排序方式: 共有58条查询结果,搜索用时 31 毫秒
31.
Digestive proteolytic activities were studied in the larval midgut of Papilio demoleus by using azocasein, specific substrates and inhibitors regarding enzymatic allocation in the alimentary canal. The highest proteolytic activity was found in the midgut rather than foregut and hindgut that highest proteolytic activity was observed in soluble fraction. All specific proteases were almost equally distributed in both the anterior and posterior midgut except for trypsin- and chymotrypsin-like proteases, which showed the highest activity in the anterior midgut. Two peaks were observed in alkaline and acidic pHs when general proteolytic activities were assayed using azocasein in soluble and membrane-bound fractions. Specific substrates revealed the presence of trypsin-like, chymotrypsin-like, elastase, cathepsins B and L as well as two exopeptidases. These findings were confirmed using specific inhibitors including PMSF, TLCK, TPCK, SBTI, cystatin, DTT, E-64, EDTA and phenanthroline. Determination and characterization of the insect’s digestive proteases will enable development of pest control by designing protease inhibitors. This procedure will help us to designate an efficient pest control method with the lowest impact on the environment. 相似文献
32.
Zhiguo Zhao Sean M. Prager Regina K. Cruzado Xi Liang William R. Cooper Gongshe Hu Arash Rashed 《American Journal of Potato Research》2018,95(5):584-596
Zebra chip (ZC) disease has been a threat to the US potato industry for nearly two decades. ZC is associated with the bacteria ‘Candidatus Liberibacter solanacearum’ (Lso), which is transmitted by the potato psyllid, Bactericera cockerelli (?ulc) (Hemiptera: Triozidae). ZC reduces yield and quality, due to discoloration of the tuber tissue. Symptom severity is affected by the time of infection and early-season infections express relatively higher degrees of ZC. Although tubers infected late in the growing season, i.e. within 2 weeks of harvest, express minimal to no symptoms, they may proceed to express ZC symptoms following storage. Currently, visualization of ZC symptoms in tubers is used by processors to estimate the percentage of ZC-affected tubers in truckloads of potatoes. This approach, however, is time consuming and relies on evaluations of a small sample size. Thus, it is likely to fail in detecting the asymptomatic late infections. Using several potato genotypes infected at different times during the growing season, this study was set to determine if visible and near infrared spectrometry, and infrared thermal imaging, can be used to distinguish ZC-affected tubers, and to predict the severity of ZC symptoms. The subjective symptom score categorization, commonly used in ZC studies, corresponded with the percentage of the symptomatic area in the tubers sliced at the solon attachment end. The percentage of symptomatic area was also correlated with Lso titer. Reflectance effectively distinguished infected and uninfected tubers with high accuracy; the combined wavelengths 468, 582, 680 and 720-nm were the most effective in predicting symptom severity. Near infrared (NIR) and infrared (IR) thermal imaging failed to distinguish tubers based on Lso infection status after storage. The quantitative measure of ZC severity, and the effectiveness of some visual wavelengths in detecting ZC may help to facilitate selection assays for ZC resistance. While in our study infrared imaging did not appear to be effective in distinguishing Lso- affected tubers after storage, additional studies with field harvested tubers are still needed to evaluate the effectiveness of VIS, NIR and IR spectrometry in screening for ZC. 相似文献
33.
Homogeneity analysis of the streamflow time series is essential to hydrological modeling, water resources management and climate change studies. In this study, five absolute homogeneity tests and one clustering approach were used to determine the homogeneity status of the streamflow time series(over the period 1960–2010) in 14 hydrometric stations of three important basins(i.e., Aras River Basin, Urmia Lake Basin and Sefid-Roud Basin) in northwestern Iran. Results of the Buishand range test, von Neumann ratio test, cumulative deviation test, standard normal homogeneity test and Pettitt test for monthly streamflow time series detected that about 42.26%, 38.09%, 33.33%, 39.28% and 68.45% of the streamflow time series were inhomogeneous at the 0.01 significance level, respectively. Streamflow time series of the stations located in the eastern parts of the study area or within the Urmia Lake Basin were mostly homogeneous. In contrast, streamflow time series in the stations of the Aras River Basin and Sefied-Roud Basin showed inhomogeneity at annual scales. Based on the overall classification for the monthly and annual streamflow series, we determined that about 45.60%, 11.53% and 42.85% of the time series were categorized into the 'useful', 'doubtful' and 'suspect' classes according to the five absolute homogeneity tests. We also found the homogeneity patterns of the streamflow time series by using the clustering approach. The results suggested the effectiveness of the clustering approach for homogeneity analysis of the streamflow time series in addition to the absolute homogeneity tests. Moreover, results of the absolute homogeneity tests and clustering approach indicated obvious decreasing change points of the streamflow time series in the 1990 s over the three basins, which were mostly related to the hydrological droughts. 相似文献
34.
Ebadi Arash Raja Omid Ebrahimian Hamed Yazdani Mohammad Reza Rezaverdinejad Vahid 《Paddy and Water Environment》2022,20(1):151-151
Paddy and Water Environment - 相似文献
35.
Magnetosomes are membranous bacterial organelles sharing many features of eukaryotic organelles. Using electron cryotomography, we found that magnetosomes are invaginations of the cell membrane flanked by a network of cytoskeletal filaments. The filaments appeared to be composed of MamK, a homolog of the bacterial actin-like protein MreB, which formed filaments in vivo. In a mamK deletion strain, the magnetosome-associated cytoskeleton was absent and individual magnetosomes were no longer organized into chains. Thus, it seems that prokaryotes can use cytoskeletal filaments to position organelles within the cell. 相似文献
36.
Anaphylactic reaction rarely occurs after the 1st injection of
penicillin-streptomycin in cattle. Immediately following intramuscular injection
of a Holstein-Friesian cow with penicillin-streptomycin, the cow showed abnormal
clinical signs that included respiratory distress, urticaria, and lacrimation.
Recovery took approximately 2 h after intramuscular injection of dexamethasone.
This report presents clinical findings recorded 20 and 40 h later. 相似文献
37.
Hossein Ali Alikhani Arash Hemati Mehdi Rashtbari Scott D. Tiegs Hassan Etesami 《Communications in Soil Science and Plant Analysis》2017,48(2):139-147
In the present study we evaluated changes in phosphorus (P), nitrogen (N), and humic acid (HA) contents of vermicompost (VC) in response to temperature increases, and inoculation with N2-fixing and P-solubilizing microbes. Inoculants of Pseudomonas and Azotobacter were prepared and used to inoculate VC that was kept at 28 and 41 °C. Biological and chemical parameters of the VC were evaluated at 0, 20, 40, and 60 days. As incubation duration increased, bacterial population, N, available P, and HA content increased while organic carbon and pH decreased. These changes were most rapid during the initial 40 days of the experiment, and slowed subsequently. Increasing temperature from 28 to 41 °C reduced bacterial population and the efficiency of these bacteria in improving VC quality. Overall, our results indicate that inoculation of VC with microbes holds promise as a means of increasing the quality of VC, while our increased temperature treatment was less effective. 相似文献
38.
Ghafouri Seyed Ali GhalyanchiLangeroudi Arash Maghsoudloo Hossein KH Farahani Reza Abdollahi Hamed Tehrani Farshad Fallah Mohammad Hossein 《Tropical animal health and production》2017,49(5):1089-1093
Tropical Animal Health and Production - In 2010, H5N8 highly pathogenic avian influenza (HPAI) viruses of the A/Goose/Guangdong/1/1996 lineage dramatically affected poultry and wild birds in Asia,... 相似文献
39.
Karimi Vahid Mohammadi Peyman Ghalyanchilangeroudi Arash Ghafouri Seyed Ali Hashemzadeh Masoud Farahani Reza Khaltabadi Maghsouldoo Hussein Isakakroudi Nima 《Tropical animal health and production》2019,51(3):629-635
Tropical Animal Health and Production - Infectious bronchitis virus (IBV) is a highly infectious pathogen, which affects the respiratory tract, reproductive system, and kidney of chickens. Many... 相似文献
40.
Khaki A Novin MG Khaki AA Nouri M Sanati E Nikmanesh M 《Pakistan journal of biological sciences: PJBS》2008,11(13):1683-1689
The aim of this study was to investigate the comparative effects of aminoglycosides and fluoroquinolones on testis apoptosis and sperm parameters in rats. Fifty male Wistar rats were randomly divided into control (n = 10) and experimental (n = 40) groups. The experimental groups subdivided into four groups often. Each received 5 mg kg(-1) (IP) gentamicin, 50 mg kg(-1) (IP) neomycin, 40 mg kg(-1) (IP) streptomycin and 72 mg kg(-1) (IP) ofloxacin daily for 14 days, respectively; however, the control group just received vehicle (IP). In the fourteenth day, rats were killed and sperm analyzed for sperm parameters. Testis tissues were also prepared for TUNEL assay for detection of apoptosis. There was a significant decrease in sperm count, viability and motility in all of experimental groups when compared with control group. Although in streptomycin group these parameters were less decreased than in the other experimental groups. The apoptotic cells were significantly increased in all experimental groups when compared with those seen in the controlled group. Gentamicin, neomycin and streptomycin and ofloxacin have negative effects on sperm parameters and testis apoptosis in rats. However, these side effects are less seen in the streptomycin group. Therefore, it is recommended that usage of this drug have fewer side effects on male fertility. 相似文献