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91.
Adrenocorticotrophic hormone (ACTH) is essential for developmental maturation of numerous organ systems during the fetal period and for adaptation to environmental challenges. Immunocytochemical and stereological methods were used in the present study to examine the effects of dexamethasone (Dx) administration during pregnancy on fetal rat pituitary ACTH-producing cells. Doses of 0.5, 0.5 and 1.0 mg Dx/kg body weight/day were given to the dams on 3 consecutive days starting on day 16 of gestation. Morphometric analysis of the ACTH-producing cells of fetuses at 21 days of gestation revealed significant inhibition by 24% and 27%, respectively, of cell volume and cell number after maternal Dx administration, whereas the volume of cell nuclei and volume density of ACTH-stained cells were insignificantly decreased. Immunocytochemical analysis showed reduced numbers, sizes and immunopositivity of ACTH cells of 21-day-old fetuses from Dx-treated dams as compared with the control group. Maternal Dx treatment in the period of intense differentiation of the hypothalamo-hypophyseal-adrenal system had an inhibitory effect on fetal function and proliferative activity of ACTH-producing cells at 21 days of gestation. Thus, inhibition of activity of fetal ACTH-producing cells may lead to adrenal suppression, modified activity of the hypothalamo-pituitary-adrenal axis and reduced body weight possibly causing lasting functional abnormalities. 相似文献
92.
G. Wambach S. Götz G. Suckau G. Bönner W. Kaufmann 《Journal of molecular medicine (Berlin, Germany)》1987,65(5):232-237
Summary Plasma levels of -human atrial natriuretic peptide (hANP) were measured in 17 patients with primary hypertension (11 females, 6 males, aged 22–61; blood pressure systolic 154±7 mmHg, diastolic 92±4 mmHg) and in 9 normotensive controls (4 males, 5 females, aged 20–71; blood pressure systolic 117±4 mmHg, diastolic 76±2 mmHg) during unrestricted sodium diet, at the 4th day of a low sodium intake (40–60 mEq/day) and at the 6th day of sodium loading (280–320 mEq/day) both after an overnight rest and after 4 h of upright posture. In the controls, plasma levels of hANP at 8:00 a.m. were lowered from 73±11 to 49±7 pg/ml during low sodium diet and increased to 128±37 pg/ml after high salt intake. Plasma ANP levels were significantly lower after 4 h of upright posture during unrestricted, low and high sodium intake. In the hypertensive group, plasma ANP levels were elevated during unrestricted diet (203±43 pg/ml), during the low sodium period (139±31 pg/ml), and after high sodium intake (267±63 pg/ml) compared to the controls. All levels were lowered by upright posture. The absolute decrease was more pronounced compared to the normotensives, the relative decline was similar in both groups. In the hypertensives, plasma ANP levels significantly correlate with systolic and diastolic blood pressure (r=0.468,r=0.448,P<0.05) and with urinary aldosterone during unrestricted diet (r=0.536,P<0.05). There was an inverse correlation between plasma ANP levels and plasma renin concentration during low and high sodium intake (r=–0.469,r=–0.496,P<0.05).These studies demonstrate raised circulating plasma ANP levels in patients with essential hypertension. The modulation of ANP by different sodium intake and by upright posture is maintained similar to the changes in plasma ANP in normotensive controls. Raised ANP levels in the hypertensives are correlated with low renin secretion and high aldosterone excretion. High ANP levels, therefore, might indicate sodium retention in essential hypertension.Abbreviation ANP
atrial natriuretic peptide
Supported by a grant from Ministerium für Wissenschaft und Forschung, NRW 相似文献
93.
Cellular dehydration induced by water deprivation or hypertonic saline injection reduces feeding in a variety of species. Normal feeding in rats is maintained during isotonic saline consumption by increasing the intake of saline compared to the usual intake of water. Hamsters do not show the spontaneous preference for isotonic saline noted in rats, even after adrenalectomy. In the present investigation, feeding by hamsters was depressed during both isotonic and hypertonic saline consumption compared to the usual feeding with water. Saline intakes did not exceed water intakes under similar conditions. When fluid intakes were elevated by prior fluid deprivation, feeding rates increased at all concentrations of saline after a delay proportional to the osmolality of the solution. Positive 24-hr sodium balances were always associated with saline consumption. Water and hypertonic saline injections reduced feeding, and the fluid loads were excreted very slowly. When hamsters were fluid deprived prior to injections, saline totally suppressed feeding, while water increased feeding compared to sham injected controls. It is concluded that cellular dehydration produces a reduction of feeding in hamsters drinking isotonic or hypertonic saline. Reduced feeding with isotonic saline consumption results from the failure of hamsters to increase their ad lib intake of that solution. The prolonged retention of both sodium and fluid after saline consumption or injection suggests that further saline intake may be inhibited by an expansion of the extracellular space. 相似文献
94.
Ogata T 《Medical molecular morphology》2005,38(4):243-250
Brush cells are widely distributed in the digestive and respiratory apparatus, but their function is still unknown. Because
brush cells (BC) are found in organs secreting NaHCO3, it was hypothesized that these cells may secrete NaHCO3. To test this possibility, rat common bile duct epithelia were examined by ultrastructural cytochemical methods for localizing
HCO3−, Cl−, and Na+ ions. All three ion precipitates were few in or on BCs of rats without stimulation. Lead carbonate precipitates, which localized
HCO3− ions by the lead nitrate-osmium method, increased markedly on the surface of the microvilli (MV) of BCs after secretin or
meal stimulation, but similar precipitates were few on the luminal surface of principal cells (PCs). Silver chloride precipitates,
which indicate the presence of Cl− ions by the silver-osmium method, increased in the apical cytoplasm and in MV of BCs after secretin or meal stimulation,
but they were few in PCs. Sodium pyroantimonate precipitates, which localize Na+ ions by the potassium pyroantimonate-osmium method, increased on the surface of the MV, along the basolateral membrane, and
in the apical cytoplasm of BCs after secretin or meal stimulation, but they were few in PCs. These results strongly suggest
that BCs may be a significant source of NaHCO3 secretion. 相似文献
95.
当归注射液对脑血栓患者花生四烯酸代谢产物和氧自由基水平的影响 总被引:4,自引:0,他引:4
目的 :了解当归注射液改善脑循环治疗脑血栓的临床效果。方法 :对 46例脑血栓形成患者应用当归注射液进行治疗 ,对比分析其治疗前后血浆前列环素 (PGI2 )、血栓烷A2 (TXA2 )及自由基水平。结果 :脑血栓形成患者TXA2 、丙二醛 (MDA)明显升高 ,超氧化物岐化酶 (SOD)明显降低。当归注射液治疗后上述改变明显减轻或恢复至正常组水平。结论 :当归注射液能有效调节花生四烯酸代谢产物和氧自由基水平 ,对治疗脑血栓效果明显。 相似文献
96.
97.
F. Jaisser J. D. Horisberger B. C. Rossier 《Pflügers Archiv : European journal of physiology》1993,425(5-6):446-452
The cortical collecting tubule (CCT) of the mammalian kidney reabsorbs sodium and potassium, processes that are mediated by Na/K-ATPase and H/K-ATPase. CCT is also an important site for proton secretion, which is driven, in part, by H/K-ATPase. Na/K-ATPase and H/K-ATPase are members of the ion-motive P-ATPase gene family. They are closely related plasma membrane proteins which consist of heterodimers. The urinary bladder of the toad Bufo marinus is the amphibian counterpart of mammalian CCT. We have previously characterized a ouabain-resistant Na/K-ATPase [see ref. 17], from TBM cells, a clonal cell line derived from the toad bladder, which expresses transepithelial sodium transport. In the present study, we report the primary sequence and functional expression of a novel subunit (
bladder=
bl) isolated from a toad bladder epithelial cell cDNA library. The deduced polypeptide is 299 amino acids in length and has a predicted molecular mass of 33 kDa. The
bl protein exhibits 35% amino acid identity to the previously characterized
1 of B. marinus Na/K-ATPase and 39% identity with
3 of B. marinus Na/K-ATPase. It shares 38% identity with the mammalian gastric H/K-ATPase and 52% with the mammalian
2 Na/K-ATPase. Northern blot analysis shows that a 1.4×103-base mRNA is expressed at a high level in bladder epithelial cells and eye and at a trace level in kidney; it is not detectable in significant amounts in the stomach, colon and small intestine. The
bl subunit can associate with the
1 subunit of B. marinus Na/K-ATPase to form a functional sodium pump in the Xenopus laevis oocyte. Our data indicate that, in addition to the known
1 and
3 isoforms, a third distinct isoform of the subunit is present in the bladder epithelium. This new isoform could be functionally associated with subunits of either Na/K- or H/K-ATPase. 相似文献
98.
Bernd Sutor Walter Zieglgänsberger 《Pflügers Archiv : European journal of physiology》1987,410(1-2):102-111
Intracellular recordings were obtained from rat neocortical neurons in vitro. The current-voltage-relationship of the neuronal membrane was investigated using current- and single-electrode-voltage-clamp techniques. Within the potential range up to 25 mV positive to the resting membrane potential (RMP: –75 to –80 mV) the steady state slope resistance increased with depolarization (i.e. steady state inward rectification in depolarizing direction). Replacement of extracellular NaCl with an equimolar amount of choline chloride resulted in the conversion of the steady state inward rectification to an outward rectification, suggesting the presence of a voltage-dependent, persistent sodium current which generated the steady state inward rectification of these neurons. Intracellularly injected outward current pulses with just subthreshold intensities elicited a transient depolarizing potential which invariably triggered the first action potential upon an increase in current strength. Single-electrode-voltage-clamp measurements reveled that this depolarizing potential was produced by a transient calcium current activated at membrane potentials 15–20 mV positive to the RMP and that this current was responsible for the time-dependent increase in the magnitude of the inward rectification in depolarizing direction in rat neocortical neurons. It may be that, together with the persistent sodium current, this calcium current regulates the excitability of these neurons via the adjustment of the action potential threshold. 相似文献
99.
Objective and design: Myeloperoxidase (MPO) and proinflammatory cytokines play an important role in the development of inflammation. These markers
are generally measured using tedious ELISA procedures. In this study, a novel technique utilizing antibody conjugated quantum
dot nanoparticles was developed to detect Myeloperoxidase, Interleukin-1α (IL-1α) and Tumor Necrosis Factor-α (TNF-α) in vivo in the dextran sodium sulfate (DSS) model of experimental colitis.
Materials and methods: Colitis was induced in animals (n = 8 animals/group) by feeding 4% DSS solution ad libitum for seven to eight days. Quantum Dots (QDs) exhibiting fluorescence at various wavelengths were conjugated to MPO, IL-1α
and TNF-α polyclonal antibodies and tested in vivo at various stages of colitis. Tissue sections obtained were imaged with confocal microscope. The image intensity obtained
from the tissue specimen was correlated with clinical activity measured as Disease Activity Index (DAI).
Results: Myeloperoxidase, IL-1α and TNF-α were visualized with quantum dots on various days of disease. The intensity of quantum dots
increased with the increase in inflammation. The increase in intensity showed an excellent correlation with the DAI based
on the clinical parameters.
Conclusion: The study demonstrated that multiple biomarkers can be detected simultaneously and their quantitative expression correlated
well with clinical disease severity. This novel technology should facilitate design of a novel optical platform for imaging
various biomarkers of inflammation, early detection of acute and chronic disease markers and inflammation-mediated cancer
markers. This detection may also facilitate determination of therapeutic success.
Received 14 March 2007; returned for revision 8 May 2007; accepted by M. Parnham 27 June 2007 相似文献
100.
Kamran Sardari 《Comparative clinical pathology》2007,16(2):97-102
Local injection of a mixture of beta-aminopropionitril fumarate (BAPN-f) and sodium hyaluronate (NaH+) together with controlled exercise were evaluated for treatment of superficial digital flexor tendon (SDFT) injuries in horses.
Fourteen mixed breed horses with subacute SDF tendon injuries in forelimbs were randomly assigned to two groups. One group
received BAPN-f (0.7 mg/ml) and the other received NaH+ (10 mg/ml) all by intratendinous injection. Controlled exercise started during the first week after intratendinous treatment
and continued for 12 weeks. Cross-sectional area (CSA) of the SDFT, diameter of the SDFT, and relative area of the lesion
(presence of CSA) were measured by ultrasonographic examination. Lesions were semiquantitatively graded for echogenicity on
a scale of 0 to 4. The lesion severity in CSA was significantly reduced by BAPN and NaH compared to those horses treated by
BAPN only (p < 0.05). Lesion echogenicity score was significantly higher in horses treated with BAPN and NaH+ at day 0 compared to horses treated with BAPN (p < 0.05). At the end of the study, lesion echogenicity score was significantly reduced in the horses treated with BAPN and
NaH+ compared to horses treated by BAPN only (p < 0.05). According to the results of the present study, a combination of BAPN-f and NaH+ has a greater beneficial effect on tendon healing and remodeling in horses, as assessed by sonographic examination, compared
to treatment with single drugs. 相似文献