20 results on '"Song DF"'
Search Results
2. Active damping control strategy for a parallel hybrid electric vehicle based on model predictive control.
- Author
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Song, DF, Yang, DP, Zeng, XH, and Wang, ZW
- Subjects
- *
HYBRID electric vehicles , *VEHICLE models , *TORSIONAL vibration , *PREDICTION models , *EQUATIONS of motion , *STATE-space methods - Abstract
Since the coupling relationship of excitation sources is complicated, meantime the motor torque changes quickly under the acceleration condition, the problem of torsional vibration is prominent. This paper studies an active damping control (ADC) strategy for a parallel hybrid electric vehicle (HEV) under acceleration condition. Primarily, a full-order dynamic model is built, and the corresponding motion equations are derived. Moreover, a controller design–oriented model is established based on model reduction algorithm. Furthermore, a method that considers time delay characteristics of actuator based on model predictive control (MPC) theory is proposed to solve the torsional vibration problem. The controller handles delay characteristics of an actuator by state-space reorganization method, and the optimal control sequence is obtained by solving the objective function. Finally, the controller is tested using Simulink simulation and hardware-in-loop simulation platform, which mainly includes the verification of model reduction and vibration damping effect. The results show that simplified third-order model has a good consistency with the original full-order model in time and frequency domain. Meanwhile, the designed controller has a considerable damping effect and ensures the comfort performance of the vehicle. This study provides an important reference for vibration control of the hybrid powertrain. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
3. Thermal development of latent fingermarks on porous surfaces-Further observations and refinements
- Author
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Song, DF, Sommerville, D, Brown, AG, Shimmon, RG, Reedy, BJ, and Tahtouh, M
- Subjects
Paper ,Adult ,Male ,Alanine ,Time Factors ,Hot Temperature ,Light ,Adolescent ,Ultraviolet Rays ,Surface Properties ,Textiles ,Ninhydrin ,Sodium Chloride ,Wood ,Oxygen ,Spectrometry, Fluorescence ,Humans ,Indicators and Reagents ,Female ,Legal & Forensic Medicine ,Dermatoglyphics ,Porosity - Abstract
In a further study of the thermal development of fingermarks on paper and similar surfaces, it is demonstrated that direct contact heating of the substrate using coated or ceramic surfaces at temperatures in excess of 230 °C produces results superior to those obtained using hot air. Fingermarks can also be developed in this way on other cellulose-based substrates such as wood and cotton fabric, though ridge detail is difficult to obtain in the latter case. Fluorescence spectroscopy indicates that the phenomena observed during the thermal development of fingermarks can be reproduced simply by heating untreated white copy paper or filter paper, or these papers treated with solutions of sodium chloride or alanine. There is no evidence to suggest that the observed fluorescence of fingermarks heated on paper is due to a reaction of fingermark constituents on or with the paper. Instead, we maintain that the ridge contrast observed first as fluorescence, and later as brown charring, is simply an acceleration of the thermal degradation of the paper. Thermal degradation of cellulose, a major constituent of paper and wood, is known to give rise to a fluorescent product if sufficient oxygen is available [1-5]. However, the absence of atmospheric oxygen has only a slight effect on the thermal development of fingermarks, indicating that there is sufficient oxygen already present in paper to allow the formation of the fluorescent and charred products. In a depletion study comparing thermal development of fingermarks on paper with development using ninhydrin, the thermal technique was found to be as sensitive as ninhydrin for six out of seven donors. When thermal development was used in sequence with ninhydrin and DFO, it was found that only fingermarks that had been developed to the fluorescent stage (a few seconds of heating) could subsequently be developed with the other reagents. In the reverse sequence, no useful further development was noted for fingermarks that were treated thermally after having been developed with ninhydrin or DFO. Aged fingermarks, including marks from 1-year-old university examination papers were successfully developed using the thermal technique. © 2010 Elsevier Ireland Ltd.
- Published
- 2010
4. Thermal development of latent fingermarks on porous surfaces-Further observations and refinements
- Author
-
Song, DF, Sommerville, D, Brown, AG, Shimmon, RG, Reedy, BJ, Tahtouh, M, Song, DF, Sommerville, D, Brown, AG, Shimmon, RG, Reedy, BJ, and Tahtouh, M
- Abstract
In a further study of the thermal development of fingermarks on paper and similar surfaces, it is demonstrated that direct contact heating of the substrate using coated or ceramic surfaces at temperatures in excess of 230 °C produces results superior to those obtained using hot air. Fingermarks can also be developed in this way on other cellulose-based substrates such as wood and cotton fabric, though ridge detail is difficult to obtain in the latter case. Fluorescence spectroscopy indicates that the phenomena observed during the thermal development of fingermarks can be reproduced simply by heating untreated white copy paper or filter paper, or these papers treated with solutions of sodium chloride or alanine. There is no evidence to suggest that the observed fluorescence of fingermarks heated on paper is due to a reaction of fingermark constituents on or with the paper. Instead, we maintain that the ridge contrast observed first as fluorescence, and later as brown charring, is simply an acceleration of the thermal degradation of the paper. Thermal degradation of cellulose, a major constituent of paper and wood, is known to give rise to a fluorescent product if sufficient oxygen is available [1-5]. However, the absence of atmospheric oxygen has only a slight effect on the thermal development of fingermarks, indicating that there is sufficient oxygen already present in paper to allow the formation of the fluorescent and charred products. In a depletion study comparing thermal development of fingermarks on paper with development using ninhydrin, the thermal technique was found to be as sensitive as ninhydrin for six out of seven donors. When thermal development was used in sequence with ninhydrin and DFO, it was found that only fingermarks that had been developed to the fluorescent stage (a few seconds of heating) could subsequently be developed with the other reagents. In the reverse sequence, no useful further development was noted for fingermarks that were treated
- Published
- 2011
5. Absence of the Klotho Function Causes Cornea Degeneration with Specific Features Resembling Fuchs Endothelial Corneal Dystrophy and Bullous Keratopathy.
- Author
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Wu CY, Song DF, Chen ZJ, Hu CS, Lin DP, and Chang HH
- Abstract
The Klotho loss-of-function mutation is known to cause accelerated senescence in many organs, but its effects on the cornea have not been published. The present study aims to investigate the effects of the Klotho null mutation on cornea degeneration and to characterize the pathological features. Mouse corneas of Klotho homozygous, heterozygous, and wild-type mice at 8 weeks of age for both genders were subject to pathological and immunohistological examinations. The results show an irregular topography on the corneal surface with a Klotho null mutation. Histological examinations revealed a reduced corneal epithelial cell density, endothelial cell-shedding, and decreased cornea stromal layer thickness in the absence of the Klotho function. Furthermore, guttae formation and the desquamation of wing cells were significantly increased, which was comparable to the characteristics of Fuchs endothelial corneal dystrophy and bullous keratopathy. The mechanism analysis showed multi-fold abnormalities, including oxidative stress-induced cornea epithelium apoptosis and inflammation, extracellular matrix remodeling in the stroma, and a disruption of epithelial repair, presumably through the epithelial-mesenchymal transition. In conclusion, cornea degeneration was observed in the Klotho loss-of-function mutant mice. These pathological features support the use of Klotho mutant mice for investigating age-related cornea anomalies, including Fuchs endothelial corneal dystrophy, bullous keratopathy, and dry eye diseases.
- Published
- 2024
- Full Text
- View/download PDF
6. Klotho Null Mutation Indirectly Leads to Age-Related Lacrimal Gland Degeneration in Mutant Mice.
- Author
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Wu CY, Song DF, Lu TH, Chen ZJ, Tsai SM, Liu YJ, Chang HH, and Lin DP
- Abstract
The Klotho null mutation is known to lead to accelerated aging in many organs, but its effects on tear secretion and lacrimal gland (LG) senescence have not been addressed. This study investigated whether the Klotho null mutation would lead to a dry eye status and the outcome of LG without Klotho function. The Klotho (
-/- ) mutant mice showed reduced LG size and tear volume on the 8th week, as compared to their littermates (+/+, +/- ). Hematoxylin-Eosin and Masson's trichrome staining were performed to determine morphological changes and collagen deposition. Traits of LG aging, including acinar atrophy, thickened capsules, and more collagen depositions, were observed. Immunohistochemical detections for Klotho, α-SMA, MDA, 8-OHdG, vasoactive intestinal polypeptide (VIP), tyrosine hydroxylase (TH), MMP-2, MMP-9, and FGF-23 were performed and compared among the three genotypes (+/+ ,+/- ,-/- ) at 6 and 8 weeks of age for mechanism analyses. Unexpectedly, the Klotho protein was not detected in the LG of all the three genotypes, indicating indirect effects from the Klotho null mutation. Further analyses showed abundant MDA and 8-OHdG detected in the Klotho (-/- ) LG on the 8th week, indicating elevated oxidative stress. In addition, both sympathetic and parasympathetic neural transducing activities, as represented by TH and VIP expression, respectively, and α-SMA were increased in LGs with Klotho mutations. Furthermore, MMP-2 and MMP-9 expression were elevated, with FGF-23 expression being decreased on the 8th week in the Klotho (-/- ) LG. In conclusion, characteristics of age-related LG degeneration were found in the Klotho null mutant mice. These traits support the use of Klotho mutant mice as a model of age-related dry eye disease.- Published
- 2023
- Full Text
- View/download PDF
7. Impact of sarcopenia and low muscle attenuation on outcomes of ovarian cancer: a systematic review and meta-analysis.
- Author
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Ge HP, Song DF, Wu P, and Xu HF
- Subjects
- Humans, Female, Prospective Studies, Retrospective Studies, Muscle, Skeletal pathology, Prognosis, Sarcopenia pathology, Ovarian Neoplasms pathology
- Abstract
Objective: The aim of this study was to examine the association of sarcopenia and low muscle attenuation with survival and other clinical outcomes in patients with ovarian cancer., Materials and Methods: Systematic search was done in PubMed, EMBASE and Scopus databases for observational studies that documented the link between sarcopenia and outcomes of interest in patients with ovarian cancer, with long-term survival as a primary outcome. Other outcomes included risk of recurrence, progression-free survival and complications. Pooled effect sizes were reported as hazards ratio (HR), relative risk ratio (RR) or weighted mean difference (WMD). Random effects model was used for the analysis., Results: Twenty-two studies were selected, of which all, except one, were retrospective in design. Low skeletal muscle index (SMI, indicating muscle mass) (HR 1.30, 95% CI: 1.07, 1.58) and low muscle quality (HR 1.24, 95% CI: 1.03, 1.49) were associated with poor long-term survival, but not with the risk of recurrence and progression-free survival. Both low skeletal muscle index (SMI) (RR 1.49, 95% CI: 1.13, 1.98) and low muscle quality (RR 1.99, 95% CI: 1.04, 3.79) were associated with increased risk of complications., Conclusions: Both low skeletal muscle mass and low muscle quality showed significant association with poor long-term survival and an increased risk of complications. However, they do not have a significant association with the risk of recurrence and progression-free survival. There is a need for more prospective studies to confirm these associations.
- Published
- 2023
- Full Text
- View/download PDF
8. The Novel Regulatory Role of the lncRNA-miRNA-mRNA Axis in Chronic Inflammatory Airway Diseases.
- Author
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Qiao X, Hou G, He YL, Song DF, An Y, Altawil A, Zhou XM, Wang QY, Kang J, and Yin Y
- Abstract
Chronic inflammatory airway diseases, characterized by airway inflammation and airway remodelling, are increasing as a cause of morbidity and mortality for all age groups and races across the world. The underlying molecular mechanisms involved in chronic inflammatory airway diseases have not been fully explored. MicroRNAs (miRNAs) and long noncoding RNAs (lncRNAs) have recently attracted much attention for their roles in the regulation of a variety of biological processes. A number of studies have confirmed that both lncRNAs and miRNAs can regulate the initiation and progression of chronic airway diseases by targeting mRNAs and regulating different cellular processes, such as proliferation, apoptosis, inflammation, migration, and epithelial-mesenchymal transition (EMT). Recently, accumulative evidence has shown that the novel regulatory mechanism underlying the interaction among lncRNAs, miRNAs and messenger RNAs (mRNAs) plays a critical role in the pathophysiological processes of chronic inflammatory airway diseases. In this review, we comprehensively summarized the regulatory roles of the lncRNA-miRNA-mRNA network in different cell types and their potential roles as biomarkers, indicators of comorbidities or therapeutic targets for chronic inflammatory airway diseases, particularly chronic obstructive pulmonary disease (COPD) and asthma., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Qiao, Hou, He, Song, An, Altawil, Zhou, Wang, Kang and Yin.)
- Published
- 2022
- Full Text
- View/download PDF
9. Cholecystokinin type 2 receptor in colorectal cancer: diagnostic and therapeutic target.
- Author
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Chang J, Liu ZS, Song DF, Li M, Zhang S, Zhao K, Guan YT, Ren HL, Li YS, Zhou Y, Liu XL, Lu SY, and Hu P
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, Cell Line, Tumor, Disease-Free Survival, Female, Gene Expression Regulation, Neoplastic genetics, HCT116 Cells, HT29 Cells, Hep G2 Cells, Humans, Male, Middle Aged, Prognosis, Colorectal Neoplasms genetics, Colorectal Neoplasms pathology, Receptor, Cholecystokinin B genetics
- Abstract
Introduction: Cholecystokinin type 2 receptor (CCK2R), which mediates the action of gastrin and cholecystokinin (CCK), has been demonstrated to promote the proliferation of colorectal cancer (CRC). A number of studies showed that CCK2R overexpressed in gastric cancer and pancreatic cancer but few in CRC. The correlation between CCK2R expression and clinicopathological characteristics is also not clear., Methods: This study investigated CCK2R expression in a wide range of cell lines and clinical CRC samples, and explored expression pattern and prognostic value of CCK2R in relation to clinicopathological parameters. The location and expression levels of CCK2R were measured by immunocytochemical (ICC), qRT-PCR and Western blot. The druggability and antineoplastic effects of CCK2R as a therapeutic target were investigated using an anti-CCK2R targeting recombinant toxin named rCCK8PE38 by CCK-8 assay., Results: Compared with paracarcinoma tissues, tumor samples showed overexpression of CCK2R (p = 0.028) including both CRC tissue and plasma samples, with plasma detection showing a significant indication for CCK2R evaluation. Aberrant expression correlated significantly with histological type (p = 0.032) and p53 status (p < 0.01), and patients with CCK2R overexpression had significantly lower disease-free survival. Application of rCCK8PE38 demonstrated the specificity and druggability of CCK2R as a therapeutic target, providing a strategy for clinical case screening of drugs targeting CCK2R., Conclusion: This study highlighted the aberrant expression and clinical correlation of CCK2R and reveals its diagnostic, prognostic and treatment value in CRC. We hypothesize that CCK2R serve as a target for the diagnosis and treatment of this cancer.
- Published
- 2020
- Full Text
- View/download PDF
10. Reverse transcription - loop-mediated isothermal amplification assay for the rapid detection of pathogenic Listeria monocytogenes in meat products.
- Author
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Zhan LZ, Song DF, Gu Q, Yan TT, and Ma CC
- Subjects
- Animals, Bacterial Proteins genetics, Lipoproteins genetics, Listeria monocytogenes genetics, Meat microbiology, Sensitivity and Specificity, Food Microbiology methods, Listeria monocytogenes isolation & purification, Meat Products microbiology, Nucleic Acid Amplification Techniques
- Abstract
This study reports the use of reverse transcription - loop-mediated isothermal amplification (RT-LAMP) to detect Listeria monocytogenes in meat. The assay was designed to target the iap gene of L. monocytogenes , to which four primers, recognizing six distinct iap sites, were designed. We optimized the RT-LAMP conditions and established the following optimal systems: 60 min, 63 °C, 2.0 mmol/L MgSO
4 , 1.0 mol/L betaine, 2.0 mmol/L dNTPs, 320 U/mL Bst DNA polymerase, 0.4 μmol/L outer primers, and 0.8 μmol/L inner primers. The RT-LAMP amplification products were identified by a visible white Mg2 P2 O7 precipitate or electrophoresis on a 2% agarose gel. RT-LAMP has a sensitivity of 7.3 × 101 CFU/mL, which is 2-fold higher than that of LAMP. When commercially available raw meat samples (including beef, pork, mutton, and rabbit) were analyzed simultaneously with RT-LAMP and the Chinese National Standard GB 4789.30-2016, their abilities to detect L. monocytogenes were the same. Samples containing L. monocytogenes killed by 15 psi at 121 °C for 15 min were used to confirm the specificity of RT-LAMP for live microorganisms. Thus, we used RT-LAMP to efficiently detect L. monocytogenes in meat products.- Published
- 2019
- Full Text
- View/download PDF
11. MicroRNA-206 facilitates gastric cancer cell apoptosis and suppresses cisplatin resistance by targeting MAPK2 signaling pathway.
- Author
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Chen Z, Gao YJ, Hou RZ, Ding DY, Song DF, Wang DY, and Feng Y
- Subjects
- Apoptosis genetics, Cell Line, Tumor, Cisplatin therapeutic use, Gene Expression Profiling, Gene Expression Regulation, Neoplastic, Humans, MAP Kinase Signaling System genetics, Mitogen-Activated Protein Kinase 3 metabolism, Phosphorylation genetics, Stomach Neoplasms genetics, Stomach Neoplasms pathology, Cisplatin pharmacology, Drug Resistance, Neoplasm genetics, MicroRNAs metabolism, Mitogen-Activated Protein Kinase 3 genetics, Stomach Neoplasms drug therapy
- Abstract
Objective: Mitogen activating protein kinase 3 (MAPK3) is critical in extracellular signal-regulated kinase (ERK)/MAPK pathway. Gastric cancer tissues have microRNA-206 (miR-206) down-regulation. This study aimed to investigate the role of miR-206 in MAPK3 expression, gastric cancer cell proliferation, apoptosis, and cisplatin (DDP) resistance., Materials and Methods: Dual-Luciferase reporter gene assay confirmed targeted regulation between miR-206 and MAPK3. DDP resistant cell line BGC823/DDP and SGC7901/DDP were generated for comparing miR-206 and MAPK3 expression against parental cells using quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) and Western blot, followed by flow cytometry measuring apoptosis. Drug-resistant cells were transfected with miR-206 mimic for measuring MAPK3 and phosphorylated MAPK3 (p-MAPK3) expression. Flow cytometry and EdU were employed for measuring cell apoptosis and proliferation., Results: Targeted regulation existed between miR-206 and MAPK3 mRNA. BGC823/DDP and SGC7901/DDP cell presented lower miR-206 than parental cells, plus higher MAPK3 mRNA or protein. Under DDP treatment equivalent to IC50 of parental cells, drug-resistant cells presented lower apoptosis compared to parental drug-sensitive cells. Compared to miR-normal control (miR-NC) group, miR-206 mimic transfection significantly decreased MAPK3 and p-MAPK3 protein expression (p < 0.05), enhanced cell apoptosis and weakened proliferation potency (p < 0.05)., Conclusions: The down-regulation of miR-206 is associated with DDP resistance of gastric cancer cells. Up-regulating miR-2016 expression can weaken the proliferation of drug-resistant gastric cancer cells, facilitate cell apoptosis and decrease DDP resistance via targeted inhibition of MAPK3 expression.
- Published
- 2019
- Full Text
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12. Dysregulation of NCAPG, KNL1, miR-148a-3p, miR-193b-3p, and miR-1179 may contribute to the progression of gastric cancer.
- Author
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Song B, Du J, Song DF, Ren JC, and Feng Y
- Subjects
- Biomarkers, Tumor genetics, Cell Cycle Proteins genetics, Disease Progression, Gene Expression Profiling, Humans, Microtubule-Associated Proteins metabolism, Real-Time Polymerase Chain Reaction, Stomach Neoplasms diagnosis, Stomach Neoplasms genetics, Cell Cycle Proteins metabolism, Gene Expression Regulation, Neoplastic genetics, MicroRNAs metabolism, Stomach Neoplasms metabolism, Up-Regulation genetics
- Abstract
Background: Emerging evidence indicate that miRNAs play an important role on gastric cancer (GC) progression via regulating several downstream targets, but it is still partially uncovered. This study aimed to explore the molecular mechanisms of GC by comprehensive analysis of mRNAs and miRNA expression profiles., Methods: The mRNA and miRNA expression profiles of GSE79973 and GSE67354 downloaded from Gene Expression Omnibus were used to analyze the differentially expressed genes (DEGs) and DE-miRNAs among GC tissues and normal tissues. Then, targets genes of DE-miRNAs were predicted and the DE-miRNA-DEG regulatory network was constructed. Next, function enrichment analysis of the overlapped genes between the predicted DE-miRNAs targets and DEGs was performed and a protein-protein interactions network of overlapped genes was constructed. Finally, RT-PCR analysis was performed to detect the expression levels of several key DEGs and DE-miRNAs., Results: A set of 703 upregulated and 600 downregulated DEGs, as well as 8 upregulated DE-miRNAs and 27 downregulated DE-miRNAs were identified in GC tissue. hsa-miR-193b-3p and hsa-miR-148a-3p, which targeted most DEGs, were highlighted in the DE-miRNA-DEG regulatory network, as well as hsa-miR-1179, which targeted KNL1, was newly predicted to be associated with GC. In addition, NCAPG, which is targeted by miR-193b-3p, and KNL1, which is targeted by hsa-miR-1179, had higher degrees in the PPI network. RT-qPCR results showed that hsa-miR-148a-3p, hsa-miR-193b-3p, and hsa-miR-1179 were downregulated, and NCAPG and KNL1 were upregulated in GC tissues; this is consistent with our bioinformatics-predicted results., Conclusions: The downregulation of miR-193b-3p might contribute to GC cell proliferation by mediating the upregulation of NCAPG; as additionally, the downregulation of miR-193b-3p might contribute to the mitotic nuclear division of GC cells by mediating the upregulation of KNL1.
- Published
- 2018
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13. Comparative genomic analysis of Lactobacillus plantarum ZJ316 reveals its genetic adaptation and potential probiotic profiles.
- Author
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Li P, Li X, Gu Q, Lou XY, Zhang XM, Song DF, and Zhang C
- Subjects
- Amino Acids biosynthesis, Bacterial Adhesion, Bacterial Capsules metabolism, Bacteriocins biosynthesis, Carbon metabolism, Clustered Regularly Interspaced Short Palindromic Repeats, Lactobacillus plantarum classification, Phylogeny, Lactobacillus plantarum genetics, Probiotics
- Abstract
Objective: In previous studies, Lactobacillus plantarum ZJ316 showed probiotic properties, such as antimicrobial activity against various pathogens and the capacity to significantly improve pig growth and pork quality. The purpose of this study was to reveal the genes potentially related to its genetic adaptation and probiotic profiles based on comparative genomic analysis., Methods: The genome sequence of L. plantarum ZJ316 was compared with those of eight L. plantarum strains deposited in GenBank. BLASTN, Mauve, and MUMmer programs were used for genome alignment and comparison. CRISPRFinder was applied for searching the clustered regularly interspaced short palindromic repeats (CRISPRs)., Results: We identified genes that encode proteins related to genetic adaptation and probiotic profiles, including carbohydrate transport and metabolism, proteolytic enzyme systems and amino acid biosynthesis, CRISPR adaptive immunity, stress responses, bile salt resistance, ability to adhere to the host intestinal wall, exopolysaccharide (EPS) biosynthesis, and bacteriocin biosynthesis., Conclusions: Comparative characterization of the L. plantarum ZJ316 genome provided the genetic basis for further elucidating the functional mechanisms of its probiotic properties. ZJ316 could be considered a potential probiotic candidate.
- Published
- 2016
- Full Text
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14. Purification and characterization of Plantaricin ZJ5, a new bacteriocin produced by Lactobacillus plantarum ZJ5.
- Author
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Song DF, Zhu MY, and Gu Q
- Subjects
- Amino Acid Sequence, Bacteriocins chemistry, Bacteriocins genetics, Base Sequence, Lactobacillus plantarum genetics, Molecular Sequence Data, Molecular Weight, Antibiosis, Bacteriocins biosynthesis, Bacteriocins isolation & purification, Lactobacillus plantarum metabolism
- Abstract
The aim of this study is to investigate the antimicrobial potential of Lactobacillus plantarum ZJ5, a strain isolated from fermented mustard with a broad range of inhibitory activity against both Gram-positive and Gram-negative bacteria. Here we present the peptide plantaricin ZJ5 (PZJ5), which is an extreme pH and heat-stable. However, it can be digested by pepsin and proteinase K. This peptide has strong activity against Staphylococcus aureus. PZJ5 has been purified using a multi-step process, including ammonium sulfate precipitation, cation-exchange chromatography, hydrophobic interactions and reverse-phase chromatography. The molecular mass of the peptide was found to be 2572.9 Da using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The primary structure of this peptide was determined using amino acid sequencing and DNA sequencing, and these analyses revealed that the DNA sequence translated as a 44-residue precursor containing a 22-amino-acid N-terminal extension that was of the double-glycine type. The bacteriocin sequence exhibited no homology with known bacteriocins when compared with those available in the database, indicating that it was a new class IId bacteriocin. PZJ5 from a food-borne strain may be useful as a promising probiotic candidate.
- Published
- 2014
- Full Text
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15. Identification of effective combinatorial markers for quality standardization of herbal medicines.
- Author
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Shi ZQ, Song DF, Li RQ, Yang H, Qi LW, Xin GZ, Wang DQ, Song HP, Chen J, Hao H, and Li P
- Subjects
- Acetylcholinesterase metabolism, Drugs, Chinese Herbal analysis, Drugs, Chinese Herbal chemistry, Humans, Mass Spectrometry, Quality Control, Cholinesterase Inhibitors analysis, Herbal Medicine standards, Plants, Medicinal chemistry
- Abstract
Quality standardization of herbal medicines (HMs) is an important task with great challenges. Selection of abundant compounds as markers is currently a major approach for the quality control of HMs; however, such marker compounds are irrelevant to the bioactivities in many cases. Taking Lycoridis Radiatae Bulbus (LRB) as an example, we proposed a universal strategy to identify the effective combinatorial markers (ECMs) that are representative of the bioactivities of HMs, and took them as chemical markers for quality standardization. Fingerprinting and quantification were employed to find out the common components in various batches of medicines. The contribution of each common compound to the overall bioactivity was determined through fingerprint-bioactivity modeling, which based on the absolute quantification of each compound and the acetylcholinesterase (AChE) inhibitory activity of LRB. Two most effective compounds, ungerimine and galanthamine, were therefore proposed as ECMs. Interestingly, these two compounds could synergistically inhibit AChE. This approach demonstrated its strong advantage of the bioactivity relevant quality assessment when compared with conventional methods. And the success of applying this ECMs-based method to the quality assessment of unknown LRB samples proved that our approach was reliable and reproducible. In conclusion, this approach is not only useful for the bioactivity relevant quality control of HMs but also helpful for the discovery of ECMs as new drug candidates., (Copyright © 2014 Elsevier B.V. All rights reserved.)
- Published
- 2014
- Full Text
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16. Mutational analysis of positively charged residues in the N-terminal region of the class IIa bacteriocin pediocin PA-1.
- Author
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Song DF, Li X, Zhang YH, Zhu MY, and Gu Q
- Subjects
- Amino Acid Sequence, Anti-Bacterial Agents pharmacology, Bacteriocins genetics, Bacteriocins pharmacology, Molecular Sequence Data, Mutagenesis, Site-Directed, Pediocins, Sequence Alignment, Anti-Bacterial Agents chemistry, Bacteriocins chemistry
- Abstract
Unlabelled: The significance of positively charged residues for the target cell binding of pediocin PA-1 bacteriocins was studied by site-directed mutagenesis. Most of the charged residues are located in the N-terminal half of the peptide, which is thought to mediate the initial binding of these bacteriocins to their target cells through electrostatic interactions. Mutated peptides in which the positively charged residues were substituted or increased in number were constructed, and some of these peptides exhibited a twofold increase in the bacteriostatic activity. The greatest enhancement was achieved by introduced the positive charges at position 13, their results show the benefits of introducing an additional cationic residue within this patch in the middle of the N-terminal half of pediocin PA-1 bacteriocins. Thus, the presence of additional cationic residues in the N-terminal half influenced the electrostatic binding of this bacteriocin to its target cells and increased the potency of the peptide on the potency of Micrococcus luteus and Staphylococcus aureus., Significance and Impact of the Study: No previous work has systematically examined the N-terminal cationic residues of the pediocin PA-1 for their functional importance or redundancy. In this study, we examined the structure-function relationships of pediocin PA-1 by site-directed mutagenesis. Mutated peptides in which the positively charged residues were substituted and increased in number exhibited a twofold increase in the bacteriostatic activity. This study demonstrated the importance of the cationic patch in the N-terminal half of pediocin PA-1. The cationic residues influenced the electrostatic binding of the bacteriocin to the target cells and had a greater effect on the potency of the peptide towards Micrococcus luteus and Staphylococcus aureus., (© 2013 The Society for Applied Microbiology.)
- Published
- 2014
- Full Text
- View/download PDF
17. Thermal development of latent fingermarks on porous surfaces--further observations and refinements.
- Author
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Song DF, Sommerville D, Brown AG, Shimmon RG, Reedy BJ, and Tahtouh M
- Subjects
- Adolescent, Adult, Alanine, Female, Humans, Indicators and Reagents, Light, Male, Ninhydrin, Oxygen analysis, Paper, Sodium Chloride, Spectrometry, Fluorescence, Surface Properties, Textiles, Time Factors, Ultraviolet Rays, Wood, Dermatoglyphics, Hot Temperature, Porosity
- Abstract
In a further study of the thermal development of fingermarks on paper and similar surfaces, it is demonstrated that direct contact heating of the substrate using coated or ceramic surfaces at temperatures in excess of 230°C produces results superior to those obtained using hot air. Fingermarks can also be developed in this way on other cellulose-based substrates such as wood and cotton fabric, though ridge detail is difficult to obtain in the latter case. Fluorescence spectroscopy indicates that the phenomena observed during the thermal development of fingermarks can be reproduced simply by heating untreated white copy paper or filter paper, or these papers treated with solutions of sodium chloride or alanine. There is no evidence to suggest that the observed fluorescence of fingermarks heated on paper is due to a reaction of fingermark constituents on or with the paper. Instead, we maintain that the ridge contrast observed first as fluorescence, and later as brown charring, is simply an acceleration of the thermal degradation of the paper. Thermal degradation of cellulose, a major constituent of paper and wood, is known to give rise to a fluorescent product if sufficient oxygen is available [1-5]. However, the absence of atmospheric oxygen has only a slight effect on the thermal development of fingermarks, indicating that there is sufficient oxygen already present in paper to allow the formation of the fluorescent and charred products. In a depletion study comparing thermal development of fingermarks on paper with development using ninhydrin, the thermal technique was found to be as sensitive as ninhydrin for six out of seven donors. When thermal development was used in sequence with ninhydrin and DFO, it was found that only fingermarks that had been developed to the fluorescent stage (a few seconds of heating) could subsequently be developed with the other reagents. In the reverse sequence, no useful further development was noted for fingermarks that were treated thermally after having been developed with ninhydrin or DFO. Aged fingermarks, including marks from 1-year-old university examination papers were successfully developed using the thermal technique., (Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.)
- Published
- 2011
- Full Text
- View/download PDF
18. [Effects of cu2+ on biosynthesis of camptothecin in cell cultures of Camptotheca acuminata].
- Author
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Gu Q, Song DF, Zhang H, and Zhu MY
- Subjects
- Anthocyanins biosynthesis, Camptotheca growth & development, Light, Antineoplastic Agents, Phytogenic biosynthesis, Camptotheca metabolism, Camptothecin biosynthesis, Copper pharmacology
- Abstract
Camptothecin is a strong anti-tumor compound isolated from Camptotheca acuminata. One of the most important way for the production of Camptothecin is by cell cultures of Camptotheca acuminata. The effect of Cu2+ on camptothecin accumulation in Camptotheca acuminata cell line was described in this paper. The results showed that the optimum CuCl2 concentration in B5 medium was 0.008 mg/mL, which increased camptothecin production for 30 times compare to the control while has no inhibitive effects on cell growth, at the same time, the peroxidase activity was increased and the anthocyanidin accumulation was inhibited. The promotive effects of Cu2+ on camptothecin accumulation in light was higher than that in dark.
- Published
- 2006
19. Blocking effects of genistein on cell proliferation and possible mechanism in human gastric carcinoma.
- Author
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Cui HB, Na XL, Song DF, and Liu Y
- Subjects
- Blotting, Western, Cell Cycle Proteins metabolism, Cell Division drug effects, Cell Line, Tumor cytology, Cell Line, Tumor drug effects, Cell Line, Tumor metabolism, Cyclin B metabolism, Cyclin B1, Cyclin D1 metabolism, Cyclin-Dependent Kinase Inhibitor p21, Flow Cytometry, Humans, Antineoplastic Agents pharmacology, Genistein pharmacology, Stomach Neoplasms
- Abstract
Aim: To study the blocking effects of genistein on cell proliferation cycle in human gastric carcinoma cells (SGC-7901) and the possible mechanism., Methods: MTT assay was applied in the detection of the inhibitory effects of genistein on cell proliferation. Flow cytometry was used to analyze the cell cycle distribution. Immunocytochemical technique and Western blotting were performed to detect the protein expression of cyclin D1, cyclin B1 and p21(waf1/cip1)., Results: Genistein significantly inhibited the growth and proliferation of human gastric carcinoma cells (SGC-7901). Seven days after treatment with different concentrations of genistein (2.5, 5.0, 10.0, 20.0 microg/mL), the growth inhibitory rates were 11.2%, 28.8%, 55.3%, 84.7% respectively and cell cycles were arrested at the G(2)/ M phase. Genistein decreased cyclin D1 protein expression and enhanced cyclin B1 and p21(waf/cip1) protein expression in a concentration-dependent manner., Conclusion: The growth and proliferation of SGC-7901 cells can be inhibited by genistein via blocking the cell cycle, with reduced expression of cyclin D1 and enhanced expression of cyclin B1 and p21(waf/cip1) protein in the concentration range of 0-20 microg/mL.
- Published
- 2005
- Full Text
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20. [Effect of apoptosis in human breast cancer cells and its probable mechanisms by genistein].
- Author
-
Liu Y, Zhang YM, Song DF, and Cui HB
- Subjects
- Cell Line, Tumor, Female, Humans, Receptor, ErbB-2 metabolism, bcl-2-Associated X Protein metabolism, Anticarcinogenic Agents pharmacology, Apoptosis drug effects, Breast Neoplasms pathology, Genistein pharmacology
- Abstract
Objective: To investigate the effects of genistein on human breast cancer cell MCF-7 apoptosis and its probable mechanisms., Methods: In this study, the methods of MTT, cell apoptosis detecting in fluorescent and electronic microscope and flow cytometry, and expression of Bax and erbB-2 protein were employed., Results: The results showed that genistein could significantly inhibit the growth and induce the apoptosis of MCF-7 cells. Apoptotic cells of morphology from MCF-7 cells treated by different concentrations of genistein were observed by fluorescent and electronic microscope and the frequency of apoptosis in MCF-7 cells by flow cytometry showed increasingly with concentrations of genistein increased. The expression of Bax protein in MCF-7 cells was increased and the expression of erbB-2 protein was decreased with the doses of genistein., Conclusion: Genistein can induce MCF-7 cells apoptosis and it may be one of the mechanisms for the inhibitory effect of genistein in human cancer cells.
- Published
- 2005
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