Search results for "COMPOSITION"

Thermal behaviour of anhydrous, dihydrate and (2/1) ethanol forms of 1-O-α-d-glucopyranosyl-d-mannitol

1998

Abstract The melting points of anhydrous 1-O-α- d -glucopyranosyl- d -mannitol, 1-O-α- d -glucopyranosyl- d -mannitol dihydrate and a new compound, 1-O-α- d -glucopyranosyl- d -mannitol-ethanol (2/1) were determined using differential scanning calorimetry. The melting onset values were 169.2 (3), 104.3 (18) and 158.7 (9), respectively, and the melting peak values were 171.4 (5), 107.9 (15) and 160.1 (6), respectively. 1-O-α- d -glucopyranosyl- d -mannitol dihydrate and 1-O-α- d -glucopyranosyl- d -mannitol-ethanol (2/1) decompose to anhydrous form when heated at slow heating rates. According to TG-FTIR measurements, 1-O-α- d -glucopyranosyl- d -mannitol-ethanol (2/1) lost its ethanol in the…

Synthesis and Crystal Structure of Ln3(OH)(CrO4)4 · 3.5H2O (Ln = Pr, Nd) and Ln2(OH)2(CrO4)2 (Ln = Tb, Gd): Thermal Behavior and Infrared Spectra of …

1993

Abstract Crystal structures of Ln 2 (OH) 2 (CrO 4 ) 2 ( Ln = Gd, Tb) and Ln 3 (OH)(CrO 4 ) 4 · 3.5H 2 O ( Ln = Pr, Nd) were determined by a conventional single-crystal X-ray diffraction technique. Crystals of Ln 2 (OH) 2 (CrO 4 ) 2 ( Ln = Gd, Tb) are monoclinic, space group P 2 1 / c (no. 14) with lattice parameters a = 8.2454(4) A, b = 11.3834(5) A, C = 12.1420(8) A, and β = 136,590(5)°, Z = 4, D x = 4.92 mg · m -3 for Gd 2 (OH) 2 (CrO 4 ) 2 and a = 8.214(1) A, b = 11.348(1) A, c = 12.094(2) A, and β = 136.59(1)°, Z = 4, D x = 5.01 Mg · m -3 for Tb 2 (OH) 2 (CrO 4 ) 2 . Crystals of Ln 3 (OH)(CrO 4 )) 4 · 3.5H 2 O ( Ln = Pr, Nd) are monoclinic, space group C 2/ c (No. 15) with lattice param…

�ber die Hemmung der Atp-Spaltung in der D�nndarmschleimhaut durch Kupfer

1952

Calcium dialysability as an estimation of bioavailability in human milk, cow milk and infant formulas

1999

Abstract The calcium dialysability of human milk, cow milk and infant formulas is estimated by applying the in vitro method (Miller, Schricker, Rasmussen, & Van Campen, (1981). American Journal of Clinical Nutrition, 34, 2248–2256) slightly modified, as a measure of its bioavailability. The influence of the protein composition of infant formula samples on calcium bioavailability is also studied. Whole cow milk, a pool of human milk and 18 commercial infant formulas of 6 different types are analysed. The highest values of calcium dialysability (mg Ca/100 ml infant formula) correspond to premature (13.6) and follow-up formulas (11.8) and the lowest ones to adapted formulas (3.7); the latter v…

Medical Geochemistry

2013

Preface.- How trace element contents in bronchoalveolar lavages can probe the human exposure to inhaled particulates.- Geochemistry and Biochemistry - insights into the fate and transport of Pt-based chemotherapy drugs.- Atmospheric Particulate Matter (PM) in the Middle East: Toxicity, trans-boundary transport and influence of synoptic conditions.- Reaction path modeling: theoretical aspects and applications.- An observation on the composition of urinary calculi: environment influence.- Magnetite minerals in the human brain: what's their role?.- Chemometrics and Medical Geochemistry: A brief tutorial.- Dust, metals and metalloids in the environment: from air to hair.- Metal Geochemistry of …

Molecular Characterization and Source Identification of Atmospheric Particulate Organosulfates Using Ultrahigh Resolution Mass Spectrometry.

2019

Organosulfates (OSs) have been observed as substantial constituents of atmospheric organic aerosol (OA) in a wide range of environments; however, the chemical composition, sources, and formation mechanism of OSs are still not well understood. In this study, we first created an "OS precursor map" based on the elemental composition of previous OS chamber experiments. Then, according to this "OS precursor map", we estimated the possible sources and molecular structures of OSs in atmospheric PM2.5 (particles with aerodynamic diameter ≤ 2.5 μm) samples, which were collected in urban areas of Beijing (China) and Mainz (Germany) and analyzed by ultrahigh-performance liquid chromatography (UHPLC) c…

Radical Formation by Fine Particulate Matter Associated with Highly Oxygenated Molecules

2019

Highly oxygenated molecules (HOMs) play an important role in the formation and evolution of secondary organic aerosols (SOA). However, the abundance of HOMs in different environments and their relation to the oxidative potential of fine particulate matter (PM) are largely unknown. Here, we investigated the relative HOM abundance and radical yield of laboratory-generated SOA and fine PM in ambient air ranging from remote forest areas to highly polluted megacities. By electron paramagnetic resonance and mass spectrometric investigations, we found that the relative abundance of HOMs, especially the dimeric and low-volatility types, in ambient fine PM was positively correlated with the formatio…

Enhancer blocking activity located near the 3′ end of the sea urchin early H2A histone gene

1997

The sea urchin early histone repeating unit contains one copy of each of the five histone genes whose coordinate expression during development is regulated by gene-specific elements. To learn how within the histone repeating unit a gene-specific activator can be prevented to communicate with the heterologous promoters, we searched for domain boundaries by using the enhancer blocking assay. We focused on the region near the 3′ end of the H2A gene where stage-specific nuclease cleavage sites appear upon silencing of the early histone genes. We demonstrated that a DNA fragment of 265 bp in length, defined as sns (for silencing nucleoprotein structure), blocked the enhancer activity of the H2A…

Dependence of solvent quality on the composition of copolymers: experiment and theory for solutions of P(MMA-ran-t-BMA) in toluene and in chloroform.

2014

The interaction of toluene with P(MMA-ran-t-BMA) and with the corresponding homopolymers was determined via vapor pressure measurements at 30, 50 and 70 °C. A unified thermodynamic approach served for the modeling of the results. It is capable of describing the behavior of the different solutions by means of two adjustable parameters, one representing the effective number of solvent segments and the other accounting for the interactions between the components. The solvent quality of toluene passes a maximum, a minimum and another maximum upon an increase of the t-BMA content of the copolymer at all temperatures. A similar behavior is discernable from vapor pressure data of chloroform publis…

Physiological Aspects of Nitrogen Fertilizer Impact on Latvian Origin Cannabis Sativa L .

2015

The aim of the present study was to evaluate nitrogen fertilizer impact on photosynthesis and yield of hemp, applying modern non-destructive methods. The main object of the investigation – hemp cultivar of Latvian origin ‘Pūriņi’. Laboratory and field experiments showed diverse effects of different nitrogen fertilizer doses on various parameters. Additional nitrogen fertilizer dose of 60 kg ha-1 is most effective as evaluated by chlorophyll content in hemp leaves and changes of chlorophyll a fluorescence parameters. Nitrogen fertilizer negatively affected fiber content in hemp stems, therefore while cultivating hemp only for fiber production use of nitrogen fertilizer should be reduced. Acc…