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1.
Cell Mol Life Sci ; 81(1): 122, 2024 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-38456997

RESUMO

Doxorubicin-induced cardiotoxicity (DIC), which is a cardiovascular complication, has become the foremost determinant of decreased quality of life and mortality among survivors of malignant tumors, in addition to recurrence and metastasis. The limited ability to accurately predict the occurrence and severity of doxorubicin-induced injury has greatly hindered the prevention of DIC, but reducing the dose to mitigate side effects may compromise the effective treatment of primary malignancies. This has posed a longstanding clinical challenge for oncologists and cardiologists. Ferroptosis in cardiomyocytes has been shown to be a pivotal mechanism underlying cardiac dysfunction in DIC. Ferroptosis is influenced by multiple factors. The innate immune response, as exemplified by neutrophil extracellular traps (NETs), may play a significant role in the regulation of ferroptosis. Therefore, the objective of this study was to investigate the involvement of NETs in doxorubicin-induced cardiomyocyte ferroptosis and elucidate their regulatory role. This study confirmed the presence of NETs in DIC in vivo. Furthermore, we demonstrated that depleting neutrophils effectively reduced the occurrence of doxorubicin-induced ferroptosis and myocardial injury in DIC. Additionally, our findings showed the pivotal role of high mobility group box 1 (HMGB1) as a critical molecule implicated in DIC and emphasized its involvement in the modulation of ferroptosis subsequent to NETs inhibition. Mechanistically, we obtained preliminary evidence suggesting that doxorubicin-induced NETs could modulate yes-associated protein (YAP) activity by releasing HMGB1, which subsequently bound to toll like receptor 4 (TLR4) on the cardiomyocyte membrane, thereby influencing cardiomyocyte ferroptosis in vitro. Our findings suggest that doxorubicin-induced NETs modulate cardiomyocyte ferroptosis via the HMGB1/TLR4/YAP axis, thereby contributing to myocardial injury. This study offers a novel approach for preventing and alleviating DIC by targeting alterations in the immune microenvironment.


Assuntos
Armadilhas Extracelulares , Ferroptose , Proteína HMGB1 , Cardiopatias , Humanos , Miócitos Cardíacos/metabolismo , Armadilhas Extracelulares/metabolismo , Proteína HMGB1/metabolismo , Receptor 4 Toll-Like/metabolismo , Cardiotoxicidade/metabolismo , Qualidade de Vida , Cardiopatias/metabolismo , Doxorrubicina/efeitos adversos
2.
J Am Chem Soc ; 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38717282

RESUMO

In this study, we investigated the role of aluminum cations in facilitating hydride transfer during the hydrogenation of imines within the context of Noyori-type metal-ligand cooperative catalysis. We propose a novel model involving aluminum cations directly coordinated with imines to induce activation from the lone pair electron site, a phenomenon termed σ-induced activation. The aluminum metal-hydride amidate complex ("HMn-NAl") exhibits a higher ability of hydride transfer in the hydrogenation of imines compared to its lithium counterpart ("HMn-NLi"). Density functional theory (DFT) calculations uncover that the aluminum cation efficiently polarizes unsaturated bonds through σ-electron-induced activation in the transition state of hydride transfer, thereby enhancing substrate electrophilicity more efficiently. Additionally, upon substrate coordination, aluminum's coordination saturation improves the hydride nucleophilicity of the HMn-NAl complex via the breakage of the Al-H coordination bond.

3.
Ecotoxicol Environ Saf ; 261: 115110, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37300917

RESUMO

The natural resistance-associated macrophage protein (NRAMP) gene family plays a key role in essential mineral nutrient homeostasis, as well as toxic metal accumulation, translocation, and detoxification. Although the NRAMP family genes have been widely identified in various species, they still require to be analyzed comprehensively in tree species. In this study, a total of 11 NRAMP members (PtNRAMP1-11) were identified in Populus trichocarpa, a woody model plant, and further subdivided into three groups based on phylogenetic analysis. Chromosomal location analysis indicated that the PtNRAMP genes were unevenly distributed on six of the 19 Populus chromosomes. Gene expression analysis indicated that the PtNRAMP genes were differentially responsive to metal stress, including iron (Fe) and manganese (Mn) deficiency, as well as Fe, Mn, zinc (Zn), and cadmium (Cd) toxicity. Furthermore, the PtNRAMP gene functions were characterized using a heterologous yeast expression system. The results showed that PtNRAMP1, PtNRAMP2, PtNRAMP4, PtNRAMP9, PtNRAMP10, and PtNRAMP11 displayed the ability to transport Cd into yeast cells. In addition, PtNRAMP1, PtNRAMP6, and PtNRAMP7 complemented the Mn uptake mutant, while PtNRAMP1, PtNRAMP6, PtNRAMP7, and PtNRAMP9 complemented the Fe uptake mutant. In conclusion, our findings revealed the respective functions of PtNRAMPs during metal transport as well as their potential role in micronutrient biofortification and phytoremediation.


Assuntos
Proteínas de Transporte de Cátions , Metais Pesados , Populus , Populus/genética , Populus/metabolismo , Cádmio/metabolismo , Saccharomyces cerevisiae/metabolismo , Filogenia , Metais Pesados/toxicidade , Metais Pesados/metabolismo , Proteínas de Transporte de Cátions/genética , Proteínas de Transporte de Cátions/metabolismo
4.
Int J Mol Sci ; 23(24)2022 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-36555194

RESUMO

The plant cytoskeleton, consisting of actin filaments and microtubules, is a highly dynamic filamentous framework involved in plant growth, development, and stress responses. Recently, research has demonstrated that the plant cytoskeleton undergoes rapid remodeling upon sensing pathogen attacks, coordinating the formation of microdomain immune complexes, the dynamic and turnover of pattern-recognizing receptors (PRRs), the movement and aggregation of organelles, and the transportation of defense compounds, thus serving as an important platform for responding to pathogen infections. Meanwhile, pathogens produce effectors targeting the cytoskeleton to achieve pathogenicity. Recent findings have uncovered several cytoskeleton-associated proteins mediating cytoskeletal remodeling and defense signaling. Furthermore, the reorganization of the actin cytoskeleton is revealed to further feedback-regulate reactive oxygen species (ROS) production and trigger salicylic acid (SA) signaling, suggesting an extremely complex role of the cytoskeleton in plant immunity. Here, we describe recent advances in understanding the host cytoskeleton dynamics upon sensing pathogens and summarize the effectors that target the cytoskeleton. We highlight advances in the regulation of cytoskeletal remodeling associated with the defense response and assess the important function of the rearrangement of the cytoskeleton in the immune response. Finally, we propose suggestions for future research in this area.


Assuntos
Citoesqueleto de Actina , Citoesqueleto , Citoesqueleto/metabolismo , Citoesqueleto de Actina/metabolismo , Microtúbulos/metabolismo , Actinas/metabolismo , Plantas/metabolismo , Imunidade Vegetal/fisiologia , Proteínas do Citoesqueleto/metabolismo
5.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 41(2): 143-50, 2016 Feb.
Artigo em Zh | MEDLINE | ID: mdl-26932211

RESUMO

OBJECTIVE: To explore the correlation between diabetic nephropathy (DN) and cognitive impairment through examining the cognitive function and the metabolism of the cerebrum in Type 2 diabetes mellitus patients at different stages of renal function.
 METHODS: Eighty six patients with Type 2 diabetes mellitus (T2DM) were enrolled for this study. According to the urinary albumin excretion rate (UAER), the patients were divided into a T2DM without DN group (DM group, n=33), an early DN group (DN-III group, n=26) and a clinical stage group (DN-IV group, n=27). Thirty healthy adults were selected as a control group (NC group). Biochemical indexes and UAER were measured, and glomerular filtration rate (GFR) was detected by single-photon emission computed tomography (SPECT). The cognitive function was measured by Montreal Cognitive Assessment (MoCA, Beijing version) and mini-mental state examination (MMSE). The peak areas of N-acetylasparte (NAA), creatine (Cr), choline-containing compounds (Cho) were detected by proton magnetic resonance spectroscopy (1H-MRS).
 RESULTS: 1) There was no statistical difference in MMSE scores between the DM group and the control group. The scores of MoCA in the DN-III group or in the DN-IV group were significant less than that in the NC group (F=3.66, P<0.05); 2) There was significant difference in left N-acetylaspartate (LNAA), left choline (LCho) among the diabetes groups. Compared with the DM group, the level of LNAA was decreased significantly (t=3.826, P<0.05) while the LCho was increased significantly (t=4.373, P<0.05) in the DN groups, with statistic difference between the 2 groups (t=3.693, P<0.05); 3) The MoCA scores of T2DM patients were negatively correlated with UAER (r=-0.285, P<0.05), while positively correlated with GFR (r=0.379, P<0.05); 4) Logistic regression analysis indicated that UAER and GFR were the major risky factors for diabetic cognitive impairment.
 CONCLUSION: Diabetic cognitive impairment is closely correlated with the nephropathy in patients with Type 2 diabetes. With the decline in glomerular filtration function, the cognitive disorder tends to be aggravated. The hippocampal brain metabolism may have some changes in left side of Cho/Cr in patients with diabetic nephropathy.


Assuntos
Transtornos Cognitivos/epidemiologia , Diabetes Mellitus Tipo 2/fisiopatologia , Nefropatias Diabéticas/epidemiologia , Adulto , Ácido Aspártico/análogos & derivados , Ácido Aspártico/metabolismo , Estudos de Casos e Controles , Cérebro/metabolismo , Colina/metabolismo , Cognição , Creatina/metabolismo , Taxa de Filtração Glomerular , Humanos , Testes Neuropsicológicos
6.
Polymers (Basel) ; 16(4)2024 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-38399879

RESUMO

Superabsorbent polymers are new functional polymeric materials that can absorb and retain liquids thousands of times their masses. This paper reviews the synthesis and modification methods of different superabsorbent polymers, summarizes the processing methods for different forms of superabsorbent polymers, and organizes the applications and research progress of superabsorbent polymers in industrial, agricultural, and biomedical industries. Synthetic polymers like polyacrylic acid, polyacrylamide, polyacrylonitrile, and polyvinyl alcohol exhibit superior water absorption properties compared to natural polymers such as cellulose, chitosan, and starch, but they also do not degrade easily. Consequently, it is often necessary to modify synthetic polymers or graft superabsorbent functional groups onto natural polymers, and then crosslink them to balance the properties of material. Compared to the widely used superabsorbent nanoparticles, research on superabsorbent fibers and gels is on the rise, and they are particularly notable in biomedical fields like drug delivery, wound dressing, and tissue engineering.

7.
Int J Biol Macromol ; 228: 732-743, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36563811

RESUMO

Plant AT-rich sequence and zinc-binding (PLATZ) proteins are a class of plant-specific zinc finger transcription factors that perform critical functions in plant development and resistance. However, the function of PLATZs in heavy metal tolerance has not yet been investigated. Moreover, only a few PLATZ proteins have been functionally characterized in tree species. In this study, we identified 18 PtPLATZ genes in Populus trichocarpa, an important woody model plant, and classified them into five groups. PtPLATZ genes attributed to the same clade usually possess similar exon-intron structures containing two or three introns, as well as a similar motif composition. Furthermore, chromosomal location analysis indicated an uneven distribution of PtPLATZ genes on 13 of the 19 Populus chromosomes. Promoter cis-acting element prediction and gene expression analysis showed that PtPLATZ genes were highly responsive to heavy metal stress. Heterologous yeast expression revealed that PtPLATZ1, PtPLATZ2, PtPLATZ3, PtPLATZ4, PtPLATZ8 and PtPLATZ9 are significantly involved in Cd tolerance. In addition, transgenic expression of PtPLATZ3 significantly enhanced Cd tolerance and accumulation, slowed the decline in chlorophyll content, maintained membrane integrity in Populus, and increased the expression of genes related to Cd tolerance and accumulation. In conclusion, our results suggest the potential of PtPLATZ3 to improve Cd tolerance and accumulation in Populus, which is of great significance for phytoremediation.


Assuntos
Metais Pesados , Populus , Cádmio/toxicidade , Cádmio/metabolismo , Populus/genética , Populus/metabolismo , Biodegradação Ambiental , Metais Pesados/toxicidade , Metais Pesados/metabolismo , Íntrons , Proteínas de Plantas/química , Regulação da Expressão Gênica de Plantas
8.
J Plant Physiol ; 288: 154076, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37657305

RESUMO

EIN3-binding F-box 1 (EBF1) is involved in cold tolerance in Arabidopsis; however, its exact roles in cold signaling in Brassica rapa remain uncertain. Herein, we demonstrated that EBF1 homologs are highly conserved in Brassica species, but their copy numbers are diverse, with some motifs being species specific. Cold treatment activated the expression of EBF1 homologs BrEBF1 and BrEBF2 in B. rapa; however, their expression schemas were diverse in different cold-resistant varieties of the plant. Subcellular localization analysis revealed that BrEBF1 is a nuclear-localized F-box protein, and cold treatment did not alter its localization but induced its degradation. BrEBF1 overexpression enhanced cold tolerance, reduced cold-induced ROS accumulation, and enhanced MPK3 and MPK6 kinase activity in Arabidopsis. Our study revealed that BrEBF1 positively regulates cold tolerance in B. rapa and that BrEBF1-regulated cold tolerance is associated with ROS scavenging and MPK3 and MPK6 kinase activity through the C-repeat binding factor pathway.


Assuntos
Arabidopsis , Brassica rapa , Brassica , Brassica rapa/genética , Arabidopsis/genética , Espécies Reativas de Oxigênio , Especificidade da Espécie
9.
J Plant Physiol ; 287: 154055, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37506405

RESUMO

Long noncoding RNAs (lncRNAs) play essential roles in numerous biological processes in plants, such as regulating the gene expression. However, only a few studies have looked into their potential functions in xylem development. High-throughput sequencing of P. euramericana 'Zhonglin46' developing and mature xylem was performed in this study. Through sequencing analysis, 14,028 putative lncRNA transcripts were identified, including 4525 differentially expressed lncRNAs (DELs). Additional research revealed that in mature xylem, a total of 2320 DELs were upregulated and 2205 were downregulated compared to developing xylem. Meanwhile, there were a total of 8122 differentially expressed mRNAs (DEMs) that were upregulated and 16,424 that were downregulated in mature xylem compared with developing xylem. The cis- and trans-target genes of DELs were analyzed for Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment, which indicated that these DELs participate in controlling the phenylpropanoid and lignin biosynthesis pathway as well as the starch and sucrose metabolism pathway. Among the cis-regulated DELs, LNC_006291, LNC_006292, and LNC_006532 all participate in regulating multiple HCT gene family membranes. As targets, POPTR_001G045900v3 (CCR2) and POPTR_018G063500v3 (SUS) both have only one cis-regulatory lncRNA, referred to as LNC_000057 and LNC_006212, respectively. Moreover, LNC_004484 and two DELs named LNC_008014 and LNC_010781 were revealed to be important nodes in the co-expression network of trans-lncRNAs and mRNAs associated to the lignin biosynthesis pathway and cellulose and xylan biosynthetic pathways, respectively. Finally, quantitative real-time PCR (qRT-PCR) was used to confirme 34 pairs of lncRNA-mRNA. Taken together, these findings may help to clarify the regulatory role that lncRNAs play in xylem development and wood formation.


Assuntos
Populus , RNA Longo não Codificante , RNA Mensageiro/genética , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Populus/genética , Lignina , Xilema/genética , Xilema/metabolismo , Redes Reguladoras de Genes , Perfilação da Expressão Gênica
10.
Bull Environ Contam Toxicol ; 89(4): 811-5, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22875286

RESUMO

Residual levels, distribution and possible sources of organochlorine pesticides (OCPs) in nine water column and suspended particulate matter (SPM) samples collected from Xiangshan Bay, East China Sea were investigated. Total OCPs concentrations in water column and SPM ranges from 2.88 to 34.72 ng/L and 2.47 to 29.94 ng/L, respectively, which exceed the US Environmental Protection Agency regulatory limits. Moreover, low ratio of α-HCH/γ-HCH and high ratios ß- and γ-HCH suggested the cocktail input pattern of fresh and weathered HCHs. Meanwhile, low ratio of (DDE + DDD)/DDT and high ratios p,p'- and o,p'-DDT reflected a "dicofol type DDT pollution" pattern.


Assuntos
Hidrocarbonetos Clorados/análise , Resíduos de Praguicidas/análise , Água do Mar/química , Poluentes Químicos da Água/análise , China , DDT/análise , Diclorodifenil Dicloroetileno/análise , Monitoramento Ambiental , Hexaclorocicloexano/análise , Oceanos e Mares , Poluição Química da Água/estatística & dados numéricos
11.
Nat Chem ; 14(11): 1233-1241, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36097055

RESUMO

The high efficiency of widely applied Noyori-type hydrogenation catalysts arises from the N-H moiety coordinated to a metal centre, which stabilizes rate-determining transition states through hydrogen-bonding interactions. It was proposed that a higher efficiency could be achieved by substituting an N-M' group (M' = alkali metals) for the N-H moiety using a large excess of metal alkoxides (M'OR); however, such a metal-hydride amidate intermediate has not yet been isolated. Here we present the synthesis, isolation and reactivity of a metal-hydride amidate complex (HMn-NLi). Kinetic studies show that the rate of hydride transfer from HMn-NLi to a ketone is 24-fold higher than that of the corresponding amino metal-hydride complex (HMn-NH). Moreover, the hydrogenation of N-alkyl-substituted aldimines was realized using HMn-NLi as the active catalyst, whereas HMn-NH is much less effective. These results highlight the superiority of M/NM' bifunctional catalysis over the classic M/NH bifunctional catalysis for hydrogenation reactions.


Assuntos
Complexos de Coordenação , Manganês , Cinética , Catálise , Hidrogenação , Complexos de Coordenação/química , Metais
12.
Front Genet ; 13: 871825, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35559032

RESUMO

Winter rapeseed (Brassica rapa L.) is an important oilseed crop in northwest China. Freezing stress severely limits its production and geographical distribution, and frequent extreme freezing events caused by climate change are increasing the chances of winter freeze-injury. However, the underlying mechanism of B. rapa response to freezing stress remains elusive. Here, B. rapa genome (v3.0) was used as a reference for the comparative transcriptomic analysis of Longyou 6 and Tianyou 2 (strong and weak cold tolerance, respectively) under different freezing stress. Before and after freezing stress, 5,982 and 11,630 unique differentially expressed genes (DEGs) between two cultivars were identified, respectively. After freezing stress, the GO terms in Tianyou 2 were mainly involved in "macromolecule biosynthetic process", and those in Longyou 6 were involved in "response to stimulus" and "oxidoreductase activity". Morphological and physiological results indicated that Longyou 6 retained a higher basal freezing resistance than Tinayou 2, and that cold acclimation could strengthen the basal freezing resistance. Freezing stress could activate the MAPK signal cascades, and the phosphorylation level of Longyou 6 showed a higher increase in response to freezing treatment than Tianyou 2. Based on our findings, it was speculated that the cell membrane of B. rapa perceives external signals under freezing stress, which are then transmitted to the nucleus through the cold-activated MAPK cascades and Ca2+-related protein kinase pathway, thus leading to activation of downstream target genes to enhance the freezing resistance of B. rapa.

13.
Zhongguo Dang Dai Er Ke Za Zhi ; 13(7): 539-42, 2011 Jul.
Artigo em Zh | MEDLINE | ID: mdl-21752317

RESUMO

OBJECTIVE: To study the distribution characteristics of adiponectin gene +45 single nucleotide polymorphisms (SNP) in Chinese children, and to determine the role of adiponectin gene +45 polymorphisms in the pathogenesis of childhood obesity. METHODS: A total of 147 Chinese obese and 118 healthy children were randomly selected and enrolled to identify adiponectin gene SNP+45 polymorphism by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. Plasma adiponectin levels were determined using ELISA. Waist circumference (WC), waist to hip ratio (WHR), percentage of body fat (%BF), systolic blood pressure (SBP), diastolic blood pressure (DBP), fasting plasma glucose (FPG), serum triglycerides (TG), total cholesterol (TC), high density lipoprotein-cholesterol (HDL-C), low density lipoprotein-cholesterol (LDL-C), plasma fasting insulin (FINS), and homeostasis model assessment of insulin resistance (HOMA-IR) were measured. RESULTS: The allelic frequency of adiponectin gene SNP+45 in children with obesity and healthy controls were 40.5% and 25.4%, respectively. There were significant differences in the distribution of genotypes and the allelic frequency between the two groups (P<0.05). The plasma adiponectin levels were significantly higher, in contrast, %BF, HOMA-IR, TC and LDL-C levels were significantly lower in obese children with TT genotype than those in obese children with TG or GG genotype. CONCLUSIONS: The adiponectin gene SNP+45 polymorphism may be associated with pathogenesis of obesity in children. T→G variance may be associated an increased risk of childhood obesity and result in a decreased level of adiponectin.


Assuntos
Adiponectina/genética , Obesidade/genética , Polimorfismo de Nucleotídeo Único , Adolescente , Glicemia/análise , Pressão Sanguínea , Criança , Feminino , Genótipo , Humanos , Lipídeos/sangue , Masculino , Obesidade/sangue , Obesidade/etiologia
14.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 35(9): 915-20, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20871154

RESUMO

OBJECTIVE: To investigate the distribution characteristics of protein tyrosine phosphatase 1B (PTP1B) gene IVS6+G82A and Pro303Pro polymorphisms in Chinese children and determine the effect of PTP1B gene IVS6+G82A and Pro303Pro polymorphisms on the pathogenesis of childhood obesity. METHODS: A total of 147 Chinese obese and 118 healthy children were randomly selected and enrolled to identify IVS6+G82A and Pro303Pro genotypes by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. Waist circumference (WC), waist to hip ratio (WHR), percentage of body fat (%BF),systolic blood pressure (SBP), diastolic blood pressure (DBP), fasting plasma glucose (FPG), serum triglycerides (TG), total cholesterol (TC), high density lipoprotein-cholesterol (HDL-C), low density lipoprotein-cholesterol (LDL-C), plasma fasting insulin (FINS), homeostasis model assessment for insulin resistance (HOMA-IR), and plasma leptin were examined. RESULTS: The allele frequencies of IVS6+G82A and Pro303Pro were 59.5% and 19.4% in obese children, and 53.4% and 11.0% in healthy children, respectively. There were significant differences in allele frequencies of Pro303Pro polymorphism between the obese and the control group. Pro303Pro polymorphism was associated with body mass index, WC, TG, and LDL-C in the obese subjects. There was not difference in the genotype distributions or allele frequencies of IVS6+G82A polymorphism between the obese and the control group. Further analysis showed no association between the genotypes of IVS6+G82A and clinical characteristics in the obese subjects. The linkage disequilibrium analysis for IVS6+G82A and Pro303Pro (D': 0.441, r2: 0.027) was weak. CONCLUSION: PTP1B gene Pro303Pro polymorphism might be associated with the pathogenesis of obesity in children and could affect the lipid metabolism in Chinese obese children.


Assuntos
Obesidade/genética , Polimorfismo Genético , Proteína Tirosina Fosfatase não Receptora Tipo 1/genética , Estudos de Casos e Controles , Criança , China , Feminino , Humanos , Leptina/sangue , Masculino , Obesidade/sangue , Reação em Cadeia da Polimerase/métodos , Polimorfismo de Fragmento de Restrição
15.
Org Lett ; 22(7): 2724-2729, 2020 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-32202804

RESUMO

Herein, we report a nickel-catalyzed asymmetric two-component reductive dicarbofunctionalization of aryl iodide-tethered unactivated alkenes using benzyl chlorides as the challenging coupling partner. This arylbenzylation reaction enables the efficient synthesis of diverse benzene-fused cyclic compounds bearing a quaternary stereocenter with a high tolerance of sensitive functionalities in highly enantioselective manner. The preliminary mechanistic investigations suggest a radical chain reaction mechanism.

16.
Zhongguo Dang Dai Er Ke Za Zhi ; 11(9): 745-8, 2009 Sep.
Artigo em Zh | MEDLINE | ID: mdl-19755025

RESUMO

OBJECTIVE: To investigate serum leptin level and its relationship with bone mineral density in obese children from Changsha City. METHODS: One hundred and nineteen obese children and 103 normal children aged 7 to 12 years from five primary schools of Changsha City were enrolled. Obesity was assessed based on the body mass index (BMI). Dual energy X-ray absorptiometry (DEXA) was used to determine bone mineral density (BMD) and body composition. Serum leptin level was measured using enzyme-linked immunosorbent assay (ELISA). RESULTS: The obesity group had higher height, weight, BMI, waist circumference and waist to hip ratio (WHR) compared with the normal group (p<0.01). BMD, bone mineral content (BMC), lean mass (LM), fat mass (FM), percentage of body fat (%BF) and leptin concentration in the obesity group were significantly higher than those in the normal group (p<0.01). Serum leptin level was positively correlated with BMD, BMC, LM and FM (r=0.528-0.903, p<0.01). Multiple stepwise regression analysis indicated that BMI and %BF were independent influencing factors for serum leptin level. CONCLUSIONS: Obese children have higher serum leptin level. Serum leptin concentration is significantly correlated with BMD and body composition. BMI and %BF are independent influencing factors for serum leptin level in children.


Assuntos
Densidade Óssea , Leptina/sangue , Obesidade/sangue , Composição Corporal , Criança , Feminino , Humanos , Masculino , Análise de Regressão , Caracteres Sexuais
17.
Org Lett ; 21(18): 7602-7608, 2019 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-31479278

RESUMO

Reported is a nickel-catalyzed reductive arylalkylation of unactivated alkenes tethered to aryl iodides with redox active N-hydroxyphthalimide esters as the alkyl source through successful merging of migratory insertion and decarboxylative cross-coupling in a cascade. This new method avoids the use of pregenerated organometallic reagents and thus enables the synthesis of diverse benzene-fused carbo- and heterocyclic compounds with high tolerance of a wide range of functional groups.

18.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 32(1): 127-31, 2007 Feb.
Artigo em Zh | MEDLINE | ID: mdl-17344602

RESUMO

OBJECTIVE: To evaluate the effects of bispectral index(BIS) and auditory evoked potentials index(AEPindex) monitoring on the depth of anesthesia in inhalation of isoflurane and target-controlled infusion(TCI) of propofol, and to observe the changes of BIS and AEPindex. METHODS: Fourty ASA physical status I - II patients undergoing selective abdominal operations were divided into 2 groups randomly: Group I1(the end-tidal isoflurane concentration was 0.6 MAC, n=20) and Group I2(the end-tidal isoflurane concentration was 1.0 MAC, n=20). Anesthesia was induced with proprofol and vecuroninm. After the tracheal intubation, the patients were ventilated with 0.6/1.0 MAC isoflurane in pure oxygen, and after 20 minutes, propofol was administered with TCI according to the different target plasma concentrations from 1.0 g/mL to 3.0 g/mL(increasing 0.5 g/mL each time). The changes of MAP, HR, BIS and AEPindex were recorded simultaneously. RESULTS: There was no close correlation between MAP, HR and the end-tidal isoflurane concentration, target plasma concentration of propofol. The correlation coefficiencies between BIS, AEPindex and the end-tidal isoflurane concentration were -0.757, -0.819 and -0.832, -0.878 (P<0.001), respectively; those between BIS, AEPindex and the target plasma concentration of propofol were -0.932, -0.888 and -0.920, -0.923 (P<0.001). The correlation coefficiencies between BIS, AEPindex and the stimulation of endotracheal intubation were -0.728 and 0.544, respectively; however, there was no close correlation between BIS , AEPindex and the stimulation of skin incision, and exploration. CONCLUSION: BIS and AEPindex are reliable parameters to monitor the depth of anesthesia of isoflurane and propofol combined anesthesia; and in response to the stimulation of tracheal intubation, AEPindex is better than BIS, but BIS and AEPindex can not be used to predict the cardiovascular reaction of skin incision and exploration.


Assuntos
Anestésicos Combinados/administração & dosagem , Anestésicos Inalatórios/administração & dosagem , Anestésicos Intravenosos/administração & dosagem , Potenciais Evocados Auditivos/efeitos dos fármacos , Abdome/cirurgia , Anestesia/métodos , Pressão Sanguínea/efeitos dos fármacos , Eletroencefalografia , Feminino , Frequência Cardíaca/efeitos dos fármacos , Humanos , Isoflurano/administração & dosagem , Masculino , Propofol/administração & dosagem , Brometo de Vecurônio/administração & dosagem
19.
Neural Regen Res ; 12(2): 250-258, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28400807

RESUMO

Functional magnetic resonance imaging has been widely used to investigate the effects of acupuncture on neural activity. However, most functional magnetic resonance imaging studies have focused on acute changes in brain activation induced by acupuncture. Thus, the time course of the therapeutic effects of acupuncture remains unclear. In this study, 32 patients with amnestic mild cognitive impairment were randomly divided into two groups, where they received either Tiaoshen Yizhi acupuncture or sham acupoint acupuncture. The needles were either twirled at Tiaoshen Yizhi acupoints, including Sishencong (EX-HN1), Yintang (EX-HN3), Neiguan (PC6), Taixi (KI3), Fenglong (ST40), and Taichong (LR3), or at related sham acupoints at a depth of approximately 15 mm, an angle of ± 60°, and a rate of approximately 120 times per minute. Acupuncture was conducted for 4 consecutive weeks, five times per week, on weekdays. Resting-state functional magnetic resonance imaging indicated that connections between cognition-related regions such as the insula, dorsolateral prefrontal cortex, hippocampus, thalamus, inferior parietal lobule, and anterior cingulate cortex increased after acupuncture at Tiaoshen Yizhi acupoints. The insula, dorsolateral prefrontal cortex, and hippocampus acted as central brain hubs. Patients in the Tiaoshen Yizhi group exhibited improved cognitive performance after acupuncture. In the sham acupoint acupuncture group, connections between brain regions were dispersed, and we found no differences in cognitive function following the treatment. These results indicate that acupuncture at Tiaoshen Yizhi acupoints can regulate brain networks by increasing connectivity between cognition-related regions, thereby improving cognitive function in patients with mild cognitive impairment.

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