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101.
102.
本文报道了具有降血糖作用的人参多肽基因的设计及用固相亚磷酰胺法的合成。再以质粒pUC19作为克隆载体,以大肠杆菌JM101为受体菌,克隆了人参多肽基因,并成功地获得了克隆菌株。 相似文献
103.
T. C. Hsu Edward J. Shillitoe Lorraine M. Cherry Qi Lin Stimson P. Schantz Cynthia Furlong 《In vitro cellular & developmental biology. Plant》1990,26(1):80-84
Summary Forty lymphoblastoid (lymphoid) lines were established from 42 volunteer blood donors, including healthy individuals and patients
with head and neck carcinomas. Each peripheral blood sample was split into two portions, one for the establishment of a lymphoid
line and the other for short-term culture, which was used to estimate bleomycin sensitivity by cytogenetic procedures. Twenty
lymphoid lines were selected at random to compare bleomycin sensitivity with data obtained from short-term lymphocyte cultures.
In each set, bleomycin sensitivity of lymphoid cells was similar to that of the lymphocytes. The lymphoid lines, which can
be propagated for an unlimited supply of relatively homogeneous cellular material, will be useful for a variety of future
investigations.
This investigation was supported by grants from the John S. Dunn Foundation, Houston, TX, the Esther Knispel Fund administered
by The University of Texas M. D. Anderson Cancer Center, Houston, TX, and Department of Health and Human Services PHS grant
DE 07007. 相似文献
104.
Stabilization of a HemA-LacZ hybrid protein against proteolysis during carbon starvation in atp mutants of Salmonella typhimurium. 总被引:2,自引:2,他引:0
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Transposon insertions that stabilize the beta-galactosidase activity of a HemA-LacZ hybrid protein following carbon starvation were mapped to the atp operon of Salmonella typhimurium. This effect is similar to that seen with nuo mutants defective in the energy-conserving type I NADH dehydrogenase. Insertions in several other genes, including such highly pleiotropic mutants as rpoS, polA, and hfq, were isolated with the same phenotypic screen, but they do not affect the beta-galactosidase activity of HemA-LacZ. All of these mutants act indirectly to alter the colony color of many different fusion strains on indicator plates. 相似文献
105.
106.
A Bacillus subtilis gene for malate dehydrogenase (citH) was found downstream of genes for citrate synthase and isocitrate dehydrogenase. Disruption of citH caused partial auxotrophy for aspartate and a requirement for aspartate during sporulation. In the absence of aspartate, citH mutant cells were blocked at a late stage of spore formation. 相似文献
107.
108.
Toshihiko Fujita Daiji Kitagawa Yusaku Okuyama Yasutoshi Jin Yoshio Ishito Tadashi Inada 《Environmental Biology of Fishes》1996,46(4):351-364
Synopsis Fish assemblages at an artificial reef site, a natural reef site and a sandy-mud bottom site, on the shelf (depth 130 m) off Iwate Prefecture, northern Japan, were surveyed by using a bottom trammel net from May 1987 to March 1993. A total of 12 173 fishes of 48 species were recorded. Physiculus maximowiczi was dominant and comprised 69% of the total numerical abundance. Total fish number was lowest in March at all the 3 sites when P. maximowiczi migrated to deeper and warmer waters. Assemblage equitability and species diversity also varied seasonally in accordance with the abundance fluctuation of P. maximowiczi. P. maximowiczi, Alcichthys alcicornis and Hexagrammos otakii were more abundant at the artificial reef and natural reef sites, while Dexistes rikuzenius and Hemitripterus villosus were more abundant at the sandy-mud bottom site; total fish abundance was largest at the artificial reef site mainly due to the large number of P. maximowiczi. Species richness was similar among sites, but equitability, and consequently species diversity, was lowest at the artificial reef site. The main effect of the artificial reef seemed the attraction of P. maximowiczi from nearby bottoms, especially from natural rocky reefs; its large abundance determined the structure of the artificial reef fish community. 相似文献
109.
J.Y. Roh H.W. Park B.R. Jin H.S. Kim Y.M. Yu S.K. Kang 《Letters in applied microbiology》1996,23(4):249-252
J.Y. ROH, H.W. PARK, B.R. JIN, H.S. KIM, Y.M. YU AND S.K. KANG. 1996. Four Bacillus thuringiensis isolates from soil samples produced parasporal inclusions which were non-toxic to insects. The isolates were named B. thuringiensis NTB-1, NTB-2, NTB-3 and NTB-4. The parasporal inclusions were shown to be ovoid by phase contrast and scanning electron microscopy. The serotypes of the four isolates were determined by agglutination using 33 antisera; NTB-1 and NTB-4 seemed to be subsp. isruelensis ,and NTB-2 seemed to be subsp. pondzcheriensis . NTB-3 did not react with the 33 antisera. However, comparison of parasporal protein and plasmid DNA patterns of the four isolates with those of 15 known non-toxic B. thuringiensis strains demonstrated that the four isolates are novel. 相似文献
110.
Acetylation dramatically effects both the solution properties and the metal induced precipitation of alginates. The presence of acetyl groups on both bacterial and seaweed alginate polymers marginally increased the weight average molecular weight (Mw) of each polymer by 7% and 11%, respectively. Acetylated bacterial alginate showed a significant increase in solution viscosity compared to its deacetylated counterpart. However microbial acetylation of seaweed alginate did not change its solution viscosity. Acetylation altered the calcium induced precipitation of both alginates. The presence of acetyl groups decreased the ability of each polymer to bind with calcium but increased their ability to bind with ferric Ion (Fe3+). By controlling the degree of acetylation on the alginate chains, it was possible to modify solution viscosity and cation induced precipitation of these polymers. 相似文献