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1.
Int J Surg ; 2024 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-38573083

RESUMEN

BACKGROUND: Treatment and follow-up strategies for silent gallbladder stones in patients before kidney transplantation (KT) remain unknown. Therefore, we aimed to elucidate the role of pre-KT cholecystectomy in preventing biliary and surgical complications. MATERIALS AND METHODS: This study retrospectively analyzed 2,295 KT recipients and 3,443 patients waiting for KT at a single tertiary center from January 2005 to July 2022. The primary outcomes were the incidences of biliary and post-cholecystectomy complications in KT recipients. Firth's logistic regression model was used to assess the risk factors for biliary complications. RESULTS: Overall, 543 patients awaiting KT and 230 KT recipients were found to have biliary stones. Among the KT recipients, 16 (7%) underwent cholecystectomy before KT, while others chose to observe their biliary stones. Pre-KT cholecystectomy patients did not experience any biliary complications, and 20 (9.3%) patients who chose to observe their stones experienced complications. Those who underwent cholecystectomy before KT developed fewer post-cholecystectomy complications (6.3%) compared with those who underwent cholecystectomy after KT (38.8%, P=0.042), including reduced occurrences of fatal postoperative complications based on the Clavien-Dindo classification. Multiple stones (odds ratio [OR], 3.09; 95% confidence interval [CI], 1.07-8.90; P=0.036), thickening of the gallbladder wall (OR, 5.39; 95% CI, 1.65-17.63; P=0.005), and gallstones>1 cm in size (OR 5.12, 95% CI: 1.92-13.69, P=0.001) were independent risk factors for biliary complications. Among patients awaiting KT, 23 (4.2%) underwent cholecystectomy during the follow-up, resulting in one post-cholecystectomy complication. CONCLUSION: Gallstone-related biliary complications following KT and subsequent cholecystectomy was associated with more serious complications and worse treatment outcomes. Therefore, when KT candidates had risk factor for biliary complications, preemptive cholecystectomy for asymptomatic cholecystolithiasis could be considered to reduce further surgical risk.

2.
Gastrointest Endosc ; 2024 Feb 29.
Artículo en Inglés | MEDLINE | ID: mdl-38431102

RESUMEN

BACKGROUND AND AIMS: It is difficult to differentiate between neoplastic and non-neoplastic gallbladder (GB) polyps before surgery. Endoscopic ultrasound-elastography (EUS-EG) is a non-invasive complementary diagnostic method. The utility of EUS-EG in the differential diagnosis of GB polyps has not been investigated. We aimed to investigate the diagnostic performance of EUS-EG for the differential diagnosis of GB polyps. METHODS: Patients with GB polyps were prospectively enrolled from June 2020 until November 2022. EUS-EG and semi-quantitative evaluation of the strain ratio (SR) were performed for differential diagnosis of GB polyps. Fifty-three eligible patients were divided into two groups based on the final diagnosis after surgery. Patient demographics, EUS characteristics, and SR values were compared. Receiver-operating characteristic (ROC) curve analysis was performed to determine the optimal cutoff SR value that discriminates between neoplastic and non-neoplastic GB polyps. RESULTS: The median SR value for neoplastic polyps (32.93 [interquartile range: 22.37-69.02]) was significantly higher than for non-neoplastic polyps (5.40 [2.36-14.44]; p<0.001). There were significant differences in SR values between non-neoplastic, benign neoplastic (23.38 [13.62-39.04]), and malignant polyps (49.25 [27.90-82.00]). The optimal cut-off SR value to differentiate between neoplastic and non-neoplastic polyps was 18.4. In multivariable logistic regression, SR value >18.4 (odds ratio 33.604, 95% confidence interval 2.588-436.292) was an independent predictor of neoplastic polyps. CONCLUSIONS: EUS-EG and SR values can be used as a supplementary method for evaluating GB polyps.

3.
Cancers (Basel) ; 16(5)2024 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-38473413

RESUMEN

Pancreatic cancer is characterized by fibrosis/desmoplasia in the tumor microenvironment, which is primarily mediated by pancreatic stellate cells and cancer-associated fibroblasts. HGF/c-MET signaling, which is instrumental in embryonic development and wound healing, is also implicated for its mitogenic and motogenic properties. In pancreatic cancer, this pathway, along with its downstream signaling pathways, is associated with disease progression, prognosis, metastasis, chemoresistance, and other tumor-related factors. Other features of the microenvironment in pancreatic cancer with the HGF/c-MET pathway include hypoxia, angiogenesis, metastasis, and the urokinase plasminogen activator positive feed-forward loop. All these attributes critically influence the initiation, progression, and metastasis of pancreatic cancer. Therefore, targeting the HGF/c-MET signaling pathway appears promising for the development of innovative drugs for pancreatic cancer treatment. One of the primary downstream effects of c-MET activation is the MAPK/ERK (Ras, Ras/Raf/MEK/ERK) signaling cascade, and MEK (Mitogen-activated protein kinase kinase) inhibitors have demonstrated therapeutic value in RAS-mutant melanoma and lung cancer. Trametinib is a selective MEK1 and MEK2 inhibitor, and it has evolved as a pivotal therapeutic agent targeting the MAPK/ERK pathway in various malignancies, including BRAF-mutated melanoma, non-small cell lung cancer and thyroid cancer. The drug's effectiveness increases when combined with agents like BRAF inhibitors. However, resistance remains a challenge, necessitating ongoing research to counteract the resistance mechanisms. This review offers an in-depth exploration of the HGF/c-MET signaling pathway, trametinib's mechanism, clinical applications, combination strategies, and future directions in the context of pancreatic cancer.

4.
Cancers (Basel) ; 15(19)2023 Sep 25.
Artículo en Inglés | MEDLINE | ID: mdl-37835402

RESUMEN

Savolitinib is a highly selective small molecule inhibitor of the mesenchymal epithelial transition factor (MET) tyrosine kinase, primarily developed for the treatment of non-small cell lung cancer (NSCLC) with MET mutations. It is also being investigated as a treatment for breast, head and neck, colorectal, gastric, pancreatic, and other gastrointestinal cancers. In both preclinical and clinical studies, it has demonstrated efficacy in lung, kidney, and stomach cancers. Savolitinib is an oral anti-cancer medication taken as a 600 mg dose once daily. It can be used as a monotherapy in patients with non-small cell lung cancer with MET mutations and in combination with epidermal growth factor receptor (EGFR) inhibitors for patients who have developed resistance to them. Furthermore, savolitinib has shown positive results in gastric cancer treatment, particularly in combination with docetaxel. As a result, this review aims to validate its efficacy in NSCLC and suggests its potential application in other gastrointestinal cancers, such as pancreatic cancer, based on related research in gastric and renal cancer.

5.
Nat Commun ; 14(1): 4149, 2023 Jul 12.
Artículo en Inglés | MEDLINE | ID: mdl-37438468

RESUMEN

Lithium-rich layered oxides, despite their potential as high-energy-density cathode materials, are impeded by electrochemical performance deterioration upon anionic redox. Although this deterioration is believed to primarily result from structural disordering, our understanding of how it is triggered and/or occurs remains incomplete. Herein, we propose a theoretical picture that clarifies the irreversible transformation and redox asymmetry of lithium-rich layered oxides by introducing a series of global and local dynamic structural evolution processes involving slab gliding and transition-metal migration. We show that slab gliding plays a key role in trigger/initiating the structural disordering and consequent degradation of the anionic redox reaction. We further reveal that the 'concerted disordering mechanism' of slab gliding and transition-metal migration produces spontaneously irreversible/asymmetric lithiation and de-lithiation pathways, causing irreversible structural deterioration and the asymmetry of the anionic redox reaction. Our findings suggest slab gliding as a crucial, yet underexplored, method for achieving a reversible anionic redox reaction.

6.
Sci Adv ; 8(30): eabq0153, 2022 Jul 29.
Artículo en Inglés | MEDLINE | ID: mdl-35895830

RESUMEN

All-solid-state batteries are a potential game changer in the energy storage market; however, their practical employment has been hampered by premature short circuits caused by the lithium dendritic growth through the solid electrolyte. Here, we demonstrate that a rational layer-by-layer strategy using a lithiophilic and electron-blocking multilayer can substantially enhance the performance/stability of the system by effectively blocking the electron leakage and maintaining low electronic conductivity even at high temperature (60°C) or under high electric field (3 V) while sustaining low interfacial resistance (13.4 ohm cm2). It subsequently results in a homogeneous lithium plating/stripping, thereby aiding in achieving one of the highest critical current densities (~3.1 mA cm-2) at 60°C in a symmetric cell. A full cell paired with a commercial-level cathode exhibits exceptionally long durability (>3000 cycles) and coulombic efficiency (99.96%) at a high current density (2 C; ~1.0 mA cm-2), which records the highest performance among all-solid-state lithium metal batteries reported to date.

7.
Nat Mater ; 21(6): 664-672, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35301474

RESUMEN

Lattice oxygen redox offers an unexplored way to access superior electrochemical properties of transition metal oxides (TMOs) for rechargeable batteries. However, the reaction is often accompanied by unfavourable structural transformations and persistent electrochemical degradation, thereby precluding the practical application of this strategy. Here we explore the close interplay between the local structural change and oxygen electrochemistry during short- and long-term battery operation for layered TMOs. The substantially distinct evolution of the oxygen-redox activity and reversibility are demonstrated to stem from the different cation-migration mechanisms during the dynamic de/intercalation process. We show that the π stabilization on the oxygen oxidation initially aids in the reversibility of the oxygen redox and is predominant in the absence of cation migrations; however, the π-interacting oxygen is gradually replaced by σ-interacting oxygen that triggers the formation of O-O dimers and structural destabilization as cycling progresses. More importantly, it is revealed that the distinct cation-migration paths available in the layered TMOs govern the conversion kinetics from π to σ interactions. These findings constitute a step forward in unravelling the correlation between the local structural evolution and the reversibility of oxygen electrochemistry and provide guidance for further development of oxygen-redox layered electrode materials.


Asunto(s)
Óxidos , Oxígeno , Suministros de Energía Eléctrica , Electroquímica , Oxidación-Reducción , Oxígeno/química
8.
Adv Sci (Weinh) ; 9(10): e2104829, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-35104055

RESUMEN

3D hosts are promising to extend the cycle life of lithium metal anodes but have rarely been implemented with lean electrolytes thus impacting the practical cell energy density. To overcome this challenge, a 3D host that is lightweight and easy to fabricate with optimum pore size that enables full utilization of its pore volume, essential for lean electrolyte operations, is reported. The host is fabricated by casting a VGCF (vapor-grown carbon fiber)-based slurry loaded with a sparingly soluble rubidium nitrate salt as an additive. The network of fibers generates uniform pores of ≈3 µm in diameter with a porosity of 80%, while the nitrate additive enhances lithiophilicity. This 3D host delivers an average coulombic efficiency of 99.36% at 1 mA cm-2 and 1 mAh cm-2 for over 860 cycles in half-cell tests. Full cells containing an anode with 1.35-fold excess lithium paired with LiNi0.8 Mn0.1 Co0.1 O2 (NMC811) cathodes exhibit capacity retention of 80% over 176 cycles at C/2 under a lean electrolyte condition of 3 g Ah-1 . This work provides a facile and scalable method to advance 3D lithium hosts closer to practical lithium-metal batteries.

9.
Adv Mater ; 33(10): e2004902, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33533125

RESUMEN

The production of rechargeable batteries is rapidly expanding, and there are going to be new challenges in the near future about how the potential environmental impact caused by the disposal of the large volume of the used batteries can be minimized. Herein, a novel strategy is proposed to address these concerns by applying biodegradable device technology. An eco-friendly and biodegradable sodium-ion secondary battery (SIB) is developed through extensive material screening followed by the synthesis of biodegradable electrodes and their seamless assembly with an unconventional biodegradable separator, electrolyte, and package. Each battery component decomposes in nature into non-toxic compounds or elements via hydrolysis and/or fungal degradation, with all of the biodegradation products naturally abundant and eco-friendly. Detailed biodegradation mechanisms and toxicity influence of each component on living organisms are determined. In addition, this new SIB delivers performance comparable to that of conventional non-degradable SIBs. The strategy and findings suggest a novel eco-friendly biodegradable paradigm for large-scale rechargeable battery systems.

10.
Angew Chem Int Ed Engl ; 59(42): 18662-18669, 2020 Oct 12.
Artículo en Inglés | MEDLINE | ID: mdl-32668043

RESUMEN

The rampant generation of lithium hydroxide and carbonate impurities, commonly known as residual lithium, is a practical obstacle to the mass-scale synthesis and handling of high-nickel (>90 %) layered oxides and their use as high-energy-density cathodes for lithium-ion batteries. Herein, we suggest a simple in situ method to control the residual lithium chemistry of a high-nickel lithium layered oxide, Li(Ni0.91 Co0.06 Mn0.03 )O2 (NCM9163), with minimal side effects. Based on thermodynamic considerations of the preferred reactions, we systematically designed a synthesis process that preemptively converts residual Li2 O (the origin of LiOH and Li2 CO3 ) into a more stable compound by injecting reactive SO2 gas. The preformed lithium sulfate thin film significantly suppresses the generation of LiOH and Li2 CO3 during both synthesis and storage, thereby mitigating slurry gelation and gas evolution and improving the cycle stability.

11.
Nat Mater ; 19(4): 419-427, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-31959949

RESUMEN

Despite the high energy density of lithium-rich layered-oxide electrodes, their real-world implementation in batteries is hindered by the substantial voltage decay on cycling. This voltage decay is widely accepted to mainly originate from progressive structural rearrangements involving irreversible transition-metal migration. As prevention of this spontaneous cation migration has proven difficult, a paradigm shift toward management of its reversibility is needed. Herein, we demonstrate that the reversibility of the cation migration of lithium-rich nickel manganese oxides can be remarkably improved by altering the oxygen stacking sequences in the layered structure and thereby dramatically reducing the voltage decay. The preeminent intra-cycle reversibility of the cation migration is experimentally visualized, and first-principles calculations reveal that an O2-type structure restricts the movements of transition metals within the Li layer, which effectively streamlines the returning migration path of the transition metals. Furthermore, we propose that the enhanced reversibility mitigates the asymmetry of the anionic redox in conventional lithium-rich electrodes, promoting the high-potential anionic reduction, thereby reducing the subsequent voltage hysteresis. Our findings demonstrate that regulating the reversibility of the cation migration is a practical strategy to reduce voltage decay and hysteresis in lithium-rich layered materials.

12.
Nano Lett ; 19(1): 29-37, 2019 01 09.
Artículo en Inglés | MEDLINE | ID: mdl-30365316

RESUMEN

The thermodynamic instability of the LiCoO2 layered structure at >0.5Li extraction has been considered an obstacle for the reversible utilization of its near theoretical capacity at high cutoff voltage (>4.6 V vs Li/Li+) in lithium-ion batteries. Many previous studies have focused on resolving this issue by surface modification of LiCoO2, which has proven to be effective in suppressing phase transformation. To determine the extent to which surface protection of LiCoO2 is effective despite its thermodynamic instability and presumably incomplete reversibility involving the O1 phase, here we verify the intrinsic reversibility of bulk LiCoO2 with extended lithium extraction by ruling out the effect of a surface. Specifically, first, we show that, contrary to conventional belief, electrochemical cycling of LiCoO2 at a cutoff voltage of 4.8 V (vs Li/Li+) results in better cycle stability and lower polarizations than those at 4.6 V. We demonstrate, using an exhaustive suite of characterization tools, that the rapid cycle degradation under high-voltage cycling is mostly caused by the formation of a surface resistive layer; however, these damaged surfaces are leached out faster than they are accumulated above a certain potential, which results in superior cyclability compared with that achieved for less oxidative 4.6-V cycling. This beneficial leaching out of the resistive surface layer serves as a "subtractive" surface modification and plays a role in enhancing the cycle stability and is distinguished from conventional "additive" surface modification such as coating. This approach allows us to decouple factors of the bulk and surface degradations that contribute to the capacity fade and leads to the finding that, in the absence of a resistive surface, the capacity retention of a LiCoO2 electrode with 4.8-V cutoff cycling can be intrinsically high, indicating that the instability of the crystalline Li xCoO2 ( x < 0.5) has a limited effect on the cycle stability. Our findings also explain why the strategy of coating foreign materials on the surface of LiCoO2 can improve the high-voltage cycling to some extent despite the expected thermodynamic instability of the highly charged phase.

14.
Sci Rep ; 8(1): 10366, 2018 Jul 04.
Artículo en Inglés | MEDLINE | ID: mdl-29970900

RESUMEN

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.

15.
Sci Rep ; 8(1): 8066, 2018 May 23.
Artículo en Inglés | MEDLINE | ID: mdl-29795278

RESUMEN

All-solid-state batteries are considered as one of the attractive alternatives to conventional lithium-ion batteries, due to their intrinsic safe properties benefiting from the use of non-flammable solid electrolytes in ASSBs. However, one of the issues in employing the solid-state electrolyte is the sluggish ion transport kinetics arising from the chemical and physical instability of the interfaces among solid components including electrode material, electrolyte and additive agents. In this work, we investigate the stability of the interface between carbon conductive agents and Li10GeP2S12 in a composite cathode and its effect on the electrochemical performance of ASSBs. It is found that the inclusion of various carbon conductive agents in composite cathode leads to inferior kinetic performance of the cathode despite expectedly enhanced electrical conductivity of the composite. We observe that the poor kinetic performance is attributed to a large interfacial impedance which is gradually developed upon the inclusions of the various carbon conductive agents regardless of their physical differences. The analysis through X-ray Photoelectron Spectroscopy suggests that the carbon additives in the composite cathode stimulate the electrochemical decomposition of LGPS electrolyte degrading its surface during cycling, indicating the large interfacial resistance stems from the undesirable decomposition of the electrolyte at the interface.

16.
Pharmacology ; 86(1): 37-43, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20588074

RESUMEN

The present study was undertaken to investigate the influence of resveratrol on vascular smooth muscle contractility and to determine the mechanism involved. Denuded aortic rings from male rats were used and isometric contractions were recorded and combined with molecular experiments. Resveratrol at a low concentration (0.03 mmol/l) relaxed directly and more markedly fluoride-induced vascular contraction than phorbol ester-induced contraction. Furthermore, resveratrol more markedly inhibited fluoride-induced increases in pMYPT1 levels than phorbol ester-induced increases. It also more markedly inhibited fluoride-induced increases in pMYPT1 levels than pERK1/2 levels, suggesting that the mechanism involved the inhibition of Rho-kinase activity and the subsequent phosphorylation of MYPT1. This study provides evidence regarding the mechanism underlying the relaxation effect of resveratrol on agonist-induced vascular contraction regardless of endothelial function.


Asunto(s)
Aorta Torácica/efectos de los fármacos , Músculo Liso Vascular/efectos de los fármacos , Estilbenos/farmacología , Vasodilatadores/farmacología , Quinasas Asociadas a rho/antagonistas & inhibidores , Animales , Aorta Torácica/enzimología , Western Blotting , Calcio/metabolismo , Activadores de Enzimas/farmacología , Técnicas In Vitro , Contracción Isométrica/efectos de los fármacos , Masculino , Proteína Quinasa 1 Activada por Mitógenos/metabolismo , Proteína Quinasa 3 Activada por Mitógenos/metabolismo , Relajación Muscular/efectos de los fármacos , Músculo Liso Vascular/fisiología , Ésteres del Forbol/farmacología , Fosforilación , Cloruro de Potasio/farmacología , Proteína Fosfatasa 1/metabolismo , Ratas , Ratas Sprague-Dawley , Resveratrol , Fluoruro de Sodio/farmacología , Estilbenos/administración & dosificación , Vasodilatadores/administración & dosificación , Quinasas Asociadas a rho/metabolismo
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