bluuebunny/crossref_metadata_2025_split huggingface dataset:
Implementation of community‐based adherence clubs for stable antiretroviral therapy patients in Cape Town, South Africa
Authors: Grimsrud Anna , Sharp Joseph , Kalombo Cathy , Bekker Linda‐Gail , Myer Landon 
Published: May 2015

IntroductionCommunity‐based models of antiretroviral therapy (ART) delivery have been recommended to support ART expansion and retention in resource‐limited settings. However, the evidence base for community‐based models of care is limited. We describe the implementation of community‐based adherence clubs (CACs) at a large, public‐sector facility in peri‐urban Cape Town, South Africa.MethodsStarting in May 2012, stable ART patients were down‐referred from the primary care community health centre (CHC) to CACs. Eligibility was based on self‐reported adherence, >12 months on ART and viral suppression. CACs were facilitated by four community health workers and met every eight weeks for group counselling, a brief symptom screen and distribution of pre‐packed ART. The CACs met in community venues for all visits including annual blood collection and clinical consultations. CAC patients could send a patient‐nominated treatment supporter (“buddy”) to collect their ART at alternate CAC visits. Patient outcomes [mortality, loss to follow‐up and viral rebound (>1000 copies/ml)] during the first 18 months of the programme are described using Kaplan–Meier methods.Results and DiscussionFrom June 2012 to December 2013, 74 CACs were established, each with 25–30 patients, providing ART to 2133 patients. CAC patients were predominantly female (71%) and lived within 3 km of the facility (70%). During the analysis period, 9 patients in a CAC died (<0.1%), 53 were up‐referred for clinical complications (0.3%) and 573 CAC patients sent a buddy to at least one CAC visit (27%). After 12 months in a CAC, 6% of patients were lost to follow‐up and fewer than 2% of patients retained experienced viral rebound.ConclusionsOver a period of 18 months, a community‐based model of care was rapidly implemented decentralizing more than 2000 patients in a high‐prevalence, resource‐limited setting. The fundamental challenge for this out of facility model was ensuring that patients receiving ART within a CAC were viewed as an extension of the facility and part of the responsibility of CHC staff. Further research is needed to support down‐referral sooner after ART initiation and to describe patient experiences of community‐based ART delivery.
Asymmetric magnetospheric compressions and expansions in response to impact of inclined interplanetary shock
Authors: Samsonov A. A. , Sergeev V. A. , Kuznetsova M. M. , Sibeck D. G. 
Published: May 2015

AbstractWe use global MHD simulations to model the magnetospheric response to an inclined shock that first strikes the duskside magnetosphere. The simulations predict several phenomena related specifically to the inclined shocks. The magnetospheric compression on the duskside exceeds that on the dawnside, and the geocentric distance to the dusk magnetopause varies in a simple step‐like form. The compression on the dawnside is preceded and followed by expansions. For a moderately strong shock, the expansion magnitude reaches severalREbehind the terminator plane. The magnetopause and cross‐tail currents in the magnetotail are significantly deformed during and after the shock passage. The position of the magnetotail magnetopause moves by more than 10 RE. This asymmetric magnetopause deformation is mainly related to a strong |Vy| downstream from the inclined shock. The magnetospheric expansion results in a decrease in the horizontal magnetic field at low‐latitude stations, as confirmed by observations.
Repulsive hydration forces between calcite surfaces and their effect on the brittle strength of calcite‐bearing rocks
Authors: Røyne Anja , Dalby Kim N. , Hassenkam Tue 
Published: May 2015

AbstractThe long‐term mechanical strength of calcite‐bearing rocks is highly dependent on the presence and nature of pore fluids, and it has been suggested that the observed effects are due to changes in nanometer‐scale surface forces near fracture tips and grain contacts. In this letter, we present measurements of forces between two calcite surfaces in air and water‐glycol mixtures using the atomic force microscope. We show a time‐ and load‐dependent adhesion at low water concentrations and a strong repulsion in the presence of water, which is most likely due to hydration of the strongly hydrophilic calcite surfaces. We argue that this hydration repulsion can explain the commonly observed water‐induced decrease in strength in calcitic rocks and single calcite crystals. Furthermore, this relatively simple experimental setup may serve as a useful tool for analyzing surface forces in other mineral‐fluid combinations.
Postseismic relaxation in Kashmir and lateral variations in crustal architecture and materials
Authors: Bendick R. , Khan S. F. , Bürgmann R. , Jouanne F. , Banerjee P. , Khan M. A. , Bilham R. 
Published: May 2015

AbstractThirty horizontal displacement time series from GPS sites in the area around the 2005 Kashmir earthquake show lateral spatial variations in displacement magnitude and relaxation time for the postseismic interval from 2005 to 2012. The observed spatial pattern of surface displacements can only be reproduced by finite element models of postseismic deformation in elastic over viscoelastic crust that include lateral differences in both the thickness of the elastic layer and the viscosity of the viscoelastic layer. Solutions reproducing the sign of horizontal displacements everywhere in the epicentral region also require afterslip on the portion of the fault dislocation in the viscoelastic layer but not in the elastic lid. Although there are substantial tradeoffs among contributions to postseismic displacements of the surface, the observations preclude both crustal homogeneity and shallow afterslip. In the best family of solutions, the thickness of the elastic upper crust differs by a factor of 5 and the viscosity of the middle and lower crust by an order of magnitude between domains north and south of a suture zone containing the Main Boundary Thrust and Main Mantle Thrust.
Hydraulic sealing due to pressure solution contact zone growth in siliciclastic rock fractures
Authors: Lang P. S. , Paluszny A. , Zimmerman R. W. 
Published: May 2015

AbstractThermo‐hydro‐mechanical‐chemical simulations at the pore scale are conducted to study the hydraulic sealing of siliciclastic rock fractures as contact zones grow driven by pressure dissolution. The evolving fluid‐saturated three‐dimensional pore space of the fracture results from the elastic contact between self‐affine, randomly rough surfaces in response to the effective confining pressure. A diffusion‐reaction equation controls pressure solution over contact zones as a function of their emergent geometry and stress variations. Results show that three coupled processes govern the evolution of the fracture's hydraulic properties: (1) the dissolution‐driven convergence of the opposing fracture walls acts to compact the pore space; (2) the growth of contact zones reduces the elastic compression of the pore space; and (3) the growth of contact zones leads to flow channeling and the presence of stagnant zones in the flow field. The dominant early time compaction mechanism is the elastic compression of the fracture void space, but this eventually becomes overshadowed by the irreversible process of pressure dissolution. Growing contact zones isolate void space and cause an increasing disproportion between average and hydraulic aperture. This results in the loss of hydraulic conductivity when the mean aperture is a third of its initial value and the contact ratio approaches the characteristic value of one half. Convergence rates depend on small‐wavelength roughness initially and on long‐wavelength roughness in the late time. The assumption of a characteristic roughness length scale, therefore, leads to a characteristic time scale with an underestimation of dissolution rates before and an overestimation thereafter.
Understanding the Association of Fatigue With Other Symptoms of Fibromyalgia: Development of a Cluster Model
Authors: Lukkahatai Nada , Walitt Brian , Espina Alexandra , Gelio Alves , Saligan Leorey N. 
Published: May 2015

ObjectiveTo develop a symptoms cluster model that can describe factors of fibromyalgia syndrome (FMS) associated with fatigue severity as reported by the sample and to explore FMS clinical symptom subclusters based on varying symptom intensities.MethodsFMS individuals (n = 120, 82% ages 31–60 years, 90% women, 59% white) diagnosed with the 1990 or 2010 American College of Rheumatology diagnostic criteria were enrolled. Participants completed multiple validated self‐report questionnaires to measure fatigue, pain, depression, anxiety, pain catastrophizing, daytime sleepiness, cognitive function, and FMS‐related polysymptomatic distress. Cluster analysis using SPSS 19.0 and structural equation modeling using AMOS 17.0 were used.ResultsFinal structural equation modeling the symptoms cluster model showed good fit and revealed that FMS fatigue was associated with widespread pain, symptoms severity, pain intensity, pain interference, cognitive dysfunction, catastrophizing, anxiety, and depression (χ2 = 121.72 (98df), P > 0.05, χ2/df = 1.242, comparative fit index = 0.982, root mean square error of approximation = 0.045). Two distinct clinical symptom subclusters emerged: subcluster 1 (78% of total subjects), defined by widespread pain, unrefreshed waking, and somatic symptoms, and subcluster 2 (22% of total subjects), defined by fatigue and cognitive dysfunction with pain being a less severe and less widespread occurrence.ConclusionOverall, subcluster 1 had more intense symptoms than subcluster 2. FMS symptoms may be categorized into 2 clinical subclusters. These findings have implications for an illness whose diagnosis and management are symptom dependent. A longitudinal study capturing the variability in the symptom experience of FMS subjects is warranted.
Association of Anemic Hypoxia and Increased Pulmonary Artery Systolic Pressure in Patients With Systemic Lupus Erythematosus
Authors: Kim Ki‐Jo , Baek In‐Woon , Yoon Chong‐Hyeon , Kim Wan‐Uk , Cho Chul‐Soo 
Published: May 2015

ObjectivePulmonary arterial hypertension (PAH) is a rare but serious complication of systemic lupus erythematosus (SLE). Chronic hypoxia is known to cause PAH resulting from pulmonary vascular remodeling. We investigated the association between anemic hypoxia and PAH in SLE patients.MethodsSystolic pulmonary artery pressure (PAP) was measured in 132 SLE patients by echocardiography. Increased PAP was defined as resting PAP > 40 mm Hg. Oxygen delivery (DO2) was estimated as the product of cardiac output and arterial oxygen content.ResultsOf 132 patients, 17 (12.9%) had increased PAP, and these patients had significantly lower DO2 values than patients with normal PAP (P = 0.002). The DO2 values inversely correlated with PAP values (γ = −0.308, P < 0.001) and plasma N‐terminal pro–brain natriuretic peptide levels (γ = −0.323, P = 0.001), but positively correlated with hemoglobin levels (γ = 0.402, P < 0.001). Compared to those with normal PAP, patients with increased PAP had significantly longer durations of anemia over the preceding 6–24 months. Patients with anemia of longer durations (≥3 months) in the preceding 6 months had a higher risk of increased PAP compared to those with shorter durations (P < 0.001). When SLE patients were divided into 3 groups according to hemoglobin and PAP, serum interleukin‐6 (IL‐6) levels increased across groups with higher PAP (P = 0.001 for trend), but decreased across tertiles of hemoglobin levels (P = 0.008 for trend).ConclusionOur data indicate an association between chronic anemic hypoxia and increased PAP in SLE patients and suggest that increased IL‐6 might participate in this process.
Merging Photoredox and Nickel Catalysis: The Direct Synthesis of Ketones by the Decarboxylative Arylation of α‐Oxo Acids
Authors: Chu Lingling , Lipshultz Jeffrey M. , MacMillan David W. C. 
Published: May 2015

AbstractThe direct decarboxylative arylation of α‐oxo acids has been achieved by synergistic visible‐light‐mediated photoredox and nickel catalysis. This method offers rapid entry to aryl and alkyl ketone architectures from simple α‐oxo acid precursors via an acyl radical intermediate. Significant substrate scope is observed with respect to both the oxo acid and arene coupling partners. This mild decarboxylative arylation can also be utilized to efficiently access medicinal agents, as demonstrated by the rapid synthesis of fenofibrate.
Prometabolites of 5‐Diphospho‐myo‐inositol Pentakisphosphate
Authors: Pavlovic Igor , Thakor Divyeshsinh T. , Bigler Laurent , Wilson Miranda S. C. , Laha Debabrata , Schaaf Gabriel , Saiardi Adolfo , Jessen Henning J. 
Published: May 2015

AbstractDiphospho‐myo‐inositol phosphates (PP‐InsPy) are an important class of cellular messengers. Thus far, no method for the transport of PP‐InsPy into living cells is available. Owing to their high negative charge density, PP‐InsPy will not cross the cell membrane. A strategy to circumvent this issue involves the generation of precursors in which the negative charges are masked with biolabile groups. A PP‐InsPy prometabolite would require twelve to thirteen biolabile groups, which need to be cleaved by cellular enzymes to release the parent molecules. Such densely modified prometabolites of phosphate esters and anhydrides have never been reported to date. This study discloses the synthesis of such agents and an analysis of their metabolism in tissue homogenates by gel electrophoresis. The acetoxybenzyl‐protected system is capable of releasing 5‐PP‐InsP5 in mammalian cell/tissue homogenates within a few minutes and can be used to release 5‐PP‐InsP5 inside cells. These molecules will serve as a platform for the development of fundamental tools required to study PP‐InsPy physiology.
Pharmakokinetik von Medikamenten durch Echtzeit‐Analyse der Atemluft von Mäusen
Authors: Li Xue , Martinez‐Lozano Sinues Pablo , Dallmann Robert , Bregy Lukas , Hollmén Maija , Proulx Steven , Brown Steven A. , Detmar Michael , Kohler Malcolm , Zenobi Renato 
Published: May 2015

AbstractMittels sekundärer Elektrosprayionisation und hochauflösender Massenspektrometrie wurde eine nichtinvasive Bestimmung der Pharmakokinetik (PK) von Ketamin, Propofol und Valproinsäure sowie deren Metaboliten in der Atemluft von Mäusen erzielt. Das PK‐Profil eines Medikaments beeinflusst dessen Wirksamkeit und Toxizität, weil es die Exposition und effektive Dosis bestimmt. Das Antidepressivum und Anästhetikum Ketamin und vier seiner Metaboliten wurden im Detail untersucht, und ihre PK gleichzeitig nach Verabreichen verschiedener sub‐anästhetischer Dosen von Ketamin bestimmt. Die Bioverfügbarkeit nach oraler Einnahme und intraperitonealer Injektion wurde ebenfalls untersucht. Im Gegensatz zu konventionellen Studien, bei denen selbst für PK‐Kurven niederer Auflösung viele Tiere geopfert werden müssen, ergibt die hier vorgestellte Echtzeit‐PK‐Bestimmung eine bisher unerreichte Zeitauflösung (10 s), und keines der Tiere musste getötet werden. Dies stellt somit einen wichtigen Schritt nicht nur für den Tierschutz, sondern auch eine große Kosten‐ und Zeitersparnis dar.
Thin‐Layer Chemical Modulations by a Combined Selective Proton Pump and pH Probe for Direct Alkalinity Detection
Authors: Afshar Majid Ghahraman , Crespo Gastón A. , Bakker Eric 
Published: May 2015

AbstractWe report a general concept based on a selective electrochemical ion pump used for creating concentration perturbations in thin layer samples (∼40 μL). As a first example, hydrogen ions are released from a selective polymeric membrane (proton pump) and the resulting pH is assessed potentiometrically with a second membrane placed directly opposite. By applying a constant potential modulation for 30 s, an induced proton concentration of up to 350 mM may be realized. This concept may become an attractive tool for in situ titrations without the need for sampling, because the thin layer eventually re‐equilibrates with the contacting bulk sample. Acid–base titrations of NaOH and Na2CO3 are demonstrated. The determination of total alkalinity in a river water sample is carried out, giving levels (23.1 mM) comparable to that obtained by standard methods (23.6 mM). The concept may be easily extended to other ions (cations, anions, polyions) and may become attractive for environmental and clinical applications.
Biocatalytic Pathway Selection in Transient Tripeptide Nanostructures
Authors: Pappas Charalampos G. , Sasselli Ivan R. , Ulijn Rein V. 
Published: May 2015

AbstractStructural adaption in living systems is achieved by competing catalytic pathways that drive assembly and disassembly of molecular components under the influence of chemical fuels. We report on a simple mimic of such a system that displays transient, sequence‐dependent formation of supramolecular nanostructures based on biocatalytic formation and hydrolysis of self‐assembling tripeptides. The systems are catalyzed by α‐chymotrypsin and driven by hydrolysis of dipeptide aspartyl‐phenylalanine‐methyl ester (the sweetener aspartame, DF‐OMe). We observed switch‐like pathway selection, with the kinetics and consequent lifetime of transient nanostructures controlled by the peptide sequence. In direct competition, kinetic (rather than thermodynamic) component selection is observed.
Kinetic Cooperativity in Human Pancreatic Glucokinase Originates from Millisecond Dynamics of the Small Domain
Authors: Larion Mioara , Hansen Alexandar L. , Zhang Fengli , Bruschweiler‐Li Lei , Tugarinov Vitali , Miller Brian G. , Brüschweiler Rafael 
Published: May 2015

AbstractThe hallmark of glucokinase (GCK), which catalyzes the phosphorylation of glucose during glycolysis, is its kinetic cooperativity, whose understanding at atomic detail has remained open since its discovery over 40 years ago. Herein, by using kinetic CPMG NMR spectroscopic data for 17 isoleucine side chains distributed over all parts of GCK, we show that the origin of kinetic cooperativity is rooted in intramolecular protein dynamics. Residues of glucose‐free GCK located in the small domain displayed distinct exchange behavior involving multiple conformers that are substantially populated (p>17 %) with a kex value of 509±51 s−1, whereas in the glucose‐bound form these exchange processes were quenched. This exchange behavior directly competes with the enzymatic turnover rate at physiological glucose concentrations, thereby generating the sigmoidal rate dependence that defines kinetic cooperativity.
Cage‐Like B41+ and B422+: New Chiral Members of the Borospherene Family
Authors: Chen Qiang , Zhang Su‐Yan , Bai Hui , Tian Wen‐Juan , Gao Ting , Li Hai‐Ru , Miao Chang‐Qing , Mu Yue‐Wen , Lu Hai‐Gang , Zhai Hua‐Jin , Li Si‐Dian 
Published: May 2015

AbstractThe newly discovered borospherenes B40−/0 and B39− mark the onset of a new class of boron nanostructures. Based on extensive first‐principles calculations, we introduce herein two new chiral members to the borospherene family: the cage‐like C1 B41+ (1) and C2 B422+ (2), both of which are the global minima of the systems with degenerate enantiomers. These chiral borospherene cations are composed of twelve interwoven boron double chains with six hexagonal and heptagonal faces and may be viewed as the cuborenes analogous to cubane (C8H8). Chemical bonding analyses show that there exists a three‐center two‐electron σ bond on each B3 triangle and twelve multicenter two‐electron π bonds over the σ skeleton. Molecular dynamics simulations indicate that C1 B41+ (1) fluctuates above 300 K, whereas C2 B422+ (2) remains dynamically stable. The infrared and Raman spectra of these borospherene cations are predicted to facilitate their experimental characterizations.
Microfluidic Formation of Membrane‐Free Aqueous Coacervate Droplets in Water
Authors: van Swaay Dirk , Tang T.‐Y. Dora , Mann Stephen , de Mello Andrew 
Published: May 2015

AbstractWe report on the formation of coacervate droplets from poly(diallyldimethylammonium chloride) with either adenosine triphosphate or carboxymethyl‐dextran using a microfluidic flow‐focusing system. The formed droplets exhibit improved stability and narrower size distributions for both coacervate compositions when compared to the conventional vortex dispersion techniques. We also demonstrate the use of two parallel flow‐focusing channels for the simultaneous formation and co‐location of two distinct populations of coacervate droplets containing different DNA oligonucleotides, and that the populations can coexist in close proximity up to 48 h without detectable exchange of genetic information. Our results show that the observed improvements in droplet stability and size distribution may be scaled with ease. In addition, the ability to encapsulate different materials into coacervate droplets using a microfluidic channel structure allows for their use as cell‐mimicking compartments.
Pd–Pb Alloy Nanocrystals with Tailored Composition for Semihydrogenation: Taking Advantage of Catalyst Poisoning
Authors: Niu Wenxin , Gao Yongjun , Zhang Weiqing , Yan Ning , Lu Xianmao 
Published: May 2015

AbstractMetallic nanocrystals (NCs) with well‐defined sizes and shapes represent a new family of model systems for establishing structure–function relationships in heterogeneous catalysis. Here in this study, we show that catalyst poisoning can be utilized as an efficient strategy for nanocrystals shape and composition control, as well as a way to tune the catalytic activity of catalysts. Lead species, a well‐known poison for noble‐metal catalysts, was investigated in the growth of Pd NCs. We discovered that Pb atoms can be incorporated into the lattice of Pd NCs and form Pd–Pb alloy NCs with tunable composition and crystal facets. As model catalysts, the alloy NCs with different compositions showed different selectivity in the semihydrogenation of phenylacetylene. Pd–Pb alloy NCs with better selectivity than that of the commercial Lindlar catalyst were discovered. This study exemplified that the poisoning effect in catalysis can be explored as efficient shape‐directing reagents in NC growth, and more importantly, as a strategy to tailor the performance of catalysts with high selectivity.
Fabrication and characterization of natural rubber/Imperata cylindrica cellulose fiber biocomposites
Authors: Thulasimani Chellon , Ramesh Subramaniam , Ramesh Kasi , Salmah Husseinsyah 
Published: May 2015

AbstractImperata cylindrica (IC) is one of the most abundantly found agricultural wastes that have been used to produce lignocellulose fiber and nanocellulose. Cellulose fiber from IC leaves has been isolated and characterized using Fourier transform infrared spectroscopy and scanning electron microscope. Biocomposite was prepared using Imperata cylindrica cellulose fiber (ICCF) as reinforcing filler and natural rubber (NR) as the matrix. The NR vulcanizates were cured with conventional vulcanization (CV) and efficient vulcanization (EV) curing system using two roll mills. The effect of ICCF content on curing characteristic, tensile properties, and morphology of ICCF‐filled NR vulcanizates was studied. The results indicated that the tensile strength and tensile modulus of EV system were higher compared with CV system. The tensile strength and modulus at 300% increased as the ICCF content increased accompanied by a moderate decrease in elongation at break. The morphology study of biocomposites showed that ICCF were dispersed better in the NR matrix. © 2015 Curtin University of Technology and John Wiley & Sons, Ltd.