Application of Renewable Kenaf Cellulose Nanofiber as a Temephos Nanocarrier for Control of Aedes Aegypti (Diptera: Culicidae) Larvae

2021 ◽  
Author(s):  
Hazirah binti Pengiran ◽  
Jahangir Kamaldin ◽  
Leo Bey Fen ◽  
Hamdan Ahmad
Keyword(s):  
Aedes Aegypti ◽  
High Performance ◽  
Control Method ◽  
Cellulose Nanofiber ◽  
Effective Control ◽  
Mosquito Larvae ◽  
Renewable Source ◽  
Transmission Electron ◽  
Materials Used ◽  
Microscopy Examination

Abstract Larviciding is an effective control method in managing mosquito-borne diseases. However, current carrier materials used in larvicides formulation raised environmental concerns due to its non-renewable origin. Herein, our study aimed to evaluate the application of the renewable source kenaf cellulose nanofiber (KCNF) impregnated with temephos for the control of Aedes aegypti mosquito larvae. The morphology of KCNF+T was examined using field emission scanning electron microscope (FESEM) and transmission electron microscopy (TEM) while the quantity of temephos impregnated, released, and retained on the fibers upon dispersion in water were determined using high performance liquid chromatography (HPLC). Subsequently, the bioefficacy of the KCNF+T was evaluated against Ae. aegypti larvae. The FESEM and TEM micrograph verified the presence of temephos on the KCNF after the impregnation. HPLC analysis showed the amount of temephos impregnated on KCNF was 97 % of the 0.1 mg temephos. Upon dispersion in water, KCNF+T released 53% temephos and the retention of temephos on KCNF+T gradually decreased to 30, 17 and 7 % on the first, third and fifth month, respectively. The exposure of Ae. aegypti larvae to KCNF+T at concentration 0.006 to 0.01 mg/L was effective at 17 - 25 folds in killing Ae. aegypti larvae compared to temephos without KCNF. Microscopy examination revealed accumulation of the KCNF on the larval appendages. Overall, our study demonstrated that KCNF made from renewable source is an effective nanocarrier of temephos for the control of Ae. aegypti mosquito larvae.

Antiparasitic effect of calcium and magnesium ion-free buffer treatments against a common monogeneanNeobenedenia girellae

Parasitology ◽  
2006 ◽  
Vol 134 (2) ◽  
pp. 229-236 ◽  
Author(s):  
H. OHASHI ◽  
N. UMEDA ◽  
N. HIRAZAWA ◽  
Y. OZAKI ◽  
C. MIURA ◽  
...  
Keyword(s):  
Control Method ◽  
Intercellular Junctions ◽  
Effective Control ◽  
Metallic Ions ◽  
Electron Microscopic ◽  
Percentage Survival ◽  
Transmission Electron ◽  
Spotted Halibut

This study investigated a new effective method for controlling the capsalid monogeneanNeobenedenia girellae. We examinedin vitroandin vivothe effect on the percentage survival ofN. girellaein buffers containing different metallic ions. Decreased survival was observed in buffer solutions lacking two ions. In particular, the percentage survival ofN. girellaewas significantly decreased after 10 min exposure to buffer containing neither Ca2+nor Mg2+. Transmission electron microscopic observations showed that treatment with this buffer disrupted intercellular junctions. This significant effect on percentage survival ofN. girellaeusing Ca2+/Mg2+-free buffer was confirmed in anin vivoassay. Ca2+/Mg2+-free buffer had no effect on the condition of the host, spotted halibutVerasper variegates(Pleuronectidae). These results suggest that treatment with Ca2+/Mg2+-free buffer is a new effective control method, which could replace existing control methods.

scholarly journals Significantly enhancement of sunlight photocatalytic performance of ZnO by doping with transition metal oxides

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alfonso E. Ramírez ◽  
Marly Montero-Muñoz ◽  
Lizbeth L. López ◽  
J. E. Ramos-Ibarra ◽  
Jose A. H. Coaquira ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Transition Metal ◽  
Metal Oxides ◽  
Transition Metal Oxides ◽  
High Performance ◽  
Photocatalytic Performance ◽  
Adsorption Sites ◽  
Surface Areas ◽  
Transmission Electron ◽  
Materials Used

AbstractIn this study we report, the synthesis of ZnO and its doping with Transition Metal Oxides -TMO-, such as Cr2O3, MnO2, FeO, CoO, NiO, Cu2O and CuO. Various characterization techniques were employed to investigate the structural properties. The X-ray diffraction (XRD) data and Rietveld refinement confirmed the presence of TMO phases and that the ZnO structure was not affected by the doping with TMO which was corroborated using transmission Electron microscopy (TEM). Surface areas were low due to blockage of adsorption sites by particle aggregation. TMO doping concentration in the range of 3.7–5.1% was important to calculate the catalytic activity. The UV–Visible spectra showed the variation in the band gap of TMO/ZnO ranging from 3.45 to 2.46 eV. The surface catalyzed decomposition of H2O2 was used as the model reaction to examine the photocatalytic activity following the oxygen production and the systems were compared to bulk ZnO and commercial TiO2-degussa (Aeroxyde-P25). The results indicate that the introduction of TMO species increase significantly the photocatalytic activity. The sunlight photocatalytic performance in ZnO-doped was greater than bulk-ZnO and in the case of MnO2, CoO, Cu2O and CuO surpasses TiO2 (P25-Degussa). This report opens up a new pathway to the design of high-performance materials used in photocatalytic degradation under visible light irradiation.

scholarly journals Larvicidal Activity of Isoflavonoids from Muellera Frutescens Extracts Against Aedes Aegypti

2012 ◽  
Vol 7 (10) ◽  
pp. 1934578X1200701
Author(s):  
Charlotte Nirma ◽  
Alice M S. Rodrigues ◽  
Charlie Basset ◽  
Lionel Chevolot ◽  
Romain Girod ◽  
...  
Keyword(s):  
Biological Activity ◽  
Aedes Aegypti ◽  
Larvicidal Activity ◽  
Environmentally Friendly ◽  
Bark Extract ◽  
Mosquito Larvae ◽  
Toxic Activity ◽  
Renewable Source ◽  
Environmentally Safe ◽  
Hexane Extracts

The biological activity of extracts from the leaves, bark and roots of Muellera frutescens, an Amazonian ichtyotoxic plant, were evaluated to find new environmentally safe insecticides. The n-hexane extracts of bark, leaf, and root showed a strong toxic activity against Aedes aegypti mosquito larvae. Bioguided fractionation of the bark extract led to the isolation of seven isoflavonoids (12a-hydroxyelliptone, elliptone, (-)-variabilin, rotenone, rotenolone, tephrosin and deguelin). Rotenone and deguelin are responsible for the larvicidal activity of the plant. M. frutescens leaves contain up to 0.6%, w/w, deguelin. These results justify the traditional ichtyotoxic use of M. frutescens. The leaves contain a relatively high proportion of deguelin and, therefore, can be considered as a renewable source of this environmentally friendly insecticidal isoflavonoid.

scholarly journals SEMI-FIELD EVALUATION OF ULTRA-LOW VOLUME (ULV) GROUND SPRAY OF AQUALUER ® 20-20 AGAINST IRRADIATED AEDES AEGYPTI

2021 ◽  
Vol 68 (1) ◽  
pp. 63-69
Author(s):  
Vindhya S. Aryaprema
Keyword(s):  
Aedes Aegypti ◽  
Chemical Control ◽  
Control Method ◽  
Field Evaluation ◽  
Effective Control ◽  
Spray Application ◽  
Pyrethroid Insecticides ◽  
Host Seeking ◽  
Vector Management ◽  
Low Volume

Sterile insect technique (SIT) using irradiated mosquitoes is an effective control method capable of being assimilated into integrated vector management (IVM) programs. Chemical control of mosquitoes using ultra-low volume (ULV) spray applications of pyrethroid and organophosphate insecticides is already an essential component of IVM programs. Prior to their release in nature, irradiation of mosquitoes for SIT use can significantly impact the mosquito’s biology, specifically its host-seeking and feeding behavior. Little is known about how radiation exposure might impact a mosquito’s susceptibility to pyrethroid insecticides. The present study was carried out to evaluate the influence of Aqualuer ® 20-20 ULV applications on irradiated Aedes aegypti. Caged mosquito trials indicated that both male and female irradiated Ae. aegypti were as susceptible as their non-irradiated counterparts of the same population to Aqualuer 20-20 ULV application, with the highest mean percent mortalities achieved at the first 24h post-treatment period at both 30.5 m and 61 m downwind of the spray application path.

High Voltage Transmission Microscopy of Surveyor III Camera Shrouds

1971 ◽  
Vol 29 ◽  
pp. 138-139
Author(s):  
W. R. Duff ◽  
L. E. Thomas ◽  
R. M. Fisher ◽  
S. V. Radcliffe
Keyword(s):  
Alloy Sheet ◽  
Transmission Microscopy ◽  
Television Camera ◽  
Window Method ◽  
Transmission Electron ◽  
Microstructural Effects ◽  
Lunar Environment ◽  
Successful Retrieval ◽  
Materials Used ◽  
Abrasive Paper

Successful retrieval of the television camera and other components from the Surveyor III spacecraft by the Apollo 12 astronauts has provided a unique opportunity to study the effects of a known and relatively extensive exposure to the lunar environment. Microstructural effects including those produced by micro-meteorite impact, radiation damage (by both the solar wind and cosmic rays) and solar heating might be expected in the materials used to fabricate the spacecraft. Samples received were in the form of 1 cm2 of painted unpainted aluminum alloy sheet from the top of the camera visor (JPL Code 933) and the sides (935,936) and bottom (934) of the lower camera shroud. They were prepared for transmission electron microscopy by first hand-grinding with abrasive paper to a thickness of 0.006". The edges were lacquered and the sample electropolished in 10% perchloric methanol using the “window” method, to a thickness of ~0.001". Final thinning was accomplished by polishing 3 mm punched disks in an acetic-phosphoric-nitric acid solution.

Prospects for convergent beam electron diffraction with a 200kV cold field-emission transmission electron microscope

1991 ◽  
Vol 49 ◽  
pp. 466-467
Author(s):  
J W Steeds ◽  
R Vincent
Keyword(s):  
Field Emission ◽  
High Performance ◽  
Small Diameter ◽  
Convergent Beam Electron Diffraction ◽  
Zone Axis ◽  
Medium Voltage ◽  
Transmission Electron ◽  
Good Crystallinity ◽  
Special Modification ◽  
Convergent Beam

We review the analytical powers which will become more widely available as medium voltage (200-300kV) TEMs with facilities for CBED on a nanometre scale come onto the market. Of course, high performance cold field emission STEMs have now been in operation for about twenty years, but it is only in relatively few laboratories that special modification has permitted the performance of CBED experiments. Most notable amongst these pioneering projects is the work in Arizona by Cowley and Spence and, more recently, that in Cambridge by Rodenburg and McMullan.There are a large number of potential advantages of a high intensity, small diameter, focussed probe. We discuss first the advantages for probes larger than the projected unit cell of the crystal under investigation. In this situation we are able to perform CBED on local regions of good crystallinity. Zone axis patterns often contain information which is very sensitive to thickness changes as small as 5nm. In conventional CBED, with a lOnm source, it is very likely that the information will be degraded by thickness averaging within the illuminated area.

Scanning and Transmission Electron Microscopy of the Endometrium in Women with Ovarian Dysgenesis (Turner'S Syndrome)

1976 ◽  
Vol 34 ◽  
pp. 148-149
Author(s):  
A. González-Angulo ◽  
S. Armendares-Sagrera ◽  
I. Ruíz de Chávez ◽  
H. Marquez-Monter ◽  
R. Aznar
Keyword(s):  
Surface Epithelium ◽  
Secretory Cells ◽  
Turner's Syndrome ◽  
Ciliated Cells ◽  
Turner’S Syndrome ◽  
Exogenous Hormone ◽  
Ovarian Dysgenesis ◽  
Transmission Electron ◽  
Normal Women ◽  
Microscopy Examination

It is a well documented fact that endometrial hyperplasia and adenocarcinoma may develop in women with Turner's syndrome who had received unopposed estrogen treatment (1), as well as in normal women under contraceptive medication with the sequential regime (2). The purpose of the present study was to characterize the possible changes in surface and glandular epithelium in these women who were treated with a sequential regime for a period of between three and eight years. The aim was to find organelle modifications which may lead to the understanding of the biology of an endometrium under exogenous hormone stimulation. Light microscopy examination of endometrial biopsies of nine patients disclosed a proliferative pattern; in two of these, there was focal hyperplasia. With the scanning electron microscope the surface epithelium in all biopsies showed secretory cells with microvilli alternating with non secretory ciliated cells. Regardless of the day of the cycle all biopsies disclosed a large number of secretory cells rich in microvilli (fig.l) with long and slender projections some of which were branching (fig. 2).

MXene/Cellulose Nanofiber-Foam Based High Performance Degradable Piezoresistive Sensor with Greatly Expanded Interlayer Distances

Nano Energy ◽  
2021 ◽  
pp. 106151
Author(s):  
Tuoyi Su ◽  
Nishuang Liu ◽  
Yihua Gao ◽  
Dandan Lei ◽  
Luoxin Wang ◽  
...  
Keyword(s):  
High Performance ◽  
Cellulose Nanofiber ◽  
Piezoresistive Sensor

scholarly journals Novel Carbon Dots Derived from Glycyrrhizae Radix et Rhizoma and Their Anti-Gastric Ulcer Effect

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1512
Author(s):  
Yuhan Liu ◽  
Meiling Zhang ◽  
Jinjun Cheng ◽  
Yue Zhang ◽  
Hui Kong ◽  
...  
Keyword(s):  
Gastric Ulcer ◽  
Photoelectron Spectroscopy ◽  
Carbon Dots ◽  
High Performance ◽  
Raw264.7 Cells ◽  
Mice Model ◽  
X Ray ◽  
Glycyrrhizae Radix ◽  
Transmission Electron ◽  
High Resolution Tem

Glycyrrhizae Radix et Rhizoma (GRR) is one of the commonly used traditional Chinese medicines in clinical practice, which has been applied to treat digestive system diseases for hundreds of years. GRR is preferred for anti-gastric ulcer, however, the main active compounds are still unknown. In this study, GRR was used as precursor to synthesize carbon dots (CDs) by a environment-friendly one-step pyrolysis process. GRR-CDs were characterized by using transmission electron microscopy, high-resolution TEM, fourier transform infrared, ultraviolet-visible and fluorescence spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction and high-performance liquid chromatography. In addition, cellular toxicity of GRR-CDs was studied by using CCK-8 in RAW264.7 cells, and the anti-gastric ulcer activity was evaluated and confirmed using mice model of acute alcoholic gastric ulcer. The experiment confirmed that GRR-CDs were the spherical structure with a large number of active groups on the surface and their particle size ranged from 2 to 10 nm. GRR-CDs had no toxicity to RAW264.7 cells at concentration of 19.5 to 5000 μg/mL and could reduce the oxidative damage of gastric mucosa and tissues caused by alcohol, as demonstrated by restoring expression of malondialdehyde, superoxide dismutase and nitric oxide in serum and tissue of mice. The results indicated the explicit anti-ulcer activity of GRR-CDs, which provided a new insights for the research on effective material basis of GRR.

Sign in / Sign up

Export Citation Format

Share Document