BACKGROUND:Membrane guided bone regeneration technology has become an important method in repairing bone defects. With the deepening of the research, related concept and the mechanism of membrane guided bone regeneration have been gradual y confirmed, but there are stil some unresolved issues.
OBJECTIVE: To review the classification of membrane tubes, performance, disadvantages and advantages in membrane guided bone regeneration, as wel as some unresolved issues in application and research.
METHODS:The first author searched PubMed and CNKI databases to retrieve articles about the discovery of membrane guided bone regeneration and the concepts, classification of membrane tubes, performance, disadvantages and advantages during bone defect treatment, which were published from 1963 to 2013. The key words were“guided bone regeneration, guided tissue regeneration, bone defect treatment”in English and Chinese, respectively.
RESULTS AND CONCLUSION:Membrane guided bone regeneration technique is a most promising treatment for bone defects, but for the treatment of long tubular bone defects, it is stil in the experimental stage. Currently, there is no membrane tube for long-segment bone defects. According to the material sources, the membrane tubes can be divided into:non-biological material, such as polytetrafluoroethylene, polylactic acid, silica gel, titanium film;biological materials, such as col agen membrane, chitin membrane, polyhydroxybutyrate. The membrane tubes can also be classified into nondegradable materials and biodegradable materials. Biodegradable materials have good histocompatibility and no cytotoxicity, which can degrade in a certain period after implantation;part of the membrane can also al ow free exchange of tissue fluid and nutritional substances. But there are stil some shortcomings that the degradation time is difficult to control and the volume is difficultly maintained under the membrane tube. New bone formation in non-biodegradable materials is complete. In the process of osteogenesis, the membrane tube cannot be absorbed and has to be removed secondarily, though it has good histocompatibility and better therapeutic outcomes. In the future, we should further improve membrane performance, so that the membrane tube can play a dual role, fixation and guided bone regeneration;a series of animal studies should be conducted to study the effect of stress on the membrane tube and osseointegration within the membrane tube, to master the law of osseointegration of membrane tubes, thereby providing evidence for repair of long tubular bone defects.

Thyroid carcinoma is the most frequent endocrine cancer.Recently, it has been discovered that telomerase reverse transcriptase promoter mutation can prevent cell tolemeres from shortening, leading to cell immortalization and plays an important role in the tumor genesis, invasiveness and metastasis of the thyroid carcinoma.Testing of telomerase reverse transcriptase promoter mutation is of great value in diagnosis, which also can be used as a prognostic maker of thyroid carcinoma.

OBJECTIVE:To compare the clinical efficacy and safety of rivaroxaban and low molecular weight heparin calcium (LMWHA)in the prevention of deep venous thrombosis(DVT)after total hip arthroplasty(THA). METHODS:A total of 100 THA patients selected from orthopedics department of our hospital as research objects were divided into control group and observa-tion group according to random number table,with 50 cases in each group. Control group was treated with LMWHA injection 0.4 mL subcutaneously,qd;observation group was given Rivaroxaban tablet 10 mg orally,qd. Both groups received treatment on the first day after surgery,for consecutive 14 d. Coagulation indexes(PT,APTT,Fib,TT,D-D),VAS score,the incidence of DVT and PE were observed in 2 groups. The postoperative bleeding volume and ADR as hematoma and gastrointestinal bleeding were compared between 2 groups. RESULTS:Before treatment,there was no statistical significance in coagulation indexes or VAS scores between 2 groups(P>0.05). After treatment,PT,APTT,TT and D-D levels,VAS scores of 2 groups were decreased sig-nificantly,while Fib levels were increased significantly;VAS score of observation group was significantly lower than that of con-trol group,with statistical significance(P<0.05). There was no statistical significance in coagulation indexes between 2 groups (P>0.05). The incidence of DVT and PE in observation group were 8.00% and 7.50% ,which were significantly lower than 12.00% and 4.00% of control group,with no statistical significance(P>0.05). The postoperative bleeding volume of observation group was(298.31±52.18)mL,which was significantly lower than(327.40±54.20)mL of control group,with statistical signifi-cance(P<0.05). There was no statistical significance in the incidence of hematoma or gastrointestinal bleeding between 2 groups (P>0.05). CONCLUSIONS:Rivaroxaban and LMWHA can significantly improve coagulation state,prevent the generation of DVT after THA. While rivaroxaban is better in shortening pain time without increasing the risk of ADR.

Objective To investigate the related factors of postoperative hypocalcemia after thyroid carc-er surgery.Methods 346 cases of thyroid carcer patients undergoing surgery from Jan .2013 to Dec.2013 in the First Affiliated Hospital of Zhengzhou University were retrospectively analyzed .Results 129 cases developed hepocalcemia after thyroid surgery .Among the related factors that may cause postoperative hypocalcemia , the scope of surgery , parathyroid injury and secondary surgery might play important roles .Conclusions The inci-dence of postoperative hypocalcaemia is high after total thyroidectomy .Patients with reoperation and lymph node dissection have an increased rate of postoperative hypocalcaemia .In order to reduce hypocalcaemia incidence ,sur-gons need to protect parathyroid blood supply in thyroid surgery and give calcium after surgery .

Objective To evaluate the curative effects of carbon nanoparticles on central lymphnode dis -section in papillary thyroid carcinoma ( PTC) .Methods 72 PTC patients were randomly divided into two groups:carbon nanoparticle group(n=32)and the control group(n=32).Patients in the carbon nanoparticle group were injected with carbon nanoparticles during surgery .Patients in the control group had conventional surgery .The number of lymph nodes being dissected ,lymph node metastasis , and the rate of hypoparathyroidism were compared between the two groups .Results The number of lymph nodes dissected in nanoparticle group ( n =312 ) was much bigger than that in the control group (n=189)(P<0.01;t=8.476).The incidence of hypoparathyroidism in nanoparticle group(n=1)was much lower than that in the control group (n=8)(P<0.05;χ2 =4.571).The metastasis of lymph nodes has no significant difference between the two groups (P>0.01;χ2 =1.048).Conclu-sions The lymphatic tracer technique may improve the number of lymph nodes dissected in central region of PTC and reduce parathyroid gland damage .

OBJECTIVE:To explore the clinical effect and safety of Zoledronic acid injection combined with percutaneous ver-tebroplasty for osteoporotic vertebral compression fracture(OVCF). METHODS:A total of 130 OVCF patients selected from our hospital during Jan. 2014-Dec. 2015 were divided into observation group and control group according to random number table,with 65 cases in each group. Control group was given bone cement by percutaneous vertebroplasty. Observation group was additionally given Zoledronic acid injection 5 mg,ivgtt,once a year(dripping time ≥15 min),on the basis of control group. Both groups were given calcium and vitamin D orally after surgery. VAS scores,Oswestry disability index(ODI)and ADL scores were ob-served in 2 groups 1 week and 6 months after treatment. Bone density of lumbar vertebra L1-L4 and femoral neck were detected in 2 groups after one year of treatment. RESULTS:Before treatment,there was no statistical significance in VAS scores,ODI or ADL scores,bone density of lumbar vertebra LI-L4 and femoral neck between 2 groups(P>0.05). VAS scores and ODI of 2 groups were decreased significantly,while ADL scores were increased significantly 1 week and 6 months after treatment;obser-vation group were significantly better than control group,with statistical significance(P<0.05). One year after treatment,bone density of lumbar vertebra L1-L4 and femoral neck in observation group were significantly higher than control group,with statis-tical significance(P<0.05). There was no statistical significance in the incidence of ADR between 2 groups as fever,dizziness, bone and joint pain,muscle soft tissue pain and new fracture(P>0.05). CONCLUSIONS:Zoledronic acid combined with per-cutaneous vertebroplasty in the treatment of OVCF can significantly relieve pain,improve dysfunction and enhance bone density with good safety.

Atrial fibrillation (AF) is a common arrhythmia, which can lead to thrombosis and increase the risk of a stroke or even death. In order to meet the need for a low false-negative rate (FNR) of the screening test in clinical application, a convolutional neural network with a low false-negative rate (LFNR-CNN) was proposed. Regularization coefficients were added to the cross-entropy loss function which could make the cost of positive and negative samples different, and the penalty for false negatives could be increased during network training. The inter-patient clinical database of 21 077 patients (CD-21077) collected from the large general hospital was used to verify the effectiveness of the proposed method. For the convolutional neural network (CNN) with the same structure, the improved loss function could reduce the FNR from 2.22% to 0.97% compared with the traditional cross-entropy loss function. The selected regularization coefficient could increase the sensitivity (SE) from 97.78% to 98.35%, and the accuracy (ACC) was 96.62%, which was an increase from 96.49%. The proposed algorithm can reduce the FNR without losing ACC, and reduce the possibility of missed diagnosis to avoid missing the best treatment period. Meanwhile, it provides a universal loss function for the clinical auxiliary diagnosis of other diseases.
Algorithms ; Atrial Fibrillation/diagnosis* ; Electrocardiography ; Humans ; Neural Networks, Computer ; Stroke