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1.
The effects on yield in courgette and marrow (Cucurbita pepo) crops resulting from inoculation with the mild strain of zucchini yellow mosaic virus (ZYMV:WK), have been determined in polythene-house trials and in three years of outdoor, commercial field trials. In polythene-house trials ZYMV:WK inoculated plants were up to 10 days later in flowering than uninoculated plants and their cumulative yields were between 5% and 26% less than uninoculated plants depending on the cultivar. In most field trials cumulative yields from inoculated plants were between 4% and 38% less than uninoculated plants depending on the site and cultivar, but in one trial the yield was 7% higher from inoculated plants. In all experiments, courgette and marrow fruits harvested from ZYMV:WK inoculated plants were symptomless and indistinguishable from fruit harvested from uninoculated plants. The mild leaf symptoms induced by ZYMV:WK infection did not intensify to severe leaf symptoms and where there were natural outbreaks of severe ZYMV infection, fruits from inoculated plants remained symptomless whilst those from uninoculated plants were severely affected and unmarketable.  相似文献   
2.
我国大麦和性花叶病毒(BaMMV)研究初报   总被引:3,自引:0,他引:3  
本文根据F(ab′)2-ELISA和ISEM实验,结合病毒粒子长度测定,报道了江苏省如东县农科所大麦黄花病毒源(吕种盐辐矮早3)中除存在大麦花花叶病毒(BaYMV)外,还复合感染大麦和性花叶病毒(BaMMV),这是我国BaMMV的第一次报道。  相似文献   
3.
Global climate change is projected to increase the incidence of heat waves, their magnitude and duration resulting in insects experiencing increasing environmental stress in both natural and managed ecosystems. While studies on insect thermal tolerance are rapidly increasing, variation across developmental or juvenile stress cross-stage effects within and across generations remain largely unexplored. Yet in holometabolous insects, heat stress at an early developmental stage may influence performance and survival during later stages. Here, we investigated the effects of pupal mild heat stress on the performance of laboratory-reared adult Bactrocera dorsalis (Hendel) (Diptera: Tephritidae) measured as longevity, critical thermal maximum (CTmax), critical thermal minima (CTmin), heat knockdown time (HKDT) and chill coma recovery time (CCRT). Pupal heat stress significantly influenced performance of B. dorsalis adults resulting in impaired longevity and heat tolerance (CTmax and HKDT) in both sexes with improved and compromised cold tolerance (CTmin and CCRT) in females and males, respectively. These findings highlight the role of juvenile stages in mediating stress responses at adult stages. For B. dorsalis, pupal heat stress largely compromised thermal tolerance implying that the species has limited potential to shift its geographic range in heat prone areas. Significant benefits in cold tolerance in females following heat stress may help in improving survival in the cold in the short-term despite restricted activity to the same traits in males. This study suggests that basal heat tolerance and not short-term compensatory thermal plasticity following heat stress may have aided the recent invasion of B. dorsalis in African landscapes.  相似文献   
4.
5.
摘要 目的:观察天麻素对小鼠抑郁症模型异常行为的改善以及Janus激酶2-信号转导和转录激活因子3(JAK2 -STAT3)信号通路的表达变化。方法:40只雄性昆明小鼠,随机分为正常组和模型组。模型组小鼠经过4周CUMS刺激建模,第6周检测小鼠行为学变化以验证建模效果。随后将模型组分为CUMS+生理盐水、CUMS+氟西汀以及CUMS+天麻素3个亚组,第7-8周继续进行CUMS刺激,同时对3个亚组小鼠腹腔注射给药。第9周再次进行行为学检测。取小鼠脑组织进行HE染色(hematoxylin-eosin staining)和蛋白免疫印迹(western blot)检测。结果:第6周检测结果显示:与对照组比较,模型组小鼠体重增幅显著降低(P<0.001),悬尾和强迫游泳不动时间显著增加(P<0.001、P<0.001),糖水消耗率显著降低(P<0.001)。第9周检测结果显示:与CUMS+生理盐水组相比,CUMS+氟西汀组和CUMS+天麻素组小鼠体重增幅显著增加(P<0.001,P<0.001),强迫游泳不动时间显著降低(P<0.001,P<0.001),悬尾不动时间显著降低(P<0.01,P<0.01),糖水消耗率显著增加(P<0.001、P<0.001)。与CUMS+生理盐水组比较,CUMS+天麻素组小鼠JAK2、STAT3、IL-1β蛋白表达显著降低(P<0.01、P<0.01、P<0.05);HE染色结果提示,CUMS+生理盐水组小鼠神经元形态发生改变,细胞结构不清晰,细胞核固缩、深染;与CUMS+生理盐水组相比,CUMS+天麻素组小鼠神经元形态得到改善。结论:天麻素可以有效改善CUMS诱导的小鼠抑郁样行为,其作用可能与JAK2-STAT3信号通路关键蛋白的表达有关。  相似文献   
6.
Myocardial ischemia-reperfusion injury (MIRI) with concurrent severe sepsis has led to substantial mortality. Mild hypothermia (MHT) has been proved to have a therapeutic effect in either MIRI or severe sepsis, which suggests it might be beneficial for MIRI complicating severe sepsis. In this study, Sprague-Dawley rats with MIRI complicating severe sepsis were allotted in either MHT (33 ± 0.5°C) group or normothermia (NT, 37 ± 0.5°C) group; as control, rats receiving sham surgery and normal saline were kept at NT. After 2h of temperature maintenance, blood and heart tissue were acquired for detections. Lactate dehydrogenase (LDH) and MB isoenzyme of creatine kinase (CK-MB) in blood, triphenyl tetrazolium chloride and Evans blue staining, hematoxylin and eosin staining for myocardium were employed to detect myocardial damage. Tumor necrosis factor (TNF)-α and caspase-3 was performed by immunohistochemistry to exam myocardial inflammation and apoptosis. Detection of NADPH oxidase (NOX) 2 was for myocardial oxidative stress. In MHT group, systolic blood pressure was improved significantly compared with NT group. Myocardial infarct size, morphological change, LDH and CK-MB levels were attenuated compared to NT group. Moreover, less expressions of TNF-α, caspase-3 and NOX2 in MHT group were presented compared with NT group. MHT showed cardioprotection by improving cardiac dysfunction, reducing myocardial infarct size and attenuating myocardial injury, inflammation, apoptosis and oxidative stress.  相似文献   
7.
This study aimed to uncover the protective potentiality of resveratrol and dimethyl fumarate (DMF) in the liver of a chronic unpredictable mild stress (CUMS)‐induced depression animal model. Resveratrol and DMF significantly alleviated CUMS‐induced behavioral abnormalities in stressed rats through improving sucrose preference in sucrose preference test and decreasing immobility time in a forced swimming test. They also mitigated serum corticosterone levels and elevated serum serotonin levels, which were formerly disturbed in CUMS rats. The hepatoprotective effect is evidenced by improvement in hepatic histopathological examinations, as well as normalized serum alanine aminotransferase and aspartate aminotransferase activities. Molecular signaling of resveratrol and DMF was estimated by diminishing hepatic expression of phosphorylated p38 mitogen‐activated protein kinase (MAPK), extracellular signal‐regulated kinase1/2 (ERK1/2), and c‐Jun N‐terminal kinase (JNK). Consequently, they improved the hepatic antioxidant and anti‐inflammatory activities as elaborated by the normalization of total antioxidant capacity, glutathione, malondialdehyde, nuclear factor‐κB, tumor necrosis factor‐α, and myeloperoxidase levels. In addition, they inhibited hepatocyte apoptosis as evidenced by the increased expression of B‐cell lymphoma 2, the decreased expression of Bax, as well as the suppressed activity of caspase‐3. In conclusion, resveratrol and DMF purveyed a significant anti‐depressant effect, which may be mediated, at least in part, via inhibiting the MAPK/ERK/JNK pathway in the CUMS rat model.  相似文献   
8.
Higher levels of macrophage inhibitory cytokine‐1, also known as growth differentiation factor 15 (MIC‐1/GDF15), are associated with adverse health outcomes and all‐cause mortality. The aim of this study was to examine the relationships between MIC‐1/GDF15 serum levels and global cognition, five cognitive domains, and mild cognitive impairment (MCI), at baseline (Wave 1) and prospectively at 2 years (Wave 2), in nondemented participants aged 70–90 years. Analyses were controlled for age, sex, education, Framingham risk score, history of cerebrovascular accident, acute myocardial infarction, angina, cancer, depression, C‐reactive protein, tumor necrosis factor‐α, interleukins 6 and 12, and apolipoprotein ε4 genotype. Higher MIC‐1/GDF15 levels were significantly associated with lower global cognition at both waves. Cross‐sectional associations were found between MIC‐1/GDF15 and all cognitive domains in Wave 1 (all < 0.001) and between processing speed, memory, and executive function in Wave 2 (all < 0.001). Only a trend was found for the prospective analyses, individuals with high MIC‐1/GDF15 at baseline declined in global cognition, executive function, memory, and processing speed. However, when categorizing MIC‐1/GDF15 by tertiles, prospective analyses revealed statistically significant lower memory and executive function in Wave 2 in those in the upper tertile compared with the lower tertile. Receiver operating characteristics (ROC) analysis was used to determine MIC‐1/GDF15 cutoff values associated with cognitive decline and showed that a MIC‐1/GDF15 level exceeding 2764 pg/ml was associated with a 20% chance of decline from normal to MCI or dementia. In summary, MIC‐1/GDF15 levels are associated with cognitive performance and cognitive decline. Further research is required to determine the pathophysiology of this relationship.  相似文献   
9.

Background

The value of genotyping to predict variant phenotypes in patients with phenylalanine hydroxylase (Pah) deficiency is a matter of debate. However, there exists no comprehensive population relationship study focused on the Han Chinese.

Methods

We analyzed genotype–phenotype correlation for 186 different genotypes in 338 unrelated Chinese patients harboring 109 different Pah mutations. Two systems were used in this process. The first was a phenotype prediction system based on arbitrary values (AV) attributed to each mutation. The second was a pair-wise correlation analysis. The observed phenotype for AV analysis was the corresponding metabolic phenotype stratified according to the pretreatment phenylalanine (Phe) value.

Results

We found that the observed phenotype matched the predicted phenotype in 54.41% of 272 patients for whom AV information was available; the highest degree of concordance (61.83%) was found in patients with null/null genotypes, whereas the lowest “concordance rate” (32.69%) was observed for patients with expected mild-PKU phenotype. There are repeated inconsistencies for such mutations as R241C, R243Q, R261Q, V388M, V399V, R408Q, A434D and EX6-96A>G which are associated with variable phenotypes in patients with identical genotype. Significant correlations were disclosed between pretreatment Phe values and predicted residual activity (r = − 0.45643, P < 0.0001) or AV sum (r = − 0.59523, P < 0.0001).

Conclusion

Our study supports the notion that the Pah mutation genotype is the main determinant of metabolic phenotype in most patients in a particular population, and provided novel insights into the values that underpin the subsequent treatment and the prognosis of PKU in Chinese.  相似文献   
10.

Three different types of biocides, viz. formaldehyde (FM), glutaraldehyde (GA) and isothiozolone (ITZ) were used to control planktonic and sessile populations of two marine isolates of sulphate‐reducing bacteria (SRB). The influence of these biocides on the initial attachment of cells to mild steel surfaces, on subsequent biofilm formation and on the activity of hydrogenase enzymes within developed biofilms was evaluated. In the presence of biocides the rate and degree of colonization of mild steel by SRB depended on incubation time, bacterial isolate and the type of biocide used. Although SRB differed in their susceptibility to biocides, for all isolates the biofilm population was more resistant to the treatment than the planktonic population. GA showed highest efficiency in controlling planktonic and sessile SRB compared with the other two biocides. The activity of the enzyme hydrogenase measured in SRB biofilms varied between isolates and with the biocide treatment. No correlation was found between the number of sessile cells and hydrogenase activity.  相似文献   
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