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131.
The effects of the herbicide thiobencarb (Saturn) were tested on the growth and physiology of the chlorophyte Protosiphon
botryoides isolated from an Egyptian paddy. Assays were conducted using 16-day batch cultures. Chlorophyll and dry weight
biomass yields were significantly reduced at 2–3 mg L-1 thiobencarb, and dark respiration increased and protein decreased significantly at 3 mg L-1. Reductions in exponential specific growth rate (μ) were generally small, but in some cases significant. Thiobencarb also
slightly, but significantly, reduced the 77 K fluorescence parameter Fv/Fm, an indicator of maximum photosynthetic efficiency.
No consistent dose-dependent changes occurred in chlorophyll per unit dry weight, total carbohydrate or gross photosynthetic
capacity. Whereas half of the added thiobencarb was recovered from control (uninoculated) medium, it was largely absent from
cells and culture medium after sixteen days, indicating biodegradation by the alga or associated bacteria. P. botryoides recovered
fully within sixteen days following subculture in thiobencarb-free medium. Independently varying phosphate and nitrate nine-fold
had no clear effect on the sensitivity of P. botryoides to thiobencarb.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
132.
Binding of Extracellular Carboxymethylcellulase Activity from the Marine Shipworm Bacterium to Insoluble Cellulosic Substrates 下载免费PDF全文
The binding of extracellular endoglucanase, a carboxymethylcellulase (CMCase), produced by the marine shipworm bacterium to insoluble cellulose substrates was investigated. Up to 70% of CMCase activity bound to cellulosic substrates, and less than 10% bound to noncellulosic substrates. CMCase binding to cellulose was enhanced in basal salt medium or sodium phosphate buffer containing 0.5 M NaCl. Increased cellulose particle size correlated with decreased CMCase binding. Also, cellulose treated with either 5 N NaOH or commercial cellulase reduced the CMCase binding to these surfaces. Pretreatment of CMCase preparations with 0.01% sodium dodecyl sulfate, 5% β-mercaptoethanol, and 5 mM EDTA or ethylene glycol-bis(β-aminoethyl ether)-N,N,N′,N′-tetraacetic acid (EGTA) had little effect on binding to cellulose. While pretreatment of CMCase with trypsin, chymotrypsin, and pronase had little effect on CMCase enzymatic activity, the ability to bind to cellulose was greatly diminished by these treatments. 相似文献
133.
Mayssa Ben Mustapha Faisal K. Algethami Mohamed R. Elamin Babiker Y. Abdulkhair Ikbal Chaieb Hichem Ben Jannet 《化学与生物多样性》2023,20(3):e202200978
In this work, essential oils extracted from roots and aerial parts of Inula graveolens by hydrodistillation and their fractions obtained by chromatographic simplification were first investigated for their chemical composition by GC/MS and then evaluated for the first time for their repellency and contact toxicity properties against Tribolium castaneumadults. Twenty-eight compounds were identified in roots essential oil (REO), which accounted for 97.9 % of the total oil composition, with modhephen-8-β-ol (24.7 %), cis-arteannuic alcohol (14.8 %), neryl isovalerate (10.6 %) and thymol isobutyrate (8.5 %) as major constituents. Twenty-two compounds were found in the essential oil from aerial parts (APEO), which accounted for 93.9 % of the total oil, with borneol (28.8 %), caryophylla-4(14),8(15)-dien-6-ol (11.5 %), caryophyllene oxide (10.9 %), τ-cadinol (10.5 %) and bornyl acetate (9.4 %) as main compounds.REO and APEO displayed stronger repellency after 2 h of exposure (80.0 and 90.0 %, respectively) against T. castaneum at the concentration of 0.12 μL/cm2. After fractionation, fractions R4 and R5 exhibited greater effects (83.3 % and 93.3 %, respectively) than the roots essential oil. Furthermore, the fractions AP2 and AP3 showed higher repellency (93.3 and 96.6 %, respectively) than the aerial parts oil. The LD50 values of oils from roots and aerial parts topically applied were 7.44 % and 4.88 %, respectively. Results from contact toxicity assay showed that fraction R4 was more effective than the roots oil with LD50 value of 6.65 %. These results suggests that essential oils of roots and aerial parts from I. graveolens may be explored as potential natural repellent and contact insecticides against T. castaneum in stored products. 相似文献
134.
Shan-Rong Shi Benjaporn Chaiwun Lillian Young Ashraf Imam Richard J. Cote Clive R. Taylor 《Biotechnic & histochemistry》1994,69(4):213-215
A new antibody (MIB-1) has been described, permitting the demonstration of Ki-67 proliferation antigen in paraffin sections. However, satisfactory results were obtained only after subjecting tissue sections to microwave based antigen retrieval in citrate buffer solution. Other buffer solutions produce equivalent or better results and also permit use of the original Ki-67 antibody, which hitherto has been considered ineffective for paraffin sections. 相似文献
135.
Imam Hasan Mir Rubayet Jahan Md Nabiul Islam Mohammad Rafiqul Islam 《Saudi Journal of Biological Sciences》2022,29(1):102
Electromagnetic field exposure to the nervous system can cause neurological changes. The effects of extremely low-frequency electromagnetic fields, such as second-generation and third-generation radiation, have been studied in most studies. The current study aimed to explore fourth-generation cellular phone radiation on hippocampal morphology and behavior in mice. Swiss albino male mice (n = 30) were randomly categorized into 3 groups; control, 40 min, and 60 min exposure to 2400 MHz radiofrequency electromagnetic radiation (RF-EMR) daily for 60 days. The control mice were housed in the same environments but were not exposed to anything. Anxiety-like behaviors were tested using the elevated plus-maze. For histological and stereological examination, the brain was dissected from the cranial cavity. On Cresyl violet stained brain slices, the number of pyramidal neurons in the cornu ammonis of the hippocampus were counted. In exposed mice compared to control mice, a significant increase in anxiety-like behavior has been observed. Histological observations have shown many black and dark blue cytoplasmic cells with shrunken morphology degenerative alterations in the neuronal hippocampus in the radiation exposed mice. In the RF-EMR mouse hippocampus, stereological analyses revealed a significant decrease in pyramidal and granule neurons compared to controls. Our findings suggest that 2400-MHz RF-EMR cell phone radiation affects the structural integrity of the hippocampus, which would lead to behavioral changes such as anxiety. However, it alerts us to the possible long-term detrimental effects of exposure to RF-EMR. 相似文献
136.
Perkinsus marinus Extracellular Protease Modulates Survival of Vibrio vulnificus in Eastern Oyster (Crassostrea virginica) Hemocytes 下载免费PDF全文
B. D. Tall J. F. La Peyre J. W. Bier M. D. Miliotis D. E. Hanes M. H. Kothary D. B. Shah M. Faisal 《Applied microbiology》1999,65(9):4261-4263
The in vitro effects of the Perkinsus marinus serine protease on the intracellular survival of Vibrio vulnificus in oyster hemocytes were examined by using a time-course gentamicin internalization assay. Results showed that protease-treated hemocytes were initially slower to internalize V. vulnificus than untreated hemocytes. After 1 h, the elimination of V. vulnificus by treated hemocytes was significantly suppressed compared with hemocytes infected with invasive and noninvasive controls. Our data suggest that the serine protease produced by P. marinus suppresses the vibriocidal activity of oyster hemocytes to effectively eliminate V. vulnificus, potentially leading to conditions favoring higher numbers of vibrios in oyster tissues. 相似文献
137.
Khulood M. Al-Majali Anne M. Glazier Penny J. Norsworthy Faisal N. Wahid Lisa D. Cooper Caroline A. Wallace James Scott Berthold Lausen Timothy J. Aitman 《Mammalian genome》1999,10(5):471-476
Radiation hybrid (RH) mapping has been used to produce genome maps in the human and mouse, but as yet the technique has been
applied little to other species. We describe the use of RH mapping in the rat, using a newly available rat/hamster RH panel,
to construct an RH map of the proximal part of rat Chromosome (Chr) 4. This region is of interest because quantitative trait
loci (QTLs) for defective insulin and catecholamine action, hypertension, and dyslipidemia map to this region. The RH map
includes 23 rat genes or microsatellites previously mapped to this part of Chr 4, one rat gene not previously mapped in the
rat, and markers for four new genes, homologs of which map to the syntenic region of the mouse genome. The RH map integrates
genetic markers previously mapped on several rat crosses, increases the resolution of existing maps, and may provide a suitable
basis for physical map construction and gene identification in this chromosomal region. Our results demonstrate the utility
of RH mapping in the rat genome and show that RH mapping can be used to localize, in the rat genome, the homologs of genes
from other species such as the mouse. This will facilitate identification of candidate genes underlying QTLs on this chromosomal
segment.
Received: 4 December 1998 / Accepted: 19 January 1999 相似文献
138.
139.
Nathalie Bouloc Jonathan M. Large Magda Kosmopoulou Chongbo Sun Amir Faisal Mizio Matteucci Jóhannes Reynisson Nathan Brown Butrus Atrash Julian Blagg Edward McDonald Spiros Linardopoulos Richard Bayliss Vassilios Bavetsias 《Bioorganic & medicinal chemistry letters》2010,20(20):5988-5993
Co-crystallisation of the imidazo[1,2-a]pyrazine derivative 15 (3-chloro-N-(4-morpholinophenyl)-6-(pyridin-3-yl)imidazo[1,2-a]pyrazin-8-amine) with Aurora-A provided an insight into the interactions of this class of compound with Aurora kinases. This led to the design and synthesis of potent Aurora-A inhibitors demonstrating up to 70-fold selectivity in cell-based Aurora kinase pharmacodynamic biomarker assays. 相似文献
140.
McLaughlin SM Elsayed EE Faisal M 《Comparative biochemistry and physiology. Part B, Biochemistry & molecular biology》2000,126(4):587-598
Biochemical characterization of the extracellular proteins (ECP) of two softshell clam Perkinsus spp. cloned isolates, Perkinsus chesapeaki isolate G-117 and Perkinsus marinus H-49, was performed and compared to that of the oyster-derived P. marinus isolate P-1. G-117 and H-49 demonstrated distinct differences in enzyme activities; however, all three isolates shared common bands. Substrate-impregnated gels showed H-49 to possess proteolytic activities while G-117 did not. Inhibition studies revealed that H-49 ECP contain serine proteases similar to those described for P-1. The G-117 ECP lacked proteolytic activity but showed a higher production of lipolytic enzymes than H-49 or P-1. Optimal in vitro growth temperatures for the two clam isolates were generally lower than those for P-1. G-117 showed faster growth at lower salinities than either H-49 or P-1. Clam Perkinsus spp. isolates appear to be better adapted to lower salinities and temperatures than the P. marinus isolate of the eastern oyster. 相似文献