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141.
In apple cultivation, simulation models may be used to monitor fruit size during the growth and development process to predict production levels and to optimize fruit quality. Here, Fuji apples cultivated in spindle-type systems were used as the model crop. Apple size was measured during the growing period at an interval of about 20 days after full bloom, with three weather stations being used to collect orchard temperature and solar radiation data at different sites. Furthermore, a 2-year dataset (2011 and 2012) of apple fruit size measurements were integrated according to the weather station deployment sites, in addition to the top two most important environment factors, thermal and sunshine hours, into the model. The apple fruit diameter and length were simulated using physiological development time (PDT), an indicator that combines important environment factors, such as temperature and photoperiod, as the driving variable. Compared to the model of calendar-based development time (CDT), an indicator counting the days that elapse after full bloom, we confirmed that the PDT model improved the estimation accuracy to within 0.2 cm for fruit diameter and 0.1 cm for fruit length in independent years using a similar data collection method in 2013. The PDT model was implemented to realize a web-based management information system for a digital orchard, and the digital system had been applied in Shandong Province, China since 2013. This system may be used to compute the dynamic curve of apple fruit size based on data obtained from a nearby weather station. This system may provide an important decision support for farmers using the website and short message service to optimize crop production and, hence, economic benefit.  相似文献   
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143.
应用甘蓝型油菜DH系保604为材料研究小孢子胚发生过程,结果表明,在小孢子离体培养1~5d内,随培养天数增加,小孢子的存活率迅速下降,部分小孢子培养后出现细胞膨大和分裂,并沿2-细胞。“f”形3细胞,多细胞原体,胚柄球形胚,心形胚最终发育成鱼雷形胚,一般在心形胚阶段,胚柄脱离胚主体部分游离到培养基中,大多数膨大的细胞不能分裂或分裂后停止发育或发育异常。  相似文献   
144.
5-Bromo-2’-deoxyuridine-2-14C was prepared from 5-bromouracil-2-14C and 2’-de-oxyguanosine using trans-N-deoxyribosylase fromLactobacillus helveticus and incorporated into DNA ofAllium cepa roots. After isolating the DNA and hydrolyzing it enzymatically to deoxynucleoside-5’-phosphates a radioactive nucleotide was detected which yielded 5-bromo-2’-deoxyuridine-2-14C on enzymatic dephosphorylation. The incorporation of 5-iodo-2’-deoxy-uridine-2-14C was followed only by microautoradiography.  相似文献   
145.
This study investigated the role of glutathione peroxidase-1 (GPX1) in protein oxidation in peritoneal macrophages. Macrophages isolated from both wild-type (WT) and GPX1 knockout (KO) mice were activated by lipopolysaccharide (LPS, 1 microg/ml) and interferon-gamma (IFN, 10 U/ml for 24 or 48 h in the presence or absence of 1 microM diquat (DQ), 250 microM aminoguanidine (AG, an inhibitor of inducible nitric oxide synthase), and (or) 100 microM diethyldithiocarbamate (DETC, an inhibitor of Cu,Zn-SOD). In the KO macrophages, there was no protein band detected by Western blot with anti-GPX1 antibody and 98% reduction in total GPX activity compared with WT cells. Nitric oxide (NO) synthesis was greatly enhanced after 24 h by GPX1 knockout and DQ, but inhibited by AG or DETC. Protein carbonyl formation in total cell extract was clearly associated with NO synthesis as higher levels of protein carbonyl were detected in activated KO than WT macrophages, and DQ enhanced slightly while AG or DETC virtually blocked its formation. A similarly marginal effect of GPX1 KO was observed on protein nitration. The LPS/IFN/DQ-induced DNA fragmentation was blocked by AG, but not by DETC. Cell viability at 48 h was decreased by the LPS/IFN activation and further reduced by the addition of DQ, but restored by AG. In conclusion, GPX1 affects the NO production in activated peritoneal macrophages and protects these cells against NO-associated protein oxidation.  相似文献   
146.
通过对柴河林业局头道林场一块8年生的落叶松人工林优势种群的当年生的生长节律与生物量的研究发现:优势林分的当年生枝及顶枝的生长较常规林分高峰期多、高峰期持续时间长和生长量大的优点和不同;生物量的分配的研究结果也说明优势林分的树干生物量积累的比重较常规林分高,证明了该罕见优势林分速生原因的内质性,是一个难得的优良种源。  相似文献   
147.
Early diagnosis of low grade glioma has been a challenge to clinicians. Positron Emission Tomography (PET) using 18F-FDG as a radio-tracer has limited utility in this area because of the high background in normal brain tissue. Other radiotracers such as 18F-Fluorocholine (18F-FCH) could provide better contrast between tumor and normal brain tissue but with high incidence of false positives. In this study, the potential application of a dual tracer 18F-FCH/18F-FDG-PET is investigated in order to improve the sensitivity of PET imaging for low grade glioma diagnosis based on a mouse orthotopic xenograft model. BALB/c nude mice with and without orthotopic glioma xenografts from U87 MG-luc2 glioma cell line are used for the study. The animals are subjected to 18F-FCH and 18F-FDG PET imaging, and images acquired from two separate scans are superimposed for analysis. The 18F-FCH counts are subtracted from the merged images to identify the tumor. Micro-CT, bioluminescence imaging (BLI), histology and measurement of the tumor diameter are also conducted for comparison. Results show that there is a significant contrast in 18F-FCH uptake between tumor and normal brain tissue (2.65 ± 0.98), but with a high false positive rate of 28.6%. The difficulty of identifying the tumor by 18F-FDG only is also proved in this study. All the tumors can be detected based on the dual tracer technique of 18F-FCH/ 18F-FDG-PET imaging in this study, while the false-positive caused by 18F-FCH can be eliminated. Dual tracer 18F-FCH/18F-FDG PET imaging has the potential to improve the visualization of low grade glioma. 18F-FCH delineates tumor areas and the tumor can be identified by subtracting the 18F-FCH counts. The sensitivity was over 95%. Further studies are required to evaluate the possibility of applying this technique in clinical trials.  相似文献   
148.

Objectives

This study focuses on East Asian countries and investigates the difference in the marriage premium on the health-marriage protection effect (MPE) between younger and older generations and the intra-couple education concordance effect (ECE) on the health of married individuals. This study used inter-country comparative data from China, Japan, and Korea.

Methods

This study focused on individuals (n = 7,938) in China, Japan, and Korea who were sampled from the 2010 East Asian Social Survey. To investigate MPE and ECE, four health indicators were utilized: a physical and mental components summary (PCS and MCS), self-rated health status (Dself), and happiness level (Dhappy). Ordinary least squares regression was conducted by country- and gender-specific subsamples.

Results

We found that the MPE on PCS, MCS, and Dself was more significant for the older generation than for the younger generation in both China and Japan, whereas the results were inconclusive in Korea. With regard to the ECE on happiness (Dhappy), for both men and women, couples tend to be happier when both the husband and the wife are well educated (“higher balanced marriage”) compared to couples with a lower level of educational achievement (“lower balanced marriage”). Significant benefits from a “higher balanced marriage” on MCS and Dself were observed for women only. In contrast, no statistically significant differences in health status were observed between “higher balanced marriage” couples and couples with different levels of educational achievements (“upward marriage” or “downward marriage”).

Conclusions

This study found that (1) the MPE was more significant for the older generation, and (2) the health gap, particularly the happiness gap, between higher- and lower-balanced married couples was significant. The inter-country comparative findings are useful to explain how the role of marriage (and therefore of family) on health has been diluted due to the progress of industrialization and modernization.  相似文献   
149.
利用激光微束穿刺法将外源基因导入小麦的研究   总被引:20,自引:1,他引:20  
用激光微束穿刺法将携带有新霉素磷酸转移酶(NPT-Ⅱ)基因的质粒pJIT101导入京花1号小麦幼胚细胞。方法是将小麦幼胚细胞进行高渗缓冲液预处理,用微米级的激光微束处理,然后在卡那霉素培养基上筛选出具抗性的愈伤组织及绿色小植株。第一年,从150个小麦幼胚中,在卡那霉素培养基上筛选出4株绿苗,取两株进行NPT-Ⅱ酶活性分析,测到了NPT-Ⅱ酶的活性。第二年重复实验,从245个小麦幼胚中,经筛选获得1株绿苗,进行了叶片DNAPCR扩增检测,转化的绿色小苗扩增出所导入的NPT-Ⅱ基因编码的片段。结果表明,外源NPT-Ⅱ基因已导入了小麦,并实现了整合表达。  相似文献   
150.
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