The modes of action of the five major endo-(1----4)-beta-D-glucanases (I, II, III, IV and V) purified from Penicillium pinophilum cellulase were compared by h.p.l.c. analysis, with normal, 1-3H-labelled...Full Text Available
Studies of various established human bladder and renal carcinoma cell lines cultured in vitro demonstrated the presence of specific, saturable, high affinity binding sites for /sup 125/I-labeled human interferon Beta ser IFN-beta ser). This recombinant produced interferon labeled with approximately one atom of /sup 125/I/molecule of IFN expressed minimal or no loss of antiviral activity. A single class of binding sites (1000-2000/cell) with an affinity constant of 10(10)-10(11) L/M was measured at 4 degrees C for cells exhibiting widely different sensitivity to the antiproliferative effect of IFN-beta ser. Major fluctuations in the binding of /sup 125/I-labeled IFN-beta ser to cellular receptors were observed during in vitro proliferation of four of five cell lines examined. A significant decrease (P less than 0.001) in specific binding was ...
For many years, {beta} radioactivity has been used to label molecules and follow them in various biological processes. {beta} imaging is obtained by autoradiography. Classically made on films or on photographic emulsions, autoradiography is now supplanted by radio-imagers which are very performing. The phosphor-imager, {beta}-imager and {mu}-imager are the systems mainly used today and their operating principles and properties are compared. The great advantages of these imagers are: their rapidity to obtain results and their reliability for absolute quantification. All emitters ({beta}{sup -}, {beta}{sup -} -{gamma} and {beta}{sup +}) are detectable as well as the gamma emitters of nuclear medicine, by means of their low energy electrons ejected during y emission. Phosphor-imager is well suited to energetic tracers and large series of ...
The iodinated oil lipiodol is commonly used as a carrier for in situ delivery of drugs or radioactivity to hepatic tumors. Recently, we reported a new kit formulation for high-activity labeling of lipiodol with the {beta}-emitting radionuclide Re-188. Since the whole preparation involves different steps and complex manipulations of high-activity samples, we describe here an automated synthesis module that allows the easy preparation of sterile and pyrogen-free samples of Re-188 lipiodol ready to be administered to the patient. Important advantages include the possibility to incorporate high Re-188 activity into the lipiodol hydrophobic phase and a sharp reduction of radiation exposure of the operator assisting the labelling procedure. Application of this modular reaction system could be also extended to the preparation of other Re-188 radiopharmaceuticals and to compound labelled with different ...
Positron emission tomography (PET) imaging of {beta}-amyloid (A{beta}) plaques in the brain is a potentially valuable tool for studying the pathophysiology of Alzheimer's disease (AD). It may also be applicable for measuring the effectiveness of therapeutic drugs aimed at lowering A{beta} plaques in the brain. We have successfully reported a series of {sup 18}F-labeled fluoropegylated stilbenes for PET imaging studies. Encouraging results clearly demonstrated the usefulness of {sup 18}F-labeled stilbenes as potential A{beta} plaque-imaging agents. In the present study, we applied a similar approach to a styrylpyridine backbone structure. Among all derivatives examined (E)-2-(2-(2-(2-fluoroethoxy)ethoxy)ethoxy)-5-(4-dimethylaminostyryl) -pyridine (2) displayed high binding affinity in postmortem AD brain homogenates (K {sub i}=2.5{+-}0.4 nM, with [{sup ...
beta-Bungarotoxin (beta-Bgt), a presynaptic phospholipase A(2) (PLA(2)) neurotoxin isolated from the venom of Bungarus multicinctus, consists of A chain and B chain. The goal of the present study is to explore the functional contribution of the two subunits to the toxicity of beta-Bgt. beta-Bgt was found to induce apoptotic death of SK-N-SH cells via elevating intracellular Ca(2+) and intracellular ROS production. Moreover, an activation of p38 MAPK was associated with the cytotoxicity of beta-Bgt. SB202190 (p38 MAPK inhibitor), N-acetylcysteine (antioxidant reagent), 1,2-bis(2-aminophenoxy)ethane-N,N,N,N-tetraacetic acid (BAPTA) (Ca(2+) chelator) and the inhibitors of Ca(2+) release from intracellular depots (ruthenium red and 2-aminoethoxydiphenyl borate) effectively attenuated the cytotoxicity of beta-Bgt. In sharp contrast to the inability of A chain, B ...
Cultures of 3T3-L1 cells were incubated with either 10 ng/ml cholera toxin or 10 ng/ml pertussis toxin from 4 days prior to the initiation of differentiation and throughout the subsequent incubation. Toxin concentrations were sufficient to completely prevent the labelling of alpha-subunits with ["3"2P]NAD"+ and pertussis toxin and to prevent by more than 90% the labelling with ["3"2P]NAD"+ and cholera toxin in membranes prepared from these cells. Neither toxin prevented the differentiation to the adipocyte phenotype. Neither toxin prevented the increases in the relative amounts of G-proteins which occur upon differentiation. Both toxins dramatically decreased the amount of beta-subunits. As measured by quantitative immunoblotting with antisera specific for both the 35 kDa and 36 kDa beta-subunits, levels of beta-subunit were decreased by more than 50% of steady-state level of ...
Full text: Red blood cells (RBCs) labeled with "9"9"mTc are commonly used in the evaluation of cardiac function, gastrointestinal tract bleeding, red blood cell volume or splenic sequestration. Generally stannous ion is used as reducing agent. A proposed mechanism is that once the stannous ion (Sn) and the pertechnetate ("9"9"mTc) reach the interior of the RBC, the radionuclide is mainly house in the #beta#-chain of hemoglobin. The aim of this study was to determine if hemoglobin content reduction, an indicator of iron deficiency anemia, could affect the efficiency of RBC labeling and the biological distribution of this radiopharmaceutical. We studied 30 rats fed for 3 weeks after weaning with diets with iron contents of 6.5 ppm (group A), 18 ppm (group B) and 100 ppm (control). For all groups, the labeling yields were always higher than 97%; the percentage of radioactivity was mostly founded in blood ...
The soluble pool of alpha hemoglobin chains present in blood or bone marrow cells was measured with a new affinity method using a specific probe, beta A hemoglobin chain labeled with ["3H]N-ethylmaleimide. This pool of soluble alpha chains was 0.067 #+-# 0.017% of hemoglobin in blood of normal adult, 0.11 #+-# 0.03% in heterozygous beta thalassemia and ranged from 0.26 to 1.30% in homozygous beta thalassemia intermedia. This elevated pool of soluble alpha chains observed in human beta thalassemia intermedia decreased 33-fold from a value of 10% of total hemoglobin in bone marrow cells to 0.3% in the most dense red blood cells. The amount of insoluble alpha chains was measured by using the polyacrylamide gel electrophoresis in urea and Triton X-100. In beta thalassemia intermedia the amount of insoluble alpha chains was correlated with the decreased spectrin ...
Fatty acid esters such as Lipiodol or Ethiodol are known to selectively localize in vascular hepatocellular carcinomas (HCC), following intraarterial hepatic administration. Lipiodol was labeled with radioactive /sup 131/I and administered in 47 patients with HCC for both imaging and therapy. The short term preliminary results suggest radiolabeled Lipiodol is effective in eliminating ascites, shrinking the tumor by a high internal radiation dose, and in improving symptomatology of these tumors. In the future, /sup 90/Y, which is a stronger pure beta-emitter (maximum beta energy of 2.27 MeV, a half life of 64 h, and a maximum penetration or beta range of 11mm), than /sup 131/I will be used for more effective treatment of HCC.
Vulnerability of 25-hydroxy-(26,27-{sup 3}H)vitamin D{sub 3} 3{beta}-N-(4-azido-2-nitrophenyl)glycinate, a photoaffinity analogue of 25-hydroxyvitamin D{sub 3} (25-OH-D{sub 3}) toward standard conditions of carboxymethylationin promoted the authors to synthesize 25-hydroxyvitamin D{sub 3} 3{beta}-3{prime}-(N-(4-azido-2-nitrophenyl)amino)propyl ether (25-ANE), a hydrolytically stable photoaffinity analogue of 25-OH-D{sub 3}, and 25-hydroxyvitamin D{sub 3} 3{beta}-3{prime}-(N-(4-azido-2-nitro-(3,5-{sup 3}H)phenyl)amino)propyl ether ({sup 3}H-25-ANE), the radiolabeled counterpart of 25-ANE competes for the 25-OH-D{sub 3} binding site in rat serum vitamin D binding protein (rDBP). On the other hand, UV exposure of a sample of purified rat DBP (rDBP), preincubated in the dark with {sup 3}H-25-ANE, covalently labeled the protein. However, very little covalent labeling was observed in the ...
The processes of lung growth, injury, and repair are characterized by alterations in fibroblast synthesis and interstitial distribution of extracellular matrix components. Transforming growth factor beta (TGF-beta), which is postulated to play a role in modulating lung repair, alters the distribution of several matrix components such as collagen and fibronectin. We studied the effect of TGF-beta on the synthesis and distribution of the various glycosaminoglycans (GAGs) and whether these effects may explain its role in lung repair. Human diploid lung fibroblasts (IMR-90) were exposed to various concentrations of TGF-beta (0-5 nM) for variable periods of time (0-18 h). Newly synthesized GAGs were labeled with either (3H)glucosamine or (35S)sulfate. Individual GAGs were separated by size exclusion chromatography after serial enzymatic and chemical digestions and quantitated using ...
The aim of this paper was to develop potential technetium 99m-labeled diagnostic imaging agents specific for the detection of A#beta# plaques. Based on previously obtained A#beta# plaque-specific biphenyls containing a benzimidazol group, "9"9Tc"m and Re-benzimidazol derivatives, ["9"9Tc"m(CO)_3]"+-EPBI and Re(CO)_3 Cl (EPBI), were prepared. The latter showed binding affinities towards A#beta#_(_1_#approx#_4_0_) aggregates in vitro (K_d=13.3 #mu#mol/L) by fluorophotometry. 2-(1-Ethylbenzimidazol-2-yl) pyridine (EPBI) and Re(CO)_3 Cl (EPBI) were synthesized. Binding affinity of Re(CO)_3 Cl (EPBI) for A#beta#_(_1_#approx#__4_0_) aggregates was determined. ["9"9Tc"m(CO)_3]"+-EPBI was prepared and analyzed by HPLC and paper eletrophoresis. Its biodistribution in mice was obtained. The K_d value of Re (CO)_3 Cl (EPBI) is 13.3 #mu#mol/L. Biodistribution of ["9"9Tc"m(CO)_3]"+-EPBI in mice ...
Selectivity control is a key issue in the zeolite facilitated conversion of methanol to hydrocarbons. This work addresses: (a) How the zeolite topology (MFI versus BEA) determines the type of intermediate participating in the catalytic cycle thereby controlling the ethene/propene product selectivity in the methanol to alkenes reaction, and (b) to what extent light alkene formation occurs via aromatic and alkene reaction intermediates for H-ZSM-5. Three catalyst samples have been studied in experiments relying on isotopic labeling. For H-beta, penta- and hexamethylbenzene are involved in an aromatics based hydrocarbon pool type mechanism leading predominantly to propene and the higher alkenes (a very low yield of ethene is observed), whereas for H-ZSM-5, the lower methylbenzenes are the aro...
A combination of /sup 18/O-labeling experiments and kinetic studies to clarify the nonenzymatic hydrolytic pathways of adenosine 5'-triphosphate (ATP) at pH values ranging from 0 to 8.3 has been used in this experiment. In 1 N and 0.1 N HCl, the data are consistent with the hypothesis that hydrolysis occurs by addition-elimination, with initial attack 93% ..gamma.. and 7% ..beta..; both lead only to ADP + P/sub i/. In the subsequent hydrolysis of the ADP to AMP + P/sub i/, attack is 83% ..beta.. and 17% ..cap alpha... At pH 8.3, the data are consistent with the hypothesis that hydrolsysis occurs by elimination-addition. Over the entire pH range studied, no oxygen exchange between water and ATP, ADP, or P/sub i/ was detected. Nonenzymatic hydrolysis and isotopic analysis of the resultant P/sub i/ comprise a preferred means of assaying the isotopic enrichment of (..gamma..-/sup 18/O)ATP to be used in studies of ...
Aim: Compounds such "9"9"mTc-MDP and "9"9"mTc-HEDP are used regularly in bone scintigraphy for metastasis detection. The therapeutics properties of beta emitter radionuclides like "1"5"3Sm, "1"6"6Ho and "1"7"7Lu has been widely reported in literature being "1"7"7Lu the less developed for medical applications. With the purpose of study different radiopharmaceuticals alternatives, for metastasis bone palliation, we have evaluated, on a comparative basis, the labeling of "1"5"3Sm-MDP, "1"5"3Sm-HEDP, "1"6"6Ho-MDP, "1"6"6Ho-HEDP, "1"7"7Lu-MDP and "1"7"7Lu-HEDP from the exhibited radionuclidic purity and biological distribution point of view. Material and Methods: The radionuclides were produced at La Reina Research Reactor, Chilean Nuclear Energy Commission. The radionuclidic purity was determined by gamma-Ray spectrometry. The labeling was accomplished with MDP (Plenum) and HEDP synthesized in-house. The in-vitro affinity of ...
The aim of this work is the evaluation of biodistribution and radiation dosimetry of a cocaine analog, the N-(3-iodo-prop-2E-enyl)-2beta-carbo-methoxy-3beta-(4-methyl-phenyl) nor-tropane (PE2I), labeled with carbon 11 ([{sup 11}C]PE2I). The [{sup 11}C]PE2I is a selective radioligand for imaging neuronal dopamine transporter (DAT) with positron emission tomography (PET). The DAT is a membrane-bound pre synaptically located protein that regulates the concentration of dopamine at nerve terminals. DAT radioligands are often used to evaluate the progression of Parkinson's disease or the efficiency of neuro-protective therapeutics and, typically, these studies required several successive PET scans. (author)
The determination of the banned anabolic substance zeranol and the metabolites taleranol and zearalanone in bovine urine is complicated by the occurrence of the structurally-related mycotoxin zearalenone and the corresponding {alpha}- and {beta}-zearalenol metabolites which possess similar estrogenic properties. A liquid chromatography-negative ion electrospray tandem mass spectrometric method is presented for the confirmatory analysis of all six resorcylic acid lactones ('zeranols') in urine samples using deuterium-labelled internal standards. The method was validated as a confirmatory method for bovine urine samples according to new draft EU guidelines and showed good precision and linearity, and CC{alpha} and CC{beta} values of 0.02-0.30 and <1.0 ng ml{sup -1}, respectively. The applicability was demonstrated by comparing the results of an incurred sample with previous results on the same sample ...
A portion of the active site of rabbit skeletal myosin near the ribose ring of ATP can be labeled by the photoaffinity analogue 3{prime}(2{prime})-O-(4-benzoylbenzoyl)adenosine triphosphate (Bz{sub 2}ATP). The specificity of the photolabeling was assured by first trapping ({sup 14}C)Bz{sub 2}ATP at the active site by use of thiol cross-linking agents. Five radioactive peptides were isolated by high-performance liquid chromatography after extensive trypsin and subtilisin digestion of photolabeled myosin subfragment 1. Four of these peptides were sequenced by Edman techniques, and all originated from a region with the sequence Gly-Glu-Ile-Thr-Val-Pro-Ser-Ile-Asp-Asp-Gln, which corresponds to rabbit myosin heavy chain residues 312-328. The fifth labeled peptide had an amino acid composition appropriate for residues 312-328. Amino acid composition, radiochemical analysis, and sequence data indicate that Ser-324 is the major amino acid residue ...
Vildagliptin is a potent and selective dipeptidyl peptidase IV inhibitor in development for the treatment of type 2 diabetes that improves glycemic control by enhancing alpha- and beta-cell responsiveness to glucose. Two open-label, single-dose, randomized, crossover studies in healthy subjects (ages 18-45 years) investigated the dose proportionality of vildagliptin pharmacokinetics (n = 20) and the effect of food (n = 24) on vildagliptin pharmacokinetics. There was a linear relationship (r(2) = 0.999) between vildagliptin doses of 25, 50, 100, and 200 mg and area under the plasma concentration-time curve from time zero to infinity (AUC(0-infinity)) and maximum plasma concentration (C(max)). Dose proportionality was assessed using a statistical power model [X = alpha x (dose)(beta)]. The 90% confidence intervals of the proportionality coefficient, beta, for AUC(0-infinity) (1.15-1.19) and C(max) ...
The authors have investigated insulin receptor phosphorylation in differentiated cultured BC3H-1 myocytes. As for other insulin-responsive cell systems in partially purified wheat germ agglutinin receptor preparations, insulin stimulates the phosphorylation of its own receptor (95K ..beta..-subunits) in a dose dependent manner (0-400 nM), as identified by immunoprecipitation with antiinsulin receptor antibodies and SDS-PAGE. In the same preparations they show that 12-0-tetradecanyl phorbol acetate (TPA), which in many respect ..beta..-subunits in the same dose dependent manner (0-5 ..mu..M). In addition, antiinsulin receptor antibodies (B-10) also induced phosphorylation of mimics insulin action, also induced phosphorylation of the insulin receptor and HPLC tryptic maps of the /sup 32/P-labeled ..beta..-subunit were identical to those for insulin-induced receptor phosphorylation. However, while insulin ...
In the course of a prenatal diagnosis for beta thalassaemia by linkage analysis of restriction fragment length polymorphisms, a homozygous beta thalassaemia fetus was misdiagnosed as beta thalassaemia...Full Text Available
The {sup 176}Ybn,{gamma}{sup 177}Yb-{beta}{sup -}{yields}{sup 177}Lu process was investigated to provide no-carrier-added (nca) {sup 177}Lu. The radiochemical separation of the {sup 177}Lu from the macro-amounts of the ytterbium target based on the cementation process, i.e. the selective extraction of Yb by Na(Hg) amalgam from Cl{sup -}/CH{sub 3}COO{sup -} electrolytes, followed by a final cation exchange purification. The cementation separation process provides a decontamination factor of Yb(III) of 10{sup 4}, the cation exchange purification adding a decontamination factor of >10{sup 2}. The nca {sup 177}Lu is available in radiochemically pure form despite the chemical similarity of the lanthanides with 75{+-}5% overall separation yield within 4-5 h. It can be used to synthesise nca {sup 177}Lu labelled radiotherapeuticals.
[alpha]-Melanocyte stimulating hormone ([alpha]-MSH), a hormone originally named for its ability to regulate pigmentation of melanocytes, is a 13-amino-acid post-translational product of the pro-opiomelanocortin (POMC) gene. [alpha]-MSH and the other products of POMC processing, which share the core heptapeptide amino acid sequence Met-Glu (Gly)-His-Phe-Arg-Trp-Gly (Asp), the adrenocorticotropic hormone (ACTH), [beta]-MSH, and [gamma]-MSH, are collectively referred to as melanocortins. While best known for their effects on the melanocyte (pigmentation) and adrenal cortical cells (steroidogenesis), melanocortins have been postulated to function in diverse activities, including enhancement of learning and memory, control of the cardiovascular system, analgesia, thermoregulation, immunomodulation, parturition, and neurotrophism. To identify the chromosomal band encoding the human melanocortin-1 receptor gene, 1 [mu]g of an EMBL clone coding region of the human MC1R ...
Radionuclides exhibiting in decaying a strong interaction between nucleus and electron shell (especially electron capture and internal conversion) are, in principle, sensitive to their chemical surroundings. Consequently, they can be used to yield chemical information after an appropriate labelling procedure. The information can be extracted from the decay rate variation as well as from their X-ray emission as a response to an inner-shell vacancy creation during nuclear deexcitation. As an example of the former method the relationship between the decay rate of /sup 99m/Tc and the chemical structures of pertechnetate and bis(meso-dimercapto-succinate)oxotechnetate(V) is considered. Lower expectations with respect to measuring techniques are associated with the observation of X-ray emission. For a number of elements (especially 3d transition elements) the K/sub ..cap alpha..//K/sub ..beta../ X-ray intensity ratio was found to be an indicator of ...
Hepatocellular carcinoma (HCC) is the most common primary liver cancer and has very limited therapeutic options. Recently, it has been found that hyaluronic acid (HA) shows selective binding to CD44 receptors expressed in most cancer histotypes. Since the trend in cancer treatment is the use of targeted radionuclide therapy, the aim of this research was to label HA with rhenium-188 and to evaluate its potential use as a hepatocarcinoma therapeutic radiopharmaceutical. Methods: {sup 188}Re-HA was prepared by a direct labelling method to produce a ReO(O-COO){sub 2}-type coordination complex. {sup 188}Re-HA protein binding and its stability in saline, phosphate buffer, human serum and cysteine solutions were determined. Biokinetic and dosimetric data were estimated in healthy mice (n=60) using the Medical Internal Radiation Dose methodology and mouse model beta-absorbed fractions. To evaluate liver toxicity, alanine ...
Radiopharmaceuticals for brain imaging are used for the detection of ischemia, tumours and dementia associatied with disorders of the blood flow in the brain. The current radiopharmaceuticals for brain imaging have various limitations: 2-(F-18)fluoro-2-deoxyglucose (F-18-FDG) has a very short half-life. The physical properties of di-#beta#-(piperidinoethyl)-(Se-75)selenide (Se-75-PIPSE) and di-#beta#-(morpholinoethyl)-(Se-75)-selenide (Se-75-MOSE) are not ideal. Thallium-201 diethyldithricarbamate (T1-201-DDC) has unfavourable nuclidic characteristics, limited availability, a long half-life and high cost. I-123 in N-isopropyl-p-iodoamphetamine (I-123-IMP) and N,N,N'-trimethyl-N'-(2-hydroxy-3-methyl-5-iodobenzyl)-1,3-propanediamine (I-123-HIPDM) are not freely available and are expensive. N-13-labelled ammonia has a very short half-life. Technetium-99m hexamethylpropyleneamineoxime (Tc-99m-HM-PAO) is unstable both in vitro ...
Rabbit antisera raised to human and chicken MHC molecules were used to immunoprecipitate cross-reactive molecules from biosynthetically and cell surface-labeled spleen and/or blood cells of representative vertebrate species. Five major points emerged: 1) There were many nonspecific cross-reactions using these techniques, so various criteria were developed to distinguish these from true MHC-like molecules. 2) Only very small subpopulations of immunogen-specific antibodies cross-reacted with MHC-like molecules in other nonmammalian species. These subpopulations were different for each species and even within a species, sometimes being so limited as to behave like alloantisera. This led to a very scattered pattern of true cross-reactions that sometimes failed to reflect the properties of the bulk antibody population. 3) Antisera containing antibodies to class II beta- and class I alpha-chains cross-reacted better and more widely than those to B-G, ...
Attention deficit hyperactivity disorder (ADHD) is a psychiatric disorder in childhood that is known to be associated with dopamine dysregulation. In this study, we investigated dopamine transporter (DAT) density in children with ADHD using iodine-123 labelled N-(3-iodopropen-2-yl)-2β-carbomethoxy-3β-(4-chlorophenyl) tropane ([{sup 123}I]IPT) single-photon emission tomography (SPET) and postulated that an alteration in DAT density in the basal ganglia is responsible for dopaminergic dysfunction in children with ADHD. Nine drug-naive children with ADHD and six normal children were included in the study. We performed brain SPET 2 h after the intravenous administration of [{sup 123}I]IPT and carried out both quantitative and qualitative analyses using the obtained SPET data, which were reconstructed for the assessment of the specific/non-specific DAT binding ratio in the basal ganglia. We then ...
Several commonly occurring freshwater and marine plants and algae were screened for beta-D-galactosidase and beta-D-glucuronidase activities by using a 60-min enzyme assay based on the hydrolysis by...Full Text Available
Iodine-125 labelled vinyl and aryl iodides are formed via the reaction of sodium iodide-125 with vinyl- and arylboronic acids. Good yields of isomerically pure products are obtained.
To determine whether PKH26 labeling affects the morphologies, phenotypes, proliferation, and secretion abilities of human umbilical mesenchymal stromal cells (HUMSCs) were investigated. Isolated HUMSCs were labeled with PKH26, and cell morphology was observed under microscope. Cell cycle, apoptotic cell death, expression of PKH26, and the proliferation rate were evaluated. Additionally, fluorescence intensity of PKH26 labeling at different passage times was quantified. There were no detectable differences in cell morphology, cell growth, and proliferation rate after PKH26 labeling. In addition, fluorescence intensity of PKH26 labeling was gradually reduced with increase of the passage times. The PKH26 labeling disappeared after passage six times. In summary, PKH26 labeling is a safe and ef...
Transforming growth factor (TGF)-beta isoforms (TGF-beta 1, -beta 2, and -beta 3) regulate cell growth and differentiation and have critical regulatory roles in the process of tissue repair and remodeling....Full Text Available
The present investigation compares the suitability of two radiolabeling techniques for hemoglobin. "1"2"5I labeling of hemoglobin with Iodogen as iodinating agent caused major changes in the chromatographic behaviour and an accelerated plasma clearance of the labeled hemoglobin in rats. A recently developed two-step procedure for "9"9"mTc labeling gave better results. The label had only minimal influence on the chromatographic behaviour of hemoglobin. In vivo, no free label occurred in the circulation and no transfer of the label to other plasma proteins took place. The plasma clearance of "9"9"mTc-labeled hemoglobin in rats was slowed. However, this could be explained entirely by diminishing glomerular filtration, probably by inhibition of the dissociation of the hemoglobin molecule into dimers. The plasma clearance of hemoglobin modified ...
A general method for stable-isotope labeling of large proteins is introduced and applied for studies of the E. coli GroE chaperone proteins by solution NMR. In addition to enabling the residue-specific {sup 15}N-labeling of proteins on a highly deuterated background, it is also an efficient approach for uniform labeling. The method meets the requirements of high-level deuteration, minimal cross-labeling and high protein yield, which are crucial for NMR studies of structures with sizes above 150 kDa. The results obtained with the new protocol are compared to other strategies for protein labeling, and evaluated with regard to the influence of external factors on the resulting isotope labeling patterns. Applications with the GroE system show that these strategies are efficient tools for studies of structure, dynamics and intermolecular interactions in large ...
In the present study the authors have shown that glycoproteins are present in the plasma membrane of Acanthamoeba castellanii by utilizing different radioactive labeling techniques. Plasma membrane proteins in the amoeba were iodinated by "1"2"5I-lactoperoxidase labeling and the solubilized radiolabeled glycoproteins were separated by lectin-Sepharose affinity chromatography followed by polyacrylamide gel electrophoresis. The periodate/NaB"3H_4 and galactose oxidase/NaB"3H_4 labeling techniques were used for labeling of surface carbohydrates in the amoeba. Several surface-labeled glycoproteins were observed in addition to a diffusely labeled region with M_r of 55,000-75,000 seen on electrophoresis, which could represent glycolipids. The presence of glycoproteins in the plasma membrane of Acanthamoeba castellanii was confirmed by metabolic ...
We have found that the methionine repression of the ..beta..-subunit gene expression is not due to degradation of the ..beta..-subunit but is due to an effect on synthesis of the ..beta..-subunit. The effect of methionine on the synthesis of the ..beta..-is due to an inhibition of ..beta..-subunit mRNA synthesis. 3 references, 1 figure.
The physical methods were used to study the decomposition of a metastable #beta#-solid solution in the VT22 two-phase titanium alloy. It is shown that the martensitic #beta# #-># #alpha#'' transformation in doped-element depleted microvolumes of the #beta#-solid solution are dominanted and the long-time multistage decomposition through a number of intermediate states in others.
Calculations for a single-j nucleon coupled to an axially symmetric core with both #beta#_2 and #beta#_4 deformation have been performed for "1"8"7Ir. Using #beta#_4=-0.08, consistent with previously measured and predicted values of #beta#_4, the calculated spectrum is competitive with recent calculations assuming an asymmetric core.
Differences of the deformation parameters for the 2"+_1 states of even-even spherical nuclei extracted from electromagnetic excitation #beta#sup(em)_2 and from proton scattering #beta#sup(pp')_2 are discussed. It is found that the ratio #beta#sup(pp')_2/#beta#sup(em)_2 is equal to about unity and that there is a small isotope dependence for several incomplete shell nuclei. (orig.).
BackgroundIn recent years, near-infrared fluorescence (NIRF)-labeled iron nanoparticles have been synthesized and applied in a number of applications, including the labeling of human cells for monitoring the engraftment process, imaging tumors, sensoring the in vivo molecular environment surrounding nanoparticles and tracing their in vivo biodistribution. These studies demonstrate that NIRF-labeled iron nanoparticles provide an efficient probe for cell labeling. Furthermore, the in vivo imaging studies show excellent performance of the NIR fluorophores. However, there is a limited selection of NIRF-labeled iron nanoparticles with an optimal wavelength for imaging around 800 nm, where tissue autofluorescence is minimal. Therefore, it is necessary to develop additional alternative NIRF-labeled iron nanoparticles for application in this area.ResultsThis study ...
Phospho-beta-galactosidase (P-beta-gal), the enzyme which catalyzes the first step in the metabolism of intracellular lactose phosphate, occurred at high specific activity in the cytoplasm in 12 of...Full Text Available
By use of a new computer-assisted u.v.-spectrophotometric assay method, the kinetic parameters of the reaction catalysed by Bacillus licheniformis 749/C beta-lactamase were re-examined and the mode...Full Text Available
The rate constants for both acylation and deacylation of beta-lactamase PC1 from Staphylococcus aureus and the RTEM beta-lactamase from Escherichia coli were determined by the acid-quench method [Martin...Full Text Available
Polyclonal antibodies were raised in rabbits by immunization with free peptides corresponding to positions 197-222 of the human beta 1-adrenergic receptor (beta 1 peptide) and the corresponding sequence...Full Text Available
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 decreased relative to the untreated control livers, depending on the treatment. Similarly, ...
Tumor-targeted monoclonal antibodies (mAb) might be useful as diagnostic or therapeutic agents when linked to cytotoxic or imaging reagents. Our group is working to test this hypothesis by linking cytocidal and image-producing isotopes to mAb and testing the utility of the radioimmunoconjugates formed in animal model systems. Radioiodines were first employed for these purposes,but unfavorable nuclear properties (half-lives, #gamma#-ray and #beta#-particle energies) and chemical reactivity (deiodination in vivo) limit their utility. Labeling immunoproteins with metallic radionuclides offers more versatility in that the selection of potentially useful radiometals spans the periodic table.Of the metallic radionuclides with physical properties most suited for use with mAb in nuclear medicine, few are more available or desirable than those of bismuth ("2"1"2Bi) and lead ("2"0"3Pb, "2"1"2Pb), as listed in Table 1. "2"1"2Bi or "2"1"2Pb could serve as ...
Prostaglandin E2 (PGE2) has been shown to increase the synthesis of hyaluronic acid in cultured fibroblasts by increasing the activity of hyaluronate synthetase, a group of plasma membrane-bound synthetic enzymes. We examined whether PGE2 also increased the activity of those enzyme systems involved in the synthesis of sulfated glycosaminoglycan in the human embryonic lung fibroblast. Exposure of cells to PGE2 resulted in dose-dependent increases in glucosamine incorporation into all sulfated glycosaminoglycan subtypes. PGE2 at 10(-7) mol/L increased total glycosaminoglycan per dish to 21.6 +/- 3.1 micrograms versus 12.0 +/- 2.5 micrograms in control untreated cultures. Stimulation of endogenous PGE2 production by bradykinin had a similar effect on glycosaminoglycan synthesis. To examine whether PGE2 affected sulfated glycosaminoglycan protein core production, cells were labeled with tritiated glucosamine in the presence of cycloheximide. Under these conditions, ...
{sup 188}Re is a {beta}{sup -} (Emax=2.12 MeV) and {gamma} (155 keV) emitter. Since its chemistry is similar to that of the largely employed tracer, {sup 99m}Tc, molecules of hyaluronic acid (HA) have been labelled with {sup 188}Re to produce a target specific radiopharmaceutical. The radiolabeled compound, i.v. injected in healthy mice, is able to accumulate into the liver after a few minutes. To study the effect of metabolic radiotherapy in mice, we have built a small gamma camera based on a matrix of YAP:Ce crystals, with 0.6x0.6x10 mm{sup 3} pixels, read out by a R2486 Hamamatsu PSPMT. A high-sensitivity 20 mm thick lead parallel-hole collimator, with hole diameter 1.5 mm and septa of 0.18 mm, is placed in front of the YAP matrix. Preliminary results obtained with various phantoms containing a solution of {sup 188}Re and with C57 black mice injected with the {sup 188}Re-HA solution are presented. To increase the space resolution and to ...
Radioiodinated 15-(p-iodophenyl)-3,3-dimethylpentadecanoic acid (DMIPP) has been prepared as a new terminal iodophenyl-substituted fatty acid containing dimethyl-branching at the beta-position. Iodine-125-labeled DMIPP showed rapid, high myocardial uptake (min, mean % injected dose/g) in fasted rats (5, 4.67; 30, 5.06; 60, 4.79; 120, 4.37), and also exhibited high heart:blood ratios (min, ratio) 5, 3:1; 30, 12:1; 60, 12:1; 120, 13:1. These data demonstrate an unanticipated much longer myocardial residence time with DMIPP (+/sub 1/2/ 7-8 h) than observed with either the 3-monomethyl (BMIPP) analogue (+/sub 1/2/ 30-45 min) or the rapidly metabolized straight-chain (IPP) analogue (+/sub 1/2/ 10-15 min). The (/sup 123/I)DMIPP is thus an excellent candidate for clinical evaluation of regional fatty acid metabolism under conditions where the uptake of energy substrates can be assessed independent of regional blood delivery. Studies with the new ...
Glycosaminoglycan synthesis was studied in cell populations of ultraviolet light-induced murine cutaneous fibrosarcoma cells under conditions of varying growth rates in vitro. After labeling with the precursors, /sup 3/H-glucosamine and /sup 35/SO/sub 4/, sulfated glycosaminoglycans recoverable by direct proteolysis of the culture monolayers increased approximately 5-fold on a per cell basis from sparsely populated, exponential cell cultures (greater than 85% of cells in S, G2, or M phases) to stationary cultures inhibited by high cell density (greater than 50% of cells in G1). Within this cell surface-associated material, the relative ratio of heparan sulfate to the chondroitin sulfates was approximately 60/40% under conditions of exponential growth; in the growth-arrested cultures, the reverse ratio was found. The substratum attached material, obtained from the flask surface after ethyl glycol bis(beta-aminoethyl ...
Autoreactive cytotoxic CD8 T-cells (CTLs) play a key pathogenic role in the destruction of insulin-producing beta-cells resulting in type 1 diabetes. However, knowledge regarding their targets is limited, restricting the ability to monitor the course of the disease and immune interventions. In a multi-step discovery process to identify novel CTL epitopes in human preproinsulin (PPI), PPI was digested with purified human proteasomes, and resulting COOH-fragments aligned with algorithm-predicted HLA-binding peptides to yield nine potential HLA-A1, -A2, -A3 or -B7-restricted candidates. An UV-exchange method allowed the generation of a repertoire of multimers including low-affinity HLA-binding peptides. These were labeled with quantum dot-fluorochromes and encoded in a combinatorial fashion, allowing parallel and sensitive detection of specific, low-avidity T-cells. Significantly increased frequencies of T-cells against four novel PPI epitopes ...
Hilled Bend Spechene of an Alpha-Beta Titanium Alloy. Ti-6M14V. ..... The all beta titanium alloy was nllled from both sides; only the edges were taped. ...
Observations concerned with the formation of isothermal #omega# in the beta-titanium alloy RMI (38-6-44) are presented as part of a more general study of the aging characteristics of the alloy.
Functional activation of {beta}-catenin/Tcf signaling plays an important role in early events in carcinogenesis. We examined the effect of naringenin against {beta}-catenin/Tcf signaling in gastric cancer cells. Reporter gene assay showed that naringenin inhibited {beta}-catenin/Tcf signaling efficiently. In addition, the inhibition of {beta}-catenin/Tcf signaling by naringenin in HEK293 cells transiently transfected with constitutively mutant {beta}-catenin gene, whose product is not phosphorylated by GSK3{beta}, indicates that its inhibitory mechanism was related to {beta}-catenin itself or downstream components. To investigate the precise inhibitory mechanism, we performed immunofluorescence, Western blot, and EMSA. As a result, our data revealed that the {beta}-catenin distribution and the levels of nuclear ...
Screening of a human placenta lambdagt11 library has led to the isolation of the cDNA for the human ..beta../sub 1/-adrenergic receptor (..beta../sub 1/AR). Used as the probe was the human genomic clone termed G-21. This clone, which contains an intronless gene for a putative receptor, was previously isolated by virtue of its cross hybridization with the human ..beta../sub 2/-adrenergic receptor (..beta../sub 2/AR). The 2.4-kilobase cDNA for the human ..beta../sub 1/AR encodes a protein of 477 amino acid residues that is 69% homologous with the avian ..beta..AR but only 54% homologous with the human ..beta../sub 2/AR. This suggests that the avian gene encoding ..beta..AR and the human gene encoding ..beta../sub 1/AR evolved from a common ancestral gene. RNA blot analysis indicates a message of 2.5 ...
Three photaffinity labeled derivatives of epothilone D were prepared by total synthesis, using efficient novel asymmetric synthesis methods for the preparation of two important synthetic building...Full Text Available
High resolution structural elucidation of macromolecular structure by solid-state nuclear magnetic resonance requires the preparation of uniformly aligned samples that are isotopically labeled. In...Full Text Available
Rat somatotropin (growth hormone) was labelled biosynthetically by incubating anterior pituitary lobes with radioactive amino acids for 24 h in a simple buffered salts medium containing glucose. The...Full Text Available
We describe a clustering method for labeled link network (semantic graph) that can be used to group important nodes (highly connected nodes) with their relevant link's labels by using PARAFAC tensor decomposition. In this kind of network, the adjacency matrix can not be used to fully describe all information about the network structure. We have to expand the matrix into 3-way adjacency tensor, so that not only the information about to which nodes a node connects to but by which link's labels is also included. And by applying PARAFAC decomposition on this tensor, we get two lists, nodes and link's labels with scores attached to each node and labels, for each decomposition group. So clustering process to get the important nodes along with their relevant labels can be done simply by sorting the lists in decreasing order. To test the method, we construct ...
Objective:In this article, we describe a successful low-dose, off-label usage of drotrecogin alfa (Xigris), given at 18 mcg/kg per hour, in a patient with severe sepsis who had an...Full Text Available
Electron spin resonance (ESR) studies have been performed on spin-labeled model membranes aligned using the isopotential spin-dry ultracentrifugation (ISDU) method of Clark and Rothschild. This method...Full Text Available
BackgroundObesity is a major public health threat and policies aimed at curbing this epidemic are emerging. National calorie labeling legislation is forthcoming and requires rigorous...Full Text Available
BackgroundGenotyping analysis using capillary DNA sequencing with fluorescently labeled primer pairs obtained by polymerase chain reaction (PCR) is widely used, but is expensive....Full Text Available
The basic approach to radioactive labeling techniques in hemoglobin identification consists of mixing 14C labeled normal carrier globin with 3H labeled unknown globin and carrying out the subsequent separations and purifications looking at the distribution of 3H and 14C radioactivity. This technique was devised to ascertain the amino acid substitution in Hb Indianapolis and was instrumental in solving the structure of Hb Vicksburg. It was also useful in determining the purity of gamma-chains from cultures of human and baboon erythroid progenitors. Another use of this technique would be in identifying aberrant peaks of radioactivity in chain separation chromatograms, such as ''pre-peaks''.
Astatine conversed into cationic form is shown to form stable complex with diethylenetriaminpentacetic acid. Due to this complex astatine joins RN_2 type monoclonal antibodies. More favorable conditions to prepare astatine labelled antibodies are found. Chromatographical analysis and electromigration experiments have shown that astatine is strongly retained in in-vitro biomolecule. Astatine did not escape from the labelled antibodies even in case of urea effect on them. Immune activity of astatine labelled antibodies remained similar in 20 h. 28 refs., 4 figs.
A useful method for preparing radioiodinated photoaffinity labels from alkyl anilines which offer significant advantages over present methods is described. The one-pot synthesis gives good radiochemical yields (40-64%) of pure, high specific activity (350-1500 mCi/#mu#mol) "1"2"4I labelled iodaryl azides while minimising manipulation of radioactive materials. Purification of the ["1"2"5I]iodoazido photoaffinity labels is achieved by high performance liquid chromatography. (author).
A useful method for preparing radioiodinated photoaffinity labels from alkyl anilines which offer significant advantages over present methods is described. The one-pot synthesis gives good radiochemical yields (40-64%) of pure, high specific activity (350-1500 mCi/{mu}mol) {sup 124}I labelled iodaryl azides while minimising manipulation of radioactive materials. Purification of the ({sup 125}I)iodoazido photoaffinity labels is achieved by high performance liquid chromatography. (author).
The synthesis of (/sup 14/C)-10,11-Epoxy-(2E,6E)-farnesyl diazoacetate in one vessel, starting from (/sup 14/C)-glyoxylic acid, is described. This compound is useful as a potential photoaffinity labeling agent for juvenile hormone binding sites.
The influence of heat treatment on the structure, mechanical properties and fracture peculiarities of high-strength (#alpha#+#beta#)-titanium alloy VT22 has been studied. It is ascertained that thermal cycling and subsequent high-temperature aging permit to reduce considerably crack growth rate. Thermal cycling is realized in the following mode: heating in #beta#-region, cooling and allowance in (#alpha#+#beta#)-region, heating in #beta#-region.
In this paper a study is made of the structure and mechanical properties of the #beta# alloy system Ti-Mo-Zr-Sn (the composition of which is equivalent to the #beta# III alloy used abroad) containing different amounts of carbon. Study of the #beta#-titanium alloy containing 0.1% C revealed the presence of particles of titanium carbide. Separation of the titanium carbide promotes a reduction in impact strength, an increased tendency toward cold shortness, and poorer workability. (author).
Purpose - The purpose of this paper is to help library technology staff understand the process of beta testing software, determine if it is appropriate for them to engage in the process, and provide suggestions on how to the time invested in the process. Design/methodology/approach - The paper explains what beta testing is, why it should be used and how to become a beta tester. Findings - The paper reveals that beta testing is not convenient for everyone, but those taking place in these activities should be thorough, positive and generous in order to maximize the return on investment in this kind of testing. Practical Implications - While beta testing new software features can take a significant amount of time, the resulting benefits of early access to new features and improved vendor-staf...
Strain embrittlement in Ti base alloys during tensile testing was investigated. Results show that in an #alpha#-#beta# titanium alloy the local activity of H in alpha phase (#alpha#/sub H//sup #alpha#) increases and activity of H in beta phase (#alpha#/sub H//sup #beta#) decreases as the equiaxed #alpha# particle size decreases at constant volume fraction of phases. Thus with decreasing particle size there would be a tendency for H to move from #alpha# to #beta#, decreasing the H content of #alpha#. Also whether H tended to move from #beta# to #alpha# or from #alpha# interiors to the #alpha#-#beta# interface this tendency would be reduced by surface tension effects, making the alloy less susceptible to embrittlement.
To study #beta# #reversible# #omega#-transformation in pseudo-#beta#-titanium alloy VT30, doped by hydrogen, methods of X-ray diffraction and thermodifferential analyses are used. It is established that in the process of heating of the hardened alloy from 0.004-0.1% H first formation and then dissolution of #omega# phase take place. An increase in hydrogen content to 0.1% decreases thermal effect of the processes and does not affect the temperature of #beta# #reversible# #omega#-transformation. Introduction of hydrogen in the concentration of 0.2% and higher suppresses completely #beta# #reversible# #omega# - transformation. A decrease in heating rate displaces #beta# #reversible# #omega#-transformation to lower temperatures.
Starting from the original collective Hamiltonian of Bohr and separating the beta and gamma variables as in the X(5) model of Iachello, an exactly soluble model corresponding to a harmonic oscillator potential in the beta-variable (to be called X(5)-$\\beta^2$) is constructed. Furthermore, it is proved that the potentials of the form $\\beta^{2n}$ (with n being integer) provide a ``bridge'' between this new X(5)-$\\beta^2$ model (occuring for n=1) and the X(5) model (corresponding to an infinite well potential in the beta-variable, materialized for n going to infinity. Parameter-free (up to overall scale factors) predictions for spectra and B(E2) transition rates are given for the potentials $\\beta^2$, $\\beta^4$, $\\beta^6$, $\\beta^8$, corresponding to E(4)/E(2) ratios of ...
Partially purified UDPgalactosyltransferase (EC 2.4.1.22) from bovine milk has been used to synthesize millimolar amounts of compounds such as Gal#beta#(1#->#4)Glc, Gal#beta#(1#->#4)GlcNAc-#beta#-hexanolamine, and Gal#beta#(1#->#4)-GlcNAc#beta#(1#->#4)GlcNAc. The same method has been used to prepare similar compounds containing "1"3C-enriched galactopyranosyl moieties. Gal#beta#(1#->#4)GlcNAc-#beta#-hexanolamine was also synthesized in a solid-phase system in which the GlcNAc-#beta#-hexanolamine glycoside was covalently linked to agarose beads. At pH 7.0 and at 1 to 5 mM Mn"2"+"+ the yields of the galactosyl saccharides are greater than 90% by using 10% excess of UDPGal donor. The use of a 90% enriched [1-"1"3C]galactosyl residue allowed the determination of the most abundant conformer about the ...
The methods of optical and transmission electron microscopy were used to study the influence of different programmes of hot deformation on the structure formation of (#alpha#+#beta#) titanium alloy VT9. The #beta# alloy VT-15 was studied at the same time in order to simulate the dislocation structure generated in the process of hot deformation. During the hot deformation of two-phase titanium alloys in both #beta# and (#alpha#+#beta#) ranges there is found to be an optimum range of deformation in which a homogeneous, polygonized structure is formed.
Carbohydrate and nucleotide structural determination using modern spectroscopic techniques is dependent on our ability to label oligonucleotides and oligosaccharides with stable isotopes. Uniform Carbon 13 and Nitrogen 15 labeling of oligonucleotides is important to present-day efforts, which are focused on determining the structure of relatively small oligosaccharides and oligonucleotides, which form the elements of larger structures. Because of the relatively recent interest in three-dimensional structure, the development of techniques used to label them has lagged behind parallel techniques used to label peptides and proteins. Therefore, this group`s discussion focused primarily on problems faced today in obtaining oligonucleotides labeled uniformly with carbon 13 and nitrogen 15.
W have introduced template-synthesized metal phosphate nanoparticle labels for electrochemical immunoassay. Such use of an apoferritin template offers a simple and convenient route to prepare metallic nanoparticle labels for electrochemical immunoassays and avoid the complicated and time-consuming nanoparticle synthesis process (QD synthesis). Releasing metal ions from metal phosphate in an acetate buffer (pH 4.6) eliminates the harsh condition in the traditional metallic nanoparticle dissolution (e.g., strong acid dissolution of QDs and gold nanoparticles). This method is ultrasensitive and its DL is low to 77fM. The simultaneous detection of multiple protein targets is easily performed by using different metal phosphate nanoparticle labels (cadmium phosphate and lead phosphate). This approach can be extended to prepare multiple metal (such as zinc, lead, cadmium, copper, indium, gold, silver) phosphate nanoparticle ...
The purpose was to identify human in vitro cell lines with a high relative cellular sensitivity to fast neutrons as compared to photons and to examine their relationship to intrinsic photon radiosensitivity and cellular proliferation kinetics. The clonogenic cell survival following exposure to low LET, 4 MeV photons or, high LET, 62.5 MeV (p #-># Be"+) fast neutrons and the cell survival following exposure to low LET, 4 MeV photons or, high LET, 62.5 MeV (p #-># Be"+) fast neutrons and the cell kinetic parameters of 30 human in vitro cell lines, covering a wide range of histologies, were analyzed alone and with previously published data of Fertil and Malaise. The relative survival at 1.6 Gy of neutrons (SF_1_._6) compared to 2 Gy of photons (SF_2) and the cell kinetic parameters of the 30 cell lines were also compared. The relative lethality of 62.5 MeV fast neutrons was assessed by comparing the ratio #alpha# neutrons/#alpha# photons or SF_1_._6 neutrons/SF_2 photons to SF_2 ...
The effects of D-amino acids at Asp"2"3 and Ser"2"6 residues on the conformational preference of #beta#-amyloid (A#beta#) peptide fragment (A#beta#_2_0_-_2_9) have been studied using different spectroscopic techniques, namely vibrational circular dichroism (VCD), vibrational absorption, and electronic circular dichroism. To study the structure of the A#beta#_2_0_-_2_9, [D-Asp"2"3]A#beta#_2_0_-_2_9, and [D-Ser"2"6]A#beta#_2_0_-_2_9 peptides under different conditions, the spectra were measured in 10 mM acetate buffer (pH 3) and in 2,2,2-trifluoroethanol (TFE). The spectroscopic results indicated that at pH 3, A#beta#_2_0_-_2_9 peptide takes random coil with #beta#-turn structure, while [D-Ser"2"6]A#beta#_2_0_-_2_9 peptide adopts significant amount of polyproline II (PPII) type structure along with ...
The #beta#-CEZ alloy : Ti-5%Al-2%Sn-4%Zr-4%Mo-2%Cr-1%Fe is a near #beta# titanium alloy. Since its processing routes include heat treatment (consisting of solution treatment and ageing), it has been decided to study the influence of the #beta# phase stability on #alpha# phase precipitation and hardening kinetics. Small sized specimens, coming from industrial heats, have been heat treated above and below the #beta# transus, and then water quenched. Therefore, several degree of #beta# stability are obtained. When it is increased (i.e. the solution treatment temperature is lowered), #alpha# or #omega# phases precipitations are delayed, as well as the hardening phenomena. Moreover, the #omega# stability domain is reduced. The mechanisms of #alpha# or #omega# precipitation are discussed, and related to the hardening kinetics. (orig.).
Phase transformations from #alpha#- to #beta#-SiAlONs (i.e., from #alpha#' to #beta#') have been recently reported in a number of rare-earth SiAlON systems during postsintering heat treatment. In the present work, this transformation process in a Sm (#alpha# + #beta#)-SiAlON material is studied by using XRD, TEM, and EDS X-ray mapping techniques. It is observed that in addition to the formation of #beta#' and M' phases, the #alpha#'-to-#beta#' transformation is accompanied by a significant increase in the amount of an AlN-polytypoid phase. The results suggest that some #alpha#' phases are thermodynamically unstable at temperatures lower than the material sintering temperature and will decompose when conditions allow. For the composition studied in this work, the #alpha#-SiAlON decomposition can be described in general as #alpha#' #-># #beta#' + M' + AlN ...
The phytochemical investigation of Chomelia obtusa leaves led to the isolation of four triterpenes (3-O-#beta#-D-quinovopyranosyl-28-O-#beta#-D-glycopyranosyl quinovic acid, 3-O-#beta#-D-quinovopyranosyl-28-O-#beta#-D-glycopyranosyl cincholic acid, and a mixture of ursolic and oleanolic acids), two flavonoids (3-O-#beta#-D-glycopyranosyl quercetin, 3-O-[#alpha#-L-rhamnopyranosyl-(1#->#6)-#beta#-D-galactopyranoside] quercetin), besides bornesitol and a mixture of 3,5- and 4,5-O-dicaffeoyl quinic acids. The structures of the isolated compounds were assigned on the basis of spectroscopic data, including two-dimensional NMR methods. The anti-inflammatory and antioxidant activities of the crude methanolic extract and of its fractions were evaluated. This is the first report on the chemical and biological investigation of the Chomelia genus. (author)
Stemming from their unique combination of elevated strength, low density, and good overall corrosion resistance, beta titanium alloys have become attractive candidate materials for critical, high-stress, components in corrosive services. An overview of the comparative corrosion resistance of beta alloys to conventional alpha and alpha/beta titanium alloys in common industrial and aerospace service environments generally reveals attractive behavior depending on the environment and alloy composition and, in some cases, alloy condition. Expanded performance windows are especially noted for the molybdenum-rich beta alloys, particularly in regard to resisting reducing acids, stress corrosion, and high temperature localized chloride attack, along with hydrogen and oxidation resistance. Where applicable, implications of this enhanced corrosion performance on current and perspective beta ...
Intact rat fat cell exposed to 12.5 ..mu..M (..gamma..-32P)ATP incorporate label into specific proteins within minutes. By solubilizing the reaction mixture with SDS which bypasses the subcellular fractionation steps, the labeled proteins can be identified in autoradiographs of SDS-PAGE gels. The most prominently labeled protein has an M/sub r/ of 42,000. Localization of this component to the cell surface can be made on the basis of inhibition of phosphorylation by addition of a protein derived from the rat brain with protein kinase inhibitory property, susceptibility of the phosphorylated protein to the tryptic digestion, inhibition of phosphorylation of this protein after brief exposure to melittin. To rule out the possibility that the cell surface protein might be a mitochondrial contaminant from broken cells, /sup 32/Pi-labeled and (..gamma..-/sup 32/P)ATP-labeled cells were ...
Mutations in transcription factors hepatocyte nuclear factors (HNF)-1#alpha# and HNF-1#beta# cause maturity-onset diabetes of the young (MODY) types 3 and 5, respectively. HNF-1#alpha# and HNF-1#beta# mutations are well studied in some tissues, but the mechanism by which HNF-1#alpha# and HNF-1#beta# mutations affect sucrase-isomaltase (SI) transcription in the small intestine is unclear. We studied the effects of 13 HNF-1#alpha# mutants and 2 HNF-1#beta# mutants on human SI gene transcription, which were identified in subjects with MODY3 and MODY5, respectively. Transactivation activity of 11 HNF-1#alpha# and 2 HNF-1#beta# mutants was significantly lower than that of wild (wt)-HNF-1#alpha# and wt-HNF-1#beta#. Furthermore, in co-expression studies with mutant (mu)-HNF-1#alpha#/ wt-HNF-1#beta# and ...
A photoaffinity derivative of the local anesthetic trimethisoquin, 5-azido-["3H]trimethisoquin (5-A["3H]T) labelled bands of app. mol. wt 50 k and 66 k. To explain the rather paradoxical labelling by 5-A["3H]T of two polypeptide chains instead of one, three possibilities were considered: (i) The site for non-competititve blockers is not carried by the 50 k or 66 k chain; however, these chains lie in the vicinity of the binding site and become preferentially labelled since they present chemical groups with which the nitrene group of 5-A["3H]T reacts. (ii) The 50 k and 66 k chains are different but carry binding sites for non-competitive blockers with similar reactivities. (iii) The 50 k chain labelled by 5-A["3H]T derives from the 66 k chain by proteolysis. These results show that the third alternative is the correct one. Under conditions which limit proteolysis, 5-A["3H]T selectively ...
To study the topographical organization of mu and beta band event-related desynchronization (ERD) associated with voluntary hand and foot movements, we used magnetoencephalographic (MEG) recordings...Full Text Available
The present study has examined for #alpha#/#beta#-Ti alloys the relationship between the morphology and crystallography of Widmanstaetten plates of #alpha#-Ti in colonies within a prior grain of #beta#-Ti. Thus, optical metallography, scanning electron microscopy and transmission electron microscopy have been used to characterize the morphological features of the microstructure, whereas orientation-imaging microscopy (OM) and transmission electron microscopy (TEM) have been employed to reveal crystallographic information. It has been discovered that within a prior #beta#-Ti grain, although the growth direction of the Widmanstaetten plates in given colonies may differ by large angles from #alpha#-plates in other colonies, they may exhibit very close crystallographic relationships. For example, inclined #alpha#-plates may share common basal planes and be related by a rotation of #approx#10.5 deg. about the c-axis of the ...
The composition of carotenoids, along with anthocyanins and chlorophyll, accounts for the distinctive range of colour found in the Actinidia (kiwifruit) species. Lutein and beta-carotene...Full Text Available
Purified beta-toxin from Clostridium perfringens type C was found to be a single polypeptide chain protein with a molecular weight of approximately 30,000. The toxin was heat labile, with 75% of its...Full Text Available
Beta silicon carbide is an excellent candidate semiconductor material for demanding applications in high power and high temperature electronic devices due to its high breakdown voltage, relatively large band gap, high thermal conductivity and high melting...
Probabilistic sensitivities using the score function method are developed for a lifing analysis of an alpha + beta titanium alloy in a round bar under axial fatigue load. Sensitivities with respect to the statistical inputs of the crack initiation size (a...
We investigated the extended-spectrum beta lactamases among 62 Salmonella enterica Typhimurium isolates recovered from children with diarrhea in a Chinese pediatric hospital. A large...Full Text Available
Synthesis genes encoding the human #alpha#- and #beta#-globin polypeptides have been expressed from a single operon in Escherichia coli. The #alpha#- and #beta#-globin polypeptides associate into soluble tetramers, incorporate heme, and accumulate to >5% of the total cellular protein. Purified recombinant hemoglobin has the correct stoichiometry of #alpha#- and #beta#-globin chains and contains a full complement of heme. Each globin chain also contains an additional methionine as an extension to the amino terminus. The recombinant hemoglobin has a C_4 reversed-phase HPLC profile essentially identical to that of human hemoglobin A_0 and comigrates with hemoglobin A_0 on SDS/PAGE. The visible spectrum and oxygen affinity are similar to that of native human hemoglobin A_0. The authors have also expressed the #alpha#- and #beta#-globin genes separately and found that the expression of the #alpha#-globin ...
Experimental, relative intensities for the components of L X-ray were collected from literature, and atomic-number dependency of L#beta#/L#alpha# has been found. (author).
Extended-spectrum beta-lactamases (ESBL) constitute a key antibiotic-resistance mechanism affecting Gram-negative bacteria, and also an excellent model for studying evolution in real time. A shift in...Full Text Available
Measurement of intrathylakoid aqueous volumes by electron spin resonance spectroscopy was used to study ionic permeability properties of thylakoid membranes isolated from Beta vulgaris...Full Text Available
IntroductionChest pain with ST-segment elevation is a rare clinical problem during dobutamine stress testing. Although beta-agonists treatment prior to dobutamine stress testing...Full Text Available
Quantitative metallography is often used to confirm the proper processing of aerospace metallic materials. A microstructural feature of great importance for titanium alloys processed in the alpha-beta phase field is the volume fraction of primary alpha. S...
The in vitro antibacterial activities of the newly developed 7 alpha-methoxy cephalosporins and 7 beta-methoxyiminoacetamido cephalosporins against 67 clinical isolates of Bacteroides fragilis and their...Full Text Available
1. The effect on rat liver peroxisomal beta-oxidation of feeding diets containing various amounts of dietary oils was investigated. With increasing amounts (5-25%, w/w) of soya-bean oil an apparent,...Full Text Available
beta-Endorphin-like immunoreactivity in human ventricular cerebrospinal fluid was measured with a specific radioimmunoassay. The subjects were undergoing a surgical procedure for relief of chronic intractable...Full Text Available
Human IgG specific for beta-endorphin was identified by enzyme-linked immunoabsorbent assay and isolated by affinity chromatography. From a sample of 27 subjects, three individuals with major depression...Full Text Available
This paper introduces briefly neutrinoless Double Beta Decay and discusses its implications for neutrino physics. After a presentation of general experimental concepts, such as the various proposed methodological approaches and the sensitivity, the current experimental situation is concisely reviewed.
A procedure for high level tritium labelling at the C2-H position of adenosine 5`-triphosphate ([2-{sup 3}H]-ATP, 1), based on the tritiodehalogenation reaction of 2-bromoadenosine 5`-triphosphate (2) has been elaborated. This precursor was prepared in a six-step synthesis from guanosine. The tritiodehalogenation of (2) for three hours over palladium oxide in phosphate buffer yielded tritium labelled ATP with high specific activity, in good chemical yield. (author).
Four /sup 125/I labeled mono- and diamines were prepared and evaluated as potential brain-imaging agents. The diamines are analogues of the previously reported /sup 75/Se labeled diamines, which show high brain uptake and retention. All of the radioiodinated amines display high initial brain uptake in rats after intravenous injection (1.7-2.4% dose/organ). The xylylenediamines show prolonged brain retention (t1/2 approximately 18 h), which is desirable for brain imaging. In contrast, the benzylamine is rapidly cleared from brain tissue (t1/2 approximately 15 min).
Scientists at JPL have developed chemical and biological techniques using microspheres filled with drugs, electron-opaque metals, or radioactive, fluorescent, magnetic or electrically charged materials to label specific groups of cells. Synthetic polymeric microspheres are coupled with specific antibodies to form reagents called immunomicrospheres, which can seek out and attach themselves to any specific group of cells. These cell-labeling techniques, therefore, open new avenues not only to the basic study of cells but also to the diagnosis and treatment of many diseases, including cancer.
The schematic model is extended to open-shell nuclei. The quasiparticle random-phase approximation plus core polarization are used to calculate multipole matrix elements M/sub n/ and M/sub p/. Calculated trends in the ratio of deformation parameters ..beta../sub n//..beta../sub p/ are compared with experimental ratios for several sets of isotopes and isotones. The systematics indicate a rather abrupt change toward equality of ..beta../sub n/ and ..beta../sub p/ when N or Z is changed from a closed-shell value.
Photosynthetic carbohydrates from the leaves are exported through the phloem to growing tips, roots, flowers and fruits. If sucrose labelled with {sup 14}C is applied to the leaves of bean plants, the pathway for sugar movement may be readily observed by autoradiography. Students apply the labelled sucrose during class time and return the next day to press their plants. During the next class, the pressed and dried plants are placed against X-ray film and left in the dark for four weeks. the film is then developed, examined for presence of label and compared to the pressed plants. Source to sink movement is clearly illustrated and information about the mechanism of phloem transport and loading is gained through experimental treatments, which include blocking the phloem pathway and inhibiting energy production.
The binding of iodine-labelled plasminogen to Helicobacter pylori CCUG 17874 was characterized. Inhibition of the binding was observed after preincubation of H. pylori...Full Text Available
The known biological functions of RNA have expanded in recent years and now include gene regulation, maintenance of sub-cellular structure, and catalysis, in addition to propagation of genetic information. As for proteins, RNA function is tightly correlated with structure. Unlike proteins, structural information for larger, biologically functional RNAs is relatively limited. NMR signal degeneracy, relaxation problems, and a paucity of long-range {sup 1}H-{sup 1}H dipolar contacts have limited the utility of traditional NMR approaches. Selective isotope labeling, including nucleotide-specific and segmental labeling strategies, may provide the best opportunities for obtaining structural information by NMR. Here we review methods that have been developed for preparing and purifying isotopically labeled RNAs, as well as NMR strategies that have been employed for signal assignment and structure determination.
The human erythrocyte (RBC) Rh blood group system consists of a complex of distinct integral membrane polypeptides with physical properties common to the aminophospholipid transporter responsible for the transbilayer movement of phosphatidylserine (PS) in RBC. To assess the involvement of Rh polypeptides in PS translocation, the aminophospholipid translocase was labeled with a photoactivatable PS analogue, "1"2"5I-azido-PS, and with an inhibitor of PS transport, "1"2"5I-labeled 2-(2-pyridyldithio)ethylamine. The ability of monoclonal Rh antibodies to immunoprecipitate the labeled transporter was determined. Immunoprecipitated Rh polypeptides were found to be labeled with the aminophospholipid translocase markers, suggesting that Rh proteins are involved in the transbilayer movement of PS.
Additional measurements have been made of deposition and retention of inhaled radioactively labeled iron oxide aerosols generated by a spinning top aerosol generator.
... radiation during clinical therapy and exposures due to radiation accidents or attacks, in which the doses are uncontrolled ... only be used off-label in victims of radiation accidents or attacks. The idea...
The TTT diagrams describing the beta to alpha isothermal transformation have been made by isothermal dilatometry for pure uranium and 21 alloys based on chromium, silicon, molybdenum, iron, aluminium, zirconium. The thermal cycle preceeding the isothermal...
The effect of solution treatment temperature and oxygen content on the microstructure and age hardening response of the metastable beta alloy Ti-11.5Mo-6Zr-4.5Sn have been studied. Kinetics of formation of the equilibrium alpha-phase and the metastable om...
The alloy of Ti-Al-Mo-V-Cr system is studied for its structure in a strained state and specific features of #beta#-#alpha# transformation in a #beta#-matrix and deformation twins on ageing. It is determined that preliminary deformation initiates the decomposition of solid solution on aging. In a metastable #beta#-titanium alloy the substructure of deformation twins is shown to vary essentially with aluminium and chromium partial substitution for molybdenum and vanadium
Bridged monobactam {beta}-lactamase inhibitors were prepared and evaluated as potential partners for combination with imipenem to overcome class C {beta}-lactamase mediated resistance. The (S)-azepine analog 2 was found to be effective in both in vitro and in vivo assays and was selected for preclinical development.
We have previously described an allelic polymorphism in the V beta 6.1 T-cell receptor gene. The V beta 6.1B allele is associated with disease in a subgroup of patients with juvenile rheumatoid arthritis....Full Text Available
Beta C trademark, a metastable beta titanium alloy developed by RMI Titanium Company, continues to be used in new applications due to its excellent mechanical properties and resistance to corrosion. New data in this paper include mechanical properties in large sections, cold drawn bar and welds. Fatigue crack growth and corrosion data are added to supplement previously published data.
The influence of structure on mechanical properties in the course of tensile tests in a wide range of temperatures was studied, using the VT16 structure thermally strengthened (alpha+beta)-titanium alloy by way of example. It is ascertained that transition from ductile to brittle fracture at the temperature of -196 deg C is observed only in coarse-grain alloy having alpha-eldging of beta grains.
Dissipation of energy of #beta#"--radiation in polyvinylchloride (PVC) was analyzed. Change of PVC properties at irradiation by beta beams with energy 2,32 MeV was characterized using potentials of inter- and intramolecular interactions as well as Born potential. Correlation between some micro- and macroproperties of PVC was detected and ways of their controlled correction were proposed. (authors)
The relationships of hydrogen alloyed #beta#-titanium alloy deformation behaviour to its microstructure and texture are investigated. It is shown that plasticity increases and strain induced texture changes at low hydrogen contents (0.1-0.2 mass %). Possible mechanisms responsible for specific features of #beta#-Ti alloy deformation are discussed. The study is made using alloy VT35 doped with hydrogen
We have isolated the human prointerleukin 1 (proIL-1) beta gene from leukocyte and fetal liver libraries. The nucleotide sequence and its gene organization reveals that the proIL-1 beta gene is composed...Full Text Available
Synthesis of O'/#beta#' SiAlON composites was studied. As starting materials, Si_3N_4, Al_2O_3 and SiO_2 powders were used. Pressureless sintering was applied as consolidation technique and was performed at 1400-1700 C. Densification and reaction taking place during sintering were followed. Microstructure of O'/#beta#' composites is discussed. It was found that without additives liquid phase amount formed within the samples was below critically needed for full densification, but promoted reaction of O' and #beta#' formation. Using yttria as additive densification was enhanced. O'/#beta#' ratio decreased while H_V and K_I_c increased with increasing amount of additive. (orig.).
Superplasticity in Ti alloys has been widely investigated in the past and superplastic forming of aerospace components has thus been developed over the last two decades. The Ti alloy most studied in this framework is undoubtedly the Ti-6Al-4V (wt %) alloy, for which maximum elongations are obtained in the temperature range [880-900C]. The development of the superplastic properties has been demonstrated to be in close relation with quite similar volume fractions of the #alpha# and #beta# phases, the #beta# transus temperature for this alloy ranging from 980-1000 C. Attempts have been carried out to reduce the temperature of superplastic forming of Ti-6Al-4V by the addition of elements like Fe, Co, or Ni. Such an introduction of alloying elements indeed results in a decrease of the optimum forming temperature to values as low as 820 C. This decrease is mainly attributed to a change in the phase volume fractions according to thermodynamic ...
We solve the loop equations of the $\\beta$-ensemble model analogously to the solution found for the Hermitian matrices $\\beta=1$. For \\beta=1$, the solution was expressed using the algebraic spectral curve of equation $y^2=U(x)$. For arbitrary $\\beta$, the spectral curve converts into a Schr\\"odinger equation $((\\hbar\\partial)^2-U(x))\\psi(x)=0$ with $\\hbar\\propto (\\sqrt\\beta-1/\\sqrt\\beta)/N$. This paper is similar to the sister paper~I, in particular, all the main ingredients specific for the algebraic solution of the problem remain the same, but here we present the second approach to finding a solution of loop equations using sectorwise definition of resolvents. Being technically more involved, it allows defining consistently the B-cycle structure of the obtained quantum algebraic curve (a D-module of the form $y^2-U(x)$, where $[y,x]=\\hbar$) and ...
The carbothermal reduction of clay minerals in a nitrogen atmosphere is a well established method for producing #beta#'-sialon. There has been some debate within the literature concerning the role that Fe plays in the formation of the #beta#'-sialon phase. However, most workers accept that Fe is able to either catalyze or promote the formation of #beta#'-sialon although some workers have indicated that the function of the Fe is controlled by gas flow rate and there is evidence that Fe also promotes formation of additional phases. The aim of the present study was to characterize the behaviour of Fe within the #beta#'-sialon synthesis. "5"7Fe Moessbauer spectroscopy was employed for the study because this technique is specific to Fe and does not suffer interference from other elements. Moreover, both the coordination and oxidation state and the relative abundances of the various Fe-containing phases are ...
An alloy of composition Ti-4.4 wt.% Ta-1.9 wt.% Nb is being developed as a structural material for corrosion applications, as titanium and its alloys possess excellent corrosion resistance in many oxidizing media. The primary physical metallurgy database for the Ti-4.4 wt.% Ta-1.9 wt.% Nb alloy is being presented for the first time. Determination of the #beta# transus, M_s temperature and classification of the alloy have been carried out, employing a variety of microscopy techniques, X-ray diffraction (XRD), micro-hardness and differential scanning calorimetry (DSC). The #beta# transition temperature or #beta# transus determined using different experimental techniques was found to agree very well with evaluations based on empirical calculations. Based on chemistry and observed room temperature microstructure, the alloy has been classified as an #alpha# + #beta# titanium alloy. The high temperature ...
Previous behavioral and pharmacological studies have implicated endorphins in radiation-induced locomotor hyperactivity of the C57BL/6J mouse. However, the endogenous opiate(s) responsible for this behavioral change have not been identified. The present study measured beta-endorphin-like immunoreactivity (beta-END-LI) in brain, blood, and combined brain and pituitary samples from irradiated and sham-irradiated C57BL/6J mice. After radiation exposure, levels of beta-END-LI decreased significantly in the brain. A similar, but not statistically significant, decline was measured in combined brain and pituitary samples. Concentrations of blood beta-END-LI were not changed by irradiation. These radiogenic changes in beta-END-LI are in some ways similar to those observed after other stresses. However, radiation-induced locomotor hyperactivity may be mediated more by alterations of ...
Let $M$ be a complex manifold of complex dimension $n+k$. We say that the functions $u_1,...s,u_k$ and the vector fields $\\xi_1,...,\\xi_k$ on $M$ form a \\emph{complex gradient system} if $\\xi_1,...,\\xi_k,J\\xi_1,...,J\\xi_k$ are linearly independent at each point $p\\in M$ and generate an integrable distribution of $TM$ of dimension $2k$ and $du_\\alpha(\\xi_\\beta)=0$, $\\d^c\\u_\\alpha(\\xi_\\beta)=\\delta_{\\alpha\\beta}$ for $\\alpha,\\beta=1,...,k$. We prove a Cauchy theorem for such complex gradient systems with initial data along a $\\CR-$submanifold of type $(\\CRdim,\\CRcodim)$. We also give a complete local characterization for the complex gradient systems which are \\emph{holomorphic} and \\emph{abelian}, which means that the vector fields $\\xi_\\alpha^c=\\xi_\\alpha-J\\xi_\\beta$, $\\alpha=1,...,k$ are holomorphic and satisfy $[\\xi_alpha^c,\\bar{\\xi_\\beta^c}]=0$ ...
A microwave-assisted carbothermal reduction and nitridation (CTR/N) method has been used for successful preparation of monophasic #beta#'-SiAlON starting from kaolinite and carbon black. Phase pure #beta#'-SiAlON has been obtained in under 60 min in microwave field. The z value of microwave prepared #beta#'-SiAlON is found to be 2.95, which is very close to the expected value from kaolinite composition. Formation of #beta#'-SiAlON has been monitored with XRD and MASNMR of "2"9Si and "2"7Al; the possible reaction mechanism has been discussed. Kaolinite to #beta#'-SiAlON conversion appears to be a very rapid single-step reaction under microwave irradiation. #beta#'-SiAlON powders have been microwave sintered to 98.7% of theoretical density in 30 min.
The effect of abatacept, a selective T-cell co-stimulation modulator, on vaccination has not been previously investigated. In this open-label, single-dose, randomized, parallel-group, controlled study,...Full Text Available
Synthesis of the azido substituted non-steroidal anti-inflammatory drug 2-(2,6-dichloroanilino)phenylacetic acid and isotope labeling of this compound have been performed and are described. Initial evaluation of the binding ability and photoreactivity indicates that this compound has potential for photoaffinity labeling as well as enzyme selectivity studies. (author).
The authors have used limited proteolysis of affinity-labeled estrogen receptors (ER), coupled with antireceptor antibody immunoreactivity, to assess structural features of ER and the relatedness of ER from MCF-7 human breast cancer and rat uterine cells. MCF-7 ER preparations covalently labeled with ["3H]tamoxifen aziridine (["3H]TAZ) were treated with trypsin (T), #alpha#-chymotrypsin (C), or Staphylococcus aureus V8 protease prior to electrophoresis on sodium dodecyl sulfate gels. Fluorography revealed a distinctive ladder of ER fragments containing TAZ for each protease generated from the M/sub r/ 66,000 ER. Immunoblot detection with the primate-specific antibody D75P3#gamma# revealed that all immunoreactive fragments corresponded to TAZ-labeled fragments but that some small TAZ-labeled fragments were no longer immunoreactive. In contrast, use of the antibody H222SP#gamma# revealed a correspondence ...
We present evidence that the role of tryptophan and other potential intermediates in the pathways that could lead to indole derivatives needs to be reexamined. Two lines of Lemna gibba...Full Text Available
This case report demonstrates an hepatic amebic abscess by scintigrapy, utilizing a new radiopharmaceutical designed specifically for that purpose. The abscess is delineated as a positive lesion after twenty four hours. The agent, "1"3"1I-labeled bromometronidazole, may prove to be specific for the diagnosis of these abscesses. (orig.).
The rate of appearance of labeled thyroxine (T4) and albumin in lymph from various areas after simultaneous i.v. injection of the labeled substances in conscious ambulatory sheep has been used to estimate...Full Text Available
...) Abstract: Fluorescence microscopic imaging is widely used in biomedical research to study molecular and cellular processes in cell culture or tissue samples. This is motivated by the high inherent sensitivity of fluorescence techniques, the spatial resolution that compares favorably with cellular dimensions, the stability of the fluorescent labels used and the sophisticated strategies that have been developed for selectively labeling target molecules. More recently, two and ...
33 patients with advanced malignant melanoma were studied after intravenous administration of 131I-labeled Fab fragments specific for p97, an oncofetal glycoprotein of human melanoma. In all, 47 gamma...Full Text Available
HIPDM is an "1"2"3I-labeled agent with a distribution in brain reflecting regional perfusion. This compound is neutral and lipid soluble at blood pH and freely crosses the blood-brain barrier. At the lower pH in brain, it picks up a hydrogen ion and becomes positively charged. In this form the molecule is not lipid soluble and it is trapped in brain.
A method is described to smear extremely thin layers of nuclear emulsion on labeled electron microscope preparations and to measure the thicknesses of these layers, Without further separation, preparation and emulsion can be observed after exposure and development in an electron microscope. The source of the tracks formed in the emulsion can be exactly identified and the size and structure determined. This method finds applications in dust research and also in the analysis of medical and biological sections. Further information can be obtained about properties of different emulsions. (auth)
The obtained results in presently study demonstrate that the feasibility of the detection of the sentry ganglion in cervix uterine cancer using a boarding by laparoscopic via, being necessary the use of twice labelled as much with patent blue and radioisotope (colloid of labelled rhenium with "9"9"mTc, total dose of 3 MCi) to achieve the identification of the ganglion. (Author)
High liver uptake and slow body clearance presently limit the usefulness of "1"1"1In labeled antibodies for tumor imaging. We have investigated "2"0"3Pb as an alternate and better antibody label. The DTPA and cyclohexyl EDTA (CDTA) conjugates of an anticolon carcinoma antibody, 17-1A were labeled (bicyclic anhydride method) with "2"0"3Pb and "1"1"1In with 60 and 90% labeling yields, respectively. The biodistribution of "2"0"3Pb-17-1A conjugates was compared with the corresponding "1"1"1In-labeled preparations and with "2"0"3Pb-DTPA, "2"0"3Pb-nitrate and nonrelevant antibody controls in normal and human tumor (SW948) xenografted nude mice at 24, and 96 hr. Lead-203-labeled CDTA and DTPA antibody conjugates gave similar in vivo distributions. Even though the lead bound to these chelate-antibody conjugates was more labile in serum and in vivo, compared to indium, ...
Radioimmunoassays for detecting cell-associated or released virus are described using either 125I- or [3H]acetate-labeled antibodies. In the first assay system, antigen-antibody...Full Text Available
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
Research is described in the development of organometallic reagents in which the boron was attached to a nonreactive organic or inorganic matrix such as polystyrene, silica, or alumina. We developed the synthesis of oxygen-15 labelled butanol, which has been found to be a valuable blood flow agent in humans. We have also developed a series of polymeric borane derivatives which were used to prepare nitrogen-13 labelled amines.
A simple procedure is described for preparing {sup 125}I-labelling hyluronan of high molecular weight. The reducing terminal group of hyaluronic acid was derivatized with tyramine through the formation of a Schiff base which was subsequently reduced with sodium cyanoborohydride. By radioiodination of the aromatic ring, {sup 125}I-labelled hyaluronic acid was obtained in high yield (40%) and high specific activity, 555 GBq/mmol (15 Ci/mmol). (Author).
Ribosomal protein L 10 from the livers of trout, hen, and rat was found to be the main target for 2-nitro-4-azidobenzoyl-Phe-tRNA in affinity labelling experiments. Therefore, despite somewhat different electrophoretic mobilities, this protein seems to be involved in the organization of the peptidyl transferase centre in ribosomes of various vertebrates. (author).
Two methods were used to label pig kidney microvillar membrane proteins from the luminal and cytoplasmic surfaces of closed membrane vesicles. The first method was lactoperoxidase-catalysed radioiodination. Lactoperoxidase and glucose oxidase were positioned inside or outside the vesicles, iodination being initiated by adding glucose and "1"2"5I. After electrophoresis of the proteins, asymmetric labelling patterns on radioautographs were observed. However the major disadvantage of this method was the high degree of intramembrane labelling of the fatty acid chains of membrane lipids. The second method overcame this disadvantage. A new hydophilic photoreagent, 3,5-di("1"2"5I)iodo-4-azidobenzenesulphonate, was transported by a Na"+-dependent system into microvillar vesicles, thus permitting labelling from either side of the membrane when the vesicles were photolysed. The activity of several microvillar ...
Cell extracts of the thermophile Clostridium thermohydrosulfuricum catalyzed the phosphorylation by (..gamma..-/sup 32/P)ATP of several endogenous proteins with M/sub r/s between 13,000 and 100,000. Serine and tyrosine were the main acceptors. Distinct substrate proteins were found in the soluble (e.g., proteins p66, p63, and p53 of M/sub r/s 66,000, 63,000, and 53,000, respectively) and particulate (p76 and p30) fractions, both of which contained protein kinase and phosphatase activity. The soluble fraction suppressed the phosphorylation of particulate proteins and contained a protein kinase inhibitor. Phosphorylation of p53 was promoted by 10..mu..M fructose 1,6-bisphosphate or glucose 1,6-bisphosphate and suppressed by hexose monophosphates, whereas p30 and p13 were suppressed by 5 ..mu..M brain (but not spinach) calmodulin. Polyamines, including the odd polyamines characteristic of thermophiles, modulated the labeling of most of the phosphoproteins. Apart from ...
The time of appearance of newly synthesized rRNAs and ribosomal proteins (r-proteins) in the ribosomes of pea cotyledons (Pisum sativum L.) during germination was investigated. The ribosomal fraction was isolated and analyzed according to the method of germination of the embryo in the presence of labeled precursors or after pulse labeling of the embryos at different stages of germination. For the identification of newly synthesized rRNAs in the ribosomes we estimated the relative stability of labeled RNAs to the action of RNase, the sedimentation rate, the ability to be methylated in vivo in the presence of (/sup 14/C)CH/sub 3/-methionine, and the localization in the subunits of dissociated ribosomes. The presence of newly synthesized r-proteins in the ribosomes was judged on the basis of the electrophoretic similarity in SDS-disc electrophoresis of labeled polypeptides of purified ribosome preparations ...
The heavy chains of Acanthamoeba myosins, IA, IB and II, turkey gizzard myosin, and rabbit skeletal muscle myosin subfragment-1 were specifically labeled by radioactive ATP, ADP, and UTP, each of which is a substrate or product of myosin ATPase activity, when irradiated with uv light at 0"0C. With UTP, as much as 0.45 mol/mol of Acanthamoeba myosin IA heavy chain and 1 mol/mol of turkey gizzard myosin heavy chain was incorporated. Evidence that the ligands were associated with the catalytic site included the observations that reaction occurred only with nucleotides that are substrates or products of the ATPase activity; that the reaction was blocked by pyrophosphate which is an inhibitor of the ATPase activity; that ATP was bound as ADP; and that label was probably restricted to a single peptide following limited subtilisin proteolysis of labeled Acanthamoeba myosin IA heavy chain and extensive cleavage with CNBr and ...
Reactions of consumers to the appearance and taste of pork with and without information concerning outdoor production of pigs were tested in France, Denmark, Sweden and UK. Consumers in all four countries focussed on colour and fatness rather than marbling and drip to make their choice. Almost half of the British and Danish preferred the paler and the French the darker pork. Most people preferred the leaner pork. When information was provided in the form of labels, the vast majority of consumers preferred the pork labelled as originating from their own country as opposed to 'imported' and that labelled as pork from pigs 'raised outside' as opposed to 'inside'. There was no difference in the taste of grilled pork from indoor and outdoor production systems but pork labelled 'home produced' or 'outdoor' were more appreciated. Consumers' willingness to pay varied widely and was higher for those consumers ...
Energy expenditure (EE) of four adult men on a weight-maintenance diet was estimated by use of doubly labeled water, intake balance, and direct and indirect calorimetry. The doubly labeled water (2H218O) method was used to estimate free-living EE for 13 d. Metabolizable energy (ME) intake was used to estimate free-living EE for 1 wk. The subjects' 24-h EE was measured in a dual direct-indirect room calorimeter on 3 alternate days. Estimates of free-living EE as measured by ME intake and doubly labeled water indicate agreement between the two methods (mean difference +/- SEM, -1.04 +/- 0.63%). Measurements of EE with indirect and direct calorimetry are equivalent (mean difference 0.63 +/- 0.44%). The daily EE measured by doubly labeled water in these free-living adults over a 13-d period was 15.01% greater than the 24-h EE measured within the calorimeter.
A new /sup 99m/Tc-phosphine-isocyanide complex with the general structure (/sup 99m/Tc (DEPE)/sub 2/(CNR)/sub 2/)/sup +/ has been synthesised and tested in animals and one human. In three animal species (rat, rabbit, dog), the complex is an efficient myocardial imaging agent, while in humans it remains in the blood pool. The complex is 100% protein bound in animals and humans, but whereas in humans it is attached to a 51.5 kdalton protein (probably prealbumin), in rabbits it appears to be bound to a larger macromolecule (M.W.>100 kdalton). The efficiency of the complex for blood pool labelling was tested in a human volunteer and compared with the standard in vivo red cell labelling technique with stannous pyrophosphate. A satisfactory radionuclide angiogram could be performed with less than 370 MBq of the complex. The count rate for the complex (cps/MBq) was 15% higher than that obtained with the labelled red cells and ...
Partially purified UDPgalactosyltransferase (EC 2.4.1.22) from bovine milk has been used to synthesize millimolar amounts of compounds such as Gal..beta..(1..-->..4)Glc, Gal..beta..(1..-->..4)GlcNAc-..beta..-hexanolamine, and Gal..beta..(1..-->..4)-GlcNAc..beta..(1..-->..4)GlcNAc. The same method has been used to prepare similar compounds containing /sup 13/C-enriched galactopyranosyl moieties. Gal..beta..(1..-->..4)GlcNAc-..beta..-hexanolamine was also synthesized in a solid-phase system in which the GlcNAc-..beta..-hexanolamine glycoside was covalently linked to agarose beads. At pH 7.0 and at 1 to 5 mM Mn/sup 2 + +/ the yields of the galactosyl saccharides are greater than 90% by using 10% excess of UDPGal donor. The use of a 90% enriched (1-/sup 13/C)galactosyl residue allowed the determination of the ...
In the present study, the relationship between the crystallographic orientations and growth directions of grain boundary-allotriomorphic-#alpha# (GB #alpha#) and secondary Widmanstaetten #alpha# laths growing from the GB #alpha# at grain boundaries separating #beta# grains with specific misorientations has been examined. These relationships have been determined using a variety of characterization techniques, including scanning electron microscopy, orientation imaging microscopy, transmission electron microscopy (TEM) and a dual-beam focused ion beam instrument to provide site-selected TEM foils. Two very interesting cases, one in which the two adjacent #beta# grains are rotated mutually by approximately 10.5"o about a common direction and the other in which the two #beta# grains are in a twin relationship, i.e. a 60"o rotation about a common direction, have been studied. It was discovered that the #alpha# laths growing ...
Insulitis is considered the histopathological hallmark of type I diabetes. In the non-obese diabetic (NOD) mouse, diabetes has never been observed in the absence of insulitis. The in vivo detection of insulitis could be of relevance for early prediction of diabetes. As approximately 15% of islet-infiltrating lymphocytes express interleukin 2 receptors, the authors have labelled recombinant inter-leukin 2 with "1"2"3I and used this radiopharmaceutical to detect insulitis by gamma camera imaging. The authors studied 71 prediabetic NOD and 27 normal Balb/c mice. Labelled #alpha#-lactalbumin was used as the control protein. In the first set of experiments the tissue distribution of radiolabelled interleukin 2 in isolated organs from animals sacrificed at different time points was studied. Higher radioactivity was detected in the pancreas of NOD mice injected with labelled interleukin 2, as compared to NOD mice receiving ...
The active site of chicken gizzard myosin was labeled by direct photoaffinity labeling with ["3H]UDP. ["3H] UDP was stably trapped at the active site by addition of vanadate (Vi) and Co"2"+. The extraordinary stability of the myosin.Co2+.[3H]UDP.Vi complex (t1/2 greater than 5 days at 0 degrees C) allowed it to be purified free of extraneous ["3H]UDP before irradiation began. Upon UV irradiation, greater than 60% of the trapped ["3H]UDP was photoincorporated into the active site. Only the 200-kDa heavy chain was labeled, confirming earlier results using ["3H]UTP. Extensive tryptic digestion of photolabeled myosin subfragment 1 followed by high performance liquid chromatography separations and removal of nucleotide phosphates by treatment with alkaline phosphatase allowed two labeled peptides to be isolated. Sequencing of the labeled peptides and radioactive counting showed that ...
Beta-21S is a new, metastable-beta titanium alloy which exhibits excellent oxidation resistance and mechanical properties at elevated temperatures. From a weld solidification standpoint, this alloy chemistry is of particular interest because its major beta-stabilizing elements (Mo and Nb) both exhibit equilibrium partitioning ratios (k_o) greater than unity, indicating their simultaneous partitioning during weld solidification to the initial solid to form (i.e., dendrite cores), and correspondingly their depletion in the final regions of solidification (i.e., dendrite interstices). Such elemental partitioning, if retained down to room temperature, may be expected to promote local variations in the postweld aging response. The objectives of the present investigation were to characterize Gas Tungsten-Arc weld solidification and HAZ liquation phenomena in Beta-21S and to examine the influence of residual ...
Introduction: Thalassemia is the most common hereditary blood disorder in the world. Iran is located on the thalassemic belt and there is a high prevalence of the hepatosplenomegaly in beta thalassemia minor patients which is reported to be very variable. The goal of this research was to study the frequency of these signs in the cases with beta thalassemia minor patients in Iran. Materials and methods: Two hundred and fifty-nine cases that referred to center for pre-marriage tests were divided into two groups according to their MCV, MCH, and HbA2 (beta thalassemia minor cases and control groups). Liver and spleen sizes were determined by ultrasonographic method and the two groups were compared with each other. Results: Average spleen volumes in case and control groups were 163.48 {+-} 133.97 and 126.29 {+-} 53.98 mm{sup 3}, respectively. Average spleen lengths in case and control groups were 10.71 {+-} 1.52 and 10.60 {+-} ...
For optimizing the microstructure of the (#alpha# + #beta#)-titanium alloy TiAl5Fe2.5 the content of the two alloying elements aluminium and iron in the #alpha#- and #beta#-phase was determined by microprobe analysis. The alloys with the composition of the #alpha#- and of the #beta#-phase at 850 degC TiAl6Fe0.5 (#alpha#-phase) and TiAl3.5Fe6.5 (#beta#-phase) were prepared by arc melting and rolling at 850 degC. The mechanical properties of the '#alpha#'- and of the '#beta#'-phase-alloy are compared with the properties of the (#alpha# + #beta#)-alloy TiAl5Fe2.5 in the as rolled and swaged condition and after an additional aging at 550 degC. By this optimizing process it was possible to achieve a tensile strength of Rsub(m) = 1012 N/mm"2, an yield strength of Rsub(p0.2) 954 N/mm"2 and an elongation at fracture A = 14.5% in the TiAl5Fe2.5-alloy, although the degree ...
K beta X-ray lines from partially M-shell-ionized ions of titanium through nickel which are produced in vacuum-spark plasmas have been observed systematically for the first time, using a high-resolution curved-crystal spectrometer. Each K beta line is clearly separated into its corresponding charge state. As a result, it is possible to measure the K beta-type transition energies of the M-shell-ionized ions. The transition energies accurately determined are compared with those calculated for iron ions, and the agreement is excellent except for ions having some additional 3d outer-shell electrons or 3s inner-shell vacancies. The square root of the K beta transition frequency is expressed as a linear function of the nuclear charge for isoelectronic sequences. The effective nuclear charges have been also determined for each K beta transition. The 3p electrons do not affect the effective ...
The crystallography of #alpha#(hcp) precipitates formed on the #beta#(bcc) matrix grain boundaries has been studied with transmission electron microscopy (TEM) in a Ti-15V-3Cr-3Sn-3Al alloy. The #alpha# precipitates have a near-Burgers orientation relationship with respect to at least one of the adjacent #beta# grains. Among the possible 12 variants in this orientation relationship, the variant that [11 bar 20]_#alpha# is parallel to the _#beta# closest to the grain boundary plane tends to be preferred by the #alpha# precipitates. Additionally, further variant selections are made so as to minimize the deviation of orientation relationship with respect to the ''opposite'' #beta# grain from the Burgers one. Such rules in variant selection often result in the formation of precipitates with a single variant at a planar grain boundary. Prior small deformation of #beta# matrix changes the ...
High temperature deformation behavior of an alpha + beta titanium alloy Ti-3Al-4V has been investigated at 910 deg. C. by using the method of cross head speed cycling. On the basis of flow stress, strain rate and strain rate sensitivity data, the alloy was found to exhibit strain hardening at this temperature which resulted in degradation in superplastic properties of the alloy. A high beta-phase volume fraction and grain-growth in both alpha and beta phases were considered responsible for the observed hardening effect. (author)
SP-700, an emerging #beta#-rich #alpha#+#beta# titanium alloy, is designed to improve superplastic formability as well as mechanical properties over Ti-6Al-4V alloy. Owing to its fine microstructure and low #beta#-transus temperature, it is superplastic-formable at temperature below 1,073K (800 C) with low flow stress. Remarkable workability of this alloy is also retained in conventional Manufacturing processes. Another advantage of SP-700 is heat treatment response which includes deep hardenability and quick aging kinetics. Corrosion resistance and machinability are equivalent to or better than Ti-6Al-4V alloy.
Beta-C trademark is a metastable beta titanium alloy which can be heat treated to achieve a good combination of properties such as tensile strength, fatigue strength, ductility and toughness, such as needed in aircraft fasteners. Variations in hot and cold processing parameters and solution heat treatment can affect the resultant grain structure which in turn affects subsequent aging response and mechanical properties. Several processing/heat treating routes on round bar are explored in this study to determine the effects on microstructure and various mechanical properties.
At the RIKEN-RAL Muon Facility, {mu}{sup -} to {alpha} sticking K{sub {beta}} X-rays were observed for the first time taking advantage of the pulsed beam structure. The precision of the present measurements was insufficient to distinguish between theoretical models, however the observed K{sub {beta}}/K{sub {alpha}} X-ray intensity ratio tends to be smaller than most of these theoretical predictions.
The K_#beta#/K_#alpha# X-ray intensity ratios are measured for Mn and Fe and for six other elements with Z lying in the range 49<=Z<=82 following electron capture decay and photon excitation using "2"4"1Am and "5"7Co sources. High-resolution Si(Li) and HpGe detector systems were used in the experiments. The dependence of K_#beta#/K_#alpha# values on the mode of excitation in the case of Mn and Fe is attribuited to the chemical effects, while no such dependence is found for the high-Z elements.
In this work, the half-lives of the beta-unstable nuclei {sup 101}Mo and {sup 101}Tc were studied using neutron-irradiated samples of {sup 100}Mo to produce {sup 101}Mo which in its turn generates {sup 101}Tc by beta decay. The gamma activity of each sample was followed for 5 consecutive half-lives in steps of 5 minutes. A total of 22 sources were measured and checked for dead-time influence, and the half-lives were obtained by weighted average. The results are statistically incompatible with the tabulated values.
In this work, the half-lives of the beta-unstable nuclei "1"0"1Mo and "1"0"1Tc were studied using neutron-irradiated samples of "1"0"0Mo to produce "1"0"1Mo which in its turn generates "1"0"1Tc by beta decay. The gamma activity of each sample was followed for 5 consecutive half-lives in steps of 5 minutes. A total of 22 sources were measured and checked for dead-time influence, and the half-lives were obtained by weighted average. The results are statistically incompatible with the tabulated values.
A method based on path integral formulation is given for obtaining exact solution of the s states for the Bargmann potentialV(r)=1ka"2#beta#(#beta#-1)e"-"2"r"/"a1-e"-"r"/"a"2-Ae"-"r"/"a1-e"-"r"/"a,where #beta# and k are parameters. The exact energy spectrum and the normalised s-state eigenfunctions are obtained from the poles of the Green function and their residues, respectively. The results are compared with their of Schrodinger formalism, special cases are also discussed.
Lithium was selectively extracted from near-neutral aqueous solutions of alkali metal salts. The mechanism by which this was achieved involves the formation of the trioctylphosphine oxide adduct of a lithium chelate of a fluorinated #beta#-diketone, which is then readily extractable into an organic diluent. High separation factors were obtained from sodium, potassium, rubidium, and cesium. The selectivity of the fluorinated #beta#-diketones for lithium over the alkaline earths was found to be poor. A suggested general flowsheet for the recovery of lithium from a salt brine concentrate is included. (author).
Four "1"2"5I labeled mono- and diamines were prepared and evaluated as potential brain-imaging agents. The diamines are analogues of the previously reported "7"5Se labeled diamines, which show high brain uptake and retention. All of the radioiodinated amines display high initial brain uptake in rats after intravenous injection (1.7-2.4% dose/organ). The xylylenediamines show prolonged brain retention (t1/2 approximately 18 h), which is desirable for brain imaging. In contrast, the benzylamine is rapidly cleared from brain tissue (t1/2 approximately 15 min).
In this paper, we introduce a new recursive neural network model able to process directed acyclic graphs with labelled edges. The model uses a state transition function which considers the edge labels and is independent both from the number and the order of the children of each node. The computational capabilities of the new recursive architecture are assessed. Moreover, in order to test the proposed architecture on a practical challenging application, the problem of object detection in images is also addressed. In fact, the localization of target objects is a preliminary step in any recognition system. The proposed technique is general and can be applied in different detection systems, since it does not exploit any a priori knowledge on the particular problem. Some experiments on face detection, carried out on scenes acquired by an indoor camera, are reported, showing very promising results. PMID:16181770
A brief survey is presented of the methods of preparation and of the applications of radiopharmaceuticals labelled with short-lived positron radionuclides "1"1C, "1"8F, "1"3N and "1"5O which, thanks to their energy level schemes, short half-life and the 511 keV photon radiation energy are almost ideal tracers in modern nuclear medicine and pharmacology. In conjunction with computerized tomography, they represent one of the most sensitive diagnostic imaging methods, the so-called positron emission tomography. In addition, their incorporation in the molecule of a pharmaceutical does not change the biological and chemical properties of the original molecule unlike those of radiopharmaceuticals labelled with technetium, iodine, etc. (author). 125 refs.
A series of four 125I-labeled 1-substituted-4-phenylpiperazines were prepared and evaluated in rats as potential brain imaging agents. The compounds were labeled using (125I)iodide/chloramine-T or iodine monochloride and isolated in 48-60% radiochemical yields. The tissue distribution studies indicated that a butyrophenone derivative demonstrated the best overall brain-imaging properties. Compared with the compounds having other 1-substituents this agent had a more prolonged retention of activity in the brain and higher brain-to-blood ratios over the 4-h period studied. The in vivo behavior of this agent is comparable to that of radioiodinated N-isopropyl-p-iodoamphetamine, and, because it can be labeled directly via electrophilic methods, it has substantial potential for use in brain imaging with single photon emission computed tomography.
Wheat leaves can be induced by excision to produce fructans. Fructose residues of newly made oligofructans in leaves labeled in vivo with {sup 14}CO{sub 2} are not equally labeled. We report here on a fructosyl transferase activity in wheat leaves catalyzing the reaction: G{sup *}-F{sup *} + G-F-F = G{sup *}-F{sup *}-F + G-F. This activity, described previously in J. artichoke was attributed to fructan:fructan fructosyl transferase (FFT). The rate of this reaction in vitro is much higher than that of net kestose synthesis by SST. Hence, appearance of labeled 1-kestose from sucrose may not be an accurate measure of SST, but a curious reshuffling of hexoses between pools of 1-kestose and sucrose.
The effect of NaCl and Na_2SO_4 treatments on chlorophyll content, rate of "1"4C assimilation and products of photosynthesis in peanut (Arachish hypogaea L.) variety TMV-10 has been investigated. It was observed that chlorophyll content was affected mainly by NaCl, Na_2SO_4 treatment lowered the rate of photosynthetic "1"4CO_2 fixation. The analysis of labelled products revealed that the salts affect the carbon metabolism differently. The radioactivity was found to be accumulated in fractions of sugars and sugarphosphates in the leaves of NaCl treated plants. Na_2SO_4 treatment brought about considerable decline in labelling of sugars and an increase in labelling of amino acids and sugarphosphates. (orig.).
Hydrophobic labelling is frequently used in the study of membrane-inserted domains of intrinsic proteins. However, the published procedures, fail to incorporate sufficient radioactivity into membrane immunoglobulins of B lymhocytes to permit investigation of their subunit structures and associations with other proteins. In order to increase the specific radioactivity of ["1"2"5I]iodonaphtylazide ["1"2"5I]INA), an improved method for the synthesis of the reagent was developed. In addition, the optimal conditions for labelling B lymhpocytes with ["1"2"5I]INA and commercially available reagent 3-(trifluoromethyl)-3-(trifluoromethyl)-3-(3'-["1"2"5Iliodophenyl)diazirine (["1"2"5I]TID were isolated and analysed in detail by SDS-PAGE. The usefulness of the two reagents for the investigation of lipid-embedded domains of membrane proteins is discussed. (author). 28 refs.; 4 figs.
Although good encryption functions are probabilistic, most symbolic models do not capture this aspect explicitly. A typical solution, recently used to prove the soundness of such models with respect to computational ones, is to explicitly represent the dependency of ciphertexts on random coins as labels. In order to make these label-based models useful, it seems natural to try to extend the underlying decision procedures and the implementation of existing tools. In this paper we put forth a more practical alternative based on the following soundness theorem. We prove that for a large class of security properties (that includes rather standard formulations for secrecy and authenticity properties), security of protocols in the simpler model implies security in the label-based model. Combined with the soundness result of (\\textbf{?}) our theorem enables the translation of security results in unlabeled symbolic models to ...
Copper bioavailability was studied in rats using an extrinsic Cu label. Copper absorption from sunflower seeds (46%), peanuts (41%), cooked shrimp (50%), and cooked beef (40%) was as good or better than copper sulfate (46%). Copper from plant foods (sunflower seeds, garbanzo beans, peanuts) was absorbed equally as well as copper from animal foods (beef, shrimp, chicken liver), 39 +/- 7% vs 43 +/- 7%, P greater than 0.05. There was no significant difference in percentage Cu absorption between intrinsically labeled chicken liver and extrinsically labeled chicken liver. In a second experiment, Cu absorption was measured in the presence of glucose, fructose, sucrose, or cornstarch. There were no significant differences in Cu absorption due to different carbohydrates in a single meal.
The authors have studied the distribution of H-3 labelled schistosomicidal drug in mice by autoradiography. The H-3-labelled substances were found in liver and kidney and in successfully decreasing amounts in brain, lung, heart, fat, testis, pancreas and spleen. In various cells the silver granules were present mainly in the cytoplasms but a few in the nucleus. After administration of this labelled schistosomicidal drug, the mice were killed and studied in groups successively at 4, 8, 24 hrs. No difference in the distribution of silver granules were observed. This fact indicated that, this drug was rapidly absorbed and highly concentrated with a long duration of reservation in liver. All of these favours the schistosomicidal effect of the drug. As this drug was highly concentrated in the cytoplasm of liver cells, that might provide a pathophysiologic basis for the explanation of jaundice in the clinical practice. Moreover, ...
Neurodegeneration observed in Alzheimer disease (AD) is believed to be related to the toxicity from reactive oxygen species (ROS) produced in the brain by the amyloid-{beta} (A{beta}) protein bound primarily to copper ions. The evidence for an oxidative stress role of A{beta}-Cu redox chemistry is still incomplete. Details of the copper binding site in A{beta} may be critical to the etiology of AD. Here we present the structure determined by combining x-ray absorption spectroscopy (XAS) and density functional theory analysis of A{beta} peptides complexed with Cu{sup 2+} in solution under a range of buffer conditions. Phosphate-buffered saline buffer salt (NaCl) concentration does not affect the high-affinity copper binding mode but alters the second coordination sphere. The XAS spectra for truncated and full-length A{beta}-Cu{sup 2+} peptides are similar. The ...
In rat adipocyte membranes, both beta-adrenergic agonists and beta-adrenergic antagonists competed with (--)(/sup 3/H)dihydroalprenolol for high affinity (KD 2-4 nM) and low capacity binding sites. The antagonists but not the agonists competed with (--)(/sup 3/H)dihydroalprenolol for lower affinity and higher capacity sites. The present studies were performed in order to characterize the adipocyte beta-adrenergic receptor and distinguish it from low affinity, higher capacity sites which were heat-labile and not stereoselective. When isoproterenol was used to define the nonspecific binding, saturation studies showed a single binding site with a capacity of approximately 100 fmol/mg membrane protein (corresponding to approximately 50,000 sites/adipocyte). Binding was saturated by 10 nM (--)(/sup 3/H)dihydroalprenolol. Approximate KD's of 204 nM were observed. Kinetic analysis of (--)(/sup 3/H)dihydroalprenolol ...
The constituent phases and associated deformed microstructure of the quenched Ti-xNb-(0.5-1.5) at.% Si alloy consisting of non-cytotoxicity elements, where x = 24-30 at.%, were investigated to provide pseudoelasticity for biomedical and sensor applications. Optical microscopy revealed that stress-induced martensitic transformation takes place during the deformation in the present alloys. It is confirmed from the X-ray diffraction results of the deformed specimens that the crystal structure of the stress-induced martensite phase is the orthorhombic so-called #alpha#'' structure. Within the alloys having #beta#(bcc) phase studied Nb-poor region appeared to exhibit a dominant behavior for stress-induced martensitic transformation than Nb-rich region. This result suggests that metastable #beta# phase is superior to stable #beta# phase for the occurrence of stress-induced martensitic transformation in the present alloy system.
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 ...
In connection with the different cyclical strengths of the two-phase (#alpha# + #beta#) titanium alloy in the case of the acicular and rounded formations of the #alpha#-phase, we have studied, employing the X-ray diffraction method, the phase composition of the alloy and the influence of heat treatment upon it. Using the method of electronic fractography, we examined the fractures in samples destroyed by the asymmetric twisting, in order to find out why the durability of the alloy is dependent upon the #alpha# - phase structure. It has been found that in the BT22 alloy, the decay the #beta#-phase may proceed in two ways; either with the formation of the martensite #alpha#'-phase of the acicular shape or with the separation of the non-martensite round-shaped #alpha#-phase. The character of the phase transformations #beta# - #alpha# or #beta#-#alpha#' is, to a considerable extent, the conseguence of the ...
The morphological development of oxide scales formed on a low Al substituted #beta#-sialon (z=0.2) oxidised for time periods up to 1024h at 1350 C is discussed in relation to oxidation kinetics. The oxidation process is observed to be accompanied by changes in both the phase assemblage of the external layers and their morphology. Thus as the time of oxidation increases beyond 64h the cristobalite-#beta#-yttrium disilicate phase assemblage changes to cristobalite plus #beta#- and #gamma#-yttrium disilicate. In addition to the changes observed for the surface layers, differences are observed in the morphologies of the polished cross-sections. These changes are consistent with an order of magnitude decrease in oxidation rate. (orig.).
Objective To evaluate the inhibitory property of de-glycyrrhizinated extract of Glycyrrhiza glabra root and its phytoconstituents (glabridin, isoliquiritigenin and glycyrrhizin) on LPS-induced production of pro-inflammatory mediators. Materials and methods Inhibitory effect of G. glabra extract and its phytoconstituents were studied on lipopolysaccharide (LPS)-induced nitric oxide (NO), interleukin-1 beta (IL-1 beta) and interleukin-6 (IL-6) levels in J774A.1 murine macrophages. Results G. glabra and isoliquiritigenin significantly inhibited LPS stimulated NO, IL-1 beta and IL-6 production. Glabridin showed significant inhibition of NO and IL-1 beta release, but failed to attenuate IL-6 levels at the tested concentrations. In addition, glycyrrhizin did not exhibit inhibitory response towar...
A kinetic model based on the Mars-van Krevelen mechanism that allows to describe the microkinetics of the heterogeneously catalysed partial oxidation of {alpha}, {beta}-unsaturated aldehydes is presented. This conversion is represented by a network, composed of the oxidation of the {alpha}, {beta}-unsaturated aldehyde towards the {alpha}, {beta}-unsaturated carboxylic acid and the consecutive oxidation of the acid as well as the parallel reaction of the aldehyde to products of deeper oxidation. The reaction steps of aldehyde respectively acid oxidation and catalyst reoxidation have been investigated separately in transient experiments. The combination of steady state and transient experiments has led to an improved understanding of the interaction of the catalyst with the aldehyde and the carboxylic acids as well as to a support of the kinetic model assumptions. (orig.)
We discuss the minimum requirements for a neutrino beta beam if theta_13 is discovered by an upcoming reactor experiment, such as Double Chooz or Daya Bay. We require that both neutrino mass hierarchy and leptonic CP violation can be measured to competitive precisions with a single-baseline experiment in the entire remaining theta_13 range. We find that for very high isotope production rates, such as they might be possible using a production ring, a (B,Li) beta beam with a gamma as low as 60 could already be sufficient to perform all of these measurements. If only the often used nominal source luminosities can be achieved, for example, a (Ne,He) beta beam from Fermilab to a possibly existing water Cherenkov detector at Homestake with gamma \\sim 190-350 (depending on the Double Chooz best-fit) could outperform practically any other beam technology including wide-band beam and neutrino factory.
An experiment on the K#beta#/K#alpha# characteristic X-ray intensity ratio in silver was performed at VEC Centre, Calcutta using the #alpha#-beams at energies 40 MeV and 50 MeV employing a Si(Li) detector system on-line. The results show that the K#beta#/K#alpha# X-ray intensity ratio at energies 40 and 50 MeV are 0.215 #+-# 0.006 and 0.216 #+-# 0.006, respectively, which indicates no change with beam energy and in accordance with the earlier reports. The present experiment shows the feasibility of studying the K#beta#/K#alpha# ratios as a function of beam energy in different regions of periodic table. Experiments in elements belonging to the 3d shell and their compounds are suggested to look for the chemical effects and their dependence on #alpha#-energy. (author). 7 refs.
The influence of serum, IGF-1 and TGF-{beta} on the differentiation of preadipocytes was examined in primary cultures of porcine adipose tissue cells. In serum-supplemented or serum-free, IGF-1 (1 and 10 nM) had no effect on total cell number. However, IGF-1 (10nM) increased adipocyte number only in serum-supplemented (1% pig serum) cultures, whereas TGF-{beta} (15 pm) reduced the adipocyte number in the presence and absence of IGF-1. Replication of preadipocytes was analyzed with a ({sup 3}H) thymidine assay. Preadipocyte proliferation (cpm in adipocyte fraction) was increased by IGF-1 (10nM) only in cultures containing pig serum. TGF-{beta} had no effect on preadipocyte proliferation specifically, but slightly increased total ({sup 3}H) thymidine incorporation in cultures with serum. Glycerol phosphate dehydrogenase (GPDH) specific activity was decreased by adding TGF-{beta} to serum-free cultures but ...
The influence of serum, IGF-1 and TGF-#beta# on the differentiation of preadipocytes was examined in primary cultures of porcine adipose tissue cells. In serum-supplemented or serum-free, IGF-1 (1 and 10 nM) had no effect on total cell number. However, IGF-1 (10nM) increased adipocyte number only in serum-supplemented (1% pig serum) cultures, whereas TGF-#beta# (15 pm) reduced the adipocyte number in the presence and absence of IGF-1. Replication of preadipocytes was analyzed with a ["3H] thymidine assay. Preadipocyte proliferation (cpm in adipocyte fraction) was increased by IGF-1 (10nM) only in cultures containing pig serum. TGF-#beta# had no effect on preadipocyte proliferation specifically, but slightly increased total ["3H] thymidine incorporation in cultures with serum. Glycerol phosphate dehydrogenase (GPDH) specific activity was decreased by adding TGF-#beta# to serum-free cultures but ...
An inclusion complex between imazalil (IMZ), a selected fungicide, and cyclomaltoheptaose (beta-cyclodextrin, betaCD) was obtained using supercritical fluid carbon dioxide. The best preparation conditions were determined, and the inclusion complex was investigated by means of 1H NMR spectroscopy in aqueous solution and 13C CPMAS NMR spectroscopy in the solid state. Information on the geometry of the betaCD/IMZ complex was obtained from ROESY spectroscopy, while the dynamics of the inclusion complex in the kilohertz range was obtained from the proton spin-lattice relaxation times in the rotating frame, T(1rho) (1H). PMID:14553984
The emission lines H#alpha#, H#beta#+[OIII], and L#alpha# have been observed in the high-redshift quasar 1225+31. The ratios of line intensities in 1225+31 are found to be L#alpha#/H#alpha#approx.0.8, H#alpha#/(H#beta#+[OIII]) approx.4, and 4beta#<10. The observed value of L#alpha#/H#alpha# agrees well with the ratio derived by Baldwin on the basis of a composite quasar spectrum, and with direct determination of this ratio in 3C 273 and PKS 0237--23. The ratio H#alpha#/H#beta# is in the range of values found for a sample of low-redshift quasars by Baldwin. The low value for the L#alpha#/H#alpha# ratio cannot be reasonably explained by foreground extinction between the Sun and 1225+31.
In this paper, we investigate the epidemic spreading for SIR model in weighted scale-free networks with nonlinear infectivity, where the transmission rate in our analytical model is weighted. Concretely, we introduce the infectivity exponent $\\alpha$ and the weight exponent $\\beta$ into the analytical SIR model, then examine the combination effects of $\\alpha$ and $\\beta$ on the epidemic threshold and phase transition. We show that one can adjust the values of $\\alpha$ and $\\beta$ to rebuild the epidemic threshold to a finite value, and it is observed that the steady epidemic prevalence $R$ grows in an exponential form in the early stage, then follows hierarchical dynamics. Furthermore, we find $\\alpha$ is more sensitive than $\\beta$ in the transformation of the epidemic threshold and epidemic prevalence, which might deliver some useful information or new insights in the epidemic spreading and ...
#alpha#/#beta# sialon based composites containing silicon nitride whisker and silicon carbide platelet were fabricated by hot pressing. Effect of the reinforcing agents on the #alpha# to #beta# phase transformation of the sialon as well as on the mechanical properties was investigated. Silicon nitride whisker and silicon carbide platelet promoted the phase transformation. TEM/EDS analysis revealed that the grain containing the whisker had 'core-rim' structure; core being high purity Si_3N_4 whisker and rim being #beta#-sialon. Flexural strength of the composite decreased with the reinforcement addition which, on the other hand, improved fracture toughness of it. High temperature strength was measured at 1300 deg C to be about 130 MPa lower than that measured at RT for the whisker reinforced composite. (author).
to be similar to the system of face-on spiral and small companion known as M51, the Whirlpool Galaxy. Tomorrow's picture: Beta Pic < | Archive | Index | Search | Calendar | RSS |...
(#alpha#+#beta#)-SiALON ceramic composites are industrially important materials. Due to their unique chemistry, crystal structure and microstructural features, #alpha#-SiAlON has superior hardness while #beta#-SiALON offers high strength and toughness. The combination of the two phases enables materials engineers to design a ceramic where the physical properties of the composite can be tailored to a particular application. This article presents a general review of the crystal structures, fabrication and properties of the (#alpha#+#beta#)-SiALON composites with special highlights outlining how microstructural tailoring can control the properties of these advanced ceramic alloys. Copyright (1997) Institute of Metals and Materials Australasia Ltd.
The objectives of this research were to investigate the possibility of controlling the #alpha#'/#beta#' phase ratio and morphology in Sialon ceramics. These objectives have been sought by the control of the starting composition, and by post sintering heat treatment. The main emphasis has been on the production of a series of #alpha#' and (#alpha#'+#beta#') Sialon ceramics with a minimum amount of the glass phase by the pressureless sintering technique and using ytterbium (Yb) as an #alpha#' stabilising element. The Yb additions were made via the oxide or the alumino- silicate presynthesised glass; the latter was found to improve the density. The XRD analysis of the as sintered materials revealed #alpha#' to be the dominant phase with minor contributions from #beta#' sialon and/ or 12H A1N polytype. Additions of SiO_2 or #beta#-Si_3N_4 were made to various materials to assess potential mechanisms for ...
A commercially available synthetic nucleic acid probe (SNAP) conjugated to alkaline phosphatase was compared with standard culture techniques for detecting Campylobacter species. The SNAP was able to...Full Text Available
... NE Mall Room B-607, EPA Headquarters, 401 M ... formally adopted and initiated a joint strategy for ... CLI kick-off Partner and Task Force meeting. ...
Using nitrogen-13 initial measurements have been made of rumen ammonia-nitrogen pool size and turnover, and rate of incorporation of ammonia into microbial protein. It is also feasible to measure the rate of incorporation of absorbed ammonia into urea and the appearance of label in saliva.
This study describes procedures and outcomes in a functional analysis of problem behavior of 2 public school students. For a 13-year-old honors student, bizarre tacts (labeled as psychotic speech by...Full Text Available
The metabolism of 14C-labeled fatty acids and triacylglycerols was followed in intact germinating oil palm seedlings as well as in tissue slices. In the germinating seedling, the shoot contained...Full Text Available
Microbes in nature frequently function as members of complex multitaxon communities, but the structural organization of these communities at the micrometer level is poorly understood because of limitations...Full Text Available
An immunoassay employing 125I-labeled enterotoxin B and polystyrene tubes coated with specific antibody was used for assaying purified and crude enterotoxin. Antibody was adsorbed to untreated...Full Text Available
By pretreating simian virus 40-infected BSC-1 cells with glucosamine, [3H]uridine labeling of both cellular and viral RNA can be halted instantaneously by addition of cold uridine. We have...Full Text Available
Convection-enhanced delivery (CED) has emerged as a promising method of targeted drug-delivery for treating central nervous system (CNS) disorders, but the influence of brain structure on infusate...Full Text Available
The adenovirus fiber knob causes the first step in the interaction of adenovirus with cell membrane receptors. To obtain information on the receptor binding site(s), the interaction of labeled cell...Full Text Available
The authors studied the flow of carbon ({sup 14}C) from CO{sub 2} through sucrose to oligofructans in wheat (Triticum aestivum L.) leaves that had been induced by excision to accumulate fructan. Leaves were either labeled for 30 min and then chased in ambient air for 2 h or labeled continuously for 2 h. Fructans were chromatographed on BioGel P2 column. During continuous labeling, the specific activity was highest in sucrose and decreased for fructans with DP 3 to 5, and each increased linearly with time for 2 h. During the chase period, sucrose specific activity increased for 60 min and then declined while oligofructans gained in specific activity through the 2 h period. After 30 min of labeling, the specific activity of fructose moiety of sucrose was equal to glucose but, in oligofructans, those of the individual fructose units were not. The results may provide insight into the fructosyl ...
Platelet deposition on bovine pericardial-tissue mitral-valve prostheses in 11 dogs was observed noninvasively by use of "1"1"1In-labeled platelets and quantified after sacrifice at one (n . 3), 14 (n . 3), and 30 (n . 5) days postimplantation (300-400 microCi of labeled platelets having been injected 24 hours previously). Thrombosis on the sewing ring and pericardial leaflets at one and 14 days and on the leaflets at 30 days was delineated in scintiphotos. In vitro quantification (% injected dose) indicated that the leaflets, sewing ring, and perivalvular tissue retained 0.904% of labeled platelets at one day postimplantation, 0.198% at 14 days, and 0.040% at 30 days. Platelet half-life was reduced to 38 hours at 21 days postimplantation but returned toward the normal (50 hours) with fibrous ingrowth in the sewing ring. Microembolism in lung and kidney, as measured by tissue/blood radioactivity ratio, also was decreased ...
Production of dissolved macromolecules by ambient autotrophic and heterotrophic microbial populations was measured in a eutrophic Florida reservoir by in situ labeling with various radioactive substrates....Full Text Available
Skin sensitization is the most commonly reported occupational illness, causing much suffering to a wide range of people. Identification and labeling of environmental allergens is urgently required to...Full Text Available
BackgroundZibotentan (ZD4054) is a specific endothelin A (ETA) receptor antagonist being investigated for the treatment of prostate cancer. As zibotentan is eliminated...Full Text Available
The synthesis of (3-{sup 15}N)-labeled adenine has been reported by several groups. Each of these syntheses followed essentially the same route, in which the {sup 15}N is introduced by nitration of 4-bromoimidazole under forcing conditions using ({sup 15}N)-HNO{sub 3}. The authors have devised an alternate route which uses an azo coupling reaction for introduction of the {sup 15}N and proceeds through the intermediacy of (5-{sup 15}N)-labeled 5-aminoimidazole-4-carboxamide (AICA). An unrelated route to the (5-{sup 15}N)-labeled 5-amino-imidazole ribonucleoside (AIRs) was recently reported. AICA is a versatile precursor, which is most commonly used for entry into the guanine or isoguanine families, although it is usually used as the AICA-riboside rather than the heterocycle itself. The authors have found that AICA also can be used for the adenine family by cyclization to hypoxanthine using diethoxymethyl acetate in DMF at ...
To gain insight into the process of mitochondrial transmission in yeast, we directly labeled mitochondrial proteins and mitochondrial DNA (mtDNA) and observed their fate after the fusion of two cells....Full Text Available
Choline (Cho)-containing phospholipids are the most abundant phospholipids in cellular membranes and play fundamental structural as well as regulatory roles in cell metabolism and signaling. Although...Full Text Available
The somatic sensory system responds to stimuli of distinct modalities, including touch, pain, itch, and temperature sensitivity. In the past century, great progress has been made in understanding the...Full Text Available
To investigate the fate of intrinsic factor and cobalamin during cobalamin absorption, we incubated enterocytes isolated from guinea pig ileum for periods of up to 30 min with 57Co-labeled...Full Text Available
BackgroundWe have recently reported successful treatment of patients with chronic pain syndromes using human pooled intravenous immunoglobulin (IVIG) in a prospective, open-label...Full Text Available
The use of dideoxynucleotide triphosphates labeled with different fluorescent dyes (dye terminators) is the most versatile method for automated DNA sequencing. However, variation in peak heights reduces...Full Text Available
The sucrose derivative 6'-deoxy-6'-(2-hydroxy-4-azido)benzamidosucrose (6'-HABS) was prepared from sucrose (via 6'-deoxy-6'-aminosucrose) and 4-amino-salicylic acid. 6'-HABS is a competitive inhibitor of sucrose influx into protoplasts from developing soybean cotyledons and of sucrose binding to membranes from the bacteria P. saccharophila. The Ki for inhibition in the soybean protoplasts was 75..mu..M. 6'-Deoxy-6'-(2-hydroxy-3-/sup 125/Iodo-4-azido)benzamidosucrose was prepared by lactoperoxidase iodination of 6'-HABS. Upon photolysis in the presence of membranes from P saccharophila, label from the photoprobe is incorporated into a sucrose inducible polypeptide of mass 84 KD in SDS-PAGE. The polypeptide is protected from labeling by the inclusion of sucrose in the photolysis mixture. Photolysis conditions which lead to specific labeling of ...
Fibroblast cell population kinetics in the developing molar periodontal ligament was investigated in 10, 12, 16 and 20 days old mice by autoradiography after the administration of [3H]thymidine. Labelled...Full Text Available
13C metabolic flux analysis (MFA) is the most comprehensive means of characterizing cellular metabolic states. Uniquely labeled isotopic tracers enable more focused analyses to probe...Full Text Available
The Calorie (kcal) of present U.S. food labels is similar to the original French definition of 1825. The original published source (now available on the internet) defined the Calorie as the quantity...Full Text Available
Colonies of toxin-producing Pasteurella multocida were detected with peroxidase-labeled monoclonal antibodies by a membrane assay. Examination of the specificity of the assay with 29 P. multocida cultures...Full Text Available
Dairy products doubly labeled with 45Ca and 47Ca were used to evaluate an extrinsic labeling procedure for calcium bioavailability determination. Nonfat milk, yogurt, and fresh cheese curd were prepared from caprine milk that was intrinsically labeled with 45Ca. The products were then labeled extrinsically with 47Ca and administered to rats by gavage. The 47Ca to 45Ca ratio in bone and teeth averaged about 1.00 with either milk, yogurt, or CaCl2, but the ratio was about 1.04 when dosed with cheese curd. Ca absorption, determined by whole-body counting of 47Ca, was lower (P less than 0.05) in cheese curd (59%) than in either milk (69%), yogurt (72%), or CaCl2 (72%). Expressed as percent of dose, the absorption of 47Ca was highly correlated with bone 47Ca (r = 0.973) and with bone 45Ca (r = 0.946). Correlation between tibia 47Ca and tibia 45Ca was r = 0.923. For the dairy products tested, our results ...
The hypothesis that the internal viscosity of erythrocytes is governed by the intracellular hemoglobin (Hb) concentration is examined. Here viscosity is determined by labeling of the cytoplasmic reduced...Full Text Available
A solid-phase radioimmunoassay employing 125I-labeled enterotoxins and polystyrene tubes coated with specific antibody has been developed for assaying the relative concentrations of antibodies...Full Text Available
The cDNA encoding the B chain of the plant toxin ricin has been cloned and expressed in monkey kidney COS-M6 cells. The recombinant B chain was detected by labeling the transfected cells with [35S]methionine...Full Text Available
This paper reviews the development of cerebral scintigraphy from its early days of planar imaging with simple technetium-99m labelled compounds to the recent revival of the technique in the form of...Full Text Available
Hairpin oligonucleotides were synthesized with stems ending in a double-stranded structure, which can be ligated to double-strand breaks in DNA, and with loops that contain nucleotides modified by the...Full Text Available
A multispecialty panel of physicians evaluated a case series of 53 composite-materials workers in a large aircraft manufacturing facility who filed workers' compensation claims for illness labeled by...Full Text Available
Amino acids labelled with dimethylaminoazobenzenesulphonyl chloride can be separated by reversed-phase high-pressure liquid chromatography and detected in the visible region (436 nm). All 19 naturally...Full Text Available
The Food Safety and Inspection Service (FSIS) of the United States Department of Agriculture (USDA) inspects domestic and imported meat and poultry food products to assure the public that they are safe, wholesome, not economically adulterated and properly labeled. The Service also monitors the activities of meat and poultry plants and related activities in allied industries, and establishes standards and approves labels for meat and poultry products. As part of its responsibility, shortly after the Chernobyl accident occurred, FSIS developed a plan to assess this accident's impact on domestically produced and imported meat and poultry
Six kinds of diamino-dithiol compounds are labelled with "9"9Tc"m by ligands exchange reaction. Their ligands exchange percentage is over 95%. The biodistribution of one of these compounds in mice shows 0.88% brain uptake after two minutes and 0.28% after 15 minutes respectively. Although the brain uptake is lower for this compound, it has longer retention in brain. So, the experiment results are valuable to the design of new brain imaging agent in the future.
Syntheses of all five of the singly labeled (/sup 15/N)adenines are now provided. The presence or absence of two-bond /sup 15/N-/sup 1/H spin couplings in their /sup 1/H NMR spectra confirm the location of the isotope in each case. The fragmentation patterns in their mass spectra are indicative of the sequential losses of HCN units and of CH/sub 2/N/sub 2/ from adenine upon electron impact.
We describe a compact ultrafiltration system for the removal of pyrogens and bacteria from water labeled with the stable isotopes of deuterium and oxygen-18. The ultrafiltration system is constructed from readily available commercial components and can achieve complete removal of pyrogens and bacteria from 1L contaminated water within 30 min. By use of our procedure, loss of the isotopically labeled water by retention in the filtration system was minimal. The purified water is suitable for both oral and intravenous administration to healthy human subjects participating in nutrition studies.
An isotopic exchange method was used to label lipiodol with [sup 131]I. The labelling efficiency was > 92.5%, and the radiochemical purity of [[sup 131]I]lipiodol was above 98% as determined by ITLC. The influencing factors e.g. the heating temperature, reaction, pH and storage conditions were studied and the optimum conditions were determined. In a pilot study injecting [[sup 131]I]lipiodol for the treatment of hepatoma, about 70% of hepatoma patients had a response to the treatment with a reduction of [alpha]-fetoprotein and decrease of hepatoma sizes. The overall median survival was 9 months (range 2-17 months). (author).
An azido-"1"2"5iodo-ansamycin (1) in the geldanamycin family was prepared in two steps in one reaction vessel from 17-amino-22-(4'-aminophenacyl)-17-demethoxygeldanamycin (3). The title compound was suitable for photoaffinity labeling proteins that interacted with ansamycins. An alternative synthesis is reported for preparation of unlabeled title compound in order to afford practical amounts of (1) for conventional biochemical studies. (Author).
An azido-[sup 125]iodo-ansamycin (1) in the geldanamycin family was prepared in two steps in one reaction vessel from 17-amino-22-(4'-aminophenacyl)-17-demethoxygeldanamycin (3). The title compound was suitable for photoaffinity labeling proteins that interacted with ansamycins. An alternative synthesis is reported for preparation of unlabeled title compound in order to afford practical amounts of (1) for conventional biochemical studies. (Author).
Our major goal of our work has been to develop and use NMR techniques to study how methanogenic archaebacteria deal with osmotic stress with the hope of providing insights into increasing the salt tolerance of other cells. The project has three main sections: (i) in vivo studies of methanogens; (ii) use of {sup l3}C- and {sup l5}N- labeled potential precursors and in vitro analyses of specific label uptake for elucidation of osmolyte dynamics and biosynthetic pathways of osmolytes in these organisms, and isolation of key biosynthetic enzymes; and (iii) collaborative studies on identification of organic solutes in other methanogens.
Our major goal of our work has been to develop and use NMR techniques to study how methanogenic archaebacteria deal with osmotic stress with the hope of providing insights into increasing the salt tolerance of other cells. The project has three main sections: (i) in vivo studies of methanogens; (ii) use of [sup l3]C- and [sup l5]N- labeled potential precursors and in vitro analyses of specific label uptake for elucidation of osmolyte dynamics and biosynthetic pathways of osmolytes in these organisms, and isolation of key biosynthetic enzymes; and (iii) collaborative studies on identification of organic solutes in other methanogens.
Possibilities of applying the Pb/sup 203/ isotonic solution without a carrier as a label of blood erythrocytes, are found. There is a number of advantages in the Pb/sup 203/ isotonic solution without a carrier, such as a high label efficiency (above 95%), a short half-life (52 hours), and a low radiation dose. These factors prove to be favourable as compared with Cr/sup 51/ widely used for these purposes. Besides, of all preparations used up to now to treat erythrocytes and to scan the spleen, it is only in the case of Pb/sup 203/ isotonic solution without a carrier that no weight amounts of chemical substances do not enter the organism.
In the use of doxorubicin and radiation for treatment of human malignant tumors in vivo, the relationship between treatment-induced apoptosis and Ki-67 labeling index was investigated. Four human tumor xenografts (ependymoblastoma, NNE; primitive neuroectodermal tumor, YKP; small cell lung carcinoma, GLS; glioblastoma, KYG) were transplanted under the skin of thigh of the nude mice (BALB/cA JcL-nu). The mice were given a single radiation dose of 1 Gy, or doxorubicin alone intraperitoneally at a dose of 8 mg/kg. After treatment, sections of tumor specimens were prepared from paraffin-embedded tissues. Hematoxylin and eosin staining, TUNEL staining, and immunohistochemical analysis of Ki-67 were performed. In NNE, apoptotic cells appeared most frequently after treatment compared with all other tumors, and the incidence of apoptosis in the radiation-treated group was much higher than in the doxorubicintreated group. As the incidence of apoptosis in NNE increased, the ...
The patients studied were referred for routine abscess localization with indium-111 labelled autologous leukocytes. One series (n=15) was studied at 1 day after reinjection of labelled cells and a second series (n=9) was studied between 4 hours and 4 days after reinjection of labelled cells. The leukocytes were isolated by a gravity sedimentation method and labelled with In-111 oxinate according to Roevekamp and co-workers. The labelled cell suspension administered to the patient contained between 11 and 15 MegaBq (300-400 microCi). The indium-111 concentration in the liver and spleen was quantitated using a scintillation camera and an on-line computer system. Phantom studies were carried out to obtain conversion factors from geometric mean counts to MegaBq of activity for both liver and spleen. Once determined, the amount of activity in liver and spleen was corrected for physical ...
The purpose of this work was to develop a high specific activity radioiodinated cell membrane probe for tracking lymphocytes in-vivo to replace the nucleus localizing, cytotoxic lipophilic chelates (In-111 oxine and Tc-99m HMPAO) currently used. Alkylation of parent dye 4-[2-[-N,N-didecylamino]phenyl]ethenyl pyridine with E-1-tributylstannyl-3-tosylpropene (prepared form E-1-tributylstannyl-1-propene-3-ol), gave a tributyltin precursor 1. Radiolabeled 3-[4-[2-[4-(N,N-didecylamino)phenyl]ethenyl]pyridino] E-[I-125]-1-iodopropene (2), was prepared from 1 using peracetic acid in acetonitrile/water. Labeling yields and specific activities achieved were 26% (#approx#2170 Ci/mmol), 40% (1220 Ci/mmol), and 55% (200 Ci/mmol) for nca, 0.4, and 2 nanomole carrier iodide runs respectively. Canine mixed leukocytes (0.5-1.0 x 10"8 cells) were labeled with 2 (67% and 42% yields for 200 Ci/mol and 1220 Ci/mmol preparations) and showed blood clearance similar ...
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 ...
The use of natural products in all over the world has been increased in Brazil as well as in other countries. Maytenus ilicifolia is commonly used in popular medicine. The labeling of red blood cells (RBC) with technetium-99m ("9"9"m Tc) have been for many studies in nuclear medicine. This labeling procedure depends on a reducing agent and stannous chloride is normally used. Here, we investigate if the extract of Maytenus ilicifolia is capable to alter the labeling of RBC and blood proteins with "9"9"m Tc. Blood samples were incubated with Maytenus ilicifolia. Stannous chloride solution and Tc-99m were. Blood was centrifuged and plasma (P) and blood cells (C) were isolated. Samples of P or C were precipitated with trichloroacetic acid, centrifuged and IF and IF were separated. The percentage of radioactivity (% ATI) in C, IF-P and IF-C was calculated. The %ATI in decreased in C from 93.6#+-#2.3 to 29.0#+-#2.7, on FI-P from ...
Bone formation and resorption have been measured in patients with idiopathic osteoporosis by histomorphometry of 7.5-mm trephine biopsies and in the whole body by 85Sr radiotracer methodology and calcium balances. The studies were synchronized and most were preceded by double in vivo tetracycline labeling. Correlations between histological and kinetic bone formation indices were better when better when based on the extent of double tetracycline labels than on measurements of osteoid by visible light microscopy. Correction of the kinetic data for long-term exchange, using 5 months' serial whole body counting of retained 85Sr, improved the fit of the kinetic to the histological data. A statistical analysis of the measurement uncertainties showed that the residual scatter in the best correlations (between exchange-corrected bone formation rates and double-labeled osteoid surface indices) could be attributed to ...
The K alpha / K beta ratio of Mn KX-rays scattered by metallic samples changed remarkably with the geometry between the sample and the (55)Fe source-Si(Li) detector system. On the contrary, this intensity ratio changed little in the cases of non-metallic scatterer samples such as lucite or mylar. This difference is interpreted as due to the occurrence of strong or weak interference in the coherent scattering photons. PMID:7280291
The presence of an amino acid other than aspartic acid at position 57 of the HLA-DQ beta chain (non-Asp-57) is highly associated with susceptibility to insulin-dependent diabetes mellitus (IDDM), whereas...Full Text Available
The threshold stress itensities for stress corrosion crack propagation in beta titanium alloy 38-6-44, Ti-3Al-8V-6Cr-4Mo-4Zr, has been determined in salt water and methanolic solutions. The alloy was immune to stress corrosion cracking in aqueous sodium c...
Assessment of the roles of the carboxyl-terminal #beta#146 histidyl residues in the alkaline Bohr effect in human and normal adult hemoglobin by high-resolution proton nuclear magnetic resonance spectroscopy requires assignment of the resonances corresponding to these residues. By a careful spectroscopic study of human normal adult hemoglobin, enzymatically prepared des(His146#beta#)-hemoglobin, and the mutant hemoglobins Cowtown (#beta#146His #-># Leu) and York (#beta#146His #-># Pro), the authors have resolved some of these conflicting results. By a close incremental variation of pH over a wide range in chloride-free 0.1 M N-(2-hydroxyethyl)piperazine-N'-2-ethanesulfonic acid buffer, a single resonance has been found to be consistently missing in the proton nuclear magnetic resonance spectra of these hemoglobin variants. The results indicate that the contribution of the ...
This volume of the monograph covers the following topics: activation analysis, non-activation interaction analysis (elastic scattering of charged particles, absorption and backscattering of beta radiation and photons, radionuclide X-ray fluorescence analysis, thermalization, scattering and absorption of neutrons, use of ionization caused by nuclear radiation, use of ionization by alpha or beta radiation for the measurement of pressure, density and flow rate of gases), and automation in radioanalytical chemistry. (P.A.).
Methanosarcina thermophila, a nonmarine methanogenic archaebacterium, can grow in a range of saline concentrations. At less than 0.4 M NaCl, Ms. thermophila accumulated glutamate in response to increasing osmotic stress. At greater than 0.4 M NaCl, this organism synthesized a modified #beta#-amino acid that was identified as N"v"a"r"-"e"p"s"i"l"o"n-acetyl-#beta#-lysine by NMR spectroscopy and ion-exchange HPLC. This #beta#-amino acid derivative accumulated to high intracellular concentrations (up to 0.6 M) in Ms. thermophila and in another methanogen examined - Methanogenium cariaci, a marine species. The compound has features that are characteristic of a compatible solute: it is neutrally charged at physiological pH and it is highly soluble. When the cells were grown in the presence of exogenous glycine betaine, a physiological pH and it is highly soluble. When the cells were grown in the presence of exogenous glycine ...
Chronic and adult-onset GM2 gangliosidoses are neurological disorders caused by marked deficiency of the A isoenzyme of beta-hexosaminidase; they occur in the Ashkenazi Jewish population, though less...Full Text Available
This report continues the studies of simplified methods, of magnetic diagnostics in application to TCA/BR tokamak. Here we study the accuracy of known formula for {beta}{sub 1} + l{sub 1}/2 determination from the poloidal magnetic field asymmetry. Errors of the diamagnetic measurements due to vibrations of the vacuum vessel are also considered. (author). 3 refs., 1 fig., 1 tab.
Our studies on K#beta#/K#alpha# X-ray intensity ratios of some of the technologically important 3d-transition metal compounds have been reviewed. Comparison of the experimental results with single-configuration Dirac-Fock calculations provided important information on the valence states of the transition metals in various compounds, which can be helpful in understanding the nature of bonding in the compounds. (author)
Ksub(#beta#)/Ksub(#alpha#) X-ray intensity ratios have been measured for various elements between Z = 29 and Z = 79 for incident proton energies of 23.6, 32.1 and 43.6 MeV. The results yield no evidence for a variation in ratio with particle energy. (orig.).
TEM and HRTEM have been used to characterise the microstructures of materials formed by hot-pressing silicon nitride with an Al_2O_3-SiO_2-TiO_2 densification aid system, to form #beta#'-sialon-TiN composites in which the TiN particles are of 20-100 nm dimension. (orig.).
BackgroundThe beta-defensin gene cluster (DEFB) at chromosome 8p23.1 is one of the most copy number (CN) variable regions of the human genome. Whereas individual DEFB CNs have been...Full Text Available
BackgroundEstrogen receptors alpha (ERα) and beta (ERβ) are transcription factors (TFs) that mediate estrogen signaling and define the hormone-responsive phenotype...Full Text Available
The $\\beta$ function for a scalar field theory describes the dependence of the coupling constant on the renormalization mass scale. This dependence is affected by the choice of regularization scheme. I explicitly relate the $\\beta$-functions of momentum cut-off regularization and dimensional regularization on scalar field theories by a gauge transformation using the Hopf algebras of the Feynman diagrams of the theories.
Cyclic strength of #alpha#+#beta#-titanium alloy BT3-1 is studied under load frequencies of 33 and 300 Hz. The increase in the cyclic strength with growing frequency is caused by formation of FCC interphase layers of titanium hydrides. Their formation is one of possible ways of raising the fatigue strength of titanium alloys. Peculiarities of FCC interlayer formation in #alpha#+#beta# phases under loading frequency variation are revealed.
Changes in the phosphate metabolism of the transplanted SCCVII (squamous cell carcinoma VII) tumor were studied before and after irradiation using in vivo [sup 31]P-magnetic resonance spectroscopy (MRS). Phosphocreatine (PCr), [gamma]-, [alpha]-, [beta]-ATP, inorganic phosphate (Pi), phosphomonoester (PME), and phosphodiester (PDE) were detected in [sup 31]P-MR spectra of tumor tissues. The curve fitting method was employed for calculating each peak of [sup 31]P-MR spectra (PCr, [beta]-ATP, Pi, PME, PDE). The values of PCr, PCr/Pi, [beta]-ATP/Pi and pH decreased in proportion to the growth of tumor, whereas that of Pi, PME and PDE increased. But the changes of [beta]-ATP were minimal in degree. Based on the fact that the ratio of PCr/Pi highly correlated with tumor volume and showed the most remarkable change among various parameters, it might be the useful index for the tumor growth. Because the ...
Two methods, a traditional emulsion technique and a high voltage electrostatically modified encapsulation system, were used to fabricate degradable chitosan/beta -tricalcium phosphate (beta-TCP) microspheres. The two distinct kinds of microspheres both exhibited good sphericity and the beta-TCP was trapped well inside the chitosan gel. The microspheres prepared by high voltage electrostatic system exhibited a rougher outer surface and narrower size distribution. These microspheres were then used as an added constituent to commercially available PMMA bone cement. Four modified cement composites that were prepared with different composition ratios of the two kinds of chitosan/beta-TCP microspheres that were made from emulsion technique (C1P1 and C2P1) and from a process by a high voltage electrostatic system (EC1P1 and EC2P1) were compared with the PMMA cement (Pure P). The characteristics of these ...
The enzyme indol-3-ylacetylglucose synthase (UDP-glucose:indol-3-ylacetate beta-D-glucosyltransferase) catalyses the reaction: [formula: see text] This is the first step in the series of reactions leading...Full Text Available
The Ksub(#beta#)/Ksub(#alpha# 12) x-ray intensity ratio of the Si K spectrum was measured for proton impact on Si0_2 in the energy range 300-800 keV. An energy dependence of the intensity ratio was found and an explanation is given in terms of multiple ionisation. (author).
CTX-M extended-spectrum beta-lactamases (ESBLs) have emerged as the most common type of ESBL globally, their incidence easily surpassing those of SHV and TEM ESBLs in most locales. This study compared...Full Text Available
Peculiarities of metastable #beta#-solid solution decmposition in titanium alloy VT30 in the process of isothermal ageing in the range 500-650 deg C are investigated. Using the methods of transmittion electron microscopy, X-ray diffraction analysis, etc., it is shown that in the case of alloy quenching from the temperature below the point of complete polymorphous transformation (T_t_._t_.), as well as after warm rolling the course of subsequent decomposition of solid solution can be consierably complicated.
Chemical influences on the relative Ksub(..beta..)/Ksub(..cap alpha..) x-ray intensity ratio up to five per cent were found for different chemical constitutions of Cr, Mn, Fe and Cu by very precise PIXE measurements. In the discussion of these effects, screening of 3p electrons by a varying 3d valence charge, as well as polarizational effects are of importance.
Chemical effects on the intensity ratio of LX-ray of molybdenum compounds irradiated by 11-keV electrons and by 3-MeV protons were studied using an x-ray crystal spectrometer. It was found that the intensity ratios of L_#gamma#_1/L_#beta#_1 markedly decrease with the increase of ionicity of molybdenum compounds, except for the case of metallic molybdenum. (author).
The ..beta.. decay half-lives of neutron-rich isotopes with Z=24-28 are calculated in the QRPA with a Gamow-Teller residual interaction. For odd-mass and odd-odd systems QRPA phonon correlations are introduced to quasiparticle transitions in first-order perturbation. The calculated half-lives agree very well with the experimental values. For later application of this model to nuclei far from stability, we have examined the dependence of the calculated half-lives on the model parameters.
The #beta# decay half-lives of neutron-rich isotopes with Z=24-28 are calculated in the QRPA with a Gamow-Teller residual interaction. For odd-mass and odd-odd systems QRPA phonon correlations are introduced to quasiparticle transitions in first-order perturbation. The calculated half-lives agree very well with the experimental values. For later application of this model to nuclei far from stability, we have examined the dependence of the calculated half-lives on the model parameters. (orig.).
In the investigations reported here, a helium-jet/tape-transport system was used for the rapid transfer of fission products to a low-background environment where their aggregate beta and gamma-ray spectra were measured as a function of delay time after neutron induced fission of {sup 235}U, {sup 238}U and {sup 239}Pu. Beta and gamma-ray energy distributions have been deduced for delay times as short as 0.2 s and extending out to 100,000s. Instrumentation development during the initial phase of the project included: (1) assembly and characterization of a NaI(Tl) spectrometer for determining aggregate gamma-ray energy distributions, (2) development and characterization of a beta spectrometer (having excellent gamma-ray rejection) for measuring aggregate beta-particle energy distributions, (3) assembly and characterization of a Compton-suppressed HPGe spectrometer for determining gamma-ray intensities of ...
Design of a beam position monitor (BPM) which is sensitive to low velo charged particle beams is considered. Quantitative estimates are made for the corrections to the conventional approximations to solutions of the Laplace Equation in two-dimensions when a BPM is used to measure to position of low velocity (low-[beta]) beams. (AIP)
A beta titanium alloy was evaluated for use in orthodontic appliances. Standard mechanical tests and aspecially designed spring test were used. Two particular thermo-mechanical treatments resulted in titanium springs with 1.8 times the extension of comparable stainless steel springs, and a 2.2 fold reduction in force per unit displacement. PMID:283089
In this paper the effect of adding commercially pure yttria concentrate and yttrium carbonate concentrate (NUCLEMON) on the densification of #beta#-Sialon has been studied. The specimens were sintered in graphite furnace at 1720 and 175 deg C, for 1 hour in a nitrogen atmosphere. Densities of up to 99% of the theoretical density were obtained. Microstructural analyses of the specimens were carried out with the aid of an X ray diffractometer and a scanning electron microscope. (author)
The aim of this work is to test the catalytic oxidation of pyridine over zeolite-supported catalysts and to compare the difference in their activities for the oxidation of pyridine. The catalytic oxidation of pyridine pollutant on a series of copper-supported catalysts, inclusive of Cu/beta, Cu/ZSM-5, Cu/MCM-41 and Cu/{gamma}-Al{sub 2}O{sub 3}, in the presence of excess oxygen was studied. The activity of the copper-supported catalysts for the pyridine oxidation could be correlated with the binding energy of oxygen coordinated to metal copper, while the ability to control the yield of NO{sub x} appeared to be strongly dependent on the binding energy of NO bonded to metal copper. On these catalysts, two copper species, Cu(H{sub 2}O){sub 6}{sup 2+} ions and CuO were identified, in which Cu{sup 2+} ions had higher activity for the NO{sub x} control but poorer activity for the pyridine oxidation. Amongst those metals-supported beta catalysts, ...
#beta#-SiAlON was synthesized from a zeolite by NH_3 gas nitridation and its formation mechanism was investigated using X-ray diffraction and "2"9Si and "2"7Al NMR spectroscopy. It was revealed that most of the Si and Al atoms react to form #beta#-SiAlON via amorphous forms of Si-Al-O-N and O-SiAlON. Nitridation using NH_3 gas is an effective means of preventing mullite formation and promoting the introduction of nitrogen into aluminosilicate materials at lower temperatures than temperatures required by the carbothermal reduction nitridation process. Further, the NMR spectra showed that the siliceous part of the system changed into low z-value of Si_6_-_zAl_zO_zN_8_-_z (#beta#-SiAlON) and the incorporation of Al components into the #beta#-SiAlON was promoted in the later stages of the reaction. (author)
The crystal structure of outer surface protein A (OspA) from Borrelia burgdorferi contains a single-layer #beta#-sheet connecting the N- and C-terminal globular domains. The central #beta#-sheet consists largely of polar amino acids and it is solvent-exposed on both faces, which so far appears to be unique among known protein structures. We have accomplished nearly complete backbone H, C and N and C";/H"#beta# assignments of OspA (28 kDa) using standard triple resonance techniques without perdeuteration. This was made possible by recording spectra at a high temperature (45 "oC ). The chemical shift index and "1"5N T_1/T_2 ratios show that both the secondary structure and the global conformation of OspA in solution are similar to the crystal structure, suggesting that the unique central #beta#-sheet is fairly rigid.
The papers contained in this volume provide an overview of recent theoretical and experimental research related to the fracture toughness and fatigue crack growth characteristics of titanium alloys. Topics discussed include room temperature fatigue crack propagation in beta-titanium alloys, fatigue crack growth rate acceleration in alpha+beta Ti alloys, influence of transformed beta microstructures on fatigue crack growth rates in Ti-6Al-4V, and the role of inclusion and pore content on the fracture toughness of powder processed blended elemental Ti-10V-2Fe-3Al. Papers are also presented on fatigue crack growth measurements in an alpha-beta titanium alloy, the effects of thermal processing variation on the properties of Ti-6Al-4V, and the effect of microstructure on ductility and fracture toughness of alpha+beta titanium alloys.
The production of cellulolytic enzymes from fungi has been extensively studied. Several mutants of Trichoderma reesei were selected. Most of the studies were carried out on T. reesei, T. viride, T. harzianum, Penicillium funiculosum, Altemaria alternata. Aspergillus phoenicis, A. ustus, A. tamarii, A. japonicus, and A. niger. T. koningii is one of the most active producers of the so-called C, factor, which is indispensable for the rapid and extensive attack on crystal-line cellulose. However, Trichodenna is known to excrete only small amounts of {beta}-glucosidase. Therefore, Trichoderma is supplemented with {beta}-glucosidase from Aspergillus to increase the saccharification rate of cellulose to glucose as the main sugar. Induction of mutations in Trichodenna spp. rather than T. viride as a tool for the enhancement of {beta}-glucosidase activity was reported. Unfortunately, T. reesei is a poor producer of ...
The usually low wear resistance of titanium materials can be increased by the thermochemical surface treatment nitriding. In result of comparative investigations of gas and plasma nitriding it will be shown that it is possible to obtain a specific variation of the properties in the highly stressed case by means of these both technologies on example of the ({alpha}+{beta}) alloy Ti-6Al-4V. Gas and plasma nitriding was carried out in the temperature range from 650 to 800 C over 4 to 48 h in different gas atmospheres, i.e. 100% NH{sub 3} (gas), 100% N{sub 2} (gas and plasma), 20% H{sub 2} + 80% N{sub 2} and 20% Ar + 20% H{sub 2} (plasma). The temperature range was fixed in the middle of ({alpha}+{beta}) region, because the core properties are influenced negative in the field of {beta}-transustemperature. The relations between the applied nitriding technologies, the layer structure (chemical, phases, geometrical) and selected ...
The crystal structure and phonon densities of states (DOS) of #beta#'-SiAlON ceramics, Si_6_-_zAl_zO"zN_8_-_z (0 #<=# z #<=# 4), prepared by a novel slipcast method, are studied by neutron-scattering techniques. The samples with z < 4 form a single-phase solid solution of Si-Al-O-N isostructural to #beta#-Si_3N_4 (space group P6_3/m). A consistent preferential occupation of the 2c sites by oxygen atoms and the 6h sites by nitrogen atoms exists within this structure. The phonon DOS of #beta#'-SiAlON displays phonon bands at #approx#50 and 115 meV. These features are considerably broader than the corresponding ones in #beta#-Si_3N_4 powder.
The gene expression of beta(1)-adrenergic receptor (beta(1)AR) and stimulatory G-protein Gsalpha in ventricle after chronic treatment with doxorubicin (DOX) in rat was investigated. The rats were treated with DOX in a dose of 2.5 mg/kg once a week for 5 weeks, the cumulative dose being 12.5 mg/kg. Two weeks after the last injection, the positive inotropic effect of isoproterenol was noticeably decreased in left atrial muscle preparations isolated from DOX-treated rats. Northern blot hybridization showed that the mRNA transcripts of beta(1)AR and Gsalpha, important signal transduction elements for regulating heart rate and contractility, were significantly decreased in the ventricle of DOX-treated rats. Thus, chronic treatment with DOX decreases the gene expression levels of myocardial beta(1)AR and Gsalpha. PMID:15353854
The neutron-rich nuclei"5"7","5"8_2_1Sc,"5"8"-"6"0_2_2Ti,"6"0"-"6"3_2_3V,"6"2"-"6"6_2_4Cr have been produced at Ganil via interactions of a 61.8A MeV "7"6Ge beam with a "5"8Ni target. Beta-decay studies have been performed using combined #beta#- and #gamma#-ray spectroscopy. Half-lives have been determined and #beta#-decay schemes are proposed for "5"8Ti, "6"1V and "6"2Cr. From these studies, new hints for the existence of #beta#-decaying isomers in "6"0V and in "6"2Mn are provided. These results are compared to shell model calculations. The role of the #pi#f_7_/_2- #nu#f_5_/_2 proton-neutron interaction is examined through its influence on the lifetime values. (orig.)
In order to improve the measuring efficiency, a 'proton-gamma' coincidence technique in combination with a He-jet tape transport system was proposed and employed to identify the #beta#-delayed proton precursors. The study of #beta#-delayed proton decays near the proton drip line by using the 'proton-gamma' coincidence technique over the last 5 years at the Institute of Modern Physics, Lanzhou, China, was summarized. New #beta#-delayed proton precursors "1"2"1Ce, "1"2"5Nd, "1"2"8Pm, "1"2"9Sm, "1"3"5Gd, "1"3"7Gd, "1"3"9Dy, "1"4"2Ho, and "1"4"9Yb in the rare-earth region along a speculated proton drip line were synthesized and identified for the first time. The #beta#-delayed proton decays of "8"1Zr, "8"5Mo, "8"9Ru, and "9"3Pd in T_z=1/2 series as well as "9"2Rh in T_z=1 series were observed.
One of the refinements of modern Nuclear Medicine is the capacity of providing dynamic and kinetics images of the administered radiopharmaceutical, reproducing its transport mechanism, action sites, receptor binding and excretion route. With the continues technological advances new radiopharmaceuticals have been developed in order to express higher specificity and with higher characters of affinity between receptor/complex. One radiopharmaceutical is formed by a reagent or bio molecule that has in its structure a radioisotope, that has the objectives of carrying it to the organs of affinity or to benign or malign tumoral process. Somatostatin inhibits the growing and proliferation of several tumoral cells. Somatostatin analogs bind to somatostatic receptors that are expressed in different kind of neoplasia DOTA-LANREOTIDE (DOTALAN) is an octapeptide analog to somatostatin. The interest of labeling the bio conjugate with gallium-67 in Nuclear Medicine comes from its ...
In the present study, the immunomodulatory effect of {beta}-endorphin ({beta}-E) and shorter pro-opiomelancortin (POMC) fragments was evaluated by assessing their influence on respiratory burst in human polymorphonuclear leukocytes (PMN). The effect of the peptides on phorbol myristate acetate (PMA)-stimulated production of reactive oxygen metabolites was measured in a lucigenin-enhanced chemiluminescence (CL) assay. Both POMC peptides with opiate-like activity and their non-opioid derivatives were tested. With the exception of {alpha}-E, PMA-stimulated respiratory burst was suppressed by all POMC fragments tested. A U-shaped dose-response relation was observed. Doses lower than 10{sup {minus}17}M and higher than 10{sup {minus}8}M were without effect. {beta}-E and dT{beta}E both suppressed PMA-induced oxidative burst in human PMN at physiological concentrations. {gamma}-E and dT{gamma}E proved to be ...
The kinetic and guiding center fluid theories of high-..beta.. plasma containment in mirror machines have been developed in a number of self-consistent models. The geometrical effects of magnetic field and ambipolar potential variation have been incorporated in a bounce-averaged Fokker-Planck code which shows that the square-well model somewhat overestimates the n tau and ..beta.. achievable in a mirror field. Simple analytic approximations to the resulting pressure profiles have been incorporated in three-dimensional fluid-equilibrium codes which show the effect of coil geometry on the maximum ..beta... Strongly curved vacuum fields allow higher ..beta.., but short plasmas in weakly curved fields tend to reverse the curvature locally before the mirror-mode limit is reached. Adiabaticity of particle orbits is described in terms of general formulas, applicable in high-..beta.. plasma ...
The beta transformation characteristics and mechanical properties of the #beta# titanium alloy Ti_5_0Zr_3_0Nb_1_0Ta_1_0 in the temperature range between 200 and 900 deg. C have been studied by means of X-ray diffraction (XRD), Vickers hardness (HV), and tensile test techniques. In the as-rolled state, only #beta#-phase was identified by XRD. Upon heat-treating at 250 deg. C for 4 h, the #alpha#-phase was precipitated from the #beta#-phase matrix, and leading to an increase of Vickers hardness. A maximum HV value was observed at 400 deg. C, and then HV value decreased with increasing heat-treating temperature. Above 650 deg. C, HV value remained almost constant. During heat-treating at 300-650 deg. C, the decomposition of the metastable #beta#-phase has been found to proceed through a phase separation reaction leading to the formation of #beta#-Ti and ...
The development of the microstructure on aging of an (#alpha# + #beta#) type titanium alloy containing 6Al-1.6Zr-3.3Mo-0.3Si (VT9) (in weight percent) has been studied. The #beta#-transus temperature of this alloy is approximately 1243 K. Solution treatment in the #beta#-phase field of the alloy followed by quenching in water at room temperature resulted in the formation of a single-phase martensite structure. The martensitic structure was confirmed to be orthorhombic (#alpha# double-prime) using X-ray diffraction. The water-quenched (WQ) specimens were subjected to aging treatments at temperatures of 823, 873, and 973 K for various lengths of time. Aging at 823 K for times between 24 and 100 hours did not bring about any noticeable change in the microstructure. Aging at 823 K for 200 and 300 hours resulted in the heterogeneous precipitation of s_2 silicide particles and thin films of #beta# sandwiched ...
A new metastable beta titanium alloy, Beta-CEZ, has been developed by CEZUS. This alloy was designed for use at moderate temperatures up to 450 C (840 F). Alloy requirements also included high mechanical strength, high fracture toughness and improved creep resistance as compared to existing beta alloys. The understanding of the relationships between processing/microstructure/mechanical properties in the alloy may lead to applications of such promising material in current and future airplanes. In this study, a combination of several forging routes, which included through-transus, hot-die and warm-die forging, with subsequent heat treatments were selected in order to evaluate the microstructure-mechanical property relationships. It was found that the recrystallized prior beta grain boundary alpha, characteristic of the through-transus forging process, lead to an improved tensile-fracture toughness ...
The T cell receptor is a fundamental mediator of the adaptive immune responses, since TR ab on T cells recognize foreign structures (peptides derived from processed antigens) bound to the major histocompatibility complex (MHC) on APC cells. In the present study, we report the cloning of six TRB chains cDNA sequences from gilthead sea bream (Sparus aurata), a fish of high economical impact in South Mediterranean aquaculture. The V-BETA domains have the canonical features of known teleost and mammalian TR V-BETA domains and have been divided in four different subgroups. A multiple alignment of the six sea bream TRB chains with other known TRB sequences was assembled and showed the conservation of the four cysteine residues involved in disulphide bonds and of some amino acids with an importan...
Spontaneous radiation emitted from relativistic electrons undergoing betatron motion in a plasma-focusing channel is analyzed, and applications to plasma wake-field accelerator experiments and to the ion-channel laser (ICL) are discussed. Important similarities and differences between a free electron laser (FEL) and an ICL are delineated. It is shown that the frequency of spontaneous radiation is a strong function of the betatron strength parameter a(beta), which plays a role similar to that of the wiggler strength parameter in a conventional FEL. For a(beta) > or approximately 1, radiation is emitted in numerous harmonics. Furthermore, a(beta) is proportional to the amplitude of the betatron orbit, which varies for every electron in the beam. The radiation spectrum emitted from an electron beam is calculated by averaging the single-electron spectrum over the electron distribution. This leads to a frequency broadening of ...
We have studied energy levels in "6"3Fe populated in the #beta#-decay of "6"3Mn. A new (preliminary) level scheme of "6"3Fe includes 10 excited states connected by 21 #gamma#-rays. The first excited states at 357 and 451 keV have the level half-lives of 110 ps and 780 ps, respectively. Three states, at 357, 451 and 1132 keV, are strongly #beta#-fed with log ft #approx# 5, while there is only a very week #beta#-feeding, if any at all, to the ground state. The new results imply that "6"3Fe departs from a simple shell model structure observed for heavier N = 37 isotones of "6"5Ni and "6"7Zn. (author)
We discuss the foundations of factor or regression models in the light of the self-consistency condition that the market portfolio (and more generally the risk factors) is (are) constituted of the assets whose returns it is (they are) supposed to explain. As already reported in several articles, self-consistency implies correlations between the return disturbances. As a consequence, the alpha's and beta's of the factor model are unobservable. Self-consistency leads to renormalized beta's with zero effective alpha's, which are observable with standard OLS regressions. Analytical derivations and numerical simulations show that, for arbitrary choices of the proxy which are different from the true market portfolio, a modified linear regression holds with a non-zero value $\\alpha_i$ at the origin between an asset $i$'s return and the proxy's return. Self-consistency also introduces ``orthogonality'' and ``normality'' conditions linking the ...
At the quark level there are basically two types of contributions of R-parity violating supersymmetry (Rep SUSY) to neutrinoless double beta decay: the short-range contribution involving only heavy virtual superpartners and the long-range one with the virtual squark and neutrino. Hadronization of the effective operators, corresponding to these two types of contributions, may in general involve virtual pions in addition to close on-mass-shell nucleons. From the previous studies it is known that the short-range contribution is dominated by the pion exchange. In the present paper we show that this is also true for the long-range Rep SUSY contribution. Therefore, we conclude that the Rep SUSY contributes to the neutrinoless double beta decay dominantly via charged pion exchange between the decaying nucleons.
#beta#-sialon ceramics of equal overall compositions but containing amorphous, partly crystalline and almost completely crystalline intergranular phase(s) have been oxidized in oxygen at 1350 deg C for 20 hours. The obtained weight gain curves do not follow the parabolic rate law (#DELTA#W/A_0)"2= k_pt + #beta#. To the extent that crystallization occurs in the oxide scale during the oxidation experiment, the amorphous cross section area through which oxygen most easily diffuses will decrease with time. A brief description of this new rate law is given, and the obtained oxidation curves will be discussed within that framework. 4 refs., 2 tabs., 2 figs.
Beta-SiAlON powders have been synthesized using natural clay containing kaolin and quartz by carbothermal reduction and nitridation (CRN), then beta-SiAlON bonded corundum multiphase materials have been sintered using the as prepared powders. The results indicated that both the holding time and sintering temperature are relatively significant in accordance with optimal analysis by orthogonal method. Reaction process can be briefly interpreted by means of X-ray Diffraction and Difference Temperature Analysis as well as phase diagram principle. Bending strength and bulk density were measured in SiAlON in situ bonded corundum materials with doped various sintering agents. Furthermore, the relevant mechanical properties and microstructure were discussed in detail.
We complete the effective potential calculation of the two-loop, top/bottom Yukawa corrections to the Higgs boson masses in the Minimal Supersymmetric Standard Model, by computing the O(at^2 + at*ab + ab^2) contributions for arbitrary values of the bottom Yukawa coupling. We also compute the corrections to the minimization conditions of the effective potential at the same perturbative order. Our results extend the existing O(at^2) calculation, and are relevant in regions of the parameter space corresponding to tan(beta) >> 1. We extend to the Yukawa corrections a convenient renormalization scheme, previously proposed for the O(ab*as) corrections, that avoids unphysically large threshold effects associated with the bottom mass and absorbs the bulk of the corrections into the one-loop expression. For large values of tan(beta), the new contributions can account for a variation of several GeV in the lightest Higgs boson mass.
The X-ray intensity ratio K_#beta#/K_#alpha# has been measured by using a 10 mCi "5"5Fe source (Mn K X-rays) and high resolution Si(Li) detector system coupled to a computer-controlled multichannel analyzer over the range of 15#<=#Z#<=#22. Correction have been made to the measured relative intensities (K_#alpha# and K_#beta# X-rays) for self-absorption in the sample, air, Be-window absorption and detection efficiency. The results are compared with those of other experiments and with the Scofield calculations. (author) 13 refs.; 3 figs.; 2 tabs.
The K/sub ..beta..//K/sub ..cap alpha../ X-ray intensity ratios are measured for Mn and Fe and for six other elements with Z lying in the range 49 less than or equal to Z less than or equal to 82 following electron capture decay and photon excitation using /sup 241/Am and /sup 57/Co sources. High-resolution Si(Li) and HpGe detector systems were used in the experiments. The dependence of K/sub ..beta..//K/sub ..cap alpha../ values on the mode of excitation in the case of Mn and Fe is attributed to chemical effects, while no such dependence is found for the high-Z elements.
DNA methylation is considered as a potential cause of aberrations in regulation of gene expression during carcinogenesis. Therefore, changes in DNA methylation patterns may be targets for chemoprevention. In the present study, we investigated effects of all-trans retinoic acid (ATRA), vitamin D3, and resveratrol alone and in combination with adenosine analogues: 2-chloro-2'-deoxyadenosine (2CdA) and 9-beta-d-arabinosyl-2-fluoroadenine (F-ara-A), on methylation and expression of retinoic acid receptor beta 2 (RARbeta2) in MCF-7 and MDA-MB-231 breast cancer cell lines. Alterations in methylation and expression levels after treatment of cells with the tested compounds were evaluated by methylation-sensitive restriction analysis (MSRA) and real-time PCR, respectively. RARbeta2 promoter in the ...
A study was made into microstructure and texture of cold rolled titanium alloy VT-35 with various hydrogen content aimed to reveal hydrogen influence on the mechanism of cold plastic deformation by rolling. Experiments were carried out using sheets 1.2 mm thick hydrogenated up to hydrogen concentrations from 0.06 to 0.554 mass. %. All specimens constituted a single-phase FCC #beta#-solid solution. It is shown that small hydrogen additions have a plasticizing effect on #beta#-titanium alloys in their cold rolling. The character of texture is dependent on hydrogen concentration and determined by deformation mechanism. 6 refs.; 5 figs.
Dense samples of #beta#-sialons (with z from 1 to 4) were pressuressly sintered for different time (15-240 minutes) and at relatively low temperature of 1600 C using single-phase #beta#-sialon powders synthesized by combustion nitridation. The samples were characterized using ultrasonic method for determination of elastic properties (E,G,#mu#). Also, hardness by Knoop and fracture toughness by Vickers indentation microfracture method was estimated. With increasing z number Young's modulus decreases from 293 to 179 GPa. Simultaneously Poisson ratio increases by about 30%. The highest values of hardness and fracture toughness were obtained for sialon with z equal to 1. (orig.).
The murine 3T3-L1 fibroblast under appropriate incubation conditions differentiates into an adipocyte phenotype. This 3T3-L1 adipocyte exhibits many of the morphologic, biochemical, and insulin-responsive features of the normal rodent adipocyte. Using quantitative electron microscopic (EM) autoradiography we find that, when /sup 125/I-insulin is incubated with 3T3-L1 adipocytes, the ligand at early times of incubation localizes to the plasma membrane of the cell preferentially to microvilli and coated pits. When the incubation is continued at 37 degrees C, /sup 125/I-insulin is internalized by the cells and preferential binding to the villous surface is lost. With the internalization of the ligand, two intracellular structures become labeled, as determined by the method of hypothetical grain analysis. These include large clear, presumably endocytotic, vesicles and multivesicular bodies. Over the first hour of incubation the labeling of these ...
A method for the introduction of N-(/sup 3/H)acetyl groups into glycosaminoglycans is described. The procedure is based on (/sup 3/H)acetylation of N-unsubstituted hexosamine residues by treating the polysaccharides with (/sup 3/H)acetic anhydride. Preparations of heparin and heparin sulfate were found to contain significant numbers of N-unsubstituted hexosamine residues, as isolates. In contrast, such units could not be detected in chondroitin sulfate, dermatan sulfate, or hyaluronic acid. These polysaccharides were therefore subjected to partial N-deacetylation by reaction with hydrazine in the presence of hydrazine sulfate. After treatment with (/sup 3/H)acetic anhydride, the specific activities of the resulting labeled polysaccharide preparations ranged between 0.1 X 10/sup 6/ and 0.6 X 10/sup 6/ cpm /sup 3/H/..mu..g of uronic acid. The /sup 3/H-labeled polysaccharide preparations did not differ significantly from the corresponding ...
Tumor imaging using radioiodinated monoclonal antibodies (Mab) suffered from rapid in vivo deiodination. This problem can be circumvented by covalent attachment of a bifunctional chelating group to the Mab followed by chelation with a suitable cationic radionuclide such as In-111. Competition of trace metal contaminants with In-111 for chelating sites, however, is known to lower the labeling yield. Since commercially available reagents may be contaminated with other trace metal ions, the effect of trace metals on Mab-DTPA chelation and the possibility of masking the trace metal effect on the In-111 labeling of Mab-DTPA were, therefore, investigated. Labeling yield of 93% was obtained when 1 mg (20mg/ml) of Mab F(ab')/sub 2/-DTPA (protein to DTPA ratio of --1) was allowed to incubate with 3 mCi In-111 in 2 ml acetate buffer (0.5M, pH 5.5) for 30 min. The yield was drastically decreased to 13-76% when the reactions were ...
An improved labeling procedure for peptides attached to organometallic 99mTc(III) '4+1' mixed-ligand complexes in which the radiometal is coordinated by a tripodal tetradentate chelator 2,2',2''-nitrilotriethanethiol (NS3) and a monodentate isocyanide ligand is presented. The labeling procedure was evaluated by the synthesis of [99mTc(NS3)(L2-RGD)]. The containing radiopharmaceutically interesting RGD-peptide cyclo[Arg-Gly-Asp-D-Tyr-Lys] was modified with 4-isocyanobutanoic acid (L2) as linker conjugated to N6-Lys to get the monodentate ligand L2-RGD. The structural identity of the 99mTc-conjugate was confirmed by comparison to a Re reference compound. The Tc- and Re-conjugates had matching retention times under identical HPLC conditions. The 99mTc-labeling was performed in a novel one-step procedure using the eluate of a 99Mo/99mTc generator, NS3, the isocyanide modified peptide, SnCl2, Na2EDTA, mannitol and ascorbic acid ...
A carrier-free radioiodinated phenylazide derivative of forskolin, 3-iodo-4-azidophenethylamido-7-O-succinyl-deacetyl-forskolin (({sup 125}I)IAPS-forskolin), has been shown to be a highly selective photoaffinity probe for the human erythrocyte glucose transported and the glucose transport proteins found in several mammalian tissues and cultured cells where the glucose transport protein is present at a low concentration. The photoincorporation of ({sup 125}I)IAPS-forskolin into these glucose transporters was blocked by D- (but not L-) glucose, cytochalasin B, and forskolin. In addition to labeling the mammalian glucose transport proteins, ({sup 125}I)IAPS-forskolin also labeled the L-arabinose transporter from E. coli. In muscle and adipose tissues, glucose transport is markedly increased in response to insulin. ({sup 125}I)IAPS-forskolin was shown to selectivity tag the glucose transporter in membranes derived from these cells. In addition, the ...
A carrier-free radioiodinated phenylazide derivative of forskolin, 3-iodo-4-azidophenethylamido-7-O-succinyl-deacetyl-forskolin (["1"2"5I]IAPS-forskolin), has been shown to be a highly selective photoaffinity probe for the human erythrocyte glucose transported and the glucose transport proteins found in several mammalian tissues and cultured cells where the glucose transport protein is present at a low concentration. The photoincorporation of ["1"2"5I]IAPS-forskolin into these glucose transporters was blocked by D- (but not L-) glucose, cytochalasin B, and forskolin. In addition to labeling the mammalian glucose transport proteins, ["1"2"5I]IAPS-forskolin also labeled the L-arabinose transporter from E. coli. In muscle and adipose tissues, glucose transport is markedly increased in response to insulin. ["1"2"5I]IAPS-forskolin was shown to selectivity tag the glucose transporter in membranes derived from these cells. In addition, the covalent ...
The synthesis of ["1"1C]phenobarbital, ["1"1C]pentobarbital and["1"1C]amobarbital labelled in the 5-[1-"1"1C]ethyl position is reported. The malonic esters R- CH(CO_2Et)_2 [R phenyl-, 1-methylbutyl-, and 3- methylbutyl- were alkylated with [1-"1"1C]ethyl iodide prepared from ["1"1C]carbon dioxide. Ring closure of the 2-[1-"1"1C]ethyl-labelled malonic esters with urea afforded 5-[1-"1"1C]ethyl-phenobarbital,-phenobarbital, -pentobarbital and -amobarbital synthesis times of 42-47 min, counted from ["1"1C] carbon dioxide. In typical syntheses starting with 3 GBq pentobarbitol and (81 mCi) ["1"1C]carbon dioxide, 150-215 MBq (4-6 mCi) were produced in 25-30% decay corrected -amobarbital radiochemical yields with radiochemical purities greater than 98%. (author).
The measurement of physiological parameters in man is possible with the help of positron emission tomography (PET) and radiopharmaceuticals labeled with short lived positron emitters as C 11, N 13, O 15 and F 18. With the use of this substances it is possible to make a tomographic map defining regional metabolic parameters in normal and diseased brain. This technique has therefore also be named 'in vivo autoradiography'. The possibility of applying C 11 or F 18 labeled deoxyglucose with PET for detecting regional and local changes in cerebral metabolic rate of glucose in brain development in children of 5 days to 1 year of age is discussed. Beyond this a relationship between cerebral metabolic rate of glucose, cerebral blood flow and cerebral metabolic rate of oxygen by use of this technique after inhalation of O 15 and C 11-labeled CO_2 is shown. Attention is drawn to the application of C 11-methyl-spiperone and PET to ...
The radioiodine-labeled amines currently available as brain-imaging agents, based on our previous work and that of others, are prepared either by exchange labeling or by direct iodination of a protected intermediate. The intrinsic slowness of these processes limits their potential for use with the positron-emitting 122I, as it has a half-life of only 3.6 min. This isotope has advantages of a low dose to the patient and availability from a generator containing the parent 20-h 122Xe. To develop a radiopharmaceutical in which 122I could be utilized, we prepared a number of secondary and tertiary amines (maintaining the 2,5-dimethoxy substitution pattern which allows direct iodination at the 4-position) with 131I. The organ distributions of these compounds were studied, and the best properties were found in the N,N-dimethyl homologue (2,5-dimethoxy-N,N-dimethyl-4-iodoamphetamine). This compound was successfully synthesized in a matter of seconds, ...
The radioiodine-labeled amines currently available as brain-imaging agents, based on our previous work and that of others, are prepared either by exchange labeling or by direct iodination of a protected intermediate. The intrinsic slowness of these processes limits their potential for use with the positron-emitting 122I, as it has a half-life of only 3.6 min. This isotope has advantages of a low dose to the patient and availability from a generator containing the parent 20-h 122Xe. To develop a radiopharmaceutical in which 122I could be utilized, we prepared a number of secondary and tertiary amines (maintaining the 2,5-dimethoxy substitution pattern which allows direct iodination at the 4-position) with 131I. The organ distributions of these compounds were studied, and the best properties were found in the N,N-dimethyl homologue (2,5-dimethoxy-N,N-dimethyl-4-iodoamphetamine). This compound was successfully synthesized in a matter of seconds, ...
The contribution of platelets and clotting factors in thrombosis on cardiovascular prostheses had been quantified with several tracers. Thrombus formation in vivo could be measured semiquantitatively in animal models and patients with indium-111, Technetium-99m labeled platelets, iodine-123, iodine-131 labeled fibrinogen, and In-111 and Tc-99m labeled antibody to the fibrinogen-receptor on the platelet- membrane, or fibrin. The early studies demonstrated that certain platelet-inhibitors, e.g. sulfinpyrazone, aspirin or aspirin- persantine increased platelet survival time with mechanical valves implanted in the baboon model and patients. Thrombus localization by imaging is possible for large thrombus on thrombogenic surface of prosthesis in the acute phase. The majority of thrombus was found in the sewing ring (Dacron) in the acute phase in both the mechanical and tissue valves. The amount of retained thrombus in both ...
Sucrose and mannitol are major photosynthetic products and translocates in celery. Assimilate partitioning and transport were studied by pulse-labeling leaves with /sup 14/CO/sub 2/ followed by different length chases in ambient air. After a 2 h chase in the light there was more /sup 14/C in sucrose than mannitol in source leaves and their petioles. In contrast after a 2 h dark chase leaves contained more /sup 14/C in mannitol than sucrose but petioles had more /sup 14/C in sucrose than mannitol. After a 15 h chase (6 h light; 9 h dark) labeled sucrose was higher in source petiole vascular bundles than in adjacent parenchyma tissue but label in glucose and fructose was higher in the parenchyma tissue. After the 15 h chase most of the /sup 14/C remaining in developing sink leaves and their petioles was in mannitol. Although in the light mannitol:sucrose ratios are the same in leaf and petiole tissues, in the dark sucrose is ...
The radiochemical purity of the cobalt-57 complex of bleomycin could be enhanced by adjusting the pH of the final product to a value between 5 and 6. This radiopharmaceutical appeared to have better tumor visualizing properties compared to the not neutralized preparation. The clinical use of the cobalt-57 bleomycin complex is however limited by the long physical half-life of the label, causing a risk of radioactive contamination. It appeared to be possible to label bleomycin with radioactive cations ("1"1"1In"3"+, sup(99m)Tc"4"+, "1"9"7Hg"2"+ and "6"7Cu"2"+) having suitable gamma ray energies and short half-lifes. These bleomycin complexes showed a high radiochemical purity judged by their behaviour on thin layer chromatography, paper chromatography, and electrophoresis, but their application as tumor visualizing radiopharmaceutical turned out to be disappointing compared with cobalt-57 bleomycin. (orig.).
Gel filtration of human erythrocyte (RBC) lysate incubated with labeled thyroxine (Tu) or triiodothyronine (Tt) revealed co-elution of a major iodothyronine-binding fraction (R-2) and hemoglobin. Solutions of purified human hemoglobin and Tt also showed co-elution of hormone and hemoglobin. Because hematin and protoporphyrin were shown to bind labeled Tt, the oxygen-binding site on hemoglobin was excluded as the site of iodothyronine-hemoglobin interaction. Analysis of hormone binding by heme and globin moieties showed Tt binding to be limited to the heme fraction. Addition of excess unlabeled Tt to hemoglobin or heme incubated with labeled Tt indicated 75% to 90% of hormone binding was poorly dissociable. These observations suggested that the presence of hemoglobin in RBC lysate or in serum could influence the measurement of Tu and Tt by specific radioimmunoassay (RIA). Subsequent studies of the addition to serum of human ...
The aim of this study was to assess the utility of a radioimmunoconjugate containing a lead radionuclide for therapy and scintigraphy applications. The radioimmunoconjugate evaluated consisted of a bifunctional DOTA ligand and monoclonal antibody (MAb) B72.3 using athymic mice bearing LS-174T tumors, human colon carcinoma xenografts. In the studies reported here, the lead-203-DOTA complex itself was first demonstrated to have in vivo stability. MAb B72.3 was then conjugated with the DOTA ligand and labeled with "2"0"3Pb, and the immunoreactivity of B72.3 was maintained. The localization of the radioimmunoconjugate to tumor tissue and other select organs paralleled that of DOTA-"1"2"5I-B72.3, suggesting a similar metabolic pattern of the two radioimmunoconjugates. Thus, the DOTA-metal complex does not alter the behavior of the radioimmunoconjugate. Tumor localization of the "2"0"3Pb-DOTA-B72.3 conjugate was demonstrated with biodistribution studies as well as ...
The effects of mouse epidermal growth factor (EGF) on bone formation and resorption were examined in male mice. EGF administration (2-200 ng.g-1.day-1 ip for 7 days) induced a dose-dependent rise in plasma EGF levels that remained within physiological range. Histomorphometric analysis of caudal vertebrae showed that EGF (20 and 200 ng.g-1.day-1) reduced the endosteal matrix and mineral appositional rates after 5 days of treatment as measured by double (3H)proline labeling and double tetracycline labeling, respectively. This effect was transitory and was not observed after 7 days of EGF administration. EGF administered for 7 days induced a dose-dependent increase in the periosteal osteoblastic and tetracycline double-labeled surfaces. At high dosage (200 ng.g-1.day-1) EGF administration increased the osteoclastic surface and the number of acid phosphatase-stained osteoclasts, although plasma calcium remained normal. The ...
Clove (Caryophyllus aromaticus L.) has been used for clinical procedures. Blood constituents labeled with technetium-99m (99mTc) are used in nuclear medicine. The aim of this work was to evaluate the effects of clove extract on the labeling blood constituents with 99mTc and on the morphology of red blood cells. Blood samples were incubated with clove, stannous chloride and 99mTc. Plasma, blood cells, insoluble fractions of plasma and blood cells were separated. The radioactivity was counted and percentage of radioactivity (%ATI) to each blood fraction was calculated. The shape and morphometric parameter (perimeter/area ratio) were evaluated. Clove extract altered significantly (p<0.05) the %ATI of blood constituents and the shape of red blood cells without modifying the perimeter/area ratio. The results indicate that clove extract presents chemical compounds that interfere with the radiolabeling of blood constituents and alter the ...
Dynamics and metabolism of sugars translocated into the fruit region were investigated in tomato using {sup 14}C-labelled compounds. The translocation substance in tomato is thought to be sucrose, but the amount of sucrose in its fruit is very small. Therefore, the degradation of sucrose in the fruit and its translocation to the fruit was investigated. The sucrose was digested into hexoses such as glucose, fructose, etc. and the degradation rate was considerably low. In the stage of thickening growth, sucrose was more extensively converted into other substances except for sugars compared with the coloring stage. Then, {sup 14}C-labelled fructose was given through its gynophore to investigate the degree of reproduction to sucrose. The fructose level in the fruit reached the platean by 48 hrs after the addition and gradually decreased. The radioactivities were detected in sugars, organic acids and other alcohol soluble substances, etc. These ...
Six men were fed a diet composed of conventional foods with all bread as whole wheat bread. Intrinsically labeled "6"5Cu bread (containing 6.5 ppm Cu and 48 atom % "6"5Cu) was substituted for unlabeled bread for 3 days, and stools were collected for 24 days. Extrinsically labeled bread was then substituted for 3 days and another 24-day stool collection made. "6"5Cu excretion was measured by mass spectrometry. Mean Cu intake was 1.10 mg of Cu/day. Average Cu balance was /minus/0.06 /+-/ 0.08 mg/day. Average absorption of the intrinsic copper was 72.2 /+-/ 9.3% and of extrinsic Cu 64.2 /+-/ 5.8%. The ratio of extrinsic to intrinsic absorption was 0.906 /+-/ 0.164. Absorption of intrinsic and extrinsic tracers did not differ significantly (p > 0.05) by a paired t-test, and the ratio (E/I) was not significantly different from 1. Use of extrinsic Cu tracers to assess Cu absorption is supported by these results.
The circulation in microvascularized rib grafts has been compared with that in conventional rib grafts and in those augmented by a direct vascular bundle implantation into the bone grafts. A new experimental model has been designed to correlate vascular perfusion, bone scan patterns, tetracycline labeling, and histological findings in these bone grafts. Posterior microvascularized rib grafts were found to have a circulatory pattern identical to that of the normal rib. Failed microvascularized rib grafts were revascularized more slowly than conventional rib grafts. Vascular bundles implanted into rib grafts remained patent and increased the rate of revascularization. The stripping or preservation of periosteum had no observable effects on the rate or pattern of conventional rib graft revascularization. The circulation in rib grafts was accurately reflected in technetium 99 bone scans, as was the patency of the anastomoses of microvascularized rib grafts and of ...
Metabolic carbon labelling experiments enable a large amount of extracellular fluxes and intracellular carbon isotope enrichments to be measured. Since the relation between the measured quantities and the unknown intracellular metabolic fluxes is given by bilinear balance equations, flux determination from this data set requires the numerical solution of a nonlinear inverse problem. To this end, a general algorithm for flux estimation from metabolic carbon labelling experiments based on the least squares approach is developed in this contribution and complemented by appropriate tools for statistical analysis. The linearization technique usually applied for the computation of nonlinear confidence regions is shown to be inappropriate in the case of large exchange fluxes. For this reason a sophisticated compactification transformation technique for nonlinear statistical analysis is developed. Statistical analysis is then performed by computing ...
The kinetics of {sup 14}C-photosynthate import by developing wheat grains was followed after pulse-labeling the flag leaf with {sup 14}CO{sub 2}. Samples were collected from four successive points along the transport pathway to and within the grain: exuding aphid stylets on the peduncle, exuding grain pedicels, the grain crease tissues, and the liquid contents of the endosperm cavity. In addition, microautoradiographs were prepared of the grain crease tissues during movement of the {sup 14}C pulse into the grain. At all times, sucrose accounted for 93 to 97% of the total {sup 14}C present at all four sampling sites. The main features of the {sup 14}C kinetics could be accounted for by a simple compartmental model consisting of sucrose pools in series. Microautoradiographs of the crease tissues showed fairly uniform labeling of vascular parenchyma at all times, with a sharp gradient in labeling across the chalaza to the ...
The unknown {beta}-decay half-lives of 22 isotopes far off stability (5 < T{sub Z} < 10) in the region from Ti to Ni were measured at GSI, Darmstadt. The nuclei were produced in a fragmentation reaction of 500 A.MeV {sup 86}Kr-projectile impinging on a thick Be target. The isotopes of interest were separated and identified with the fragment separator, FRS, by a combination of B{rho},Z, and ToF techniques. An additional range separation was performed by a selective implantation into granular detectors. The spatial and time correlations of the implant with the consecutively detected {beta}-particles were used to determine the unknown half-lives. For nuclei far off stability, {beta}-decay chains were measured and analyzed as well, leading to an even more reliable evaluation of the lifetimes. The large discrepancies found between the measured and the theoretical values emphasize that most recent theoretical work is not an ...
Thoracic aortic aneurysms (TAAs) are potentially devastating, and due to their asymptomatic behavior, pose a serious health risk characterized by the lack of medical treatment options and high...Full Text Available
BackgroundPerichondrium is recognized as a tissue with chondrogenic potential yielding cells which can be used for osteochondral repair. Factors which influence the proliferative...Full Text Available
The quantum $N$-body problem is studied in the context of nonrelativistic quantum mechanics with a one-dimensional deformed Heisenberg algebra of the form $[\\hat x,\\hat p]=i(1+\\beta \\hat p^2)$, leading to the existence of a minimal observable length $\\sqrt\\beta$. For a generic pairwise interaction potential, analytical formulas are obtained that allow to estimate the ground-state energy of the $N$-body system by finding the ground-state energy of a corresponding two-body problem. It is first shown that, in the harmonic oscillator case, the $\\beta$-dependent term grows faster with $N$ than the $\\beta$-independent one. Then, it is argued that such a behavior should be observed also with generic potentials and for $D$-dimensional systems. In consequence, quantum $N$-body bound states might be interesting places to look at nontrivial manifestations of a minimal length since, the more particles are ...
The rolB gene of Agrobacterium rhizogenes, whose expression stimulates the formation of roots by transformed plant tissues and other growth alterations in transgenic plants, codes for a beta-glucosidase...Full Text Available
The rolC gene of Agrobacterium rhizogenes, which drastically affects growth and development of transgenic plants, codes for a cytokinin-beta-glucosidase. Indeed, rolC protein expressed in Escherichia...Full Text Available
Treatment of male rat pups from five to 34 days of age with dihydrotestosterone or 5 alpha-androstane-3 alpha, 17 beta-diol, resulted in reduced testicular size at 35 days of age. This appeared to be...Full Text Available
The effect of one on-ramp (entry) and one off-ramp (exit) is investigated numerically in one dimensional-cellular automaton traffic flow model, with open boundary conditions, using parallel dynamics. Our aim in this paper is to study how the injecting rates $\\alpha$ and $\\alpha_{0}$ and the extracting rates $\\beta$ and $\\beta_{0}$ acts on the density and flux of cars in one dimensional road. The priority of occupation at entry site $i_{1}$ (moving at exit site $i_{2}$) is attributed to the particle which entered (absorbed) in the chain. Phase diagrams in ($\\beta_{0},\\alpha_{0}$), and ($\\beta,\\alpha_{0}$) plans are established. For $\\alpha=0.1$, they show three different topologies in the flow behaviour. The first one correspond to the presence of four regions, by varying $\\alpha_{0}$; namely low density phase (LDP), intermediate density phase (IDP), plateau current phase (PCP) and high density ...
Background:Children suffering from beta-thalassemia major require repeated blood transfusions which may be associated with dangers like iron overload and contraction of...Full Text Available
It has been discovered that the presence of MoO/sub 3/ lowers the ..cap alpha..-..beta.. transition in Sb/sub 2/O/sub 4/ from 935 to 850/sup 0/C with concurrent dissolution of Mo in the high-temperature (..beta..) form. The structure of Mo-doped ..beta..-Sb/sub 2/O/sub 4/ has been investigated by powder neutron diffraction, extended X-ray absorption fine structure (EXAFS) and Raman spectroscopies, and scanning-electron microscopy (SEM). Cell parameters: a = 12.0571 (12) A, b = 4.8335 (1) A, c = 5.3838 (6) A, ..beta.. = 105.579 (5)/sup 0/, monoclinic, space group C2/c, Z = 4. Combining the results of these techniques leads to the hypothesis that Mo is located interstitially within channels of electron density in the Sb/sub 2/O/sub 4/ structure with concurrent vacancy of two Sb/sup III/ atoms. There is no apparent oxygen deficiency in the resulting structure. 25 references, 6 figures, 3 tables.
BackgroundIn β-thalassemia, profound anemia and severe hemosiderosis cause functional and physiological abnormalities in various organ systems. In recent years, there have...Full Text Available
The H+-translocating inorganic pyrophosphatase (H+-PPase) associated with vesicles of the vacuolar membrane (tonoplast) isolated from beet (Beta vulgaris L.) is...Full Text Available
RADIANT{trademark} is manufactured by United States Surgical Corporation, Vascular Therapies Division, (formerly Progressive Angioplasty Systems). The system comprises a liquid {beta}-radiation source, a shielded isolation/transfer device (ISAT), modified over-the-wire or rapid exchange delivery balloons, and accessory kits. The liquid {beta}-source is Rhenium-188 in the form of sodium perrhenate (NaReO{sub 4}), Rhenium-188 is primarily a {beta}-emitter with a physical half-life of 17.0 hours. The maximum energy of the {beta}-particles is 2.1 MeV. The source is produced daily in the nuclear pharmacy hot lab by eluting a Tungsten-188/Rhenium-188 generator manufactured by Oak Ridge National Laboratory (ORNL). Using anion exchange columns and Millipore filters the effluent is concentrated to approximately 100 mCi/ml, calibrated, and loaded into the (ISAT) which is subsequently transported to the cardiac ...
An enzyme active against carboxymethyl cellulose (CMC) was purified from the stationary-phase-culture supernatant of Clostridium josui grown in a medium containing ball-milled cellulose. The purification...Full Text Available
Synthesis of Eu-doped #beta#- and 15R-SiAlONs was studied by the ammonia nitridation of precursors derived from an #alpha#-Si_3N_4 fine powder dispersed in aluminum glycine gel with various Si/Al ratio and post-annealing in a nitrogen pressure furnace. The largest amount of #beta#-SiAlON was observed in the product at 1750 deg. C for Si/Al = 1/1 with small amounts of both #alpha#- and 15R-SiAlON impurities. The product showed two emissions at around 420 nm and 560 nm. The emission intensities decreased with increasing amount of #beta#-SiAlON. The former and latter emissions were assigned to Eu"2"+ in the 15R- and #alpha#-SiAlONs impurities. A mixture of Eu-doped 15R-SiAlON with #alpha#-Al_2O_3 impurity was obtained for Si/Al = 1/6, using AlN together with Al(NO_3)_3.9H_2O in a 2/1 atomic ratio as the aluminum source. It showed a bluish-white emission at 450 nm under 254 nm radiation.
The densification of #alpha#"1-and #alpha#"+#beta#"1-sialon ceramics has been studied by means of in situ dilatometry. It is seen that the densification is greatly affected by the reaction sequences and the grain growth. The formation and densification of sialons start simultaneously as the dissolution of nitrides into the oxide eutectic liquid phase occurs. The formation of sialons is complete at 1800 deg C., while full densification can only be obtained by using gas pressure sintering. The typical microstructure of both #alpha#"'-and mixed #alpha#'+#beta#'-sialon ceramics consists of a crystalline phase of sialons and a small fraction of amorphous phase at grain boundaries. Vickers hardness (HV0.5) was measured by using the indentation technique, and the biaxial bending strength (#sigma#_b_i) was determined with the 'ball-on-ring' test. Fracture toughness was determined by using both the indentation and single-edged notched beam techniques. ...
Zinc molybdate (ZnMoO4) single crystals were grown for the first time by the Czochralski method and their luminescence was measured under X ray excitation in the temperature range 85-400 K. Properties of ZnMoO4 crystal as cryogenic low temperature scintillator were checked for the first time. Radioactive contamination of the ZnMoO4 crystal was estimated as <0.3 mBq/kg (228-Th) and 8 mBq/kg (226-Ra). Thanks to the simultaneous measurement of the scintillation light and the phonon signal, the alpha particles can be discriminated from the gamma/beta interactions, making this compound extremely promising for the search of neutrinoless Double Beta Decay of 100-Mo. We also report on the ability to discriminate the alpha-induced background without the light measurement, thanks to a different shape of the thermal signal that characterizes gamma/beta and alpha particle interactions.
A powder mixture of #alpha#-Si_3N_4, Al_2O_3, and TiO_2 was hot-pressed using different sintering cycles to search for an optimum in situ formed #beta#-O-sialon-TiN composite. The impulse excitation technique (IET), high-temperature X-ray diffraction (HTXRD), and scanning electron microscopy (SEM) were used to investigate the microstructure. Below the temperature of 1300 deg. C, the high-temperature internal friction (Q "-"1) decreases with the increase of sintering temperature, whereas the density of the material increases with the increase of sintering temperature. At a sintering temperature higher than 1850 deg. C, the ceramic could not be densified and O-sialon was not formed. Also, the mechanical properties of ceramics hot-pressed using different sintering cycles were assessed. The ceramic hot-pressed at 1700 deg. C for 10 min displays a combination of high hardness and good fracture toughness, due to an optimum combination of ...
BackgroundIn this study we investigated the predictability of three thermodynamic quantities related to complex formation. As a model system we chose the host-guest complexes of...Full Text Available
The most abundant minor hemoglobin component of human hemolysate is Hb A1c, which has glucose bound to the N-terminus of the beta chain by a ketoamine linkage. Hb A1c is formed slowly and continuously throughout the 120 day lifespan of the red cell. It can be synthesized in vitro by incubating purified hemoglobin with 14C-glucose. Other minor components, Hb A1a1 and Hb A1a2 are adducts of sugar phosphates at the N-terminus of the beta chain. Hb A1b contains an unidentified nonphosphorylated sugar at the beta N-terminus. In addition, a significant portion of the major hemoglobin component (Hb Ao) is also glycosylated by a glucose ketoamine linkage at other sites on the molecule, including the N-terminus of the alpha chain and the epsilon-amino group of several lysine residues on both the alpha and the beta chains. The results indicate that the interaction of glucose and hemoglobin is rather nonspecific ...
The beta titanium alloy, however, can be d_,_wn. _,plusor minus 0.010-inch_after the parts have been cold. Its availability in strip lengths and its good ...
This study deals with the torsional response of Ti-8823 and 18Ni (200) maraging steel. The effect of different heat treatments and the subsequent change in microstructure are investigated. In the case of the Ti-8823, a comparison was made between the solu...
Two bacteriolytic enzymes secreted by Achromobacter lyticus M497-1 were purified and identified as being very similar (considering their amino acid composition and N-terminal sequence) to alpha- and...Full Text Available
Environmental surveys to provide base-line data for assessing the potential impact of the operation of Wolseong NPP on marine ecosystems were performed at 3-month intervals in 1981. Physico-chemical properties of seawater and gross beta activities in seaw...
A case of {beta}-thalassemia intermedia with spinal cord compression due to extramedullary hematopoiesis, which was successfully treated by blood transfusion, is presented. Emphasis was made on the MRI appearance of extramedullary hematopoiesis on different pulse sequences. The theories that aimed to explain the involvement of the epidural space by extramedullary hematopoiesis are discussed.
Type II collagen-induced arthritis (CIA) in mice is an autoimmune experimental model for rheumatoid arthritis. Susceptibility to CIA is associated with certain major histocompatibility complex class...Full Text Available
K{beta}-to-K{alpha} X-ray intensity ratios of Ti, V, Cr, and Co in pure metals and their disilicide compounds have been measured following excitation by 59.54 keV {gamma}-rays from a 200 mCi {sup 241}Am point-source. The K{beta}-to-K{alpha} intensity ratios of all these metals in the disilicide compounds are found to be less than the corresponding ratios for pure metals. Comparison of the measured K{beta}-to-K{alpha} intensity ratios for the disilicides and pure metals with the multiconfiguration Dirac-Fock calculations indicates increase of the 3d electron populations of Ti, V, Cr, and Co in the disilicides from their pure metal values suggesting the rearrangement of electrons between 3d and 4s states of the individual metal atom. This rearrangement is found to be opposite to that observed in our previously reported work on NiSi{sub 2} and CuSi{sub 2}.
K#beta#-to-K#alpha# X-ray intensity ratios of Ti, V, Cr, and Co in pure metals and their disilicide compounds have been measured following excitation by 59.54 keV #gamma#-rays from a 200 mCi "2"4"1Am point-source. The K#beta#-to-K#alpha# intensity ratios of all these metals in the disilicide compounds are found to be less than the corresponding ratios for pure metals. Comparison of the measured K#beta#-to-K#alpha# intensity ratios for the disilicides and pure metals with the multiconfiguration Dirac-Fock calculations indicates increase of the 3d electron populations of Ti, V, Cr, and Co in the disilicides from their pure metal values suggesting the rearrangement of electrons between 3d and 4s states of the individual metal atom. This rearrangement is found to be opposite to that observed in our previously reported work on NiSi_2 and CuSi_2.
The possibility of rapid heat treatment (RHT) application to titanium castings has been studied. It was shown that such treatment provides a significant improvement of intragrain structure and mechanical properties of cast ({alpha}+{beta})-titanium alloys. ((orig.))
The contents of immunoreactive somatostatin (IR-SRIF) and ..beta..-endorphin (IR-..beta..-EP) in 12 brain regions were examined in rats exposed neonatally to propylthiouracil (PTU) through the mother's milk. Since the dose of PTU used in this study is lower than the usual dose employed to induce hypothyroidism, a milder form of neonatal hypothyroidism resulted. This conclusion is supported by the only mild subnormal growth of rats to adulthood and serum T/sub 4/ and T/sub 3/ concentrations in the normal range. Adult rats treated with PTU neonatally had significantly higher IR-SRIF contents in several brain regions compared to controls, whereas IR-..beta..-EP levels were not significantly different in most regions. The results indicate that even mild hypothyroidism during early postnatal development causes permanent impairment of brain function, which manifests itself in part by an altered brain content of IR-SRIF.
The diagnosis of dialysis-related amyloid (AB-amyloid) has been based usually on clinical and radiological criteria. Following the discovery that beta 2-microglobulin was the major protein of this amyloid, we isolated and radiolabelled uremic plasma beta 2-microglobulin. After intravenous injection, gamma-camera images of selected joint areas were obtained from 42 patients who were on regular hemodialysis therapy. Positive scans involving the shoulder, hip, knee and carpal regions were found in 13 of 14 patients treated for more than 10 years and 10 of 16 patients treated for 5 to 10 years. Patients treated for less time had negative scans. Specificity was indicated by negative scans in non-amyloid inflammatory lesions in control hemodialysis patients. Up to 48-fold tracer enrichment was detected in excised AB-amyloid containing tissue as compared to amyloid-free tissue. These findings suggest that circulating radiolabelled ...
The Green-Chasman lattice, which is the basis for both NSLS storage rings, was conceived with insertion devices in mind. Long, field-free straight sections were provided in the design. The electron optics were chosen so that these sections had zero dispersion and the effects of new magnetic structures placed in these regions would have minimal effect on the emittance of the electron beam. This design concept has been followed by all high-brightness rings which were built subsequent to the NSLS. The X-Ray Ring straight sections also have a very small vertical {beta} function, in addition to the zero dispersion. This was done to optimize the brightness of wiggler sources. There is a further benefit however. The {beta} function determines the beam size and divergence at a particular point in the storage ring lattice. The size is proportional to {radical}{beta} and the divergence is proportional to ...
Background: Hypoparathyroidism is one of the most important endocrine complications of thalassemia major. This study was conducted to evaluate the prevalence of intracerebral calcifications in patients with thalassemia with and without hypoparathyroidism. Methods: 47 beta-thalassemia patients with hypoparathyroidism underwent a brain CT scan to investigate the presence and extent of intracerebral calcification. 30 age- and sex-matched beta-thalassemic patients with normal parathyroid function who had undergone brain CT for headache, or some other minor neurologic problems were also enrolled in the study serving as controls. The amount of intracerebral calcification, hematologic parameters, and some clinical findings were compared between both groups. Results: Intracerebral calcification was present in 54.2% of beta-thalassemia patients with hypoparathyroidism. The most frequent sites of calcification were basal ganglia, and ...
Ti-15Mo-2.7Nb-3Al-0.2Si (Timetal-21S), a metastable #beta#-titanium alloy, is a candidate material for titanium matrix composite structures in hydrogen-fueled hypersonic planes because of its excellent formability and adequate mechanical properties in the 500--800 C temperature range. The alloy is strengthened through the precipitation of fine #alpha# particles in the #beta# matrix. The mechanical properties and microstructures are controlled by a solutionizing/aging heat treatment. A major concern in using titanium alloys in hydrogen service is the embrittlement caused by the precipitation of hydrides. It is believed that the large solubility of hydrogen in the #beta#-phase would preclude the precipitation of hydrides in Beta titanium alloys, especially at low hydrogen pressures. However, depending on the hydrogen content, a shift in the ductile/brittle transition temperatures to levels much higher ...
The {beta}-Si{sub 3}N{sub 4}w/6061 Al composite was fabricated by the squeeze casting and extruded with the extrusion ratios of 44 and 100 at 773 K. Its tensile strength and superplastic characteristics were investigated and the following results were obtained: (1) the {beta}-Si{sub 3}N{sub 4}w/6061 Al composite exhibits the tensile strengths of about 400 MPa at room temperature and of about 250 MPa at 773 K; (2) the m value of the composite pulled at 818 K is 0.33 in the strain rate range from 0.02 up to 1.0 s{sup {minus}1}; (3) the total elongation of the composite becomes about 173 % at the strain rate of 0.02 s{sup {minus}1} even in the case of the high volume fraction of 0.25; (4) no reaction product on the surface of {beta}-Si{sub 3}N{sub 4} whisker after removing a matrix by etching was detected except AlN; (5) the fracture surface of the composite includes the melt matrix and small filaments, which shows that ...
The usually low wear resistance of titanium materials can be increased by the thermochemical surface treatment nitriding. In result of comparative investigations of gas and plasma nitriding it will be shown that it is possible to obtain a specific variation of the properties in the highly stressed case by means of these both technologies on example of the (#alpha#+#beta#) alloy Ti-6Al-4V. Gas and plasma nitriding was carried out in the temperature range from 650 to 800 C over 4 to 48 h in different gas atmospheres, i.e. 100% NH_3 (gas), 100% N_2 (gas and plasma), 20% H_2 + 80% N_2 and 20% Ar + 20% H_2 (plasma). The temperature range was fixed in the middle of (#alpha#+#beta#) region, because the core properties are influenced negative in the field of #beta#-transustemperature. The relations between the applied nitriding technologies, the layer structure (chemical, phases, geometrical) and selected layer properties ...
In the synthesis of the peptidyl-polymer corresponding to the sequence (57-100) of the ..beta.. chain of human hemoglobin on Teflon with radiationally grafted polystyrene a comparative study was made of different methods of fragment condensation. It was shown that the most effective methods are azide condensation and condensation with the use of complex F.
In the synthesis of the peptidyl-polymer corresponding to the sequence (57-100) of the #beta# chain of human hemoglobin on Teflon with radiationally grafted polystyrene a comparative study was made of different methods of fragment condensation. It was shown that the most effective methods are azide condensation and condensation with the use of complex F.
We present a showcase for deriving bounds on the neutrino masses from laboratory experiments and cosmological observations. We compare the frequentist and Bayesian bounds on the effective electron neutrino mass m_beta which the KATRIN neutrino mass experiment is expected to obtain, using both an analytical likelihood function and Monte Carlo simulations of KATRIN. Assuming a uniform prior in m_beta, we find that a null result yields an upper bound of about 0.17 eV at 90% confidence in the Bayesian analysis, to be compared with the frequentist KATRIN reference value of 0.20 eV. This is a significant difference when judged relative to the systematic and statistical uncertainties of the experiment. On the other hand, an input m_beta=0.35 eV, which is the KATRIN 5sigma detection threshold, would be detected at virtually the same level. Finally, we combine the simulated KATRIN results with cosmological data in the form of ...
The results of a study of the expression of embryonic hemoglobin genes in mice which show an imbalance of alpha and non-alpha chain synthesis are reported. (ACR)
Broth disk elution procedures represent one of the most practical means for clinical laboratories to perform routine antibiotic susceptibility tests on anaerobic bacteria. The accuracy of five disk...Full Text Available
The influence of pretreatment of Escherichia coli and Staphylococcus aureus with sub-MICs of the new beta-lactam antibiotic imipenem on phagocytosis and killing by murine peritoneal macrophages and...Full Text Available
The overall objective of this research work was to prepare hydrocracking catalysts using amorphous silica-alumina (ASA) supports in combination with USY and {beta}-zeolites. Three supports: namely silica-alumina, USY and {beta}-zeolites were selected to prepare the extrudates using AP-1 as a binder, while two metal pairs: namely Ni-W and Ni-Mo were loaded on the extrudates through co-impregnation using incipient wetness technique. The catalysts were then calcined at 550C for 2h. The catalysts were tested in a fixed-bed flow reaction system for their activity, using desulfurized vacuum gas oil (DS-VGO) as a feedstock. The catalytic evaluation results of the catalysts showed that {beta}-zeolite alone and in combination with the ASA used in this study, has a potential as a support for developing heavy oil hydrocracking catalysts. A balance of weak and strong acidities of {beta}-zeolite provides control ...
In the decoupling limit M_A_"0"2>>M_Z"2, the heavy CP-even, CP-odd, and charged Higgs boson masses are nearly degenerate, sin(#beta#-#alpha#) approaches 1, and the lightest CP-even Higgs boson almost displays the same properties as the standard model Higgs boson. But the top and bottom squark sectors can change this pattern through radiative corrections. We find that there are parameter regions at small and moderate tan #beta# in the minimal supersymmetry standard model under experimental constraints of (g-2)_#mu#, b#->#s#gamma#, and lower bounds of Higgs boson and sparticle masses, where sin"2(#beta#-#alpha#) is damped (say below 0.8), which has a significant effect on Higgs couplings g_h_"0_V_V(V=W"#+-#,Z"0) and g_h_"0_#gamma#_#gamma#. We discuss its impact on the lightest CP-even Higgs boson production at #gamma##gamma# colliders.
Activation of beta-adrenergic or muscarinic acetylcholine receptors expressed in transfected cells or epidermal growth factor receptors in human keratinocytes produces 15% to 200% changes in cellular...Full Text Available
The efficacy of beta-lactam antibiotics and amikacin alone and in various combinations against Pseudomonas aeruginosa was studied in a rabbit model simulating a closed-space infection in a locally neutropenic...Full Text Available
Three nucleic acid probes, two for autotrophic ammonia-oxidizing bacteria of the beta subdivision of the class Proteobacteria and one for alpha subdivision nitrite-oxidizing bacteria, were developed...Full Text Available
Clostridium perfringens produces numerous toxins, which are responsible for severe diseases in man and animals. Delta toxin is one of the three hemolysins released by a number of C....Full Text Available
K_#beta#/ K_#alpha# x-ray intensity ratio of chromium were measured in different chromium compounds. The results show the variation of the intensity ratio as a function of the chemical environment around the metal ion. (author)
Investigations of psychrotrophic microorganisms have been limited even though the dominant environment of the Earth is cold and enzymes with high activities at low temperatures could have commercial...Full Text Available
This cross-sectional study evaluated the association between radiographic evidence of alveolar bone loss and the concentration of host-derived bone resorptive factors (interleukin-1 beta, tumor...Full Text Available
Progranulin haplo-insufficiency is a main cause of frontotemporal lobar degeneration (FTLD) with TDP-43 aggregates. Previous studies have shown that sortilin regulates progranulin trafficking and is...Full Text Available
Like other halophytic chenopods, sugar beet (Beta vulgaris L.) can accumulate high betaine levels in shoots and roots. N,N,N-trimethylglycine impedes sucrose crystallization...Full Text Available
Molecular chaperones protect cells from the deleterious effects of protein misfolding and aggregation. Neurotoxicity of amyloid-beta (Aβ) aggregates and their deposition in senile plaques are...Full Text Available
Exogenously supplied indole-3-acetic acid (IAA) stimulated ethylene production in tobacco (Nicotiana glauca) leaf discs but not in those of sugar beet (Beta vulgaris...Full Text Available
A beta microprobe was successfully applied to monitor arterial input function for quantification of regional cerebral blood flow (rCBF) in the monkey brain with {sup 15}O-water and positron emission tomography (PET). The sensitivity of the probe was approximately 0.83 to 1.67 cps/kBq/ml depending on the studies. A preliminary study was performed to find a suitable use and to evaluate the performance of the system and data analysis procedure. The results showed that dispersion correction of measured input function was unnecessary if microprobes were connected directly to the arterial catheter. Then multiple CBF measurements were done in three monkeys under anesthesia. Identical regions of interest were placed with the aid of magnetic resonance imaging (MRI) of each monkey and rCBF values were estimated. Estimated rCBFs were reproducible for several measurements. The mean CBF value for a pentobarbital anesthetized monkey was 46.0 ml/min/100 g (PaCO{sub 2}=46.3 mmHg). ...
The carboxyl-terminal region of tubulin alpha and beta subunits plays a major role in regulating its assembly into microtubules and constitutes an essential domain for the selective interaction of microtubule-associated...Full Text Available
Wood, R. A.; and Ogden, H. R.: The All-Beta Titanium Alloy (Ti-13V-llCr-3Al). DMIC Rept. 110 (ASTIA AD 214002), Battelle Mem. Inst., Apr. 17, 1959. 22. White ...
1. To explore mechanisms of urinary obstruction in benign prostatic hyperplasia (BPH), the features of contraction and relaxation in human hyperplastic and non-hyperplastic (control) prostatic tissues...Full Text Available
Humanin (HN), a 24-residue peptide, was identified as a novel neuroprotective factor and shows anti-cell death activity against a wide spectrum of Alzheimer's disease (AD)-related cytotoxicities, including...Full Text Available
There has been a good deal of interest in the sialon system of ceramics in recent years due to their combination of important engineering properties #beta# including strength, hardness, low thermal expansion and good thermal shock resistance. #beta#-sialon (Si_6_-_zAl_zO_zN_8_-_z ;0beta#-sialon via the carbothermal reduction route and reports specifically on the utilisation of "2"9Si and "2"7Al solid state Nuclear Magnetic Resonance techniques in determining the nature of intermediate phases which occur. 9 refs., 1 tab., 1 ...
The unknown #beta#-decay half-lives of 22 isotopes far off stability (5 < T_Z < 10) in the region from Ti to Ni were measured at GSI, Darmstadt. The nuclei were produced in a fragmentation reaction of 500 A.MeV "8"6Kr-projectile impinging on a thick Be target. The isotopes of interest were separated and identified with the fragment separator, FRS, by a combination of B#rho#,Z, and ToF techniques. An additional range separation was performed by a selective implantation into granular detectors. The spatial and time correlations of the implant with the consecutively detected #beta#-particles were used to determine the unknown half-lives. For nuclei far off stability, #beta#-decay chains were measured and analyzed as well, leading to an even more reliable evaluation of the lifetimes. The large discrepancies found between the measured and the theoretical values emphasize that most recent theoretical work is not an ...
The isomeric and {beta}-decay properties of neutron-rich {sup 53-57}Sc and {sup 53,54}Ca nuclei near neutron number N = 32 are reported, and the low-energy level schemes of {sup 53,54,56}Sc and {sup 53-57}Ti are presented. The low-energy level structures of the {sub 21}Sc isotopes are discussed in terms of the coupling of the valence 1f{sub 7/2} proton to states in the corresponding {sub 20}Ca cores. Implications with respect to the robustness of the N = 32 subshell closure are discussed, as well as the repercussions for a possible N = 34 subshell closure.
The threshold stress intensities for stress corrosion crack propagation in beta titanium alloy 38-6-44, Ti3Al-8V-6Cr-4Mo-4Zr, has been determined in salt water and methanolic solutions. The alloy was immune to stress corrosion cracking (SCC) in aqueous sodium chloride solutions (marine atmosphere). However, in methanolic solutions, the alloy was very susceptible to SCC. This marked susceptibility in methanolic solutions can be mitigated by the addition of an inhibitor: sodium nitrate. Crack extension in the alloy was transgranular and failure occurred by brittle quasi-cleavage in methanolic solutions.
Strain rate effects for the high strength, metastable beta-titanium alloy Ti-8Mo-8V-2Fe-3Al are assessed in terms of tensile and fracture toughness behavior. It is shown that as the strain rate increases the yield strength, ultimate tensile strength, and ductility also increase. As a result of the decrease in the amount of intergranular fracture as the strain rate is increased, the dynamic fracture toughness values K/sub Id/ are greater than those obtained under static conditions as given by K/sub Q/.
We demonstrate reversible movement of (1/2)[110](110) dislocation loops generated from nanodisturbances in a #beta#-titanium alloy. High resolution transmission electron microscope observations during an in situ tensile test found three reversible deformation mechanisms, nanodisturbances, dislocation loops and martensitic transformation, that are triggered in turn with increasing applied stress. All three mechanisms contribute to the nonlinear elasticity of the alloy. The experiments also revealed the evolution of the dislocation loops to disclination dipoles that cause severe local lattice rotations.
By the methods of microstructural and electron-microscopic analyses by the tension test and impact test studied is the effect of quenching conditions on structure and mechanical properties of the TS6 titanium-#beta# alloy. It is shown that low temperature quenching from 700 deg C, recommended earlier for analogous VT15 titanium alloy, leads to appearence of intercrystalline fracture and to sharp decrease of impact strength of the TS6 alloy. Established are optimum conditions for quenching of half-finished products and articles of the TS6 alloy depending on their subsequent working or operation.
Q/sub ..beta..-values are determined for 18 nuclei (Zr-, Nb-, Mo-, Tc-, Ru- and Rh-nuclides) with mass numbers 101 less than or equal toA less than or equal to106 and A=109 from measurements of beta decay energies which were carried out at the LOHENGRIN mass separator at the Institut Laue-Langevin in Grenoble (France). The given Q/sub ..beta..-values between 2 and 8 MeV show errors of about 1.5% (with the exception of /sup 103/Zr and /sup 105/Nb resp. and /sup 103/Tc for which larger errors result due to statistical resp. systematic reasons): /sup 101/Zr 5500+-70, /sup 101/Nb 4580+-45, /sup 102/Zr 4670+-40, /sup 102/Nb 7230+-70, /sup 103/Zr 6790+-240, /sup 103/ 5740+-70, /sup 103/Mo 3575+-80, /sup 103/Tc 2585+-70, /sup 104/Nb 8250+-130, /sup 104/Mo 2180+-40, /sup 104/Tc 5520+-100, /sup 105/Nb 6570+-150, /sup 105/Mo 4885+-80, /sup 105/Tc 3750+-60, /sup 106/Mo 3515+-45, /sup 106/Tc 6540+-70, /sup 109/Ru 4150+-80, /sup 109/Rh ...
Bragg peaks obtained in X-ray stress analysis studies are often asymmetric. The use of K/sub ..beta../ rather than K/sub ..cap alpha../ radiation simplifies the problem of peak location, as only one Bragg peak needs to be analysed. It is shown, however, that the common practice of fitting a parabola to the top 15% of the data in a Bragg peak in order to determine the peak position, when the fitted region is asymmetric, can lead to large errors in the calculated stress. Asymmetric pseudo-Lorentzian functions have been found to provide the most satisfactory fits.
LUCIFER (Low-background Underground Cryogenic Installation For Elusive Rates) is a new project for the study of neutrinoless Double Beta Decay, based on the technology of scintillating bolometers. These devices promise a very efficient rejection of the alpha background, opening the way to a virtual background-free experiment if candidates with a transition energy higher than 2615 keV are investigated. The baseline candidate for LUCIFER is 82Se. This isotope will be embedded in ZnSe crystals grown with enriched selenium and operated as scintillating bolometers in a low-radioactivity underground dilution refrigerator. In this paper, the LUCIFER concept will be introduced. The sensitivity and the very promising prospects related to this project will be discussed.
The LANL 2.5-cell, normal-conducting radio-frequency (NCRF) injector has been fabricated. We present initial results of low-power RF measurements (cavity Q, cavity field map, coupling beta, etc.) of the NCRF injector. The measured cavity Q and relative fields are found to be in good agreement with the design calculations and earlier measurements of Glidcop properties. However, the coupling beta of the ridge-loaded waveguides is found to be significantly higher than the design point. The impact of these low-power measurement results on the planned high-power RF and electron beam tests will be discussed.
The refractory nature and high ductility of body centered cubic (bcc) phase tantalum makes it a suitable material for corrosion- and wear-resistant coatings on surfaces that are subjected to high stresses and harsh chemical and erosive environments. Sputter deposition can produce thick tantalum films but is prone to forming the brittle tetragonal beta phase of this material. Efforts aimed at forming thick bcc phase tantalum coatings in both flat plate and cylindrical geometries by high-rate triode sputtering methods are discussed. In addition to substrate temperature, the bcc-to-beta phase ratio in sputtered tantalum coatings is shown to be sensitive to other substrate surface effects.
The influence of deformation on the corrosion behavior of a newly developed multifunctional beta titanium alloy Ti-23Nb-0.7Ta-2Zr-O (mol%) in Ringer's solution at 310 K was evaluated using an electron backscatter diffraction technique and electrochemical measurements. The results showed that the effect of deformation on the corrosion resistance of the beta titanium alloy is complicated. Small levels of plastic deformation are detrimental to the corrosion resistance, whereas large deformations tend to eliminate this detrimental effect.
In a program to develop a metastable beta alloy with improved fracture toughness, it was found that the tensile ductility of the alloy Ti-8 Mo-4.5 Cr-2.5 Al was strongly dependent on both processing history and annealing temperature. Evaluation of the microfracture mode of tensile samples by scanning electron microscope and metallographic techniques showed that the presence of a continuous grain boundary alpha is the most significant parameter controlling the ductility and is highly detrimental. It is concluded that, for optimum processing, the material must be worked prior to aging to avoid this grain boundary phase.
Evaluation of ageable beta alloys Ti-17V-2Fe-2Co-3Al, Ti-17V-7.5Co-3A1 and Ti-8Mo-8V-5Co-3Al continued with room and elevated temperature smooth and notched tensile tests, creep stability, oxidation and stress-corrosion tests. Ti-17V-7.5Co-3Al aged more r...
Beta-decay studies of the new neutron-rich isotopes sup(58,59)Cr, "6"3Mn, sup(66,67)Co and "6"9Ni, yielding distinctly shorter half-lives than the corresponding theoretical predictions, are presented. The influence of the short half-lives on the r-process calculations of nuclear abundances is discussed. It is concluded that a significantly higher neutron density than the one obtained from explosive helium burning in supernovae is needed to reproduce the observed abundances around A = 80. (orig.).