bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of angiotensin-converting enzyme gene insertion/deletion polymorphism on steroid resistance in Egyptian children with idiopathic nephrotic syndrome
Authors: Saber-Ayad Maha , Sabry Samar , Abdel-Latif Inas , Nabil Hanaa , El-Azm Soheir Abo , Abdel-Shafy Sanaa 
Published: April 2010

Introduction. The presence of the deletion (D) allele in the angiotensin-converting enzyme (ACE) gene has been reported as a probable genetic risk factor for idiopathic nephrotic syndrome (INS), but its role in determining resistance to steroid therapy remains to be evaluated. Methods. Fifty-one patients were enrolled in the study and received oral steroids. The pattern of response to steroid therapy was determined. A group of 50 healthy adults served as a control group. The genotypes for ACE insertion (I)/D polymorphism were analysed using a PCR-based method. Results. Twenty patients were steroid sensitive (SS) and 31 were non-SS. The presence of hypertension at presentation was significantly related to steroid unresponsiveness. Among the SS group, the frequencies of the II, ID, and DD genotypes of the ACE gene were 20% (n=4), 65% (n=13), and 15% (n=3), respectively, while the frequencies among the non-SS group were 19.4% (n=6), 74.2% (n=23), and 6.5% (n=2), respectively. The differences between the two groups were not statistically significant (Chi square=0.59). Conclusion. The current study on Egyptian children with INS reveals no association between the ACE gene I/D polymorphism and clinical parameters, histological findings, and steroid resistance.
Review: Plasma renin and the incidence of cardiovascular disease
Authors: Meade Tom 
Published: April 2010

Whether renin is involved in the onset of coronary heart disease (CHD) remains unclear. A case-control study in 1972, suggesting a causal association between renin and CHD, has now been followed by three prospective studies. One was based on 1,717 hypertensive subjects in a Work-Site Program in New York. The main results showed an increased risk of CHD the higher the renin level. A second study in occupational groups in North West London, UK, recruited 803 white men not selected according to blood pressure, and found no association. A possible exception was in the minority of those with similar blood pressure levels to participants in the Work-Site Program, in whom the incidence of CHD was higher according to the renin level, but not significantly so. The third study was in Framingham Offspring and included 3,532 participants also not selected according to blood pressure. As in the UK study, there was no clear association between renin and risk of CHD in all participants, or in this study in those with raised blood pressure. The authors considered their results consistent with those of the UK study in finding “no association of renin with overall risk of CHD”. Besides the three epidemiological studies, dealing explicitly with renin, other studies in which it has been one of several variables considered have also not found convincing evidence of its involvement in CHD. There is, therefore, little support for the hypothesis that high renin levels increase the risk of CHD, with the possible but uncertain exception of those with raised blood pressure.
Effects of pH, Ca- and SO4-concentration on surface charge and colloidal stability of goethite and hematite – consequences for the adsorption of anionic organic substances
Authors: Walsch J. , Dultz S. 
Published: April 2010

AbstractSoil solution chemistry, especially pH and the presence of multivalent ions, affects the surface charge (SC) of Fe oxides and accordingly colloidal stability and sorption properties. The SC of synthetic goethite and hematite was quantified in the presence of different electrolytes (NaCl, CaCl2, Na2SO4and CaSO4) by combining the streaming potential with polyelectrolyte titration. The point of zero charge (PZC) for goethite was observed at pH 8.2 and the stability field around the PZC, where colloids are flocculated, is more extended (±1 pH unit) than that of hematite with a PZC at pH 7.1 (±0.5 pH unit). The SC decreases with increasing SO4concentration, indicating adsorption of SO4on the oxide, whereas the presence of Ca increases the SC. At pH 4, the addition of 0.1 mmol l–1Na2SO4induced a decrease in SC from 1.5 to 0.380 μmolcm–2for goethite and from 0.85 to 0.42 μmolcm–2for hematite. In a suspension with 0.1 mmol l–1Na2SO4, the number of colloids is already reduced, and both oxides flocculate rapidly and completely at >0.5 mmol l–1Na2SO4. While the addition of SO4did not affect charge titrations with the cationic polyelectrolyte, the anionic polyelectrolyte formed complexes with Ca, resulting in an overestimation of positive SC. The electrolyte CaSO4is most efficient at keeping goethite and hematite in the pH range 4–10 in the flocculated state. Besides pH, the presence of multivalent ions should also be considered when predicting colloid mediated transport and adsorption properties of anionic substances by Fe oxides in soil systems.
Modelling the process of kaolinite leaching from a copper mine flotation waste
Authors: Djurić I. , Mihajlović I. , Bogdanović D. , Živković Ž. 
Published: April 2010

AbstractThis paper presents the results of acidic leaching of kaolinite from the flotation waste of the RTB Bor copper mine, Serbia. The kaolinitic concentrate from the flotation waste contains 32% Al2O3. Kinetic investigations were conducted on the leaching of kaolinite roasted at 750°C for 60 min under air using H2SO4, HNO3 and HCl. Activation energies for the process were 74, 63 and 63.2 kJ mol–1 for sulphuric, nitric and hydrochloric acids, respectively. The kinetic function D3: [1 – (1 – α)1/3]2 = kt was chosen to describe the fractional conversion dependence on time and temperature. This enabled effective management of the leaching process to be carried out.
Use ofTmaxas a thermal maturity indicator in orogenic successions and comparison with clay mineral evolution
Authors: Dellisanti F. , Pini G. A. , Baudin F. 
Published: April 2010

AbstractThe relationship between three parameters, theTmaxgiven by Rock-Eval pyrolysis, the illite content in illite-smectite mixed layers (I-S) and the Ku¨bler Index (KI) has been investigated in the Cretaceous–Neogene, sedimentary syn-orogenic successions in the Northern Apennines (Italy). A strong relationship was found between maturity stages of kerogen, illite content in I-S and KI. The oil formation zone for continental organic matter (Type III), delimited byTmaxbetween 434 and 465ºC, corresponded to rocks with short-range ordering R1, I-S with illite content between 60 and 85% and KI values in the range 0.85–0.65 (ºΔ2θ). Over-mature rocks were characterized byTmax>465ºC, a long-range ordered I-S with an illite content >85% and KI in the range 0.65–0.45 (ºΔ2θ). The relationship permits use of both mineralogical parameters andTmaxto estimate palaeotemperatures in sedimentary successions and it can be exploited in hydrocarbon research to evaluate the petroleum potential.
Acid and aluminium modification of sepiolite and its application in FCC catalysis
Authors: Zheng Shu-Qin , Han Yong , Huang Xiao-Hong , Dai Ya-Li , Qian Dong , Zhang Jian-Ce , Ren Shao 
Published: April 2010

AbstractThe effects of acid and Al concentration, type of Al salt, treatment temperature and time of removal of Mg from sepiolite have been investigated, as has the use of modified sepiolite as an active fluid catalytic cracking (FCC) matrix. The samples were characterized by N2 adsorption and X-ray diffraction. Mg removal from sepiolite increased with increasing acid and Al ion concentration, treatment time and temperature. The temperature had the greatest impact on Mg removal. After acid and Al modification, 29% of the Mg was removed. When using the modified sepiolites as active matrices in FCC catalysts, the specific surface area, pore volume and mesoporous pore volume of the catalysts increased and they exhibited excellent performance in resisting the effects of heavy-metals as a result of the introduction of Mg oxide from the modified sepiolite.
Determination of soil aggregate disintegration dynamics using laser diffraction
Authors: Bieganowski A. , Ryżak M. , Witkowska-Walczak B. 
Published: April 2010

AbstractA new practical and precise method for determining soil aggregate stability is described. Four air-dry aggregate fractions (<0.25, 0.25–0.5, 0.5–1.0 and 1.0–2.0 mm) were added to thoroughly stirred water in a Mastersizer 2000 laser diffractometer. The suspension obtained was passed directly through the measuring system. The dynamics of median (equivalent diameterd50) particle-size distribution decrease (interpolated with a logarithmic function) was assumed to be the measure of soil aggregate stability. In order to show the applicability of the new method, the results obtained (for selected and diverse soils) were compared with those from the wet sieving standard method. The main conclusion is that the proposed method is convenient and can be successfully used for the estimation of soil aggregate stability. Moreover, it has wider application because standard sieving methods are restricted to aggregates >0.25 mm whereas, with the use of the laser diffraction method, smaller aggregates can be measured. The energy delivered to the aggregates in the process of aggregate disintegration is more reproducible in the method described here. The method also provides an opportunity to verify that the soil aggregates are completely destroyed (lack of the changes of the median value shows the end of soil aggregate disintegration).
Palaeoenvironmental approach to the geology, mineralogy and geochemistry of an Early Miocene alluvial-fan to cyclic shallow-lacustrine depositional system in the Aktoprak Basin (central Anatolia), Turkey
Authors: Gürel A. , Kadir S. 
Published: April 2010

AbstractThe Aktoprak Basin, Turkey, provides important clues regarding regional palaeoclimatic changes which have not so far been elucidated. The purpose of the present study is to fill this gap using mineralogical, geochemical and isotopic characterization of cyclic sedimentation within Neogene sedimentary units. Early Miocene alluvial-fan to cyclic shallow-lacustrine sediments of the Aktoprak Basin consist of conglomerate, sandstone, mudstone, marl, limestone and palaeosol. The increasingly fine upward grain size and bed thicknesses suggest that the alluvial fan was fed by an ephemeral braided river. The cyclic sandflat–mudflat–shallow-lake succession is predominantly composed of small-scale sandstone-mudstone beds. Sandstone intervals in the sedimentary cycles are interpreted to be a result of sedimentation from shallow, ephemeral braided-river channels, the deposits having evolved under water-saturated conditions in response to climate changes. The mudstone intervals are interpreted as having been laid down via sedimentation during distal sheet floods which developed either under sub-aerial exposure or in a water-saturated environment. Palaeocurrent measurements indicate that the general transport direction in the Early Miocene was from east to west. The lacustrine sediments of the Aktoprak Basin consist of calcite + quartz + feldspar + serpentine coexisting mainly with smectite ± palygorskite ± illite ± chlorite. Illite and chlorite are either detrital, having originated from basement units, or the illite formed authigenically from smectite. Calcite and clay appear as cement-building conglomerate, sandstone and mudstone. The clay content decreases with increasing calcite and the presence of an inverse relationship between CaO and other oxides may correspond to an inverse relationship between calcite and other minerals. Furthermore, Al2O3, Fe2O3, TiO2, MgO, Ni, Co, Cu, Sr, Ba and Zr values in the smectite-bearing mudstone and sandstone are consistent with the chemical compositions of rocks in the surrounding area, mainly ophiolitic and volcanogenic associations. Micromorphologically, the development of smectite as a cement on leached feldspar, the occurrence of palygorskite fibres as bridges between crystals and rock fragments, as well as the presence of ‘edging’ smectite flakes suggest an authigenic origin. Field observations, mineralogy, geochemistry and the results of δ18O and δ13C isotopic determinations reveal that periodic palaeoclimatic changes were controlled by alternating wet and dry periods that resulted in a relative upward decrease in precipitation of authigenic smectite ± palygorskite within the sections, under the influence of geochemical and pH fluctuations in meteoric water within the shallow-lake environment.
Bentonite from Porto Santo Island, Madeira archipelago: surface properties studied by inverse gas chromatography
Authors: Cordeiro N. , Silva J. , Gomes C. , Rocha F. 
Published: April 2010

AbstractThe present paper shows the importance of Inverse Gas Chromatography (IGC) for the determination of the surface properties of bentonites. These properties are dispersive surface energy, acid-base properties, surface heterogeneity, sorption isotherms, BET surface areas and heat of sorption, using different probe molecules. IGC can contribute to the interpretation, prediction and optimization of the studied materials' properties. The paper focuses on two distinctive bentonite samples from Porto Santo Island, Madeira archipelago. In view of their potential value, achieved through their incorporation in products for dermopharmacy and dermocosmetics, particle size and particle surface properties are of fundamental importance.
Corrensite and chlorite-rich Chl-S mixed layers in sandstones from the ‘Macigno’ Formation (northwestern Tuscany, Italy)
Authors: Leoni L. , Lezzerini M. , Battaglia S. , Cavalcante F. 
Published: April 2010

AbstractCorrensite and chlorite-rich chlorite-smectite (Chl-S) mixed-layers occurring in the Macigno Formation of northwestern Tuscany were investigated by XRPD/SEM techniques. The samples from the Macigno outcrops were affected by metamorphism corresponding to the high-diagenesis/low-anchizone transition boundary. The basal spacing of corrensite measured from 00lreflections on EG–Mg2+-saturated samples ranges from 30.97 to 31.18 Å with a coefficient of variation (CV) of 0.46–0.77%, consistent with the rational pattern of a 1:1 Chl-S periodic stacking sequence. X-ray patterns of heated K+-saturated specimens reveal the presence of two types of corrensite, probably with different interlayer charges on their respective smectite-like layers. The chlorite-rich Chl-S mixed layers coexisting with corrensite consist of R2 chlorite (0.70–0.75)/S and chlorite (0.90)/S with long-range orderingR⩾ 1. SEM observations show that corrensite and chlorite-rich Chl-S mixed-layers are closely mixed on a sub-micron scale. Some grains of corrensite and chlorite-rich Chl-S mixed-layers include zones (2–10 μm) of chlorite composition, as shown by microprobe analyses.
The structure of charoite, (K,Sr,Ba,Mn)15–16(Ca,Na)32[(Si70(O,OH)180)](OH,F)4.0.nH2O, solved by conventional and automated electron diffraction
Authors: Rozhdestvenskaya I. , Mugnaioli E. , Czank M. , Depmeier W. , Kolb U. , Reinholdt A. , Weirich T. 
Published: April 2010

AbstractCharoite, ideally (K,Sr,Ba,Mn)15–16(Ca,Na)32[(Si70(O,OH)180)](OH,F)4.0·nH2O, a rare mineral from the Murun massif in Yakutiya, Russia, was studied using high-resolution transmission electron microscopy, selected-area electron diffraction, X-ray spectroscopy, precession electron diffraction and the newly developed technique of automated electron-diffraction tomography. The structure of charoite (a= 31.96(6) Å,b= 19.64(4) Å,c= 7.09(1) Å, β = 90.0(1)°,V= 4450(24) Å3, space groupP21/m) was solvedab initioby direct methods from 2878 unique observed reflections and refined toR1/wR2= 0.17/0.21. The structure can be visualized as being composed of three different dreier silicate chains: a double dreier chain, [Si6O17]10–; a tubular loop-branched dreier triple chain, [Si12O30]12–; and a tubular hybrid dreier quadruple chain, [Si17O43]18–. The silicate chains occur between ribbons of edge-sharing Ca and Na-octahedra. The chains of tetrahedra and the ribbons of octahedra extend parallel to thezaxis. K+, Ba2+, Sr2+, Mn2+and H2O molecules lie inside tubes and channels of the structure. On the basis of microprobe analyses and occupancy refinement of the cation sites, the crystal chemical formula of this charoite can be written as (Z= 1): (K13.88Sr1.0Ba0.32Mn0.36)Σ15.56(Ca25.64Na6.36)Σ32[(Si6O11(O,OH)6)2(Si12O18(O,OH)12)2(Si17O25(O,OH)18)2](OH,F)4.0·3.18H2O.
Description and crystal structure of a new mineral, edwardsite, Cu3Cd2(SO4)2(OH)6·4H2O, from Broken Hill, New South Wales, Australia
Authors: Elliott P. , Brugger J. , Caradoc-Davies T. 
Published: April 2010

AbstractEdwardsite, Cu3Cd2(SO4)2(OH)6·4H2O, is a new mineral from the Block 14 Opencut, Broken Hill, New South Wales, Australia. It occurs as druses of tabular and bladed crystals up to 0.06 mm in size, associated with niedermayrite and christelite. Edwardsite is pale blue, transparent with vitreous lustre and has excellent cleavage parallel to {100}. Density was not measured but the calculated density, from the empirical formula, is 3.53 g cm–3and the Mohs hardness is ∼3. Optically, it is biaxial negative with α ∼ 1.74, β = 1.762(4), γ ∼ 1.77 and 2Vcalc.∼ +62°. The optical orientation is X =b, Y ∼a, Z ∼c. Electron microprobe analysis gave (wt.%): CdO 32.43, CuO 28.06, ZnO 2.26, FeO 0.08, SO320.35, H2Ocalc.(from crystal-structure analysis) 14.14, totalling 99.32. The empirical formula, calculated on the basis of 18 oxygen atoms is Cu2.77Cd1.98Zn0.22Fe0.01(SO4)2.00(OH)5.95·4.06H2O. Edwardsite is monoclinic, space groupP21/c, witha= 10.863(2) Å,b= 13.129(3) Å,c= 11.169(2) Å, β = 113.04(3)°,V= 1465.9(5) Å3(single-crystal data) andZ= 4. The eight strongest lines in the powder diffraction pattern are [d(Å), (I/I0), (hkl)]: 9.991, (90), (100); 5.001, (90), (200, 21); 4.591, (45), (20); 3.332, (60), (300, 032); 3.005, (30), (03); 2.824, (40), (2); 2.769, (55), (20, 042, 10); 2.670, (45), (2). The crystal structure was determined by direct methods and refined toR1 = 3.21% using 1904 observed reflections withFo> 4σ(Fo) collected using synchrotron X-ray radiation (λ = 0.773418 Å). The structure is based on infinite sheets of edge-sharing Cuϕ6(ϕ: O2–, OH) octahedra and Cdϕ7(ϕ: O2–, H2O) polyhedra parallel to (100). The sheets are decorated on both sides by corner-sharing (SO4) tetrahedra, which also corner-link to isolated Cdϕ6octahedra, thus connecting adjacent sheets. Moderate-strong to weak hydrogen bonding provides additional linkage between sheets.
Ardennite, tiragalloite and medaite: structural control of (As5+,V5+,Si4+)O4 tetrahedra in silicates
Authors: Nagashima M. , Armbruster T. 
Published: April 2010

AbstractSeveral silicate-minerals, such as ardennite – Mn2+4MgAl5[Si5(As5+,V5+)O22](OH)6, Z = 2, tiragalloite – Mn2+4[Si3As5+O12(OH)], Z = 4 and medaite – Mn2+6[Si5(V5+,As5+)O18(OH)], Z = 4 possess (V5+,As5+,P5+)O4 tetrahedra. Using electron-microprobe analysis (EMPA) and single-crystal X-ray diffraction methods, the crystal chemistry of ardennite from Salam-Château, Belgium and the Vernetto mine, Italy, tiragalloite from the Gambatesa mine, Italy, and medaite from the Molinello mine, Italy and the Fianel mine, Switzerland, were studied. Structure refinements converged to R1 values of 2.10–5.67%. According to chemical analysis, the Σ(As+V+P) content increases with decreasing Si content. Thus, Si replaces pentavalent cations in tetrahedral coordination. The (As5+,V5+,P5+,Si4+)O4 tetrahedra are categorized by their connections to SiO4 tetrahedra. The (As5+,V5+,P5+,Si4+)O4 tetrahedron of ardennite is isolated, and those of tiragalloite and medaite terminate a tetrahedral chain. The <T–O> of the isolated (As5+,V5+,P5+,Si4+)O4 tetrahedron shows a positive correlation with the mean ionic radius. For (As5+,V5+,P5+,Si4+)O4 tetrahedra with one T–O–T link, <T–O> and mean ionic radius are also correlated. In addition, the longest bridging T–O bond occurs between (As,V,P,Si)O4 and the adjacent SiO4 tetrahedron. The bridging O atom is over-bonded to satisfy the charge requirement of Σ(As+V+Si).
Specific N-linked glycosylation sites modulate synthesis and secretion of von Willebrand factor
Authors: McKinnon Thomas A. J. , Goode Elizabeth C. , Birdsey Graeme M. , Nowak Agata A. , Chan Alain C. K. , Lane David A. , Laffan Michael A. 
Published: April 2010

AbstractWe examined the role that N-linked glycans play in the synthesis and expression of von Willebrand Factor (VWF). Blocking the addition of N-linked glycans (NLGs) or inhibiting initial glycan processing prevented secretion of VWF. To determine whether specific glycosylation sites were important, the 16 VWF N-linked glycosylation sites were mutated followed by expression in HEK293T cells. Four NLG mutants affected VWF expression: N99Q (D1 domain), N857Q (D' domain), N2400Q (B1 domain), and N2790Q (CK domain) either abolished or reduced secretion of VWF and this was confirmed by metabolic labeling. Multimer analysis of mutant N2790Q cell lysate revealed an increase in VWF monomers, which was also observed when the isolated CK domain was expressed with N2790 mutated. Immunofluorescence microscopy showed that mutants N99Q, N857Q, and N2790Q were primarily retained within the ER, producing only few pseudo Weibel-Palade bodies over longer time periods compared with wtVWF. All the variants also showed an increase in free thiol reactivity. This was greatest with N857Q and D4-C2 NLG mutants, which had approximately 6-fold and 3- to 4-fold more free thiol reactivity than wtVWF. These data provide further evidence of the critical role that individual N-linked glycans play in determining VWF synthesis and expression.
LYL1 activity is required for the maturation of newly formed blood vessels in adulthood
Authors: Pirot Nelly , Deleuze Virginie , El-Hajj Rawan , Dohet Christiane , Sablitzky Fred , Couttet Philippe , Mathieu Danièle , Pinet Valérie 
Published: April 2010

AbstractThe 2 related basic helix loop helix genes, LYL1 and TAL-1 are active in hematopoietic and endothelial lineages. While Tal-1 is essential for both hematopoietic and vascular development, the role of Lyl1 appears to be distinct as deficient mice are viable and display modest hematopoietic defects. Here, we reveal a role for Lyl1 as a major regulator of adult neovascularization. Tumors implanted into Lyl1-deficient mice showed higher proliferation and angiogenesis, as evidenced by enlarged lumens, reduced pericyte coverage and increased permeability, compared with wild type littermates. Of note, Lyl1-deficient tumor vessels exhibited an up-regulation of Tal-1, the VE-Cadherin target gene, as well as Angiopoietin-2, 3 major actors in angiogenesis. Hematopoietic reconstitution experiments demonstrated that this sustained tumor angiogenesis was of endothelial origin. Moreover, the angiogenic phenotype observed in the absence of Lyl1 function was not tumor-restricted as microvessels forming in Matrigel or originating from aortic explants were also more numerous and larger than their wild-type counterparts. Finally, LYL1 depletion in human endothelial cells revealed that LYL1 controls the expression of molecules involved in the stabilization of vascular structures. Together, our data show a role for LYL1 in the postnatal maturation of newly formed blood vessels.