"Forensic Science-Technical specifications for diatom inspection-Microwave digestion-vacuum filtration-microscopy"(GA/T 1662-2019)is currently the standard method used in forensic diatom testing.During the use of this method,the author found problems such as incomplete tissue digestion,excessive diatom fragments,too long suction filtration time,uneven baking of the filter membrane electric heating plate,and insufficient sample dryness.After continuous experimentation in the laboratory,some parameters of the inspection process were adjusted and the better expected results were achieved.The improved method only adds two basic equipment:a constant temperature water bath and a vacuum drying oven,making each experiment easy to realize.

Purpose To investigate the difference of resting-state functional connectivity density(FCD)between chronic primary insomnia patients and healthy controls via resting state functional magnetic resonance imaging(rs-fMRI).Materials and Methods All rs-fMRI data of 35 patients with chronic primary insomnia from Xidian Group Hospital and Xi'an Encephalopathy Hospital of Traditional Chinese Medicine,and 35 healthy controls were prospectively collected from August 2020 to December 2021.The voxel-wise FCD approach was applied to explore the differences of whole-brain functional networks between chronic primary insomnia patients and healthy controls.The relationships between FCD value and Pittsburgh sleep quality index,self-rating scale of sleep,insomnia severity index,self-rating anxiety scale and self-rating depression scale in primary insomnia patients were investigated,respectively.Results Compared with healthy controls,the decreased FCD values were showed in the right insula,bilateral anterior cingulate gyrus,left orbitofrontal middle gyrus,left dorsolateral superior frontal gyrus,right medial superior frontal gyrus and bilateral thalamus(t<-5.271,Padjust<0.05),while the increased FCD values showed in the right superior temporal gyrus,bilateral middle temporal gyrus,bilateral precuneus and left posterior cingulate gyrus(t>4.379,Padjust<0.05)in the chronic primary insomnia patients group.The FCD values of bilateral thalamus(r=-0.620,P<0.001;r=-0.562,P<0.005)and right insula(r=-0.651,P<0.001)were negatively correlated with insomnia severity index in the chronic primary insomnia patients group,respectively.Conclusion The extensive functional connectivity abnormalities are observed in primary insomnia patients via FCD analysis.These findings explain the neural mechanisms of underlying emotional regulation and cognitive impairment in chronic insomnia from the perspective of functional integration and functional separation.

Objective To summarize the characteristics of multi-slice computed tomography (MSCT) of portal vein diseases and investigate the CT diagnosis of its primary and secondary diseases.Methods The imaging data of 62 patients from Xi'an Xidian Group Hospital,28 patients from Nuclear Industry 215 Hospital of Shanxi Province and 16 patients from Xi'an Gaoxin Hospital with portal vein diseases from January 2012 to March 2015 were retrospectively analyzed.The CT findings,primary and secondary diseases of portal vein lesions were recorded through plain scan and enhanced scan of MSCT.Results Changes in the width of portal vein:among 106 patients,dilation of main portal vein was detected in 45 cases,stenosis of stem or branches of portal vein in 39 cases,portal vein obstruction in 49 cases (21 patients accompanied with enlargement in stem of portal vein and 6 patients with normal width).The diameters of dilated portal vein were 1.4-2.2 cm with a mean diameter of 1.8 cm.The diameters of portal vein with stenosis and occlusion caused by carcinomas were 1.8-4.0 cm with a mean diameter of 2.3cm.Portal vein fistula and pneumatosis:hepatic artery-portal vein fistulas were detected in 12 patients,posterior right branches of portal vein-inferior vena cava fistulas in 2 patients,inferior vena cavaportal vein fistulas and portal-hepatic vein fistulas in 2 patients,pneumatosis in 2 patients.Lesions of portal vein occlusions:occlusions located at main portal veins were detected in 4 cases,left and right branches in 34 cases,both main portal veins and left or right branches in 11 cases.Malignant stenosis and occlusion were detected in 29 and 42 cases,benign stenosis and occlusion were detected in 10 and 7 cases,respectively.Protopathies of portal vein dilation:there were 43 patients with liver cirrhosis and 2 patients with inferior vena cava-portal vein-hepatic vein fistula of Budd-Chiari syndrome.Protopathies of benign stenosis and occlusion:portal vein thrombosis in liver cirrhosis,giant cavernous haemangioma,polycystic disease of liver,pylephlebitis caused by liver abscess,portal vein thrombosis caused by polycythemia vera.Protopathies of hepatic artery portal vein fistula and portal veininferior vena cava fistula:liver cancer and liver cirrhosis,protopathy of inferior vena cava-portal vein fistula and portal vein-hepatic vein fistula were Budd-Chiari syndrome.Protopathies of pneumatosis:intestinal infarction after superior mesenteric artery embolus and acute gastric dilatation.Portacaval collateral circulation occurred in 58 patients (partial patients complicated with multi-point varices and shunts),ascites in 44 patients,portal vein cavernous transformation in 12 patients,ischemia and edema of intestinal wall in 5 patients,intrahepatic cholangiectasis in 19 patients including 17 cases of biliary obstruction caused by malignant tumors and 2 cases of portal vein cavernous transformation complicated with intrahepatic cholangiectasis (portal hypertensive biliopathy).Conclusions The MSCT for portal vein diseases is presented as portal vein stenosis,occlusion or dilation,pneumatosis.Secondary lesions are portacaval collateral circulation,portal vein cavernous transformation,intestinal ischemia and portal hypertensive biliopathy,and primary lesions are mainly liver cirrhosis and malignant tumors.MSCT can show clearly the portal vein lesions and diagnose accurately its primary and secondary lesions.