bluuebunny/crossref_metadata_2025_split huggingface dataset:
Humoral immune responses to Plasmodium falciparum among HIV‐1‐infected Kenyan adults
Authors: Nnedu Obinna N. , O'Leary Michael P. , Mutua Daniel , Mutai Beth , Kalantari‐Dehaghi Mina , Jasinskas Al , Nakajima‐Sasaki Rie , John‐Stewart Grace , Otieno Phelgona , Liang Xiaowu , Waitumbi John , Kimani Francis , Camerini David , Felgner Philip L. , Walson Judd L. , Vigil Adam 
Published: September 2011

AbstractIntroduction: Humoral immune responses play a pivotal role in naturally acquired immunity to malaria. Understanding which humoral responses are impaired among individuals at higher risk for malaria may improve our understanding of malaria immune control and contribute to vaccine development.Methods: We compared humoral responses with 483 Plasmodium falciparum antigens between adults in, Kisumu (high, year‐long malaria transmission leading to partial immunity), and adults in Kisii (low, seasonal malaria transmission). Then within each site, we compared malaria‐specific humoral responses between those at higher risk for malaria (CD4+≤500) and those at lower risk for malaria (CD4+>500). A protein microarray chip containing 483 P. falciparum antigens and 71 HIV antigens was used. Benjamini–Hochberg adjustments were made to control for multiple comparisons.Results: Fifty‐seven antigens including CSP, MSP1, LSA1 and AMA1 were identified as significantly more reactive in Kisumu than in Kisii. Ten of these antigens had been identified as protective in an earlier study. CD4+ T‐cell count did not significantly impact humoral responses.Conclusion: Protein microarrays are a useful method to screen multiple humoral responses simultaneously. This study provides useful clues for potential vaccine candidates. Modest decreases in CD4 counts may not significantly impact malaria‐specific humoral immunity.
The salivary proteome: Challenges and perspectives
Authors: Siqueira Walter L. , Dawes Colin 
Published: September 2011

AbstractWe provide a brief overview of the salivary proteome but with an emphasis on the major challenges in protein identification and quantitation. Precautions are necessary to avoid proteolysis, deglycosylation and dephosphorylation of salivary proteins by microbial and host enzymes in saliva. Many proteins are differentially expressed in secretions from different salivary glands and their proportional contributions to saliva vary with the flow rate. The total protein concentration in the secretion from any one gland varies considerably, depending on factors such as flow rate, duration of stimulation, nature of the stimulus and circadian rhythms. Many plasma proteins enter saliva via gingival crevicular fluid, of which there are increased amounts in persons with gingivitis or periodontal disease. These factors must be taken into account in the identification of potential biomarkers for different oral or systemic diseases.
Small‐Angle Neutron Scattering and Contrast Variation Measurement of the Interfacial Surface Area in PBX 9501 as a Function of Pressing Intensity
Authors: Mang Joseph T. , Hjelm Rex P. 
Published: September 2011

AbstractSmall‐angle neutron scattering with contrast variation was used to measure the interfacial surface area in a composite high explosive formulated with a deuterated binder. Continuing our work on the effect of varying the pressing intensity on void and binder size distribution, the effect of pressing intensity on the three interfaces (HMX‐binder, HMX‐voids and binder‐voids) of the PBX 9501 microstructure was studied. Formulation of PBX 9501 with a deuterated binder allowed the neutron scattering length density contrast to be varied and thus allowed differentiation of the three interfaces. Porod analysis was used to measure the surface area. The surface area at the interfaces of HMX and binder was found to increase with increasing pressing intensity, while the surface area between HMX and voids may have decreased slightly. No evidence was found for voids within the binder at any pressing intensity.
Protein loop closure using orientational restraints from NMR data
Authors: Tripathy Chittaranjan , Zeng Jianyang , Zhou Pei , Donald Bruce Randall 
Published: September 2011

AbstractProtein loops often play important roles in biological functions. Modeling loops accurately is crucial to determining the functional specificity of a protein. Despite the recent progress in loop prediction approaches, which led to a number of algorithms over the past decade, few rigorous algorithmic approaches exist to model protein loops using global orientational restraints, such as those obtained from residual dipolar coupling (RDC) data in solution nuclear magnetic resonance (NMR) spectroscopy. In this article, we present a novel, sparse data, RDC‐based algorithm, which exploits the mathematical interplay between RDC‐derived sphero‐conics and protein kinematics, and formulates the loop structure determination problem as a system of low‐degree polynomial equations that can be solved exactly, in closed‐form. The polynomial roots, which encode the candidate conformations, are searched systematically, using provable pruning strategies that triage the vast majority of conformations, to enumerate or prune all possible loop conformations consistent with the data; therefore, completeness is ensured. Results on experimental RDC datasets for four proteins, including human ubiquitin, FF2, DinI, and GB3, demonstrate that our algorithm can compute loops with higher accuracy, a three‐ to six‐fold improvement in backbone RMSD, versus those obtained by traditional structure determination protocols on the same data. Excellent results were also obtained on synthetic RDC datasets for protein loops of length 4, 8, and 12 used in previous studies. These results suggest that our algorithm can be successfully applied to determine protein loop conformations, and hence, will be useful in high‐resolution protein backbone structure determination, including loops, from sparse NMR data. Proteins 2012. © 2011 Wiley Periodicals, Inc.
Examples of safety studies and SIL analysis on the ammonia plants of OCI Nitrogen
Authors: Duisters Harrie 
Published: September 2011

AbstractA safety audit is almost invariably performed on new plant designs in the chemical industry. This will include at least a Hazop study of the basic design. Many plant owners also require an analysis of the safety integrity level or other methods of the installed safety measures.The concept of acceptable risk changes with time, but many existing plants operate year after year without a systematic assessment of the safety level, even if the plant is revamped or modified. In addition, operating procedures may change without all safety aspects being considered in a formalized way. This sometimes leads to very dangerous and costly incidents, which could have been avoided if regular and systematic safety audits had been performed.This article will discuss the systematic safety assessments that are performed at regular intervals on the 40‐ and 27‐years old OCI Nitrogen ammonia plants in The Netherlands. Examples are presented showing learning points that were found after a Hazop and a SIL analysis. © 2011 American Institute of Chemical Engineers Process Saf Prog, 2012
AlGaN/GaN heterojunction bipolar transistors by ammonia molecular beam epitaxy
Authors: Raman Ajay , Hurni Christophe A. , Speck James S. , Mishra Umesh K. 
Published: September 2011

AbstractWe demonstrate AlGaN/GaN heterojunction bipolar transistors (HBTs) by ammonia molecular beam epitaxy (NH3 MBE). The several benefits offered by NH3 MBE for the growth of GaN based vertical electronic devices are discussed. To obtain good ohmic contacts to the base layer, devices were fabricated with two different processes involving regrowths – regrown base contact (Wafer A) and regrown emitter (Wafer B). Devices on Wafers A and B had similar DC performance. Common emitter (CE) operation with a peak collector current density, JC > 1 kA/cm2 was obtained from devices on both wafers. In CE operation, a current gain (β) of 1.5–3 is observed in devices on both wafers. High base resistance is found to limit the current gain in CE operation, by limiting the base‐emitter bias voltage in the active region of the device. Maximum β values observed from Gummel plots at a fixed base‐collector (BC) bias of zero volts, are β ∼ 15 at JC = 0.88 kA/cm2 for Wafer A and β ∼13.5 at JC = 3 kA/cm2 for Wafer B. In devices on both wafers, variation is observed in the plots of β versus IC (collector current) for devices with the same emitter dimensions and geometry but with different lateral spacing between emitter mesa and base contacts (WEB). Peak β obtained is also observed to vary with WEB. An explanation is provided for the observed behaviour. This work demonstrates the potential of NH3 MBE for the growth of GaN HBTs.
GaN‐based p–i–n X‐ray detection
Authors: Yao Changsheng , Fu Kai , Wang Guo , Yu Guohao , Lu Min 
Published: September 2011

AbstractGaN‐based p–i–n X‐ray detectors have been fabricated. We observed using SEM that the surface of a GaN sample has a large number of hexagonal defects. The SEM results show that GaN itself contains numerous screw dislocations that will be the flow channel of leakage current, which in turn increased the reverse‐bias leakage current of detectors. We have observed a two‐step increase in X‐ray photocurrent, which is caused by two different detection mechanisms: photovoltaic and photoconductive, and the total photocurrent (Jp) to dark current (Jd) ratio is about 27.7 times and the net photocurrent is about 2.52 µA at 110 V reverse bias. As the X‐ray accelerating voltage increases, the photocurrent has a sublinear trend.
Ultra‐fast efficient synthesis of one‐dimensional nanostructures
Authors: Dąbrowska Agnieszka , Huczko Andrzej , Soszyński Michał , Bendjemil Badis , Micciulla Federico , Sacco Immacolata , Coderoni Laura , Bellucci Stefano 
Published: September 2011

AbstractSelf‐propagating high‐temperature synthesis (SHS) can be regarded as an efficient method to obtain new nanomaterials. Different starting mixtures of magnesium powder with various carbonates (Li2CO3, Na2CO3, CaCO3, FeCO3, (NH4)2CO3) were tried and the auto‐thermal reactions were carried out under both reactive (air) and neutral atmosphere (argon) with an initial pressure of 1 or 10 atm to yield novel nanomaterials. Both SiC nanofibres and novel branched SiC nanostructures were also obtained from Si/polytetrafluoroethylene (PTFE) mixtures and their synthesis and purification have been optimized. The application of those one‐dimensional (1‐D) SiC nanostructures as a composite filler is presented.
Magnetoconductance of carbon nanotubes probed in parallel magnetic fields up to 60 T
Authors: Jhang Sung Ho , Margańska Magdalena , del Valle Miriam , Skourski Yurii , Grifoni Milena , Wosnitza Joachim , Strunk Christoph 
Published: September 2011

AbstractMagnetoconductance of carbon nanotubes (CNTs) is investigated. We clearly show that a semiconducting CNT can be converted into a metallic one, or vice versa, with the application of a large magnetic field parallel to the tube axis, providing a consistent confirmation of the Aharonov–Bohm (AB) effect on the band structure of CNTs. We also demonstrate that magnetic‐field values where the semiconductor‐to‐metal transition occurs can be tuned by mechanical strain. Combined control of both the strain and the AB effect may open up new possibilities for CNT devices. In addition, we propose an idea to manipulate spin‐split subbands of CNTs, resulting from spin–orbit interaction (SOI), by using the magnetic field to generate sizeable spin‐polarized currents.magnified image
Split magnetoconductance peak due to SOI.
Dual action of light in photodarkened Ge–As–S films
Authors: Arsova Darina , Vateva Elena 
Published: September 2011

AbstractIn annealed chalcogenide films, thinner than 1 µm, highly expressed photodarkening (PD) can be fully restored after prolonged illumination. It was supposed that this light annealing effect (LAE) results from the dual action of light, which provokes not only increase of network disorder at PD but also decrease of disorder leading to photobleaching (PB), competing with PD. To confirm it, the changes of two parameters of disorder are studied: the Tauc slope B1/2, dependent on network bonding character, and the Urbach energy Eu, associated with tailing of the band edges. It is found that B1/2 decreases during PD and increases when PB overcomes the PD, which is direct evidence that the basis of the LAE is the dual action of light. The changes of disorder defined by Eu are found to be mostly inversely related to the changes of B1/2. The peculiarities of this relationship after various treatments are presented and the problem of the correspondence of both parameters of disorder is discussed.
Ab initio investigations on ballistic transport through carbon atomic chains attached to armchair and zigzag edged graphene electrodes
Authors: Ambavale S. K. , Sharma A. C. 
Published: September 2011

AbstractBallistic transport through carbon atomic chain (CAC) attached to relaxed armchair graphene (ACG), zigzag graphene (ZZG), and unrelaxed armchair graphene (UACG) electrodes have been investigated, as a function of energy measured from Fermi level with the use of PWSCF code of Quantum Espresso package. Our computed results show that the equilibrium conductance of CAC attached to ZZG‐electrodes tends to zero over a wide energy range across Fermi level. Similar behaviour of conductance is not seen when ZZG electrodes are replaced by ACG electrodes. CAC connected to ACG electrode is found better conducting as compared to CAC connected to ZZG electrode. The computed conductance, for a fixed energy value, strongly depends on whether CAC is attached to ZZG, ACG or UACG electrodes, suggesting that transport through electrode–CAC–electrode system depends on electrode edge structure. On comparing conductance of CAC connecting to graphene electrodes with that of CAC attached to metallic (Al) electrodes, we find that replacement of metallic electrode by graphene makes conductance smoother over wider energy range.magnified image
An improved discrete logarithm‐based multisignature scheme
Authors: Wang Lian Jie , Chen Jonathan Jen‐Rong 
Published: September 2011

ABSTRACTMany researchers have investigated the Rivest, Shamir, and Adleman (RSA) and ElGamal algorithms for digital multisignatures. Computational and communicational costs increase rapidly after a series of signings; these methods are unsuitable for organizations with multiple geographic locations. Because these methods require many online tasks, problems such as theft, data falsification, and masquerading often occur. This study therefore proposes a digital multisignature scheme that decreases computational costs and achieves quick validation. Copyright © 2011 John Wiley & Sons, Ltd.
Study on molecular mechanism for improving neural regeneration after repair of sciatic nerve defect in rat by acellular nerve allograft
Authors: Zhang Lixin , Lv Xiaoying , Tong Xiaojie , Jia Hua , Li Zhenhua 
Published: September 2011

AbstractObjective: Discuss the molecular mechanism for improving neural regeneration after repair of sciatic nerve defect in rat by acellular nerve allograft (ANA). Methods: Randomly divide 36 Wistar rats into six groups as normal control group, autografting group, and bridging groups of 2, 4, 8, 12 weeks, six rats for each group. Observe the expression of brain‐derived neurotrophic factor (BDNF) in L4 spinal cord and anterior tibial muscle at the injury site, calcitonin gene‐related peptide (CGRP) protein as well as mRNA, respectively. 12w after operation, histopathological observation was performed. Results: 2w after ANA bridging the sciatic nerve defect in rats, it was observed that the expression level of BDNF in spinal cord at the injury site and CGRP protein increased, reaching the peak level at 4w, lasting till 8w, then decreased but still significantly higher than that in normal control group at 12w, and was not significantly different compared with that in autografting group. However, the expression level of BDNF in anterior tibial muscle decreased gradually within the initial 4w, then increased progressively, reaching normal level at 12w, and was not significantly different compared with that in autografting group. The expression of BDNF mRNA and CGRPmRNA was essentially the same. 12w after operation, there was nerve regeneration in bridging group of 12w and autografting group. Conclusions: ANA possessed fine histocompatibility, and might substitute autograft to repair long‐segment defect of sciatic nerve in rats. This action might be related to upregulation of protein and mRNA expression for BDNF and CGRP in spinal cord. Synapse, 2012. © 2011 Wiley Periodicals, Inc.
TRPV1 antagonist, A‐889425, inhibits mechanotransmission in a subclass of rat primary afferent neurons following peripheral inflammation
Authors: Brederson Jill‐Desiree , Chu Katharine L. , Reilly Regina M. , Brown Brian S. , Kym Philip R. , Jarvis Michael F. , McGaraughty Steve 
Published: September 2011

AbstractTRPV1 (transient receptor potential vanilloid family type 1) is a nonselective cation channel that is activated and/or sensitized by noxious heat, protons, and other endogenous molecules released following tissue injury. In addition, a role for TRPV1 in mechanotransmission is emerging. We have recently reported that a selective TRPV1 receptor antagonist, A‐889425, reduces mechanical allodynia and spinal neuron responses to mechanical stimulation of complete Freund's adjuvant (CFA)‐inflamed rat hind paws. The population of peripheral nerve fibers through which TRPV1 antagonists mediate their effect on mechanotransmission have not yet been described. The objective of this study was to characterize TRPV1‐mediated modulation of mechanically evoked activity in sensory axons innervating rat hind paws. We used an in vitro skin‐nerve preparation to record neural activity from single axons isolated from rat tibial nerve. Single fibers were classified by conduction velocity, mechanical threshold, and stimulus–response relationships. We used A‐889425 to investigate uninjured and inflamed skin afferent neuron populations to evoked mechanical stimulation. Application of A‐889425 had no effect on the mechanical responsiveness of Aδ and C‐fiber units innervating uninjured skin. In contrast, A‐889425 inhibited responses of slowly conducting Aδ fiber units to noxious mechanical stimulation in a population of axons innervating CFA‐inflamed hind paws. These data support a role for TRPV1 in mechanotransmission following peripheral inflammation, and highlight the importance of a distinct subclass of primary afferent neurons in mediating this effect. Synapse, 2012. © 2011 Wiley Periodicals, Inc.
Effect of various dating formulae on sonographic estimation of gestational age in extremely preterm infants
Authors: Simic M. , Amer‐WÅhlin I. , Maršál K. , Källén K. 
Published: September 2011

AbstractObjectivesGestational age (GA) is one of the most important obstetric factors and prediction of date of delivery is usually based on ultrasonographic fetal measurements. Our aim was to determine whether applying three different dating formulae to a cohort of extremely preterm infants influenced the estimation of their GA.MethodsThis was a study of 513 infants delivered before 27 gestational weeks, included in a Swedish national population study (EXPRESS), with information available on mid‐trimester ultrasonographically measured biparietal diameter and femur length. We applied using these parameters three dating formulae, the Persson & Weldner formula, commonly used in Sweden, the Hadlock formula and the Mul formula, and compared their GA estimates to the clinically reported GA (recorded at delivery) and the last menstrual period (LMP)‐based GA.ResultsThe mean reported GA was 173.2 days, corresponding well to the GA according to the Persson & Weldner dating formula (173.3). The mean GA according to LMP, the Hadlock formula and the Mul formula were 176.8, 175.3 and 175.6 days, respectively. The Hadlock and Mul GA estimates differed significantly from that based on the Persson & Weldner formula (both P‐values < 10−6). Among 68 pregnancies with a reported duration of 22 weeks, 33 (49%) had a duration of 23 weeks or more when GA was calculated according to LMP and 22 (32%) when GA was calculated according to the Hadlock formula.ConclusionEstimated GA among infants delivered before 27 gestational weeks varied significantly depending on the dating formula used to calculate the estimated date of delivery; this might influence the clinical management of extremely preterm fetuses and infants. Copyright © 2012 ISUOG. Published by John Wiley & Sons, Ltd.
Ultrasonographic fetal head position to predict mode of delivery: a systematic review and bivariate meta‐analysis
Authors: Verhoeven C. J. M. , Rückert M. E. P. F. , Opmeer B. C. , Pajkrt E. , Mol B. W. J. 
Published: September 2011

AbstractObjectiveWe performed a systematic review to determine whether sonographic assessment of occipital position of the fetal head can contribute to the prediction of the mode of delivery.MethodsWe performed a systematic literature search of electronic databases from inception to May 2011. Two reviewers independently extracted data from the included studies. We used a bivariate model to estimate point estimates for sensitivity and specificity curves for the outcome Cesarean delivery. Eligible studies were cohort studies or cross‐sectional studies that reported on both the position of the fetal head, as assessed by ultrasound, before or at the beginning of active labor as well as the outcome of labor in women at term.ResultsWe included 11 primary articles reporting on 5053 women, of whom 898 had a Cesarean section. All studies indicated disappointing values for sensitivity and specificity in the prediction of Cesarean section. Summary point estimates of sensitivity and specificity were 0.39 (95% CI, 0.32–0.48) and 0.71 (95% CI, 0.67–0.74), respectively.ConclusionSonographic assessment of occipital position of the fetal head before delivery should not be used in the prediction of mode of delivery. Copyright © 2012 ISUOG. Published by John Wiley & Sons, Ltd.
A Basic Bismuth(III) Dodecahydro‐closo‐Dodecaborate Hydrate: [Bi6O4(OH)4][B12H12]3·10H2O
Authors: Zimmermann Lucas W. , Schleid Thomas 
Published: September 2011

AbstractThe reaction of Bi2O3 with an aqueous solution of(H3O)2[B12H12] leads to a basic bismuth(III) dodecahydro‐closo‐dodecaborate hydrate in the shape of colorless, hexagonally plate‐shaped single crystals. The new compound with the formula [Bi6O4(OH)4][B12H12]3·10H2O crystallizes in the monoclinic space group P21/c(a = 1837.15(9), b = 1810.64(9), c = 1360.28(7) pm, β = 90.867(3)°) with four formula units per unit cell. The crystal structure contains six crystallographically independent Bi3+ cations forming an octahedral (Bi3+)6 cluster with eight oxygen atoms capping all octahedral faces. Four of these particles represent oxide anions, whereas the other four belong to hydroxide groups. These eight oxidic ligands themselves arrange around the (Bi3+)6 cluster in the shape of a trigonal dodecahedron. Furthermore seven water molecules are situated around each cationic [Bi6O4(OH)4]6+ complex to complete the coordination sphere of every Bi3+ cation and three more serve to fill up voids in the crystal structure. In addition, direct hydrogen contacts of the quasi‐icosahedral [B12H12]2– anions to the bismuth(III) cations occur. Despite this fact the icosahedral shape of these charge‐compensating [B12H12]2– cluster anions is only slightly distorted.