Featuring size-tunable electrical and optical properties, semiconductor quantum dots (QDs) are appealing intensive interests in developing ingenious luminescent materials for chemosensory and ...biological applications. The surface modification of QDs with functional ligands not only fine-tunes the physiochemical properties and fluorescence emission behaviors, but also induces the designated interplay between analytes and probes for special determination. In this review, the fundamental principles guiding the rational design of high-efficiency luminescent sensors with surface engineering are overviewed. The state-of-the-art applications of QDs-based probes are highlighted for the sensing of molecular substrates and ionic species as well as various biological applications, with the inherent recognition mechanisms elaborated for representative cases. The challenge and future research direction in this emerging and promising research field are also discussed.
The critical review on the recent development of novel narrow bandgap polymers for high-efficiency polymer solar cells concentrates on (i) the structural design of narrow bandgap polymers, which ...occupy a central place in recent advances in high-efficiency polymer solar cells, (ii) the intrinsic physics and chemistry of special properties, such as absorption, bandgap and energy levels, and (iii) the correlation of polymer structure and device fabrication with their photovoltaic performances. The statistical summaries of their device parameters are also discussed. The description of these structure–property correlations may guide the rational design of polymer structures and the reasonable evaluation of their photovoltaic performance.
Dapagliflozin, a highly selective inhibitor of the renal sodium-glucose cotransporter-2, increases urinary excretion of glucose and lowers plasma glucose levels in an insulin-independent manner. We ...evaluated the efficacy and safety of dapagliflozin in treatment-naive patients with type 2 diabetes.
This was a 24-week parallel-group, double-blind, placebo-controlled phase 3 trial. Patients with A1C 7.0-10% (n = 485) were randomly assigned to one of seven arms to receive once-daily placebo or 2.5, 5, or 10 mg dapagliflozin once daily in the morning (main cohort) or evening (exploratory cohort). Patients with A1C 10.1-12% (high-A1C exploratory cohort; n = 73) were randomly assigned 1:1 to receive blinded treatment with a morning dose of 5 or 10 mg/day dapagliflozin. The primary end point was change from baseline in A1C in the main cohort, statistically tested using an ANCOVA.
In the main cohort, mean A1C changes from baseline at week 24 were -0.23% with placebo and -0.58, -0.77 (P = 0.0005 vs. placebo), and -0.89% (P < 0.0001 vs. placebo) with 2.5, 5, and 10 mg dapagliflozin, respectively. Signs, symptoms, and other reports suggestive of urinary tract infections and genital infection were more frequently noted in the dapagliflozin arms. There were no major episodes of hypoglycemia. Data from exploratory cohorts were consistent with these results.
Dapagliflozin lowered hyperglycemia in treatment-naive patients with newly diagnosed type 2 diabetes. The near absence of hypoglycemia and an insulin-independent mechanism of action make dapagliflozin a unique addition to existing treatment options for type 2 diabetes.
•The development of cationic cyclodextrins as mobile phases for chiral separation.•The development of structurally defined cationic cyclodextrins for chiral separation.•We summarize approaches to ...revealing the chiral recognition mechanism.•Exploring cationic cyclodextrin-based stationary phases for chiral separation.
Cationic cyclodextrins (CDs) have attracted considerable interest in the field of chiral separation. Targeting effective modulation of the interactions between chiral selectors and analytes for enhanced chiral recognition, a growing library of positively charged CDs has been developed for different analytical techniques. This review updates the research endeavors of synthetic and analytical chemists in evaluating enantioselectivity of cationic CDs using different analytical methods and the study of the chiral recognition mechanism. We pay specific attention to the structurally defined cationic CDs, which have been explored for versatile chiral separation in a variety of techniques when subject to further modification.
A new electron‐rich central building block, 5,5,12,12‐tetrakis(4‐hexylphenyl)‐indacenobis‐(dithieno3,2‐b:2′,3′‐dpyrrol) (INP), and two derivative nonfullerene acceptors (INPIC and INPIC‐4F) are ...designed and synthesized. The two molecules reveal broad (600–900 nm) and strong absorption due to the satisfactory electron‐donating ability of INP. Compared with its counterpart INPIC, fluorinated nonfullerene acceptor INPIC‐4F exhibits a stronger near‐infrared absorption with a narrower optical bandgap of 1.39 eV, an improved crystallinity with higher electron mobility, and down‐shifted highest occupied molecular orbital and lowest unoccupied molecular orbital energy levels. Organic solar cells (OSCs) based on INPIC‐4F exhibit a high power conversion efficiency (PCE) of 13.13% and a relatively low energy loss of 0.54 eV, which is among the highest efficiencies reported for binary OSCs in the literature. The results demonstrate the great potential of the new INP as an electron‐donating building block for constructing high‐performance nonfullerene acceptors for OSCs.
Nonfullerene acceptors (NFAs) featuring indacenobis‐(dithieno3,2‐b:2′,3′‐dpyrrol) as an electron‐rich central building block are designed. The NFAs extend absorption to 900 nm with an optical bandgap of 1.39 eV. Organic solar cells (OSCs), by blending with PBDB‐T as polymer donor, contribute a power conversion efficiency of 13.13%, which is among the highest reported for binary OSCs in the literature.
Ga
O
-based solar blind avalanche photodetectors exhibit low voltage operation, optical filter-free and monolithic integration of photodetector arrays, and therefore they are promising to be an ...alternative to the bulky and fragile photomultiplier tubes for weak signal detection in deep-ultraviolet region. Here, by deliberate lattice and band engineering, we construct an n-Barrier-n unipolar barrier avalanche photodetector consisting of β-Ga
O
/MgO/Nb:SrTiO
heterostructure, in which the enlarged conduction band offsets fortify the reverse breakdown and suppress the dark current while the negligible valance band offsets faciliate minority carrier flow across the heterojunction. The developed devices exhibit record-high avalanche gain up to 5.9 × 10
and detectivity of 2.33 × 10
Jones among the reported wafer-scale grown Ga
O
-based photodetectors, which are even comparable to the commercial photomultiplier tubes. These findings provide insights into precise manipulation of band alignment in avalanche photodetectors, and also offer exciting opportunities for further developing high-performance Ga
O
-based electronics and optoelectronics.
•The preparation of cationic cyclodextrin (CD) clicked chiral stationary phase (CSP).•The enantioseparation 21 recemates with the CD clicked CSP in both reversed phase and normal-phase ...high-performance liquid chromatography.•The fine-tuned enantioselectivity of CD CSP with the polarity of mobile phase using organic modifier.•The excellent chiral resolutions readily achieved with CD clicked CSP.
In this work, a novel cationic cyclodextrin (CD) chiral stationary phase (CSPs) has been developed by clicking 6A-azido-6C-(3-methoxylpropyl)-1- ammonium-heptakis2,3-di-O-(3-chloro-4-methylphenylcarbamate)-6B,6D,6E,6F,6G-pentakis-O-per(3-chloro-4-methylphenylcarbamate)-β-CD chloride onto alkynyl silica support. The enantioselectivies of the as-obtained novel CSP were evaluated using 21 model racemates including flavonoids, aromatic alcohols, acidic drugs, β-blocker and amino acids. Good enantioseparations were achieved in polar-organic phase high performance liquid chromatography (HPLC), with the highest resolution of 8.07 observed for 7-methoxyflavanone. The enantioseparations in normal-phase HPLC were fine-tuned with the polarity of the mobile phase with different alcohols as organic modifiers. Improved chiral resolutions of analytes but longer retention were observed in mobile phases with decreased polarity. On comparison with previously reported clicked CD CSP, the cationic CD clicked CSP exhibited better enenatioseparations for selected racemates even in normal-phase HPLC. The results indicate that 3-methoxypropylammonium and phenylcarbamoylated moieties of the cationic CSP may provide intermolecular interactions such as hydrogen bonding, π–π conjugation and dipole–dipole besides inclusion complexation to drive the enantioseparation.
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•Solar-blind ultraviolet photodetectors based on high quality epitaxial β-Ga2O3 films were fabricated by MOCVD.•In-depth analysis of illumination and bias impact on the photoresponse ...properties was performed.•The photoresponse speed can be accelerated up to two orders by varying the illumination and bias voltage.•The light controllable trap/detrap processes as well as electric field accelerated carrier transport was systematically studied.
Ga2O3-based solar-blind ultraviolet photodetectors (PDs) have stimulated extensive attention for covering both civilian and military applications. During the past decade, Ga2O3-based solar-blind PDs have made a great progress in key metrics such as responsivity, detectivity and gain. However, they still suffer from relatively slow response time, from milliseconds to seconds. The trapping states at the surface/interface are believed to contribute to the low response speed. Besides the intrinsic factors, external factors including the illumination and bias voltage also have an important influence on the photoresponse speed. However, there is no in-depth analysis of illumination and bias impact on the photoresponse properties. Herein, we present an experimental investigation on the illumination intensity and bias voltage modulating response speed in a typical Ga2O3-based photoconductive PD. The photoresponse time can be accelerated up to two orders by varying the illumination and bias. The superior photoresponse capabilities of the Ga2O3-based PDs can be ascribed to the light controllable trap/de-trap processes as well as electric field accelerated carrier transport. The study offers clear images of the charge diffusion and drift process in the photodetector upon external stimuli, which will aid to optimize the performance of Ga2O3-based PDs.
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![Dithieno[3,2‐b:2′,3′‐d]pyrr...](http://api.summon.serialssolutions.com/2.0.0/image/issn/XR4PS5YY4K/0935-9648/small "Dithieno[3,2‐b:2′,3′‐d]pyrrol Fused Nonfullerene Acceptors Enabling Over 13% Efficiency for Organic Solar Cells")
