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91.
Homer RJ Zheng T Chupp G He S Zhu Z Chen Q Ma B Hite RD Gobran LI Rooney SA Elias JA 《American journal of physiology. Lung cellular and molecular physiology》2002,283(1):L52-L59
Interleukin (IL)-13, a key mediator of Th2-mediated immunity, contributes to the pathogenesis of asthma and other pulmonary diseases via its ability to generate fibrosis, mucus metaplasia, eosinophilic inflammation, and airway hyperresponsiveness. In these studies, we compared surfactant accumulation in wild-type mice and mice in which IL-13 was overexpressed in the lung. When compared with littermate controls, transgenic animals showed alveolar type II cell hypertrophy under light and electron microscopy. Over time, their alveoli also filled with surfactant in a pulmonary alveolar proteinosis pattern. At the same time, prominent interstitial fibrosis occurs. Bronchoalveolar lavage fluid from these mice had a three- to sixfold increase in surfactant phospholipids. Surfactant proteins (SP)-A, -B, and -C showed two- to threefold increases, whereas SP-D increased 70-fold. These results indicate that IL-13 is a potent stimulator of surfactant phospholipid and surfactant accumulation in the lung. IL-13 may therefore play a central role in the broad range of chronic pulmonary conditions in which fibrosis, type II cell hypertrophy, and surfactant accumulation occur. 相似文献
92.
Optical Single Transporter Recording (OSTR) is a technique for analyzing membrane transport kinetics at high sensitivity, selectivity, and spatial resolution. Cellular membranes are firmly attached to microarrays of small test compartments (TCs) with diameters between approximately 0.1 and 100 microm and depths between approximately 10 and 100 microm. This permits to generate either "small" membrane patches containing few transporters or "large" patches containing many transporters. Transport of substrates across membrane patches is recorded by confocal microscopy. The present article reviews recent applications of OSTR to the nuclear pore complex (NPC). The results show that the transport functions of the NPC, previously studied almost exclusively in intact and permeabilized cells, are conserved in isolated nuclei and can be fully reconstituted in purified nuclear envelopes by addition of recombinant transport factors. This opens new avenues to the analysis of nuclear transport including the export of nucleic-acid-protein and ribosomal particles. 相似文献
93.
Pavlopoulos E Kokkinaki M Koutelou E Mitsiadis TA Prinos P Delidakis C Kilpatrick MW Tsipouras P Moschonas NK 《Biochimica et biophysica acta》2002,1574(3):375-382
The Drosophila neuralized (neur) gene belongs to the neurogenic group of genes involved in regulating cell-cell interactions required for neural precursor development. neur mutant phenotypes include strong overcommitment to neural fates at the expense of epidermal fates. The human neuralized homolog (NEURL) has been recently determined and found to map to chromosome 10q25.1 within the region frequently deleted in malignant astrocytomas. Because of its potential importance in developmental processes, we analyzed the structure of the mouse homolog, Neurl, and its expression pattern in embryonic tissues. Neurl activity is detected from early developmental stages in several tissues and organs including neural tissues, limbs, the skeletal system, sense organs and internal organs undergoing epithelial-mesenchymal interactions. Neurl encodes a polypeptide associated with the plasma membrane but also detected in the cytoplasm. Similarly to the Drosophila gene, mammalian neuralized may code for an important regulatory factor. 相似文献
94.
The aim of this work was to design a biodegradable delivery system for oligonucleotides providing both a sustained release and an improved intracellular penetration. To this purpose oligonucleotide/polyethylenimine (ON/PEI) complexes at nitrogen to phosphate (N/P) molar ratios of about 15 or 40 were encapsulated into poly(lactide-co-glycolide) microspheres by the multiple emulsion-solvent evaporation technique. ON/PEI complexes were efficiently entrapped inside microspheres. The introduction of salts within the external aqueous phase allowed an improvement of microsphere characteristics. In particular, the use of sodium chloride led to a reduced microsphere porosity and a more homogeneous ON distribution inside the polymeric matrix. These effects were attributed to the reduced flux of water from the external aqueous phase toward the internal aqueous droplets, due to the osmotic effect of sodium chloride. Both, the reduced porosity and the improved ON distribution inside the matrix, were considered responsible for the lower burst effect and the slower ON release rate from microsphere prepared with sodium chloride. ON/PEI complexes encapsulated inside microspheres were also protected toward enzymatic degradation in fetal calf serum. Interestingly, ON/PEI complexes slowly released from microspheres efficiently penetrated inside HeLa cells and oligonucleotides were preferentially located in the nucleus. 相似文献
95.
Baritaki S Zafiropoulos A Georgopoulos E Souris S Krambovitis E 《Cancer immunology, immunotherapy : CII》2001,50(2):109-114
It has been demonstrated that IgG antibodies can be generated to self-antigen peptides as well as against viral antigens
by an antigen-specific in vitro immunization system of resting human peripheral B-lymphocytes. Using a synthetic peptide from
the consensus variable tandem-repeat region of the MUC3 mucin (TSSITTTGTTSHSTPSP) as the B cell epitope, we immunized blood
donor B-lymphocytes in vitro and tested for MUC3-specific antibodies by ELISA. After the primary activation step all antibodies
were IgM. At the end of the secondary immunization step we obtained 1.8% (21/1138) of the cultures with IgG-switched antibodies.
In a competitive inhibition ELISA using the MUC1, MUC2, MUC3, MUC4 and PIP2 peptides, only one culture (F8.1) gave satisfactory
specific inhibition. Using this antibody in fluorometric studies, it stained cells from two colon carcinoma cell lines predominantly
in the cytoplasm, whereas those from a breast cancer cell line stained predominantly the cell surface. In a preliminary immunohistological
evaluation with formalin-fixed sections, the antibody appeared to moderately stain colon sections, but not breast sections
or lymph node. This method of in vitro immunization may be a useful tool in generating IgG antibodies specific to self-antigens
and could find applications in tumour targeting and immunotherapy.
Received: 12 October 2000 / Accepted: 11 January 2001 相似文献
96.
On-line monitoring of insect cell cultures used for the production of recombinant proteins with the baculovirus expression vector system (BEVS) provides valuable tools for the optimization, operation, and control of the production process. The relative permittivity (epsilon') and CO(2) evolution rates (CER) were measured on-line using the biomass monitor and the infrared CO(2) analyzer, respectively. The growth and infection phases of two different cell lines, Spodoptera frugiperda (Sf-9) and Trichoplusia ni(High-5), were monitored using the above measurements. These in turn were correlated to the progress of the culture by using the off-line measurements of protein produced, virus titer, and biovolume, which is the product of viable cell density and mean cell volume. The epsilon', CER, and the biovolume profiles were closely matched during the growth phase of cells when grown in a batch or fed batch culture. The relationship became more complex when the cultures were either in stationary phase or in the postinfection phase. The epsilon' profile was found to be a good indicator of the process of synchronous baculoviral infection, showing a plateau between 18 and 24 h postinfection (hpi), the period during which budded virus is produced, and a peak at approximately 48 hpi correlated to the onset of accelerated cell lysis. The CER profile continues to increase after the growth period with a peak around the 24 hpi period, after which there is a decline in the profile corresponding to release of virus as seen from virus titer determinations. This was examined for Sf-9 cultures under conditions of cell densities from 3 to 50 x 10(6) cells/mL and MOI values ranging from 0.001 to 1000. The profiles were found to be similar also in the case of the High-5 cells. Thus both measurements give reliable information regarding the physiological status of the cells as seen from their correlation to virus and protein production. A further combination of these with the off-line measured parameters such as the biovolume and metabolite concentrations can give a more detailed understanding of the process and help in the better design and automation of these processes. 相似文献
97.
Denda M Tsuchiya T Elias PM Feingold KR 《American journal of physiology. Regulatory, integrative and comparative physiology》2000,278(2):R367-R372
Recent studies have shown that psychological stress can influence cutaneous barrier function, suggesting that this form of stress could trigger or aggravate skin disease. In the present study, we demonstrate that transfer of hairless mice to a different cage delays barrier recovery rates. Pretreatment with a phenothiazine sedative, chlorpromazine, before transfer of animals restored the kinetics of barrier recovery toward normal, suggesting that psychological stress is the basis for this alteration in barrier homeostasis. To determine the mechanism linking psychological stress to altered barrier recovery, we first demonstrated that plasma corticosterone levels increase markedly after transfer of animals to new cages and that pretreatment with chlorpromazine blocks this increase. Second, we demonstrated that the systemic administration of corticosterone delays barrier recovery. Finally, we demonstrated that pretreatment with the glucocorticoid receptor antagonist RU-486 blocks the delay in barrier recovery produced by systemic corticosterone, change of cage, or immobilization. These results suggest that psychological stress stimulates increased production of glucocorticoids, which, in turn, adversely affects permeability barrier homeostasis. 相似文献
98.
99.
Mentula S Harmoinen J Heikkilä M Westermarck E Rautio M Huovinen P Könönen E 《Applied and environmental microbiology》2005,71(8):4169-4175
The microbiota of the small intestine is poorly known because of difficulties in sampling. In this study, we examined whether the organisms cultured from the jejunum and feces resemble each other. Small-intestinal fluid samples were collected from 22 beagle dogs with a permanent jejunal fistula in parallel with fecal samples. In addition, corresponding samples from seven of the dogs were collected during a 4-week period (days 4, 10, 14, and 28) to examine the stability of the microbiota. In the jejunal samples, aerobic/facultative and anaerobic bacteria were equally represented, whereas anaerobes dominated in the fecal samples. Despite lower numbers of bacteria in the jejunum (range, 10(2) to 10(6) CFU/g) than in feces (range, 10(8) to 10(11) CFU/g), some microbial groups were more prevalent in the small intestine: staphylococci, 64% versus 36%; nonfermentative gram-negative rods, 27% versus 9%; and yeasts, 27% versus 5%, respectively. In contrast, part of the fecal dominant microbiota (bile-resistant Bacteroides spp., Clostridium hiranonis-like organisms, and lactobacilli) was practically absent in the jejunum. Many species were seldom isolated simultaneously from both sample types, regardless of their overall prevalence. In conclusion, the small intestine contains a few bacterial species at a time with vastly fluctuating counts, opposite to the results obtained for the colon, where the major bacterial groups remain relatively constant over time. Qualitative and quantitative differences between the corresponding jejunal and fecal samples indicate the inability of fecal samples to represent the microbiotas present in the upper gut. 相似文献
100.
Dermitzaki E Tsatsanis C Charalampopoulos I Androulidaki A Alexaki VI Castanas E Gravanis A Margioris AN 《Biochemical and biophysical research communications》2005,327(3):828-836
Protein kinase C (PKC) has recently emerged as mediator of corticotropin-releasing hormone (CRH) effects. Aim of the present study was to study the effects of CRH on each PKC isoenzyme. As a model we have used the PC12 rat pheochromocytoma cell line, expressing the CRH type 1 receptor (CRHR1). Our data were as follows: (a) CRH-induced rapid phosphorylation of conventional PKCalpha and PKCbeta, accompanied by parallel increase of their concentration within nucleus. (b) CRH suppressed the phosphorylation of novel PKCdelta and PKCtheta;, which remained in the cytosol. (c) CRH-induced transient phosphorylation of atypical PKClambda and had no effect on PKCmu. (d) The effect of CRH on each PKC isoenzyme was blocked by a CRHR1 antagonist. (e) Blockade of conventional PKC phosphorylation inhibited CRH-induced calcium ion mobilization from intracellular stores as well as the CRH-induced apoptosis and Fas ligand production. In conclusion, our findings suggest that CRH via its CRHR1 receptor differentially regulates PKC-isoenzyme phosphorylation, an apparently physiologically relevant effect since blockade of conventional PKC phosphorylation abolished the biological effect of CRH. 相似文献