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431.
Hu et al. (1996) and Laporte et al. (1997) recently proposed a novel contiguous gene syndrome of myotubular myopathy, abnormal male genital development and deletion in Xq28. We studied a family where two male infants, both deceased, had myotubular myopathy and intersexual genitalia. Using FISH we detected in the mother a hemizygous deletion including the myotubularin gene MTM1 and F18 (a gene of yet unknown function). DNA studies with STR-markers (short tandem repeats) within and flanking the deleted segment confirmed the deletion in the family and were used for prenatal diagnosis. Our findings confirm the existence of this novel contiguous gene syndrome and support that the deletion of the F18 gene, or a neighboring gene, may cause ambiguous genitalia or severe hypospadias in males. The mother had low muscle power and marked menstrual irregularities which may indicate that she is a manifesting carrier and that the deletion may include a gene (F18 or other) for gonadal function in females. 相似文献
432.
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434.
The postnatal development of the gerbil vagina has been investigated and special attention has been paid to the luminal surface epithelium structures. Different types of microvilli and solitary cilia are discussed. 相似文献
435.
A series of 31 patients with various degrees of chronic obstructive pulmonary disease underwent right heart catheterization using flow-directed thermodilution catheters. Both rest and supine exercise values were obtained. The patients were divided into two groups on the basis of their reduction in forced expiratory volume in 1 s (FEV1). In patients with FEV1 values of greater than or equal to 1,300 ml (group 1), the arterial oxygen partial pressure (PaO2) did not significantly change with exercise, while in patients with FEV1 of less than or equal to 1,200 ml (group 2) PaO2 significantly (p less than 0.05) fell in response to exercise. In group 2, a significant increase of total pulmonary resistance (TPR) with exercise was found (p less than 0.01). Pulmonary vascular resistance (PVR) remained unchanged in both subgroups. It is suggested that the value of PVR for subgroup 2 is artificially low because an important variable, namely pulmonary artery wedge pressure, is influenced by alveolar pressure in patients with an uneven distribution of perfusion and ventilation at pulmonary venous pressures lower than alveolar pressure. The steeper slope of the pressure-flow relationship in these patients is probably due to an increased vascular tone caused by chronic hypoxia at rest and further fall of PaO2 and rise of arterial CO2 partial pressure in response to exercise. 相似文献
436.
437.
Comparison of class I (H-2) gene sequences. Derivation of unique probes for members of this multigene family 总被引:15,自引:0,他引:15
The genes for the classical transplantation antigens are unique in that they belong to a multigene family of which each member is represented by a large number of alleles. Since all of these genes are highly related in sequence, it has been difficult to study the expression of individual members of this complex gene family. Based upon our initial suggestion that the 3' noncoding regions of these genes may be useful in identifying mRNA molecules transcribed from different loci, we have compared a large number of sequences from different inbred mouse strains and have been able to assign each of these sequences without ambiguity into distinct allelic series. Such accurate assignment has afforded the opportunity to compare the coding regions of these highly homologous genes and has led to the identification of sequences which are apparently unique to specific genes in the family. Synthetic oligonucleotides corresponding to each of the locus-specific unique regions have been used successfully to type a panel of cDNA sequences, as well as to quantitate the relative amounts of mRNA transcribed from distinct loci. The availability of these specific coding probes will allow the analysis of individual genes and their specific expression without interference from other highly homologous sequences in this multigene family. 相似文献
438.
439.
P K Seth C Meissner W Kress S Seth R Warneke S Purmann E Schwinger 《Human heredity》1989,39(5):282-287
Four polymorphic sites of the short arm of the X chromosome were studied in two racial groups from India, the Assamese and the Malayalee. Since the allelic frequencies of the two groups did not differ markedly from each other, the data from the two populations were pooled. The frequency of the A2 allele was 0.57 for the L1.28 probe, 0.20 for the RC8 probe, 0.28 for the pD2 probe and 0.11 for the L754 probe. The A3 allelic fragment of the RC8 probe was not found among 67 Indians, and in one Assamese woman an additional 7.0-kilobase fragment was found. The differences between the Indian population and other ethnic groups were analyzed. 相似文献
440.
Chantal Kress Sandrine Vandormael-Pournin Patricia Baldacci Michel Cohen-Tannoudji Charles Babinet 《Mammalian genome》1998,9(12):998-1001
The inbred mouse strain DDK carries a conditional early embryonic lethal mutation that is manifested when DDK females are
crossed to males of other inbred strains but not in the corresponding reciprocal crosses. It has been shown that embryonic
lethality could be assigned to a single genetic locus called Ovum mutant (Om), on Chromosome (Chr) 11 near Syca 1. In the course of our study of the molecular mechanisms underlying the embryonic lethality, we were interested in deriving
an embryonic stem cell bearing the Om mutation in the homozygous state (Om
d
/Om
d
). However, it turned out that DDK is nonpermissive for ES cell establishment, with a standard protocol. Here we show that
permissiveness could be obtained using Om
d
/Om
d
blastocysts with a 75% 129/Sv and 25% DDK genetic background. Several germline-competent Om
d
/Om
d
ES cell lines have been derived from blastocysts of this genotype. Such a scenario could be extended to the generation of
ES cell lines bearing any mutation present in an otherwise nonpermissive mouse strain.
Received: 2 June 1998 / Accepted: 18 August 1998 相似文献