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To fully exploit pore engineering in the design of more efficient zeolite adsorbents for volatile organic compound (VOC) treatment, the roles of meso- and micropores need to be clarified to provide the theoretical basis and feasible measures. In this work, the three VOC sorption properties of conventional and hierarchical porous beta zeolites were comparatively investigated to study the roles of meso- and micropores. There is a division of functions between micro- and mesopores, with micropores being the main VOC adsorption sites and mesopores greatly enhancing VOC diffusion and adsorbent reusability. On the one hand, micropores should be preserved as much as possible because obtaining mesopores by sacrificing micropores (i.e., alkali treatment) results in 28-60% decreases in adsorption capacities. On the other hand, mesopore introduction is highly desirable, which results in an enhancement of VOC intraparticle diffusion rates by 1.3-2.3 times (at the VOC concentration of 600 ppm) and chlorobenzene adsorption capacity on the 20th cycle increasing from 78% of the initial value to 89 and 93%. The findings may provide valuable information about zeolite-based adsorbents for adsorption removal or recovery of VOCs.
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OBJECTIVE: Metaplastic breast cancer (MpBC) is an aggressive subtype of all breast cancer. We aimed to investigate the clinicopathological features, treatments and prognoses of MpBC patients. METHODS: We collected the data from MpBC patients diagnosed at Tianjin Medical University Cancer Hospital from 2010 to 2017. Kaplan Meier curves and Cox regression model were used to evaluating clinical outcomes and prognostic factors. After removing baseline differences by propensity score matching (PSM), we analyzed the prognosis between MpBC patients and invasive ductal carcinomas of no special type (IDC-NST) patients. RESULTS: A total of 217 MpBC patients were subsumed. Of all histological subtypes, 45.1% were mixed subtypes, followed by with mesenchymal differentiation (27.2%), pure squamous (15.2%) and pure spindle (12.4%) subtypes. 69.6% of MpBC were triple-negative, 25.3% and 6.5% were HR-positive and HER2-positive. MpBC patients had worse survival compared to IDC-NST patients, with 5-year RFS of 73.8 and 83.6% (HR = 1.177 95%CI (1.171-2.676) P = 0.0068), and 5-year BCSS of 79.0% and 89.7% (HR = 2.187 95%CI (1.357-3.523) P = 0.0013). In the multivariate COX model, AJCC stage, mixed subtype and chemotherapy were independent prognostic factors. Mixed MpBC is more aggressive than pure and with heterologous mesenchymal differentiation subtypes. And whether squamous or spindle MpBC, mixed forms have shorter outcomes than pure forms. CONCLUSIONS: MpBCs are associated with poorer prognoses than IDC-NSTs. They are heterogeneous with different clinicopathological features and clinical outcomes between histological subtypes. Pure and with heterologous mesenchymal differentiation subtypes have more survival benefits than the mixed subtype.
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Neoplasias de la Mama , Carcinoma Ductal de Mama , Carcinoma de Células Escamosas , Neoplasias de la Mama Triple Negativas , Humanos , Femenino , Neoplasias de la Mama/patología , Estudios Retrospectivos , Neoplasias de la Mama Triple Negativas/patología , Carcinoma Ductal de Mama/patología , PronósticoRESUMEN
HER2 breast cancer (BC) remains a significant problem in patients with locally advanced or metastatic BC. We investigated the relationship between T helper 1 (Th1) immune response and the proteasomal degradation pathway (PDP), in HER2-sensitive and -resistant cells. HER2 overexpression is partially maintained because E3 ubiquitin ligase Cullin5 (CUL5), which degrades HER2, is frequently mutated or underexpressed, while the client-protective co-chaperones cell division cycle 37 (Cdc37) and heat shock protein 90 (Hsp90) are increased translating to diminished survival. The Th1 cytokine interferon (IFN)-γ caused increased CUL5 expression and marked dissociation of both Cdc37 and Hsp90 from HER2, causing significant surface loss of HER2, diminished growth, and induction of tumor senescence. In HER2-resistant mammary carcinoma, either IFN-γ or Th1-polarizing anti-HER2 vaccination, when administered with anti-HER2 antibodies, demonstrated increased intratumor CUL5 expression, decreased surface HER2, and tumor senescence with significant therapeutic activity. IFN-γ synergized with multiple HER2-targeted agents to decrease surface HER2 expression, resulting in decreased tumor growth. These data suggest a novel function of IFN-γ that regulates HER2 through the PDP pathway and provides an opportunity to impact HER2 responses through anti-tumor immunity.
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Neoplasias de la Mama/tratamiento farmacológico , Proteínas Cullin/genética , Interferón gamma/genética , Receptor ErbB-2/inmunología , Neoplasias de la Mama/genética , Neoplasias de la Mama/inmunología , Neoplasias de la Mama/patología , Proteínas de Ciclo Celular/genética , Línea Celular Tumoral , Senescencia Celular/genética , Senescencia Celular/inmunología , Chaperoninas/genética , Proteínas Cullin/inmunología , Citocinas/genética , Femenino , Regulación Neoplásica de la Expresión Génica/genética , Regulación Neoplásica de la Expresión Génica/inmunología , Humanos , Interferón gamma/inmunología , Proteolisis , Receptor ErbB-2/antagonistas & inhibidores , Receptor ErbB-2/genética , Células TH1/efectos de los fármacos , Células TH1/metabolismo , VacunaciónRESUMEN
The rapid heat loss and corrosion of nano-aluminum limits the energy performance of metastable intermolecular composites (MICs) in aquatic conditions. In this work, superhydrophobic n-Al/PVDF films were fabricated by the cryogel-templated method. The underwater ignition performance of the energetic films was investigated. The preparation process of energetic materials is relatively simple, and avoids excessively high temperatures, ensuring the safety of the entire experimental process. The surface of the n-Al/PVDF energetic film exhibits super-hydrophobicity. Because the aluminum nanoparticles are uniformly encased in the hydrophobic energetic binder, the film is more waterproof and anti-aging. Laser-induced underwater ignition experiments show that the superhydrophobic modification can effectively induce the ignition of energetic films underwater. The results suggest that the cryogel-templated method provides a feasible route for underwater applications of energetic materials, especially nanoenergetics-on-a-chip in underwater micro-scale energy-demanding systems.
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OBJECTIVES: To determine the effect of high homocysteine (HCY) levels on the severity of coronary artery disease and prognosis after stent implantation. METHODS: A prospective study was conducted on 667 patients with coronary heart disease who underwent drug-eluting stent implantation for the first time at the Department of Cardiology, Huludao Central Hospital, from January 2015 to December 2017. The patients were divided into the control and hyperhomocysteinemia (H-HCY) groups based on the serum HCY levels. The demographic and clinical characteristics of both groups were compared. In addition, the patients were followed up for 1 year to compare the incidence of major adverse cardiovascular and cerebrovascular events (MACCE). Multivariate logistic regression was used to determine the correlation between serum HCY levels and MACCE. RESULTS: Compared with the control group, the stenosis degree was significantly higher among patients in the H-Hcy group, as indicated by more coronary artery lesions (P < 0.001) and higher SYNTAX scores (P < 0.001). After 1 year of follow-up, the incidence of MACCE was also significantly higher in the H-HCY versus control group (9.5% vs. 15.1%; P = 0.042). Furthermore, age, history of diabetes, discontinuation of antiplatelet aggregation drugs, and HCY levels were independent predictors of MACCE. CONCLUSIONS: High HCY level is associated with severe coronary artery disease in patients with coronary heart disease and is an independent predictor of MACCE after stent implantation.
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Enfermedad de la Arteria Coronaria/terapia , Stents Liberadores de Fármacos , Homocisteína/sangre , Hiperhomocisteinemia/sangre , Intervención Coronaria Percutánea/instrumentación , Anciano , Anciano de 80 o más Años , Biomarcadores/sangre , Enfermedad de la Arteria Coronaria/complicaciones , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Femenino , Humanos , Hiperhomocisteinemia/complicaciones , Hiperhomocisteinemia/diagnóstico , Masculino , Persona de Mediana Edad , Intervención Coronaria Percutánea/efectos adversos , Estudios Prospectivos , Medición de Riesgo , Factores de Riesgo , Índice de Severidad de la Enfermedad , Factores de Tiempo , Resultado del TratamientoRESUMEN
Endocrine therapy is one of the main treatments for estrogen receptor-positive breast cancers. Tamoxifen is the most commonly used drug for endocrine therapy. However, primary or acquired tamoxifen resistance occurs in a large proportion of breast cancer patients, leading to therapeutic failure. We found that the combination of tamoxifen and ACT001, a nuclear factor-κB (NF-κB) signaling pathway inhibitor, effectively inhibited the proliferation of both tamoxifen-sensitive and tamoxifen-resistant cells. The tamoxifen-resistant cell line MCF7R/LCC9 showed active NF-κB signaling and high apoptosis-related gene transcription, especially for antiapoptotic genes, which could be diminished by treatment with ACT001. These results demonstrate that ACT001 can prevent and reverse tamoxifen resistance by inhibiting NF-κB activation.
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BACKGROUND: To investigate the predictive value of plasma D-dimer levels for short-term therapeutic effect and progression-free survival (PFS) in patients with small-cell lung cancer (SCLC); and to analyze the correlation between baseline plasma D-dimer levels and other clinicopathological features. The aim of the study was to investigate whether the levels of plasma D-dimer could serve as a predictive and prognostic factor in patients with SCLC. METHODS: A retrospective review of the clinicopathological data of 160 patients with pathologically confirmed SCLC, who were treated at the Department of Thoracic Oncology of Tianjin Medical University Tumor Institute and Hospital between June 2011 and June 2016, was performed. At the same time, we collected 100 patients with benign pulmonary diseases as a control group. The correlations between baseline plasma D-dimer levels and other clinical features, therapeutic effect and PFS were analyzed statistically. RESULTS: The level of plasma D-dimer in patients with SCLC was significantly higher than that of patients with benign pulmonary diseases (P = 0.001). The PFS of patients with elevated D-dimer levels before therapy were significantly shorter than that of patients with normal D-dimer levels (6.0 versus 7.5 months, P = 0.013). The patients whose plasma D-dimer level always (before and after treatment) in the normal range have the best prognosis, and continuously elevated D-dimer carried out a poor prognosis (8.0 versus 5.0 months). According to multivariate analysis, elevated D-dimer level was confirmed to be an independent prognostic factor for worse survival (P = 0.029). The level of D-dimer was associated with tumor stage, the level of neuron-specific enolase, the presence of distant metastasis, hyponatremia, and the Karnofsky performance status score; and levels decreased when therapy was effective, but increased when the disease progressed. CONCLUSIONS: High levels of baseline plasma D-dimer may indicate advanced disease stage and poor prognosis. Therefore, plasma D-dimer levels could serve as a predictive and prognostic factor in patients with SCLC.
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Biomarcadores de Tumor/sangre , Productos de Degradación de Fibrina-Fibrinógeno/análisis , Neoplasias Pulmonares/sangre , Neumonía/sangre , Carcinoma Pulmonar de Células Pequeñas/sangre , Tuberculoma/sangre , Adulto , Anciano , Anciano de 80 o más Años , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Estudios de Casos y Controles , Femenino , Humanos , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/patología , Masculino , Persona de Mediana Edad , Neumonía/tratamiento farmacológico , Neumonía/patología , Pronóstico , Estudios Retrospectivos , Carcinoma Pulmonar de Células Pequeñas/tratamiento farmacológico , Carcinoma Pulmonar de Células Pequeñas/patología , Tasa de Supervivencia , Tuberculoma/tratamiento farmacológico , Tuberculoma/patología , Adulto JovenRESUMEN
There is an intimate connection between mitochondrial DNA (mtDNA) methylation and some diseases, such as cancer. MtDNA is almost strictly maternally inherited. However, whether the aberrant mtDNA methylation involved in breast cancer progression and whether mtDNA methylation can be transmitted through maternal line are poorly understood. Here we applied bisulfite sequencing to global mitochondrial DNA and whole genomic DNA methylation array from fifteen members of five three-female-generation families with one breast cancer patient in each family. We found that mtDNA methylation was maternally inherited in D-loop region and eight aberrant mtDNA methylation sites were correlated with breast cancer. Furthermore, conjoint analysis showed that mtDNA methylation sites could be potential biomarkers combined with nuclear DNA methylation sites for breast cancer risk prediction.
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Neoplasias de la Mama/genética , Metilación de ADN/genética , ADN Mitocondrial/genética , Predisposición Genética a la Enfermedad/genética , Genoma Humano/genética , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , China , Femenino , Humanos , Persona de Mediana EdadRESUMEN
BACKGROUND Translation initiation is the rate limiting step of protein synthesis and is highly regulated. Eukaryotic initiation factor 3C (EIF3C), an oncogene overexpressed in several human cancers, plays an important role in tumorigenesis and cell proliferation. MATERIAL AND METHODS Immunohistochemistry was used to determine the expression of EIF3C in breast cancer tissues from 42 patients. We investigated whether EIF3C silencing decreases breast cancer cell proliferation as assessed by colony formation assay, and whether EIF3C gene knockdown induces apoptosis as assessed by flow cytometry analysis. We utilized the stress and apoptosis signaling antibody array kit, while p-ERK1/2, p-Akt, p-Smad2, p-p38 MAPK, cleaved caspase-3, and cleaved caspase-7 were explored between EIF3C-siRNA and controls. Furthermore, the effects of EIF3C gene knockdown in mTOR pathway were analyzed by western blotting for different cell lines. RESULTS In EIF3C-positive tumors, 32 out of 42 showed significantly higher frequencies of high grade group by immunoreactivity (p=0.0016). BrdU incorporation after four days of cell plating was significantly suppressed in MDA-MB-231 cells by EIF3C knockdown compared with controls, with average changes of 7.8-fold (p<0.01). Clone number was significantly suppressed in MDA-MB-231 cells by EIF3C knockdown compared with controls (p<0.05). Cell apoptosis was significantly increased in the EIF3C-siRNA group when compared with the cells that were transfected with scrambled siRNA (3.51±0.0842 versus 13.24±0.2307, p<0.01). The mTOR signaling pathway was involved in decreasing EIF3C translational efficiency. CONCLUSIONS Unveiling the mechanisms of EIF3 action in tumorigenesis may help identify attractive targets for cancer therapy.
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Neoplasias de la Mama/metabolismo , Factor 3 de Iniciación Eucariótica/metabolismo , Serina-Treonina Quinasas TOR/metabolismo , Adulto , Anciano , Animales , Apoptosis/fisiología , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Caspasa 3/metabolismo , Línea Celular Tumoral , Proliferación Celular/fisiología , Factor 3 de Iniciación Eucariótica/genética , Femenino , Técnicas de Silenciamiento del Gen , Humanos , Células MCF-7 , Persona de Mediana Edad , ARN Interferente Pequeño/administración & dosificación , ARN Interferente Pequeño/genética , Transducción de SeñalRESUMEN
Although aberrant Notch activation contributes to leukemogenesis in T cells, the role of Notch pathway in acute myeloid leukemia (AML) remains controversial. To address this issue, we compared the expression levels of its downstream effector HES1 and p21 in bone marrow mononuclear cells (BMNCs) from 30 newly diagnosed AML patients and three AML cell lines to normal BMNCs. The results showed that both of them were downregulated in AML cells. In vitro, induced activation of HES1 by retrovirus in AML cell lines consistently led to AML cell growth arrest and apoptosis induction, which was associated with enhanced p21 expression. Furthermore, overexpression of HES1 in primary AML cells inhibited growth of AML in a xenograft mice model. In conclusion, we demonstrated the tumor suppressor role of HES1 in AML.
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Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/biosíntesis , Regulación Leucémica de la Expresión Génica , Proteínas de Homeodominio/biosíntesis , Leucemia Mieloide Aguda/metabolismo , Proteínas Supresoras de Tumor/biosíntesis , Adolescente , Adulto , Animales , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Niño , Regulación hacia Abajo , Femenino , Células HL-60 , Xenoinjertos , Proteínas de Homeodominio/genética , Humanos , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/patología , Masculino , Ratones , Ratones Endogámicos NOD , Ratones SCID , Persona de Mediana Edad , Trasplante de Neoplasias , Receptores Notch/genética , Receptores Notch/metabolismo , Factor de Transcripción HES-1 , Proteínas Supresoras de Tumor/genética , Células U937RESUMEN
Cancer stem cells(CSCs) have been reported in many human tumors and are associated with tumor initiation and progression. CSCs share many biological properties with normal somatic stem cells, such as self-renewal, the propagation of differentiated progeny. However, they also have differences in their chemoresistance and tumorigenic and metastatic activity. CSCs have potential clinical importance, but the regulation at the molecular level is not well-understood. MicroRNAs(miRNAs) are a class of endogenous non-coding RNAs, and play important role in the regulation of several cellular processes. Varieties of evidence show that, miRNAs can regulates the CSCs at a molecular level and are associated with tumor initiation and progression. Better understanding of the regulation of CSCs gene expression by miRNAs could be used to identify the biomarkers and therapeutic targets. In the present review, we summarize the major development on the regulation of CSCs by miRNAs.
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Carcinogénesis/metabolismo , MicroARNs/metabolismo , Neoplasias/patología , Células Madre Neoplásicas/metabolismo , Células Madre Neoplásicas/patología , Diferenciación Celular , HumanosRESUMEN
Parthenolide is the main bioactive component in feverfew, a common used herbal medicine, and has been extensively studied in relation to its anti-cancer properties. However there have been very few in-depth studies of the activities of this compound at the molecular level. Here, we showed that parthenolide increased reactive oxygen species (ROS), induced cell death, activated AMPK and autophagy, and led to M phase cell cycle arrest in breast cancer cells. Removal of ROS inhibited all parthenolide-associated events, such as cell death, AMPK activation, autophagy induction, and cell cycle arrest. Blockade of autophagy relieved cell cycle arrest, whereas inhibition of AMPK activity significantly repressed the induction of both autophagy and cell cycle arrest. These observations clearly showed that parthenolide-driven ROS activated AMPK-autophagy pathway. Furthermore, inhibition of either AMPK or autophagy significantly potentiated parthenolide-induced apoptosis. Therefore, our results show that parthenolide activates both apoptosis pathway and AMPK-autophagy survival pathway through the generation of ROS, and that suppression of AMPK or autophagy can potentially enhance the anti-cancer effect of parthenolide on breast cancer cells.
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Proteínas Quinasas Activadas por AMP/genética , Apoptosis/genética , Neoplasias de la Mama/genética , Sesquiterpenos/administración & dosificación , Proteínas Quinasas Activadas por AMP/antagonistas & inhibidores , Apoptosis/efectos de los fármacos , Autofagia/efectos de los fármacos , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/patología , Puntos de Control del Ciclo Celular/efectos de los fármacos , Femenino , Humanos , Células MCF-7 , Especies Reactivas de Oxígeno/metabolismoRESUMEN
AIM: Receptor-interacting protein 3 (RIP3) is involved in tumor necrosis factor receptor signaling, and results in NF-κB-mediated prosurvival signaling and programmed cell death. The aim of this study was to determine whether overexpression of the RIP3 gene could sensitize human breast cancer cells to parthenolide in vitro. METHODS: The expression of RIP3 mRNA in human breast cancer cell lines (MCF-7, MDA-MB-231, MDA-MB-435 and T47D) was detected using RT-PCR. Both MDA-MB-231 and MCF-7 cells were transfected with RIP3 expression or blank vectors via lentivirus. Cell viability was measured with MTT assay; intracellular ROS level and cell apoptosis were analyzed using flow cytometry. RESULTS: RIP3 mRNA expression was not detected in the four human breast cancer cell lines tested. However, the transfection induced higher levels of RIP3 protein in MCF-7 and MDA-MB-231 cells. Furthermore, overexpression of RIP3 decreased the IC50 values of parthenolide from 17.6 to 12.6 µmol/L in MCF-7 cells, and from 16.6 to 9.9 µmol/L in MDA-MB-231 cells. Moreover, overexpression of RIP3 significantly increased parthenolide-induced apoptosis and ROS accumulation in MCF-7 and MDA-MB-231 cells. Pretreatment with N-acetyl-cysteine abrogated the increased sensitivity of RIP3-transfected MCF-7 and MDA-MB-231 cells to parthenolide. CONCLUSION: Overexpression of RIP3 sensitizes MCF-7 and MDA-MB-231 breast cancer cells to parthenolide in vitro via intracellular ROS accumulation.
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Antiinflamatorios no Esteroideos/farmacología , Antineoplásicos/farmacología , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/genética , Regulación Neoplásica de la Expresión Génica , Proteína Serina-Treonina Quinasas de Interacción con Receptores/genética , Sesquiterpenos/farmacología , Apoptosis/efectos de los fármacos , Mama/efectos de los fármacos , Mama/metabolismo , Mama/patología , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Línea Celular Tumoral , Femenino , Eliminación de Gen , Humanos , Especies Reactivas de Oxígeno/metabolismo , Proteína Serina-Treonina Quinasas de Interacción con Receptores/metabolismo , Regulación hacia ArribaRESUMEN
The area of permafrost worldwide accounts for approximately 20% to 25% of land area. In cold-climate regions of China, which are garnering international attention, the study of low-temperature and moisture effects on rock mass mechanical properties is of significant importance. China has a wide area of cold regions. This research can provide a foundation for China's exploration activities in such extreme environments. This paper examines the mechanical behavior of rock specimens subjected to various low temperatures and water contents through uniaxial compression tests. The analysis encompasses failure modes, stress-strain relationships, uniaxial compressive strength (UCS), and elastic modulus (EM) of these specimens. Findings reveal that at lower temperatures, the rock specimens' fracture patterns transition from compressive shear failure to cleavage failure, reflecting a shift from a plastic-elastic-plastic to a plastic-elastic response. Specifically, saturated rocks exhibit a 40.8% decrease in UCS and an 11.4% reduction in EM compared to their dry counterparts. Additionally, in cold conditions, an increased water content in rocks primarily leads to vertical cracking. Under such conditions, saturated rocks show a 52.3% decline in UCS and a 15.2% reduction in EM, relative to their dry state.
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Highly crystalline nano-MFI-type zeolites containing different elements were synthesized, and the sorption effects of the elements on volatile organic compounds (VOCs) were investigated. The results showed that the optimal toluene and acetone breakthrough time of the synthesized zeolites was 2.1 and 1.9 times as long as that of the commercial zeolite, respectively. For a weakly polar toluene molecule, MFI zeolites (aluminum-free) showed better adsorption properties than aluminum-containing zeolites. For the highly polar acetone molecule, zeolites with a Si/Al ratio of 87 showed the highest adsorption capacity, which was 7% higher than that of the all-silica zeolite and 1.4 times that of the commercial zeolite. Furthermore, MFI zeolites with Ti replacing part of Al proved to have better performance for highly polar molecules. In the adsorption process of VOCs, in addition to internal diffusion, diffusion on the external surface of the zeolite also played a remarkable role, and the adsorption data of all samples fitted better with the pseudo-first-order model. This study may provide a reliable structure-performance relationship for the synthesis of nanosized zeolite-based adsorbents and their use in the industrial recovery/treatment of VOCs.
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Si-containing transition-metal nitrides Ti0.5Si0.5N, Zr0.5Si0.5N and Hf0.5Si0.5N with conventional rock salt B1 structure exhibit superior hardness, strength and oxidation resistance. However, the potential phases of the ternary systems at various pressures remain unexplored. In this work, we firstly studied the potential structures of Ti0.5Si0.5N, Zr0.5Si0.5N and Hf0.5Si0.5N in pressures of 0-100 GPa. A hexagonal phase with P63/mmc symmetry was uncovered and verified to be quenchable in the ambient conditions. The structural, mechanical and electronic properties were systematically studied and compared with the well-known ordered B1 structure. We surprisingly found that Ti0.5Si0.5N within this hexagonal phase displayed much improved ideal indentation shear strength from about 10 GPa for a B1 structure to 30 GPa. The estimated hardness based on the empirical formula is up to 38 GPa, greatly exceeding that of the B1 structure. By the detailed electronic analysis, the underlying atomic mechanism for the outstanding mechanical properties was also studied.
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In order to analyze the axial compressive properties of ultra-high-toughness cementitious composite (UHTCC)-confined recycled aggregate concrete (RAC), a batch of UHTCC-confined RAC components was designed and manufactured according to the requirements of GB/T50081-2002 specifications. After analyzing the surface failure phenomenon, load-displacement curves, scanning electron microscope (SEM), and parameter analysis of the specimen, the result shows that UHTCC-confined RAC is an effective confinement method, which can effectively improve the mechanical properties and control the degree of surface failure of RAC structures. Compared with the unconfined specimen, the maximum peak load of the UHTCC confinement layer with a thickness of 10 mm and 20 mm increased by 44.61% and 79.27%, respectively, meeting the requirements of engineering practice. Different fiber mixing amounts have different effects on improving the mechanical performance of RAC structural. The specific rule was steel fiber (SF) > polyvinyl alcohol fiber (PVAF) > polyvinyl alcohol fiber (PEF) > no fiber mixture, and the SF improves the axial compression properties of UHTCC most significantly. When there are strict requirements for improving the mechanical properties of the structure, SF should be added to UHTCC. On the contrary, PVAF should be added to UHTCC.
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AIM: Photodynamic therapy (PDT) is an emerging treatment used to eradicate premalignant and early-stage cancers and to reduce tumor size in end-stage cancers. In this study, we investigated the effects of a combination of benzoporphyrin derivative monoacid ring A (BPD-MA)-mediated PDT with adriamycin (ADM) on 4T1 breast carcinoma cells in vivo and the mechanisms underlying this effect. METHODS: Normal BALA/c female mice bearing 4T1 breast carcinoma xenografts were tested. The animals were treated with PDT (BPD-MA 1 mg/kg, iv, plus single-dose laser irradiation) or ADM (5 mg/kg, iv) alone, or a combination of PDT with ADM. The tumor growth rate was determined by measuring the tumor weight. Cell apoptosis was measured with flow cytometry, and the expression of apoptosis-related molecules was assessed using Western blot. Microvessel density (MVD) was determined with immunohistochemical staining. RESULTS: Compared to PDT or ADM alone, PDT plus ADM produced a combined inhibition on the tumor growth, prolonged life span, and enhanced apoptosis in the mice bearing 4T1 subcutaneously xenografted tumors. The combination of PDT and ADM exerted additive effects on the upregulation of Bax and the downregulation of Bcl-2, and on the reduction of MVD in 4T1 xenografted tumors. CONCLUSION: Our results demonstrate that PDT plus ADM exerts enhanced in vivo antitumor effect on breast cancer, which is closely associated with the cooperative regulation of extrinsic apoptotic pathways and the inhibition of tumor angiogenesis. Thus, PDT plus ADM is a promising combined treatment strategy for breast carcinoma.
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Antibióticos Antineoplásicos/uso terapéutico , Doxorrubicina/uso terapéutico , Neoplasias Mamarias Experimentales/tratamiento farmacológico , Fotoquimioterapia/métodos , Fármacos Fotosensibilizantes/uso terapéutico , Porfirinas/uso terapéutico , Animales , Antibióticos Antineoplásicos/administración & dosificación , Antígenos CD34/biosíntesis , Apoptosis/efectos de los fármacos , Western Blotting , Línea Celular Tumoral , Doxorrubicina/administración & dosificación , Endotelio Vascular/efectos de los fármacos , Endotelio Vascular/metabolismo , Femenino , Humanos , Inmunohistoquímica , Neoplasias Mamarias Experimentales/irrigación sanguínea , Neoplasias Mamarias Experimentales/patología , Ratones , Ratones Endogámicos BALB C , Microvasos/efectos de los fármacos , Microvasos/metabolismo , Fármacos Fotosensibilizantes/administración & dosificación , Porfirinas/administración & dosificación , Análisis de Supervivencia , Verteporfina , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
The prefabricated artificial filled jointed rock specimens are impacted by a self-made drop hammer impact device for many times, and the specimens with different degrees of cumulative damage characteristics are obtained. Then, the static and dynamic compression mechanical properties are studied by using universal testing machine and SHPB device. Through the static compression test, the strength and deformation characteristics of jointed rock specimens after multiple impacts are obtained, and the influence of the damage degree of jointed rock specimens characterized by wave velocity on the compressive strength of filled joints is analysed. Based on the results of SHPB impact test, the dynamic strength and deformation evolution, wave propagation law and energy dissipation law of filled joints after multiple impacts are analysed. During the SHPB test, the impact failure process of rock specimens is recorded by a high-speed camera. The experimental results show that the damage degree of jointed rock samples increases nonlinearly after multiple impacts. The attenuation laws of static strength and dynamic strength of rock samples under the same damage evolution conditions are different. With the increase of impact times, the failure mode of jointed rock samples after damage is simpler and tends to compression failure.
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In this study, polyurea was experimentally tested under various spraying temperatures and pressures. The number of holes and the pore size produced after the tensile fracture of the polyurea were counted to illustrate the effect of the various spraying temperatures and pressures on the performance of the polyurea. The tensile characteristics of polyurea were greatly influenced by the spraying temperatures and pressures, according to the experimental findings and statistical analysis. The polyurea tensile performance was best when the spraying pressure was 17.25 MPa with a spraying temperature of 70 °C. The fracture mechanism was illustrated by the silver streaking phenomenon generated during the tensile stretching process. The fracture energy was absorbed by the fracture holes and pores during silver streaking, thus creating the huge gap in tensile properties.