Wuhan University

About: Wuhan University is a education organization based out in Wuhan, China. It is known for research contribution in the topics: Population & Feature extraction. The organization has 92849 authors who have published 92882 publications receiving 1691049 citations. The organization is also known as: WHU & Wuhan College.

Negative refraction and focusing of ultrasound in two-dimensional phononic crystals

Abstract: We present experimental demonstrations of negative refraction and focusing of ultrasonic waves in two-dimensional phononic crystals made of stainless steel rods assembled in a triangular lattice and immersed in a liquid. Negative refraction is achieved for the range of frequencies in the second band, where the directions of the wave vector and group velocity are antiparallel to each other due to circular equifrequency contours. Negative refraction is unambiguously observed using a prism-shaped crystal. By exploiting the circular equifrequency contours in the second band, focusing of the ultrasonic field emitted by a pointlike source was demonstrated using a flat phononic crystal filled with and immersed in water. During these experiments, the importance of imaging in the regime of all angle negative refraction (AANR) was established for obtaining high-quality images. The regime of AANR was achieved in a similar flat crystal, in which the liquid inside the crystal (methanol) was different from the outside medium (water). This design resulted in matching circular equifrequency contours at the frequency of $0.55\phantom{\rule{0.3em}{0ex}}\mathrm{MHz}$, implying that a flat ultrasonic lens with an effective refractive index of $\ensuremath{-}1$ was realized. By imaging a subwavelength line source with this crystal, a resolution of $0.55\ensuremath{\lambda}$ was observed, which is just above the diffraction limit.

CSCD: a database for cancer-specific circular RNAs

Abstract: Circular RNA (circRNA) is a large group of RNA family extensively existed in cells and tissues. High-throughput sequencing provides a way to view circRNAs across different samples, especially in various diseases. However, there is still no comprehensive database for exploring the cancer-specific circRNAs. We collected 228 total RNA or polyA(-) RNA-seq samples from both cancer and normal cell lines, and identified 272 152 cancer-specific circRNAs. A total of 950 962 circRNAs were identified in normal samples only, and 170 909 circRNAs were identified in both tumor and normal samples, which could be further used as non-tumor background. We constructed a cancer-specific circRNA database (CSCD, http://gb.whu.edu.cn/CSCD). To understand the functional effects of circRNAs, we predicted the microRNA response element sites and RNA binding protein sites for each circRNA. We further predicted potential open reading frames to highlight translatable circRNAs. To understand the association between the linear splicing and the back-splicing, we also predicted the splicing events in linear transcripts of each circRNA. As the first comprehensive cancer-specific circRNA database, we believe CSCD could significantly contribute to the research for the function and regulation of cancer-associated circRNAs.

An O2 Self-Sufficient Biomimetic Nanoplatform for Highly Specific and Efficient Photodynamic Therapy

Abstract: Conventional oxygen-dependent photodynamic therapy (PDT) has faced severe challenges because of the non-specificity of most available photosensitizers (PSs) and the hypoxic nature of tumor tissues. Here, an O2 self-sufficient cell-like biomimetic nanoplatform (CAT-PS-ZIF@Mem) consisting of the cancer cell membrane (Mem) and a cytoskeleton-like porous zeolitic imidazolate framework (ZIF-8) with the embedded catalase (CAT) protein molecules and Al(III) phthalocyanine chloride tetrasulfonic acid (AlPcS4, defined as PS) is developed. Because of the immunological response and homologous targeting abilities of the cancer cell membrane, CAT-PS-ZIF@Mem is selectively accumulated at the tumor site and taken up effectively by tumor cells after intravenous injection. After the intracellular H2O2 penetration into the framework, it is catalyzed by CAT to produce O2 at the hypoxic tumor site, facilitating the generation of toxic 1O2 for highly effective PDT in vivo under near-infrared irradiation. By integrating the immune escape, cell homologous recognition, and O2 self-sufficiency, this cell-like biomimetic nanoplatform demonstrates highly specific and efficient PDT against hypoxic tumor cells with much reduced side-effect on normal tissues.

Formation of Yolk-Shelled Ni-Co Mixed Oxide Nanoprisms with Enhanced Electrochemical Performance for Hybrid Supercapacitors and Lithium Ion Batteries

Abstract: Yolk-shelled particles with tailored physical and chemical properties are attractive for electrochemical energy storage. Starting with metal acetate hydroxide with tetragonal prism-like shapes, yolk-shelled Ni–Co mixed oxide nanoprisms with tunable composition have been prepared by simple thermal annealing in air. It is found that the yolk-shelled structure is formed due to the fast thermally driven contraction process. With the favorable porous structure and composition, these yolk-shelled Ni–Co oxide particles manifest greatly enhanced electrochemical properties when evaluated as electrodes for both hybrid supercapacitors and lithium ion batteries. In particular, the resultant Ni0.37Co oxide sample delivers very high specific capacitance of over 1000 F g−1 at a current density of 10 A g−1 with remarkably high capacitance retention of 98% after 15 000 cycles.

Perinatal Transmission of 2019 Coronavirus Disease-Associated Severe Acute Respiratory Syndrome Coronavirus 2: Should We Worry?

Abstract: We present 2 cases of coronavirus disease 2019 (COVID-19)-associated severe respiratory syndrome coronavirus 2 (SARS-CoV-2) infection during the third trimester of pregnancy. Both mothers and newborns had excellent outcomes. We failed to identify SARS-CoV-2 in all of the products of conception and the newborns. This report provided evidence of low risk of intrauterine infection by vertical transmission of SARS-CoV-2.