This work presents the generation of an Airy beam by a leaky-wave structure (LWS) designed from a substrate-integrated waveguide (SIW) with dimension-varying slots. The Airy beam is radiated by judiciously designing the length of the slots to modulate the phase distribution. Compared to Airy beams generated by phased array antennas or metasurfaces, no complex feeding network associated with phase shifters and no space-wave illumination is required, thus allowing one to reach a low-profile structure.
View Article and Find Full Text PDFMetasurfaces have shown unparalleled controllability of electromagnetic (EM) waves. However, most of the metasurfaces need external spatial feeding sources, which renders practical implementation quite challenging. Here, a low-profile programmable metasurface with 0.
View Article and Find Full Text PDFAim: To determine the 15-year outcomes of laser dacryoplasty (LDP) in patients with lacrimal duct obstruction; and to evaluate LDP combined with intubation using a new silicone tube to treat complicated cases.
Methods: Patients with lacrimal duct obstruction and treated with LDP between April 2000 and April 2005 were investigated retrospectively. Totally 116 eyes with completed 15-year follow-up records were included in this study.
Ethnopharmacological Relevance: Diarrhea is a frequently encountered gastrointestinal complication in clinical practice, and E. coli is one of the main causative agents. Although Qingjie decoction (QJD) has been shown to be highly effective in treating diarrhea by eliminating heat-toxin, the underlying molecular mechanisms and pathways of QJD remain unclear.
View Article and Find Full Text PDFPortulaca oleracea L. (PO) is an edible and medicinal plant used for treating gastrointestinal diseases. However, the effects of PO on ulcerative colitis (UC) and underlying mechanisms remain unclear.
View Article and Find Full Text PDFThe design of efficient and sustainable Pt-based catalysts is the key to the development of direct methanol fuel cells. However, most Pt-based catalysts still exhibit disadvantages including unsatisfied catalytic activity and serious CO poisoning in the methanol oxidation reaction (MOR). Herein, highly porous PtAg nanoflowers (NFs) with rich defects are synthesized by using liquid reduction combining chemical etching.
View Article and Find Full Text PDFWe propose a new concept exploiting thermally activated delayed fluorescence (TADF) molecules as photosensitizers, storage units and signal transducers to harness solar thermal energy. Molecular composites based on the TADF core phenoxazine-triphenyltriazine (PXZ-TRZ) anchored with norbornadiene (NBD) were synthesized, yielding compounds PZDN and PZTN with two and four NBD units, respectively. Upon visible-light excitation, energy transfer to the triplet state of NBD occurred, followed by NBD → quadricyclane (QC) conversion, which can be monitored by changes in steady-state or time-resolved spectra.
View Article and Find Full Text PDFThe removal of Cr(VI) has attracted extensive attention since it causes serious harm to public health. Herein, we report a two-step method to synthesize N-doped MoS nanoflowers (NFs) with controllable sizes, which are first utilized for Cr(VI) removal and display outstanding removal performance. The N-MoS NFs with an average size of 40 nm (N-MoS NFs-40 nm) can rapidly remove Cr(VI) in 15 min under optimal conditions.
View Article and Find Full Text PDFThe diagnostic efficiency of the quantitative fecal immunochemical test (qFIT) has large variations in colorectal cancer (CRC) screening. We aimed to explore whether the practical sample collection operant training could improve the diagnostic accuracy of the qFIT in CRC screening. Moderate-/high-risk individuals aged 50-75 years old were invited to participate in a prospective observational study between July 2020 and March 2021.
View Article and Find Full Text PDFBackground: Shaoyao decoction (SYD), a traditional Chinese medicine prescription that originated in the Jin-Yuan Dynasty, has shown effects in treating ulcerative colitis. However, the underlying mechanism is unclear. We combined network pharmacology with molecular biology technology to detect the mechanism underlying the effect of SYD on ulcerative colitis.
View Article and Find Full Text PDFWe report here, for the first time, the experimental observation on the excited-state intramolecular proton transfer (ESIPT) reaction of the thiol proton in room-temperature solution. This phenomenon is demonstrated by a derivative of 3-thiolflavone (), namely, 2-(4-(diethylamino)phenyl)-3-mercapto-4-chromen-4-one (), which possesses an -S-H···O═ intramolecular H-bond (denoted by the dashed line) and has an S absorption at 383 nm. Upon photoexcitation, exhibits a distinctly red emission maximized at 710 nm in cyclohexane with an anomalously large Stokes shift of 12 230 cm.
View Article and Find Full Text PDFThe fast and sensitive detection of methanol gas using cost-effective sensors in the industry is a significant issue to be addressed. Herein, a polyindole (PIn)-deposited substrate integrated waveguide (SIW) has been introduced to perform quantitative and qualitative methanol gas sensing with quick response and recovery time at room temperature. First, PIn is synthesized and deposited in the microwell etched at the intensified electric field region of the microwave-based cavity resonator, which gives a sensing response through variation of PIn's high-frequency conductivity and dielectric property caused by the adsorption and desorption of methanol gas.
View Article and Find Full Text PDFWith the aim of generalizing the structure-properties relationship of bending heterocyclic molecules that undergo prominent photoinduced structural planarization (PISP), a series of new dihydrodibenzo[ac]phenazine derivatives in which one nitrogen atom is replaced by oxygen (PNO), sulfur (PNS), selenium (PNSe), or dimethylmethanediyl (PNC) was strategically designed and synthesized. Compounds PNO, PNS, and PNSe have significantly nonplanar geometries in the ground state, which undergo PISP to give a planarlike conformer and hence a large emission Stokes shift. A combination of femtosecond early relaxation dynamics and computational approaches established an R*→I* (intermediate)→P* sequential kinetic pattern for PNS and PNSe, whereas PNO undergoes R*→P* one-step kinetics.
View Article and Find Full Text PDFIn this study, electromagnetically induced transparency (EIT) effect in all-dielectric metamaterial for dual-band linear-to-circular (LTC) polarization conversion is demonstrated numerically and experimentally. The unit cell is composed of three ceramic blocks with different sizes. Due to the anisotropy of metamaterial and polarization dependence of subsequent EIT effects, transmission spectra for x- and y-polarized incident waves are realized to induce LTC polarization conversion.
View Article and Find Full Text PDFZhongguo Shi Yan Xue Ye Xue Za Zhi
June 2018
This paper introduces the concept of electromagnetically induced transparency (EIT) into the permittivity extraction of an anisotropic material-nematic liquid crystal (NLC). A novel two-step strategy is presented to extract the complex permittivity of the NLC at the THz band, which evaluates the relative permittivity tensor from the resonant frequencies and then determines the loss tangent from the quality factor Q of the EIT sensor. The proposed method features high accuracy due to the sharp resonance of the EIT sensor and also high robustness to the thickness of the NLC layer because only amplitude rather than phase information of the transmission coefficients is required.
View Article and Find Full Text PDFSearching for eight-membered ring π-conjugated hydrogen bonding (8-MR H-bonding) systems with excited-state intramolecular proton transfer (ESIPT) property is seminal and synthetically challenging. In this work, a series of π-conjugated molecules (8-HB-1, 8-HB-L1 and 8-HB-2) potentially possessing 8-MR H-bonding are strategically designed, synthesized and characterized. The configurations of these three potential molecules are checked by their X-ray structures, among which 8-HB-L1 (a structurally locked 8-HB-1 core chromophore) is proved to be an 8-MR H-bonding system, whereas 8-HB-1 and 8-HB-2 are too sterically hindered to form the 8-MR intramolecular H-bond.
View Article and Find Full Text PDFNan Fang Yi Ke Da Xue Xue Bao
March 2017
Objective: To study the clinical implications of death-associated protein kinase (DAPK) promoter methylation and DAPK gene expression in untreated patients with acute leukemia.
Methods: Methylation-specific PCR and RT-PCR were employed to detect the DAPK gene methylation and mRNA expression in the bone marrow of 60 patients with acute myeloid leukemia (AML), 55 patients with acute lymphocytic leukemia (ALL), and 17 normal subjects.
Results: The positivity rate of DAPK methylation was significantly higher in ALL patients (29.