134 research outputs found
Shortcuts to Adiabaticity with Inherent Robustness and without Auxiliary Control
Shortcuts to adiabaticity (STA) are fast methods to realize the same final
state evolution of quantum adiabatic process. We develop a general theory to
construct a new kind of STA by solely sampling the points of the adiabatic path
of the original adiabatic Hamiltonian. In contrast to previous methods, our
approach does not require any additional control resources, has inherent
robustness, and does not use any complicated unitary transformation. Based on
path sampling, the resulting STA protocols are simple and can avoid points of
adiabatic path that are challenging to implement. As applications of our
theory, we demonstrate reduction of the effects of both dissipation and
dephasing noise by a novel robust three-level control, as well as reliable and
fast ground state evolution in an adiabatic quantum computing model. Our theory
offers a new route to design robust and fast control methods for general
quantum systems
Adhesion of bio-functionalized ultrasound microbubbles to endothelial cells by targeting to vascular cell adhesion molecule-1 under shear flow
The expression of certain endothelial cell adhesion molecules is increased during endothelial dysfunction or inflammatory activation. This has led to the concept of using microbubbles for targeted molecular imaging or drug delivery. In this approach, microbubbles with a specific ligand to receptors expressed at the site of specific diseases are constructed. The present study aimed to engineer a novel type of bio-functionalized microbubbles (vascular cell adhesion molecule 1 [VCAM-1]-targeted microbubbles), and determine whether VCAM-1-targeted microbubbles exhibit specific adhesion to lipopolysaccharide (LPS)-activated endothelial cells. Our data showed that VCAM-1 expression was significantly upregulated in both LPS-activated endothelial cells in vitro and endothelium in a rat atherosclerosis model in vivo. Targeted microbubbles were designed by conjugating anti-VCAM-1 monoclonal antibodies to the shell of microbubbles using biotin–avidin bridging chemistry methods. Microbubble adhesion to endothelial cells was assessed in a flow chamber at two shear stress conditions ( 6.3 and 10.4 dynes/cm2). Our data showed that microbubble adhesion depends on both the surface anti-VCAM-1 antibody densities and the exposed shear stresses. Adhesion of VCAM-1-targeted microbubbles onto LPS-activated endothelial cells increased with the surface antibody densities, and decreased with the exposed shear stresses. These findings showed that the specific ligand-carrying microbubbles have considerable potential in targeted ultrasound molecular imaging or ultrasound-assisted drug/gene delivery applications
Investigation of folate-conjugated fluorescent silica nanoparticles for targeting delivery to folate receptor-positive tumors and their internalization mechanism
Multifunctionalized nanoparticles (NPs) are emerging as ideal tools for gene/drug delivery, bioimaging, labeling, or intracellular tracking in biomedical applications, and have attracted considerable attention owing to their unique advantages. In this study, fluorescent silica NPs were synthesized by a modified Stöber method using conjugates of 3-mercaptopropyltrimethoxysilane (MPS) and maleimide-fluorescein isothiocyanate (maleimide-FITC). Mean diameters of the NPs were controlled between 212–2111 nm by regulating MPS concentration in the reaction mixture. Maleimide-FITC molecules were doped into NPs or conjugated to the surface of NPs through the chemical reaction of maleimide and thiol groups. The data showed that the former NPs are better than the latter by comparing their fluorescence intensity. Furthermore, folate molecules were linked to the FITC-doped silica NPs by using polyethylene glycol (PEG) (NH2-PEG-maleimide) as a spacer, thus forming folate receptor targeting fluorescent NPs, referred to as NPs(FITC)-PEG-Folate. The quantitative analysis of cellular internalization into different cancer cells showed that the delivery efficiency of KB cells (folate receptor-positive cells) is more than six-fold higher than that of A549 cells (folate receptor-negative cells). The delivery efficiency of KB cells decreased significantly after free folate addition to the cell culture medium because the folate receptors were occupied by the free folate. The NPs endocytosis mechanism was also investigated. It was shown that clathrin, an inhibitor of cell phagocytosis, markedly decreased the NPs uptake into KB cells, suggesting that it plays an important role in NPs cellular internalization. These results demonstrated that the novel particles of NPs(FITC)-PEG-Folate are promising for fluorescent imaging or targeting delivery to folate receptor-positive tumors
Experimental analysis and research on the effect of long-term vibration on the performance of vehicle carbon canisters
The long-term vibration of the carbon canister during vehicle operation can lead to changes in its performance, thereby affecting its performance on evaporation emissions. A vibration test bench simulating vehicle vibration characteristics is used to simulate the working state of the carbon canister under actual driving conditions, analyze the amount of carbon powder precipitation and flow resistance changes in the canister after long-term operation, and compare the adsorption and desorption performance of the canister before and after aging and their effect on the evaporative emissions. The results showed that the carbon canister will produce carbon powder precipitation after being continuously subjected to the forward and backward vibration of the vehicle. This leads to a decrease in the ultimate adsorption and desorption capacity of the aged carbon canister for fuel vapor, with a more significant decrease in adsorption capacity. However, in the 2-day Diurnal Breathing Loss(DBL) test, due to the increase in flow resistance of the aged carbon canister, it is more difficult for the adsorbed fuel vapor to diffuse outward. For the unsaturated carbon canister, fuel leakage and evaporative emissions can be reduced. In evaporative emission management, it is necessary to adjust the control strategy reasonably based on the working status of the carbon canister
The Roles of Platelet GPIIb/IIIa and αvβ3 Integrins during HeLa Cells Adhesion, Migration, and Invasion to Monolayer Endothelium under Static and Dynamic Shear Flow
During their passage through the circulatory system, tumor cells undergo extensive interactions with various host cells including endothelial cells and platelets. Mechanisms mediating tumor cell adhesion, migration, and metastasis to vessel wall under flow condition are largely unknown. The aim of this study was to investigate the potential roles of GPIIb/IIIa and αvβ3 integrins underlying the HeLa-endothelium interaction in static and dynamic flow conditions. HeLa cell migration and invasion were studied by using Millicell cell culture insert system. The numbers of transmigrated or invaded HeLa cells significantly increased by thrombin-activated platelets and reduced by eptifibatide, a platelet inhibitor. Meanwhile, RGDWE peptides, a specific inhibitor of αvβ3 integrin, also inhibited HeLa cell transmigration. Interestingly, the presence of endothelial cells had significant effect on HeLa cell migration regardless of static or cocultured flow condition. The adhesion capability of HeLa cells to endothelial monolayer was also significantly affected by GPIIb/IIIa and αvβ3 integrins. The arrested HeLa cells increased nearly 5-fold in the presence of thrombin-activated platelets at shear stress condition (1.84 dyn/cm2 exposure for 1 hour) than the control (static). Our findings showed that GPIIb/IIIa and αvβ3 integrins are important mediators in the pathology of cervical cancer and provide a molecular basis for the future therapy, and the efficient antitumor benefit should target multiple receptors on tumor cells and platelets
The Underpricing of Venture Capital Backed IPOs in China
This paper measures the influence of venture capital (VC) on IPO valuations in China. It is found that the authentication effect is dominated by the grandstanding effect, suggesting that VC firms in China greatly value their reputations. It is also shown that the market-specific characteristics of non-VC-backed firms are more closely related to their initial returns, compared to those of VC-backed firms. In addition, corporate fundamentals play a more important role in the valuation for VC-backed firms than for non-VC-backed firms
The Underpricing of Venture Capital Backed IPOs in China
This paper measures the influence of venture capital (VC) on IPO valuations in China. It is found that the authentication effect is dominated by the grandstanding effect, suggesting that VC firms in China greatly value their reputations. It is also shown that the market-specific characteristics of non-VC-backed firms are more closely related to their initial returns, compared to those of VC-backed firms. In addition, corporate fundamentals play a more important role in the valuation for VC-backed firms than for non-VC-backed firms
Aspirin suppresses chemoresistance and enhances antitumor activity of 5-Fu in 5-Fu-resistant colorectal cancer by abolishing 5-Fu-induced NF-κB activation.
Chemoresistance to 5-fluorouracil (5-Fu)-based chemotherapy is a leading obstacle in achieving effective treatment for colorectal cancer (CRC). Typically, NF-κB activation induced by the chemotherapeutics themselves is an important cause resulting in chemoresistance. Specifically, NF-κB activation can inhibit tumor cell apoptosis and induce chemoresistance. Drugs that can prevent NF-κB activation induced by chemotherapeutics are urgently needed to overcome chemoresistance. Obviously, aspirin is one of these agents, which has been demonstrated to possess antitumor activities and as an inhibitor of NF-κB. The current study aimed to investigate whether aspirin was able to overcome the chemoresistance to 5-Fu in CRC, together with the potential synergistic mechanisms. Our results suggested that aspirin remarkably potentiated the inhibitory effect of 5-Fu on the growth and invasion of resistant cells in vitro. In vivo, aspirin markedly enhanced the antitumor activity of 5-Fu in suppressing tumor growth and metastasis, and down-regulating the expression of NF-κB-regulated genes in the 5-Fu-resistant cells. Obviously, aspirin completely eradicated the 5-Fu-induced NF-κB activation, without inducing pronounced adverse effects. Taken together, findings in this study suggest that aspirin can reverse chemoresistance and potentiate the antitumor effect of 5-Fu, which is achieved through abolishing the 5-Fu-induced NF-κB activation, suggesting that aspirin may be a promising adjuvant therapeutic agent for CRC
Identification of therapeutic targets for osteosarcoma by integrating single-cell RNA sequencing and network pharmacology
Background: Osteosarcoma (OS) is a common primary tumor with extensive heterogeneity. In this study, we used single-cell RNA sequencing (scRNA-seq) and network pharmacology to analyze effective targets for Osteosarcoma treatment.Methods: The cell heterogeneity of the Osteosarcoma single-cell dataset GSE162454 was analyzed using the Seurat package. The bulk-RNA transcriptome dataset GSE36001 was downloaded and analyzed using the CIBERSORT algorithm. The key targets for OS therapy were determined using Pearson’s correlation analysis. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed on key targets. The DeepDR algorithm was used to predict potential drugs for Osteosarcoma treatment. Molecular docking analysis was performed to verify the binding abilities of the predicted drugs and key targets. qRT-PCR assay was used to detect the expression of key targets in osteoblasts and OS cells.Results: A total of 21 cell clusters were obtained based on the GSE162454 dataset, which were labeled as eight cell types by marker gene tagging. Four cell types (B cells, cancer-associated fibroblasts (CAFs), endothelial cells, and plasmocytes) were identified in Osteosarcoma and normal tissues, based on differences in cell abundance. In total, 17 key targets were identified by Pearson’s correlation analysis. GO and KEGG analysis showed that these 17 genes were associated with immune regulation pathways. Molecular docking analysis showed that RUNX2, OMD, and CD4 all bound well to vincristine, dexamethasone, and vinblastine. The expression of CD4, OMD, and JUN was decreased in Osteosarcoma cells compared with osteoblasts, whereas RUNX2 and COL9A3 expression was increased.Conclusion: We identified five key targets (CD4, RUNX2, OMD, COL9A3, and JUN) that are associated with Osteosarcoma progression. Vincristine, dexamethasone, and vinblastine may form a promising drug–target pair with RUNX2, OMD, and CD4 for Osteosarcoma treatment
Neuroinflammation of traumatic brain injury: Roles of extracellular vesicles
Traumatic brain injury (TBI) is a major cause of neurological disorder or death, with a heavy burden on individuals and families. While sustained primary insult leads to damage, subsequent secondary events are considered key pathophysiological characteristics post-TBI, and the inflammatory response is a prominent contributor to the secondary cascade. Neuroinflammation is a multifaceted physiological response and exerts both positive and negative effects on TBI. Extracellular vesicles (EVs), as messengers for intercellular communication, are involved in biological and pathological processes in central nervous system (CNS) diseases and injuries. The number and characteristics of EVs and their cargo in the CNS and peripheral circulation undergo tremendous changes in response to TBI, and these EVs regulate neuroinflammatory reactions by activating prominent receptors on receptor cells or delivering pro- or anti-inflammatory cargo to receptor cells. The purpose of this review is to discuss the possible neuroinflammatory mechanisms of EVs and loading in the context of TBI. Furthermore, we summarize the potential role of diverse types of cell-derived EVs in inflammation following TBI
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