231 research outputs found
Influence of Yttrium Substitution on the Electronic Structure and Magnetic Moment of Gd7-xYxPd3 (x=0, 1, 2, 3, 4)
The electronic structure and magnetic properties of Gd7¡xYxPd3 (x = 0, 1, 2, 4) single crystals were
examined. These compounds crystallized in the same crystal structure type (Th7Fe3) with the same c=a ratio of
0.63. A strongly anisotropic behavior of the magnetic and transport properties was found. Magnetic frustration
and spin °uctuations on the palladium atoms are responsible for the complex magnetic properties of this ternary
compound. As a part of current research we presented further characteristic of the Gd7¡xYxPd3 (x = 0, 1, 2, 4)
single crystal
Electrocardiographic diagnosis of acute coronary syndromes in patients with left bundle branch block or paced rhythm
The population of patients with a pacemaker is constantly growing in number. Myocardial
infarction in these patients, like in patients with left bundle branch block (LBBB), is called the
undetermined type and characterizes the highest risk of death. Therefore the early and correct
diagnosis of AMI is very important. The electrocardiographic criteria of the recognition of
acute myocardial infarction (AMI) in patients with a ventricular pacing are similar to the
electrocardiographic criteria of the recognition of AMI in patients with LBBB. They are
applicable in the first phase of AMI’s diagnostic process and they are known as Sgarbossa’s
criteria. However, one should remember about differences between these two groups of patients
and therefore particular criteria have got different significance in patients from each group.
There are three Sgarbossa’s criteria: ST-segment elevation of ≥ 5 mm in the presence of
a negative QRS complex, ST-segment elevation of ≥ 1 mm in the presence of a positive QRS
complex and ST-segment depression of ≥ 1 mm in lead V1, V2 or V3. In spite of all limitations
of use ECG records in the recognition of AMI in patients with a ventricular pacing it should be
remembered, that this method (together with a typical medical history) is still the simplest, the
cheapest and the most available means of an early diagnosis of AMI. In patients with chest
pain, the presence of a pacemaker should not defer the execution of ECG recording because
ECG may be very helpful in establishing of the diagnosis. (Cardiol J 2007; 14: 207-213
Comparison of machine learning algorithms used to classify the asteroids observed by all-sky surveys
Context. Multifilter photometry from large sky surveys is commonly used to assign asteroid taxonomic types and study various problems in planetary science. To maximize the science output of those surveys, it is important to use methods that best link the spectro-photometric measurements to asteroid taxonomy. Aims. We aim to determine which machine learning methods are the most suitable for the taxonomic classification for various sky surveys. Methods. We utilized five machine learning supervised classifiers: logistic regression, naive Bayes, support vector machines (SVMs), gradient boosting, and MultiLayer Perceptrons (MLPs). Those methods were found to reproduce the Bus-DeMeo taxonomy at various rates depending on the set of filters used by each survey. We report several evaluation metrics for a comprehensive comparison (prediction accuracy, balanced accuracy, F1 score, and the Matthews correlation coefficient) for 11 surveys and space missions. Results. Among the methods analyzed, multilayer perception and gradient boosting achieved the highest accuracy and naive Bayes achieved the lowest accuracy in taxonomic prediction across all surveys. We found that selecting the right machine learning algorithm can improve the success rate by a factor of >2. The best balanced accuracy (similar to 85% for a taxonomic type prediction) was found for the Visible and Infrared Survey telescope for Astronomy (VISTA) and the ESA Euclid mission surveys where broadband filters best map the 1 mu m and 2 mu m olivine and pyroxene absorption bands. Conclusions. To achieve the highest accuracy in the taxonomic type prediction based on multifilter photometric measurements, we recommend the use of gradient boosting and MLP optimized for each survey. This can improve the overall success rate even when compared with naive Bayes. A merger of different datasets can further boost the prediction accuracy. For the combination of the Legacy Survey of Space and Time and VISTA survey, we achieved 90% for the taxonomic type prediction.Peer reviewe
Nieokreślony typ ostrego zespołu wieńcowego - rola elektrokardiogramu
Pacjenci ze stymulatorem serca stanowią coraz liczniejszą grupę. Zawał serca u tych osób,
podobnie jak u chorych z blokiem lewej odnogi pęczka Hisa (LBBB), należy do typu nieokreślonego
ostrego zespołu wieńcowego i wiąże się z największym ryzykiem nagłego zgonu, dlatego
tak ważne jest odpowiednio wczesne i prawidłowe jego rozpoznanie. Elektrokardiograficzne
kryteria rozpoznania ostrego zawału serca u pacjentów ze stymulacją komorową są w dużej
mierze zbieżne z kryteriami rozpoznania zawału u pacjentów z LBBB. Znajdują one zastosowanie
w pierwszym etapie procesu diagnostycznego ostrego zawału serca i znane są jako "kryteria Sgarbossy". Do "kryteriów Sgarbossy" należą: uniesienie odcinka ST większe lub
równe 5 mm przy ujemnym wychyleniu zespołów QRS, uniesienie odcinka ST większe lub
równe 1 mm przy dodatnim wychyleniu zespołów QRS oraz obniżenie odcinka ST większe lub
równe 1 mm w odprowadzeniach V1, V2 lub V3. Należy jednak pamiętać o specyficznych
różnicach miêdzy pacjentami ze stymulacją komorową a osobami z LBBB, które wskazują na
odmienne znaczenie poszczególnych kryteriów w obu grupach. Pomimo licznych ograniczeń
metody elektrokardiograficznej w rozpoznawaniu ostrego zawału serca u chorych ze stymulacją komorową należy pamiętać, że metoda ta nadal, wraz z typowym wywiadem, jest najprostszą, najtańszą i najbardziej dostępną formą wstępnej diagnostyki ostrego zawału serca.
(Folia Cardiologica Excerpta 2007; 2: 175-182
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Shotgun metagenomic analysis of microbial communities from the Loxahatchee nature preserve in the Florida Everglades.
BackgroundCurrently, much is unknown about the taxonomic diversity and the mechanisms of methane metabolism in the Florida Everglades ecosystem. The Loxahatchee National Wildlife Refuge is a section of the Florida Everglades that is almost entirely unstudied in regard to taxonomic profiling. This short report analyzes the metagenome of soil samples from this Refuge to investigate the predominant taxa, as well as the abundance of genes involved in environmentally significant metabolic pathways related to methane production (nitrogen fixation and dissimilatory sulfite reduction).MethodsShotgun metagenomic sequencing using the Illumina platform was performed on 17 soil samples from four different sites within the Loxahatchee National Wildlife Refuge, and underwent quality control, assembly, and annotation. The soil from each sample was tested for water content and concentrations of organic carbon and nitrogen.ResultsThe three most common phyla of bacteria for every site were Actinobacteria, Acidobacteria, and Proteobacteria; however, there was variation in relative phylum composition. The most common phylum of Archaea was Euryarchaeota for all sites. Alpha and beta diversity analyses indicated significant congruity in taxonomic diversity in most samples from Sites 1, 3, and 4 and negligible congruity between Site 2 and the other sites. Shotgun metagenomic sequencing revealed the presence of biogeochemical biomarkers of particular interest (e.g., mrcA, nifH, and dsrB) within the samples. The normalized abundances of mcrA, nifH, and dsrB exhibited a positive correlation with nitrogen concentration and water content, and a negative correlation with organic carbon concentration.ConclusionThis Everglades soil metagenomic study allowed examination of wetlands biological processes and showed expected correlations between measured organic constituents and prokaryotic gene frequency. Additionally, the taxonomic profile generated gives a basis for the diversity of prokaryotic microbial life throughout the Everglades
Impact of renal function on clinical outcomes after PCI in ACS and stable CAD patients treated with ticagrelor: a prespecified analysis of the GLOBAL LEADERS randomized clinical trial
Background: Impaired renal function (IRF) is associated with increased risks of both ischemic and bleeding events. Ticagrelor has been shown to provide greater absolute reduction in ischemic risk following acute coronary syndrome (ACS) in those with versus without IRF. Methods: A pre-specified sub-analysis of the randomized GLOBAL LEADERS trial (n = 15,991) comparing the experimental strategy of 23-month ticagrelor monotherapy (after 1-month ticagrelor and aspirin dual anti-platelet therapy [DAPT]) with 12-month DAPT followed by 12-month aspirin after percutaneous coronary intervention (PCI) in ACS and stable coronary artery disease (CAD) patients stratified according to IRF (glomerular filtration rate < 60 ml/min/1.73 m2). Results: At 2 years, patients with IRF (n = 2171) had a higher rate of the primary endpoint (all-cause mortality or centrally adjudicated, new Q-wave myocardial infarction [MI](hazard ratio [HR] 1.64, 95% confidence interval [CI] 1.35–1.98, padj = 0.001), all-cause death, site-reported MI, all revascularization and BARC 3 or 5 type bleeding, compared with patients without IRF. Among patients with IRF, there were similar rates of the primary endpoint (HR 0.82, 95% CI 0.61–1.11, p = 0.192, pint = 0.680) and BARC 3 or 5 type bleeding (HR 1.10, 95% CI 0.71–1.71, p = 0.656, pint = 0.506) in the experimental versus the reference group. No significant interactions were seen between IRF and treatment effect for any of the secondary outcome variables. Among ACS patients with IRF, there were no between-group differences in the rates of the primary endpoint or BARC 3 or 5 type bleeding; however, the rates of the patient-oriented composite endpoint (POCE) of all-cause death, any stroke, MI, or revascularization (pint = 0.028) and net adverse clinical events (POCE and BARC 3 or 5 type bleeding) (pint = 0.045), were lower in the experimental versus the reference group. No treatment effects were found in stable CAD patients categorized according to presence of IRF. Conclusions: IRF negatively impacted long-term prognosis after PCI. There were no differential treatment effects found with regard to all-cause death or new Q-wave MI after PCI in patients with IRF treated with ticagrelor monotherapy. Clinical trial regis
Retinal Degeneration Progression Changes Lentiviral Vector Cell Targeting in the Retina
In normal mice, the lentiviral vector (LV) is very efficient to target the RPE cells, but transduces retinal neurons well only during development. In the present study, the tropism of LV has been investigated in the degenerating retina of mice, knowing that the retina structure changes during degeneration. We postulated that the viral transduction would be increased by the alteration of the outer limiting membrane (OLM). Two different LV pseudotypes were tested using the VSVG and the Mokola envelopes, as well as two animal models of retinal degeneration: light-damaged Balb-C and Rhodopsin knockout (Rho-/-) mice. After light damage, the OLM is altered and no significant increase of the number of transduced photoreceptors can be obtained with a LV-VSVG-Rhop-GFP vector. In the Rho-/- mice, an alteration of the OLM was also observed, but the possibility of transducing photoreceptors was decreased, probably by ongoing gliosis. The use of a ubiquitous promoter allows better photoreceptor transduction, suggesting that photoreceptor-specific promoter activity changes during late stages of photoreceptor degeneration. However, the number of targeted photoreceptors remains low. In contrast, LV pseudotyped with the Mokola envelope allows a wide dispersion of the vector into the retina (corresponding to the injection bleb) with preferential targeting of Müller cells, a situation which does not occur in the wild-type retina. Mokola-pseudotyped lentiviral vectors may serve to engineer these glial cells to deliver secreted therapeutic factors to a diseased area of the retina
A Novel Adeno-Associated Viral Variant for Efficient and Selective Intravitreal Transduction of Rat Müller Cells
BACKGROUND:The pathologies of numerous retinal degenerative diseases can be attributed to a multitude of genetic factors, and individualized treatment options for afflicted patients are limited and cost-inefficient. In light of the shared neurodegenerative phenotype among these disorders, a safe and broad-based neuroprotective approach would be desirable to overcome these obstacles. As a result, gene delivery of secretable-neuroprotective factors to Müller cells, a type of retinal glia that contacts all classes of retinal neurons, represents an ideal approach to mediate protection of the entire retina through a simple and innocuous intraocular, or intravitreal, injection of an efficient vehicle such as an adeno-associated viral vector (AAV). Although several naturally occurring AAV variants have been isolated with a variety of tropisms, or cellular specificities, these vectors inefficiently infect Müller cells via intravitreal injection. METHODOLOGY/PRINCIPAL FINDINGS:We have previously applied directed evolution to create several novel AAV variants capable of efficient infection of both rat and human astrocytes through iterative selection of a panel of highly diverse AAV libraries. Here, in vivo and in vitro characterization of these isolated variants identifies a previously unreported AAV variant ShH10, closely related to AAV serotype 6 (AAV6), capable of efficient, selective Müller cell infection through intravitreal injection. Importantly, this new variant shows significantly improved transduction relative to AAV2 (>60%) and AAV6. CONCLUSIONS/SIGNIFICANCE:Our findings demonstrate that AAV is a highly versatile vector capable of powerful shifts in tropism from minor sequence changes. This isolated variant represents a new therapeutic vector to treat retinal degenerative diseases through secretion of neuroprotective factors from Müller cells as well as provides new opportunities to study their biological functions in the retina
An international collaborative evaluation of central serous chorioretinopathy: different therapeutic approaches and review of literature. The European Vitreoretinal Society central serous chorioretinopathy study
Purpose: To study and compare the efficacy of different therapeutic options for the treatment of central serous chorioretinopathy (CSCR). Methods: This is a nonrandomized, international multicentre study on 1719 patients (1861 eyes) diagnosed with CSCR, from 63 centres (24 countries). Reported data included different methods of treatment and both results of diagnostic examinations [fluorescein angiography and/or optical coherent tomography (OCT)] and best-corrected visual acuity (BCVA) before and after therapy. The duration of observation had a mean of 11 months but was extended in a minority of cases up to 7 years. The aim of this study is to evaluate the efficacy of the different therapeutic options of CSCR in terms of both visual (BCVA) and anatomic (OCT) improvement. Results: One thousand seven hundred nineteen patients (1861 eyes) diagnosed with CSCR were included. Treatments performed were nonsteroidal anti-inflammatory eye drops, laser photocoagulation, micropulse diode laser photocoagulation, photodynamic therapy (PDT; Standard PDT, Reduced-dose PDT, Reduced-fluence PDT), intravitreal (IVT) antivascular endothelial growth factor injection (VEGF), observation and other treatments. The list of the OTHERS included both combinations of the main proposed treatments or a variety of other treatments such as eplerenone, spironolactone, acetazolamide, beta-blockers, anti-anxiety drugs, aspirin, folic acid, methotrexate, statins, vitis vinifera extract medication and pars plana vitrectomy. The majority of the patients were men with a prevalence of 77%. The odds ratio (OR) showed a partial or complete resolution of fluid on OCT with any treatment as compared with observation. In univariate analysis, the anatomical result (improvement in subretinal fluid using OCT at 1 month) was favoured by age <60 years (p < 0.005), no previous observation (p < 0.0002), duration less than 3 months (p < 0.0001), absence of CSCR in the fellow eye (p = 0.04), leakage outside of the arcade (p = 0.05) and fluid height >500 \u3bcm (p = 0.03). The OR for obtaining partial or complete resolution showed that anti-VEGF and eyedrops were not statistically significant; whereas PDT (8.5), thermal laser (11.3) and micropulse laser (8.9) lead to better anatomical results with less variability. In univariate analysis, the functional result at 1 month was favoured by first episode (p = 0.04), height of subretinal fluid >500 \u3bcm (p < 0.0001) and short duration of observation (p = 0.02). Finally, there was no statistically significant difference among the treatments at 12 months. Conclusion: Spontaneous resolution has been described in a high percentage of patients. Laser (micropulse and thermal) and PDT seem to lead to significant early anatomical improvement; however, there is little change beyond the first month of treatment. The real visual benefit needs further clarification
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