全文获取类型
收费全文 | 541篇 |
免费 | 31篇 |
国内免费 | 1篇 |
出版年
2024年 | 3篇 |
2023年 | 5篇 |
2022年 | 8篇 |
2021年 | 16篇 |
2020年 | 10篇 |
2019年 | 20篇 |
2018年 | 17篇 |
2017年 | 11篇 |
2016年 | 13篇 |
2015年 | 21篇 |
2014年 | 25篇 |
2013年 | 38篇 |
2012年 | 37篇 |
2011年 | 24篇 |
2010年 | 20篇 |
2009年 | 19篇 |
2008年 | 22篇 |
2007年 | 21篇 |
2006年 | 21篇 |
2005年 | 19篇 |
2004年 | 20篇 |
2003年 | 24篇 |
2002年 | 12篇 |
2001年 | 12篇 |
2000年 | 10篇 |
1999年 | 4篇 |
1998年 | 4篇 |
1997年 | 5篇 |
1996年 | 3篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1989年 | 3篇 |
1988年 | 5篇 |
1987年 | 3篇 |
1986年 | 3篇 |
1984年 | 3篇 |
1983年 | 5篇 |
1982年 | 2篇 |
1978年 | 4篇 |
1976年 | 7篇 |
1975年 | 8篇 |
1974年 | 6篇 |
1973年 | 8篇 |
1972年 | 6篇 |
1971年 | 10篇 |
1970年 | 5篇 |
1969年 | 5篇 |
1968年 | 4篇 |
1967年 | 6篇 |
1966年 | 3篇 |
排序方式: 共有573条查询结果,搜索用时 31 毫秒
1.
Anthony J. Hesketh Caroline Maloney Christopher A. Behr Morris C. Edelman Richard D. Glick Yousef Al-Abed Marc Symons Samuel Z. Soffer Bettie M. Steinberg 《PloS one》2015,10(12)
Metastatic Ewing Sarcoma carries a poor prognosis, and novel therapeutics to prevent and treat metastatic disease are greatly needed. Recent evidence demonstrates that tumor-associated macrophages in Ewing Sarcoma are associated with more advanced disease. While some macrophage phenotypes (M1) exhibit anti-tumor activity, distinct phenotypes (M2) may contribute to malignant progression and metastasis. In this study, we show that M2 macrophages promote Ewing Sarcoma invasion and extravasation, pointing to a potential target of anti-metastatic therapy. CNI-1493 is a selective inhibitor of macrophage function and has shown to be safe in clinical trials as an anti-inflammatory agent. In a xenograft mouse model of metastatic Ewing Sarcoma, CNI-1493 treatment dramatically reduces metastatic tumor burden. Furthermore, metastases in treated animals have a less invasive morphology. We show in vitro that CNI-1493 decreases M2-stimulated Ewing Sarcoma tumor cell invasion and extravasation, offering a functional mechanism through which CNI-1493 attenuates metastasis. These data indicate that CNI-1493 may be a safe and effective adjuvant agent for the prevention and treatment of metastatic Ewing Sarcoma. 相似文献
2.
Biliary lipid secretion in the rat during infusion of increasing doses of unconjugated bile acids 总被引:5,自引:0,他引:5
The aim of the present study was to examine the secretion of biliary components in rats during infusion of increasing doses of either deoxycholic acid, chenodeoxycholic acid or cholic acid and to test the hypothesis that biliary phospholipids may regulate the hepatic bile acid secretory capacity. Analysis of bile samples, collected every 10 min throughout the infusion period showed that there was an elevation of bile acid, phospholipid, cholesterol and alkaline-phosphodiesterase secretion, with all the bile acids, peaking and then gradually declining. Their secretory rates maximum differed and were inversely related to their detergent strength. However, the secretory rates maximum and total output of phospholipids and cholesterol were similar for all bile acids infused. The per cent contribution of phosphatidylcholine to total bile acid-dependent phospholipid secretion was reduced from 84% (in the pre-infusion period) to 59, 46 and 13% at the end of the cholic acid, chenodeoxycholic acid and deoxycholic acid infusions, respectively. This decrease in the per cent contribution of phosphatidylcholine was associated with an increase in the contribution of both sphingomyelin and phosphatidylethanolamine. The biliary phospholipid fatty acid pattern corroborated these changes in the phospholipid classes. Since sphingomyelin and phosphatidylethanolamine are major phospholipids in bile canalicular and other hepatocellular membranes, the marked increase in their secretion in bile during the infusion of high doses of bile acids may indicate solubilization of membrane phospholipids, resulting in membrane structural changes responsible for the reduced excretory function of the liver. 相似文献
3.
Growth kinetics of Lactobacillus acidophilus under ohmic heating 总被引:1,自引:0,他引:1
Lactobacillus acidophilus OSU133 was inoculated into MRS broth in a fermenter vessel and incubated at 30, 35, or 45 degrees C with agitation. Incubation temperatures were attained by conventional or ohmic heating. An electrical current at low (15 V) or high (40 V) voltage was used to heat the culture directly during fermentations under ohmic heating. The growth parameters (lag period, minimum generation time, and maximum growth) and changes in pH were determined during fermentation. Metabolic activities (consumption of glucose and production of lactic acid and bacteriocin) were determined during fermentation at 35 degrees C under both heating methods. Lag period for L. acidophilus was affected appreciably by the method of heating, but the magnitude of these changes depended on the fermentation temperature. When fermentation was done at 30 degrees C, lag period decreased by 94% under low-voltage ohmic, compared with conventional, heating methods. Ohmic heating did not change the generation time significantly and caused slight, but significant (p < 0.01) decrease in maximum growth. Therefore, the electric current enhances the early stages, but it inhibits the late stages of growth. Ohmic, compared with conventional, heating resulted in higher final pH and lower bacteriocin activity in the fermented medium. However, ohmic heating at 35 degrees C had minimal effect on glucose utilization and lactic acid production by L. acidophilus. Results show that measurement of the electric current when ohmic heating is done at a constant voltage may be used in monitoring such fermentations. In conclusion, ohmic heating is potentially useful in certain applications related to fermented foods. (c) 1996 John Wiley & Sons, Inc. 相似文献
4.
Huwida A. A. Abdel-Kader Naeima Yousef Mohammad Anwar Hossain Mona F. A. Dawood 《Phyton》2023,92(7):1955-1974
The extensive use of nanoparticles (NPs) in diverse applications causes their localization to aquatic habitats,
affecting the metabolic products of primary producers in aquatic ecosystems, such as algae. Synthesized calcium
oxide nanoparticles (CaO NPs) are of the scarcely studied NPs. Thus, the current work proposed that the exposure to CaO NPs may instigate metabolic pathway to be higher than that of normally growing algae, and positively
stimulate algal biomass. In this respect, this research was undertaken to study the exposure effect of CaO NPs (0,
20, 40, 60, 80, and 100 µg mL−1
) on the growth, photosynthesis, respiration, oxidative stress, antioxidants, and
lipid production of the microalga Coccomyxa chodatii SAG 216-2. The results showed that the algal growth concomitant with chlorophyll content, photosynthesis, and calcium content increased in response to CaO NPs. The
contents of biomolecules such as proteins, amino acids, and carbohydrates were also promoted by CaO NPs with
variant degrees. Furthermore, lipid production was enhanced by the applied nanoparticles. CaO NPs induced the
accumulation of hydrogen peroxide, while lipid peroxidation was reduced, revealing no oxidative behavior of the
applied nanoparticles on alga. Also, CaO NPs have a triggering effect on the antioxidant enzymes such as superoxide dismutase, catalase, ascorbate peroxidase, and guaiacol peroxidase. The results recommended the importance of the level of 60 µg mL−1 CaO NPs on lipid production (with increasing percentage of 65% compared
to control) and the highest dry matter acquisition of C. chodatii. This study recommended the feasibility of an
integrated treatment strategy of CaO NPs in augmenting biomass, metabolic up-regulations, and lipid accumulation in C. chodatii. 相似文献
5.
Yousef GM 《Biological chemistry》2008,389(6):689-694
6.
Kallikrein-related peptidases (KLKs) are a family of serine proteases that were shown to be useful cancer biomarkers. KLKs have been shown to be dysregulated in prostate cancer (PCa). microRNAs (miRNAs) are short RNA nucleotides that negatively regulate gene expression and have been reportedly dysregulated in PCa. We compiled a comprehensive list of 55 miRNAs that are differentially expressed in PCa from previous microarray analysis and published literature. Target prediction analyses showed that 29 of these miRNAs are predicted to target 10 KLKs. Eight of these miRNAs were predicted to target more than one KLK. Quantitative real-time (qRT)-PCR demonstrated that there was an inverse correlation pattern in the expression (normal vs. cancer) between dysregulated miRNAs and their target KLKs. In addition, we experientially validated the miRNA-KLK interaction by transfecting miR-331-3p and miR-143 into a PCa cell line. Decreased expression of targets KLK4 and KLK10, respectively, and decreased cellular growth were observed. In addition to KLKs, dysregulated miRNAs were predicted to target other genes involved in the pathogenesis of PCa. These data show that miRNAs can contribute to KLK regulation in PCa. The miRNA-KLK axis of interaction projects a new element in the pathogenesis of PCa that may have therapeutic implications. 相似文献
7.
8.
9.
G. Ian Gallicano Martin C. Yousef David G. Capco 《BioEssays : news and reviews in molecular, cellular and developmental biology》1997,19(1):29-36
Oocytes, eggs and blastomeres of the embryo are special cells that undergo rapid changes in structure and function at developmental transitions. These changes are frequently regulated by cytoplasmic signaling events, particularly at the developmental transition of fertilization, because the genome is largely inactivated at this time. Protein kinase C (PKC) is a signaling agent that acts after the sperm-induced rise in calcium and has a central role in the remodeling of the structure of the egg into the zygote in many species. PKC also acts during other developmental transitions. This kinase serves as a chronometer, which can choreograph the cell's remodeling events in both space and time. Several technical advancements discussed in this review have permitted a better understanding of the actions of PKC. 相似文献
10.
In 2014, bark cankers were observed on Caucasian alder (Alnus subcordata) trees in Iran. The disease was characterized by a dark watery liquid often exuding from longitudinal cankers in the bark of the tree trunks which stained the surface. Symptomatic tissue from A. subcordata was sampled from a number of sites in the Mazandaran province. Isolations were performed on nutrient agar supplemented with sucrose (SNA) and yielded bacterial colonies that were uniform, round and whitish. The bacterial strains isolated from alder trees in Iran were similar to Brenneria alni based on phenotypic and genotypic (nucleotide sequences of the 16S rRNA, and housekeeping genes gyrB, and infB) characteristics. The pathogenicity of the representative strains was determined by inoculating stem pieces of A. subcordata. All tested strains caused longitudinal necrotic lesions 30 days after inoculation and were re-isolated from this tissue. To our knowledge, this is the first report of the occurrence of B. alni in Iran, and on A. subcordata globally. 相似文献