The effect of haemolysis on certain canine serum chemistry parameters

Haemolysis has been known to cause artefacts in certain canine serum chemistry parameters. These parameters are often used by researchers to detect toxicity in certain studies; haemolysis, therefore, can make serum chemistry interpretation very difficult. In order to determine whether a relationship existed between the level of haemolysis and certain canine serum chemistry parameters, haemolysis was artificially induced by adding a haemolysate of known haemoglobin concentration to serum specimens. A routine clinical chemistry profile was performed on each specimen. Statistical analyses were performed on the results to examine the relationship between level of haemolysis and serum chemistry results. Interpretation of serum chemistry results of haemolysed canine sera paralleled, in most cases, human historical data.     

量子化学在生物分子领域的研究进展

量子化学的方法对生物分子研究的发展提供了全新的思路和方法。本文介绍了量子化学的基本计算方法,并综述了近两年来量子化学方法在生物分子领域的研究进展。     

Bad chemistry

General chemistry courses haven't changed significantly in forty years. Because most basic chemistry students are premedical students, medical schools have enormous influence and could help us start all over again to create undergraduate chemistry education that works.     

污染生态化学:现状与展望

随着生态学和环境化学的发展和交叉,形成了一门新的学科－污染生态化学。目前,它的主要研究内容包括化学污染物的迁移转化及其微观生态化学过程、化学污染的生态效应与毒理及生态风险评价、全球变化的生态化学、生态系统中化学污染物的分析与监测和污染控制生态化学等５个方面。在知识创新的科学目标指导下,污染生态化学今后的工作必须加强从理论上进行突破,在对基础研究进行深入的同时,应该特别注意开展一些应用研究,从而实现     

Automated synthesis and combinatorial chemistry

The advent of combinatorial chemistry for the high-throughput synthesis of compounds has driven the advancement of new and emerging technologies for synthetic chemistry laboratories. Automated methods for reaction design, information management, chemical synthesis, compound analysis, and biological testing are necessary to realize the full potential of combinatorial chemistry efforts.     

Influence of microwave irradiation on enzymatic properties: applications in enzyme chemistry

Although microwave-assisted reactions are widely applied in various domains of organic chemistry, their use in the area of enzyme chemistry has been rather limited, due to the high temperatures associated with the microwave heating: Because current technology, allows a good control of reaction parameters, several examples of microwave-assisted enzyme chemistry have been reported, using stable and effective biocatalysts (modified enzymes). The purpose of this review is to highlight the applications and studies on the influence of microwave irradiation on enzymatic properties and their application in enzyme chemistry.     

Effects of agricultural land use on water chemistry of mire pools in the Ishikari Peatland, northern Japan

Concomitant with farmland development in the Ishikari Peatland of northern Japan, deterioration of water chemistry has become increasingly evident at mire pools there. Using spatial analysis methods with a geographic information system and a statistical methodology, this study examined the effects of agricultural land use on the pool water chemistry. A water chemistry survey of several pools showed that nitrogen, phosphorus, and suspended-solid concentrations were remarkably higher than those in pools that had been undisturbed or less-disturbed by land-use development. Principal component analysis (PCA) was conducted to summarize water chemistry variables. Correlation analysis was conducted between the principal component (PC) scores and land-use variables to clarify land-use effects. Results of the PCA showed that the water chemistry variances were accounted for by the first two PCs: PC1 included farmland subsurface drainage containing nitrogen, specifically nitrate, and mineral ions; PC2 included farmland surface drainage containing soil particles and ammonium nitrogen. These PC scores were also affected by the number of inflow ditches and the total area of farmland located within the drainage catchment of inflow ditches leading to the pools. Results suggest that farmland subsurface and surface drainage water flowing into the pools degraded the water chemistry. The extent of the effects of drainage water depended on agricultural practices such as fertilizer application and paddy-field puddling (i.e., mechanical homogenization of water-saturated soil). Accordingly, water chemistry of the study pools was affected by agricultural practices and by the amount of farmland in the drainage basin, engendering eutrophication, and the deterioration of water chemistry. Therefore, preservation of water chemistry necessitates changes in agricultural practices, such as improving fertilizer application methods, along with measures related to land-use planning such as changing the drainage ditches’ flow direction.     

Influence of microwave irradiation on enzymatic properties: applications in enzyme chemistry

Although microwave-assisted reactions are widely applied in various domains of organic chemistry, their use in the area of enzyme chemistry has been rather limited, due to the high temperatures associated with the microwave heating: Because current technology, allows a good control of reaction parameters, several examples of microwave-assisted enzyme chemistry have been reported, using stable and effective biocatalysts (modified enzymes). The purpose of this review is to highlight the applications and studies on the influence of microwave irradiation on enzymatic properties and their application in enzyme chemistry.     

Harnessing biocompatible chemistry for developing improved and novel microbial cell factories

White biotechnology relies on the sophisticated chemical machinery inside living cells for producing a broad range of useful compounds in a sustainable and environmentally friendly way. However, despite the impressive repertoire of compounds that can be generated using white biotechnology, this approach cannot currently fully replace traditional chemical production, often relying on petroleum as a raw material. One challenge is the limited number of chemical transformations taking place in living organisms. Biocompatible chemistry, that is non-enzymatic chemical reactions taking place under mild conditions compatible with living organisms, could provide a solution. Biocompatible chemistry is not a novel invention, and has since long been used by living organisms. Examples include Fenton chemistry, used by microorganisms for degrading plant materials, and manganese or ketoacids dependent chemistry used for detoxifying reactive oxygen species. However, harnessing biocompatible chemistry for expanding the chemical repertoire of living cells is a relatively novel approach within white biotechnology, and it could potentially be used for producing valuable compounds which living organisms otherwise are not able to generate. In this mini review, we discuss such applications of biocompatible chemistry, and clarify the potential that lies in using biocompatible chemistry in conjunction with metabolically engineered cell factories for cheap substrate utilization, improved cell physiology, efficient pathway construction and novel chemicals production.     

The way from medical to physiological chemistry at the University of G?ttingen, 1840-1940

In the nineteenth century chemistry was separated from medicine and reorganized as a "pure" academic science. Those left-over parts of chemistry that were more oriented towards medical application formed the nucleus of modern physiological chemistry, but could usually only exist in connection with other subjects. Especially the combination with physiology proved to be stable. Discipline building was delayed by the fact that a lot of physiologists resented a separation from physiology. Also in G?ttingen physiological chemistry was attributed to the Physiological Institute, but initially still had close connections with the General chemical Laboratory. At the end of the nineteenth century a first attempt to establish itself as a discipline together with hygiene failed. Physiological chemistry stayed a part of physiology until 1939 when the Institute of Physiological Chemistry was finally founded. The G?ttingen way is characteristic for the general establishment of the discipline in Germany.     

Microfluidic combinatorial chemistry

Microreactors are finding increasing application in the field of combinatorial chemistry. In the past few years, microreactor chemistry has shown great promise as a novel method on which to build new chemical technology and processes. It has been conclusively demonstrated that reactions performed within microreactors invariably generate relatively pure products in high yield. One of the immediate and obvious applications is therefore in combinatorial chemistry and drug discovery.     

Testing the potential for conflicting selection on floral chemical traits by pollinators and herbivores: predictions and case study

1.  There are myriad ways in which pollinators and herbivores can interact via the evolutionary and behavioural responses of their host plants.
2.  Given that both herbivores and pollinators consume and are dependent upon plant-derived nutrients and secondary metabolites, and utilize plant signals, plant chemistry should be one of the major factors mediating these interactions.
3.  Here we build upon a conceptual framework for understanding plant-mediated interactions of pollinators and herbivores. We focus on plant chemistry, in particular plant volatiles and aim to unify hypotheses for plant defence and pollination. We make predictions for the evolutionary outcomes of these interactions by hypothesizing that conflicting selection pressures from herbivores and pollinators arise from the constraints imposed by plant chemistry.
4.  We further hypothesize that plants could avoid conflicts between pollinator attraction and herbivore defence through tissue-specific regulation of pollinator reward chemistry, as well as herbivore-induced changes in flower chemistry and morphology.
5.  Finally, we test aspects of our predictions in a case study using a wild tomato species, Solanum peruvianum , to illustrate the diversity of tissue-specific and herbivore-induced differences in plant chemistry that could influence herbivore and pollinator behaviour, and plant fitness.     

Broad-scale spatial patterns of canopy cover and pond morphology affect the structure of a Neotropical amphibian metacommunity

Spatial and environmental processes influence species composition at distinct scales. Previous studies suggested that the distribution of larval anurans at the landscape-scale is influenced by environmental gradients related to adult breeding site selection, such as pond canopy cover, but not by water chemistry. However, the combined effects of spatial, pond morphology, and water chemistry variables on metacommunity structure of larval anurans have not been analyzed yet. We used a partial redundancy analysis with variation partitioning to analyze the relative influence of pond morphology (e.g., depth, area, and aquatic vegetation), water chemistry, and spatial variables on a tadpole metacommunity from southeastern Brazil. We predict that pond morphology and canopy cover will influence the metacommunity at broad spatial scales, while water chemistry would play a larger role at finer scales. We found that broad-scale spatial patterns of pond canopy cover and pond morphology strongly influenced metacommunity structure, with water chemistry being not significant. Additionally, species composition was spatially autocorrelated at short distances. We suggest that the reproductive behavior of adult anurans is driving tadpole metacommunity dynamics, since pond morphology, but not water chemistry affects breeding site selection by adults. Our results contribute to the understanding of amphibian species diversity in tropical wetlands.     

The molecular path to inorganic materials - Zinc oxide and beyond

In the current article, we present a concept for the synthesis of complex nanoscaled materials. The synthetic strategy involves a stepwise assembly of materials starting from special molecular precursors possessing multiple information. Therefore, the article focuses on a strong pervasion of inorganic materials chemistry, solid-state chemistry and molecular chemistry. The concept introduced is finally highlighted by examples from our current research in the field of zinc oxide materials.     

Solid-phase synthesis: a paradigm shift.

A personal review by the first graduate student of Professor R. Bruce Merrifield of the evolution of solid-phase synthesis and its acceptance by various subsets of the chemistry community. Solid-phase synthesis, as currently practised in the synthesis of biopolymers, combinatorial solid-phase organic chemistry, synthesis of natural products, catalyst selection, chemical ligation and materials development, has proven a paradigm shift for the chemistry community.     

Using the protein folding literature to teach biophysical chemistry to undergraduates

An understanding of physical chemistry principles enhances student understanding of biochemical phenomena; however, the application of these principles to biological examples is frequently missing in the standard undergraduate physical chemistry curriculum. The topics of protein folding and stability are based in thermodynamics and can serve as a vehicle for presenting essential thermodynamics in a context that is highly relevant to undergraduate biochemistry majors. The outline of a course that replaces the standard thermodynamics offering in physical chemistry is described. The protein folding literature is used to illustrate thermodynamic concepts in this course and students are expected to read and comprehend the assigned literature. The course is offered as a separate biophysical chemistry course for B.S. Biochemistry majors; however, elements of this course may be useful in crafting a more standard thermodynamics course for B.S. Chemistry majors in chemistry departments seeking to fulfill ACS guidelines for approved B.S. Chemistry majors.     

Soft metal thiol chemistry is not involved in the transport of arsenite by the Ars pump.

The single cysteine in the ArsB protein subunit of the arsenite resistance pump was changed to serine and alanine residues. Resistance in cells expressing the two mutant arsB genes was the same as in the wild type, and the serine substitution had no effect on the arsenite transport properties. These results eliminate possible thiol chemistry in translocation. Thus, the pump uses soft metal chemistry for metalloactivation and nonmetal chemistry for oxyanion transport.     

Multi-Scale Temporal Patterns in Stream Biogeochemistry Indicate Linked Permafrost and Ecological Dynamics of Boreal Catchments

Ecosystems - Temporal patterns in stream chemistry provide integrated signals describing the hydrological and ecological state of whole catchments. However, stream chemistry integrates multi-scale...     

Rejuvenating old fluorophores with new chemistry

The field of organic chemistry began with 19th century scientists identifying and then expanding upon synthetic dye molecules for textiles. In the 20th century, dye chemistry continued with the aim of developing photographic sensitizers and laser dyes. Now, in the 21st century, the rapid evolution of biological imaging techniques provides a new driving force for dye chemistry. Of the extant collection of synthetic fluorescent dyes for biological imaging, two classes reign supreme: rhodamines and cyanines. Here, we provide an overview of recent examples where modern chemistry is used to build these old-but-venerable classes of optically responsive molecules. These new synthetic methods access new fluorophores, which then enable sophisticated imaging experiments leading to new biological insights.     

Chemistry of the Critoniinae

The known chemistry of subtribe Critoniinae, tribe Eupatorieae, Asteraceae, is reviewed and compared with the chemistry of other subtribes of this neotropical assembly of composites.