Qualitative observations on the diffusion of copper and gold through a nickel barrier

To retard failure of gold plated copper parts by diffusion of copper to the gold surface, a layer of nickel is frequently used between the copper and gold as a diffusion barrier. To evaluate the mechanisms whereby the nickel retards the motion of copper atoms to the gold surface, planar tri-couples of Cu/Ni/Au were prepared by electroplating nickel and gold layers on OFHC copper coupons. Diffusion anneals were carried out at temperatures from 150 to 750°C. A qualitative evaluation of diffusion behavior was provided by an electron microprobe utilizing X-ray wavelength dispersive analysis on polished cross sections. Results demonstrate that the nickel layer retards but does not block the transport of copper to the gold surface. Possible mechanisms for the anomalous buildup of copper at the gold/nickel interface and gold at the copper/nickel interface are discussed.     

Picosecond time-interval measurement and intensity correlations using the two-quantum photoelectric effect

A technique based on the two-quantum photoeffect has been used to measure second-order intensity correlations, pulse shapes from a mode-locked argon ion laser, and time delays in the picosecond domain. Good agreement was obtained between the mode distribution computed from the intensity autocorrelation data and that observed with a scanning Fabry-Perot when the laser was run in the mode-locked condition. Additionally, the contrast ratios observed in both the mode-locked and free-running condition were in good agreement with a theory by Weber and Danielmeyer.     

CW gain measurements in small-bore argon-ion laser discharges using a novel modulation technique

A technique for small-signal gain measurements for CW laser systems is described. The method is applied to the measurement of multimode small-signal gain coefficients of small-bore argon-ion laser transitions.     

５２２例肺部病变CT引导经皮切割针活检总结

目的总结CT引导经皮切割针穿刺活检术对肺部病变诊断的准确性、灵敏度、特异度和并发症。方法收集１９９２年以来,取材成功并有完整资料的５２２例CT引导经皮肺部切割针穿刺活检病例作回顾性分析。其中肺部结节或肿块性病变４６７例,其他病变５５例。统计该法诊断灵敏度、特异度和并发症,并分析其影响因素。结果４７６例获得组织标本并有病理学结果,取材成功率为９１．２％（４７６／５２２）。３０１例病理确诊为恶性肿瘤,包括腺癌１０７例,鳞状细胞癌８４例,不能分型恶性肿瘤５９例,小细胞未分化癌１６例,肺转移瘤２２例,低度恶性肿瘤３例,肺肉瘤３例,细支气管肺泡细胞癌２例,５例病理报告为“癌变可疑”,后证实为支气管肺癌。１７例穿刺病理为“癌变可疑”,后证实为良性病变。穿刺未发现癌细胞者２０４例,其中明确诊断为良性病变１０２例（结核４１例,非特异性肺炎２１例,慢性炎症１８例,支气管扩张７例,炎性假瘤６例,曲霉感染５例,隐球菌性肺炎３例,良性纤维组织细胞瘤１例）。非特异性病理结果的良性病变７３例。另２９例穿刺未发现肿瘤组织,而后证实为恶性肿瘤,系假阴性。阳性预测值为９４．７％〔３０１／（３０１＋１７）〕,灵敏度为９１．２％〔３０１／（３０１＋２９）〕,特异度为９１．１％〔１７５／（１７５＋１７）〕,假阴性率为１４．２％（２９／２０４）。５４例发生气胸,占１０．３％（５４／５２２）,仅１．５％的病例（８／５２２）行抽气或置管闭式引流处理。肺出血４２例,咯血３６例,均未经特殊处理而自愈。结论CT引导经皮切割针肺部病灶活检具有较高的诊断灵敏度和特异度,有助于提高良性病变的诊断准确性,同时并不显著增加气胸和出血等并发症的发生率。     

Micronutrient mineral and folate content of Australian and imported dried fruit products

A selection of Australian and imported fresh and dried fruit products, including sultanas, Sunmuscats, Carina currants, Zante currants, apricots, and prunes, were analyzed for selected minerals (Ca, Mg, Na, S, B, Al, Fe, Mn, Cu, Zn, Mo, and Se), folate and vitamin C, and the capacity of dried fruits for dietary provision of these micronutrients evaluated. Micro-nutrients were concentrated by a factor of 3-5 in dried fruits compared with their fresh fruit counterparts and were consequently present in nutritionally significant levels, in contrast to fresh fruit. Australian dried sultanas, Carina currant, Zante currant, apricots, and prunes contained Cu, Fe, K, and Mn at levels of >20% of daily Required Dietary Intake (RDI, taken as the average for adult men and women as nominated by the Australian National Health and Medical Research Council) and Sunmuscats contained Cu, Fe, and K at >20% of RDI. All dried fruits studied contained boron in the range of 1.5 to 5.4 mg per 100 g; however, the RDI for boron has not been defined by the NHMRC at the present time. All sultanas and currants studied contained folate at levels of 10-20% of RDI per 100 g. Experimental drying methods significantly affected folate levels with higher folate content in non-ground versus ground-based drying methods. Of the micro-nutrients supplying >20% of RDI, folate represents a particular nutrient for which the mean daily intake of adult Australians is typically inadequate. This study shows that dried fruit consumption, in contrast with fresh fruit, can provide significant proportions of daily requirements of several micronutrients, particularly folate.     

Evaluation of potential human health risk associated with consumption of edible products from livestock fed ration supplemented with Red Lake Diatomaceous Earth

ABSTRACT

Red Lake Diatomaceous Earth (DE) is a naturally occurring blend of diatomaceous earth and calcium bentonite that can be used as an anti-caking agent in animal feed and contains naturally occurring dioxins. A quantitative risk assessment was conducted to assess potential human health risk associated with consumption of edible tissues from livestock exposed to dioxins via feed containing Red Lake DE. Empirical data characterising the transfer of dioxins to eggs and other tissues in chickens demonstrate that resulting concentrations in eggs are lower than those found in the general food supply. These data also provided product-specific input for a risk assessment conducted both with default parameters and with media-specific input from the feed study. Results demonstrate that exposure to dioxins in edible tissue from livestock that consumed Red Lake DE in feed would not be associated with an increased risk to humans. Findings from this assessment highlight the utility and importance of accounting for bioavailability as part of health-based risk assessment and provide information critical to risk managers in determining the safe use of Red Lake DE as an anticaking agent in livestock and pet feed.     

Monitoring nonlactating cow intramammary infection dynamics using DHI somatic cell count data

Although the nonlactating period presents a risk for intramammary infection, efficient systems to monitor infection status of recently calved cows have not been developed, and benchmarks for interpretation have not been established. Individual cow somatic cell count (SCC) data for the current and previous six monthly Dairy Herd Improvement milk tests and the last SCC of the previous lactation and first SCC of the current lactation were summarized for all milking cows in a selection of Wisconsin dairy herds. Prevalence of infection, herd new infection rate, fresh cow contribution to herd new infection rate, dry cow new infection rate, heifer new infection rate, and dry cow cure rate were estimated using a threshold of 200,000/ml. In 145 herds, mean (range) heifer new infection rate was 21.3% (0 to 58%). The cut-point for the 10th percentile of herds was 8%. Mean (range) dry cow new infection rate in cows that were uninfected at the last test before dry off was 22.4% (0 to 71%), and the cut-point for the 10th percentile of herds was 9%. Although nonlactating cow and heifer new infection rates increased with weighted 6-mo mean herd SCC, the between-herd variation was large, suggesting that on-farm factors are important in determining the rates of infection. In a subset of 51 Wisconsin dairy herds, significant monthly variation in weighted SCC, prevalence, herd new infection rate, and fresh cow contribution to herd new infection rate were detected. Elevations in SCC and prevalence of infection during the summer (July through September) were associated with significant increases in fresh cow and herd new infection rates.     

症状性颅内动脉狭窄支架成形术后早期新发缺血性脑损害的临床研究

目的分析症状性颅内动脉狭窄支架成形术后早期发生的缺血性脑损害情况,探讨颅内动脉狭窄支架成形术的早期疗效和安全性。方法对２９例症状性颅内动脉狭窄行WingSpan支架成形术治疗的患者,在支架成形术前、术后（７２h内）行弥散磁共振成像（DWI ）检查,结合患者一般临床情况、手术情况、新发缺血性脑损害等资料,以NIHSS评分评价神经系统障碍严重程度,系统评价WingSpan支架成形术治疗颅内动脉狭窄早期的安全性和疗效。结果支架成形术患者术前及术后即刻平均狭窄分别为（７２．３±１０．７）％与（２９．５±１３．９）％。并发症发生率为１７．２％,神经系统并发症２例（６．９％）。DWI 检出的新发缺血性脑损害１３例（４４．８％）,其中无症状者１１例（８４．６％）。１３例中共检出新发缺血性脑损害病灶６３个,其中５５个（８７．３％）位于靶血管供血区域,８个（１２．７％）位于非靶血管供血区域。２个（３．２％）出现在支架覆盖血管相关穿支供血区域。永久神经功能障碍的并发症率为０,无病死率。结论DWI 检查在评价颅内动脉狭窄支架成形术中的安全性具有重要参考价值。应用WingSpan支架系统治疗症状性颅内动脉狭窄围手术期安全有效。术后早期有一定比率的缺血性脑损害发生,尽管大部分是无症状的,但应引起临床医师的重视。