Hereditary DNA alterations

Mutations and recombinations are hereditary alterations of DNA, which is found mainly in the chromosomes of cells. They can occur spontaneously and they can be induced by high energy radiation or by chemicals. This article considers the developments following the discovery of the DNA structure that have led to a molecular explanation of point mutations, of large chromosome alterations, and of recombination. In conclusion, consequences for human society are drawn from the knowledge gained.     

The biochemistry of sphingolipid storage diseases.

Sphingolipids are components of animal membranes that are made up of a hydrophobic ceramide and a hydrophilic moiety (phosphorylcholine, oligosaccharides or their derivatives). Several enzymes are required for the step-by-step degradation of the sphingolipids. If one of these enzymes is deficient or totally lacking, then its substrates accumulate in the body and cause severe damage, especially when storage occurs in the nervous system. The enzyme defects are inherited in a recessive manner.     

Some aspects of chemical mutagenesis in man and in Drosophila

Since mutations produced by chemicals are, like spontaneous mutations, generally transmitted by recessive factors, i. e. as they are only expressed after several generations, depending on the circumstances, it is extremely difficult to trace the true cause of such mutations, which are almost always unfavorable. However, it is possible to study the mutagenic action of chemicals in test systems, e.g. in Drosophila in vivo or in human chromosomes in vitro. Alkylating agents which damage DNA indirectly have a particularly severe mutagenic action. The present progress report contains, among other things, a comprehensive list of substances that produce aberrations in human chromosomes.     

Isoconversional kinetic analysis of stoichiometric and off-stoichiometric epoxy-amine cures

The curing reaction of stoichiometric and off-stoichiometric diglycidyl ether of bisphenol A (DGEBA) and 1,3-phenylene diamine (m-PDA) mixtures was studied by differential scanning calorimetry, thermogravimetric analysis and rheological measurements. In order to highlight the side reactions such as etherification and homopolymerization, the neat DGEBA and DGEBA/DMBA (N,N-dimethylbenzylamine) mixture were examined. The classical model-fitting and the advanced isoconversional methods were used to determine the activation energy of the different reactions. The advanced isoconversional method leads to a good agreement between isothermal, nonisothermal and rheological results. The effective activation energies of primary amine epoxy reaction, etherification and homopolymerization were estimated to about 55-60, 104 and 170 kJ mol⁻¹, respectively.     

微量元素与遗传性代谢病

综合了有关研究，对微量元素与遗传性代谢病之间的关系，从发病原因和治疗机理方面进行了分析，并对微量元素和基因的调控进行了初探，认为从非遗传的调控机制入手，研究微量元素的代谢机理，可能在遗传性代谢病发生和治疗上具有目前尚无法预见的潜力。     

肺部疾患与微量元素

综述了肺部疾病与微量元素之间的关系。     

Biomolecular modeling: Goals, problems, perspectives

Computation based on molecular models is playing an increasingly important role in biology, biological chemistry, and biophysics. Since only a very limited number of properties of biomolecular systems is actually accessible to measurement by experimental means, computer simulation can complement experiment by providing not only averages, but also distributions and time series of any definable quantity, for example, conformational distributions or interactions between parts of systems. Present day biomolecular modeling is limited in its application by four main problems: 1) the force-field problem, 2) the search (sampling) problem, 3) the ensemble (sampling) problem, and 4) the experimental problem. These four problems are discussed and illustrated by practical examples. Perspectives are also outlined for pushing forward the limitations of biomolecular modeling.     

Clinical,Nutritional, and Functional Evaluation of Chia Seed-Fortified Muffins

Health-protective functional foods are gaining popularity in the world of nutrition because they promote excellent health while decreasing pharmaceutical burdens. Chia seeds (CS) (Salvia hispanica L.), the greatest vegetative source of α-linolenic acid, bioactive proteins, and fibers, are among the top unconventional oilseeds shown to have bounteous benefits against various non-communicable diseases. Purposely, this study was designed to integrate roasted CS powder into white-flour-based ordinary bakery goods to improve their nutritional and nutraceutical profiles. CS efficacy in normal and hyperlipidemic Sprague-Dawley rats resulted in mitigating blood glucose, triglycerides, total cholesterol, and low-density lipoprotein cholesterol while elevating high-density lipoprotein cholesterol, hematocrit, hemoglobin, red blood cell counts, and platelets. The nutritional profiling of chia-fortified muffins indicated significant increases of 47% in fat, 92% in fiber, 15% in protein, and 62% in minerals. The farinographic experiments of CS-blends revealed generally improved dough quality features with a significant rise in the degree of softening as fortification levels increased. A marketable recipe for CSF-muffins with several degrees of fortification demonstrated a significant rise in fat, 92% rise in fiber, 15% rise in protein, and 62% rise in minerals. Sensorial evaluation by trained taste panelists revealed a maximum appraisal of the 15% chia-fortified muffins due to aroma, appearance, and overall acceptability, and were forwarded for being acceptable for commercialization.     

Amyloid Cross-Seeding: Mechanism,Implication, and Inhibition

Most neurodegenerative diseases such as Alzheimer’s disease, type 2 diabetes, Parkinson’s disease, etc. are caused by inclusions and plaques containing misfolded protein aggregates. These protein aggregates are essentially formed by the interactions of either the same (homologous) or different (heterologous) sequences. Several experimental pieces of evidence have revealed the presence of cross-seeding in amyloid proteins, which results in a multicomponent assembly; however, the molecular and structural details remain less explored. Here, we discuss the amyloid proteins and the cross-seeding phenomena in detail. Data suggest that targeting the common epitope of the interacting amyloid proteins may be a better therapeutic option than targeting only one species. We also examine the dual inhibitors that target the amyloid proteins participating in the cross-seeding events. The future scopes and major challenges in understanding the mechanism and developing therapeutics are also considered. Detailed knowledge of the amyloid cross-seeding will stimulate further research in the practical aspects and better designing anti-amyloid therapeutics.     

Prion疾病与生物无机化学

介绍了除病菌、病毒以外的第三种病原体－－病蛋白Ｐｒｉｏｎ。这种病原蛋白的本质是正常蛋白的异常折叠,因此又被称为蛋白分子的“构象病”。还介绍了这种病蛋白的可能致病机理。铜离子对这种病蛋白生成的重要作用,充分显示了生物无机化学这门新兴学科的重要性和前沿性。     

Evaluation of strain in heterosiliranes: Systematics,surprises, and problems

A series of different isodesmic and homodesmic reactions defining strain energies in 3-membered rings are described and discussed. One isodesmic and one homodesmic reaction are applied numerically with the purpose of estimating strain in heterosiliranes including second-row and third-row heteroatoms. All molecules involved are optimized using SCF /6-31G **, and energies are calculated using MP 2/6-31G **//SCF /6-31G ** calculations. The results are discussed with reference to limitations of the chosen models. © 1996 John Wiley & Sons, Inc.     

Raman-based geobarometry of ultrahigh-pressure metamorphic rocks: applications, problems, and perspectives

Raman-based geobarometry has recently become increasingly popular because it is an elegant way to obtain information on peak metamorphic conditions or the entire pressure-temperature-time (P-T-t) path of metamorphic rocks, especially those formed under ultrahigh-pressure (UHP) conditions. However, several problems need to be solved to get reliable estimates of metamorphic conditions. In this paper we present some examples of difficulties which can arise during the Raman spectroscopy study of solid inclusions from ultrahigh-pressure metamorphic rocks.     

微量元素与防病治病

介绍了微量元素在防治疾病中的作用及对健康长寿的意义，涉及人体必需微量元素，有害元素，有机锗，微量元素是健康长寿的重要手段以及微量元素与现代文明病。     

Multiplicity,instability, and SCF convergence problems in Hartree–Fock solutions

We present a study of the instability and convergence of Hartree–Fock (HF) ab initio solutions for the diatomic systems H₂, LiH, CH, C₂, and N₂. In our study, we consider real molecular orbitals (MOs) and analyze the classes of single‐determinant functions associated to Hartree–Fock–Roothaan (HFR) and Hartree–Fock–Pople–Nesbet (HFPN) equations. To determine the multiple HF solutions, we used either an SCF iterative procedure with aufbau and non‐aufbau ordering rules or the algebraic method (AM). Stability conditions were determined using TICS and ASDW stability matrices, derived from the maximum and minimum method of functions (MMF). We examined the relationship between pure SCF convergence criterion with the aufbau ordering rule, and the classification of the HF solution as an extremum point in its respective class of functions. Our results show that (i) in a pure converged SCF calculation, with the aufbau ordering rule, the solutions are not necessarily classified as a minimum of the HF functional with respect to the TICS or ASDW classes of solutions, and (ii) for all studied systems, we obtained local minimum points associated only with the aufbau rule and the solutions of lower energies. © 2000 John Wiley & Sons, Inc. Int J Quant Chem 76: 600–610, 2000     

Understanding ionic liquids at the molecular level: facts, problems, and controversies

Ionic liquids (ILs) are organic salts with melting points near room temperature (or by convention below 100 degrees C). Recently, their unique materials and solvent properties and the growing interest in a sustainable, "green" chemistry has led to an amazing increase in interest in such salts. A huge number of potential cation and anion families and their many substitution patterns allows the desired properties for specific applications to be selected. Because it is impossible to experimentally investigate even a small fraction of the potential cation-anion combinations, a molecular-based understanding of their properties is crucial. However, the unusual complexity of their intermolecular interactions renders molecular-based interpretations difficult, and gives rise to many controversies, speculations, and even myths about the properties that ILs allegedly possess. Herein the current knowledge about the molecular foundations of IL behavior is discussed.     

Some problems in PTC theory: solvation,crystalline lattice strength,and topology

It was shown thatS _N2-type reactions both in solid-liquid and liquid-liquid systems can proceed at the interface through the formation of cyclic adsorption complexes. The conditions for the formation of the latter were formulated, and the kinetic and thermodynamic parameters of reaction with solid ionophoric salts were estimated. A linear relation between the energy of the crystalline lattice of the salt and its melting point was estimated, the latter being shown to be useful as a simplified estimation of the reactivity of solid salts in reactions where the crystalline lattice is destroyed. In solid-liquid systems the benzene effect of solvents was discussed. In highly basic nitrogen-containing solvents (pyridine,etc.), a substitution reaction proceeds in the absence of a PT catalyst. The role of hydration in liquid-liquid systems was discussed.Reviews published in this issue were prepared on the basis of lectures presented at the conference Phase Transfer Catalysis. New Ideas and Methods (Moscow, March 21–25, 1994).Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2085–2093, November, 1995.