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排序方式: 共有183条查询结果,搜索用时 78 毫秒
41.
42.
Association of Acanthosis nigricans with risk of diabetes mellitus and hormonal disturbances in females. 总被引:2,自引:0,他引:2
G G Lestringant A Bener P Frossard A Townsend 《International journal of gynaecology and obstetrics》2000,71(3):267-269
OBJECTIVE: To determine the association of Acanthosis nigricans, hyperinsulinemia, and hormonal levels in female subjects from the United Arab Emirates (UAE). DESIGN: Prospective study. SETTING: Tawam Teaching Hospital of Faculty of Medicine & Health Sciences. SUBJECTS: Ninety-two females (age range 16-65 years) were recruited. METHODS: Height, weight, and sitting blood pressure were recorded on 92 female subjects with A. nigricans. Fasting blood samples were obtained for measurement of uric acid, glucose, cholesterol, high-density lipoprotein- (HDL) cholesterol, and triglyceride levels. Serum levels of thyroid stimulating hormone (TSH), testosterone, luteinizing hormone (LH), follicle-stimulating hormone (FSH) and prolactin are obtained by radio-immunoassay. RESULTS: Ninety-two females with A. nigricans were enrolled in the study. Of the 92 females, 36 subjects were considered to have diabetes mellitus (DM) and 56 euglycemic subjects. The analysis showed that in cases of family history of DM, HDL-cholesterol (mmol/l) and uric acid (mmol/l) levels were higher. Overall, DM subjects had significantly higher values for hormone levels of TSH, FSH, LH, progesterone, testosterone, cortisol, prolactin, (growth hormone) GH, and ferritin. CONCLUSION: Patients with A. nigricans have a high prevalence of DM and insulin resistance in UAE. Since A. nigricans is rather prevalent in the UAE, identifying this skin lesion can help detect those subjects with a higher risk of DM and hormonal disturbances. 相似文献
43.
AB Houston MJ Brodie MR Moore GG Thompson JB Stephenson 《Archives of disease in childhood》1977,52(8):646-650
A 9-year-old boy with mental deterioration and epilepsy suffered an acute attack of hereditary coproporphyria associated with worsening of seizure control. Leucocyte coproporphyrinogen oxidase activity was undetectable in the patient during this attack, and was reduced in his mother, a latent case. The complex relationship between porphyria, epilepsy, and anticonvulsant drugs is discussed. 相似文献
44.
Human renin gene BglI dimorphism associated with hypertension in two independent populations 总被引:1,自引:0,他引:1
The renin (REN) gene is a good candidate that could underlie an individual's genetic susceptibility to human essential hypertension (EHT). We describe here a polymerase chain reaction-based assay for detection of a BglI dimorphic site located in the first intron of the REN gene. In this retrospective, case-control, association study, we investigated BglI allele and genotype distributions in 554 subjects (280 hypertensives and 274 normotensives) from the United Arab Emirates (UAE) - a genetically homogeneous ethnic population with no history of smoking or alcohol consumption - and in 485 hypercholesterolemic, US Caucasian subjects (250 hypertensives and 235 normotensives). A statistically significant association was found between alleles on which the BglI site is present [BglI(+)] and clinical diagnosis of EHT in the UAE sample group (odds ratio = 2.69, p = 0.0006), and a similar trend was observed in the US group (odds ratio = 1.97, p = 0.01). BglI(+) homozygous status was also investigated in the US group and found to be associated with elevated systolic and diastolic blood pressure values (respectively, 144.8+/-26.1 vs. 134.1+/-23.0 mm Hg, p = 0.04; and 91.0+/-12.5 vs. 82.2+/-12.7 mm Hg, p = 0.009). In conclusion, variations of the REN (or of a nearby) gene that may be in linkage disequilibrium with the REN BglI(+) marker could play a role in contributing to an increased individual's genetic susceptibility to EHT in the UAE population and amongst US hypercholesterolemic Caucasians. Such a genetic influence, which seems to show a recessive mode of inheritance, could also be implicated in raising both systolic and diastolic blood pressures. 相似文献
45.
Alteration in methyl-methanesulfonate-induced poly(ADP-ribosyl)ation by 2-butoxyethanol in Syrian hamster embryo cells 总被引:1,自引:0,他引:1
The effects of 2-butoxyethanol (2-BE) on poly(ADP-ribosyl)ation were
studied in Syrian hamster embryo (SHE) cells by measuring the cellular
concentrations of the polymer poly(ADP-ribose) (pADPr) and of NAD+, the
substrate of poly(ADP-ribose) polymerase (PARP). As biotransformation
pathways of ethylene glycol ethers involve NAD+-dehydrogenases, it was
hypothesized that 2-BE could reduce poly(ADP-ribosyl)ation by consuming
NAD+. As a result DNA repair could be altered, which would explain that
2-BE had been shown to potentiate the effects of clastogenic substances
such as methyl-methanesulfonate (MMS). In this study, the effects of 2- BE
on MMS-induced pADPr metabolism were analyzed. The results indicated that:
(i) 2-BE (5 mM) by itself did not influence significantly pADPr or NAD+
levels. (ii) 2-BE inhibited pADPr synthesis in MMS (0.2 mM)- pretreated
cells, without any change in NAD+ concentrations. (iii) MMS treatment,
which rapidly increased pADPr levels, also affected the
poly(ADP-ribosyl)ation system as a secondary effect by damaging cell
structures. Membrane permeabilization, which occurred at concentrations
>1 mM MMS, led to a dramatic leakage of cellular NAD+ resulting in a
strong reduction in pADPr levels. (iv) A bleomycin pulse (100 microM)
applied after MMS and/or 2-BE treatment confirmed that 2-BE reduced
poly(ADP-ribosyl)ation capacities of MMS-treated cells, though the glycol
ether had no effect alone. This study confirmed that the inhibition of
pADPr synthesis could be responsible for the synergistic effects of 2-BE
with genotoxic substances. The mechanism of this inhibition cannot be
explained by a lack of NAD+ at the concentrations of 2-BE tested.
相似文献
46.
While inhaled polycyclic aromatic hydrocarbons have long been suspected to
induce lung cancer in humans, their dosimetry has not been fully
elucidated. A key question is whether the critical exposure occurs during
absorption in the lungs, or if toxicants in the systemic circulation
contribute significantly to lung cancer risk. In particular, data are
needed to determine how the physical properties of inhalants affect local
dosimetry in the respiratory tract. Pyrene, a tobacco smoke component, was
selected for study because it has physical properties between those of
highly lipophilic benzo[a]pyrene and water- soluble nitrosamines. Aliquots
of 5 ng of pyrene dissolved in a phospholipid/ saline suspension were
instilled as a single-spray bolus in the posterior trachea of the dog just
anterior to the carina. For 3 h after instillation, blood was repeatedly
sampled from the azygous vein, which drains the mucosa around the point of
instillation, and from both sides of the systemic circulation. At 3 h
post-instillation, tissue samples were taken. Autoradiography was used to
determine the depth distribution of pyrene in the tracheal mucosa. The
concentration of pyrene-equivalent radioactivity in the azygous vein peaked
9 min after the instillation. At approximately 30 min after instillation, a
rapid early clearance phase shifted into a distinctly slower second
clearance phase. Rates of rapid clearance were, however, sufficiently slow
to indicate diffusion-limited absorption of pyrene in the trachea. This
finding was corroborated by high concentrations of pyrene in the epithelium
as determined by autoradiography. High epithelial concentration of pyrene
combined with a slow penetration into the circulating blood allowed
substantial first-pass metabolic conversion of pyrene in the tracheal
mucosa. A total of 13% of the instilled pyrene was retained in the tracheal
mucosa 3.2 h after instillation; of this, 29% was parent compound, 52% was
organic-extractable metabolites, 14% was water-soluble metabolites and 6%
(approximately 1% of the instilled amount) was covalently bound to tracheal
tissues. Results support the inference that lipophilic protoxicants,
because of slow, diffusion-limited absorption, are more likely than
water-soluble protoxicants to be bioactivated in the lining epithelium and,
in turn, induce first-pass toxicity at the site of entry. In addition,
limitations were identified in the use of systemically distributed
biomarkers of PAHs, such as urinary hydroxypyrene levels, as indicators of
the biologically effective dose in airway target cells.
相似文献
47.
48.
The function of cortical circuits depends critically on the balance between excitation and inhibition. This balance reflects not only the relative numbers of excitatory and inhibitory synapses but also their relative strengths. Recent studies of excitatory synapses in visual and somatosensory cortices have emphasized that synaptic strength is not a fixed quantity but is a dynamic variable that reflects recent presynaptic activity. Here, we compare the dynamics of synaptic transmission at excitatory and inhibitory synapses onto visual cortical pyramidal neurons. We find that inhibitory synapses show less overall depression than excitatory synapses and that the kinetics of recovery from depression also differ between the two classes of synapse. When excitatory and inhibitory synapses are stimulated concurrently, this differential depression produces a time- and frequency-dependent shift in the reversal potential of the composite postsynaptic current. These results indicate that the balance between excitation and inhibition can change dynamically as a function of activity. 相似文献
49.
BE Kelly FRCS GG Cooper MD FRCS JOM Mills FRCR 《International journal of clinical practice》1993,47(5):272-272
SUMMARY Although pneumatosis cystoides intestinalis (PCI) is a well-recognised condition, an individual surgeon is unlikely to encounter it often. The collected experience of two surgical units in Glasgow teaching hospitals over a 15-year period consisted of five patients.1 Surgical and radiological trainees may therefore have little or no exposure to the diagnostic difficulties this condition can cause. We report an illustrative case. 相似文献
50.