The thyroid is an essential endocrine organ in human body,and thyroid hormones(THs)are pivotal signaling molecules and mediators in various physiological processes.THs,particularly in their free form,play a critical r...The thyroid is an essential endocrine organ in human body,and thyroid hormones(THs)are pivotal signaling molecules and mediators in various physiological processes.THs,particularly in their free form,play a critical role in regulating body temperature and in the metabolism of lipid and glucose,making the maintenance of TH levels crucial for human health.THs undergo a series of metabolic processes,producing TH metabolites(THMs).THMs are significant in endocrine regulation,such as 3,5-diiothyronine(3,5-T2)and 3-iodothyronamine(3-T1AM),which exhibit activities akin to THs.The production and distribution of THMs are intricately linked to the function of specific organs and tissues,highlighting the need for advanced research into the determination and mechanisms of THMs in body.Exposure to endocrine disrupting chemicals(EDCs)can significantly affect the levels of thyroid stimulating hormone(TSH)and THs.This review utilizes machine learning to analyze epidemiological data,identifying potential EDCs that pose risks of hyperthyroidism and hypothyroidism.Additionally,it delves into the toxicological mechanisms of these EDCs,examining their effects on TH production,binding processes,related proteins,and metabolic enzymes.This approach effectively bridges the gap between epidemiological studies and toxicological researches,laying the groundwork for future research trends.By integrating epidemiological studies with machine learning,this review offers insightful perspectives on the potential risks associated with chemical exposure and underscores the necessity for further research in understanding the impact of EDCs on TH metabolism and TH-related health effects.展开更多
Chronic obstructive pulmonary disease(COPD), lung cancer(LC) and tuberculosis(TB) are common chronic lung diseases that generate a large disease burden and significant health care resource use in China. The aim of thi...Chronic obstructive pulmonary disease(COPD), lung cancer(LC) and tuberculosis(TB) are common chronic lung diseases that generate a large disease burden and significant health care resource use in China. The aim of this study was to quantify spatial patterns and effects of air pollution and meteorological factors on hospitalization of COPD, LC and TB in Beijing. Daily counts of hospitalization for 2010 were obtained from the Beijing Urban Employees Basic Medical Insurance(UEBMI) system.Bayesian hierarchical Poisson regression models were applied to identify spatial patterns of hospitalization for COPD, LC and TB at the district level and explore associations with inhalable particulate matter(aerodynamic diameter <10 μm, PM10), sulfur dioxide(SO2), nitrogen dioxide(NO2), mean temperature and relative humidity. There were 18,882, 14,295 and 2,940 counts of hospitalizations for COPD, LC and TB respectively, in Beijing in 2010. Clusters of high relative risk were in different locations for the three diseases. The effect of relative humidity on COPD hospitalization was most significant with a relative risk(RR) of 1.070(95%CI: 1.054, 1.086) per one percent increase. For lung cancer hospitalization, exposure to ambient SO2 was associated with a RR of 1.034(95%CI: 1.011, 1.058) per μg m–3 increase. For tuberculosis, the effect of mean temperature was significant with a RR of 1.107(95%CI: 1.038, 1.180) per °C increase. Risk factors and spatial patterns were different for hospitalization of non-infectious and infectious chronic lung disease in Beijing. Even over a short time period(one year), associations were apparent with air pollution and meteorological factors.展开更多
Salinization in estuarine wetlands significantly alters the balance between their nitrogen(N)removal and retention abilities but these processes have not yet been characterized effectively.In the present study,the pot...Salinization in estuarine wetlands significantly alters the balance between their nitrogen(N)removal and retention abilities but these processes have not yet been characterized effectively.In the present study,the potential rates of sediment denitrification,anaerobic ammonium oxidation(anammox),and dissimilatory nitrate reduction to ammonium(DNRA)were mapped using N isotope tracing methods along salinity gradients across the Yellow River Delta wetland(YRDW)in China.The contribution of anammox to total dissimilatory N transformations in YRDW was merely 6.8%,whereas denitrification and DNRA contributed 52.3%and 40.9%,respectively.The potential rate of denitrification(5.82μmol/kg/h)decreased significantly along salinity gradients and markedly exceeded DNRA potential rate(2.7μmol/kg/h)in fresh wetlands,but was lower than that of DNRA in oligohaline wetlands(3.06 and 3.18μmol/kg/h,respectively).Moreover,a significantly positive relationship between salinity and DNRA/denitrification was obeserved,indicating that increased salinity may favor DNRA over denitrification.Furthermore,total sulfur(TS)content and ratio of total organic carbon to total nitrogen(C/N)increased with the salinity gradient and showed evident positive relationships with the DNRA/denitrification ratio.In this study,we proved that increased salinization resulted in the dominance of DNRA over denitrification,possible through the addition of S and alteration of the C/N in estuarine wetlands,leading to increased N retention in estuarine wetlands during salinization,which would enhance the eutrophication potential within wetlands and in downstream ecosystems.展开更多
Racemicα-chloro imidazol-2-yl-ketones undergo an enantioconvergent photoactivated C–C bond formation with N-aryl glycines catalyzed by a single bis-cyclometalated chiral-at-rhodium catalyst in yields of up to 80%and...Racemicα-chloro imidazol-2-yl-ketones undergo an enantioconvergent photoactivated C–C bond formation with N-aryl glycines catalyzed by a single bis-cyclometalated chiral-at-rhodium catalyst in yields of up to 80%and up to 98%enantiomeric excess(ee).Control experiments support a mechanism which is initiated by a single electron transfer from N-aryl glycinate to the photochemically excited rhodium-boundα-chloro imidazol-2-yl-ketone,followed by chloride fragmentation of theα-chloroketone,decarboxylation of the glycinate,and a subsequent highly stereocontrolled radical-radical coupling.This work showcases the ability of the chiral rhodium catalyst to serve a dual function as chiral Lewis acid and at the same time as the photoredox active species upon substrate binding.展开更多
Chiral β-amino alcohols are important building blocks for the synthesis of drugs, natural products, chiral auxiliaries, chiral ligands and chiral organocatalysts. The catalytic asymmetric β-amination of alcohols off...Chiral β-amino alcohols are important building blocks for the synthesis of drugs, natural products, chiral auxiliaries, chiral ligands and chiral organocatalysts. The catalytic asymmetric β-amination of alcohols offers a direct strategy to access this class of molecules. Herein, we report a general intramolecular C(sp^(3))–H nitrene insertion method for the synthesis of chiral oxazolidin-2-ones as precursors of chiral β-amino alcohols. Specifically, the ring-closing C(sp^(3))–H amination of N-benzoyloxycarbamates with 2 mol% of a chiral ruthenium catalyst provides cyclic carbamates in up to 99% yield and with up to 99% ee.The method is applicable to benzylic, allylic, and propargylic C–H bonds and can even be applied to completely non-activated C(sp^(3))–H bonds, although with somewhat reduced yields and stereoselectivities. The obtained cyclic carbamates can subsequently be hydrolyzed to obtain chiral β-amino alcohols. The method is very practical as the catalyst can be easily synthesized on a gram scale and can be recycled after the reaction for further use. The synthetic value of the new method is demonstrated with the asymmetric synthesis of a chiral oxazolidin-2-one as intermediate for the synthesis of the natural product aurantioclavine and chiral β-amino alcohols that are intermediates for the synthesis of chiral amino acids, indane-derived chiral Box-ligands, and the natural products dihydrohamacanthin A and dragmacidin A.展开更多
基金funded by the National Natural Science Foundation of China(42277425,42161134001,U22A20614)“the Fundamental Research Funds for the Central Universities”,Nankai University(63171109)+4 种基金sponsored by Tianjin Health Research Project(TJWJ2023MS028)Tianjin Science and Technology planning project(21JCZDJC00330)National Clinical Key Discipline Cohort Study Project(GJZDZKZBDL 2022-)Tianjin Key Medical Discipline(Specialty)Construction Project(TJYXZDXK-043A)Ministry of Education,China(T2017002).
文摘The thyroid is an essential endocrine organ in human body,and thyroid hormones(THs)are pivotal signaling molecules and mediators in various physiological processes.THs,particularly in their free form,play a critical role in regulating body temperature and in the metabolism of lipid and glucose,making the maintenance of TH levels crucial for human health.THs undergo a series of metabolic processes,producing TH metabolites(THMs).THMs are significant in endocrine regulation,such as 3,5-diiothyronine(3,5-T2)and 3-iodothyronamine(3-T1AM),which exhibit activities akin to THs.The production and distribution of THMs are intricately linked to the function of specific organs and tissues,highlighting the need for advanced research into the determination and mechanisms of THMs in body.Exposure to endocrine disrupting chemicals(EDCs)can significantly affect the levels of thyroid stimulating hormone(TSH)and THs.This review utilizes machine learning to analyze epidemiological data,identifying potential EDCs that pose risks of hyperthyroidism and hypothyroidism.Additionally,it delves into the toxicological mechanisms of these EDCs,examining their effects on TH production,binding processes,related proteins,and metabolic enzymes.This approach effectively bridges the gap between epidemiological studies and toxicological researches,laying the groundwork for future research trends.By integrating epidemiological studies with machine learning,this review offers insightful perspectives on the potential risks associated with chemical exposure and underscores the necessity for further research in understanding the impact of EDCs on TH metabolism and TH-related health effects.
文摘Chronic obstructive pulmonary disease(COPD), lung cancer(LC) and tuberculosis(TB) are common chronic lung diseases that generate a large disease burden and significant health care resource use in China. The aim of this study was to quantify spatial patterns and effects of air pollution and meteorological factors on hospitalization of COPD, LC and TB in Beijing. Daily counts of hospitalization for 2010 were obtained from the Beijing Urban Employees Basic Medical Insurance(UEBMI) system.Bayesian hierarchical Poisson regression models were applied to identify spatial patterns of hospitalization for COPD, LC and TB at the district level and explore associations with inhalable particulate matter(aerodynamic diameter <10 μm, PM10), sulfur dioxide(SO2), nitrogen dioxide(NO2), mean temperature and relative humidity. There were 18,882, 14,295 and 2,940 counts of hospitalizations for COPD, LC and TB respectively, in Beijing in 2010. Clusters of high relative risk were in different locations for the three diseases. The effect of relative humidity on COPD hospitalization was most significant with a relative risk(RR) of 1.070(95%CI: 1.054, 1.086) per one percent increase. For lung cancer hospitalization, exposure to ambient SO2 was associated with a RR of 1.034(95%CI: 1.011, 1.058) per μg m–3 increase. For tuberculosis, the effect of mean temperature was significant with a RR of 1.107(95%CI: 1.038, 1.180) per °C increase. Risk factors and spatial patterns were different for hospitalization of non-infectious and infectious chronic lung disease in Beijing. Even over a short time period(one year), associations were apparent with air pollution and meteorological factors.
基金supported by the National Key Research and Development Program of China(No.2017YFC0404401)the Central Public-interest Scientific Institution Basal Research Fund(No.HKY-JBYW-2018-07)。
文摘Salinization in estuarine wetlands significantly alters the balance between their nitrogen(N)removal and retention abilities but these processes have not yet been characterized effectively.In the present study,the potential rates of sediment denitrification,anaerobic ammonium oxidation(anammox),and dissimilatory nitrate reduction to ammonium(DNRA)were mapped using N isotope tracing methods along salinity gradients across the Yellow River Delta wetland(YRDW)in China.The contribution of anammox to total dissimilatory N transformations in YRDW was merely 6.8%,whereas denitrification and DNRA contributed 52.3%and 40.9%,respectively.The potential rate of denitrification(5.82μmol/kg/h)decreased significantly along salinity gradients and markedly exceeded DNRA potential rate(2.7μmol/kg/h)in fresh wetlands,but was lower than that of DNRA in oligohaline wetlands(3.06 and 3.18μmol/kg/h,respectively).Moreover,a significantly positive relationship between salinity and DNRA/denitrification was obeserved,indicating that increased salinity may favor DNRA over denitrification.Furthermore,total sulfur(TS)content and ratio of total organic carbon to total nitrogen(C/N)increased with the salinity gradient and showed evident positive relationships with the DNRA/denitrification ratio.In this study,we proved that increased salinization resulted in the dominance of DNRA over denitrification,possible through the addition of S and alteration of the C/N in estuarine wetlands,leading to increased N retention in estuarine wetlands during salinization,which would enhance the eutrophication potential within wetlands and in downstream ecosystems.
基金supported by the Deutsche Forschungsgemeinschaft(ME 1805/17-1)
文摘Racemicα-chloro imidazol-2-yl-ketones undergo an enantioconvergent photoactivated C–C bond formation with N-aryl glycines catalyzed by a single bis-cyclometalated chiral-at-rhodium catalyst in yields of up to 80%and up to 98%enantiomeric excess(ee).Control experiments support a mechanism which is initiated by a single electron transfer from N-aryl glycinate to the photochemically excited rhodium-boundα-chloro imidazol-2-yl-ketone,followed by chloride fragmentation of theα-chloroketone,decarboxylation of the glycinate,and a subsequent highly stereocontrolled radical-radical coupling.This work showcases the ability of the chiral rhodium catalyst to serve a dual function as chiral Lewis acid and at the same time as the photoredox active species upon substrate binding.
基金supported by the Deutsche Forschungsgemeinschaft(ME 1805/15-1)。
文摘Chiral β-amino alcohols are important building blocks for the synthesis of drugs, natural products, chiral auxiliaries, chiral ligands and chiral organocatalysts. The catalytic asymmetric β-amination of alcohols offers a direct strategy to access this class of molecules. Herein, we report a general intramolecular C(sp^(3))–H nitrene insertion method for the synthesis of chiral oxazolidin-2-ones as precursors of chiral β-amino alcohols. Specifically, the ring-closing C(sp^(3))–H amination of N-benzoyloxycarbamates with 2 mol% of a chiral ruthenium catalyst provides cyclic carbamates in up to 99% yield and with up to 99% ee.The method is applicable to benzylic, allylic, and propargylic C–H bonds and can even be applied to completely non-activated C(sp^(3))–H bonds, although with somewhat reduced yields and stereoselectivities. The obtained cyclic carbamates can subsequently be hydrolyzed to obtain chiral β-amino alcohols. The method is very practical as the catalyst can be easily synthesized on a gram scale and can be recycled after the reaction for further use. The synthetic value of the new method is demonstrated with the asymmetric synthesis of a chiral oxazolidin-2-one as intermediate for the synthesis of the natural product aurantioclavine and chiral β-amino alcohols that are intermediates for the synthesis of chiral amino acids, indane-derived chiral Box-ligands, and the natural products dihydrohamacanthin A and dragmacidin A.
