bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Straightforward Approach towards Isoxazoline Amino Acid Esters by Domino Michael Additions/Nitrile Oxide Cycloadditions
Authors: Wirtz Lisa , Kazmaier Uli 
Published: May 2011

AbstractThe syntheses of new heterocyclic isoxazoline amino acids are described based on a domino Michael addition/nitrile oxide formation/[3+2] cycloaddition approach. Chelated amino acid ester enolates can be added to nitroalkenes, and the generated nitronates are directly converted into nitrile oxides. These can be trapped intramolecularly by an alkene as a dipolarophile. The alkene can be introduced either via the nitroalkene or via the chelated enolate. Therefore, different types of heterocyclic amino acids can be obtained in a simple one‐pot protocol.
Gastrostomy tube placement and use in patients with head and neck cancer
Authors: Locher Julie L. , Bonner James A. , Carroll William R. , Caudell Jimmy J. , Kilgore Meredith L. , Ritchie Christine S. , Roth David L. , Tajeu Gabriel S. , Yuan Ya , Allison Jeroan J. 
Published: May 2011

AbstractBackgroundEnteral nutritional support is used in care for patients with head and neck cancer. This study describes the frequency and timing of gastrostomy tube placement and corresponding Medicare nutritional support claims in patients with head and neck cancer.MethodsSurveillance, Epidemiology, and End Results (SEER)–Medicare data for patients with head and neck cancer diagnosed from 2000 to 2005 were used in this descriptive study (N = 16,458).ResultsIn all, 35.1% of patients undergoing treatment had gastrostomy tubes placed; 16.9% had tubes placed before treatment, whereas 83.1% had them placed after treatment. Of those having tubes placed prior to treatment 23.7% had Medicare claims for nutritional support before treatment and 40.9% had claims after treatment began. A total of 35.4% of patients who had tubes placed before treatment and 35.5% who had tubes placed after treatment had no claims for nutritional support.ConclusionsFuture work is warranted to identify predictors and outcomes associated with provision and timing of enteral nutrition support for patients with head and neck cancer. © 2011 Wiley Periodicals, Inc. Head Neck, 2012
Atractyloside induces low contractile reaction of arteriolar smooth muscle through mitochondrial damage
Authors: Song Rui , Bian Huining , Huang Xuliang , Zhao Ke‐seng 
Published: May 2011

ABSTRACTAtractyloside is the principal naturally occurring active ingredient in ethnomedicines and animal grazing forage. Evidence that atractyloside can induce opening of the mitochondrial permeability transition pore (mPTP) indicates that mitochondrial mechanisms may play an important role in pathophysiological lesions of the heart, liver and kidney after atractyloside poisoning. Therefore, in this study we investigated the association of atractyloside‐induced mitochondrial damage in arteriolar smooth muscle cells (ASMCs) with contractile reaction. Atractyloside led to depolarized and swollen or damaged ASMC mitochondria, which might be related to the concentration‐dependent induction of mPTP opening. Relative ATP content in ASMCs was significantly reduced by 48%, 63% and 66% of control when cells were treated with 7.5, 10, and 15 µm atractyloside for 10 min, respectively, and ASMCs were hyperpolarized. In addition, the contractile responsiveness of ASMCs was eventually weakened. These results suggest that atractyloside has a toxic effect on vasoreactivity, which is possibly related to mitochondrial damage. Copyright © 2011 John Wiley & Sons, Ltd.
Ultrastructural effects of cisplatin on the inner ear and lateral line system of zebrafish (Danio rerio) larvae
Authors: Giari Luisa , Dezfuli Bahram Sayyaf , Astolfi Laura , Martini Alessandro 
Published: May 2011

ABSTRACTZebrafish, Danio rerio, has been a prominent model vertebrate for the study of chemical toxicity and human disease. Zebrafish hair cells (HCs) show significant structural, functional and molecular similarities to the mammalian inner ear HCs. We examined the effects of cisplatin, an anti‐cancer drug, on HCs of the inner ear and on HCs and support cells (SCs) of neuromasts in zebrafish using transmission and scanning electron microscopy. Forty‐five zebrafish larvae, 12 days post‐fertilization, were assessed: 15 unexposed controls, 15 exposed to 10 µm cisplatin solution, and 15 exposed to 50 µm cisplatin solution. Hair cells in the cristae and maculae of the inner ear and of neuromasts were extremely sensitive to cisplatin. The drug was associated with vacuolization and the presence of myelinoid bodies in HC cytoplasm and with a condensation of the nuclear chromatin. The predominant pattern of injury was widespread degeneration of mitochondria, which appeared swollen and less electron‐dense with disorganized or reduced cristae. Severity of damage seemed to be concentration‐dependent, and the inner ear suffered more damage than the lateral line. Alterations similar to those in HCs were also observed in SCs of the neuromasts. Scanning electron microscopy showed loss of kinocilia in neuromasts of fish exposed to the higher concentration of cisplatin. Copyright © 2011 John Wiley & Sons, Ltd.
Decreased oxygen tension lowers reactive oxygen species and apoptosis and inhibits osteoblast matrix mineralization through changes in early osteoblast differentiation
Authors: Nicolaije Claudia , Koedam Marijke , van Leeuwen Johannes P.T.M. 
Published: May 2011

AbstractAccumulating data show that oxygen tension can have an important effect on cell function and fate. We used the human pre‐osteoblastic cell line SV‐HFO, which forms a mineralizing extracellular matrix, to study the effect of low oxygen tension (2%) on osteoblast differentiation and mineralization. Mineralization was significantly reduced by 60–70% under 2% oxygen, which was paralleled by lower intracellular levels of reactive oxygen species (ROS) and apoptosis. Following this reduction in ROS the cells switched to a lower level of protection by down‐regulating their antioxidant enzyme expression. The downside of this is that it left the cells more vulnerable to a subsequent oxidative challenge. Total collagen content was reduced in the 2% oxygen cultures and expression of matrix genes and matrix‐metabolizing enzymes was significantly affected. Alkaline phosphatase activity and RNA expression as well as RUNX2 expression were significantly reduced under 2% oxygen. Time phase studies showed that high oxygen in the first phase of osteoblast differentiation and prior to mineralization is crucial for optimal differentiation and mineralization. Switching to 2% or 20% oxygen only during mineralization phase did not change the eventual level of mineralization. In conclusion, this study shows the significance of oxygen tension for proper osteoblast differentiation, extra cellular matrix (ECM) formation, and eventual mineralization. We demonstrated that the major impact of oxygen tension is in the early phase of osteoblast differentiation. Low oxygen in this phase leaves the cells in a premature differentiation state that cannot provide the correct signals for matrix maturation and mineralization. J. Cell. Physiol. 227: 1309–1318, 2012. © 2011 Wiley Periodicals, Inc.
Occurrence, biochemical profile of vascular endothelial growth factor (VEGF) isoforms and their functions in endochondral ossification
Authors: Patil A.S. , Sable R.B. , Kothari R.M. 
Published: May 2011

AbstractVascular endothelial growth factor (VEGF), initially detected in bovine pituitary follicular cells, is widely localized in hypertrophic zones of chondrocytes in various tissues where focus is on bone growth. Similarly, VEGF found in chondrocytes of articular cartilage of osteo‐arthritic/rheumato‐arthritic joints reflected need for bone repair. Members of VEGF family of human origin are seven homo‐dimeric, heparin‐binding glyco‐proteins, encoded by different genes located on different chromosomes. They encode seven isoforms: VEGF‐A, ‐B, ‐C, ‐D, ‐E, ‐F, and PLGF, each catalyzing distinct functions. They are compared with VEGFs derived from bovine origin in biochemical composition and functions. Each isoform and subtype has specific receptors for binding, necessary for expression of specific functions in bone growth or repair. VEGF control is by diffusion of isoforms, hypoxic conditions, and bone (mandibular) positioning. Thus, transformation of cartilage into bone involves proliferation of mesenchymal cells, hypertrophy in chondrocytes, capillary invasion, and calcification by extra cellular matrix (ECM). Inherent limitations of in vitro/in vivo models and chronology of appearance of different isoforms have eluded precise mechanism of VEGF action and regulation. Nonetheless, central role of VEGF in bone growth is quite obvious. J. Cell. Physiol. 227: 1298–1308, 2012. © 2011 Wiley Periodicals, Inc.
Changes in microbial‐community structure with depth and time in a chronosequence of restored grassland soils on the Loess Plateau in northwest China
Authors: Huang Yi‐mei , Michel Kerstin , An Shao‐shan , Zechmeister‐Boltenstern Sophie 
Published: May 2011

AbstractMicrobial‐community structure is closely associated with plant‐community composition. The objective of this study was to evaluate the effects of depth and revegetation time on the microbial‐community structure of restored grassland soils of the Loess Plateau of China. Microbial‐community structure at 0–10 cm (depth 1) and 10–20 cm (depth 2) of eight sites of a grassland chronosequence with revegetation time ranging from 1 to 78 y was determined using phospholipid fatty acid (PLFA) analysis. Except for the youngest site microbial‐community structure at the two depths varied distinctly with actinomycetes and vesicular arbuscular mycorrhiza as the most important discriminators. Total PLFA content decreased with depth and increased with revegetation time. Protozoa were the only functional group whose proportion did not change with depth. Their relative abundance tended to decrease with increasing revegetation time. The microbial community at all sites was bacteria‐dominated with Gram‐negative bacteria representing the largest proportion. Principal‐component and cluster analysis revealed that microbial‐community structure in the surface soil (depth 1) of the older sites (23–78 y of revegetation) was rather similar which may be due to only small effects of the plant species present on the soil environment. Differences in microbial‐community composition at 0–20 cm depth of the eight sites were partly related to variations in the physico‐chemical characteristics. Relations to organic C, alkali‐extractable N, pH, and available P were found. Revegetation of former agricultural sites on the Loess Plateau improves the soil status and leads to shifts in microbial‐community structure more pronounced with depth than time.
Surface‐enhanced Raman spectroscopy of 4‐tert‐butylpyridine on a silver electrode
Authors: Livingstone Richard , Lombardi John R. 
Published: May 2011

AbstractWe report the observation of large surface‐enhanced Raman scattering (SERS) (106) for 4‐tert‐butylpyridine molecules adsorbed on a silver electrode surface in an electrochemical cell with electrode potential set at − 0.5 V. A decrease in electrode potential to − 0.3 V was accompanied by a decrease in relative intensities of the vibrational modes. However, there were no changes in vibrational wavenumbers. Comparison of both normal solution Raman and SERS spectra shows very large enhancement of the intensities of a1, a2, and b2 modes at laser excitation of 488 nm. Enhancement of the non‐totally symmetric modes indicates the presence of charge transfer as a contributor to the enhancement. Copyright © 2011 John Wiley & Sons, Ltd.
DROUGHT MORTALITY OF TREE SEEDLINGS IN AN ERODED TROPICAL PASTURE
Authors: Martínez‐Garza C. , Tobon W. , Campo J. , Howe H. F. 
Published: May 2011

ABSTRACTExperimental restoration may both accelerate and elucidate natural processes of succession on degraded agricultural land by offering insight into factors that influence rates of succession and the composition of resulting communities. A novel study in restoration of degraded tropical agricultural land in coexistence with cattle ranching activities was established in southern Veracruz, Mexico. The experimental planting of 16 mixed‐species stands of 18 pioneer and late‐successional tree species was established from September to November 2006 on an eroded hillside pasture with an elevational gradient from 182 to 260 m and heterogeneous soil depths. An unusually severe dry season in 2007 killed 72 per cent of the seedlings: least squares regression suggested that survival of six pioneer and 12 late‐successional species was mainly explained by initial basal diameter at planting followed by soil depth for pioneers and by elevational position on the hillside for late‐successional species. Individuals with larger initial size at planting (>4 mm basal diameter), regardless of germination size in a growing house, survived better probably because larger seedlings developed deeper roots that found fissures in substrate underlying thin soils. Interestingly, seedlings small at planting (<4 mm basal diameter) survived as well as large seedlings in deeper (>19 cm) soils, but virtually, all small seedlings died on thin soils (<18·5 cm). Mortality in restoration plantings can be reduced by planting large seedlings of a mix of pioneer and late‐successional species, recognizing that soil depth is a key criterion for survival of the smallest seedlings in a cohort. Copyright © 2011 John Wiley & Sons, Ltd.
Dependence of Dielectric Properties and Percolative Behavior on Phase Separation Structure Induced by Heterogeneous Carbon Nanofiber Distribution in Polymer Blend Nanocomposites
Authors: Sun Li‐Li , Zhao Yan , Zhong Wei‐Hong 
Published: May 2011

AbstractMany thermoplastics currently used in industry are in fact polymer blends and there is a pressing need to understand the dependence of the dielectric properties and percolative behaviors of the multi‐phase polymers with heterogeneous nanofiller distributions. When nanofillers distribution occurs in a polymer blend with phase separation, the dielectric properties and percolative behaviors have been shown to be more complex, and very sensitive to the distribution of the nanofillers. As a basis, the dielectric properties and alternating current (AC) conductivities of the binary carbon nanofiber (CNF)/high density polyethylene (HDPE) composite system were first characterized. Subsequently the properties of the ternary CNF/ultra‐high molecular weight polyethylene (UHMWPE)/HDPE composites were compared and analyzed. Combined with the evidence showing the phase separation of UHMWPE and HDPE and the CNFs exclusively dispersed in HDPE phase, it was inferred that UHMWPE acting as a non‐conductive additive, dramatically changed the uniform CNF presence in the matrix into a heterogeneous distribution. As a result, the dependencies of dielectric properties and conductivities on frequency were strongly affected, and in particular the percolative characteristics showed significantly increased dependencies. magnified image
Parallel reconstruction using null operations
Authors: Zhang Jian , Liu Chunlei , Moseley Michael E. 
Published: May 2011

AbstractA novel iterative k‐space data‐driven technique, namely parallel reconstruction using null operations (PRUNO), is presented for parallel imaging reconstruction. In PRUNO, both data calibration and image reconstruction are formulated into linear algebra problems based on a generalized system model. An optimal data calibration strategy is demonstrated by using singular value decomposition, and an iterative conjugate‐gradient approach is proposed to efficiently solve missing k‐space samples during reconstruction. With its generalized formulation and precise mathematical model, PRUNO reconstruction yields good accuracy, flexibility, and stability. Both computer simulation and in vivo studies have shown that PRUNO produces much better reconstruction quality than generalized autocalibrating partially parallel acquisition (GRAPPA), especially under high accelerating rates. With the aid of PRUNO reconstruction, ultra‐high accelerating parallel imaging can be performed with decent image quality. For example, we have done successful PRUNO reconstruction at a reduction factor of 6 (effective factor of 4.44) with eight coils and only a few autocalibration signal lines. Magn Reson Med, 2011. © 2011 Wiley Periodicals, Inc.
Layer‐specific functional and anatomical MRI of the retina with passband balanced SSFP
Authors: Muir Eric R. , Duong Timothy Q. 
Published: May 2011

AbstractThe retina consists of multiple cellular and synaptic layers and is nourished by two distinct (retinal and choroidal) circulations bounding the retina, separated by an avascular layer. High spatiotemporal resolution, layer‐specific MRI of the retina remains challenging due to magnetic inhomogeneity‐induced artifacts. This study reports passband balanced steady‐state free‐precession (bSSFP) MRI at 45×45×500 μm and 1.6 s temporal resolution to image the mouse retina, overcoming geometric distortion and signal dropout while maintaining rapid acquisition and high signal‐to‐noise ratio. bSSFP images revealed multiple alternating dark‐bright‐dark‐bright retinal layers. Hypoxic (10% O2) inhalation decreased bSSFP signals in the two layers bounding the retina, corresponding to the retinal and choroidal vasculatures. The layer in between showed no substantial response and was assigned the avascular photoreceptor layers. Choroidal responses (−25.9±6.4%, mean±SD, n=6) were significantly (P<0.05) larger than retinal vascular responses (−11.6±2.4%). bSSFP offers very high spatiotemporal resolution and could have important applications in imaging layer‐specific changes in retinal diseases. Magn Reson Med, 2011. © 2011 Wiley Periodicals, Inc.
Results for diffusion‐weighted imaging with a fourth‐channel gradient insert
Authors: Feldman Rebecca E. , Scholl Timothy J , Alford Jamu K. , Handler William B. , Harris Chad T. , Chronik Blaine A. 
Published: May 2011

AbstractDiffusion‐weighted imaging suffers from motion artifacts and relatively low signal quality due to the long echo times required to permit the diffusion encoding. We investigated the inclusion of a noncylindrical fourth gradient coil, dedicated entirely to diffusion encoding, into the imaging system. Standard three‐axis whole body gradients were used during image acquisition, but we designed and constructed an insert coil to perform diffusion encodings. We imaged three phantoms on a 3‐T system with a range of diffusion coefficients. Using the insert gradient, we were able to encode b values of greater than 1300 s/mm2 with an echo time of just 83 ms. Images obtained using the insert gradient had higher signal to noise ratios than those obtained using the whole body gradient: at 500 s/mm2 there was a 18% improvement in signal to noise ratio, at 1000 s/mm2 there was a 39% improvement in signal to noise ratio, and at 1350 s/mm2 there was a 56% improvement in signal to noise ratio. Using the insert gradient, we were capable of doing diffusion encoding at high b values by using relatively short echo times. Magn Reson Med, 2011. © 2011 Wiley Periodicals, Inc.
Surgery in Global Health Delivery
Authors: Ozgediz Doruk , Chu Kathryn , Ford Nathan , Dubowitz Gerald , Bedada Alemayehu Ginbo , Azzie Georges , Gerstle J. Ted , Riviello Robert 
Published: May 2011

AbstractSurgical conditions account for a significant portion of the global burden of disease and have a substantial impact on public health in low‐ and middle‐income countries. This article reviews the significance of surgical conditions within the context of public health in these settings, and describes selected approaches to global surgery delivery in specific contexts. The discussion includes programs in global trauma care, surgical care in conflict and disaster, and anesthesia and perioperative care. Programs to develop surgical training in Botswana and pediatric surgery through international partnership are also described, with a final review of broader approaches to training for global surgical delivery. In each instance, innovative solutions, as well as lessons learned and reasons for program failure, are highlighted. Mt Sinai J Med 78:327–341, 2011. © 2011 Mount Sinai School of Medicine
Mixed finite element methods for a fourth order reaction diffusion equation
Authors: Danumjaya P. , Pani Amiya K. 
Published: May 2011

AbstractMixed finite element methods are applied to a fourth order reaction diffusion equation with different types of boundary conditions. Some a priori bounds are established with the help of Lyapunov functional. The semidiscrete schemes are derived using C0‐piecewise linear finite elements in spatial direction and error estimates are obtained. The semidiscrete problem is then discretized in the temporal direction using backward Euler method and the wellposedness of the completely discrete scheme is discussed. Finally, a priori error estimates are established. While deriving a priori error estimates, Gronwall's lemma is applied and the constants involved in the error bounds do not depend exponentially on
\documentclass{article} \usepackage{amsmath, amsthm, amssymb, amsfonts}\pagestyle{empty}\begin{document}$\frac{1}{\gamma}$ \end{document}, where γ is a parameter appeared in the fourth order derivative. © 2011Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2012
Increase in the length of incarceration and the subsequent labor market outcomes: Evidence from men released from Illinois state prisons
Authors: Jung Haeil 
Published: May 2011

AbstractThe sharp rise in U.S. incarceration rates has heightened long‐standing concerns among scholars and policymakers that lengthy incarceration permanently harms the future labor market outcomes of prisoners. If true, then lengthy prison sentences will not only punish criminals for crimes committed, but will also make it far more difficult for ex‐prisoners to reenter society as productive citizens. To investigate this claim I examine how increase in duration of incarceration affects subsequent earnings and employment. Comparing long‐serving prisoners with short‐serving ones in the Illinois state prison system, I find that the length of incarceration is positively associated with earnings and employment, even though these effects attenuate over time. The positive effects are stronger for individuals convicted of economically motivated and less violent crimes (such as property‐ and drug‐related offenses) than for those convicted of violent crimes (such as person‐related offenses). The effect is also stronger for prison entrants with self‐reported drug addiction problems. The deterrent effect of lengthy incarceration and rehabilitation during incarceration are possible reasons for this positive effect. However, because this paper analyzes men who served less than four years in Illinois prison and excludes the population of men who served their terms exclusively in jail, readers should be cautious about generalizing findings of this paper. © 2011 by the Association for Public Policy Analysis and Management.