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21.
We have found that atrial natriuretic factor (ANF) has a profound effect on testicular cells in altering intracellular cyclic nucleotide levels as well as progesterone secretion. Using clonal cultured Leydig tumor cells we found that 1 X 10(-8)M ANF caused a two thousand-fold elevation in the accumulation of cellular cGMP and inhibited cAMP in treated cells by more than 90% as compared to the controls. ANF (1 X 10(-8)M) also significantly inhibited gonadotropin-stimulated accumulation of cAMP in response to bovine luteinizing hormone (bLH) or human chorionic gonadotropin (hCG). Gonadotropin-stimulated progesterone secretion was inhibited by ANF (1 X 10(-10) - 1 X 10(-9)M) in these cultured Leydig tumor cells. Approximately 50% inhibition of progesterone secretion was observed at the peptide concentration of 1 X 10(-9) M.  相似文献   
22.
Summary A new variety of Gloeocapsa, G. crepidinum Thuret var. ghazipurensis n. var., has been isolated from enrichment cultures of paddy field soils of Ghazipur, Uttar Pradesh, India. The alga has been studied in detail. The form is especially interesting since it showed certain growth-stages recorded in G. alpina Naeg.The authors are thankful to Rev. Dr. H. Santapau for rendering the Latin diagnosis of the new variety.  相似文献   
23.
Copper uptake by free and immobilized cyanobacterium   总被引:1,自引:0,他引:1  
Abstract Copper uptake in free and immobilized cells of the cyanobacterium Nostoc calcicola has been examined. The immobilized cells invariably maintained a higher profile of Cu intake rate (12.7 nmol mg−1 protein min−1) over the free cells (6.0 nmol mg−1 protein min−1). The total Cu uptake in immobilized cells was almost two and a half-times more than their free cell counterpart under identical experimental conditions. Also, the immobilized cells showed a stronger positive correlation between Cu adsorption and uptake. The results have been discussed in terms of improved metabolic efficiency of immobilized cells.  相似文献   
24.
Ishwar AK  Pandey JN 《Theriogenology》1990,34(5):1015-1024
Thirty-six Black Bengal female goats were in the study. They were divided into three groups of 12 goats each. Group I served as the control, Group II was treated with progesterone, Group III was administered prostaglandin F2alpha. There was 100% estrus synchronization in the PGF2alpha treated group and 90% in the progesterone treated group. The total number of kids produced in the PGF2 alpha treated group was 15 followed by 12 in the progesterone - treated group and 6 in the control group. The gestation length was found to be similar in all three groups.  相似文献   
25.
Summary Solid state fermentation system was used to cultivate Brevibacterium sp. on sugar cane bagasse impregnated with a medium containing glucose, urea, mineral salts and vitamins for producing L-glutamic acid. Maximum yields (80 mg glutamic acid per g dry bagasse with biomass and substrate - mg/gds) were obtained when bagasse of mixed particle size was moistened at 85–90 % mositure level with the medium containing 10 % glucose. This is the first report on the cultivation of Brevibacterium sp. in solid cultures for production of glutamic acid.  相似文献   
26.
Indigenous Indian groups comprise approximately 20% of Ecuador's population, the third largest percentage in all of Central or South America, yet immunogenetic data on these groups are lacking in the literature. In the course of population migration studies, sera collected from 65 Ecuadorians living in the northern province of Esmeraldas were typed for six GM and two KM markers. The study population consisted of 47 Cayapa Indians and 18 blacks of African origin, descendants of slaves imported into the area during the seventeenth century. The Cayapa demonstrated three GM phenotypes, two of which are common to other South American Indian tribes. The frequency of KM1 positive Cayapa Indians (63%) is similar to other South American Indian tribes, but is significantly greater than the Huaorani of eastern Ecuador (2%), the only other Ecuadorian Indian group for whom limited immunoglobulin allotype data are available ( 2=35.8, P<0.0001).  相似文献   
27.
Cycling of six mineral elements (N, P, K, Na, Ca and Mg) was studied in a humid subtropical grassland at Cherrapunji, north-eastern India during 1988-1989. Elemental concentrations in the shoot of four dominant grass species,viz., Arundinella khaseana, Chrysopogon gryllus, Eragrostiella leioptera andEulalia trispicata were very low, and none of the species appears suitable for fodder use. Among different vegetation compartments, live root was the largest reservoir of all the nutrients (except Ca) followed by live shoot, dead shoot, litter and dead root. For Ca, live shoot was the major storage compartment. The total annual uptake (kg ha-1) was 137.3, 10.4, 51.1, 5.5, 8.7 and 18.2 for N, P, K, Na, Ca and Mg, respectively. In an annual cycle 98% N, 77% P, 49% K, 109% Na, 87% Ca and 65% Mg returned to the soil through litter and belowground detritus. A major portion of N, P and Na was recycled through the belowground system, whereas nearly half of K, Ca and Mg was recycled through the shoot system. Precipitation acts as the source of N and P input, but at the same time causes loss of cations.  相似文献   
28.
Rare earth metals play a conspicuous role in magnetic resonance imaging (MRI) for detecting cancerous cells. The alkali metal potassium is a neurotransmitter in the sodium–potassium pump in biomedical sciences. This unique property of rare earth metals and potassium drew our attention to carry forward this study. Therefore, in this work, previously synthesized potassium (K) complexes formed by the reflux of 4-N,N-dimethylaminobenzoic acid (DBA) and potassium hydroxide in methanol, and named [(μ2–4-N,N-dimethylaminobenzoate-κO)(μ2–4-N,N-dimethylaminobenzoic acid-κO)(4-N,N-dimethylaminobenzoic acid-κO) potassium(I) coordination polymer)] were treated hydrothermally with La2O3 nanomaterials to obtain a nanohybrid La2O3/K-complex. After that, the K-complex was analyzed using single-crystal X-ray diffraction and 1H and 13C NMR spectroscopy. In addition, the structural and morphological properties of the as-prepared nanostructured La2O3/K-complex were also characterized, which involved an investigation using X-ray diffraction (XRD)spectroscopy, Fourier transform infrared (FTIR) spectroscopy, atomic force spectroscopy (AFM), transmission electron microscopy (TEM), and energy dispersive X-ray (EDX) analysis. After this, the electrochemical redox behaviour of the synthesized nanohybrid material was studied using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Therefore, the results from these studies revealed that the as-prepared material was a La2O3/K-complex that has a promising future role in sensing various analytes, as it showed effective electrocatalytic behaviour.  相似文献   
29.
Pandey  Roma  Sharma  Ashish  Sood  Hemant  Chauhan  Rajinder Singh 《Protoplasma》2023,260(2):453-466
Protoplasma - Picrorhiza kurroa Royle ex Benth is a valuable medicinal herb of North-Western Himalayas due to presence of two major bioactive compounds, picroside-I and picroside-II used in the...  相似文献   
30.
Nitrate uptake and nitrite efflux patterns in Nostoc MAC showed a rapid phase followed by their saturation. Nitrite efflux was maximum in nitrate medium whereas the cells incubated in N2 and NH 4 + media exhibited a decreased nitrite efflux activity. The simultaneous presence of NH 4 + and nitrate significantly decreased nitrite efflux. L-Methionine-Dl-sulphoximine (MSX) prevented inhibition of nitrite efflux by NH 4 + . In the dark there was negligible nitrite efflux, whereas illumination increased the rate of nitrite efflux significantly. The nitrite efflux system was maximally operative at pH 8.0, 30°C and a photon fluence rate of 50 mol m-2. s-1. These results confirm that (i) the nitrite efflux system in Nostoc MAC is dependent upon nitrate uptake and assimilation and is repressible by NH 4 + ; (ii) NH 4 + itself is not the actual repressor of nitrite efflux; a product of NH 4 + assimilation via glutamine synthetase (GS) is required for repression to occur; (iii) the catalytic function of GS does not appear to be involved in nitrate assimilation-dependent nitrite efflux, and (iv) the optimum pH, temperature and illumination for maximum nitrite efflux were found to be 8.0, 30°C and 50mol m-2. s respectively.B.B. Singh, P.K. Pandey and P.S. Bisen are with the Department of Microbiology, Barkatullah University. Bhopal 462026, India. S.Singh is with the Department of Microbiology, School of Life Sciences, North Maharashtra University, Jalgaon, India  相似文献   
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