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1.
Int Orthop ; 48(3): 683-692, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37740768

RESUMEN

PURPOSE: Total knee arthroplasty is the main method for the treatment of advanced haemophilic knee arthritis. Due to the particularity of hemophilia, the blood management plan is the focus of the perioperative period for haemophilia patients. This study aimed to investigate the clinical effect and safety of intra-articular injection of tranexamic acid in patients with haemophilia. METHODS: This is a retrospective study. According to whether tranexamic acid is used or not, patients are divided into tranexamic acid group (n=30) and non-tranexamic acid group (n=29). Total blood loss, intraoperative blood loss, complete blood count, total amount of coagulation factor VIII (FVIII) usage, coagulation biomarkers, inflammatory biomarkers, knee range of motion, knee joint function, pain status, complication rate, and patient satisfaction were assessed and compared at a mean follow-up of 16 months. RESULTS: Injecting tranexamic acid into the knee joint cavity can effectively reduce the hidden blood loss and total blood loss (P<0.001), and reduce the patient's early postoperative inflammation biomarkers, pain status, and limb swelling. Therefore, the patient can obtain a better range of motion following total knee arthroplasty. In the long run, in terms of joint function and surgical satisfaction, there are no statistically significant differences. In addition, there are no statistically significant differences between the two groups of patients in terms of the total amount of FVIII usage, length of stay, and hospitalization expenses. CONCLUSION: In patients with haemophilia, intra-articular injection of tranexamic acid during total knee arthroplasty can effectively reduce postoperative blood loss, early postoperative inflammation levels, pain and limb swelling, and enable patients to receive higher-quality rehabilitation exercises to get better joint function. Previous studies on TKA in haemophilic patients have already demonstrated the efficacy of intra-articular injections of TXA in reducing postoperative blood loss. Our study confirms this efficacy.


Asunto(s)
Antifibrinolíticos , Artritis , Artroplastia de Reemplazo de Rodilla , Hemofilia A , Ácido Tranexámico , Humanos , Ácido Tranexámico/uso terapéutico , Artroplastia de Reemplazo de Rodilla/efectos adversos , Artroplastia de Reemplazo de Rodilla/métodos , Estudios Retrospectivos , Hemofilia A/complicaciones , Hemofilia A/tratamiento farmacológico , Antifibrinolíticos/uso terapéutico , Pérdida de Sangre Quirúrgica/prevención & control , Hemorragia Posoperatoria/etiología , Inyecciones Intraarticulares , Inflamación/complicaciones , Biomarcadores , Dolor
2.
J Environ Manage ; 354: 120353, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38377756

RESUMEN

Waste beverages are utilized as resources in various valuable, albeit energy-consuming, waste-to-energy processes. There is a growing need for alternative cost-effective methods to harness their potential. This study explored the feasibility of employing waste beverages as feedstock for the counterpart component of a TiO2-based composite photocatalyst. Several commonly available carbonated soft drinks from the Japanese market have been investigated to achieve this goal. The investigation revealed that a mild hydrothermal treatment condition could transform all examined beverages into carbonaceous materials suitable for fabricating a core-shell structure with TiO2, resulting in a remarkably efficient visible light active photocatalyst. Notably, a pH-adjusted photocatalyst derived from Coca Cola® exhibited superior visible light photodegradability toward dye molecules and enhanced bactericidal efficacy compared to the counterpart derived from pure sucrose. The heightened visible light photocatalytic activity can be attributed to the distinctive carboxy-rich surface functional groups, based on the findings of experimental analyses and density functional theory calculations. The bidentate-type bonding of these groups with TiO2 induces a modified interfacial bond structure that facilitates the efficient transfer of photoexcited carriers. This study presents a novel avenue for the effective utilization and recycling of waste beverages, and adds value under environmentally benign conditions.


Asunto(s)
Carbono , Nanoestructuras , Luz , Nanoestructuras/química , Antibacterianos , Bebidas
3.
Chem Rec ; 19(7): 1393-1406, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-30548140

RESUMEN

The enhancement of photocatalytic activity of TiO2 can be made either by promoting absorption efficiency of photon energy or by reducing recombination losses of photogenerated charge carriers, for which fabrication of nanocomposite structure with carbon materials is an optional selection. Among various nanocarbons, graphene (G), graphene oxide (GO), and reduced graphene oxide (rGO) are more favorable as the counterpart materials because they can provide availability of both obverse and reverse surface, thus doubling effective sites for adsorption, loading of nanoparticles, and interfacial interaction with the loaded nanoparticles. Composition of G/GO with titania, therefore, is a hopeful strategy for achieving synergy or cooperative effect in photocatalysis. In this personal account, we focus on the background and methodology of several soft chemical approaches that we have utilized up to date to fabricate nanocomposites of G/GO and titania, aiming to shed light on the importance of designing of nanocomposite structure for enhancing photocatalysis. In addition, we emphasize the role of interfacial interaction between carbon and titania by exemplifying a hybridized photocatalyst based on inexpensive biomass-derived carbon sphere (CS), and demonstrate that it is a crucial influential factor underlying an enhanced visible light photocatalysis. CS can be a better selection as a counterpart component than G/GO, whose core-shell composing structure with titania (TiO2 @CS) can efficiently induce charge transfer so as to achieve a much higher photocatalytic performance under visible light illumination as compared to the composite of rGO and titania.

4.
J Environ Manage ; 162: 326-33, 2015 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-26265601

RESUMEN

This investigation evaluated the adsorption behavior of the antiviral drugs of oseltamivir (OE) and its metabolites (i.e., oseltamivir carboxylate (OC)) on three types of carbon nanotubes (CNTs) including single-walled CNT (SWCNT), multi-walled CNT (MWCNT), and carboxylated SWCNT (SWCNT-COOH). CNTs can efficiently remove more than 90% of the OE and OC from aqueous solution when the initial concentration was lower than 10(-4) mmol/L. The Polanyi-Manes model depicted the adsorption isotherms of OE and OC on CNTs better than the Langmuir and Freundlich models. The properties of OE/OC and the characteristics of CNTs, particularly the oxygen functional groups (e.g., SWCNT-COOH) played important roles during the adsorption processes. OE showed a higher adsorption affinity than OC. By comparing the different adsorbates adsorption on each CNT and each adsorbate adsorption on different CNTs, the adsorption mechanisms of hydrophobic interaction, electrostatic interaction, van der Waals force, and H-bonding were proposed as the contributing factors for OE and OC adsorption on CNTs. Particularly, for verifying the contribution of electrostatic interaction, the changes of adsorption partition efficiency (Kd) of OE and OC on CNTs were evaluated by varying pH from 2 to 11 and the importance of isoelectric point (pHIEP) of CNTs on OE and OC adsorption was addressed.


Asunto(s)
Antivirales/química , Contaminantes Ambientales/química , Nanotubos de Carbono/química , Oseltamivir/análogos & derivados , Adsorción , Ácidos Carboxílicos , Concentración de Iones de Hidrógeno , Interacciones Hidrofóbicas e Hidrofílicas , Modelos Teóricos , Oseltamivir/química
5.
J Hepatocell Carcinoma ; 11: 427-442, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38440051

RESUMEN

Background: Currently, it is still confused whether preoperative aminotransferase-to-platelet ratio (APRI) and gamma-glutamyl transferase-to-platelet ratio (GPR) can predict microvascular invasion (MVI) in solitary hepatocellular carcinoma (HCC). We aimed to develop and validate a machine-learning integration model for predicting MVI using APRI, GPR and gadoxetic acid disodium (Gd-EOB-DTPA) enhanced MRI. Methods: A total of 314 patients from XinQiao Hospital of Army Medical University were divided chronologically into training set (n = 220) and internal validation set (n = 94), and recurrence-free survival was determined to follow up after surgery. Seventy-three patients from Chongqing University Three Gorges Hospital and Luzhou People's Hospital served as external validation set. Overall, 387 patients with solitary HCC were analyzed as whole dataset set. Least absolute shrinkage and selection operator, tenfold cross-validation and multivariate logistic regression were used to gradually filter features. Six machine-learning models and an ensemble of the all models (ENS) were built. The area under the receiver operating characteristic curve (AUC) and decision curve analysis were used to evaluate model's performance. Results: APRI, GPR, HBPratio3 ([liver SI‒tumor SI]/liver SI), PLT, peritumoral enhancement, non-smooth margin and peritumoral hypointensity were independent risk factors for MVI. Six machine-learning models showed good performance for predicting MVI in training set (AUCs range, 0.793-0.875), internal validation set (0.715-0.832), external validation set (0.636-0.746) and whole dataset set (0.756-0.850). The ENS achieved the highest AUCs (0.879 vs 0.858 vs 0.839 vs 0.851) in four cohorts with excellent calibration and more net benefit. Subgroup analysis indicated that ENS obtained excellent AUCs (0.900 vs 0.809 vs 0.865 vs 0.908) in HCC >5cm, ≤5cm, ≤3cm and ≤2cm cohorts. Kaplan‒Meier survival curves indicated that ENS achieved excellent stratification for MVI status. Conclusion: The APRI and GPR may be new potential biomarkers for predicting MVI of HCC. The ENS achieved optimal performance for predicting MVI in different sizes HCC and may aid in the individualized selection of surgical procedures.

6.
Acad Radiol ; 2024 Mar 16.
Artículo en Inglés | MEDLINE | ID: mdl-38494348

RESUMEN

BACKGROUND: Hepatocellular carcinoma (HCC) is an inflammatory cancer. We aimed to explore whether preoperative inflammation biomarkers compared to the gadoxetic acid disodium (Gd-EOB-DTPA) enhanced MRI can add complementary value for predicting HCC pathological grade, and to develop a dynamic nomogram to predict solitary HCC pathological grade. METHODS: 331 patients from the Institution A were divided chronologically into the training cohort (n = 231) and internal validation cohort (n = 100), and recurrence-free survival (RFS) was determined to follow up after surgery. 79 patients from the Institution B served as the external validation cohort. Overall, 410 patients were analyzed as the complete dataset cohort. Least absolute shrinkage and selection operator (LASSO) and multivariate Logistic regression were used to gradually filter features for model construction. The area under the receiver operating characteristic curve (AUC) and decision curve analysis were used to evaluate model's performance. RESULTS: Five models of the inflammation, imaging, inflammation+AFP, inflammation+imaging and nomogram were developed. Adding inflammation to imaging model can improve the AUC in training cohort (from 0.802 to 0.869), internal validation cohort (0.827 to 0.870), external validation cohort (0.740 to 0.802) and complete dataset cohort (0.739 to 0.788), and obtain more net benefit. The nomogram had excellent performance for predicting high-grade HCC in four cohorts (AUCs: 0.882 vs. 0.869 vs. 0.829 vs. 0.806) with a good calibration, and accessed at https://predict-solitaryhccgrade.shinyapps.io/DynNomapp/. Additionally, the nomogram obtained an AUC of 0.863 (95% CI 0.797-0.913) for predicting high-grade HCC in the HCC≤ 3 cm. Kaplan-Meier survival curves demonstrated that the nomogram owned excellent stratification for HCC grade (P < 0.0001). CONCLUSION: This easy-to-use dynamic online nomogram hold promise for use as a noninvasive tool in prediction HCC grade with high accuracy and robustness.

7.
Pediatr Res ; 73(5): 612-620, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23419538

RESUMEN

BACKGROUND: We showed that intrauterine growth restriction (IUGR) increases distal airspace wall thickness at birth (postnatal age 0; P0) in rat pups (saccular stage of lung development). However, that report did not assess whether the saccular phenotype persisted postnatally or occurred in males or females, nor did the report identify a potential molecular pathway for the saccular phenotype at P0. We hypothesized that IUGR persistently delays alveolar formation and disrupts retinoic acid receptor (RAR) mRNA and protein levels in the lung of rat pups in a postnatal age- and sex-specific manner. METHODS: IUGR was induced in pregnant rats by bilateral uterine artery ligation. Alveolar formation and expression of RARα, -ß, and -γ were quantified at P0, P6 (alveolar stage), and P21 (postalveolarization). RESULTS: IUGR increased distal airspace wall thickness in female pups at P0 only. IUGR did not affect male pups at any age. IUGR transiently increased lung RAR-ß protein abundance, which inhibits alveolar formation, at P0 in female pups. Serum retinol concentration was normal at all ages. CONCLUSION: IUGR alone is not sufficient to persistently delay postnatal alveolar formation or disrupt expression of RARs. We speculate that for IUGR to delay alveolar formation postnatally, a second insult is necessary.


Asunto(s)
Retardo del Crecimiento Fetal , Pulmón/metabolismo , Alveolos Pulmonares/embriología , Receptores de Ácido Retinoico/metabolismo , Animales , Femenino , Pulmón/embriología , Embarazo , Ratas
8.
Acta Pharmacol Sin ; 34(11): 1374-80, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24122008

RESUMEN

MicroRNAs (miRNAs) are small non-coding RNA molecules, whose primary function is to regulate gene expression at the post-transcriptional/translational levels. MiRNAs play crucial roles in normal biological processes and are commonly dys-regulated in human diseases. Stem cells are regarded as the "mother" cells of all types of differentiated cells that comprise tissues and organs of the body. A novel hypothesis proposes that tumors are composed of heterogeneous cells derived from cancer stem cells, which have self-renewal and differentiation capabilities similar to those of normal stem cells. Cancer stem cells have been isolated and characterized from various tumors. Given recent studies supporting the critical regulatory roles of miRNAs in the self-renewal and differentiation of cancer stem cells, better understanding the functions of miRNAs will provide invaluable insights into the prevention of tumorigenesis and tumor progression. In this review, we will summarize the research progress in the study of miRNAs involved in the self-renewal and differentiation of cancer stem cells.


Asunto(s)
MicroARNs/genética , Neoplasias/patología , Células Madre Neoplásicas/metabolismo , Animales , Diferenciación Celular , Progresión de la Enfermedad , Regulación Neoplásica de la Expresión Génica , Humanos , Neoplasias/genética , Procesamiento Postranscripcional del ARN
9.
Front Med (Lausanne) ; 10: 1200592, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37601800

RESUMEN

Objective: In order to examine the relationship between 25-hydroxyl vitamin D and knee osteoarthritis (KOA), a meta-analysis of 8 randomized controlled trials (RCTs) publications was hereby performed. Methods: For the purpose of finding pertinent research, the databases of PubMed, Embase and the Cochrane Library were searched. Factors including tibial cartilage volume, joint space width (JSW), synovial fluid volume, and Western Ontario and McMaster Universities Arthritis Index (WOMAC) were correspondingly evaluated, and the results were expressed using SMD and 95% confidence intervals (CI). Results: The present meta-analysis evaluated the effects of vitamin D supplementation in patients with knee osteoarthritis, with 3,077 patients included. The results showed that vitamin D administration had a statistically significant impact on the amount of synovial fluid, Visual Analog Scale (VAS) and tibial cartilage. The pain and function scales of the WOMAC scale presented a statistically significant difference, and there was no discernible difference between the vitamin D and placebo groups in the stiffness scale. Additionally, bone marrow lesions and alterations in the diameter of the joint space were not influenced by the administration of vitamin D, and according to a subgroup study, a daily vitamin D supplement containing more than 2,000 IU significantly slowed the development of synovial tissue. Conclusion: Vitamin D supplementation did benefit those suffering from knee discomfort and knee dysfunction. Systematic review registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022332033, identifier: CRD42022332033.

10.
J Colloid Interface Sci ; 608(Pt 2): 1638-1651, 2022 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-34749138

RESUMEN

Sacrifiers-promoted photocatalysis is a useful way to achieve high efficiency photoreduction and photocatalytic hydrogen production for photocatalysts of weak reductive power such as TiO2. Herein we report a new method to fabricate a unique dyadic hybrid consisting of closely compacted crystalline (anatase) and titanium glycerolate (TiG)-derived organic group-retained amorphous nanoparticles to validate adsorption-stored sacrifiers-promoted photocatalysis instead of using sacrifiers in bulk solution. It was found that ascorbic acid (AA)-modified TiG prepared at a small fraction of glycerol, characterized by peculiar cocoon/open nanocontainer-type morphologies, varieties of oxygen containing groups, and remarkably high specific surface area, is suitable for precursing such hybrids. AA can change crystallization processes and particle morphologies by terminating chain linkages in TiG structure, which increases porosity and brings about visible light responsive photocatalysis for the dyadic hybrid. Benefiting from good adsorption affinity to organic sacrifiers, the sacrifier-prestored hybrid can catalyze significantly enhanced photoreduction with good reproducibility toward dye molecules via the synergy of sacrifier enrichment and photocatalysis. AA modified TiG also exhibits good self-reducibility enabling pre-loading of highly dispersed and localized platinum nanoparticles, and the resulted dyadic hybrid facilitates photocatalytic hydrogen production of extremely higher turn-off frequency and better impurities interference-resistivity compared to the P25-based commercial catalyst.


Asunto(s)
Nanopartículas del Metal , Titanio , Catálisis , Fotólisis , Platino (Metal) , Reproducibilidad de los Resultados
11.
Front Surg ; 9: 1067306, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36684182

RESUMEN

Background: Total knee arthroplasty (TKA) is recommended for haemophilic patients with end-stage arthritis. TKA combined with a one-stage extraarticular osteotomy is uncommon in the treatment of haemophilic arthritis (HA) with severe extra-articular deformities (EADs) and a history of inhibitors under the guidance of a patient-specific cutting guide (PSI). Case presentation: We reported a 20-year-old male patient with severe haemophilia, limited knee functionality, a 30° sagittal deformity on the femoral side and a history of inhibitors. We adopted the Van Creveld protocol to decrease the inhibitors. TKA and extra-articular osteotomy (EAO) were performed simultaneously and sequentially under the guidance of PSI. An appropriate central alignment of the lower limb was restored by using cement prostheses with antibiotics and femur shaft locking compression plates. The last follow-up showed that the knee function was good, the VAS score was 0, the WOMAC score was 18 and the ROM was 0°-95°. Conclision: Regular haematology management can reduce the perioperative bleeding risk in haemophilic patients treated with inhibitors. PSI plays an important role in guiding the TKA and EAO of end-stage HA patients with severe EAD.

12.
Pediatr Res ; 70(5): 462-6, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-21814155

RESUMEN

The mechanism underlying the potentially beneficial effects of the "gentler" modes of ventilation on chronic lung disease (CLD) of the premature infant is not known. We have previously demonstrated that alveolar parathyroid hormone-related protein-peroxisome proliferator-activated receptorγ (PTHrP-PPARγ) signaling is critically important in alveolar formation, and this signaling pathway is disrupted in hyperoxia- and/or volutrauma-induced neonatal rat lung injury. Whether the same paradigm is also applicable to CLD, resulting from prolonged intermittent mandatory ventilation (IMV), and whether differential effects of the mode of ventilation on the PTHrP-PPARγ signaling pathway explain the potential benefits of the "gentler" modes of ventilation are not known. Using a well-established preterm lamb model of neonatal CLD, we tested the hypothesis that ventilatory support using high-frequency nasal ventilation (HFNV) promotes alveolar PTHrP-PPARγ signaling, whereas IMV inhibits it. Preterm lambs managed by HFNV or IMV for 21 d following preterm delivery at 132-d gestation were studied by Western hybridization and immunofluorescence labeling for key markers of alveolar homeostasis and injury/repair. In lambs managed by IMV, the abundance of key homeostatic alveolar epithelial-mesenchymal markers was reduced, whereas it was significantly increased in the HFNV group, providing a potential molecular mechanism by which "gentler" modes of ventilation reduce neonatal CLD.


Asunto(s)
Animales Recién Nacidos , Ventilación de Alta Frecuencia/métodos , Transducción de Señal/fisiología , Lesión Pulmonar Inducida por Ventilación Mecánica/prevención & control , Animales , Biomarcadores/análisis , Western Blotting , Técnica del Anticuerpo Fluorescente , Oxígeno/administración & dosificación , PPAR gamma/metabolismo , Proteína Relacionada con la Hormona Paratiroidea/metabolismo , Ovinos
13.
Am J Physiol Lung Cell Mol Physiol ; 299(1): L59-72, 2010 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-20382748

RESUMEN

Neonatal chronic lung disease is characterized by failed formation of alveoli and capillaries, and excessive deposition of matrix elastin, which are linked to lengthy mechanical ventilation (MV) with O(2)-rich gas. Vitamin A supplementation has improved respiratory outcome of premature infants, but there is little information about the structural and molecular manifestations in the lung that occur with vitamin A treatment. We hypothesized that vitamin A supplementation during prolonged MV, without confounding by antenatal steroid treatment, would improve alveolar secondary septation, decrease thickness of the mesenchymal tissue cores between distal air space walls, and increase alveolar capillary growth. We further hypothesized that these structural advancements would be associated with modulated expression of tropoelastin and deposition of matrix elastin, phosphorylated Smad2 (pSmad2), cleaved caspase 3, proliferating cell nuclear antigen (PCNA), VEGF, VEGF-R2, and midkine in the parenchyma of the immature lung. Eight preterm lambs (125 days' gestation, term approximately 150 days) were managed by MV for 3 wk: four were treated with daily intramuscular Aquasol A (vitamin A), 5,000 IU/kg, starting at birth; four received vehicle alone. Postmortem lung assays included quantitative RT-PCR and in situ hybridization, immunoblot and immunohistochemistry, and morphometry and stereology. Daily vitamin A supplementation increased alveolar secondary septation, decreased thickness of the mesenchymal tissue cores between the distal air space walls, and increased alveolar capillary growth. Associated molecular changes were less tropoelastin mRNA expression, matrix elastin deposition, pSmad2, and PCNA protein localization in the mesenchymal tissue core of the distal air space walls. On the other hand, mRNA expression and protein abundance of VEGF, VEGF-R2, midkine, and cleaved caspase 3 were increased. We conclude that vitamin A treatment partially improves lung development in chronically ventilated preterm neonates by modulating expression of tropoelastin, deposition of elastin, and expression of vascular growth factors.


Asunto(s)
Enfermedades Pulmonares/dietoterapia , Enfermedades Pulmonares/fisiopatología , Enfermedades Pulmonares/veterinaria , Pulmón , Alveolos Pulmonares , Vitamina A , Vitaminas , Animales , Animales Recién Nacidos , Enfermedad Crónica , Suplementos Dietéticos , Elastina/genética , Elastina/metabolismo , Femenino , Edad Gestacional , Pulmón/efectos de los fármacos , Pulmón/crecimiento & desarrollo , Pulmón/patología , Enfermedades Pulmonares/patología , Embarazo , Nacimiento Prematuro , Alveolos Pulmonares/efectos de los fármacos , Alveolos Pulmonares/crecimiento & desarrollo , Alveolos Pulmonares/ultraestructura , Intercambio Gaseoso Pulmonar , Respiración Artificial , Ovinos , Tropoelastina/genética , Factor A de Crecimiento Endotelial Vascular/genética , Factor A de Crecimiento Endotelial Vascular/metabolismo , Receptor 2 de Factores de Crecimiento Endotelial Vascular/genética , Receptor 2 de Factores de Crecimiento Endotelial Vascular/metabolismo , Vitamina A/sangre , Vitamina A/farmacología , Vitamina A/uso terapéutico , Vitaminas/farmacología , Vitaminas/uso terapéutico
14.
Langmuir ; 26(9): 6681-8, 2010 May 04.
Artículo en Inglés | MEDLINE | ID: mdl-20356035

RESUMEN

Carbon nanosheet (CNS)-Pd nanosized particle (NP) composites were synthesized by using graphite oxide (GO) and bis(ethylenediamine)palladium(II) (Pd(en)(2)(2+)) as the precursors, and their structure and adsorption properties were examined. It was found that the Pd(en)(2)(2+) complex ions can be intercalated into GO layers highly efficiently to form a layered structure containing a large amount of Pd (approximately 12 wt %). By the subsequent chemical reduction, Pd NPs (2-6 nm in size) are well dispersed between CNS to form a CNS-Pd NP composite and serve as spacers to increase the porosity of the composite. Hydrogen adsorption results demonstrate that both Pd NPs and CNS play important roles in hydrogen adsorption, particularly at a lower temperature and for CNS with deficient sites, which bring about a H(2) adsorption greater than those on other Pd-loaded nanocarbon materials reported so far. The unique composite nanostructure having large contents of Pd NPs (20-25 wt %) stabilized by CNSs is hopeful to be applied to the fields of H(2)-related catalysis, sensing, and so forth.

15.
Am J Respir Crit Care Med ; 178(4): 407-18, 2008 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-18556628

RESUMEN

RATIONALE: Bronchopulmonary dysplasia (BPD) is a frequent cause of morbidity in preterm infants that is characterized by prolonged need for ventilatory support in an intensive care environment. BPD is characterized histopathologically by persistently thick, cellular distal airspace walls. In normally developing lungs, by comparison, remodeling of the immature parenchymal architecture is characterized by thinning of the future alveolar walls, a process predicated on cell loss through apoptosis. OBJECTIVES: We hypothesized that minimizing lung injury, using high-frequency nasal ventilation to provide positive distending pressure with minimal assisted tidal volume displacement, would increase apoptosis and decrease proliferation among mesenchymal cells in the distal airspace walls compared with a conventional mode of support (intermittent mandatory ventilation). METHODS: Accordingly, we compared two groups of preterm lambs: one group managed by high-frequency nasal ventilation and a second group managed by intermittent mandatory ventilation. Each group was maintained for 3 days. MEASUREMENTS AND MAIN RESULTS: Oxygenation and ventilation targets were sustained with lower airway pressures and less supplemental oxygen in the high-frequency nasal ventilation group, in which alveolarization progressed. Thinning of the distal airspace walls was accompanied by more apoptosis, and less proliferation, among mesenchymal cells of the high-frequency nasal ventilation group, based on morphometric, protein abundance, and mRNA expression indices of apoptosis and proliferation. CONCLUSIONS: Our study shows that high-frequency nasal ventilation preserves the balance between mesenchymal cell apoptosis and proliferation in the distal airspace walls, such that alveolarization progresses.


Asunto(s)
Apoptosis/fisiología , Displasia Broncopulmonar/patología , División Celular/fisiología , Presión de las Vías Aéreas Positiva Contínua , Ventilación de Alta Frecuencia , Ventilación con Presión Positiva Intermitente , Mesodermo/patología , Alveolos Pulmonares/patología , Animales , Animales Recién Nacidos , Caspasa 3/metabolismo , Edad Gestacional , Humanos , Recién Nacido , Oxígeno/sangre , Antígeno Nuclear de Célula en Proliferación/metabolismo , Ovinos , Volumen de Ventilación Pulmonar/fisiología
16.
IEEE Trans Image Process ; 18(7): 1477-86, 2009 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-19473944

RESUMEN

A novel fast and adaptive method for synthetic aperture radar (SAR) superresolution imaging is developed. Based on the point scattering model in the phase history domain, a dictionary is constructed so that the superresolution imaging process can be converted to a problem of sparse parameter estimation. The approximate orthogonality of this dictionary is exploited by theoretical derivation and experimental verification. Based on the orthogonality of the dictionary, we propose a fast algorithm for basis selection. Meanwhile, a threshold for obtaining the number and positions of the scattering centers is determined automatically from the inner product curves of the bases and observed data. Furthermore, the sensitivity of the threshold on estimation performance is analyzed. To reduce the burden of mass calculation and memory, a simplified superresolution imaging process is designed according to the characteristics of the imaging parameters. The experimental results of the simulated images and an MSTAR image illustrate the validity of this method and its robustness in the case of the high noise level. Compared with the traditional regularization method with the sparsity constraint, our proposed method suffers less computation complexity and has better adaptability.

17.
ACS Omega ; 4(8): 12995-13004, 2019 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-31460426

RESUMEN

Silicalite-1-type zeolites with unique intracrystal holes or cracks were successfully prepared using a cellulose nanofiber (CNF) as an additional mediating material, and their vapor phase adsorption properties toward methyl tert-butyl ether (MTBE) and n-nitrosodimethylamine (NDMA) were examined. It was found that the mixing protocol of CNF and structure-directing agents (SDAs), the addition amount of CNF, and the CNF/SDAs amount ratio play important roles in forming the holed silicalite-1. The synthesis route that preliminarily mixes CNF with SDAs in a series of controlled conditions is particularly beneficial for the formation of the holed silicalite-1 with mesoporosity and larger pores because the CNF-SDAs composite structure benefits the zeolite growth closely encompassing CNF inside the crystal structure. It also promotes the preferential formation of the orthorhombic phase vicinal to the CNF surface, namely, the surface of the formed internal holes or cracks, with the twin-type crystal size reduced as compared to the non-CNF-templated sample. On the contrary, the synthesis route that mixes CNF with SDAs-silicate composite ions tends to modify the twin-type crystal shape at the same time to form small but uniform well-crystallized particles with less holes or cracks and a dominative monoclinic phase. It was considered that both the inter-subunit structural defect and silanol defect whose content is increased with CNF addition influence the adsorptivity of MTBE and NDMA. Owing to the small twin-type crystal size, the smaller crystal subunits, and the favored short path from the surface of internal holes or cracks, the holed silicalite-1 derived from the CNF and SDA premixture assures the easiest access of adsorbate molecules to the most energetically favored sites and is most appropriate for the adsorption of both MTBE and NDMA among the examined zeolites.

18.
Sci Rep ; 9(1): 1387, 2019 02 04.
Artículo en Inglés | MEDLINE | ID: mdl-30718694

RESUMEN

Multiple sclerosis (MS) is an autoimmune disease characterized by multiple lesions in the brain and spinal cord. We used RNA sequencing to identify microbial sequences and characterize human gene expression patterns in 30 human brain biopsy specimens. RNAs which aligned to known microbial taxa, were significantly enriched in 10 of 12 primary demyelination (MS) brain specimens compared to a group of 15 epilepsy controls, leading to a list of 29 MS microbial candidate genera from 11 different phyla. Most of the candidate MS microbes are anaerobic bacteria. While there were some shared candidates, each of the 10 MS samples with significant microbial RNA enrichment had a distinct set microbial candidates. The fraction of microbial sequencing reads was greater for the MS group (128.8 PPM) compared to the controls (77.4 PPM, p = 0.016). Bacterial peptidoglycan was demonstrated in brain tissue sections from several MS subjects. Human gene expression analysis showed increased expression of inflammation-related pathways in the MS group. This data shows that demyelinating brain lesions are associated with the presence of microbial RNA sequences and bacterial antigen. This suggests that MS is triggered by the presence of a diverse set of microbes within a lesion.


Asunto(s)
Antígenos Bacterianos/metabolismo , Encéfalo/microbiología , Encéfalo/patología , Pared Celular/metabolismo , Enfermedades Desmielinizantes/microbiología , Adolescente , Adulto , Anciano , Femenino , Regulación de la Expresión Génica , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Masculino , Persona de Mediana Edad , Esclerosis Múltiple/genética , Esclerosis Múltiple/microbiología , Esclerosis Múltiple/patología , Filogenia , Adulto Joven
19.
J Colloid Interface Sci ; 322(2): 497-504, 2008 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-18406418

RESUMEN

Titanium dioxide nanocrystalline particles were synthesized by peroxo titanium acid (PTA) approach from titanium alkoxide and inorganic salt precursors, and their structural and surface properties, porosities, and photocatalytic activities were comparatively examined by XRD, TG/DTA, DRIFT, UV-vis, low temperature N(2) adsorption, and methyl orange (MO) degradation. It was found that nanoparticles with single anatase phase can be obtained from alkoxide precursor even near room temperature if synthesis conditions are appropriately controlled. PTA-derived anatase nanoparticles from titanium alkoxide precursor have smaller crystalline sizes and better porosities, and contain less amount of peroxo group and no organic impurities as compared to those from TiCl(4) precursor. The advantages in structural property, porosity, and surface properties (few deficiencies) lead to a much better photocatalytic activity for TiO(2) nanoparticles from titanium alkoxide precursor in comparison with those from TiCl(4) precursor.


Asunto(s)
Nanopartículas del Metal/química , Titanio/química , Adsorción , Catálisis , Nitrógeno , Óxidos/química , Fotoquímica , Espectrofotometría , Espectroscopía Infrarroja por Transformada de Fourier , Termodinámica , Difracción de Rayos X
20.
Chemosphere ; 131: 41-7, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25765262

RESUMEN

The photocatalytic degradation of the antiviral drug Tamiflu (oseltamivir phosphate, OP) by TiO2 - P25, ST-01 and ATO was investigated in aqueous solution under ultraviolet (UV-A) irradiation. The photocatalysis of OP is well described by pseudo-first-order kinetics with r2>98.0% for all cases. The kinetic constant of P25 with 80% anatase and 20% rutile (0.040 min(-1)) is 4 and 10 times higher than that of ATO and ST-01 with 100% purity of anatase, respectively. We examined the effects of the catalyst loading and initial OP concentration on the photodegradation of OP, and used potassium iodine, isopropanol, and calcium fluorine as radical quenchers to evaluate the contributions of the hydroxyl radical (OH) and photo hole (h+) in the photodegradation. Results confirmed that 80% of the contribution came from the OH species. Although more than 95% of the OP (21 µM) was removed after 80 min of UV-A irradiation with 20 and 100 mg L(-1) P25, the removal efficiencies of total organic carbon (TOC) were only 45.6% and 67.0%, respectively, after 360 min UV-A irradiation. Based on an intermediate analysis by HPLC coupled with a triple quadrupole spectrometer and an ion trap mass spectrometer, typical intermediate species such as hydration derivatives, hydroxyl substitutes and keto-derivatives were identified and possible degradation pathways of OP by P25 were proposed.


Asunto(s)
Antivirales/análisis , Oseltamivir/análisis , Fotólisis , Titanio/química , Contaminantes Químicos del Agua/análisis , Antivirales/química , Antivirales/efectos de la radiación , Catálisis , Cinética , Modelos Teóricos , Estructura Molecular , Oseltamivir/química , Oseltamivir/efectos de la radiación , Rayos Ultravioleta , Contaminantes Químicos del Agua/química , Contaminantes Químicos del Agua/efectos de la radiación
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