195 research outputs found

    A sparsity-based framework for resolution enhancement in optical fault analysis of integrated circuits

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    The increasing density and smaller length scales in integrated circuits (ICs) create resolution challenges for optical failure analysis techniques. Due to flip-chip bonding and dense metal layers on the front side, optical analysis of ICs is restricted to backside imaging through the silicon substrate, which limits the spatial resolution due to the minimum wavelength of transmission and refraction at the planar interface. The state-of-the-art backside analysis approach is to use aplanatic solid immersion lenses in order to achieve the highest possible numerical aperture of the imaging system. Signal processing algorithms are essential to complement the optical microscopy efforts to increase resolution through hardware modifications in order to meet the resolution requirements of new IC technologies. The focus of this thesis is the development of sparsity-based image reconstruction techniques to improve resolution of static IC images and dynamic optical measurements of device activity. A physics-based observation model is exploited in order to take advantage of polarization diversity in high numerical aperture systems. Multiple-polarization observation data are combined to produce a single enhanced image with higher resolution. In the static IC image case, two sparsity paradigms are considered. The first approach, referred to as analysis-based sparsity, creates enhanced resolution imagery by solving a linear inverse problem while enforcing sparsity through non-quadratic regularization functionals appropriate to IC features. The second approach, termed synthesis-based sparsity, is based on sparse representations with respect to overcomplete dictionaries. The domain of IC imaging is particularly suitable for the application of overcomplete dictionaries because the images are highly structured; they contain predictable building blocks derivable from the corresponding computer-aided design layouts. This structure provides a strong and natural a-priori dictionary for image reconstruction. In the dynamic case, an extension of the synthesis-based sparsity paradigm is formulated. Spatial regions of active areas with the same behavior over time or over frequency are coupled by an overcomplete dictionary consisting of space-time or space-frequency blocks. This extended dictionary enables resolution improvement through sparse representation of dynamic measurements. Additionally, extensions to darkfield subsurface microscopy of ICs and focus determination based on image stacks are provided. The resolution improvement ability of the proposed methods has been validated on both simulated and experimental data

    Kontekstualizirati Karaburun: Novo območje raziskav neolitika v Anatoliji

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    Recent surveys led by the author in Karaburun Peninsula discovered multiple prehistoric sites. This article introduces one of the Neolithic sites called Kömür Burnu in this marginal zone of coastal western Anatolia. The site offered various advantages to early farmer-herders including freshwater and basalt sources as well as proximity to agricultural lands, forested areas and marine resources. The plain slipped pottery from the site suggests a date between 6200-6000 cal. BC for the Neolithic occupation. P-XRF characterization of obsidian pieces from Kömür Burnu revealed that these were acquired from two different sources (Melos-Adamas and Göllüdağ). These constitute the first evidence for the participation of Karaburun early farmer-herders in the exchange networks that were active in Neolithic Anatolia and the Aegean. The differential technological features of these pieces concur well with the dual obsidian mobility model suggested by M. Milić for the western Anatolian Neolithic. Univerza Ege je nedavno izvedla površinske preglede na polotoku Karaburun, ki se na­haja na obalnem predelu v zahodni Anatoliji, in odkrila številna nova prazgodovinska najdišča. V članku predstavljamo eno od neolitskih najdišč, in sicer najdišče Komur Burni. Najdišče se nahaja na območju, ki je bilo ugodno za poselitev prvih poljedelcev in živinorejcev, saj ima dostop do sveže pitne vode, do naravnih surovin (bazalt) in do kmetijskih površin, gozda in morja. Materialna kultura kaže, da je bilo to območje poseljeno ok. 6200–6000 pr. n. št. Analiza P-XRF je pokazala, da so obsidian iz najdišča Komur Burnu pridobivali iz dveh geografskih območij (Melos-Adamas in Golludag). To je prvi dokaz o tem, da so bili prvi poljedelci in živinorejci na polotoku Karaburun v času neolitika že vključeni v sistem menjav med Anatolijo in otoki v Egejskem morju. Predvsem je opazno, da lahko te najdbe na podlagi njihovih različnih tehnoloških značilnosti dobro umestimo v model dvojne mobilnosti obsidiana kot ga je predlagala Marina Milić za zahodno Anatolijo v času neolitika

    Exploring Environments

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    My search for creative inspiration often leads to explorations in natural and built environments. Being physically immersed in an environment offers endless vantage points, as well as points of focus; allowing all senses to function as receptors of surrounding data. Observations stimulate thoughts and ideas, which inspire experiments. Projects are born, sometimes out of the smallest details. In a series of projects I explore the possibilities of using physical environments as primary source of inspiration and input in the creation of tools that function in design contexts

    Contextualizing Karaburun A New Area for Neolithic Research in Anatolia

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    Recent surveys led by the author in Karaburun Peninsula discovered multiple prehistoric sites. This article introduces one of the Neolithic sites called Kömür Burnu in this marginal zone of coastal western Anatolia. The site offered various advantages to early farmer-herders including freshwater and basalt sources as well as proximity to agricultural lands, forested areas and marine resources. The plain slipped pottery from the site suggests a date between 6200-6000 cal. BC for the Neolithic occupation. P-XRF characterization of obsidian pieces from Kömür Burnu revealed that these were acquired from two different sources (Melos-Adamas and Göllüdağ). These constitute the first evidence for the participation of Karaburun early farmer-herders in the exchange networks that were active in Neolithic Anatolia and the Aegean. The differential technological features of these pieces concur well with the dual obsidian mobility model suggested by M. Milić for the western Anatolian Neolithic

    Temporal Trends and Outcomes of Acute Myocardial Infarction in Patients With Cancer

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    Background: Data on outcomes of ST-elevation myocardial infarction (STEMI) in patients with cancer are scarce. We investigated the nationwide trends in admissions for STEMI, utilization of percutaneous coronary intervention (PCI), and in-hospital outcomes in patients with the three most common cancer diagnoses (lung, breast, and colon) compared to patients without cancer. Methods: We conducted an administrative database study using the Nationwide Inpatient Sample (NIS). All in-patient hospitalizations for STEMI from 2001 to 2011 were identified. Patients with concomitant diagnosis of lung, breast or colon cancer were identified using appropriate International classification of diagnosis (ICD 9-CM) codes. Primary outcome was utilization of PCI and in-hospital mortality in patients with cancer compared to those without cancer. Results: Utilization of PCI was 30.8% (1,191/3,871), 20.2% (4,541/22,480) and 17.3% (1,716/9,944) in patients with breast, lung and colon cancer, respectively. Among patients without any of these cancers, use of PCI was 49.6%. In-hospital mortality was highest in patients with lung cancer (57.1%) and lowest in patients without cancer (25.7%). Conclusions: Patients with cancer have significantly worse in-hospital mortality compared to those without cancer, partly due to a relatively lower rate of PCI utilization in cancer patients with STEMI

    Spontaneous left main coronary artery dissection complicated by pseudoaneurysm formation in pregnancy: role of CT coronary angiography

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    We report a case of a 26-year-old female, who presented at 34 weeks of an uncomplicated pregnancy with an acute ST elevation anterior wall myocardial infarction. Cardiac catheterization suggested a left main coronary artery dissection with pseudoaneurysm formation. The patient's course was complicated by congestive heart failure. She was initially managed conservatively by a multidisciplinary team including heart failure specialists, obstetricians, and cardiovascular surgeons. 4 days after admission, her LMC was imaged by dual-source 64 slice Cardiac computed tomography, coronary dissection was identified extending to the lumen, and the presence of pseudoaneurysm was confirmed. She underwent subsequently a staged procedure, which included placement of an intra-aortic balloon pump, cesarean section, and coronary artery bypass grafting. This case illustrates the utility of coronary artery CT imaging to assess the complexity and stability of coronary artery dissections, thereby helping to determine the need for, and timing of revascularization procedures

    Early farmers from across Europe directly descended from Neolithic Aegeans

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    Farming and sedentism first appeared in southwestern Asia during the early Holocene and later spread to neighboring regions, including Europe, along multiple dispersal routes. Conspicuous uncertainties remain about the relative roles of migration, cultural diffusion, and admixture with local foragers in the early Neolithization of Europe. Here we present paleogenomic data for five Neolithic individuals from northern Greece and northwestern Turkey spanning the time and region of the earliest spread of farming into Europe. We use a novel approach to recalibrate raw reads and call genotypes from ancient DNA and observe striking genetic similarity both among Aegean early farmers and with those from across Europe. Our study demonstrates a direct genetic link between Mediterranean and Central European early farmers and those of Greece and Anatolia, extending the European Neolithic migratory chain all the way back to southwestern Asia

    Candidate genetic analysis of plasma high-density lipoprotein-cholesterol and severity of coronary atherosclerosis

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    <p>Abstract</p> <p>Background</p> <p>Plasma level of high-density lipoprotein-cholesterol (HDL-C), a heritable trait, is an important determinant of susceptibility to atherosclerosis. Non-synonymous and regulatory single nucleotide polymorphisms (SNPs) in genes implicated in HDL-C synthesis and metabolism are likely to influence plasma HDL-C, apolipoprotein A-I (apo A-I) levels and severity of coronary atherosclerosis.</p> <p>Methods</p> <p>We genotyped 784 unrelated Caucasian individuals from two sets of populations (Lipoprotein and Coronary Atherosclerosis Study- LCAS, N = 333 and TexGen, N = 451) for 94 SNPs in 42 candidate genes by 5' nuclease assays. We tested the distribution of the phenotypes by the Shapiro-Wilk normality test. We used Box-Cox regression to analyze associations of the non-normally distributed phenotypes (plasma HDL-C and apo A-I levels) with the genotypes. We included sex, age, body mass index (BMI), diabetes mellitus (DM), and cigarette smoking as covariates. We calculated the q values as indicators of the false positive discovery rate (FDR).</p> <p>Results</p> <p>Plasma HDL-C levels were associated with sex (higher in females), BMI (inversely), smoking (lower in smokers), DM (lower in those with DM) and SNPs in <it>APOA5, APOC2</it>, <it>CETP, LPL </it>and <it>LIPC </it>(each q ≤0.01). Likewise, plasma apo A-I levels, available in the LCAS subset, were associated with SNPs in <it>CETP</it>, <it>APOA5</it>, and <it>APOC2 </it>as well as with BMI, sex and age (all q values ≤0.03). The <it>APOA5 </it>variant S19W was also associated with minimal lumen diameter (MLD) of coronary atherosclerotic lesions, a quantitative index of severity of coronary atherosclerosis (q = 0.018); mean number of coronary artery occlusions (p = 0.034) at the baseline and progression of coronary atherosclerosis, as indicated by the loss of MLD.</p> <p>Conclusion</p> <p>Putatively functional variants of <it>APOA2</it>, <it>APOA5, APOC2</it>, <it>CETP, LPL</it>, <it>LIPC </it>and <it>SOAT2 </it>are independent genetic determinants of plasma HDL-C levels. The non-synonymous S19W SNP in <it>APOA5 </it>is also an independent determinant of plasma apo A-I level, severity of coronary atherosclerosis and its progression.</p

    Coronary stent healing in cancer patients: an optical coherence tomography perspective

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    Objective: This study assessed stent healing patterns and cardiovascular outcomes by optical coherence tomography (OCT) in cancer patients after drug-eluting stent (DES) placement.Background: Cancer treatment, owing to its cytotoxic and antiproliferative effects, could delay stent healing and increase stent thrombosis risk, especially when dual antiplatelet therapy (DAPT) is discontinued early for oncological treatment. OCT can assess stent endothelialization and other healing parameters, which may provide clinical guidance in these challenging scenarios.Methods: This single-center retrospective study enrolled all cancer patients who underwent OCT for assessment of vascular healing patterns after prior DES placement from November 2009 to November 2018. Primary study endpoints were stent healing parameters, including stent coverage, apposition, degree of expansion, neointimal hyperplasia heterogeneity, in-stent restenosis, stent thrombosis, and overall survival (OS).Results: A total of 67 patients were included in this study. Mean time between DES placement and OCT evaluation was 154 +/- 82 days. Stent healing matched published values for DES in non-cancer patients (P >= 0.063). At 1 year, the OS was 86% (95% confidence interval [CI]: 78-96%) with 0% incidence of acute coronary syndrome. Advanced cancers and active chemotherapies were associated with inferior OS (P = 0.024, hazard ratio [HR]: 3.50, 95% CI: 1.18-10.42 and P = 0.026, HR: 2.65, 95% CI: 1.13-6.22, respectively), while stent healing parameters were unassociated with OS. Forty-one patients (61%) had DAPT duration <= 6 months.Conclusions: Stent healing of contemporary DES appears similar in cancer and non-cancer patients. Cardiovascular risk of cancer patients after DES placement can be managed to facilitate timely cancer therapies, as the underlying malignancy and active chemotherapy ultimately determine survival.Cardiovascular Aspects of Radiolog

    Health, Globalization And Developing Countries

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    In health care today, scientific and technological frontiers are expanding at unprecedented rates, even as economic and financial pressures shrink profit margins, intensify competition, and constrain the funds available for investment. Therefore, the world today has more economic, and social opportunities for people than 10 or 100 years since globalization has created a new ground somewhat characterized by rapid economic transformation, deregulation of national markets by new trade regimes, amazing transport, electronic communication possibilities and high turnover of foreign investment and capital flow as well as skilled labor. These trends can easily mask great inequalities in developing countries such as importation and spreading of infectious and non-communicable diseases; miniaturization of movement of medical technology; health sector trades management driven by economics without consideration to the social and health aspects and its effects, increasing health inequalities and their economic and social burden creation; multinational companies' cheap labor employment promotion in widening income differentials; and others. As a matter of fact, all these factors are major determinants of ill health. Health authorities of developing countries have to strengthen their regulatory framework in order to ensure that national health systems derive maximum benefit in terms of equity, quality and efficiency, while reducing potential social cost to a minimum generated risky side of globalization.Wo
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