[en] Objective: To discuss the diagnostic value of multi-slice computed tomography(MSCT) as an imaging technique used for upper vein angiography. Methods: A total of 56 cases were referred for upper limb vein check by MSCT from June 2010 to March 2012. The veins were scanned by using the LightSpeed 16 computed tomography(CT) scanner and reconstructed by using volume rendering, maximum intensity projection, multi-planner formation, and curve planner reformation. Three different layers were selected to measure the CT value of A, B, and C(i.e., the axial image of the cephalic and brachial veins between condyles of the humerus at 5 and 8 cm and the axial image of the subclavian vein). Statistical analysis was conducted by using SPSS 17.0, whereas one-way ANOVA F test was used to analyze the measured CT value(P < 0.05 was considered statistically significant). Results: Out of 56 patients, 14 cases of right upper limb and 21 cases of left upper limb were detected to have deep vein thrombosis. That is, 62.5%(35/56) of the cases were detected by MSCT as compared with 58.9%(33/56) of the cases detected by color Doppler. The CT value of the axial image of the brachial and cephalic veins between condyles of the humerus approximately 5 and 8 cm near the heart was P > 0.05, whereas that of the axial image of the subclavian vein was P > 0.05(F = 0.001). In different layers of vein filled with contrast medium, the CT values were uniform and the differences of the values exhibited no statistical significance between different layers. The contrast medium concentration in the distal part of the upper limb vein was higher than that near the heart, and the differences of the CT values exhibited statistical significance between different layers(F = 1441.52, P < 0.05). Conclusions: In conclusion, the MSCT is a superior technology for upper limb vein imaging because it is able to show the upper limb in an extensive range, display the collateral circulation clearly, identify the causes of hemadostenosis, and predict the occurrence of thrombogenesis. Simultaneously, this technology significantly reduces the dosage of iodine contrast agent, lowers the economic burden of patients, improves the rate of correct diagnosis for lesions, and provides reliable bases for selecting correct methods of treatment in clinics. (authors)

[en] Objective: To discuss the results of terrestrial γ radiation using different monitoring methods. Methods: Five environmental monitoring points and two supervisory monitoring points were selected, and results of γ dose rates from the automatic continuous monitoring (ACM), instantaneous monitoring (IM) and cumulative monitoring (CM) during 2010-2014 were compared. Results: The results at same point showed that γ dose rates monitored by the ACM were the largest, those of the CM were the second, and those of the IM were the smallest. For the same point in the five years, the standard deviations were 0.62 ∼ 6.96 nSv/h and 4.95 ∼ 28.11 nSv/h by using the same and different monitoring methods, respectively. Conclusion: To a certain extent it has been proved that the terrestrial γ radiation monitored by the three methods is scientific and comparable. It is able to guarantee the quality of monitoring data, and it is of great significance to optimize monitoring points in the radiation environment. (authors)

[en] In 2018, the Beijing–Tianjin–Hebei (BTH) area launched the Blue Sky Protection Campaign (BSPC) to control atmospheric pollution. CO₂ emissions could be significantly reduced due to the co-effects of implementing the BSPC. This paper employs the Greenhouse Gas and Air Pollution Interactions and Synergies Asia model to quantitatively evaluate the CO₂ reductions when implementing the BSPC in the BTH region. The results indicate that CO₂ emissions can be reduced by 20.7 Mt (equivalently, a 19.7% reduction in the corresponding baseline scenario), 6.8 Mt (3.8%), and 80.2 Mt (9.2%) by 2020 for Beijing, Tianjin, and Hebei, respectively, as a co-benefit of the BSPC. By 2030, it is estimated that the CO₂ emission reductions will be 37.8 Mt (26.6%), 4.85 Mt (2.5%), and 69.9 Mt (8.6%) for Beijing, Tianjin, and Hebei, respectively. NO_x presents the highest co-effects with CO₂ in each region. From the key sector perspective, sectors of power and heating in Beijing, residential combustion in Tianjin, and industrial combustion in Hebei are the most important sector that presents the highest co-effects on CO₂ emission reductions due to the application of BSPC. We suggest that the implementation of BSPC, specifically the energy control measures in the power and heating, residential combustion, and industrial combustion sectors for Beijing, Tianjin, and Hebei, respectively, have high synergies and can simultaneously reduce CO₂ and other atmospheric emissions. The results contribute to city-level policymaking on facilitating air pollution control and climate change mitigation among different governmental departments. (paper)

[en] Objective: To explore the relationship between positive cervical lymph nodes and distant metastasis after intensity-modulated radiotherapy (IMRT) in patients with nasopharyngeal carcinoma (NPC). Methods: A retrospective analysis was performed on the clinical data of 474 patients who were newly diagnosed with NPC but no distant metastasis and received IMRT from 2010 to 2012. The survival rates were calculated by the Kaplan-Meier method. The log-rank test was used for comparison of survival rates and univariate prognostic-analysis. The multivariate analysis was made by the Cox regression model. Results: In the 474 patients, 400 had positive cervical lymph nodes and 122 had residual masses in the neck after IMRT. The four-year distant metastasis, overall survival, disease-free survival, local relapse-free survival, and distant metastasis-free survival (DMFS) rates were 13.71%(65/474), 82.9%, 81.4%, 93.5%, and 86.3%, respectively. The univariate and multivariate analyses showed that treatment approach,lymph node metastases in lower neck IV/ V_b/V_c regions, the greatest diameter of the positive cervical lymph nodes, the diameter of residual lymph nodes, and time to lymph node recession were independent prognostic factors for DMFS (all P < 0.05). Conclusions: Chemoradiotherapy can reduce the distant metastasis rate after IMRT for NPC. The larger the cervical lymph nodes are, the more likely there are residual masses; the larger the residual cervical lymph nodes are, the higher risk of distant metastasis there is. Large cervical lymph nodes (≥ 6 cm), residual masses larger than 1 cm, and residual masses at 3 months after IMRT are negative prognostic factors for DMFS after IMRT for NPC. Better intervention treatment approaches need to be explored. (authors)

[en] Highlights: • The capacity fade due to SEI increase in a Li-ion battery is modeled. • Different types of fast charging protocols varying with the SOC are evaluated. • The two-step increasing charging protocol results in the lowest capacity fade. • The linear decreasing charging protocol has the lowest charging voltage. This work compares the effect of linear and two-step fast charging protocols on degradation of the Li-ion battery due to the solid electrolyte interphase (SEI) increase with the charging-discharging cycles based on an electrochemical and capacity fade coupled cell model. Since there is still a lack of knowledge regarding how the State of Charge (SOC) – dependent charging profile affects battery degradation, different slopes of the linear charging profile and different combinations of the charging current level for the two-step charging protocol are chosen as sample protocols representing the profiles varying with the SOC. The simulation results indicate that the two-step increasing charging protocol can achieve the lowest capacity fade ratio over 3000 cycles; the linear decreasing charging protocol can achieve the lowest charging voltage increase. The capacity fade due to the SEI layer increase in the negative electrode results in a shift of the stoichiometry coefficient cycling range and therefore a lower cell equilibrium potential and power performance.

[en] A III–V heterojunction tunneling field-effect transistor (TFET) can enhance the on-state current effectively, and GaAs_xSb_1−x/In_yGa_1−y As heterojunction exhibits better performance with the adjustable band alignment by modulating the alloy composition. In this paper, the performance of the cylindrical surrounding-gate GaAs_xSb_1−x/In_yGa_1−y As heterojunction TFET with gate–drain underlap is investigated by numerical simulation. We validate that reducing drain doping concentration and increasing gate–drain underlap could be effective ways to reduce the off-state current and subthreshold swing (SS), while increasing source doping concentration and adjusting the composition of GaAs_xSb_1−x/In_yGa_1−y As can improve the on-state current. In addition, the resonant TFET based on GaAs_xb1−x/In_y Ga_1−y As is also studied, and the result shows that the minimum and average of SS reach 11 mV/decade and 20 mV/decade for five decades of drain current, respectively, and is much superior to the conventional TFET. (paper)

[en] VSe₂ is a typical layered semimetal TMDC, and was thought to be difficult to synthesize for many years. By changing the concentration of precursors and reaction steps in the hydrothermal method, here we successfully synthesize three different shapes of VSe₂: nano-hydrangea (NH), nano-dandelion (ND) and hexagonal disk (HD). The as-prepared VSe₂ HDs have a single-crystalline structure compared with the poly-crystalline structure of NHs and NDs. The as-prepared VSe₂ in these three shapes also demonstrates apparent differences and intrinsic properties both in the nitrogen adsorption–desorption characterizations and UV–vis absorption analysis. Possible growth processes and mechanisms are put forward in detail to further inspire shape-design in other nanoscale materials. (paper)

[en] A photoconductive gain (up to 400%) is observed in a 4-hydroxycyanobenzene (4HCB, C₇H₅NO) bulk organic semiconducting detector, resulting in a high sensitivity of 38.8 μC Gy_air ^-1 s^-1 cm^-2 under 50 kVp X-ray beam irradiation. The gain variation tendency as the function of both the applied bias voltage and the incident X-ray dose rate is revealed. A rising stage at the gain versus dose rate curve is observed at the low-flux range of X-ray irradiation, attributed to the trap-filling process. A deep-trapping dependent model is proposed, in which the hole injection assisted by trapped electrons is responsible for the gain. (author)

[en] Thermal infrared cameras have been widely used to measure temperature as a non-invasive measuring instrument recently. To assess the temperature results of thermal infrared remote sensing, we compared them with the temperature obtained by traditional contact temperature measuring method. A ground remote sensing platform was designed to obtain the thermal infrared temperature of the underlying surface. Meanwhile, the traditional contact method was used to obtain surface temperature synchronously. Afterward, the two kinds of temperature were compared and analyzed. Our results indicate that for the four kinds of underlying surface studied in this paper, the two kinds of temperature all have strong correlation. Furthermore, the mean temperature difference ranges between 0.46 °C and 1.79 °C. Moreover, no significant difference can be observed between the two kinds of the temperature of grassland, tile, and permeable brick when the evaluation is at the level of P = 0.001. (paper)

[en] Objective: To assess the clinical usefulness of CT scan with oral contrast agent in evaluating anatomical structure and normal values of retrocricoarytenoid region. Methods: CT images with oral contrast agent of 43 patients' normal retrocricoarytenoid regions were observed. At the upper margin level of the arytenoid cartilage and cricoid cartilage and the low margin level of the cricoid cartilage, the thicknesses of anterior and posterior walls were measured respectively, and the sum was calculated. Statistical comparisons of the values were made using t-test. Results: Between the male and female, the thicknesses of anterior and posterior walls had no statistically significant difference at the upper margin level of the arytenoid cartilage and cricoid cartilage and the low margin level of the cricoid cartilage (P > 0.05). The sum of male anterior and posterior walls at the upper margin level of the arytenoid cartilage was statistically thicker than that of female and (9.27 ± 2.51 mm vs. 7.96 ± 1.46 mm, P < 0.05). The sum of anterior and posterior walls at the upper or low margin level of the cricoid cartilage did not statistically differ between male and female (P > 0.05). Either male or female, the thickness statistically differed between anterior and posterior walls (P < 0.05). Conclusion: CT scans with oral contrast agent can display the contour and the anatomical structure of the retrocricoarytenoid region clearly. Therefore, the subtle structures in this region can be measured precisely. It can complement the shortage of clinical laryngoscope and provides objective images for detecting early diseases and confirming surgical staging. (authors)