利用市政再生水制备超纯水的实验验证

目前国内制备超纯水多采用"混凝+UF+RO+EDI"等处理工艺,原水一般是地表水或地下水,但是利用市政污水厂的再生水制备超纯水的研究和应用实属罕见.针对该地区再生水水质,建立了一套"臭氧均相氧化+RO+EDI"实验装置,其RO产水电导率<2.77μs/cm,EDI产水电阻率>18 MΩ·m,RO浓水和EDI极水可全部作为循环水场的补水.实验过程中有发现企业现有设备设施存在的缺陷,实验结果可用于指导将来工业化详细设计.

Risk of Lymphoma in Patients With Inflammatory Bowel Disease Treated With Azathioprine and 6-Mercaptopurine: A Meta-analysis

Thiopurine therapy for inflammatory bowel disease (IBD) has been associated with increased risk for lymphoma. We estimated the relative risk of lymphoma in patients with IBD exposed to thiopurines and compared relative risk values derived from population-based studies with those from referral center–based studies. We investigated whether active use increased risk compared with past use, and whether sex, age, or duration of use affects risk of lymphoma. We searched MEDLINE, EMBASE, and Cochrane databases, as well as conference abstracts and international publications, for the terms "6-MP and lymphoma," "6-mercaptopurine and lymphoma," "thiopurines and lymphoma," "azathioprine and cancer and IBD," "azathioprine and malignancy and IBD," "azathioprine and lymphoma," and "lymphoproliferative and thiopurines." Pooled standardized incidence ratios (SIRs) and 95% confidence intervals (CIs) were estimated. The deviance statistic from Poisson models was used to calculate heterogeneity. Eighteen studies (among 4383 citations) met our inclusion criteria. Overall, the SIR for lymphoma was 4.92 (95% CI, 3.10–7.78), ranging from 2.80 (95% CI, 1.82–4.32) in 8 population studies to 9.24 (95% CI, 4.69–18.2) in 10 referral studies. Population studies demonstrated an increased risk among current users (SIR= 5.71; 95% CI, 3.72–10.1) but not former users (SIR= 1.42; 95% CI, 0.86–2.34). Level of risk became significant after 1 year of exposure. Men have a greater risk than women (relative risk= 1.98; P < .05); both sexes were at increased risk for lymphoma (SIR for men = 4.50; 95% CI = 3.71–5.40 and SIR for women = 2.29; 95% CI = 1.69–3.05). Patients younger than 30 years had the highest relative risk (SIR= 6.99; 95% CI, 2.99–16.4); younger men had the highest risk. The absolute risk was highest in patients older than 50 years (1:354 cases per patient-year, with a relative risk of 4.78). Compared with studies from referral centers, population-based studies of IBD patients show a lower but significantly increased risk of lymphoma among patients taking thiopurines. The increased risk does not appear to persist after discontinuation of therapy. Patients over 50 have the highest absolute risk of lymphoma per year on thiopurines, while men under 35 may also be a high risk group. More study is needed to precisely understand groups highest at risk. The risks of lymphoma and potential benefits of therapy should be considered for all patients with IBD.

Body composition study by dual-energy x-ray absorptiometry in familial partial lipodystrophy: finding new tools for an objective evaluation

Familial partial lipodystrophies (FPLD) are clinically heterogeneous disorders characterized by selective loss of adipose tissue, insulin resistance and metabolic complications. Until genetic studies become available for clinical practice, clinical suspicion and pattern of fat loss are the only parameters leading clinicians to consider the diagnosis. The objective of this study was to compare body composition by dual energy X-ray absorptiometry (DXA) in patients with FPLD and control subjects, aiming to find objective variables for evaluation of FPLD. Eighteen female patients with partial lipodystrophy phenotype and 16 healthy controls, matched for body mass index, sex and age were studied. All participants had body fat distribution evaluated by DXA measures. Fasting blood samples were obtained for evaluation of plasma leptin, lipid profile and inflammatory markers. Genetic studies were carried out on the 18 patients selected that were included for statistical analysis. Thirteen women confirmed diagnosis of Dunnigan-type FPLD (FPLD2). DXA revealed a marked decrease in truncal fat and 3 folds decrease in limbs fat percentage in FPLD2 patients (p <0.001). Comparative analysis showed that ratio between trunk and lower limbs fat mass, characterized as Fat Mass Ratio (FMR), had a greater value in FLPD2 group (1.86±0.43 vs controls 0.93±0.10; p <0.001) and a improved accuracy for evaluating FPLD2 with a cut-off point of 1.2. Furthermore, affected women showed hypoleptinemia (FLPD2 4.9±2.0 vs controls 18.2±6.8; p <0.001), insulin resistance and a more aggressive lipid profile. In this study, assessment of body fat distribution by DXA permitted an objective characterization of FLPD2. A consistent pattern with marked fat reduction of lower body was observed in affected patients. To our knowledge this is the first time that cut-off values of objective variables were proposed for evaluation of FPLD2.

A 3-db Quadrature Coupler Suitable for PCB Circuit Design

A quadrature 3-dB coupler, which combines the advantages of a coplanar waveguide and microstrip line structure suitable for single-layer substrate printed circuit board (PCB) circuit design is proposed. As compared to the conventional Lange coupler, the proposed coupler with the advantages of increasing the coupled linewidths and coupling spacing without using extra bonding wires can solve the drawbacks of Lange coupler. In addition, the proposed structure can easily be realized in a single-layer substrate by PCB manufacturing processes to eliminate the effects and uncertain factors from a multilayer substrate. Good agreements between the simulation and measurement in the frequency range from 0.45 to 5 GHz can be seen. With the operation bandwidth ranging from 1.8 to 2.8 GHz, the measured results of the return loss are better than 18.2 dB and insertion losses of coupled and direct ports are approximately 3plusmn0.1 dB; the relative phase difference is approximately 89.8deg. The dimension of the circuit is 2.7 cm times1.6 cm times0.08 cm

新添加剂下KDP晶体快速生长及其性能表征

我们使用优级纯的KH2PO4和超纯水(电阻率≥18.2MΩ·cm)为原料,采用新的添加剂KCl(氯化钾)及EDTA钾盐,使生长溶液的稳定性得到提高,在5L生长槽内生长出51mm×54mm×40mm的KDP单晶,生长速度达到15～20mm/d,并检测了快速生长晶体的重要的应用性能,发现与高质量慢速生长晶体性能相当,可以达到使用要求.

一级反渗透+二级EDI超纯水系统在广州市药品检验所的应用研究

本文介绍了二级EDI膜堆的结构及其工作原理,总结了一级反渗透+二级EDI超纯水工艺在广州市药品检验所超纯水制备系统的应用经验,阐述了在原水含盐量高的情况下,采用一级反渗透+二级EDI超纯水工艺具有节水,节电,运行成本低,产水电阻率高的先进性,得出了一级反渗透+二级EDI超纯水工艺具有普及推广的价值和意义.