首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   90篇
  免费   3篇
电工技术   4篇
化学工业   33篇
建筑科学   7篇
能源动力   4篇
轻工业   5篇
无线电   5篇
一般工业技术   1篇
冶金工业   26篇
原子能技术   1篇
自动化技术   7篇
  2023年   1篇
  2021年   1篇
  2019年   1篇
  2018年   5篇
  2017年   2篇
  2016年   2篇
  2015年   1篇
  2014年   1篇
  2011年   3篇
  2009年   3篇
  2008年   4篇
  2006年   3篇
  2005年   1篇
  2004年   3篇
  2002年   2篇
  1999年   1篇
  1998年   15篇
  1997年   10篇
  1996年   3篇
  1995年   2篇
  1994年   2篇
  1993年   1篇
  1990年   1篇
  1989年   1篇
  1988年   1篇
  1986年   4篇
  1985年   1篇
  1984年   1篇
  1983年   2篇
  1982年   1篇
  1980年   1篇
  1979年   2篇
  1978年   1篇
  1977年   1篇
  1976年   3篇
  1975年   1篇
  1974年   1篇
  1973年   4篇
排序方式: 共有93条查询结果,搜索用时 0 毫秒
41.
Wilson's disease, an autosomal recessive disorder, is characterized by the excessive accumulation of copper in the liver. WND (ATP7B) gene, which encodes a putative copper transporting P-type ATPase, is defective in the patients. To investigate the in vivo function of WND protein as well as its intracellular localization, WND cDNA was introduced to the Long-Evans Cinnamon rat, known as a rodent model for Wilson's disease, by recombinant adenovirus-mediated gene delivery. An immunofluorescent study and a subcellular fractionation study revealed the transgene expression in liver and its localization to the Golgi apparatus. Moreover, since the synthesis of holoceruloplasmin is disturbed in the Long-Evans Cinnamon rat, the plasma level of holoceruloplasmin, oxidase-active and copper-bound form, was examined to evaluate the function of WND protein with respect to the copper transport. Consequently, the appearance of holoceruloplasmin in plasma was confirmed by Western blot analysis and plasma measurements for the oxidase activity and the copper content. These findings indicate that introduced WND protein may function in the copper transport coupled with the synthesis of ceruloplasmin and that the Golgi apparatus is the likely site for WND protein to manifest its function.  相似文献   
42.
We report herein the case of a 77-year-old man with a left ventricular tumor originating from the papillary muscle of the left ventricular wall, in whom a successful tumor resection with mitral valve replacement was performed. The pathological diagnosis of the tumor was confirmed as cardiac fibroma. His postoperative course was uneventful and he is currently well with no signs of recurrence 2 years after surgery.  相似文献   
43.
44.
We describe the case of a 44-year-old woman with a delayed hemolytic transfusion reaction (DHTR). She had a history of two pregnancies and a blood transfusion, the details of which were unknown. At the time of her first vascular surgery on November 15, 1989, she received 1200 ml of crossmatch-compatible concentrated red blood cells (CRC). Before the first operation, screening for anti-RBC antibodies (Ab) was negative. At the time of the second admission on Feburary 15, 1996, anti-E Abs were detected by indirect antiglobulin test. She received 560 ml of E-antigen-negative, crossmatch-compatible, CRC for treatment of anemia on March 1 and 2, 1996. After this transfusion, total bilirubin (1.6 mg/dl) and lactate dehydrogenase (1355 IU/ml) were elevated on March 12, 1996. She had no evidence of clinical hemolysis. We suspected DHTR from these data, and therefore screened for anti-RBC Abs. Anti-E, Jka, Dia, Fyb, and S Abs were detected in blood samples obtained from the patient on March 12, 1996. Anti-E, Jka Dia, and S Abs were present more than 1 month and anti-Fyb Ab was disappeared at 18 days after transfusion.  相似文献   
45.
46.
A characteristic feature of the reactivity of indolequinone derivatives, substituents of which can be removed by one-electron reduction under hypoxic conditions, was applied to the development of a new class of fluorescent probes for disease-relevant hypoxia. A reducing indolequinone parent molecule conjugated with fluorescent coumarin chromophores could suppress efficiently the fluorescence emission of the coumarin moieties by an intramolecular electron-transfer quenching mechanism and a conventional internal-filter effect. Under hypoxic conditions, however, the conjugate, denoted IQ-Cou, underwent a one-electron reduction triggered by X irradiation or the action of a reduction enzyme to release a fluorescent coumarin chromophore, whereupon an intense fluorescence emission with a maximum intensity at 420 nm was observed. The one-electron reduction of IQ-Cou was suppressed by molecular oxygen under aerobic conditions. IQ-Cou also showed intense fluorescence in a hypoxia-selective manner upon incubation with a cell lysate of the human fibrosarcoma cell line HT-1080. The IQ-Cou conjugate has several unique properties that are favorable for a fluorescent probe of hypoxia-specific imaging.  相似文献   
47.
48.
The permeability of a composite membrane consisting of a homogeneous layer and a porous layer has been derived theoretically by assuming that the permeation through the homogeneous layer obeys Fick's law and that permeation through the porous layer is free molecular flow. The activation energy of the flow is described by three-dimensionless parameters, ? = |P12/|P2, θ = d1/d2, and σ = |P1/|P2. |P12, |P1, and |P2 are the permeability coefficients of the composite membrane, the homogeneous layer and the porous layer, respectively, d1 and d2 are the thickness of the two layers. Once these parameters are determined, information on the structure of the membrane can be obtained (i.e., the pore size and the pore density). The permeabilities of various gases through homogeneous polycarbonate membrane, neutron-irradiated, nonsodium hydroxide-etched polycarbonate membrane, and their composite membrane were tested. A two-layer series model, incorporating the effect of neutron irradiation which produces some nonpenetrating pores in the porous membrane layer, is proposed and agreed quite well with the experimental data.  相似文献   
49.
Poly(ethylene terephthalate), PET reacted with various glycols in the presence of titanium tetraisopropoxide as a catalyst. The glycolyzed PET was fractionated into two parts—soluble and insoluble in CHCl3—characterized and used as a raw material to synthesize copolyesters. The soluble part in the CHCl3 part was a mixture of monomers and oligomers, and no melting points were observed. On the other hand, in the insoluble part a melting point was determined. The glycolyzed PET and copoly(succinic anhydride/ethylene oxide), PES were condensed to produce copolymers. The synthesized copolyesters were amorphous and hydrolyzed enzymatically due to a decrease in the crystallinity. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1838–1847, 2002; DOI 10.1002/app.10462  相似文献   
50.
Peptide nucleic acid (PNA) can form a stable duplex with DNA, and, accordingly, directly recognize double‐stranded DNA through the formation of a double‐duplex invasion complex, wherein a pair of complementary PNA strands form two PNA/DNA duplexes. Because invasion does not require prior denaturation of DNA, PNA holds great potential for in cellulo or in vivo applications. To broaden the applicability of PNA invasion, we developed a new conjugate of PNA with a ruthenium complex. This Ru–PNA conjugate exhibits higher DNA‐binding affinity, which results in enhanced invasion efficiency, even under physiological conditions.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号