Варикозная болезнь нижних конечностей

МЕТОДИЧЕСКИЕ РЕКОМЕНДАЦИИВАРИКОЗНОЕ РАСШИРЕНИЕ ВЕНКОНЕЧНОСТЬ НИЖНЯЯОБРАЗОВАНИЕ МЕДСЕСТРИНСКОЕ, ПОВЫШЕНИЕ КВАЛИФИКАЦИИФЛЕБОЛОГИЯКурс лекций по флебологии включает в себя лекции, посвященные истории развития учения о варикозной болезни нижних конечностей, основным анатомическим сведениям, а также актуальным вопросам диагностики и лечения варикозной болезни нижних конечностей. Приводимые в лекционном курсе данные основаны как на результатах собственных исследований и практического опыта автора за 25 лет, так и на данных современных литературных источников и руководств. Курс лекций соответствует учебной программе "Практическая флебология с основами флебосклерозирующей терапии" и предназначен слушателям факультета повышения квалификации, студентам старших курсов лечебного факультета и врачам хирургам лечебной сети

Stop worrying; start growing: Risk research on GM crops is a dead parrot: it is time to start reaping the benefits of GM

Opponents of genetically modified crops continue to raise concerns about risk, despite 20 years of research disproving their claims. Science should close the book on risk research and turn to studying the economic and environmental benefits of agricultural biotechnolog

Human brain function evaluated with rCBF-SPECT : memory and pain related changes and new diagnostic possibilities in Alzheimer’s disease

The aim of this doctoral thesis was to study the influence of memory, pain, age and education on the regional cerebral blood flow (rCBF), i.e. brain function, in early Alzheimer's disease (AD) and in chronic neck pain patients in comparison to healthy controls and in healthy elderly per se. This was done by optimizing single photon emission computed tomography (SPECT) as a method to study rCBF with the tracer Technetium-99m (99mTc) hexamethylpropyleneamine oxime (HMPAO) and by matching all image data to a brain atlas before evaluation. The rCBF-SPECT was evaluated and developed to obtain higher diagnostic accuracy in AD and in chronic neck pain patients it was used to study basic pain related cerebral processes in chronic pain of different origin. A new semimanual registration method, based on fiducial marker, suitable for investigations with low spatial resolution was developed. The method was used to reconstruct images with an improved attenuation and scatter correction by using an attenuation-map calculated from the patients' previously acquired CT images. The influence of age and education on rCBF was evaluated with statistical parametric mapping, SPM in healthy elderly. The main findings were age related changes in rCBF in regions close to interlobar and interhemispheric space but not in regions typically affected in early AD, except for the medial temporal lobe. The theory of a 'cognitive reserve' in individuals with a longer education was supported with findings in the lateral temporal lobe, a region related to semantic memory, and in the frontal lobe. A cross-sectional study of chronic neck pain patients showed extensive rCBF changes in coping related regions in a non-traumatic pain patients compared to both healthy and a pain group with a traumatic origin, i.e. whiplash syndrome. The whiplash group displayed no significant differences in rCBF in comparison with the healthy controls. This suggests different pain mechanisms in these groups. The AD-patients showed a significantly lower rCBF in temporoparietal regions including left hippocampus. These changes were associated to episodic memory performance, and especially to face recognition. The diagnostic sensitivity for AD was high. The face recognition test (episodic memory) was used in AD patients to improve the sensitivity of method, i.e. memory-provoked rCBF-SPECT (MP-SPECT). The results were compared to healthy controls and the reductions of rCBF in temporoparietal regions were more pronounced in mild AD during provocation. Memory provocation increased the sensitivity of AD-related rCBF changes at group level. If a higher sensitivity for AD at the individual level is verified in future studies, a single MP-SPECT study might then be of help to set diagnosis earlier. In conclusion rCBF in temporoparietal regions are associated to an impaired episodic memory in early AD. Changes in these regions do not have a strong connection to chronological age. The diagnostic sensitivity of rCBF-SPECT in AD is high and there is a potentially higher sensitivity if memory provoked investigations are used. The findings in this thesis have given an increased knowledge of underlying cerebral pain processing in non-traumatic and traumatic (whiplash) neck pain. Preliminary results supporting the theory of 'cognitive reserve' by showing a correlation between long education and preserved rCBF was found in healthy elderly

Excited state dynamics in alternating polyfluorene copolymers

We present the excited state dynamics of the low band gap alternating polyfluorene copolymer, DiO-PFDTBT. The copolymer structure is an alternating sequence of donor and acceptor units consisting of 9,9-dioctyl-9H-fluorene and 4,7-di-thiophen-2-yl-benzo[1,2,5]thiadiazolyl units. Calculations have predicted that the first excited state has charge transfer character, while the second strongly allowed excited state is a delocalized π-conjugated state. We show that the excited state dynamics involves internal conversion (IC) from the second strongly allowed excited state to the first excited state. Furthermore, excitation energy transfer (EET) on the 1–10 ps time scale is observed as well as a subsequent formation of a stabilized long-lived emissive state, which has a decay time of 3.25 ns. The origin of this stabilized state is discussed in relation to the intrinsic charge transfer nature of the DiO-PFDTBT

Detecting small liver tumors with In-111-Pentetreotide SPECT-A Collimator study based on Monte Carlo simulations

In In-111- pentetreotide single-photon emission computed tomography (SPECT), the tumor-to-background-uptake ratio is generally high. The noise is, however, also usually on a high level, and in combination with the low spatial resolution of SPECT, this may lead to difficulties in the detection of small tumors. This is especially the case in regions with a relatively high background activity, such as in the liver, which is a common region for somatostatin-positive metastases. Visually detecting the small tumors is important for a successful treatment of the cancer disease. In this paper, we compare three different parallel-hole collimators for In-111-pentetreotide SPECT regarding contrast as a function of image noise for a phantom simulating small tumors in liver background. The corresponding contrast-to-noise ratios are also presented. All raw-data projections are produced using Monte Carlo simulations. The collimators are of type low-energy general-purpose (LEGP), extended LEGP (ELEGP), and medium-energy general-purpose (MEGP). Reconstructions were performed with OSEM both with and without model-based compensation. Of the investigated collimators, the ELEGP collimator proved to be the most optimal for the smallest tumors, both with and without model-based compensation included in the reconstruction. It is also shown that model-based compensation outperforms the conventional reconstruction technique

The Influence of Driving Force on Formation and Geminate Recombination of Charges in Alternating Polyfluorene Copolymer/Fullerene Blends

Conjugated polymer/fullerene-based solar cells are, due to their potential flexibility, cost efficiency and low weight, interesting as future alternatives to today’s silicon cells [1]. In these cells, both the dissociation of the polymer exciton into extractable charges, i.e. charges that are free and mobile, and the recombination of the free charges are expected to be crucial in order to obtain high light-to-charge conversion efficiencies. The exciton dissociation is believed to strongly depend upon the driving force [2] while the driving force dependence of the recombination has not been thoroughly investigated. Therefore, we have studied the charge formation and recombination in blends of alternating polyfluorene copolymers (APFO polymers) and PCBM with different driving force. By varying the polymer in the blends, a driving force range of 0.05–0.77 eV has been covered

Appearance of coherent artifact signals in femtosecond transient absorption spectroscopy in dependence on detector design

The appearance of coherent artifact signals in transient absorption spectroscopy employing a spectrally integrated detection system is studied. The influence of the detection design on the shape of the observed signal is detailed and the experimentally very important case, in which the shape of the coherent artifact is strongly influenced by the presence of the sample itself, is considered - leading to the situation that the artifact signal cannot be accounted for by simple comparison of the kinetics obtained for the solvent only. Finally an estimate of the relative contribution of the artifact to the overall transient absorption change is presented facilitating the interpretation of short time transients in the presence of artifact contributions and allowing to estimate the excited state absorption cross-section for a known pump-intensity dependence of the artifact signal