全文获取类型
收费全文 | 588篇 |
免费 | 40篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 8篇 |
2020年 | 4篇 |
2019年 | 9篇 |
2018年 | 8篇 |
2017年 | 8篇 |
2016年 | 20篇 |
2015年 | 25篇 |
2014年 | 22篇 |
2013年 | 53篇 |
2012年 | 42篇 |
2011年 | 45篇 |
2010年 | 24篇 |
2009年 | 21篇 |
2008年 | 30篇 |
2007年 | 49篇 |
2006年 | 25篇 |
2005年 | 39篇 |
2004年 | 33篇 |
2003年 | 32篇 |
2002年 | 26篇 |
2001年 | 9篇 |
2000年 | 11篇 |
1999年 | 10篇 |
1998年 | 5篇 |
1997年 | 4篇 |
1996年 | 5篇 |
1995年 | 2篇 |
1994年 | 5篇 |
1993年 | 2篇 |
1992年 | 8篇 |
1991年 | 6篇 |
1990年 | 4篇 |
1989年 | 10篇 |
1988年 | 3篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 3篇 |
1982年 | 2篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1973年 | 1篇 |
1967年 | 1篇 |
1965年 | 1篇 |
排序方式: 共有628条查询结果,搜索用时 15 毫秒
51.
Removal and recovery of phosphorous from swine wastewater by demonstration crystallization reactor and struvite accumulation device 总被引:10,自引:0,他引:10
Suzuki K Tanaka Y Kuroda K Hanajima D Fukumoto Y Yasuda T Waki M 《Bioresource technology》2007,98(8):1573-1578
A demonstration crystallization reactor and struvite accumulation device for the removal and recovery of phosphorous was constructed and their performance was evaluated using actual swine wastewater for 3.5 years. The wastewater pH was increased by aeration, and the concentrations of total P and soluble PO(4)-P were reduced by a struvite crystallization reaction induced under a high pH condition. A 30% MgCl(2) addition was effective in enhancing the struvite crystallization reaction. The concentrations of suspended solids, total Zn and total Cu, were also decreased by the settling function of the reactor. On removing the efficiencies of these components, no noticeable seasonal fluctuation in performance was observed during the 3.5-year operation. In terms of maximum yield, 171g struvite was obtained from 1m(3) swine wastewater by the demonstration accumulation device for struvite recovery. The recovered struvite needed only air-drying before use since it was approximately 95% pure even without washing. 相似文献
52.
The syndecan family of heparan sulfate proteoglycans is expressed on the surface of all adherent cells. Syndecans interact with a wide variety of molecules, including growth factors, cytokines, proteinases, adhesion receptors and extracellular matrix components, through their heparan sulfate chains. Recent studies indicate that these interactions not only regulate key events in development and homeostasis, but also key mechanisms of the host inflammatory response. This review will focus on the molecular and cellular aspects of how syndecans modulate tissue injury and inflammation, and how syndecans affect the outcome of inflammatory diseases in vivo. 相似文献
53.
Establishment and characterization of a cisplatin-resistant cell line (IGSK-1) from a poorly differentiated gastric adenocarcinoma 总被引:1,自引:0,他引:1
Ohi S Takahashi N Ninomiya K Nakajima M Hashimoto H Tachibana T Yanaga K Ishikawa H 《Human cell》2007,20(1):15-22
We successfully established a spontaneously cisplatin-resistant tumor cell line (designated as IGSK-1) derived from original gastric carcinoma. The patient was a 75-year-old Japanese woman. The histopathological diagnosis was gastric poorly differentiated adenocarcinoma accompanied with metastatic foci in lymph nodes, pT3, N2 M0, stage IIIB. The IGSK-1 cells grew as adhesive and monolayered cultures on the bottom of dishes. The susceptibility of the IGSK-1 cells to anti-cancer drugs was examined using oxygen electrode apparatus (Daikin, Tsukuba, JPN), and the results suggested TXL was effective, and CDDP, CPT-11 and 5-FU were not effective. Gastrin and somatostatin secretions were confirmed by immunohistochemical staining and also radioimmunoassay. Immunohistochemistry and radioimmunoassay for serotonin suggested the IGSK-1 cells might incorporate serotonin from the growth media. Spontaneously cisplatin-resistant gastric carcinoma cell line secreted gastrin and somatostatin is very important material for chemotherapy. 相似文献
54.
Kazutaka Sawada Tomoya Sato Hiroshi Hamajima Lahiru Niroshan Jayakody Miyo Hirata Mikako Yamashiro Marie Tajima Susumu Mitsutake Koji Nagao Keisuke Tsuge Fumiyoshi Abe Kentaro Hanada Hiroshi Kitagaki 《Applied and environmental microbiology》2015,81(11):3688-3698
In nature, different microorganisms create communities through their physiochemical and metabolic interactions. Many fermenting microbes, such as yeasts, lactic acid bacteria, and acetic acid bacteria, secrete acidic substances and grow faster at acidic pH values. However, on the surface of cereals, the pH is neutral to alkaline. Therefore, in order to grow on cereals, microbes must adapt to the alkaline environment at the initial stage of colonization; such adaptations are also crucial for industrial fermentation. Here, we show that the yeast Saccharomyces cerevisiae, which is incapable of synthesizing glucosylceramide (GlcCer), adapted to alkaline conditions after exposure to GlcCer from koji cereal cultured with Aspergillus kawachii. We also show that various species of GlcCer derived from different plants and fungi similarly conferred alkali tolerance to yeast. Although exogenous ceramide also enhanced the alkali tolerance of yeast, no discernible degradation of GlcCer to ceramide was observed in the yeast culture, suggesting that exogenous GlcCer itself exerted the activity. Exogenous GlcCer also increased ethanol tolerance and modified the flavor profile of the yeast cells by altering the membrane properties. These results indicate that GlcCer from A. kawachii modifies the physiology of the yeast S. cerevisiae and demonstrate a new mechanism for cooperation between microbes in food fermentation. 相似文献
55.
56.
Effects of struvite formation and nitratation promotion on nitrogenous emissions such as NH3, N2O and NO during swine manure composting 总被引:4,自引:0,他引:4
To reduce nitrogenous emissions from composting, two different countermeasures were applied simultaneously in swine manure composting. One was forming struvite by adding Mg and P at the start of composting, and the other was to promote nitratation (nitrite being oxidized nitrate) by adding nitrite-oxidizing bacteria after the thermophilic phase of composting. In the laboratory- and mid-scale composting experiments, 25-43% of NH3, 52-80% of N2O and 96-99% of NO emissions were reduced. From the nitrogen balance, it was revealed that the struvite formation reduced not only NH3, but also other nitrogenous emissions except N2O. The amount of total nitrogen losses was reduced by 60% by the two combined countermeasures, against 51% by the struvite formation alone. However, the nitratation promotion dissolved struvite crystals due to the pH decline, diminishing the effect of struvite as a slow-release fertilizer. 相似文献
57.
Prangsaengtong O Koizumi K Senda K Sakurai H Saiki I 《Lymphatic research and biology》2011,9(1):53-59
Endothelial nitric oxide synthase (eNOS) and heat shock protein 90 (Hsp90) have been reported to contribute to angiogenesis and lymphangiogenesis. However, the functions of these proteins during lymphangiogenesis are unclear. In the present study, we first observed the cord formation pattern of human dermal microvascular lymphatic endothelial cells (HMVEC-dLy) on Matrigel over 2 to 8?h. The length of cord formation increased, peaked at 4?h, and then started to decline after 6 to 8?h of incubation. siRNA-targeted NOS3 significantly reduced the cord formation ability of HMVEC-dLy cells by 27% relative to control. This result confirmed the importance of eNOS in cord formation by human lymphatic endothelial cells. In addition, immunoprecipitation and Western blotting indicated that the interaction between eNOS and Hsp90 was maximal at 4?h, and then the proteins dissociated. This interaction correlated with the observation of cord formation of human lymphatic endothelial cells on Matrigel. Moreover, we found that the eNOS level decreased as the eNOS and Hsp90 complex disassociated during the late stage of cord formation. An Hsp90 inhibitor, 17-DMAG, was able to inhibit the eNOS and Hsp90 interaction, decrease the level of eNOS, and significantly inhibit cord formation to 38% of the level observed in the control. For the first time, we report that the interaction between eNOS and Hsp90 plays an important role in determining eNOS levels and in regulating cord formation of human lymphatic endothelial cells in vitro. 相似文献
58.
Antimalarial activity of endoperoxide compound 6-(1,2,6,7-tetraoxaspiro[7.11]nonadec-4-yl)hexan-1-ol
Sato A Hiramoto A Morita M Matsumoto M Komich Y Nakase Y Tanigawa N Hiraoka O Hiramoto K Hayatsu H Higaki K Kawai S Masuyama A Nojima M Wataya Y Kim HS 《Parasitology international》2011,60(3):270-273
Plasmodium falciparum, the major causative parasite for the disease, has acquired resistance to most of the antimalarial drugs used today, presenting an immediate need for new antimalarial drugs. Here, we report the in vitro and in vivo antimalarial activities of 6-(1,2,6,7-tetraoxaspiro[7.11]nonadec-4-yl)hexan-1-ol (N-251) against P. falciparum and Plasmodium berghei parasites. The N-251 showed high antimalarial potencies both in the in vitro and the in vivo tests (EC50 2.3 × 10−8 M; ED50 15 mg/kg (per oral)). The potencies were similar to that of artemisinin in vitro and greater than artemisinin's activity in vivo (p.o.). In addition, N-251 has little toxicity: a single oral administration at 2000 mg/kg to a rat gave no health problems to it. Administration of N-251 to mice bearing 1% of parasitemia (per oral 68 mg/kg, 3 times a day for 3 consecutive days) resulted in a dramatic decrease in the parasitemia: all the 5 mice given N-251 were cured without any recurrence, with no diarrhea or weight loss occurring in the 60 days of experiment. N-251 deserves more extensive clinical evaluation, desirably including future trials in the human. 相似文献
59.
The endoplasmic reticulum (ER) uses an elaborate surveillance system called the ER quality control (ERQC) system. The ERQC facilitates folding and modification of secretory and membrane proteins and eliminates terminally misfolded polypeptides through ER-associated degradation (ERAD) or autophagic degradation. This mechanism of ER protein surveillance is closely linked to redox and calcium homeostasis in the ER, whose balance is presumed to be regulated by a specific cellular compartment. The potential to modulate proteostasis and metabolism with chemical compounds or targeted siRNAs may offer an ideal option for the treatment of disease. 相似文献
60.
Suehara Y Tochigi N Kubota D Kikuta K Nakayama R Seki K Yoshida A Ichikawa H Hasegawa T Kaneko K Chuman H Beppu Y Kawai A Kondo T 《Journal of Proteomics》2011,74(6):829-842
We aimed to develop prognostic biomarkers for synovial sarcoma employing a proteomic approach. We examined the proteomic profile of synovial sarcoma using two-dimensional difference gel electrophoresis (2D-DIGE). We identified 20 protein spots whose intensity was statistically different (p<0.01) between a group of eight patients who were alive and continuously disease-free for over five years and a group of five patients who died of the disease within two years post diagnosis. Mass spectrometric protein identification demonstrated that these 20 spots corresponded to 17 distinct gene products. Three of the 20 spots corresponded to secernin-1 and had higher intensity in the good prognosis group. The prognostic performance of secernin-1 was further examined immunohistochemically in 45 synovial sarcoma cases. The 5-year survival rate was 77.6% and 21.8% for patients with secernin-1 positive and negative primary tumors respectively (p=0.0015). The metastasis-free survival was significantly higher in the patient group with high secernin-1 expression compared to that with low expression (p=0.0012). Uni- and multivariate analyses revealed that secernin-1 expression was a powerful prognostic factor compared to other clinico-pathological parameters examined. These results indicate that secernin-1 may be used as a biomarker to predict the overall and metastasis-free survival in synovial sarcoma patients. 相似文献