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1.
J Surg Educ ; 81(12): 103291, 2024 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-39369512

RESUMO

AIM: This study aimed to develop a blended training module focusing on ethical approaches within general surgery residency training and to assess the impact of this training on participants. METHODS: Based on the literature review and input from both general surgery residents and trainers, 14 topics were identified, and corresponding learning objectives were formulated. The training was conducted through a blended learning module, which encompassed online video presentations alongside face-to-face sessions involving real-life cases. Assessment of the training involved administering test-formatted exams both before and after the training, which assessed the learning objectives of the 14 topics. These exams comprised multiple-choice questions and true/false inquiries based on case-based propositions. Additionally, feedback regarding the training was solicited from the residents. RESULTS: The study involved 20 general surgery residents. Assessment revealed a statistically significant increase in exam success among the residents after the training (p<0.001). Additionally, feedback indicated that the training model was effective. CONCLUSIONS: Developing a blended learning module that combines online and face-to-face education, supplemented with real-life case studies, and incorporating discussions on ethical dilemmas during face-to-face sessions, along with assessment through exams, will significantly enhance the proficiency of residents in surgical ethics.

4.
Angew Chem Int Ed Engl ; : e202417624, 2024 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-39345165

RESUMO

Regulating the transformation of sulfur species is the key to improving the electrochemical performance of lithium-sulfur (Li-S) batteries, in particular, to accelerate the reversible conversion between solid phase Li2S2 and Li2S. Herein, we introduced Spidroin, which is a main protein in spider silk, as a dual functional separator coating in Li-S batteries to effectively adsorb polysulfides via the sequence of amino acids in its primary structure and regulate Li+ flux through the ß-sheet of its secondary structure, thus accelerating the reversible transformation between Li2S2 and Li2S. Spidroin-based Li-S cells exhibited an exceptional electrochemical performance with a high specific capacity of  744.1 mAh g-1 at 5C and a high areal capacity of 7.5 mAh cm-2 at a low electrolyte-to-sulfur (E/S) ratio of 6 µL mgs-1 and a sulfur loading of 8.6 mgs cm-2.

5.
Chimia (Aarau) ; 78(6): 415-422, 2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-38946414

RESUMO

The surge in greenhouse gas emissions, predominantly in the form of carbon dioxide (CO2) spurred by the Industrial Revolution, has surpassed the critical threshold of 400 ppm, fueling global warming, ocean acidification, and climate change. To mitigate the adverse effects of these emissions and limit the global temperature rise to below 2 °C, the ambitious target of achieving net zero emissions by 2050 was established in the Paris Agreement. Current state-of-the-art technologies, such as amine scrubbing, remain problematic owing to their high energy requirements, susceptibility to corrosion, and other operational challenges. Owing to the lack of suitable technologies coupled with escalating energy demand, there is still a significant amount of carbon dioxide being released into the atmosphere. Accordingly, there is an urgent need for the development of alternative technologies that offer high efficiency, low energy consumption, cost-effective installation, and operation. In this review, we delve into the emerging technologies poised to address these challenges, evaluating their maturity levels in comparison to existing commercially available solutions. Furthermore, we provide a brief overview of ongoing efforts aimed at commercializing these innovative technologies.

6.
Angew Chem Int Ed Engl ; 63(35): e202408238, 2024 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-38860886

RESUMO

Sulfide-based all-solid-state battery (ASSB) with a lithium metal anode (LMA) is a promising candidate to surpass conventional Li-ion batteries owing to their inherent safety against fire hazards and potential to achieve a higher energy density. However, the narrow electrochemical stability window and chemical reactivity of the sulfide solid electrolyte towards the LMA results in interfacial degradation and poor electrochemical performance. In this direction, we introduce an organic additive approach, that is the mixing of prelithiated trithiocyanuric acid, Li3TCA, with Li6PS5Cl, to establish a stable interface while preserving high ionic conductivity. Including 2.5 wt % Li3TCA alleviates the decomposition of the electrolyte on the lithium metal interface, decreasing the Li2S content in the solid-electrolyte interface (SEI) thus forming a more stable interface. In Li|Li symmetric cells, this strategy enables a rise in the critical current density from 1.0 to 1.9 mA cm-2 and stable cycling for over 750 hours at a high current density of 1.0 mA cm-2. This approach also enables Li|NbO-NCM811 full cell to operate more than 500 cycles at 0.3 C.

7.
Biomacromolecules ; 25(3): 1637-1648, 2024 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-38381566

RESUMO

Cellulose nanocrystals (CNCs) are bio-based, rod-like, high-aspect-ratio nanoparticles with high stiffness and strength and are widely used as a reinforcing nanofiller in polymer nanocomposites. However, due to hydrogen-bond formation between the large number of hydroxyl groups on their surface, CNCs are prone to aggregate, especially in nonpolar polymer matrices. One possibility to overcome this problem is to graft polymers from the CNCs' surfaces and to process the resulting "hairy nanoparticles" (HNPs) into one-component nanocomposites (OCNs) in which the polymer matrix and CNC filler are covalently connected. Here, we report OCNs based on HNPs that were synthesized by grafting gradient diblock copolymers onto CNCs via surface-initiated atom transfer radical polymerization. The inner block (toward the CNCs) is composed of poly(methyl acrylate) (PMA), and the outer block comprises a gradient copolymer rich in poly(methyl methacrylate) (PMMA). The OCNs based on such HNPs microphase separate into a rubbery poly(methyl acrylate) phase that dissipates mechanical energy and imparts toughness, a glassy PMMA phase that provides strength and stiffness, and well-dispersed CNCs that further reinforce the materials. This design afforded OCNs that display a considerably higher stiffness and strength than reference diblock copolymers without the CNCs. At the same time, the extensibility remains high and the toughness is increased up to 5-fold relative to the reference materials.


Assuntos
Acrilatos , Nanocompostos , Nanopartículas , Celulose/química , Polimetil Metacrilato , Polímeros/química , Nanopartículas/química , Nanocompostos/química
8.
Chem Commun (Camb) ; 60(19): 2657-2660, 2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-38348903

RESUMO

We report the synthesis of two-dimensional and three-dimensional porous polyphenylenes (2D/3D-pPPs) via the Diels-Alder cycloaddition polymerization reaction. The resulting 2D and 3D-pPPs showed surface areas up to 1553 m2 g-1, pore volumes of 1.45 cm3 g-1 and very high H2 uptake capacities of 7.4 and 7.1 wt% at 77 K, respectively, along with a competitive high-pressure CO2 and CH4 uptake performance.

9.
Chimia (Aarau) ; 77(3): 122-126, 2023 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-38047814

RESUMO

Palladium (Pd) recycling from waste materials is an important approach in order to meet the growing demand for Pd originating from its broad range of applications including automotive industry, electronics and catalysis. In this article, we discuss the design principles of solid-sorbents for efficient recovery of Pd from waste sources with a particular emphasis on porous organic polymers (POPs), which emerged as promising porous materials for Pd recovery due to their tunable chemical functionality, stability and porosity. We discuss the critical role of binding sites and porosity in the Pd uptake capacity, adsorption kinetics and selectivity. We also highlight the use of captured Pd within the polymer networks as heterogeneous catalysts for cross-coupling reactions.

10.
Angew Chem Int Ed Engl ; 62(38): e202309775, 2023 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-37533138

RESUMO

Phthalocyanines (PCs) are intriguing building blocks owing to their stability, physicochemical and catalytic properties. Although PC-based polymers have been reported before, many suffer from relatively low stability, crystallinity, and low surface areas. Utilizing a mixed-metal salt ionothermal approach, we report the synthesis of a series of metallophthalocyanine-based covalent organic frameworks (COFs) starting from 1,2,4,5-tetracyanobenzene and 2,3,6,7-tetracyanoanthracene to form the corresponding COFs named M-pPPCs and M-anPPCs, respectively. The obtained COFs followed the Irving-Williams series in their metal contents, surface areas, and pore volume and featured excellent CO2 uptake capacities up to 7.6 mmol g-1 at 273 K, 1.1 bar. We also investigated the growth of the Co-pPPC and Co-anPPC on a highly conductive carbon nanofiber and demonstrated their high catalytic activity in the electrochemical CO2 reduction, which showed Faradaic efficiencies towards CO up to 74 % at -0.64 V vs. RHE.

11.
Chem Commun (Camb) ; 59(53): 8286-8289, 2023 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-37318309

RESUMO

We addressed the poor interfacial stability of the Li metal anode in Li-S batteries through molecular regulation of electrolytes using arylthiol additives with various numbers of anchoring sites. The dual functional tetrathiol additive markedly enhanced the Li anode interfacial stability, controlled the sulfur redox kinetics and suppressed side reactions towards polysulfides, thus leading to an improved capacity retention of 70% after 500 cycles at 1 C.


Assuntos
Eletrólitos , Lítio , Fontes de Energia Elétrica , Eletrodos , Enxofre
12.
Chemistry ; 29(42): e202301053, 2023 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-37159905

RESUMO

Porous organic polymers (POPs) have gained tremendous attention owing to their chemical tunability, stability and high surface areas. Whereas there are several examples of fully conjugated two-dimensional (2D) POPs, three-dimensional (3D) ones are rather challenging to realize in the absence of structural templates. Herein, we report the base-catalyzed direct synthesis of a fully conjugated 3D POPs, named benzyne-derived polymers (BDPs), containing biphenylene and tetraphenylene moieties starting from a simple bisbenzyne precursor, which undergoes [2+2] and [2+2+2+2] cycloaddition reactions to form BDPs primarily composed of biphenylene and tetraphenylene moieties. The resulting polymers exhibited ultramicroporous structures with surface areas up to 544 m2 g-1 and very high CO2 /N2 selectivities.

13.
ACS Appl Mater Interfaces ; 15(17): 21394-21402, 2023 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-37079299

RESUMO

Conventional synthetic strategies do not allow one to impart structural anisotropy into porous carbons, thus leading to limited control over their textural properties. While structural anisotropy alters the mechanical properties of materials, it also introduces an additional degree of directionality to increase the pore connectivity and thus the flux in the designed direction. Accordingly, in this work the structure of porous carbons prepared from resorcinol-formaldehyde gels has been rendered anisotropic by integrating superparamagnetic colloids to the sol-gel precursor solution and by applying a uniform magnetic field during the sol-gel transition, which enables the self-assembly of magnetic colloids into chainlike structures to template the growth of the gel phase. Notably, the anisotropic pore structure is maintained upon pyrolysis of the gel, leading to hierarchically porous carbon monoliths with tunable structure and porosities. With an advantage granted to anisotropic materials, these porous carbons showed higher porosity, a higher CO2 uptake capacity of 3.45 mmol g-1 at 273 K at 1.1 bar, and faster adsorption kinetics compared to the ones synthesized in the absence of magnetic field. Moreover, these materials were also used as magnetic sorbents with fast adsorption kinetics for efficient oil-spill cleanup and retrieved easily by using an external magnetic field.

14.
Nat Commun ; 14(1): 299, 2023 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-36653353

RESUMO

Fluorination of ether solvents is an effective strategy to improve the electrochemical stability of non-aqueous electrolyte solutions in lithium metal batteries. However, excessive fluorination detrimentally impacts the ionic conductivity of the electrolyte, thus limiting the battery performance. Here, to maximize the electrolyte ionic conductivity and electrochemical stability, we introduce the targeted trifluoromethylation of 1,2-dimethoxyethane to produce 1,1,1-trifluoro-2,3-dimethoxypropane (TFDMP). TFDMP is used as a solvent to prepare a 2 M non-aqueous electrolyte solution comprising bis(fluorosulfonyl)imide salt. This electrolyte solution shows an ionic conductivity of 7.4 mS cm-1 at 25 °C, an oxidation stability up to 4.8 V and an efficient suppression of Al corrosion. When tested in a coin cell configuration at 25 °C using a 20 µm Li metal negative electrode, a high mass loading LiNi0.8Co0.1Mn0.1O2-based positive electrode (20 mg cm-2) with a negative/positive (N/P) capacity ratio of 1, discharge capacity retentions (calculated excluding the initial formation cycles) of 81% after 200 cycles at 0.1 A g-1 and 88% after 142 cycles at 0.2 A g-1 are achieved.

15.
Nat Commun ; 13(1): 7299, 2022 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-36435832

RESUMO

Switchable gas separation membranes are intriguing systems for regulating the transport properties of gases. However, existing stimuli-responsive gas separation membranes suffer from either very slow response times or require high energy input for switching to occur. Accordingly, herein, we introduced light-switchable polymeric carbon nitride (pCN) gas separation membranes with fast response times prepared from melamine precursor through in-situ formation and deposition of pCN onto a porous support using chemical vapor deposition. Our systematic analysis revealed that the gas transport behavior upon light irradiation is fully governed by the polarizability of the permeating gas and its interaction with the charged pCN surface, and can be easily tuned either by controlling the power of the light and/or the duration of irradiation. We also demonstrated that gases with higher polarizabilities such as CO2 can be separated from gases with lower polarizability like H2 and He effectively with more than 22% increase in the gas/CO2 selectivity upon light irradiation. The membranes also exhibited fast response times (<1 s) and can be turned "on" and "off" using a single light source at 550 nm.

16.
Chem Soc Rev ; 51(23): 9831-9852, 2022 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-36374129

RESUMO

Porous organic polymers (POPs) have long been considered as prime candidates for carbon dioxide (CO2) capture, separation, and conversion. Especially their permanent porosity, structural tunability, stability and relatively low cost are key factors in such considerations. Whereas heteratom-rich microporous networks as well as their amine impregnation/functionalization have been actively exploited to boost the CO2 affinity of POPs, recently, the focus has shifted to engineering the pore environment, resulting in a new generation of highly microporous POPs rich in heteroatoms and featuring abundant catalytic sites for the capture and conversion of CO2 into value-added products. In this review, we aim to provide key insights into structure-property relationships governing the separation, capture and conversion of CO2 using POPs and highlight recent advances in the field.


Assuntos
Dióxido de Carbono , Polímeros , Porosidade , Dióxido de Carbono/química , Polímeros/química , Aminas/química
17.
Energy Fuels ; 36(18): 11051-11061, 2022 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-36148000

RESUMO

There exists an urgent demand for the advancement of technologies that reduce and capture carbon dioxide (CO2) emissions to mitigate anthropogenic contributions to climate change. This paper compares the maximum power densities achieved from the combination of reverse electrodialysis (RED) with carbon capture (CC) using various CC solvents. Carbon capture reverse electrodialysis (CCRED) harvests energy from the salinity gradients generated from the reaction of CO2 with specific solvents, generally amines. To eliminate the requirement of freshwater as an external resource, we took advantage of a semiclosed system that would allow the inputs to be industrial emissions and heat and the outputs to be electrical power, clean emissions, and captured CO2. We assessed the power density that can be attained using CCRED with five commonly studied CC solvents: monoethanolamine (MEA), diethanolamine (DEA), N-methyldiethanolamine (MDEA), 2-amino-2-methyl-2-propanol (AMP), and ammonia. We achieved the highest power density, 0.94 W m-2 cell-1, using ammonia. This work provides a foundation for future iterations of CCRED that may help to incentivize adoption of CC technology.

19.
ACS Cent Sci ; 8(7): 871-873, 2022 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-35912356
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