全文获取类型
收费全文 | 798篇 |
免费 | 80篇 |
出版年
2023年 | 7篇 |
2022年 | 10篇 |
2021年 | 16篇 |
2020年 | 10篇 |
2019年 | 14篇 |
2018年 | 22篇 |
2017年 | 20篇 |
2016年 | 21篇 |
2015年 | 37篇 |
2014年 | 48篇 |
2013年 | 59篇 |
2012年 | 55篇 |
2011年 | 58篇 |
2010年 | 37篇 |
2009年 | 23篇 |
2008年 | 41篇 |
2007年 | 48篇 |
2006年 | 33篇 |
2005年 | 18篇 |
2004年 | 22篇 |
2003年 | 8篇 |
2002年 | 19篇 |
2001年 | 12篇 |
2000年 | 13篇 |
1999年 | 9篇 |
1998年 | 7篇 |
1997年 | 5篇 |
1992年 | 8篇 |
1990年 | 8篇 |
1989年 | 7篇 |
1988年 | 8篇 |
1987年 | 10篇 |
1985年 | 6篇 |
1984年 | 10篇 |
1983年 | 8篇 |
1982年 | 10篇 |
1981年 | 6篇 |
1980年 | 6篇 |
1979年 | 12篇 |
1978年 | 4篇 |
1976年 | 8篇 |
1975年 | 9篇 |
1974年 | 6篇 |
1973年 | 12篇 |
1972年 | 9篇 |
1971年 | 5篇 |
1970年 | 8篇 |
1969年 | 6篇 |
1968年 | 5篇 |
1965年 | 4篇 |
排序方式: 共有878条查询结果,搜索用时 12 毫秒
821.
Pankaj Kumar Jain Vijai K. Gupta Hardik Pathak Madan Lowry D. P. Jaroli 《World journal of microbiology & biotechnology》2010,26(8):1419-1426
The biodegradability of petroleum hydrocarbons such as polycyclic aromatic hydrocarbons (PAHs) and n-branched alkanes etc. of 2T engine oil were studied in aqueous media using bacterial strain isolated from petroleum contaminated
soil of high altitude. Out of five petroleum degrading bacterial strain one of the most growing bacteria was identified as
Enterobacter strain by morphological, physiological, biochemical and partial sequencing of 16S rDNA. This strain was capable of degrading
75 ± 3% of n-alkanes, 32 ± 5% PAHs, and the abiotic loss was 24 ± 6% during 10 days incubation period. 85 ± 2% of n-alkanes and 51 ± 3% PAHs were biodegraded in 20 days. The abiotic loss during this period was 15 ± 3%. In 30 days of incubation
period 98% ± 1% n-alkanes and 75 ± 3% PAHs were degraded. As expected abiotic losses were smaller with increasing long chain alkanes and PAH’s
concentration. An increment in oil degradation was correlated to an increase in cell number indicating that the bacterial
isolate was responsible for the oil degradation. The hydrocarbon contents were measured by Shimadzu QP-2000 Gas chromatography/mass
spectrometry by ULBON HR-1 column. 相似文献
822.
Xi Xiang Janak Lal Pathak Wenbin Wu Jianwen Li Wenyan Huang Qiuyu Wu Mengyu Xin Yuejun Wu Yuhang Huang Linhu Ge Sujuan Zeng 《Journal of cellular and molecular medicine》2023,27(8):1131-1143
During exogenous bone-graft-mediated bone defect repair, macrophage inflammation dictates angiogenesis and bone regeneration. Exosomes from different human cells have shown macrophage immunomodulation-mediated bone regeneration potential. However, the effect of human serum-derived exosomes (serum-Exo) on macrophage immunomodulation-mediated angiogenesis during bone defect repair has not been investigated yet. In this study, we explored the effects of serum-Exo on macrophage inflammation regulation-mediated angiogenesis during bone defect repair and preliminarily elucidated the mechanism. Healthy serum-Exo was isolated by ultracentrifugation. The effect of serum-Exo on LPS-induced M1 macrophage inflammation was analysed in vitro. The conditioned medium of serum-Exo-treated LPS-induced M1 macrophage (serum-Exo-treated M1 macrophage-CM) was used to culture human umbilical vein endothelial cells (HUVEC), and the effect on angiogenesis was analysed by western blot, qRT-PCR, etc. mRNA-sequencing of HUVECs was performed to identify deferentially expressed genes. Finally, the rat mandibular defect model was established and treated with Bio-Oss and Bio-Oss + Exo. The effect of the Bio-Oss + Exo combination on mandibular bone regeneration was observed by micro-computed tomography (micro-CT), haematoxylin and eosin (HE) staining, Masson staining, and immunohistochemical staining. Serum-Exo promoted the proliferation of RAW264.7 macrophages and reduced the expression of M1-related genes such as IL-6, IL-1β, iNOS, and CD86. Serum-Exo-treated M1 macrophage-CM induced the proliferation, migration, and angiogenic differentiation of HUVEC, as well as the expression of H-type blood vessel markers CD31 and endomucin (EMCN), compared with M1 macrophage-CM. Moreover, higher expression of vascular endothelial adhesion factor 1 (VCAM1) in HUVEC cultured with serum-Exo-treated M1 macrophage-CM compared with M1 macrophages-CM. Inhibition of VCAM1 signalling abrogated the pro-angiogenic effect of serum-Exo-treated M1 macrophage-CM on HUVEC. Local administration of serum-Exo during mandibular bone defect repair reduced the number of M1 macrophages and promoted angiogenesis and osteogenesis. Collectively, our results demonstrate the macrophage inflammation regulation-mediated pro-angiogenic potential of serum-Exo during bone defect repair possibly via upregulation of VCAM1 signalling in HUVEC. 相似文献
823.
Highly Efficient Perovskite Solar Cell Photocharging of Lithium Ion Battery Using DC–DC Booster
下载免费PDF全文
![点击此处可从《Liver Transplantation》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Ashim Gurung Ke Chen Reza Khan Salem Saad Abdulkarim Geetha Varnekar Rajesh Pathak Roya Naderi Qiquan Qiao 《Liver Transplantation》2017,7(11)
Solar cells become a viable energy source to charge lithium ion batteries. Here a simple and efficient photocharging design approach is demonstrated, where a promising low cost single junction solar cell such as perovskite solar cell or dye sensitized solar cell efficiently charges a Li4Ti5O12‐LiCoO2 Li‐ion cell using a DC–DC voltage boost converter. The converter boosts the low input voltage of a single junction solar cell to charge a lithium ion cell and offers advantages including maximum power point tracking of solar photovoltaics and overvoltage protection for the lithium ion cell. This is the first demonstration of this technology. This approach leads to the highest reported overall efficiency of 9.36% and average storage efficiency of 77.2% at 0.5 C discharge for a perovskite solar cell‐converter charging. The high efficiency for the perovskite solar cell‐converter charging is attributed to maximum power harvesting along with high power conversion efficiency of the perovskite solar cell and low potential polarization between the charge and discharge voltage plateaus for the Li4Ti5O12‐LiCoO2 Li‐ion cell. 相似文献
824.
825.
826.
P W Ramteke J W Bhattacharjee S P Pathak N Kalra 《The Journal of applied bacteriology》1992,72(4):352-356
The total and thermotolerant coliform counts in rural drinking water derived from ground water, piped supplies and surface water are reported for a number of areas in India. To evaluate these counts as indicators of recent faecal contamination the total coliforms and thermotolerant coliforms isolated have been identified. Thermotolerant Escherichia coli formed 11.7% of the total coliforms and 75.1% of the thermotolerant coliforms. Citrobacter sp. (20.4%) and Klebsiella sp. (50.9%) were the other common total coliforms isolated and, among the thermotolerant coliforms, Klebsiella sp. (16.4%) was the only other organism frequently encountered. The total coliform counts were significantly correlated with water temperature. The applicability in tropical areas of standards developed for temperate climates is discussed. 相似文献
827.
828.
829.
The P-loop NTPases are involved in diverse cellular functions. Members of the P-loop NTPase superfamily are characterized by
presence of a highly conserved sequence pattern GxxxxGKS/T, known as Walker A motif. This motif adopts an archetypal P-loop
conformation which allows accommodation of the triphosphate moiety of a bound nucleotide. Despite the presence of Walker A as
a common sequence motif, P-loop NTPases exhibit extreme sequence divergence which hampers their phylogenetic or evolutionary
classification. Here, we show that P-loop and its flanking region subsequence (termed as “extended-WalkerA motif”) contain
distinct signatures that can be utilized to classify NTPase domain of functionally diverse proteins. We find a clearly classified
group of diverse NTPases of Conserved Domain Database such as G-proteins, Ylqf, RecA like, DExDc, AAA, CPT, NK, ABC
transporter and NifH proteins. 相似文献
830.
A. R. Pathak 《Plant biosystems》2017,151(1):1-5
Hemidesmus indicus (Asclepiadaceae) leaf explants were utilized for establishing culture in MS medium fortified with individual cytokinins, auxins, and their combinations. Optimum response (80%) was observed in N6-benzyladenine (BA, 20 μM) + indole-3-acetic acid (IAA, 1 μM) with 19.67 ± 0.81 shoots per explant. Roots were induced in ¼MS + indole-3-butyric acid (IBA, 20 μM). 相似文献