Optical wireless communication using a flexible and waterproof perovskite color converter.

In this Letter, the CH3NH3PbBr3 nanocrystals (NCs) are embedded into the interstices of the fluorine (polyvinyl fluoride/polyvinylidene fluoride, PVF/PVDF) matrix on polyethylene terephthalate (PET) substrate to introduce new advantages, such as being flexible and waterproof, while maintaining the high optical performance of perovskites. The sample's photoluminescence (PL) spectra under 325 nm laser is a green emission peaked at 537 nm with full width at half maximum (FWHM) of about 21.2 nm and a fast PL decay time. As a color converter, it shows high optical absorption and can transform light from solar-blind ultraviolet to a blue region into a green region in air, water, and bending conditions. While excited by a 270 nm ultraviolet light-emitting diode (LED), the system's observed -3 dB bandwidth with the color converter is near 4.4 MHz in air and water conditions with well-eye diagrams at a data rate of 30 Mbps. Finally, we demonstrate an audio transmission application with an ultraviolet light source, a color conversion layer, and a low-cost silicon-based photodetector.

Precise Control Light Emission of PVDF-CH3NH3PbBr3-xClx Nanocrystalline Films Using a Cl-(CH3OH)n System.

Methylammonium lead halide perovskites with highly efficient pure-color or white-light generation have gained increasing scientific interest and promote the development of a great commercial opportunity in displays, lighting, and other applications. However, the poor stabilities, lead toxicity, and unfriendly solvents and ligands in the growth process severely restrict their commercial application. Here, we proposed a green method for preparing uniform and stable polymer-encapsulated photoluminescence (PL) tunable CH3NH3PbBr3-xClx NC thin films at room temperature. Utilizing the swelling effect between alcohol compounds and organic polymers and the ionization of NaCl in methanol solution, the anion exchange process can be achieved rapidly within 7 min. Moreover, the PL wavelengths of the CH3NH3PbBr3-xClx NCs films were precisely tuned with steps as fine as 2 nm. Experimental results showed that NaCl dissolved in methanol solution can form Cl-(CH3OH)n, which brings ionized Cl into the polymer-encapsulated CH3NH3PbBr3 NCs film for CH3NH3PbBr3-xClx NCs film growth. Based on the swelling and anion exchange dynamics, a modified NaCl-CH3OH-MABr solution system was developed to trigger CH3NH3PbBr3-xClx NCs film PL emission tuning from 528 to 463 nm with several-fold intensity enhancement. The realization of precisely controlled photoluminescence from the perovskite nanocrystal film would have wide applications in the optical and imaging fields.

Quantitative Characterization of Bone Viability of Femoral Head and Subchondral Bone by Using Single Photon Emission Computerized Tomography/Computerized Tomography (SPECT/CT).

BACKGROUND Vascularized fibular grafting (VFG) has been successfully employed for treating avascular necrosis of the femoral head (ANFH). In this study, we aimed to evaluate the bone viability of the femoral head and subchondral bone following VFG by using single photon emission computerized tomography and computerized tomography (SPECT/CT). MATERIAL AND METHODS Between March 2011 and June 2014, 14 ANFH patients (17 hips) treated with VFG at Zhongshan Hospital, Fudan University, were prospectively enrolled. The patients included 9 males and 5 females with an average age of 26.6 years (range, 18-34 years). According to the ARCO (Association Research Circulation Osseous) stage criteria, 3 hips corresponded to stage IIA, 4 hips to stage IIB, 2 hips to stage IIC, 5 hips to stage IIIA, and 3 hips to stage IIIB. A novel method based on SPECT/CT was developed to quantitative characterized the bone viability of femoral head and subchondral bone prior to surgery and at 3 months after VFG. All patients were followed for an average duration of 3.8 years (ranging 2.6-5.5 years). RESULTS The bone viability of the femoral head (Vfh) and subchondral bone (Vsb) of patients' hips at ARCO stage III was 58.9±7.6 and 48.9±6.1, respectively, which were significantly lower than the preoperative Vfh (78.1±5.2) and Vsb (69.8±4.3) of hips at stage II (P<0.05). The Vfh of hips at stage II improved to 104.0±9.7 at 3 months post-intervention, and there was no significant difference compared with the Vfh (97.3±7.4) of hips at stage III (P=0.15). The Vsb of hips at stage III improved to 80.4±7.3 at 3 months after VFG; however, this value was significantly lower than that of hips at stage II (92.7±5.5) (P<0.05). CONCLUSIONS The Vfh and Vsb of our patients were associated with their ARCO stages, and could be improved after vascularized fibular grafting procedure as measured by SPECT/CT.

Enhancement of solid-liquid mixing state quality in a mechanical stirred reactor with serial-chaotic rotation generated by basic speed method.

In this work, a novel controllable chaotic stirring strategy that basic speed with chaotic mappings is proposed to enhance the solid-liquid mixing state quality. Specially, the modern statistical image analysis technique is introduced to explore the intensification mechanism of the mixing process. Results show that the best experimental conditions are obtained by studying the influence of factors such as the type of chaotic mapping, the speed change time, and the basic speed on the mixing state quality. Moreover, the case in which the basic speed is set to 150 r/min generated by the cascaded Logistic-Cubic chaotic mapping is the best while the speed change time is set to 5 s and the fluctuation threshold is 30. The mixing time of this case is 50 s and the shortest, energy consumption is 1.64 × 104 W/m3 and appropriate, the solid particle suspension quality is 83 and the best.

Exosomes from HPV-16 E7-pulsed dendritic cells prevent the migration, M1 polarization, and inflammation of macrophages in cervical cancer by regulating catalase 2 (CAT2).

Background: Cervical cancer is mainly caused by persistent infection with human papillomavirus (HPV), especially HPV-16. Recently, HPV-16 E7-modified dendritic cells (DCs) have been reported to play a blocking role in the progression of cervical cancer. Conversely, the effect and mechanism of HPV-16 E7-pulsed DCs in cervical cancer are not entirely clear. Methods: DCs from the peripheral blood of patients with cervical cancer were induced with lipopolysaccharide and identified through the detection of cluster of differentiation (CD)11c, major histocompatibility complex (MHC)-II, CD83, and CD40 levels, and exosomes from HPV-16 E7-pulsed and catalase 2 (CAT2)-silenced DCs were extracted and identified through transmission electron microscopy and the detection of markers. Additionally, the migration, inflammatory factors, and polarization of macrophages were confirmed using Transwell, enzyme-linked immunoassay, and Western blot of arginase-1 (Arg-1) and inducible nitric oxide synthase (iNOS). In vivo, we also built a mice xenograft model of HPV cervical cancer. Results: We first successfully induced and identified DCs from cervical cancer patients, and successfully extracted and confirmed the exosomes from the constructed HPV-16 E7-pulsed and CAT2-silenced DCs. Subsequently, we proved that exosomes from HPV-16 E7-pulsed DCs restrained migration and inflammation and induced M2 polarization in macrophages, while the effect of exosomes from CAT2-silenced DCs on macrophage migration, polarization, and inflammation was opposite to that of exosomes from HPV-16 E7-pulsed DCs, and the 2 affected each other. Additionally, we found that exosomes from CAT2-silenced DCs also prevented growth and M2 polarization in a mice xenograft model of HPV cervical cancer. Conclusions: Exosomes from HPV-16 E7-pulsed DCs blocked cervical cancer progression by regulating macrophage function, and its mechanism was relevant to CAT2.