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Kawasaki disease (KD) is an acute self-limiting vasculitis with coronary complications, usually occurring in children. The incidence of KD in children is increasing year by year, mainly in East Asian countries, but relatively stably in Europe and America. Although studies on KD have been reported, the pathogenesis of KD is unknown. With the development of high-throughput sequencing technology, growing number of regulatory noncoding RNAs (ncRNAs) including microRNA (miRNA), long noncoding RNA (lncRNA), and circular RNA (circRNA) have been identified to involved in KD. However, the role of ncRNAs in KD has not been comprehensively elucidated. Therefore, it is significative to study the regulatory role of ncRNA in KD, which might help to uncover new and effective therapeutic strategies for KD. In this review, we summarize recent studies on ncRNA in KD from the perspectives of immune disorders, inflammatory disorders, and endothelial dysfunction, and highlight the potential of ncRNAs as therapeutic targets for KD.
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MicroRNAs , Síndrome de Linfonodos Mucocutâneos , RNA Longo não Codificante , Criança , Humanos , MicroRNAs/genética , Síndrome de Linfonodos Mucocutâneos/genética , RNA Circular , RNA Longo não Codificante/genética , RNA não Traduzido/genéticaRESUMO
Currently, several types of inhalable liposomes have been developed. Among them, liposomal pressurized metered-dose inhalers (pMDIs) have gained much attention due to their cost-effectiveness, patient compliance, and accurate dosages. However, the clinical application of liposomal pMDIs has been hindered by the low stability, i.e., the tendency of the aggregation of the liposome lipid bilayer in hydrophobic propellant medium and brittleness under high mechanical forces. Biomineralization is an evolutionary mechanism that organisms use to resist harsh external environments in nature, providing mechanical support and protection effects. Inspired by such a concept, this paper proposes a shell stabilization strategy (SSS) to solve the problem of the low stability of liposomal pMDIs. Depending on the shell material used, the SSS can be classified into biomineralization (biomineralized using calcium, silicon, manganese, titanium, gadolinium, etc.) biomineralization-like (composite with protein), and layer-by-layer (LbL) assembly (multiple shells structured with diverse materials). This work evaluated the potential of this strategy by reviewing studies on the formation of shells deposited on liposomes or similar structures. It also covered useful synthesis strategies and active molecules/functional groups for modification. We aimed to put forward new insights to promote the stability of liposomal pMDIs and shed some light on the clinical translation of relevant products.
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Biomineralização , Lipossomos , Humanos , Inaladores Dosimetrados , Administração por InalaçãoRESUMO
BACKGROUND: Gene therapy for lung cancer has emerged as a novel tumor-combating strategy for its superior tumor specificity, low systematical toxicity and huge clinical translation potential. Especially, the applications of microRNA shed led on effective tumor ablation by directly interfering with the crucial gene expression, making it one of the most promising gene therapy agents. However, for lung cancer therapy, the microRNA treatment confronted three bottlenecks, the poor tumor tissue penetration effect, the insufficient lung drug accumulation and unsatisfied gene transfection efficiency. To address these issues, an inhalable RGD-TAT dual peptides-modified cationic liposomes loaded with microRNA miR-34a and gap junction (GJ) regulation agent all-trans retinoic acid (ATRA) was proposed, which was further engineered into dry powder inhalers (DPIs). RESULTS: Equipped with a rough particle surface and appropriate aerodynamic size, the proposed RGD-TAT-CLPs/ARTA@miR-34a DPIs were expected to deposit into the deep lung and reach lung tumor lesions guided by targeting peptide RGD. Assisted by cellular transmembrane peptides TAT, the RGD-TAT-CLPs/ARTA@miR-34a was proven to be effectively internalized by cancer cells, enhancing gene transfection efficiency. Then, the GJ between tumor cells was upregulated by ARTA, facilitating the intercellular transport of miR-34a and boosting the gene expression in the deep tumor. CONCLUSION: Overall, the proposed RGD-TAT-CLPs/ARTA@miR-34a DPIs could enhance tumor tissue penetration, elevate lung drug accumulation and boost gene transfection efficiency, breaking the three bottlenecks to enhancing tumor elimination in vitro and in vivo. We believe that the proposed RGD-TAT-CLPs/ARTA@miR-34a DPIs could serve as a promising pulmonary gene delivery platform for multiple lung local disease treatments.
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Neoplasias Pulmonares , MicroRNAs , Humanos , Lipossomos , Neoplasias Pulmonares/terapia , MicroRNAs/genética , MicroRNAs/metabolismo , Pulmão/metabolismo , Oligopeptídeos , Junções Comunicantes/metabolismo , Genes Neoplásicos , Linhagem Celular TumoralRESUMO
This study explored whether using a coal or biomass stove for cooking was associated with a greater risk of red blood cell (RBC) folate insufficiency among pregnant women compared to using clean energy. A researcher-designed questionnaire was used to collect information on exposure-related factors and confounding factors. RBC folate concentrations were examined by microbiological assay. Binary logistic regression analysis was used to identify factors related to RBC folate insufficiency. The use of coal or firewood for cooking was associated with an increased risk of RBC folate insufficiency (<906 nmol/L) compared to gas. In subgroup analyses, associations between the use of polluting cooking fuels and folate insufficiency were positive for both urban and rural residents and statistically significant for rural women. Efforts to promote the use of clean energy and proper ventilation, especially in rural areas, are recommended to improve the health of pregnant women and their offspring.
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Poluição do Ar em Ambientes Fechados , Gestantes , Humanos , Feminino , Gravidez , Ácido Fólico/análise , Poluição do Ar em Ambientes Fechados/efeitos adversos , Poluição do Ar em Ambientes Fechados/análise , Carvão Mineral/toxicidade , Culinária , China/epidemiologiaRESUMO
Intranasal drug delivery system is a non-invasive drug delivery route with the advantages of no first-pass effect, rapid effect and brain targeting. It is a feasible alternative to drug delivery via injection, and a potential drug delivery route for the central nervous system. However, the nasal physiological environment is complex, and the nasal delivery system requires "integration of medicine and device". Its delivery efficiency is affected by many factors such as the features and formulations of drug, delivery devices and nasal cavity physiology. Some strategies have been designed to improve the solubility, stability, membrane permeability and nasal retention time of drugs. These include the use of prodrugs, adding enzyme inhibitors and absorption enhancers to preparations, and new drug carriers, which can eventually improve the efficiency of intranasal drug delivery. This article reviews recent publications and describes the above mentioned aspects and design strategies for nasal intranasal drug delivery systems to provide insights for the development of intranasal drug delivery systems.
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Portadores de Fármacos , Sistemas de Liberação de Medicamentos , Administração Intranasal , Preparações Farmacêuticas , Encéfalo , Cavidade Nasal/fisiologia , Mucosa NasalRESUMO
Thiodiglycolic acid (TDGA) is a biomarker for monitoring vinyl chloride exposure. Exploring a facile, rapid and precise analysis technology to quantify TDGA is of great significance. In this research, we demonstrate a fluorescent sensor based on dual-emissive UiO-66 for TDGA detection. This ratiometric fluorescent material named C460@Tb-UiO-66-(COOH)2 was designed and synthesized by introducing organic dye 7-diethylamino-4-methylcoumarin (C460) and Tb3+ into UiO-66-(COOH)2. The as-obtained C460@Tb-UiO-66-(COOH)2 samples showed highly selective recognition, excellent anti-interference and rapid response characteristics for the recognition of TDGA. The detection limit is 0.518 mg·mL-1, which is much lower than the threshold of 20 mg·mL-1 for a healthy person. In addition, the mechanism of TDGA-induced fluorescence quenching is discussed in detail. This sensor is expected to detect TDGA content in human urine.
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Cloreto de Vinil , Biomarcadores/urina , Humanos , Estruturas Metalorgânicas , Ácidos Ftálicos , TioglicolatosRESUMO
Carriers play an important role in improving the aerosolization performance of dry powder inhalers (DPIs). Despite that intensive attention had been paid to the establishment of the advanced carriers with controllable physicochemical properties in recent years, the design and optimization of carrier-based DPIs remain an empiricism-based process. DPIs are a powder system of complex multiphase, and thus their physicochemical properties cannot fully explain the powder behavior. A comprehensive exposition of powder properties is demanded to build a bridge between the physicochemical properties of carriers and the aerosolization performance of DPIs. In this study, an FT-4 powder rheometer was employed to explore the powder properties, including dynamic flow energy, aeration, and permeability of the chitosan-mannitol binary carriers (CMBCs). CMBCs were self-designed as an advanced carrier with controllable surface roughness to obtain enhanced aerosolization performance. The specific mechanism of CMBCs to enhance the aerosolization performance of DPIs was elaborated based on the theory of pulmonary delivery processes by introducing powder properties. The results exhibited that CMBCs with appropriate surface roughness had lower special energy, lower aeration energy, and higher permeability. It could be predicted that CMBC-based DPIs had greater tendency to fluidize and disperse in airflow, and the lower adhesion force between particles enabled drugs to be detached from the carrier to achieve higher fine particle fractions. The specific mechanism on how physicochemical properties influenced the aerosolization performance during the pulmonary delivery processes could be figured out with the introduction of powder properties.
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Quitosana , Inaladores de Pó Seco , Administração por Inalação , Aerossóis/química , Portadores de Fármacos/química , Excipientes/química , Manitol/química , Tamanho da Partícula , Pós/químicaRESUMO
A spray dressing based on lyotropic liquid crystalline (LLC) with adjustable crystalline lattices was investigated in this study. It possesses water-triggering phase transition property and ease of spraying on wound, as well as stable drug encapsulation and controllable drug release. When it comes to wound with exudate, adequate water absorption and sustainable mechanical strength after water absorption was important for a good dressing, while most of the normal LLC dressings were still unable to meet such standards. Herein, a type of hyaluronic acid (HA)-incorporated LLC-based spray dressing (HLCSD) was developed to overcome the above limitations. After comparing HAs with different molecular weights (MWs) and concentrations, 3% HA with MW of 800~1000 kD was chosen as an ideal amount of excipients to add into the HLCSD. The water absorption of HLCSD precursor increased by 150% with the appearance of enlarged water channels. The complex modulus of HLCSD gel also increased from 1 to 100 kPa, which suggested lasting wound coverage and good patient compliance when used clinically. The spraying and phase transition properties of HLCSD was studied and showed acceptable changes. Moreover, good safety comparable with the commercial product Purilon® was also demonstrated in an in vivo acute skin irritation test. Thus, the improved HLCSD was a promising dressing for exudation wound treatment.
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Cristais Líquidos , Água , Bandagens , Humanos , Ácido Hialurônico , CicatrizaçãoRESUMO
Anthracyclines, such as doxorubicin (DOX), are well known for their high efficacy in treating multiple cancers, but their clinical usage is limited due to their potential to induce fatal cardiotoxicity. Such detrimental effects significantly impact the overall physical condition or even induce the morbidity and mortality of cancer survivors. Therefore, it is extremely important to understand the mechanisms of DOX-induced cardiotoxicity to develop methods for the early detection of cytotoxicity and therapeutic applications. Studies have shown that many molecular events are involved in DOX-induced cardiotoxicity. However, the precise mechanisms are still not completely understood. Recently, noncoding RNAs (ncRNAs) have been extensively studied in a diverse range of regulatory roles in cellular physiological and pathological processes. With respect to their roles in DOX-induced cardiotoxicity, microRNAs (miRNAs) are the most widely studied, and studies have focused on the regulatory roles of long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs), which have been shown to have significant functions in the cardiovascular system. Recent discoveries on the roles of ncRNAs in DOX-induced cardiotoxicity have prompted extensive interest in exploring candidate ncRNAs for utilization as potential therapeutic targets and/or diagnostic biomarkers. This review presents the frontier studies on the roles of ncRNAs in DOX-induced cardiotoxicity, addresses the possibility and prospects of using ncRNAs as diagnostic biomarkers or therapeutic targets, and discusses the possible reasons for related discrepancies and limitations of their use.
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Cardiotoxicidade/metabolismo , Doxorrubicina/toxicidade , MicroRNAs/metabolismo , RNA Circular/metabolismo , RNA Longo não Codificante/metabolismo , Animais , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Biomarcadores/metabolismo , Cardiotoxicidade/tratamento farmacológico , Humanos , MicroRNAs/uso terapêuticoRESUMO
Solid lipid nanoparticles (SLN) have been widely used in a variety of drug delivery routes, which have the outstanding advantage of controlled drug release. The release of SLN is dominated by many factors, among which the particle size of SLN is a critical one. The aim of this project was to explore the relationship between drug release profile and particle size of SLN. SLN were synthesized via the hot high-pressure homogenization (HPH) method, budesonide (BUD) was used as the model drug, and BUD-SLN1-BUD-SLN4 with increasing particle size was obtained, i.e. 120, 240, 360, and 480 nm. The prepared SLN has good encapsulation efficiency, drug loading capacity, and stability. In vitro release behavior studies showed that the cumulative release of BUD-SLN in Tris-Maleate (Tris-M) media was negligible, while that in Tris-M plus pancreatin media or Tris-M-ethanol media obeyed Ritger-Peppas model or first-order kinetic model, respectively. Noticeably, the release behavior of SLN was to some extent related to the average particle size of SLN, but the correlation was insignificant when the intersection degree of particle size distribution was great. This study provides a new idea for the understanding of in vitro release of SLN and has a certain referencing value for the research and development of novel nanomedicines.
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Lipídeos , Nanopartículas , Portadores de Fármacos , Lipossomos , Tamanho da PartículaRESUMO
BACKGROUND: Lipin-1, encoded by LPIN1 gene, serves as an enzyme and a transcriptional co-regulator to regulate lipid metabolism and mitochondrial respiratory chain. Autosomal recessive mutations in LPIN1 were recognized as one of the most common causes of pediatric recurrent rhabdomyolysis in western countries. However, to date, there were only a few cases reported in Asian group. This study aims to report the first pediatric case of recurrent rhabdomyolysis with a novel LPIN1 mutation in China mainland in order to raise the awareness of both pediatricians and patients. CASE PRESENTATIONS: Here we report a Chinese pediatric case of recurrent rhabdomyolysis with compound heterozygous variants (p.Arg388* and p.Arg810Cys) in the LPIN1 gene. The c.2428C > T was a novel missense variant involved Arg-to-Cys substitution at position 810 (p.Arg810Cys), located in the highly conserved region which predicted to be damaging by multiple algorithms. The patient manifested as cola-colored urine, muscle weakness and tenderness, as well as acute kidney injury with peak blood creatine kinase level 109,570 U/l in 19-month old. In his second episode of 9 years old, the symtoms were relatively milder with peak creatine kinase level 50,948 U/l. He enjoyed quite normal life between the bouts but slightly elevation of serum creatine kinase level during the fever or long-term exercises. Prolonged weight training combined with calorie deprivation were speculated to be the triggers of his illness. Prompt symptomatic therapy including fluid therapy and nutritional support was given and the patient recovered soon. CONCLUSIONS: LPIN1-related rhabdomyolysis is still quite new to physicians due to its seemly low-incidence especially in Asian countries. In the future, more active genetic test strategy and detailed prophylactic care education should be taken in patients with severe recurrent rhabdomyolysis, who are the high risk group of LPIN1 genetic defects.
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Fosfatidato Fosfatase , Rabdomiólise , Ásia , Criança , China , Exercício Físico , Humanos , Masculino , Fosfatidato Fosfatase/genética , Rabdomiólise/diagnóstico , Rabdomiólise/genéticaRESUMO
Calcitriol, as the biologically active form of vitamin D3, is essential for patients with renal osteopathy. The solubilization, stabilization, and content uniformity are key issues in its formulation development. In our previous study, the incomplete release of calcitriol was solved by using the hybrid lipid-based solid dispersion (SD) for calcitriol. However, good stability and content uniformity are still urgently needed. In this study, solid lipid with antioxidant properties and liquid lipid compatible with calcitriol were employed as hybrid lipid carrier (HLC) to establish a solid dispersion. Moreover, the content uniformity of tablets with hybrid lipid carrier based SDs (HLCTs) was further guaranteed due to the multi-dispersion of calcitriol in HLC, solidification, and blank granules. Additionally, the compression of the blank granules was adjusted by the water content. The mixing method of calcitriol-containing and blank granules was also optimized. The obtained HLCTs were evaluated for hardness, disintegration time, in vitro drug dissolution, content uniformity, and stability. Satisfactory HLCTs were developed successfully in this study with superior content uniformity and better stability than the commercial soft capsule (Rocaltrol®). It was proved to be a promising formulation for drugs with poor water-solubility, instability to oxygen and heat, and dose-related toxicity.
Assuntos
Conservadores da Densidade Óssea/síntese química , Calcitriol/síntese química , Portadores de Fármacos/síntese química , Composição de Medicamentos/métodos , Conservadores da Densidade Óssea/administração & dosagem , Conservadores da Densidade Óssea/farmacocinética , Calcitriol/administração & dosagem , Calcitriol/farmacocinética , Portadores de Fármacos/administração & dosagem , Portadores de Fármacos/farmacocinética , Liberação Controlada de Fármacos/fisiologia , Estabilidade de Medicamentos , ComprimidosRESUMO
OBJECTIVE: To analyze the clinical effect of budesonide/fomoterol combined with montelukast in the treatment of chronic persistent asthma. METHODS: Ninety-four patients with asthma who came to our hospital for treatment from April 2017 to April 2019 were randomly divided into control group and observation group, with 47 patients in each group. The control group was treated with budesonide/formoterol, and the observation group was treated with montelukast on the basis of the control group. The treatment effect of the two groups was observed and compared. RESULTS: The total efficacy rate of the observation group was significantly higher than that of the control group (P<0.05); the daytime symptom score and nighttime symptom score of the observation group were significantly higher than those of the control group (P<0.05). The pulmonary function indexes of the two groups after treatment were significantly higher than that before treatment, and the improvement of the observation group was more significant (P<0.05); the FeNO and EO levels of the observation group after treatment were superior to those of the control group, and the difference was statistically significant (P<0.05). CONCLUSION: Budesonide/formoterol powder inhalation combined with montelukast can effectively improve the lung function, reduce the level of inflammatory factors, and accelerate the regression of symptoms in the treatment of chronic persistent asthma. It is worth clinical application.
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To minimize the gastric and esophageal injury effect, a system to deliver doxycycline hyclate (DOXY) to the duodenum area is needed. DOXY-containing modified-release oral pellets (DMOP) coated with hydroxypropyl methylcellulose phthalate HP-55 (HPMCP HP-55) and hydroxypropyl methylcellulose E15 (HPMC E15) appear to be a reasonable choice. This coating layer dissolves at pH 5.5, which is the pH of the duodenum, but not at a gastric pH (1.2). The formulation and preparation of DMOP were optimized, and a scale-up test was performed. The results showed that the production reproducibility was acceptable, and the quality of DMOP well met the standards of Chinese Pharmacopeia (Ch.P, 2015 edition). Notably, the accumulated DOXY release was lower than 50% at pH 1.2 (20 min) and higher than 85% at pH 5.5, which met the USP40-NF35 standard for DOXY modified-release formulations. Moreover, the storage stability of DMOP with different packages was investigated by stress testing, accelerated and long-term testings. The stability of DMOP was maintained up to 12 months, in terms of DOXY content and in vitro release behavior. The results seem to suggest that DMOP could be a promising duodenum delivery system.
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Doxiciclina/administração & dosagem , Sistemas de Liberação de Medicamentos/métodos , Administração Oral , Implantes de Medicamento/administração & dosagem , Implantes de Medicamento/química , Liberação Controlada de Fármacos , Estabilidade de Medicamentos , Concentração de Íons de Hidrogênio , Derivados da Hipromelose/química , Metilcelulose/análogos & derivados , Metilcelulose/química , Tamanho da Partícula , Comprimidos com Revestimento Entérico/administração & dosagem , Comprimidos com Revestimento Entérico/químicaRESUMO
Folate insufficiency during the periconceptional period increases the risk of neural tube defects (NTDs) in offspring, and folic acid supplementation substantially reduces the risk. Widespread large-scale folic acid supplementation (0.4-mg folic acid tablet) has been adopted as a main strategy to prevent NTDs in China since 2009. We examined folate concentrations in plasma and red blood cells (RBCs) of pregnant women and the factors associated with blood folate concentrations in a population with a high prevalence of NTDs in northern China. A cross-sectional survey was conducted in 2014, and 1,107 pregnant women were recruited from 11 county or city maternal and child health centres across Shanxi province. Microbiological assays were used to determine folate concentrations. Factors associated with blood folate insufficiency were identified. The median (25th and 75th percentiles) folate concentrations were 28.4 (17.6, 45.2) nmol L-1 and 1,001.2 (658.7, 1,402.5) nmol L-1 in plasma and RBCs, respectively. According to the proposed RBC (906 nmol L-1 ) concentrations for optimal NTD prevention, 42.4% participants had RBC folate insufficiency. Rural women had a higher proportion of folate insufficiency than urban women. Folic acid supplementation was the only factor associated with RBC folate insufficiency. A large proportion of women had RBC folate concentrations that are not optimal for the prevention of NTDs despite free access to folic acid supplements. Actions that aim to improve folic acid supplementation compliance are needed to reach the full potential of the nationwide folic acid supplementation programme in terms of NTD prevention.
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Deficiências Nutricionais , Ácido Fólico/sangue , Ácido Fólico/uso terapêutico , Complicações na Gravidez , Adulto , China/epidemiologia , Estudos Transversais , Deficiências Nutricionais/tratamento farmacológico , Deficiências Nutricionais/prevenção & controle , Suplementos Nutricionais , Feminino , Promoção da Saúde , Humanos , Gravidez , Complicações na Gravidez/tratamento farmacológico , Complicações na Gravidez/prevenção & controle , Adulto JovemRESUMO
microRNAs (miRNAs) are non-coding RNAs that function as post-transcriptional regulators of cardiac development and cardiovascular diseases. Single nucleotide polymorphisms (SNPs) in miRNA genes are a novel class of genetic variations in the human genome that confer the risk of cardiovascular diseases. Here, we identified a polymorphism AâG (rs3746444) in miR-499 precursor (pre-miR-499) that affects the maturation of miR-499-5p and alters its antiapoptotic function by converting stable A-U base pair to wobble G-U base pair in pre-miR-499 secondary structure. Furthermore, our results showed that the concentrations of plasma miR-499-5p could be correlated with myocardial infarction (MI) and heart failure (HF) patients in comparison with control subjects and polymorphism rs3746444 in miR-499 could influence its abundance in plasma. Finally, our results also showed that the variant of polymorphism in miR-499 influenced the severity of the myocardial infarction significantly. This is the first report to highlight the biological significance of this polymorphism on the maturation of miR-499-5p and its antiapoptotic role during MI. These findings may pave a way to better understand the individual variability based on miRNA SNPs in heart diseases and may contribute to better treatment for disease severity on a personalized level.
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Predisposição Genética para Doença , Insuficiência Cardíaca/genética , MicroRNAs/genética , Infarto do Miocárdio/genética , Idoso , Apoptose/genética , Povo Asiático/genética , Feminino , Regulação da Expressão Gênica , Estudos de Associação Genética , Insuficiência Cardíaca/sangue , Insuficiência Cardíaca/fisiopatologia , Humanos , Masculino , MicroRNAs/sangue , Pessoa de Meia-Idade , Infarto do Miocárdio/sangue , Infarto do Miocárdio/patologia , Conformação de Ácido Nucleico , Polimorfismo de Nucleotídeo Único/genéticaRESUMO
The objective of this study was to perform the in vitro and in vivo validation of an endotracheal aerosolization (ETA) device (HRH MAG-4, HM). Solid lipid nanoparticle suspension (SLNS) formulations with particle sizes of approximately 120, 240, 360, and 480 nm were selected as model nanoparticle suspensions for the validation. The emission rate (ER) of the in vitro aerosolization and the influence of aerosolization on the physicochemical properties were investigated. A high ER of up to 90% was obtained, and no significant alterations in physicochemical properties were observed after the aerosolization. The pulmonary deposition of model drug budesonide in Sprague-Dawley rats was determined to be approximately 80%, which was satisfactory for pulmonary delivery. Additionally, a fluorescent probe with aggregation-caused quenching property was encapsulated in SLNS formulations for in vivo bioimaging, after excluding the effect of aerosolization on its fluorescence spectrum. It was verified that SLNS formulations were deposited in the lung region. The results demonstrated the feasibility and reliability of the HM device for ETA in laboratory investigation.
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Budesonida/administração & dosagem , Portadores de Fármacos/química , Corantes Fluorescentes/administração & dosagem , Pulmão/metabolismo , Nebulizadores e Vaporizadores , Administração por Inalação , Animais , Budesonida/farmacocinética , Composição de Medicamentos/métodos , Estudos de Viabilidade , Microscopia Intravital/métodos , Lipídeos/química , Masculino , Microscopia de Fluorescência/métodos , Nanopartículas/química , Tamanho da Partícula , Ratos , Ratos Sprague-Dawley , Reprodutibilidade dos Testes , Suspensões , Distribuição Tecidual , TraqueiaRESUMO
Planar heterojunction perovskite solar cells with a high efficiency up to 17.76% are fabricated by modifying the compact TiO2 (c-TiO2) with a [6,6]-phenyl-C61-butyric acid (PCBA) monolayer. High quality CH3NH3PbI3 films can be easily fabricated on PCBA-modified c-TiO2 substrates by a one-step solution processing method. Significant improvements of the device parameters are observed after PCBA modification. A high open-circuit voltage (Voc) of 1.16 V has been achieved, indicating that the PCBA monolayer can act as a hole blocking layer to reduce the trap site density atop the c-TiO2 and the hole recombination at the c-TiO2 /perovskite interface. The enhancement of the fill factor, as well as the partial quenching of the fluorescence of perovskite after modification with PCBA, reveals that the charge extraction is improved.
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The stochastic Hodgkin-Huxley model is one of the best-known examples of piecewise deterministic Markov processes (PDMPs), in which the electrical potential across a cell membrane, V(t), is coupled with a mesoscopic Markov jump process representing the stochastic opening and closing of ion channels embedded in the membrane. The rates of the channel kinetics, in turn, are voltage-dependent. Due to this interdependence, an accurate and efficient sampling of the time evolution of the hybrid stochastic systems has been challenging. The current exact simulation methods require solving a voltage-dependent hitting time problem for multiple path-dependent intensity functions with random thresholds. This paper proposes a simulation algorithm that approximates an alternative representation of the exact solution by fitting the log-survival function of the inter-jump dwell time, H(t), with a piecewise linear one. The latter uses interpolation points that are chosen according to the time evolution of the H(t), as the numerical solution to the coupled ordinary differential equations of V(t) and H(t). This computational method can be applied to all PDMPs. Pathwise convergence of the approximated sample trajectories to the exact solution is proven, and error estimates are provided. Comparison with a previous algorithm that is based on piecewise constant approximation is also presented.
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Performance enhancement of polymer solar cells (PSCs) is achieved by expanding the absorption of the active layer of devices. To better match the spectrum of solar radiation, two polymers with different band gaps are used as the donor material to fabricate ternary polymer cells. Ternary blend PSCs exhibit an enhanced short-circuit current density and open-circuit voltage in comparison with the corresponding HD-PDFC-DTBT (HD)- and DT-PDPPTPT (DPP)-based binary polymer solar cells, respectively. Ternary PSCs show a power conversion efficiency (PCE) of 6.71%, surpassing the corresponding binary PSCs. This work demonstrates that the fabrication of ternary PSCs by using two polymers with complementary absorption is an effective way to improve the device performance.