Miracle-dz/UniFAR-FTUs huggingface dataset:
Synthesis and Characterization of Poly(N-tert- amylacrylamide-co-Acrylamide/Sodium acrylate) Gold Nanocomposite Hydrogels Chemistry

In the present study, a series of Poly (N-tert-amylacrylamide –co –acrylamide / Sodium acrylate) gold nanocomposite hydrogels were synthesized by free-radical copolymerization in Water/Methanol medium using Ammonium persulfate (APS) as the initiator and N,N’-methylenebisacrylamide (MBA) as a crosslinker. The amount of N-tert-amylacrylamide (NTA) and Acrylamide (AM) monomers are fixed (50:50) and the amount of Sodium Acrylate (AcNa) ionic monomer was varied from 0.1g to 0.5g. The swelling ehaviour of Nanocomposite Hydrogels studied by Gravimetric method and degree of swelling was increased by increasing the amount of Sodium acrylate. The surface morphology was studied by SEM analysis and it indicates the formation spherical shaped gold nanoparticle in the polymer matrix.
On the Change of Resistance of Nickel in a Magnetic Field

In a recent paper Gerlach and Schneiderhan have described a series of experiments on the resistance of nickel considered both as a function of the temperature and as a function of an external field applied parallel to the wire. In the absence of an external field the change of resistance with temperature can be considered as made up of two terms, the first being due to the result of the ordinary temperature coefficient of resistance, and the second (∆R) being proportional to the energy of spontaneous magnetisation. According to the Weiss theory this energy of spontaneous magnetisation is equal to ‒½ n σ2, where n is the constant of the intramolecular field and σ the volume intensity of magnetisation. Plotting ∆R against T, and σ2 against T, Gerlach and Schneiderhan obtained curves which were coincident over the whole range from room temperature to the Curie point. The agreement is extra­ordinarily close and leaves no doubt as to the intimate connection between ∆R and σ2.
METABOLIC TOTAL PROTEIN INVESTIGATION IN LOCAL INDUSTRY WORKERS EXPOSED TO ACID ANHYDRIDES

Organic acid anhydrides (OAAs) are low molecular weight industrial chemicals widely used in all of the main industries. Hyderabad is an important commercial center where industry is booming in and around the city including; Textiles, plastics, dyes, paints, adhesives and pesticides. In the before mentioned industries, use of most reactive organic acid anhydrides is common such as; Phthalic Anhydride, Succinic Anhydride, Maleic Anhydride, Trimellitic Anhydride and Acetic Anhydride. Studies show that Anhydrides are irritants and potent inducers of Asthma, Rhinitis, Allergy and even Cancer (Moller et al., 985; Nielsen, 1992 and Venables, 1989), but still metabolic Protein studies have not been carried out before to differentiate between the workers and healthy subjects. This study is especially made to investigate differences in the workers, clinically and Metabolically. Total proteins and serum albumins were determined from the intravenous blood samples of the control group and exposed workers from one of the major local industries. The study will be useful for both, the industries and clinicians to safeguard the human health by treating these exposed workers to lead their normal lives.
Synthesis, Crystal Structures, and Magnetic Properties of Ternary M(II)-Dicyanamide-hydroxypyridine Complexes

Three two-dimensional (2D) and 3D supramolecular coordination architectures based on ternary M(II)-dicyanamide-2-hydroxypyridine systems, [Co(hmpH)2(dca)2] (1), [Cu(hmpH)2(dca)2] (2), and [Mn(hepH)2(dca)2] (3) (dca = dicyanamide, hmpH = 2-(hydroxymethyl)pyridine, hepH = 2-(hydroxyethyl)pyridine), have been synthesized. 1 is a mononuclear Co(II) complex. The mononuclear units are interlinked into a 2D (4,4) hydrogen-bonded layer via O–H⋯N hydrogen bonds between the hydroxyl groups and the noncoordinating nitrile ends. These 2D layers are further extended into a 3D supramolecular architecture via the interlayer pyridyl-pyridyl stacking interaction. 2 has a 1D coordination chain structure formed by the double 1,5-dca bridged dinuclear [Cu2(1,5-dca)2(hmpH)2] unit and the 1,3-dca bridges via weak Cu–N coordination, and these 1D coordination chains are further extended into 2D hydrogen-bonded layers via strong O–H⋯N hydrogen-bonding interaction between the hydroxyl groups and the noncoordinating nitrile ends. 3 is a 2D (4,4) coordination network made of 1D [Mn(hepH)(1,5-dca)] helical chain units and interchain double (1,5-dca) bridges. Pairs of [Mn(hepH)(1,5-dca)] helical chains are interlinked by the double (1,5-dca) bridges into a racemic coordination layer structure, which is further extended into a 3D hydrogen-bonded network. Magnetic studies reveal that weak antiferromagnetic exchange occurs in 3.
Impact of grain scale heterogeneity on slow sorption kinetics

Groundwater contamination by dissolved organic compounds frequently occurs in valley aquifers that consist of highly heterogeneous sand and gravel sediments. Remediation and risk assessment (e.g. reactive transport modeling) requires detailed information on the sorption/desorption kinetics in such aquifer materials. In this paper we present data on slow sorption kinetics of phenanthrene and the composition of several aquifer materials that are typical for southern Germany and Switzerland. The heterogeneity of the aquifer material is described in terms of the physical and chemical properties (e.g., grain size, organic carbon content, intraparticle porosity, sorption parameters, and rate constants for intraparticle diffusion) of the sediment constituents (lithocomponents). Phenanthrene sorptive uptake in a heterogeneous bulk sample can be predicted using a numerical model only if the composition and geochemical heterogeneity (different sorptivities and porosities of the lithocomponents) are considered. It could be shown that even within a narrow grain size fraction, the geochemical heterogeneity has to be incorporated for the prediction of long‐term sorptive uptake or release of organic contaminants.
UPLC analysis of common parabens in cosmetic products

Summary A simple and rapid ultra-performance liquid chromatographic (UPLC) method for analysis of parabens in cosmetic products has been developed and validated. Four preservatives (methylparaben, ethylparaben, propylparaben, and butylparaben) were extracted by ultrasonication with methanol. Separation was achieved by use of a C18 column (2.1 mm × 50 mm i.d., 1.7 μm particle size) and gradient elution with methanol-water-phosphoric acid as mobile phase. Photodiode-array (PDA) detection was used and quantification with MaxPlot was in the range 210–400 nm. Regression analysis revealed linear relationships between peak area and amount of each additive from 0.1 to 10 μ mL−1, with correlation coefficients between 0.9971 and 0.9983. Inter-day and intraday precision for the four preservatives at three concentrations were 0.04–0.05% for retention time and 0.81–1.29% for peak area. Recovery was from 91.4–105.8%. The method was used for analysis of parabens in cosmetics and was proved suitable for rapid and reliabl.
PICK TWO POINTS IN A TREE

In ordered trees, two randomly chosen vertices are said to be dependent if one lies under the other. If not, we say that they are independent. We consider several classes of ordered trees with uniform updegree requirements and find the generating functions for the trees with two marked dependent/independent vertices. As a result, we compute the probability for two vertices being dependent/independent. We also count such trees by the distance between two independent vertices.
Study on electrical properties of metal/GaSb junctions using metal-GaSb alloys

We study the metal-GaSb alloy formation, the structural properties and the electrical characteristics of the metal-alloy/GaSb diodes by employing metal materials such as Ni, Pd, Co, Ti, Al, and Ta, in order to clarify metals suitable for GaSb p-channel metal-oxide-semiconductor field-effect transistors (pMOSFETs) as metal-GaSb alloy source/drain (S/D). It is found that Ni, Pd, Co, and Ti can form alloy with GaSb by rapid thermal annealing at 250, 250, 350, and 450 °C, respectively. The Ni-GaSb and Pd-GaSb alloy formation temperature of 250 °C is lower than the conventional dopant activation annealing for ion implantation, which enable us to lower the process temperature. The alloy layers show lower sheet resistance (RSheet) than that of p+-GaSb layer formed by ion implantation and activation annealing. We also study the electrical characteristics of the metal-alloy/GaSb junctions. The alloy/n-GaSb contact has large Schottky barrier height (ϕB) for electrons, ∼0.6 eV, and low ϕB for holes, ∼0.2 eV, which e.
Deterioration of Polymeric Materials Exposed to Metabolic Activity of Microorganisms in a Water Distribution System

Internal surfaces of polymeric (PVC, PE, PP, and PB) pipes were assessed for potential colonization by microorganisms present in a water distribution system. Biofilms that had formed on the surfaces of particular polymer samples were examined by SEM microscopy and Koch's method. Surface damage caused by microbial activity was measured by contact profilometry. PP (1.5×10 6 CFU/cm
Preparation and characterization of alumina-supported Co and Ag/Co catalysts

The effect of silver addition as a promoter in alumina supported cobalt oxide catalysts is investigated in this study. The Co/Al2O3 and Ag/Co/Al2O3 catalysts were prepared by incipient wetness impregnation. The catalysts were characterized by inductively-coupled plasma spectrometry, X-ray diffraction (XRD), temperature programmed reduction with hydrogen (TPR-H2), Raman spectroscopy and nitrogen adsorption at 77 K. XDR and Raman Spectroscopy results indicated the presence of Co3O4 species. The peaks observed in the TPR-H2 patterns were attributed to the reduction of Ag2O, Co3O4 crystallites and Co+3, Co+2 species interacting with alumina. It is suggested that silver used as a promoter favors the reduction of cobalt, facilitating the formation of active Co0 sites.
Modification of biodegradable polylactide by silica and wood flour through a sol–gel process

The aim of this work is the production of new biodegradable nanocomposites from polylactide (PLA), tetraethoxysilane (TEOS), and wood flour (WF) by means of an in-situ sol–gel process and a melt blending method. Characterizations of SiO2, PLA, and hybrids were performed by FTIR, 29Si solid-state NMR, XRD, DSC, TGA, and SEM analyses. As the results, the SiO2 can be well dispersed into the acrylic acid grafted polylactide (PLA-g-AA) in nanoscale sizes since the TEOS is partially compatible with PLA-g-AA and allows PLA-g-AA chains intercalating into SiO2 layers. 29Si solid-state NMR analysis showed that Si atoms coordinated around SiO4 units were predominantly Q3 and Q4. The PLA-g-AA/SiO2 hybrid demonstrates dramatic enhancement in thermal and mechanical properties of PLA; for example, 80°C and 20 MPa increases in IDT and TS with the addition of 10 wt % SiO2 due to the formation of SiOC bond, and the nanoscale dispersion of silicate layers in the polymer matrix. On the basis of the consideration of thermal and mechanical properties, it is also found that 10 wt % of SiO2 content is optimal for preparation of PLA-g-AA/SiO2 nanocomposites. The biodegradable nanocomposites produced from our laboratory can provide a plateau tensile strength at break when the WF content is up to 50 wt %. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
A study of polypyrrole synthesized with oxidative transition metal ions

Polypyrrole powder and films were chemically synthesized by the reaction of AgNO3, FeCl3, Fe(NO3)3, Cu(NO3)2, or Cu(NO3)2-AlCl3 with pyrrole in an aqueous solution or a water—toluene two-phase system. Products were characterized by elemental analysis, IR, scanning electron microscopy with energy dispersive x-ray analysis (SEM with EDAX), and conductivity measurements. The polypyrrole synthesized from pyrrole with FeCl3 had a composition of C4.00H3. 05N0.99Cl0. 25. The pressed powder had a conductivity of 2.7 × 10−2 S/cm and the film 2.8 S/cm. All the other metal salts produced films that had the same organic backbone, morphology, and conductivity as the polymer synthesized using Fe(III) salts, regardless of the considerable differences in the reduction potentials of the metal ions. The nature of the anions of the transition metal salts had no effect on the reaction. Anions, however, were retained as the counterions of the cationic polypyrrole backbone and could be easily exchanged with other anions.
Vanadium and nickel complexes in petroleum resid acid, base, and neutral fractions

Acid and base fractions from petroleum vacuum resids with no detectable (by visible spectrophotometry) quantities of porphyrinic Ni or V complexes were hydrotreated under various conditions to determine if significant amounts of porphyrinic metals were released, via disassociation or other means, upon hydrotreating. No significant quantities were observed, thereby indicating that nonporphyrinic metals were not simply associated, complexed or otherwise masked (in terms of visible spectrophotometric response) porphyrinic metal complexes. However, it is possible that hydrotreating was simply not effective in breaking up these associates and/or that some porphyrinic forms of metal were in fact released but were rapidly destroyed by hydrotreating. In addition, three liquid chromatographic (LC) separation methods were sequentially applied to Cerro Negro (Orinoco belt Venezuelan heavy crude) >700{degree}C resid in an effort to separate and concentrate the metal complexes present. Nonaqueous ion exchange chromatography was used initially to separate the resid into acid, base and neutral types. Two concentrates containing 19,500 and 13,500 ppm total V, or an estimated 19 and 13 wt % V-containing compounds respectively, were obtained. The degree of enrichment of Ni compounds obtained was significantly lower. By visible spectrophotometry, using vanadyl etioporphyrin as a standard, each of the concentrates contained near amore » 1:1 ratio of porphyrinic:nonporphyrinic V complexes. Analogous separation behavior for porphyrinic versus nonporphyrinic metal forms was observed throughout much of the work, thereby suggesting that a comparable diversity of structures existed within each general class of metal compounds. The generally wide dispersion of both Ni and V over the LC separation scheme suggests a structural variety of metal complexes that is comparable to that observed for other heteroatoms (N, S, O) in petroleum. « less
Pressure and angle of incidence effects in reactive planar magnetron sputtered ZnO layers

ZnO films have been prepared by rf sputtering a Zn target in a planar magnetron system with controlled Ar/O2 gas mixtures. The films were deposited on unheated glass substrates which were either stationary in front of the target or in constant motion. Both the system pressure and plasma impedance changed when an oxide layer formed on the target surface. This occurred at an oxygen flow rate which increased almost linearly with rf power; at 500 W, the required flow rate was 9 ml/min and the pressure increased from 0.1 to 1.2 Pa due to the reduced oxygen gettering. High resistance ZnO films were deposited at oxygen flow rates above this threshold value. The target self‐bias voltage increased by 30 V at this value; it is affected by both the system pressure and the power. The deposition rate increased linearly with power at approximately 0.03 (μm/min)/(W/cm2) which appears to be typical of sputtering from a ZnO layer or target. For continuous substrate motion, the average rate was approximately 7% of this val.
Structure Elucidation and Total Synthesis of Altenuic Acid III and Studies towards the Total Synthesis of Altenuic Acid II

The structure of the Alternaria mycotoxin altenuic acid III was elucidated by NMR spectroscopic analysis of an authentic sample, and was confirmed by total synthesis. This compound is not a resorcylic acid lactone but a resorcylic acid substituted with a butenolide, and thus is the first member of a new class of alternaria toxins. For the total synthesis, a short and efficient access to halogenated butenolides bearing acetal-protected side-chains was carried out. Suzuki coupling of these butenolides with a highly functionalized boronate gave rise to a precursor of the natural product in high yield. The side-chain was completed by deprotection and subsequent oxidation. An unexpected cascade reaction leading to tricyclic butenolides was discovered during optimization of the deprotection protocol. Cleavage of the acetal protecting group gave altenuic acid III. Furthermore, a synthetic study towards altenuic acid II, a compound with a characteristic spirolactone structure, is described. It was planned to construct the spirocyclic lactone by using an intramolecular Michael-type addition of an aromatic carboxylate group to a butenolide moiety, but this approach was not successful. While testing the feasibility of this concept, a new and mild protocol for the well-known Pinner reaction in the presence of Lewis acids was discovered.
SLP-76-Cbl-Grb2-Shc Interactions in FcγRI Signaling

SLP-76 and Cbl are complex adapter proteins that have the capacity to bind to smaller adapter proteins, such as Grb2, which subsequently binds the nucleotide exchange protein Sos in the transmission of intracellular signals. SLP-76, Cbl, Shc, and Grb2 have been implicated in immunoreceptor tyrosine-based activation motif (ITAM) signaling, leading to activation of Ras. However, their mechanism of action has not been determined. To date, there have been no reports of SLP-76 involvement in FcγRI-receptor signaling and no data exist for an interaction between Cbl, Shc, and SLP-76 in vivo. We provide evidence that SLP-76, Cbl, and Shc are tyrosine phosphorylated on FcγRI-receptor stimulation and are associated with the adapter protein Grb2 in γ-interferon–differentiated U937 cells (U937IF). The interactions between SLP-76 and Cbl and SLP-76 and Grb2 are present in resting U937IF cells. However, the interaction between SLP-76 and Grb2 becomes augmented twofold on FcγRI-receptor aggregation. Our results provide the first evidence for a phosphorylation-dependent interaction between SLP-76 and Shc, induced at least 10-fold on FcγRI receptor stimulation. Our data indicate that a significant portion of a multimolecular complex containing Cbl, SLP-76, Shc, and Grb2 is distinct from a trimolecular complex containing the Ras guanine nucleotide exchanger Sos, Shc, and Grb2. FcγRI-induced tyrosine phosphorylation of SLP-76, Cbl, Shc, and the highly induced SLP-76-Shc interaction provide the first evidence that SLP-76 and Cbl are involved in FcγRI signaling and suggest a functional significance for these interactions in FcγRI signal relay in the control of Ras in myeloid cells. © 1998 by The American Society of Hematology.
CARBON DIOXIDE EVOLUTION FROM VIRGIN AND CULTIVATED SOIL AS AFFECTED BY MANAGEMENT PRACTICES AND CLIMATE

Soil respiration during the growing season was calculated from CO2 profiles in a heavy clay soil under native grass and on cultivated plots. Soil respiration of the native grass plots was correlated with moisture content and temperature of the surface soil. However, the correlation accounted for only ⅓ of the observed variation in soil respiration and could not explain the large difference between two growing seasons. Addition of mineral N decreased soil respiration and irrigation increased it. Total soil respiration on the cultivated plots was higher than on the native grassland. On the wheat plots, soil respiration was significantly correlated with soil moisture but not with temperature; the reverse was true for the fallowed plots. Soil respiration between 1 May and 1 September on the native grassland was highly correlated with rainfall and the number of days with rain in excess of 5 mm. It was concluded that the number of wetting and drying cycles in the soil was mainly responsible for the annual varia.
Organic matter in interplanetary dust particles

Abstract Anhydrous interplanetary dust particles (IDPs), which are the most mineralogically primitive extraterrestrial materials available for laboratory analysis, contain several percent organic matter. The high O:C and N:C ratios suggest the organic matter in the anhydrous IDPs is significantly less altered by thermal processing than the organic matter in meteorites. X-ray Absorption Near-Edge Structure (XANES) spectroscopy and infrared spectroscopy demonstrate the presence of C=C, most likely as C-rings, C=O, and aliphatic C-H2 and C-H3 in all the IDPs examined. A D-rich spot, containing material that is believed to have formed in a cold molecular cloud, has C-XANES and infrared spectra very similar to the organic matter in the anhydrous IDPs, possibly indicating a common formation mechanism. However the primitive organic matter in the IDPs differs from the interstellar/circumstellar organic matter characterized by astronomical infrared spectroscopy in the relative strengths of the asymmetric aliphatic C-H2 and C-H3 absorptions, with the IDP organic having a longer mean chain length. If both types of organic matter originated by the same process, this may indicate the interstellar organic matter has experienced more severe radiation processing than the organic matter in the primitive IDPs.
Molecular dynamics simulations and QM/MM studies of the reactivation by 2-PAM of tabun inhibited human acethylcolinesterase

A elucidacao das rotas de reativacao da acetilcolinesterase humana (HuAChE) inibida por organofosforados e de crucial importância para o desenvolvimento de antidotos eficientes contra a intoxicacao causada por agentes de guerra quimica. Com o objetivo de contribuir para uma melhor compreensao do mecanismo de reativacao, foram aplicadas neste trabalho simulacoes de dinâmica molecular (DM) classica para estudar as interacoes entre a pralidoxima e aminoacidos do sitio ativo da HuAChE inibida pelo agente neurotoxico tabun. Alem disso, metodos hibridos de mecânica quântica/mecânica molecular (QM/MM) foram usados para propor um mecanismo de reativacao para a enzima inibida. Os resultados mostraram que a DM classica manteve a pralidoxima no interior do sitio ativo da enzima, em uma regiao favoravel a ocorrencia de uma possivel reacao de desfosforilacao, que foi confirmada por metodos de QM/MM, levando a proposta de um mecanismo de reativacao, energeticamente favoravel. The elucidation of the reactivation routes of human acetylcholinesterase (HuAChE) inhibited by organophosphorous compounds is of crucial importance to the development of efficient antidotes against poisoning by chemical warfare agents. In order to contribute to a better understanding of the reactivation mechanism, we applied, in this work, classical molecular dynamics (MD) simulations to study the interactions between pralidoxime and the active site's amino acids of HuAChE inhibited by the neurotoxic agent tabun. Further, quantum mechanical/molecular mechanical (QM/MM) hybrid methods were used to propose a reactivation mechanism for the inhibited enzyme. The results showed that the classic MD kept pralidoxime inside the enzyme's active site, in a favorable region to the occurrence of possible reactions of dephosphorilation, which were confirmed by QM/MM methods, and lead to the proposition of an energetically favorable mechanism of reactivation.