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31.
Quartz grains in granitic rocks usually have blue cathodoluminescence (CL). Within the blue-luminescing grains, there are often red-luminescing domains which are frequently impossible to detect without CL contrast. This finding suggests that the red-luminescing quartz is sealing preexisting mnicrocracks. The presence of these now-healed microcracks has important implications with respect to the role of pore fluid pressure and fluid transfer in metamorphism, the origih of granites, longperiod crustal deformation, earthquake mechanics, physical properties of rocks, and deep-seated geothermal energy.  相似文献   
32.
轮台属于大陆型气候,气候干燥,昼夜温差大,很适宜杏树的种植。但是该县杏树生产目前还是传统的粗放经营方式,产量低,品质差,效益低,严重影响其发展进程。因此,只有因地制宜的建立杏树生产基地,在进行集约化的土水肥管理和树体管理措施才能更好地适应市场需求,生产产量和品质较高的,适应国内外市场的优质商品果。在轮台小白杏的生物学特性,生长地环境进一步调查了解的基础上,对小白杏生产过程中采取的主要技术措施进行了分析和总结,结合小白杏的产量和品质,提出了比较适宜的高产并优质果生产的栽培管理的配套技术措施。认为在小白杏生产过程中只要采取规范化并集约化的栽培管理措施,可以提高产量和品质,达到提高经济效益的栽培目的。  相似文献   
33.
Polyphenol oxidase (PPO) of cauliflower was purified to 282-fold with a recovery rate of 8.1%, using phloroglucinol as a substrate. The enzyme appeared as a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The estimated molecular weight of the enzyme was 60 and 54 kDa by SDS-PAGE and gel filtration, respectively. The purified enzyme, called phloroglucinol oxidase (PhO), oxidized phloroglucinol (K(m) = 3.3 mM) and phloroglucinolcarboxylic acid. The enzyme also had peroxidase (POD) activity. At the final step, the activity of purified cauliflower POD was 110-fold with a recovery rate of 3.2%. The PhO and POD showed the highest activity at pH 8.0 and 4.0 and were stable in the pH range of 3.0-11.0 and 5.0-8.0 at 5 °C for 20 h, respectively. The optimum temperature was 55 °C for PhO and 20 °C for POD. The most effective inhibitor for PhO was sodium diethyldithiocarbamate at 10 mM (IC(50) = 0.64 and K(i) = 0.15 mM), and the most effective inhibitor for POD was potassium cyanide at 1.0 mM (IC(50) = 0.03 and K(i) = 29 μM).  相似文献   
34.

In South Asia, an increasing population and frequent droughts have been significant factors deeply affecting water deficits in the region. In this study, recent drought conditions were evaluated by calculating the standardized precipitation index (SPI) for the period of 1991–2006, based on past data during the period from 1961 to 1990. In addition, the Thornthwaite equation was used to compute monthly potential evapotranspiration for the entire area of Indonesia. The APHRODITE data set was utilized for precipitation and temperature. Monthly rainfall data from April to September for 30 years (1961–1990) were used to obtain the gamma function for the computation of SPI values. Calculated probability of SPI for which values were < − 2 during the period from 1991 to 2006 was used to evaluate recent Indonesian drought conditions. Regarding potential soil water deficits, under the very simple assumption that the root zone is 30 cm, soil porosity is 0.4, and field capacity is 80% of soil porosity, the critical threshold of soil water deficit was set as − 96 mm. Frequency of potential water deficits < − 96 mm was counted during 1991–2006. The results of the SPI in Indonesia indicate that most parts of Indonesia have encountered severe and extreme drought for the period 1991–2006. Based on SPI interpretation, Borneo Island and West Papua are the islands that encountered the most extreme drought during the dry seasons. Borneo Island seems to have encountered extreme drought at the beginning and the middle of the dry seasons (April, May, and July). On the other hand, based on the Thornthwaite interpretation, Java and Bali Islands, and especially in Central Java and East Java, seem to have encountered the greatest soil water deficit at the middle and the end of the dry seasons (May, June, July, and September).

  相似文献   
35.
New generation wound dressings require the criteria that both bioactive and conventional wound dressing materials can recompense the fundamental properties like defense of wound from microbial invasion, dehydration during the wound care duration and mimic the healing process. In this study, functional double-layered nanofibrous composite membranes were fabricated via electrospinning method. The matrices consist of a sheet of ampicillin loaded poly(2-hydroxylethyl methacrylate/polyacrylic acid (pHEMA/pAA) nanofibers on the upper side (first layer: pH sensitive antibacterial barrier) and a sheet of poly(ε-caprolactone) (PCL)/gelatin nanofibers (second layer: bioactive part). Ampicillin was successfully incorporated to double-layered matrices which greatly changed the mechanical properties, biodegradability and water uptake ratios (up to 4 fold higher values). The success of the antimicrobial activity of ampicillin on Staphylococcus aureus and Escherichia coli was indicated by the inhibition zone test. pH sensitivity was confirmed by the swelling and ampicillin release studies by shifting pH value to basic environment. Thus, double-layered pHEMA-pAA nanofibers suggest as a potential wound dressing material for its pH sensitive drug delivery ability and its bioactive part.  相似文献   
36.
Six Newcastle disease virus (NDV) isolates were obtained from disease outbreaks on different poultry farms in the Sudan between 1988 and 1991. The pathogenic properties of these isolates were studied in comparison to those of strain Herts 33/56. All the isolates were similar in that they killed chicken embryos quickly, in mean death time (MDT) and embryo lethal dose 50 per cent (ELD50), had higher intracerebral pathogenicity indices (ICPI), and produced viscerotropic lesions in the infected chickens. The field isolates had the characteristics of the velogenic viscerotopic strains of NDV. The pathogenesis of infection caused by one of the isolates was studied. The virus was first detected in different organs and in oral and cloacal swabs on the third day after infection.  相似文献   
37.
Apoptosis seems to play an important role in the pathogenic profile of bovine herpesvirus 1 (BHV-1) infection. Nitric oxide (NO) is also important as a signal molecule. In this study, apoptosis was selectively induced in HEp-2 cells in the early stage [1-3 h postinfection (PI)] of BHV-1 multiplication, and this apoptotic process was realised through the caspase-8, and partially through the caspase-3, pathway. BHV-1 infection inhibited staurosporine- (SS-) induced apoptosis only if the SS was added at 6 h PI. The results of this study showed that the 'NO-apoptosis' relation was realised through the caspase-8 pathway ('outer membrane receptor' pathway) at a later stage of infection in apoptosis induced by BHV-1 + SS. Our previous report (Yazici et al., 2004) and this study together showed that BHV-1 might induce and inhibit cell-type-specific pathways of apoptosis.  相似文献   
38.
39.
Natural forests offer numerous benefits to indigenous communities and society at large. Incomes from forest sources play an important role in rural households. In addition to this, environmental sources in the forests contribute significantly to rural households’ livelihoods and economic well-being. This paper examines the contributions of forests to the livelihoods of the Chakma tribe in Bangladesh. Using the data from 60 randomly sampled households from three villages, it measured forest-resource use with a monetary yardstick. As revealed through analyses, natural forest-sourced income occupies the second-largest share in total average household income next to shifting cultivation income in the study area. Forest products represent an important component in the local livelihoods, with a direct forest income of 11,256?tk?year?1?household?1 (tk = taka, the national currency of Bangladesh; US$1?=?tk70), or 11% of the total income, in addition to the households receiving monetary benefits of 18,951?tk?year?1?household?1, or 21% of the total income, through the consumption of forest products. The remaining income came from shifting cultivation practice. It was also observed that larger families with more people gathering forest products realized more forest income. This study will be relevant to forest and environmental policy-makers as well as indigenous community development practitioners.  相似文献   
40.
This study investigated the effect of type‐I interferon (IFN) on the expression of matrix metalloproteinases (MMPs) of the bovine endometrial stromal cells (BES) and epithelial cells (BEE). The cells were separated and purified from the caruncles and cultured in DMEM/F‐12 containing 10% fetal bovine serum. Spheroids were generated by using ascorbate. Zymograms of the supernatant showed that BEE predominantly expressed MMP‐9, whereas MMP‐2 was expressed in BES and homo‐spheroids. While MMPs expression was not detected in hetero‐spheroids. Real‐time quantitative PCR revealed that type‐I IFN and P4 suppressed the gene expression of MMP‐2 and MMP‐9 in hetero‐spheroids, respectively. On the other hand, gelatin zymography analysis of the supernatant showed that type‐I IFN strongly promote the clearance of MMPs. While zymograms of the MMPs stocked in the hetero‐spheroids were significantly reduced by type‐I IFN. Phenylmethanesulfonyl fluoride and leupeptin (both are serine proteinase inhibitors) significantly repressed the clearance of MMP‐2 and MMP‐9 induced by type‐I IFN. Moreover, collagen fibers in hetero‐spheroids significantly decreased after the treatment with type‐I IFN. In conclusion, it was suggested that type‐I IFN participate in the tissue remodeling by regulation the clearance of MMPs.  相似文献   
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