Statistical classification of soft solder alloys by laser-induced breakdown spectroscopy: review of methods

This paper reviews machine-learning methods that are nowadays the most frequently used for the supervised classification of spectral signals in laser-induced breakdown spectroscopy (LIBS). We analyze and compare various statistical classification methods, such as linear discriminant analysis (LDA), quadratic discriminant analysis (QDA), partial least-squares discriminant analysis (PLS-DA), soft independent modeling of class analogy (SIMCA), support vector machine (SVM), naive Bayes method, probabilistic neural networks (PNN), and K-nearest neighbor (KNN) method. The theoretical considerations are supported with experiments conducted for real soft-solder-alloy spectra obtained using LIBS. We consider two decision problems: binary and multiclass classification. The former is used to distinguish overheated soft solders from their normal versions. The latter aims to assign a testing sample to a given group of materials. The measurements are obtained for several laser-energy values, projection masks, and numbers of laser shots. Using cross-validation, we evaluate the above classification methods in terms of their usefulness in solving both classification problems

242. Analiza ekspresji EGFR i angiogenezv w utkaniu niedrobnokomórkowego raka płuc oraz związku z czasem przeżycia pacjentów w stadiach zaawansowania klinicznego I-IIIA

Cel pracyWciąż niezadowalające wskaźniki przeżycia pacjentów z rakiem płuca, mimo radykalnego leczenia operacyjnego, skłaniają do poszukiwań nowych czynników prognostycznych. Wiadomym jest, że receptor naskórkowego czynnika wzrostu (EGFR) wpływa na wzrost komórek guza i jego progresję, jak również tworzenie przerzutów – głównie poprzez oddziaływanie na tworzenie nowych naczyń krwionośnych. Jego prognostyczna rola u pacjentów z niedrobnokomórkowym rakiem płuca (NRP) jest niejasna. Natomiast gęstość naczyń krwionośnych (GNK), będąca miernikiem angiogenezy w guzie, jest podawana jako marker prognostyczny w wielu nowotworach. Celem naszego badania była ocena zależności między ekspresją EGFR i GNK w utkaniu guza nowotworowego a przeżyciem pacjentów z NRP.Materiał i metodyBadaniem objęto 75 pacjentów z NRP w stadiach zaawansowania klinicznego I-IIIA. Wycinki z guza pobierano z materiału operacyjnego, utrwalonego w formalinie. Na uzyskanych skrawkach parafinowych wykonywano odczyny immunohistochemiczne z zastosowaniem monoklonalnego przeciwciała przeciw receptorowi naskórkowego czynnika wzrostu oraz monoklonalnego przeciwciała przeciw CD31.WynikiWśród 75 pacjentów było 5 kobiet (6.7%) i 70 mężczyzn (93.3%) w wieku od 42 lat do 74 lat (średnio 59 lat). W badanej grupie chorych stwierdzono raka płaskonabłonkowego u 53 pacjentów (70.7%), gruczolakoraka u 11 chorych (14.7%) i raka wielkokomórkowego także u 11 pacjentów. Analizując uzyskane dane nie stwierdzono istotności statystycznej między ekspresją EGFR i czasem przeżycia pacjentów. Również GNK nie miała istotnego wpływu na przeżycie pacjentów. Jedynie stan węzłów chłonnych (cecha N; p<0.05), typ histologiczny raka (p<0.001) oraz wiek (p<0.05) w badanej grupie chorych miały istotny statystycznie wpływ na czas przeżycia.WnioskiUzyskane w tym badaniu wyniki nie są zgodne z wynikami innych doniesień mówiących o tym, że ekspresja EGFR i GNK w NRP mogą być traktowane jako czynniki prognostyczne. Należy jednak podkreślić, że analizowana grupa pacjentów była mała, a większość chorych (59 pacjentów, 78.7%) znajdowała się w stadium znacznego zaawansowania nowotworu

Structure of Fe-Cu coatings prepared by the magnetron sputtering method

This work presents the results of our research concerning the synthesis of metallic Fe-Cu coatings by use of the magnetron sputtering method. The structure of the coatings synthesized during two modes of pulsed magnetron sputtering was compared . In our experiment the pulsed magnetron power supply generated a series of pulses gated at 1kHz - standard pulsed mode (SPM) and 2 Hz - low frequency pulsed mode (LFPM). The analysis of the microstructure by means of SEM and TEM show that obtained coatings are characterized by nanocrystalline structure. Additionally the optical emission spectra (OES) during the copper and iron sputtering were measured

Determination of sp³ fraction in ta-C coating using XPS and Raman spectroscopy

The paper presents results of studies on the structure of tetrahedral amorphous carbon films (ta-C) with a thickness in the range from 20 to 280 nm, deposited using pulsed vacuum arc technique with an electromagnetic Venetian blind plasma filter. The results of the phase structure analysis, obtained using visible Raman spectroscopy and UV Raman spectroscopy methods, showed a strong dependence of the results on the presence, on the surface of synthesized thin carbon films, even of a minimum number of microparticles. The presence of microparticles in the deposited coatings strongly affects the accuracy of the measured data, used next for calculation the ID/IG, IT/IG ratios and determination of the G-peak dispersion, for all coating thicknesses, which pointed to significant diversification in sp³ -bonds content in deposited films.Представлены результаты исследования структуры тетраэдральных аморфных углеродных пленок (tа-С) толщиной в интервале 20…280 нм, осажденных методом импульсной вакуумной дуги с электромагнитным жалюзи плазменного фильтра. Результаты фазово-структурного анализа, полученные методами спектроскопии комбинационного рассеяния света в видимом и УФ-диапазонах, демонстрируют сильную зависимость результатов от наличия на поверхности тонких углеродных пленок микрочастиц даже в минимальном количестве. Присутствие микрочастиц в осажденных покрытиях сильно влияет на точность измеренных данных, используемых далее для вычисления соотношений ID/IG, IT/IG и определения дисперсии G-пика для покрытий всех толщин, что приводит к значительному разбросу данных при оценке связей в осажденных пленках.Представлені результати дослідження структури тетраедральних аморфних вуглецевих плівок (tа-С) завтовшки в інтервалі 20…280 нм, осаджених методом імпульсної вакуумної дуги з електромагнітним жалюзі плазмового фільтра. Результати фазово-структурного аналізу, що отримані методами спектроскопії комбінаційного розсіяння світла у видимому і УФ-діапазонах, демонструють велику залежність результатів від наявності на поверхні тонких вуглецевих плівок мікрочасток навіть у мінімальній кількості. Присутність мікрочасток в осаджених покриттях дуже впливає на точність виміряних даних, що використовувалися для обчислення співвідношень ID/IG, IT/IG і визначення дисперсії G-піка для покриттів усієї товщини, що призводить до значного розкиду даних при оцінці зв'язків в осаджених плівках

Comparison of GPS analysis strategies for high-accuracy vertical land motion

Tide gauges measure sea level changes relative to land. To separate absolute changes in sea level from vertical land movements tide gauges are often co-located with Continuous GPS (CGPS). In order to achieve an accuracy of better than 1 mm/yr, as required for sea level studies in the global change context, vertical land motion needs to be determined with the same accuracy. This is an ambitious goal for CGPS and needs a carefully designed analysis strategy. We have compared the independent results from six different analysis centres, using three different GPS processing softwares and a number of different analysis strategies. Based on the comparison, we discuss the achieved accuracy and the quality of the different strategies. The data analysed are from the CGPS network of the European Sea Level Service and cover the time window from the beginning of 2000 until the end of 2003. The comparison reveals large differences in the day-to-day variations of the coordinate time series and also in the seasonal cycle contained in these. The trends show systematic differences, depending on software and strategy used. To a large extent, the latter deviations can be explained by differences in the realisation of the reference frame, while some parts may be due to other, as yet, unidentified contributions. The results suggest that the reference frame and its relation to the center of mass of the Earth system may be the main limitation in achieving the accuracy goal for the secular velocity of vertical land motion.Peer ReviewedPostprint (published version

Deletion of SA β-Gal+ Cells Using Senolytics Improves Muscle Regeneration in Old Mice

Systemic deletion of senescent cells leads to robust improvements in cognitive, cardiovascular, and whole-body metabolism, but their role in tissue reparative processes is incompletely understood. We hypothesized that senolytic drugs would enhance regeneration in aged skeletal muscle. Young (3 months) and old (20 months) male C57Bl/6J mice were administered the senolytics dasatinib (5 mg/kg) and quercetin (50 mg/kg) or vehicle bi-weekly for 4 months. Tibialis anterior (TA) was then injected with 1.2% BaCl2 or PBS 7- or 28 days prior to euthanization. Senescence-associated β-Galactosidase positive (SA β-Gal+) cell abundance was low in muscle from both young and old mice and increased similarly 7 days following injury in both age groups, with no effect of D+Q. Most SA β-Gal+ cells were also CD11b+ in young and old mice 7- and 14 days following injury, suggesting they are infiltrating immune cells. By 14 days, SA β-Gal+/CD11b+ cells from old mice expressed senescence genes, whereas those from young mice expressed higher levels of genes characteristic of anti-inflammatory macrophages. SA β-Gal+ cells remained elevated in old compared to young mice 28 days following injury, which were reduced by D+Q only in the old mice. In D+Q-treated old mice, muscle regenerated following injury to a greater extent compared to vehicle-treated old mice, having larger fiber cross-sectional area after 28 days. Conversely, D+Q blunted regeneration in young mice. In vitro experiments suggested D+Q directly improve myogenic progenitor cell proliferation. Enhanced physical function and improved muscle regeneration demonstrate that senolytics have beneficial effects only in old mice

Deconvolution of Serum Cortisol Levels by Using Compressed Sensing

The pulsatile release of cortisol from the adrenal glands is controlled by a hierarchical system that involves corticotropin releasing hormone (CRH) from the hypothalamus, adrenocorticotropin hormone (ACTH) from the pituitary, and cortisol from the adrenal glands. Determining the number, timing, and amplitude of the cortisol secretory events and recovering the infusion and clearance rates from serial measurements of serum cortisol levels is a challenging problem. Despite many years of work on this problem, a complete satisfactory solution has been elusive. We formulate this question as a non-convex optimization problem, and solve it using a coordinate descent algorithm that has a principled combination of (i) compressed sensing for recovering the amplitude and timing of the secretory events, and (ii) generalized cross validation for choosing the regularization parameter. Using only the observed serum cortisol levels, we model cortisol secretion from the adrenal glands using a second-order linear differential equation with pulsatile inputs that represent cortisol pulses released in response to pulses of ACTH. Using our algorithm and the assumption that the number of pulses is between 15 to 22 pulses over 24 hours, we successfully deconvolve both simulated datasets and actual 24-hr serum cortisol datasets sampled every 10 minutes from 10 healthy women. Assuming a one-minute resolution for the secretory events, we obtain physiologically plausible timings and amplitudes of each cortisol secretory event with R[superscript 2] above 0.92. Identification of the amplitude and timing of pulsatile hormone release allows (i) quantifying of normal and abnormal secretion patterns towards the goal of understanding pathological neuroendocrine states, and (ii) potentially designing optimal approaches for treating hormonal disorders.National Science Foundation (U.S.). Graduate Research Fellowship ProgramNational Institutes of Health (U.S.) (NIH DP1 OD003646)National Science Foundation (U.S.) (0836720)National Science Foundation (U.S.). Office of Emerging Frontiers in Research and Innovation (EFRI-0735956

High sensitive troponin T and heart fatty acid binding protein: Novel biomarker in heart failure with normal ejection fraction?: A cross-sectional study

Background: High sensitive troponin T (hsTnT) and heart fatty acid binding protein (hFABP) are both markers of myocardial injury and predict adverse outcome in patients with systolic heart failure (SHF). We tested whether hsTnT and hFABP plasma levels are elevated in patients with heart failure with normal ejection fraction (HFnEF). Methods: We analyzed hsTnT, hFABP and N-terminal brain natriuretic peptide in 130 patients comprising 49 HFnEF patients, 51 patients with asymptomatic left ventricular diastolic dysfunction (LVDD), and 30 controls with normal diastolic function. Patients were classified to have HFnEF when the diagnostic criteria as recommended by the European Society of Cardiology were met. Results: Levels of hs TnT and hFABP were significantly higher in patients with asymptomatic LVDD and HFnEF (both p < 0.001) compared to controls. The hsTnT levels were 5.6 [0.0-9.8] pg/ml in LVDD vs. 8.5 [3.9-17.5] pg/ml in HFnEF vs. < 0.03 [< 0.03-6.4] pg/ml in controls; hFABP levels were 3029 [2533-3761] pg/ml in LVDD vs. 3669 [2918-4839] pg/ml in HFnEF vs. 2361 [1860-3081] pg/ml in controls. Furthermore, hsTnT and hFABP levels were higher in subjects with HFnEF compared to LVDD (p = 0.015 and p = 0.022). Conclusion: In HFnEF patients, hsTnT and hFABP are elevated independent of coronary artery disease, suggesting that ongoing myocardial damage plays a critical role in the pathophysiology. A combination of biomarkers and echocardiographic parameters might improve diagnostic accuracy and risk stratification of patients with HFnEF