Spoilage potential of psychrotrophic bacteria isolated from raw milk and the thermo-stability of their enzymes / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

The storage and transportation of raw milk at low temperatures promote the growth of psychrotrophic bacteria and the production of thermo-stable enzymes, which pose great threats to the quality and shelf-life of dairy products. Though many studies have been carried out on the spoilage potential of psychrotrophic bacteria and the thermo-stabilities of the enzymes they produce, further detailed studies are needed to devise an effective strategy to avoid dairy spoilage. The purpose of this study was to explore the spoilage potential of psychrotrophic bacteria from Chinese raw milk samples at both room temperature (28 °C) and refrigerated temperature (7 °C). Species of Yersinia, Pseudomonas, Serratia, and Chryseobacterium showed high proteolytic activity. The highest proteolytic activity was shown by Yersinia intermedia followed by Pseudomonas fluorescens (d). Lipolytic activity was high in isolates of Acinetobacter, and the highest in Acinetobacter guillouiae. Certain isolates showed positive β-galactosidase and phospholipase activity. Strains belonging to the same species sometimes showed markedly different phenotypic characteristics. Proteases and lipases produced by psychrotrophic bacteria retained activity after heat treatment at 70, 80, or 90 °C, and proteases appeared to be more heat-stable than lipases. For these reasons, thermo-stable spoilage enzymes produced by a high number of psychrotrophic bacterial isolates from raw milk are of major concern to the dairy industry. The results of this study provide valuable data about the spoilage potential of bacterial strains in raw milk and the thermal resistance of the enzymes they produce.

Informed consent from uninformed patients: a dilemma

To assess the amount of information provided pre-operatively by the doctors/nurses to the patients undergoing surgery and to relate understanding of this information with the educational status of the patient and their anxiety levels. Descriptive study. Surgical Units of Jinnah Postgraduate Medical Centre, Karachi, From November 2012 to April 2013. A set of standardized questions were asked relating to patient's knowledge about the informed consent process, their education level and its impact on the understanding of informed consent as well as the impact of language of the consent form on the patient's interpretation of the information provided. Out of 291 patients, 168[58.1%] patients signed the consent form themselves. Two hundred eight two [96.9%] patients were aware of the type of surgery they had to undergo. Two hundred and nine [71%] patients knew that it was their legal right to have their consent taken by the doctor before any surgery. Fifty six patients understood the consent form completely. Out of 56 patients who understood the consent form, 39 individuals had an education level of at or above matriculation. Thirty three consents were taken by operating surgeon or residents that significantly decreased the anxiety level. Most of the patients were aware of the importance of consent process as their legal right. High education level improved the understanding of the process

Role of mechanical factors in the evaluation of pedicle screw type spinal fixation devices.

Prior to implantation, spinal implants are subjected to rigorous testing to ensure safety and efficacy. A full battery of tests for the devices may include many steps ranging from biocompatibility tests to in vivo animal studies. This paper describes some of the essential tests from a mechanical engineering perspective (e.g., motion, load sharing, bench type tests, and finite element model analyses). These protocols reflect the research experience of the past decade or so.