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The water diversion project is an effective engineering approach to overcome water scarcity as a water source for the area. However, the complex environmental conditions of long-distance water diversion bring many uncertainties for water security. In this study, we assessed the pollution condition and risk levels of emerging contaminants and traditional contaminants in the water and soil along a water diversion project in Tianjin. Then, we assessed the influence of eco-economic characteristics on environmental conditions and established a comprehensive assessment framework of water source sustainability by analytic hierarchy process (AHP). The results showed that excessive nutrient elements and heavy metal pollution mainly contributed to environmental problems in the water source area. Contrary to pollution assessment, the soil ecosystem was more subject to environmental pressure due to atmospheric deposition. The health risk assessment indicated that all contaminants had negligible non-carcinogenic risks for adults, with arsenic being considered a priority pollutant. The statistical analysis results indicated land use allocation was the most important factor in the environmental management of the water source area. According to the result of the integrated environmental assessment, the main characteristics of pressure zones were high pollution levels and human activity intensity. It is urgent to control agricultural pollution and allocate land use rationally for water source pressure zones. By considering the risks of traditional and emerging contaminants in water and soil, this study could support urban water source management and the sustainable development of the water diversion project.
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Non-destructive measurements of low-intensity charged particle beams are particularly challenging for beam diagnostics. At the Heavy Ion Accelerator Facility in Lanzhou (HIRFL), beams with weak currents below 1 µA are often provided for experiments. The detection of such low beam current is below the threshold of typical standard beam current transformers. Therefore, a low-intensity monitoring system is developed by using a sensitive capacitive pick-up (PU) and low-noise electronics. This device measures beam currents by digitally analyzing the amplitude of the PU signals using a homodyne detection scheme. During lab tests, the amplitude nonlinearity is <0.5% in the operational range of 1 nA-45 µA and the amplitude resolution is 0.94 nA. At present, four measurement systems for low beam currents are installed at HIRFL for the monitoring of standard operating conditions with low beam currents below 1 µA. After an absolute calibration with a Faraday cup, it can be used for accurate beam intensity measurement with a current resolution of about 1 nA.
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Objectives: The goal of this study was to explore the reliability and clinical value of fast, accurate automatic segmentation of the aortic root based on a deep learning tool compared with computed tomography angiography. Methods: A deep learning tool for automatic 3-dimensional aortic root reconstruction, the CVPILOT system (TAVIMercy Data Technology Ltd., Nanjing, China), was trained and tested using computed tomography angiography scans collected from 183 patients undergoing transcatheter aortic valve replacement from January 2021 to December 2022. The quality of the reconstructed models was assessed using validation data sets and evaluated clinically by experts. Results: The segmentation of the ascending aorta and the left ventricle attained Dice similarity coefficients (DSC) of 0.9806/0.9711 and 0.9603/0.9643 for the training and validation sets, respectively. The leaflets had a DSC of 0.8049/0.7931, and the calcification had a DSC of 0.8814/0.8630. After 6 months of application, the system modeling time was reduced to 19.83 s. Conclusion: For patients undergoing transcatheter aortic valve replacement, the CVPILOT system facilitates clinical workflow. The reliable evaluation quality of the platform indicates broad clinical application prospects in the future.
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Despite the tremendous clinical potential of nucleic acid-based vaccines, their efficacy to induce therapeutic immune response has been limited by the lack of efficient local gene delivery techniques in the human body. In this study, we develop a hydrogel-based organic electronic device (µEPO) for both transdermal delivery of nucleic acids and in vivo microarrayed cell electroporation, which is specifically oriented toward one-step transfection of DNAs in subcutaneous antigen-presenting cells (APCs) for cancer immunotherapy. The µEPO device contains an array of microneedle-shaped electrodes with pre-encapsulated dry DNAs. Upon a pressurized contact with skin tissue, the electrodes are rehydrated, electrically triggered to release DNAs, and then electroporate nearby cells, which can achieve in vivo transfection of more than 50% of the cells in the epidermal and upper dermal layer. As a proof-of-concept, the µEPO technique is employed to facilitate transdermal delivery of neoantigen genes to activate antigen-specific immune response for enhanced cancer immunotherapy based on a DNA vaccination strategy. In an ovalbumin (OVA) cancer vaccine model, we show that high-efficiency transdermal transfection of APCs with OVA-DNAs induces robust cellular and humoral immune responses, including antigen presentation and generation of IFN-γ+ cytotoxic T lymphocytes with a more than 10-fold dose sparing over existing intramuscular injection (IM) approach, and effectively inhibits tumor growth in rodent animals.
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Electroporación , Inmunoterapia , Vacunas de ADN , Animales , Vacunas de ADN/administración & dosificación , Vacunas de ADN/inmunología , Electroporación/métodos , Ratones , Inmunoterapia/métodos , Administración Cutánea , Neoplasias/terapia , Neoplasias/inmunología , Vacunas contra el Cáncer/inmunología , Vacunas contra el Cáncer/administración & dosificación , Ovalbúmina/inmunología , Ovalbúmina/administración & dosificación , Células Presentadoras de Antígenos/inmunología , Femenino , Ratones Endogámicos C57BL , Humanos , Vacunación/métodosRESUMEN
Spliceosomal small nuclear RNAs (snRNAs) are a fundamental class of non-coding small RNAs abundant in the nucleoplasm of eukaryotic cells, playing a crucial role in splicing precursor messenger RNAs (pre-mRNAs). They are transcribed by DNA-dependent RNA polymerase II (Pol II) or III (Pol III), and undergo subsequent processing and 3' end cleavage to become mature snRNAs. Numerous protein factors are involved in the transcription initiation, elongation, termination, splicing, cellular localization, and terminal modification processes of snRNAs. The transcription and processing of snRNAs are regulated spatiotemporally by various mechanisms, and the homeostatic balance of snRNAs within cells is of great significance for the growth and development of organisms. snRNAs assemble with specific accessory proteins to form small nuclear ribonucleoprotein particles (snRNPs) that are the basal components of spliceosomes responsible for pre-mRNA maturation. This article provides an overview of the biological functions, biosynthesis, terminal structure, and tissue-specific regulation of snRNAs.
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Precursores del ARN , ARN Nuclear Pequeño , Empalmosomas , Empalmosomas/metabolismo , Empalmosomas/genética , Precursores del ARN/metabolismo , Precursores del ARN/genética , ARN Nuclear Pequeño/genética , ARN Nuclear Pequeño/metabolismo , Humanos , Núcleo Celular/metabolismo , Núcleo Celular/genética , Animales , Empalme del ARN , Procesamiento Postranscripcional del ARNRESUMEN
Cancer cells generally exhibit 'iron addiction' phenotypes, which contribute to their vulnerability to ferroptosis inducers. Ferroptosis is a newly discovered form of programmed cell death caused by iron-dependent lipid peroxidation. In the present study, pacidusin B, a dichapetalin-type triterpenoid from Phyllanthus acidus (L.) Skeels (Euphorbiaceae), induces ferroptosis in the HT1080 human fibrosarcoma cell line. Cells treated with pacidusin B exhibited the morphological characteristic 'ballooning' phenotype of ferroptosis. The biochemical hallmarks of ferroptosis were also observed in pacidusin B-treated cells. Both oxidative stress and ER stress play significant roles in pacidusin B-induced ferroptosis. The activation of the PERK-Nrf2-HO-1 signaling pathway led to iron overload, while inhibition of GPX4 further sensitized cancer cells to ferroptosis. Furthermore, the molecular docking study showed that pacidusin B docked in the same pocket in xCT as the ferroptosis inducer erastin. These results revealed that pacidusin B exerts anticancer effects via inducing ER-mediated ferroptotic cell death.
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BACKGROUND: Plasma cell-free DNA (cfDNA) fragmentomics has demonstrated significant differentiation power between cancer patients and healthy individuals, but little is known in pancreatic and biliary tract cancers. The aim of this study is to characterize the cfDNA fragmentomics in biliopancreatic cancers and develop an accurate method for cancer detection. METHODS: One hundred forty-seven patients with biliopancreatic cancers and 71 non-cancer volunteers were enrolled, including 55 patients with cholangiocarcinoma, 30 with gallbladder cancer, and 62 with pancreatic cancer. Low-coverage whole-genome sequencing (median coverage: 2.9 ×) was performed on plasma cfDNA. Three cfDNA fragmentomic features, including fragment size, end motif and nucleosome footprint, were subjected to construct a stacked machine learning model for cancer detection. Integration of carbohydrate antigen 19-9 (CA19-9) was explored to improve model performance. RESULTS: The stacked model presented robust performance for cancer detection (area under curve (AUC) of 0.978 in the training cohort, and AUC of 0.941 in the validation cohort), and remained consistent even when using extremely low-coverage sequencing depth of 0.5 × (AUC: 0.905). Besides, our method could also help differentiate biliopancreatic cancer subtypes. By integrating the stacked model and CA19-9 to generate the final detection model, a high accuracy in distinguishing biliopancreatic cancers from non-cancer samples with an AUC of 0.995 was achieved. CONCLUSIONS: Our model demonstrated ultrasensitivity of plasma cfDNA fragementomics in detecting biliopancreatic cancers, fulfilling the unmet accuracy of widely-used serum biomarker CA19-9, and provided an affordable way for accurate noninvasive biliopancreatic cancer screening in clinical practice.
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Neoplasias del Sistema Biliar , Ácidos Nucleicos Libres de Células , Neoplasias Pancreáticas , Humanos , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/diagnóstico , Neoplasias Pancreáticas/sangre , Neoplasias del Sistema Biliar/genética , Neoplasias del Sistema Biliar/diagnóstico , Neoplasias del Sistema Biliar/sangre , Masculino , Femenino , Persona de Mediana Edad , Anciano , Biomarcadores de Tumor/sangre , AdultoRESUMEN
OBJECTIVE: In this case report, the auxiliary role of deep learning and 3-dimensional printing technology in the perioperative period was discussed to guide transcatheter aortic valve replacement and coronary stent implantation simultaneously. CASE PRESENTATION: A 68-year-old man had shortness of breath and chest tightness, accompanied by paroxysmal nocturnal dyspnea, 2 weeks before presenting at our hospital. Echocardiography results obtained in the outpatient department showed severe aortic stenosis combined with regurgitation and pleural effusion. The patient was first treated with closed thoracic drainage. After 800 mL of pleural effusion was collected, the patient's symptoms were relieved and he was admitted to the hospital. Preoperative transthoracic echocardiography showed severe bicuspid aortic valve stenosis combined with calcification and aortic regurgitation (mean pressure gradient, 42 mmHg). Preoperative computed tomography results showed a type I bicuspid aortic valve with severe eccentric calcification. The leaflet could be seen from the left coronary artery plane, which indicated an extremely high possibility of coronary obstruction. After preoperative imaging assessment, deep learning and 3-dimensional printing technology were used for evaluation and simulation. Guided transcatheter aortic valve replacement and a coronary stent implant were completed successfully. Postoperative digital subtraction angiography showed that the bioprosthesis and the chimney coronary stent were in ideal positions. Transesophageal echocardiography showed normal morphology without paravalvular regurgitation. CONCLUSION: The perioperative guidance of deep learning and 3-dimensional printing are of great help for surgical strategy formulation in patients with severe bicuspid aortic valve stenosis with calcification and high-risk coronary obstruction.
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Estenosis de la Válvula Aórtica , Aprendizaje Profundo , Impresión Tridimensional , Reemplazo de la Válvula Aórtica Transcatéter , Humanos , Reemplazo de la Válvula Aórtica Transcatéter/métodos , Masculino , Anciano , Estenosis de la Válvula Aórtica/cirugía , Estenosis de la Válvula Aórtica/diagnóstico por imagen , Stents , Válvula Aórtica/cirugía , Válvula Aórtica/diagnóstico por imagen , Válvula Aórtica/anomalías , Insuficiencia de la Válvula Aórtica/cirugía , Insuficiencia de la Válvula Aórtica/diagnóstico por imagenRESUMEN
BACKGROUND: Functional tricuspid regurgitation (FTR) following left-sided valve surgery (LSVS) is of clinical significance due to its high recurrence and mortality rates. Transcatheter therapy presents a potential solution to address this issue. AIMS: The study aimed to assess the safety and efficacy of transcatheter tricuspid valve replacement using the Lux-Valve system in a single center for patients with FTR after LSVS. METHODS: From June 2020 to April 2023, 20 patients with symptomatic severe FTR after LSVS were referred to our center. A multidisciplinary cardiac team evaluated these patients for suitability for transcatheter tricuspid valve replacement with Lux-Valve systems. Primary efficacy and safety endpoints were immediate postoperative tricuspid regurgitation severity ≤ moderate and major adverse events during follow-up. RESULTS: Twenty patients (average age 65.7 ± 7.4 years; 65.0% women) successfully underwent Lux-Valve system implantation after LSVS. All patients achieved ≤ moderate tricuspid regurgitation immediately after the procedure. Only one patient (5.0%) experienced a procedure-related major adverse event, leading to in-hospital mortality due to pulmonary infection. At the 6-month follow-up, 17 patients (89.5%) improved to New York Heart Association functional class I to II (p < 0.001). The overall Kansas City Cardiomyopathy Questionnaire score significantly improved (35.9 ± 6.7 points to 58.9 ± 5.8 points, p < 0.001). CONCLUSION: The Lux-Valve system was found to be safe and effective for treating FTR after LSVS. It resulted in positive early outcomes, including a significant reduction in FTR, improved functional status, and enhanced quality of life, especially in high-risk patients.
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Implantación de Prótesis de Válvulas Cardíacas , Insuficiencia de la Válvula Tricúspide , Humanos , Femenino , Persona de Mediana Edad , Anciano , Masculino , Insuficiencia de la Válvula Tricúspide/diagnóstico por imagen , Insuficiencia de la Válvula Tricúspide/cirugía , Válvula Tricúspide/diagnóstico por imagen , Válvula Tricúspide/cirugía , Calidad de Vida , Resultado del Tratamiento , Cateterismo Cardíaco/métodosRESUMEN
In this paper, a new 0.15-2 GHz broadband phase shifter with 9-bit phase resolution is presented. This broadband digital adjustable phase shifter is implemented by utilizing the signal vector summation technology. The phase shifter consists of one 90° hybrid coupler, two digital attenuators, two 180° hybrid couplers, two microwave switches, and one combiner. By adjusting the attenuation value of the two digital attenuators, the device creates a minimum 0.7° stepped phase shift. In addition, by switching the two microwave switches, a 360° range of phase shift is achieved while almost keeping the amplitude of the phase shifter constant. The measurement results show that the proposed phase shifter achieves a phase resolution of 0.7° while exhibiting an average insertion loss of 9 ± 2 dB and phase unbalance within ±10°. The calculated RMS phase error of the broadband phase shifter is below 5° from 0.15 to 2 GHz.
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Background: CTNNB1 mutates in most hepatocellular carcinoma (HCC) which is the most familiar form of liver cancer with high heterogeneity. It is critical to create a specific prognostication methodology and to investigate additional treatment options for CTNNB1-mutant HCCs. Methods: A total of 926 samples in five independent cohorts were enrolled in this study, including 127 CTNNB1-mutant samples and 75 estimated CTNNB1-mutant samples. The prognostic signature was constructed by LASSO-Cox regression and evaluated by bioinformatics analyses. The selection of possible drug targets and agents was produced based on the expression profiles and drug sensitivity data of cancer cell lines in two databases. Results: A prognostic signature based on 15 genes categorized the CTNNB1-mutant HCCs into two groups with different risks. Compared to low-risk patients, high-risk patients had significantly inferior prognoses. ROC curve and multivariate analysis also indicated the superior performance of our signature on the prognosis estimation, particularly in CTNNB1-mutant HCCs. Besides, the nomogram was constructed according to the prognostic signature with excellent predictive performance confirmed by the calibration curve. Subsequently, we suggested that AT-7519 and PHA-793887 might be potential drug agents for high-risk patients. Conclusion: We established a 15-gene prognostic model, particularly in HCCs with CTNNB1 mutations with good predictive efficiency. Besides, we explored the potential drug targets and agents for patients with high risk. Our findings offered a fresh idea for personalized prognosis management in HCCs with CTNNB1 mutations and threw new insight for precise treatment in HCCs as well.
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Platinum-based drugs have revolutionized cancer chemotherapy; however, their therapeutic efficacy has been limited by severe side effects and drug resistance. Recently, approaches that target specific organelles in cancer cells have emerged as attractive alternatives to overcome these challenges. Many studies have validated these strategies and highlighted that organelle-targeted platinum complexes demonstrate increased anticancer activity, the ability to overcome drug resistance, novel molecular mechanisms, or even lower toxicity. This review provides a brief summary of various organelle-targeting strategies that promote the accumulation of platinum complexes in certain intracellular areas, such as the nucleus, mitochondria, endoplasmic reticulum (ER), and lysosomes. Moreover, the mechanisms through which these strategies improve anticancer performance, overcome drug resistance, and alter the action mode of conventional platinum drugs are discussed. By providing an extensive account of platinum complexes targeting different organelles, this review aims to assist researchers in understanding the design principles, identifying potential targets, and fostering innovative ideas for the development of platinum complexes.
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Objective: To evaluate improved identification and the generalization of the RITA-T (Rapid interactive Screening Test for Autism in Toddlers) model through partnerships with Primary Care (PC), Early Intervention (EI), and Autism Diagnosticians. Methods: Over 3 years (2018-2021), 15 EI and 9 PC (MD and NP) centers participated in this project. We trained providers on the RITA-T and established screening models. We reviewed charts of all toddlers referred through this model and compared wait times, and diagnoses, to those evaluated through regular referral in a tertiary-based autism clinic. We also examined the RITA-T psychometrics. Results: 377 toddlers met our inclusion criteria. Wait time for diagnosis was an average of 2.8 months and led to further collaboration between community providers. RITA-T cut-off scores stayed consistent. Providers reported improved confidence and easy integration of this model. Conclusions: This model is generalizable and improves the Early Identification of ASD.
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Dipole magnet vacuum chambers are among the most critical and costly components of rapid-cycling accelerator facilities. Alternative approaches to traditional ceramic chambers have been explored for the implementation of fast-ramping dipole-magnet vacuum chambers, including thin-wall metallic beam pipe chambers strengthened with transverse ribs and ceramic rings inside thin-walled chambers. Here, we report a novel 3D-printed titanium alloy cage inside the thin-wall vacuum chamber, which is designed for high-intensity heavy ion accelerator facility (HIAF) to reduce manufacturing difficulty and cost, shorten the production cycle, and improve the quality. Comprehensive studies were undertaken to characterize the impedance of the 3D-printed titanium alloy cage inside the thin-wall vacuum chamber. The beam-coupling impedance and eddy currents of the new thin-wall vacuum chamber were studied mostly numerically. Strategies for further reducing the beam-coupling impedance were explored. In addition, impedance bench measurements using the "half wavelength" resonant method were conducted to identify the longitudinal and transverse impedances of the 3D-printed titanium alloy cage inside the thin-wall vacuum chamber prototype experimentally. The simulated and measured results for the impedance were consistent. Furthermore, a campaign for resonance-check measurements on the 3D-printed titanium alloy ring loaded inside a thin-wall vacuum chamber prototype was launched. This novel thin-wall vacuum chamber structure is now entering the fabrication stage and will soon be ready for installation in the Booster Ring (BRing).
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OBJECTIVE: To observe the clinical efficacy of intercondylar fossa plasty in preventing intercondylar fossa impingement syndrome after high tibial osteotomy. METHODS: From August 2018 to August 2020, 84 patients with inverted knee osteoarthritis were treated by arthroscopy combined with high tibial osteotomy, and were divided into two groups with 42 cases in each group according to different surgical methods. In the intercondylar fossa plasty group, there were 13 males and 29 females, age ranged from 52 to 67 years old with an average of(58.27±4.32) years old, and arthroscopic intercondylar fossa plasty was performed first, and then high tibial osteotomy. In the arthroscopic cleansing group, 16 males and 26 females, age ranged from 50 to 71 years old with an average of (59.02±5.14) years old, underwent arthroscopic cleansing and then high tibial osteotomy. Postoperative treatment was evaluated using visual analogue scale(VAS), hospital for special surgery (HSS) score for the knee, and the occurrence of intercondylar percussa impingement. RESULTS: All 84 patients were followed up, the duration ranged from 12 to 18 months with an average of (14.1±1.6) months. The VAS and HSS score of knee joint at 6, 12 and 18 months after surgery were significantly improved compared with preoperative period, and there was no significant difference between the two groups (P>0.05), but the incidence of intercondylar fossa index and intercondylar fossa impact between the two groups was significantly compared 18 months after surgery (P<0.05). CONCLUSION: Intercondylar fossa plasty can effectively prevent the incidence of intercondylar fossa impact after high tibial osteotomy, and has a more significant effect on postoperative knee pain and function improvement.
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Osteoartritis de la Rodilla , Tibia , Masculino , Femenino , Humanos , Persona de Mediana Edad , Anciano , Tibia/cirugía , Osteoartritis de la Rodilla/cirugía , Articulación de la Rodilla/cirugía , Resultado del Tratamiento , Osteotomía/métodos , Dolor Postoperatorio , Estudios RetrospectivosRESUMEN
Magnetic particle imaging (MPI) is an emerging non-invasive tomographic technique based on the response of magnetic nanoparticles (MNPs) to oscillating drive fields at the center of a static magnetic gradient. In contrast to magnetic resonance imaging (MRI), which is driven by uniform magnetic fields and projects the anatomic information of the subjects, MPI directly tracks and quantifies MNPs in vivo without background signals. Moreover, it does not require radioactive tracers and has no limitations on imaging depth. This article first introduces the basic principles of MPI and important features of MNPs for imaging sensitivity, spatial resolution, and targeted biodistribution. The latest research aiming to optimize the performance of MPI tracers is reviewed based on their material composition, physical properties, and surface modifications. While the unique advantages of MPI have led to a series of promising biomedical applications, recent development of MPI in investigating vascular abnormalities in cardiovascular and cerebrovascular systems, and cancer are also discussed. Finally, recent progress and challenges in the clinical translation of MPI are discussed to provide possible directions for future research and development.
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Keratin 15 (KRT15) regulates the invasion as well as the stemness and is associated with tumor size and metastasis of several gastrointestinal cancers apart from liver cancer. The present study aimed to explore the effect of KRT15 knockdown on liver cancer malignant behaviors and its interaction with the ß-catenin pathway. Small interfering (si)-KRT15 and si-negative control (NC) were transfected into liver cancer cell lines, followed by the addition or not of CHIR-99021 (a ß-catenin agonist). Cell viability, invasion, apoptosis, and the half maximal inhibitory concentration (IC50) value of doxorubicin (Dox) were then assessed. The present study illustrated that KRT15 gene and protein expression levels were upregulated in most liver cancer cell lines (Huh7, PLC, Hep3B and HepG2) compared to the normal liver cell line THLE-2. si-KRT15 reduced cell viability and invasive cell count while promoting the apoptosis rate in Huh7 and HepG2 cells. In addition, si-KRT15 also reduced the IC50 value of Dox. Furthermore, si-KRT15 inactivated the ß-catenin pathway as reflected by ß-catenin, cyclin D1 and c-Myc expression levels in Huh7 and HepG2 cells. Subsequently, CHIR-99021 treatment increased the cell viability and invasive cell count while reducing the apoptosis rate in Huh7 and HepG2 cells. Concurrently, the IC50 value of Dox was also increased. Notably, CHIR-99021 treatment attenuated the effect of si-KRT15 on mediating the aforementioned Huh7 and HepG2 cell malignant behaviors and Dox chemosensitivity. In conclusion, KRT15 knockdown suppressed viability and mobility but facilitated Dox chemosensitivity via inactivating the ß-catenin pathway in liver cancer, suggesting its potential as a target for liver cancer treatment.
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Stochastic cooling of the high-precision spectrometer ring (SRing) at the High Intensity Heavy-Ion Accelerator Facility (HIAF) project in China, which is used mainly for experiments with radioactive fragment beams, is applied to speed up the cooling process of a stored ion beam. In this article, a new coaxial-type notch filter with an amplitude equalizer in the long branch and an optical-type notch filter with phase-stabilized optical fiber are discussed and evaluated for the SRing stochastic cooling system. Both prototypes of coaxial and optical notch filters are fabricated and tested. The minimum notch depth of coaxial and optical notch filters reaches to 26 and 40 dB, respectively. The performance of both coaxial notch filter and optical fiber notch filter is presented in this work. These developments will be used not only for the longitudinal stochastic cooling system but also have potential for the beam feedback system.
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We developed a marine coating consisting of Cu-MOF-74, multi-walled carbon nanotube containing carboxyl groups (MWCNT-COOH) and self-healing polymers, which simultaneously possesses self-healing and anti-biofouling properties. Cu-MOF-74 can stably release Cu2+ by virtue of the coordination dissociative mechanism. Studies have proved that MWCNT can inhibit the growth of bacteria, so adding the MWCNT can help to reduce the amount of the copper ions and ensure the antibacterial effect of the coating. In addition, the cross-linked network and abundant -COOH provided by the polymers and MWCNT-COOH further prevent the loss of copper ions. Moreover, the coating we prepared has good performance of self-healing at room temperature or slightly heated because the polymers possess abundant non-covalent hydrogen bonds. Finally, the coating not only has superior antibacterial property, but also effectively prevents the adhesion of macrofouling organism. Therefore, the coating has a longer service life and its environmental friendliness has also been improved.
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Cu2O is currently an important protective material for domestic engineering and equipment used to exploit marine resources. Cu+ is considered to have more effective antibacterial and antifouling activities than Cu2+. However, disproportionation of Cu+ in the natural environment leads to its reduced bioavailability and weakened reactivity. Novel and functionalized Cu2O composites could enable efficient and environmentally friendly applications of Cu+. To this end, a series of three-dimensional porous Cu2O nanoparticles (3DNP-Cu2O) functionalized by organic (redox gel, R-Gel)-inorganic (reduced graphene oxide, rGO) hybridsâ3DNP-Cu2O/rGOx@R-Gelâat room temperature by immobilization-reduction method was prepared and applied for protection against marine biofouling. 3DNP-Cu2O/rGO1.76@R-Gel includes rGO and R-Gel shape 3D porous Cu2O nanoparticles with diameters â¼177 nm and strong dispersion and antioxidant stability. Compared with commercial Cu2O (Cu2O-0), 3DNP-Cu2O/rGO1.76@R-Gel exhibited an â¼50% higher bactericidal rate, â¼96.22% higher water content, and â¼75% lower adhesion of mussels and barnacles. Moreover, 3DNP-Cu2O/rGOx@R-Gel maintains the same excellent, stable, and long-lasting bactericidal performance as Cu2O-0@R-Gel while reducing the average copper ion release concentration by â¼56 to 76%. This was also confirmed by X-ray diffraction, X-ray photoelectric spectroscopy (XPS), atomic absorption spectroscopy, and antifouling tests. In addition, XPS tests of rGO-Cu2+ and R-Gel-Cu2+, photocurrent tests of 3DNP-Cu2O/rGO1.76@R-Gel, and energy-dispersive spectrometry pictures of bacteria confirm that R-Gel and rGO act as electron donors and transfer substrates driving the reduction of Cu2+ (Cu2+ â Cu+) and the diffusion of Cu+. Thus, a self-growing antibacterial and antifouling system of 3DNP-Cu2O/rGO1.76@R-Gel was achieved. The mechanism of accelerated bacterial inactivation and resistance to mussel and barnacle adhesion by 3DNP-Cu2O/rGO1.76@R-Gel was interpreted. It is shown that rGO and R-Gel are important players in the antibacterial and antifouling system of 3DNP-Cu2O/rGO1.76@R-Gel.