gebhart/patrepeval huggingface dataset:
Magnetic resonance imaging-guided attenuation and scatter corrections in three-dimensional brain positron emission tomography (2003)

Reliable attenuation correction represents an essential component of the long chain of modules required for the reconstruction of artifact-free, quantitative brain positron emission tomography (PET) images. In this work we demonstrate the proof of principle of segmented magnetic resonance imaging (MRI)-guided attenuation and scatter corrections in three-dimensional (3D) brain PET. We have developed a method for attenuation correction based on registered T1-weighted MRI, eliminating the need of an additional transmission (TX) scan. The MR images were realigned to preliminary reconstructions of PET data using an automatic algorithm and then segmented by means of a fuzzy clustering technique which identifies tissues of significantly different density and composition. The voxels belonging to different regions were classified into air, skull, brain tissue and nasal sinuses. These voxels were then assigned theoretical tissue-dependent attenuation coefficients as reported in the ICRU 44 report followed by Gaussian smoothing and addition of a good statistics bed image. The MRI-derived attenuation map was then forward projected to generate attenuation correction factors (ACFs) to be used for correcting the emission (EM) data. The method was evaluated and validated on 10 patient data where TX and MRI brain images were available. Qualitative and quantitative assessment of differences between TX-guided and segmented MRI-guided 3D reconstructions were performed by visual assessment and by estimating parameters of clinical interest. The results indicated a small but noticeable improvement in image quality as a consequence of the reduction of noise propagation from TX into EM data. Considering the difficulties associated with preinjection TX-based attenuation correction and the limitations of current calculated attenuation correction, MRI-based attenuation correction in 3D brain PET would likely be the method of choice for the foreseeable future as a second best approach in a busy nuclear medicine center and could be applied to other functional brain imaging modalities such as SPECT.
Amino Acid Conjugated Sophorolipids:  A New Family of Biologically Active Functionalized Glycolipids (2006)

Sophorolipids (SLs) are extra cellular glycolipids produced by Candida bombicola ATCC 22214 when grown in the presence of glucose and fatty acids. These compounds have a disaccharide head group connected to a long-chain hydroxyl-fatty acid by a glycosidic bond. To explore structure-activity of modified SLs, a new family of amino acid-SL derivatives was prepared. Synthesized analogs consist of amino acids linked by amide bonds formed between their alpha-amino moiety and the carboxyl group of ring-opened SL fatty acids. Their preparation involved the following: (i) hydrolysis of a natural SL mixture with aqueous alkali to give SL free acids, (ii) coupling of free acids to protected amino acids using dicarbodiimide, and (iii) removing amino acid carboxyl protecting groups. These conjugates were evaluated for their antibacterial, anti-HIV, and spermicidal activity. All tested analogs showed antibacterial activity against both gram +ve and gram -ve organisms. Leucine-conjugated SL was most efficient. For example, the minimum inhibitory concentrations (MIC) for Moraxella sp. and E. coli were 0.83 and 1.67 mg/mL, respectively. Among the alkyl esters of amino acid conjugated SLs, the ethyl ester of leucine-SLs was most active. Against Moraxella sp., S. sanguinis, and M. imperiale, MIC values are 7.62 x 10(-4), 2.28 x 10-(3) and 1.67 mg/mL, respectively. All compounds displayed virus-inactivating activity with 50% effective concentrations (EC50) below 200 microg/mL. The EC50 of leucine-SL ethyl ester was 24.1 microg/mL, showing that it is more potent than commercial spermicide nonoxynol-9 (EC50 approximately 65 microg/mL).
Inflammatory mediators in acute pancreatitis (2000)

Inflammatory mediators play a key role in acute pancreatitis and the resultant multiple organ dysfunction syndrome, which is the primary cause of death in this condition. Recent studies have confirmed the critical role played by inflammatory mediators such as TNF-alpha, IL-1beta, IL-6, IL-8, PAF, IL-10, C5a, ICAM-1, and substance P. The systemic effects of acute pancreatitis have many similarities to those of other conditions such as septicaemia, severe burns, and trauma. The delay between the onset of inflammation in the pancreas and the development of the systemic response makes acute pancreatitis an ideal experimental and clinical model with which to study the role of inflammatory mediators and to test novel therapies. Elucidation of the key mediators involved in the pathogenesis of acute pancreatitis will facilitate the development of clinically effective anti-inflammatory therapy.
Load balancing in distributed multi-agent computing systems (2012)

In this paper, a dynamic load-balancing scheme is developed for implementation in an agent-based distributed system. Load balancing is achieved via agent migration from heavily loaded nodes to lightly loaded ones. The credit based concept is used for the dual objective of: (1) the selection of candidate agents for migration, and (2) the selection of destination nodes. This represents an elaboration of previous research work aimed at the selection of agents only. Multiple linear regression is used to achieve our dual objective. A complexity analysis for the proposed system operation is performed, the complete operation is O(n2) where n is the number of agents on the local host. The proposed system is implemented using JADE (Java Agent DEvelopment Framework), the multiple linear regression operation is performed using R Tool. The experimental results show a modified system operation in terms of reduced user’s query response time, by implementing agent load balancing.
S,S-Dimethyl Dithiocarbonate:  A Convenient Reagent for the Synthesis of Symmetrical and Unsymmetrical Ureas (1996)

ADVERTISEMENT RETURN TO ISSUEPREVNoteNEXTS,S-Dimethyl Dithiocarbonate: A Convenient Reagent for the Synthesis of Symmetrical and Unsymmetrical UreasMan-kit Leung, Jun-Liang Lai, King-Hang Lau, Hsiao-hua Yu, and Hsiang-Ju HsiaoView Author Information Department of Chemistry, National Taiwan University, Taipei, Taiwan, Republic of China Cite this: J. Org. Chem. 1996, 61, 12, 4175–4179Publication Date (Web):June 14, 1996Publication History Received28 December 1995Published online14 June 1996Published inissue 1 January 1996https://pubs.acs.org/doi/10.1021/jo9522825https://doi.org/10.1021/jo9522825brief-reportACS PublicationsCopyright © 1996 American Chemical SocietyRequest reuse permissionsArticle Views2746Altmetric-Citations65LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-AlertscloseSupporting Info (1)»Supporting Information Supporting Information SUBJECTS:Alcohols,Amines,Chemical reactions,Reagents,Urea Get e-Alerts
Experimental chemotherapy of typhus Anti-rickettsial action of p -sulphonamidobenzamidine and related compounds (1946)

Abstract The discovery of the pronounced anti-rickettsial activity of p-sulphonamidobenzamidine on experimental typhus infections in mice has led to a search for compounds of enhanced therapeutic action. A large number of compounds have been prepared in development of the sulphonamido-amidine structure, but anti-rickettsial activity has been found to be confined to about a dozen substances intimately related to p-sulphonamidobenzamidine, only one, namely, p-sulphonamidobenzamidoxime, having a very slightly superior therapeutic action. The significance of the discovery of yet another sulphonamide type with pronounced biological activity is discussed.
A majority of Ig H chain cDNA of normal human adult blood lymphocytes resembles cDNA for fetal Ig and natural autoantibodies. (1993)

Certain Ig VH gene segments, with few or no mutations, recur frequently in natural autoantibodies, fetal antibodies, and products of B cell tumors. The goal of this study was to determine whether similar Ig gene segment usage occurs in normal human adult PBL. Extending previous analyses, 105 randomly picked H chain V region clones of representative cDNA libraries from PBL were sequenced. Clones were from: IgM and IgG libraries from one RNA sample of a normal adult; a second IgM library from the same subject 11 mo later; and one IgM library from a second subject. Although some clones had clear evidence of mutation, 48 of 77 IgM clones (62%) shared 99% or more identity with known germline VH segments, and most of these had no mutations in the CDR3 portion of the JH segment. Certain VH gene segments, expressed in autoantibodies and fetal antibodies, occurred at high frequency in these libraries. Fourteen of the clones with 99% identity to known VH segments had CDR3 segments identical to portions of known germline DH gene sequences; two such clones had no N nucleotides at the VHDH or DHJH junctions. IgG-encoding sequences had more mutations than IgM-encoding sequences. JH and DH usage was not random. The circulating B cell population may represent a distinct compartment, with a large proportion of cells similar to those of the fetal and natural autoantibody repertoire. Polyreactive Ig products of these circulating cells may serve a screening function, binding and delivering diverse Ag to secondary lymphoid tissues where more highly selective antibodies are formed to foreign or self-Ag.
Preparation of Superconducting YBCO Thick Films by Spray-Pyrolysis of Organic Acid Salts. (1991)

High Tc superconductive thick films of YBCO system were prepared by the spray-pyrolysis process using toluene solution of metal naphthenates as starting materials. After spraying the mixed solutions of yttrium, barium and copper naphthenates on the yttria-stabilized zirconia (YSZ) substrates and then preheating them at 500°C for 10min, we sintered them at 950-1070°C for 10min. They were finally annealed at 600°C for 10hr in oxygen gas. The specimens which were sintered in the partially melted state above 1010°C showed the Tc, zero at 90K. The critical current density (Jc) of 500A/cm2 at 77K was obtained in thespecimen sintered at 1050°C for 10min.
Isolation and Primary Culture of Murine Alveolar Type II Cells (1996)

Previous attempts to culture mouse alveolar type II (ATII) cells have been hampered by limited purity and cell recovery. We have now obtained culturable ATII cells from female C57BL/6 mice at a purity of 92% +/- 3 (mean +/- SD; n = 20), with viabilities of 96% +/- 2 and total yields of 5.1 +/- 0.7 X 10(6) cells per mouse. Crude lung cell suspensions were prepared by intratracheal instillation of Dispase and agarose followed by mechanical disaggregation of the lungs. Crude cell suspensions were purified by negative selection using a biotinylated-antibody, streptavidin-coated biomagnetic particle system. Cell purities were determined by Pap staining and confirmed ultrastructurally. Purified ATII cells were cultured on fibronectin-coated chamber slides and maintained for up to 5 days in DMEM with 10% fetal bovine serum. Cultures exhibited minimal contamination by Clara cells, mesenchymal cells, or endothelial cells, and the epithelial nature of the cultures was confirmed by positive cytokeratin staining in at least 97% of the cells through day 5. Day 3 cultures demonstrated osmium tetroxide/tannic acid-stained granules consistent with lamellar bodies in 76% +/- 3.6 of the cells. The cultures displayed features distinct from those previously described for adult rat ATII cells, including irregularly-shaped cells and the formation of numerous cytoplasmic projections in direct contact with other cells. These studies indicate that excellent yields of highly purified, culturable ATII cells can be obtained from genetically defined mice. These techniques may provide powerful new models for the study of parenchymal lung disease in vitro.
Pharmacological Tie2 activation in kidney transplantation (2016)

Protection of the endothelial microvasculature via the Tie2 axis in the early transplant setting might hold promise as a therapeutic target.
Human cytomegalovirus uses two distinct pathways to enter retinal pigmented epithelial cells (2007)

Human cytomegalovirus infects multiple cell types, including fibroblasts and epithelial cells. It penetrates fibroblasts by fusion at the cell surface but is endocytosed into epithelial cells. In this report, we demonstrate by electron microscopy that the virus uses two different routes to enter retinal pigmented epithelial cells, depending on the cell type in which the infecting virus was produced. Virus produced in epithelial cells preferentially fuses with the plasma membrane, whereas fibroblast-derived virus mostly enters by receptor-mediated endocytosis. Treatment of epithelial cells with agents that block endosome acidification inhibited infection by virus produced in fibroblasts but had only a modest effect on infection by virus from epithelial cells. Epithelial cell-generated virions had higher intrinsic "fusion-from-without" activity than fibroblast-generated particles, and the two virus preparations triggered different cellular signaling responses, as evidenced by markedly different transcriptional profiles. We propose that the cell type in which a human cytomegalovirus particle is produced likely influences its subsequent spread and its contribution to pathogenesis.
Inhibition of Mannitol Crystallization in Frozen Solutions by Sodium Phosphates and Citrates (2007)

Effects of co-solutes on the physical property of mannitol and sorbitol in frozen solutions and freeze-dried solids were studied as a model of controlling component crystallinity in pharmaceutical formulations. A frozen mannitol solution (500 mM) showed a eutectic crystallization exotherm at -22.8 degrees C, whereas sorbitol remained amorphous in the freeze-concentrated fraction in the thermal scan. Various inorganic salts reduced the eutectic mannitol crystallization peak. Trisodium and tripotassium phosphates or citrates prevented the mannitol crystallization at much lower concentrations than other salts. They also raised transition temperatures of the frozen mannitol and sorbitol solutions (T(g)': glass transition temperature of maximally freeze-concentrated amorphous phase). Crystallization of some salts (e.g., NaCl) induced crystallization of mannitol at above certain salt concentration ratios. Thermal and near-infrared analyses of cooled-melt amorphous sorbitol solids indicated increased intermolecular hydrogen-bonding in the presence of trisodium phosphate. The sodium phosphates and citrates should prevent crystallization of mannitol in frozen solutions and freeze-dried solids by the intense hydrogen-bonding and reduced molecular mobility in the amorphous phase.
Tunneling and Optical Spectroscopy of Semiconductor Nanocrystals (2003)

The use of a combination of tunneling and optical spectroscopy to investigate the size and shape-dependent level structure and single-electron charging phenomena in semiconductor nanocrystals is reviewed. The artificial atom character of semiconductor nanocrystal quantum dots is manifested in both the discrete level structure and in the charging multiplicity of the single-electron tunneling data, revealing s and p atomic-like states. Such states can be directly imaged using scanning tunneling microscopy, providing the extent and symmetry of the envelope wavefunctions. A detailed description of the effect of the tunneling geometry on the single-electron tunneling spectra is presented. Correlation of the optical and tunneling data allows for the assignment of the level spectrum. The generality of this powerful combination is further demonstrated in the study of quantum rods that manifest the transition from zero-dimensional quantum dots to one-dimensional quantum wires.
Large-Scale, One-Step Purification of Murine Interferon-Beta Using a Monoclonal Antibody (1983)

A monoclonal antibody against murine interferon-beta (MuIFN-beta) was prepared using standard methods. Antibodies were immobilized by coupling to Sepharose and used for large-scale purification of poly(I) . poly(C)-induced mouse L cell IFN. Antibodies isolated from the serum of one nude mouse which was transplanted with the anti-MuIFN-beta antibodies producing hybridoma were able to bind at least 7 X 10(7)U MuIFN-beta. In one single antibody affinity chromatography step MuIFN-alpha was separated from MuIFN-beta and a 1000-fold purification of MuIFN-beta was obtained. The purified material had a specific activity of 5 X 10(8)U/mg protein. The recovery from the antibody column was 100%. SDS-PAGE analysis of the purified material revealed the presence of one single protein band with a molecular weight of 33 kD, representing MuIFN-beta.
HIV protease: a novel chemotherapeutic target for AIDS (1991)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTHIV protease: a novel chemotherapeutic target for AIDSJoel R. HuffCite this: J. Med. Chem. 1991, 34, 8, 2305–2314Publication Date (Print):August 1, 1991Publication History Published online1 May 2002Published inissue 1 August 1991https://pubs.acs.org/doi/10.1021/jm00112a001https://doi.org/10.1021/jm00112a001research-articleACS PublicationsRequest reuse permissionsArticle Views1492Altmetric-Citations397LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts
Protein-tyrosine Phosphatase Shp-2 Regulates Cell Spreading, Migration, and Focal Adhesion (1998)

Shp-2, a widely expressed cytoplasmic tyrosine phosphatase with two SH2 domains, is believed to participate in signal relay downstream of growth factor receptors. We show here that this phosphatase also plays an important role in the control of cell spreading, migration, and cytoskeletal architecture. Fibroblast cells lacking a functional Shp-2 were impaired in their ability to spread and migrate on fibronectin compared with wild-type cells. Furthermore, Shp-2 mutant cells displayed an increased number of focal adhesions and condensed F-actin aggregation at the cell periphery, properties reminiscent of focal adhesion kinase (FAK)-deficient cells. This is consistent with our previous observations in vivo that mice homozygous for the Shp-2 mutation died at midgestation with similar phenotype to FAK and fibronectin-deficient embryos, having severe defects in mesodermal patterning, particularly the truncation of posterior structures. Biochemical analysis demonstrated that FAK dephosphorylation was significantly reduced in Shp-2 mutant cells in suspension. Furthermore, regulated association of Src SH2 domain with FAK and paxillin during cell attachment and detachment on fibronectin was disrupted in Shp-2 mutant cells. This report defines a unique role of the Shp-2 tyrosine phosphatase in cell motility, which might guide the design of a new strategy for pharmaceutical interference of tumor metastasis.
Functional study of intracellular P-gp- and MRP1-mediated pumping of free cytosolic pirarubicin into acidic organelles in intrinsic resistant SiHa cells (2003)

We sought to determine the efficiency of the intracellular functional P-gp- and MRP1-mediated pumping of THP into acidic organelles in SiHa cells and etoposide-resistant SiHa/VP16 cells. The expression of both MDR1 and MRP1 genes of SiHa and SiHa/VP16 cells was clearly shown by using RT-PCR. The functional studies of both intracellular functional P-gp- and MRP1-mediated pumping were performed by using THP in a conventional spectrofluorometer, and they demonstrated that SiHa and SiHa/VP16 cells are good models to illustrate the functional role of intracellular P-gp and MRP1 in the transport of free cytosolic drug into acidic organelles. The functional P-gp and MRP1 proteins were identified both on plasma membranes and on intracellular vesicle membranes. Within the limit of experimental error, similar efficiencies in THP transport were observed in the two proteins at both locations in SiHa and SiHa/VP16 cells. The P-gp- and MRP1-mediated pump coefficient (k v a), Michealis-Menten's constant (K V m), and maximal pumping rate (V V max) values of those located on vesicular membranes were 1.87 +/- 0.30 pL x cell-1 x s-1, 1.63 +/- 0.21 microM, and 4.95 +/- 0.45 nM x s-1</sup>, respectively. Drug retention inside acidic organelles (C mon V) of SiHa cells was significantly higher than that of SiHa/VP16 cells, perhaps a consequence of slower movement of recycling endosomes and (or) lysosomes to the cell membrane of SiHa cells, leading to distended organelles and cell death. Our results suggest that intracellular P-gp and MRP1 proteins play an important role in the transport of free drug from cytosol to cytoplasmic acidic organelles.
Enhanced Sensing of Nucleic Acids with Silicon Nanowire Field Effect Transistor Biosensors (2012)

Silicon nanowire (SiNW) field effect transistors (FETs) have emerged as powerful sensors for ultrasensitive, direct electrical readout, and label-free biological/chemical detection. The sensing mechanism of SiNW-FET can be understood in terms of the change in charge density at the SiNW surface after hybridization. So far, there have been limited systematic studies on fundamental factors related to device sensitivity to further make clear the overall effect on sensing sensitivity. Here, we present an analytical result for our triangle cross-section wire for predicting the sensitivity of nanowire surface-charge sensors. It was confirmed through sensing experiments that the back-gated SiNW-FET sensor had the highest percentage current response in the subthreshold regime and the sensor performance could be optimized in low buffer ionic strength and at moderate probe concentration. The optimized SiNW-FET nanosensor revealed ultrahigh sensitivity for rapid and reliable detection of target DNA with a detection limit of 0.1 fM and high specificity for single-nucleotide polymorphism discrimination. In our work, enhanced sensing of biological species by optimization of operating parameters and fundamental understanding for SiNW FET detection limit was obtained.