ObjectiveTo analyze the effects of high-order scattered X-ray in dose calculation in radiotherapy,to resolve the problem of correcting the dose contribution of secondary and high-order scattering X-ray to the primary scattered X ray,and to provide a support for photon fast dose calculation method of Monte Carlo.MethodsBy the theory of cross-section in interaction between X-ray with material and Monte Carlo calculating results,to analysis the relative importance of primary scattered X-ray,secondary and high-order scattered of X-ray in dose calculation.ResultsThe contribution of secondary and high-order scattered X-ray to dose calculation was very small,it can be corrected to the primary scattered X-ray with a correction factor.ConclusionsThe results show that we can obtain a precise dose calculation for radiotherapy by only to tracking the contribution of primary X-rays and primary scattering X-ray,so,to establishing the database for primary scattering X-ray by Monte Carlo methods is important for fast dose calculation of Monte Carlo method.

Objective To study the spectrum structure of X-ray and simplify the description method of it. Methods By the general program of Monte Carlo Geant4 to study X-ray spectrum structure and angular distribution of X-ray energy spectrum. Results The results of percentage depth doses and profile curves at different depths of any radiation fields in water phantom calculated by Monte Carlo Geant4 were consistent with the measurements. Conclusions In radiotherapy, X-ray with same nominal energy have very similar dosimetry characteristics, this indicates they have very similar energy spectrum and angular distribution of spectrum. the differences of dosimetric details reflect the different details of the X-ray spectrum structure and angular distribution of X-ray energy spectrum. These studies have very important significances to rapidly build precise virtual source modeling for Monte Carlo calculation based on dose curves measurements in water phantom.

Objective To investigate the effects of UVB irradiation and calciu m at different concentrations on the expression of pemphigus antigens by culture d human keratinocytes. Methods Human keratinocyte cultures were treated with eit her 2 mmol/L calcium added to the serum free media, or exposure to UVB irradiat ion. Immunofluorescence staining was performed with sera from patients with pemp higus vulgaris (PV) or pemphigus foliaceus (PF) as the first antigen. Extracts f rom both epidermis and keratinocytes were run on SDS-PAGE according to Laemmli ′s method and transferred to nitrocellulose membrane for immunoblot with PV and PF sera. Results Specific staining with PV sera was always detectable on kerati nocyte culture by immunofluorescence assay with or without high concentrations o f calcium while PF antigen was detected on stratified cells only. However, expos ure to UVB irradiation could not evoke keratinocyte culture express PF antigen. The reactivities were found at 160 kd band with PF sera while at both 160 kd and 130 kd bands with PV sera. Conclusions Monolayer or stratified keratinocytes ca n produce PV antigen, by increasing the concentration of calcium in the culture media, the human cultured kera tinocytes can be induced to stratify and express PFA. Human keratinocytes can not express PF antigen after exposure to UVB in intro.

Objective To explore the bacterial flora distribution characteristics and drug resistance of pus bacterial culture in a‐cute mastitis and to analyze thechange trend of drug resistance spectrum to provide a evidence‐based basis for the rational use of an‐timicrobial agents in clinic .Methods The pus collected from 207 cases of acute mastitis was conducted the bacterial culture .The bacterial identification and antibacterial susceptibility test were performed by adopting the manual experiment combined with the DL‐96 system .Partial drug susceptibility test was performed by combining with the K‐B method .Results Among 207 specimens , 82 strains of pathogenic bacteria were detected with the detection rate of 39 .6% ,including 51 strains (62 .2% ) of staphylococcus aureus ,7 strains (8 .5% ) of pseudomonas aeruginosa ,4 strains (4 .9% ) of staphylococcus intermedius ,4 strains (4 .9% ) of staphy‐lococcus epidermis ,3 strains (3 .7% ) of acid‐producing klebsiella bacteria and each 1 strain of staphylococcus hemolyticus and other 13 kinds of bacterium .The resistance rates of staphylococcus aureus to azithromycin ,erythromycin and clarithromycin were 92 .2% ,84 .3% and 84 .3% respectively ,indicating that macrolides drugs had a higher overall drug resistance rate and were not suitable for selection and use;the resistance rates of moxifloxacin and ciprofloxacin were 3 .9% and 4 .1% respectively ,the MRSA detection rate was 27 .5% .The resistance rates of Pseudomonas aeruginosa to ticarcillin/clavulanic acid was 85 .7% ;the drug resitance rate of cefoperazone was 83 .3% ;which of gentamycin and amikacin was 71 .4% ;which of aztreonam was 14 .3% ;which of ceftazidime was 28 .6% and which of meropenem was 28 .6% .Conclusion The majority of detected bacteria in pus from the pa‐tients with acute mastitis are Staphylococcus aureus ,followed by pseudomonas aeruginosa ,which is different from that reported by other literatures ,showing the bacterial distribution has regional difference .Staphylococcus aureus has high resistance rate to macrol‐ides antibacterial drugs ,but is highly sensitive to ciprofloxacin and moxifloxacin;Pseudomonas aeruginosa has higher resistant rate to ticarcillin/clavulanic and cefoperazone ,but it is highly sensitive to aztreonam ,ceftazidime and meropenem .Empirical medication should be comprehensively considered by combining with drug resistance spectrum of Staphylococcus aureus and Pseudomonas aeruginosa ,and the sensitive drugs should be selected according to the drug susceptibility results after the antimicrobial susceptibili‐ty test for conducting the targeted medication .

Objective To investigate the feasibility of using clustered regularly interspaced short palindromic repeats ( CRISPR)-mediated genome editing to downregulate the expression of programmed cell death protein 1 (PD-1) on primary T cells by using a lentivirus delivery system. Methods Lentivirus vec-tors pLentiCRISPR A1-A6 containing different PD-1 genomic DNA sequences as single guide RNA ( sgRNA) for Cas9 targeting were constructed individually. The lentivirus vectors were tranduced into primary CD4 T cells. Flow cytometry analysis was performed to detect the expression of PD-1 for evaluating the knockout ef-ficiency. Results The lentivirus vectors pLentiCRISPR A1-A6 carrying six different target sites were con-structed and respectively tranduced into primary CD4 T cells. The expression of PD-1 accompanied with the activation of T cells. Co-expression of CD25 and PD-1 was observed on activated T cells. All of the six sites could be targeted by Cas9, of which A2 and A6 sites were more efficient in knocking out the gene encoding PD-1 with a rate of 19% and 29%, respectively. Conclusion This study suggests that it is feasible to knock out the expression of PD-1 on primary T cells by using CRISPR.

Objective To study the action and mechanism of staphylococcal exfoliative toxin A(E-TA)on pemphigus foliaceus antigen(PFA)and pemphigus vulgaris antigen(PVA)expressed on cultured human keratinocytes.Methods Stratified human keratinocytes were incubated with ETA and then stained with sera from patients with pemphigus foliaceus or pemphigus vulgaris as the first antibodies and FITC-la-beled sheep anti-human IgG as the second antibody.Total protein was harvested from the cells pretreated with ETA and run on SDS-PAGE for Western blot with the same antibodies.Simultaneously,supernatants of the keratinocytes before and after ETA treatment were collected for detection of the levels of IL-1?,IL-6with ELISA kits.The caseinolytic activities of the supernatants were tested by spectrometry in which casein was used as a non-specific substrate.Results Down-expression of PFA was shown after ETA treatment while no change of PVA expression was found.The high intensity and continuous linear appearance of fluo-rescent staining before ETA treatment became weak and discontinuous after ETA treatment,which were re-covered gradually in24hours.The degradation of proteins recognized by PF sera after ETV treatment was revealed by Western blot.The decreasing tendency of IL-1?concentration was found in the supernatants of cell culture after ETA treatment,but IL-6level was too low to be detected.Increased caseinolytic activities were found in the supernatants,and declined36hours after ETA treatment.Conclusions ETA acts on PFA expressed on keratinocytes in vitro,which is reversible along with withdrawal of ETA.The mechanism of E-TA act on PFA may be related to proteolytic action instead of promoting cytokine secretion.

Objective To establish a cerebral hemorrhage model in rats by local injection of type Ⅳcollagenase, and explore the factors affecting the speed and volume of hematoma formation Methods A total of 150 healthy male Wistar rats weighing from 200 to 250 g were randomly divided into 3 groups, control, collagenase, and collagenase/heparin groups Animals in those groups received injection of saline, collagenase (0 2 U/?l), and collagenase (same dose) and heparin (2 U/?l) with different volume respectively at the caudate nucleus The volume of the hematoma in the rats ( n =6 at each time point) was observed 6, 12, and 24 h, and 3, 7d after the injection Results Permeation of blood was found in 12 h after injection in control group Hematoma about 3 mm in diameter was found in 3 d after injection in collagenase group, while in collagenase/heparin group, it was found in 24 h Conclusion Cerebral hemorrhage model established by local injection of collagenase/heparin in saline solution is ideal and reliable, and the size of hematoma is in correlation with the volume of solutions injected into the brain

Objective To study the correlation between patellar stability and keen clinical manifestation in adults with Kaschin-Beck disease (KBD).Methods Through a cross-sectional study in September 2016,one hundred and forty-three adult patients with KBD were asked to accept a digital radiographic X-ray (DR) which included positive and lateral slices of knee joint and axis slice of patellar.Meanwhile,every patient must undergo a Lysholm function evaluation for knee joint and morphological measurement on the DR film which included Insall index,lateral patellofemoral angle,sulcus angle,congruence angle,lateral migrating ratio of patella,and patellofemoral index.Then,the regression equation was built and the correlation analysis was made with multiple linear regression test.Results One hundred and forty-three patients' average scores of Insall index,lateral patellofemoral angle,sulcus angle,congruence angle,lateral migrating ratio of patella,patellofemoral index and Lysholm score were 1.10 ± 0.17,(14.49 ± 1.47)°,(138.08 ± 3.86)°,(11.55 ± 2.17)°,(1.34 ± 0.13)％,1.18 ±0.10,and (62.96 ± 6.11) scores.By multiple linear regression test,Insall index (X1),congruence angle (X4),lateral migrating ratio of patella (X5),and patellofemoral index (X6) were selected to enter into the equation;while,lateral patellofemoral angle and sulcus angle were rejected.The multiple linear regression equation was as follows:Y =17.529 + 15.232X5 + 0.950X4 + 15.957X6-4.224X1.The adjusted determination coefficient (R2) of the equation was 0.559.Those indexes which were selected to enter into the equation were ranked from big to small based on the impact on Lysholm as follow:congruence angle,lateral migrating ratio of patella,patellofemoral index,and Insall index.Among them,Lysholm score had a negative correlation with Insall index.Through variance analysis,F valve was 46.642,and P ＜ 0.05,which meant the fitted equation had statistical significance.Conclusion There is significant correlation between the patellar stability and knee Lysholm scoring in adult with KBD,which is reflected with the following parameters from big to small in turn:patellofemoral index,lateral migrating ratio of patella,congruence angle and Insall index.

Objective To analyze the antibody responses in guinea pigs vaccinated with recombi-nant vaccinia virus( rTT) strains expressing transmitted/founder ( T/F) HIV-1 membrane proteins in combi-nation with gp140 protein.Methods Guinea pigs were primed with rTT strains and boosted twice with gp140 protein in every four weeks.Serum samples were collected from guinea pigs before immunization and in 2, 6 and 10 weeks after the last immunization for the detection of HIV-1-specific binding antibodies, neu-tralizingantibodiesandtherelativeavidityofantibodies.Results (1)Thebindingantibodiesspecificto HIV-1 B′/C, B, AE subtypes were efficiently induced by the immunization of rTT-B, rTT-C and rTT-CON vaccinia strains in combination with gp140 protein.The antibody titers ranged from 111 430 to 1 024 000. More antibodies against HIV-1 B′/C and AE subtypes were induced in guinea pigs by the immunization of rTT-C and rTT-CON strains in combination with gp140 protein than those by using rTT-B strain prime-protein boost strategy (P<0.05).No significant differences with the titers of HIV-1 B subtype specific antibody were observed among the guinea pigs immunized with the three strategies.( 2 ) High titers of SF162 and ZM109 neutralizing antibodies were induced in guinea pigs immunized with rTT-B, rTT-C and rTT-CON vac-cinia strains in combination with gp140 protein, ranging from 83.76 to 649.30.No significant differences were found among the three groups.(3) The HIV-1 V1V2-gp70 specific antibodies associated with protec-tive immunity were induced by immunization of the three virus prime-protein boost strategies.No significant differences were observed among them.(4) Antibodies induced in guinea pigs by immunization of the three strategies showed strong affinity to membrane proteins of HIV-1 B′/C, B, AE subtype strains.No significant differences were found among the three immunization strategies.Conclusion A strong humoral immune re-sponse was induced in guinea pigs primed with recombinant vaccinia virus strains expressing T/F virus HIV-1 membrane proteins and boosted with gp140 protein.

Successful pregnancy and delivery of a healthy offspring largely rely on a well-developed placenta. Defects in placental development may lead to various pregnancy complications. However, placenta has been one of the least understood organs. The mechanism of its development and function, as well as the molecular association between placental disorders and pregnancy complications remain unclear, thus become the least known area in the exploration of pregnancy and life. Along with the advances in modern techniques, the understanding of the placenta has been deepened from tissue structure to cellular and molecular level, and gradually toward the omics and systematic biology. In recent years, a number of groundbreaking achievements have been made in the field of placental development, which were summarized in this article. Some relevant international funding programs and future prospects in this area were also discussed.