257 research outputs found
A monoclonal antibody to C1q which appears to interact with C1r2C1s2-binding site
AbstractA monoclonal antibody (SB-4) to human C1q was prepared. The equilibrium constant of the antibody for C1q was found to be greater than 1010 M−1. It has been shown that the antibody binds to the A-B chain dimer, probably via the B chain of C1q. Pepsin digestion of C1q at pH 4.5, which fragments the globular regions but leaves the collagenous region intact, allowed the demonstration that the antigenic site is located in the collagenous region of the molecule. The effect of the antibody on haemolytic activity has shown that it is capable of inhibiting the formation of EAC1 cells from EAC1q cells plus C1r and C1s but is incapable of inhibiting the C1 activity of preformed EAC1 cells. This indicates that the binding of the antibody to the collagenous portion of the B chain of C1q probably prevents interaction between C1q and the C1r2-C1s2 complex
A Model of Fermion Masses and Flavor Mixings with Family Symmetry
The family symmetry is proposed to solve flavor problems
about fermion masses and flavor mixings. It's breaking is implemented by some
flavon fields at the high-energy scale. In addition a discrete group is
introduced to generate tiny neutrino masses, which is broken by a real singlet
scalar field at the middle-energy scale. The low-energy effective theory is
elegantly obtained after all of super-heavy fermions are integrated out and
decoupling. All the fermion mass matrices are regularly characterized by four
fundamental matrices and thirteen parameters. The model can perfectly fit and
account for all the current experimental data about the fermion masses and
flavor mixings, in particular, it finely predicts the first generation quark
masses and the values of and in neutrino
physics. All of the results are promising to be tested in the future
experiments.Comment: 14 pages, 1 figure, to make a few of corrections to the old version.
arXiv admin note: substantial text overlap with arXiv:1011.457
A pseudo-spectral method for the Kardar-Parisi-Zhang equation
We discuss a numerical scheme to solve the continuum Kardar-Parisi-Zhang
equation in generic spatial dimensions. It is based on a momentum-space
discretization of the continuum equation and on a pseudo-spectral approximation
of the non-linear term. The method is tested in (1+1)- and (2+1)- dimensions,
where it is shown to reproduce the current most reliable estimates of the
critical exponents based on Restricted Solid-on-Solid simulations. In
particular it allows the computations of various correlation and structure
functions with high degree of numerical accuracy. Some deficiencies which are
common to all previously used finite-difference schemes are pointed out and the
usefulness of the present approach in this respect is discussed.Comment: 12 pages, 13 .eps figures, revetx4. A few equations have been
corrected. Erratum sent to Phys. Rev.
Erratum: Addendum: A cellular chemical probe targeting the chromodomains of Polycomb repressive complex 1 (Nature chemical biology (2016) 12 3 (180-187))
[No abstract available
A cellular chemical probe targeting the chromodomains of Polycomb repressive complex 1
We report the design and characterization of UNC3866, a potent antagonist of the methyllysine (Kme) reading function of the Polycomb CBX and CDY families of chromodomains. Polycomb CBX proteins regulate gene expression by targeting Polycomb repressive complex 1 (PRC1) to sites of H3K27me3 via their chromodomains. UNC3866 binds the chromodomains of CBX4 and CBX7 most potently, with a K d of â ∼1/4100 nM for each, and is 6-to 18-fold selective as compared to seven other CBX and CDY chromodomains while being highly selective over >250 other protein targets. X-ray crystallography revealed that UNC3866's interactions with the CBX chromodomains closely mimic those of the methylated H3 tail. UNC4195, a biotinylated derivative of UNC3866, was used to demonstrate that UNC3866 engages intact PRC1 and that EED incorporation into PRC1 is isoform dependent in PC3 prostate cancer cells. Finally, UNC3866 inhibits PC3 cell proliferation, consistent with the known ability of CBX7 overexpression to confer a growth advantage, whereas UNC4219, a methylated negative control compound, has negligible effects
Accuracy of detecting residual disease after neoadjuvant chemoradiotherapy for esophageal squamous cell carcinoma (preSINO trial): A prospective multicenter diagnostic cohort study
Background: After neoadjuvant chemoradiotherapy (nCRT) for esophageal cancer, high pathologically complete response (pCR) rates are being achieved especially in patients with squamous cell carcinoma (SCC). An active surveillance strategy has been proposed for SCC patients with clinically complete response (cCR) after nCRT. To justify omitting surgical resection, patients with residual disease should be accurately identified. The aim of this study is to assess the accuracy of response evaluations after nCRT based on the preSANO trial, including positron emission tomography with computed tomography (PET-CT), endoscopy with bite-on-bite biopsies and endoscopic ultrasonography (EUS) with fine-needle aspiration (FNA) in patients with potentially curable esophageal SCC. Methods: Operable esophageal SCC patients who are planned to undergo nCRT according to the CROSS regimen and are planned to undergo surgery will be recruited from four Asian centers. Four to 6 weeks after completion of nCRT, patients will undergo a first clinical response evaluation (CRE-1) consisting of endoscopy with bite-on-bite biopsies. In patients without histological evidence of residual tumor (i.e. without positive biopsies), surgery will be postponed another 6 weeks. A second clinical response evaluation (CRE-2) will be performed 10-12 weeks after completion of nCRT, consisting of PET-CT, endoscopy with bite-on-bite biopsies and EUS with FNA. Immediately after CRE-2 all patients without evidence of distant metastases will undergo esophagectomy. Results of CRE-1 and CRE-2 as well as results of the three single diagnostic modalities will be correlated to pathological response in the resection specimen (gold standard) for calculation of sensitivity, specificity, negative predictive value and positive predictive value. Discussion: If the current study shows that major locoregional residual disease (> 10% residual carcinoma or any residual nodal disease) can be accurately (i.e. with sensitivity of 80.5%) detected in patients with esophageal SCC, a prospective trial will be conducted comparing active surveillance with standard esophagectomy in patients with a clinically complete response after nCRT (SINO trial). Trial registration: The preSINO trial has been registered at ClinicalTrials.gov as NCT03937362 (May 3, 2019)
Fish and macroinvertebrate assemblages reveal extensive degradation of the world's rivers
Rivers suffer from multiple stressors acting simultaneously on their biota, but the consequences are poorly quantified at the global scale. We evaluated the biological condition of rivers globally, including the largest proportion of countries from the Global South published to date. We gathered macroinvertebrate- and fish-based assessments from 72,275 and 37,676 sites, respectively, from 64 study regions across six continents and 45 nations. Because assessments were based on differing methods, different systems were consolidated into a 3-class system: Good, Impaired, or Severely Impaired, following common guidelines. The proportion of sites in each class by study area was calculated and each region was assigned a Köppen-Geiger climate type, Human Footprint score (addressing landscape alterations), Human Development Index (HDI) score (addressing social welfare), % rivers with good ambient water quality, % protected freshwater key biodiversity areas; and % of forest area net change rate. We found that 50% of macroinvertebrate sites and 42% of fish sites were in Good condition, whereas 21% and 29% were Severely Impaired, respectively. The poorest biological conditions occurred in Arid and Equatorial climates and the best conditions occurred in Snow climates. Severely Impaired conditions were associated (Pearson correlation coefficient) with higher HDI scores, poorer physico-chemical water quality, and lower proportions of protected freshwater areas. Good biological conditions were associated with good water quality and increased forested areas. It is essential to implement statutory bioassessment programs in Asian, African, and South American countries, and continue them in Oceania, Europe, and North America. There is a need to invest in assessments based on fish, as there is less information globally and fish were strong indicators of degradation. Our study highlights a need to increase the extent and number of protected river catchments, preserve and restore natural forested areas in the catchments, treat wastewater discharges, and improve river connectivity
International Myeloma Working Group risk stratification model for smoldering multiple myeloma (SMM)
Smoldering multiple myeloma (SMM) is an asymptomatic precursor state of multiple myeloma (MM). Recently, MM
was redefined to include biomarkers predicting a high risk of progression from SMM, thus necessitating a redefinition
of SMM and its risk stratification. We assembled a large cohort of SMM patients meeting the revised IMWG criteria to
develop a new risk stratification system. We included 1996 patients, and using stepwise selection and multivariable
analysis, we identified three independent factors predicting progression risk at 2 years: serum M-protein >2 g/dL (HR:
2.1), involved to uninvolved free light-chain ratio >20 (HR: 2.7), and marrow plasma cell infiltration >20% (HR: 2.4). This
translates into 3 categories with increasing 2-year progression risk: 6% for low risk (38%; no risk factors, HR: 1); 18% for
intermediate risk (33%; 1 factor; HR: 3.0), and 44% for high risk (29%; 2–3 factors). Addition of cytogenetic abnormalities
(t(4;14), t(14;16), +1q, and/or del13q) allowed separation into 4 groups (low risk with 0, low intermediate risk with 1,
intermediate risk with 2, and high risk with ≥3 risk factors) with 6, 23, 46, and 63% risk of progression in 2 years,
respectively. The 2/20/20 risk stratification model can be easily implemented to identify high-risk SMM for clinical
research and routine practice and will be widely applicable
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Instrumentation and Measurement Strategy for the NOAA SENEX Aircraft Campaign as Part of the Southeast Atmosphere Study 2013
Natural emissions of ozone-and-aerosol-precursor gases such as isoprene and monoterpenes are high in the southeast of the US. In addition, anthropogenic emissions are significant in the Southeast US and summertime photochemistry is rapid. The NOAA-led SENEX (Southeast Nexus) aircraft campaign was one of the major components of the Southeast Atmosphere Study (SAS) and was focused on studying the interactions between biogenic and anthropogenic emissions to form secondary pollutants. During SENEX, the NOAA WP-3D aircraft conducted 20 research flights between 27 May and 10 July 2013 based out of Smyrna, TN. Here we describe the experimental approach, the science goals and early results of the NOAA SENEX campaign. The aircraft, its capabilities and standard measurements are described. The instrument payload is summarized including detection limits, accuracy, precision and time resolutions for all gas-and-aerosol phase instruments. The inter-comparisons of compounds measured with multiple instruments on the NOAA WP-3D are presented and were all within the stated uncertainties, except two of the three NO2 measurements. The SENEX flights included day- and nighttime flights in the Southeast as well as flights over areas with intense shale gas extraction (Marcellus, Fayetteville and Haynesville shale). We present one example flight on 16 June 2013, which was a daytime flight over the Atlanta region, where several crosswind transects of plumes from the city and nearby point sources, such as power plants, paper mills and landfills, were flown. The area around Atlanta has large biogenic isoprene emissions, which provided an excellent case for studying the interactions between biogenic and anthropogenic emissions. In this example flight, chemistry in and outside the Atlanta plumes was observed for several hours after emission. The analysis of this flight showcases the strategies implemented to answer some of the main SENEX science questions
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