Artificial Substances Research Articles

Effect of long‐term intake of natural and artificial sweeteners in rats

The use of sugar substitutes has been increased but its use is controversial. The aim of the present work was to study the effect of different natural and artificial sweeteners on obesity promotion and abnormalities due to lipids in the liver and heart. An experimental design using five nine‐rats groups was established using two natural and two artificial sweeteners during 73d: 1 Fructose 15%; 2 Sucrose 10%; 3 Aspartame 0.3%; 4 Sucralose 0.19%; and 5 Water as control. All animals received a standard diet ad libitum. Body weight, food and water intake were measured three times a week. Rats were sacrificed and heart and liver were removed for histological analysis. Results indicated that long‐term fructose intake in water promoted the highest weight gain in the rats, as well as the highest increase in pericardic tissue. Rats that consumed sucrose, although the ingestion of water volume was the highest, they had the lowest food consumption, and the lowest body weight gain. Animals on artificial sweeteners, showed the highest food intake and the pericardic fat areas were much higher than control groups. These experiments show a direct relationship of gain weight, alterations in food intake and alterations heart and hepatic histology of rats on natural and artificial substances.

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Graphene oxide (GO) sheets possess a 2D filiform structure and were indigenously synthesized via the enhanced Hummer methodology. It is accepted that the redox approach may be a distinctive technique to fabricate GO films as a sheet on an expanded scale. Instrumental characterizations showed that GO sheets ready during this study had a bi-directional lamellar layer structure and a thickness of 3–5 nm. FT-IR study was carried out to validate due to the incidence of oxygen functional groups in GO films. The Raman spectra of GO sheets have been simulated to get stable structure, functional groups. EDAX microanalysis, Elemental analyzer (EA), and X-ray photoelectron spectroscope (XPS) analyzed the elements of artificial substances. Moreover, the morphology of GO thin film was delineated during this experimental study.

Perturbation of spermatogenesis by androgen antagonists directly injected into seminiferous tubules of live mice

Natural and artificial substances present in the environment can affect our health. Testicular toxicants in particular are troublesome, because they disturb gonadal function of males. Translocation of substances into the seminiferous epithelium where sperm production proceeds is restricted due to the blood-testis barrier, but this permeability barrier temporarily disappears under physiological and sub-physiological conditions. This means that any substance could enter the seminiferous epithelium and disturb sperm production. To reduce the risk posed by such toxins, it is important to accurately determine which substances possess the toxicity. However, existing assay systems are not satisfactory in terms of both accuracy and sensitivity. Here, we report the establishment of such a system. We injected the androgen antagonists, flutamide and vinclozolin, directly into seminiferous tubules of live mice, which had been treated with busulfan for a temporal arrest of spermatogenesis, and the testes were histologically examined to see the effect of the injected materials on spermatogenesis that was in the process of recovery. The injection of either substance brought about a severe impairment of spermatogenesis at an amount over a million times smaller than that used in the previous assay systems where animals are administered with test substances outside of the testis. In contrast, these androgen antagonists at the same doses showed lesser effects when intratubularly or intraperitoneally administered into mice that had not been pretreated with busulfan. We propose that the method adopted in this study is a novel assay system to identify potential testicular toxicants.

Hugh Ross's Curious Lymphocyte Experiments

It is now almost 100 years since Hugh Campbell Ross began his experiments on white blood cells and cancer. By suspending peripheral blood cells in a solution of agar gel, he was able to observe changes in them provoked by various natural and artificial substances, which he named auxetics, kinetics, or augmentors, depending on the effects they produced. After his early experience he focused his attention particularly on lymphocytes in peripheral blood samples; he claimed to have observed rapid division in them, although at that time they were looked upon as end cells without a future. He contended that his results challenged what had become the orthodox view of the role of the nucleus in mitosis, asserting that cytologists had been led astray by relying on examination of fixed, dead structures. When doubt was cast on his claim to have induced cell division, his brother Ronald, Nobel laureate in physiology or medicine, came to his defense, but to no avail, and although he continued his experiments for a number of years they were quietly forgotten. Fifty years later the occurrence of mitotic division of peripheral blood lymphocytes was established beyond any doubt by Nowell and Hirschhorn.

The chemotactic characteristics of the S and R dissociants of Bacillus thuringiensis

The chemotactic responses of Bacillus thuringiensis subsp. dendrolimus (strain 49) and thuringiensis (strain 2002) and their morphological dissociants were studied by using some natural and artificial substances as effectors. The 12-h-old wild-type cells (S variants) of both strains were found to be motile and similar in their chemotactic responses, whereas the chemotactic responses of R variants were different.

Bradykinin production during donor plasmapheresis procedures

Extracorporeal circuits made of artificial substances may induce blood cells and humoral activation. Negatively charged surfaces may activate Factor XII and the prekallikrein-kinin cascade, resulting in bradykinin (BK) production. BK has been considered to be involved in severe hypotensive reactions occurring during therapeutic apheresis in patients taking angiotensin-converting enzyme (ACE) inhibitors or in those receiving platelet transfusion. In this study we investigated BK production during donor plasmapheresis procedures. Eighteen volunteer donors entered the study protocol. Nine of them were taking ACE inhibitors. Their blood pressure (BP) was monitored both pre- and post-apheresis, and BK determination was carried out using a competitive enzyme immunoassay (EIA), in plasma samples collected both during and at completion of the procedure. In addition, a limited number of thawed plasma units were checked for BK. No side-effects were observed during the procedures. However, donors taking ACE inhibitors showed a higher variation of their systolic BP compared to those who were not taking ACE inhibitors, while diastolic BP percentage variations did not differ significantly between the two groups. The BK concentration was considerably higher in donors taking ACE inhibitors: 183 +/- 26 versus 82 +/- 6 ng/ml (P < 0.0001) after the first collection cycle and 142 +/- 20 versus 65 +/- 11 ng/ml (P < 0.0001) in the final samples. BK was also detected, at a lower concentration (15 ng/ml), in one out of four thawed plasma units obtained from donors taking ACE inhibitors and at 1 ng/ml in one out of two thawed plasma units from the control group. Donors taking ACE inhibitors and undergoing plasmapheresis showed higher levels of BK compared to the control group. Furthermore, the detection of BK in plasma units after a freeze-thaw procedure might explain the sudden hypotensive reaction occurring during therapeutic plasma exchange when plasmapheresis units are adopted as substitution fluids. Further investigations are needed to assess the real clinical importance of the presence of BK in plasma units.

Performance Improvement in Schools

In this article, we suggest a parallel can be drawn between pressures to perform in sports and pressures on schools to perform. In developing this analogy we hold that schools, like athletes, have been exposed to the temptation of using artificial performance-enhancing substances. The application of such measures, although sometimes successful in the short term, has led to a number of unpleasant side effects and little enduring change in classrooms. This has given rise in some quarters to negative feelings about the future of education. On a more positive note, we extend the analogy by discussing several ‘natural’ performance-enhancing methods that are available to principals. These, we argue, offer increased hope for sustainable change in schools.

Autologous Fibroblasts for Wrinkle Treatment

Of the numerous filler materials such as human and bovine collagen, fat cells, and various artificial substances used to correct wrinkles and other skin depressions, none are ideal. In this manufacturer-sponsored pilot study, 10 subjects underwent a series of three treatments for a prominent facial wrinkle or …

Toxicity, Risk, and "Artificial Substances": Examining the Real Equations.

Toxicity, Risk, and "Artificial Substances": Examining the Real Equations.

Temporary industrial binders for molding of industrial ceramics (Review)

The basic stages of the evolution of the technology for ceramic and refractory materials are directly related to refinement of the temporary industrial binders (TIB) used. This constituent of the molding mass and semifinished product determines the properties of the finished product to a significant degree. The information on TIB formulations is primarily concentrated in the patent literature. The number of studies and reviews of the main problems in making up molding masses, the reaction of the TIB with the ceramic solid phase, and planning of the industrial binder with consideration of the requirements for the finished products is limited [1-3]. This is partially due to the lack of unambiguous criteria for evaluating the quality of the masses and selecting binders and the complexities of using the experimental apparatus for methods of physical and colloid chemistry, mechanisms of disperse systems, and the physical chemistry of polymers. This is because dilute solutions, and not the concentrated solutions typical of ceramics technology, solutions of macromolecular compounds (MMC), and highly disperse fillers are the traditional objects. Due to the necessity of molding semiproducts of complex shape with elevated requirements for surface quality, geometric dimensions, and homogeneity, the urgency of developing new binder compositions has now increased significantly. The analysis of the assortment and trends in the development of TIB formulations can also be useful to some degree in creating new technological solutions. The requirement of increasing the level of the electrophysical properties of sparkplugs for internal combustion aircraft engines has led to the exclusion of clay plastic components from the composition of steatite masses and made it necessary to add molding powder to the composition to give the solution of polyvinyl alcohol (PVA) the required technological properties. The first publications on this problem date back to the mid-1940s [4, 5]. The tendency to reduce or eliminate some of the plastic components in the formulations for ceramic and refractory masses and to use temporary binders in ceramics technology has been tracked since the end of the 1930s. In the 1940sbeginning of the 1950s, a wide range of TIB based on aqueous solutions of natural and partially artificial macromolecular substances and products were used in production: flour, starch, gelatin, cellulose derivatives, alginates, and resins [6-8]. Generalization of the studies published in this period led to the formulation of principles for classification of TIB for molding of semiproducts of the basic kinds of industrial ceramics based on the origin and chemical nature of the polymer [9, 10]. Hypotheses were advanced in the same period concerning the complex physicochemical reactions in the ceramic material-MMC solution system [8], and the role of the viscosity of the dispersion medium in molding was emphasized [11]. Two limiting cases of the reaction in the ceramic material-TIB system and formation of the molding mass were formulated in 1961 [12]: due to the high viscosity of the dispersion medium (resin, petrolatum, etc.) in the almost total absence of any reaction between disperse phase and dispersion medium; with a strong reaction between TIB and solid phase and formation of cross-linked layers on the phase boundary with properties different from the properties of the dispersion medium in bulk. For the first time, a hypothesis was thus advanced concerning the possibility of formation of a plastic molding mass due to forming of interfacial boundary structures with anomalous properties. In the same period, an analogy was drawn in [13] for the structure of plastic hydrate-gel shells in clay masses and the boundary layers in dispersions of the oxide material- MMC

Band selection procedure for multispectral scanners

Advances in high spectral resolution sensors and in data handling capabilities are enabling development of greatly improved remote-sensing devices for resource monitoring, so that design trade-offs are required. A methodology for optimizing selection of spectral bands for multispectral instruments such as those on the LANDSAT series of satellites is described. The method is applied to a collection of laboratory and outdoor spectra of natural and artificial materials. These reflectance spectra represent the visible and near-infrared spectral ranges at high (0.01-μm) spectral resolution. For most natural materials 15-25 spectral bands appear to be sufficient to describe spectral variability, whereas description of minerals and some artificial substances may require double this number of bands.

Interaction of pesticides with the soluble fraction of natural and artificial humic substances

Abstract The adsorption of two cationic pesticides on the soluble part of natural and artificial humic substances, and their mechanisms of interaction, have been studied using the equilibrium dialysis method. Paraquat and chlordimeform in diverse concentrations have been used. A natural fulvic acid extracted from a spodosol soil, a commercial humic acid and polymaleic acid vere used as comparison. Chlordimeform adsorption data from this work are higher than those obtained in a previous paper without dissolving the humic substances. Paraquat isotherms always present values lower than chlordimeform ones. Natural fulvic acid adsorbs more than the commercial humic substance for both pesticides. The results show that acidified soluble fraction of the commercial HA is more similar to natural FA than polymaleic acid. However the latter is generally used as a model for fulvic acid. The interaction mechanisms between these humic substances and cationic pesticides were principally cation‐exchange processes, but H‐b...

Cryoprotection of Plagiomnium affine induced by various natural and artificial substances

Greenhouse-grown shoots of Plagiomnium affine (Funck) Kop. were incubated in solutions of various potential cryoprotectants prior to freeze–thaw treatment. Sucrose uptake and release and plasmolysis studies indicated that the permeability of the plasma membrane of leaf cells for sugars, proline, and polyethylene glycols with average molecular weights of 400 (PEG-400) and 1000 (PEG-1000) was very low or insignificant, but that dimethylsulfoxide readily penetrated into the cytosol. Pretreatment of shoots at concentrations of these compounds that induced plasmolysis effectively increased the cryoprotection of the moss tissue. Obviously, damage of the plasma membrane by freeze–thaw treatment was avoided when compatible solutes reached a sufficient concentration either in the cytosol, outside the protoplast, or in both compartments. Pretreatment of shoots with hypertonic glycerol and PEG-4000 solutions also caused plasmolysis but did not prevent freeze–thaw damage. Efficient cryoprotection of moss thalli by various additives indicates that cryoprotective compounds could also play a role in acquisition of frost tolerance of bryophytes. Key words: cryoprotection, freezing, frost tolerance, permeation, photosynthesis, Plagiomnium affine, sucrose.

Fixing the Boundaries of Physical Gender: Side Effects of Anti-Drug Campaigns in Athletics

Over 40 anti-drug campaign media texts, including posters, videotapes, and brochures, served as data for this study. These texts were systematically analyzed and many prevalent themes were identified and categorized. Several themes are highlighted, focusing on assumptions and interpretations that the texts encourage readers to make. The purpose of this study is to illustrate how many of the anti-drug media campaigns, particularly those concerned with steroids, are problematic because they encourage readers to assume that bodies naturally fit into unambiguous bipolar categories of gender, and that steroids are artificial substances that disrupt this natural gender dichotomization. The assumptions that bodies are purely natural and drugs are artificial substances that disrupt natural bodies are also discussed because they are interconnected with and help to legitimate the assumption of physical gender dichotomization. These media texts are examined in the light of gender relations, wherein the embodiment of particular forms of gender is seen as crucial to the maintenance of the present gender order.

Milestones in modern plastic surgery. Deformity of nasal dorsum through loss of substance: correction by bone grafting. By Roberto Farina. 1951.

The author presents fifty-seven cases of nasal deformities. This work is concerned with deformities of the nasal dorsum. In three cases the repair was carried out by the Straith 's technique. In another three cases artificial substances were employed. The author also stated that he no longer uses acrylics, based on biological knowledge. On 51 patients the repair was performed with osteoperiosteal graft taken from the crest of the tibia. The grafts were always autogenous. It seems that the technique employed by the author is original. The percentage of bad results is 9.8% and is connected with those cases suffering from Hansen's disease.

Determination of o-Toluenesulfonamide in Artificial Sweeteners Containing Saccharin

A gas-liquid chromatographic (GLC) procedure with p-toluenesulfonamide (p-TS) as an internal standard is used to determine o-toluenesulfonamide (o-TS), a major impurity in artificial sweetening substances containing saccharin. Although p-TS can itself occur as an impurity in samples, it is usually absent or present in very small amounts; the highest quantity found in 13 samples analyzed was about 1 ppm. The presence of appreciable amounts, however, would not pose a problem with the GLC procedure. Recoveries of standard o-TS added at various levels were approximately 90%.

Polymers in medicine.

AbstractThe problems encountered in the use of artificial materials in the body are discussed, using as example the artificial heart. In the quest for suitable materials, numerous investigations have been carried out, including, inter alia, studies on the adsorption of proteins on polymer surfaces and on the passivation of such surfaces by coating with proteins or by the growth of cell cultures. The development of passive artificial substances is also discussed.

Oral implantology and oral carcinogenesis in primates.

AbstractThe projection of basic clinical research into practical application for the patient's benefit is one of the prime goals of biomedical research. The non‐human primate, by its close proximity to man, affords an ideal experimental model to meet the needs of such scientific research.Our dentally orientated investigations have encompassed the fields of oral implantology and oral carcinogenesis. The former has delved into reimplantation of natural teeth and implantation of a variety of artificial substances such as: plastics, ceramics, and pyrolite carbons, which have been utilized for bone and/or tooth replacement in a variety of forms.The chemical carcinogenesis research effort has been directed toward identifying the carcinogenic substance in betel quid chewing, which is thought to be a major cause of the high incidence of oral cancer in India.

ABS as a Geological Tracer

IT is well known that artificial radioactive substances originating from nuclear explosions may be used as tracers in studies of atmospheric circulation1 and ocean currents2. Other artificial environmental contaminants may be of use in this way. I have found that alkylbenzenesulphonates (ABS), widely-used components of domestic and industrial synthetic detergent, could be used as such a tracer for the geological study to estimate the rate of sedimentation in the coastal area of the sea.

Homograft skin for wound coverage. A study of versatility.

Closure of the open burn wound is the most important factor in the recovery of the thermally injured patient. In lieu of autograft skin, materials have been sought that would effectively cover large open wounds. Such a substance would of necessity provide the following: (1) control of bacterial growth, (2) a means to prepare and preserve the wounds for definitive closure, and (3) effective vapor and exudate barrier. Many artificial substances have been tried, and some have been successful in accomplishing adherence by means of tissue ingrowth. Unfortunately, one cannot equate adherence with protection, and invasive infection usually supervenes. Homograft skin, however, satisfies all the requirements in a uniquely effective manner. In 1881, Girdner reported the removal of skin from a suicide victim for use on the wounds of a patient struck by lightning. 1 That same year, Schede utilized skin from fresh amputation specimens as well as from cadavers.