Synthesis and Photocatalytic Application of Stable Lead-Free Cs2 AgBiBr6 Perovskite Nanocrystals.

Lead halide perovskite nanocrystals (NCs) have demonstrated great potential as appealing candidates for advanced optoelectronic applications. However, the toxicity of lead and the intrinsic instability toward moisture hinder their mass production and commercialization. Herein, to solve such thorny problems, novel lead-free Cs2 AgBiBr6 double perovskite NCs fabricated via a simple hot-injection method are reported, which exhibit impressive stability in moisture, light, and temperature. Such materials are then applied into photocatalytic CO2 reduction, achieving a total electron consumption of 105 µmol g-1 under AM 1.5G illumination for 6 h. This study offers a reliable avenue for Cs2 AgBiBr6 perovskite nanocrystals preparation, which holds a great potential in the further photochemical applications.

[Discussion on the standard of clinical genetic testing report and the consensus of gene testing industry].

The widespread application of next generation sequencing (NGS) in clinical settings has enabled testing, diagnosis, treatment and prevention of genetic diseases. However, many issues have arisen in the meanwhile. One of the most pressing issues is the lack of standards for reporting genetic test results across different service providers. The First Forum on Standards and Specifications for Clinical Genetic Testing was held to address the issue in Shenzhen, China, on October 28, 2017. Participants, including geneticists, clinicians, and representatives of genetic testing service providers, discussed problems of clinical genetic testing services across in China and shared opinions on principles, challenges, and standards for reporting clinical genetic test results. Here we summarize expert opinions presented at the seminar and report the consensus, which will serve as a basis for the development of standards and guidelines for reporting of clinical genetic testing results, in order to promote the standardization and regulation of genetic testing services in China.

A CsPbBr3 Perovskite Quantum Dot/Graphene Oxide Composite for Photocatalytic CO2 Reduction.

Halide perovskite quantum dots (QDs), primarily regarded as optoelectronic materials for LED and photovoltaic devices, have not been applied for photochemical conversion (e.g., water splitting or CO2 reduction) applications because of their insufficient stability in the presence of moisture or polar solvents. Herein, we report the use of CsPbBr3 QDs as novel photocatalysts to convert CO2 into solar fuels in nonaqueous media. Under AM 1.5G simulated illumination, the CsPbBr3 QDs steadily generated and injected electrons into CO2, catalyzing CO2 reduction at a rate of 23.7 µmol/g h with a selectivity over 99.3%. Additionally, through the construction of a CsPbBr3 QD/graphene oxide (CsPbBr3 QD/GO) composite, the rate of electron consumption increased 25.5% because of improved electron extraction and transport. This study is anticipated to provide new opportunities to utilize halide perovskite QD materials in photocatalytic applications.

ATP selection in a random peptide library consisting of prebiotic amino acids.

Based upon many theoretical findings on protein evolution, we proposed a ligand-selection model for the origin of proteins, in which the most ancient proteins originated from ATP selection in a pool of random peptides. To test this ligand-selection model, we constructed a random peptide library consisting of 15 types of prebiotic amino acids and then used cDNA display to perform six rounds of in vitro selection with ATP. By means of next-generation sequencing, the most prevalent sequence was defined. Biochemical and biophysical characterization of the selected peptide showed that it was stable and foldable and had ATP-hydrolysis activity as well.

Promote or inhibit? Research on the transition of consumer potential purchase intention.

A dramatic shift from offline to online has happened in consumer behavior, leading to enterprises ploughing a large number of digital advertisements to capture consumers' attention online. To evaluate the effectiveness of different online advertising, we explore the dynamic impacts of nine different online channels on the transition of consumers' potential purchase intention and the consumer behavior. We use a continuous-time hidden Markov model (CT-HMM) to capture the transfer path of consumers who are affected by various online channels. Our findings reveal that online advertising has a positive and statistically significant impact on the transition of consumer purchase intention, of which search advertising can significantly increase consumers' propensity to purchase, and its effect on transferring consumers from high to low purchase intention is not very strong in comparison. However, consumers have a very low annoyance threshold to short messaging service (SMS) advertising, and they are easy to get tired of SMS advertising and transfer to low purchase intention. Most firm-initiated advertising is more likely to transfer consumers to a low purchase intention state. Advertisements which can not improve consumer purchase intention very well have fewer stimulating effects on consumers' information collection behavior than other advertisements. Our research contributes to the literature on the effectiveness of online advertising and provide some management insights for enterprises.

[A model for the evaluation of groundwater ecological compensation budget]. / åœ°ä¸‹æ°´ç”Ÿæ€è¡¥å¿æ ‡å‡†æ ¸ç®—æ¨¡åž‹.

Groundwater, one of the important water resources, plays an important role in maintaining sustainable social and economic development. The ecological compensation of groundwater is a beneficial tool for guaranteeing reasonable exploitation and utilization of groundwater resources. However, there is a lack of associated studies, especially compensation budget. We proposed an integrated groundwater compensation standard model, which consisted of four components: base, stimulus and punishment, research and development, and potential risk. The priority level of compensation was estimated by considering regional climate and economic conditions comprehensively. The model was applied to a total of 11 cities in Shanxi Province to calculate the groundwater ecolo-gical compensation standard. The results showed that the base compensation accounted for the largest proportion in the total compensation, with the non-market value contributing more than 60%. Our results indicated that groundwater had a high regulated service value. From 2008 to 2017, the development coefficient of each city had significantly increased, suggesting the improved regional economic level and enhanced compensation capacity. Compensation priority was affected by the non-market value of groundwater and economic level, and obvious difference in the compensation priority existed in all the cities, implying the requirement for the implement of groundwater ecological compensation. Meanwhile, we suggested that groundwater risk compensation system should be improved, special funds should be set up for supporting research projects on groundwater ecological compensation, and long-term effective compensation mechanisms should be established.

Why the c-Fos/c-Jun complex is extremely conserved: An in vitro evolution exploration by combining cDNA display and proximity ligation.

Transcriptional regulation involves a series of sophisticated protein-protein and protein-DNA interactions (PPI and PDI). Some transcriptional complexes, such as c-Fos/c-Jun and their binding DNA fragments, have been conserved over the past one billion years. Considering the thermodynamic principle for transcriptional complex formation, we hypothesized that the c-Fos/c-Jun complex may represent a thermodynamic summit in the evolutionary space. To test this, we invented a new method, termed One-Pot-seq, which combines cDNA display and proximity ligation to analyse PPI/PDI complexes simultaneously. We found that the wild-type c-Fos/c-Jun complex is indeed the most thermodynamically stable relative to various mutants of c-Fos/c-Jun and binding DNA fragments. Our method also provides a universal approach to detect transcriptional complexes and explore transcriptional regulation mechanisms.

In Situ Growth of 120 cm2 CH3 NH3 PbBr3 Perovskite Crystal Film on FTO Glass for Narrowband-Photodetectors.

Organometal trihalide perovskites have been attracting intense attention due to their enthralling optoelectric characteristics. Thus far, most applications focus on polycrystalline perovskite, which however, is overshadowed by single crystal perovskite with superior properties such as low trap density, high mobility, and long carrier diffusion length. In spite of the inherent advantages and significant optoelectronic applications in solar cells and photodetectors, the fabrication of large-area laminar perovskite single crystals is challenging. In this report, an ingenious space-limited inverse temperature crystallization method is first demonstrated to the in situ synthesis of 120 cm2 large-area CH3 NH3 PbBr3 crystal film on fluorine-doped tin oxide (FTO) glass. Such CH3 NH3 PbBr3 perovskite crystal film is successfully applied to narrowband photodetectors, which enables a broad linear response range of 10-4 -102 mW cm-2 , 3 dB cutoff frequency (f 3 dB ) of ≈110 kHz, and high narrow response under low bias -1 V.

A micron-scale laminar MAPbBr3 single crystal for an efficient and stable perovskite solar cell.

Nowadays, obtaining a thin and large-area perovskite single-crystal (SC) is still challenging. Herein, we report a novel strategy to prepare a laminar MAPbBr3 SC with a controllable thickness of 16 µm and a size of 6 × 8 mm. Additionally, the SC solar cell achieves an intriguing efficiency of 7.11% with an impressive stability, maintaining 93% initial PCE after aging for 1000 h.

3,4-Phenylenedioxythiophene (PheDOT) Based Hole-Transporting Materials for Perovskite Solar Cells.

Two new electron-rich molecules based on 3,4-phenylenedioxythiophene (PheDOT) were synthesized and successfully adopted as hole-transporting materials (HTMs) in perovskite solar cells (PSCs). X-ray diffraction, absorption spectra, photoluminescence spectra, electrochemical properties, thermal stabilities, hole mobilities, conductivities, and photovoltaic parameters of PSCs based on these two HTMs were compared with each other. By introducing methoxy substituents into the main skeleton, the energy levels of PheDOT-core HTM were tuned to match with the perovskite, and its hole mobility was also improved (1.33×10(-4)  cm(2) V(-1) s(-1) , being higher than that of spiro-OMeTAD, 2.34×10(-5)  cm(2) V(-1) s(-1)). The PSC based on MeO-PheDOT as HTM exhibits a short-circuit current density (Jsc) of 18.31 mA cm(-2) , an open-circuit potential (Voc ) of 0.914 V, and a fill factor (FF) of 0.636, yielding an encouraging power conversion efficiency (PCE) of 10.64 % under AM 1.5G illumination. These results give some insight into how the molecular structures of HTMs affect their performances and pave the way for developing high-efficiency and low-cost HTMs for PSCs.

3D Cathodes of Cupric Oxide Nanosheets Coated onto Macroporous Antimony-Doped Tin Oxide for Photoelectrochemical Water Splitting.

Cupric oxide (CuO), a narrow-bandgap semiconductor, has a band alignment that makes it an ideal photocathode for the renewable production of solar fuels. However, the photoelectrochemical performance of CuO is limited by its poor conductivity and short electron diffusion lengths. Herein, a three-dimensional (3D) architecture consisting of CuO nanosheets supported onto transparent conducting macroporous antimony-doped tin oxide (mpATO@CuONSs) is designed as an excellent photocathode for promoting the hydrogen evolution reaction (HER). Owing to the 3D structure affording superior light-harvesting characteristics, large contact areas with the electrolyte, and highly conductive pathways for separation and transport of charge carriers, the mpATO@CuONSs photocathode produces an impressively high photocurrent density of -4.6 mA cm-2 at 0 V versus the reversible hydrogen electrode (RHE), which is much higher than that of the CuONSs array onto planar FTO glass (-1.9 mA cm-2 ).

Achieving Highly Efficient Photoelectrochemical Water Oxidation with a TiCl4 Treated 3D Antimony-Doped SnO2 Macropore/Branched α-Fe2O3 Nanorod Heterojunction Photoanode.

Utilizing photoelectrochemical (PEC) cells to directly collecting solar energy into chemical fuels (e.g., H2 via water splitting) is a promising way to tackle the energy challenge. α-Fe2O3 has emerged as a desirable photoanode material in a PEC cell due to its wide spectrum absorption range, chemical stability, and earth abundant component. However, the short excited state lifetime, poor minority charge carrier mobility, and long light penetration depth hamper its application. Recently, the elegantly designed hierarchical macroporous composite nanomaterial has emerged as a strong candidate for photoelectrical applications. Here, a novel 3D antimony-doped SnO2 (ATO) macroporous structure is demonstrated as a transparent conducting scaffold to load 1D hematite nanorod to form a composite material for efficient PEC water splitting. An enormous enhancement in PEC performance is found in the 3D electrode compared to the controlled planar one, due to the outstanding light harvesting and charge transport. A facile and simple TiCl4 treatment further introduces the Ti doping into the hematite while simultaneously forming a passivation layer to eliminate adverse reactions. The results indicate that the structural design and nanoengineering are an effective strategy to boost the PEC performance in order to bring more potential devices into practical use.

Aberrantly expressed miR-582-3p maintains lung cancer stem cell-like traits by activating Wnt/ß-catenin signalling.

Cancer stem cells (CSCs) are involved in tumorigenesis, tumour recurrence and therapy resistance and Wnt signalling is essential for the development of the biological traits of CSCs. In non-small cell lung carcinoma (NSCLC), unlike in colon cancer, mutations in ß-catenin and APC genes are uncommon; thus, the mechanism underlying the constitutive activation of Wnt signalling in NSCLC remains unclear. Here we report that miR-582-3p expression correlates with the overall- and recurrence-free-survival of NSCLC patients, and miR-582-3p has an activating effect on Wnt/ß-catenin signalling. miR-582-3p overexpression simultaneously targets multiple negative regulators of the Wnt/ß-catenin pathway, namely, AXIN2, DKK3 and SFRP1. Consequently, miR-582-3p promotes CSC traits of NSCLC cells in vitro and tumorigenesis and tumour recurrence in vivo. Antagonizing miR-582-3p potently inhibits tumour initiation and progression in xenografted animal models. These findings suggest that miR-582-3p mediates the constitutive activation of Wnt/ß-catenin signalling, likely serving as a potential therapeutic target for NSCLC.

miR-205 targets PTEN and PHLPP2 to augment AKT signaling and drive malignant phenotypes in non-small cell lung cancer.

AKT signaling is constitutively activated in various cancers, due in large part to loss-of-function in the PTEN and PHLPP phosphatases that act as tumor suppressor genes. However, AKT signaling is activated widely in non-small cell lung cancers (NSCLC) where genetic alterations in PTEN or PHLPP genes are rare, suggesting an undefined mechanism(s) for their suppression. In this study, we report upregulation of the oncomir microRNA (miR)-205 in multiple subtypes of NSCLC, which directly represses PTEN and PHLPP2 expression and activates both the AKT/FOXO3a and AKT/mTOR signaling pathways. miR-205 overexpression in NSCLC cells accelerated tumor cell proliferation and promoted blood vessel formation in vitro and in vivo. Conversely, RNA interference-mediated silencing of endogenous miR-205 abrogated these effects. The malignant properties induced by miR-205 in NSCLC cells were reversed by AKT inhibitors, FOXO3a overexpression, rapamycin treatment, or restoring PHLPP2 or PTEN expression. Mechanistic investigations revealed that miR-205 overexpression was a result of NF-κB-mediated transactivation of the miR-205 gene. Taken together, our results define a major epigenetic mechanism for suppression of PTEN and PHLPP2 in NSCLC, identifying a pivotal role for miR-205 in development and progression of this widespread disease.

MicroRNA-30e* promotes human glioma cell invasiveness in an orthotopic xenotransplantation model by disrupting the NF-κB/IκBα negative feedback loop.

Constitutive activation of NF-κB is a frequent event in human cancers, playing important roles in cancer development and progression. In nontransformed cells, NF-κB activation is tightly controlled by IκBs. IκBs bind NF-κB in the cytoplasm, preventing it from translocating to the nucleus to modulate gene expression. Stimuli that activate NF-κB signaling trigger IκB degradation, enabling nuclear translocation of NF-κB. Among the genes regulated by NF-κB are those encoding the IκBs, providing a negative feedback loop that limits NF-κB activity. How transformed cells override this NF-κB/IκB negative feedback loop remains unclear. Here, we report in human glioma cell lines that microRNA-30e* (miR-30e*) directly targets the IκBα 3ι-UTR and suppresses IκBα expression. Overexpression of miR-30e* in human glioma cell lines led to hyperactivation of NF-κB and enhanced expression of NF-κB-regulated genes, which promoted glioma cell invasiveness in in vitro assays and in an orthotopic xenotransplantation model. These effects of miR-30e* were shown to be clinically relevant, as miR-30e* was found to be upregulated in primary human glioma cells and correlated with malignant progression and poor survival. Hence, miR-30e* provides an epigenetic mechanism that disrupts the NF-κB/IκBα loop and may represent a new therapeutic target and prognostic marker.

Astrocyte elevated gene-1 upregulates matrix metalloproteinase-9 and induces human glioma invasion.

The poor prognosis of malignant gliomas is largely attributed to their highly invasive nature. The molecular mechanism underlying the invasiveness of glioma cells, however, remains to be elucidated. The present study found that astrocyte elevated gene-1 (AEG-1) was upregulated in human glioma cell lines and glioma tissues compared with normal astrocytes and brain tissues. AEG-1 was found to be upregulated in 265 of 296 (89.5%) glioma sections, and the AEG-1 expression level significantly correlated with clinicopathologic stages of gliomas. Ectopic expression or short hairpin RNA silencing of AEG-1 significantly enhanced or inhibited, respectively, the invasive ability of glioma cells. At the molecular level, we showed that upregulated AEG-1 in glioma cells interacted with matrix metalloproteinase-9 (MMP-9) promoter and transactivated MMP-9 expression, whereas knockdown of AEG-1 expression reduced the level of MMP-9. Two regions in MMP-9 promoter were found to be involved in the interaction with AEG-1. Suppression of endogenous MMP-9 abrogated the effects of AEG-1 on invasiveness. Consistent with these observations, immunostaining analysis revealed a significant correlation between the expressions of AEG-1 and MMP-9 in a cohort of clinical glioma samples. Moreover, intracranial xenografts of glioma cells engineered to express AEG-1 were highly invasive compared with the parental cells and expressed high level of MMP-9. Collectively, these findings provide evidence that AEG-1 contributes to glioma progression by enhancing MMP-9 transcription and, hence, tumor cell invasiveness, and underscore the importance of AEG-1 in glioma development and progression.