English thesis writing and tutoring process is traditionally loose and open-ended. Both students and teachers enjoy much liberty in the maneuver of different steps in the whole process, which, as it were, may cause a ...English thesis writing and tutoring process is traditionally loose and open-ended. Both students and teachers enjoy much liberty in the maneuver of different steps in the whole process, which, as it were, may cause a series of problems and dissatisfactions, consequently undermining the quality and significance. This paper is intended to explore a streamlined and systematic procedure to ensure both the students and teachers are doing their bit and make due contribution to the thesis perfection.展开更多
AIM:To compare a first diagnostic procedure of transbronchial needle aspiration(TBNA)with selection of endoscopic ultrasound-guided fine-needle aspiration(EUS-FNA)or TBNA for mediastinal lymphadenopathy.METHODS:Sixty-...AIM:To compare a first diagnostic procedure of transbronchial needle aspiration(TBNA)with selection of endoscopic ultrasound-guided fine-needle aspiration(EUS-FNA)or TBNA for mediastinal lymphadenopathy.METHODS:Sixty-eight consecutive patients with mediastinal lymphadenopathy on computed tomography(CT),who required cytopathological diagnosis,were recruited.The first 34 underwent a sequential approach in which TBNA was performed first,followed by EUS-FNA if TBNA was unrevealing.The next 34 underwent a selective approach where either TBNA or EUS-FNA was selected as the first procedure based on the CT findings.RESULTS:The diagnostic yield of TBNA as the first diagnostic procedure in the sequential approach was 62%.In the selective approach,the diagnostic yield of the first procedure was 71%.There was no significant difference in the overall diagnostic yield,but there were significantly fewer combined procedures with the selective approach.CONCLUSION:Selecting either EUS-FNA or TBNA as the first diagnostic procedure achieved a comparable diagnostic yield with significantly fewer procedures than performing TBNA first in all patients.展开更多
Organic-inorganic hybrid perovskite materials have been receiving considerable attention due to their promising applications in many optoelectronic fields. However, the optical bandgap of CH3NH3PbI3 perovskite is stil...Organic-inorganic hybrid perovskite materials have been receiving considerable attention due to their promising applications in many optoelectronic fields. However, the optical bandgap of CH3NH3PbI3 perovskite is still disputed. In order to comprehend the intrinsic characteristics of these materials, we study the near-band-edge optical responses of the solution-processed CH3NH3PbI3 perovskite crystals by photoconductivity and reflectance spectroscopy at room temperature. All these spectra of the CH3NH3PbI3 polycrystals show only one significant absorption edge at 1.58 eV. However, we observe an extra absorption edge at 1.47 eV in CH3NH3PbI3 single crystal. We establish a simple kinetic model of charge annihilation processes to explain why the low-energy structure of the photoconductivity and diffuse reflectance spectra of CH3NH3PbI3 polyerystals disappear, which provides another possibility for understanding the difference in absorption edge. It is noteworthy that this low-energy absorption edge of CH3NH3PbI3 single crystal has, to the best of our knowledge, seldom been reported on organic-inorganic hybrid perovskites. Therefore, the CH3NH3PbI3 single crystal exhibits a relatively wide absorption which makes it a promising candidate for photoelectric applications.展开更多
文摘English thesis writing and tutoring process is traditionally loose and open-ended. Both students and teachers enjoy much liberty in the maneuver of different steps in the whole process, which, as it were, may cause a series of problems and dissatisfactions, consequently undermining the quality and significance. This paper is intended to explore a streamlined and systematic procedure to ensure both the students and teachers are doing their bit and make due contribution to the thesis perfection.
文摘AIM:To compare a first diagnostic procedure of transbronchial needle aspiration(TBNA)with selection of endoscopic ultrasound-guided fine-needle aspiration(EUS-FNA)or TBNA for mediastinal lymphadenopathy.METHODS:Sixty-eight consecutive patients with mediastinal lymphadenopathy on computed tomography(CT),who required cytopathological diagnosis,were recruited.The first 34 underwent a sequential approach in which TBNA was performed first,followed by EUS-FNA if TBNA was unrevealing.The next 34 underwent a selective approach where either TBNA or EUS-FNA was selected as the first procedure based on the CT findings.RESULTS:The diagnostic yield of TBNA as the first diagnostic procedure in the sequential approach was 62%.In the selective approach,the diagnostic yield of the first procedure was 71%.There was no significant difference in the overall diagnostic yield,but there were significantly fewer combined procedures with the selective approach.CONCLUSION:Selecting either EUS-FNA or TBNA as the first diagnostic procedure achieved a comparable diagnostic yield with significantly fewer procedures than performing TBNA first in all patients.
基金supported by the National Natural Science Foundation of China(Grant Nos.11574302,61474114,61674141,61504134,21503209&11704032)the National Basic Research Program of China(Grant Nos.2015CB921503,2014CB643503&2013CB632805)+1 种基金National Key Research and Development Program(Grant Nos.2016YFB0402303&2016YFB0400101)Key Research Program of Frontier Science,Chinese Academy of Sciences(Grant No.QYZDB-SSW-SLH006)
文摘Organic-inorganic hybrid perovskite materials have been receiving considerable attention due to their promising applications in many optoelectronic fields. However, the optical bandgap of CH3NH3PbI3 perovskite is still disputed. In order to comprehend the intrinsic characteristics of these materials, we study the near-band-edge optical responses of the solution-processed CH3NH3PbI3 perovskite crystals by photoconductivity and reflectance spectroscopy at room temperature. All these spectra of the CH3NH3PbI3 polycrystals show only one significant absorption edge at 1.58 eV. However, we observe an extra absorption edge at 1.47 eV in CH3NH3PbI3 single crystal. We establish a simple kinetic model of charge annihilation processes to explain why the low-energy structure of the photoconductivity and diffuse reflectance spectra of CH3NH3PbI3 polyerystals disappear, which provides another possibility for understanding the difference in absorption edge. It is noteworthy that this low-energy absorption edge of CH3NH3PbI3 single crystal has, to the best of our knowledge, seldom been reported on organic-inorganic hybrid perovskites. Therefore, the CH3NH3PbI3 single crystal exhibits a relatively wide absorption which makes it a promising candidate for photoelectric applications.
