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排序方式: 共有136条查询结果,搜索用时 15 毫秒
41.
Tattersall M Engineer N Khanjani S Sooranna SR Roberts VH Grigsby PL Liang Z Myatt L Johnson MR 《Reproduction (Cambridge, England)》2008,135(4):569-579
Preterm labour (PTL) is the most important cause of neonatal morbidity and mortality. While some causes have been identified, the mechanisms involved remain elusive. This study investigates whether term labour (TL) is an appropriate model for PTL by examining pro-labour gene expression, using quantitative rtPCR, and protein synthesis, using Western analysis, in preterm and term myometrial samples obtained from the upper and lower uterine segments before and after the onset of labour. In the lower segment, the levels of prostaglandin H synthase type-2 (PGHS-2), interleukin-1beta (IL-1beta), IL-6 and IL-8 mRNA expression were significantly higher in TL compared with PTL samples. Compared with non-labour controls, the expression of IL-1beta and IL-8 mRNA was increased in both PTL and TL samples and the expression of PGHS-2 and IL-6 mRNA was increased in TL samples only. In the upper segment, there were no differences between PTL and TL samples and the mRNA expression of PGHS-2 and IL-1beta was increased in TL compared with term no labour samples. No effect of PTL or TL was seen on either oxytocin receptor or connexin-43 mRNA expression or protein levels. The multiple regression analysis and studies in primary cultures of uterine myocytes suggest that the inflammatory cytokines, IL-1beta and tumour necrosis factor-alpha, are the most important regulators of PGHS-2 and IL-8. Our data show that preterm and term labouring myometrium are significantly different and that the most marked labour-induced changes in gene expression are in the lower segment. These changes may occur in response to the release of inflammatory cytokines by the labour-associated inflammatory infiltration. 相似文献
42.
This paper presents a new scheme to integrate the declarative approach to graphics and object-oriented data modelling techniques to form a fruitful symbiosis for constraint-based graphics database systems. It has rich modelling constructs to describe graphics data and allows sharing of representation. It also provides useful mechanisms for management of integrity constraints. We have also identified important classes of constraints in the context of object-oriented graphics database systems. Examples are given for maintenance of constraints at the time of insertion, deletion and modification. 相似文献
43.
Whey fermentation of various rice and bengal gram dhal blends prepared by mixing them in different proportions at 35 °C for 18 h brought about a significant decline in phytic acid content. Phytic acid content in various blends decreased to the extent of 23 to 36 per cent over the control values. Whey incorporation as well as fermentation improved the starch and protein digestibility (in vitro) of all the rice-bengal gram dhal mixtures. Improvement in starch and protein digestibility is related to the reduction in phytic acid content, as this antinutrient is known to inhibit amylolysis and proteolysis. A significant negative correlation found between phytic acid and digestibility of starch and protein strengthens our findings. 相似文献
44.
Josiah J Bonire Neelam N S Jalil Joseph A Lori 《Journal of the science of food and agriculture》1991,57(3):431-435
The determination by atomic absorption spectroscopy of the iron, nickel, copper, zinc and cadmium content of two cultivars of white yam (Dioscorea rotundata Pair) and their source soil from three farms, and also of random samples of the cultivars from five geographical areas in Kaduna and Plateau states of Nigeria, is reported. The analyses show all the metals except Fe to be in trace amounts in the tissues of both cultivars; the barks contain two to four times more. The iron content was found to be about 20 times higher in the bark than in the tissue. Less than 0.7% of the metals present in the soil could be extracted with NH4NO3 solution. Yam bark, which contains reasonable amounts of the above metals, could be useful as cattle feed. Yam tissue, having a high content of Zn compared with Cd, could be recommended for the diet of hypertensive patients. 相似文献
45.
Nakshatra B. Singh Sarita Rai Neelam Singh 《Journal of the American Ceramic Society》2002,85(9):2171-2176
Calcium silicate hydrate was prepared by hydrothermal reaction between calcium oxide and silica (C/S = 2.0) at a temperature of 205°–215°C and a pressure of 17–19 bar. This reaction with decomposition at 900°C produced highly reactive β-dicalcium silicate (specific surface area 4.55 m2 /g) contaminated with small amounts of wollastonite as an impurity. Infrared spectral studies have shown that β-dicalcium silicate prepared at 900°C is less symmetric compared with the control prepared at 1450°C using boron trioxide as a stabilizer. The specific surface area of β-dicalcium silicate decreased with temperature. The hydration studies were done by determining the nonevaporable water, calcium hydroxide (CH) contents, and specific surface area of the hydrated samples. X-ray diffraction studies were also done. The results showed that prepared β-dicalcium silicate is highly reactive. Calcium chloride (1.0 wt%) and gypsum retard the hydration. Possible causes of high reactivity have been discussed. 相似文献
46.
Single-strand conformation polymorphism (SSCP) showed 7 and 5 haplotypes in caprine GH gene exon-4 and exon-5 in Black Bengal, a prolific meat breed from India. All haplotypes revealed novel sequences. In exon-4 codons 6, 36 and 54 were polymorphic. At codon 6, AA arginine (R) changed to histidine (H) and proline (P), showing 6RR, 6HH and 6PP genotypes. At codons 36 three genotypes DD, VV and DV were observed due to SNP showing changed from aspartic acid (D) to valine (V). At codon 54, AA change from arginine to tryptophan (W) and 54RR and 54WW genotypes were observed. SNPs were also observed at codon 23 (serine to threonine) and at 37 (arginine to proline) in 8% of goats. In exon-5 nucleotide substitution (G/A) at codon 10 and (A/G) at 14 respectively changed AA from glycine (K) to glutamic acid (E). Silent mutations were also observed. 相似文献
47.
Farheen Gul Khafsa Malik Rahmatullah Qureshi Mushtaq Ahmad Lubna Ansari Muhammad Zafar Sabtain Hussain Sidra Khalid Muhammad Imran Neelam Rashid 《Microscopy research and technique》2022,85(4):1392-1409
The current study aimed to investigate the palyno-morphological features of Asteraceous species from District Dera Ismail Khan, Khyber Pakhtunkhwa, Pakistan. A total of 13 species were collected, pressed, identified, and examined by using light and scanning electron microscopy. Both qualitative and quantitative pollen characters were observed, that is, equatorial and polar diameter, number of pores and colpi, exine thickness, exine sculpturing, pollen shape, and P/E ratio. Pollen shapes observed in studied taxa were spheroidal, suboblate, oblate-spheroidal, and lophate-spheroidal. The aperturation patterns of pollens vary from tricolporate to tetracolporate. The maximum polar and equatorial diameter of 75–100 (87.5 ± 13.6) μm and 87.5–117.5 (102.5 ± 16.4) μm, respectively, was recorded in Echinops echinatus, while minimum polar and equatorial diameter of 20–22.5 (21 ± 1.36) μm and 22.5–25 (23.5 ± 1.36) μm, respectively, was recorded in Aster subulatus. Six types of exine sculpturing patterns were observed; echinate, micro-echinate, echinate-microreticulate, microreticulate, echinate-perforate, and scabrate. Maximum exine thickness of 8.75 μm was recorded in E. echinatus and minimum of 1.25 μm in Launaea mucronata. The pollen morphology has valuable significance in understanding the taxonomy of different plant groups and plays a central role in the correct identification and classification of Asteraceous flora at species, generic, and tribe levels. 相似文献
48.
GE Tillman JL Wasilenko M Simmons TA Lauze J Minicozzi BB Oakley N Narang P Fratamico AC Cray 《Journal of food protection》2012,75(9):1548-1554
It is estimated that at least 70% of human illnesses due to non-O157 Shiga toxin-producing Escherichia coli (STEC) in the United States are caused by strains from the top six serogroups (O26, O45, O103, O111, O121, and O145). Procedures for isolating STEC from food products often use plating media that include antimicrobial supplements at concentrations that inhibit background microflora growth but can also inhibit target STEC growth. In this study, an agar medium with lower supplement concentrations, modified Rainbow agar (mRBA), was evaluated for recovery of STEC serogroups O26, O45, O103, O111, O121, and O145 from ground beef enrichments. A post-immunomagnetic separation (IMS) acid treatment step was additionally used to reduce background microflora and increase recovery of target STEC strains. Ground beef samples (325 g) were artificially contaminated with STEC and confounding organisms and enriched for 15 h. Recovery of the target STEC was attempted on the enrichments using IMS and plating onto mRBA and Rainbow agar (RBA). Additionally, acid treatment was performed on the post-IMS eluate followed by plating onto mRBA. Using the combination of mRBA and acid treatment, target STEC were isolated from 103 (85.8%) of 120 of the low-inoculated samples (1 to 5 CFU/325-g sample) compared with 68 (56.7%) of 120 using no acid treatment and plating onto RBA with higher levels of novobiocin and potassium tellurite. The combination of acid treatment and mRBA provides a significant improvement over the use of RBA for isolation of STEC serogroups O26, O45, O103, O111, O121, and O145 from raw ground beef. 相似文献
49.
Latex agglutination assays for detection of non-O157 Shiga toxin-producing Escherichia coli serogroups O26, O45, O103, O111, O121, and O145 总被引:1,自引:0,他引:1
Medina MB Shelver WL Fratamico PM Fortis L Tillman G Narang N Cray WC Esteban E Debroy A 《Journal of food protection》2012,75(5):819-826
Latex agglutination assays utilizing polyclonal antibodies were developed for the top six non-O157 Shiga toxin-producing Escherichia coli (STEC) serogroups. Rabbit antisera were affinity purified through protein A/G columns, and the isolated immunoglobulins (IgGs) were covalently immobilized onto polystyrene latex particles. The resulting latex-IgG complex had a protein (IgG) load of 0.20 to 0.28 mg/ml in a 1% latex suspension. Optimum conditions for the agglutination assay consisted of utilizing 20 μm l of latex-IgG reagent containing 2.0 to 2.8 μm g IgG in a 0.5% latex suspension. Agglutination or flocculation was observed almost instantly after mixing the colonies with the latex-IgG, indicating STEC strains. More than 100 target and nontarget strains were tested in more than 3,000 test replicates. All target organisms produced positive results, but three antisera (anti-O26, anti-O103, and anti-O145) cross-reacted with some other STECs. The anti-O103 and anti-O145 latex reagents cross-reacted with O26 strains, and the anti-O26 cross-reacted with O103 strains. The latex-IgG reagents are stable for at least 1 year and are easy to prepare. These agglutination assays can be used for identification of presumptive non-O157 STEC colonies from agar media. The techniques used to prepare the latex reagents also can be utilized for testing other STEC serogroups, other E. coli serotypes, or other pathogens to ensure safe foods to consumers. 相似文献
50.
Neelam Kumari S. B. Krupanidhi K. B. R. Varma 《Journal of Materials Science: Materials in Electronics》2010,21(11):1107-1114
Bismuth vanadate (BVO) thin films were fabricated on indium tin oxide (ITO) coated glass substrates using pulsed laser ablation
technique and investigated their structural, optical and electrical properties. The use of the indium tin oxide coated glass
substrate resulted in reducing the leakage current characteristics of crystalline BVO thin films. The X-ray diffraction (XRD)
studies confirmed the monophasic nature of the post annealed (500 °C/1 h) films. The atomic force microscopy indicated the
homogeneous distribution of crystallites in the as-deposited films. The as-deposited and the post annealed films were almost
90% transparent (380–900 nm) as confirmed by optical transmission studies. Dielectric constant of around 52 was attained accompanied
by the low dielectric loss of 0.002 at 10 kHz for post annealed films. The leakage current of the post annealed BVO films
on ITO coated glass substrates measured at room temperature was 8.1 × 10−8 A at an applied electric field of 33 kV/cm, which was lower than that of the films with platinum and SrRuO3 as the bottom electrodes. 相似文献