Differences in the processing of DNA ends in Arabidopsis and tobacco and its implication for genome evolution

Surprising species-specific differences in non-homologous end-joining (NHEJ) of genomic double-strand breaks (DSBs) have been reported for the two dicotyledonous plants Arabidopsis thaliana and Nicotiana tabacum. In Arabidopsis deletions were, on average, larger than in tobacco and not associated with insertions. To establish the molecular basis of the phenomenon we analysed the fate of free DNA ends in both plant species by biolistic transformation of leaf tissue with linearized plasmid molecules. Southern blotting indicated that, irrespective of the nature of the ends (blunt, 5\u27 or 3\u27 overhangs), linearized full-length DNA molecules were, on average, more stable in tobacco than in Arabidopsis. The relative expression of a β-glucuronidase gene encoded by the plasmid was similar in both plant species when the break was distant from the marker gene. However, if a DSB was introduced between the promoter and the open reading frame of the marker, transient expression was halved in Arabidopsis as compared to tobacco. These results indicate that free DNA ends are more stable in tobacco than in Arabidopsis, either due to lower DNA exonuclease activity or due to a better protection of DNA break ends or both. Exonucleolytic degradation of DNA ends might be a driving force in the evolution of genome size as the Arabidopsis genome is more than twenty times smaller than the tobacco genome

Theory of dissociative recombination of highly-symmetric polyatomic ions

A general first-principles theory of dissociative recombination is developed for highly-symmetric molecular ions and applied to H$_3$O$^{+}$ and CH$_3^+$, which play an important role in astrophysical, combustion, and laboratory plasma environments. The theoretical cross-sections obtained for the dissociative recombination of the two ions are in good agreement with existing experimental data from storage ring experiments

Classical Model for Electronically Non-Adiabatic Collision Processes: Resonance Effects in Electronic-Vibrational Energy Transfer

A recently developed classical model for electronically nonadiabatic collision processes is applied to electronic-vibrational energy transfer in a collinear atom~diatom system, A + BC(v=1) + A*+ BC(v=0), which closely resembles Br-H{sub 2}. This classical model, which treats electronic as well as heavy particle (i.e., translation, rotation, and vibration) degrees of freedom by classical mechanics, is found to describe the resonance features in this process reasonably well. The usefulness of the approach is that it allows one to extend standard Monte Carlo classical trajectory methodology to include electronically non-adiabatic processes in a dynamically consistent way

Complications associated with the treatment of chronic limb-threatening ischemia

The aim of the work is to review current national and foreign specialized literature on various complications associated with the treatment of chronic limb-threatening ischemia. Atherosclerotic lesion of the lower limb arteries is the most common cause of tissue perfusion deficiency of the lower limbs and can lead to their loss. A radical method of treatment for chronic limb-threatening ischemia (CLTI) remains revascularization. Despite the modern possibilities of surgical treatment and many years of experience in such treatment, the percentage of surgical complications is still substantial. The level of providing qualitative care to patients with CLTI consists in the successful correction of the mentioned complications. That is why the analysis of this problem is an urgent issue of modern angiosurgery. Conclusions. Most complications after surgical treatment of atherosclerotic lower limb lesions could cause both a limb loss and a severe systemic disorder development in general. The presented data of the professional literature review of clinical and experimental studies justify the need for an early management of complications associated with surgical treatment of chronic limb-threatening ischemia. It would contribute not only to the limb preservation, but also prevent the occurrence of severe general somatic complications

Classical model for laser‐induced nonadiabatic collision processes

By synthesizing earlier work of Orel and Miller and of Meyer, McCurdy, and Miller, a model for describing laser-induced electronically non-adiabatic collision processes is constructed which treats all degrees of freedom -- heavy particle (i.e,, translation, rotation, and vibration), electronic, and photon by classical mechanics. This then makes it relatively easy to carry out calculations to simulate such processes within a dynatnically consistent framework. Application is made to the test case H + LiF {yields} Li + HF reaction considered by Light and Altenberger-Siczek. The most interesting feature revealed by these classical calculations is maxima in the reaction probability as a function of initial translational energy at energies below the laser-free threshold. It is seen that this structure can be understood as a Franck-Condon-like effect

Chronicles of Oklahoma

Necrology section from Volume 41, Number 4, Winter 1963-64. It includes documents honoring the lives of former Justice of the Supreme Court of Oklahoma Thomas Livingston Gibson and Choctaw surveyor James Brookes Wright

Observations of H3+ in the Diffuse Interstellar Medium

Surprisingly large column densities of H3+ have been detected using infrared absorption spectroscopy in seven diffuse cloud sightlines (Cygnus OB2 12, Cygnus OB2 5, HD 183143, HD 20041, WR 104, WR 118, and WR 121), demonstrating that H3+ is ubiquitous in the diffuse interstellar medium. Using the standard model of diffuse cloud chemistry, our H3+ column densities imply unreasonably long path lengths (~1 kpc) and low densities (~3 cm^-3). Complimentary millimeter-wave, infrared, and visible observations of related species suggest that the chemical model is incorrect and that the number density of H3+ must be increased by one to two orders of magnitude. Possible solutions include a reduced electron fraction, an enhanced rate of H2 ionization, and/or a smaller value of the H3+ dissociative recombination rate constant than implied by laboratory experiments.Comment: To be published in Astrophysical Journal, March 200

Breast imaging technology: Application of magnetic resonance imaging to early detection of breast cancer

Since its first introduction approximately 10 years ago, there has been extensive progress in the application of magnetic resonance imaging (MRI) to the detection and diagnosis of breast cancer. Contrast-enhanced MRI has been shown to have value in the diagnostic work-up of women who present with mammogram or clinical abnormalities. In addition, it has been demonstrated that MRI can detect mammogram occult multifocal cancer in patients who present with unifocal disease. Advances in risk stratification and limitations in mammography have stimulated interest in the use of MRI to screen high-risk women for cancer. Several studies of MRI high-risk screening are ongoing. Preliminary results are encouraging

Enhanced cosmic-ray flux toward zeta Persei inferred from laboratory study of H3+ - e- recombination rate

The H3+ molecular ion plays a fundamental role in interstellar chemistry, as it initiates a network of chemical reactions that produce many interstellar molecules. In dense clouds, the H3+ abundance is understood using a simple chemical model, from which observations of H3+ yield valuable estimates of cloud path length, density, and temperature. On the other hand, observations of diffuse clouds have suggested that H3+ is considerably more abundant than expected from the chemical models. However, diffuse cloud models have been hampered by the uncertain values of three key parameters: the rate of H3+ destruction by electrons, the electron fraction, and the cosmic-ray ionisation rate. Here we report a direct experimental measurement of the H3+ destruction rate under nearly interstellar conditions. We also report the observation of H3+ in a diffuse cloud (towards zeta Persei) where the electron fraction is already known. Taken together, these results allow us to derive the value of the third uncertain model parameter: we find that the cosmic-ray ionisation rate in this sightline is forty times faster than previously assumed. If such a high cosmic-ray flux is indeed ubiquitous in diffuse clouds, the discrepancy between chemical models and the previous observations of H3+ can be resolved.Comment: 6 pages, Nature, in pres

Vacuum-assisted therapy for patients with diabetes mellitus and chronic foot ulcers

ДИАБЕТ САХАРНЫЙСАХАРНАЯ БОЛЕЗНЬДИАБЕТИЧЕСКИЕ ОСЛОЖНЕНИЯДИАБЕТА ОСЛОЖНЕНИЯХРОНИЧЕСКИЕ РАНЫ СТОПЫ /МИКРОБ /ТЕРДИАБЕТИЧЕСКАЯ СТОПА /МИКРОБ /ТЕРЯЗВА СТОПЫ ДИАБЕТИЧЕСКАЯ /МИКРОБ /ТЕРВАКУУМ-АССИСТИРОВАННАЯ ТЕРАПИЯБАКТЕРИАЛЬНАЯ НАГРУЗКАБАКТЕРИИЦель. Определить бактериальную нагрузку ран при использовании вакуум-ассистированной терапии у пациентов с сахарным диабетом и хроническими ранами стопы. Материал и методы. Объектом исследования были пациенты с сахарным диабетом, у которых имелись хронические поверхностные (кожа, подкожная клетчатка) раны стопы с проявлениями легкой инфекции согласно классификации для определения наличия и тяжести инфекции IWGDF/IDSA. Критериями исключения были следующие: онкопатология, тяжелая сопутствующая патология, поражения костно-суставного аппарата. Пациенты лечились амбулаторно и не получали системную антибиотикотерапию. Проводилась терапия ран отрицательным давлением – 125 mm Hg в постоянном режиме. Первый этап работы выполнялся для определения уровня бактериальной нагрузки ран до и после 3 суток вакуум-ассистированной терапии (группа из 10 пациентов). Вторая группа (10 пациентов) была отобрана для определения динамики изменений бактериальной нагрузки ран после каждых 24 часов вакуум-ассистированной терапии, наблюдение проводилось на протяжении 96 часов экспозиции повязки. Уровень бактериальной нагрузки контролировали по изменениям показателя колониеобразующих единиц в грамме ткани (КОЕ/г) биопсийного материала из ран. Результаты. Средняя бактериальная нагрузка ран у пациентов первой группы после 3 суток терапии составляла 8,11±1,27 lg КОЕ/г, что на 31,9% превышало исходный уровень (р<0,05). При исследовании материала из ран пациентов второй группы установлено увеличение средней бактериальной нагрузки ран через 24, 48, 72 и 96 часов после начала терапии, на 10,8%, 16,4%, 38,9% и 58,6% соответственно (р<0,05). Заключение. Использование вакуум-ассистированной терапии у пациентов с сахарным диабетом и хроническими ранами стопы с проявлениями инфекции не обеспечивает необходимого контроля уровня бактериальной нагрузки, поэтому метод необходимо применять в комплексе с системной антибиотикотерапией.истированной терапии у пациентов с сахарным диабетом и хроническими ранами стопы.Objective. To determine the bacterial load of wounds at the application of vacuum-assisted therapy for patients with diabetes mellitus and chronic foot ulcers. Methods. The object of the research was patients with diabetes mellitus with chronic superficial (skin, subcutaneous tissues) wounds of the foot with the signs of mild infection according to the classification for determination of presence and severity of infection of IWGDF/IDSA. Oncopathology, heavy concomitant pathology and lesions of the osteoarticular apparatus were the criteria of exception. Patients were treated as out-patients and did not get system antibiotic therapy. Therapy of wounds was conducted by negative pressure – 125 mm Hg in the continuous mode. The first stage of work was conducted to find out the level of the bacterial load of wounds before and 3 days after the vacuum-assisted therapy (the group was of 10 patients). The second group (10 patients) was selected to determine the dynamics of changes of the wound bioburden level after every 24 hours of vacuum-assisted therapy, the observation was performed during 96 hours of the bandage exposure. The level of the bacterial load was controlled according to the changes of index of colony-forming units in the gram of tissue (CFU/g) of the wound biopsy material. Results. The average bioburden level of wounds for the 1st group patients after the removal of bandage was 8.11±1.27 lg CFU/g, this exceeds the initial level by 31.9 % (р<0.05). The investigation of the material from the wounds of the 2nd group patients established a considerable increase of the average bioburden level of wounds in 24, 48, 72 and 96 hours after the beginning of the therapy, 10.8 %, 16.4 %, 38.9 % and 58.6 % accordingly (р<0.05). Conclusions. In patients with diabetes mellitus and chronic wounds of the foot with signs of infection, vacuum-assisted therapy does not provide essential control of the bioburden level and should be used in combination with systemic antibiotic therapy