Pharmacokinetic and pharmacodynamic effects of vaginal rings releasing levonorgestrel at a rate of 27 micrograms/24 hours: a pilot study

The pharmacokinetic and pharmacodynamic effects of vaginal rings releasing levonorgestrel (L-NOG) at an initial rate of 27 micrograms/24 h were studied in a group of 12 normally menstruating women during 90 days of continuous use (i.e., during three 30-day treatment segments). Blood samples were drawn immediately before insertion, 15 and 30 min, as well as 1, 2, 4, 8, 12 and 24 h after insertion of the rings, and thereafter three times weekly throughout the study for the analysis of L-NOG, estradiol, progesterone and sex hormone-binding globulin (SHBG). Endometrial biopsies were obtained for a morphometric analysis in a pre-treatment (control) cycle and in the 6th and 10th weeks of treatment. The peak of average L-NOG levels was reached within two hours after the insertion of rings. Until 24 h after insertion, the levels did not change significantly. Thereafter, a decrease at a rate of 0.2% per day was initiated. The L-NOG and SHBG levels were highly correlated. This was seen for both the pre-treatment SHBG vs L-NOG (r = 0.96) and the treatment SHBG vs L-NOG levels (r = 0.92). There was a significant (p < 0.001) decrease of SHBG levels due to treatment. During the total of 36 treatment segments, a normal ovarian function was seen in 47% of the segments. The women were anovulatory and had an inadequate lutal function in 28% and 25% of segments, respectively. No correlation between the L-NOG levels and ovarian reaction to treatment was found. The use of L-NOG induced significant changes in the endometrium; the number of glands/mm2 decreased after 6 (p < 0.02) and 10 weeks of use (p < 0.01). Also, the diameter of glands and the occurrence of vacuolated cells decreased significantly (p < 0.02 and p < 0.005, respectively). None of the endometrial parameters or dating was correlated with the ovarian reaction to treatment, indicating independent endometrial effects of L-NOG.     

压力对Fe－29wt％Ni合金超细微粒特性的影响

利用蒸发冷凝法，制备了不同平均粒径的Ｆｅ－２９ｗｔ％Ｎｉ合金超细微粒。在不同压强下，将超细微粒压制成片。随压强增大，马氏体体积分数和比饱和磁化强度σｓ明显增大，而矫顽力Ｈｃ呈线性下降。压力效应与平均粒径ｄ大小密切相关     

Water‐soluble/dispersible cationic pressure‐sensitive adhesives. I. Adhesives from solution polymerization

Pressure‐sensitive adhesives (PSAs) have long been a problem as sticky contaminants for paper recycling mills. The main problem associated with such stickies is that the PSAs in the waste papers deposit on the felts, press rolls, and drying cylinders of paper machines, and this creates problems with paper formation, reducing the paper quality and paper machine runnability. The annual cost of stickies to the U.S. paper industry is estimated to be about $600,000,000–650,000,000. To solve this problem, a series of cationic water‐soluble/dispersible PSAs have been synthesized by the free‐radical solution polymerization of butyl acrylate and [3‐(methacryloylamino)propyl]trimethylammonium chloride in ethanol. The PSA end‐use properties, repulpability in paper recycling, and the effects on the properties of recycled paper products have been studied. The cationic PSAs can be dissolved or dispersed in water if the cationic charge density in the PSA backbone is controlled, and so they do not deposit as stickies during recycling and papermaking processes. Because the PSAs are cationically charged, they can easily be removed from the papermaking system by adsorption onto the negatively charged fibers and fine surfaces. Furthermore, the adsorbed colloidal or dissolved PSAs have little effect on the final paper properties. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1624–1630, 2003     

横波速度各向异性初步探讨：—多波勘探资料的应用

在纵波、SH 型横波资料处理和解释过程中,我们发现四川 HBC 地区地下介质普遍存在方向各向异性。当横波通过方向各向异性介质时,分裂成两个波:一个波的偏振方向与裂缝平行,叫快横波;另一个波的偏振方向与裂缝走向垂直,叫慢横波。采用相应的观测和处理方法,便可获得快横波和慢横波剖面。根据同一界面的快、慢横波的旅行时可以求得各向异性系数。同样,还可以利用 SH 波与转换波的速度比求取各向异性系数。各向异性系数的大小,反映了裂缝的发育程度。如果野外作了 X、Y 分量观测,室内又作了坐标旋转处理,那么,就可以进一步确定裂缝带的方向。如果未作上述工作,也可以根据构造线走向,大致确定裂缝带的发育方向。     

Thermal Shock Behavior of Porous Silicon Carbide Ceramics

Using the water-quenching technique, the thermal shock behavior of porous silicon carbide (SiC) ceramics was evaluated as a function of quenching temperature, quenching cycles, and specimen thickness. It is shown that the residual strength of the quenched specimens decreases gradually with increases in the quenching temperature and specimen thickness. Moreover, it was found that the fracture strength of the quenched specimens was not affected by the increase of quenching cycles. This suggests a potential advantage of porous SiC ceramics for cyclic thermal-shock applications.     

2.5-dimensional VLSI system integration

The excessive interconnection delay and fast increasing development cost, as well as complexity of the single-chip integration of different technologies, are likely to become the major stumbling blocks for the success of monolithic system-on-chips. To address the above problems, this paper investigates a new VLSI integration paradigm, the so-called 2.5-dimensional (2.5-D) integration scheme. Using this scheme, a VLSI system is implemented as a three-dimensional stacking of monolithic chips. A cost analysis framework was developed to justify the 2.5-D integration scheme from an economic point of view. Enabling technologies for the new integration scheme are also reviewed.     

SIS热塑性嵌段共聚物的生产方法及应用

概述了SIS热塑性弹性体的合成方法以及国内外SIS生产和应用情况。综述了SIS在胶黏剂应用上的特点以及以茂金属为催化剂的SIS新低压加氢工艺的进展和国内SIS发展现状，提出了大力开发C5资源促进我国SIS产业发展的建议。     

PetaStar: a petabit photonic packet switch

This paper presents a new petabit photonic packet switch architecture, called PetaStar. Using a new multidimensional photonic multiplexing scheme that includes space, time, wavelength, and subcarrier domains, PetaStar is based on a three-stage Clos-network photonic switch fabric to provide scalable large-dimension switch interconnections with nanosecond reconfiguration speed. Packet buffering is implemented electronically at the input and output port controllers, allowing the central photonic switch fabric to transport high-speed optical signals without electrical-to-optical conversion. Optical time-division multiplexing technology further scales port speed beyond electronic speed up to 160 Gb/s to minimize the fiber connections. To solve output port contention and internal blocking in the three-stage Clos-network switch, we present a new matching scheme, called c-MAC, a concurrent matching algorithm for Clos-network switches. It is highly distributed such that the input-output matching and routing-path finding are concurrently performed by scheduling modules. One feasible architecture for the c-MAC scheme, where a crosspoint switch is used to provide the interconnections between the arbitration modules, is also proposed. With the c-MAC scheme, and an internal speedup of 1.5, PetaStar with a switch size of 6400 /spl times/ 6400 and total capacity of 1.024 petabit/s can be achieved at a throughput close to 100% under various traffic conditions.     

悬浮床加氢裂化油溶性催化剂与沥青质的作用

在高压釜反应器中对添加了油溶性 Ni 催化剂(UPC-O)和水溶性 Ni 催化剂(UPC-W)的辽河稠油常压渣油(LHAR)进行了悬浮床加氢裂化实验。通过元素分析和傅里叶变换红外光谱(FTIR)分析对抑制反应生焦效果好的 UPC-O 与 LHAR 沥青质的作用进行了研究。元素分析结果显示,在 LHAR 中加入 UPC-O1000μg/g,沥青质和脱沥青质油中 Ni 含量分别出476μg/g和110μg/g 增加到7 559μg/g 和1 024μg/g,表明 UPC-O 在沥青质中有富集的趋势。FTIR 表征结果显示,UPC-O 和沥青质发生了相互作用。UPC-O 可在沥青质原位硫化为活性组分,对沥青质在悬浮床加氢裂化反应中的缩合起到好的抑制作用。     

降低汽油烯烃含量裂化催化剂LBO-12的研制与开发

探讨了催化裂化过程降低汽油烯烃的反应原理，研究了催化剂各组分对裂化汽油性质影响的规律性，围绕提高氢转移活性，提出制备降烯烃裂化催化剂的技术路线，并研制开发了新型LBO-12降烯烃催化剂，固定流化床反应器对中试样品的评价和工业应用结果表明，该催化剂在不损失汽油辛烷值的前提下，降低催化裂化汽油烯烃能力较强，并具有较高的水热活性稳定性和良好的抗重金属污染特性。