BACKGROUND:Silicon plays an essential role in bone development and bioactive silicate glasses pioneered the current era of bioactive materials. Various biomaterials have been developed based on the biological function of silicon. OBJECTIVE:To explore the biological function of silicon and research process of silicon in biomaterials. METHODS: A computer-based retrieval of CNKI, PubMed, SpringerLink and Elsevier ScienceDirect databases was performed to search the relevant literatures concerning the biological function of silicon and its application in biomaterials. Al data were primarily screened to exclude repeated and irrelevant articles. Literatures about the application of silicon in biomaterials were included. RESULTS AND CONCLUSION:A total of 68 eligible English articles are enroled. Silicon plays important chemical and biological roles in bone. Silicon in the extracelular matrix interacts with glycosaminoglycans and proteoglycans during their synthesis and form ionic substitutions in the crystal lattice structure of hydroxyapatite. In addition, the dissolution products of bioactive glass (mainly silicic acid) expose significant influence on the molecular biology of osteoblasts in vitro, and can regulate the expressions of several genes including osteoblastic markers, cel cycle regulators and extracelular matrix proteins. Silicon has been proved to improve the bioactivity of numerous materials and do no harm to their mechanical properties and without cytotoxicity.

Objective To investigate the effect of dexmedetomidine on minimum alveolar concentration (MAC) of isoflurane required to inhibit the body movement during skin incision. Methods Forty-eight ASA Ⅰ or Ⅱ patients aged 40-60 yr with body mass index of 22-27 kg/m2 undergoing elective upper abdominal surgery under general anesthesia were randomly divided into 3 groups: control group (group C, n = 15);low dose dexmedetomidine group (group D1, n = 17) and high dose dexmedetomidine group (group D2, n = 16). The patients were unpremedicated. Dexmedetomidine 0.4 and 0.8 μg/kg in normal saline (NS) 15 ml was infused over 15 min before induction of anesthesia in D1 and D2 groups respectively. Anesthesia was induced with fentanyl-propofol-succinylcholine. The patients were mechanically ventilated after tracheal intubation. Anesthesia was maintained with isoflurane. MAC of isoflurane was determined by up-and-down technique. The initial end-tidal isofiurane concentration was set at 1.0%, 0.8% and 0.6% in C, D1 and D2 groups respectively. Each time the end-tidal isoflurane concentration was increased/decreased by 0.2%. Skin incision was made after 15 min of equilibration, when the twitch height returned to more than 90% of its control value. Movement of body and limbs including swallowing and coughing were carefully looked for when skin incision was made. MAC of isoflurane was the mean of end-tidal concentration of isoflurane of each crossover pair, and 95 % CI was calculated. Results MAC of isoflurane was significantly decreased in D1 and D2 groups as compared with group C and in group D2 as compared with group D1( P ＜ 0.05 or 0.01 ). Conclusion Dexmedetomidine can significantly decrease MAC of isoflurane required to inhibit the body movement during skin incision in a dose-dependent manner.

Objective Corneal endothelial decompensation is caused by many corneal diseases. It often results in severe clinical complications. Endothelial keratoplasty (EK) is a new therapy for corneal endothelial decompensation. This study aimed to investigate a new approach to establishing corneal endothelial decompensation animal model with Descemetorhexis technique in order to better understand the tissue response to EK. Methods Thirty New Zealand white rabbits were randomly divided into three groups according to different surgical procedures; corneal endothelial cells (CEC), Descemet's membrane and corneal endothelial cells (DM + CEC) as well as Descemet' s stripping with endothelial keratoplasty(DSEK) group and 10 eyes for each. The right eyes of rabbits were as surgery eyes. Other 10 rabbits were as DSEK donors. Corneal transparency, anterior chamber response and graft location were examined once per day for two weeks under the slit lamp. Comeal thickness was measured by ultrasound biomicroscope. Corneal endothelial cells were analyzed using vital staining with alizarin red and trypan blue in 2, 4 and 8 weeks after operation. Results The cornea in DM + CEC group remained opaque throughout the observation period. In CEC and DSEK group, corneal clarity was gradually restored and corneal thickness was significantly less than that in the DM + CEC group during the postoperative 8 weeks. There were significant differences in corneal thickness between the DM + CEC group and CEC group or DSEK group during the postoperative 8 weeks (P ＜0. 05). The vital staining showed that most Descemetorhexis area was not covered by endothelial cells even 2 months after surgery. Conclusion A new corneal endothelial decompensation model is successfully established for the study of corneal endothelial keratoplasty, which is helpful for understanding the wound-healing of rabbit corneal endothelium after Descemel' s membrane damage.

Objective:To compare the difference and correlation of HPLC and enzyme-multiplied immunoassay test( EMIT) for the determination of CsA in human whole blood. Methods:A total of 119 clinical samples at different concentrations of CsA were collected and respectively determined by HPLC and EMIT. The difference and correlation of the two determination methods were investigated. Results:There was significant difference in the blood concentrations of CsA determined by HPLC and EMIT(P<0. 05). CsA concen-tration determined by EMIT was 26. 2 ng·ml-1 higher than that determined by HPLC, and 95% CI was (14. 6-37. 7) ng·ml-1 . A satisfactory correlation was achieved between the two methods(r=0. 997 4). Conclusion:There is statistically significant difference in the CsA concentration in whole blood respectively determined by EMIT and HPLC. Attention should be paid to CsA monitoring by E-MIT and HPLC, and relevant adjustment should be carried out.

Objective To investigate the effect of electro-acupuncture on behavior alterations,the expression of amyloid precursor protein(APP),amyloid β-protein(Aβ) proteins and neuroapoptosis in the cerebral cortex in the APPswe/PS1dE9 double transgenic mice with Alzheimer's disease (AD) induced by isoflurane.Methods Sixmonth-old AD mice and wild-type mice at the same age were randomly divided into wile-type control group,AD group,isoflurane group,electro-acupuncture group (N =8).The mice were given pretreatment with electro-acupuncture at Baihui(GV20) acupoint and Yongquan(KI 1) acupoint once a day for 3 successive days,15 min each time.And then the mice in electro-acupuncture group and isoflurane group were exposed to a box full of 1.2％ isoflurane for 4 hours.Morris water maze was used to test the learning and memory abilities of the mice,Western blotting method was used to detect the expression of APP-C83,APP-C99 and Aβ,and terminal deoxynucleotidyl transferase(TdT)-mediated dUTP nick end labeling(TUNEL) was used to detect neuroapoptosis in the cerebral cortex.Results The escape latency of AD group was longer than that of wild-type mice group(P＜0.05),and the latency of isoflurane group was longer than that of AD group (P ＜ 0.05),while the latency of electro-acupuncture group was shorter than that of isoflurane group(P ＜ 0.05).The percentage of retention time in the target quadrant and the times for crossing the target quadrant in isoflurane group were lower than those of AD group (P ＜ 0.05),but were higher in electro-acupuncture group than those in isoflurane group (P ＜ 0.05).APPC83 expression level in isoflurane group was significantly lower than that in AD group (P ＜ 0.05),while APP-C83 expression level in electro-acupuncture group was higher than that in isoflurane group (P ＜ 0.05).APP-C99 expression level in isoflurane group was significantly higher than that in AD group (P ＜ 0.05),and APP-C99 expression level in electro-acupuncture group was lower than that in isoflurane group (P ＜ 0.05).The cortical apoptosis index in isoflurane group was significantly higher than that in AD group (P ＜ 0.05),and the cortical apoptosis index in electro-acupuncture group was lower than that in isoflurane group (P ＜ 0.05).The expression level of Aβ in AD group,isoflurane group and electro-acupuncture group was significantly higher than wild-type control group (P ＜ 0.05).Conclusion Electro-acupuncture can relieve the AD-like neurotoxicity induced by isoflurane and inhibit the decline of learning and memory abilities of AD mice,and the mechanism is probably related with suppressing the overexpression of APP-C99 and reducing the production and accumulation of Aβ,thereby alleviating the neuroapoptosis.

Objective:To explore the application of computer simulation teaching based on GasMan @ software in anesthesiology standardized nursing training. Methods:Thirty-six anesthesia nurses undergoing standardized training were selected as research objects. They were randomly divided into the traditional teaching group (group C) and the computer simulation teaching based on GasMan @ software group (group G), with 18 nurses in each group. All the nurses received the theory test before and after the training, and the practical operation assessment and the teaching satisfaction survey were conducted after the training. SPSS 17.0 was used for independent-samples t test and chi-square test. Results:There was no significant difference in the theoretical test scores of the anesthesia nurses before class between the two groups ( P > 0.05); the theoretical test, practical performance and satisfaction survey of group G were significantly better than those of group C, with statistical significance ( P < 0.05). Conclusion:Computer simulation teaching based on GasMan @ software is in favor of the anesthesia nurse to learn and master the relevant theory of inhalation general anesthesia, especially to improve practical skills.

Objective:To understand the current situation of physicians′ competency in China and statistically analyze its influencing factors, hence providing referential evidences for promoting their competency.Methods:The evaluation scale for Chinese physicians′ competency was developed by referring to sophisticated overseas evaluation frameworks. Based on the electronic platform of the medical alliance, stratified sampling was conducted at 39 hospitals in 13 provinces, from which 2 156 physicians were surveyed, and statistical analysis was made on the current situation and influential factor of their competency in 6 dimensions(medical knowledge, diagnosis and treatment, scientific research and teaching, interpersonal communication, spirit of professionalism, population health)Results:The score range in multiple dimensions of physicians′ competency was between 2.85 and 3.89(5 in total), among which spirit of professionalism dimension scores the highest, and teaching and research dimension scores the lowest. Logistic regression analysis shows that their competency level in 6 dimensions is correlated to a range of factors, including gender, degree, title, supervisor qualifications, standardized training program of specialist physicians, and affiliation or not to teaching hospitals( P<0.05). Conclusions:Their overall competency is expected to be elevated. To name a few, they are lack of teaching and research abilities, and need to conduct clinical-oriented scientific research; they are expected to enrich knowledge structure, and need to embrace a wider concept of health; they need to improve their non-technical service abilities, and should further emphasize their humanistic quality; physicians′ practice competency depends upon their extent of medical education, and ensuring the quality of standardized training becomes the key measure.

A number of studies have shown that the enlarged perivascular spaces (EPVS) are associated with various diseases such as cerebral small vessel disease,Alzheimer's disease,post-stroke depression,and post-stroke cognitive impairment.This article reviews the imaging features,pathophysiological mechanisms and clinical significance of EPVS.

Lacunar stroke is a common ischemic cerebral small vessel disease. It can cause vascular cognitive impairment. Many studies have shown that the number, location, and course of lacunar stroke are closely associated with vascular cognitive impairment. This article reviews the related studies of lacunar stroke and vascular cognitive impairment.