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1.
Ecotoxicol Environ Saf ; 280: 116538, 2024 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-38833980

RESUMEN

Methamphetamine (Meth) is a potent psychostimulant with well-established hepatotoxicity. Gut microbiota-derived short-chain fatty acids (SCFAs) have been reported to yield beneficial effects on the liver. In this study, we aim to further reveal the mechanisms of Meth-induced hepatic injuries and investigate the potential protective effects of SCFAs. Herein, mice were intraperitoneally injected with 15 mg/kg Meth to induce hepatic injuries. The composition of fecal microbiota and SCFAs was profiled using 16 S rRNA sequencing and Gas Chromatography/Mass Spectrometry (GC/MS) analysis, respectively. Subsequently, SCFAs supplementation was performed to evaluate the protective effects against hepatic injuries. Additionally, Sigma-1 receptor knockout (S1R-/-) mice and fluvoxamine (Flu), an agonist of S1R, were introduced to investigate the mechanisms underlying the protective effects of SCFAs. Our results showed that Meth activated S1R and induced hepatic autophagy, inflammation, and oxidative stress by stimulating the MAPK/ERK pathway. Meanwhile, Meth disrupted SCFAs product-related microbiota, leading to a reduction in fecal SCFAs (especially Acetic acid and Propanoic acid). Accompanied by the optimization of gut microbiota, SCFAs supplementation normalized S1R expression and ameliorated Meth-induced hepatic injuries by repressing the MAPK/ERK pathway. Effectively, S1R knockout repressed Meth-induced activation of the MAPK/ERK pathway and further ameliorated hepatic injuries. Finally, the overexpression of S1R stimulated the MAPK/ERK pathway and yielded comparable adverse phenotypes to Meth administration. These findings suggest that Meth-induced hepatic injuries relied on the activation of S1R, which could be alleviated by SCFAs supplementation. Our study confirms the crucial role of S1R in Meth-induced hepatic injuries for the first time and provides a potential preemptive therapy.


Asunto(s)
Enfermedad Hepática Inducida por Sustancias y Drogas , Ácidos Grasos Volátiles , Microbioma Gastrointestinal , Metanfetamina , Ratones Noqueados , Receptores sigma , Receptor Sigma-1 , Metanfetamina/toxicidad , Animales , Receptores sigma/metabolismo , Ácidos Grasos Volátiles/metabolismo , Ratones , Microbioma Gastrointestinal/efectos de los fármacos , Masculino , Enfermedad Hepática Inducida por Sustancias y Drogas/prevención & control , Hígado/efectos de los fármacos , Hígado/metabolismo , Ratones Endogámicos C57BL , Estrés Oxidativo/efectos de los fármacos , Heces/química , Heces/microbiología
2.
J Asian Nat Prod Res ; 25(8): 796-802, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36272140

RESUMEN

In this paper, we present the discovery of a novel salicylic acid derivative, moldavica acid A (1), and a new natural dibenzo[b,f]oxepin, moldavica acid B (2), together with four known phenylpropionic acids (3-6) and protocatechuic acid (7) that were isolated from Dracocephalum moldavica L. Their structures were elucidated by comprehensive spectroscopic methods, including infrared and nuclear magnetic resonance. Compound 1 is the first example of salicylic acid linking a carboxylated α-pyrone via an ethyl bridge. Beyond expanding the knowledge of the chemical diversity of D. moldavica, both compounds 1 and 2 were shown to upregulate the expression of Kruppel-like factor 2, which could serve as a prospective therapeutic target for the treatment of atherosclerosis.

3.
Chemistry ; 27(10): 3560-3567, 2021 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-33166095

RESUMEN

In this study, a strategy that can result in the polyaniline (PANI) solely confined within the nanopores of a metal-organic framework (MOF) without forming obvious bulk PANI between MOF crystals is developed. A water-stable zirconium-based MOF, UiO-66-NH2 , is selected as the MOF material. The polymerization of aniline is initiated in the acidic suspension of UiO-66-NH2 nanocrystals in the presence of excess poly(sodium 4-styrenesulfonate) (PSS). Since the pore size of UiO-66-NH2 is too small to enable the insertion of the bulky PSS, the quick formation of pore-confined solid PANI and the slower formation of well dispersed PANI:PSS occur within the MOF crystals and in the bulk solution, respectively. By taking advantage of the resulting homogeneous PANI:PSS polymer solution, the bulk PANI:PSS can be removed from the PANI/UiO-66-NH2 solid by successive washing the sample with fresh acidic solutions through centrifugation. As this is the first time reporting the PANI solely confined in the pores of a MOF, as a demonstration, the obtained PANI/UiO-66-NH2 composite material is applied as the electrode material for supercapacitors. The PANI/UiO-66-NH2 thin films exhibit a pseudocapacitive electrochemical characteristic, and their resulting electrochemical activity and charge-storage capacities are remarkably higher than those of the bulk PANI thin films.

4.
Exp Mol Pathol ; 106: 17-26, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-30439350

RESUMEN

Invadopodia, cancer cell protrusions with proteolytic activity, are functionally associated with active remodeling of the extracellular matrix. Here, we show that the invadopodia-related protein TKS5 is expressed in human pancreatic adenocarcinoma lines, and demonstrate that pancreatic cancer cells depend on TKS5 for invadopodia formation and function. Immunofluorescence staining of human pancreatic cancer cells reveals that TKS5 is a marker of mature and immature invadopodia. We also analyze the co-staining patterns of TKS5 and the commonly used invadopodia marker Cortactin, and find only partial co-localization of these two proteins at invadopodia, with a large fraction of TKS5-positive invadopodia lacking detectable levels of Cortactin. Whereas compelling evidence exist on the role of invadopodia as mediators of invasive migration in cultured cells and in animal models of cancer, these structures have never been detected inside human tumors. Here, using antibodies against TKS5 and Cortactin, we describe for the first time structures strongly resembling invadopodia in various paraffin-embedded human tumor surgical specimens from pancreas and other organs. Our results strongly suggest that invadopodia are present inside human tumors, and warrants further investigation on their regulation and occurrence in surgical specimens, and on the value of TKS5 antibodies as pathological research and diagnostic tools.


Asunto(s)
Proteínas Adaptadoras del Transporte Vesicular/fisiología , Adenocarcinoma/patología , Proteínas de Neoplasias/fisiología , Neoplasias Pancreáticas/patología , Podosomas/fisiología , Adenocarcinoma/química , Adenocarcinoma/cirugía , Adenocarcinoma/ultraestructura , Adulto , Anciano , Línea Celular Tumoral , Cortactina/análisis , Femenino , Técnica del Anticuerpo Fluorescente Directa , Humanos , Masculino , Persona de Mediana Edad , Invasividad Neoplásica , Neoplasias/química , Neoplasias/patología , Neoplasias Pancreáticas/química , Neoplasias Pancreáticas/cirugía , Neoplasias Pancreáticas/ultraestructura , Adhesión en Parafina , Podosomas/química , Podosomas/ultraestructura , Interferencia de ARN , ARN Interferente Pequeño/genética
5.
Pharm Stat ; 17(2): 105-116, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-29297979

RESUMEN

For survival endpoints in subgroup selection, a score conversion model is often used to convert the set of biomarkers for each patient into a univariate score and using the median of the univariate scores to divide the patients into biomarker-positive and biomarker-negative subgroups. However, this may lead to bias in patient subgroup identification regarding the 2 issues: (1) treatment is equally effective for all patients and/or there is no subgroup difference; (2) the median value of the univariate scores as a cutoff may be inappropriate if the sizes of the 2 subgroups are differ substantially. We utilize a univariate composite score method to convert the set of patient's candidate biomarkers to a univariate response score. We propose applying the likelihood ratio test (LRT) to assess homogeneity of the sampled patients to address the first issue. In the context of identification of the subgroup of responders in adaptive design to demonstrate improvement of treatment efficacy (adaptive power), we suggest that subgroup selection is carried out if the LRT is significant. For the second issue, we utilize a likelihood-based change-point algorithm to find an optimal cutoff. Our simulation study shows that type I error generally is controlled, while the overall adaptive power to detect treatment effects sacrifices approximately 4.5% for the simulation designs considered by performing the LRT; furthermore, the change-point algorithm outperforms the median cutoff considerably when the subgroup sizes differ substantially.


Asunto(s)
Selección de Paciente , Medicina de Precisión/mortalidad , Medicina de Precisión/métodos , Bases de Datos Factuales/tendencias , Humanos , Funciones de Verosimilitud , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/mortalidad , Neoplasias Pulmonares/terapia , Medicina de Precisión/tendencias , Tasa de Supervivencia/tendencias , Resultado del Tratamiento
6.
Biom J ; 58(5): 1151-63, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-27073016

RESUMEN

Recently, personalized medicine has received great attention to improve safety and effectiveness in drug development. Personalized medicine aims to provide medical treatment that is tailored to the patient's characteristics such as genomic biomarkers, disease history, etc., so that the benefit of treatment can be optimized. Subpopulations identification is to divide patients into several different subgroups where each subgroup corresponds to an optimal treatment. For two subgroups, traditionally the multivariate Cox proportional hazards model is fitted and used to calculate the risk score when outcome is survival time endpoint. Median is commonly chosen as the cutoff value to separate patients. However, using median as the cutoff value is quite subjective and sometimes may be inappropriate in situations where data are imbalanced. Here, we propose a novel tree-based method that adopts the algorithm of relative risk trees to identify subgroup patients. After growing a relative risk tree, we apply k-means clustering to group the terminal nodes based on the averaged covariates. We adopt an ensemble Bagging method to improve the performance of a single tree since it is well known that the performance of a single tree is quite unstable. A simulation study is conducted to compare the performance between our proposed method and the multivariate Cox model. The applications of our proposed method to two public cancer data sets are also conducted for illustration.


Asunto(s)
Algoritmos , Modelos Biológicos , Medicina de Precisión/métodos , Simulación por Computador , Humanos , Neoplasias/terapia , Riesgo
7.
Environ Res ; 136: 246-52, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25460643

RESUMEN

Acrylamide is present in mainstream cigarette smoke and in some foods prepared at high temperatures. Animal studies have shown that acrylamide exposure alters thyroid function; however, it is not known if this also occurs in humans. The study examined the association between the urinary levels of the acrylamide metabolite and serum thyroid measures in adolescents and young adults. We recruited 793 subjects (mean age, 21.3 years; range, 12-30 years) from a population-based sample of Taiwanese adolescents and young adults to determine if the urinary levels of the acrylamide metabolite N-acetyl-S-(propionamide)-cysteine (AAMA) and the 6 serum thyroid measures are associated. The mean (SD) AAMA were 76.54 (76.42) µg/L. Linear regression analyzes showed a 1-unit increase in natural log AAMA was significantly associated with a decrease in serum free thyroxine (T4) (ng/dL) (ß=-0.041, SE=0.013, p=0.001) after controlling for covariates. Subpopulation analyzes showed AAMA and free T4 were significantly associated with females, age 20-30 years, non-current smokers, and non-alcohol consumers. In conclusion, higher urinary AAMA concentrations were associated with decreased levels of free T4 in this cohort. Further studies are warranted to determine if there is a causal relationship between acrylamide exposure and thyroid function.


Asunto(s)
Acetilcisteína/análogos & derivados , Glándula Tiroides/fisiología , Acetilcisteína/metabolismo , Adolescente , Adulto , Niño , Femenino , Humanos , Masculino , Adulto Joven
8.
Sci Total Environ ; 935: 173285, 2024 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-38772488

RESUMEN

Dietary pollution of Aflatoxin B1 (AFB1) poses a great threat to global food safety, which can result in serious hepatic injuries. Following the widespread use of plastic tableware, co-exposure to microplastics and AFB1 has dramatically increased. However, whether microplastics could exert synergistic effects with AFB1 and amplify its hepatotoxicity, and the underlying mechanisms are still unelucidated. Here, mice were orally exposed to 100 nm polystyrene nanoplastics (NPs) and AFB1 to investigate the influences of NPs on AFB1-induced hepatic injuries. We found that exposure to only NPs or AFB1 resulted in colonic inflammation and the impairment of the intestinal barrier, which was exacerbated by combined exposure to NPs and AFB1. Meanwhile, co-exposure to NPs exacerbated AFB1-induced dysbiosis of gut microbiota and remodeling of the fecal metabolome. Moreover, NPs and AFB1 co-exposure exhibited higher levels of systemic inflammatory factors compared to AFB1 exposure. Additionally, NPs co-exposure further exacerbated AFB1-induced hepatic fibrosis and inflammation, which could be associated with the overactivation of the TLR4/MyD88/NF-κB pathway. Notably, Spearman's correlation analysis revealed that the exacerbation of NPs co-exposure was closely associated with microbial dysbiosis. Furthermore, microbiota from NPs-exposed mice (NPsFMT) partly reproduced the exacerbation of NPs on AFB1-induced systemic and hepatic inflammation, but not fibrosis. In summary, our findings indicate that gut microbiota could be involved in the exacerbation of NPs on AFB1-induced hepatic injuries, highlighting the health risks of NPs.


Asunto(s)
Aflatoxina B1 , Microbioma Gastrointestinal , Hígado , Microplásticos , Poliestirenos , Aflatoxina B1/toxicidad , Animales , Ratones , Microbioma Gastrointestinal/efectos de los fármacos , Poliestirenos/toxicidad , Microplásticos/toxicidad , Hígado/efectos de los fármacos , Enfermedad Hepática Inducida por Sustancias y Drogas , Disbiosis/inducido químicamente , Nanopartículas/toxicidad
9.
Environ Res ; 123: 52-7, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23578827

RESUMEN

BACKGROUND AND OBJECTIVE: Manganese, lead, arsenic and mercury are common neurotoxic metals in the environment. Nonetheless, the relationship between prenatal exposure to low doses of neurotoxic metals and neurodevelopment in children is not clear. The objective of this study was to explore the relationship between in utero exposure to environmental neurotoxic metals and neurodevelopment at 2 years of age. METHODS: The population of this study came from the Taiwan Birth Panel Study. We included 230 pairs of non-smoking mothers without any occupational exposure and their singleton full-term children. The information about exposure during pregnancy was obtained using a structured questionnaire, and the manganese, lead, arsenic and mercury levels in umbilical cord blood samples were analyzed using inductively coupled plasma mass spectrometry. We used the Comprehensive Developmental Inventory for Infants and Toddlers (CDIIT) to evaluate the developmental status of each child at 2 years of age, and we examined the association of in utero exposure to environmental metals and neurodevelopment using linear regression models. RESULTS: The median concentrations of manganese, lead, arsenic and mercury in the cord blood samples in this study were 47.90 µg/L (range, 17.88-106.85 µg/L), 11.41 µg/L (range 0.16-43.22 µg/L), 4.05 µg/L (range, 1.50-12.88 µg/L) and 12.17 µg/L (range, 1.53-64.87 µg/L), respectively. After adjusting for maternal age, infant gender, environmental tobacco smoke during pregnancy and after delivery, Home Observation for Measurement of the Environment Inventory results, and arsenic and mercury levels in cord blood, we found that manganese and lead levels above the 75th percentile had a significant adverse association with the overall (ß=-7.03, SE=2.65, P=0.0085), cognitive (ß=-8.19, SE=3.17, P=0.0105), and language quotients (ß=-6.81, SE=2.73, P=0.0133) of the CDIIT. CONCLUSIONS: In utero exposure to environmental manganese and lead may have an adverse association with neurodevelopment at 2 years of age, and there is an interaction effect between the manganese and lead levels in the cord blood that could aggravate the effect.


Asunto(s)
Desarrollo Infantil/efectos de los fármacos , Plomo/efectos adversos , Manganeso/efectos adversos , Sistema Nervioso/efectos de los fármacos , Efectos Tardíos de la Exposición Prenatal , Adulto , Preescolar , Exposición a Riesgos Ambientales/efectos adversos , Femenino , Humanos , Plomo/sangre , Manganeso/sangre , Sistema Nervioso/crecimiento & desarrollo , Neurotoxinas/efectos adversos , Embarazo , Adulto Joven
10.
Methods Mol Biol ; 2557: 765-784, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36512250

RESUMEN

The architecture of the Golgi apparatus in mammalian cells changes dynamically in response to internal and external cues and may be permanently altered in disease states. Here, we present a method to quantify changes in Golgi morphology using immunofluorescence and confocal microscopy followed by CellProfiler software analysis. This method will assist researchers in evaluating alterations in the Golgi complex morphology of cultured cells under a variety of different experimental conditions.


Asunto(s)
Autoantígenos , Proteínas de la Membrana , Animales , Aparato de Golgi , Técnica del Anticuerpo Fluorescente , Programas Informáticos , Mamíferos
11.
Nat Prod Res ; : 1-7, 2023 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-37154381

RESUMEN

Five isocoumarin derivatives including three new compounds, aspermarolides A-C (1-3), and two known analogues, 8-methoxyldiaporthin (4) and diaporthin (5) were obtained from the culture extract of Aspergillus flavus CPCC 400810. The structures of these compounds were elucidated by spectroscopic methods. The double bond geometry of 1 and 2 were assigned by the coupling constants. The absolute configuration of 3 was determined by electronic circular dichroism experiment. All compounds showed no cytotoxic activities against the two human cancer cells HepG2 and Hela.

12.
Am J Forensic Med Pathol ; 33(1): 19-21, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-20585228

RESUMEN

Purkinje fibers in cardiac conduction tissue during fatal electrocution. A total of 16 Sprague Dawley rats were divided into 2 groups as follows: the electrocution group and the control group.Animals were deeply anesthetized with sodium pentobarbital and, in the electrocution group, all 8 rats underwent a fatal electrical shock (220 v,50 Hz) followed by cervical dislocation. In the control group, all 8 rats underwent execution by cervical dislocation. Following death, hearts were rapidly excised and perfused with 1% paraformaldehyde before tissues of the left ventricular anterior wall (LVAW) were isolated. The microscopic structure of the Purkinje fibers were subsequently analyzed using conventional hematoxylin and eosin staining. A majority of the Purkinje fibers were located in groups among the cardiac muscle of the LVAW. A significant reduction in Purkinje fiber expression was displayed in the electrocution group compared with the control group (P G 0.05).The mean total number of Purkinje fibers for the electrocution and control groups were 59 T 11 and 3287 T 19 cells, respectively (P G 0.05).The estimated number of Purkinje fibers in the LVAW of the control group was significantly greater than observed in the electrocution group(41.09 T 0.24 vs. 0.7375 T 0.14, P G 0.05). The findings of the current study suggest that such a reduction would be reflected in abnormal cardiac conduction and a possible cause of sudden death.


Asunto(s)
Traumatismos por Electricidad/patología , Ramos Subendocárdicos/patología , Animales , Patologia Forense , Ventrículos Cardíacos/patología , Masculino , Microscopía , Ratas , Ratas Sprague-Dawley , Coloración y Etiquetado
13.
Am J Forensic Med Pathol ; 33(3): 215-21, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22182986

RESUMEN

Death due to accidental electrocution occurs frequently. The aim of this study was to investigate alterations in cardiac connexin 43 (Cx43), angiotensin II (Ang II), endothelin 1 (ET-1), and type III collagen associated with fatal electrocution.Twenty-four Sprague-Dawley rats were divided into control, fatal electrocution (220 V, 50 Hz, 60 seconds), and electrical injury (220 V, 50 Hz, 60 seconds) groups. Animals were deeply anesthetized with sodium pentobarbital before each treatment, with the anode connected to the left foreleg and the cathode to the right hindleg, followed by cervical dislocation. Control animals received cervical dislocation alone. Immunohistochemical analysis was performed to evaluate the cardiac protein expression of Cx43, Ang II, ET-1, and type III collagen. Sections were analyzed by digital image analysis.The expression of Cx43 was significantly reduced after fatal electrocution, with the integrated optical density also lower when compared with control (P < 0.05). Expression of both Ang II and ET-1 was significantly increased after fatal electrocution, supported by integrated optical density when compared with control (P < 0.05). But no significant difference was found in type III collagen expression between the fatal electrocution group and the control group.In summary, cardiac protein expression of Cx43, Ang II, and ET-1 was found to be significantly altered with fatal electrocution, suggesting that these 3 proteins may be important underlying mechanisms of death during fatal electrocution. The current findings indicate that such alterations would be reflected in abnormal cardiac function and a possible cause of sudden death.


Asunto(s)
Angiotensina II/metabolismo , Colágeno Tipo III/metabolismo , Traumatismos por Electricidad/metabolismo , Endotelina-1/metabolismo , Miocardio/metabolismo , Animales , Patologia Forense , Inmunohistoquímica , Microscopía/métodos , Ratas , Ratas Sprague-Dawley
14.
Artículo en Inglés | MEDLINE | ID: mdl-35911138

RESUMEN

Purpose: Real-world evidence refers to patient data derived from the healthcare process. In this study, we used National Health Insurance Research Database (NHIRD) assessments and clinical studies of Ge Gen Tang (GGT, ) in patients with common cold to establish a real-world study model of Traditional Chinese Medicine formulae. GGT is widely prescribed for the treatment of common cold in Taiwan, generally in combination with other medicines. The aim of this study was to determine whether a correlation exists between GGT combined with other medicines and an improvement in cold symptoms. We also established a GGT prescription compatibility system by analyzing Taiwan's NHIRD records for GGT prescription patterns in patients with different types of common cold. Materials and Methods: We extracted and analyzed records from the NHIRD for the period 2000-2015 to determine the most common clinical applications of GGT. GGT and GGT with Chuan Xiung Cha Tiao San were most commonly prescribed for common cold, as per NHIRD recommendations. Records for adults aged 20-65 years who were prescribed GGT for the treatment of common cold (Diagnosis Code ICD-9-460) were included in this study. We assessed the following indicators of the common cold, before and after treatment with GGT: nasal congestion, cough, runny nose, sneezing, sore throat, hoarseness, stiff shoulder, headache, and general physical condition. Results: The cold symptom scores before and after taking the GGT prescriptions significantly differed in the 29 volunteers. The 29 volunteers reported a significantly lower headache severity score after medication than before medication (p < 0.004). Furthermore, patient scores for general physical condition decreased significantly (p < 0.01) after medication.

15.
Opt Lett ; 36(13): 2563-5, 2011 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-21725480

RESUMEN

FeCo/NiO half-shell arrays were fabricated based on the periodic monolayer polystyrene spheres. The two-dimensional magnetic periodic arrays form well-defined photonic crystals with pronounced stop bands. Quite interestingly, it is found that the stop bands can be tuned by an external magnetic field. The underlying mechanism is attributed to the controllable dielectric constant of the magnetic FeCo film under an applied magnetic field. The results shown here may open up an avenue for magnetically tunable photonic crystal stop bands, which may be useful for the creation of new magneto-optical devices.

16.
Opt Lett ; 36(4): 514-6, 2011 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-21326440

RESUMEN

We demonstrate magnetically tunable surface plasmon resonance based on a composite consisting of noble metal nanoparticles and ferromagnetic thin film. We found that both the frequency and linewidth of the localized surface plasmon resonance can be manipulated by applying an external magnetic field. The underlying mechanism is attributed to the variation of the dielectric constant in the ferromagnetic thin film resulting from the change of magnetization. Our result shown here paves an alternative route for manipulation of the characteristics of the surface plasmon resonance, which may serve as a new design concept for the development of magneto-optical devices.

17.
ACS Appl Mater Interfaces ; 13(14): 16418-16426, 2021 Apr 14.
Artículo en Inglés | MEDLINE | ID: mdl-33818075

RESUMEN

In this study, nanocrystals of a cerium-based metal-organic framework (Ce-MOF), Ce-MOF-808, are directly grown on the surface of carboxylic acid-functionalized carbon nanotubes (CNTs) by a facile one-step solvothermal synthesis method. Ce-MOF-CNT nanocomposites with various Ce-MOF-to-CNT ratios are synthesized, and their crystallinity, morphology, porosity, and electrical conductivity are examined. The redox-hopping and electrochemical behaviors of the pristine Ce-MOF in aqueous electrolytes are investigated, suggesting that the pristine Ce-MOF is electrochemically active but possesses a limited charge-transport behavior. As a demonstration, all the Ce-MOF, CNT, and nanocomposites are used as active materials for application in aqueous-based supercapacitors. The capacitive performance of the CNT can be significantly boosted with the help of redox-active Ce-MOF-808 nanocrystals.

18.
Nat Commun ; 12(1): 888, 2021 02 09.
Artículo en Inglés | MEDLINE | ID: mdl-33563962

RESUMEN

The design principle of establishing an intracellular protein gradient for asymmetric cell division is a long-standing fundamental question. While the major molecular players and their interactions have been elucidated via genetic approaches, the diversity and redundancy of natural systems complicate the extraction of critical underlying features. Here, we take a synthetic cell biology approach to construct intracellular asymmetry and asymmetric division in Escherichia coli, in which division is normally symmetric. We demonstrate that the oligomeric PopZ from Caulobacter crescentus can serve as a robust polarized scaffold to functionalize RNA polymerase. Furthermore, by using another oligomeric pole-targeting DivIVA from Bacillus subtilis, the newly synthesized protein can be constrained to further establish intracellular asymmetry, leading to asymmetric division and differentiation. Our findings suggest that the coupled oligomerization and restriction in diffusion may be a strategy for generating a spatial gradient for asymmetric cell division.


Asunto(s)
División Celular Asimétrica , Escherichia coli/citología , Escherichia coli/metabolismo , Espacio Intracelular/metabolismo , Bacillus subtilis/genética , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Caulobacter crescentus/genética , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Diferenciación Celular , Polaridad Celular , Escherichia coli/genética , Regulación Bacteriana de la Expresión Génica
19.
Am J Emerg Med ; 28(3): 275-83, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-20223383

RESUMEN

STUDY OBJECTIVE: To improve the management quality and monitoring for common pediatric illnesses in the general emergency department (ED), we examined the effect of physician specialty training on medical resource use and patient outcomes. METHODS: This was a retrospective cohort review of visits by children less than 18 years to the ED of 2 university-affiliated teaching hospitals. Clinical management by 2 groups (emergency physicians [EPs] and pediatricians each working 168 h/wk) was compared with respect to demographics, ED resource use, short-term outcome, disposition, direct ED costs for each visit, and frequency of radiographic and laboratory test use. The effects of medical decision making on resource use was assessed by comparing costs of radiographic studies, laboratory studies, and medication. RESULTS: Between-group differences in mean patient age, sex, and triage category were insignificant. Compared to pediatricians, EPs used radiographic and laboratory studies more frequently (respectively, 10.1% and 3.8% higher frequency and 90.5% and 7.6% higher cost) and less medication (12.5% lower cost). Patients managed by EPs had longer ED length of stay (LOS), higher admission rates to general wards, and shorter LOS per hospitalization but similar 72-hour revisit rates, needed more frequent referral for medical reasons, and left more frequently against medical advice. CONCLUSION: Emergency physicians spent more time and medical resources and admitted patients at a higher rate. Emergency physicians and pediatricians managed critical patients similarly.


Asunto(s)
Servicio de Urgencia en Hospital/organización & administración , Pediatría/educación , Pautas de la Práctica en Medicina/estadística & datos numéricos , Adolescente , Distribución de Chi-Cuadrado , Niño , Preescolar , Femenino , Hospitales de Enseñanza , Humanos , Lactante , Recién Nacido , Tiempo de Internación/estadística & datos numéricos , Masculino , Admisión del Paciente/estadística & datos numéricos , Estudios Retrospectivos , Estadísticas no Paramétricas , Triaje
20.
Chem Commun (Camb) ; 56(79): 11763-11766, 2020 Oct 11.
Artículo en Inglés | MEDLINE | ID: mdl-32930153

RESUMEN

A redox-active vanadium-based polyoxometalate, V10O28, was post-synthetically immobilized into a water-stable zirconium-based metal-organic framework, NU-902. The adsorbed V10O28 in NU-902 renders charge hopping in the framework in aqueous electrolytes, and the obtained V10O28@NU-902 can be used as a heterogeneous electrocatalyst for electrochemical dopamine sensors.


Asunto(s)
Aniones/química , Dopamina/análisis , Estructuras Metalorgánicas/química , Polielectrolitos/química , Vanadatos/química , Adsorción , Catálisis , Dopamina/química , Técnicas Electroquímicas/métodos , Límite de Detección , Oxidación-Reducción
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