No abstract

Two-dimensional (2D) molybdenum disulfide (MoS₂) field-effect transistors (FETs) have been extensively studied, but most of the FETs with gate insulators have displayed negative threshold voltage values, which indicates the presence of interfacial traps both shallow and deep in energy level. Despite such interface trap issues, reports on trap densities in MoS₂ are quite limited. Here, we probed top-gate MoS₂ FETs with two- (2L), three- (3L), and four-layer (4L) MoS₂/dielectric interfaces to quantify deep-level interface trap densities by photo-excited charge collection spectroscopy (PECCS), and reported the result that deep-level trap densities over 10(12) cm(-2) may exist in the interface and bulk MoS₂ near the interface. Transfer curve hysteresis and PECCS measurements show that shallow traps and deep traps are not that different in density order from each other. We conclude that our PECCS analysis distinguishably provides valuable information on deep level interface/bulk trap densities in 2D-based FETs.

Clinical trials of gene therapy using a viral delivery system for glioma have been limited. Recently, gene therapy using stem cells as the vehicles for delivery of therapeutic agents has emerged as a new treatment strategy for malignant brain tumors. In this study, we used human umbilical cord blood-derived mesenchymal stem cells (UCB-MSCs) as delivery vehicles with glioma-targeting capabilities, and modified interleukin-12 (IL-12p40N220Q; IL-12M) as a novel therapeutic gene. We also engineered UCB-MSCs to secret IL-12M (UCB-MSC-IL12M) via tetrameric cell-permeable peptide (4HP4)-mediated adenoviral transduction. We confirmed the migratory capacity of UCB-MSC-IL12M toward GL26 mouse glioma cells by an in vitro migration assay and in vivo injection of UCB-MSC-IL12M into the ipsilateral hemisphere of implanted gliomas in C57BL/6 mice. In vivo efficacy experiments showed that intratumoral injection of UCB-MSC-IL12M significantly inhibited tumor growth and prolonged the survival of glioma-bearing mice compared with control mice. Antitumor effects were associated with increased local IL-12M levels, followed by interferon-γ secretion and T-cell infiltration in intracranial gliomas, as well as antiangiogenesis. Interestingly, tumor-free mice after UCB-MSC-IL12M treatment were resistant to ipsilateral and contralateral tumor rechallenge, which was closely associated with tumor-specific long-term T-cell immunity. Thus, our results provide the rationale for designing novel experimental protocols to induce long-term antitumor immunity against intracranial gliomas using UCB-MSCs as an effective delivery vehicle for therapeutic cytokines including IL-12M.

Baicalin (baicalein-7-glucuronide) is a flavonoid purified from Scutellaria baicalensis Georgi that has traditionally been used for treatment of hypertension, cardiovascular diseases, and viral hepatitis. In this study, the effects of intestinal microbiota on the pharmacokinetics of baicalin were investigated in normal and antibiotic-pretreated rats following p.o. administration of 100 mg/kg baicalin by using liquid chromatography/ion trap mass spectrometry. When rats were pretreated orally with cefadroxil, oxytetracycline and erythromycin for 3 days to control the number of intestinal bacteria, the pharmacokinetic parameters of oral baicalin were significantly affected by antibiotics: Cmax, T1/2(β), Kel and AUC values were significantly changed compared to those in normal rats. These results indicate that intestinal microbiota might play a key role in the oral pharmacokinetics of baicalin.