Liquid lasing from solutions of ligand-engineered semiconductor nanocrystals.

Semiconductor nanocrystals (NCs) can function as efficient gain materials with chemical versatility because of their surface ligands. Because the properties of NCs in solution are sensitive to ligand-environment interactions, local chemical changes can result in changes in the optical response. However, amplification of the optical response is technically challenging because of colloidal instability at NC concentrations needed for sufficient gain to overcome losses. This paper demonstrates liquid lasing from plasmonic lattice cavities integrated with ligand-engineered CdZnS/ZnS NCs dispersed in toluene and water. By taking advantage of calcium ion-induced aggregation of NCs in aqueous solutions, we show how lasing threshold can be used as a transduction signal for ion detection. Our work highlights how NC solutions and plasmonic lattices with open cavity architectures can serve as a biosensing platform for lab-on-chip devices.

Uncovering Art's Vanishing Hues with Surface-Enhanced Raman Scattering: Drawing Inspiration from the Past for the Future.

The aesthetic and historical significance of art is well recognized; art can stoke emotions, invite close inquiry, and connect us to the past. However, works of art are also complex material objects that present unique challenges and opportunities for the scientific community. Identifying "fugitive" organic pigments in traditional oil paintings, for example, presents a particularly complex analytical challenge that is critical to address for their conservation and long-term preservation. In this Perspective, we discuss the benefits and technical challenges of applying surface-enhanced Raman scattering (SERS) spectroscopy to the ultrasensitive identification of fugitive pigments in paintings as well as future developments in SERS we envision that are inspired by the past.

Risk assessment for sandwich vertebral fractures in the treatment of osteoporosis vertebral compression fractures using two methods of bone cement reinforcement.

PURPOSE: Bone cement augmentation surgery includes percutaneous vertebroplasty (PVP) and percutaneous kyphoplasty (PKP). In this study, we aimed to investigate the risk of sandwich vertebral fractures in the treatment of osteoporotic vertebral compression fractures via PVP and PKP. METHODS: We performed a retrospective analytical study and included 61 patients with osteoporotic vertebral compression fractures who underwent PVP and PKP at the Spinal Surgery Department of The Second Hospital of Liaocheng Affiliated with Shandong First Medical University from January 2019 to January 2022. These patients were divided into the following two groups by simple random sampling: group A (N = 30) underwent PVP treatment and group B (N = 31) underwent PKP treatment. The surgical time, fluoroscopy frequency, visual analog scale (VAS) score, amount of bone cement, the leakage rate of bone cement in intervertebral space, Cobb angle, and the incidence of fractures in both groups of sandwich vertebral were recorded after 1 year of follow-up. RESULTS: No statistically significant difference was found in terms of surgical time, fluoroscopy frequency, and VAS score between the two groups (P > 0.05). However, a statistically significant difference was found in terms of the amount of bone cement, the leakage rate of bone cement intervertebral space, Cobb angle, and the incidence of vertebral body fractures in both groups (P < 0.05). The amount of bone cement, the leakage rate of bone cement in intervertebral space, Cobb angle, and sandwich vertebral fractures were higher in Group A than in Group B. CONCLUSIONS: When PVP and PKP were performed to treat osteoporotic vertebral compression fractures, the sandwich vertebral exhibited a risk of fracture. PVP exhibited a greater relative risk than PKP, which may be due to the relatively larger amount of bone cement, higher rate of bone cement leakage in the intervertebral space, and larger Cobb angle.

Expression of miR-195 and its target gene Bcl-2 in human intervertebral disc degeneration and their effects on nucleus pulposus cell apoptosis.

OBJECTIVE: To investigate the expression of miR-195 and its target gene Bcl-2 in intervertebral disc degeneration (IVDD) and its effect on nucleus pulposus (NP) cell apoptosis. METHODS: The expressions of miR-195 and Bcl-2 in NP tissues of IVDD patients were quantified by qRT-PCR and western blotting, respectively. NP cells were divided into blank group, TNF-α group, TNF-α + miR-NC group, TNF-α + siBcl-2 group, and TNF-α + miR-195 inhibitors + siBcl-2 group. Cell proliferation was detected by MTT assay, cell apoptosis evaluated by flow cytometry, and mitochondrial membrane potential (MMP) tested by JC-1 staining. Moreover, the function of miR-195 on IVDD in vivo was investigated using a puncture-induced IVDD rat model. RESULTS: IVDD patients had significantly increased miR-195 expression and decreased Bcl-2 protein expression in NP tissues. The expression of miR-195 was negatively correlated with the expression of Bcl-2 in IVDD patients. Dual-luciferase reporter gene assay indicated that Bcl-2 was a target gene of miR-195. In comparison with blank group, TNF-α group showed decreased cell proliferation and MMP, increased cell apoptosis, upregulated expression of miR-195, Bax, and cleaved caspase 3, and downregulated Bcl-2 protein, while these changes were attenuated by miR-195 inhibitors. Additionally, siBcl-2 can reverse the protective effect of miR-195 inhibitors on TNF-α-induced NP cells. Besides, inhibition of miR-195 alleviated IVDD degeneration and NP cell apoptosis in the rat model. CONCLUSION: MiR-195 was significantly upregulated in NP tissues of IVDD patients, and inhibition of miR-195 could protect human NP cells from TNF-α-induced apoptosis via upregulation of Bcl-2.

Preparation of pentafluorosulfanyl (SF5) pyrrole carboxylic acid esters.

Pyrrole derivatives bearing a pentafluorosulfanyl group are currently unknown. In this paper, a facile preparation of SF5-substituted pyrrole carboxylic acid esters in good yield is reported. Utilizing the cycloaddition of an azomethine ylide to pentafluorosulfanylalkynes, a series of dihydropyrroles were prepared and oxidized to the respective 1-tert-butyl-4-(pentafluorosulfanyl)pyrrole-2-carboxylic acid esters in good yield. Further treatment of these pyrroles with catalytic triflic acid allowed removal of the tert-butyl group.