bluuebunny/crossref_metadata_2025_split huggingface dataset:
Heterogeneity of fracture pathogenesis in urban South African children: The birth to twenty cohort
Authors: Thandrayen Kebashni , Norris Shane A , Micklesfield Lisa K , Pettifor John M 
Published: August 2011

Abstract
South African black children fracture less than white children. Differences in bone mass, body composition, and physical activity may be contributing risk factors. This study aimed to investigate the association between fracture prevalence, bone mass, and physical activity in South African children. Using the Bone Health cohort of the Birth to Twenty longitudinal study, we retrospectively obtained information of lifetime fractures until age 15 years in 533 subjects. Whole-body bone mineral content (BMC), bone area (BA), fat mass (FM), and lean mass (LM) (measured by dual-energy X-ray absorptiometry [DXA]), anthropometric data, physical activity scores, and skeletal maturity were obtained at ages 10 and 15 years. Nonfracturing black females were used as the control group and comparisons were made between those who did and did not fracture within the same sex and ethnic groups. Of the 533 subjects, 130 (24%) reported a fracture (black, 15%; white, 41.5%; p &lt; 0.001). White males who fractured were significantly taller (10 years, p &lt; 0.01), more physically active (15 years, p &lt; 0.05) and had higher LM (10 years, p = 0.01; 15 years, p &lt; 0.001), whereas white females who fractured were fatter (10 and 15 years, p = 0.05 and p &lt; 0.05, respectively), than their nonfracturing peers. White males who fractured had greater BA and BMC at all sites at 10 and 15 years compared to their nonfracturing peers after adjusting for differences in height and weight; BA and BMC were similar in each of the other sex and ethnic groups. No anthropometric or bone mass differences were found between black children with and without fractures. The factor associated with fractures in white males appears to be participation in sports activities, while in white females obesity appears to play a role. No contributing factors in black males and females were found, and needs further elucidation. © 2011 American Society for Bone and Mineral Research
Xanthohumol‐supplemented beer modulates angiogenesis and inflammation in a skin wound healing model. Involvement of local adipocytes
Authors: Negrão Rita , Costa Raquel , Duarte Delfim , Gomes Tiago Taveira , Coelho Pedro , Guimarães João T. , Guardão Luísa , Azevedo Isabel , Soares Raquel 
Published: August 2011

AbstractAngiogenesis and inflammation are two intermingled processes that play a role in wound healing. Nevertheless, whenever exacerbated, these processes result in nonhealing wounds. Xanthohumol (XN), a beer‐derived polyphenol, inhibits these processes in many physiopathological situations. This study aimed at examining whether XN ingestion affects wound healing. Wistar rats drinking water, 5% ethanol, stout beer (SB) or stout beer supplemented with 10 mg/L XN (Suppl SB) for 4 weeks, were subjected to a 1.5 cm full skin‐thickness longitudinal incision, and further maintained under the same beverage conditions for another week. No differences in beverage consumption or body weight were found throughout the study but food intake decreased in every group relative to controls. Consumption of Suppl SB resulted in decreased serum VEGF levels (18.42%),N‐acetylglucosaminidase activity (27.77%), IL1β concentration (9.07%), and NO released (77.06%), accompanied by a reduced redox state as observed by increased GSH/GSSG ratio (to 198.80%). Also, the number of blood vessels within the wound granulation tissue seems to reduce in animals drinking Suppl SB (23.08%). Interestingly, SB and primarily Suppl SB showed a tendency to increase adipocyte number (to 194.26% and 156.68%, respectively) and reduce adipocyte size (4.60% and 24.64%, respectively) within the granuloma. Liver function and metabolism did not change among the animal groups as analyzed by plasma biochemical parameters, indicating no beverage toxicity. This study shows that XN intake in its natural beer context reduced inflammation, oxidative stress, and angiogenesis, ameliorating the wound healing process, suggesting that this polyphenol may exert beneficial effect as a nutritional supplement. J. Cell. Biochem. 113: 100–109, 2012. © 2011 Wiley Periodicals, Inc.
Broader utilization of origins of DNA replication in cancer cell lines along a 78 kb region of human chromosome 2q34
Authors: Valenzuela Manuel S. , Hu Lan , Lueders John , Walker Robert , Meltzer Paul S. 
Published: August 2011

AbstractHuman DNA replication depends on the activation of thousands of origins distributed within the genome. The actual distribution of origins is not known, nor whether this distribution is unique to a cell type, or if it changes with the proliferative state of the cell. In this study, we have employed a real‐time PCR‐based nascent strand DNA abundance assay, to determine the location of origins along a 78 kb region on Chr2q34. Preliminary studies using nascent DNA strands isolated from either HeLa and normal skin fibroblast cells showed that in both cell lines peaks of high origin activity mapped in similar locations. However, the overall origin profile in HeLa cells corresponded to broad origin activation zones, whereas in fibroblasts a more punctuated profile of origin activation was observed. To investigate the relevance of this differential origin profile, we compared the origin distribution profiles in breast cancer cell lines MDA‐MB‐231, BT‐474, and MCF‐7, to their normal counterpart MCF‐10A. In addition, the CRL7250 cell line was also used as a normal control. Our results validated our earlier observation and showed that the origin profile in normal cell lines exhibited a punctuated pattern, in contrast to broader zone profiles observed in the cancer cell lines. A quantitative analysis of origin peaks revealed that the number of activated origins in cancer cells is statistically larger than that obtained in normal cells, suggesting that the flexibility of origin usage is significantly increased in cancer cells compared to their normal counterparts. J. Cell. Biochem. 113: 132–140, 2012. © 2011 Wiley Periodicals, Inc.
Differential effect of CCL2 on constitutive neutrophil apoptosis between normal and asthmatic subjects
Authors: Yang Eun Ju , Choi Eugene , Ko Jesang , Kim Dong‐Hee , Lee Ji‐Sook , Kim In Sik 
Published: August 2011

AbstractIn this study, we investigated the effects of CCL2 on constitutive apoptosis of normal and asthmatic neutrophils. CCL2 blocked the constitutive apoptosis of normal neutrophils through CCR2. CCL2 also induced elevation of the cytosolic Ca2+ concentration but had no effect on normal neutrophil chemotaxis. Constitutive apoptosis, calcium influx, and cell migration of asthmatic neutrophils were not affected by CCL2 stimulation. Supernatant collected from CCL2‐treated normal neutrophils inhibited the constitutive apoptosis of normal neutrophils. Anti‐apoptotic signaling mediated by CCL2 was found to be associated with the PI3K/Akt/ERK/NF‐κB cascade in normal neutrophils. Both the cleavage of procaspase 3 and procaspase 9 and the decrease of in Mcl‐1 expression were delayed by CCL2 stimulation. Inhibition of NF‐κB blocked constitutive apoptosis of neutrophils from asthmatic patients via inhibition of the cleavage of procaspase 3 and procaspase 9, in contrast to normal neutrophils. NF‐κB was involved in CCL2‐induced anti‐apoptotic signaling in normal neutrophils, whereas NF‐κB functioned as a basal pro‐apoptotic factor in asthmatic neutrophils. A better understanding of the difference in the regulation of neutrophil apoptosis due to CCL2 between normal individuals and asthmatics will enable elucidation of the role of CC chemokine in neutrophils and a framework for understanding the pathogenesis of asthma. J. Cell. Physiol. 227: 2567–2577, 2012. © 2011 Wiley Periodicals, Inc.
Mechanism of T‐oligo‐induced cell cycle arrest in Mia‐Paca pancreatic cancer cells
Authors: Rankin Andrew M. , Sarkar Sibaji , Faller Douglas V. 
Published: August 2011

AbstractDNA oligonucleotides with sequence homology to human telomeric DNA (T‐oligo) induce cell cycle arrest, followed by apoptosis, senescence, or autophagy in a human cancer cell type‐specific manner. T‐oligo has potential as a new therapeutic strategy in oncology because of its ability to target certain types of tumor cells while sparing normal ones. In the present study, we demonstrate the T‐oligo‐induced S‐phase cell cycle arrest in four pancreatic cancer cell lines. To further contribute to the mechanistic understanding of T‐oligo, we also identify cyclin dependent kinase 2 (cdk2) as a functional mediator in the T‐oligo‐induced cell cycle arrest of pancreatic cancer cells. Ectopic expression of a constitutively active cdk2 mutant abrogates T‐oligo‐induced cell cycle arrest in these tumor cells while knockdown of cdk2 expression alone recapitulates the T‐oligo effect. Finally, we demonstrate the dispensability of T‐oligo‐induced ATM/ATR‐mediated DNA damage response‐signaling pathways, which have long been considered functional in the T‐oligo signaling mechanism. J. Cell. Physiol. 227: 2586–2594, 2012. © 2011 Wiley Periodicals, Inc.
Ytterbium(III) triflate: An efficient and simple catalyst for isomerization of 2′‐hydroxychalcone and 2′‐aminochalcones in ionic liquid
Authors: Rao V. Kameswara , Rao M. Sudershan , Kumar Anil 
Published: August 2011

AbstractIsomerization of 2′‐hydroxychalcone and 2′‐aminochalcone have been investigated using ytterbium(III) trifluromethanesulfonate {Yb(OTf)3} (30 mol %) as Lewis acid catalyst in [bmim][BF4] ionic liquid. The effect of different metal triflates as Lewis acid, catalyst loading and reaction media was studied for this isomerization reaction. Advantages of the methodology include short reaction time, excellent yields, catalytic use of Lewis acid, and recovery and reuse of the catalyst. J. Heterocyclic Chem., (2011).
A facile and efficient addition reaction of nitrogen‐containing heterocyclic compounds with DMAD under neat conditions
Authors: Valizadeh Hassan , Shomali Ashkan , Gholipour Hamid 
Published: August 2011

AbstractA simple and efficient method was developed for the reaction of dimethyl acetylenedicarboxylate with benzothiazole, isoquinoline, quinoline, 3‐bromopyridine, pyridine, benzoxazole, benzimidazole, and 5,6‐dimethyl benzimidazole for the high‐yield synthesis of the related heterocyclic products (1, 2, 3, 4, 5, 6, 7, 8) in very short reaction time under neat procedure. The reaction of isoquinoline, 3‐bromopyridine, and pyridine afforded to diastereomeric mixtures of products 2, 4, and 5, respectively. However, only one isomer of products 1, 3, 6, 7, and 8 were identified from the reaction of benzothiazole, quinoline, benzoxazole, benzimidazole, and 5,6‐dimethyl benzimidazole, respectively. Benzotriazole afforded to product 9 under these conditions. For comparison, the reactions were examined in different reaction mediums and/or under microwave irradiation. J. Heterocyclic Chem., (2011).
Silole‐core phenylacetylene dendrimers and their application in detecting picric acid
Authors: Li Shanshan , Leng Taohua , Zhong Hanbin , Wang Chengyun , Shen Yongjia 
Published: August 2011

AbstractSilole‐core phenylacetylene dendrimers were designed and synthesized, among them, the model compound (n = 0) and the first generation of the dendrimer (n = 1) were obtained by the reaction of 2,5‐dibromosilole with corresponding terminal alkynes, the second generation of the dendrimers (n = 2) was synthesized from 2,5‐diiodosilole. These compounds indicated the absorptions of both phenylacetylene dendrons (250–350 nm) and silole core (400–500 nm). The first generation displayed efficient energy transfer from phenylacetylene dendrons to silole core, whose energy transfer efficiency was as high as 80%. These compounds were used as chemical sensors to probe explosive, for picric acid (PA), the Stern–Volmer constants of model compound and the first generation are 7120 and 5490M−1, respectively. J. Heterocyclic Chem., (2012).
Microwave‐assisted synthesis of 1,3′‐diaza‐flavanone/flavone and their alkyl derivatives with antimicrobial activity
Authors: Kahriman Nuran , Iskender Nagihan Yilmaz , Yücel Murat , Yayli Nurettin , Demir Emine , Demirbağ Zihni 
Published: August 2011

AbstractA simple environmentally friendly solid‐phase microwave‐assisted method was used to synthesis of the 1,3′‐diazaflavanone (2) and 1,3′‐diazaflavone (3) from the cyclization of 2′‐amino (E)‐3″‐azachalcone (1). Ten new N‐alkyl (C5–12,14,15)‐substituted 1,3′‐diazaflavanonium bromides (2a–j) were prepared from compound 2 with corresponding alkyl halides in acetonitrile under reflux. In addition, nine new N,N′‐dialkyl (C5–12,14)‐substituted 1,3′‐diazaflavonium bromides (3a–i) were also synthesized from compound 3 with corresponding alkyl halides using basic silica in acetonitrile. The antimicrobial activities of compounds 1–3, 2a–j, and 3a–i were tested against Gram‐positive (G+) (Bacillus subtilis, Staphylococcus epidermidis, Staphylococcus aureus, and Enterococcus faecalis) and Gram‐negative (G−) (Escherichia coli, Klebsiella pneumonia, Pseudomonas aeruginosa, Proteus vulgaris, Salmonella typhimirium, Yersinia pseudotuberculosis, and Enterobacter cloaceae) microorganisms. They showed good antimicrobial activity against the Gram‐positive bacteria tested with the minimal inhibitory concentration values less than 7.8 μg/mL in most cases. The optimum length of the alkyl chain for better and broader activity is situated in the range of 9–12 carbon atoms in the series of compounds 2a–j and five to six carbon atoms in the series of compounds 3a–i. The nonalkylated compounds 1–3 were not effective, as were the ones alkylated with five or six C alkyl groups (2a and 2b) and 8–13 C alkyl groups for N,N′‐dialkyl compounds (3c–3i). The antimicrobial activity increased as the length of the alkyl substitution increased from 8 to 12 carbons in compounds 2a–j. However, antimicrobial activity decreased as the length of the alkyl substitution increased from 7 to 13 carbons in compounds 3c–i. J. Heterocyclic Chem., (2012)
Evaluation of the keyhole technique applied to the proton resonance frequency method for magnetic resonance temperature imaging
Authors: Han YongHee , Mun ChiWoong 
Published: August 2011

AbstractPurpose:To evaluate the temporal and spatial resolution of magnetic resonance (MR) temperature imaging when using the proton resonance frequency (PRF) method combined with the keyhole technique.Materials and Methods:Tissue‐mimicking phantom and swine muscle tissue were microwave‐heated by a coaxial slot antenna. For the sake of MR hardware safety, MR images were sequentially acquired after heating the subjects using a spoiled gradient (SPGR) pulse sequence. Reference raw (k‐space) data were collected before heating the subjects. Keyhole temperature images were reconstructed from full k‐space data synthesized by combining the peripheral phase‐encoding part of the reference raw data and the center phase‐encoding keyhole part of the time sequential raw data. Each keyhole image was analyzed with thermal error, and the signal‐to‐noise ratio (SNR) was compared with the self‐reference (nonkeyhole) images according to the number of keyhole phase‐encoding (keyhole‐data size) portions.Results:In applied keyhole temperature images, smaller keyhole‐data sizes led to more temperature error increases, but the SNR did not decreased comparably. Additionally, keyhole images with a keyhole‐data size of <16 had significantly different temperatures compared with fully phase‐encoded self‐reference images (P < 0.05).Conclusion:The keyhole technique combined with the PRF method improves temporal resolution and SNR in the measurement of the temperature in the deeper parts of body in real time. J. Magn. Reson. Imaging 2011;. © 2011 Wiley Periodicals, Inc.
Contributions of root respiration to total soil respiration before and after frost in Populus euphratica forests
Authors: Zhao ZhiMin , Zhao ChengYi , Mu YiliHa , Yu Sheng , Li Jun 
Published: August 2011

AbstractTemporal changes in soil CO2‐efflux rate was measured by a canopy‐gap method in a Populus euphratica forest located at the both sides of Tarim River banks (W China). Soil CO2‐efflux rates in situ were correlated with key soil biotic (e.g., fungal, bacterial, and actinomycetes populations) and abiotic (e.g., soil moisture, temperature, pH, organic C) variables. Two kinds of measurement plots were selected: one under the crown of a living Populus euphratica tree and the other under a dead standing Populus euphratica tree. Diurnal variations in soil respiration in these plots were measured both before and after the occurrence of the first frost. Soil respiration of the dead standing Populus euphratica (Rd) was assumed to be a measure of heterotrophic respiration rate (Rh), and root respiration rate (Rr) was estimated as the difference between soil respiration under living (Rl) minus soil respiration under dead standing Populus euphratica. Daily variation of Rr contribution to the total soil respiration in Populus euphratica forests were analyzed before and after the frost. The contribution of root respiration to total soil respiration before and after frost varied from 22% to 45% (mean 30%) and from 38% to 50% (mean 45%), respectively. In addition, Rh was significantly correlated with soil temperature both before and after frost. In contrast, Rr was not significantly correlated with soil temperature. Change in Q10 of Rr was different from that of Rh from before the frost to after the frost. Variation of Q10 of Rr from before the frost to after the frost was larger than that of Q10 of Rh. Thus, the results indicate that different soil respiration models are needed for Rr and Rh because different factors control the two components of soil respiration.
Seismic stratigraphy records the deglacial history of Jakobshavn Isbræ, West Greenland
Authors: Hogan Kelly A. , Dix Justin K. , Lloyd Jerry M. , Long Antony J. , Cotterill Carol J. 
Published: August 2011

AbstractJakobshavn Isbræ is one of the largest ice streams in the Greenland Ice Sheet, presently draining c. 6.5% of the Inland Ice. Here we present high‐resolution Chirp and Sparker sub‐bottom profiles from a seismic survey conducted just outside of the Jakobshavn Isfjord, which provides detailed insight into the glacimarine sedimentary history of the Jakobshavn ice stream during the Holocene. We observe acoustically stratified and homogeneous sediments that drape an irregular substratum and were deposited between ∼10 and c. 7.6k cal a BP. The stratified lower units are interpreted as the product of ice‐proximal glacimarine sedimentation deposited rapidly when the grounded ice margin was located close to depositional basins on topographic highs. The upper acoustically homogenous units reflect suspension settling of fine‐grained material and gravitational flows that were extruded from an increasingly unstable ice margin as the ice retreated into the fjord. Proximity to the ice margin and bedrock topography were the dominant controls on sediment accumulation during deglaciation although the 8.2‐ka cooling event probably influenced the position of the ice margin at the fjord mouth. The post‐glacial sedimentary record is characterized by glacimarine and hemipelagic rainout with an increased ice‐rafted detritus fraction that records sedimentation following ice stream retreat into Jakobshavn Isfjord sometime after c. 7.8k cal a BP. Copyright © 2011 John Wiley & Sons, Ltd.
An integrated enzyme‐linked immunosorbent assay system with an organic light‐emitting diode and a charge‐coupled device for fluorescence detection
Authors: Nakajima Hizuru , Okuma Yukiko , Morioka Kazuhiro , Miyake Mayo , Hemmi Akihide , Tobita Tatsuya , Yahiro Masayuki , Yokoyama Daisuke , Adachi Chihaya , Soh Nobuaki , Nakano Koji , Xue Shuhua , Zeng Hulie , Uchiyama Katsumi , Imato Toshihiko 
Published: August 2011

AbstractA fluorescence detection system for a microfluidic device using an organic light‐emitting diode (OLED) as the excitation light source and a charge‐coupled device (CCD) as the photo detector was developed. The OLED was fabricated on a glass plate by photolithography and a vacuum deposition technique. The OLED produced a green luminescence with a peak emission at 512 nm and a half bandwidth of 55 nm. The maximum external quantum efficiency of the OLED was 7.2%. The emission intensity of the OLED at 10 mA/cm2 was 13 μW (1.7 mW/cm2). The fluorescence detection system consisted of the OLED device, two band‐pass filters, a five microchannel poly(dimethylsiloxane) (PDMS) microfluidic device and a linear CCD. The fluorescence detection system was successfully used in a flow‐based enzyme‐linked immunosorbent assay on a PDMS microfluidic device for the rapid determination of immunoglobulin A (IgA), a marker for human stress. The detection limit (S/N=3) for IgA was 16.5 ng/mL, and the sensitivity was sufficient for evaluating stress. Compared with the conventional 96‐well microtiter plate assay, the analysis time and the amounts of reagent and sample solutions could all be reduced.
Preparation and evaluation of molecularly imprinted microspheres for solid‐phase extraction of 1,4‐hydroxybenzoic acid esters in soy
Authors: He Juan , Shen Yanzheng , Chen Si , Wei Hongliang , Zhu Jing , You Liqin , Lu Kui 
Published: August 2011

AbstractMolecularly imprinted microspheres (MIMs) were prepared by precipitation polymerization for the binding and recognition of 1,4‐hydroxybenzoic acid esters. Ethyl p‐hydroxybenzoate (EtPHB) was used as the template molecule, methacrylic acid as the functional monomer, ethylene dimethacrylate as the linking agent. It was evaluated by solid‐phase extraction column packed with MIMs combined with liquid chromatography to determine trace preservatives including benzoic acid, methyl p‐hydroxybenzoate, EtPHB, propyl p‐hydroxybenzoate in food products. A solid‐phase extraction based on MIM procedure was used to isolate four additives from the food matrix before quantitative analysis. The Scatchard plot suggested that the template–polymer system had two‐site binding behavior with the dissociation constants of 0.3577 and 3.952 mg/g, respectively. The rebinding test, based on the molecularly imprinted solid‐phase extraction column technique, showed the recoveries of soy samples spiked with four additives within 88.4–110.6%, with the relative standard deviations of 1.97–3.82%. Finally, the method was successfully applied for the analysis of parabens in foodstuff without traditional pretreatment.
Molecular dynamics simulation of intrusion of a C60 molecule ball into sliding contact space
Authors: Li Pei , Diao Dongfeng 
Published: August 2011

ABSTRACTThe intrusion process of a C60 ball into a sliding contact space with an included angle made up by two silicon substrates (100) was simulated using the molecular dynamics approach. The simulation was carried out using Tersoff potential of C and Si atoms at room temperature of 300 K. The included angle was defined as initial entry angle changing from 20° to 90° in the simulation for studying the effect of the initial entry angle during the intrusion process. The dependence of the initial entry angle on the number of sticking Si atoms of upper substrate was calculated. The results showed that the number of sticking atoms increased with the increasing of initial entry angle, and the number of sticking atoms was divided into three regions with different slopes, which could be used to evaluate the intrusion performance of a C60 ball into the sliding contact space. Copyright © 2011 John Wiley & Sons, Ltd.