全文获取类型
收费全文 | 732篇 |
免费 | 34篇 |
出版年
2024年 | 1篇 |
2023年 | 8篇 |
2022年 | 20篇 |
2021年 | 43篇 |
2020年 | 19篇 |
2019年 | 32篇 |
2018年 | 34篇 |
2017年 | 24篇 |
2016年 | 41篇 |
2015年 | 47篇 |
2014年 | 46篇 |
2013年 | 68篇 |
2012年 | 61篇 |
2011年 | 62篇 |
2010年 | 29篇 |
2009年 | 27篇 |
2008年 | 31篇 |
2007年 | 30篇 |
2006年 | 39篇 |
2005年 | 26篇 |
2004年 | 18篇 |
2003年 | 18篇 |
2002年 | 9篇 |
2001年 | 3篇 |
2000年 | 4篇 |
1999年 | 3篇 |
1998年 | 2篇 |
1997年 | 4篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1994年 | 3篇 |
1993年 | 1篇 |
1990年 | 2篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1984年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有766条查询结果,搜索用时 31 毫秒
731.
Abdulkarim Dakah Salim Zaid Mohamad Suleiman Sami Abbas Michael Wink 《Saudi Journal of Biological Sciences》2014,21(4):317-323
Ziziphora tenuior L. (Lamiaceae) is an aromatic herb used for its medicinal values against fungi, bacteria. Micropropagation can be used for large-scale multiplication of essential oil producing plants thus avoiding an overexploitation of natural resources. This work aims to develop a reliable protocol for the in vitro propagation of Z. tenuior, and to compare the antioxidant activity between in vitro propagated and wild plants.The explants were sterilized and cultured on MS medium containing different concentrations of growth regulators naphthalene acetic acid (NAA) or indole-3-butyric acid (IBA) with 0.5 mg/L of kinetin (Kin) callus formation was 70.2% after 45 days of incubation in dark on medium supplemented with 1.5 mg/L of NAA. After one month of callus culture on medium supplemented with 2 mg/L BA the shoot number was 5.12 and for the multiplication stage. The shoot number was 4.21 and length was 6.17 cm on medium supplemented with 1 mg/L Kin + 0.1 mg/L NAA.DPPH• reagent was used to test the antioxidant activity. The aqueous and methanol extracts of in vitro plants which were treated with 1.5 and 1 mg/L of kin plus 0.1 mg/L of NAA showed a strong DPPH• scavenging activity where IC50 was 0.307 and 0.369 mg/ml, respectively, while the IC50 of aqueous and methanol extracts of wild plants was 0.516 and 9.229 mg/ml, respectively. Our results suggested that plant growth regulators and in vitro culture conditions increased the antioxidant activity. 相似文献
732.
733.
Saleh Jaweesh Mayyas Hammadeh Mohamad Eid Dahadhah Fatina W. Al Zoubi Mazhar Salim Amor Houda 《Molecular biology reports》2022,49(5):3609-3616
Molecular Biology Reports - Idiopathic male infertility can be attributed to genetic predispositions that affect sperm performance and function. Genetic alterations in the mitochondrial DNA (mtDNA)... 相似文献
734.
Underneath the intricacy of every cancer lies mysterious events that impel the tumour cell and its posterity into abnormal growth and tissue invasion. Oncogenic mutations disturb the regulatory circuits responsible for the governance of versatile cellular functions, permitting tumour cells to endure deregulated proliferation, resist to proapoptotic insults, invade and erode normal tissues and above all escape apoptosis. This disruption of apoptosis has been highly implicated in various malignancies and has been exploited as an anticancer strategy. Owing to the fact that apoptosis causes minimal inflammation and damage to the tissue, apoptotic cell death-based therapy has been the centre of attraction for the development of anticancer drugs. Increased understanding of the molecular pathways underlying apoptosis has enabled scientists to establish unique approaches targeting apoptosis pathways in cancer therapeutics. In this review, we reconnoitre the two major pathways (intrinsic and extrinsic) targeted cancer therapeutics, steering toward chief modulators of these pathways, such as B-cell lymphoma 2 protein family members (pro- and antiapoptotic), inhibitor of apoptosis proteins, and the foremost thespian of extrinsic pathway regulator, tumour necrosis factor-related apoptosis-inducing agent. Together, we also will have a look from clinical perspective to address the agents (drugs) and therapeutic strategies adopted to target these specific proteins/pathways that have entered clinical trials. 相似文献
735.
Taranjeet Kaur Jeffrine Rovie Ryan Japning Mohamad Shahbudin Sabki Irvan Sidik Lee Kim Chong Alan H. K. Ong 《Biochemical genetics》2013,51(3-4):275-295
The genetic diversity of the endangered crocodile Tomistoma schlegelii was characterized using the protein coding ND 6-tRNAglu-cyt b and the cytochrome b-control region (cyt b-CR) markers. Concatenate data revealed six haplotypes with an overall haplotype diversity of 0.769 ± 0.039; nucleotide diversity was 0.00535 ± 0.00172. A nearest-neighbor analysis showed that all individuals clustered with four geographic regions (Sumatra, Peninsular Malaysia, Sarawak, and East Kalimantan) and were genetically differentiated. With the exception of the individuals from haplotype H2, which occurred in both Peninsular Malaysia and Sarawak, all other haplotypes were geographically distinct. The H4 lineage, which was found to be the most divergent, clustered exclusively in the basal clade in all phylogenetic trees, and the haplotype network was unconnected at the 95% reconnection limit, suggesting further investigation to establish its possible status as a distinct evolutionary significant unit or a cryptic species. 相似文献
736.
Jin-Hui Hor Munirah Mohamad Santosa Valerie Jing Wen Lim Beatrice Xuan Ho Amy Taylor Zi Jian Khong John Ravits Yong Fan Yih-Cherng Liou Boon-Seng Soh Shi-Yan Ng 《Cell death and differentiation》2021,28(4):1379
Motor neurons (MNs) are highly energetic cells and recent studies suggest that altered energy metabolism precede MN loss in amyotrophic lateral sclerosis (ALS), an age-onset neurodegenerative disease. However, clear mechanistic insights linking altered metabolism and MN death are still missing. In this study, induced pluripotent stem cells from healthy controls, familial ALS, and sporadic ALS patients were differentiated toward spinal MNs, cortical neurons, and cardiomyocytes. Metabolic flux analyses reveal an MN-specific deficiency in mitochondrial respiration in ALS. Intriguingly, all forms of familial and sporadic ALS MNs tested in our study exhibited similar defective metabolic profiles, which were attributed to hyper-acetylation of mitochondrial proteins. In the mitochondria, Sirtuin-3 (SIRT3) functions as a mitochondrial deacetylase to maintain mitochondrial function and integrity. We found that activating SIRT3 using nicotinamide or a small molecule activator reversed the defective metabolic profiles in all our ALS MNs, as well as correct a constellation of ALS-associated phenotypes.Subject terms: Neuroscience, Pathogenesis 相似文献
737.
Kouadio Ibrahime Sinan Gokhan Zengin Antonio Fiorentino Brigida D'Abrosca Gunes Ak Devina Lobine Ouattara Katinan Etienne Anwar Hussein Subratty Mohamad Fawzi Mahomoodally 《化学与生物多样性》2021,18(10):e2100371
Spermacoce verticillata (L.) G. Mey. is commonly used in the folk medicine by various cultures to manage common diseases. Herein, the chemical and biological profiles of S. verticillata were studied in order to provide a comprehensive characterization of bioactive compounds and also to highlight the therapeutic properties. The in vitro antioxidant activity using free-radical scavenging, phosphomolybdenum, ferrous-ion chelating and reducing power assays, and the inhibitory activity against key enzymes such as acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), tyrosinase, α-amylase and α-glucosidase of S. verticillata extracts (dichloromethane, ethyl acetate, methanol and water) were investigated. The highest total phenolic and flavonoid content were observed in the methanolic and aqueous extracts. Exhaustive 2DNMR investigation has revealed the presence of rutin, ursolic and oleanoic acids. The methanolic extract, followed by aqueous extract have showed remarkable free radical quenching and reducing ability, while the dichloromethane extract was the best source of metal chelators. The tested extracts showed notable inhibitory activity against cholinesterases (AChE: 1.63–4.99 mg GALAE/g extract and BChE: 12.40–15.48 mg GALAE/g extract) and tyrosinase (60.85–159.64 mg KAE/g extract). No inhibitory activity was displayed by ethyl acetate and aqueous extracts against BChE and tyrosinase, respectively. All the tested extracts showed modest α-amylase inhibitory activity, while only the ethyl acetate and aqueous extracts were potent against α-glycosidase. This study further validates the use of S. verticillata in the traditional medicine, while advocating for further investigation for phytomedicine development. 相似文献
738.
A R Romm I M Rosly? A V Kozlov O A Azizova Iu A Vladimirov 《Biulleten' eksperimental'no? biologii i meditsiny》1988,105(6):672-674
Ceruloplasmin and transferrin blood serum levels were measured during bacterial infection of the CNS. A decrease in ceruloplasmin level and a gradual increase in transferrin level were observed on the 5th day of the disease. The minimum ceruloplasmin level was observed simultaneously with the maximum MDA and GOT levels. There was a close correlation between the time course of ceruloplasmin, transferrin, MDA and GOT changes and the clinical condition of the patient. 相似文献
739.
Dea Silviani Safirah Zam Astari Dewi Anggraini Septianingsih Alfi Hudatul Karomah Auliya Ilmiawati Utami Dyah Syafitri Wulan Tri Wahyuni Nanik Siti Aminah Muhamad Insanu Abdul Rohman Mohamad Rafi 《化学与生物多样性》2023,20(6):e202201042
Plant organs and cultivation ages can result in different compositions and concentration levels of plant metabolites. The metabolite profile of plants can be determined using liquid chromatography. This study determined the metabolite profiles of leaves, stems, and roots of Sida rhombifolia at different cultivation ages at 3, 4, and 5 months post-planting (MPP) using liquid chromatography-mass spectrometry/mass spectrometry (LC/MS/MS). The results identified that 41 metabolites in S. rhombifolia extract for all plant organs and cultivation ages. We successfully identified approximately 36 (leaves), 22 (stems), and 18 (roots) compounds in all extract. Using principal component analysis (PCA) with peak area as the variable, we clustered all sample extracts based on plant organs and cultivation ages. As a result of PCA, S. rhombifolia extracts were grouped according to plant organs and cultivation ages. In conclusion, a clear difference in the composition and concentration levels of metabolites was observed in the leaves, stems, and roots of S. rhombifolia harvested at 3-, 4-, and 5-MPP. 相似文献
740.
Agung Dhamar Syakti Mohamad Yani Nuning Vita Hidayati Asrul Sahri Siregar Pierre Doumenq I. M. Made Sudiana 《Bioremediation Journal》2013,17(1):11-20
The main purpose of the study was to isolate strains of bacteria capable of degrading hydrocarbons from contaminated mangroves and to investigate the ability of the isolated bacteria to degrade total petroleum hydrocarbons (TPH) in a microcosm model of an oily sludge. The potential use of these bacteria strains as environmental clean-up agents was tested by culturing them with six different polyaromatic hydrocarbon (PAH) compounds (phenothiazine, fluorene, fluoranthene, dibenzothiophene, phenanthrene, and pyrene). Six viable and culturable bacteria were isolated, and the 16S rDNA sequence for each was amplified using the primers 9F and 1510R. Sequence results were compared using the National Center for Biotechnology Information (NCBI) BLAST program and, combined with phenotypic and phylogenetic data, were used to identify three strains that belonged to the Bacillus genus and were most closely related (98–99%) to Bacillus aquimaris, Bacillus megaterium, and Bacillus pumilus. The other three strains were closely related (98–100%) to Flexibacteraceae bacterium, Halobacilus trueperi, and Rhodobacteraceae bacterium. Two isolates, BA-PZN and BM-PFFP, which were related to Bacillus aquimaris and Bacillus megaterium, respectively, were further characterized and showed great potential for the removal of more complex hydrocarbon compounds in the oily microcosm model. 相似文献