Hybrid aluminum nitride and silicon devices for integrated photonics.

Aluminum nitride has advantages ranging from a large transparency window to its high thermal and chemical resistance, piezoelectric effect, electro-optic property, and compatibility with the complementary metal-oxide-semiconductor fabrication process. We propose a hybrid aluminum nitride and silicon platform for integrated photonics. Hybrid aluminum nitride-silicon basic photonic devices, including the multimode interferometer, Mach-Zehnder interferometer, and micro-ring resonator, are designed and fabricated. The measured extinction ratio is > 22 dB and the insertion loss is < 1 dB in a wavelength range of 40 nm for the Mach-Zehnder interferometer. The extinction ratio and intrinsic quality factor of the fabricated micro-ring resonator are > 16 dB and 43,300, respectively. The demonstrated hybrid integrated photonic platform is promising for realizing ultralow-power optical switching and electro-optic modulation based on the piezoelectric and electro-optic effects of aluminum nitride thin films.

Preparation and Photodegradation Properties of Carbon-Nanofiber-Based Catalysts.

In this study, an iron oxide/carbon nanofibers (Fe2O3/CNFs) composite was prepared by a combination of electrospinning and hydrothermal methods. The characterization of Fe2O3/CNFs was achieved via scanning electron microscopy (SEM), infrared spectroscopy (IR), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). It is shown that when the hydrothermal reaction time was 180 °C and the reaction time was 1 h, the Fe2O3 nanoparticle size was about 90 nm with uniform distribution. The photodegradation performance applied to decolorize methyl orange (MO) was investigated by forming a heterogeneous Fenton catalytic system with hydrogen peroxide. The reaction conditions for the degradation of MO were optimized with the decolorization rate up to more than 99% within 1 h, which can decompose the dyes in water effectively. The degradation process of MO by Fenton oxidation was analyzed by a UV-visible NIR spectrophotometer, and the reaction mechanism was speculated as well.

Effectiveness and safety of moxibustion for vascular dementia: A systematic review and meta-analysis.

BACKGROUND: Vascular dementia (VD) is the only type of dementia that can be prevented and treated. Compared to conventional treatment methods, moxibustion therapy is more effective for VD. This study evaluated the effectiveness and safety of moxibustion in the treatment of VD through a meta-analysis, to provide a complete overview to the advantages of traditional Chinese medicine and provide guidance for clinical application. METHODS: Clinical trials on the therapeutic effects of moxibustion or moxibustion combined with acupuncture on VD were retrieved from the VIP information database, Wanfang, CNKI, PubMed, EMBase, and other resources. The included studies were conducted from January 2000 to October 2020. Among the retrieved studies, the content met the standards upon being collated and extracted, and RevMan5.3 was used for meta-analysis. RESULTS: Thirteen randomized controlled trials (RCTs) were included with 997 patients. The RevMan bias risk assessment revealed that the quality of the studies was generally low. The meta-analysis showed that compared to conventional treatments, moxibution therapy in terms of effective rate, posttreatment Hasegawa Dementia Scale, Mini-Mental State Examination (MMSE), Activity of Daily Living Scale (ADL), Somatostatin (SS), Arginine Vasopressin (AVP), and Syndrome Differentiation Scale of VD were more favorable, and the difference in efficacy was statistically significant. Furthermore, no adverse events were observed in either group. Sensitivity analysis showed strong homogeneity and stable results, whereas funnel plot analysis revealed no significant publication bias. CONCLUSIONS: Moxibustion is effective and safe in the treatment of VD, but more high-quality evidence from further studies is required to support this.

A Novel Method to Determine the Cause of Left Internal Mammary Artery Instant Non-Patency Based on Transit Time Flow Measurement.

Objective: After coronary artery bypass grafting (CABG) surgery, the main causes of poor instant patency of left internal mammary arteries (LIMAs) are competitive flow and anastomotic stenosis, but how to determine the cause of LIMA non-patency without interfering with the native coronary artery is still a difficult problem to be solved urgently. Methods: In this study, a 0D-3D coupled multiscaled CABG model of anastomotic stenosis and competitive flow was constructed. After calculation, the flow waveform of the LIMA was extracted, and the waveform shape, common clinical parameters (average flow, PI, and DF), and graft flow FFT ratio results (F0/H1 and F0/H2) were analyzed. Results: For LIMA, these three common clinical parameters did not differ significantly between the anastomotic stenosis group and competitive flow group. However, the waveform shape and FFT ratio (especially F0/H2) of the competitive flow group were significantly different from those of the anastomotic stenosis group. When the cause was competitive flow, there was systolic backflow, and F0/H2 was too high (>14.89). When the cause was anastomotic stenosis, the waveform maintained a bimodal state and F0/H2 was in a normal state (about 1.17). Conclusion: When poor instant patency of the LIMA is found after CABG, the causes can be determined by graft flow waveform shape and F0/H2.