617 research outputs found
Superposition of photon- and phonon- assisted tunneling in coupled quantum dots
We report on electron transport through an artificial molecule formed by two
tunnel coupled quantum dots, which are laterally confined in a two-dimensional
electron system of an AlGaAs/GaAs heterostructure. Coherent
molecular states in the coupled dots are probed by photon-assisted tunneling
(PAT). Above 10 GHz, we observe clear PAT as a result of the resonance between
the microwave photons and the molecular states. Below 8 GHz, a pronounced
superposition of phonon- and photon-assisted tunneling is observed. Coherent
superposition of molecular states persists under excitation of acoustic
phonons.Comment: 5 pages, 4 figure
Bilateral renal angiomyolipomas with invasion of the renal vein: A case report
An angiomyolipoma (AML) is usually a benign, rare, and, more commonly, a unilateral renal tumour. Bilateral tumours are very rare, particularly in the absence of tuberous sclerosis complex. Only in a few isolated cases have features of malignancy been associated with an AML. We present a unique case of bilateral AMLs mimicking invasive tumours in the absence of any other features of tuberous sclerosis complex
Anaplastic, T-cell, Non-Hodgkin's Lymphoma Presenting with Haematuria
Non-Hodgkin's lymphoma (NHL) represents about 3% of new cancer cases[1]. Bladder involvement has been found in approximately 3-13% of NHL patients when studied at postmortem[2]. Although accounting for only 0.2% of all primary bladder tumours, the majority of bladder lymphomas are B-cell lymphomas. T-cell lymphoma of the bladder is incredibly rare. We describe a case of anaplastic, T-cell lymphoma presenting with haematuria and loin pain, with unilateral upper tract obstruction
Schizomida/ZwerggeiĂelskorpione (Arachnida): eingeschleppt nach Europa - ein Aufruf
JĂŒngst (2004 bis 2006) wurden noch zu bestimmende Schizomiden in zwei GewĂ€chshĂ€usern in Deutschland gefunden. Da derartige FĂ€lle sehr selten zu sein scheinen, möchten wir solche Meldungen zusammentragen und bitten hiermit um Literaturhinweise und Vermittlung/Zusendung von eventuell weiteren vorhandenen Exemplaren
Recommended from our members
Sequence Stratigraphy in Proterozoic Successions
Sedimentological logging and facies mapping have been used to identify depositional sequences bounded by subtle but regionally persistent unconformities in rocks of Proterozoic age in the western United States, South Australia, and northwestern Canada. We conclude from these studies that the sequence stratigraphic approach is of considerable importance for intrabasinal time correlation in the Proterozoic and for facies interpretation and basin analysis in Proterozoic rocks
Recommended from our members
Depositional Sequence Analysis Applied to Late Proterozoic Wilpena Group, Adelaide Geosyncline, South Australia
The initial application of depositional sequence analysis to selected stratigraphic sections through outcropping Late Proterozoic strata of the Adelaide Geosyncline in South Australia has identified major depositional sequences within the severalâkilometreâthick Wilpena Group. Sharp facies shifts in vertical stratigraphic sections are proposed as actual sequence boundaries which, provided they are the result of eustatic sea level variations, may be key elements for future attempts at interâregional chronostratigraphic correlation.
Two major sequence boundaries are identified, one at the base of the Nuccaleena Formation (boundary A) and a second at the top of the Brachina Subgroup (boundary B). These are attributed to significant basinward shifts in coastal onlap resulting in subaerial exposure and at least localized erosion, followed in each case by establishment of relatively deepwater environments. A somewhat different boundary (boundary C) is associated with an interval of diagenetic dolostone interbeds and is interpreted either as a downlap surface within a sequence, or as a combined deepwater sequence boundary and downlap surface. It may have developed during an episode of reduced sediment input in response to a period of maximum transgression. Alternatively it may represent a hiatus at the termination of a depositional sequence, prior to subsequent downlap or onlap of the succeeding sequence.
Boundary C lies a few metres below the stratigraphic level from which kilometreâdeep canyons have incised underlying sequences. These canyons, which are infilled by a complex succession of carbonate breccias, conglomerates, sandstone and mudstone, may have been eroded in a submarine setting by turbidity currents. Such a model requires a significant increase in rate of eustatic sea level fall or a decrease in the rate of tectonic subsidence, in order to move the locus of coastal onlap to the vicinity of the shelf edge. If the cause was eustatic, evidence for it should be found at an equivalent sequence boundary in Late Proterozoic basins remote from the Adelaide Geosyncline. Alternatively, the canyons may have been eroded in a subaerial setting and infilled by coastal sediments during an ensuing period of relative sea level rise. In this model a considerably greater drop in relative sea level is required, most likely related to localized tectonic uplift
Recommended from our members
Sequence Stratigraphy and Evolution of a Basin-Slope Succession: The Late Proterozoic Wonoka Formation, Flinders Ranges, South Australia
A shelf to basinâslope transition is vertically and laterally exposed within the Late Proterozoic Wonoka Formation in the northern Flinders Ranges of South Australia. The shelf to basinâslope transition can be divided into four units (C to F) which are defined on the basis of facies, sedimentary structures, contacts, stratal geometry, and the type and abundance of downâslope mass movement. The lowest unit (C) is mudstone dominated and parallel laminated with rare synsedimentary slides. Unit D, a thin, resedimented siliciclasticâcarbonate unit deposited on a sequence boundary at the end of unit C progradation, displays a lateral facies change from well bedded âouter shelf deposits in the east to basinâslope debris flows in the west. Unit E forms a shallowing and coarsening upward succession from âouter shelf siltstone to âinner shelf storm wave influenced sandstone deposits. The unit thickens westwards, in the interpreted downâslope direction, where it becomes finer grained and thinner bedded and displays an increasing abundance of synsedimentary slides. Unit F, deposited on an inferred shelf to basinâslope transition, coarsens and shallows upward, thickens to the west and contains the highest percentage of sandstone and synsedimentary slides. Unit G, deposited at shelf depths, also shallows and coarsens upward from a thin, basal carbonateâsiliciclastic member, with sandstone increasing upsection to a gradational contact with the Pound Subgroup.
Three sequences can be defined within this transition on the basis of facies, stratal terminations, and facies discontinuities at inferred sequence boundaries. Each sequence is marked by a transgressive base, overlain by a shallowingâupward succession. On the inferred shelf and near the shelfbreak, toward the top of the succession, facies discontinuities at sequence boundaries are more obvious, with distinct contrasts in lithology and inferred palaeoenvironments; farther downâslope and stratigraphically lower in the succession, the boundaries are cryptic, and only lateral tracing of the contacts from the shelf to the slope or the observation of stratal terminations permits them to be recognized
A unique case of a malignant sertoli cell tumour with cutaneous metastasis
Pure Sertoli cell tumours (SCTs) represent less than 1% of testicular neoplasms and malignant forms are rare. We present a unique case of a 69-year-old man who initially underwent inguinal orchidectomy for a malignant SCT. He then subsequently developed a paraumbilical cutaneous lesion which was histologically identical to the primary tumour. SCTs rarely metastasise. This is the first case of SCT with cutaneous metastasis described in the literature
- âŠ