Staphylococcus aureus is a Gram-positive bacterium with strong pathogenicity. With the widespread use of antibiotics， its multi-drug resistance has gradually increased. Among them， methicillin-resistant S. aureus （MRSA） is one of the main pathogens of hospital and community infections. Antimicrobial peptides are short-chain peptides with good antibacterial effects and low drug resistance， which have been widely studied in recent years. This study summarizes the mechanism of action of antimicrobial peptides and related study on antimicrobial peptides against MRSA from different sources. It is found that the mechanisms of action of antimicrobial peptides include targeting bacterial cell membranes， bacterial cells， and bacterial cell walls， etc. Besides isolating antimicrobial peptides with anti-MRSA activity from animals， plants， and microorganisms， antimicrobial peptides can also be obtained through synthetic methods. Among them， GHa-derived peptides from animal sources， Ib-AMP4 from plant sources， Ph-SA from microbial sources， the synthetic peptide LLKLLLKLL-NH2， and so on， due to their effective antibacterial activity， rapid bactericidal speed， and low toxicity， are promising candidates for anti-MRSA drugs.

In the design of oral cone beam CT, cooperation between synergic control of X-ray source, real-time acquisition of flat detector and motion of mechanical structure affects the CT image quality. Based on the full analysis of the flat detector's timing signal characteristics, this research was carried out with microprocessor controller (MCU), complex programmable logic device (CPLD), and light couplings to design and realize synchronous exposure control system. To evaluate whether the design of the synchronous exposure control system in this project could reach the required imaging accuracy, we employed the projected images in the system to analyze its stability, linear consistency, signal to noise ratio and precede the FDK construction.
Cone-Beam Computed Tomography ; Phantoms, Imaging ; Radiography, Dental

Objective To investigate the expression and biological function of miRNA-449 a in lung cancer . Methods A case-control study was conducted in 58 patients diagnosed with lung cancer ( carcinoma and adeno-carcinoma) and normal tissue closely adjacent to tumor.MiRNA-449a simulation was designed and synthesized, was dissolved into two different concentrations as 10 and 20 mg/mL.The expression of miRNA-449a in lung cancer tissues and matched normal tissues were detected by Real time PCR .The expression of luciferase gene was detected by chemiluminescence technique.MiRNA-449a mimics on cell apoptosis was evaluated by MTT assay . Results The mean tissues expression levels of miRNA-449 a in squamous carcinoma group and adenocarcinoma group were 1.48 ±1.63 and 1.52 ±1.54 respectively, and were significantly lower than in control group (2.74 ± 1.55 ) ( P<0.01 ) .The average intensity of fluorescent protein in 10 mg/mL group and 20 mg/mL group were 2 115 ±168 and 1 352 ±159 respectively , and were significantly lower than that in control group ( 4 975 ±115 ) ( P<0.01 ) .Conclusions MiRNA-449 a was down-regulated expression in lung cancer and induced apoptosis .

Objective To explore the effect of orthopedic sub-discipline rotation mode in the postgraduate orthopaedic education. Meth-ods Randomly selected orthopaedic postgraduate students from grade 2011 and grade 2012 (30 students each grade). Students from grade 2011 went through the traditional teaching mode,and students from grade 2012 adopted 2 months of rotation in each sub-discipline. The clini-cal examination results and teaching satisfaction of the two groups were analyzed. Results The clinical examination results and teaching sat-isfaction of students from the two grades showed statistically differences (P<0. 05). Conclusion Orthopaedic sub-discipline rotation teach-ing mode improved the postgraduates in different ways such as orthopaedic theoretical knowledge, clinical skills, case analysis and so on. Meanwhile,the new teaching mode can get students more satisfied.

【Objective】To observe the effects of bamboo leaf extract(BLE)on cerebral ischemia.【Methods】 Effect of BLE(at the concentrations of 10,20 and 40 mg/kg respectively,iv)on rabbit carotid thrombus induced by cotton thread was observed.Meanwhile,the effects of BLE(at the concentrations of 15,30 and 60 mg/kg respectively,iv)on neurological deficit and cerebral infarct size in rats with middle cerebral arterial obstruction(MCAO),as well as the effects of BLE(at the concentrations of 22.5,45,and 90?mg/kg respectively,iv)on mice stroke index,grasping time of decapitated mice and survival time of mice subjecting to bilateral carotid ligation were also observed.【Results】BLE inhibited rabbit carotid thrombosis,improved neurological deficit and reduced cerebral infarct size in MCAO rats(P

Objective To investigate the production path of major histocompatibility complex class Ⅰ chain-related gene A(MICA) antibodies and the impact on the therapeutic efficacy after acute rejection in renal transplantation recipients.Methods Luminex flow cytometry was used to detect antiMICA antibodies and the antibody specificity in 157 pre-transplant kidney transplant recipients randomly selected.The clinical data were collected,anti-MICA antibody production pathway and immunoglobulin types were analyzed,and the impact of IgM anti-MICA antibody and IgM&IgG complex anti-MICA antibodies on acute rejection (AR) incidence and therapeutic efficacy after renal transplantation.Results Of the total 157 recipients,19 recipients were positive for anti-MICA antibodies before renal transplantation in 68 recipients who had history of blood transfusion,pregnancy and transplant sensitized experience (27.9％ ); In 89 recipients having no sensitized experience,MICA antibodies were positive in 26 recipients (29.2％ ) (P＞0.05).In 45 anti-MICA antibody-positive recipients,the anti-MICA antibodies type was IgM in 26 cases having no sensitized experience; and that was IgG and IgM complex in 19 cases having sensitized experience.In 38 antiMICA antibody-positive recipients undergoing kidney transplantation,7 out of 22 IgM anti-MICA antibodies recipients had AR (31.8％) that was reversed by methylprednisolone pulse therapy,and 7out of 16 IgM&IgG complex anti-MICA antibodies recipients had AR (43.8％) and treated with methylprednisolone pulse therapy:reversion in 3 recipients (42.9％),and the graft function loss in 4 recipients.The AR incidence was not associated with the two immunoglobulin types of MICA antibodies(P＞0.05),but there was significant difference in the reversal rate of AR (P＜0.05).Conclusion For non-allergenic history recipients,there exists the classic “natural antibodies” pathway in the production of the anti-MICA antibodies whose immunoglobulin type was IgM.In addition,the reversal effect of AR in recipients with IgM anti-MICA antibodies was much better.We need to attach importance to IgM&IgG complex anti-MICA antibodies for the pre-transplant anti-MICA antibodies in renal transplant recipients,because their AR treatment outcome is poor.

This is the design of a mechanical systems for use in the balanceable system of ambulance, which can keep the medical service bed at the ambulance level, whatever the terrain is. A level detector will detect the level state of the bed and turn it to a signal. The central processing unit will use this signal to analyse and control the movement of the motor. By this design (which uses the rolling rail as a drive transmission and makes three supports of the bed go up and down), the bed will keep level. With the use of this design, the balanceable system of ambulance can counteract 35 degrees. The error is controlled within +/- 1 degree. And the response time is within 0.3 s. The method of registration can be effective for keeping the bed at the ambulance level, and for reducing the chance of making the patient get hurt on the way to hospital.
Ambulances ; Equipment Design ; Humans ; Robotics ; methods ; Transportation of Patients

Objective To investigate the effect of allgeneic hematopoietic stem cell transplantation (allo-HSCT) for β-thalassemia major. Methods Twenty-four β-thalassemia major patients with median age of 4 years (range: 2～15 years), 18 boys and 6 girls, received allo-HSCT.They were classified into class Ⅱ-Ⅲ according to Pesaro thalassemia classification. Twenty-three transplantations were from sibling donor and 1 was from mother, either HLA-identical (n = 23) or HLA-mismatched (5/6) (n = 1). Fifteen patients received bone marrow transplantation (BMT) plus peripheral blood stem cell transplantation (PBSCT), and 9 were subjected to umbilical cord blood transplantation (UCBT). The conditioning regimen consisted of busalphan, cyclophosphamide,fludarabine, plus hydroxyurea before transplantation. Graft-versus-host disease (GVHD) prophylaxis included CsA, methotrexate, antilymphpcute globulin, and mycophenolate mofetil. The median follow-up period was 13 months (range: 3～69). Results Of 24 patients, there were 21 cases (87. 5 %) of disease-free survival, 1 (4. 2 %) transplantation-related death, and 2 cases (8. 3 %) of rejection. Three-year overall survival and disease-free survival rate was 91.7 % and 87. 5 %respectively. The cumulative incidence of grade Ⅱ -Ⅳ acute GVHD and chronic GVHD was 16. 7 %and 20. 3 %, particularly cumulative extensive chronic GVHD was 5. 0 %. Conclusion The sibling donor BMT plus PBSCT is an effective and safe way to treat β-thalassemia major. Cord blood is an important source of hematopoietic stem cells for HSCT. The protocol GVHD prophylaxis of CsA,MTX, ATG with a low-dose and short course of MMF can effectively reduce the incidence of severe acute GVHD, improve the outcome of thalassemia transplantation.

Objective TostudythevalueofquantitativeparametersofDCE-MRIandthreedimensionalarterialspinlabeling(3D-ASL) inpreoperativegliomagrading.Methods 70patientsdiagnosedpathologicallywithinitialgliomawereassessedretrospectively,including 32caseswithlow-gradeglioma(LGG)and38caseswithhigh-gradeglioma(HGG).Allpatientsunderwentconventional,enhanced, DCEand3D-ASL MRIat3.0Tbeforesurgery.TheparametricvaluesofDCEsuchasvolumetransferconstant(Ktrans),extravascular extracellularspacevolumefraction(Ve),therateconstant(Kep),fractionalplasmavolume(Vp),cerebralbloodflow (CBF)andcerebral bloodvolume(CBV)wereobtainedbycorrespondingpost-processingsoftware.ThecerebralbloodflowofASL (ASL-CBF)wasalso obtained.Ttestoftwoindependentsampleswasusedtoanalyzewhetherthemaximumandaveragevaluesofeachparameterwere statisticallydifferentbetweenLGGand HGG.Thediagnosticaccuracyofdifferenttechniqueforgliomagradingwasdeterminedby ROCcurveanalysis.Results ThemaximumvaluesofDCE-Ktrans,Ve,rCBVandmaximumvalueofASL-rCBFwerestatisticallydifferent betweentheHGGandLGG (P＜0.05).AlltheparametricaveragevalueswerestatisticallydifferentbetweentheHGGandLGG (P＜0.05).ThemaximumandaveragevaluesofKtranshadarelativelyhighestdiagnosticefficiencyinallparameters,withtheAUCwere0.986 and0.971,theoptimumthresholdwere0.264and0.068,thesensitivitywere93.3%and94.1%,andthespecificitywere100%and 100%,respectively.ThemaximumvaluesofVe,rCBV,ASL-rCBFandtheaveragevaluesofallparametershadarelativelyhigher diagnosticefficiency.Conclusion ThemaximumvaluesofKtrans,VeandrCBFofDCE,themaximumvalueofASL-rCBFandtheaverage valueofeachparameterwereusefultodistinguishbetweenLGGand HGG.ThemaximumandaveragevaluesofKtransarethebest parametersforidentifyingHGGandLGG.

OBJECTIVETo investigate the actual condition of the sexual physiological and psychological development of the high school students in Yibin in order to get a reliable basis for sexual education of the teenagers.

METHODSWith a proportion of 1% to the whole, 2,770 students were randomly selected from eight high schools in the urban and rural areas of the city. We devised a questionnaire and asked each student to fill in his or her answers presently.

RESULTSSo far as sexual physiological and psychological development was concerned, the high school students of Yibin were found rather precocious, with very little sexual knowledge and psychological endurance in sexual affairs and a relative lack of sexual education.

CONCLUSIONIt is imperative to extend the scope of puberty sexual education in high schools. Teenagers must be taught different kinds of sexual knowledge at different periods of growth as well as how to avoid sexually transmitted diseases and gestation. The sexual knowledge level of the teachers must also be raised. It is a must to establish service or specialist consultation hot lines about sexual knowledge for teenagers. Parents are expected to change their traditional views and assume an active role in the joint efforts of sexual education for their children.

Adolescent ; Child ; China ; Female ; Humans ; Male ; Menarche ; Psychology, Adolescent ; Psychosexual Development ; Rural Population ; Sexual Development ; Students ; psychology ; Surveys and Questionnaires