Recently emerged metal halide perovskites have been widely recognized as a promising class of semiconductor materials for next-generation optoelectronic devices, owing to their useful photonic and electronic properties. [1][2][3] Particularly, Lead-free 0D metal halide perovskites are emerging environmentally friendly materials exhibiting large exciton binding energy, which have recently attracted great attention for their excellent light emission properties and favorable stability. Herein, solvent evaporation crystallization at room temperature is adopted to fabricate 0D Cs 3 Cu 2 I 5 perovskite millimeter-sized crystals, which show strong blue photoluminescence (PL) with quantum yield of up to 89%, a large Stockes shift and long (microsecond) PL lifetime, originating from selftrapped excitons. UV pumped light-emitting diodes are demonstrated by using Cs 3 Cu 2 I 5 powder as a solid-state phosphor, and the precursor solution of these perovskite crystals is used as a fluorescent ink. Furthermore, blue-emitting composite Cs 3 Cu 2 I 5 /polyvinylidene fluoride films are produced by spin coating through the solvent evaporation and followed patterning using a direct laser writing technology, which are potentially useful for displays. Finally, the solvent evaporation crystallization method is expanded to fabricate yellow emissive CsCu 2 I 3 crystals by changing the chemical molar ratio of precursor.
Lead halide perovskites have drawn extensive attention over recent decades owing to their outstanding photoelectric performances. However, their toxicity and instability are big issues that need to be solved for further commercialization. Herein, we adopt a facile dry ball milling method to synthesize lead-free
Cs
3
Cu
2
X
5
(
X
=
I
, Cl) perovskites with photoluminescence (PL) quantum yield up to 60%. The optical features including broad emission spectrum, large Stokes shift, and long PL lifetime can be attributed to self-trapped exciton recombination. The as-synthesized blue emissive
Cs
3
Cu
2
I
5
and green emissive
Cs
3
Cu
2
Cl
5
lead-free perovskite powders have good thermal stability and photostability. Furthermore, UV-pumped phosphor-converted light-emitting diodes were obtained by using
Cs
3
Cu
2
I
5
and
Cs
3
Cu
2
Cl
5
as phosphors.
The objective of this study was to evaluate the efficacy of cognitive behavioral therapy intervention for patients who experienced pain during orthodontic treatment. The baseline characteristics were assessed via questionnaires and oral examinations. Four hundred and fifty eligible individuals were recruited and randomized by computer-generated block randomization into three groups: cognitive behavioral therapy intervention (n = 150), ibuprofen intervention (n = 150), and no intervention (control; n = 150). Primary outcomes were the change from baseline in pain intensity measured with 100-mm Visual Analog Scale (VAS) scores at 1, 2, 3, 7, 14, and 30 days after initial archwire placement. Outcomes assessment was blinded and followed the intention-to-treat principle. One hundred forty-three (95.30%), 145 (96.70%), and 141 (94.00%) individuals in the cognitive behavioral therapy, the ibuprofen, and the control groups, respectively, completed the one-month follow-up evaluations. Those in the cognitive behavioral therapy group showed a greater decrease in mean VAS scores than did those in the control group over the previous five time-points (p < 0.001). Cognitive behavioral therapy was shown to be effective in pain control during the initial stage of orthodontic treatment. The study registration number was ChiCTR-TRC-00000556.
Vagus nerve stimulation (VNS) could potentially facilitate arm function recovery after stroke. The aim of this review was to evaluate the effect of VNS paired with rehabilitation on upper limb function recovery after stroke. We considered randomized controlled trials (RCTs) that used VNS paired with rehabilitation for the improvement of upper limb function after stroke and were published in English. Eligible RCTs were identified by searching electronic databases, including MEDLINE, Web of Science, Embase, CENTRAL and PEDro, from their inception until June 2021. Quality of included studies was assessed using PEDro score and Cochrane’s risk of bias assessment. A meta-analysis was performed on the collected data. Five studies with a total of 178 participants met the inclusion criteria. Overall, the present meta-analysis revealed a significant effect of VNS on Fugl–Meyer Assessment for Upper Extremity (FMA-UE, MD = 3.59; 95% CI, 2.55–4.63; P < 0.01) when compared with the control group. However, no significant difference was observed in adverse events associated with device implantation between the invasive VNS and control groups (RR = 1.10; 95% CI, 0.92–1.32; P = 0.29). No adverse events associated with device use were reported in invasive VNS, and one was reported in transcutaneous VNS. This study revealed that VNS paired with rehabilitation can facilitate the recovery of upper limb function in patients with stroke on the basis of FMA-UE scores, but the long-term effects remain to be demonstrated.
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