Superior photo-carrier diffusion dynamics in organic-inorganic hybrid perovskites revealed by spatiotemporal conductivity imaging

The outstanding performance of organic-inorganic metal trihalide solar cells benefits from the exceptional photo-physical properties of both electrons and holes in the material. Here, we directly probe the free-carrier dynamics in Cs-doped FAPbI3 thin films by spatiotemporal photoconductivity imaging. Using charge transport layers to selectively quench one type of carriers, we show that the two relaxation times on the order of 1 μs and 10 μs correspond to the lifetimes of electrons and holes in FACsPbI3, respectively. Strikingly, the diffusion map- ping indicates that the difference in electron/hole lifetimes is largely compensated by their disparate mobility. Consequently, the long diffusion lengths (3~5 μm) of both carriers are comparable to each other, a feature closely related to the unique charge trapping and de- trapping processes in hybrid trihalide perovskites. Our results unveil the origin of superior diffusion dynamics in this material, crucially important for solar-cell applications.The research at UT-Austin was primarily supported by the NSF through the Center for Dynamics and Control of Materials, an NSF Materials Research Science and Engineering Center (MRSEC) under Cooperative Agreement DMR-1720595. The authors also acknowledge the use of facilities and instrumentation supported by the NSF MRSEC. K.L. and X.M. acknowledge the support from Welch Foundation Grant F-1814. X. Li acknowledges the support from Welch Foundation Grant F-1662. The tip-scan iMIM setup was supported by the US Army Research Laboratory and the US Army Research Office under Grants W911NF-16-1-0276 and W911NF-17-1-0190. The work at NREL was supported by the US DOE under Contract No. DE-AC36-08GO28308 with Alliance for Sustainable Energy, Limited Liability Company (LLC), the Manager and Operator of the National Renewable Energy Laboratory. K.Z., J.H., X.C., X.W., and Y.Y. acknowledge the support on charge carrier dynamics study from the Center for Hybrid Organic-Inorganic Semiconductors for Energy (CHOISE), an Energy Frontier Research Center funded by the Office of Basic Energy Sciences, Office of Science within the US DOE. F.Z. acknowledges the support on devices fabrication and characterizations from the De-Risking Halide PSCs program of the National Center for Photovoltaics, funded by the US DOE, Office of Energy Efficiency and Renewable Energy, Solar Energy Technologies Office.Center for Dynamics and Control of Material

A simple but actionable metric for assessing inequity in resident greenspace exposure

An increasing number of studies aim to improve and perfect the evaluation system for assessing greenspace exposure, yet it may also become more difficult to apply the evaluation index to landscape planning. Here we propose a simple but actionable index system – Greenspace Exposure Inequity index (GEII), for assessing the inequity of residents' greenspace exposure. GEII includes quantity-based availability, distance-based accessibility, and inequity-based Gini index for assessing the difference in greenspace exposure pattern. Then we selected Shanghai as a case to test the feasibility of GEII, analyzing the spatiotemporal evolution of greenspace exposure patterns, and further demonstrating the operability of the index. (1) Availability inequity for 2012, 2015, 2018, and 2021 was 0.603, 0.512, 0.514, and 0.489. The Gini index was between 0.4 and 0.6, and presented a downward trend. (2) Accessibility inequity for 2012, 2015, 2018, and 2021 was 0.372, 0.368, 0.364, and 0.344. It can be clearly seen that it has changed less over ten years, but overall equality has been rising. (3) Using GEII to calculate the inequity of Shanghai, the Gini index for 2012, 2015, 2018, and 2021 was 0.392, 0.378, 0.373, and 0.357. The inequity of greenspace exposure assessed by GEII is gradually decreasing similarly, which illustrates the positive impact of urban greening policies. The GEII has three highlights: serviceability, human-oriented, and expandability. GEII abandons the complex computational evaluation procedures of numerous indicators and bridges the gap between theoretical research on inequity and practical planning, so GEII is of great value for alleviating the uneven exposure of residents' greenspace and scientifically optimizing landscape planning

Study on the Comprehensive Utilization of Bitter Almond Shell

A comprehensive process was developed to make full use of the solid and liquid products during the production of activated carbon. Almond shell waste was modified with phosphoric acid and thermally treated to give activated carbon. Wood vinegar was generated and collected within the temperature range of 90 to 500 °C, and the maximum amount of the wood vinegar was in the range of 170 to 370 °C, which also gave the strongest anti-pathogens activities with the lowest pH and the highest organic acid content. The remaining residue after wood vinegar generation was further calcined in inert atmosphere to obtain high surface area activated carbon. The pre-treatment of almond shell with H3PO4 leads to the higher surface area, but H3PO4 solution with concentration more than 40% does not increase the surface area further. The impregnation of H3PO4 helps the formation of pores in the almond shell during the calcination, and gives higher iodine number and methylene blue sorption capacity of the resultant activated carbon materials

Diagnostic and Prognostic Values of MANF Expression in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors, and its prognosis is still poor. Mesencephalic astrocyte-derived neurotrophic factor (MANF) plays a key role in endoplasmic reticulum stress. ER stress plays a key role in HCC carcinogenesis. To confirm the clinical and prognostic value of MANF in HCC, we investigated the expression level of MANF in HCC as recorded in databases, and the results were verified by experiment. Survival analysis was probed by the Kaplan–Meier method. Cox regression models were used to ascertain the prognostic value of MANF in HCC tissue microarray. The diagnostic value of MANF in HCC was evaluated by receiver operating characteristic curve analysis. Potential correlation between MANF and selected genes was also analyzed. Results showed that MANF was overexpressed in HCC. Patients with high MANF expression levels had a worse prognosis and higher risk of tumor recurrence. Furthermore, the expression level of MANF had good diagnostic power. Correlation analysis revealed potential regulatory networks of MANF in HCC, laying a foundation for further study of the role of MANF in tumorigenesis. In conclusion, MANF was overexpressed in HCC and related to the occurrence and development of HCC. It is a potential diagnostic and prognostic indicator of HCC

Exposure Ecology Drives a Unified Understanding of the Nexus of (Urban) Natural Ecosystem, Ecological Exposure, and Health

The intersection of ecology and exposure science with health concerns has led to a gradual infiltration of these disciplines. Exposure to (urban) natural ecosystems, defined as ecological exposure, has proven to be substantially beneficial to health, providing more effective and preventive measures than dealing with downstream consequences of the disease. Besides, the eco-environment & health field have shifted its paradigm from focusing on negative environmental exposure to exploring the positive health benefits of ecological exposure. However, a unified framework that integrates the nexus of natural ecosystem, ecological exposure, and health is still lacking. To address these challenges, here, we propose a new framework (discipline), exposure ecology (EE), and reviewed relevant studies. We suggest that the domain and scope of EE include subject-reality, object-reality, subject-virtual, and object-virtual dimensions and that all previous studies can be covered within this coordinate frame. We analyze the trends and shortcomings of each domain and explain the pathways of ecological exposure to health, including reduction, restoration, promotion capacity, and potential harm. Furthermore, we discuss the theoretical basis for the formation of the theoretical framework of EE, as well as the EE-derived hypotheses, implications, and connections to other related fields. In short, the EE-driven holistic critical review enhances our understanding of this frontier topic substantially, and it can serve as a unified framework for understanding the nexus of natural ecosystems, ecological exposure, and health and realizing the Sustainable Development Goals (SDGs)

Efficacy of COVID-19 vaccines in inflammatory bowel disease patients receiving anti-TNF therapy: A systematic review and meta-analysis

Background and objectives: There are concerns about the serological responses to Coronavirus disease 2019 (COVID-19) vaccines in inflammatory bowel disease (IBD) patients, particularly those receiving anti-TNF therapy. This study aimed to systematically evaluate the efficacy of COVID-19 vaccines in IBD patients receiving anti-TNF therapy. Methods: Electronic databases were searched to identify relevant studies. We calculated pooled seroconversion rate after COVID-19 vaccination and subgroup analysis for vaccine types and different treatments were performed. Additionally, we estimated pooled rate of T cell response, neutralization response, and breakthrough infections in this population. Results: 32 studies were included in the meta-analysis. IBD patients receiving anti-TNF therapy had relatively high overall seroconversion rate after complete vaccination, with no statistical difference in antibody responses associated with different drug treatments. The pooled positivity rate of T cell response was 0.85 in IBD patients receiving anti-TNF therapy. Compared with healthy controls, the positivity of neutralization assays was significantly lower in IBD patients receiving anti-TNF therapy. The pooled rate of breakthrough infections in IBD patients receiving anti-TNF therapy was 0.04. Conclusions: COVID-19 vaccines have shown good efficacy in IBD patients receiving anti-TNF therapy. However, IBD patients receiving anti-TNF have a relatively high rate of breakthrough infections and a low level of neutralization response

PEGylated 2D-nanomaterials alleviate Parkinson's disease by shielding PIP2 lipids to inhibit IP3 second messenger signaling

Researches on nano-bio interfaces have revealed that two-dimensional (2D) nanomaterials can form functionally impactful architectures upon interaction with biological membranes. These biological impacts may drive various changes of membrane phospholipids, raising the possibility of alleviating neurodegenerative disorders by specifically altering metabolism of membrane phospholipids. Here, we demonstrate that PEGylated 2D nanomaterials including graphene oxide and poly -L-lactic acid sheets (denoted as P-sheet) alleviate behavioral and neuronal degeneration of Parkinson's disease (PD). Upon this finding, we experimentally identify enrichment for the phosphatidylinositol-4,5-bisphosphate (PIP2) lipid interacting with P-sheet and reveal the underlying mechanism by molecular dynamics simulations: a flip-flop orientation shift of PIP2 lipids within the membrane restricts the hydrolysis site, preventing cleavage-mediated inositol 1,4,5-trisphosphate. As a result, Ca2+-related endoplasmic reticulum stress can be reduced to protect the neurons of PD mice. These results together support P-sheet nanomaterials as a new type of drug-free agent for selective modulation of neurodegenerative-disorder-associated membrane-lipid dysregulation and potential PD therapy. (C) 2022 Elsevier Ltd. All rights reserved

PEGylated 2D-nanomaterials alleviate Parkinson's disease by shielding PIP2 lipids to inhibit IP3 second messenger signaling

Researches on nano-bio interfaces have revealed that two-dimensional (2D) nanomaterials can form functionally impactful architectures upon interaction with biological membranes. These biological impacts may drive various changes of membrane phospholipids, raising the possibility of alleviating neurodegenerative disorders by specifically altering metabolism of membrane phospholipids. Here, we demonstrate that PEGylated 2D nanomaterials including graphene oxide and poly -L-lactic acid sheets (denoted as P-sheet) alleviate behavioral and neuronal degeneration of Parkinson's disease (PD). Upon this finding, we experimentally identify enrichment for the phosphatidylinositol-4,5-bisphosphate (PIP2) lipid interacting with P-sheet and reveal the underlying mechanism by molecular dynamics simulations: a flip-flop orientation shift of PIP2 lipids within the membrane restricts the hydrolysis site, preventing cleavage-mediated inositol 1,4,5-trisphosphate. As a result, Ca2+-related endoplasmic reticulum stress can be reduced to protect the neurons of PD mice. These results together support P-sheet nanomaterials as a new type of drug-free agent for selective modulation of neurodegenerative-disorder-associated membrane-lipid dysregulation and potential PD therapy. (C) 2022 Elsevier Ltd. All rights reserved