Miracle-dz/UniFAR-FTUs huggingface dataset:
Spray Drying of S-Adenosyl-L-Methionine in Saccharomyces cerevisiae K-9

S-Adenosyl-L-methionine (SAM) production from Saccharomyces cerevisiae K-9 was comparatively stable under slightly acidic conditions (pH 3.0–5.0) and at low temperature (20–25°C). The kinetics of SAM degradation and 5′-methylthioadenosine (MTA) formation in yeast solution at high temperature (40–60°C) were described by zero-order reactions and the activation energy levels were 104 and 102 kJ/mol, respectively. The optimum retention of SAM after spray drying was obtained at 120°C inlet air temperature. The water content of the powder has a significant effect on the stability of SAM. The SAM yeast powder with trehalose and maltodextrin (dextrose equivalent, DE = 25), used as carrier solids, exhibited higher stability.
Dissociation Constants of Ammonium Ion and Activity Coefficients of Ammonia in Aqueous Ammonium Sulfate Solutions

Dissociation constants of NH4+ ion, Ka,c = cH+(T)cNH3/cNH4+, where c denotes molarity and cH+(T) = cH+ + cHSO4-, were determined at 298.15 K in aqueous (NH4)2SO4 solutions at different ionic strengths (I = 0.75−7.5 mol dm-3) by potentiometry using a glass electrode. The Ka,c values were converted to those on the molality basis by use of the densities of the corresponding solutions. The activity coefficients of ammonia, γc,NH3 and γm,NH3, respectively, on the molar and molal bases, were determined by a transpiration method. The observed dissociation constants on the molality basis, pKa,m, were compared with those calculated from the Pitzer equations.
Manipulating and imaging individual membrane proteins by AFM

Membrane proteins are nanometric machines fulfilling defined functions in the membranes of all living cells. They work as transporters, linkers, adhesion molecules, channels, pumps, receptors and enzymes, and in bio‐energetic machineries, to name only a few tasks. In agreement with their multiple functions and importance, it was found that about 25% of all genes code for membrane proteins in organisms ranging from bacteria to humans. Biologists now have a set of techniques such as X‐ray crystallography, electron microscopy, and atomic force microscopy to analyze membrane protein structure, and techniques such as patch‐clamp, black lipid membrane and spectroscopy on membrane vesicles to analyze membrane function. Atomic force microscopy is widely used for imaging and force measurements, and here, its use as a unique tool to nano‐manipulate individual membrane proteins is reviewed. In this ‘mode’, additional loading forces are applied to an imaging tip, and scan rates and feedback parameters are adjusted to deliberately act on the surface of the biological object. When additional loading forces are relatively high (∼500 pN), stacked membrane layers can be dissected to give access to underlying membranes. Similarly, subunits from a multi‐protein complex can be dissected at slightly increased forces (∼200 pN) allowing the analysis of underlying protein structures, and hence that of the complex architecture. At low additional loading forces (∼100 pN), individual protein loops can be manipulated. Importantly, this process is nondestructive and provides access for the analysis of flexible protein surface domains. Copyright © 2006 John Wiley & Sons, Ltd.
Simultaneous surface plasmon optical and electrochemical investigation of layer-by-layer self-assembled conducting ultrathin polymer films

In this study, we use a novel method for simultaneously measuring the optical and electrochemical properties of layer-by-layer self-assembled conducting ultrathin polymer films. We employed the recently developed combination of in situ surface plasmon resonance spectroscopy (SPS) and surface plasmon field-enhanced light scattering (SPFELS) with an electrochemical method (cyclic voltammetry). Polyaniline (PANI) and sulfonated polyaniline (SPANI) were used as the polycation and the polyanion for the conducting layer-by-layer film assemblies. The doping−dedoping process of the PANI/SPANI at different film thicknesses was investigated by electrochemical-SPS/SPFELS. The potential cycling resulted in characteristic oscillations that were sensitively monitored with this technique. We were able to obtain in situ information on dielectric constant changes of the PANI/SPANI layer-by-layer films with respect to film thickness and their corresponding morphology transitions during the electrochemical process. Thus, th.
State of the art report of selenium speciation in biological samples

Selenium is an essential trace element for humans and animals. It plays a putative role in the prevention of cancer and other illnesses. The increasing use of selenium in food and fodder supplementation has resulted in a need for high-performance analytical methods allowing the characterisation of the marketed products. Reliable and validated analytical methods applied in this research field are urgently needed. This review presents the state-of-the-art of systematic developments concerning different aspects of qualitative and quantitative selenium speciation analyses in biological samples.
Simulation of arc discharge modes in vacuum chamber

An interconnection between contact erosion and arc discharge formation was discovered. These results are explained by a mathematical model. The model describes a current density distribution in the arc contact system and takes into account the thermal processes in the intercontact gap. An electrical field instead of a magnetic field determines the formation of the arc mode to a greater degree. Simulations of processes occurring in the arc for some versions of contact system design have been carried out. Their defects and advantages are considered. The best design criterion is provided by a current-carrying electrode system where the conditions of arc motion, during action of the discharge on the electrode system, are minimized. These conditions are existent when the electric field intensity maximum is placed at the outside of the gap.
Wavelength selection method for multicomponent spectrophotometric determinations using partial least squares

A method for eliminating unnecessary wavelengths is applied with the goal of achieving improved prediction ability in multicomponent determinations by UV/VIS spectrophotometry with partial least squares (PLS). The feature selection method is based on the regression coefficients of the closed form of the PLS model. This method was evaluated with calibration data of different types, and with different criteria to choose the optimum number of factors. The results presented suggest that wavelength selection improves the prediction ability of PLS method.
Growth Kinetics and Modeling of ZnO Nanoparticles

This article describes a method to measure the growth kinetics of a zinc oxide colloid. Using common instrumentation such as UV–vis spectroscopy, the cut-off wavelength can be determined and hence, the particle size can be estimated. Using existing models of colloidal nanoparticle properties, the absorbance is modeled and compared to the experimental curves. The effect of different parameters in the model such as particle size, refractive index, and solvent type are investigated and conclusions drawn about the nature of nanoparticulate systems.
2D QSAR studies on a series of bifonazole derivatives with antifungal activity.

Candida albicans (CA) has been identified as the major opportunistic pathogen in immunosuppressed patients. Most of currently available drugs are either highly toxic or becoming ineffective against resistant strains. An approach to overcome this burden relies on azole derivatives with increased potency and selectivity. Aiming at shedding some light on structural and chemical features that are important for the antifungal activity of azole derivatives, classical 2D QSAR and hologram QSAR (HQSAR) studies were performed for a diverse set of 52 bifonazole derivatives with antifungal activity. Topological descriptors, employed in Classical QSAR studies, resulted in models with low correlation (r2 = 0.38, q2 = 0.27) and lack of predictive power (r2pred = -0.6). On the other hand molecular holograms afforded HQSAR models with good correlation coefficients (r2 = 0.92, q2 = 0.65) and good predictive ability (r2pred = 0.79).
综合康复锻炼对乳腺癌I期乳房重建术后上肢功能康复和生活质量的影响

目的 探讨综合康复锻炼对乳腺癌Ⅰ期乳房重建术后患者的康复效果. 方法 将118例行乳腺癌Ⅰ期乳房重建术后的患者按随机数字表法分为康复锻炼Ⅰ组、康复锻炼Ⅱ组和对照组,康复锻炼Ⅰ组42例,康复锻炼Ⅱ组35例,对照组41例. 对照组采用常规的乳腺癌术后康复锻炼；康复锻炼Ⅰ组于术后10 d在乳腺癌常规康复操的基础上辅以健身秧歌舞运动疗法,康复锻炼Ⅱ组于术后10d在乳腺癌常规康复操的基础上辅以太极拳运动疗法. 以Constant-Murley肩功能测评标准和WHOQOL-BREF生活质量简表为测评依据,对患者在术后10 d及1、3和6个月分别进行测评. 结果 积极进行康复锻炼的患者患肢功能及生活质量均有提高,辅以太极拳锻炼的康复锻炼Ⅱ组在上肢功能恢复和生活质量方面均优于辅以秧歌舞锻炼的康复锻炼Ⅰ组和对照组(P＜0.05). 结论 辅以太极拳运动的综合康复锻炼可以促进乳腺癌Ⅰ期乳房重建术后患侧上肢功能康复和提高患者生活质量,是乳腺癌术后比较理想的康复锻炼方式。
Spark Plasma Sintering à partir de poudres mécaniquement activées : compréhension des transitions de phase au cours d'un frittage réactif

A "basse temperature" (entre 400 et 600 °C), l'oxydation de MoSi2 entraine sa desintegration en poudre (phenomene de "peste"). De recents travaux ont montre que l'utilisation de MoSi2 dense et nano-organise permettrait de ralentir ce phenomene de "peste". Le defi de produire des materiaux denses et nano-organises peut etre releve par le frittage "flash" reactif sous champ electrique a partir des poudres mecaniquement activees (Mechanically-Activated Spark Plasma Sintering, MASPS). Le controle de la composition et de la microstructure du compose intermetallique MoSi2 necessite de determiner les parametres du frittage SPS (temperature, rampe de montee en temperature, pression uniaxiale appliquee et temps de maintien) lorsque des poudres activees mecaniquement sont utilisees. A l'heure actuelle, par ce procede, les echantillons presentent une phase majoritaire, MoSi2 a plus de 97 %, et une phase secondaire, Mo5 Si3 . Il est donc indispensable de comprendre les transitions de phase qui peuvent avoir lieu au cours d'un frittage impliquant simultanement une consolidation et une reaction SHS. Il a donc ete essentiel de developper un nouveau type d'equipement pour reproduire partiellement ce procede. Ceci a ete realise avec succes en mettant en œuvre une analyse par diffraction des rayons X "in-situ" et en temps reel couplee a une analyse par thermographie IR.
Synthesis and Magnetic Studies of Uniform Iron Nanorods and Nanospheres

The fabrication and magnetic properties of rod-shaped magnetic iron nanoparticles will be presented in the contribution. Recently, the development of uniform magnetic nanoparticles of ∼10 nm became a very important issue in their application to ultrahighdensity magnetic storage devices. 1 Several synthetic approaches including thermal 2 and sonochemical decomposition of organometallic precursors, 3 high-temperature reduction of metal salts, 4
Photoconductivity of vertically aligned ZnO nanoneedle array

A high-density vertically well-aligned ZnO nanoneedle array was fabricated on a ZnO-buffer film on silicon substrates by metal-organic chemical vapor deposition at a growth temperature of 480–500°C. Highly crystalline ZnO nanoneedle arrays showed a strong near-bandedge emission at 380nm in room-temperature photoluminescence. A simple ultraviolet (UV) sensor was fabricated by evaporating a Ag electrode on the ZnO nanoneedle array. The photoresponse results showed very high photocurrent (∼10−4A) from ZnO nanoneedles compared to a single-nanowire sensor (∼10−8A), indicating high sensitivity of the photosensor. It also showed fast rise and decay times in UV-on/off switching measurements.
Structural and Electronic Properties of Poly(9,9-dialkylfluorene)- Based Alternating Copolymers in Solution: An NMR Spectroscopy and Density Functional Theory Study

The structural and electronic properties of three alternating poly(9,9-dialkylfluorene) copolymers, poly[2,7-(9,9-bis(octyl)-fluorene)-alt-benzothiadiazole] (F8BT), poly[2,7-(9,9-bis(2′-ethylhexyl)-fluorene)-alt-thiophene S,S-dioxide] (PFTSO2), and poly[2,7-(9,9-bis(2′-ethylhexyl)-fluorene)-alt-1,4-phenylene] (PFP), containing, respectively, benzothiadiazole (BT), thiophene S,S-dioxide, and phenylene groups, have been investigated and compared to those of the homopolymer poly[2,7-(9,9-bis(2′-ethylhexyl)-fluorene)] (PF2/6). The NMR spectra and corresponding shielding tensors of the 1H and 13C nuclei have been studied in solution and are interpreted by density functional theory (DFT) with complete geometry optimization using the B3LYP functional. Particular emphasis is placed on the conformational behavior and electronic properties in the electronic ground state. In addition, time-dependent DFT is applied to obtain detailed insight into the character of selected excited states. A new TDDFT interpretation is.
A Bench-Scale System to Study the Composting of Organic Wastes

In an investigation of the composting of eucalypt bark, a bench-scale composter was designed to provide strict control over air composition, moisture content, temperature, and mixing. The composter consisted of six 4-L capacity gas-tight units of PVC plastic, each of which was provided with a mixing paddle coupled to a common drive. Natural temperature rise was simulated by having the units immersed in a water bath, with the temperature increased at rates consistent with those observed in large-scale compost heaps. This provided a comparatively inexpensive versatile system, with rates of CO₂, NH₃, CH₄, and H₂S production and O₂ consumption manually monitored by gas chromatography. The reproducibility of the system was as good as the best reported.
Sensibilidade ao rachamento de bagas das videiras 'Concord', 'Isabel' e 'BRS Rúbea'

In order to evaluate the sensitivity of fruit cracking, different laboratory tests were performed in grape berries of the processing varieties Concord, Isabel and BRS Rubea. To determine the cracking index, ripe berries were dipped in distilled water and evaluated every hour during a period of ten hours. Mechanical tests were performed using a texturometer. In compression tests, at the cracking time, pressing pressure, strain energy, maximum force of compression and compression strain were evaluated. With a smaller diameter probe, berries were drilled to the breakup of the skin resulting in maximum force of drilling and drilling strain. In stress relaxation tests the degree of solidity and initial stress decay rate were evaluated. The correlations between the cracking index and mechanical testing were evaluated too. Both the cracking index and mechanical testing pointed to the BRS Rubea as the most resistant to cracking and the Concord cultivar as the most susceptible. Isabel presented intermediate resistance. The cracking index showed strong correlation with the parameters evaluated in the mechanical tests and has good potential for assessing the sensitivity to cracking of different grape cultivars.
Enantioselective Synthesis of Both Enantiomers of Various Propargylic Alcohols by Use of Two Oxidoreductases

The oxidoreductases Lactobacillus brevis alcohol dehydrogenase (LBADH) and Candida parapsilosis carbonyl reductase (CPCR) are suitable catalysts for the reduction of ketones to afford enantiopure sec. alcohols. A broad variety of alkynones (1, 3, and 5) are accepted as substrates and the corresponding propargylic alcohols (2, 4, and 6) are obtained in good yield and excellent enantiomeric excess. By changing the steric demand of the substituents the ee values can be adjusted and even the configurations of the products can be altered.
Protonated Titanates and TiO2 Nanostructured Materials: Synthesis, Properties, and Applications

Tubular and fibrous nanostructures of titanates have recently been synthesized and characterized. Three general approaches (template assisted, anodic oxidation, and alkaline hydrothermal) for the preparation of nanostructured titanate and TiO2 are reviewed. The crystal structures, morphologies, and mechanism of formation of nanostructured titanates produced by the alkaline hydrothermal method are critically discussed. The physicochemical properties of nanostructured titanates are highlighted and the links between properties and applications are emphasized. Examples of early applications of nanostructured titanates in catalysis, photocatalysis, electrocatalysis, lithium batteries, hydrogen storage, and solar‐cell technologies are reviewed. The stability of titanate nanotubes at elevated temperatures and in acid media is considered.
Enantiomeric Separations by Capillary Electrochromatography with Charged Polyacrylamide Gels Incorporating Chiral Selectors

This study examined enantiomeric separation by capillary electrochromatography with charged polyacrylamide gels incorporating chiral selectors, in which electroosmotic flow would be generated. The columns are capillaries filled with a negatively or positively charged polyacrylamide gel, a so-called monolithic stationary phase, incorporating polymeric β -cyclodextrins as chiral selectors. The capillary wall is activated first with a bifunctional reagent to make the resulting gel bind covalently to the inner surface of the fused-silica tubing. Enantiomeric separations of two cationic and a neutral compounds were achieved using negatively charged polyacrylamide gel-filled capillaries incorporating poly β -cyclodextrin and carboxymethyl β -cyclodextrin polymer and a mobile phase of 200 mmol dm^−3 Tris–300 mmol dm^−3 boric acid buffer (pH 9.0). Enantiomeric separations of twelve anionic compounds were also achieved using positively charged polyacrylamide gel-filled capillaries incorporating poly β -cyclodextrin and a mobile phase of 200 mmol dm^−3 Tris–300 mmol dm^−3 boric acid buffer (pH 8.1). High efficiencies of up to 240000 plates m^−1 were obtained. The within-run reproducibilities of retention time and separation factor were good.
Response of Polyelectrolyte Complexes to Subsequent Addition of Sodium Chloride: Time‐Dependent Static Light Scattering Studies

The applications of polyelectrolyte complexes range from large-scale industrial products to special uses in biotechnology and medicine, yet one significant problems is their instability against changes in their environmental conditions, particularly the addition of salts. This concerns the colloidal stability as well as the stability of ionic bindings. Previous work on the effect of sodium chloride revealed that not only additional aggregation, but also complete dissolution may occur, depending on the nature of the polyelectrolyte components used. In these studies, the systems required up to one hour to become stable. Multi-angle static light scattering was used to investigate the processes taking place after the addition of NaC1 to polyelectrolyte complexes (PEC) formed in pure water. PECs were prepared with polymethacrylate as polyanion and poly(diallyldimethylammonium chloride) and a copolymer of this polycatio with 53 mol-% of acrylamide. These systems were chosen because of their interesting, and dissolution at a critical salt concentration. The time-dependence of these effects was studied in detail by static light scattering.
Biodegradation of phenol at high concentration by a novel bacterium: Gulosibacter sp. YZ4

BACKGROUND: A novel bacterial strain, Gulosibacter sp. YZ4, has been isolated from activated sludge. Its application potential for phenol biodegradation has not yet been reported, therefore, in this study, biodegradation tests using strain YZ4 were executed under different conditions. RESULTS: The strain was identified as a new member of the genus Gulosibacter and nominated as Gulosibacter sp. YZ4. Phenol biodegradation tests showed that strain YZ4 could thoroughly biodegrade 1000 mg L−1 phenol across a wide temperature range from 10 to 42 °C and pH range 5 to 11. Degradation of 1000 mg L−1 phenol was not inhibited by the coexistence of p-cresol or quinoline. During phenol degradation, strain YZ4 excreted both phenol hydroxylase and catechol 1,2-dioxygenase to efficiently metabolize phenol. At 36 °C, pH 7.5, strain YZ4 could effectively degrade phenol at concentrations as high as 2000 mg L−1 within 76 h. Haldane's model with the parameters obtained from the experiments could successfully describe the behavior of the phenol biodegradation by the strain YZ4. CONCLUSIONS: The strain YZ4 has a high potential for applications in phenol wastewater treatment in view of its adaptability to temperature and pH fluctuations and great tolerance to other coexistent toxics. Copyright © 2011 Society of Chemical Industry
Morphological Control for High Performance, Solution‐Processed Planar Heterojunction Perovskite Solar Cells

Organometal trihalide perovskite based solar cells have exhibited the highest efficiencies to‐date when incorporated into mesostructured composites. However, thin solid films of a perovskite absorber should be capable of operating at the highest efficiency in a simple planar heterojunction configuration. Here, it is shown that film morphology is a critical issue in planar heterojunction CH3NH3PbI3‐xClx solar cells. The morphology is carefully controlled by varying processing conditions, and it is demonstrated that the highest photocurrents are attainable only with the highest perovskite surface coverages. With optimized solution based film formation, power conversion efficiencies of up to 11.4% are achieved, the first report of efficiencies above 10% in fully thin‐film solution processed perovskite solar cells with no mesoporous layer.
Preparation of multi-nanocrystalline transition metal oxide (TiO2–NiTiO3) mesoporous thin films

Ordered mesoporous TiO2–NiTiO3 thin films, with nickel content x < 0.5, were prepared by dip-coating an acidic solution of hydrolysed transition metal chlorides in controlled humidity, followed by a very careful annealing treatment. These latter treatments were studied by in situ SAXS-WAXS experiments involving synchrotron radiation and TEM analysis. They revealed that the walls can be composed of amorphous, single crystalline or multi crystalline nanoparticles depending on x and the conditions applied during the thermal treatment.
Oxidation Kinetics of Fe(II) in a Eutrophic Swiss Lake

The rate of oxidation of ferrous iron was measured in samples from Lake Greifen, a eutrophic lake in Switzerland. Fe(II) concentrations were followed using an automated flow injection analysis system employing luminol-based chemiluminescence detection of Fe(II). For kinetic studies at pH > 7.8, the system was modified to allow a time resolution of less than 1 s. Oxidation rates were measured in unfiltered samples at 2−2000 nM Fe(II). The pH was varied between 6.8 and 8.3 by bubbling with CO2 and synthetic air. Above pH 7.4, rates were consistent with the rate law determined in pure carbonate systems. Between pH 6.8 and pH 7.3, however, the apparent rate was independent of pH. This surprising finding may be explained by some naturally occurring (organic, colloidal, or surface) ligand(s) that accelerate the oxidation of Fe(II). The relative importance and pH dependence of the direct reaction with O2 in comparison to that with H2O2 was determined, and the enhancement of the overall rate was attributed to the.
A Reversed-Phase HPLC Method For Determining Camptothecin In Plasma With Specificity For the Intact Lactone Form of the Drug

Abstract Camptothecin is a pentacyclic indole alkaloid with a terminal α-hydroxy-δ-lactone ring, which in aqueous media at physiological pH, exists in equilibrium with the dissociated open-lactone carboxylate. the rate of equilibration between the two components is slow enough to permit their separation by reversed-phase HPLC. Selective determination of the intact lactone form of the drug was achieved by direct analysis of plasma samples immediately upon deproteinization with a solution of the internal standard in methanol chilled to −70°C. Acidification of the sample to pH 2 with perchloric acid prior to protein precipitation effected complete lactonization of the carboxylate and, therefore, provided a measure of total drug levels. Plasma concentrations of the carboxylate may be calculated from the difference between total drug and intact lactone determinations. Chromatography was performed on a 5 μm Ultrasphere ODS column (4.6 mm × 25 cm) preceded by a 1.5 cm RP-18 Brownlee Guard column with an eluent c.