The highly sensitive impedimetric biosensor in label free approach for hepatitis B virus DNA (HPV DNA) detection based on tellurium doped ZnO nanowires was fabricated. The NWs were grown by hybrid thin film oxidation in the physical vapor deposition (PVD) mechanism. The morphology characterization of the synthesized NWs was performed by field emission scanning electron microscopy (FESEM) and the images demonstrated that the diameter and the length of the materialized NWs were around 50 nm and several micrometers, respectively. The high-resolution transmission electron microscopy (HRTEM) image indicated that the fabricated NWs were crystalline and their phase characterization was validated by the X-ray diffraction pattern (XRD pattern). The single-stranded DNA (ss DNA) probe was immobilized on the surface of the Te-ZnO NWs. The electrochemical impedance spectra (EIS) measurements showed high response sensitivity after hybridization with complementary oligonucleotides. The biosensor could distinguish complementary target from non-complementary and mismatch oligonucleotides. The HBV biosensor could respond to complementary target in the concentrations range from 1 pM to 1 μM. The limit of detection (LOD) of the biosensor was 0.1 pM. The stability of the HBV DNA biosensor was investigated and biosensor could show 95% of its initial responses after 8 weeks maintenance.
Cucumber (Cucumis sativus L.), a popular vegetable crop of the family Cucurbitaceae, is cultivated in different parts of the world and is of great economic importance. Ultrasound is known as a physical stimulus that can affect living systems. At the right frequency and exposure period, these waves have desired effects. In the present study, 2-week-old plants, were put in an ultrasonic bath with a nominal frequency of 40 kHz, a central frequency of 34/722 kHz and a bandwidth of 320 Hz for 0, 5, 10 and 15 minutes. Hypocotyl pieces were used as explants and cultured in Murashige and Skoog medium supplemented with 0/5 mg/l each of 2,4-dichlorophenoxyacetic acid, 1-Naphthalene acetic acid, kinetin and 6-benzylaminopurine. The use of ultrasonication at a nominal frequency of 40 kHz for 10 minutes showed better results as compared with the samples treated for 0, 5 and 15 minutes, in terms of the shape, maturity of the embryos, and also the germination of artificial seeds and maturing to flowering stage. Since the cucumber of Esfahan is very famous for its aroma and taste and it is somewhat at risk of extinction, we studied the production of artificial seeds of this valuable plant using somatic embryos and apical buds. This research is the first report on investigation of the positive effect of ultrasound on somatic embryogenesis and artificial seed production. our results clearly showed that this method is a practical method to accelerate seed germination and flowering stage.
Cota tinctoria is a medicinal plant which has been used for management of cancer in folk medicine of various regions. The aim of present study is to investigate cytotoxic activity of different concentrations of hydroalcoholic extract of C. tinctoria flowers on gastric (AGS) and liver (Hep-G2) cancer cell lines as well as Human Natural GUM fibroblast (HUGU) cells. Cell mortality rates were examined after 24, 48 and 72 h incubations using the MTT assay. IC50 of extract on AGS cells after 24, 48 and 72h was 1.46, 1.29 and 1.14 µg/mL respectively. The extract demonstrated IC50 of 5.15, 3.92 and 2.89 µg/mL on Hep-G2 cells after 24, 48 and 72 h respectively. No cytotoxic effect was detected on HUGU (Human Natural GUM fibroblast) cells. C. tinctoria seems to have a promising potential to be considered as a source for anticancer drug discovery. However, more experimental and clinical studies are required.
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