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An increasing number of cases of cerebral embolism caused by cardiac myxoma have been reported. However, cerebral infarction caused by different types of emboli obstructing different vascular regions within a short period of time has not been reported. This is the first report to histologically confirm cerebral infarctions independently caused by thrombus and myxomatous embolus in a patient with cardiac myxoma within a period of 23 days. The first cerebral infarction was due to embolization of thrombus to the right middle cerebral artery, whereas the second was due to embolization of tissue from a mucinous tumor to the left middle cerebral artery. Both cerebral infarctions underwent mechanical thrombectomy, but unfortunately, we ultimately failed to save the patient's life. Therefore, further attention should be paid to the surgical resection and treatment of cardiac myxoma.
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The aim of the study was to assess the association between lipoprotein(a) [Lp(a)] concentration and incident type 2 diabetes. A meta-analysis of qualified studies on the relationship of low levels of Lp(a) concentration with incident type 2 diabetes was conducted. PubMed and Cochrane libraries were searched for randomized controlled trials containing data on events. Seven randomized trials with 227178 subjects were included in this analysis. We found an inverse association of the levels of Lp(a) concentration with risk of type 2 diabetes with approximately 37% lower relative risk in the group with the highest concentration compared with group with the lowest concentration. The current available evidence from prospective studies suggests that there is an inverse association between the levels of Lp(a) concentration and risk of type 2 diabetes, with a higher risk of type 2 diabetes at low levels of Lp(a) concentration. Therefore, we believe that the low levels of Lp(a) concentration is an independent predictor of incident type 2 diabetes.
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Diabetes Mellitus Tipo 2 , Lipoproteína(a) , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/epidemiologia , Humanos , Lipoproteína(a)/sangue , Incidência , Fatores de Risco , Ensaios Clínicos Controlados Aleatórios como Assunto , PrognósticoRESUMO
AIM: Bempedoic acid has shown noteworthy progress in the prevention and management of atherosclerotic cardiovascular disease (ASCVD) in recent years. However, there has been a lack of high-quality evidence regarding the risk reduction of clinical events with bempedoic acid. Therefore, the aim of this article is to conduct a comprehensive evaluation of the impact of bempedoic acid on the incidence of cardiovascular events. METHODS: A systematic review and meta-analysis of randomized controlled trials pertaining to bempedoic acid was carried out. We conducted a systematic search across the Pubmed, Embase, and Cochrane Central Register of Controlled Trials databases to identify relevant studies published from inception to 23 April 2023. A total of four trials comparing the clinical benefit achieved with bempedoic acid versus placebo were included. RESULTS: Our analysis comprised four trials that encompassed a total of 17,323 patients. In comparison to the placebo, bempedoic acid showed a significant reduction in the risk of major adverse cardiovascular events (MACE) [relative risk (RR), 0.86, 95% confidence interval (CI) 0.87-0.94]. Additionally, bempedoic acid substantially lowered the occurrence of fatal or nonfatal myocardial infarction (RR 0.76, 95% CI 0.66-0.89), hospitalization for unstable angina (RR 0.70, 95% CI 0.55-0.89), and coronary revascularization (RR 0.82, 95% CI 0.73-0.92). There was also a similar reduction in MACE in patients on the maximally tolerated statin therapy. CONCLUSION: Bempedoic acid may reduce the risk of cardiovascular events regardless of whether the patient is taking stains or not. REGISTRATION: PROSPERO registration number CRD42023422932.
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Doenças Cardiovasculares , Inibidores de Hidroximetilglutaril-CoA Redutases , Infarto do Miocárdio , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Infarto do Miocárdio/tratamento farmacológico , Infarto do Miocárdio/epidemiologia , Infarto do Miocárdio/prevenção & controle , Ácidos Dicarboxílicos/uso terapêutico , Ácidos Graxos/efeitos adversos , Doenças Cardiovasculares/tratamento farmacológicoRESUMO
Mineralocorticoid receptor antagonists (MRAs) are a cornerstone drug class for heart failure therapy. Several clinical studies have demonstrated its role in heart failure therapy. However, due to the recommendation of sodium-glucose cotransporter-2 (SGLT-2) inhibitors for the treatment of heart failure, there is a lack of sufficient evidence regarding whether MRAs can continue to play a cornerstone role in heart failure treatment. A meta-analysis was performed on subgroups of the DAPA-HF and EMPEROR-Reduced trials. Using trial-level data, we performed a meta-analysis to assess the effects of SGLT-2 inhibitors and MRAs on various clinical endpoints of heart failure. The incidence of cardiovascular-related death or heart failure hospitalization was the primary outcome. In addition, we assessed cardiovascular death, all-cause death, heart failure hospitalization, renal outcomes, and hyperkalemia. This study has already been registered with PROSPERO, CRD42022385023. Compared with SGLT-2 inhibitor monotherapy, combined treatment did not demonstrate more significant advantages in terms of heart failure or cardiovascular death (RR = 1.00; 95% CI: 0.78-1.28), cardiovascular death (RR = 0.96; 95% CI: 0.61-1.52), heart failure hospitalization (RR = 0.92; 95% CI: 0.79-1.07), all-cause death (RR = 1.00; 95% CI: 0.63-1.59) and composite kidney endpoint (RR = 0.85; 95% CI: 0.49-1.46). Moreover, in comparison to SGLT-2 inhibitors, combined therapy increased the risk of moderate-severe hyperkalemia (blood potassium > 6.0 mmol/l) (RR = 4.13; 95% CI: 2.23-7.65). In patients with HFrEF who have started MRAs treatment, the addition of an SGLT-2 inhibitor provides significant clinical benefit. However, the addition of MRAs to SGLT-2 inhibitors to treat heart failure is not essential.
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Incorporation of ultrathin nanosheets with dopants/defects shows great potential to enable metal (oxy)-hydroxide electrocatalysts with enhanced oxygen evolution reaction (OER) performance via the regulation of atomic structure and bonding arrangements. However, it remains challenging in synthesis especially for such dual control and at large scale. In this study, we present a stepwise chemical oxidation route, involving phase transition and reconstruction processes, to access ultrathin CoOOH nanosheets with a thickness of ca. 4 nm and abundant oxygen vacancies. Other transition metals were also doped into CoOOH nanosheets through this strategy. Among them, the optimized FeCoOOH nanosheets demonstrated an efficient OER activity with overpotential as low as 252 mV (current density: 10 mA cm-2) and excellent stability. A high and stable solar-to-hydrogen efficiency of 10.5% was acquired when FeCoOOH nanosheets were used as the anode in a constructed water splitting device driven by solar energy. This study offers a noble and facile strategy for potentially scalable preparation of atom-modulated ultrathin metal (oxy)-hydroxide nanosheets, and also demonstrates the OER applications.
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Water oxidation is a vital step in both natural and artificial photosynthetic processes. However, the effect of second coordination sphere for efficient oxygen evolution electrocatalysts has rarely been studied, becoming a bottleneck in many energy-related issues. In this article, the cobalt phosphonate (NH3C6H4NH3)Co2(hedpH)2·H2O (Co-PDA) displayed decent electrocatalytic water oxidation activity in 50 mM PBS solution (pH 7.0), comparable to the activity of state-of-the-art IrO2. Moreover, it exhibited a 160 mV lower onset potential and 6 times higher TOF than those of the counterpart, (NH4)2Co2(hedpH)2 (Co-NH4+), which existed with the same Co active center, while surrounded by different ligands. The related mechanistic studydemonstrates that the ligand in Co-PDA would benefit the proton-coupled electron transfer (PCET) processes and the formation of high valence state Co(iv).
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A high-quality dielectric layer is essential for organic thin-film transistors (OTFTs) operated at a low-power consumption level. In this study, a facile improved technique for the synthesis of solution-processed silica is proposed. By optimizing the synthesis and processing technique fewer pores were found on the surface of the film, particularly no large holes were observable after improving the annealing process, and the improved solution-gelation (sol-gel) SiOx dielectric achieved a higher breakdown strength (1.6 MV/cm) and lower leakage current density (10-8 A/cm2 at 1.5 MV/cm). Consequently, a pentacene based OTFT with a high field effect mobility (~1.8 cm2/Vs), a low threshold voltage (-1.7 V), a steeper subthreshold slope (~0.4 V/dec) and a relatively high on/off ratio (~105) was fabricated by applying a hybrid gate insulator which consisted of improved sol-gel SiOx and polyvinyl phenol (PVP). This could be ascribed to both the high k of SiOx and the smoother, hydrophobic dielectric surface with low trap density, which was proved by atomic force microscopy (AFM) and a water contact angle test, respectively. Additionally, we systematically studied and evaluated the stability of devices in the compressed state. The devices based on dielectric fabricated by conventional sol-gel processes were more susceptible to the curvature. While the improved device presented an excellent mechanic strength, it could still function at the higher bending compression without a significant degradation in performance. Thus, this solution-process technology provides an effective approach to fabricate high-quality dielectric and offers great potential for low-cost, fast and portable organic electronic applications.
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This work reports a novel dual-phase glass containing Tm:NaYbF4 upconverting nanocrystals (UCNCs) and CsPbBr3 perovskite nanocrystals (PNCs). The advantages of this kind of nanocomposite are that it provides a solid inorganic glass host for the in situ co-growth of UCNCs and PNCs, and protects PNCs against decomposition affected by the external environment. Tm:NaYbF4 NC-sensitized stable CsPbBr3 PNCs photon UC emission in PNCs is achieved under the irradiation of a 980 nm near-infrared (NIR) laser, and the mechanism is evidenced to be radiative energy transfer (ET) from Tm3+: 1G4 state to PNCs rather than nonradiative Förster resonance ET. Consequently, the decay lifetime of exciton recombination is remarkably lengthened from intrinsic nanoseconds to milliseconds since carriers in PNCs are fed from the long-lifetime Tm3+ intermediate state. Under the simultaneous excitation of the ultraviolet (UV) light and NIR laser, dual-modal photon UC and downshifting (DS) emissions from ultra-stable CsPbBr3 PNCs in the glass are observed, and the combined UC/DS emitting color can be easily altered by modifying the pumping light power. In addition, UC exciton recombination and Tm3+ 4f-4f transitions are found to be highly temperature sensitive. All these unique emissive features enable the practical applications of the developed dual-phase glass in advanced anti-counterfeit and accurate temperature detection.
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Polymer-ceramic dielectric composites have been of great interest because they combine the processability of polymers with the desired dielectric properties of the ceramics. We fabricated a low voltage-operated flexible organic field-effect transistor (OFET) based on crosslinked poly (4-vinyl phenol) (PVP) polymer blended with novel ceramic calcium titanate nanoparticles (CaTiO3 NPs) as gate dielectric. To reduce interface roughness caused by nanoparticles, it was further coated with a very thin PVP film. The resulting OFET exhibited much lower operated voltage (reducing from -10.5 V to -2.9 V), a relatively steeper threshold slope (~0.8 V/dec) than those containing a pure PVP dielectric. This is ascribed to the high capacitance of the CaTiO3 NP-filled PVP insulator, and its smoother and hydrophobic dielectric surface proved by atomic force microscopy (AFM) and a water contact angle test. We also evaluated the transistor properties in a compressed state. The corresponding device had no significant degradation in performance when bending at various diameters. In particular, it operated well continuously for 120 hours during a constant bending stress. We believe that this technology will be instrumental in the development of future flexible and printed electronic applications.
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The development of high-performance acetone gas sensor is of great significance for environmental protection and personal safety. SnO2 has been intensively applied in chemical sensing areas, because of its low cost, high mobility of electrons, and good chemical stability. Herein, we incorporated nitrogen atoms into the SnO2 nanostructure by simple solvothermal and subsequent calcination to improve gas sensing property for acetone. The crystallization, morphology, element composition, and microstructure of as-prepared products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Electron paramagnetic resonance (EPR), Raman spectroscopy, UVâ»visible diffuse reflectance spectroscopy (UVâ»vis DRS), and the Brunauerâ»Emmettâ»Teller (BET) method. It has been found that N-incorporating resulted in decreased crystallite size, reduced band-gap width, increased surface oxygen vacancies, enlarged surface area, and narrowed pore size distribution. When evaluated as gas sensor, nitrogen-incorporated SnO2 nanostructure exhibited excellent sensitivity for acetone gas at the optimal operating temperature of 300 °C with high sensor response (Rair/Rgas - 1 = 357) and low limit of detection (7 ppb). The nitrogen-incorporated SnO2 gas sensor shows a good selectivity to acetone in the interfering gases of benzene, toluene, ethylbenzene, hydrogen, and methane. Furthermore, the possible gas-sensing mechanism of N-incorporated SnO2 toward acetone has been carefully discussed.
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Incorporation of new functional components into a three-dimensional graphene (3DG) framework improves the performance of supercapacitors based on 3DG as electrodes by tailoring the framework's structure and properties. In this work, graphene quantum dots (GQDs) were incorporated into 3DG via one-step hydrothermal treatment of GQDs and graphene oxide (GO). By simply adjusting the GQDs/GO feeding ratio by weight, various GQDs/3DG composites were formed. The maximum feeding ratio was 80%, and the prepared composites possessed saturated GQDs loading on the 3DG framework, whereas composites obtained with a GQDs/GO feeding ratio of 40% as electrodes exhibited optimal specific capacitance of 242 F·g-1 for supercapacitors, an increase of 22% compared with that of pure 3DG electrodes (198 F·g-1). This improved performance was mainly due to better electrical conductivity and larger surface area for GQDs/3DG composites with moderate GQDs content. The fabricated GQDs/3DG composites as electrodes for supercapacitors revealed high electrochemical stability. Their capacitance kept 93% of the initial value after 10,000 charge-discharge cycles.
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Graphene quantum dots (GQDs) have fascinating photoluminescence (PL) properties with promising applications in bioimaging, fluorescent sensing and the photoelectrics field. In this work, PL properties of GQDs obtained from different carbonaceous precursors including carbon fibers, graphite powder, graphene oxide (GO) and reduced graphene oxide (RGO) were regulated via a simple hydrothermal reduction. Upon hydrothermal treatment, the fluorescent peaks of the original GQDs were blue-shifted to 440 nm and their PL intensities were enhanced by about 2 times. Furthermore, the full widths at half maxima (FWHM) of the fluorescent peaks were narrowed. The improved PL properties of the GQDs were mainly attributed to the change of oxygenated groups on the GQDs surface, with most hydroxyl and epoxy groups of the GQDs removed, while carboxyl groups were largely intact. Different from chemical modification methods, the improvement of PL properties of GQDs by a hydrothermal method revealed the effect of different oxygenated groups on the GQDs surface on their PL properties, helping to clarify the PL mechanism of GQDs.
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The excited-state proton transfer (ESPT) via proton transfer wires in green fluorescent protein (GFP) plays an important role on the spectroscopic of GFP. In this work, we use the proton transfer wires and the chromophore complex to simulate the tautomer structures of neutral state and the intermediate state in wt-GFP. And we employ the time-dependent density functional theory combined with the sum-over-states method to calculate the one- and two-photon absorption properties of these complexes in GFP. We obtain the large stokes shift from 383 nm to 500 nm in GFP when simulating the ESPT process by these isomerous H-bonding complexes. We find that the TPA spectrum of the H-bonding complex of the intermediate state agrees more with experimental measurement than that of the H-bonding complex of the neutral state. The TPA spectrum of GFP might be mainly dominated by the structure which is similar to the H-bonding complex of intermediate state. Further, we simulate another kind of complex which possess short-strong hydrogen bonds in proton transfer wires, and find that TPA properties of these complexes are much stronger than that of the complexes with the long distance proton wires from GFP.
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Proteínas de Fluorescência Verde/química , Prótons , Teoria Quântica , AbsorçãoRESUMO
This work has initiated an investigation on the electrochemical behaviors and the structure changes of the composite electrode 0.3Li(2)MnO(3)·0.7LiMn(1/3)Ni(1/3)Co(1/3)O(2) when charged with different cut-off voltages. It is found that the charge cut-off voltages could not only affect the capacity property and coulombic efficiency, but also alter the electrode kinetics of the composite. As a consequence, the electrochemical activation of the composite electrode is highly dependent on the charge cut-off voltages: when the charge cut-off voltage is higher than 4.5 V, the inert component Li(2)MnO(3) in the composite electrode is completely activated. At the meanwhile, there occurred an irreversible oxygen loss during the initial charge process, which yielded a hollow sphere in the electrode. Regardless of charge voltages, Mn ions in the composite electrode were presented in an oxidation state of +4, while Co(2+) ions were detected at the surface of the electrode when cycled at low voltages. Ni ions in the composite could react with organic or inorganic species and then cover the surface of the cycled electrode.
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Chemically tailoring microstructures for an optimum red luminescence is a subject at the forefront of many disciplines, which still remains a challenge due to a poor knowledge about the roles of defects in structures. In this work, GdVO(4) :Eu(3+) nano/microstructures of different morphologies, including tomato-like, cookie-circle-like, and ellipsoidal-like nanoparticles, and microspheroids were synthesized via a simple hydrothermal route using trisodium citrate as a capping agent. During the growth processes, the types of vanadyl ions were adjusted by varying pH value to control the morphologies and nano/microstructures with the help of trisodium citrate. The possible mechanisms for the growth processes into diverse morphologies are presented. Further, a systematic study on defect characteristics pertinent to these diverse morphologies has been explored to achieve an optimum red luminescence. The ability is clearly shown to generate different nano/microstructures of diverse morphologies and varied defect concentrations, which provides a great opportunity for morphological control in tailoring the red luminescence property for many technological applications.
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A series of Pr(1-x)Ca(x)CoO(3) samples were prepared using a novel molten salt reaction that is convenient to obtain single phases avoiding aggregates compared to conventional solid state reactions. The formation reaction was monitored by X-ray diffraction combined with thermal analysis, and all samples were characterized by X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, and alternating current impedance. It is demonstrated that all Pr(1-x)Ca(x)CoO(3) samples crystallized in a pure orthorhombic perovskite structure. By increasing the doping level, the symmetry of the orthorhombic structure was enhanced, and is followed by an increase in the population of Co(3+) in the intermediate spin state. All samples exhibited typical semiconducting behavior, showing conductivities highly dependent on the Ca(2+) doping. The conduction for x = 0 shows a simple thermal activated process, which changed into a Mott's variable range hopping mechanism for x > 0. By increasing the Ca(2+) doping level, the relevant activation energy is decreased, while the density of the localized electronic state is increased.
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Porous SnIn(4)S(8) microspheres were initially synthesized through a facile solvothermal approach and were investigated as visible-light driven photocatalysts for dyes degradation in polluted water. The photocatalysts were characterized by XRD, SEM, TEM, N(2) adsorption-desorption, and UV-vis diffuse reflectance techniques. Results demonstrated that the as-synthesized SnIn(4)S(8) was of a new tetragonal polymorph, showing a band-gap of 2.5 eV, a specific surface area of 197 m(2) g(-1), and an accessible porous structure as well. The photocatalytic activity of the porous SnIn(4)S(8) was evaluated by decomposition of several typical organic dyes including methyl orange, rhodamine B, and methylene blue in aqueous solution under visible light irradiation. It is demonstrated that porous SnIn(4)S(8) was highly photoactive and stable for dyes degradation, showing photocatalytic activity much higher than binary constituent sulfides like In(2)S(3), SnS(2), or even ternary chalcogenide ZnIn(2)S(4) photocatalyst. The excellent photocatalytic performance of porous SnIn(4)S(8) is the consequence of its high surface area, well-defined porous texture, and large amount of hydroxyl radicals.
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Corantes/química , Índio/química , Luz , Microesferas , Estanho/química , Catálise , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Fotoquímica , Espectrofotometria Ultravioleta , Difração de Raios XRESUMO
In this work, preparation of cereal-like architectures Y V O(4) and Y V O(4):Ln(3 + ) (Ln = Eu, Sm, Dy, Tb) was initiated using a hydrothermal method. During the formation reaction, Na(3)C(6)H(5)O(7).2H(2)O was used to effectively adjust the concentration of Y(3 + ) species necessary for cereal-like architectures. Phase structure, surface chemistry, morphology, and photoluminescence were characterized by x-ray powder diffraction, Fourier transformed infrared spectra, scanning electron microscopy, transmission electron microscopy, and photoluminescence spectra. All samples crystallize in a tetragonal zircon structure, stably showing a homogeneous cereal-like morphology. This special morphology was constructed by self-assembly of tiny primary particles with a dimension of 31-32 nm. With increasing atomic number of Ln(3 + ), the lattice dimension of the cereal architectures became monotonously enlarged. This cereal-like architecture is proved unique in significantly improving the quantum efficiencies: the internal quantum efficiencies of (5)D(0) for Ln = Eu and (4)F(9/2) for Ln = Dy were 14.6% and 11.4%, respectively, which are all superior over those of the counterparts of nanoparticles reported in the literature. The average lifetime of the (5)D(0) level for Ln = Eu was calculated to be 98 micros, which is longer than that of 50 micros of the (4)F(9/2) level for Ln = Dy. The strong photoluminescence might be the consequence of the effective energy transfer due to the greatly reduced defect centers from this special self-assembly structure.