bluuebunny/crossref_metadata_2025_split huggingface dataset:
Solvent‐Free Catalytic Depolymerization of Cellulose to Water‐Soluble Oligosaccharides
Authors: Meine Niklas , Rinaldi Roberto , Schüth Ferdi 
Published: April 2012

AbstractThe use of cellulose is hampered by difficulties with breaking up the biopolymer into soluble products. Herein, we show that the impregnation of cellulosic substrates with catalytic amounts of a strong acid (e.g., H2SO4, HCl) is a highly effective strategy for minimizing the contact problem commonly experienced in mechanically assisted, solid‐state reactions. Milling the acid‐impregnated cellulose fully converts the substrate into water‐soluble oligosaccharides within 2 h. In aqueous solution, soluble products are easily hydrolyzed at 130 °C in 1 h, leading to 91 % conversion of the glucan fraction of α‐cellulose into glucose, and 96 % of the xylans into xylose. Minor products are glucose dimers (8 %), 5‐hydroxymethylfurfural (1 %) and furfural (4 %). Milling practical feedstocks (e.g., wood, sugarcane bagasse, and switchgrass) also results to water‐soluble products (oligosaccharides and lignin fragments). The integrated approach (solid‐state depolymerization in combination with liquid‐phase hydrolysis) could well hold the key to a highly efficient “entry process” in biorefinery schemes.
Epidemiologic studies of exposure to prenatal infection and risk of schizophrenia and autism
Authors: Brown Alan S. 
Published: April 2012

AbstractIn this review, we provide a synopsis of work on the epidemiologic evidence for prenatal infection in the etiology of schizophrenia and autism. In birth cohort studies conducted by our group and others, in utero exposure to infectious agents, prospectively obtained after biomarker assays of archived maternal sera and by obstetric records was related to an increased risk of schizophrenia. Thus far, it has been demonstrated that prenatal exposure to influenza, increased toxoplasma antibody, genital–reproductive infections, rubella, and other pathogens are associated with schizophrenia. Anomalies of the immune system, including enhanced maternal cytokine levels, are also related to schizophrenia. Some evidence also suggests that maternal infection and immune dysfunction may be associated with autism. Although replication is required, these findings suggest that public health interventions targeting infectious exposures have the potential for preventing cases of schizophrenia and autism. Moreover, this work has stimulated translational research on the neurobiological and genetic determinants of these conditions. © 2012 Wiley Periodicals, Inc. Develop Neurobiol, 2012
Rhenium(I) and Technetium(I) Tricarbonyl Complexes with [NSO]‐Type Chelators: Synthesis, Structural Characterization, and Radiochemistry
Authors: Makris George , Karagiorgou Ourania , Papagiannopoulou Dionysia , Panagiotopoulou Angeliki , Raptopoulou Catherine P. , Terzis Aris , Psycharis Vassilis , Pelecanou Maria , Pirmettis Ioannis , Papadopoulos Minas S. 
Published: April 2012

AbstractThe reactions of the NSO ligands 2‐[2‐(pyridin‐2‐yl)ethylthio]acetic acid (HL1), 3‐[2‐(pyridin‐2‐yl)ethylthio]propanoic acid (HL2), 2‐(carboxymethylthio)‐3‐(1H‐imidazol‐4‐yl)propanoic acid (H2L3), and 2‐(carboxyethylthio)‐3‐(1H‐imidazol‐4‐yl)propanoic acid (H2L4) with [NEt4]2[ReBr3(CO)3] are presented. Ligands HL1, H2L3, and H2L4 act as tridentate NSO chelators and readily generate the fac‐[Re(NSO)(CO)3]complexes Re‐L1, Re‐HL3, and Re‐HL4. Ligand HL2 acts as NSO tridentate chelator only in the presence of base to give complex Re‐L2, while without base it coordinates as a NS bidentate chelator to generate complex fac‐[ReBr(NS)(CO)3], Re‐HL2. All complexes were isolated and characterized by elemental analysis, IR and 1H, 13C NMR spectroscopy. Complex Re‐L1, Re‐HL2, and Re‐HL3 were characterized also by X‐ray crystallography. Furthermore, the analogous technetium complexes fac‐[99mTc(NSO)(CO)3]+, 99mTc‐L1, 99mTc‐L2, 99mTc‐HL3, and 99mTc‐HL4 were synthesized by reacting ligands HL1–H2L4 with the fac‐[99mTc(OH2)3(CO)3]+ precursor for 30 min at 75 °C. The tracer complexes 99mTc‐L1–99mTc‐HL4 were found to be stable in L‐cysteine and L‐histidine challenge experiments. The bifunctional chelating agents that bear a second carboxylate group are promising for the development of targeted 99mTc radiopharmaceuticals.
Generation and Chemistry of Tricyclo[3.2.1.02,4]oct‐2(3)‐ene
Authors: Lee Gon‐Ann , Chan Lien‐En , Tsai Ru‐Ting , Chen Ko‐Chou 
Published: April 2012

AbstractThe 1,3‐fused polycyclic cyclopropene, tricyclo[3.2.1.02,4]oct‐2(3)‐ene 25, was synthesized by the elimination of trimethylsilyl chloride from 2‐chloro‐3‐(trimethylsilyl)tricyclo[3.2.1.02,4]octane 20. However, the high strain in the system favors the ring‐opened vinylcarbene form, which undergoes a number of reactions including the addition of water, insertion into the C–H bond α to the oxygen atom in tetrahydrofuran (THF), and [1+2] addition to the C=C bond in furan. The stereoselectivity of the addition of H2O and THF to the vinylcarbene are similar, and exo products were preferably formed. As a result of electronic and steric effects, intermediate 26 reacted with furan and preferentially yielded the endo product 27. Furthermore, on heating, the addition products 27 and 28 rearranged to aldehyde 29.
Application of 2‐Azido‐2‐deoxythioglycosides for β‐Glycoside Formation and Oligosaccharide Synthesis
Authors: Mong Kwok‐Kong Tony , Yen Yu‐Fang , Hung Wei‐Cheng , Lai Yen‐Hsun , Chen Jiun‐Han 
Published: April 2012

AbstractMost natural 2‐acetamido‐2‐deoxyglycosides exist in a 1,2‐trans‐β‐glycosidic configuration. This study investigated the use of 2‐azido‐2‐deoxythioglycosides for 1,2‐trans‐β‐glycosidic bond formation under low‐concentration glycosylation conditions. Further application of the 2‐azido‐2‐deoxythioglycosyl substrates for one‐pot oligosaccharide synthesis was demonstrated in the synthesis of protected β‐(1→6)‐N‐acetylglucosamine trimer, core‐6–serine conjugate, and F1–α serine conjugate.
A U‐Turn in the Asymmetric Appel Reaction: Stereospecific Reduction of Diastereomerically Enriched Alkoxyphosphonium Salts Allows the Asymmetric Synthesis of P‐Stereogenic Phosphanes and Phosphane Boranes
Authors: Rajendran Kamalraj V. , Kudavalli Jaya S. , Dunne Katherine S. , Gilheany Declan G. 
Published: April 2012

AbstractAn efficient one‐pot synthesis has been developed of enantioenriched P‐stereogenic phosphanes and phosphane boranes from the corresponding racemic phosphanes in excellent yield under asymmetric Appel conditions. The chiral auxiliary (menthol) can also be recovered unchanged. The simple and efficient protocol significantly expands the scope of our asymmetric Appel process. The crucial step in the preparation involves stereospecific reduction of intermediate diastereomeric alkoxyphosphonium salts, which are obtained in the reaction of phosphane, hexachloroacetone, and menthol. Thereby, reaction with LiAlH4 or NaBH4 gives the corresponding phosphanes or phosphane boranes, respectively.
Evaluation of indoor air quality models with the ranked statistical performance measures using available software
Authors: Kadiyala Akhil , Kumar Ashok 
Published: April 2012

AbstractOver the last two decades, rapid advancements have been made in the field of environmental science and engineering that eventually led to the development of new modeling techniques. It is essential that these newly developed modeling techniques be validated before they are incorporated and applied in the real‐world. Statistical performance measures play a major role in the model validation by comparing the observations with the modeled predictions. One of the serious limitations in the current literature is that very few studies have used a comprehensive set of the ranked performance measures for validating the newly developed indoor air quality models. This study fills the knowledge gap by demonstrating the use of ranked acceptance criteria for validation of an indoor air quality modeling problem in public transit buses using available software. © 2012 American Institute of Chemical Engineers Environ Prog, 2012
The Impact of Self‐Reported Pubertal Status and Pubertal Timing on Disordered Eating in Irish Adolescents
Authors: McNicholas Fiona , Dooley Barbara , McNamara Niamh , Lennon Ruth 
Published: April 2012

AbstractThis paper considers the impact of pubertal status and pubertal timing on disordered eating in Irish adolescents. 1190 boys and 1841 girls completed the Eating Attitudes Test‐26, the Eating Disorder Inventory‐III and self‐report measures of pubertal status and pubertal timing. Regarding pubertal status, greater maturity in girls was associated with increased overall eating concerns, higher drive for thinness and higher levels of body dissatisfaction. In boys, greater maturity was associated with lower drive for thinness and lower body dissatisfaction. Regarding pubertal timing, early‐maturing girls showed the most eating concerns, the highest drive for thinness, scored highest on bulimic symptoms and were the most dissatisfied with their bodies. In contrast, late‐maturing boys had more bulimic symptoms and more dissatisfaction with their bodies than on‐time peers. The findings suggest that puberty itself is a risk factor for disordered eating for girls rather than boys; however, pubertal timing is a risk factor for both. Copyright © 2012 John Wiley & Sons, Ltd and Eating Disorders Association.
Controls of streamflow generation in small catchments across the snow–rain transition in the Southern Sierra Nevada, California
Authors: Liu Fengjing , Hunsaker Carolyn , Bales Roger C. 
Published: April 2012

AbstractProcesses controlling streamflow generation were determined using geochemical tracers for water years 2004–2007 at eight headwater catchments at the Kings River Experimental Watersheds in southern Sierra Nevada. Four catchments are snow‐dominated, and four receive a mix of rain and snow. Results of diagnostic tools of mixing models indicate that Ca2+, Mg2+, K+ and Cl− behaved conservatively in the streamflow at all catchments, reflecting mixing of three endmembers. Using endmember mixing analysis, the endmembers were determined to be snowmelt runoff (including rain on snow), subsurface flow and fall storm runoff. In seven of the eight catchments, streamflow was dominated by subsurface flow, with an average relative contribution (% of streamflow discharge) greater than 60%. Snowmelt runoff contributed less than 40%, and fall storm runoff less than 7% on average. Streamflow peaked 2–4 weeks earlier at mixed rain–snow than snow‐dominated catchments, but relative endmember contributions were not significantly different between the two groups of catchments. Both soil water in the unsaturated zone and regional groundwater were not significant contributors to streamflow. The contributions of snowmelt runoff and subsurface flow, when expressed as discharge, were linearly correlated with streamflow discharge (R2 of 0.85–0.99). These results suggest that subsurface flow is generated from the soil–bedrock interface through preferential pathways and is not very sensitive to snow–rain proportions. Thus, a declining of the snow–rain ratio under a warming climate should not systematically affect the processes controlling the streamflow generation at these catchments. Copyright © 2012 John Wiley & Sons, Ltd.
Gr‐1+CD11b+ cells are responsible for tumor promoting effect of TGF‐β in breast cancer progression
Authors: Li Zhaoyang , Pang Yanli , Gara Sudheer Kumar , Achyut B.R. , Heger Christopher , Goldsmith Paul K. , Lonning Scott , Yang Li 
Published: April 2012

AbstractOne great challenge in our understanding of TGF‐β cancer biology and the successful application of TGF‐β‐targeted therapy is that TGF‐β works as both a tumor suppressor and a tumor promoter. The underlying mechanisms for its functional change remain to be elucidated. Using 4T1 mammary tumor model that shares many characteristics with human breast cancer, particularly its ability to spontaneously metastasize to the lungs, we demonstrate that Gr‐1+CD11b+ cells or myeloid derived suppressor cells are important mediators in TGF‐β regulation of mammary tumor progression. Depletion of Gr‐1+CD11b+ cells diminished the antitumor effect of TGF‐β neutralization. Two mechanisms were involved: first, treatment with TGF‐β neutralization antibody (1D11) significantly decreased the number of Gr‐1+CD11b+ cells in tumor tissues and premetastatic lung. This is mediated through increased Gr‐1+CD11b+ cell apoptosis. In addition, 1D11 treatment significantly decreased the expression of Th2 cytokines and Arginase 1. Interestingly, the number and property of Gr‐1+CD11b+ cells in peripheral blood/draining lymph nodes correlated with tumor size and metastases in response to 1D11 treatment. Our data suggest that the efficacy of TGF‐β neutralization depends on the presence of Gr‐1+CD11b+ cells, and these cells could be good biomarkers for TGF‐β‐targeted therapy.
Heterogeneity of high‐grade cervical intraepithelial neoplasia related to HPV16: Implications for natural history and management
Authors: Wentzensen Nicolas , Walker Joan , Schiffman Mark , Yang Hannah P. , Zuna Rosemary E. , Dunn S. Terence , Allen R. Andy , Zhang Roy , Sherman Mark , Gold Michael A. , Wang Sophia S. 
Published: April 2012

AbstractFactors associated with progression from cervical intraepithelial neoplasia (CIN) grades 2 and 3 to invasive cancer are not well understood; most CIN2 and CIN3 do not progress to cancer. Among carcinogenic human papillomavirus (HPV) types, infections with HPV16 have the highest risk of progressing to cancer. We evaluated the heterogeneity of risk factors, lesion size, colposcopic impression and colposcopic biopsy results in relation to HPV16 status among 627 women with CIN2 or CIN3 in women referred to colposcopy at the University of Oklahoma. Loop excision specimens were evaluated in 12 radial segments to estimate lesion size. The mean age at CIN3 was 27.7 years for HPV16‐positive women (n = 225) and 33.6 years for HPV16‐negative women (n = 104). The average lesion size did not differ by HPV16 status (p = 0.83). Among HPV16‐positive women with CIN3, lesions were significantly larger in women 30 years and older (p = 0.03). Colposcopic impression was worse in women with HPV16 infections (p = 0.009), but the detection of CIN3 at the preceding biopsy was not improved in HPV16‐positive women. CIN3 is detected at the same lesion size, but at much younger age in women with HPV16 infections, suggesting faster growth. CIN2 lesion size in women without HPV16 peaks below 30 years and then decreases, suggesting frequent regression, whereas HPV16‐related CIN2 is more likely to persist. Lesion size seems to be an important determinant of colposcopy and biopsy performance. Genotyping for HPV16 in cervical cancer screening can improve risk stratification but may pose challenges to finding small lesions in colposcopy.
Estrogen receptor‐β protects against colitis‐associated neoplasia in mice
Authors: Saleiro Diana , Murillo Genoveva , Benya Richard V. , Bissonnette Marc , Hart John , Mehta Rajendra G. 
Published: April 2012

AbstractEstrogen receptor‐beta (ERβ) has been suggested to exert anti‐inflammatory and anti‐tumorigenic effects in the colon, providing a translational potential to prevent and/or treat inflammatory bowel disease (IBD) and its progression to colitis‐associated colorectal cancer (CAC). However, the specific direct role of ERβ in CAC has not yet been tested. We assessed the effects of ERβ deficiency in the azoxymethane (AOM)/dextran sodium sulfate (DSS)‐induced CAC model using ERβ knockout (βERKO) mice and wild‐type (WT) littermates. These mice were injected with AOM followed by 1 week of DSS treatment, and sacrificed on weeks 9 or 16. βERKO mice developed more severe clinical colitis compared to WT mice, as evidenced by significantly higher disease activity index after DSS treatment, weight to length ratio of the colons, inflammation score and grade of dysplasia. ERβ‐deficient colons presented greater number and size of polyps at weeks 9 and 16, respectively, and were characterized by a significant increase in interleukin (IL)‐6, IL‐17, tumor necrosis factor alpha and interferon‐gamma mRNA levels. Furthermore, higher protein expression levels of nuclear factor‐kappa B, inducible nitric oxide synthase, β‐catenin, proliferating cell nuclear antigen, mucin‐1 and significantly lower caveolin‐1 and mucin‐2 protein levels were shown in βERKO mice compared to WT mice. These data suggest a possible anti‐inflammatory and anti‐neoplastic mechanism of action of ERβ in CAC. These results demonstrate for the first time that ERβ provides protection in the AOM/DSS‐induced CAC model in mice, suggesting a preventive and/or therapeutic potential for the use of ERβ‐selective agonists in IBD.
Study on the dissolved oxygen control strategy in large‐scale vitamin B12 fermentation by Pseudomonas denitrificans
Authors: Li Kun‐Tai , Zhou Jia , Cheng Xin , Wei Sai‐jin 
Published: April 2012

AbstractBACKGROUND: There are two different routes for vitamin B12 biosynthesis, which results in discrepancies and uncertainties of the dissolved oxygen (DO) concentration for vitamin B12 fermentation. In this paper, the DO control strategy was explored for industrial vitamin B12 fermentation by Pesudomonas denitrificans in 120000‐L fermenter.RESULTS: A DO‐stat strategy was first successfully scaled up from a 9000 L fermenter to a 120 000 L fermenter. Then a multi‐stage DO control strategy was further established in the 120 000 L fermenter, in which the DO level was shifted from 8–10% (20–48 h) to 2–5% (49–106 h) and below 2% (107–168 h) by gradually reducing the rate of aeration and agitation. As a result, 198.80 mg L−1 of vitamin B12 was obtained, which was significantly higher than those obtained under the fermentations with one‐stage DO control.CONCLUSIONS: The comparatively low DO level was favorable for vitamin B12 biosynthesis, but it would have an extremely negative effect on cell growth. Compared with the low DO level maintained at all times of the fermentation process, a multi‐stage DO control strategy could not only increase the biomass but also improve vitamin B12 biosynthesis. Copyright © 2012 Society of Chemical Industry
Extracellular heat shock protein 72 protects schwann cells from hydrogen peroxide‐induced apoptosis
Authors: Luo Xinjing , Tao Lingjian , Lin Peng , Mo Xuanrong , Chen Haixiao 
Published: April 2012

AbstractThe cytoprotective role of extracellular heat shock protein (Hsp) 72 has been demonstrated in various cell types, including neuronal cells; however, few studies have investigated the actual role of Hsp72 in the survival of Schwann cells (SCs). In the present study, we investigated the effect of exogenous Hsp72 on Schwann cell apoptotic cell death induced by H2O2. We determined that extracellular exposure to Hsp72 reduced cell death in rat SCs in a dose‐dependent manner, with the protection resulting from downregulation of apoptosis induced by H2O2 (as shown by TUNEL and annexin V flow cytometry analyses). Moreover, we observed that Hsp72 suppressed caspase‐3 and −9 activation induced by H2O2. This was accompanied by upregulation of the antiapoptotic protein Bcl‐2. These findings indicate that extracellular Hsp72 can afford neuroprotection to peripheral nerves via its ability to inhibit Schwann cell apoptosis and diminish oxidative stress‐mediated injuries. © 2012 Wiley Periodicals, Inc.
Technical skills improve after practice on virtual‐reality temporal bone simulator
Authors: Francis Howard W. , Malik Mohammad U. , Diaz Voss Varela David A. , Barffour Maxwell A. , Chien Wade W. , Carey John P. , Niparko John K. , Bhatti Nasir I. 
Published: April 2012

AbstractObjectives/Hypothesis:To assess whether practice on a virtual‐reality (VR) temporal bone simulator improves acquisition of technical skills in mastoid surgery.Study Design:Prospective blinded study.Methods:Using a previously validated objective structured assessment of technical skills (OSATS) tool, performance was assessed in 12 residents for two tasks of cortical mastoidectomy: 1) identifying and defining the tegmen and 2) defining the sigmoid sinus and sinodural angle. These surgical tasks were chosen as key steps in mastoid dissection because they were of intermediate complexity. Videos of virtual dissections were captured at baseline and again after practicing each task four to six times.Results:OSATS scores for the tegmen task increased from 2.125 ± 1.25 to 3.1 ± 0.85 (P = .026), whereas for the sigmoid task scores increased from 2 ± 0.45 to 2.75 ± 1.125 (P = .0098). The time to complete the tasks decreased from 8.37 ± 4.78 minutes to 5.39 ± 3.06 minutes (P = .018) for the tegmen task and from 8.99 ± 6.7 minutes to 8.68 ± 5.98 minutes (P = .594) for the sigmoid task. There was a decline in number of injuries from 0.5 ± 1.5 to 0 ± 0.5 (P = .594) for the tegmen task and from 2.5 ± 4 to 0.5 ± 1 (P = .029) for the sigmoid task.Conclusions:Technical skills in mastoidectomy surgery can be acquired during even brief practice on the VR temporal bone simulator. It is anticipated that longer periods of practice presented within the fundamentals of comprehensive curriculum will facilitate procedural learning. Further studies are required to elucidate evidence of transference of these skills to the operating room and to procedures of greater complexity.
Heat development at nasal endoscopes' tips: Danger of tissue damage? A laboratory study
Authors: Tomazic Peter Valentin , Hammer Georg Philipp , Gerstenberger Claus , Koele Wolfgang , Stammberger Heinz 
Published: April 2012

AbstractObjectives/Hypothesis:The aim of this study was to measure the temperature generated by light sources in conjunction with angulated endoscopes and to analyze whether the heat generated at the endoscopes' tips harbors potential damage to mucosa or highly sensitive structures like the optic nerve or brain when in direct contact, considering a beginning necrosis of human protein starting at 40°C.Study Design:Laboratory setting, prospective.Methods:Brand new 4‐mm, 0° and 30° rigid nasal endoscopes were measured each with halogen, xenon, and light‐emitting diode (LED) light sources, respectively, at different power levels for tip contact temperature.Results:The highest temperatures were reached with a xenon light source at a maximum of 44.3°C, 65.8°C, and 91.4°C at 33%, 66%, and 100% power levels, respectively, for 4‐mm, 0° endoscopes. For 30° endoscopes, temperatures of 47.0°C, 75.1°C, and 95.5°C were measured at 33%, 66%, and 100% power levels (P < .001; 0° vs. 30°), respectively. At 5‐mm distance from the tip, temperatures were below body temperature for all light sources (<36°C) at all power settings. Within 2 minutes after switching off light sources, temperatures dropped to room temperature (22°C).Conclusions:Xenon light sources have the greatest illumination potential; however, at only 33% power level, potentially harmful temperatures can be reached at the tips of the endoscopes. Power LED and halogen have the highest safety; however, only LED has very good illumination. In narrow corridors, direct contact to tissues or vital structures should be avoided, or endoscopes should be cooled during surgical procedures.