Kinetic model and mechanism for selective hydrogenation of acetylene alcohols

A complex approach to the development of kinetic models in terms of the joint kinetic and physicochemical methods is suggested. To establish kinetic models for the hydrogenation of C₅, C₁₅ and C₂₀ acetylene alcohols on a modified Pd/Al₂O₃ (0.5% Pd) catalyst, the kinetics of their selective hydrogenation and the adsorption of their components have been studied.

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- . C₅, C₁₅, C₂₀ Pd/Al₂O₃ (0,5% Pd), .

     

Repurposing homeopathic drug Lachesis 200C as an anticancer activity: In vitro and in ovo study

Cancer is one of the most critical health burdens with leading causes of death worldwide. Homeopathy is one of the complementary and alternative therapies, which utilizes venoms and toxins in ultra-high dilutions for therapeutics. In the present investigation, we used the homeopathy Lachesis 200C drug to study anticancer activity on the mouse fibroblast cells [L929], human prostate cancer cells [PC3], and in chick embryo model. Treating with Lachesis 200C showed 91.10% and 37.47% reduction in cell viability in L929 and PC3 respectively as compared to control by MTT assay. In the chick embryo model Lachesis 200C (dose of 50% and 100%) treatment resulted in antiangiogenic activity as compared to the control group. There was an antiproliferative and cytotoxic activity of Lachesis 200C in PC3 and L929 ​cell lines. Lachesis 200C inhibited the growth of PC3 cells. In the in vivo studies, Lachesis 200C treated chicks showed a significant decrease in or complete disappearance of blood vessels from chorioallantoic membrane (CAM) areas compared to control. The findings indicate that the level of angiogenesis was dramatically decreased by Lachesis 200C. Lachesis 200C showed the potential to act as an anticancer agent. Further studies with Lachesis200 could lead to a potential anticancer agent.     

On the mechanism of propylene epoxidation catalyzed by molybdenum naphthenate

The mechanism of the catalytic epoxidation of propylene with -phenylethyl hydroperoxide has been investigated. The epoxidation step is a molecular interaction between propylene and a complex formed from hydroperoxide and catalyst, while part of side products is formed in free radical reactions. This mechanism is valid for the kinetics of both epoxidation and catalytic decomposition of hydroperoxide.

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ESR study of Fe3+-zeolites

The ESR signal at g=4.3, recently attributed to Fe³⁺ which substitute Si, Al in the lattice of glasses and zeolites, can also characterize the charge balancing Fe³⁺ Td complexes in cavities of Fe³⁺ HNaY zeolites.

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g=4,3, Fe⁺³, Si, Ql , Td Fe⁺³ Fe⁺³ HNaY.

     

An efficient method to synthesize HMX by nitrolysis of DPT with N_2O_5 and a novel ionic liquid

A novel polyethylene glycol(PEG)-200-based dicationic acidic ionic liquid(PEG200-DAIL)was used to synthesize HMX from DPT by nitrolysis with N2O5.It was found that either N2O5 or PEG200-DAIL could improve the yield.Furthermore,the combined use of PEG200-DAIL and N2O5 could increase the yield of HMX to 64%with the used quantity of HNO3 decreased.dramatically     

Dual-functional hydrogen-bonded organic frameworks for aniline and ultraviolet sensitive detection

A novel hydrogen-bonded organic frameworks (HOFs) FJU-200 has been constructed from N,N'-bis(5-isophthalic acid)naphthalimide (H₄L). FJU-200 has a good dual-function of aniline and ultraviolet detection. FJU-200 is the first case of HOF with dual sensing of visual color changes and photoluminescence quenching for aniline detection, and the detection limit of aniline can reach 5.5 × 10⁻⁴ mol/L. Under ultraviolet FJU-200 will rapidly change from light yellow to rustic brown, which makes it possible to use FJU-200 to achieve minute-level ultraviolet detection. Moreover, for more convenient use, FJU-200 test papers are prepared. Using them, convenient and fast aniline or ultraviolet detection can be realized. The single-crystal X-ray structures show that compared with the original FJU-200, both PhNH₂@FJU-200 and UV-FJU-200 have larger pore sizes, and the dihedral angles of the H₂L²⁻ in framework has been changed.     

Human Serum Albumin−Gold Nanoparticle Based Impedimetric Sensor for Sensitive Detection of miRNA-200c

Here, human serum albumin conjugated gold nanoparticles (HSA−AuNPs) were synthesized by a simple route to develop an impedimetric sensor for miRNA-200c detection based on a selective oligo-hybridization process without any labeling. The synthetic DNA capture probe for miRNA-200c was decorated onto the HSA−AuNPs modified pencil graphite electrodes. Impedimetric signals were monitored after the hybridization process between the DNA probe and target miRNA-200c. HSA−AuNPs adsorption time, incubation time of the capture probe and hybridization time-temperature were optimized. The proposed miRNA-200c biosensor demonstrated proper sensitivity and selectivity, low detection limit (1.13 fM), good reproducibility and simple direct detection of miRNA-200c in serum.     

Immunochemical analysis of a photoreceptor protein using anti-IP3 receptor antibody in the unicellular organism, Blepharisma

The blepharismin-200 kD protein complex of the ciliated protozoan Blepharisma is a novel type of photosensor responsible for the step-up photophobic response of the cell. In immunoblotting assays, the 200 kD protein is weakly cross-reacted with anti-inositol triphosphate receptor antibody (anti-IP3 R antibody). Indirect immunofluorescence assays show that the pigment granules in which the blepharismin-200 kD protein complex is localized are labelled by anti-IP3 R antibody. When the anti-IP3 R antibody or antisense oligonucleotide for IP3 receptor is introduced into the living cells of Blepharisma, both the photosensitivity of the cells and content of blepharismin-200 kD protein are reduced. The results suggest that the photoreceptor 200 kD protein is possibly an IP3 receptor-like protein.     

Improving sample representativeness in environmental studies: a major component for the uncertainty budget

For environmental quality assessment, INAA has been applied for determining chemical elements in small (200 mg) and large (200 g) samples of leaves from 200 trees. By applying the Ingamells’ constant, the expected percent standard deviation was estimated in 0.9–2.2% for 200 mg samples. Otherwise, for composite samples (200 g), expected standard deviation varied from 0.5 to 10% in spite of analytical uncertainties ranging from 2 to 30%. Results thereby suggested the expression of the degree of representativeness as a source of uncertainty, contributing for increasing of the reliability of environmental studies mainly in the case of composite samples.     

Molecular dynamics and phase behavior of polystyrene/poly(vinyl methyl ether) blend in the presence of nanosilica

The variation of phase morphology, critical temperature of demixing, and molecular dynamics for polystyrene/poly(vinyl methyl ether)(PS/PVME) blends induced by hydrophilic nanosilica(A200) or hydrophobic nanosilica(R974) was investigated. With the phase separation of blend matrix, A200 migrated into PVME-rich phase due to strong interaction between A200 and PVME, while R974 moved into PS-rich phase. The thermodynamic miscibility and concentration fluctuation during phase separation of blend matrix were remarkably retarded by A200 nanoparticles due to the surface adsorption of PVME on A200, verified by the correlation length ξ near the critical region from rheological measurement and the weakened increment of reversing heat capacity(ΔC_p) during glass transition via modulated differential scanning calorimetry(MDSC). The restricted chain diffusion induced by nanosilica still occurred despite no influence of A200 and R974 on the segmental dynamics of homogenous blend matrix. The interactions between nanosilica and polymer components could restrict the terminal relaxation of blend matrix and further manipulate their phase behavior.     

Determination of monoclonal antibody production in cell culture using novel microfluidic and traditional assays

This study compares microfluidic technology (Protein 200 LabChip Assay kit, Agilent 2100 Bioanalyzer, referred to here as Protein 200) to the traditional approach for protein analysis, one-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), for the sizing and quantification of immunoglobulin G (IgG) in hybridoma cell cultures. Internal references differ between each method: purified IgG was used alone in SDS-PAGE while myosin (the upper marker) was added to each sample in Protein 200. The IgG used here were produced in cultures propagated in either a serum-free or a serum-containing medium. With serum-containing samples, there was a significant difference in the IgG concentrations (p < 0.05) between SDS-PAGE and Protein 200. The concentration determined by SDS-PAGE was significantly higher (> 30%) than by Protein 200 or by high-pressure liquid chromatography (HPLC) because the large amounts of serum albumin in the samples affect the accuracy of SDS-PAGE. Protein 200 can determine size similarly to SDS-PAGE in serum-free samples (standard error of the mean, SEM, < 1%, 95% confidence < +/-1%), unlike in serum-containing samples. The Protein 200 assay was more effective than the traditional one-dimensional SDS-PAGE in determining concentration and size of IgG in cell culture samples and it provided a miniaturized and convenient platform for rapid analysis.     

Analyses of structure of photoreceptor organelle and blepharismin-associated protein in unicellular eukaryote Blepharisma

In the ciliated protozoan Blepharisma, step-up photophobic response is believed to be mediated by a novel type of photosensory pigment known as "blepharismins" (BL) that are contained in the pigment granules located just beneath the plasma membrane. We examined the ultrastructure of the pigment granules by freeze-fracture and thin-section electron microscopy and proposed a schematic diagram showing the granules' three-dimensional inner membranous structure. Some of the BL are suggested to be associated with 200 kDa membrane protein. High-pressure liquid chromatography analysis of pigment species associated with 200 kDa protein obtained from blue forms of Blepharisma (oxyblepharisma) revealed that the 200 kDa protein was associated with five types of oxyblepharismin. The fluorescence intensity was increased when the pigments were dissociated from the 200 kDa protein. The result supports the hypothesis that the pigment-200 kDa complex is able to transduce light energy into signals mediating the photobehavior of Blepharisma.     

Sephacryl Gels: Physical Properties and Evaluation of Performance in Gel Filtration

Abstract

Sephacryl is a gel filtration medium composed of allyl dextran and N,N'-methylene bisacrylamide. Sephacryl S-200 SF has a fractionation range similar to that of Sephadex G-150. Sephacryl S-300 SF has a fractionation range more similar to Sephadex G-200 or Sepharose 6B, with an exclusion limit for globular proteins of about 10⁶ daltons. In typical applications, excellent resolution of protein mixtures was obtained at flow rates up to 30 cm/hr. Good correlation was established between elution volumes of proteins and their molecular weights. The gels contain few ionic groups, as determined by titration. Studies using Sephacryl S-200 at different pH values indicate that, above pH 3, protein does not interact with Sephacryl S-200 at moderate ionic strengths. However, below pH 3, protein binds strongly to the gel through hydrophobic interactions and/or hydrogen bonding. Most separations using Sephadex G-150 or Sephadex G-200 could be duplicated using Sephacryl S-200 or S-300 at much higher flow rates.     

聚乙二醇类单体的制备及其生物相容性测定

聚乙二醇类单体是合成功能性高分子材料的重要单体。直接酯化法是合成此类单体的主要方法,但利用该法所制备产物的双键保留率偏低。针对这一问题,本文以聚乙二醇单甲醚-200和丙烯酸为原料,在携水剂存在的同时,向反应体系中引入变色硅胶,提高了直接酯化法去除生成水的效率,制备出了高双键保留率、高产率的聚乙二醇单甲醚-200丙烯酸酯(MPEGA-200),并采用红外光谱、1H NMR对产物进行了表征,采用过氧化氢酶评价了产物的生物相容性。通过正交实验确定了最佳合成条件为:醇酸摩尔比1:2,催化剂对甲苯磺酸和阻聚剂对苯二酚加量均为2%,变色硅胶占醇酸总质量的12%,携水剂石油醚60~90加量为18%,反应温度120℃,反应时间6h。在此条件下,酯化率可达95.47%,MPEGA-200的双键保留率为95.45%,产率为87.68%。另外,本文还采用单因素法研究了各反应条件对酯化反应的影响规律。     

High-temperature hydrothermal synthesis of magnetically active, ordered mesoporous resin and carbon monoliths with reusable adsorption for organic dye

Magnetically active, thermally stable, and ordered mesoporous resin (MOMR-200) and carbon (MOMC-200) monoliths were prepared by one-pot hydrothermal synthesis from resol, copolymer surfactant, and iron cations at high-temperature (200 ^°C), followed by calcination at 360 ^°C and carbonization at 600 ^°C. X-ray diffraction results show that both MOMR-200 and MOMC-200 have ordered hexagonal mesoporous symmetry, and N₂ isotherms indicate that these samples have uniform mesopores (3.71, 3.45 nm), high surface area (328, 621 m²/g) and large pore volume (0.31, 0.43 cm³/g). Transmission electron microscopy shows that iron nanoparticles, which are superparamagnetic in nature, are dispersed in the network. More importantly, the high temperature (200 ^°C) products exhibit much better stability than the samples synthesized at low temperature (100 ^°C). Interestingly, MOMC-200 has higher adsorption capacity for organic dyes when compared with commercial adsorbents (activated carbon and macroporous resin: XAD-4). Combining the advantages such as magnetically active, thermally stable networks, ordered and open mesopores, high surface area, large pore volume, adsorption of pollutants in water and desorption in ethanol solvent, MOMC-200 is potentially important for water treatments.     

Promotion effect of adsorbed water/OH on the catalytic performance of Ag/activated carbon catalysts for CO preferential oxidation in excess H2

Activated carbon (AC) supported silver catalysts were prepared by incipient wetness impregnation method and their catalytic performance for CO preferential oxidation (PROX) in excess H₂ was evaluated. Ag/AC catalysts, after reduction in H₂ at low temperatures (≤200 °C) following heat treatment in He at 200 °C (He200H200), exhibited the best catalytic properties. Temperature-programmed desorption (TPD), X-ray diffraction (XRD) and temperature-programmed reduction (TPR) results indicated that silver oxides were produced during heat treatment in He at 200 °C which were reduced to metal silver nanoparticles in H₂ at low temperatures (≤200 °C), simultaneously generating the adsorbed water/OH. CO conversion was enhanced 40% after water treatment following heat treatment in He at 600 °C. These results imply that the metal silver nanoparticles are the active species and the adsorbed water/OH has noticeable promotion effects on CO oxidation. However, the promotion effect is still limited compared to gold catalysts under the similar conditions, which may be the reason of low selectivity to CO oxidation in PROX over silver catalysts. The reported Ag/AC-S-He catalyst after He200H₂00 treatment displayed similar PROX of CO reaction properties to Ag/SiO₂. This means that Ag/AC catalyst is also an efficient low-temperature CO oxidation catalyst.     

Synthesis of potential antagonists to amino acids in the quinoline series

The following potential antagonists to amino acids were synthesized: -(6-quinolyl)--alanine, -(8-quinolyl)--alanine, and -(2-phenyl-4-carboxy-6-quinolyl)--alanine.     

氯硝柳胺及其衍生物与钥孔戚血蓝蛋白的相互作用

以氯硝柳胺为原料合成了聚乙二醇200基氯硝柳胺. 采用荧光光谱、同步荧光光谱、紫外吸收光谱和圆二色谱研究了氯硝柳胺及其衍生物与钥孔戚血蓝蛋白(KLH)的相互作用. 结果表明, 两种药物分子对KLH的荧光猝灭机制属于静态猝灭; 由Lineweaver-Burk方程计算出不同温度下结合常数K, 但是聚乙二醇200基氯硝柳胺与KLH的作用相对较弱; 由Van′t Hoff方程计算出ΔH和ΔS平均值, 结合力主要为静电作用力; 热力学函数计算结果表明, 氯硝柳胺及其衍生物与KLH的作用过程是一个熵增加、Gibbs自由能降低的自发分子间作用过程; 根据Förster非辐射能量转移机制求得给体与受体间的结合距离r均小于7 nm; 同步荧光光谱表明, 氯硝柳胺及其衍生物能够被血蓝蛋白存储和转运, 但结合时对蛋白构象有一定影响; 圆二色谱测得加入两种药物后, KLH的α-螺旋含量均降低, 二级结构发生改变. 通过比较氯硝柳胺及其衍生物与KLH的相互作用, 初步探讨了分子结构与其结合能力之间的联系.     

The quantitative detection of estrogens and antithyroid drugs by thin-layer and high performance thin-layer chromatography in animal tissue (author's transl)]

Methods of thin-layer chromatography (TLC) and high-performance thin-layer chromatography (HPTLC) were developed for the determination of estrogens and antithyroid drugs in extracts of animal tissues. TLC proved to be suitable for quantities in the range of 200-2000 ng, with a detection limit of 50-200 ng, HPTLC in the range of 10-200 ng, showing calibration curves of good linearity even in extracts. By HPTLC better detection limits, better separation and faster ascending could be achieved than by TLC.     

Efficiency of radiation-induced main-chain scission of poly (methyl methacrylate) depends on the irradiation temperature because of coexisting monomer

Effect of irradiation temperature on the main-chain scission of poly (methyl methacrylate) (PMMA) caused by γ-irradiation was studied by means of gel permeation chromatography and ESR spectroscopy. Although no temperature dependency was observed on the scission efficiency for purified PMMA, the efficiency for crude or monomer-doped purified PMMA was decreased by decreasing the temperature below ca. 200 K. Above 200 K the efficiency was constant and did not depend on the purity of PMMA. ESR study of the irradiated PMMA revealed that the suppression of the scission below 200 K is induced by the addition of methyl methacrylate monomer to primary radical species, which otherwise cause the main-chain scission by warming the polymer above 200 K. The primary radical generated above 200 K immediately converts to the scission-type ? CH₂ ? ?(CH₃) COOCH₃ radical through the β-scission of the polymer main chain, so that the efficiency of the scission does not depend on both the impurity and the irradiation temperature. © 1994 John Wiley & Sons, Inc.