钼蓝光度法测定铬铁中硅

以Na2 O2 Na2 CO3在刚玉坩埚或Na2 CO3 K2 CO3 H3BO3在铂坩埚中熔样 ,盐酸酸化 ,用钼蓝光度法测定铬铁中 5.0 %以下的硅量 ,方法简单快速 ,精密度和准确度均令人满意     

Recombinant or plasma-derived antisecretory factor inhibits cholera toxin-induced increase in Evans blue permeation of rat intestinal capillaries

The effect of cholera toxin on small intestinal capillary function, utilizing the Evans blue dye method, was analyzed. The modulatory influence of plasma-derived or recombinant human antisecretory factor on this variable was also investigated. Male Sprague-Dawley rats were briefly anesthetized with ether, and a jejunal loop was constructed that was challenged for 90 min with phosphate-buffered saline or cholera toxin. Five minutes prior to death, the rats received an intravenous injection of Evans blue. The tissue content of dye in the loop was quantitated spectrophotometrically or demonstrated histochemically. Cholera toxin increased the recovery of Evans blue; extravasation of the dye was prominent in the top of the villi, while the crypts were spared. It is suggested that the toxin caused increased transcapillary permeation of albumin in a heterogenous fashion in the gut wall. This effect of the toxin was prevented by pretreatment with the antisecretory factor.     

实验室废旧贵金属材料中铂的回收利用

实验室使用的含铂耗材会因为长时间使用形成损耗、变性或功能失效,长期搁置或丢弃造成极大的浪费,工业上常使用硼氢化钠作还原剂还原回收铂。实验依据硼氢化钾相比硼氢化钠具有分解温度高、稳定性好、在使用过程中较安全的特性,与氯化铵相结合利用二次沉淀法,以实验室含铂废旧耗材为原料,建立了硼氢化钾还原-氯化铵沉淀法回收铂的方法。为了获得纯净的金属铂,实验采用硝酸分离杂质元素,王水溶解铂,反复用盐酸驱赶氮氧化物,使铂充分转化为氯铂酸。在40℃、5%(V/V)盐酸介质中用硼氢化钾还原氯铂酸及少量难溶于王水的氧化铂,再用王水溶解铂黑并完全转化为氯铂酸,氯铂酸与过量的氯化铵形成黄色氯铂酸铵沉淀,陈化过夜。选择分段缓慢升温分解氯铂酸铵,在750℃和900℃煅烧,分别获得松散的金属铂粉和较致密的金属铂。两次沉淀溶液中残余的铂离子均小于20μg/mL。回收铂的纯度不小于99.9%,回收率大于99.5%。     

Ultrastructure of the secretory cells of the submucosal glands in the human maxillary sinus

Tissue samples obtained from the lateral wall of the maxillary sinuses of five patients were examined by light microscopical, histochemical, and ultrastructural techniques. Submucosal glands were tubulo-alveolar mixed glands. The acini consisted of either all serous or all mucous cells, or a mixture of both. Serous granules were stained by toluidine blue, or by hematoxylin and eosin (H and E), but showed little or no reaction with periodic acid-Schiff (PAS) or Alcian blue. Mucous granules were pale in toluidine blue or H and E preparations, and consisted primarly of acid mucosubstances, as demonstrated by their staining reaction with PAS and Alcian blue. At the electron microscope level, the serous granules were either homogeneously dense, or showed a substructure consisting of at least two layers of distincly different electron-opacity. Typical mucous droplets consisted of a fibrillar network dispersed in a translucent matrix. A second secretory product was present in the mucous cells in the form of elongated, membrane-bounded structures containing numerous parallel filaments, which measured about 55 A in diameter. The mucous droplets and the filamentous bodies appear to arise from the opposite faces of the Golgi complex in the mucous cells. The filamentous bodies showed a pronounced tendency to fuse with the mucous droplets. All acini were surrounded by a well-defined myoepithelial layer and contained intercellular nerve terminals.     

密度法检测金、铂含量的研究

本文通过贵金属金、铂合金配比，密度法测试百分含量与化学分析及仪器检测百分含量进行比较，测试结果准确度达到０．２％。同时显示出含量、密度、Ｋ金三者之间的关系，总结密度与含量基本规律，获得试验结果。     

Clinical development of platinum complexes in cancer therapy: an historical perspective and an update

The vast amount of basic research on platinum coordination complexes has produced, over the past 25 years, several thousand new molecules for preclinical screening and 28 compounds which have entered clinical development. The goals of these research activities have been to identify compounds with superior efficacy, reduced toxicity, lack of cross-resistance or improved pharmacological characteristics as compared with the parent compound, cisplatin. After the remarkable therapeutic effects of cisplatin had been established, only a few other platinum compounds succeeded in reaching general availability. Whereas carboplatin is an analogue with an improved therapeutic index (mostly driven by reduced organ toxicity) over that of cisplatin, new compounds clearly more active than or non-cross-resistant with cisplatin have not yet been identified. The platinum analogues that remain under investigation are focusing on expanding the utilisation of platinum therapy to tumour types not usually treated with, or responsive to, cisplatin or carboplatin. In addition, novel routes of administration constitute another avenue of research. The clinical development of platinum coordination complexes, with emphasis on those compounds still under active development, is reviewed.     

2002年铂市场观察与思考

2001年钯价格高涨,铂、钯相差一倍的价格推动着汽车工业中铂的消费增长,加之中国首饰业用铂量的继续攀升,2002年全球铂市场连续第四年供应短缺,缺口增加到49万盎,全年的平均价为539.13美元/盎司,比2001年上涨1.9％。未来,鉴于世界汽车尾气排放标准的日益严格,铂在汽车工业中的应用如日中天;首饰业消费也将继续增长;而供应由于南非Anglo公司产量的调低,有可能加剧市场的短缺。估计2003年的铂价将高位盘整,预计年平均价在578美元/盎司。     

meso-1,2-bis(2,6-dichloro-4-hydroxyphenyl)ethylenediamine]- dichloroplatinum(II), a new drug not only parenterally but also orally active in the therapy of breast and prostate cancer

The platinum complex [meso-1,2-bis(2,6-dichloro-4-hydroxyphenyl)- ethylenediamine]dichloroplatinum(II),K, was tested for its antitumor activity on hormone-sensitive tumor models under peroral administration. The resorption from the gastrointestinal tract was proved by determining the estrogenic effect of K in a dose/activity study using the immature-mouse uterine weight test. In comparison to the subcutaneous injection, a tenfold peroral dose was administered to achieve identical effects. By peroral treatment of the hormone-sensitive MXT(M3.2) mammary carcinoma of the mouse with K an almost complete inhibition of the tumor growth was obtained. This effect was superior to that of subcutaneously applied cisplatin and significantly better than that obtained by perorally administered ligand L at an equimolar dose, indicating that the antitumor effect is caused by the intact complex K and not by the liberated ligand L. The strong antitumor activity of perorally applied K was also demonstrated on the hormone-sensitive Noble Nb-R prostatic carcinoma of the rat. Histological examinations showed that the platinum complex K did not cause cisplatin-like kidney damage or irritations of gastric or intestinal mucosa when given perorally.     

Consolidation/maintenance chemotherapy for ovarian cancer

A recently reported randomized trial has demonstrated that administration of single-agent paclitaxel to women with advanced ovarian cancer who attain a clinically defined complete response to platinum/paclitaxel-based chemotherapy can substantially improve progression-free survival. Whether this strategy will improve overall survival in this clinical setting remains uncertain.     

Platinum, palladium, and gold extraction from Coronation Hill ore by cyanidation at elevated temperatures

The effects of cyanidation conditions (pH, time, temperature and particle size of the ore) on the extraction of platinum, palladium, and gold from a quartz-feldspar porphyry sample from the Coronation Hill deposit, Australia, were studied. The main precious metal minerals in the sample were identified as coarse and fine native gold, native platinum and palladium, stibiopalladinite and palladium-platinum-iron alloy phases.Coarse gold, but no platinum or palladium, was recovered by amalgamation. At ambient temperature, for material 80% - 74 μm and a cyanidation time of 48 h, reducing the cyanidation pH from 11.5 to 9.5 increased the palladium extraction from 22.7 to 66.4% and the platinum extraction from 5.7 to 25.7%. Total gold extractions were not affected and were over 98%. Finer grinding increased the palladium extractions but had little effect on platinum extractions, and decreased gold extractions by a few percent.Cyanidation at elevated temperatures of up to 150°C under an overpressure of nitrogen, air, or oxygen increased the palladium and platinum extraction values. The optimum temperature range was 100–125°C. At 100°C under air, 87–92% of the palladium, 73–79% of the platinum, and 95–97% of the gold were extracted in 4–6 h at pH 9.5–11.5.Possible treatment options involving cyanidation at ambient and elevated temperatures, with or without flotation, for recovery of gold, platinum, and palladium are discussed.     

金尾矿选矿试验中二氧化硅快速测定

测定了选矿试验中大批量样品二氧化硅含量。用价格低廉的银坩埚取代昂贵的铂坩埚，可同时分析大批样品；用氢氧化钠熔样，温度相对碳酸钠要低很多，可节省时间；在两次盐酸蒸干重量法中，省去了氢氟酸挥发和钼蓝比色法分析滤液中剩余的微量二氧化硅两步。从与冶金堪探院测定结果对比和物料衡算结果上看，测定准确可靠，为选矿方案的制定提供了依据。     

化学镀铂法制备质子交换膜燃料电池膜电极

用化学镀铂法制备质子交换膜燃料电池膜电极,提出了膜电极的微观结构模型及膜电极的化学铂机理。通过考察镀铂工艺对膜电极性能的影响,确定了化学镀铂法制备肛电极的最佳工艺条件：在Ｎａｆｉｏｎ１１７膜的两无镀上一层铂,压上碳黑或碳载铂,然后用低浓度的与氯铂酸等浓度的肼溶液化学镀铂     

Importance of multiagent chemotherapy regimens in ovarian carcinoma: dose intensity analysis

BACKGROUND: In the previous meta-analysis of dose intensity (dosage) of chemotherapy in advanced ovarian cancer, we analyzed data on cyclophosphamide, altretamine (hexamethylmelamine), doxorubicin, and cisplatin. Only cisplatin showed statistically significant association of complete and partial clinical response with dose intensity. PURPOSE: This analysis updates the previous results and further characterizes response to cisplatin alone or in multiagent regimens. METHODS: We analyzed data from 18 regimens containing platinum (cisplatin or carboplatin) that were used in nine new randomized trials, in addition to data from the 60 groups of patients in our previous study in which responses were reported. Relative dose intensity was calculated as a fraction of the dosage of a drug in the standard regimen of cyclophosphamide, altretamine, doxorubicin, and platinum (CHAP). We performed single and multiple regression analyses to determine the relationship between disease outcome and relative dose intensity for cyclophosphamide, platinum, and doxorubicin alone or in combination. RESULTS: The association between outcome and dose intensity for platinum alone or in multiagent regimens was statistically significant. This association was of borderline significance for cyclophosphamide alone but was not significant for this drug in multiagent regimens. There were insufficient data to test the relationship for doxorubicin as a single agent, but in multiagent regimens, the relationship was borderline (P = .05). Multiagent regimens containing platinum produced greater response rates than platinum alone for any fixed, planned relative dose intensity for platinum. CONCLUSIONS: Our results support other published findings that use of cyclophosphamide and doxorubicin increases the efficacy of single-agent platinum. Relative dose intensity values for cyclophosphamide used alone were larger than those used in multiagent regimens, which might explain why the relationship between relative dose intensity and outcome for cyclophosphamide was not significant for use in multiagent regimens. Similarly, none of the multiagent regimens incorporated doxorubicin at a relative dose intensity for which the drug is found to be effective as a single agent. IMPLICATIONS: Prospective clinical trials are required to test the effect of higher relative dose intensity for doxorubicin and cyclophosphamide added to platinum in advanced ovarian cancer. An important element in the design of prospective trials will be to test for the relative importance of dose intensity versus total dose. This testing is best achieved in a three-arm study design such as that reported in adjuvant treatment of stage II breast cancer conducted by the Cancer and Leukemia Group B.     

Chemotherapy in advanced ovarian cancer: four systematic meta-analyses of individual patient data from 37 randomized trials. Advanced Ovarian Cancer Trialists' Group

The purpose of this systematic study was to provide an up to date and reliable quantitative summary of the relative benefits of various types of chemotherapy (non-platinum vs platinum, single-agent vs combination and carboplatin vs cisplatin) in the treatment of advanced ovarian cancer. Also, to investigate whether well-defined patient subgroups benefit more or less from cisplatin- or carboplatin-based therapy. Meta-analyses were based on updated individual patient data from all available randomized controlled trials (published and unpublished), including 37 trials, 5667 patients and 4664 deaths. The results suggest that platinum-based chemotherapy is better than non-platinum therapy, show a trend in favour of platinum combinations over single-agent platinum, and suggest that cisplatin and carboplatin are equally effective. There is no good evidence that cisplatin is more or less effective than carboplatin in any particular subgroup of patients.     

Sequence dependence of the hyperthermic potentiation of carboplatin-induced cytotoxicity and intracellular platinum accumulation in HeLa cells

We have examined the enhancement of cytotoxic effects of cis-diammine-1,1-cyclobutane dicarboxylate platinum(II) (carboplatin) by hyperthermia in HeLa cells using different regimes of timing and sequence. The results were compared with those obtained with cis-diamminedichloroplatinum(II) (cisplatin). We found that cisplatin simultaneously combined with heat was the most cytotoxic toward HeLa cells of the various timing and sequencing conditions studied. On the other hand, for carboplatin, drug treatment immediately following or during heat exposure showed the greatest effect. Intracellular platinum concentration in HeLa cells treated with heat before carboplatin showed a 2.75-fold increase over that in cells treated with the drug alone. The ratios for carboplatin given before, or during heating, were 0.67 and 1.42 respectively. Simultaneous exposure of cells to cisplatin and heat led to a 1.64-fold enhancement in cisplatin accumulation, compared to 0.92- and 1.24-fold increase for cells treated with cisplatin before and after heat respectively. Although each drug exposure prior to heat was less cytotoxic toward HeLa cells than any other heat/drug combination sequences, the platinum concentration was less than seen with each drug alone. Even though heat exposure prior to and during carboplatin showed a similar toxicity, platinum concentration in cells treated with heat prior to carboplatin was higher than that in cells treated with heat and carboplatin simultaneously. Thus, increased cytotoxicity cannot always be explained on the basis of intracellular platinum concentration. It is clear however that, differing from cisplatin, exposure of cells to heat prior to or during carboplatin administration results in the greatest cell kill.     

难溶氧化铂中铂的测定

研究了将难溶氧化铂通过水合肼还原成海绵铂,用王水溶解海绵铂,采用氯化铵沉淀法测定铂,从而建立了难溶氧化铂中铂含量的测定方法。对还原剂的选择、还原温度、还原酸度、还原后沉淀过滤洗涤方式及共存元素的干扰等条件进行了一系列实验,解决了难溶氧化铂中铂测定的难题。该方法易于操作,准确度高。将该方法应用于5个不同品位难溶氧化铂样品中铂的测定,相对标准偏差（RSD）为0．10％～0．30％（n=9）。采用该方法测定基准物质氧化铂（PtO2·H2O）中的铂含量,测定值和标准值相符合,从而证明该方法的可行性和可靠性。     

铂丝退火过程中的微观形貌演变和位错密度研究

铂丝的微观形貌和位错密度与退火工艺密切相关,研究铂丝退火过程中微观形貌和位错密度的变化,可以优化退火工艺和提高铂丝电阻性能,为研发高性能铂电阻温度计提供支撑。研究表明:初始铂丝表面有黑色斑驳区域和划痕,有自生颗粒和外来颗粒。随着退火时间的延长,铂丝表面的黑色斑驳区域和划痕消失。退火过程中,铂晶粒晶界处的铂原子很不稳定,逐渐与碳原子形成含Pt和C的颗粒,晶界则变宽边深,产生许多孔隙;随着退火时间的延长,铂丝主体中的杂质元素只剩下C。初始铂丝晶粒的内部和晶界处均存在大量的位错,位错密度达到3.69×10^12 cm^-2,经历退火热处理后晶粒内部和晶界处的位错大量消失。铂丝被充分退火后,位错密度低至无法测出。     

D—992离子交换树脂吸附和解吸铂的性能研究

较系统地研究了D 992新功能阴离子交换树脂吸附、解吸铂的条件。试验结果表明 ,该树脂对铂有较好的吸附和解吸性能 ,应用前景广阔。     

Distribution and characterization of proteoglycans associated with exfoliation material

PURPOSE: To examine the distribution of proteoglycans in the exfoliation materials in order to investigate the nature of the materials. METHODS: The anterior parts of two eyes with exfoliation syndrome were examined by electron microscopy after staining with cupromeronic blue (cmb). Some specimens were treated with enzymes and/or nitrous acid prior to staining. The effects of the enzymes were evaluated statistically by counting the density of the cmb-positive filaments in the exfoliation materials, using a computer. One eye with exfoliation syndrome stained with alcian blue was observed with light microscopy. RESULTS: Exfoliation materials were observed along the epithelial cells of the iris and ciliary body, and in the trabecular meshwork and zonules. In tissue specimens treated with cmb, electron-dense filaments were seen associated with the exfoliation materials. Microfibrils in the trabecular meshwork and iris, and zonular fibrils themselves were free of any filament staining, while the exfoliation materials located closely to the fibrils contained the electron-dense filaments. In the tissue specimens treated with chondroitinase AC, chondroitinase B, chondroitinase ABC or nitrous acid before cmb staining, the amount of the filament associated with exfoliation materials decreased in comparison to the controls. Digestion with keratinase did not demonstrate any significant changes in staining. A combination treatment with chondroitinase ABC and nitrous acid eliminated almost all filaments associated with the exfoliation materials. In the eye stained with alcian blue, the zonules that did not stain for the dye demonstrated an accumulation of exfoliation materials that stained strongly for alcian blue. CONCLUSIONS: Exfoliation materials contain chondroitin sulfate, dermatan sulfate, heparan sulfate proteoglycans. Depositions of proteoglycans on the microfibrils may be closely associated with the formation of exfoliation materials.     

铂市场状况和分析

本文简述了铂市场和世界铂资源状况,介绍了铂供应、消费及价格等方面的情况,并对铂市场进行了分析和预测。