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991.
Yin Li Zhiqiang Liu Fengjie Cui Yingying Xu Hui Zhao 《World journal of microbiology & biotechnology》2007,23(6):837-843
A new strain of Penicillium sp. ZH-30 that produces xylanase was isolated from soil. According to the morphology and comparison of internal transcribed
spacer (ITS) rDNA gene sequence, the strain Penicillium sp. ZH-30 was identified as a strain of Penicillium oxalicum. When xylan or wheat bran was used as substrate at 30°C for 3 days under submerged cultivation, xylanase production was 5.3
and 13.3 U ml−1, respectively. The temperature and pH for optimum activity were 50°C and 5.0–6.0, respectively. 相似文献
992.
Climate and species affect fine root production with long-term fertilization in acidic tussock tundra near Toolik Lake,Alaska 总被引:3,自引:0,他引:3
Long-term fertilization of acidic tussock tundra has led to changes in plant species composition, increases in aboveground
production and biomass and substantial losses of soil organic carbon (SOC). Root litter is an important input to SOC pools,
although little is known about fine root demography in tussock tundra. In this study, we examined the response of fine root
production and live standing fine root biomass to short- and long-term fertilization, as changes in fine root demography may
contribute to observed declines in SOC. Live standing fine root biomass increased with long-term fertilization, while fine
root production declined, reflecting replacement of the annual fine root system of Eriophorum vaginatum, with the long-lived fine roots of Betula nana. Fine root production increased in fertilized plots during an unusually warm growing season, but remained unchanged in control
plots, consistent with observations that B. nana shows a positive response to climate warming. Calculations based on a few simple assumptions suggest changes in fine root
demography with long-term fertilization and species replacement could account for between 20 and 39% of the observed declines
in SOC stocks. 相似文献
993.
Chemotherapy and zoledronate sensitize solid tumour cells to Vγ9Vδ2 T cell cytotoxicity 总被引:1,自引:0,他引:1
Combinations of cellular immune-based therapies with chemotherapy and other antitumour agents may be of significant clinical
benefit in the treatment of many forms of cancer. Gamma delta (γδ) T cells are of particular interest for use in such combined
therapies due to their potent antitumour cytotoxicity and relative ease of generation in vitro. Here, we demonstrate high
levels of cytotoxicity against solid tumour-derived cell lines with combination treatment utilizing Vγ9Vδ2 T cells, chemotherapeutic
agents and the bisphosphonate, zoledronate. Pre-treatment with low concentrations of chemotherapeutic agents or zoledronate
sensitized tumour cells to rapid killing by Vγ9Vδ2 T cells with levels of cytotoxicity approaching 90%. In addition, zoledronate
enhanced the chemotherapy-induced sensitization of tumour cells to Vγ9Vδ2 T cell cytotoxicity resulting in almost 100% lysis
of tumour targets in some cases. Vγ9Vδ2 T cell cytotoxicity was mediated by perforin following TCR-dependent and isoprenoid-mediated
recognition of tumour cells. Production of IFN-γ by Vγ9Vδ2 T cells was also induced after exposure to sensitized targets.
We conclude that administration of Vγ9Vδ2 T cells at suitable intervals after chemotherapy and zoledronate may substantially
increase antitumour activities in a range of malignancies.
Financial
support and conflicts of interest: This study was supported by grants from Medinet (Japan), and Suncorp Metway and Gallipoli Research Foundation (Australia).
No financial or commercial interests arise from this study. Informed consent: This study was approved by Human Research Ethics Committees of the University of Queensland and Greenslopes Private Hospital
and informed consent was obtained from all subjects. 相似文献
994.
995.
This work was to characterize the generation of nitric oxide (NO) in Taxus yunnanensis cells induced by a fungal-derived cerebroside and the signal role of NO in the elicitation of plant defense responses and
taxol production. (2S,2′R,3R,3′E,4E,8E)-1-O-β-d-glucopyranosyl-2-N-(2′-hydroxy-3′-octadecenoyl)-3-hydroxy-9-methyl-4,8-sphingadienine at 10 μg/ml induced a rapid and dose-dependent NO production
in the Taxus cell culture, reaching a maximum within 5 h of the treatment. The NO donor sodium nitroprusside (SNP) potentiated cerebroside-induced
H2O2 production and cell death. Inhibition of nitric oxide synthase activity by phenylene-1,3-bis(ethane-2-isothiourea) dihydrobromide
or scavenging NO by 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide partially blocked the cerebroside-induced
H2O2 production and cell death. Moreover, NO enhanced cerebroside-induced activation of phenylalanine ammonium-lyase and accumulation
of taxol in cell cultures. These results are suggestive of a role for NO as a new signal component for activating the cerebroside-induced
defense responses and secondary metabolism activities of plant cells.
Taxol is a trademark of Bristol-Myers Squibb, Madison, NJ. 相似文献
996.
Pantolestinae is a eutherian subfamily of mammals whose members are known from the middle early Paleocene through at least
the beginning of the Oligocene of North America. They are also known from Europe, and possibly Africa. A lack of information
on pantolestine skulls has prevented the use of cranial anatomy in evaluation of this group’s enigmatic higher-level phylogenetic
relationships. Conversely, postcranial skeletons are well known and locomotor interpretations based on them are robust. The
most complete known skull of a pantolestine, Pantolestes longicaudus (YPM 13525), is described here and compared to potential close fossil relatives and extant mammals. Semicircular canal morphology
is used to test locomotor hypotheses.
YPM 13525 lacks an ossified bulla. It has a mediolaterally broad basioccipital, a large entoglenoid process, and a deeply
incised glaserian fissure of the squamosal, caudal and rostral tympanic processes on the petrosal, a foramen for an internal
carotid artery (ICA) that entered the tympanic cavity from a posteromedial position, bony tubes enclosing the main stem and
transpromontorial branch of the ICA, a large anterior carotid foramen formed within the basisphenoid, evidence of a stapedial
artery ramus superior, a groove on the dorsal aspect of the basisphenoid leading to the piriform fenestra possibly for drainage
of the cavernous sinus to an extracranial inferior petrosal sinus, a dorsum sellae with well-developed posterior clinoid processes,
a foramen rotundum within the alisphenoid, and a sphenorbital fissure between the alisphenoid and orbitosphenoid. Overall,
the morphology is not strikingly similar to any potential close relative and the phylogenetic position of Pantolestinae cannot
be estimated without cladistic analysis of a character matrix that includes this new morphology and broadly samples extant
and extinct eutherian taxa. Semicircular canal morphology differs from that of two likely terrestrial Paleocene mammals, Aphronorus (another pantolestid) and Eoryctes (a palaeoryctid), suggesting a different, possibly semi-aquatic, lifestyle for Pantolestes. 相似文献
997.
998.
Plants have large families of proteins sharing a conserved eight-cysteine-motif (8CM) domain. The biological functions of
these proteins are largely unknown. EARLI1 is a cold responsive Arabidopsis gene that encodes a hybrid proline-rich protein (HyPRP) with a three-domain architecture:
a putative signal peptide at the N-terminus, a proline-rich domain (PRD) in the middle, and an 8CM domain at the C-terminus.
We report here that yeast cells expressing different EARLI1 genes had significantly higher rates of freezing survival than empty-vector transformed controls. Arabidopsis plants with
knocked down EARLI1 genes had an increased tendency for freezing-induced cellular damage. EARLI1-GFP fluorescence in transgenic plants and immunoblot
analyses using protoplasts suggested cell wall localization for EARLI1 proteins. Immunoblot analyses showed that EARLI1 proteins
form higher order complexes in plants, and that the PRD is a soluble and the 8CM an insoluble protein domain. We propose that
EARLI1 proteins have a bimodular architecture in which the PRD may interact with the cell wall and the 8CM domain with the
plasma membrane to protect the cells during freezing stress. 相似文献
999.
1000.
Tannins occur commonly in the wastewaters from forestry, plant medicine, paper and leather industries. The treatment of this
kind of wastewaters, including settling and biodegradation, is usually difficult because tannins are highly soluble in water
and would inhibit the growth of microorganisms in activated sludge. The objective of this study is to investigate biodegradability
of tannin-containing wastewaters, so as to characterize the pollution properties of such wastewaters and provide a reference
for their biological treatment in wastewater treatment plants. The research was typified by using the wastewater collected
from vegetable tanning process in leather industry. A model was developed to describe the activated sludge process, and the
biodegradation kinetics of vegetable tanning wastewater (VET wastewater) was studied. It was found that the biodegradability
of tannin-containing wastewater varies heavily with the content of tannins in wastewater. The biodegradation of VET wastewater
with tannin content around 4,900 mg/l occurred inefficiently due to the inhibition of tannins to the activated sludge process,
and only 34.7% of biodegradation extent was reached in 14 days of incubation. The optimal biodegradability of VET wastewater
was observed when its tannin content was diluted to 490 mg/l, where the COD and tannin removals reached 51.3% and 45.1% respectively
in 6 days. Hence, it is suggested that a proper control of tannin content is necessary to achieve an effective biodegradation
of tannin-containing wastewaters in wastewater treatment plants. 相似文献