Genetically engineered organisms for bioremediation of pollutants in contaminated sites

Environmental pollution is a major problem which affects biodiversity, public health and ecosystems worldwide. This issue cannot currently be solved using conventional technology because these treatments are expensive, ineffective and time consuming. Conventional methods focus unduly on the separation, rather than the destruction of contaminants. The use of genetically engi- neered organisms for bioremediation would be an envi- ronmentally-friendly and cost-effective alternative for the management and remediation of pollutants in contaminated sites. Different types of genetically engineered microbes have been developed through recombinant DNA and RNA technologies, these have been utilized for the removal of heavy metals and toxic substances from contaminated sites. Transgenic plants can also mobilize or degrade chlorinated solvent, xenobiotic compounds, explosives and phenolic substances. A symbiotic relationship between genetic engineered microbes and transgenic plants can enhance the effectiveness of bioremediation of contaminated sites. This review examines recent developments in the use of genetically engineered microbes and transgenic plants forthe bioremediation of contaminated sites. This review will also identify the environmental factors which influence bioremediation by genetically engineered microbes and transgenic plants as well as suggesting future directions for research in these areas.     

Microsoft C 与 MASM 混合编程的研究

讨论了Microsoft C语言中调用MASM 5．0汇编语言程序的方法，并针对一些易出现的问题，如程序接口部分的要求，C语言与汇编程序间参数的传递，寄存器的使用等，提出了解决办法．     

Perusing Piezoelectric Head Performance in a New 3-D Printing Design

Rapid prototyping (RP) is a computerized fabrication technology that additively builds highly complex three-dimensional physical objects layer by layer using data generated by computer, for example CAD or digital graphic. Three-dimensional printing (3DP) is one of such technologies that employ ink-jet printing technology for processing powder materials. During fabrication, a printer head is used to print a liquid on to thin layers of powder following the object’s profile as generated by the system computer. This work looks at redesigning 3DP machine, using piezoelectric demand-mode technology head in order to improve accuracy, surface finishing and color quality of constructed models. The layers created with aforesaid system are between 25 to 150 μm (steps of 25 μm).     

The endogenous cannabinoid system controls extinction of aversive memories

Acquisition and storage of aversive memories is one of the basic principles of central nervous systems throughout the animal kingdom. In the absence of reinforcement, the resulting behavioural response will gradually diminish to be finally extinct. Despite the importance of extinction, its cellular mechanisms are largely unknown. The cannabinoid receptor 1 (CB1) and endocannabinoids are present in memory-related brain areas and modulate memory. Here we show that the endogenous cannabinoid system has a central function in extinction of aversive memories. CB1-deficient mice showed strongly impaired short-term and long-term extinction in auditory fear-conditioning tests, with unaffected memory acquisition and consolidation. Treatment of wild-type mice with the CB1 antagonist SR141716A mimicked the phenotype of CB1-deficient mice, revealing that CB1 is required at the moment of memory extinction. Consistently, tone presentation during extinction trials resulted in elevated levels of endocannabinoids in the basolateral amygdala complex, a region known to control extinction of aversive memories. In the basolateral amygdala, endocannabinoids and CB1 were crucially involved in long-term depression of GABA (gamma-aminobutyric acid)-mediated inhibitory currents. We propose that endocannabinoids facilitate extinction of aversive memories through their selective inhibitory effects on local inhibitory networks in the amygdala.