原子荧光光谱法测定土壤中的铅、铬、镉、汞、砷、锌、铜、镍等元素研究

土壤无机污染物铅、铬、镉、汞、砷、锌、铜、镍这八大重金属,是一般土壤检测中的必检项目。金属元素在土壤中积累富集后,有可能通过雨水迁移,造成地下水,地表水污染,或者通过农作物进入食物链,进而影响食品安全和人体健康,因此,对这些元素的检测显得尤为重要。本文采用原子荧光光谱法对土壤中的金属元素进行测量,同时结合微波消解技术对样品进行处理,确保测量数据的准确性。     

Susceptibilities of non-Pseudomonas aeruginosa gram-negative nonfermentative rods to ciprofloxacin, ofloxacin, levofloxacin, D-ofloxacin, sparfloxacin, ceftazidime, piperacillin, piperacillin-tazobactam, trimethoprim-sulfamethoxazole, and imipenem

Agar dilution MICs of 10 agents against 410 non-Pseudomonas aeruginosa gram-negative nonfermentative rods were determined. MICs at which 50 and 90% of the isolates were inhibited, respectively, were as follows (in micrograms per milliliter): sparfloxacin, 0.5 and 8.0; levofloxacin, 1.0 and 8.0; ciprofloxacin, 2.0 and 32.0; ofloxacin, 2.0 and 32.0; D-ofloxacin, 32.0 and > 64.0; ceftazidime, 8.0 and 64.0; piperacillin with or without tazobactam, 16.0 and > 64.0; trimethoprim-sulfamethoxazole, 0.5 and > 64.0; imipenem, 2.0 and > 64.0. With the exception of those for Stenotrophomonas maltophilia, Burkholderia cepacia, and Alcaligenes faecalis-A. odorans, agar dilution MICs for all strains tested were within 1 dilution of inhibitory (bacteriostatic) levels as determined by time-kill methodology.     

Regional mapping panels for chromosomes 3, 4, 5, 11, 15, 17, 18, and X

The erm family of 23S rRNA adenine-N6-methyltransferases confers resistance to all macrolide-lincosamide-streptograminB (MLS) antibiotics, but not all MLS antibiotics induce synthesis of Erm methyltransferase with equal efficiency in a given organism. The induction efficiency of a test panel of MLS antibiotics was studied by using two translational attenuator-lac reporter gene fusion constructs, one based on ermSV from Streptomyces viridochromogenes NRRL 2860 and the other based on ermC from Staphylococcus aureus RN2442. Four types of responses which were correlated with the macrolide ring size were seen, as follows: group 1, both ermSV and ermC were induced by the 14-membered-ring macrolides erythromycin, lankamycin, and matromycin, as well as by the lincosamide celesticetin; group 2, neither ermSV nor ermC was induced by the 12-membered-ring macrolide methymycin or by the lincosamide lincomycin or the streptogramin type B antibiotic ostreogrycin B; group 3, ermSV was selectively induced over ermC by the 16-membered-ring macrolides carbomycin, chalcomycin, cirramycin, kitasamycin, maridomycin, and tylosin; and group 4, ermC was selectively induced over ermSV by the 14-membered-ring macrolide megalomicin. These data suggest that the leader peptide determines the specificity of induction by different classes of MLS antibiotics and that for a given attenuator, a major factor which determines whether a given macrolide induces resistance is its size.     

Increased-contrast, high-spatial-resolution, diffusion-weighted, spin-echo, echo-planar imaging

An insertable head gradient coil with a maximum gradient amplitude of 45 mT/m and a rise time of 150 musec along all three major axes was used to collect high-spatial-resolution, single-shot, spin-echo, echo-planar, diffusion-weighted magnetic resonance images with b values ranging from 0 to 2,200 sec/mm2. Improvements in spatial resolution allowed better visualization of large white matter tracts and their relation to adjacent anatomic structures. Excellent contrast and anatomic detail were revealed for most structures in the brain when a sufficient number of acquisitions were collected.     

Preparation of gadolinium,terbium, dysprosium,erbium, thulium,and lutecium dicarbides

Summary A study was made of the conditions of preparation of gadolinium, terbium, dysprosium, erbium, thulium, and lutecium dicarbides by the method of vacuum reduction of oxides of the corresponding metals.It was established that 1800°C is the optimum temperature for the preparation of these dicarbides. It is assumed that the formation of the dicarbides at the same temperature is linked with the similarity of the electronic structures of the rare-earth metals.Translated from Poroshkovaya Metallurgiya, No. 8(56), pp. 34–38, August, 1967.     

Radioimmunoassay, its value in clinical use: LH, FSH, progesterone, estrone, estradiol, estriol

The clinical value of hormone determinations and functional tests is presented. In regard to cyclical disruptions, foremost the anovulatory cycle with secondary amenorrhea primarily in mind, the important evaluation is that of the estrogen-gestagen test, followed by a determination of the plasma gonadotropins. For ovarian insufficiency, differential diagnosis between the hypothalamus, hypophysis, or disruptions in the feedback systems are most important. The clomisphene test is the primary means of radioimmunological evaluation of amenorrhea. This test enables one to determine which of the 3 functions above are showing a negative response to chemical stimuli. These tests are of great value in diagnostics and are also useful in evaluating the effectiveness of therapy. The main polemic is over whether it is most useful to evaluate the total estsrogens or the individual fractions. The same problem exists for progesterone. The main indication for the determination of total estogens, or fractions of estrone, estradiol, as well as progesterone is developmental control of medical ovulation release. The therapy of sterility cases also falls into this category. The exact determination of estrogen contents is not always possible, however, making reliability questionable. But the varied nature of their functions and the cost factors involved must remain important in evaluating them.     

Hyperthyroidism. Etiology, physiopathology, diagnosis, evolution, treatment]

Serum amyloid A (SAA) is an acute-phase reactant whose level in the blood is elevated to 1000-fold as part of the body's responses to various injuries, including trauma, infection, inflammation, and neoplasia. As an acute-phase reactant, the liver has been considered to be the primary site of expression. However, limited extrahepatic SAA expression was described in mouse tissues and in cells of human atherosclerotic lesions. Here we describe nonradioactive in situ hybridization experiments revealing that the SAA mRNA is widely expressed in many histologically normal human tissues. Expression was localized predominantly to the epithelial components of a variety of tissues, including breast, stomach, small and large intestine, prostate, lung, pancreas, kidney, tonsil, thyroid, pituitary, placenta, skin epidermis, and brain neurons. Expression was also observed in lymphocytes, plasma cells, and endothelial cells. RT-PCR analysis of selected tissues revealed expression of the SAA1, SAA2, and SAA4 genes but not of SAA3, consistent with expression of these genes in the liver. Immunohistochemical staining revealed SAA protein expression that co-localized with SAA mRNA expression. These data indicate local production of the SAA proteins in histologically normal human extrahepatic tissues.     

电感耦合等离子体原子发射光谱法测定镍基合金中钨、钼、钴、铝、钛、铌、铁元素

针对镍基合金的溶解方法、元素分析谱线的选择、仪器分析参数的优化、内标溶液的选用、基体元素的影响、干扰元素的校正及消除方法等进行了研究,确定了最佳试验条件;试验结果表明:检出限为0.024mg/L～0.85mg/L;加标回收率为97.1%～105.7%;方法的精密度(RSD,n=11)小于1.0%,本试验测定结果与标钢认定值和湿法分析结果做对照,都在允许偏差范围内,表明此方法精密度好,准确度高。     

Thermodynamics of copper matte converting: Part III. Steady-state volatilization of Au,Ag, Pb,Zn, Ni,Se, Te,Bi, Sb,and As from slag,matte, and metallic copper

A comprehensive compilation of various thermodynamic data required for a complete analysis of copper matte converting reactions is presented. The data comprise estimated free energies of formation for such gases as SeO, SeS, TeO, TeS, BiO, BiS, SbO, SbS, AsO, and AsS, as well as activity coefficients in dilute copper alloys and vapor pressures of various elements and compounds. The volatilization of minor elements in steady-state reactors comprising gas and several condensed phases is mathematically formulated, and a parameter which governs the volatilization in such reactors is defined and named volatilization constant. The vapor pressures of various volatile species are calculated thermodynamically for the Noranda Process reactor by assuming equilibrium conditions. The volatilization constants of various minor elements are expressed explicitly as functions of oxygen and sulfur activities. Formerly Associate Professor, Department of Metal-lurgical Engineering, University of Utah, Salt Lake City, UT.     

Harmful dysfunction, disorder, disease, illness, and evolution.

Can psychiatric disorders be conceptualized as "harmful dysfunctions" (J. C. Wakefield, 1992a. 1992b, 1999; S. O. Lilienfeld & L. Marino, 1995)? Wakefield's (1992a) central concept of disorder as "harmful dysfunction" is discussed by placing it in the context of a complementary discussion of disease, illness, the sick role, and evolution (D. F. Klein, 1978). S. O. Lilienfeld and L. Marino (1995) contended that proper biological function cannot be determined. This argument obscures the key significance of involuntary impairment of evolved functions. The claim that the Roschian concept has no counterpart in reality is incorrect and does not support the conclusion that dysfunctions are irreducibly evaluative and therefore arbitrary. J. C. Wakefield's (1999) views in this area are supplemented. The role of monothetic and polythetic categorization, extremal terms, and the concept of normality in nosology is considered. This analysis refutes the implication that deviance and illness are equivalent. The resolution of this debate is practically relevant to emphasizing areas of research investment, such as therapeutics. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

电感耦合等离子体原子发射光谱法测定废旧线路板中砷锑铋锡镍铅铟银镧铈钆钇

采用硝酸和盐酸溶解样品, 电感耦合等离子体原子发射光谱法(ICP-AES)测定了废旧线路板中砷、锑、铋、锡、镍、铅、铟、银、镧、铈、钆和钇12种元素。对硝酸和盐酸的用量、分析谱线的选择、基体的影响和仪器参数等进行了研究, 确定了实验的最佳测定条件。通过加标回收试验和采用电感耦合等离子体质谱(ICP-MS)法进行对照分析, 验证了方法的可靠性和准确性。试验表明, 方法适用于废旧线路板中砷、锑、铋、锡、镍、铅、铟、银、镧、铈、钆和钇的测定。方法的检出限(3s)为0.000 9~0.04 μg/mL, 测定样品的相对标准偏差(n=5)在0.58%~4.6%之间, 加标回收率在85%~104%范围。     

Earnings, education, genetics, and environment

A major and well-recognized difficulty in estimating the effects of education on earnings is that the more educated are likely to be more able, irrespective of education. If ability also determines earnings and is not controlled, ordinary least squares will yield biased estimates of the education coefficient. In this study, we use data on identical twins to control for differences in ability that arise from genetic endowments and family environment. Not controlling for genetics and family environment may cause a large bias, up to two-thirds of the noncontrolled coefficient.     

Analysis of mepivacaine, bupivacaine, etidocaine, lidocaine, and tetracaine

A GLC method, employing a nitrogen-phosphorus-sensitive detector, is described for the analysis of mepivacaine, bupivacaine, etidocaine, lidocaine, and tetracaine in biological fluids. The method is simple, reliable, and sensitive, with a practical limit of sensitivity of approximately 2.5 ng/ml, well below therapeutic plasma levels. Extensive start-up procedures and sample preparation are not required.     

Relation of benzodiazepine use to the risk of selected cancers: breast, large bowel, malignant melanoma, lung, endometrium, ovary, non-Hodgkin's lymphoma, testis, Hodgkin's disease, thyroid, and liver

Some animal data have raised the possibility that benzodiazepines influence the risk of selected cancers. With data collected in 1977-1991 in a US hospital-based study, the authors assessed the relation of benzodiazepine use to the risk of 11 cancers: breast (6,056 patients), large bowel (2,203), malignant melanoma (1,457), lung (1,365), endometrium (812), ovary (767), non-Hodgkin's lymphoma (382), testis (314), Hodgkin's disease (299), thyroid (111), and liver (37). Cases were compared with cancer controls (3,777 patients with other cancers) and noncancer controls (1,919 patients admitted for acute nonmalignant disorders). Relative risks were estimated for benzodiazepine use at least 4 days a week for at least 1 month, initiated at least 2 years before admission (sustained use) by multiple logistic regression with control for confounding factors. Results derived with noncancer controls were similar to those derived with cancer controls. For sustained benzodiazepine use relative to no use, relative risk estimates for all 11 cancers were compatible with 1.0 at the 0.05 level of significance. Relative risk estimates for durations of at least 5 years were also compatible with 1.0, with the exceptions of an increased estimate, of borderline statistical significance, for endometrial cancer, and a decreased estimate for ovarian cancer. Relative risk estimates both for sustained use that continued into the 2-year period before admission and for sustained use that ended up to > or = 10 years previously were compatible with 1.0, suggesting a lack of tumor promotion and no increase in the risk after a latent interval. Results were also null for diazepam, chlordiazepoxide, and other benzodiazepines considered separately. The results suggest absence of association between benzodiazepine use and the cancers considered, with the evidence stronger for the cancers with larger numbers of subjects. The similarity of results derived with cancer and noncancer controls suggests that benzodiazepines do not influence the risk of cancer as a whole.     

Isolation of eukaryotic ribosomal proteins. Purification and characterization of the 40 S ribosomal subunit proteins Sa, Sc, S3a, S3b, S5', S9, S10, S11, S12, S14, S15, S15', S16, S17, S18, S19, S20, S21, S26, S27', and S29

The proteins of the small subunit of rat liver ribosomes were separated into five main groups by stepwise elution from carboxymethylcellulose with LiCl at pH 6.5. Twenty-one proteins (Sa, Sc, S3a, S3b, S5', S9, S10, S11, S12, S14, S15, S15', S16, S17, S18, S19, S20, S21, S26, S27', and S29) were isolated from three groups (A40, C40, and D40) by ion exchange chromatography on DEAE-cellulose, carboxymethylcellulose, and phosphocellulose and by filtration through Sephadex. The amount of protein obtained varied from 0.1 to 11 mg. Six of the proteins (S5', S10, S11, S18, S19, and S27') had no detectable contamination; the impurities in the others were no greater than 9%. The molecular weight of the proteins was estimated by polyacrylamide gel electrophoresis in sodium dodecyl sulfate; the amino acid composition was determined.     

Isolation of eukaryotic ribosomal proteins. Purification and characterization of 60 S ribosomal subunit proteins L3, L6, L7', L8, L10, L15, L17, L18, L19, L23', L25, L27', L28, L29, L31, L32, L34, L35, L36, L36', and L37'

The proteins of the large subunit of rat liver ribosomes were separated into seven groups by stepwise elution from carboxymethylcellulose with LiCl at pH 6.5. Twenty-one proteins (L3, L6, L7', L8, L10, L15, L17, L18, L19, L23', L25, L27', L28, L29, L31, L32, L34, L35, L36, L36', and L37') were isolated from three groups (C60, E60, and F60) by ion exchange chromatography on carboxymethycellulose and by filtration through Sephadex. The amount of protein obtained varied from 0.3 to 25 mg. Nine of the proteins (L6, L8, L18, L27', L28, L29, L34, L36, and L36') had no detectable contamination: the impurities in the others were no greater than 9%. The molecular weight of the proteins was estimated by polyacrylamide gel electrophoresis in sodium dodecyl sulfate; the amino acid composition was determined.     

精炼渣钙组分乙酸浸出制备钙基CO2吸附材料

关键词： CO2; 高炉煤气; 乙酸浸出; 钙基吸附剂; 精炼渣     

Alteration of proteins regulating apoptosis, Bcl-2, Bcl-x, Bax, Bak, Bad, ICH-1 and CPP32, in Alzheimer's disease

Recently, apoptosis has been implicated in the selective neuronal loss of Alzheimer's disease (AD). Apoptosis is regulated by the B cell leukemia-2 gene product (Bcl-2) family (Bcl-2, Bcl-x, Bax, Bak and Bad) and the caspase family (ICH-1 and CPP32), with apoptosis being prevented by Bcl-2 and Bcl-x, and promoted by Bax, Bak, Bad, ICH-1 and CPP32. In the present study, we examined the levels of these proteins in the membranous and cytosolic fractions of temporal cortex in AD and control brain. In the membranous fraction, the levels of Bcl-2 alpha, Bcl-xL, Bcl-x beta, Bak and Bad were increased in AD. In the cytosolic fractions, the level of Bcl-x beta was increased, while Bcl-xL, Bax, Bak, and Bad and ICH-1L were unchanged. CPP32 was not detected in AD or control brain. These findings demonstrate a differential involvement of cell death-regulatory proteins in AD and suggest that Bak, Bad, Bcl-2 and Bcl-x are upregulated in AD brains.     

阴极极化对10Ni9CrMoV高强钢氢脆敏感性的影响

关键词： 10Ni9CrMoV钢;阴极极化;氢脆;高强钢;SSRT     

White, European, Western, Caucasian, or what? Inappropriate labeling in research on race, ethnicity, and health

The request for scientifically appropriate terminology in research on race, ethnicity, and health has largely bypassed the term White. This and other words, such as Caucasian, are embedded in clinical and epidemiological discourse, yet they are rarely defined. This commentary analyzes the issue from the perspective of the epidemiology of the health of minority ethnic and racial groups in Europe and the United States. Minority groups are usually compared with populations described as White, Caucasian, European, Europid, Western, Occidental, indigenous, native, and majority. Such populations are heterogeneous, the labels nonspecific, and the comparisons misleading. Terminology that reflects the research purpose-for examples, reference, control, or comparison--is better (unlike White, these terms imply no norm, allowing neither writers nor readers to make stereotyped assumptions about the comparison populations. This paper widens the debate on nomenclature for racial and ethnic groups. Many issues need exploration, including whether there is a shared understanding among the international research community of the terms discussed.