The physical basis and imaging principle of diffusion-weighted imaging (DWI) are introduced and focus on the diagnosis and evaluation of brain disease, including cerebral infarction, intracranial tumour, brain abscess and necrotic cystic tumour differential diagnosis. Its application and existent problems are analyzed and views its development foreground.

Epigenetics is a branch of conventional genetics and is an emerging research field in biomedicine.Epigenetic factors regulate gene function and phenotype by the modulation of DNA methylation,histone modification,non-coding RNA such as microRNA expression instead of changing the DNA sequence.Therefore,it is thought to be a discipline associated with life science.Epigenetics is opening new means for understanding ocular development and ocular diseases related to aging and environment,and relevant study is increasingly emphasized because epigenetic inheritance is considered to be a reversible process.Like other ocular tissues,the growth,differentiation,senescence and epithelial-mesenchymal transition (EMT) of lens epithelial cells (LECs) are modulated by epigenetic inheritance.Epigenetic inheritance participates in the regulation of gene phenotype,chromatin structure,non-coding RNAs,and cellular differentiation and potential influent in lens diseases such as cataracts.Therefore it may provide new insight of the pathogenesis of cataracts and development of novel treatment options by vigorously carrying lens research on epigenetics.Domestic ophthalmologists should keep watchful eye to these studies.

Objective To investigate the feasibility of achieving consistent image quality with dose reduction technology in lumber spine MSCT examination with Z-axis automatic tube current modulation (ATCM). Methods Forty-eight patients diagnosed as lumber intervertebral disc protrution scanned twice by MSCT before and after interventional operations with the same coverage from third lumbar vertebra to first sacral vertebra. The first scan (FM) was with fixed tube current of 320 mAs. The follow-up scan was with ATCM with noise index (NI) of 12.0 HU. At the levels of L3-4, L4-5 and 15-S1, image quality, image noise and radiation dose were measured and analyzed. Image quality and radiation dose were compared by paired t-test and the image noise was compared by ANOVA test. Results The dosage of the ATCM had a 31.3% reduction compared with FM, the average DLP was(187.9±66.4)mGy·cm and(273.4±45.4) mGy·cm respectively, where t = 8.205, P < 0.05. The average noise and their deviations for the FM group were (9.8±2.4) HU,(9.9±2.4) HU, and (11.5±3.2) HU at level of L3-4, L4-5, 15-S1, respectively. With ATCM, the average noise was(12.0±0.8) HU, (11.7±0.6) HU, and (11.7±1.4) HU, respectively. There was statistical difference between the two groups (F = 23.31, P < 0.05). The image quality scores for the FM group were (4.7±0.3), (4.5±0.2), (4.5±0.2) and showed no statistical difference to ATCM group (4.6±0.3), (4.5±0.2), (4.5±0.2) at level of L3-4, L4-5, L5-S1, respectively, where t = 1.000, P > 0.050 Conclusion ATCM technique with the noise index setting at 12.0 HU can achieved a 31.3% dose reduction while keep the consistent image quality for lumbar spine MSCT study.

Objective To assess the value of 16-slice spiral CT perfusion in the diagnosis of hyperacute cerebral infarction.Methods Routine and perfusion CT of brain were performed in 20 cases suspected with hyperacute cerebral stroke within 6 hours of symptom onset,the images of plain scan,rCBV,rCBF,MTT and TTP were observed and evaluated. All cases were followed-up with CT after one week.Results Ischemic lesions were found in routine CT in 5 cases,15 cases had negative results at routine CT, and ischemic lesions were showed in all of them by perfusion CT images.rCBV,rCBF distinctly decreased, MTT and TTP obviously prolonged in infarction area,and rCBF decreased, MTT and TTP prolonged and rCBV was normal or up lightly in the penumbra area. The infarction lesions were detected in 15 cases by follow-up CT.Conclusion 16-slice spiral CT perfusion in diagnosis of hyperacute cerebral infarction may be a valuable tool in predicting clinical prognosis.

Objective To observe the clinical efficacy and adverse reactions between pemetrexed plus cisplatin and paclitaxel plus cisplatin in the treatment of advanced non-small cell lung cancer (NSCLC).Methods Forty-two cases with non-small cell lung cancer in our hospital from June 2013 to June 2015 were selected.Patients were randomly divided into observation group and control group with 21 cases in each group.The observation group was treated with pemetrexed plus cisplatin and the control group was treated with paclitaxel plus cisplatin.The clinical efficacy and adverse reactions were observed after two courses (21 days of a course) and the statistical analysis was performed.Results In the observation group and control group,response rate and clinical benefit rate were33.33％ (7/21),28.57％ (6/21) and76.19％ (16/21),71.43％ (15/21) respectively.No statistical significance were seen between the two groups (P＞0.05).The rate of hair loss (23.81％) (5/21) and the total number of adverse reactions (18.37％) (27/147) in the observation group were significantly lower than the rate of hair loss (47.62％) (10/21) and the total number of adverse reactions (25.17％) (37/147) in the control group (P＜0.05) No statistical significance was found in the incidence rate of leukopenia,neutropenia,erythropenia,thrombocytopenia,nausea and vomiting and phlebitis between the two groups (P ＞0.05) Conclusion Pemetrexed plus cisplatin is as effective as paclitaxel plus cisplatin in the treatment of advanced NSCLC with less adverse reactions and is much safer than paclitaxel plus cisplatin.Pemetrexed plus cisplatin is more valuable in the clinical treatment of advanced NSCLC.

Objective To understand the etiology of acute hepatitis B (AHB) in adults and investigate the mechanisms of hepatic injury and viral clearance in AHB. Methods One hundred and twenty adult AHB patients were enrolled. Epidemiological and clinical data were collected from the case history records or face-to-face inquiry, and serum samples were collected during hospitalization and follow-up. To observe dynamic patterns of AHB etiology, the markers of hepatitis B virus (HBV) were detected by enzyme-linked immunosorbent assay (ELISA); the level of HBV DNA and HBV genotype were determined by real-time polymerase chain reaction (PCR). Enumeration data were analyzed by non-parametric rank sum test. Comparison between groups was done by t test and that between rates of samples was done by Pearson χ2 test. Results Serum HBV DNA was positive in 48.33% of patients at the time of diagnosis with mean level of 9.84×04 copy/mL, and became undetectable after 12.5 days on average. The median levels of serum alanine aminotransferase (ALT) were 1600 U/L and 1490 U/L in HBV DNA positive and negative groups, respectively (z=-0. 678, P=0. 498). However, the mean levels of serum ALT were (2058±123) U/L and (1393±139) U/L in groups of HBV DNA<1×104 copy/mL and>1×104 copy/mL, respectively, which was significantly different (t=-2.17, P=0. 049). Genotype B accounted for 52.5%, genotype C 42.5 and genotype B and C mixed type 5.0% in 58 patients with HBV DNA positive. Eight patterns of serum HBV markers were presented at first visiting. HBsAg(+), HBeAg(+), anti-HBc(+), anti-HBc IgM(+) and HBsAg(+), anti-HBe(+), anti-HBc(+), anti-HBc IgM(+) were the most common patterns, which accounted for 38.3% and 30.0%, respectively. The dynamic patterns of serum HBV markers of 28 AFIB patients were prospectively followed up. The rate of serum FIBsAg loss was 100. 0% and the median time of negative-conversion was 3 weeks. The cumulative positive rate of anti-HBs was 85.7% after 52 weeks of follow-up. The rate of serum HBeAg loss was 100.0%. HBeAg was negative in 53.6% of patients at first visiting and the rest of patients achieved negative within 4 weeks after onset. The positive rate of anti-HBe was 82.1% during 52 weeks of follow-up. Total anti-HBc (including IgG and IgM) was keeping positive in all patients within 52 weeks, and the negative rate of anti-HBc IgM was 39. 3% after followed up for 52 weeks. Conclusions Rapid HBV clearance andserum HBV marker conversion are significantly different between AHB and chronic hepatitis B.

Objective To evaluate the survival ability of enterovirus 71 (EV71) on different surface and under different climate.Methods Each 1 × 105 tissue culture infective dose 50 (TCID50)EV71 was added on different aseptic surface of plastic,rubber,cloth and wood,respectively.Then these materials were put into biotron (artificial climatic chamber) which could simulate different temperature and moisture.The viruses were recovered after a definite time and then inoculated into Vero cell.The cytopathic effect (CPE) was observed everyday to survey the survival ability of EV71 on different medium surface.Results The recovery rates of EV71 on medium surface ranged from 89 ％-93 ％.The survival time of EV71 on medium surface varied under different climatic conditions.The longest survival time of the virus was observed under the condition of 20 ℃ as the temperature and 80％ as the humidity.After 24 hours of incubation,the infectious titer on plastic surface reduced about 4 lg.After 72 hours of incubation,the infectious titer reduced at least 3.89 lg on cloth and wood surface.Conclusions Temperature and humidity can affect the survival time of EV71 on medium surface,which is longer in the condition of low temperature and high humidity.The survival ability of EV71 on natural cloth and wood surface is better than that on synthetic plastic surface.

Objective To evaluate the correlation of the single nucleotide polymorphisms (SNPs) in CDH13 with non-small cell lung cancer (NSCLC) . Methods 115 patients with NSCLC and 110 healthy controls were included in present study. Two SNPs (rs11646213 and rs7195409) in CDH13 were genotyped using TaqMan method. The association of these two SNPs with NSCLC was calculated and assessed. Results The genotypic and allelic frequencies of rs11646213 showed significant difference between NSCLC patients and the control group (P<0.05), (OR=0.464, 95% CI:0.273~0.789) . The genotypic and allelic frequencies of rs7195409 showed significant difference between the stage I+II and stage III+IV groups (P<0.05), (OR=0.491, 95% CI:0.243~0.991) . Conclusions The rs16146213 has a strong association with NSCLC and G allelic showed a protective effect. The rs7195409 has a strong association between stage I+II and III+IV in NSCLC, and G allele may play a protective role in the development of NSCLC.

An ultrasensitive immunoassay was developed based on As3+ and Hg2+ labeled SiO2 @ Au nanoparticles signal tags and hydride generation-atomic fluorescence spectrometry (HG-AFS) for the detection of carcinoembryonic antigen(CEA) and carbohydrate antigen 19-9 (CA 19-9) respectively. Firstly, amino SiO2@ Au NPs were synthesized for selective absorption of As3+ and Hg2+ ions respectively. Subsequently,the secondary antibody (Ab2) of CEA and CA 19-9 was respectively labeled on As3+ or Hg2+-SiO2 @ Au NPs to prepare the corresponding signal tags for CEA and CA 19-9. Based on the sandwich immunoassay scheme, the tags, two antigen and corresponding first antibodies were bio-conjugated on the bottom of 96-well plate at room temperature to form the immunocomplex. After it was dissolved in alkali solution, As3+ and Hg2+ ions were released in solution and detected by HG-AFS, which concentration was proportional with logarithms of CEA and CA 19-9. The reaction conditions were optimized and the tags were characterized. This assay was based on determination of the concentration of As3+ and Hg2+ for quantization of the corresponding CEA and CA 19-9 antigen. The assay showed a wide linear range from 0. 001 to 100. 0 μg / L for CEA and 0. 01-80 U/ mL for CA 19-9, and a lower detection limit of 0. 5 ng / L and 0. 005 U/ mL respectively. This proposed method was used in real serums samples, the results were consistence with that by ELISA. The immunoassay showed three orders of magnitude of sensitivity lower than that of ELISA, which provides a promising simultaneous immunoassay for the early diagnosis of cancer .

Objective To explore the diagnosis and treatment of poorly differentiated endocardial sarcoma. Method The clinical data of a child with poorly differentiated endocardial sarcoma was retrospectively analyzed. Results One-year-old girl was admitted for diarrhea, polypnea, cyanosis, and cough. Abnormal heart sound was found by auscultation. Leads Ⅱ, Ⅲ, and aVF of ECG showed high peaked P wave. The diagnosis of poorly differentiated endocardial sarcoma was confirmed by echocardiography and pathology after cardiac operation. Three months after discharge from the hospital, the patient suddenly came into coma and died. Conclusion The diagnosis of poorly differentiated endocardial sarcoma is mainly based on clinical manifestations, echocardiography and pathology. Surgical resection is the first choice and chemotherapy and radiotherapy play a supporting role. However, there is no cure for it currently.