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In this study, the effects of xylazine on serum levels of triiodothyronine (T3), tetraiodothyronine (T4), insulin (INS), and glucagon (GN) in dogs were investigated. The dogs before injection were used as control group (0 h). The dogs were injected with xylazine at 3 mg/kg, then blood was collected from the peripheral veins at 0.5, 2, 8, 24, 48, 72, and 120 h after the injection. Serum T3, T4, INS, and GN were measured by ELISA. The results revealed that the T3 level decreased in serum 0.5 h after the injection (P<0.05), while the change in T4 was not significant. The secretion of INS increased 8 h after the injection (P<0.05). The GN level increased 2 h and 8 h after the injection (P<0.05). However, all of these changes returned to the norm after 24 h.
The sensitivity of Betula ermanii tree-ring growth to climate variation over an altitudinal gradient was assessed. Betula ermanii forest grows in the northern slope of Changbai Mountain from approximately 1,700mabove sea level (a.s.l.), andforms the upper tree line at nearly 2,100ma.s.l.. Six study sites were constructed along the altitudinal gradient (1,670 to 2,010 m a.s.l.) and ring-width chronologies of Betula ermanii were built. The mean tree-ring series intercorrelation (RBAR) increasedwith elevation. In principal component analysis, the first unrotatedprinciple component explained77.1% of the total variance, indicating the tree-ring growth of Beutla ermanii over the altitudinal gradient was governed by regional climate. Correlation function analysis revealedthat the radial growth of Betula ermanii was significantly similar in response to climatic conditions. Overall, the low temperatures during previous June, July and during the dormant period (previous October to current May) andthe high temperatures during current June, July andAugust would benefit the radial growth of Betula ermanii. Abundant precipitation during growing season (previous June, July, September andcurrent August), previous November andcurrent May, wouldalso facilitate the tree-ring growth. The reason for this uniform growth behavior in Betula ermanii remainedunclear. Betula ermanii in Changbai Mountain formedrelatively pure stands with an open canopy, which might be partly contributing to the common growth response to climatic signals along the altitudinal gradient, but further work was required for testing this assumption.
To explore the accumulation and distribution of Cadmium (Cd) in flue-cured tobacco and the effect on soil microbial community structure in the rhizosphere, pot experiments were conducted with different treatment levels of Cd (0, 2, 4, 8, and 16 mg·kg⁻¹). The Cd accumulation in different organs of flue-cured tobacco was analyzed, and the bacteria and fungi community structures in the rhizosphere were examined using PCR-DGGE fingerprinting with universal bacteria and fungi primers. Results showed that the order of Cd contents in different organs of flue-cured tobacco was: leaf > stem > root. Increasing Cd concentration in the pot soil elevated Cd contents in different organs of flue-cured tobacco. As to the soil microbial community, the bacterial fingerprinting bands in rhizosphere with 4 mg·kg⁻¹ Cd level were significantly less than other treatments. Some bacteria disappeared with increasing soil Cd concentrations. Nevertheless, some special bacteria apparently had a strong restoration capability in the rhizosphere at a high Cd contamination level (16 mg·kg⁻¹). Among the 8 clusters of bacterial communities identified by the sequencing, the Bacterium ellin, Acidobacteria bacterium ellin, and Mycobacterium had strong resistance and adaptability to Cd contamination of different concentrations, whereas the Leptolyngbya had strong adaptability to Cd contamination of moderate concentration, which could become the dominant population at this level. The fungi community diversity in the rhizosphere with different concentrations of Cd was significantly different from the pattern of bacteria. Some fungi appeared with the increase of Cd concentration, but some fungi disappeared at the moderate Cd concentration (4 mg·kg⁻¹). Among the 4 clusters of fungal communities identified by the sequencing, the Fusarium and unknown species were the dominant species in the fungi community, which existed in all treatments and had strong adaptability to different Cd concentrations. The Acremonium sclerotigenum was sensitive to Cd contamination and disappeared at Cd concentrations greater than 2 mg·kg⁻¹, but Rhizopus appeared at Cd concentrations greater 8 mg·kg⁻¹, suggesting its preference for high Cd concentrations. Flue-cured tobacco had a strong ability to absorb and accumulate Cd. A proper concentration of Cd might have a positive effect on the soil bacteria and fungi community structure of flue-cured tobacco rhizosphere.
We investigated the response of Mn-hyperaccumulator Phytolacca americana L. to manganese excess as well as the relationships between lignin deposition in the plant’s leaves, peroxidase and laccase activities in the leaf apoplast, and Mn toxicity. The exceptionally high tolerance of P. americana to Mn, both in solution and in tissue, was confirmed. No visible brown spot was observed in the leaves of plants treated with B10,000 µM Mn for 10 days. Mn treatment significantly increased lignin content and laccase activity in the apoplastic washing fluid (AWF) of P. americana leaves. In contrast, an increase in the Mn supply was paralleled by a significant decrease in the concentration of total phenolic compounds (TPCs) and in water-soluble guaiacol peroxidase (SPOD) activity in leaf AWF. This result suggested that an increase in lignin deposition decreased the concentration of apoplastic TPCs that are available to generate potentially toxic intermediates by acting as peroxidase substrates. Thus, data of the present study indicate that lignin formation by laccase activities reduces Mn toxicity and increases Mn tolerance of P. americana by depressing SPOD-mediated formation of toxic intermediates from TPCs.
Selenium (Se) is indispensable to animals. The aims of this study were to explore the threshold dose of Se application in soil and reveal the mechanism of selenite effect on alfalfa growth, which is important for producing Se-enriched forage. Pot experiments were carried out in a greenhouse to explore the physiological mechanisms that are related to the response of forage crop to Se application. Alfalfa plants were treated with different Se levels (Se as Na₂SeO₃ dissolved in water was evenly sprinkled on the soil) to determine the effects of selenite supply on antioxidant activity, photosynthetic parameters, root activities, and the absorption of essential elements of alfalfa. Compared with the control plants, those treated with 5 and 10 mg kg⁻¹ Se exhibited increased shoot Se concentrations by 4.5- and 8.1-fold, respectively. The Se partitioning factors for alfalfa ranged from 0.47 to 0.89. The dry weights of roots and whole plants reached maximum values after applying 1 mg kg⁻¹ Se. At < 20 mg kg⁻¹ Se, plant growth was not inhibited in contrast to the control plants, and the activities of antioxidants superoxide dismutase (SOD), peroxidase (POD), and glutathione peroxidase (GSH-Px) increased, whereas the MDA content decreased significantly. With low-dose Se, the photosynthetic parameters (except for intercellular CO₂ concentration), leaf pigment content, and root activities were significantly enhanced, and the absorption of micronutrient elements (Fe and Mn) was promoted. However, at > 20 mg kg⁻¹ Se, the plant growth, antioxidant enzyme activity, photosynthetic parameters, root activity, and P and K absorption were inhibited. Alfalfa growth was not negatively affected by Se application less than 20 mg kg⁻¹. Low-dose selenite (0.5 and 1 mg kg⁻¹ Se) stimulated plant growth, mainly due to the stimulation of root growth by enhancing root activities and therefore promoting the absorption of P, K, Ca, Fe, and Mn. The increase in antioxidant enzyme activity and net photosynthetic rate partially resulted from the increased carotenoid content, which also contributed to the increasing dry matter at low-dose selenite levels. Given the relatively high transport efficiency of Se from root to overground part, alfalfa can be potentially used in the production of Se-enriched forage, and 10 mg kg⁻¹ Se is the optimum reference dose of Se application in soil.
The purpose of the study was to define if anaesthetic action of xylazine could conceivably result from the potentiation of inhibitory neurotransmitters or the inhibition of excitatory neurotransmitter systems in the brain. Rats were injected with xylazine at a dose of 50 mg/kg b.w., and then the hippocampus and thalamencephal were removed at 0.1, 0.25, 0.5, 1, 1.5, 2, 4, and 6 h after the injection. Glutamate (Glu) and γ-aminobutyric-acid (GABA) were measured in the brain tissue by reversed-phase high-performance liquid chromatography. The results revealed that the hippocampus Glu level decreased significantly 0.1 h after the injection of xylazine, the thalamencephal GABA increased significantly 0.1 h after the injection, while the changes in hippocampus GABA and thalamencephal Glu were not significant. However, all of these changes returned to the normal level after 2 and 4 h, respectively. The results indicated the relative effects of xylazine on Glu and GABA levels in the hippocampus and thalamencephal.
Barley yellow dwarf virus (BYDV) can cause significant losses of wheat worldwide. The long arm segment of Thinopyrum intermedium chromosome 7Ai#1 carrying the BYDV resistance gene Bdv2 was translocated to the distal region of the long arm of wheat chromosome 7D in translocation line Yw642. In this study, 40 wheat EST sequences located in the distal region of 7DL were explored to identify specific PCR markers for the Bdv2 region on the basis of the homoeologous relationship between wheat chromosome 7D and Th.intermedium chromosome 7Ai#1. Our results revealed 8 novel EST-PCR markers specific to the Bdv2 region, including 5 EST-STS markers of BE404744, BE498985, BE591497, BG606695 and BQ161842, and 3 EST-SSCP markers of BE404953, BG312663 and BE498985. These EST-PCR markers could distinguish Bdv2 from another BYDV-resistance gene located on Th.intermedium chromosome 2Ai-2. These specific bands for the Bdv2 region were further cloned and sequenced. The sequencing analysis indicated that the specific sequences for the Bdv2 region were highly homologous with the original wheat EST sequences that were used to design primers, and encode respectively a protein kinase, P450, centrin, transducin, and a hypothetical protein. This study created a starting point for eventual cloning of the Bdv2 gene and understanding the defense mechanism.
To exam ine the residues and distributions of hexachlorocyclohexanes (HCHs), dichlorodiphenyltrichloroethane (DDT), and other organochlorine pesticides (OCPs ) in the Weihe River basin of northwest China, a gas chromatography-mass spectrometer (GC-MS) was employed to analyze the samples collected from surface water, suspended solids, and sediments. Results showed that total concentrations of HCHs, DDT, and othe r OCPs in surface water were in the range of 2.41-178.18, 0.94-116.83, and 3.64-37.17 ng/L, respectiv ely; in suspended solids they were 5 1.76-241.23, 2.82-12.23, and 11.35-37.67 ng/L, respectively; and in sediments they were 74.13-517.49, 1.20-370.98, and 7.94-110.13 ng/g dry weight, respectively. The α-HCH/γ-HCH ratio indicated that historical usage of technical mixtures of HCHs was the main source of HCHs. The DDT ratio indicated that DDT at most sites came from older uses of technical DDT. Compared with some guideline values of OCPs in surface water, the concentrations of HCHs and DDT were at safe levels. Meanwhile, the Weihe Riv er sediments have high ecological risk pesticides.
Water contamination poses serious threats to human health and is more prevalent in developing countries. A bio sand filter (BSF) is useful technology for developing nations because of its low cost and good treatment effi ciency. Being a locally available plant species, melia (Melia azedarach) biomass was used in BSF to test its effi ciency for metal and pathogen removal. Different concentrations (2~6 mg/L) of iron and lead and Escherichia coli-contaminated water were passed through a control sand filter (having no plant biomass) and BSF. The results showed that all three contaminants had higher removal rates in the BSF compared to the control sand filter. The removal of E.coli reached up to 100 percent on some days in the BSF, which was not the case with the control sand fi lter. The percent removal of Fe and Pb in BSF was 97.9~99.9% and 31~61%, respectively. Signifi cant turbidity removal was also observed in BSF. Melia biomass is a useful bio-resource that can help to improve water quality in BSF.
The purpose of the study was to define transient changes in the concentration of inflammatory biomarkers and cartilage biomarkers in the synovial fluid of joints following experimentally induced acute equine synovitis. Acute synovitis was induced in eight skeletal!) mature mares by a sterile intra-articular injection of 1 mL of phosphate-buffered saline (PBS) containing 0.5 ng of lipopolysaccharide (LPS). The solution was injected into the right middle carpal joint. One mL of sterile PBS was injected into the left control joint. Synovial fluid was obtained at the baseline level and at 8, 24, and 168 h after injection. The levels of inflammatory biomarkers-prostaglandin E2 (PGE2), interleukin 1ß (IL-1 ß), and tumour necrosis factor-α (TNF-α), and cartilage turnover biomarkers-collagenase-cleavage neoepitope of type II collagen (C2C) and C-terminal crosslinked telopeptide type II collagen (CTX-II) were detected with proper assays. Single injections of LPS raised the number of svnovial white blood cells and concentrations of total protein, PGE2, IL-Iß, TNF-α, C2C, and CTX-II. PGE2 and IL-1 ß rose sharply at 8 h, while TNF-α increased steadily through 8 h and 24 h, at that point; these three factors returned to the baseline level by 168 h. The time course of C2C and CTX-II concentrations peaked sharply at 24 h, and continued to be significant!) elevated over the baseline level even at 168 h. Injections of LPS into the joints led to a temporal inflammatory response, which in turn increased local release of inflammatory biomarkers and significantly altered the concentrations of cartilage markers in the synovial fluid.
The human ZNF300 gene is a member of the KRAB/C2H2 zinc finger gene family, the members of which are known to be involved in various developmental and pathological processes. Here, we show that the ZNF300 gene encodes a 68-kDa nuclear protein that binds DNA in a sequence-specific manner. The ZNF300 DNA binding site, C(t/a)GGGGG(c/g)G, was defined via a random oligonucleotide selection assay, and the DNA binding site was further confirmed by electrophoretic mobility shift assays. A potential ZNF300 binding site was found in the promoter region of the human IL-2Rβ gene. The results of electrophoretic mobility shift assays indicated that ZNF300 bound to the ZNF300 binding site in the IL-2Rβ promoter in vitro. Transient co-transfection assays showed that ZNF300 could activate the IL-2Rβ promoter, and that the activation was abrogated by the mutation of residues in the ZNF300 binding site. Identifying the DNA binding site and characterizing the transcriptional regulation property of ZNF300 would provide critical insights into its potential as a transcriptional regulator.
The objective of this study was to investigate the colour stability and lipid oxidation of beef under different packaging methods. The muscles longissimus lumborum were randomly packed in vacuum or modifi ed atmosphere packaging (MAP, 80% O2 , 20% CO2 ). Both packages were aged at 4°C for 7, 14 and 21 days. After each ageing time, samples were displayed in a refrigerator for 2, 4 and 6 days. Colour stability, lipid oxidation and their correlation were determined. Beef under vacuum packaging showed higher a* values on 7, 14, and 21 days of ageing and lower L* values on 14 and 21 days of ageing than beef in MAP (p<0.05). Lower a* values were observed in the samples packed in MAP, then displayed compared to samples packed in vacuum, then displayed after 21 days of ageing time on day 2, 4 and 6 of the display period (p<0.05). Thiobarbituric acid reactive substances (TBARS) increased signifi cantly in MAP compared to vacuum during 7, 14, and 21 days of ageing (p<0.05). An increase of TBARS was also observed during display after 14 and 21 days of ageing in samples packed in MAP, then displayed. Furthermore, a significant difference (p<0.05) was observed between samples packed in MAP and vacuum in peroxide value on 14 days of ageing. Lipid oxidation was observed mainly in the samples packed in MAP compared to vacuum, and positively correlated with results on colour stability.
Phosphate-solubilizing bacteria (PSB) increase phosphate bioavailability, thereby reducing the application frequency of chemical fertilizers in the production of Nicotiana tabacum (tobacco). In this study, PSB were isolated from tobacco plants for the first time. These PSB were screened in vitro for their ability to solubilize inorganic P (Pi) when grown in association with tobacco plants. Thirty-six PSB with the ability to solubilize Pi were isolated and screened for their indolyl-3-acetic acid and siderophore-producing capabilities. In addition, all 36 PSB strains had a partial fragment of their 16S rRNA gene sequenced. The analysis revealed high sequence identity to 16S rDNA sequences from Bacillus, Arthrobacter, Providencia, Enterobacter, Proteus, Psychrobacter, Serratia, Rhodococcus, Pseudomonas, Ochrobactrum, and Acinetobacter. Of the 36 PSB strains analyzed, three (Psychrobacter alimentarius HB15, Enterobacter ludwigii HB21, and Ochrobactrum haematophilum HB36) were selected for a controlled plant inoculation experiment. Inoculation of tobacco plants with these bacterial strains significantly increased plant dry weight. Additionally, inoculation increased P, K, and N uptake by tobacco seedlings as well as soil P availability. The increases observed with inoculation were even more pronounced when tricalcium phosphate (TCP) was added to the soil. The phosphate-solubilizing activity of these three strains was correlated with the release of gluconic, tartaric, acetic, and citric organic acids. Overall, co-inoculation of PSB and TCP appears to represent a promising option for increasing the yield of tobacco plants. The adoption of this technique could provide a pathway to reducing fertilizer input in agricultural settings.
The study was conducted on 24 Mongolian horses, with oligofructose-induced equine laminitis (10 g/kg b.w.). The objective of the study was to investigate the relationships among matrix metalloproteinase 2 (MMP-2), P38 mitogen-activated protein kinases (P38 MAPK), tissue inhibitor of metalloproteinase 2 (TIMP-2), lipopolysaccharides (LPS), and tumour necrosis factor-α (TNF-α) during acute developmental phase of laminitis, and to determine whether there are any characteristic tendencies. Moreover, plasma concentrations of LPS and TNF- α were measured in order to determine the time of leukocytes' activation. Eleven of the 12 horses showed clinical signs of laminitis. The contents of MMP-2 and P38 MAPK increased significantly from 8 h to 64 h, and the content of TIMP-2 decreased significantly at the same time. Plasma LPS concentrations increased significantly between 8 h and 20 h and reached a peak of 0.024 ± 0.009 EU/mL (equivalent to 3.04 ±1.19 pg/mL) at 12 h. TNF- α concentration increased between 20 h and 36 h. This data indicates that MMP-2 plays an important role during the early acute developmental phase of oligofructose-induced equine laminitis.
The measurement of D-3-hydroxybutyrate (D-BHBA) in milk samples is an important tool for diagnosis of subclinical/clinical ketosis in dairy cows. We describe a simple UV spectrophotometric method for measuring the concentration of D-BHBA in milk of dairy cows. From two herds, 119 milk samples were taken from dairy cows. The standard-curve equation was y = 0.2582x + 0.0269 (R² = 0.9967). The assay was highly specific with a minimum detection limit of 0.01 mmol/L and measuring range of up to 5 mmol/L. The recovery was between 99.35% and 100.22% and repeatability was 99.8%. The comparison between the spectrophotometric method and the fluorometric method revealed a close correlation (r = 0.9939). These results show that the spectrophotometric method can be successfully used as an alternative method to measure D-BHBA content in milk.
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