The Application Of Digital Virtual Slicing Technique In Survey Of Diatoms In Waters Of Wuhan And Research On Best Break-up Time Of Digestion Can

【Backgroundand Purpose】To expose the crimes and maintain social fairness and justice is an important partof building a harmonious society."Lifetime drowning" or "After the death ofpostmortem" represents the direction of the two distinct civil and criminalinvestigation. The correct direction of the investigation, determine the nature of thecase, the investigation of cases is extremely important to combat crime and maintain afair and justified the starting point. Diatom test have great value to determine thenature of such cases and enable the investigation, trial benefit fro m the wide range ofcases which conform the demand of overall national interest and the judiciary.In the recent forensic practice, the biological and chemical indicators of theTribunal for the diagnosis of drowning has not yet been confirmed scientifically andreasonably, diatoms test remains the "gold standard" for the diagnosis of drowning.But when diatoms’ quality is small, because of problem of the observer’s experience,missed or false-negative which leads to the error to determine the nature of the casewill often come out. A new and objective method for identification of plankton will nodoubt contribute to the judicial practice and social harmony and stability.Digital virtual the sliced technique (OLYMPUS-DotSlide) is a highly integratedset of software and hardware systems with combination of speed, automaticity,easy-to-use and other characteristics and can scan the entire slice with auto focus inneed magnification, then automatically seamless puzzle, which has broad applicationprospects. The application of Digital virtual slice technique’s research results on the pathomorphology brings new opportunities for the forensic identification of drowning.This study is based on previous work, draw on relevant research results, intend to usetechnique of modern forensic pathology to apply theory and technique of the digitalvirtual slice technique independently and groundbreaking for drowning identificationand create a set of methods of detecting and analyzing plankton for the drowningidentification, infer drowned location. This study has a wide range of applications, theresults of which are expected to establish a water diatoms form database of Wuhanand the rest of the region of the country, which has important academic and socialvalue in practice.Wuhan is the capital city of Hubei province, one of the important economic andtourism city and Railway hub. The city has a population of over ten million and themobility is large. Yangtze river and Hanjiang river cross the city and small or largelakes is everywhere, so it is a high-risk areas of the case of drowning. Establishingdiatom shape database of the waters of Wuhan City can provide the detection platformfor the drowning cases on diatom contradistinction, which has a great importance forthe diagnosis of drowning and infer place of death.There are a lot of diatom test methods, for example, chemical methods, physicalmethods, chlorophyll a methods and DNA methods, but the most of them havedrawbacks of complicated operate, inefficient, low detec tion rate, high equipmentrequirements, polluted working environment and the possibility that it may damage toforensics’ physical health and so on. However, Tank nitration of the broken machinehas overcome the deficiencies of the above test methods, which has characteristic ofconvenient, fast, high detection rate, is an ideal method of test diatoms.Broken machine tank nitration is mainly affected by Crusher temperature,crusher time, the proportion of the samples and nitric acid and so on, and arrangingthese parameters reasonably can play the advantages of Digestion can test of thediatoms on the greatest degree and meet digital virtual slice technique test diatomwhich has features of high positive detection rate, the high accuracy of counting, andhigh efficiency of the drowning, therefore, based on the previous studies. There is a great significance on the objective test conditions of diatom test that use the methodof the Crusher cans nitration, especially in the exploration of the best break-up time.【Material and methods】(1) During March to April of2012, in Wuhan City’s major rivers, lakes, parks, Iselect32points for water harvesting, water sampling, use the method of the Crushercans nitration to test water samples of diatom, and then use the digital virtual slicetechnique to collect Image, identify diatom species and counting, and apply theMicrosoft Excel software on the diatom species, count, constitute for statisticalanalysis.(2) The experiment consists of the group of animal experiments, the group ofhuman material for examination, respectively use diatomaceous earth with SD ratsand human examination material for the experiment, under different temperatureconditions, use Digestion can nitrification to do diatom test, then use digital virtualslicing technique to collect image, note the number of diatoms in smear of slice, usethe SPSS10.0for windows software for statistical analysis.【Results】(1) According to the identification of diatoms in water samples ofcentral parts of Wuhan, there are14submits of diatom, the proportion of diatom anddiatom species contained in all waters is the different.(2) As the break-up time gradually increases, quality of diatom in the group ofanimal experiments, the group of medical materials increased first then decrease, thetwo sets ofexperiments diatom’s extent of the damage and the machine-breaking timewas positively correlated.【Conclusion】(1) This study demonstrated the feasibility of using digital virtual slicetechnique to identify diatoms and summarizes the characteristics of diatomdistribution in the waters of Wuhan City, a comprehensive analysis and evaluation onit has the significance on inferring the falling location of death in the criminalinvestigation and establish the database of diatom shape and the relative composition in Wuhan central urban waters.(2) At a temperature of100℃, under the condition of nitrate: samples=1:1, thebest break-up time by using the Crusher cans nitration to test diatoms is the startingtime when samples are completely nitrified, the broken machine time in animal(SDrats) experiments is90min and the actual prosecution case120min. Under theconditions of the best break-up time, there will be higher detection rate using theDigestion can to test diatoms, associating with the digital virtual slice technique caneffectively improve the efficiency of diagnosis of drowning.