Biomedical subjects

D Lu

Publications and source records attributed to D Lu.

329 records · Page 19Linked to original sources

PubMedDate not supplied

Alphamethrin-impregnated bed nets for malaria and mosquito control in China.

A community-based intervention trial was carried out to evaluate the effectiveness of alphamethrin-impregnated bed nets for control of Plasmodium vivax malaria and its vector in an area of moderate endemicity in southern Henan province, central China in 1990. Malaria incidence was significantly lower in the intervention group than in the comparison group (2.03 vs. 3.57 per 100 person-years at risk). The protective efficacy for malaria incidence was 43%. The prevalence of malaria parasitaemia among children under 10 years old in the intervention group was about one-quarter of that in the comparison group (0.93% vs. 3.25% and 0.71% vs. 1.96% after one and 4 months use of impregnated nets, respectively). Alphamethrin-impregnated bed nets had a mass killing effect on vector mosquitoes. The outdoor person-biting density of Anopheles anthropophagus and A. sinensis decreased by 70.3% and 29.3% respectively. The density of these 2 mosquito species found resting inside treated nets was close to zero. No side effect was found among users of impregnated bed nets. Impregnation with alphamethrin was more effective on polyester than on cotton netting and residual effects lasted at least one year. Use of alphamethrin is less expensive than permethrin and deltamethrin.

Animals↗

PubMedDate not supplied

NMR T2 distributions and two phase flow simulations from x-ray micro-tomography images of sandstones.

The distribution of fluids in the pore space of a series of sandstones is calculated as a function of capillary pressure using a two phase flow simulation model. The pore space is represented by a system of channels and nodes which are derived from x-ray micro-tomography images of sandstones. The sandstones studied varied in permeability from approximately 40 to 3,000 mD. The simulation results illustrate the significance of the pore level by-pass phenomena in controlling the location of fluids within the pore structure. The implications of these results on the interpretation of NMR T(2) distributions to determine the irreducible water saturation are discussed.

Computer Simulation↗

PubMedDate not supplied

Conformational transitions of polypeptides in ternary solvent systems.

Phase diagrams for conformational transitions of polypeptides in ternary organic solvent systems containing two active and one inert component are calculated for a model which takes into account possible interaction of the two active components with each other as well as with the polypeptide backbone. The results of experimental determinations of conformational transitions and isothermal phase boundaries for poly(beta-benzyl L-asparate) (PBA) in three-model solvent systems are in generally good accord with the theory. The solvent systems are: (a) 1-chloropropionic acid-dichloroacetic acid (DCA)-1,1,2,2-tetrachloroethane (TCE), (b) monochloroacetic acid-DCA-TCE, and (c) dimethyl sulfoxide-DCA-TCE.

Binding Sites↗

PubMedDate not supplied

Results of myelography in seven dogs with myelomalacia.

Myelomalacia is a hemorrhagic infarction of the spinal cord that can occur as a sequel to acute spinal cord injury. Myelomalacia may be focal or diffuse; the diffuse form is typically associated with cranial migration of neurologic signs ("ascending syndrome") and is often fatal. In a retrospective study of seven affected dogs, diffuse myelomalacia was associated with intervertebral disc extrusion in five dogs, focal myelomalacia was associated with fibrocartilagenous embolus in one dog, and had no apparent cause in one dog. The myelographic signs included a variable degree of contrast medium infiltration into the spinal cord in six dogs (86%) and/or spinal cord swelling in six dogs (86%). In one dog with focal myelomalacia, the only myelographic sign was spinal cord swelling.

Animals↗

PubMedDate not supplied

Material in the middle ear of dogs having magnetic resonance imaging for investigation of neurologic signs.

The aim of this study was to determine the prevalence and potential significance of finding material in the middle ear of dogs having magnetic resonance (MR) imaging. Of 466 MR studies reviewed, an increased signal was identified in the tympanic bulla in 32 (7%) dogs. Cavalier King Charles spaniels, Cocker spaniels, Bulldogs, and Boxers were over-represented compared to the population of dogs having MR imaging. Five (16%) dogs had definite otitis media and one (3%) had a meningioma invading the middle ear. Of the remaining dogs, 13 (41%) had possible otitis media and 13 (41%) had neurologic conditions apparently unrelated to otitis media. The most common appearance of material in the middle ear was isointense in T1-weighted images and hyperintense in T2-weighted images. There was no apparent correlation between the signal characteristics of the material and the diagnosis. Enhanced signal after gadolinium administration was observed affecting the lining of the bulla in dogs with otitis media and in dogs with unrelated neurologic conditions. In dogs without clinical signs of otitis media, finding an increased signal in the middle ear during MR imaging may reflect subclinical otitis media or fluid accumulation unrelated to inflammation. Brachycephalic dogs may be predisposed to this condition.

Animals↗