41 research outputs found
Effect of OP/TX emulsifiers on the effectiveness of pressurised dewatering of coal slurry and the structure of the filter cake
The effect of two surfactants, octylphenol ethoxylate (OP-10) and nonylphenol ethoxylate (TX-10), on the pressurised dewatering of coal slurry, was investigated by using a new intelligent monitoring test device designed independently to monitor the effect of pressurised dewatering, The mechanism of the effect of surfactants on the dewatering effect of coal slurry was analysed by means of filter press dewatering tests, average mass-specific resistance measurements, Capillary absorption time (CST) measurements, wetting heat measurements, compression dewatering index measurements and CT tests. The results of the filter press dewatering test, average mass-specific resistance measurement and CST measurement showed that both OP-10 and TX-10 can improve the dewatering effect of coal slurry under pressure, and the best dosage of OP-10 is 200 g/t, at which time the average mass-specific resistance of the filter cake is 5.21×106 m/kg, the maximum CST reduction rate is 14.25%, the filtration speed is 88.45% higher than that of the original coal slurry, and the moisture content is 16.7%. The optimum dosage of TX-10 was 400 g/t, which resulted in an average mass-specific resistance of 9.31×106 m/kg, a maximum CST reduction of 13.36%, an increase in filtration speed of 76.57% and a moisture content of 18.2% compared to the original coal slurry. The wetting heat measurement results showed that the wetting heat of OP-10 was 1.196 J/g and that of TX-10 was 4.11 J/g. The hydrophilicity of TX-10 was higher than that of OP-10 and it was difficult to dewater compared with OP-10, so the filter press dewatering effect of OP-10 surfactant was better than TX-10. The three stages of the filter cake forming process were obtained through the analysis of the pressure-deformation relationship of the filter cake, and it was found that the compression dewatering stage was closely related to the dewatering effect, and the compression dewatering index CDI was further defined. The lower the CDI, the higher the compressibility of the filter cake, the greater the reduction of the thickness of the filter cake under the same pressure, and the lower the moisture, and the compression dewatering index under the action of OP-10 and TX-10 at the optimal concentration were 147.18 and 155.35 respectively. The effective porosity of the original sample was 11.96% with poor connectivity and a large proportion of isolated pores, while the effective porosity of the filter cake was 20.43% with good connectivity and a significant decrease in tortuosity to 1.9 when OP-10 was added at a concentration of 200 g/t. The permeability of the filter cake gradually increases, and the average mass specific resistance is smaller, so it can improve the dewatering effect
3-Hydroxyphthalic Anhydride- Modified Rabbit Anti-PAP IgG as a Potential Bifunctional HIV-1 Entry Inhibitor
Several studies have reported that amyloid fibrils in human semen formed from a naturally occurring peptide fragment of prostatic acidic phosphatase (PAP248-286), known as semen-derived enhancer of viral infection (SEVI), could dramatically enhance human immunodeficiency virus type 1 (HIV-1) infection. Accordingly, SEVI might serve as a novel target for new antiviral drugs or microbicide candidates for the prevention of sexually transmitted HIV. Theoretically, a special anti-PAP or anti-SEVI antibody could reduce the enhancement of viral infection by blocking the binding of HIV and SEVI fibrils. Here, 3-hydroxyphthalic anhydride modified anti-PAP248-286 antibody, named HP-API, exhibited broad-spectrum and highly effective anti-HIV-1 activities on different subtypes and tropism. By using time-of-addition, cell–cell fusion and a single-cycle HIV-1 infection assays, we demonstrated that HP-API is an HIV-1 entry/fusion inhibitor. Mechanism studies suggest that HP-API inhibited HIV-1 entry/fusion by targeting both HIV-1 gp120 envelop and CD4 receptor on the host cell specifically. It is noteworthy that HP-API abrogated the formation of SEVI fibrils and partially interfered with SEVI-mediated enhancement of HIV-1 infection. Based on these findings, HP-API could be considered a bifunctional HIV-1 entry/fusion inhibitor with high potential
The antibacterial activity and mechanism of a novel peptide MR-22 against multidrug-resistant Escherichia coli
IntroductionBacterial infections have become serious threats to human health, and the excessive use of antibiotics has led to the emergence of multidrug-resistant (MDR) bacteria. E. coli is a human bacterial pathogen, which can cause severe infectious. Antimicrobial peptides are considered the most promising alternative to traditional antibiotics.Materials and methodsThe minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and hemolytic activity were determined by the microdilution method. The antimicrobial kinetics of MR-22 against E. coli were studied by growth curves and time-killing curves. The cytotoxicity of MR-22 was detected by the CCK-8 assay. The antimicrobial activity of MR-22 in salt, serum, heat and trypsin was determined by the microdilution method. The antimicrobial mechanism of MR-22 against drug-resistant E. coli was studied by Scanning Electron Microscope, laser confocal microscopy, and Flow Cytometry. The in vivo antibacterial activity of MR-22 was evaluated by the mice model of peritonitis.Results and discussionIn this study, MR-22 is a new antimicrobial peptide with good activity that has demonstrated against MDR E. coli. The antimicrobial activity of MR-22 exhibited stability under conditions of high temperature, 10% FBS, and Ca2+. However, a decline of the activity was observed in the presence of Na+, serum, and trypsin. MR-22 had no significant cytotoxicity or hemolysis in vitro. SEM and fluorescent images revealed that MR-22 could disrupt the integrity of cell membrane. DCFH-DA indicated that MR-22 increased the content of reactive oxygen species, while it decreased the content of intracellular ATP. In mice model of peritonitis, MR-22 exhibited potent antibacterial activity in vivo. These results indicated that MR-22 is a potential drug candidate against drug-resistant E. coli
Free Radical Scavenging Effect and Immunomodulatory Activity of Total Saponins Extract of Ginseng Fibrous Roots
Ginseng (Panax ginseng C.A. Mey) is known for its rich saponin compounds and tonic effects. To better utilize the medicinal value of ginseng, this study investigated the extraction process, components, free radical scavenging ability, and immunomodulatory activity of total saponins of ginseng fibrous roots. The response surface methodology was employed to optimize the extraction process of total saponins, and Q-Orbitrap high-resolution liquid chromatography–mass spectrometry (LC-MS) was used to identify the chemical constituents in the total saponins extract of ginseng fibrous roots (GRS). The results showed that the optimal extraction process was achieved with an ethanol concentration of 68%, a material–solvent ratio of 1:25 mL/g, and an extraction time of 20 min, yielding a total saponin content of 6.34% under these conditions. The extract contained four terpenoid compounds and four polyphenolic compounds. GRS exhibited considerable scavenging activity against DPPH and ABTS radicals, with IC50 values of 0.893 and 0.210 mg/mL, respectively. Moreover, GRS restored immune suppression in mice by increasing white blood cell, red blood cell, and neutrophil counts, and improving the lymphocyte. It also promoted immune system recovery, as evidenced by elevated serum levels of IL-2, IFN-γ, TNF-α, and IL-1β in mice. GRS is a natural compound with promising potential for developing antioxidants and immunomodulatory foods
Potential habitat areas and priority protected areas of Tilia amurensis Rupr in China under the context of climate change
IntroductionTilia amurensis Rupr (T. amurensis) is one endangered and national class II key protected wild plant in China. It has ornamental, material, economic, edible and medicinal values. At present, the resources of T. amurensis are decreasing, and the prediction of the distribution of its potential habitat in China can provide a theoretical basis for the cultivation and rational management of this species.MethodsIn this study, the R language was used to evaluate 358 distribution records and 38 environment variables. The MaxEnt model was used to predict the potential distribution areas of T. amurensis under the current and future climate scenarios. The dominant environmental factors affecting the distribution of T. amurensis were analyzed and the Marxan model was used to plan the priority protected areas of this species.ResultsThe results showed that Bio18, Slope, Elev, Bio1, Bio9 and Bio2 were the dominant environmental factors affecting the distribution of T. amurensis. Under the future climatic scenarios, the potential suitable areas for T. amurensis will mainly distribute in the Northeast China, the total suitable area will reduce compared with the current climate scenarios, and the general trend of the centroid of suitable habitat will be towards higher latitudes. The SPF value of the best plan obtained from the priority conservation area planning was 1.1, the BLM value was 127,616, and the priority conservation area was about 57.61×104 km2. The results suggested that climate, soil and topographic factors jointly affected the potential geographical distribution of T. amurensis, and climate and topographic factors had greater influence than soil factors.DiscussionThe total suitable area of T. amurensis in China under different climate scenarios in the future will decrease, so more effective protection should be actively adopted
Application of CPI cutoff value based on parentage testing of duos and trios typed by four autosomal kits.
In this study, we analyzed the application of four autosomal kits and the sensitivity of the combined paternity index (CPI) cutoff value (CPI≥10000) in parentage testing. First, 1442 real trios and 803 real duos were tested using the Goldeneye 25A kit. The Goldeneye 25A kit covers the autosomal short tandem repeat (STR) loci of the other three kits, so we calculated the CPI value of every case for the four kits. Second, three complex close relative kinship cases were also analyzed to evaluate the application of the CPI cutoff value. The CPI values of all trio cases were higher than 10000 using the four kits; the CPI values of all duo cases were higher than 10000 using the Goldeneye 25A kit; and the CPI values of a portion of the duo cases were lower than 10000 using the other three kits. In the three complex close relative cases, the alleged father or mother was not excluded using 40 autosomal STRs. Adding X chromosome short tandem repeats (X-STR) and samples of biological fathers or mothers, the conclusions were confirmed. The four kits were adequate to draw conclusions in the trio cases; the Goldeneye 25A Kit was adequate to draw conclusions in the duo cases; and the other three kits were not sufficient for a portion of the duo cases. The CPI cutoff value was sensitive for real trio and duo cases. In complex close relative kinship cases, high CPI values may result in false conclusions
Synergistic antitumor activity between HER2 antibody-drug conjugate and chemotherapy for treating advanced colorectal cancer
Abstract Colorectal cancer (CRC) is the third most common cancer associated with a poor prognosis. Effective targeted therapy alone or in combination for treating advanced CRC remains to be a major clinical challenge. Here, we propose the therapeutic efficacy and molecular mechanism underlying RC48, a FDA-approved anti-HER2 antibody conjugate via a cleavable linker to the microtubule inhibitor monomethyl auristatin E (MMAE), either alone or in combination with gemcitabine (GEM) in various models of HER2-positive advanced CRC. Our findings demonstrated that HER2 was widely expressed and located on the plasma membrane of CRC patient specimens, PDX xenograft tumors and cell lines. It confirmed that RC48 alone significantly targeted and eradicated HER2 positive CRC tumor in these models. Moreover, we screened a panel of FDA-approved first-line chemotherapy drugs in vitro. We found that GEM exhibited stronger antiproliferative activity compared to the other first-line anti-cancer agents. Furthermore, combination therapy of RC48 and GEM significantly showed synergetic antitumor activity in vitro and in vivo. To gain further mechanistic insights into the combination therapy, we performed RNA-seq analysis. The results revealed that combination treatment of RC48 and GEM regulated multiple signaling pathways, such as PI3K-AKT, MAPK, p53, Foxo, apoptosis, cell cycle and cell senescence, etc., to exert its antitumor activity in CRC cells. Collectively, these preclinical findings demonstrated that RC48 alone or combinational therapy exerted promising antitumor activity, and meriting the preclinical framework for combinational therapy of anti-HER2 drug conjugate drug and chemotherapy drugs for HER2-positive patients with advanced CRC