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1.
Biochem Biophys Res Commun ; 664: 59-68, 2023 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-37141639

RESUMO

In recent years, bone loss related diseases have attracted more and more attention, such as osteoporosis and osteonecrosis of the femoral head exhibited symptoms of osteopenia or insufficient bone mass in a certain stage. Mesenchymal stem cells (MSCs), which can be induced to differentiate into osteoblasts under certain conditions can provide a new solution bone disease. Herein, we deciphered the possible mechanism by which BMP2 drives the transduction of MSCs to the osteoblast lineage through ACKR3/p38/MAPK signaling. The levels of ACKR3 in femoral tissues of samples from humans with different ages and sexes were measured firstly and found that ACKR3 protein levels increase with age. In vitro cellular assays showed that ACKR3 inhibits BMP2-induced osteo-differentiation and promotes adipo-differentiation of MSCs, whereas siACKR3 exhibited the opposite effects. In vitro embryo femur culture experiment showed that inhibition of ACKR3 enhanced BMP2-induced trabecular bone formation in C57BL6/J mouse. In terms of molecular mechanisms, we found that p38/MAPK signaling might play the key role. ACKR3 agonist TC14012 suppressed the phosphorylation of p38 and STAT3 in BMP2 induced MSCs differentiation. Our findings suggested that ACKR3 might be a novel therapeutic target for the treatment of bone-associated diseases and bone-tissue engineering.


Assuntos
Células-Tronco Mesenquimais , Osteogênese , Animais , Camundongos , Humanos , Diferenciação Celular , Osso e Ossos/metabolismo , Osteoblastos/metabolismo , Proteína Morfogenética Óssea 2/metabolismo , Células Cultivadas
2.
Small ; 19(29): e2301915, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37189236

RESUMO

Pressure-stabilized high-entropy sulfide (FeCoNiCuRu)S2 (HES) is proposed as an anode material for fast and long-term stable lithium/sodium storage performance (over 85% retention after 15 000 cycles @10 A g-1 ). Its superior electrochemical performance is strongly related to the increased electrical conductivity and slow diffusion characteristics of entropy-stabilized HES. The reversible conversion reaction mechanism, investigated by ex-situ XRD, XPS, TEM, and NMR, further confirms the stability of the host matrix of HES after the completion of the whole conversion process. A practical demonstration of assembled lithium/sodium capacitors also confirms the high energy/power density and long-term stability (retention of 92% over 15 000 cycles @5 A g-1 ) of this material. The findings point to a feasible high-pressure route to realize new high-entropy materials for optimized energy storage performance.

3.
BMC Plant Biol ; 22(1): 512, 2022 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-36324083

RESUMO

BACKGROUND: Calcineurin B-like proteins (CBLs) are ubiquitous Ca2+ sensors that mediate plant responses to various stress and developmental processes by interacting with CBL-interacting protein kinases (CIPKs). CBLs and CIPKs play essential roles in acclimatization of crop plants. However, evolution of these two gene families in the genus Medicago is poorly understood. RESULTS: A total of 68 CBL and 135 CIPK genes have been identified in five genomes from Medicago. Among these genomes, the gene number of CBLs and CIPKs shows no significant difference at the haploid genome level. Phylogenetic and comprehensive characteristic analyses reveal that CBLs and CIPKs are classified into four clades respectively, which is validated by distribution of conserved motifs. The synteny analysis indicates that the whole genome duplication events (WGDs) have contributed to the expansion of both families. Expression analysis demonstrates that two MsCBLs and three MsCIPKs are specifically expressed in roots, mature leaves, developing flowers and nitrogen fixing nodules of Medicago sativa spp. sativa, the widely grown tetraploid species. In particular, the expression of these five genes was highly up-regulated in roots when exposed to salt and drought stress, indicating crucial roles in stress responses. CONCLUSIONS: Our study leads to a comprehensive understanding of evolution of CBL and CIPK gene families in Medicago, but also provides a rich resource to further address the functions of CBL-CIPK complexes in cultivated species and their closely related wild relatives.


Assuntos
Secas , Proteínas de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Medicago/metabolismo , Filogenia , Proteínas Serina-Treonina Quinases/genética , Cloreto de Sódio/metabolismo , Estresse Fisiológico/genética , Regulação da Expressão Gênica de Plantas , Proteínas de Ligação ao Cálcio/genética
4.
Toxicol Appl Pharmacol ; 440: 115940, 2022 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-35219640

RESUMO

Cyclin-dependent kinase 5 regulatory subunit-associated protein 3 (CDK5RAP3) has been documented as a vital cancer-related protein that is implicated in numerous cancer types. However, the relevance of CDK5RAP3 in papillary thyroid carcinoma (PTC) is less well understood. The goal of this work was to understand the relationship between CDK5RAP3 and PTC. Our data showed significant decreases in CDK5RAP3 levels in PTC tissues and cell lines. Functional studies revealed that upregulation of CDK5RAP3 in PTC cell lines resulted in significant reduction of cellular proliferation. Moreover, overexpression of CDK5RAP3 induced apoptosis and cell cycle arrest in PTC cells. In addition, the migration, invasion and epithelial-mesenchymal transition in PTC cells were markedly suppressed via overexpression of CDK5RAP3. Further investigation documented that overexpression of CDK5RAP3 remarkably downregulated the levels of phospho-Akt, phospho-GSK-3ß, and active ß-catenin, leading to a significant decrease in activation of the Wnt/ß-catenin pathway. Notably, knockdown of Akt abolished CDK5RAP3-silencing-mediated effects on the Wnt/ß-catenin pathway. Reactivation of the Wnt/ß-catenin pathway partially reversed CDK5RAP3-mediated tumor-inhibitory effects in PTC cells. Overexpression of CDK5RAP3 also weakened the tumorigenic potential of PTC cells in vivo. In summary, our work demonstrates that CDK5RAP3 is underexpressed in PTC and acts as a putative tumor suppressor of PTC. Our findings reveal that CDK5RAP3 exerts a tumor-suppressive role in PTC through downregulation of Wnt/ß-catenin signaling via modulation of the Akt/GSK-3ß axis.


Assuntos
Proteínas de Ciclo Celular , Câncer Papilífero da Tireoide , Neoplasias da Glândula Tireoide , Proteínas Supressoras de Tumor , Via de Sinalização Wnt , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/fisiologia , Quinase 5 Dependente de Ciclina/metabolismo , Glicogênio Sintase Quinase 3 beta/metabolismo , Humanos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Câncer Papilífero da Tireoide/patologia , Neoplasias da Glândula Tireoide/patologia , Proteínas Supressoras de Tumor/metabolismo , beta Catenina/metabolismo
5.
Phys Chem Chem Phys ; 24(21): 13033-13039, 2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-35583230

RESUMO

KSiH3 exhibits 4.1 wt% experimental hydrogen storage capacity and shows reversibility under moderate conditions, which provides fresh impetus to the search for other complex hydrides in the K-Si-H system. Here, we reproduce the stable Fm3̄m phase of K2SiH6 and uncover two denser phases, space groups P3̄m1 and P63mc at ambient pressure, by means of first-principles structure searches. We note that P3̄m1-K2SiH6 has a high hydrogen content of 5.4 wt% and a volumetric density of 88.3 g L-1. Further calculations suggest a favorable dehydrogenation temperature Tdes of -20.1/55.8 °C with decomposition into KSi + K + H2. The higher hydrogen density and appropriate dehydrogenation temperature indicate that K2SiH6 is a promising hydrogen storage material, and our results provide helpful and clear guidance for further experimental studies. We found three further potential hydrogen storage materials stable at high pressure: K2SiH8, KSiH7 and KSiH8. These results suggest the need for further investigations into hydrogen storage materials among such ternary hydrides at high pressure.

6.
Mol Breed ; 41(12): 73, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37309520

RESUMO

Photo-(thermo-) sensitive genic male-sterile line is the key component of two-line hybridization system in foxtail millet (Setaria italica), but the genetic basis of male sterility in most male-sterile lines is still unclear. In the present study, a large F2 population was developed derived from a cross between the photo-(thermo-) sensitive male-sterile line A2 and the fertile-line 1484-5. Thirty plants with extreme high and extreme low fertility were selected from the population to construct a sterile DNA pool and a fertile DNA pool, respectively. Sequencing both DNA pools and data analysis revealed that two QTLs conferred male-sterility, qSiMS6.1 with a major effect and qSiMS6.2 with a minor effect, on chromosome 6. Both QTLs exhibited complete dominance. The major QTL, qSiMS6.1, was delimited to a 186-kb interval between the markers SiM20 and SiM9 by the joint analysis of QTL-seq and QTL mapping with SSR and structure variation markers. Millet_GLEAN_10020454 in this region is the most likely candidate gene for qSiMS6.1 since it is predicted to encode a male-sterile 5 like protein. These results lay a solid foundation for qSiMS6.1 cloning and provided gene resources for breeding new male-sterile lines. Supplementary Information: The online version contains supplementary material available at 10.1007/s11032-021-01269-2.

7.
J Musculoskelet Neuronal Interact ; 21(2): 272-278, 2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-34059572

RESUMO

OBJECTIVES: To evaluate the effect of high-quality care on limb function recovery and quality of life (QOL) after osteoporotic hip fracture (OHF) surgery in the elderly. METHODS: 116 elderly patients with OHF enrolled in our hospital from January 2017 to December 2019 were assigned into observation group (high-quality care, n=58) and control group (routine care, n=58). After one month of intervention, Harris Hip Score (HHS) and Barthel Index (BI) were used to evaluating limb function and self-care ability, pain intensity numerical rating scale (PINRS) for pain assessment, self-rating anxiety scale (SAS), and self-rating depression scale (SDS) for emotion assessment. Besides, postsurgical complications, QOL and patient satisfaction were examined. RESULTS: HHS and BI were higher in observation group (P<0.05); PINRS, SAS and SDS were lower in observation group (P<0.05); incidence of postsurgical complications in the observation group was significantly lower than that in the control group (P<0.05); QOL and patient satisfaction in the observation group were higher than those in the control group (P<0.05). CONCLUSION: High-quality care promotes the recovery of limb function, the QOL and the satisfaction of elderly patients.


Assuntos
Fraturas por Osteoporose , Qualidade de Vida , Idoso , Humanos , Fraturas por Osteoporose/cirurgia , Recuperação de Função Fisiológica
8.
Gondwana Res ; 93: 243-251, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33584115

RESUMO

COVID-19 (Corona Virus Disease 2019) is a severe respiratory syndrome currently causing a human global pandemic. The original virus, along with newer variants, is highly transmissible. Aerosols are a multiphase system consisting of the atmosphere with suspended solid and liquid particles, which can carry toxic and harmful substances; especially the liquid components. The degree to which aerosols can carry the virus and cause COVID-19 disease is of significant research importance. In this study, we have discussed aerosol transmission as the pathway of SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2), and the aerosol pollution reduction as a consequence of the COVID-19 lockdown. The aerosol transmission routes of the SARS-CoV-2 can be further subdivided into proximal human-exhaled aerosol transmission and potentially more distal ambient aerosol transmission. The human-exhaled aerosol transmission is a direct dispersion of the SARS-CoV-2. The ambient aerosol transmission is an indirect dispersion of the SARS-CoV-2 in which the aerosol acts as a carrier to spread the virus. This indirect dispersion can also stimulate the up-regulation of the expression of SARS-CoV-2 receptor ACE-2 (Angiotensin Converting Enzyme 2) and protease TMPRSS2 (Transmembrane Serine Protease 2), thereby increasing the incidence and mortality of COVID-19. From the aerosol quality data around the World, it can be seen that often atmospheric pollution has significantly decreased due to factors such as the reduction of traffic, industry, cooking and coal-burning emissions during the COVID-19 lockdown. The airborne transmission potential of SARS-CoV-2, the infectivity of the virus in ambient aerosols, and the reduction of aerosol pollution levels due to the lockdowns are crucial research subjects.

9.
Mol Phylogenet Evol ; 145: 106734, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31972240

RESUMO

Orthoptera is the most diverse order of polyneopterans, and the forewing and hindwing of its members exhibit extremely variability from full length to complete loss in many groups; thus, this order provides a good model for studying the effects of insect flight ability on the evolutionary constraints on and evolutionary rate of the mitochondrial genome. Based on a data set of mitochondrial genomes from 171 species, including 43 newly determined, we reconstructed Orthoptera phylogenetic relationships and estimated the divergence times of this group. The results supported Caelifera and Ensifera as two monophyletic groups, and revealed that Orthoptera originated in the Carboniferous (298.997 Mya). The date of divergence between the suborders Caelifera and Ensifera was 255.705 Mya, in the late Permian. The major lineages of Acrididae seemed to have radiated in the Cenozoic, and the six patterns of rearrangement of 171 Orthoptera mitogenomes mostly occurred in the Cretaceous and Cenozoic. Based on phylogenetic relationships and ancestral state reconstruction, we analysed the evolutionary selection pressure on and evolutionary rate of mitochondrial protein-coding genes (mPCGs). The results indicated that during approximately 300 Mya of evolution, these genes experienced purifying selection to maintain their function. Flightless orthopteran insects accumulated more non-synonymous mutations than flying species and experienced more relaxed evolutionary constraints. The different wing types had different evolutionary rates, and the mean evolutionary rate of Orthoptera mitochondrial mPCGs was 13.554 × 10-9 subs/s/y. The differences in selection pressures and evolutionary rates observed between the mitochondrial genomes suggested that functional constraints due to locomotion play an important role in the evolution of mitochondrial DNA in orthopteran insects with different wing types.


Assuntos
Evolução Biológica , Mitocôndrias/genética , Ortópteros/classificação , Animais , Biodiversidade , Fases de Leitura Aberta/genética , Ortópteros/anatomia & histologia , Ortópteros/genética , Filogenia , RNA Ribossômico/genética , Asas de Animais/anatomia & histologia
10.
Phys Rev Lett ; 125(21): 217001, 2020 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-33275012

RESUMO

The recent discovery of H_{3}S and LaH_{10} superconductors with record high superconducting transition temperatures T_{c} at high pressure has fueled the search for room-temperature superconductivity in the compressed superhydrides. Here we introduce a new class of high T_{c} hydrides with a novel structure and unusual properties. We predict the existence of an unprecedented hexagonal HfH_{10}, with remarkably high value of T_{c} (around 213-234 K) at 250 GPa. As concerns the novel structure, the H ions in HfH_{10} are arranged in clusters to form a planar "pentagraphenelike" sublattice. The layered arrangement of these planar units is entirely different from the covalent sixfold cubic structure in H_{3}S and clathratelike structure in LaH_{10}. The Hf atom acts as a precompressor and electron donor to the hydrogen sublattice. This pentagraphenelike H_{10} structure is also found in ZrH_{10}, ScH_{10}, and LuH_{10} at high pressure, each material showing a high T_{c} ranging from 134 to 220 K. Our study of dense superhydrides with pentagraphenelike layered structures opens the door to the exploration of a new class of high T_{c} superconductors.

11.
J Environ Sci Health B ; 55(6): 525-529, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32077369

RESUMO

Telomere length was found to be associated with omethoate exposure and polymorphisms in certain genes among occupational workers. However, whether the polymorphisms in telomere-binding protein genes influence telomere length remains unclear. To explore the correlation between telomere length and polymorphisms in telomere-binding protein genes, telomere length in peripheral blood leukocytes was determined by real-time quantitative polymerase chain reaction in 180 omethoate-exposed workers and 115 healthy controls. Polymorphisms in 10 pairs of alleles were detected using flight mass spectrometry or polymerase chain reaction-restriction fragment length polymorphism technique. The results showed that individuals with GG genotype in TRF1 rs3863242 had longer telomere lengths than those with AG + AA genotype in the control group (p = 0.005). The multiple regression analysis suggested that both omethoate exposure (b = 0.526, p < 0.001) and TRF1 rs3863242 GG (b = 0.220, p = 0.002) were related to a longer telomere length. In conclusion, GG genotype in TRF1 rs3863242 is linked to prolongation of telomere length, and individuals with GG genotype are recommended to strengthen health protection in a Chinese occupational omethoate-exposed population.


Assuntos
Dimetoato/análogos & derivados , Exposição Ocupacional , Polimorfismo de Nucleotídeo Único , Telômero/efeitos dos fármacos , Proteína 1 de Ligação a Repetições Teloméricas/genética , Adulto , Povo Asiático , Estudos de Casos e Controles , Dimetoato/toxicidade , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Exposição Ocupacional/efeitos adversos , Reação em Cadeia da Polimerase/métodos , Polimorfismo de Fragmento de Restrição , Complexo Shelterina , Proteínas de Ligação a Telômeros/genética , Proteína 2 de Ligação a Repetições Teloméricas/genética
12.
Phys Chem Chem Phys ; 21(32): 17621-17627, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31347635

RESUMO

In addition to the known Au3+ and Au5+, it has recently been shown that Au is likely to possess unusual valence states in compressed Au-F compounds. However, our simulations reveal that polymeric ground-state AuF4 shows an unexpected 6-fold coordination rather than a 4-fold one, indicating that more complete comprehending on the anomalous Au4+ is highly required. To fully understand the nature and origin of anomalous valence states in Au, we have extensively investigated the ground-state structures of Au-F compounds at high pressures using quantum mechanical computational methods. As a consequence, we identify several previously unreported (stable) AuF2, AuF3 and AuF4 structures. Our results extend the known polymorphism of AuFn compounds and offer a fundamental understanding of the origin of unusual valence states in Au that prevail at high pressure.

13.
Ecotoxicol Environ Saf ; 182: 109453, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31349105

RESUMO

Telomeres are DNA-protein structures that protect chromosome ends from degradation and fusion, which are shortened by oxidative stress, for example air pollution including benzene, toluene, Coke Oven Emissions (COEs), and so on. As a biomarker of health and disease, telomere length is associated with cardiovascular, diabetes and cancers. The aim of this study was to estimate the effects of COEs exposure on telomere length and the benchmark dose (BMD) of COEs. A total of 542 coke oven workers and 235 healthy controls without exposure to toxicants were recruited. Quantitative PCR was used to determine the telomere length in human peripheral blood leukocytes DNA. Propensity scoring was used to match coke oven workers to healthy controls. Linear regression models and trend tests were used to the relationship between COEs exposure and telomere length. Telomere length in COEs exposed group 0.764 (0.536, 1.092) was significantly shorter than that in the control group 1.064(0.762, 1.438), (P < 0.001). There were significantly dose-response relationships between COEs exposure and telomere damage with telomere length as a biomarker. A BMDL value lower than the present occupational exposure limits (OELs) of COEs exposure was evaluated using the BMD approach in coke oven workers. Our results suggested that shorter telomere length is related to occupational exposure to COEs and the level of COEs exposure lower than the current national OELs in China and many other countries could induce telomere damage.


Assuntos
Poluentes Ocupacionais do Ar/análise , Coque/análise , Exposição Ocupacional/análise , Telômero/efeitos dos fármacos , Adolescente , Adulto , Poluentes Ocupacionais do Ar/toxicidade , Benchmarking , Biomarcadores/análise , Estudos de Casos e Controles , China , Coque/toxicidade , Relação Dose-Resposta a Droga , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Exposição Ocupacional/efeitos adversos , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/genética , Telômero/ultraestrutura , Adulto Jovem
14.
Ecotoxicol Environ Saf ; 172: 82-88, 2019 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-30684755

RESUMO

Omethoate, an organophosphorous pesticide, causes a variety of health effects, especially the damage of chromosome DNA. The aim of the study was to assess the correlation between polymorphisms of encoding miRNA genes and telomere length in omethoate-exposure workers. 180 workers with more than 8 years omethoate-exposure and 115 healthy controls were recruited in the study. Genotyping for the selected single nucleotide polymorphisms loci were performed using the flight mass spectrometry. Real-time fluorescent quantitative polymerase chain reaction(PCR) method was applied to determine the relative telomere length(RTL) in human peripheral blood leukocytes DNA. After adjusting the covariate of affecting RTL, covariance analysis showed that the female was significantly longer than that of the male in control group(P < 0.046). For the miR-145 rs353291 locus, this study showed that RTL of mutation homozygous AG+GG individuals was longer than that of wild homozygous AA in the exposure group (P = 0.039). In the control group, RTL with wild homozygous TT genotype in miR-30a rs2222722 polymorphism locus was longer than that of the mutation homozygous CC genotype (P = 0.038). After multiple linear regression analysis, the independent variables of entering into the model were omethoate-exposure (b = 0.562, P < 0.001), miR-145 rs353291 (AG+GG) (b = 0.205, P = 0.010). The prolongation of relative telomere length in omethoate exposed workers was associated with AG+GG genotypes in rs353291 polymorphism of encoding miR-145 gene.


Assuntos
Dimetoato/análogos & derivados , MicroRNAs/genética , Polimorfismo de Nucleotídeo Único , Homeostase do Telômero/efeitos dos fármacos , Telômero/efeitos dos fármacos , Adulto , Estudos de Casos e Controles , DNA/genética , Dano ao DNA/efeitos dos fármacos , Dimetoato/toxicidade , Feminino , Loci Gênicos , Genótipo , Humanos , Leucócitos/efeitos dos fármacos , Leucócitos/metabolismo , Masculino , Pessoa de Meia-Idade
15.
J Environ Sci Health B ; 54(12): 948-953, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31405322

RESUMO

Omethoate is an organophosphorus pesticide that poses a major health hazard, especially DNA damage. The purpose of this study was to investigate the factors affecting telomere length in workers exposed to omethoate by analyzing the interaction between cell cycle gene polymorphism and environmental factors. The exposure group consisted of 118 workers exposed to omethoate for 8-10 years, the control group comprised 115 healthy people without occupational toxicant exposure history. The telomere length of genomic DNA from peripheral blood leucocyte was determined with real-time PCR. Polymerase chain reaction and restriction fragment length polymorphism was used to detect the polymorphisms in p53, p21 and MDM2 gene. The telomere length in the (CA + AA) genotypes for p21 rs1801270 polymorphism was longer than that in the CC genotype in control group (P = 0.015). The generalized linear model analysis indicated the interaction of the p21 rs1801270 polymorphic (CA + AA) genotypes and smoking has a significant effect on telomere length (ß = -0.258, P = 0.085). The prolongation of telomere length in omethoate-exposed workers was associated with genotypes (CA + AA) of p21 rs1801270, and interactions of (CA + AA) genotypes and smoking factor.


Assuntos
Dimetoato/análogos & derivados , Exposição Ocupacional/efeitos adversos , Praguicidas/toxicidade , Fumar/efeitos adversos , Telômero/metabolismo , Adulto , Dano ao DNA/efeitos dos fármacos , Dimetoato/toxicidade , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo Genético/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-mdm2/genética , Telômero/genética , Proteína Supressora de Tumor p53/genética
16.
J Am Chem Soc ; 140(42): 13970-13975, 2018 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-30265807

RESUMO

Pressure quenching of optical emission largely limits the potential application of many materials in optical pressure-sensing devices, since emission intensity is crucially connected to performance. Boosting visible-light emission at high pressure is, therefore, an important goal. Here, we demonstrate that the emission of CdSe nanocrystals (NCs) can be enhanced by more than an order of magnitude by compression. The brightest emission can be achieved at pressures corresponding to the phase transitions in different sized CdSe NCs. Very bright blue emission can be obtained by exploiting the increase in band gap with increasing pressure. First-principles calculations indicate that the interaction between the capping oleic acid (OA) layer and the CdSe core is strengthened with increased Hirshfeld charge at high pressure. The effective surface reconstruction associated with the removal of surface-related trap states is highly responsible for the pressure-induced emission enhancement of these CdSe NCs. These findings pave the way for designing a stress nanogauge with easy optical readout and provide a route for tuning bright-fluorescence imaging in response to an externally applied pressure.

17.
Phys Rev Lett ; 121(25): 255703, 2018 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-30608845

RESUMO

There is compelling geochemical evidence for primordial helium trapped in Earth's lower mantle, but the origin and nature of the helium source remain elusive due to scarce knowledge on viable helium-bearing compounds that are extremely rare. Here we explore materials physics underlying this prominent challenge. Our structure searches in conjunction with first-principles energetic and thermodynamic calculations uncover a remarkable helium-bearing compound FeO_{2}He at high pressure-temperature conditions relevant to the core-mantle boundary. Calculated sound velocities consistent with seismic data validate FeO_{2}He as a feasible constituent in ultralow velocity zones at the lowermost mantle. These mutually corroborating findings establish the first and hitherto only helium-bearing compound viable at pertinent geophysical conditions, thus providing vital physics mechanisms and materials insights for elucidating the enigmatic helium reservoir in deep Earth.

18.
Phys Chem Chem Phys ; 20(46): 29472-29479, 2018 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-30456400

RESUMO

Transition metal dichalcogenides have attracted significant attention due to both fundamental interest and their potential applications. Here, we have systematically explored the crystal structures of ReX2 (X = S, Se, and Te) over the pressure range of 0-300 GPa, employing swarm-intelligence-based structure prediction methodology. Several new structures are found to be stable at high pressures. The calculated enthalpy of formation suggested that all predicted high-pressure structures are stable against decomposition into elemental end-members. Moreover, we found that the simulated X-ray diffraction patterns of ReSe2 are in good agreement with experimental data. Pressure-induced metallization of ReX2 has been revealed from the analysis of its electronic structure. Our electron-phonon coupling calculations indicate ReSe2 and ReTe2 are superconducting phases at high pressures.

19.
J Clin Lab Anal ; 32(1)2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28233337

RESUMO

BACKGROUND: Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) is a common and mature method of detecting the single nucleotide polymorphism (SNP). But, for the polymorphism site rs3863242 of telomeric repeat binding factor 1(TERF1) gene, there is no appropriate restriction enzyme to recognize it, which limits the research between the variants of rs3863242 and human diseases. METHODS: The reverse primer was designed based on turning the 3rd base T into the mismatch base G. After PCR amplification, a new restriction enzyme site was introduced into the TERF1 gene amplification products. Two hundred forty samples from Chinese Han individuals were genotyped to evaluate this method. RESULTS: A new restriction enzyme site for CviQI was introduced into the PCR products. The genotype frequencies of 240 samples from Chinese Han individuals were 4.17% for A/A, 29.58% for A/G, 66.25% for G/G respectively. The allele frequencies were 18.96% for A and 81.04% for G respectively. The genotyping results of PCR products were consistent with the gene sequencing result. CONCLUSIONS: We developed a simple, direct and economical technique for analyzing the polymorphism of TERF1 rs3863242. It may be applied to the colony screening of other SNPs, mutation-screening of tumor-related gene or mutations in some specific genes on a large scale, in the future.


Assuntos
Reação em Cadeia da Polimerase/métodos , Polimorfismo de Fragmento de Restrição/genética , Polimorfismo de Nucleotídeo Único/genética , Proteínas de Ligação a Telômeros/genética , Humanos , Complexo Shelterina
20.
Ecotoxicol Environ Saf ; 161: 563-568, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29929132

RESUMO

Omethoate, an organophosphorous pesticide, can cause a variety of health effects, especially the decrease of cholinesterase activity. The aim of this study is to explore the association of genetic polymorphisms of telomere binding proteins with cholinesterase activity in omethoate-exposed population. Cholinesterase activities in whole blood, red blood cell and plasma were detected using acetylthiocholine and dithio-bis-(nitrobenzoic acid) method; Genetic Genotyping of POT1 rs1034794, POT1 rs10250202, TERF1 rs3863242 and TERT rs2736098 were performed with PCR-RFLP. The cholinesterase activities of whole blood, red blood cells and plasma in exposure group are significantly lower than that of the control group (P < 0.001). Multivariate analysis indicates that exposure group (b = - 1.016, P < 0.001), agender (b = 0.365, P < 0.001), drinking (b = 0.271, P = 0.004) and TERF1rs3863242 (b = - 0.368, P = 0.016) had an impact on cholinesterase activities. The results suggest that individual carrying AG+GG genotypes in TERF1 gene rs3863242 polymorphism were susceptible to damage in cholinesterase induced by omethoate.


Assuntos
Poluentes Ocupacionais do Ar/toxicidade , Colinesterases/sangue , Dimetoato/análogos & derivados , Exposição Ocupacional/análise , Polimorfismo Genético , Proteínas de Ligação a Telômeros/genética , Adulto , China , Dimetoato/toxicidade , Eritrócitos/enzimologia , Genótipo , Humanos , Exposição Ocupacional/efeitos adversos , Reação em Cadeia da Polimerase/métodos , Polimorfismo de Fragmento de Restrição , Adulto Jovem
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