Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    High-precision refractive index measurements revealing order parameter fluctuations in KMnF3 and NiO (1985)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 57 (1985), S. 2606-2612 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The temperature dependence of the refractive index n of cubic crystals undergoing phase transitions (PT) is measured with an accuracy of the order δn=10−6 at temperatures between 3.5 and 1000 K with a computer-controlled Jamin–Lebedeff interferometer. Microscopic monitoring for in situ sample orientation and single domain work is provided. Results are presented for KMnF3 (antiferrodistortive PT) and NiO (antiferromagnetic PT) and discussed within the framework of a generalized phenomenological indicatrix perturbation theory. It predicts the proportionality between the order parameter autocorrelation function 〈δη2〉 and the refractive index anomaly preceding the PT. Comparison with recent theoretical predictions is performed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.335451
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    High-temperature properties of GaInAs/AlGaAs lasers with improved carrier confinement by short-period superlattice quantum well barriers (1998)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 73 (1998), S. 2863-2865 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The influence of the carrier confinement on the output characteristics of GaInAs/AlGaAs lasers was investigated. To improve the carrier confinement, AlGaAs/GaAs short-period superlattices were used as quantum well barriers. In comparison to lasers with GaAs barriers the structures with the modified barriers show improved temperature properties at low threshold current densities without deterioration of the internal quantum efficiency (〉95%). High characteristic temperatures (T0) well above 300 K were measured between 20 and 75 °C and laser operation up to 238 °C could be achieved. The large improvement in T0 is mainly attributed to the reduced thermionic emission of carriers out of the quantum well due to the increased barrier height and the carrier reflection above the barrier by the short-period superlattice. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.122611
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Laser emission from photonic dots (1997)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 71 (1997), S. 488-490 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Laser emission was observed in photonic semiconductor dots with a discretized optical mode spectrum. The photonic dots with lateral sizes between 1 and 5 μm provide a three-dimensional optical confinement by using in the vertical direction AlAs/GaAs Bragg mirrors and in the lateral directions the refractive index discontinuity at the etched surfaces. In the optically pumped structures, the laser emission takes place on the fundamental mode of the microcavities. External threshold excitation densities of 200 W/cm2, which correspond to a very low internal optical excitation power of 0.15 μW per microcavity post, were measured for microcavity structures with a lateral size of 2.7 μm. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.119587
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Soft x-ray emission from plasmas produced by ultraintense KrF-laser pulses in colloidal Al (1996)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 68 (1996), S. 1338-1340 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The interaction of subpicosecond KrF-laser pulses with polished and colloidal metal surfaces at an intensity of 8×1015 W/cm2 was investigated experimentally. The measurements with spectral and temporal resolution for the colloidal targets showed a higher energy conversion efficiency into soft x rays and an increase in x-ray pulse lengths. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.115927
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Low-threshold high-quantum-efficiency laterally gain-coupled InGaAs/AlGaAs distributed feedback lasers (1999)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 74 (1999), S. 483-485 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We have developed gain-coupled lasers based on metal gratings patterned laterally to the laser ridge. For narrow ridge waveguides, the evanescent field of the laser mode couples to the grating. The fabrication requires no overgrowth steps and can be applied to all material systems. Ridge-waveguide gain-coupled lasers with threshold current densities of 600 A/cm2 were obtained from InGaAs/AlGaAs GRINSCH structures. The continuous wave threshold currents are around 9 mA for a cavity with 600 μm length and 2.5 μm width. Monomode emission up to output power levels of 64 mW and sidemode suppression ratios of over 45 dB have been obtained. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.123164
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    High-performance GaInAs/GaAs quantum-dot lasers based on a single active layer (1999)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 74 (1999), S. 2915-2917 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: GaInAs/GaAs quantum-dot lasers were fabricated by self-organized growth in a molecular beam epitaxy system. By using a single active layer, lasers with low-threshold current densities (Jth=144 A/cm2 for a 2 mm long device) and high internal quantum efficiencies (〉90%) were obtained. Ground-state lasing of the quantum dots was observed up to a device temperature of 214 °C. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.123964
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Low-dose cyclosporin A therapy in cadaver renal transplantation in children (1989)
    Springer
    Transplant international 2 (1989), S. 203-208 
    Details
    ISSN: 1432-2277
    Keywords: Pediatric renal transplantation ; Cyclosporin, low-dose, in children ; Growth, cyclosporin, in kidney transplantation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Fifty-one pediatric patients undergoing a first cadaveric kidney transplantation were followed for at least 2 years after grafting. They were divided into two groups: those treated with methylprednisolone plus azathioprine (AZA) and those treated with methylprednisolone plus low-dose cyclosporin A (CyA; median dose 109 mg/m2 per day ≙ 3.4 mg/kg per day after 1 year). The steroid dosage given was significantly lower in the second group. The 4-year graft survival rate was 68% for the AZA group and 78% for the CyA group. Renal function did not differ significantly in the two groups; after 1, 2, and 3 years, the median 24-h creatinine clearance was 79, 69, and 51 ml/min/1.73 m2, respectively, for the AZA group and 78, 63, and 68 ml/min/1.73 m2, respectively, for the CyA group. Linear growth was similar in the two groups. We conclude that in pediatric patients the results of low-dose CyA immunosuppression do not differ significantly from those obtained with AZA in terms of graft survival, renal function, or growth.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02414535
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Impact of recurrent nephrotic syndrome after renal transplantation in young patients (1998)
    Springer
    Pediatric nephrology 12 (1998), S. 529-533 
    Details
    ISSN: 1432-198X
    Keywords: Key words: Nephrotic syndrome ; Focal segmental glomerulosclerosis ; Renal transplantation ; Recurrent disease ; Plasma exchange
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract. Recurrent disease is a frequent complication of patients transplanted for steroid-resistant nephrotic syndrome associated with focal segmental glomerulosclerosis. Its long-term prognosis has rarely been studied. We examined 39 patients aged 4–25 (mean 13.5) years at the time of first transplantation (TX). Twelve of these (30%) developed nephrotic syndrome after the first TX and 2 of 8 after the second TX. The mean observation period from first TX to last observation with a functioning graft or graft loss was 5.4 (0.1–19.3) years. We confirmed that recurrent disease is associated with older age at onset of the primary disease, shorter time from onset to end-stage renal disease, and diffuse mesangial proliferation in the initial kidney biopsy. Remissions occurred in all 3 children undergoing early repeated plasma exchange and in 1 adolescent following introduction of cyclosporin A 7 years after TX. At last observation 42% of relapsing and 48% of non-relapsing patients with a similar follow-up period had a functioning first graft. Median first graft survival was almost identical in the relapsing and the non-relapsing patients (4.3 vs. 4.2 years). Histological lesions of focal glomerulosclerosis were detected in the posttranplant biopsies of only 3 patients. In conclusion, young patients with nephrotic syndrome associated with focal segmental sclerosis have a similar graft survival with and without recurrence of the nephrotic syndrome.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004670050499
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Clinical outcome of Schönlein-Henoch purpura nephritis in children (1999)
    Springer
    Pediatric nephrology 13 (1999), S. 816-823 
    Details
    ISSN: 1432-198X
    Keywords: Key words Schönlein-Henoch purpura ; Glomerulonephritis ; Hypertension ; Proteinuria ; Renal failure ; Plasma exchange
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  We studied the long-term outcome of 64 children with biopsy-proven Schönlein-Henoch purpura (SHP) nephritis over 1–23 years of follow-up. Overall renal survival 10 years after onset was 73%. Multivariate logistic regression analysis identified initial renal insufficiency (P=0.004), nephrotic syndrome (P=0.037), and the severity of histological alterations, as defined by the proportion of glomerular crescents (P=0.051), as significant independent predictors of progressive renal failure. Four patients followed for more than 19 years showed glomerular damage after transient recovery. Eight children with crescentic nephritis associated with a rapidly progressive course and/or persistent nephrotic syndrome were treated by at least seven sessions of plasma exchange (PE) within 16 weeks of onset of purpura. During treatment serum creatinine levels dropped in each patient from a mean of 2.3 to 1.1 mg/dl, followed by a rebound increase. Repeated courses of PE in 5 patients produced comparable responses. Four patients undergoing PE reached end-stage renal disease at 1.2.–3.7 years after onset, whilst 3 finally were in preterminal renal failure (creatinine 3.2–6.1 mg/dl after 7–13.5 years), and 1 patient reached a normal glomerular filtration rate. Our experience suggests that initial renal insufficiency is the best single predictor of the further clinical course in children with SHP nephritis. Early PE appears to delay the progression in some patients with severe, rapidly progressive forms of the disease.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004670050707
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Short dialyzed children respond less to growth hormone than patients prior to dialysis (1996)
    Springer
    Pediatric nephrology 10 (1996), S. 294-298 
    Details
    ISSN: 1432-198X
    Keywords: Growth ; Dialysis ; Chronic renal failure ; Growth hormone ; Anemia ; Metabolic acidosis ; Glomerular filtration rate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Recombinant human growth hormone (rhGH) is a new treatment modality for short children with chronic renal failure (CRF) prior to and during dialysis. It is difficult to analyze whether dialysis patients respond less to rhGH than children with CRF on conservative treatment because they are older and often in a pubertal age range. One hundred and eight patients were treated with 28–30 IU rhGH/kg per week for at least 1 year. We analyzed the growth response to rhGH in 56 prepubertal patients aged less than 10 years at the start of rhGH treatment; 38 children with a mean age of 6.5±2.4 years were on conservative treatment (CT) and 18 patients with a mean age of 6.5±2 years on dialysis treatment (D). Mean height velocity was 4.9±2.3 cm/year in children on CT and 4.6±1.8 cm/year in children on D. During the 1 st treatment year, height velocity was 9.5±3.8 cm/year in CT patients and 7.3±1.3 cm/year in D patients (P〈0.05). The change in height was +1.1±0.8 standard deviation (SD) in CT patients and +0.5±0.4 SD in D patients (P〈0.005). During the 2nd treatment year, the change in height was again greater in CT patients (0.5±0.4 SD vs. 0.2±0.4 SD;P〈0.05). The difference in height velocity and change in height standard deviation score was also significant when a subgroup of patients was matched for sex, age, height. Height velocity and the change in height velocity during rhGH treatment were not correlated with residual renal function, the degree of anemia, or metabolic acidosis. We conclude that short children on D respond less to rhGH than short children on CT, indicating a greater insensitivity to rhGH during D treatment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00866763
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...