1,702 research outputs found
Chemical Composition of Salvia plebeian R.Br. Essential Oil and its Larvicidal Activity against Aedes aegypti L
Purpose: To evaluate the larvicidal activity of the essential oil of Salvia plebeian R.Br. (Labiatae) aerial parts against the larvae of Aedes aegypti L.Methods: The essential oil of S. plebeian aerial parts was obtained by hydro-distillation and analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The essential oil was evaluated for larvicidal activity using World Health Organization (WHO) procedures, against the fourth larvae of A. aegypti within 24 h, and activity was recorded for various concentrations of the ranging from 12.5 – 200.0 μg/mL.Results: A total of 33 components of the essential oil of S. plebeian were identified. The major compounds of the essential oil were caryophyllene oxide (15.54 %), γ-eudesmol (14.03 %), τ-cadinol (10.21 %), calamenene (9.63 %), copaene (5.70 %), γ-cadinene (5.30 %), cadalene (5.28 %), α- muurolene (5.19 %), ledol (5.14 %) and α-cadinol (5.08 %). The essential oil exhibited larvicidal activity against A. aegypti at a median lethal concentration (LC50) of 46.26 μg/mL.Conclusion: The findings indicate that the essential oil of S. plebeian aerial parts has potentials for use in the control of A. aegypti larvae and may be useful in the search for newer, safer and more effective natural compounds as larvicides.Keywords: Salvia plebeian, Essential oil, Larvicidal activity, Aedes aegypti, Caryophyllene oxide, γ- Eudesmol, τ-Cadinol, Calamenen
Effects of vitrification and post-thawing interval on the cytoskeleton and subsequent fertilization rate of in vitro derived bovine oocytes
Vitrification may alter the cytoskeleton (microtubule, meiotic spindle, microfilament, etc.) and the subsequent fertilization rate of in vitro derived bovine oocytes. This study was conducted to evaluate the effect of vitrification and post-thawing incubation periods on the cytoskeleton and fertilization rate of in vitro matured (IVM) bovine oocytes. Following 22 h of IVM, 184 fresh matured oocytes (MO) were immediately fertilized in vitro and served as a control. The remaining MO (1009) were then vitrified by the solid surface vitrification method. Immediately after thawing, MO were incubated in maturation medium in 5% CO2 at 39 °C for 0, 30, 60, 90 and 120 min respectively. Following incubation, half of the MO from each vitrified-thawed treatment group (0, 30, 60, 90, and 120 min) was stained with fluorescein isothiocyanate conjugated (FITC) and propidium iodide (PI) to evaluate the microtubule and DNA or spindle under laser-scanning confocal microscopy. The remaining half from the vitrified-thawed MO treatment groups was washed three times in Brackett and Oliphant\'s fertilization medium and in vitro fertilized. Cleavage and blastocyst rates were recorded 48 h post-fertilization. Results demonstrated that vitrification damaged MO zona pellucida (ZP), microtubule (MT), meiotic spindle (MS), and caused chromosomal fragmentation. Both the cleavage (84%) and blastocyst rates (50%) of the control group were significantly higher compared to the vitrified-thawed treatment groups. However, extending the incubation period of vitrified MO to 120 min after thawing (prior to fertilization) improved cleavage (65%) and blastocyst (13%) rates 48 h post-fertilization. Fertilizing vitrified MO immediately (0 min group) after thawing resulted in the lowest cleavage (42%) and blastocyst (1.9%) rates. In conclusion, vitrification reduces the subsequent fertilization rate of MO, however, a prolonged post-thawing incubation period (120 min) improves survival, cleavage and blastocyst formation rates, and enhances the reorganization of MO\'s cytoskeleton (MT and MS). Keywords: Vitrification; cytoskeleton; bovine; oocytes; fertilization; in vitro matured South African Journal of Animal Science Vol. 36 (5) 2006: pp.42-4
Analysis of critical risk factors for ppp sewage treatment projects based on a sewage treatment project in quanzhou
2008-2009 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe
In Situ Synthesis of Reduced Graphene Oxide and Gold Nanocomposites for Nanoelectronics and Biosensing
In this study, an in situ chemical synthesis approach has been developed to prepare graphene–Au nanocomposites from chemically reduced graphene oxide (rGO) in aqueous media. UV–Vis absorption, atomic force microscopy, scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy were used to demonstrate the successful attachment of Au nanoparticles to graphene sheets. Configured as field-effect transistors (FETs), the as-synthesized single-layered rGO-Au nanocomposites exhibit higher hole mobility and conductance when compared to the rGO sheets, promising its applications in nanoelectronics. Furthermore, we demonstrate that the rGO-Au FETs are able to label-freely detect DNA hybridization with high sensitivity, indicating its potentials in nanoelectronic biosensing
Recent changes of water discharge and sediment load in the Yellow River basin, China
The Yellow River basin contributes approximately 6% of the sediment load from all river systems globally, and the annual runoff directly supports 12% of the Chinese population. As a result, describing and understanding recent variations of water discharge and sediment load under global change scenarios are of considerable importance. The present study considers the annual hydrologic series of the water discharge and sediment load of the Yellow River basin obtained from 15 gauging stations (10 mainstream, 5 tributaries). The Mann-Kendall test method was adopted to detect both gradual and abrupt change of hydrological series since the 1950s. With the exception of the area draining to the Upper Tangnaihai station, results indicate that both water discharge and sediment load have decreased significantly (p<0.05). The declining trend is greater with distance downstream, and drainage area has a significant positive effect on the rate of decline. It is suggested that the abrupt change of the water discharge from the late 1980s to the early 1990s arose from human extraction, and that the abrupt change in sediment load was linked to disturbance from reservoir construction.Geography, PhysicalGeosciences, MultidisciplinarySCI(E)43ARTICLE4541-5613
Thermal Contraction of Electrodeposited Bi/BiSb Superlattice Nanowires
The lattice parameter of Bi/BiSb superlattice nanowire (SLNW) has been measured using in situ high-temperature X-ray diffraction method. The single crystalline Bi/BiSb SLNW arrays with different bilayer thicknesses have been fabricated within the porous anodic alumina membranes (AAMs) by a charge-controlled pulse electrodeposition. Different temperature dependences of the lattice parameter and thermal expansion coefficient were found for the SLNWs. It was found that the thermal expansion coefficient of the SLNWs with a large bilayer thickness has weak temperature dependence, and the interface stress and defect are the main factors responsible for the thermal contraction of the SLNWs
Tumor-suppressor activity of RRIG1 in breast cancer
<p>Abstract</p> <p>Background</p> <p>Retinoid receptor-induced gene-1 (RRIG1) is a novel gene that has been lost in several types of human cancers. The aim of this study was to determine whether RRIG1 plays a role in breast cancer, such as in the suppression of breast cancer cell growth and invasion.</p> <p>Methods</p> <p>Immunohistochemistry was used to detect RRIG1 expression in breast tissue specimens. Gene transfection was used to restore or knock down RRIG1 expression in breast cancer cell lines for analysis of cell viability, colony formation, and migration/invasion potential. Reverse-transcription polymerase chain reaction and western blot assays were used to detect the changes in gene expression. The RhoA activation assay was used to assess RRIG1-induced inhibition of RhoA activity.</p> <p>Results</p> <p>The immunohistochemical data showed that <it>RRIG1 </it>expression was reduced in breast cancer tissues compared with normal and atypical hyperplastic breast tissues. <it>RRIG1 </it>expression was inversely correlated with lymph node metastasis of breast cancer but was not associated with the status of hormone receptors, such as estrogen receptor, progesterone receptor, or HER2. Furthermore, restoration of <it>RRIG1 </it>expression inhibited proliferation, colony formation, migration, and invasion of breast cancer cells. Expression of RRIG1 also reduced phosphorylated Erk1/2 and Akt levels; c-Jun, MMP9, and Akt expressions; and RhoA activity. In contrast, knockdown of RRIG1 expression promoted breast cancer cell proliferation, colony formation, migration, and invasion potential.</p> <p>Conclusion</p> <p>The data from the current study indicated that <it>RRIG1 </it>expression was reduced or lost in breast cancer and that restoration of RRIG1 expression suppressed breast cancer cell growth and invasion capacity. Future studies will determine the underlying molecular mechanisms and define RRIG1 as a tumor-suppressor gene in breast cancer.</p
Expression of nuclear retinoid receptors in normal, premalignant and malignant gastric tissues determined by in situ hybridization
[[abstract]]Retinoids exhibit multiple functions through interaction with nuclear retinoid receptors and have growth-suppressive activity on gastric cancer cells. To better understand the roles of nuclear retinoid receptors during gastric carcinogenesis, we have used in situ hybridization to investigate expression of retinoic acid receptors (RARs) and retinoid x receptors (RXRs) in premalignant and malignant formalin-fixed paraffin-embedded gastric tissues. Histological sections of eight normal, 17 distal normal and nine gastric cancer tissues were hybridized with non-radioactive RNA probes for subtypes of RAR and RXR. Expression of RARα, RARβ, RARγ, RXRα and RXRβ was found in most cell types in gastric mucosa tissues from normal individuals as well as in distal normal tissues from cancer patients. Expression of RARα and RARβ were found in three and seven cancer tissues, respectively, and levels of RXRα mRNA were significantly decreased in poorly differentiated cancer tissues. Among the five investigated nuclear retinoid receptors, only expression of RARα mRNA was significantly decreased in intestinal metaplasia, dysplasia and cancer tissues when compared to adjacent normal tissues. In conclusion, normal gastric mucosa expressed both RARs and RXRs, which supports the physiological role of retinoic acid on normal gastric mucosa. The decrease in RARα expression in premalignant and malignant gastric tissues suggests a significant role of RARα during gastric carcinogenesis.[[notice]]補正完畢[[incitationindex]]SC
CXCL10/CXCR3 signaling mobilized-regulatory T cells promote liver tumor recurrence after transplantation
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