Optically active transition metal complexes: LVI. Preparation and Stereochemistry of (+)578- and (-)578-(n-C6H6RuX(Me) [Ph2PNHCH(Me) (Ph)], where x = Cl,SnCl3

The synthesis and resolution of (+)₅₇₈- and (-)₅₇₈-(η-C₆H₆)RuCl(Me) [Ph₂PNHCH(Me) (Ph)] is described. Insertion of anhydrous SnCl₂ into the Ru-Cl bond yielded (+)₅₇₈- and (-)₅₇₈-(η-C₆H₆)RuSnCl₃(Me)-[Ph₂PNHCH(Me) (Ph)], the stereoselectivity of which is dependent on the reaction conditions. All the new complexes were found to be configurationally stable in a wide variety of solvents up to 60°C./     

The electronic structure of heteroaromatic molecules; non-empirical calculations and photoelectron spectra for the isomeric-thiazoles and -thiadiazoles

The He(I) and MgKα photoelectron spectra are reported for the isomeric thiazoles, and He(I) spectra for the isomeric-thiadiazoles. Marked fine structure is apparent on some of the spectra. Comparison with the earlier spectra for thiophen and the azoles, and with ab initio calculations for the seven compounds, has led to assignment of the spectra. The calculations suggest that 1,3,4-thiadiazole is less aromatic than the other title compounds. As expected, the role of the 3d_s orbitals is found to be that of polarisation functions for all of the compounds, but inclusion of these orbitals leads to much better agreement with the observed dipole moments, both in magnitude and direction.     

Formation inattendue de digermane optiquement actif au cours de la reaction de substitution des germanes par le chlorure de benzyl-magnesium active par les complexes du nickel

An optically active digermine is obtained in the reaction of PhCH₂ MgCl (activated by a Ni^II complex) with α-NpPhMeGeH. This observation indiates the formation of a GeMgX reagent ant its activation by Ni^II, allowing cleavage of the Gebond with retention of configuration.     

M. S. Tswett and the discovery of chromatography II: Completion of the development of chromatography (1903–1910)

Summary In this, the second part of our review we continue the discussion of the activities of M. S. Tswett related to the development of chromatography. We shall deal here with his activities in Warsaw from 1903 onwards, resulting in his fundamental twin papers of 1906 and his book of 1910, summarizing all his activities related to the investigation of plant pigments and to the development of chromatography. Finally, a few special questions related to Tswett's work shall be discussed.For Part I, seeChromatographia 35, 223 (1993). References are numbered through.     

M. S. Tswett and the discovery of chromatography I: Early work (1899–1903)

Summary On the occasion of the 90th anniversary of the Warsaw lecture of M. S. Tswett representing the first report on the chromatographic technique, this two-part article outlines the evolution of the method. This part deals with Tswett's early work in 1899–1901 and his research in 1901–1903 leading to the lecture at Warsaw. The second part will deal with the fundamental twin papers of 1906, with his book of 1910, summarizing all his activities related to the investigation of plant pigments and to the development of chromatography, and with a few special questions related to Tswett's scientific activities in this field.Part II of this article will be published in the next month's issue ofChromatographia.     

Spectrophotometric Study on the Interaction between Arsenazo M and Proteins

Dye binding protein assays are commonly used in biochemical and clinical laboratories, and the reaction mechanism is still under investigation1-2. In this paper, the interaction of Arsenazo M with serum proteins was studied. Procedure In most experiments, 1.20 mL of Arsenazo M (5.0010-4 mol/L), 2.0 mL of C-L buffer solution, 3.0 mL alcohol and certain amount of protein standard solutions or samples were added to 10 mL volumetric flasks, then diluted to mark with water, and mixed thor…     

Control of release kinetics of macromolecules from polymers

Internal and external means for controlling the release rates of large molecules, such as proteins, from ethylene—vinyl acetate copolymer matrices are presented. Internal approaches include alteration of the polymer—drug design, such as changing drug loading and particle size, coating the matrix, or altering matrix geometry. Kinetic and microstructural analyses are discussed. Applications of these polymeric systems, for instance, in delivery of insulin for diabetes, improved immunization procedures, and in developing bioassays for informational macromolecules are considered. In addition, a new approach for externally controlling release rates of drugs using magnetism has been developed. Until now, drug delivery systems were capable of delivering drugs at either constant or decreasing rates. We sought a system that permitted delivery of increased doses on demand, and achieved this by incorporating magnetic particles and drugs into polymeric matrices. Drug release rates can then be increased by an appropriate application of an external magnetic field. Over a five-day period, the magnetic field was applied ten times and drug release rates increased by up to 100% each time. Initial results indicate that this system does not cause tissue damage.     

Surface structure and reaction performances of highly dispersed and supported bimetallic catalysts

Surface structures of Pt-Sn and Pt-Fe bimetallic catalysts have been investigated by means of Mssbauer spectroscopy, Pt-L_Ⅲ-edge EXAFS and H_2-adsorption. The results showed that the second component, such as Sn or Fe, remained in the oxidative state and dispersed on the γ-Al_2O_3 surface after reduction, while Pt was completely reduced to the metallic state and dispersed on either the metal oxide surface or the γ-Al_2O_3 surface. By correlating the distribution of Pt species on different surfaces with the reaction and adsorption performances, it is proposed that two kinds of active Pt species existed on the surfaces of both catalysts, named M_1 sites and M_2 sites. M_1 sites are the sites in which Pt directly anchored on the γ-Al_2O_3 surface, while M_2 sites are those in which Pt anchored on the metal oxide surface. M_1 sites are favorable for low temperature H_2 adsorption, and responsible for the hydrogenolysis reaction and carbon deposition, while M_2 sites which adsorb more H_2 at higher tem     

M. S. Tswett and the 1918 Nobel Prize in Chemistry

Summary The general recognition of M. S. Tswett and his achievements are discussed, with special emphasis to his nomination for the 1918 Nobel Prize in Chemistry.     

PERIODIC, SOLITARY AND DISCONTINUOUS PERIODIC SOLUTION OF NONLINEAR WAVES IN THE ATMOSPHERE AND THEIR EXISTENCE (Ⅱ)——ON THE POSSIBILITY OF TAYLOR EXPANSION, M CRITERION AND NONLINEAR WAVE SPEED FORMULAS

In this part, the nonlinear wave speed formulas are discussed. Because the nonlinear wave speed formulas are relative to wave form, we introduce a non-dimensional quantity M, which describes the nonlinear wave pattern and qualitatively determines the nonlinear degree. It is called M criterion. The wave speed formulas of the nonlinear Rossby wave and the nonlinear inertial gravity wave are also discussed. The wave speed of the former decreases with the growth of the amplitude but that of the latter is on the opposite. Furthermore we have also discussed the problems which must be taken note of in applying the Taylor expansion as we solve the approximate solution of nonlinear waves.     

2,2′-Dihydroxybenzophenone thiosemicarbazone as a spectrophotometric reagent for the determination of copper,cobalt, nickel,and iron trace amounts in mixtures without previous separations

2,2′-Dihydroxybenzophenone thiosemicarbazone forms complexes with Cu(II) (λ_max = 385 nm, ? = 8.60 × 10³ liter · mol^?1 · cm^?1); Ni(II) (λ_max = 380 nm, ? = 15.4 × 10³ liter · mol^?1 · cm^?1); Co(II) (λ_max = 380 nm, ? = 12.3 × 10³ liter · mol^? · cm^?1); and Fe(III) (λ_max = 365 nm, ? = 7.9 × 10³ liter · mol^?1 · cm^?1) and have been applied to the analysis of these metal ions in binary, ternary, and quaternary mixtures. The determination procedures are based exclusively on the different pH values of the formation complexes, hence the extraction step is not necessary.     

现代固态有机化学之父——Gerhard M.J.Schmidt

本文主要介绍了GerhardM.J.Schmidt教授的生平、代表性的科研工作及其意义、影响和应用,从中展现出他的优秀品质、治学精神、杰出成就以及影响力。Schmidt教授少年早慧,求学艰辛,天赋独特,痴迷科学,为科学事业奋斗终身,在多个领域都有着卓越的成就,其中以固态有机化学领域最具代表性。他在科研的同时还担任诸多行政职务,为魏茨曼研究所、以色列乃至全世界的科学发展做了许多贡献。     

Green synthesis and chemical characterization of silver nanoparticles obtained using Allium saralicum aqueous extract and survey of in vitro antioxidant,cytotoxic, antibacterial and antifungal properties

Allium saralicum R.M. Fritsch has been used in Iranian traditional medicine as a remedial supplement for microbial diseases. This paper reports the green synthesis, chemical characterization and antioxidant, cytotoxic, antibacterial and antifungal properties of silver nanoparticles obtained using aqueous extract of A. saralicum leaves. In this synthesis, no surfactants or stabilizers were used. For characterization, UV–visible spectroscopy, transmission electron microscopy, X‐ray diffraction, energy‐dispersive X‐ray spectroscopy and field emission scanning electron microscopy were used. 2,2‐Diphenyl‐1‐picrylhydrazyl was used in experiments to assess the antioxidant potential of the silver nanoparticles, which revealed an impressive prevention in comparison with butylated hydroxytoluene. The synthesized silver nanoparticles at low doses (1–250 μg dl^?1) did not show marked cytotoxic activity (against cervical cancer cells (Hela), breast cancer cells (MCF‐7) and human embryonic kidney cells (HEK‐293)). Agar diffusion tests were applied to determine the antibacterial and antifungal characteristics. Compared with all standard antimicrobials, the silver nanoparticles showed higher antibacterial and antifungal activities (p ≤ 0.01). Also, the silver nanoparticles inhibited the growth of all bacteria and fungi at concentrations of 31–250 μg ml^?1, and destroyed them at concentrations of 31–500 μg ml^?1 (p ≤ 0.01). Because the silver nanoparticles obtained using aqueous extract of A. saralicum leaves have antioxidant, non‐cytotoxic, antifungal and antibacterial potentials, they can be used as a medical supplement or drug.     

High—Speed Analyzing PCR Products of M.tuberculosis Genome Stained by Ethidium Bromide on Microchip Gel Electrophoresis

The technique of microchip gel electrophoresis(MCGE) was used to analyze the polymerase chain reaction (PCR) products of M.tuberculosis Genome stained by ethidium bromide,The electrophoretic Process was completed within 3-4 min and the results show that the technique of microchip electrophoresis is a high-speed and high-sensitivity analyzing method.     

Allosteric Modulators of the Tertiary Alkanebisamino-Type. Variation of the Substitution of the Middle Chain Nitrogens

Summary. Synthesis pathways of high flexibility for variously substituted alkanebisamine-type allosteric modulators of muscarinic receptors capable of passing the blood-brain barrier were developed starting either from N,N-(hexane-1,6-diyl)bistosylamide or adipic acid chloride. Pharmacological evaluation of some representative compounds revealed the allosteric potency to fall in a submicromolar range.     

A Novel and sensitive spot-test for m-dinitroaromatics and their derivatives with sodium sulphite and dimethylsulphoxide

Sodium sulphite has been used for a very sensitive characterization of m-dinitroaromatics and their derivatives, with dimethylsulphoxide as solvent.     

Anti-Cancer and Medicinal Potentials of Moringa Isothiocyanate

Moringa oleifera (M. oleifera), which belongs to the Moringaceae family, is a common herb, rich in plant compounds. It has a variety of bioactive compounds that can act as antioxidants, antibiotics, anti-inflammatory and anti-cancer agents, etc., which can be obtained in different body parts of M. oleifera. Isothiocyanates (ITCs) from M. oleifera are one class of these active substances that can inhibit cancer proliferation and promote cancer cell apoptosis through multiple signaling pathways, thus curbing cancer migration and metastasis, at the same time they have little adverse effect on normal cells. There are multiple variants of ITCs in M. oleifera, but the predominant phytochemical is 4-(α-L-rhamnosyloxy)benzyl isothiocyanate, also known as moringa isothiocyanate (MIC-1). Studies have shown that MIC-1 has the possibility to be used clinically for the treatment of diabetes, neurologic diseases, obesity, ulcerative colitis, and several cancer types. In this review, we focus on the molecular mechanisms underlying the anti-cancer and anti-chronic disease effects of MIC-1, current trends, and future direction of MIC-1 based treatment strategies. This review combines the relevant literature of the past 10 years, in order to provide more comprehensive information of MIC-1 and to fully exploit its potentiality in the clinical settings.