BackgroundThe objective of this study was to gain insight into the molecular mechanism of induced cell death (apoptosis) by PYRROLO [1,2-b][1,2,5]BENZOTHIADIAZEPINES...Full Text Available
Engineered overexpression of protein kinase Cb1; (PKCb1;) was previously shown to endow nonmotile MCF-10A human breast cells with aggressive motility. A traceable mutant of PKCb1;...Full Text Available
The activation of nuclear factor-kappa B1 (NFκB1) in cancer cells may confer resistance to ionizing radiation (IR). To enhance the therapeutic efficiency of IR in lung cancer, we screened for...Full Text Available
BackgroundThe status of estrogen receptor-b1; (ERb1;) is critical to the clinical prognosis and therapeutic approach in breast cancer. ERb1;-negative breast cancer...Full Text Available
Mutations of ephrin B1 in humans result in craniofrontonasal syndrome. Because little is known of the role and mechanism of action of ephrin B1 in bone, we examined the function of osteoblast-produced...Full Text Available
Besides differentiation and apoptosis, cellmigration is a basic process in brain development in which neural cellsmigrate several centimeters within the developing brain before reaching their proper positions and forming the right connections. For identifying signaling events that control neural migration and are therefore potential targets of chemicals to disturb normal brain development, we developed a human neurosphere-based migration assay based on normal human neural progenitor (NHNP) cells, in which the distance is measured that cells wander over time. Applying this assay, we investigated the role of the extracellular signal-regulated kinases 1 and 2 (ERK1/2) in the regulation of NHNP cellmigration. Exposure to model substances like ethanol or phorbol 12-myristate ...
ObjectiveThe goal of the study was to investigate the genetic and molecular basis of a novel syndrome of marked hyperglucagonemia and pancreatic b1; cell hyperplasia...Full Text Available
Neuroblasts born in the adult subventricular zone (SVZ) migrate long distances in the rostral migratory stream (RMS) to the olfactory bulbs where they integrate into circuitry as functional interneurons....Full Text Available
SummaryIn vivo tumor cellmigration through integrin-dependent pathways is key to the metastatic behavior of malignant cells. Using quantitative in vivo...Full Text Available
Domestic, low-level exposure to radon gas is considered a major environmental lung-cancer hazard involving DNA damage to bronchial cells by b1; particles from radon progeny. At domestic exposure...Full Text Available
Neutral endopeptidase 24.11 (NEP, CD10) is a cell-surface enzyme expressed by prostatic epithelial cells that cleaves and inactivates neuropeptides implicated in the growth of androgen-independent prostate...Full Text Available
Cells have an internal compass that enables them to move along shallow chemical gradients. As amoeboid cellsmigrate, signaling events such as Ras and PI3K activation occur spontaneously on pseudopodia....Full Text Available
Stem cell therapies for neurodegenerative disorders require accurate delivery of the transplanted cells to the sites of damage. Numerous studies have established that fluid injections to the hippocampus...Full Text Available
Experimental studies have shown that two main estrogen metabolites hydroxylated by CYP1A1 and CYP1B1 in the breast differentially affect breast cell proliferation and carcinogenesis. Although 16b1;-hydroxyestrone...Full Text Available
BackgroundThe orphan nuclear receptor estrogen-related receptor b1; (ERRb1;) is a member of the nuclear receptor superfamily. It was identified through a search for genes...Full Text Available
During development, multipotent neural precursors give rise to oligodendrocyte progenitor cells (OPCs), which migrate and divide to produce additional OPCs. Near the end of embryogenesis and...Full Text Available
The interactions between biochemical processes and mechanical signaling play important roles during various cellular processes such as wound healing, embryogenesis, metastasis, and cellmigration. While...Full Text Available
BackgroundSome breast cancer patients receiving anti-angiogenic treatment show increased metastases, possibly as a result of induced hypoxia. The effect of hypoxia on tumor cell...Full Text Available
This work reports the design of and experimentation with a topographically patterned cell culture substrate of variable local density and anisotropy as a facile and efficient platform to guide...Full Text Available
Recommended treatment of chronic hepatitis B with interferon-b1; and/or nucleos(t)ide analogues does not lead to a satisfactory result. Induction of HBV-specific T cells by therapeutic...Full Text Available
Patients with Alport syndrome progressively lose renal function as a result of defective type IV collagen in their glomerular basement membrane. In mice lacking the b1;3 chain of type IV collagen...Full Text Available
The exposure of cells to several metal ions stabilizes HIF-1b1; protein. However, the molecular mechanisms are not completely understood. They may involve inhibition of hydroxylation by either...Full Text Available
Host cells use metabolic signaling through the LXRb1; nuclear receptor to defend against Listeria monocytogenes infection. 25-Hydroxycholesterol is a natural ligand of LXRs that...Full Text Available
PurposeTo address the roles of the stromal derived factor-1 (SDF-1) b1; in the course of experimental corneal neovascularization (CNV).MethodsCNV...Full Text Available
CD44, a transmembrane receptor for hyaluronic acid, is implicated in various adhesion-dependent cellular processes, including cellmigration, tumor cell metastasis and invasion. Recent studies demonstrated that CD44 expressed in cancer cells can be proteolytically cleaved at the ectodomain by membrane type 1-matrix metalloproteinase (MT1-MMP) to form soluble CD44 and that CD44 cleavage plays a critical role in cancer cellmigration. Here, we show that transforming growth factor-b (TGF-b), a multifunctional cytokine involved in cell proliferation, differentiation, migration and pathological processes, induces MT1-MMP expression in MDA-MB-435s cells. TGF-b-induced MT1-MMP expression was blocked by the specific extracellular regulated kinase-1/2 (ERK1/2) inhibitor PD98059 and the specific pho...
Diel vertial migrations of the marine dinoflagellates Gonyaulax polyedra Stein and Ceratium furca (Ehr.) Clap. et Lachm, were followed in a laboratory tube (2.02 m x 0.25 m) under a 12:12h light:dark cycle. The effects of temperature stratification, two levels of surface irradiance and nitrogen depletion on patterns of vertical migrations were examined. At temperatures between 22 to 26/sup 0/C with small temperature gradients, both species migrated at a rate of 0.7 to 1.0 mh/sup -1/. Steeper thermoclines (ca. 0.8/sup 0/C 0.1 m/sup -1/) with temperatures below ca. 20/sup 0/C caused a marked decrease in swimming speed which resulted in accumulations of cells in these thermocline regions. Under conditions of nutrient sufficiency both algae migrated into the surface layers at irradiance values of over 1000 ..mu..E m/sup -2/s/sup -1/. Increasing nitrogen depletion caused the downward ...
Epidemiological studies have revealed that butyrate and 17?-estradiol (E2) may decrease the incidence of colorectal cancer (CRC). In peripheral tissue, E2 can be produced locally by 17?-hydroxysteroid dehydrogenase 1 (HSD17B1) estrone (E1) reduction. Using quantitative real-time polymerase chain reaction and western blotting analysis, we found that sodium butyrate significantly upregulates HSD17B1 long and short transcripts and protein levels in HT29 and SW707 CRC cells. Chromatin immunoprecipitation analysis showed that upregulation of these transcript levels correlated with an increase in binding of Polymerase II to proximal and distal promoters of HSD17B1. Moreover, we observed that upregulation of HSD17B1 protein levels was associated with increased conversion of E1 to E2 in HT29 and S...
The level of bone morphogenetic protein 2 (BMP2) profoundly influences essential cell behaviors such as proliferation, differentiation, apoptosis, and migration. The spatial and temporal pattern...Full Text Available
Deficient wound healing in diabetic patients is very frequent, but the cellular and molecular causes are poorly defined. In this study, we evaluate the hypothesis that high glucose concentrations inhibit...Full Text Available
The destiny of the mitotically active cells of the subventricular zone (SVZ) in adult rodents is to migrate to the olfactory bulb, where they contribute to the replacement of granular and periglomerular...Full Text Available
Relative doses of 75 MeV/u "1"2C ion beam after passing through different thickness of degraders were measured with the double ionization chamber method. The degrader's thickness equalized to penetration depth of the beam in water and its Bragg curve were obtained. The measured Bragg curve is compared with that calculated based on a model set up by the authors. Meanwhile, the inactivation effect of the ion beam passing through different thickness of degraders on melanoma (B_1_6) cells was measured, and the corresponding survival fraction data for B_1_6 cells were acquired
The effects of neuroactive steroids on the function of GABAA receptors were studied using cell-attached records of single channel activity recorded from HEK293 cells transfected with b1;1...Full Text Available
PurposeTo identify those metallothionein and b1;-crystallin/small heat-shock genes induced by toxic metals in human lens cells and to evaluate...Full Text Available
Estrogen metabolism is suggested to play an important role in estrogen-induced breast carcinogenesis. Epidemiologic studies suggest that diets rich in phytoestrogens are associated with a reduced risk of breast cancer. Phytoestrogens are biologically active plant compounds that structurally mimic 17b-estradiol (E2). We hypothesize that phytoestrogens, may provide protection against breast carcinogenesis by altering the expression of estrogen-metabolizing enzymes cytochrome P450 1A1 (Cyp1A1) and 1B1 (Cyp1B1). Cyp1A1 and Cyp1B1 are responsible for the metabolism of E2 to generate 2-hydroxyestradiol (2-OHE2) and 4-hydroxyestradiol (4-OHE2), respectively. Studies suggest that 2-OHE2 and 2-methoxyestradiol may protect against breast carcinogenesis, while 4-OHE2 is carcinogenic in rodent models....
In culture migrating and interacting amoeboid cells can form nematic liquid crystal phases. A polar nematic liquid crystal is formed if the interaction has a polar symmetry. One type of white blood cells (granulocytes) form clusters where the cells are oriented towards the center. The core of such an orientational defect (disclination) is either a granulocyte forced to be in an isotropic state or another cell type like a monocyte. An apolar nematic liquid crystal is formed if the interaction has an apolar symmetry. Different cell types like human melanocytes (=pigment cells of the skin), human fibroblasts (=connective tissue cells), human osteoblasts (=bone cells), human adipocytes (= fat cells) etc., form an apolar nematic liquid crystal. The orientational elastic energy is ...
Erythroid differentiation regulator (Erdr1) was first discovered in mouse leukemia cell lines and functions as a stress-related survival factor. This study investigated whether Erdr1 regulates murine melanoma progression, as well as the mechanism involved in Erdr1-regulated metastasis. The expression of Erdr1 is negatively correlated with IL-18 expression, which has a pro-cancer effect in melanoma. To study the role of Erdr1 as an anti-cancer factor, cellmigration, invasion, and proliferation were measured. Erdr1 overexpression markedly inhibited the level of cellmigration, invasion, and proliferation in B16F10 cells in vitro. In addition, Erdr1 overexpression significantly suppressed melanoma lung colonization, metastasis, and tumor growth in vivo. To identify the factors involved in Er...
The docking protein p130Cas is a prominent Src substrate found in focal adhesions (FAs) and is implicated in regulating critical aspects of cell motility including FA disassembly and protrusion of the...Full Text Available
Smooth muscle cell (SMC) proliferation and migration are key processes that occur in the pathogenesis of atherosclerosis and post-angioplasty restenosis. In the present study, we designed locked nucleic...Full Text Available
Werner syndrome (WS) is a rare disorder characterized by the premature onset of several pathologies associated with aging. The gene responsible for WS codes for a RecQ-type DNA helicase and is believed...Full Text Available
BackgroundAdipokines, e.g. TNFb1;, IL-6 and leptin increase insulin resistance, and consequent hyperinsulinaemia influences breast cancer progression. Beside its mitogenic...Full Text Available
How size is controlled is a fundamental question in biology. In this review, we discuss the use of scaling relationships—for example, power-laws of the form y∝xb1;—to...Full Text Available
Hepatocyte nuclear factor (HNF) 4b1; is a key transcription factor regulating endo/xenobiotic-metabolizing enzymes and transporters. We investigated whether microRNAs are involved in the regulation...Full Text Available
BackgroundEstrogen receptors alpha (ERb1;) and beta (ERβ) are transcription factors (TFs) that mediate estrogen signaling and define the hormone-responsive phenotype...Full Text Available
Human heat shock protein 27 (Hsp27, HspB1) is an anti-apoptotic protein characterized for its tumorigenic and metastatic properties, and now referenced as a major therapeutic target in many types of cancer. Hsp27 biochemical properties rely on a structural oligomeric and dynamic organization. Downregulation by small interfering RNA or inhibition with dominant-negative mutant have proven their efficiency to counteract the anti-apoptotic and protective properties of Hsp27. In this study, we report the isolation and characterization of Hsp27-targeted molecules interfering with its structural organization. Using the peptide aptamer (PA) strategy, we isolated PAs that specifically interact with Hsp27 and not with the other members of the small heat shock protein family. In mammalian cell cultur...
Cyclothiazomycin B1 (CTB1) is an antifungal cyclic thiopeptide isolated from the culture broth of Streptomyces sp. HA 125-40. CTB1 inhibited the growth of several filamentous fungi including plant pathogens along with swelling of hyphae and spores. The antifungal activity of CTB1 was weakened by hyperosmotic conditions, and hyphae treated with CTB1 burst under hypoosmotic conditions, indicating increased cell wall fragility. CTB1-sensitive fungal species contain high levels of cell wall chitin and/or chitosan. Unlike nikkomycin Z, a competitive inhibitor of chitin synthase (CHS), CTB1 did not inhibit CHS activity. Although CTB1 inhibited CHS biosynthesis, the same result was also obtained with a non-specific proteins inhibitor, cycloheximide, which did not reduce cell wall rigidity. These ...
Pyrrolo[2,1-c][1,4]benzodiazepine (PBD) chemicals are antitumor antibiotics inhibiting nucleic acid synthesis. An indole carboxylate-PBD hybrid with six-carbon spacer structure (IN6CPBD) has been previously demonstrated to induce melanoma cell apoptosis and reduce metastasis in mouse lungs. This study aimed at investigating the efficacy of the other hybrid compound with four-carbon spacer (IN4CPBD) and elucidating its anti-metastatic mechanism. Human melanoma A375 cells with IN4CPBD treatment underwent cytotoxicity and apoptosis-associated assays. Transwell migration assay, Western blotting, and ELISA were used for mechanistic study. IN4CPBD exhibited potent melanoma cytotoxicity through interrupting G1/S cell cycle progression, increasing DNA fragmentation and hypodipoidic DNA contents, a...
In view of the findings that several Kunitz-type protein inhibitors suppress tumor invasion and metastasis, the aim of the present study is to explore whether Bungarus multicinctus protease inhibitor-like protein-2 (PILP-2) and PILP-3 exhibit anti-tumor activity. Although approximately 28% of amino acid substitutions occurred between PILP-2 and PILP-3, molecular modeling suggested that PILP-2 and PILP-3 shared similar folded structures. Unlike PILP-2, PILP-3 showed a notable activity in abolishing migration and invasion of human neuroblastoma SK-N-SH cells. The ability of PILP-3 to inhibit matrix metalloprotease-2 (MMP-2) activity was higher than that of PILP-2. Pull-down assay revealed protein-protein interaction between PILP-3 and MMP-2. In contrast to mutation on N-terminal region, replacement of amino acids at C-terminus attenuated notably the ability of PILP-3 to inhibit cell invasion, cell ...
The in-situ observation of dendritic growth in lithium/polymer electrolyte-LiTFSI/lithium battery cells shows that dendrites grow up with about the same rate as anion migration. Memory effects have been evidenced in cycling experiments and limit the dendrites length. An overall movement of the electrolyte due to variations of electrolyte concentration in the vicinity of the electrodes has been observed too. (J.S.) 13 refs.
Several researchers have investigated morphological changes on the south-eastern Mediterranean coast during the late Holocene. However, very few of these studies include quantitative data covering the last 200?years. In this study, topographical maps, nautical charts and aerial photographs are used to estimate the shoreline migrations and beach?nearshore sand balance over the last 200?years in Haifa Bay, Israel, the northernmost final depositional sink of the Nile littoral cell. The findings reflect two main periods. During the first period, between 1799 and 1928, human intervention along the bay?s coast was negligible, a significant coastal expansion of ?50 to 150?m (averages of 0.4?1.2?m/year) was measured, and sand accumulation was estimated at ?70,000?m3 annually in the beach?nearshore...
Abstract. Objective: Lapatinib (Tykerb, GW572016), a potent inhibitor of the catalytic activities of epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2) (ErbB2), inhibits population growth of selected EGFR and HER2 overexpressing cell lines. Previous studies with a small number of cell lines suggest a correlation between overexpression of EGFR and/or HER2 and sensitivity to growth inhibition by lapatinib; however, the precise determinants of lapatinib selectivity for tumour and/or other cells remain unclear. Materials and methods: To clarify the determinants of its selectivity in cultured cells, lapatinib-induced cell population growth inhibition and relative EGFR and HER2 protein expression were quantified in 61 different human tumour cell lines fro...
In a previous study, to identify genes of importance for hepatocellular carcinogenesis, and especially for processes involved in malignant transformation, the authors investigated differences in gene expression between adenomas and carcinomas by DNA microarray. In the present study, the authors investigated AW434047, one of the sequences that was upregulated in carcinomas. The investigation led to the identification of a novel gene, which the authors named hepatocyte malignant transforming factor (HMTF), of unknown function whose expression was increased in hepatocellular carcinomas. Northern blot and in situ hybridization also demonstrated high levels of HMTF in rat hepatocellular carcinoma (HCC) cell lines, lymphocytes in the spleen, colon mucosal epithelia, spermatocytes, and granule cells of the hippocampus. Reduction of HMTF by RNA interference (RNAi) in N1 cells, an HCC cell line, caused ...
Full text: In 1995, we demonstrated the use of pretargetting three steps method and biotinylated tetracycline using radiolabelled {sup 99m}Tc-DTPA-biocytinamide for the detection of tumour cells in (C57B1/6 x BALB/C) F1 mice with E-3 thymoma. The three steps were (1) IP injection of biotinylated-tetracycline conjugate (1:1) ratio, (2) 96 hours later Avidin/Streptavidin was injected, and (3) 24 hours after (2), {sup 99m}Tc-biocytinamide -cDTPA was injected. Mice were sacrificed 16/24 h after (3) by cervical dislocation. Biodistribution of radioactivity tumour to blood, liver, bone were T:B1= 15.0, T:Li= 5.08, T:Bo=15.0. The percentage of injected dose per g was T= 3.15% and B1= 0.21%. To prolong circulation of Avidin and therefore its uptake into tumour, Avidin was covalently bound to polyethylene-glycol (PEG20 KD) at the molar ratio of ...
In mammals, primordial germ cells (PGCs) are generated in the extra-embryonic epiblast, and thereafter migrate into the developing gonads. Following the development of the gonads to the testes or ovaries, germ cells mature into sperms or eggs. In the present study, we report production and characterization of monoclonal antibodies (MAb) that recognize PGCs. Extracts from E12.5 mouse embryonic gonads were immunized as an antigen, and hybridomas were generated using the rat medial iliac lymph node method. The hybridoma supernatants were screened by immunohistochemical analyses of E12.5 mouse embryonic sections. The antibody, referred to herein as MAb 5B5, provided strong signals on PGCs. Moreover, immunofluorescence analyses using a variety of the tissue sections of mouse embryos revealed th...
A suspension of bone marrow cells from femurs of female (CBA . C57B1)F1 mice was exposed to 2450 MHz CW microwaves in a specially designed waveguide exposure system. The temperature of the suspension rose, during exposure to microwaves, from 20/sup 0/C to 45/sup 0/C, and at an interval within 20/sup 0/C to 45/sup 0/C the number of haemopoietic stem cells (CFUs) was determined by the spleen exocolony method. The time of exposure of bone marrow cells to each temperature studied was 20 s. Control suspensions of bone marrow cells were exposed to a water bath temperature. There were no significant effects of the CFUs with the water bath temperature, while after exposure to microwaves the number of spleen colonies was elevated with a nadir at the temperature of 37/sup 0/C. With a microwave-induced increase of the temperature above 41/sup 0/C the number of CFUs in the ...
PurposeTo analyze the contributions of cytochrome P4501B1 (CYP1B1) mutations to primary congenital glaucoma (PCG) in Spanish patients.MethodsWe...Full Text Available
Ionizing radiation is a standard treatment for various human solid tumors. However, several clinical studies showed that a significant proportion of patients undergoing radiotherapy for hepatocellular carcinoma (HCC) develop intrahepatic and extrahepatic metastasis. Understanding of radiation-induced cancer cell invasiveness and behavior is essential and of great important for developing suitable treatment strategies to contain cancer spread. Therefore, in this study we evaluated the effectiveness of using swept source optical coherence tomography (SS-OCT) to monitor the enhancement of HCC cell invasiveness by radiation. SS-OCT images were acquired and recorded to obtain three-dimensional data sets per four hours in 48 hours after irradiating HepG2 cells with 7.5 Gy. The cellmigration behavior in three-dimensional tissue models was quantified from images of radiation-induced and ...
In drug development, Caco-2 cells are often employed to study the influence of membrane transporters on drug permeability. The aim of the current study was to characterize permeability and kinetic parameters of selected organic anionic compounds in Caco-2 cells, and to investigate whether the Caco-2 cell line may be used as an overall model to predict interactions on multiple membrane transporters in the intestine. Taurocholic acid (TCA) and estrone-3-sulfate (E(1) S) were used as model substrates. Possible inhibitors studied were TCA, E(1) S, taurolithocholic acid, fluvastatin, and glipizide. The effects of these compounds on initial uptake, apparent permeability, and intracellular end-point accumulations of the probe substrates were studied. Both interactions on apical and basolateral influx transporters were observed. These interactions were proposed to be mediated mainly by the apical sodium-dependent bile acid ...
Both increased cell proliferation and {open_quotes}altered{close_quotes}CYP gene expression are prominent phenomena associated with liver tumor promotion by nongenotoxic carcinogen treatment. BRDU-labeled parenchymal nuclei were observed primarily in the periportal area of groups of rats, independent of nongenotoxic carcinogen treatment. Treatment with each of the 5 nongenotoxic carcinogens resulted in profound alterations in CPY gene expression at both the transcriptional and translational levels. Expression of CYP1A1, 1A1/2, 3A1, 2B1/2, and 4A immunoproteins demonstrated nongenotoxic carcinogen-specific patterns in both magnitude and zonal distribution. In agreement with the CYP immunoprotein data, treatment with each of the five nongenotoxic carcinogens resulted in a unique composition of mRNAs of CYP2B1, 2B2, 2C6, 2C11, 3A1, 3A2, and 4A1, which were variably increased or ...
The progress made during the first two years of a program to study the migration of grain boundaries in ceramic oxides is reported. The principal results of the program are concerned with the structure of grain boundaries in ..cap alpha..-Al/sub 2/O/sub 3/, although important new information has also been obtained on grain boundaries in spinels and both germanlum and silicon. Attention is focused on the basal twin boundary in ..cap alpha..-Al/sub 2/O/sub 3/ which had been identified as a model interface in early work. A series of new grain boundaries exemplified by the (11anti23) twin are also discussed briefly as is the rhombohedral twin interface. Earlier results on the first-order (..sigma..=3) twin in spinel have been extended with the development of models for the computer-simulation of high-resolution TEM images of these interfaces. A study of low-angle grain boundaries in spinel is giving new insight into the effect which the large size of the unit ...
This paper analyses Italian interregional migration flows. The approach taken is to decompose labour mobility flows into short distance and long distance migration and to model the effects of economic variables, social capital and quality of life variables, and amenity variables, on the mobility behaviour of individuals. We estimate these different types of migration flows using a negative binomial model, augmented with instruments to control for potential endogeneity issues. Our findings demonstrate that long distance migration reflects a disequilibrium model of migration whereas short distance migration largely reflects an equilibrium model of migration. As such, attempts to model interregional migration in general will be mis-specified as the simultaneously-operating underlying mobility...
We propose a combined migration velocity analysis and imaging method based on Kirchhoff integral migration and reverse time migration, using the residual curvature analysis and layer stripping strategy to build the velocity model. This method improves the image resolution of Kirchhoff integral migration and reduces the computations of the reverse time migration. It combines the advantages of efficiency and accuracy of the two migration methods. Its application in tunnel seismic prediction shows good results. Numerical experiments show that the imaging results of reverse time migration are better than the imaging results of Kirchhoff integral migration in many aspects of tunnel prediction. Field data show that this method has efficient computations and can establish a reasonable velocity model and a high quality imaging ...
Transplantation procedures using intraparenchymal injection of stem cells result in tissue injury in addition to associated surgical risks. Intravenous injection of mesenchymal stem cells gives engraftment to lesions, but the method has low efficiency and specificity. In traumatic brain injuries (TBI), there is a transient breakdown of the blood-brain barrier and an inflammatory response, which increase migration of cells from blood to parenchyma. The aim of this investigation was to analyze the effect of intra-arterial administration on cellular engraftment. Experimental TBI was produced in a rat model. Endovascular technique was used to administer human mesenchymal stem cells in the ipsilateral internal carotid artery. Evaluation of engraftment and side effects were performed by immunohistochemical analysis of the brain and several other organs. The results were compared to ...
Genome-wide association studies have linked lung cancer risk with a region of chromosome 15q25.1 containing CHRNA3, CHRNA5 and CHRNB4 encoding a3, a5 and b4 subunits of nicotinic acetylcholine receptors (nAChR), respectively. One of the strongest associations was observed for a non-silent single-nucleotide polymorphism at codon 398 in CHRNA5. Here, we have used pharmacological (antagonists) or genetic (RNA interference) interventions to modulate the activity of CHRNA5 in non-transformed bronchial cells and in lung cancer cell lines. In both cell types, silencing CHRNA5 or inhibiting receptors containing nAChR a5 with a-conotoxin MII exerted a nicotine-like effect, with increased motility and invasiveness in vitro and increasing calcium influx. The effects on motility were enhanced by addit...
We combine data from the Latin American Migration Project and the Mexican Migration Project to estimate models predicting the likelihood of taking of first and later trips to the United States...Full Text Available
Percutaneous endoscopic lumbar discectomy (PELD) for migrated disc herniations is technically demanding due to the absence of the technical guideline. The purposes of this study were to propose a radiologic...Full Text Available
Three popular imaging methods were used to carry out seismic migration from the Alberta foothills: Kirchhoff integral, reverse-time and explicit finite-difference migration methods. The imaging comparisons of reverse-time, Kirchhoff and f-x post-stack depth migration leads to the following conclusions. All of the three migration methods can provide acceptable and well-imaged intermediate results on the simplest model. Post-stack migration was not very sensitive to the accuracy of the velocity field once a reliable structural stack was available. With respect to the imaging accuracy and calculation cost, the Kirchhoff migration method seemed to be superior to reverse-time and f-x migration algorithms because its results on different kinds of velocity cases were basically kept coherent and consistent with the velocity model given by Mobil. ...
Three popular imaging methods were used to carry out seismic migration from the Alberta foothills: Kirchhoff integral, reverse-time and explicit finite-difference migration methods. The imaging comparisons of reverse-time, Kirchhoff and f-x post-stack depth migration leads to the following conclusions. All of the three migration methods can provide acceptable and well-imaged intermediate results on the simplest model. Post-stack migration was not very sensitive to the accuracy of the velocity field once a reliable structural stack was available. With respect to the imaging accuracy and calculation cost, the Kirchhoff migration method seemed to be superior to reverse-time and f-x migration algorithms because its results on different kinds of velocity cases were basically kept coherent and consistent with the velocity model given by Mobil. ...
Although acetylated b1;-tubulin is known to be a marker of stable microtubules in neurons, precise factors that regulate b1;-tubulin acetylation are, to date, largely unknown. Therefore,...Full Text Available
The distribution of b1;-galactosidase (b1;-d-galactoside galactohydrolase [EC 3.2.1.22]) in Cucurbita pepo has been determined in an attempt to assess its involvement...Full Text Available
Migration-based methods have been recently proposed to improve the estimation of angle-dependent reflectivity in the presence of complex structures. An anisotropic prestack reverse-time migration is developed to estimate the reflectivity as function of the local illumination angle. This migration method generates four simultaneous images which corresponds to the in-depth (local) plane-wave response for PP, PS, SP and SS reflections, and can be used in a Zoeppritz-based elastic inversion scheme. (author)
Inactivation of aflatoxin B1 was studied by using gamma radiation and hydrogen peroxide. A 100-krad dose of gamma radiation was sufficient to inactivate 50 micrograms of aflatoxin B1 in the presence of 5% hydrogen peroxide, and 400 krad was required for total degradation of 100 micrograms of aflatoxin in the same system. Degradation of aflatoxin B1 was confirmed by high-pressure liquid chromatographic and thin-layer chromatographic analysis. Ames microsomal mutagenicity test showed loss of aflatoxin activity. This method of detoxification also reduces the toxin levels effectively in artificially contaminated groundnuts.
Based on the wave equation theory, the authors use finite difference method to derive wave-field extrapolation formula, by which both wavefield modeling and migration can be made. The migration program VSP MIG that was developed using P-wave equation may be used to migrate both surface seismic data and VSP data. Besides, it may be applied to the migrations of P-wave data and P-SV wave data, in which case the original velocity model should be modified properly. The migrated image times for P-wave and P-SV wave respectively are absolutely equal. The migrations of upgoing P-wave and upgoing P-SV wave which have been separated can offer migrated P-wave section and migrated S-wave section. Thus, one can get more information than from simultaneous migration of P-wave and S-wave data.
Cytochrome P450 1B1 (Cyp1b1) metabolism contributes to physiological functions during embryogenesis, but also to carcinogenic activation of polycyclic aromatic hydrocarbons (PAH). We generated...Full Text Available
The mechanism of inactivation of cytochrome P450 2B1 (CYP2B1) by 4-tert-butylphenylacetylene (BPA) has been characterized previously to be caused by the covalent binding of a reactive...Full Text Available
Using a sample of 122 million Upsilon(3S) events recorded with the BaBar detector at the PEP-II asymmetric-energy e+e- collider at SLAC, we search for the h_b(1P) spin-singlet partner of the P-wave chi_b(1P) states in the sequential decay Upsilon(3S) --> pi0 h_b(1P), h_b(1P) --> gamma eta_b(1S). We observe an excess of events above background in the distribution of the recoil mass against the pi0 at mass 9902 +/- 4 (stat.) +/- 1 (syst.) MeV/c^2. The width of the observed signal is consistent with experimental resolution, and its significance is 3.0 sigma, including systematic uncertainties. We obtain the value (3.7 +/- 1.1 (stat.) +/- 0.7 (syst.))x 10^{-4} for the product branching fraction BF(Upsilon(3S) --> pi0 h_b) x BF(h_b --> gamma eta_b).
VSP reverse-time migration is a well adaptable wave equation migration method. Its control equation not only describes all-direction propagation of seismic wave but also removes interbed multiples. Clearbout's image principle is generalized to determine image conditions, real VSP data are used to determine boundary condition, and two way reflection-free wave equation is solved by making reverse-time extrapolation. In each step of extrapolation, the migration value at relevant image point is obtained by using the image condition. The complete migration of a seismic section is achieved when reverse-time extrapolation reaches the minimum image time. In this paper it is proved theoretically and practically that this method is applicable to any velocity variation and makes the migrated section have both good resolution and high S/N ratio. Besides, this method results in high ...
Three-dimensional seismic wavefields may be extrapolated in depth, one frequency at a time, by two-dimensional convolution with a circularly symmetric, frequency- and velocity-dependent filter. This depth extrapolation, performed for each frequency independently, lies at the heart of 3-D finite-difference depth migration. The computational efficiency of 3-D depth migration depends directly on the efficiency of this depth extrapolation. McClellan transformations provide an efficient method for both designing and implementing two-dimensional digital filters that have a particular form of symmetry, such as the circularly symmetric depth extrapolation filters used in 3-D depth migration. Given the coefficients of one-dimensional, frequency- and velocity-dependent filters used to accomplish 2-D depth migration, McClellan transformations lead to a simple and efficient algorithm for 3-D depth ...
Mesenchymal stem cells (MSCs) are a potential source of smooth muscle cells (SMCs) for constructing tissue-engineered vascular grafts. However, the details of how specific combinations of vascular microenvironmental factors regulate MSCs are not well understood. Previous studies have suggested that both mechanical stimulation with uniaxial cyclic strain and chemical stimulation with transforming growth factor {beta}1 (TGF-{beta}1) can induce smooth muscle markers in MSCs. In this study, we investigated the combined effects of uniaxial cyclic strain and TGF-{beta}1 stimulation on MSCs. By using a proteomic analysis, we found differential regulation of several proteins and genes, such as the up-regulation of TGF-{beta}1-induced protein ig-h3 (BGH3) protein levels by TGF-{beta}1 and up-regulation of calponin 3 protein level by cyclic strain. At the gene expression level, BGH3 was induced by TGF-{beta}1, but calponin 3 was not significantly ...
We have previously shown that budded viruses of Bombyx mori nucleopolyhedrovirus (BmNPV) enter the cell cytoplasm but do not migrate into the nuclei of non-permissive Sf9 cells that support a high titer of Autographa californica multicapsid nucleopolyhedrovirus (AcMNPV) multiplication. Here we show, using the syncytium formation assay, that low-pH-triggered membrane fusion of BmNPV GP64 protein (Bm-GP64) is significantly lower than that of AcMNPV GP64 protein (Ac-GP64). Mutational analyses of GP64 proteins revealed that a single amino acid substitution between Ac-GP64 H155 and Bm-GP64 Y153 can have significant positive or negative effects on membrane fusion activity. Studies using bacmid-based GP64 recombinant AcMNPV harboring point-mutated ac-gp64 and bm-gp64 genes showed that Ac-GP64 H155Y and Bm-GP64 Y153H substitutions decreased and increased, respectively, the multiplication and cell-to-cell spread ...
VSP data are usually recorded in common-shot gather and contain less informations. It is difficult, therefore, to obtain good migration result by using conventional migration methods. Both inner interface reflections and interformational multiples can be removed by reverse-time migration with the use of two-way nonreflection wave equation: besides, boundary reflection in VSP can be eliminated using Clayton's absorption boundary condition. It is proved that reverse-time migration is able to improve migration quality. The imaging condition is still obtained by generalizing Claerbout's imaging principle and solving eikonal equation. This is a very practical wave equation migration method. This method is applicable to prestack VSP data, conventional multiple-offset shot gather and the simultaneous migration of VSP data and ...
ObjectiveAlthough endoscopic procedures for lumbar disc diseases have improved greatly, the postoperative outcomes for high grade inferior migrated discs are not satisfactory. Because...Full Text Available
In view of the interest in the use of gamma irradiation to extend the storage life of pre-packaged foods a report is made on the effects of gamma radiation on the migration of Irganox 1076 and Irganox 1010, antioxidants present in food packaging plastics, into synthetic triglyceride fatty-food simulant HB307 and iso-octane. The extent of migration was assayed by h.p.l.c. techniques. Migration into HB307 and iso-octane decreased steadily as irradiation progressed suggesting that gamma irradiation of packaging materials helps to prevent the contamination of food by antioxidants in the packaging. (U.K.).
This paper presents a reverse time migration (RTM) method for the migration of shot records in tilted transversely isotropic (TTI) media. It is based on the tilted TI acoustic wave equation that was derived from the dispersion relation. The RTM is a full depth migration allowing for velocity to vary laterally as well as vertically and has no dip limitations. The wave equation is solved by a tenth-order finite difference scheme. Using 2D numerical models, we demonstrate that ignoring the tilt angle will introduce both lateral and vertical shifts in imaging. The shifts can be larger than 0.5 wavelength in the vertical direction and 1.5 wavelength in the lateral direction.
The results of photoemission spectroscopy using molybdenum and tantalum samples have been obtained from the new beamline 2B1 at Pohang Light Source. Beamline 2B1 is based on a spherical grating monochromator (SGM) which is equipped with five gratings. The photon energy range from 184 to 1100 eV was covered in this work using two gratings (Gratings 4 and 5). The photon energy resolution has been deduced from Ta Fermi-level spectra and 3d spectra of Mo.
Migration of protoplanets inside an accretion disc of a forming star is the most probable scenario for planetary system formation according to current models. Unsolved problems exist, concerning migration times and mechanisms. We report here the results of a 2D hydrodynamic study within an SPH scheme, analysing migration of an Earth-like or a Jupiter-like planet inside an inviscid sub-Keplerian accretion disc, as a function of the initial specific angular momentum of the infalling accretion disc matter. Particle capture by the protoplanet causes a rapid migration, within a few orbits, for the Earth like planet, and about 104 orbits for the Jupiter like planets. The effect of a planet pseudo-atmosphere is also discussed.
Recent advances in cell culture technology permit the generation of large stratified epithelial sheets appropriate for wound coverage. Autografts (sheets prepared from the patient's own skin) have proven life-saving in the treatment of large third-degree burns and have been successfully employed in the management of chronic ulcers. Allografts (sheets prepared from the skin of an unrelated donor) have also been used. In our experience, cultured allografts derived from neonatal foreskin provide a potent stimulus to healing in a variety of partial thickness wounds. Their application is a simple outpatient procedure which involves no discomfort for the patient. In contrast to autografting, no biopsy is necessary and use of cultured allogenic cells permits immediate grafts availability and possibility of stockpiling and preserving grafts for future use. Preparation of epithelial sheets suitable for grafting is also faster and easier with newborn ...
A theoretical background of crosshole reflection imaging with pre stack, multi-mode reverse time migration has been investigated. The crosshole migration has been carried out by solving two-way scalar wave equation with finite difference approximation. The wave field extrapolation was performed backward in time, with the imaging condition applied at each extrapolation time step to create partial image of the reflector. The complete migrated image was obtained by adding all the partial images from each time step. With multi-component crosshole data available, it is possible to separate the recorded data into primary P- and S-wave field. Separating wave field before migration is helpful in enhancing migrated image quality since only one wave mode can be dealt at a time with the scalar wave equation. It is possible to migrate mixed-mode primary reflections(P-S and ...
Underground injection, compared to other waste disposal methods, is considered to have the advantages of isolating wastes in a confined brine aquifer well below the horizon of human activity and underground sources of drinking water (USDWs). While most of injected wastes move laterally in the injection zone, posing a long-term concern to the human health and environment, a small amount can migrate upward to the upper aquifers, causing a greater threat to the quality of USDWs. Both the dual porosity and the single porosity models were used to investigate the migration of injected wastes through these hydrologic conduits. The results indicate that regional upward migration through an extensive confining formation is a slow process. Nevertheless, injected wastes can move upward rapidly through microannuli and channels in the cement sheath and spread over a distance in the upper aquifer. The wastes can also ...
The reversion time migration, as one of reflection seismic prospecting migration, reverse propagates a wave equation by reverse promoting the differential time, and conducts the migration. The method has such merits as no limit to the inclined angle of a reflection, correspondence to a complex topography etc. And, there is a finite difference time domain (FDTD) that uses the Maxwell equation as it is and makes a difference approximation in the methods differentiating and resolving electro-magnetic fields. It is also possible to apply the reverse time migration onto it. In this speech, using an explosive reflection face, a slope 2 layer structure and models of its reflection points are synthesized by a ground penetrating radar using the FDTD, and reverse time migration is conducted. As a result, it is clarified that the reverse time migration is valid for the ...
The efficacy of tamsulosin at the cost of a relatively benign side effect profile has been attributed to receptor selectivity directed at the b1;1a and b1;1d adrenergic...Full Text Available
b1;7 neuronal nicotinic acetylcholine receptors (b1;7-nAChR) form Ca2+-permeable homopentameric channels modulating cortical network activity and cognitive processing....Full Text Available
Background/AimsFabry disease is an X-linked recessive and progressive disease caused by b1;-galactosidase A (b1;-GaL A) deficiency. We sought to assess the prevalence...Full Text Available
AimsRosiglitazone and fenofibrate, specific agonists of the peroxisome proliferator activated receptors-γ (PPARγ) and -b1; (PPARb1;),...Full Text Available
Although peroxisome proliferator-activated receptor alpha (PPARb1;) is closely associated with myocardial fatty acid metabolism, the pathophysiological role of PPARb1; in myocardial infarction...Full Text Available
The retinoic acid receptor-related orphan receptors b1; and γ (RORb1; (NR1F1) and RORγ (NR1F3)) are orphan nuclear receptors and perform critical roles in regulation of development,...Full Text Available
Primary leaves of 7- to 9-day-old etiolated seedlings of Phaseolus vulgaris L. var. Red Kidney infiltrated in darkness with aqueous solutions of b1;, b1;′-dipyridyl,...Full Text Available
The expression status of the estrogen receptor alpha (ERb1;) and that of the epidermal growth factor receptor Her-2/neu frequently correlate inversely in breast cancers. While ERb1;-dependent...Full Text Available
b1;-Galactosidases from thermophilic organisms have gained interest owing to their applications in the sugar industry. The b1;-galactosidases AgaA, AgaB and AgaA A355E mutant from Geobacillus...Full Text Available
High reactivity toward b1;-chymotrypsin is observed for derivatives of β-arylpropionic acids of varied structure—L-b1;-acylamido compounds, D-cyclized compounds, and, now,...Full Text Available
Development of a number of original 3-D migration methods and algorithms is described. The computational efficiency of these algorithms is demonstrated by implementing them on vector and parallel supercomputers. Two-dimensional post-stack and pre-stack depth migration algorithms in the frequency - space domain using implicit finite difference method were also developed and implemented on a parallel computer, and adapted for applications that range from deep crustal imaging of seismic wavefields that involve wide ranging travel times and frequencies. All implicit finite difference migration algorithms were highly prallelized . The one pass 3-D post-stack depth migration algorithm was extensively used for imaging of seismic monitoring data from Cold Lake, Alberta. Experience shows that it provides the right trade-off between accuracy and computational efficiency. A new formulation of the 3-D reverse-time ...
Abstract High-mobility group box 1 (HMGB1), a damage-associated molecular pattern (DAMP) molecules, favors tissue regeneration via recruitment and activation of leukocytes and stem cells. Here we demonstrate, in a model of acute sterile muscle injury, that regeneration is accompanied by active reactive oxygen species (ROS) production counterbalanced and overcome by the generation of antioxidant moieties. Mitochondria are initially responsible for ROS formation. However, they undergo rapid disruption with almost complete disappearance. Twenty-four hours after injury, we observed a strong induction of MURF1 and atrogin-1 ubiquitin ligases, key signals in activation of the proteasome system and induction of muscle atrophy. At later time points, ROS generation is maintained by nonmitochondrial sources. The antioxidant response occurs in both regenerating fibers and leukocytes that express high levels of free thiols and antioxidant enzymes, such as superoxide dismutase ...
Long term integrated in situ experiments are performed in the HADES underground research facility (Mol, Belgium) in order to study the coupled reactivity between the different components of an underground repository for vitrified high level radioactive waste (HLW): glass, compacted clay, and stainless steel containers, at 90 degrees C and under gamma irradiation. Studies pertaining to the behaviour of silicon, a major element released during glass alteration, are presented here. Data collected from the integrated experiment, from simplified tests, and from modelling are put together, giving complementary information. The integrated experiment is used to investigate overall reactivity, whereas diffusion experiments coupled with modelling focused on the precipitation of silica in clay media. In the integrated in situ experiment, a bentonite clay (FoCa7) mixed with 5 wt.% of powdered glass frit was put in contact with U/Th-doped SON68 reference glass specimens for 1.2 years. One of the ...
Much of the current technology on 3D-prestack depth migration is based on the Kirchhoff method and the traveltime information needed for this purpose is obtained by the ray-theory approximation. The main motivation driving these options is to reduce computations but it can also have an adverse effect on the quality of results. Experience with real data indicates that the corresponding poststack data migrated by the reverse-time method often yields superior results. Considerable computational efficiency can be obtained by employing nonuniform coarse grid spacing during the reverse-time migration. We followed this strategy for developing a parallel scheme for doing 3D- prestack depth migration. However, we worked only on a small subset of shot gathers whose determined by the Quasi-Monte Carlo method. The results were indistinguishable from those obtained by using a much larger population of uniformly ...
Insulin receptors on the surface of isolated rat adipocytes were photoaffinity labeled at 12 degrees C with the iodinated photoreactive insulin analogue, 125I-B2 (2-nitro-4-azidophenylacetyl)-des-PheB1-insulin, and the pathways in the intracellular processing of the labeled receptors were studied at 37 degrees C. During 37 degrees C incubations, the labeled 440-kDa insulin receptors were continuously internalized (as assessed by trypsin inaccessibility) and degraded such that up to 50% of the initially labeled receptors were lost by 120 min. Metabolic poisons (0.125-0.75 mM 2,4-dinitrophenol (DNP) and 1-10 mM NaF), which led to dose-dependent depletion of adipocyte ATP pools, inhibited receptor loss, and caused up to 3-fold increase in intracellular receptor accumulation. This effect was due to inhibition of intracellular receptor degradation, and there was no apparent effect of the metabolic poisons on initial internalization of the receptors. ...
1-Furan-2-yl-3-pyridin-2-yl-propenone (FPP-3) is an anti-inflammatory agent with a propenone moiety and chemically synthesized recently. In this study, we examined the chemopreventive effect of FPP-3 on 7,12-dimethylbenz[a]anthracene (DMBA)-induced genotoxicity in MCF-7 cells. FPP-3 reduced the formation of the DMBA-DNA adduct. DMBA-induced CYP1A1 and CYP1B1 gene expression and enzyme activity were inhibited by FPP-3. It inhibited DMBA-induced aryl hydrocarbon receptor (AhR) transactivation and DMBA-inducible nuclear localization of the AhR. Induction of detoxifying phase II genes by chemopreventive agents represents a coordinated protective response against oxidative stress and neoplastic effects of carcinogens. Transcription factor NF-E2 related factor 2 (Nrf2) regulates antioxidant response element (ARE) of phase II detoxifying and antioxidant enzymes, such as glutathione S-transferase (GST) and NAD(P)H:quinone ...
One of the key issues in safety assessment of high-level nuclear waste disposal is evaluating the effects of uncertainty inherent in radionuclide migration parameter values. In this paper, radionuclide transport parameter values and error variances (uncertainties) from in-situ tracer experiments, carried out in a single fracture at the Aespoe Hard Rock Laboratory (HRL) in Sweden, are identified by solving the inverse problem in a framework of the maximum likelihood theory. From the results, it is found that the parameter value uncertainty caused by a conceptual model of radionuclide migration is greater than that caused by a fluctuation in the observed breakthrough curve data. (author)
Investigations were conducted at Los Alamos National Laboratory to quantify the extent of migration of depleted uranium away from firing sites. Extensive sampling of air particles, soil, sediment, and water was conducted to establish the magnitude of uranium contamination throughout one watershed. The uranium source term was estimated, and mass balance calculations were performed to compare the percentage of migrated uranium with original expenditures. Mass balance calculations can be powerful in identification of the extent of waste migration and used as an aid in planning future waste investigations.
Cultures of chick skin fibroblasts were dissolved in solutions of sodium dodecyl sulphate, and their entire protein content was examined by gel electrophoresis. The most abundant species migrated in...Full Text Available
BackgroundA large and increasing part of the European population has a history of migration. Germany, for example, is home to about 15 million people with migrant background, which...Full Text Available
... that range from relatively low frequency strong ground motion modeling [Vidale et al., 1985] to high frequency reverse time migration of seismic ...
into the SiC interface to form of palladium silicides (PdSix) and the subsequent migration of elemental silicon to the surface from the SiC. Palladium silicides are ...
A three-dimensional (3-D) prestack reverse-time migration algorithm for common-source P-wave data from anisotropic media is developed and illustrated by application to synthetic data. Both extrapolation of the data and computation of the excitation-time imaging condition are implemented using a second-order finite-difference solution of the 3-D anisotropic scalar-wave equation. Poorly focused, distorted images are obtained if data from anisotropic media are migrated using isotropic extrapolation; well focused, clear images are obtained using anisotropic extrapolation. A priori estimation of the 3-D anisotropic velocity distribution is required. Zones of anomalous, directionally dependent reflectivity associated with anisotropic fracture zones are detectable in both the 3-D common-source data and the corresponding migrated images.
SummaryBrown fat is specialized in energy expenditure, a process that is principally controlled by the transcriptional co-activator PGC-1b1;. Here we describe a molecular...Full Text Available
Background:Tobacco smoking is the most important risk factor for chronic obstructive pulmonary disease (COPD) development. Inhaled cigarette smoke can induce tumor necrosis factor-b1;...Full Text Available
It has been suggested for quality assurance purposes that linac output variations for helical tomotherapy (HT) be within b1;2% of the long-term average. Due to cancellation of systematic...Full Text Available
The effects of bovine b1;-globulin (BAG), bovine-ribonuclease serum albumin (BSA-RNase) and polyribonuclease (poly-RNase) complexes on the primary response of rodents to sheep erythrocytes have...Full Text Available
The purpose of this study was to determine whether resistance exercise training-induced reductions in inflammation are mediated via melanocortin 3 receptor expression in obese (BMI 32.7 b1; 3.7)...Full Text Available
PurposeDutasteride and finasteride are 5b1;-reductase inhibitors that dramatically decrease serum levels of dihydrotestosterone. Because androgens...Full Text Available
When autotrophically growing cultures of Chlorella are treated with levulinic acid, δ-aminolevulinic acid is excreted into the medium, providing a direct demonstration of b1;-aminolevulinic...Full Text Available
A series of thiazolo[3,2-b][1,2,4]triazole incorporating diphenylsulfone moieties were synthesized starting from 5-[4-(4-X-phenylsulfonyl)phenyl]-4H-1,2,4-triazole-3-thioles 3a-c, X=H, Cl, Br. Thus, alkylation of 1,2,4-triazoles 3 with phenacyl bromide or 4-bromophenacyl bromide afforded S-substituted 1,2,4-triazoles 4, 5. These new intermediates 4 and 5, in the presence of H2SO4 (c), were cyclized to 2-[4-(4-X-phenylsulfonyl)phenyl]-6-(4-Y-phenyl)[1,3]thiazolo[3,2-b]-[1, 2,4]-triazoles 6, 7 (I) and not to isomeric thiazolo[2,3-c][1,2,4]-triazoles 6, 7 (II). The newly synthesized compounds were characterized by IR, 1H, 13C NMR and elemental analysis. MS spectra confirmed the formation of thiazolo[3,2-b][1,2,4]triazole 6, 7 (forms I) in detriment of [2,3-c] isomeric compounds (forms II). Th...
The quantitative experimental uncertainty in the structure of fully hydrated, biologically relevant, fluid (Lb1;) phase lipid bilayers has been too large to...Full Text Available
A protein evolution strategy is described by which double-stranded DNA fragments encoding defined E. coli protein secondary structural elements (b1;-helices, β-strands...Full Text Available
Accumulation of certain nonmetabolizable sugar-phosphates (including b1;-methyl glucoside-6-phosphate) in Escherichia coli is growth inhibitory and elicits the glucose-phosphate...Full Text Available
A Monascus pilosus strain was selected for production of intracellular b1;-galactosidase. Optimum conditions for mycelial growth and enzyme induction were determined. Galactose...Full Text Available
PurposeRadiation-induced heart disease (RIHD) is a severe side effect of thoracic radiotherapy. This study examined the effects of PTX and b1;-tocopherol on...Full Text Available
We evaluated whether ejaculatory dysfunction induced with a selective b1;1A-blocker influenced orgasm. Fifteen healthy male volunteers took silodosin or a placebo in a randomized, double-blind...Full Text Available
The theory that the b1;β dimer is the functional unit of cooperativity in hemoglobin has been tested by determination of the oxygen equilibrium curve of stable deoxy dimers, obtained by...Full Text Available
AbstractA mechanism of how polyanions influence the channel formed by Staphylococcus aureus b1;-hemolysin is described. We demonstrate that the probability of several...Full Text Available
The structural properties of brain extracellular space (ECS) are summarised by the tortuosity (λ) and the volume fraction (b1;). To determine if these two parameters were independent,...Full Text Available
Finasteride, a specific and competitive inhibitor of 5b1;-reductase enzyme Type 2, inhibits the conversion of testosterone to dihydrotestosterone (DHT). In adults, DHT acts as primary androgen...Full Text Available
The asymmetric organocatalytic b1;-sulfenylation of substituted piperazine-2,5-diones is reported, with cinchona alkaloids as chiral Lewis bases and electrophilic sulfur transfer reagents....Full Text Available
Enolase is a multifunctional enzyme that plays important roles in many biological and disease processes. b1;-Enolase from human liver (hENO1) was expressed as a soluble protein and purified by...Full Text Available
Partial digestion of polygalacturonic acid with polygalacturonase isolated from Rhizopus stolonifer produces a mixture of b1;-1,4-d-galacturonide oligomers which act...Full Text Available
Benzodiazepine withdrawal anxiety is associated with potentiation of b1;-amino-3-hydroxy-5-methyl-4-isoxazolepropionate receptor (AMPAR) currents in hippocampal CA1 pyramidal...Full Text Available
IntroductionBRAF (v raf murine sarcoma viral oncogene homologue B1) is a serine-threonine kinase involved in the mitogen-activated protein kinase (MAPK) signalling pathway, known...Full Text Available
Ammonia adsorption on the external surface of C_3_0B_1_5N_1_5 heterofullerene was studied using density functional calculations. Three models of the ammonia-attached C_3_0B_1_5N_1_5 together with the perfect model were optimized at the B3LYP/6-31G"* level. The optimization process reveals that dramatic influences occurred for the geometrical structure of C_3_0B_1_5N_1_5 after ammonia adsorption; the B atom relaxes outwardly and consequently the heterofullerene distorts from the spherical form in the adsorption sites. The chemical shielding (CS) tensors and nuclear quadrupole coupling constants of B and N nuclei were calculated at the B3LYP/6-311G"*"* level. Our calculations reveal that the B atom is chemically bonded to NH_3 molecule. The B atom in the NH_3-attached form has the largest chemical shielding isotropic (CSI) value among the other boron nuclei. The ...
Alpha-hemoglobin-stabilizing protein (AHSP) is an erythroid-specific protein that acts as a molecular chaperone for the free b1; chains of hemoglobin. Evidence strongly suggests...Full Text Available
The accumulation of b1;-1,4-polyglucans is an important strategy to cope with transient starvation conditions in the environment. In bacteria and plants, the synthesis of glycogen and starch occurs...Full Text Available
We have previously shown that a T to G transversion at the second T of the conalbumin "TATA" box drastically decreases specific initiation of transcription by RNA polymerase B (1). We now report that...Full Text Available
Thiamin(e), also known as vitamin B1, is now known to play a fundamental role in energy metabolism. Its discovery followed from the original early research on the ‘anti-beriberi factor’...Full Text Available
In the yeast Saccharomyces cerevisiae, a and b1; mating-type information is stored in transcriptionally silenced cassettes called HML and HMR....Full Text Available
Physiological cardiac hypertrophy is associated with mitochondrial adaptations that are characterized by activation of PGC-1b1; and increased fatty acid oxidative (FAO) capacity. It is...Full Text Available
OBJECTIVESTo examine the association between b1;-blocker use and sexual dysfunction among men participating in a population-based cohort of...Full Text Available
The covered self-expandable metallic stent (SEMS) has been developed to overcome the problem of tissue ingrowth, However, stent migration is a well-known complication of covered...Full Text Available
Conceptual and factual advances in understanding neuronal migration in the past two decades have provided new insight into the pathogenesis of brain malformations at the cellular, molecular, and functional levels. Some of these results may have direct implications in understanding the consequences of ionizing radiation on the fetal central nervous system in utero. (orig.).
Elastic depth imaging of both P-wave and S-wave prestack seismic reflection data is formulated as a degraded form of Kirchhoff migration known as Wavepath Migration (WM). Applications to the SEG/EAGE salt model show that the method is sufficiently versatile anti relaitively inexpensive. It handles S-wave data with at least the same accuracy as Pwave data when local mode conversions are removed. WM also provides an understanding of multi-mode illumination.
This bibliography contains citations concerning the migration of food-packaging materials into foods. Plastic, glass, cardboard, metal, and ceramic containers are discussed. Techniques for analyzing packaging contamination are included. (Contains 90 citations fully indexed and including a title list.).
Using ab initio (SCF/6-31G) method, mechanisms of proton migrations in methaboric acid dimers have studied. It is shown that in all the dimers considered a cooperative transfer of protons occurs. The calculated values of activation barriers of cooperative proton transfer reactions in the dimers are equal to 28.6 kcal/mol.
Seventy male Wistar rats were the recipients of labeled small lymphocytes (1.5 X 10(7) each) collected from the peripheral blood of syngeneic donors. The migrating labeled lymphocytes were traced in...Full Text Available
3-D depth migration is one of the most active areas of research and development and it has been approached from different angles. An accurate algorithm which works in the space-frequency domain was introduced by Blacquiere et al. (1989). Unfortunately, it is computationally very expensive and not suitable for solving real-life 3-D migration problems. This led to the development of an alternative scheme (hale, 1990) which sacrifices some accuracy but is much more efficient. It is commonly referred to as the Hale-McClellan method. An alternative procedure known as reverse-time migration works in the space-time domain. It is based on the full wave equation and yields by far the most accurate results, but it requires extremely large computer resources. However, a series of new developments (Mufti et al, 1996) have made this algorithm a very practical tool even for migrating large exploration-scale 3-D real ...
Using an ab initio pseudopotential method within a generalized gradient approximation of the density functional theory, the structural, electronic, and phonon properties of SrS in the B1 (NaCl) and B2 (CsCl) structures have been studied. The calculated lattice constants, static bulk modulus, and first-order pressure derivative of the bulk modulus are reported for both the B1 and B2 structures and compared with previous experimental and theoretical calculations. Electronic band structures and densities of states have been derived for SrS. Subsequently, a linear-response approach to the density functional theory is used to derive the phonon frequencies and densities of states.
Formation of the soft magnetic nanostructure in amorphous Fe_1_4Ni_4_0Zr_7B_1_2 alloy due to heat treatment is studied by the Moessbauer, differential scanning calorimetry, and X-ray diffraction techniques. Annealing at temperatures 520-580 "oC leads to the formation of extremely soft nanocrystalline alloy as revealed by the rf-Moessbauer measurements. The superparamagnetic behaviour was observed for the alloy annealed at 620-640 "oC. At higher annealing temperatures good soft magnetic properties deteriorate. (author)
The room-temperature anisotropy of amorphous Fe_4_0Ni_3_8Mo_4B_1_8 (METGLAS 2628MB) ribbons after various heat treatments has been studied by Moessbauer spectroscopy. The average magnetization direction becomes significantly more out-of-plane after heating above 650 K but below the crystallization temperature. X-ray diffractograms suggest an atomic rearrangement has occurred. (orig.).
TiO{sub 2} is a vital material in several technologies including, photocatalysis, gas sensing, biomaterials and optical coatings. Among the several crystal structures of this oxide, rutile has the highest density and microhardness, the highest index of refraction and the highest temperature stability. The processing of dense polycrystalline materials often includes the addition of a liquid-forming phase at higher temperatures. This technique is known as liquid-phase sintering and has been studied extensively. Rutile boundaries containing an amorphous phase have been used to study boundary migration and grain-boundary grooving. Visible-light (VLM), scanning electron (SEM) and transmission electron microscopy (TEM) in addition to electron-backscatter diffraction (EBSD) and a focused-ion beam (FIB) tool were used to characterize boundary migration in rutile. EBSD analysis was carried out on a Philips XL30 FEG SEM equipped with a DigiView 1612 ...
Context: Our previous models of a giant planet migrating through an inner protoplanet/planetesimal disk find that the giant shepherds a portion of the material it encounters into interior orbits, whilst scattering the rest into external orbits. Scattering tends to dominate, leaving behind abundant material that can accrete into terrestrial planets. Aims: We add to the possible realism of our model by simulating type I migration forces which cause an inward drift, and strong eccentricity and inclination damping of protoplanetary bodies. This extra dissipation might be expected to enhance shepherding at the expense of scattering, possibly modifying our previous conclusions. Methods: We employ an N-body code that is linked to a viscous gas disk algorithm capable of simulating: gas accretion onto the central star; gap formation in the vicinity of the giant planet; type II migration of the giant planet; type I ...
A first-order one-way wave system has been created based on characteristic analysis of the acoustic wave system and optimization of the dispersion relation. The authors demonstrate that this system is equivalent to a third-order scalar partial-differential equation which, for a homogeneous medium, reduces to a form similar to the 45{degree} paraxial wave equation. This system describes accurately waves propagating in a 2D heterogeneous medium at angles up to 75{degree}. The one-way wave system representing downgoing waves is used for a modified reverse time migration method. As a wavefield extrapolator in migration, the downgoing wave system propagates the reflection events backwards to their reflectors without scattering at the discontinuities in the velocity model. Hence, images with amplitudes proportional to reflectivity can be obtained from this migration technique. They present examples of the application of the new ...
The standards mapping methods are limited by the lack of information between surface measures and wells profiles. The cross well seismic survey has proven being an effective high-resolution method for reservoirs characterization due its high frequency band. In this work, a 2-D finite differences algorithm for numerical cross well seismic simulation was developed, based in the approach of 2nd order for the time derivatives and 4th order for the space derivatives. In relation to the imaging techniques, it was introduced a reverse time migration method based in the solutions of the wave equation in time for cross well seismic data by the method of the finite differences exclusively. The results of reverse time migration has showed that layers with 90 cm thickness for P-waves could be visualized in migrated sections with excellent resolution. The high frequency cross well seismic data combined with reverse time ...
The release rate of a nuclide from a reactor or a radioactive waste disposal plant at the accident is not steady, but varies with time. The various parameters of a nuclide migration into environment vary also day after day, or with the seasons. In such cases, dynamic behavior of the nuclide in the environment must be taken into consideration. It is difficult for a mathematical model to involve all of mechanisms for the nuclide migration. The environment for evaluation of doses are usually divided into some of compartments in which a nuclide concentration is uniform. Time variations of the nuclide concentration in the compartment are described in simultaneous differential equations. The nuclide concentration can be solved as a time function, and the radiation doses, therefore, can be estimated as a time function. Generic analysis code for dynamic compartment model (GACOM) is developed for the nuclide migration and the ...
Early white matter (WM) injury affects brain maturation in preterm infants as revealed by diffusion tensor imaging and volumetric magnetic resonance (MR) imaging at term postmenstrual age (PMA). The aim of the study was to assess quantitatively brain maturation in preterm infants with and without milder forms of WM damage (punctate WM lesions, PWML) using conventional MRI. Brain development was quantitatively assessed using a previously validated scoring system (total maturation score, TMS) which utilizes four parameters (progressive myelination and cortical infolding, progressive involution of glial cellmigration bands and germinal matrix tissue). PWML were defined as foci of increased signal on T1-weighted images and decreased signal on T2-weighted images with no evidence of cystic degeneration. A group of 22 preterm infants with PWML at term PMA (PWML group) were compared with 22 matched controls with a normal MR appearance. The two groups ...
The extracellular matrix (ECM) of the distal tissues in a newt limb stump is completely reorganized in the 2-3-week period following amputation. In view of numerous in vitro studies showing that extracellular material influences cellular migration and proliferation, it is likely that the changes in the limb's ECM are important activities in the process leading to regeneration of such limbs. Using biochemical, autoradiographic, and histochemical techniques we studied temporal and spatial differences in the synthesis of glycosaminoglycans (GAGs) during the early, nerve-dependent phase of limb regeneration. Hyaluronic acid synthesis began with the onset of tissue dedifferentiation, became maximal within 1 weeks, and continued throughout the period of active cell proliferation. Chondroitin sulfate synthesis began somewhat later, increased steadily, and reached very high levels during chondrogenesis. During the first 10 days after amputation, ...
Food-grade PVC and PVDC/PVC films containing 28.3% dioctyladipate (DOA) and 5.0% acetyltributylcitrate (ATBC) plasticizers, respectively, were brought into contact with olive oil and were irradiated with {gamma}-radiation [{sup 60}Co] at doses equal to 4 kGy and 9 kGy corresponding to `cold pasteurization`. Irradiation was carried out at 8-10 C and samples were subsequently stored at 4-5 C. Contaminated oil samples were analysed for DOA and ATBC at intervals between 7 h and 97 h of contact, using an indirect GC method. Identical non-irradiated (control) samples were also analysed for DOA and ATBC content. Results showed no statistically significant differences in migrated amounts of DOA and ATBC between irradiated and non-irradiated samples. Neither were differences observed between samples irradiated at 4 kGy and 9 kGy. This was supported by identical IR spectra recorded for irradiated and non-irradiated samples and leads to the conclusion that at such ...
A wavelet transformation is performed over each of the spatial coordinates of the scalar wave equation. This transformed equation is solved directly with a finite-difference scheme for both homogeneous and smooth inhomogeneous media. Wavefield extrapolation is performed completely in the spatial wavelet domain without transforming back into the space domain at each time step. The wavelet coefficients are extrapolated, rather than the wavefield itself. The numerical solution of the scalar wave equation in the spatial wavelet domain is closely related to the finite-difference method because of the compact support of the wavelet bases. Poststack reverse-time migration is implemented as an application. The resolution spaces of the wavelet transform provide a natural framework for multigrid analysis. Migrated images are constructed from various resolution spaces.
The variation of surface composition and sintering of the binary Pd{sub 7}Ag{sub 3} nanoparticles prepared by chemical reduction were studied. The composition of the as-prepared Pd{sub 7}Ag{sub 3} nanoparticles across the diameter is inhomogeneous due to different reduction potentials of Pd and Ag. Upon heating, Ag will migrate to the surface because of its lower surface energy. Surface modification results in variation of surface composition during the sintering process. Stearic acid acts as a grain growth inhibitor. The migration of Ag to the surface is suppressed and the sintering is retarded. Modification by polyethylene glycol leads to more migration of Ag atoms from the core to the surface. This makes the nanoparticles easier to sinter.
The variation of surface composition and sintering of the binary Pd_7Ag_3 nanoparticles prepared by chemical reduction were studied. The composition of the as-prepared Pd_7Ag_3 nanoparticles across the diameter is inhomogeneous due to different reduction potentials of Pd and Ag. Upon heating, Ag will migrate to the surface because of its lower surface energy. Surface modification results in variation of surface composition during the sintering process. Stearic acid acts as a grain growth inhibitor. The migration of Ag to the surface is suppressed and the sintering is retarded. Modification by polyethylene glycol leads to more migration of Ag atoms from the core to the surface. This makes the nanoparticles easier to sinter.
In this article, we present our consistent efforts to explore the dynamical pathways of the migration of electronic radiation by using ultrafast (picosecond/femtosecond time scales) F?rster resonance energy transfer (FRET) technique. The ultrafast non-radiative energy migration from an intrinsic donor fluorophore (Tryptophan, Trp214) present in domain IIA of a transporter protein human serum albumin (HSA) to various non-covalently/covalently attached organic/inorganic chromophores including photoporphyrin IX (PPIX), polyoxovanadate [V15As6O42(H2O)]-6 clusters (denoted as V15) and CdS quantum dots (QDs) has been explored. We have also used other covalently/non-covalently attached extrinsic fluorogenic donors (NPA, ANS) in order to exploit the dynamics of resonance energy migration of an enz...
The Ludwig-Soret effect, the migration of a species due to a temperature gradient, has been extensively studied without a complete picture of its cause emerging. Here we investigate the dynamics of DNA and spherical particles sub jected to a thermal gradient using a combination of Brownian dynamics and the lattice Boltzmann method. We observe that the DNA molecules will migrate to colder regions of the channel, an observation also made in the experiments of Duhr, et al[1]. In fact, the thermal diffusion coefficient found agrees quantitatively with the experimental value. We also observe that the thermal diffusion coefficient decreases as the radius of the studied spherical particles increases. Furthermore, we observe that the thermal fluctuations-fluid momentum flux coupling induces a gradient in the stress which leads to thermal migration in both systems.
The space derivation term of a wave equation is accurately calculated using Fourier transform method, and the wave equation only relating to time derivative in time-space domain is derived. Solving this equation with the aid of central difference method brings the numerical recursion formula for forward modeling or reverse time migration of seismic wave field in the medium in which seismic velocity varies. The key to this method lies in introducing two auxiliary wave fields relating to velocity and spacial frequency of Fourier transform respectively after multi-dimensional Fourier transform respectively after multi-dimensional Fourier transform of space vector is made. Theoretically, this method is suitable to the forward modeling and migration of seismic wave field in complex area where seismic velocity and structure shape vary arbitrarily. Theoretical results proved this method satisfactory.
Polyethylene pipes and connections are being widely used in treated water distribution services. Migration of low molecular weight compounds from the polyethylene into the water can change its final quality. This paper is about the concentrations and identification of the migration compounds found in treated water after staying in contact with low and high-density polyethylene. Identification and quantification were carried out using CLSA (Closed Loop Stripping Analysis) extraction technique and gas chromatography coupled to mass spectrometry (HRGC/HRMS). (Author) 12 refs.
Hydrothermal systems typically consist of hot permeable rock which contains either liquid or liquid and saturated steam within the voids. These systems vent fluids at the surface through hot springs, fumaroles, mud pools, steaming ground and geysers. They are simultaneously recharged as meteoric water percolates through the surrounding rock or through the active injection of water at various geothermal reservoirs. In a number of geothermal reservoirs from which significant amounts of hot fluid have been extracted and passed through turbines, superheated regions of vapor have developed. As liquid migrates through a superheated region of a hydrothermal system, some of the liquid vaporizes at a migrating liquid-vapor interface. Using simple physical arguments, and analogue laboratory experiments we show that, under the influence of gravity, the liquid-vapor interface may become unstable and break up into fingers.
An improved method of generating angle-domain common-image gathers (ADCIGs) by VSP reverse time migration (RTM) is introduced in this paper. The formula which is used to compute the receiver wavefield for VSP RTM is modified by adding an amplitude correction term in order to conveniently output amplitude-preserved ADCIGs. Compared with the surface seismic data, VSP data contains much richer wavefields. However, the direct and downgoing waves can bring about serious imaging artifacts in ADCIGs, especially the direct wave. The feasibility and validity of this method is demonstrated by both numerical and real VSP data from western China. Thus, the ADCIGs from this method can provide reliable basic data for VSP migration velocity analysis, VSP AVO/AVA analysis, and inversion.
Thin film solar cells and solar cell testing - photovoltaic cells, radiation damage to cadmium sulfide solar cells, and airplane testing of solar cells
Abstract The term -stem cell- most commonly refers to embryonic stem cells, particularly in the lay media; however, it also describes other cell types. A stem cell represents a cell of multi-lineage potential with the ability for self-renewal. It is now clear that the plasticity and immortality of a given stem cell will depend on what type of stem cell it is, whether an embryonic stem cell, a fetal-placental stem cell or an adult stem cell. Stem cells offer great promise as cell-based therapies for the future. With evolving technology, much of the socio-political debate regarding stem cells can now be avoided.
AIM: To investigate the effects of transforming growth factor β1 (TGF-β1) on the differentiation of colonic lamina propria fibroblasts (CLPF) into myofibroblasts in vitro.METHODS:...Full Text Available
The aim of this study was to investigate the supposed vertical diel migration and the accompanying physiology of Beggiatoa bacteria from hypersaline microbial mats. We combined microsensor,...Full Text Available
Rapid changes in China over the past two decades have led to significant problems associated with population migration and changing social attitudes, including a growing sex industry and concurrent...Full Text Available
We present analytic and numerical results which illustrate the effects of Jupiter's accretion of nebular gas and the planet's radial migration on its Trojan companions. Initially, we approximate the system by the planar circular restricted three-body problem and assume small Trojan libration amplitudes. Employing an adiabatic invariant calculation, we show that Jupiter's thirty-fold growth from a $10 M_\\oplus$ core to its present mass causes the libration amplitudes of Trojan asteroids to shrink by a factor of about 2.5 to $\\sim 40%$ of their original size. The calculation also shows that Jupiter's radial migration has comparatively little effect on the Trojans; inward migration from 6.2 to 5.2 AU causes an increase in Trojan libration amplitudes of $\\sim4%$. In each case, the area enclosed by small tadpole orbits, if made dimensionless by using Jupiter's semimajor axis, is approximately conserved. Similar adiabatic ...
In addition to regulating acid secretion, the gastric antral hormone gastrin regulates several important cellular processes in the gastric epithelium including proliferation, apoptosis, migration, invasion,...Full Text Available
Due to the improvement of algorithm and the advancement of calculation performance, the imaging by depth migration before stacking is being put into practice from the viewpoint of both calculation cost and accuracy. A lot of imaging examples have been already reported from the survey areas with complicated velocity structures, such as the North Sea and the Gulf of Mexico. Effectiveness of the method has been confirmed. For imaging techniques in Japan National Oil Corporation and Japan Petroleum Exploration Co., Ltd., high-speed depth migration before stacking and high efficiency velocity structure estimation technique have been investigated. This paper describes necessary care to be taken when using depth focusing analysis (DFA) for correcting a velocity model, as an interim stage of case study. The results of depth migration before stacking using dip moveout (DMO) velocity were further inferior to the section obtained by ...
Finite-difference acoustic-wave modeling and reverse-time depth migration based on the full wave equation are general approaches that can take into account arbitrary variations in velocity and density and can handle turning waves as well. However, conventional finite-difference methods for solving the acoustic- or elastic-wave equation suffer from numerical dispersion when too few samples per wavelength are used. The flux-corrected transport (FCT) algorithm, adapted from hydrodynamics, reduces the numerical dispersion in finite-difference wavefield continuation. The flux-correction procedure endeavors to incorporate diffusion into the wavefield continuation process only where needed to suppress the numerical dispersion. Incorporating the flux-correction procedure in conventional finite-difference modeling or reverse-time migration can provide finite-difference solutions with no numerical dispersion even for impulsive sources. The FCT ...
BackgroundThis paper is based on data gathered from a 2006 survey of 1,098 "street children" in Northern Tanzania. It examines the role that school may play in preventing the migration...Full Text Available
Photon migration provides sensitive tissue oximetry in which the optical pathlength is known. Phase array gives the precise location of a subnanomolar amount of hidden absorber in highly scattering medium. PMID:8079713
This report describes mathematical predictions for the migration of radionuclides from an emplaced radioactive waste container. The model assumes a spherical-equivalent waste solid surrounded by backfill but neglects the effect of decay heat. 7 refs., 2 tabs. (TEM)
With an objective to discuss applicability of resistivity imaging using electromagnetic migration to detection of underground cavity, an applicability test was carried out on calculation of a numerical model and measurement data. By using the numerical model, a calculation was performed on a hypothetical case that a cubic cavity with sides each at 40 m exists in a homogenous medium of 200 ohm-m, with the cavity top located 20 m below the ground surface. As a result, it was possible to structure in a very short calculation time an image of the cavity which cannot be identified by one-dimensional inverse analysis. In the case of this cavity, a center of the image was structured on its lower face. It was shown that a location to indicate the image must be changed according to difference in the measurement locations. In a test on data measured in an underground cavity in the city of Utsunomiya, Tochigi Prefecture, it was found that the result may vary largely depending ...
The massive stars in the Galactic center inner arcsecond share analogous properties with the so-called Hot Jupiters. Most of these young stars have highly eccentric orbits, and were probably not formed in-situ. It has been proposed that these stars acquired their current orbits from the tidal disruption of compact massive binaries scattered toward the proximity of the central supermassive black hole. Assuming a binary star formed in a thin gaseous disk beyond 0.1 pc from the central object, we investigate the relevance of disk-satellite interactions to harden the binding energy of the binary, and to drive its inward migration. A massive, equal-mass binary star is found to become more tightly wound as it migrates inwards toward the central black hole. The migration timescale is very similar to that of a single-star satellite of the same mass. The binary's hardening is caused by the formation of spiral tails lagging the stars ...
Passage through dams is a major source of mortality of anadromous juvenile salmonids because some populations must negotiate up to eight dams in Columbia and Snake rivers. Dams cause direct mortality when fish pass through turbines, but dams may also cause indirect mortality by altering migration conditions in rivers. Forebays immediately upstream of dams have decreased the water velocity of rivers and may contribute substantially to the total migration delay of juvenile salmonids. Recently, Coutant (2001a) suggested that in addition to low water velocities, lack of natural turbulence may contribute to migration delay by causing fish to lose directional cues. Coutant (2001a) further hypothesized that restoring turbulence in dam forebays may reduce migration delay by providing directional cues that allow fish to find passage routes more quickly (Coutant 2001a). Although field experiments have yielded ...
This document outlines the major steps that must be taken by the Savannah River Site (SRS) to migrate the SRS information technology (IT) environment to the new architecture described in the Savannah River Site Computing Architecture. This document proposes an IT environment that is {open_quotes}...standards-based, data-driven, and workstation-oriented, with larger systems being utilized for the delivery of needed information to users in a client-server relationship.{close_quotes} Achieving this vision will require many substantial changes in the computing applications, systems, and supporting infrastructure at the site. This document consists of a set of roadmaps which provide explanations of the necessary changes for IT at the site and describes the milestones that must be completed to finish the migration.
A pre-stack migration algorithm for elastic waves in two-dimensional variable-velocity media is developed, implemented, and tested. The algorithm operates in the time-space domain and is based on reverse-time finite-difference extrapolation of elastic waves. The algorithm is explained and demonstrated in the context of imaging of elastic vertical seismic profile data, but is applicable to any source-recorder geometry. Synthetic test examples include a point diffractor, laterally homogeneous layers, and the flank of a salt dome.
Field experiments were conducted in the 30-km zone of Gomel's region of the Byelorussia to study factors aecting a biological radionuclide accessibility. A contamination density by radiocesium equaled 2,7-9,9 MBk/m"2, strontium 90 - 0,3-0,5 MBk/m"2 in 1991. A sowing of oats barley, lupin was carried out. It was shown that radionuclide accumulation by agricultural plants was determined basically by biological peculiarities of plants in greater degree than by the contamination density. It was shown that strontium 90 migration from the soil was more intensive than that of radiocesium. 8 tabs.
The surface composition and composition near the surface and properties of high-silica zeolites of the TsVK-1 type were studied by XPES, IRS, and low-temperature adsorption of N/sub 2/. It was found that changing the sequence of operations during preparation of the H form of the zeolites results in a different set of acid centers on their surface, caused by migration of cations into the bulk of the zeolites. Migration of elements is also observed during the catalytic reaction of conversion of ethanol.
The dual-media approach to contaminant transport modeling has emerged over the years as a clear improvement over the conventional Fickian advection-dispersion, or single-medium model, in an increasing number of settings. Recent application to the MADE-2 tracer test at Columbus Air Force Base has extended interest to field-scale plume migration in unconsolidated sediments. Subsequent application to tritium migration from the SRS F- and H-area seepage basins within this study also demonstrated improved transport predictions.
Self-expanding metallic stent insertion has been widely applied for the palliative treatment of malignant esophageal strictures. Although it is known as an easy, safe, and effective procedure, complications are well known and include things such as stent migration and esophageal stent occlusion caused by tumor in growth. However, metallic stent fractures have been rarely reported in the esophagus, especially for nitinol stents. We report a case of a stent fracture associated with migration in a patient with a malignant esophageal stricture near the gastroesophageal junction. It is highly probable that the stent fracture was due to chemical erosion of the stent caused by gastric juice
Effect of low-frequency pulsating magnetic field on the microstructure and magnetic properties of amorphous alloy Fe_7_8Si_9B_1_3 were investigated. The temperature rise induced by the treatment was measured by a non-contact infrared thermometer. The crystallization behavior and microstructure of specimens were studied by Moessbauer spectroscopy and transmission electron microscope (TEM). Magnetic properties of the specimens were investigated by alternating gradient magnetometer (AGM). The results show that the low-frequency pulsating magnetic field can promote the single-phase crystallization of amorphous alloy Fe_7_8Si_9B_1_3. The frequency, f of applied field is from 10 to 40 Hz, magnetic field, H is from 0.02 to 0.04 T and treatment duration, t is from 180-300 s. The volume fraction of crystallization phase (#alpha#-Fe(Si), the grain size, 2-10 nm) is 3-7%. The temperature rise less than 7 deg. C. ...
We investigate monoenergetic gamma-ray signatures of Z^1 dark matter annihilations in a non-minimal Universal Extra Dimensions model. The self-interactions of the non-Abelian Z^1 gauge boson give rise to a large number of contributing Feynman diagrams that do not exist for annihilations of the Abelian gauge boson B^1, which is the standard Kaluza-Klein dark matter candidate. We find that the annihilation rate is indeed considerably larger for the Z^1 than for the B^1. Even though relic density calculations indicate that the mass of the Z^1 should be larger than the mass of the B^1, the predicted fluxes are of the same order of magnitude. We compare our results to existing experimental limits, as well as to future sensitivities, for image air Cherenkov telescopes, and we find that the limits are reached already with a moderately large boost factor. However, the ...
Abstract Background & aims: Hepatitis B or C virus infection is considered to be the main cause of hepatocellular carcinoma (HCC) in Japan. Aflatoxin B1 (AFB1) is a carcinogen associated with HCC in regions with high exposure. Mutations in codon 249, exon 7 are a hallmark of AFB1 exposure. Therefore, to clarify the role of AFB1 in hepatocarcinogenesis, we examined AFB1-DNA in liver tissue and sequenced TP53 in Japanese patients with HCC. Methods: Hepatocyte AFB1-DNA adducts were determined immunohistochemically and direct sequencing of TP53 was done to determine mutations in 188 of 279 patients who underwent hepatic resection for HCC. We assessed hepatitis C virus antibodies (HCV Ab) and HBSAg expression; patients without either were defined as having non-B non-C hepatocellular carcinoma (...
VSP data are usually acquired in order to obtain high-resolution images of complex structures in reservoirs and near boreholes. The authors present an elastic iterative migration scheme which has few limitations regarding the complexity of the geology, and where the macromodel for both P- and S-wave velocities is automatically improved and updated at each iteration. They avoid wavefield separation (up/down and P/S) and the simplifying assumptions of small dips underlying most such methods. The migration scheme is based on elastic inversion theory. The wavefield extrapolation is based on a high-order, coarse-grid, finite-difference solution to the elastic two-way wave equation. At each iteration, the macromodel is updated using a gradient method, in which the gradient is computed by correlation of forward-modelled fields with back-propagated residual fields. The first iteration of the migration scheme is equivalent to ...
Three blocks of non-welded tuff, one nominally one cubic foot (trial block) and the other two, nominally one cubic metre (1 m{sup 3}), were excavated from the Busted Butte Test Facility on the Nevada Test Site and transported to the Atomic Energy of Canada Limited Whiteshell Laboratories in Pinawa, Manitoba. The trial block and one of the 1-m{sup 3} blocks were used for unsaturated flow experiments. The remaining 1-m{sup 3} block is being used for saturated flow experiments and will be reported on separately. After a vertical flow of synthetic transport solution was set up under unsaturated conditions, a suite of conservative and chemically reactive radionuclide tracers was injected at volumetric flow rates of 20 mL/hr in the trial block, and 10 mL/hr in the 1-m{sup 3} block. The duration of the migration experiment in the trial block was 87 days, while the migration experiment in the 1-m{sup 3} block was continuing after 600 days. Results ...
The transformation from the as-quenched amorphous to the crystalline state in Fe_7_8B_1_3Si_9 alloy has been investigated using a new-type neutron diffractometer. The time resolved diffraction patterns clearly show that this alloy crystallizes into FeSi alloy and Fe_2B in that order. The time evolution of these crystalline phases can be analyzed by the Kolmogorov-Johnson-Mehl-Avrami equation with the exponent of about 2.5 over a wide temperature range. This suggests that the crystallization occurs by the diffusion-controlled growth with a constant nucleation rate. The scaling behavior in the crystallization kinetics is also discussed. (author).
Human bone marrow mesenchymal stem cells (BM-MSC) are multipotent progenitor cells that have transient immunomodulatory properties on Natural Killer (NK) cells, Dendritic Cells (DC), and T cells. This...Full Text Available
Three blocks of non-welded tuff, one nominally one cubic foot (trial block) in volume and the other two, nominally one cubic meter (1 m3) in volume, were excavated from the Busted Butte Test Facility on the Nevada Test Site in 1999 and transported to the Atomic Energy of Canada Limited Whiteshell Laboratories in Pinawa, Manitoba. The trial block and one of the 1-m3 blocks were used for radionuclide migration experiments under unsaturated conditions; the remaining 1-m3 block was used for similar migration experiments under saturated conditions. After a vertical flow of synthetic transport solution was set up under unsaturated conditions, a suite of conservative and chemically reactive radionuclide tracers was injected at volumetric flow rates of 20 mL/hr in the trial block, and 10 mL/hr in two locations on the upper surface of the 1-m3 block. These flow rates correspond to infiltration rates of about 120 cm/year and about 17 cm/year, ...
Motivation: Automatic recognition of cell identities is critical for quantitative measurement, targeting and manipulation of cells of model animals at single-cell resolution. It has been...Full Text Available
Pseudomonas syringae is a gram-negative bacterial plant pathogen that is dependent on a type III protein secretion system (TTSS) and the effector proteins it translocates into plant...Full Text Available
The YTH (YT521-B homology) domain was identified by sequence comparison and is found in 174 different proteins expressed in eukaryotes. It is characterized by 14 invariant residues within an b1;-helix/β-sheet...Full Text Available
When the vehicle-treated, sham-operated mice underwent heat stress, the fraction survival and core temperature at +4 h of body heating were found to be 5 of 15 and 34.4°C b1; 0.3°C,...Full Text Available
(E)-b1;-Bisabolene synthase is one of two wound-inducible sesquiterpene synthases of grand fir (Abies grandis), and the olefin product of this cyclization reaction...Full Text Available
Two novel crystal structures of Zea mays protein kinase CK2b1; catalytic subunit, one in complex with the specific inhibitor 4,5,6,7-tetrabromobenzotriazole (TBB) and another...Full Text Available
The declaration of the human influenza A pandemic (H1N1) 2009 (H1N1/09) raised important questions, including origin and host range b;1],...Full Text Available
The requirements are given as placed on the development, procurement, maintenance, and application of software for the creation or processing of data during the design, construction, operation, repair, maintenance and safety-related upgrading of nuclear power plants. The verification and validation processes are highlighted, and the requirements put on the software documentation are outlined. The general quality assurance principles applied to safety analyses are characterized. (J.B.). 1 ref.
BackgroundTo evaluate whether P2X receptors are involved in responses to noxious pulp stimulation, the P2X3 and P2X2/3 receptor agonist b1;,β-methyleneATP...Full Text Available
FSD-1, a designed small ultrafast folder with a ββb1; fold, has been actively studied in the last few years as a model system for studying protein folding mechanisms and for testing...Full Text Available
The immunolocalization of the low density lipoprotein receptor-related protein 1 (LRP1) and its ligand alpha 2-Macroglobulin (b1;2M) was examined in tissues from human donor...Full Text Available
β-Hexachlorocyclohexane (β-HCH) is the most recalcitrant among the b1;-, β-, γ-, and δ-isomers of HCH and causes serious environmental pollution problems....Full Text Available
In this study we show the effect of anti-sulfatide (RmAb) antibodies and inflammatory cytokines, TNF-b1; and IFN-γ in inducing myelin basic protein (MBP) degradation in myelin...Full Text Available
The b1;-proteobacterial strain Sphingobium japonicum UT26 utilizes a highly chlorinated pesticide, γ-hexachlorocyclohexane (γ-HCH), as a sole source of carbon...Full Text Available
We have identified a plasmid-like element within mitochondria of Neurospora crassa strain stp-B1. It is derived from the EcoRI-4 and EcoRI-6 regions of the mitochondrial DNA, and an additional 124 bp...Full Text Available
In the isolated rat mesenteric bed, the 1 min perfusion with 100 nm anandamide, a concentration that did not evoke vasorelaxation, elicited an acute release of 165.1 b1; 9.2 pmol nitric...Full Text Available
The transcriptional co-activator PGC-1b1; regulates functional plasticity in adipose tissue by linking sympathetic input to the transcriptional program of adaptive thermogenesis. We report here...Full Text Available
Background and purpose:Theoretically, three b1;1-adrenoceptor subtypes can interact at the signalling level to alter vascular contraction or at the molecular level...Full Text Available
b1;1-Fetoprotein transcription factor (FTF), also known as liver receptor homolog 1 (LRH-1) is highly expressed in liver and intestine, where it is implicated in the regulation...Full Text Available
We studied telomeric DNA in leukemic cells as well as in normal T cells, B cells, monocytes, polymorphonuclear leukocytes, and bone marrow hematopoietic progenitor cells. No marked differences were...Full Text Available
The synovial and bone uptake of tracer in the knees of patients with rheumatoid arthritis (RA) was quantified using {sup 99}Tc{sup m}-hexamethyl propylene amine oxime-labelled leucocytes and {sup 99}Tc{sup m}-methylene diphosphonate (MDP), respectively. Significant neutrophil migration and MDP uptake occurred in the knees of patients with RA irrespective of the disease duration. In all but one patient neutrophil migration was reduced after intra-articular steroid injection. The change in MDP uptake after steroid injection was variable. There was a significant correlation between the percentage reduction in neutrophil migration and pain score, while the latter correlated poorly with the change in MDP uptake. The quantification of the neutrophil component of the inflammatory process is a sensitive index for monitoring RA activity and response to pharmacological interventions, while quantitative bone scintigraphy should not be ...
The synovial and bone uptake of tracer in the knees of patients with rheumatoid arthritis (RA) was quantified using "9"9Tc"m-hexamethyl propylene amine oxime-labelled leucocytes and "9"9Tc"m-methylene diphosphonate (MDP), respectively. Significant neutrophil migration and MDP uptake occurred in the knees of patients with RA irrespective of the disease duration. In all but one patient neutrophil migration was reduced after intra-articular steroid injection. The change in MDP uptake after steroid injection was variable. There was a significant correlation between the percentage reduction in neutrophil migration and pain score, while the latter correlated poorly with the change in MDP uptake. The quantification of the neutrophil component of the inflammatory process is a sensitive index for monitoring RA activity and response to pharmacological interventions, while quantitative bone scintigraphy should not be employed to ...
Various MLM-type (M, medium-chain fatty acids; L, long-chain fatty acids) structured triacylglycerols were produced in pilot- or small-scale packed-bed reactors by lipase-catalyzed acidolysis. The incorporation and acyl migration of octanoic acid were measured by gas chromatography and Grignard degradation, and ranged from 39.0 to 48.7% and 0.6 to 9.3%, respectively. Quantitation of triacylglycerol molecular species was performed by ammonia negative ion chemical ionization (NICI) mass spectrometry (MS). The proportion of ACN (acyl carbon number) 34 species that contained one C-18 fatty acid and two C-8:0, in samples analyzed, varied from 12.5 to 23.2%. The selected regioisomers MLM and MML within the ACN 34 species group were quantified by NICI tandem MS (MS/MS) and were in the range of 97.1 to 98.4% and 1.6 to 2.9%, respectively. There was no correlation between the level of acyl migration during lipase-catalyzed esterification and the level ...
Current theories on planetary formation establish that giant planet formation should be contextual to their quick migration towards the central star due to the protoplanets-disc interactions on a timescale of the order of $10^5$ years, for objects of nearly 10 terrestrial masses. Such a timescale should be smaller by an order of magnitude than that of gas accretion onto the protoplanet during the hierarchical growing-up of protoplanets by collisions with other minor objects. These arguments have recently been analysed using N-body and/or fluid-dynamics codes or a mixing of them. In this work, inviscid 2D simulations are performed, using the SPH method, to study the migration of one protoplanet, to evaluate the effectiveness of the accretion disc in the protoplanet dragging towards the central star, as a function of the mass of the planet itself, of disc tangential kinematics and of the presence of a planet ``pseudo-atmosphere''. To this ...
We present our initial experience with a new biodegradable (BD) esophageal stent in two patients, one for a therapy-resistant benign esophageal stricture, and the other as a temporary measure during curative radiotherapy for oesophageal carcinoma. The BD stents need to be loaded into a conventional pull-back delivery system but are then placed in a standard fashion. Pre-dilatation should be avoided to reduce the risk of migration, however if migration occurs the stents can be left to dissolve in the stomach. The stents are radiolucent but easily identified on CT with minimal artefact and thus might even aid with radiotherapy planning. BD stents offer an exciting new strategy for therapy-resistant benign strictures as well as a supportive measure for oesophageal cancer undergoing non-surgical treatment. (orig.)
Stage III and stage IV recovery have been investigated resistometrically following 6.1 MeV alpha-particle irradiation at 4.2 K. The activation energy associated with stage III shows a gradual increase from 0.35 +- 0.02 eV to 0.39 +- 0.02 eV. Stage IV (155 to 180 K) is associated with an activation energy of 0.46 +- 0.03 eV. The present results are compared with those obtained after electron and neutron irradiation. The stage III recovery kinetics are interpreted in terms of the Goesele-Seeger theory for interstitial migration in highly anisotropic hexagonal metals. Stage IV is ascribed to monovacancy migration. (author).
We present here a study based on the migration of protoplanets in an accretion disc of a forming star, as the mainly proposed scenario for the formation of planetary systems. Attention is here focused on the mutual interactions between two protoplanets, both embedded in the accretion disc, as a function of the protoplanets masses, their relative positions, the dynamic properties of the accretion disc particles. The study is performed through a 2D SPH code and preliminary results show an oscillation of the distance between the two protoplanets, together with a slow migration of the two planets towards the central star when two Jupiter-like planets are considered. Less correlated behaviour is observed when at least one of the two protoplanets has an Earth-like mass. The role played by the disc particles initial angular momentum is discussed.
The forward modelling and the prestack reverse time migration of seismic P-SV wave field was carried out in 2-D models of isotropic and anisotropic media which allow separation of P-SV and SH motion. The P-SV wave field can be described by a system of hyperbolic, first order differential equations in terms of particle velocity and stress. The system of five equations and five unknowns, namely horizontal (U) and vertical (V) velocity components, and three components of stress (T{sub xx}, T-z{sub z} and T{sub xz}) was solved numerically using second order space and forth order time finite differences operators. In order to attenuate numerical dispersion, a staggered grid was used. (author). 48 refs., 5 figs
We propose a new algorithm for two-dimensional magnetotelluric (MT) inversion. Our algorithm is an MT inversion based on the steepest descent method, borrowed from the backpropagation technique of seismic inversion or reverse time migration, introduced in the middle 1980s by Lailly and Tarantola. The steepest descent direction can be calculated efficiently by using the symmetry of numerical Green's function derived from a mixed finite element method proposed by Nedelec for Maxwell's equation, without calculating the Jacobian matrix explicitly. We construct three different objective functions by taking the logarithm of the complex apparent resistivity as introduced in the recent waveform inversion algorithm by Shin and Min. These objective functions can be naturally separated into amplitude inversion, phase inversion and simultaneous inversion. We demonstrate our algorithm by showing three inversion results for synthetic data.
The authors determined migration timing and abundance of juvenile spring chinook salmon Oncorhynchus tshawytscha and juvenile steelhead/rainbow trout O. mykiss from three populations in the Grande Ronde River basin. Based on migration timing and abundance, two distinct life-history strategies of juvenile spring chinook and O.mykiss could be distinguished. An early migrant group left upper rearing areas from July through January with a peak in the fall. A late migrant group descended from upper rearing areas from February through June with a peak in the spring.
The effect on human health of using food packaging made from recycled materials will depend on whether the elements will migrate into the food itself and at which levels that would be of concern. There is no EU directive for paper and board packaging, but guidelines on paper and board intended to come into contact with food are being developed in another forum. These do not propose limits for paper intended to come into contact with dry foods. However, for other foodstuffs, restriction limits in paper of 0.002 mg/dm"2 (Cd), 0.003 mg/dm"2 (Pb), and 0.002 mg/dm"2 (Hg) have been proposed. This paper describes a radiotracer method that has been applied to the determination of migration of trace elements from paper and board into real food samples.
Four interrelated projects are underway whose purpose is to migrate the LAMPF-PSR Accelerator Complex control systems to a system with a common set of hardware and software components. Project goals address problems in performance, maintenance and growth potential. Front-end hardware, operator interface hardware and software, computer systems, network systems and data system software are being simultaneously upgraded as part of these efforts. The efforts are being coordinated to provide for a smooth and timely migration to a client-sever model-based data acquisition and control system. An increased use of the distributed intelligence at both the front-end and operator interface is a key element of the projects. 2 refs., 2 figs.
Mesopelagic zooplankton may meet their nutritional and metabolic requirements in a number of ways including consumption of sinking particles, carnivory, and vertical migration. How these feeding modes change with depth or location, however, is poorly known. We analyzed fatty acid (FA) profiles to characterize zooplankton diet and large particle (>51?m) composition in the mesopelagic zone (base of euphotic zone ?1000m) at two contrasting time-series sites in the subarctic (station K2) and subtropical (station ALOHA) Pacific Ocean. Total FA concentration was 15.5 times higher in zooplankton tissue at K2, largely due to FA storage by seasonal vertical migrators such as Neocalanus and Eucalanus. FA biomarkers specific to herbivory implied a higher plant-derived food sou...
Ab initio planewave pseudopotential method is used to study carbon diffusion and pairing in crystalline silicon. The calculation is performed with a 40 Ry planewave cutoff and 2x2x2 special k-point sampling with a supercell of 64 atoms. It is found that substitutional carbon attracts interstitial Si forming a <001> C interstitial with a large binding energy of 1.45 eV. The interstitial carbon is mobile and can migrate with a migration energy of 0.5 eV. The interstitial carbon can bind further to another substitutional carbon forming a substitutional carbon-interstitutional carbon pair with a binding energy of 1.0 eV. This model is used to understand the effect of high C concentration on the transient enhanced diffusion in Si.
Current theories on planetary formation establish that massive objects accrete gaseous envelopes, becoming gaseous planets if the accretion process proceeds before the accretion disc dissolution. One of the unsolved problems is that the planet formation is contextual to their quick migration towards the central star, due to the protoplanets-disc interaction, on a timescale lower by an order of magnitude than that of gas accretion onto the protoplanet. These arguments have been recently broached using N-body and/or Eulerian fluid-dynamics codes, mainly in 2D, or a mixing of them. In this work, 2D simulations with a SPH code are performed, to study the migration of one protoplanet. The goal is to scrutinise the protoplanet dragging as a function of planet's mass.
We have investigated the properties of nerve cell precursors in hydra by analyzing the differentiation and proliferation capacity of interstitial cells in the peduncle of Hydra oligactis, which is a region of active nerve cell differentiation. Our results indicate that about 50% of the interstitial cells in the peduncle can grow rapidly and also give rise to nematocyte precursors when transplanted into a gastric environment. If these cells were committed nerve cell precursors, one would not expect them to differentiate into nematocytes nor to proliferate apparently without limit. Therefore we conclude that cycling interstitial cells in peduncles are not intermediates in the nerve cell differentiation pathway but are stem cells. The remaining interstitial cells in the peduncle are ...
A silicon solar cell assembly comprising a large, thin silicon solar cell bonded to a metal mount for use when there exists a mismatch in the thermal expansivities of the device and the mount.
Experiments were designed to elucidate whether or not the irradiated bone marrow cells receive any stimulation for the self-replication and differentiation from normal 'stromal' cell colonies in the bone marrow cell culture in vitro. When irradiated or unirradiated bone marrow cells were overlaid on the normal adherent cell colonies, the proliferation of haemopoietic stem cells was supported, the degree of the stimulation depending on the starting cellular concentration. There was, however, no significant changes in the concentration of either CFUs or CFUc regardless of the dose of irradiation on the bone marrow cells overlaid. This was a great contrast to the dose-dependent decrease of CFUs or CFUc within the culture in which both the stem cells and stromal cells were ...
Ethane oxidation was studied in ethane-grown resting cells (mycelia) of an Acremonium sp. and in cell-free preparations of such mycelia. From resting cell experiments evidence was found for a pathway...Full Text Available
In most adult tissues there reside pools of stem and progenitor cells inside specialized microenvironments referred to as niches. The niche protects the stem cells from inappropriate expansion...Full Text Available
... Fuel Cell Technologies Equipment on Environmental Expert Find and compare a variety of fuel cell technologies equipment on the world's largest environmental industry portal. View ...
Purpose.There is a paucity of neuron replacement studies for retinal ganglion cells. Given the complex phenotype of these neurons, replacement of ganglion cells may be impossible....Full Text Available
Cell cultures were prepared from lung tumors occurring in beagles following exposure to inhaled plutonium. Morphologic and growth characteristics of two of these cell lines are described.
We report the isolation of adherent, clonogenic, fibroblast-like cells with osteogenic and adipogenic potential from the blood of four mammalian species. These cells phenotypically resemble but are...Full Text Available
Laser glazing, using a KrF excimer laser (> = 248 nm, >a = 22 ns), has been used to improve the corrosion resistance properties of crystallized Fe_4_0Ni_3_8Mo_4B_1_8 (Metglas 2826 MB) and the permanent magnet material Nd_1_5Fe_7_7B_8. The formation of an amorphous layer was confirmed by conversion-electron Mossbauer Spectroscopy (CEMS), and the thickness of the amorphous layer was determined from the attenuation of the x-rays diffracted from the underlying crystalline material. The variation with laser fluence of the amorphous layer thickness on the Metglas were measured. The corrosion properties of the original, crystalline and laser glazed Metglas were measured potentiodynamically in acid electrolyte. Similar voltametric characteristics were obtained for the laser glazed surface and original Metglas, both showing a lower current in the passive region than the crystalline material. Laser glazing of the Nd_1_5Fe_7_7B_8 also produced a ...
The effect of butylated hydroxytoluene (BHT) pretreatment (0.5% in the diet for 10 days) on the excretion, tissue distribution and DNA binding of orally administered (/sup 14/C)aflatoxin B1 (AFB1) was determined in male Fischer F344 rats. The amount of radioactivity excreted in the urine and feces by 24 hr was higher in BHT-treated rats than in controls. Treatment with BHT enhanced the excretion of water-soluble metabolites in the urine and in the large intestines plus feces at the earlier sampling times. The amount of radioactivity bound to hepatic nuclear DNA was six times less in the BHT-pretreated rats than in controls 6 hr after administration of the isotope. The half-lives of (/sup 14/C)DNA in the rat liver were 30 and 46 hr for control and BHT-pretreated rats, respectively. These results indicate that BHT pretreatment may protect the animal from the carcinogenic effects of AFB1 by enhancing the detoxification and excretion of the ...
Effects of cell concentrations on the survival and repopulation of haemopoietic stem cells after irradiation were studied in the long-term culture of mouse bone marrow cells in vitro. No difference was observed in the survival of the stem cells among cultures in which 0 - 10/sup 7/ cells were re-inoculated on the adherent cell colonies in the culture flask. Stem cells showed a significant proliferation within 1 week and the number of the stem cells exceeded the control in 3 weeks after irradiation in the cultures with less than 10/sup 6/ re-inoculated cells per flask. In contrast, there was a considerable delay in the onset of stem cell proliferation after irradiation in the culture with 10/sup 7/ cells per flask. Based on these results, a possibility that a ...
We wanted to evaluate the usefulness of a new type of a complex expandable nitinol stent that was designed to reduce the stent's propensity to migration during the treatment of malignant gastroduodenal obstructions. Two types of expandable nitinol stent were constructed by weaving a single thread of 0.2mm nitinol wire in a tubular configuration: an uncovered stent 18mm in diameter and a covered stent 16mm in diameter. Both ends of the covered stent were fabricated by coaxially inserting the covered stent into the tubular uncovered stent and then attaching the two stents together with using nylon monofilament. Under fluoroscopic guidance, the stent was placed in 29 consecutive patients (20 men and 9 women, mean age: 65 years) who were suffering with malignant gastric outlet obstruction (n=20), duodenal obstruction (n=6) or combined obstruction (n=3). Clinical improvement was assessed by comparing the food intake capacity before and after the procedure. The ...
In 1996, the National Marine Fisheries Service and the University of Washington completed the fourth year of a multi-year study to estimate survival of juvenile salmonids (Oncorhynchus spp.) passing through dams and reservoirs on the Snake River. Actively migrating smolts were collected near the head of Lower Granite Reservoir and at Lower Granite Dam, tagged with passive integrated transponder (PIT) tags, and released to continue their downstream migration. Individual smolts were subsequently detected at PIT-tag detection facilities at Lower Granite, Little Goose, Lower Monumental, McNary, John Day and Bonneville Dams. Survival estimates were calculated using the Single-Release (SR) and Paired-Release (PR) Models. Timing of releases of tagged hatchery steelhead (O. mykiss) from the head of Lower Granite Reservoir and yearling chinook salmon (O. tshawytscha) from Lower Granite Dam in 1996 spanned the major portion of their juvenile ...
Halide complexes of astatine cations At"+ and AtO"+ were prepared and their rate of migration was measured. The complexes are of the type AtX_2"- and AtOX_2"- (X = Cl"-, Br"-, I"-). The bromo complexes, AtBr_2"- and AtOBr_2"-, have a higher stability than the chloro complexes. The hydrolysis in weakly alkaline solution of AtX_2"- resulted At"-, and that of AtOX_2"- AtO_2"-. (author).
A new commercial cutting tool software package replaced an internally created legacy system. This report describes the issues that surfaced during the migration and installation of the commercial package and the solutions employed. The primary issues discussed are restructuring the data between two drastically different database schemas and the creation of individual component graphics.
Radionuclide techniques have commonly been used to assess ventriculovenous shunt function, cerebrospinal fluid dynamics, and for the diagnosis of cerebrospinal fluid leaks. All of these techniques were utilized in this unusual case of retrograde migration of a ventriculoatrial catheter into the neck, with cutaneous fistulization and CSF leak. (orig.).
Nine-component vertical seismic profiling has been conducted at the UE-25 UZ No. 16 borehole at Yucca Mountain, Nevada, in support of investigation of the hydrologic significance of fault and fracture systems. A large data set from multi-component sources and receivers allows state-of-the-art advances in processing using polarization filtering and reverse time migration, for enhanced interpretation of geologic features.
Nine-component vertical seismic profiling has been conducted at the UE-25 UZ No. 16 borehole at Yucca Mountain, Nevada, in support of investigation of the hydrologic significance of fault and fracture systems. A large data set from multi-component sources and receivers allows state-of-the-art advances in processing using polarization filtering and reverse time migration, for enhanced interpretation of geologic features.
... The moorland landscape looks especially colourful in late summer, while spring is the perfect time to come and see migrant birds like redstarts,...Valley This is a delightful oak woodland to walk through - especially in spring and early summer when lots of migrating birds come to breed ... Fowlmere Fowlmere's reedbeds and pools are fed by natural chalk springs, and a chalk stream runs through the reserve. Special birds ... There are common woodland birds in spring and turtle doves in spring and summer. Haweswater If you want to see a golden ...
... In spring, the marshes are filled with the atmospheric calls of lapwings and redshanks, all breeding on one of the UK's ...Butley river and Ore estuary, Boyton Marshes attracts breeding wading birds in spring and ducks, geese and swans in winter. It's also ... The moorland landscape looks especially colourful in late summer, while spring is the perfect time to come and see migrant birds like redstarts,...Valley This is a delightful oak woodland to walk through - especially in spring and early summer when lots of migrating birds come to breed ...
Given the possibility of highly pathogenic H5N1 avian influenza arriving in North America and monitoring programs that have been established to detect and track it, we review intercontinental movements...Full Text Available
Rotary screw traps, located at four sites in the Grande Ronde River basin, were used to characterize aspects of early life history exhibited by juvenile Onchorhychus mykiss during migration years 1995-99. The Lostine, Catherine Creek and upper Grande Ronde traps captured fish as they migrated out of spawning areas into valley rearing habitats. The Grande Ronde Valley trap captured fish as they left valley habitats downstream of Catherine Creek and upper Grande Ronde River rearing habitats. Dispersal downstream of spawning areas was most evident in fall and spring, but movement occurred during all seasons that the traps were fished. Seaward migration occurred primarily in spring when O. mykiss smolts left overwintering area located in both spawning area and valley habitats. Migration patterns exhibited by O. mykiss suggest that Grande Ronde Valley habitats are used for overwintering and should be ...
Computed tomographic findings in developmental brain anomalies are more easily classified when the system used is based on embryogenesis related to morphology. Analysis of computed tomographic findings in a series of 154 patients with brain anomalies (Chiari malformation not included) revealed that specific examples of abnormalities occurring in major stages of brain development may be recognized by computed tomography. This paper deals with a group of patients with abnormalities that reflect a disturbance in neuronal migration. (orig.).
A total of nine papers were presented at the course with the following titles: peat accumulation and coal basins; coal composition; coal quality; sedimentary environments of coal; generation, storage and migration of natural gas in coal bed reservoirs; geophysical log interpretation; the Ardley coal zone of central Alberta; stratigraphy and sedimentary environment of the Coalspur Formation; and the coal-bearing Luscar Group of western Alberta. All of these papers have been abstracted separately.
After a presentation of methods and tools for the basic and extensive characterization of polluted sites and the study of evolution and transfer of current organic pollutants in the ground, the example of the rehabilitation of an old Rhone-Poulenc site (at Chauny, France) polluted with metals and arsenic, is described: soil and aquifer diagnosis, risk analysis and determination of migration schemes
The object of this paper is to show how the profile of metal concentration in the soil near bone from archaeological sites can be used, along with the appropriate mathematical model, to extract transport parameters. These parameters can then be used to predict long-term migration rates of chemical species associated with the burial of hazardous wastes in similar environmental settings.
Defects are produced in zinc by 6.1 MeV #alpha#-particle irradiation at 4.2 K and the subsequent recovery between 4.2 and 22 K. No evidence is found for free migration of an interstitial in the temperature range investigated. The recovery spectra reveal a series of substages which are ascribed to recombination of close Frenkel pairs. (author).
The bosonic string on R"2"5xS"1 has a series of states turning tachyonic at radii implying T=IT_H. We employ the B picture to examine these thermal states in the one-loop free energy and find them in various combinations, factorizing towards rational points on the real line boundary of the fundamental domain B: (-1/2=# 0). These thermal tachyons are interpreted as signaling Hagedorn instabilities against the production of an l-highly-excited-identical-strings state, which gives a relation between the one-loop partition function and l-point functions. (orig.).
Several compounds were evaluated in nonhuman primates for their potential to induce neoplasms, especially hepatocellular carcinoma (HCC). The compounds can be classified into three groups: food contaminants, model rodent carcinogens, and nitrosamines. All three compounds in the food contaminants group, namely, aflatoxin B1, sterigmatocystin, and methylazoxymethanol acetate, induced HCC. None of the model rodent carcinogens tested consistently induced HCC in rhesus and cynomolgus monkeys. Three of four nitrosamines evaluated induced HCC in rhesus and cynomolgus monkeys. One nitrosamine, diethylnitrosamine, is a predictable and potent inducer of HCC and is useful for establishment of a nonhuman primate model for numerous oncologic studies.
In this note, we derive from Anstee's fractional $(g,f)$-factor theorem a similar characterization for the property of all fractional $(g,f)$-factors. Let $ab-1)^2+4b)$ and every pair of non-adjacent vertices has cardinality of the neighborhood union at least $bn/(a + b)$. This lower bounds are sharp.
Since 1994 the radon studies group at the Institut de Techniques Energetiques (INTE) of the Universitat Politecnica de Catalunya in Barcelona, Spain, has carried out a campaign of continuous measurements of the equilibrium factor (F) and the unattached fraction (f_p) of radon decay products at four sites which are representative of different environmental characteristics on the Mediterranean littoral of Catalonia, Spain. It has been established that these parameters vary widely, F(0.03--0.87) and f_p (0--0.72), from one site to another and with time, according to the characteristics on the site and climate. In spite of this variation, the F and f_p parameters are log-normally or normally distributed. The measurements of F and f_p show that f_p is negatively correlated to F by a log-power equation, Ln(1/f_p)=1.90[Ln(1/F)]"-"0"."6"8, which can be used in all the F range, instead of the commonly used power equation f_p=aF"b suggested by Stranden and Strand and other authors, which fits ...
The acid-base behavior of the ground and excited states of Pt(qdt){sub 2}{sup 2{minus}} and Pt(phen)(qdt), where qdt=quinoxaline-2,3-dithiolate and phen = 1,10-phenanthroline, has been studied. The pH-dependent changes in the charge-transfer absorption and emission spectra for both complexes are attributed to protonation of the quinoxalinedithiolate ligand at the imine nitrogen. For Pt(qdt){sub 2}{sup 2{minus}}, single protonation leads to a large red shift (2582 cm{sup {minus}1}) of the low-energy charge-transfer-to-dithiolate absorption band and the emergence of a new red-shifted emission feature at 728 nm. In solutions of pH below 6, a second protonation takes place at the other qdt ligand, yielding Pt-(Hqdt){sub 2}. This neutral complex has been isolated and characterized by {sup 1}H NMR spectroscopy and elemental analyses. The ground-state basicity constants of the two protonation steps have been determined from spectrophotometric titrations to be pK{sub ...
To evaluate the efficacy of newly designed covered and non-covered coated colorectal stents for colonic decompression. Twenty-six patients, (15 palliative cases and 11 preoperative) underwent treatment for the relief of colorectal obstruction using metallic stents positioned under fluoroscopic guidance. In 24 of the 26, primary colorectal carcinoma was diagnosed, and in the remaining two, recurrent colorectal carcinoma. Twenty-one patients were randomly selected to receive either a type A or type B stent; for the remaining five, type C was used. Type A, an uncovered nitinol wire stent, was lightly coated to ensure structural integrity. Type B (flare type) and C (shoulder type) stents were polyurethane covered and their diameter was 24 and 26mm, respectively. The rates of technical success, clinical success, and complications were analyzed using the chi-square test, and to analyse the mean period of patency, the Kaplan-Meier method was used. Thirty of 31 attempted placements in 26 ...
Terminal differentiation of many vascular cells involves cell wall changes. Cells first elongate their primary wall, then lay down a lignified secondary wall, which is often followed by digestion of...Full Text Available
For proper tissue morphogenesis, cell divisions and cell fate decisions must be tightly and coordinately regulated. One elegant way to accomplish this is to couple them with asymmetric cell divisions....Full Text Available
Totipotent stem cells have the potential to differentiate into every cell type. Renewal of totipotent stem cells in the germline and cellular differentiation during early embryogenesis rely upon posttranscriptional...Full Text Available
We have established a cartilaginous fish cell line [Squalus acanthias embryo cell line (SAE)], a mesenchymal stem cell line derived from the embryo of an elasmobranch, the spiny dogfish...Full Text Available
AIM: To isolate and identify the biological characteristics of human colon cancer stem cells (SW1116 cells) and further study their proteome.METHODS: SW1116 cells were isolated and cultured with...Full Text Available
Interleukin 2 (IL-2) and B-cell growth factors I and II (BCGF I and BCGF II) are lymphokines produced by T cells that play a major role in T- and B-cell cooperation. Peripheral blood lymphocytes from...Full Text Available
Normal cells, both in vivo and in vitro, become quiescent after serial cell proliferation. During this process, cells can develop immortality with genomic instability,...Full Text Available
BackgroundStem cell characteristics are an important feature of human cancer cells and play a major role in the therapy resistance of tumours. Strategies to target cancer stem cells...Full Text Available
Endothelial cells and mural cells (smooth muscle cells, pericytes, or fibroblasts) are known to communicate with one another. Their interactions not only serve to support fully functional blood...Full Text Available
BackgroundAs the resident stem cells of skeletal muscle, satellite cells are activated by extracellular cues associated with local damage. Once activated, satellite cells will re-enter...Full Text Available
Craniofacial injuries require a variety of different cell types to repopulate areas of bone, cartilage, tendon, and fat. Mesenchymal stem cells (MSCs) provide a multipotent cell source for tissue...Full Text Available
We describe the lethal, recessive accelerated-cell-death11 Arabidopsis mutant (acd11). Cell death in acd11 exhibits characteristics of animal apoptosis...Full Text Available
Somatic cell nuclear transfer or therapeutic cloning has provided great hope for stem cell-based therapies. However therapeutic cloning has been experiencing both ethical and technical difficulties....Full Text Available
Background:Stem cells can differentiate into multiple cell types, and therefore can be used for cellular therapies, including tissue repair. However, the participation of stem cells...Full Text Available
It has been postulated that thrombin binds to endothelial cells through, at least in part, cell surface glycosaminoglycans such as heparan sulfate, which could serve as antithrombin cofactor on the...Full Text Available
Hematopoietic stem cells replenish all the cells of the blood throughout the lifetime of an animal. Although thousands of stem cells reside in the bone marrow, only a few contribute to blood production...Full Text Available
In the growing chloronema cell suspension cultures of the moss Funaria hygrometrica Hedw., activities of several enzymes have been found to be cell-density-dependent. Cyclic nucleotide...Full Text Available
In preimplantation mouse development, the first cell lineages to be established are the trophectoderm (TE) and inner cell mass. TE possesses epithelial features, including apical-basal cell polarity...Full Text Available
...false Guidelines for Human Stem Cell Research Presidential Documents ...2009 Guidelines for Human Stem Cell Research Memorandum for the Heads...scientifically worthy human stem cell research, including human...
We have developed a cell-mediated mutagenesis assay in which cells with the appropriate markers for mutagenesis are co-cultivated with either lethally irradiated rodent embryonic cells that can metabolize carcinogenic hydrocarbons or with primary rat liver cells that can metabolize chemicals carcinogenic to the liver. During co-cultivation, the reactive metabolites of the procarcinogen appear to be transmitted to the mutable cells and induce mutations in them. Assays of this type make it possible to demonstrate a relationship between carcinogenic potency of the chemicals and their ability to induce mutations in mammalian cells. In addition, by simultaneously comparing the frequencies of transformation and mutation induced in normal diploid hamster cells by benzo(a)pyrene (BP) and one of its metabolites, it is possible to estimate the genetic ...
...Basic Information | Fuel Cells & Vehicles | US EPA This web page provides basic information on EPA's Fuel Cells & Vehicles web site ...including the chemical composition of fuel cell technology, how it works, descriptions of the various types of fuel cells , their availability and ... background,electrochemical,hydrogen,fuel cell,fuel cell vehicle,fuel reformer,performace,improved fuel economy,increased engine efficiency,lower emissions,zero emissions,availablity,fuel cell types,diagram,Proton ...Exchange Membrane,PEM Basic Information | Fuel Cells & Vehicles | US EPA background,electrochemical,hydrogen,fuel cell,fuel cell vehicle,fuel reformer,performace,improved fuel economy,...
Laser-assisted processing techniques for producing high-quality solar cell metallization patterns are investigated, developed, and characterized. The tasks comprising these investigations are outlined. A new batch of solar cells was processed using the laser decomposition of spun-on silver neodecanoate to metallize cells. Decomposition of silver neodecanoate was carried out at different laser powers on different cells on a given wafer to determine whether this would have any effect on cell performance. Solar cells which were written with laser powers of 5 to 8 watts, gave excellent results with cell efficiencies in the range of 14 to 16%.
... nent to the design and construction of metal-semiconductor solar cells, in that both the photovoltage and the efficiency of metal-semiconductor cells ...
... and pathogen transmission. Because the ultimate object of stem cell research is cell-based clinical therapy, hES cells should ... 4%) Supported by grants (SC12021 and SC11012) from Stem Cell Research...
Abstract Epstein-Barr virus (EBV), which infects not only B cells, but also T cells and natural killer (NK) cells, is associated with multiple lymphoid malignancies. Recently, the proteasome inhibitor bortezomib was reported to induce apoptosis of EBV-transformed B cells. We evaluated the killing effect of this proteasome inhibitor on EBV-associated T lymphoma cells and NK lymphoma cells. First, we found that bortezomib treatment decreased the viability of multiple T and NK cell lines. No significant difference was observed between EBV-positive and EBV-negative cell lines. The decreased viability in response to bortezomib treatment was abrogated by a pan-caspase inhibitor. The induction of apoptosis was confirmed by flow cytometric assessment of annexin V staining. Additionally, cleavage o...
In order to identify cells of maternal origin in CVS cultures, tissue from 1st trimester abortions were cultivated and the cultures stained in situ for X-chromatin. Convoluted cells and maternal fibroblasts were found to be positive. By chromosome analysis of cultures from 105 diagnostic placenta biopsies, obtained by the transabdominal route, metaphases of maternal origin were found in nine cases. In eight of these cases colonies of convoluted cells were observed. We conclude that convoluted cells are of maternal origin and are a reliable marker for maternal cell contamination in CVS cultures.
An assay system for the stem cell that colonizes the thymus and differentiates into T cells was developed, and by using this assay system the existence of two subpopulations of stem cells for T cell lineage was clarified. Part-body-shielded and 900-R-irradiated C57BL/6 (H-2b, Thy-1.2) recipient mice, which do not require the transfer of pluripotent stem cells for their survival, were transferred with cells from B10 X Thy-1.1 (H-2b, Thy-1.1) donor mice. The reconstitution of the recipient's thymus lymphocytes was accomplished by stem cells in the donor cells and those spared in the shielded portion of the recipient that competitively colonize the thymus. Thus, the stem cell activity of donor cells can be evaluated by determining the proportion of donor-type (Thy-1.1+) ...
Understanding prostate stem cells may provide insight into the origin of prostate cancer. Primary cells have been cultured from human prostate tissue but they usually survive only 15-20 population doublings before undergoing senescence. We report here that RC-170N/h/clone 7 cells, a clonal cell line from hTERT-immortalized primary non-malignant tissue-derived human prostate epithelial cell line (RC170N/h), retain multipotent stem cell properties. The RC-170N/h/clone 7 cells expressed a human embryonic stem cell marker, Oct-4, and potential prostate epithelial stem cell markers, CD133, integrin #alpha#2#beta#1"h"i and CD44. The RC-170N/h/clone 7 cells proliferated in KGM and Dulbecco's Modified Eagle Medium with 10% fetal bovine serum and 5 #mu#g/ml insulin (DMEM + 10% FBS + Ins.) ...
Nuclear fuel cycle activities of the former Soviet Union (FSU) have resulted in massive contamination of the environment in western Siberia. We are developing three-dimensional numerical models of the hydrogeology and potential contaminant migration in the West Siberian Basin. Our long-term goal at Pacific Northwest Laboratory is to help determine future environmental and human impacts given the releases that have occurred to date and the current waste management practices. In FY 1993, our objectives were to (1) refine and implement the hydrogeologic conceptual models of the regional hydrogeology of western Siberia developed in FY 1992 and develop the detailed, spatially registered digital geologic and hydrologic databases to test them, (2) calibrate the computer implementation of the conceptual models developed in FY 1992, and (3) develop general geologic and hydrologic information and preliminary hydrogeologic conceptual models relevant to the more detailed ...
Lab scale mulch biofilm barriers were constructed and tested to evaluate their performance for preventing the migration of aqueous and surfactant solubilized PAHs. The spatial distribution of viable PAH degrader populations and resultant biofilm formation were also monitored to evaluate the performance of the biobarrier and the prolonged surfactant effect on the PAH degrading microorganism consortia in the biobarrier. Sorption and biodegradation of PAHs resulted in stable operation of the system for dissolved phenanthrene and pyrene during 150 days of experimentation. The nonionic surfactant could increase the solubility of phenanthrene and pyrene significantly. However, the biobarrier itself couldn't totally prevent the migration of micellar solubilized phenanthrene and pyrene. The presence of surfactant and the resultant highly increased phenanthrene or pyrene concentration didn't appear to cause toxic effects on the attached biofilm in the ...
We present a new computation of the linear tidal interaction of a protoplanetary core with a thin gaseous disc in which it is fully embedded. For the first time a discussion of the orbital evolution of cores with eccentricity (e) significantly larger than the gas-disc scale height to radius ratio (H/r) is given. We find that the direction of orbital migration reverses for e>1.1H/r. This occurs as a result of the orbital crossing of resonances in the disc that do not overlap the orbit when the eccentricity is very small. Simple expressions giving approximate fits to the eccentricity damping rate and the orbital migration rate are presented. We go on to calculate the rate of increase of the mean eccentricity for a system of protoplanetary cores due to dynamical relaxation. By equating the eccentricity damping time-scale with the dynamical relaxation time-scale we deduce that an equilibrium between eccentricity damping and excitation through ...
The Oklo natural fossil fission reactors in Gabon, Equatorial Africa, have been studied as a natural analogue for spent nuclear fuel in a geological environment. For these studies, it is important to know what has happened to these reactors since they formed. This review is focussed on existing geological and geochronological information concerning the Oklo reactors and the surrounding ore. A sequence of geological and geochemical events in the Oklo area, as described in the literature, is given. The data and the studies behind this established geochronology are discussed and evaluated. Of the regional geology, special attention is given to the dating of the Francevillian sediments, and the intrusion of a dolerite dyke swarm. The processes that led to the mineralisation at Oklo, the subsequent formation of the nuclear reactors and later migration of fission products are described. Further discussion concerns the studies of the dolerite dyke swarm, since this ...
In this study, dissimilar welds between HP heat-resistant steel and Incoloy 800 were made with four different filler materials including: 309 stainless steel and nickel-based Inconel 82, 182 and 617. The microstructure of the base metals, weld metals and their interfaces were characterized by utilizing optical and scanning electron microscopy. Grain boundaries migration in the weld metals was studied. It was found that the migration of grain boundaries in the Inconel 82 weld metal was very extensive. Precipitates of TiC and M_2_3C_6 (M = Cr and Mo) in the Inconel 617 weld metal are identified. The necessary conditions for the formation of cracks close to the fusion line of the 309-HP joints are described. Furthermore unmixed zone near the fusion line between HP steel base metal and Inconel 82 weld metal is discussed. An epitaxial growth is characterized at the fusion line of the 309-Alloy 800 and Inconel 617-Alloy 800 joints.
Recent organic geochemical studies differ radically in their interpretation of the origin of the Gulf coast oils. However all studies since (and including) Thompson, et al. 1989, emphasize the considerable geographic variation in genetic oil types and are in generalized agreement as to the genetic oil types present and their spatial and stratigraphic relationships. In particular it is accepted that the Gulf rim (both north and south) is encircled by a ring of Mesozoic carbonate-sourced oils and that there is also at least one major deep water trend of carbonate-sourced oils in the northern Gulf. It is also generally agreed that many of the Gulf rim oils are of Oxfordian-Kimmeridgian age, though some, like the Sunniland oils of Florida, are of lower Cretaceous origin. Major disagreement still occurs over the sources of the Louisiana offshore oils and onshore Wilcox reservoired oils. One {open_quotes}school of thought{close_quotes} assigns all these oils to Mesozoic sources. The other ...
The origin of natural gas in the Japanese oil and gas fields are geochemically studied. Samples are taken from structural natural gas, surface gas seepage, water-dissolved natural gas and coal-field gas of the Japan Sea coast area. The origins of primary hydrocarbons are classified into bacteria gas and thermogenic gas, the latter being subclassified into gas in oil production zone with the per million deviation of the carbon isotope (/sup 13/C/sup 1/) of methane less than -35 and those gases with maturity higher than this. Surface gas seepage is subjected to migration and bacterial oxidation. Coal gas is similar to oil gas. The CO/sub 2/ concentration is 0 - 2% and /sup 13/CO/sub 2/ deviations from -30 - +30. The origin can be barely estimated from the isotopic composition because of the wide secondary change in the composition. The origin and migration of gas from the gas field of northern Niigata are not similar to those in the southern ...
Grout has been evaluated as a means of containing low-level radioactive waste for long-term disposal. Concerns about hydrogen and reactive gas generation in the Hanford Site grout disposal facility lead to the development of the G3 model, which has predicted buildup of radiolytically formed gases in the grout region and their migration to air-filled regions. The G3 model is a one-dimensional code that couples models of gas diffusion with two-phase gas and liquid flow. It was coupled to a compartment diffusion model and these models predicted the concentrations of hydrogen I nitrous oxide, and other gases in air-filled regions of the grout disposal facility. The results have served as the technical basis for safety studies. A unique finding of the G3 model was that a liquid return, or expulsion of unbound liquid from the grout region, could occur. This liquid return is driven by displacement caused by gas bubbles that form within the grout`s microstructure. Liquid ...
Enhanced superlattice disordering in nonstoichiometric AlAs/GaAs quantum wells exhibits weak temperature dependence because of the decay of the supersaturated concentration of group-III vacancies. We present a formalism for transient enhanced diffusion in nonstoichiometric materials with which we can extract migration enthalpies {ital H}{sub {ital m}} by assuming that the vacancy decay is thermally activated with an enthalpy {ital H}{sub {ital a}}. By analyzing the electroabsorption from the quantum-confined Stark effect for a set of isochronal and isothermal anneals, we extract a migration enthalpy {ital H}{sub {ital m}}=(1.8{plus_minus}0.2) eV for group-III vacancies, as well as an activation enthalpy {ital H}{sub {ital a}}=(0.7{plus_minus}0.2) eV for vacancy annihilation. {copyright} {ital 1996 American Institute of Physics.}
The mobility of oxidized astatine in solutions H(Na)ClO/sub 4/ (..mu..=0.4M)-1.10/sup -4/M K/sub 2/Cr/sub 2/O/sub 7/ has been measured at 25 degC in the interval 0.63<=pH<=1.68. Under these conditions astatine migrates to the cathode only. The speeds of the migration depends upon the concentration of hydrogen ions in solutions are: pH 1.68 Usub(c)=1.17.10/sup -4/ cm/sup 2/ V/sup -1/ s/sup -1/; pH 0.63 Usub(c)=2.67.10/sup -4/ cm/sup 2/ V/sup -1/ s/sup -1/. The effect agrees with the opinion that the singly charged cation of astatine formed in acidic solutions is a strong aquacomplex ((H/sub 2/O)sub(x)At)/sup +/ (x=1-2) (protonated hypoastatic acid). Deprotonation constant of this cation is Ksub(dp)=0.032+-0.005. Specific properties of the astatine cation are given. They can be explained, probably, through the peculiarities of its structure. 14 refs.
The mobility of oxidized astatine in solutions H(Na)ClO_4 (#mu#=0.4M)-1.10"-"4M K_2Cr_2O_7 has been measured at 25 degC in the interval 0.63<=pH<=1.68. Under these conditions astatine migrates to the cathode only. The speeds of the migration depends upon the concentration of hydrogen ions in solutions are: pH 1.68 Usub(c)=1.17.10"-"4 cm"2 V"-"1 s"-"1; pH 0.63 Usub(c)=2.67.10"-"4 cm"2 V"-"1 s"-"1. The effect agrees with the opinion that the singly charged cation of astatine formed in acidic solutions is a strong aquacomplex [(H_2O)sub(x)At]"+ (x=1-2) (protonated hypoastatic acid). Deprotonation constant of this cation is Ksub(dp)=0.032+-0.005. Specific properties of the astatine cation are given. They can be explained, probably, through the peculiarities of its structure. (author).
A mathematical model of 137Cs migration in forest ecosystem is presented, which describes the behaviour of this radionuclide in the forest litter-soil system, trees, understory and forest animals. The model's parameters for different types of forest ecosystems are estimated and model's adequacy is tested through the use of independent experimental data. The sensitivity of the model's output variables is analyzed to variations in the most significant parameters. The differences in the seasonal and mean annual dynamics of 137Cs concentration in muscles of roe deers and mooses are shown to be defined by specific features of the diets of these animals and variations in 137Cs content in the main diet components. PMID:11402557
This is a review of recently published literature on surgery in tropical Africa. It presents the current state of surgical need and surgical practice on the continent. We discuss the enormous burden of surgical pathology (as far as it is known) and the access to and acceptability of surgery. We also describe the available facilities in terms of equipment and manpower. The study looked at the effects of the human immunodeficiency virus, the role of traditional healers, anesthesia, and the economics of surgery. Medical training and research are discussed, as are medical migration out of Africa and the concept of task shifting, where surgical procedures are performed by others when surgeons are not available. It closes with recommendations for involvement and action in this area of great glob...
This study was initiated to provide empirical data and analyses on the dam passage timing, travel rate, survival, and life history variation of fall Chinook salmon that are produced in the Clearwater River. The area of interest for this study focuses on the lower four miles of the Clearwater River and its confluence with the Snake River because this is an area where many fish delay their seaward migration. The goal of the project is to increase our understanding of the environmental and biological factors that affect juvenile life history of fall Chinook salmon in the Clearwater River. The following summaries are provided for each of the individual chapters in this report.
The relationship between short term relative sea-level oscillations and the reef, off-reef deposits geometry of an Upper Devonian third order sequence highstand of the Nisku Formation in west central Alberta was studied through the analysis of high resolution sequence stratigraphy. Hydrocarbon generation was reconstructed by total organic carbon values and migration patterns that were dependent on the geometry of three fourth order sequences. This stratigraphic reconstruction provided the key to recent hydrocarbon discoveries such as in the Brazeau southern reef margin.
Transient, greatly enhanced diffusion has been observed on annealing solid-phase-epitaxial (SPE) grown Si-Sb alloys. This is shown to be due to a high concentration of interstitials being trapped during SPE regrowth. The migration enthalpy, for diffusion of Sb by an interstitialcy mechanism was measured as 1.8 +/- 0.2 eV. The interstitials eventually condensed into loops, marking the end of the transient. In a SPE grown Si-Bi alloy a similar transient enhanced diffusion was observed, with an activation energy of 2.0 +/- 0.2 eV, but no loops formed. 8 figures, 7 references.
Transient, greatly enhanced diffusion has been observed on annealing solid-phase-epitaxial (SPE) grown Si-Sb alloys. This is shown to be due to a high concentration of interstitials being trapped during SPE regrowth. The migration enthalpy, for diffusion of Sb by an interstitialcy mechanism was measured as 1.8 +/- 0.2 eV. The interstitials eventually condensed into loops, marking the end of the transient. In a SPE grown Si-Bi alloy a similar transient enhanced diffusion was observed, with an activation energy of 2.0 +/- 0.2 eV, but no loops formed. 8 figures, 7 references.
This invention refers to the organic geochemistry and can be used in prospecting for oil and gas. The method includes taking samples of rocks, extracting from them the chloroform bitumoid and its thermal processing. In order to improve the accuracy, the equal quantities of bitumoid taken are exposed to gradual thermal treatment to temperatures exceeding the thresholds of thermal stability of sulfur-containing compounds, in each temperature interval, the content of hydrogen sulfide released in this case is revealed, and by its drastic increase at temperatures corresponding to the temperatures of the productive part of the section, a conclusion is drawn about the epigenetic nature of the bitumoid. The method makes it possible to improve the resolution of the bituminological prospecting for oil and gas.
Epitaxial thin films of nanotwinned face-centered cubic metals such as Cu possess an unprecedented combination of high hardness and high electrical conductivity due to the unique structure of nanometer-spaced coherent twin boundaries. Recent studies of in-situ nanoindentation in a transmission electron microscope have provided new insights on the deformation behavior of nanotwins that are reviewed here. In particular, two unit processes are highlighted: first, stress-induced migration of ?3 {112} incoherent twin boundary that leads to de-twinning of nanotwins; second, twinning dislocation can be multiplied at ?3 {111} coherent twin boundary.
The Uinta Basin is an important hydrocarbon producing area, with extensive resources of hydrocarbon, bitumen, and fossil fuels. Gilsonite, tar sands, oil shale and coal are found in abundance with the cretaceous and Tertiary sedimentary rocks. The 25 papers include discussion on: leasing; thermal maturity of rocks and hydrocarbon deposits; influence of source rock type, thermal maturity and migration on composition and distribution of the natural gas; drilling; geology; structural evolution of gilsonite dykes; reclamation of coal mines; oil shale resources; and uranium mining.
We have investigated the formation and coarsening of Ga droplets on focused-ion-beam (FIB) irradiated GaAs surfaces. To separately examine formation and coarsening, Ga droplets were fabricated by Ga"+ FIB irradiation of GaAs substrates with and without pre-patterned holes. We determined the droplet growth rate and size distribution as a function of FIB energy following irradiation. The data suggest a droplet formation mechanism that involves Ga precipitation from a Ga-rich layer, followed by droplet coarsening via a combination of diffusion and Ostwald ripening or coalescence via droplet migration (dynamic coalescence).
Phytoplankton community was investigated in the cage culture area of Daya Bay during a diurnal cycle. Two rainfalls occurred during the course of the experiment and decreased the surface seawater salinity in the aquaculture area. A total of 38 species were identified, of which the dominant species included Pseudo-nitzschia spp. and Skeletonema costatum. Water stratification obstructed the vertical migration of dinoflagellates. Statistical analysis indicated that Synechococcus showed negative relationship with silicate and ammonia, which indicated that Synechococcus adapted to grow at oligotrophic environment. Phytoplankton community structure implied the risk of Pseudo-nitzschia spp. blooms in the aquaculture area of Daya Bay.
In the presented case study CRS processing was able to improve the overall data quality of the processed lines in terms of signal-to-noise ratio and imaging. The complex geology is causing serious problems in conventional NMO/DMO processing that were solved by CRS processing. Even a depth processing with velocities calculated from CRS attributes gives good results similar to those from PreSDM in terms of the velocity field. Data quality of poststack depth migrated CRS stacks is even better than the image from PreSDM. (orig.)
A synthesis of scientific knowledge about petroleum biodegradation linked to uranium mineralisation is firstly done. Then the genesis of Huemul Uranium ore deposit (Malargue Town, Mendoza Province) is discussed, where Uranium ore is linked only with one type of asphaltite (there are three other types) from an oil field close by. This asphaltite type would be an efficient natural geological barrier for Uranium migration and it could be linked to a particular kind of biodegradation. The authors think that the International Wonuc Conference would be a good opportunity to discuss a way for future investigations. (author)
The herbicide atrazine is a known immunotoxicant and an inhibitor of human natural killer (NK) cell lytic function. The precise changes in NK cell lytic function following atrazine exposure have not been fully elucidated. The current study identifies the point at which atrazine exerts its affect on the stepwise process of human NK cell-mediated lyses of the K562 target cell line. Using intracellular staining of human peripheral blood lymphocytes, it was determined that a 24-h in vitro exposure to atrazine did not decrease the level of NK cell lytic proteins granzyme A, granzyme B or perforin. Thus, it was hypothesized that atrazine exposure was inhibiting the ability of the NK cells to bind to the target cell and subsequently inhibit the release of lytic protein from the NK cell. To test t...
Introduction: Haploidentical transplantation, with extensive T cell depletion to prevent GvHD, is associated with a high incidence of infection-related deaths. The key challenge is to improve immune recovery with allogeneic donor T cells without triggering GvHD. As T regulatory cells (Tregs) controlled GvHD in pre-clinical studies, the present study evaluated the impact of an infusion of donor CD4/CD25 + Tregs, followed by an inoculum of donor mature T cells (Tcons) and positively immunoselected CD34 + cells in the setting of haploidentical stem cell transplantation. Patients and methods: Twenty-eight patients were enrolled in this study (22 AML; 5 ALL; 1 NHL). All received immunoselected Tregs (CliniMACS, Miltenyi Biotec) followed by positively immunoselected CD34 + cells together with Tc...
The presence of a high number of activated T cells in the bloodstream and spontaneous proliferation of peripheral blood mononuclear cells in vitro are striking characteristics of human T-cell leukemia...Full Text Available
The article is the second part of a review dealing with latest developments in the area of solar cell technologies and application. Physical principles, design and efficiency as well as advantages and disadvantages of GaAs- and CdS-solar cells are described. Power generation solar cell systems with voltage converters, combined solar cell/solar collector systems and thermoelectric solar systems are presented in the second part of the article.
The herbicide atrazine is a known immunotoxicant and an inhibitor of human natural killer (NK) cell lytic function. The precise changes in NK cell lytic function following atrazine exposure have not been fully elucidated. The current study identifies the point at which atrazine exerts its affect on the stepwise process of human NK cell-mediated lyses of the K562 target cell line. Using intracellular staining of human peripheral blood lymphocytes, it was determined that a 24-h in vitro exposure to atrazine did not decrease the level of NK cell lytic proteins granzyme A, granzyme B or perforin. Thus, it was hypothesized that atrazine exposure was inhibiting the ability of the NK cells to bind to the target cell and subsequently inhibit the release of lytic protein from the NK cell. To test this hypothesis, flow cytometry ...
Cell therapy is a promising novel option for treatment of cardiovascular disease. Because the role of bone marrow-derived circulating progenitor cells (BM-CPCs) after cell therapy is less clear, we...Full Text Available
PCD (programmed cell death) in plants presents important morphological and biochemical differences compared with apoptosis in animal cells. This raises the question of whether PCD arose independently...Full Text Available
Although human T-cell lymphotropic virus type I (HTLV-I) is the etiologic agent of adult T-cell leukemia/lymphoma (ATL), the role of viral gene expression in the progression to and maintenance of the...Full Text Available
Bovine leukemia virus (BLV), a retrovirus related to human T-cell leukemia virus types 1 and 2, can induce persistent nonneoplastic expansion of the CD5+ B-cell population, termed...Full Text Available
Solid Oxide Fuel Cell (SOFC) is expected as a new power generation source. The development of SOFC is being conducted by CRIEPI, and so far several reports of the reults were presented. This report examines materials of SOFC. For the purpose, cells were made using some of typical materials and manufacturing processes, and cell performance tests were carried out.
The passive continental margin in the northern South China Sea is a weakly active area. It has been found to be favorable for large gas field development and also to be profitable for gas hydrate. The active faults, diapir structure, slump deposits, faults break of slopes, gas chimneys and sandstone of submarine fan, control the concentration of gas hydrate. Gas chimneys are widely distributed in the northern South China Sea. They supply the pathway for migration of deeper gas to gas hydrate stability zones especially in the basin of tectonic inactive zone. This paper discussed the geological structures of gas hydrate occurrence in gas fields and presented a detailed analysis of gas chimneys within the northern slope of the South China Sea. The paper described the geological setting of the Qiongdongnan Basin and provided information on the data description and processing. Two multichannel seismic (MCS) reflection profiles were used for the study. In order to ...
The aim of the thesis is to validate concepts used in hydrocarbon generation and migration models; the model considered is the Temispack model developed by IFP, and the validation is based on the investigation of the thermal and hydraulic evolution in various sedimentary basins. It is shown that, in general, the thermal history of sediments is influenced by external processes (sedimentation rates, lithology, climate changes, regional-scale groundwater circulations) which frequently overprint internal processes (variations of crustal/mantle heat flow). It is found that external processes can frequently explain past thermal events that were erroneously attributed to internal causes (tectonic-thermal events). The origin of over-pressures in young basins with high sedimentation rates is shown to be generally related to compaction disequilibrium. Shale permeability values calibrated against overpressure profiles are consistent with experimental constraints. Compaction ...
This paper reports about in-situ corrosion studies on selected materials for long-term resistant high-level waste (HLW) packagings acting as a barrier in a rock salt repository. The materials (Ti 99.8-Pd, Hastelloy C4 and five iron-base materials) were investigated in heated boreholes in the Asse salt mine under simulated HLW disposal conditions prevailing in normal operation of repository and in certain accident scenarios. The experiments under normal operating conditions were performed at temperatures of 120 deg. C to 210 deg. C (vertical temperature profile in the boreholes) without and with gamma irradiation (3#centre dot#10"2 Gy/h, Co-60 source) within the framework of the German/US Brine Migration Test. In these experiments only small amounts of migrated brine inclusions (NaCl-rich) from the rock salt were present as corrosion medium. In the experiments carried out under simulated accident conditions with intrusion of larger amounts of ...
Coiling or infusion of embolic materials into a wide necked aneurysm can be performed with stenting. The purpose of our study is to assess the technical feasibility of aneurysm treatment with glue embolization after stenting. We used four Wallstents for surgically repairing eight canine carotid aneurysms. After confirmation of the aneurysms on the angiogram, we introduced a 6-7 F guiding catheter in order to deploy the stents. After stenting, we passed a microcatheter into the aneurysm lumen through the stent mesh. 28% glue was slowly injected until the glue cast completely filled the lumen. We evaluated the passage of a microcatheter through the stent meshwork, formation of the glue cast and the stents' ability to protection for any leakage of glue. The follow-up angiogram was obtained for two dogs, one to three times until 8 weeks, and then we sacrificed the dogs and performed pathologic examinations. Stenting was successful in all cases except one in which the vessel was occluded ...
A general space- and energy-dependent formalism is developed in order to analyze zero-power neutron noise experiments in fast reactor systems. A generalized dispersion equation is combined with theoretical expressions for the experimentally measured power spectral density and variance-to-mean ratio which makes it possible to express these quantities in terms of a double moment of the Laplace and Fourier transformed Green's function of a slowing-down operator rather than those of the full Boltzmann operator. Several spatial approximations are analyzed in the context of the general formalism. In each case, the power spectral density and variance-to-mean ratio are written in terms of an appropriate fast reactor dispersion law for the medium which can be calculated from the solution to a simple slowing-down equation. The resultant expression for the power spectral density are analyzed for various combinations of neutron migration descriptions, slowing-down ...
During 1991 and 1992, we studied 92 wetlands, including open water (ponds) and emergent communities, created as a result of Wyoming Abandoned Mine Lands` (AML) reclamation efforts in northeast Wyoming. Through these activities, over 300 wetlands were filled, reclaimed, created, or otherwise modified. For mitigation purposes wetlands to be filled or modified were first evaluated using a Wetland Habitat Value (WHV) Model. Using the model, wetland losses were mitigated by increasing the WHV of some wetlands or by creating new wetlands elsewhere. We evaluated model performance in offsetting wetland loss and how well the model predicted waterfowl use. We also compared post-reclamation wetland sizes to those predicted by engineering plans and submitted for Section 404 permit approval. In our study, predicted WHVs were overestimated at 100% of the wetlands for which pre-reclamation WHVs were available (n8). The most commonly overestimated variables were size, fraction of emergent cover, ...
The author presents and analyzes three approaches to calculating explicit two-dimensional (2D) depth-extrapolation filters for all propagation modes (P, SV, and SH) in transversely isotropic media with vertical and tilted axis of symmetry. These extrapolation filters are used to do 2D poststack depth migration, and also, just as for isotropic media, these 2D filters are used in the McClellan transformation to do poststack 3D depth migration. Furthermore, the same explicit filters can also be used to do depth-extrapolation of prestack data. The explicit filters are derived by generalizations of three different approaches: the modified Taylor series, least-squares, and minimax methods initially developed for isotropic media. The examples here show that the least-squares and minimax methods produce filters with accurate extrapolation (measured in the ability to position steep reflectors) for a wider range of propagation angles than that obtained ...
High concentrations of Cs-137 were detected in the muscles of Walleye Pollack (Theragra chalcogramm) collected from Kitamiyamato banks (sampling on 25 Jul. 2000), Kamui area (16 Oct. 2000) and Niigata coasts (31 Jan. 2001). The concentrations were 0.35 #+-# 0.01, 0.41 #+-# 0.01, and 0.63 #+-# 0.02 Bq/kg-wet, respectively. The average concentration in our past investigations was about 0.25 #+-# 0.01 Bq/kg-wet. Samples from other areas, the coat of Kushiro (8 May 2001), North Tishima (13 Nov. 2000) and the Sea of Okhotsk (6 May 2001), had the average concentrations. There were no such high concentrations of Cs-137 in other fish species collected from Kitamiyamato banks, Kamui area, and Niigata coasts. Fish samples with high concentrations all make the migration in the north of Japan sea. These results would indicated that samples took in Cs-137 elements from sea-water or foods on the migration route. Cs-137 concentrations in muscles of walleye ...
Abstract Strains of Pseudomonas syringae are effective in controlling postharvest diseases of citrus fruits, and antagonistic activity has been correlated with in vitro production of lipodepsipeptides. Additionally, biocontrol agents can induce a range of defence mechanisms of resistance in citrus tissue that result in a broad spectrum of metabolic modifications, such as systemic acquired resistance, induced systemic resistance and production of reactive oxygen species. The aim of this study was to evaluate the expression of syringomycin (syrB1) and syringopeptin (sypA) synthetase genes from P.syringae pv. syringae biocontrol strains in vitro on different culture media and in vivo on citrus fruits (Citrus sinensis cv. Tarocco) during the interaction with Penicillium digitatum by quantitati...
The structural stability, electronic and elastic properties of ScN under high pressure were investigated by using full-potential linearized augmented plane-wave (FP-LAPW) method. Our calculations indicate that there exists a pressure-induced structural phase transformation from the ambient rock-salt (B1) phase to CsCl-type (B2) phase above 335 GPa. The origin of moderate high bulk modulus, mechanical and high melting point was analyzed by electronic properties. The variations of elastic constants (C_i_j) with volume and pressure have been investigated. Moreover, the volume dependencies of Debye temperature, the longitudinal and transverse elastic wave velocities have been presented.
A backward wave oscillator (BWO) filled with a strongly magnetized plasma supports TM and Trivel-piece-Gould (TG) modes. At large amplitudes these modes may act as wigglers for generating millimeter waves via free electron laser instability. The nonlinear coupling between the wiggler, the beam space charge mode, and the high frequency free electron laser wave is dominated by parallel motions. In the Raman regime the growth rate of instability goes as #approx##omega#_p_b"1"/"2/#gamma#_o"9"/"4, where #omega#_p_b is the beam plasma frequency and #gamma#_o is the relativistic gamma factor.
The PVSCAN is an instrument designed to characterize silicon solar cell materials and devices. It performs a host of measurements that yield spatial maps of dislocation density, grain distribution, reflectance, and photoresponses from near-junction and the bulk of a solar cell.
The penetration by moxifloxacin of human neutrophils (polymorphonuclear leukocytes [PMN]) and tissue-cultured epithelial cells (McCoy cells) was evaluated by a fluorometric assay. At...Full Text Available
There is ample evidence suggesting that superantigens may act as a triggering factor in the pathogenesis of rheumatoid arthritis (RA). We investigated whether superantigen could activate T cells in...Full Text Available
SUMMARYThe cytolytic activity of natural killer (NK) cells is regulated by inhibitory receptors that detect the absence of self molecules on target cells. Structural studies of...Full Text Available
The proliferation of stem cell research, conflated with its ethical and moral implications, has led governments to attempt regulation of both the science and funding of stem cells. Due to a diversity...Full Text Available
Embryonic stem cells have the ability to develop into virtually any cell in the body, and may have the potential to treat medical conditions such as diabetes and Parkinsons disease. On August 9, 2001, President Bush announced that for the first time feder...
Background: In North America and Europe, 80% of invasive skin cancers are basal cell carcinoma while 20% are squamous cell carcinoma (SCC). In contrast, African studies reveal a preponderance...Full Text Available
BackgroundSpindle cell carcinoma (SpCC) is a rare microscopic type of cancer of the mouth and oropharynx. Although SpCC is thought to arise from squamous cell carcinoma (SCC), it...Full Text Available
This paper describes a radiation shield verification survey of a large hot cell at the Fast Flux Test Facility (FFTF). The following aspects of the shield test are discussed: description of the FFTF; description of the hot cell; the test procedures; radiation protection, and the test results.
... from Dr. Austin Smith of the Institute for Stem Cell Research, University of Edinburgh) was modified from the CGR8 ... to thank Dr. Austin Smith, the Institute for Stem Cell Research, University of Edinbu...
Human myeloid-lineage cells are refractory to HIV-1 infection. The Vpx proteins from HIV-2 and sooty mangabey SIV render these cells permissive to HIV-1 infection through proteasomal degradation of...Full Text Available
Most genetic changes that promote tumorigenesis involve dysregulation of G1 cell cycle progression. A key regulatory site in G1 is a growth factor–dependent restriction point (R) where cells...Full Text Available
Target of rapamycin (TOR) kinases control cell growth through two functionally distinct multiprotein complexes. TOR complex 1 (TORC1) controls temporal cell growth and is sensitive to rapamycin, whereas...Full Text Available
... based, disease treatment remains promising, the emphasis for stem cell research from the biomedical research community is clear, and ... diagnosis as a novel source of embryos for stem cell research. Repr...
The cells of the endosperm of castor bean seeds (Ricinus communis) undergo programmed cell death during germination, after their oil and protein reserves have been mobilized. Nuclear...Full Text Available
Placental and placental-like alkaline phosphatase (PLAP) levels in the culture media of 87 cell lines of neoplastic and 'normal' origin were measured by a conventional immunosorbent enzymatic assay...Full Text Available
The rate and capacity for chloroform (CF) and trichloroethylene (TCE) transformation by a mixed methanotrophic culture of resting cells (no exogenous energy source) and formate-fed cells were measured....Full Text Available
A new method is described for continuously measuring cell turgor pressure (P), hydraulic conductivity (Lp), and volumetric elastic modulus (ε) in higher plant cells, using a pressure...Full Text Available
PURPOSE: To determine the frequency of ophthalmic abnormalities in patients with cutaneous T-cell lymphoma (mycosis fungoides and Sézary syndrome) and T-cell lymphoma involving the skin and...Full Text Available
The primary aim of this study was to develop a model system that uses epidermal cells (keratinocytes and accessory pigmented cells) cultured on a reconstituted basement membrane biomatrix for use in...Full Text Available
Amorphous silicon solar cells have been shown to have efficiencies which degrade as a result of long exposure to light. Annealing such cells in air at a temperature of about 200.degree. C. for at least 30 minutes restores their efficiency.
Special red cells were found on the adaxial surface of tertiary pulvini of Mimosa pudica and experiments performed to determine the origin and function of these cells. Using anatomical...Full Text Available
Red cell transfusions are associated with the development of acute lung injury in the critically ill. Recent evidence suggests that storage induced alterations of the red blood cell (RBC) collectively...Full Text Available
Adhesion of Spirogyra (tentatively, Spirogyra fluviatilis) cells to glass is described. The cells of an algal filament can adhere to a substrate only when they are...Full Text Available
Many patients who undergo hematopoietic cell transplantation (HCT) present with anemia and have received red blood cell transfusions before HCT. As a result, iron overload is frequent and appears...Full Text Available
Understanding the interactions between herpesviruses and their host cells and also the interactions between neoplastically transformed cells and the host immune system is fundamental to understanding...Full Text Available
Stem cells of the human prostate gland have not yet been identified utilizing a structural biomarker. We have discovered a new prostatic epithelial cell phenotype-expressing cytokeratin 6a (Ck6a+...Full Text Available
BackgroundStem cells divide to reproduce themselves and produce differentiated progeny. A fundamental problem in human biology has been the inability to measure how often stem cells...Full Text Available
... is known as "reproductive cloning." The Link to Stem Cell Research Stem cell research and research cloning are closely linked. Scientists in ... to arrive at a position on cloning and stem cell research. Many nations, including the UK, China, and South ...
Although most self-reactive T cells are eliminated in the thymus, mechanisms to inactivate or control T cells specific for extrathymic antigens are required and exist in the periphery. By investigating...Full Text Available
The glycolipid content of human non-seminomatous germ cell tumour cell lines correlates with their differentiation lineage. To analyse whether this reflects the situation in primary tumours, we studied...Full Text Available
One of the major decisions that germ cells make during their development is whether to differentiate into oocytes or sperm. In mice, the germ cells’ decision to develop as male or female depends...Full Text Available
DNA from the peripheral blood mononuclear cells of 17 different individuals infected with human T-cell lymphoma/leukemia virus type II (HTLV-II) was successfully amplified by the polymerase chain reaction...Full Text Available
It Peripheral blood progenitor enriched CD34+ cells (PBPC) are rather often used as stem cell background in cancer patients following high dose therapy. Keeping in mind that precursor dendritic cells (DCs) originate from haematopoietic progenitor cells, purified CD34+ cells might also serve as starting cells for ex-vivo production of DC. The aim of the present study is to develop a clinical grade procedure for ex-vivo production of DC derived from enriched CD34+ cells. Various concentrations of CD34+ cells were grown in gas-permeable Teflon bags with different serum-free and serum-containing media supplemented with GM-CSF, IL-4, TNF-a, SCF, Flt-3L and INF-a. Serum-free CellGroSCGM medium for 7 days followed by CellGroDC medium in 7 days gave equal results as serum-containing ...
Metastatic testicular germ cell tumours are cured in approximately 85% of patients using cisplatin-based combination chemotherapy. Patients who fail to respond have a poor prognosis, and there is a...Full Text Available
The first cell lineage specification in mouse embryo development is the formation of trophectoderm (TE) and inner cell mass (ICM) of the blastocyst. This article is to review and discuss the...Full Text Available
Zygotes of fucoid algae have long been studied as a paradigm for cell polarity. Polarity is established early in the first cell cycle and is then expressed as localized growth and invariant cell division....Full Text Available
Naturally occurring and contaminant ferromagnetic and ferrimagnetic particles have been found within or near cells, and might allow pulsed magnetic fields to create transient cell membrane opening ("pores")....Full Text Available
BackgroundClara cell protein (CC16), the main secretory product of bronchiolar Clara cells, plays an important protective role in the respiratory tract against oxidative stress and...Full Text Available
... ions. MATERIALS AND METHODS Cell Culture Culture of NT2/D1 cells was carried out as described previously (18, 19). NT2 cells were plated at a density of 2. ... ...
BackgroundPerfluorocarbons (PFC) are used to improve gas exchange in diseased lungs. PFC have been shown to affect various cell types. Thus, effects on alveolar type II (ATII) cells...Full Text Available
1. Paired or single recordings of paraventricular and/or supraoptic oxytocin cells at the beginning of suckling in urethane-anaesthetized rats enabled us to study cell recruitment and compare the characteristics...Full Text Available
Reaggregated cells from 6- to 8-day-old mouse cerebella have been used to raise antibodies in rabbits. The interaction of these antibodies with cerebellar cell surface components was assessed by cytotoxicity...Full Text Available
The cell types involved in the cellular immune response were studied with the GVH in vitro as a test system. Comparison of the activities of cells of different lymphoid organs in the...Full Text Available
Species differences in lifespan have been attributed to cellular survival during various stressors, designated here as ‘cell resilience’. In primary fibroblast cultures, cell...Full Text Available
We review the application of C. elegans as a model system to understand key aspects of stem cell biology. The only bona fide stem cells in C. elegans...Full Text Available
One of the main obstacles encountered when trying to culture human seminoma (SE) cells in vitro is massive degeneration of the tumour cells. We investigated whether dissociation of tumour tissue, to...Full Text Available
SummaryFor mammalian somatic cells the importance of microtubule cytoskeleton integrity in interphase cell cycle progression is uncertain. The loss, diminishment, or stabilization...Full Text Available
BACKGROUND--Interstitial lung diseases are characterised by the recruitment of mononuclear cells to disease sites where maturation occurs and activation products, including lysozyme (LZM), are released....Full Text Available
BackgroundA fundamental requirement for the exploitation of embryonic stem (ES) cells in regenerative medicine is the ability to reproducibly derive sufficient numbers of cells of...Full Text Available
Cultured mouse or human embryonic stem (ES) cells provide access to all of the genes required to elaborate the fundamental components and physiological systems of a mammalian cell. Chemical or insertional...Full Text Available
Fate maps are generated by marking and tracking cells in vivo to determine how progenitors contribute to specific structures and cell types in developing and adult tissue. An advance in this...Full Text Available
The results of the 2006 investigation of contaminant sources at Navarre, Kansas, clearly demonstrate the following: {sm_bullet} Sources of carbon tetrachloride contamination were found on the Navarre Co-op property. These sources are the locations of the highest concentrations of carbon tetrachloride found in soil and groundwater at Navarre. The ongoing groundwater contamination at Navarre originates from these sources. {sm_bullet} The sources on the Co-op property are in locations where the Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) never conducted grain storage operations. {sm_bullet} No definitive sources of carbon tetrachloride were identified on the portion of the current Co-op property formerly used by the CCC/USDA. {sm_bullet} The source areas on the Co-op property are consistent with the locations of the most intense Co-op operations, both historically and at present. The Co-op historically stored carbon tetrachloride for retail sale and used ...
It may result in acute radiation syndrome after body is exposed to ionizing radiation. The one of long-term effects of irradiation injury is leukemia. The bone marrow cells (BMC) transplantation including stem cells is the only effective therapy for acute radiation syndrome patients. Recently, with the advancement of stem cell research that the stem cells have multipotential and can convert each other, it may supply the new stem source for the irradiation injury patients. At the same time with the further research of radioprotective reagents, the hematopoietic stem cells proliferation after irradiation injury is promoted
In the last two years, rapid progress has been made in the energy conversion efficiencies of GaAs solar cells fabricated from molecular beam epitaxy (MBE) material. The efficiencies of cells fabricated from MBE material are now comparable with those fabricated from metal-organic chemical vapor deposition material, even for cells of dimension 2 cmx4 cm. This paper reviews the progress in MBE cell efficiencies. Also discussed is the role oval defects play in GaAs diode and solar cell performance. (orig.).
As concern regarding global environmental problems such as the greenhouse effect and acid rain has increased, so too has the demand for commercially viable solar cells as a clean energy source. Interest in amorphous silicon (a-Si) solar cells has been particularly high, due to their low cost. Technological developments in the field of a-Si solar cells are discussed from the viewpoints of fabrication process, materials, and cell structures. Various applications and systems that take advantage of the a-Si solar cell are then introduced. Finally, future prospects are mentioned
Transdifferentiation of an individual's own cells into functional differentiated cells to replace an organ's lost function would be a personalized approach to therapeutics. In this two part series, we will describe the progress toward establishing functional transdifferentiated adrenal cortical cells. In this article (Part 2), we describe the disorders of the adrenal cortex, therefore establishing why there is the need for personalized cell-based therapy for individuals with these disorders. We then present our pilot studies of cell transdifferentiation toward an adrenal cortical fate using genes described in the first article of this pair (Part 1).
In this contract, Laser-assisted processing techniques for producing high-quality solar cell metallization patterns are being investigated, developed, and characterized. The tasks comprising these investigations are outlined. Four new batches of solar cells were processed, in addition to several test runs on wafers, using the laser decomposition of spun-on silver neodecanoate to metallize cells. Decomposition of silver neodecanoate was carried out at different laser powers on different cells on a given wafer to determine whether this would have any effect on cell performance. A one watt laser power gave an electroplated linewidth of 50 microns , while at 8 watts the line width was 90 microns.
We report on multijunction GaInP/GaAs photovoltaic cells with total-area efficiencies of 29.5% at one-sun concentration and air mass (AM) 1.5 global and 25.7% one-sun, AM0. These values represent the highest efficiencies achieved by any solar cell under these illumination conditions. Three key areas in this technology are identified and discussed: the grid design, front surface passivation of the top cell, and bottom surface passivation of both cells. Aspects of cell design related to its operation under different solar spectra and under concentration are also discussed.
The theory for the general case of solar cells operating inside integrating cavity receivers is established. This is applied to the particular case of different configurations of silicon and GaAs cells. The results of the analysis show that a composite system of silicon and GaAs cells manufactured using relatively simple technology could reach an efficiency of 34%. The optimal configuration is that in which the GaAs cells are placed in the directly illuminated area of the receiver and the silicon cells are placed in the indirectly illuminated area of the receiver. (orig.).
pletely new PW fuel cell model had to be developed for CINDA. Several ...... following linear equation, which is used in the SINDA fuel cell model: ...
ObjectiveTo achieve osteochondral regeneration utilizing transplantation of cartilage-lineage cells and adequate scaffolds, it is essential to characterize the behavior of transplanted...Full Text Available
BackgroundThe evolution of eukaryotic cells is widely agreed to have proceeded through a series of endosymbiotic events between larger cells and proteobacteria or cyanobacteria,...Full Text Available
The molecular structure, chemical properties, and biological function of the xyloglucan polysaccharide isolated from cell walls of suspension-cultured sycamore (Acer pseudoplatanus)...Full Text Available
... Program: Quallion Matrix Design (small cells) - Investigate the feasibly of a hybrid battery matrix composed of small D-sized cells for use in HEVs ...
The most advanced frontier of allogeneic hematopoietic stem cell transplantation (allo-HSCT) is represented by the use of an HLA-partially matched relative as donor. In this type of transplantation, donor-derived natural killer (NK) cells, which are alloreactive towardtoward recipient cells, significantly contribute to the eradication of leukemia blasts. Alloreactive NK cells may also kill host dendritic cells and T lymphocytes, thus preventing graft-versus-host disease and graft rejection, respectively. Sophisticated strategies of adoptive infusion of T-cell lines/clones specific for the most life-threatening pathogens (namely cytomegalovirus, Epstein-Barr virus, Aspergillus and Adenovirus) have been envisaged, and successfully tested in a few pilot trials, to protect the recipient in the...
Gene expression is a fundamentally stochastic process, with randomness in transcription and translation leading to significant cell-to-cell variations in mRNA and protein levels. This variation...Full Text Available
Conditions were found in which Chlamydomonas reinhardi exhibits a circadian alteration of its cell surface, measured as ability to stick to glass. Under these same conditions the cells...Full Text Available
To examine the possibility that mast cells have a central role in the pathogenesis of hypersensitivity pneumonitis, 20 patients with this disease were studied with the aim of seeking evidence for mast...Full Text Available
Regulatory T cells are proposed to play a central role in the maintenance of immunological tolerance in the periphery, and studies in many animal models demonstrate their capacity to inhibit inflammatory...Full Text Available
There is a requirement for a noninvasive technique to monitor stem cell differentiation. Several candidates based on optical spectroscopy are discussed in this review: Fourier transform infrared (FTIR)...Full Text Available
Diverse cell polarity networks require positive feedback for locally amplifying distributions of signalling molecules at the plasma membrane1. Additional...Full Text Available
Morphological, Electrophysiological and Behavioral Investigations of the Nervous Tissue Developed from the Embryonic Matrix Zone Cells of the Dorsolateral Walls of Lateral Ventricles, Implanted into the Lesioned Regions of the Adult Rat's Brain
Jun 10, 2011 ... The PSSC is a picosatellite designed to test the space environment by providing a testbed to gather data on new solar cell technologies.
The present volume on modeling of batteries and fuel cells discusses the significance of the effectiveness factor for flooded porous electrodes, active pore distribution spectroscopy for characterizing porous battery electrodes, the agglomerate model for porous electrodes, and dynamic-performance measurements of battery cells for electric vehicles and other applications. Attention is given to mathematical modeling of a primary zinc/air battery, mathematical modeling of Grace Li-TiS2 cells, modeling of electrocrystallization processes in battery systems, and rotating disk electrode studies in molten Li/K carbonate eutectic. Topics addressed include the variability of nickel oxide cathode dissolution in molten carbonate fuel cells, water transport properties of fuel cell ionomers, modeling water content effects in polymer electrolyte fuel cells, and computer ...
Many mutations associated with retinal degeneration lead to the production of misfolded proteins by cells of the retina. Emerging evidence suggests that these abnormal proteins cause cell death...Full Text Available
Methods for improving the sensitivity of scintillation cells for radon concentration measurements were studied with emphasis on improving light collection efficiency. This allows the length and hence the volume of the cell to be increased. Variables studied were choice of scintillator material, its method of application and thickness, length of cell, cell material, type and configuration of reflectors, choice of photomultipliers, and factors affecting background. Response from various areas of the cell surface was studied with an alpha source and with radon filling. Coating the window with phosphor was found to be counter-productive. The optimum results obtained were with the inside of the cell (other than the window) covered with a thick layer of ZnS(Ag), or with a thick layer of reflective material coated with a thin layer of phosphor. With it, a 10 cm ...
Methods for improving the sensitivity of scintillation cells for radon concentration measurements were studied with emphasis on improving light collection efficiency. This allows the length and hence the volume of the cell to be increased. Variables studied were choice of scintillator material, its method of application and thickness, length of cell, cell material, type and configuration of reflectors, choice of photomultipliers, and factors affecting background. Response from various areas of the cell surface was studied with an alphy source and with radon filling. Coating the window with phosphor was found to be counter-productive. The optimum results obtained were with the inside of the cell (other than the window) covered with a thick layer of ZnS(Ag), or with a thick layer of reflective material coated with a thin layer of phosphor. With it, a 10 cm ...
Proliferating cells have been immunophenotypically characterized in lymph node and bronchoalveolar lavage (BAL) samples obtained from patients with active and inactive sarcoidosis with the cell-cycle-related...Full Text Available
Erythrocytes serve as reservoirs for cis- and trans-epoxyeicosatrienoic acids (EETs). Incubation of rat red blood cells (RBCs) with cis- and...Full Text Available
PASTICCINO (PAS) genes are required for coordinated cell division and differentiation during plant development. In loss-of-function pas mutants,...Full Text Available
PurposeTo analyze the expression of apoptosis and cell proliferation molecules in pterygium tissues of Chinese patients.MethodsThirty-three pterygia...Full Text Available
Proton exchange membrane (PEM) fuel cells are energy sources that have the ... for H2 /02 PEM fuel cells because their catalysts have properties suitable for 0 ...
Substantially genetically stable continuous human cell lines derived from normal human mammary epithelial cells (HMEC) and processes for making and using the same. In a preferred embodiment, the cell lines are derived by treating normal human mammary epithelial tissue with a chemical carcinogen such as benzo(a)pyrene. The novel cell lines serve as useful substrates for elucidating the potential effects of a number of toxins, carcinogens and mutagens as well as of the addition of exogenous genetic material. The autogenic parent cells from which the cell lines are derived serve as convenient control samples for testing. The cell lines are not neoplastically transformed, although they have acquired several properties which distinguish them from their normal progenitors. 2 tabs.
... with the loosening of Bush-era restrictions on stem cell research, a move that was widely hailed by the ... The first two explore the contentious debate over stem cell research. Using a series of intervie...
Cancer, by definition, is a proliferative disease. The fundamental scientific issue explored at the international symposium "Cell Proliferation and Chemical Carcinogenesis" was the impact of chemically...Full Text Available
Cells of the mononuclear phagocyte lineage have the capability to adhere to and fuse with each other and to differentiate into osteoclasts and giant cells. To investigate the macrophage adhesion/fusion...Full Text Available
Abstract: In many biological processes heterogeneity within clonal cell populations is an important issue. One of the most striking examples is a population of cancer cells in which after a common, identical death signal some cells die whereas others survive. The reason for this heterogeneity is intrinsic and extrinsic noise. In this paper we present a mechanistic multi-scale modeling framework for cell populations, in which the dynamics of every individual cell is captured by a parameter dependent stochastic differential equation (SDE). Heterogeneity among individual cells is accounted for by differences in parameter values, modeling extrinsic influences. Based on the statistical properties of the extrinsic noise and the SDE model for the individual cell, a partial differential equation (...
May 31, 2011 ... A Theoretical Solid Oxide Fuel Cell Model for System Controls and Stability Design AUTHOR(S): Kopasakis, George; Brinson, Thomas; Credle, ...
The existence of stem cells committed to the T lymphoid lineage was deduced from studying how rat T and B stem cells differ in their expression of membrane W3/13 antigen and in their susceptibility in vivo to gamma irradiation. Stem cell activity of rat bone marrow and fetal liver was measured in long-term radiation chimeras using B and T cell alloantigenic surface markers to identify the progeny of donor cells. Monoclonal mouse anti-rat thymocyte antibody W3/13 labeled approximately 40% of fetal liver cells and 60-70% of young rat bone marrow cells (40% brightly, 25% dimly). Bright, dim, and negative cells were separated on a fluorescence-activated cell sorter. All B and T lymphoid stem cells in fetal liver were W3/13 bright, as were B lymphoid stem cells in ...
We present a sample preparation method for measuring magnesium in individual whole lymphocytes by electron probe X-ray microanalysis. We use Burkitt's lymphoma cells in culture as the test sample and compare X-ray microanalysis of individual cells with atomic absorption analysis of pooled cell populations. We determine the magnesium peak-to-local continuum X-ray intensity ratio by electron probe X-ray microanalysis and calculate a mean cell magnesium concentration of 39 +/- 19 mmol/kg dry weight from analysis of 100 cells. We determine a mean cell magnesium concentration of 34 +/- 4 mmol/kg dry weight by atomic absorption analysis of pooled cells in three cell cultures. The mean cell magnesium concentrations determined by the two methods are not significantly different. We find a 10% coefficient of ...
The purpose of this review is to consider the hypothesis that cancer frequently originates from stem cells. Using the spleen transplantation assay where stem cells were transplanted in the spleen of mice lethally irradiated by ionizing radiation, the author undertook a study aimed at defining the risk of radiogenic cancer per susceptible cells with use of rat radiogenic mammary and thyroid cancers because of the high incidences of these cancers in a-bomb survivors. Measured were the number of cancer-susceptible cells initially present in the tissue, the number of such cells that survived at a given dose and the number of cancers that developed per surviving cell. Thyroid cell differentiation and proliferation in rats transplanted with thyroid cells were enhanced by thyroidectomy and low iodine diet. Further, the ...
Physiological functions are carried out by differentiated cells, with finite lifespans, which age and need to be replaced. In young individuals, tissue functions are sustained at optimal levels because cellular dysfunction and cell loss are balanced by the emergence of newly differentiated cells as stem cells and their partially differentiated descendants replicate. However, with the passage of time the mitotic rates of these cells diminish. Eventually, replications occur too infrequently to offset the loss. It is at this point that the tissue begins to show structural changes and declining function which, as they become pervasive, are identified as ageing. In this paper the theory is set forth that: (1) Diminishing mitotic activity in older tissues results from limited stem cell replicative capacity. (2) All stem cells, regardless of ...
Bone marrow is one of the most radiosensitive organs. Irradiation causes a marked decrease in the total number of hematopoietic cells in the bone marrow. The reticular meshwork structure of marrow stromal cells, however, is relatively resistant to irradiation. Unimpaired stromal cell structure has been thought to be a prerequisite for the repopulation of hematopoietic cells during recovery from the effects of irradiation. The reticular framework is maintained by cell adhesion apparatuses such as gap junctions. The in vitro radiobiologic survival values of a cloned stromal cell line, H-1/A, were studied (n = 1.8, D0 = 138 cGy). Radiation doses of up to 4000 cGy had no detectable effects on the production of colony-stimulating factor 1. H-1/A cells communicate with each other via gap junctions as determined by the sensitive dye-transfer ...
Bone marrow is one of the most radiosensitive organs. Irradiation causes a marked decrease in the total number of hematopoietic cells in the bone marrow. The reticular meshwork structure of marrow stromal cells, however, is relatively resistant to irradiation. Unimpaired stromal cell structure has been thought to be a prerequisite for the repopulation of hematopoietic cells during recovery from the effects of irradiation. The reticular framework is maintained by cell adhesion apparatuses such as gap junctions. The in vitro radiobiologic survival values of a cloned stromal cell line, H-1/A, were studied (n = 1.8, D0 = 138 cGy). Radiation doses of up to 4000 cGy had no detectable effects on the production of colony-stimulating factor 1. H-1/A cells communicate with each other via gap junctions as determined by the sensitive dye-transfer ...
The cell is modeled as an ellipsoid with shell and the surface stress distribution calculated by means of the Maxwell Stress Tensor. The cell membrane is treated as incompressible material having both bending and shear energies of deformation. Employing the principle of virtual work, cell volume (and hence shape) is computed as a function of the external field strength and orientation with respect to the field. The following results were obtained: (1) The surface stresses that develop or the cell membrane are distributed having both normal and tangential components that act together to produce a rounding of the cell. (2) If the tangential component of the stress is ignored, then higher field strengths are needed to produce similar deformation (shape change) of cells. (3) The threshold value of the applied field, i.e, the field strength at which the volume ...
The possibilities for therapy in the field of severe cardiac insufficiency have been extended in recent years by the introduction of novel agents endowed with a positive inotropic action. These substances may be arranged in two large classes: sympathomimetic agents and "non sympathomimetic--non digitalis-like" inotropic agents. The stimulant action of noradrenaline, adrenaline and isoproterenol on beta-adrenergic myocardial receptors has been clearly demonstrated but the usefulness of these medicines is limited by their positive chronotropic and arrhythmogenic actions. Dopamine and dobutamine have proved to be very useful in the treatment of patients in intensive care units. However, the exclusively intravenous route of administration limits their importance to the medium or long term. Several compounds, which are active by the oral route, have been the subject of therapeutic trials for the short or medium term. The problems posed by their use result, in the first place, from an ...
The accurate staging of rectal carcinoma is very important for treatment planning. The histological data obtained from surgical specimens of 22 patients with rectal carcinoma were compared with pre-and postoperative endorectal US findings and with preoperative CT results. According to an adapted version of Astler and Coller classification, the different degrees of tumor spread into the rectal wall were represented as follows: stage A: 1 patient; stage B1: 5 patients; stage B2: 6 patients; stage C1: 1 patient; stage C2: 8 patients and stage D: 1 patient. Preoperative staging, based on the overall results of CT and US, was in agreement with histology in 19 of 22 cases. Individual analysis of US and CT results, in comparison with histological data, showed US staging accuracy to be 77.3% (17/22 patients). US accuracy in demonstrating tumor spread into the rectal wall (stages A, B1, C1) was 100% (7/7 ...
Decaborane (B_1_0H_1_4) cluster ions were implanted into n-Si(100) substrates to fabricate shallow p"+/n junctions. Implant energies of 2 keV, 5 keV, and 20 keV, equivalent to implant energies of the monomer boron ion of 174 eV, 435 eV, and 1.74 keV, respectively, were used at dosages of 1 X 10"1"2 /cm"2 and 1 X 10"1"3 /cm"2. The implanted samples were then subjected to activation annealing at 800 .deg. C, 900 .deg. C, and 1000 .deg. C for 10 s. By using secondary ion mass spectrometry (SIMS) depth profiles, we determined that the depth of the shallow junction (D_s) at a dosage of 1 X 10"1"3 /cm"2 was in the range 12 nm - 45 nm after annealing at 1000 .deg. C. D_s and transient enhanced diffusion (TED) were greatly reduced at implant energies lower than 5 keV, but thermal diffusion (TD) smoothly decreased. In particular, TED was suppressed in the p"+/n junction implanted at 2 keV and a dosage of 1 X 10"1"3 /cm"2, and the formation of only a ...
The field of stem cell research was revolutionized with the advent of induced pluripotent stem cells. By reprogramming somatic cells to pluripotent stem cells, most ethical concerns associated with the use of embryonic stem cells are overcome, such that many hopes from the stem cell field now seem a step closer to reality. Several methods and cell sources have been described to create induced pluripotent stem cells and we discuss their characteristics in terms of feasibility and efficiency. From these cells, cardiac progenitors and cardiomyocytes can be derived by several protocols and most recent advances as well as remaining limitations are being discussed. However in the short time period this technology has been around, evidence emerges that induced pluripotent stem cells may ...
In order to study the neurobiological basis of seasonal changes in hippocampal structure and function, the rate of cell proliferation was examined in male and female wild meadow voles captured during different seasons. We found that the number of [3H]thymidine-labeled cells varied across the seasons and across sex in the meadow vole. Non-breeding female meadow voles had a higher rate of cell proliferation and cell death than males captured during either season or breeding females. These seasonal changes in the female meadow vole were associated with both fluctuating levels of adrenal steroids and gonadal steroids. Estradiol level was highly correlated with both the number of [3H]thymidine-labeled cells and the number of pyknotic cells in female meadow voles, with high levels of estradiol being associated with low levels of cell proliferation ...