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1.
Glob Chang Biol ; 30(7): e17404, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38967125

RESUMO

The fraction of net primary productivity (NPP) allocated to belowground organs (fBNPP) in grasslands is a critical parameter in global carbon cycle models; moreover, understanding the effect of precipitation changes on this parameter is vital to accurately estimating carbon sequestration in grassland ecosystems. However, how fBNPP responds to temporal precipitation changes along a gradient from extreme drought to extreme wetness, remains unclear, mainly due to the lack of long-term data of belowground net primary productivity (BNPP) and the fact that most precipitation experiments did not have a gradient from extreme drought to extreme wetness. Here, by conducting both a precipitation gradient experiment (100-500 mm) and a long-term observational study (34 years) in the Inner Mongolia grassland, we showed that fBNPP decreased linearly along the precipitation gradient from extreme drought to extreme wetness due to stronger responses in aboveground NPP to drought and wet conditions than those of BNPP. Our further meta-analysis in grasslands worldwide also indicated that fBNPP increased when precipitation decreased, and the vice versa. Such a consistent pattern of fBNPP response suggests that plants increase the belowground allocation with decreasing precipitation, while increase the aboveground allocation with increasing precipitation. Thus, the linearly decreasing response pattern in fBNPP should be incorporated into models that forecast carbon sequestration in grassland ecosystems; failure to do so will lead to underestimation of the carbon stock in drought years and overestimation of the carbon stock in wet years in grasslands.


Assuntos
Carbono , Secas , Pradaria , Chuva , Carbono/análise , Carbono/metabolismo , China , Ciclo do Carbono , Sequestro de Carbono
2.
J Org Chem ; 89(10): 7225-7232, 2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38712792

RESUMO

Bispidine, a bridged bicyclic diamine, has been widely utilized as a rigid scaffold in chiral chelating ligands in asymmetric synthesis. In particular, a chiral bispidine-quinolizidine hybrid, such as sparteine, was utilized in asymmetric synthesis involving a metal, exhibiting superior catalytic activity. In this study, we report the design and synthesis of a series of sparteine-derived organocatalysts and the utilization of these catalysts in tandem Michael addition-cyclization reactions. These catalysts have shown excellent catalytic reactivity and enantioselectivity, and the corresponding dihydropyrano[c]chromenes have been prepared in ≤99% yield and ≤99% ee with a low catalyst loading. The recycled catalysts maintain a good catalytic performance even after four cycles, and a gram-scale reaction with a 1% catalyst loading is also performed, providing the product in 96% yield and 98% ee.

3.
J Chem Inf Model ; 64(3): 761-774, 2024 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-38215394

RESUMO

Metal complexes exhibit a diverse range of coordination geometries, representing novel privileged scaffolds with convenient click types of preparation inaccessible for typical carbon-centered organic compounds. Herein, we explored the opportunity to identify biologically active organometallic complexes by reverse docking of a rigid, minimum-size octahedral organoruthenium scaffold against thousands of protein-binding pockets. Interestingly, cannabinoid receptor type 1 (CB1) was identified based on the docking scores and the degree of overlap between the docked organoruthenium scaffold and the hydrophobic scaffold of the cocrystallized ligand. Further structure-based optimization led to the discovery of organoruthenium complexes with nanomolar binding affinities and high selectivity toward CB2. Our work indicates that octahedral organoruthenium scaffolds may be advantageous for targeting the large and hydrophobic binding pockets and that the reverse docking approach may facilitate the discovery of novel privileged scaffolds, such as organometallic complexes, for exploring chemical space in lead discovery.


Assuntos
Desenho de Fármacos , Receptor CB2 de Canabinoide , Receptores de Canabinoides/química , Receptores de Canabinoides/metabolismo , Ligação Proteica , Ligantes , Receptor CB2 de Canabinoide/metabolismo , Receptor CB1 de Canabinoide/metabolismo
4.
Glob Chang Biol ; 29(6): 1591-1605, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36515451

RESUMO

Determining the abundance of N isotope (δ15 N) in natural environments is a simple but powerful method for providing integrated information on the N cycling dynamics and status in an ecosystem under exogenous N inputs. However, whether the input of different N compounds could differently impact plant growth and their 15 N signatures remains unclear. Here, the response of 15 N signatures and growth of three dominant plants (Leymus chinensis, Carex duriuscula, and Thermopsis lanceolata) to the addition of three N compounds (NH4 HCO3 , urea, and NH4 NO3 ) at multiple N addition rates were assessed in a meadow steppe in Inner Mongolia. The three plants showed different initial foliar δ15 N values because of differences in their N acquisition strategies. Particularly, T. lanceolata (N2 -fixing species) showed significantly lower 15 N signatures than L. chinensis (associated with arbuscular mycorrhizal fungi [AMF]) and C. duriuscula (associated with AMF). Moreover, the foliar δ15 N of all three species increased with increasing N addition rates, with a sharp increase above an N addition rate of ~10 g N m-2  year-1 . Foliar δ15 N values were significantly higher when NH4 HCO3 and urea were added than when NH4 NO3 was added, suggesting that adding weakly acidifying N compounds could result in a more open N cycle. Overall, our results imply that assessing the N transformation processes in the context of increasing global N deposition necessitates the consideration of N deposition rates, forms of the deposited N compounds, and N utilization strategies of the co-existing plant species in the ecosystem.


Assuntos
Micorrizas , Nitrogênio , Compostos de Nitrogênio , Ecossistema , Plantas/microbiologia , Micorrizas/fisiologia , Solo
5.
J Environ Manage ; 347: 119121, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-37778064

RESUMO

Effective management of macronutrients is pivotal in the optimization and provisioning of ecosystem services in grassland areas, particularly in degraded grasslands. In such instances where mowing and nitrogen (N) fertilization have emerged as predominant management strategies, nutrient management is especially important. However, the precise effects of these concurrent practices on the distribution of macronutrients in plant-soil systems remain unclear. Here we evaluated the effects of 12 years of N addition (2, 10, and 50 g N m-2 year-1) and mowing on the concentrations and pools of six macronutrients (i.e., N; phosphorus P; sulfur S, calcium Ca, magnesium Mg, and potassium K) in three plant components (aboveground plants, litter, and belowground roots) at the community level and in the soil in a typical steppe in Inner Mongolia. Our results revealed that N addition generally raised the N concentration in the entire plant-soil system, regardless of whether plots were mowed. Higher N addition (10 and 50 g N m-2 year-1) also led to higher concentrations of P (+22%, averaging two N addition rates), S (+16%), K (+22%), Ca (+22%), and Mg (+24%) in plants but lower concentrations of these nutrients in the litter. Similar decreases in K (-9%), Ca (-46%), and Mg (-8%) were observed in the roots. In light of the observed increases in vegetation biomass and the lack of pronounced changes in soil bulk density, we found that the ecosystem N enrichment resulted in increased pools of all measured macronutrients in plants, litter, and roots (with the exception of Ca in the roots) while concurrently decreased the pools of P (-20%, averaging two higher N addition rates), S (-12%), K (-10%), Ca (-37%), and Mg (-19%) in the soil, with no obvious effect of the mowing practice. Overall, mowing exhibited a very limited capacity to alleviate the effects of long-term N addition on macronutrients in the plant-soil system. These findings highlight the importance of considering the distribution of macronutrients across distinct plant organs and the dynamic nutrient interplay between plants and soil, particularly in the context of long-term fertilization and mowing practices, when formulating effective grassland management strategies.


Assuntos
Ecossistema , Solo , Nitrogênio , Plantas , China , Nutrientes , Pradaria
6.
J Environ Manage ; 345: 118807, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37591093

RESUMO

Phosphorus (P) is a limiting nutrient second only to nitrogen (N) in the drylands of the world. Most previous studies have focused on N transformation processes in grassland ecosystems, particularly under artificial fertilization with N and atmospheric N deposition. However, P cycling processes under natural conditions and when P is applied as an inorganic P fertilizer have been understudied. Therefore, it is essential to examine the fate of applied P in grassland ecosystems that have experienced long-term grazing and, under certain circumstances, continuous hay harvest. We conducted a 3-year field experiment with the addition of multiple nutrient elements in a typical meadow steppe to investigate the fate of the applied P in various fractions of P pools in the top soil. We found that the addition of multiple nutrients significantly increased P concentrations in the labile inorganic P (Lab-Pi) and moderately occluded inorganic P (Mod-Pi) fractions but not in the recalcitrant inorganic P (Rec-Pi) fraction. An increase in the concentration of total inorganic P was found only when P and N were applied together. However, the addition of other nutrients did not change P concentrations in any fraction of the mineral soil. The addition of P and N significantly increased the total amount of P taken up by the aboveground plants but had no effect on the levels of organic and microbial P in the soil. Together, our results indicate that the P applied in this grassland ecosystem is taken up by plants, leaving most of the unutilized P as Lab-Pi and Mod-Pi rather than being immobilized in Rec-Pi or by microbial biomass. This implies that the grassland ecosystem that we studied has a relatively low P adsorption capacity, and the application of inorganic P to replenish soil P deficiency in degraded grasslands due to long-term grazing of livestock or continuous harvest of forage in the region could be a practical management strategy to maintain soil P fertility.


Assuntos
Ecossistema , Pradaria , Fósforo , Carbono/análise , Biomassa , Solo , Plantas , Nitrogênio/análise , Nutrientes , Fertilizantes , China
7.
J Org Chem ; 87(15): 9565-9575, 2022 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-35834751

RESUMO

A naturally occurring alkaloid aloperine was utilized as a chiral skeleton for the development of new ligands/catalysts in asymmetric synthesis. A number of N-substituted aloperines have been prepared, and a Pd-catalyzed asymmetric hydroarylation of ketimines using these chiral 1,3-diamine ligands was reported. A range of chiral sulfonyl amides were prepared in high yields and enantioselectivities. The stereoselectivity and structure relationships of aloperines have been studied. In addition, preliminary studies on the desymmetrization of meso-anhydride have also shown that these diamines have good potential in organocatalysis. These discoveries would provide a new future development for natural product-inspired chiral ligand design and developments.


Assuntos
Produtos Biológicos , Paládio , Diaminas/química , Iminas , Ligantes , Nitrilas , Quinolizidinas , Estereoisomerismo
8.
Org Biomol Chem ; 20(7): 1339-1359, 2022 02 16.
Artigo em Inglês | MEDLINE | ID: mdl-35044404

RESUMO

N-Heterocycles can be found in natural products and drug molecules and are indispensable components in the area of organic synthesis, medicinal chemistry and materials science. The construction of these N-containing heterocycles by traditional methods usually requires the preparation of reactive intermediates. In the past decades, with the rapid growth of transition metal catalysed coupling reactions, syntheses of heterocycles from precursors with inert chemical bonds have become a challenge. More recently, in the field of transition metal associated C-H direct functionalization, efficient methods have been developed for the syntheses of N-heterocyclic compounds such as aziridines, azetidines, indoles and quinolines under the click type of reaction mode. In this review, representative synthetic methodologies developed in the recent 10 years for the preparation of this small class of N-heterocycles via the Pd-catalysed C-H activation and C-N bond formation pathway are discussed. We hope this article will provide new insights from the strategies highlighted into future molecular design, synthesis and applications in medical and materials sciences.

9.
Glob Chang Biol ; 27(22): 5976-5988, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34343388

RESUMO

Higher ecosystem nitrogen (N) inputs resulting from human activities often suppress soil microbial biomass and respiration, thereby altering biogeochemical cycling. Soil acidification and carbon (C) limitation may drive these microbial responses, yet their relative importance remains elusive, which limits our understanding of the longer term effects of increasing N inputs. In a field experiment with continuous N addition at seven different rates from 0 to 50 g N m-2  year-1 over 6 years in a temperate grassland of Inner Mongolia, China, we examined the responses of soil microbial biomass and respiration to changes in soil acidity and C availability by adding lime and/or glucose to soil samples. Soil microbial biomass and respiration did only weakly respond to increasing soil pH, but increased strongly in response to higher C availability with increasing N addition rates. Soil net N immobilization increased in response to glucose addition, and soil microbial biomass increased at higher rates than microbial respiration along the gradient of previous N addition rates, both suggesting increasingly reinforced microbial C limitation with increasing N addition. Our results provide clear evidence for strong N-induced microbial C limitation, but only little support for soil acidity effects within the initial pH range of 4.73-7.86 covered by our study. Field data support this conclusion by showing reduced plant C allocation belowground in response to N addition, resulting in soil microbial C starvation over the long term. In conclusion, soil microbial biomass and respiration under N addition were strongly dependent on C availability, most likely originating from plant belowground C inputs, and was much less affected by changes in soil pH. Our data help clarify a long-standing debate about how increasing N input rates affect soil microbial biomass and respiration, and improve the mechanistic understanding of the linkages between ecosystem N enrichment and C cycling.


Assuntos
Nitrogênio , Solo , Biomassa , Carbono , Ecossistema , Pradaria , Humanos , Concentração de Íons de Hidrogênio , Nitrogênio/análise , Microbiologia do Solo
10.
Org Biomol Chem ; 19(17): 3850-3858, 2021 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-33949601

RESUMO

Density functional theory calculations have revealed the mechanism and origins of the reactivity and regioselectivity of the Cp*Ir(iii)/Cp*Rh(iii)-catalyzed allylic C-H amidation of alkenes and dioxazolones. Generally, the catalytic cycle consists of alkene coordination, C(sp3)-H activation, dioxazolone oxidative addition, reductive elimination and proto-demetallation to give the final amidation product. The C-H activation is found to be the rate-determining step, and it controls the reactivity of the reaction. For the Cp*Ir(iii)-catalyzed system, the C-H activation undergoes an Ir(iii)-assisted proton transfer process with a low energy barrier, elucidating its high reactivity. In contrast, the C-H activation step is more like a direct deprotonation in the Cp*Rh(iii)-catalyzed system, which is responsible for its higher barrier and lower reactivity. The branched-selectivity arises from the electronic effect of the alkyl group on the charge distribution over the allylic moiety. Herein, iridium(v) polarizes the allylic group greater than that of the rhodium(v) system, which accounts for its good regioselectivity. The mechanistic insights will be useful for the further development of transition metal-catalyzed selective C-H amination reactions.

11.
J Opt Soc Am A Opt Image Sci Vis ; 38(5): 750-764, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33983281

RESUMO

The imaging performance of tomographic deconvolution phase microscopy can be described in terms of the phase optical transfer function (POTF) which, in turn, depends on the illumination profile. To facilitate the optimization of the illumination profile, an analytical calculation method based on polynomial fitting is developed to describe the POTF for general nonuniform axially symmetric illumination. This is then applied to Gaussian and related profiles. Compared to numerical integration methods that integrate over a series of annuli, the present analytical method is much faster and is equally accurate. Further, a "balanced distribution" criterion for the POTF and a least-squares minimization are presented to optimize the uniformity of the POTF. An optimum general profile is found analytically by relaxed optimal search, and an optimum Gaussian profile is found through a tree search. Numerical simulations confirm the performance of these optimum profiles and support the balanced distribution criterion introduced.

12.
Proc Natl Acad Sci U S A ; 115(16): 4027-4032, 2018 04 17.
Artigo em Inglês | MEDLINE | ID: mdl-29666315

RESUMO

Despite evidence from experimental grasslands that plant diversity increases biomass production and soil organic carbon (SOC) storage, it remains unclear whether this is true in natural ecosystems, especially under climatic variations and human disturbances. Based on field observations from 6,098 forest, shrubland, and grassland sites across China and predictions from an integrative model combining multiple theories, we systematically examined the direct effects of climate, soils, and human impacts on SOC storage versus the indirect effects mediated by species richness (SR), aboveground net primary productivity (ANPP), and belowground biomass (BB). We found that favorable climates (high temperature and precipitation) had a consistent negative effect on SOC storage in forests and shrublands, but not in grasslands. Climate favorability, particularly high precipitation, was associated with both higher SR and higher BB, which had consistent positive effects on SOC storage, thus offsetting the direct negative effect of favorable climate on SOC. The indirect effects of climate on SOC storage depended on the relationships of SR with ANPP and BB, which were consistently positive in all biome types. In addition, human disturbance and soil pH had both direct and indirect effects on SOC storage, with the indirect effects mediated by changes in SR, ANPP, and BB. High soil pH had a consistently negative effect on SOC storage. Our findings have important implications for improving global carbon cycling models and ecosystem management: Maintaining high levels of diversity can enhance soil carbon sequestration and help sustain the benefits of plant diversity and productivity.


Assuntos
Biodiversidade , Sequestro de Carbono , Carbono/análise , Ecossistema , Plantas/metabolismo , Solo/química , Biomassa , China , Conservação dos Recursos Naturais , Conjuntos de Dados como Assunto , Fazendas , Florestas , Pradaria , Atividades Humanas , Humanos , Concentração de Íons de Hidrogênio , Nitrogênio/análise , Dispersão Vegetal , Plantas/química , Plantas/classificação , Chuva , Temperatura
13.
Chemistry ; 26(8): 1864-1870, 2020 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-31774593

RESUMO

Facile fabrication of nanocatalysts consisting of metal nanoparticles (NPs) anchored on a functional support is highly desirable, yet remains challenging. Covalent organic frameworks (COFs) provide an emerging materials platform for structural control and functional design. Here, a facile one-pot in situ reduction approach is demonstrated for the encapsulation of small Pd NPs into the shell of COF-derived hollow polyamine spheres (Pd@H-PPA). In the one-pot synthetic process, the nucleation and growth of Pd NPs in the cavities of the porous shell take place simultaneously with the reduction of imine linkages to secondary amine groups. Pd@H-PPA shows a significantly enhanced catalytic activity and recyclability in the tandem dehydrogenation of ammonia borane and selective hydrogenation of nitroarenes through an adsorption-activation-reaction mechanism. The strong interactions of the secondary amine linkage with borane and nitroarene molecules afford a positive synergy to promote the catalytic reaction. Moreover, the hierarchical structure of Pd@H-PPA allows the accessibility of active Pd NPs to reactants.

14.
J Opt Soc Am A Opt Image Sci Vis ; 37(12): 1857-1872, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-33362127

RESUMO

Three-dimensional quantitative phase imaging (3D QPI) is widely recognized as a potentially high-impact microscopic modality. Central to determining the resolution capability of 3D QPI is the phase optical transfer function (POTF). The magnitude of the POTF over its spatial frequency coverage (SFC) specifies the intensity of the response for each allowed spatial frequency. In this paper, a detailed analysis of the POTF for an axially symmetric optical configuration is presented. First, a useful geometric interpretation of the SFC, which enables its visualization, is presented. Second, a closed-form 1D integral expression is derived for the POTF in the general nonparaxial case, which enables rapid calculation of the POTF. Third, this formulation is applied to disk, annular, multi-annuli, and Gaussian illuminations as well as to an annular objective. Taken together, these contributions enable the visualization and simplified calculation of the 3D axially symmetric POTF and provide a basis for optimizing QPI in a wide range of applications.

15.
Gynecol Obstet Invest ; 85(2): 153-158, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31825934

RESUMO

BACKGROUND: Some previous studies already explored associations between tumor necrosis factor-α (TNF-α) polymorphisms and cervical cancer, with conflicting findings. OBJECTIVES: Here, we aimed to better analyze the relationship between TNF-α polymorphisms and cervical cancer in a larger combined population by performing a meta-analysis. METHODS: We searched PubMed, Embase, Web of Science, and CNKI for related articles. We calculated OR and 95% CI to estimate whether there are genetic associations between TNF-α polymorphisms and cervical cancer. RESULTS: Twenty-seven studies were included for this meta-analysis. TNF-α -308 G/A (dominant comparison: p = 0.0004, OR 0.71, 95% CI 0.58-0.86; recessive comparison: p = 0.0002, OR 1.46, 95% CI 1.19-1.79; overdominant comparison: p = 0.002, OR 1.37, 95% CI 1.12-1.68; allele comparison: p < 0.0001, OR 0.72, 95% CI 0.62-0.83) polymorphism was found to be significantly associated with cervical cancer in general population. Subgroup analyses showed similar positive findings for -308 G/A polymorphism in both Asians and Caucasians. Moreover, we found that -238 G/A polymorphism was also significantly associated with cervical cancer in Asians. CONCLUSIONS: This meta-analysis proved that TNF-α -238 and -308 G/A polymorphisms could be used to identity individual with elevated susceptibility to cervical cancer in certain populations.


Assuntos
Predisposição Genética para Doença/genética , Polimorfismo de Nucleotídeo Único , Fator de Necrose Tumoral alfa/genética , Neoplasias do Colo do Útero/genética , Alelos , Povo Asiático/genética , Feminino , Predisposição Genética para Doença/etnologia , Humanos , Neoplasias do Colo do Útero/etnologia , População Branca/genética
16.
Phys Chem Chem Phys ; 21(29): 16316-16322, 2019 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-31305814

RESUMO

Overcoming the restriction of the energy gap (700-800 cm-1) in Er3+-doped upconversion (UC) materials to achieve high detection accuracy is crucial for practical temperature detection applications. Herein, we design a feasible route based on the different thermal response behaviors of various hosts to enhance the SA value in a double perovskite NaLaMgWO6:Er,Mo system. The maximum SA value is 222.8 × 10-4@423 K in the NLMW:5%Er3+ host, and this can be promoted to 275.4 × 10-4 K-1@323 K in the NaLaMgWO6:Er,Mo system. The SR values decrease monotonously as the temperature rises, and this is due to the dependency of the SR values on the energy gap. A mechanism that is ascribed to the different thermal response behaviors of the various hosts is proposed, and this mechanism is further proved by investigating the temperature sensing properties of barium gadolinium zincate phosphors that possess the same thermal response behaviors. In addition, this study introduces the idea that a host with a high emission intensity for the 2H11/2 level and a lower emission intensity for the 4S3/2 level is highly suitable for temperature measurements. A thorough investigation of this system offers a strategy to acquire a high SA value and reveals the broad prospects of NaLaMgWO6:Er,Mo in the temperature detection field.

17.
Med Sci Monit ; 25: 8905-8912, 2019 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-31760402

RESUMO

BACKGROUND Tamoxifen (TAM) is the first-line drug for estrogen receptor-positive (ER+) breast cancer (BC) treatment. However, its resistance is a main obstacle in clinical practice. Thus, new therapeutic agents are urgently needed to fight TAM resistance. MATERIAL AND METHODS Here, we constructed TAM-resistant ER+BC cells with TAM resistance, named MCF-7-R. Western blot, quantitative real-time PCR (qRT-PCR), ALDH1 activity analysis, and spheroid-forming detection were used to detect the stemness of cells and the effects of napabucasin (NP) on BC cell stemness. Cell counting kit-8 (CCK8) assay was used to evaluate the effects of NP on cell viability. RESULTS MCF-7-R cells exhibited higher stemness compared with the parental MCF-7 cells, which was evident by the increased spheroid formation ability at diluted concentration, aldehyde dehydrogenase (ALDH) activity, and expression of stemness critical biomarkers (Oct4, Nanog, and Sox2). Additionally, it was found that napabucasin (NP) specifically killed MCF-7-T cells, characterized by remarkably decreased IC50 value. Notably, NP reduced MCF-7-R cell stemness, which was evident as the decreased stemness marker expression, spheroid-forming capacity, and ALDH1 activity. Importantly, NP attenuated TAM resistance of MCF-7-R cells and enhanced sensitivity of MCF-7 cells to TAM. Mechanistic study showed that NP inhibited STAT3 activation, and overexpression of STAT3 rescued NP-mediated inhibition of the stemness-like characteristics of MCF-7-R cells. CONCLUSIONS NP might be used as an adjuvant therapy for ER+ BC patients with TAM resistance.


Assuntos
Benzofuranos/farmacologia , Neoplasias da Mama/metabolismo , Naftoquinonas/farmacologia , Células-Tronco Neoplásicas/efeitos dos fármacos , Antineoplásicos Hormonais/farmacologia , Apoptose/efeitos dos fármacos , Benzofuranos/metabolismo , Neoplasias da Mama/tratamento farmacológico , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , China , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/fisiologia , Receptor alfa de Estrogênio/metabolismo , Humanos , Células MCF-7 , Naftoquinonas/metabolismo , Receptores de Estrogênio/metabolismo , Transdução de Sinais/efeitos dos fármacos , Células-Tronco/metabolismo , Tamoxifeno/farmacologia
18.
Int J Mol Sci ; 20(1)2019 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-30626061

RESUMO

As a promising energy plant for biodiesel, Jatropha curcas is a tropical and subtropical shrub and its growth is affected by one of major abiotic stress, chilling. Therefore, we adopt the phosphoproteomic analysis, physiological measurement and ultrastructure observation to illustrate the responsive mechanism of J. curcas seedling under chilling (4 °C) stress. After chilling for 6 h, 308 significantly changed phosphoproteins were detected. Prolonged the chilling treatment for 24 h, obvious physiological injury can be observed and a total of 332 phosphoproteins were examined to be significantly changed. After recovery (28 °C) for 24 h, 291 phosphoproteins were varied at the phosphorylation level. GO analysis showed that significantly changed phosphoproteins were mainly responsible for cellular protein modification process, transport, cellular component organization and signal transduction at the chilling and recovery periods. On the basis of protein-protein interaction network analysis, phosphorylation of several protein kinases, such as SnRK2, MEKK1, EDR1, CDPK, EIN2, EIN4, PI4K and 14-3-3 were possibly responsible for cross-talk between ABA, Ca2+, ethylene and phosphoinositide mediated signaling pathways. We also highlighted the phosphorylation of HOS1, APX and PIP2 might be associated with response to chilling stress in J. curcas seedling. These results will be valuable for further study from the molecular breeding perspective.


Assuntos
Temperatura Baixa , Jatropha/metabolismo , Jatropha/fisiologia , Fosfoproteínas/metabolismo , Proteínas de Plantas/metabolismo , Proteômica/métodos , Plântula/metabolismo , Estresse Fisiológico , Motivos de Aminoácidos , Sequência de Aminoácidos , Ontologia Genética , Jatropha/ultraestrutura , Anotação de Sequência Molecular , Fosfopeptídeos/metabolismo , Fosfoproteínas/química , Fosforilação , Folhas de Planta/metabolismo , Folhas de Planta/ultraestrutura , Proteínas de Plantas/química , Mapas de Interação de Proteínas , Plântula/anatomia & histologia , Plântula/fisiologia , Plântula/ultraestrutura
19.
Cell Mol Biol (Noisy-le-grand) ; 64(13): 33-37, 2018 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-30403607

RESUMO

Many studies conducted on the relationship between serum iron levels and lung cancer risk had produced inconsistent results. We therefore conducted a meta-analysis to determine whether serum iron levels were lower in lung cancer patients compared to those in controls.A literature survey was conducted by searching the PubMed, WanFang, CNKI, and SinoMed databases for articles published as of Mar 1, 2018. Standard mean differences (SMD) with the corresponding 95% confidence intervals (CI) were executed by Stata 12.0 software. A total of 13 publications involving 1118 lung cancer patients and 832 controls were included in our study. The combined results showed that serum iron levels in lung cancer cases had no significantly lower when compared to those in controls [summary SMD = -0.125, 95%CI= -0.439, 0.189, Z = 0.78, p for Z test= 0.435], with high heterogeneity (I2= 89.9%, P< 0.001) found. In the stratified analysis by geographic locations, consistent results were found for serum iron levels between lung cancer patients and controls both in Asian populations [summary SMD = -0.113, 95%CI= -0.471, 0.245] and European populations [summary SMD = -0.215, 95%CI= -0.835, 0.404]. Publication bias was not found when evaluated by Begg's funnel plot and Egger's regression asymmetry test.In summary, the current study showed that serum iron levels had no significant association on lung cancer risk.


Assuntos
Ferro/sangue , Neoplasias Pulmonares/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Humanos , Pessoa de Meia-Idade , Viés de Publicação , Fatores de Risco , Adulto Jovem
20.
Opt Express ; 25(20): 24346-24361, 2017 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-29041379

RESUMO

Surface deformations of large reflector antennas highly depend on elevation angle. This paper adopted a scheme with the ability to conduct measurement at any elevation angle: carrying an emission source, an unmanned aerial vehicle (UAV) scans the antenna on a near-field plane, meanwhile the antenna stays stationary. Near-field amplitude is measured in the scheme. To recover the deformation from the measured amplitude, this paper proposed a novel algorithm by deriving the deformation-amplitude equation, which reveals the relation between the surface deformation and the near-field amplitude. By the algorithm, a precise deformation recovery can be reached at a low frequency (<1GHz) through single near-field amplitude. Simulation results showed the high accuracy and adaptability of the algorithm.

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