bluuebunny/crossref_metadata_2025_split huggingface dataset:
Impaired distensibility of ascending aorta in patients with HIV infection
Authors: Zormpala Alexandra , Sipsas Nikolaos V , Moyssakis Ioannis , Georgiadou Sarah P , Gamaletsou Maria N , Kontos Athanasios N , Ziakas Panayiotis D , Kordossis Theodore 
Published: July 2012

Abstract

Background
Our aim was to investigate the aortic distensibility (AD) of the ascending aorta and carotid artery intima-media thickness (c-IMT) in HIV-infected patients compared to healthy controls.

Methods
One hundred and five HIV-infected patients (86 males [82%], mean age 41 ± 0.92 years), and 124 age and sex matched HIV-1 uninfected controls (104 males [84%], mean age 39.2 ± 1.03 years) were evaluated by high-resolution ultrasonography to determine AD and c-IMT. For all patients and controls clinical and laboratory factors associated with atherosclerosis were recorded.

Results
HIV- infected patients had reduced AD compared to controls: 2.2 ± 0.01 vs. 2.62 ± 0.01 10-6 cm2 dyn-1, respectively (p < 0.001). No difference was found in c-IMT between the two groups. In multiadjusted analysis, HIV infection was independently associated with decreased distensibility (beta –0.45, p < 0.001). Analysis among HIV-infected patients showed that patients exposed to HAART had decreased AD compared to HAART-naïve patients [mean (SD): 2.18(0.02) vs. 2.28(0.03) 10-6 cm2 dyn-1, p = 0.01]. In multiadjusted analysis, increasing age and exposure to HAART were independently associated with decreased AD.

Conclusion
HIV infection is independently associated with decreased distensibility of the ascending aorta, a marker of subclinical atherosclerosis. Increasing age and duration of exposure to HAART are factors further contributing to decreased AD.
Cardiac vagal control and theoretical models of co-occurring depression and anxiety: A cross-sectional psychophysiological study of community elderly
Authors: Chen Hsi-Chung , Yang Cheryl C H , Kuo Terry B J , Su Tung-Ping , Chou Pesus 
Published: July 2012

Abstract

Background
In order to elucidate the complex relationship between co-occurring depression and anxiety with cardiac autonomic function in the elderly, this study examined the correlation between cardiac vagal control (CVC) and pre-defined, theoretical factors from the Hospital Anxiety and Depression Scale (HADS).

Methods
Three hundred fifty-four randomly selected Chinese male subjects aged ≥65 years and living in the community were enrolled. CVC was measured using a frequency-domain index of heart rate variability.

Results
Confirmatory factor analysis showed that the flat tripartite model of HADS provided a modest advantage in model fit when compared with other theoretical factor solutions. In the flat tripartite model, there was a significant negative association between anhedonic depression and CVC. In contrast, autonomic anxiety showed a significant positive correlation with CVC. In the hierarchical tripartite model, negative affectivity was not directly associated with CVC; instead, it had positive and negative indirect effects on CVC via autonomic anxiety and anhedonic depression, respectively. As scores for negative affectivity increased, these specific indirect effects diminished.

Conclusions
Among competing models of co-occurring depression and anxiety, constructs from tripartite models demonstrate fair conformity with the data but unique and distinct correlations with CVC. Negative affectivity may determine the relationship of anhedonic depression and autonomic anxiety with CVC. Separating affective symptoms under the constructs of the tripartite models helps disentangle complex associations between co-occurring depression and anxiety with CVC.
Heterologous expression of human costimulatory molecule B7-2 and construction of B7-2 immobilized polyhydroxyalkanoate nanoparticles for use as an immune activation agent
Authors: Li Ming-Chuan , Liu Qian-Qian , Lu Xiao-Yun , Zhang Ya-Li , Wang Lei-Lei 
Published: July 2012

Abstract

Background
Costimulation of T cells via costimulatory molecules such as B7 is important for eliciting cell-mediated antitumor immunity. Presenting costimulation molecules by immobilizing recombinant B7 on the surface of nanovectors is a novel strategy for complementary therapy. Polyhydroxyalkanoates (PHAs) are a family of biodegradable, non-toxic, biocompatible polyesters, which can be used as a nonspecific immobilizing matrix for protein presentation. Recombinant protein fusion with PHA granule binding protein phasin (PhaP) can be easily immobilized on the surface of PHA nanoparticles through hydrophobic interactions between PhaP and PHA, and therefore provides a low-cost protein presenting strategy.

Results
In this study, the extracellular domain of the B7-2 molecule (also named as CD86) was fused with PhaP at its N-terminal and heterogeneously expressed in recombinant Escherichia coli strain BL21 (DE3). The purified B7-2-PhaP protein was immobilized on the surface of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx)-based nanoparticles. Loading of 240 μg (3.2 pMol) of B7-2-PhaP protein per mg nanoparticles was achieved. Immobilized B7-2-PhaP on PHBHHx nanoparticles induced T cell activation and proliferation in vitro.

Conclusions
A PHA nanoparticle-based B7-2 costimulation molecule-presenting system was constructed. The PHA-based B7 presenting nanosystem provided costimulation signals to induce T cell activation and expansion in vitro. The B7-2-PhaP immobilized PHA nanosystem is a novel strategy for costimulation molecule presentation and may be used for costimulatory molecule complementary therapy.
Zinc erythrocyte protoporphyrin as marker of malaria risk in pregnancy - a retrospective cross-sectional and longitudinal study
Authors: Senga Edward L , Koshy Gibby , Brabin Bernard J 
Published: July 2012

Abstract

Background
The effects of iron interventions and host iron status on infection risk have been a recurrent clinical concern, although there has been little research on this interaction in pregnant women.

Methods
Cross-sectional and longitudinal analyses were undertaken to determine the association of whole blood zinc erythrocyte protoporphyrin (ZPP) with malaria parasitaemia in pregnant women attending antenatal and delivery care at Montfort and Chikwawa Hospitals, Shire Valley, Malawi. Prevalence of antenatal, delivery and placental malaria was assessed in relation to maternal ZPP levels. The main outcome measures were prevalence of peripheral and placental Plasmodium falciparum parasitaemia and odds ratios of malaria risk.

Results
A total of 4,103 women were evaluated at first antenatal visit, of whom at delivery 1327 were screened for peripheral and 1285 for placental parasitaemia. Risk of malaria at delivery (peripheral or placental) was higher in primigravidae (p < 0.001), and lower (peripheral) with use of intermittent preventive anti-malarials during pregnancy (p < 0.001). HIV infection was associated with increased malaria parasitaemia (p < 0.02, peripheral or placental). Parasitaemia prevalence was lower in women with normal ZPP levels compared to those with raised concentrations at both first antenatal visit (all gravidae, p = 0.048, and at delivery (all gravidae, p < 0.001; primigravidae, p = 0.056). Between first antenatal visit and delivery women who transitioned from raised (at first antenatal visit) to normal ZPP values (at delivery) had lower peripheral parasitaemia prevalence at delivery compared to those who maintained normal ZPP values at both these visits (all gravidae: 0.70, 95%CI 0.4-1.1; primigravidae: 0.3, 0.1-0.8). In regression analysis this difference was lost with inclusion of HIV infection in the model.

Conclusions
Raised ZPP concentrations in pregnancy were positively associated with P. falciparum parasitaemia and were probably secondary to malaria inflammation, rather than indicating an increased malaria risk with iron deficiency. It was not possible from ZPP measurements alone to determine whether iron deficiency or repletion alters malaria susceptibility in pregnancy.
DNA-nanoparticle assemblies go organic: Macroscopic polymeric materials with nanosized features
Authors: Mentovich Elad D , Livanov Konstantin , Prusty Deepak K , Sowwan Mukules , Richter Shachar 
Published: July 2012

Abstract

Background
One of the goals in the field of structural DNA nanotechnology is the use of DNA to build up 2- and 3-D nanostructures. The research in this field is motivated by the remarkable structural features of DNA as well as by its unique and reversible recognition properties. Nucleic acids can be used alone as the skeleton of a broad range of periodic nanopatterns and nanoobjects and in addition, DNA can serve as a linker or template to form DNA-hybrid structures with other materials. This approach can be used for the development of new detection strategies as well as nanoelectronic structures and devices.

Method
Here we present a new method for the generation of unprecedented
all-organic
conjugated-polymer nanoparticle networks guided by DNA, based on a hierarchical self-assembly process. First, microphase separation of amphiphilic block copolymers induced the formation of spherical nanoobjects. As a second ordering concept, DNA base pairing has been employed for the controlled spatial definition of the conjugated-polymer particles within the bulk material. These networks offer the flexibility and the diversity of soft polymeric materials. Thus, simple chemical methodologies could be applied in order to tune the network's electrical, optical and mechanical properties.

Results and conclusions
One- two- and three-dimensional networks have been successfully formed. Common to all morphologies is the integrity of the micelles consisting of DNA block copolymer (DBC), which creates an all-organic engineered network.
Developing a comprehensive time series of GDP per capita for 210 countries from 1950 to 2015
Authors: James Spencer L , Gubbins Paul , Murray Christopher JL , Gakidou Emmanuela 
Published: July 2012

Abstract

Background
Income has been extensively studied and utilized as a determinant of health. There are several sources of income expressed as gross domestic product (GDP) per capita, but there are no time series that are complete for the years between 1950 and 2015 for the 210 countries for which data exist. It is in the interest of population health research to establish a global time series that is complete from 1950 to 2015.

Methods
We collected GDP per capita estimates expressed in either constant US dollar terms or international dollar terms (corrected for purchasing power parity) from seven sources. We applied several stages of models, including ordinary least-squares regressions and mixed effects models, to complete each of the seven source series from 1950 to 2015. The three US dollar and four international dollar series were each averaged to produce two new GDP per capita series.

Results and discussion
Nine complete series from 1950 to 2015 for 210 countries are available for use. These series can serve various analytical purposes and can illustrate myriad economic trends and features. The derivation of the two new series allows for researchers to avoid any series-specific biases that may exist. The modeling approach used is flexible and will allow for yearly updating as new estimates are produced by the source series.

Conclusion
GDP per capita is a necessary tool in population health research, and our development and implementation of a new method has allowed for the most comprehensive known time series to date.
Endogenous MOV10 inhibits the retrotransposition of endogenous retroelements but not the replication of exogenous retroviruses
Authors: Arjan-Odedra Shetal , Swanson Chad M , Sherer Nathan M , Wolinsky Steven M , Malim Michael H 
Published: July 2012

Abstract

Background
The identification of cellular factors that regulate the replication of exogenous viruses and endogenous mobile elements provides fundamental understanding of host-pathogen relationships. MOV10 is a superfamily 1 putative RNA helicase that controls the replication of several RNA viruses and whose homologs are necessary for the repression of endogenous mobile elements. Here, we employ both ectopic expression and gene knockdown approaches to analyse the role of human MOV10 in the replication of a panel of exogenous retroviruses and endogenous retroelements.

Results
MOV10 overexpression substantially decreased the production of infectious retrovirus particles, as well the propagation of LTR and non-LTR endogenous retroelements. Most significantly, RNAi-mediated silencing of endogenous MOV10 enhanced the replication of both LTR and non-LTR endogenous retroelements, but not the production of infectious retrovirus particles demonstrating that natural levels of MOV10 suppress retrotransposition, but have no impact on infection by exogenous retroviruses. Furthermore, functional studies showed that MOV10 is not necessary for miRNA or siRNA-mediated mRNA silencing.

Conclusions
We have identified novel specificity for human MOV10 in the control of retroelement replication and hypothesise that MOV10 may be a component of a cellular pathway or process that selectively regulates the replication of endogenous retroelements in somatic cells.
Effect of influenza vaccines against mismatched strains: a systematic review protocol
Authors: Tricco Andrea C , Chit Ayman , Hallett David , Soobiah Charlene , Meier Genevieve , Chen Maggie , Tashkandi Mariam , Bauch Chris , Loeb Mark 
Published: July 2012

Abstract

Background
Influenza vaccines are most effective when the antigens in the vaccine match those of circulating influenza strains. The extent to which the vaccine is protective when circulating strains differ from vaccine antigens, or are mismatched, is uncertain. We propose to systematically review the cross-protection offered by influenza vaccines against circulating influenza A or B viruses that are not antigenically well-matched to vaccine strains.

Methods/Design
This is a protocol for a systematic review and meta-analysis. Placebo-controlled randomized clinical trials (RCTs) reporting laboratory-confirmed influenza among healthy participants vaccinated with antigens of influenza strains that differed from those circulating will be included. The primary outcome is the incidence of laboratory-confirmed influenza (polymerase chain reaction (PCR) or viral culture). The secondary outcome is the incidence of laboratory-confirmed influenza through antibody assay (a less sensitive test than PCR or viral culture) alone or combined with PCR, and/ or viral culture. The review will be limited to RCTs written in English.
We will search MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, previous influenza reviews, and the reference lists of included studies to identify potentially relevant RCTs. Two independent reviewers will conduct all levels of screening, data abstraction, and quality appraisal (using the Cochrane risk of bias tool).
If appropriate, random effects meta-analysis of vaccine efficacy will be conducted in SAS (version 9.2) by calculating the relative risk. Vaccine efficacy will be calculated using the following formula: (1 - relative risk × 100). The results will be analyzed by type of vaccine (live attenuated, trivalent inactivated, or other). Subgroup analysis will include the effects of age (children, adults, older participants), and influenza A versus influenza B on the results. For influenza B we will also consider variable degrees of antigenic mismatch (lineage and drift mismatch).

Discussion
Our results can be used by researchers and policy-makers to help predict the efficacy of influenza vaccines during mismatched influenza seasons. Furthermore, the review will be of interest to patients and clinicians to determine whether to get immunized or support immunization for a particular influenza season.
Effects of operator parameters, anions and cations on the degradation of AY99 in an aqueous solution using Fenton’s reagent. Optimization and kinetics study
Authors: Bouasla Chafia , Ismail Fadhel , Samar Mohamed El-Hadi 
Published: July 2012

Abstract
In the present work, the decolourization of azo dye Acid Yellow 99 (AY99) in an aqueous solution by Fenton oxidation process was investigated. The results indicated that the initial pH, the nature of the acid to adjust pH, the temperature and the initial concentrations of the Fenton’s reagent FeSO4 of H2O2 and of the AY99 played an important role on the dye decolourization. It was found that under optimum conditions, which have been determined to be pH = 3, [H2O2]0 = 1.8 mmol/L, [Fe2+]0 = 0.09 mmol/L, [AY]0 = 0.06 mmol/L and T = 30°C, efficiency of degradation obtained after 40 min of reaction was about 95%. The decolourization of AY99 by the Fenton process followed the second-order reaction kinetics. The empirical kinetic equation for AY99 decolourization under the conditions of 0.03 to 0.15 mmol/L of Fe2+, 0.9 to 1.8 mmol/L of H2O2, 0.03 to 0.15 mmol/L of Acid Yellow and pH = 3 was found to follow the relation:

K = 6.39 × 107 [AY] −2.8[H2O2]2.29[FeSO4]0.837 exp (−7021.3/T).
The decolourization efficiency Ef (in percent) was 88.36%, 87.93%, 85.98% and 39.61% in the presence of H2SO4, HNO3, HCl and H3PO4 acids, respectively. We can deduce that H2SO4, HNO3 and HCl acids lead almost to the same efficiency (Ef), but in the presence of H3PO4, it is too low:
Ef (H2SO4) ~ Ef (HNO3) > Ef (HCl) > > Ef (H3PO4).
Effects of additives such as inorganic salts (sodium chloride, calcium chloride, sodium sulphate and calcium sulphate) and cations (sodium sulphate, calcium sulphate, copper sulphate, manganese sulphate and magnesium sulphate) on the efficiency (Ef) and on the rate constant (k
2) of AY99 degradation were also studied under optimum conditions.
Ef (Na2SO4) > Ef (CaSO4) > Ef (NaCl) > Ef (CaCl2)

k
2 (CaCl2) < k
2 (NaCl) < k
2 (CaSO4) < k
2 (Na2SO4)
Ef (ZnSO4) > Ef (MgSO4) > Ef (Na2SO4) > Ef (CaSO4) > Ef (CuSO4) > Ef (MnSO4)

k
2 (Na2SO4) < k
2 (MnSO4) < k
2 (CuSO4) < k
2 (CaSO4) < k
2 (ZnSO4) < k
2 (MgSO4).
The presence of anions and cations in the aqueous solution decreases the decolourization efficiency and the rate constant of the degradation of AY99. This inhibition may be due to a complexation and a radical scavenging.
High-throughput mammographic-density measurement: a tool for risk prediction of breast cancer
Authors: Li Jingmei , Szekely Laszlo , Eriksson Louise , Heddson Boel , Sundbom Ann , Czene Kamila , Hall Per , Humphreys Keith 
Published: July 2012

Abstract
Introduction
Mammographic density (MD) is a strong, independent risk factor for breast cancer, but measuring MD is time consuming and reader dependent. Objective MD measurement in a high-throughput fashion would enable its wider use as a biomarker for breast cancer. We use a public domain image-processing software for the fully automated analysis of MD and penalized regression to construct a measure that mimics a well-established semiautomated measure (Cumulus). We also describe measures that incorporate additional features of mammographic images for improving the risk associations of MD and breast cancer risk.

Methods
We randomly partitioned our dataset into a training set for model building (733 cases, 748 controls) and a test set for model assessment (765 cases, 747 controls). The Pearson product-moment correlation coefficient (r) was used to compare the MD measurements by Cumulus and our automated measure, which mimics Cumulus. The likelihood ratio test was used to validate the performance of logistic regression models for breast cancer risk, which included our measure capturing additional information in mammographic images.

Results
We observed a high correlation between the Cumulus measure and our measure mimicking Cumulus (r = 0.884; 95% CI, 0.872 to 0.894) in an external test set. Adding a variable, which includes extra information to percentage density, significantly improved the fit of the logistic regression model of breast cancer risk (P = 0.0002).

Conclusions
Our results demonstrate the potential to facilitate the integration of mammographic density measurements into large-scale research studies and subsequently into clinical practice.
Removal of U(VI) from aqueous solutions by the nano-iron oxyhydroxides
Authors: Sun Y. B. , Yang Shitong , Sheng G. D. , Wang Q. , Guo Z. Q. , Wang X. K. 
Published: July 2012

Abstract
The nano-iron oxyhydroxides (α- and γ-FeOOH) were synthesized by oxidation of the various raw materials (FeSO4 and FeCl2) as iron precursors under alkaline conditions. Morphologies of nano-iron oxyhydroxides were characterized by high resolution transmission electron microscope (HRTEM), X-ray powder diffraction (XRD) and specific surface area (SSA), respectively. The removal of U(VI) from aqueous solution by nano-iron oxyhydroxides was also investigated as a function of contact time, U(VI) concentration, pH, ionic strength and temperature under ambient conditions. The occurrence of needle-like shape of nano-goethite and rod-like shape of nano- lepidocrocite were attributed to oxidization of Fe2+ under different conditions in terms of XRD analysis and HRTEM images. The sorption results indicated that the removal of U(VI) strongly depended on pH and were independent of ionic strength. Langmuir model was employed to model the sorption isotherms of U(VI) at three various temperatures of 293, 313 and 333 K. The thermodynamic parameters (Δ Hº, Δ Sº and Δ Gº) computed from the temperature showed that sorption process of U(VI) on nano-iron oxyhydroxides was endothermic and spontaneous. The mechanism of U(VI) sorption on nano-iron oxyhydroxides was assumed to outer-sphere surface complexation at low pH (pH < 5.0) and at low ionic strength conditions (IS = 0.01 M NaClO4), whereas the uptake of U(VI) was dominated by surface precipitation at high pH conditions. Thereby nano-iron oxyhydroxides can be used as an efficient backfill materials for the in situ disposal of U(VI)-bearing contaminated groundwater.
Spectroscopic investigations of Np(V/VI) redox speciation in hyperalkaline TMA-(OH, Cl) solutions
Authors: Gaona Xavier , Tits Jan , Dardenne Kathy , Liu Xiaolan , Rothe Jörg , Denecke Melissa A. , Wieland Erich , Altmaier Marcus 
Published: July 2012

Abstract
The redox chemistry of Np(V/VI) was investigated in ∼0.6 M tetramethylammonium hydroxide/chloride (TMA-(OH, Cl)) solutions with 9 ≤ −log [H+] ≤ 13.5. Redox conditions were defined by the absence or presence of ClO− as oxidizing agent (Na-salt, 5 × 10−3 M and 5 × 10−2 M). The high total Np concentration ([Np]tot ∼ 2 × 10−3 M) led to the precipitation of solid phases in some of the samples. The carbonate concentration (as impurity of TMA-OH) was 2–3 × 10−3 M.
UV-vis/NIR spectra obtained from the supernatant in TMA-(OH, Cl) solutions and absence of ClO− showed clear Np(V) features, identified as NpO2
+, NpO2CO3
− and (NpO2)
x
(CO3)
y
(OH)
z

x−2y−z
. No NIR features were observed within 800 nm ≤ λ ≤ 1300 nm for samples with ClO−. XANES edge energies and features of these samples confirmed the predominance of Np(V) in the absence of ClO− and Np(VI) in the presence of ClO−, by comparison to XANES reference spectra of Np(III/IV/V/VI) prepared within the present work by in-situ electrolysis. A similar Np redox distribution was observed for the solid phases based on XANES and EXAFS measurements. EXAFS spectra indicative of NpVO2OH(s) and NpVIO3· xH2O(s) were obtained for samples in absence and presence of ClO−, respectively. The formation of a Na-Np(VI) phase in 5 × 10−2 M ClO− and −log [H+] ∼ 12 was also indicated from the EXAFS, chemical analysis and SEM-EDS.
These results indicate that Np(VI) aqueous species and solid compounds prevail far below the oxidation border of water in alkaline solutions and also far below the E
H border calculated with the current NEA data selection [1]. These observations are further supported by correlations of literature thermodynamic data for actinides (U, Np, Pu and Am), which predict the formation of NpO2(OH)3
− and NpO2(OH)4
2− aqueous species with stability constants (log *
βº1,3 and log *
βº1,4) similar to those available for U(VI).