Water residence time controls seasonal nitrous oxide budget in a semi-enclosed bay: Insights from an improvement estimation method.

This study developed an estimation method for the N2O budget using 15N stable isotope labeling techniques, a dual-layer model and a box model, which was used to elucidate the underlying dynamics of N2O accumulation in Zhanjiang Bay. The results showed that although the net input of N2O during the rainy season was 2.36 times higher than that during the dry season, the overall N2O concentration was only 66.6 % of that during the dry season due to the extended water residence time in the dry season. Our findings highlighted that water residence time was the key factor for the N2O emission, and a longer water residence time was unfavorable for the efflux of N2O through hydrodynamic processes and was more conducive to the production and accumulation of N2O within the bay. This research enhanced our comprehension of N2O dynamics and provided crucial insights for refining nitrogen management strategies and mitigation efforts.

The impact of algal blooms on promoting in-situ N2O emissions: A case in Zhanjiang bay, China.

Under the influence of many factors, such as climate change, anthropogenic eutrophication, and the development of aquaculture, the area and frequency of algal blooms have showed an increasing trend worldwide, which has become a challenging issue at present. However, the coupled relationship between nitrous oxide (N2O) and algal blooms and the underlying mechanisms remain unclear. To address this issue, 15N isotope cultures and quantitative polymerase chain reaction (qPCR) experiments were conducted in Zhanjiang Bay during algal and non-algal bloom periods. The results showed that denitrification and nitrification-denitrification were the two processes responsible for the in-situ production of N2O during algal and non-algal bloom periods. Stable isotope rate cultivation experiments indicated that denitrification and nitrification-denitrification were promoted in the water during the algal bloom period. The in-situ production of N2O during the algal bloom period was three-fold that during the non-algal bloom period. This may be because fresh particulate organic matter (POM) from the organisms responsible for the algal bloom provides the necessary anaerobic and hypoxic environment for denitrification and nitrification-denitrification in the degradation environment. Additionally, a positive linear correlation between N2O concentrations and ammonia-oxidizing bacteria (AOB) and denitrifying bacteria (nirK and nirS) also supported the significant denitrification and nitrification-denitrification occurring in the water during the algal bloom period. However, the algal bloom changed the main process for the in-situ production of N2O, wherein it shifted from denitrification during the non-algal bloom period to nitrification-denitrification during the algal bloom period. The results of our study will improve our understanding of the processes responsible for the in-situ production of N2O during the algal bloom period, and can help formulate effective policies to mitigate N2O emissions in the bay.

Case report: A novel biallelic FTO variant causing multisystem anomalies with severe epilepsy, widening the spectrum of FTO syndrome.

The fat mass and obesity-associated gene (FTO) codes for a DNA/RNA demethylase. Pathological variants in this gene are rare, with only three reports in the literature, all with mutations in the catalytic domain. We report the first biallelic human variant in fat mass and obesity-associated gene (c.287G>C, p.Arg96Pro/R96P) outside the catalytic site, causing numerous abnormalities across multiple organ systems, affecting respiratory, cardiovascular, and neurological function. Biochemical assays of cells with the patient's variant were performed to further quantify the effect of the variant on function. Loss-of-function resulting from the patient's R96P missense variant was demonstrated with in vitro biochemical characterization of demethylase activity, resulting in a 90% reduction in function of the fat mass and obesity-associated protein compared to wild-type. Our findings demonstrate a novel fat mass and obesity-associated gene non-catalytic site variant with a unique patient phenotype of bilateral multifocal epilepsy and multisystem congenital anomalies.

Recent advances of electrochemical sensors for detecting and monitoring ROS/RNS.

Reactive oxygen species (ROS) and reactive nitrogen species (RNS) are prominent metabolic products which show well-established significance. At relatively low concentrations, they play multifaceted roles in regulating a number of physiological processes. Overproduction of ROS/RNS contributes to the pathogenesis of a plethora of physiological disorders, including but not limited to cardiovascular diseases, neurodegenerative diseases, cancer. Electrochemistry have been extensively used for detecting and monitoring ROS/RNS, benefiting from their inherent advantages including fast response, low costs, real-time detection, high sensitivity and selectivity. This review focuses on three types of ROS/RNS (H2O2, O2-, NO) with emphasis on their electrochemical detection/monitoring respectively. We demonstrate the application of electrochemical strategies for ROS/RNS detection in body fluids, in vitro, and in vivo, outlining the hardware architecture and comparing analytical performance of these sensors. This review aims for a holistic view of limitations in existing ROS/RNS detection by comprehensively explaining the shortcomings of the current works in the hope of drawing attentions to the challenges of ROS/RNS electrochemical technologies. We pay particular attention to in vitro and in vivo sensors and extend our evaluation to suggest possible solutions. Specifically, this review focuses on the development of currently nanotechnologies, biomimetic engineering, 3D-culture methods and implanted sensors to provide a guideline for future works.

Substrate-Controlled Transformation of Azobenzenes to Indazoles and Indoles via Rh(III)-Catalysis.

Rh(III)-catalyzed substrate-controlled transformation of azobenzenes to indazoles and 2-acyl (NH) indoles is achieved via C-H functionalization. Generally, good functional groups tolerance, satisfying yields, and excellent regio-selectivity are achieved in this reaction. Mechanistically, the reaction with acrylates undergoes ß-hydride elimination, while the reaction with vinyl ketones or acrylamides undergoes nucleophilic addition. Copper acetate was supposed to play different roles in the ß-hydride elimination to furnish indazoles and nucleophilic addition of C-Rh bond to deliver 2-acyl (NH) indoles.

Rh(III)-catalyzed cascade oxidative olefination/cyclization of picolinamides and alkenes via C-H activation.

Rh(III)-catalyzed cascade oxidative alkenylation/cyclization of picolinamides and alkenes to furnish pyrido pyrrolone derivatives is described, in which three C-H bonds and one N-H bond broke, while one C-C bond and one C-N bond formed. The reaction proceeded with high yield and high regioselectivity and stereoselectivity. Moreover, copper acetate can also be used in catalytic amounts with O2 serving as the terminal oxidant.

CuCl-catalyzed ortho trifluoromethylation of arenes and heteroarenes with a pivalamido directing group.

The CuCl catalyzed direct trifluoromethylation of sp(2) C-H bonds has been realized, using the Togni reagent as the CF3 source. This reaction achieves the goal of regio-selectively converting C-H into C-CF3 with ecological and readily available starting materials.

Assembly of 3-substituted isocoumarins via a CuI-catalyzed domino coupling/addition/deacylation process.

An efficient strategy for the synthesis of a variety of 3-substituted isocoumarins has been developed. The reaction proceeded from o-halobenzoic acids and 1,3-diketones via a copper(I)-catalyzed domino reaction in DMF under the action of K(3)PO(4) at 90-120 °C without a ligand to afford the corresponding 3-substituted isocoumarin derivatives in good to excellent yields. o-Halobenzoic acids could be o-iodobenzoic acid, o-bromobenzoic acid, and o-chlorobenzoic acid derivatives. 1,3-Diketones could be alkyl- and aryl-substituted 1,3-diketones.

Synthesis of 2-mercaptobenzothiazoles via DBU-promoted tandem reaction of o-haloanilines and carbon disulfide.

An efficient strategy for the synthesis of a variety of 2-mercaptobenzothiazole derivatives has been developed. The reaction proceeded from o-haloaniline derivatives and carbon disulfide via a tandem reaction in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) to afford the corresponding 2-mercaptobenzothiazole derivatives in good to excellent yields.

A protocol to 2-aminobenzimidazoles via copper-catalyzed cascade addition and cyclization of o-haloanilines and carbodiimides.

An efficient strategy for the synthesis of a variety of 2-animobenzimidazole derivatives has been developed. The reaction proceeded from o-haloanilines and carbodiimides via copper(I)-catalyzed domino reaction in the presence of tert-butoxide to afford the corresponding 2-animobenzimidazole derivatives in good to excellent yields. o-Haloanilines could be o-iodoaniline, o-bromoaniline, and o-chloroaniline derivatives. Carbodiimides could be symmetrical and unsymmetrical substrates with aryl or alkyl substituents. The reaction exhibited a good regioselectivity when unsymmetrical carbodiimides were employed.