While modern industry has contributed to the prosperity of an increasingly urbanized society, it has also led to serious pollution problems, with discharged wastewater and exhaust gases causing ...significant environmental harm. Titanium dioxide (TiO2), which is an excellent photocatalyst, has received extensive attention because it is inexpensive and able to photocatalytically degrade pollutants in an environmentally friendly manner. TiO2 has many advantages, including high chemical stability, low toxicity, low operating costs, and environmental friendliness. TiO2 is an N-order semiconductor material with a bandgap of 3.2 eV. Only when the wavelength of ultraviolet light is less than or equal to 387.5 nm, the valence band electrons can obtain the energy of the photon and pass through the conduction band to form photoelectrons, meanwhile the valence band forms a photogenerated hole. And light in other wavelength regions does not excite this photogenerated electrons. The most common methods used to improve the photocatalytic efficiency of TiO2 involve increasing its photoresponse range and reducing photogenerated-carrier coupling. The morphology, size, and structure of a heterojunction can be altered through element doping, leading to improved photocatalytic efficiency. Mainstream methods for preparing TiO2 are reviewed in this paper, with several excellent preparation schemes for improving the photocatalytic efficiency of TiO2 introduced. TiO2 is mainly prepared using sol-gel, solvothermal, hydrothermal, anodic oxidation, microwave-assisted, CVD and PVD methods, and TiO2 nanoparticles with excellent photocatalytic properties can also be prepared. Ti-containing materials are widely used to purify harmful gases, as well as contaminants from building materials, coatings, and daily necessities. Therefore, the preparation and applications of titanium materials have become globally popular research topics.
Oxidative stress is implicated in cardiac insulin resistance, a critical risk factor for cardiac failure, but the direct evidence remains missing. This study explored a causal link between oxidative ...stress and insulin resistance with a focus on a regulatory role of redox sensitive transcription factor NF-E2-related factor 2 (Nrf2) in the cardiac cells in vitro and in vivo.
Chronic treatment of HL-1 adult cardiomyocyte with hydrogen peroxide led to insulin resistance, reflected by a significant suppression of the insulin-induced glucose uptake. This was associated with an exaggerated phosphorylation of extracellular signal-related kinase (ERK). Although U0126, an ERK inhibitor, enhanced insulin sensitivity and attenuated oxidative stress-induced insulin resistance, LY294002, an inhibitor of phosphoinositide 3-kinase (PI3K), worsened the insulin resistance. Moreover, insulin increased Nrf2 transcriptional activity, which was blocked by LY294002 but enhanced by U0126. Forced activation of Nrf2 by adenoviral over-expression of Nrf2 inhibited the increased ERK activity and recovered the blunted insulin sensitivity on glucose uptake in cardiomyocytes that were chronically treated with H(2)O(2). In the hearts of streptozotocin-induced diabetic mice and diabetic patients Nrf2 expression significantly decreased along with significant increases in 3-nitrotyrosine accumulation and ERK phosphorylation, whereas these pathogenic changes were not observed in the heart of diabetic mice with cardiac-specific overexpression of a potent antioxidant metallothionein. Upregulation of Nrf2 by its activator, Dh404, in cardiomyocytes in vitro and in vivo prevented hydrogen peroxide- and diabetes-induced ERK activation and insulin-signaling downregulation.
ERK-mediated suppression of Nrf2 activity leads to the oxidative stress-induced insulin resistance in adult cardiomyocytes and downregulated glucose utilization in the diabetic heart.
This research was designed to ascertain the function of euchromatic histone lysine methyltransferase 2 (EHMT2) in ischemic stroke-induced neuronal damage and inflammatory response and its regulatory ...mechanism.
Mouse microglia (BV-2 cells) were induced by oxygen glucose deprivation/reoxygenation (OGD/R) to establish a cellular model, and then co-cultured with HT22 hippocampal neurons. After that, HT22 cell viability and apoptosis were evaluated, followed by the measurement of apoptosis-related factors (B-cell lymphoma-2, Bcl-2 associated X, and cleaved-Caspase 3). Meanwhile, the expression of inducible nitric oxide synthase (M1 microglia polarization marker) and arginase 1 (M2 microglia polarization marker) in BV-2 cells was detected, as well as the levels of inflammatory factors (tumor necrosis factor-α, interleukin IL-6, IL-10, IL-1β, and IL-4). Additionally, the expression of EHMT2 and heme oxygenase 1 (HMOX1) in BV-2 cells was assessed by quantitative reverse transcription polymerase chain reaction and western blot, and the binding between EHMT2 and HMOX1 was predicted and verified.
OGD/R treatment led to decreased cell viability and increased cell apoptosis in HT22 cells, and aggravated inflammatory response in BV-2 cells. In OGD/R-induced BV-2 cells, EHMT2 and HMOX1 were increasingly expressed, and knockdown of EHMT2 or HMOX1 in BV-2 cells could inhibit neuronal damage and inflammatory response. Moreover, EHMT2 promoted HMOX1 transcription level by histone methylation.
Collected evidence showed that down-regulation of EHMT2 relieved neuronal damage and inflammatory response by inhibiting HMOX1 expression.
Background/aim
Bone marrow mesenchymal stem cell (BMSC)-derived exosomes can prevent oxidative stress and inflammation in cerebral ischemia-reperfusion injury. This study intended to assess ...influences of BMSC-released exosomes on oxidative stress and inflammation following ischemic stroke.
Methods
In vitro and in vivo models were developed using oxygen-glucose deprivation/reperfusion (OGD/R) and middle cerebral artery occlusion (MCAO), respectively. After exosome isolation, co-culture experiments of BMSCs or BMSC-derived exosomes and OGD/R-treated BV-2 cells were implemented to evaluate the impacts of BMSCs or BMSC-secreted exosomes on proliferation, inflammation, oxidative stress, and apoptosis. The gain-of-function experiments of ZFAS1 or microRNA (miR)-15a-5p were conducted to investigate the associated mechanisms. Besides, MCAO mice were injected with exosomes from BMSCs overexpressing ZFAS1 for in vivo verification. The binding of ZFAS1 to miR-15a-5p was assessed through dual-luciferase reporter gene assay.
Results
Co-culture with BMSCs accelerated proliferation and downregulated IL-1β, IL-6, and TNF-α in OGD/R-exposed BV-2 cells, accompanied by increased SOD level and decreased MDA level and apoptosis, all of which were nullified by inhibiting exosome secretion. Mechanistically, ZFAS1 bound to miR-15a-5p to negatively orchestrate its expression. In addition, BMSC-released exosomes or BMSC-secreted exosomal ZFAS1 augmented proliferation but reduced oxidative stress, apoptosis, and inflammation in OGD/R-exposed BV-2 cells, whereas these impacts of BMSC-released exosomal ZFAS1 were nullified by overexpressing miR-15a-5p. Moreover, BMSC-derived exosomal ZFAS1 diminished MCAO-induced oxidative stress, cerebral infarction, and inflammation in mice.
Conclusions
Conclusively, BMSC-released exosomes might carry long noncoding RNA ZFAS1 to curb oxidative stress and inflammation related to ischemic stroke, which was possibly realized through miR-15a-5p inhibition.
TiO
2
films on a capillary column were prepared using tetrabutoxytitanium as a source of TiO
2
via
the sol-gel method. The film thickness showed a linear increase with tetrabutoxytitanium ...concentration. The specific surface area of the film was improved by adding polyethylene glycol with different molecular weights. Under optimal conditions, the prepared film had a good mesoporous structure with specific surface area of 47.72 m
2
g
−1
, and showed nearly spherical nanoparticles with a 10 nm diameter and anatase phase. Influences of the thickness, specific surface area, and initial solution concentration on photodegradation of rhodamine B using TiO
2
films as a catalyst were investigated. The results showed that the photodegradation efficiency increased with an increasing thickness and specific surface area of TiO
2
films. For a rhodamine B solution of 15 mg L
−1
, the photodegradation efficiency was 98.33% in 30 min under the optimal conditions. The catalysts could be reused up to eight times with almost the same efficiency, indicating a firm immobilization of films on the inner wall of the capillary. Therefore, TiO
2
films are promising for the treatment of wastewater.
TiO
2
films on a capillary column were prepared using tetrabutoxytitanium as a source of TiO
2
via
the sol-gel method.
Single recurrence in the sub-frontal region after cerebellar medulloblastoma (MB) resection is rare and the underlying molecular characteristics have not been specifically addressed.
We summarized ...two such cases in our center. All five samples were molecularly profiled for their genome and transcriptome signatures.
The recurrent tumors displayed genomic and transcriptomic divergence. Pathway analysis of recurrent tumors showed functional convergence in metabolism, cancer, neuroactive ligand-receptor interaction, and PI3K-AKT signaling pathways. Notably, the sub-frontal recurrent tumors had a much higher proportion (50-86%) of acquired driver mutations than that reported in other recurrent locations. The acquired putative driver genes in the sub-frontal recurrent tumors functionally enriched for chromatin remodeler-associated genes, such as KDM6B, SPEN, CHD4, and CHD7. Furthermore, the germline mutations of our cases showed a significant functional convergence in focal adhesion, cell adhesion molecules, and ECM-receptor interaction. Evolutionary analysis showed that the recurrence could be derived from a single primary tumor lineage or had an intermediate phylogenetic similarity to the matched primary one.
Rare single sub-frontal recurrent MBs presented specific mutation signatures that might be related to the under-dose radiation. Particular attention should be paid to optimally covering the sub-frontal cribriform plate during postoperative radiotherapy targeting.
We studied 1,183 Papanicolaou (Pap) cytology cases (739 with normal endometrial cells nEMCs, 423 with atypical EMCs aEMCs, and 21 with endometrial cancer cells EMCCs in women 40 years or older) with ...histologic follow-up. Significant endometrial lesions were found in 2.7%, 18.4%, and 100% of cases with nEMCs, aEMCs, and EMCCs, respectively. Significant lesions were present in women 50 years or older with nEMCs found after day 12 of the menstrual cycle or who were postmenopausal (5.2%), but not in women with nEMCs before day 12 (0.5%) or women younger than 50 years with nEMCs after day 12 (1.6%). Our data indicate that endometrial sampling provides no clinical benefit in women (regardless of age) with nEMCs before day 12 of the menstrual cycle or women younger than 50 years with nEMCs after day 12. Endometrial sampling should be routinely performed in women with aEMCs and in women 50 years or older with nEMCs after day 12 of the menstrual cycle or who are postmenopausal.
Summary In the past several decades, the concept of serous ovarian carcinoma has been revised repeatedly. However, the exact pathogenesis remains controversial. The most popular current concept is ...origin from the epithelium of the fimbriated ends of the fallopian tubes. The objective of our study was to evaluate the characteristic clinical and morphologic features of serous tubal intraepithelial carcinoma (STIC) and associated invasive carcinomas. One hundred sixteen consecutive cases of STIC seen from 2007 to 2011 were included in this study. High-grade serous carcinoma (HGSC) with or without a mixed component was identified in 107 cases (92.2%), non-HGSC in 5 cases, and STICs without invasive carcinoma in 4 cases. Using conventional criteria, HGSCs were classified as fallopian tube in origin in 65 cases (60.7%), as ovarian in 30 (28.0%), as peritoneal in 9 (8.4%), and as endometrial in 3 (2.8%). Among the 107 cases with HGSCs, most STICs (86; 80%) were present unilaterally, whereas invasive tumors more commonly involved the ovaries bilaterally (79%; 84 cases). These findings support the hypothesis that STIC acts as a precursor lesion for most fallopian tube, ovarian, and peritoneal HGSCs, but not for endometrial HGSC.
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