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101.
Summary Video-densitometric DNA measurements of Feulgenstained tissues of 42 day old eggs of the corn snake,Elaphe g. guttata (Columbridae, Serpentes), revealed a basic DNA content of 2C=2.17 pg, with somatic polyploidy in the allantois, the chorioallontois, the yolk sac, and other extraembryonic membranes. The maximum value determined was 128C (in binucleate cells 2×128C) at the distal pole of the egg. This is the first report of somatic polyploidy in a snake, and one of the first in reptiles in general. 相似文献
102.
Summary We have investigated the actin content and ultrastructure of two kinds of presumed sensory projections on the lip epidermis of beroid ctenophores. Transmission electron microscopy showed that conical pegs contain a large bundle of densely packed, parallel microfilaments. Rhodamine-phalloidin brightly stained the pegs, confirming that they contain filamentous actin. Epidermal cells with actin pegs also bear a single long cilium with an onion-root structure, previously described as arising from a different type of cell. The actin peg and onion-root cilium project side-by-side, defining a polarized axis of the cell which is shared by neighboring cells. The onion-root body is surrounded by a flattened membranes sac which lies immediately below the plasma membrane. The perimeter of the membrane sac is encircled by aggregates of dense material. An extra layer of dense material is found along the side of the membrane sac facing the peg; this material often makes direct contact with the adjacent actin filament bundle. Cells with actin pegs and onion-root cilia synapse onto adjacent neurites and secretory gland cells, indicating that one or both types of projections are sensory elements. Since the feeding responses of beroids are reported to depend on chemical and tactile stimuli to the lips, the cells bearing pegs and cilia may function as both mechanoreceptors and chemoreceptors, that is, as double sensory receptors. 相似文献
103.
104.
John W. Duggan M.S. Clifford J. Bruell Ph.D. David K. Ryan Ph.D. 《Soil & Sediment Contamination》1994,3(2):159-182
In this article the conditions that govern surfactant‐enhanced emulsification and mobilization of petroleum hydrocarbons in soil are reviewed. The effect of soil properties, groundwater constituents, and differing surfactant solutions on the emulsification process is discussed. A constant head soil flushing apparatus used to characterize surfactant‐enhanced mobilization of m‐xylene is described. Data showing the effect of surfactant‐enhanced mobilization on m‐xylene removal efficiency in washed sand is presented. Flushing solutions were used at concentrations from below to well above the critical micelle concentration (CMC) of the surfactants used. Removal efficiencies are shown to vary with surfactant concentration and with surfactant type. Flushing solutions of anionic, nonionic, and anionic/nonionic surfactant mixtures were evaluated. 相似文献
105.
We have developed an experimental system in which the irradiation with a red light pulse induces stomatal disorientation in
the hypocotyl epidermis ofCucumis sativus L. In this system, the orientation of the division plane in guard mother cells was not defined correctly. Preprophase bands
formed in these cells but their orientation was abnormal. 相似文献
106.
BackgroundManganese (Mn) ions play a crucial role in the immune response. The immunotoxicity of Mn is rarely reported compared with the neurotoxicity of Mn.ObjectivesThe purpose of this study was to investigate the associations between chronic Mn exposure and immunological parameters in occupational Mn-exposed workers.MethodsA total of 538 workers were selected from the follow-up of manganese-exposed workers healthy cohort (MEWHC) in 2017. We divided the workers into the low-exposure group and the high-exposure group by the cutoff of the manganese-time weighted average (Mn-TWA) setting at 0.15 mg/m3. We examined serum immunological parameters by the immunoturbidimetric method and leukocyte counts and ratios in blood routine. Then we used the generalized linear model analyses and spline analyses to explore the associations between external exposure of Mn and multiple immunological parameters adjusted for variables. Based on the epidemiological analyses, we used Elisa (enzyme-linked immune sorbent assay) to detect plasma complement C3 of Mn-exposed rats.ResultsIn male workers, the mean value of complement C3 was 1.20 ± 0.16 g/L in the high-exposure group, which was significantly lower as compared to the low-exposure group (1.25 ± 0.18 g/L, P = 0.023). The generalize linear models’ analyses showed that complement C3 value had a significantly negative association with external exposure of Mn included adjustment for variables (β = -0.04, P = 0.035). Moreover, in male rats, the high-exposure group also had a lower level of complement C3 compared with the low-exposure group (P < 0.001). None significant association was observed in immunological parameters among female workers and rats (all P > 0.05).ConclusionsMn exposure from inhalable dust was associated with decreased complement C3 among occupationally Mn-exposed male individuals but not in female workers, which was further confirmed by the rat model. Further research into the possible mechanism of C3 reduction is needed in the future. 相似文献
107.
108.
《Saudi Journal of Biological Sciences》2020,27(11):2968-2971
BackgroundAmomum villosum Lour., (Zingiberaceae) an herbaceous plant in the ginger family, has been used to treat various diseases. In a single-blind, randomized, crossover study, we assessed the postprandial blood insulin and blood glucose responses in healthy subjects (n = 40) after the Amomum villosum water extract (AVE) (5 g/person) or a placebo (5 g/person) consumption.MethodsDuring each treatment course, the healthy subject consumed a regular late afternoon meal, followed by fasting for 12 h, and arrived at the clinical study center the next morning. Blood insulin and blood glucose levels were assessed at 0, 30, 60, 90, and 120 min after AVE consumption. Between each treatment, the subjects accomplished one week of a washout period.ResultsThe AVE intake demonstrated a significant (67.26%) decline in postprandial blood glucose AUC0–120 min (incremental area under the curve from 0 to 120 min) versus the placebo (P = 0.011). Furthermore, AVE reduced postprandial blood insulin AUC0–120 min by 59.95% compared to the placebo group (P < 0.003), supporting the blood glucose results.ConclusionThis study revealed that AVE consumption significantly reduced postprandial insulin and glucose levels in healthy individuals, due in part to inhibition of α-glucosidase, and glucose transport. 相似文献
109.
Although the epidermal growth factor receptor (EGFR), also known as HER1, has been studied for over a decade, it continues to be a molecule of great interest and focus of investigators for development of targeted therapies. The marketed monoclonal antibody cetuximab binds to HER1, and thus might serve as the basis for creation of imaging or therapies that target this receptor. The potential of cetuximab as a vehicle for the delivery of α-particle radiation was investigated in an intraperitoneal tumor mouse model. The effective working dose of 10 μCi of 212Pb-cetuximab was determined from a dose (10–50 μCi) escalation study. Toxicity, as indicated by the lack of animal weight loss, was not evident at the 10 μCi dose of 212Pb-cetuximab. A subsequent study demonstrated 212Pb-cetuximab had a therapeutic efficacy similar to that of 212Pb-trastuzumab (p = 0.588). Gemcitabine given 24 h prior to 212Pb-cetuximab increased the median survival from 174 d to 283 d, but carboplatin suppressed the effectiveness of 212Pb-cetuximab. Notably, concurrent treatment of tumor-bearing mice with 212Pb-labeled cetuximab and trastuzumab provided therapeutic benefit that was greater than either antibody alone. In conclusion, cetuximab proved to be an effective vehicle for targeting HER1-expressing tumors with α-radiation for the treatment of disseminated intraperitoneal disease. These studies provide further evidence that the multimodality therapy regimens may have greater efficacy and benefit in the treatment of cancer patients. 相似文献
110.
In our previous studies, we observed the biological control effect of lactic acid bacteria strains (LABs) KLF01, KLC02 and KPD03 against different plant pathogenic bacteria in vitro against Ralstonia solanacearum, and strains KLF01 and KLC02 against Pectobacterium carotovorum under greenhouse and field experiments, respectively. In this study, we observed the efficacy of these bacteria against bacterial spot pathogen (Xanthomonas campestris pv. vesicatoria) and their plant growth-promoting activities in pepper (Capsicum annuum L. var. annuum), under greenhouse and field conditions. LABs significantly (P < 0.05) reduced bacterial spot on pepper plants in comparison to untreated plants in both the greenhouse and the field experiments. The plant growth-promoting effect of LABs on pepper varied; some strains had a significant effect on growth promotion (P < 0.05) compared with untreated plants, while some showed no significant effect in the greenhouse and field experiments. Additionally, LABs were able to colonise roots, produce indole-3-acetic acid (IAA), siderophores and solubilise phosphate. These findings indicate that application of LABs could provide a promising alternative for the management of bacterial spot disease in pepper plants and could therefore be used as a healthy plant growth-promoting agent. 相似文献