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971.
醋酸/水分离研究进展 总被引:8,自引:0,他引:8
醋酸是一种重要的化工原料,其水溶液广泛存在于各类工业过程中,由于醋酸/水体系的相对挥发度不大,生产中用于分离醋酸/水的普通精馏和共沸精馏工艺能耗较高,因此研究者和工业界都在寻求更好的分离方法,目前醋酸/水的分离方法有精馏法、萃取法、醋化法、中和法、吸附法、膜分离法等,其中有些方法已经工业化,具有成熟的生产工艺;有些则处于研究阶段,本文对这些方法的研究现状及应用前景进行了介绍和评述,提出了萃取精馏法将是一很有前途的分离方法。 相似文献
972.
对α-亚麻酸及其乙酯分别在氧气气氛和氮气气氛下进行一定剂量的γ-辐射,每隔两天测定其过氧化值。研究结果表明:辐射剂量和时间对亚麻酸的过氧化值有较大影响,本文同时探讨了亚麻酸在γ-辐射下过氧化值与反应机制之间的内在联系。 相似文献
973.
Miriam Varkey R. Sundara Devi Shrinivas B. Rao 《Indian journal of clinical biochemistry : IJCB》1997,12(1):63-66
The levels of total sialic acid, lipid bound sialic acid and fucose were estimated in the sera of patients with benign and
malignant tumours of breast. An increase was noted in all the three parameters, with a more marked increase in malignancy,
when compared with benign and controls. Consequent to surgery, there was an elevation in the serum levels of the above parameters
than the values prior to surgery and a decline was noted two months after surgery although none of the values reached the
normal range. These results suggest a close association of the glycoproteins with the tumour burden and further signify their
role in early detection and staging of cancer breast. 相似文献
974.
975.
976.
Liu WM Lai SJ Lu LZ Shi FX Zhang J Liu Y Yu B Tao ZR Shen JD Li GQ Wang DQ Li JJ Tian Y 《Journal of Zhejiang University. Science. B》2011,12(9):736-743
The effects of different fatty acid (FA) contents in diet on serum parameters, FA compositions of eggs and meat, and liver morphological changes were studied in Shaoxing laying ducks. A total of 264 ducks at 17 weeks were fed a control diet or a diet containing 30 g/kg fish oil (FO), 25 g/kg sunflower oil (SO), or 30 g/kg palm oil with 20 g/kg beef tallow (PBO). Malondialdehyde (MDA) content in the liver and the serum of ducks fed the PBO diet was significantly (P<0.05) higher than that of ducks fed the other diets. Triglyceride (TG) and total cholesterol (TC) levels were significantly lower (P<0.05) in ducks fed the FO diet. Serum TC also was lower in ducks fed the SO diet. Superoxide dismutase (SOD) activity was also affected by diets. The contents of polyunsaturated FAs (PUFAs) in eggs and meat were significantly higher (P<0.001) in ducks fed the FO and SO diets than in ducks fed the control diet. The level of C22:6 (n-3) FA in ducks fed the FO diet was significantly higher than that in ducks fed the other diets. However, the conversion efficiency of the longer-chain C20:5 (n-3) FA was higher than that of C22:6 (n-3). Ducks fed the PBO diet exhibited lipid droplet accumulation in the liver. These results demonstrate that a diet enriched with different FAs has strong effects on serum lipid levels and the deposition of PUFAs into tissue lipids. 相似文献
977.
We hypothesized whether systemic administration of high-molecular-weight hyaluronic acid (HMW HA) could rescue trinitrobenzene
sulfonic acid (TNBS)-induced colitis through Toll-like receptor 4 (TLR4) signal. C3H/HeN mice and C3H/HeJ mice were used.
Mice were divided into four groups: control, 50% ethanol treatment group, TNBS treatment group, and TNBS plus HA treatment
group. The weight changes, clinical scores, macroscopic scores, and histological scores were recorded. Cyclooxygenase 2 (Cox-2)
and prostaglandin E2 (PGE2) expressions were measured both in colons and peritoneal macrophages from these mice. HA was a rescue therapy for the colitis
induced by TNBS only in C3H/HeN mice. The clinical score, macroscopic score, and histological score were much lower in C3H/HeN
mice receiving TNBS plus HA treatment. Cox-2 and PGE2 expressions only increased in C3H/HeN mice. These Cox-2 expressing cells were macrophages. HA can also promote the production
of Cox-2 and PGE2 in peritoneal macrophages from C3H/HeN mice. Our data demonstrated that HMW HA can rescue TNBS-induced colitis through inducing
Cox-2 and PGE2 expressions in a TLR4-dependent way. Macrophages may be the effector cells of HMW HA. 相似文献
978.
Liu P Shen SR Ruan H Zhou Q Ma LL He GQ 《Journal of Zhejiang University. Science. B》2011,12(11):923-930
Naturally fermented pickles harbour many lactic acid bacteria (LAB). Forty-three LAB strains with conjugated linoleic acid
(CLA)-producing ability were isolated from three naturally fermented pickle brines. Of these isolates, lp15 identified as
Lactobacillus plantarum by API 50 CHL system and full-length 16S rDNA sequence analysis exhibited the highest CLA-producing ability (26.1% conversion)
at 48 h in de Man Rogosa Sharpe (MRS) broth in the presence of 100 μg/ml of linoleic acid (LA). Compared to other strains,
L. plantarum strain lp15 showed the highest tolerance upon increased levels of LA in the medium, i.e., up to 600 μg/ml. This strain converted
about 25% of LA into CLA isomers [predominantly cis-9, trans-11 CLA (9-CLA) and trans-10, cis-12 CLA (10-CLA)], of which 75% was 9-CLA. Interestingly, though the conversion rate of LA into CLA by lp15 remained stable
between 100 to 600 μg/ml LA levels in the medium, it dropped sharply at 1000 μg/ml. Taken together, the lp15 strain displayed
relatively high LA tolerance with higher conversion rate, which implies that this strain is a valuable candidate for enhancing
the CLA content in food-sources like pickles. 相似文献
979.
980.
选用4个材料亲本,按4×4NCⅡ完全双列杂交设计,配制了12个组合,对小麦植酸含量的杂种优势及其遗传力进行了研究。结果表明,偃展4110X淮麦20的中亲优势和超低亲优势最大,偃展4110×CN8081的中亲优势最小,CN8081×小偃986的超低亲优势最小;淮麦20的一般配合力效应值最大,小偃986的特殊配合力效应值最小;植酸的广义遗传力为85.9%,狭义遗传力为32.3%。 相似文献