全文获取类型
收费全文 | 171篇 |
免费 | 6篇 |
专业分类
177篇 |
出版年
2021年 | 1篇 |
2019年 | 1篇 |
2018年 | 1篇 |
2017年 | 1篇 |
2016年 | 2篇 |
2015年 | 4篇 |
2014年 | 6篇 |
2013年 | 10篇 |
2012年 | 10篇 |
2011年 | 7篇 |
2010年 | 3篇 |
2009年 | 2篇 |
2008年 | 5篇 |
2007年 | 11篇 |
2006年 | 11篇 |
2005年 | 12篇 |
2004年 | 6篇 |
2003年 | 7篇 |
2002年 | 7篇 |
2001年 | 1篇 |
2000年 | 5篇 |
1999年 | 2篇 |
1998年 | 4篇 |
1997年 | 6篇 |
1996年 | 3篇 |
1995年 | 1篇 |
1994年 | 7篇 |
1993年 | 3篇 |
1992年 | 8篇 |
1991年 | 5篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 3篇 |
1979年 | 3篇 |
1978年 | 2篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1970年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有177条查询结果,搜索用时 0 毫秒
71.
Nakatsuka S Yashiro H Inoue M Kuribayashi S Kawamura M Izumi Y Tsukada N Yamauchi Y Hashimoto K Iwata K Nagasawa T Lin YS 《Cryobiology》2010,61(3):317-326
Regarding cryoablation for the malignant lung tumors, multiple trials of the freeze-thaw process have been made, and we considered it necessary to view and analyze the freeze-thaw process as a freeze-thaw sequence. We caused the sequence in a porcine lung in vivo by using an acicular, cylindrical stainless-steel probe as the heat source for the freeze-thaw sequence and cooling to -150 °C with super high-pressure argon gas by causing the Joule-Thomson effect phenomenon at the tip of the probe. In this experiment, we examined the sequence by measuring the temperature and using the isothermal curve and the freezing function. As a result, it was demonstrated that the freezing characteristics considerably differed in the first sequence and the second sequence from those of non-aerated organs such as liver and kidney. In our experiments on porcine lung, thermal properties were considered to change as the bleeding caused by the first thawing infiltrated in the lung parenchyma, and it was confirmed that the frozen area in the second cycle was dramatically enlarged as compared with the first cycle (when a similar sequence is continuously repeated, we say it as cycle). This paper provides these details. 相似文献
72.
Sachio Kudo Takayuki Oritani Kyohei Yamashita 《Bioscience, biotechnology, and biochemistry》2013,77(9):2315-2319
Optically active tiraras-cycloheximide isomers such as cycloheximide [(2S,4S,6R,αR)-form (1)], naramycin B[(25,4S,6RαR)-form(4)], and new stereoisomers (2S,4S,6S,αS)-form (8) and (2S,4S,6R,αS)-from (9) were synthesized by an aldol condensation of trans-2,4-dimethyl-l-cyclohexanone (5b), with 4-(2-oxoethyl)-2,6-piperidinedione(6). The antimicrobial activity of trans- cycloheximide isomers (1, 4, 8, and 9) was examined against S. cerevisiae and P. oryzae. The stereoisomers 1 and 4 exhibited marked antimicrobial activity against both microorganisms as compared with their C- α-epimers 8 and 9. 相似文献
73.
Mitsuhiro?NakayaEmail author Taizo?Morioka Kyohei?Fukunaga Naoto?Murakami Takashi?Ichikawa Sachio?Sekiya Satoshi?Suyama Yasuhiro?Ueno Akio?Shimizu 《Environmental Biology of Fishes》2011,92(1):113-123
To understand the survival processes in Pacific saury during the early life stages, growth histories were compared between
individuals that died and those that survived under laboratory conditions. The morphology of Pacific saury drastically changed
by 40 day after hatching (DAH) under 20°C, and during this period most individuals reached the juvenile stage (40 mm knob
length (KnL)). From hatch to this period, high levels of mortality were observed. The back-calculated growth rates analyzed
from otolith microstructure were compared among individuals that died and those that survived this period of metamorphosis.
Growth rates of individuals that died were significantly lower since 1 DAH than surviving individuals. Factors contributing
to mortality are considered to be the cumulative effects of their delayed growth and their less favorable body conditions
(growth dependent survival). The body size (40 mm KnL) that is currently used to estimate the recruitment is concluded to
be valid for evaluating the recruitment in the field. 相似文献
74.
Saito H Tabata K Hanada S Kanda Y Suzuki T Miyairi S 《Bioorganic & medicinal chemistry letters》2011,21(18):5370-5373
This paper reports the synthesis of methoxy- and bromo-indirubins, and their antiproliferative activities in human neuroblastoma. Among 20 compounds, 5'-methoxyindirubin induced cell death in human neuroblastoma cells (IMR-32, SK-N-SH and NB-39) without inhibiting normal cells (NHDF and HUVEC). Typical morphologic features of apoptosis were observed in 5'-methoxyindirubin-treated cells by Hoechst 33342 staining. Additional studies by flow cytometry support apoptosis induction. These data suggest that 5'-methoxyindirubin might be an effective drug for treatment of neuroblastoma. 相似文献
75.
Miwa S Nakamura M Okuno M Miyazaki H Watanabe J Ishikawa-Takano Y Miura M Takase N Hayakawa S Kobayashi S 《Bioscience, biotechnology, and biochemistry》2011,75(9):1649-1653
A starch ingredient with antioxidative activity, as measured by the DPPH method, was produced by baking corn starch with an organic acid; it has been named ANOX sugar (antioxidative sugar). The baking temperature and time were fixed at 170 °C and 60 min, and the organic acid used was selected from preliminary trials of various kinds of acid. The phytic acid ANOX sugar preparation showed the highest antioxidative activity, but the color of the preparation was almost black; we therefore selected L-tartaric acid which had the second highest antioxidative activity. The antioxidative activity of the L-tartaric acid ANOX sugar preparation was stable against temperature, light, and enzyme treatments (α-amylase and glucoamylase). However, the activity was not stable against variations in water content and pH value. The antioxidative activity of ANOX sugar was stabilized by treating with boiled water or nitrogen gas, or by pH adjustment. 相似文献
76.
Chitinase,β-1,3-glucanase, cellulase, xylanase and protease activity were detected in a crude enzyme preparation obtained from a slime
mold (Badhamia utricularis) which was grown on autoclaved mycelia ofPholiota nameko in a petri dish. The optimal pH of the enzyme preparation for lytic activity against fruit bodies ofLentinus edodes was 4.0, and those ofβ-1,3-glucanase and cellulase were the same. On the other hand, chitinase and protease showed optimal activity at pH 5.0 and
8.0, respectively. The lytic activity was stable below 40°C but completely inactivated at 70°C, and was most stable at pH
5.0. The studies of the optimal pH, thermal stability, and pH stability, and isoelectric focusing analysis of the enzyme preparation
suggest that chitinase,β-1,3-glucanase and cellulase activities may be responsible for lysis of fruit bodies of some mushrooms. The crude enzyme preparation
from the slime mold lysed fruit bodies of several mushrooms more efficiently than did commercial lytic enzymes preparations
(Driselase and Usukizyme). 相似文献
77.
Yuhko Suzuki Takao Kitahara Kazui Soma Shingo Konno Kimitoshi Sato Sachio Suzuki Hidehiro Oka Masaru Yamada Kiyotaka Fujii Yukio Kitahara Yuji Yamamoto Takashi Otsuka Yoshihiro Sugiura Yuhsaku Kanoh Yoshiko Tamai Hitoshi Ohto 《PloS one》2014,9(5)
This study examined the impact of platelet transfusion (PLT) on the survival of intracerebral hemorrhage (ICH) patients who had been administered anti-platelet agents (APA). This retrospective cohort analysis investigated 432 patients (259 men, 60%) who were newly diagnosed with ICH between January 2006 and June 2011 at the tertiary emergency center of Kitasato University Hospital. Median age on arrival was 67.0 years (range, 40–95 years). ICH was subcortical in 72 patients (16.7%), supratentorial in 233 (53.9%), and infratentorial in 133 (30.8%). PLT was performed in 16 patients (3.7%). Within 90 days after admission to the center, 178 patients (41.2%) had died due to ICH. Before the onset of ICH, 66 patients had been prescribed APA because of atherosclerotic diseases. Multivariate regression analysis indicated APA administration was an independent risk factor for death within 7 days (odds ratio, 5.12; P = 0.006) and within 90 days (hazard ratio, 1.87; P = 0.006) after arrival. Regarding the effect of a PLT in ICH patients with APA, no patient with PLT died. PLT had a survival benefit on patients with ICH, according to our analysis. Further prospective analysis is necessary to confirm the effects of PLT on survival in ICH with APA. 相似文献
78.
Suzuki T Shioya T Murayama T Sugihara M Odagiri F Nakazato Y Nishizawa H Chugun A Sakurai T Daida H Morimoto S Kurebayashi N 《PloS one》2012,7(4):e35353
Background
Patients with inherited dilated cardiomyopathy (DCM) frequently die with severe heart failure (HF) or die suddenly with arrhythmias, although these symptoms are not always observed at birth. It remains unclear how and when HF and arrhythmogenic changes develop in these DCM mutation carriers. In order to address this issue, properties of the myocardium and underlying gene expressions were studied using a knock-in mouse model of human inherited DCM caused by a deletion mutation ΔK210 in cardiac troponinT.Methodology/Principal Findings
By 1 month, DCM mice had already enlarged hearts, but showed no symptoms of HF and a much lower mortality than at 2 months or later. At around 2 months, some would die suddenly with no clear symptoms of HF, whereas at 3 months, many of the survivors showed evident symptoms of HF. In isolated left ventricular myocardium (LV) from 2 month-mice, spontaneous activity frequently occurred and action potential duration (APD) was prolonged. Transient outward (Ito) and ultrarapid delayed rectifier K+ (IKur) currents were significantly reduced in DCM myocytes. Correspondingly, down-regulation of Kv4.2, Kv1.5 and KChIP2 was evident in mRNA and protein levels. In LVs at 3-months, more frequent spontaneous activity, greater prolongation of APD and further down-regulation in above K+ channels were observed. At 1 month, in contrast, infrequent spontaneous activity and down-regulation of Kv4.2, but not Kv1.5 or KChIP2, were observed.Conclusions/Significance
Our results suggest that at least three steps of electrical remodeling occur in the hearts of DCM model mice, and that the combined down-regulation of Kv4.2, Kv1.5 and KChIP2 prior to the onset of HF may play an important role in the premature sudden death in this DCM model. DCM mice at 1 month or before, on the contrary, are associated with low risk of death in spite of inborn disorder and enlarged heart. 相似文献79.
T Ohashi Y Oguro T Tanaka Z Shiokawa S Shibata Y Sato H Yamakawa H Hattori Y Yamamoto S Kondo M Miyamoto H Tojo A Baba S Sasaki 《Bioorganic & medicinal chemistry》2012,20(18):5496-5506
The Hedgehog (Hh) signaling pathway plays a significant role in the regulation of cell growth and differentiation during embryonic development. Since activation of the Hh signaling pathway is implicated in several types of human cancers, inhibitors of this pathway could be promising anticancer agents. Using high throughput screening, thieno[3,2-c]quinoline-4-one derivative 9a was identified as a compound of interest with potent in vitro activity but poor metabolic stability. Our efforts focused on enhancement of in vitro inhibitory activity and metabolic stability, including core ring conversion and side chain optimization. This led to the discovery of pyrrolo[3,2-c]quinoline-4-one derivative 12b, which has a structure distinct from previously reported Hh signaling inhibitors. Compound 12b suppressed stromal Gli1 mRNA expression in a murine model and demonstrated antitumor activity in a murine medulloblastoma allograft model. 相似文献
80.
S Miyairi O Sugita S Sassa J Fishman 《Biochemical and biophysical research communications》1988,150(1):311-315
The oxidative metabolism of androgens in the rat brain includes aromatization preceded by the requisite 19-hydroxylation. We have examined the transformation of [19-C3H3]androstenedione and [4-14C]testosterone by the semipurified cytochrome P-450 fraction of the rat brain. [19-C3H3]Androstenedione generated tritiated water and formic acid in a ratio of 8 to 1 indicating that 19-hydroxylation in the brain far exceeds that necessary for aromatization. This was confirmed by the results of the 14C-testosterone incubation in which the 14C labeled 19-hydroxy and 19-oxo derivatives which were isolated exceeded the yield of 14C-estrogens by several fold. Thus the rat brain has the capacity to form in situ 19-hydroxylated androgens which are not available to it from the circulation. 相似文献