bluuebunny/crossref_metadata_2025_split huggingface dataset:
Heterometallic Polyhydride Complexes Containing Yttrium Hydrides with Different Cp Ligands: Synthesis, Structure, and Hydrogen‐Uptake/Release Properties
Authors: Shima Takanori , Hou Zhaomin 
Published: January 2013

AbstractA new family of Y4/M2 and Y5/M heterobimetallic rare‐earth‐metal/d‐block‐transition‐metalpolyhydride complexes has been synthesized. The reactions of the tetranuclear yttriumoctahydride complex [{Cp′′Y(μ‐H)2}4(thf)4] (Cp′′=C5Me4H, 1‐C5Me4H) with one equivalent of Group‐6‐metalpentahydride complexes [Cp*M(PMe3)H5] (M=Mo, W; Cp*=C5Me5) afforded pentanuclear heterobimetallic Y4/Mpolyhydride complexes [{(Cp′′Y)4(μ‐H)7}(μ‐H)4MCp*(PMe3)] (M=Mo (2 a), W (2 b)). UV irradiation of compounds 2 a,b in THF gave PMe3‐free complexes [{(Cp′′Y)4(μ‐H)6(thf)2}(μ‐H)5MCp*] (M=Mo (3 a), W (3 b)). Compounds 3 a,b reacted with one equivalent of [Cp*M(PMe3)H5] to afford hexanuclear Y4/M2 complexes [{Cp*M(μ‐H)5}{(Cp′′Y)4(μ‐H)5}{(μ‐H)4MCp*(PMe3)}] (M=Mo (4 a), W (4 b)). UV irradiation of compounds 4 a,b provided the PMe3‐free complexes [(Cp′′Y)4(μ‐H)4{(μ‐H)5MCp*}2] (M=Mo (5 a), W (5 b)). C5Me4Et‐ligated analogue [(Cp′′Y)4(μ‐H)4{(μ‐H)5Mo(C5Me4Et)}2] (5 a′) was obtained from the reaction of 1‐C5Me4H with [(C5Me4Et)Mo(PMe3)H5]. On the other hand, the reaction of pentanuclear yttriumdecahydride complex [{(C5Me4R)Y(μ‐H)2}5(thf)2] (1‐C5Me5: R=Me; 1‐C5Me4Et: R=Et) with [Cp*M(PMe3)H5] gave the hexanuclear heterobimetallic Y5/Mpolyhydride complexes [({(C5Me4R)Y}5(μ‐H)8)(μ‐H)5MCp*] (6 a: M=Mo, R=Me; 6 a′: M=Mo, R=Et; 6 b: M=W, R=Me). Compound 5 a released two molecules of H2 under vacuum to give [(Cp′′Y)4(μ‐H)2{(μ‐H)4MoCp*}2] (7). In contrast, compound 6 a lost one molecule of H2 under vacuum to yield [{(Cp*Y)5(μ‐H)7}(μ‐H)4MoCp*] (8). Both compounds 7 and 8 readily reacted with H2 to regenerate compounds 5 a and 6 a, respectively. The structures of compounds 4 a, 5 a′, 6 a′, 7, and 8 were determined by single‐crystal X‐ray diffraction.
Cooperative transmissions for secondary spectrum access in cognitive radios
Authors: Dai Zeyang , Liu Jian , Long Keping 
Published: January 2013

SUMMARYIn cognitive radio networks (CRNs), the primary users (PUs) and secondary users (SUs) will interfere with each other, which may severely degrade the performances of both primary and secondary transmissions. In this paper, we propose a two‐phase cognitive transmission (TCT) protocol for secondary spectrum access in CRNs, aiming at improving the secondary transmission performance while guaranteeing the quality‐of‐service (QoS) of primary transmissions. In TCT protocol, SUs gain the opportunities to access the licensed spectrum through assisting primary transmissions using superposition coding (SC), where SUs limit their transmit power to satisfy a given primary QoS requirement and also employ interference cancelation technique to mitigate the interference from PUs. Under the constraint of satisfying a required primary outage probability, we derive the closed‐form expressions of secondary outage probabilities over Rayleigh fading channels for proposed TCT protocol. Numerical and simulation results reveal that, with a guaranteed primary outage probability, TCT achieves better secondary transmission performance than traditional case. Copyright © 2013 John Wiley & Sons, Ltd.
Adaptive responses and invasion: the role of plasticity and evolution in snail shell morphology
Authors: Kistner Erica J. , Dybdahl Mark F. 
Published: January 2013

AbstractInvasive species often exhibit either evolved or plastic adaptations in response to spatially varying environmental conditions. We investigated whether evolved or plastic adaptation was driving variation in shell morphology among invasive populations of the New Zealand mud snail (Potamopyrgus antipodarum) in the western United States. We found that invasive populations exhibit considerable shell shape variation and inhabit a variety of flow velocity habitats. We investigated the importance of evolution and plasticity by examining variation in shell morphological traits 1) between the parental and F1 generations for each population and 2) among populations of the first lab generation (F1) in a common garden, full‐sib design using Canonical Variate Analyses (CVA). We compared the F1 generation to the parental lineages and found significant differences in overall shell shape indicating a plastic response. However, when examining differences among the F1 populations, we found that they maintained among‐population shell shape differences, indicating a genetic response. The F1 generation exhibited a smaller shell morph more suited to the low‐flow common garden environment within a single generation. Our results suggest that phenotypic plasticity in conjunction with evolution may be driving variation in shell morphology of this widespread invasive snail.
Heterobimetallic Sodium–Lithium Based Metal–Organic Framework Showing the β‐Cristobalite Topology and Having High Permanent Porosity
Authors: Frigoli Michel , El Osta Racha , Marrot Jérôme , Medina Manuela E. , Walton Richard I. , Millange Franck 
Published: January 2013

AbstractThe solvothermal synthesis of a novel mixed‐s‐block metal–organic framework is described, with crystallization brought about by use of the sodium salt of the benzo‐(1,2;3,4;5,6)‐tris(thiophene‐2′‐carboxylate) linker in combination with a lithium salt. The structure of the material was determined by single‐crystal X‐ray diffraction, which reveals an expanded version of the β‐cristobalite topology, with supertetrahedral building units made up of clusters of sodium and lithium ions. Outgassing under vacuum gives permanent porosity to the solid structure with a BET surface area of 1191 m2 g–1 measured by nitrogen adsorption.
Organic carbon export in the form of wood during an extreme tropical storm, Upper Rio Chagres, Panama
Authors: Wohl Ellen , Ogden Fred L. 
Published: January 2013

ABSTRACTWidespread, intense rainfall over the Upper Rio Chagres watershed (414 km2) in central Panama during December 2010 triggered numerous landslides that introduced large numbers of trees to the river network. We flew by helicopter along the mainstem Upper Chagres and the adjacent margins of Lake Alhajuela, into which the Upper Chagres flows, in February and June 2011. We used low‐elevation video photography from these flights to tally the number of wood pieces stored along the lake margin and within the channel, and the number of landslides reaching the mainstem. We used these tallies with ground‐verified estimates of average wood piece size and landslide surface area, and assumptions about wood density, carbon content, and aboveground biomass, to develop a first‐order estimate of carbon export in the form of wood from the Upper Chagres following the 2010 storms. Based on the wood tally, we estimate 9 · 6 to 16 Mg C/km2export, and from the landslide tally we estimate 24 Mg C/km2. We believe the landslide tally provides a more accurate minimum estimate of carbon export from the Upper Chagres during the December 2010 storms. These values are an order of magnitude higher than limited data for average or background rates of wood‐based carbon export from other catchments, but two orders of magnitude lower than wood‐based carbon export during extreme storms in Taiwan. The findings suggest that duration of flood flow above a threshold for mobilizing wood within the channel network exerts a more important control on wood export from the Upper Chagres than magnitude of flood peak. Copyright © 2013 John Wiley & Sons, Ltd.
Effect of mesenchymal stem cells on inhibiting airway remodeling and airway inflammation in chronic asthma
Authors: Ge Xiahui , Bai Chong , Yang Jianming , Lou Guoliang , Li Qiang , Chen Ruohua 
Published: January 2013

AbstractPrevious studies proved that bone marrow‐derived mesenchymal stem cells (BMSCs) could improve a variety of immune‐mediated disease by its immunomodulatory properties. In this study, we investigated the effect on airway remodeling and airway inflammation by administrating BMSCs in chronic asthmatic mice. Forty‐eight female BALB/c mice were randomly distributed into PBS group, BMSCs treatment group, BMSCs control group, and asthmatic group. The levels of cytokine and immunoglobulin in serum and bronchoalveolar lavage fluid were detected by enzyme‐linked immunosorbent assay. The number of CD4+CD25+regulatory T cells and morphometric analysis was determined by flow cytometry, hematoxylin‐eosin, immunofluorescence staining, periodic‐acid Schiff, and masson staining, respectively. We found that airway remodeling and airway inflammation were evident in asthmatic mice. Moreover, low level of IL‐12 and high levels of IL‐13, IL‐4, OVA‐specific IgG1, IgE, and IgG2a and the fewer number of CD4+CD25+regulatory T cells were present in asthmatic group. However, transplantation of BMSCs significantly decreased airway inflammation and airway remodeling and level of IL‐4, OVA‐specific IgE, and OVA‐specific IgG1, but elevated level of IL‐12 and the number of CD4 + CD25 + regulatory T cells in asthma (P < 0.05). However, BMSCs did not contribute to lung regeneration and had no significant effect on levels of IL‐10, IFN‐Y, and IL‐13. In our study, BMSCs engraftment prohibited airway inflammation and airway remodeling in chronic asthmatic group. The beneficial effect of BMSCs might involved the modulation imbalance cytokine toward a new balance Th1–Th2 profiles and up‐regulation of protective CD4 + CD25 + regulatory T cells in asthma, but not contribution to lung regeneration. J. Cell. Biochem. 114: 1595–1605, 2013. © 2013 Wiley Periodicals, Inc.
The influence of pregnancy on heterotopic ossification post‐displaced acetabular fractures surgical repair
Authors: Mourad Waleed F. , Packianathan Satya , Shourbaji Rania A. , Jennelle Richard , Yang Claus (Chunli) , Mobit Paul , Zhang Zhen , Khan Majid A. , Graves Mathew , Russell George , Vijayakumar Srinivasan 
Published: January 2013

AbstractPregnancy is associated with maternal bone mineral density loss and modulation of calcium metabolism. We hypothesized that pregnancy may decrease the risk of heterotopic ossification (HO) after trauma. This is a single‐institution, University of Mississippi Medical Center, retrospective study investigating the effect of pregnancy on the incidence HO after surgical repair (SR) of displaced acetabular fractures. Between January 1998 and 2010, 257 non‐pregnant women (Group A) and 16 pregnant women (Group B) were identified. All the non‐pregnant women received radiation therapy (RT) ± indomethacin. None of the pregnant women in group B received any prophylaxis. After a median follow‐up of 6.6 years the incidence of HO in all patients was 27% (75/273). In Group A, non‐pregnant, women who received RT ± indomethacin, 29% developed HO; HO risk was 0.4. In Group B, 16 pregnant patients, only one developed HO (6%); HO risk was 0.06. Thus, the risk of HO appears to be nearly six‐fold higher in non‐pregnant women despite prophylactic RT ± indomethacin. Our data suggest that pregnancy may be associated with a reduced risk of HO after SR of displaced acetabular fractures. Further analysis with a larger pregnant patient sample is necessary to confirm this finding. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31: 944–948, 2013
Dual Nucleophilic Substitution Reactions of O,O‐Diethyl 2,4‐dinitrophenyl Phosphate and Thionophosphate Triesters
Authors: Aguayo Raul , Arias Felipe , Cañete Alvaro , Zuñiga Carolina , Castro Enrique A. , Pavez Paulina , Santos José G. 
Published: January 2013

AbstractThe reactions of the title compounds with phenoxides, secondary alicyclic (SA) amines, and pyridines, in 44 wt% ethanol–water, at 25°C and an ionic strength of 0.2 M, were subjected to kinetic and product studies. From analytical techniques (HPLC and NMR), two pathways were detected (nucleophilic attack at the phosphoryl center and at the C‐1 aromatic carbon) for the reactions of all the nucleophiles with the phosphate (2) and for the pyridinolysis of the thionophosphate (1). Only aromatic nucleophilic substitution was found for the reactions of 1 with phenoxides and SA amines. For the dual reactions, the nucleophilic rate constants (kN) were separated in two terms: \documentclass{article}\usepackage{amssymb}\pagestyle{empty}\begin{document}$k_{\rm N}^{\rm P}$\end{document} and \documentclass{article}\usepackage{amssymb}\pagestyle{empty}\begin{document}$k_{\rm N}^{{\rm Ar}}$\end{document}, which are the rate constants for the corresponding electrophilic centers. The absence of a break in the Brønsted‐type plots for the attack at P is consistent with concerted mechanisms. The Brønsted slopes, βAr 0.32–0.71, for the attack at the aromatic C‐1, are in agreement with stepwise mechanisms where formation of a Meisenheimer complex is the rate‐determining step. © 2013 Wiley Periodicals, Inc. Int J Chem Kinet 45: 202–211, 2013
The downside of ‘inappropriate messaging’: new insight into the development of testicular germ cell tumours in young men?
Authors: Sharpe Richard M , Mitchell Rod T 
Published: January 2013

AbstractHow invasive testicular germ cell tumours (TGCTs) develop from precursor carcinoma in situ/intratubular germ cell neoplasia unclassified (CIS/IGCNU) cells, and only after puberty, is unknown. In the current issue of The Journal of Pathology, Jørgensen and colleagues have compared the protein expression profile of CIS before and after puberty and in pre‐invasive versus invasive TGCT and show that the mitosis–meiosis controller DMRT1 switches off in CIS cells postpubertally and is associated with invasiveness. They also show that CIS cells express a ‘confusing’ mix of pro‐ and anti‐meiotic proteins; this may predispose CIS cells to accumulate extra chromosomal material which ultimately leads to tumourigenesis.
GDF15‐mediated upregulation of ferroportin plays a key role in the development of hyperferritinemia in children with hemophagocytic lymphohistiocytosis
Authors: Wu Jian‐Rong , Yuan Li‐Xing , Ma Zhi‐Gui , Chen Xiao‐Xi , Gu Ling , Gao Ju 
Published: January 2013

AbstractBackgroundGrowth differentiation factor 15 (GDF15), a divergent TGFβ superfamily, has recently been implicated in the modulation of iron homeostasis, acting as an upstream negative regulator of hepcidin, the key iron regulatory hormone produced primarily by hepatocytes. However, little is known about possible roles that GDF15 might play in the regulation of iron homeostasis and development of hyperferritinemia in children with hemophagocytic lymphohistiocytosis (HLH).ProceduresWe compared serum GDF15 level and mRNA expressions of GDF15 and key molecules of iron metabolism, and made correlations between their expressions in children with HLH and control children.ResultsSerum GDF15 level was remarkably higher in HLH group than that in controls, with median serum concentration of 1,700 and 260 pg/ml, respectively (P < 0.001). In addition, GDF15 mRNA was significantly upregulated but independent of hypoxia‐inducible factor‐mediated oxygen signaling pathway. More importantly, GDF15 induction was positively correlated to upregulation of ferroportin, the only cellular iron exporter, and to upregulation of ferritin heavy chain.ConclusionsOur study suggests that GDF15 induction helps suppress further activation of macrophages in stressful physiologic states as HLH, and is intimately implicated in the development of hyperferritinemia by modulating the hepcidin–ferroportin axis, resulting in enhanced ferroportin‐mediated iron efflux. Pediatr Blood Cancer 2013; 60: 940–945. © 2013 Wiley Periodicals, Inc.
The first step to integrating the child's voice in adverse event reporting in oncology trials: A content validation study among pediatric oncology clinicians
Authors: Reeve Bryce B. , Withycombe Janice S. , Baker Justin N. , Hooke Mary C. , Lyons Jessica C. , Mowbray Catriona , Wang Jichuan , Freyer David R. , Joffe Steven , Sung Lillian , Tomlinson Deborah , Gold Stuart H. , Hinds Pamela S. 
Published: January 2013

AbstractPurposeChildren with cancer experience significant toxicities while undergoing treatment. Documentation of adverse events (AEs) in clinical trials is mandated by federal agencies. Although many AEs are subjective, the current standard is clinician reporting. Our long‐term goal is to create and validate a self‐report measure of subjective AEs for children aged 7 years and older that will inform AE reporting for the National Cancer Institute's Common Terminology Criteria for Adverse Events (CTCAE). This content validation study aimed to identify which of the AEs in the current CTCAE should be included in a pediatric self‐report measure.MethodsWe sought expert panel review and consensus among 187 pediatric clinicians from seven Children's Oncology Group institutions to determine which of the 790 AEs are amenable to child self‐report. Two survey iterations were used to identify suitable AEs, and clinician agreement estimated by the content‐validity ratio (CVR) was assessed.ResultsResponse rates for surveys 1 and 2 were 72% and 67%, respectively. After the surveys, 64 CTCAE terms met the criteria of being subjective, relevant for use in pediatric cancer trials, and amenable to self‐report by a child. The most frequent reasons for removal of CTCAE terms were that they relied on laboratory or clinical measures or were not applicable to children.ConclusionThe 64 CTCAE terms will be translated into child‐friendly terms as the basis of the child‐report toxicity measure. Ultimately, systematic collection of these data will improve care by enhancing the accuracy and completeness of treatment toxicity reports for childhood cancer. Pediatr Blood Cancer 2013; 60: 1231–1236. © 2013 Wiley Periodicals, Inc.
Early negative minimal residual disease in bone marrow after immunotherapy is less predictive of late or non‐marrow relapse among patients with high‐risk stage 4 neuroblastoma
Authors: Cheung Irene Y. , Feng Yi , Cheung Nai‐Kong V. 
Published: January 2013

AbstractMolecular detection of minimal residual disease (MRD) measured by quantitative reverse transcription‐polymerase chain reaction using a four‐marker panel in the bone marrow (BM) after only two treatment cycles of anti‐GD2 immunotherapy was a strong independent outcome predictor among high‐risk patients with stage 4 neuroblastoma in first remission. While 32 of 46 MRD‐negative patients relapsed within 2 years from immunotherapy, only four had marrow relapse; in three of these four patients, MRD turned positive in the subsequent BM. We conclude that negative MRD in the post‐cycle two BM was rarely associated with BM relapse, but it did not exclude recurrences at other sites. Pediatr Blood Cancer 2013; 60: E32–E34. © 2013 Wiley Periodicals, Inc.
A broad specificity nucleoside kinase from Thermoplasma acidophilum
Authors: Elkin Sarah R. , Kumar Abhinav , Price Carol W. , Columbus Linda 
Published: January 2013

AbstractThe crystal structure of Ta0880, determined at 1.91 Å resolution, from Thermoplasma acidophilum revealed a dimer with each monomer composed of an α/β/α sandwich domain and a smaller lid domain. The overall fold belongs to the PfkB family of carbohydrate kinases (a family member of the Ribokinase clan) which include ribokinases, 1‐phosphofructokinases, 6‐phosphofructo‐2‐kinase, inosine/guanosine kinases, fructokinases, adenosine kinases, and many more. Based on its general fold, Ta0880 had been annotated as a ribokinase‐like protein. Using a coupled pyruvate kinase/lactate dehydrogenase assay, the activity of Ta0880 was assessed against a variety of ribokinase/pfkB‐like family substrates; activity was not observed for ribose, fructose‐1‐phosphate, or fructose‐6‐phosphate. Based on structural similarity with nucleoside kinases (NK) from Methanocaldococcus jannaschii (MjNK, PDB 2C49, and 2C4E) and Burkholderia thailandensis (BtNK, PDB 3B1O), nucleoside kinase activity was investigated. Ta0880 (TaNK) was confirmed to have nucleoside kinase activity with an apparent KM for guanosine of 0.21 μM and catalytic efficiency of 345,000 M−1s−1. These three NKs have significantly different substrate, phosphate donor, and cation specificities and comparisons of specificity and structure identified residues likely responsible for the nucleoside substrate selectivity. Phylogenetic analysis identified three clusters within the PfkB family and indicates that TaNK is a member of a new sub‐family with broad nucleoside specificities. Proteins 2013. © 2012 Wiley Periodicals, Inc.
Validation of the Laparoscopically Stapled Approach as a Standard Technique for Left Lateral Segment Liver Resection
Authors: Wang Xuedong , Li Jianwei , Wang Hongguang , Luo Ying , Ji Wenbin , Duan Weidong , Zhang Xuan , Guo Sen , Xu Kesen , Dong Jiahong , Zheng Shuguo 
Published: January 2013

AbstractBackgroundLeft lateral sectionectomy (LLS) is the most common type of anatomic laparoscopic liver resection performed, accounting for 20 % of all laparoscopic hepatectomies. Because there has been no standardized surgical technique for laparoscopic left lateral sectionectomy (LLLS), we offer an established operation: laparoscopically stapled left lateral sectionectomy (LSLLS). Our aim was to perform a case‐controlled study of LSLLS with traditional (without vascular staplers) laparoscopic left lateral sectionectomy (TLLLS), validating the standardization and reproducibility of LSLLS.MethodsFrom February 2009 to December 2011, a total of 49 LSLLSs were performed. The results were compared with 33 cohort‐matched TLLLSs from an earlier time period. Ordered sample cluster analysis was used to determine the learning curve of LSLLS based on the operating time and blood loss.ResultsAll LSLLS were performed successfully. There were no conversions to laparotomy or hand‐assisted laparoscopic resection. Two endoscopic linear staplers were used in each case. Despite a higher hospital cost ($10,892 ± $944 vs. $8,962 ± $943, p < 0.05), LSLLS compared favorably with TLLLS regarding operating time (103 ± 21 vs. 151 ± 32 min, p < 0.05) and blood loss (70.8 ± 41.6 vs. 173.3 ± 131.1 ml, p < 0.05). No specific complications related to laparoscopy were observed. Ordered sample cluster analysis demonstrated a learning curve of 18 cases for LSLLS.ConclusionsThis study demonstrates the standardization and reproducibility of LSLLS. We therefore propose LSLLS as the standard technique for lesions located in the left lateral section of the liver.
Using high-performance quantitative NMR (HP-qNMR®) for certifying traceable and highly accurate purity values of organic reference materials with uncertainties <0.1 %
Authors: Weber Michael , Hellriegel Christine , Rück Alex , Sauermoser Robert , Wüthrich Jürg 
Published: January 2013

Abstract
Quantitative nuclear magnetic resonance (qNMR) in combination with metrological weighing is optimised to demonstrate the power of the qNMR measurement method. It is shown that with 1H-qNMR it is possible to certify the purity of organic reference materials (expressed as mass fraction) with relative expanded uncertainties of <0.1 % for a 95 % confidence interval (k = 2). Following well-defined selection criteria, a set of twelve different chemical compounds is evaluated and certified to serve as internal references for 1H-qNMR measurements. A series of comparison measurements is made amongst a subset of the selected compounds. The purity of maleic acid is determined by six different 1H-qNMR measurement series, and all results show full consistency. All the six mean values are covered within the range of ±0.05 %. In two more measurement series, four different nuclei are analysed within the same sample against one calibrator. Even with non-optimised signal intensity ratios and varying signal pattern, a high consistency was obtained. Therefore, the validity and robustness of 1H-qNMR measurement results are demonstrated. 1H-qNMR measurement results are directly traceable to a variety of internationally accepted primary reference materials, and therefore, traceability to SI units is obtained. All experiments are performed under ISO/IEC 17025 and ISO Guide 34 accreditation.