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1.
Proc Natl Acad Sci U S A ; 121(4): e2312556121, 2024 Jan 23.
Artículo en Inglés | MEDLINE | ID: mdl-38227655

RESUMEN

Hemorrhagic fever with renal syndrome (HFRS) is a zoonotic disease caused by the rodent-transmitted orthohantaviruses (HVs), with China possessing the most cases globally. The virus hosts in China are Apodemus agrarius and Rattus norvegicus, and the disease spread is strongly influenced by global climate dynamics. To assess and predict the spatiotemporal trends of HFRS from 2005 to 2098, we collected historical HFRS data in mainland China (2005-2020), historical and projected climate and population data (2005-2098), and spatial variables including biotic, environmental, topographical, and socioeconomic. Spatiotemporal predictions and mapping were conducted under 27 scenarios incorporating multiple integrated representative concentration pathway models and population scenarios. We identify the type of magistral HVs host species as the best spatial division, including four region categories. Seven extreme climate indices associated with temperature and precipitation have been pinpointed as key factors affecting the trends of HFRS. Our predictions indicate that annual HFRS cases will increase significantly in 62 of 356 cities in mainland China. Rattus regions are predicted to be the most active, surpassing Apodemus and Mixed regions. Eighty cities are identified as at severe risk level for HFRS, each with over 50 reported cases annually, including 22 new cities primarily located in East China and Rattus regions after 2020, while 6 others develop new risk. Our results suggest that the risk of HFRS will remain high through the end of this century, with Rattus norvegicus being the most active host, and that extreme climate indices are significant risk factors. Our findings can inform evidence-based policymaking regarding future risk of HFRS.


Asunto(s)
Fiebre Hemorrágica con Síndrome Renal , Ratas , Animales , Fiebre Hemorrágica con Síndrome Renal/epidemiología , Fiebre Hemorrágica con Síndrome Renal/etiología , Clima , Zoonosis , China/epidemiología , Murinae , Incidencia
2.
Eur Radiol ; 34(1): 579-587, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37528300

RESUMEN

OBJECTIVES: This study was aimed to quantitatively assess hyperperfusion using arterial spin labeling (ASL) to predict hemorrhagic transformation (HT) in acute ischemic stroke (AIS) patients. METHODS: This study enrolled 98 AIS patients with anterior circulation large vessel occlusion within 24 h of symptom onset. ASL was performed before mechanical endovascular therapy. On pre-treatment ASL maps, a region with relative cerebral blood flow (CBF) ≥ 1.4 was defined as an area of hyperperfusion. The maximum CBF (CBFmax) of hyperperfusion was calculated for each patient. A non-contrast CT scan was performed during the subacute phase for the evaluation of HT. Good clinical outcome was defined as a 90-day modified Rankin scale score of 0-2. RESULTS: The CBFmax of hyperperfusion (odds ratio, 1.023; 95% confidence interval [CI], 1.005-1.042; p = 0.012) was an independent risk factor for the status of HT. The CBFmax of hyperperfusion for HT showed an area under the curve of 0.735 (95% CI, 0.588-0.882) with optimal cutoff value, sensitivity, and specificity being 146.5 mL/100 g/min, 76.9%, and 69.6%, respectively. There was a statistically significant relationship between HT grades (from no HT to PH2) and CBFmax of hyperperfusion with a Spearman rank correlation of 0.446 (p = 0.001). In addition, low CBFmax of hyperperfusion were associated with good functional outcome (95% CI, 17.130-73.910; p = 0.002). CONCLUSIONS: High CBFmax of hyperperfusion was independently associated with subsequent HT and low CBFmax of hyperperfusion linked to good functional outcome. There was a positive correlation between HT grade and CBFmax. CLINICAL RELEVANCE STATEMENT: Arterial spin labeling is a noninvasive and contrast agent-independent technique, which is sensitive in detecting hyperperfusion. This study shows that the cerebral blood flow of hyperperfusion is associated with clinical prognosis, which will benefit more patients. KEY POINTS: • Quantitative assessment of hyperperfusion using pre-treatment arterial spin labeling to predict hemorrhagic transformation and prognosis in acute ischemic stroke patients. • The maximum cerebral blood flow of hyperperfusion was associated with hemorrhagic transformation and clinical prognosis and higher maximum cerebral blood flow of hyperperfusion was associated with higher grade hemorrhagic transformation. • The maximum cerebral blood flow of hyperperfusion can predict hemorrhagic transformation which enables timely intervention to prevent parenchymal hematoma.


Asunto(s)
Isquemia Encefálica , Procedimientos Endovasculares , Accidente Cerebrovascular Isquémico , Accidente Cerebrovascular , Humanos , Accidente Cerebrovascular/diagnóstico , Accidente Cerebrovascular Isquémico/complicaciones , Marcadores de Spin , Arterias , Circulación Cerebrovascular/fisiología , Isquemia Encefálica/complicaciones , Isquemia Encefálica/diagnóstico por imagen , Isquemia Encefálica/terapia
3.
Environ Sci Technol ; 58(14): 6226-6235, 2024 Apr 09.
Artículo en Inglés | MEDLINE | ID: mdl-38557021

RESUMEN

The updated climate models provide projections at a fine scale, allowing us to estimate health risks due to future warming after accounting for spatial heterogeneity. Here, we utilized an ensemble of high-resolution (25 km) climate simulations and nationwide mortality data from 306 Chinese cities to estimate death anomalies attributable to future warming. Historical estimation (1986-2014) reveals that about 15.5% [95% empirical confidence interval (eCI):13.1%, 17.6%] of deaths are attributable to nonoptimal temperature, of which heat and cold corresponded to attributable fractions of 4.1% (eCI:2.4%, 5.5%) and 11.4% (eCI:10.7%, 12.1%), respectively. Under three climate scenarios (SSP126, SSP245, and SSP585), the national average temperature was projected to increase by 1.45, 2.57, and 4.98 °C by the 2090s, respectively. The corresponding mortality fractions attributable to heat would be 6.5% (eCI:5.2%, 7.7%), 7.9% (eCI:6.3%, 9.4%), and 11.4% (eCI:9.2%, 13.3%). More than half of the attributable deaths due to future warming would occur in north China and cardiovascular mortality would increase more drastically than respiratory mortality. Our study shows that the increased heat-attributable mortality burden would outweigh the decreased cold-attributable burden even under a moderate climate change scenario across China. The results are helpful for national or local policymakers to better address the challenges of future warming.


Asunto(s)
Frío , Calor , Temperatura , Ciudades , China/epidemiología , Cambio Climático , Mortalidad
4.
Z Gastroenterol ; 2024 Apr 24.
Artículo en Inglés | MEDLINE | ID: mdl-38657616

RESUMEN

RATIONALE: The COVID-19 pandemic caused by the SARS-CoV-2 virus has led to health complications beyond respiratory symptoms, revealing multi-organ involvement, including potential gastrointestinal implications. PATIENT CONCERNS: We present a case of a 40-year-old female without any history of achalasia who developed symptoms of the condition following a confirmed SARS-CoV-2 infection. Unusually, multiple esophageal ulcers were identified, which are not typically associated with achalasia. DIAGNOSIS: Achalasia and esophageal ulcers were confirmed through a series of examinations, including barium swallow, CT scan, and upper endoscopy. Furthermore, immunohistochemical staining of esophageal biopsy specimens revealed the presence of the SARS-CoV-2 spike protein, suggesting direct viral involvement. INTERVENTIONS: The patient was treated with calcium channel blockers and proton pump inhibitors and later underwent a peroral endoscopic myotomy (POEM) procedure following the resolution of her COVID-19 infection. OUTCOME: After the POEM procedure, the patient made a good recovery. LESSONS: This case underscores the potential for SARS-CoV-2 to trigger gastrointestinal complications and emphasizes the need for ongoing patient management and further research into the long-term implications of COVID-19. Despite the single-case nature of this report, it contributes to the expanding understanding of the diverse and multi-systemic impact of COVID-19.

5.
Small ; 19(30): e2300688, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37029578

RESUMEN

The creation of anisotropic nanostructures with precise size control is desirable for new properties and functions, but it is challenging for ionic self-assembly (ISA) because of the non-directional electrostatic interactions. Herein, the formation of size-controllable tetragonal nanoprisms is reported via crystallization-directed ionic self-assembly (CDISA) through evaporating a micellar solution on solid substrates. First, ISA is designed with a crystalline polyethylene oxide (PEO) containing cationic polymer poly(2-(2-guanidinoethoxy)ethyl methacrylate)-b-poly(ethyleneoxide)-b-poly(2-(2-guanidinoethoxy)-ethylmethacrylate) (PGn -PEO230 -PGn ) and an anionic 5,10,15,20-Tetrakis(4-sulfonatophenyl) porphyrin (TPPS) to form micelles in aqueous solution. The PG segments binds excessive TPPS with amplenet chargeto form hydrophilic corona, while the PEO segments are unprecedentedly dehydrated and tightly packed into cores. Upon naturally drying the micellar solution on a silicon wafer, PEO crystallizationdirects the micelles to aggregate into square nanoplates, which are further connected to nanoprisms. Length and width of the nanoprisms can be facilely tuned by varying the initial concentration. In this hierarchical process, the aqueous self-assembly is prerequisite and the water evaporation rate is crucial for the formation of nanostructures, which provides multiple factors for morphology regulating. Such precise size-control strategy is highly expected to provide a new vision for the design of advanced materials with size controllable anisotropic nanostructures.

6.
Int Wound J ; 20(2): 448-457, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-35855676

RESUMEN

We performed a meta-analysis to evaluate the effect of low-frequency ultrasound as an added treatment for chronic wounds. A systematic literature search up to May 2022 was performed and 838 subjects with chronic wounds at the baseline of the studies; 412 of them were using the low-frequency ultrasound (225 low-frequency high-intensity contact ultrasound for diabetic foot wound ulcers, and 187 low-frequency low-intensity non-contact ultrasound for a venous leg wound ulcers), and 426 were using standard care (233 sharp debridements for diabetic foot wound ulcers and 193 sham treatments for venous leg wound ulcers). Odds ratio (OR), and mean difference (MD) with 95% confidence intervals (CIs) were calculated to assess the effect of low-frequency ultrasound as an added treatment for chronic wounds using the dichotomous, and contentious methods with a random or fixed-effect model. The low-frequency high-intensity contact ultrasound for diabetic foot wound ulcers had significantly lower non-healed diabetic foot wound ulcers at ≥3 months (OR, 0.37; 95% CI, 0.24-0.56, P < .001), a higher percentage of diabetic foot wound ulcers area reduction (MD, 17.18; 95% CI, 6.62-27.85, P = .002) compared with sharp debridement for diabetic foot wound ulcers. The low-frequency low-intensity non-contact ultrasound for a venous leg wound ulcers had a significantly lower non-healed venous leg wound ulcers at ≥3 months (OR, 0.31; 95% CI, 0.15-0.62, P = .001), and higher percentage venous leg wound ulcers area reduction (MD, 18.96; 95% CI, 2.36-35.57, P = .03) compared with sham treatments for a venous leg wound ulcers. The low-frequency ultrasound as an added treatment for diabetic foot wound ulcers and venous leg wound ulcers had significantly lower non-healed chronic wound ulcers at ≥3 months, a higher percentage of chronic wound ulcers area reduction compared with standard care. The analysis of outcomes should be with caution because of the low sample size of all the 17 studies in the meta-analysis and a low number of studies in certain comparisons.


Asunto(s)
Pie Diabético , Úlcera Varicosa , Humanos , Pie Diabético/diagnóstico por imagen , Pie Diabético/terapia , Úlcera , Ultrasonografía , Úlcera Varicosa/diagnóstico por imagen , Úlcera Varicosa/terapia , Cicatrización de Heridas
7.
Eur Radiol ; 32(10): 7185-7195, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35713662

RESUMEN

OBJECTIVES: The study aimed to investigate the diagnostic performance of intravoxel incoherent motion (IVIM) diffusion-weighted magnetic resonance imaging for prediction of microvascular invasion (MVI) in hepatocellular carcinoma (HCC) using convolutional neural networks (CNNs). METHODS: This retrospective study included 114 patients with pathologically confirmed HCC from December 2014 to August 2021. All patients underwent MRI examination including IVIM sequence with 9 b-values preoperatively. First, 9 b-value images were superimposed in the channel dimension, and a b-value volume with a shape of 32 × 32 × 9 dimension was obtained. Secondly, an image resampling method was performed for data augmentation to generate more samples for training. Finally, deep features to predict MVI in HCC were directly derived from a b-value volume based on the CNN. Moreover, a deep learning model based on parameter maps and a fusion model combined with deep features of IVIM, clinical characteristics, and IVIM parameters were also constructed. Receiver operating characteristic (ROC) curve analysis was performed to assess the diagnostic performance for MVI prediction in HCC. RESULTS: Deep features directly extracted from IVIM-DWI (0.810 (range 0.760, 0.829)) using CNN yielded better performance for prediction of MVI than those from IVIM parameter maps (0.590 (range 0.555, 0.643)). Furthermore, the performance of the fusion model combined with deep features of IVIM-DWI, clinical features (α-fetoprotein (AFP) level and tumor size), and apparent diffusion coefficient (ADC) (0.829 (range 0.776, 0.848)) was slightly improved. CONCLUSIONS: Deep learning with CNN based on IVIM-DWI can be conducive to preoperative prediction of MVI in patients with HCC. KEY POINTS: • Deep learning assessment of IVIM data for prediction of MVI in HCC can overcome the unstable and low performance of IVIM parameters. • Deep learning model based on IVIM performs better than parameter values, clinical features, and deep learning model based on parameter maps. • The fusion model combined with deep features of IVIM, clinical characteristics, and ADC yields better performance for prediction of MVI than the model only based on IVIM.


Asunto(s)
Carcinoma Hepatocelular , Neoplasias Hepáticas , Carcinoma Hepatocelular/patología , Imagen de Difusión por Resonancia Magnética/métodos , Humanos , Neoplasias Hepáticas/patología , Redes Neurales de la Computación , Estudios Retrospectivos
8.
Eur Radiol ; 32(4): 2188-2199, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-34842959

RESUMEN

OBJECTIVES: An accurate and rapid diagnosis is crucial for the appropriate treatment of pulmonary tuberculosis (TB). This study aims to develop an artificial intelligence (AI)-based fully automated CT image analysis system for detection, diagnosis, and burden quantification of pulmonary TB. METHODS: From December 2007 to September 2020, 892 chest CT scans from pathogen-confirmed TB patients were retrospectively included. A deep learning-based cascading framework was connected to create a processing pipeline. For training and validation of the model, 1921 lesions were manually labeled, classified according to six categories of critical imaging features, and visually scored regarding lesion involvement as the ground truth. A "TB score" was calculated based on a network-activation map to quantitively assess the disease burden. Independent testing datasets from two additional hospitals (dataset 2, n = 99; dataset 3, n = 86) and the NIH TB Portals (n = 171) were used to externally validate the performance of the AI model. RESULTS: CT scans of 526 participants (mean age, 48.5 ± 16.5 years; 206 women) were analyzed. The lung lesion detection subsystem yielded a mean average precision of the validation cohort of 0.68. The overall classification accuracy of six pulmonary critical imaging findings indicative of TB of the independent datasets was 81.08-91.05%. A moderate to strong correlation was demonstrated between the AI model-quantified TB score and the radiologist-estimated CT score. CONCLUSIONS: The proposed end-to-end AI system based on chest CT can achieve human-level diagnostic performance for early detection and optimal clinical management of patients with pulmonary TB. KEY POINTS: • Deep learning allows automatic detection, diagnosis, and evaluation of pulmonary tuberculosis. • Artificial intelligence helps clinicians to assess patients with tuberculosis. • Pulmonary tuberculosis disease activity and treatment management can be improved.


Asunto(s)
Inteligencia Artificial , Tuberculosis Pulmonar , Adulto , Anciano , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Persona de Mediana Edad , Estudios Retrospectivos , Tomografía Computarizada por Rayos X/métodos , Tuberculosis Pulmonar/diagnóstico por imagen
9.
Soft Matter ; 18(23): 4372-4377, 2022 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-35648108

RESUMEN

We report that γ-cyclodextrin (γ-CD) is able to catalyze the self-assembly process of the coordinating fluorescent molecule pyrenebutyrate with Zn2+. The direct interaction between pyrenebutyrate and Zn2+ would simply lead to amorphous precipitates, whereas addition of Zn2+ to the host-guest complex of pyrenebutyrate @ γ-CD would generate well-defined microflowers that have exactly the same composition as the amorphous pyrenebutyrate/Zn2+. The evidence of host-guest formation between 1-PBA and γ-CD and the absence of γ-CD in the final microflowers manifest that γ-CD acts as a catalyst in the self-assembly process. We envision that this dynamic host-guest chemistry would be very promising in creating catassemblies.


Asunto(s)
Ciclodextrinas , Catálisis , Colorantes , Ciclodextrinas/química
10.
J Cell Physiol ; 236(3): 1950-1966, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-32722851

RESUMEN

Osteolysis is a common medical condition characterized by excessive activity of osteoclasts and bone resorption, leading to severe poor quality of life. It is essential to identify the medications that can effectively suppress the excessive differentiation and function of osteoclasts to prevent and reduce the osteolytic conditions. It has been reported that Carnosol (Car), isolated from rosemary and salvia, has anti-inflammatory, antioxidative, and anticancer effects, but its activity on osteolysis has not been determined. In this study, we found that Car has a strong inhibitory effect on the receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast differentiation dose-dependently without any observable cytotoxicity. Moreover, Car can inhibit the RANKL-induced osteoclastogenesis and resorptive function via suppressing NFATc1, which is a result of affecting MAPK, NF-κB and Ca2+ signaling pathways. Moreover, the particle-induced osteolysis mouse model confirmed that Car could be effective for the treatment of bone loss in vivo. Taken together, by suppressing the formation and function of RANKL-induced osteoclast, Car, may be a therapeutic supplementary in the prevention or the treatment of osteolysis.


Asunto(s)
Abietanos/uso terapéutico , Osteogénesis , Osteólisis/inducido químicamente , Osteólisis/tratamiento farmacológico , Ligando RANK/farmacología , Titanio/efectos adversos , Abietanos/farmacología , Animales , Resorción Ósea/complicaciones , Resorción Ósea/genética , Resorción Ósea/patología , Señalización del Calcio/efectos de los fármacos , Femenino , Regulación de la Expresión Génica/efectos de los fármacos , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Masculino , Ratones Endogámicos C57BL , Modelos Biológicos , Inhibidor NF-kappaB alfa/metabolismo , FN-kappa B/metabolismo , Factores de Transcripción NFATC/metabolismo , Osteoclastos/efectos de los fármacos , Osteoclastos/metabolismo , Osteoclastos/patología , Osteogénesis/efectos de los fármacos , Osteogénesis/genética , Osteólisis/genética , Osteólisis/patología , Proteolisis/efectos de los fármacos , Cráneo/efectos de los fármacos , Cráneo/patología
11.
Langmuir ; 37(44): 13125-13131, 2021 11 09.
Artículo en Inglés | MEDLINE | ID: mdl-34714092

RESUMEN

Enzyme-instructed self-assembly is an increasingly attractive topic owing to its broad applications in biomaterials and biomedicine. In this work, we report an approach to construct enzyme-responsive aqueous surfactant two-phase (ASTP) systems serving as enzyme substrates by using a cationic surfactant (myristoylcholine chloride) and a series of anionic surfactants. Driven by the hydrophobic interaction and electrostatic attraction, self-assemblies of cationic-anionic surfactant mixtures result in biphasic systems containing condensed lamellar structures and coexisting dilute solutions, which turn into homogeneous aqueous phases in the presence of hydrolase (cholinesterase). The enzyme-sensitive ASTP systems reported in this work highlight potential applications in the active control of biomolecular enrichment/release and visual detection of cholinesterase.


Asunto(s)
Tensoactivos , Agua , Aniones , Cationes , Interacciones Hidrofóbicas e Hidrofílicas
12.
Langmuir ; 37(27): 8348-8355, 2021 07 13.
Artículo en Inglés | MEDLINE | ID: mdl-34210141

RESUMEN

Recent years have witnessed a growing interest in the design of enzyme-responsive molecular assemblies that hold appealing applications in the fields of disease-related sensing, imaging, and drug delivery. Cyclodextrins (CDs) are amylase-cleavable host molecules that can associate with surfactants, alkanes, alkyl amines, fatty alcohols, and aromatic compounds to form diverse supramolecular structures. In this work, we report a versatile supramolecular platform to construct enzyme-responsive nanosystems via host-guest interactions, in which complexation between CDs and surfactants eventually leads to the formation of a variety of nanostructures such as vesicles and microtubes. These supramolecular structures are capable of loading water-soluble molecules or functional nanoparticles, which can be actively released on-demand in the presence of α-amylase. This universal strategy to fabricate enzyme-responsive supramolecular systems was further demonstrated with a range of surfactants with anionic, cationic, and nonionic headgroups. Our results highlight a versatile platform for the exploration of biologically responsive self-assembly with potential applications as controlled-release systems and microrobots.


Asunto(s)
Ciclodextrinas , Nanopartículas , Nanoestructuras , Cationes
13.
Proc Natl Acad Sci U S A ; 115(27): 6946-6951, 2018 07 03.
Artículo en Inglés | MEDLINE | ID: mdl-29915092

RESUMEN

Water oxidation has long been a challenge in artificial photosynthetic devices that convert solar energy into fuels. Water-splitting dye-sensitized photoelectrochemical cells (WS-DSPECs) provide a modular approach for integrating light-harvesting molecules with water-oxidation catalysts on metal-oxide electrodes. Despite recent progress in improving the efficiency of these devices by introducing good molecular water-oxidation catalysts, WS-DSPECs have poor stability, owing to the oxidation of molecular components at very positive electrode potentials. Here we demonstrate that a solid-state dye-sensitized solar cell (ss-DSSC) can be used as a buried junction for stable photoelectrochemical water splitting. A thin protecting layer of TiO2 grown by atomic layer deposition (ALD) stabilizes the operation of the photoanode in aqueous solution, although as a solar cell there is a performance loss due to increased series resistance after the coating. With an electrodeposited iridium oxide layer, a photocurrent density of 1.43 mA cm-2 was observed in 0.1 M pH 6.7 phosphate solution at 1.23 V versus reversible hydrogen electrode, with good stability over 1 h. We measured an incident photon-to-current efficiency of 22% at 540 nm and a Faradaic efficiency of 43% for oxygen evolution. While the potential profile of the catalyst layer suggested otherwise, we confirmed the formation of a buried junction in the as-prepared photoelectrode. The buried junction design of ss-DSSs adds to our understanding of semiconductor-electrocatalyst junction behaviors in the presence of a poor semiconducting material.

14.
Angew Chem Int Ed Engl ; 59(25): 10081-10086, 2020 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-31633871

RESUMEN

Hydration water greatly impacts the color of inorganic crystals, but it is still unknown whether hydration water can be utilized to systematically manipulate the emission color of organic luminescent groups. Now, metal ions with different hydration ability allow fine-tuning the emission color of a fluorescent group displaying aggregation induced emission (AIE). Because the hydration water can be removed easily by gentle heating or mechanical grinding and re-gained by solvent fuming, rewritable materials can be fabricated both in the hot-writing and cold-writing modes. This hydration-facilitated strategy will open up a new vista in fine-tuning the emission color of AIE molecules based on one synthesis and in the design of smart luminescent devices.

15.
Angew Chem Int Ed Engl ; 59(48): 21510-21514, 2020 11 23.
Artículo en Inglés | MEDLINE | ID: mdl-32779357

RESUMEN

The fusion and fission behaviors of exosomes are essential for the cell-to-cell communication. Developing exosome-mimetic vesicles with such behaviors is of vital importance, but still remains a big challenge. Presented herein is an artificial supramolecular vesicle that exhibits redox-modulated reversible fusion-fission functions. These vesicles tend to fuse together and form large-sized vesicles upon oxidation, undergo a fission process and then return to small-sized vesicles through reduction. Noteworthy, the aggregation-induced emission (AIE) characteristics of the supramolecular building blocks enable the molecular configuration during vesicular transformation to be monitored by fluorescence technology. Moreover, the presented vesicles are excellent nanocarrier candidates to transfer siRNA into cancer cells.


Asunto(s)
Exosomas/metabolismo , Compuestos de Hierro/metabolismo , Neoplasias del Cuello Uterino/metabolismo , Antineoplásicos/química , Antineoplásicos/metabolismo , Antineoplásicos/farmacología , Comunicación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Portadores de Fármacos/química , Portadores de Fármacos/metabolismo , Portadores de Fármacos/farmacología , Exosomas/química , Femenino , Células HeLa , Humanos , Compuestos de Hierro/química , Compuestos de Hierro/farmacología , Sustancias Macromoleculares/química , Sustancias Macromoleculares/metabolismo , Sustancias Macromoleculares/farmacología , Estructura Molecular , Oxidación-Reducción , Tamaño de la Partícula , ARN Interferente Pequeño/química , ARN Interferente Pequeño/metabolismo , ARN Interferente Pequeño/farmacología , Propiedades de Superficie , Neoplasias del Cuello Uterino/tratamiento farmacológico , Neoplasias del Cuello Uterino/patología
16.
Chemistry ; 24(52): 13734-13739, 2018 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-30256477

RESUMEN

Host-guest interactions are widely employed in constructing responsive materials, although less is known to manipulate the chiral property of materials using such host-guest dynamics. With the supramolecular self-assembly based on ß-cyclodextrin (ß-CD) and alkyl amines (CH3(CH2)n-1NH2), we report that faster host-guest dynamics induces a dipole located above the cavity of ß-CD, whereas slower dynamics create in-cavity dipole. These two scenarios correspond to negative and positive chiral signals, respectively. Considering that a larger fraction of amines facilitates faster exchange between the threaded and unthreaded amines, the chiral signal for the right-handed helical ribbons can be manipulated simply by alternatively increasing the fraction of amines and ß-CD. Excitingly, enzyme responsive supramolecular chirality is obtained as a result of shifting the molar ratio by enzyme triggered hydrolysis of ß-CD. We expect that this strategy may open up an area of rationally designed chiral supramolecular materials based on host-guest chemistry.

17.
Langmuir ; 34(20): 5935-5942, 2018 05 22.
Artículo en Inglés | MEDLINE | ID: mdl-29708341

RESUMEN

Allosteric regulation is extensively employed by nature to achieve functional control of protein or deoxyribonucleic acid through triggered conformational change at a remote site. We report that a similar strategy can be utilized in artificial self-assembly to control the self-assembled structure and its function. We show that on binding of metal ions to the headgroup of an amphiphile TTC4L, the conformational change may lead to change of the dipole orientation of the energy donor at the chain end. This on the one hand leads to a drastically different self-assembled structure; on the other hand, it enables light harvesting between the donor-acceptor. Because the Forster resonance fluorescence transfer efficiency is gated by metal ions, controlling the feeding of metal ions allows switching on and off of light harvesting. We expect that using allosteric self-assembly, we will be able to create abundant structures with distinct function from limited molecules, which show prominent potential for the postorganic modification of the structure and function of self-assembled materials.

18.
Langmuir ; 33(44): 12719-12728, 2017 11 07.
Artículo en Inglés | MEDLINE | ID: mdl-29028356

RESUMEN

The aggregation behavior of cationic ammonium gemini surfactant hexamethylene-1,6-bis(dodecyldimethylammonium bromide) (12-6-12) with chelating molecule ethylenediaminetetraacetic acid (EDTA) and the effects of calcium bromide (CaBr2) on the structure and morphology of the aggregates in the mixture have been investigated by surface tension, isothermal titration microcalorimetry, electrical conductivity, ζ potential, dynamic light scattering, cryogenic transmission electron microscopy, freeze-fracture transmission electron microscopy, and 1H NMR techniques. It was found that the electrostatic attraction between the carboxyl groups of EDTA and the headgroups of 12-6-12 leads to the formation of oligomeric-like surfactant EDTA(12-6-12)2 at an EDTA/12-6-12 molar ratio of 0.50. The critical aggregation concentration of the EDTA(12-6-12)2 complexes is much lower than that of 12-6-12, and the complexes form loose, large network-like premicellar aggregates and then transfer into small micelles with an increase in concentration. Moreover, the addition of CaBr2 induces the transition from the loose aggregates and micelles to vesicles owing to the coordination interaction between the calcium ion and EDTA and the electrostatic interaction between EDTA and 12-6-12. The work reveals that as a bridging molecule between the calcium ion and the gemini surfactant, the chelating molecule greatly promotes the assembly of the gemini surfactant and strengthens the molecular packing in the presence of calcium ions.

19.
Molecules ; 22(4)2017 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-28368328

RESUMEN

A facile, green, and efficient method for the direct oxidative amination of benzoxazoles using heterocyclic ionic liquid as catalyst has been developed. The reaction proceeded smoothly at room temperature and gave the desirable 2-aminobenzoxazoles with good to excellent yields (up to 97%). The catalyst 1-butylpyridinium iodide can be easily recycled and reused with similar efficacies for at least four cycles.


Asunto(s)
Benzoxazoles/síntesis química , Tecnología Química Verde , Líquidos Iónicos/química , Aminación , Benzoxazoles/química , Catálisis , Oxidación-Reducción
20.
Langmuir ; 32(45): 11973-11979, 2016 11 15.
Artículo en Inglés | MEDLINE | ID: mdl-27762561

RESUMEN

The ability to modulate amphiphilic aggregation reversibly with external stimuli, especially using light as a trigger, is of great importance. This has greatly contributed to the development of applications using self-assembly. However, most previously described systems are based on a specific molecular design and have shown difficultly in their application to light-inert aggregation. Here, we developed a general and effective approach to control the morphology of amphiphilic aggregates by light, which is suitable for different assemblies such as micelles, vesicles, and helixes. Our strategy is to construct a photoresponsive factor into light-inert self-assemblies. On the basis of the different capabilities to form host-guest inclusions between photoresponsive azobenzene sodium and light-inert molecules with cyclodextrin, the transformation of the corresponding amphiphilic aggregation can be controlled easily and reversibly by light stimuli. Not only the nanostructure of the aggregates but also the phase behavior, such as gel formation, can be modulated upon light irradiation using this method.

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