BACKGROUND: The design of the microstructure of human bone is in fact to construct a model, which could characterize the connecting-porosity cell frame structure. As the porosity structure is represented as irregular curve, and this irregularity has close relationship with the bone function, does the fractal theory effectively find the irregularity containing in the irregular structure?OBJ ECTIVE: To analyze the microstructure of human bone by applying the fractal property, and construct the 3D model that has structural similarity to the natural bone. With the help of Rapid Prototyping technology, a new bionic technique instead of traditional modeling method is presented to model artificial human bone.DESIGN: Computer aided bionic design.SETTING: Biomaterials and Engineering Center of Wuhan University ofTechnoiogy.MATERIALS: The experiment was carried out in the Biomaterials and Engineering Center of Wuhan University of Technology from January to June 2005. The material is the original gray chart of hip joint of one healthy middle-aged male.METHODS: The contour of the human bone microstructure was obtained by exaltation and extraction of the grey chart.B-spline technique was used for vectorization. ①The fractal theory was adopted to compute the fractal dimension of typical aperture structure and the result was represented by dimensions (D=2s, s is the slope of fitting line) to find the inherent relation among apertures. ② Monte Carlo method was used to generate the two-dimensional model of microstructure of bone with the appropriate porosity. The 3D model was manufactured by rapid prototyping technology.MAIN OUTCOME MEASURES: ①Fractal dimension of porous structure of human bone; ② Results of 2D and 3D model of the microstructure of human bone.RESULTS: ①The fractal dimensions of some representative apertures were between 1.14and 1.28. The fractal dimensions of these micro-apertures are rather close, which testified the self-similarity in the edge contour of the microstructure of human bone. ②3D model was generated by cumulating the plane model layer by layer with the rapid prototyping technology. If the high porosity of plane model was ensured, the porosity and connectivity of 3D model could meet the high requirement. Through the computer simulating, the porosity of the model was greater than 40%, which meets the design requirement.CONCLUSION: Fractal theory is applied in the construction of 2D model of human bone based on the requirements in bionic design of the microstructure model of human bone. The fractal characteristics of the grey chart of human bone and the edge contourof its typical micropore are analyzed. The software suitable for 2D tissue engineered bionic microstructure of human bone is developed with VC++, meanwhile, 3D cell scaffold model is constructed by cumulating the planer model, which meets the human bone functions.

BACKGROUND:Domestic scholars use the potentiodynamic polarization technique to determine the corrosion potential of the dental aloys, which is used to evaluate the corrosion performance of the lownoble metal. They have discovered that the main reason affecting corrosion resistance is the content of noble metal. OBJECTIVE:To evaluate the corrosion resistance of Ti, Au aloy, Co-Cr aloy, Ti aloy, and Ni-Cr aloy. METHODS: Five aloys were immersed in synthetic saliva solution. The corrosion potential and corrosion current density of the aloys were determined with potentiadynamic polarization technique. RESULTS AND CONCLUSION:The galvanic series of five kinds of aloys were ranged as folows: Au aloy > pure Ti > Ti aloy > Co-Cr aloy > Ni-Cr aloy. Au aloy and pure Ti had more positive potential that were not easy to produce corrosion; Ti aloy and Co-Cr aloy could form stable oxidation film with a strong ability of anti-pitting and crevice corrosion; Ni-Cr aloy potential was more negative and easy to be dissolved. The corrosion current density of five kinds of aloys was ranged as folows: Au aloy < pure Ti < Ti aloy < Co-Cr aloy < Ni-Cr aloy. Au aloy and pure Ti had lowest current density which was 10-8, indicating that the corrosion rate of Au aloy and pure Ti was lower; in contrast, Ni-Cr aloy possessed the maximum corrosion rate. These findings indicate that Au aloy and pure Ti exhibit a very high corrosion resistance. The corrosion rate of Ni-Cr aloy is the highest; therefore, Ni-Cr aloy is the least acceptable material for implant suprastucture.

Stroke is one of the major diseases that threaten human health, early diagnosis and treatment are very important for stroke. Carotid intima-media thickness (CIMT) is measured noninvasively to diagnosis stroke, and it is a independent predictor for stroke because its thickening can timely predict the incidence and development of stroke. As an important predictor of cardiovascular disease, more and more attention is played on CIMT. In this review, we will make a summary on the important role of CIMT in stroke and the mechanisms of carotid intima-media thickening in stroke as well as the potential use of traditional Chinese medicine in treating carotid intima-media thickening.
Animals ; Carotid Arteries ; drug effects ; physiopathology ; Carotid Intima-Media Thickness ; Drugs, Chinese Herbal ; therapeutic use ; Humans ; Stroke ; diagnosis ; drug therapy ; physiopathology

Objective: To compare the pharmacokinetics and relative bioavailability of rapid oral disintegrating tablet of dimenhydrinate (RODTD) and those of market available tablet of dimenhydrinate (DMH). Methods: Eight healthy volunteers were evenly randomized into 2 groups, one group received RODTD (25 mg) and the other received available market tablet of dimenhydrinate (25 mg). The blood levels of DMH were determined by high performance liquid chromatography (HPLC) before and after drug administration in 2 groups. Chromatography conditions were: Nova-Pak C18 as chromatographic column, methanol triethylamine buffer (1 : 1),flow rate: 1.0 ml/min, detection wavelength: 225 nm, and room temperature. The pharmacokinetics and relative bioavailability of RODTD and market available tablets were investigated. Results: The standard curve of DMH in the blank plasma was linear within the range of 5-500 ng/ml, with the regression equation being C=0.004 4 A+4.745 and R2=0.996. The limit of detection was 2 ng/ml; the average recovery rate was (90.55±4.69)% and the RSD was 0.041%. The intra-day derivations of 3 different concentrations (low, middle, and high) of plasma were 9.27%, 4.93%, and 2.95%, respectively (n=5), and the inter-day derivations were 9.97%, 3.81%, and 3.06%, respectively (n=5). Blood samples (3 ml) were subjected to HPLC assay and significant difference was found between the 2 forms of DMH. The pharmacokinetic parameters of RODTD were: AUC=(602.04±113.82) ng • h • ml-1, Cmax=(95.86±21.28) ng • h • ml-1, and TPeak=(1.8±0.32) h; the pharmacokinetic parameters of market available tablets were: AUC=(342.73±84.96) ng • h • ml-1 Cmax=(46.34± 10.32) ng • ml-1, and TPeak=(2.65±0.24) h. Statistical analysis showed there was significant difference in the relative bioavailability of 2 forms of DMH(P<0.01). The relative bioavailability of RODTD to market tablet was 175.66%. Conclusion: The developed RODTD can obviously increase the relative bioavailability of DMH.

Acupuncture Points ; Acupuncture Therapy ; instrumentation ; Catgut ; Female ; Humans ; Infertility, Female ; blood ; therapy ; Moxibustion ; Treatment Outcome

Cardiovascular Diseases ; drug therapy ; prevention & control ; Humans ; Hypolipidemic Agents ; administration & dosage ; therapeutic use ; Risk Reduction Behavior

Adult ; Anemia, Aplastic ; complications ; surgery ; Female ; Hematopoietic Stem Cell Transplantation ; Hemoglobinuria, Paroxysmal ; complications ; surgery ; Humans

Animals ; Antibodies, Helminth ; blood ; cerebrospinal fluid ; Child, Preschool ; Eosinophilia ; cerebrospinal fluid ; diagnosis ; etiology ; Female ; Humans ; Meningitis ; cerebrospinal fluid ; diagnosis ; etiology ; Neurocysticercosis ; complications ; drug therapy ; parasitology ; Taenia ; immunology

Coronary Disease ; drug therapy ; Humans ; Hypolipidemic Agents ; administration & dosage ; therapeutic use

Objective To observe the effect of multiple monitoring of total intravenous anes-thesia on postoperative cognitive function in elderly patients.Methods Elective 100 patients undergo-ing general anesthesia for abdominal operation,56 males,44 females,aged 65-80 years,ASA physi-cal status Ⅱ or Ⅲ.All patients were divided into multiple monitoring group (group M)and routine monitoring group (group R)by random digital table method,n =50 each.In group M,the anesthesi-ologists modulated anesthetic drugs to make NTI of 37-56 and rSO 2 higher than 50% or not lower than the baseline value by 20%,while in group R the infusion rate of propofol,remifentanil and cisa-tracurium was adjusted by anesthesiologists according to anesthesiologist’s experiences by the pa-tients’monitoring index.Cognitive function of patients in the two groups were evaluated using MMSE 1 d before surgery and 1 d,3 d,7 d,1 month and 3 months after surgery.The occurrence of cognitive dysfunction 7 d,1 month and 3 months after surgery,the postoperative recovery and the dosage of propofol,remifentanil and cisatracurium were recorded.Blood was randomly selected from each group to determine the serum content of S100βand Aβ1-42 by ELISA method at the time point of before surgery (T0 ),one hour after starting surgery (T1 ),the end of surgery (T2 )and postopera-tive 24 hours (T3 ).Results The incidence of postoperative cognitive decline in group M on 1 d (8%vs.22%),3 d (2% vs.1 6%)after surgery were significantly lower than that in group R (P <0.05). Postoperative cognitive dysfunction between the two groups 7 d and 1 month,3 months after surgery has no statistical significance.The dose of propofol [(3.3 ± 0.8)mg · kg-1 · h-1 vs.(3.7 ± 0.7 ) mg·kg-1 ·h-1 ,P < 0.05 ] and cisatracurium [(104 ± 47 )μg · kg-1 · h-1 vs.(124 ± 68 )μg·kg-1 ·h-1 ,P <0.05]in group M was less than that in group R.The time of eye-opening [(10 ±3)min vs.(1 6±6)min,P <0.01],extubation [(13±3)min vs.(22±7)min,P <0.01]and lo-cation [(1 7±4)min vs.(27 ±9)min,P <0.01 ]was shorter in group M.Compared with T0 ,the serum level of S100βprotein was significantly increased in group M at T1 ,T2 and group R at T1-T3 (P <0.05);The level of serum S100βprotein in group M was significantly lower than that in group R (P <0.05).Compared with T0 ,Aβ1-42 protein level was significantly reduced in two groups at T1 and T2 (P <0.05),but there was no significant difference between the two groups.Conclusion Total intravenous anesthesia with multiple monitoring can reduce neural injury and reduce the incidence of early postoperative cognitive decline in elderly patients with abdominal surgery,but has no significant effect on the incidence of POCD.