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排序方式: 共有786条查询结果,搜索用时 15 毫秒
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K J Franklin R J Buist J den Hartog G A McRae D P Spencer 《International journal of hyperthermia》1992,8(2):253-262
A temperature probe based on the magnetic resonance properties of an encapsulated liquid crystal has been investigated. Large changes in magnetic resonance signals occur as the liquid crystal undergoes a phase transition from an anisotropic (nematic) state to the isotropic liquid. The low latent heat of such phase transitions allows for rapid phase changes during a hyperthermia treatment. Transition temperatures can be tailored by adding suitable compounds such as analogues of the liquid crystal or various solvents. Encapsulation is required to maintain the integrity of the liquid crystal, particularly for applications in vivo. Results of preliminary studies designed to demonstrate the technical feasibility of the concept are presented. 相似文献
5.
A S Buist W M Vollmer L R Johnson L E McCamant 《The American review of respiratory disease》1988,137(2):293-301
We report here the results of a 9- to 11-yr follow-up of 2 cohorts in which spirometry and the single-breath N2 test were used throughout the follow-up period to determine the usefulness of the single-breath N2 test in identifying the smoker who is experiencing a rapid decline in FEV1 and is therefore likely to be at risk of developing chronic airflow limitation. The analyses are based on 734 subjects tested from 3 to 5 times over the follow-up period; 82 smokers developed an abnormal FEV1 during the follow-up period. Of these, 71 (87%) had had an abnormal single-breath N2 test at some time prior to the FEV1 becoming abnormal. Of the single-breath N2 test variables, CC/TLC was the only one significantly associated with the rate of decline of FEV1 in both cohorts once adjustments were made for age, sex, height, and smoking. We conclude that the single-breath N2 test can be useful in identifying the smoker who is at risk of developing chronic airflow limitation. However, its usefulness is diminished by the high proportion of smokers who have mild functional abnormalities but do not progress to develop chronic airflow limitation. We also find that the single-breath N2 test does not appear to have a useful predictive value in nonsmokers. 相似文献
6.
Ghosh D; Stewart DR; Nayak NR; Lasley BL; Overstreet JW; Hendrickx AG; Sengupta J 《Human reproduction (Oxford, England)》1997,12(5):914-920
The present study was undertaken to assess the temporal association between
the profiles of serum concentrations of oestradiol-17beta, progesterone,
chorionic gonadotrophin (CG) and relaxin in pregnancies established
naturally, and after embryo transfer, as well as in failed pregnancies in
rhesus monkeys. In naturally mated cycles (group 1) a conception rate of
75% was obtained. In group 1, the mean day of CG detection in serum was
11.5 +/- 1.9 day post-ovulation, and for relaxin, 9.0 +/- 2.5 day
post-ovulation. In group 2, embryo transfer to synchronous, non-mated
surrogate recipients was performed; seven embryo transfer cycles yielded
three pregnancies which were allowed to continue to term and normal infants
were delivered. In embryo transfer cycles the mean day of CG detection was
14.8 +/- 1.8 day post- ovulation, and for relaxin, 11.4 +/- 2.6 day
post-ovulation. A delay of about 3 days was observed in the appearance in
circulation of CG (P < 0.05) and also of relaxin (P < 0.05) between
natural mated and embryo transfer conception cycles. Significant
differences (P < 0.05 for progesterone and P < 0.03 for oestradiol)
were obtained for the areas under the curves for progesterone and
oestradiol between days 12 and 16 in conception cycles compared with failed
pregnancies. These data provide the first observation of the normal
hormonal signals associated with maternal recognition of transferred
embryos during the peri- implantation period, and suggest that the use of
such an experimental primate embryo transfer model may help to elucidate
components of maternal and embryonic signal-response mechanisms during
embryo implantation.
相似文献
7.
A Vos J W Oosterhuis B de Jong S M Castedo H Hollema J Buist J G Aalders 《Cancer Genetics and Cytogenetics》1990,44(2):223-228
We karyotyped a metastasis composed of pure yolk sac tumor derived from a primary ovarian germ cell tumor with two components: a dermoid cyst [DNA index (DI) 1.0] and a pure yolk sac tumor (DI 1.88). The metastatic yolk sac tumor had a hypertriploid karyotype and a DI of 1.78 and lacked the germ cell tumor marker i(12p). The absence of this marker in a metastasis from a tumor with a dermoid cyst component might be indicative for a pathogenesis of the yolk sac tumor similar to that of a dermoid cyst and different from that of dysgerminoma. 相似文献
8.
[31P]-Nuclear magnetic resonance (NMR) in vivo spectra ofEchinococcus multilocularis cysts growing subcutaneously inMeriones unguiculatus showed prominent signals due to phosphomonoesters (PME), phosphodiesters (PDE), inorganic phosphate (Pi) and the , and phosphate groups of adenosine triphosphate (ATP). The internal pH of the parasite cysts was 6.7–6.8. The31P spectra of extracts of these subcutaneous cysts showed peaks identified as glucose-6-phosphate (Glu-6-P), glycerol-3-phosphate (Gly-3-P), phosphorylethanolamine (PE), adenosine-5-monophosphate (5-AMP), nicotinamide adenine dinucleotide phosphate (NADP), phosphorylcholine (PC), Pi, glycerolphosphorylethanolamine (GPE), glycerolphosphorylcholine (GPC), phosphoenolpyruvate (PEP), adenosine diphosphate (ADP), ATP and diphosphodiesters (DPDE). These metabolites were also detected at comparable concentrations in the extracts of intraperitoneally grown cysts. In addition, significantly more phosphocreatine (PCr), probably of host origin, was detected in the subcutaneous cysts than in the intraperitoneal cysts. [1H]-NMR spectra of cyst extracts revealed that parasites grown in the abdominal cavity contained significantly less glucose but significantly more succinate, acetate, alanine and -hydroxybutyrate. Glycogen, creatine, glycine, taurine, betaine, cholines and lactate were present at similar concentrations in cyst material from both locations. 相似文献
9.
de Groot J Kruijt L Scholten JW Boersma WJ Buist WG Engel B van Reenen CG 《Immunology》2005,115(4):495-505
The capacity of farm animals to produce cytokines could be an important determinant of robustness and health. From research in rodents and humans it appears that the production and the balance of T helper 1 (Th1) and T helper 2 (Th2)-type cytokines influences susceptibility to autoimmune and infectious diseases. It is known that pigs show a large variation in many immune response parameters. So far the extent of individual variation in the production of Th1- and Th2-type cytokines in commercial outbred pigs has not been reported. In the current experiment we determined mRNA expression, as well as protein production of cytokines in 32 pigs from eight litters. From each litter two male and two female pigs were tested at 2, 5 and 8 weeks of age. Two Th1-type cytokines, interleukin (IL)-2 and interferon (IFN)-gamma, and two Th2-type cytokines, IL-4 and IL-10, were measured after phytohaemagglutinin (PHA)-stimulation of blood mononuclear cells. Cytokine production and the Th1/Th2-ratio were highly variable. The variation in cytokine protein production was moderately consistent across ages, i.e. pigs that produced high levels of cytokine at 2 weeks of age tended to do so as well at 5 and 8 weeks of age. Cytokine production tended to increase with age, and gilts and boars differed in their IL-2/IL-4 ratio. Unexpectedly, age, gender and litter effects often differed for mRNA and protein production data. We hypothesize that cytokine production is a consistent trait in pigs, especially at the protein production level. Future investigations in more animals and across a wider age range are necessary. 相似文献
10.
The role of size, sequence and haplotype in the stability of FRAXA and FRAXE alleles during transmission 总被引:2,自引:5,他引:2
Murray A; Macpherson JN; Pound MC; Sharrock A; Youings SA; Dennis NR; McKechnie N; Linehan P; Morton NE; Jacobs PA 《Human molecular genetics》1997,6(2):173-184
Factors involved in the stability of trinucleotide repeats during
transmission were studied in 139 families in which a full mutation,
premutation or intermediate allele at either FRAXA or FRAXE was
segregating. The transmission of alleles at FRAXA, FRAXE and four
microsatellite loci were recorded for all individuals. Instability within
the minimal and common ranges (0-40 repeats for FRAXA, 0-30 repeats for
FRAXE) was extremely rare; only one example was observed, an increased in
size at FRAXA from 29 to 39 repeats. Four FRAXA and three FRAXE alleles in
the intermediate range (41-60) repeats for FRAXA, 31-60 for FRAXE) were
unstably transmitted. Instability was more frequent for FRAXA intermediate
alleles that had a tract of pure CGG greater than 37 although instability
only occurred in two of 13 such transmissions: the changes observed were
limited to only one or two repeats. Premutation FRAXA alleles over 100
repeats expanded to a full mutation during female transmission in 100% of
cases, in agreement with other published series. There was no clear
correlation between haplotype and probability of expansion of FRAXA
premutations. Instability at FRAXA or FRAXE was more often observed in
conjunction with a second instability at an independent locus suggesting
genomic instability as a possible mechanism by which at least some FRAXA
and FRAXE mutations arise.
相似文献