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1.
ACS Sustain Chem Eng ; 12(5): 1868-1883, 2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-38333202

RESUMO

Amid growing concerns about climate change and energy sustainability, the need to create potent catalysts for the sequestration and conversion of CO2 to value-added chemicals is more critical than ever. This work describes the successful synthesis and profound potential of high-performance nanofiber catalysts, integrating earth-abundant iron (Fe) and cobalt (Co) as well as their alloy counterpart, FeCo, achieved through electrospinning and judicious thermal treatments. Systematic characterization using an array of advanced techniques, including SEM, TGA-DSC, ICP-MS, XRF, EDS, FTIR-ATR, XRD, and Raman spectroscopy, confirmed the integration and homogeneous distribution of Fe/Co elements in nanofibers and provided insights into their catalytic nuance. Impressively, the bimetallic FeCo nanofiber catalyst, thermally treated at 1050 °C, set a benchmark with an unparalleled CO2 conversion rate of 46.47% at atmospheric pressure and a consistent performance over a 55 h testing period at 500 °C. Additionally, this catalyst exhibited prowess in producing high-value hydrocarbons, comprising 8.01% of total products and a significant 31.37% of C2+ species. Our work offers a comprehensive and layered understanding of nanofiber catalysts, delving into their transformations, compositions, and structures under different calcination temperatures. The central themes of metal-carbon interactions, the potential advantages of bimetallic synergies, and the importance of structural defects all converge to define the catalytic performance of these nanofibers. These revelations not only deepen our understanding but also set the stage for future endeavors in designing advanced nanofiber catalysts with bespoke properties tailored for specific applications.

2.
J Clin Exp Hepatol ; 14(2): 101308, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38261889

RESUMO

Spider angiomas are dilated vascular channels in the skin. They have a central arteriole with surrounding vascular channels resembling legs of a spider, hence the name. They are frequently associated with liver cirrhosis, thyrotoxicosis, and pregnancy. We present the case of a 49-year-old gentleman who was referred to our liver clinic with complaints of jaundice and ascites of one-month duration. The patient was a chronic alcohol consumer, consuming country-made liquor, 80-100 grams/day for past 8-10 years. He was diagnosed with Acute on chronic liver failure with a model for end-stage liver disease score of 38. During his hospital stay, he developed active spurting from a spider angioma on his lower lip (video 1), which was initially tackled with hand compressions, which stopped bleeding for a few minutes, restarting again after the compressions were lifted. It was then decided to inject 0.1 mL cyanoacrylate glue injection using a 21-gauge needle, immediately stopping active spurt (video 2), (Figure 1). A small ulcer formed at the injection site, which healed in few days, and the patient was discharged to home. Spider angiomas are characteristic cutaneous manifestation of liver cirrhosis with a specificity of 95%.1 The prevalence of spider angiomas in cirrhosis is reported to be around 30-40%. Li Hongyu et al. in their study on 198 individuals reported the prevalence to be 47%.2 They can be graded from grade 1+ (readily recognizable containing a body, legs, and surrounding erythema) to grade 4+ (visible pulsations with a hand lens and raised central punctum with many obvious "spider legs" radiating from it).3 Underlying pathogenesis in cirrhosis is multifactorial including decrease levels of testosterone and high levels of estradiol,4 hyperdynamic circulation, high levels of substance-P, and vascular endothelial growth factor leading to angiogenesis and vasodilation.5,6 Spider angiomas can be single or multiple and are usually seen in the territory of superior vena cava-the face (nose, lips, forehead), upper chest, and arms.2 These lesions have been associated with bleeding esophageal varices and hepatopulmonary syndrome. Bleeding from spider angiomas is unusual. Rarely, fine-needle electrocautery, potassium-titanyl-phosphate (KTP) laser, or electro desiccation has been used to clear spider angiomas for cosmetic concerns. Treatment includes hand or ice compressions and treating the underlying cause. Use of cyanoacrylate glue for bleeding spider angioma has not been reported in the literature. We think this can be a handy bedside tool to combat an active spurt of bleeding when conventional methods have failed, as in our case; however, further studies are warranted.

3.
Dig Dis Sci ; 68(2): 497-513, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-35984611

RESUMO

BACKGROUND: Hyperfibrinolysis and coagulation dysfunction may occur in cirrhotic patients with acute variceal bleed (AVB) despite successful endotherapy. AIMS: To prospectively study the association of endogenous heparinoids and coagulation dysfunction with variceal rebleeding and outcome in cirrhosis. METHODS: Consecutive patients were assessed with conventional coagulation tests, SONOCLOT™ [(global(gb) and heparinase(h) treated] and factors VII, VIII, XIII, X, tissue plasminogen activator, and plasminogen activator inhibitor ELISA assays in a university hospital. Heparin-like-effect (HLE) was defined as ≥ 20% difference in paired gb/h-SONOCLOT™ traces for activated clotting time (ACT). RESULTS: Of 143 patients screened, 90 (46.4 ± 11.7 years, males 82.2%, ethanol-related 58.8%) were recruited, who bled from esophageal varices (81,90.0%), gastric varices (6,6.6%), or esophageal varices with portal hypertensive gastropathy (3,3.3%). Twenty (21.7%) had early rebleeding, mainly post-variceal ligation ulcer related (70%). Patients who rebled had low Factor XIII [1.6 (1.2-2.1) vs 2.4 ng/ml (2.0-2.8) P = 0.035] and Factor VII (94.1 ± 46.9 vs. 124.0 ± 50.4, P = 0.023). On receiver operating curve analysis, the gbACT > 252 s (sensitivity 86.8%, specificity 76.9%, P < 0.001), hACT > 215 s (sensitivity 71.1%, specificity 70.3%, P < 0.001), and HLE > 50% (sensitivity 69.5%, specificity 70.3%, P = 0.006) predicted rebleeding. Baseline Factor VIII (HR 1.26; 95% CI 1.17-1.34, P < 0.001), low factor VII (HR 0.89; 95% CI 0.76-0.98, P = 0.035), and lysis (HR 1.25, 95% CI 1.17-1.33, P < 0.001) predicted mortality. Endogenous heparinoids at baseline predicted sepsis (HR 1.8; 95% CI 1.4-6.5; P = 0.022), rebleeding events (HR 1.2; 95% CI 1.1-6.3; P = 0.030), and mortality (HR 1.1; 95% CI 1.0-4.6; P = 0.030). CONCLUSIONS: Hyperfibrinolysis, Factor VII/XIII deficiency, and HLE are associated with rebleeding after AVB. Trial Registration NCT04111120 available from https://clinicaltrials.gov/ct2/show/NCT04111120 .


Assuntos
Varizes Esofágicas e Gástricas , Heparinoides , Masculino , Humanos , Varizes Esofágicas e Gástricas/etiologia , Fator VII , Ativador de Plasminogênio Tecidual , Hemorragia Gastrointestinal/etiologia , Heparina , Fibrinólise , Cirrose Hepática/complicações , Ligadura/efeitos adversos
4.
J Clin Exp Hepatol ; 12(3): 1007-1011, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34898957

RESUMO

Liver transplant recipients are at an increased risk of opportunistic infections due to the use of immunosuppression. Coronavirus disease of 2019 (COVID-19) increases the risk of these infections further due to associated immune dysfunction and the use of high-dose steroids. We present a case of a liver transplant recipient who developed disseminated tuberculosis and invasive pulmonary aspergillosis complicated by acquired hemophagocytic lymphohistiocytosis after recovering from severe COVID-19.

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