Efficient erbium-doped fibre amplifier pumped at 820 nm

The highest gain coefficients of 0.86 dB/mW at 1.552 mu m and 0.72 dB/mW at 1.534 mu m are realised at a pumping wavelength of 822 nm by using an erbium-doped fibre with a relative refractive index difference as high as 1.67%, a low intrinsic loss, and an erbium ion concentration of 210 p.p.m. The gains at 1.552 mu m reach 25 and 30 dB for launched pump powers of 30 and 40 mW, respectively.<>     

Ultralong dispersion-shifted erbium-doped fiber amplifier and itsapplication to soliton transmission

Distributed, dispersion-shifted erbium-doped fiber amplifiers with doping concentrations as low as 0.1-0.5 p.p.m. (0.1-0.5×10^-4 wt.%) were fabricated and their grain characteristics studied for the purpose of soliton amplification. A 9.4-km dual-shape-core-type amplifier with a 0.5-p.p.m. concentration had a gain of more than 20 dB at 1.535 μm and 10 dB at 1.552 μm with a forward pumping configuration, and it could successfully amplify and transmit a 20-ps soliton pulse train at a 2.5-GHz repetition rate. The soliton transmission characteristics of an 18.2 km long fiber amplifier were studied using backward and forward pumping. It was found that A=1.5 soliton pulses with a pulse width of 20 ps could be amplified over 18.2 km at a repetition rate of 5 GHz, where soliton narrowing to 16 ps was observed     

Pancreatic mucin-producing adenocarcinoma associated with a pancreatic stone: report of a case

We present an autopsy case of an 83-year-old Japanese man with a mucin-producing adenocarcinoma accompanied by pancreatolithiasis in the head of the pancreas. He suffered from obstructive jaundice and died of disseminated intravascular coagulation. He did not normally drink alcohol and had no history of chronic pancreatitis. The autopsy findings revealed a mucinous cystic tumor, composed of multiple dilatated branches, in the head of the pancreas. Histological examinations showed papillary adenocarcinoma, which scirrhously infiltrated the distal common bile duct with perineural invasion and lymph node involvement. He was thus diagnosed to have mucin-producing branch-type cancer in the head of the pancreas. The main pancreatic duct was dilated, and the residual pancreatic tissue showed moderate fibrosis and parenchymal atrophy. A stone was observed in a dilated branch of the primary lesion. To the best of our knowledge, there have only been five previously reported cases of mucin-producing tumor associated with pancreatolithiasis. Intraductal calcification is a major characteristic of chronic pancreatitis, but it is clinically important not to misdiagnose cancers associated with pancreatolithiasis such as chronic pancreatitis.     

Novel mutations of the glutaryl-CoA dehydrogenase gene in two Japanese patients with glutaric aciduria type I

We identified three different point mutations in the glutaryl-CoA dehydrogenase (GCDH) gene in two unrelated Japanese patients with glutaric aciduria type I (GA-I). One patient was a homozygote for Arg355His and the other a compound heterozygote for Ser305Leu and Met339Val. Arg355His and Met339Val are mutations hitherto undescribed, and all three mutations are predicted to alter the secondary structure of GCDH. Molecular analysis is useful for definite diagnosis and/or prenatal diagnosis of GA-I.     

Cell-to-cell interaction is required to induce proteinuria in in situ immune complex glomerulonephritis

This experiment was performed to study the roles of intercellular adhesion molecule-1 (ICAM-1), lymphocyte function-associated antigen-1 (LFA-1), and another adhesion molecule, selectin, in the development of cationized antigen-induced in situ immune complex glomerulonephritis (CAICGN). CAICGN was induced in preimmunized rats by perfusing cationized human immunoglobulin G (CaIgG) through the left kidney. Albuminuria developed within 2 days of CaIgG perfusion and peaked around day 7. Marked polymorphonuclear leukocyte (PMN) infiltration was observed in the glomeruli 1 hour after CaIgG perfusion, but the infiltrate resolved by day 7. Immunofluorescent studies disclosed linear deposition of rat IgG and C3 along glomerular capillary walls 1 hour after CaIgG perfusion. Treatment with monoclonal antibodies (mAbs) to both ICAM-1 and LFA-1, as well as with a sulfatide, a ligand of L- and P-selectin, started within 2 days after CaIgG perfusion completely suppressed the development of proteinuria without affecting the glomerular deposition of immunoreactants. Although sulfatide attenuated the PMN response 1 hour after CaIgG perfusion, ICAM-1 and LFA-1 mAb treatment did not alter PMN infiltration. Treatment with ICAM-1 and LFA-1 mAbs started on day 5, or treatment with sulfatide started on day 4, after CaIgG perfusion did not affect albuminuria. These findings suggest that adhesion molecules play an important role in the development of proteinuria in CAICGN. The contribution of these molecules was evident for only a short interval after the induction of nephritis, when a significant infiltration of PMNs was observed.     

Three-dimensional analysis of the interface between an Sn-8wt.%Zn-3wt.%Bi solder and a substrate by using an angle-lapping method

The validity of application of the angle-lapping method to investigate the microstructure between an Sn-8wt.%Zn-3wt.%Bi Pb-free solder and an Auimmersed Ni-7.0%P plate or a Cu substrate was studied using transmission electron microscopy. The method enabled a three-dimensional analysis of the interface layers. The morphology of the Au layer was clarified as an intermetallic compound with Zn with numerous voids that looked like cracks spreading in all directions. Sn and Bi could diffuse into the interface layer only when the Ni-P plate was used, but Ni did not diffuse actively and formed a narrow interface layer. When a Cu substrate was used, Cu diffused, rather than Sn or Bi, and formed a relatively wide interface layer. These results were obtained with the angle-lapping method.     

Comparative nutritional value for amino acids,oligopeptides and soybean protein

In recent years our view on the absorption of protein digestion products has undergone a radical change. We now believe that intralumen hydrolysis of intake proteins to free amino acids is only partial. It has thus been hypothesized that partial protein hydrolysates or oligopeptide mixtures are nutritionally superior to corresponding amino acid mixtures. With this consideration for a background, we developed a sophisticated technique of protease-catalyzed modification of soy protein to produce enzymatically modified proteins (EMP) having different levels of covalently attached methionine. We also carried out feeding tests with protein-malnourished rats, with the result that for their recovery from a state of malnutrition, an EMP containing peptide-bound methionine at 3% was significantly more effective than the corresponding amino acid mixture and even the soy protein itself. Discussions stress the importance of applying such a technique to production of an oligopeptide rather than a free amino acid nitrogen source as a foodstuff for therapeutic use.     

Ionic conductivity of substituted Li2SO4 phases

Lithium ion conductivity of Li₂SO₄-Y₂(SO₄)₃, Li₂SO₄-La₂(SO₄)₃ and Li₂SO₄-Li₃PO₄ systems has been measured as a function of composition and temperature using AC complex impedance methods. Substitution of the trivalent cations results in a small enhancement of the ionic conductivity within the limit of solid solution formation. Considerable increase of the conductivity results by substitution of PO₄^3? for SO₄^2?. The maximum conductivity observed is $\text{1.1×10}{}^{\mathrm{?3}}\text{(Ω}\text{cm}\text{)}{}^{\mathrm{?1}}$ at 300°C for the composition Li_2.2S_0.8P_0.2O₄ with E_a = 0.8 eV. These results are discussed in terms of the structural properties.