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Two-way shape memory polymer can exhibit reversible shape transformation, which shows great application potential as a smart material. It is necessary to develop new reversible shape memory composite systems to achieve accurate and wide-range control of two-way shape memory behavior, especially under the condition of no external force. A chemically cross-linked two-component crystalline block copolymer was prepared based on the independence of crystallization of PLA and PCL. The mechanism of two-way shape memory behavior under stress-free condition of the material is revealed. The results show that both the crystallization and thermal property of PLA/PCL-PU can be significantly changed by adjusting the proportion between PLA and PCL, and the dosage of crosslinking agent, and thus the shape memory property of PLA/PCL-PU can be regulated accordingly. The two-way shape recovery rate of the material can reach to 41.11%. This work provides a facile strategy to fabricate a biodegradable thermally induced two-way shape memory material under the stress-free condition with tunable shape memory properties.

Background Emergency department (ED) visits associated with prescription opioids have increased in the last ten years. This study describes the opioid utilization of patients discharged from the ED with an opioid prescription for pain, 14 to 21 days post discharge. Methods This is a prospective, single-centered, survey-based observational descriptive study conducted from December 2017 to February 2018 in the ED at a tertiary level 1 trauma center. The primary outcomes were the percentage of patients with unused opioids and the quantity of opioids remaining 14 to 21 days post ED discharge. A sample of ED patients who received an oral opioid prescription were approached for informed consent and received a telephone survey 14 to 21 days post discharge. Results Of 178 patients approached for consent, 122 were enrolled. Among them, 98 were successfully surveyed (80.3%). The median number of pills prescribed was 8 (IQR:8–12). Nearly half (49%) of patients had unused opioids 14 to 21 days post ED discharge, not including 9.2% of patients who never filled their prescriptions. Of the total 980 pills prescribed, 327 pills remained unused (33.4%). Only 55.1% of patients reported receiving counseling on side effect of opioids and 21.4% of patients reported they received counseling on storage and disposal. Conclusion The majority of patients in this study had unused or unfilled opioids 14 to 21 days post ED discharge, and approximately one third of the opioids prescribed remained unused. Most patients did not recall receiving opioid related education including proper disposal of medication.

Restricted arc-connectivity is a more refined network reliability index than arc-connectivity. An arc subset [Formula: see text] of a strong digraph [Formula: see text] is a restricted arc-cut of [Formula: see text] if [Formula: see text] has a non-trivial strong component [Formula: see text] such that [Formula: see text] contains an arc. The restricted arc-connectivity is the minimum cardinality over all restricted arc-cuts of [Formula: see text]. A strong digraph is super-[Formula: see text] if its restricted arc-connectivity is maximal and the number of its minimum restricted arc-cuts is minimal. In this paper, we present some neighborhood conditions for a digraph to be super-[Formula: see text].

Developing integrable, nanoscale, and low-energy-consumption lasers is a crucial step toward on-chip optical communications and computing technologies. The strong exciton-photon interaction that emerged in monolayer transition metal dichalcogenides (TMDs) holds promise for engineering and integration. Herein, we prepare the MoSe2/microsphere cavities excitonic lasers by placing SiO2 microspheres on top of a monolayer MoSe2 film. By virtue of continuous-wave exciting MoSe2/microsphere whispering gallery mode (WGM) cavities, we realize multiple excitonic WGM lasing in the emission wavelength range of ∼750-875 nm at room temperature with tunable properties of free spectral range (FSR) and full width at half-maximum (fwhm) by varying the microsphere size. Theoretical calculations based on the finite element method (FEM) using COMSOL software were utilized to identify lasing modes and reveal the corresponding electric field distribution. These findings help to deepen fundamental understanding of excitonic WGM lasing and provide a promising research platform for integrable, scalable, and low-cost laser devices.

Recently, several plexins and semaphorins have been associated with osteoclastogenesis, a vital process for bone remodeling. Plexin-A2 is implicated in bone homeostasis, however, whether it plays a role in osteoclastogenesis and the underlying mechanism remain unknown. We show that plexin-A2 expression is upregulated during RANKL-induced osteoclastogenesis. In addition, the soluble Sema6A fused with IgG1 Fc region (Fc-Sema6A) interacts with plexin-A2 from cell lysates of osteoclasts, suggesting that plexin-A2 acts as a receptor of Sema6A in osteoclasts. Moreover, Sema6A treatment stimulates RANKL-induced osteoclastogenesis, and this effect is abolished when plexin-A2 is neutralized, which illustrates an indispensable role of plexin-A2 in mediating Sema6A effect on osteoclastogenesis. Mechanistically, Sema6A-plexin-A2 axis enhances RANKL-induced activation of PLCγ as well as downstream target NFATc1, one master transcriptional factor of osteoclastogenesis. Lastly, inhibition of PLCγ by pharmacological inhibitor U73122 abrogates Sema6A-stimulated NFATc1 activation and RANKL-induced osteoclastogenesis, thus demonstrating that the PLCγ-mediated NFATc1 activation accounts for the promotive role of Sema6A-plexin-A2 axis in RANKL-induced osteoclastogenesis. Taken together, this study uncovers a novel role of Sema6A and plexin-A2 in osteoclastogenesis, and also offers them as possible therapeutic targets in the intervention of osteolytic diseases.

Developing integrable, nanoscale, and low-energy-consumption lasers is a crucial step toward on-chip optical communications and computing technologies. The strong exciton-photon interaction that emerged in monolayer transition metal dichalcogenides (TMDs) holds promise for engineering and integration. Herein, we prepare the MoSe

A cross-linked film, based on corn starch/hydroxymethylated alkali lignin, was prepared. The effects of solution casting, pH, and reactant stoichiometries on water absorbability and mechanical properties of the starch/lignin film were studied. The microstructure, morphology, moisture absorbability, and thermal properties of the film were also evaluated. Results showed that the starch/lignin composite film, cast under optimized conditions, was homogeneous and soft. The tensile strength and elongation ratio of the composite film were higher than that of the corn starch film. At a temperature, higher than 320°C, the weight loss rate of the starch/lignin film was lower than that of the starch film and its char residue at 750°C was more than the corn starch film. This showed that the starch/lignin film had better thermal stability at higher temperatures. More importantly, the water absorption rate of starch/lignin film was 238 ± 3 %, which was 1.3 times than that of the corn starch film. The moisture content of the film was also higher than the corn starch sample. Hence, the prepared starch/lignin cross-linked film can be used as a biodegradable, water absorbent material for packaging and in agricultural mulching.

Crystallization kinetics of 2-chloro-4,6-dinitroresorcinol in ethanol was studied by the method of intermittent dynamic analysis. The nucleation rate and crystal growth rate of 2-chloro-4,6-dinitroresorcinol under different crystallization temperatures and stirring rates were estimated. The results show that with an increase of crystallization temperature, both the nucleation rate and crystal growth rate increase. It is further found that when the stirring rate increases, the nucleation rate increases and the crystal growth rate decreases. The technological conditions of cooling crystallization of 2-chloro-4,6-dinitroresorcinol were studied. It is found that when the stirring rate is 180 rpm and the solution is cooled slowly to − 8°C, the particle size of the products is even and the highest yield of 2-chloro-4,6-dinitroresorcinol is 40.6%.

The crystallization kinetics of 2-chloro-4,6-dinitro-resorcinol were studied by the method of intermittent dynamic analysis. The nucleation rate and crystal growth rate of 2-chloro-4,6-dinitro-resorcinol under three groups of conditions (27°C, 180 rpm; 33°C, 180 rpm; 33°C, 240 rpm) were estimated. The results show that, by increasing the temperature of the solution, both the nucleation rate and crystal growth rate increase. It is further found that, when the stirring rate increases, the nucleation rate increases and the crystal growth rate decreases. On the basis of the study of the crystallization kinetics, the effect of the operational parameters on the crystallization was studied. It is proved that, when the stirring rate is 180 rpm and the solution is cooled slowly to −8°C, the particle size of the crystals is even, the quality of the crystals is good, and the yield of the crystals is 40.6%.

The correlations between temperature sensitivity (relative sensitivity Sr and absolute sensitivity Sa) and thermally coupled level gaps (ΔE) are vital but less-studied for potential applications in scientific research, industrial production, clinical medicine, and so on. We take YbPO4:Ln3+ (Ln = Tm3+, Ho3+, and Er3+) up-conversion phosphors as a case to study the relationships between temperature sensitivity (Sr, Sa) and ΔE. The results of various discussions, including the experimental data of temperature sensitivity based on YbPO4:Ln3+ (Ln = Tm3+, Ho3+, and Er3+) and theoretical derivation from original formulas, show that Sr and ΔE are linearly positive correlation, which is invalid for Sa. Noticeably, YbPO4:Tm3+ nanoparticles display intense near infrared red emission within the biological window, leading to great potential application in biological sensing and biological imaging. All the research studies would benefit the design of optical temperature sensing.

With the rapid development of the economy, , bridge construction, as one of the elements of modern traffic engineering often becomes the key part which restricts the whole construction. The external pre-stressing technique of precast segmental construction gets more and more attention in modern bridge construction because of its unique advantage. However, as a special structure of precast segmental construction, the joint’s strength and connection reliability is closely related to stress and service performance of the pre-spliced structure. So it is necessary to analyze the structure and mechanical properties of the joint. For the research of the joint in precast segmental construction applied in externally pre-stressed concrete bridges, this paper introduces the types and characteristics of joint structure, and uses the similar sectional analysis method of internal pre-stressing structure to analyze the bending performance and shear performance in a cross-section of a joint. At the same time, on the basis of the consideration of the secondary effect of external pre-stressing, some kinds of common calculation formulas used for bearing capacity calculation in the cross-section of the joints are given. Finally, results of numerical simulation analysis by the finite element program ANSYS and some experimental study from both at home and abroad prove the rationality of these formulas.