bluuebunny/crossref_metadata_2025 huggingface dataset:
Inflammatory markers and the risk of hip fracture: The women's health initiative
Authors: Barbour Kamil E , Boudreau Robert , Danielson Michelle E , Youk Ada O , Wactawski-Wende Jean , Greep Nancy C , LaCroix Andrea Z , Jackson Rebecca D , Wallace Robert B , Bauer Douglas C , Allison Matthew A , Cauley Jane A
Published: January 2012

Cytokines play a major role in bone remodeling in vitro and in animal models, with evidence supporting the involvement of inflammatory markers in the pathogenesis of osteoporosis. However, less is known about the longitudinal association of inflammatory markers with hip fracture. We tested whether high receptor levels of proinflammatory cytokines are associated with an increased risk of hip fracture in older women. We used a nested case-control study design from the Women's Health Initiative Observational Study (WHI-OS) and selected 400 cases with physician-adjudicated incident hip fractures and 400 controls matched on age, race, and date of blood draw. Participants were chosen from 39,795 postmenopausal women without previous hip fractures, not using estrogens or other bone-active therapies. Incident hip fractures (median follow-up 7.1 years) were verified by review of radiographs and confirmed by blinded central adjudicators. Hip fractures with a pathological cause were excluded. In multivariable models, the risk of hip fracture for subjects with the highest levels of inflammatory markers (quartile 4) compared with those with lower levels (quartiles 1, 2, and 3) was 1.43 (95% confidence interval [CI], 0.98–2.07) for interleukin-6 (IL-6) soluble receptor (SR), 1.40 (95% CI, 0.97–2.03) for tumor necrosis factor (TNF) SR1, and 1.56 (95% CI, 1.09–2.22) for TNF SR2. In subjects with all three markers in the highest quartile, the risk ratio of fracture was 2.76 (95% CI, 1.22–6.25) in comparison with subjects with 0 or 1 elevated marker(s) (p trend = 0.018). Elevated levels of inflammatory markers for all three cytokine-soluble receptors were associated with an increased risk of hip fractures in older women. Future clinical trials should test whether interventions to decrease inflammatory marker levels reduces hip fractures. © 2012 American Society for Bone and Mineral Research.
Novel extraneural role of neurite outgrowth inhibitor A: Modulation of osteoclastogenesis via positive feedback regulation of nuclear factor of activated T cell cytoplasmic 1
Authors: Lee Youngkyun , Kim Hyung Joon , Park Cheol Kyu , Kim Woo-Shin , Lee Zang Hee , Kim Hong-Hee
Published: January 2012

Osteoclasts are bone-resorbing cells differentiated from macrophage/monocyte lineage precursors upon receptor activator of NF-κB ligand (RANKL) stimulation. In a proteomic approach to identify proteins involved in osteoclastogenesis, we observed a dramatic increase in the expression of neurite outgrowth inhibitor A (Nogo-A) upon RANKL stimulation of mouse bone marrow macrophages (BMMs) in a nuclear factor of activated T cell cytoplasmic 1 (NFATc1)-dependent manner. The knockdown of Nogo-A in BMMs significantly reduced RANKL-dependent osteoclast differentiation accompanied by diminished NFATc1 induction, suggesting that a positive feedback mechanism is involved. Conversely, Nogo-A overexpression in BMMs as well as in RAW264.7 macrophages greatly augmented osteoclastogenesis, with concomitant increase in the NFATc1 induction. Both the mitogen-activated protein kinase (MAPK) pathway and calcium oscillation, which are central to RANKL-dependent NFATc1 activation and induction, were enhanced by Nogo-A. Finally, Nogo-A knockdown in mouse calvariae prevented interleukin 1 (IL-1)-induced bone loss. These findings not only reveal an unprecedented extraneural role of Nogo-A in osteoclastogenesis but also suggest a novel drug target against bone-lytic diseases. © 2012 American Society for Bone and Mineral Research.
The protective effect of aminoguanidine on doxorubicin‐induced nephropathy in rats
Authors: Abo‐Salem Osama M.
Published: January 2012

Reactive oxygen species and cytokines have been implicated in the nephrotoxicity induced by doxorubicin. The goal of the present study was to determine protective effect of aminoguanidine on doxorubicin‐induced nephrotoxicity in rats. Different groups of male Wistar rats received doxorubicin (67.75 mg/kg/i.p./2 days), aminoguanidine alone and aminoguanidine (200 and 400 mg/kg/i.p./30 days) prior to doxorubicin, respectively. Doxorubicin significantly increased serum creatinine (505%), blood urea nitrogen (333%), nitric oxide (406%), and plasma tumor necrosis factor‐alpha (706%) as well as urinary albumin (452%) and N‐acetyl‐β‐d‐glucosaminidase (415%) compared to control. Moreover, renal glutathione (334%), superoxide dismutase (283%), and catalase (513%) were significantly reduced accompanied with elevation in renal malondialdehyde compared to control. Pretreatment with aminoguanidine mitigated such changes in all mentioned parameters. Histopathological changes showed that doxorubicin‐caused significant structural damages to kidneys that were reduced with aminoguanidine. Results indicate that reactive oxygen species and cytokines are involved in doxorubicin‐induced nephrotoxicity, which can be reduced by aminoguanidine. © 2012 Wiley Periodicals, Inc. J Biochem Mol Toxicol 26:1–9 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/jbt.20422
Asymmetric halo and symmetric Single‐Halo Dual‐Material Gate and Double‐Halo Dual‐Material Gate n‐MOSFETs characteristic parameter modeling
Authors: Sarkar Angsuman , De Swapnadip , Sarkar Chandan Kumar
Published: January 2012

This paper presents an analytical subthreshold surface potential model of novel structures called asymmetric pocket‐implanted Double‐Halo Dual‐Material Gate (DHDMG) and Single‐Halo Dual‐Material Gate (SHDMG) Metal Oxide Semiconductor Field Effect Transistor (MOSFET), which combines the advantages of both the channel engineering (halo) and the gate engineering techniques (dual‐material gate) to effectively suppress the short‐channel effects (SCEs). The model is derived using the pseudo‐2D analysis by applying the Gauss's law to an elementary rectangular box in the channel depletion region, considering the surface potential variation with the channel depletion layer depth. The asymmetric pocket‐implanted model takes into account the effective doping concentration of the two linear pocket profiles at the source and the drain ends. The inner fringing field capacitances are also considered in the model for accurate estimation of the subthreshold surface potential at the two ends of the MOSFET. The same model is used to find the characteristic parameters for dual‐material gate with single‐halo and double‐halo implantations. It is concluded that the DHDMG device structure exhibits better suppression of the SCEs and the threshold voltage roll‐off than a pocket‐implanted and SHDMG MOSFET after investigating the characteristics parameter improvement. In order to validate our model, the modeled expressions have been extensively compared with the simulated characteristics obtained from the 2D device simulator DESSIS. A nice agreement is achieved with a reasonable accuracy over a wide range of device parameter and bias condition. Copyright © 2012 John Wiley & Sons, Ltd.
Synovial fluid microanalysis allows early diagnosis of ceramic hip prosthesis damage
Authors: Stea Susanna , Traina Francesco , Beraudi Alina , Montesi Monica , Bordini Barbara , Squarzoni Stefano , Sudanese Alessandra , Toni Aldo
Published: January 2012

The first clinical sign of ceramic hip prosthesis failure is hip noise. We therefore investigated whether isolation, observation at scanning electron microscopy, and chemical identification with microanalysis of particles from synovial fluid of “noisy hip” could be predictive of ceramic damage. Firstly, the level of “physiological wear” of well functioning ceramic‐on‐ceramic hip prostheses was assessed with this method, then the test was validated as diagnostic method for liner fracture. Twelve asymptomatic patients were enrolled to demonstrate the first aim; 39 cases of noisy hip (GROUP 1), and 7 cases of pending failure not related to ceramic (GROUP 2) were enrolled for the second aim. The analysis of the synovial fluid of the 12 asymptomatic patients allowed to set the “physiological wear” threshold. The analysis of GROUP 1 hips demonstrated the presence of ceramic particles (2 physiological, 12 mild, and 25 strong). The analysis of GROUP 2 showed a physiological presence of ceramic particles in all cases. Revision surgery in GROUP 1 was performed in 16 hips out 25 with strong ceramic particle presence and 2 out of 12 with mild ceramic particle presence. Failure of the ceramic component was evident in all but one of these cases, while the integrity of components was demonstrated in all seven hips of GROUP 2. Synovial fluid microanalysis can be a useful surrogate in predicting ceramic failure particularly when a strong presence of ceramic particles is observed. On the contrary there is not enough evidence to predict ceramic failure in presence of mild positivity. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 30:1312–1320, 2012
High expression of CD73 as a poor prognostic biomarker in human colorectal cancer
Authors: Wu Xian‐Rui , He Xiao‐Sheng , Chen Yu‐Feng , Yuan Rui‐Xue , Zeng Yang , Lian Lei , Zou Yi‐Feng , Lan Nan , Wu Xiao‐Jian , Lan Ping
Published: January 2012

Background and Objectives

To investigate the expression dynamics of CD73 and its prognostic significance in human colorectal cancer (CRC).

Methods

CD73 expression dynamics were detected by Western blotting. Immunohistochemistry was used to examine the expression of CD73 in CRC tissues from two independent cohorts by tissue microarrays. The optimal cutpoint of CD73 expression was assessed by the X‐tile program.

Results

Western blotting analysis demonstrated that CD73 expression in CRC was significantly higher than in normal colorectal tissues. According to the X‐tile program, the cutpoint for high expression of CD73 in CRC was determined when CD73 expression index was more than 5.9. High expression of CD73 was observed in 44.8% and 50.4% of CRC in the training and validation cohorts, respectively. Overexpression of CD73 was significantly correlated with tumor differentiation, nodal status, American Joint Committee on Cancer stage. Patients with high expression of CD73 had a poorer overall survival rate compared with patients with low expression of CD73 in both cohorts. In multivariate Cox regression analysis, overexpression of CD73 was proven to be an independent prognostic biomarker for CRC.

Conclusions

High expression of CD73 can be an independent and useful biomarker for predicting the poor survival of patients with CRC. J. Surg. Oncol. 2012; 106:130–137. © 2012 Wiley Periodicals, Inc.
Tribology of fluorinated diamond‐like carbon coatings: first principles calculations and sliding experiments
Authors: Sen F. G. , Qi Y. , Alpas A. T.
Published: January 2012

Sliding contact experiments and first principles calculations were conducted to study tribological properties of aluminium and fluorinated diamond‐like carbon (F‐DLC) surfaces. Sliding tests between Al and an F‐DLC coating generated a low coefficient of friction (COF) of 0.09–0.14 and led to the formation of carbonaceous transfer layers containing AlF3 on the Al surfaces as determined by X‐ray photoelectron spectroscopy. An interface model that examined the interactions between Al (111) and F‐terminated diamond (111) surfaces revealed that F atoms would transfer to the Al surface in increasing quantities with an increase in the contact pressure and the F transfer would lead to the formation of a stable AlF3 compound at the Al surface. The generation of repulsive forces between two F‐passivated surfaces as a result of the F transfer to the Al surface was shown to be responsible for the low COF between Al and F‐DLC. Copyright © 2012 John Wiley & Sons, Ltd.
Synthesis of π‐Conjugated Polymers Containing Aminoquinoline‐Borafluorene Complexes in the Main‐Chain
Authors: Tokoro Yuichiro , Nagai Atsushi , Tanaka Kazuo , Chujo Yoshiki
Published: January 2012

The regulation of electron transfer between a conjugated polymer and ligands orthogonally connected to the main‐chain is reported. Poly(arylene‐ethynylene)s containing aminoquinoline‐borafluorene complexes in the main‐chain are synthesized in good yields by a Sonogashira–Hagihara coupling. Single crystal X‐ray analysis of a model compound has elucidated the complex's structure in which the aminoquinolate moiety and the borafluorene ring are connected directly and orthogonally. Moreover, the optical properties of the polymers are characterized by UV‐vis absorption and photoluminescence spectra. Perfluorinated alkyl chain‐containing polymers show strong emission, while hydrocarbon chain‐containing ones exhibit only a slight emission. DFT calculation suggests that an electron transfer from the excited main‐chain to the aminoquinolate ligand is suppressed because of the lowered LUMO level by introducing the electron withdrawing groups, resulting in the significant emission.
A Simple and Effective Approach to Vesicles and Large Compound Vesicles via Complexation of Amphiphilic Block Copolymer With Polyelectrolyte in Water
Authors: Salim Nisa V. , Hanley Tracey L. , Waddington Lynne , Hartley Patrick G. , Guo Qipeng
Published: January 2012

This work reports for the first time a simple and effective approach to trigger a spheres‐to‐ vesicles morphological transition from amphiphilic block copolymer/polyelectrolyte complexes in aqueous solution. Vesicles and large compound vesicles (LCVs) were prepared via complexation of polystyrene‐block‐poly(ethylene oxide) (PS‐b‐PEO) with poly(acrylic acid) (PAA) in water and directly visualized using cryo‐TEM. The complexation and morphological transitions were driven by the hydrogen bonding between the complementary binding sites on the PAA and PEO blocks of the block copolymer. The findings in this work suggest that complexation between amphiphilic block copolymer and polyelectrolyte is a viable approach to vesicles and LCVs in aqueous media.
Using frequency‐labeled exchange transfer to separate out conventional magnetization transfer effects from exchange transfer effects when detecting ParaCEST agents
Authors: Lin Chien‐Yuan , Yadav Nirbhay N. , Friedman Joshua I. , Ratnakar James , Sherry A. Dean , van Zijl Peter C. M.
Published: January 2012

Paramagnetic chemical exchange saturation transfer agents combine the benefits of a large chemical shift difference and a fast exchange rate for sensitive MRI detection. However, the in vivo detection of these agents is hampered by the need for high B1 fields to allow sufficiently fast saturation before exchange occurs, thus causing interference of large magnetization transfer effects from semisolid macromolecules. A recently developed approach named frequency‐labeled exchange transfer utilizes excitation pulses instead of saturation pulses for detecting the exchanging protons. Using solutions and gel phantoms containing the europium (III) complex of DOTA tetraglycinate (EuDOTA‐(gly)−4), it is shown that frequency‐labeled exchange transfer allows the separation of chemical exchange effects and magnetization transfer (MT) effects in the time domain, therefore allowing the study of the individual resonance of rapidly exchanging water molecules (kex >104 s−1) without interference from conventional broad‐band MT. Magn Reson Med, 2012. © 2012 Wiley Periodicals, Inc.
Comparison of wideband steady‐state free precession and T2‐weighted fast spin echo in spine disorder assessment at 1.5 and 3 T
Authors: Danagoulian Giovanna S. , Qin Lei , Nayak Krishna S. , Colen Rivka R. , Mukundan Srinivasan , Harris Mitchell B. , Jolesz Ferenc A. , Shankaranarayanan Ajit , Copen William A. , Schmidt Ehud J.
Published: January 2012

Wideband steady‐state free precession (WB‐SSFP) is a modification of balanced steady‐state free precession utilizing alternating repetition times to reduce susceptibility‐induced balanced steady‐state free precession limitations, allowing its use for high‐resolution myelographic‐contrast spinal imaging. Intertissue contrast and spatial resolution of complete‐spine‐coverage 3D WB‐SSFP were compared with those of 2D T2‐weighted fast spin echo, currently the standard for spine T2‐imaging. Six normal subjects were imaged at 1.5 and 3 T. The signal‐to‐noise ratio efficiency (SNR per unit‐time and unit‐volume) of several tissues was measured, along with four intertissue contrast‐to‐noise ratios; nerve‐ganglia:fat, intradural‐nerves:cerebrospinal fluid, nerve‐ganglia:muscle, and muscle:fat. Patients with degenerative and traumatic spine disorders were imaged at both MRI fields to demonstrate WB‐SSFP clinical advantages and disadvantages. At 3 T, WB‐SSFP provided spinal contrast‐to‐noise ratios 3.7–5.2 times that of fast spin echo. At 1.5 T, WB‐SSFP contrast‐to‐noise ratio was 3–3.5 times that of fast spin echo, excluding a 1.7 ratio for intradural‐nerves:cerebrospinal fluid. WB‐SSFP signal‐to‐noise ratio efficiency was also higher. Three‐dimensional WB‐SSFP disadvantages relative to 2D fast spin echo are reduced edema hyperintensity, reduced muscle signal, and higher motion sensitivity. WB‐SSFP's high resolution and contrast‐to‐noise ratio improved visualization of intradural nerve bundles, foraminal nerve roots, and extradural nerve bundles, improving detection of nerve compression in radiculopathy and spinal‐stenosis. WB‐SSFP's high resolution permitted reformatting into orthogonal planes, providing distinct advantages in gauging fine spine pathology. Magn Reson Med, 2012. © 2012 Wiley Periodicals, Inc.
Skeletal muscle 1H MRSI before and after prolonged exercise. I. muscle specific depletion of intramyocellular lipids
Authors: Vermathen Peter , Saillen Pierre , Boss Andreas , Zehnder Monica , Boesch Chris
Published: January 2012

Aim of the study was to determine distribution and depletion patterns of intramyocellular lipids (IMCL) in leg muscles before and after two types of standardized endurance exercise. 1H‐magnetic resonance spectroscopic imaging was performed (1) in the thigh of eight‐trained cyclists after exercising on an ergometer for 3 h at 52 ± 8% of maximal speed and (2) in the lower leg of eight‐trained runners after exercising on a treadmill for 3 h at 49 ± 3% of maximal workload. Pre‐exercise IMCL contents were reduced postexercise in 11 out of 13 investigated upper and lower leg muscles (P < 0.015 for all). A strong linear correlation with a slope of ∼0.5 between pre‐exercise IMCL content and IMCL depletion was found. IMCL depletion differed strongly between muscles. Absolute and also relative IMCL reduction was significantly higher in muscles with predominantly slow fibers compared to those with fast fibers. Creatine levels and fiber orientation were stable and unchanged after exercise, while trimethyl‐ammonium groups increased. This is presented in the accompanying paper. In conclusion, a systematic comparison of metabolic changes in cross sections of the upper and lower leg was performed. The results imply that pre‐exercise IMCL levels determine the degree of IMCL depletion after exercise. Magn Reson Med, 2012. © 2012 Wiley Periodicals, Inc.
Texture analysis of high resolution MRI allows discrimination between febrile and afebrile initial precipitating injury in mesial temporal sclerosis
Authors: Alegro Maryana de Carvalho , Silva Alexandre Valotta , Bando Silvia Yumi , Lopes Roseli de Deus , Martins de Castro Luiz Henrique , HungTsu Wen , Moreira‐Filho Carlos Alberto , Amaro Edson
Published: January 2012

A computational pipeline combining texture analysis and pattern classification algorithms was developed for investigating associations between high‐resolution MRI features and histological data. This methodology was tested in the study of dentate gyrus images of sclerotic hippocampi resected from refractory epilepsy patients. Images were acquired using a simple surface coil in a 3.0T MRI scanner. All specimens were subsequently submitted to histological semiquantitative evaluation. The computational pipeline was applied for classifying pixels according to: a) dentate gyrus histological parameters and b) patients' febrile or afebrile initial precipitating insult history. The pipeline results for febrile and afebrile patients achieved 70% classification accuracy, with 78% sensitivity and 80% specificity [area under the reader observer characteristics (ROC) curve: 0.89]. The analysis of the histological data alone was not sufficient to achieve significant power to separate febrile and afebrile groups. Interesting enough, the results from our approach did not show significant correlation with histological parameters (which per se were not enough to classify patient groups). These results showed the potential of adding computational texture analysis together with classification methods for detecting subtle MRI signal differences, a method sufficient to provide good clinical classification. A wide range of applications of this pipeline can also be used in other areas of medical imaging. Magn Reson Med, 2012. © 2012 Wiley Periodicals, Inc.
Simulations of high permittivity materials for 7 T neuroimaging and evaluation of a new barium titanate‐based dielectric
Authors: Teeuwisse W. M. , Brink W. M. , Haines K. N. , Webb A. G.
Published: January 2012

High permittivity “dielectric pads” have been shown to increase image quality at high magnetic fields in regions of low radiofrequency transmit efficiency. This article presents a series of electromagnetic simulations to determine the effects of pad size and geometry, relative permittivity value, as well as thickness on the transmit radiofrequency fields for neuroimaging at 7 T. For a 5‐mm thick pad, there is virtually no effect on the transmit field for relative permittivity values lower than ∼90. Significant improvements are found for values between 90 and ∼180. If the relative permittivity is increased above ∼180 then areas of very low transmit efficiency are produced. For a 1‐cm thick pad, the corresponding numbers are ∼60 and ∼120, respectively. Based upon the findings, a new material (barium titanate, relative permittivity ∼150) is used to produce thin (∼5 mm) dielectric pads which can easily be placed within a standard receive head array. Experimental measurements of transmit sensitivities, as well as acquisition of T2‐ and T‐weighted images show the promise of this approach. Magn Reson Med, 2012. © 2012 Wiley Periodicals, Inc.
Game‐based cross‐layer channel allocation with SVC‐encoded multimedia streams in cognitive radio networks
Authors: Wu Kuo‐Wei , Kuo Wen‐Kuang
Published: January 2012

The available unlicensed spectrum is increasingly being used by new wireless technologies, but past measurements show that the licensed spectrum is extremely underutilized. To address this issue, the IEEE 802.22 Working Group is developing a novel wireless air interface standard based on cognitive radios (CRs), i.e. IEEE 802.22 wireless regional area networks (WRANs). Moreover, over the last decade wireless multimedia applications have developed rapidly, raising significant concerns about the quality of service (QoS) of multimedia stream transmissions. In particular, the Joint Video Team (JVT) and ITU‐T Video Coding Experts Group (VCEG) jointly proposed Scalable Video Coding (SVC) as the next‐generation multimedia compression standard. However, the current IEEE 802.22 WRAN draft does not specify QoS mechanisms for SVC‐encoded multimedia stream transmission in CR networks. To resolve this problem, we developed a cross‐layer channel allocation algorithm (CLCAA) and a novel media access control (MAC) protocol to work with the algorithm. The CLCAA adapts to the characteristics of multimedia traffic and variations of wireless channels by determining the weighting of source–destination pair, which is determined by the deadlines of SVC‐encoded multimedia streams, the queuing delay and channel conditions. The CLCAA then allocates transmission opportunities to source–destination pairs based on their weightings and game theory. We also conducted extensive simulations to demonstrate the efficiency of the CLCAA scheme. The simulation results show that the CLCAA scheme not only guarantees QoS for multimedia traffic but also achieves fairness across different streams. Copyright © 2012 John Wiley & Sons, Ltd.
Bevacizumab and irinotecan in children with recurrent or refractory brain tumors: Toxicity and efficacy trends
Authors: Couec Marie‐Laure , André Nicolas , Thebaud Estelle , Minckes Odile , Rialland Xavier , Corradini Nadège , Aerts Isabelle , Bérard Perrine Marec , Bourdeaut Franck , Leblond Pierre ,   on the behalf of the Comité Pharmacologie of the SFCE
Published: January 2012

Background

Bevacizumab, a monoclonal antibody targeting the vascular endothelial growth factor, has proven efficacy in some adult tumors; it is now proposed as a new therapeutic strategy for refractory or recurrent brain tumors in some children, either alone or combinated.

Procedure

We retrospectively analyzed 28 children who received bevacizumab on a compassionate basis for refractory or recurrent brain tumors between June 2007 and August 2010 in 7 French centers. Among them, 12 had high‐grade gliomas, 7 low‐grade gliomas, 4 ependymomas, 2 primitive neurectodermal tumors, 3 neuroglial tumors. The median age at start of bevacizumab was 11.0 years. Bevacizumab was administered at 5–10 mg/kg every 2 weeks, with concomitant chemotherapy for 27 patients.

Results

Bevacizumab was used in combination with irinotecan in 27 patients. Bevacizumab‐related toxicity was mild. Toxicities reported were grade I–II hypertension (n = 4), proteinuria (n = 1), lymphopenia (n = 2), wound healing delay (n = 2). Whereas tumor reduction could be observed in 6:7 patients with low‐grade gliomas, no efficacy could be documented in patients with high‐grade glioma, nor PNET nor ependymoma.

Conclusion

Bevacizumab‐related acute toxicity appears to be low in children, even in combination with irinotecan. Further prospective trials are required to confirm the hypothetical efficacy of bevacizumab and to assess the risk of long‐term toxicity especially in the youngest children. Pediatr Blood Cancer 2012; 59: 34–38. © 2012 Wiley Periodicals, Inc.
3D strings and other anyonic things
Authors: Mezincescu L. , Townsend P.K.
Published: January 2012

We explain how fractional spin and statistics are relevant to (super)strings in a three‐dimensional (3D) Minkowski spacetime.
Functional and structural characterization of a thermostable acetyl esterase from Thermotoga maritima
Authors: Levisson Mark , Han Gye Won , Deller Marc C. , Xu Qingping , Biely Peter , Hendriks Sjon , Ten Eyck Lynn F. , Flensburg Claus , Roversi Pietro , Miller Mitchell D. , McMullan Daniel , von Delft Frank , Kreusch Andreas , Deacon Ashley M. , van der Oost John , Lesley Scott A. , Elsliger Marc‐André , Kengen Servé W. M. , Wilson Ian A.
Published: January 2012

TM0077 from Thermotoga maritima is a member of the carbohydrate esterase family 7 and is active on a variety of acetylated compounds, including cephalosporin C. TM0077 esterase activity is confined to short‐chain acyl esters (C2–C3), and is optimal around 100°C and pH 7.5. The positional specificity of TM0077 was investigated using 4‐nitrophenyl‐β‐D‐xylopyranoside monoacetates as substrates in a β‐xylosidase‐coupled assay. TM0077 hydrolyzes acetate at positions 2, 3, and 4 with equal efficiency. No activity was detected on xylan or acetylated xylan, which implies that TM0077 is an acetyl esterase and not an acetyl xylan esterase as currently annotated. Selenomethionine‐substituted and native structures of TM0077 were determined at 2.1 and 2.5 Å resolution, respectively, revealing a classic α/β‐hydrolase fold. TM0077 assembles into a doughnut‐shaped hexamer with small tunnels on either side leading to an inner cavity, which contains the six catalytic centers. Structures of TM0077 with covalently bound phenylmethylsulfonyl fluoride and paraoxon were determined to 2.4 and 2.1 Å, respectively, and confirmed that both inhibitors bind covalently to the catalytic serine (Ser188). Upon binding of inhibitor, the catalytic serine adopts an altered conformation, as observed in other esterase and lipases, and supports a previously proposed catalytic mechanism in which Ser hydroxyl rotation prevents reversal of the reaction and allows access of a water molecule for completion of the reaction. Proteins 2012. © 2012 Wiley Periodicals, Inc.
Crystal structure and biochemical properties of putrescine carbamoyltransferase from Enterococcus faecalis: Assembly, active site, and allosteric regulation
Authors: Shi Dashuang , Yu Xiaolin , Zhao Gengxiang , Ho Jeremy , Lu Shennon , Allewell Norma M. , Tuchman Mendel
Published: January 2012

Putrescine carbamoyltransferase (PTCase) catalyzes the conversion of carbamoylputrescine to putrescine and carbamoyl phosphate (CP), a substrate of carbamate kinase (CK). The crystal structure of PTCase has been determined and refined at 3.2 Å resolution. The trimeric molecular structure of PTCase is similar to other carbamoyltransferases, including the catalytic subunit of aspartate carbamoyltransferase (ATCase) and ornithine carbamoyltransferase (OTCase). However, in contrast to other trimeric carbamoyltransferases, PTCase binds both CP and putrescine with Hill coefficients at saturating concentrations of the other substrate of 1.53 ± 0.03 and 1.80 ± 0.06, respectively. PTCase also has a unique structural feature: a long C‐terminal helix that interacts with the adjacent subunit to enhance intersubunit interactions in the molecular trimer. The C‐terminal helix appears to be essential for both formation of the functional trimer and catalytic activity, since truncated PTCase without the C‐terminal helix aggregates and has only 3% of native catalytic activity. The active sites of PTCase and OTCase are similar, with the exception of the 240′s loop. PTCase lacks the proline‐rich sequence found in knotted carbamoyltransferases and is unknotted. A Blast search of all available genomes indicates that 35 bacteria, most of which are Gram‐positive, have an agcB gene encoding PTCase located near the genes that encode agmatine deiminase and CK, consistent with the catabolic role of PTCase in the agmatine degradation pathway. Sequence comparisons indicate that the C‐terminal helix identified in this PTCase structure will be found in all other PTCases identified, suggesting that it is the signature feature of the PTCase family of enzymes Proteins 2012; © 2012 Wiley Periodicals, Inc.
Recognition between a short unstructured peptide and a partially folded fragment leads to the thioredoxin fold sharing native‐like dynamics
Authors: Binolfi Andrés , Fernández Claudio O. , Sica Mauricio P. , Delfino José M. , Santos Javier
Published: January 2012

Thioredoxins (TRXs) constitute attractive α/β scaffolds for investigating molecular recognition. The interaction between the recombinant fragment spanning the sequence 1–93 of full‐length TRX (TRX1‐93) and the synthetic peptide comprising residues 94–108 (TRX94‐108), plus a C‐terminal tyrosine tag (the numbering scheme used in entry pdb 2TRX is used throughout the article, two complementary moieties of E. coli TRX, brings about the consolidation of a native‐like complex. Despite its reduced thermodynamic stability, this complex is able to acquire fine structural features remarkably similar to those characteristic of full‐length TRX, namely, hydrodynamic behavior, assessed by diffusion‐ordered spectroscopy (DOSY)‐NMR; the pattern of secondary structure, as revealed by three‐bond HNHα coupling constants and secondary shifts for Hα/CO/Cα/Cβ; native‐like tertiary structural signatures revealed by near‐UV circular dichroism (CD) spectroscopy. The complex exhibits a relaxation behavior compatible with that expected for a native‐like structure. However, heteronuclear nuclear Overhauser effect (NOE)s reveal an enhanced dynamics for the complex by comparison with full‐length TRX. Furthermore, higher R2 values for residues 43–50 and 74–89 would likely result from an exchange process modulated by the peptide at the interface region. The slow kinetics of the consolidation reaction was followed by CD and real‐time NMR. Equilibrium titration experiments by NMR yield a KD value of 1.4 ± 1.0 μM and a second low‐affinity (>150 μM) binding event in the vicinity of the active site. Molecular dynamics simulations of both the isolated fragment TRX1‐93 and the complex suggest the destabilization of α2 and α3 helical elements and the persistence of β‐structure in the absence of TRX94‐108. Altogether, structural and dynamic evidence presented herein points to the key role played by the C‐terminal helix in establishing the overall fold. This critical switch module endows reduced TRX with the ability to act as a cooperative folding unit. Proteins 2012;. © 2012 Wiley Periodicals, Inc.
The Graphical Analysis for Maintenance Management Method: A Quantitative Graphical Analysis to Support Maintenance Management Decision Making
Authors: Martínez Luis Barberá , Márquez Adolfo Crespo , Gunckel Pablo Viveros , Andreani Adolfo Arata
Published: January 2012

This article proposes a logical support tool for maintenance management decision making. This tool is called the Graphical Analysis for Maintenance Management (GAMM), a method to visualize and analyze equipment dependability data in a graphical form. The method helps for a quick and clear analysis and interpretation of equipment maintenance (corrective and preventive) and operational stoppages. Then, opportunities can be identified to improve both operations and maintenance management (short–medium term) and potential investments (medium–long term). The method allows an easy visualization of parameters, such as the number of corrective actions between preventive maintenance, the accumulation of failures in short periods of time, and the duration of maintenance activities and sequence of stops of short duration. In addition, this tool allows identifying, a priori, anomalous behavior of equipment, whether derived from its own function, maintenance activities, misuse, or even equipment designs errors.

In this method, we used a nonparametric estimator of the reliability function as a basis for the analysis. This estimator takes into account equipment historical data (total or partial) and can provide valuable insights to the analyst even with few available data. Copyright © 2012 John Wiley & Sons, Ltd.
Hybrid Monitoring for the Prognostic of the Reliability System
Authors: Elmeliani Jalloul , Nabli Lotfi , Messaoud Hassani
Published: January 2012

This paper aims at developing a model for the monitoring of a rotating machine. The contribution in this model is the development of the last stage of monitoring which is the prognostic; indeed, the method used takes into account the required quality criteria of the product on one hand and the state of the current system of one somewhere else on the other. The objective of this contribution is to estimate the reliability of the system in time and to plan the time of total system dysfunction. The interval constrained Petri nets are used for the modeling of an industrial example which is the centrifuge pump. Copyright © 2012 John Wiley & Sons, Ltd.
Reliability Assessment of Metallized Film Capacitors using Reduced Degradation Test Sample
Authors: Sun Quan , Tang Yanzhen , Feng Jing , Jin Tongdan
Published: January 2012

Metallized film capacitor is a type of product with a long lifetime and high reliability. It is difficult to assess the lifetime and reliability using the traditional statistical inference method which is based on the large number of testing data. This paper presents a new testing methodology, called T‐performance degradation test, by dividing the test process into several stages. In each stage, the sample size of working capacitors under test decreases stage by stage until the test lasts enough time with few survival capacitors. Leveraging the T‐performance degradation data, this paper further presents a reliability assessment model to predict the lifetime of the high‐performance capacitors. Finally, the reliability assessment model is demonstrated on a type of high‐performance metallized film capacitors used in the energy module of the laser facility. Copyright © 2012 John Wiley & Sons, Ltd.
Making skeletal muscle from progenitor and stem cells: development versus regeneration
Authors: Fan Chen‐Ming , Li Lydia , Rozo Michelle E. , Lepper Christoph
Published: January 2012

For locomotion, vertebrate animals use the force generated by contractile skeletal muscles. These muscles form an actin/myosin‐based biomachinery that is attached to skeletal elements to affect body movement and maintain posture. The mechanics, physiology, and homeostasis of skeletal muscles in normal and disease states are of significant clinical interest. How muscles originate from progenitors during embryogenesis has attracted considerable attention from developmental biologists. How skeletal muscles regenerate and repair themselves after injury by the use of stem cells is an important process to maintain muscle homeostasis throughout lifetime. In recent years, much progress has been made toward uncovering the origins of myogenic progenitors and stem cells as well as the regulation of these cells during development and regeneration. WIREs Dev Biol 2012, 1:315–327. doi: 10.1002/wdev.30

This article is categorized under:

Signaling Pathways > Cell Fate Signaling

Vertebrate Organogenesis > Musculoskeletal and Vascular

Adult Stem Cells, Tissue Renewal, and Regeneration > Tissue Stem Cells and Niches

Adult Stem Cells, Tissue Renewal, and Regeneration > Regeneration
An approach to enrich users’ personomy using the recommendation of semantic tags
Authors: da Silva Sérgio R. P. , Borth Marcelo R. , Ferreira Josiane M. P. , Feltrim Valéria D.
Published: January 2012

Tagging-based systems are a popular and convenient way to organize information on the Web. Despite the alleged advantage of the free choice of words used to categorize Web resources in this kind of systems, it also brings some disadvantages due to the difficulty to remember freely chosen tags when users need to retrieve tagged resources. This paper presents a new approach to improve the quality of the categorizations performed by users in tagging-based systems by means of the recommendation of semantic tags. Our approach combines three sources of information for selecting the recommended tags: the Web resource been categorized, the tagging-based system folksonomy and the user personomy. By using these sources, we combine some features of the context of the categorization, the social opinion about the resource been categorized and the users’ vocabulary preferences. The use of the Web resource helps to solve the cold start problem, and the recommendation of more contextualized and personalized tags helps to develop a better personomy for the user, which could relieve the users’ cognitive effort when retrieving tagged resources.
Self‐Reported Issues With Driving in Patients With Chronic Pain
Authors: Fan Anita , Wilson Keith G. , Acharya Meena , Cranney Anne , Buenger Usha , Marshall Shawn
Published: January 2012

Objective

To assess the driving habits, driving patterns, and barriers to driving reported by patients with chronic pain.

Design

Cross‐sectional mail survey with self‐administered questionnaires.

Setting

University‐affiliated hospital.

Participants

A sample of 223 patients seen in consultation by a physiatrist through the Chronic Pain Rehabilitation Service.

Interventions

Not applicable.

Main Outcome Measurements

Percentage of subjects who were current drivers, percentage of subjects experiencing difficulty with driving, and driving characteristics.

Results

Response rate was 48.9%. Of the subjects, 79% were current drivers; of the nondrivers, 56% reported stopping driving because of chronic pain. A significantly greater percentage of nondrivers (80%) than drivers (62.9%) were women (P = .039). Nondrivers reported greater levels of pain than drivers (P = .027). The mean Pain Disability Index total score was significantly lower for drivers (42.3) than for nondrivers (48.7; P = .006). Of all subjects, 70% indicated that pain limited their driving in some manner; 41% of this group indicated that they experienced quite a bit or a great deal of difficulty driving. Factors that limited driving included pain (88.9%), fatigue (50.6%), limited joint mobility/stiffness (48.3%), and weakness (19.4%). The most frequently reported difficulties related to driving were sitting for any length of time (79.6%) and getting into the driver's seat (66.5%). Only 2.4% of current drivers had been referred for a driving assessment.

Conclusions

Most people with chronic pain continue to drive and overall appear to have better functioning than those who cannot continue driving because of chronic pain. Despite being able to drive, a significant proportion of drivers with chronic pain are facing challenges not only with driving the vehicle but also with entering and positioning themselves within the vehicle. Our results suggest that chronic pain does have an impact on driving. However, it appears to be generally unrecognized as a factor for driving other than when the implications of opioid use are considered.
SALAFI TRANSFORMATIONS: ADEN AND THE CHANGING VOICES OF RELIGIOUS REFORM IN THE INTERWAR INDIAN OCEAN
Authors: Reese Scott S.
Published: January 2012

The Islamic reformist movement known as Salafism is generally portrayed as a relentlessly literalist and rigid school of religious thought. This article pursues a more nuanced picture of a historical Salafism that is less a movement with a single, linear origin than a dynamic intellectual milieu continually shaped by local contexts. Using 1930s Aden as a case study, the article examines how a transregional reformist discourse could be vulnerable to local interpretation and begins to unpack the transformation of Salafi activism from a broad, doctrinaire, and, above all, foreign ideology to an integral part of local religious discourse. It situates reform within an evolving Islamic discursive tradition that in part developed as a result of its own theological logic but was equally shaped by local and historically contingent institutions, social practices, and power structures. It thus explores Salafism as a dynamic tradition that could be adapted by local intellectuals to engage the problems facing their own communities.
The “Arab Spring” as Seen through the Prism of the 1979 Iranian Revolution
Authors: Nabavi Negin
Published: January 2012

Revolutions are by nature unpredictable and unsettling. That the wave of revolutions in North Africa and the Arab Middle East began so unexpectedly and spread with such speed, leading to the fall of the governments of Tunisia, Egypt, and Libya, has added to the concern regarding the “new order” that is to come after the initial euphoria. From the outset, the fear has been that these revolutions will follow the same trajectory as Iran did in 1979—in other words, that they will marginalize those who launched the revolutions and provide the grounds for the rise to power of the most savvy, purposeful, and best organized of the opposition groups, namely, the Islamists. Yet when one considers the recent uprisings in the Arab world through the prism of Iran's experiences in 1979, the parallels are not so evident. Mindful of the variations and distinctions between each of the revolutions in Tunisia, Egypt, and Libya, it would appear that in broad terms, and beyond superficial similarities, there is little in common between the events of Iran in 1979 and what has happened in the past year in the Arab world.
Freedom Springs Eternal
Authors: Kashani-Sabet Firoozeh
Published: January 2012

Revolutions are chaotic affairs. In February 1979, when Ayatollah Khomeini and his followers declared victory, Iran's future seemed uncertain. After a long night of hostility and bloodshed, an eerie silence fell on Tehran, and in some corners fear supplanted exhilaration. Those of us who witnessed these historic events did not fully fathom what Islamic politics augured. Within weeks, on the occasion of International Women's Day, it became clear that women had become targets of the regime's cultural indoctrination. Other matters remained murky for months and would play out gradually in the first decade after the revolution.
A RESPONSE TO PEZHMANN DAILAMI'S REVIEW OF FROM QAJAR TO PAHLAVI: IRAN, 1919–1930
Authors: Majd Mohammad Gholi
Published: January 2012

In his review of From Qajar to Pahlavi: Iran, 1919–1930 (Lanham, Md.: University Press of America, 2008) published in the November 2010 issue of IJMES, Pezhmann Dailami denigrates my book for relying on U.S. State Department archives instead of the usual British records, and claims that “Majd's story has an obvious purpose, and that is to justify the deep sense of vulnerability and the violent anti-Western paranoia of the Iranian regime.” First, given that the available British records have been used extensively in other studies, I saw no point in reproducing them yet again. Second, American records have not been used before and provide a fresh perspective. My book uses nearly 800 new documents, one for every five days of the period covered; to call it an attempt “to justify” the policies of the Islamic Republic is absurd. Moreover, Dailami claims, “Evidence that the 1921 coup was a British design is largely circumstantial. Of course, Reza was Britain's perfect man. He could resist the advances of Soviet Russia while remaining friendly to the old imperial power.” But Dailami then contradicts himself in the next paragraph when he writes, “In any case, that Reza got rid of the last remnants of British political influence in Iran does not appear to matter to anyone. It must be admitted that he did so under Soviet pressure.”
Proliferative effect of whey from cows’ milk varying in phyto-oestrogens in human breast and prostate cancer cells
Authors: Nielsen Tina S. , Höjer Annika , Gustavsson Anne-Maj , Hansen-Møller Jens , Purup Stig
Published: January 2012

Intake of dietary phyto-oestrogens has received a great deal of attention owing to their potential influence on hormone-sensitive cancers such as breast and prostate cancer. Cows’ milk contains phyto-oestrogens and the content varies according to the composition of the feed and the type and amount of legumes used. In this study we evaluated the proliferative effect of milk (whey) with different phyto-oestrogen content in human breast (MCF-7) and prostate cancer cells (PC-3). Milk was obtained from cows fed either a birdsfoot trefoil-timothy silage based ration (B1) or two different red clover silage based diets (R1 and R2) resulting in total phyto-oestrogen contents of 403, 1659 and 1434 ng/ml for the B1, R1 and R2 diets, respectively. Whey was produced from the milk and added to cell culture medium in concentrations up to 10% for MCF-7 cells and 5% for PC-3 cells. Cell proliferation was measured fluorometrically after 7 d for MCF-7 cells and 5 d for PC-3 cells. There was no significant difference in the proliferative effect of whey from the different dietary treatments at any of the whey concentrations tested. An anti-proliferative effect (P<0·01) of 5 and 10% whey was seen when tested in the presence of 10 pmoestradiol in the medium. This effect was independent of dietary treatment of cows. Whey induced a significant (P<0·01) proliferative response in PC-3 cells independent of dietary treatment. Purified equol in concentrations similar to equol concentrations in milk decreased PC-3 cell proliferation, and therefore the stimulatory effect of whey in PC-3 cells is believed to be mediated by other bioactives than equol. In conclusion, our results suggest that using whey in these proliferation assays, it was not possible to discriminate between milk with high or low levels of phyto-oestrogens.