CD34-deficient mice have reduced eosinophil accumulation after allergen exposure and show a novel crossreactive 90-kD protein

CD34 is expressed on the surface of hematopoietic stem/progenitor cells, stromal cells, and on the surface of high-endothelial venules (HEV). CD34 binds L-selectin, an adhesion molecule important for leukocyte rolling on venules and lymphocyte homing to peripheral lymph nodes (PLN). We generated CD34-deficient mutant animals through the use of homologous recombination. Wild-type and mutant animals showed no differences in lymphocyte binding to PLN HEV, in leukocyte rolling on venules or homing to PLN, in neutrophil extravasation into peritoneum in response to inflammatory stimulus, nor in delayed type hypersensitivity. Anti-L-selectin monoclonal antibody (MEL-14) also inhibited these immune responses similarly in both CD34-deficient and wild-type mice. However, eosinophil accumulation in the lung after inhalation of a model allergen, ovalbumin, is several-fold lower in mutant mice. We found no abnormalities in hematopoiesis in adult mice and interactions between mutant progenitor cells and a stromal cell line in vitro were normal. No differences existed in the recovery of progenitor cells after 5-fluorouracil treatment, nor in the mobilization of progenitor cells after granulocyte colony-stimulating factor treatment compared with wild-type animals. Surprisingly, although CD34 was not expressed in these mice, a portion of its 90-kD band crossreactive with MECA79 remained after Western blot. Thus, we have identified an additional molecule(s) that might be involved in leukocyte trafficking. These results indicate that CD34 plays an important role in eosinophil trafficking into the lung.     

CW operation of a InGaAsP/InP gain-coupled distributed feedback laser with a corrugated active layer

A low-threshold continuous-wave (CW)-operable gain-coupled distributed-feedback laser with a corrugated active layer was realized with InGaAsP/InP materials by implementing active ion etching and organometallic vapor-phase epitaxy. Without any phase-shifting structures, the devices exhibited excellent single-longitudinal-mode oscillation, independent of facet reflection. Threshold currents as low as 12 mA and side-mode suppression ratios as high as 55 dB were demonstrated at a wavelength of 1.55 mu m.<>     

GaAlAs/GaAs single quantum well gain-coupled distributed feedbacklaser

A novel gain-coupled distributed feedback laser with a single quantum well (SQW) active layer is proposed and fabricated. The gain perturbation for the gain coupling is due to the periodically perturbed SQW active layer. The characteristics under continuous-wave (CW) operation are presented, included an excellent single-mode property and a very high yield in the single-mode oscillation. A CW threshold current of 31 mA and a high side-mode suppression ratio of 47 dB were achieved. The high single-mode-oscillation yield near 100% indicated the dominance of the gain-coupled optical feedback in the lasers     

Photoenhancement of biogas production from thermophilic anaerobic digestion

After 46 d of anaerobic digestion at 55 degrees C, the volume of methane produced from an illuminated reactor was 2.2 times as high as that from a dark reactor. Light at a wavelength of 390-540 nm enhanced the methane production.     

河堤内非稳定渗流的实测与分析

在长期洪水渗透的作用下，堤防内的浸润线上升并到达背水坡脚，这会引起堤防内的孔隙水压力上升和非饱和状态土的强度下降，经常由此而导致堤防发生塌陷和滑动破坏。本文通过原尺寸堤防的洪水渗透试验对堤防内洪水渗透的过程和特征进行了观测，并通过对大型河堤长期洪水渗透试验的饱和-非饱和渗流的有限元解析，研究了洪水渗透的过程和特征，分析了各种条件对河堤内渗流的影响。     

Photoreaction of a ZnO gel film chemically modified with β-diketones

Chelate formation is confirmed by a red shift of the n * absorption peak of benzoylacetone (BzAcH) from 309 to 336 nm with its addition to a sol containing Zn²⁺ ions. The chelate bonds between Zn²⁺ and BzAc^– are mostly maintained in the gel film prepared from the sol. Irradiation of the gel film by a Xe lamp with a cut filter (_ex > 300 nm) in the presence of H₂O leads to decomposition of the chelate ring. As a result of the photolysis, ZnO–H groups, CH₃CHO and other carbonyl compounds are generated with the lost of CH₃ groups of the BzAc^– ligand and H₂O involved in the film. INDO/S calculations on a model complex (Zn(BzAc)(OEt)) assign the n * absorption to the electronic transition from a non-bonding molecular orbital (MO) distributed mainly at the phenyl group to an anti-bonding MO localized at the CO bonds. On the basis of these results, a photo-induced hydrolysis mechanism was presented to explain the formation of positive-type patterned ZnO films.     

Rapid electroplating of photocatalytically highly active TiO2-Zn nanocomposite films on steel

Nanocomposite films consisting of TiO₂ and Zn with thickness of 10–15 m (TiO₂-Zn) have been electrodeposited on steel plates by rapid plating from a ZnSO₄-based bath (I _d > 10 A dm^–2). Upon addition of NH₄NO₃ to the bath (<0.3 g L^–1), the uptake of TiO₂ in the film significantly increased. Glow discharge optical emission spectrometry clarified that TiO₂ particles were incorporated throughout the film and the loaded amount increased near the surface. The first-order rate constant (k/h^–1) for gas-phase CH₃CHO oxidation was employed as an indicator of the photocatalytic activity. The k value for the TiO₂-Zn film prepared at I _d = 12 A dm^–2 (0.20 h^–1) was comparable to that for the sample from a ZnCl₂-based bath at I _d = 4 A dm^–2 (0.27 h^–1). X-ray diffraction measurements indicated that a TiO₂-ZnO nanocomposite layer was generated on the surface by the heat treatment in air at 673 K for 6 h. Consequently, the photocatalytic activity was further improved (k = 0.29 h^–1); this effect was explained in terms of the synergy of TiO₂ and ZnO in photocatalysis.     

Efficient production of a functional mouse/human chimeric Fab' against human urokinase-type plasminogen activator by Bacillus brevis

Expression/secretion vectors for the production of Fab' and single-chain (sc) Fab' by Bacillus brevis have been constructed. For the production of Fab', the cDNAs encoding the L chain and Fd' fragment (Fd with the hinge region) of a mouse-human chimeric Fab' against human urokinase-type plasminogen activator were fused directly with the translation-start and signal-peptide-encoding regions of the mwp gene, the gene for one of the major cell-wall proteins of Bacillus brevis. The two fused genes were placed tandemly downstream from the promoter of the cell-wall protein gene operon (cwp) of B. brevis. For the production of scFab', the two cDNAs were linked with a synthetic oligonucleotide encoding a flexible peptide linker of 17 or 24 amino acids, and fused with the translation start and signal-peptide-encoding regions of the mwp gene. Fab' was efficiently produced by B. brevis, being accumulated at a level of 100 mg/l in the culture medium in a simple shake-flask culture, which is the highest level obtained so far for a gram-positive bacterium. On the other hand, the scFab' remained at a level of a few milligrams per liter in the culture medium. The Fab' produced by B. brevis showed comparable antigen-binding activity to that of the parental antibody. The L chain and Fd' fragment, constituting the Fab', had the correct N-terminal amino acid sequences. These results indicate that B. brevis is a very promising host for the production of native Ig fragments.     

Two cases of true hermaphrodite: the usefulness of laparoscopic gonadectomy in childhood. A case report

Laparoscopic operation has been an alternative method in not only adults but children. We presented two children with true hermaphroditism who were performed by open gonadectomy and laparoscopic gonadectomy respectively. Both patients at the age of 4, and 2 years showed karyotypes of 46, XX, and were raised as girls. In the first case left ovary and right ovotestis were revealed by open gonadal biopsy and right ovotestis was removed by open surgery. In another case bilateral ovotestes were revealed by laparoscopic gonadal biopsy and resected by laparoscopic procedure. Laparoscopy was very useful for detecting the gonadal structures to confirm the diagnosis in intersex patients. True hermaphrodite is one of uncommon intersex anomalies, therefore the diagnosis should be made to demonstrate the coexistence of both ovarian and testicular tissues definitely. We estimated laparoscopic gonadectomy in pediatric true hermaphrodite and concluded that laparoscopic gonadectomy was as profitable as open gonadectomy.