出口冻猪分割肉血冰的形成及消除的试验研究

我国出口冻猪分割肉已有十余年的历史,它是在出口冻猪白条肉的基础上发展起来的去皮、去骨、去肥膘的产品。除出口香港及东南亚一些国家外,还销售至远洋各国。但是一直未解决成品中有血冰存在的问题。

The changes of three components in coelomic fluid of Urechis unicinctus exposed to different concentrations of sulfide

The changes in heme (associated with hemoglobin), hemoglobin and hematin in the coelomic fluid of marine worm, Urechis unicinctus, exposed to different concentrations of sulfide, were investigated using bio- chemical techniques. When exposed to different sulfide concentrations for up to 96 h, the relative amounts of the three components changed in a regular pattern suggesting that the coelomocytes play an important role in the worm’s tolerance to sulfide. The possible roles of heme compounds in sulfide tolerance of this species are dis- cussed on the basis of our experimental data.

Chemical Characteristics and Anticoagulant Activities of Two Sulfated Polysaccharides from Enteromorpha linza (Chlorophyta)

Two sulfated polysaccharides, designated MP and SP, were extracted from the marine green alga Enteromorpha linza using hot water and then purified using ion-exchange and size-exclusion chromatography. The anticoagulant activities of MP and SP were examined by determination of their activated partial thromboplastin time （APTT）, thrombin time （TT） and prothrombin time （PT） using human plasma. Results showed that MP and SP were composed of abundant rhamnose with small amounts of xylose and glucuronic acid, whereas SP also contained a small amount of galactose. Approximate molecular weights of MP and SP were 535 and 502 kDa, respectively. As compared with SP, MP had higher contents of sulfate ester （19.0%） and uronic acid （14.9%）. The MP mainly consisted of （1→4）-linked rhamnose residues with partially sulfated groups at the C-3 position, and small amounts of （1→3, 4）-linked rhamnose, （1→2,4）-linked rhamnose, （1→4）-linked glucuronic acid and （1→4）-linked xylose residues. The SP contained abundant （1→4）-linked rhamnose with minor amounts of （1→3）-linked rhanmose, （1→3, 4）-linked rhamnose, （1→2, 4）-linked rhanmose, （1→4）4inked glucuronic acid, （1→4）-linked xylose, and （1→3）-linked galactose residues. The sulfate groups were mainly located at C-3 of （1→4）-linked rhamnose residues. Both MP and SP, in particular the former, effectively prolonged APTT and TT. This work demonstrates that MP and SP have unique structural characteristics distinct from those of other sulfated polysaccharides from Enteromorpha. The MP is a potential source of anticoagulant, and the difference in anticoagulant activities of the two sulfated polysaccharides is directly linked to the discrepancy of their chemical features.

Antiangiogenic activity of low-temperature lysozyme from a marine bacterium in vivo and in vitro

We extracted marine low-temperature lysozyme (MLTL),a novel lysozyme,from a marine microorganism through fermentation.Our previous study suggested that a low molecular weight (16 kDa) may exert anti-tumor activity through antiangiogenesis.In this study,we extracted a high weight (39 kDa) and investigated its antiangiogenic activity in vivo and in vitro.Using zebrafish embryos as an in vivo study model,we found that treatment with MLTL significantly inhibited the growth of subintestinal vessels (SIVs) in a dose-dependent manner and that 400 μg/ml MLTL was sufficient to block the growth of SIVs.An in vitro study conducted using human umbilical vein endothelial cells (HUVECs) revealed that MLTL suppressed the proliferation,migration and tube formation of HUVECs in a dose-dependent manner.Interestingly,assays by flow cytometry and DNA electrophoresis indicated that MLTL was able to induce apoptosis of HUVECs.Moreover,further study demonstrated that the disruption of intracellular Ca2+ homeostasis may play an important role in MLTL induced apoptosis of HUVECs.Taken together,the results of this study demonstrate for the first time that MLTL inhibits angiogenesis through its pleiotropic effects on vascular endothelial cells and induces apoptosis through regulation of cellular Ca2+ levels.The results of this study also revealed a possible mechanism underlying the antiangiogenic effect of MLTL and suggested that MLTL may be a promising new antiangiogenic agent for use in cancer therapy.

Comparison of Antioxidant Activity and Antioxidant Components in Lettuce, Onion and Tomato Obtained with Different Levels and Forms of Nitrogen Fertilization

The effect of N levels and sources on the antioxidant components in vegetable is not completely understood. Therefore, greenhouse experiments were conducted to determine the changes in antioxidant capacity diphenyl-2-picrylhydrazyl （DPPH） and ferric reducing antioxidant power （FRAP）, total phenolics, ascorbic acid, total carotene and lycopene contents in edible portions of lettuce, onion and tomato due to different nitrogen levels and sources. The experiment included three N levels （20, 40 and 60 kg/ha for lettuce trial and 60, 120 and 180 kg/ha for either onion or tomato） and four nitrogen sources （calcium nitrate, ammonium sulphate, ammonium nitrate and urea）. The antioxidant capacity and phenolic contents in lettuce was enhanced under low nitrogen level, while the antioxidant capacities, phenolics, carotenoids and lycopene in tomato fruits were not significantly affected by the nitrogen dose applied. Application of calcium nitrate caused 50% increase in DPPH and 20% in FRAP of lettuce compared to other nitrogen forms. Tomato treated with calcium nitrate or ammonium sulphate had higher phenolic and ascorbic acid contents than treated plants with ammonium nitrate or urea. Antioxidant tested parameters of onion were not significantly affected by the nitrogen treatments. Nitrogen concentration in tomato fruits significantly correlated with FRAP antioxidant capacity, phenolics, ascorbic acid, carotene and lycopene contents.

In Vitro Study of Photodynamic Therapy for Treatment of Bacteremia in Whole Blood

Antibiotic resistance has been compromised hospitalized patients with serious infections. The main cases of bacteremia can be caused by antibiotic resistant pathogens. Photodynamic therapy （PDT） has been shown as an alternative for inactivation of microorganisms in blood. In this therapy photochemical mechanisms occur that may prevent the development of bacteria. This study aims optimization of PDT parameters for blood decontamination. Concentration ofphotosensitizer （PS）, light dose （LD） and incubation time （IT） were studied for hemolysis and cell toxic effects. It was observed that PDT can be used for microbial inactivation in total blood reducing 0.85 log10 CFU/mL ofS. aureus at 15 J/cm^2 and 50μg/mL of Photogem .

Pyrite morphology and episodic euxinia of the Ediacaran Doushantuo Formation in South China

The Ediacaran Doushantuo Formation with well-preserved fossil record in South China provides a rare window for our understanding of biological evolution,global carbon cycle,and oceanic redox states.Prominent negativeδ^(13)C anomalies(i.e.,the Shuram excursion)in Ediacaran successions worldwide fundamentally challenge the traditional models of isotopic mass balance.Additionally,conflicting opinions of both oxic and anoxic conditions have been proposed for the deep waters during this period.Here,we present a detailed study of pyrite morphology and carbonate carbon isotope data documented from drill core samples at Songtao County,northeastern Guizhou.Framboid aggregates are the dominant pyrite form in black shale and they can transfer to euhedral crystals through continuous growth of the constituent microcrystals.A positive correlation between microcrystal sizes(d)and framboid diameters(D)is observed,while the different D/d ratios of framboids in argillaceous dolostone and black shale reflect different substrate availability.Electron microprobe analyses reveal no consistent compositional patterns between framboidal and euhedral pyrites.Framboid size distributions of the investigated drill core,in combination with previously published redox data from the intra-shelf Jiulongwan section,shelf margin Zhongling section,and lower slope Wuhe section,suggest that three episodes of marine euxinia have been established throughout the deposition of the Doushantuo Formation.The time lag between the uppermost euxinic interval and the Shuram excursion may arise from the depression of sulfate reduction maintained by other oxidants.

Treatment of Herpes Zoster with Electroacupuncture plus Collateral-pricking and Cupping Therapy

Objective： To observe the clinical effect of electroacupuncture （EA） plus collateral-pricking and cupping therapy for herpes zoster. Methods： Fifty-three cases with herpes zoster were randomly divided into two groups. Thirty-one cases in the treatment group were treated with EA at Jiaji （EX-B 2） points plus local collateral-pricking and cupping therapy. Twenty-two cases in the control group were treated with oral administration of VaLacido~;ir Hvdrochloride and Indomethaci~. Results： The curative and remarkable effective rate was 93.5% in the treatment group and 72.7% in the control group. The difference between the two groups was statistically significant （P〈0.01）, indicating that EA plus collateral-pricking and cupping therapy is better than Western medications in the clinical effects for herpes zoster. Conclusion： The EA plus collateral-pricking and cupping method is an effective therapy for herpes zoster.