锡 foil, 100x100mm, thickness 0.125mm, as rolled, 99.99+%; CAS Number: 7440-31-5; Synonyms: 锡; find -GF05063228 MSDS, related peer-reviewed papers, technical documents, similar products & more at Sigma-Aldrich

锡 foil, 100x100mm, thickness 0.125mm, as rolled, 99.99+% | Sigma-Aldrich

foil, 100x100mm, thickness 0.125mm, as rolled, 99.99+%

锡 foil, 100x100mm, thickness 0.125mm, as rolled, 99.99+%

Mercury contamination removed with tin foil.

The toxicology of tin is almost entirely the toxicology of the organic compounds of tin, for the metal itself and its inorganic compounds appear to be nearly harmless for practical purposes. Furthermore, the neurotoxicity of organotin is essentially that of trimethyltin and triethyltin.

General toxicology of tin and its organic compounds.

Are nickel, vanadium, silicon, fluorine, and tin essential for man? A review.

This article reviews the literature related to the bioavailability of tin, inorganic tin compounds, and organotin compounds. On the one hand, the toxicity of metallic tin and inorganic tin compounds is low. In aqueous systems, the potential bioavailability of tin seems to depend on the concentration of the truly dissolved ion species. Some studies suggest that tin is an essential trace element for humans. However, organotin compounds have been proven to be of toxicological relevance. Triorganotin compounds are particularly toxic explaining their wide use as biocides (e.g., in antifouling paints or pesticides). Persistence of organotin compounds is governed by moderate to fast aerobic biotic degradation processes, slow anaerobic biotic degradation, slow abiotic degradation by photolysis, and fast, but reversible, adsorption/desorption processes. Organotin compounds are ubiquitously distributed in aquatic organisms. Bioconcentration in organisms and ecotoxicity are dependent on the bioavailable fraction. The bioavailability is highest at neutral and slightly alkaline pH and is reduced in the presence of dissolved organic carbon. The biomagnification of organotin compounds via the food chain is of minor importance compared with the bioconcentration from the water phase.

Case study: bioavailability of tin and tin compounds.

We set out to investigate potential differences and similarities between the selective forces acting upon the coding and noncoding regions of five different sets of genes defined according to functional and evolutionary criteria: 1) two reference gene sets presenting accelerated and slow rates of protein evolution (the Complement and Actin pathways); 2) a set of genes with evidence of accelerated evolution in at least one of their introns; and 3) two gene sets related to neurological function (Parkinson's and Alzheimer's diseases). To that effect, we combine human-chimpanzee divergence patterns with polymorphism data obtained from target resequencing 20 central chimpanzees, our closest relatives with largest long-term effective population size. By using the distribution of fitness effect-alpha extension of the McDonald-Kreitman test, we reproduce inferences of rates of evolution previously based only on divergence data on both coding and intronic sequences and also obtain inferences for other classes of genomic elements (untranslated regions, promoters, and conserved noncoding sequences). Our results suggest that 1) the distribution of fitness effect-alpha method successfully helps distinguishing different scenarios of accelerated divergence (adaptation or relaxed selective constraints) and 2) the adaptive history of coding and noncoding sequences within the gene sets analyzed is decoupled.

Analysis of Five Gene Sets in Chimpanzees Suggests Decoupling between the Action of Selection on Protein-Coding and on Noncoding Elements.

Experimental studies over the last decade have suggested an association between thymus immune and homeostatic function and exogenous tin. It has been hypothesized that the thymus gland synthesizes and secretes one or more tin bearing factors that enhance immune defenses against malignancy and retard the gradual loss of immune capacity with senescence. This review conciliates data from several divergent areas of research in order to explore the rationale for the above concepts.

Tin and the thymus gland: a review.

The electrostatic properties of lipid membranes are of profound importance as they are directly associated with membrane potential and, consequently, with numerous membrane-mediated biological phenomena. Here we address a number of methodological issues related to the computation of the electrostatic potential from atomic-scale molecular dynamics simulations of lipid bilayers. We discuss two slightly different forms of Poisson equation that are normally used to calculate the membrane potential: (i) a classical form when the potential and the electric field are chosen to be zero on one of the sides of a simulation box and (ii) an alternative form, when the potential is set to be the same on the opposite sides of a simulation box. Both forms differ by a position-dependent correction term, which has been shown to be proportional to the overall dipole moment of a bilayer system (for neutral systems). For symmetric bilayers we demonstrate that both approaches give essentially the same potential profiles, provided that simulations are long enough (a production run of at least 100 ns is required) and that fluctuations of the center of mass of a bilayer are properly accounted for. In contrast, for asymmetric lipid bilayers, the second approach is no longer appropriate due to a nonzero net dipole moment across a simulation box with a single asymmetric bilayer. We demonstrate that in this case the electrostatic potential can adequately be described by the classical form of Poisson equation, provided that it is employed in conjunction with tin-foil boundary conditions, which exactly balance a nonzero surface charge of a periodically replicated multibilayer system. Furthermore, we show that vacuum boundary conditions give qualitatively similar potential profiles for asymmetric lipid bilayers as compared to the conventional periodic boundaries, but accurate determination of the transmembrane potential difference is then hindered due to detachment of some water dipoles from bulk aqueous solution to vacuum.

Calculation of the electrostatic potential of lipid bilayers from molecular dynamics simulations: methodological issues.

Cryopreservation of ovarian tissue has been the only effective way of ex situ conservation of female germplasm in avian species. A novel needle-in-straw (NIS) vitrification method was developed to store tissue in straws instead of cryovials. Fragments of ovarian tissue from one-week old Japanese quail were transfixed on an acupuncture needle. They were immersed in equilibration and vitrification solutions containing dimethyl sulphoxide, ethylene glycol and sucrose. A layer of tin foil was rolled over the tissue fragments and the tin foil package was plunged into liquid nitrogen and inserted into a pre-cooled, 0.5-ml straw which was stored in liquid nitrogen. Tissue was also preserved using a needle immersed vitrification (NIV) method, in which tissue fragments transfixed on needles without tin foil and were stored in cryovials filled with liquid nitrogen. Cryopreserved tissue was warmed at room temperature (RT) or 37°C and the ratio of normal follicles to total visible follicles was determined by histological methods. In addition, cryopreserved and warmed tissue was cultured on the chorioallantoic membranes of fertilized chicken eggs for 5-6 days. The viability and vascularization of the grafts were evaluated. The tissue cryopreserved by NIS and warmed at RT showed comparable follicle morphology to fresh tissue and to that preserved by NIV and warmed at RT. No significant impairment on the viability or vascularization of the grafted tissue was observed. The NIS method allows tissue to be stored and transported safely and efficiently and can be used instead of cryovials in tissue cryobanking.

Novel needle-in-straw vitrification can effectively preserve the follicle morphology, viability, and vascularization of ovarian tissue in Japanese quail (Coturnix japonica).

The history of heroin smoking and the subsequent development and spread of 'chasing the dragon' are examined. The first heroin smoking originated in Shanghai in the 1920s and involved use of porcelain bowls and bamboo tubes, thereafter spreading across much of Eastern Asia and to the United States over the next decade. 'Chasing the dragon' was a later refinement of this form of heroin smoking, originating in or near Hong Kong in the 1950s, and refers to the ingestion of heroin by inhaling the vapours which result when the drug is heated-typically on tin-foil above a flame. Subsequent spread of 'chasing the dragon' included spread to other parts of South East Asia during the 1960s and 1970s, to some parts of Europe during the late 1970s and early 1980s, and to much of the Indian sub-continent during the 1980s. At the time of writing, 'chasing the dragon' has now been reliably reported from many parts of the world but not from others with an established heroin problem-such as the United States and Australia. The significance of this new form of heroin use is examined, including consideration of the role of the different effect with this new form of use, the different types of heroin, and changing public attitudes to injecting.

Heroin smoking by 'chasing the dragon': origins and history.

The quality of paraffin sections is determined to a considerable degree by the properties of paraffin block such as crystal size and spatial homogeneity. A new temperature regimen of treatment in preparation of paraffin blocks has been developed. After impregnation, pieces of tissue are overlayed with paraffin at a temperature of 56-60 degrees C in paper-tin foil dishes and then immediately placed in an antifreeze at 0 degree to -5 degrees C. The internal stresses, deformations, and microcracks occurring in this procedure are eliminated by incubation of the resulting block in a thermostat at 45 degrees C in vapours of low-melting fraction of paraffin (2-24 hours) followed by rapid cooling with cold air (from -5 degrees to -10 degrees C). The second step of the treatment may also be used for improvement of the quality of paraffin blocks after long-term storage.

[Modification of the method of preparation of paraffin blocks].

In a dentate subject a jaw relation can either be determined in maximum intercuspation and is as such given by the occlusal morphology, or the mandibular position can be allocated according to the centric position of the condyles. For comprehensive restorative treatment or analytic measures of the occlusion it is important to record the centric condylar position. Various registration methods have been described in the literature, but there is no consensus on which is the 'best'. The aim of the present study was therefore to assess the accuracy of various registration methods and evaluate a possible influence of the used materials. Four dentists were involved in the clinical part of the study, another was responsible for the measurements. Impressions were taken from 81 fully dentate volunteers. The casts were mounted by face-bow transfer and central-bearing-point (CBP) registration into Dentatus articulators. Subsequently the centric condylar position was determined with six different methods and materials, respectively. Each method was reproduced twice so that a total of 18 registrations was performed per patient. The mandibular positions which resulted from the individual registrations were then repeatedly compared in the condylar area using a computer supported specially modified measuring articulator. The accuracy was found best for the unrefined wax wafer registration (x=0.33 mm) and with an average of 0.44 mm worst when using acrylic wafers. The CBP and frontal jig methods as well as tin-foil and refined wax wafers showed an accuracy in-between these boundaries. The biggest measured mandibular displacement between any two registrations were considerably 2.0 mm. However, the described differences in accuracy between the various methods and materials proved statistically not significant. All investigated jaw registrations showed an accuracy of about 20 times the tactile fine sensibility of natural teeth which has to be taken into account when inserting fixed prosthetic restorations in centric condylar position. Despite meticulous clinical and technical procedures small occlusal adjustments are therefore almost unavoidable.

Accuracy of check-bite registration and centric condylar position.

Applications of tin-containing intermediates to carbohydrate chemistry.

Inorganic tin: chemistry, disposition and role in nuclear medicine diagnostic skeletal imaging agents.

Inorganic tin salts are poorly absorbed and rapidly excreted in the faeces; as a result they have a low toxicity. Only about 5 per cent is absorbed from the gastrointestinal tract, widely distributed in the body, then excreted by the kidney. Some tin is deposited in lung and bone. Some tin salts can cause renal necrosis after parenteral doses. Mutagenic studies on metallic tin and its compounds have been negative. Long-term animal carcinogenic studies have shown fewer malignant tumours in animals exposed to tin than in controls. Human volunteers developed mild signs of toxicity with tin, given in fruit juices, at a concentration of 1400 mg per litre. The WHO 1973 permissible limit for tin in tinned food is 250 micrograms per kg. The adult daily intake of tin was about 17 mg per day in 1940, but it has now decreased to about 3.5 mg, due to improvements in technique of tinning with enamel overcoat and crimped lids to minimize exposure to tin and lead solder. This level is well below the level of 5-7 mg per kg body weight shown to give rise to toxic symptoms. Tin deficiency has not been described in man. Amounts in excess of 130 mg per day have been shown to accumulate in liver and kidneys. Many of the organotin compounds are toxic; the most toxic being trimethyltin and triethyltin, which are well absorbed from the gastrointestinal tract. Most of the other alkyl and aryltin compounds are poorly absorbed from the gastrointestinal tract, and are therefore less toxic when given orally than when given parenterally. The main results of toxicity are skin and eye irritation; cholangitis of the lower biliary tract, and later hepatotoxicity; and neurotoxicity, which has been shown to be due to intramyelin oedema induced by triethyltin, and neuronal necrosis caused by trimethyltin. Many of the organotin compounds affect mitochondrial oxidative phosphorylation and alter membranes, but the contribution of these biochemical and membrane effects in the cause of intramyelin oedema and neuronal necrosis has not been fully clarified. Widespread degeneration results, especially with trimethyltin. Peripheral neuropathy has not been reported as occurring with either inorganic or organic tin in humans. Certain dialkyltin compounds have been shown to cause adverse effects on cell-mediated immunity, specifically on the T cell lymphocyte. Experimental studies have failed to reveal any evidence of carcinogenicity, mutagenicity, or teratogenicity. Recent studies suggest that tin compounds exhibit some antitumour activity and may have a future role in cancer diagnosis and chemotherapy, and in controlling hyperbilirubinaemia.

Toxicity of tin and its compounds.

To evaluate the necessity of three-dimensional imaging (computed tomography [CT]/cone-beam computed tomography [CBCT]) for paramedian insertion of palatal implants. Lateral radiographs and CBCT scans were performed from 18 human skulls. For lateral cephalometry, the nasal floor (right/left) and the oral hard palate of all skulls were lined with a tin foil for contrast enhancement. The quantity of vertical bone as measured on lateral radiographs was compared with CBCT measurements obtained in median and parasagittal planes and at minimum bone height. Spearman's rank correlation coefficients were determined for bivariate correlation analysis. The median palatal bone height on CBCT (mean 8.98 mm; standard deviation [SD] 3.4) was markedly higher than the vertical height seen on lateral radiographs (mean 6.6 mm; SD 3.2). Comparing lateral cephalometry with CBCT, the strongest association was observed at the minimum palatal bone height (r=0.926; P<0.001; Spearman's rank correlation coefficient). Lateral radiographs allow accurate and adequate assessment of vertical bone before paramedian insertion of palatal implants. The vertical bone dimension as displayed on lateral cephalometry reflects the minimum bone height rather than maximum bone in the median plane. Therefore, a preoperative CT or CBCT is only indicated when the lateral cephalometry reveals a marginal quantity of bone.

Vertical palatal bone dimensions on lateral cephalometry and cone-beam computed tomography: implications for palatal implant placement.

Previously, electrical injuries have been suggested caused only by the concomitant heat developed during the passage of an electrical current. Recent experimental studies on fully anesthetized pigs and the study of one human case have, however, shown typical electrical alterations. The purpose of the present study was further to evaluate the histology of electrically induced changes in the skin in humans. In addition, supplementary in vivo methods for evaluation of skin changes as high-frequency ultrasound and Raman spectroscopy were used. The skin of 11 patients treated with a defibrillation of the heart was examined for macroscopic changes, the skin of eight of them also for histologic changes and for changes observable via supplementary methods. Immediately and 7 days after the defibrillation, fractions of a narrow red ring were observed along the periphery of the tin-foil electrode. Epidermis showed signs previously observed following electrical influence: segmental alterations often related to the openings of sweat ducts, darkstaining or "empty" nuclei and homogeneous cytoplasm, eosinophilic or pale. Dermis did not show the specific sign of electrical influence: deposits of calcium salts on dermal fibres, neither via histologic examination nor via high-frequency ultrasonography and Raman spectroscopy. Fractions of a narrow red ring along the periphery of the electrode showing histological signs of electric influence in epidermis thus appear to be characteristic of high voltage electrical injury.

Skin changes following defibrillation. The effect of high voltage direct current.

Commonly used methods of analysis for tin in foods.

Methods for both total and form-variable tin analysis in biological media are reviewed. While total tin analysis was common in the past, and in some cases still is, better understanding of the toxicology and toxicokinetics of organotins in biological systems requires knowledge of specific tin forms present. Both chromatographic and non-chromatographic methods for chemical speciation of organotins in various media have been described, the former appearing to offer the most promising approaches. High performance liquid chromatography (HPLC) in tandem with tin-specific metal detection presently appears to offer the most promise.

The analysis of total and form-variable tin in various media.

General aspects of tin-free antifouling paints.

Tinplate is light gauge, steel sheet or strip, coated on both sides with commercially pure tin and has been used for well over a hundred years as a robust form of food packaging. Altogether, about 25,000 million food cans are produced and filled in Europe per annum, about 20% of these having plain internal (unlacquered) tin-coated steel bodies. Worldwide, the total for food packaging is approximately 80,000 million cans. Tinplate is also extensively used for the production of beverage cans. Europe produces and fills over 15,000 million tinplate beverage cans per annum all of which are internally lacquered. The use of tinplate for food and beverage packaging, will result in some tin dissolving into the food content, particularly when plain uncoated internal surfaces are used. The Provisional Tolerable Weekly Intake for tin is 14 mg/kg body weight and recommended maximum permissible levels of tin in food are typically 250 mg/kg (200 mg/kg UK) for solid foods and 150 mg/kg for beverages. However, the question arises as to whether evidence exists that such elevated levels of tin in food in any way constitute a risk to human health. This review considers the factors affecting the dissolution of tin, the reported measurements/surveys of actual levels of tin in canned foods and the studies and reports of acute (short term) toxicity relating to the ingestion of elevated levels of tin in food products. Chronic studies are mentioned, but are not covered in detail, since the review is mainly concerned with possible effects from the ingestion of single high doses. From published data, there appears to be a small amount of evidence suggesting that consumption of food or beverages containing tin at concentrations at or below 200 ppm has caused adverse gastrointestinal effects in an unknown but possibly small proportion of those exposed. However, the evidence supporting this assertion is derived from reports of adverse effects which offer data that are limited, incomplete or of uncertain veracity. Clinical studies provide greater confidence regarding the effects of exposure concentration and dose, but few relevant studies have been made. Adverse gastrointestinal effects were observed in limited clinical studies at concentrations of 700 ppm or above, although no adverse gastrointestinal effects were also reported in two studies at higher concentrations. Overall, therefore, the published data do not present a particularly comprehensive profile on the toxic hazard to man of acute exposure to divalent inorganic tin. A food survey suggested that the contents of almost 4% of plain internal tinplate food cans contain over 150 mg/kg of tin and over 2.5 million such cans are consumed every year in the UK alone. Despite this, in the last 25 years, there have been no reports of acute effects attributable to tin contamination in the range 100-200 ppm. These facts strongly suggest that there is little evidence for an association between the consumption of food containing tin at concentrations up to 200 ppm and significant acute adverse gastrointestinal effects. Clearly though, only further clinical studies will generate unequivocal evidence that current legislative limits provide safe levels for adults in the general population.

锡

foil, 100x100mm, thickness 0.125mm, as rolled, 99.99+%

属性

测定

形式

manufacturer/tradename

电阻率

尺寸 × 厚度

bp

mp

密度

SMILES string

InChI

InChI key

说明

一般描述

法律信息

文件

分析证书

原产地证书 (CofO)

更多文件

Quotes and Ordering

同行评审论文

技术服务

支持

订单

公司

社交媒体

Merck