全文获取类型
收费全文 | 3009篇 |
免费 | 165篇 |
出版年
2022年 | 15篇 |
2021年 | 32篇 |
2020年 | 22篇 |
2019年 | 33篇 |
2018年 | 43篇 |
2017年 | 42篇 |
2016年 | 42篇 |
2015年 | 71篇 |
2014年 | 103篇 |
2013年 | 136篇 |
2012年 | 172篇 |
2011年 | 158篇 |
2010年 | 100篇 |
2009年 | 92篇 |
2008年 | 154篇 |
2007年 | 135篇 |
2006年 | 139篇 |
2005年 | 141篇 |
2004年 | 133篇 |
2003年 | 135篇 |
2002年 | 132篇 |
2001年 | 123篇 |
2000年 | 124篇 |
1999年 | 100篇 |
1998年 | 38篇 |
1997年 | 24篇 |
1996年 | 18篇 |
1995年 | 20篇 |
1994年 | 19篇 |
1993年 | 24篇 |
1992年 | 79篇 |
1991年 | 60篇 |
1990年 | 39篇 |
1989年 | 52篇 |
1988年 | 49篇 |
1987年 | 47篇 |
1986年 | 33篇 |
1985年 | 39篇 |
1984年 | 27篇 |
1983年 | 27篇 |
1982年 | 25篇 |
1981年 | 17篇 |
1980年 | 15篇 |
1979年 | 25篇 |
1978年 | 13篇 |
1977年 | 13篇 |
1976年 | 10篇 |
1974年 | 10篇 |
1970年 | 9篇 |
1969年 | 14篇 |
排序方式: 共有3174条查询结果,搜索用时 31 毫秒
121.
Koshi Nakamura Masaru Sakurai Katsuyuki Miura Yuko Morikawa Shin-ya Nagasawa Masao Ishizaki Teruhiko Kido Yuchi Naruse Yasushi Suwazono Hideaki Nakagawa 《PloS one》2013,8(1)
Given the lack of economic studies evaluating the outcomes of smoking cessation programs from the viewpoint of program sponsors, we conducted a case study to provide relevant information for worksites. The present study was carried out between 2006 and 2008 at a manufacturing factory in the Toyama Prefecture of Japan and included subjects who voluntarily entered a smoking cessation program. The program included face-to-face counselling followed by weekly contact to provide encouragement over six months using e-mail or inter-office mail. Nicotine patches were available if required. All 151 participants stopped smoking immediately. Over the 24-month study period, self-report showed 49.7% abstained continuously from smoking. The rate of 24-month consecutive abstinence was higher in participants with lower Fagerström Test scores for Nicotine Dependence at baseline than in those with higher scores (63.6% for 0–2 points vs. 46.5% for 3–6 points vs. 43.8% for 7–10 points; chi-square test p = 0.19). A logistic regression model showed a significant linear trend for the association between the score and abstinence status after adjustment for possible confounding factors (p = 0.03). The crude incremental cost for one individual to successfully quit smoking due to the support program was ¥46,379 (i.e., ¥100 = $1.28, £0.83, or €1.03 at foreign exchange rates). The corresponding costs for the three categories of the Fagerström Test score for Nicotine Dependence were ¥31,953, ¥47,450 and ¥64,956, respectively. When a sensitivity analysis was conducted based on the 95% confidence interval of the success rate, the variance in the corresponding costs was ¥25,514–45,034 for 0–2 points, ¥38,344–61,824 for 3–6 points, and ¥45,698–108,260 for 7–10 points. The degree of nicotine dependence may therefore be an important determinant of the cost-effectiveness of smoking cessation programs. 相似文献
122.
Ken Fukami Kiyoshi Kawai Sayaka Takeuchi Yoshito Harada Yoshio Hagura 《Food biophysics》2016,11(4):410-416
To understand the fundamental physical properties of calcium maltobionate (MBCa), its water sorption isotherm, glass transition temperature (T g), and viscosity (η) were investigated and compared with those of maltobionic acid (MBH) and maltose. Although amorphous maltose crystalized at water activity (a w) higher than 0.43, MBCa and MBH maintained an amorphous state over the whole a w range. In addition, MBCa had a higher T g and greater resistance to water plasticizing than MBH and maltose. These properties of MBCa likely originate from the strong interaction between MBCa and water induced by electrostatic interactions. Moreover, the effects of temperature and water content on η of an aqueous MBCa solution were evaluated, and its behavior was described using a semi-empirical approach based on a combination of T g extrapolated by the Gordon-Taylor equation and a non-Arrhenius formula known as the Vogel–Fulcher–Tammann equation. This result will be useful for understating the effect of MBCa addition on the solution’s properties. 相似文献
123.
124.
Sayaka Nakashima Zhe Liu Yuya Yamaguchi Shunya Saiki Shintaro Munemasa Toshiyuki Nakamura Yoshiyuki Murata Yoshimasa Nakamura 《Biochemistry and Biophysics Reports》2016
3,4-Dihydroxyphenylacetic acid (DOPAC) is one of the colonic microflora-produced catabolites of quercetin 4′-glucoside (Q4′G). Although the interaction of DOPAC with cellular proteins might be involved in its biological activity, the actual proteins have not yet been identified. In this study, we developed a novel tag-free DOPAC probe to label the targeted proteins by the copper(I)-catalyzed azide alkyne cycloaddition (CuAAC) and verified its efficacy. Various labeled proteins were detected by the DOPAC probe with the azide labeled biotin and a horseradish peroxidase (HRP)-streptavidin complex. Furthermore, a pulldown assay identified Keap1 and aryl hydrocarbon receptor (AhR) as the target proteins for the phase 2 enzyme up-regulation. 相似文献
125.
126.
Koki Kuramochi Kohsuke Uchimura Atsushi Kurata Tohru Kobayashi Yuu Hirose Takeshi Miura Noriaki Kishimoto Ron Usami Koki Horikoshi 《Extremophiles : life under extreme conditions》2016,20(4):471-478
An endo β-1,4-xylanase (XynE15) from a culture broth of a deep subseafloor microorganism, Microcella alkaliphila JAM-AC0309, was purified to homogeneity. The molecular mass of XynE15 was approximately 150 kDa as judged by SDS-PAGE. The optimal pH and temperature for hydrolysis of xylan were pH 8 and 65 °C. The enzyme was stable to incubation for 30 min at up to 75 °C, and the half-life at 50 °C was 48 h. XynE15 hydrolyzed arabinoxylan, oat spelt xylan, and birchwood xylan well, but not avicel, carboxymethylcellulose, or arabinan. Xylooligosaccharides were hydrolyzed to mainly xylobiose from higher than xylotetraose. The genome sequencing analysis of strain JAM-AC03039 revealed that XynE15 was composed of 1,319 amino acids with one catalytic domain and three carbohydrate-binding domains belonging to glycoside hydrolase (GH) family 10 and carbohydrate-binding module (CBM) family 4, respectively. 相似文献
127.
Hirotake Abe Haruka Wada Muhammad Baghdadi Sayaka Nakanishi Yuu Usui Takahiro Tsuchikawa Toshiaki Shichinohe Satoshi Hirano Ken-ichiro Seino 《Human cell》2016,29(2):58-66
Cancer vaccines serve as a promising clinical immunotherapeutic strategy that help to trigger an effective and specific antitumor immune response compared to conventional therapies. However, poor immunogenicity of tumor cells remains a major obstacle for clinical application, and developing new methods to modify the immunogenicity of tumor cells may help to improve the clinical outcome of cancer vaccines. 4T1 mouse breast cancer cell line has been known as poorly immunogenic and highly metastatic cell line. Using this model, we identified a sub cell line of 4T1—designated as 4T1-Sapporo (4T1-S)—which shows immunogenic properties when used as a vaccine against the same line. In 4T1-S-vaccinated mice, subcutaneous injection of 4T1-S resulted in an antitumor inflammatory response represented by significant enlargement of draining lymph nodes, accompanied with increased frequencies of activated CD8 T cells and a subpopulation of myeloid cells. Additionally, 4T1-S vaccine was ineffective to induce tumor rejection in nude mice, which importantly indicate that 4T1-S vaccine rely on T cell response to induce tumor rejection. Further analysis to identify mechanisms that control tumor immunogenicity in this model may help to develop new methods for improving the efficacies of clinical cancer vaccines. 相似文献
128.
Yuichiro Maeda Toshio Hasegawa Etsuko Komiyama Yusuke Hirasawa Hitoshi Tsuchihashi Takasuke Ogawa Jonghun Kim Seiichiro Ando Akio Nagasaka Naoto Miura Shigaku Ikeda 《Journal of biophotonics》2019,12(4)
In finger vein authentication technology, near‐infrared rays penetrate the finger and are absorbed by the hemoglobin in blood. The veins appear as dark areas. The finger vein pattern images of patients with various diseases were acquired; a new evaluation method applying image processing technique (“E value”) was developed, and it was examined whether the patterns have any characteristics differentiating them from those of healthy volunteers. As a result, low E values appeared in systemic sclerosis, mixed connective tissue disease, Sjögren's syndrome, and polymyositis/dermatomyositis. No statistical reduction in E value was shown in patients with rheumatoid arthritis, pernio (without rheumatic diseases), arteriosclerosis obliterans, diabetes, hypertension, hypothyroidism and alopecia areata. This technology could be used for screening and evaluation of some diseases and their conditions with impaired peripheral venous circulation. E value may be useful as an indicator of venous circulation. 相似文献
129.
Fujitani N Shimizu H Matsubara T Ohta T Komata Y Miura N Sato T Nishimura S 《Carbohydrate research》2007,342(12-13):1895-1903
The ganglioside GM1-binding peptide, p3, with a sequence of VWRLLAPPFSNRLLP, displayed a clear structural alteration depending on the presence or absence of GM1 micelles. The three-dimensional structures of the p3 peptide in the free and GM1 bound states were analyzed using two-dimensional NMR spectroscopic experiments with distance-restrained simulated annealing calculations. The NMR experiments for the p3 peptide alone indicated that the peptide has two conformers derived from the exchange of cis and trans forms at Pro(7)-Pro(8). Further study with theoretical modeling revealed that the p3 peptide has a curb conformation without regular secondary structure. On the other hand, the NMR studies for the p3 peptide with the GM1 micelles elucidated a trans conformer and gave a structure stabilized by hydrophobic interactions of beta- and helical turns. Based on these structural investigations, tryptophan, a core residue of the hydrophobic cluster, might be an essential residue for the recognition of the GM1 saccharides. The dynamic transition of the p3 peptide may play an important role in the function of GM1 as a multiple receptor as in the traditional pathway of the infection by cholera toxin. 相似文献
130.
Curcumin glucosyltransferase (CaUGT2) isolated from cell cultures of Catharanthus roseus exhibits unique substrate specificity. To identify amino acids involved in substrate recognition and catalytic activity of CaUGT2, a combination of domain swapping and site-directed mutagenesis was carried out. Exchange of the PSPG-box of CaUGT2 with that of NtGT1b (a phenolic glucosyltransferase from tobacco) led to complete loss of enzyme activity in the resulting recombinant protein. However, replacement of Arg378 of the NtGT1b PSPG-box with cysteine, the corresponding amino acid in CaUGT2, restored the catalytic activity of the chimeric enzyme. Further site-directed mutagenesis revealed that the size of the amino acid side-chain in that particular site is critical to the catalytic activity of CaUGT2. 相似文献