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The electrochemical CO2 reduction reaction (CO2RR) is an appealing method for carbon utilization. Alkaline CO2 electrolyzers exhibit high CO2RR activity, low full-cell voltages, and cost-effectiveness. However, the issue of CO2 loss caused by (bi)carbonate formation leads to excessive energy consumption, rendering the process economically impractical. In this study, we propose a trilayer polymer electrolyte (TPE) comprising a perforated anion exchange membrane (PAEM) and a bipolar membrane (BPM) to facilitate alkaline CO2RR. This TPE enables the coexistence of high alkalinity near the catalyst surface and the H+ flux at the interface between the PAEM and the cation exchange layer (CEL) of the BPM, conditions favoring both CO2 reduction to multicarbon products and (bi)carbonate removal in KOH-fed membrane electrode assembly (MEA) reactors. As a result, we achieve a Faradaic efficiency (FE) of approximately 46 % for C2H4, corresponding to a C2+ FE of 64 % at 260â mA cm-2, with a CO2-to-C2H4 single-pass conversion (SPC) of approximately 32 % at 140â mA cm-2-nearly 1.3â times the limiting SPC in conventional AEM-MEA electrolyzers. Furthermore, coupling CO2 reduction with formaldehyde oxidation reaction (FOR) in the TPE-MEA electrolyzer reduces the full-cell voltage to 2.3â V at 100â mA cm-2 without compromising the C2H4 FE.
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Molecular manipulation of guanidino-containing biomolecules in a cellular environment is fundamental to exploiting protein function and drug release, but currently, there is a lack of suitable methods for reaction screening and monitoring. To exploit the potential of the fluorescent method in this respect, herein, we evaluated a novel array of 7-guanidinyl coumarins by incorporating different substituted guanidino moieties into a coumarin scaffold. These compounds were prepared by guanidinylation reagent S-methylisothiourea or TFA-protected pyrazole-carboxamidine. Examination of their photophysical properties revealed that the fluorescence emission of alkyloxycarbonyl-substituted guanidinyl coumarin was significantly enhanced as compared with the unsubstituted analogue. This dramatic fluorescence difference enabled preliminary exploitation of the Pd-catalyzed release of allyloxycarbonyl (Alloc)-caged guanidinyl coumarin-6 in living cells.
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Guanidinas , Paládio , Guanidina , Fluorescência , CumarínicosRESUMO
Efficient access to S-methyl dithiocarbamates was achieved with sulfonium or sulfoxonium iodide as a methylation reagent. This method is reliable for the synthesis of dithiocarbamates from primary or secondary amines, with sulfoxonium iodide demonstrating more robust methylation capability than sulfonium iodide. Moreover, it also enables facile access to S-trideuteromethyl dithiocarbamates via sulfoxonium metathesis between sulfoxonium iodide and DMSO-d6 with high yields.
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A convergent access to substituted 2-iminoimidazolidines from aromatic amines and N-propargyl S-methylthiourea is developed via Ag(I)-mediated cascade guanylation-cyclization reactions. This method features high regioselectivity, excellent efficiency, and mild reaction conditions. Subsequent deprotection of the Boc (tert-butyloxycarbonyl) group under acidic conditions provides expedient access to aryl 2-aminoimidazole derivatives in a convenient manner.
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Aminas , Ciclização , Estrutura MolecularRESUMO
An Ag(i)-catalyzed tandem addition-cyclization of isothiocyanate and propargylamine was successfully applied to the synthesis of 2-amino-4-methylenethiazolines. This route features an unprecedented fast reaction rate with full conversion reached within 10 min at room temperature for aromatic isothiocyanates and excellent chemoselectivity for exocyclic products. The application of this strategy is further highlighted by the accelerated bioconjugation of propargylamine with fluorescein isothiocyanate (FITC) under Ag(i)-catalysis.
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Pargilina/análogos & derivados , PropilaminasRESUMO
Low-temperature electroreduction of CO2 and CO (CO(2)RR) into valuable chemicals and fuels offers a promising pathway to reduce greenhouse gas emissions and achieve carbon neutrality. Today's low-temperature CO(2)RR technology relies on the use of ionomers, polymers with ionized groups, primarily as catalyst layer (CL) additives. In the meantime, ionomers can assemble into ion-exchange membranes (IEMs), serving as important components of electrolyzers. According to the ion-exchange functions, ionomer additives are classified as cation-exchange ionomers (CEIs) and anion-exchange ionomers (AEIs); similarly, IEMs are divided into cation-exchange membranes (CEMs) and anion-exchange membranes (AEMs), as well as the multilayer polymer electrolytes (MPEs). Recent studies show that ionomer additives can regulate the catalytic microenvironment and thereby enhance performance towards desired products. This Review discusses the roles of ionomer additives and IEMs in CO2 and CO reduction reactions, highlighting the latest mechanistic insights and performance advances. It outlines challenges in designing ionomer additives and IEMs to improve product selectivity, energy efficiency (EE), and operational lifetime of CO(2)RR electrolyzers, while also providing perspectives on future research directions. The aim is to connect the current status of ionomer and membrane development with performance metrics analysis, offering insights for the advancement of commercially relevant low-temperature CO(2)RR electrolyzers.
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Two new compounds, 7-hydroxy-5-methoxy-4,6-dimethyl-7-O-α-L-rhamnosyl-phthalide and 7-hydroxy-5-methoxy-4,6-dimethyl-7-O-ß-D-glucopyranosyl-phthalide, along with one known and related metabolite 7-hydroxy-5-methoxy-4,6-dimethylphthalide were isolated from the EtOAc extract of fermentation broth of an endophytic fungus Pestalotiopsis heterocornis. The structures of these compounds were elucidated on the basis of spectroscopic methods (UV, IR, HR-ESI-MS, 1D NMR, and 2D NMR).
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Benzofuranos/isolamento & purificação , Glicosídeos/isolamento & purificação , Xylariales/química , Benzofuranos/química , Glicosídeos/química , Estrutura Molecular , Ressonância Magnética Nuclear BiomolecularRESUMO
Objective: To explore the effectiveness and safety of rituximab (RTX) for steroid-dependent or frequently relapsing nephrotic syndrome via a systematic review and meta-analysis. Methods: All the literature about RTX therapy for childhood nephrotic syndrome (NS) on PubMed, Web of Science, Cochrane Library, EMBASE, and Chinese biomedical literature database published before November 1, 2019, were conducted and selected according to the preset criteria. The Cochrane bias risk assessment tool was used to evaluate the quality of the literature included. The outcome data were analyzed by RevMan 5.3 software. Results: There were six RCT studies that met the inclusion criteria with a moderate quality after evaluation. At the end of the treatment, the relapse rate of NS in the RTX group reduced significantly when compared with that in the control group [odds ratio (OR) = 0.11, 95% confidence interval (CI) (0.03, 0.43), p = 0.001]. The number of patients in the RTX group used less steroid or/and calcineurin inhibitors significantly than that in the control group [OR = 0.05, 95% CI (0.01, 0.28), p = 0.0007]. For children who were steroid-dependent, RTX treatment significantly reduced the dosage of the steroid, compared with that in control [standardized mean difference (SMD) = -1.49, 95% CI (-2.00, -0.99), p < 0.00001]. There was no significant reduction in protein excretion between the two groups [SMD = -0.33, 95% CI (-0.71, 0.04), p = 0.08]. Fewer serious adverse reactions of RTX in the six studies were reported and most adverse events were mild. Conclusion: RTX is effective and safe for children with steroid-dependent or frequently relapsing nephrotic syndrome. Systematic Review Registration: Identifier: CRD 42020150933. https://www.crd.york.ac.uk/prospero/. This review has been registered to the PROSPERO on 27 Feb 2020.
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OBJECTIVE: To investigate the clinical characteristics of childhood antineutrophil cytoplasmic autoantibody (ANCA)-associated rapidly progressive glomerulonephritis. METHODS: The medical data, including clinical manifestations, laboratory findings, and kidney pathology, of 7 children with ANCA-associated rapidly progressive glomerulonephritis were retrospectively studied. RESULTS: The 7 patients (6 girls and 1 boy) ranged in age from 3.5-14 years, with a mean age of 9 years. A diversity of major complaints and clinical symptoms was presented in the patients. Laboratory findings were not specific. All patients had elevated ESR, BUN and serum creatinine levels as well as anaemia, hematuria and proteinuria. Urinary protein electrophoresis showed mixed proteinuria in the 7 cases. C3 was normal in 3 cases and slightly decreased in 4 cases. All were MPO-ANCA positive, and 1 out of the 7 cases was positive for PR3-ANCA. Renal biopsy displayed extensive crescentic formations and necrotic glomerulus capillary loop. A great quantity of inflammatory cell infiltration and swollen endotheliocytes of small vessels as well as vessel wall edema or necrosis were found in the interstitium. Immunofluorescence showed no or little amounts of immune complex depositions in the renal glomeruli and vessel walls. Renal function was recovered and hematuria/proteinuria disappeared or greatly relieved in 3 patients after methylprednisone and cyclophosphamide pulse therapy. CONCLUSIONS: Children with ANCA-positive rapidly progressive glomerulonephritis present with various clinical manifestations. The diagnosis of this disorder may be difficult due to a lack of specificity in its clinical manifestations. It is important to enhance our understanding of this disorder to effectively make an early diagnosis.
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Anticorpos Anticitoplasma de Neutrófilos/análise , Glomerulonefrite/imunologia , Adolescente , Biópsia , Criança , Pré-Escolar , Progressão da Doença , Feminino , Glomerulonefrite/tratamento farmacológico , Glomerulonefrite/patologia , Humanos , Rim/patologia , Masculino , Prednisona/uso terapêuticoRESUMO
AIM: To investigate the intestine and body development of intrauterine growth retardation (IUGR) rats under early different protein diet and to analyze the correlation between leptin and intestine and body development. METHODS: An IUGR rat model was established by food restriction of pregnant female rats. Fifty-six neonatal IUGR rats and 24 neonatal normal rats were randomly divided into normal control group (C group), IUGR model group (SC group), low protein diet IUGR group (SL group), and high protein diet IUGR group (SH group). Eight rats were killed per group at wk 0, 4, and 12. Serum leptin, body weight (BW), body length (BL), intestinal weight (IW), intestinal length (IL), and intestinal disaccharidase (including lactase, maltase, and saccharase) were detected. RESULTS: BW (4.50+/-0.41 g), BL (5.96+/-0.40 cm), IW (0.05+/-0.01 g), and IL (15.9+/-2.8 cm) in neonatal IUGR rats were much lower than those in C group (6.01+/-0.55 g, 6.26+/-0.44 cm, 0.10+/-0.02 g, 21.8+/-2.7 cm, P<0.05), while intestinal lactase and maltase activities were higher than those in C group. SH group showed the fastest catch up growth and their BW, BL, IW, and IL reached the C group level at wk 4. SC group showed relatively slower catch up growth than SH group, and their BW, BL, IW did not reach the C group level at wk 4. SL group did not show intestine and body catch up growth. Intestinal maltase (344+/-33 micromol/(min.g)) and saccharase activities (138+/-32 micromol/(min.g)) in SL group were both markedly lower than those in C group (751+/-102, 258+/-27 micromol/(min.g), P<0.05). There were no significant differences in lactase activities at wk 4 and disaccharidase activities at wk 12 among all groups (P>0.05). The leptin level in SL group (0.58+/-0.12 ng/mL) was the highest in all groups, and much lower in SH group (0.21+/-0.03 ng/mL) than that in any other IUGR groups at wk 4 (P<0.05). Leptin was negatively related to BW (r = -0.556, P = 0.001), IW (r = -0.692, P = 0.001) and IL (r = -0.738, P = 0.000) at wk 4, while no correlation was found at wk 12. CONCLUSION: High protein diet is a reasonable early nutritional mode to IUGR rats in promoting intestine and body catch up growth.
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Retardo do Crescimento Fetal/dietoterapia , Retardo do Crescimento Fetal/fisiopatologia , Transtornos da Nutrição Fetal/dietoterapia , Transtornos da Nutrição Fetal/fisiopatologia , Intestinos/embriologia , Leptina/sangue , Animais , Proteínas Alimentares/farmacologia , Modelos Animais de Doenças , Feminino , Retardo do Crescimento Fetal/sangue , Transtornos da Nutrição Fetal/sangue , Masculino , Gravidez , Ratos , Ratos Sprague-DawleyRESUMO
OBJECTIVE: To investigate the effects of early nutritional intervention on the serum insulin-like growth factor-1 (IGF1), insulin-like growth factor binding protein 3 (IGFBP3), intestinal development, and catch-up growth of intrauterine growth retardation (IUGR) rats by giving the IUGR new born rats different protein level diet. METHODS: IUGR rat model was built by starvation of pregnant female rats. Twenty-four IUGR pups and 8 normal pups were divided randomly into 4 groups: normal control group (C group); IUGR control group (S group), IUGR low-protein diet group (SL group), and IUGR high-protein diet group (SH group). Detected the serum IGF1, IGFBP3, body weight, body length, intestinal weight length, intestinal villi height (VH), crypt depth (CD), villi absorbing area (VSA), mucous thickness (MT), and disaccharidase at the 4th week. RESULTS: (1) The SH group showed the fastest catch-up growth, serum IGF1, IGFBP3, VH, and VSA were significantly higher than those of normal control group and IUGR control group. The intestinal weight and length, and the activities of lactase and saccharase of the SH group also reached the normal control group level. (2) The SL group kept on small size, the serum IGF1, IGFBP3, and most of intestinal histological indexes were all significantly lower than other groups. (3) IGF1, IGFBP3 were positively correlated to intestinal VH, VSA, saccharase, body weight and length. CONCLUSIONS: The serum IGF1 was a sensitive index to the catch-up growth. The early nutritional intervention of high-protein diet after birth is helpful for the catch-up growth of IUGR through promoting the intestinal development and the absorption of nutrition.
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Animais Recém-Nascidos/crescimento & desenvolvimento , Proteínas Alimentares/farmacologia , Retardo do Crescimento Fetal/sangue , Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina/sangue , Fator de Crescimento Insulin-Like I/metabolismo , Fenômenos Fisiológicos da Nutrição , Animais , Peso Corporal/efeitos dos fármacos , Feminino , Retardo do Crescimento Fetal/etiologia , Intestinos/crescimento & desenvolvimento , Intestinos/patologia , Gravidez , Distribuição Aleatória , Ratos , Ratos Sprague-DawleyAssuntos
Fluoracetatos/intoxicação , Hemoperfusão , Criança , Pré-Escolar , Feminino , Humanos , Lactente , MasculinoRESUMO
OBJECTIVE: In the past the mortality and sequelae rate of the patients with severe fluoroacetamide (FAM) poisoning treated only with traditional remedies was high. During the recent ten years the authors treated children with severe FAM poisoning with charcoal hemoperfusion (HP) and achieved better results. However evidence was not sufficient to show that reduced mortality and sequelae rates were obtained from HP without traditional treatment because of lack of prospective randomized, controlled clinical studies. Thus, a dog model for FAM poisoning was designed in order to study the therapeutic effect, high-efficiency time of HP, the time of tissue-poisoning to release after HP, and to investigate the toxicokinetics of the poison in the course of treatment and after HP. METHOD: Fourteen dogs were given intraperitoneal FAM at a dose of 0.3 mg/kg body weight. HP was performed on 9 poisoned dogs for 30 - 120 minutes post intoxication. Each procedure lasted for 4 hours. Blood samples of the 9 poisoned dogs were collected before HP and 30, 60, 90, 120, 180, 240 minutes during HP and 2, 6, 24 hours after HP. Blood plasma was separated from blood samples and stored at -20 degrees C. The concentration of the poison was measured by gas chromatography (GC). The clinical symptoms of all the dogs were observed for one day. RESULTS: The FAM concentration (ng/ml) of blood samples in poisoned dogs before HP, and 60, 120, 180, 240 minutes during HP were 230.11 +/- 52.48, 184.56 +/- 62.57, 141.00 +/- 44.83, 126.78 +/- 61.04, 113.11 +/- 54.65 respectively. The differences were significant (chi(2) = 31.978, P < 0.0005). The dispersion count between pre-HP and HP for 1 was 45.55, between 1 h and 2 h was 43.56, between 2 h and 3 h was 14.22 and between 3 h and 4 h was 13.67. The values of FAM had declined by 38.7%, 45.0% and 50.8% respectively at 2 h, 3 h, 4 h of HP compared with pre-HP. The rate of cleaning efficacy of FAM of every hour during HP were 19.79%, 23.6%, 10.09% and 10.78% respectively during HP 1, 2, 3, 4 h. The cleaning efficacy of HP was high within 2 hours during HP. The concentration of FAM slightly rose again 6 h after HP. The level of FAM had declined at 24 hour after HP when compared with pre-HP level. The reduction rate of FAM level for every hour during HP was higher than that after HP (12.71% vs 0.27% - 2.22%). The t(1/2) of FAM with and without HP were (4.50 +/- 1.20) h and (49.60 +/- 10.56) h. All the 5 poisoned dogs not treated with HP died. However 6 poisoned dogs treated with HP kept alive after HP. Three dogs had frequent seizures again 4h after HP. After HP the charcoal container was washed by 0.9% saline and FAM could not be detected in the douche. CONCLUSIONS: Charcoal HP was an effective treatment for severe FAM poisoning. T(1/2) of the poison was shortened, and the poison clearing rate was accelerated by HP. The high-efficiency time of HP was 2 - 2.5 h. Activated charcoal can adsorb the poison vigorously, and return of blood to the body after HP by using 0.9% saline was feasible and safe.
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Carvão Vegetal/uso terapêutico , Fluoracetatos/intoxicação , Hemoperfusão/métodos , Taxa de Depuração Metabólica , Intoxicação/terapia , Animais , Cães , Intoxicação/metabolismo , Venenos/toxicidade , Convulsões/induzido quimicamente , Resultado do TratamentoRESUMO
OBJECTIVE: About 20 - 50% individuals with intrauterine growth retardation (IUGR) could not achieve catch-up growth and remain small in size till adulthood. There are few reports on the relation between intestinal development and body catch-up growth of IUGR. Studies showed that early "nutritional programming" would results in long-term effects on the body growth and organic function, and gastrointestinal development is closely related to the body development as well. The authors aimed to study the effect of early nutritional interventions on serum IGF1, IGFBP3, intestinal development and catch-up growth of pups with IUGR by using diets with different protein and caloric levels during the first four weeks of life. METHODS: An IUGR rat model was established by maternal nutrition restriction during pregnancy. Thirty-two IUGR female pups were divided randomly into 4 groups (8 pups in each group) and eight normal female pups as control. The groups and interventions were (1) Normal control group (C group); (2) IUGR control group (S group), (3) IUGR low-protein diet group (SL group); (4) IUGR high-protein diet group (SH group); (5) IUGR high-caloric group (SA group). The serum IGF1, IGFBP3, body weight, body length, and intestinal weight, length, intestinal villi height (VH), crypt depth (CD), villi absorbing area (VSA), mucous thickness (MT) were measured at the 4(th) week of life. RESULTS: (1) At the 4(th) week, the serum IGF1 (724.0 +/- 153.5 ng/ml), IGFBP3 (9.69 +/- 3.13 ng/ml), and VH (416.9 +/- 46.3 microm), VSA (115.9 +/- 24.0 x 10(3) microm(2)), MT (583.9 +/- 68.5 microm) in the SH group were significantly higher than those of normal control group (539.4 +/- 198.4 ng/ml, 4.77 +/- 2.98 ng/ml and 322.1 +/- 25.8 microm, 85.8 +/- 17.8 x 10(3) microm(2), 480.0 +/- 61.5 microm) and IUGR control group (P < 0.05). The intestinal weight (1.91 +/- 0.16 g) and length (80.67 +/- 9.47 cm) in the SH group was not significantly different from the normal control group (2.24 +/- 0.22 g and 74.77 +/- 9.06 cm, P > 0.05). The SH group showed the fastest catch-up growth. Their body weights (40.14 +/- 11.03 g) at the 3(rd) week and body lengths (23.61 +/- 0.49 cm) at the 4(th) week of life reached the normal ranges of the control group (44.65 +/- 5.36 g and 23.10 +/- 1.42 cm, P > 0.05). (2) The serum IGF1 (346.7 +/- 85.3 ng/ml), IGFBP3 (1.4 +/- 0.21 ng/ml), body weight (21.41 +/- 3.54 g) and body length (15.96 +/- 1.29 cm) and the most of intestinal indexes in the SL group were markedly lower than other groups at the 4(th) week of life (P < 0.05). CONCLUSION: The serum IGF1 was a sensitive marker to reflect the catch-up growth and nutritional status, and IGF1 was positively correlated with the intestinal development and body growth. When given different nutritional interventions during the first four weeks of life, high protein diet is more helpful for the IUGR catch-up growth by promoting the intestinal development and the absorption of nutrition.