Microscopical imaging of hydroxyapatite/mica composite and packed hydroxyapatite structure--an atomic force microscopy investigation

A focus on the importance of leisure in the development of student nurses has been neglected in the 1990s. This study considers 444 prospective nurses on conventional, diploma and degree courses in two areas of England. It examines their activities associated with socializing, their social support networks and their use of clubs, sports and hobbies before entering nursing. It is evident that students enter nurse training with a wide variety of leisure experiences. Changing recruitment patterns and the structure of nurse training has an effect on the leisure needs of prospective nurses which must be addressed.     

Fibrinolytic variables and cardiovascular prognosis in patients with stable angina pectoris treated with verapamil or metoprolol. Results from the Angina Prognosis study in Stockholm

BACKGROUND: Disturbed fibrinolytic function may influence the progression of coronary atherosclerosis and contribute to thrombotic cardiovascular (CV) events. METHODS AND RESULTS: In the Angina Prognosis Study in Stockholm (APSIS), patients with stable angina pectoris were studied prospectively during double-blind treatment with metoprolol or verapamil. Various measures of fibrinolytic function were studied in 631 (of 809) patients. During a median follow-up time of 3.2 years (2132 patient-years), 32 patients suffered a CV death, 21 had a nonfatal myocardial infarction (MI), and 77 underwent revascularization. Plasma levels of tissue plasminogen activator (TPA) activity and antigen (ag), plasminogen activator inhibitor (PAI-1) activity at test, and TPA responses to exercise were determined at baseline and after 1 month's treatment and were related to subsequent fatal and nonfatal CV events. Univariate Cox regression analysis revealed that elevated levels of TPA-ag at rest (P < .05), high PAI-1 activity (P < .05), and low TPA-ag responses to exercise (P < .05) were associated with increased risk of subsequent CV death. After adjustment for baseline risk factors, TPA-ag independently predicted CV death or MI. In addition, PAI-1 activity independently predicted CV death or MI in male patients. Verapamil treatment was associated with a 10% decrease of TPA-ag levels and metoprolol treatment with a 2% increase (P < .001 for treatment difference). CONCLUSIONS: Plasma TPA-ag levels at rest, and among male patients PAI-1 activity as well, independently predict subsequent CV death or MI in patients with stable angina pectoris.     

Vector-entropy optimization-based neural-network approach to imagereconstruction from projections

In this paper we propose a multiobjective decision making based neural-network model and algorithm for image reconstruction from projections. This model combines the Hopfield's model and multiobjective decision making approach. We develop a weighted sum optimization based neural-network algorithm. The dynamical process of the net is based on minimization of a weighted sum energy function and Euler's iteration, and apply this algorithm to image reconstruction from computer-generated noisy projections and Siemens Somatson DR scanner data, respectively. Reconstructions based on this method is shown to be superior to conventional iterative reconstruction algorithms such as the multiplicate algebraic reconstruction technique (MART) and convolution from the point of view of accuracy of reconstruction. Computer simulation using the multiobjective method shows a significant improvement in image quality and convergence behavior over the conventional algorithms     

关于解决黄牛鞋面革松面问题的探讨

本文讨论了在黄牛鞋面革生产过程中产生松面的原因，并经过多年的生产实践，摸索出解决松面问题行之有效的技术措施。     

Apoptosis in the early stage of compensatory renal growth following uninephrectomy in the young and old rats

Myostatin (GDF-8) is a member of the transforming growth factor-beta superfamily and plays a role in muscle growth and development. Mice having targeted disruption of this gene display marked increases in muscle mass, a phenotype similar to the muscular hypertrophy (mh) in several cattle breeds. Physical mapping data developed from YAC clones indicate the bovine myostatin gene lies close to the centromere of bovine Chromosome (Chr) 2 (BTA2) at 2q11, indistinguishable from the cytogenetic location of the mh locus. In addition, a polymorphism in the second intron of the gene was used to show that myostatin maps within the interval previously shown to contain mh. These data suggest myostatin may be the gene causing muscular hypertrophy in cattle.     

中原油田深井大井眼段钻井液工艺

濮深8井是中原油田在西部洼陷南部寻找接替储量的一口重点深探井,也是中原油田第一口井深达6000m的超深井。分析了濮深8井钻井液的配备及维护和处理技术,得出深井大井眼段钻井液工艺技术存在以下问题:井眼大,钻井液量及钻屑量多,处理时间长,处理剂用量多,处理频繁;返速低使钻井液清洗井眼的能力减弱;井下温度高使处理剂的作用明显降低,二氧化碳的侵入使钻井液性能变差。钻井液维护处理的较好方法是定时、定量补充处理剂胶液。固相控制是深井大井眼段钻井液工艺中的关键问题,必须配套并且有效地使用固控设备,以维护好钻井液性能。     

华北油田鄚东地区深井钻井液技术

鄚东地区钻井过程中经常发生垮塌、卡钻、井漏等复杂事故。该地区深井钻井采用了抑制性及封堵性较强的铵基沥青树脂高密度钻井液体系,并根据地层特点,对不同井段制定了相应的钻井液维护处理措施。结果表明,该钻井液体系抑制性好,抗温、抗污染能力强,性能稳定,成功地控制了复杂事故的发生,满足了该地区深层钻井的要求。     

四种别藻蓝蛋白三聚体的时间分辨荧光光谱研究

研究了从Ａｎａｂａｎａｖａｒｉｂｉｌｉｓ中提取的４种别藻蓝蛋白ＡＰＣＩ，ＡＰＣＩＩ，ＡＰＣＩＩ及ＡＰＣＢ三聚体的稳态光谱和皮秒荧光光谱。采用Ｍｏｎｔｅ－Ｃａｒｌｏ方法对瞬态荧光光谱进行拟合，实验结果表明：ＡＰＣＩ荧光有两个带，其中第一个带位于６６２ｎｍ，有两个时间组分：３５．８ｐｓ和１．６７ｎｓ；第二个带位于６８０ｎｍ，有两个时间组分：３４．２ｐｓ和１．６４ｎｓ；ＡＰＣＩＩ瞬态荧光位于６６０ｎｍ，有两个时间组分：２０．４ｐｓ和１．６４ｎｓ；ＡＰＣＩＩ瞬态荧光位于６６０ｎｍ，有两个时间组分：２３．８ｐｓ和１．７６ｎｓ；ＡＰＣＢ瞬态荧光有两个带，其中第一个带位于６６２ｎｍ，有两个时间组分：３６．６ｐｓ和１．４５ｎｓ；第二个带位于６８０ｎｍ，有两个时间组分：２５．８ｐｓ和１．６２ｎｓ。实验结果一方面说明了藻胆体核内４种别藻蓝蛋白形成能量传递的两条途径；另一方面瞬态荧光解叠结果揭示了ＡＰＣＩ和ＡＰＣＢ三聚体内能量传递的超快过程。     

判断油气藏非均质性的新方法

非均质性是油气藏的基本特性,也是影响油气面采收率的重要因素.它是反映油气藏的渗透率、孔隙度、有效厚度及其连通性的综合特征参数.不同油气藏在投入开发后,其产量随时间变化的分布曲线与油气藏自身的非质均性有密切关系.利用伽马分布描述油气藏产量随时间的变化,研制了典型曲线的理论图版,通过拟会求解,可判断油气藏的非均质程度.