Objective To study environmental safety reference standard values of commonly encountered pathogenic microorganisms, and provide the basis for environmental risk assessment of a high-level biosafety laboratory (BSL).Methods Using human exposure dose calculation methods as the basic principle in combination with microbial hazard evaluation methods , an infectious dose calculation model of human exposure to pathogenic microorganisms by breathing was proposed . Based on research on characteristics of commonly encountered pathogenic microorganisms at home and abroad , the environ-mental safety threshold reference standard and environmental risk protection zone for such microorganisms were obtained . Results An the environmental risk assessment standard calculation method for commonly encountered highly pathogenic microorganisms was proposed , and the minimum infectious dose and environmental safety threshold of seven commonly encountered pathogenic microorganisms were obtained , including SARS coronavirus , highly pathogenic avian influenza virus, Mycobacterium tuberculosis, Bacillus anthracis, Yersinia pestis,Francisella tularensis, and epidemic hemorrhagic fever virus.Conclusion The results can be used as a reference standard of infectious aerosols in a high-level BSL for environ-mental risk assessment , laboratory risk control and emergency management .

Objective To explore imaging manifestations of hepatic epithelioid hemangioendothelioma (HEH). Methods CT and MR images in 14 patients with HEH proven by histopathology were retrospectively analyzed. Plain and two-phase contrast-enhanced CT scan were performed in 5 cases, non-contrast and multiphase contrast-enhanced MR scan were performed in 7 cases, CT and MRI were both performed in 2 cases. Characteristics of CT and MR T2WI images were classified and analyzed. All lesions were classified into three types:multiple, diffuse and solitary form. Results (1) Multiple form of HEH:228 lesions were found in 11 patients, including 178 lesions on MRI and 50 lesions on CT. On T2WI, three or two layered-target-signs with hyperintensity core were found in 79.2% (141/178) of the lesions. Three layer-target-sign included hyperintensity core, hypointensity rim and slightly high signal halo from the inside out. Two layer-target-sign included hyperintensity core and slightly high signal halo from the inside out. Characteristics of dynamic contrast-enhanced scan included peripheral two or three layered-rim-like enhancement in 66.3%( 118/178) of the lesions;peripheral, gradual rim-like enhancement with enhanced core in 27.0%( 48/178) of the lesions;heterogeneously mild enhancement in 2.2%( 4/178) of the lesions;centripetal enhancement in 4.5%( 8/178) of the lesions. Fifty lesions were found in CT, which showed low density nodules or masses with clear margins. Two-layered-black-target sign were found in 42 lesions in contrast-enhanced images, white-target sign were found in 3 cases, and centripetal enhancement was found in 5 cases. (2) Diffuse form of HEH:in one of the two cases of this type, the lesions could not be separated from normal liver parenchyma, gradual enhancements were found along with the vessels in the center of the lesions. (3) Solitary form of HEH: one case, the lesion showed heterogeneous density in non-contrast CT images and gradual enhancement in contrast-enhanced images. Conclusions We found some imaging characteristics of HEH. Two or three layered-target-sign on T2WI and black-target sign, white-target sign on contrast-enhanced images were unique imaging features of HEH.

ObjectiveTo observe the neuroprotective effect of basic fibroblast growth factor(bFGF)on cerebral diffuse axonal injuries (DAI)of rats.Methods40 male SD rats were randomly divided into control group, DAI injury group, bFGF group and DAI saline group. According to the survival time of rats, DAI injury group were divided into five groups, the 6h, 12h, 24h, 72h and 7th day group, The changes of bFGF expression in cerebral cortex were detected by immunohistochemical method from 6h to 7d after DAI. Two hours before DAI, bFGF 10μl was injected into right ventricle in bFGF group. ResultsThe bFGF expression appeared at 6h after DAI, increased at 12h, reached the highest level at 72h, and kept in a high level at 7d.There were obvious differences between 72h group and other groups in DAI injury group (P<0.01),cerebral cortex neurons were obviously decreased by HE staining. In each time group,injured neurons were decreased in bFGF group combined with DAI injury group(P<0.05). ConclusionsbFGF has obvious neuroprotective effect on cerebral diffuse axonal injuries of rats.

Objective To develop a micro-circumstance airtight cabin for in the study of biological aerosols detection with such functions as airflow control and temperature and humidity detection .Methods Wind speed sensors , temperature and humidity sensors , electrical control valves , high efficiency filters and the vacuum pump formed the micro-circumstance regulating system .The techniques of airflow direction control , temperature compensation , air pressure control and aerosol uniformity distribution were used .Numerical simulation of aerosol concentration distribution in the airtight cabin was achieved using Fluent software .The bioaerosol concentration in different locations was tested by experiments .Results The micro-circumstance airtight cabin consisted of an airtight cabin and a control cabin .The control cabin used a single-chip microprocessor to provide air supply and exhaust air to the airtight cabin in a seaparate exhaust mode and cyclic ventilation mode.It worked under a negative pressure condition .Through numerical simulation,the aerosols were distributed through-out the cabin after five minutes of generation and the bottom airflow arrived at the top .The distribution of aerosol concentra-tion was approximately uniform .Conclusion The micro-circumstance airtight cabin is suited to various bioaerosols testing research thanks to its negative pressure working without bioaerosol leakage .

Objective To investigate the aerosolized livability,aerosolized quantity and aerosol particle diameter,etc. of phage D29. Methods Phage D29 aerosol was produced in the aerosol test cabinet in negative pressure laboratory. TSI3321 aerodynamic particle sizer spectrometer was used for detecting the diameter of the aerosol particle. Bioaerosol particle median diameter was tested with Anderson six grade microorganism sampler. The aerosolized livability and quantity of phage D29 were determined by the variations of the concentrations and quantities of phage D29 before and after aerosolization.Results The aerodynamic diameter of phage D29 aerosol was 0.872 μm. Bioaerosol particle median diameter was 2.21 μm. The livability after aerosolization for 5,15,30,45,and 60 min were 89.78％,77.19％,48.86％,33.99％,30.12％,respectively. The aerosolized quantity of phage D29 was 232 μl/min. Conclusion The characters of the aerosolized livability,aerosolized quantity and aerosol particle diameter of phage D29 were thought to be suitable for further research into aerosol inhalation treatment of Mycobacterium tuberculosis infection in animals.

Objective To investigate the effects of inhibition of adenosine monophosphate -activated protein kinase (AMPK) on expressions of cytochrome c (CytC) and caspase -3 and apoptosis in the cerebral cortex after cerebral ischemia-reperfusion injury in mice. Methods Thirty-six male C57BL/6 mice w ere randomly divided into three groups, a sham operation group, a ischemia -reperfusion group, and a AMPK inhibitor group, 12 in each group. A model of middle cerebral artery occlusion w as induced by suture method. The AMPK inhibitor compound C ( 20 mg/kg) w as injected intraperitonealy in the AMPK inhibitor group, the equal volume normal saline w as injected intraperitonealy in the sham operation group and the ischemia-reperfusion group w hen a thread w as inserted. Immunohistochemical staining w as used to detect the expression levels of CytC and caspase-3 and TUNEL method w as used to detect apoptosis at 24 h after ischemia-reperfusion. Results Compared w ith the ischemia-reperfusion group, the numbers of CytC (28.86 ±9.65/HP vs.58.86 ±9.65/HP; t = 7.615, P = 0.030 ) and caspase-3 (7.16 ±5.85/HP vs. 14.36 ±7.85/HP; t =2.548, P =0.035), and TUNEL (67.14 ±8.55/HP vs.95.00 ±13.51/HP; t = 6.891, P = 0.030) positive cels in the cerebral cortex w ere reduced significantly in the AMPK inhibitor group. Conclusion Inhibition of AMPK activity after cerebral ischemia-reperfusion may decrease apoptosis by dow nregulating the expressions of CytC and caspase -3, and play a neuroprotective effect.

Objective To identify the imaging characteristics of calcifying pseudoneoplasms of the neuraxis (CAPNON) and do literature review.Methods Five patients of pathologically-proved CAPNON underwent preoperative MR examination,among which 4 underwent CT scan,2 underwent DSA examination and 1 underwent SPECT. All imaging data were retrospectively analyzed with the emphasis on imaging characteristics.Results Five patients of CAPNON with the diameter of 1.5 to 5.0 cm were found in five patients ( Male 4 ; Female 1 ; age 25 to 60 years old ).Three lesions were located in the skull base,one was located in the cervical spine and one in the foramen magnum and upper cervical segment. All patients underwent MRI examination and 4 of them also took CT scanning.On plain CT,all lesions showed obvious calcification.On T1WI all masses showed hypointensity,and on T2WI 4 of the lesions showed iso- or hypointensity and 1 heterogeneous signal intensity. On contrast-enhanced MR images, peripheral enhancement was demonstrated in 3 lesions,homogeneous enhancement was found in case and one lesion showed no enhancement. The pathologic analysis indicated that inside the lesions were abundant calcification,fibroepithelial tissue and mucoid matrix and no edema was detected around the lesions.Conclusions CAPNON displayed the predilection to male adults and the neuraxis was the predilection site.Calcification on CT images,hypointensity on MR images and peripheral enhancement will be helpful for the diagnosis of CAPNON,but the final confirmation still needs the pathologic results.

Medium filtering efficiency and loading capacity have been evaluated using staphylococcus aureus aerosol,0.75?m NaCl aerosol and Ecoli.F2 phage aerosol,and the face fit factor of actual wearing has been tested under eight predefined activities.The results have shown that the filtration efficiencies of respirator for the three kinds of tested aerosol were above 99 percent,the breathing resistance was less than 250 Pa,and while the load reached 150mg,the breathing resistance of the respirator was still below standards.The fit factors of most of the objects were over the detection capacity of the international standard test set.Our mask offers the best biological protection quality of all the protection equipments in international market.The new biological protective respirator comes to the equal protection result of the half face mask.It can be stored in a flat surface construction form,while be used in the cavity construction style.It is convenient for the troops to be equipped and applied for its smaller physical volume and lighter weight.

Objective To investigate the immunogenicity of mycobacteriophage D29 (phage D 29) in guinea pig models with different delivery routes,and provide information for the application of phages in tuberculosis (TB) therapy.Methods Hartley guinea pigs were administrated with phage D29 through inhalation,intranasal drop or subcutaneous injection for 6 times within 35 days.7H9 broth aerosol inhalation and 0.85 ％ NaCl solution aerosol inhalation were set as solvent and negative controls,respectively.Anti-phage D29 neutralizing antibodies in sera collected weekly were measured by phage reduction neutralizing test (PRNT) and cytokine levels (interleukin-2,interleukin-4 and interferon-γ) were detected at day 35 by enzyme linked immunosorbent assay (ELISA).The data were analyzed by ANOVA and nonparametric test.ResultsNeutralizing antibodies were both negative in two control groups,while low-titer neutralizing antibodies (below 1 ∶ 100) appeared in inhalation and intranasal drop groups only at day 7 and day 14. Nevertheless, neutralizing antibodies were continuously detected in subcutaneous injection group,which increased rapidly and reached 1∶ 16 365.6 at day 35. After 35 days of experiments,serum concentrations of interleukin-2 (x2 =2.7605,P＞0.05),interleukin-4 (F=2.17,P＞0.05) and interferon-γ(F=0.75,P＞0.05) among three treatment groups and two control groups were all not significantly different.ConclusionsThe titer of anti-phage 29 neutralizing antibodies induced by inhalation or intranasal drop administration of phage D29 are both significantly lower than subcutaneous injection.Phage D29 administration doesn’t change the levels of cytokines,which indicates that it may not break the helper T cell (Th)1/Th2 balance.

Objective To compare problem-based learning (PBL) versus lecture-based learning (LBL) in the teaching of rehabilitation medicine in China.Methods All Chinese articles on PBL and LBL in teaching of rehabilitation medicine courses indexed in CBMdisc,Wanfang database,CNKI database,and Google academic search published prior to October 2017 were included.The methodological quality of the selected studies was assessed with'Cochrane Quality Evaluation Standard'.Meta analyses were performed using RevMan 5.3.Results After exclusion of non-eligible citations,a total of 18 documents involving 1943 subjects were satisfied the criteria and were included in this review.Meta-analyses revealed that PBL had a significant improvements on theoretical knowledge examination scores (MD=9.26,95％CI=5.24 to 13.29),practical skills examination scores (MD=12.11,95％CI=5.17 to 19.06),performance excellent rate (RR=3.90,95％CI=2.10 to 7.26),and patient satisfaction rate (RR=8.98,95％CI=4.23 to 19.07) (P＜0.05) among students compared with LBL in teaching of rehabilitation.Conclusion In this meta analysis,PBL is superior to LBL and worthy popularizing in teaching of rehabilitation.