RESUMEN

The downsizing of microscale energy storage devices plays a crucial role in powering modern emerging devices. Therefore, the scientific focus on developing high-performance microdevices, balancing energy density and power density, becomes essential. In this context, we explore an advanced Microplotter technique to fabricate hybrid planar Zn-ion microcapacitors (ZIMCs) that exhibit dual charge storage characteristics, with an electrical double layer capacitor type activated carbon anode and a battery type VO2 (B) cathode, aiming to achieve energy density surpassing supercapacitors and power density exceeding batteries. Effective loading of VO2 (B) cathode electrode materials combined with activated carbon anode onto confined planar microelectrodes not only provides reversible Zn2+ storage performance but also mitigates dendrite formation. This not only results in superior charge storage performance, including areal energies of 2.34 µWh/cm2 (at 74.76 µW/cm2) and 0.94 µWh/cm2 (at 753.12 µW/cm2), exceeding performance of zinc nanoparticle anode and activated carbon cathode based ZIMCs, but also ensures stable capacity retention of 87% even after 1000 cycles and free from any unwanted dendrites. Consequently, this approach is directed toward the development of high-performance ZIMCs by exploring high-capacity materials for efficient utilization on microelectrodes and achieving maximum possible capacities within the constraints of the limited device footprint.

RESUMEN

An unprecedented intermolecular [4 + 2] cycloaddition of benzocyclobutylamines with α-substituted vinylketones, enabled by photoredox catalysis, has been developed. The current method enables facile access to highly functionalized cyclohexylamine derivatives that were otherwise inaccessible, in moderate to good yields with excellent diastereoselectivities. This protocol has some excellent features, such as full atom economy, good functional-group compatibility, mild reaction conditions, and an overall redox-neutral process. Additionally, an asymmetric version of this cycloaddition was preliminarily investigated via the incorporation of a chiral phosphoric acid (CPA), and moderate to good enantioselectivity could be effectively realized with excellent diastereoselectivity. Synthetic applications were demonstrated via a scale-up experiment and elaborations to access amino alcohol and cyclobutene derivatives. Based on the results of control experiments, a reasonable reaction mechanism was proposed to elucidate the reaction pathway.

RESUMEN

Solar power represents an abundant and readily available source of renewable energy. However, its intermittent nature necessitates external energy storage solutions, which can often be expensive, bulky, and associated with energy conversion losses. This study introduces the concept of a photo-accelerated battery that seamlessly integrates energy harvesting and storage functions within a single device. In this research, a novel approach for crafting photocathodes is presented using hydrogenated vanadium pentoxide (H:V2O5) nanofibers. This method enhances optical activity, electronic conductivity, and ion diffusion rates within photo-accelerated Li-ion batteries. This study findings reveal that H:V2O5 exhibits notable improvements in specific capacity under both dark and illuminated conditions. Furthermore, it demonstrates enhanced diffusion kinetics and charge storage performance when exposed to light, as compared to pristine counterparts. This strategy of defect engineering holds great promise for the development of high-performance photocathodes in future energy storage applications.

RESUMEN

Cutting of soft materials is a complex problem, which is still not well understood at the fundamental level, especially for soft materials. The cutting process we consider is slicing, which starts with indentation, followed by sliding of a knife on the material to be cut. Here, we describe cutting experiments on PDMS elastomers with three different moduli. Our experiments reveal typical stages of this cutting process, starting with indentation and ending at steady state cutting. The process starts with a pre-cutting phase in which the blade does not slip grossly relative to the solid to be cut, and deformation is mostly elastic. Slip of the blade initiates suddenly and is often accompanied by initiation of cutting. Cutting is relatively smooth in the next stage, which requires a continuous increase in shear force. For soft PDMS, this smooth cutting stage is followed by one in which folds or creases form on the cutting surface. The corresponding shear force response is no longer smooth as "steady" sliding occurs in a stick-slip fashion with oscillatory forces. The average shear force reaches a plateau and no longer increases with shear displacement. Experimental observations of the various cutting stages are interpreted quantitatively.

RESUMEN

Given the rapid progress and widespread adoption of advanced energy storage devices, there has been a growing interest in aqueous capacitors that offer non-flammable properties and high safety standards. Consequently, extensive research efforts have been dedicated to investigating zinc anodes and low-cost carbonaceous cathode materials. Despite these efforts, the development of high-performance zinc-ion capacitors (ZICs) still faces challenges, such as limited cycling stability and low energy densities. In this study, we present a novel approach to address these challenges. We introduce a three-dimensional (3D) conductive porous carbon framework cathode combined with zinc anode cells, which exhibit exceptional stability and durability in ZICs. Our experimental results reveal remarkable cycling performance, with a capacity retention of approximately 97.3% and a coulombic efficiency of nearly 100% even after 10,000 charge-discharge cycles. These findings represent significant progress in improving the performance of ZICs.

RESUMEN

The development of photo-enhanced lithium-ion batteries, where exposing the electrodes to light results in higher capacities, higher rate performance or self-charging, has recently gained substantial traction. The challenge in these devices lies in the realisation of photo-electrodes with good optical and electrochemical properties. Herein, we propose copper-hexahydroxybenzene as the active photo-electrode material which both harvests light and stores energy. This material was mixed with reduced graphene oxide as a conductive additive and charge transfer medium to create photo-active electrodes. Under illumination, these electrodes show improved charge storage kinetics resulting in the photo-accelerated charging and discharging performance (i.e. specific capacities improvement from 107 mA h g-1 to 126 mA h g-1 at 200 mA g-1 and 79 mA h g-1 to 97 mA h g-1 at 2000 mA g-1 under 1 sun illumination as compared to dark).

RESUMEN

The development of devices with dual solar energy-harvesting and storage functionalities has recently gained significant traction for off-grid power supply. In their most compact embodiment, these devices rely on the same electrode to harvest and store energy; however, in this approach, the development of energy-efficient photoelectrodes with intrinsic characteristics of good optical and electrochemical activities remains challenging. Here, we propose photoelectrodes with a porous carbon coated on a zinc oxide-cadmium sulfide heterostructure as an energy-efficient photocathode for photo-accelerated zinc ion capacitors (Photo-ZICs). The Photo-ZICs harvest light energy and store charge simultaneously, resulting in efficient charge storage performance under illumination compared to dark conditions (∼99% capacity enhancement at 500 mA g-1 under illumination compared to dark conditions). The light absorption ability and charge separation efficiency achieved by the photocathodes meet the requirements for photo-ZIC applications. Moreover, Photo-ZICs display stable charge storage capacities over long-term cycling, that is, ∼1% capacity loss after 10,000 cycles.

RESUMEN

Herein, a novel strategy for the catalytic asymmetric synthesis of enantioenriched 3-cis- and 3-trans-substituted prolines has been successfully established via an unprecedented cascade radical addition/cyclization enabled by synergistic photoredox/Brønsted acid catalysis and subsequent base-assisted epimerization. The current protocol provides a unique de novo access to all four stereoisomers of 3-substituted prolines which are not readily achieved via currently established methods. This methodology could be further extended to the asymmetric synthesis of the full complement of stereoisomers of 3-substituted pipecolinic acids.

RESUMEN

Medical multiobjective image segmentation aims to group pixels to form multiple regions based on the different properties of the medical images. Segmenting the 3D cardiovascular magnetic resonance (CMR) images is still a challenging task owing to several reasons, including individual differences in heart shapes, varying signal intensities, and differences in data signal-to-noise ratios. This paper proposes a novel and efficient U-Net-based 3D sparse convolutional network named SparseVoxNet. In this network, there are direct connections between any two layers with the same feature-map size, and the number of connections is reduced. Therefore, the SparseVoxNet can effectively cope with the optimization problem of gradients vanishing when training a 3D deep neural network model on small sample data by significantly decreasing the network depth, and achieveing better feature representation using a spatial self-attention mechanism finally. The proposed method in this paper has been thoroughly evaluated on the HVSMR 2016 dataset. Compared with other methods, the method achieves better performance.

Asunto(s)

RESUMEN

There are major disparities in oral health between Aboriginal and Torres Strait Islander and non-Aboriginal and Torres Strait Islander people. The New South Wales (NSW) Aboriginal Oral Health Plan 2014-2020 was developed to improve the oral health of Aboriginal people. This scoping review describes programs that have been undertaken to implement the NSW Aboriginal Oral Health Plan 2014-2020. The methodology by Arksey and O'Malley was used to guide this review. Academic and grey literature were searched using a structured Medline, Lowitja and advanced Google searches. Articles were included if they aligned with the strategic directions of the Plan. Key information, including the aims of the study, methodology and results were recorded in a template on Microsoft Excel software. A total of 31 articles were included in this review. This included 25 articles from the academic literature and six initiatives from the grey literature. Included articles were categorised according to the six strategic directions in the NSW Aboriginal Oral Health Plan. Four studies were related to the first strategic direction, six related to strategic direction two, four related to strategic direction three, six initiatives related to strategic direction four, five related to strategic direction five, and eight related to strategic direction six. While there has been significant progress in achieving the strategic directions of the NSW Aboriginal Oral Health Plan, there is scope for continued collaboration between oral health service providers, universities and Aboriginal communities to improve oral health outcomes for Aboriginal people in NSW.

RESUMEN

OBJECTIVE: An understanding of the leading causes of death in patients with head and neck squamous cell carcinoma (HNSCC) would be helpful to inform doctors, patients, and healthcare providers on disease management. This study aimed to comprehensively study the leading causes of death in these survivors. METHODS: We investigated the trends of risk factors for major causes of death in patients with HNSCC. Causes of death in HNSCC were obtained from the Surveillance, Epidemiology, and End Results registries. We characterized trends in the 5-year cumulative mortality as well as risk factors associated with the ten leading causes of death. RESULTS: Among 48 297 deaths identified, the ten leading causes were as follows: HNSCC, heart disease, lung cancer, chronic obstructive pulmonary disease (COPD), cerebrovascular disease, pneumonia & influenza, accidents & adverse effects, esophagus cancer, chronic liver diseases, and septicemia. Non-HNSCC deaths surpassed HNSCC deaths 4 years after cancer diagnosis. There was a significant decline in the 5-year cumulative mortality from HNSCC, heart disease, lung cancer, COPD, cerebrovascular disease, and esophagus cancer. The risks of mortality from the ten leading causes varied with patient characteristics. CONCLUSION: Our findings provide a useful picture of mortality patterns in HNSCC survivors, which might help when planning personalized HNSCC care.

Asunto(s)

RESUMEN

Current synthetic elastomers suffer from the well-known trade-off between toughness and stiffness. By a combination of multiscale experiments and atomistic simulations, a transparent unfilled elastomer with simultaneously enhanced toughness and stiffness is demonstrated. The designed elastomer comprises homogeneous networks with ultrastrong, reversible, and sacrificial octuple hydrogen bonding (HB), which evenly distribute the stress to each polymer chain during loading, thus enhancing stretchability and delaying fracture. Strong HBs and corresponding nanodomains enhance the stiffness by restricting the network mobility, and at the same time improve the toughness by dissipating energy during the transformation between different configurations. In addition, the stiffness mismatch between the hard HB domain and the soft poly(dimethylsiloxane)-rich phase promotes crack deflection and branching, which can further dissipate energy and alleviate local stress. These cooperative mechanisms endow the elastomer with both high fracture toughness (17016 J m-2 ) and high Young's modulus (14.7 MPa), circumventing the trade-off between toughness and stiffness. This work is expected to impact many fields of engineering requiring elastomers with unprecedented mechanical performance.

RESUMEN

An unprecedented radical cross-coupling reaction was achieved between glycine esters and racemic α-bromoketones catalyzed by synergistic Brønsted acid/photoredox catalysis, thus serving as an efficient platform for the synthesis of highly valuable enantioenriched unnatural α-amino acid derivatives. This dual catalysis provides a powerful capability to control the reactive radical intermediate and iminium ion, thereby enabling enantioconvergent bond-formation in a highly stereochemical manner. An array of valuable enantioenriched unnatural α-amino acid derivatives bearing two contiguous stereogenic centers are readily accessible with high diastereoselectivity and excellent enantioselectivity, which include α-amino acids with a unique ß-fluorinated quaternary stereocenter or its ß-all-carbon counterpart. A strong chiral amplification effect was observed in this dual catalytic system.

RESUMEN

Effective chimeric antigen receptor (CAR)-T cell therapy is dependent on optimal cell culture methods conducive to the activation and expansion of T cells ex vivo, as well as infection with CAR. Media formulations used in CAR-T cell manufacturing have not been optimized for gene delivery, cell expansion, and overall potency. Bioactive components and derivatives that support the generation of functionally-competent T cell progeny with long-lasting persistence are largely undefined. Current media formulations rely on fetal bovine serum (FBS) or human serum (HS), which suffer from a lack of consistency or supply issues. We recognize that components of blood cellular fractions that are absent in serum may have therapeutic value. Here we investigate whether a concentrated growth factor extract, purified from human transfusion grade whole blood fractions, and marketed as PhysiologixTM xeno-free (XF) hGFC (Phx), supports CAR-T cell expansion and function. We show that Phx supports T cell proliferation in clinical and research-grade media. We also show that Phx treatment enhances lentiviral-mediated gene expression across a wide range of multiplicity of infections (MOIs). We compared the ability of anti-GD-2 CAR-T cells expanded ex vivo in medium conditioned with either Phx or HS to clear tumor burden in a human xenograft model of neuroblastoma. We show that T cells expanded in Phx have superior engraftment and potency in vivo, as well as CAR-induced cytolytic activity in vitro. Metabolomic profiling revealed several factors unique to Phx that may have relevance for CAR-T cell preclinical discovery, process development, and manufacturing. In particular, we show that carnosine, a biogenic amine modestly enriched in Phx relative to HS, enhances lentiviral gene delivery in activated T cells. By limiting extracellular acidification, carnosine enhances the metabolic fitness of T cells, shifting their metabolic profile from an acidic, stressed state toward an oxidative, energetic state. These findings are very informative regarding potential derivatives to include in medium customized for gene delivery and overall potency for T cell adoptive immunotherapies.

RESUMEN

Automatic fovea localization is a challenging issue. In this article, we focus on the study of fovea localization and propose a robust fovea localization method. We propose concentric circular sectional symmetry measure (CCSSM) for symmetry axis detection, and region of interest (ROI) determination, which is a global feature descriptor robust against local feature changes, to solve the lesion interference issue, i.e., fovea visibility interference from lesions, using both structure features and morphological features. We propose the index of convexity and concavity (ICC) as the convexity-concavity measure of the surface and provide a quantitative evaluation tool for ophthalmologists to learn whether the occurrence of lesion within the ROI. We propose the weighted gradient accumulation map, which is insensitive to local intensity changes and can overcome the influence of noise and contamination, to perform refined localization. The advantages of the proposed method lies in two aspects. First, the accuracy and robustness can be achieved without typical sophisticated manner, i.e., blood vessel segmentation and parabola fitting. Second, the lesion interference is considered in our plan of fovea localization. Our proposed symmetry-based method is innovative in the solution of fovea detection, and it is simple, practical, and controllable. Experiment results show that the proposed method can resist the interference of unbalanced illumination and lesions, and achieve high accuracy rate in five datasets. Compared to the state-of-the-art methods, high robustness and accuracy of the proposed method guarantees its reliability.

Asunto(s)

RESUMEN

The first de novo construction of enantioenriched dihydroquinazolinones via an intermolecular strategy has been established. This approach also represents the first catalytic asymmetric [4+2] cycloaddition of vinyl benzoxazinanones with sulfonyl isocyanates, which afforded chiral dihydroquinazolinones in high yields and excellent enantioselectivities (up to 98% yield, 99 : 1 er). This reaction not only confronts the great challenge in de novo construction of enantioenriched dihydroquinazolinone skeletons, but also advances the chemistry of decarboxylative cycloadditions involving vinyl benzoxazinanones.

RESUMEN

AIM: To explore feasibility and practicability of macula localization independent of macular morphological features. METHODS: A novel method was proposed to identify macula in fundus images by using structure label transfer. Its main idea was to match a processed image with the candidate images with known structures, and then transfer the structure label representing the macular to the processed image as a result of macula localization. In this way, macula localization couldn't be influenced by lesion or other interference any more. RESULTS: The average success rate in four datasets was 98.18%. For accuracy, the average error distance in four datasets was 0.151 optic disc diameter (ODD). Even for severe lesion images, the proposed method can still maintain high success rate and high accuracy, e.g., 95.65% and 0.124 ODD in the case of STARE dataset, respectively, which indicated that the proposed method was highly robust and stable in the complicated situations. CONCLUSION: The proposed method can avoid the interference of lesion to macular morphological features in macula localization, and can locate macula with high accuracy and robustness, verifying its feasibility.

RESUMEN

Fresh blue algal from Chao Lake was used in this study. The crude extracts of phycocyanin were obtained with freeze-thaw method. The purification of phycocyanin was performed by combining two-step salt precipitation and two-step column chromatography. The reagent grade phycocyanin was achieved. Phycocyanin and impurity solution were obtained respectively in various stages subjected to the UV-Vis absorption spectrum scanning. With the development of the four-step purification process, the absorption peak of phycocyanin solution was redshifted from 260 to 280 nm in the wavelength range from 250 to 300 nm, and the maximum absorption peak of phycocyanin was redshifted from 617 to 620 nm in the wavelength range from 500nm to 700 nm. In the wavelength range from 250 to 700 nm, it showed that the impurity solution mainly contained impurity proteins and part of the phycocyanin in the first salting out, and mainly contained nucleic acids and vitamins substance in the second salting out. The first outflow components mainly contained phycoerythrin separated by the first column chromatography. The last outflow components mainly contained allophycocyanin separated by the second column chromatography. After the four-step purification process, the final purity of phycocyanin (A620/A280) is greater than 4,which met the standard of reagent grade．Thus it can be seen that two-step salt precipitation had a main function which was to remove impurity proteins, nucleic acids and vitamins substance, and two-step column chromatography main function was to remove phycoerythrin and allophycocyanin which were similar to phycocyanin.

Asunto(s)

RESUMEN

An NHC-triggered, transition-metal-free strategy for the efficient synthesis of 2,3-disubstituted benzofuran derivatives in moderate to excellent yields from aryl or alkyl aldehydes and o-quinone methides has been developed. This method features mild reaction conditions, operational simplicity, broad substrate scope and convergent assembly.

RESUMEN

A straightforward N-heterocyclic carbene (NHC)/LiCl-mediated synthesis of dihydropyranones from α,ß-unsaturated carboxylic acids and 1,3-dicarbonyl compounds was realized through the in situ activation strategy. The key advantages of this protocol include ready availability and high stability of starting materials, good yields, and excellent enantioselectivity.

Asunto(s)