Two kinds of Cu-containing intrauterine contraceptive device (Cu-IUD) has been evaluated through the study on the release of copper ion and corrosion of copper surface in artificially formulated fluid. The result showed that the copper ions were released profusely from the stainless steel stents Cu-IUD in the first week of soak (25-12 microg/d), and then it became slowly and steady. The release of the copper ions from the titanium nickel shape memory alloy stents Cu-IUD were always slowly and steady in two months (0.5-5 microg/d). It obviously shows that the corrosion on copper surface of stainless steel stents Cu-IUD were more serious than titanium nickel shape memory alloy stents Cu-IUD by using 200 times microscope testing before and after soaking in formulated fluid.
Copper ; chemistry ; Corrosion ; Intrauterine Devices ; Ions ; chemistry ; Stents

OBJECTIVETo study the Cupric ion release characteristics of different copper raw materials in intrauterine device in vitro by ICP. Reveal the relationship between purity and shape of Cu-IUD copper and copper ion release.

METHODSAccording to a certain proportion, the copper raw materials were 100 times diluted into the simulated uterine solution at 37 +/- 0.5 degrees C. Replaced medium at certain time points and collected soaking liquid. Using ICP analyzed the concentration of copper ion released.

RESULTSThe largest daily release of copper ions was in the first 7 days. There was no statistically significant difference between the copper ion release amount of 99.99% and 99.95% purity copper wire (P > 0.05). The release of copper ion of the copper wire was far greater than that of the copper pipe in early stage (P < 0.01). The release amount decreased and stabilized at 56 day.

CONCLUSIONRelease characteristics of copper ion could effectively analysis by ICP. And in the same area, the release amount of copper ions of copper wire was greater than that of copper pipe.

OBJECTIVE: To study the self-tapping performance test method of self-tapping bone screws based on the YY/T 1505 standard. METHODS: With reference to the method of YY/T 1505, various factors affecting the self-tapping force test was optimised, and the self-tapping force judgment method was improved. RESULTS: The experimental results showed that the self-tapping force obtained by the improved self-tapping force judgment method has good repeatability and high stability of the experimental data. At the same time, the test results of other influencing factors indicated that the manufacturer should fully consider the test material and the size of the pre-drilled hole. CONCLUSIONS An improved method for judging the self-tapping force is helpful for the repeatability and stability of the test data. This study has certain significance referring to the self-tapping performance test of self-tapping bone screws.
Biomechanical Phenomena ; Bone Screws

The clinical failure factors of Orthopedic implants which happened recent years have been summarized. The main failure factors are quality of orthopedic implants itself, iatrogenic and patient-derived. The ways to preventive measures have been suggested.
Orthopedic Procedures ; instrumentation ; Prostheses and Implants ; Prosthesis Failure

The finite element method was used for simulating the mechanical performance and fatigue safety of three different structures of Nitinol stent. According to the actual situation, after proposing reasonable assumptions and simplification, the geometry model and finite element model establishment, material mode selection and boundary condition setting are completed. The strain and fatigue life of different stent edges wide (omega) or strut angle (theta) are computed. The result can provide a valuable reference for the optimal design of stent.
Alloys ; Finite Element Analysis ; Prosthesis Design ; Stents

The FE model of proximal humeral locking plate was established and analyzed to provide academic support of the proximal humeral locking plate failure. The stress distributions of the locking plate were observed under the situations of the fracture area providing support and without support. In summary, this type of locking plate cannot afford the stress at 120 degrees abduction position under the situation of fracture area provides without support. In order to reduce the probability of locking plate failure, it is recommended that using other type of locking plate instead or avoiding 120 degree abduction of the patient.
Bone Plates ; Equipment Failure Analysis ; Finite Element Analysis ; Humans ; Humeral Fractures ; Materials Testing ; Prosthesis Failure ; Stress, Mechanical

Objective To explore the risk factors of cerebral schistosomiasis japonica. Methods A total of 37 confirmed cases,diagnosed during 1999-2004 in Anhui Province,were involved in the study as case group. Three controls for each case were selected from the general population either without schistosomiasis,with chronic schistosomiasis or with acute schistosomiasis. The relevant risk factors on the disease were analyzed. Results Four factors with labour intensity, physical, economical and nutritional conditions before illness between case group and normal control group, 7 factors including epilepsy history, hypersensitivity,intensity and times of infection between case group and acute schistosomiasis control group,10 factors including intensity of infection,times of infection and treatment between case group and chronic schistosomiasis control group, all showed statistical significance (p

The orthopedics implants failure management system has been put forward according to the present status. The function of the system and typical failure case reasoning route also have been described. Furthermore, the analysis process has been presented by illustrating a typical failure case analysis.
Medical Records Systems, Computerized ; Orthopedic Procedures ; instrumentation ; Prosthesis Design ; Prosthesis Failure ; Software Design

Objective:To observe the effects of herbal cake.partitioned moxibustion and bran-partition moxibustion in improving symptoms of ulcerative colitis(UC)and the TNF-α and its receptor of colon mucosa.Method:67 UC cases were randomly allocated into herbal cake-partition moxibustion group of 35 cases and bran-partitioned moxibustion group of 32 cases,to compare the improvement and detect the TNF-α and its receptor with inlmunohistochemical method in both groups.Result:Herbal cake.partitioned moxibustion iS prior to bran-partitioned moxibustion in improving of diarrhea,flatus,lassitude,tenesmus and lumbar soreness;The expression of TNF-α,TNF-αR1,and TNF-αR2 are significantly decreased after treatment in herbal cake-partitioned moxibustion group,while in bran-partitioned moxibustion group only TNF-αR1 expression is significant decreased after treatment.Conclusion:Moxibustion can well improve the syndromes of UC.Herbal cake.partitioned Moxibustion is prior to bran-partitioned moxibustion in the improvement of diarrhea and flatus;Herbal cake-partitioned moxibustion could down-regulate the expression of TNF-α,TNF-αR1.and TNF-αR2.while bran-partitioned moxibustion could only down-regulate the expression of TNF-αR1.

Biodegradable vascular stent, also known as the third generation stent, has recently been widely studied. Finite element models of three stents with the same structure and different specifications were developed. The mechanical behavior under crimping, expanding and fatigue testing were assessed by von Mises yield and Goodman convergence. The maximum stress during crimping, expanding and fatigue testing were all observed in the stent with the largest size. The results indicated that the largest stent had the highest risk of failure and also provided theoretical evidence for the worst case scenario in the fatigue testing.
Finite Element Analysis ; Polyesters ; Stents ; Stress, Mechanical