An analysis of chosen image formation algorithms for synthetic aperture radar with FMCW

The modelling of FMCW SAR systems, due to long signal duration time, commonly used start-stop approximation for pulsed radars causes errors in the image. Continuous motion of the radar platform results in additional range-azimuth couplings and range walk term that should be considered in processing of signal from this type of radar. The paper presents an analysis of the following algorithms: Time Domain Correlation (TDC), Range Doppler Algorithm (RDA), and Range Migration Algorithm (RMA). The comparison of the algorithms is based on theoretical estimation of their computation complexity and the quality of images obtained on the basis of real signals of FMCW SAR systems

Metody i schemat okresowy kontroli obrazowej po przeznaczyniowym leczeniu tętniaków wewnątrzczaszkowych: systematyczny przegląd piśmiennictwa

Background and purpose To review the diagnostic value of angiographic methods and the optimal timetable for follow-up imaging of patients after endovascular treatment of intracranial aneurysms. Material and methods A comprehensive computer-aided search for relevant primary papers was performed using the MEDLINE, PubMed, Embase, and Cochrane Collaboration database from January 1991 to March 2011. Original papers were included that reported either diagnostic value of angiographic modalities for follow-up vs. digital subtracted angiography (DSA) or comparison of aneurysm occlusion rate in delayed vs. early follow-up. Results The systematic review identified 35 relevant studies: 3 on the diagnostic value of three-dimensional (3D) DSA, 30 on the performance of magnetic resonance angiography (MRA), and 3 on time schedules for follow-up. 3D DSA had sensitivity of 100%, and specificity of 58.3-94.7%. Magnetic resonance angiography had sensitivity of 28.4-100%, and specificity of 50.0-100%. The proportion of aneurysms that recanalized between the early follow-up examination at 6 months and the delayed imaging at 1.5-6.0 years was 0-2.5%. Conclusions Magnetic resonance angiography seems to be the best imaging method for the follow-up. In selected cases, when invasive angiography is necessary, 3D DSA should be considered to improve the diagnostic accuracy. Most patients who present with stable and adequate aneurysm occlusion at 6 months after coiling may not require further follow-up.Wstęp i cel pracy Celem pracy był przegląd opublikowanych prac oryginalnych na temat wartości diagnostycznej metod angiograficznych oraz schematów czasowych kontrolnych angiografii u chorych po przeznaczyniowym leczeniu tętniaków wewnątrzczaszkowych. Materiał i metody Przeprowadzono przegląd systematyczny piśmiennictwa indeksowanego w bazach MEDLINE, PubMed, Embase i Cochrane Collaboration w okresie od stycznia 1991 do marca 2011 r. Do analizy włączono badania oryginalne, w których określano wartość diagnostyczną metod angiograficznych w ocenie tętniaków po embolizacji w porównaniu z konwencjonalną arteriografią subtrakcyjną (DSA). Włączono również badania, w których porównywano wyniki embolizacji we wczesnej i późnej kontroli angiograficznej. Wyniki Kryteria włączenia do analizy spełniło 35 prac, w tym 3 oceniające wartość trójwymiarowej DSA (3D DSA), 30 oceniających angiografię rezonansu magnetycznego (MRA) i 3 dotyczące schematu czasowego kontroli angiograficznej. W analizowanych pracach 3D DSA miała czułość 100% i swoistość 58,3–94,7%, natomiast czułość i swoistość MRA wynosiły odpowiednio 28,4–100% i 50–100%. Odsetek tętniaków, które uległy rekanalizacji pomiędzy wczesnymi (po 6 miesiącach) i późnymi badaniami kontrolnymi (po 1,5–6 latach), wyniósł 0–2,5%. Wnioski Angiografia rezonansu magnetycznego wydaje się najlepszą metodą angiograficznej kontroli chorych po embolizacji tętniaków. W przypadkach, kiedy konieczne jest wykonanie angiografii inwazyjnej, 3D DSA może istotnie poprawić wartość diagnostyczną badania. Znaczna część chorych, u których stwierdza się prawidłowe wypełnienie tętniaka po 6 miesiącach od embolizacji, nie wymaga dalszej kontroli

Interaction of diatomic molecules with nickel ions inside the channels of high silica zeolites : an EPR and DFT study

Interaction of CO, NO, and O-2 diatomics with Ni-II and ions dispersed in ZSM-5 zeolite was investigated by electron paramagnetic resonance (EPR) spectroscopy and density functional theory (DFT) modelling. The resulting adducts Ni-I-CO, Ni-II-NO, and Ni-I-O-2 were identified based on g-tensor parameters, obtained by computer fitting of the powder EPR spectra, and next ascertained by parallel relativistic DFT calculations of the corresponding g-tensor values. The structures of the Ni-I-CO, Ni-II-NO, and Ni-I-O-2 complexes were obtained by geometry optimization with the Kohn-Sham method. Binding of the diatomics was discussed in terms of the spin-pairing and electron density transfer events. Interaction of CO with Ni-I cations led to the pronounced change in the coordination and electronic structure of the Ni-I center, however, no redox processes were observed in agreement with the "innocent" nature of CO as a ligand. On the contrary, strong electron and spin density redistribution was observed upon NO and O-2 interaction ("non-innocent ligands") leading to the formation of the bound nitrosonium NO delta+ and superoxo O-2(-) species, respectively

Activated carbon modification towards efficient catalyst for high value-added products synthesis from alpha-pinene

DT0-activated carbons modified with HCl and HNO3 acids, which were used for the first time in the catalytic process of alpha-pinene isomerization, are presented in this study. The carbon materials DT0, DT0_HCl, DT0_HNO3, and DT0_HCl_HNO3 were examined with the following methods: XRF, SEM, EDX, XPS, FT-IR, XRD, and N2 adsorption at -196 °C. It was shown that DT0_HCl_HNO3-activated carbon was the most active material in the alpha-pinene isomerization process. Detailed studies of alpha-pinene isomerization were carried out over this carbon by changing the reaction parameters such as time (5–180 min) and temperature (60–175 °C). The 100% conversion of alpha-pinene was achieved at the temperature of 160 °C and catalyst content of 5 wt% after 3 h over the DT0_HCl_HNO3 catalyst. Camphene and limonene were the main products of the alpha-pinene isomerization reaction.Peer ReviewedPostprint (published version

Risk factors of suicidal behavior in alcohol-dependent individuals

Problem zachowań samobójczych związanych z zaburzeniami psychicznymi jest od lat przedmiotem wielu badań. Jako grupy najwyższego ryzyka najczęściej są wymieniani pacjenci z zaburzeniami afektywnymi. Istnieją jednak wyniki badań sugerujące, że osoby uzależnione od alkoholu mogą być bardziej obciążone ryzykiem samobójstwa niż chorzy na depresję. Poszukiwanie czynników sprzyjających decyzjom samobójczym w tej grupie pacjentów jest zatem niezwykle ważne. Istotny wpływ na prawdopodobieństwo podjęcia zachowań samobójczych mają czynniki demograficzne, psychopatologiczne, psychologiczne, społeczne, rodzinne, biologiczne i genetyczne, a także związane ze stanem somatycznym pacjentów oraz przebiegiem uzależnienia od alkoholu i jego leczenia. W pracy dokonano przeglądu aktualnych badań oceniających poszczególne grupy czynników ryzyka zachowań samobójczych u osób uzależnionych od alkoholu. Psychiatria 2011; 8, 1: 7–17The problem of suicidal behavior related to psychiatric disorders has been investigated in numerous studies. As well known, patients with affective disorders are the group with the highest risk of suicide. Nevertheless, there is some research studies suggesting that alcohol dependence may increase risk of suicide, even larger than depression. Thus, investigating risk factors of suicide among alcoholics has become very important. There are several areas, which have been indicated as essential for risk of suicide in alcohol dependence, including demographic, psychopathological, psychological, social, family, biological, and genetic factors as well as health- -related, or history of abuse and its treatment. In the paper, current research studies on risk factors of suicide behavior in alcohol dependence are reviewed. Psychiatry 2011; 8, 1: 7–1

Diagnostic features of EPR spectra of superoxide intermediates on catalytic surfaces and molecular interpretation of their g and A tensors

The use of electron paramagnetic resonance spectroscopy to study the superoxide intermediates, generated by end-on and side-on adsorption of the naturally abundant and 17O-enriched dioxygen on catalytic surfaces is discussed. Basic mechanisms of O2 − radical formation via a cationic redox mechanism, an anionic redox mechanism, and an electroprotic mechanism are illustrated with selected oxide-based systems of catalytic relevance. Representative experimental spectra of various complexities are analyzed and their diagnostic features have been identified and interpreted. The molecular nature of the g and A tensors of the electrostatic and covalent superoxide adducts is discussed in detail within the classic and density functional theory based approaches

Carbonaceous catalysts from orange pulp for limonene oxidation

The possibility of orange pulp utilization for nanoporous carbons production was investigated. Moreover, processing the obtained materials as limonene oxidation catalysts was studied as well. Limonene was separated from orange pulp obtained from fragmented orange peels—the waste from industrial fruits processing—by means of simple distillation. After the sepa-ration of limonene from the biomass, the dried orange pulp was converted to three types of nanoporous carbon catalysts: without activating agent, with NaOH, and with KOH. The catalysts were characterized by XRD, SEM, EDX, AFM, and sorption of N2 methods. The activities of the obtained catalysts were tested in the oxidation of limonene to perillyl alcohol (the main product), carveol, carvone, and 1,2-epoxylimonene and its diol. In the oxidation processes, hydrogen peroxide was used as the oxidizing agent. This work has shown for the first time that nanoporous carbons obtained from orange pulp waste, after separation of limonene, are active catalysts for limonene oxidation to industrially important value-added productsPeer ReviewedPostprint (published version

Screening for trisomy 21 based on maternal age, nuchal translucency measurement, first trimester biochemistry and quantitative and qualitative assessment of the flow in the DV — the assessment of efficacy

Objectives: The aim of the study was to compare effects of addition of two methods of ductus venosus (DV) flow assessment: qualitative — the assessment of shape of the A-wave (positive or negative), and quantitative — based on the pulsatility index for veins (DVPI) to the basic screening for trisomy 21 at 11 to 13 + 6 weeks of pregnancy. Material and methods: The ultrasound examination was performed in 8230 fetuses in singleton pregnancies at 11– –13 + 6 wks, as a part of a routine screening for chromosomal defects. In DV A-wave was assessed and DVPI was calculated. After the scan blood sample was taken for first trimester biochemistry (BC). Risk for chromosomal defects was calculated and high-risk patients were offered an invasive test for karyotyping. Results: Basic screening with following combination of markers: MA, NT and BC provided lowest detection rate (DR) 87.50% for FPR = 6.94%. After adding qualitative DV A-wave assessment DR increased to 88.75% for FPR = 5.65%. The best DR = 93.75% for FPR = 5.55% was achieved when quantitative DVPI was added. The application of the Receiver Operating Curves curve confirmed validity of the addition of DV flow assessment to the screening model. The highest diagnostic power of the test was achieved when DVPI was added, with the ROC AUC of 0.974. Conclusions: The assessment of DV flow performed at 11–13 + 6 weeks increases DR for trisomy 21 and reduces FPR. The screening model based on the quantitative DV flow analysis (DVPI) gives better results compared to the qualitative flow assessment

Nasal bone in screening for T21 at 11–13 + 6 weeks of gestation — a multicenter study

 Objectives: Trisomy 21 is one of the most common chromosomal defects diagnosed prenatally. Screening for Down syndrome is based on maternal age, measurement of crown-rump length, nuchal translucency and fetal heart rate, together with free β-hCG and PAPP-A at 11 to 13 + 6 weeks. Introduction of additional ultrasound marker of trisomy 21 (evaluation of the nasal bone) may result in increased DR and decreased invasive diagnostic testing rates (FPR).Material and methods: Ultrasound scan with NB evaluation was performed in 5814 fetuses during routine screening for chromosomal defects at 11 to 13 + 6 weeks of gestation. DR and FPR coefficients were calculated for 4 levels of risk as cut-off points for screening model 1, based on MA, NT, and first trimester biochemistry, as well as for screening model 2, based on MA, NT, first trimester biochemistry and NB.Results: There were 5708 normal cases, 71 cases of trisomy 21 and 35 cases of other chromosomal defects. NB was absent in 46 (64.8%) cases and present in 25 (35.3%) cases of trisomy 21, comparing to present NB in 5463 (95.7%) and absent in 245 (4.3%) of normal cases.Conclusions: First-semester screening with additional NB assessment significantly increases the detection rate for trisomy 21 and decreases the rate of false-positive results. Adding NB evaluation at the risk level of 1:50 causes only a small increase in detection rate. Invasive procedures should be performed in that group regardless NB assessment

Bioequivalence study of 2.5 mg film-coated bisoprolol tablets in healthy volunteers

Wstęp: Bisoprolol jest jednym z najczęściej stosowanych beta-adrenolityków cechujących się kardioselektywnością i pozbawionym wewnętrznej aktywności sympatykomimetycznej. Jest powszechnie stosowany w leczeniu choroby niedokrwiennej serca czy niewydolności serca. Cel: Celem pracy była ocena równoważności biologicznej tabletek powlekanych zawierających bisoprolol w dawce 2,5 mg (Bisocard® — lek badany) w odniesieniu do oryginalnego produktu leczniczego (Concor Cor 2.5® — lek referencyjny). Metody: Przeprowadzono badanie otwarte z randomizacją w schemacie krzyżowym, po pojedynczym podaniu na czczo zdrowym ochotnikom rasy białej bisolprololu w dawce 10 mg (4 tabletki po 2,5 mg). Próbki krwi pobierano do 60. godziny po podaniu leku. Stężenie bisoprololu w osoczu oznaczono zwalidowaną metodą LC-MS/MS. Produkty lecznicze uznano za równoważne biologicznie, gdy 90-procentowe przedziały ufności (CI) stosunków średnich geometrycznych (produkt badany/referencyjny) dla zlogarytmowanych AUC(0–t), AUC(0–∞) i Cmax mieściły się w granicach 80–125%. Działania niepożądane monitorowano na podstawie parametrów klinicznych i zgłoszeń ochotników. Wyniki: Dwudziestu sześciu zdrowych ochotników obu płci (średnia wieku ok. 29 lat, wskaźnik masy ciała 22,7 kg/m2) zostało włączonych do badania, a 24 z nich ukończyło część kliniczną badania. Otrzymano następujące stosunki średnich geometrycznych (produkt badany/referencyjny): AUC(0–t) 95,16% (90% CI 92,52–97,87%), AUC(0–∞) 95,08% (90% CI 92,40–97,83%) oraz Cmax 100,00% (90% CI 94,83–105,45%). Nie zaobserwowano istotnych statystycznie różnic w ocenianych parametrach farmakokinetycznych między produktami badanym i referencyjnym. Nie stwierdzono poważnych zdarzeń niepożądanych w badanej populacji. Wnioski: W badanej populacji stwierdzono równoważność biologiczną leku generycznego (Bisocard®) z produktem referencyjnym (Concor Cor 2.5®). Oba produkty cechują się porównywalną, dobrą tolerancją i bezpieczeństwem.Background: Bisoprolol is one of the most widely used beta-blockers characterised by cardioselectivity, and it has no intrinsic sympathomimetic activity. It is commonly used in the treatment of coronary heart disease and heart failure.   Aim: The aim of study was to assess the bioequivalence of the film-coated tablets containing 2.5 mg of bisoprolol (Bisocard® — the medicinal product) to the original medicinal product (Concor Cor 2.5® — the reference).   Methods: A randomised, open-label, two-period, crossover, single-dose, relative bioavailability study was conducted in fasted healthy Caucasian volunteers. A single 10-mg oral dose (four tablets of 2.5 mg) of the test or reference product was followed by a 14-day wash-out period, after which the subjects received the alternative product. Blood was sampled within a period of 60 h post administration in pre-specified time points. Bisoprolol concentrations were determined by a validated LC-MS/MS method. The products were considered bioequivalent if the 90% confidence interval (CI) of the log-transformed geometric mean ratios (test vs. reference) for AUC(0–t), AUC(0–∞), and Cmax were within 80–125% limits. Adverse events were monitored during the study based on the subject claims and clinical parameters.   Results: Twenty-six healthy male and female volunteers (mean age ca. 29 years; body mass index 22.7 kg/m2) were in­cluded in the study, and 24 completed the clinical part. The geometric mean ratios (test/reference) for the log-transformed AUC(0–t), AUC(0–∞), and Cmax were 95.16% (90% CI 92.52–97.87%), 95.08% (90% CI 92.40–97.83%), and 100.00% (90% CI 94.83–105.45%), respectively. There were no significant differences in the pharmacokinetic parameters between the test and reference formulations. No serious adverse events were reported.   Conclusions: The results of this single-dose study in healthy Caucasian volunteers indicate that Bisocard®; 2.5 mg film-coated tablets are bioequivalent to the reference product — Concor Cor 2.5®; 2.5 mg film-coated tablets. Both products had similar safety profile and have been well tolerated.