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INTRODUCTION: Isoflurane-associated perioperative neurocognitive disorders (PNDs) is a common complication that occurs commonly in elderly patients characterized by deterioration of hippocampus-dependent cognitive function. Mounting evidence has shown that hippocampal impairment and inflammatory processes are implicated in the pathogenesis of PNDs. Catalpol has been suggested to play a role in the modulation of neuroprotection and neurotransmission. Therefore, we surmised that catalpol may play a similar role during isoflurane-induced PNDs. METHODS: In our current study, aged mice were exposed to isoflurane to develop a mouse model of PNDs and preconditioned with catalpol for 2 weeks before modeling. Three weeks after isoflurane exposure, behavioral, histological, biochemical, electrophysiological, and immunofluorescent assays were performed. RESULTS: Our results showed that catalpol preadministration significantly alleviated cognitive impairment in the Morris water maze, novel object recognition, and Y-maze behavioral tests. Neuropathological analyses showed that catalpol preadministration reduced the loss of neurons and synapses; in line with this, it is revealed that hippocampal synaptic plasticity was restored. Mechanistically, catalpol preadministration suppressed the activation of microglia and decreased the expression of NLRP3 inflammasome. CONCLUSION: Our results indicate that catalpol preadministration could effectively alleviate cognitive impairment and neuropathological damage in isoflurane-exposed aged mice with its neuroprotective effects via modulation of the NLRP3 inflammatory pathway. Furthermore, the NLRP3 inflammatory pathway was revealed to be involved in these effects.
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Isoflurano , Ratones , Animales , Isoflurano/toxicidad , Isoflurano/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Hipocampo/metabolismo , Glucósidos Iridoides/uso terapéutico , Glucósidos Iridoides/metabolismo , Glucósidos Iridoides/farmacología , Aprendizaje por LaberintoRESUMEN
A mammary gland-specific expression vector p205C3 was constructed with the 5'- and 3'-flanking regions of ß-lactoglobulin gene and the first intron of ß-casein gene of Chinese dairy goat as regulatory sequences. Human lysozyme (hLYZ) cDNA from mammary gland was cloned into p205C3 and the recombinant vector was used to generate transgenic mice by microinjection. Based on the lysoplate assay, four female offspring of one male founder were detected expressing recombinant hLYZ in their milk at the levels of 5-200 mg/l, and the expressed protein had the same molecular weight as that of normal hLYZ. Besides mammary glands, ectopic expressions were also found in the spleens and the small intestines of the transgenic mice. Among the offspring, the female transgenic mice maintained and expressed the transgene stably with a highest expression level of 750 mg/l. Therefore, p205C3 could be used to develop animal mammary gland bioreactors expressing hLYZ.
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Vectores Genéticos , Leche/metabolismo , Muramidasa/genética , Ingeniería de Proteínas/métodos , Proteínas Recombinantes/genética , Animales , Caseínas/genética , Femenino , Regulación de la Expresión Génica , Cabras/genética , Humanos , Intrones , Lactoglobulinas/genética , Glándulas Mamarias Animales , Ratones Transgénicos , Muramidasa/metabolismo , Proteínas Recombinantes/metabolismoRESUMEN
Microplastics (MPs) are plastic particles < 5 mm in diameter, of which polystyrene microplastics (PS-MPs) are representative type. The extracellular matrix (ECM) degradation of macrophages is associated with the development of emphysema. Additionally, circular RNAs (circRNAs) have a regulatory role in epigenetic mechanisms related to lung disease. However, the mechanisms of the ECM degradation and circRNAs in MPs-induced emphysema are still unclear. In our study, Sprague-Dawley (SD) rats were treated with 0, 0.5, 1.0 and 2.0 mg/m3 100 nm PS-MPs for 90 days in an inhalation experiment. PS-MPs-exposed rats showed elevated airway resistance and pulmonary dysfunction. Lung histopathology exhibited inflammatory cell infiltration, septal thickening and alveolar dilatation. Exposure to PS-MPs was able to induce elevated levels of ECM degradation-related markers MMP9 and MMP12, as well as reduced levels of elastin in rat lung tissues. CircRNA_SMG6 is a non-coding RNA (ncRNA) with a homologous circular structure in human, rat and mouse. The expression level of circRNA_SMG6 was decreased in both rat lung tissues exposed to PS-MPs and PS-MPs-treated THP-1 cells. The luciferase reporter gene demonstrated that circRNA_SMG6 combined with miR-570-3p and co-regulated PTEN, the target gene of miR-570-3p. Moreover, overexpression of circRNA_SMG6 or inhibition of miR-570-3p attenuated PS-MPs-induced ECM degradation in THP-1 cells. Taken together, circRNA_SMG6 may have a significant function in the deterioration of emphysema caused by PS-MPs-induced macrophage ECM degradation by regulating miR-570-3p. Our findings reveal a novel mechanism of emphysema caused by PS-MPs and provide valuable information for assessing the health risks of MPs.
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Enfisema , Matriz Extracelular , MicroARNs , Microplásticos , ARN Circular , Animales , Humanos , Masculino , Ratas , Enfisema/inducido químicamente , Enfisema/patología , Matriz Extracelular/metabolismo , Matriz Extracelular/efectos de los fármacos , Pulmón/patología , Pulmón/efectos de los fármacos , Macrófagos/efectos de los fármacos , Macrófagos/metabolismo , Macrófagos Alveolares/efectos de los fármacos , Macrófagos Alveolares/metabolismo , Microplásticos/toxicidad , MicroARNs/genética , MicroARNs/metabolismo , Ratas Sprague-Dawley , ARN Circular/genética , ARN Circular/metabolismo , Endorribonucleasas/genética , Endorribonucleasas/metabolismoRESUMEN
Microplastics (MPs), the emerging environmental contaminants, can be inhaled and lead to lung injuries, including inflammation and fibrosis. Alveolar epithelial cell senescence is associated with several lung diseases, but its mechanism in MPs-induced lung injuries remains unknown. In this study, polystyrene microplastics (PS-MPs) in the form of microspheres with a particle size of 100 nm were used for a 35-day inhalation exposure in SPF-grade Sprague-Dawley (SD) rats. The plethysmograph showed lung dysfunction. The hematoxylin and eosin (H&E) staining revealed lung histological lesions with a significant accumulation of inflammatory cells. The ß-galactosidase staining indicated increased senescent cells in lung tissues. The ELISA suggested increased senescence-associated secretory phenotype (SASP) in bronchoalveolar lavage fluid (BALF). Treatment of mouse alveolar epithelial cell line MLE12 with PS-MPs raised levels of senescence-related markers p21, p16, and p27 and SASP secretion. circ_kif26b, a ring-structured non-coding RNA (ncRNA), is homologous in human, rat, and mouse and was elevated in PS-MPs-exposed rat lung tissues as well as in PS-MPs-treated MLE12 cells. The luciferase reporter gene revealed that circ_kif26b was bound to miR-346-3p and co-regulated p21, a target gene of miR-346-3p. circ_kif26b knockdown or miR-346-3p overexpression attenuated PS-MPs-induced MLE12 cell senescence and secretion of the SASP cytokines IL-6 and IL-8. However, down-regulation of circ_kif26b and miR-346-3p reversed this depressive effect. Overall, circ_kif26b mediates alveolar epithelial cell senescence through miR-346-3p and participates in PS-MPs-induced lung inflammation. These findings provide new insights into the mechanisms of MPs inhalation toxicity and lay a mechanistic foundation for health risk assessment of MPs.
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Lesión Pulmonar , MicroARNs , Humanos , Ratones , Ratas , Animales , Ratas Sprague-Dawley , Células Epiteliales Alveolares , Lesión Pulmonar/inducido químicamente , Microplásticos , Plásticos , ARN Circular , CinesinasRESUMEN
Background: Health-related quality of life (HRQoL) is a critical aspect of overall well-being for patients with lung cancer, particularly those with metastatic spinal cord compression (MSCC). However, there is currently a lack of universal evaluation of HRQoL in this specific patient population. The aim of this study was to develop a nomogram that can accurately predict HRQoL outcomes in patients with lung cancer-related MSCC. Methods: A total of 119 patients diagnosed with MSCC secondary to lung cancer were prospectively collected for analysis in the study. The least absolute shrinkage and selection operator (LASSO) regression analysis, along with 10-fold cross-validation, was employed to select the most significant variables for inclusion in the nomogram. Discriminative and calibration abilities were assessed using the concordance index (C-index), discrimination slope, calibration plots, and goodness-of-fit tests. Net reclassification index (NRI) and integrated discrimination improvement (IDI) analyses were conducted to compare the nomogram's performance with and without the consideration of comorbidities. Results: Four variables were selected to construct the final nomogram, including the Eastern Cooperative Oncology Group (ECOG) score, targeted therapy, anxiety scale, and number of comorbidities. The C-index was 0.87, with a discrimination slope of 0.47, indicating a favorable discriminative ability. Calibration plots and goodness-of-fit tests revealed a high level of consistency between the predicted and observed probabilities of poor HRQoL. The NRI (0.404, 95% CI: 0.074-0.734, p = 0.016) and the IDI (0.035, 95% CI: 0.004-0.066, p = 0.027) confirmed the superior performance of the nomogram with the consideration of comorbidities. Conclusions: This study develops a prediction nomogram that can assist clinicians in evaluating postoperative HRQoL in patients with lung cancer-related MSCC. This nomogram provides a valuable tool for risk stratification and personalized treatment planning in this specific patient population.
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Neoplasias Pulmonares , Compresión de la Médula Espinal , Humanos , Calidad de Vida , Compresión de la Médula Espinal/etiología , Compresión de la Médula Espinal/cirugía , Neoplasias Pulmonares/complicaciones , Neoplasias Pulmonares/cirugía , Calibración , NomogramasRESUMEN
Colloidal clusters and gels are ubiquitous in science and technology. Particle softness has a strong effect on interparticle interactions; however, our understanding of the role of this factor in the formation of colloidal clusters and gels is only beginning to evolve. Here, we report the results of experimental and simulation studies of the impact of particle softness on the assembly of clusters and networks from mixtures of oppositely charged polymer nanoparticles (NPs). Experiments were performed below or above the polymer glass transition temperature, at which the interaction potential and adhesive forces between the NPs were significantly varied. Hard NPs assembled in fractal clusters that subsequently organized in a kinetically arrested colloidal gel, while soft NPs formed dense precipitating aggregates, due to the NP deformation and the decreased interparticle distance. Importantly, interactions of hard and soft NPs led to the formation of discrete precipitating NP aggregates at a relatively low volume fraction of soft NPs. A phenomenological model was developed for interactions of oppositely charged NPs with varying softnesses. The experimental results were in agreement with molecular dynamics simulations based on the model. This work provides insight on interparticle interactions before, during, and after the formation of hard-hard, hard-soft, and soft-soft contacts and has impact for numerous applications of reversible colloidal gels, including their use as inks for additive manufacturing.
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Microplastics (MPs) pollution has become a global concern due to its close relation to the environment and human health. Recently, more and more studies have pointed out the existence of MPs in the air, but its potential inhalation toxicity is unclear. Polystyrene Microplastics (PS-MPs) is one of the representative MPs. Besides, non-coding RNA plays crucial roles in regulating gene expression. Therefore, this study aims to provide new insights into the molecular exploration of PS-MPs inhalation. In this study, Sprague Dawleyï¼SDï¼rats were treated with 100 nm, 500 nm, 1 µm and 2.5 µm PS-MPs for three days. And then intra-tracheal instillation of saline or 100 nm PS-MPs with 0, 0.5, 1 and 2 mg/200 µL were performed in SD rats every two days for two consecutive weeks. The deposition of PS-MPs was observed through immunofluorescence. Lung histological alternations were observed in haematoxylin and eosin (H&E) staining sections. The expressions of pro-inflammatory cytokines were quantified by ELISA and qPCR. Genome-wide transcriptomic profiling of long noncoding RNAs (lncRNAs), circular RNAs (circRNAs) in rats lung were done by ribosomal RNA depleted RNA sequencing and verified by qRT-PCR. We observed that 100 nm and 1 µm PS-MPs could deposite in the lungs. In addition, pathological examination shows alveolar destruction and bronchial epithelium arranged in a mess in PS-MPs groups. Furthermore, the expressions of pro-inflammatory cytokines IL-6, TNF-α and IL-1ß were upregulated in PS-MPs exposed rats. Sequencing results showed that 269 circRNAs and 109 lncRNAs were differentially expressed in lung tissue of the saline and PS-MPs exposed rats. The upregulated expressions of lncRNA XLOC_031479, circRNA 014924 and circRNA 006603 and the downregulated expressions of lncRNA XLOC_014188 and circ003982 were identified by qRT-PCR in MPs group. The identified novel circRNAs and lncRNAs may paly important role in the development of lung inflammation caused by PS-MPs.
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Lesión Pulmonar , ARN Largo no Codificante , Animales , Citocinas , Lesión Pulmonar/inducido químicamente , Microplásticos , Plásticos , Poliestirenos/toxicidad , ARN Circular , ARN Largo no Codificante/genética , Ratas , Ratas Sprague-DawleyRESUMEN
Aloe vera has been widely used in health and nutritional supplements in Chinese herbal medicine. Furthermore, Aloe vera production has been an emerging industry for making cosmetics and functional food. However, the reported adverse effects raised questions as to whether Aloe vera and its products were safe enough to be used in medicine and health care. In view of this, the safety evaluation of Aloe vera products before marketing is very important. The present study aimed to assess the toxicological profile of Aloe vera soft capsule (ASC), through acute, subacute toxicity and genotoxicity tests. Male and female ICR mice were received by oral gavage 15000 mg/kg bodyweight of ASC in the acute toxicity test. Male and female SD rats were fed on diet blended with different doses of ASC (equivalent to 832.5, 1665 and 3330 mg/kg bodyweight of ASC) for the subacute toxicity test. In the acute toxicity study, no mortality or behavioral changes were observed, indicating the LD50 was higher than 15000 mg/kg bodyweight. In the subacute toxicity test, no significant changes were observed in bodyweight, food consumption, hematological, biochemical or histopathological parameters in the rats exposed. These data suggested that ASC used in this study did not produce any marked subacute toxic effects up to a maximum concentration of 3330 mg/kg bodyweight. In the genotoxicity study, ASC showed no mutagenic activity in the Ames test and no evidence of potential to induce bone marrow micronucleus or testicular chromosome aberrations in ICR mice exposed to 10000 mg/kg bodyweight. Collectively, ASC could be considered safe before it was marketed as a laxative and moistening health food.
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Aloe/toxicidad , Pruebas de Mutagenicidad , Seguridad , Pruebas de Toxicidad Aguda , Animales , Cápsulas , Daño del ADN , Ratones , Ratas , Ratas Sprague-DawleyRESUMEN
BACKGROUND: Three-dimensional (3D) image reconstruction technology is widely used in surgical operations for its intuitive visualization. Pyeloplasty requiresprecise cutting and suturing. The reconstruction technology can accurately determine the location and scope of the stenosis at the junction of the renal pelvis and ureter and the relationship with the surrounding vasculature. The purpose of this article is to retrospective evaluate the application value of image reconstruction technology in pyeloplasty based on high-resolution 3D CT images. METHODS: A total of 20 patients with renal pelvic ureteral junction obstruction admitted to our hospital from August 2019 to August 2020 were selected. In this group, left pyeloplasty was performed in 8 patients and right pyeloplasty in 12 patients. In terms of conditions, there was 1 case with secondary pyeloplasty, 6 cases of patients with kidney stones, 2 cases with renal ectopic blood vessels, 1 case with renal prolapse, 1 case with horseshoe kidney, and 1 case with ureteral polyps. There were 12 males and 8 females, with an average age of 34.65±10.67 years and an average body mass index (BMI) of 22.48±3.03 kg/m2. In all patients, 3D CT reconstruction technology was used to guide the formulation of robot-assisted laparoscopic pyeloplasty plans; verify the consistency between the actual operation and the preoperative planning; and observe the operation time, blood loss, postoperative exhaust time, indwelling drainage tube time, and follow-up for comorbidities. RESULTS: The operation was successful in all 20 patients. The actual operation was 100% consistent with the preoperative planning, the operative time was 160.80±63.26 min, the intraoperative blood loss was 47±30.45 mL, the postoperative exhaust time was 1.15±0.37 days, the drainage tube indwelling time was 4.35±1.50 days, and the average follow-up time was 7.95±3.41 months. There were no complications. CONCLUSIONS: Three-dimensional image reconstruction technology based on high-resolution CT has high clinical application value in the treatment of ureteropelvic junction obstruction (UPJO), which simplifies the operation process and shortens the operation time, and is a valuable tool for auxiliary surgeons in devising the operation plan.
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ETHNOPHARMACOLOGICAL RELEVANCE: Fufang-Yinhua-Jiedu Granules (FFYH) optimized from a Yin-Qiao-San, as traditional Chinese medicine (TCM), was used to treat influenza and upper respiratory tract infection and was recommended for the prevention and treatment of SARS in 2003 and current COVID-19 in Anhui Province in 2020. AIM OF STUDY: In the clinical studies, FFYH was very effective for the treatment of influenza, but the mechanism of action against influenza A virus remains unclear. In the present study, we investigated the antiviral effect of FFYH against influenza A virus in vitro and vivo. Moreover, the potential mechanism of FFYH against influenza A virus in vivo was investigated for the first time. MATERIALS AND METHODS: CPE inhibition assay and HA assay were used to evaluate the in vitro antiviral effects of FFYH against influenza A virus H1N1, H3N2, H5N1, H7N9 and H9N2. Mice were used to evaluate the antiviral effect of FFYH in vivo with ribavirin and lianhuaqingwen as positive controls. RT-PCR was used to quantify the mRNA transcription of TNF-α, IL-6, IFN-γ, IP10, and IL-1ß mRNA. ELISA was used to examine the expression of inflammatory factors such as TNF-α, IL-6, IFN-γ, IP10, and IL-1ß in sera. The blood parameters were analyzed with auto hematology analyzer. Moreover, the potential mechanism of FFYH against influenza A virus in vivo was also investigated. RESULTS: FFYH showed a broad-spectrum of antiviral activity against H1N1, H3N2, H5N1, H7N9, and H9N2 influenza A viruses. Furthermore, FFYH dose-dependently increased the survival rate, significantly prolonged the median survival time of mice, and markedly reduced lung injury caused by influenza A virus. Also, FFYH significantly improve the sick signs, food taken, weight loss, blood parameters, lung index, and lung pathological changes. Moreover, FFYH could markedly inhibit the inflammatory cytokine expression of TNF-α, IL-6, IFN-γ, IP10, IL-10, and IL-1ß mRNA or protein via inhibition of the TLR7/MyD88/NF-κB signaling pathway in vivo. CONCLUSION: FFYH not only showed a broad-spectrum of anti-influenza virus activity in vitro, but also exhibited a significant protective effect against lethal influenza virus infection in vivo. Furthermore, our results indicated that the in vivo antiviral effect of FFYH against influenza virus may be attributed to suppressing the expression of inflammatory cytokines via regulating the TLR7/MyD88/NF-κB signaling pathway. These findings provide evidence for the clinical treatment of influenza A virus infection with FFYH.
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Antiinflamatorios/farmacología , Antivirales/farmacología , Medicamentos Herbarios Chinos/farmacología , Virus de la Influenza A/efectos de los fármacos , Pulmón/efectos de los fármacos , Glicoproteínas de Membrana/metabolismo , Factor 88 de Diferenciación Mieloide/metabolismo , Infecciones por Orthomyxoviridae/tratamiento farmacológico , Receptor Toll-Like 7/metabolismo , Células A549 , Animales , Citocinas/genética , Citocinas/metabolismo , Modelos Animales de Enfermedad , Perros , Interacciones Huésped-Patógeno , Humanos , Mediadores de Inflamación/metabolismo , Virus de la Influenza A/patogenicidad , Pulmón/inmunología , Pulmón/metabolismo , Pulmón/virología , Células de Riñón Canino Madin Darby , Ratones Endogámicos ICR , FN-kappa B/metabolismo , Infecciones por Orthomyxoviridae/inmunología , Infecciones por Orthomyxoviridae/metabolismo , Infecciones por Orthomyxoviridae/virología , Transducción de Señal , Replicación Viral/efectos de los fármacosRESUMEN
PURPOSE: The aim of this study was to assess whether passive smoking affects clinical outcomes among female patients with knee osteoarthritis after being treated with total knee arthroplasty (TKA). METHODS: The study prospectively enrolled 216 female patients who did not smoke and those patients were classified into three groups in terms of the severity of exposure to environmental tobacco smoke. A three-month follow-up was conducted to assess the physical and mental outcomes between the three groups. The physical outcomes were evaluated by the visual analogue score (VAS), range of motion (ROM), hospital for special surgery (HSS) knee score, and postoperative complications. The mental outcomes were assessed by the anxiety and depression scale (HADS) and medical outcome study short form 36 (SF-36). Subgroup analysis of patients with and without surgical site infection (SSI) was also calculated. RESULTS: Baseline characteristics were similarly distributed between the three groups (P>0.05). Patients in the heavy passive smoking group had a higher VAS and a lower ROM score as compared with patients in the no and mild passive smoking group at discharge (P<0.01), 1 month (P<0.01), and 3 months (P<0.01) after surgery. Patients in the heavy passive smoking group also had a higher rate of HADS more than 8 at postoperative 1 month (P=0.01) and 3 months (P=0.03) and lower SF-36 summary (P<0.01) and HSS score (P<0.01) at postoperative 3 months. Forty-five postoperative complication events were observed during follow-up. Patients in the heavy passive smoking group (8.51%) had the highest SSI rate, followed by patients in the mild (1.82%) and no passive smoking group (0.88%) at discharge (P=0.02) and postoperative 1 month (P=0.03). CONCLUSION: Passive smoking negatively affects TKA among female patients. It may trigger poor pain and functional outcomes, aggravate depression and anxiety, and deteriorate quality of life after discharge from hospital. Avoiding exposure to smoking environment may be beneficial among TKA female patients before and after surgery.
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BACKGROUND: The avian influenza virus (AIV) can cross species barriers and expand its host range from birds to mammals, even humans. Avian influenza is characterized by pronounced activation of the proinflammatory cytokine cascade, which perpetuates the inflammatory response, leading to persistent systemic inflammatory response syndrome and pulmonary infection in animals and humans. There are currently no specific treatment strategies for avian influenza. METHODS: We hypothesized that mesenchymal stromal cells (MSCs) would have beneficial effects in the treatment of H9N2 AIV-induced acute lung injury in mice. Six- to 8-week-old C57BL/6 mice were infected intranasally with 1 × 104 MID50 of A/HONG KONG/2108/2003 [H9N2 (HK)] H9N2 virus to induce acute lung injury. After 30 min, syngeneic MSCs were delivered through the caudal vein. Three days after infection, we measured the survival rate, lung weight, arterial blood gas, and cytokines in both bronchoalveolar lavage fluid (BALF) and serum, and assessed pathological changes to the lungs. RESULTS: MSC administration significantly palliated H9N2 AIV-induced pulmonary inflammation by reducing chemokines and proinflammatory cytokines levels, as well as reducing inflammatory cell recruit into the lungs. Thus, H9N2 AIV-induced lung injury was markedly alleviated in mice treated with MSCs. Lung histopathology and arterial blood gas analysis were improved in mice with H9N2 AIV-induced lung injury following MSC treatment. CONCLUSIONS: MSC treatment significantly reduces H9N2 AIV-induced acute lung injury in mice and is associated with reduced pulmonary inflammation. These results indicate a potential role for MSC therapy in the treatment of clinical avian influenza.
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Lesión Pulmonar Aguda/terapia , Células Madre Mesenquimatosas/citología , Infecciones por Orthomyxoviridae/terapia , Lesión Pulmonar Aguda/virología , Animales , Líquido del Lavado Bronquioalveolar , Quimiocinas/metabolismo , Femenino , Subtipo H9N2 del Virus de la Influenza A , Pulmón/patología , Pulmón/virología , Ratones , Ratones Endogámicos C57BL , Infecciones por Orthomyxoviridae/virología , Neumonía/terapia , Neumonía/virología , Tasa de SupervivenciaRESUMEN
Advances in nanotechnology depend upon expanding the ability to create new and complex materials with well-defined multidimensional mesoscale structures. The creation of hybrid hierarchical structures by combining colloidal organic and inorganic building blocks remains a challenge due to the difficulty in preparing organic structural units of precise size and shape. Here we describe a design strategy to generate controlled hierarchical organic-inorganic hybrid architectures by multistep bottom-up self-assembly. Starting with a suspension of large inorganic nanoparticles, we anchor uniform block copolymer crystallites onto the nanoparticle surface. These colloidally stable multi-component particles can initiate the living growth of uniform cylindrical micelles from their surface, leading to three-dimensional architectures. Structures of greater complexity can be obtained by extending the micelles via addition of a second core-crystalline block copolymer. This controlled growth of polymer micelles from the surface of inorganic particles opens the door to the construction of previously inaccessible colloidal organic-inorganic hybrid structures.
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We investigate the evolution of the electron mobility of two different acceptors, [6,6]-phenyl C71 butyric acid methyl ester (PC71BM) and indene-C60 bisadduct (ICBA), in a poly(3-hexylthiophene) blend solar cell during a prolonged thermal aging process. High electron mobility does not correlate with the best device performance in our study of the P3HT:PC71BM and P3HT:ICBA systems. Very little changes are observed in the polymer crystallinity as a function of time. The evolution of the acceptor appears to be the dominant factor that leads to long-term changes in the device performance. The electron mobility evolves differently in PC71BM and ICBA systems, which highlights the importance of the fullerene molecular structure.
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Electrones , Polímeros/química , Energía Solar , Suministros de Energía Eléctrica , Fulerenos/química , Estructura MolecularAsunto(s)
Electroquímica/métodos , Microscopía de Fuerza Atómica/métodos , Electrólitos , Compuestos Ferrosos/química , Cinética , Sustancias Macromoleculares , Modelos Moleculares , Modelos Teóricos , Conformación Molecular , Proteínas Motoras Moleculares/química , Nitrógeno/química , Oxidación-Reducción , Polímeros/química , Silanos/química , Sulfuros/químicaRESUMEN
In this article, we have investigated the interaction between two poly(benzyl ether) dendrons directly by single-molecule force spectroscopy. For this purpose, one dendron was immobilized on an AFM tip through a poly(ethylene glycol) (PEG) spacer, and the other dendron was anchored on a gold substrate as a self-assembled monolayer. Two dendrons approached and then interacted with each other when the AFM tip and the substrate moved close together. The rupture force between dendrons was measured while the AFM tip and the substrate separated. PEG as a flexible spacer can function as a length window for recognizing the force signals and avoiding the disturbance of the interaction between the AFM tip and the substrate. The interaction between two first-generation dendrons is measured to be about 224 pN at a force loading rate of 40 nN/s. The interaction between second- and first-generation dendrons rises to 315 pN at the same loading rate. Such interactions depend on the force loading rate in the range of several to hundreds of nanonewtons per second, indicating that the rupture between dendrons is a dynamic process. The study of the interaction between surface-bound dendrons of different generations provides a model system for understanding the surface adhesion of molecules with multiple branches. In addition, this multiple-branch molecule may be used to mimic the sticky feet of geckos as a man-made adhesive.
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Pyrene derivatives can absorb onto the surface of carbon nanotubes and graphite particles through pi-pi interactions to functionalize these inorganic building blocks with organic surface moieties. Using single molecule force spectroscopy, we have demonstrated the first direct measurement of the interaction between pyrene and a graphite surface. In particular, we have connected a pyrene molecule onto an AFM tip via a flexible poly(ethylene glycol) (PEG) chain to ensure the formation of a molecular bridge. The pi-pi interaction between pyrene and graphite is thus indicated to be approximately 55 pN with no hysteresis between the desorption and adhesion forces.