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The efficient synthesis of fluoroalkylated pyrazolo[1,5-c]quinazolines by reactions of 3-diazoindolin-2-ones with methyl ß-fluoroalkylpropionates has been achieved. This protocol affords two regioisomers of fluoroalkylated pyrazolo[1,5-c]quinazolines with excellent yields in total. The dipolarophilicity of methyl ß-fluoroalkylpropionates enhanced by perfluoroalkyl groups is crucial for the high efficiency of this [3 + 2] cycloaddition reaction.
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A convenient silver-promoted radical cascade aryldifluoromethylation/cyclization of 2-allyloxybenzaldehydes has been developed. Experimental studies disclosed that the addition of aryldifluoromethyl radicals in situ produced from easily accessible gem-difluoroarylacetic acids to unactivated double bonds in 2-allyloxybenzaldehyde was an effective route to access a series of 3-aryldifluoromethyl-containing chroman-4-one derivatives in moderate to good yields under mild reaction conditions.
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To understand the current quality status and rearing situation of Bombyx Batryticatus, the authors collected 102 batches of Bombyx Batryticatus from different main producing areas and five major Chinese medicine markets from 2016 to 2018, and measured the properties and quality of the silk gland, to clarify the quality status of Bombyx Batryticatus from different producing areas and markets. In addition, 35 batches of Bombyx Batryticatus from 2019 to 2022 were used to verify the silk gland after revision. Moreover, Beauveria Bassiana was inoculated in the silkworm of 4-5 instars, and standardized rearing was carried out until they die. The death rate and the quality of Bombyx Batryticatus were measured to determine the differences in Bombyx Batryticatus of different instars, and explore the rationality of the infection age of Bombyx Batryticatus in Chinese Pharmacopoeia(2020). The results revealed that in the 102 batches of Bombyx Batryticatus, the qualification rate of silk gland was low; the content of total ash far exceeded the standard; the content of beauvericin varied greatly. The qualification rate of the silk gland of the 35 batches of Bombyx Batryticatus was only 47.49%, which could be increased to 73.00% if the number of silk gland was 2 to 4. The death rate of Bombyx Batryticatus at different infection ages was quite different, with uneven quality. Generally, the yield of Bombyx Batryticatus inoculated on the first day of the fifth instar was high with good quality. Therefore, in combination with the quality and actual production of Bombyx Batryticatus, the following suggestions were proposed for revision of Bombyx Batryticatus in Chinese Pharmacopoeia(2025): The number of silk gland should be revised as 2-4 bright brown or bright black silk glands, after which, the quality of Bombyx Batryticatus could be guaranteed, and the "quality identification based on character" could also be reflected scientifically; the content determination index that the content of beauvericin shall not be less than 0.017% should be added to better control the quality of Bombyx Batryticatus; the infection age should be revised as the first day of the fifth instar to narrow the age span, which could better fit the actual production and ensure the quality of Bombyx Batryticatus.
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Bombyx , Medicina Tradicional de Asia Oriental , Animales , Seda , LarvaRESUMEN
Employing the methyl ß-perfluoroalkylpropionate as the Michael acceptor, an efficient approach for the synthesis of perfluoroalkylated pyrrolidine-fused coumarins has been achieved. A tandem reaction involving [3 + 2] cycloaddition and intramolecular transesterification was proposed for the mechanism. The enhanced electrophilicity resulting from the strong electron-withdrawing ability of the perfluoroalkyl group was crucial for this tandem reaction.
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Cumarinas , Fluorocarburos , Ciclización , Estructura Molecular , PirrolidinasRESUMEN
An efficient silver-catalyzed method of decarboxylative radical allylation of α,α-difluoroarylacetic acids to build CF2-allyl bonds has been developed. Using allylsulfone as an allyl donor, α,α-difluorine substituted arylacetic acids bearing various functional groups are successfully allylated to access a series of 3-(α,α-difluorobenzyl)-1-propylene compounds in moderate to excellent yields in aqueous CH3CN solution under the mild conditions. Experimental studies disclosed that the α-fluorine substitution of arylacetic acid has a great influence on free radical activity and reactivity.
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A metal-free, oxidative decarboxylative reaction of aryldifluoroacetic acids with diaryl disulfides or thiols under mild reaction conditions has been developed. This is an efficient and straightforward radical cross-coupling method for the synthesis of diverse aryldifluoromethylthio ethers in moderate to excellent yields.
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A visible light mediated stereospecific C(sp2)-H difluoroalkylation of (Z)-aldoximes to (E)-difluoroalkylated ketoximes has been described. In this reaction, (hetero)-aromatic and aliphatic difluoroalkylated ketoximes could be obtained with the retention of the configuration of the starting aldoximes. A preliminary mechanism study showed that a difluoromethyl radical via an SET pathway was involved.
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Thallium (Tl) has been identified as a priority contaminant because of its severe toxic effects. Exact measurement of Tl is a challenge because it is difficult to avoid altering the element's chemical speciation during sampling, transport, and storage. In situ measurement may be a good choice. Based on the in situ technique of diffusive gradients in thin films (DGT), new DGT devices equipped with novel laboratory-synthesized manganese oxide (δ-MnO2) binding gels were developed and systematically validated for the measurement of Tl, including Tl(I) and Tl(III) species, in water. Comparison between Chelex binding gel and δ-MnO2 gel on the uptake kinetics of Tl demonstrated that δ-MnO2 binding gels could adsorb Tl rapidly and effectively. Removal of Tl from the δ-MnO2 gels was achieved by use of 1 mol·L-1 oxalic acid, yielding elution efficiencies of 1.0 for Tl(I) and 0.86 for TI(III). Theoretical responses from DGT devices loaded with δ-MnO2 gel (δ-MnO2-DGT) were obtained irrespective of pH (4-9) and ionic strength (0.1-200 mmol·L-1 NaNO3). δ-MnO2-DGT showed good potential for long-term monitoring of Tl due to its high adsorption capacity of 27.1 µg·cm-2 and the stable performance of δ-MnO2 binding gel kept in solution, containing only 10 mmol·L-1 NaNO3, for at least 117 days. Field deployment trials confirmed that δ-MnO2-DGT can accurately measure the time-averaged concentrations of Tl in fluvial watercourses. In summary, the newly developed δ-MnO2-DGT technique shows potential for environmental monitoring and biogeochemical investigation of Tl in waters.
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Geles/química , Compuestos de Manganeso/química , Óxidos/química , Ríos/química , Talio/análisis , Contaminantes Químicos del Agua/análisis , Adsorción , Difusión , Concentración de Iones de Hidrógeno , Cinética , Límite de Detección , Espectrometría de Masas/métodos , Concentración OsmolarRESUMEN
Fluoroalkylated quinoxlines with various groups were efficiently synthesized via a one-pot tandem Michael addition/azidation/cycloamination process. Under the mild and metal-free conditions, a bis-imine intermediate (4a) was detected and isolated for the first time. KI played a crucial role in this reaction. The mechanism was described.
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BACKGROUND: Urgent-start dialysis is a major problem for incident dialysis population. Urgent start on hemodialysis is associated with an increased risk of infectious or mechanical complications, and its mortality is equal to or higher than that of urgent start on peritoneal dialysis (PD). However, compared to patients starting PD in a planned setting, those on urgent-started PD have an increased risk of mechanical complications and lower technique survival. METHODS: In this study, 101 adult incident dialysis patients (≥18 years old) who underwent Tenckhoff catheter implantation were enrolled. All of the patients were grouped according to the urgent PD mode: the intermittent PD (IPD) or automatic PD (APD) group, and patients were followed for 1 year. The paired or independent t test was used to analyze the change of laboratory variables. Pearson chi-square test was applied to compare the short outcome between the 2 groups. RESULTS: When PD was treated for 7 days and 1 month, the APD group has the lower serum potassium and phosphorus levels than the IPD group. The incidence of catheter dysfunction was significantly lower in the APD group. The morbidity of infection associated with PD in the first year was lower in the APD group despite no significant difference existing. The technique survival and patient survival rate have no evident difference between the 2 groups. CONCLUSION: Compared to IPD, urgent start on APD could reduce the risk of mechanical complication, which could be considered a gentle, safe, and feasible alternative to urgent start on IPD.
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Atención Ambulatoria/métodos , Catéteres de Permanencia/efectos adversos , Fallo Renal Crónico/terapia , Diálisis Peritoneal/métodos , Complicaciones Posoperatorias/epidemiología , Estudios de Factibilidad , Femenino , Humanos , Fallo Renal Crónico/sangre , Fallo Renal Crónico/mortalidad , Masculino , Persona de Mediana Edad , Diálisis Peritoneal/instrumentación , Diálisis Peritoneal/mortalidad , Fosfatos/sangre , Complicaciones Posoperatorias/etiología , Periodo Posoperatorio , Potasio/sangre , Estudios Retrospectivos , Tasa de Supervivencia , Factores de Tiempo , Resultado del TratamientoRESUMEN
A silver-catalyzed oxidative decarboxylative gem-difluoromethylenation of difluoroacetates with activated alkenes under mild reaction conditions has been developed. This radical cascade reaction provides a new method for the construction of a variety of gem-difluoromethylenated oxindoles.
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A copper(0)-promoted direct reductive gem-difluoromethylenation of unactivated aryl or alkenyl halides with benzo-1,3-azolic (oxa-, thia- or aza-) difluoromethyl bromides or 2-bromodifluoromethyl-1,3-oxazoline has been developed for the construction of pharmaceutically important gem-difluoromethylene-linked twin molecules. The unique π-conjugated aryl-fused 1,3-azolic moiety in difluoromethyl bromide substrates could stabilise the reaction intermediates, which promotes the reactivities, providing facile access to the cross-coupling products in good to excellent yields, and allowing significant functional group tolerance. The reaction exhibits an enhanced neighbouring-group-participation effect. This method could provide a new strategy for the construction of gem-difluoromethylene-linked identical or nonidentical twin drugs through further functionalisation of 1,3-azolic skeletons.
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Alquenos/química , Derivados del Benceno/química , Bromuros/química , Cobre/química , Oxazoles/química , Catálisis , Halogenación , Metilación , Modelos Moleculares , Oxidación-ReducciónRESUMEN
Dissolved organic matter (DOM), a ubiquitous and active ingredient, is extensively involved in the transformation and migration of environmental pollutants in aquatic ecosystems. However, its chemical composition in acid mine drainage (AMD)-impacted rivers remains poorly characterized, hindering our understanding of its role in the biogeochemistry of key elements in contaminated fluvial environments. Here, we investigated the concentration of dissolved organic carbon (DOC) and spectroscopic and molecular characteristics of DOM in a headwater river contaminated with polymetallic mine-derived AMD in southern China. Terrestrial humic-like (C1) and typically groundwater-supplied aromatic protein/tyrosine-like (C2) substances which were partially from AMD, were identified as the predominant fluorescent components in the river water. Notably, tryptophan-like (C3) substances originating from tailings pond spills were only occasionally detected in the river. Although DOM biogeochemical transformations and degradation occurred in the lateral soil-water riparian interface and longitudinal in-stream transport processes, the molecular compositions identified by FT-ICR MS showed a core set of molecular formulae in the lignin/saturated compound/tannin region of the van Krevelen diagram of the water samples across the rivers. The complexation of DOM with typical metals in AMD was investigated using fluorescence quenching experiments. The results showed that the highest binding ability of Fe(III) to C2 followed by C1, with both detected in the experimental water samples. Mg(II) and Ca(II) strengthened the binding of DOM-Fe(III) when the ferric/DOM ratio was low, while Cu(II) weakened the binding of DOM-Fe(III) due to competition. Ca(II) inhibited the binding of Fe(III) to C1 but promoted the binding of the complex to C2 when both Cu(II) and Mg(II) were present. Since DOM-Fe(III) complexation was associated with the cotransport of AMD-derived metals/metalloids in diverse aqueous environments with multiple co-existing ions (typically Ca(II) input for remediation), our study on the composition of DOM and its complexation with metals can contribute to managing and remediating AMD-impacted rivers.
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Zinc Oxide nanoparticles (ZnO NPs) have dualistic properties due to their advantage and toxicity. However, the impact and mechanisms of ZnO NPs on the prefrontal lobe have limited research. This study investigates the behavioral changes following exposure to ZnO NPs (34â¯mg/kg, 30 days), integrating multiple behaviors and bioinformatics analysis to identify critical factors and regulatory mechanisms. The essential differentially expressed genes (DEGs) were identified, including ORC1, DSP, AADAT, SLITRK6, and STEAP1. Analysis of the DEGs based on fold change reveals that ZnO NPs primarily regulate cell survival, proliferation, and apoptosis in neural cells, damaging the prefrontal lobe. Moreover, disruption of cell communication, mineral absorption, and immune pathways occurs. Gene set enrichment analysis (GSEA) further shows enrichment of behavior, neuromuscular process, signal transduction in function, synapses-related, cAMP signaling, and immune pathways. Furthermore, alternative splicing (AS) genes highlight synaptic structure/function, synaptic signal transduction, immune responses, cell proliferation, and communication.
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Conducta Animal , Corteza Prefrontal , Óxido de Zinc , Animales , Óxido de Zinc/toxicidad , Corteza Prefrontal/efectos de los fármacos , Corteza Prefrontal/metabolismo , Ratones , Conducta Animal/efectos de los fármacos , Masculino , Nanopartículas del Metal/toxicidad , Regulación de la Expresión Génica/efectos de los fármacosRESUMEN
Photosynthetic bacteria (PSB) are suitable to live and remediate cadmium (Cd) in the slightly oxygenated or anaerobic flooding paddy field. However, there is currently limited study on the inhibition of Cd accumulation in rice by PSB, and the relevant mechanisms has yet to be elucidated. In the current study, we firstly used Rhodopseudomonas palustris SC06 (a typical PSB) as research target and combined physiology, biochemistry, microbiome and metabolome to evaluate the mechanisms of remeding Cd pollution in paddy field and inhibiting Cd accumulation in rice. Microbiome analysis results revealed that intensive inoculation with R. palustris SC06 successfully survived and multiplied in flooding paddy soil, and significantly increased the relatively abundance of anaerobic bacteria including Desulfobacterota, Anaerolineaceae, Geobacteraceae, and Gemmatimonadaceae by 46.40 %, 45.00 %, 50.12 %, and 21.30 %, respectively. Simultaneously, the structure of microbial community was regulated to maintain relative stability in the rhizosphere soil of rice under Cd stress. In turn, these bacteria communities reduced bioavailable Cd and enhanced residual Cd in soil, and induced the upregulation of sugar and organic acids in the rice roots, which further inhibited Cd uptake in rice seedlings, and dramatically improved the photosynthetic efficiency in the leaves and the activities of antioxidative enzymes in the roots. Finally, Cd content of the roots, stems, leaves, and grains significantly decreased by 38.14 %, 69.10 %, 83.40 %, and 37.24 % comparing with the control, respectively. This study provides a new strategy for the remediation of Cd-contaminated flooding paddy fields and the safe production of rice.
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Oryza , Rhodopseudomonas , Contaminantes del Suelo , Cadmio/análisis , Oryza/química , Disponibilidad Biológica , Suelo/química , Contaminantes del Suelo/análisisRESUMEN
A facile strategy for the preparation of two isomeric drospirenones 13 and 16 possessing a 14ß-hydrogen was developed, using 3ß-hydroxyandrost-5-en-17-one as the starting material. The total synthetic route involves eight steps, giving 2% overall yield. The structures of the main compounds 11, 13, 14 and 16 were determined by single crystal XRD analysis.
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Androstenos/síntesis química , Hidrógeno/química , Androstenos/química , Modelos Moleculares , Conformación Molecular , EstereoisomerismoRESUMEN
A heterotritopic copillar[5]arene monomer by introducing effective neutral guest moieties (methylene chains end-capped with cyano and triazole groups) to a pillar[5]arene macrocycle is prepared. This well-designed AB2 -type copillar[5]arene contains strong host-guest recognition motifs that are connected with relatively flexible and long linkers, thus efficiently assembles to form supramole-cular hyperbranched polymer (SHP) in chloroform solution, which is characterized by various techniques including (1) H NMR, DOSY, viscosity, DLS, and TEM. Particularly, this supramolecular polymer can be effectively depolymerized by adding a competitive butanedinitrile guest.
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Polímeros/química , Compuestos de Amonio Cuaternario/química , Calixarenos , Cloroformo/química , Química Clic , Luz , Microscopía Electrónica de Transmisión , Compuestos de Amonio Cuaternario/síntesis química , Dispersión de Radiación , ViscosidadRESUMEN
The purpose of this study was to ascertain the fresh processing technology of Cut Ophiopogonis Radix using a multi-index evaluation. This study comprehensively evaluated the fresh processing technology of sliced Cut Ophiopogonis Radix by investigating the cutting methods, cutting thickness, and drying conditions, and referring to The Chinese Pharmacopoeia 2020 edition. The appearance traits, internal quality (extract, total saponins, total flavonoids, total polysaccharides), and drying efficiency were used as evaluation indexes. The physical attributes of Cut Ophiopogonis Radix were found to vary based on the processing techniques employed. The shape, surface characteristics, texture, and color were observed to differ across the different methods. Notably, the apparent quality of Cut Ophiopogonis Radix was superior in samples processed using A1B1C1, A1B2C2, and A3B1C3 techniques. Drying time and energy consumption of Cut Ophiopogonis Radix produced by the A1B2C2 and A2B1C2 processes were less than those of other treatments, making them the optimal process for fresh processing Cut Ophiopogonis Radix. The impact of the cutting method and thickness on the extract was found to be statistically insignificant (P > 0.05). However, the drying method was observed to have a significant impact on the extract (P < 0.05). The cutting method, Cut thickness, and drying method did not affect the total saponin content (P > 0.05), but they had significant effects on the total polysaccharide and flavonoid contents (P < 0.01). Total polysaccharides were most affected by the cutting method, while total flavonoids were most affected by the drying condition. Based on the characteristics and internal quality, the fresh processing technology for Cut Ophiopogonis Radix was determined: fresh Ophiopogonis Radix was sliced to a thickness of 2-4 mm and dried at 55°C or a low temperature. The feasibility of Cut Ophiopogonis Radix is improved through its fresh processing. According to the evaluation indices, it is recommended to utilize the novel processing technique involving "fresh Ophiopogonis Radix" with fresh cuts, a cut thickness ranging from 2 to 4 mm, and drying at a temperature of 55â or through low-temperature drying. The Cut Ophiopogonis Radix exhibited favorable appearance and internal characteristics, thereby furnishing a scientific basis and innovative insights for the production of ophiopogon decoction slices.
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Cr(III) as one of the most concerned potentially toxic elements, is discharged from relevant industries and Cr(VI) reduction. Hydrogel-based adsorption could be one of the promising approaches for Cr(III) removal. Featured with environmental friendliness and low cost, carboxymethyl cellulose (CMC) was employed for the hydrogel synthesis, and attapulgite (APT) could be used to strengthen its stability. However, the adsorption performance and mechanisms need to be examined. In the present study, carboxymethyl cellulose-g-poly(acrylic acid-co-acrylamide)/ attapulgite (CMC-g-p(AA-co-AM)/APT) was synthesised via in situ copolymerisation. Its efficacy for removing Cr(III) from an aqueous solution was investigated using batch adsorption experiments. Results showed that the introduction of APT enhanced the thermal stability but decreased the swelling performance of the hydrogel. The prepared hydrogel could strongly adsorb Cr(III) at a wide pH range of 3.0-7.0. Cr(III) can be efficiently removed by the composite hydrogel within 1-2â h. At low concentration, CMC-g-p(AA-co-AM)/APT could slightly adsorbed more Cr(III) than CMC-g-p(AA-co-AM). The maximum absorption of CMC-g-p(AA-co-AM) and CMC-g-p(AA-co-AM)/APT were 74.8 and 47.7â mg/g at 298â K, respectively. The negative value of ΔHo and ΔGo indicated the adsorption of Cr(III) onto the two studied hydrogels is an exothermic and spontaneous process. Ion exchange and complexation, as implied by EDS, FT-IR and XPS, combining with electrostatic attraction are the possible adsorption mechanisms for Cr(III) onto the prepared hydrogels. All the results above suggests that the composite hydrogel CMC-g-p(AA-co-AM)/APT can be a promising candidate for the removal of Cr(III) from waste water.
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Hidrogeles , Contaminantes Químicos del Agua , Carboximetilcelulosa de Sodio , Adsorción , Acrilamida , Espectroscopía Infrarroja por Transformada de Fourier , Contaminantes Químicos del Agua/análisis , Concentración de Iones de Hidrógeno , Cinética , Cromo/análisisRESUMEN
Speciation of thallium (Tl) controls its fate and biogeochemical behaviors. Thus, a sensitive and accurately approach for Tl monitoring is of great demand due to its ultra-low concentration and sensitivity to redox change. In this study, diffusive gradients in thin-films technique (DGT) assembled with novel titanium peroxide (TP) binding gels (TP-DGT) was developed for in situ measurement of dissolved Tl(I) and Tl(III) in waters and sediments. Laboratory test showed a linear mass accumulation of Tl(I) and Tl(III) on the TP binding gels with the deployment time from 4 to 72 h. A fascinating performance of this novel DGT was achieved in a pH range of 4-9, ionic strength range of 0.1-200 mmol L-1, and humic acid concentration of 0-30 mg L-1 with a low detection limit of 0.3 ng L-1 for Tl(I) and 0.6 ng L-1 for Tl(III). The TP binding gels own excellent stability (1-365 d) and high capacity (73.5 µg Tl disc-1) which are suitable for long-term monitoring. Field application in a river indicated that TP-DGT could work effectively, comparable to the grab sampling in waters. For the first time, the TP-DGT coupled with oxygen optode was successfully applied to map 2D distribution patterns of Tl and oxygen simultaneously in the rhizosphere of M. verticillatum L. This study confirms TP-DGT is a promising tool for routine monitoring of Tl in waters and for investigating biogeochemical processes of Tl in sediments.