Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 17 de 17
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
PeerJ ; 12: e17137, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38529310

RESUMO

Gleditsia sinensis, commonly known as Chinese Zaojiao, has important economic value and medicinal compounds in its fruits and thorns, making it widely cultivated artificially in China. However, the available literature on the impact of waterlogging on the growth of G. sinensis seedlings and the accumulation of metabolite compounds in its thorns is limited. To address this knowledge gap, G. sinensis seedlings were planted in soil supplemented with pindstrup substrate, which enhances the water-holding capacity of the soil. The analyses of morphological traits and nutrient elements in one-year-old G. sinensis seedlings grown naturally under ambient conditions and metabolite accumulation in its thorns were conducted. The results showed that the waterlogged soil significantly diminished the height, fresh weight, and dry weight of seedling roots and stems (P < 0.05). Furthermore, waterlogging hindered the uptake of iron (Fe) and manganese (Mn), as well as the transport of potassium (K). The identified metabolites within the thorns were categorized into 16 distinct groups. Relative to the control soil, fatty acids and derivatives were the most down-regulated metabolites in the waterlogged soil, accounting for 40.58% of the total metabolites, followed by lignans (38.71%), phenolic acids (34.48%), saccharides and alcohols (34.15%), steroids (16.67%), alkaloids (12.24%), flavonoids (9.28%), and glycerophospholipids (7.41%). Conversely, nucleotides and derivatives experienced the greatest up-regulation in the waterlogged soil, accounting for 50.00% of the total metabolites. In conclusion, waterlogging negatively impacted the growth of G. sinensis seedlings and inhibited the accumulation of metabolites. Hence, when considering the accumulation of secondary metabolites such as lignans and phenolic acids, appropriate management of soil moisture levels should be taken into account.


Assuntos
Gleditsia , Lignanas , Plântula , Lignanas/metabolismo , Gleditsia/química , Extratos Vegetais/metabolismo , Raízes de Plantas
2.
Heliyon ; 10(6): e27802, 2024 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-38496869

RESUMO

rs2736098 is a synonymous polymorphism in TERT (telomerase reverse transcriptase), an enzyme involved in tumor onset of multiple tissues, and should play no roles in carcinogenesis. However, a search in cancer somatic mutation database indicated that the mutation frequency at rs2736098 is much higher than the average one for TERT. Moreover, there are significant H3K4me1 and H3K27Ac signals, two universal histone modifications for active enhancers, surrounding rs2736098. Therefore, we hypothesized that rs2736098 might be within an enhancer region, regulate TERT expression and influence cancer risk. Through luciferase assay, it was verified that the enhancer activity of rs2736098C allele is significantly higher than that of T in multiple tissues. Transfection of plasmids containing TERT coding region with two different alleles indicated that rs2736098C allele can induce a significantly higher TERT expression than T. By chromatin immunoprecipitation, it was observed that the fragment spanning rs2736098 can interact with USF1 (upstream transcription factor 1). The two alleles of rs2736098 present evidently different binding affinity with nuclear proteins. Database and literature search indicated that rs2736098 is significantly associated with carcinogenesis in multiple tissues and count of multiple cell types. All these facts indicated that rs2736098 is also an oncogenic polymorphism and plays important role in cell proliferation.

3.
Physiol Plant ; 176(1): e14211, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38351399

RESUMO

Alpine Rhododendron species are prominent constituents and renowned ornamental plants in alpine ecosystems. Consequently, evaluating the genetic variation in embolism resistance within the genus Rhododendron and predicting their adaptability to future climate change is important. Nevertheless, the assessment of embolism resistance in Rhododendron species remains limited. This investigation aimed to examine leaf vulnerability to embolism across ten alpine Rhododendron species, which are frequently employed as ornamental species in Rhododendron forests in Southwest China. The study analyzed the correlation between embolism resistance and various morphological traits, while also conducting water control experiments to evaluate the relationship between embolism resistance and drought resistance. The outcomes indicated pronounced variations in leaf vulnerability to embolism among species, as reflected by the water potential at 50% of embolized pixels (P50 ). Furthermore, the leaf P50 exhibited a significant positive correlation with vessel diameter (D) (R2 = 0.44, P = 0.03) and vessel wall span (b) (R2 = 0.64, P = 0.005), while displaying a significant negative correlation with vessel reinforcement ((t/b)2 ) (R2 = 0.67, P = 0.004). These findings underscore the reliability of selecting species based on embolism vulnerability to preserve the diversity of alpine ecosystems and foster resilience to climate change.


Assuntos
Embolia , Rhododendron , Ecossistema , Reprodutibilidade dos Testes , Folhas de Planta , Água , China
4.
Ann Hum Genet ; 88(2): 126-137, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-37846608

RESUMO

INTRODUCTION: Prostate cancer is one of the most common cancer types in males and rs12621278:A > G has been suggested to be associated with this disease by previous genome-wide association studies. One thousand genomes project data analysis indicated that rs12621278:A > G is within two long-core haplotypes. However, the origin, causal variant(s), and molecular function of these haplotypes were remaining unclear. MATERIALS AND METHODS: Population genetics analysis and functional genomics work was performed for this locus. RESULTS: Phylogeny analysis verified that the rare haplotype is derived from Neanderthal introgression. Genome annotation suggested that three genetic variants in the core haplotypes, rs116108611:G > A, rs139972066:AAAAAAAA > AAAAAAAAA, and rs3835124:ATTTATT > ATT, are located in functional regions. Luciferase assay indicated that rs139972066:AAAAAAAA > AAAAAAAAA and rs116108611:G > A are not able to alter ITGA6 (integrin alpha 6) and ITGA6 antisense RNA 1 expression, respectively. In contrast, rs3835124:ATTTATT > ATT can significantly influence PDK1 (pyruvate dehydrogenase kinase 1) expression, which was verified by expression quantitative trait locus analysis. This genetic variant can alter transcription factor cut like homeobox 1 interaction efficiency. The introgressed haplotype was observed to be subject to positive selection in East Asian populations. The molecular function of the haplotype suggested that Neanderthal should be with lower PDK1 expression and further different energy homeostasis from modern human. CONCLUSION: This study provided new insight into the contribution of Neanderthal introgression to human phenotypes.


Assuntos
Homem de Neandertal , Neoplasias , Humanos , Animais , Homem de Neandertal/genética , Estudo de Associação Genômica Ampla , Genética Populacional , Filogenia , Haplótipos , Genoma Humano , Neoplasias/genética
5.
Int J Mol Sci ; 24(16)2023 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-37628875

RESUMO

In recent years, petal blight disease caused by pathogens has become increasingly epidemic in Rhododendron. Breeding disease-resistant rhododendron is considered to be a more environmentally friendly strategy than is the use of chemical reagents. In this study, we aimed to investigate the response mechanisms of rhododendron varieties to petal blight, using transcriptomics and metabolomics analyses. Specifically, we monitored changes in gene expression and metabolite accumulation in Rhododendron 'Xiaotaohong' petals infected with the Alternaria sp. strain (MR-9). The infection of MR-9 led to the development of petal blight and induced significant changes in gene transcription. Differentially expressed genes (DEGs) were predominantly enriched in the plant-pathogen interaction pathway. These DEGs were involved in carrying out stress responses, with genes associated with H2O2 production being up-regulated during the early and late stages of infection. Correspondingly, H2O2 accumulation was detected in the vicinity of the blight lesions. In addition, defense-related genes, including PR and FRK, exhibited significant up-regulated expression during the infection by MR-9. In the late stage of the infection, we also observed significant changes in differentially abundant metabolites (DAMs), including flavonoids, alkaloids, phenols, and terpenes. Notably, the levels of euscaphic acid, ganoderol A, (-)-cinchonidine, and theophylline in infected petals were 21.8, 8.5, 4.5, and 4.3 times higher, respectively, compared to the control. Our results suggest that H2O2, defense-related genes, and DAM accumulation are involved in the complex response mechanisms of Rhododendron 'Xiaotaohong' petals to MR-9 infection. These insights provide a deeper understanding of the pathogenesis of petal blight disease and may have practical implications for developing disease-resistant rhododendron varieties.


Assuntos
Ceratoconjuntivite , Rhododendron , Transcriptoma , Alternaria , Rhododendron/genética , Peróxido de Hidrogênio , Melhoramento Vegetal , Metabolômica
6.
Exp Ther Med ; 26(3): 451, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37614425

RESUMO

Asthma is a complex disease, often with evident genetic predisposition; for example, the single-nucleotide polymorphism (SNP) rs7130588 was significantly associated with asthma by genome-wide association study (GWAS). Analysis of 1000 Genomes Project data suggests that there is another SNP, rs6592645, in complete linkage disequilibrium with rs7130588 and should present the same signal in GWAS. However, the causal SNP and the mechanism for the association between rs7130588 and asthma remain to be elucidated. In the presents study, results from dual-luciferase assays indicated that the A/G alleles of rs7130588 failed to present significantly different reporter gene expression. By contrast, A allele of rs6592645 presented a significant increase in relative luciferase activity than G allele, thus suggesting that rs6592645 may be a causal SNP. Using chromosome conformation capture, the enhancer region containing rs6592645 was observed to interact with promoter region of leucine-rich repeat-containing 32 (LRRC32). Gene expression quantification suggested that LRRC32 expression is significantly increased in lung tissue of patients with asthma and is dependent on the genotype of this locus, thus verifying that LRRC32 may be involved in asthma onset and that rs6592645 can regulate LRRC32 expression. Through chromatin immunoprecipitation, transcription factor 3 (TCF3) was identified to bind to rs6592645 surrounding region and the interaction between TCF3 and rs6592645 surrounding region was investigated. Results from the present study may improve our understanding of the mechanism by which the genetic variation in this locus might influence asthma susceptibility.

7.
Anticancer Agents Med Chem ; 23(16): 1829-1837, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37259217

RESUMO

INTRODUCTION: Small cell lung cancer (SCLC) is featured by a high TP53 mutant rate. Our previous research found that arsenic trioxide (As2O3) could significantly inhibit the growth and metastasis of SCLC. Studies have shown that the degradation of mutant p53 mediated by murine double minute 2 (MDM2) can be induced by As2O3, which probably contributes to the inhibition of SCLC, but the detailed mechanism is still unclear. We aimed to testify that As2O3 can inhibit the growth of SCLC cells by degrading mutant p53 protein via binding to MDM2. METHODS: CCK-8 assay, cell cycle analysis, and western blot of apoptosis markers were used to evaluate the inhibitory effect of As2O3 on NCI-H446 cells (containing mutant p53) and NCI-H1299 cells (p53 null). The effects of As2O3 on p53 and its downstream proteins were identified by western blot using mut-p53-knockdown and overexpressed cell models. MDM2-knockdown cell models were constructed, and western blot, co-IP of mut-p53, and ubiquitin were carried out to explore the mediating effect of MDM2 in As2O3 induced mut-p53 degradation. RESULTS: As2O3 inhibited proliferation and induced cell cycle arrest and apoptosis of SCLC cells in a dose- and timedependent manner. After mut-p53 knockdown or overexpressed, the inhibitory effect of As2O3 was dampened or enhanced. Additionally, As2O3-induced mut-p53 ubiquitination was significantly weakened after MDM2 knockdown. CONCLUSION: As2O3 could inhibit SCLC cells by inhibiting proliferation and inducing cell cycle arrest and apoptosis. These inhibitory effects were achieved at least in part by upregulating MDM2, which, in turn, promotes ubiquitination and degradation of mut-p53.


Assuntos
Antineoplásicos , Arsenicais , Neoplasias Pulmonares , Carcinoma de Pequenas Células do Pulmão , Humanos , Animais , Camundongos , Trióxido de Arsênio/farmacologia , Carcinoma de Pequenas Células do Pulmão/tratamento farmacológico , Carcinoma de Pequenas Células do Pulmão/patologia , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Óxidos/farmacologia , Óxidos/metabolismo , Óxidos/uso terapêutico , Arsenicais/farmacologia , Arsenicais/metabolismo , Arsenicais/uso terapêutico , Linhagem Celular Tumoral , Apoptose , Neoplasias Pulmonares/patologia , Proliferação de Células , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Proteínas Proto-Oncogênicas c-mdm2/farmacologia , Proteínas Proto-Oncogênicas c-mdm2/uso terapêutico
8.
PLoS One ; 18(4): e0284347, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37058478

RESUMO

Lung cancer is a malignant tumor with high rates of mortality and shows significant hereditary predisposition. Previous genome-wide association studies suggest that rs748404, located at promoter of TGM5 (transglutaminase 5), is associated with lung carcinoma. By analysis of 1000 genomes project data for three representative populations in the world, another five SNPs are identified to be in strong linkage disequilibrium with rs748404, thus suggesting that they may also be associated with lung carcinoma risk. However, it is ambiguous about the actually causal SNP(s) and the mechanism for the association. Dual-luciferase assay indicates that the functional SNPs are not rs748404, rs12911132 or rs35535629 but another three SNPs (rs66651343, rs12909095 and rs17779494) in lung cell. By chromosome conformation capture, it is disclosed that the enhancer encompassing the two SNPs, rs66651343 and rs12909095, can interact with the promoter of CCNDBP1 (cyclin D1 binding protein 1). RNA-seq data analysis indicates that CCNDBP1 expression is dependent on the genotype of these two SNPs. Chromatin immunoprecipitation assay suggests that the fragments spanning rs66651343 and rs12909095 can bind with the transcription factors, cut like homeobox 1 and SRY-box transcription factor 9, respectively. Our results establish the connection between genetic variations at this locus and lung cancer susceptibility.


Assuntos
Carcinoma , Neoplasias Pulmonares , Humanos , Carcinoma/patologia , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Genótipo , Pulmão/patologia , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Polimorfismo de Nucleotídeo Único
9.
Oncol Lett ; 25(2): 76, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36742366

RESUMO

Breast cancer is the cancer type with the highest morbidity rates in women, and previous genome-wide association studies (GWASs) have suggested that the single nucleotide polymorphism (SNP) rs1011970 is significantly associated with this disease. An analysis of data from the 1000 Genomes Project demonstrated that there is an SNP, rs77283072, in almost complete linkage disequilibrium with rs1011970, which should therefore present the same signal in a GWAS. However, the actual causal SNP and its associated underlying mechanism have yet to be elucidated. Therefore, the present study evaluated the role of rs77283072 in terms of its association with breast cancer. A dual-luciferase assay was performed, which demonstrated that the two alleles of rs1011970 did not exhibit significantly different reporter gene activity. However, the A allele of rs77283072 exhibited a significant increase in relative luciferase activity compared with the G allele, which suggested that rs77283072 was the causal SNP for breast cancer. Chromosome conformation capture demonstrated that the enhancer containing rs77283072 interacted with the promoter of cyclin-dependent kinase inhibitor 2A (CDKN2A). Furthermore, expression quantitative trait locus analysis demonstrated that the expression of CDKN2A was dependent on the genotype of rs77283072. Taken together, the findings of the present study provided novel insights into the mechanism underlying how the genetic variation in this locus was able to influence breast cancer susceptibility and further the treatment for this disease.

10.
Int Immunopharmacol ; 117: 109899, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36827926

RESUMO

Drug-resistant advanced lung adenocarcinoma (LUAD) is an aggressive malignancy with limited treatment options. A therapeutic strategy for drug-resistant LUAD is to target the tumor associated macrophages (TAMs), because they play an important role in tumor immune escape, progression and metastasis. In this study, we conducted in vivo and in vitro investigation of the inhibitory effect of arsenic trioxide (ATO) on polarization of TAMs educated by LUAD. We found that ATO at a concentration of 4 µM disrupted the Notch-dependent positive feedback loop between LUAD and TAMs. In this loop, ATO inhibited the expression of Jagged1 and Notch1 in LUAD and suppressed M2 polarization via down-regulating Notch-dependent paracrine of CCL2 and IL1ß. As a result, the secretion of M2-derived TGF-ß1 decreased, thus inducing inhibitions of LUAD proliferation, migration, invasion, colony formation and epithelial-mesenchymal transition. In xenograft mouse models, ATO significantly inhibited tumor growth and down-regulated infiltration of M2-like TAMs in tumor tissues. In clinical LUAD biopsy samples, high Jagged1/Notch1 expression positively correlated with tumor-infiltrated M2-like TAMs, leading to poor prognosis. In conclusion, our results identified a novel tumor immunomodulating function for ATO, which can inhibit the polarization of M2-type TAMs to exert anti-tumor effects in the tumor microenvironment. Our results demonstrated the translational potential of repurposing ATO to target TAMs for lung adenocarcinoma treatment.


Assuntos
Adenocarcinoma de Pulmão , Neoplasias Pulmonares , Humanos , Animais , Camundongos , Macrófagos Associados a Tumor/metabolismo , Trióxido de Arsênio/uso terapêutico , Trióxido de Arsênio/farmacologia , Macrófagos , Transdução de Sinais , Adenocarcinoma de Pulmão/metabolismo , Neoplasias Pulmonares/patologia , Linhagem Celular Tumoral , Microambiente Tumoral
11.
Sci Rep ; 13(1): 3134, 2023 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-36823244

RESUMO

Our previous work identified one region upstream human UGT2B4 (UDP glucuronosyltransferase family 2 member B4) which is associated with breast cancer and under balancing selection. However, the distribution, functional variation and molecular mechanism underlying breast cancer and balancing selection remain unclear. In current study, the two haplotypes with deep divergence are described by analyzing 1000 genomes project data and observed to be with high frequencies in all human populations. Through population genetics analysis and genome annotation, the potential functional region is identified and verified by reporter gene assay. Further mutagenesis indicates that the functional mutations are rs66862535 and rs68096061. Both SNPs can alter the interaction efficiency of transcription factor POU2F1 (POU class 2 homeobox 1). Through chromosome conformation capture, it is identified that the enhancer containing these two SNPs can interact with UGT2B4 promoter. Expression quantitative trait loci analysis indicates that UGT2B4 expression is dependent on the genotype of this locus. The common haplotype in human is lost in four genomes of archaic hominins, which suggests that Neanderthal and Denisovan should present relatively lower UGT2B4 expression and further higher steroid hormone level. This study provides new insight into the contribution of ancient population structure to human phenotypes.


Assuntos
Genética Populacional , Glucuronosiltransferase , Animais , Feminino , Humanos , Neoplasias da Mama/genética , Genoma Humano , Glucuronosiltransferase/genética , Hominidae/genética , Homem de Neandertal/genética , Fenótipo
12.
J Cancer Res Clin Oncol ; 149(8): 4515-4522, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36131156

RESUMO

PURPOSE: Lung cancer is a malignant tumor with obvious genetic predisposition. Association studies have proposed that rs2853677, a SNP localizing at intron region of TERT (telomerase reverse transcriptase), is significantly associated with TERT expression, telomere length and eventually lung cancer risk. However, functional genomics work indicates that rs2853677 is not with the ability to alter gene expression. All these facts make us hypothesize that some other genetic variation(s) are in linkage disequilibrium (LD) with rs2853677 and influence TERT expression. METHODS: LD pattern in rs2853677 nearby region was analyzed based on 1000 genomes data for three representative populations in the world and functional genomics research was performed for this locus. RESULTS: Only one SNP, rs2736099, is in strong LD with rs2853677 in East Asian. Dual-luciferase reporter assay verifies that rs2736099 can regulate gene expression and should be the causal SNP for this disease. Through chromosome conformation capture assay, it is disclosed that the enhancer surrounding rs2736099 can interact with TERT promoter. Through chromatin immunoprecipitation, the transcription factor SP1 (Sp1 transcription factor) is recognized for the chromatin segment spanning rs2736099. CONCLUSIONS: Our results provide the missing piece between genetic variation at this locus and lung cancer risk, which is also applied to tumorigenesis in other tissues and cell proliferation.


Assuntos
Neoplasias Pulmonares , Telomerase , Humanos , Neoplasias Pulmonares/genética , Predisposição Genética para Doença , Pulmão , Telomerase/genética , Carcinogênese , Transformação Celular Neoplásica , Proliferação de Células/genética , Polimorfismo de Nucleotídeo Único
13.
Curr Cancer Drug Targets ; 22(10): 854-864, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35770414

RESUMO

BACKGROUND: Anti-angiogenesis therapy mostly aimed at targeting vascular endothelial growth factor (VEGF) and its receptors have been widely applied to lung cancer. However, the improvement in the patient's overall survival remains dissatisfying. Previously, we demonstrated that arsenic trioxide (As2O3) exerts an anti-lung cancer effect through anti-angiogenesis, but the details of the mechanism in play remain unclear. Herein, we focused on the calcineurin-NFAT pathway, downstream of VEGF, and its endogenous inhibitor DSCR1. OBJECTIVE: To demonstrate the mechanism of As2O3 restraining lung cancer growth and metastasis by blocking the calcineurin-NFAT pathway by upregulating DSCR1. METHODS: We constructed xenografts and metastasis models based on wild-type (WT) and DSCR1 knockout (DSCR1-/-) mice, and carried out qPCR, Western blot, immunohistochemistry, in vivo imaging and calculated microvessel density to evaluate the effects of As2O3 on angiogenesis, tumor growth, metastasis, and the protein expression levels of DSCR1 and calcineurin-NFAT pathway-related molecules. RESULTS: As2O3 inhibited tumor growth and metastasis, reduced microvessel formation, and induced vascular lumen malformation in WT mice. At the protein level, As2O3 upregulated DSCR1, downregulated NFAT2 and its downstream molecules, but had no effect on calcineurin A. However, in DSCR1-/- mice, the above-mentioned effects of As2O3 were abolished. CONCLUSION: As2O3 can suppress lung cancer growth and metastasis through anti-angiogenesis effects by blocking the calcineurin-NFAT pathway by upregulating DSCR1. The results shed light on the antitumor mechanism of As2O3 and are a step forward in the identification of As2O3 as a new drug in the treatment of lung cancer.


Assuntos
Antineoplásicos , Trióxido de Arsênio , Calcineurina , Neoplasias Pulmonares , Fatores de Transcrição NFATC , Inibidores da Angiogênese , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Trióxido de Arsênio/farmacologia , Trióxido de Arsênio/uso terapêutico , Calcineurina/metabolismo , Proteínas de Ligação ao Cálcio/genética , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , Camundongos , Proteínas Musculares/genética , Fatores de Transcrição NFATC/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Fatores de Crescimento do Endotélio Vascular/metabolismo
14.
Ying Yong Sheng Tai Xue Bao ; 32(6): 2180-2190, 2021 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-34212624

RESUMO

Due to its vulnerability and anthropogenic disturbance, ecological problems in karst areas are prominent, such as vegetation destruction, soil erosion, and rocky desertification. Comprehensive analysis of ecological vulnerability and influencing factors in karst areas can provide scientific support for regional ecological restoration and environmental governance. With Guangnan County, a typical karst region in southeastern Yunnan, as an example, we constructed a karst regional eco-environmental vulnerability assessment index system from the perspective of natural and factitious factors. We used SPCA to assess the ecological vulnerability in 2000, 2010 and 2018. We further analyzed the temporal and spatial variations and explored its influencing factors by using geographic detectors. From 2000 to 2018, the changes of overall fragility were small, but the degree of fragility had been intensifying. The grade of ecological vulnerability was mainly slight fragile. The area with mild, moderate and severe fragility was increasing, while the area of extremely fragile showed no change. Guangnan County had a higher ecological vulnerability in the south of "Zhetu-Liancheng-Yangliujing-Banbang", and lower in the north. The spatial agglomeration effect of vulnerability was strong in this county. The north part of Guangnan was vulnerable low-low agglomeration areas, while the southwest and southeast parts were in high-fragility-high agglomeration areas. The implementation of ecological engineering was conducive to the improvement of regional ecological fragility, while the disturbance of human activities further deteriorated ecological fragility. The area proportion of rocky desertification and stratum lithology had stronger influence on ecological fragility of the karst area. The most important influencing factor of the karst ecological fragility was the development of karst carbonate rocks.


Assuntos
Conservação dos Recursos Naturais , Ecossistema , China , Política Ambiental , Atividades Humanas , Humanos
15.
Org Lett ; 19(14): 3943-3946, 2017 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-28703601

RESUMO

A novel and convenient strategy for the enantioselective synthesis of γ-lactam derivatives via N-heterocyclic carbene catalyzed formal [3 + 2] annulation of enals with 2-aminoacrylates is disclosed. This activation mode provides a complementary approach to the synthesis of various γ-lactam derivatives in good yields with excellent diastereo- and enantioselectivities. In this process, two consecutive stereocenters are constructed, and a quaternary carbon center is also established.

16.
Chem Commun (Camb) ; 53(44): 5985-5988, 2017 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-28513660

RESUMO

A strategy for the NHC-catalyzed synthesis of dihydropyridinones and spirooxindoles has been developed via [3+3] annulation reactions of enals or isatin-derived enals with 2-aminoacrylates under oxidative conditions. In this efficient strategy, the 2-aminoacrylates served as nucleophiles. Modifying the standard base switched the carbon-carbon double bond formation from 5,6-positions to 3,4-positions to generate 5,6-dihydropyridinones and 3,4-dihydropyridinones, respectively. Meanwhile, a diverse set of spirooxindole derivatives were also synthesized in good to excellent yields.

17.
Zhonghua Yu Fang Yi Xue Za Zhi ; 45(1): 68-72, 2011 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-21418823

RESUMO

OBJECTIVE: To study the death burden of chronic obstructive pulmonary diseases (COPD) in west rural areas of China in 2004 - 2005. METHODS: The data from 2004 - 2005 the Third National Mortality Retrospective Sampling Survey were used in the study. A total of 28 621 276 person years were investigated in west rural areas, which covered 12 provinces, and consisted of 42 surveillance districts. Based on the data of death cause and population, mortality of COPD, years of potential life lost(YPLL) rate, working YPLL (WYPLL) rate, YPLL rate due to COPD/YPLL rate due to all deaths in west rural areas were calculated and compared with other rural areas. Standardized death rate, standardized YPLL (SYPLL) rate, standardized working YPLL (SWYPLL) rate were calculated from census data in 2000 as standard population and 2004 - 2005 national life expectancy as standard life expectancy. RESULTS: The elder has the higher crude death rate and YPLL rate of COPD in survey districts of west rural areas. And the crude death rate of COPD and YPLL rate were different in different genders. The YPLL rate was 15.47‰ in male and 15.73‰ in female. The crude death rate, YPLL rate, WYPLL rate, the ratio of YPLL rate due to COPD/YPLL rate due to all deaths in survey districts of west rural areas were: 109.53/100 000, 15.76‰, 2.82‰, 11.23%, which were high. While crude death rate, YPLL rate, WYPLL rate, the ratio of YPLL rate due to COPD/YPLL rate due to all deaths in the poorest survey districts of west rural areas were: 122.04/100 000, 27.47‰, 4.26‰, 13.44%, which were higher than other stratifications of west rural areas. CONCLUSION: The death burden of COPD in west rural areas in 2004 - 2005 was the heaviest one in China which experienced the feature that the poorer the rural regions, the heavier the death burden.


Assuntos
Efeitos Psicossociais da Doença , Doença Pulmonar Obstrutiva Crônica/economia , População Rural , China/epidemiologia , Feminino , Humanos , Masculino , Doença Pulmonar Obstrutiva Crônica/epidemiologia , Doença Pulmonar Obstrutiva Crônica/mortalidade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...