A Series of Ultra-low Permittivity ALaPO (A = Li, Na, K) Metaphosphate Microwave Dielectric Ceramics for Ultra-wideband Dielectric Resonant Antenna Application.

The employment of ultra-low permittivity materials in the configuration of antennas has been demonstrated to augment the antenna bandwidth and diminish signal delay effectively. This study presents three ultra-low permittivity metaphosphate microwave dielectric ceramics (MWDCs). The ALaPO (A = Li, Na, K) metaphosphate ceramics, which all belong to the monoclinic crystal system, exhibit extremely low permittivity (ε ≈ 5) and excellent quality factor (· > 10,000 GHz) at a low sintering temperature ( < 950 °C).

Defense against oxidative stress in by dark tea.

Dark tea, rich in nutricines including tea polyphenols and free amino acids, is a kind of post-fermented tea. The potential application of nutricines against oxidative damage and senescence, which drives animal health maintenance and disease prevention, has attracted considerable interest. In this study, the effect of dark tea and its effects on longevity and defense against oxidative stress was investigated in the () model.

Sugar-Assisted Kinetic Resolutions in Metal/Chiral Amine Co-Catalyzed α-Allylations and [4+2] Cycloadditions: Highly Enantioselective Synthesis of Sugar and Chromane Derivatives.

Functionalized triose-, furanose and chromane-derivatives were synthesized by the titled reactions. The sugar-assisted kinetic resolution/C-C bond-forming cascade processes generate a functionalized sugar derivative with a quaternary stereocenter in a highly enantioselective fashion (up to >99 % ee) by using a simple combination of metal and chiral amine co-catalysts. Notably, the interplay between the chiral sugar substrate and the chiral amino acid derivative allowed for the construction of a functionalized sugar product with high enantioselectivity (up to 99 %) also when using a combination of racemic amine catalyst (0 % ee) and metal catalyst.

Anterior uterine incarceration complicated by placenta previa and placenta accreta spectrum disorder: a case report.

Background: Uterine incarceration is a rare obstetric complication that is always associated with retroversion and prone to misdiagnosis. Pelvic examination and imaging methods including ultrasound and magnetic resonance imaging (MRI) are used as the primary diagnostic tool. We present an asymptomatic anterior uterine incarceration complicated by placenta previa and placenta accreta spectrum (PAS) disorder, which could be diagnosed during the pregnancy periods, but was first diagnosed during the cesarean section (CS) and got the surgeons into trouble.

Efficient Heterogeneous Copper-Catalyzed Alder-Ene Reaction of Allenynamides to Pyrrolines.

Herein, we describe an efficient nanocopper-catalyzed Alder-ene reaction of allenynamides. The copper nanoparticles were immobilized on amino-functionalized microcrystalline cellulose. A solvent-controlled chemoselectivity of the reaction was observed, leading to the chemodivergent synthesis of pyrrolines (2,5-dihydropyrroles) and pyrroles.

Tuning the Sensitivity and Dynamic Range of Optical Oxygen Sensing Films by Blending Various Polymer Matrices.

In this work, eight different types of optical oxygen sensing films were prepared by impregnating indicator and matrix solution on the surface of a polypropylene microporous filter membrane. The polymer matrix of the sensing films was ethyl cellulose (EC), polymethyl methacrylate (PMMA), and their blends with different mixing ratios. Scanning electron microscopy (SEM), laser confocal microscopy, and fluorescence spectrometer were used to investigate the morphologies and optical properties of the sensing films.

Synergistic Catalysis: Highly Enantioselective Acetyl Aza-arene Addition to Enals.

A novel catalytic enantioselective methodology based on synergistic catalysis for the synthesis of chiral 2-acyl pyridines and pyrazines is reported. The strategy involves the metal-Lewis acid activation of acetyl aza-arenes and the secondary-amine activation of enals. The proposed mechanism is supported by DFT calculations.

Extended reverse dorsal metacarpal artery flap for coverage of finger defects distal to the proximal interphalangeal joint.

Unlabelled: Finger reconstruction distal to the proximal interphalangeal (PIP) joint is a challenging task for hand surgeons. Although extended reverse dorsal metacarpal artery (RDMA) flaps were described for coverage of finger defects, reports on repairs beyond the PIP joint are limited. The occurrence of venous congestion of the flaps and their treatments require further clarification.

[An experimental study on transplantation of frozen canine phalangeal joint allografts incorporated with autogenic bone marrow].

Objective: To investigate the result of the transplantation of frozen canine phalangeal joint allografts perforated and incorporated with autogenic bone marrow.

Methods: A proximal interphalangeal joint defect of 1.5 cm was prepared at bilateral sides of twenty-four adult healthy out-bred dogs.