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91.
Takahata Y Koyama N Ichino S Miyamoto N Nakamichi M Soma T 《Primates; journal of primatology》2008,49(2):135-138
We used data from a 13-year field study of wild ringtailed lemurs to analyze the relationship between female rank and reproductive
parameters. In medium and small groups there were no significant differences in birth rate, infant mortality rate, and the
number of surviving infants between the female rank categories. On the other hand, in large sized groups low-ranked females
had a smaller number of surviving infants than middle-ranked females. This suggests that in large sized groups, within-group
competition lowered the values of reproductive parameters of low-ranked females. On the other hand, high and low-ranked females
of small sized groups tended to have a smaller number of surviving infants than high-ranked females of medium sized groups
and middle-ranked females of large sized groups. Between-group competition should lower the values of their reproductive parameters.
In sum, these results fit the expectation from Wrangham’s (1980) inter group feeding competition model. 相似文献
92.
Prevention of transgene flow from genetically modified crops to food crops and wild relatives is of concern in agricultural
biotechnology. We used genes derived from food crops to produce complete male sterility as a strategy for gene confinement
as well as to reduce the food purity concerns of consumers. Anther-specific promoters (A3, A6, A9, MS2, and MS5) were isolated from Brassica oleracea and B. rapa and fused to the β-glucuronidase (GUS) reporter gene and candidate genes for male sterility, including the cysteine proteases BoCysP1 and BoCP3, and negative regulatory components of phytohormonal responses involved in male development. These constructs were then introduced
into Arabidopsis thaliana. GUS analyses revealed that A3, A6, and A9 had tapetum-specific promoter activity from the anther meiocyte stage. Male sterility was confirmed in tested constructs
with protease or gibberellin insensitive (gai) genes. In particular, constructs with BoCysP1 driven by the A3 or A9 promoter most efficiently produced plants with complete male sterility. The tapetum and middle layer cells of anthers expressing
BoCysP1 were swollen and excessively vacuolated when observed in transverse section. This suggests that the ectopic expression of
cysteine protease in the meiocyte stage may inhibit programmed cell death. The gai gene also induced male sterility, although at a low frequency. This is the first report to show that plant cysteine proteases
and gai from food crops are available as a novel tool for the development of genetically engineered male-sterile plants.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
93.
Ando T Tatsuzawa F Saito N Takahashi M Tsunashima Y Numajir H Watanabe H Kokubun H Hara R Seki H Hashimoto G 《Phytochemistry》2000,54(5):495-501
In order to resolve a conflict between previous papers regarding the floral anthocyanins of red flowers of Petunia exserta, a naturally occurring species, the HPLC profile of this species was compared with that of commercial red garden petunias. Both HPLC profiles extremely superficially resemble each other in terms of relative amounts and retention times of the major anthocyanins. However, co-elution on HPLC of the mixed sample resulted in clear separation of the components. Three major anthocyanins in red petunias were determined to be cyanidin 3-sophoroside, cyanidin 3-glucoside and peonidin 3-glucoside, which exhibited similar behaviors on HPLC to delphinidin 3-glucoside. delphinidin-3-rutinoside and petunidin 3-rutinoside, respectively, the major floral anthocyanins of P. exserta. 相似文献
94.
95.
Elise A. Lamont Ping Wang Shinichiro Enomoto Klaudyna Borewicz Ahmed Abdallah Richard E. Isaacson Srinand Sreevatsan 《PloS one》2014,9(12)
Francisella tularensis, a Gram-negative bacterium and causative agent of tularemia, is categorized as a Class A select agent by the Centers for Disease Control and Prevention due to its ease of dissemination and ability to cause disease. Oropharyngeal and gastrointestinal tularemia may occur due to ingestion of contaminated food and water. Despite the concern to public health, little research is focused on F. tularensis detection in food and environmental matrices. Current diagnostics rely on host responses and amplification of F. tularensis genetic elements via Polymerase Chain Reaction; however, both tools are limited by development of an antibody response and limit of detection, respectively. During our investigation to develop an improved culture medium to aid F. tularensis diagnostics, we found enhanced F. tularensis growth using the spent culture filtrate. Addition of the spent culture filtrate allowed for increased detection of F. tularensis in mixed cultures of food and environmental matrices. Ultraperformance liquid chromatography (UPLC)/MS analysis identified several unique chemicals within the spent culture supernatant of which carnosine had a matching m/z ratio. Addition of 0.625 mg/mL of carnosine to conventional F. tularensis medium increased the growth of F. tularensis at low inoculums. In order to further enrich F. tularensis cells, we developed a DNA aptamer cocktail to physically separate F. tularensis from other bacteria present in food and environmental matrices. The combined enrichment steps resulted in a detection range of 1–106 CFU/mL (starting inoculums) in both soil and lettuce backgrounds. We propose that the two-step enrichment process may be utilized for easy field diagnostics and subtyping of suspected F. tularensis contamination as well as a tool to aid in basic research of F. tularensis ecology. 相似文献
96.
97.
Yusuke Shiromoto Satomi Kuramochi-Miyagawa Akito Daiba Shinichiro Chuma Ami Katanaya Akiko Katsumata Ken Nishimura Manami Ohtaka Mahito Nakanishi Toshinobu Nakamura Koichi Yoshinaga Noriko Asada Shota Nakamura Teruo Yasunaga Kanako Kojima-Kita Daisuke Itou Tohru Kimura Toru Nakano 《RNA (New York, N.Y.)》2013,19(6):803-810
piRNA (PIWI-interacting RNA) is a germ cell–specific small RNA in which biogenesis PIWI (P-element wimpy testis) family proteins play crucial roles. MILI (mouse Piwi-like), one of the three mouse PIWI family members, is indispensable for piRNA production, DNA methylation of retrotransposons presumably through the piRNA, and spermatogenesis. The biogenesis of piRNA has been divided into primary and secondary processing pathways; in both of these MILI is involved in mice. To analyze the molecular function of MILI in piRNA biogenesis, we utilized germline stem (GS) cells, which are derived from testicular stem cells and possess a spermatogonial phenotype. We established MILI-null GS cell lines and their revertant, MILI-rescued GS cells, by introducing the Mili gene with Sendai virus vector. Comparison of wild-type, MILI-null, and MILI-rescued GS cells revealed that GS cells were quite useful for analyzing the molecular mechanisms of piRNA production, especially the primary processing pathway. We found that glycerol-3-phosphate acyltransferase 2 (GPAT2), a mitochondrial outer membrane protein for lysophosphatidic acid, bound to MILI using the cells and that gene knockdown of GPAT2 brought about impaired piRNA production in GS cells. GPAT2 is not only one of the MILI bound proteins but also a protein essential for primary piRNA biogenesis. 相似文献
98.
Chikayuki Morimoto Shinichiro Asakawa Emiko Kuribayashi-Okuma Yoshikazu Nemoto Jinping Li 《Nucleosides, nucleotides & nucleic acids》2020,39(5):744-759
AbstractTo elucidate roles of the intestine in uric acid (UA) metabolism, we examined ABCG2 expression, tissue UA content and xanthine oxidoreductase (XOR) activity in different intestinal segments. Male SD rats were assigned to control group or oxonic acid-induced hyperuricemia (HUA) group. In control rats, ABCG2 was present both in villi and crypts in each segment. Tissue UA content and XOR activity were relatively high in duodenum and jejunum. However, in HUA rats, tissue UA content was significantly elevated in the ileum, whereas it remained unaltered in other segments. Moreover, ABCG2 expression in the HUA group was upregulated both in the villi and crypts of the ileum. These data indicate that the ileum may play an important role in the extra-renal UA excretion. 相似文献
99.
Lida Sanchez Satoshi D. Ohdachi Atsushi Kawahara Lazaro M. Echenique‐Diaz Shinichiro Maruyama Masakado Kawata 《Ecology and evolution》2019,9(5):2629-2639
Shrew species have been proposed to utilize an echo‐based orientation system to obtain additional acoustic information while surveying their environments. This system has been supported by changes in vocal emission rates when shrews encounter different habitats of varying complexity, although detailed acoustic features in this system have not been reported. In this study, behavioral experiments were conducted using the long‐clawed shrew (Sorex unguiculatus) to assess this orientation system. Three experimental conditions were set, two of which contained obstacles. Short‐click, noisy, and different types of tonal calls in the audible‐to‐ultrasonic frequency range were recorded under all experimental conditions. The results indicated that shrews emit calls more frequently when they are facing obstacles or exploring the experimental environment. Shrews emitted clicks and several different types of tonal calls while exploring, and modified the use of different types of calls for varying behavior. Furthermore, shrews modified the dominant frequency and duration of squeak calls for different types of obstacles, that is, plants and acrylic barriers. The vocalizations emitted at short inter‐pulse intervals could not be observed when shrews approached these obstacles. These results are consistent with the echo‐based orientation hypothesis according to which shrews use a simple echo‐orientation system to obtain information from their surrounding environments, although further studies are needed to confirm this hypothesis. 相似文献
100.
Masamitsu Konno Atsushi Hamabe Shinichiro Hasegawa Hisataka Ogawa Takahito Fukusumi Shimpei Nishikawa Katsuya Ohta Yoshihiro Kano Miyuki Ozaki Yuko Noguchi Daisuke Sakai Toshihiro Kudoh Koichi Kawamoto Hidetoshi Eguchi Taroh Satoh Masahiro Tanemura Hiroaki Nagano Yuichiro Doki Masaki Mori Hideshi Ishii 《Development, growth & differentiation》2013,55(3):309-318
Adipose tissue‐derived mesenchymal stem cells (ADSCs) are multipotent and can differentiate into various cell types, including osteocytes, adipocytes, neural cells, vascular endothelial cells, cardiomyocytes, pancreatic β‐cells, and hepatocytes. Compared with the extraction of other stem cells such as bone marrow‐derived mesenchymal stem cells (BMSCs), that of ADSCs requires minimally invasive techniques. In the field of regenerative medicine, the use of autologous cells is preferable to embryonic stem cells or induced pluripotent stem cells. Therefore, ADSCs are a useful resource for drug screening and regenerative medicine. Here we present the methods and mechanisms underlying the induction of multilineage cells from ADSCs. 相似文献