4,011 research outputs found
Characterization of Metastatic Tumor Formation by the Colony Size Distribution
Knowledge regarding the kinetics of metastatic tumor formation, as related to
the growth of the primary tumor, represents a fundamental issue in cancer
biology. Using an in vivo mammalian model, we show here that one can obtain
useful information from the frequency distribution of the sizes of metastatic
colonies in distant organs after serial sectioning and image reconstruction. To
explain the experimental findings, we constructed a biophysical model based on
the respective growth patterns of the primary tumor and metastases and a
stochastic process of metastatic colony formation. Heterogeneous distributions
of various biological parameters were considered. We found that the elementary
assumption of exponential forms of growth for the primary tumor and metastatic
colonies predicts a linear relation on a log-log plot of a metastatic colony
size distribution, which was consistent with the experimental results.
Furthermore, the slope of the curve signifies the ratio of growth rates of the
primary and the metastases. Non-exponential (Gompertzian and logistic) tumor
growth patterns were also incorporated into the theory to explain possible
deviation from the log-log linear relation. The observed metastasis-free
probability also supported the assumption of a time-dependent Poisson process.
With this approach, we determined the mechanistic parameters governing the
process of metastatogenesis in the lungs for two murine tumor cell lines (KHT
and MCaK). Since biological parameters specified in the model could be obtained
in the laboratory, a workable metastatic "assay" may be established for various
malignancies and in turn contribute in formulating rational treatment regimens
for subclinical metastases.Comment: 14 pages, 6 figure
7-Chloro-4-(2,5-dichlorophenyl)-1-phenyl-1H-thiochromeno[2,3-b]pyridine-2,5(3H,4H)-dione
In the crystal structure of the title compound, C24H14Cl3NO2S, the tetrahydropyridine ring adopts a half-chair conformation and both pendant benzene rings are oriented nearly perpendicular to the thiochromeno[2,3-b]pyridine system
catena-Poly[(chloridozinc)-μ-5-(1-methyl-1H-benzimidazol-2-yl-κN 3)-1,2,3-triazol-1-ido-κ2 N 1:N 3]
In the title complex, [Zn(C10H8N5)Cl]n, the ZnII ion is four-coordinated by one Cl atom and three N atoms from two in situ-generated deprotonated 5-(1-methyl-1H-benzimidazol-2-yl-κN
3)-1,2,3-triazol-1-ide ligands in a slightly distorted tetrahedral geometry. The ZnII ions are bridged by the ligands, forming a helical chain along [001]. C—H⋯N and C—H⋯Cl hydrogen bonds and π–π interactions between the imidazole rings [centroid–centroid distance = 3.4244 (10) Å] assemble the chains into a three-dimensional supramolecular network
Dirac-boson stars
In this paper, we construct \textit{Dirac-boson stars} (DBSs) model composed
of a scalar field and two Dirac fields. The scalar field and both Dirac fields
are in the ground state. We consider the solution families of the DBSs for the
synchronized frequency and the nonsynchronized frequency
cases, respectively. We find several different solutions
when the Dirac mass and scalar field frequency
are taken in some particular ranges. In contrast, no similar
case has been found in previous studies of multistate boson stars. Moreover, we
discuss the characteristics of each type of solution family of the DBSs and
present the relationship between the ADM mass of the DBSs and the
synchronized frequency or the nonsynchronized frequency
. Finally, we calculate the binding energy of the DBSs
and investigate the relationship of with the synchronized frequency
or the nonsynchronized frequency .Comment: 26 pages, 12 figure
Law Article-Enhanced Legal Case Matching: a Causal Learning Approach
Legal case matching, which automatically constructs a model to estimate the
similarities between the source and target cases, has played an essential role
in intelligent legal systems. Semantic text matching models have been applied
to the task where the source and target legal cases are considered as long-form
text documents. These general-purpose matching models make the predictions
solely based on the texts in the legal cases, overlooking the essential role of
the law articles in legal case matching. In the real world, the matching
results (e.g., relevance labels) are dramatically affected by the law articles
because the contents and the judgments of a legal case are radically formed on
the basis of law. From the causal sense, a matching decision is affected by the
mediation effect from the cited law articles by the legal cases, and the direct
effect of the key circumstances (e.g., detailed fact descriptions) in the legal
cases. In light of the observation, this paper proposes a model-agnostic causal
learning framework called Law-Match, under which the legal case matching models
are learned by respecting the corresponding law articles. Given a pair of legal
cases and the related law articles, Law-Match considers the embeddings of the
law articles as instrumental variables (IVs), and the embeddings of legal cases
as treatments. Using IV regression, the treatments can be decomposed into
law-related and law-unrelated parts, respectively reflecting the mediation and
direct effects. These two parts are then combined with different weights to
collectively support the final matching prediction. We show that the framework
is model-agnostic, and a number of legal case matching models can be applied as
the underlying models. Comprehensive experiments show that Law-Match can
outperform state-of-the-art baselines on three public datasets.Comment: 10 pages accepted by SIGIR202
2-Anilino-3-benzoyl-4-(2,5-dichlorophenyl)-7,7-dimethyl-5-oxo-5,6,7,8-tetrahydro-4H-benzo[b]pyran
The title compound, C30H25Cl2NO3, was prepared by the reaction of 3-oxo-N,3-diphenylpropanethioamide, 2,5-dichlorobenzaldehyde and 5,5-dimethyl-1,3-cyclohexanedione (1:1:1) in ethanol. The cyclohexene ring adopts a half-chair conformation. The crystal structure exhibits intramolecular N—H⋯O and C—H⋯O, and intermolecular C—H⋯O interactions
Over-expression of human cytomegalovirus miR-US25-2-3p downregulates eIF4A1 and inhibits HCMV replication
AbstractIt has been reported that human cytomegalovirus (HCMV) miR-US25-2 reduces DNA viral replication including HCMV. However, the mechanism remains unknown. In our study, eukaryotic translation initiation factor 4A1 (eIF4A1) was identified to be a direct target of miR-US25-2-3p. Small interfering RNA (siRNA) and miR-US25-2-3p mediated eIF4A1 knockdown experiments revealed that high level of miR-US25-2-3p in MRC-5 cells decreased HCMV and host genomic DNA synthesis, and inhibited cap-dependent translation and host cell proliferation. However, eIF4A1 up-regulation induced by miR-US25-2-3p inhibitor increased HCMV copy number. Therefore, the over-expression of miR-US25-2-3p and consequent lower expression of eIF4A1 may contribute to the inhibition of HCMV replication
Methodological reporting of randomized controlled trials in major hepato-gastroenterology journals in 2008 and 1998: a comparative study
<p>Abstract</p> <p>Background</p> <p>It was still unclear whether the methodological reporting quality of randomized controlled trials (RCTs) in major hepato-gastroenterology journals improved after the Consolidated Standards of Reporting Trials (CONSORT) Statement was revised in 2001.</p> <p>Methods</p> <p>RCTs in five major hepato-gastroenterology journals published in 1998 or 2008 were retrieved from MEDLINE using a high sensitivity search method and their reporting quality of methodological details were evaluated based on the CONSORT Statement and Cochrane Handbook for Systematic Reviews of interventions. Changes of the methodological reporting quality between 2008 and 1998 were calculated by risk ratios with 95% confidence intervals.</p> <p>Results</p> <p>A total of 107 RCTs published in 2008 and 99 RCTs published in 1998 were found. Compared to those in 1998, the proportion of RCTs that reported sequence generation (RR, 5.70; 95%CI 3.11-10.42), allocation concealment (RR, 4.08; 95%CI 2.25-7.39), sample size calculation (RR, 3.83; 95%CI 2.10-6.98), incomplete outecome data addressed (RR, 1.81; 95%CI, 1.03-3.17), intention-to-treat analyses (RR, 3.04; 95%CI 1.72-5.39) increased in 2008. Blinding and intent-to-treat analysis were reported better in multi-center trials than in single-center trials. The reporting of allocation concealment and blinding were better in industry-sponsored trials than in public-funded trials. Compared with historical studies, the methodological reporting quality improved with time.</p> <p>Conclusion</p> <p>Although the reporting of several important methodological aspects improved in 2008 compared with those published in 1998, which may indicate the researchers had increased awareness of and compliance with the revised CONSORT statement, some items were still reported badly. There is much room for future improvement.</p
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