bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mineralogy and geochemistry of hydrothermal kaolins from the Adelita mine, Patagonia (Argentina); relation to other mineralization in the area
Authors: Grecco L. E. , Marfil S. A. , Maiza P. J. 
Published: March 2012

AbstractThe kaolin deposit at the Adelita mine, located in the province of Rí;o Negro (Patagonia, Argentina), was studied. Petrographic studies on thin sections and chemical analyses of major, minor and trace elements on bulk samples were carried out. The kaolin content of the rock ranges from 31% to 65%. The mineralogy of the working front, which is about 45 m thick, varies from the upper zone, where the rock is strongly silicified, stained with iron oxides and carbonated, grading downwards to a kaolinized zone, with a quartz-kaolinite-dickite assemblage with relict lithic particles and a smaller amount of iron oxides, and ending in the deepest zone where dickite, alunite, diaspore, quartz and scarce associated kaolinite occur.The kaolin mineralogy was determined by SEM, XRD, DTA-TG, IR and δ18O and δD isotope analyses. The S, Ba and Sr contents are enriched during hydrothermal alteration, whereas Cr, Nb, Ti and lanthanide elements are concentrated mainly during weathering. The (Ba+Sr) concentrations in the samples studied vary between 600 and 6000 ppm and (Ce+Y+La) between 2 and 150 ppm; (Cr+Nb) remains constant for all the samples, whereas (TiO2+Fe2O3) is below 0.3%. In the hypogene deposits P2O5 is also more abundant and increases with the degree of alteration. Chondritenormalized rare earth element diagram shows a marked enrichment in LREE relative to HREE, with negative europium anomalies and D18O values range between 3.8‰ and 7.7‰ and δD between –123‰ and –103‰, suggesting that kaolin formed from the hydrothermal alteration of rhyolitic tuffs.
Characterization of natural- and organobentonite by XRD, SEM, FT-IR and thermal analysis techniques and its adsorption behaviour in aqueous solutions
Authors: Ikhtiyarova G. A. , Özcan A. S. , Gök Ö. , Özcan A. 
Published: March 2012

AbstractIn this study, natural bentonite was modified with hexadecyltrimethylammonium (HDTMA) bromide to obtain organobentonite (HDTMA-bentonite). Bentonite and HDTMA-bentonite were then characterized using XRD, XRF, SEM, FT-IR, thermogravimetric (TG) analysis, elemental analysis and Brunauer-Emmett-Teller (BET) surface area techniques. The HDTMA+ cation was found to be located on the surface and enters the interlayer spaces of smectite according to the XRD and SEM results. FT-IR spectra indicated the existence of HDTMA functional groups on the bentonite surface. The BET surface area significantly decreased after the modification due to the coverage of the pores of natural bentonite. After the characterization, the adsorption of a textile dye, Reactive Blue 19 (RB19), onto bentonite and HDTMA-bentonite was investigated. The maximum adsorption capacity of HDTMA-bentonite for RB19 was 502 mg g-1 at 20°C. The adsorption process followed a pseudo-second-order kinetic model and it was exothermic and physical in nature.
Mineralogical characteristics and geological significance of Albian (Early Cretaceous) glauconite in Zanda, southwestern Tibet, China
Authors: Li Xiang , Cai Yuanfeng , Hu Xiumian , Huang Zhicheng , Wang Jiangang 
Published: March 2012

AbstractEarly Cretaceous glauconite from the Xiala section, southwestern Tibet, China, was investigated by petrographic microscopy and scanning electron microscopy (SEM), X-ray diffractometry (XRD), Fourier transform infrared (FTIR) spectroscopy, and electron probe microanalysis (EPMA). The investigations revealed that the glauconite in both sandstones and limestone is highly evolved. The glauconite in sandstone is autochthonous, but in limestone it may be derived from the underlying glauconitic sandstone. Based on analyses of the depositional environments and comparisons of glauconite-bearing strata in Zanda with sequences in adjacent areas, we conclude that the glauconitization at Zanda was probably associated with rising sea levels during the Late Albian, which represent the final separation of the Indian continent from the Australian-Antarctic continent. After the separation of the Indian continent from the Australian-Antarctic continent, cooling of the Indian continent resulted in subsidence and northward subduction of the Indian plate. A gradually rising sea level in Zanda, located along the northern margin of the Indian continent, was the cause of the low sedimentation rate. Continued transgression resulted in the occurrence of the highly evolved glauconite in this area.
An unusually thermally stable magnetite from a niobium mine in Brazil
Authors: Silva A. C. , Pereira M. C. , Oliveira L. C. A. , Cavalcante L. C. D. , Fabris J. D. , Murad E. 
Published: March 2012

AbstractMagnetite-rich waste from a niobium mine near Araxá, State of Minas Gerais, Brazil, was heated to 500°C and 1000°C under an O2atmosphere. The original waste and its oxidized products were characterized by energy-dispersive X-ray spectroscopy (EDS), X-ray powder diffraction (XRD), room-temperature57Fe Mössbauer spectroscopy, thermogravimetric analysis (TG) and temperature-programmed reduction (TPR).Semiquantitative analyses by EDS and quantitative chemical analyses showed the waste to be constituted primarily of Fe with minor amounts of Ti, Ba, Al, Si, Nb, Mn, S and P. Mössbauer and XRD showed the waste to consist predominantly of magnetite and hematite. The magnetite content decreases when the temperature increases due to its direct conversion to hematite. However, at 500°C only 10 wt.% of original magnetite was converted to hematite, confirming the high stability of this magnetite, which could still be detected at 1000°C. The TG profile shows no significant weight gain on heating, indicating a high stability of the magnetite. The TPR profiles show that the hematite in the waste is sintered after treatment at 1000°C and the reduction peaks are consequently shifted to higher temperatures. This high thermal stability is attributed to a moderate isomorphous replacement of Fe by other cations present in the Nb mining waste.
Removal of Mg from spring water using natural clinoptilolite
Authors: Tomić S. , Rajić N. , Hrenović J. , Povrenović D. 
Published: March 2012

AbstractNatural zeolitic tuff from Brus (Serbia) consisting mostly of clinoptilolite (about 90%) has been investigated for the reduction of the Mg concentration in spring water. The sorption capacity of the zeolite is relatively low (about 2.5 mg Mg g-1for the initial concentration of 100 mg Mg dm-3). The zeolitic tuff removes Mg from water solutions by ion exchange, which has been demonstrated by energy dispersive X-ray analysis (EDS). The extent of ion exchange was influenced by the pH and the initial Mg concentration. Kinetic studies revealed that Lagergen's pseudo-second order model was followed. Intra-particle diffusion of Mg2+influenced the ion exchange, but it is not the rate-limiting step. Rather than having to dispose of the Mg-loaded (waste) zeolite, a possible application was tested. Addition to a wastewater with a low concentration of Mg showed that it could successfully make up for the lack of Mg micronutrient and, accordingly, enabled the growth of phosphate-accumulating bacteriaA. Junii, increasing the amount of phosphate removed from the wastewater.
Testes-specific hemoglobins in Drosophilaevolved by a combination of sub- and neofunctionalization after gene duplication
Authors: Gleixner Eva , Herlyn Holger , Zimmerling Stefan , Burmester Thorsten , Hankeln Thomas 
Published: March 2012

Abstract

Background
For a long time the presence of respiratory proteins in most insects has been considered unnecessary. However, in recent years it has become evident that globins belong to the standard repertoire of the insect genome. Like most other insect globins, the glob1 gene of Drosophila melanogaster displays a conserved expression pattern in the tracheae, the fat body and the Malpighian tubules.

Results
Here we show that the recently discovered D. melanogaster globin genes glob2 and glob3 both display an unusual male-specific expression in the reproductive tract during spermatogenesis. Both paralogs are transcribed at equivalent mRNA levels and largely overlap in their cellular expression patterns during spermatogenesis. Phylogenetic analyses showed that glob2 and glob3 reflect a gene duplication event that occurred in the ancestor of the Sophophora subgenus at least 40 million years ago. Therefore, flies of the Drosophila subgenus harbor only one glob2/3-like gene.

Conclusions
Phylogenetic and sequence analyses indicate an evolution of the glob2 and glob3 duplicates by a combination of sub- and neofunctionalization. Considering their restricted, testes-specific expression, an involvement of both globins in alleviating oxidative stress during spermatogenesis is conceivable.
Quantitative molecular assessment of chimerism across tissues in marmosets and tamarins
Authors: Sweeney Carolyn G , Curran Elizabeth , Westmoreland Susan V , Mansfield Keith G , Vallender Eric J 
Published: March 2012

Abstract

Background
Marmosets are playing an increasingly large and important role in biomedical research. They share genetic, anatomical, and physiological similarities with humans and other primate model species, but their smaller sizes, reproductive efficiency, and amenability to genetic manipulation offer an added practicality. While their unique biology can be exploited to provide insights into disease and function, it is also important that researchers are aware of the differences that exist between marmosets and other species. The New World monkey family Callitrichidae, containing both marmoset and tamarin species, typically produces dizygotic twins that show chimerism in the blood and other cells from the hematopoietic lineage. Recently, a study extended these findings to identify chimerism in many tissues, including somatic tissues from other lineages and germ cells. This has raised the intriguing possibility that chimerism may play an increasingly pervasive role in marmoset biology, ranging from natural behavioral implications to increased variability and complexity in biomedical studies.

Results
Using a quantitative PCR based methodology, Y-chromosomes can be reliably detected in the females with male fraternal twins allowing for a relative quantification of chimerism levels between individuals and tissues. With this approach in common marmosets (Callithrix jacchus) and cotton-top tamarins (Saguinus oedipus), chimerism was detected across a broad array of tissues. Chimerism levels were significantly higher in tissues primarily derived from the hematopoietic lineage, while they were lower, though still detectable, in tissues with other origins. Interestingly, animals with a characteristic marmoset wasting disease show higher levels of chimerism in those tissues affected. Fibroblast cell lines from chimeric individuals, however, are not found to be chimeric themselves.

Conclusion
Taken together, the levels of chimerism in tissues of different origins coupled with other lines of evidence suggest that indeed only hematopoietic cell lineages are chimeric in callitrichids. The chimerism detected in other tissues is likely the result of blood or lymphocytic infiltration. Using molecular methods to detect chimerism in a tissue sample seems to have allowed a substantial increase in the ability to detect these minor cell populations.
Burden of community-acquired and nosocomial rotavirus gastroenteritis in the pediatric population of Western Europe: a scoping review
Authors: Ogilvie Isla , Khoury Hanane , Goetghebeur Mireille M , El Khoury Antoine C , Giaquinto Carlo 
Published: March 2012

Abstract

Background
Rotavirus affects 95% of children worldwide by age 5 years and is the leading cause of severe dehydrating diarrhea. The objective of this review was to estimate the burden of rotavirus gastroenteritis (RVGE) in the Western European pediatric population.

Methods
A comprehensive literature search (1999-2010) was conducted in PubMed and other sources (CDC; WHO, others). Data on the epidemiology and burden of RVGE among children < 5 years-old in Western Europe --including hospital-acquired disease--were extracted.

Results
76 studies from 16 countries were identified. The mean percentage of acute gastroenteritis (AGE) cases caused by rotavirus ranged from 25.3%-63.5% in children < 5 years of age, peaking during winter. Incidence rates of RVGE ranged from 1.33-4.96 cases/100 person- years. Hospitalization rates for RVGE ranged from 7% to 81% among infected children, depending on the country. Nosocomial RVGE accounted for 47%-69% of all hospital-acquired AGE and prolonged hospital stays by 4-12 days. Each year, RVGE incurred $0.54- $53.6 million in direct medical costs and $1.7-$22.4 million in indirect costs in the 16 countries studied. Full serotyping data was available for 8 countries. G1P[8], G2P[4], G9P[8], and G3P[8] were the most prevalent serotypes (cumulative frequency: 57.2%- 98.7%). Serotype distribution in nosocomial RVGE was similar.

Conclusions
This review confirms that RVGE is a common disease associated with significant morbidity and costs across Western Europe. A vaccine protecting against multiple serotypes may decrease the epidemiological and cost burden of RVGE in Western Europe.
Multimorbidity prevalence and patterns across socioeconomic determinants: a cross-sectional survey
Authors: Agborsangaya Calypse B , Lau Darren , Lahtinen Markus , Cooke Tim , Johnson Jeffrey A 
Published: March 2012

Abstract

Background
Studies on the prevalence of multimorbidity, defined as having two or more chronic conditions, have predominantly focused on the elderly. We estimated the prevalence and specific patterns of multimorbidity across different adult age groups. Furthermore, we examined the associations of multimorbidity with socio-demographic factors.

Methods
Using data from the Health Quality Council of Alberta (HQCA) 2010 Patient Experience Survey, the prevalence of self reported multimorbidity was assessed by telephone interview among a sample of 5010 adults (18 years and over) from the general population. Logistic regression analyses were performed to determine the association between a range of socio-demographic factors and multimorbidity.

Results
The overall age- and sex-standardized prevalence of multimorbidity was 19.0% in the surveyed general population. Of those with multimorbidity, 70.2% were aged less than 65 years. The most common pairing of chronic conditions was chronic pain and arthritis. Age, sex, income and family structure were independently associated with multimorbidity.

Conclusions
Multimorbidity is a common occurrence in the general adult population, and is not limited to the elderly. Future prevention programs and practice guidelines should take into account the common patterns of multimorbidity.
Effects of a combined strengthening, stretching and functional training program versus usual-care on gait biomechanics and foot function for diabetic neuropathy: a randomized controlled trial
Authors: Sartor Cristina Dallemole , Watari Ricky , Pássaro Anice Campos , Picon Andreja Paley , Hasue Renata Haydée , Sacco Isabel CN 
Published: March 2012

Abstract

Background
Polyneuropathy is a complication of diabetes mellitus that has been very challenging for clinicians. It results in high public health costs and has a huge impact on patients' quality of life. Preventive interventions are still the most important approach to avoid plantar ulceration and amputation, which is the most devastating endpoint of the disease. Some therapeutic interventions improve gait quality, confidence, and quality of life; however, there is no evidence yet of an effective physical therapy treatment for recovering musculoskeletal function and foot rollover during gait that could potentially redistribute plantar pressure and reduce the risk of ulcer formation.

Methods/Design
A randomised, controlled trial, with blind assessment, was designed to study the effect of a physiotherapy intervention on foot rollover during gait, range of motion, muscle strength and function of the foot and ankle, and balance confidence. The main outcome is plantar pressure during foot rollover, and the secondary outcomes are kinetic and kinematic parameters of gait, neuropathy signs and symptoms, foot and ankle range of motion and function, muscle strength, and balance confidence. The intervention is carried out for 12 weeks, twice a week, for 40-60 min each session. The follow-up period is 24 weeks from the baseline condition.

Discussion
Herein, we present a more comprehensive and specific physiotherapy approach for foot and ankle function, by choosing simple tasks, focusing on recovering range of motion, strength, and functionality of the joints most impaired by diabetic polyneuropathy. In addition, this intervention aims to transfer these peripheral gains to the functional and more complex task of foot rollover during gait, in order to reduce risk of ulceration. If it shows any benefit, this protocol can be used in clinical practice and can be indicated as complementary treatment for this disease.

Trial Registration
ClinicalTrials.gov Identifier: NCT01207284
Crystal structures from the Plasmodium peroxiredoxins: new insights into oligomerization and product binding
Authors: Qiu Wei , Dong Aiping , Pizarro Juan C , Botchkarsev Alexei , Min Jinrong , Wernimont Amy K , Hills Tanya , Hui Raymond , Artz Jennifer D 
Published: March 2012

Abstract

Background

Plasmodium falciparum is the protozoan parasite primarily responsible for more than one million malarial deaths, annually, and is developing resistance to current therapies. Throughout its lifespan, the parasite is subjected to oxidative attack, so Plasmodium antioxidant defences are essential for its survival and are targets for disease control.

Results
To further understand the molecular aspects of the Plasmodium redox system, we solved 4 structures of Plasmodium peroxiredoxins (Prx). Our study has confirmed Pv Trx-Px1 to be a hydrogen peroxide (H2O2)-sensitive peroxiredoxin. We have identified and characterized the novel toroid octameric oligomer of Py Trx-Px1, which may be attributed to the interplay of several factors including: (1) the orientation of the conserved surface/buried arginine of the NNLA(I/L)GRS-loop; and (2) the C-terminal tail positioning (also associated with the aforementioned conserved loop) which facilitates the intermolecular hydrogen bond between dimers (in an A-C fashion). In addition, a notable feature of the disulfide bonds in some of the Prx crystal structures is discussed. Finally, insight into the latter stages of the peroxiredoxin reaction coordinate is gained. Our structure of Py Prx6 is not only in the sulfinic acid (RSO2H) form, but it is also with glycerol bound in a way (not previously observed) indicative of product binding.

Conclusions
The structural characterization of Plasmodium peroxiredoxins provided herein provides insight into their oligomerization and product binding which may facilitate the targeting of these antioxidant defences. Although the structural basis for the octameric oligomerization is further understood, the results yield more questions about the biological implications of the peroxiredoxin oligomerization, as multiple toroid configurations are now known. The crystal structure depicting the product bound active site gives insight into the overoxidation of the active site and allows further characterization of the leaving group chemistry.
Do medical student attitudes towards patients with chronic low back pain improve during training? a cross-sectional study
Authors: Morris Hayley , Ryan Cormac , Lauchlan Douglas , Field Max 
Published: March 2012

Abstract

Background
Health care professionals with positive attitudes towards the functional abilities of patients with low back pain are more likely to encourage activity and avoidance of rest as per recommended guidelines. This study investigated whether medical student training fosters positive attitudes towards patients with back pain and their ability to function.

Methods
First (n = 202) and final (n = 146) year medical students at the University of Glasgow completed the Health Care Professionals' Pain and Impairment Relationship Scale (HC-PAIRS) questionnaire. This measures attitudes of clinicians towards the functional ability of patients with back pain. A group of first (n = 62) and final year (n = 61) business students acted as non-health care controls. Attitudes were compared using two-way ANOVA with year of study and discipline of degree as independent variables.

Results
Both year of study [F(1,465) = 39.5, p < 0.01] and discipline of degree [F(1,465) = 43.6, p < 0.01] had significant effects on total HC-PAIRS scores and there was a significant interaction effect [F(1,465) = 9.5, p < 0.01]. Medical students commenced their course with more positive attitudes than non-health care students (65.7 vs. 69.2 respectively; p < 0.01) - lower scores translating into more positive attitudes. In their final year, the difference between the two student groups had widened (56.4 vs. 65.3; p < 0.01).

Conclusions
Undergraduate medical training promotes positive attitudes towards the functional ability of patients with back pain, suggesting that students may be more likely to develop an evidence-based approach to this patient group after qualification. Some adjustments to training may be warranted to encourage a more positive shift in attitudes.
Prevalence of left ventricular diastolic dysfunction in European populations based on cross-validated diagnostic thresholds
Authors: Kloch-Badelek Malgorzata , Kuznetsova Tatiana , Sakiewicz Wojciech , Tikhonoff Valérie , Ryabikov Andrew , González Arantxa , López Begoña , Thijs Lutgarde , Jin Yu , Malyutina Sofia , Stolarz-Skrzypek Katarzyna , Casiglia Edoardo , Díez Javier , Narkiewicz Krzysztof , Kawecka-Jaszcz Kalina , Staessen Jan A ,   the European Project On Genes in Hypertension (EPOGH) Investigators
Published: March 2012

Abstract

Background
Different diagnostic criteria limit comparisons between populations in the prevalence of diastolic left ventricular (LV) dysfunction. We aimed to compare across populations age-specific echocardiographic criteria for diastolic LV dysfunction as well as their correlates and prevalence.

Methods
We measured the E and A peaks of transmitral blood flow by pulsed wave Doppler and the e' and a' peaks of mitral annular velocities by tissue Doppler imaging (TDI) in 2 cohorts randomly recruited in Belgium (n = 782; 51.4% women; mean age, 51.1 years) and in Italy, Poland and Russia (n = 476; 55.7%; 44.5 years).

Results
In stepwise regression, the multivariable-adjusted correlates of the transmitral and TDI diastolic indexes were similar in the 2 cohorts and included sex, age, body mass index, blood pressure and heart rate. Similarly, cut-off limits for the E/A ratio (2.5th percentile) and E/e' ratio (97.5th percentile) in 338 and 185 reference subjects free from cardiovascular risk factors respectively selected from both cohorts were consistent within 0.02 and 0.26 units (median across 5 age groups). The rounded 2.5th percentile of the E/A ratio decreased by ~0.10 per age decade in these apparently healthy subjects. The reference subsample provided age-specific cut-off limits for normal E/A and E/e' ratios. In the 2 cohorts combined, diastolic dysfunction groups 1 (impaired relaxation), 2 (possible elevated LV filling pressure) and 3 (elevated E/e' and abnormally low E/A) encompassed 114 (9.1%), 135 (10.7%), and 40 (3.2%) subjects, respectively.

Conclusions
The age-specific criteria for diastolic LV dysfunction were highly consistent across the study populations with an age-standardized prevalence of 22.4% vs. 25.1%.