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51.
Hairy root research: recent scenario and exciting prospects 总被引:3,自引:0,他引:3
Guillon S Trémouillaux-Guiller J Pati PK Rideau M Gantet P 《Current opinion in plant biology》2006,9(3):341-346
High stability of the production of secondary metabolites is an interesting characteristic of hairy root cultures. For 25 years, hairy roots have been investigated as a biological system for the production of valuable compounds from medicinal plants. A better understanding of the molecular mechanism of hairy root development, which is based on the transfer of Agrobacterium rhizogenes T-DNA into the plant genome, has facilitated its increasing use in metabolic engineering. Hairy roots can also produce recombinant proteins from transgenic roots, and thereby hold immense potential for the pharmaceutical industry. In addition, hairy roots offer promise for phytoremediation because of their abundant neoplastic root proliferation. Recent progress in the scaling-up of hairy root cultures is making this system an attractive tool for industrial processes. 相似文献
52.
doi: 10.1111/j.1741‐2358.2011.00610.x The effect of osteoporosis on residual ridge resorption and masticatory performance in denture wearers Aim: To compare masticatory performance, masticatory efficiency and residual ridge resorption (RRR) in osteoporotic and non‐osteoporotic edentulous subjects after rehabilitation with complete dentures. Method: Thirty subjects fulfilling the inclusion criteria were enrolled from the patients visiting the Department of Prosthodontics for complete denture fabrication. Two groups consisting of control subjects (group I; N = 15) and osteoporotic subjects (group II; N = 15) were formed. Complete dentures satisfying certain criteria were fabricated for both groups. Masticatory performance and efficiency were measured 6 months after denture insertion. Areal measurements were taken on lateral cephalograms before and 6 months after denture fabrication. The data were then computed to analyse differences between groups I and II using SPSS statistical software version 15.0. Results: Six months after denture fabrication, the masticatory performance and efficiency were significantly higher (p < 0.001) for group I, with a significant decrease in maxillary and mandibular sagittal area seen in both groups. The rate of bone loss was more in group II compared with group I. Conclusion: Greater masticatory function was demonstrated by the non‐osteoporotic group, and the rate of RRR was more in the osteoporotic group compared with the normal group. In this pilot study, osteoporosis leads to greater RRR, decreased masticatory performance and efficiency in edentulous subjects 6 months after denture insertion. Screening for osteoporosis is suggested as a routine procedure for all edentulous subjects undergoing rehabilitation. Recall check‐ups for osteoporotic patients should be more frequent, and these patients may require more frequent denture remakes. 相似文献
53.
doi: 10.1111/j.1741‐2358.2010.00414.x Effect of bone mineral density on masticatory performance and efficiency Objective: To evaluate the effect of bone mineral density (BMD) on masticatory performance and efficiency in dentate subjects. Background data: Osteoporosis is the most common disorder of the bone. It causes reduction in BMD of the all the skeletal tissue including jaw bones. It also promotes bone loss in jaw bones. In osteoporosis, a reduction of maximal bite force and greater electromyography activity of masticatory muscles is documented. This may lead to the development of masticatory dysfunction which can be assessed by a chewing test in the form of change in masticatory performance and efficiency. Materials and methods: Sixty subjects with equal numbers of men and women were selected for the study, in which BMD screening (T‐score) was carried out to identify the normal, osteopenic and osteoporotic subjects. Their masticatory performance and efficiency was evaluated by a chewing test (fractional sieving method). Results: A high ‘T’ score was associated with low masticatory efficiency and a low ‘T’ score with high masticatory efficiency. Masticatory performance and efficiency was significantly higher among males as compared to females with similar range of BMD. Conclusion: In both genders, high BMD groups (low ‘T’ score) had a significantly high percentage of masticatory efficiency compared to the low BMD (high ‘T’ score) group. 相似文献
54.
Parkinson’s disease (PD), a neurodegenerative disorder, is characterized by the selective degeneration of the nigrostriatal
dopaminergic neurons, continuing or permanent deficiency of dopamine, accretion of an abnormal form of alpha synuclein in
the adjacent neurons, and dysregulation of ubiquitin proteasomal system, mitochondrial metabolism, permeability and integrity,
and cellular apoptosis resulting in rigidity, bradykinesia, resting tremor, and postural instability. Melatonin, an indoleamine
produced almost in all the organisms, has anti-inflammatory, anti-apoptotic, and anti-oxidant nature. Experimental studies
employing 1-methyl 4-phenyl 1, 2, 3, 6-tetrahydropyridine (MPTP), 6-hydroxydopamine (6-OHDA), methamphetamine, rotenone, and
maneb and paraquat models have shown an enormous potential of melatonin in amelioration of the symptomatic features of PD.
Although a few reviews published previously have described the multifaceted efficacy of melatonin against MPTP and 6-OHDA
rodent models, due to development and validation of the newer models as well as the extensive studies on the usage of melatonin
in entrenched PD models, it is worthwhile to bring up to date note on the usage of melatonin as a neuroprotective agent in
PD. This article presents an update on the usage and applications of melatonin in PD models along with incongruous observations.
The impending implications in the clinics, success, limitations, and future prospective have also been discussed in this article. 相似文献
55.
56.
Vijay Pratap Singh Prabhat Kumar Srivastava Sheo Mohan Prasad 《Acta Physiologiae Plantarum》2012,34(6):2225-2239
In the present study, impact of low (UV-BL) and high (UV-BH) fluence rates of UV-B on growth, oxidative stress and antioxidant system was studied in two cyanobacteria i.e. Phormidium foveolarum and Nostoc muscorum under Cu (2 and 5???M) toxicity after 24 and 72?h of experiments. UV-BH and Cu treatment decreased growth of both the cyanobacteria and Cu induced decrease in growth was accompanied by a significant increase in Cu accumulation. Levels of reactive oxygen species (ROS), i.e. superoxide radicals (SOR; $ \text O_{2}^{\cdot\,-} $ ) and hydrogen peroxide (H2O2) were significantly increased by Cu and UV-BH exposure which in turn accelerated lipid peroxidation (malondialdehyde: MDA) and protein oxidation (reactive carbonyl groups: RCG). Activities of enzymatic antioxidants, such as superoxide dismutase (SOD), peroxidase (POD) and glutathione-S-transferase (GST) were increased by both doses of Cu as well as UV-B. Conversely, Cu and UV-BH drastically decreased catalase (CAT) activity. After the commencement of 24?h of treatment with Cu alone and together with UV-BH, non-protein thiols (NP-SH) contents were decreased while after 72?h, a reverse trend was noticed. Unlike NP-SH, cysteine content decreased appreciably during the treatments. In contrast to this, low dose (UV-BL) of UV-B did not influence growth, SOR, H2O2, MDA and RCG contents. An improvement in CAT activity and NP-SH content was observed under Cu and UV-BL treatment; hence, UV-BL treatment resulted into certain degree of protection against Cu toxicity in both the organisms. Thus, the results showed that UV-BH and UV-BL exerted differential effects on both the organisms under Cu toxicity, and compared to N. muscorum, P. foveolarum was less affected by Cu and UV-BH. 相似文献
57.
Durgesh Kumar Tripathi Vijay Pratap Singh Dharmendra Kumar Devendra Kumar Chauhan 《Acta Physiologiae Plantarum》2012,34(1):279-289
Hydroponic experiments were conducted to investigate the role of exogenous silicon (Si) addition in increasing hexavalent
chromium (Cr VI) tolerance in rice seedlings. Rice seedlings were grown under 100 μM Cr(VI) stress without or with 10 μM Si.
Chromium treatment decreased growth, photosynthetic pigments and protein, which was accompanied by a significant increase
in Cr accumulation and lipid peroxidation (as malondialdehyde; MDA). However, Si addition alleviated Cr toxicity and promoted
growth of rice by decreasing Cr accumulation, root-to-shoot Cr transport and MDA level. Contents of macro (Mg, Ca and K) as
well as micronutrients (Zn and Fe) were decreased by Cr except Mn while Si addition prevented decrease in these nutrients
induced by Cr. Antioxidant capacity and total phenolic contents were decreased by Cr while these indices improved by Si addition.
Treatment of Cr decreased the length of leaf epidermal cells and stomatal frequency, and adversely affected chloroplasts containing
mesophyll cells and integrity of xylem and phloem, and Si addition minimized these abnormalities. However, frequency of root
hairs was increased by Cr treatment. Results showed that exogenous Si addition enhanced Cr(VI) tolerance in rice seedlings
by decreasing Cr accumulation, root-to-shoot Cr transport and MDA level, and by increasing content of some mineral elements
(K, Fe and Zn) and antioxidant capacity compared to the Cr treatment alone. 相似文献
58.
In order to determine the structural requirements for cytotoxicity against various tumor cell lines, a new series of 16E-arylidene androstene amides with varying degrees of unsaturation in ring A has been synthesized. Characterization and invitro cytotoxic studies of the newly synthesized compounds are discussed. The compounds on evaluation against various tumor cell lines exhibited significant growth inhibition on leukemia cell lines. 3-Chloro-16E-{[4-(4-methylpiperazin-1-yl)-2-oxoethoxy]benzylidene}androst-5-en-17-one (10) emerged as the most potent compound of the series with GI(50) values of 3.94, 2.61, 6.90 and 1.79μM against CCRF-CEM, K-562, RPMI-8226 and SR leukemia cell lines, respectively. 相似文献
59.
A Khamsiriwatchara P Sudathip S Sawang S Vijakadge T Potithavoranan A Sangvichean W Satimai C Delacollette P Singhasivanon S Lawpoolsri J Kaewkungwal 《Malaria journal》2012,11(1):247
ABSTRACT: BACKGROUND: The Bureau of Vector-borne Diseases, Ministry of Public Health, Thailand, has implemented an electronic Malaria Information System (eMIS) as part of a strategy to contain artemisinin resistance. The attempt corresponds to the WHO initiative, funded by the Bill & Melinda Gates Foundation, to contain anti-malarial drug resistance in Southeast Asia. The main objective of this study was to demonstrate the eMIS' functionality and outputs after implementation for use in the Thailand artemisinin-resistance containment project. METHODS: The eMIS had been functioning since 2009 in seven Thai-Cambodian border provinces. The eMIS has covered 61 malaria posts/clinics, 27 Vector-borne Disease Units covering 12,508 hamlets at risk of malaria infections. The eMIS was designed as an evidence-based and near real-time system to capture data for early case detection, intensive case investigation, monitoring drug compliance and on/off-site tracking of malarial patients, as well as collecting data indicating potential drug resistance among patients. Data captured by the eMIS in 2008-2011 were extracted and presented. RESULTS: The core functionalities of the eMIS have been utilized by malaria staff at all levels, from local operational units to ministerial management. The eMIS case detection module suggested decreasing trends during 2009-2011; the number of malaria cases detected in the project areas over the years studied were 3818, 2695, and 2566, with sero-positive rates of 1.24, 0.98, and 1.16%, respectively. The eMIS case investigation module revealed different trends in weekly Plasmodium falciparum case numbers, when classified by responsible operational unit, local and migrant status, and case-detection type. It was shown that most Thai patients were infected within their own residential district, while migrants were infected either at their working village or from across the border. The data mapped in the system suggested that P. falciparum-infected cases and potential drug-resistant cases were scattered mostly along the border villages. The mobile technology application has detected different follow-up rates, with particularly low rates among seasonal and cross-border migrants. CONCLUSION: The eMIS demonstrated that it could capture essential data from individual malaria cases at local operational units, while effectively being used for situation and trend analysis at upper-management levels. The system provides evidence-based information that could contribute to the control and containment of resistant parasites. Currently, the eMIS is expanding beyond the Thai-Cambodian project areas to the provinces that lie along the Thai-Myanmar border. 相似文献
60.
Light and dark have antagonistic effects on shoot elongation, but little is known about how these effects are translated into changes of shape. Here we provide genetic evidence that the light/gibberellin-signaling pathway affects the properties of microtubules required to reorient growth. To follow microtubule dynamics for hours without triggering photomorphogenic inhibition of growth, we used Arabidopsis thaliana light mutants in the gibberellic acid/DELLA pathway. Particle velocimetry was used to map the mass movement of microtubule plus ends, providing new insight into the way that microtubules switch between orthogonal axes upon the onset of growth. Longitudinal microtubules are known to signal growth cessation, but we observed that cells also self-organize a strikingly bipolarized longitudinal array before bursts of growth. This gives way to a radial microtubule star that, far from being a random array, seems to be a key transitional step to the transverse array, forecasting the faster elongation that follows. Computational modeling provides mechanistic insight into these transitions. In the faster-growing mutants, the microtubules were found to have faster polymerization rates and to undergo faster reorientations. This suggests a mechanism in which the light-signaling pathway modifies the dynamics of microtubules and their ability to switch between orthogonal axes. 相似文献