bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and Structural Characterization of Zinc Complexes that Contain Chelating Phenolate Phosphane Ligands
Authors: Liang Lan‐Chang , Shih Huan‐Yu , Chen Han‐Sheng , Lin Sheng‐Ta 
Published: December 2011

AbstractThe preparation and characterization of zinc complexes supported by potentially tridentate biphenolate phosphane ligands are reported. The in situ prepared dilithium complexes of 2,2′‐tert‐butylphosphanylbis(4,6‐di‐tert‐butylphenolate) ([LtBu]2–) and 2,2′‐phenylphosphanylbis(4,6‐di‐tert‐butylphenolate) ([LPh]2–) react with ZnCl2 in tetrahydrofuran (THF) to produce lithium zincates Zn[LtBuLi(THF)]2 and Zn[LPhLi(THF)]2, respectively, regardless of the stoichiometry of the starting materials. Alkane elimination reactions of ZnEt2 with one equiv. of H2LtBu or H2LPh in THF generate Zn2(LtBu)2(THF) or Zn2(LPh)2(THF)2, whereas those employing two equiv. of the protio ligands afford Zn(LtBuH)2(MeCN) or Zn(LPhH)2(MeCN), respectively. The X‐ray structures of Zn[LtBuLi(THF)]2, Zn2(LtBu)2(THF), Zn2(LPh)2(THF)2, and Zn(LtBuH)2(MeCN) are presented.
The N,N‐Bis(terphenyl)aminophosphenium Cation – A Sensitive Probe for Interactions with Different Anions
Authors: Reiß Fabian , Schulz Axel , Villinger Alexander 
Published: December 2011

AbstractA series of salts that contain the terphenyl‐substitutedbis(amino)phosphenium cation with different anions (F–,Cl–, [CF3CO2]–, [CF3SO3]–, [B(C6F5)4]–, [GaCl4]–, [SbF6]–, [Al{OCH(CF3)2}4]– and [CHB11H5Br6]–) has been prepared by different synthetic protocols. All of the products have been characterised spectroscopically and by single‐crystal X‐ray diffraction studies. A detailed analysis of the interionic interactions and their influence on the molecular structure of the phosphenium cation reveals a strong dependence on the capability of the anion to enter the pocket generated by the bulky terphenyl substituents.
Stereo‐Inversion in the (4R)‐γ‐Decanolactone Synthesis by Saccharomyces cerevisiae: (2E,4S)‐4‐Hydroxydec‐2‐enoic Acid Acts as a Key Intermediate
Authors: Köhler Gunnar , Evans Paul , Garbe Leif‐Alexander 
Published: December 2011

AbstractMethyl (2E,4R)‐4‐hydroxydec‐2‐enoate, methyl (2E,4S)‐4‐hydroxydec‐2‐enoate, and ethyl (±)‐(2E)‐4‐hydroxy[4‐2H]dec‐2‐enoate were chemically synthesized and incubated in the yeast Saccharomyces cerevisiae. Initial C‐chain elongation of these substrates to C12 and, to a lesser extent, C14 fatty acids was observed, followed by γ‐decanolactone formation. Metabolic conversion of methyl (2E,4R)‐4‐hydroxydec‐2‐enoate and methyl (2E,4S)‐4‐hydroxydec‐2‐enoate both led to (4R)‐γ‐decanolactone with >99% ee and 80% ee, respectively. Biotransformation of ethyl (±)‐(2E)‐4‐hydroxy(4‐2H)dec‐2‐enoate yielded (4R)‐γ‐[2H]decanolactone with 61% of the 2H label maintained and in 90% ee indicating a stereoinversion pathway. Electron‐impact mass spectrometry analysis (Fig. 4) of 4‐hydroxydecanoic acid indicated a partial C(4)→C(2) 2H shift. The formation of erythro‐3,4‐dihydroxydecanoic acid and erythro‐3‐hydroxy‐γ‐decanolactone from methyl (2E,4S)‐4‐hydroxydec‐2‐enoate supports a net inversion to (4R)‐γ‐decanolactone via 4‐oxodecanoic acid. As postulated in a previous work, (2E,4S)‐4‐hydroxydec‐2‐enoic acid was shown to be a key intermediate during (4R)‐γ‐decanolactone formation via degradation of (3S,4S)‐dihydroxy fatty acids and precursors by Saccharomyces cerevisiae.
Evidence for a dual function of EphB4 as tumor promoter and suppressor regulated by the absence or presence of the ephrin‐B2 ligand
Authors: Rutkowski Raphael , Mertens‐Walker Inga , Lisle Jessica E. , Herington Adrian C. , Stephenson Sally‐Anne 
Published: December 2011

AbstractOverexpression of the receptor tyrosine kinase EphB4 is common in epithelial cancers and linked to tumor progression by promoting angiogenesis, increasing survival and facilitating invasion and migration. However, other studies have reported loss of EphB4 suggesting a tumor suppressor function in some cancers. These opposing roles may be regulated by (i) the presence of the primary ligand ephrin‐B2 that regulates pathways involved in tumor suppression or (ii) the absence of ephrin‐B2 that allows EphB4 signaling via ligand‐independent pathways that contribute to tumor promotion. To explore this theory, EphB4 was overexpressed in the prostate cancer cell line 22Rv1 and the mammary epithelial cell line MCF‐10A. Overexpressed EphB4 localized to lipid‐rich regions of the plasma membrane and confirmed to be ligand‐responsive as demonstrated by increased phosphorylation of ERK1/2 and internalization. EphB4 overexpressing cells demonstrated enhanced anchorage‐independent growth, migration and invasion, all characteristics associated with an aggressive phenotype, and therefore supporting the hypothesis that overexpressed EphB4 facilitates tumor promotion. Importantly, these effects were reversed in the presence of ephrin‐B2 which led to a reduction in EphB4 protein levels, demonstrating that ligand‐dependent signaling is tumor suppressive. Furthermore, extended ligand stimulation caused a significant decrease in proliferation that correlated with a rise in caspase‐3/7 and ‐8 activities. Together, these results demonstrate that overexpression of EphB4 confers a transformed phenotype in the case of MCF‐10A cells and an increased metastatic phenotype in the case of 22Rv1 cancer cells and that both phenotypes can be restrained by stimulation with ephrin‐B2, in part by reducing EphB4 levels.
Effects of four types of hydroxyapatite nanoparticles with different nanocrystal morphologies and sizes on apoptosis in rat osteoblasts
Authors: Xu Zhengli , Liu Changsheng , Wei Jie , Sun Jiao 
Published: December 2011

ABSTRACTHydroxyapatite nanoparticles (nano‐HAP) have been reported to cause inflammatory reactions. Here, we aimed to compare the effects of four types of nano‐HAP with different nanocrystal morphologies (short rod‐like, long rod‐like, spherical or needle‐shaped crystals) and sizes (10–20, 10–30 or 20–40 nm) on growth inhibition and apoptosis in primary cultured rat osteoblasts. The osteoblasts was treated with the four types of nano‐HAP at various concentrations (20, 40, 60, 80 or 100 mg l−1). The nano‐HAP specific surface area was detected using the Brunauer, Emmet and Teller method. The cell growth rate was detected using the 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide assay; apoptotic alterations and the level of reactive oxygen species in osteoblasts were measured using flow cytometry; and the amounts of apoptotic p53 and cytochrome c proteins were measured using western blotting. We observed that all four types of nano‐HAP inhibited the growth of osteoblasts in a dose‐dependent manner. These nano‐HAP significantly induced apoptosis in osteoblasts. Nano‐HAP with smaller specific surface areas induced lower apoptosis rates. The needle‐shaped and the short rod‐like particles induced greater cellular injury than the spherical and long rod‐like particles, respectively. The increased apoptosis rates were accompanied by increased p53 and cytochrome c expression. These findings indicate that nano‐HAP inhibit the activity of osteoblasts and also induce the apoptosis of osteoblasts in vitro. These findings also suggest that the nano‐HAP‐induced apoptotic pathway is mediated by a mitochondrial‐dependent pathway. Moreover, the sizes, morphologies and concentrations of nano‐HAP have significant effects on the apoptotic level. Copyright © 2011 John Wiley & Sons, Ltd.
Changes in 3-dimensional bone structure indices in hypoparathyroid patients treated with PTH(1-84): A randomized controlled study
Authors: Sikjaer Tanja , Rejnmark Lars , Thomsen Jesper Skovhus , Tietze Anna , Brüel Annemarie , Andersen Gratien , Mosekilde Leif 
Published: December 2011

Abstract
Hypoparathyroidism (hypoPT) is characterized by a state of low bone turnover and high bone mineral density (BMD) despite conventional treatment with calcium supplements and active vitamin D analogues. To assess effects of PTH substitution therapy on 3-dimensional bone structure, we randomized 62 patients with hypoPT into 24 weeks of treatment with either PTH(1-84) 100 µg/day subcutaneously or similar placebo as an add-on therapy. Micro-computed tomography was performed on 44 iliac crest bone biopsies (23 on PTH treatment) obtained after 24 weeks of treatment. Compared with placebo, PTH caused a 27% lower trabecular thickness (p &lt; 0.01) and 4% lower trabecular bone tissue density (p &lt; 0.01), whereas connectivity density was 34% higher (p &lt; 0.05). Trabecular tunneling was evident in 11 (48%) of the biopsies from the PTH group. Patients with tunneling had significantly higher levels of biochemical markers of bone resorption and formation. At cortical bone, number of Haversian canals per area was 139% higher (p = 0.01) in the PTH group, causing a tendency toward an increased cortical porosity (p = 0.09). At different subregions of the hip, areal BMD (aBMD) and volumetric BMD (vBMD), as assessed by dual-energy X-ray absorptiometry (DXA) and quantitative computed tomography (QCT), decreased significantly by 1% to 4% in the PTH group. However, at the lumbar spine, aBMD decreased by 1.8% (p &lt; 0.05), whereas vBMD increased by 12.8% (p = 0.02) in the PTH compared with the placebo group. © 2012 American Society for Bone and Mineral Research.
p‐Aminophenol‐induced cytotoxicity in Jurkat T Cells: Protective effect of 2(RS)‐n‐propylthiazolidine‐4(R)‐carboxylic acid
Authors: Chang Weiyuan , Barve Shrish , Chen Theresa S. 
Published: December 2011

AbstractAcetaminophen (APAP) is hepatotoxic and can cause toxicity in Jurkat T cells. p‐Aminophenol (PAP), an industrial chemical and APAP metabolite, is nephrotoxic and hepatotoxic. Its potential toxicity in Jurkat T cells was investigated. PAP (10–250 µM) caused toxicity (decreased survival and increased LDH activity in incubation medium) and GSH depletion. At a concentration of 100 µM but not 250 µM, PAP increased DNA fragmentation. It decreased p‐Akt levels (Elisa) and at higher concentrations decreased p‐Akt expression (Western blotting). It had no effect on FasL expression. The cysteine precursor 2(RS)‐n‐propylthiazolidine‐4(R)‐carboxylic acid (250 µM) attenuated the PAP (100 µM)‐induced decrease in viability and prevented GSH depletion and increased DNA fragmentation. It attenuated the PAP‐induced decrease in p‐Akt levels and protected against the decrease in p‐Akt expression. The results demonstrate PAP‐induced toxicity and suggest that it is due at least in part to apoptosis and involves GSH depletion and p‐Akt inactivation. © 2011 Wiley Periodicals, Inc. J Biochem Mol Toxicol 26:71–78 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/jbt.20402
Virtual screening for compounds that mimic protein–protein interface epitopes
Authors: Geppert Tim , Reisen Felix , Pillong Max , Hähnke Volker , Tanrikulu Yusuf , Koch Christian P. , Perna Anna Maria , Perez Tatiana Batista , Schneider Petra , Schneider Gisbert 
Published: December 2011

AbstractModulation of protein–protein interactions (PPI) has emerged as a new concept in rational drug design. Here, we present a computational protocol for identifying potential PPI inhibitors. Relevant regions of interfaces (epitopes) are predicted for three‐dimensional protein models and serve as queries for virtual compound screening. We present a computational screening protocol that incorporates two different pharmacophore models. One model is based on the mathematical concept of autocorrelation vectors and the other utilizes fuzzy labeled graphs. In a proof‐of‐concept study, we were able to identify serine protease inhibitors using a predicted trypsin epitope as query. Our virtual screening framework may be suited for rapid identification of PPI inhibitors and suggesting bioactive tool compounds. Copyright for JCC Journal: © 2011 Wiley Periodicals, Inc. J Comput Chem, 2011
Back‐scattered electron imaging for leakage analysis of four retrofilling materials
Authors: Chittoni Simone Bücker , Martini Tassiana , Wagner Márcia Helena , Da Rosa Ricardo Abreu , Cavenago Bruno Cavalini , Duarte Marco Antônio Húngaro , Klein Celso Afonso , Só Marcus Vinícius Reis 
Published: December 2011

AbstractThis study aimed to evaluate, ex vivo, the nanoleakage in dentinal tubules, the linear infiltration of silver nitrate in the dentin wall/root‐end filling material interface, and the presence of gaps in this interface in root‐end cavities filled with 4 filling materials. Forty‐eight disto‐buccal root canals of maxillary molars were instrumented and filled. Retrograde cavities were prepared with ultrasonic points (apical 2 mm). The samples were divided into 2 control groups (n = 4) and 4 experimental groups (n = 10): Group I – white mineral trioxide aggregate (MTA); Group II – Super EBA; Group III – Portland cement; and Group IV – Sealer 26. After 1 week, the specimens were subjected to silver nitrate and prepared for SEM (backscattered electrons). In the apical‐apical segment, an area with significantly higher leakage was observed for Super EBA, followed by Portland cement, MTA, and Sealer 26 (P = 0.0054). In the medium and cervical segments, all materials showed the same leakage behavior (P = 0.1815 and P = 0.1723, respectively). The linear infiltration at the dentin wall/root‐end filling material interface was higher with Super EBA than the other groups. No differences in the percentage of gaps along the 3 mm of dentin wall/root‐end filling material interface between the 4 materials were evident (P > 0.05). Nanoleakage occurred mainly in the apical segment of the samples, and Super EBA showed the highest values. The area and linear leakage were lower in the middle and coronal segments, regardless of the root‐end filling material. No material perfectly sealed the root‐end cavities, which allowed for the leakage occurrence. Microsc. Res. Tech. 75:796–800, 2012. © 2011 Wiley Periodicals, Inc.
Effect of atorvastatin on the cortical bones of corticosteroid treated rabbits
Authors: Handal John A. , John Thomas K. , Goldstein Daniel T. , Khurana Jasvir S. , Saing Minn , Braitman Leonard E. , Samuel Solomon P. 
Published: December 2011

AbstractOsteoporosis (“secondary” osteoporosis) and avascular necrosis (AVN) of the femoral head are well‐known adverse effects of corticosteroid therapy. Statins have been reputed to increase bone strength and bone density. In this study, we evaluated the effect of atorvastatin calcium on the flexural properties (3‐point bending strength and modulus) of corticosteroid (methylprednisolone acetate) treated rabbit femurs and tibias. Our study hypothesis was that the use of statins would counteract the loss of bone strength caused by corticosteroid treatment. The 40 rabbits were divided into 5 groups: control, corticosteroid alone and corticosteroid combined with oral doses of atorvastatin calcium (2, 10, or 20 mg/day). A daily oral dose of atorvastatin calcium treatment for 70 days weakened the long bones of methylprednisolone acetate treated rabbits irrespective of the dosage (2, 10, or 20 mg). Cortical bone strength was assessed using the 3‐point bending test at the end of the study period. A daily oral dose of atorvastatin calcium did not attenuate the loss of cortical bone strength caused by corticosteroid treatment in rabbits. It appeared to decrease that bone strength. If these results hold true in humans, they would have wide applicability given the frequent combined use of corticosteroids and statins in many patients. © 2011 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 30:872–876, 2012
Design of online solid phase extraction‐liquid chromatography‐tandem mass spectrometry (SPE‐LC‐MS/MS) hyphenated systems for quantitative analysis of small organic compounds in biological matrices
Authors: Kuklenyik Zsuzsanna , Calafat Antonia M. , Barr John R. , Pirkle James L. 
Published: December 2011

AbstractThree online solid phase extraction‐liquid chromatography‐tandem mass spectrometry (SPE‐LC‐MS/MS) method examples are presented where two different types of chromatographic columns or solvent systems were coupled to meet specific analytical objectives: (i) SPE of target analytes by restricted access media from high ionic strength urine matrix was coupled with reversed phase LC‐MS/MS conditions accommodating high ionization potentials of the analytes (urinary bisphenol A and other phenolic derivatives); (ii) strong cation exchange SPE of analytes of diverse polarity and pKa was coupled with reversed phase LC‐MS/MS analysis (urinary atrazine metabolites); (iii) pre‐concentration of low pg per sample analytes by weak anion exchange SPE was hyphenated with ion pair LC‐MS analysis (intracellular nucleotide triphosphate analogs). With these examples we suggest a conductive generic work flow for the development of online SPE‐LC‐MS methods and show how advanced commercial LC devices and software allow for the design of complex yet highly versatile analytical separation systems suited to the unique physicochemical properties of the target analytes.
The economic value of publicly accessible deer hunting land
Authors: Knoche Scott , Lupi Frank 
Published: December 2011

AbstractAccess to lands for hunting is widely recognized as critical to sustaining and developing participation in hunting. Deer hunters comprise a substantial portion of recreational hunters in the United States, and numerous stakeholders benefit from the deer management services provided by hunters on public lands. We estimated the economic value of publicly accessible deer hunting land in Michigan using economic models of hunting destinations for hunters in the archery season and for hunters in the firearm season. We found that the amounts of state‐owned hunting land, federally owned hunting land, and publicly accessible, privately owned Commercial Forest Act land are significant (P < 0.001) and positive determinants of hunting destinations. The annual economic value of Michigan's publicly accessible hunting land to archery and firearm deer hunters, beyond hunter expenditures, was estimated to be over $80 million. Access to state‐owned land accounted for approximately $50 million in annual economic value to Michigan deer hunters. The average per‐acre value of publicly accessible hunting land is greatest in the Southern Lower Peninsula of Michigan, where public access is scarce and the majority of hunters reside. Understanding the economic values hunters derive from publicly accessible hunting lands will enable managers and policy makers to make better decisions when considering policy options that involve reducing or increasing public access. © 2011 The Wildlife Society.
A comparative study of adverse drug reactions during two heat waves that occurred in France in 2003 and 2006
Authors: Sommet Agnès , Durrieu Genevieve , Lapeyre‐Mestre Maryse , Montastruc Jean‐Louis ,   The Association of French PharmacoVigilance Centres
Published: December 2011

ABSTRACTPurposeHeat waves could reveal or aggravate several ‘serious’ adverse drug reactions (ADRs) in elderly. Thus, we wanted to describe the main characteristics of heat‐related ‘serious’ ADRs occurred in patients older than 70 years during these two events in France (2003 and 2006).MethodsWe analysed ‘serious’ ADRs reported to the network of French pharmacovigilance centres in summer 2003 and 2006 and suspected to be heat related. ‘Serious’ ADRs occurred during summers with heat waves (2003 and 2006) were compared with ADRs occurred during the same months in the summers of 2004 and 2005 (reference period).ResultsPatients' characteristics and number of ‘serious’ ADRs were similar whatever the year of the study. Number of drug‐related deaths seemed higher in 2003 than in 2004–2005. More ‘serious’ heat‐related ADRs were reported in the summers of 2003 and 2006 (68 in 2003 and 72 in 2006). Comparing with the reference period, metabolic ADRs were less frequent during the summers of 2003 (29%, p = 0.0001) and 2006 (39%, p = 0.003). Occurrence of other ADRs was similar whatever the period. Drugs more frequently involved during heat waves were diuretics, serotonic antidepressants, angiotensin converting inhibitors and proton pump inhibitors. Differences between 2003 and 2006 were found for non‐dopaminergic (atropinic) antiparkinsonians or antiepileptics (most frequently involved in 2006) and beta‐blockers or proton pump inhibitors (less frequently involved in 2006).ConclusionThe present study underlines the interest of a National Pharmacovigilance Database to follow each year the role of drugs in heat‐related ADRs. This survey should be associated with other pharmacoepidemiological methods, such as case–control or population‐based studies. Copyright © 2011 John Wiley & Sons, Ltd.
Friday Letters : Connecting Students, Teachers, and Families Through Writing
Authors: Newman Terry H. , Bizzarri Sarah A. 
Published: December 2011

AbstractAn important part of student success in school is the involvement of families. However, the communication between students and families regarding school is often sparse at best and caregivers can feel left out as to what is happening. Friday letters improve communication between students and families and also provide a myriad of instructional opportunities. Students are taken through the optimal learning model of explicit writing instruction, shared writing experiences, and independent writing. Students write a letter to their parents each Friday detailing their behavioral and academic accomplishments. Feedback is provided to students based on individualized needs. Students are excited about this writing because it is meaningful to them and written to an authentic audience. Families are excited because they receive weekly updates regarding their child's academic and social endeavors. Teachers are excited because their students are advancing their writing skills while improving communication between students, families, and teachers.
Plasmachemisches Ätzen und Beschichten bei Atmosphärendruck
Authors: Lopez Elena , Linaschke Dorit , Dresler Birte , Dani Ines , Leyens Christoph , Beyer Eckhard 
Published: December 2011

AbstractZur industriellen Herstellung waferbasierter kristalliner Silizium‐Solarzellen kommt eine Vielzahl unterschiedlichster Technologien zum Einsatz. Die Kombination dieser Technologien erfordert ein aufwändiges Handling der Wafer, was nicht nur die Investitionskosten, sondern auch die Gefahr des Waferbruchs erhöht.Der Einsatz von Plasmatechnologien bietet die Möglichkeit, alle Prozessschritte in der Herstellungskette kristalliner Siliziumsolarzellen ohne Nutzung nasschemischer Bäder oder Vakuumprozesse durchzuführen. Am Fraunhofer IWS wurden alle zur Solarzellenfertigung erforderlichen Ätzprozesse sowie die Abscheidung der Passivierungs‐ und Antireflexschicht mit Hilfe von Atmosphärendruck‐Plasmaprozessen erfolgreich demonstriert.