PubMed Health⌕ Search

Biomedical subjects

O Petrov

Publications and source records attributed to O Petrov.

12 recordsLinked to original sources
PubMed2006

Inorganic salt hydrates as cryoporometric probe materials to obtain pore size distribution.

The depression of the melting temperature of Zn(NO3)2.6H2O was used to obtain the pore size distributions in controlled pore glasses. Measured by 1H NMR, the average value of the temperature depression DeltaT and the known average pore size yield K=DeltaT.d approximately 116 K.nm as the material-dependent factor for Zn(NO3)2.6H2O in the Gibbs-Thompson equation. The melting temperature is close to room temperature. Hence, this salt hydrate and some related other ones are better materials than water (K approximately 50 K.nm) for cryoporometric studies of systems with hydrophilic pores. The data also provide 46 mN/m for the solid-liquid surface tension of this salt hydrate.

Journal Article↗
PubMed2004

Experimental determination of dust-particle charge in a discharge plasma at elevated pressures.

The charge of dust particles is determined experimentally in a bulk dc discharge plasma in the pressure range 20-100 Pa. The charge is obtained by two independent methods: one based on an analysis of the particle motion in a stable particle flow and another on an analysis of the transition of the flow to an unstable regime. Molecular-dynamics simulations of the particle charging for conditions similar to those of the experiment are also performed. The results of both experimental methods and the simulations demonstrate good agreement. The charge obtained is several times smaller than predicted by the collisionless orbital motion theory, and thus the results serve as an experimental indication that ion-neutral collisions significantly affect particle charging.

Journal Article↗
PubMed2003

Kinetic measurements of shock wave propagation in a three-dimensional complex (dusty) plasma.

"Complex plasmas" consist of electrons, ions, and charged microparticles. The latter are individually observable, allowing kinetic measurements in plasmas. Using a sudden gas pulse, a traveling perturbation was initiated in such a complex plasma and its propagation, acceleration, and steepening-possibly into a shock was followed. The experiment was performed in the PKE-Nefedov laboratory under microgravity conditions on the international space station, i.e., in a complex plasma cloud with very little stored (potential or free) energy and thus free of, e.g., parametric instabilities. The perturbation front remained remarkably smooth, with a microroughness of the order of the interparticle distance. The observations are presented and interpreted.

Journal Article↗
PubMed2001

Dimethyl 2-[[2-(methoxycarbonyl)-1-(methoxycarbonylmethyl)pyrrol-4-yl]methylene]propanedioate.

The title compound, C(15)H(17)NO(8), is a pyrrole-ethene derivative with potential biological activity. Although a large part of the molecule is planar, there is no structural evidence for any conjugation push-pull effect across the ethylenic bond, which is usually observed for substituted ethylenes; pi-electron delocalization appears to be restricted to the 2-(methoxycarbonyl)pyrrole moiety.

Crystallography, X-Ray↗
PubMed2000

A comparison of calibrated and non-calibrated 5.07 nylon monofilaments.

The study compares the mechanical performance of two types of nylon monofilaments used in testing for the presence of protective sensation in diabetics with peripheral neuropathy. Comparisons of the application force between a group of calibrated and a group of non-calibrated 5.07 nylon monofilaments were conducted to determine the properties of each type of filament. The analysis demonstrated that there was no significant difference in the application force generated between calibrated and non-calibrated nylon monofilaments.

Calibration↗
PubMed1998

The podiatric examination.

With the evolution of the AIDS epidemic into a relatively chronic disease, practitioners will continue to see an increase in the number of patients infected with HIV for the diagnosis and management of podiatric pathology. A thorough history and physical examination, taken with a complete knowledge base of HIV implications, will enhance the ability to form the strategies required to treat the manifestations of this disease and to request appropriate referrals. Laboratory studies and other diagnostic techniques have been developed and increased in specificity to allow for earlier and more precise identification of the presenting pathology. A continuously expanding choice of medications is available for treatment. The clinical presentations of HIV infection in the foot involve nearly all organ systems. This article reviews the podiatric role as part of the medical team in the diagnosis and treatment of patients infected with HIV.

AIDS-Related Opportunistic Infections↗
PubMed1990

Vascular hamartoma. A case report.

A case of a vascular hamartoma occurring in the plantar aspect of the foot is reported. Surgical excision of the mass was the treatment of choice, and the surgery was performed after appropriate diagnostic measures had been undertaken. A normal postoperative course ensued, and no recurrence has been reported.

Adult↗
PubMed1988

Footwear and ankle stability in the basketball player.

Ankle stability in basketball players is affected by footwear. Athletic shoe manufacturers have introduced specialized lacing systems and high-top performance shoes to improve ankle stability. These performance shoes not only aid in preventing ankle injuries, but also protect injured ankles.

Ankle Injuries↗
PubMedDate not supplied

The modified Hohmann bunionectomy: a retrospective review.

A retrospective review of 35 modified Hohmann bunionectomies is presented with analysis of objective radiographic and subjective patient questionnaire results. Thirty-five modified Hohmann bunionectomies were performed, on 29 patients over a 6-year period with follow-up ranging from 11 months to 5 years and 11 months. The modification involves resection of a triangular wedge from the first metatarsal, to minimize shortening, and utilizes two points of fixation. In total, 88% of those patients responding to our questionnaire had either excellent or good results. The Hohmann bunionectomy is a valuable procedure in alleviating symptoms caused by hallux abductovalgus.

Adult↗
PubMedDate not supplied

The durability of the Semmes-Weinstein 5.07 monofilament.

Peripheral neuropathy is a risk factor that predisposes diabetic patients to plantar foot ulcerations and lower extremity amputations. Clinicians have searched for a reliable, cost-effective, and simple method in the identification of diabetic patients who are at increased risk of developing plantar foot ulcers. Currently, many diabetic foot clinics utilize the Semmes-Weinstein 5.07/10 g monofilament in this identification process. Ten 5.07 monofilaments were placed in an Instron Dynamic Testing Instrument and their respective filament forces were measured utilizing a Mettler scale after being subjected to repetitive applications. After 500 cycles were performed, there was an average filament force reduction of 1.2 g. After 1,500 cycles, there was still an average reduction of 1.2 g. F-testing and the Duncan test identified a significant difference between filament forces at 0, 500, 1,000, and 1,500 cycles. These data lead to a conclusion that continual utilization of the nylon filaments may lead to a reduced ability to accurately detect peripheral neuropathy and identify those who are at risk for the development of plantar foot ulcerations.

Diabetic Foot↗
PubMedDate not supplied

Recurrent plantar ulceration following pan metatarsal head resection.

Although the pan metatarsal head resection, since it was originally described and performed by Hoffman in 1911, has proven to be an effective and viable procedure in treating many forefoot deformities, it is not without its own complications. The authors provide an historical perspective of the pan metatarsal head resection, a discussion on the complication of recurrent plantar ulceration after the pan metatarsal head resection, and a review of their own experience with this procedure. A retrospective review was performed of all patients having undergone pan metatarsal resections between August 1980 and April 1993. Twenty procedures were performed on 12 patients with diabetic neuropathy, and 21 procedures were performed on 15 patients with rheumatoid arthritis. The incidence of recurrent plantar ulceration after surgical correction was 25% and 28%, respectively. All 27 patients underwent primary healing. The authors, therefore, conclude that the complication of recurrent plantar ulceration after this procedure is a very likely and distinct possibility.

Arthritis, Rheumatoid↗