Site-controlled Ag nanocrystals grown by molecular beam epitaxy-Towards plasmonic integration technology

We demonstrate site-controlled growth of epitaxial Ag nanocrystals on patterned GaAs substrates by molecular beam epitaxy with high degree of long-range uniformity. The alignment is based on lithographically defined holes in which position controlled InAs quantum dots are grown. The Ag nanocrystals self-align preferentially on top of the InAs quantum dots. No such ordering is observed in the absence of InAs quantum dots, proving that the ordering is strain-driven. The presented technique facilitates the placement of active plasmonic nanostructures at arbitrarily defined positions enabling their integration into complex devices and plasmonic circuits

Epitaxial self-alignment: A new route to hybrid active plasmonic nanostructures

Concepts of lateral ordering of epitaxial semiconductor quantum dots (QDs) are for the first time transferred to hybrid nanostructures for active plasmonics. We review our recent research on the self-alignment of epitaxial nanocrystals of In and Ag on ordered one-dimensional In(Ga)As QD arrays and isolated QDs by molecular beam epitaxy. By changing the growth conditions the size and density of the metal nanocrystals are easily controlled and the surface plasmon resonance wavelength is tuned over a wide range in order to match the emission wavelength of the QDs. Photoluminescence measurements reveal large enhancement of the emitted light intensity due to plasmon enhanced emission and absorption down to the single QD level

Low-density InAs QDs with subcritical coverage obtained by conversion of In nanocrystals

We report growth of InAs/GaAs quantum dots (QDs) by molecular beam epitaxy with low density of 2 μm−2 by conversion of In nanocrystals deposited at low temperatures. The total amount of InAs used is about one monolayer, which is less than the critical thickness for conventional Stranski–Krastanov QDs. We also demonstrate the importance of the starting surface reconstruction for obtaining uniform QDs. The QD emission wavelength is easily tunable upon post-growth annealing with no wetting layer signal visible for short anneals. Microphotoluminescence measurements reveal well separated and sharp emission lines of individual QDs

Microstructure and mechanical properties of HR6W alloy dedicated for manufacturing of pressure elements in supercritical and ultrasupercritical power units

The article presents the results of research on the microstructure and selected mechanical properties of HR6W nickel-base alloy. The test alloy was subjected to isothermal ageing at 700°C and for up to 10000h. The tests of the HR6W microstructure were performed using the scanning electron microscopy (SEM) and the transmission electron microscopy (TEM). The performed microstructural tests of the HR6W alloy showed that in the as-received condition it was characterised by the structure of nickel austenite with numerous primary precipitates of NbC and TiN. Ageing of the investigated alloy contributed to the precipitation of numerous particles of varying morphologies inside the grains and at the grain boundaries, as well as at the boundaries of twins - they were the secondary precipitates of M23C6 and Laves phase. The number of the particles precipitated at the boundaries was so large that they formed the so-called continuous grid of precipitates. Inside the grains, the presence of compound complexes of precipitates was observed. These complexes consisted of the TiN particles, as well as the M23C6 carbides and Laves phase nucleating on them. The tests of the mechanical properties of HR6W alloy showed that in the as-received condition the alloy showed high plastic properties, with relatively low strength properties - in particular, the yield strength. Ageing of the HR6W alloy, as a result of precipitation of numerous particles in the matrix, through the strengthening with the precipitation mechanism, resulted in a considerable growth of the strength properties - inter alia the yield strength by over 60%, with the reduction of the plastic properties - elongation decreased by around 40%. Similar growth in the test alloy was observed for hardness

Laparoscopic Anderson-Hynes procedure as a treatment of ureteropelvic junction obstruction caused by fibroepithelial polyp

Fibroepithelial polyps (FEPs) are rare benign ureteral neoplasms of mesodermal origin. As an intrinsic cause of ureteropelvic junction obstruction (UPJO) they are very uncommon. Excretory urography and diuretic renography used by many urologists to diagnose a UPJO may not detect the ureteral polyp. We present a case of ureteropelvic junction obstruction caused by a fibroepithelial polyp, which was not diagnosed preoperatively. The patient underwent successful laparoscopic excision of the polyp with Anderson-Hynes pyeloplasty. We believe that laparoscopy is a useful, minimally invasive operative technique in the treatment of FEPs and may be considered a procedure of choice in large polyps, in which cases the endoscopic procedure is difficult or impossible to perform

Clinical Outcomes of Extracranial Carotid Artery-Related Stroke Eligible for Mechanical Reperfusion on Top of Per-Guidelines Thrombolytic Therapy:Analysis from a 6-Month Consecutive Patient Sample in 2 Centers

BACKGROUND: Systemic intravenous thrombolysis and mechanical thrombectomy (MT) are guideline-recommended reperfusion therapies in large-vessel-occlusion ischemic stroke. However, for acute ischemic stroke of extracranial carotid artery origin (AIS-CA) there have been no specific trials, resulting in a data gap. MATERIAL/METHODS: We evaluated referral/treatment pathways, serial imaging, and neurologic 90-day outcomes in consecutive patients, presenting in a real-life series in 2 stroke centers over a period of 6 months, with AIS-CA eligible for emergency mechanical reperfusion (EMR) on top of thrombolysis as per guideline criteria. RESULTS: Of 30 EMR-eligible patients (33.3% in-window for thrombolysis and thrombolysed, 73.3% male, age 39-87 years, median Alberta Stroke Program Early Computed Tomography Score (ASPECTS) 10, pre-stroke mRS 0–1 in all, tandem lesions 26.7%), 20 (66.7%) were EMR-referred (60% – endovascular, 6.7% – surgery referrals). Only 40% received EMR, nearly exclusively in stroke centers with carotid artery stenting (CAS) expertise (100% eligible patient acceptance rate, 100% treatment delivery involving CAS±MT with culprit lesion sequestration using micronet-covered stents). The emergency surgery rate was 0%. Baseline clinical and imaging characteristics did not differ between EMR-treated and EMR-untreated patients. Ninety-day neurologic status was profoundly better in EMR-treated patients: mRS 0–2 (91.7% vs 0%; P<0.001); mRS 3–5 (8.3% vs 88.9%; P<0.001), mRS 6 (0% vs 11.1%; P<0.001). CONCLUSIONS: In a real-life AIS-CA setting, the referral rate of EMR-eligible patients for EMR was low, and the treatment rate was even lower. AIS-CA revascularization was delivered predominantly in stroke thrombectomy-capable cardioangiology centers, resulting in overwhelmingly superior patient outcome. Large vessel occlusion stroke referral and management pathways should involve centers with proximal-protected CAS expertise. AIS-CA, irrespective of any thrombolysis administration, is a hyperacute cerebral emergency and EMR-eligible patients should be immediately referred for mechanical reperfusion

Sen, marzenie, zaświaty w literaturze i kulturze: Tom 2. Kultura

Poddane oglądowi obiekty reprezentują zróżnicowane gatunki/formy wypowiedzi – od dramatów, poprzez inscenizacje, powieści, eseje, nowele, małe traktaty filozoficzne, pamiętniki, ankiety, wywiady i wiersze opisujące zjawiska oniryczne z perspektywy psychologii. Sen i zaświaty jawią się też jako przestrzeń chętnie zagospodarowywana z zachowaniem optyki religijnej, bez niej albo wręcz wbrew niej. Wszystkie te wizje podporządkowane są przekonaniu o istnieniu sił dobra i zła, które toczą z sobą nieustanny bój. W jego centrum sytuuje się człowiek. To zmagania ducha i materii, próby uchwycenia za pomocą doświadczenia mistycznego, lub bez niego, momentu przejścia od życia do śmierci i ze śmierci do życia. Umysł ludzki, postrzegany w zgromadzonych w tomie tekstach jako posiadający – zdawać by się mogło – nieograniczone możliwości, gdy w grę wchodzi doświadczanie mistycznych doznań Absolutu oraz kreowanie równoległych światów za sprawą wyobraźni, tworzywa artystycznego czy filozofii, zarazem odsłania ograniczenia, jakie niesie choroba (afazja) i starość (bliskość nieuchronnej śmierci). Psychologia, obok filozofii, jawi się jako królowa nauk, która potrafi dość głęboko wniknąć i zadowalająco wyjaśnić sens sennego marzenia, poznać oniryczną wizję i towarzyszyć podczas odwiedzin zaświatów. Zawartość niniejszego tomu może być pomocna w ustaleniu, czego człowiek poszukuje we śnie. Ukazuje również wyjątkową siłę snu jako środka pozwalającego ludzkiej jaźni wydostać się ze świata jawy, by penetrować obszary niedostępne. Z kolei za sprawą instrumentarium dramatu przybliża odbiorcy wizję wytworzoną przez dramaturgów i reżyserów. Sen stanowi przepustkę w zaświaty dla takich wizjonerów, jak Pilch, Sapkowski, Hofmannsthal oraz służy mówieniu o kondycji człowieka i jego skrytych problemach