scholarly journals Correlation Between Mosquito Repellent Protection Time And Insensible Water Loss From The Skin

1975 ◽  
Vol 65 (4) ◽  
pp. 385-387 ◽  
Author(s):  
Robert L. Rietschel ◽  
Thomas S. Spencer
Keyword(s):  
Water Loss ◽  
Mosquito Repellent ◽  
Protection Time

scholarly journals Preliminary Study of the Mosquito Repellent and Adulticidal Effects of Volatile Oils of Lemon grass (Cymbopogon winterianus) in Imo State, Southeast Nigeria

2020 ◽  
Vol 7 (01) ◽  
pp. 4726-4734
Author(s):  
Emmanuel Nwanya ◽  
Evangeline Tochi Oparaocha ◽  
Ikenna Emmanuel Okoroafor ◽  
Christopher Sule Oyamienlen
Keyword(s):  
Controlled Trial ◽  
Volatile Oil ◽  
Body Parts ◽  
Mosquito Repellent ◽  
Complete Protection ◽  
Volatile Oils ◽  
Protection Time ◽  
Lemon Grass ◽  
Biting Rate ◽  
Close Range

Lemon grass (Cymbopogon winteriatus) has been widely acclaimed to possess therapeutic, cosmetic and insecticidal activities. This study was conducted using a field controlled trial by human volunteers to confirm the effectiveness and applicability of locally-produced Lemon grass oil as a mosquito repellent and adulticidal agent for the prevention of mosquito-borne diseases in Nigeria. Volatile oil was extracted using petroleum ether as solvent while olive oil was used as oil base. The study was conducted between September and October 2017 and made use of 12 volunteers across three locations. The lotions were applied on exposed body parts of the volunteers and they worked three shifts daily. The biting rate, percentage repellence complete protection time and whole night protection were measured and recorded. Topical application of each lotion reduced the biting rate of mosquitoes across the three locations, with the 60% (v/v) exhibiting higher impact of 341 vs 32; 438 vs 44 and 388 vs 33.  The 60% (v/v) formulation also had the highest percentage repellence of 91.92% at Location I, offered a whole night protection against mosquito in location I and O and offered a Complete Protection Time (CPT) of 21.6, 18.93 and 20.8 respectively across all three locations. There was a significant statistical association r=0.95 (p<0.05) between concentrations of the Lemon grass oil formulations and mean duration protection time against mosquitoes. All formulation exhibited adulticidal activities, with the 60% (v/v) formulation having higher impact, causing fast immobilization or paralyzing effect on some mosquitoes that were at close range to treated volunteer’s body. The study concludes that volatile oils of Lemon grass possess mosquito (A. gambiae and An. funestus) repellent and adulticidal effects, especially at higher concentrations and can be used to reduce human-mosquito contacts and hence mosquito-borne diseases and irritation caused by their bites.

scholarly journals Electrospinning repellents in polyvinyl alcohol-nanofibres for obtaining mosquito-repelling fabrics

2019 ◽  
Vol 6 (8) ◽  
pp. 182139 ◽  
Author(s):  
Lucy Ciera ◽  
Lynda Beladjal ◽  
Lieve Van Landuyt ◽  
David Menger ◽  
Maarten Holdinga ◽  
...  
Keyword(s):  
Polyvinyl Alcohol ◽  
Tensile Properties ◽  
Slow Release ◽  
Textile Material ◽  
Mosquito Repellent ◽  
Associated Diseases ◽  
Protection Time ◽  
Short Period ◽  
Added Benefit ◽  
Significant Change

Recently, the use of repellents for preventing the transmission of mosquito-borne diseases is getting increasingly more attention. However, most of the current repellents are volatile in nature and must be frequently re-applied as their efficacy is only limited to a short period of time. Therefore, a slow release and abrasion-resistant mechanism is needed for prolonging the protection time of the repellents. The focus of this study is on the direct micro-encapsulation of repellents from an emulsion and integration of already encapsulated repellents into nanofibres via electrospinning. Different repellents were electrospun in polyvinyl alcohol (PVA) nanofibrous structures, namely p -menthane-3,8-diol micro-capsules, permethrin, chilli and catnip oil. The repellents were successfully incorporated in the nanofibres and the tensile properties of the resulting samples did not have a significant change. This means that the newly created textiles were identical to current PVA nanofibrous textiles with the added benefit of being mosquito repellent. Principally, all incorporated repellents in the nanofibrous structures showed a significantly reduced number of mosquito landings compared to the control. Consequently, the currently described method resulted in a new and very effective repelling textile material that can be used in the prevention against mosquito-associated diseases.

Influence of Human Skin Surface Lipids on Protection Time of Topical Mosquito Repellent

1977 ◽  
Vol 66 (12) ◽  
pp. 1764-1766 ◽  
Author(s):  
W.A. Skinner ◽  
H.C. Tong ◽  
H. Johnson ◽  
R.M. Parkhurst ◽  
D. Thomas ◽  
...  
Keyword(s):  
Human Skin ◽  
Skin Surface ◽  
Mosquito Repellent ◽  
Protection Time ◽  
Surface Lipids ◽  
Skin Surface Lipids

Electron Microscopy of Silicon Deposits in Foliar Idioblasts of Magnolia Grandiflora

1976 ◽  
Vol 34 ◽  
pp. 374-375
Author(s):  
Michael T. Postek
Keyword(s):  
Electron Microscopy ◽  
Water Loss ◽  
Normal Development ◽  
Magnolia Grandiflora ◽  
Plant Body ◽  
Normal Metabolism ◽  
Hydrated Oxide

Silicon occurs naturally in plants in the form of its hydrated oxide (SiO2.nH2O) commonly called silica. Silica has been shown to be a necessary element in the normal development of many plants, playing an array of roles including strengthening, protection, and reduction of water loss. Deposition of silica in various portions of the plant body, especially the leaves, may also be viewed as a way for the plant to dispose of any excess silica taken up beyond that necessary for normal metabolism.Studies of this “opaline” silica have thus far been limited to species of the Cyperaceae and Gramineae known to possess significant quantities of silica. Within the Magnoliaceae, certain “glistening” idioblast cells at the foliar veinlet termini and vein sheaths of Magnolia grandiflora (1) have been suspected to be siliceous in nature.

The examination of biophysical parameters of skin (transepidermal water loss, skin hydration and pH value) in different body regions of ponies

2012 ◽  
Vol 15 (3) ◽  
pp. 553-559 ◽  
Author(s):  
M.P. Szczepanik ◽  
P.M. Wilkołek ◽  
M. Pluta ◽  
Ł.R. Adamek ◽  
Z.J.H. Pomorski
Keyword(s):  
Water Loss ◽  
Ph Value ◽  
Neck Region ◽  
Transepidermal Water Loss ◽  
Skin Hydration ◽  
Lumbar Region ◽  
Biophysical Parameters ◽  
Body Regions ◽  
Skin Ph

Abstract The purpose of this study was to evaluate transepidermal water loss, skin hydration and skin pH in normal ponies. Sixteen ponies of both sexes were examined in the study. Measurements were taken from seven different sites: the neck region, the shoulder, thorax, lumbar, inguinal, lip region and the auricle. In each of the regions transepidermal water loss (TEWL), skin hydration and skin pH were measured. For transepidermal water loss, the lowest values were observed in the lumbar region (9.71g/hm2), while the highest values were observed in the lip region (22.35 g/hm2). In the case of skin hydration the lowest values were observed for the thorax region (2.13 CU), and the highest for the lip region (41.81 CU). For skin pH, the lowest results were obtained in the lumbar region (6.93), and the highest in the lip region (7.96).

Sign in / Sign up

Export Citation Format

Share Document