bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modeling Freshwater Reservoir Offsets on Radiocarbon-Dated Charred Cooking Residues
Authors: Hart John P. , Lovis William A. , Urquhart Gerald R. , Reber Eleanora A. 
Published: July 2013

AbstractObtaining radiocarbon assays on objects of chronological interest is always preferable to obtaining assays on spatially associated charcoal. The development of Accelerator Mass Spectrometer (AMS) dating has expanded the number of objects that can be directly assayed because it requires only a few milligrams of material. Pottery can be directly assayed when charred cooking residues adhering to the interior walls are present. The accuracy of AMS ages derived from residues has been questioned in cases where cooking freshwater aquatic organisms may have introduced carbon from ancient carbon reservoirs into residues. Here we provide analytic protocols for examination of this phenomenon and the results of systematic modeling of age estimates on residues formed from fish and maize with varying percentages of dead carbon. We present a regional case study using a large series of AMS age estimates on residues from the Finger Lakes region of northeastern United States to demonstrate how the paleolimnological record and lipid analysis of residues can help to determine if dates on residues from a given region are likely to have been affected by the presence of ancient carbon. In the case of the Finger Lakes, there is no evidence that ancient carbon affected the age estimates.
A New Design and Application of Bioelastomers for Better Control of Intraocular Pressure in a Glaucoma Drainage Device
Authors: Luong Quang Minh , Shang Lei , Ang Marcus , Kong Jen Fong , Peng Yan , Wong Tina T. , Venkatraman Subbu S. 
Published: July 2013

AbstractGlaucoma drainage device (GDD) implantation is an effective method of lowering the intraocular pressure (IOP). Commonly used GDDs can be classified into nonvalved and valved. Although a stable IOP is critical, currently available devices often cause extreme IOP fluctuations: nonvalved GDDs suffer from a risk of hypotony (IOP < 5 mmHg), whereas valved GDDs have a higher risk ocular hypertensive (IOP > 22 mmHg). It is hypothesized that a GDD with a valve designed to open around the time of onset of the hypertensive phase, would minimize IOP fluctuation. Accordingly, a valve fabricated from a biodegradable polymer poly(L ‐lactide‐co ‐ϵ‐caprolactone) (PLC 70/30) is evaluated in vitro and in vivo. The pressure response is compared with its non‐degradable counterpart in in vitro studies of IOP. It is also established that in vitro, the biodegradability of the valve is programmed to occur over 12 weeks. In vivo, a steady and low IOP is achieved with the biodegradable valve and the hypertensive phase is significantly attenuated compared with the commercial device. Fibrotic encapsulation of the device is also minimized with the biodegradable valve in vivo.
Organic Syntheses with Photochemically Generated Chemicals from Tetrachloroethylene
Authors: Zhang Ailing , Kuwahara Yuki , Hotta Yasuhisa , Tsuda Akihiko 
Published: July 2013

AbstractChlorine, phosgene, and trichloroacetyl chloride are some of the complex mixture of multiple products that is obtained from the oxidative photodecomposition of tetrachloroethylene. These toxic but important reagents in organic synthesis can generated and used in situ for practical syntheses of ureas, amides, carbonates, esters, carbamates, enaminones, and organochlorides.
The tribological properties of poly(p‐phenylene benzobisoxazole) pulp reinforced friction materials
Authors: Liu Rongbiao , Li Xinxin , Liu Xiaoyun , Shen Benben , Han Zhewen 
Published: July 2013

ABSTRACTAutomotive friction materials reinforced by home‐made poly (p‐phenylene benzobisoxazole) (PBO) pulp (fibrillated organic fibers) were prepared through compression molding. The friction and wear behaviors of the obtained composite materials were evaluated using a constant rotating speed type friction tester. The PBO pulp content and the testing loads showed clear influence on the tribological properties of the composites. Friction stability, wear rate, and morphology of sliding surfaces were carefully examined to investigate the effect of the pulp ingredient in the friction materials. Scanning electron microscopy was employed to study the morphology of the surface and wear particles. The significant wear reduction was achieved when the mass fraction of PBO pulp was 3%. Wear rates of the composites with 3% PBO pulp were measured over a load range from 0.3 to 1 MPa at different temperatures. The results pointed to two facts: (1) the wear rate of the friction material increased linearly with load at low temperature (below 200°C); (2) wear status varied with the testing loads at high temperature (above 250°C). © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 4032–4039, 2013
Investigation into the adsorption of a commercial coupling agent for polymers onto pretreated fly ash filler particles
Authors: Velado David , Potgieter Herman , Liauw Christopher Mark 
Published: July 2013

ABSTRACTFly ash can be used as a filler in polymer composite materials. Two fly ash samples (one from the UK, UKFA, and another one from South Africa, SAFA) were washed with water and HCl and compared to investigate their interaction with a commercial coupling agent employed to enhance their incorporation into the polymer matrix. The removal of certain ions from the filler surface resulted in a decrease in the heat of adsorption values due to the reduced number of linkage points for the coupling agent. The coupling agent‐filler interaction was possible for some of the metals of the second group (calcium, magnesium, and sodium) and some of the “p” group (aluminum, sulfur, and phosphorous) on the surface of fly ash. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3985–3992, 2013
Temperature‐dependent pyrolytic product evolution profile for polyethylene terephthalate
Authors: Hujuri Ujwala , Ghoshal Aloke K. , Gumma Sasidhar 
Published: July 2013

ABSTRACTIn this study, a detailed gas chromatographic study of pyrolysis products of polyethylene terephthalate (PET) has been carried out over a wide range of temperature (200–600°C). At low pyrolysis temperatures (200–300°C), yield of lighter hydrocarbons (C5–C10) is low; this gradually increases until maximum decomposition temperature (435°C) and decreases thereafter. At low temperature, PET essentially decomposes by ionic mechanism. However, at higher temperature, it may also proceed by radical mechanism. The following reaction types were considered to explain the decomposition mechanism of PET: (a) heterolytic (ionic) main‐chain cleavage to form an olefin‐end and an acid‐end structure; (b) intra‐ or intermolecular ester‐interchange reactions to yield cyclic oligomers; (c) intramolecular hydrogen transfer to form volatile products and regeneration of the acid‐ends or, olefin‐ends; (d) decarboxylation and intramolecular elimination of acetaldehyde, and acetylene; and (e) hydrogen abstraction and acetylene addition mechanism for the formation of polycyclic aromatic hydrocarbons. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3993–4000, 2013
Insufficient Autoantigen Presentation and Failure of Tolerance in a Mouse Model of Rheumatoid Arthritis
Authors: Perera Jason , Liu Xiao , Zhou Yuzhen , Joseph Nora E. , Meng Liping , Turner Jerrold R. , Huang Haochu 
Published: July 2013

ObjectiveIn the K/BxN mouse model of rheumatoid arthritis, T cells reactive for the self antigen glucose‐6‐phosphate isomerase (GPI) escape negative selection even though GPI expression is ubiquitous. We sought to determine whether insufficient GPI presentation could account for the failure of negative selection and for the development of arthritis.MethodsTo increase the antigen presentation of GPI, we generated transgenic mice expressing a membrane‐bound form of GPI (mGPI) and crossed them with K/BxN mice. A monoclonal antibody specific for the α‐chain of the KRN T cell receptor was generated to examine the fate of GPI‐specific T cells.ResultsThe mGPI‐transgenic mice presented GPI more efficiently and showed a dramatic increase in negative selection and an inhibition of arthritis. Interestingly, thymic negative selection remained incomplete in these mice, and the escaped autoreactive T cells were anergic in the peripheral lymphoid organs, suggesting that enhanced antigen presentation also induces peripheral tolerance. Despite this apparent tolerance induction toward GPI, these mice developed a chronic wasting disease, characterized by colonic inflammation with epithelial dysplasia, as well as a dramatic reduction in Treg cells.ConclusionThese data indicate that insufficient autoantigen expression or presentation results in defects of both central and peripheral tolerance in the K/BxN mice. Our findings also support the idea that insufficient autoantigen levels may underlie the development of autoimmunity.
Solution‐Mediated Phase Transformation of a Hydrate to its Anhydrous Form of Donepezil Hydrochloride
Authors: Liu T. , Wang B. , Dong W. , Gong J. 
Published: July 2013

AbstractThe solubility of form I (hydrate) and form III (anhydrous form) of donepezil hydrochloride (DHCl) in methanol/isopropyl ether mixtures was determined at different temperatures by a synthetic method with laser monitoring observation. The experimental data were correlated with the modified Apelblat equation. Dissolution enthalpy and entropy were predicted by this equation. The mechanisms involved in solution‐mediated transformation of a hydrate (form I) to its anhydrous form (form III) was investigated and characterized by in situ and offline measurement technologies, such as focused‐beam reflectance measurement (FBRM), powder X‐ray diffraction (PXRD), differential scanning calorimetry analysis (DSC), and moisture analyzer. The transformation involves nucleation of the metastable solid (form I), dissolution of the metastable solid, self‐recognition of the molecular units to nucleate a more stable solid phase (form III), and growth of the stable phase. The results indicate that the rate of transformation increases with increasing temperature and driving force.
The new ESA satellite‐only gravity field model via the direct approach
Authors: Bruinsma Sean L. , Förste Christoph , Abrikosov Oleg , Marty Jean‐Charles , Rio Marie‐Helene , Mulet Sandrine , Bonvalot Sylvain 
Published: July 2013

AbstractReprocessed Gravity Field and Steady‐State Ocean Circulation Explorer (GOCE) gravity gradient data were combined with data from Laser Geodynamics Satellite (LAGEOS) 1/2 and Gravity Recovery and Climate Experiment (GRACE) to generate a satellite‐only gravity field model to degree 260 using the direct approach, named DIR‐R4. When compared to Earth Gravitational Model 2008 (EGM2008), it is more accurate at low to medium resolution thanks to GOCE and GRACE data. When compared to earlier releases of ESA GOCE models, it is more accurate at high degrees owing to the larger amount of data ingested. It is also slightly more accurate than ESA's fourth release of the time‐wise model (TIM‐R4), as demonstrated by GPS/leveling, orbit determination tests, and an oceanographic evaluation. According to the formal, probably too optimistic by a factor of 2–2.5, cumulated geoid (1.3 cm) and gravity anomaly (0.4 mGal) errors at 100 km resolution, the GOCE mission objectives have been reached.
Earlier onset of the Indian monsoon in the late twentieth century: The role of anthropogenic aerosols
Authors: Bollasina Massimo A. , Ming Yi , Ramaswamy V. 
Published: July 2013

AbstractThe impact of the late twentieth century increase of anthropogenic aerosols on the Indian monsoon onset was investigated with a state‐of‐the‐art climate model with fully interactive aerosols and chemistry. We find that aerosols are likely responsible for the observed earlier onset, resulting in enhanced June precipitation over most of India. This shift is preceded by strong aerosol forcing over the Bay of Bengal and Indochina, mostly attributable to the direct effect, resulting in increased atmospheric stability that inhibits the monsoon migration in May. The adjusted atmospheric circulation leads to thermodynamic changes over the northwestern continental region, including increased surface temperature and near‐surface moist static energy, which support a stronger June flow and, facilitated by a relative warming of the Indian Ocean, a vigorous northwestward precipitation shift. These findings underscore the importance of dynamical feedbacks and of regional land‐surface processes for the aerosol‐monsoon link.
Interannual variability in tropospheric nitrous oxide
Authors: Thompson R. L. , Dlugokencky E. , Chevallier F. , Ciais P. , Dutton G. , Elkins J. W. , Langenfelds R. L. , Prinn R. G. , Weiss R. F. , Tohjima Y. , O'Doherty S. , Krummel P. B. , Fraser P. , Steele L. P. 
Published: July 2013

AbstractObservations of tropospheric N2O mixing ratio show significant variability on interannual timescales (0.2 ppb, 1 standard deviation). We found that interannual variability in N2O is weakly correlated with that in CFC‐12 and SF6 for the northern extratropics and more strongly correlated for the southern extratropics, suggesting that interannual variability in all these species is influenced by large‐scale atmospheric circulation changes and, for SF6 in particular, interhemispheric transport. N2O interannual variability was not, however, correlated with polar lower stratospheric temperature, which is used as a proxy for stratosphere‐to‐troposphere transport in the extratropics. This suggests that stratosphere‐to‐troposphere transport is not a dominant factor in year‐to‐year variations in N2O growth rate. Instead, we found strong correlations of N2O interannual variability with the Multivariate ENSO Index. The climate variables, precipitation, soil moisture, and temperature were also found to be significantly correlated with N2O interannual variability, suggesting that climate‐driven changes in soil N2O flux may be important for variations in N2O growth rate.
Microstructural Failure Mechanisms in the Human Proximal Femur for Sideways Fall Loading
Authors: Nawathe Shashank , Akhlaghpour Hosna , Bouxsein Mary L , Keaveny Tony M 
Published: July 2013

ABSTRACT

The etiology of hip fractures remains unclear but might be elucidated by an improved understanding of the microstructural failure mechanisms of the human proximal femur during a sideways fall impact. In this context, we biomechanically tested 12 cadaver proximal femurs (aged 76 ± 10 years; 8 female, 4 male) to directly measure strength for a sideways fall and also performed micro-computed tomography (CT)-based, nonlinear finite element analysis of the same bones (82-micron-sized elements, ∼120 million elements per model) to estimate the amount and location of internal tissue-level failure (by ductile yielding) at initial structural failure of the femur. We found that the correlation between the directly measured yield strength of the femur and the finite element prediction was high (R2 = 0.94, p &lt; 0.0001), supporting the validity of the finite element simulations of failure. In these simulations, the failure of just a tiny proportion of the bone tissue (1.5% to 6.4% across all bones) led to initial structural failure of the femur. The proportion of failed tissue, estimated by the finite element models, decreased with decreasing measured femoral strength (R2 = 0.88, p &lt; 0.0001) and was more highly correlated with measured strength than any measure of bone volume, mass, or density. Volume-wise, trabecular failure occurred earlier and was more prominent than cortical failure in all femurs and dominated in the very weakest femurs. Femurs with low measured strength relative to their areal bone mineral density (BMD) (by dual-energy X-ray absorptiometry [DXA]) had a low proportion of trabecular bone compared with cortical bone in the femoral neck (p &lt; 0.001), less failed tissue (p &lt; 0.05), and low structural redundancy (p &lt; 0.005). We conclude that initial failure of the femur during a sideways fall is associated with failure of just a tiny proportion of the bone tissue, failure of the trabecular tissue dominating in the very weakest femurs owing in part to a lack of structural redundancy. © 2014 American Society for Bone and Mineral Research.
Diet-Derived Phenolic Acids Regulate Osteoblast and Adipocyte Lineage Commitment and Differentiation in Young Mice
Authors: Chen Jin-Ran , Lazarenko Oxana P , Zhang Jian , Blackburn Michael L , Ronis Martin JJ , Badger Thomas M 
Published: July 2013

ABSTRACT

A blueberry (BB)-supplemented diet has been previously shown to significantly stimulate bone formation in rapidly growing male and female rodents. Phenolic acids (PAs) are metabolites derived from polyphenols found in fruits and vegetables as a result of the actions of gut bacteria, and they were found in the serum of rats fed BB-containing diet. We conducted in vitro studies with PAs and demonstrated stimulation of osteoblast differentiation and proliferation. On the other hand, adipogenesis was inhibited. To more fully understand the mechanistic actions of PAs on bone formation, we administered hippuric acid, one of the major metabolites found in animal circulation after BB consumption, to prepubertal female mice for 2 weeks. We found that hippuric acid was able to stimulate bone-forming gene expression but suppress PPARγ expression, leading to increased bone mass dose-dependently. Cellular signaling studies further suggested that the skeletal effects of PAs appeared to be mediated through activation of G-protein-coupled receptor 109A and downstream p38 MAP kinase and osterix. In conclusion, PAs are capable of altering the mesenchymal stem cell differentiation program and merit investigation as potential dietary therapeutic alternatives to drugs for degenerative bone disorders. © 2014 American Society for Bone and Mineral Research.
Intravenous Treatment With Ibandronate Normalizes Bone Matrix Mineralization and Reduces Cortical Porosity After Two Years in Male Osteoporosis: A Paired Biopsy Study
Authors: Misof Barbara M , Patsch Janina M , Roschger Paul , Muschitz Christian , Gamsjaeger Sonja , Paschalis Eleftherios P , Prokop Eva , Klaushofer Klaus , Pietschmann Peter , Resch Heinrich 
Published: July 2013

ABSTRACT

The spectrum of therapeutic options and the amount of clinical trials for male osteoporosis (mOP) is lower than those for postmenopausal osteoporosis. Therefore, we examined the effects of 24 months of ibandronate (IBN) treatment (3 mg/3 mL intravenously every 3 months) on bone material quality in 19 subjects with mOP within an open-label, single-center, prospective phase III study (Eudract number 2006-006692-20). Patients (median age [25th, 75th percentiles] 53.0 [44.5; 57.0] years) were included if they had low bone mineral density (BMD) and/or at least one low trauma fracture and no secondary cause of osteoporosis. The primary endpoint was to evaluate IBN effects on cancellous (Cn.) and cortical (Ct.) bone mineralization density distribution (BMDD) based on quantitative backscattered electron imaging (qBEI) of paired transiliacal bone biopsies (baseline, 24 months). Secondary endpoints included changes in areal bone mineral density (BMD by dual-energy X-ray absorptiometry [DXA]) and serum markers of bone turnover including type I collagen peptides CrossLaps (CTX), procollagen type 1 amino-terminal propeptide (P1NP), and osteocalcin (OC). At baseline, cancellous bone matrix mineralization from mOP was lower than published reference data (mean degree of mineralization Cn.CaMean −1.8%, p &lt; 0.01). IBN treatment increased calcium concentrations versus baseline (Cn.CaMean +2.4%, Ct.CaMean, +3.0% both p &lt; 0.01), and reduced heterogeneity of mineralization (Cn.CaWidth −14%, p = 0.044; Ct.CaWidth, −16%, p = 0.001), leading to cancellous BMDD within normal range. IBN treatment was associated with a decrease in porosity of mineralized cortical tissue (−25%, p = 0.01); increases in BMD at the lumbar spine, the femoral neck, and the total hip (+3.3%, +1.9%, and +5.6%, respectively, p ≤ 0.01); and reductions in CTX (−37.5%), P1NP (−44.4%), and OC (−36.3%, all p &lt; 0.01). Our BMDD findings are in line with the reduction of bone turnover markers and the increase in BMD by IBN in our patients and suggest that the latter mainly reflects the increase in matrix mineralization and the reduction of cortical porosity in this cohort with mOP. © 2014 American Society for Bone and Mineral Research.
Rapid healing of femoral defects in rats with low dose sustained BMP2 expression from PEGDA hydrogel microspheres
Authors: Sonnet Corinne , Simpson C. LaShan , Olabisi Ronke M. , Sullivan Kayleigh , Lazard ZaWaunyka , Gugala Zbigniew , Peroni John F. , Weh J. Michael , Davis Alan R. , West Jennifer L. , Olmsted‐Davis Elizabeth A. 
Published: July 2013

ABSTRACTCurrent strategies for bone regeneration after traumatic injury often fail to provide adequate healing and integration. Here, we combined the poly (ethylene glycol) diacrylate (PEGDA) hydrogel with allogeneic “carrier” cells transduced with an adenovirus expressing BMP2. The system is unique in that the biomaterial encapsulates the cells, shielding them and thus suppressing destructive inflammatory processes. Using this system, complete healing of a 5 mm‐long femur defect in a rat model occurs in under 3 weeks, through secretion of 100‐fold lower levels of protein as compared to doses of recombinant BMP2 protein used in studies which lead to healing in 2–3 months. New bone formation was evaluated radiographically, histologically, and biomechanically at 2, 3, 6, 9, and 12 weeks after surgery. Rapid bone formation bridged the defect area and reliably integrated into the adjacent skeletal bone as early as 2 weeks. At 3 weeks, biomechanical analysis showed the new bone to possess 79% of torsional strength of the intact contralateral femur. Histological evaluation showed normal bone healing, with no infiltration of inflammatory cells with the bone being stable approximately 1 year later. We propose that these osteoinductive microspheres offer a more efficacious and safer clinical option over the use of rhBMP2. © 2013 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 31:1597–1604, 2013
Tibiofemoral centroid velocity correlates more consistently with cartilage damage than does contact path length in two ovine models of stifle injury
Authors: Beveridge Jillian E. , Heard Bryan J. , Shrive Nigel G. , Frank Cyril B. 
Published: July 2013

ABSTRACTAnterior cruciate ligament (ACL) rupture and/or meniscal injury are known risk factors for post‐traumatic osteoarthritis. We tested the hypothesis that increasingly abnormal tibiofemoral centroid path lengths and velocities would correlate with the severity of cartilage damage in injured sheep. Six sheep underwent combined ACL/medial collateral ligament transection (ACL/MCLx), five complete lateral meniscectomy (Mx), and four sham arthrotomy (Sham). Weighted centroids were used to estimate in vivo tibiofemoral cartilage contact path length during stance and the velocity of relative motion. Cartilage morphology was graded at dissection. Ligament transection significantly elongated plateau centroid path lengths and velocities, whereas condyle paths and velocities were reduced. Differences between plateau and femoral velocities (relative centroid velocity) were increased up to 10‐fold over baseline values in the medial compartment. Reductions in Mx lateral compartment paths were significantly different from ACL/MCLx paths, but not relative to baseline or Sham values. Importantly, only centroid velocities consistently correlated with cartilage damage in either injury model, suggesting that while path length is valuable in detecting changes in the envelope of joint motion, it may average out meaningful peaks in the rate of relative motion that more closely relate to the mechanisms that might be damaging articular cartilage in these models. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31:1745–1756, 2013