Spatial Distribution of Lead Iodide and Local Passivation on Organo-Lead Halide Perovskite

Chen, Sheng,Wen, Xiaoming,Yun, Jae S.,Huang, Shujuan,Green, Martin,Jeon, Nam Joong,Yang, Woon Seok,Noh, Jun Hong,Seo, Jangwon,Seok, Sang Il,Ho-Baillie, Anita American Chemical Society 2017 ACS APPLIED MATERIALS & INTERFACES Vol.9 No.7

<P>We identify nanoscale spatial distribution of PbI2 on the (FAPbI(3))(0.85)(MAPbBr(3))(0.15) perovskite thin film and investigate the local passivation effect using confocal based optical microscopy of steady state and time-resolved photoluminescence (PL). Different from a typical scanning electron microscope (SEM) morphology study, confocal based PL spectroscopy and microscopy allow researchers to map the morphologies of both perovskite and PbI2 grains simultaneously, by selectively detecting their characteristic fluorescent bands using band-pass filters. In this work, we compare the perovskite samples without and with excess PbI2 incorporation and unambiguously reveal PbI2 distribution for the PbI2-rich sample. In addition, using the nanoscale time-resolved PL technique we show that the PbI2-rich regions exhibit longer lifetime due to suppressed defect trapping, compared to the PbI2-poor regions. The measurement on the PbI2-rich sample indicates that the passivation effect of PbI2 in perovskite film is effective, especially in localized regions. Hence, this finding is important for further improvement of the solar cells by considering the strategy of excess PbI2 incorporation.</P>

八股废除与晚清社会心态的嬗变

??(Chen sheng) 교육사학회 2014 교육사학연구 Vol.24 No.1

1901년 청나라 정부는 과거시험 중의 팔고문을 폐지하기로 선포하였으며 이는 청나라 말기 교육개혁이 정식으로 시작됨을 의미하였다. 이러한 과거시험의 변화에 적응하기 위하여, 과거를 준비하는 유생들은 부득이하게 새로운 지식을 공부하고, 당시 사회의 상황과 문제를 이해하였다. 이러한 조치는 과거를 준비하는 유생들이 본래 갖고 있었던 지식구조를 타파하는 것이었으며, 그들로 하여금 이전의 밀봉상태에서 뛰쳐나오게 끔 하였다. 새로운 책을 읽고, 서양의 학문을 공부하고, 신식학당을 다니면서 새로운 교육을 접하는 것은 당시 유생들에게 하나의 새로운 유행이었다. 이러한 과정 중에서 청나라 말기 사회의 교육 관념이나 사람들의 교육에 대한 태도 역시 중요한 변화가 일어났으며, 이는 청나라 말기의 교육 개혁이 중요한 성과를 거둘 수 있었던 기본 조건 중에 하나였다. In 1901, the Qing government announced that abolishing eight-part essay in the imperial examination .it marked the beginning of education reform in late Qing dynasty. In order to adapt this change of the imperial examination, the general scholars have to learn new knowledge, study currrent social situation, which made them change their knowledge structure and get rid of isoation. Reading new book, learning western knowledge and accepting new-type schools become fashions in the scholars at that time. In this course, great change occurred on the ideas of education and attitude to education of the people, which was one of the basic conditions of making the education reform at the beginning of 20th cetury performance smoothly.

Induction of Rhesus Keratinocytes into Functional Ameloblasts by Mouse Embryonic Dental Mesenchyme

Ningsheng Ruan,Chensheng Lin,Xiuqing Dong,Xuefeng Hu,Yanding Zhang 한국조직공학과 재생의학회 2018 조직공학과 재생의학 Vol.15 No.2

Fast progresses in stem cell-based tooth tissue engineering have been achieved in recent years in several animal models including the mouse, rat, dog, and pig. Moreover, various postnatal mesenchymal stem cells of dental origin have been isolated and shown capable of differentiating into odontoblasts and generating dentin. Meanwhile, human ker- atinocyte stem/progenitor cells, gingival epithelial cells, and even iPSC-derived epithelium have been demonstrated to be able to differentiate into functional ameloblasts. Translational medicine studies in the nonhuman primate are irreplaceable steps towards clinical application of stem cell-based tissue engineering therapy. In the present study, we first examined the epithelial stem cell markers in the rhesus skin using immunostaining. Keratinocyte stem cells were then isolated from rhesus epidermis, cultured in vitro, and characterized by epithelial stem cell markers. Epithelial sheets of these cultured keratinocytes, which were recombined with E13.5 mouse dental mesenchyme that possesses odontogenic potential in the presence of exogenous FGF8, were induced to differentiate into enamel-secreting ameloblasts. Our results demonstrate that in the presence of appropriate odontogenic signals, rhesus keratinocytes can be induced to gain odontogenic competence and are capable of participating in odontogenesis, indicating that rhesus keratinocytes are an ideal epithelial cell source for further translational medicine study of tooth tissue engineering in nonhuman primates.

Impaired Na+ −K+-ATPase signaling in renal proximal tubule contributes to hyperuricemia-induced renal tubular injury

Jing Xiao,Xiaoli Zhang,Chensheng Fu,Qingmei Yang,Ying Xie,Zhenxing Zhang,Zhibin Ye 생화학분자생물학회 2018 Experimental and molecular medicine Vol.50 No.-

Hyperuricemia contributes to renal inflammation. We aimed to investigate the role of Na+–K+–ATPase (NKA) in hyperuricemiainduced renal tubular injury. Human primary proximal tubular epithelial cells (PTECs) were incubated with uric acid (UA) at increasing doses or for increasing lengths of time. PTECs were then stimulated by pre-incubation with an NKA α1 expression vector or small interfering RNA before UA (100 μg ml−1, 48 h) stimulation. Hyperuricemic rats were induced by gastric oxonic acid and treated with febuxostat (Feb). ATP levels, the activity of NKA and expression of its α1 subunit, Src, NOD-like receptor pyrin domain-containing protein 3 (NLRP3) and interleukin 1β (IL-1β) were measured both in vitro and in vivo. Beginning at concentrations of 100 μg ml−1, UA started to dose-dependently reduce NKA activity. UA at a concentration of 100 μg ml−1 time-dependently affected the NKA activity, with the maximal increased NKA activity at 24 h, but the activity started to decrease after 48 h. This inhibitory effect of UA on NKA activity at 48 h was in addition to a decrease in NKA α1 expression in the cell membrane, but an increase in lysosomes. This process also involved the subsequent activation of Src kinase and NLRP3, promoting IL-1β processing. In hyperuricemic rats, renal cortex NKA activity and its α1 expression were upregulated at the 7th week and both decreased at the 10th week, accompanied with increased renal cortex expression of Src, NLRP3 and IL-1β. The UA levels were reduced and renal tubular injuries in hyperuricemic rats were alleviated in the Feb group. Our data suggested that the impairment of NKA and its consequent regulation of Src, NLRP3 and IL-1β in the renal proximal tubule contributed to hyperuricemia-induced renal tubular injury.

A Study of the Relationship between Renminbi Exchange Rates and Chinese Stock Prices

Robert W. Rutledge,Khonkar E. Karim,Chensheng Li 한국국제경제학회 2014 International Economic Journal Vol.28 No.3

This study examines the relationship between Chinese renminbi (RMB) exchange rates and Chinese stock prices over the full study period of 20 July 2001 to 21 July 2011. The study also investigates the relationship between the exchange rate and ten industry-specific indices. Also examined is the effect of two specific events on the ‘exchange rate/stock price’ relationship: (1) the easing of exchange rate controls, and (2) the 2008 start of the global financial crisis. A long-run cointegration relationship is found during the full study period between exchange rates and the Shanghai A-share prices, and for nine of ten industry indices. Granger causality in one direction (i.e., from exchange rates to stock prices, or vice versa) or both directions is found for four of the industry-specific indices. Interestingly, both a long-run cointegration relationship and Granger causality are only found during the most volatile period of managed exchanged rates before the global financial crisis. Implications for Chinese monetary policy makers and global investors are provided.

The Study of Maximum Power Point Tracking Control for DFIG based on PSCAD

Li, Dongdong,Wang, Lu,Wang, Yun,Wang, Kaikai,Ye, Chensheng The Korean Institute of Electrical Engineers 2012 The Journal of International Council on Electrical Vol.2 No.3

In recent years, wind power has been developed rapidly. Doubly fed induction generator becomes the main model of wind power become the mainstream due to its high wind energy utilization efficiency and reactive power controllability. On the basis of analyzing the principle and mathematical model of DFIG, dual-loop control system based on the stator flux oriented vector control of DFIG was established, and active and reactive power decoupling control is realized. This paper shows speed control model and power control model which are control modes of the maximum wind power point tracking (MPPT). Simulation results show the control system has good performance and power control mode is more practical and stable than speed control mode.

The association of urinary uric acid excretion with ambulatory blood pressure values in patients with chronic kidney disease

Ying Xu,Xun Zhou,Yuqi Zheng,Haochen Guan,Chensheng Fu,Jing Xiao,Zhibin Ye 대한고혈압학회 2020 Clinical Hypertension Vol.26 No.2

Background: To analyze the association between hypertension and urinary uric acid excretion in patients with chronic kidney disease (CKD). Methods: We screened 87 patients who had been admitted at the Dept of Nephrology, Huadong hospital between April 2017 to April 2019 who had completed 24-h ambulatory blood pressure monitoring and retained 24-h urine biochemical test specimens, thirty adult patients (age ≤ 65 years) with CKD 1–2 stages were recruited in the study. Pearson’s correlation analysis and multiple linear regression analysis were used to study the correlation of urinary uric acid excretion with ambulatory blood pressure values and the association of morning mean diastolic pressure (mMDP), night mean diastolic pressure (nMDP) and CV of dMSP (coefficient of variation of day mean systolic pressure) with fractional excretion of uric acid (FEua) and uric acid clearance rate (Cur). Independent T test was used to compare the differences of blood pressure values in FEua1 (FEua< 6.0%) and FEua2 (FEua≥6.0%) or Cur1 (Cur < 6.2 ml/min/1.73 m2 ) and Cur2 (Cur ≥ 6.2 ml/min/1.73m2 ) groups according to the median of FEua or Cur, respectively. Results: After adjusting for confounding factors, multiple linear regression analysis showed that FEua was positively associated with the mMDP and nMDP, Cur was positively associated with CV of dMSP. Levels of mMDP and nMDP in FEua1 group was lower than that in FEua2 group (both P < 0.05), level of CV of dMSP in Cur2 group were higher than that in Cur1 group (P < 0.01). Conclusions: We demonstrated that there is a positive correlation of FEua with morning and night mean diastolic pressure separately and Cur is positively related to CV of dMSP in CKD population. Monitoring the trend of urinary uric acid, may have a role in the early detection for hypertension or relative risks in the population of CKD.