超声辐照参数对体外基因转染效果的影响

目的探讨超声辐照参数对体外基因转染效果的影响及最佳转染条件。方法将293T细胞种植于24孔板内,24h后更换为转染液进行超声辐照,EGFP质粒浓度为1mg/ml,每孔加入15μg;超声强度分为1.5、2.0、2.5W/cm2,辐照时间分为30、45、60s,微泡浓度分为20%、30%、40%;每个参数相互组合并重复4次。转染后72h于荧光显微镜下观察细胞内绿色荧光蛋白的表达,以流式细胞仪检测荧光细胞比例,CCK-8检测细胞存活率,计算转染效率。结果超声声强、辐照时间、微泡浓度均对转染效率有显著影响。辐照条件为2.0 W/cm2、辐照时间45s、微泡浓30%时转染效率最高,可达(35.25±1.40)%。结论超声辐照参数共同影响转染效果,低条件下相互协同,高条件下相互抑制,选择合适的辐照参数是超声介导体外基因转染的重要因素。     

Inclusion of fenofibrate in a series of mesoporous silicas using microwave irradiation

A selection of porous silicas were combined with a model drug using a recently developed, controlled microwave heating process to determine if the application of microwave irradiation could enhance subsequent drug release. Five mesoporous silica types were investigated (core shell, core shell rehydrox, SBA-15, silica gel, SYLOID®) and, for comparison, one non-porous silica (stober). These were formulated using a tailored microwave heating method at drug/excipient ratios of 1:1, 1:3 and 1:5. In addition, all experiments were performed both in the presence and absence of water, used as a fluidising media to aid interaction between drug and support, and compared with results obtained using more traditional heating methods. All formulations were then characterised using differential scanning calorimetry (DSC), powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transformation infrared spectroscopy (FT-IR). Pharmaceutical performance was investigated using in vitro drug release studies. A significant enhancement in the release profile of fenofibrate was observed for formulations prepared using microwave heating in the absence of water for five of the six silica based formulations. Of all the formulations analysed, the greatest extent of drug release within the experimental 30 min was the 1:5 core shell rehydrox achieving a total of 86.6 ± 2.8%. The non-porous (stober) particles did not exhibit an increased release of the drug under any experimental conditions studied. This anomaly is thought to be a result of the comparatively small surface area of the silica particles, thus preventing the adsorption of drug molecules.     

微波照射预防阑尾炎术后患儿切口感染20例临床观察

目的研究微波照射预防阑尾炎术后切口感染的临床效果。方法采用回顾性分析的方法,分析了2013年8月3日至2013年11月31日间收治的40例行阑尾炎手术患儿的临床资料,根据术后处理方法不同,将患儿随机分为对照组和治疗组各20例,其中对照组行常规术后处理,治疗组在对照组治疗的基础上实施微波照射,观察分析2组患儿术后切12发生感染的情况、切口愈合的平均时间及治疗情况。结果治疗组总有效率100．0％,对照组为75．0％,2组比较差异有统计意义（P〈0．05）。治疗组切口平均愈合时间为（15．24±2．34）h,患儿感觉良好,切口周围有温热感,止痛、消肿、消炎效果明显,未发生烫伤,无切口感染等并发症发生;对照组切口平均愈合时间为（21．33±2．58）h,有4例（20．0％）患儿出现切口感染,经积极治疗后,症状得以缓解。2组平均愈合时间及切口感染率比较,差异有统计意义（P〈0．05）。结论微波照射可以有效预防阑尾炎术后切口感染,具有良好的临床疗效,值得在临床上推广应用;在微波照射治疗过程中需加强护理,防止烫伤。     

Correlation between Defects and Electrical Performances of Ion-Irradiated 4H-SiC p–n Junctions

In this study, 4H-SiC p–n junctions were irradiated with 700 keV He⁺ ions in the fluence range 1.0 × 10¹² to 1.0 × 10¹⁵ ions/cm². The effects of irradiation were investigated by current–voltage (I–V) and capacitance–voltage (C–V) measurements, while deep-level transient spectroscopy (DLTS) was used to study the traps introduced by irradiation defects. Modifications of the device’s electrical performances were observed after irradiation, and two fluence regimes were identified. In the low fluence range (≤10¹³ ions/cm²), I–V characteristics evidenced an increase in series resistance, which can be associated with the decrease in the dopant concentration, as also denoted by C–V measurements. In addition, the pre-exponential parameter of junction generation current increased with fluence due to the increase in point defect concentration. The main produced defect states were the Z_1/2, RD_1/2, and EH_6/7 centers, whose concentrations increased with fluence. At high fluence (>10¹³ ions/cm²), I–V curves showed a strong decrease in the generation current, while DLTS evidenced a rearrangement of defects. The detailed electrical characterization of the p–n junction performed at different temperatures highlights the existence of conduction paths with peculiar electrical properties introduced by high fluence irradiation. The results suggest the formation of localized highly resistive regions (realized by agglomeration of point defects) in parallel with the main junction.     

UV-Sensitivity of Shiga Toxin-Converting Bacteriophage Virions Φ24B, 933W,P22, P27 and P32

Shiga toxin-converting bacteriophages (Stx phages) are present as prophages in Shiga toxin-producing Escherichia coli (STEC) strains. Theses phages can be transmitted to previously non-pathogenic E. coli cells making them potential producers of Shiga toxins, as they bear genes for these toxins in their genomes. Therefore, sensitivity of Stx phage virions to various conditions is important in both natural processes of spreading of these viruses and potential prophylactic control of appearance of novel pathogenic E. coli strains. In this report we provide evidence that virions of Stx phages are significantly more sensitive to UV irradiation than bacteriophage λ. Following UV irradiation of Stx virions at the dose of 50 J/m², their infectivity dropped by 1–3 log₁₀, depending on the kind of phage. Under these conditions, a considerable release of phage DNA from virions was observed, and electron microscopy analyses indicated a large proportion of partially damaged virions. Infection of E. coli cells with UV-irradiated Stx phages resulted in significantly decreased levels of expression of N and cro genes, crucial for lytic development. We conclude that inactivation of Stx virions caused by relatively low dose of UV light is due to damage of capsids that prevents effective infection of the host cells.     

Accuracy of objective tests for diagnosing adult asthma in symptomatic patients: A systematic literature review and hierarchical Bayesian latent-class meta-analysis

BackgroundWe obtain summary estimates of the accuracy of additional objective tests for the diagnosis of adult asthma using systematic review and meta-analysis of diagnostic test accuracy studies.MethodsMedline, Embase, and other relevant electronic databases were searched for papers published between January 1989 and December 2016. Studies were included if they evaluated the diagnostic accuracy of objective tests, including airway reversibility (AR), airway hyperresponsiveness (AHR), and fractionated exhaled nitric oxide (FeNO) for the diagnosis of adult asthma in patients with symptoms suggestive of asthma. If papers were assessed appropriate using the adapted QUADAS-2 tool, meta-analysis was conducted using the hierarchical bivariate model. This hierarchical model accounts for both within and between study variability.ResultsSixteen studies reported the performance of the evaluated objective tests at presentation. For diagnosis of adult asthma, overall sensitivity and specificity for AR were 0.39 (95% confidence interval [CI] 0.18 to 0.66) and 0.95 (95% CI 0.86 to 1.00); for AHR, 0.86 (95% CI 0.61 to 1.00) and 0.95 (95% CI 0.77 to 1.00); for FeNO, 0.65 (95% CI 0.53 to 0.77) and 0.83 (95% CI 0.75 to 0.90). Comprehensive comparison of three diagnostic tools for adult asthma using the back-calculated likelihood rate (LR) showed that AR and AHR corresponded to a higher LR+, and AHR gave a lower LR-.ConclusionsIn the current situation of no gold standard for diagnosis of adult asthma, AR and AHR are appropriate for ruling-in the true diagnosis, and AHR is superior for ruling-out a diagnosis. Since each objective test had a specific characteristic, it should be chosen depending on the situation, such as the capacity of the institution and the conditions of patients.     

Health and functional status of adult recipients 1 year after allogeneic haematopoietic stem cell transplantation

Increasing numbers of patients are surviving after allogeneic haematopoietic stem cell transplantation (SCT). Among these patients, a number of late complications have been described but few data on the risk factors of these long-term effects of SCT are available. We report the analysis on 105 adult patients, surviving free of haematological disease at a median time of 15 months after SCT. At the time of screening, 52% had returned to work, general health status was normal in 67% and 47% were sexually active. Female patient gender odds ratio (OR) 2.9 (P = 0.01) and age > 25 years (OR = 3.2, P = 0.02) were associated with non-return to work. Decreased general status was associated with chronic graft-versus-host disease (GvHD) (OR = 3.2, P = 0.009) and irradiation (OR = 3.6, P = 0.004). Sexual inactivity was associated with younger age (OR = 7.0, P = 0.0002) and chronic GvHD (OR = 3.3, P = 0.006). Risk factors for altered pulmonary function tests included previous smoking habits, irradiation and chronic GvHD. Obstructive lung disease was associated with a previous history of asthma. Sicca syndrome and conjunctivitis were increased in patients with previous acute GvHD and cataracts were less frequent in patients with aplastic anaemia. Persistent impaired hair re-growth was less frequent in patients who received irradiation (OR = 0.18, P = 0.002) but increased in patients with previous acute GvHD (OR = 5.3, P = 0.007). Microalbuminuria was more frequent in irradiated patients (OR = 9.4, P = 0.05). Raised cholesterol was associated with age (OR = 20.8, P < 0.001), previous acute GvHD (OR = 4.7, P = 0.03), steroid use (OR = 6.3, P = 0.001) and familial hypercholesterolaemia (OR = 4.4, P = 0.04). Decreased bone density was associated with chronic GvHD (OR = 3.9, P = 0.001). Thus, using routine tests in adult patients we were able to detect significant numbers of-non-symptomatic complications enabling early treatment.     

中西医结合联合TDP照射治疗盆腔炎性疾病后遗症68例

探讨中西医结合联合TDP（特定电磁波辐射器）照射治疗盆腔炎性疾病后遗症（SPID）的疗效。方法：将104例患者随机分为单纯西医治疗组（对照组）和中西医结合联合TDP照射治疗组（治疗组）。对照组采用头孢曲松钠、奥硝唑等静脉点滴,治疗组采用头孢曲松钠、奥硝唑等静脉点滴外,配合中药口服、灌肠并联合TDP照射。结果：治疗组抗生素使用时间缩短,治愈率和总有效率明显高于对照组（P〈0.01）。结论：中西医结合联合TDP照射治疗SPID疗效明显高于单纯西医治疗。     

MOSFET探测器在全身放疗质量控制中的应用

目的探讨MOSFET探测器在全身放疗质量控制中的价值。方法在源轴距360cm处使用电离室对MOSFET探测器进行标定,同时根据体模入射面、出射面与中间层面的剂量换算关系,利用标定后的MOSFET探测器检测行全身放疗患者的辐射剂量,控制并减少相应误差。结果10＋MOSFET探测器中,有7个最大偏差均〈3％,另3个经再次重新标定后,最大偏差亦〈3％,均可用于临床测量。结论在全身放疗中应用MOSFET探测器能够起到监测治疗剂量、控制误差的作用。