The hot-drawing process of polyacrylonitrile (PAN) fibers is an important step during the production of PAN-based carbon fibers. In this study, supercritical carbon dioxide (Sc-CO₂) was used as one ...kind of media for thermal stretching of PAN fibers to study the effect of different pressures of Sc-CO₂ on crystallinity, degree of orientation and mechanical property of PAN fibers during the hot-drawing process. The changes of microstructure and mechanical properties in the PAN fibers were investigated by wide-angle X-ray diffraction, small angle X-ray scattering and monofilament strength analysis. The results showed that as the pressure increased, the crystallinity and degree of orientation of PAN fibers increased. Furthermore, when the pressure was 10 MPa, the crystallinity increased from 69.78% to 79.99%, which was the maximum crystallinity among the different pressures. However, when the pressure was further increased, the crystallinity and degree of orientation of the fibers were reduced. The test results of the mechanical properties were consistent with the trends of crystallinity and degree of orientation, showing that when the pressure was 10 MPa, the tensile strength of the fibers increased from 4.59 cN·dtex
to 7.06 cN·dtex
and the modulus increased from 101.54 cN·dtex
to 129.55 cN·dtex
.
Gold nanosphere (AuS) is a nanosized particle with inert, biocompatible, easily modified surface functionalization and adequate cell penetration ability. Photothermal, photochemical, and vapor ...effects of AuS could be activated by irradiating with nanosecond laser to cause cell death. Hence, AuS-mediated phototherapy irradiated with nanosecond laser is a promising and minimally-invasive treatment method for cancer therapy. However, various effects require different parameters to be activated. At present, few studies have reported on the influence of parameters of AuS inducing cell death under nanosecond laser irradiation. This makes it very challenging to optimize gold-nanoparticle-mediated specific or synergistic anti-cancer therapy. In this study, we revealed the main parameters and threshold values for AuS-mediated gastric cancer phototherapy with nanosecond pulsed laser irradiation, evaluated the pathway of induced cell death, and discussed the roles of photothermal, photochemical and vapor effects which can induce the cell death. The results showed that AuS-mediated phototherapy activated with nanosecond pulsed laser is an effective method for gastric therapy, mainly based on the photochemical effect. Prolonging the incubation time could decrease the irradiation dose, increase ROS-mediated photothermal effect and vapor effect, and then quickly induce cell death to improve security.
A cost-effective and facile method was developed for the fabrication of two polyimide-based (PI-based) monoliths (pure PI monolith and hybrid PI monolith) with a hierarchically porous structure that ...avoids the shortcomings of traditional methods. In this case, the thermally induced phase separation (TIPS) method was used to prepare polyamic acid (PAA) monoliths for the first time, then PI-based monoliths were fabricated by thermal imidization. Through the introduction of octakis(glycidyldimethylsiloxy)octasilsesquioxane into the PAA prepared from 4,4′-oxydianiline and pyromellitic dianhydride, both the hydrophobicity and mechanical strengths of the PI-based monoliths were improved. Moreover, the resulting PI-based monoliths exhibited suitable permeability, homogeneous morphologies, and superior thermal stability. Adsorption tests demonstrated that the resulting hybrid PI monoliths exhibited better adsorption performance for organic solvents and silicone oil than the pure PI monolith. Furthermore, the surface of a polyhedral oligomeric silsesquioxane (POSS) hybridized PI (PI-
co
-POSS) monolith can be modified into a hydrophilic layer by reaction between the hydrophilic polymer and epoxy groups exposed on the surface. This indicates that PI-
co
-POSS monoliths have potential in liquid diode application to achieve oil-water separation.
Thermally induced phase separation (TIPS) and thermal imidization were used to prepare PI-based monoliths in sequence. The hybridized PI (PI-
co
-POSS) monoliths exhibit potential in liquid diode application to achieve oil-water separation.
Metal oxide affinity chromatography (MOAC) is considered to be one of the most effective methods for phosphopeptide enrichment. However, most of the materials used in the method are powder; frequent ...centrifugation is necessitated during the enrichment process, and potential risks of loss of peptides and materials and clogging of the column employed for liquid chromatography–mass spectrometry (LC–MS) arise. Moreover, the reusability of these materials to achieve sustainability was hardly investigated. To overcome these limitations, herein, inorganic titanium dioxide (TiO2) was coated onto the skeletal surface of the organic cellulose monolith (CM) material with a coral-like structure via a sol–gel method. This produced an organic–inorganic hybrid TiO2-CM material, which contained a combination of organic and inorganic substances, making it mimic the mollusk shell in terms of composition. The prepared TiO2-CM material as monolith exhibited excellent mechanical strength and did not break during the enrichment process; thus, the tedious implementation of multiple centrifugation cycles was prevented, thereby streamlining the experimental procedure and avoiding the loss of peptides and materials. Moreover, a large amount of TiO2 was introduced onto the surface of the CM material, and thus, the resultant TiO2-CM material exhibited a large surface area. As a result, the fabricated TiO2-CM material was successfully applied to the enrichment of phosphopeptides obtained from the tryptic digests of a BSA/β-casein (mass ratio, 500/1) mixture. The results were superior to those achieved for commercial TiO2 beads, confirming that TiO2-CM has excellent selectivity for phosphopeptides and reusability. Furthermore, 9287 unique phosphopeptides derived from the 2661 phosphoproteins were successfully identified from two milligrams of tryptic digests of Hela cell exosomes obtained through five independent replications after enriching using the TiO2-CM material. The results indicated that the material has good application prospects in the analysis of protein phosphorylation. Furthermore, TiO2-CM consists of green and cheap cellulose as the skeleton, and its synthesis process is environment-friendly, simple, and inexpensive.
This study evaluated the effects of carbon ion and X-ray radiation and the tumor microenvironment on the migration of glioma and endothelial cells, a key process in tumorigenesis and angiogenesis ...during cancer progression. C6 glioma and human microvascular endothelial cells were treated with conditioned medium from cultures of glioma cells irradiated at a range of doses and the migration of both cell types, tube formation by endothelial cells, as well as the expression and secretion of migration-related proteins were evaluated. Exposure to X-ray radiation-conditioned medium induced dose-dependent increases in cell migration and tube formation, which were accompanied by an upregulation of vascular endothelial growth factor (VEGF) and matrix metalloproteinase (MMP)-2 and -9 expression. However, glioma cells treated with conditioned medium of cells irradiated at a carbon ion dose of 4.0 Gy showed a marked decrease in migratory potential and VEGF secretion relative to non-irradiated cells. The application of recombinant VEGF165 stimulated migration in glioma and endothelial cells, which was associated with increased FAK phosphorylation at Tyr861, suggesting that the suppression of cell migration by carbon ion radiation could be via VEGF-activated FAK signaling. Taken together, these findings indicate that carbon ion may be superior to X-ray radiation for inhibiting tumorigenesis and angiogenesis through modulation of VEGF level in the glioma microenvironment.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Background: The pathogenesis of the development of IgA nephropathy has not been clear up to now. At present, some studies revealed that the mTOR pathway may participate in IgA nephropathy; however, ...the mechanism has not been systematically studied. In this study, we established an IgAN rat model to investigate the protective effects of rapamycin as a new type of immunosuppressant, as well as its therapeutic mechanisms.
Methods: After the establishment of IgA nephropathy model, rats were treated with different concentrations of rapamycin, and the protective effect of different concentrations of rapamycin on renal function of the rats was observed. The deposition of IgA was observed by immunofluorescence. The kidney expression of Akt and p70S6k proteins in mTOR pathway was examined using the western blot assay after rapamycin treatment.
Results: Morphology and immunofluorescence confirmed that the rat model of IgA nephropathy was successfully established. In particular, the level of proteinuria decreased with the increase of the dose of rapamycin, as well as the deposition of IgA in glomeruli. Moreover, the western blot analysis indicated that the expression of p70S6K in the downstream of mTOR pathway decreased and the upstream protein AKT of the mTOR pathway was overexpressed in the rats model.
Conclusion: We found that rapamycin has protective effects in the IgA nephropathy rat model in a dose-dependent manner. In addition, the result of western blot assay suggested that rapamycin may display its therapeutic effects through interfering the AKT-mTOR-p70S6K signaling pathway.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Introduction: Impaired cardiac function is one of the most concomitant symptoms in patients with kidney failure after long-term dialysis. In addition, the preservation of adequate perfusion pressure ...to the graft plays a significant role in the intraoperative management during kidney transplantation, but the use of positive inotropic drugs in kidney transplant patients has been studied less. We investigated the protective effects of renal function by means of cardiac inotropes in kidney transplant patients. Methods: Eighty-nine patients that received kidney transplantation between April 2014 and December 2016 at Qilu Hospital were included and randomly divided into the treatment group receiving levosimendan and a control group. All kidney recipients received ABO-compatible donors. A poor outcome was defined as one of the following: delayed graft function, graft hemorrhage, or nephrectomy. Results: The treatment group had a better composite outcome and the level of neutrophil gelatinase-associated lipocalin was also lower than in the control group. Conclusion: Inotropic drugs may play a protective role in renal function in kidney transplantation.
The pinhole model utilized in most computer vision algorithms becomes unfeasible because of lens distortion. Thus it is a must to compensate lens distortion to make the pinhole model available. In ...this paper, we propose a new robust line-based distortion estimation method to correct radial distortion. Our method works from a single image and is able to estimate the distortion center rather than assuming it is at the image center. Distortion parameters are estimated from parameters of circulars arcs, on the basis that straight lines are imaged as circular arcs under one-parameter division model. A new feature selection scheme by refining circular arcs is introduced to make the process of distortion estimation fully automatic and more robust. Moreover, a linear optimization algorithm is applied to calculating parameters in each selection run, making our feature selection scheme more efficient. Experiments on synthetic images and real images show that our method performs well in radial distortion estimation even with severely distorted images.
To reveal the expression and possible role of tribbles homolog 3 (TRB3) in the incidence of type 2 diabetic nephropathy, we used immunohistochemistry, real-time quantitative PCR, western blot ...analysis, and enzyme-linked immunosorbent assay (ELISA) to study the expression of TRB3, extracellular signal-regulated kinase 1/2 mitogen-activated protein kinase (ERK1/2 MAPK), transforming growth factor β1 (TGF-β1), and collagen type IV in kidneys of db/db diabetic mice and in murine renal mesangial cells stimulated with high glucose. The expression of TRB3, TGF-β1, and collagen type IV was increased in kidneys of db/db diabetic mice. TGF-β1 and collagen type IV regulated by high glucose through ERK1/2 MAPK were downregulated by silencing TRB3 in renal mesangial cells. TRB3 may be involved in diabetic nephropathy by regulating the fibrosis cytokine TGF-β1 and collagen type IV through the ERK1/2 MAPK signaling pathway.
Two-dimensional (2D) materials are widely used as key components in the fields of energy conversion and storage, optoelectronics, catalysis, biomedicine,
etc.
To meet the practical needs, molecular ...structure design and aggregation process optimization have been systematically carried out. The intrinsic correlation between preparation methods and the characteristic properties is investigated. This review summarizes the recent research achievements of 2D materials in the aspect of molecular structure modification, aggregation regulation, characteristic properties, and device applications. The design strategies to fabricate functional 2D materials starting from precursor molecules are introduced in detail referring to organic synthetic chemistry and self-assembly technology. It provides important research ideas for the design and synthesis of related materials.
The advances in two-dimensional materials are summarized from a viewpoint of the correlation between the preparation strategy and exhibited properties.
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