bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of 6‐Substituted 2(1H)‐Pyridon‐3‐yl C‐2′‐Deoxyribonucleosides
Authors: Chapuis Hubert , Kubelka Tomáš , Joubert Nicolas , Pohl Radek , Hocek Michal 
Published: February 2012

AbstractTwo approaches to the synthesis of the title 6‐substituted 2(1H)‐pyridon‐3‐yl C‐2′‐deoxyribonucleosides have been pursued. A protected 6‐aminopyridine C‐nucleoside intermediate was converted into the N‐oxide followed by Ac2O‐mediated rearrangement and final deprotection to give 6‐acetylamino‐2‐oxo(1H)‐pyridin‐3‐yl deoxyribonucleoside. Due to the unusually high stability of the N‐acetyl group, the full deprotection was unsuccessful. In the second approach, 6‐chloro‐2‐pyridone was converted into phosphorodiamidate, which underwent ortho‐magnesiation and iodination to give the 3‐iododerivative. It was then used in a Heck coupling with a sugar glycal and the resulting product deprotected to give 6‐chloro‐2‐oxo(1H)‐pyridin‐3‐yl deoxyribonucleoside, which was either directly or after reprotection converted into 6‐methyl‐, 6‐amino‐, and 6‐unsubstituted pyridone C‐nucleosides. The final nucleosides were very unstable and easily epimerized and/or oxidized, which limits (but not excludes) their further use in chemical biology.
Cicindeloine from Stenus cicindeloides – Isolation, Structure Elucidation, and Total Synthesis
Authors: Müller Tobias , Göhl Matthias , Lusebrink Inka , Dettner Konrad , Seifert Karlheinz 
Published: February 2012

AbstractThe new piperideine alkaloid cicindeloine (3) was isolated from the pygidial glands of the beetles Stenus cicindeloides and Stenus solutus. The structure and absolute configuration of 3 were elucidated by NMR spectroscopy and asymmetric synthesis, respectively. A very efficient gram‐scale synthesis of 3 was developed using an intramolecular aza‐Wittig reaction as the final step. The synthetic route is comprised of 12 steps and proceeds in 20 % total yield. Nine of the 12 steps were conducted without column chromatography.
Solvent‐Free Tandem Synthesis of 2‐Thiazolines and 2‐Oxazolines Catalyzed by a Copper Catalyst
Authors: Li Xiangnan , Zhou Baoyue , Zhang Jin , She Mengyao , An Shujuan , Ge Haixia , Li Cong , Yin Bing , Li Jianli , Shi Zhen 
Published: February 2012

AbstractTandem reactions of nitriles with 2‐aminoethanethiol hydrochloride or amino alcohols in the presence of a catalytic amount of cupric methacrylate (CuII2L4, L = methacrylate) were employed to prepare 2‐thiazolines and 2‐oxazolines under mild reaction conditions. The synthetic procedure showed high selectivity for the synthesis of mono‐ and bis‐thiazolines and oxazolines, and a variety of 2‐thiazolines and 2‐oxazolines was obtained in good to excellent yields.
Size Dependant Electrochemical Behavior of Silver Nanoparticles with Sizes of 10, 20, 40, 80 and 107 nm
Authors: Giovanni Marcella , Pumera Martin 
Published: February 2012

AbstractThe direct detection of metal nanoparticles is of high importance. Here we investigate inherent electrochemistry of silver nanoparticles of sizes 10, 40, 80 and 107 nm by means of cyclic voltammetry.
Nonlinear behavior of high‐damping rubber bearings under horizontal bidirectional loading: full‐scale tests and analytical modeling
Authors: Yamamoto Masashi , Minewaki Shigeo , Yoneda Harumi , Higashino Masahiko 
Published: February 2012

SUMMARYHorizontal bidirectional loading tests are conducted for real‐sized high‐damping rubber (HDR) bearings with diameters of 700 mm (HDR700) and 1300 mm (HDR1300). The hysteresis loops of these bearings under bidirectional horizontal loadings are compared with those under unidirectional loadings. The results show that the bearing force measurement in the primary direction of loading increases when there is displacement in the orthogonal direction. Unusually, the maximum restoring force in the orthogonal direction to the primary loading direction occurs near zero displacement. On the basis of the observations of the restoring forces, a rate‐independent model is proposed. This model simulates well the test results under both bidirectional loading and unidirectional loading. It can reproduce the irregular restoring forces characteristics around zero displacement as described above. Bidirectional loading induced twist deformation in the HDR bearings that increased local shear strains. This phenomenon results in an early failure as observed in HDR700. The additional shear strain is estimated based on the twist deformation measured by video image analysis. The comparison of the nominal total shear stress demonstrates that the increase of shear stress because of bidirectional loading occurs when the average shear strain is larger than about 200%. The larger the shear strain, the greater the bidirectional effect. It is shown that the nominal total shear stress of average strain of 350% under bidirectional circular loading pattern is approximately the same as the average shear strain of 400% under unidirectional loading. This means that the average shear strain of 350% under a bidirectional circular loading corresponds to a local shear strain of 400%. Copyright © 2012 John Wiley & Sons, Ltd.
Contribution of germline mutations to PARK2 gene inactivation in lung adenocarcinoma
Authors: Iwakawa Reika , Okayama Hirokazu , Kohno Takashi , Sato‐Otsubo Aiko , Ogawa Seishi , Yokota Jun 
Published: February 2012

AbstractHomozygous germline mutations of the PARK2 gene are responsible for the development of early‐onset Parkinson's disease (PD). Homozygous PARK2 mutations have been also detected in lung adenocarcinoma (LADC). However, since heterozygous PARK2 germline mutations are present in a subset of non‐PD individuals, the timing for the occurrence of two‐hit PARK2 mutations in LADC progression is unclear. Therefore, we comprehensively analyzed mutations, expression and copy number variations of the PARK2 gene in 267 primary LADCs together with the corresponding noncancerous lung cells and 39 LADC cell lines. Heterozygous germline exonic deletions were detected in five patients with LADC, and loss of heterozygosity including the PARK2 locus was detected in 31/267 (11.6%) LADCs. However, homozygous PARK2 inactivation was not detected in any of them, including the five patients with germline mutations. Homozygous PARK2 inactivation was detected in 6/39 (15%) cell lines, two exonic deletions, one exonic duplication, and three point mutations, while heterozygous PARK2 inactivation was detected in two cell lines (both by exonic deletions). These results strongly indicate that somatic PARK2 mutations occur rarely (or do not occur) in LADC development and that germline PARK2 mutations could contribute to LADC progression but not to LADC development. © 2012 Wiley Periodicals, Inc.
Development of adsorbents for CO2 capture from waste materials: a review
Authors: Olivares‐Marín Mara , Maroto‐Valer M. Mercedes 
Published: February 2012

AbstractIn recent years, a number of scientific papers have been published on the use of residues from industrial and agricultural operations to develop adsorbents for CO2 capture at low, medium, and high temperatures. This is mainly because these waste materials are low‐cost and abundant, and may contribute to a reduction of the total costs in carbon capture technologies. In addition, environmental concerns may also be addressed by developing strategies that can use these waste materials instead of burning or sending them to landfills. This review analyses the recent progress made in the development of CO2 adsorbents made from waste precursors. The different preparation approaches developed for the synthesis of adsorbents, including type of raw waste‐material, experimental methods, and further modifications, are reviewed. © 2012 Society of Chemical Industry and John Wiley & Sons, Ltd
Effects of vitamin E on bone turnover markers among US postmenopausal women
Authors: Hamidi Maryam S , Corey Paul N , Cheung Angela M 
Published: February 2012

Abstract
Increased oxidative stress and inflammation resulting from aging and declining estrogen levels can lead to increased bone loss in postmenopausal women. Alpha-tocopherol and gamma-tocopherol, the two predominant isomers of vitamin E, have antioxidant and anti-inflammatory properties, but their effects on bone metabolism have not been well studied in humans. We examined the associations between dietary and total (diet and supplements) alpha-tocopherol intake, serum alpha-tocopherol and gamma-tocopherol levels and their ratio, and bone turnover markers (BTMs) among postmenopausal women aged ≥45 years. We used cross-sectional data from the National Health and Nutrition Examination Survey 1999–2002. Multiple regression models with adjustments for relevant confounders were used to examine the associations between intake and serum levels of tocopherols, and serum bone-specific alkaline phosphatase (BAP), a biomarker of bone formation, and urinary N-telopeptides/creatinine (uNTx/Cr), a biomarker of bone resorption. The study sample included 497 postmenopausal women who were not taking estrogen, steroids, or osteoporosis medications, were free from kidney and liver disease, cancer, and rheumatoid arthritis, and were fasting &gt;9 hours prior to examination. Participants had a mean age of 65.5 ± 0.6 years and over 45% used vitamin E (alpha-tocopherol) supplements in the past month. Vitamin E supplement users had significantly lower serum gamma-tocopherol, higher serum alpha-tocopherol levels, and higher ratio of serum alpha-tocopherol to gamma-tocopherol than nonusers. High serum gamma-tocopherol levels and low ratio of serum alpha-tocopherol to gamma-tocopherol were associated with increased BAP levels (p &lt; 0.01 for both). There were no associations between any of the vitamin E variables and uNTx/Cr. In conclusion, we hypothesize that gamma-tocopherol may uncouple bone turnover, resulting in more bone formation than resorption. Vitamin E supplements in the form of alpha-tocopherol suppress serum gamma-tocopherol levels and may have negative effects on bone formation. Further research is needed to investigate the potential anabolic effect of gamma-tocopherol from food sources on bone. © 2012 American Society for Bone and Mineral Research.
Demonstration of osteocytic perilacunar/canalicular remodeling in mice during lactation
Authors: Qing Hai , Ardeshirpour Laleh , Divieti Pajevic Paola , Dusevich Vladimir , Jähn Katharina , Kato Shigeaki , Wysolmerski John , Bonewald Lynda F 
Published: February 2012

Abstract
Osteoclasts are thought to be solely responsible for the removal of bone matrix. However, we show here that osteocytes can also remove bone matrix by reversibly remodeling their perilacunar/canalicular matrix during the reproductive cycle. In contrast, no osteocytic remodeling was observed with experimental unloading despite similar degrees of bone loss. Gene array analysis of osteocytes from lactating animals revealed an elevation of genes known to be utilized by osteoclasts to remove bone, including tartrate-resistant acid phosphatase (TRAP) and cathepsin K, that returned to virgin levels upon weaning. Infusion of parathyroid hormone–related peptide (PTHrP), known to be elevated during lactation, induced TRAP activity and cathepsin K expression in osteocytes concurrent with osteocytic remodeling. Conversely, animals lacking the parathyroid hormone type 1 receptor (PTHR1) in osteocytes failed to express TRAP or cathepsin K or to remodel their osteocyte perilacunar matrix during lactation. These studies show that osteocytes remove mineralized matrix through molecular mechanisms similar to those utilized by osteoclasts. © 2012 American Society for Bone and Mineral Research.
Synthesis of 3‐(3,5‐dinitropyrazol‐4‐yl)‐4‐nitrofurazan and its salts
Authors: Sheremetev Aleksei B. , Yudin Igor L. , Palysaeva Nadezhda V. , Yu. Suponitsky Kyrill 
Published: February 2012

AbstractThe annulation reaction of vinamidinium salt containing nitrofurazanyl moiety at the β‐position gives access to the corresponding pyrazole. At nitration, two nitro groups were installed to the pyrazole ring. The synthesized 3‐(3,5‐dinitropyrazol‐4‐yl)‐4‐nitrofurazan13is strong NH acid and a new family energetic salts was prepared by direct neutralization with high nitrogen bases. Compound13crystallizes in the monoclinic space groupP21/c, and charaterized by high density of 1.979 g/cm3(at 100 K). J. Heterocyclic Chem., (2012).
Is apparent diffusion coefficient reliable and accurate for monitoring effects of antiangiogenic treatment in a longitudinal study?
Authors: Suh Ji‐Yeon , Cho Gyunggoo , Song Youngkyu , Lee Chang Kyung , Kang Jong Soon , Kang Moo Rim , Park Sung Bin , Kim Young Ro , Kim Jeong Kon 
Published: February 2012

AbstractPurpose:To evaluate the reliability and accuracy of the apparent diffusion coefficient (ADC) for monitoring antiangiogenic treatment in a longitudinal study.Materials and Methods:Tumor volume and ADC were monitored by T2‐weighted magnetic resonance imaging (MRI) and diffusion‐weighted MRI, respectively, in 18 mice with angiogenesis‐dependent tumors (U118MG) before (day 0) and after 2, 7, 14, and 21 days of administration of the antiangiogenic agent sunitinib maleate (n = 12) or vehicle (n = 6). Percent changes in tumor volume and ADC were calculated and correlations between tumor volume and ADC were evaluated.Results:Tumor volume and ADC showed a negative correlation at 69 of the 72 (96%) follow‐up measurements. In the 13 mice with tumor regrowth, ADC started to decrease before (27%) or at the same time (73%) as tumor regrowth. Pretreatment ADC and percent change in ADC change on days 0–2 were similar in mice with positive and negative responses to treatment (0.851 vs. 0.999, 24% vs. 16%). Percent change of ADC showed significant negative correlation with percent change in tumor volume in both the control (r = −0.69) and treated (r = −0.65) groups.Conclusion:Percent change in ADC is a reliable and accurate marker for monitoring the effects of antiangiogenic treatment, whereas pretreatment ADC and early changes in ADC (ie, days 0–2) are limited in predicting treatment outcome. J. Magn. Reson. Imaging 2012;35:1430–1436. © 2012 Wiley Periodicals, Inc.
Increased [3H]D‐aspartate release and changes in glutamate receptor expression in the hippocampus of the mnd mouse
Authors: Bigini Paolo , Milanese Marco , Gardoni Fabrizio , Longhi Annalisa , Bonifacino Tiziana , Barbera Sara , Fumagalli Elena , Di Luca Monica , Mennini Tiziana , Bonanno Giambattista 
Published: February 2012

AbstractNeuronal ceroid lipofuscinoses (NCLs) are a group of hereditary childhood diseases characterized mainly by lipopigment accumulation and a multisystemic pattern of symptoms including mental retardation, seizures, motor impairment, and blindness. The mnd mouse, carrying a mutation in the Cln8 gene, has been proposed as a model of epilepsy with mental retardation (EPMR, ornorthern epilepsy). We recently showed neuronal hyperexcitability and seizure hypersusceptibility in mnd mice. To elucidate the cellular mechanisms related to hippocampal hyperexcitability, the glutamatergic transmission and the expression of postsynaptic glutamate receptors were investigated in hippocampus. A significant increase in either spontaneous or KCl‐stimulated overflow of [3H]D‐aspartate was found in mnd mice compared with controls. This increase was maintained after DL‐threo‐β‐benzyloxyaspartic acid (TBOA) treatment, suggesting a nonrelevant role for transporter‐mediated release and supporting the involvement of exocytotic [3H]D‐aspartate release. Accordingly, Ca2+‐dependent overflow induced by ionomycin was also increased in mnd mice. Levels of glutamate 1–3 AMPA receptor subunits were increased, and levels of the NR2A NMDA receptor subunit were decreased in the hippocampus of mnd mice, suggesting an adaptive response to glutamate overstimulation. © 2012 Wiley Periodicals, Inc.
Effect of long‐term betaine supplementation on chemical and physical characteristics of three muscles from the Alentejano pig
Authors: Martins José M , Neves José A , Freitas Amadeu , Tirapicos José L 
Published: February 2012

AbstractBACKGROUND: The use of betaine as a dietary supplement to reduce fat deposition and increase lean muscle mass in pigs is increasing. However, there is no available information on its effect on the physical and chemical (i.e. fatty acid (FA) profile) characteristics of pork.RESULTS: The effects of long‐term betaine intake (1 g betaine kg−1 diet for 20 weeks) on the chemical and physical characteristics of Musculus longissimus dorsi, M. biceps femoris and M. semimembranosus from the Alentejano pig were investigated. The contents of total protein, intramuscular lipids (neutral and polar), myoglobin and total collagen as well as the water‐holding capacity, physical colour characteristics and FA profile of the three muscles were determined. With the exception of a significant increase in the intramuscular lipid content of M. longissimus dorsi and M. biceps femoris, betaine supplementation did not influence muscle chemical and colour characteristics or body fat deposition.CONCLUSION: These data suggest that long‐term betaine supplementation selectively increases intramuscular lipid deposition (a trait related to meat quality) while not affecting other chemical (including the atheroprotective FA profile) and physical characteristics of the Alentejano pig muscles studied. Copyright © 2012 Society of Chemical Industry
Growth and mineral acquisition response of grapevine rootstocks (Vitis spp.) to inoculation with different strains of plant growth‐promoting rhizobacteria (PGPR)
Authors: Sabir Ali , Yazici M Atilla , Kara Zeki , Sahin Fikrettin 
Published: February 2012

AbstractBACKGROUND: Effects of the plant growth‐promoting rhizobacteria (PGPR) strains Burkholderia gladii BA‐7, Bacillus subtilis OSU‐142, Bacillus megatorium M‐3 and Azospirillum brasilense Sp 245 on vegetative development and mineral uptake of 1103 P and 41 B grapevine rootstocks were investigated. The roots of nursery plants of the grapevine rootstocks were immersed in bacterial solutions and transplanted to a sterilised peat and perlite mixture in 5 L pots. Plants were cultivated in a semi‐controlled glasshouse during the vegetation period.RESULTS: Vegetative development of grapevine rootstocks was obviously promoted by bacterial inoculation, with the maximum increase induced by Sp 245. Inoculation with Sp 245 also significantly improved the chlorophyll concentrations of the leaves of the two rootstocks. Among the bacteria, OSU‐142 also significantly stimulated vegetative development and mineral acquisition of the plants. Nutrient contents of the leaf blades of the plants were generally higher than those of control plants.CONCLUSION: Overall investigations revealed that A. brasilense Sp 245 and B. subtilis OSU‐142 performed more efficiently than the other strains. Therefore these bacteria seem to have considerable potential in reducing the need for inorganic fertiliser. Copyright © 2012 Society of Chemical Industry
Factors influencing survival in patients undergoing palliative bypass for pancreatic adenocarcinoma
Authors: Gray Phillip J. , Wang Jingya , Pawlik Timothy M. , Edil Barish H. , Schulick Richard , Hruban Ralph H. , Dao Harry , Cameron John , Wolfgang Christopher , Herman Joseph M. 
Published: February 2012

AbstractPurposeThe purpose of this study is to identify factors predictive of early mortality following palliative bypass in patients with previously unsuspected advanced pancreatic adenocarcinoma to provide a basis for the selection of appropriate therapies.MethodsAll patients with pancreatic adenocarcinoma who underwent a bypass procedure at our institution between 9/30/1994 and 1/31/2006 were reviewed. Patients with peri‐operative mortality were excluded from the analysis. Univariate analysis was performed on peri‐operative data to identify factors associated with early mortality (death within 6 months of surgery). Patients having multiple risk factors were assigned an overall prognostic score based on the sum of these factors.ResultsOf the 397 patients with pancreatic adenocarcinoma analyzed, four factors were found to predict early mortality following palliative bypass: Presence of distant metastatic disease (HR 2.59, P < 0.0001), poor tumor differentiation (HR 1.71, P = 0.009), severe pre‐operative nausea and vomiting (HR 1.48, P = 0.013), and lack of previous placement of a biliary stent (HR 1.36, P = 0.048). Patients with a prognostic score of 0 were significantly more likely to survive past 6 months than patients with a prognostic score of 1 (HR 2.71, P < 0.0001), 2 (HR 3.70, P < 0.0001), or ≥3 (HR 5.63, P < 0.0001).ConclusionsIn a cohort of patients undergoing a palliative bypass procedure, specific peri‐operative factors can be used to identify patients who are at risk of early mortality. These factors may be helpful in selecting appropriate interventions for this group of patients. J. Surg. Oncol. 2012; 106:66–71. © 2012 Wiley Periodicals, Inc.
From anti‐Stokes photoluminescence to resonant Raman scattering in GaN single crystals and GaN‐based heterostructures
Authors: Ding Y.J. , Khurgin J.B. 
Published: February 2012

AbstractThe progress on anti‐Stokes photoluminescence and Stokes and anti‐Stokes Raman scattering in GaN single crystals and GaN/AlN heterostructures is reviewed. Anti‐Stokes photoluminescence investigated in the past was primarily attributed to two‐photon absorption, three‐photon absorption, and phonon‐assisted absorption. On the other hand, anti‐Stokes Raman scattering was used to determine electron‐phonon scattering time and decay time constant for longitudinal‐optical phonons. In a typical high electron mobility transistor based on GaN/AlN heterostructures, strong resonances were reached for first‐order and second‐order Raman scattering processes. Therefore, both Stokes and anti‐Stokes Raman intensities were dramatically enhanced. The feasibility of laser cooling of a nitride structure has been demonstrated. Anti‐Stokes photoluminescence and Raman scattering have potential applications in upconversion lasers and laser cooling of nitride ultrafast electronic and optoelectronic devices.
Preparation of Responsive Micrometer‐Sized Microgel Particles with a Highly Functionalized Shell
Authors: Li Zifu , Kwok Man‐Hin , Ngai To 
Published: February 2012

AbstractWe describe a facile approach for the synthesis of micrometer‐sized (∼3.5 μm), pH‐responsive microgel particles, which have functional carboxylic acid groups concentrated in the shell. The large size offers the possibility to directly study the interactions between individual, isolated microgel particles with active ingredients by optical microscopy. Our results show that the synthesized microgel particles can load and release active ingredients via changing pH values. The complexation of Ca2+ with the ‐COOH functional groups located at the microgel surfaces not only regulates the active ingredient's uptake efficiency, but also provides a novel way to reveal the spatial distribution of the functional groups inside the microgel particles.