[en] Objective: To compare the irradiated dose to unprotected lymph node stations (LNS) between volume-modulated arc therapy (VMAT) and 5-field intensity-modulated radiotherapy (5F-IMRT) in the treatment of patients with upper thoracic esophageal cancer. Methods: A total of 20 patients were selected for re-planning. LNS were not included in the GTV and CTV, instead, LNS were contoured as normal tissues. However, LNS were not constrained in the VMAT and 5F-IMRT inverse optimization for protection. Dosimetric parameters of conformal index (CI), homogeneity index (HI) of targets, V₉₅, V₁₁₀ of planning target volume (PTV), D_mean V₅, V₂₀, V₃₀ of lung, D_mean V₂₅ of heart, D_max of spinal cord, MU, as well as the equivalent uniform dose (EUD) and V₄₀ of LNS were compared between the two plans. Results: 5F-IMRT was superior in PTV V_95% (t = -9.4, P < 0.05), but worse in terms of CI (t = -5.3, P < 0.05) compared with VMAT. 5F-IMRT reduced the V₅ of lung by 10.9% (t = -7.8, P < 0.05) and the D_max of spinal cord by 9% (t = -10.2, P < 0.05), but increased the MU (t = -6.2, P < 0.05) compared with VMAT. The average EUD and V₄₀ of LNS in upper thoracic were significantly increased by 4.7% and 2.4% in 5F-IMRT compared with VMAT, respectively. The irradiated doses to LNS were significantly associated with the volume of PTV (R = 0.716-0.933, P < 0.05) expect for 106 tbL. Conclusions: The irradiated doses to unprotected LNS were less for IMRT plans and were highly associated with PTV volume in patients with upper thoracic esophageal cancer. (authors)

[en] Objective: To discuss the feasibility of using Amplatzer duct occluder Ⅱ to treat perimembranous ventricular septal defects. Methods: Transcatheter closure by using Amplatzer duct occluder Ⅱ was carried out in two female infants with small perimembranous ventricular septal defect. One female infant was 3 years old. The echocardiogram showed that the diameter of VSD was 5.5 mm in left ventricle side and 2.3 mm in right ventricle side. The distance of the upper border of VSD to aortic valve was 4 mm. The other female infant was 2 years and 10 months old, the diameter of VSD was 7.8 mm in left ventricle side and 2.0 mm in right ventricle side. The distance between the upper border of VSD to aortic valve was 5.8 mm. Results: For one infant the 4 by 4 mm Amplatzer duct occluder Ⅱ and 5 F TorqVue low profile delivery catheter was employed, while for the other infant 3 by 4 mm Amplatzer duct occluder Ⅱ and 4 F delivery catheter was used. In accordance with the standard procedure the arteriovenous pathway was set up first, than the left shed and right shed were released in turn. After the operation, echocardiogram showed that there was no residual shunt and aortic regurgitation in occluded site, but mild atrioventricular regurgitation was seen in one infant. The electrocardiogram performed two days after procedure was normal. Conclusion: Transcatheter closure by using Amplatzer duct occluder Ⅱ is very effective for the treatment of small perimembranous ventricular septal defects in infants. This technique has some advantages such as the use of small delivery catheter, minimally-invasive to the vessels, etc. In a short-term after the operation no complications such as residual shunt, valve regurgitation, arrhythmia, etc. occur. (authors)

[en] Objective: To evaluate the efficacy of multi-fenestrated septal occluder for transcatheter closure therapy of fenestrated atrial septal defects (ASD) in children. Methods: During the period from Oct. 2011 to Feb. 2012 three patients (one female and two males) with fenestrated atrial septal defects were admitted to the hospital. Preoperative routine examinations were carefully conducted and no contra-indications were found. Based on the echocardiography and catheterization findings, the proper balloon and occluder were selected to plug the ASD. Three days after the procedure the patients were discharged from hospital. After leaving hospital the patients were asked to take Asprin (3-5 mg/k/d) orally. Results: Echocardiography showed that one case suffered from type II ASD with three shunt pores as well as PS, and the gradient pressure between PA and RV determined by echocardiography and catheterization was 70 mmHg and 52 mmHg, respectively. The diameter of the valve ring of PA was 14.4 mm and the high-pressure balloon sized 18 by 30 mm (production of BLAT) was used to dilate the PS, and after two times dilatation the gradient pressure was decreased to 36 mmHg. Echocardiography was performed to measure the ASD holes, the diameter of the three holes was 7, 1.8 and 2.9 mm respectively. The distance between two anterior holes was 5.4 mm, while the distance between two posterior holes was 3.6 mm. The distance between the middle hole and the aortic valve was 13.2 mm, and the distance between the middle hole and the mitral valve was 10.3 mm. The total septal length was 28 mm. A 25 mm Cribriform occluder was used. Echocardiography demonstrated that the second patient had ASD with two holes, the bigger one was 4.5 mm, and the small one was 4 mm in diameter. The distance between the two holes was 3 mm, and the length of septum was 35 mm. A 25 mm Cribriform occluder was employed. The remaining patient had multiple ASD with many openings. The bigger hole was about 7.2 mm in diameter, and the other holes assumed a multi-fenestrated septal defect appearance with the biggest opening being 2.5 mm in size. The length of septum was 33 mm. A 30 mm Cribriform was adopted. No residual shunt or valvular regurgitation was found after the procedure. Conclusion: Cribriform occluder can be successfully and safely used in patients with multiple ASD, however, postoperative anticoagulation therapy should be emphasized. (authors)

[en] Objective: To evaluate the effectiveness and feasibility of cutting balloon (CB) therapy in treating pulmonary branch stenosis remained after the surgery for congenital heart diseases in children. Methods: Three patients with pulmonary branch stenosis remained after the surgery for congenital heart disease were admitted to authors' hospital. The patients included 2 males and one female. One male patient had residual left pulmonary branch stenosis and pulmonary atresia after the surgery for tetralogy of Fallot (TOF). The other male patient had residual right pulmonary branch stenosis after the surgery for VSD. The female patient suffered from PA, VSD and PDA, after the surgery the left pulmonary branch stenosis remained. After careful preoperative examinations the cardiac catheterization as well as interventional treatment was carried out. Based on the gradient pressure and the diameter of stenotic vessel suitable CB was used to perform angioplasty. The diameter of CB should be less than the diameter of the native vessel adjacent to impaired vessel. According to the result of dilatation, which was determined by angiography, a larger high- pressure balloon might he used to further dilate the vessel if the gradient pressure was still high. Results: After the dilatation with CB, high-pressure balloon had to be employed in the male patient with TOF and in the female patient. The diameter of stenotic vessel in the male patient increased from preoperative 4.6 cm to postoperative 5.8 cm, while in the female patient it increased from preoperative 4.2 cm to postoperative 5.0 cm. The pressure gradient in the male and female patients decreased from preoperative 35 mmHg and 12 mmHg to postoperative 19 mmHg and 7 mmHg, respe-ctively. In the another male patient with PA and VSD, after CB dilatation the vascular diameter increased from preoperative 4.8 cm to postoperative 5.6 cm, and the pressure gradient decreased from preoperative 12 mmHg to postoperative 6 mmHg. No complications such as pulmonary edema or pulmonary hemorrhage occurred during or immediately after the procedure. Conclusion: For the treatment of pulmonary branch stenosis remained after the surgery for congenital heart diseases in children, cutting balloon therapy is safe and effective with fewer complications. (authors)

[en] Highlights: • A method to assess the impact of traffic measures on air quality is proposed. • Statistical functions are used to analyse the impact of a traffic measure. • Traffic measures are compared for ‘similar days’. • The impact of two traffic measures implemented in Beijing on PM_2.5 are analysed. Air quality traffic-related measures have been implemented worldwide to control the pollution levels of urban areas. Although some of those measures are claiming environmental improvements, few studies have checked their real impact. In fact, quantitative estimates are often focused on reducing emissions, rather than on evaluating the actual measures’ effect on air quality. Even when air quality studies are conducted, results are frequently unclear. In order to properly assess the real impact on air quality of traffic-related measures, a statistical method is proposed. The method compares the pollutant concentration levels observed after the implementation of a measure with the concentration values of the previous year. Short- and long-term impact is assessed considering not only their influence on the average pollutant concentration, but also on its maximum level. To control the effect of the main confounding factors, only the days with similar environmental conditions are analysed. The changeability of the key meteorological variables that affect the transport and dispersion of the pollutant studied are used to identify and group the days categorized as similar. Resemblance of the pollutants' concentration of the previous day is also taken into account. The impact of the road traffic measures on the air pollutants’ concentration is then checked for those similar days using specific statistical functions. To evaluate the proposed method, the impact on PM_2.5 concentrations of two air quality traffic-related measures (M1 and M2) implemented in the city of Beijing are taken into consideration: M1 was implemented in 2009, restricting the circulation of yellow-labelled vehicles, while M2 was implemented in 2014, restricting the circulation of heavy-duty vehicles. To compare the results of each measure, a time-period when these measures were not applied is used as case-control.

[en] Highlights: • Developed an improved ASIF using empirically derived personal travel activity and built environment variables. • Per capita urban passenger transport energy use increases as city size expands. • Behavior targeting policies have national mitigation effects. • National guideline on city transport policies should have spatial and temporal priority. - Abstract: Work on comparing cities in terms of their transport energy consumption and CO₂ emissions in the urban passenger transport sector has rarely been done using detailed travel activity data that takes into account city level differences in terms of economic development, population, and urban form. A personal activity based approach is necessary to better reflect travel behavior change results from different social, economic, urban form, technical, and transportation policy situations in the future. The present study extends the existing activity, modal share, energy intensity, fuel/carbon intensity (ASIF) modeling framework by disaggregating travel activity into key structural components and city-specific factors for 288 prefectural level cities in China. Testable econometric modeling systems were built to link mode split and mode specific travel distances with local economic and urban form characteristics in four different population sizes and two urban form types, based on 187 travel surveys in 108 Chinese cities in the past two decades. Scenarios of energy use and carbon emissions between 2010 (baseline) and 2050 were developed. Results showed that in 2010 urban passenger road transport in China generated 396 Mt CO₂ emissions and per capita urban passenger transport energy use increased as city size expanded. By 2030, under business as usual scenario assumptions, energy use in the urban passenger transport sector comprised 23.2 Mt of gasoline, 1.72 Mt of diesel, 3.36 billion M³ of natural gas, and 0.62 billion kWh of electricity. While national policies targeting travel behavior change have been shown to mitigate emissions to some extent, urban transport policies targeted at specific spatial and temporal drivers of energy demand and emissions may be more effective in meeting policy goals. Short-term policies that promote car-pooling and ride sharing and medium-term policies that increase the cost of driving and promote public transport (such as transit oriented development, walkable neighborhood design, and parking pricing/restraint in city centers) help stabilize carbon emissions over the long term. However, the decision of building polycentric cities might have less significant impact on mitigating urban passenger transport in big cities. Moreover, large-scale promotion of electric vehicles should be designed from a long-term perspective rather than from a short-term one to achieve balanced carbon emissions in regard to the decarbonization process of electricity generation in China.

[en] We have systematically studied the feasibility of CaMnO₃ thin film, an n-type perovskite, to be utilized as the buffer layer for hybrid halide perovskite photovoltaic-thermoelectric device. Locations of the conduction band and the valence band, spontaneous polarization performance, and optical properties were investigated. Results indicate the energy band of CaMnO₃ can match up well with that of CH₃NH₃PbI₃ on separating electron-hole pairs. In addition, the consistent polarization angle helps enlarge the open circuit voltage of the composite system. Besides, CaMnO₃ film shows large absorption coefficient and low extinction coefficient under visible irradiation, demonstrating high carrier concentration, which is beneficial to the current density. More importantly, benign thermoelectric properties enable CaMnO₃ film to assimilate phonon vibration from CH₃NH3PbI₃. All the above features lead to a bright future of CaMnO₃ film, which can be a promising candidate as a buffer layer for hybrid halide perovskite photovoltaic-thermoelectric systems

[en] Inorganic-organolead halide perovskite CH₃NH₃PbI₃ modified BiFeO₃ polycrystalline film has been established. The composite photoelectrode presents much larger open voltage and several magnitudes superior photoelectric conversion performance in comparison to the ordinary BiFeO₃ polycrystalline film. The I-V curve shows that the short-circuit current (J_sc) is 1.74 mA·cm⁻² and open-circuit voltage (V_oc) is 1.62 V, the device's photon to current efficiency is over 1%. The large open voltage and high photovoltaic efficiency is believed to attributed to the spontaneous polarization of composite perovskite induced by BiFeO₃ lattice and modified reduced work function of the modified BiFeO₃ surface. Our results clearly show that the present BiFeO₃-CH₃NH₃PbI₃ planar device is capable to generate a large voltage in macro scale under visible light, leading an approach to further applications on photodetectors and optoelectronic switch.

[en] Highlights: • The ceramics are mainly in spinel phase and cubic cobalt oxide phase. • A perfect sintering temperature of 1450 °C for the Mn–Co–Ni–Mg–Al–Fe–O was proposed. • The NTC characteristic of the ceramics derive from grain boundary resistance R_g_b. - Abstract: The Mn_0_._9Co_1_._2Ni_0_._2_7Mg_0_._5Al_0_._0_3Fe_0_._4_5O_4 negative temperature coefficient (NTC) ceramics derived from nano-particles were sintered at 1380 °C, 1450 °C and 1560 °C, respectively. X-ray diffraction (XRD) result showed that the ceramics sintered at 1380 °C and 1450 °C were mainly in the cubic spinel structure except for a little of tetragonal spinel, and that sintered at 1560 °C was consisted of cubic spinel and cubic cobalt oxide phase. Scanning electron microscopy (SEM) image indicated that the grain size of the ceramic increased sharply when the sintering temperature increased from 1380 °C to 1450 °C, and it changed little when the temperature further increased to 1560 °C, while the porosity was enlarged seriously. Thus a perfect sintering temperature of 1450 °C was proposed. Impedance analysis revealed that the grain resistance R_g showed positive temperature coefficient thermistor characteristic, while the grain boundary resistance R_g_b possessed negative temperature coefficient characteristic. Because the grain boundary resistance R_g_b was two orders of magnitude larger than the grain resistance R_g, the material thus showed negative temperature coefficient thermistor characteristic

[en] Spontaneous polarization behaviors of hybrid perovskite CH_3NH_3PbI_3 film were confirmed by in situ PFM and spectroscopic ellipsometry. The film exhibits uniform spontaneous polarization and ferroelectric domain inversion performance. The fitted dielectric constants spectra agree well with the calculated ones. We attribute the spontaneous polarization behaviors of hybrid perovskite to lone pair electrons, and its outstanding photovoltaic performance partially originates from spontaneous polarization and plasma resonance. This report will facilitate understanding of the instinct physical essence of hybrid perovskite solar cells