Tau as a Biomarker of Neurodegeneration

Less than 50 years since tau was first isolated from a porcine brain, its detection in femtolitre concentrations in biological fluids is revolutionizing the diagnosis of neurodegenerative diseases. This review highlights the molecular and technological advances that have catapulted tau from obscurity to the forefront of biomarker diagnostics. Comprehensive updates are provided describing the burgeoning clinical applications of tau as a biomarker of neurodegeneration. For the clinician, tau not only enhances diagnostic accuracy, but holds promise as a predictor of clinical progression, phenotype, and response to drug therapy. For patients living with neurodegenerative disorders, characterization of tau dysregulation could provide much-needed clarity to a notoriously murky diagnostic landscape.     

Sublimation as a function of diffusion

Purification of large organic molecules in a tubular sublimator occurs by a combination of laminar flow, Knudsen diffusion, and volume diffusion. For laminar flow, the amount purified per area per driving force varies with pd², where p is pressure and d is tube diameter. For Knudsen diffusion, it varies with d and is not a function of pressure. For volume diffusion, it is constant, consistent with experiment. This volume diffusion mechanism may offer an alternative explanation to slip flow for dilute gas transport of both organic semiconductors and common low molecular weight gases. © 2015 American Institute of Chemical Engineers AIChE J, 62: 861–867, 2016     

Lipoxygenase as a versatile biocatalyst

This review of lipoxygenase and lipoxygenase pathway enzymes focuses on the potential for the efficient production of useful compounds. Although the existence of lipoxygenase has been inown for many years, only recently has there been progress toward understanding the conditions required to improve yields and immobilize its activity. Maintaining a high O₂ tension is necessary to obtain good yeilds of hydroperoxides; whereas, partial anaerobic conditions can lead to hydroperoxide decomposition. Fatty hydroperoxides, obtained from lipoxygenase action, can serve as precursors for further transformation by either enzymes or chemical reactions. Well over one-hundred products from lipoxygenase-generated hydroperoxides of linoleic acid alone have been described. Examples will be given of the formation of fatty acids with epoxide, hydroxy, ketone, cyclic, and multiple functional groups. The cleavage of fatty hydroperoxides into short-chain aldehydes and alcohols also will be described. Many of the products have biological activity, suggesting a significant physiological function for lipoxygenase.     

维生素与护肤化妆品（英）

维生素对于生命的重性是众所周知的,研究中发现维生素对于保护皮肤,促进皮肤的新陈代谢有特别功效,介绍了维生素用于护理皮肤的最新研究成果,阐述了各种维生素的护肤活性和含维生素护肤化妆品的配方技术与基本结构。     

Solubilization as a Separation Process

Abstract

In this paper a separation process for hydrocarbon molecules is suggested, based on solubilization in aqueous solutions by surfactant micelles. A molecular thermodynamic approach to solubilization is formulated which relates the extent of solubilization and the selectivity to the structure and properties of the surfactant and of the solubilizate molecules. An evaluation of the solubilization characteristics of benzene and hexane in aqueous solutions of non-ionic octyl glucoside, anionic sodium dodecyl sulfate and cationic cetyl pyridinium chloride is made and solubilization phase diagrams for the above systems are constructed. These diagrams indicate the formation of micelles at concentrations which are lower than the critical micelle concentration of the surfactant alone. The calculations predict, for all three surfactants, preferential solubilization of (aromatic) benzene compared to (aliphatic) n-alkanes. The preferential solubilization of benzene is caused by its smaller molecular volume and lower interfacial tension against water. Preliminary experimental results using cetyl pyridinium chloride as surfactant and an equimolar binary mixture of hexane and benzene as solubilizates indicate a selectivity of over 7 for benzene compared to hexane, and a ratio of about one molecule of benzene solubilized for every surfactant molecule in the micelle.     

Thraustochytrid as a potential source of carotenoids

Thraustochytrids, marine protists whose dominant genera are Thraustochytrium and Schizochytrium, belong to the kingdom Chromista and are known as an industrial source of DHA. We describe here that thraustochytrid strain KH105, isolated as a DHA producer, also accumulates significant levels of β-carotene and xanthophylls including canthaxanthin and astaxanthin. A4-d cultivation using a medium composed of 10% glucose and less than 0.3% of nitrogen sources in a half-concentration of seawater gave an astaxanthin production up to 6.1 mg/L, and canthaxanthin content reached more than 10 mg/L under conditions where a higher concentration of nitrogen sources (6%) was employed. It might be advantageous in mass production systems for these carotenoids to be extracted readily by simply suspending the cells with organic solvents such as acetone and chloroform. Analyses on the morphological and life history features of the KH105 strain revealed that it belongs to the genus Schizochytrium. This particular species of thraustochytrids is thus considered to be a promising source of xanthophylls as well as DHA for use in the food industry.     

Cancer as a Metabolic Disorder

Cancer has long been considered a genetic disease characterized by a myriad of mutations that drive cancer progression. Recent accumulating evidence indicates that the dysregulated metabolism in cancer cells is more than a hallmark of cancer but may be the underlying cause of the tumor. Most of the well-characterized oncogenes or tumor suppressor genes function to sustain the altered metabolic state in cancer. Here, we review evidence supporting the altered metabolic state in cancer including key alterations in glucose, glutamine, and fatty acid metabolism. Unlike genetic alterations that do not occur in all cancer types, metabolic alterations are more common among cancer subtypes and across cancers. Recognizing cancer as a metabolic disorder could unravel key diagnostic and treatments markers that can impact approaches used in cancer management.     

Movement as a Positive Modulator of Aging

The aging of human populations, including those in Europe, is an indisputable fact. The challenge for the future is not simply prolonging human life at any cost or by any means but rather extending self-sufficiency and quality of life. Even in the most advanced societies, the eternal questions remain. Who will take care of the older generations? Will adult children’s own circumstances be sufficient to support family members as they age? For a range of complex reasons, including socioeconomic conditions, adult children are often unable or unwilling to assume responsibility for the care of older family members. For this reason, it is imperative that aging adults maintain their independence and self-care for as long as possible. Movement is an important part of self-sufficiency. Moreover, movement has been shown to improve patients’ clinical status. At a time when the coronavirus pandemic is disrupting the world, older people are among the most vulnerable. Our paper explores current knowledge and offers insights into the significant benefits of movement for the elderly, including improved immunity. We discuss the biochemical processes of aging and the counteractive effects of exercise and endogenous substances, such as vitamin D.     

Studies of a CuY zeolite as a redox catalyst

The stability and behavior of CuY in the redox cycles with $\text{CO}\text{O}{}_2$, $\text{H}{}_2\text{O}{}_2$, and $\text{CO}\text{NO}$ have been studied using a microbalance operating in the flow mode and with a standard (BET) volumetric system. When CO was used as a reducing agent CO₂ was produced, thus removing oxygen from the zeolite lattice, but when H₂ was used only some of the H₂ consumed was evolved as H₂O. The rest was retained as lattice OH groups, but this was minimal when H₂ was used after treating the sample with CO. Oxidation with NO produced only N₂. At 500 °C the sample was stable and could be reversibly oxidized and reduced through many cycles using either $\text{CO}\text{O}{}_2$ or $\text{NO}\text{CO}$. In all cases the ratio $\text{O}\text{Cu}$ was close to 0.5, i.e., $\text{1e}\text{Cu}$. Treatment in CO at higher temperatures did not affect the reversible nature of the oxidation, but now the valence change was substantially larger; it approached $\text{2e}\text{Cu}$. The crystallinity of the exchanged zeolite was studied using X-ray diffraction and by measurement of the pore filling with liquid N₂. No significant changes could be detected after the different treatments, even those performed at 750 °C. Temperature-programmed reduction, temperature-programmed oxidation, and X-ray diffraction studies were made and the different maxima are reported. CuO and Cu ^o appeared in the oxidized and reduced samples, respectively, after treatment at 750 °C in CO but not at lower temperatures. Subsequent redox cycles at 500 °C did not appear to affect the size or amount of Cu ^o crystallites. CuY was active in the oxidation of CO with O₂ or NO. Its activity was lower than that of FeY zeolite when it exhibited an oxygen-carrying capacity of 0.5 $\text{O}\text{Cu}$. Treatment with CO at 750 °C, however, reversed the situation. Kinetic results showed that the fresh CuY catalyst was close to zero order in CO and fractional order in O₂ with an activation energy of 15 kcal/mole. After treatment at 750 °C in CO, the rate law became dependent upon the $\text{CO}\text{O}{}_2$ ratio. It was close to first order in CO and zero order in O₂ under oxidizing conditions ($\text{CO}\text{O}{}_2\text{≤ 2}$), but the orders were reversed under reducing conditions ($\text{CO}\text{O}{}_2\text{> 2}$). The activation energies were 12 and 15 kcal/mole, respectively. The data suggested that the Cu²⁺ with bound oxygen are the species active in the oxidation reaction.     

Identification of Pyrroloformamide as a Cytokinesis Modulator

Discovered in the late 1940s, the pyrrolinonodithioles represent a family of potent disulfide‐containing natural products. Although they are understood in a synthetic and biosynthetic context, the biological role of these materials remains unresolved. To date, their activity has been suggested to arise through regulating RNA metabolism, and more recently they have been suggested to function as backup thiols for detoxification. Using materials identified through a natural products program, we now identify the biological function of one member of this family, pyrroloformamide, as an antimitotic agent acting, in part, by disrupting cytokinesis.     

Backup Materials as a Source of Efflorescence

Because white stains on the face of brick masonry walls are often the same salts that are associated with Portland cement, an investigation was made to determine whether efflorescing salts can originate in concrete backup block. The soluble-salts content was determined for selected clap brick, concrete block, and clay tile; wick tests were run on the material. Composite walls were built of nonefflorescing brick backed with clay tile or with concrete block; high humidity was maintained on the back side of the walls and the moisture was allowed to migrate to the dry brick face. The discoloration of the face brick was compared and the salts were identified.     

日化香料月桂腈的合成

以氨基磺酸为脱水剂，于２４０～２６０℃加热摩尔比为２∶１的尿素与月桂酸混合物１ｈ，得收率为８０．６％的月桂腈。     

Enameling as a nonsteady-state process

It is shown that linear shrinkage curves can be helpful in gaining insight into how an enemel coating is formed as the powdered bond coat is fritted. In particular, they can be of assistance in assessing the degree of oxidation for the substrate surface. The results reported here can be used both when existing enameling processes are to be improved and new ones designed. Translated from Steklo i Keramika, No. 5, pp. 27–29, May, 1997.     

Legumes as a source of natural antioxidants

The following article summarizes the most up‐to‐date information available concerning endogenous bioactives and the antioxidant activity/radical‐scavenging capacity of selected leguminous seeds, and extracts derived therefrom, as well as the impact of processing and seed germination on these bioactives. Biologically‐active compounds of interest found in leguminous seeds come from many chemical classes and include phenolic acids as well as their derivatives, flavanols, flavan‐3‐ols, anthocyanins/anthocyanidins, condensed tannins/proanthocyanidins, tocopherols, and vitamin C. Research findings from over 100 references, many of which published only within the last 10 years, have been compiled and used in this review.     

Carbon as a support for catalysts—III glassy carbon as a support for iron

As described in the Hucke patent, glassy carbons containing not only open pores of molecular size but also pores in the transitional or macropore range can be produced from appropriate formulations. The formulation always consists of a carbon-yielding monomer, an organic to yield larger pores upon its removal once the monomer has been partially polymerized, and a polymerization catalyst. It may contain a dispersing agent, depending upon the size of the larger pores which is desired. In this study, furfuryl alcohol was the monomer. Great flexibility is shown to exist in the total surface areas of the carbons which can be produced, degree of carbon molecular sieving in the super micropores, and pore volume and pore size in the larger pores following polymerization and carbonization steps. Different ways of adding iron into the mix are explored which also can have pronounced effects on the nature of the porosity in the final carbons. Further modification is shown upon addition of potassium or boron into the mix. Carbons produced are expected to have potential as catalyst supports.     

Cotton-root bark as a source of gossypol

Summary Cotton-root bark from upland short staple cotton contains up to 1.8 per cent gossypol (air-dried basis). Analyses of other parts (stalk, bark-free root, leaves, squares, immature bolls) of the cotton plant showed little or no gossypol in these structures. The gossypol content of the root bark increases with maturity of the plant, and is highest in roots gathered in the winter after the stalk has dried. Owing to the absence of oil in the root bark, the gossypol obtained therefrom by ether extraction is more easily purified than that from cottonseed. The experimental recovery of pure gossypol from one sample of root bark was 0.88 per cent. It is estimated that one acre of cotton will yield 150 kilograms of dry root bark, from which about 1.4 kilograms of pure gossypol can be recovered.     

Validation of l-Tellurienylalanine as a Phenylalanine Isostere

Mass cytometry (MC) and imaging mass cytometry (IMC^TM) have emerged as important tools for the study of biological heterogeneity. We recently demonstrated the use of l -2-tellurienylalanine (TePhe), a mimic of phenylalanine (Phe), as an MC- and IMC-compatible protein synthesis reporter. In this work, the biochemical similarity of TePhe and its cognate analogue, Phe, are examined in the context of the RNase S complex. Isothermal titration calorimetry studies show that incorporation of TePhe preserves the interaction of S-peptide with S-protein, and the dissociation constants for the interaction of the Phe and TePhe peptides are within a factor of two. The resulting RNase S complex is catalytically active without significant alterations in the enzyme's kinetic parameters. Furthermore, circular dichroism spectroscopy does not reveal any changes to the secondary structure of TePhe-substituted RNase S. These findings provide strong evidence that TePhe functions as a Phe isostere in the context of a folded protein. It is anticipated that incorporation of TePhe into peptides or peptidomimetic scaffolds will enable facile generation of MC and IMC^TM probes.     

吡氟氯禾灵类除草剂的介绍

介绍了吡氟氯禾灵类除草剂的物化性质、毒性、制备方法及应用等。     

Coenzyme A Restriction as a Factor Underlying Pre-Eclampsia with Polycystic Ovary Syndrome as a Risk Factor

Pre-eclampsia is the most common pregnancy complication affecting 1 in 20 pregnancies, characterized by high blood pressure and signs of organ damage, most often to the liver and kidneys. Metabolic network analysis of published lipidomic data points to a shortage of Coenzyme A (CoA). Gene expression profile data reveal alterations to many areas of metabolism and, crucially, to conflicting cellular regulatory mechanisms arising from the overproduction of signalling lipids driven by CoA limitation. Adverse feedback loops appear, forming sphingosine-1-phosphate (a cause of hypertension, hypoxia and inflammation), cytotoxic isoketovaleric acid (inducing acidosis and organ damage) and a thrombogenic lysophosphatidyl serine. These also induce mitochondrial and oxidative stress, leading to untimely apoptosis, which is possibly the cause of CoA restriction. This work provides a molecular basis for the signs of pre-eclampsia, why polycystic ovary syndrome is a risk factor and what might be done to treat and reduce the risk of disease.