172 research outputs found
corrections to holographic heavy meson dissociation
In this paper, we study the corrections to the spectral functions of
heavy mesons in Gauss-Bonnet gravity. We discuss the effect of Gauss-Bonnet
parameter on the 1S states and 2S states of charmonium and
bottomonium. It is found that reduces the height and increases
the width of the 1S states peak. The 2S states of charmonium and bottomonium
dissociate gradually as increasing . It is obvious that
enhances the dissociation of charmonium and bottomonium.Comment: 13 pages, 4 figure
An Explorative Study on Document Type Assignment of Review Articles in Web of Science, Scopus and Journals' Website
Accurately assigning the document type of review articles in citation index
databases like Web of Science(WoS) and Scopus is important. This study aims to
investigate the document type assignation of review articles in web of Science,
Scopus and Journals' website in a large scale. 27,616 papers from 160 journals
from 10 review journal series indexed in SCI are analyzed. The document types
of these papers labeled on journals' website, and assigned by WoS and Scopus
are retrieved and compared to determine the assigning accuracy and identify the
possible reasons of wrongly assigning. For the document type labeled on the
website, we further differentiate them into explicit review and implicit review
based on whether the website directly indicating it is review or not. We find
that WoS and Scopus performed similarly, with an average precision of about 99%
and recall of about 80%. However, there were some differences between WoS and
Scopus across different journal series and within the same journal series. The
assigning accuracy of WoS and Scopus for implicit reviews dropped
significantly. This study provides a reference for the accuracy of document
type assigning of review articles in WoS and Scopus, and the identified pattern
for assigning implicit reviews may be helpful to better labeling on website,
WoS and Scopus
The effects of three different grinding methods in DNA extraction of cowpea (Vigna unguiculata L. Walp)
Rapid DNA extraction is a prerequisite for molecular studies. Generally, plant tissue is ground in liquid nitrogen to isolate DNA; but, liquid nitrogen is dangerous and volatile. Besides, liquid nitrogen is not always available in many developing countries. To investigate if high quality DNA could be obtained for downstream PCR analysis without liquid nitrogen, the cowpea DNA was extracted by Hexadecyl trimethyl ammonium bromide cetyl trimethylammonium bromide (CTAB) method and sodium dodecyl sulphate (SDS) method, respectively, each with three different grinding methods, including ground in liquid nitrogen, in preheated mortar and in non-preheated mortar. The DNA was compared according to their yield, purity, integrity and functionality. The results showed that high quality DNA could be obtained by three grinding methods both in CTAB method and SDS method. Without liquid nitrogen, grinding plant tissue in preheated or non-preheated mortar with extraction buffer to extract DNA is feasible.Keywords: Cowpea (Vigna unguiculata), grinding method, liquid nitrogen, DNA extractionAfrican Journal of Biotechnology Vol. 12(16), pp. 1946-195
A Biodegradable Polyethylenimine-Based Vector Modified by Trifunctional Peptide R18 for Enhancing Gene Transfection Efficiency In Vivo
Lack of capacity to cross the nucleus membrane seems to be one of the main
reasons for the lower transfection efficiency of gene vectors observed in vivo
study than in vitro. To solve this problem, a new non-viral gene vector was
designed. First, a degradable polyethylenimine (PEI) derivate was synthesized
by crosslinking low-molecular-weight (LMW) PEI with N-octyl-N-quaternary
chitosan (OTMCS), and then adopting a designed trifunctional peptide (RGDC-
TAT-NLS) with good tumor targeting, cell uptake and nucleus transport
capabilities to modify OTMCS-PEI. The new gene vector was termed as OTMCS-
PEI-R18 and characterized in terms of its chemical structure and biophysical
parameters. Gene transfection efficiency and nucleus transport mechanism of
this vector were also evaluated. The polymer showed controlled degradation and
remarkable buffer capabilities with the particle size around 100–300 nm and
the zeta potential ranged from 5 mV to 40 mV. Agraose gel electrophoresis
showed that OTMCS-PEI-R18 could effectively condensed plasmid DNA at a ratio
of 1.0. Besides, the polymer was stable in the presence of sodium heparin and
could resist digestion by DNase I at a concentration of 63U DNase I/DNA.
OTMCS-PEI-R18 also showed much lower cytotoxicity and better transfection
rates compared to polymers OTMCS-PEI-R13, OTMCS-PEI and PEI 25 KDa in vitro
and in vivo. Furthermore, OTMCS-PEI-R18/DNA complexes could accumulate in the
nucleus well soon and not rely on mitosis absolutely due to the newly
incorporated ligand peptide NLS with the specific nuclear delivery pathway
indicating that the gene delivery system OTMCS-PEI-R18 could reinforce gene
transfection efficiency in vivo
CcRR5 interacts with CcRR14 and CcSnRK2s to regulate the root development in citrus
Response regulator (RR) is an important component of the cytokinin (CK) signal transduction system associated with root development and stress resistance in model plants. However, the function of RR gene and the molecular mechanism on regulating the root development in woody plants such as citrus remain unclear. Here, we demonstrate that CcRR5, a member of the type A RR, regulates the morphogenesis of root through interacting with CcRR14 and CcSnRK2s in citrus. CcRR5 is mainly expressed in root tips and young leaves. The activity of CcRR5 promoter triggered by CcRR14 was proved with transient expression assay. Seven SnRK2 family members with highly conserved domains were identified in citrus. Among them, CcSnRK2.3, CcSnRK2.6, CcSnRK2.7, and CcSnRK2.8 can interact with CcRR5 and CcRR14. Phenotypic analysis of CcRR5 overexpressed transgenic citrus plants indicated that the transcription level of CcRR5 was associated with root length and lateral root numbers. This was also correlated to the expression of root-related genes and thus confirmed that CcRR5 is involved in the root development. Taken together, the results of this study indicate that CcRR5 is a positive regulator of root growth and CcRR14 directly regulates the expression of CcRR5. Both CcRR5 and CcRR14 can interact with CcSnRK2s
Rapid Body-Wide Transcriptomic Turnover During Rhesus Macaque Perinatal Development
An hourglass cup-shape pattern of regulation at the molecular level was detected during the development of the primate brain. Specifically, a peak of temporally differentially expressed genes around the time of birth has been observed in the human brain. However, to what extend this peak of regulation exists among species has not been investigated in great detail. Here, by integrating multiple large-scale transcriptome data from rhesus macaques, we confirmed that a similar differential expression peak exists during the development of the macaque brain. We also found that a similar peak exists during the development of other organs, such as liver, testis, kidney and heart. Furthermore, we found that distinct pathways are regulated in the peak period of those organs. Our results highlight the importance of co-evolution of diverse organs during critical periods of perinatal development in primates
Identification of immunodiagnostic blood biomarkers associated with spinal cord injury severity
Blood always shows some immune changes after spinal cord injury (SCI), and detection of such changes in blood may be helpful for diagnosis and treatment of SCI. However, studies to date on blood immune changes after SCI in humans are not comprehensive. Therefore, to obtain the characteristics of blood immune changes and immunodiagnostic blood biomarkers of SCI and its different grades, a human blood transcriptome sequencing dataset was downloaded and analyzed to obtain differentially expressed immune-related genes (DEIGs), related functions and signaling pathways related to SCI and its various grades. Characteristic biomarkers of SCI and its different grades were identified by using weighted gene coexpression network analysis (WGCNA) and least absolute shrinkage and selection operator (LASSO) logistic regression. Expression of biomarkers was verified through experiments. The area under the curve (AUC) of biomarkers was calculated to evaluate their diagnostic value, and differences in immune cell content were examined. In this study, 17 kinds of immune cells with different contents between the SCI group and healthy control (HC) group were identified, with 7 immune cell types being significantly increased. Differences in the content of immune cells between different grades of SCI and the HC group were also discovered. DEIGs were identified, with alteration in some immune-related signaling pathways, vascular endothelial growth factor signaling pathways, and axon guidance signaling pathways. The SCI biomarkers identified and those of American Spinal Injury Society Impairment Scale (AIS) A and AIS D of SCI have certain diagnostic sensitivity. Analysis of the correlation of immune cells and biomarkers showed that biomarkers of SCI, AIS A grade and AIS D grade correlated positively or negatively with some immune cells. CKLF, EDNRB, FCER1G, SORT1, and TNFSF13B can be used as immune biomarkers for SCI. Additionally, GDF11and HSPA1L can be used as biomarkers of SCI AIS A grade; PRKCA and CMTM2 can be used as biomarkers of the SCI AIS D grade. Detecting expression of these putative biomarkers and changes in related immune cells may be helpful for predicting the severity of SCI
Hyaluronic acid ameliorates intervertebral disc degeneration via promoting mitophagy activation
Activation of mitophagy was considered to be a potential therapeutic strategy for intervertebral disc degeneration (IDD). There was evidence suggesting that hyaluronic acid (HA) can protect mitochondria from oxidative stress in chondrocytes, but its protective effects and mechanism in nucleus pulposus cells (NPCs) remain unclear. This study aimed to confirm the effect of HA promoting mitophagy and protecting mitochondria function in NPCs, and explore its underlying mechanism. NPCs were treated with high molecular weight HA, tert-butyl hydroperoxide (TBHP) and Cyclosporin A (CsA). Mitophagy, mitochondrial function, apoptosis, senescence and extracellular matrix (ECM) degradation were measured. Then, NPCs were transfected with C1QBP siRNA, mitophagy and mitochondrial function were tested. The therapeutic effects of HA on IDD by promoting mitophagy were assessed in bovine intervertebral disc organ culture model. The results showed that TBHP induced oxidative stress, mitochondrial dysfunction, NPCs apoptosis, senescence and ECM degradation. Treated by HA, mitophagy was activated, concomitantly, mitochondrial dysfunction, apoptosis, senescence and ECM degradation were ameliorated. Mitophagy inhibition by CsA partially eliminated the protective effects of HA against oxidative stress. After transfected with C1QBP siRNA to reduce the expression of C1QBP in NPCs, the effect of HA promoting mitophagy was inhibited and the protective effect of HA against oxidative stress was weaken. Additionally, HA alleviated NPCs apoptosis and ECM degradation in bovine intervertebral disc organ culture model. These findings suggest that HA can protect mitochondrial function through activation of mitophagy in NPCs and ameliorate IDD. Furthermore, C1QBP is involved in HA promoting mitophagy and protecting NPCs from oxidative stress. Taken together, our results provide substantial evidence for the clinical applications of HA in the prevention and treatment of IDD
A Rare Genetic Defect of MBL2 Increased the Risk for Progression of IgA Nephropathy
The aim of this study was to investigate the association between lectin pathway-related genetic variations and progression in IgA nephropathy. Biopsy-proven IgAN patients with eGFR ≥15 ml/min/1.73 m2 at baseline and a minimum follow-up of 12-months were enrolled. A total of 1,007 patients and 121 healthy controls were enrolled from two Chinese renal centers. The discovery cohort consisted of 606 patients, and the validation cohort consisted of 401 patients. First, promoters, all exons and their boundary regions of MBL2 and FCN2 were sequenced in 50 patients, and then 37 variations were identified. Of these variations, 7 expression-associated variations were selected and genotyped in the whole discovery cohort. We found that rs1800450 in MBL2 and rs7851696 in FCN2 were associated with an increased risk for ESRD as well as serum MBL or L-ficolin levels. However, only rs1800450 was successively validated for its association with ESRD (HR, 15.91; 3.27–77.34; P = 0.001) in the fully adjusted model in the validation cohort. In addition, 2.7% of patients, and 2.5% of healthy controls carried rs1800450-AA. IgAN patients with rs1800450-AA lacked expression of MBL in both serum and renal tissue and had more severe tubulointerstitial damage. Furthermore, a combined effect of rs1800450-AA with a previously reported clinical risk score was observed in which patients with both a high clinical risk score (≥1%) and rs1800450-AA had a strikingly increased 10-years ESRD risk by 37.1-fold (7.17 to 192.13-fold). In summary, IgAN patients carrying MBL2 rs1800450-AA have a high risk for renal function deterioration, probably due to inactivation of the complement MBL pathway
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