- Fe doped copper sulfide nanoparticles for in vivo magnetic resonance imaging and simultaneous photothermal therapy. [Journal Article]
- NNanotechnology 2019 Jun 24
- Multifunctional theranostic agents are widely applied in cancer diagnosis and treatment. These agents can significantly improve therapeutic outcomes and reduce adverse effects in current cancer thera…
Multifunctional theranostic agents are widely applied in cancer diagnosis and treatment. These agents can significantly improve therapeutic outcomes and reduce adverse effects in current cancer therapy. Here, we designed and synthesized iron ions doped copper sulfide nanoparticles with polyvinylpyrollidone (FCS @PVP NPs) for magnetic resonance imaging (MRI) guided photothermal therapy. The biocompatible FCS@PVP NPs with strong near-infrared absorption could be used as the photothermal agent and the magnetic characteristic of Fe3+ ions could be applied for T1-weighted magnetic resonance imaging (MRI). The T1-weighted MRI, high photothermal performance, and the biodistribution of FCS@PVP NPs were investigated in mice after intravenous administration. The data showed that there was high accumulation of FCS@PVP NPs in the tumor site because of the enhanced permeability and retention (EPR) effect. This result also indicated that the tumors in tumor-bearing mice were effectively suppressed after FCS@PVP NPs treatment under 808 nm laser irradiation. More importantly, FCS@PVP NPs show low cytotoxicity and low side effects because of the quick and safe elimination through hepatobiliary/fecal route. This work provided a foundation for the clinical application of FCS@PVP NPs as a promising multifunctional theranostic agent for MRI guided photothermal therapy of cancer.
- Influence of the preparation conditions on the morphology and photocatalytic performance Pt-modified hexaniobate composites. [Journal Article]
- JPJ Phys Condens Matter 2019 Jun 24
- The preparation of lamellar nanostructures through exfoliation of stacked niobates is an interesting approach to the development of photocatalysts for energy conversion and environmental remediation.…
The preparation of lamellar nanostructures through exfoliation of stacked niobates is an interesting approach to the development of photocatalysts for energy conversion and environmental remediation. These materials exhibit a rich surface chemistry and several nanocomposites can be produced through intercalation or impregnation of suitable precursors. In this work, the influence of the physico-chemical preparation conditions on the photocatalytic activity of Pt-hexaniobate nanocomposites was investigated aiming at the establishment of the main factors that control their photoreactivities. Modification of hexaniobate layers were carried out by adsorption and impregnation methods, using [Pt(NH3)4]Cl2 (Pt1) and H2PtCl6 (Pt2), respectively. The addition of platinum precursors (1% wt.) were performed in the presence of the exfoliating agent tert-butylammonium hydroxide, sNb, or after acidic precipitation followed by resuspension in plain water, eNb. All samples were submitted to photoirradiation to reduce the platinum precursors and the effect of a previous thermal treatment was also evaluated. It was observed that H2 evolution from aqueous methanol solutions is more favored on hexaniobate nanosheets (eNb-Pt1 and eNb-Pt2) instead of scrolled layers (sNb-Pt1 and sNb-Pt2), independent on the platinum precursor. Moreover, residual tert-butylammonium can act as hole scavenger and decrease the degradation rates for methanol oxidation in sNb samples. The curled layers observed for sNb samples seem to favor the photodegradation of cationic species, such as methylene blue. Thermal treatment at 500 ºC leads to morphological changes with a decrease of the specific surface area due to restacking of the individual layers along with some curling. As a result, the H2 evolution rates strongly decreases in relation to the non-sintered samples, suggesting that the "soft" photoreduction of the platinum precursors is the best method for preparation of these photocatalysts. The correlations between the preparation conditions and the photocatalytic activity for different photoreactions can allow the development of optimized materials for specific applications.
- Controlled PtIr nanoalloy as electrooxidation platform for methanol reaction and ammonia detection. [Journal Article]
- NNanotechnology 2019 Jun 24
- Herein, a surfactant-free, ethylene glycol-mediated synthesis of PtIr nanoalloys was optimized. In particular, a post-synthesis treatment was identified as the key step in order to determine the nano…
Herein, a surfactant-free, ethylene glycol-mediated synthesis of PtIr nanoalloys was optimized. In particular, a post-synthesis treatment was identified as the key step in order to determine the nanoparticles size and their organization in the nanostructure, depending on the presence of reducing agent and on pressure conditions. After synthesis, the as-obtained nanomaterials were broadly characterized: SEM and TEM images, EDX maps and XRD spectra showed the formation of nanorods with a few nanometers size and similar quantitative compositions of platinum and iridium. Afterward, the electrocatalytic activity towards methanol oxidation reaction (MOR) of the synthesized nanomaterials was tested and the best sample, treated under a hydrogen/nitrogen flow at 10 bar, exhibits a negligible onset potential (0.058 V) and a very high If/Ib ratio (2.5). Moreover, the aforementioned sample was tested as electrochemical sensor for the detection of small traces of ammonia in aqueous solution with a limit of detection (LOD) of 4.88 μM. The sensor was tested also in simulated wastewater coming from the fertilizer industry, showing proper operation and excellent selectivity.
- Ultrathin g-C3N4 with enriched surface carbon vacancies enables highly efficient photocatalytic nitrogen fixation. [Journal Article]
- JCJ Colloid Interface Sci 2019 Jun 15; 553:530-539
- An ultra-thin carbon nitride with loose structure and more carbon defects on the surface was achieved through high-temperature peeling methods. Its composition, morphological characteristics, surface…
An ultra-thin carbon nitride with loose structure and more carbon defects on the surface was achieved through high-temperature peeling methods. Its composition, morphological characteristics, surface defect types and electrochemical properties have been measured. After atomic scale structure control and surface defects construction, the photocatalytic activity of prepared g-C3N4-V for ammonia conversion from dinitrogen can be greatly improved in contrast with bulk g-C3N4. Under visible light irradiation, the defective g-C3N4-V can produce 54 µmol/L NH3 within 100 min without any cocatalyst and sacrificial agent. The relationship between morphology characteristics and activity of defective ultrathin g-C3N4 materials was analyzed in detail. Benefiting from thin layer structure and more surface carbon vacancies, the effective charge separation from both bulk and surface can be achieved. Notably, the engineered carbon vacancies greatly facilitate the adsorption and activation of dinitrogen molecule, extremely improving the nitrogen fixation activity for the defective ultrathin g-C3N4-V materials. This work affords novel insights into the design of photocatalyst with defective ultrathin structure towards nitrogen fixation.
- Object's symmetry alters spatial perspective-taking processes. [Journal Article]
- CCognition 2019 Jun 21; 191:103987
- Spatial perspective-taking (SPT) refers to one's ability to identify or understand the location of a target relative to another viewpoint, which could be specified by a human-like agent or a referenc…
Spatial perspective-taking (SPT) refers to one's ability to identify or understand the location of a target relative to another viewpoint, which could be specified by a human-like agent or a reference object (e.g., a chair). Previous studies have shown that SPT is characterized by different processes depending on whether one is required to make a left/right or front/behind judgment. An object's shape, however, may also account for the different processes, as previous studies typically used reference objects that were left-right symmetrical and front-back asymmetrical (e.g., human figures, dolls, or chairs), thus confounding effects of judgment direction and effects of objects' shape. To address this issue, we manipulated objects' shape (symmetrical or asymmetrical about front-back or left-right) independently of judgment direction (i.e., left/right or front/behind) and compared participants' efficacy of such judgments. Our results showed that egocentric transformations were used more frequently for judgments orthogonal to the object's symmetry plane than for judgments orthogonal to the object's asymmetry plane, whereas the inverse was true for mental scanning. Notably, these tendencies were observed regardless of whether the judgment was about left/right or front/behind. Nonetheless, egocentric transformations were found to be more difficult to apply to the front/behind judgments than to the left/right judgments. We also found that this difficulty was alleviated by rich imagination. Furthermore, we found that participants tended to erroneously perceive a front-back symmetrical human-like object as facing them, even when it was actually facing away from them (facing bias). This in turn forced the participants to conduct unnecessary egocentric transformations. Overall, our findings demonstrated that objects' symmetry dramatically influenced SPT processes.
- Comparative study of persulfate oxidants promoted photocatalytic fuel cell performance: Simultaneous dye removal and electricity generation. [Journal Article]
- CChemosphere 2019 Jun 18; 234:658-667
- Introducing peroxymonosulfate (PMS) and peroxydisulfate (PDS) into the photocatalytic fuel cell (PFC) system were investigated by comparing the Reactive Brilliant Blue (KN-R) degradation and synchron…
Introducing peroxymonosulfate (PMS) and peroxydisulfate (PDS) into the photocatalytic fuel cell (PFC) system were investigated by comparing the Reactive Brilliant Blue (KN-R) degradation and synchronous electricity production. The two persulfates (PS) themselves are strong oxidant, and could be activated and as electron sacrificial agent in the PFCs, facilitating the photoelectrocatalysis and expanding redox to the entire cell space. Hence, the two established PFC/PS systems manifested prominent cell performances, enhancing the KN-R decomposition and electric power production relative to the virgin PFC. Thereinto, the KN-R removal rate of PFC/PMS was faster than that of PFC/PDS, but an opposite trend appeared in the electricity generation. Besides, the cell performances of the two cooperative systems were evaluated at different operation conditions, including PS dosage, solution pH, and irradiation strength. Moreover, the dye elimination principle was explored by radicals scavenging experiment, and the consequence revealed that hydroxyl radical (HO•), sulfate radical (SO4•-) and singlet oxygen were chief active species in the PFC/PMS, and HO•, SO4•- and superoxide anion played the key roles in the PFC/PDS. Furthermore, the calculated economic indicator demonstrated that the economy of the two synergistic processes were greater than that of UV/PS and solo PFC, and the PFC/PDS was more cost-effective than PFC/PMS.
- VAMP (Voting Agent Model of Preferences): A computational model of individual multi-attribute choice. [Journal Article]
- CCognition 2019 Jun 21; 192:103971
- This paper proposes an original account of decision anomalies and a computational alternative to existing dynamic models of multi-attribute choice. To date, most models attempting to account for the …
This paper proposes an original account of decision anomalies and a computational alternative to existing dynamic models of multi-attribute choice. To date, most models attempting to account for the "Big Three" decision anomalies (similarity, attraction, and compromise effects) are variants of evidence accumulation models, or rational Bayesian analysis. This paper provides an existence proof of a new approach in the form of a multi-agent system based on the principles of voting geometry. Assuming there are a number of neural systems (agents) within an individual's brain, the Big Three decision anomalies can arise as a natural consequence of aggregating preferences across these agents. We operationalize these principles in VAMP, (Voting Agent Model of Preferences), and compare its performance to existing computational models as well as to empirical data. This provides a fundamentally different lens for understanding decision anomalies in multi-attribute choice.
- Protective effects of melatonin on sepsis-induced liver injury and dysregulation of gluconeogenesis in rats through activating SIRT1/STAT3 pathway. [Journal Article]
- BPBiomed Pharmacother 2019 Jun 21; 117:109150
- Sepsis, a life-threatening disease with high morbidity and mortality in critically ill patients, usually leads to serious complications including liver damage and dysregulated metabolic homoeostasis.…
Sepsis, a life-threatening disease with high morbidity and mortality in critically ill patients, usually leads to serious complications including liver damage and dysregulated metabolic homoeostasis. The aim of this study was to evaluate the therapeutic potential of melatonin in rats with caecal ligation and puncture (CLP)-induced sepsis, which mimics critical infections in humans and explore the underlying molecular mechanisms. Male Sprague-Dawley rats received CLP surgery under anaesthesia to induce polymicrobial sepsis. Melatonin (20 mg/kg) was intraperitoneally (i.p.) injected every 12 h for 7 days after CLP, with or without intraperitoneal injection of the SIRT1 inhibitor EX527 (5 mg/kg). Markers of glucose metabolism, inflammation, liver function and associated signaling pathway were measured. Septic rats exhibited marked inhibition of the hepatic SIRT1/STAT3 pathway, along with increased blood glucose levels and hepatic gluconeogenesis. Melatonin administration efficiently attenuated liver dysfunction and glucose metabolism disorders by promoting hepatic SIRT1 expression and STAT3 phosphorylation. Furthermore, inhibition of SIRT1 by EX527 significantly diminished the protective effects of melatonin on sepsis induced liver injury, hyperglycaemia and STAT3 inactivation. These results emphasize that melatonin is a potential therapeutic agent for sepsis-associated liver injury and glucose metabolism disorders, possibly acting by targeting SIRT1-mediated STAT3 activation in the liver.
- In-situ growth of NiWO4 saw-blade-like nanostructures and their application in photo-electrochemical (PEC) immunosensor system designed for the detection of neuron-specific enolase. [Journal Article]
- BBBiosens Bioelectron 2019 Jun 08; 141:111331
- This study describes the construction of highly-sensitive photo-electrochemical (PEC) immunosensor for the detection of neuron-specific enolase (NSE). The biosensing platform is comprised of photo-ac…
This study describes the construction of highly-sensitive photo-electrochemical (PEC) immunosensor for the detection of neuron-specific enolase (NSE). The biosensing platform is comprised of photo-active NiWO4 nanostructures, in-situ-grown over a conductive substrate (indium tin oxide) using a low-temperature template-based co-precipitation approach. The discussed approach enables the formation of discrete, yet morphologically-analogous, nanostructures with complete coverage (pinhole-free) of the electrode surface. The in-situ-grown nanostructure possess dense population with sharp saw-blade like morphological features that can support substantial immobilisation of anti-NSE agent. The constructed platform demonstrated excellent photo-catalytic activity towards uric acid (UA) which served as the base for the Electrochemical -mechanism (EC) based PEC inhibition sensing. The detection of NSE, relied on its obstruction in analytical signal observed for the photo-oxidation of UA after binding to the electrode surface via protein-antibody interaction. The constructed PEC immunosensor exhibits signal sensitivity up to 0.12 ng mL-1 of NSE with excellent signal reproducibility and electrode replicability. Moreover, the constructed platform was successfully used for NSE determination in human serum samples.
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- Visual and verbal learning and memory in cystinosis. [Journal Article]
- BCBrain Cogn 2019 Jun 21; 135:103578
- Cystinosis is a rare genetic lysosomal storage disorder characterized by the accumulation of cystine in lysosomes. Many organ systems are vulnerable to this cystine accumulation including the CNS. A …
Cystinosis is a rare genetic lysosomal storage disorder characterized by the accumulation of cystine in lysosomes. Many organ systems are vulnerable to this cystine accumulation including the CNS. A past study demonstrated that children with cystinosis have deficits in visual learning and memory while their verbal learning and memory and global intellectual function are spared (Spilkin, Ballantyne, & Trauner, 2009). However, no related study has been performed to assess the dissociation between visual and verbal learning and memory in adults with cystinosis who have had the benefit of longterm treatment with the cystine-depleting agent, cysteamine. In this study we assessed visual and verbal learning and memory in 15 adults with cystinosis, with a mean age of 30.2 years. The results indicate that adults with cystinosis have no significant deficits in either verbal or visual learning and memory. However, the individuals did perform better on the verbal assessment. The results suggest that if early and continued treatment is given to individuals with cystinosis there is a relative sparing of visual learning and memory that might have otherwise declined. This emphasizes the essential nature of the proper clinical management of cystinosis.