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81.
The effects of nitrogen deficiency on selected physiological attributes, phenylalanine ammonia-lyase (PAL, EC. 4.3.1.5) activity,
phenolic contents, peroxidase (EC. 1.11.1.7) and catalase (EC. 1.11.1.6) activities, lipid peroxidation status and H2O2 accumulation were studied in N-deficient Matricaria chamomilla (L.) over 12 days. N deficiency enhanced root growth and inhibited shoot growth. Chlorophyll composition and F
v/F
m were not affected by N stress, but nitrogen and soluble proteins decreased in both the rosettes and the roots. PAL activity,
expressed per mg protein, was enhanced in N-deficient rosettes and tended to decrease by the end of the experiment, while
in the roots PAL activity was maintained. Total phenolic contents increased in both rosettes and roots. Peroxidase and catalase
activities in N-deficient rosettes tended to decrease by the end of the experiment, while in the roots they increased on the
12th day of deficiency. Furthermore, lipid peroxidation status increased in N-deficient roots on the 12th day, indicating
that antioxidative protection was insufficient to scavenge reactive oxygen species being generated. Surprisingly, H2O2 content was even lower in N-deficient roots by the end of the experiment, while in the leaves increased. This observation
in correlation to lipid peroxidation and H2O2 degradation is discussed. The importance of PAL activity and phenolic metabolites in combination with antioxidative enzymes
for plant protection against oxidative stress and the significance of PAL activity for the mobilization of N availability
in N-deficient tissue are also discussed in view of existing information. 相似文献
82.
83.
Ondrusova A Kalavsky E Rudinsky B Freybergh FP Bauer F Miklosko J Huttova M Kisac P Cauda R 《Neuro endocrinology letters》2007,28(Z2):20-21
Risk factors, therapy and outcome of 15 cases of nosocomial meningitis due to Pseudomonas aeruginosa is reviewed. No difference in risk factors was found, however mortality for Ps. aeruginosa was significantly higher (33.3 vs 15.1% p<0.04). 相似文献
84.
Rudinsky B Bauer F Kalavsky M Huttova M Sramka M Kalavsky E Benca J Karvaj M Jarcuska P Liskova A Kralinsky K Ondrusova A Taziarova M Pevalova L Kovac M Miklosko J 《Neuro endocrinology letters》2007,28(Z2):36-37
Meningitis after artificial implants in 60 children, mainly after foreign body infections (FBI) was caused more frequently by coagulase negative staphylococci and Ps. aeruginosa than other organisms and was significantly associated with perinatal trauma, hydrocephalus, haemorrhage or VLBW and had more neurologic sequels despite mortality was similar to other nosocomial meningitis. 相似文献
85.
BACKGROUND AND AIMS: The European Chaerophyllum temulum and two North American Chaerophyllum species have a trans-Atlantic disjunct distribution. This work aimed to resolve requirements for dormancy break and germination of C. temulum seeds and to compare dormancy traits with those of the two North American congeners. METHODS: Phenology of germination and embryo growth was studied by regularly exhuming seeds sown in natural conditions. Temperature requirements for embryo growth, breaking of dormancy and germination were determined by incubating seeds under controlled laboratory conditions. Additionally the effect of GA(3) on germination was tested to determine the specific dormancy type. KEY RESULTS: In natural conditions, embryo growth starts in early winter. Seedlings emerge in late winter shortly after the embryos reached the critical ratio for embryo length to seed length (E : S) of approx. 0.95. Growth of the embryo only occurs during a prolonged incubation period at 5 degrees C. After stratification at 5 degrees C, which breaks physiological and morphological dormancy, seeds can germinate at a wide range of temperatures. GA(3) did not substitute for cold stratification in seeds placed at 23 degrees C. CONCLUSIONS: Chaerophyllum temulum has deep complex morphophysiological dormancy. This dormancy type differs considerably from that of the two North American congeners. 相似文献
86.
Dolashka-Angelova P Stevanovic S Dolashki A Devreese B Tzvetkova B Voelter W Van Beeumen J Salvato B 《Archives of biochemistry and biophysics》2007,459(1):50-58
Hemocyanins of mollusks are high molecular mass glycoproteins with a complex quaternary structure which still remains to be defined in detail for most of its species as far as number, spatial distribution and interactions of their structural units is concerned. In the present study, we isolated the functional units of the structural subunit RvH1 of Rapana venosa hemocyanin, combining enzymatic and non-enzymatic methods. Our results suggest that Hc's carbohydrate moieties play a basic role in the organization of the structural units, resulting from post-translational polymerization of the 50 kDa functional units and involving sugar moieties that link between them. 相似文献
87.
Froyen G Bauters M Boyle J Van Esch H Govaerts K van Bokhoven H Ropers HH Moraine C Chelly J Fryns JP Marynen P Gecz J Turner G 《Human genetics》2007,121(5):539-547
Using high resolution X chromosome array-CGH we identified an interstitial microdeletion at Xp11.23 in three brothers with
moderate to severe mental retardation (MR) without dysmorphic features. The extent of the deletion was subsequently delineated
to about 50 kb by regular PCR and included only the SLC38A5 and FTSJ1 genes. The loss of the FTSJ1 MR gene in males is expected to result in the observed phenotype but the contribution of the deletion of the solute carrier
SLC38A5 gene is less clear. Their mother also carries the deletion and completely inactivates the aberrant X chromosome. Interestingly,
the distal breakpoint is situated within a 200 kb SSX repeat region that appears to stimulate recombination since subtle copy
number changes often occur at this location and it is frequently involved in translocations in tumours. Since this apparent
SSX unstable structure is flanked proximally by FTSJ1 and PQBP1, subtle deletions or duplications at this location would be expected to cause MR, as in our family. So far, we have screened
a cohort of 300 patients but did not find additional aberrations at the FTSJ1 locus indicating that the frequency is likely to be low. 相似文献
88.
A plastid-localized glycogen synthase kinase 3 modulates stress tolerance and carbohydrate metabolism 总被引:1,自引:0,他引:1
Kempa S Rozhon W Samaj J Erban A Baluska F Becker T Haselmayer J Schleiff E Kopka J Hirt H Jonak C 《The Plant journal : for cell and molecular biology》2007,49(6):1076-1090
Glycogen synthase kinase 3 (GSK-3) was originally identified as a regulator of glycogen synthesis in mammals. Like starch in plants, glycogen is a polymer of glucose, and serves as an energy and carbon store. Starch is the main carbohydrate store in plants. Regulation of starch metabolism, in particular in response to environmental cues, is of primary importance for carbon and energy flow in plants but is still obscure. Here, we provide evidence that MsK4, a novel Medicago sativa GSK-3-like kinase, connects stress signalling with carbon metabolism. MsK4 was found to be a plastid-localized protein kinase that is associated with starch granules. High-salt stress rapidly induced the in vivo kinase activity of MsK4. Metabolic profiling of MsK4 over-expressor lines revealed changes in sugar metabolism, including increased amounts of maltose, the main degradation product of starch in leaves. Plants over-expressing MsK4 showed improved tolerance to salt stress. Moreover, under high-salinity conditions, MsK4-over-expressing plants accumulated significantly more starch and showed modified carbohydrate content compared with wild-type plants. Overall, these data indicate that MsK4 is an important regulator that adjusts carbohydrate metabolism to environmental stress. 相似文献
89.
Chrenek P Trandzik J Massanyi P Makarevich A Lukac N Peskovicova D Paleyanda R 《Animal reproduction science》2007,99(1-2):127-134
The influence of foreign transgene integration on the reproductive capabilities of rabbit males is not known. Therefore, we analyzed their ejaculate characteristics, reproductive capabilities, occurrence of pathological spermatozoa and histological structure of the testis. We have generated transgenic rabbits by microinjection of WAP-hFVIII gene into pronucleus of fertilized egg. We observed that the libido, volume and pH value of the ejaculate did not differ significantly between transgenic and non-transgenic male lines. The motility, concentration, osmolarity, thermoresistant test of spermatozoa (at 1 or 6 h) and the percentage of alive spermatozoa were significantly different (p < 0.001) among transgenic and non-transgenic males. No significant differences were found between transgenic and non-transgenic male lines in the occurrence of pathological spermatozoa and histology of the testis. The ability of spermatozoa from transgenic and non-transgenic males to fertilize eggs was ranged within 96 and 100%; while the yield of transgenic embryos ranged from 43 to 57%. Our results show that mammary gland specific over-expression mWAP-hFVIII gene construct does not affect reproductive traits of transgenic rabbit males. 相似文献
90.
The need for alternative ways to control helminth parasites has in recent years led to a boost in vaccination experiments with recombinant antigens. Despite the use of different expression systems, only a few recombinants induced high levels of protection against helminths. This is often attributed to the limitations of the current expression systems. Therefore, the need for new systems that can modify and glycosylate the expressed antigens has been advocated. However, analysis of over 100 published vaccine trials with recombinant helminth antigens indicates that it is often not known whether the native parasite antigen itself can induce protection or, if it does, which epitopes are important. This information is vital for a well-thought-out strategy for recombinant production. So, in addition to testing more expression systems, it should be considered that prior evaluation and characterization of the native antigens might help the development of recombinant vaccines against helminths in the long term. 相似文献