In this work we report on the optical properties of electrical injected microcavity light emitting diodes emitting at 1.3 /spl mu/m at room temperature. The active medium consists of a single layer ...of reduced strain quantum dots, directly grown in a GaAs matrix by metalorganic chemical vapour deposition (MOCVD). Based on this method, two different fabrication approaches have been developed: one based on a fully epitaxial structure and one based on a hybrid structure, matching semiconductor epitaxial and dielectric mirrors. The device based on the hybrid technology, less invasive for the quantum dot optical properties, exhibits, at room temperature, high external quantum efficiency. The effect of the selective oxidation on the top mirror is also investigated and improved device performance is found. These results represent a promising way for the realisation of high performance QD VCSEL structures.
We report on the growth, fabrication and characterization of low threshold laser diodes emitting around 1.3 mum. The quantum dot active region was optimised to get the highest photoluminescence ...emission and the lowest full width at half maximum (FWHM). Broad area laser diodes were processed from different samples containing three layers of InAs quantum dots (QDs), and cleaved at different cavity lengths (L C ). Electro-luminescence measurements were performed at room temperature under pulsed excitation. The laser diodes operate at room temperature and emit at 1.32 mum, in the low-absorption spectral window for telecom applications. The characteristic temperature T 0 is in the range 60-77 K and the differential quantum efficiency is 53 %. For an infinite cavity length a threshold current density of 8 A/cm 2 per QD layer was obtained. Lasing from short-cavity diodes (L C = 750 mum) was also obtained after e-beam evaporation of high-reflection coatings on one edge of the in-plane laser structure
Reference is made to two personal cases in underscoring the fact that meralgia paraesthetica, though regarded as a form that displays a preference for adult males, must be considered as extended to ...subjects of all ages when a benign or malignant neoformation irritating the L2 root or its trunk is involved. Before classifying a case as idiopathic, therefore, one must rule out the possibility of intra-abdominal disease-usually malformative in young subjects, and benign or malignant in persons of all ages. Lastly, stress is laid on the fact that atypical lumbar and sciatic pain in the adult may be secondary to aneurysm of the abdominal aorta, the common iliacs and the hypogastric. Hence the need to look for such conditions symptomatologically.
LE cells, ds-DNA antibodies (radioimmunoassay), antinuclear antibodies (ANA) by indirect immunofluorescence (IFI) and anti-ENA antibodies have been sought in 150 clinical cases observed over a 5-year ...period in the Rheumatology Division of Bari University. For the latter, three parallel techniques were adopted on each serum, each completed by RNA-sensitivity assay for the demonstration of anti-RNP, i.e. IFI, passive haemoagglutination (PHA) and controimmunoelectrophoresis (CIE). The series included systemic lupus erythematodes (SLE), 30 cases; rheumatoid arthritis (RA), 30 cases; progressive systemic sclerosis (PSS), 12 cases; unclassified connective tissue disease (UCTD), 8 cases; mixed connective tissue disease (MCTD), 7 cases; Sjögren's syndrome (SS), 4 cases; dermatomyositis (DM), 3 cases; overlap syndromes (PSS-SLE, SS-SLE), 2 cases; rheumatological and internal miscellanea, 54 cases, LE cells and ds-DNA antibodies were found exclusively in SLE; the anti-ENA were found in various groups of diseases, while the anti-RNP were only demonstrated in the 7 MCTD and in some SLE. Of the three techniques for demonstrating anti-ENA, the PHA proved most sensitive and CIE most specific, whereas IFI was considered most suitable for clinical screening. The clinical aspects of the 7 MCTD faithfully followed the disease picture described by Sharp, but some overlap-syndromes and the unclassified connective tissue diseases did not present anti-RNP. It is also pointed out that nephropathy is not rare in MCTD and that the clinical course of the disease is not always benign. To conclude, it is considered that MCTD merits nosographic autonomy, but further investigations are recommended for more exact nosographical typing of connective tissue diseases.
Serum proline iminopeptidase and (where possible) urinary hydroxyproline were determined in 214 subjects: normal subjects, subjects with chronic kidney disease, subjects with chronic liver disease, ...subjects with osteitis deformans, subjects with rheumatoid arthritis, and subjects with osteoporosis. The values of the two parameters fully corresponded. It is suggested, therefore, that proline iminopeptidase can be determined instead of hydroxyproline in cases where a primarily destructive bone disease in present.
In this study the authors developed new technics of study of duodenal absorption of calcium in rats: atomic absorption spectrophotometry, and dialysis to equilibrium. We considered that the main ...factors necessary for evaluation of duodenal absorption of calcium are the serum calcium, the calcium and alkaline phosphatase present in the duodenal cells and the calcium-binding proteins. The authors demonstrate that these factors are highest in rats treated with 25 OHD3 and norandrostenolone decanoate, than in control rats. In rats treated with diphosphonate, on the contrary, they obtained a reduction in the values of calcium and alkaline phosphatase contained in the duodenal cells.
