Objective To analyze the genotypic characteristics of T. violaceum, and offer evidence for molecular epidemiological study of causative agents of pediatric tinea capitis, in Xinjiang Uygur Autonomous Region. Methods The PCR-restriction fragment length polymorphisim (RFLP) of the nontranscribed spacer region of ribosomal DNA (rDNA-NTS) was assessed by using 5 restriction enzymes, including HaeⅢ, Bgl Ⅰ,MspⅠ, DdeⅠ and MboⅠ, for 30 clinical isolates of T. violaceum from children with tinea capitis in Xinjiang Uygur Autonomous Region. Nine strains of T. violaceum from Beijing and 2 strains from Taiwan served as the control.Results All the 41 strains of T. violaceum were classified into 12 genotypes with the restriction enzyme Ddel.Ten genotypes were revealed in the 30 strains from Xinjiang; among them, 17 strains showed 7 different genotypes (D, F, G, H, I, J and K) with a high intraspecies diversity in comparison with the Beijing and Taiwan isolates; the remaining 13 strains from Xinjiang showed 3 genotypes, which were shared by the Beijing and Taiwan isolates. Conclusions The T. violaceum isolates from children with tinea capitis in Xinjiang Uygur Autonomous Region have unique genotypes, but also show genetic homogeneity with the strains from Beijing and Taiwan, hinting the genetic diversity of T. violaceum.

Objective To investigate whether the aberrantly expressed HLA class Ⅱ molecules on the follicular epithelial cells of Graves' disease and Hashimoto's thyroiditis present autoantigens. Methods Expressions of HLA class Ⅱ, invariant (Ii) chain and B7 on follicular epithelial cells were detected by labeled streptavidin binding (LSAB) and expression of Ii chain at mRNA level was assayed by in situ hybridization (ISH). Results The expression pattern of HLA class Ⅱ, Ii chain and B7 on epithelial follicular cells from Graves' disease and Hashimoto's thyroiditis is highly heterogeneous. Conclusion Follicular epithelial cells possess the necessary molecular basis for presenting autoantigens and activating T cells, at least in a part of the patients.

BACKGROUND: Bone marrow mesenchymal stem cells is the most promising tissue engineering seed cells because of their strong proliferation and passage ability, multi-directional differentiation potential, as well as no ethical problems and no rejection.OBJECTIVE: To review the recent advances in the directional differentiation of bone marrow mesenchymal stem cells induced by various conditions METHODS: The first author retrieved CNKI, PubMed, Wanfang databases for relevant articles published from January 2001 to September 2016. The keywords were bone marrow mesenchymal stem cells, BMSCs, directional differentiation in Chinese and English, respectively. Literature addressing experimental research and review were selected, and finally 48 articles were included.RESULTS AND CONCLUSION: Bone marrow mesenchymal stem cells can be induced in vitro to differentiate into chondrocytes, osteoblasts, adipocytes, and nerve cells by cytokines, chemical drugs, Chinese herbs and extracts, physical stimulation. To establish feasible induction conditions in vitro and improve cell induction efficiency is the basis for the clinical application of bone marrow mesenchymal stem cells.

Objective Knowledge?based radiotherapy ( KBRT ) can reduce the plan quality variability induced by different experiences between physicians and improve the quality of treatment plans. Methods The Varian Rapid Plan system was used to train a dose?volume histogram ( DVH) prediction model. The obtained model was preliminarily applied to semi?automatic design of the preoperative treatment plans for rectal cancer. Eighty high?quality volumetric modulated arc therapy plans were imported into the model training set of the Rapid Plan system. The structures of the plans were matched to the corresponding labels and codes as listed in the library. The training started after the verification of prescription. The residual plots,regression curves,geometric plots for organ at risk ( OAR) ,in?field DVH plots,and model training logs were examined. After removal of the mismatch, the original plans were assessed to rule out outliers and influential data points. More similar plans may be added for another round of training. Ten KBRT plans were designed using the final model and compared with the clinical plans. Results For the two major OARs,the femoral head and bladder,the average goodness of fit of the principal component were 0?999 415/1.0 and 0?999 963/1.0 for the DVH model,and 0?999 651/1.0 and 0?999 945/1.0 for geometry?based expected dose model,respectively. In all the plans, 11 had Cook ’ s distance values exceeding the tolerance and 4 had studentized residual values exceeding the tolerance. The outliers were all kept in the training set to generalize the scope of the model. The 10 KBRT plans had significantly improved homogeneity indices for PGTV and PTV than the original plans (P=0?00,0?04).The 10 KBRT plans also had significantly reduced D50% to the femoral head and bladder as well as significantly reduced mean doses to the bladder than the original plans (P=0?042,0?000,0?005). Conclusions In this study,the Rapid Plan system is used to train a KBRT model for design of preoperative radiotherapy plans for rectal cancer. The results of preliminary application meet the clinical requirements.

Fetal heart sound is nonlinear and non-stationary, which contains a lot of noise when it is colleced, so the denoising method is important. We proposed a new denoising method in our study. Firstly, we chose the preprocessing of low-pass filter with a cutoff frequency of 200 Hz and the resampling. Secondly, we decomposed the signal based on empirical mode decomposition method (EMD) of Hilbert-Huang transform, then denoised some selected target components with wavelet soft threshold adaptive noise cancellation algorithm. Finally we got the clean fetal heart sound by combining the target components. In the EMD, we used a mask signal to eliminate the mode mixing problem, used mirroring extension method to eliminate the end effect, and referenced the stopping rule from the research of Rilling. This method eliminated the baseline drift and noise at once. To compare with wavelet transform (WT), mathematical morphology (MM) and the Fourier transform (FT), the SNR was improved obviously, and the RMSE was the minimum, which could satisfy the need of the practical application.
Algorithms ; Fetal Heart ; physiology ; Heart Sounds ; Humans ; Signal Processing, Computer-Assisted ; Signal-To-Noise Ratio ; Wavelet Analysis

Objective To investigate the dose distribution and radiation risk of Varian thoracic cone beam computed tomography (CBCT) with default parameters with reference to Monte Carlo simulation and International Commission on Radiological Protection (ICRP) report 110.Methods EGSnrc/BEAMnrc code was used to simulate the material, thickness, and geometry of the kV CBCT source (kVS) to establish the kVS model.A benchmarked MCSIM code was applied to calculate the dose distribution in the ICRP phantom after the scan with the standard thoracic parameters (110 kV, 20 mA, and 262 mAs), and the conversion coefficient of absolute dose was obtained in a spherical phantom following the TG-61 protocol.The results of Monte Carlo simulation were validated by PDD and Profile in a water phantom and the measurement of the absolute dose in the computed tomography dose index (CTDI) phantom and Alderson phantom.The models including BEIR VⅡ were used to evaluate the radiation risks.Results With reference to the criterion of 3%/1 mm, the uncertainties of PDD and Profile were less than 2%.The difference between the measured and calculated values was<2.9% in the CTDI phantom and ≤0.05 cGy in the Alderson phantom.In the ICRP110 phantom, the doses to the left lung, right lung, left breast, right breast, heart, thyroid, trachea, cancellous bone, and cortical bone were 1.28, 1.39, 1.74, 1.80, 1.46, 0.48, 0.88, 0.85, and 1.84 cGy, respectively.The relative risks of ischemic heart disease, breast cancer, lung cancer, thyroid cancer, and tracheal cancer in a standard scan were1.001 , 1.009, 1.019, 1.000, and 1.008, respectively. Conclusions The accumulated dose and long-term risks of CBCT during image-guided thoracic radiotherapy cannot be neglected and should be effectively controlled.

Objective To investigate the differential diagnosis of Reye syndrome and the characteristics of primary carnitine deficiency,and to provide diagnostic strategy for similar cases.Methods There was a case presented with fever,poor response,convulsions and hepatomegaly hospitalized in Wuhan Children's Hospital,and the clinical manifestations were described,the physical examination was comprehensively conducted,the auxiliary examination results were recorded,some pediatric specialists from ICU,neurology department,genetic metabolic department,digestive system department were invited to discuss the case.The treatment was adjusted according to the suggested opinions;the treatment effects and the final diagnosis were tracked.Results The primary diagnosis of the case was central nervous system infection or toxic encephalopathy at the time of admission,but Reye syndrome could not be excluded.Although the cerebrospinal fluid test and brain MRI examination detected nothing abnormal,liver function suggested alanine aminotrans ferase ALT increase,blood sugar decrease,the liver volume increase,which was detected by liver ultrasound.Blood amino acids examination revealed the carnitine level decreased,and it was confirmed as primary carnitine deficiency in the end.L-carnitine was used to treat the disease,and its effect was good.Conclusions Great importance should be attached to children with onset age,physical check-up,and multidisciplinary cooperation.Use monism to explain the illness and the auxiliary inspection as far as possible,so that it can get early diagnosis and treatment,and the outcome is good.

Objective To evaluate the feasibility and dosimetric features of a volume modulated arc therapy (VMAT)-configured model in knowledge-based optimization of fixed-field dynamic intensitymodulated radiotherapy (IMRT) plans based on the Varian RapidPlan system.Methods ① A dose-volume histogram prediction model was trained with 81 qualified preoperative VMAT plans for rectal cancer and then statistically verified.② For clinically approved 10 IMRT plans with the same dose prescription,the above model was used to automatically generate new optimization parameters and dynamic muhileaf collimator (MLC) sequences with field geometry and beam energy unchanged.③ In order to rule out the disparities between different versions,a single algorithm was used to calculate the absolute doses of the original and new plans.④ Statistical analyses were performed on dosimetric parameters after comparable target dose coverage was achieved in the two plans by appropriate normalization.Results On the basis of similar target dose homogeneity and coverage,RapidPlan significantly reduced the doses to the urinary bladder (D50％ by 9.01 Gy,P =0.000;Dmean by 8.08 Gy,P =0.005) and the femoral head (D50％ by 4.20 Gy,P =0.000;Dmean by 3.84 Gy,P=0.005) but significantly elevated the mean total number of monitor units (1211±99 vs.771±79,P=0.000) and the number of fields with multiple MLC carriage groups.The knowledge-based semi-automated optimization caused a significantly larger number of high-dose hotspots but a similar D2％ (52.54 vs.52.71 Gy,P=0.239).Conclusions The VMAT model can be used for the knowledge-based semi-automated optimization of IMRT plans to enhance the efficiency and OAR protection.However,the resulting high-dose hotspots need further manual intervention.

Objective To investigate the relationship between the mutation of ERG11 gene,a target of azole antifungal drugs (fluconazole,itraconazole,voriconazole),and azole-resistance in Candida albicans isolates from patients with AIDS.Methods Ninety-three Candida albicans strains were isolated from patients with AIDS.DNA was extracted from these isolates,and ERG11 gene was amplified by PCR followed by bidirectional sequencing.DNAman software was used to compare the resultant sequence with the reference sequence of ERG11 gene (GenBank accession no.X13296).Then,different base sequences were translated into amino acid sequences to determine whether missense mutations occured.Results A total of 40 mutation sites were identified in these isolates,including 27 silent mutations and 13 missense mutations.One or no missense mutation was detected in Candida albicans strains resistant to 1 antifungal agent,while those resistant to 2 or 3 antifungal agents simultaneously harbored 2 or 3 missense mutations.Conclusion The missense mutations in ERG11 gene are probably connected with azole resistance in Candida albicans.

Objective To compare the performances of four commercially available LINAC daily QA instruments.Methods The dosimetric stability of a LINAC including central axis output,flatness and symmetry were verified and fine-tuned using a 3-dimensional water phantom,dosimeters and ionization chambers.The baseline of the four instruments including LINA-C,QUICK-C,BEAM-C and QA3 were set thereafter.Daily measurements of LINAC were conducted with these instruments respectively and the results were compared.Arbitrary errors (CAX and SYM) beyond TG-142 tolerances were introduced to the LINAC to test the sensibilities of each instrument in detecting these changes.Results Relative to the baseline that were measured by the 3-dimensional water phantom and dosimeters,the results monitored by the four instruments were comparable.The maximum disparities of the CAX,FLAT,and SYM were 0.5％ (LINA-C),-0.45％ (QUICK-C),and 0.5％ (BEAM-C),respectively.All checkers detected the known errors successfully.Conclusions The stabilities of all the four evaluated instruments met the requirements of daily QA for LINAC.LINA-C verifies CAX only.QUICKE-C,BEAM-C and QA3 can be used to perform all the daily QA protocols as suggested by AAPM TG 142 report.They also provide unique additional functions.The setup of baseline determines if the morning checkers could measure the LINAC dosimetric parameters correctly.When an error is alarmed by the morning checker,it is recommended to verify the performance of the instrument first rather than recalibrating the LINAC immediately.