Hierarchical Supramolecular Self-Assembly: Fabrication and Visualization of Multiblock Microstructures.

Due to the fast dynamics and re-equilibration of supramolecular self-assembly, bottom-up molecular strategies to fabricate well-defined and controllable multiblock structures are rare. Herein, we propose a new concept for fabrication of fluorescent multiblock microcolumns containing 1 to 7 blocks via hierarchical supramolecular self-assembly based on cucurbit[8]uril (CB[8]), NaBr and an AIEgen guest. Through the complexation between CB[8] and different numbers of AIEgen guests (2, 1, 0), the competitive displacement caused by the binding of the sodium cation to the CB[8] portal, and the reversible assembly of positively charged guests in salt solutions, one-pot hierarchical supramolecular self-assembly is realized. The molecular structure of each block is analyzed by single-crystal X-ray diffraction. The AIEgen enables the self-assembly of multiblocks to be visualized, understood, and regulated.

A monolithic InP/SOI platform for integrated photonics.

The deployment of photonic integrated circuits (PICs) necessitates an integration platform that is scalable, high-throughput, cost-effective, and power-efficient. Here we present a monolithic InP on SOI platform to synergize the advantages of two mainstream photonic integration platforms: Si photonics and InP photonics. This monolithic InP/SOI platform is realized through the selective growth of both InP sub-micron wires and large dimension InP membranes on industry-standard (001)-oriented silicon-on-insulator (SOI) wafers. The epitaxial InP is in-plane, dislocation-free, site-controlled, intimately positioned with the Si device layer, and placed right on top of the buried oxide layer to form "InP-on-insulator". These attributes allow for the realization of various photonic functionalities using the epitaxial InP, with efficient light interfacing between the III-V devices and the Si-based waveguides. We exemplify the potential of this InP/SOI platform for integrated photonics through the demonstration of lasers with different cavity designs including subwavelength wires, square cavities, and micro-disks. Our results here mark a critical step forward towards fully-integrated Si-based PICs.

Upside-Down Molding Approach for Geometrical Parameter-Tunable Photonic Perovskite Nanostructures.

Considering that the periodic photonic nanostructures are commonly realized by expensive nanofabrication processes and the tunability of structure parameters is limited and complicated, we demonstrate a solution-processed upside-down molding method to fabricate photonic resonators on perovskites with a pattern geometry controllable to a certain extent. This upside-down approach not only reveals the effect of capillary force during the imprinting but also can control the waveguide layer thickness due to the inversion of the perovskite membranes.

A study protocol for a randomized controlled trial evaluating vibration therapy as an intervention for postural training and fall prevention after distal radius fracture in elderly patients.

BACKGROUND: Fractures of the distal radius are one of the most common osteoporotic fractures in elderly men and women. These fractures are a particular health concern amongst the elderly, who are at risk of fragility fractures, and are associated with long-term functional impairment, pain and a variety of complications. This is a sentinel event, as these fractures are associated with a two to four times increased risk of subsequent hip fractures in elderly patients. This is an important concept, as it is well established that these patients have an increased risk of falling. Fall prevention is therefore crucial to decrease further morbidity and mortality. The purpose of this study is to investigate the effect of low-magnitude high-frequency vibration (LMHFV) on postural stability and prevention of falls in elderly patients post distal radius fracture. METHODS: This is a prospective single-blinded randomized controlled trial. Two hundred patients will be recruited consecutively with consent, and randomized to either LMHFV (n = 100) or a control group (n = 100). The primary outcome is postural stability measured by the static and dynamic ability of patients to maintain centre of balance on the Biodex Balance System SD. Secondary outcomes are the occurrence of fall(s), the health-related quality of life 36-item short form instrument, the Timed Up and Go test for basic mobility skills, compliance and adverse events. Outcome assessments for both groups will be performed at baseline (0 month) and at 6 weeks, 3 months and 6 months time points. DISCUSSION: Previous studies have stressed the importance of reducing falls after distal radius fracture has occurred in elderly patients, and an effective intervention is crucial. Numerous studies have proven vibration therapy to be effective in improving balancing ability in normal patients; However, no previous study has applied the device for patients with fractures. Our study will attempt to translate LMHFV to patients with fractures to improve postural stability and prevent recurrent falls. Positive results would provide a large impact on the prevention of secondary fractures and save healthcare costs. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03380884. Registered on 21 December 2017.

Telecom InP/InGaAs nanolaser array directly grown on (001) silicon-on-insulator.

A compact, efficient, and monolithically grown III-V laser source provides an attractive alternative to bonding off-chip lasers for Si photonics research. Although recent demonstrations of microlasers on (001) Si wafers using thick metamorphic buffers are encouraging, scaling down the laser footprint to nanoscale and operating the nanolasers at telecom wavelengths remain significant challenges. Here, we report a monolithically integrated in-plane InP/InGaAs nanolaser array on (001) silicon-on-insulator (SOI) platforms with emission wavelengths covering the entire C band (1.55 µm). Multiple InGaAs quantum wells are embedded in high-quality InP nanoridges by selective-area growth on patterned (001) SOI. Combined with air-cladded InP/Si optical cavities, room-temperature operation at multiple telecom bands is obtained by defining different cavity lengths with lithography. The demonstration of telecom-wavelength monolithic nanolasers on (001) SOI platforms presents an important step towards fully integrated Si photonics circuits.

Spinal phantom comparability study of Cobb angle measurement of scoliosis using digital radiographic imaging.

BACKGROUND: Computed radiography (CR), digital radiography (DR) and biplanar radiography (EOS™ imaging system) are common imaging tools for radiographic evaluation of adolescent idiopathic scoliosis (AIS). The effect of imaging methods in relation to later-on Cobb angle measurements on radiographs is not yet quantified. The study aimed to examine the compatibility between CR, DR and EOS for scoliotic quantification by evaluating the reliability, agreement of different imaging methods, and assessing the prediction performance for EOS measurement from that of CR and DR. METHOD: A flexible spine phantom was used to simulate 32 different scoliotic curves ranging from 10° to 60°. Each curvature was imaged using DR, CR and EOS systems accordingly. Each of the six observers independently measured Cobb angle twice on each image at a two-week interval. Intraclass correlation coefficient (model 2 and 3), Bland-Altman plot and linear regression analysis were completed to evaluate the reliability, agreement, and the prediction of Cobb angle measurement, respectively. RESULTS: Reliability analysis showed excellent intra-observer reliability (Intraclass correlation coefficient >0.9) for each observer and good inter-observer reliability (Intraclass correlation coefficient = 0.84 for EOS; 0.739 for CR; 0.877 for DR) for each method. Bland-Altman plots demonstrated good agreement between imaging methods without fixed or proportional bias. Excellent coefficient of determination was achieved, with 0.980 for CR versus EOS measurements, and 0.973 for DR versus EOS measurements. CONCLUSIONS: Radiographs produced by all of the three methods can provide reliable and accurate Cobb angle measurements for scoliosis assessments. None of the methods systemically underestimates or overestimates the Cobb angle measurement. Additionally, all of the evaluated methods are satisfactory in obtaining images for Cobb angle measurement in AIS. However, the 3D post-processing techniques offered by EOS should also be taken into consideration as it takes a vital role in treatment and monitoring of 3D deformity in the case of scoliosis. THE TRANSLATIONAL POTENTIAL OF THIS ARTICLE: In view of the limited availability of biplanar radiography (EOS™ imaging system), computed radiography and digital radiography are demonstrated to be reliable alternatives in scoliosis monitoring as evident in the reliability, agreement and prediction of Cobb angle measurement.