102 research outputs found
Matriks Jordan Dan Aplikasinya Pada Sistem Linier Waktu Diskrit
Matrix is diagonalizable (similar with matrix diagonal) if and only if the sum of geometric multiplicities of its eigenvalues is n.If we search for an upper triangular form that is nearly diagonal as possible but is still attainable by similarity for every matrix, especially the sum of geometric multiplicities of its eigenvalues is less than n, the result is the Jordan canonical form, which is denoted by , and . In this paper, will be described how to get matrix S(in order to get matrix ) by using generalized eigenvector. In addition, it will also describe the Jordan canonical form and its properties, and some observation and application on discrete time linear system
On the Dielectric “Constant” of Proteins: Smooth Dielectric Function for Macromolecular Modeling and Its Implementation in DelPhi
Implicit methods for modeling protein
electrostatics require dielectric
properties of the system to be known, in particular, the value of
the dielectric constant of protein. While numerous values of the internal
protein dielectric constant were reported in the literature, still
there is no consensus of what the optimal value is. Perhaps this is
due to the fact that the protein dielectric constant is not a “constant”
but is a complex function reflecting the properties of the protein’s
structure and sequence. Here, we report an implementation of a Gaussian-based
approach to deliver the dielectric constant distribution throughout
the protein and surrounding water phase by utilizing the 3D structure
of the corresponding macromolecule. In contrast to previous reports,
we construct a smooth dielectric function throughout the space of
the system to be modeled rather than just constructing a “Gaussian
surface” or smoothing molecule–water boundary. Analysis
on a large set of proteins shows that (a) the average dielectric constant
inside the protein is relatively low, about 6–7, and reaches
a value of about 20–30 at the protein’s surface, and
(b) high average local dielectric constant values are associated with
charged residues while low dielectric constant values are automatically
assigned to the regions occupied by hydrophobic residues. In terms
of energetics, a benchmarking test was carried out against the experimental
p<i>K</i><sub>a</sub>’s of 89 residues in staphylococcal
nuclease (SNase) and showed that it results in a much better RMSD
(= 1.77 p<i>K</i>) than the corresponding calculations done
with a homogeneous high dielectric constant with an optimal value
of 10 (RMSD = 2.43 p<i>K</i>)
The Properties of Asphaltenes and Their Interaction with Amphiphiles
The functional groups on asphaltene surfaces of two kinds of Chinese residue oil were analyzed by X-ray photoelectron spectroscopy (XPS). The ζ potential and electrophoretic mobility of asphaltene solutions and residue solutions were measured through phase analysis light scattering (PALS) technique. The ability to stabilize asphaltenes of two typical ionic amphiphiles, dodecyl benzene sulfonic acid (DBSA) and dodecyl trimethyl ammonium bromide (DTAB), were investigated. Karamay asphaltenes contain large amount of carboxyl and calcium and are negatively charged; whereas Lungu asphaltenes are rich in nickel, vanadium, and pyrrolic structures and are positively charged. DBSA has good ability to stabilize Lungu asphaltenes but has no effect on Karamay asphaltenes. Differently, DTAB has good ability to disperse Karamay asphaltenes but has no obvious effect on Lungu asphaltenes. It is concluded from these results that the charges might derive from the dissociation of metal ions and the deprotonation of acid groups (such as COOH, OH, and SH) or basic groups (such as pyridinic groups) on asphaltene surface. The electric property of asphaltenes plays an important role in the interaction between asphaltenes and amphiphiles. The negatively charged asphaltenes tend to be dispersed by cationic amphiphiles, whereas the positively charged asphaltenes tend to be dispersed by anionic amphiphiles
ABO blood type and risk of hepatocellular carcinoma: a meta-analysis
<p><b>Background</b>: ABO blood type is an invariant factor. There is a link between ABO blood type and some malignancies, such as gastric, pancreatic, and skin cancer. The role of ABO blood type in the pathogenesis of hepatocellular carcinoma (HCC) remains controversial. We performed a meta-analysis to explore the relationship between ABO blood type and risk of HCC.</p> <p><b>Methods</b>: Literature search was conducted among the PubMed, EMBASE, and Cochrane Library databases. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated.</p> <p><b>Results</b>: Seven papers were included. They included 92,847 healthy subjects, 5,463 patients with hepatitis, 294 cirrhotic patients, and 3,322 HCC patients. The proportion of blood type O was significantly lower in HCC patients than healthy subjects (OR = 0.76, 95%CI = 0.66–0.87, P < 0.0001) without any significant heterogeneity (P = 0.55, I<sup>2</sup> = 0%). The proportions of blood types A, B, and <i>AB</i> were not significantly different between HCC patients and healthy subjects. The proportion of ABO blood type was not significantly different between patients with HCC and those with hepatitis or cirrhosis.</p> <p><b>Conclusion</b>: HCC patients might have a lower proportion of blood type O than healthy subjects. Among the patients with chronic liver diseases, ABO blood type might not be associated with the risk of HCC.</p
Additional file 1: of Intracranial lesion as onset symptom in a patient with early undifferentiated connective tissue disease: a case report
Oligoclonal bands are negative and shown below (CSF: cerebrospinal fluid, S: serum, C: positive control). (JPG 1452 kb
The Critical Role of Protein Arginine Methyltransferase <em>prmt8</em> in Zebrafish Embryonic and Neural Development Is Non-Redundant with Its Paralogue <em>prmt1</em>
<div><p>Protein arginine methyltransferase (PRMT) 1 is the most conserved and widely distributed PRMT in eukaryotes. PRMT8 is a vertebrate-restricted paralogue of PRMT1 with an extra N-terminal sequence and brain-specific expression. We use zebrafish (<i>Danio rerio</i>) as a vertebrate model to study PRMT8 function and putative redundancy with PRMT1. The transcripts of zebrafish <i>prmt8</i> were specifically expressed in adult zebrafish brain and ubiquitously expressed from zygotic to early segmentation stage before the neuronal development. Whole-mount <i>in situ</i> hybridization revealed ubiquitous <i>prmt8</i> expression pattern during early embryonic stages, similar to that of <i>prmt1.</i> Knockdown of <i>prmt8</i> with antisense morpholino oligonucleotide phenocopied <i>prmt1-</i>knockdown, with convergence/extension defects at gastrulation. Other abnormalities observed later include short body axis, curled tails, small and malformed brain and eyes. Catalytically inactive <i>prmt8</i> failed to complement the morphants, indicating the importance of methyltransferase activity. Full-length <i>prmt8</i> but not <i>prmt1</i> cRNA can rescue the phenotypic changes. Nevertheless, cRNA encoding Prmt1 fused with the N-terminus of Prmt8 can rescue the <i>prmt8</i> morphants. In contrast, N-terminus- deleted but not full-length <i>prmt8</i> cRNA can rescue the <i>prmt1</i> morphants as efficiently as <i>prmt1</i> cRNA. Abnormal brain morphologies illustrated with brain markers and loss of fluorescent neurons in a transgenic fish upon <i>prmt8</i> knockdown confirm the critical roles of <i>prmt8</i> in neural development. In summery, our study is the first report showing the expression and function of <i>prmt8</i> in early zebrafish embryogenesis. Our results indicate that <i>prmt8</i> may play important roles non-overlapping with <i>prmt1</i> in embryonic and neural development depending on its specific N-terminus.</p> </div
Cell proliferation activity assay in THP-1 cells for PMA.
Cell proliferation activity assay in THP-1 cells for PMA.</p
Top 10 up-regulated expressed mRNAs.
THP-1 monocyte, which can be differentiated into macrophages by PMA, is widely used in researches on pathogen infection and host innate immunity, but reports on the induction methods of PMA are different and lack a unified standard, and the transcriptome characteristics of macrophage compared with THP-1 cells remains unclear. In this research, we examined the differentiation effect of three factors including induction time, cell seeding density and PMA concentration by detecting the positive rate of CD14 expression. The concentration of 80ng/ml of PMA, the induction time of 24h, and the cell seeding density of 5Ă—105 cells/ml, could respectively facilitates a relatively higher CD14 positive rate in THP-1 cells. Under this optimized conditions, the CD14 positive rate of THP-1 cells can reach 66.52%. Transcriptome sequencing showed that after the above induction, the mRNA expression of 3113 genes which were closely related to cell communication, signal transduction, cell response to stimulus, signaling receptor binding and cytokine activity were up-regulated, and the top 10 genes were RGS1, SPP1, GDF15, IL-1B, HAVCR2, SGK1, EGR2, TRAC, IL-8 and EBI3. While the mRNA expression of 2772 genes which were associated with cell cycle process, DNA binding and replication and cell division, were down-regulated, and the top genes were SERPINB10, TRGC2, SERPINB2, TRGC1, MS4A3, MS4A4E, TRGJP1, MS4A6A, TRGJP2, MS4A4A. This research optimized the induction method on THP-1 cell differentiation from three aspects and delineated the transcriptomic profile of PMA-induced THP-1 cells, laying a foundation for the construction method of cell model and for the functional study of macrophage.</div
Top 10 down-regulated expressed mRNAs.
THP-1 monocyte, which can be differentiated into macrophages by PMA, is widely used in researches on pathogen infection and host innate immunity, but reports on the induction methods of PMA are different and lack a unified standard, and the transcriptome characteristics of macrophage compared with THP-1 cells remains unclear. In this research, we examined the differentiation effect of three factors including induction time, cell seeding density and PMA concentration by detecting the positive rate of CD14 expression. The concentration of 80ng/ml of PMA, the induction time of 24h, and the cell seeding density of 5Ă—105 cells/ml, could respectively facilitates a relatively higher CD14 positive rate in THP-1 cells. Under this optimized conditions, the CD14 positive rate of THP-1 cells can reach 66.52%. Transcriptome sequencing showed that after the above induction, the mRNA expression of 3113 genes which were closely related to cell communication, signal transduction, cell response to stimulus, signaling receptor binding and cytokine activity were up-regulated, and the top 10 genes were RGS1, SPP1, GDF15, IL-1B, HAVCR2, SGK1, EGR2, TRAC, IL-8 and EBI3. While the mRNA expression of 2772 genes which were associated with cell cycle process, DNA binding and replication and cell division, were down-regulated, and the top genes were SERPINB10, TRGC2, SERPINB2, TRGC1, MS4A3, MS4A4E, TRGJP1, MS4A6A, TRGJP2, MS4A4A. This research optimized the induction method on THP-1 cell differentiation from three aspects and delineated the transcriptomic profile of PMA-induced THP-1 cells, laying a foundation for the construction method of cell model and for the functional study of macrophage.</div
Expression analysis of <i>prmt8</i> RNA in zebrafish adult tissues and embryos.
<p>(A) Expression of <i>prmt8</i> in different adult tissues was analyzed by RT-PCR. EF indicates the RT-PCR product of elongation factor. (B: brain; SP: spleen; G: gill; O: ovary; H: heart; SB: swim bladder; S: skin; E: eye; M: muscle; T: testis) (B) RT-PCR of <i>prmt8</i> RNA prepared from 0.25 hpf to 72 hpf embryos. (C) The spatial and temporal expression of <i>prmt8</i> RNA from 1 cell to 96 hpf by WISH in zebrafish embryonic development. (m: midbrain; Mhb: mid-hindbrain boundary; som: somites).</p
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