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141.
Joanna Kotwica-Rolinska Barbara O. Gvakharia Urszula Kedzierska Jadwiga M. Giebultowicz Piotr Bebas 《Insect biochemistry and molecular biology》2013,43(6):522-532
Circadian clocks (oscillators) regulate multiple aspects of insect behaviour and physiology. The circadian system located in the male reproductive tract of Lepidoptera orchestrates rhythmic sperm release from testis and sperm maturation in the upper vas deferens (UVD). Our previous research on the cotton leafworm, Spodoptera littoralis, suggested rhythmic changes in the V-ATPase levels in the UVD epithelium, which correlated with rhythmic pH fluctuations in the UVD lumen. However, it was not known whether UVD cells contain clock mechanism that generates these daily fluctuations. In the current paper, we show circadian rhythm in the expression of clock gene period at the mRNA and protein level in the UVD epithelium. To determine the role of PER in V-ATPase and pH regulation, testes–UVD complexes were treated in vitro with double-stranded fragments of per mRNA (dsRNA). This treatment, which transiently lowered per mRNA and protein in the UVD, altered expression of V-ATPase c subunit. In addition, per RNAi caused a significant delay in the UVD lumen acidification. These data demonstrate that the UVD molecular oscillator involving the period gene plays an essential role in the regulation of rhythmic V-ATPase activity and periodic acidification of the UVD lumen. 相似文献
142.
A case of metachronous presentation of two malignancies, invasive mammary ductal adenocarcinoma and later invasive keratinizing squamous cell vulvar carcinoma, complicating a 20 years long course of disseminated discoid lupus erythematosus is described. The authors underline a potential role of long-standing immunotherapy as a factor responsible for inducing secondary neoplasia. 相似文献
143.
144.
Successful cryopreservation of Q. robur germplasm as plumules (i.e. shoot apical meristems of embryos) is described in this paper. After excision from the recalcitrant
seeds and preliminary storage in 0.5 M sucrose solution (18 h), the plumules were subjected to cryoprotection (in 0.75 M sucrose,
followed by 1.0 M sucrose and 1.5 M glycerol solutions), and next to desiccation (over silica gel or in nitrogen gas) and
cooling (in slush at –210°C or in vials filled with liquid nitrogen, LN, −196°C), and were then cryostored for 24 h. High
percentage of survival was obtained after cryostorage (21–67%, depending on pretreatment, assessed in vitro by greening plumules
that increased in size). Desiccation of plumules over silica gel resulted in significantly higher survival after cryopreservation
(58%) in comparison with desiccation in nitrogen gas (29%), with regrowth (shoots with leaves) 5–18%. The extent of plumule
desiccation was comparable in both methods, in which drying of plumules for 20 min decreased the water content to 0.5–0.6
g H2O g−1 dry weight before LN exposure. The type of LN exposure did not significantly influence plumule survival and regrowth after
cryostorage. Plumules isolated from acorns of four provenances survived cryostorage after cryoprotection followed by desiccation
over silica gel and direct cooling in vials with LN (survival 51–76%, regrowth 8–20%). Normal plants developed from the recovered
shoots after rooting. The presented protocol for Q. robur plumule cryopreservation may offer a potential approach for establishing germplasm conservation in gene banks for Quercus species. 相似文献
145.
Wojcieszyńska D Guzik U Greń I Perkosz M Hupert-Kocurek K 《World journal of microbiology & biotechnology》2011,27(4):805-811
Stenotrophomonas maltophilia KB2 is known to produce different enzymes of dioxygenase family. The aim of our studies was to determine activity of these
enzymes after induction by benzoic acids in cometabolic systems with nitrophenols. We have shown that under cometabolic conditions
KB2 strain degraded 0.25–0.4 mM of nitrophenols after 14 days of incubation. Simultaneously degradation of 3 mM of growth
substrate during 1–3 days was observed depending on substrate as well as cometabolite used. From cometabolic systems with
nitrophenols as cometabolites and 3,4-dihydroxybenzoate as a growth substrate, dioxygenases with the highest activity of protocatechuate
3,4-dioxygenase were isolated. Activity of catechol 1,2- dioxygenase and protocatechuate 4,5-dioxygenase was not observed.
Catechol 2,3-dioxygenase was active only in cultures with 4-nitrophenol. Ability of KB2 strain to induce and synthesize various
dioxygenases depending on substrate present in medium makes this strain useful in bioremediation of sites contaminated with
different aromatic compounds. 相似文献
146.
Chojnacka A Błaszczyk MK Szczęsny P Nowak K Sumińska M Tomczyk-Żak K Zielenkiewicz U Sikora A 《Bioresource technology》2011,102(21):10057-10064
A system for biohydrogen production was developed based on long-term continuous cultures grown on sugar beet molasses in packed bed reactors. In two separate cultures, consortia of fermentative bacteria developed as biofilms on granitic stones. In one of the cultures, a granular sludge was also formed. Metagenomic analysis of the microbial communities by 454-pyrosequencing of amplified 16S rDNA fragments revealed that the overall biodiversity of the hydrogen-producing cultures was quite small. The stone biofilm from the culture without granular sludge was dominated by Clostridiaceae and heterolactic fermentation bacteria, mainly Leuconostocaeae. Representatives of the Leuconostocaeae and Enterobacteriaceae were dominant in both the granules and the stone biofilm formed in the granular sludge culture. The culture containing granular sludge produced hydrogen significantly more effectively than that containing only the stone biofilm: 5.43 vs. 2.8 mol H2/mol sucrose from molasses, respectively. The speculations that lactic acid bacteria may favor hydrogen production are discussed. 相似文献
147.
Grześko J Elias M Maczyńska B Kasprzykowska U Tłaczała M Goluda M 《Medycyna do?wiadczalna i mikrobiologia》2007,59(2):169-175
The group of organisms commonly referred to as genital mycoplasmas comprise species most often found in genitourinary tract of sexually active adults as common commensal inhabitants, or pathogens which can possibly cause many different pathologies like: non-gonococcal urethritis, bacterial vaginosis, cervicitis, endometritis or pelvic inflammatory disease. The problem of their morbidity and the possible influence they have on human fertility is still not clear. The aim of this study was to find out whether two investigated species- Ureaplasma urealyticum and Mycoplasma hominis can be detect more often in a group of infertile women. 74 women participated in the study and were assigned to one of 2 groups of patients: infertile women and fertile women without any sign of genital tract infection. Swabs from the cervical canal of the uterus and the fluid from the Douglas pouch were taken during the gynecological examination and laparoscopic procedure. Two diagnostic methods were used: biochemical method- commercial diagnostic kit- Mycoplasma IST 2 and PCR method. The results showed that Ureaplasma urealyticum and Mycoplasma hominis were detected among both fertile and infertile women with nearly the same frequency, much more often in cervical canal than in the Douglas pouch. Ureaplasma urealyticum was more common pathogen than Mycoplasma hominis in both groups and locations. The achieved results point out that the role of genital mycoplasmas in human infertility is still unclear and require further investigations. 相似文献
148.
Historic emissions from a Ni refinery at Port Colborne, Ontario, caused Ni contamination of regional soils and raised concerns
about potential Ni phytotoxicity. Previous tests revealed that if these soils were made alkaline and fertilized with Mn and
other common nutrients as needed to maintain fertility of such alkaline soils, full remediation (prevention of Ni phytotoxicity)
would be obtained. This experiment was conducted to test this method of remediation on diverse soils from Port Colborne, and
to evaluate chemical extraction tests which would be predictive of plant uptake and potential for Ni phytotoxicity in Ni-contaminated
soils. Ten soils with varied levels of Ni contamination and varied soil properties were amended with limestone or nitric acid
to raise or lower pH so that a wide pH range could be examined for the soils. For lower Ni organic and mineral soils near
the Ontario remediation limit (200 mg/kg), neither crop suffered Ni phytotoxicity at any pH tested. Only when more highly
contaminated soils were strongly acidic did Ni phytotoxicity occur. Phytotoxic soils were fully remediated by making soils
alkaline even for these Ni-sensitive crop species. Only the most contaminated organic soil remained slightly toxic – but this
soil was remarkably contaminated (over 1.1% of Ni). The Sr nitrate extraction method was much more effective in predicting
plant Ni concentrations than the DTPA method. This test provides an inexpensive soil extraction result highly predictive of
potential for Ni phytotoxicity across soils. 相似文献
149.
Małolepsza U 《Postepy biochemii》2007,53(3):263-271
There are still many controversial observations and opinions on the cellular/subcellular localization and sources of endogenous nitric oxide synthesis in plant cells. NO can be produced in plants by non-enzymatic and enzymatic systems depending on plant species, organ or tissue as well as on physiological state of the plant and changing environmental conditions. The best documented reactions in plant that contribute to NO production are NO production from nitrite as a substrate by cytosolic (cNR) and membrane bound (PM-NR) nitrate reductases (NR), and NO production by several arginine-dependent nitric oxide synthase-like activities (NOS). The latest papers indicate that mitochondria are an important source of arginine- and nitrite-dependent NO production in plants. There are other potential enzymatic sources of NO in plants including xanthine oxidoreductase, peroxidase, cytochrome P450. 相似文献
150.
Coat colour anomalies in the common shrew, Sorex araneus L., in the geographical range of this species, including Poland, are extremely rare. This study describes atypically coloured common shrews. Light colouration of the coat is a result of lack ofpigment in the entire hair or hair fragments. It appears that atypically coloured shrews occur more often in isolated populations whose gene transfer with neighboring populations is limited. 相似文献