全文获取类型
收费全文 | 892篇 |
免费 | 45篇 |
国内免费 | 2篇 |
出版年
2024年 | 1篇 |
2023年 | 15篇 |
2022年 | 30篇 |
2021年 | 57篇 |
2020年 | 22篇 |
2019年 | 27篇 |
2018年 | 47篇 |
2017年 | 39篇 |
2016年 | 39篇 |
2015年 | 49篇 |
2014年 | 66篇 |
2013年 | 62篇 |
2012年 | 73篇 |
2011年 | 90篇 |
2010年 | 35篇 |
2009年 | 27篇 |
2008年 | 31篇 |
2007年 | 23篇 |
2006年 | 22篇 |
2005年 | 29篇 |
2004年 | 30篇 |
2003年 | 26篇 |
2002年 | 20篇 |
2001年 | 8篇 |
2000年 | 14篇 |
1999年 | 8篇 |
1998年 | 4篇 |
1997年 | 2篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1992年 | 3篇 |
1991年 | 5篇 |
1989年 | 2篇 |
1988年 | 6篇 |
1987年 | 5篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1978年 | 2篇 |
1975年 | 1篇 |
1973年 | 3篇 |
1971年 | 1篇 |
1969年 | 1篇 |
1965年 | 1篇 |
排序方式: 共有939条查询结果,搜索用时 15 毫秒
21.
Molybdenum supply increases root system growth of winter wheat by enhancing nitric oxide accumulation and expression of NRT genes 总被引:1,自引:0,他引:1
Imran Muhammad Sun Xuecheng Hussain Saddam Rana Muhammad Shoaib Saleem Muhammad Hamzah Riaz Muhammad Tang Xiangru Khan Imran Hu Chengxiao 《Plant and Soil》2021,462(1-2):235-244
Plant and Soil - Success in agronomic biofortification of maize and wheat is highly variable. This study aimed to elucidate the differences in uptake and translocation of foliar-applied zinc (Zn)... 相似文献
22.
Ali Meissam Saleem Uzma Anwar Fareeha Imran Muhammad Nadeem Humaira Ahmad Bashir Ali Tahir Atta-ur-rehman Ismail Tariq 《Neurochemical research》2021,46(4):905-920
Neurochemical Research - Alzheimer's disease (AD) is age-dependent neurological disorder with progressive loss of cognition and memory. This multifactorial disease is characterized by... 相似文献
23.
Tipu Muhammad Imran Ashraf Muhammad Yasin Sarwar Nadeem Akhtar Muhammad Shaheen Muhammad Rashid Ali Sajjad Damalas Christos A. 《Journal of Plant Growth Regulation》2021,40(2):774-786
Journal of Plant Growth Regulation - Nickel (Ni) element is strongly phytotoxic at high concentrations for several plants, but due to its dual behavior and complicated chemistry, it has received... 相似文献
24.
25.
Devina Lobine Bryan Pairyanen Gokhan Zengin Mustafa Abdullah Yılmaz Rayene Ouelbani Souheir Bensari Gunes Ak Hassan H. Abdallah Muhammad Imran Mohamad Fawzi Mahomoodally 《化学与生物多样性》2021,18(4):e2000999
Toddalia asiatica (L.) Lam. is extensively used in traditional medicinal systems by various cultures. Despite its frequent use in traditional medicine, there is still a paucity of scientific information on T. asiatica growing on the tropical island of Mauritius. Therefore, the present study was designed to appraise the pharmacological and phytochemical profile of extracts (methanol, ethyl acetate and water) and essential oil obtained from aerial parts of T. asiatica. Biological investigation involved the evaluation of in vitro antioxidant and enzyme inhibitory potentials. The chemical profile of the EO was determined using gas chromatography coupled to mass spectrometry (GC/MS) analysis, while for the extracts, the total phenolic (TPC) and flavonoid content were quantified as well as their individual phenolic compounds by LC/MS/MS. Quinic acid, fumaric acid, chlorogenic acid, quercitrin and isoquercitrin were the main compounds in the extracts. Highest total phenolic (82.5±0.94 mg gallic acid equivalent (GAE/g)) and flavonoid (43.8±0.31 mg rutin equivalent (RE/g)) content were observed for the methanol extract. The GC/MS analysis has shown the presence of 26 compounds with linalool (30.9 %), linalyl acetate (20.9 %) and β-phellandrene (7.9 %) being most abundant components in the EO. The extracts and EO showed notable antioxidant properties, with the methanol extract proved to be superior source of antioxidant compounds. Noteworthy anti-acetylcholinesterase (AChE) and anti-butyrylcholinesterase (BChE) effects were recorded for the tested samples, while only the methanol and ethyl acetate extracts were active against tyrosinase. With respect to antidiabetic effects, the extracts and EO were potent inhibitors of α-glucosidase, while modest activity was recorded against α-amylase. Docking results showed that linalyl acetate has the highest affinity to interact with the active site of BChE with docking score of −6.25 kcal/mol. The findings amassed herein act as a stimulus for further investigations of this plant as a potential source of bioactive compounds which can be exploited as phyto-therapeutics. 相似文献
26.
Farhan Haq Salmaan Sharif Adnan Khurshid Aamer Ikram Imran Shabbir Muhammad Salman Abdul Ahad Muhammad Suleman Rana Aroosha Raja Nazish Badar Hanaa Tashkandi Turki Al Amri Esam I. Azhar Mohammed S. Almuhayawi Steve Harakeh Muhammad Faraz Arshad Malik 《Saudi Journal of Biological Sciences》2021,28(1):942
27.
Haider Karar Muhammad Amjad Bashir Abdul Basit Sagheer Atta Ahmad Ali Anjum Ali Bakhsh Arif Hussain Abid Hameed Yong Wang Reem Atalla Alajmi Dina M. Metwally Muhammad Imran 《Saudi Journal of Biological Sciences》2021,28(4):2366-2373
A study was performed to assess the preference of fourteen mango cultivars for fruit flies and their management by bagging. So the choice of Tephritid flies to mango cultivars during fruiting phase is crucial. Fourteen different cultivars of mango viz., ‘Dusehri’, ‘Malda’, ‘Langra’ early cultivars, ‘Chaunsa’, ‘Fajri Klan’, ‘Sensation’ medium whereas ‘Sanglakhi’, ‘Retaul-12’, ‘Mehmood Khan’, ‘Tukhmi’, ‘Kala Chaunsa’, ‘Chitta Chaunsa’, ‘Dai Wala’ and ‘Sobey De Ting’ late cultivars were assessed for their suitability for fruit flies. The results indicate that the population density of fruit flies was higher on late cultivars like ‘Sanglakhi’ (20.61 percent), ‘Mehmood Khan’ (20.22 percent) and ‘Reutal-12’ (19.92 percent) were proved to be highly susceptible to fruit flies. Among these the cultivar ‘Reutal-12’ was selected being commercial and future cultivar for the management of fruit flies through bagging. The results reported that the attack of tephritid fruit flies and other insect pests were zero in bagged fruits as compared with control. It was further recorded that the bagged fruits has maximum average fruit weight i.e. 203.50 and 197.83 g per fruit was noted in those treatments where butter paper bag and brown paper bag was wrapped with better coloration as compared with un-bagged fruit with 159.5 g per fruit. Similarly, on an average fruit length were more i.e. 90.17, 91.33 mm in bagged fruit and 85.33 in un-bagged fruits. Furthermore, bagged fruits have zero incidence of disease with reduced fruit crack, fruit sunburn, mechanical damage, bird damage, fruit blemished and agrochemical residues on the fruit. So, it is concluded that the special attention should be given on ‘Reutal-12’ for the management of fruit flies when devising an IPM program for the control of fruit flies. Further, bagging has proved to be the good agricultural practices for the production of quality mango. 相似文献
28.
Muhammad Afzal Imran Kazmi Anwarulabedin Mohsin Quazi Aftab Ahmad Fahad A. Al-Abaasi Faisal Imam Khalid Saad Alharbi Sami I. Alzarea Ameeduzzafar Zafar 《Saudi Journal of Biological Sciences》2021,28(6):3418-3423
The 6-shogaol, is a flavanone type flavonoid that is abundant in citrus fruit and has a wide range of pharmacological effects. The present study attempted to evaluate the antiurolithic effect of 6-shogaol on ethylene glycol (EG) and ammonium chloride (AC)-induced experimental urolithiasis in rats. The efficacy of 6-shogaol 50 mg/kg and 100 mg/kg was studied in EG 0.75% (V/V) and AC 1% (W/V) experimentally induced urolithiasis in rats for 21 days. The weight difference, urine volume, the levels of calcium, phosphate, magnesium, oxalate and uric acid in urine was observed. The blood urea nitrogen, creatinine, uric acid in serum and levels of malondialdehyde (MDA) and glutathione (GSH) were also measured. Histopathological analyses in kidneys were also performed. The rats weights were higher in the 6-shogaol groups than the urolithiasis group. EG caused a significant increase in serum creatinine (p < 0.05), BUN (P < 0.001), and uric acid (p < 0.01) while treatment with Cystone (750 mg/kg), and 6-shogaol (50 and 100 mg/kg) showed the significant reduction in increased serum levels of creatinine (p < 0.001), uric acid (p < 0.01) and BUN (p < 0.001). Administration of EG and AC showed statistically significant (p < 0.001) elevated levels of MDA and reduction in GSH levels. Treatment of Cystone (750 mg/kg), and 6-shogaol (50 and 100 mg/kg) significantly (p < 0.001) reduced MDA levels and an increase GSH levels as compared to EG and AC-treated group. The histological findings further attested antiurolithiatic properties of 6-shogaol. The present study attributed clinical shreds of evidence first time that claiming the significant antiurolithic effect of 6-shogaol and could be a cost-effective candidate for the prevention and treatment of urolithiasis. 相似文献
29.
Mohammed Asad Syed Mohammed Basheeruddin Asdaq Yahya Mohzari Ahmed Alrashed Hamdan Najib Alajami Awad Othman Aljohani Abdullah Ali Al Mushtawi Assil Najib Alajmi Hanan Nageeb Alajmi Mohd. Imran Raha Orfali 《Saudi Journal of Biological Sciences》2021,28(6):3490-3496
Background & objectivesRosuvastatin calcium (RC) is a potent and competitive synthetic inhibitor of HMG-CoA reductase used for the treatment of dyslipidemia. Guggulipid obtained from Commiphora mukul is used in the treatment of a wide variety of diseases such as atherosclerosis, hypercholesterolemia, rheumatism, and obesity. The present study evaluates the pharmacokinetic and pharmacodynamic interactions between RC and the standardized guggulipid extract in rats.Materials and methodsThe guggulipid extract was standardized for the presence of guggulsterones. The pharmacokinetic interaction was determined after a single dose administration of RC alone or in combination with the guggulipid extract or after multiple-dose administration of RC alone or RC along with the guggulipid extract for 14 days. To determine the pharmacodynamic interaction, RC and guggulipid extract were administered to hyperlipidemic rats for 14 days. The level of significance was determined using unpaired student’s t-test, one way ANOVA, the post-ANOVA Tukey test.ResultsStandardization of guggulipid extract showed it contains 7.5%w/w of guggulsterones. Guggulipid extract increased the bioavailability of RC in both single-dose and multiple-dose studies. Guggulipid extract reduced the rate of absorption (Ka) of RC but showed an increase in maximum serum concentration (Cmax). An in-vitro study using isolated rat intestine revealed that guggulipid extract decreased the rate of absorption of RC in the intestinal lumen. The hypolipidemic activity of RC was augmented by the guggulipid extract in hyperlipidemic rats.Interpretation & conclusionTherefore it is concluded that guggulipid extract increases the bioavailability of RC by delaying its Ka and augments its hypolipidemic action. However, it is recommended that a combination of RC with guggulipid extract should be used only after an adverse effect(s) of this combination are determined. 相似文献
30.
Waleed H. AlMalki Imran Shahid Ashraf N. Abdalla Ayman K. Johargy Muhammad Ahmed Sajida Hassan 《Saudi Journal of Biological Sciences》2021,28(3):1664-1677
Hepatitis C virus (HCV) subtypes are pre-requisite to predict endemicity, epidemiology, clinical pathogenesis, diagnosis, and treatment of chronic hepatitis C infection. HCV genotypes 4 and 1 are the most prevalent in Saudi Arabia, however; less consensus data exist on circulating HCV subtypes in infected individuals. This study was aimed to demonstrate the virological surveillance, phylogenetic analysis, and evolutionary relationship of HCV genotypes 4 and 1 subtypes in the Saudi population with the rest of the world. Fifty-five clinical specimens from different parts of the country were analyzed based on 5′ untranslated region (5′ UTR) amplification, direct sequencing, and for molecular evolutionary genetic analysis. Pair-wise comparison and multiple sequence alignment were performed to determine the nucleotide conservation, nucleotide variation, and positional mutations within the sequenced isolates. The evolutionary relationship of sequenced HCV isolates with referenced HCV strains from the rest of the world was established by computing pairwise genetic distances and generating phylogenetic trees. Twelve new sequences were submitted to GenBank, NCBI database. The results revealed that HCV subtype 4a is more prevalent preceded by 1a in the Saudi population. Molecular phylogeny predicts the descendants’ relationship of subtype 4a isolates very close to Egyptian prototype HCV strains, while 1a isolates were homogeneous and clustering to the European and North American genetic lineages. The implications of this study highlight the importance of HCV subtyping as an indispensable tool to monitor the distribution of viral strains, to determine the risk factors of infection prevalence, and to investigate clinical differences of treatment outcomes among intergenotypic and intragenotypic isolates in the treated population. 相似文献