bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nitrogenated‐Graphite‐Encapsulated Carbon Black as a Metal‐Free Electrocatalyst for the Oxygen Evolution Reaction in Acid
Authors: Zhu Yansong , Zhang Tianran , Lee Jim Yang 
Published: December 2017

AbstractNo metal needed: A core‐shell‐like carbon catalyst consisting of a few layers of nitrogen‐doped graphite on a carbon black core was prepared by pyrolyzing an ionic liquid (IL) with carbon black (CB) particles. The catalyst has a noticeably improved OER performance of the nanocarbon in acid solution. The resilience of the catalyst in acid solution is due to the greater protection of the nitrogen‐containing OER active sites in a graphitic shell.The oxygen evolution reaction (OER) in acid solution is very challenging for metal‐free catalysts based only on heteroatom‐doped carbon nanomaterials which have thus far shown relatively low catalytic activity and poor stability. Herein, we report a core‐shell‐like carbon catalyst consisting of a few layers of nitrogen‐doped graphite on a carbon black core prepared by pyrolyzing an ionic liquid (IL) with carbon black (CB) particles. The catalyst prepared as such has a noticeably improved OER performance of the nanocarbon in acid solution (1.70 V at a current density of 10 mA cm−2) in comparison with the few metal‐free OER electrocatalysts reported to date. The experimental results suggest that the resilience of the catalyst in acid solution is due to the greater protection of the nitrogen‐containing OER active sites in a graphitic shell.
Gold(II) Trihalide Complexes from Organogold(III) Precursors
Authors: Baya Miguel , Pérez‐Bitrián Alberto , Martínez‐Salvador Sonia , Martín Antonio , Casas José M. , Menjón Babil , Orduna Jesús 
Published: December 2017

AbstractThe mononuclear gold(II) halide complexes [AuCl3]− and [AuBr3]− are formed in the gas phase by collision‐induced homolytic splitting of the only Au−C bond in the monoalkylgold(III) precursors [CF3AuX3]−. The geometries of the whole series of [AuX3]− complexes (X=F, Cl, Br, I) have been calculated by DFT methods. It has also been found that the neutral AuX2 molecules behave as unsaturated species, showing significant affinity for an additional X− ligand. Moreover, in the open‐shell [AuX3]− anions, homolytic splitting of one of the Au−X bonds and formation of the lower‐valent [AuX2]− anions is favored over non‐reducing halide dissociation. They should therefore be prone to disproportionation.
Tuning of Polyoxopalladate Macroanionic Hydration Shell via Countercation Interaction
Authors: He Jiazhi , Li Hui , Yang Peng , Haso Fadi , Wu Jiayingzi , Li Tao , Kortz Ulrich , Liu Tianbo 
Published: December 2017

AbstractThree types of macroanion–countercation interactions in dilute solution, decided by the strength of electrostatic attraction and the change of hydration shells are reported: minor interaction between macroanions [MO8Pd12(SeO3)8]6− (M=Zn2+ or Ni2+) and monovalent cations (Na+, K+, Rb+, Cs+), leaving their hydration shells intact (solvent‐separated ion‐pairs); strong binding between macroanions and divalent cations (Sr2+, Ba2+) to form solvent‐shared ion‐pairs with partial dehydration; very strong electrostatic attraction between macroanions and Y3+ ion with contact ion‐pairs formation by severely breaking their original hydration shells and forming new ones. In addition, divalent cations can help the macroanions self‐assemble into hollow spherical blackberry structures through counterion‐mediated attraction, whereas macroanions with mono‐ or trivalent cations only stay as discrete ions due to either weak interaction or a small number of bound countercations.
High‐performance liquid chromatographic enantioseparation of N‐aryl‐thioureidoalkylphosphonates and thiourylenedi(alkylphosphonates) on polysaccharide‐based chiral stationary phases
Authors: Drabowicz Józef , Kudzin Marcin H. , Kudzin Zbigniew H. , Pokora‐Sobczak Patrycja 
Published: December 2017

AbstractThe first successful enantioseparation of representative O,O‐diphenyl‐N‐arylthioureidoalkylphosphonates, (±)‐Ptc‐ValP(OPh)2 & (±)‐Ptc‐LeuP(OPh)2 and thiourylenedi(isobutyl phosphonate), Tcm[ValP(OPh)2]2 on analytical and semipreparative scale was achieved by high‐performance liquid chromatography using polysaccharide‐based chiral stationary phases (CPs). Atc‐AAP(OPh)2 was obtained using modified tricomponent condensations of the corresponding aldehydes, N‐arylthiourea and triphenyl phosphite whereas Tcm[ValP(OPh)2]2 by the condensations of aldehydes, thiourea, and triphenyl phosphite. The prepared, racemic (±)‐Atc‐AAP(OPh)2 [(±)‐Ptc‐ValP(OPh)2, (±)‐Ptc‐LeuP(OPh)2, (±)‐Ptc‐PglyP(OPh)2 and (±)‐Ntc‐PglyP(OPh)2] and racemic (±)‐Tcm[AAP(OPh)2]2 [(±)‐Tcm[NvaP(OPh)2]2 & (±)‐Tcm[ValP(OPh)2]2] were adequately characterized and used for chromatographic separations on high‐performance liquid chromatography–chiral stationary phases. The best results were obtained for (±)‐Ptc‐ValP(OPh)2, (±)‐Ptc‐LeuP(OPh)2 and (±)‐Tcm[ValP(OPh)2]2.
Lipase‐catalyzed kinetic resolution of novel antitubercular benzoxazole derivatives
Authors: Łukowska‐Chojnacka Edyta , Kowalkowska Anna , Napiórkowska Agnieszka 
Published: December 2017

AbstractNovel benzoxazole derivatives were synthesized, and their antitubercular activity against sensitive and drug‐resistant Mycobacterium tuberculosis strains (M. tuberculosis H37Rv, M. tuberculosis sp. 210, M. tuberculosis sp. 192, Mycobacterium scrofulaceum, Mycobacterium intracellulare, Mycobacterium fortuitum, Mycobacterium avium, and Mycobacterium kansasii) was evaluated. The chemical step included preparation of ketones, alcohols, and esters bearing benzoxazole moiety. All racemic mixtures of alcohols and esters were separated in Novozyme SP 435‐catalyzed transesterification and hydrolysis, respectively. The transesterification reactions were carried out in various organic solvents (tert‐butyl methyl ether, toluene, diethyl ether, and diisopropyl ether), and depending on the solvent, the enantioselectivity of the reactions ranged from 4 to >100. The enzymatic hydrolysis of esters was performed in 2 phase tert‐butyl methyl ether/phosphate buffer (pH = 7.2) system and provided also enantiomerically enriched products (ee 88‐99%). The antitubercular activity assay has shown that synthesized compounds exhibit an interesting antitubercular activity. Racemic mixtures of alcohols, (±)‐4‐(1,3‐benzoxazol‐2‐ylsulfanyl)butan‐2‐ol ((±)‐3a), (±)‐4‐[(5‐bromo‐1,3‐benzoxazol‐2‐yl)sulfanyl]butan‐2‐ol ((±)‐3b), and (±)‐4‐[(5,7‐dibromo‐1,3‐benzoxazol‐2‐yl)sulfanyl]butan‐2‐ol ((±)‐3c), displayed as high activity against M. scrofulaceum, M. intracellulare, M. fortuitum, and M. kansasii as commercially available antituberculosis drug‐Isoniazid. Moreover, these compounds exhibited twice higher activity toward M. avium (MIC 12.5) compared with Isoniazid (MIC 50).
Retracted: Molecular Motions and Interactions in Aqueous Solutions of Thymosin‐β4, Stabilin C‐Terminal Domain (CTD) and Their 1:1 Complex Studied by 1H NMR Spectroscopy
Authors: Bokor Mónika , Tantos Ágnes , Mészáros Attila , Jenei Bence , Haminda Réka , Tompa Péter , Tompa Kálmán 
Published: December 2017

AbstractWide‐line 1H NMR measurements were extended and all results were reinterpreted in a new thermodynamics‐based approach to study aqueous solutions of thymosin‐β4 (Tβ4), stabilin C‐terminal domain (CTD) and their 1:1 complex. The energy distributions of the potential barriers, which control motion of protein‐bound water molecules, were determined. Heterogeneous and homogeneous regions were found at the protein–water interface. The measure of heterogeneity gives a quantitative value for the portion of disordered parts in the protein. Ordered structural elements were found extending up to 20 % of the whole proteins. About 40 % of the binding sites of free Tβ4 become involved in bonds holding the complex together. The complex has the most heterogeneous solvent accessible surface (SAS) in terms of protein–water interactions. The complex is more disordered than Tβ4 or stabilin CTD. The greater SAS area of the complex is interpreted as a clear sign of its open structure.
Genotypic characterization and comparison of Streptococcus mutans in American Indian and Southeast Iowa children
Authors: Villhauer Alissa L. , Lynch David J. , Warren John J. , Dawson Deborah V. , Blanchette Derek R. , Drake David R. 
Published: December 2017

AbstractEarly childhood caries is a complex health care issue that has a multifactorial etiology. One aspect of this etiology is the colonization and propagation of acidogenic bacteria at an early age. There have been several bacterial species associated with caries but 1 common species is Streptococcus mutans. Here, we describe genotypic diversity and commonality of Streptococcus mutans recovered from children representing 2 groups with similar socioeconomic demographics: a Northern Plains American Indian Tribe and a Southeast Iowa population. Forty 36‐month‐old American Indian children were selected from a cohort of 239 mothers and children, and forty 2‐ to 5‐year‐old children from Southeast Iowa were selected to compare the genotypic profiles of Streptococcus mutans recovered from each child's plaque. S. mutans isolates were selected from whole mouth plaque samples; DNA was extracted and amplified via AP‐PCR to show specific genotype patterns. These patterns were compared with GelComparIIv6.5 gel analysis software. We found 18 distinct genotypes from 524 isolates; 13 of which were common between the 2 communities. Five genotypes were unique to only the American Indian children while the Southeast Iowa children harbored no unique genotypes. Although the American Indian children had some genotypes that were not present in the Southeast Iowa children, these were not widely distributed among the community. Furthermore, the levels of genotypic diversity and commonality were similar between the 2 populations. This study sets the groundwork for a comprehensive comparison of genotypes and caries among larger subsections of both populations.
Shifts in frog size and phenology: Testing predictions of climate change on a widespread anuran using data from prior to rapid climate warming
Authors: Sheridan Jennifer A. , Caruso Nicholas M. , Apodaca Joseph J. , Rissler Leslie J. 
Published: December 2017

AbstractChanges in body size and breeding phenology have been identified as two major ecological consequences of climate change, yet it remains unclear whether climate acts directly or indirectly on these variables. To better understand the relationship between climate and ecological changes, it is necessary to determine environmental predictors of both size and phenology using data from prior to the onset of rapid climate warming, and then to examine spatially explicit changes in climate, size, and phenology, not just general spatial and temporal trends. We used 100 years of natural history collection data for the wood frog, Lithobates sylvaticus with a range >9 million km2, and spatially explicit environmental data to determine the best predictors of size and phenology prior to rapid climate warming (1901–1960). We then tested how closely size and phenology changes predicted by those environmental variables reflected actual changes from 1961 to 2000. Size, phenology, and climate all changed as expected (smaller, earlier, and warmer, respectively) at broad spatial scales across the entire study range. However, while spatially explicit changes in climate variables accurately predicted changes in phenology, they did not accurately predict size changes during recent climate change (1961–2000), contrary to expectations from numerous recent studies. Our results suggest that changes in climate are directly linked to observed phenological shifts. However, the mechanisms driving observed body size changes are yet to be determined, given the less straightforward relationship between size and climate factors examined in this study. We recommend that caution be used in “space‐for‐time” studies where measures of a species’ traits at lower latitudes or elevations are considered representative of those under future projected climate conditions. Future studies should aim to determine mechanisms driving trends in phenology and body size, as well as the impact of climate on population density, which may influence body size.
Evaluating the relationships of hypoglycaemia and HbA1c with screening‐detected diabetes distress in type 1 diabetes
Authors: Todd Peter J. , Edwards Faye , Spratling Laura , Patel Natasha H. , Amiel Stephanie A. , Sturt Jackie , Choudhary Pratik 
Published: December 2017

SummaryAimsTo explore the relationship between diabetes distress, glucose control and awareness of hypoglycaemia in adults with type 1 diabetes.MethodsWe performed a cross‐sectional study using data collected from 280 consecutive type 1 diabetes patients who used a routine clinic consultation tool that recorded HbA1c, hypoglycaemia awareness (measured using the Gold score) and diabetes distress (measured using the Diabetes Distress Scale 2 [DDS2]). We assessed correlations between DDS2 and HbA1c and DDS2 and Gold score and performed an ordinal regression analysis to identify factors contributing to distress.ResultsDiabetes distress was significantly correlated with HbA1c (r = .319, P < .001) and Gold score (r = .258, P < .001) independently and with synergistic effect. Female gender was also associated with diabetes distress, while age, BMI, duration of diabetes, severity of complications and use of CSII pumps were not. Occurrence of severe hypoglycaemia (SH) episodes increased with Gold score in a linear manner throughout the scale.ConclusionsThis study has identified new evidence of a significant, independent relationship between diabetes distress measured by the DDS2 and reduced awareness of hypoglycaemia in people with type 1 diabetes. It also demonstrates that diabetes distress is significantly associated with HbA1c and female gender independently. The DDS2 identifies distress associated with both hypo‐ and hyperglycaemia and can be a useful creening tool. Additionally, the occurrence of SH increases with increasing Gold score.
Adaptive immune response to Clostridium difficile infection: A perspective for prevention and therapy
Authors: Rees William D. , Steiner Theodore S. 
Published: December 2017

AbstractClostridium difficile infection (CDI) is one of the most important nosocomial illnesses and a major cause of morbidity and mortality. While initial treatment of CDI is usually successful, unprovoked relapses remain an important and frustrating problem. This review examines the literature describing the natural immune response to CDI, and to what extent it can explain the propensity for relapses. In particular, we discuss studies on antibody and, to a lesser extent, B cell and T cell responses in CDI. Despite years of study, there remains incomplete understanding of the natural antibody response to the major pathogenic toxins, TcdA and TcdB, and other bacterial antigens, in CDI. Recent literature suggests that a specific subset of neutralizing antibodies that target the putative carbohydrate‐binding domains of TcdB and possibly TcdA have the greatest protective ability. This is further supported by recent successful clinical trials of a humanized monoclonal antibody to the major toxin TcdB. A better understanding of how and why the most protective adaptive immune response develops may lead to improved vaccine and therapeutic targets for recurrent CDI.
Alterations in CA1 hippocampal synapses in a mouse model of fragile X syndrome
Authors: Jawaid Safdar , Kidd Grahame J. , Wang Jing , Swetlik Carrie , Dutta Ranjan , Trapp Bruce D. 
Published: December 2017

AbstractFragile X Syndrome (FXS) is the major cause of inherited mental retardation and the leading genetic cause of Autism spectrum disorders. FXS is caused by mutations in the Fragile X Mental Retardation 1 (Fmr1) gene, which results in transcriptional silencing of Fragile X Mental Retardation Protein (FMRP). To elucidate cellular mechanisms involved in the pathogenesis of FXS, we compared dendritic spines in the hippocampal CA1 region of adult wild‐type (WT) and Fmr1 knockout (Fmr1‐KO) mice. Using diolistic labeling, confocal microscopy, and three‐dimensional electron microscopy, we show a significant increase in the diameter of secondary dendrites, an increase in dendritic spine density, and a decrease in mature dendritic spines in adult Fmr1‐KO mice. While WT and Fmr1‐KO mice had the same mean density of spines, the variance in spine density was three times greater in Fmr1‐KO mice. Reduced astrocyte participation in the tripartite synapse and less mature post‐synaptic densities were also found in Fmr1‐KO mice. We investigated whether the increase in synaptic spine density was associated with altered synaptic pruning during development. Our data are consistent with reduced microglia‐mediated synaptic pruning in the CA1 region of Fmr1‐KO hippocampi when compared with WT littermates at postnatal day 21, which is the peak period of synaptic pruning in the mouse hippocampus. Collectively, these results support abnormal synaptogenesis and synaptic remodeling in mice deficient in FMRP. Deficits in the maturation and distribution of synaptic spines on dendrites of CA1 hippocampal neurons may play a role in the intellectual disabilities associated with FXS.
Rare presentation of heterotopic ossification along a fibula free flap pedicle in a high‐volume microvascular reconstruction practice
Authors: Mays Ashley C. , Gillenwater Ann M. , Garvey Patrick B. 
Published: December 2017

AbstractBackgroundHeterotopic ossification along free flap pedicles has been reported. Reports suggest that subperiosteal dissection of the pedicle from the bone during the harvest of the fibula free flap may predispose the pedicle to heterotopic ossification.MethodsA 56‐year‐old man with history of a T2N1M0 squamous cell cancer of the left tonsil who was treated with chemoradiation developed osteoradionecrosis of the mandible requiring fibula free flap reconstruction. The patient presented with a firm submandibular mass 1 year after reconstruction.ResultsImaging revealed bone along the mandible projecting to the floor of the mouth. Surgery revealed heterotopic bone along the submandibular triangle and vascular pedicle. The bone was removed and the periosteum fulgurated to prevent further proliferation.ConclusionOur practice includes a high‐volume head and neck extirpative and reconstruction practice. To the best of our knowledge, this represents the first documented case of heterotopic ossification along a free flap pedicle despite routine subperiosteal elevation to free the peroneal artery from the proximal fibula.
Early‐life exposure to Tris(1,3‐dichloroisopropyl) phosphate induces dose‐dependent suppression of sexual behavior in male rats
Authors: Kamishima Manami , Hattori Tatsuya , Suzuki Go , Matsukami Hidenori , Komine Chiaki , Horii Yasuyuki , Watanabe Gen , Oti Takumi , Sakamoto Hirotaka , Soga Tomoko , Parhar Ishwar S. , Kondo Yasuhiko , Takigami Hidetaka , Kawaguchi Maiko 
Published: December 2017

AbstractExposure to endocrine‐disrupting chemicals may adversely affect animals, particularly during development. Tris(1,3‐dichloroisopropyl) phosphate (TDCIPP) is an organophosphate with anti‐androgen function in vitro that is present in indoor dust at relatively high concentrations. In male rats, androgens are necessary for the development of reproductive organs, as well as the endocrine and central nervous systems. However, we currently do not know the exact effects of TDCIPP exposure through suckling on subsequent reproductive behavior in males. Here, we show that TDCIPP exposure (25–250 mg kg–1 via oral administration over 28 consecutive days post‐birth) suppressed male sexual behavior and reduced testes size. These changes were dose‐dependent and appeared first in adults rather than in juveniles. These results demonstrate that TDCIPP exposure led to normal body growth and appearance in juveniles, but disrupted the endocrine system and physiology in adults. Therefore, assays should be performed using adult animals to ensure accuracy, and to confirm the influence of chemical substances given during early mammalian life.
Mechanistic and structural insight into promiscuity based metabolism of cardiac drug digoxin by gut microbial enzyme
Authors: Kumar Kundan , Jaiswal Shubham K. , Dhoke Gaurao V. , Srivastava Gopal N. , Sharma Ashok K. , Sharma Vineet K. 
Published: December 2017

AbstractThe recent advances in microbiome studies have revealed the role of gut microbiota in altering the pharmacological properties of oral drugs, which contributes to patient‐response variation and undesired effect of the drug molecule. These studies are essential to guide us for achieving the desired efficacy and pharmacological activity of the existing drug molecule or for discovering novel and more effective therapeutics. However, one of the main limitations is the lack of atomistic details on the binding and metabolism of these drug molecules by gut‐microbial enzymes. Therefore, in this study, for a well‐known and important FDA‐approved cardiac glycoside drug, digoxin, we report the atomistic details and energy economics for its binding and metabolism by the Cgr2 protein of Eggerthella lenta DSM 2243. It was observed that the binding pocket of digoxin to Cgr2 primarily involved the negatively charged polar amino acids and a few non‐polar hydrophobic residues. The drug digoxin was found to bind Cgr2 at the same binding site as that of fumarate, which is the proposed natural substrate. However, digoxin showed a much lower binding energy (17.75 ± 2 Kcal mol−1) than the binding energy (42.17 ± 2 Kcal mol−1) of fumarate. This study provides mechanistic insights into the structural and promiscuity‐based metabolism of widely used cardiac drug digoxin and presents a methodology, which could be useful to confirm the promiscuity‐based metabolism of other orally administrated drugs by gut microbial enzymes and also help in designing strategies for improving the efficacy of the drugs.
Epigenetic regulation of integrin β6 transcription induced by TGF‐β1 in human oral squamous cell carcinoma cells
Authors: Xu Mingyan , Yin Liqin , Cai Yihuang , Hu Qingwei , Huang Jie , Ji Qing , Hu Yanping , Huang Wenxia , Liu Fan , Shi Songlin , Deng Xiaoling 
Published: December 2017

AbstractOverexpression of integrin αvβ6 is believed to play an important role in the invasion and metastasis of oral squamous cell carcinoma (OSCC). However, little is known about the molecular mechanisms leading to αvβ6 upregulation in OSCC. As the integrin β6 (ITGB6) is the only partner with αv, the expression of αvβ6 is dependent on ITGB6, it is, therefore, pivotal to investigate the mechanisms underlying ITGB6 overexpression in OSCC. We previously reported the cloning and characterization of human ITGB6 gene. In the current study, we further investigated the molecular mechanisms of ITGB6 expression and the upregulation by carcinogenesis related cytokine‐transforming growth factor‐β1 (TGF‐β1) in OSCC cells. We first demonstrated that TGF‐β1 can induce ITGB6 mRNA and protein express in a time and concentration dependent manner, and the induced‐ITGB6 mRNA was not due to increase the mRNA stability, but regulated at transcriptional level. By using a luciferase reporter assay, site‐mutation, RNA interference, and chromatin immunoprecipitation assay, we revealed for the first time that JunB, a member of the activator protein‐1 (AP‐1) family, is involved in the positive regulation to the ITGB6 transcription induced by TGF‐β1 in OSCC cells. Furthermore, our data also demonstrated that histone acetyltransferase (HAT) CBP mediated histone H3 and H4 hyperacetylation, and RNA Polymerase II recruitment to ITGB6 promoter, facilitated the binding of transcription factor JunB to ITGB6 promoter after TGF‐β1 stimulation. Collectively, these findings demonstrate that JunB and CBP‐mediated histone hyperacetylation are responsible for TGF‐β1 induced ITGB6 transcription in OSCC cells, suggesting that epigenetic mechanisms are responsible for the active transcription expression of ITGB6 induced by TGF‐β1 in OSCC cells.