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A significant challenge in direct seawater electrolysis is the rapid deactivation of the cathode due to the large scaling of Mg(OH)2. Herein, we synthesized a Pt-coated highly disordered NiCu alloy (Pt-NiCu alloy) electrode with superior solidophobic behavior, enabling stable hydrogen generation (100 mA cm-2, >1000 h durability) and simultaneous production of Mg(OH)2 (>99.0% purity) in electrolyte enriched with Mg2+ and Ca2+. The unconventional solidophobic property primarily stems from the high surface energy of the NiCu alloy substrate, which facilitates the adsorption of surface water and thereby compels the bulk formation of Mg(OH)2 via homogeneous nucleation. The discovery of this solidophobic electrode will revolutionarily simplify the existing techniques for seawater electrolysis and increase the economic viability for seawater electrolysis.
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It has been well-established that light-matter interactions, as manifested by diverse linear and nonlinear optical (NLO) processes, are mediated by real and virtual particles, such as electrons, phonons, and excitons. Polarons, often regarded as electrons dressed by phonons, are known to contribute to exotic behaviors of solids, from superconductivity to photocatalysis, while their role in materials' NLO response remains largely unexplored. Here, the NLO response mediated by polarons supported by a model ionic metal oxide, TiO2, is examined. It is observed that the formation of polaronic states within the bandgap results in a dramatic enhancement of NLO absorption coefficient by over 130 times for photon energies in the sub-bandgap regions, characterized by a 100 fs scale ultrafast response that is typical for thermalized electrons in metals. The ultrafast polaronic NLO response is then exploited for the development of all-optical switches for ultrafast pulse generation in near-infrared (NIR) fiber lasers and modulation of optical signal in the telecommunication band based on evanescent interaction on a planar waveguide chip. These results suggest that the polarons supported by dielectric ionic oxides can fill the gaps left by dielectric and metallic materials and serve as a novel platform for nonlinear photonic applications.
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High-gain materials and high-quality structures are the two main conditions that determine the amplification performance of optical waveguides. However, it has been hard to balance each other, to date. In this work, we demonstrate breakthroughs in both glass optical gain and optical waveguide structures. We propose a secondary melting dehydration technique that prepares high-quality Er3+-Yb3+ co-doped phosphate glass with low absorption loss. Additionally, we propose a femtosecond laser direct-writing technique that allows controlling the cross section, size, and mode field of waveguides written in glass with high accuracy, leveraging submicron-resolution multi-scan direct-writing optical waveguide technology, which is beneficial for reducing insertion loss. As a proof of concept demonstration, we designed and fabricated two kinds of waveguides, namely, LP01- and LP11-mode waveguides in the Er3+-Yb3+ co-doped phosphate glass, enabling insertion loss as low as 0.9â dB for a waveguide length of 2 mm. Remarkably, we successfully achieved an optical amplification for both the waveguides with a net gain of >7â dB and a net-gain coefficient of >3.5â dB/mm, which is approximately one order of magnitude larger than that in the Er3+-Yb3+ co-doped phosphate glass fabricated by the traditional melt-quenching method. This will open new avenues toward the development of integrated photonic chips.
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BACKGROUND: Vascular growth followed by vessel specification is crucial for the establishment of a hierarchical blood vascular network. We have shown that TIE2 is required for vein development while little is known about its homologue TIE1 (tyrosine kinase with immunoglobulin-like and EGF [epithelial growth factor]-like domains 1) in this process. METHODS: We analyzed functions of TIE1 as well as its synergy with TIE2 in the regulation of vein formation by employing genetic mouse models targeting Tie1, Tek, and Nr2f2, together with in vitro cultured endothelial cells to decipher the underlying mechanism. RESULTS: Cardinal vein growth appeared normal in TIE1-deficient mice, whereas TIE2 deficiency altered the identity of cardinal vein endothelial cells with the aberrant expression of DLL4 (delta-like canonical Notch ligand 4). Interestingly, the growth of cutaneous veins, which was initiated at approximately embryonic day 13.5, was retarded in mice lack of TIE1. TIE1 deficiency disrupted the venous integrity, displaying increased sprouting angiogenesis and vascular bleeding. Abnormal venous sprouts with defective arteriovenous alignment were also observed in the mesenteries of Tie1-deleted mice. Mechanistically, TIE1 deficiency resulted in the decreased expression of venous regulators including TIE2 and COUP-TFII (chicken ovalbumin upstream promoter transcription factor, encoded by Nr2f2, nuclear receptor subfamily 2 group F member 2) while angiogenic regulators were upregulated. The alteration of TIE2 level by TIE1 insufficiency was further confirmed by the siRNA-mediated knockdown of Tie1 in cultured endothelial cells. Interestingly, TIE2 insufficiency also reduced the expression of TIE1. Combining the endothelial deletion of Tie1 with 1 null allele of Tek resulted in a progressive increase of vein-associated angiogenesis leading to the formation of vascular tufts in retinas, whereas the loss of Tie1 alone produced a relatively mild venous defect. Furthermore, the induced deletion of endothelial Nr2f2 decreased both TIE1 and TIE2. CONCLUSIONS: Findings from this study imply that TIE1 and TIE2, together with COUP-TFII, act in a synergistic manner to restrict sprouting angiogenesis during the development of venous system.
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Receptor TIE-1 , Receptor TIE-2 , Ratones , Animales , Receptor TIE-1/genética , Receptor TIE-1/metabolismo , Receptor TIE-2/genética , Receptor TIE-2/metabolismo , Células Endoteliales/metabolismo , Transducción de Señal , VenasRESUMEN
INTRODUCTION AND OBJECTIVES: This research aims to evaluate the efficacy and safety of prophylactic antibiotics in patients with alcohol-related liver disease (ALD). MATERIALS AND METHODS: We systematically searched databases including PubMed, Embase, Cochrane, and Web of Science up to October 2023. Our scope encompassed the influence of prophylactic antibiotics on all-cause mortality, infection, variceal bleeding, hepatic encephalopathy (HE), hepatorenal syndrome (HRS), adverse events (AE), fungal infection, clostridioides difficile infection (CDI), and multidrug-resistant (MDR) bacterial infection. Additionally, total bilirubin, creatinine, platelet counts, and plasma endotoxin levels were also analyzed. RESULTS: After comprehensive selection, 10 studies with 974 participants were included for further analysis. The study demonstrated that prophylactic antibiotic therapy was associated with reductions in infection rates, HE incidence, variceal bleeding, and all-cause mortality. The treatment did not increase the incidence of AE, fungal infection, and CDI, but it did raise the MDR bacteria infection rate. The analysis revealed no significant protective effect of antibiotic prophylaxis on total bilirubin and creatinine levels. Furthermore, the administration of antibiotics led to marginal increases in platelet counts, a minor reduction in endotoxin concentrations, and a subtle enhancement in HRS; however, these changes did not reach statistical significance. CONCLUSIONS: Prophylactic antibiotic therapy was an effective and safe treatment for advanced ALD. To mitigate the risk of MDR bacterial infections, a strategy of selective intestinal decontamination could be advisable. Future investigations should prioritize varied ALD patient populations with extended follow-up periods and assorted antibiotic regimens to solidify the efficacy and safety of ALD treatments.
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Precision medicine in oncology leverages clinical observations of exceptional response. Toward an understanding of the molecular features that define this response, we applied an integrated, multiplatform analysis of RNA profiles derived from clinically annotated glioblastoma samples. This analysis suggested that specimens from exceptional responders are characterized by decreased accumulation of microglia/macrophages in the glioblastoma microenvironment. Glioblastoma-associated microglia/macrophages secreted interleukin 11 (IL11) to activate STAT3-MYC signaling in glioblastoma cells. This signaling induced stem cell states that confer enhanced tumorigenicity and resistance to the standard-of-care chemotherapy, temozolomide (TMZ). Targeting a myeloid cell restricted an isoform of phosphoinositide-3-kinase, phosphoinositide-3-kinase gamma isoform (PI3Kγ), by pharmacologic inhibition or genetic inactivation disrupted this signaling axis by reducing microglia/macrophage-associated IL11 secretion in the tumor microenvironment. Mirroring the clinical outcomes of exceptional responders, PI3Kγ inhibition synergistically enhanced the anti-neoplastic effects of TMZ in orthotopic murine glioblastoma models. Moreover, inhibition or genetic inactivation of PI3Kγ in murine glioblastoma models recapitulated expression profiles observed in clinical specimens isolated from exceptional responders. Our results suggest key contributions from tumor-associated microglia/macrophages in exceptional responses and highlight the translational potential for PI3Kγ inhibition as a glioblastoma therapy.
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Glioblastoma/metabolismo , Microglía/metabolismo , Temozolomida/farmacología , Adulto , Animales , Neoplasias Encefálicas/patología , Línea Celular Tumoral , Fosfatidilinositol 3-Quinasa Clase Ib/metabolismo , Resistencia a Antineoplásicos/fisiología , Femenino , Glioblastoma/tratamiento farmacológico , Glioblastoma/patología , Humanos , Interleucina-11/inmunología , Interleucina-11/metabolismo , Masculino , Ratones Endogámicos C57BL , Ratones Desnudos , Microglía/fisiología , Fosfatidilinositol 3-Quinasa/metabolismo , Inhibidores de las Quinasa Fosfoinosítidos-3/farmacología , Transducción de Señal/efectos de los fármacos , Temozolomida/metabolismo , Microambiente Tumoral/efectos de los fármacos , Macrófagos Asociados a Tumores/metabolismo , Macrófagos Asociados a Tumores/fisiologíaRESUMEN
Amino acids are the building blocks of proteins and are widely used as important ingredients for other nitrogen-containing molecules. Here, we report the sustainable production of amino acids from biomass-derived hydroxy acids with high activity under visible-light irradiation and mild conditions, using atomic ruthenium-promoted cadmium sulfide (Ru1/CdS). On a metal basis, the optimized Ru1/CdS exhibits a maximal alanine formation rate of 26.0â molAla â gRu -1 â h-1, which is 1.7â times and more than two orders of magnitude higher than that of its nanoparticle counterpart and the conventional thermocatalytic process, respectively. Integrated spectroscopic analysis and density functional theory calculations attribute the high performance of Ru1/CdS to the facilitated charge separation and O-H bond dissociation of the α-hydroxy group, here of lactic acid. The operando nuclear magnetic resonance further infers a unique "double activation" mechanism of both the CH-OH and CH3-CH-OH structures in lactic acid, which significantly accelerates its photocatalytic amination toward alanine.
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Aminoácidos , Biomasa , Compuestos de Cadmio , Rutenio , Sulfuros , Sulfuros/química , Rutenio/química , Compuestos de Cadmio/química , Catálisis , Aminoácidos/química , Procesos Fotoquímicos , Teoría Funcional de la Densidad , LuzRESUMEN
Inscription of fiber-compatible active waveguides in high-gain glass, followed by direct interconnection with few-mode fibers, is one of the most promising solutions for all-optical mode-division multiplexing. In this work, based on the femtosecond laser writing technique, we propose a general fabrication scheme for inscribing high-order mode waveguides in glass, by carefully tailoring the cross-section of the waveguides to match the mode intensity distribution via an improved multi-scan approach. Specifically, we design and fabricate two kinds of waveguides, namely, LP01-mode waveguide and LP11-mode waveguide in a highly Er3+-doped phosphate glass, enabling the insertion loss of the waveguides to be as low as 1.88â dB, and the mode extraction factor of the LP11-mode waveguide up to â¼24â dB. Importantly, we have successfully achieved optical amplification of the waveguides, with an on-off gain as high as 3.52â dB. This novel high-order mode waveguide amplifier has broad application prospects in monolithic on-chip integrated photonic light sources and optical interconnection with few-mode fiber and/or silicon-based waveguide.
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The bandwidth is one of the key indicators of the interferometric fiber optic gyroscope (I-FOG) in the application with high frequency jitter. The traditional bandwidth measurement equipment, such as the angular vibration table, can only provide angular vibrations of hundreds of hertz and cannot meet the measurement needs of a high bandwidth gyro. We propose an approach, with which a signal of several thousand hertz can be provided and can measure a high bandwidth of I-FOGs. The bandwidth measurement approach is based on the axial magnetic sensitivity. We present the measurement principle, derive the axial magnetic sensitivity expression of the fiber coil in I-FOGs, and demonstrate the bandwidth measuring system. With this system, the bandwidth of an I-FOG is measured and the experimental result shows that the bandwidth is â¼10 kHz. It is proved that this new, to the best of our knowledge, approach is capable of testing the bandwidth of the I-FOG at ultrahigh frequencies.
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BACKGROUND: The purpose of this research was to evaluate the safety and efficacy of a self-expandable metallic stent (SEMS) combined with iodine-125 (125I) seeds in the treatment of Bismuth type I or II malignant biliary obstruction (MBO). METHODS: The clinical data of 74 cases of MBO treated with percutaneous SEMS combined with 125I seeds (combination group) and 81 cases of MBO treated with SEMS implantation alone (control group) in our hospital from January 2015 to December 2019 were retrospectively analyzed. The short-term and long-term efficacy of the two groups were compared. Multivariate Cox regression analysis was used to analyze the factors affecting the surgical efficacy and survival rate. RESULTS: The liver blood test results of both groups improved at one week and one month post-stent insertion. No significant difference was established in the short-term efficacy or complications between the two groups (P = NS). Improved stent patency was observed in the combined group, 9.01 ± 4.38 months versus 6.79 ± 3.13 months, respectively (P < 0.001). Improved survival was also noted in the combined group 12.08 ± 5.38 months and 9.10 ± 4.16 months, respectively (P < 0.001). Univariate and multivariate analyses showed that the type of biliary stent and liver metastasis were independent factors affecting survival. CONCLUSION: The implementation of SEMS combined with 125I seeds resulted in significantly longer stent patency and survival times than that of SEMS implantation alone, which is thus worthy of clinical promotion and application.
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Colestasis , Stents Metálicos Autoexpandibles , Humanos , Bismuto , Colestasis/etiología , Colestasis/cirugía , Estudios Retrospectivos , Resultado del Tratamiento , Stents Metálicos Autoexpandibles/efectos adversos , Stents/efectos adversosRESUMEN
OBJECTIVES: To provide a quantitative synthesis of studies on the relationship between vision impairment (VI) and cognitive outcomes in older adults. METHOD: A systematic search was undertaken of relevant databases for original articles published before April 2020. Random effect models were used to obtain pooled estimates of the associations between VI and cognitive outcomes (cognitive impairment and dementia) with subgroup analyses of VI measures, cross-sectional associations of VI with cognitive impairment, and longitudinal associations of baseline VI with incident cognitive impairment and dementia. Potential sources of heterogeneity were explored by meta-regression. Publication bias was evaluated with Egger's test. RESULTS: Sixteen studies including 76,373 participants were included in this meta-analysis, with five cross-sectional studies and eleven longitudinal studies. There was a significantly increased risk of cognitive outcomes with VI identified by subjective measures (odds ratio (OR)=1.63; 95% confidence interval (CI): 1.26-1.99) and objective measures (OR = 1.59; 95% CI: 1.40-1.78). The odds of baseline cognitive impairment were 137% higher in older adults with VI compared with those without VI (OR = 2.37, 95% CI: 1.84-3.03) at baseline. Compared with older adults without VI at baseline, those with baseline VI had a higher relative risk (RR) of incident cognitive impairment (RR = 1.41; 95% CI: 1.31-1.51) and dementia (RR = 1.44, 95% CI: 1.19-1.75). CONCLUSIONS: VI was associated with increased risks of cognitive impairment and dementia across cross-sectional and longitudinal studies. Additional research and randomized clinical trials are warranted to examine the implications of treatment for VI, such as wearing glasses and cataract surgery, to avoid cognitive impairment and dementia.
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Disfunción Cognitiva , Demencia , Humanos , Anciano , Estudios Transversales , Disfunción Cognitiva/epidemiología , Disfunción Cognitiva/complicaciones , Riesgo , Demencia/epidemiología , Demencia/complicaciones , CogniciónRESUMEN
Importance: Olamkicept, a soluble gp130-Fc-fusion-protein, selectively inhibits interleukin 6 (IL-6) trans-signaling by binding the soluble IL-6 receptor/IL-6 complex. It has anti-inflammatory activities in inflammatory murine models without immune suppression. Objective: To assess the effect of olamkicept as induction therapy in patients with active ulcerative colitis. Design, Setting, and Participants: Randomized, double-blind, placebo-controlled phase 2 trial of olamkicept in 91 adults with active ulcerative colitis (full Mayo score ≥5, rectal bleeding score ≥1, endoscopy score ≥2) and an inadequate response to conventional therapy. The study was conducted at 22 clinical study sites in East Asia. Patients were recruited beginning in February 2018. Final follow-up occurred in December 2020. Interventions: Eligible patients were randomized 1:1:1 to receive a biweekly intravenous infusion of olamkicept 600 mg (n = 30) or 300 mg (n = 31) or placebo (n = 30) for 12 weeks. Main Outcomes and Measures: The primary end point was clinical response at week 12 (defined as ≥3 and ≥30% decrease from baseline total Mayo score; range, 0-12 [worst] with ≥1 decrease and ≤1 in rectal bleeding [range, 0-3 {worst}]). There were 25 secondary efficacy outcomes, including clinical remission and mucosal healing at week 12. Results: Ninety-one patients (mean age, 41 years; 25 women [27.5%]) were randomized; 79 (86.8%) completed the trial. At week 12, more patients receiving olamkicept 600 mg (17/29 [58.6%]) or 300 mg (13/30 [43.3%]) achieved clinical response than placebo (10/29 [34.5%]), with adjusted difference vs placebo of 26.6% (90% CI, 6.2% to 47.1%; P = .03) for 600 mg and 8.3% (90% CI, -12.6% to 29.1%; P = .52) for 300 mg. Among patients randomized to receive 600 mg olamkicept, 16 of 25 secondary outcomes were statistically significant compared with placebo. Among patients randomized to receive 300 mg, 6 of 25 secondary outcomes were statistically significant compared with placebo. Treatment-related adverse events occurred in 53.3% (16/30) of patients receiving 600 mg olamkicept, 58.1% (18/31) receiving 300 mg olamkicept, and 50% (15/30) receiving placebo. The most common drug-related adverse events were bilirubin presence in the urine, hyperuricemia, and increased aspartate aminotransferase levels, and all were more common in the olamkicept groups compared with placebo. Conclusions and Relevance: Among patients with active ulcerative colitis, biweekly infusion of olamkicept 600 mg, but not 300 mg, resulted in a greater likelihood of clinical response at 12 weeks compared with placebo. Further research is needed for replication and to assess longer-term efficacy and safety. Trial Registration: ClinicalTrials.gov Identifier: NCT03235752.
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Colitis Ulcerosa , Quimioterapia de Inducción , Proteínas Recombinantes de Fusión , Adulto , Animales , Femenino , Humanos , Ratones , Colitis Ulcerosa/complicaciones , Colitis Ulcerosa/tratamiento farmacológico , Hemorragia Gastrointestinal/etiología , Quimioterapia de Inducción/métodos , Interleucina-6/antagonistas & inhibidores , Proteínas Recombinantes de Fusión/administración & dosificación , Proteínas Recombinantes de Fusión/uso terapéutico , Masculino , Método Doble CiegoRESUMEN
Limited studies have explored novel pancreatic cancer (PC) subtypes or prognostic biomarkers based on the altered activity of relevant signaling pathway gene sets. Here, we employed non-negative matrix factorization (NMF) to identify three immune subtypes of PC based on C7 immunologic signature gene set activity in PC and normal samples. Cluster 1, the immune-inflamed subtype, showed a higher response rate to immune checkpoint blockade (ICB) and had the lowest tumor immune dysfunction and exclusion (TIDE) scores. Cluster 2, the immune-excluded subtype, exhibited strong associations with stromal activation, characterized by elevated expression levels of transforming growth factor (TGF)-ß, cell adhesion, extracellular matrix remodeling, and epithelial-to-mesenchymal transition (EMT) related genes. Cluster 3, the immune-desert subtype, displayed limited immune activity. For prognostic prediction, we developed an immune-related prognostic risk model (IRPM) based on four immune-related prognostic genes in pancreatic cancer, RHOF, CEP250, TSC1, and KIF20B. The IRPM demonstrated excellent prognostic efficacy and successful validation in an external cohort. Notably, the key gene in the prognostic model, RHOF, exerted significant influence on the proliferation, migration, and invasion of pancreatic cancer cells through in vitro experiments. Furthermore, we conducted a comprehensive analysis of somatic mutational landscapes and immune landscapes in PC patients with different IRPM risk scores. Our findings accurately stratified patients based on their immune microenvironment and predicted immunotherapy responses, offering valuable insights for clinicians in developing more targeted clinical strategies.
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Multiómica , Neoplasias Pancreáticas , Humanos , Neoplasias Pancreáticas/genética , Páncreas , Algoritmos , Adhesión Celular , Microambiente Tumoral/genética , CinesinasRESUMEN
The identification of the prognostic markers and therapeutic targets might benefit the diagnosis and treatment of pancreatic adenocarcinoma (PAAD), one of the most aggressive malignancies. Vacuolar protein sorting associated protein 26 A (VPS26A) is a candidate prognosis gene for hepatocellular carcinoma, but its expression and function in PAAD remain unknown. The mRNA and protein expression of VPS26A in PAAD was explored and validated by bioinformatics and immunohistochemical analysis. The correlation between VPS26A expression and various clinical parameters, genetic status, diagnostic and prognostic value, survival and immune infiltration were evaluated, and the co-expressed gene-set enrichment analysis for VPS26A was performed. Cytologic and molecular experiments were further carried out to investigate the role and potential mechanism of VPS26A in PAAD. The mRNA and protein levels of VPS26A were elevated in PAAD tissues. High VPS26A expression was associated with the advanced histological type, tumor stage simplified, smoking status and tumor mutational burden score, and the poor prognosis of PAAD patients. VPS26A expression was significantly correlated with immune infiltration and immunotherapy response. VPS26A-co-expressed genes were mainly enriched in the regulation of cell adhesion and actin cytoskeleton and the immune-response-regulating signaling pathway. Our experiments further demonstrated that VPS26A promoted the proliferation, migration and invasion potentials of PAAD cell lines through activating the EGFR/ERK signaling. Our study suggested that VPS26A could be a potential biomarker and a therapeutic target for PAAD through comprehensive regulation of its growth, migration and immune microenvironment.
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Adenocarcinoma , Neoplasias Hepáticas , Neoplasias Pancreáticas , Humanos , Regulación Neoplásica de la Expresión Génica , Pronóstico , Microambiente Tumoral , Neoplasias PancreáticasRESUMEN
Nonvolatile and giant modulation of luminescence can be realized by the ferroelectric gating effect in a Ga3+/Pr3+ co-doped BaTiO3 ultra-thin film epitaxially grown on a [Pb(Mg1/3Nb2/3)O3]0.7-[PbTiO3]0.3 single-crystallized substrate. The change behavior of the emission intensity matches that of the ferroelectric polarization hysteresis loop with a giant enhancement of over 13â times with negative polarization orientation. The interaction of O2- at the O2p orbital in the valence band and Pr3+ with injected holes by the ferroelectric gating effect promotes the formation of excited state O-, Pr4+, or Pr3+q. This ferroelectric gating method can promote the development of controllable photo-, electroluminescent, and other optoelectronic devices for display, sensing, communication, and so on.
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Aims: To determine the effectiveness and safety of sequential computed tomography-guided percutaneous microwave ablation (MWA) after transcatheter arterial chemoembolization (TACE) for hypovascular liver lesions <5 cm in size. Methods: The clinical data of 69 hypovascular hepatocellular carcinoma lesions <5 cm in 60 patients treated with TACE followed by MWA were retrospectively analyzed. Results: There was no significant difference in AFP levels among AFP-positive patients before and after TACE (p = 0.515), but levels were significantly lower 1 month after MWA than before MWA (p = 0.039). Compared with 1 month after TACE, the objective response rate (p < 0.001) and disease control rate (p = 0.004) were increased 1 month after MWA. Any adverse events were well tolerated, and the albumin bilirubin score did not deteriorate within 4 weeks. Conclusion: Sequential MWA after TACE was found to be safe and effective for treating hypovascular hepatocellular carcinoma for lesions <5 cm in size.
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Carcinoma Hepatocelular , Quimioembolización Terapéutica , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/patología , Neoplasias Hepáticas/patología , Microondas/efectos adversos , Estudios Retrospectivos , alfa-Fetoproteínas , Quimioembolización Terapéutica/efectos adversos , Terapia Combinada , Resultado del TratamientoRESUMEN
Solar-driven transfer hydrogenation of unsaturated bonds has received considerable attention in the research area of sustainable organic synthesis; however, water, the ultimate green source of hydrogen, has rarely been investigated due to the high barrier associated with splitting of water molecules. We report a carbon-nitride-supported palladium single-atom heterogeneous catalyst with unparalleled performance in photocatalytic water-donating transfer hydrogenation compared to its nanoparticle counterparts. Isotopic-labeling experiments and operando nuclear magnetic resonance measurements confirm the direct hydrogenation mechanism using in situ-generated protons from water splitting under visible-light irradiation. Density functional theory calculations attribute the high activity to lower barriers for hydrogenation, facilitated desorption of ethylbenzene, and facile hydrogen replenishment from water on the atomic palladium sites.
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Copper-based materials are efficient electrocatalysts for the conversion of CO2 to C2+ products, and most these materials are reconstructed in situ to regenerate active species. It is a challenge to precisely design precatalysts to obtain active sites for the CO2 reduction reaction (CO2 RR). Herein, we develop a strategy based on local sulfur doping of a Cu-based metal-organic framework precatalyst, in which the stable Cu-S motif is dispersed in the framework of HKUST-1 (S-HKUST-1). The precatalyst exhibits a high ethylene selectivity in an H-type cell with a maximum faradaic efficiency (FE) of 60.0 %, and delivers a current density of 400â mA cm-2 with an ethylene FE up to 57.2 % in a flow cell. Operando X-ray absorption results demonstrate that Cuδ+ species stabilized by the Cu-S motif exist in S-HKUST-1 during CO2 RR. Density functional theory calculations indicate the partially oxidized Cuδ+ at the Cu/Cux Sy interface is favorable for coupling of the *CO intermediate due to the modest distance between coupling sites and optimized adsorption energy.
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Detailed information about the influences of the cooperative motion of water and methanol molecules on practical solid-liquid heterogeneous photocatalysis reactions is critical for our understanding of photocatalytic reactions. The present work addresses this issue by applying operando nuclear magnetic resonance (NMR) spectroscopy, in conjunction with density functional theory (DFT) calculations and ab initio molecular dynamics (AIMD) simulations, to investigate the dynamic behaviors of heterogeneous photocatalytic systems with different molar ratios of water to methanol on rutile-TiO2 photocatalyst. The results demonstrate that methanol and water molecules are involved in the cooperative motions, and the cooperation often takes the form of methanol-water clusters that govern the number of methanol molecules reaching to the active sites of the photocatalyst per unit time, as confirmed by the diffusion coefficients of the methanol molecule calculated in the binary methanol-water solutions. Nuclear Overhauser effect spectroscopy experiments reveal that the clusters are formed by the hydrogen bonding between the -OH groups of CH3OH and H2O. The formation of such methanol-water clusters is likely from an energetic standpoint in low-concentration methanol, which eventually determines the yields of methanol reforming products.
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By incorporating the CsPbBr3 quantum dots (QDs) into a glass host, we report for the first time, to our knowledge, the measurement of non-resonant optical nonlinearity and multiphoton upconversion (UC) processes for this QD-in-glass composite. We observe up to four-photon stable UC photoluminescence under excitation by infrared femtosecond pulses, low optical limiting thresholds, and high nonlinear optical absorption coefficients close to those of colloid processed metal halide perovskite (MHP) QDs. Combined with high robustness against air and moisture, the monolithic inorganic glass with incorporated MHP QDs could be a better platform for exploiting strong light-matter interaction for MHPs.