ADVANCED MATERIALS, Issue 2 2005
M. Nakagawa
Morphology-controlled nickel, phosphorus hollow microfibers (see Figure) have been fabricated by electroless plating using hydrogen-bonded fibrous molecular aggregates as novel morphology-tunable and recyclable templates. The inner diameter and the tubular morphology are tunable by simply varying the amphoteric azopyridine carboxylic acids forming the fibrous molecular aggregates. [source]

Hydrothermal Growth: Polymer-Templated Hydrothermal Growth of Vertically Aligned Single-Crystal ZnO Nanorods and Morphological Transformations Using Structural Polarity (Adv. Funct.

ADVANCED FUNCTIONAL MATERIALS, Issue 18 2010
Mater.
Abstract Position-configurable, vertical, single-crystalline ZnO nanorod arrays are fabricated via a polymer-templated hydrothermal growth method at a low temperature of 93 °C. A sol-gel processed dense c -oriented ZnO seed layer film is employed to grow nanorods along the c -axis direction [0001] regardless of any substrate crystal mismatches. Here, one-beam laser-interference lithography is utilized to fabricate nanoscale holes over an entire 2-in. wafer during the preparation of the polymer template. As such, vertically aligned ZnO nanorods can be grown from the seed layer exposed at the bottom of each hole. Furthermore, morphological transformations of the ZnO nanorods into pencil-like, needle-like, tubular, tree-like, and spherical shapes are obtained by controlling the growth conditions and utilizing the structural polarity of the ZnO nanorods. [source]

Polymer-Templated Hydrothermal Growth of Vertically Aligned Single-Crystal ZnO Nanorods and Morphological Transformations Using Structural Polarity

ADVANCED FUNCTIONAL MATERIALS, Issue 18 2010
Ki Seok Kim
Abstract Position-configurable, vertical, single-crystalline ZnO nanorod arrays are fabricated via a polymer-templated hydrothermal growth method at a low temperature of 93 °C. A sol-gel processed dense c -oriented ZnO seed layer film is employed to grow nanorods along the c -axis direction [0001] regardless of any substrate crystal mismatches. Here, one-beam laser-interference lithography is utilized to fabricate nanoscale holes over an entire 2-in. wafer during the preparation of the polymer template. As such, vertically aligned ZnO nanorods can be grown from the seed layer exposed at the bottom of each hole. Furthermore, morphological transformations of the ZnO nanorods into pencil-like, needle-like, tubular, tree-like, and spherical shapes are obtained by controlling the growth conditions and utilizing the structural polarity of the ZnO nanorods. [source]

Synthesis of Microporous Carbon Nanofibers and Nanotubes from Conjugated Polymer Network and Evaluation in Electrochemical Capacitor

ADVANCED FUNCTIONAL MATERIALS, Issue 13 2009
Xinliang Feng
Abstract One-dimensional fibers and tubes are constructed through the oriented carbon-carbon cross-linking reactions towards rigid conjugated polymer networks. As the result, a template-free and one-step synthesis of CNTs and CNFs is achieved through a simple carbonization of the as-formed carbon-rich tubular and fiberlike polyphenylene precursors under argon. Microporous CNTs and CNFs with a surface area up to 900 m2 g,1 are obtained, together with HR-TEM characterizations indicating the formation of intrinsic microporous structure in these rigid carbon-rich networks. The primary electrochemical experiments reveal their promising applications as advanced electrodes in electrochemical double-layered capacitor (EDLC). [source]

Pathology of peripheral intrahepatic cholangiocarcinoma with reference to tumorigenesis

HEPATOLOGY RESEARCH, Issue 4 2008
Yasuni Nakanuma
Cholangiocarcinomas (CCs) are neoplasms with cholangiocyte differentiation, and may arise from cholangiocytes of the biliary tree and possibly cholangiocyte progenitor cells. Intrahepatic CCs can be divided into the perihilar and peripheral types. Peripheral CCs present grossly as a mass forming tumor, and histologically as an adenocarcinoma of varying shapes and phenotypes. Some peripheral CCs (ductular type) are characterized by: (i) a histological resemblance to reactive bile ductules; (ii) the expression of neural cell adhesion molecule (NCAM) and vimentin. This type shows: (i) grossly, a blurred border; and (ii) histologically, carcinoma cells replacing the adjoining hepatocytes at the border of the tumor. It is frequently associated with neutrophilic infiltration and also with granulocyte and granulocyte macrophage colony-stimulating factors. We propose to call this type "ductular CC." The other peripheral CC (duct type) includes ordinary adenocarcinoma with well to moderately differentiated tubular and micropapillary patterns and is negative for NCAM but positive for mucin. This type can be called "duct CC," and shows a rather compressive growth. Interestingly, CC components of combined hepatocellular CC share the features of ductular CC, suggesting that hepatic progenitor cells may be involved in the tumorigenesis of ductular CC. The biological behavior of ductular CC and duct CC remains obscure, and follow-up and molecular studies on these tumors are required in order for these two CCs to be recognized as disease entities, and so as to evaluate their carcinogenesis. [source]

Use of neural networks for the prediction of frictional drag and transmission of axial load in horizontal wellbores

INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 2 2003
Tanvir Sadiq
Abstract The use of mud motors and other tools to accomplish forward motion of the bit in extended reach and horizontal wells allows avoiding large amounts of torque caused by rotation of the whole drill string. The forward motion of the drill string, however, is resisted by excessive amount of friction. In the presence of large compressive axial loads, the drill pipe or coiled tubing tends to buckle into a helix in horizontal boreholes. This causes additional frictional drag resisting the transmission of axial load (resulting from surface slack-off force) to the bit. As the magnitude of the frictional drag increases, a buckled pipe may become ,locked-up' making it almost impossible to drill further. In case of packers, the frictional drag may inhibit the transmission of set-up load to the packer. A prior knowledge of the magnitude of frictional drag for a given axial load and radial clearance can help avoid lock-up conditions and costly failure of the tubular. In this study a neural network model, for the prediction of frictional drag and axial load transmission in horizontal wellbores, is presented. Several neural network architectures were designed and tested to obtain the most accurate prediction. After cross-validation of the Back Propagation Neural Network (BPNN) algorithm, a two-hidden layer model was chosen for simultaneous prediction of frictional drag and axial load transmission. A comparison of results obtained from BPNN and General Regression Neural Network (GRNN) algorithms is also presented. Copyright © 2002 John Wiley & Sons, Ltd. [source]

The Electrophoretic Deposition of Lanthanum Manganite Powders for a Cathode-Supported Solid Oxide Fuel Cell in Planar and Tubular Configurations

INTERNATIONAL JOURNAL OF APPLIED CERAMIC TECHNOLOGY, Issue 6 2008
Ivana Krklju
The purpose of this research was to obtain porous, high-quality cathodes for solid oxide fuel cells in both planar and tubular shapes. To accomplish this, cathodic electrophoretic deposition of the LaMnO3 powder (synthesized by the modified sol,gel method proposed by Pechini) was performed. The optimal sintering temperatures were 1200°C and 1300°C for the tubular and planar configurations, respectively. Single-phase deposits with about 40% porosity were obtained in both configurations. The cathode quality was confirmed by depositing an electrolyte layer of YSZ. After the cosintering of both layers, an extremely dense electrolyte layer was obtained, and the cathode layer retained its high porosity. [source]

Effect of Matrigel on adenoid cystic carcinoma cell line differentiation

INTERNATIONAL JOURNAL OF EXPERIMENTAL PATHOLOGY, Issue 6 2006
Márcia M. Marques
Summary Adenoid cystic carcinoma (ACC) is a frequent malignant salivary gland neoplasm presenting different growth patterns described as tubular, cribriform and solid, which represent distinct differentiation stages. Cell lines originated from ACCs grown inside three-dimensional environments have not been capable to reproduce all in vivo ACC growth patterns. As ACC cells in vivo present replicated basement membrane, to mimic this situation in vitro ACC cells (CAC2 cells) were grown on the top of a reconstituted basement membrane (Matrigel). Phenotype differences were assessed by light, fluorescence and transmission electron microscopy. The cultures grown on the top of Matrigel presented three-dimensional arrangement of cells intercepted by cellular cords. At these, cell nests pseudocyst formations were observed. This morphological structure entirely reproduced the cribriform growth pattern of ACC. We suggest that the cribriform differentiation of ACC in culture is dependent of proteins and growth factors associated in a bi-dimensional structure. [source]

Morphological features of Murray Valley encephalitis virus infection in the central nervous system of swiss mice

INTERNATIONAL JOURNAL OF EXPERIMENTAL PATHOLOGY, Issue 1 2000
Vance Matthews
We have examined the histological and ultrastructural features of CNS infection with Murray Valley encephalitis (MVE) virus in mice inoculated with a virulent parental strain (BH3479). Light microscopic examination revealed neuronal necrosis in the olfactory bulb and hippocampus of MVE-infected brains by 5 days post-infection (pi). Electron microscopy of these regions showed endoplasmic reticulum membrane proliferation, and tubular and spherical structures in the cisternae of the endoplasmic reticulum, Golgi complex and nuclear envelope. At seven to eight days pi, infected neurones exhibited chromatin condensation and extrusion, nuclear fragmentation, loss of segments of the nuclear envelope, reduced surface contact with adjacent cells and loss of cytoplasmic organelles. This cell injury was particularly noticeable in the proximal CA3 and distal CA1 regions of the hippocampus. The inflammatory cell profile consisted of macrophages, lymphocytes and especially neutrophils, and many of these inflammatory cells were apoptotic. High mortality rates in the BH3479-infected population of mice correlated with the intense polymorphonuclear and mononuclear leucocyte inflammatory infiltrate in the CNS. [source]

A case of renal mucinous tubular and spindle cell carcinoma

INTERNATIONAL JOURNAL OF UROLOGY, Issue 8 2009
Manabu Kato
Abstract A 33-year-old man was hospitalized for treatment of a left renal tumor. The radiological findings were consistent with those of a left renal cell carcinoma (RCC). Subsequently, a radical nephrectomy was carried out. Macroscopic examination showed that a well-demarcated tumor measuring 2.9 × 2.6 × 2.5 cm was present in the middle portion of the resected kidney. The cut surface of the tumor was grayish-white in color. Pathological examination of the resected specimen showed a mucinous tubular and spindle cell carcinoma of the kidney (MTSCC-K). MTSCC-K is a low-grade renal epithelial neoplasm that has recently been recognized as a specific entity in the World Health Organization 2004 classification of RCC. To our knowledge, 17 cases of MTSCC-K in Japan have been reported by Japanese investigators. To avoid administration of excessive adjuvant treatment to patients, pathologists and urologists should consider this newly recognized low-grade malignancy when diagnosing renal tumors. [source]

A subpopulation of peritoneal macrophages form capillary-like lumens and branching patterns in vitro

JOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 3 2006
Mirela Anghelina
Abstract Objective: We have previously shown that monocytes/macrophages (MC/Mph) influence neovascularization by extracellular matrix degradation, and by direct incorporation into growing microvessels. To date, neither the phenotype of these cells, nor the stages of their capillary-like conversion were sufficiently characterized. Methods: We isolated mouse peritoneal Mph from transgenic mice expressing fluorescent proteins either ubiquitously, or specifically in the myelocytic lineage. These Mph were embedded in Matrigel which contained fluorescent protease substrates, exposed to an MCP-1 chemotactic gradient, and then examined by confocal microscopy after various intervals. Results: Within 3 hrs after gel embedding, we detected TIMP-1 and MMP-12 dependent proteolysis of the matrix surrounding Mph, mostly in the direction of high concentrations of MCP-1. After 2 days, Mph developed intracellular vacuoles containing degradation product. At 5 days these vacuoles were enlarged and/or fused to generate trans-cellular lumens in approximately 10% of cells or more (depending on animal's genetic background). At this stage, Mph became tubular, and occasionally organized in three-dimensional structures resembling branched microvessels. Conclusion: Isolated mouse peritoneal Mph penetrate Matrigel and form tunnels via a metalloprotease-driven proteolysis and phagocytosis. Following a morphological adjustment driven by occurrence, enlargement and/or fusion process of intracellular vacuoles, similar to that described in bona fide endothelium, a subpopulation of these cells end up by lining a capillary-like lumen in vitro. Thus we show that adult Mph, not only the more primitive ,endothelial progenitors', have functional properties until now considered defining of the endothelial phenotype. [source]

Enhancement of ultrafiltration using gas sparging: a comparison of different membrane modules,

JOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 2-3 2003
Zhanfeng Cui
Abstract Ultrafiltration is widely used in the chemical, pharmaceutical, food and water industries. Practical difficulties arise in designing and operating the process due to concentration polarisation and membrane fouling. Enhancement of ultrafiltration is highly desirable to achieve a higher permeate flux at a fixed energy input, or a reduced energy input whilst maintaining the level of permeate flux, or an improved selectivity of the membrane. One effective, simple, and economic technique used to enhance ultrafiltration is the use of gas bubbles, ie injecting gas into the feed stream to create a gas,liquid two-phase cross-flow operation. In this paper, an attempt is made to compare the effect of ,bubbling' on the ultrafiltration performance, using different membrane modules (in particular, tubular and hollow fibre membrane modules). The difference in performance can be related to the feature of two-phase flow hydrodynamics and its respective effect on mass transfer. The advantages and drawbacks of using this technique to enhance ultrafiltration are discussed. © 2003 Society of Chemical Industry [source]

Relationship between sonographic and pathologic findings in epidermal inclusion cysts

JOURNAL OF CLINICAL ULTRASOUND, Issue 7 2001
Hak Soo Lee MD
Abstract Purpose We evaluated the sonographic findings in epidermal inclusion cysts and related them to the pathologic findings. Methods We retrospectively reviewed the sonograms and pathology specimens of 24 patients with pathologically proven epidermal inclusion cysts. We evaluated the lesions for shape, size, internal echogenicity, posterior sound enhancement, and presence of color Doppler signals. We classified the masses into 5 sonographic types according to their internal echogenicity. The relationship between the sonographic types and the pathologic findings was examined. Results The masses were ovoid or spherical in 17 cases (71%), lobulated in 5 (21%), and tubular in 2 (8%). The longest diameter ranged from 1 to 6 cm (mean, 3.1 cm). Twenty-three cases (96%) were associated with posterior sound enhancement. Color Doppler signals were absent in 20 cases, but some vascularity was noted in 4 ruptured epidermal cysts, in areas of granulation tissue. The most common sonographic type was a hypoechoic lesion with scattered echogenic reflectors (10 cases). Sonographic findings were related to the lamellation of keratin debris and the granulation tissue secondary to rupture. Most cases with a lobulated configuration (4 of 5) or color Doppler signals (4 of 4) were ruptured cysts. Conclusions Epidermal inclusion cysts most often appeared sonographically as a hypoechoic mass containing variable echogenic foci without color Doppler signals. Ruptured epidermal cysts, however, may have lobulated contours and show color Doppler signals, mimicking a solid mass. © 2001 John Wiley & Sons, Inc. J Clin Ultrasound 29:374,383, 2001 [source]

Evaluation of pollination syndromes in Antillean Gesneriaceae: evidence for bat, hummingbird and generalized flowers

JOURNAL OF ECOLOGY, Issue 2 2009
Silvana Martén-Rodríguez
Summary 1Current views about the predominance of generalization of pollination systems have stimulated controversy concerning the validity of pollination syndromes. In order to assess the extent to which floral characters reflect selection by the most important pollinators we evaluated pollination syndromes in a florally diverse plant group, the tribe Gesnerieae, a monophyletic plant radiation from the Antillean islands. 2The study species include representatives of three groups of floral phenotypes, two of which chiefly correspond to ornithophilous and chiropterophilous syndromes. The third group includes subcampanulate flowers (characterized by a corolla constriction above the nectar chamber) with combinations of traits not fitting classic pollination syndromes. 3Pollination systems were characterized for 19 Gesnerieae species in five Antillean islands between 2003 and 2007 and supplemented with observations of four Gesneriaceae species from Costa Rica. Pollinator visitation and frequency of contact with anthers or stigmas were used to calculate an index of pollinator importance. Eleven floral traits including morphology, phenology and rewards were used to assess clustering patterns in phenotype space. 4Multidimensional scaling analysis of floral traits resulted in two clusters comprising: (i) tubular, red to yellow-flowered species with diurnal anthesis, (ii) bell-shaped-flowered species; two groups of floral phenotypes were evident within the latter cluster, campanulate nocturnal and subcampanulate flowers. Correlations between pollinator importance values and floral axes revealed strong associations with the expected pollinators, hummingbirds for tubular flowers, and bats for campanulate flowers; subcampanulate-flowered species had generalized pollination systems including bats, hummingbirds and insects. Discriminant analysis of the multivariate set of floral traits correctly classified 19 out of 23 species into the predicted pollination categories. 5Synthesis. This study provides support for classic hummingbird and bat pollination syndromes, demonstrating the importance of pollinator-mediated selection in the floral diversification of Antillean Gesnerieae. However, there was evidence for generalized pollination systems in species characterized by a unique morphological trait (corolla constriction), but with variable combinations of other floral traits. These findings suggests that floral phenotypes might also evolve under selection by various functional groups of pollinators, and underscores the importance of considering the presence and effectiveness of all floral visitors in pollination studies. [source]

The Vienna classification applied to colorectal adenomas

JOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 11 2006
Carlos A Rubio
Abstract Background and Aim:, In 1999, a group of Western and Asian pathologists gathered in Vienna reached consensus regarding the classification of gastrointestinal epithelial neoplasia. In this study, that classification is applied to colorectal adenomas. Methods:, Colorectal adenomas from 1552 patients were histologically classified according to the categories listed in Vienna: category 3, low-grade dysplasia; 4.1, high-grade dysplasia; 4.2, carcinoma in situ; 4.3, suspicious of intramucosal carcinoma; 5.1, intramucosal carcinoma; and 5.2, submucosal carcinoma. The criteria used to diagnose these lesions are described in detail. Adenomas with dysplasia (categories 3 and 4.1) or with carcinoma (categories 4.2, 4.3, 5.1 and 5.2) were analyzed separately. On basis of their configuration, adenomas were classified into tubular, tubulovillous, villous, serrated, microtubular and combined phenotypes (i.e. other than tubulovillous). Results:, The highest percentage of adenomas with carcinoma was found amongst villous adenomas (29.6%), followed by combined adenomas (27.8%). Villous adenoma with carcinoma was the most frequent neoplasia at all ages; combined adenomas with carcinoma were more frequent among younger patients. In elderly patients (,60 years of age) the highest percentage of adenomas with carcinoma was recorded in villous adenomas (28.1%), followed by serrated adenomas (19.2%). Villous adenomas and combined adenomas with carcinoma were more frequent in males. Conclusion:, The Vienna classification of colorectal adenomas seems to be influenced by parameters inherent to the patient such as age and sex and by the histological phenotype of the adenoma. With the recent improvement in medical technology it is possible to laser-microdisect a defined group of neoplastic glands (such as with carcinoma in situ or with intramucosal carcinoma) for specific molecular analysis. This modern technology will permit in future the translation of histological structures into molecular terms. [source]

Direct Coronary Stenting in Noncomplex and Noncalcified Lesions: Immediate and Mid-term Results of a Prospective Registry

JOURNAL OF INTERVENTIONAL CARDIOLOGY, Issue 4 2000
MARC BEDOSSA M.D.
Stenting of coronary arteries is currently used in clinical practice. The aim of this prospective registry was to assess the feasibility and the safety of stent implantation without balloon predilatation in noncomplex and noncalcifed lesions. One hundred six stents were implanted in 85 patients who underwent percutaneous coronary angioplasty (PTCA) of native vessels (n = 95) or bypass grafts (n = 11). The lesions were type A (21%) or B1 (79%). The stent was a tubular or a coil stent in 71 ± and 29% of the cases, respectively. The angiographic success rate was 94%. The maximal pressure was 12.1 ± 2.1 atm. In only 7 cases, it was not possible to cross the stenosis with the stent, necessitating retrieval of it and predilation with a balloon before stent implantation. Three dissections after stent implantation were treated by a second stent implantation. The primary success rate was 98% (no acute closure or myocardial infarction). A clinical follow-up was obtained in 98% of patients with a mean delay of 6 ± 0.5 months. Eighty-one percent of patients were asymptomatic. The target lesion revascularization rate was 9.4%. Four patients underwent a new PTCA and four patients a coronary artery bypass graft surgery. This technique of stent implantation appears to be safe with good immediate and midterm results. A prospective randomized trial comparing this technique to the standard technique of stent delivery in noncomplex lesions is currently ongoing with an intravascular ultrasound substudy. [source]

Morphological features and clinical feasibility of thoracic duct: Detection with nonenhanced magnetic resonance imaging at 3.0 T

JOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 1 2010
Yu De-xin MD
Abstract Purpose: To evaluate the detection of the thoracic duct using nonenhanced magnetic resonance imaging (MRI) and to determine the influence of some related disorders on the lymphatic duct. Materials and Methods: Highly fluid-sensitive sequence and fat-suppressed T2-weighted imaging (FS-T2WI) were performed in a total of 139 cases. The axial and coronal images were used to locate the thoracic duct and the measurement and evaluation of its dimensions were performed using a 3D maximum intensity projection (MIP) reconstruction image. The differences in the dimensions among control, portal hypertension, and common bile duct obstruction groups were compared using one-way analysis of variance. Results: The cisterna chyli was shown in 91% of cases on FS-T2WI, while the thoracic duct appeared in 70% of the MIP images. The common configuration of the cisterna chyli was tubular or saccular in 73%. Eighty thoracic ducts had a slight turn declining to the left at the level of T8,10. There was a significant difference in the transverse diameter of the thoracic duct between the portal hypertension group and other groups (F = 5.638, P = 0.005). Conclusion: Nonenhanced MRI is feasible for locating and depicting the morphological features of the thoracic duct. Portal hypertension may influence the dimension of the thoracic duct. J. Magn. Reson. Imaging 2010;32:94,100. © 2010 Wiley-Liss, Inc. [source]

Surface topology and structural integrity of the Theromyzon tessulatum (Annelida: Hirudinea: Glossiphoniidae) cocoon

JOURNAL OF MORPHOLOGY, Issue 7 2008
Jon'elle Coleman
Abstract Cocoons secreted by the aquatic leech Theromyzon tessulatum comprise a tubular, membranous ovoid, sealed at each end by a glue-like substance, called an operculum. Scanning electron microscopy showed surface features of the T. tessulatum cocoon that included a circuitous bulge, cups that conformed to the shape of embryos, relief folds that radiated from opercula, and asymmetric distributions of protuberances on the upper aspect of the cocoon surface. The structural integrity of the T. tessulatum cocoon was assessed after exposure to a variety of denaturing conditions (e.g., extreme heat, detergents, acids). Although both the fibrous cocoon membrane and opercula were strikingly resilient, the membrane/operculum boundary appeared to be the weakest structural component of the cocoon, consistent with its functional role as an escape hatch for juvenile leeches. The operculum itself was more sensitive to denaturation than the cocoon membrane, and thus was probably the source of a major protein component isolated from the T. tessulatum cocoon (i.e., Tcp; Theromyzon cocoon protein). J. Morphol., 2008. © 2008 Wiley-Liss, Inc. [source]

Ceramic membranes for ammonia recovery

AICHE JOURNAL, Issue 6 2006
Olivier Camus
Abstract An extensive screening program has been performed to find a suitable membrane configuration and operating conditions for the effective recovery of ammonia from the syngas loop. All the experiments have been performed at steady state. MFI zeolite membranes in tubular and multi-channel fiber configurations have been tested along with tubular silica membranes. At 80°C, a high ammonia permeance (2.1 × 10,7 mol.m,2.s,1.Pa,1), and a selectivity of about 10 were found with the tubular zeolite membrane, whereas for the silica membrane an even higher ammonia permeance was measured (7.6 x 10,7 mol.m,2.s,1.Pa,1) with a selectivity of about 7. For both silica and zeolite membranes, the selectivity was found to increase with increasing temperature up to 80°C. This is a combined effect of weaker adsorption of ammonia and increased diffusion at higher temperature. The results have been modeled using both the well-mixed reactor and the log mean pressure difference approaches. To overcome their limitations in addressing changes in feed concentration along the membrane surface, a segmental model has been used to obtain suitable operating conditions and membrane areas required for an industrial application. © 2006 American Institute of Chemical Engineers AIChE J, 2006 [source]

Protective role of ,-aminobutyric acid against chronic renal failure in rats

JOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 11 2006
Sumiyo Sasaki
The protective effect of ,-aminobutyric acid (GABA) against chronic renal failure (CRF) was investigated using a remnant kidney model with 5/6 nephrectomized rats. Nephrectomy led to renal dysfunction, which was evaluated via several parameters including serum urea nitrogen, creatinine (Cr) and Cr clearance. However, the administration of GABA ameliorated renal dysfunction, and a longer administration period of GABA increased its protective effect. In addition, nephrectomized control rats showed an elevation in the fractional excretion of sodium (FENa) with an increase in urinary sodium, while GABA led to a significant decline in FENa. Moreover, nephrectomy resulted in a decrease of serum albumin and an increase of urinary protein with a change in the urinary protein pattern, whereas the rats administered GABA showed improvement in these changes associated with CRF caused by nephrectomy. This suggests that GABA would inhibit the disease progression and have a protective role against CRF. As one of the risk factors for CRF progression, hypertension was also regulated by GABA. The results also indicate that GABA may play a protective role against CRF through improvement of the serum lipid profile, with reductions in triglyceride and total cholesterol. Furthermore, nephrectomy led to renal oxidative stress with a decrease in the activity of antioxidative enzymes and elevation of lipid peroxidation. The administration of GABA attenuated oxidative stress induced by nephrectomy through an increase in superoxide dismutase and catalase, and decrease in lipid peroxidation. The histopathological lesions, including glomerular, tubular and interstitial lesions, under nephrectomy were also improved by GABA with the inhibition of fibronectin expression. This study demonstrated that GABA attenuated renal dysfunction via regulation of blood pressure and lipid profile, and it also ameliorated the oxidative stress induced by nephrectomy, suggesting the promising potential of GABA in protecting against renal failure progression. [source]

Nanocarbon materials: probing the curvature and topology effects using phonon spectra

JOURNAL OF RAMAN SPECTROSCOPY, Issue 9 2009
Sanju Gupta
Abstract Much has been learned from the use of resonance Raman spectroscopy and high-resolution transmission electron microscopy techniques about the micro-/nanoscopic structure of various nanostructured carbons. However, they still possess some features that are not entirely understood particularly in terms of topological characteristics, which go beyond making a distinction with just the geometrical structure at nanoscale. To effectively utilize the potential of these materials for technological needs, understanding both the geometrical and topological structure and perhaps relating these attributes to physical (optical/electronic, lattice vibrational) properties become indispensable. Here, we make an attempt to describe the differences between various nanostructures and provide geometrical and topological property assessment semiquantitatively by monitoring the phonon spectra using resonance Raman spectroscopy thereby also capturing the electronic spectra. We elucidate the notion of global topology and curvature for a range of technologically important nanoscale carbons including tubular (single-, double- and multiwalled nanotubes, peapod), spherical (hypo- and hyperfullerenes, onion-like carbon) and complex (nanocones, nanohorns, nanodisks and nanorings) geometries. To demonstrate the proof-of-concept, we determined the variation in the prominent Raman bands of the respective materials, represented as D, G and D* (the overtone of D) bands, as a possible topological or curvature trend due to their sensitivity toward structural modification. The latter arises from local topological defects such as pentagons giving rise to curved nanocarbons. In this study, we provide systematics of their variation with respect to their geometric forms and compare with highly oriented pyrolytic graphite and monolayer graphene since the nanocarbons discussed are their derivatives. Once established, this knowledge will provide a powerful machinery to understand newer nanocarbons and indeed point to an unprecedented emergent paradigm of global topology/curvature , property , functionality relationship. We emphasize that these concepts are applicable to other topologically distinct nanomaterials, which include boron-nitride (BN) nanotubes and nanotori, helical gold nanotubes and Möbius conjugated organics. Copyright © 2009 John Wiley & Sons, Ltd. [source]

From Chelating Precursor to Perovskite Oxides and Hollow Fiber Membranes

JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 1 2007
S. Liu
Perovskite Ba0.5Sr0.5Co0.8Fe0.2O3-, (BSCF) is a promising mixed-conducting ceramic membrane material in addition to being a good electrode catalyst for solid oxide fuel cells. In this study, BSCF powder was synthesized via a chelated water-soluble complex method at relatively low temperatures. The combined ethylenediaminetetraacetic acid and citric acid was used for the synthesis of a complex-based precursor, followed by thermal decomposition of the precursor at high temperatures. Thermal behavior, crystal phases, and structures of the prepared powders were characterized by thermogravimetric analysis/differential scanning calorimetry, XRD, and scanning electron microscopic (SEM) techniques, respectively. Pure and single-phase perovskite could be obtained after sintering at a temperature higher than 800°C for 5 h. The soft precursor powder synthesized at lower temperatures, i.e., 600°C, is water insoluble and more appropriate for use as a membrane material to prepare gas-tight tubular or hollow fiber ceramic membranes. By contrast, the hollow fibers prepared via the traditional techniques where the perovskite powder is used as the starting membrane materials display gas leakage. The fibers were characterized by SEM, XRD, and tested for air separation at ambient pressure and temperatures between 700° and 950°C. The oxygen flux measured in this work reached 3.90 mL·(min·cm2),1 and compares favorably with any experimental values reported in the open literature. [source]

Minimal renal dysfunction in inflammatory bowel disease is related to disease activity but not to 5-ASA use

ALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 3 2001
K. R. Herrlinger
Background: Conflicting data exist about proteinuria in inflammatory bowel diseases. It is still unclear whether the occurrence of proteinuria in inflammatory bowel disease patients is an extra-intestinal manifestation of disease or the result of adverse effects to medication, especially to aminosalicylates (ASA). Methods: A total of 95 patients (51 with Crohn's disease and 44 with ulcerative colitis) were enrolled in the study. Disease activity was assessed by Crohn's Disease Activity Index (CDAI) or the Truelove index, respectively. Urine was collected over 24 h and protein excretion of specific marker proteins for tubular (,1-microglobulin-,1-MG) and glomerular (albumin-Alb, Immunoglobulin G-IgG) dysfunction was measured using a highly sensitive immunoluminometric assay. Results: Out of 51 Crohn's disease patients, 20 showed elevated urinary ,1-MG. The amount of ,1-MGuria was strongly correlated to the CDAI (r=0.6, P < 0.001). Only four Crohn's disease patients showed slightly elevated values for glomerular proteins in urine. Similar results were obtained for ulcerative colitis: whereas only two ulcerative colitis patients showed albuminuria, tubular proteinuria was detected in 28 out of 44 ulcerative colitis patients. Proteinuria was strongly dependent on disease activity (P < 0.01) but was not related to ASA treatment. Conclusions: Proteinuria of tubular marker proteins occurs in the majority of inflammatory bowel disease patients and is related to disease activity rather than to ASA treatment. Tubular proteinuria seems to reflect a renal extra-intestinal manifestation of inflammatory bowel disease and may serve as a new relevant marker of disease activity. [source]

Statins and progressive renal disease

MEDICINAL RESEARCH REVIEWS, Issue 1 2002
Michele Buemi
Abstract Thanks to the administration of hypocholesterolemic drugs, important advances have been made in the treatment of patients with progressive renal disease. In vitro and in vivo findings demonstrate that statins, the inhibitors of HMG-CoA reductase, can provide protection against kidney diseases characterized by inflammation and/or enhanced proliferation of epithelial cells occurring in rapidly progressive glomerulonephritis, or by increased proliferation of mesangial cells occurring in IgA nephropathy. Many of the beneficial effects obtained occur independent of reduced cholesterol levels because statins can directly inhibit the proliferation of different cell types (e.g., mesangial, renal tubular, and vascular smooth muscle cells), and can also modulate the inflammatory response, thus inhibiting macrophage recruitment and activation, as well as fibrosis. The mechanisms underlying the action of statins are not yet well understood, although recent data in the literature indicate that they can directly affect the proliferation/apoptosis balance, the down-regulation of inflammatory chemokines, and the cytogenic messages mediated by the GTPases Ras superfamily. Therefore, as well as reducing serum lipids, statins and other lipid-lowering agents may directly influence intracellular signaling pathways involved in the prenylation of low molecular weight proteins that play a crucial role in cell signal transduction and cell activation. Statins appear to have important potential in the treatment of progressive renal disease, although further studies are required to confirm this in humans. © 2001 John Wiley & Sons, Inc. Med Res Rev, 22, No. 1, 76,84, 2002 [source]

Transcriptional profiling using a novel cDNA array identifies differential gene expression during porcine embryo elongation

MOLECULAR REPRODUCTION & DEVELOPMENT, Issue 2 2005
So Hyun Lee
Abstract A novel porcine cDNA array, containing 1,015 PCR products selected for embryonic expression, was used for transcriptional profiling of conceptuses at four stages of peri-implantation development. Total conceptus RNA from small spherical, large spherical, tubular, and filamentous stages was amplified, converted to cDNA, and hybridized to membranes. Initially, normalized signal intensities obtained using cDNA from total RNA or from amplified RNA were compared. Uniform distribution of P -values associated with t -tests conducted for each gene indicated no evidence that amplification introduced bias. Analysis of data obtained by using amplified targets and the novel array identified genes differentially expressed across stages. Such genes were identified by testing for significant stage effects in gene-specific mixed models. A total of nine genes were declared differentially expressed. Six of the nine genes had P -values less than 0.001, and a false discovery rate of approximately 17% was associated with this significance threshold. Two out of six genes were significant when using the Bonferroni method to control the probability of one or more false positives. The other three genes had P -values between 0.001 and 0.01 and exhibited differences greater than twofold between stages. All four genes selected for confirmation (steroidogenic acute regulatory protein, interleukin 1 beta, transforming growth factor beta 3, and thymosin beta 10) were shown to be differentially expressed by using quantitative real time RT-PCR. Our study shows that RNA amplification is useful for transcriptional profiling with limiting porcine embryonic RNA, and that this novel targeted array can detect differential gene expression during trophoblastic elongation. Finally, our results contribute to an increased understanding of the temporal patterns of expression of known genes controlling conceptus development, as well as identify novel genes also differentially regulated during implantation. Mol. Reprod. Dev. 71: 129,139, 2005. © 2005 Wiley-Liss, Inc. [source]

Bunina bodies in amyotrophic lateral sclerosis

NEUROPATHOLOGY, Issue 2 2008
Koichi Okamoto
Bunina bodies, which are small eosinophilic intraneuronal inclusions in the remaining lower motor neurons, are generally considered to be a specific pathologic hallmark of amyotrophic lateral sclerosis (ALS). One year before a publication by Bunina, van Reeth et al. described similar intracytoplasmic inclusions in the anterior horn cells in a patient with Pick's dementia with atypical ALS. At present, only two proteins have been shown to be present in Bunina bodies, one is cystatin C and the other is transferrin. Bunina bodies consist of amorphous electron-dense material surrounded by tubular and vesicular structures on electron microscopy. Although the nature and significance of Bunina bodies in ALS are not yet clear, the bodies may be abnormal accumulations of unknown proteinous materials. [source]

Mechanical role of the leaf sheath in rattans

NEW PHYTOLOGIST, Issue 3 2008
S. Isnard
Summary ,,Leaf sheaths of rattans are long, tubular and persistent and unlike many self-supporting palms, extend far from the apex of the plant. The mechanical role of the leaf sheath was investigated in eight rattan species of the subfamily Calamoideae. The main objective was to analyse its influence on the mechanical architecture and contribution to the climbing habit. ,,Bending mechanical properties were measured along climbing axes before and after removal of leaf sheaths. Results were related to stem and leaf sheath geometry and mechanical properties. ,,Contribution of the leaf sheath to axial flexural rigidity was high (c. 90%) in the early stages of growth and towards the apex of older climbing axes for all climbing palms tested. Senescence and loss of the leaf sheath strongly influenced axial stiffness. A nonclimbing species, Calamus erectus, showed a different mechanical architecture. ,,Although lacking secondary growth, palms have been able to develop successful climbers with a mechanical architecture broadly analogous to, although developmentally different from, dicotyledonous lianas. The role of the leaf sheath in modulating mechanical properties during ontogeny ought not to be neglected in studies on monocotyledons, as it possibly contributed significantly to the ways in which different growth forms have evolved in the group. [source]

A new genus of Sapindaceae from Somalia

NORDIC JOURNAL OF BOTANY, Issue 5 2004
Mats Thulin
The new genus Hirania (Sapindaceae), with the single species H. rosea from south-central Somalia, is decribed and illustrated. It is a shrub with simple, entire leaves, alternate or crowded on short-shoots, and without stipules. The inflorescences are branched with monochasially arranged, unisexual flowers. The flowers (only male ones known) are zygomorphic with five sepals with gland-tipped hairs along margins, four pink, subequal, clawed petals without appendages, and eight, glabrous stamens. The dark purple disk is narrow and tubular and consists of an upper broader segment partly enclosing a lower narrower segment. The closest relative is believed to be the Australian genus Diplopeltis. [source]

Large cell calcifying Sertoli cell tumor of the testis: Comparative immunohistochemical study with Leydig cell tumor

PATHOLOGY INTERNATIONAL, Issue 6 2005
Katsuaki Sato
Large cell calcifying Sertoli cell tumor is a rare type of testicular, tumor., Reported, herein, is, a, Japanese, patient with this tumor not associated with Carney's complex. An 11-year-old boy was admitted to hospital because of left testicular enlargement, and radical orchiectomy was performed. Macroscopically, the tumor was well circumscribed and had a maximum diameter of approximately 2 cm. The cut surface showed a yellow-white solid mass. Histologically, the tumor was composed of large neoplastic cells with abundant eosinophilic cytoplasm with a tubular, trabecular, and solid arrangement and loose myxoid stroma with irregularly shaped calcification. Immunohistochemically, the tumor cells were positive for vimentin, S-100 protein, calretinin, inhibin-,, melan-A, and CD10, and type IV collagen and laminin were observed in the extracellular matrix around the tumor cells. The distributions of melan-A, CD10, and mitochondria were characteristically patchy; in contrast, they were diffusely distributed in the cytoplasm in a control case of Leydig cell tumor. The differences in immunostaining patterns for melan-A, CD10, and mitochondria as well as positivity for S-100 protein-, might be useful diagnostic hallmarks of large cell calcifying Sertoli cell tumor for discrimination from Leydig cell tumor. [source]

Blastomatous tumor with teratoid features of nasal cavity: Report of a case and review of the literature

PATHOLOGY INTERNATIONAL, Issue 1 2000
M. Salih Deveci
A case of blastomatous tumor with teratoid features is presented. The polypoid mass was observed in the left nasal cavity of a 72-year-old man. Histologically, the lesion was composed of neuroepithelial cells with blastomatous appearance, cystic squamous nests filled with keratin materials, many mucous glands, complex tubular and glandular structures with edematous fibroblastic stroma. Sinonasal neoplasms including teratoid components and immature neuroepithelium are exceedingly rare. We suggest that the term ,immature teratoma' is more suitable than blastoma or blastomatous tumor when there is no carcinomatous or sarcomatous component besides the immature neuroepithelium and teratoid elements. [source]