bluuebunny/crossref_metadata_2025_split huggingface dataset:
Arachidonic acid synthesis by glycerol‐grown Mortierella alpina
Authors: Dedyukhina Emiliya G. , Chistyakova Tatyana I. , Kamzolova Svetlana V. , Vinter Margarita V. , Vainshtein Mikhail B. 
Published: March 2012

AbstractMicrobiological production of physiologically active AA usually used carbohydrates as substrates. Recently, glycerol attracted attention as a promising renewable substrate for biotechnological industry. The effect of pure glycerol on the growth, lipid synthesis, and AA production by earlier selected Mortierella alpina strains LPM‐301 and NRRL‐A‐10995 was studied. It was shown that AA amount varied from 22–29 to 63–68% of lipid in dependence on the initial glycerol concentration in the medium. The transition from glycerol‐ to nitrogen limitation of the growth was accompanied by a reverse correlation between lipid content of biomass and AA level of lipid. Under selected optimal conditions (nitrogen limitation of fungal growth at glycerol concentrations of 75–81 g/L), AA production by 14‐day cultures reached 40–43% of lipid and 11–13% of biomass indicating that glycerol can be successfully used as a carbon substrate for AA production.Practical applications: AA has found wide application in medicine, pharmacology, diet, and infant nutrition as a precursor of several key eicosanoid hormones and pharmacologically active metabolites. It can also be used in agriculture as an elicitor of plant resistance to phytopathogens. Microbiological processes for AA production usually used carbohydrate substrates. Results of this study indicate that AA can be produced from glycerol, which is known as a promising renewable carbon substrate. Under selected optimal conditions (nitrogen limitation of fungal growth at glycerol concentrations of 75–81 g/L), AA production by Mortierella alpina strains LPM‐301 and NRRL‐A‐10995 reached 40–43% of lipid and 11–13% of biomass. These values are comparable with those obtained for carbohydrate‐grown Mortierella fungi.
Renewable linear alpha olefins by selective ethenolysis of decarboxylated unsaturated fatty acids
Authors: van der Klis Frits , Le Nôtre Jérôme , Blaauw Rolf , van Haveren Jacco , van Es Daan S. 
Published: March 2012

AbstractA two‐step concept for the production of linear alpha olefins from biomass is reported. As a starting material an internally unsaturated C17 alkene was used, which was obtained by the decarboxylation of oleic acid. Here, we report on the ethenolysis of this bio‐based product, using commercially available metathesis catalysts. The desired alpha olefin products, 1‐nonene and 1‐decene, were obtained in excellent yield (96%) and selectivity (96%).Practical applications: The two‐step conversion described in this contribution, starting from unsaturated fatty acids, provides a method for the production of industrially important linear alpha olefins. These valuable products are widely used as starting materials for the production of surfactants and polymers such as linear low density polyethylene (LLDPE).
Design and Development of Bioinspired Guanine‐Based Organic Catalyst for Asymmetric Catalysis
Authors: Suez Gal , Bloch Victoria , Nisnevich Gennady , Gandelman Mark 
Published: March 2012

AbstractDesign, preparation, and studies of a family of new organic catalysts are presented. The design of the catalysts is inspired by the ability of DNA nucleobases to develop precise and explicit hydrogen bonds. We have shown that this phenomenon can be used to create a useful organic catalyst that demonstrates a recognition pattern similar to those of common organic substrates. A selected bifunctional catalyst based on a guanine structure has been shown to catalyze the conjugate addition of 1,3‐dicarbonyl compounds to various nitroalkenes, providing the products in good yields and enantioselectivities.
Stereocontrol with Lithium Trimethylzincate toward Gibberellin Synthesis
Authors: Isobe Minoru , Chiang Ching‐Te , Tsao Kuo‐Wei , Cheng Chia‐Yi , Bruening Reimar 
Published: March 2012

AbstractSubstrate control in target‐oriented synthesis is generally important in establishing the required stereogenic center rather than reagent control. During the course of the total synthesis toward Gibberellin A3 (1), a model compound (21) as the A‐ring of 1 was accomplished in five overall steps with an overall yield of 15 %, starting from furfural through conjugate addition of lithium trimethylzincate to oxabicyclo[2.2.1]heptadienedicarboxylic ester (2) as the key step. Relative to more common lithium dimethylcuprate or aluminum reagents, this zincate complex showed a complete selectivity with higher reactivity than with other simple enone compounds. The incoming methyl group was 100 % selective from the ring oxygen side of 2, and the enolate intermediate can be protonated stereoselectivly without the bridge‐oxygen‐ring opening.
Nrf2 links epidermal barrier function with antioxidant defense
Authors: Schäfer Matthias , Farwanah Hany , Willrodt Ann‐Helen , Huebner Aaron J. , Sandhoff Konrad , Roop Dennis , Hohl Daniel , Bloch Wilhelm , Werner Sabine 
Published: March 2012

AbstractThe skin provides an efficient permeability barrier and protects from microbial invasion and oxidative stress. Here, we show that these essential functions are linked through the Nrf2 transcription factor. To test the hypothesis that activation of Nrf2 provides skin protection under stress conditions, we determined the consequences of pharmacological or genetic activation of Nrf2 in keratinocytes. Surprisingly, mice with enhanced Nrf2 activity in keratinocytes developed epidermal thickening, hyperkeratosis and inflammation resembling lamellar ichthyosis. This resulted from upregulation of the cornified envelope proteins small proline‐rich proteins (Sprr) 2d and 2h and of secretory leukocyte peptidase inhibitor (Slpi), which we identified as novel Nrf2 targets in keratinocytes. Since Sprrs are potent scavengers of reactive oxygen species and since Slpi has antimicrobial activities, their upregulation contributes to Nrf2's protective function. However, it also caused corneocyte fragility and impaired desquamation, followed by alterations in the epidermal lipid barrier, inflammation and overexpression of mitogens that induced keratinocyte hyperproliferation. These results identify an unexpected role of Nrf2 in epidermal barrier function, which needs to be considered for pharmacological use of Nrf2 activators.→See accompanying article http://dx.doi.org/10.1002/emmm.201200223
‘Hearts and bones’: the ups and downs of ‘plasticity’ in stem cell biology
Authors: Bonfanti Paola , Barrandon Yann , Cossu Giulio 
Published: March 2012

AbstractMore than a decade ago, ‘plasticity’ suddenly became a ‘fashionable’ topic with overemphasized implications for regenerative medicine. The concept of ‘plasticity’ is supported by old transplantation work, at least for embryonic cells, and metaplasia is a classic example of plasticity observed in patients. Nevertheless, the publication of a series of papers showing rare conversion of a given cell type into another unrelated cell raised the possibility of using any unaffected tissue to create at will new cells to replace a different failing tissue or organ. This resulted in disingenuous interpretations and a reason not to fund anymore research on embryonic stem cells (ESc). Moreover, many papers on plasticity were difficult to reproduce and thus questioned; raising issues about plasticity as a technical artefact or a consequence of rare spontaneous cells fusion. More recently, reprogramming adult differentiated cells to a pluripotent state (iPS) became possible, and later, one type of differentiated cell could be directly reprogrammed into another (e.g. fibroblasts into neurons) without reverting to pluripotency. Although the latter results from different and more robust experimental protocols, these phenomena also exemplify ‘plasticity’. In this review, we want to place ‘plasticity’ in a historical perspective still taking into account ethical and political implications.
Monolithic Newton‐multigrid solution techniques for incompressible nonlinear flow models
Authors: Damanik H. , Hron J. , Ouazzi A. , Turek S. 
Published: March 2012

SUMMARYWe present special Newton‐multigrid techniques for stationary incompressible nonlinear flow models discretized by the high order LBB‐stable Q2P1 element pair. We treat the resulting nonlinear and the corresponding linear discrete systems by a fully coupled monolithic approach to maintain high accuracy and robustness, particularly with respect to different rheological behaviors and also regarding different problem sizes and types of nonlinearity. Here, local pressure Schur complement techniques are presented as a generalization of the classical Vanka smoother. The discussed methodology is implemented for the well‐known flow around cylinder benchmark configuration for generalized Newtonian as well as non‐Newtonian flows including non‐isothermal, shear/pressure dependent and viscoelastic effects.Copyright © 2012 John Wiley & Sons, Ltd.
The miR‐17‐92 cluster and its target THBS1 are differentially expressed in angiosarcomas dependent on MYC amplification
Authors: Italiano Antoine , Thomas Rachael , Breen Matthew , Zhang Lei , Crago Aimee M. , Singer Samuel , Khanin Raya , Maki Robert G. , Mihailovic Aleksandra , Hafner Markus , Tuschl Tom , Antonescu Cristina R. 
Published: March 2012

AbstractAngiosarcomas (ASs) represent a heterogeneous group of malignant vascular tumors that may occur spontaneously as primary tumors or secondarily after radiation therapy or in the context of chronic lymphedema. Most secondary ASs have been associated with MYC oncogene amplification, whereas the role of MYC abnormalities in primary AS is not well defined. Twenty‐two primary and secondary ASs were analyzed by array‐comparative genomic hybridization (aCGH) and by deep sequencing of small RNA libraries. By aCGH and subsequently confirmed by fluorescence in situ hybridization, MYC amplification was identified in three out of six primary tumors and in 8 out of 12 secondary AS. We have also found MAML1 as a new potential oncogene in MYC‐amplified AS. Significant upregulation of the miR‐17‐92 cluster was observed in MYC‐amplified AS compared to AS lacking MYC amplification and the control group (other vascular tumors, nonvascular sarcomas). Moreover, MYC‐amplified ASs were associated with a significantly lower expression of thrombospondin‐1 (THBS1) than AS without MYC amplification or controls. Altogether, our study implicates MYC amplification not only in the pathogenesis of secondary AS but also in a subset of primary AS. Thus, MYC amplification may play a crucial role in the angiogenic phenotype of AS through upregulation of the miR‐17‐92 cluster, which subsequently downregulates THBS1, a potent endogenous inhibitor of angiogenesis. © 2012 Wiley Periodicals, Inc.
Opposite roles of FOXA1 and NKX2‐1 in lung cancer progression
Authors: Deutsch Lena , Wrage Michaela , Koops Susann , Glatzel Markus , Uzunoglu Faik G. , Kutup Asad , Hinsch Andrea , Sauter Guido , Izbicki Jakob R. , Pantel Klaus , Wikman Harriet 
Published: March 2012

AbstractGene copy number profiles of primary lung tumors were screened for high‐level amplifications. We detected 22 high‐level amplifications in various loci, including 14q13. This locus is known to harbor the adenocarcinoma (AC) lineage‐specific target gene NKX2‐1, which is not expressed in squamous cell carcinoma (SCC). As the 14q amplification was also found in SCC, we investigated whether or not FOXA1 might be the corresponding target gene for SCC. Focusing on these two target genes, we assessed gene amplifications and protein expression of NKX2‐1 and FOXA1 in primary lung tumors (n = 554) and brain metastases (n = 68). Primary AC (n = 194) showed positive protein expression of NKX2‐1 in 58.2% of the samples compared with 4.2% of primary SCC samples (n = 212). Positive staining for FOXA1 was seen in 34.7% of the SCC samples, which was comparable with 39.6% in the AC samples. For brain metastases, FOXA1 expression was slightly higher in the SCC samples (55.6%) compared with the non‐matched primary SCC tumor samples (43.4%), whereas NKX2‐1 expression was comparable in both primary tumors and brain metastases. Positive FOXA1 and NKX2‐1 expression was associated with a gain or amplification in 34.6% and 28.6% of cases, respectively. The expression of NKX2‐1 was associated with early stage and grade among the AC cases. In contrast, FOXA1 expression in SCC was associated with distant metastases as well as an unfavorable survival rate (P = 0.039). These results suggest that both FOXA1 and NKX2‐1 may act as lineage‐specific target genes within the 14q amplicon with opposite functions in lung cancer. © 2012 Wiley Periodicals, Inc.
Energizing Project‐Based Inquiry: Middle‐Grade Students Read, Write, and Create Videos
Authors: Spires Hiller A. , Hervey Lisa G. , Morris Gwynn , Stelpflug Catherine 
Published: March 2012

AbstractIn light of emerging technologies prompting new avenues for teaching and learning, students are positioned to “create” to learn, with video production being an important process for literacy development. There is a growing need for innovative instructional practices in reading and writing that are aligned with student interests and the activities they engage in outside of the classroom. Connecting video production to school reading and writing experiences taps into a student's natural predisposition for media consumption and production. This article presents a project‐based inquiry process that merges students’ growing interest in grassroots video with educational goals that are aligned with state and national curricular standards. Through a five‐phase process—ask a compelling question; gather and analyze information; creatively synthesize information; critically evaluate and revise; and publish, share, and act—students are engaged in reading, writing, and creating a video product that captures their multimodal learning of academic content.
Visible Voices: Literacy Identity and the Invisible Homeless
Authors: Juchniewicz Melissa M. 
Published: March 2012

AbstractDespite calls for increased awareness of and sensitivity to diverse students and their in‐ and out‐of‐school literacies, the “invisible homeless”—those who often decline to self‐identify—receive inadequate scholarly attention. They are often individuals who fear the stigma associated with homelessness as they navigate workplace, academic, and institutional systems, which frequently encourage corruption and silencing. Nevertheless, some homeless make successful transitions into improved situations and actively engage in strategies to empower themselves. This manuscript is based on a study that explored literacy's role in those strategies for five people, and how self‐perceptions of their own literacies influenced and were influenced by their transitions. Findings included highly valuing literacy skills, and that participants took time to understand and change (read and write) their environments. These findings will benefit educators and others as we encounter increasing numbers of homeless individuals in classrooms, on campuses, and sharing the benefits of society.
A complete set of self‐consistent charge density‐functional tight‐binding parametrization of zinc chalcogenides (ZnX; X=O, S, Se, and Te)
Authors: Saha Supriya , Pal Sougata , Sarkar Pranab , Rosa A. L. , Frauenheim Th. 
Published: March 2012

AbstractWe have developed a complete set of self‐consistent charge density‐functional tight‐binding parameters for ZnX (X = Zn, O, S, Se, Te, Cd, H, C, and N). The transferability of the derived parameters has been tested against Pseudo Potential‐Perdew, Burke and Ernzerhof (PP‐PBE) calculations and experimental values (whenever available) for corresponding bulk systems (e.g., hexagonal close packing, zinc‐blende, and wurtzite(wz)), various kinds of nanostructures (such as nanowires, surfaces, and nanoclusters), and also some small molecular systems. Our results show that the derived parameters reproduce the structural and energetic properties of the above‐mentioned systems very well. With the derived parameter set, one can study zinc‐chalcogenide nanostructures of relatively large size which was otherwise prohibited by other methods. The Zn‐Cd parametrization developed in this article will help in studying large semiconductor hetero‐nanostructures of Zn and Cd chalcogenides such as ZnX/CdX core/shell nanoparticles, nanotubes, nanowires, and nanoalloys. © 2012 Wiley Periodicals, Inc.
An Effective and New Method for the Synthesis of Polysubstituted Imidazoles by the Use of CrCl3.6H2O as a Green and Reusable Catalyst: Synthasis of Some Novel Imidazole Derivatives
Authors: Karami Bahador , Eskandari Khalil , Farahi Mahnaz , Barmas Akram 
Published: March 2012

AbstractNew, efficient and environmentally adapted synthesis of polysubstituted imidazoles in one‐pot is found. The multicomponent reaction of various aldehydes, benzil, aliphatic and aromatic primary amines and ammonium acetate under solvent‐free condition is explained. The highly efficient role of CrCl3.6H2O as catalyst in this synthesis was shown. By this advantage, several polysubstituted imidazoles as pharmaceutical important molecules can be prepared in high yield and high purity. This method is a very easy and a rapid reaction for the synthesis of imidazole derivatives. The crude products recrystallized to afford the crystalline pure products. Furthermore, catalyst exhibited remarkable reusable activity.
STATE‐BUSINESS RELATIONS, INVESTMENT CLIMATE REFORM AND FIRM PRODUCTIVITY IN SUB‐SAHARAN AFRICA
Authors: Saeed Qureshi Mahvash , te Velde Dirk Willem 
Published: March 2012

AbstractThis paper examines whether an effective state‐business relationship, facilitated by an organised private sector, improves firm performance in seven sub‐Saharan African countries: Benin, Ethiopia, Madagascar, Malawi, Mauritius, South Africa and Zambia. The findings reveal that, on average, state‐business relationships enhance firm productivity by about 25–35 per cent in sub‐Saharan African firms. This effect appears to set in through an improved investment climate—including reduced corruption, better provision of public utilities and information technology development—and higher labour productivity. These gains are not confined to small and medium sized firms but have a similar positive impact on large firms. Further, both domestic and foreign‐owned firms appear to benefit from joining business associations, although the impact is somewhat larger for the latter. Copyright © 2012 John Wiley & Sons, Ltd.
Pre‐ and postnatal calorie restriction perturbs early hypothalamic neuropeptide and energy balance
Authors: Shin Bo‐Chul , Dai Yun , Thamotharan Manikkavasagar , Gibson L. Caroline , Devaskar Sherin U. 
Published: March 2012

AbstractEnergy balance is regulated by circulating leptin concentrations and hypothalamic leptin receptor (ObRb) signaling via STAT3 but is inhibited by SOCS3 and PTP1B. Leptin signaling enhances anorexigenic neuropeptides and receptor (POMC, MC3‐R, MC4‐R) activation while suppressing orexigenic neuropeptides (NPY, AgRP). We investigated in a sex‐specific manner the early (PN2) and late (PN21) postnatal hypothalamic mechanisms in response to intrauterine (IUGR), postnatal (PNGR), and combined (IPGR) calorie and growth restriction. At PN2, both male and female IUGR were hypoleptinemic, but hypothalamic leptin signaling in females was activated as seen by enhanced STAT3. In addition, increased SOCS3 and PTP1B supported early initiation of leptin resistance in females that led to elevated AgRP but diminished MC3‐R and MC4‐R. In contrast, males demonstrated leptin sensitivity seen as a reduction in PTP1B and MC3‐R and MC4‐R with no effect on neuropeptide expression. At PN21, with adequate postnatal caloric intake, a sex‐specific dichotomy in leptin concentrations was seen in IUGR, with euleptinemia in males indicative of persisting leptin sensitivity and hyperleptinemia in females consistent with leptin resistance, both with normal hypothalamic ObRb signaling, neuropeptides, and energy balance. In contrast, superimposition of PNGR upon IUGR (IPGR) led to diminished leptin concentrations with enhanced PTP1B and an imbalance in arcuate nuclear NPY/AgRP and POMC expression that favored exponential hyperphagia and diminished energy expenditure postweaning. We conclude that IUGR results in sex‐specific leptin resistance observed mainly in females, whereas PNGR and IPGR abolish this sex‐specificity, setting the stage for acquiring obesity after weaning. © 2012 Wiley Periodicals, Inc.
Disruption of exploratory and habituation behavior in mice with mutation of DISC1: an ethologically based analysis
Authors: Walsh J. , Desbonnet L. , Clarke N. , Waddington J.L. , O'Tuathaigh C.M.P. 
Published: March 2012

AbstractDisrupted‐in‐schizophrenia‐1 (DISC1) is a gene that has been functionally linked with neurodevelopmental processes and structural plasticity in the brain. Clinical genetic investigations have implicated DISC1 as a genetic risk factor for schizophrenia and related psychoses. Studies using mutant mouse models of DISC1 gene function have demonstrated schizophrenia‐related anatomical and behavioral endophenotypes. In the present study, ethologically based assessment of exploratory and habituation behavior in the open field was conducted in DISC1 (L100P), wild‐type (WT), heterozygous (HET), and homozygous (HOM) mutant mice of both sexes. Ethological assessment was conducted in an open‐field environment to explore specific topographies of murine exploratory behavior across the extended course of interaction from initial exploration through subsequent habituation (the ethogram). During initial exploration, HET and HOM DISC1 mutants evidenced increased levels of locomotion and rearing to wall compared with WT. A HOM‐specific increase in total rearing and a HET‐specific increase in sifting behavior and reduction in rearing seated were also observed. Over subsequent habituation, locomotion, sniffing, total rearing, rearing to wall, rearing free, and rearing seated were increased in HET and HOM mutants vs. WT. Overall, grooming was increased in HOM relative to other genotypes. HET mice displayed a selective decrease in habituation of sifting behavior. These data demonstrate impairment in both initial exploratory and habituation of exploration in a novel environment in mice with mutation of DISC1. This is discussed in the context of the functional role of the gene vis à vis a schizophrenia phenotype as well as the value of ethologically based approaches to behavioral phenotyping. © 2012 Wiley Periodicals, Inc.