Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 110
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Proc Natl Acad Sci U S A ; 121(4): e2314396121, 2024 Jan 23.
Artículo en Inglés | MEDLINE | ID: mdl-38236736

RESUMEN

In our quest to leverage the capabilities of the emerging single-atom catalysts (SACs) for wastewater purification, we confronted fundamental challenges related to electron scarcity and instability. Through meticulous theoretical calculations, we identified optimal placements for nitrogen vacancies (Nv) and iron (Fe) single-atom sites, uncovering a dual-site approach that significantly amplified visible-light absorption and charge transfer dynamics. Informed by these computational insights, we cleverly integrated Nv into the catalyst design to boost electron density around iron atoms, yielding a potent and flexible photoactivator for benign peracetic acid. This exceptional catalyst exhibited remarkable stability and effectively degraded various organic contaminants over 20 cycles with self-cleaning properties. Specifically, the Nv sites captured electrons, enabling their swift transfer to adjacent Fe sites under visible light irradiation. This mechanism accelerated the reduction of the formed "peracetic acid-catalyst" intermediate. Theoretical calculations were used to elucidate the synergistic interplay of dual mechanisms, illuminating increased adsorption and activation of reactive molecules. Furthermore, electron reduction pathways on the conduction band were elaborately explored, unveiling the production of reactive species that enhanced photocatalytic processes. A six-flux model and associated parameters were also applied to precisely optimize the photocatalytic process, providing invaluable insights for future photocatalyst design. Overall, this study offers a molecule-level insight into the rational design of robust SACs in a photo-Fenton-like system, with promising implications for wastewater treatment and other high-value applications.

2.
Environ Sci Technol ; 58(27): 12155-12166, 2024 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-38934735

RESUMEN

The rising in situ chemical oxidation (ISCO) technologies based on polymerization reactions have advanced the removal of emerging contaminants in the aquatic environment. However, despite their promise, uncertainties persist regarding their effectiveness in eliminating structurally complex contaminants, such as sulfonamide antibiotics (SAs). This study elucidated that oligomerization, rather than mineralization, predominantly governs the removal of SAs in the carbon materials/periodate system. The amine groups in SAs played a crucial role in forming organic radicals and subsequent coupling reactions due to their high f- index and low bond orders. Moreover, the study highlighted the robust adhesion of oligomers to the catalyst surface, facilitated by enhanced van der Waals forces and hydrophobic interactions. Importantly, plant and animal toxicity assessments confirmed the nontoxic nature of oligomers deposited on the carbon material surface, affirming the efficacy of carbon material-based ISCO in treating contaminated surface water and groundwater. Additionally, a novel classification approach, Δlog k, was proposed to differentiate SAs based on their kinetic control steps, providing deeper insights into the quantitative structure-activity relationship (QSAR) and facilitating the selection of optimal descriptors during the oligomerization processes. Overall, these insights significantly enhance our understanding of SAs removal via oligomerization and demonstrate the superiority of C-ISCO based on polymerization in water decontamination.


Asunto(s)
Antibacterianos , Carbono , Sulfonamidas , Antibacterianos/química , Carbono/química , Sulfonamidas/química , Contaminantes Químicos del Agua/química , Purificación del Agua
3.
Biotechnol Appl Biochem ; 71(4): 701-711, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38409880

RESUMEN

Sepsis-associated encephalopathy (SAE) is characterized by high incidence and mortality rates, with limited treatment options available. The underlying mechanisms and pathogenesis of SAE remain unclear. Annexin A1 (ANXA1), a membrane-associated protein, is involved in various in vivo pathophysiological processes. This study aimed to explore the neuroprotective effects and mechanisms of a novel bioactive ANXA1 tripeptide (ANXA1sp) in SAE. Forty Sprague-Dawley rats were randomly divided into four groups (n = 10 each): control, SAE (intraperitoneal injection of lipopolysaccharide), vehicle (SAE + normal saline), and ANXA1sp (SAE + ANXA1sp) groups. Changes in serum inflammatory factors (interleukin-6 [IL-6], tumor necrosis factor-α [TNF-α]), hippocampal reactive oxygen species (ROS), mitochondrial membrane potential (MMP), and adenosine triphosphate (ATP) levels were measured. The Morris water maze and Y maze tests were used to assess learning and memory capabilities in the rats. Further, changes in peroxisome proliferator-activated receptor-gamma (PPAR-γ) and apoptosis-related protein expression were detected using western blot. The IL-6, TNF-α, and ROS levels were significantly increased in the SAE group compared with the levels in the control group. Intraperitoneal administration of ANXA1sp led to a significant decrease in the IL-6, TNF-α, and ROS levels (p < 0.05). Compared with the SAE group, the ANXA1sp group exhibited reduced escape latency on day 5, a significant increase in the number of platform crossings and the percent spontaneous alternation, and significantly higher hippocampal MMP and ATP levels (p < 0.05). Meanwhile, the expression level of PPAR-γ protein in the ANXA1sp group was significantly increased compared with that in the other groups (p < 0.05). The expressions of apoptosis-related proteins (nuclear factor-kappa B [NF-κB], Bax, and Caspase-3) in the SAE and vehicle groups were significantly increased, with a noticeable decrease in Bcl-2 expression, compared with that noted in the control group. Moreover, the expressions of NF-κB, Bax, and Caspase-3 were significantly decreased in the ANXA1sp group, and the expression of Bcl-2 was markedly increased (p < 0.05). ANXA1sp can effectively reverse cognitive impairment in rats with SAE. The neuroprotective effect of ANXA1sp may be attributed to the activation of the PPAR-γ pathway, resulting in reduced neuroinflammatory response and inhibition of apoptosis.


Asunto(s)
Anexina A1 , Fármacos Neuroprotectores , Ratas Sprague-Dawley , Encefalopatía Asociada a la Sepsis , Animales , Anexina A1/metabolismo , Anexina A1/farmacología , Ratas , Fármacos Neuroprotectores/farmacología , Masculino , Encefalopatía Asociada a la Sepsis/tratamiento farmacológico , Encefalopatía Asociada a la Sepsis/metabolismo , Encefalopatía Asociada a la Sepsis/patología , Especies Reactivas de Oxígeno/metabolismo , Apoptosis/efectos de los fármacos , PPAR gamma/metabolismo , Potencial de la Membrana Mitocondrial/efectos de los fármacos
4.
Mikrochim Acta ; 190(8): 325, 2023 07 26.
Artículo en Inglés | MEDLINE | ID: mdl-37493765

RESUMEN

A cost-effective approach has been developed to synthesize Cu nanoparticles encapsulated into B and N double-doped carbon nanotubes (Cu@BCNNTs) by one-step pyrolysis. According to the specific binding of Cu-Cl and Cu-glutathione (GSH), we employed Cu@BCNNTs to build an electrochemical sensing platform to detect GSH. The unique space-confined structure can prevent Cu nanoparticles from agglomeration. In addition, B and N co-doped porous hollow tubes can improve the electrochemical conductivity, expand the number of active sites, enhance surface adsorption, and shorten the transport path. These favorable characteristics of Cu@BCNNTs make them have excellent electrocatalytic properties. These results display that the prepared sensor can detect GSH from 0.5 to 120 µM with a detection limit of 0.024 µM. The obtained sensors can be successfully applied in the human serum with recovery of GSH ranging from 100.2 to 103.9%. This work provides a new vision to synthesize nanoparticles confined in a hollow tube for the applications in biosensing and medical diagnostics.


Asunto(s)
Técnicas Biosensibles , Nanopartículas , Nanotubos de Carbono , Humanos , Nanotubos de Carbono/química , Porosidad , Técnicas Biosensibles/métodos , Técnicas Electroquímicas/métodos , Electrodos , Nanopartículas/química , Glutatión , Nanotecnología
5.
Zhongguo Dang Dai Er Ke Za Zhi ; 23(1): 12-17, 2021 Jan.
Artículo en Zh | MEDLINE | ID: mdl-33476531

RESUMEN

Drowning is a leading cause of accidental injury in children and has a great impact on family and society. The prevention and treatment of drowning is of great importance for reducing mortality rate. This consensus reviews the literature on the epidemiology, rescue, resuscitation, and acute clinical management and prevention of drowning. The panel determines the score of available evidence according to the criteria of Oxford Centre for Evidence-Based Medicine and then makes recommendations on evidence based on such criteria, so as to provide a basis for further reducing the mortality and disability rates caused by drowning.


Asunto(s)
Ahogamiento , Niño , Consenso , Ahogamiento/epidemiología , Ahogamiento/prevención & control , Humanos , Resucitación
6.
Anal Chem ; 92(23): 15297-15305, 2020 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-33185440

RESUMEN

Oxidative stress is a state of stress injury, which leads to the pathogenesis of most neurodegenerative diseases. Moreover, this is also one of the main reasons for the loss of dopaminergic neurons and the abnormal content of dopamine (DA). In the past decades, a number of studies have found that acetaminophen (AP) is metabolized and distributed in the brain when it is used as a neuroprotective compound. In this context, we proposed an electrochemical sensor based on 9-(4-(10-phenylanthracen-9-yl)phenyl)-9H-carbazole with the goal of diagnosing these two drugs in the body. Carbazole groups can easily be formed into large π-conjugated systems by electropolymerization. The introduction of anthracene exactly combined the carbazole group to establish an efficient electron donor-acceptor pattern, which enhanced π-π interaction with the electrode surface and charge transporting ability. The diagnostic platform showed good sensing activity toward the oxidation of DA and AP. The detection range for DA and AP is from 0.2 to 300 µM and from 0.2 to 400 µM, respectively. The simultaneous detection range is from 0.5 to 250 µM, which is wider than most reports. After a series of electrochemical assessments were determined, the sensor was finally developed to the analysis of pharmaceutical and human serum, displaying a meaningful potential in clinical evaluation.


Asunto(s)
Teoría Funcional de la Densidad , Electroquímica/métodos , Acetaminofén/análisis , Acetaminofén/sangre , Acetaminofén/química , Dopamina/análisis , Dopamina/sangre , Dopamina/química , Electroquímica/instrumentación , Electrodos , Humanos , Modelos Moleculares , Conformación Molecular , Oxidación-Reducción , Polimerizacion
7.
Mikrochim Acta ; 187(3): 163, 2020 02 12.
Artículo en Inglés | MEDLINE | ID: mdl-32052190

RESUMEN

An electrochemical aptasensor for thrombin is introduced that makes use of a nanohybrid composed of silver nanoparticles and graphite-like carbon nitride (Ag-g-C3N4). The material has a large surface and good biocompatibility. AgNPs are modified directly on the surface of g-C3N4 via chemical reduction. A glass carbon electrode (GCE) modified with Ag-g-C3N4 can immobilize a large number of amino-terminated thrombin binding aptamers (NH2-TBA) through strong Ag-N bonds. The electrochemical impedance signal of the aptasensor increases in the presence of thrombin. Under the optimal conditions and by using [Fe(CN)6]3-/4- as an electrochemical probe, the aptasensor shows a wide linear range of 100 fM - 20 nM with a lower detection limit of 38 fM. The method was applied to the determination of thrombin in spiked human plasma and the recoveries fluctuated from 97.2% to 103%. Graphical abstractSchematic representation of an electrochemical aptasensor using graphite-like carbon nitride (C3N4) modified with silver nanoparticles as electrode substrate for thrombin (TB) detection.


Asunto(s)
Técnicas Electroquímicas/métodos , Nanopartículas del Metal/química , Plata/química , Trombina/química , Humanos
8.
Anal Chem ; 91(18): 11938-11945, 2019 09 17.
Artículo en Inglés | MEDLINE | ID: mdl-31429273

RESUMEN

Research about DNA composition has been concentrated on DNA damage in the past few decades. However, it still remains a great challenge to construct a rapid, facile, and accurate approach for simultaneously monitoring four DNA bases, guanine (G), adenine (A), thymine (T), and cytosine (C). Herein, a novel electrochemical sensor based on phenanthroimidazole derivative, 2-(4-bromophenyl)-1-phenyl-1H-phenanthro[9,10-d]-imidazole (PPI), is successfully fabricated by a simple electrochemical method. The bromophenyl group in PI could expand their aromatic plane, induce the π-conjugated extension, and enhance the charge transfer and π-π interaction. The phenyl group at N1 position could regulate the intermolecular interaction, which could promote the possibility of intermolecular connection. The PPI polymer (poly(PPI)) with π-electron enriched conjugation architecture has been applied in simultaneous determination of G, A, T, and C in neutral solution by square wave voltammetry (SWV) method with well-separated peak potentials at 0.714, 1.004, 1.177, and 1.353 V, respectively. The sensor functionalized with poly(PPI) exhibits wide linear response for G, A, T, and C in the concentration ranges of 3-300, 1-300, 30-800, and 20-750 µM, respectively. With favorable selectivity, stability, and reproducibility, the sensor is successfully utilized to monitor four DNA bases in real samples, displaying a promising prospect for electrochemical sensing devices.


Asunto(s)
Adenina/análisis , Citosina/análisis , Guanina/análisis , Fenantrolinas/química , Timina/análisis , Técnicas Biosensibles , Catálisis , Técnicas Electroquímicas
9.
Anal Chem ; 91(16): 10589-10595, 2019 08 20.
Artículo en Inglés | MEDLINE | ID: mdl-31333020

RESUMEN

Here, we report ZIF-8-reduced graphene oxide (ZIF-8-rGO)-supported bimetallic AuPt nanoparticles (AuPtNPs) as a novel peroxidase mimic for high-sensitivity detection of H2O2 in neutral solution. ZIF-8-graphene oxide (ZIF-8-GO) is first synthesized via a simple wet-chemistry process and subsequently immobilized with AuPtNPs via a reduction method. The resultant AuPt/ZIF-8-rGO shows enhanced peroxidase-like catalytic activity and it is applied for the electrochemical detection of H2O2 in a wide concentration range, from 100 nM to 18 mM, with a very low detection limit of 19 nM (S/N = 3). This good electroanalytical performance of AuPt/ZIF-8-rGO is owing to the ultrasmall size and high dispersion of the AuPtNPs, the strong metal-support interaction between the AuPtNPs and ZIF-8-rGO bisupport, and the sandwich-like structure comprising porous ZIF-8 and loosely packed rGO nanosheets. The AuPt/ZIF-8-rGO is employed for the practical detection of H2O2 in human serum samples with desirable properties. Therefore, the novel AuPt/ZIF-8-rGO is a promising nanozyme for various biotechnological and environmental applications.

10.
Ecotoxicol Environ Saf ; 174: 129-136, 2019 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-30825735

RESUMEN

Zeolite has traditionally been used to remediate wastewater and soil. The present study shows a new method for natural zeolite (NZ) modification with wood vinegar (WV). The optimal conditions for NZ modification with WV were determined, and the adsorption capacities towards lead (Pb), cadmium (Cd) and arsenic (As), antimicrobial activities against Escherichia coli, heavy metal(loid) fraction and characterizations of selected modified zeolites (MZs) were also investigated. The results indicate that 50-fold dilution of WV, 5 g of NZ dosage, 105 °C of drying temperature, 4 h and 95 °C of water bath are preferred for NZ modification with WV. The WV+NaOH-MZ exhibited the best performance in heavy metal removal and the most powerful antimicrobial activity among all the zeolites. The sequence of WV+NaOH-MZ for the maximum single metal(loid) adsorption capacities was Pb (48.67 mg/g) >Cd (23.67 mg/g) > As (0.024 mg/g). The WV+NaOH and WV modifications also can increase the stabilities of heavy metals in the MZs. The residual fractions of single Pb and Cd in WV+NaOH-MZ and WV-MZ were 50%, 55%, 34% and 30%, respectively. The pore size of WV+NaOH-MZ (11.73 nm) was bigger than that of NZ or WV-MZ. Additionally, the proportion of clinoptilolite in WV+NaOH-MZ was also higher than other zeolites. The surfaces of WV+alkali-MZs were rougher than that of NZ. Considering the low cost and environmental risk of WV, this work provides some useful information for management of agricultural and industrial residues, environment and food safety.


Asunto(s)
Ácido Acético/química , Arsénico/análisis , Escherichia coli/metabolismo , Metales Pesados/análisis , Metanol/química , Contaminantes Químicos del Agua/análisis , Zeolitas/química , Adsorción , Arsénico/metabolismo , Cadmio/análisis , Cadmio/metabolismo , Desinfección/métodos , Plomo/análisis , Plomo/metabolismo , Metales Pesados/metabolismo , Suelo/química , Aguas Residuales/química , Contaminantes Químicos del Agua/metabolismo , Zeolitas/análisis
11.
Mikrochim Acta ; 186(4): 240, 2019 03 13.
Artículo en Inglés | MEDLINE | ID: mdl-30868250

RESUMEN

An antifouling electrochemical aptasensor for ATP is described that has a zwitterionic self-assembled sensing interface on a glassy carbon electrode modified with a reduced graphene oxide carbon nanofiber (GO-CNF). The GO-CNF was first modified by self-polymerization of dopamine which provided a platform for simultaneously self-assembly of the ATP aptamer and cysteine. By using hexacyanoferrate as the electrochemical probe, in the presence of ATP, the aptamer strands fold around ATP molecules, thus leading to the variation of the electrochemical signal. The aptasensor has a linear response in the 0.1 pM to 5 nM ATP concentration range, and a 13 fM lower detection limit. The electrode is strongly resistant to nonspecific adsorption and biofouling. This enabled the detection of ATP even in spiked human plasma. Graphical abstract An antifouling electrochemical aptasensor employing reduced graphene oxide carbon nanofiber as conductive substrate and zwitterionic cysteine as antifouling material for adenosine triphosphate detection.


Asunto(s)
Adenosina Trifosfato/sangre , Aptámeros de Nucleótidos/química , Técnicas Biosensibles/métodos , Grafito/química , Nanofibras/química , Cisteína/química , ADN/química , Espectroscopía Dieléctrica/instrumentación , Espectroscopía Dieléctrica/métodos , Electrodos , Humanos , Límite de Detección , Reproducibilidad de los Resultados
12.
J Clin Microbiol ; 55(5): 1488-1495, 2017 05.
Artículo en Inglés | MEDLINE | ID: mdl-28249997

RESUMEN

Rapid and accurate detection and identification of microbial pathogens causing urinary tract infections allow prompt and specific treatment. We optimized specimen processing to maximize the limit of detection (LOD) by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and evaluated the capacity of combination of MALDI-TOF MS and urine analysis (UA) for direct detection and identification of bacterial pathogens from urine samples. The optimal volumes of processed urine, formic acid/acetonitrile, and supernatant spotted onto the target plate were 15 ml, 3 µl, and 3 µl, respectively, yielding a LOD of 1.0 × 105 CFU/ml. Among a total of 1,167 urine specimens collected from three hospital centers, 612 (52.4%) and 351 (30.1%) were, respectively, positive by UA and urine culture. Compared with a reference method comprised of urine culture and 16S rRNA gene sequencing, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of MALDI-TOF MS alone and MALDI-TOF MS coupled with UA were 86.6% versus 93.4% (χ2 = 8.93; P < 0.01), 91.5% versus 96.3% (χ2 = 7.06; P < 0.01), 81.5% versus 96.4% (χ2 = 37.32; P < 0.01), and 94.1% versus 93.1% (χ2 = 0.40; P > 0.05), respectively. No significant performance differences were revealed among the three sites, while specificity and NPV of MALDI-TOF MS for males were significantly higher than those for females (specificity, 94.3% versus 77.3%, χ2 = 44.90, P < 0.01; NPV, 95.5% versus 86.1%, χ2 = 18.85, P < 0.01). Our results indicated that the optimization of specimen processing significantly enhanced analytical sensitivity and that the combination of UA and MALDI-TOF MS provided an accurate and rapid detection and identification of bacterial pathogens directly from urine.


Asunto(s)
Bacterias/clasificación , Bacterias/aislamiento & purificación , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos , Infecciones Urinarias/diagnóstico , Orina/microbiología , Algoritmos , Bacterias/genética , Técnicas Bacteriológicas/métodos , Enterococcus faecalis/genética , Enterococcus faecalis/aislamiento & purificación , Escherichia coli/genética , Escherichia coli/aislamiento & purificación , Femenino , Humanos , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/aislamiento & purificación , Límite de Detección , Masculino , ARN Ribosómico 16S/genética , Sensibilidad y Especificidad , Urinálisis/métodos , Infecciones Urinarias/microbiología
13.
Mycopathologia ; 182(5-6): 555-560, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-27928649

RESUMEN

The value of (1 â†’ 3)-beta-D-glucans (BG) and galactomannan (GM) assays on diagnostic invasive fungal infections (IFIs) has been observed in adult ICU and in children with hematological malignancies. Only scant data evaluated non-hematological in pediatric intensive care unit (PICU). Here, we retrospectively analyzed the role of bacterial infection to the reactivity of BG and GM assays in PICU. The results showed that the overall prevalence of bacteremia was 13.8% (65/470). The most common underlying disease was pneumonia (81.8%), followed by congenital heart disease (43.2%). The median levels of GM and range for each group [A: without bacterial infection nor IFIs (n = 151); B, patients with bacterial infection (n = 36); C, patients with bacterial infection and IFIs (n = 8)] were, respectively: 0.14 (0.01-1.34), 0.21 (0.06-1.34), 0.14 (0.02-0.99). No significant difference was found among three groups (P = 0.66). The median levels of BG and range for each group (A, B, C) were, respectively: 50.00 pg/mL (16.20-548.20 pg/mL), 50.00 pg/mL (16.10-597.60 pg/mL), 268.7 pg/mL (50.9-4224.00 pg/mL). Patients with bacteremia and IFIs showed significantly higher BG levels than these who with or without bacteremia (P = 0.003), but there was no significant difference between control subjects and patients with bacteremia group. We also observed the GM and BG levels in Gram-negative and Gram-positive groups. No significant difference was found between two groups. In conclusions, the results showed that bacteremia was unlikely cause of false-positive results of the BG and GM assays in PICU.


Asunto(s)
Bacteriemia/complicaciones , Infecciones Fúngicas Invasoras/diagnóstico , Mananos/sangre , beta-Glucanos/sangre , Niño , Preescolar , Femenino , Galactosa/análogos & derivados , Humanos , Lactante , Unidades de Cuidado Intensivo Pediátrico , Masculino , Estudios Retrospectivos
14.
Mycopathologia ; 182(3-4): 331-338, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-27664106

RESUMEN

The relationship among (1,3)-ß-D-glucans (BG), galactomannan (GM), and the risk of developing invasive fungal infections (IFI) has been observed in adult ICU and in children with hematological malignancies. Only scant data evaluated the value of BG/GM assays for diagnosis of IFI in patients with nonhematological diseases in pediatric intensive care unit (PICU). In this study, we assessed the diagnostic value of these markers for IFI in PICU. The records of 230 patients were retrospectively evaluated. Out of 117 patients (7 proven, 23 probable, and 87 cases without evidence of IFI) performed GM and BG assays. The results showed many factors were associated with false-positive test results. Patients who aged over 3 years had higher levels of GM and BG than younger infants. The levels of BG were higher in subjects with dairy, human blood products, antibiotics, and corticosteroids therapy than in cases without these treatments. Unlike BG assay, GM assay was less susceptible to above-mentioned factors expect blood products. The levels of BG and GM in IFI cases were dramatically higher than in controls. The diagnostic performance of these assays showed that GM assay had better results when compared with BG assay. On the whole, negative predictive value in both GM and BG assays was dramatically higher than other diagnostic parameters. In conclusion, BG assay was highly susceptible to many factors, and GM assay could be useful for diagnosis of IFI for its high sensitivity, but the over benefit of this assay limited in its inadequate specificity. The comparative advantage of BG and BG assays lied in excluding IFI in non-hematological PICU patients.


Asunto(s)
Antígenos Fúngicos/sangre , Pruebas Diagnósticas de Rutina/métodos , Infecciones Fúngicas Invasoras/diagnóstico , Mananos/sangre , beta-Glucanos/sangre , Femenino , Galactosa/análogos & derivados , Humanos , Lactante , Unidades de Cuidado Intensivo Pediátrico , Masculino , Valor Predictivo de las Pruebas , Proteoglicanos , Estudios Retrospectivos , Sensibilidad y Especificidad
15.
Angew Chem Int Ed Engl ; 56(50): 16082-16085, 2017 12 11.
Artículo en Inglés | MEDLINE | ID: mdl-29119659

RESUMEN

We report a facile approach to prepare an artificial enzyme system for tandem catalysis. NiPd hollow nanoparticles and glucose oxidase (GOx) were simultaneously immobilized on the zeolitic imidazolate framework 8 (ZIF-8) via a co-precipitation method. The as-prepared GOx@ZIF-8(NiPd) nanoflower not only exhibited the peroxidase-like activity of NiPd hollow nanoparticles but also maintained the enzymatic activity of GOx. A colorimetric sensor for rapid detection of glucose was realized through the GOx@ZIF-8(NiPd) based multi-enzyme system. Moreover, the GOx@ZIF-8(NiPd) modified electrode showed good bioactivity of GOx and high electrocatalytic activity for the oxygen reduction reaction (ORR), which could also be used for electrochemical detection of glucose.


Asunto(s)
Biocatálisis , Enzimas Inmovilizadas/metabolismo , Glucosa Oxidasa/metabolismo , Nanopartículas/química , Níquel/metabolismo , Paladio/metabolismo , Zeolitas/metabolismo , Técnicas Biosensibles/métodos , Colorimetría , Electrodos , Enzimas Inmovilizadas/química , Glucosa/análisis , Glucosa Oxidasa/química , Níquel/química , Oxígeno/metabolismo , Paladio/química , Zeolitas/química
16.
Cell Physiol Biochem ; 38(5): 1803-14, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27160160

RESUMEN

BACKGROUND/AIMS: In recent years, a traditional Chinese medicine named Huang Qi Huai (HQH) has been frequently used in China for solid tumor therapy. However, the role of HQH on leukemia cells and its underlying mechanisms have not been elucidated. In this study, we investigated the effect of HQH on the proliferation and apoptosis of acute lymphoblastic leukemia (ALL) cell lines. METHODS: Sup-B15 and Nalm-6 cells were treated with gradient doses of HQH for 24, 48 or 72 h. Cell viability was measured using a CCK8 assay and cell cycle distribution and apoptosis levels were analyzed using flow cytometry. Western blotting was used to assess the levels of proteins associated with the apoptotic pathway. RESULTS: The results revealed that cell survival decreased significantly with increasing concentrations of HQH. HQH induced G2 cell-cycle arrest and cell apoptosis in a dose-dependent manner. HQH inhibited phosphorylated-Akt, phosphorylated- FoxO1 and Bcl2 expression and upregulated Bim, cleaved-caspase-3 and Bax expression in a dose-dependent manner, which suggests that HQH induces the apoptosis of ALL cells via the Akt/FoxO1 pathway. CONCLUSION: HQH is a potential complementary agent for the treatment of acute lymphoblastic leukemia.


Asunto(s)
Apoptosis/efectos de los fármacos , Medicamentos Herbarios Chinos/farmacología , Proteína Forkhead Box O1/metabolismo , Antineoplásicos/farmacología , Astragalus propinquus , Proteína 11 Similar a Bcl2/metabolismo , Western Blotting , Caspasa 3/metabolismo , Puntos de Control del Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Citometría de Flujo , Humanos , Medicina Tradicional China , Fosforilación/efectos de los fármacos , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/patología , Proteínas Proto-Oncogénicas c-akt/metabolismo , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Regulación hacia Arriba/efectos de los fármacos , Proteína X Asociada a bcl-2/metabolismo
17.
Anesthesiology ; 124(6): 1296-310, 2016 06.
Artículo en Inglés | MEDLINE | ID: mdl-27187119

RESUMEN

BACKGROUND: Hibernation is an adaptation to extreme environments known to provide organ protection against ischemia-reperfusion (I/R) injury. An unbiased systems approach was utilized to investigate hibernation-induced changes that are characteristic of the hibernator cardioprotective phenotype, by comparing the myocardial proteome of winter hibernating arctic ground squirrels (AGS), summer active AGS, and rats subjected to I/R, and further correlating with targeted metabolic changes. METHODS: In a well-defined rodent model of I/R by deep hypothermic circulatory arrest followed by 3 or 24 h of reperfusion or sham, myocardial protein abundance in AGS (hibernating summer active) and rats (n = 4 to 5/group) was quantified by label-free proteomics (n = 4 to 5/group) and correlated with metabolic changes. RESULTS: Compared to rats, hibernating AGS displayed markedly reduced plasma levels of troponin I, myocardial apoptosis, and left ventricular contractile dysfunction. Of the 1,320 rat and 1,478 AGS proteins identified, 545 were differentially expressed between hibernating AGS and rat hearts (47% up-regulated and 53% down-regulated). Gene ontology analysis revealed down-regulation in hibernating AGS hearts of most proteins involved in mitochondrial energy transduction, including electron transport chain complexes, acetyl CoA biosynthesis, Krebs cycle, glycolysis, and ketogenesis. Conversely, fatty acid oxidation enzymes and sirtuin-3 were up-regulated in hibernating AGS, with preserved peroxisome proliferator-activated receptor-α activity and reduced tissue levels of acylcarnitines and ceramides after I/R. CONCLUSIONS: Natural cardioprotective adaptations in hibernators involve extensive metabolic remodeling, featuring increased expression of fatty acid metabolic proteins and reduced levels of toxic lipid metabolites. Robust up-regulation of sirtuin-3 suggests that posttranslational modifications may underlie organ protection in hibernating mammals.


Asunto(s)
Adaptación Fisiológica , Hibernación , Isquemia Miocárdica/fisiopatología , Reperfusión Miocárdica , Proteómica , Daño por Reperfusión/fisiopatología , Animales , Femenino , Masculino , Ratas , Ratas Endogámicas Dahl , Sciuridae
18.
Heart Surg Forum ; 19(6): E297-E302, 2016 12 22.
Artículo en Inglés | MEDLINE | ID: mdl-28054902

RESUMEN

INTRODUCTION: Pulmonary arterial hypertension (PAH) is a common and fatal complication of congenital heart disease (CHD). PAH-CHD increases the risk for postoperative complications. Recent evidence suggests that perioperative goal-directed hemodynamic optimization therapy (GDHOT) significantly improves outcomes in surgery patients. Standard GDHOT is based on major solution volume, vasodilators and inotropic therapy, while novel GDHOT is based on major vasopressor and inotropic therapy. Therefore, we tested whether standard or novel GDHOT improves surgical outcomes in PAH-CHD patients. METHODS: Forty PAH-CHD patients with a ventricular septal defect (VSD) and mean pulmonary arterial pressure (mPAP) >50 mmHg, who were scheduled for corrective surgery, were randomly assigned to 2 groups: SG (study group, n = 20) and CG (control group, n = 20). SG patients received perioperative hemodynamic therapy guided by novel GDHOT, while CG patients received standard GDHOT. Outcome data were recorded up to 28 days postoperatively. Ventilator time, length of ICU stay, and mortality were the primary endpoints. RESULTS: There were no significant differences in preoperative data, surgical procedure, and hospital mortality rates between the 2 groups. Time of mechanical ventilation and length of ICU stay were significantly shorter in SG patients compared to CG patients (P < .05, n = 20). Patients in SG showed a significantly increased systemic vascular resistance index and decreased cardiac index, but no change in pulmonary vascular resistance index at 12 and 24 hours after surgery compared to the controls (P < .05). Patients in SG had significantly decreased PAP, pulmonary arterial pressure/systemic arterial pressure (Pp/Ps), and RVSWI (right ventricular stroke work index) at 12 and 24 hours after surgery (P < .05, respectively). Patients in SG also showed significantly decreased central venous pressure at 4, 12, and 24 hours after surgery compared to those treated with standard protocol (P < .05). CONCLUSION: Our study provides clinical evidence that perioperative goal-directed hemodynamic optimization therapy based on major vasopressor is associated with reduced duration of postoperative respiratory support, and length of ICU stay in PAH-CHD patients undergoing elective surgery. These outcomes, then, may be linked to improved hemodynamics and preservation of right ventricular dynamic function.


Asunto(s)
Procedimientos Quirúrgicos Cardíacos/métodos , Defectos del Tabique Interventricular/complicaciones , Hemodinámica/fisiología , Hipertensión Pulmonar/tratamiento farmacológico , Vasodilatadores/uso terapéutico , Adolescente , Procedimientos Quirúrgicos Electivos/métodos , Femenino , Estudios de Seguimiento , Defectos del Tabique Interventricular/diagnóstico , Defectos del Tabique Interventricular/cirugía , Humanos , Hipertensión Pulmonar/etiología , Hipertensión Pulmonar/fisiopatología , Masculino , Proyectos Piloto , Estudios Prospectivos , Índice de Severidad de la Enfermedad , Resultado del Tratamiento
19.
Analyst ; 140(6): 1913-20, 2015 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-25656431

RESUMEN

Electrochemical detection of dopamine (DA) plays an important role in medical diagnosis. In this paper, tremella-like graphene-Au (t-GN-Au) composites were synthesized by a one-step hydrothermal method for selective detection of DA. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Raman spectroscopy, and Fourier transform infrared (FTIR) spectroscopy were used to characterize as-prepared t-GN-Au composites. The t-GN-Au composites were directly used for the determination of DA via cyclic voltammetry (CV) and the chronoamperometry (CA) technique. CA measurement gave a wide linear range from 0.8 to 2000 µM, and the detection limit of 57 nM (S/N = 3) for DA. The mechanism and the heterogeneous electron transfer kinetics of the DA oxidation were discussed in the light of rotating disk electrode (RDE) experiments. Moreover, the modified electrode was applied to the determination of DA in human urine and serum samples.


Asunto(s)
Dopaminérgicos/sangre , Dopaminérgicos/orina , Dopamina/sangre , Dopamina/orina , Técnicas Electroquímicas/métodos , Oro/química , Grafito/química , Técnicas Biosensibles/métodos , Humanos , Límite de Detección
20.
Pediatr Transplant ; 19(5): 563-70, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26058853

RESUMEN

The success of treating a wide variety of pediatric diseases with HSCT, hematologic malignancies in particular, has resulted in an increased number of long-term survivors. This study is the first large-scale, multicentre report that describes the evolution of pediatric HSCTs in China during the period of 1998-2012. Of all 1052 patients, 266 cases were treated with autologous HSCs and 786 used allogeneic HSCs. The disease indications for HSCTs mainly included leukemias, lymphoma, solid tumors, and non-malignant disorders. The total number of HSCTs, especially unrelated donor transplants, appeared to be increasing year by year. For patients with neuroblastoma, the therapeutic efficacy seemed to be poor, with a five-yr OS and DFS rate of 34.5 ± 14.3% and 20.7 ± 9.6%, respectively. In contrast, the survival of patients with SAA was prominently improved, and their five-yr OS and DFS rates were 82.8 ± 4% and 80.7 ± 4.1%, respectively. Patients who received cord blood transplants had a lower incidence of acute GVHD than that of PB and/or BM transplants from unrelated donors. This report offers us a valuable resource for evaluating the changes in HSCTs in China over the past 14 yr.


Asunto(s)
Enfermedad Injerto contra Huésped/epidemiología , Neoplasias Hematológicas/epidemiología , Neoplasias Hematológicas/terapia , Trasplante de Células Madre Hematopoyéticas/estadística & datos numéricos , Trasplante de Células Madre Hematopoyéticas/tendencias , Adolescente , Niño , Preescolar , China , Trasplante de Células Madre de Sangre del Cordón Umbilical/efectos adversos , Supervivencia sin Enfermedad , Femenino , Geografía , Neoplasias Hematológicas/mortalidad , Humanos , Lactante , Masculino , Estudios Retrospectivos , Resultado del Tratamiento , Donante no Emparentado
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA