BACKGROUND:At present, researches about attention mainly concentrate on the relationship between attention and other psychological phenomena, but studies concerning different types of attention itself (sustained attention versus selective attention) are few. OBJECTIVE:To investigate the brain mechanisms of sustained and selective attentions which have different roles in the cognitive process. METHODS:Event-related potentials (ERPs) were measured when 18 col ege students’ participants (half male and half female) were performing selective and sustained attention tasks. The program was written in E-Prime and displayed on a computer, and the experimental task was adapted from Karl et al. reported experimental paradigm, including selective attention and sustained attention tasks. The time of fixation point given was 500 ms, and the time of three randomly abreast pictures given was 300 ms. Al the participants were asked to make rapid and accurate response as much as possible. RESULTS AND CONCLUSION:The ERPs elicited by the two attention tasks were different in the aspects of time process, wave crest and latency. The brain regions activated by the sustained attention were wider than those by selective attention. The ERPs elicited by the sustained attention mainly presents as positive waves, whereas those elicited by the selective attention were reflected as both positive and negative waves. The EPRs elicited by the sustained attention were N100 and N250, but in the metaphase, selective attention elicited the P180. These may indicate that event choice appears in the middle stage of the task. Besides, the reversion of EPRs elicited by the two attention tasks in the anterior and posterior scalp is likely to be a generality of al attentions.

Objective To explore curative effect of emergency treatment measures on ST segment elevation acute myocardial infarction.Methods A total of 142 cases of acute ST segment elevation myocardial infarction were received the thrombolytic therapy,percutaneous coronary intervention ( PCI) ,emergency coronary artery bypass graft-ing treatment.Results A total of 20 cases were received pre hospital thrombolysis,percutaneous coronary interven-tion ( PCI) therapy in 86 cases,32 cases of pre hospital thrombolysis combined with emergency PCI operation,4 cases of emergency coronary artery bypass graft surgery.The one year survival rates were 94.7%, 98.8%, 96.8%, 100.0%,respectively.Conclusion The prehospital diagnosis of acute myocardial infarction with ST segment eleva-tion is helpful for reducing recanalization time,and initialing the hospital treatment,so as to effectively simprove cardi-ac function and postoperative survival rate,which is worthy of clinical reference.

Objective To investigate the long-term effect of angioplasty of patients with symptomatic vertebrobasilar artery stent.Methods Thirty-three patients with symptomatic vertebral artery stenosis who underwent endovascular treatment stent.The clinical symptoms and stent restenosis were recorded.Results The clinical symptoms of 33 cases with angioplasty were improved significantly.The preoperative stenosis rate was (92.36 ±3.23)％ before operation and the average postoperative residual stenosis rate was (9.13 ±2.57)％ after operation.Clinical symptoms of 23 patients disappeared completely after operation,and 10 cases improved significantly.As to complications,1 case with severe basilar artery stenosis had a side numbness of extremities,1 case showed postoperative cerebral embolism,and return to normal after 3 days.When follow up periods lasted for 6-24 months,9 cases were with dizziness or other symptoms.Of which,29 cases were performed DSA imaging,the residual stenosis rate was (19.27 ± 5.62)％,3 cases of vertebral artery in-stent restenosis were reached over 50％.Those 3 cases were give stent angioplasty again and the uncomfortable symptoms disappeared.Conclusion Stenosis opeation can significantly alleviate the symptoms of cerebral ischemia and symptomatic vertebrobasilar artery,and improve the quality of life of patients.However,restenosis should paid more attention.

Objective To study the diagnostic value of mammography and high-frequency ultrasound in diagnosis of early breast carcinoma.Methods Sixty-five female patients with breast carcinoma were all confirmed by surgery and pathological examinations. All the patients were examined by the high-frequency ultrasound as well as mammography.Results The positive diagnostic rate,the display of tumor shadow and malignant microcalcification with high-frequency ultrasound and mammography were as follows :64.6%(42/65)and 46%(30/ 65),62%(40/65)and 20%(13/65),40%(26/65)and 20%(13/65)respectively. The difference was considered statistically significant(P

Adult chondrocytes had been used as seed cells in the previous tissue engineering; however, they possess the weaknesses including the limited proliferative capability in vitro and the liability to aging after amplification. Bone marrow stromal cells (BMSCs) are multipotent cells, which can differentiate into osteoblasts, chondrocytes, and adipocytes. It is of great importance to study the regulation and control of BMSC directed induction because directed differentiation is required in the tissue engineering. During the BMSC differentiation towards chondrocytes, serious kinds of biological inducing factors participate in precise induction as signal factors. The physical factors, such as biomechanical strength and ultrasound, have been shown to be involved in the regulation of BMSC differentiation towards chondrocytes. In terms of tissue repair, apart from biological factors which play an important role in the formation of cartilage tissue, the chondrocyte microenvironment in vivo is indispensable. Bioreactor is a kind of device intended for in vitro tissue culture that incubates the cells or tissues taken from living bodies in simulated physiological environment in vivo. On the basis of original cell culture, the present bioreactors apply biomechanical stimulation to simulate the stressed environment of articular cartilage in vivo.

BACKGROUND:Osteoporosis is characterized by low bone mineral density and/or poor bone microarchitecture leading to an increased risk of fractures. Oral manifestations can be frequently discovered in osteoporosis patients. Osteoporosis therapies have mostly relied on antiresorptive drugs. Parathyroid hormone plays a significant role in osteogenesis and calcium deposition. Intermittent exposure to parathyroid hormone has been widely proved to lead to a net increase in bone formation.
OBJECTIVE: To discuss the possibly celular and molecular mechanism of parathyroid hormone in strengthening the bone mineral density and regulating bone formation.
METHODS: An online search of CNKI and Medline databases was performed for relevant articles using keywords of “parathyroid hormone; osteoporosis; osteoblast; osteogenesis” in Chinese and English, respectively. Relevant articles were summarized from three aspects: effects of parathyroid hormone on differentiation and proliferation of osteoblasts, effects of parathyroid hormone on osteoblast apoptosis, and the relationship of parathyroid hormone with Wnt/beta-catenin pathway and other cytokines. According to inclusion criteria, 41 articles were retained at last.
RESULTS AND CONCLUSION:Parathyroid hormone exerts an effect on parathyroid hormone type I receptor, triggering a classic G protein signaling pathway. Parathyroid hormone mainly works through protein kinase A signaling pathway, adjusting its downstream c-reactive protein. Intermittent use of parathyroid hormone can increase osteoblast proliferation, increase osteoblast runx2 and osteocalcin at mRNA and protein levels, inhibit osteoblast apoptosis by against oxidative stress, so as to promote osteogenesis.

Objective To discuss the operative methods,clinical effect and safety of endovascular stenting in treatment of upra-arch extra intracranial artery stenosis.Methods Symptomatic carotid artery stenosis ＞ 50％,or no symptomatic stenosis ＞ 75％ with upra-arch extra intracranial artery stenosis patients were treated by endovascular stenting,of all patients,85 cases with carotid artery stenosis,37 cases with vertebral artery stenosis,6 cases with subclavian artery stenosis.Results One hundred and twenty-eight patients were treated with 130 vessel,used 131 stents,59 patients used vascular protection,the achievement rate of stent implantation was 100.00％.The degree of stenosis were significantly improved,the degree of stenosis from (87.65 ± 8.70)％ to (14.28 ± 4.87)％.Twenty-six patients appeared transient decline in blood pressure and heart rate,31 patients appeared persistent hypotension and decrease in heart rate.One patient (no using of vascular protection) appeared obhteration in ipsilateral middle cerebral artery,the artery was recanalization after thrombolysis treatment.The rest of 127 patients did not appear intraoperative vascular embolization complications.Eighteen patients appeared perioperative perfusion in transition,1 case happened cerebral hemorrhage (＜ 10 ml).Postoperative symptoms were improved significantly.Followed up for 6-36 months,84 patients had not restenosis in stent,1 patient had symptomless restenosis (＜ 50％).In 37 patients with vertebral artery stenosis,3 patients again appeared ischemia symptoms in postoperative 1 year,digital subtraction angiography (DSA) showed restenosis in stent,the patient was again given endovascular stenting,the symptoms disappeared.Conclusion As long as the correct choice of indications and perioperative treatment properly,the endovascular stenting in treatment of upra-arch extra intracranial artery stenosis has good clinical effect and high security.

Objective To evaluate the safety and effect of mechanical thrombectomy with the stent device in posterior circulation large intracerebral artery occlusions.Methods Arterial embolectomy with the stent device was carried out in 16 patients with posterior circulation large intracerebral artery occlusions(3.5 h than intravenous thrombolysis time window)in the NO.264th Hospital of People Liberation Army,including 8 cases with pure basilar artery occlusion,7 cases with bilateral vertebral artery intracranial segment and basilar artery occlusion,1 case with side of intracranial vertebral artery occlusion.The National Institutes of health neurological deficit score(NIHSS)score,Alberta stroke program early CT(ASPECTS)score,complications,clinical result were analyzed retrospectively.Results Among 16 cases,the time windows were from 7 to 18 h,the time from onset to reperfusion were(13.32±1.57)h.Successful recanalization was obtained in 15 patients(TICI=3),partial recanalization in 1 case(TICI=2a).Three cases with stent angioplasty.Survival in patients with NIHSS score decreased from(24.65±3.63)points on admission to(4.32±1.57)points after three weeks,with statistical difference(P＜0.01).For mRs score at 90 d: 6 cases(37.5％)with 0-1,4 cases(25％)with 2-3,2 cases(12.5％)with 4-5,4 cases died(25.0％,score ASPECTS 4-5).Conclusion The mechanical thrombectomy with the stent device within 24 h can get higher reperfusion rate,fewer complications,and significantly reduce the mortality rate and good clinical outcome in large intracerebral poster circulation artery occlusions patients.

BACKGROUND:3D bioprinting has been used to print a variety of tissues including skin,vascular tissues,liver,cartilage,cardiac tissues,ear,and adipose tissues.OBJECTIVE:To review the application of 3D bioprinting technology in printing tissues or organs and its research progress in oral medicine.METHODS:A computer-based retrieval of PubMed and CNKI was performed to search articles concerning the application of 3D bioprinting technology in printing tissues,organs and stomatology which were published from 2006 to 2016,using the keywords of 3D bioprinting,3D pinting,organs,tissues,tissue engineering,stomatology,oral,cranio-maxillofacial in English and Chinese,respectively.RESULTS AND CONCLUSION:Direct cell-bioprinting is still in its early stage,even though 3D bioprinting has been applied to print various tissues such as skin,vascular tissues,liver,cartilage and cardiac tissues,etc.Although additive manufacturing technology has been widely used for printing different scaffolds of tissues and organs nowadays,there are no successful bioprinted tissues with biological functions in clinical practice.Even in oral medicine,most of the studies still remain in the stage of printing biological scaffolds.It is a long way to solve the problems such as source of cells,materials of biological scaffolds and types of extracellular matrix in the future,due to the complexity of human organism structure and the function expression of various tissues and organs.

BACKGROUND:Bioceramic has similar components compared to human bone tissue and it has shown good ostoconductivity both in vitro and in vivo.Meanwhile,it is biocompatible.So,bioceramics is considered as one of the most promising materials which can be applied to bone tissue engineering.OBJECTIVE:To summarize the properties of bioceramics and the research progress in experimental studies and clinical applications.METHODS:PubMed was searched for relevant articles published during 2000 to 2016 with the key words of bioceramics,hydroxylapatite,calcium phosphate,bioglass,bone tissue engineering in English.RESULTS AND CONCLUSION:Bioceramic materials can be divided into two categories:calcium phosphates and bioactive glass.Calcium phosphates have good biocompatibility and osteoconductivity,while the mechanical property is not so satisfying.Bioactive glass is biocompatible and beneficial to the expression of some osteogenic genes,but it is brittle and weak.Some kinds of bioceramics have already been applied to clinical practice.In recent years,calcium phosphates have also been used as coated materials to improve the properties of tissue-engineered scaffolds.Bioceramics combined with synthetic polymers,shows better mechanical performance and biodegradation.Even so,it still has plenty of problems and challenges as a widely used bone repair material in clinical practice.