bluuebunny/crossref_metadata_2025 huggingface dataset:
A Family of Calix[4]arene‐Supported [MnIII2MnII2] Clusters
Authors: Taylor Stephanie M. , Karotsis Georgios , McIntosh Ruaraidh D. , Kennedy Stuart , Teat Simon J. , Beavers Christine M. , Wernsdorfer Wolfgang , Piligkos Stergios , Dalgarno Scott J. , Brechin Euan K.
Published: May 2011

In the cone conformation calix[4]arenes possess lower‐rim polyphenolic pockets that are ideal for the complexation of various transition‐metal centres. Reaction of these molecules with manganese salts in the presence of an appropriate base (and in some cases co‐ligand) results in the formation of a family of calixarene‐supported [MnIII2MnII2] clusters that behave as single‐molecule magnets (SMMs). Variation in the alkyl groups present at the upper‐rim of the cone allows for the expression of a degree of control over the self‐assembly of these SMM building blocks, whilst retaining the general magnetic properties. The presence of various different ligands around the periphery of the magnetic core has some effect over the extended self‐assembly of these SMMs.
Furan‐Oxidation‐Triggered Inducible DNA Cross‐Linking: Acyclic Versus Cyclic Furan‐Containing Building Blocks—On the Benefit of Restoring the Cyclic Sugar Backbone
Authors: Stevens Kristof , Claeys Diederica D. , Catak Saron , Figaroli Sara , Hocek Michal , Tromp Jan M. , Schürch Stefan , Van Speybroeck Veronique , Madder Annemieke
Published: May 2011

Oligodeoxynucleotides incorporating a reactive functionality can cause irreversible cross‐linking to the target sequence and have been widely studied for their potential in inhibition of gene expression or development of diagnostic probes for gene analysis. Reactive oligonucleotides further show potential in a supramolecular context for the construction of nanometer‐sized DNA‐based objects. Inspired by the cytochrome P450 catalyzed transformation of furan into a reactive enal species, we recently introduced a furan‐oxidation‐based methodology for cross‐linking of nucleic acids. Previous experiments using a simple acyclic building block equipped with a furan moiety for incorporation into oligodeoxynucleotides have shown that cross‐linking occurs in a very fast and efficient way and that substantial amounts of stable, site‐selectively cross‐linked species can be isolated. Given the destabilization of duplexes observed upon introduction of the initially designed furan‐modified building block into DNA duplexes, we explore here the potential benefits of two new building blocks featuring an extended aromatic system and a restored cyclic backbone. Thorough experimental analysis of cross‐linking reactions in a series of contexts, combined with theoretical calculations, permit structural characterization of the formed species and allow assessment of the origin of the enhanced cross‐link selectivity. Our experiments clearly show that the modular nature of the furan‐modified building blocks used in the current cross‐linking strategy allow for fine tuning of both yield and selectivity of the interstrand cross‐linking reaction.
Catalytic selectivity in complex systems
Authors: Butt John B.
Published: May 2011

Diffusional effects on the three general types of catalytic selectivity are studied for complex, isothermal systems. A variable diffusivity evaluated from pore structure‐diffusion models is used to express the influence of mixed modes of diffusion, multicomponent mixtures, and catalytic pore structure on selectivity.

Selectivity in complex systems is, in general, lower than that estimated from constant diffusivity analysis, although an optimum particle density may exist for certain cases of parallel reaction. The quantitative estimation of selectivity in complex systems requires some detail on the properties of the reaction and catalyst under study.
Recent Advances in Vegetable Oil‐Based Polyurethanes
Authors: Pfister Daniel P. , Xia Ying , Larock Richard C.
Published: May 2011

Polyurethanes are among the most versatile polymers because of the wide range of monomers, particularly diols or polyols, that can be utilized in their synthesis. This Review focuses on the most recent advances made in the production of polyurethane materials from vegetable oils. Over the past several years, increasing attention has been given to the use of vegetable oils as feedstocks for polymeric materials, because they tend to be very inexpensive and available in large quantities. Using various procedures, a very broad range of polyols or diols and in some cases, poly‐ or diisocyanates, can be obtained from vegetable oils. The wide range of vegetable oil‐based monomers leads to a wide variety of polyurethane materials, from flexible foams to ductile and rigid plastics. The thermal and mechanical properties of these vegetable oil‐based polyurethanes are often comparable to or even better than those prepared from petroleum and are suitable for applications in various industries.
Cytometric assessment of mitochondria using fluorescent probes
Authors: Cottet‐Rousselle Cécile , Ronot Xavier , Leverve Xavier , Mayol Jean‐François
Published: May 2011

Mitochondria are most important organelles in the survival of eukaryotic aerobic cells because they are the primary producers of ATP, regulators of ion homeostasis or redox state, and producers of free radicals. The key role of mitochondria in the generation of primordial ATP for the survival and proliferation of eukaryotic cells has been proven by extensive biochemical studies. In this context, it is crucial to understand the complexity of the mitochondrial compartment and its functionality and to develop experimental tools allowing the assessment of its nature and its function and metabolism. This review covers the role of the mitochondria in the cell, focusing on its structure, the mechanism of the mitochondrial respiratory chain, the maintenance of the transmembrane potential and the production of reactive oxygen species. The main probes used for mitochondrial compartment monitoring are described. In addition, various applications using mitochondrial‐specific probes are detailed to illustrate the potential of flow and image cytometry in the study of the mitochondrial compartment. This review contains a panel of tools to explore mitochondria and to help researchers design experiments, determine the approach to be employed, and interpret their results. © 2011 International Society for Advancement of Cytometry
The identification of transcription factors expressed in the notochord of Ciona intestinalis adds new potential players to the brachyury gene regulatory network
Authors: José‐Edwards Diana S. , Kerner Pierre , Kugler Jamie E. , Deng Wei , Jiang Di , Di Gregorio Anna
Published: May 2011

The notochord is the distinctive characteristic of chordates; however, the knowledge of the complement of transcription factors governing the development of this structure is still incomplete. Here we present the expression patterns of seven transcription factor genes detected in the notochord of the ascidian Ciona intestinalis at various stages of embryonic development. Four of these transcription factors, Fos‐a, NFAT5, AFF and Klf15, have not been directly associated with the notochord in previous studies, while the others, including Spalt‐like‐a, Lmx‐like, and STAT5/6‐b, display evolutionarily conserved expression in this structure as well as in other domains. We examined the hierarchical relationships between these genes and the transcription factor Brachyury, which is necessary for notochord development in all chordates. We found that Ciona Brachyury regulates the expression of most, although not all, of these genes. These results shed light on the genetic regulatory program underlying notochord formation in Ciona and possibly other chordates. Developmental Dynamics 240:1793–1805, 2011. © 2011 Wiley‐Liss, Inc.
A Straightforward Approach towards Isoxazoline Amino Acid Esters by Domino Michael Additions/Nitrile Oxide Cycloadditions
Authors: Wirtz Lisa , Kazmaier Uli
Published: May 2011

The 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

Background

Enteral 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.

Methods

Surveillance, 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).

Results

In 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.

Conclusions

Future 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

Atractyloside 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

Zebrafish, 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

Accumulating 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

Vascular 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

Microbial‐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

We 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

Experimental 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.
Liver transplantation for erythropoietic protoporphyria in Europe
Authors: Wahlin Staffan , Stal Per , Adam Rene , Karam Vincent , Porte Robert , Seehofer Daniel , Gunson Bridget K. , Hillingsφ Jens , Klempnauer Jürgen L. , Schmidt Jan , Alexander Graeme , O'Grady John , Clavien Pierre-Alain , Salizzoni Mauro , Paul Andreas , Rolles Keith , Ericzon Bo-Göran , Harper Pauline
Published: May 2011

Liver transplantation is an established lifesaving treatment for patients with severe protoporphyric liver disease, but disease recurrence in the graft occurs for the majority of recipients. Severe burn injuries may occur when protective light filters are not used with surgical luminaires. Motor neuropathy with an unclear pathogenesis is a frequent complication. We retrospectively studied 35 transplants performed for protoporphyric liver disease in 31 European patients between 1983 and 2008. Most of the patients were male (61.3%), and the mean age at the time of primary transplantation was 39 years (range = 9-60 years). The overall patient survival rates were 77% at 1 year and 66% at 5 and 10 years. The overall rate of disease recurrence in the graft was 69%. Forty-three percent of the patients experienced recurrence within a year, but this was often a transient finding that was associated with other graft complications. Phototoxic injuries due to surgical luminaires were seen in 25.0% of the patients who were not protected by filters, but these injuries were not seen in the 9 patients who were protected by filters. Significant motor neuropathies requiring prolonged ventilation complicated the postoperative course for 5 of the 31 patients (16.1%). Hematopoietic stem cell transplantation was performed for 3 patients to prevent graft loss due to disease recurrence. Prognostic markers are needed to identify patients prone to severe protoporphyric liver disease so that curative stem cell transplantation can be offered to select patients instead of liver transplantation. Liver Transpl 17:1021–1026, 2011. © 2011 AASLD.
Impact of center volume on outcomes of increased-risk liver transplants
Authors: Ozhathil Deepak K. , Li You Fu , Smith Jillian K. , Tseng Jennifer F. , Saidi Reza F. , Bozorgzadeh Adel , Shah Shimul A.
Published: May 2011

The use of high-risk donor livers, which is reflective of the gross national shortage of organs available for transplantation, has gained momentum. Despite the demand, many marginal livers are discarded annually. We evaluated the impact of center volume on survival outcomes associated with liver transplantation using high–donor risk index (DRI) allografts. We queried the Scientific Registry of Transplant Recipients database for deceased donor liver transplants (n = 31,576) performed between 2002 and 2008 for patients who were 18 years old or older, and we excluded partial and multiple liver transplants. A high-DRI cohort (n = 15,668), which was composed of patients receiving grafts with DRIs > 1.90, was analyzed separately. Transplant centers (n = 102) were categorized into tertiles by their annual procedure volumes: high-volume centers (HVCs; 78-215 cases per year), medium-volume centers (MVCs; 49-77 cases per year), and low-volume centers (LVCs; 5-48 cases per year). The endpoints were allograft survival and recipient survival. In comparison with their lower volume counterparts, HVCs used donors with higher mean DRIs (2.07 for HVCs, 2.01 for MVCs, and 1.91 for LVCs), more donors who were 60 years old or older (18.02% for HVCs, 16.85% for MVCs, and 12.39% for LVCs), more donors who died after a stroke (46.52% for HVCs, 43.71% for MVCs, and 43.36% for LVCs), and more donation after cardiac death organs (5.04% for HVCs, 4.45% for MVCs, and 3.51% for LVCs, all P values < 0.001). Multivariate risk-adjusted frailty models showed that increased procedure volume at a transplant center led to decreased risks of allograft failure [hazard ratio (HR) = 0.93, 95% confidence interval (CI) = 0.89-0.98, P = 0.002] and recipient death (HR = 0.90, 95% CI = 0.83-0.97, P = 0.004) for high-DRI liver transplants. In conclusion, HVCs more frequently used higher DRI livers and achieved better risk-adjusted allograft and recipient survival. A greater understanding of the outcomes of transplantation with high-DRI livers may improve their utilization, the postoperative outcomes, and future allocation practices. Liver Transpl 17:1191–1199, 2011. © 2011 AASLD.
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

Many 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

A 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

The 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

Diffusion‐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

Surgical 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

Mixed 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

The 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.
Tailoring of water‐soluble cellulose‐g‐ copolymers in homogeneous medium using single‐electron‐transfer living radical polymerization
Authors: Hiltunen Miia S , Raula Janne , Maunu Sirkka Liisa
Published: May 2011

Cellulose‐graft‐polyacrylamide and cellulose‐graft‐poly(N,N‐dimethylacrylamide) copolymers were prepared by single‐electron‐transfer living radical polymerization (SET‐LRP) in homogeneous medium. Cellulose macroinitiators for SET‐LRP, with different numbers of initiating sites along the cellulose backbone, were successfully synthesized by direct acylation of cellulose with 2‐bromoisobutyryl bromide in LiCl/dimethylacetamide. Dynamic light scattering revealed that cellulose macroinitiator molecules in dimethylsulfoxide (DMSO) exist primarily as individual chains with a certain amount of intermolecular aggregates. SET‐LRP of acrylamide and N,N‐dimethylacrylamide with the cellulose macroinitiators was carried out in DMSO solution. Formation of cellulose‐graft‐copolymers was confirmed using attenuated total reflectance Fourier transform infrared, 1H NMR and 13C NMR spectroscopy, and the products were water‐soluble. High content of poly(N,N‐dimethylacrylamide) in the copolymers enhanced the thermal stability relative to that of cellulose. Scanning electron microscopy studies of cellulose‐based particles formed from the copolymers using the aerosol flow reactor method revealed spherical nanoscale structures. Copyright © 2011 Society of Chemical Industry
Synthesis and properties of novel rosin‐based water‐borne polyurethane
Authors: Xu Xu , Song Zhanqian , Shang Shibin , Cui Shuqin , Rao Xiaoping
Published: May 2011

A series of novel rosin‐based water‐borne polyurethanes (RWPUs) was prepared from fumaropimaric acid polyester polyol (FAPP) synthesised from rosin acid. Emulsions of the prepared RWPUs were investigated by transmission electron microscopy, and dried films of the emulsions were characterised by Fourier transform infrared spectroscopy, thermogravimetric analysis, X‐ray diffraction and differential scanning calorimetry. Other properties including water absorption, tensile strength, elongation at break, and antibacterial activity of the RWPUs were also determined. The results suggest that RWPU prepared with 35 wt% FAPP has good potential for applications, with improved mechanical properties, thermal stability and water resistance. The RWPU showed excellent antimicrobial properties in killing both Gram‐negative Escherichia coli and Gram‐positive Staphylococcus aureus. Copyright © 2011 Society of Chemical Industry
Surface shaving as a versatile tool to profile global interactions between human serum proteins and the Staphylococcus aureus cell surface
Authors: Dreisbach Annette , van der Kooi‐Pol Magdalena M. , Otto Andreas , Gronau Katrin , Bonarius Hendrik P. J. , Westra Hans , Groen Herman , Becher Dörte , Hecker Michael , van Dijl Jan M.
Published: May 2011

The human commensal bacterium Staphylococcus aureus is renowned as a causative agent of severe invasive diseases. Upon entering the bloodstream, S. aureus can infect almost every tissue and organ system in the human body. To withstand insults from the immune system upon invasion, several immune‐evasive mechanisms have evolved in S. aureus, such as complement inhibition by secreted proteins and IgG‐binding by surface‐exposed protein A. While it is generally accepted that S. aureus cells bind a range of host factors for various purposes, no global analyses to profile staphylococcal host factor binding have so far been performed. Therefore, we explored the possibility to profile the binding of human serum proteins to S. aureus cells by “surface shaving” with trypsin and subsequent MS analysis of liberated peptides. This resulted in the identification of several components of the complement system, the platelet factor 4 and the isoform 1 of the inter‐α‐trypsin inhibitor heavy chain H4 on the staphylococcal cell surface. We conclude that surface shaving is a versatile tool to profile global interactions between human serum proteins and the S. aureus cell surface.
Uptake, translocation and metabolism of aminocyclopyrachlor in prickly lettuce, rush skeletonweed and yellow starthistle
Authors: Bell Jared L , Burke Ian C , Prather Timothy S
Published: May 2011

BACKGROUND: Aminocyclopyrachlor is a new herbicide proposed to control broadleaf weeds and shrubs in non‐crop and rangeland systems. To gain a better understanding of observed field efficacy, the uptake and translocation of foliar‐applied aminocyclopyrachlor (DPX‐MAT28) and aminocyclopyrachlor methyl ester (DPX‐KJM44) were evaluated in two annuals, prickly lettuce (Lactuca serriola L.) and yellow starthistle (Centaurea solstitialis L.), and one perennial, rush skeletonweed (Chondrilla juncea L.).

RESULTS: Absorption and translocation varied between species. While absorption of DPX‐KJM44 was greater than absorption of DPX‐MAT28, rush skeletonweed absorbed the most, followed by yellow starthistle and prickly lettuce. Overall, the total translocation of either herbicide was highest in yellow starthistle, followed by rush skeletonweed and prickly lettuce. Proportional herbicide movement between species was similar, with the majority translocating to developing shoots. However, in rush skeletonweed, early translocation was directed to root tissue. In rush skeletonweed, no DPX‐MAT28 metabolism occurred, while DPX‐KJM44 was rapidly de‐esterified and translocated as DPX‐MAT28.

CONCLUSION: Aminocyclopyrachlor absorption and translocation are dependent on active ingredient structure and species sensitivity. Highly sensitive species such as prickly lettuce absorb and translocate less material than relatively less sensitive species such as rush skeletonweed. De‐esterification of DPX‐KJM44 appears to delay translocation of the resulting acid in yellow starthistle and rush skeletonweed. Copyright © 2011 Society of Chemical Industry
Carbon‐tuned cathodoluminescence of semi‐insulating GaN
Authors: Kakanakova‐Georgieva A. , Forsberg U. , Janzén E.
Published: May 2011

We report on the cathodoluminescence (CL) of nominally undoped semi‐insulating GaN layers grown by hot‐wall metal‐organic chemical vapor deposition (MOCVD) at a threefold increase of the growth rate limited by the TMGa flow. The growth kinetics is such, that C is the only background impurity in the layers with controllably increasing concentration from 5 × 1016 to 6 × 1017 cm−3, while other background impurities, H, O and Si, are essentially at the SIMS detection levels. The hot‐wall MOCVD is not an ordinary approach to GaN growth process and this study corroborates a more perceptive outlook on the C incorporation in GaN and any potential C‐incorporation‐mediated luminescence, including the observed here blue luminescence (BL) at ∼417 nm, and the yellow luminescence (YL) with shifting peak position towards shorter wavelengths, ∼555–543–525 nm.
Liquid chromatography/tandem mass spectrometry based targeted proteomics quantification of P‐glycoprotein in various biological samples
Authors: Zhang Yiqun , Li Na , Brown Paul W. , Ozer Josef S. , Lai Yurong
Published: May 2011

P‐Glycoprotein (P‐gp/ABCB1) is expressed in membrane barriers to exclude pharmacological substrates from cells, and therefore influences the ADME/Tox properties and efficacy of therapeutics. In the present study, a liquid chromatography/tandem mass spectrometry (LC/MS/MS)‐mediated targeted proteomics was developed to quantitate P‐gp protein. With the aid of in silico predictive tools, a unique 9‐mer tryptic peptide of P‐gp protein was synthesized (with the stable isotope labeled (SIL) peptide as internal standard) and applied for quantitative LC/MS/MS method development. For LC/MS/MS quantification, the N‐glycosylation of the peptide, polymorphism and transmembrane region was intended to be excluded during the peptide selection. The lower limit of quantification was established to be 0.025 nM with the linearity of the standard curve ranging to 20 nM of P‐gp signature peptides in the matrix digested surrogate bovine serum albumin. The digestion efficiency, both the accuracy (relative error) and the precision (coefficient of variation) of the method, was verified by using the synthetic quantification peptide and the synthetic surrogate substrate peptide that mimics the sequence of tryptic peptide and associated flanking tryptic cleavage sites at the N‐ and C‐terminals. By applying the method developed, the absolute amounts of human, dog and mouse P‐gp (Mdr1a) were quantified in various biological samples. LC/MS/MS‐mediated P‐gp quantification was achieved as a highly sensitive, selective and reproducible assay and could be directly applicable to many current research needs related to P‐gp. Copyright © 2011 John Wiley & Sons, Ltd.
Formation of aluminium, aluminium nitride and nitrogen clusters via laser ablation of nano aluminium nitride. Laser desorption ionisation and matrix‐assisted laser desorption ionisation time‐of‐flight mass spectrometry
Authors: Panyala Nagender Reddy , Prysiazhnyi Vadym , Slavíček Pavel , Černák Mirko , Havel Josef
Published: May 2011

Laser Desorption Ionisation (LDI) and Matrix‐Assisted Laser Desorption Ionisation (MALDI) Time‐of‐Flight Mass Spectrometry (TOFMS) were used to study the pulsed laser ablation of aluminium nitride (AlN) nano powder. The formation of Alm+ (m = 1–3), Nn+ (n = 4, 5), AlNn+ (n = 1–5, 19, 21), AlmN+ (m = 2–3), Al3N2+, Al9Nn+ (n = 5, 7, 9, 11 and 15), Al11Nn+ (n = 4, 6, 10, 12, 19, 21, 23, and 25), and Al13Nn+ (n = 25, 31, 32, 33, 34, 35, and 36) clusters was detected in positive ion mode. Similarly, Alm– (m = 1–3), AlNn– (n = 1–3, 5), AlmN– (m = 2, 3), Al2Nn– (n = 2–4, 28, 30), Nn– (n = 2, 3), Al4N7–, Al8Nn– (n = 1–6), and Al13Nn– (n = 9, 18, 20, 22, 24, 26, 28, 33, 35, 37, 39, 41 and 43) clusters were observed in negative ion mode. The formation of the stoichiometric Al10N10 cluster was shown to be of low abundance. On the contrary, the laser ablation of nano‐AlN led mainly to the formation of nitrogen‐rich AlmNn clusters in both negative and positive ion mode. The stoichiometry of the AlmNn clusters was determined via isotopic envelope analysis and computer modelling. Copyright © 2011 John Wiley & Sons, Ltd.
Radar‐based perception for autonomous outdoor vehicles
Authors: Reina Giulio , Underwood James , Brooker Graham , Durrant‐Whyte Hugh
Published: May 2011

Autonomous vehicle operations in outdoor environments challenge robotic perception. Construction, mining, agriculture, and planetary exploration environments are examples in which the presence of dust, fog, rain, changing illumination due to low sun angles, and lack of contrast can dramatically degrade conventional stereo and laser sensing. Nonetheless, environment perception can still succeed under compromised visibility through the use of a millimeter‐wave radar. Radar also allows for multiple object detection within a single beam, whereas other range sensors are limited to one target return per emission. However, radar has shortcomings as well, such as a large footprint, specularity effects, and limited range resolution, all of which may result in poor environment survey or difficulty in interpretation. This paper presents a novel method for ground segmentation using a millimeter‐wave radar mounted on a ground vehicle. Issues relevant to short‐range perception in an outdoor environment are described along with field experiments and a quantitative comparison to laser data. The ability to classify the ground is successfully demonstrated in clear and low‐visibility conditions, and significant improvement in range accuracy is shown. Finally, conclusions are drawn on the utility of millimeter‐wave radar as a robotic sensor for persistent and accurate perception in natural scenarios. © 2011 Wiley Periodicals, Inc.