duration and bird abundance. Top regression models in the Akaike information criterion framework explained 34 % and 70 % of variance in pellet numbers in low and high crop and bird abundance years, respectively. In both winters, the spatial variation in pellets correlated to thrush abundance and day length duration. Pellet abundance linked to cone distribution only in the year of high crop, in which many migratory, extra‐Iberian thrushes arrived to exploit the resource. Strong dependence of seed dispersion on large‐scale features affecting bird numbers (e.g. the arrival of extra‐Iberian migratory birds) and feeding behaviour (e.g. latitudinal variation in day length duration) suggests a primary role for variables acting at large scale on this mutualistic interaction.
Differential Expressions of G0/G1 Switch Gene 2 and Comparative Gene Identification‐58 are Associated with Fat Content in Bovine Muscle
Authors: Ahn Jinsoo , Li Xiang , Choi Young Min , Shin Sangsu , Oh Shin‐Ae , Suh Yeunsu , Nguyen Trang Hoa , Baik Myunggi , Hwang Seongsoo , Lee Kichoon
Published: November 2013

Regulation of lipolysis in muscle is a potential mechanism affecting marbling in beef carcasses and fat accumulation in muscles of humans, which is a known risk factor for type 2 diabetes. Adipose triglyceride lipase‐mediated lipolysis is inhibited by G0/G1 switch gene 2 (G0S2) and co‐activated by comparative gene identification‐58 (CGI‐58). In this study, bovine G0S2 and CGI‐58 were sequenced, and expressions of these genes were compared among various tissues and in muscles between bulls and steers with different degrees of marbling. The protein coding sequences of bovine G0S2 and CGI‐58 revealed breed‐specific SNPs, causing two amino acid variations for each protein. Bovine CGI‐58 mRNA showed two isoforms from alternative splicing. The G0S2 gene was preferentially expressed in fat and, to a lesser degree, in the liver; whereas, CGI‐58 was highly expressed in the muscle and fat (P < 0.05), suggesting their association with lipid metabolism in those tissues. The longissimus dorsi muscle (LM) of steers showed higher FABP4, G0S2 and CGI‐58 mRNA expression levels than the LM of bulls, implying the roles of those genes more in marbling of steers than in that of bulls. The G0S2 expression was markedly higher in the intramuscular fat (IMF) (P < 0.001); whereas, the CGI‐58 expression was significantly higher in the pure muscle portion of the LM of steers (P < 0.01), suggesting that G0S2 and CGI‐58 may regulate IMF and intramyocellular triglycerides, respectively. Taken together, our data suggest that G0S2 and CGI‐58 are associated with fat content in bovine species.
Hydrophobic, mechanical, and tribological properties of fluorine incorporated hydrogenated fullerene-like carbon films
Authors: Qiang Li , Zhang Bin , Gao Kaixiong , Gong Zhenbin , Zhang Junyan
Published: November 2013

Fluorine-incorporated hydrogenated fullerene-like nanostructure amorphous carbon films (F-FLC) were synthesized by employing the direct current plasma enhanced chemical vapor deposition (dc-PECVD) technique using a mixture of methane (CH4), tetra-fluoromethane (CF4), and hydrogen (H2) as the working gases. The effect of the fluorine content on the bonding structure, surface roughness, hydrophobic, mechanical, and tribological properties of the films was systematically investigated using Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), Raman analysis, atomic force microscope (AFM), contact angle goniometer, nano-indenter, and reciprocating ball-on-disc tester, respectively. The fluorine content in the films increased from 0 to 2.1 at.% as the CF4 gas flow ratio increased from 0 to 3 sccm, and incorporated fluorine atoms existed in the form of C-F
X
(X = 1, 2, 3) bonds in the film. The fullerene nanostructure embedded in the hydrogenated amorphous carbon films was confirmed by Raman analysis. The water contact angle was significantly increased because of fluorine doping, which indicates that the hydrophobicity of the carbon films could be adjusted to some extent by the fluorine doping. The hardness and elastic modulus of the films remained relatively high (22 GPa) as the fluorine content increased. Furthermore, the friction coefficient of the carbon films was significantly reduced and the wear resistance was enhanced by fluorine doping.
The neurobiology of autism spectrum disorders
Authors: Parellada M. , Penzol M.J. , Pina L. , Moreno C. , González-Vioque E. , Zalsman G. , Arango C.
Published: November 2013

Data is progressively and robustly accumulating regarding the biological basis of autism. Autism spectrum disorders (ASD) are currently considered a group of neurodevelopmental disorders with onset very early in life and a complex, heterogeneous, multifactorial aetiology. A comprehensive search of the last five years of the Medline database was conducted in order to summarize recent evidence on the neurobiological bases of autism. The main findings on genetic influence, neuropathology, neurostructure and brain networks are summarized. In addition, findings from peripheral samples of subjects with autism and animal models, which show immune, oxidative, mitochondrial dysregulations, are reported. Then, other biomarkers from very different systems associated with autism are reported. Finally, an attempt is made to try and integrate the available evidence, which points to a oligogenetic, multifactorial aetiology that converges in an aberrant micro-organization of the cortex, with abnormal functioning of the synapses and abnormalities in very general physiological pathways (such as inflammatory, immune and redox systems).
Up‐regulation of alpha‐smooth muscle actin in cardiomyocytes from non‐hypertrophic and non‐failing transgenic mouse hearts expressing N‐terminal truncated cardiac troponin I
Authors: Kern Stephanie , Feng Han-Zhong , Wei Hongguang , Cala Steven , Jin J.-P.
Published: November 2013

We previously reported that a restrictive N‐terminal truncation of cardiac troponin I (cTnI‐ND) is up‐regulated in the heart in adaptation to hemodynamic stresses. Over‐expression of cTnI‐ND in the hearts of transgenic mice revealed functional benefits such as increased relaxation and myocardial compliance. In the present study, we investigated the subsequent effect on myocardial remodeling. The alpha‐smooth muscle actin (α‐SMA) isoform is normally expressed in differentiating cardiomyocytes and is a marker for myocardial hypertrophy in adult hearts. Our results show that in cTnI‐ND transgenic mice of between 2 and 3 months of age (young adults), a significant level of α‐SMA is expressed in the heart as compared with wild‐type animals. Although blood vessel density was increased in the cTnI‐ND heart, the mass of smooth muscle tissue did not correlate with the increased level of α‐SMA. Instead, immunocytochemical staining and Western blotting of protein extracts from isolated cardiomyocytes identified cardiomyocytes as the source of increased α‐SMA in cTnI‐ND hearts. We further found that while a portion of the up‐regulated α‐SMA protein was incorporated into the sarcomeric thin filaments, the majority of SMA protein was found outside of myofibrils. This distribution pattern suggests dual functions for the up‐regulated α‐SMA as both a contractile component to affect contractility and as possible effector of early remodeling in non‐hypertrophic, non‐failing cTnI‐ND hearts.
Reproductive performance after conservative surgical treatment of postpartum hemorrhage
Authors: Rasheed Salah M. , Amin Magdy M. , Abd Ellah Ahmed H. , Abo Elhassan Ahmed M. , El Zahry Mazen A. , Wahab Hala A.
Published: November 2013

Objective

To evaluate the impact of bilateral internal iliac artery ligation (BIL), bilateral uterine artery ligation (BUAL), step‐wise uterine devascularization (SWUD), and B‐Lynch on infertility, ovarian reserve, and pregnancy outcome.

Methods

The study included 168 infertile or pregnant patients—recruited at outpatient clinics in Egypt—who had previously undergone uterine‐sparing surgery (BIL [group I], n = 59; SWUD [group II], n = 65); BUAL [group III], n = 2; and B‐Lynch [group IV], n = 42). One‐way analysis of variance was used to compare the prevalence of infertility, the status of ovarian reserve, and the prevalence and type of relevant maternal and/or fetal obstetric complications between the groups.

Results

Groups II and IV had the highest prevalences of infertility. The ovarian reserve was significantly lower in group II. Unexplained infertility was the predominant cause of infertility in group I, anovulation and premature ovarian failure in group II, and endometriosis and intrauterine adhesions in group IV. The frequency of obstetric complications, particularly placenta previa and preterm labor, was high in group IV.

Conclusion

Of the 4 procedures, BIL had the least deleterious effect on reproductive performance; SWUD increased the risk of premature ovarian failure, and B‐Lynch increased the risks of endometriosis, intrauterine adhesions, placenta previa, and preterm labor.
Consumer Decision-making Processes in Mobile Viral Marketing Campaigns
Authors: Pescher Christian , Reichhart Philipp , Spann Martin
Published: November 2013

The high penetration of cell phones in today's global environment offers a wide range of promising mobile marketing activities, including mobile viral marketing campaigns. However, the success of these campaigns, which remains unexplored, depends on the consumers’ willingness to actively forward the advertisements that they receive to acquaintances, e.g., to make mobile referrals. Therefore, it is important to identify and understand the factors that influence consumer referral behavior via mobile devices. The authors analyze a three-stage model of consumer referral behavior via mobile devices in a field study of a firm-created mobile viral marketing campaign. The findings suggest that consumers who place high importance on the purposive value and entertainment value of a message are likely to enter the interest and referral stages. Accounting for consumers’ egocentric social networks, we find that tie strength has a negative influence on the reading and decision to refer stages and that degree centrality has no influence on the decision-making process.
A model equation for the joint distribution of the length and velocity difference of streamline segments in turbulent flows
Authors: Schaefer P. , Gampert M. , Peters N.
Published: November 2013

Streamlines recently received attention as natural geometries of turbulent flow fields. Similar to dissipation elements in scalar fields, streamlines are segmented into smaller subunits based on local extreme points of the absolute value of the velocity field u along the streamline coordinate s, i.e., points where the projected gradient in streamline direction us = 0. Then, streamline segments are parameterized using their arclength l between two neighboring extrema and the velocity difference Δ at the extrema. Both parameters are statistical variables and streamline segments are characterized by the joint probability density function (jpdf) P(l, Δ). Based on a previously formulated model for the marginal pdf of the arclength, P(l), which contains terms that account for slow changes as well as fast changes of streamline segments, a model for the jpdf is formulated. The jpdf's, when normalized with the mean length, lm, and the standard deviation of the velocity difference σ, obtained from two different direct numerical simulations (DNS) cases of homogeneous isotropic decaying and forced turbulence at Taylor based Reynolds number of Reλ = 116 and Reλ = 206, respectively, turn out to be almost Reynolds number independent. The steady model solution is compared with the normalized jpdf's obtained from DNS and it is found to be in good agreement. Special attention is paid to the intrinsic asymmetry of the jpdf with respect to the mean length of positive and negative streamline segments, where due to the kinematic stretching of positive segments and compression of negative ones, the mean length of positive segments turns out to be larger than the mean length of negative ones. This feature is reproduced by the model and the ratio of the two length scales, which turns out to be an almost Reynolds number independent, dimensionless quantity, is well reproduced. Finally, a relation between the kinetic asymmetry of streamline segments and the dynamic asymmetry of the pdf of longitudinal velocity gradients in turbulent flows, which manifests itself in a negative velocity gradient skewness, is established and it is theoretically shown that negative streamline segments are only smaller than positive ones, if the gradient is negatively skewed.
On the ground state calculation of a many-body system using a self-consistent basis and quasi-Monte Carlo: An application to water hexamer
Authors: Georgescu Ionuţ , Jitomirskaya Svetlana , Mandelshtam Vladimir A.
Published: November 2013

Given a quantum many-body system, the Self-Consistent Phonons (SCP) method provides an optimal harmonic approximation by minimizing the free energy. In particular, the SCP estimate for the vibrational ground state (zero temperature) appears to be surprisingly accurate. We explore the possibility of going beyond the SCP approximation by considering the system Hamiltonian evaluated in the harmonic eigenbasis of the SCP Hamiltonian. It appears that the SCP ground state is already uncoupled to all singly- and doubly-excited basis functions. So, in order to improve the SCP result at least triply-excited states must be included, which then reduces the error in the ground state estimate substantially. For a multidimensional system two numerical challenges arise, namely, evaluation of the potential energy matrix elements in the harmonic basis, and handling and diagonalizing the resulting Hamiltonian matrix, whose size grows rapidly with the dimensionality of the system. Using the example of water hexamer we demonstrate that such calculation is feasible, i.e., constructing and diagonalizing the Hamiltonian matrix in a triply-excited SCP basis, without any additional assumptions or approximations. Our results indicate particularly that the ground state energy differences between different isomers (e.g., cage and prism) of water hexamer are already quite accurate within the SCP approximation.
Hydrogen evolution from water through metal sulfide reactions
Authors: Saha Arjun , Raghavachari Krishnan
Published: November 2013

Transition metal sulfides play an important catalytic role in many chemical reactions. In this work, we have conducted a careful computational study of the structures, electronic states, and reactivity of metal sulfide cluster anions M2SX− (M = Mo and W, X = 4–6) using density functional theory. Detailed structural analysis shows that these metal sulfide anions have ground state isomers with two bridging sulfide bonds, notably different in some cases from the corresponding oxides with the same stoichiometry. The chemical reactivity of these metal sulfide anions with water has also been carried out. After a thorough search on the reactive potential energy surface, we propose several competitive, energetically favorable, reaction pathways that lead to the evolution of hydrogen. Selectivity in the initial water addition and subsequent hydrogen migration are found to be the key steps in all the proposed reaction channels. Initial adsorption of water is most favored involving a terminal metal sulfur bond in Mo2S4− isomers whereas the most preferred orientation for water addition involves a bridging metal sulfur bond in the case of W2S4− and M2S5− isomers. In all the lowest energy H2 elimination steps, the interacting hydrogen atoms involve a metal hydride and a metal hydroxide (or thiol) group. We have also observed a higher energy reaction channel where the interacting hydrogen atoms in the H2 elimination step involve a thiol (–SH) and a hydroxyl (–OH) group. For all the reaction pathways, the Mo sulfide reactions involve a higher barrier than the corresponding W analogues. We observe for both metals that reactions of M2S4− and M2S5− clusters with water to liberate H2 are exothermic and involve modest free energy barriers. However, the reaction of water with M2S6− is highly endothermic with a considerable barrier due to saturation of the local bonding environment.
1-allyl-3-methylimidazolium chloride pretreatment of seaweed industrial waste for bioethanol conversion
Authors: Wang Jing , Wang Haoxi , Mou Haijin
Published: November 2013

Alginate industrial waste, that is, floating residue (FR) obtained from Laminaria japonica, was investigated in this study on saccharification for bioethanol conversion from cellulose. Pretreatment, as a key link but currently a bottleneck, was addressed by 1-allyl-3-methylimidazolium chloride (AMIMCl), which is considered a preferable pretreatment solvent form among various room temperature ionic liquids. Effects of AMIMCl pretreatment conditions were detected in moderate ranges of low energy consumption through single factor tests, incubation temperature, incubation time, and the solid-to-AMIMCl ratio (w/w), respectively. Further, the scanning electron microscopy and X-ray powder diffraction were used to study the alteration of structure and crystal form of FR after pretreatment. Meanwhile, it was shown that FR by AMIMCl pretreatment was capable of achieving a high glucose conversion rate with a lower content of cellobiase, which was in favor of the fermentation process. In the simultaneous saccharification and fermentation process, AMIMCl pretreatment could improve the bioethanol conversion rate to 91.60% in a shorter reaction time when compared with dilute sulfuric acid pretreatment. Thus, AMIMCl pretreatment has remarkable potential prospect for use as a new biotechnology technique in the marine biomass field.
Distributions of methyl group rotational barriers in polycrystalline organic solids
Authors: Beckmann Peter A. , Conn Kathleen G. , Mallory Clelia W. , Mallory Frank B. , Rheingold Arnold L. , Rotkina Lolita , Wang Xianlong
Published: November 2013

We bring together solid state 1H spin-lattice relaxation rate measurements, scanning electron microscopy, single crystal X-ray diffraction, and electronic structure calculations for two methyl substituted organic compounds to investigate methyl group (CH3) rotational dynamics in the solid state. Methyl group rotational barrier heights are computed using electronic structure calculations, both in isolated molecules and in molecular clusters mimicking a perfect single crystal environment. The calculations are performed on suitable clusters built from the X-ray diffraction studies. These calculations allow for an estimate of the intramolecular and the intermolecular contributions to the barrier heights. The 1H relaxation measurements, on the other hand, are performed with polycrystalline samples which have been investigated with scanning electron microscopy. The 1H relaxation measurements are best fitted with a distribution of activation energies for methyl group rotation and we propose, based on the scanning electron microscopy images, that this distribution arises from molecules near crystallite surfaces or near other crystal imperfections (vacancies, dislocations, etc.). An activation energy characterizing this distribution is compared with a barrier height determined from the electronic structure calculations and a consistent model for methyl group rotation is developed. The compounds are 1,6-dimethylphenanthrene and 1,8-dimethylphenanthrene and the methyl group barriers being discussed and compared are in the 2–12 kJ mol−1 range.
A Voronoï analysis of preferential concentration in a vertical channel flow
Authors: Nilsen Christopher , Andersson Helge I. , Zhao Lihao
Published: November 2013

We use three-dimensional Voronoï analysis and results from a direct numerical simulation to study the preferential concentration of inertial particles in a vertical channel flow at Reynolds number 395. By comparing results in upward and downward flows with results from a channel flow without gravity, we are able to determine how gravity affects the particle clustering. Gravity increases the drift of particles towards the walls in an upward flow, while in the downward flow more particles are transported to the centre of the channel. For particles with Stokes number 100, the mean wall-normal particle velocity is positive in the entire core region. A significant increase in variance of the Voronoï probability distribution in the core region is observed in downward flow for Stokes numbers 30 and 100, indicating stronger particle clustering than in upward flow or flow without gravity. The increased clustering in the downward flow is believed to be partly caused by the reversed wall-normal drift assisting in bringing particles close together in the centre of the channel.
Vortices catapult droplets in atomization
Authors: Jerome J. John Soundar , Marty Sylvain , Matas Jean-Philippe , Zaleski Stéphane , Hoepffner Jérôme
Published: November 2013

A droplet ejection mechanism in planar two-phase mixing layers is examined. Any disturbance on the gas-liquid interface grows into a Kelvin-Helmholtz wave, and the wave crest forms a thin liquid film that flaps as the wave grows downstream. Increasing the gas speed, it is observed that the film breaks up into droplets which are eventually thrown into the gas stream at large angles. In a flow where most of the momentum is in the horizontal direction, it is surprising to observe these large ejection angles. Our experiments and simulations show that a recirculation region grows downstream of the wave and leads to vortex shedding similar to the wake of a backward-facing step. The ejection mechanism results from the interaction between the liquid film and the vortex shedding sequence: a recirculation zone appears in the wake of the wave and a liquid film emerges from the wave crest; the recirculation region detaches into a vortex and the gas flow over the wave momentarily reattaches due to the departure of the vortex; this reattached flow pushes the liquid film down; by now, a new recirculation vortex is being created in the wake of the wave—just where the liquid film is now located; the liquid film is blown up from below by the newly formed recirculation vortex in a manner similar to a bag-breakup event; the resulting droplets are catapulted by the recirculation vortex.
On an intrinsic approach of the guiding-center anholonomy and gyro-gauge arbitrariness
Authors: de Guillebon L. , Vittot M.
Published: November 2013

In guiding center theory, the standard gyro-angle coordinate is associated with gyro-gauge dependence, the global existence problem for unit vectors perpendicular to the magnetic field, and the notion of anholonomy, which is the failure of the gyro-angle to return to its original value after being transported around a loop in configuration space. We analyse these three intriguing topics through the lens of a recently proposed, global, gauge-independent gyro-angle. This coordinate is constrained and therefore necessitates the use of a covariant derivative. It also highlights the intrinsic meaning and physical content of gyro-gauge freedom and anholonomy. There are, in fact, many possible covariant derivatives compatible with the intrinsic gyro-angle, and each possibility corresponds to a different notion of gyro-angle transport. This observation sheds new light on Littlejohn's notion of gyro-angle transport and suggests a new derivation of the recently discovered global existence condition for unit vectors perpendicular to the magnetic field. We also discuss the relationship between Cartesian position-momentum coordinates and the intrinsic gyro-angle.
Research of an electromagnetically actuated spark gap switch
Authors: Zhang Tianyang , Chen Dongqun , Liu Jinliang , Wang Yuwei , Qiu Yongfeng
Published: November 2013

As an important part of pulsed power systems, high-voltage and high-current triggered spark gap switch and its trigger system are expected to achieve a compact structure. In this paper, a high-voltage, high-current, and compact electromagnetically actuated spark gap switch is put forward, and it can be applied as a part of an intense electron-beam accelerator (IEBA). A 24 V DC power supply is used to trigger the switch. The characteristics of the switch were measured for N2 when the gas pressure is 0.10–0.30 MPa. The experimental results showed that the voltage/pressure (V/p) curve of the switch was linear relationship. The operating ranges of the switch were 21%–96%, 21%–95%, 21%–95%, 19%–95%, 17%–95%, and 16%–96% of the switch's self-breakdown voltage when the gas pressures were 0.10, 0.14, 0.18, 0.22, 0.26, and 0.30 MPa, respectively. The switch and its trigger system worked steadily and reliably with a peak voltage of 30 kV, a peak current of 60 kA in the IEBA when the pressure of N2 in the switch was 0.30 MPa.
Reduction of defect formation in amorphous indium-gallium-zinc-oxide thin film transistors by N2O plasma treatment
Authors: Jhu Jhe-Ciou , Chang Ting-Chang , Chang Geng-Wei , Tai Ya-Hsiang , Tsai Wu-Wei , Chiang Wen-Jen , Yan Jing-Yi
Published: November 2013

An abnormal sub-threshold leakage current is observed at high temperature in amorphous indium-gallium-zinc-oxide thin film transistors (a-IGZO TFTs). This phenomenon occurs due to a reduced number of defects in the device's a-IGZO active layer after the device has undergone N2O plasma treatment. Experimental verification shows that the N2O plasma treatment enhances the thin film bonding strength, thereby suppressing the formation of temperature-dependent holes, which are generated above 400 K by oxygen atoms leaving their original sites. The N2O plasma treatment devices have better stability performance than as-fabricated devices. The results suggest that the density of defects for a-IGZO TFTs with N2O plasma treatment is much lower than that in as-fabricated devices. The N2O plasma treatment repairs the defects and suppresses temperature-dependent sub-threshold leakage current.
Matrix isolation infrared spectroscopic and theoretical study of 1,1,1-trifluoro-2-chloroethane (HCFC-133a)
Authors: Rodrigues Gessenildo Pereira , Lucena Juracy Régis , Ventura Elizete , Andrade do Monte Silmar , Reva Igor , Fausto Rui
Published: November 2013

The molecular structure and infrared spectrum of the atmospheric pollutant 1,1,1-trifluoro-2-chloroethane (HCFC-133a; CF3CH2Cl) in the ground electronic state were characterized experimentally and theoretically. Excited state calculations (at the CASSCF, MR-CISD, and MR-CISD+Q levels) have also been performed in the range up to ∼9.8 eV. The theoretical calculations show the existence of one (staggered) conformer, which has been identified spectroscopically for the monomeric compound isolated in cryogenic (∼10 K) argon and xenon matrices. The observed infrared spectra of the matrix-isolated HCFC-133a were interpreted with the aid of MP2/aug-cc-pVTZ calculations and normal coordinate analysis, which allowed a detailed assignment of the observed spectra to be carried out, including identification of bands due to different isotopologues (35Cl and 37Cl containing molecules). The calculated energies of the several excited states along with the values of oscillator strengths and previous results obtained for CFCs and HCFCs suggest that the previously reported photolyses of the title compound at 147 and 123.6 nm [T. Ichimura, A. W. Kirk, and E. Tschuikow-Roux, J. Phys. Chem. 81, 1153 (1977)] are likely to be initiated in the n-4s and n-4p Rydberg states, respectively.