The phenotypes of human fetal thymocytes has been analysed with fflowcytometry.The findings suggest that the composition of thymocyte subsets shows no obvious changes from the 17th week of gestation to birth.In the pieriod of human fetus,features of thymocyte phenotypes are showed:1.Expression density of CD3/TCR?? shows a continuous distribution from low to high.According to the density of D3/TCR??,tyhmocytes can be divided into three subsets,that is,L—CD3/TCR??(low—density),M—CD3/TCR?? medium—density)and H—CD3/TCR??(high— density).The proportion of three subsets is different in different fetuses.2.Single positive thymocytes express CD1 antigens.H—CD3/TCR?? thymocytes also express CD1 antigens.But,Part of those thymocytes express low—density of CD1 antigens,other part of the hymocytes express high—density of CD1 antigens.3.HLA class Ⅰ antigen density varies with thymocytes.Most thymocytes express low density of HLA class Ⅰ antitgens,minor thymocytes express high density of HLA class Ⅰantigens.HLA class Ⅰ antigen density correlates with maturity of thymocytes.4.Thymocytes can be divided into two subsets:Thy-L and Thy-H on the basis of thymocyte special density by means of density gradient centrifugation.Thy-L subset includes more mature and early thymocytes than Thy-H subset,while thy-H subset includes much more common thymocytes than Thy-L subset.

The postoperative neurological complications is associated with intraoperative cerebral emboli, which results from extracorporeal circulation and operation. It can effectively reduce the incidence of neurological complications with ultrasonic radiation. In fluids, a particle will change it's motion trail when it is acted by the radiation force generated by the ultrasound. This article mainly discuss how to shielding emboli with ultrasound. The equipment can transmit phased ultrasonic signals, which is designed on a FPGA development board. The board can generate a square wave, which is converted into a sine wave through a power amplifier. In addition, the control software has been developed on Qt development environment. The result indicates it's feasible to shielding emboli with ultrasonic radiation force. This article builds a strong foundation for the future research.
Humans ; Intracranial Embolism ; diagnostic imaging ; prevention & control ; Intraoperative Complications ; prevention & control ; Postoperative Complications ; prevention & control ; Ultrasonics ; instrumentation ; Ultrasonography

BACKGROUND:Three-dimensional (3D) nanofiber scaffolds are aimed to mimic the physical and chemical signals of stem celsin vivo. 3D nanofiber scaffolds, which are capable to maintain the activity of stem cels, are promising in tissue regeneration and stem celltherapy. OBJECTIVE:To review the synthesis methods for 3D nanofiber scaffolds, and the interactions of stem cels and 3D scaffolds as wel as the current progress of 3D nanofiber scaffolds in tissue engineering. METHODS:Web of Science was searched with key words of “tissue engineering, nanofiber scaffold, stem cellfate” in English for articles relevant to stem celltissue engineering and 3D nanofiber scaffolds. RESULTS AND CONCLUSION:3D nanofiber scaffolds can mimic the physical architecture ofin vivo microenvironment due to its nano-scale topology. Chemical modification of scaffolds endows chemical cues to stem cels. Therefore, 3D nanofiber scaffold can be a promising delivery vehicle of stem cels in tissue engineering. Nanofiber scaffolds can be synthesized through self-assembly, sol-gel phase separation, and electric spinning. 3D nanofiber scaffolds have been shown to improve thein vitro proliferation of hematopoietic stem cels, embryonic stem cels, mesenchymal stem cels, and neural stem cels. 3D nanofiber scaffolds with specific topology/chemical properties can induce the differentiation of stem cels into bone, cartilage, nerve, or muscle. 3D nanofiber scaffold which provides a satisfactory microenvironment for stem cellenhance the performance of stem celltherapy.

Objective to compare the calculated effective radiation dose variations in cardiac interventional procedures of coronary angiography (CAG) and percutaneous transluminal coronary angioplasty (PCI) by using the different tissue weighting factors recommended by ICRP Publication 60 with that recommended by ICRP Publication 103. Methods Measurements of organ doses were carried out with an anthropomorphic phantom equipped with thermoluminecent dosimetry. The effective radiation doses were separately calculated using the tissue weighting factors provided by ICRP 60 and provided by ICRP 103, and the results obtained from ICRP 60 were compared with that obtained from ICRP 103. Conversion factors of effective, radiation dose to dose area product (DAP) were also calculated according to different publication.Results The variations in the effective dose were 6.88% for CAG and 8.46% for PCI. The effective dose variations in CAG and PCI were. 7.25% and 8.76% for female and were 6.51% and 8.17% for male,respectively. The effective conversion factors of DAP were. 0.10 ～ 0.11 and 0.13 ～ 0.14 for CAG and PCI,respectively, according to ICRP 60 and 103. Conclusion The variation of conversion factors of effective dose indicates that in making estimation of effective radiation dose. by using the widely accepted conversion factors, the adjustment of organ weighting factors recommended by ICRP 103 should be considered.

Objective:To explore the pharmacological basis of clinical application of Dachaihu Decoction. Methods: The relevant relation between cilnical features of Dachaihu Decoction and its pharmacological actions are analysed. Results: The various clinical curative effects rest on its relevant pharmacological actions.Conclusion: The good clinical curative effects will be achieved according to Dachaihu Decoction.

Objective To estimate the effective dose during 64-slice CT examination on head,chest and abdomen and determine the conversion coefficient of effective dose and dose length product(DLP).Methods The plain CT scan wag performed in 48 cases on head,50 cases on chest and 45 cages on abdomen using GE Lightspeed 64-slice spiral CT.1The Kv,Ma,scan time,CTDIvol,and DLP were recorded in each examination.Effective dose on patients Was estimated using the SR 250 software.Results The effective dose on head,chest and abdomen was(3.1±0.1),(6.9±0.1)and(8.0±0.1)mSv,and the conversion Coeffieient was 0.0025,0.0191 and 0.0166 mSv·mGy-1·cm-1 respectively.Conclusion CTDIvol、DLP and effective dose were recommended for patient dose control during CT examination.The conversion factor of effective dose and DLP were recommended for radiation risk evaluation during different X-ray examinations.

Objective To study the role of corn oil in the change of serum glucose, serum lipids and insulin in type 2 diabetes rats with insulin resistance, and attempt to find out its mechanism. Method High fat and sugar diet plus low-dose streptozotocin (STZ) was given to establish type 2 diabetes rat with insulin resistance model, the rats of which were randomly divided into normal group, model group, corn oil (0.8 mg/kg) group, rosiglitazone group. After Ig 6 weeks, fasting blood glucose (FBG), total cholesterol(TC), triglyceride(TG), low density lipoprotein(LDL), high density lipoprotein (HDL), fasting insulin (FINS), and insulin resistance index (HOMA-IR) were detected. Results Corn oil can elevate the level of HDL in diabetic rat, lower the levels of FBG, TC, TG, LDL, FINS and HOMA-IR. Conclusion Corn oil can improve insulin resistance, and decrease the serum glucose and lipid of type 2 diabetic rats.

Objective:To evaluate the effects of different ultrasonic retroprep tips on the root-end preparation in cadavers.Methods:34 anterior teeth in situ in maxillary and mandibular jaws in cadavers were chosen and the root-end of 3 mm of all teeth was exposed. Root canal was prepared and filled with gutta-purcha in all teeth,3 mm of the root end was cut off.The teeth were divided into 2 treat-ment groups(n=1 5),and 1 control group(n=4).The root-end preparation was made using ultrasonic diamond tip and stainless steel tip respectively to 3 mm depth.The teeth in control group were not treated.Microcracks,marginal integrity and gutta-percha clearance were observated under SEM.Results:Diamond ultrasonic tips provoked a smaller number of cracks(P=0.059)and destroy of margin-al integrity(P=0.269)than stainless steel tips.Less gutta-percha clearance was produced by stainless steel tip than that by diamond ultrasonic tip(P=0.006).Conclusion:Diamond ultrasonic tip is more suitable for root-end preparation.

Objective To assess the dose and image quality using a C-arm CT (DynaCT) system and compare the difference of image quality and radiation dose between DynaCT and Multi slice CT (MSCT). Methods Effective doses were measured from an anthropomorphic phantom with embedded thermoluminescence dosimeters (TLDs).For DynaCT,automatic exposure control (AEC) and high-quality (20 s rotation time) scans were used. For MSCT,scanning protocols for head were examined with conventional exposure conditions. Catphan phantom(Phantom Lab,USA) was used to evaluate the image quality for DynaCT and MSCT. Results For DynaCT,the effective doses from head scanning were 1.10 mSv; for MSCT,the effective doses from head scanning were 2.07 mSv,and there was a significant difference of organ dose between DynaCT and MSCT(P

Objective To investigate the influence of organ dose and effective dose on patients for different Z value during head,chest and abdomen CT scan. Methods With equispaced displacement on axis Z,organ dose and effective dose was estimated by using SR250 software with commonly used CT exposure parameters. Results Effective dose changed gradually for different Z value,some organ dose was sensitive to the Z location. Conclusion It is necessary to avoid X-ray sensitive organ in CT examination to minimize radiation risk.