141 research outputs found

    Effect of Hydrogen on Pristine Amorphous V2O5 Thin Film

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    Sequentially deposited layer by layer up to five vanadium oxide film is deposited on glass and silica substrates at 300 k by vacuum thermal evaporation technique. The deposited samples subjected to reduction process in the preparation situe by hydrogen gas at 473k for 10 minutes and 573 k for 10, 20 minutes. The XRD investigation of the samples demonstrates that the pristine sample is amorphous while those reduced are crystalline. The existed phases in virgin samples are educated by Raman spectroscopy which indicates the single V2O5 phase. The different phases in the reduced sample are identified by analyzing their XRD patterns. The electrical resistance of the reduced samples is measured as a function of temperature during heating and cooling cycles. The transition temperature from semiconducting to metal state is defined by the derivative of dR/d

    Cripto-1 as a Potential Target of Cancer Stem Cells for Immunotherapy

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    Simple Summary Cancer immunotherapy is gaining attention as a potential fourth treatment following surgery, chemotherapy, and radiation therapy. Cancer stem cells have recently been recognized and validated as a key target for cancer treatment. Cripto-1, which is a GPI-anchored membrane-bound protein that functions as a co-receptor of Nodal, is a marker of cancer stem cells. Since Nodal is a member of the TGF-beta family, which performs an important role in stem cells and cancer stem cells, the inhibition of Cripto-1 could be a strategy by which to block Nodal signaling and thereby suppress cancer stem cells. We propose that Cripto-1 may be a novel target for cancer immunotherapy. The immune system has been found to be suppressed in cancer patients. Cancer cells are extremely resistant to chemotherapeutic drugs, conventional immunotherapy, or cancer antigen vaccine therapy. Cancer immunotherapy, which is mainly based on immune checkpoint inhibitors, such as those for PD-1, PD-L1, and CTLA4, is an effective treatment method. However, no immunotherapeutic target has been found that retains validity in the face of tumor diversity. The transforming growth factor (TGF)-beta cytokine family possesses broad biological activity and is involved in the induction and/or transdifferentiation of helper T cells, which are important in immunotherapy. Nodal is a member of the TGF-beta family playing important roles in tissue stem cells and cancer stem cells (CSCs), interacting with the co-receptor Cripto-1, as well as with Activin type IB (Alk4) and Activin typeIIreceptors, and maintaining stemness and Notch and Wnt/beta-catenin signaling in CSCs. In recent years, it has been reported that Cripto-1 could be a potential therapeutic target in CSCs. Here, we review the accumulated literature on the molecular mechanisms by which Cripto-1 functions in CSCs and discuss the potential of Cripto-1 as an immunotherapeutic target in CSCs

    New ZnO-based glass ceramic sensor for H2 and NO2 detection

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    In this study, a glass ceramic with a nominal composition 58ZnO:4Bi2O3:4WO3:33.3B2O3 was synthesized by melt quenching technique. A gas sensor was then manufactured using a ZnO sol-gel phase as a permanent binder of the glass–ceramic to an alumina substrate having interdigitated electrodes. The film sensitivity towards humidity, NH3, H2 and NO2 was studied at different temperatures. X-ray diffraction technique (XRD), field emission- scanning electron microscopy (FE-SEM) and differential thermal analysis (DTA) were used to characterize the prepared material. Though the response in the sub-ppm NO2 concentration range was not explored, the observed results are comparable with the latest found in the literature

    Temperature dependence growth of CdO thin film prepared by spray pyrolysis

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    AbstractCdO thin films prepared by spray pyrolysis technique show temperature dependence growth when the spray time is constant. In contrast, the growth is film thickness dependent when the substrate temperature is constant. The films are polycrystalline in the covered spray time and substrate temperature ranges. The crystallite size and microstrain are calculated and analyzed. The Atomic Force Microscopy (AFM) micrographs prove that the grains are uniformly distributed within the scanning areas (5μm×5μm) and (50μm×50μm). The roughness shows a considerable decrease with substrate temperature. All samples show an abrupt change in transmission which indicates a direct transition and good crystallinity. The transmission of films is increased up to 80% with increasing substrate temperature in wavelength ranged from 450nm to 1000nm. Also, a broad absorption band is observed in the range 1500–2000nm. This band could be attributed to the increase in free carrier concentration which confirmed by a reasonable decrease in the film sheet resistance. The band gap Eg is determined and found to be in the range 2.45–2.55eV. The sheet resistance is reduced with increasing deposition temperature due to the increase in free carrier concentration and found to be 66Ω/□ at 450°C

    Metastasis Model of Cancer Stem Cell-Derived Tumors

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    Metastasis includes the dissemination of cancer cells from a malignant tumor and seed in distant sites inside the body forming secondary tumors. Metastatic cells from the primary tumor can move even before the cancer is detected. Therefore, metastases are responsible for more than 90% of cancer-related deaths. Over recent decades there has been adequate evidence suggesting the existence of CSCs with self-renewing and drug-resistant potency within heterogeneous tumors. Cancer stem cells (CSCs) act as a tumor initiating cells and have roles in tumor retrieve and metastasis. Our group recently developed a unique CSC model from mouse induced pluripotent stem cells cultured in the presence of cancer cell-conditioned medium that mimics tumors microenvironment. Using this model, we demonstrated a new method for studying metastasis by intraperitoneal transplantation of tumors and investigate the metastasis ability of cells from these segments. First of all, CSCs were injected subcutaneously in nude mice. The developed malignant tumors were minimized then transplanted into the peritoneal cavity. Following this, the developed tumor in addition to lung, pancreas and liver were then excised and analyzed. Our method showed the metastatic potential of CSCs with the ability of disseminated and moving to blood circulation and seeding in distant organs such as lung and pancreas. This method could provide a good model to study the mechanisms of metastasis according to CSC theory

    Lipid profile improving effect of Coriandrum sativum seed extract in rats

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    Background: Hyperlipidaemia is a common disease in middle-aged and elderly people. It has received attention, as it indirectly affects the normal metabolism, blood viscosity and vital organ functions. It is a risk factor for cardiovascular and cerebrovascular diseases. Therefore, the aim of the present study was to evaluate the possible antihyperlipidemic effect of Coriander sativum seed extract (CSSE) in rats fed on high-fat diet.Methods: A parallel study design was adopted on 42 albino rats, divided randomly into 7 groups with different treatments. After a 6 week-experimental course, blood samples were collected and analysed for lipid and organ function parameters. Phytochemical analysis was conducted on the used seed extract to detect the active principles underlying its effects.Results: CSSE (150 and 300 mg/kg, orally, once daily) along with a high-fat (1.5% cholesterol+1.5% coconut oil, in diet) diet resulted in a significant (p≤0.05) improvement in plasma lipid parameters, including, total cholesterol, triacyglycerols and lipoproteins, compared to the high-fat group. group. The extract significantly (p≤0.05) improved hepatic (total proteins, albumin, globulins, total conjugated and unconjugated bilirubins, AST, ALT, GGT), cardiac (CK-MB and troponin-I) and renal (urea, creatinine & uric acid) biomarkers. Phytoanalysis of CSSE revealed presence of phlobatannin and flavonoids. The protection % produced by small and large doses of CSSE were dose-dependent and parallel to those of the standard antihyperlipidemic rosuvastatin (2 mg/dl orally, daily).Conclusions: These data indicate that CSSE has a marked antihyperlipidemic effect and could be a source for a promising nutraceutical antihyperlipidemic drug depending on its high phenolic and flavonoid content

    Revisiting Cancer Stem Cells as the Origin of Cancer-Associated Cells in the Tumor Microenvironment: A Hypothetical View from the Potential of iPSCs

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    The tumor microenvironment (TME) has an essential role in tumor initiation and development. Tumor cells are considered to actively create their microenvironment during tumorigenesis and tumor development. The TME contains multiple types of stromal cells, cancer-associated fibroblasts (CAFs), Tumor endothelial cells (TECs), tumor-associated adipocytes (TAAs), tumor-associated macrophages (TAMs) and others. These cells work together and with the extracellular matrix (ECM) and many other factors to coordinately contribute to tumor growth and maintenance. Although the types and functions of TME cells are well understood, the origin of these cells is still obscure. Many scientists have tried to demonstrate the origin of these cells. Some researchers postulated that TME cells originated from surrounding normal tissues, and others demonstrated that the origin is cancer cells. Recent evidence demonstrates that cancer stem cells (CSCs) have differentiation abilities to generate the original lineage cells for promoting tumor growth and metastasis. The differentiation of CSCs into tumor stromal cells provides a new dimension that explains tumor heterogeneity. Using induced pluripotent stem cells (iPSCs), our group postulates that CSCs could be one of the key sources of CAFs, TECs, TAAs, and TAMs as well as the descendants, which support the self-renewal potential of the cells and exhibit heterogeneity. In this review, we summarize TME components, their interactions within the TME and their insight into cancer therapy. Especially, we focus on the TME cells and their possible origin and also discuss the multi-lineage differentiation potentials of CSCs exploiting iPSCs to create a society of cells in cancer tissues including TME

    Influence of Reaction Time, Reducing Agent and Zinc Precursors on the Morphological Structures of Zinc Oxide

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    ZnO either nanoparticles or nanorods were synthesized via sol-gel technique. Many factors were studied and optimized in order to obtain different morphological structures of nano-ZnO. Effect of reaction time (3, 6, 12, 24 and 48 hours) has been studied to optimize the best preparation condition. Reducing agent (NH3, NaOH and KOH) is one of the factors affect on morphological structures, which has been studied in this work. Other effect has been studied in this work is zinc precursors such as Zn(NO3)2, ZnAc2, ZnCl2, and ZnBr2. The morphological structures of prepared ZnO were revealed using scanning electron microscope (SEM) and the aspect ratios were calculated. x-ray diffraction (XRD) patternsexposed a highly crystallized wurtzite structure and used for identifying phase structure and chemical state of ZnO under different preparation conditions.Keywords: sol-gel, morphological structures, reducing agent, SEM, preparation conditions

    Paclitaxel-Based Chemotherapy Targeting Cancer Stem Cells from Mono- to Combination Therapy

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    Paclitaxel (PTX) is a chemotherapeutical agent commonly used to treat several kinds of cancer. PTX is known as a microtubule-targeting agent with a primary molecular mechanism that disrupts the dynamics of microtubules and induces mitotic arrest and cell death. Simultaneously, other mechanisms have been evaluated in many studies. Since the anticancer activity of PTX was discovered, it has been used to treat many cancer patients and has become one of the most extensively used anticancer drugs. Regrettably, the resistance of cancer to PTX is considered an extensive obstacle in clinical applications and is one of the major causes of death correlated with treatment failure. Therefore, the combination of PTX with other drugs could lead to efficient therapeutic strategies. Here, we summarize the mechanisms of PTX, and the current studies focusing on PTX and review promising combinations
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