Phys Rev Lett
October 2002
Microscopic mechanisms of the puzzling insulating ferromagnetism of half-filled La4Ba2Cu2O10 are elucidated with energy-resolved Wannier states. The dominant magnetic coupling, revealed through evaluated parameters (t, U, and J), turns out to be the intersite direct exchange, a currently ignored mechanism that overwhelms the antiferromagnetic superexchange. By contrast, the isostructural Nd4Ba2Cu2O10 develops the observed antiferromagnetic order via its characteristics of a 1D chain.
View Article and Find Full Text PDFA novel picture of the quasiparticle (QP) gap in prototype semiconductors Si and Ge emerges from an analysis based on all-electron, self-consistent, GW calculations. The deep-core electrons are shown to play a key role via the exchange diagram-if this effect is neglected, Si becomes a semimetal. Contrary to current lore, the Ge 3d semicore states (e.
View Article and Find Full Text PDFA synnematous species of Penicillium, P. calidicanium, is described and illustrated. The fungus was isolated from soil in Taiwan.
View Article and Find Full Text PDFBackground: According to the high prevalence of myopia in Taiwan, we analyze the adopted cataract extractions, identify predicting factors for postoperative vision, and to assess the incidence of retinal complications after Nd: YAG laser capsulotomy in high myopic eyes.
Methods: One hundred and twenty-five eyes, which the axial lengths were longer than 26 mm, following cataract extraction were enrolled. Surgeries adopted included phacoemulsification with intraocular lens implantation, extracapsular cataract extraction with intraocular lens implantation, phacoemulsification, and extracapsular cataract extraction.
Ophthalmic Surg Lasers
January 2003
Objective: Scleral perforation is a rare complication occurring after pterygium excision often leading to scleral ulceration and loss of vision. Our purpose is to evaluate the long-term effectiveness and safety of tenonplasty and amniotic membrane transplantation in the management of scleral perforation after pterygium excision.
Patients And Methods: We performed a retrospective study on patients with scleral perforation after pterygium excision that underwent tenonplasty and amniotic membrane transplantation at Chang Gung Memorial Hospital from 1997 to 1999 and followed up for at least 12 months postoperatively.
The 1-year prevalence of neck pain and possible risk factors among university academic staff were investigated. Self-administered questionnaires were distributed to all the full-time academic staff in one of the universities in Hong Kong. The 1-year prevalence of neck pain was investigated.
View Article and Find Full Text PDFThe HNH motif was originally identified in the subfamily of HNH homing endonucleases, which initiate the process of the insertion of mobile genetic elements into specific sites. Several bacteria toxins, including colicin E7 (ColE7), also contain the 30 amino acid HNH motif in their nuclease domains. In this work, we found that the nuclease domain of ColE7 (nuclease-ColE7) purified from Escherichia coli contains a one-to-one stoichiometry of zinc ion and that this zinc-containing enzyme hydrolyzes DNA without externally added divalent metal ions.
View Article and Find Full Text PDFA sharp collective charge excitation is predicted in MgB2 at approximately 2.5 eV for q perpendicular to the boron layers, based on an all-electron analysis of the dynamical density response within time-dependent density functional theory. This novel excitation, consisting of coherent charge fluctuation between Mg and B sheets, induces an abrupt plasma edge in the experimentally observable reflectivity.
View Article and Find Full Text PDFMyotonic dystrophy type 1 (DM1) is an autosomal dominant neuromuscular disorder caused by a CTG trinucleotide expansion at the DM1 locus. In this study, we investigated the frequency distribution of various CTG repeats in normal alleles and haplotyped the normal and expanded DM1 locus in a group of Taiwanese people. In the 496 normal chromosomes examined, up to 18 alleles with different CTG lengths from 5 to 30 repeats were found and the frequency of (CTG)(>18) alleles was only 1.
View Article and Find Full Text PDFSpontaneous subconjunctival orbital fat prolapse is an uncommon but benign entity. It is seldom discussed in the literature, and is sometimes confused with other ocular surface tumors, such as dermolipoma. We present 3 cases, two of which are bilateral, the other being unilateral.
View Article and Find Full Text PDFA case is reported of a traumatic macular hole caused by a high-energy Nd:YAG laser. The initial ocular examination revealed an explosive, crater-shaped, full-thickness macular hole surrounded by local edema and detachment. By the 12th day after the injury, the hole had shrunk progressively and was covered by a thin fibrin-like membrane.
View Article and Find Full Text PDFThe conventional positive control in immunohistochemistry consists of a separately immunostained slide containing tissue known to show positive reaction with the antibody. Although it can indicate that the reagents are sound, it cannot guarantee that the appropriate reagents have indeed been dispensed in the correct order on the test cases. Furthermore, positive controls are costly because they often account for 20% to 40% of all immunostained slides in a diagnostic surgical pathology laboratory.
View Article and Find Full Text PDFLanosterol 14alpha-demethylase (CYP51) is a cytochrome P450 enzyme involved primarily in cholesterol biosynthesis. CYP51 in the presence of NADPH-cytochrome P450 reductase converts lanosterol to follicular fluid meiosis activating sterol (FF-MAS), an intermediate of cholesterol biosynthesis which accumulates in gonads and has an additional function as oocyte meiosis-activating substance. This work shows for the first time that cholesterogenic enzymes are highly expressed only in distinct stages of spermatogenesis.
View Article and Find Full Text PDFA young alcoholic and heavy smoker was admitted because of Klebsiella pneumoniae bacteremia. The abdominal and pelvic computed tomography with enhancement revealed an abscess in the right prostate. He experienced blurred vision of his left eye on the third day during admission.
View Article and Find Full Text PDFArch Ophthalmol
September 1999
Objective: To determine the incidence and type of extraocular motility disturbance after double-plate Molteno implantation.
Methods: In a prospective clinical series, we evaluated preoperative and postoperative ocular motility at 3 and 6 months in 24 eyes of 24 patients undergoing double-plate Molteno implantation. Visual acuity, motility testing, and subjective and objective diplopia were evaluated at each examination.
Background: Colicin E7 (ColE7) is one of the bacterial toxins classified as a DNase-type E-group colicin. The cytotoxic activity of a colicin in a colicin-producing cell can be counteracted by binding of the colicin to a highly specific immunity protein. This biological event is a good model system for the investigation of protein recognition.
View Article and Find Full Text PDFThe effects of dietary boron (B) (from boric acid [BA]) on bone strength were evaluated using male F344 rats. B was administered by dietary admixture of BA to NIH-07 feed at concentrations of 200, 1000, 3000, and 9000 ppm. The latter two levels were found in previous studies to be reproductively toxic to both males and the developing fetus.
View Article and Find Full Text PDFBiochem Biophys Res Commun
December 1997
Telomerase is a specialized ribonucleoprotein polymerase that adds hexanucleotides (TTAGGG) onto human chromosomal ends. The expression of telomerase activity has been associated with cell immortalization and the malignant phenotype in most cancers. How the telomerase activity is regulated in cancer cells is presently not known.
View Article and Find Full Text PDFThe tumor-suppressor gene p53 acts as "the guardian of the genome", sensing DNA damage and initiating protective responses. To examine the hypothesis that p53 abnormality leads to increased genomic alterations in primary tumor cells, our study utilized 51 primary tumors of cervical carcinoma and 10 microsatellite markers. These markers were mapped to the short arms of chromosomes 3 and 5, covering the regions 3p13-25 and 5p15.
View Article and Find Full Text PDFSite-specific cleavage of mRNA has been identified in vivo for the polycistronic colicin E7 operon (ColE7), which occurs between G and A nucleotides located at the Asp52 codon (GAT) of the immunity gene (ceiE7). In vitro, this specific cleavage occurs only in the presence of the ceiE7 gene product (ImmE7). The crystal structure of dimeric ImmE7 has been determined at 1.
View Article and Find Full Text PDFRecent investigations in our laboratory revealed divalent cation-dependent endonuclease activity in testes from 2-methoxyethanol-treated rats, which was able to cleave substrate DNA into a pattern of DNA fragmentation consisting of approximately 180-200 base pairs. Further studies were undertaken to characterize the active nuclease. F344 rats were treated with 2-methoxyethanol, a glycol ether that causes the death of pachytene spermatocytes in juvenile and adult rats.
View Article and Find Full Text PDFPrevious studies from our laboratory found that when boric acid (BA) was administered in the diet to rats, boron levels in bone were approximately fourfold greater than serum levels. The current studies were undertaken to determine if these elevations produced adverse effects on several bone-related measures, including serum electrolyte levels, bone structure, and bone strength. Data from two studies are presented: in the first study, young adult male rats consumed a powdered diet containing 0, 3000, 4500, 6000, or 9000 ppm BA for 9 weeks.
View Article and Find Full Text PDFIEEE Trans Image Process
October 2012
Two-dimensional (2-D) adaptive filtering is a technique that can be applied to many image processing applications. This paper will focus on the development of an improved 2-D adaptive lattice algorithm (2-D AL) and its application to the removal of correlated clutter to enhance the detectability of small objects in images. The two improvements proposed here are increased flexibility in the calculation of the reflection coefficients and a 2-D method to update the correlations used in the 2-D AL algorithm.
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