Gain-flattened tellurite-based EDFA with a flat amplificationbandwidth of 76 nm

We describe a tellurite-based Er³⁺-doped fiber amplifier (EDFA) with a flat amplification bandwidth of 76 nm and a noise figure of less than 7 dB. Furthermore, a parallel-type amplifier composed of this EDFA and a 1.45-μm-band Tm³⁺-doped fluoride fiber amplifier achieved a flat amplification bandwidth of 113 nm     

Topical Phenomena Observed in a Short-Gap Atmospheric Discharge Using Rotor and Post Electrodes

Correlation of light emission, discharge structure, waveform of the discharge current, electrode configuration, and electromagnetic radiation is examined with the intent of obtaining an effective means for preventing electromagnetic interference (EMI) due to a short-gap discharge. The electromagnetic radiation (EMR) level resulting from a current step which, in turn, was formed by a discrete movement of a cathode spot was clearly recognized. A combination of needle rotor and needle post gave the smallest electromagnetic radiation level in the experiments.     

L-band Er3+-doped fluorophosphate glass-fibre amplifier

The first L-band EDFA to employ fluorophosphate glass as the host glass material has been realised. The lowest fibre loss yet reported for fluorophosphate glass fibre of 0.7 dB/m is achieved. The amplifier achieved a flat gain with an average value of 21.7 dB in the L-band.     

柿叶多酚的提取及体外生物活性的研究

利用水以及不同体积百分比(20%、40%、60%、80%和100%)的甲醇、乙醇、丙酮时柿(Diospyros kaki cv.Mopan)叶中的多酚物质进行提取,提取率最高的不同溶剂提取物采用HP-20大孔树脂进行纯化,分别得到了水提取物(WE)、甲醇提取物(ME)、乙醇提取物(EE)和丙酮提取物(AE),并时不同提取物的体外抗氧化活性、胶原酶和酪氨酸酶抑制活性进行了分析和比较.结果表明.柿叶中的多酚含量相于27.4±0.21mg GA/g(干重).采用体积分数为60%的丙酮溶液提取柿叶多酚时.柿叶多酚的提取率最高,为74.3%±2.3%.60%丙酮提取物对1,1-二苯基-2-苦基苯肼(DPPH)自由基的清除能力最高,达O.27±0.02μmol Trolox/mg,对胶原酶和酪氨酸酶也具有较高的抑制活性,IC50值分别为92.8 4-2.9μg/mL和185.4±5.3μg/mL.     

Antimicrobial effect of spices and herbs on Vibrio parahaemolyticus

The antimicrobial effects of spices and herbs from 18 plant species were examined on a foodborne pathogen, Vibrio parahaemolyticus, with the use of combinations of temperatures and nutrient levels. Basil, clove, garlic, horseradish, marjoram, oregano, rosemary, and thyme exhibited antibacterial activities at incubation of 30 degrees C, while with the exception of horseradish, the same spices and additional 7 species exhibited the activities at 5 degrees C. The lowest MIC (minimum inhibitory concentration) was 0.125% observed in clove and marjoram at 30 degrees C in a nutrient rich medium. Lowering of incubation temperature produced little effect on the MICs except for turmeric. The decreasing of the MIC in turmeric appeared to be basically attributed to the sensitivity of the bacterium to coldness. In nutrient poor medium, the lowest was 0.001 and 0.00025% in marjoram at 30 degrees C and at 5 degrees C, respectively. The sensitivity to several spices and herbs was similar among different clinical serotypes including the emerging strain O3:K6. These results suggest that the spices and herbs can be practical for protecting seafood from the risk of contamination by V. parahaemolyticus and used in hurdle technology with low temperature.     

Interdiffusion in copper-rich cu-ag solid solutions

Interdiffusion was studied in the temperature between 974 and 1273 K, using conventional sandwich-type diffusion couples consisting of pure copper and Cu-2.1 at. pct Ag alloy. The interdiffusion coefficient, , increased slightly with increasing the atomic fraction of silver, N_Ag. Values of were well represented by the parameters of ₀ = 0.21 x 10^-4 (m²/s) and ≈ = 184.5 - 143.0 N_Ag (kJ/g-atom) up toNAg = 0.02. The Kirkendall effect during diffu-sion treatments at 1174 K for up to 1.4724 x 10⁶ s was also studied. The marker moved always toward the silver-rich side. The ratio, D*_Ag / D*_Cu,was 5.6 for N_Ag = 0.011, while it was 4.2 for N_Ag = 0.     

Plasma developable photoresist containing electronic excitation energy quenching system

A dry developable negative working resist composition comprised of poly(methyl isopropenyl ketone) (PMIPK) and 4-methyl-2,6-di(4′-azido-benzylidene) cyclohexanone-1 was examined. The main photochemical product formed in the resist pattern was found to be a secondary amine which crosslinks PMIPK. Post-annealing forms a hydrogen-bonded product which shows a powerful electronic excitation energy quenching effect. The quencher is more powerful than the aromatic compound arising from the azide by post-annealing only. The residual resist thickness of the negative pattern is about 80 percent of the initial thickness of the coating in spite of all the azide compound remaining in the resist coating. The obtained dry developed resist pattern has a high dry etch resistance. Etchings of Si and SiO₂ were performed by plasma and reactive ion etching, respectively.     

Cerebral Hyperperfusion after Revascularization Inhibits Development of Cerebral Ischemic Lesions Due to Artery-to-Artery Emboli during Carotid Exposure in Endarterectomy for Patients with Preoperative Cerebral Hemodynamic Insufficiency: Revisiting the “Impaired Clearance of Emboli” Concept

The purpose of the present study was to determine whether cerebral hyperperfusion after revascularization inhibits development of cerebral ischemic lesions due to artery-to-artery emboli during exposure of the carotid arteries in carotid endarterectomy (CEA). In patients undergoing CEA for internal carotid artery stenosis (≥70%), cerebral blood flow (CBF) was measured using single-photon emission computed tomography (SPECT) before and immediately after CEA. Microembolic signals (MES) were identified using transcranial Doppler during carotid exposure. Diffusion-weighted magnetic resonance imaging (DWI) was performed within 24 h after surgery. Of 32 patients with a combination of reduced cerebrovascular reactivity to acetazolamide on preoperative brain perfusion SPECT and MES during carotid exposure, 14 (44%) showed cerebral hyperperfusion (defined as postoperative CBF increase ≥100% compared with preoperative values), and 16 (50%) developed DWI-characterized postoperative cerebral ischemic lesions. Postoperative cerebral hyperperfusion was significantly associated with the absence of DWI-characterized postoperative cerebral ischemic lesions (95% confidence interval, 0.001–0.179; p = 0.0009). These data suggest that cerebral hyperperfusion after revascularization inhibits development of cerebral ischemic lesions due to artery-to-artery emboli during carotid exposure in CEA, supporting the “impaired clearance of emboli” concept. Blood pressure elevation following carotid declamping would be effective when embolism not accompanied by cerebral hyperperfusion occurs during CEA.     

Properties of reverse osmosis membranes prepared from poly(4-vinyl pyridine)-acrylonitrile copolymer and the partially quaternized copolymer

Reverse osmosis membranes were prepared from 4-vinyl pyridine(4VP)-acrylonitrile (AN) copolymers and those partially quaternized. Their salt rejection (S) and hydraulic water permeability (K₁) were investigated with regard, to co-polymer composition, the membrane profile by SEM observation, cross-linking quaternization with diiodobutane (DIB) and the method of membrane preparation. S decreased with increasing AN content, but K₁ was closely dependent on water content which had a minimum at about 65% 4VP. The increase in K₁ and water content in a high AN range was caused by the change in the membrane structure from dense to porous one.Quaternization with DIB to a small extent notably improved K₁, up to ten times without significant change in S, and most effectively improved both of the membrane structure and the performance of AN rich copolymer membranes which were the highest in tensile strength among the copolymers. It was found by IR and elemental analysis that DIB charged was nearly completely reacted. The DIB modified membranes were anion exchangeable and more than two-thirds of iodide were exchanged for chloride. The modification reduced the membrane strength, to the least extent in the AN rich copolymers, with increasing DIB due to an increase in water content. The quaternized membranes prepared by surface-treating with DIB gave an essentially similar performance and had a composite structure which held unreacted layer.Monofunctional quaternizing agents merely brought about a poor membrane performance.Water transport through the membranes followed solution-diffusion mechanism for the membranes of volume fraction of water smaller than 0.41. The membranes modified with DIB to a small degree were regarded as tight ionic membranes and able to be treated as a nonionic ones, although they behaved ionically showing a decrease in S with the increasing feed concentration.     

Postnatal changes in activation of polyunsaturated fatty acid,acylation of lysophosphoglyceride,and phosphorylation of diacylglycerol in cortical gray matter of rat cerebrum

Activation of polyunsaturated fatty acid, acylation of lysophosphoglyceride, and phosphorylation of diacylglycerol in postnatal developing rat cerebrum were studiedin vitro, using cortical gray matter homogenates. The rate of n-3 and n-6 fatty acid activation was maximal at ten days after birth and minimal at adulthood. Acylation of lysophosphoglyceride was most active at the neonatal stage and gradually decreased with age. In addition, the amount of phosphatidic acid formed from 1, 2-dioleoyl-glycerol was also maximum at the neonatal stage, and then gradually decreased. These results suggest that the specific activity of glycerolipid synthesis in cortical gray matter declines during postnatal development.