Technology is being developed for preparing functional materials by synthesizing new functional peptides in which non-natural amino acid needed for the functional manifestation is introduced, and by modifying the surface of a base plate such as silica glass by using such peptides. Activities were conducted in the three areas of (1) creation of functional molecules, (2) materialization technology, and (3) comprehensive investigation and research; the activities were carried out independently and parallelly in the first two areas. In (1), design technique for the structures and functions of peptides was developed, as were conformational control technique, synthesis of peptides having optical/electronic functions, peptide synthesis by an enzyme method, and R and D on introduction of non-natural amino acid into peptides; in (2), element technologies were developed ...
Nop25 is a putative RNA binding nucleolar protein associated with rRNA transcription. The present study was undertaken to determine the mechanism of Nop25 localization in the nucleolus. Deletion experiments of Nop25 amino acid sequence showed Nop25 to contain a nuclear targeting sequence in the N-terminal and a nucleolar targeting sequence in the C-terminal. By expressing derivative peptides from the C-terminal as GFP-fusion proteins in the cells, a lysine and arginine residue-enriched peptide (KRKHPRRAQDSTKKPPSATRTSKTQRRRR) allowed a GFP-fusion protein to be transported and fully retained in the nucleolus. When the peptide was fused with cMyc epitope and expressed in the cells, a cMyc epitope was then detected in the nucleolus. Nop25 did not localize in the nucleolus by deletion of the peptide from Nop25. Furthermore, deletion of a subdomain (KRKHPRRAQ) in the peptide or amino acid ...
The sequence segment 181-200 of the Torpedo nicotinic acetylcholine receptor (nAChR) #alpha#subunit forms a binding site for #alpha#-bungarotoxin (#alpha#-BTX). Synthetic peptides corresponding to the homologous sequences of human, calf, mouse, chicken, frog, and cobra muscle nAChR #alpha#1 subunits were tested for their ability to bind "1"2"5I-#alpha#-BTX, and differences in #alpha#-BTX affinity were determined by using solution (IC_5_0s) and solid-phase (K_ds) assays. Panels of overlapping peptides corresponding to the complete #alpha#1 subunit of mouse and human were also tested for #alpha#-BTX binding, but other sequence segments forming the #alpha#-BTX site were not consistently detectable. The role of a putative vicinal disulfide bound between Cys-192 and -193, relative to the Torpedo sequence, was determined by modifying the peptides with sulfhydryl reagents. Reduction and alkylation of the ...
The affinity label 8-((4-bromo-2,3-dioxobutyl)thio)adenosine 5{prime}-triphosphate (8-BDB-TA-5{prime}-TP) reacts covalently with rabbit muscle pyruvate kinase, incorporating 2 mol of reagent/mol of enzyme subunit upon complete inactivation. Protection against inactivation is provided by phosphoenolpyruvate, K{sup +}, and Mn{sup 2+} and only 1 mol of reagent/mol of subunit is incorporated. The authors have now identified the resultant modified residues. After reaction with 8-BDB-TA-5{prime}-TP at pH 7.0, modified enzyme was incubated with ({sup 3}H)NaBH{sub 4} to reduce the carbonyl groups of enzyme-bound 8-BDB-TA-5{prime}-TP and to introduce a radioactive tracer into the modified residues. Following carboxymethylation and digestion with trypsin, the radioactive peptides were separated on a phenylboronate agarose column followed by reverse-phase high-performance liquid chromatography in 0.1% trifluoroacetic acid with an acetonitrile gradient. Gas-phase sequencing ...
Transgenic plants offer advantages for biomolecule production because plants can be grown on a large scale and the recombinant macromolecules can be easily harvested and extracted. We introduced an Aspergillus phytase gene into canola (Brassica napus) (line 9412 with low erucic acid and low glucosinolates) by Agrobacterium-mediated transformation. Phytase expression in transgenic plant was enhanced with a synthetic phytase gene according to the Brassica codon usage and an endoplasmic reticulum (ER) retention signal KDEL that confers an ER accumulation of the recombinant phytase. Secretion of the phytase to the extracellular fluid was also established by the use of the tobacco PR-S signal peptide. Phytase accumulation in mature seed accounted for 2.6% of the total soluble proteins. The enzy...
A general method is described to sequester peptides containing azides from complex peptide mixtures, aimed at facilitating mass spectrometric analysis to study different aspects of proteome...Full Text Available
A pore-forming peptide is implicated in the potent cytolytic activity of pathogenic Entamoeba histolytica. Using NH2-terminal sequence information of this peptide, the corresponding cDNA was isolated....Full Text Available
A hallmark of congestive heart failure (CHF) is the activation of the cardiac endocrine system, in particular atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP). The natriuretic peptides are a group of structurally similar but genetically distinct peptides that have diverse actions in cardiovascular, renal, and endocrine homeostasis. ANP and BNP are of myocardial cell origin and C-type natriuretic peptide (CNP) is of endothelial origin. ANP and BNP bind to the natriuretic peptide-A receptor (NPR-A), which, via 3',5'-cyclic guanosine monophosphate (cGMP), mediates natriuresis, vasodilatation, renin inhibition, antimitogenesis, and lusitropic properties. CNP lacks natriuretic actions but possesses vasodilating and growth inhibiting actions via the guanylyl cyclase-linked natriuretic peptide-B receptor. All three ...
BackgroundThe binding of peptide fragments of antigens to class II MHC is a crucial step in initiating a helper T cell immune response. The identification of such peptide epitopes...Full Text Available
AIM: To investigate atrial natriuretic peptide (ANP) secretion from gastric mucosa and the relationship between the ANP/natriuretic peptide receptor type A (NPR-A) pathway and diabetic gastroparesis.METHODS:...Full Text Available
The sequences of the peptide binding domains of 33 70 kd heat shock proteins (hsp70) have been aligned and a consensus secondary structure has been deduced. Individual members showed no significant...Full Text Available
BackgroundAmino-terminal signal peptides (SPs) are short regions that guide the targeting of secretory proteins to the correct subcellular compartments in the cell. They are cleaved...Full Text Available
The family of natriuretic peptides consists of the atria natriuretic peptide (ANP), the cerebral natriuretic peptide (BNP), the type C natriuretic peptide (CNP) and the peptide isolated from the dendroaspis snakes' poison (DNP), whose presence in humans has not been confirmed. The physiological function of ANP is in the control of arterial blood pressure by regulation of systemic vascular resistance of blood vessels. BNP is produced as one of the factors in the acute response to inflammatory tissue damage, mainly in coronary vessels. Increased serum concentrations of natriuretic peptides have been found in stress situations, such as trauma or major surgery, systemic hypotension, and in intrinsic myocardial dysfunction. High concentrations of natriuretic peptides were observed in severe sepsis, septic shock and in multiple organ failure, ...
Four major natriuretic peptides have been isolated: atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), C-type natriuretic peptide (CNP), and Dendroaspis-type natriuretic peptide (DNP). Natriuretic peptides play an important role in the regulation of cardiovascular homeostasis maintaining blood pressure and extracellular fluid volume. The classical endocrine effects of natriuretic peptides to modulate fluid and electrolyte balance and vascular smooth muscle tone are complemented by autocrine and paracrine actions that include regulation of coronary blood flow and, therefore, myocardial perfusion; modulation of proliferative responses during myocardial and vascular remodeling; and cytoprotective anti-ischemic effects. The actions of natriuretic peptides are mediated by the specific binding of these ...
C-type natriuretic peptide (CNP) is a member of the small family of natriuretic peptides that also includes atrial natriuretic peptide (ANP) and brain, or B-type natriuretic peptide (BNP). Unlike them, it performs its major functions in an autocrine or paracrine manner. Those functions, mediated through binding to the membrane guanylyl cyclase natriuretic peptide receptor B (NPR-B), or by signaling through the non-enzyme natriuretic peptide receptor C (NPR-C), include the regulation of endochondral ossification, reproduction, nervous system development, and the maintenance of cardiovascular health. To date, the regulation of CNP gene expression has not received the attention that has been paid to regulation of the ANP and BNP genes. CNP expression in vitro is regulated by TGF-b and recepto...
Glucagon-like peptide-2 (GLP-2) is a nutrient-regulated intestinotrophic hormone derived from proglucagon in the distal intestine. Enteral nutrients (EN) potentiate the action of GLP-2 to reverse parenteral...Full Text Available
BackgroundCalcitonin gene related peptide (CGRP) is a neuropeptide that is abundant in the sensory neurons which innervate bone. The effects of CGRP on isolated bone cells have been...Full Text Available
OBJECTIVEThis randomized, four-arm, placebo-controlled, dose-ranging phase 2 trial was conducted to determine whether repeated subcutaneous injections of the altered peptide ligand,...Full Text Available
A unique antibacterial peptide derivative found in immune honeybee lymph, apidaecin 1b (AP1), was randomly mutagenized and characterized by a newly established system to analyze in vivo its structure-function...Full Text Available
High-density lipoproteins (HDL) were examined as potential carriers of small peptides in plasma. HDL purified by density gradient centrifugation was delipidated and fractionated by size-exclusion...Full Text Available
Atrial natriuretic peptide (ANP) causes relaxation in the opossum lower esophageal sphincter. The effects of dendroaspis natriuretic peptide (DNP) and other natriuretic peptides in the lower esophageal sphincter were not known. We measured the relaxation of transverse strips from the guinea pig lower esophageal sphincter caused by DNP, ANP, brain natriuretic peptide (BNP), C-type natriuretic peptide (CNP), and a natriuretic peptide receptor-C agonist des[Gln^1^8, Ser^1^9, Gly^2^0, Leu^2^1, Gly^2^2]ANP(4-23) amide (cANF(4-23)) in vitro. In resting strips of the guinea pig lower esophageal sphincter DNP and BNP caused marked relaxations. Furthermore, in both sarafotoxin S6c and carbachol-contracted lower esophageal sphincter strips, DNP caused marked and BNP caused moderate, concentration-de...
BackgroundAtrial fibrillation (AF) is the most common cardiac arrhythmia with a population prevalence of about 1%. Natriuretic peptide level is elevated in patients with AF with...Full Text Available
BackgroundMammalian antimicrobial peptides (AMPs) are effectors of the innate immune response. A multitude of signals coming from pathways of mammalian pathogen/pattern recognition...Full Text Available
CART peptides are endogenous neurotransmitters that are involved in a variety of physiologic functions. Injection of CART 55-102 into the nucleus accumbens produces no effect, but when co-administered...Full Text Available
Recombinant biotin-binding phages were affinity-selected from a random peptide library expressed on the surface of filamentous phage. Phage binding to biotinylated proteins was half-maximally inhibited...Full Text Available
Background: The causes of elevated B-Type natriuretic peptide (BNP) levels are multifactorial. Renal dysfunction has been shown to affect BNP levels in some studies and...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
In the cellular immune response, recognition by CTL-TCRs of viral antigens presented as peptides by HLA class I molecules, triggers destruction of the virally infected cell (Townsend, A.R.M., J. Rothbard,...Full Text Available
The identification of MHC class II restricted peptide epitopes is an important goal in immunological research. A number of computational tools have been developed for this purpose, but there is a lack...Full Text Available
The gastrin releasing peptide (GRP) receptor is becoming an increasingly attractive target for development of new radiolabeled peptides with diagnostic and therapeutic potential. The attractiveness of the GRP receptor as a target is based upon the functional expression of GRP receptors in several tumors of neuroendocrine origin including prostate, breast, and small cell lung cancer. This concise review outlines some of the efforts currently underway to develop new GRP receptor specific radiopharmaceuticals by employing a variety of radiometal chelation systems.
A new proprietary de novo peptide design technique generated ten 15-residue peptides targeting and containing the leading nontransmembrane hydrophobic autocorrelation wavelengths, “modes”,...Full Text Available
Alzheimer's disease (AD) is a neurodegenerative disorder for which the research of new treatments is highly challenging. Since the fibrillogenesis of amyloid-b peptide 1-42 (Ab1-42) peptide is considered as a major cause of neuronal degeneration, specific interest has been focused on aromatic molecules for targeting this peptide. In this paper, the synthesis of selegiline-functionalized and fluorescent poly(alkyl cyanoacrylate) nanoparticles (NPs) and their evaluation for the targeting of the Ab1-42 peptide are reported. The synthetic strategy relied on the design of amphiphilic copolymers by tandem Knoevenagel-Michael addition of cyanoacetate derivatives, followed by their self-assembly in aqueous solutions to give the corresponding NPs. Different cyanoacetates were used: (i) hexadecyl cy...
Abstract Lyme neuroborreliosis (LNB) is a serious but treatable disease. The diagnosis of LNB poses a challenge to clinicians, and improved tests are needed. The C6-peptide ELISA is frequently used on serum but not on cerebrospinal fluid (CSF). Data on the sensitivity of the C6-peptide ELISA in CSF in patients suffering from LNB have been conflicting. Serum-CSF pairs from 59 LNB patients, 36 Lyme non-neuroborreliosis cases, 69 infectious meningitis/encephalitis controls and 74 neurological controls were tested in a C6-peptide ELISA. With the optimal cut-off of 1.1, the sensitivity of the C6-peptide ELISA for LNB patients in CSF was 95%, and the specificity was 83% in the Lyme non-neuroborreliosis patients, 96% in the infectious controls, and 97% in the neurological controls. These results ...
Cholera toxin catalyzes transfer of radiolabel from ["3"2P]NAD"+ to several peptides in particulate preparations of human foreskin fibroblasts. Resolution of these peptides by two-dimensional gel electrophoresis allowed identification of two peptides of M/sub r/ = 42,000 and 52,000 as peptide subunits of a regulatory component of adenylate cyclase. The radiolabeling of another group of peptides (M/sub r/ = 50,000 to 65,000) suggested that cholera toxin could catalyze ADP-ribosylation of cytoskeletal proteins. This suggestion was confirmed by showing that incubation with cholera toxin and ["3"2P]NAD"+ caused radiolabeling of purified microtubule and intermediate filament proteins.
Amyloid aggregation starts with the initial misfolding of peptide/protein precursors, with subsequent structural rearrangement into oligomers and protofibrils; the latter eventually organize into fibrils with shared basic structural features, found deposited in amyloid diseases. Mounting evidence indicates early oligomers as the most toxic amyloid species; accordingly, the search of inhibitors of their growth is considered a promising target to prevent amyloid toxicity. We recently showed that oleuropein aglycon, a polyphenol abundant in the extra virgin olive oil, interferes with the aggregation of amylin (involved in type-2 diabetes), eliminating its cytotoxicity. Here we report that oleuropein aglycon also hinders amyloid aggregation of A?(1-42) and its cytotoxicity, suggesting a general effect of such polyphenol. In particular, by using a wide panel of different spectroscopic, immunologic, cell viability and imaging techniques we provide a more detailed ...
The natriuretic peptides are considered to be cardioprotective; however, their receptors have not been identified in human myocardium using radiolabeled analogs. Dendroaspis natriuretic peptide (DNP) has been recently identified as a new member of this peptide family and is thought to be less susceptible to enzymatic degradation. Therefore, we have developed the novel radiolabeled analog [125I]-DNP and used this to localize high-affinity (K(D)=0.2 nmol/L), saturable, specific binding sites in adult human heart (n=6) and coronary artery (n=8). In competition binding experiments, atrial natriuretic peptide and brain type natriuretic peptide had greater affinity for [125I]-DNP binding sites than C-type natriuretic peptide and the natriuretic peptide receptor (NPR)-C ligand, cANF. This rank order of potency suggested binding of [125I]-DNP was ...
Synthetic atrial natriuretic peptide (carperitide) and B-type natriuretic peptide (BNP; nesiritide) are used to treat congestive heart failure. However, despite beneficial cardiac unloading properties, reductions in renal perfusion pressures limit their clinical effectiveness. Recently, CD-NP, a chimeric peptide composed of C-type natriuretic peptide (CNP) fused to the C-terminal tail of Dendroaspis natriuretic peptide (DNP), was shown to be more glomerular filtration rate-enhancing than BNP in dogs. However, the molecular basis for the increased responsiveness was not determined. Here, we show that the DNP tail has a striking effect on CNP, converting it from a non-agonist to a partial agonist of natriuretic peptide receptor (NPR)-A while maintaining the ability to activate NPR-B. This effect is specific for human receptors because CD-NP was only a slightly ...
The term "homology" or "homologous" means an amino acid similarity measured by the program, BLAST (Altschul et al (1997), "Gapped BLAST and PSI-BLAST: a new generation of protein database search programs", Nucleic Acids Res. 25:33 89 3402), and expressed as --(% identity n/n). In measuring homology between a peptide and a protein of greater size, homology is measured only in the corresponding region; that is, the protein is regarded as only having the same general length as the peptide, allowing for gaps and insertions.
SummaryMammalian iron homeostasis is regulated by the interaction of the liver-produced peptide hepcidin and its receptor, the iron transporter ferroportin. Hepcidin binds to...Full Text Available
In an effort to develop octahedral metal complexes as chemotherapeutic and diagnostic agents targeted to DNA, it is critical to optimize the properties of their cellular uptake. Appending d-octaarginine...Full Text Available
Endogenous opioid peptides are substances involved in cell communication. They are present in various organs and tissues of the male and female reproductive tract, suggesting that they may regulate...Full Text Available
BackgroundGenetic predisposition to scrapie in sheep is associated with several variations in the peptide sequence of the prion protein gene (PRNP). DNA-based tests...Full Text Available
This study aims to investigate the difference in the interaction of antimicrobial peptides with two classes of zwitterionic peptides, phosphatidylethanolamines (PE) and phosphatidylcholines (PC). Further experiments were performed on model membranes prepared from specific bacterial lipids, lipopolysaccharides (LPS) isolated from Salmonella minnesota. The structure of the lipid-peptide aqueous dispersions was studied by small-and wide-angle X-ray diffraction during heating and cooling from 5 to 85 C. The lipids and peptides were mixed at lipid-to-peptide ratios 10-10000 (POPE and POPC) or 2-50 (LPS). All experiments were performed at synchrotron soft condensed matter beamline A2 in Hasylab at Desy in Hamburg, Germany. The phases were identified and the lattice parameters were calculated. Alamethicin and melittin interact in similar ways with the lipids. Pure POPC forms only lamellar ...
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 #beta#-turn contribution and D-Asp-substituted peptide ([D-Asp"2"3]A#beta#_2_0_-_2_9) ...
Insulin-degrading enzyme (IDE) degrades insulin and other peptides, including the Aβ peptide of Alzheimer’s disease. However, the mechanism by which IDE acts on its substrates...Full Text Available
Staphylococcus aureus survives inside eukaryotic cells. Our objective was to assess the activity of NZ2114, a novel peptidic antibiotic, against intracellular S. aureus in comparison with established antistaphylococcal agents acting on the bacterial envelope with a distinct mechanism.
A collection of neurons in the upper lumbar spinal cord of male rats projects to the lower lumbar spinal cord, releasing gastrin-releasing peptide (GRP) onto somatic and autonomic centers known to regulate...Full Text Available
CD-NP is a novel chimeric natriuretic peptide (NP) consisting of the 22-amino-acid (AA) human C-type natriuretic peptide (CNP), a venodilating peptide with limited renal actions and minimal effects on blood pressure, and the 15-AA C-terminus of Dendroaspis NP (DNP). The rationale for the design of CD-NP was to enhance the renal actions of CNP, the ligand for natriuretic peptide receptor-B, but without inducing excessive hypotension. Here we report the first-in-human studies for CD-NP, which represent the first successful clinical testing of a chimeric NP demonstrating in normal human volunteers that CD-NP possesses cyclic guanosine monophosphate-activating, natriuretic, and aldosterone-suppressing properties without inducing excessive hypotension, laying the foundation for additional studies on this first-in-class new cardiovascular therapeutic in human heart failure, which are now underway worldwide. ...
Cell-penetrating peptides (CPPs) are useful tools for the delivery of hydrophilic bioactive molecules, such as peptides, proteins, and oligonucleotides, across the cell membrane. To realize the delivery of therapeutic macromolecules by CPPs, the CPPs are required to show resistance to protease and no cytotoxicity. In order to produce potent non-toxic and protease-resistant CPPs with high cellular uptake, we designed an amphipathic helix peptide using ?-aminoisobutyric acid (Aib, U) and named it MAP(Aib). In the MAP(Aib) molecule, five Aib residues are aligned on the hydrophobic face of the helix and five lysine (K) residues are aligned on the hydrophilic face. MAP(Aib) showed potent resistance to trypsin and pronase compared with MAP, an amphipathic helix peptide formed by usual amino acids. Fluorescein-labeled MAP(Aib) efficiently traversed the A549 cell membrane, diffusing into the cytoplasm and ...
In APCs, presentation by MHC II molecules of the chemically dominant peptide from the protein hen egg white lysozyme (HEL) generates different conformational isomers of the peptide-MHC II complexes (pMHC). Type B pMHCs are formed in early endosomes from exogenous peptides in the absence of H2-DM, whereas in contrast, type A pMHC complexes are formed from HEL protein in late vesicles after editing by H2-DM. Thus, H2-DM edits off the more unstable pMHC complexes, which are not presented from HEL. In this study, we show that type B pMHC complexes were presented from HEL protein only after stimulation of dendritic cells (DC) with TLR ligands or type I IFN. Type I IFN contributed to most TLR ligand-induced type B pMHC generation, as presentation decreased in DC lacking the receptor for type I IFNs (IFNAR1(-/-)). In contrast, presentation of type A pMHC from HEL and from peptide was minimally affected by TLR ...
The amino acid residues 114-118 in actin were found to be implicated strongly in the binding of nucleotide, and as would be expected for such an important binding site, they are located in a completely conserved region of the actin sequence. A 19-residue peptide with the actin sequence 106-124 was synthesized in order to span the putative triphosphate binding site. Proton NMR spectra of the actin peptide 114-118 in the presence and absence of ATP indicated that Arg-116 and Lys-118 are particularly involved in binding ATP. A strong binding of ATP to the peptide 106-124 also was measured. Tripolyphosphate bound to the peptide 106-124 somewhat more weakly than ATP. Binding involved residues 115-118 and 121-124, indicating the presence of a reverse turn between these segments. Proton resonances were assigned by using two-dimensional double quantum correlated spectroscopy, one-dimensional spin decoupling ...
In a given species, injected opioid peptides usually cause changes in temperature similar to those caused by nonpeptide opioids. The main effect in those species most studied, the cat, rat, and mouse, is an increase in the level about which body temperature is regulated; there is a coordinated change in the activity of thermoregulatory effectors such that hyperthermia is produced in both hot and cold environments. Larger doses may depress thermoregulation, thereby causing body temperature to decrease in the cold. Elicitation of different patterns of response over a range of environmental temperatures and studies with naloxone and naltrexone indicate that stimulation of a number of different receptors by both peptide and nonpeptide opioids can evoke thermoregulatory responses. ..beta..-Endorphin is readily antagonized by naloxone whereas methionine-enkephalin can act on naloxone-insensitive receptors. Moreover, synthetic ...
Introduction: Tumor-derived heat shock protein (HSP)-peptide complexes (HSPPCs) induced immunity against malignancies in preclinical trials, working across tumor types and bypassing the need to identify single immunogenic peptides. These results paved the way for the use of human gp96 obtained from autologous tumor samples as an anti-cancer vaccine. Areas covered: Autologous tumor-derived HSP gp96 peptide complex (HSPPC-96) vaccine is emerging as a tumor- and patient-specific cancer vaccine, with confirmed activity in several malignancies. It has been tested in Phase III clinical trials in advanced melanoma and kidney cancer with evidence for efficacy in patients with earlier stage disease. HSPPC-96-based vaccine demonstrated an excellent safety profile, thus emerging as a novel therapeuti...
Antibodies to hemoglobin have been studied with a radioimmunoassay which employs ["1"4C]carbamylated (= carbamoylated) hemoglobin S. An antiserum raised against hemoglobin S, which initially discriminated poorly between hemoglobins S and A, was fractionated by absorption to a column of Sepharose to which a synthetic peptide corresponding to the first 13 amino-acid residues of the #beta# chain of sickle hemoglobin had been covalently bound. A subpopulation of the antiserum was eluted from this column with 4 M guanidine . HCl. These antibodies showed binding to hemoglobin S but not to hemoglobin A and this interaction could be inhibited by the synthetic peptide. These antibodies, of demonstrated fine structural specificity, may be useful in the detection of sickle hemoglobin and in the study of its structure in solution.
This study was conducted to investigate the antibacterial effect of BSAP-254 on Bacillus cereus with the induced stress proteins. The BSAP-254 is an antimicrobial peptide isolated from soybean-fermenting bacteria, Bacillus subtilis SC-8. It had a narrow spectrum of activity against B. cereus group. The growth inhibitory effect of BSAP-254 (50??g/mL) reduced the population of B. cereus from >108 to 104 colony-forming units per milliliter within 30?min. In B. cereus exposed to BSAP-254, 14 intracellular proteins were differentially expressed as determined by 2-DE coupled with MS. Of the differentially expressed proteins identified, the stress protein GroEL, which is heat shock protein, was induced in B. cereus exposed to antibacterial peptide.
The atmospheric processing by ozone of peptide-containing mixed particles was investigated as proxies for biogenic and sea spray primary organic aerosol. Reactions were performed in a flow reactor and particle composition was monitored by photoelectron resonance capture ionization aerosol mass spectrometry. Mixed particles containing dipeptides in a saturated organic matrix of stearic and palmitic acids showed no reaction under ozonolysis at exposure levels of 2.5???10?4?atm s O3. However reactions of mixed particles of a dipeptide (Leu-Leu) in an unsaturated matrix (oleic acid) under the same conditions resulted in a rapid loss of the peptide ion signal, as well as the carrier matrix, and appearance of a number of ion signals corresponding to secondary products. High molecular weight imid...
Analyses of food-borne pathogens are of great importance in order to minimize the health risk for customers. Thus, very sensitive and rapid detection methods are required. Current conventional culture techniques are very time consuming. Modern immunoassays and biochemical analysis also require pre-enrichment steps resulting in a turnaround time of at least 24 h. Biomagnetic separation (BMS) is a promising more rapid method. In this study we describe the isolation of high affine and specific peptides from a phage-peptide library, which combined with BMS allows the detection of Salmonella spp. with a similar sensitivity as that of immunomagnetic separation using antibodies.
Effector proteins expressed in the esophageal gland cells of cyst nematodes are delivered into plant cells through a hollow, protrusible stylet. Although evidence indicates that effector proteins function...Full Text Available
The acyl coenzyme A (CoA) binding protein AcbA is secreted unconventionally and processed into spore differentiation factor 2 (SDF-2), a peptide that coordinates sporulation in Dictyostelium...Full Text Available
AbstractThere is an urgent need for innovative therapies against ovarian cancer, one of the leading causes of death from gynecological cancers in the United States. Immunotherapy employing...Full Text Available
1. Seven unique carboxymethylcysteine-containing peptides have been isolated from tryptic digests of rabbit muscle aldolase carboxymethylated with iodo[2-14C]acetic acid in 8m-urea....Full Text Available
OBJECTIVETo determine if ProL1, a member of the opiorphin family of genes, can modulate erectile physiology, as it encodes a peptide which acts as...Full Text Available
We have performed multicanonical Monte Carlo simulations of C-peptide of ribonuclease A. It is known by CD and NMR experiments that this peptide has high alpha-helix content in aqueous solution and that the side-chain charges of residues Glu-2$^-$ and His-12$^+$ play an important role in the stability of the alpha-helix. In order to confirm these experimental implications, we have used two analogues of the peptide with charged and neutral side chains of Glu-2 and His-12. Two dielectric functions, distance-dependent and constant, are considered to study the effects of solvent contributions. All the simulations were started from random initial conformations. Various thermodynamic quantities such as average helicity as a function of residue number and average distance between two side chains as a function of temperature are calculated. The results are found to be in accord with the implications of CD and NMR experiments. The ...
To capitalize on the response of tumor cells to ionizing radiation, we developed a controlled-release nanoparticle drug delivery system using a targeting peptide that recognizes a radiation-induced...Full Text Available
Peptide toxins with high affinity, divergent pharmacological functions, and isoform-specific selectivity are powerful tools for investigating the structure-function relationships of voltage-gated...Full Text Available
In this work, we explore the potential of the metalloendopeptidase Lys-N for MALDI-MS/MS proteomics applications. Initially we digested a HEK293 cellular lysate with Lys-N and, for comparison, in parallel...Full Text Available
Constitutive activation of the transcription factor Stat5 in hematopoietic stem/progenitor cells leads to various hematopoietic malignancies including myeloproliferative neoplasm (MPN). Our recent study...Full Text Available
The neonatal Fc receptor FcRn provides IgG molecules with their characteristically long half-lives in vivo by protecting them from intracellular catabolism and then returning them to...Full Text Available
BackgroundBaculovirus, which has a width of 40 nm and a length of 250-300 nm, can display functional peptides, receptors and antigens on its surface by their fusion with a baculovirus...Full Text Available
The parathyroid hormone receptor (PTHR) is a class B G protein-coupled receptor that plays critical roles in bone and mineral ion metabolism. Ligand binding to the PTHR involves interactions to both...Full Text Available
Secreted human bronchial mucins, directly collected from macroscopically healthy bronchial mucosa, were prepared in the presence of six proteinase inhibitors, and analysed by electron microscopy. These...Full Text Available
Severe acute respiratory syndrome (SARS) is an infectious disease caused by a novel coronavirus that cost nearly 800 lives. While there have been no recent outbreaks of the disease, the threat...Full Text Available
Human skin is a local source of corticotropin-releasing hormone (CRH) and expresses CRH and CRH receptors (CRH-R) at mRNA and protein levels. Epidermal melanocytes respond to CRH by induction...Full Text Available
We have developed a method for dissecting single neurons from the nematode Ascaris suum, in order to determine their peptide content by mass spectrometry (MS). In this paper,...Full Text Available
Gastrin-releasing peptide receptor (GRPR), a member of the G protein-coupled receptor superfamily, has been utilized for receptor-mediated targeting of imaging and therapeutic agents; here we extend...Full Text Available
Type 2 diabetes mellitus (T2DM) results from insulin resistance and β-cell dysfunction, in the setting of hyperglucagonemia. Glucagon is a 29 amino acid peptide hormone, which is secreted from...Full Text Available
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.
A monensin-sensitive ruminal peptostreptococcus was able to grow rapidly (growth rate of 0.5/h) on an enzymatic hydrolysate of casein, but less than 23% of the amino acid nitrogen was ever utilized....Full Text Available
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
BackgroundThe successful interaction of bacterial pathogens with host tissues requires the sensing of specific chemical and physical cues. The human gut contains a huge number of...Full Text Available
OBJECTIVEPreimplantation factor (PIF) is a novel, 15 amino acid peptide, secreted by viable embryos. This study aims to elucidate PIF’s effects in human endometrial...Full Text Available
A pentapeptide open reading frame equipped with a canonical ribosome-binding site is present in the Escherichia coli 23S rRNA. Overexpression of 23S rRNA fragments containing the mini-gene renders cells...Full Text Available
During complementary chromatic adaptation (CCA), cyanobacterial light harvesting structures called phycobilisomes are restructured in response to ambient light quality shifts. Transcription of genes...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
Nine secondary metaboites of cyclic peptide were isolated from three mangrove endophytic fungi Paecilomyces sp. (treel-7), 4557,ZZF65. They were viscumamide(1),cyclo(Pro-Iso)(2),cyclo(Phe-Gly)(3),cyclo(Phe-Ana)(4),cyclo(Gly-Pro) (5),cyclo(Gly-Leu)(6), cyclo(Trp-Ana)(7),neoechinulin A(8),cyclo(Pro-Thr)(9). The compounds 1,7,8,9 were firstly isolated from marine fungus. PMID:18422185
BackgroundDespite an ever-improving understanding of the molecular biology of cancer, the treatment of most cancers has not changed dramatically in the past three decades and drugs that do not discriminate between tumor cells and normal tissues remain the mainstays of anticancer therapy. Since Hsp90 is typically involved in cell proliferation and survival, this is thought to play a key role in cancer, and Hsp90 has attracted considerable interest in recent years as a potential therapeutic target.MethodsWe focused on the interaction of Hsp90 with its cofactor protein p60/Hop, and engineered a cell-permeable peptidomimetic, termed "hybrid Antp-TPR peptide", modeled on the binding interface between the molecular chaperone Hsp90 and the TPR2A domain of Hop.ResultsIt was demonstrated that this designed hybrid Antp-TPR peptide inhibited the interaction of Hsp90 with the TPR2A domain, inducing cell death of breast, pancreatic, renal, lung, prostate, ...
Exposure of albumin to Cu(II) (10-100 microM) and ascorbate (0.1-2 mM) results in extensive molecular modifications, indicated by decreased fluorescence and chain breaks. The rate of utilization of...Full Text Available
The radiation method has been employed for the modification of the surface of vascular prostheses by means of acrylamide. As a result of the treatment, the tightness of the prosthesis walls was improved as well as an increase of surface hydrophilicity. Upon autoclaving, stable binding of polyacrylamide to prostheses is achieved. (author).
Protein post-translational modifications are an important biological regulatory mechanism, and the rate of their discovery using high throughput techniques is rapidly increasingly. To make use of this...Full Text Available
The methods of surface modification of Ti-Zr alloy by laser treatment are considered. Characteristics of laser modification without- and with surface melting and with melting in different gaseous environments and with nickel microalloying are presented. Maximum depth, hardness and corrosion resistance are observed under nickel laser alloying.
Advanced techniques for focused-ion-beam (FIB) device modification have been developed for complex, multistep modifications to circuitry on planar chip technology. Applying gas-assisted etching (GAE) techniques for high-aspect-ratio milling and the selective milling of both conductive and insulating films enhances process latitude. Localized ion-beam-induced deposition of an insulating film provides reconstructive capability in previously modified areas. The application of both techniques for complex device modification on VSLI devices fabricated with CMOS process technology is reviewed. (UK).
... small water or ice particles by impaction ... flight recording; principally the hydrometeor charge unit ... capability of directing aircraft movements by radio ...
The N1-methyl-Adenosine (m1A58) modification at the conserved nucleotide 58 in the TΨC loop is present in most eukaryotic tRNAs. In yeast, m1A58 modification...Full Text Available
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 ...
Designer natriuretic peptides (NPs) represent an active area of drug development. In canine and human studies, the designer natriuretic peptide CD-NP demonstrated more desirable therapeutic potential than recombinant B-type NP (BNP), which is known as nesiritide and is approved for treatment of acute decompensated heart failure. However, why CD-NP is more effective than BNP is not known. We previously reported that CD-NP is a poorer activator of human guanylyl cyclase-A (GC-A) and a better activator of human guanylyl cyclase-B than BNP. Here, guanylyl cyclase bioassays were used to compare the susceptibility of CD-NP verses ANP, BNP, CNP and DNP to inactivation by human kidney membranes. The half time (t(1/2)) for CD-NP inactivation was increased by factors of 13, 3 and 4 compared to ANP, BNP and CNP, respectively, when measured in the same assay. Surprisingly, DNP failed to undergo complete inactivation and was the most degradation resistant ...
Inorganic nanoparticles are indispensable for science and technology as materials, pigments and cosmetics products. Improving the dispersion stability of nanoparticles in various liquids is essential for those applications. In this review, we discuss why it is difficult to control the stability of nanoparticles in liquids. We also overview the role of surface interaction between nanoparticles in their dispersion and characterization, e.g. by colloid probe atomic force microscopy (CP-AFM). Two types of surface modification concepts, post-synthesis and in situ modification, were investigated in many previous studies. Here, we focus on post-synthesis modification using adsorption of various kinds of polymer dispersants and surfactants on the particle surface, as well as surface chemical reactions of silane coupling agents. We discuss CP-AFM as a technique to analyze the surface interaction between nanoparticles and the effect ...
Versions of parameterized pseudo-Newtonian gravity theories specially designed for cosmology have been introduced in recent cosmology literature. The modifications demand a zero-pressure fluid in the context of versions of modified Poisson-like equation with two different gravitational potentials. We consider such modifications in the context of relativistic gravity theories where the action is a general algebraic function of the scalar curvature, the scalar field, and the kinetic term of the field. In general it is not possible to isolate the zero-pressure fluid component simultaneously demanding a modification in the Poisson-like equation. Only in the small-scale limit we can realize some special forms of the attempted modifications. We address some loopholes in the possibility of showing non-Einstein gravity nature based on pseudo-Newtonian modifications in the cosmological ...
Laser surface modification can lead to formation of a novel microstructure on the surface of a material resulting in improved surface properties. During the past one and half decades, a number of investigations have been reported on laser surface modification techniques for improving the corrosion resistance of various materials. This paper reviews various work reported on utilising laser modification techniques for enhancing the aqueous corrosion resistance of materials. The laser surface modification work carried out on materials like stainless steels, C-steels, low alloy steels and non-ferrous materials such as Zr, Zn, Al, Ni, Mg and their alloys has been covered in the review. General features observed in improving the corrosion resistance after laser processing have been discussed and scope for future investigations in this field has been highlighted. (author). 97 refs., 15 figs., 5 tabs.
The presence of endothelin (ET)-like immunoreactivity and the cardiovascular effects of mammalian ET-1 in fish have been reported. To identify ET-related peptides in fish, we screened the cDNA library of the salmon (Oncorhynchus keta) stomach by means of rapid amplification of cDNA ends, and we cloned cDNAs encoding an ET-related peptide. The salmon ET-related sequence of 21 amino acids is identical to the trout ET-1 peptide recently purified from kidney specimens of Oncorhynchus mykiss. The deduced amino acid sequence of salmon pre-proET-1 (PPET-1) comprises 244 amino acids, including a putative signal sequence and mature ET-1, as well as big ET-1 and ET-1-like sequences. This precursor, the first reported PPET-1 sequence for Salmoniformes, Teleostei, has low homology with the sequences of human, mouse, frog (Xenopus laevis), and zebrafish (Danio rerio) PPET-1 (26%, 29%, 24%, and 39%, respectively). PMID:16740985
Zinc-fingers, which widely exist in eukaryotic cell and play crucial roles in life processes, depend on the binding of zinc ion for their proper folding. To computationally study the zinc coupled folding of the zinc-fingers, charge transfer and metal induced protonation/deprotonation effects have to be considered. Here, by attempting to implicitly account for such effects in classical molecular dynamics and performing intensive simulations with explicit solvent for the peptides with and without zinc binding, we investigate the folding of the Cys2His2 type zinc-finger motif and the coupling between the peptide folding and zinc binding. We find that zinc ion not only stabilizes the native structure, but also participates in the whole folding process. It binds to the peptide at early stage of folding, and directs or modulates the folding and stabilizations of the component beta-hairpin and alpha-helix. Such a crucial role of ...
The recent development of matrix-assisted UV laser desorption (LD) mass spectrometry has made possible the ionization and detection of extremely large molecules (with molecular weights exceeding 100,000 Daltons). This technique has generated enormous interest in the biological community for the direct examination of large peptides and oligonucleotides. Although this matrix-assisted ionization method has been developed and used almost exclusively with time-of-flight (TOF) mass spectrometers, research is currently in progress to demonstrate this technique with trapped ion mass spectrometers, such as Fourier transform ion cyclotron resonance mass spectrometry (FTMS). The potential capabilities of FTMS for wide mass range, high resolution measurement, and ion trapping experiments suggest that this instrumental technique should be useful for the detailed structural characterization of large ions generated by the matrix-assisted technique. We have recently demonstrated ...
The photoelectron resonance capture ionization (PERCI) of cysteine (Cys) and small gas-phase neutral peptides that contain the Cys residue (Cys-Gly, g-Glu-Cys, and glutathione (g-Glu-Cys-Gly)) is reported. At an ionization energy less than 1eV two types of dissociative electron attachment ionization were observed for Cys: hydrogen atom loss, resulting in formation of the ion [Cys-H]-, and dissociation of the CH2-SH bond, resulting in formation of the ion [SH]-. The presence of these ions suggests that both the p*(-CO2H) and *(C-S) orbitals can act as low energy electrophores on Cys. This ionization trend was observed for the dipeptides Cys-Gly and g-Glu-Cys as well as glutathione, with evidence that dissociation of the CH2-SH bond in these peptides can also result in ions of the form [M-SH...
The antimicrobial peptide scygonadin (Scy) was first isolated from the gonad of Scylla serrata and its gene is predominantly expressed in the ejaculatory duct of adult males. Thus, its function was predicted to be associated with reproductive immunity, but this is still unclear and needs further investigation. In our study, the expression pattern of Scy at different developmental stages of both male and female S. paramamosain was investigated, so that the potential function of this peptide could be examined. Using real-time quantitative PCR, Scy mRNA transcripts were demonstrated obviously in the vulnerable embryos and larvae-zoea I but very weakly detected in the larvae-zoea III, megalops and juveniles. The gene expression pattern showed a decreasing trend during the early developmental s...
Two peptide ligands conjugated adenine, [9-N-(tritylmercapto acetyl diglycyl aminoethyl) adenine, Tr-MAG_2-Ade] and [9-N-(tritylmercapto acetyl triglycyl aminoethyl) adenine, Tr-MAG3-Ade], are synthesized and labeled with "9"9"mTc by directly labeling method. The stability of "9"9"mTc-MAG_2- adenine and "9"9"mTc-MAG_3-adenine in vitro is measured. The uptake radios of tumor to muscle at 3h post-injection are 5.70 and 4.92, respectively. The biodistribution and scintigraphic imaging studies show that the two complexes have high localization in tumor and high contrasted tumor images can be obtained, which suggest their potential utility as tumor imaging agents. But the high radioactivity of abdomen could prevent the tumor imaging in this area. (author)
Background/Objectives: Cardiotoxic drug poisoning can lead to severe cardiac shock (CS) and death. B-type natriuretic peptide (BNP) is a well-established diagnostic and prognostic marker in heart failure but has never been assessed in patients with cardiotoxic drug poisoning. The aim of the study was to determine whether BNP could be useful for early stratification of patients admitted to intensive care unit. Methods: 30 consecutive patients experiencing shock and cardiotoxic drug exposure were enrolled in a prospective monocentric study and underwent at least two BNP measurements within the first 24 h after admission. Results: While BNP values on admission were poorly informative, subsequent BNP measurements (11 +- 6 h after admission) were significantly increased in patients with CS comp...
Human heat shock protein 27 (Hsp27, HspB1) is an anti-apoptotic protein characterized for its tumorigenic and metastatic properties, and now referenced as a major therapeutic target in many types of cancer. Hsp27 biochemical properties rely on a structural oligomeric and dynamic organization. Downregulation by small interfering RNA or inhibition with dominant-negative mutant have proven their efficiency to counteract the anti-apoptotic and protective properties of Hsp27. In this study, we report the isolation and characterization of Hsp27-targeted molecules interfering with its structural organization. Using the peptide aptamer (PA) strategy, we isolated PAs that specifically interact with Hsp27 and not with the other members of the small heat shock protein family. In mammalian cell cultur...
Peptide sequences such as lysine-arginine-serine-arginine (KRSR) selectively bind transmembrane proteoglycans (e.g. heparin sulfate) of osteoblasts (bone-forming cells) and are, therefore, actively being investigated for orthopedic applications. Further, nanophase materials (or materials with grain or particle sizes less than 100 nm) are promising new materials that promote new bone growth more than compared to conventional (that is, micron grain or particle size) materials. To combine the above two promising approaches for improving orthopedic implants, the objective of this in vitro study was to functionalize titanium (Ti) surfaces (both nanophase and conventional) with KRSR peptides and study their osteoblast cell adhesive properties. Materials were characterized by X-ray photoelectron ...
A series of [60]fullerene-substituted phenylalanine (Baa) and lysine derivatives have been prepared by the condensation of 1,2-(4prime-oxocyclohexano)fullerene with the appropriately protected (4-amino)phenylalanine and lysine, respectively. Conversion of the imine to the corresponding amine is achieved by di-acid catalyzed hydroboration. The reduction of the imine is not accompanied by hydroboration of the fullerene cage. The [70]fullerene phenylalanine derivative has also been prepared as have the di-amino acid derivatives. The compounds were characterized by MALDI-TOF mass spectrometry, UV/Vis spectroscopy, and cyclic voltammetry. 1H and 13C NMR spectroscopy allowed the observation of diastereomers. Fullerene-substituted peptides may be synthesized on relatively large scale by solid-pha...
Abstract In 46 febrile neutropenic patients who had undergone haematopoietic stem cell transplantation, the fluorescence in situ hybridisation using peptide nucleic acid probes (PNA FISH), Gram stain/acridine orange leukocyte cytospin (Gram/AOLC), and differential time to positivity (DTP) methods were performed for detection of catheter related bloodstream infections (CRBSIs). As compared with the DTP method (which detected 11 patients with CRBSI), the PNA FISH and the Gram/AOLC methods detected ten of 11 CRBSI patients, resulting in a sensitivity, specificity, negative predictive value and positive predictive value of 91%, 100%, 97% and 100%, respectively, for the PNA FISH method as well as for the Gram/AOLC method.
Apelin is a peptide known as the ligand of the G-protein-coupled receptor APJ. Several active apelin forms exist such as apelin-36, apelin-17, apelin-13, and the pyroglutamated form of apelin-13. Apelin and APJ are expressed in the central nervous system, particularly in the hypothalamus and in many peripheral tissues. Apelin has been shown to be involved in the regulation of cardiovascular and fluid homeostasis, food intake, cell proliferation, and angiogenesis. In addition to be an ubiquitous peptide, apelin is also produced and secreted by adipocytes and thus considered as an adipokine. This has opened a new field of investigation establishing a link between apelin and metabolic disorders (obesity, type 2 diabetes, etc.) which is the focus of the present review. Several studies, but not...
Abstract in english Functional properties of soy proteins for food are closely related to the composition of their storage protein subunits. Using base excision sequence scanning (BESS), we show that the absence of the A4 peptide in the G4 glycinin subunit of the soybean (Glycine max L.) cultivar Enrei was caused by the same point mutation in the Gy4 gene as previously reported in the soybean cultivar Raiden. Although the genetic relationship between Raiden and Enrei is not known, the same p (more) oint mutation in their Gy4 genes may indicate that they probably share a related origin. The application of BESS to identify single nucleotide polymorphisms (SNPs) as co-dominant markers for marker-assisted selection (MAS) of a recessive null allele is also discussed.
Exposure control at the operating Nuclear Power Station is a major concern. TAPS Unit-4 is the first Pressurized Heavy Water Reactor of 540 MWe electrical capacity. This unit was made critical on March 6, 2005. In-depth review of radiation safety was done to identify the impact of design modification on dose rates at various locations and on the equipment's. Problems encountered in controlling the dose rates in 220 MWe electrical are eliminated by appropriate design modifications. Due to higher capacity of the unit there are design changes in major systems such as reactor core, primer heat transport system, moderator system, reactor regulation and protection systems. Reactor operations and maintenance activities during shut down contributes to exposure of the employees. Based on the experience gained in the operation of 220 MWe, design modifications incorporated in TAPS unit-4 and dose rate measurements carried out at 90 % ...
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 less potent inhibitors, reaching maximal ...
Spider venoms provide a highly valuable source of peptide toxins that act on a wide diversity of membrane-bound receptors and ion channels. In this work, we report isolation, biochemical analysis, and...Full Text Available
BackgroundOur previous studies indicate that either PEP-1-superoxide dismutase 1 (SOD1) or PEP-1-catalase (CAT) fusion proteins protects myocardium from ischemia-reperfusion-induced...Full Text Available
Several early genes of murine cytomegalovirus (MCMV) encode proteins that mediate immune evasion by interference with the major histocompatibility complex class I (MHC-I) pathway of antigen presentation...Full Text Available
The management of CNS tumors is limited by the blood-brain barrier (BBB), a vascular interface that restricts the passage of most molecules from the blood into the brain. Here we show that phage particles...Full Text Available
With the aim of an experimental check on the validity of the theory of molecular recognition, the authors have carried out the chemical-enzymatic synthesis and cloning of the gene of human calcitonin and also of the genes of antisense polypeptides to human calcitonin and miniproinsulin. It has been shown that recombinant plasmids obtained on the basis of these synthetic genes are capable of ensuring the biosynthesis of the given polypeptides in E. coli cells as hybrid proteins with the IgG-binding domain of staphylococcal protein A.
There are about fifty SET domain protein methyltransferases (PMTs) in the human genome, that transfer a methyl group from S-adenosyl-L-methionine (SAM) to substrate lysines on histone tails or other peptides. A number of structures in complex with cofactor, substrate, or inhibitors revealed the mechanisms of substrate recognition, methylation state specificity, and chemical inhibition. Based on these structures, we review the structural chemistry of SET domain PMTs, and propose general concepts towards the development of selective inhibitors.
Transforming growth factor (TGF)-βs are secreted in large latent complexes consisting of TGF-β, its N-terminal latency-associated peptide (LAP) propeptide, and latent TGF-β...Full Text Available
A cDNA library was constructed from HL60 human promyelocyte poly(A)+ RNA harvested 3 h after induction of macrophage differentiation with 12-O-tetradecanoyl phorbol-13-acetate in the presence of cycloheximide....Full Text Available
CAP18 (an 18-kDa cationic antimicrobial protein) is a granulocyte-derived protein that can bind lipopolysaccharide (LPS) and inhibit various activities of LPS in vitro. The present study examined the...Full Text Available
The IgG response to gp41 (envelope glycoprotein of Mr 41,000) of the human immunodeficiency virus (HIV) was studied with eight synthetic peptides derived from three different regions of the protein....Full Text Available
Low-level lead exposure during early childhood has long been associated with altered neurocognitive development and diminished cognitive functions. Over nine thousand U.S. industrial facilities...Full Text Available
During protein synthesis, aminoacyl-tRNA (aa-tRNA) and release factors 1 and 2 (RF1 and RF2) have to bind at the catalytic center of the ribosome on the 50S subunit where they take part in peptide bond...Full Text Available
DescriptionIron deficiency anaemia is a common problem and may be particularly important to certain groups of vegetarians. This project investigates isolating and identifying iron-binding constituents of meat digests using human Caco-2 cell lines. Stable isotope techniques used to test whether one or more of these compounds enhance iron absorpion in vivo and could therefore be added to vegetarian products to imporve iron nutrition.
TH1 cytokine secretion was examined in response to synthetic peptides of the 85A component of the major secreted, fibronectin-binding antigen 85 complex from Mycobacterium tuberculosis in seven different...Full Text Available
BackgroundThe human endogenous retrovirus HERV-K(HML-2) family is associated with testicular germ cell tumors (GCT). Various HML-2 proviruses encode viral proteins such as Env and...Full Text Available
FMRFamide-related peptides (FaRPs) are a diverse and physiologically important class of neuropepeptides in the metazoa. In insects, FaRPs function as brain-gut neuropeptides and have been immunolocalized...Full Text Available
During this report period our research efforts have concentrated on studies of the dissociation reactions of model peptides and other biologically important molecules. In addition, a considerable amount of research effort has been directed toward improving the apparatus used for laser-ion beam photodissociation. The instrumental improvements include some changes on the original apparatus, but most of this effort involved designing a second generation laser-ion beam photodissociation instrument.
Several examples of the 14-membered, para-bridged ring system of the cyclopeptide alkaloids have been synthesized via an active ester cyclization. The yield of monomeric cyclopeptide varied from 1 to 33% and was affected by the amino acid substitution pattern and amide conformation of the linear peptide precursors. Both the synthetic models and a naturally occurring cyclopeptide alkaloid, ceanothine B, bind monovalent (Li"+) and divalent (Ca"2"+, Mg"2"+) cations. 4 figures, 1 table.
The catecholamine release-inhibitory catestatin [Cts; human chromogranin (Cg) A352-372, bovine CgA344-364] is a vasoreactive and anti-hypertensive peptide derived...Full Text Available
This study focuses on the effects of long-term renin-angiotensin system suppression and/or incretin mimetic therapies on the regulation and binding affinity of GLP-1 to its receptor in the coronary...Full Text Available
Epidermal growth factor (EGF) stimulates adenylyl cyclase in the heart via activation of the stimulatory GTP-binding protein Gs. Therefore, employing peptides corresponding to regions in the cytosolic...Full Text Available
We have purified and characterized two peptides, named KAaH1 and KAaH2 (AaH polypeptides 1 and 2 active on K+ channels, where AaH stands for Androctonus australis Hector),...Full Text Available
The chemical operational concept originally established for the water-steam circuit of Angra II nuclear power plant has undergone several modifications throughout the development of the project. This work discusses the two main modifications giving special attention to the costs involved and analyses the main points and the consequences of such modifications 1 ref., 4 figs., 2 tabs.
PUREX high-level waste (HLW) is contained at the West Valley Demonstration Project (WVDP) in an underground carbon-steel storage tank. The HLW consists of a precipitated sludge and an alkaline supernate. This report describes the system that the WVDP has developed and implemented to resuspend and wash the HLW sludge from the tank. The report discusses Sludge Mobilization and Wash System (SMWS) equipment design, installation, and testing. The storage tank required modifications to accommodate the SMWS. These modifications are discussed as well.
We describe the successful creation of a transjugular intrahepatic portosystemic shunt (TIPS) in a patient with complete situs inversus using a simple modification of the standard TIPS technique.
Hyaluronan (HA), a non-sulfated glycosaminoglycan, is widely used in the clinic for viscosurgery, viscosupplementation, and treatment of osteoarthritis. Four decades of chemical modification...Full Text Available
A shipbuilder is using an electro-magnetic forming system (on loan from NASA) in a development program. " A modification in the design of a metal bending ...
Eukaryotic genomes are packaged in two basic forms, euchromatin and heterochromatin. We have examined the composition and organization of Drosophila melanogaster heterochromatin in...Full Text Available
... growth hormone-like factor from plerocercoids of the tapeworm Spirometra mansonoides is a multifunctional protein. In Parasites and pathogens: ... ...
Phosphorylation is one of the most frequent modifications in intracellular signaling and is implicated in many processes ranging from transcriptional control to signal transduction in innate immunity....Full Text Available
The Multiple Address Processing Unit (MAPU) of the AN/TGC-26 tape relay center was originally designed to process ACP 127 message format. With the advent of JANAP 128 as a standardized message format a pressing need was felt for a MAPU modification to all...
The examples discussed demonstrate that in order to improve further the high-temperature strength properties of (monocrystalline) nickel-base superalloys, it is expedient to follow two parallel routes, namely alloy development, on the one hand, and suitable modifications of the microstructure by appropriate thermal and mechanical treatments, on the other hand. (orig.)
AbstractWe describe the fusion of enhanced green fluorescent protein to the C-terminus of the HsdS DNA sequence-specificity subunit of the Type I DNA modification methyltransferase M.EcoKI....Full Text Available
The effect of treatment with hydrogen, hydrogen sulfide, and steam on the catalytic properties of NaY zeolites has been studied. A mechanism has been proposed for activation of the zeolites, which explains the appearance of Broensted acid centers on modified samples. The influence of modification temperature and the degree of decationization of the zeolites on the promoting capacity of the latter in the cumene cracking reaction has been studied.
A method for the chemical modification of the initial structure of humic acids by acylation with indole-3-acetic acid chloride was developed to increase the biological activity of preparations based on peat and lignite humic acids. The plant growth stimulating effect and the antibacterial activity of the synthesized humic preparations were studied.
Postulated impacts of large energy releases were examined in the light of existing technical information. The magnitudes of direct atmospheric modifications were estimated, and the ecological and economic implications of the modifications were explored. Energy releases from energy centers (10 to 40 power plants at a single site) and individual power plant clusters (1 to 4 power plants) were considered. In the atmosphere the energy will exist initially as increased temperature (sensible heat), moisture (latent heat), and air motion (kinetic energy). Addition of energy could result in increased cloudiness and fog, and changed precipitation patterns. A framework for economic analysis of the impacts of the postulated atmospheric modifications was established on the basis of costs and benefits. Willingness-to-pay was selected as the appropriate measure for valuing each impact. The primary and secondary atmospheric ...
We cloned and characterized horse preproendothelin-2 (PPET-2) cDNA from intestinal tissue. The cDNA encoded 178 amino acids of the PPET-2 polypeptide, in which a 21-amino-acid mature endothelin-2 peptide and a 16-amino acid endothelin-2-like peptide were found. For the open reading frame the correspondence of horse PPET-2 cDNA with those of the ferret, human, dog, mouse and rat was 85.1%, 84.9%, 82.1%, 77.8% and 77.2%, respectively. Analysis of the organ distribution of PPET-2 mRNA by reverse transcription-polymerase chain reaction demonstrated that the kidney, stomach and small intestine are major sites of expression of the PPET-2 gene. Surprisingly, the mRNA is not detected in the large intestine, where high expression is demonstrated in the mouse and rat. This difference may result from the underlying functional differences of the large intestine between a herbivore (horse) and an omnivore (mouse and rat). PMID:15838341
Calcitonin gene-related peptide (CGRP) was localized by an immunocytochemical technique in the thyroid-parathyroid complexes of rat, guinea pig, rabbit, and in normal human thyroids and parathyroids. Human medullary carcinomas and parathyroid adenomas were also studied. In man and all animal species examined CGRP was present in the parafollicular cell, however, in guinea pigs only in small amounts. Except in rabbits, presence of CGRP was demonstrated in nerves of the thyroid and parathyroid capsule as well as in the nerve fibers of the capsular blood vessels. In the thyroid of guinea pigs CGRP was also noted in nerve fibers and in blood vessel walls between follicles. CGRP was also present in the parathyroid glands of rat and man, in nerve fibers localized between parathyroid cells. In rabbit the parafollicular cells between parathyroid cells also expressed CGRP immunoreactivity. No CGRP was noted in the parathyroids of the guinea pig. The proximity of parathyroid ...
The effects of atrial natriuretic peptide (ANP), oxytocin (OT) and vasopressin (AVP) on guanylate cyclase activity and cyclic GMP accumulation were examined, since these hormones appear to be intimately associated with blood pressure and intravascular volume homeostasis. ANP was found to increase cyclic GMP accumulation in ten cell culture systems, which were derived from blood vessels, adrenal cortex, kidney, lung, testes and mammary gland. ANP receptors were characterized in intact cultured cells using {sup 125}I-ANP{sub 8-33}. Specific {sup 125}I-ANP binding was saturable and of high affinity. Scratchard analysis of the binding data for all cell types exhibited a straight line, indicating that these cells possessed a single class of binding sites. Despite the presence of linear Scatchard plots, these studies demonstrated that cultured cells possess two functionally and physically distinct ANP-binding sites. Most of the ANP-binding sites in cultured cells have a ...
A novel single-chain immunotoxin was constructed by combining a CD33-specific single chain Fv (scFv) antibody fragment with an engineered variant of Pseudomonas exotoxin A (ETA). The variant toxin carries the KDEL peptide at its C-terminus, a cellular peptide mediating improved retrograde transport to the endoplasmic reticulum. The purified recombinant fusion protein induced potent apoptosis of the human myeloid cell lines U937, HL-60 and THP-1. Up to 98% of U937 cells were eliminated after treatment for 72 h with a single dose of 500 ng/ml (c. 7 nmol/l). Killing was antigen-specific and occurred by apoptosis. A control protein, consisting of a CD19-specific scFv antibody fragment fused to the ETA-KDEL toxin, failed to induce death of the CD19-negative cell lines U937, HL-60 and THP-1. The CD33-ETA toxin also mediated apoptosis of fresh patient-derived acute myeloid leukaemia cells from bone marrow and peripheral blood. The pronounced ...
Electronic circular dichroism (ECD) of the n-#pi# and #pi# -#pi# transitions of the amide groups in the ultraviolet has become an indispensable tool for qualitative characterization of proteins in solution. Since the existence of such a spectrum (that is, of natural optical activity) comes from the three dimensional interaction of the chromophores in the molecule, CD is exquisitely sensitive to molecular conformation. However, in proteins, the amide transitions available in the near UV are limited in number and are broads and overlapping. Interactions among them yield information about the polymeric backbone, but since such amide electronic excitation are relatively delocalized, the resulting
Experimental investigation data are systematized of free radical states and processes in irradiated proteins. The investigation is performed by the radiospectral methods. Results are discussed in detail of the study of free radicals electronic structure of amino acids, peptides and proteins formed by the action of ionizing radiation. The specificity is stressed of the study of monocrystalls of these compounds by the method of electronic paramagnetic resonance. The nature is also studied of primary centres formed under the effect of radiation on biologically important compounds and their subsequent reactions in solid and liquid solutions. Ion-radical states of different functional groups of the protein molecule are studied. Prospects of the study and the role of anion-radicals in biological processes are discusses.
This paper describes the study of kinetically controlled enzymatic coupling of N- and O-glycopeptide fragments using subtilisin BPN' and two of its variants developed for use in high concentrations of dimethylformamide and in aqueous solution, respectively. Glycosyl amino acids were exploited as the P[sub 1], P[sub 2], P[sub 3], P'[sub 1], P'[sub 2], or P'[sub 3] residue in the enzymatic coupling. Glycosyltransferase-mediated glycosylation of the glycopeptide fragments obtained prior to or after enzymatic peptide bond formation is demonstrated. 19 refs., 5 figs., 1 tab.
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 novel distorted six-coordinated (3N3O) geometry around copper in the A{beta}-Cu{sup ...
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 ...
NMR spectroscopy combined with paramagnetic relaxation agents was used to study the positioning of the 40-residue Alzheimer Amyloid {beta}-peptide A{beta}(1-40) in SDS micelles. 5-Doxyl stearic acid incorporated into the micelle or Mn{sup 2+} ions in the aqueous solvent were used to determine the position of the peptide relative to the micelle geometry. In SDS solvent, the two {alpha}-helices induced in A{beta}(1-40), comprising residues 15-24, and 29-35, respectively, are surrounded by flexible unstructured regions. NMR signals from these unstructured regions are strongly attenuated in the presence of Mn{sup 2+} showing that these regions are positioned mostly outside the micelle. The central helix (residues 15-24) is significantly affected by 5-doxyl stearic acid however somewhat less for residues 16, 20, 22 and 23. This {alpha}-helix therefore resides in the SDS headgroup region with the face with residues 16, 20, 22 and 23 directed away ...
2-Azido[#alpha#-"3"2P]adenosine diphosphate (2-azido[#alpha#-"3"2P]ADP) has been used to photolabel the ADP/ATP carrier in beef heart mitochondria. In reversible binding assays carried out in the dark, this photoprobe was found to inhibit ADP/ATP transport in beef heart mitochondria and to bind to two types of specific sites of the ADP/ATP carrier characterized by high-affinity binding (K/sub d/ = 20 #mu#M) and low-affinity binding (K/sub d/ = 400 #mu#M). In contrast, it was unable to bind to specific carrier sites in inverted submitochondrial particles. Upon photoirradiation of beef heart mitochondria in the presence of 2-azido[#alpha#-"3"2P]ADP, the ADP/ATP carrier was covalently labeled. After purification, the photolabeled carrier protein was cleaved chemically by acidolysis or cyanogen bromide and enzymatically with the Staphylococcus aureus V8 protease. In the ADP/ATP carrier protein, which is 297 amino acid residues in length, two discrete regions extending from Phe-153 to ...
Aminophenpyramine, a derivative of mepyramine (pyrilamine), a typical antagonists of histamine at its H_1 receptor was synthesized and converted into ["1"2"5I]iodoazidophenpyramine, a potential photoaffinity probe for the H_1 receptor. In the dark, reversible binding of this probe to cerebellar membranes occurred with a K/sub d/ of 1.2 x 10"-"1"1 M and a B/sub max/ of 240 fmol/mg of protein and was inhibited by various H_1-receptor antagonists with the expected potencies. These features establish the compound as one of the most potent H_1-receptor antagonists known so far. Upon IV irradiation, 5% of the bound radioactivity was covalently incorporated into cerebellar membrane polypeptides as shown by standard NaDodSO_4/PAGE. Two bands of 47 and 56 kDa were consistently labeled, labeling being prevented by various H_1-receptor antagonists with the expected potencies and stereoselectivity. In the presence of protease inhibitors, labeling of the 56-kDa peptide ...
The effects of a modifier that contains Rare Earths (RE), low melting point alloy (Al-Bi-Sb) and Ca-Si alloy on an ultrahigh carbon steel containing 1.9wt.% C were studied. Microstructure characterization was carried out with optical microscopy (OM) and scanning electronic microscopy (SEM) combined with energy-dispersive spectrometry (EDS). Upon modification, the continuous eutectic carbide network structure was broken up and changed to a partly isolated and finer blocky structure in the as-cast alloy. Differential scanning calorimetry (DSC) revealed that the eutectoid temperature increased and the eutectic temperature decreased for the modified alloy. Modification also improved the impact toughness of the tempered steel, with a significant increase from 6.5 to 12.6Jcm^-^2, despite the har...
Please cite this paper as: Ectopic mineralization of connective tissue in Abcc6-/- mice: effects of dietary modifications and a phosphate binder - a preliminary study. Experimental Dermatology 2008; 17: 203-207. Abstract: Pseudoxanthoma elasticum (PXE), a heritable multisystem disorder, is caused by mutations in the ABCC6 gene. We have developed a murine model for PXE by targeted inactivation of the corresponding mouse gene. A feature of this mouse model is ectopic mineralization of connective tissue capsule surrounding the bulb of vibrissae. This study was designed to investigate the effect of dietary sevelamer hydrochloride (Renagel), a phosphate binder, and specific mineral modifications on ectopic mineralization of connective tissue in Abcc6-/- mice. Three groups were fed a specific di...
Synthetic chemistry originally developed for the manufacture of chemically stable silica polyamine composites was adapted for the modification of fused silica capillaries for application in CE. Polyethyleneimine (PEI) and polyallylamine (PAA) were covalently bonded to the interior surface of fused silica capillaries utilizing 3-chloropropyltrichlorosilane (CPTCS) or 3-glycidoxypropyl-trimethoxysilane (GPTMS) to anchor the polymers to the surface. The surface-bound polymers were subsequently quaternized using methyl iodide (MeI). The resulting modified capillaries were studied using CE, and were shown to provide reproducible, stable, and robust anodic EOF throughout the pH range of 2-10. Surface modifications utilizing CPTCS could be rinsed with up to 6 M HCL or 1 M NaOH without significant...
Tree-level scattering amplitudes of longitudinally polarized electroweak vector bosons in the Standard Model are calculated using Mathematica package Feyncalc. The modifications of low-energy theorems for longitudinally polarized W and Z in the Standard Model are discussed.
Cytosine methylation in DNA is a major epigenetic signal, and plays a central role in propagating chromatin status during cell division. However the mechanistic links between DNA methylation...Full Text Available
Post-transcriptional nucleoside modifications fine-tune the biophysical and biochemical properties of transfer RNA (tRNA) so that it is optimized for participation in cellular processes. Here we report...Full Text Available
A facile synthetic protocol for the production of neomycin B derivatives with various modifications at the 5″ position has been developed. Structural activity relationship (SAR) against...Full Text Available
The aspartate receptor involved in chemotaxis is modified by methyl esterification at four distinct glutamate residues during the adaptive response of this receptor. To explain the high degree of specificity...Full Text Available
The blood beryllium lymphocyte proliferation test (BeLPT) is a modification of the standard lymphocyte proliferation test that is used to identify persons who may have chronic beryllium disease. A major...Full Text Available
The technology of gene targeting through homologous recombination has been extremely useful for elucidating gene functions in mice. The application of this technology was thought impossible in the large...Full Text Available
Experienced users of the Clarion cochlear implant were tested acutely with the HiResolution (HiRes) and HiRes Fidelity120 (F120) processing strategies. Three psychophysically-based tests were...Full Text Available
The in vivo sensitivity of Plasmodium falciparum to chloroquine and sulfadoxine/pyrimethamine was evaluated in children under 5 years of age in two areas of southern Nigeria in 1987. A modification...Full Text Available
Methylation of RNA by methyltransferases is a phylogenetically ubiquitous post-transcriptional modification that occurs most extensively in transfer RNA (tRNA) and ribosomal RNA (rRNA). Biochemical...Full Text Available
How sensory organization for postural control matures in children is not clear at this time. The present study examined, in children aged 7 to 11 and in adults, the postural control modifications in...Full Text Available
BackgroundTransarterial chemoembolization (TACE) therapy is an effective locoregional treatment in hepatocellular cancer (HCC) patients. For early modification of therapy, markers...Full Text Available
Protein modifications such as phosphorylation are often studied by two-dimensional gel electrophoresis since the perturbation in the protein’s pI value is readily detected by this method....Full Text Available
Phosphoramidite reagents can phosphitylate guanine bases at the O6-position during solid phase synthesis and serious chain cleavage occurs if the base phosphitylation is not eliminated before the iodine/water...Full Text Available
A dielectric liquid having entrained bubbles of gas or vapor is subjected to an electric field applied between spaced electrodes (112, 116) which generates microdischarges (and thus plasma) within the bubbles, allowing modification of the properties of th...
The epigenome consists of non–sequence-based modifications, such as DNA methylation, that are heritable during cell division and that may affect normal phenotypes and predisposition...Full Text Available
Low membrane permeability is one of the major obstacles to the successful cryopreservation of zebrafish embryos. The aim of the present study was to explore if this could be overcome by yolk...Full Text Available
Probabilities of flucton production have been calculated for the 1p-shell nuclei and its modification by the Yastrov method. The results obtained are in a qualitative agreement with the data resulting from the analysis of experiment in an assumption of a flucton mechanism of proton-nuclear inclusive reactions with the production of cumulative particles.
We study a rapidly convergent modification of a two-sided method for the approximate integration of a boundary-value problem with parameters in boundary conditions for a system of quasilinear second-order differential equations.
BackgroundIncreasing evidence demonstrates that stem cells maintain their identities by a unique transcription network and chromatin structure. Opposing epigenetic modifications...Full Text Available
Nucleoside 3'-phosphoramidite and chlorophosphite reagents have been found to react with the lactam function of guanine. This reaction caused unsatisfactory results when oligodeoxyribonucleotides containing...Full Text Available
Bacterial processes in soil, including biodegradation, require contact between bacteria and substrates. Knowledge of the three-dimensional spatial distribution of bacteria at the microscale is necessary...Full Text Available
Multiglycosides of Tripterygium wilfordii Hook f (GTW), a Chinese herb-derived medicine used as a remedy for rheumatoid arthritis, are considered to be a reversible anti-fertility drug...Full Text Available
Evidence is presented for a distinctive type of hippocampal synaptic modification [previously described for a molluscan gamma-aminobutyric acid (GABA) synapse after paired pre- and postsynaptic excitation]:...Full Text Available
Circuit modification associated with learning and memory involves multiple events, including the addition and remotion of newborn cells trough adulthood. Adult neurogenesis and gliogenesis were mainly...Full Text Available
The interior of 237 nm spherical vinylsilsesquioxane nanoparticles has been covalently modified and their surface functionalized under mild conditions to yield a novel type of hybrid silsesquioxane...Full Text Available
BackgroundPopulation densities of many species throughout the world are changing due to direct persecution as well as anthropogenic habitat modification. These changes may induce...Full Text Available
Artifacts in two-dimensional electrophoresis (2-DE) caused by the presence of salts in isoelectric focusing (IEF) have been previously described as a result of increasing conductivity and inducing electroosmosis....Full Text Available
The modification of a Ford 7600 turbocharged diesel engine to a dual fuel engine using methane as the supplementary fuel has been carried out. The paper describes the preliminary work of dual fuel control. Two systems are examined and their behaviour is presented.
Methodologies are given for conducting studies to discover and map break deformations in coal strata using various modifications on radiometry, together with the field for their use. Results that were obtained using the IKS-50 device are given.
The recovery of schistosome cercariae from natural waters has been limited by variations in turbidity and in the accuracy of recovery with different techniques. A modification of the Rowan vacuum paper...Full Text Available
ObjectiveThe aim of this study was to ascertain whether all cervical cancer patients who received adjuvant concurrent chemoradiation (CCRT) for high risk of treatment failure after...Full Text Available
Seven high-school trainees each conducted training sessions with two profoundly retarded children. Each trainee was asked to teach one child to follow the instruction "Bring ball" and the other child...Full Text Available
Modifications of the design and calibration procedure of a diffusion porometer permit determinations of stomatal resistance which agree well with results obtained by leaf energy balance. The energy...Full Text Available
The consequences of structural modifications at the 5'-OH ribofuranotide moiety of quinoline modified B12 derivatives are discussed in regard of the coordination chemistry, the electrochemical properties and the biological behaviour of the compound. PMID:21850334
An approach to generate mimics of phosphorylated serine proteins chemically through site-specific sulfonation of cysteine is presented. This chemical modification is reversible in the presence of reducing agent and therefore is analogous to the kinase/phosphatase system used in nature. PMID:21717004
RNA is involved in a variety of chromatin modification events, ranging from large-scale structural rearrangements to subtle local affects. Here, we extend the evidence for RNA–chromatin interactions...Full Text Available
DNA replication programs have been studied extensively in yeast and animal systems, where they have been shown to correlate with gene expression and certain epigenetic modifications. Despite the conservation...Full Text Available
BackgroundHistone post-translational modifications are critical for gene expression and cell viability. A broad spectrum of histone lysine residues have been identified in yeast...Full Text Available
PurposeCataract is the leading cause of blindness and is associated with oxidative damage and protein modification in the lens. In the present study, we have employed proteomic and...Full Text Available
Numerous xenobiotics, including therapeutics agents, are substrates for bioactivation to electrophilic reactive intermediates that may covalently modify biomolecules. Selective estrogen receptor...Full Text Available
Two field-adapted colorimetric methods for measuring the antimalarial drug chloroquine in urine are described. Both are modifications of the method of Saker and Solomons for screening urine for phencyclidine...Full Text Available
BackgroundProteins may evolve through the recruitment and modification of discrete domains, and in many cases, protein action can be dissected at the domain level. PDZ domains are...Full Text Available
The effects of thiol-specific reagents on the amplitude of the electro-olfactogram (E.O.G.) responses elicited from frog olfactory mucosa by pulses of odorant vapours was studied. The impermeant thiol-specific...Full Text Available
The purpose of this report is to describe the sampling approaches, modifications made to the 100 Area and 300 Area component of the RCBRA Sampling and Analysis Plan, summarize validation efforts, and provide sample identification numbers.
The possibility of surface modification of high-speed steel cutting tool by means of vacuum-plasma treatment including ion nitriding in gas plasma followed by the deposition of wear resistant (Ti, Al)N coatings in metal-gas plasma of a vacuum arc discharge is studied. The regularities of nitrided layer formation and the structure of these layers under various operation conditions of cutting tool are investigated. Optimum conditions of vacuum-plasma treatment providing the best wear resistance of cutting are determined
This text-book (electronic book - multi-media CD-ROM) constitutes a course-book - author's collection of lectures. It consists of 13 lectures in which the reader acquaints with the basis of radiobiology: Introduction to radiobiology; Physical fundamentals of radiobiology; Radiation of cells; Modification of radiation damage of cells; Reparation of radiation damage of cells; Radiation syndromes and their modification; Radiation injury; Radiation damage of tissues; Effect of radiation on embryo and fetus; Biological effects of incorporated radionuclides; Therapy of acute irradiation sickness; Delayed consequences of irradiation; Radiation oncology and radiotherapy. This course-book may be interesting for students, post-graduate students of chemistry, biology, physics, medicine as well as for teachers, scientific workers and physicians. (author)
The results of theoretical and experimental investigations, describing the effect of ionizing radiation on wood and its main components and methods for production of wood-plastic composites by means of radiation-induced chemical modification are generalized. Domestic and foreign experience in their production is systematized; physico-mechanical characteristics of new material, simulation and calculation of irradiating devices, as well as calculation and experimental study of #gamma#-radiation attenuation both by wood material and by wood of different species are given. Gamma sources ("6"0Co isotope, a hot loop of a nuclear reactor) as well as electron accelerators are considered as ionizing radiation sources.
The uranium target of a gas jet transport system for fission products has been modified by the addition of an aluminum cover foil. The new modification allows fission fragments of low mass to enter a continuous chemistry system while heavier fragments are stopped in the aluminum. The elimination of the heavier homologues allows development of simpler and faster chemical separation procedures. In addition, since the lighter fragments are slowed down by the cover foil a smaller target chamber can be used. This leads to a reduction in system holdup time.
The uranium target of a gas jet transport system for fission products has been modified by the addition of an aluminum cover foil. The new modification allows fission fragments of low mass to enter a continuous chemistry system while heavier fragments are stopped in the aluminum. The elimination of the heavier homologues allows development of simpler and faster chemical separation procedures. In addition, since the lighter fragments are slowed down by the cover foil a smaller target chamber can be used. This leads to a reduction in system holdup time. (orig.).
Abstract. The modification of kaon and antikaon properties in the interior of (proto-)neutron stars is investigated using a chiral SU(3) model. The parameters of the model are fitted to nuclear-matter saturation properties, baryon octet vacuum masses, hyperon optical potentials and low-energy kaon-nucleon scattering lengths. We study the kaon/antikaon medium modification and explore the possibility of antikaon condensation in (proto-)neutron star matter at zero as well as finite temperature/entropy and neutrino content. The effect of hyperons on kaon and antikaon optical potentials is also investigated at different stages of the neutron star evolution.
The increasing environmental concern and promotion of ''green processes'' are forcing the substitution of traditional acid and base homogeneous catalysts by solid ones. Among these heterogeneous catalysts, zeolites and zeotypes can be considered as real ''green'' catalysts, due to their benign nature from an environmental point of view. The importance of these inorganic molecular sieves within the field of heterogeneous catalysis relies not only on their microporous structure and the related shape selectivity, but also on the flexibility of their chemical composition. Modification of the zeolite framework composition results in materials with acidic, basic or redox properties, whereas multifunctional catalysts can be obtained by introducing metals by ion exchange or impregnation procedures...
The adsorption properties of four samples of the #alpha#-modification of boron nitride (#alpha#-BN) were investigated by the gas-chromatographic method. According to the electron microscopy data, the #alpha#-BN particles possess the shape of thin plates. An #alpha#-BN sample prepared from magnesium polyboride, is the most uniform adsorbent. For a series of n-alkanes, benzene, and alkyl benzenes, by testing the #alpha#-BN samples one has obtained the retained volumes (Henry constants) and the values of the differential adsorption heat, which are close to those of the surface zero filling. These thermodynamic characteristics of adsorption have shown that the #alpha#-BN, line the graphitized thermal carbon black, is not a specific adsorbent.
Amyloid precursor protein (APP), a key protein in pathogenesis of Alzheimer's disease (AD), is a type I transmembrane protein which can be cleaved by b- and g-secretase to release the amyloidogenic b-amyloid peptides (Ab) and the APP intracellular domain (AICD). While Ab has been widely believed to initiate pathogenic cascades culminating AD, the physiological functions and regulations of AICD remain elusive. In present study, endogenous AICD was demonstrated to be increased by canonical Wnt signal. Instead of due to g-secretase activity, enhanced AICD expression was found due to the increased protein stability by Wnt/b-catenin. b-Catenin was demonstrated to be an associating partner of AICD, capable of promoting AICD mediated transcriptional activity. Investigation by AICD mutants proved ...
A bioartificial kidney, which is composed of a membrane cartridge with renal epithelial cells, can substitute important kidney functions in patients with renal failure. A particular challenge is the maintenance of monolayer integrity and specialized renal epithelial cell functions ex vivo. We hypothesized that this can be improved by electro-spun, supramolecular polymer membranes which show clear benefits in ease of processability. We found that after 7?d, in comparison to conventional microporous membranes, renal tubular cells cultured on top of our fibrous supramolecular membranes formed polarized monolayers, which is prerequisite for a well-functioning bioartificial kidney. In future, these supramolecular membranes allow for incorporation of peptides that may increase cell function even further. PMID:20715132
Abstract Acid-treated cobia (Rachycentron canadum) skin was extracted in a retort (121C) to obtain retorted skin gelatin hydrolysates (RSGHs) containing antioxidant peptides with noticeable antioxidant properties. To improve the antioxidant activity of cobia RSGHs, five processing factors including alkali concentration, alkali pretreatment time, phosphoric acid concentration (PC), water/skin ratio (WS) and retorting time (RT) in RSGH production were screened using a fractional factorial design to identify critical factors. It indicated that PC, WS and RT had significant effects on ,-diphenyl--picrylhydrazyl (DPPH) scavenging by RSGHs. Subsequently, the optimization of PC, WS and RT on the DPPH scavenging of RSGHs was studied using a central composite design to collect data that resulted in...
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...
Endogenous opioid peptides (EOP) are molecules affecting many biological functions influencing productive and reproductive performance. They increase in stress conditions and interact with specific opioidergic receptors (OR): delta, kappa and mu. Several studies in other animal species suggest that they can also affect sperm cell motility. In fish the ionic external environment modulates the increase of intracellular calcium ion that is required to activate sperm motility after spawning. In mammals OR are functionally associated to calcium channels and in fishes calcium is highly required for fish sperm activation. In this study the presence of OR on spermatozoa of two Perciform fish, the sharpsnout seabream (Diplodus puntazzo, family Sparidae) and the European sea bass (Dicentrarchus labr...
Abstract Many solute carrier transporters that interact with anticancer agents and contribute to their pharmacokinetics have been shown to be differentially upregulated in cancer cells as a result of adaptive response to altered nutritional requirements. This review focuses on pathophysiological function of membrane transporters responsible for the influx of physiological substances including oligopeptides, amino acids, and organic cations and anions, and summarizes the recent knowledge regarding mechanisms in their gene expressions. Broad substrate specificity of enhanced oligopeptide H+/peptide cotransporter 1 activity in cancer cells is useful for tumor tissue-specific delivery of chemotherapeutic agents and positron emission tomography diagnostic probes. Amino acid transporters such as...
Plasmid pRK404-a smaller derivative of RK2-is a tetracycline-resistant broad-host-range vector that carries a multiple cloning site and the lacZ(alpha) peptide that enables blue/white selection for cloned inserts in Escherichia coli. We present herein the complete and annotated sequence of pRK404 and three related vectors-pRK437, pRK442, and pRK442(H). These derivatives have proven to be valuable tools for genetic manipulation in Gram-negative bacteria. The knowledge of their complete sequences will facilitate efficient future engineering of them and will enhance their general applicability to the design of genetic systems for use in organisms for which new genomic sequence data are becoming available.
Aberrant amyloid-b peptide (Ab) accumulation along with altered expression and function of nicotinic acetylcholine receptors (nAChRs) stand prominently in the etiology of Alzheimer's disease (AD). Since the discovery that Ab is bound to a7 nAChRs under many experimental settings, including post-mortem AD brain, much effort has been expended to understand the implications of this interaction in the disease milieu. This research update will review the current literature on the a7 nAChR-Ab interaction in vitro and in vivo, the functional consequences of this interaction from sub-cellular to cognitive levels, and discuss the implications these relationships might have for AD therapies.
Cancer cells recruit monocytes, macrophages and other inflammatory cells by producing abundant chemoattractants and growth factors, such as macrophage colony-stimulating factor (M-CSF/CSF-1) and monocyte chemoattractant protein-1 (MCP-1/CCL2), to promote tumor growth and dissemination. An understanding of the mechanisms that target cancer cells and regulate tumor microenvironment is essential in designing anticancer therapies. Here, we showed that serum amyloid-A (SAA) and cathelicidin (LL-37) stimulated M-CSF and MCP-1 expression with or without lipopolysaccharide (LPS) administration; conversely, lipoxin-A4 (LXA4) and annexin-A1 (ANXA1) inhibited LPS-induced M-CSF and MCP-1 production by human (HepG2) and mouse (H22) hepatocellular carcinoma cells (HCCs). The effects of LXA4, ANXA1, SAA ...
Abstract Under eons of evolutionary and environmental pressure, biological systems have developed strong and lightweight peptide-based polymeric materials by using the 20 naturally occurring amino acids as principal monomeric units. These materials outperform their man-made counterparts in the following ways: 1)-multifunctionality/tunability, 2)-adaptability/stimuli-responsiveness, 3)-synthesis and processing under ambient and aqueous conditions, and 4)-recyclability and biodegradability. The universal design strategy that affords these advanced properties involves -bottom-up- synthesis and modular, hierarchical organization both within and across multiple length-scales. The field of -biomimicry--elucidating and co-opting nature-s basic material design principles and molecular building blo...
Many existing agents for diabetes therapy are unable to restore or maintain normal glucose homeostasis or prevent the eventual emergence of hyperglycemia-related complication. Therefore, agents based on novel mechanisms are sought to complement and extend the current therapeutic approaches. Based on the initial paper research, we focused on active STAT3 as an attractive pharmacological target for type 2 diabetes. The subsequent text mining with a unique query to identify suppressors but not activators of STAT3 revealed the ERK2/STAT3 pathway as a novel diabetes target. The description of ERK2 inhibitors as diabetes target had not been found in our text mining research at present. The mechanism-based peptide inhibitor for ERK2 was identified using the knowledge of the KIM sequence, which ha...
Background: Thyroid-stimulating autoantibodies (TSAb) bind to the thyrotropin receptor (TSHR) extracellular domain, or ectodomain (ECD), comprising a leucine-rich repeat domain (LRD) linked by a hinge region to the transmembrane domain (TMD). The LRD (residues 22???260; signal peptide 1???21) contains two disulfide-bonded loops at its N-terminus. In the crystal structure of the isolated LRD complexed with human TSAb monoclonal antibody (mAb) M22, N-terminal disulfide loop 1 (residues 22???30) could not be determined because of crystal disorder. Nevertheless, present crystal structure data are interpreted to exclude a role for the LRD N-terminal disulfide loops in the TSAb epitope(s), contradicting prior functional evidence of a role for these loops in TSAb function. Materials and Methods: ...
The authors have cloned and determined the entire nucleotide sequence of cDNAs corresponding to the putative {alpha} subunits of the human and rat mast cell high-affinity IgE receptors. Both human and rat cDNAs encode an NH{sub 2}-terminal signal peptide, two immunoglobulin-like extracellular domains (encoded by discrete exons), a hydrophobic transmembrane region, and a positively charged cytoplasmic tail. The human and rat {alpha} subunits share an overall homology with one another and the immunoglobulin gene family, suggesting that they arose from a common ancestral gene and continue to share structural homology with their ligands. In addition, the rat gene is transcribed into at least three distinct forms, each of which yields a somewhat different coding sequence.
Successful electron capture dissociation (ECD) Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) applications to peptide and protein structural analysis have been enabled by constant progress in implementation of improved electron injection techniques. The rate of ECD product ion formation has been increased to match the liquid chromatography and capillary electrophoresis timescales, and ECD has been combined with infrared multiphoton dissociation in a single experimental configuration to provide simultaneous irradiation, fast switching between the two techniques, and good spatial overlap between ion, photon, and electron beams. Here we begin by describing advantages and disadvantages of the various existing electron injection techniques for ECD in FT-ICR MS. We next ...
Summation Copper-64 (T1/2?=?12.7 hours; ?+, 0.653?MeV [17.8 %]; ??, 0.579?MeV [38.4 %]) has decay characteristics that allow for positron emission tomography (PET) imaging and targeted radiotherapy of cancer. The well-established coordination chemistry of copper allows for its reaction with a wide variety of chelator systems that can potentially be linked to peptides and other biologically relevant small molecules, antibodies, proteins, and nanoparticles. The 12.7-hours half-life of 64Cu provides the flexibility to image both smaller molecules and larger, slower clearing proteins and nanoparticles. In a practical sense, the radionuclide or the 64Cu-radiopharmaceuticals can be easily shipped for PET imaging studies at sites remote to the production facility. Due to the versatility of 64Cu, ...
Phage display is effective in screening peptides that mimic venom's neutralizing epitopes. A phage display cyclized heptapeptide library (C7C library) was panned with purified divalent antivenin IgG, which neutralizes Naja naja atra venom (NAV) and Bungarus multicinctus venom (BMV). The selected heptapeptide sequences were aligned with known protein sequences of NAV and BMV in GenBank. One of the four consensus sequences, L/PKSSLL, mimicked the crucial epitope on Loop III of Taiwan cobra cardiotoxin that is associated with the venom's lethal potency. In dot blot analysis, several clones showed varying reactivities for NAV monovalent antivenin and lesser cross-reactions with BMV monovalent antivenin. The KSSLLRN-carrying phage occurred four times in selected clones and showed the strongest ...
Gastrointestinal patches represent a novel multiparticulate drug delivery system able to increase the intestinal absorption of drugs with poor bioavailability. The number of patches to administer is a critical issue since it is related to the surface and drug concentration at the absorption site. The objective of this article is to evaluate the effect of the number of administered patches on the final absorption of leuprolide, a peptide chosen as model drug, assuming complete adhesion of all the devices to the intestinal membrane. The same dose of leuprolide was encapsulated into 2, 4 and 6 patches; the resulting intestinal absorption profiles were measured with the Ussing chamber ex vivo experimental setup and compared between them. The results showed that varying the number of patches, t...
Abstract A 3-month, open-label, single-center study was conducted to determine whether a uniquely formulated and physiologically balanced topical treatment serum containing multiple growth factors, cytokines, peptides, antioxidants and depigmenting agents could improve the visible signs of facial photodamage. Thirty-seven females, aged 32-55 years, with mild to severe, fine and coarse peri-ocular wrinkles were enrolled and completed the study. Subjects applied the treatment serum to the face twice daily for 3 months in conjunction with a basic skincare regimen. Clinical evaluations of photodamage were performed at baseline and months 1, 2 and 3. Cutometer measurements and subject self-assessment questionnaires were also conducted during the study. Clinical evaluations showed statistically ...
Protein hydrogels were prepared by substituting ovalbumin with different concentrations of ethyl vinyl sulfone (EVS) or acrylic acid (AA) and crosslinking with divinyl sulfone (DVS). Fourier transform-infrared (FT-IR) spectroscopic studies confirmed the addition of EVS, AA, and DVS onto the protein. Swelling was assessed as a function of pH in the range of 2.5 to 9.4 and ionic strength. The elastic modulus of the gels was determined in shear and compression. Stress relaxation was assessed in compression. The substituent highly affected swelling and modulus with both hydrogels displaying non-Gaussian behavior in the range of hydrogel environments studied. Acrylic acid substituted ovalbumin exhibited a decreasing modulus with increasing swelling behaving as a polyelectrolyte with low added s...
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.
Using the peptide hormone glucagon and Ab(1-40) as model systems, we have sought to elucidate the mechanisms by which fibrils grow and multiply. We here present real-time observations of growing fibrils at a single-fibril level. Growing from preformed seeds, glucagon fibrils were able to generate new fibril ends by continuously branching into new fibrils. To our knowledge, this is the first time amyloid fibril branching has been observed in real-time. Glucagon fibrils formed by branching always grew in the forward direction of the parent fibril with a preferred angle of 35-40degree. Furthermore, branching never occurred at the tip of the parent fibril. In contrast, in a previous study by some of us, Ab(1-40) fibrils grew exclusively by elongation of preformed seeds. Fibrillation kinetics i...
Banana bunchy top virus (BBTV), family Nanaviridae, genus Babuvirus, is a single stranded DNA virus (ssDNA) that causes banana bunchy top disease (BBTD) in banana plants. It is the most common and most destructive of all viruses in these plants and is widespread throughout the Asia-Pacific region. In this study we isolated, cloned and sequenced a BBTV sample from Hainan Island, China. The results from sequencing and bioinformatics analysis indicate this isolate represents a satellite DNA component with 12 DNA sequences motifs. We also predicted the physical and chemical properties, structure, signal peptide, phosphorylation, secondary structure, tertiary structure and functional domains of its encoding protein, and compare them with the corresponding quantities in the replication initiatio...
Shut Down System - 2 (SDS - 2) of TAPP-3 and 4 works on the principle of rapid injection of gadolinium nitrate poison solution into bulk moderator in calandria using high pressure helium to shut down the reactor. This is a new system, in the context of Indian PHWRs, designed, engineered, commissioned and being operated in TAPP-3 and 4. The system design incorporates passive features such as floating polyethylene ball with ball-ball seat arrangement and locked open isolation ball valves with key interlock arrangement. This arrangement eliminates active valves downstream of poison tanks during SDS - 2 actuation. A series parallel arrangement of fast acting pilot controlled air operated valves, which keep the high pressure helium isolated from poison tanks in poised state, are the only active components. During commissioning and initial period of operation of TAPP-4, problems were encountered and were resolved by suitable modifications and the same were incorporated ...
The existing Tokamak Fusion Test Reactor Neutral Beam system is proposed to be modified for long pulse operation on the Tokamak Physics Experiment (TPX). Day one of TPX will call for one TFTR beamline modified for 1000 second pulse lengths oriented co-directional to the plasma current. The system design will be capable of accommodating an additional co-directional and a single counter directional beamline. For the TPX conceptual design, every attempt was made to use existing Neutral Beam hardware, plant facilities, auxiliary systems, service infrastructure, and control systems. This paper describes the moderate modifications required to the power systems, the ion sources, and the beam impinged surfaces of the ion dumps, the calorimeters, the various beam scrapers, and the neutralizers. Also described are the minimal modifications required to the vacuum, cryogenic, and gas systems and the major modification of replacing the ...
Organic modification of aerogel chemical formulations is known to transfer desirable hydrophobicity to lightweight solids. However, the effects of chemical modification on other material constants such as elasticity, compliance, and sound dampening present a difficult optimization problem. Here a statistical treatment of a 9-variable optimization is accomplished with multiple regression and an artificial neural network (ANN). The ANN shows 95 percent prediction success for the entire data set of elasticity, compared to a multidimensional linear regression which shows a maximum correlation coefficient, R=0.782. In this case, using the Number of Categories Criterion for the standard multiple regression, traditional statistical methods can distinguish fewer than 1.83 categories (high and low elasticity) and cannot group or cluster the data to give more refined partitions. A non-linear surface requires at least 3 categories (high, low, and medium ...
Stearic acid (C{sub 1}8H{sub 36}O{sub 2}) was treated into Ar and Ar-O{sub 2}(10%) pulsed DC discharge created by a cathode-anode confined system. The samples were placed at the floating potential. The results show that the mass variation of the stearic acid samples after Ar-O{sub 2} plasma exposure is more important than the pure Ar plasma treatments. This comportment demonstrate that the oxygen actives species (O and O{sub 2} in all states) strongly enhance the etching process with regards to A{sup *} species, regardless of their concentration. After treatment by Ar and Ar-O{sub 2} plasma, analyses by X-ray diffraction show a significant structural modification of the samples surface, utilizing Ar-O{sub 2} plasma the modification was more pronounced. The chemical composition evolution shows that the acid function is etched preferentially in the beginning of the treatment (about 5 min) and that after 10 min the carbonic chains seems to be ...
Piezoelectric ceramics for acoustic applications have been prepared by mixing the piezoelectric phase Pb{sub 1-1.5x}La{sub x}{open_square}{sub x/2}(Ti{sub 1-y}Zr{sub y})O{sub 3} (PLZT) with variable fractions of Al{sub 2}O{sub 3}. The samples are in form of pellets and polarized at high temperature. After thermal treatment, X-ray diffraction and scanning electron microscopy have been used to determine the phase and morphological modifications. The morphotropic PLZT initial phase disproportionates into modified PLZT and ZrO{sub 2} phases. Using electrical impedance spectroscopy, the resonance frequencies of the composite system have been determined and analyzed. As the Al{sub 2}O{sub 3} volume fractions increase, the resonance frequency and the amplitude of the electrical response both decrease. An interpretation of the role of Al{sub 2}O{sub 3} additions is proposed in terms of phase and microstructure modifications. Using LRC electrical ...
This paper presents a series of structural modifications of soybean oils for lubricant. The reaction was monitored and products were confirmed by NMR and FTIR. The structural modification is carried out in four stages, (1) synthesis of soybean oil isooctyl ester from soybean oil; (2) synthesis of epoxy-soybean oil isooctyl ester from soybean oil isooctyl ester; (3) synthesis of hydroxylated products from epoxy soybean oil isooctyl ester with fatty acid; (4) esterification of the hydroxylated product with anhydride. Rheological behaviour of the products was measured. Pour points of the products (3) were observed as low as -24 C (lauric acid) and -15 C (isooctanoic acid) respectively. When the hydroxyl groups in the products were esterified with and acid anhydride, the pour points were became higher, which were -21 C (lauric acid) and -6 C (isooctanoic acid) without pour point depressant, and -27 C (lauric acid) and -24 C (isooctanoic acid) with ...
S100A4, a member of the Ca(2+)-activated S100 protein family, regulates the motility and invasiveness of cancer cells. Moreover, high S100A4 expression levels correlate with poor patient survival in several cancers. Although biochemical, biophysical, and structural data indicate that S100A4 is a noncovalent dimer, it is unknown if two functional S100A4 monomers are required for the productive recognition of protein targets and the promotion of cell invasion. To address this question, we created covalently linked S100A4 dimers using a glycine rich flexible linker. The single-chain S100A4 (sc-S100A4) proteins exhibited wild-type affinities for calcium and nonmuscle myosin-IIA, retained the ability to regulate nonmuscle myosin-IIA assembly, and promoted tumor cell invasion when expressed in S100A4-deficient colon carcinoma cells. Mutation of the two calcium-binding EF-hands in one monomer, while leaving the other monomer intact, caused a 30-60-fold reduction in binding affinity for ...
The response of Desulfovibrio vulgaris Hildenborough (DvH),a sulphate-reducing bacterium, to nitrate stress was examined usingquantitative proteomic analysis. DvH was stressed with 105 m M sodiumnitrate(NaNO3), a level that caused a 50 percent inhibition in growth.The protein profile of stressed cells was compared with that of cellsgrown in the absence of nitrate using the iTRAQ peptide labellingstrategy and tandem liquid chromatography separation coupled with massspectrometry (quadrupoletime-of-flight) detection. A total of 737 uniqueproteins were identified by two or more peptides, representing 22 percentof the total DvH proteome and spanning every functional category. Theresults indicate that this was a mild stress, as proteins involved incentral metabolism and the sulphate reduction pathway were unperturbed.Proteins involved in the nitrate reduction pathway increased. Increasesseen in transport systems for proline, glycine^ ...
Purpose: Photodynamic therapy (PDT) is based on the interaction of a photosensitizing (PS) agent, light, and oxygen. Few new PS agents are being developed to the in vivo stage, partly because of the difficulty in finding the right treatment conditions. Response surface methodology, an empirical modeling approach based on data resulting from a set of designed experiments, was suggested as a rational solution with which to select in vivo PDT conditions by using a new peptide-conjugated PS targeting agent, neuropilin-1. Methods and Materials: A Doehlert experimental design was selected to model effects and interactions of the PS dose, fluence, and fluence rate on the growth of U87 human malignant glioma cell xenografts in nude mice, using a fixed drug-light interval. All experimental results were computed by Nemrod-W software and Matlab. Results: Intrinsic diameter growth rate, a tumor growth parameter independent of the initial volume of the tumor, was selected as ...
The authors have shown previously that the domain recognizing receptors on activated human platelets is located on the human fibrinogen {gamma} chain between residues 400 and 411. To study the correlation between the structure of this segment of the {gamma} chain and its reactivity toward receptors on ADP-activated human platelets, they designed a series of analogues containing replacements at 9 out of 12 positions. A double substitution of the normal His{sup 400}-His{sup 401} sequence by Ala-Ala reduced the inhibitory potency of the dodecapeptide 3-fold. When Lys{sup 406} was replaced by Arg, the inhibitory potency of the dodecapeptide decreased 15 times. On the other hand, substitution of Ala{sup 408} with Arg increased the inhibitory potency of the dodecapeptide 6-fold. A drastic decrease in the reactivity of the dodecapeptide toward platelet receptors was observed when Val{sup 411} was replaced by leucine or cysteine or tyrosine. A 3-fold decrease in reactivity was noted when ...
PACAP (pituitary adenylate cyclase activating polypeptide) is widely distributed neuropeptide acting via three subtypes of receptors, PAC(1), VPAC(1) and VPAC(2). Here we examined the localisation and nature of PACAP-immunoreactive nerves in the rat thyroid and parathyroid glands and defined the distribution of PAC(1), VPAC(1) and VPAC(2) receptor mRNA's. In the parathyroid gland a large number of nerve fibres displaying PACAP-immunoreactivity were distributed beneath the capsule, around blood vessels and close to glandular cells. Most of the PACAP-nerves were sensory, since they co-stored CGRP (calcitonin-gene-related peptide) and were sensitive to capsaicin-treatment. mRNA's for PAC(1) and VPAC(2) receptors occurred in the parathyroid gland, mainly located in the glandular cells. In the thyroid gland PACAP-immunoreactive nerve fibres were associated with blood vessels, thyroid follicles and parafollicular C-cells. A high degree of co-existence between PACAP and ...
When Silk fibre derived from Bombyx mori, a native biopolymer, was dissolved in highly concentrated neutral salts such as CaCl{sub 2}, the regenerated liquid silk, a gradually degraded peptide mixture of silk fibroin, could be obtained. The silk fibroin nanoparticles were prepared rapidly from the liquid silk by using water-miscible protonic and polar aprotonic organic solvents. The nanoparticles are insoluble but well dispersed and stable in aqueous solution and are globular particles with a range of 35-125 nm in diameter by means of TEM, SEM, AFM and laser sizer. Over one half of the {epsilon}-amino groups exist around the protein nanoparticles by using a trinitrobenzenesulfonic acid (TNBS) method. Raman spectra shows the tyrosine residues on the surface of the globules are more exposed than those on native silk fibers. The crystalline polymorph and conformation transition of the silk nanoparticles from random-coil and {alpha}-helix form (Silk I) into ...
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 ...
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 Glu185 was the residue labeled. Since UDP is a zero-length ...
The variation of surface composition and sintering of the binary Pd{sub 7}Ag{sub 3} nanoparticles prepared by chemical reduction were studied. The composition of the as-prepared Pd{sub 7}Ag{sub 3} nanoparticles across the diameter is inhomogeneous due to different reduction potentials of Pd and Ag. Upon heating, Ag will migrate to the surface because of its lower surface energy. Surface modification results in variation of surface composition during the sintering process. Stearic acid acts as a grain growth inhibitor. The migration of Ag to the surface is suppressed and the sintering is retarded. Modification by polyethylene glycol leads to more migration of Ag atoms from the core to the surface. This makes the nanoparticles easier to sinter.
The variation of surface composition and sintering of the binary Pd_7Ag_3 nanoparticles prepared by chemical reduction were studied. The composition of the as-prepared Pd_7Ag_3 nanoparticles across the diameter is inhomogeneous due to different reduction potentials of Pd and Ag. Upon heating, Ag will migrate to the surface because of its lower surface energy. Surface modification results in variation of surface composition during the sintering process. Stearic acid acts as a grain growth inhibitor. The migration of Ag to the surface is suppressed and the sintering is retarded. Modification by polyethylene glycol leads to more migration of Ag atoms from the core to the surface. This makes the nanoparticles easier to sinter.
We describe calculations of the energy loss, range, stopping power, multiple scattering, and other related properties of a high-energy heavy-ion beam at any one of a set of beam line elements. A beam line element (e.g., any beam modification, detection, or control device) is characterized by its thickness, areal density, aperture, and function. The loss of multiply scattered particles to any finite-aperture detector is calculated in the small-angle approximation, and the position of the Bragg peak, as given by particles stopping in the second of two ionization chambers used for Bragg curve measurements, is estimated. A general purpose computer program, PROPAGATE, has been written to allow addition, deletion, and modification of the beam line elements used in the calculation and to provide a convenient means of repeating such calculations for arbitrary beam lines. Calculations and experimental measurements are compared and found to be in ...
Abstract We address the fundamental question of matching the rest-frame K-band luminosity function (LF) of galaxies over the Hubble time using semi-analytic models after modification of the stellar population modelling. We include the Maraston evolutionary synthesis models, which feature a higher contribution by the thermally pulsating asymptotic giant branch (TP-AGB) stellar phase, into three different semi-analytic models, namely the De Lucia and Blaizot version of the Munich model, morgana and the Menci model. We leave all other input physics and parameters unchanged. We find that the modification of the stellar population emission can solve the mismatch between models and the observed rest-frame K-band luminosity from the brightest galaxies derived from UKIRT Infrared Deep Sky Survey d...
The discovery that the cosmic expansion is accelerating has been followed by an intense theoretical and experimental response in physics and astronomy. The discovery implies that our most basic notions about how gravity work are violated on cosmological distance scales. One simple fix is the introduction of a cosmological constant into the field equations for general relativity. However, the extremely small value of the cosmological constant, relative to theoretical expectations, has led theorists to explore a wide variety of alternative explanations that involve the introduction of an exotic negative-pressure fluid or a modification of general relativity. Here we briefly review the evidence for cosmic acceleration. We then survey some of the theoretical attempts to account for it, including the cosmological constant, quintessence and its variants, mass-varying neutrinos, and modifications of general relativity, such as scalar-tensor and $f(R)$ ...
The report presents the results of a Gas Research Institute (GRI) program to evaluate the technical and economic aspects of design options proposed by the U.S. Department of Energy (DOE) for reducing the energy consumption of residential ranges and ovens as mandated by the National Appliance Energy Conservation Act (NAECA) of 1987. The study shows that none of the proposed DOE design options are justified except electric ignition for stand-alone cooktops, based on life-cycle costs, loss of consumer utility, safety, technical considerations, or food quality considerations. An individual range uses so little gas during the year (approximately $14/year for a self-cleaning range) that it is difficult to justify any design modification, since the cost of even a simple modification could not be recovered on the basis of gas saved.
A series of modifications which increased the capacity of Canadian Electrolytic Zinc's Valleyfield plant from 220,000 MT/year to 260,000 MT/year during the last decade is discussed, combined with an an overview of the plant's operations. The modifications included modernisation of the waste disposal methods and facilities, such as a new high-density sludge wastewater treatment process, a new process to remove selenium from weak acid solutions and the jarofix process. Roasting capacity also has been improved by recent investments in new cooling coils, rebricking, oxygen enrichment and process automation. In addition to increases in refining capacity, the improvements also enabled the company to minimize its impact on the environment and the community.
Gas and plasma nitriding processes were executed in the magnesium with modification by titanium in search for an effective surface treatment method for magnesium alloys. Magnesium-nitrogen system has completely no solid solution or solubility, so that nitride should be only formed by eutectic reaction in the liquid phase. Hence, magnesium is difficult or nearly impossible to have its surface modified by nitriding. Addition of nitride forming element into magnesium enables us to lower the onset temperature of nitriding. Magnesium-titanium alloys with 1 to 5 wt% are yielded by the bulk mechanical alloying and, subjected to gas nitriding for various process conditions. Successful co-formation of Mg{sub 3}N{sub 2} as well as TiN becomes a proof to demonstrate the possibility of gas/plasma nitriding in the solid-state magnesium with aid of nitride former. (orig.)
The factors affecting the rate of silica leaching in alkaline aqueous media from surface silanized, nanoporous, amorphous, silica gels and from silanized silica gels that have been modified with polyamines to form the previously reported silica polyamine composites (SPCs), BP-1 and BP-2 have been investigated. Silanization with alkyl trichlorosilanes slows the rate of silica leaching relative to the unmodified silica gels. The use of bulkier aryl silanes somewhat decreases the silica leaching under the same conditions. Interestingly, after modification of the silanized silica with poly(allylamine) (PAA) to make BP-1, the leaching increases, but subsequent modification of the SPC with chloroacetic acid to make BP-2, quenches this increase. A mechanism explaining these results is discussed. ...
This study is one element of a larger engineering study effort by WHC to examine the feasibility of irradiated fuel and sludge consolidation in the KW Basin in response to TPA Milestone (target date) M-34-00-T03. The study concludes that up to 11,500 fuel storage canisters could be accommodated in the KW Basin with modifications. These modifications would include provisions for multi-tiered canister storage involving the fabrication and installation of new storage racks and installation of additional decay heat removal systems for control of basin water temperature. The ability of existing systems to control radionuclide concentrations in the basin water is examined. The study discusses requirements for spent nuclear fuel inventory given the proposed multi-tiered storage arrangement, the impact of the consolidated mass on the KW Basin structure, and criticality issues associated with multi-tiered storage.
This study investigated the effect of board type (unmodified vs. MAPE modified) on the surface quality and thickness swelling-water absorption properties of recycled high density polyethylene (HDPE) based wood plastic composites. Additionally, two commercially available coatings (cellulosic coating and polyurethane lacquer coating) were also applied to composite surfaces and their adhesion strength, abrasion and scratch resistance, and gloss values were determined. This study showed that modification of the composites with MAPE coupling agent increased the surface smoothness and reduced the water absorption and thickness swelling of the panels. Abrasion resistance of the composites was also improved through MAPE modification. Regardless of board type, higher scratch resistance and gloss values were observed for polyurethane lacquer coated samples compared to those of cellulosic varnish coated ones. Improvement of adhesion strength was also seen ...
One of the most common types of functions in mathematics, physics, and engineering is a sum of products, sometimes called a partition function. After "normalization," a sum of products has a natural graphical representation, called a normal factor graph (NFG), in which vertices represent factors, edges represent internal variables, and half-edges represent the external variables of the partition function. In physics, so-called trace diagrams share similar features. We believe that the conceptual framework of representing sums of products as partition functions of NFGs is an important and intuitive paradigm that, surprisingly, does not seem to have been introduced explicitly in the previous factor graph literature. Of particular interest are NFG modifications that leave the partition function invariant. A simple subclass of such NFG modifications offers a unifying view of the Fourier transform, tree-based reparameterization, loop calculus, and ...
We consider various modifications of the Weyl-Moyal star-product, in order to obtain a finite range of nonlocality. The basic requirements are to preserve the commutation relations of the coordinates as well as the associativity of the new product. We show that a modification of the differential representation of the Weyl-Moyal star-product by an exponential function of derivatives will not lead to a finite range of nonlocality. We also modify the integral kernel of the star-product introducing a Gaussian damping, but find a nonassociative product which remains infinitely nonlocal. We are therefore led to propose that the Weyl-Moyal product should be modified by a cutoff like function, in order to remove the infinite nonlocality of the product. We provide such a product, but it appears that one has to abandon the possibility of analytic calculation with the new product.
Epigenetic regulations of genes by reversible methylation of DNA (at the carbon-5 of cytosine) and numerous reversible modifications of histones play important roles in normal physiology and development, and epigenetic deregulations are associated with developmental disorders and various disease states, including cancer. Stem cells have the capacity to self-renew indefinitely. Similar to stem cells, some malignant cells have the capacity to divide indefinitely and are referred to as cancer stem cells. In recent times, direct correlation between epigenetic modifications and reprogramming of stem cell and cancer stem cell is emerging. Major discoveries were made with investigations on reprogramming gene products, also known as master regulators of totipotency and inducer of pluoripotency, na...
Lateral plume dispersion in deep river valleys during neutral and stable lapse rate conditions can be exceptionally high due to the intense horizontal turbulence generated by prominent variations in the width, orientation and surface roughness of the valley walls. Use of the standard Gaussian dispersion equation to represent this enhanced lateral plume spread in a narrow valley may be inappropriate since consideration should also be given to the restriction of the horizontal plume spread due to impingement against the valley walls. The basic concept employed in the modification of the Gaussian dispersion equation was to assume that multiple eddy reflections occur between the valley walls in a manner similar to the vertical eddy reflections between the ground plane and an inversion layer aloft. The expressions are developed, but no attempt has been made to validate them with actual measured field data. 4 references, 3 figures, 1 table.
Carbon black is widely used as an active filler in the rubber industry to improve the physical properties of rubber. The surface energy of carbon black is high compared to that of various elastomers like styrene?butadiene rubber (SBR), butadiene rubber (BR) and ethylene?propylene?diene rubber (EPDM). The work aims at reducing the surface energy of carbon black by modifying its surface for application especially in rubber blends. The present paper looks into the possibility of using plasma polymerisation of acetylene as a surface modification technique for carbon black in comparison with silica. Thermogravimetric analysis, wetting behaviour with various liquids of known surface tension and time of flight secondary ion mass spectrometry (ToF-SIMS) were used to characterise the carbon black b...
Luminescence properties of SiAlON phosphors codoped with Ca and Yb were investigated by changing the host lattice composition. These modifications of the host lattice were obtained by replacing Si-N bonds by Al-N and Al-O bonds. Their photoluminescence (PL) and cathodoluminescence (CL) properties were measured and compared with each other. PL allows observing the influence of the host lattice modifications by measuring wider areas. CL can excite all luminescent centers, in particular the UV luminescence centers, even if their amount is small. Thus, two additional peaks in the ultraviolet and infrared regions were observed in CL, which is not observed by PL. This work suggests that the combination of PL and CL gives more understanding about the luminescence of SiAlON phosphors, in particular the role of the secondary phases on their properties.
Excitation of low temperature helium or helium/water plasma and subsequent exposure to air of polyacrylonitrile (PAN) ultrafiltration membranes was used to hydrophilize the surface of these materials. We analyzed the effectiveness of this approach as a function of plasma operating variables including gas phase composition, plasma power, treatment time and system pressure. Following the changes in physical and chemical composition of the PAN surface resulting from these modifications was a major aspect of this work. Techniques such as the captive bubble contact angle method, ellipsometry, ESCA, and FTIR-ATR were all used. In addition, the formation and life-time of peroxides during these processes were determined. At low powers (<25W) and short treatment periods ({<=}30 sec), the main chemical conversion of PAN surfaces was simultaneous hydrophilization and stabilization via PAN cyclization. Relatively small water permeability changes were observed as a result ...
Considerable interest has focused recently on the use of lignocellulosic fibers as a reinforcement for thermoplastic polymers. The combination of these dissimilar materials, however, is characterized by a widespread incompatibility that leads to a weak fiber/polymer interface and poor performance properties for the composite. In an effort to improve compatibility a number of fiber surface modification approaches have been investigated including plasma, ozone, and polymer grafting treatments. Evaluation of adhesion improvements has been complicated by processing variables that are difficult to control. This paper will discuss the use of the-micro-debond test in quantifying the interfacial shear strength (ISS) in wood fiber/polystyrene composites. Wood fibers were modified to different degrees with styrene-maleic anhydride copolymers that varied in their composition. The effect of fiber modification on surface energetics was determined using ...
Commercial rolled magnesium sheets of alloys AZ31 (Mg-3 mass%Al-1 mass%Zn) and ZE10 (Mg-1 mass% Zn-<1 mass% Rare Earths) in O-temper condition were used for blanking experiments near room temperature. A serrated fracture surface can be observed in case of AZ31 but not in case of ZE10. During the shearing process of the AZ31 sheet, many micro cracks parallel to the sheet plane are generated in the shearing zone. These micro cracks lead to the formation of loose particles during the shearing operation, which interfere with further processing of the part and incur additional costs by increasing the scrap rate. It is found that the strong basal texture of this alloy is an important reason for the generation of such serrated cracks. In this paper a new method of selective texture modification i...
Nanoscale islands of Cu_2O have been synthesized on single-crystal SrTiO_3 (100) substrates using oxygen plasma-assisted molecular-beam epitaxy (MBE). Island growth location has been controlled by using an ex situ Ga"+ focused ion beam (FIB) to modify the growth surface in discrete locations prior to island synthesis. The FIB modifications have generated surface topography with lateral dimensions of 150-200 nm. Ex situ atomic force microscopy study after island growth reveals that certain FIB substrate modification and MBE growth condition combinations lead to directed self-assembly of metal oxide islands at the edges of the FIB modified zones.
Nanoscale islands of Cu?O have been synthesized on single crystal SrTiO? (100) substrates using oxygen plasma assisted molecular beam epitaxy (MBE). Island growth location has been controlled by using an ex-situ Ga? focused ion beam (FIB) to modify the growth surface in discrete locations prior to island sythesis. The FIB modifications have generated surface topography with lateral dimensions of 150-200 nm. Ex-situ AFM study after island growth reveals that certain FIB substrate modification and MBE growth condition combinations lead to directed self-assembly of metal oxide islands at the edges of the FIB modified zones.
Focused Ion Beam (FIB) repairs and modifications to integrated circuits have been somewhat limited in the past due to the physical limitations imposed by the nodes of interest being buried under metal layers, the need for multiple layers of FIB generated interconnects, and the like. With the advent of FIB deposited INSULATOR materials, integrated circuit modifications can now be much more complex. The two primary goals of this project were (1) to determine the appropriateness of FIB insulator deposition for aiding FIB connections to metal nodes buried under power busses, and (2) development of a technique to do this. The work presented in this paper includes the development and characterization phases of adding INSULATION DEPOSITION to a FEI 611 FIB system, the problems encountered, their work around, and the aforementioned application of this technology.
Inputs on radiological conditions forms the basis of implementation of effective exposure control to plant personnel in nuclear power station. Radiation monitoring system provides this input to the plant operator as well as to health physics group. Several design modifications have been incorporated in the Radiation Monitoring System at Tarapur Atomic Power Station (TAPS 3 and 4) over the similar systems at Kakrapar Atomic Power Station (KAPS) and Kaiga Generating Station (KGS). The radiological monitoring systems installed at TAPS unit 3 and 4 includes on line Radiation Data Acquisition System (RADAS), Emergency sampling system, effluent monitoring system and environmental monitoring system. The design changes and the versatile use of these systems are presented in this paper. (author)
Neutron stars are sensitive laboratories for testing general relativity, especially when considering deviations where velocities are relativistic and gravitational fields are strong. One such deviation is described by dynamical, Chern-Simons modified gravity, where the Einstein-Hilbert action is modified through the addition of the gravitational parity-violating Pontryagin density coupled to a field. This four-dimensional effective theory arises naturally both in perturbative and non-perturbative string theory, loop quantum gravity, and generic effective field theory expansions. We calculate here Chern-Simons modifications to the properties and gravitational fields of slowly spinning neutron stars. We find that the Chern-Simons correction affects only the gravitomagnetic sector of the metric to leading order, thus introducing modifications to the moment of inertia but not to the mass-radius relation. We show that an observational determination ...
This current work is concerned with the development of polypropylene composites reinforced with cellulose and cellulignin fibers attained from sugarcane bagasse. Moreover, the fibers were chemically modified by acetylating process and its effects on the fiber/matrix interaction were also evaluated. The chemical modification efficiency was verified by FTIR analysis and the fibers morphological aspects of fibers by SEM. Likewise, the influence of modified fibers content in the composites was studied by mechanical (tensile, shear and flexural tests) and thermal analyses (TGA and DSC). After the chemical modification, the FTIR results showed the appearance of acetyl groups and reduction of OH bonds for all fibers. Together with, SEM characterization showed that the acetylation changed the morp...
New technologies are needed to reduce the current high rate of well abandonment. Improved sweep efficiency, reservoir conformance, and permeability modification can have a significant impact on oil recovery processes. Microorganisms can be used to selectively plug high-permeability zones to improve sweep efficiency and impart conformance control. Studies of a promising microbial system for polymer production were conducted to evaluate reservoir conditions in which this system would be effective. Factors which can affect microbial growth and polymer production include salinity, pH, temperature, divalent ions, presence of residual oil, and rock matrix. Flask tests and coreflooding experiments were conducted to optimize and evaluate the effectiveness of this system. Nuclear magnetic resonance imaging (NMRI) was used to visualize microbial polymer production in porous media. Changes in fluid distribution within the pore system of the core were detected.
The colonization of an implant surface by bacteria is an extremely important medical problem, which often leads to the failure of medical devices. Modern surface modification techniques, such as ion implantation, can confer to the surfaces very different properties from those of the bulk underlying material. In this work, austenitic stainless steel 316 LVM has been superficially modified by Si^+ ion implantation. The effect of surface modification on the biocompatibility and bacterial adhesion to 316 LVM stainless steel has been investigated. To this aim, human mesenchymal stem cells (hMSCs), as precursor of osteoblastic cells, and bacterial strains relevant in infections related to orthopedic implants, i.e., Staphylococcus aureus and Staphylococcus epidermidis, have been assayed. For the ...
In previous work, several significant improvements in the measurement of distillation curves for complex fluids were introduced. The modifications to the classical measurement provide for (1) temperature and volume measurement(s) of low uncertainty, and most important, (2) a composition-explicit data channel in addition to the usual temperature?volume relationship. This latter modification is achieved with a new sampling approach that allows precise qualitative as well as quantitative analyses of each fraction, on the fly. In the new approach, the distillation temperature is measured in two locations. The temperature is measured in the usual location, at the bottom of the take-off in the distillation head, but it is also measured directly in the fluid. We have further modified our developm...
Calculating work-function modifications for flat-lying conjugated molecules on extended metal surfaces using density functional theory (DFT) is an extremely resource intensive task. This prevents fast screening of new molecules for their potential to optimize metal work functions for good electron or hole injection in organic electronic devices. We present a semi-classical model, which avoids that problem. This is achieved by identifying the dominant processes occurring at the interface between metal and adsorbate in the pinning-regime, which are then parameterizing their description using band-structure DFT calculations for a small training set With the resulting interdependent equations at hand, only simple gas-phase calculations are needed to predict the work-function changes induced by new molecules. The model is tested for ten molecules on three different metal surfaces, where it shows excellent agreement with photoelectron spectroscopy data on these systems.
Abstract Surface modification of topography and chemistry in order to achieve a specific water contact angle (CA) has been explored by using a novel combinatorial screening platform. The screening arrays consisted of 507 distinct combinations of micro-topographies and chemical compositions. By performing chemical modifications with 1H, 1H, 2H, 2H perfluoroethyltriethoxy-silane (PFS) and n-octadecyltriethoxysilane (ODS) on standard silicon wafers it was possible to include both superhydrophobic and very hydrophilic pad arrays in the same screening platform. Surfaces modified with PFS were more hydrophobic than surfaces modified with ODS, while the unmodified silicon surfaces were hydrophilic. For the PFS modified surfaces the largest CAs were achieved with a small pillar size of X-=-1-m and...
We consider the embedding of the Standard Model fields in a$(4+d)$-dimensional theory while gravitons may propagate in $d'$ extra, compactdimensions. We study the modification of strengths of the gravitational andgauge interactions and, for various values of $d$ and $d'$, we determine theenergy scale at which these strengths are unified. Special cases where theunification of strengths is characterized by the absence of any hierarchyproblem are also presented.
In both type 1 and type 2 diabetes, pancreatic islet dysfunction results in part from cytokine-mediated inflammation. The ubiquitous eukaryotic translation initiation factor 5A (eIF5A), which is the...Full Text Available
Nucleotide pool sanitizing enzymes Dut (dUTPase), RdgB (dITPase), and MutT (8-oxo-dGTPase) of Escherichia coli hydrolyze noncanonical DNA precursors to prevent incorporation of base...Full Text Available
One requirement of a thermophotovoltaic (TPV) radiator is to efficiently emit photons at high temperatures to TPV cells for conversion to electric power. Because many candidate radiator materials with adequate structural properties display low emissivity, coatings or other surface modifications are required for enhancement of emissivity. Six plasma sprayed coatings and one textured surface demonstrated adequate thermal stability and emittance values of 0.8 or greater. Promising attributes of modified surfaces are identified.
The Montreal Protocol provides the international community with an effective equitable and dynamic mechanism for protecting the ozone layer. The paper uses the Protocol's negotiating history to describe how and why agreement on a particular issue was reached and provides an in-depth analysis of the Protocol's most innovative provisions. The paper discusses international implementation of the Protocol. It concludes with a brief description of recent developments leading up to the Protocol's possible modification in June 1990. (14 refs.).
... Governing Law These terms and conditions of use shall be governed by the laws of Scotland and are subject to the exclusive jurisdiction of the Scottish Courts. 7. Website Policies, Modification and Severability We reserve the right to make changes to this website, our policies and these terms and conditions of use at any time. If any of these conditions shall be deemed invalid, void ...
A novel class of pyrrolidinyl-acetyleneic thieno[3,2-d]pyrimidines has been identified which potently inhibit the EGFR and ErbB-2 receptor tyrosine kinases. Synthetic modifications of the pyrrolidine carbamate moiety result in a range of effects on enzyme and cellular potency. In addition, the impact of the absolute stereochemical configuration on cellular potency and oral mouse pharmacokinetics is described.
By dissolution of iron (2) carbonate in rhenium acid iron (2) perrhenate of the Fe(ReO/sub 4/)/sub 2/x4H/sub 2/O composition is obtained. By the method of thermal analysis the limits of tetra-, dihydrate and anhydrous iron (2) perrhenate stability are revealed. By means of X ray phase and IR spectroscopic analysis methods modification of structure in the process of synthesized salt dehydration is shown.
Laboratory research data is used as the basis for recommendations to be used in selecting a modification regime employing the treatment of clinoptilolite with NS1 to remove mercaptans from natural gas. The dynamic activity of the modified clinoptilolite is seven times greater than the activity of nontreated material.
The optimum of strontium amount for good modification of AK7, AK9, AK11, AK52, AK104 alloys was determined on the base of the analysis of microstructural changes. The stability of the modifier was investigated on the way of successive remelting of billets. The influence of amount of modifier on the impact strength of the alloys was established. (author)
Allianz Global Corporate and Specialty AG, the industrial insurance carriers of Allianz Group and AZT Risk and Technology GmbH, have a lot of experience and a comprehensive database about damage of industrial steam turbines and large-scale power generation turbosets. Sound maintenance concepts are the main loss prevention measure, which will be presented and discussed in detail. Some modifications and additions to existing maintenance concepts are also provided.
The structure of the title compound, Sr-bearing oxonitridoaluminosilicate (Sr-sialon), contains two types of channels running along the a axis, with the three unique Sr atoms...Full Text Available
... Governing LawThese terms and conditions of use shall be governed by the laws of Scotland and are subject to the exclusive jurisdiction of the Scottish Courts. Website Policies, Modification and SeverabilityWe reserve the right to make changes to this website, our policies and these terms and conditions of use at any time. If any of these conditions shall be deemed invalid, void or for any reason ...
2D MEDICI simulator is used to investigate hardening solutions to single-event burnout (SEB). SEB parametric dependencies such as carrier lifetime reduction, base enlargement, and emitter doping decrease have been verified and a p"+ plug modification approach for SEB hardening of power MOSFETs is validated with simulations on actual device structures.
From the numbers of radiographs of the different examinations and the total amount of radiological diagnostics in the GDR their possible modification by new imaging techniques is discussed under the aspects of costs and radiation burden. Film-screen-systems are of special importance, because they also will be most frequently used image recording system in future. The importance of their various properties and parameters, methods of determining these parameters as well as future developments are analyzed from the standpoint of practical requirements.
From the numbers of radiographs of the different examinations and the total amount of radiological diagnostics in the GDR their possible modification by new imaging techniques is discussed under the aspects of costs and radiation burden. Film-screen-systems are of special importance, because they also will be most frequently used image recording system in future. The importance of their various properties and parameters, methods of determining these parameters as well as future developments are analyzed from the standpoint of practical requirements. (author).
This CD-Rom edited by the French scientific and technical committee of the space heating, ventilation and air-conditioning industry (CoSTIC) presents a series of technical files about ventilation and space heating systems with several references to the current regulatory texts. Modifications of the original legislative texts have been integrated to the original texts for a more comfortable reading. Search is performed using diagrams and key-words. (J.S.)
Substantial changes in the radial distribution function of amorphous Si films have been observed in neutron-diffraction studies. The spectra indicate changes in short-range order associated with an approx.11% modification in the bond-angle distribution width. The results allow the first direct comparison of structural and vibrational Raman probes of variations in local order in thin-film amorphous solids. Good agreement is obtained between the measured bond-angle variation and that based on Raman estimates.
For a system of noninteracting electrons scattered by resonant levels of neutral impurities, we show that virial and quasiparticle corrections have nearly equal magnitudes. We propose a modification of the Boltzmann equation that includes quasiparticle and virial corrections and discuss their interplay on a dielectric function. copyright 1997 The American Physical Society.
The wave equation of a spinless tachyon is studied in Schwarzschild space-time. In contrast to earlier approaches to the problem, it is shown that tachyonic static solutions satisfy a simple second-order linear differential equation regardless of the mass of the black hole and the mass parameter of the tachyon. Physical implication of the present approach is discussed. Using Langer modification of the WKB (Wentzel-Kramers-Brillouin) boundary condition an expression similar to the Bohr-Sommerfeld quantization condition is derived.
The Sodium Storage Facility Project Quality Assurance Plan delineates the quality assurance requirements for construction of a new facility, modifications to the sodium storage tanks, and tie-ins to the FFTF Plant. This plan provides direction for the types of verifications necessary to satisfy the functional requirements within the project scope and applicable regulatory requirements determined in the Project Functional Design Criteria (FDC), WHC-SD-FF-FDC-009.
We present a modification of the closed-loop state space model for AO control which allows delays that are a non-integer multiple of the system frame rate. We derive the new forms of the Predictive Fourier Control Kalman filters for arbitrary delays and show that they are linear combinations of the whole-frame delay terms. This structure of the controller is independent of the delay. System stability margins and residual error variance both transition gracefully between integer-frame delays.
Mineral oil based power transmitting fluids, such as automatic transmission fluids, are disclosed which contain 0.05 to 2.0 weight percent of an ester of a thio-bis alkanol and a C/sub 12/-C/sub 50/ hydrocarbon succinic acid or anhydride, the ester being a multifunctional additive providing the properties of friction modification, corrosion inhibition, anti-wear, oxidation inhibition and extreme pressure properties to the fluids.
The authors discuss the consistency (unitarity) of string propagation on the non-compact group SU(1,1) {times} G{sub c} and find the restriction on the level of the Kac-Moody algebra for this propagation to be unitary. They also suggest some modifications to the Virasoro generators and obtain a manifestly unitary string theory.
SummaryThe transcriptional co-repressor SMRT utilizes two major receptor interacting domains (RID1 and RID2) to mediate nuclear receptor (NR) signaling through epigenetic modification....Full Text Available
Presently available relativistic and nonrelativistic effective interactions do not predict the same behavior for the isotope shifts in the Pb region.We analyze this difference and find that it is related to the characteristics of the spin-orbit term used in the parametrizations. We show that a simple modification of the spin-orbit contribution to the nonrelativistic Skyrme functional solves this problem. ((orig.))
> Develoopments which have imporved fuel core quality and reduced production costs are described. These developments in the melting and casting of uranium ingots arei modification of the crucible and knockout-slide assembly, substitution of uncoated crucibles for coated crucibles, and substitution of a one-piece gun barrel mold for a vertically split mold. (N.W.R.)
The hydrogen bonding of ligated water in ferric, high-spin, resting-state substrate complexes of heme oxygenase from Neisseria meningitidis has been systematically perturbed...Full Text Available
We have shown that addition of exogenous delta-aminolaevulinic acid (ALA) to rat pancreatoma AR4-2J cells in culture leads to the increased production of porphobilinogen (PBG) and the accumulation of...Full Text Available
The surface properties of copper-refractory metal (CU-RF) alloy bodies are modified by heat treatments which cause the refractory metal to form a coating on the exterior surfaces of the alloy body. The alloys have a copper matrix with particles or dendrites of the refractory metal dispersed therein, which may be niobium, vanadium, tantalum, chromium, molybdenum, or tungsten. The surface properties of the bodies are changed from those of copper to that of the refractory metal.
A method of auxiliary spectrum is modified so that matrix elements of the reaction matrix in final nuclei are determined by means of algebraic operations alone (inversion of matrices). No differential equations need to be solved; Pauli's exclusion principle is accurately taken into account. A single-particle potential may be of any kind, but a two-particle interaction must have no solid core.
This is a continuation of research that started in July 2007 at the Deep River Science Academy. The research was related to the effects of endplate thickness and misalignment of fuel bundles in the fuel channel on pressure losses of reactor coolant. Based on this research, a new approach to refueling of the CANDU reactor has been developed. It greatly simplifies fuel handling equipment and increases its reliability. It also reduces required staffing, as well as operating and maintenance costs associated with fuel handling. (author)
The management procedure of a large PRISE (Primary-to-Secondary) leakage accident at Loviisa nuclear power plant taking into account the plant modifications which are expected to be realized during 1995-96 is described. The management procedure has been validated by performing thermal hydraulic analyses with the computer code RELAP5/MOD3 and the results from these analyses are also shortly discussed. (4 refs., 6 figs., 1 tab.).
Laser direct-write etching of the refractory metals Mo and W was developed using reactions in chlorine and nitrogen trifluoride vapors. Rate and high spatial resolution are simultaneously optimized using a two-vapor halogenation/development sequence, based on surface modification. Local-area laser chlorination of the metal surface is used to predispose areas to subsequent bulk etching.
Described are the changes to ICD-10-CM and PCS and potential challenges regarding their use in the US for financial and administrative transaction coding under HIPAA in 2013. Using author constructed...Full Text Available
One of the effective methods of deep modification of the surface of steels and alloys is the combination of ion implantation and plasma nitriding. In this work, the long-range effect is demonstrated in the case of combination of the effect of high- and low-energy ions of nitrogen on a martensitic steel for each ion implantation is usually not effective, and a titanium alloy used widely in industry.
We consider a generalization of the DGP model, by adding a second brane with localized curvature, and allowing for a bulk cosmological constant and brane tensions. We study radion and graviton fluctuations in detail, enabling us to check for ghosts and tachyons. By tuning our parameters accordingly, we find bigravity models that are free from ghosts and tachyons. These models will lead to large distance modifications of gravity that could be observable in the near future.
This document presents the details of the implementation of the Site Treatment Plan developed by Ames Laboratory in compliance with the Federal Facilities Compliance Act. Topics discussed in this document include: implementation of the plan; milestones; annual updates to the plan; inclusion of new waste streams; modifications of the plan; funding considerations; low-level mixed waste treatment plan and schedules; and TRU mixed waste streams.
The report describes the following: overview of the Russian power industry; electric power equipment of Russia; power industry development forecast for Russia; clean coal technology demonstration program of the US Department of Energy; reduction of coal TPS (thermal power station) environmental impacts in Russia; and base options of advanced coal thermal power plants. Terms of the application of clean coal technology at Russian TPS are discussed in the Conclusions.
DescriptionEnzymes are natural catalysts that are used increasingly to replace environmentally harmful chemicals and to achieve better catalytic selectivity during pulp and paper processing. The main objective of this project is to identify novel plant enzymes for deeper understanding of the process of fibre formation and for future improvement of the quality parameters of wood fibres. Specific modification of the fibre characteristics will facilitate their use as raw materials for the current pulp and pap [continued...
This article introduces the composition, monitoring methods and working principles of environmental #gamma# dose rate continuous monitoring system at Guangdong Daya Bay Nuclear Power Station. The #gamma# dose rate monitoring status after modification of measurement conditions is introduced too.
The modification of a turbocharged diesel engine to a dual-fuel engine using methane as the supplementary fuel has been carried out. The effect of the gaseous fuel in a turbo-charged diesel engine has been investigated by means of a heat release study and a computer program already developed at Leicester Polytechnic. It is used in order to examine the rate of heat released under any operational condition.
The IGC-30 HPGe detector with MCA 'CANBERRA-10 PLUS' allows to determine surface contamination of areas of any type with a minimum error in radius 8-10 m, at a 'uniform' contamination. A modification of the CANBERRA hardware and software is described allowing determination of both the activity of a possible 'radioactive spot' and the activity of the whole observed surface. (author).
The purpose of this DOE-funded effort is to develop continuous processes for solvent extraction of coal for the production of carbon products. These carbon products include materials used in metals smelting, especially in the aluminum and steel industries, as well as porous carbon structural material referred to as ''carbon foam'' and carbon fibers. During this reporting period, efforts have focused on the facility modifications for continuous hydrotreating, as well as developing improved protocols for producing synthetic pitches.
The mechanism of inactivation of cytochrome P450 2B1 (CYP2B1) by 4-tert-butylphenylacetylene (BPA) has been characterized previously to be caused by the covalent binding of a reactive...Full Text Available
A non-recursive model is proposed and empirically tested with data of opponents of nuclear power. In explaining conventional and unconventional participation the theory of collective action is applied and modified in two respects: the perceived influence on the elimination of collective evils are taken into account; the selective incentives considered are non-material ones. These modifications proved to be valid: the collective good variables and non-material incentives were important determinants for the two forms of participation. Another result was that there is a reciprocal causal relationship between conventional and unconventional participation.
Power devices such as MOSFETSs and IGBTs, include parasitic structures that can give rise to destructive failures such as breakdown and latch-up. To determine a suitable strategy for device radiation hardening, simulation software like MEDICI-2D can be used to model the effects of technological modifications and device parameters that are difficult to measure experimentally. (authors).
Coatings and sensors having both steric and chemical selectivity. Controlled porosity provides the steric selectivity, whereas chemically tailored film properties, using controlled composition or modification by coupling agents, chemical species replacement, or chemical species within pores, provide the chemical selectivity. Single or multiple layers may be provided.
Deposition of CN-based films by a novel version of active screen plasma nitriding, aiming at surface modification of polymers, is reported. The approach relies on the use of pure graphite as the grid material, which was found to act both as an active screen and as a dry source of carbon atoms for the synthesis of thin films consisting mainly of a stoichiometric CN layer with columnar-type structure and dome-like nanostructured morphology.
The Monte Carlo transport codes LAHET and MCNP were used to calculate energy fluence spectra at three neutron therapy facilities. The results compare very favourably with measured data. Kerma spectra and the ratio of ICRU muscle tissue kerma to A-150 kerma, along the carbon to oxygen kerma ratio, were determined. Absorbed dose rate calculations are in reasonable agreement with measured values. Use of these codes to study modifications to existing therapy beams is briefly discussed. (author).
The Advanced Statistical Trajectory Regional Air Pollution (ASTRAP) model simulates long-term transport and deposition of oxides of and nitrogen. t is a potential screening tool for assessing long-term effects on regional visibility from sulfur emission sources. owever, a rigorou...
In order to evacuate the residual power in a nuclear reactor, a thermal valve system is presented for the modification of the heat exchange conditions at the pool exchanger level, which avoids the use of mechanical valves on the pipes. The system involves a vessel containing the exchanger, with openings at the upper end of the vessel and means for feeding the fluid at the lower end, and means for controlling the opening width.
In this comprehensive review of current research on isotopic variations of elements in extraterrestrial materials, the variations were classified in terms of the major process involved in the modification of the isotopic composition of the element concerned. Maximum isotopic variations of each element were retrieved from publications which were available in Tokyo up to December 1985, and are presented in tabular form. (author).
We examined the subcellular localization of ryanodine receptors (RyR) in the cardiac muscle of carp using biochemical, immunohistochemical, and electron microscopic methods and compared it with those of rats and guinea pigs. To achieve this goal, an anti-RyR antibody was newly raised against a synthetic peptide corresponding to an amino acid sequence that was conserved among all sequenced RyRs. Western blot analysis using this antibody detected a single RyR band following the SDS-PAGE of sarcoplasmic reticulum (SR) membranes from carp atrium and ventricle as well as from mammalian hearts and skeletal muscles. The carp heart band had slightly greater mobility than those of mammalian hearts. Although immunohistochemical staining showed evident striations corresponding to the Z lines in longitudinal sections of mammalian hearts, clusters of punctate staining, in contrast, were distributed ubiquitously throughout carp atrium and ventricle. Electron microscopic images ...
In this paper the structural and functional changes of gamma irradiated bovine hemoglobin are presented. Aqueous solutions/1%/of HbO_2 were irradiated in air with doses ranging from 1 to 4 Mrad. Isoelectric focusing indicated change of the charge of irradiated hemoglobin. The isoelectric point of hemoglobin was displaced towards more acid values with increasing doses, up from 1 Mrad. Fingerprint analysis and peptide column chromatography of irradiated hemoglobin demonstrated disturbances increasing with the dose. These changes were confirmed by amino acid analysis which showed that Cys, Met, Trp, His, Pro and Tyr residues were destroyed or modified following irradiation. At doses exceeding 1 Mrad the irradiated solutions of hemoglobin showed a decrease of heme-heme interaction and an increase of affinity for oxygen. Differences observed in oxygen-dissociation curves seem to be correlated with the radiation induced destruction of amino acid residues which are ...
The problem of homochirality is of crucial importance for the origins of Life. While most laboratory studies are focused on the search of physical and chemical sources of handedness in the Universe, they reflect only one aspect of the problem: the origin of homochiral biomolecules. At the same time, any space environments where biomolecules are expected to form and where they have to pass through before the first primitive forms of Life emerge, include strong irradiation or/and high temperatures. This automatically implies the possibility of losing the optical activity, i.e. racemization. The simulation experiments performed by our group deal with the following two aspects of amino acid abiotic chemistry: (1) amino acid pyrolysis associated with their extraterrestrial delivery; and (2) peptide formation from amino acids catalyzed by inorganic oxides. According to our observations, the racemization phenomena are very common in the systems considered, not only under ...
We examined whether or not BMD or bone markers were useful for assessing the risk of vertebral fractures in 248 Japanese men with type 2 diabetes. We analyzed the relationships between bone markers (osteocalcin [OC], bone-specific alkaline phosphatase [BAP], urinary N-terminal cross-linked telopeptide of type-I collagen) or BMD and HbA1c, urinary C-peptide, insulin-like growth factor-I (IGF-I), parathyroid hormone, 1,25(OH)2 vitamin D, and the presence of prevalent vertebral fractures. Multiple regression analysis adjusted for age, body height, weight, duration of diabetes, and serum creatinine showed that serum OC and OC/BAP ratio were correlated negatively with HbA1c (P?P?P?0.05). This association was still significant after additional adjustment for lumbar or femoral neck BMD. Our res...
Aminocyclopropane 1-carboxylic acid (ACC) synthase, a pyridoxal phosphate utilizing enzyme, catalyzes the conversion of S-adenosylmethionine to ACC, the rate limiting step in the biosynthesis of the plant hormone, ethylene. Ethylene, besides being involved in normal plant growth processes, is also produced in response to stress, e.g. wounding, pathogen infection, etc. The authors report the partial purification (400 fold) of ACC synthase from wounded pink tomato pericarp by classical techniques including ammonium sulfate precipitation, ion exchange and phenyl sepharose chromatography. Further purification results in a decrease in specific activity apparently due to the instability of the enzyme and the low levels present in plant tissue. Radiolabeling of a pyridoxal phosphate-utilizing protein in the ACC synthase enriched fraction was achieved. Evidence that this radiolabeled protein is ACC synthase will be presented. Amino acid sequence determination of putative ACC synthase-derived ...
Transcriptional regulation of the galactose-metabolizing genes in Saccharomyces cerevisiae depends on three core proteins: Gal4p, the transcriptional activator that binds to upstream activating DNA sequences (UASGAL); Gal80p, a repressor that binds to the carboxyl terminus of Gal4p and inhibits transcription; and Gal3p, a cytoplasmic transducer that, upon binding galactose and adenosine 5'-triphosphate, relieves Gal80p repression. The current model of induction relies on Gal3p sequestering Gal80p in the cytoplasm. However, the rapid induction of this system implies that there is a missing factor. Our structure of Gal80p in complex with a peptide from the carboxyl-terminal activation domain of Gal4p reveals the existence of a dinucleotide that mediates the interaction between the two. Biochemical and in vivo experiments suggests that nicotinamide adenine dinucleotide phosphate (NADP) plays a key role in the initial induction event.
We describe a method for the analysis of multi-site phosphorylation in serine/threonine (Ser/Thr)-rich protein sequences. Site-specific mutagenesis was used to introduce tryptic cleavage sites in the serine glutamine/threonine glutamine cluster domain (SCD) of the human checkpoint protein kinase (Chk2). The mutant proteins were shown to autophosphorylate on residues that are inducibly phosphorylated when mammalian cells are exposed to ionizing radiation (serine 33/35, serine 516, threonine 68 and threonine 432). Five Ser/Thr clusters within the SCD were flanked by arginine or lysine residues to produce tryptic peptides for nanospray liquid chromatography (nanoLC)/linear quadrupole ion trap Fourier transform ion cyclotron resonance mass spectrometry. Phosphorylation sites were assigned usin...
The structural organization of the genes encoding Bungarus multicinctus protease inhibitor-like proteins (PILPs), PILP-1, PILP-2 and PILP-3, are reported in this study. Unlike PILP-2 and PILP-3, recombinant PILP-1 exhibited inhibitory activity on trypsin. PILP genes and B chain genes shared identical organization with three exons interrupted by two introns in similar positions. On the contrary, intron 1 of these genes had a similar size, a notable variation with the size of intron 2 was observed. It was found that two regions at the second intron of B1 chain and B2 chain genes were absent in that of PILP genes. Noticeably, intronic insertion in the second intron of B chain genes appeared in the promoter region of PILP-1 gene, but not in that of PILP-2 and PILP-3 genes. Comparative analyses of PILP genes and B chain genes showed that the protein-coding regions of the exons are more diverse than introns, except for in the signal peptide domain. These results suggest ...
A radioimmunoassay is described for the molluscan neuropeptide, Phe-Met-Arg-Phe-NH"2(FMRFamide). The antibody used is C-terminal-specific and shows slight but significant (1-2%) cross-reactivity with chicken pancreatic polypeptide (APP). The assay has been used to identify in rat brain extracts a pair of molecules that may represent mammalian counterparts of FMRFamide. Their concentrations were highest in spinal cord and hypothalamus (>10 pmol.g"-_1) and lowest in cerebellum and striatum (<3.5 pmol.g"-_1). The two immunoreactive peptides were separated on CM ion-exchange chromatography where they appeared to be less basic than FMRFamide. On Sephadex G50 gel filtration one eluted in a similar position to FMRFamide and the other slightly earlier suggesting it may be of higher molecular weight. The rat immunoreactive components do not correspond to previously described neuropeptides or hormones, and may be members of a new group of mammalian neuropeptides with ...
Light increased the rate of LHCP synthesis as measured by pulse-labeling with /sup 35/SO/sub 4/ and immunoprecipitation with antibody specific for Euglena LHCP. In addition to the mature LHCP, 26,000 daltons, the LHCP specific antibody immunoprecipitated large amounts of several proteins having molecular weights of approximately 100,000. On immunoblots of immunoprecipitated unlabeled protein, the antibody only detected the mature LHCP suggesting that the high molecular weight proteins are not LHCP aggregates produced during immunoprecipitation. After a 10 min pulse with /sup 35/SO/sub 4/, the 100,000 dalton proteins constituted over 80% of the immunoprecipitated material. In a subsequent chase, the radioactivity in the 100,000 dalton proteins decreased and the radioactivity in the mature LHCP increased suggesting a precursor-product relationship. After a 35 minute chase, the mature LHCP was the major radioactive protein immunoprecipitated. Peptide mapping and in ...
Selecting an appropriate matrix solution is one of the most effective means of increasing the ionization efficiency of phosphopeptides in matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). In this study, we systematically assessed matrix combinations of 2, 6-dihydroxyacetophenone (DHAP) and diammonium hydrogen citrate (DAHC), and demonstrated that the low ratio DHAP/DAHC matrix was more effective in enhancing the ionization of phosphopeptides. Low femtomole level of phosphopeptides from the tryptic digests of ?-casein and ?-casein was readily detected by MALDI-TOF-MS in both positive and negative ion mode without desalination or phosphopeptide enrichment. Compared with the DHB/PA matrix, the optimized DHAP/DAHC matrix yielded superior sample homogeneity and higher phosphopeptide measurement sensitivity, particularly when multiple phosphorylated peptides were assessed. Finally, the DHAP/DAHC matrix was applied to identify ...
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 trypsin of labeled turkey gizzard myosin heavy ...
We performed density functional calculations to examine the effects of solvation, hydrogen bonding, backbone conformation, and the side chain on 15N chemical shielding in proteins. We used N-methylacetamide (NMA) and N-formyl-alanyl-X (with X being one of the 19 naturally occurring amino acids excluding proline) as model systems. In addition, calculations were performed for selected fragments from protein GB3. The conducting polarizable continuum model was employed to include the effect of solvent in the density functional calculations. Our calculations for NMA show that the augmentation of the polarizable continuum model with the explicit water molecules in the first solvation shell has a significant influence on isotropic 15N chemical shift but not as much on the chemical shift anisotropy. The difference in the isotropic chemical shift between the standard ?-sheet and ?-helical conformations ranges from 0.8 to 6.2 ppm depending on the residue type, with the mean of 2.7 ppm. This is ...
The study of chemoattractant receptors on human monocytes had been limited by the lack of a radioligand suitable for use with the small numbers of cells routinely available from human donors. A new synthetic oligopeptide radioligand f(/sup 35/S)Met-leu-phe, with a higher specific radioactivity than was available with the tritiated compound, was used to characterize a chemoattractant receptor on freshly isolated human blood monocytes. These cells bind f(/sup 35/)met-leu-phe with a dissociation constant (KD) of 30.2 +/- 5.6 nM and contain 84,000 +/- 11,300 receptors per cell. f(/sup 35/)met-leu-phe does not bind specifically to blood lymphocytes. The specificity of the oligopeptide receptor on monocytes is indistinguishable from the oligopeptide chemoattractant receptor on human polymorphonuclear leukocytes. Using f(/sup 35/)met-leu-phe, it will now be feasible to study the chemotactic peptide receptor on small numbers of partially purified peripheral blood monocytes ...
The present study investigated the effects of peppermint (Mentha piperita), dill (Anethum graveolens) and basil (Ocimum basilicum) on yogurt formation, proteolysis and inhibition of angiotensin-1 converting enzyme (ACE). Herbal-yogurts had faster rates of pH reduction than plain-yogurt. All herbal-yogurts had higher (p < 0.05) antioxidant activities than plain-yogurt, both at the end of fermentation and throughout the storage period. The o-phthalaldehyde (OPA) peptides in herbal-yogurts increased by 28-36% after 7 days of storage. All herbal-yogurts showed higher anti-ACE activity than plain-yogurt at corresponding storage periods. M. piperita yogurt had highest inhibitory effect on ACE activity throughout the storage period. Peppermint, dill and basil may be used to modify microbial ferme...
The production of molecularly imprinted polymers (MIPs) for the recognition of C-terminal cholecystokinin pentapeptide (CCK-5) in the presence of metal ion is reported. The MIPs were produced under the same molar ratio of template to monomers (acrylamide, N,N'-methylene bisacrylamide) in the presence or absence of nitrilotriacetic acid-nickel (Ni-NTA) complex. Scanning electron microscopy images of MIPs were obtained in an attempt to correlate the adsorption characteristics with polymer's morphology. Subsequently Ni2+ was removed and substituted by other divalent ions such as Mg2+, Fe2+, Zn2+, Co2+ and Cu2+. It was found that polymers containing the metal ion complex with the order Fe-NTA, Ni-NTA and Cu-NTA presented lower dissociation constant values than the rest thus exhibiting stronger guest binding activity. The percentage of theoretical maximum binding sites Bmax was almost the same for these ions, indicating that the ion-template coordination is responsible only for their ...
The ability to feed on vertebrate blood has evolved many times in various arthropod clades. Each time this trait evolves, novel solutions to the problem posed by vertebrate hemostasis are generated. Consequently, saliva of blood-feeding arthropods has proven to be a rich source of antihemostatic molecules. Vasodilators include nitrophorins (nitric oxide storage and transport heme proteins), a variety of peptides that mimic endogenous vasodilatory neuropeptides, and proteins that catabolize or sequester endogenous vasoconstrictors. A variety of platelet aggregation inhibitors antagonize platelet responses to wound-generated signals, including ADP, thrombin, and collagen. Anticoagulants disrupt elements of both the intrinsic and extrinsic pathways. Molecular approaches (termed 'sialomics') to characterize the full inventory of mRNAs transcribed in salivary glands have revealed a surprising level of complexity within a single species. Multiple salivary proteins may be ...
Summary Background Treatment of localised renal cell carcinoma consists of partial or radical nephrectomy. A substantial proportion of patients are at risk for recurrence because no effective adjuvant therapy exists. We investigated the use of an autologous, tumour-derived heat-shock protein (glycoprotein 96)-peptide complex (HSPPC-96; vitespen) as adjuvant treatment in patients at high risk of recurrence after resection of locally advanced renal cell carcinoma. Methods In this open-label trial, patients were randomly assigned to receive either vitespen (n=409) or observation alone (n=409) after nephrectomy. Randomisation was done in a one to one ratio by a computer-generated pseudo-random number generator, with a block size of four, and was stratified by performance score, lymph node stat...
Orientational constraints obtained from solid state NMR experiments on anisotropic samples are used here in molecular dynamics (MD) simulations for determining the structure and dynamics of several different membrane-bound molecules. The new MD technique is based on the inclusion of orientation dependent pseudo-forces in the COSMOS-NMR force field. These forces drive molecular rotations and re-orientations in the simulation, such that the motional time-averages of the tensorial NMR properties approach the experimentally measured parameters. The orientational-constraint-driven MD simulations are universally applicable to all NMR interaction tensors, such as chemical shifts, dipolar couplings and quadrupolar interactions. The strategy does not depend on the initial choice of coordinates, and is in principle suitable for any flexible molecule. To test the method on three systems of increasing complexity, we used as constraints some deuterium quadrupolar couplings from the literature on ...
Orientational constraints obtained from solid state NMR experiments on anisotropic samples are used here in molecular dynamics (MD) simulations for determining the structure and dynamics of several different membrane-bound molecules. The new MD technique is based on the inclusion of orientation dependent pseudo-forces in the COSMOS-NMR force field. These forces drive molecular rotations and re-orientations in the simulation, such that the motional time-averages of the tensorial NMR properties approach the experimentally measured parameters. The orientational-constraint-driven MD simulations are universally applicable to all NMR interaction tensors, such as chemical shifts, dipolar couplings and quadrupolar interactions. The strategy does not depend on the initial choice of coordinates, and is in principle suitable for any flexible molecule. To test the method on three systems of increasing complexity, we used as constraints some deuterium quadrupolar couplings from the literature on ...
Orientational constraints obtained from solid state NMR experiments on anisotropic samples are used here in molecular dynamics (MD) simulations for determining the structure and dynamics of several different membrane-bound molecules. The new MD technique is based on the inclusion of orientation dependent pseudo-forces in the COSMOS-NMR force field. These forces drive molecular rotations and re-orientations in the simulation, such that the motional time-averages of the tensorial NMR properties approach the experimentally measured parameters. The orientational-constraint-driven MD simulations are universally applicable to all NMR interaction tensors, such as chemical shifts, dipolar couplings and quadrupolar interactions. The strategy does not depend on the initial choice of coordinates, and is in principle suitable for any flexible molecule. To test the method on three systems of increasing complexity, we used as constraints some deuterium quadrupolar couplings from the literature on ...
Snake envenomation employs three well integrated strategies: prey immobilization via hypotension, prey immobilization via paralysis, and prey digestion. Purines (adenosine, guanosine and inosine) evidently play a central role in the envenomation strategies of most advanced snakes. Purines constitute the perfect multifunctional toxins, participating simultaneously in all three envenomation strategies. Because they are endogenous regulatory compounds in all vertebrates, it is impossible for any prey organism to develop resistance to them. Purine generation from endogenous precursors in the prey explains the presence of many hitherto unexplained enzyme activities in snake venoms: 5'-nucleotidase, endonucleases (including ribonuclease), phosphodiesterase, ATPase, ADPase, phosphomonoesterase, and NADase. Phospholipases A(2), cytotoxins, myotoxins, and heparinase also participate in purine liberation, in addition to their better known functions. Adenosine contributes to prey immobilization ...
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 physical, chemical ...
Non-destructive testing (NDT) is a dynamic technology and progresses with time. Since the issuance of IAEA-TECDOC-628 in 1991, the technology has experienced numerous changes. Advancements in knowledge about the behaviour of materials have led to changes in the applicable NDT codes, standards and specifications. In addition, over the last ten years, as a result of extensive research and development activities worldwide, new NDT techniques and equipment have been developed which are accepted by engineering community. To accommodate the latest developments, modifications are required to training materials. The present publication is an updated version of IAEA-TECDOC-628. The modifications were made during an Advisory Group Meeting, held in Vienna from 25-29 June 2001. The content of the first edition of IAEA-TECDOC-628 has been revised based on the experience of the experts, as well as comments of the end-user industries. The time allotment for ...
Self-assembled monolayers (SAMs) on various metal, semiconductor or insulator substrates can be easily modified with specific functional groups of interest and have promising applications in surface wetting (hydrophobic/hydrophilic modification), tribology, corrosion protection, sensor electrodes modification, molecular and biomolecular recognition, protein adsorption, cell adhesion, and molecular- or organic-electronic device fabrications. In this paper, we highlight recent progress in the development of SAMs on solid substrates as well as their practical applications, with particular emphasis on the characterization of self-assembled aromatic thiol monolayers with different functional groups on Au(1 1 1) using synchrotron-based photoemission spectroscopy and near-edge X-ray absorption fine structure measurements. The SAM-related molecular orientation, electronic structures, and chemical bonding are presented. Using copper(II) phthalocyanine ...
The LiMnO{sub 2} lamellar oxide, obtained by exchange reaction from its sodium homologue {alpha}-NaMnO{sub 2}, has been used as a positive electrode for lithium batteries. After the first electrochemical cycle, the shape of the potential-composition curve changes and indicates a change in the structure. This modification changes imperceptibly at each cycle and after about 40 cycles, a stationary state is reached. Powder spectra refinement using the Rietvelt method shows a migration of manganese ions from the thin sheets towards the inter-sheet space. After a single cycle, 8% of the manganese ions are already present in the lithium site and this rate reaches 13% after 3 cycles. During long cycling, a redistribution of ions and vacancies inside the cfc oxygenated pile leads to a structure very similar to the LiMn{sub 2}O{sub 4} spinel. This structure evolution is to be compared with the one obtained from the orthorhombic variety of LiMnO{sub 2} but the ...
The present article describes the features of the fully-fired combined cycles and the outline of the plant. Hitachi has optimized fully-fired combined cycle systems by executing a heat recovery type combined cycle. For the fully-fired combined cycles, it is possible to raise plant efficiency through the selection of adequate gas turbine types and cycles. It is possible to apply existing boiler facilities, fuel combustion systems, and stacks. It is possible to execute civil and architectural works on existing plants in-service as well as modification works during routine inspections. The NOx increment by gas turbine unit installations can be reduced by denitration plant modifications. Examples of the fully-fired combined cycles under planning are also introduced. Furthermore, the relational technique and operational characteristics are mentioned, as for combustion characteristics under low oxygen concentration in the wind box, NOx emissions on ...
Here we describe the use of low energy plasma immersion with active screen as a convenient approach for polypropylene (PP) surface modification. Employing a stainless steel cathodic cage coated with carbon in order to prevent the sputtering of iron from the grid and its deposition onto the polymer sample, the physical chemical properties of PP surface could be effectively modified through the plasma-induced incorporation/formation of nitrogen- and oxygen-containing species. The areal densities of these elements depended on the plasma excitation source, as determined by Rutherford backscattering spectrometry (RBS). Newly formed C-O, C-N, and C=O/O=C-O/N-C=O bonds along with C-C linkages from the PP backbone were identified at the near surface region of the specimens by X-ray photoelectron spectroscopy (XPS). The insertion of such polar reactive functionalities was further confirmed by a substantial decrease in the water contact angle upon plasma treatment. Scanning ...
The problem of the optimal dispatch of real thermoelectric generation consists in minimizing the hourly fuel consumption under both network and security constraints. Two recent sequential gradient-restoration algorithms are applied to the solution of this nonlinear programming problem. The first algorithm (Miele et alii) solves a problem with equality, a previous transformation of the inequality constraints. The second algorithm (Levy and Gomez) employs an active set strategy that takes into account, in each gradient or restoration phase, only those inequality constraints which are violated or which are at the limit. Both methods are well suited for the ''compact reduced'' model chosen by the Authors for real power dispatch, leading to the solution of small linear systems in each gradient or restoration phase. More over some modifications of the algorithms have been tested; one of these has lead to marked reductions in ...
We show that a general variant of the Wick theorems can be used to reduce the time ordered products in the Gell-Mann and Low formula for a certain class on non local quantum field theories, including the case where the interaction Lagrangian is defined in terms of twisted products. The only necessary modification is the replacement of the Stueckelberg-Feynman propagator by the general propagator (the 'contractor' of Denk and Schweda) D(y-y';#tau#-#tau#')=(1)/i(#DELTA#_+(y-y')#theta#(#tau#-#tau#')+#DELTA#+(y'-y)#theta#(#tau#'-#tau#)), where the violations of locality and causality are represented by the dependence of #tau#,#tau#' on other points, besides those involved in the contraction. This leads naturally to a diagrammatic expansion of the Gell-Mann and Low formula, in terms of the same diagrams as in the local case, the only necessary modification concerning the Feynman rules. The ordinary local theory is easily recovered as a special case, ...
The Advanced Simulation and Computing (ASC) Distance Computing (DisCom) Wide Area Network (WAN) is a high performance, long distance network environment that is based on the ubiquitous TCP/IP protocol set. However, the Transmission Control Protocol (TCP) and the algorithms that govern its operation were defined almost two decades ago for a network environment vastly different from the DisCom WAN. In this paper we explore and evaluate possible modifications to TCP that purport to improve TCP performance in environments like the DisCom WAN. We also examine a much newer protocol, SCTP (Stream Control Transmission Protocol) that claims to provide reliable network transport while also implementing multi-streaming, multi-homing capabilities that are appealing in the DisCom high performance network environment. We provide performance comparisons and recommendations for continued development that will lead to network communications protocol implementations capable of ...
Nano-wire arrays of Niobium were produced by small angle sputtering on facetted sapphire, using the self shadowing effect of the facets. A wire width of about 80 nm was adjusted, the mean (maximum) wire height was about 20 nm (30 nm), the length can be in the cm range. Meander-film morphologies of 20 nm mean (26 nm maximum) thickness were produced by conventional sputtering onto smooth sapphire substrates at elevated temperatures. The morphology of the wires was investigated with atomic force microscopy (AFM), using contact mode. Meander-films were studied by scanning tunnelling microscopy (STM). Hydrogen loading was performed by instantaneously increasing the hydrogen gas pressure above the solubility limit. Thus, an elongated hydride could be monitored in an about 30 nm thick wire. STM studies on meander-films show the presence of cylindrical hydrides. Local out-of-plane and in-plane expansion can be explained by the formation of hydrides, being coherent with the matrix. This was ...
Recent modifications to the EQ3/6 geochemical modeling software package provide for the use of Pitzer's equations to calculate the activity coefficients of aqueous species and the activity of water. These changes extend the range of solute concentrations over which the codes can be used to dependably calculate equilibria in geochemical systems, and permit the inclusion of ion pairs, complexes, and undissociated acids and bases as explicit component species in the Pitzer model. Comparisons of calculations made by the EQ3NR and EQ6 compuer codes with experimental data confirm that the modifications not only allow the codes to accurately evaluate activity coefficients in concentrated solutions, but also permit prediction of solubility limits of evaporite minerals in brines at 25/sup 0/C and elevated temperatures. Calculations for a few salts can be made at temperatures up to approx. 300/sup 0/C, but the temperature range for most ...
Through DNA methylation, histone modifications, and small regulatory RNAs the epigenome systematically controls gene expression during development, both in utero and throughout life. The epigenome is also a very reactive system; its labile nature allows it to sense and respond to environmental perturbations to ensure survival during fetal growth. This pliability can lead to aberrant epigenetic modifications that persist into later life and induce numerous disease states. Endocrine-disrupting compounds (EDCs) are ubiquitous chemicals that interfere with growth and development. Several EDCs also interfere with epigenetic programming. The investigation of the epigenotoxic effects of bisphenol A (BPA), an EDC used in the production of plastics and resins, has further raised concern over the impact of EDCs on the epigenome. Using the Agouti viable yellow (A(vy)) mouse model, dietary BPA exposure was shown to hypomethylate both the A(vy) and the ...
Ficus religiosa (Pipal) is a long-lived valuable multipurpose forest tree. The tree is exploited because of its religious, ornamental and medicinal value and the regeneration rate in natural habitat is low. An in vitro propagation protocol has been developed from nodal segments obtained from a 45?50-year old tree. The highest bud break frequency (100 %) followed by maximum number of multiple shoots (13.9) as well as length (2.47?cm) were obtained on Woody Plant medium (WPM) supplemented with 1.0?mg/l BAP along with 0.5?mg/l IAA. Two modifications in this medium resulted in enhanced shoot regeneration-one with 200?mg/l glutamine + 150?mg/l ADS (called as MM-1) giving 32.5 shoots per nodal explant while another modification?with 200?mg/l glutamine + 150?mg/l ADS + 100?mg/l phloroglucinol (ca...
A thermal and economic study, carried on by using the first and second law of thermodynamics concepts demonstrated the economic feasibility of the cogeneration system, and proposed modifications to be done in the studied cryogenic plant, a typical T-240 NA MPL3 plant. The thermodynamic analysis showed that the second law efficiency of the processes could be improved, together with a 12% electric energy consumption reduction. Four cogeneration schemes were analyzed with both the first and second laws of thermodynamics and, then, the economic analysis was performed. Rankine, Brayton, Otto and Combined gas-steam basic cycles were used in this analysis.The combined gas-steam cycle was shown to be more economically feasible than others. Thermal and electric loads were well balanced, resulting in a higher second law efficiency. Although the initial investment for the modification was higher, the savings resulted to be higher, turning into a higher ...
Recent data from CREAM seem to confirm early suggestions that primary cosmic ray spectra at few TeV/nucleon are harder than in the 10-100 GeV range. Also, helium and heavier nuclei spectra appear systematically harder than the proton fluxes at corresponding energies. We note here that if the measurements reflect intrinsic features in the interstellar fluxes, appreciable modifications are expected in the sub-TeV range for the secondary yields, such as antiprotons and diffuse gamma-rays. Presently, this effect represents a systematic error in the extraction of astrophysical parameters as well as for background estimates for indirect dark matter searches. We find that the spectral modifications are appreciable above 100 GeV, and can be responsible for ~30% effects for antiprotons at energies close to 1 TeV or for gamma's at energies close to 300 GeV, compared to currently considered predictions based on simple extrapolation of input fluxes from ...
The general usefulness of neutron activation analysis (NAA) for samples containing the platinum group elements (PGE) and Au, either as major or trace constituents, is discussed. Charged particle activation is shown to be a viable or complementary alternative. Proton (6-10 MeV) and alpha particle (9-15 MeV) beams, produced in a tandem Van de Graaff accelerator, have been established to be the most effective choice. By taking advantage of the Coulomb barrier effect and the fact that many charged particle induced reactions have relatively large threshold values, the same instrumental technique can be applied, with minor modifications, to a wide range of materials.
The general usefulness of neutron activation analysis (NAA) for samples containing the platinum group elements and Au, either as major or trace constituents, is discussed. Charged particle activation is shown to be a viable or complementary alternative. Proton (6-10 MeV) and alpha particle (9-15 MeV) beams, produced in a Tandem van de Graaff accelerator, have been established to be the most effective choice. By taking advantage of the Coulomb barrier effect and the fact that many charged particle induced reactions have relatively large threshold values, the same instrumental technique can be applied, with minor modifications, to a wide range of materials.
Eliminating anterior tooth contact is paramount when treating combination syndrome. It is possible to do so through the use of linear occlusion with a non-interceptive arrangement and the bilateral fulcrum of protrusive stability. The presence of mandibular anterior teeth often complicates this procedure. When establishing the horizontal plane of occlusion, clinical circumstances often necessitate modifications; nevertheless, certain principles must be incorporated into the design of the prostheses. Clinical circumstances may dictate altering the approach but these principles must be maintained to eliminate anterior hyperfunction. PMID:15055634
We have performed molecular dynamics simulations of radiation damage in fused silica. In this study, we discuss the role of successive cascade overlap on the saturation and self-healing of oxygen vacancy defects in the amorphous fused silica network. Furthermore, we present findings on the topological changes in fused silica due to repeated energetic recoil atoms. These topological network modifications consistent with experimental Raman spectroscopic observation on neutron and ion irradiated fused silica are indicators of permanent densification that has also been observed experimentally.
Multiwall carbon nanotubes (MWCNTs) were functionalized with a photosensitizer, rosebengal (RB), and folicacid (FA), an anti-cancer drug simultaneously and individually, which was characterized with various analytical instruments like Fourier Transform Iinfrared (FTIR) spectroscopy, UV?Vis spectroscopy, Thermogravimetric analysis (TGA), Photoluminescence (PL) spectroscopy, X-ray photoelectron spectroscopy (XPS), and Transmission electron microscopy (TEM). FTIR spectra confirmed the chemical modification of MWCNT. The chemical functionalization of MWCNT with RB was further supported by UV?Vis and PL spectra.
17-4PH stainless steel was modified by direct current (DC) plasma nitriding and titanium nitride film duplex treatment in this study. The microstructure, wear resistance and corrosion resistance were characterized by X-ray diffraction (XRD), pin-on-disk tribological test and polarization experiment. The results revealed that the DC plasma nitriding pretreatment was in favor of improving properties of titanium nitride film. The corrosion resistance and wear resistance of duplex treatment specimen was more superior to that of only coated titanium nitride film.
17-4PH stainless steel was modified by direct current (DC) plasma nitriding and titanium nitride film duplex treatment in this study. The microstructure, wear resistance and corrosion resistance were characterized by X-ray diffraction (XRD), pin-on-disk tribological test and polarization experiment. The results revealed that the DC plasma nitriding pretreatment was in favor of improving properties of titanium nitride film. The corrosion resistance and wear resistance of duplex treatment specimen was more superior to that of only coated titanium nitride film.
The authors attemps to confirm a modification of the phase-absprotion method applicable to the study of the decay rate of energy stored in the upper level in the active medium of a CO/sub 2/-laser. The essence of the method is described. Relationships are determined which allow one to obtain the unknown parameters of the experimentally measured phase shift. The work exeprimentally shows the possibility of studying vibratioanl relaxation in the active medium of a CO/sub 2/-laser by the phase-absorption method using both ordinary and isotope-substitued molecules.
In-situ sodium activated organo modified bentonite clay was also used for partial replacement of the carbon black (N330). Detailed study with the black filled compound revealed that, with slight modification of the curing package, up to 10 phr of the carbon black replacement is possible. At equivalent loading of 5 and 10 phr of in-situ sodium activated organo modified bentonite clay exhibited better properties in comparison to carbon black filled compound.
Pregnant females and newborn rats were exposed to a gamma irradiation of 150 rads. The stage of gestation at the time of irradiation varied from 14 to 21 days. The newborn rats were irradiated at 0, 1 and 2 days of age. The effect of irradiation of foetus and newborn rats depends on the age of the animal at the time of irradiation. This effect was specially important at the beginning of the foetal life. Neonatal mortality, growth of body weight and adult brain development were investigated. A modification of germ cell radiosensitivity during the period studied, was emphasized.
Using some modification of the standard fermion technique we derive factorized formula for spin operator matrix elements (form-factors) between general eigenstates of the Hamiltonian of quantum Ising chain in a transverse field of finite length. The derivation is based on the approach recently used to derive factorized formula for Z_N-spin operator matrix elements between ground eigenstates of the Hamiltonian of the Z_N-symmetric superintegrable chiral Potts quantum chain. The obtained factorized formulas for the matrix elements of Ising chain coincide with the corresponding expressions obtained by the Separation of Variables Method.
The interaction between a pair of counter-rotating vortices and a lean premixed CH{sub 4}/O{sub 2}/N{sub 2} flame ({Phi} = + 0.55) has been studied by direct numerical simulations using detailed and reduced chemical reaction schemes. Results from the complex chemistry simulation are discussed with respect to earlier experiments and differences in the simulations using detailed and reduces chemistry are investigated. Transient evolutions of the flame surface and the total heat release rate are compared and modifications in the evolution of the local flame structure are displayed. (authors) 22 refs.
Data from the power output of the radioisotope thermoelectric generators aboard the Cassini spacecraft are used to test the conjecture that small deviations observed in terrestrial measurements of the exponential radioactive decay law are correlated with the Earth-Sun distance. No significant deviations from exponential decay are observed over a range of 0.7 - 1.6 A.U. A 90% Cl upper limit of 0.84 x 10^-4 is set on a term in the decay rate of Pu-238 proportional to 1/R^2 and 0.99 x 10^-4 for a term proportional to 1/R.
The major feed-water line break accident is re-analyzed, which is based on Guangdong Daya Bay nuclear power station final safety analysis report, to justify the impacts of the decreasing of auxiliary feed-water flow rate on the safety margin in Daya Bay. The results showed that the accident analysis can meet the demands of acceptance criteria with the auxiliary feed-water flowrate decreasing from 45 m"3/h to 41.8 m"3/h, and enough safety margin is still retained
An advanced video system has been assembled from commercially available equipment to support the real-time neutron radiography facility established jointly by the University of Virginia Department of Nuclear Engineering and Engineering Physics, and the Philip Morris Research Center. A schematic diagram of the equipment used for real-time neutron radiography is presented. To obtain quantitative density measurements with this system, several modifications of both hardware and image processing software were required. After implementation of these changes, the system was capable of determining material densities by measuring the degree of neutron attenuation.
An advanced video system has been assembled from commercially available equipment to support the real-time neutron radiography facility established jointly by the University of Virginia Department of Nuclear Engineering and Engineering Physics, and the Philip Morris Research Center. A schematic diagram of the equipment used for real-time neutron radiography is presented. To obtain quantitative density measurements with this system, several modifications of both hardware and image processing software were required. After implementation of these changes, the system was capable of determining material densities by measuring the degree of neutron attenuation.
The symposium covers papers under different sections namely, (i) Core physics and Fuel management, (ii) Commissioning of facilities and systems, (iii) Operational experience and Human resource development, (iv) Fuel handling, Maintenance management and Surveillance, (v) Instrumentation and Control and Power supply systems, (vi) Analysis, modifications and developments for enhancing operational safety, (vii) Chemistry control and Effluent management, (viii) Radiation and industrial safety and (ix) Steam generators, Turbo-generators and other auxiliaries. Papers relevant to INIS are indexed separately. (author)
The analysis for priority rankings of the recommendations to reduce the total core damage frequency (CDF) of Wolsong nuclear power plant units 2/3/4 was performed in this paper. In order to derive the recommendations, the sensitivity analysis of CDF on which major contributors effect was performed based on the accident quantification results during Level 1 probabilistic safety assessments (PSA). Priorities were ranked in the way that compares the CDF reduction rate with the efforts required to implement those recommendations using risk matrix.
In order to accurately assess the effectiveness of activated charcoal for the removal of radon from flowing air, a literature survey was performed to identify the models and relevant data that were available. It was found that by modifying the mathematical model of equilibrium stage theory used by Strong and Levins, the output rate of an activated charcoal filter exposed to a step function input in the radon rate at time zero with a given carrier gas flow velocity could be predicted. This paper outlines the modifications made to Strong and Levins's model and presents predictions for the filter output from the modified model.
The bibliography contains citations concerning plasma immersion ion implantation (PIII) and equipment. PIII is a new technique to implant plasma ions into materials for surface modification and treatment. Topics include plasma nitriding, semiconductor doping, ion energy distribution, ion dose, pulsed plasma, metal plasma, and defect passivation. References also review applications in semiconductor device and integrated circuit manufacture, silicon material fabrication, aerospace bearings, carbon coatings on metals, and ceramic coatings. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)
Raman scattering measurements of the Esub(g) and Tsub(2g) optical phonons in V"3Si, Nb"3Sn, V"3Ge, Cr"3Si, V"3Pt, and Nb"3Pt are presented and discussed in terms of interaction with interband electronic excitations. Data on superconducting Nb"3Sn is presented and modifications to the phonon spectral function and the spectrum of Raman active interband electronic excitations in the superconducting state are discussed. (orig.).
The ability of the Packard 2000 CA/LL liquid scintillation counter to reduce background count rates relies on pulse shape/duration analysis in which short duration organic scintillation events are discriminated from longer duration non-quenchable background events. A consequence of this is a loss in the counting efficiency. The results of this investigation indicate that much of the lost efficiency can be regained by sharpening the true #beta#"- pulse widths via the use of different scintillant combinations and by certain counter modifications. (author).
Zeolite Y is the active component of most commercial cracking catalysts. Interaction of H[sub 3]PO[sub 4] with extraframework aluminum of ultra-stable zeolite (USY) leads to the formation of different types of aluminum phosphates, while there is no indication of the formation of SAPO zeotype structures. The total acidity of USY slightly decreases upon the H[sub 3]PO[sub 4] treatment, while the maximum in the distribution of acid strength is shifted to milder acidities. Dealumination of the zeolite and creation of POH sites associated with AIPO[sub 4] are responsible for the modifications observed. 37 refs., 8 figs., 3 tabs.
The operation of buildings can be temporarily modified to use much less electricity. These actions may be necessary during regional electricity shortages lasting anywhere from days to months. The electricity conservation measures typically involve a combination of technical modifications, temporary changes in occupant behavior, and greatly increased vigilance. At the same time, attempts to drastically reduce a building's electricity use may have unexpected consequences affecting energy use, the indoor environment, and the performance of building materials and equipment. Electricity shortfalls such as those described in this paper may occur more often as a result of climate change and liberalized electricity markets. (author)
During this reporting period, the work supported under DOE Grant No. FG02-87ER40326.A003 has resulted in one publication, two papers submitted to Phys. Rev. C for publication, and one paper presented at a professional meeting. During this period, modifications were made to the interactive R-Matrix fitting computer program DSIG to include the total radiation widths in the R-Matrix calculation of the cross section. The R-Matrix analyses of n+{sup 90}Zr and n+{sup 208}Pn have already begun.
Nano-materials in which a large fraction of atoms resides within a few atomic layers near the surface can be designed to have novel properties by manipulating their surface parameters. We show that the effective elastic constants of nano-porous/cellular materials can be made to exceed those of the parent materials provided the pore surface elastic parameters satisfy certain conditions. These stiff nano-porous materials herald a radical breakthrough in sandwich-type construction.
Nano-materials in which a large fraction of atoms resides within a few atomic layers near the surface can be designed to have novel properties by manipulating their surface parameters. We show that the effective elastic constants of nano-porous/cellular materials can be made to exceed those of the parent materials provided the pore surface elastic parameters satisfy certain conditions. These stiff nano-porous materials herald a radical breakthrough in sandwich-type construction.
The procedure followed by the Laboratorio de Metrologia Nuclear (LMN) at the IPEN - CNEN/SP, in Sao Paulo, for modifying the NPL-CRC radionuclide sample holder in order to adapt for IPEN vials is presented. For the quality assurance of the results using the IPEN vials, the influence of variation in dimensions and volume of solution has been investigated and suitable correction factors were applied. The solutions used in the present work were "5"1Cr "9"9"mTc "1"5"3Sm, and "2"0"1Tl. (author)
We develop a framework based on microeconomic theory from which the ideal gas like market models can be addressed. A kinetic exchange model based on that framework is proposed and its distributional features have been studied by considering its moments. Next, we derive the moments of the CC model (Eur. Phys. J. B 17 (2000) 167) as well. Some precise solutions are obtained which conform with the solutions obtained earlier. Finally, an output market is introduced with global price determination in the model with some necessary modifications.
Typical receiver processing, targeting always the best achievable bit error rate performance, can result in a waste of resources, especially, when the transmission conditions are such that the best performance is orders of magnitude better than the required. In this work, a processing framework is proposed which allows adjusting the processing requirements to the transmission conditions and the required bit error rate. It applies a-posteriori probability receivers operating over multiple-input multiple-output channels. It is demonstrated that significant complexity savings can be achieved both at the soft, sphere-decoder based detector and the channel decoder with only minor modifications.
Modifications of low-energy theorems for the scattering of longitudinally polarized W and Z bosons in an alternative model of electroweak symmetry breaking are discussed. The symmetry breaking pattern SU(4)/SU(2) leads to light (compared to 1 TeV) pseudo-Goldstone bosons. Their interactions with electroweak gauge bosons are described by chiral (or effective) lagrangian. Tree-level contribution of the pseudo-Goldstone bosons to the scattering amplitudes are computed. Comparison with the Standard Model is given.
Central nervous system (CNS) development, homeostasis, stress responses, and plasticity are all mediated by epigenetic mechanisms that modulate gene expression and promote selective deployment of functional gene networks in response to complex profiles of interoceptive and environmental signals. Thus, not surprisingly, disruptions of these epigenetic processes are implicated in the pathogenesis of a spectrum of neurological and psychiatric diseases. Epigenetic mechanisms involve chromatin remodeling by relatively generic complexes that catalyze DNA methylation and various types of histone modifications. There is increasing evidence that these complexes are directed to their sites of action by long non-protein-coding RNAs (lncRNAs), of which there are tens if not hundreds of thousands speci...
Steam generator tube denting is primarily caused by build-up of corrosion products at the tubesheet and the tube support plates. The mechanism of dent growth and the identification of tubes which should be removed from service have been studied. The practical outcome has been to prevent in-service tube leaks and to avoid unnecessary plugging of large numbers of tubes. A finite element study of tubesheet deformation (of pulled leaking tubes from reactors) was undertaken. Profilometry results for characterizing dents are given. Although several modifications have been made the high resolution profilometry system performance and the results obtained have proved satisfactory. (U.K.).
The effects of {alpha} particle irradiation on a passive film formed on a 304 type stainless steel are studied in situ. The experimental arrangement minimizes the radiolysis effects due to the electrolyte. Under irradiation, a modification of the electronic structure of the oxide layers is revealed by photo-electrochemistry and impedance measurements. The influence of irradiation on the corrosion resistance of the passive film is investigated. Comparing the rest potential and the breakdown potential respectively under and without irradiation, a drop in the passivity range under irradiation is shown. this is interpreted as a decrease in the corrosion resistance. (author).
The effects of #alpha# particle irradiation on a passive film formed on a 304 type stainless steel are studied in situ. The experimental arrangement minimizes the radiolysis effects due to the electrolyte. Under irradiation, a modification of the electronic structure of the oxide layers is revealed by photo-electrochemistry and impedance measurements. The influence of irradiation on the corrosion resistance of the passive film is investigated. Comparing the rest potential and the breakdown potential respectively under and without irradiation, a drop in the passivity range under irradiation is shown. this is interpreted as a decrease in the corrosion resistance. (author).
There is investigated the role of polymer layers on the metal surface of a fine filler in the formation of a PVC system with electrophysical properties. It is shown that a physicochemical polymer modification takes place under the surface active center influence. Thus, the surface layer properties (density and geometrical characteristics) differ from the PVC ones. The correlation between the electrophysical properties of the PVC composite and the surface layer in the range of the fine copper fraction of 0?11.3 vol % at E ? 106 V m?1 and a frequency response of 20?2 ? 105 Hz is determined. An explanation of the investigated relation is presented.
The two model MP Tandem Van de Graaff accelerators at Brookhaven have been used in a four-stage accel-decel configuration to produce highly stripped low energy heavy ions. The performance in this mode of operation has now been substantially improved by modifications of the second accelerator. The inclined field acceleration tube electrodes at the exit of this accelerator were replaced by straight electrodes, the vacuum was improved and the maximum negative terminal potential was increased. Higher intensity beams of heavier highly stripped ions can now be produced at lower energies than before.
This report summarizes the major activities and accomplishments of the Idaho National Engineering and Environmental Laboratory (INEEL) Advanced Radiotherapy Research Program for calendar year 2001. Applications of supportive research and development, as well as technology deployment in the fields of chemistry, radiation physics and dosimetry, and neutron source design and demonstration are described. Contributions in the fields of physics and biophysics include development of advanced patient treatment planning software, feasibility studies of accelerator neutron source technology for Neutron Capture Therapy (NCT), and completion of major modifications to the research reactor at Washington State University to produce an epithermal-neutron beam for NCT research applications.
This report summarizes the major activities and accomplishments of the Idaho National Engineering and Environmental Laboratory (INEEL) Advanced Radiotherapy Research Program for calendar year 2001. Applications of supportive research and development, as well as technology deployment in the fields of chemistry, radiation physics and dosimetry, and neutron source design and demonstration are described. Contributions in the fields of physics and biophysics include development of advanced patient treatment planning software, feasibility studies of accelerator neutron source technology for Neutron Capture Therapy (NCT), and completion of major modifications to the research reactor at Washington State University to produce an epithermal-neutron beam for NCT research applications.
The ability to control the flow of water around the body dictates the performance of marine mammals in the aquatic environment. Morphological specializations of marine mammals afford mechanisms for passive flow control. Aside from the design of the body, which minimizes drag, the morphology of the appendages provides hydrodynamic advantages with respect to drag, lift, thrust, and stall. The flukes of cetaceans and sirenians and flippers of pinnipeds possess geometries with flexibility, which enhance thrust production for high efficiency swimming. The pectoral flippers provide hydrodynamic lift for maneuvering. The design of the flippers is constrained by performance associated with stall. Delay of stall can be accomplished passively by modification of the flipper leading edge. Such a desig...
In this paper a comparison between calculations of severe accidents occurred from WWER-1000 with ASTEC code specified for an event of full unloading with relief valves stuck opened with no hydroaccumulators intervention is presented. The purpose of the analyses provided is to present the relationship between the improvements of the actual version (ASTEC Vl.2 rev. 1) and ASTEC V1.1 p2 like: code modifications, incoming data improvements. Such discrepancies are to be examined. Case by case suggestions for ASTEC improvements are to be provided.
As part of the start up of Los Alamos National Laboratory's new tritium-handling facility, the efficiency of a catalytic oxidation tritium decontamination system was investigated using deuterated methane. The tests were performed during the start up of the facility to confirm the operability of the system before introducing tritium and to provide a baseline for comparison. Techniques and instruments normally used for atmospheric tracer experiments using deuterated methane were applied virtually without modification. The sensitivity of this method allowed preliminary checks at the sub-ppm (v/v) level.
A study is made of plant sensitivity to mutagens during the processing of seeds. An examination is made of problems concerned with modification mutability, the nature of plant restoration following irradiation. Particular attention is given to mutation changes. A presentation is made of several features of mutant changes initially selected by separate indicators. An examination is made of the possible study of mutant indicator genetics. General data on the forms and varieties produced by the mutagenesis method are given. The book is designed for breeding specialists and geneticists engaged in the study of mutagenesis. 439 references, 27 figures, 66 table.
A method for simulating power law noise in clocks and oscillators is presented based on modification of the spectrum of white phase noise, then Fourier transforming to the time domain. Symmetric real matrices are introduced whose traces--the sums of their eigenvalues--are equal to the Allan variances, in overlapping or non-overlapping forms, as well as for the corresponding forms of the modified Allan variance. Diagonalization of these matrices leads to expressions for the probability distributions for observing a variance at an arbitrary value of the sampling or averaging interval $\\tau$, and hence for estimating confidence in the measurements. A number of applications are presented for the common power-law noises.
The high temperature gas-cooled test reactor HTR-10 achieved the first criticality in last December in Institute of Nuclear Energy Technology of Tsinghua University in Beijing. Fuji Electric and Nissho Iwai have a cooperative information exchange agreement on the commercialization of the HTGRs with INET, and held an information exchange meeting in last March in INET. INET has started a study on the modification of the HTR-10 to couple with gas turbine system and a pre-feasibility study on the commercial HTGR under the cooperation with China State Power Company. The experiences and abilities of INET in the field of the HTGR and the aggressive plan for commercialization of the HTGR in China are summarized and discussed. (author)
The 8 papers in the report deal with the following areas: Introduction to diesel particulate emissions, alternative fuels, and the transit industry; Technical problems and policy issues associated with the 1991 bus emissions standards; Reducing transit bus emissions: comparative costs and benefits of methanol, particulate traps, and fuel modification; Effects of applying emissions averaging, trading, and banking to transit buses; Strategic review of heavy-duty engine emission regulations and alternate fuels; Meeting bus emissions standards--a perspective; Economic evaluation of bus maintenance contracting; Objectives for a transit-bus-fleet management data, information, and knowledge exchange.
The current status of research and development in the realm of physics and technology of collective ion acceleration in systems with a virtual cathode (VC) is reviewed. Three major acceleration methods and devices developed on their basis are considered: reflex triodes and their modifications, gas-filled vircators, and vacuum vircators with a Luce diode. Experimental data are outlined and the principal physical models interpreting these data are described. New ion acceleration techniques whose realization involves the production and disappearance of the VC are also discussed. All methods of collective ion acceleration are compared and the possible ways for the further development of this promising scientific field are highlighted. (reviews of topical problems)
Equipment Qualification technology for I and C system on nuclear grade have been approved with accurate and safe for verifying and validation. It contributes to acknowledge of reliability and to review of user approval. Also it did not completely satisfied the requirement of Russia, it can be satisfied by bit of modification on design. It is expected to support the export of safety PLC to nuclear power plant. Proven EQ technology is required on the further markets of nuclear. Therefore, comparison test with foreign country is necessary to support the mutual accreditation of EQ for export of domestic products.
We calculate the electromagnetic form factors of a bound proton. The chiral quark-soliton model provides the quark and antiquark substructure of the proton, which is embedded in nuclear matter. This procedure yields significant modifications of the form factors in the nuclear environment. The sea quarks are almost completely unaffected, and serve to mitigate the valence quark effect. In particular, the ratio of the isoscalar electric to the isovector magnetic form factor decreases by 20% at Q{sup 2}=1 GeV{sup 2} at nuclear density, and we do not see a strong enhancement of the magnetic moment.
Liquid Zone Control (LZC) System is a 'first-of-its-kind' reactivity control device, designed and implemented at TAPP-3 and 4. The system provides zonal and bulk power control. The system consists of fourteen Zone Control Compartments (ZCCs) containing demineralised light water as neutron absorber. Reactivity control is achieved by varying the level of water in the compartments bi-directionally. Six in-core zircaloy assemblies, housing the fourteen ZCCs and an elaborate process system constitute the LZC system. Measurement of water levels in the ZCCs is done using helium bubbler method. Reliability of ZCC water level measurement is of paramount importance. Commissioning and operating the new system trouble free was a challenge, considering the complex nature of the system. While commissioning the system, level measurement of one of the ZCCs (ZCC - 1) was found erratic and inconsistent. Methodologies were developed to identify the problem and investigations revealed leakage of helium ...
The actual cost of constructing the LNG facility was about $589 million, an increase of approximately 258% over the $164 million cost estimate approved by the Federal Power Commission (FPC) in 1977. According to reports submitted by Trunkline LNG, the reasons for the increases included extensive modifications to plant design to ensure safe and reliable construction and greater operating efficiency and compliance with state and federal regulations. Also, extension beyond the original estimated completion date, various labor problems, and general inflation resulted in increased labor and interest costs.
The objective of this work is to improve the process for CO{sub 2} capture by alkanolamine absorption/stripping by developing an alternative solvent, aqueous K{sub 2}CO{sub 3} promoted by piperazine. Progress has been made in this reporting period on three subtasks. A simple thermodynamic model has been developed to represent the CO{sub 2} vapor pressure and speciation of the new solvent. A rate model has been formulated to predict the CO{sub 2} flux with these solutions under absorber conditions. A process and instrumentation diagram and process flow diagram have been prepared for modifications of the existing pilot plant system.
The results and techniques of radiographic study on solidification of iron and steel mould castings are described. The study was made to determine the causes of the mold castings defects. The liquid metal is either labelled in the ladle, or relabelled inside the mould in present time intervals. In the former case, the radioactive phosphorus is segregated in the last-solidifying casting locations, and in the latter, the radioactive phosphorous is distributed along the solid-liquid interface at the time of the next addition in turn. The solidification process parameters may be arrived at by the autoradiograms taken in the pipe-sensitive casting sections. Using these data it is possible to proceed to the proper modifications in the steel casting process.
We entertain the idea that a suitable background of cold (very low momentum) pseudoscalar particles or condensate, may trigger a background that effectively generates Lorentz-invariance violation. This aether-like background induces a Chern-Simons modification of QED. Physics is different in different frames and, in the rest frame of the pseudoscalar background, high momentum photons can decay into pairs. The threshold for such decay depends quadratically on the rest mass of the particles. This mechanism could explain in a natural way why antiprotons are absent in recent cosmic ray measurements. A similar signal could be used as a probe of pseudoscalar condensation in heavy ion collisions.
Measurements of the temperature dependence of the electrical resistivity and correlations observed with T/sub c/ for V_3Si, V_3Ge, and A-15 Nb-Ge show (i) the existence of a universal defect in the A-15 superconductors which is not nonstoichiometry, (ii) a normal state anomaly also strongly influenced by the defects, and (iii) evidence that T/sub c/ and the electron-phonon interactions for transport processes are approx.100 times more sensitive to defect producing sample modifications in the A-15 compounds than in Nb.
During the operation of Daya Bay Nuclear Power Station, some little branches of secondary system were with great vibration and even some of them cracked due to the great vibration that may cause some effect on the safety of the power station. This paper performed analysis and evaluation to the eight systems of Daya Bay Nuclear Power Station based on the vibration test results from the examination of the safety during ten years, and the list of the sensitive piping and suggestion for modification were presented based on the analysis results. (authors)
The adsorption properties of four samples of ..cap alpha..-BN were studied by means of gas chromatography. The particles of ..cap alpha..-BN particles, according to data obtained by electron microscopy, have the shape of thin platelets. A sample of ..cap alpha..-BN prepared from magnesium polyboride was found to be the most nearly homogeneous adsorbent. For a number of n-alkanes, benzene, and alkylbenzenes, data have been obtained on the retention volumes (Henry constants) and the differential heats of adsorption for surface coverages approaching zero. These thermodynamic data on the adsorption showed that ..cap alpha..-BN, like graphitized thermal carbon black, is a nonspecific adsorbent.
Although there is service experience of Alloy 800 as tubing for superheaters in conventional and nuclear (HTR) power stations and in PWR heat exchangers, there is no corresponding service experience in sodium-cooled fast reactor steam generators. However, some limited experimental studies have been made of corrosion behaviour, and of possible structure modifications and effects on mechanical properties which occur during exposure of this material to a high temperature sodium environment, and these are summarised in the paper. It is concluded that further work needs to be done before Alloy 800 can be confidently endorsed for use as tubing in fast reactor steam generators. (author).
Lipase catalyzed esterification of therapeutic drugs to functional self-assembled monolayers (SAMs) on 316L stainless steel (SS) after assembly has been demonstrated. SAMs of 16-mercaptohexadecanoic acid (-COOH SAM) and 11-mercapto-1-undecanol (-OH SAM) were formed on 316L SS, and lipase catalysis was used to attach therapeutic drugs, perphenazine and ibuprofen, respectively, on these SAMs. The reaction was carried out in toluene at 60 degrees C for 5 h using Novozyme-435 as the biocatalyst. The FTIR spectra after surface modification of -OH SAMs showed the presence of the C=O stretching bands at 1745 cm(-1), which was absent in the FTIR spectra of -OH SAMs. Similarly, the FTIR spectra after the reaction of the -COOH SAM with perphenazine showed two peaks in the carbonyl region, a peak at 1764 cm(-1), which is the representative peak for the C=O stretching for esters. The second peak at 1681 cm(-1) is assigned to the C=O stretching of the remaining unreacted ...
Phosphoenolpyruvate carboxykinase (GTP) (PEPCK) specifically utilizes a guanosine or inosine nucleotide as a substrate, yet it does not share extended sequence homology with other GTP-binding proteins, and the molecular basis for its nucleotide specificity is not understood. In an effort to locate the enzyme's nucleotide-binding site, the authors have studied the interaction of cytosolic PEPCK from rat liver with the photoprobe 8-azidoGTP, which fulfills the criteria of a specific photoaffinity label for PEPCK. The photoprobe binds reversibly to the enzyme prior to modification and at low concentrations causes greater than 60% inactivation-GTP provides nearly complete protection against inactivation by 8-azidoGTP, whereas phosphoenolpyruvate and metal ions provide partial protection. In addition, the photoprobe is a substrate for the enzyme and has a K_m similar to that for GTP. However, the extent of covalent modification by ["3"2P]8-azido-GTP ...
Phosphoenolpyruvate carboxykinase (GTP) (PEPCK) specifically utilizes a guanosine or inosine nucleotide as a substrate, yet it does not share extended sequence homology with other GTP-binding proteins, and the molecular basis for its nucleotide specificity is not understood. In an effort to locate the enzyme's nucleotide-binding site, the authors have studied the interaction of cytosolic PEPCK from rat liver with the photoprobe 8-azidoGTP, which fulfills the criteria of a specific photoaffinity label for PEPCK. The photoprobe binds reversibly to the enzyme prior to modification and at low concentrations causes greater than 60% inactivation-GTP provides nearly complete protection against inactivation by 8-azidoGTP, whereas phosphoenolpyruvate and metal ions provide partial protection. In addition, the photoprobe is a substrate for the enzyme and has a K{sub m} similar to that for GTP. However, the extent of covalent modification by ...
Intercrosses of heterozygous pro-opiomelanocortin (POMC) mice result in homozygous null progeny at lower frequencies than expected. Genotyping offspring at pre-, peri-, and postnatal stages revealed that over half of homozygous null mutants die in the early postnatal stages. To investigate the reasons for this early postnatal lethality, we analyzed in detail different parameters in the initial hours after birth. POMC null mutants born to heterozygous dams presented at birth with corticosterone levels no different from wildtype littermates, were euglycemic, and had normal liver glycogen stores. However, already 30 min after birth corticosterone levels dropped by 80% and were undetectable thereafter, while corticosterone levels in wildtype animals increased during postnatal hours. Circulating adrenaline was almost below detection 1h after birth. Blood glucose levels fell sharply in all genotypes within 30 min after birth; however, wildtype and heterozygous pups overcame hypoglycemia ...
Candoxin (PDB #1JGK), a three-finger neurotoxin from Bungarus candidus venom, inhibits post-synaptic neuromuscular and neuronal alpha7nACh-receptors, and induces delayed cell-death throughout the glial population. When applied to cultured human glial cell lines, candoxin (CDX) induced cell death in a concentration (EC(50) approximately 1muM) and time dependent manner. Results of TUNEL-histochemistry further confirm CDX-induced brain (hippocampus, frontal cortex, and temporal regions) damage when administered intracerebroventricularly (i.c.v) in adult mice. In this study, we explored differential gene expression profiles following exposure of human glial (Hs 683) cell lines to CDX at various time intervals using Affymetrix-GeneChips. By means of MAS and GeneSpring analyses, 105 genes whose expression was significantly (P<0.01) altered by at least 3-fold were selected. Results of the genome analysis reveal that the potential role of CDX at molecular level involves the regulation of ...
The present study was designed to assess the radioprotective effects of amifostine on ovarian follicles. Three week-old female mice with or without pretreatment of amifostine were irradiated with 6.42 Gy of #gamma# -ray. Ovaries were collected 0 and 6h after irradiation. DNA fragmentation pattern and expression of genes and activity of proteins related with apoptosis were investigated by means of RT-PCR and Western blot. Proliferation of granulosa cells was reduced and incidence rate of follicular atresia was increased in ovarian follicles in #gamma# -ray irradiated mice compared to those in control or amifostine-treated group. DNA fragmentation was increased in time-dependent manner in granulosa cells of all irradiated groups. However, no difference between amifostine pre-treated group and irradiated groups was found and the expression of p53 as tumor suppressor gene and Bax as one of pro-apoptotic Bcl-2 family was increased in irradiated mice ovaries. PARP as DNA damage sensor was ...
Duchenne and Becker muscular dystrophies are caused by defects of dystrophin, which forms a part of the membrane cytoskeleton of specialized cells such as muscle. It has been previously shown that the dystrophin-associated protein A1 (59-kDa DAP) is actually a heterogeneous group of phosphorylated proteins consisting of an acidic ({alpha}-A1) and a distinct basic ({beta}-A1) component. Partial peptide sequence of the A1 complex purified from rabbit muscle permitted the design of oligonucleotide probes that were used to isolate a cDNA for one human isoform of A1. This cDNA encodes a basic A1 isoform that is distinct from the recently described syntrophins in Torpedo and mouse and is expressed in many tissues with at least five distinct mRNA species of 5.9, 4.8, 4.3, 3.1, and 1.5 kb. A comparison of the human cDNA sequence with the GenBank expressed sequence tag (EST) data base has identified a relative from human skeletal muscle, EST25263, which is probably a human ...
A cytochrome P450 that hydroxylates lauric acid at the 12 position (P450LA omega) was isolated from liver microsomes of clofibrate treated rats. P450LA omega was immunologically distinct from P450s a,b,c,d,e,f,g,h,j,PB1, and PCN1. Polyclonal antibody against P450LA omega was utilized to screen a gt11 cDNA library. A clone (pP450LA omega), was isolated and its sequence determined. The P450LA omega mRNA is a minimum 2387 nts in length and codes for a P450 of Mr.58,222 daltons. This protein shares less than 35% amino acid similarity with P450s b,c,d,e,f,PB1, and PCN1; however, it does contain a hydrophobic amino terminal peptide and a conserved sequence surrounding the Cys residue at position 456, which is similar to other microsomal P450s. P450LA omega is present at high levels in untreated rat kidney and is induced by clofibrate in both kidney and liver. This induction is the result of an accumulation of mRNA through a rapid transcriptional activation of the P450LA ...
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 covalent derivatization of the transport ...
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 derivatization of the transport protein in ...
ATR-X (alpha-thalassemia/mental retardation, X-linked) syndrome is a human congenital disorder that causes severe intellectual disabilities. Mutations in the ATRX gene, which encodes an ATP-dependent chromatin-remodeler, are responsible for the syndrome. Approximately 50% of the missense mutations in affected persons are clustered in a cysteine-rich domain termed ADD (ATRX-DNMT3-DNMT3L, ADD{sub ATRX}), whose function has remained elusive. Here we identify ADD{sub ATRX} as a previously unknown histone H3-binding module, whose binding is promoted by lysine 9 trimethylation (H3K9me3) but inhibited by lysine 4 trimethylation (H3K4me3). The cocrystal structure of ADD{sub ATRX} bound to H3{sub 1-15}K9me3 peptide reveals an atypical composite H3K9me3-binding pocket, which is distinct from the conventional trimethyllysine-binding aromatic cage. Notably, H3K9me3-pocket mutants and ATR-X syndrome mutants are defective in both H3K9me3 binding and localization at ...
The performance of binary geothermal power plants can be improved through the proper choice of a working fluid, and optimization of component designs and operating conditions. This paper reviews the investigations at the Idaho National Engineering Laboratory (INEL) which are examining binary cycle performance improvements: for moderate temperature (350 to 400 F) resources with emphasis on how the improvements may be integrated into design of binary cycles. These investigations are examining performance improvements resulting from the supercritical vaporization of mixed hydrocarbon working fluids and achieving countercurrent integral condensation with these fluids, as well as the modification of the turbine inlet state points to achieve supersaturated turbine vapor expansions. For resources where the brine outlet temperature is restricted, the use of turbine exhaust recuperators is examined. The baseline plant used to determine improvements in plant performance ...
Compared with that of Daya Bay Nuclear Power Plant, the reactor power of QS-II Nuclear Power Plant is decreased and the primary coolant system is changed from three loops to two loops. Thereby the related systems were re-designed, and corresponding tests and engineering validation were carried out. Results of preliminary operation indicate that it is successful. The author describes the design modifications, features and corresponding tests of some systems, reflecting the successful incorporation of engineering and testing, and revealing the capability to develop nuclear power and design the large or medium sized commercial NPP on Self-Reliance in China
Fluoroalkyl end-capped vinyltrimethoxysilane oligomer suffered the sol-gel reaction under alkaline conditions in the presence of titanium oxide nanoparticles in tetrahydrofuran to afford the corresponding fluorinated oligomer/titanium oxide nanocomposites[RF-(VM-SiO2)n-RF/TiO2] in excellent to moderate isolated yields. These fluorinated composites thus obtained were nanometer size-controlled fine particles, and exhibited good dispersibility and stability in traditional organic solvents except for water. These fluorinated nanocomposites were applied to the surface modification of glass to exhibit not only a completely superhydrophobic characteristic (a water contact angle: 180degree) with a non-wetting property against water droplets but also a good oleophobicity imparted by fluoroalkyl seg...
BACKGROUNDLifestyle modifications are successfully employed to treat obese and overweight women with polycystic ovary syndrome (PCOS). The aims of the current pilot study were (i) to compare the efficacy on reproductive functions of a structured exercise training (SET) programme with a diet programme in obese PCOS patients and (ii) to study their clinical, hormonal and metabolic effects to elucidate potentially different mechanisms of action.METHODSForty obese PCOS patients with anovulatory infertility underwent a SET programme (SET group, n = 20) and a hypocaloric hyperproteic diet (diet group, n = 20). Clinical, hormonal and metabolic data were assessed at baseline, and at 12- and 24-week follow-ups. Primary endpoint was cumulative pregnancy rate.RESULTSThe two groups had similar demogra...
We study a two-level atom in interaction with a real massless scalar quantum field in a spacetime with a reflecting boundary. The presence of the boundary modifies the quantum fluctuations of the scalar field, which in turn modifies the radiative properties of atoms. We calculate the rate of change of the mean atomic energy of the atom for both inertial motion and uniform acceleration. It is found that the modifications induced by the presence of a boundary make the spontaneous radiation rate of an excited inertial atom oscillate near the boundary and this oscillatory behavior may offer a possible opportunity for experimental tests for geometrical (boundary) effects in flat spacetime. While for accelerated atoms, the transitions from ground states to excited states are found to be possible even in a vacuum due to changes in the vacuum fluctuations induced by both the presence of the boundary and the acceleration of atoms, and this can be regarded as an actual ...
The performance of five well-known photosynthesis-light equations is compared by presenting a wide range of solutions in the form of dimensionless nomographs for the case where photosynthetically available radiation (PAR) reduces exponentially down the water column and is distributed sinusoidally through the photoperiod. These provide a simple means of calculating daily photosynthesis at any depth (e.g. at a benthic layer), or through a water column, avoiding the need to perform complex integrations. An examination is made of the accuracy of common approximate methods for calculating daily photosynthesis, assuming constant PAR. For optically deep water a modification is proposed to Talling's planimetric solution, to enable daily photosynthesis to be calculated more accurately, yet simply, over the whole range of possible PAR values. The errors induced by approximating the daily PAR distribution as a half-sinusoid are also reported. 13 refs., 9 figs., 5 ...
Abstract Strains of Pseudomonas syringae are effective in controlling postharvest diseases of citrus fruits, and antagonistic activity has been correlated with in vitro production of lipodepsipeptides. Additionally, biocontrol agents can induce a range of defence mechanisms of resistance in citrus tissue that result in a broad spectrum of metabolic modifications, such as systemic acquired resistance, induced systemic resistance and production of reactive oxygen species. The aim of this study was to evaluate the expression of syringomycin (syrB1) and syringopeptin (sypA) synthetase genes from P.syringae pv. syringae biocontrol strains in vitro on different culture media and in vivo on citrus fruits (Citrus sinensis cv. Tarocco) during the interaction with Penicillium digitatum by quantitati...
Here we reported a two-step procedure for preparing a novel polymeric based solid-solid phase change heat storage material. Firstly, a copolymer monomer containing a polyethylene glycol monomethyl ether (MPEG) phase change unit and a vinyl unit was synthesized via the modification of hydrogen group of MPEG. Secondly, by copolymerization of the copolymer monomer and phenyl ethylene, a novel polymeric based solid-solid phase change heat storage material was prepared. The composition, structure and properties of the novel polymeric based solid-solid phase change material were characterized by IR, "1H NMR, DSC, WAXD, and POM, respectively. The results show that the novel polymeric based solid-solid phase change material possesses of excellent crystal properties and high phase change enthalpy.
Novel fluoroalkyl end-capped vinyltrimethoxysilane oligomer/hydroxyapatite (HAp) nanocomposites were prepared by the reaction of calcium nitrate tetrahydrate and phosphoric acid in the presence of the corresponding oligomer. These fluorinated oligomer/HAp composites thus obtained are nanometer size-controlled fine particles (83-173 nm), and were found to exhibit good dispersibility in methanol, ethanol, and isopropyl alcohol. These fluorinated HAp nanocomposites were applied to the surface modification of glass and poly(methyl methacrylate) (PMMA) to exhibit good hydro- and oleophobic characteristics imparted by fluorine on their surface. In addition, the surface structural changes of the modified polyethylene terephtalate and PMMA films treated with these fluorinated nanocomposites before...
Background and aimModification of low-density lipoprotein due to oxidative stress is essential in the development of coronary atherosclerosis. Data of specific carotenoids except b-carotene on cardioprotective effects in humans are limited. Methods and resultsThis study examined the associations between plasma concentrations of specific carotenoids and incidence of acute myocardial infarction. The study included 280 incident cases of acute myocardial infarction and 560 matched controls nested within the Singapore Chinese Health Study, a prospective cohort of 63,257 Chinese men and women aged 45-74 years old enrolled in 1993-1998 in Singapore. Retinol and carotenoids in prediagnostic plasma were quantified using high-performance liquid chromatography. High levels of plasma b-cryptoxanthin a...
We reported in previous papers that both the near-uv and the visible photosensitivities of ferroelectric-phase PLZT (lead lanthanum zirconate titanate) ceramics are increased by as much as four orders of magnitude by ion implantation or a combination of thermal diffusion of Al and ion implantation. New results are presented here on high-energy (1 MeV) implants of Al and Ni and coimplants of Al + Ne and Ni + Ne, and these results are compared with earlier 500 keV implants of Al and Cr and coimplants of Al + Ne and Cr + Ne as surface modification techniques for increasing the visible photosensitivity of PLZT. The important role of grain size in determining optimum contrast and resolution of stored optical information is described in terms of new experimental results.
Asthma, affecting as many as 400 million individuals worldwide, is one of the most prevalent chronic health condition in the United States. With an increasing number of patients with asthma and the frequent inability of conventional lifestyle modification and therapy to effectively control the problem, nutritional and dietary therapies are being sought. This study was undertaken to investigate the efficacy of the purple passion fruit peel (PFP) extract, a novel mixture of bioflavonoids, on asthma symptoms. Patients with asthma were studied in a 4-week randomized, placebo-controlled, double-blind trial with oral administration of PFP extract (150 mg/d) or placebo pills. The effects of PFP extract were evaluated by assessing the clinical symptoms of asthma and spirometry tests. Most clinical...
Nowadays, mixing is one of the most powerful tools for the process and products optimization in chemical process industries. The available technology can help in achieving almost any desired outcomes related to the process-side of the systems. This paper presents a practical methodology to improve existing agitation systems in order to overcome the constraints previously identified in the process. Well succeed real cases using this methodology in a petrochemical plant (Nitriflex S.A.) are presented. (author) 13 refs., 1 figs., 2 tabs.
Using a Markov Chain Monte Carlo optimization algorithm and a computer simulation, I find the passenger ordering which minimizes the time required to board the passengers onto an airplane. The model that I employ assumes that the time that a passenger requires to load his or her luggage is the dominant contribution to the time needed to completely fill the aircraft. The optimal boarding strategy may reduce the time required to board and airplane by over a factor of four and possibly more depending upon the dimensions of the aircraft. I explore some features of the optimal boarding method and discuss practical modifications to the optimal. Finally, I mention some of the benefits that could come from implementing an improved passenger boarding scheme.
A newly developed method to support tissue characterization in routine MR imaging is presented. It represents a compromise between the practical requirements of clinical routine (short measurement time, multisection imaging) and the necessary accuracy of the relaxation parameter evaluation. The sequence employed is a modification of the PHAPS technique and works with two excitation pulses. It allows the simultaneous acquisition of all measurement data for the subsequent T1, T2, and rho evaluations. T1 is determined with a specially designed computation formula based on four signal ratios. A multiexponential T2 analysis is performed with use of 28 echoes. From these parameters, relative proton density can be computed.
We describe the analysis of forward mutations induced in the tetracycline resistance gene of the plasmid pBR322 by directing the reaction of the carcinogen N-acetoxy-N-2-acetylaminofluorene (N-AcO-AAF) to a small restriction fragment (BamHI, SalI) that is located in the proximal part of the antibiotic-resistance gene. Mutant plasmids obtained both in wild type and excision repair deficient (uvrA) bacterial cells are compared. Preliminary data showing the distribution of the -AAF adducts along this restriction fragments are discussed in relation to the observed spectrum of mutations. 20 references, 4 figures.
DBEs (Design Basis Event) of KALIMER-600 (Korea Advanced Liquid Metal Reactor) were analyzed in one dimension by KAERI (Korea Atomic Energy Research Institute). KALIMER-600 is the pool type SFR (Sodium cooled Fast Reactor), thereby the sodium of primary system is prohibited movement to out of a reactor vessel. There are many contacting and including compositions in the sodium hot pool, such as IHX (Intermediate Heat eXchanger), DHX (Decay Heat eXchanger), Pump, UIS (Upper Internal Structure), and core. Moreover, the complex phenomena are occurred in sodium hot pool during steady and transient states. Therefore, the one dimensional analysis is modified to the multi-dimensional analysis through modification of sodium hot pool from one to three dimensions
Abstract: The ability of melatonin as a potent antioxidant was used as a rationale for testing its antiapoptotic ability in normal cells. Recently, melatonin was shown to possess proapoptotic action by increasing reactive oxygen species in certain cancer cells. The modification of radiation-induced apoptosis by melatonin and the expression of apoptosis-associated upstream regulators were studied in normal mice splenocytes and Jurkat T leukemia cells. C57BL/6 mice were exposed to a single whole body X-ray radiation dose of 2 Gy with or without 250 mg/kg melatonin pretreatment. The Jurkat cells were divided into four groups of control, 1 mm melatonin alone, 4 Gy irradiation-only and melatonin pretreatment before irradiation. The highest level of apoptosis in the normal splenic white pulp was...
SR proteins are essential splicing factors whose function is controlled by multi-site phosphorylation of a C-terminal domain rich in arginine-serine repeats (RS domain). The protein kinase SRPK1 has been shown to polyphosphorylate the N-terminal portion of the RS domain (RS1) of the SR protein ASF/SF2, a modification that promotes nuclear entry of this splicing factor and engagement in splicing function. Later, dephosphorylation is required for maturation of the spliceosome and other RNA processing steps. While phosphates are attached to RS1 in a sequential manner by SRPK1, little is known about how they are removed. To investigate factors that control dephosphorylation, we monitored region-specific mapping of phosphorylation sites in ASF/SF2 as a function of the protein phosphatase PP1. W...
Acute {gamma}-irradiation of rats at doses of 100 and 270 Gy stimulates lipid synthesis and changes the lipid composition of liver cell organelles. The content of cholesterol and cholesterol esters in microsomes increased at 100 Gy and decreased at 270 Gy, with total phospholipid content remaining unchanged. The lipid content in mitochondria decreased considerably 1 h after irradiation at 270 Gy. This change was significantly less pronounced 47 h later. Under chronic {gamma}-irradiation (0.129 Gy/day), cholesterol and cardiolipin in mitochondria increased. The changes in lipid content caused by acute irradiation are presumed to be related to activated synthesis of lipids in the liver. The modification of the lipid content of mitochondria observed in chronically irradiated rats may indicate that energy-metabolizing liver cell systems are involved in the adaptation to irradiation.
The site characterization of Yucca Mountain, NV as a potential high level nuclear waste repository includes study of the surficial deposits as a record of the paleoenvironmental history of the Yucca Mountain region. An important aspect of this history is an understanding of the evolution of paleogeography leading to establishment of the present drainage pattern. Establishment of drainage basin evolution is needed before geomorphic response to paleoclimate and tectonics can be assessed, because a major change in drainage basin geometry can predominantly affect the sedimentary record. Because alluvial aquifers are significant to regional hydrology, a major change in surface drainage resulting in buried alluvium could have hydrogeologic significance. In this paper, we report on geologic evidence for a major modification in surface drainage pattern in the Yucca Mountain region, resulting in the probable establishment of the Fortymile Wash drainage basin by latest ...
The technical complexity of intraoperative radiotherapy (IORT) requires modification of the standard physical and dosimetric methods used in external electron beam therapy. At the National Cancer Institute, a number of technical innovations have been integrated into ongoing clinical studies of IORT. These include: (1) an electron beam applicator system that is significantly different from other IORT systems and includes customized squircle applicators; (2) peripheral dose shields; (3) a modified surgical table replacing the standard radiation treatment couch; and (4) routine use of multiple IORT fields that necessitates field matching. The IORT applicator system and related devices and techniques are dosimetrically characterized in detail both for use in the IORT program and in order to illustrate many useful facets of electron dosimetry.
Impacts of gas pipeline rights-of-way (ROWs) through wetlands depend on types of habitat, construction techniques, final elevations, ROW maintenance practices, soil composition, and local climate. In some instances factors unrelated to the presence of the pipeline may have greater impacts on wetland modification than does the pipeline itself. At one site, the required seeding program inhibited natural reestablishment of wetland plants; at another, downstream construction resulted in a major disruption to the adjacent wetland habitat. This paper discusses observation from 13 study sites, each zero to 30 years old, that are located in seven Eastern States.
The influence of the regimes of modification of carbon fibers by an argon ion beam on the change in the angle of their wetting by an epoxy oligomer has been investigated. It has been shown that ion-beam treatment of carbon fibers leads to a considerable decrease in the wetting angles (the difference between the wetting angles for non modified and modified fibers is up to 32.2-38.7). Accordingly, there is also an increase in the value of the equilibrium work of adhesion by 36.2-41.6% in the contact zone. It has been established that ion-beam treatment of carbon fibers by argon ions leads to an increase in the shear strength when microplastics based on them are formed. (authors)
Nanoscale islands of Cu2O have been synthesized on single-crystal SrTiO3 (100) substrates using oxygen plasma-assisted molecular-beam epitaxy (OPA-MBE). Island growth location has been controlled by using an ex-situ Ga+ focused ion beam (FIB) to modify the growth surface in discrete locations prior to island synthesis. Analysis of Cu2O dot growth on unmodified substrate regions revealed an evolution of dot size and array density. Atomic force microscopy studies show that certain FIB substrate modification and MBE growth condition combinations lead to directed self-assembly of islands. Islands initially formed in the FIB-generated surface topography and filled those features before nucleating on neighboring unmodified surface regions.
This paper describes the structure of dynamic neuronal ensembles (DNEs). DNEs represent a new paradigm for learning, based on biological neural networks that use variable structures. We present a computational neural element that demonstrates biological neuron functionality such as neurotransmitter feedback absolute refractory period and multiple output potentials. More specifically, we will develop a network of neural elements that have the ability to dynamically strengthen, weaken, add and remove interconnections. We demonstrate that the DNE is capable of performing dynamic modifications to neuron connections and exhibiting biological neuron functionality. In addition to its applications for learning, DNEs provide an excellent environment for testing and analysis of biological neural systems. An example of habituation and hyper-sensitization in biological systems, using a neural circuit from a snail is presented and discussed. This paper provides an insight into ...
During this reporting period two direct coal liquefaction experiments have been completed and a third is underway. These experiments have produced conversion and selectivity data on samples of Alabama bituminous coal slurried in tetralin and catalyzed using iron-titanium hydride. The experiments address the liquefaction of an agglomerating coal. Conversions of 45 to 55% DAF in 30 min have been recorded at 500/sup 0/F and 520 psia. Equipment modifications were made in an attempt to eliminate the problem of alloy binding in the hydride formation vessel. 4 figs., 4 tabs.
Sandia National Laboratories has developed a family of airfoils specifically designed for use in the equatorial portion of a Vertical-Axis Wind Turbine (VAWT) blade. An airfoil of that family has been incorporated into the rotor blades of the DOE/Sandia 34-m diameter VAWT Test Bed. The airfoil and rotor design process is reviewed. Comparisons with data recently acquired from flow visualization tests and from the DOE/Sandia 34-m diameter VAWT Test Bed illustrate the success that was achieved in the design. The economic optimization model used in the design is described and used to evaluate the effect of modifications to the current Test Bed blade. 1 tab., 11 figs., 13 refs.
The use of dendrimers for preparing chemically sensitive interfaces for detecting volatile organic compounds (VOCs) using surface acoustic wave (SAW) device transducers is described. Specifically, the synthesis of the dendrimers and the means by which they are affixed to SAW devices is discussed, followed by a detailed spectroscopic analysis of the surface-confined dendrimers and a discussion of their interaction with different VOCs. Most of these preliminary experiments focus on dendrimer surface modification using benzoylchloride, which leads to phenyl terminal groups linked to the dendrimer via amide groups. The results of this study lead us to conclude that dendrimers: (1) provide general specificity towards classes of functional groups and are therefore suitable for array-based sensing schemes; (2) are intermediate in structure between monolayers and polymers and exhibit the desirable properties of both; (3) can be straightforwardly attached to the surfaces of ...
Purpose To study the chemical modifications induced upon irradiation of solid human insulin at radiosterilization doses and investigate the influence of the absorbed dose on radiolysis. Materials and Methods Volatile radiolytic products were monitored by gas chromatography coupled with mass spectrometry (GC-MS) and non-volatile products by two different high performance liquid chromatography (HPLC) methods: the formation of higher molecular weight proteins was assessed by size exclusion liquid chromatography whereas assays for related compounds and chemical potency tests were carried out using reverse-phase HPLC-UV. Conformational changes were investigated by measurements of circular dichroism. Results After gamma irradiation at 10?kGy, the recovery of insulin was 96.8%; higher molecular w...
Recently, great interest was paid to new technologies dealing with environmental aspect. Preservation of natural resources such as natural fibers forced the composite industry to search and examine "eco-friendly" components. Studies to find alternative reinforcements and resin systems that are environmentally friendly while providing the same performance as their synthetic counterparts are in continuous progress. The aim of this study is to investigate effect of different treatment process on the data palm fiber (DPF). Raw DPF underwent different surface modification methods such as alkali treatment with concentrations 0.5%, 1%, 1.5%, 2.5% and 5%, and acid treatment with 0.3, 0.9 and 1.6N. All treatments were performed at 100degreeC for 1h. The surface morphology, thermal gravimetry analys...
Guar seed gum, consisting primarily of a high molecular weight galactomannan, is the most cost effective natural thickener, having broad applications in the food, cosmetics, paper, pharmaceutical and petroleum industries. The properties of the polymer can potentially be enhanced by genetic modification. Development of suitable endosperm-specific promoters for use in guar is desirable for metabolic engineering of the seed gum. A ~1.6?kb guar mannan synthase (MS) promoter region has been isolated. The MS promoter sequence was fused with the GUS reporter gene and overexpressed in the heterologous species alfalfa (Medicago sativa). The potential strength and specificity of the MS promoter was compared with those of the constitutive 35S promoter and the seed specific ?-phaseolin promoter. Quant...
The manual enhances and simplifies the work of those architects and engineers whose practice includes the analysis and modification of existing buildings to reduce both fuel consumption and operating costs. A review of the principles of energy use and conservation is given. The manual also provides a step-by-step methodology for assessing and improving the year-round energy performance of buildings, as well as a series of forms, charts, and nomographs designed to serve as day-to-day tools in the energy professional's toolbox. After a cost-benefit analysis is prepared for each conservation opportunity, the owner will be able to implement decisions based on projected energy savings and calculate investment costs, operational changes, and payback periods. Each of these considerations is accorded a detailed treatment.
Alloy 800 has been used by Siemens since 1968 and is now used by KWU for U-tubed steam generators in PWR's. The particular grade of alloy 800 that is used is within the ASTM-Specification B 163, but there have been modifications in composition to improve the corrosion resistance. First the permitted upper limit of carbon was reduced to 0.04% and was then further reduced to 0.03% and a stabilisation ratio of Ti : C >= 12 and Ti : C + N >= 8 was specified. The minimum permitted chromium and nickel levels were increased to 20% and 32% respectively. The maximum permitted levels of other elements or impurities were reduced. At the final fabrication stage peening with glass beads on the outer surface was specified to introduce a compressive stress to depth greater than that allowed for production flaws. An account is given of the behaviour of the alloy in service in four power plants already in operation, and future developments are discussed. (author).
In the Advance Coal Liquefaction Concept Proposal (ACLCP) carbon monoxide (CO) and water have been proposed as the primary reagents in the pretreatment process. The main objective of this project is to develop a methodology for pretreating coal under mild conditions based on a combination of existing processes which have shown great promise in liquefaction, extraction and pyrolysis studies. The aim of this pretreatment process is to partially depolymerise the coal, eliminate oxygen and diminish the propensity for retograde reactions during subsequent liquefaction. The desirable outcome of the CO pretreatment step should be: (1) enhanced liquefaction activity and/or selectivity toward products of higher quality due to chemical modification of the coal structure; (2) cleaner downstream products; (3) overall improvement in operability and process economics.
In the Advance Coal Liquefaction Concept Proposal (ACLCP) carbon monoxide (CO) and water have been proposed as the primary reagents in the pretreatment process. The main objective of this project is to develop a methodology for pretreating coal under mild conditions based on a combination of existing processes which have shown great promise in liquefaction, extraction and pyrolysis studies. The aim of this pretreatment process is to partially depolymerise the coal, eliminate oxygen and diminish the propensity for retograde reactions during subsequent liquefaction. The desirable outcome of the CO pretreatment step should be: (1) enhanced liquefaction activity and/or selectivity toward products of higher quality due to chemical modification of the coal structure; (2) cleaner downstream products; (3) overall improvement in operability and process economics.
In the absence of empirical outdoor thermal comfort studies it has been widely assumed that indoor thermal comfort theory generalises to outdoor settings without modification. Many indoor models were developed to describe thermal discomfort, not stress, therefore their relevance to conditions that vary greatly from neutrality, as many outdoor climatic conditions do, has not been critically validated in the field to date. The thermal comfort of 1018 subjects in outdoor and semi-outdoor locations in subtropical Sydney was investigated by a questionnaire and a comprehensive package of micro-meteorological instruments. The thermal neutrality in terms of the thermal comfort index OUT{sub S}ET* of 26.2 {sup o}C was significantly higher than the indoor SET* counterpart of 24{sup o}C (ASHRAE Trans. 92 (1986) 709). (author)
Plasma erosion craters caused by electrical discharges on the surface of materials are important features of the erosion processes resulting in the degradation of electrodes. In the present work, electrical discharges were produced on a bi-metallic Ni/Cu multilayered surface. By means of dual beam techniques, coupling a focused ion beam (FIB) and a scanning electron microscope (SEM), not only the surface but also the sub-surface structure of the craters were investigated. Using the combination of SEM, FIB and STEM-EDX, a complete three-dimensional investigation of the craters were carried out. The analysis of the microstructure modifications as a function of depth enabled to determine the field of interaction between the plasma and the material. (orig.)