bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mechanical properties of biodegradable small‐diameter chitosan artificial vascular prosthesis
Authors: Kong Xiaoying , Han Baoqin , Wang Haixia , Li Hui , Xu Wenhua , Liu Wanshun 
Published: April 2012

AbstractInitial clinical feasibility with the small‐diameter chitosan artificial vascular prosthesis has been reported previously. Here, we present the results of mechanical properties of artificial vascular prosthesis with 2, 3, and 4 mm inner diameter (ID) and compare some of the properties with the native blood vessel of dog femoral artery. Thickness wall measurement demonstrated the average wall thickness of the artificial vascular prosthesis with 2, 3, and 4 mm ID and the native blood vessel of the dog femoral artery with 3 mm ID were 0.54 ± 0.022 mm, 0.71 ± 0.032 mm, 0.79 ± 0.026 mm, and 0.67 ± 0.22 mm (n = 20). Water absorption rate of 226.02% ± 8.17%, 216.13% ± 4.86%, and 205.69% ± 4.34% were obtained from 2‐, 3‐, and 4‐mm‐diameter artificial vascular prosthesis (n = 12), respectively. Water osmotic pressure of the 2‐, 3‐, and 4‐mm‐diameter artificial vascular prosthesis was 39.25 ± 3.35 mmHg, 34.2 ± 4.54 mmHg, and 28.00 ± 2.72 mmHg (n = 20), respectively. Water osmotic amount of the 2‐, 3‐, and 4‐cm‐diameter artificial vascular prosthesis (n = 20) was 4.90 ± 0.47 mL/(min cm2), 5.51 ± 0.21 mL/(min cm2), and 6.24 ± 0.71 mL/(min cm2), respectively. The ruptured stretching rate of the artificial vascular prosthesis (n = 20) with 2, 3, and 4 mm ID and the native blood vessel was 1.59% ± 0.14%, 1.99% ± 0.24%, 2.52% ± 0.21%, and 32.16% ± 2.15%, respectively. The longitudinal tensile strength of the artificial vascular prosthesis (n = 20) with 2, 3, and 4 mm ID and the native blood vessel was 8.58 ± 1.98 N, 19.75 ± 4.07 N, 22.92 ± 3.85 N, and 18.76 ± 2.05 N, respectively. The suture retention of the artificial vascular prosthesis (n = 20) with 2, 3, and 4 mm ID and the native blood vessel in dry condition is 5.80 ± 0.51 N, 7.01 ± 0.32 N, 8.49 ± 0.56 N, and 7.92 ± 0.39 N, respectively. The suture retention of the artificial vascular prosthesis (n = 20) with 2, 3, and 4 mm ID in wet condition is 3.87 ± 0.43 N, 4.73 ± 0.37 N, 5.63 ± 0.36 N, and 7.92 ± 0.39 N, respectively. The compliance of the artificial vascular prosthesis with 2, 3, and 4 mm ID and the native blood vessel was 6.5% ± 2.6%/100 mmHg, 5.2% ± 1.5%/100 mmHg, 4.7% ± 1.3%/100 mmHg, and 10.3% ± 2.3%/100 mmHg, respectively. The data reported here fulfill the quality requirement of clinical use of this kind of biodegradable small diameter artificial vascular prosthesis. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A 2012.
The potential of electron beam radiation for simultaneous surface modification and bioresorption control of PLLA
Authors: Cairns Marie‐Louise , Dickson Glenn R. , Orr John F. , Farrar David , Hardacre Christopher , Sa Jacinto , Lemoine Patrick , Mughal Muhammad Zeeshan , Buchanan Fraser J. 
Published: April 2012

AbstractBioresorbable polymers have been widely investigated as materials exhibiting significant potential for successful application in the fields of tissue engineering and drug delivery. Further to the ability to control degradation, surface engineering of polymers has been highlighted as a key method central to their development. Previous work has demonstrated the ability of electron beam (e‐beam) technology to control the degradation profiles and bioresorption of a number of commercially relevant bioresorbable polymers (poly‐l‐lactic acid (PLLA), L‐lactide/DL‐lactide co‐polymer (PLDL) and poly(lactic‐co‐glycolic acid (PLGA)). This work investigates the further potential of e‐beam technology to impart added biofunctionality through the manipulation of polymer (PLLA) surface properties. PLLA samples were subjected to e‐beam treatments in air, with varying beam energies and doses. Surface characterization was then performed using contact angle analysis, X‐ray photoelectron spectroscopy (XPS), Raman spectroscopy, and atomic force microscopy. Results demonstrated a significant increase in surface wettability post e‐beam treatment. In correlation with this, XPS data showed the introduction of oxygen‐containing functional groups to the surface of PLLA. Raman spectroscopy indicated chain scission in the near surface region of PLLA (as predicted). However, e‐beam effects on surface properties were not shown to be dependent on beam energy or dose. E‐beam irradiation did not seem to affect the surface roughness of PLLA as a direct consequence of the treatment. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 100A: 2223–2229, 2012.
Compromised trabecular microarchitecture and lower finite element estimates of radius and tibia bone strength in adults with turner syndrome: A cross-sectional study using high-resolution–pQCT
Authors: Hansen Stinus , Brixen Kim , Gravholt Claus H 
Published: April 2012

Abstract
Although bone mass appear ample for bone size in Turner syndrome (TS), epidemiological studies have reported an increased risk of fracture in TS. We used high-resolution peripheral quantitative computed tomography (HR-pQCT) to measure standard morphological parameters of bone geometry and microarchitecture, as well as estimated bone strength by finite element analysis (FEA) to assess bone characteristics beyond bone mineral density (BMD) that possibly contribute to the increased risk of fracture. Thirty-two TS patients (median age 35, range 20–61 years) and 32 healthy control subjects (median age 36, range 19–58 years) matched with the TS participants with respect to age and body-mass index were studied. A full region of interest (ROI) image analysis and a height-matched ROI analysis adjusting for differences in body height between groups were performed. Mean bone cross-sectional area was lower in TS patients in radius (−15%) and tibia (−13%) (both p &lt; 0.01) whereas cortical thickness was higher in TS patients in radius (18%, p &lt; 0.01) but not in tibia compared to controls. Cortical porosity was lower in TS patients at both sites (−32% in radius, −36% in tibia, both p &lt; 0.0001). Trabecular integrity was compromised in TS patients with lower bone volume per tissue volume (BV/TV) (−27% in radius, −22% in tibia, both p &lt; 0.0001), trabecular number (−27% in radius, −12% in tibia, both p &lt; 0.05), and higher trabecular spacing (54% in radius, 23% in tibia, both p &lt; 0.01). In the height-matched ROI analysis, differences remained significant apart from total area at both sites, cortical thickness in radius, and trabecular number in tibia. FEA estimated failure load was lower in TS patients in both radius (−11%) and tibia (−16%) (both p &lt; 0.01) and remained significantly lower in the height-matched ROI analysis. Conclusively, TS patients had compromised trabecular microarchitecture and lower bone strength at both skeletal sites, which may partly account for the increased risk of fracture observed in these patients. © 2012 American Society for Bone and Mineral Research.
Osteoblast maturation and new bone formation in response to titanium implant surface features are reduced with age
Authors: Olivares-Navarrete Rene , Raines Andrew L , Hyzy Sharon L , Park Jung Hwa , Hutton Daphne L , Cochran David L , Boyan Barbara D , Schwartz Zvi 
Published: April 2012

Abstract
The surface properties of materials contribute to host cellular response and play a significant role in determining the overall success or failure of an implanted biomaterial. Rough titanium (Ti) surface microtopography and high surface free energy have been shown to enhance osteoblast maturation in vitro and increase bone formation in vivo. Whereas the surface properties of Ti are known to affect osteoblast response, host bone quality also plays a significant role in determining successful osseointegration. One factor affecting host bone quality is patient age. We examined both in vitro and in vivo whether response to Ti surface features was affected by animal age. Calvarial osteoblasts isolated from 1-, 3-, and 11-month-old rats all displayed a reduction in cell number and increases in alkaline phosphatase–specific activity and osteocalcin in response to increasing Ti surface microtopography and surface energy. Further, osteoblasts from the three ages examined displayed increased production of osteocalcin and local factors osteoprotegerin, vascular endothelial growth factor (VEGF)-A, and active transforming growth factor (TGF)-β1 in response to increasing Ti surface roughness and surface energy. Latent TGF-β1 only increased in cultures of osteoblasts from 1- and 3-month-old rats. Treatment with the systemic osteotropic hormone 1α,25(OH)2D3 further enhanced the response of osteoblasts to Ti surface features for all three age groups. However, osteoblasts derived from 11-month-old animals had a reduced response to 1α,25(OH)2D3 compared to osteoblasts derived from 1-or 3-month-old animals. These results were confirmed in vivo. Ti implants placed in the femoral intramedullary canal of old (9-month-old) mice yielded lower bone-to-implant contact and neovascularization in response to Ti surface roughness and energy compared to younger (2-month-old) mice. These results show that rodent osteoblast maturation in vitro as well as new bone formation in vivo is reduced with age. Whether comparable age differences exist in humans needs to be determined. © 2012 American Society for Bone and Mineral Research.
Calcium/calmodulin-signaling supports TRPV4 activation in osteoclasts and regulates bone mass
Authors: Masuyama Ritsuko , Mizuno Atsuko , Komori Hisato , Kajiya Hiroshi , Uekawa Atsushi , Kitaura Hideki , Okabe Koji , Ohyama Kaname , Komori Toshihisa 
Published: April 2012

Abstract
Osteoclast differentiation is critically dependent on calcium (Ca2+) signaling. Transient receptor potential vanilloid 4 (TRPV4), mediates Ca2+ influx in the late stage of osteoclast differentiation and thereby regulates Ca2+ signaling. However, the system-modifying effect of TRPV4 activity remains to be determined. To elucidate the mechanisms underlying TRPV4 activation based on osteoclast differentiation, TRPV4 gain-of-function mutants were generated by the amino acid substitutions R616Q and V620I in TRPV4 and were introduced into osteoclast lineage in Trpv4 null mice to generate Trpv4R616Q/V620I transgenic mice. As expected, TRPV4 activation in osteoclasts increased the number of osteoclasts and their resorption activity, thereby resulting in bone loss. During in vitro analysis, Trpv4R616Q/V620I osteoclasts showed activated Ca2+/calmodulin signaling compared with osteoclasts lacking Trpv4. In addition, studies of Trpv4R616Q/V620I mice that lacked the calmodulin-binding domain indicated that bone loss due to TRPV4 activation was abrogated by loss of interactions between Ca2+/calmodulin signaling and TRPV4. Finally, modulators of TRPV4 interactions with the calmodulin-binding domain were investigated by proteomic analysis. Interestingly, nonmuscle myosin IIa was identified by liquid chromatography–tandem mass spectroscopy (LC-MS/MS) analysis, which was confirmed by immunoblotting following coimmunoprecipitation with TRPV4. Furthermore, myosin IIa gene silencing significantly reduced TRPV4 activation concomitant with impaired osteoclast maturation. These results indicate that TRPV4 activation reciprocally regulates Ca2+/calmodulin signaling, which involves an association of TRPV4 with myosin IIa, and promotes sufficient osteoclast function. © 2012 American Society for Bone and Mineral Research.
Habitual levels of high, but not moderate or low, impact activity are positively related to hip BMD and geometry: Results from a population-based study of adolescents
Authors: Deere Kevin , Sayers Adrian , Rittweger Jörn , Tobias Jon H 
Published: April 2012

Abstract
Whether a certain level of impact needs to be exceeded for physical activity (PA) to benefit bone accrual is currently unclear. To examine this question, we performed a cross-sectional analysis between PA and hip BMD in 724 adolescents (292 boys, mean 17.7 years) from the Avon Longitudinal Study of Parents and Children (ALSPAC), partitioning outputs from a Newtest accelerometer into six different impact bands. Counts within 2.1 to 3.1g, 3.1 to 4.2g, 4.2 to 5.1g, and &gt;5.1g bands were positively related to femoral neck (FN) BMD, in boys and girls combined, in our minimally adjusted model including age, height, and sex (0.5–1.1g: beta = −0.007, p = 0.8; 1.1–2.1g: beta = 0.003, p = 0.9; 2.1–3.1g: beta = 0.042, p = 0.08; 3.1–4.2g: beta = 0.058, p = 0.009; 4.2–5.1g: beta = 0.070, p = 0.001; &gt;5.1g: beta = 0.080, p &lt; 0.001) (beta = SD change per doubling in activity). Similar positive relationships were observed between high-impact bands and BMD at other hip sites (ward's triangle, total hip), hip structure indices derived by hip structural analysis of dual-energy X-ray absorptiometry (DXA) scans (FN width, cross-sectional area, cortical thickness), and predicted strength (cross-sectional moment of inertia). In analyses where adjacent bands were combined and then adjusted for other impacts, high impacts (&gt;4.2g) were positively related to FN BMD, whereas, if anything, moderate (2.1–4.2g) and low impacts (0.5–2.1g) were inversely related (low: beta = −0.052, p = 0.2; medium: beta = −0.058, p = 0.2; high: beta = 0.137, p &lt; 0.001). Though slightly attenuated, the positive association between PA and FN BMD, confined to high impacts, was still observed after adjustment for fat mass, lean mass, and socioeconomic position (high: beta = 0.096, p = 0.016). These results suggest that PA associated with impacts &gt;4.2g, such as jumping and running (which further studies suggested requires speeds &gt;10 km/h) is positively related to hip BMD and structure in adolescents, whereas moderate impact activity (eg, jogging) is of little benefit. Hence, PA may only strengthen lower limb bones in adolescents, and possibly adults, if this comprises high-impact activity. © 2012 American Society for Bone and Mineral Research.
Microtomographic evaluation of the bone–cell interactions with a silorane‐based composite
Authors: Wu Xiaohong , Deng Feng , Wang Lu , Watts David C. 
Published: April 2012

AbstractThe low‐shrink Silorane‐based composite could bond effectively to bone and showed the potential be used as a bone cement. Bone organ culture maintains the anatomical order, natural cell‐to‐cell and cell‐to‐matrix relationship. The purpose of this study was to evaluate the responses of bone cells to a Silorane‐based composite which was compared with a representative polymethyl methacrylate (PMMA) bone cement. The critical size defects were created through the parietal bones from one litter of mice. The paired bones were divided into two groups: Silorane‐based composite group and PMMA group. The prepared two groups of disks were put into the defects. The cultures were grown in vitro for 38 days and analyzed with microcomputed‐tomography, dissecting‐microscope, phase‐ contrast‐microscope, scanning‐electron‐microscopy, and energy‐ dispersive‐X‐ray. At the 10th day, the Silorane disk was almost fully covered by a sheet of cells but the cells hardly attached to the disk surface. The edge of the PMMA disk was covered by a sheet of cells and the migrated individual cells attached to the whole surface of the disk. At the 38th day, some cells attached to the exposed disk area of the Silorane disk while the formed tissues covered the whole surface of the PMMA disk. The collagen fibers, globular deposits and bone formation were visible in both groups. The Silorane‐based composite showed promise as a potential bone cement when compared with PMMA which is used in clinical orthopedics. However, the cell attachment to PMMA was evidently better than to Silorane‐based composite. Microsc. Res. Tech. 75:1176–1184, 2012. © 2012 Wiley Periodicals, Inc.
Duck nest success adjacent to predator‐reduced sites
Authors: Pieron Matthew R. , Darr Margaret J. K. , Rohwer Frank C. 
Published: April 2012

AbstractPredator reduction regularly improves waterfowl nest success within management units, but the impact of predator reduction on nest success adjacent to trapped areas is not known. Trapping could reduce predator activity and increase nest success adjacent to trapped sites, as individual mammalian predators with home ranges largely outside the trapped area may still be killed when using portions of their home range that overlap the trapped area. We monitored 1,952 nests adjacent to (within 0–4.8 km) 7 trapped sites (each 93.2 km2) in eastern North Dakota, USA during 2005–2006 and found that nest success adjacent to trapped sites, regardless of distance from trapping, was similar to nest success in nontrapped areas and less than nest success inside trapped areas. Managers should not assume any benefits to nest success beyond the borders of trapped sites. © 2012 The Wildlife Society.
Steryl ferulates, bioactive compounds in cereal grains
Authors: Mandak Eszter , Nyström Laura 
Published: April 2012

AbstractSteryl ferulates are minor bioactive phytochemicals present in various cereal grains and other seeds. They possess well‐established health promoting properties, such as antioxidant and cholesterol lowering activities. However, the health promoting potential of steryl ferulates extracted from different sources can vary depending on their characteristic sterol composition.
Extraction of phospholipids from structured dry chicken egg
Authors: Wang Hui , Yao Linxing , Wang Tong 
Published: April 2012

AbstractChicken egg contains a high level of phospholipids (PL) in the yolk. Recovering yolk total lipids and extracting egg PL with efficiency are important to the availability and utilization of these health‐promoting lipid products. In this study, we prepared two structured dry egg yolk materials and used two common solvents to extract and concentrate the PL. We found that drum‐dried flake‐like yolk is an ideal starting material for lipid extraction. Anhydrous ethanol can extract almost all the neutral lipids and PL. PL with purity over 90% can be prepared by cold acetone precipitation from the total lipids.
Effect of pH on the Micellar Morphology of Semicrystalline PCL‐b‐PEO Block Copolymers in Aqueous Solution
Authors: He Wei‐Na , Xu Jun‐Ting , Du Bin‐Yang , Fan Zhi‐Qiang , Sun Fang‐Li 
Published: April 2012

AbstractThe effect of pH on the micellar morphology of a semicrystalline poly(ϵ‐caprolactone)‐block‐poly(ethylene oxide) block copolymer (PCL66‐b‐PEO44) in aqueous solution is investigated. Spherical micelles are formed in neutral and acidic solutions. However, addition of alkali to the neutral micellar solution triggers a sphere‐to‐cylinder transformation of the micellar morphology. The micelles are stable in both neutral and acidic solutions, but the size of the micelles becomes gradually larger in the alkali solution. This phenomenon is interpreted in terms of the effect of pH value on the reduced tethering density of the corona in the semicrystalline micelles.
Separation of High‐Impact Polypropylene Using Interactive Liquid Chromatography
Authors: Macko Tibor , Ginzburg Anton , Remerie Klaas , Bruell Robert 
Published: April 2012

AbstractFractionation techniques such as temperature rising elution fractionation or crystallization analysis fractionation fail to fractionate the ethylene–propylene (EP) copolymers, which are a component of high‐impact polypropylene (hiPP), according to their chemical composition. High‐temperature high‐performance liquid chromatography separates blends of EP‐copolymers and polypropylene. The elution volume of the EP‐copolymers depends linearly on the average content of ethylene. The separation according to the chemical composition was hyphenated with size exclusion chromatography. In this way, the relationship between the distribution with regard to chemical composition and molar mass, that is, the full chemical heterogeneity of hiPP, was revealed for the first time.
Direct Insertion Mass Spectrometric Analysis of Thermal Degradation of Poly(2‐alkyl‐2‐oxazoline)
Authors: Atılkan Nurcan , Nur Yusuf , Hacaloglu Jale , Schlaad Helmut 
Published: April 2012

AbstractDirect pyrolysis mass spectrometry is applied to investigate the thermal behavior of poly(2‐isopropyl‐2‐oxazoline) (PIPOX, a thermoresponsive polymer) and poly[2‐(3‐butenyl)‐2‐oxazoline] (PBOX, a “clickable” polymer). It is found that the thermal degradation of PIPOX is started by a loss of side chains. At slightly higher temperatures the degradation of the polymer backbone occurs by random chain scission processes. In the case of PBOX, vinyl polymerization of the side chains produces chains with variable thermal stabilities. The number of repeating units of the polymer has almost no effect on the thermal behavior of PIPOX, but significantly affects both thermal stability and degradation product distribution of PBOX.
Identification of a putative glycosyltransferase responsible for the transfer of pseudaminic acid onto the polar flagellin of Aeromonas caviae Sch3N
Authors: Parker Jennifer L. , Day‐Williams Michaela J. , Tomas Juan M. , Stafford Graham P. , Shaw Jonathan G. 
Published: April 2012

AbstractMotility in Aeromonas caviae, in a liquid environment (in broth culture), is mediated by a single polar flagellum encoded by the fla genes. The polar flagellum filament of A. caviae is composed of two flagellin subunits, FlaA and FlaB, which undergo O‐linked glycosylation with six to eight pseudaminic acid glycans linked to serine and threonine residues in their central region. The flm genetic locus in A. caviae is required for flagellin glycosylation and the addition of pseudaminic acid (Pse) onto the lipopolysaccharide (LPS) O‐antigen. However, none of the flm genes appear to encode a candidate glycotransferase that might add the Pse moiety to FlaA/B. The motility‐associated factors (Maf proteins) are considered as candidate transferase enzymes, largely due to their conserved proximity to flagellar biosynthesis loci in a number of pathogens. Bioinformatic analysis performed in this study indicated that the genome of A. caviae encodes a single maf gene homologue (maf1). A maf mutant was generated and phenotypic analysis showed it is both nonmotile and lacks polar flagella. In contrast to flm mutants, it had no effect on the LPS O‐antigen pattern and has the ability to swarm. Analysis of flaA transcription by reverse transcriptase PCR (RT‐PCR) showed that its transcription was unaltered in the maf mutant while a His‐tagged version of the FlaA flagellin protein produced from a plasmid was detected in an unglycosylated intracellular form in the maf strain. Complementation of the maf strain in trans partially restored motility, but increased levels of glycosylated flagellin to above wild‐type levels. Overexpression of maf inhibited motility, indicating a dominant negative effect, possibly caused by high amounts of glycosylated flagellin inhibiting assembly of the flagellum. These data provide evidence that maf1, a pseudaminyl transferase, is responsible for glycosylation of flagellin and suggest that this event occurs prior to secretion through the flagellar Type III secretion system.
Nurses' treatment of tobacco dependence in hospitalized smokers in three states
Authors: Sarna Linda , Bialous Stella , Ong Michael , Wells Marjorie , Kotlerman Jenny 
Published: April 2012

AbstractHospital‐based nurses (N = 1,790) from three states reported their interventions to help patients quit smoking. Frequency of nurses' interventions in one low tobacco use state, California (n = 651), were compared to nurses' interventions in two high tobacco use states, Indiana (n = 720) and West Virginia (n = 419). Nurses in California were significantly more likely to Advise smokers to quit (OR 1.34, 95% CI [1.06, 1.69]) and Refer smokers to a Quitline (OR 2.82, 95% CI [1.36, 5.88]) compared with nurses in the high tobacco prevalence states. Other aspects of their interventions did not differ by state. Quitline referral was infrequent (16%) but was quadrupled if nurses arranged for smokers to quit (OR 4.07, 95% CI [3.11, 5.32]). © 2012 Wiley Periodicals, Inc. Res Nurs Health 35:250–264, 2012