Interdependence Between Heat Solubility and Pyridinoline Contents of Squid Mantle Collagen

ABSTRACT: A considerable amount of squid mantle collagen, 45% to 70% of total collagen, was not solubilized even after 30 min of heating in boiling water with its fibrous structure left intact. Pyridinoline, one of the major intermo-lecular crosslinks in matured collagen, was more predominantly included in the insoluble collagen than in the soluble one (p < 0.05). These results suggest that pyridinoline is closely related to the heat solubility of squid collagen.     

SDS-聚丙烯酰胺垂直板状凝胶电泳鉴别不同食用肉类

应用SDS—聚丙烯酰胺垂直板状凝电泳方法,对猪、牛、鸡、鸭、鹅等5种畜禽和鲈鱼、鳜鱼、鳢鱼、青鱼、鲤鱼、草鱼、鮊鱼、鲫鱼、鳊鱼、鳙鱼、鳝鱼等11种鱼类的肌肉蛋白质进行分离鉴定.结果表明:由于不同种类动物肌肉蛋白质的组成不同、分子量不同,所以不同动物的肌肉蛋白质的电泳图谱明显不同,这主要表现在谱带的数目、位置及宽窄等方面,利用这一方法可以准确地区分、鉴定食用肉的种类,并为以后利用这一方法鉴定不同肉类提供了电泳图谱资料.     

四氢罂粟碱的合成工艺改进

以3,4-二甲氧基苯基乙腈为起始原料,经水解、缩合、合环、氢化等反应制得四氢罂粟碱,总收率67.8%,纯度96%以上(HPLC),工艺稳定,利于工业化生产。     

Investigation of metabolic myopathies by P-31 MRS using a standardized rest-exercise-recovery protocol: a survey of 800 explorations

A standardized P-31 magnetic resonance spectroscopy (MRS) protocol for the exploration of muscle metabolism by P-31 MRS in trained and untrained subjects as well as in patients with intolerance to exercise has been developed to meet the specific requirements of a clinical environment. This protocol is based on a short-term intense exercise which is very informative and well accepted by volunteers and patients. Invariant metabolic parameters have been established to characterize the normal metabolic response to the protocol. As a matter of fact, the comparative analysis of normal and diseased muscle remains a major requirement to further define metabolic events surrounding muscle contraction and the metabolic anomalies underlying diseases. Deviations from normality can be directly interpreted in terms of specific pathologies in some favourable cases. In most cases, P-31 MRS provides valuable information which has to be processed in conjunction with traditional invasive biochemical, electrophysiological and histoenzymological tests. For malignant and exertional hyperthermias, P-31 MRS constitutes a diagnostic tool with 100% sensitivity, as compared to contracture tests. P-31 MRS has proved particularly useful in the therapeutic follow-up of palliative therapies (coenzyme Q treatment of mitochondriopathies) and in family investigations. It is now an accepted diagnostic tool in the array of tests which are used to characterize muscle disorders in clinical routine. This procedure is already approved for reimbursement in the public hospital system in Marseille, France.     

A Compositional Framework for Developing Parallel Programs on Two-Dimensional Arrays

Computations on two-dimensional arrays such as matrices and images are one of the most fundamental and ubiquitous things in computational science and its vast application areas, but development of efficient parallel programs on two-dimensional arrays is known to be hard. In this paper, we propose a compositional framework that supports users, even with little knowledge about parallel machines, to develop both correct and efficient parallel programs on dense two-dimensional arrays systematically. The key feature of our framework is a novel use of the abide-tree representation of two-dimensional arrays. The presentation not only inherits the advantages of tree representations of matrices where recursive blocked algorithms can be defined to achieve better performance, but also supports transformational development of parallel programs and architecture-independent implementation owing to its solid theoretical foundation – the theory of constructive algorithmics.     

Unlockable knee joint mechanism for powered gait orthosis

Walking with the knee joint locked increases the amplitude of pelvic tilt and results in an unnatural gait. This paper introduces a powered gait orthosis with a moveable knee joint designed to improve the gait speed of patients with spinal cord injury (SCI). The unlockable knee joint powered gait orthosis (UKJ-PGO) uses a gas spring cylinder and a solenoid locking device to enable flexion of the joint, while the rigidity of the hip-joint device is enhanced using air muscles. A gait analysis was conducted to evaluate the performance of the UKJ-PGO, and the kinematic parameters obtained were compared with those of a standard PGO. In the gait of SCI patients using the UKJ-PGO, the new knee-joint device enabled flexion during the swing phase and showed a decrease in pelvic tilt compared with the standard PGO gait. As greater flexion was possible at the knee joint, the duration of the stance phase substantially decreased to near to the normal value, and the duration of the swing phase increased accordingly. In addition, the gait using the UKJ-PGO was faster than that with the standard PGO.     

Thawing, Refreezing and Frozen Storage Effects on Muscle Functionality and Sensory Attributes of Frozen Cod (Gadus morhua)

Thawing and re-freezing of cod fillet blocks did not necessarily result in greater deterioration (relative to a ‘once frozen’ control) of cooked fish sensory attributes after 9 months frozen storage at –22°C. Thawed and refrozen fish muscle displayed a faster decline in myofibril protein solubility than once frozen controls and had reduced water-holding capacity but analysis of proton spin-spin relaxation times indicated no change in water location. The decline in protein solubility was not caused by complete protein unfolding. Long thawing times (30 hr) before re-freezing and storage resulted in cooked fish with more gray appearance and more stale flavor. Changes in fish muscle functionality did not enable direct inference of sensory attributes.     

Species dependence of fish myosin stability to heat and frozen storage

The thermal stabilities of the proteins of a range of fish muscles of different habitat temperatures were determined by differential scanning calorimetry before and after frozen storage at 20°C.
In whole muscle a clear relationship was seen between habitat temperature and the thermal denaturation of myosin, which persisted when isolated myosins were analysed under conditions close to physiological pH and ionic strength. the ionic environment of the myosin molecules in the whole tissue will, however, not be exactly the same as in the myosin solution.
No significant correlations were seen between habitat temperature, ultimate pH and other analytical parameters.
After frozen storage, the myosin transitions in red snapper, a warm water species, was markedly changed in whole muscle but not in isolated myosin, suggesting the post mortem development of an interaction with other muscle proteins. In contrast, in cod, a cold water species, changes in myosin transitions were very similar, both in whole muscle and isolated myosin.
The implications of species differences in the 'melting' of myosin domains and changes in textural quality during frozen storage are discussed briefly.     

Capillary Zone Electrophoresis of Fish Muscle Sarcoplasmic Proteins

A capillary zone electrophoresis (CZE) method for rapid separation of fish muscle sarcoplasmic proteins (SAJR) was developed using a highionic-strength phosphate buffer and an untreated, fused silica capillary (20 μm i.d. X 20 cm). Changes in pH between 6.6-7.5 resulted in differences in mobility, separation factors, and number of SAR moieties. An optimal SAR profile was obtained at pH 7.4. When used to monitor frozen storage changes in SAR from cod (Atlantic, Ling, Pacific) and pollock fillets, the procedure indicated both species differences and low-and high- molecular-weight frozen storage changes. CZE is an effective screening/quantification alternative to conventional electrophoresis and/ or HPLC because it is fast (<10 min), simple, sensitive, precise, and readily automated.     

Toxic and essential metals in liver, kidney and muscle of pigs at slaughter in Galicia, north-west Spain

The aims of the study were to evaluate toxic and essential metal concentrations in meat and offal from pigs in north-west Spain to compare these with reported metal concentrations in pigs in other countries and in cattle in this region, and to relate the observed concentrations to maximum acceptable concentrations. Samples from 63 pigs aged 6 months were randomly collected at slaughter. After acid digestion, levels of metals were determined by ICP-OES and ICP-MS. As regards the toxic metals, mean concentrations in liver, kidney and muscle were 0.073, 0.308 and 0.009 mg kg^-1 fresh weight for cadmium, 0.004, 0.008 and 0.003 mg kg^-1 for lead, 0.013, 0.011 and 0.003 mg kg^-1 for arsenic, and 0.001, 0.002 and 0.001 mg kg^-1 for mercury. These concentrations can be considered low, and in general similar to those reported in similar studies in recent years. In addition, maximum admissible concentrations established by the European Union were not exceeded in any sample. As regards the essential metals, concentrations in liver, kidney and muscle were 14.9, 5.63 and 6.85 mg kg^-1 for copper, 81.3, 28.9 and 42.5 mg kg^-1 for zinc, 195, 51.6 and 26.5 mg kg^-1 for iron; 1.17, 2.51 and 0.656 mg kg^-1 for selenium, 3.32, 1.56 and 1.01 mg kg^-1 for manganese, 0.023, 0.027 and 0.003 mg kg^-1 for cobalt, 0.120, 0.077 and 0.131 mg kg^-1 for chromium, 0.009, 0.027 and 0.026 mg kg^-1 for nickel, and 1.62, 0.683 and 0.140 mg kg^-1 for molybdenum. These concentrations are all within the accepted adequate-safe ranges for this animal species, and in general are in line with those previously reported in the literature.