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The flammability of polypropylene (PP) not only has negative effects on human health but also causes environmental pollution. Herein, from the molecular polarity point of view, rationally designed hyperbranched charring foaming agents (HCFA) modified black phosphorus nanosheets by in situ polymerization to solve the fire hazards of PP. Based on the UL-94 test V-0 rating, the conventional flame retardant of piperazine pyrophosphate (PAPP) is substituted partly by the BP@PPC. Surprisingly, compared with 27 wt% of PAPP/PP, composites consisting of only 2 wt% of BP@PPC and 20 wt% PAPP/PP also passes the V-0 rating. The results of the cone calorimeter test confirmed that adding BP@PPC decreases the total heat release (THR) and peak heat release (PHRR) by a large amount, which are decreased by 23.4%, 85.8% respectively compared with PP. Moreover, it is uncommon for the fire growth index of BP@PPC composites to be 66.7% lower than that of PAPP/PP composites. In addition, the incorporation of BP@PPC has almost no impact on the mechanical characteristics of PP composites. This study offers a reference for combining established flame retardants with novel compounds to modify the burning behaviors of PP.
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Difosfatos , Retardadores de Chama , Humanos , Polipropilenos , Fósforo , PiperazinaRESUMO
The toxic smoke produced by the combustion of flexible polyurethane foam (FPUF) may not only caused casualties, but also polluted the environment. Here, double metal hydroxide derived from ZIF-67 (MOF-LDH) modified Ti3C2TX (Ti3C2TX@MOF-LDH) was innovatively designed to solve the serious smoke and fire hazards of FPUF. The FPUF nanocomposite containing 6 wt% Ti3C2Tx@MOF-LDH achieved a 16.1% reduction in total smoke production (TSP) along with 22.2% reduction in peak smoke production rate (PSPR), which greatly reduced the hazard of smoke. At the same time, toxic gases, such as carbon monoxide (CO), carbon dioxide (CO2), and aromatic compounds, showed the same reduction pattern. In addition, the heat release of FPUF nanomaterials was also suppressed. In particular, the FPUF/Ti3C2Tx@MOF-LDH 3.0 achieved 110.4% and 76.1% increase in compressive strength and tensile strength, respectively, confirming the effective mechanical enhancement. Therefore, this work provided a new reference for the preparation of high-performance FPUF nanocomposites with low smoke, low fire hazard and excellent mechanical properties.
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Caramujo Conus , Incêndios , Animais , Monóxido de Carbono , Gases , FumaçaRESUMO
OBJECTIVE: There is no universal consensus on whether gonadotropin-releasing hormone (GnRH) agonist could protect chemotherapy-induced ovarian damage in premenopausal breast cancer patients. This meta-analysis was conducted to estimate the protective effects of GnRH agonist on premenopausal breast cancer patients in details. METHODS: PubMed, Cochrane Library, Embase, CNKI and the Chinese Wangfang Database, conference proceedings and clinical trials were searched to find studies reported since 2000. Heterogeneity for the eligible data was assessed and a pooled odds ratio (OR) with 95% confidence interval (CI) was calculated. RESULTS: Resumption of menses rate was improved in the GnRH agonist and chemotherapy-combination groups versus chemotherapy-alone groups (OR = 1.36, 95% CI: 1.19-1.56). Furthermore, the results indicated that spontaneous pregnancy rate was improved in the experimental groups versus the controls (OR = 1.90, 95% CI: 1.06-3.41). In addition, no publication bias was found using a Begg's funnel plot. CONCLUSION: The results of the current meta-analysis indicate that a GnRH agonist could improve resumption of menses rate and pregnancy rate for premenopausal breast cancer patients. However, more evaluation may be considered to prove this theory.
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Hypoxia is a major cause of treatment resistance in breast cancer. Single-walled carbon nanotubes (SWCNTs) exhibit unique properties that make them promising candidates for breast cancer treatment. In the present study, a new functionalized single-walled carbon nanotube carrying oxygen was synthesized; it was determined whether this material could increase chemosensitivity and radiosensitivity of human breast cancer cell lines, and the underlying mechanisms were investigated. MDA-MB-231 cells growing in folic acid (FA) free medium, MDA-MB-231 cells growing in medium containing FA and ZR-75-1 cells were treated with chemotherapy drugs or radiotherapy with or without tombarthite-modified-FA-chitosan (R-O2-FA-CHI)-SWCNTs under hypoxic conditions, and the cell viability was determined by water-soluble tetrazolium salts-1 assay. The cell surviving fractions were determined by colony forming assay. Cell apoptosis induction was monitored by flow cytometry. Expression of B-cell lymphoma 2 (Bcl-2), survivin, hypoxia-inducible factor 1-α (HIF-1α), multidrug resistance-associated protein 1 (MRP-1), P-glycoprotein (P-gp), RAD51 and Ku80 was monitored by western blotting. The novel synthesized R-O2-FA-CHI-SWCNTs were able to significantly enhance the chemosensitivity and radiosensitivity of human breast cancer cell lines and the material exhibited its expected function by downregulating the expression of Bcl-2, survivin, HIF-1α, P-gp, MRP-1, RAD51 and Ku80.
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PURPOSE: To investigate the effects of trastuzumab (herceptin) and fulvestrant (falsodex) either in combination or alone, on downstream cell signaling pathways in lab-cultured human HR+/HER2+ breast cancer cell lines ZR-75-1 and BT-474, as well as on protein expression levels in mouse xenograft tissue. METHODS: Cells were cultivated in the presence of trastuzumab or fulvestrant or both. Molecular events that resulted in an inhibition of cell proliferation and cell cycle progression or in an increased rate of apoptosis were studied. The distribution and abundance of the proteins p-Akt and p-Erk expressed in these cells in response to single agents or combinatorial treatment were also investigated. In addition, the effects of trastuzumab and fulvestrant, either as single agents or in combination on tumor growth as well as on expression of the protein p-MED1 expressed in in vivo mouse xenograft models was also examined. RESULTS: Cell proliferation was increasingly inhibited by trastuzumab or fulvestrant or both, with a CI<1 and DRI>1 in both human cell lines. The rate of apoptosis increased only in the BT-474 cell line and not in the ZR-75-1 cell line upon treatment with fulvestrant and not trastuzumab as a single agent (P<0.05). Interestingly, fulvestrant, in combination with trastuzumab, did not significantly alter the rate of apoptosis (in comparison with fulvestrant alone), in the BT-474 cell line (P>0.05). Cell accumulation in the G1 phase of cell cycle was investigated in all treatment groups (P<0.05), and the combination of trastuzumab and fulvestrant reversed the effects of fulvestrant alone on p-Akt and p-Erk protein expression levels. Using ZR-75-1 or BT-474 to generate in vivo tumor xenografts in BALB/c athymic mouse models, we showed that a combination of both drugs resulted in a stronger inhibition of tumor growth (P<0.05) and a greater decrease in the levels of activated MED1 (p-MED1) expressed in tumor issues compared with the use of either drug as a single agent. CONCLUSIONS: We demonstrate that the administration of trastuzumab and fulvestrant in combination results in positive synergistic effects on both, ZR-75-1 and BT-474 cell lines. This combinatorial approach is likely to reduce physiological side effects of both drugs, thus providing a theoretical basis for the use of such combination treatment in order to resolve HR+/HER2+ triple positive breast cancer that has previously been shown to be resistant to endocrine treatment alone.
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Neoplasias da Mama/tratamento farmacológico , Estradiol/análogos & derivados , Receptor ErbB-2/metabolismo , Trastuzumab/administração & dosagem , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Apoptose , Neoplasias da Mama/metabolismo , Ciclo Celular , Linhagem Celular Tumoral , Proliferação de Células , Resistencia a Medicamentos Antineoplásicos , Estradiol/administração & dosagem , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Feminino , Citometria de Fluxo , Fulvestranto , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
A Highly efficient method was developed for preparing starch-based wood adhesives with high performance, using H2O2, a silane coupling agent and an olefin monomer as an oxidant, cross-linking agent and comonomer, respectively. The effects of various parameters on the shear adhesive strength were investigated in the dry state (DS) and wet state (WS). The results indicated that the bonding strength of starch-based wood adhesives could reach 7.88 MPa in dry state and 4.09 MPa in wet state. The oxidation could reduce the content of the hydroxyl transforming into carboxyl and aldehyde groups, and the graft copolymerization enhanced the thermal stability, which improved the bonding strength and water resistance. The starch-based adhesive and the fractures in the bonded joints were analyzed via Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). The improved properties were attributed to the modified of microstructure of the graft-copolymerized starch-based adhesive.
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OBJECTIVE: To study the in vivo and in vitro effects of adding oxygen carbon nanotubes (CNTs) to chemotherapy for breast cancer. METHODS: MCF-7 and SK-BR-3 breast cancer cells were co-cultured with paclitaxel and then exposed to oxygen-CNTs under hypoxic conditions. Cell proliferation, viability, and apoptosis rate were analyzed. Hypoxia-inducible factor-1 alpha (HIF-1α) expression was measured using reverse transcription-polymerase chain reaction (RT-PCR) and western blot. Nude mice were used as a human breast cancer model to explore the impact of oxygen-CNTs on the in vivo chemotherapeutic effect of paclitaxel. RESULTS: Oxygen-CNTs had no significant effects on the growth of breast cancer cells under normoxia and hypoxia. However, in the hypoxic environment, oxygen-CNTs significantly enhanced the inhibitory effect of paclitaxel on cell proliferation, as well as the apoptosis rate. Under hypoxia, downregulation of HIF-1α and upregulation of caspase-3, caspase-8, caspase-9, LC3 and Beclin-1 were observed when paclitaxel was combined with oxygen-CNT. Furthermore, addition of oxygen-CNTs to chemotherapy was found to significantly reduce tumor weight in the tumor-bearing mice model. CONCLUSIONS: Oxygen-CNTs can significantly increase the chemotherapeutic effect of paclitaxel on breast cancer cells. Oxygen-CNTs may be a potential chemosensitizer in breast cancer therapy.
Assuntos
Neoplasias da Mama/tratamento farmacológico , Nanotubos de Carbono/química , Oxigênio/administração & dosagem , Paclitaxel/administração & dosagem , Animais , Apoptose/efeitos dos fármacos , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Hipóxia Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Feminino , Humanos , Células MCF-7 , Camundongos , Oxigênio/química , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
The aim of this study was to assess associations between ER, Ki67, Her-2 phenotypes, molecular subtypes of breast cancer and circulating levels of lymphocyte subsets (CD4+, CD8+, NK, CD19+, CD20+) and the ratio of CD4+ to CD8+ prior to treatment. Cells from peripheral blood were counted by flow cytometry, ER, Her-2, and Ki67 expressions were detected by pathological examination, and Her-2 was also detected by FISH. We conducted a case-case comparison of 494 women with newly diagnosed breast cancer to evaluate association between levels of lymphocyte subsets in peripheral blood and breast cancer phenotypes [ER- vs. ER+; Ki67 ≥ 14 % vs. Ki67 < 14 %; Her-2+ vs. Her-2-; triple-negative breast cancer (TNBC) vs. luminal A]. Women with the highest levels of CD3+ (OR 0.45, 95 % CI 0.22-0.94), CD4+ (OR 0.22, 95 % CI 0.08-0.59), and the ratio of CD4+/CD8+ (OR 0.17, 95 % CI 0.06-0.47) were least likely to have TNBCs compared with luminal A cancers. The highest tertile of CD8+ (OR 3.67, 95 % CI 1.06-12.72) and NK (OR 2.64, 95 % CI 1.12-6.24) was significantly associated with TNBC compared with luminal A cancer. ER-, Ki67 ≥ 14 %, Her-2+ were associated with low levels of CD4+ and CD4+/CD8+ compared with ER+, Ki67 < 14 %, Her-2-. Women in the highest level of CD8+ had more likelihood to have ER- and Her-2+ compared with ER+ and Her-2-. High levels of NK cells were associated with increased risk of ER- compared with ER+ cancers. Highest levels of CD19+ and CD20+ were associated with low risk of ER-, compared with ER+ cancers. These findings show that immune function differs among different breast cancer phenotypes or subtypes and is associated with ER-, Her-2+, Ki67 ≥ 14 %, and TNBC which are likely to be aggressive phenotypes.
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Neoplasias da Mama/sangue , Neoplasias da Mama/patologia , Subpopulações de Linfócitos , Idoso , Antígenos CD19/metabolismo , Antígenos CD20/metabolismo , Neoplasias da Mama/metabolismo , Complexo CD3/metabolismo , Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD8-Positivos/metabolismo , Feminino , Humanos , Antígeno Ki-67/metabolismo , Células Matadoras Naturais/metabolismo , Subpopulações de Linfócitos/metabolismo , Subpopulações de Linfócitos/patologia , Pessoa de Meia-Idade , Receptor ErbB-2/genética , Receptor ErbB-2/metabolismo , Receptores de Estrogênio/metabolismo , Neoplasias de Mama Triplo Negativas/metabolismo , Neoplasias de Mama Triplo Negativas/patologiaRESUMO
In the present study, the carboxyl content of oxidized starch was determined by FTIR spectroscopy. Standard curve was drawn in which the ordinate was carboxyl content determined by national standard method with the ratio of carbonyl absorbance to the key of C-H absorbance in FTIR spectroscopy as the abscissa. The ratio of absorbance of unknown oxidized starch tested by FTIR spectroscopy was obtained, The carboxyl content was calculated by standard curve, and then compared with the carboxyl content determined by national standard method, and the deviation is between 2% and 4%. In order to improve the accuracy of the experiment, standard sample was selected to draw standard curve to better ensure that the carboxyl content of the unknown oxidized starch is in the range of standard curve calculation limit, and deviates from the limit of standard curve. Compared with the carboxyl content determined by national standard method, testing with FTIR spectroscopy is simple, easy to operate, and of high efficiency and better accuracy. So, it is significant to forecast the carboxyl content of oxidized starch by FTIR spectroscopy.