Measurement of single particle impact charging under an external electric field

Electrostatic charges of granular materials always generate under a strong electric field for both nature and industry. To understand the impact charging of a single particle in such situations is therefore essential. However, the traditional Faraday cup approach has difficulty in determining the impact charge with the electric field. Here, we develop Millikan's method to measure the transferred charge of individual particle collision. The target plate lies beneath the vertical electrodes, and a high-speed camera records the particle movement. The single particle passes through the uniform electric field before and after colliding with the target. We can calculate the impact charge of the particle according to its initial charge and final charge, as well as the impact speed and impact angle. In addition, the electric field strength on the particle above the impact point is determined with the finite element method. The immunity to electric field influence on charge measurement and the ability to obtain relevant parameters make this a powerful tool to characterize charging processes under the electric field.

[AKR1B10 inhibitor enhances the inhibitory effect of sorafenib on liver cancer xenograft]

Objective: To investigate the inhibitory effect of AKR1B10 inhibitor combined with sorafenib on hepatocellular carcinoma (HCC) xenograft growth. Methods: HepG2 xenograft model was established in nude mice. The mice were then randomly divided into four groups: control group, epalrestat monotherapy group, sorafenib monotherapy group and combination treatment group. Tumor volume, tumor weight, T/C ratio and the change in body weight of nude mice in each group were compared to evaluate the curative effect. Immunohistochemistry staining was used to detect the expression of Ki-67 in tumor tissues to evaluate the proliferation status of tumor cells. One-way analysis of variance was used to compare the differences between the groups. Student's t-test was used to test means of two groups and chi-square test was used for multiple samples. Results: The differences of the grafted tumor volume before and after treatment between the control group, epalrestat group, sorafenib group and combined therapy group was 238.940 ± 39.813, 124.991 ± 84.670, -26.111 ± 11.518, and -54.072 ± 17.673(mm(3)), respectively, (F = 37.048, P < 0.001). The tumor mass were 0.273 ± 0.140, 0.158 ± 0.078, 0.079 ± 0.054, 0.045 ± 0.024 (g), (F = 16.594, P < 0.001); T/C ratio were 100%, 57.9%, 28.9%, 16.5%, and Ki-67 positive rate were 23.295 ± 6.218, 13.503 ± 3.392, 7.325 ± 2.257, 4.664 ± 1.189 (%), (χ(2) = 822.203, P < 0.001) . The tumor volume (t = -3.579, P = 0.002) and Ki-67 positive rate (t = -10.003, P < 0.001) in epalrestat monotherapy group were significantly lower than control group. The tumor volume (t = 2.056, P = 0.025), tumor mass (t = 2.101, P = 0.043), and Ki-67 positive rate (t = -2.850, P = 0.005) in combination treatment group were significantly lower than sorafenib monotherapy group. Compared with the control group, the body weight of nude mice in the treatment group decreased to a certain extent, but there was no statistically significant difference between epalrestat monotherapy group and control group (t = -1.599, P = 0.262), and combined therapy and sorafenib monotherapy group (t = -0.051, P = 0.96). Conclusion: AKR1B10 inhibitor enhanced the inhibitory effect of sorafenib on hepatocellular carcinoma xenograft.

[Evaluation uncertainty of power frequency electric field for a Power Project in inner Mongolia]

Objective: With the measurement and uncertainty analysis of the power frequency electric field of the main transformer in the power station, the source of uncertainty, its quantitative calculation, the synthetic assessment method and the reporting method of the measurement results are described to ensure the reliability of the power frequency electric field measurement data. Methods: Referring to the "Measurement of power frequency electric field in the workplace" (GBZ/T189.3-2007) , "Labour environment monitoring technological specification of electric power industry Partt7: Monitoring of power frequency electromagnetic fields" (DL/T 799.7-2010) and "Evaluation and Expression of Uncertainty in Measurement" (JJF 1059.1-2012) , the uncertainty of power frequency electric field measurement data of the main transformer of a power plant was analyzed and the extended uncertainty was obtained. Results: The main source of the uncertainty of power frequency electric field measurement was the measurement of repetitive operation, and the expanded uncertainty of power frequency electric field was 0.09 kV/m. Conclusion: When reporting the results of power frequency electric field measurement, the measurement uncertainty should be used simultaneously to quantify the quality of the measurement results. This method has strong practicability and operability, which can meet the requirements of uncertainty evaluation of power frequency electric field measurement results.

[Predictive value of diffusion-weighted magnetic resonance imaging in patients with esophageal carcinoma treated with radiotherapy: an animal trial]

Objective: To explore the value of diffusion-weighted magnetic resonance imaging (MR-DWI) technique in predicting the efficacy of radiotherapy in patients with esophageal cancer, using experimental animal models. Methods: BALB/c nude mice were subcutaneously injected with Eca-109 cell lines and then tumor formed. The experimental group (16 cases) received a single dose of 15 Gy (6 MV X-rays) delivered by a medical linear accelerator, while the control group (24 cases) did not receive any treatment. The two groups were scanned every other day, started one day before the radiotherapy. The scanning sequences included T1-weight imaging, T2-weight imaging, and DWI. The observation time was 1 month. According to the changes of the tumor volume and apparent diffusion coefficient (ADC) value of the two groups, 7 key time points were selected to observe the difference of cell density and tissue necrosis ratio between the two groups (6 cases in each group). Results: From day 7 after radiotherapy, the experimental group had statistically smaller volume of transplanted tumors than the control group, namely (1.729±0.906) cm(3) vs (2.671±0.915) cm(3)(P<0.05). From day 3 after radiotherapy, the experimental group had statistically higher ADC values [(1.017±0.255)×10(-6) vs (0.833±0.142)×10(-6) mm(2)/s, P<0.05], lower cell density of transplanted tumor (25.56±1.40 vs 33.48±4.18%, P<0.05), and less proportion of tissue necrosis [(32.19±1.21) % vs (29.16±2.16)%, P<0.05], respectively. The ADC value was negatively correlated with cell density (r=-0.703, P<0.001) and positively correlated with tissue necrosis ratio (r=0.658, P=0.003). Conclusions: Single dose of large fraction radiotherapy could inhibit the growth of xenograft. ADC values may change at the early stage prior to morphological changes of tumor. The change of cell density and necrosis ratio of transplanted tumor are in line with the change of ADC value. MR-DWI has the value of early prediction of esophageal cancer radiotherapy efficacy.

Definition of treatment-resistant depression - Asia Pacific perspectives

BACKGROUND

The lack of uniformity in the definition of treatment resistant depression (TRD) within the Asia-Pacific (APAC) region may have implications for patient management. We aimed to characterize the most commonly used TRD definition in selected APAC countries.

METHODS

A systematic literature review of TRD definitions in APAC countries was conducted in Medline and Embase (2010-2016) and conference proceedings (2014 and 2016). TRD guidelines (APAC, Europe regional, US, or international) were also searched. An expert-panel explored APAC nuances in TRD definitions to achieve consensus for a regional-level definition.

RESULTS

Ten guidelines and 89 studies qualified for study inclusion. Among the studies, variations were observed in definitions regarding: number of antidepressants failed (range: ≥1 to ≥3), classes of antidepressants (same or different; 59% did not specify class), duration of previous treatments (range: 4-12 weeks), dosage adequacy, and consideration of adherence (yes/no; 88% of studies did not consider adherence). No TRD-specific guidelines were identified. The emerging consensus from the literature review and panel discussion was that TRD is most commonly defined as failure to ≥2 antidepressant therapies given at adequate doses, for 6-8 weeks during a major depressive episode.

LIMITATIONS

Few studies provided definitions of TRD used in daily clinical practice, and a limited number of countries were represented in the included studies and expert panel.

CONCLUSION

Attaining consensus on TRD definition may promote accurate, and possibly early detection of patients with TRD to enable appropriate intervention that may impact patient outcomes and quality of life.

[Mutational analysis of RNA splicing machinery genes SF3B1, U2AF1 and SRSF2 in 118 patients with myelodysplastic syndromes and related diseases]

目的

探讨RNA剪接体复合物编码基因SF3B1、U2AF1和SRSF2突变在MDS及相关疾病中的突变率、突变特点及临床意义。

方法

以118例MDS及相关疾病患者为研究对象，采用PCR扩增产物直接测序法分别检测SF3B1（K700E）、U2AF1（S34、Q157P）和SRSF2（P95）突变情况。

结果

118例MDS患者中，男76例，女42例，中位年龄53.5（13~84）岁。对全部患者均进行SF3B1（K700E）基因突变分析，SF3B1（K700E）的突变率为19.49%（118例中23例）。在突变的22例MDS患者中，14例环形铁粒幼红细胞（RS）比例≥15%，其中难治性贫血伴环状铁粒幼红细胞（RARS）7例、难治性血细胞减少伴有多系发育异常（RCMD）6例、难治性贫血（RA）1例。与未突变组相比，突变组患者的年龄偏大[58（32~78）岁对51（13~84）岁，z=−1.981，P=0.048]、PLT偏高[121（22~888）×10⁹/L对59（6~1 561）× 10⁹/L，z=−3.305，P=0.001]、骨髓原始细胞比例偏低[0.007（0~0.122）对0.017（0~0.268），z=−2.885，P=0.004]、RS比例偏高[0（0~64%）对0（0~58%），z=−4.664，P<0.001]，HGB偏低[63（40~95）g/L对77（34~144）g/L，z=−3.192，P=0.001]。对105例患者进行U2AF1（S34、Q157P）基因突变分析，突变率为21.90%（105例中23例）。突变组患者各临床特征与未突变组相比差异均无统计学意义。107例患者有SRSF2（P95）突变结果，8例突变，突变率为7.48%，突变组患者初诊时年龄偏高，中位年龄63（50~84）岁，其中难治性贫血伴有原始细胞增多-1（RAEB-1）4例，突变率为14.29%（28例中4例）；MDS转化的急性髓系白血病3例。1例患者同时出现SF3B1（K700E）和SRSF2（P95H）突变，2例患者同时出现SF3B1（K700E）和U2AF1（S34Y）突变。

结论

SF3B1、U2AF1和SRSF2剪接体复合物蛋白编码基因中，仅SF3B1基因突变与环状铁粒幼红细胞增多性贫血密切相关，是该亚型的主要致病基因。