Enhanced Efficiency and Stability of Sky Blue Perovskite Light-Emitting Diodes via Introducing Lead Acetate.

All-inorganic metal halide perovskite is promising for highly efficient and thermally stable perovskite light-emitting diodes (PeLEDs). However, there is still great room for improvement in the film quality, including low coverage and high trap density, which play a vital role in achieving high-efficiency PeLEDs. In this work, lead acetate (Pb(Ac)2) was introduced into the perovskite precursor solution as an additive. Experimental results show that perovskite films deposited from a one-step anti-solvent free solution process with increased surface coverage and reduced trap density were obtained, leading to enhanced photoluminescence (PL) intensity. More than that, the valence band maximum (VBM) of perovskite films was reduced, bringing about a better energy level matching the work function of the hole-injection layer (HIL) poly (3,4-ethylenedioxythiophene)-poly (styrene sulfonate) (PEDOT: PSS), which is facilitated for the hole injection, leading to a decrease in the turn-on voltage (Vth) of PeLEDs from 3.4 V for the control device to 2.6 V. Finally, the external quantum efficiency (EQE) of the sky blue PeLEDs (at 484 nm) increased from 0.09% to 0.66%. The principles of Pb(Ac)2 were thoroughly investigated by using X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). This work provides a simple and effective strategy for improving the morphology of perovskite and therefore the performance of PeLEDs.

Reproductive and transgenerational toxicity of bisphenol S exposure in pregnant rats: Insights into hormonal imbalance and steroid biosynthesis pathway disruption.

Bisphenol S (BPS) is an alternative chemical to bisphenol A commonly used in food packaging materials. It raises concerns due to potential adverse effects on human health. However, limited evidence exists regarding reproductive toxicity from BPS exposure, and the mechanism of associated transgenerational toxicity remains unclear. In this study, pregnant SD rats were exposed to two different doses of BPS (0.05 or 20 mg/kg) from GD6 to PND21. The objective was to investigate reproductive and transmissible toxicity induced by BPS, explore endocrine effects, and uncover potential underlying mechanisms in rats. Perinatal exposure to BPS in the F0 generation significantly decreased the rate of body weight, ovarian organ coefficient, and growth and development of the F1 generation. Notably, these changes included abnormal increases in body weight and length, estrous cycle disruption, and embryonic dysplasia in F1. 4D-DIA proteomic and PRM analyses revealed that exposure to 20 mg/kg group significantly altered the expression of proteins, such as Lhcgr and Akr1c3, within the steroid biosynthetic pathway. This led to elevated levels of FSH and LH in the blood. The hypothalamic-pituitary-ovarian (HPO) axis, responsible for promoting fertility through the cyclic secretion of gonadotropins and steroid hormones, was affected. RT-qPCR and Western blot results demonstrated that the expression of GnRH in the hypothalamus was decreased, the GnRHR in the pituitary gland was decreased, and the expression of FSHß and LHß in the pituitary gland was increased. Overall, BPS exposure disrupts the HPO axis, hormone levels, and steroid biosynthesis in the ovaries, affecting offspring development and fertility. This study provides new insights into the potential effects of BPS exposure on the reproductive function of the body and its relevant mechanisms of action.

Benign esophageal schwannoma: A case report and brief overview.

RATIONALE: Schwannoma is a tumor of the peripheral nervous system that originated in the Schwann cells of the neural sheath. Esophageal schwannomas are rare esophageal submucosal tumors, comprising approximately 2% of esophageal tumors. Since the symptoms, signs, and images of esophageal schwannoma are not specific, its preoperative diagnosis remains challenging. PATIENT CONCERNS: A 67-year-old woman visited our department with complaints of gradually developed dysphagia and dyspnea for 4 years. A chest computed tomography scan showed a well-demarcated, enhancing homogeneous tumor measuring 61 × 46 × 60 mm in the upper third of the esophagus. Upper gastrointestinal endoscopy revealed a smooth elevated lesion located 19 to 24 cm from the incisor teeth. An endoscopic ultrasound-guided fine-needle aspiration demonstrated the presence of benign spindle cells. DIAGNOSES: Histopathologic examination revealed spindle-shaped cells in a fasciculated and disarrayed architecture. The immunohistochemical study showed positivity for S-100 protein antibody and absence of staining for CD117, CD34, smooth muscle actin, and Desmin. These findings confirmed the diagnosis of benign esophageal schwannoma. INTERVENTIONS: The tumor was considered to be difficult to repair the esophagus by direct anastomosis after tumor resection. Therefore, subtotal esophagectomy and esophagogastrostomy in the right thorax were performed. OUTCOMES: The patient has been doing well with no recurrence at 36 months after the operation. LESSONS: The symptoms and surgical procedures for benign esophageal schwannoma depend on the size and location of the tumor, proper and timely treatment is essential. A definitive diagnosis is confirmed by histology, and complete excision should yield good results.

Influence of patterned titanium coatings on polarization of macrophage and osteogenic differentiation of bone marrow stem cells.

Biomaterial surface topography plays a vital role in the osteointegration of implants by regulating the early cell responses and tissue growth-in. However, most of the previous researches focused on the effects of osteogenic cells, only a little is known about the immune cells which dominate osteogenesis after implanting. In this paper, patterned titanium coatings were fabricated and the effects of surface topography on the macrophage behaviors were investigated. On patterned titanium surface, macrophages preferred to polarize to M2, while macrophages on traditional titanium coatings presented higher M1 polarization. Nearly 70% higher expression of anti-inflammatory genes, including interleukin-4, interleukin-10, interleukin-1ra, and arginase, were detected on the patterned titanium coatings. While the pro-inflammatory genes, such as interleukin-1ß, interleukin-6, tumor necrosis factor-α, interferon-γ, and inducible nitric oxide synthase were notably depressed. Up-regulation of the osteoinductive cytokines were also detected on the patterned coatings, which indicated advantageous osteogenic microenvironment provided by macrophages. Immunomodulation effect on osteogenesis was also investigated in this study. Stimulated with RAW cells/patterned coatings conditioned medium, bone marrow stem cells presented nearly 1.5 fold higher expression of osteogenic genes and more mineralization nodules than the traditional sprayed Ti coatings. All these results suggested that modulating materials with a patterned surface might be a valuable strategy to endow the implants with favorable osteoimmunomodulatory properties.

Vancomycin-loaded titanium coatings with an interconnected micro-patterned structure for prophylaxis of infections: an in vivo study.

Titanium (Ti) and its alloys are widely applied as orthopedic implants for hip and knee prostheses, fixation, and dental implants. However, Ti and its alloys are bioinert and susceptible to bacteria and biofilm formation. Thus, surface biofunctionalisation of Ti is essential for improving the biofunction of Ti. The current in vitro study indicated that calcium phosphate bone cement with vancomycin doped on micro-patterned Ti with a grid-like structure surface could preserve the property of inhibition of bacterial adhesion and biofilm formation while not affecting the osteogenic differentiation. The present study investigated whether the biological performance of the bactericidal effect is preserved in vivo. The rabbit osteomyelitis model with tibial medullary cavity placement of Ti rods was employed to analyze the antibacterial effect of vancomycin-loaded Ti coatings with interconnected micro-patterned structure (TV). Thirty female rabbits (N = 10) were used to establish the implant-associated infection. Prior to implanting the T0 and TV rods into the medullary cavity of the left tibia of the rabbits, 106 CFU mL-1 methicillin-resistant Staphylococcus aureus (MRSA) was injected into the medullary cavity of the left tibia of the rabbits. The sterile Ti rod (NT) was used as the blank control. After 3 weeks, bone pathology was evaluated using X-ray and micro-CT. The in vivo study proposed that TV has the potential for prophylaxis against MRSA infection. Thus, the interconnected micro-patterned structured Ti rods loaded with vancomycin could be applied for preventing Ti implant-associated infections.

YAP-mediated mechanotransduction regulates osteogenic and adipogenic differentiation of BMSCs on hierarchical structure.

Hierarchical structure mimicking the natural bone microenvironment has been considered as a promising platform to regulate cell functions. We have previously fabricated hierarchical macropore/nanowire structure and evidence has shown that it can better manipulate the cytoskeleton status and osteogenic performance of osteoblasts. However, how cues of hierarchical structure are translated and ultimately linked to BMSC lineage commitment have still remained elusive, which hinders the accurate knowledge and further development of the hierarchical structure. In this study, bone marrow-derived mesenchymal stem cells (BMSCs) fate on hierarchical structure was investigated as well as the detailed mechanisms. It was shown that well-developed cytoskeleton and focal adhesion were observed for BMSCs on hierarchical structure, which was accompanied by enhanced osteogenic and depressed adipogenic potential. Evidence of increased YAP activity and nuclear translocation were exhibited on hierarchical structure and YAP knockdown inhibited osteogenic differentiation and promoted adipogenic differentiation induced by hierarchical structure. Further remove of cytoskeleton tension inhibited YAP function, which confirmed the key role of YAP-mediated mechanotransduction in the BMSC differentiation. These results together provide information of the stem cell fate commitment on hierarchical structure and a promising approach to design advanced biomaterials by focusing on specific mechanotransduction process.

Immunomodulation effect of a hierarchical macropore/nanosurface on osteogenesis and angiogenesis.

Immune systems play pivotal roles in determining the in vivo osseointegration of bone implants. While much evidence has shown that hierarchical implant surfaces can exhibit excellent osteogenic ability, their immune response has not been well elucidated, which will preclude accurate knowledge of their osseointegration performance. In this study, the immunomodulatory properties of a hierarchical macropore/nanosurface as well as the detailed mechanism was investigated. Macrophages were found to switch to M2 phenotype on the hierarchical surface, and decreased levels of inflammatory gene expression as well as increased expression of anti-inflammatory genes were endowed, which were probably regulated by the decisive role of cytoskeleton tension induced by specific cell shape. In addition, enhanced osteogenic differentiation of bone marrow mesenchymal stem cells and angiogenesis of human umbilical vein endothelial cells could be observed when stimulated by a RAW cells/hierarchical surface conditioned medium, which were probably due to increased expression of BMP-2 and VEGF of RAW cells, respectively. These findings give comprehensive knowledge into detailed mechanism of the immunomodulatory behavior of the hierarchical surface, which will also provide insight into the surface design of advanced bone biomaterials with satisfactory immunomodulation properties.