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1.
BMC Plant Biol ; 20(1): 177, 2020 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-32321422

RESUMO

BACKGROUND: Curd architecture is one of the most important characters determining the curd morphology of cauliflower. However, the genetic mechanism dissection of this complex trait at molecular level is lacking. Genes/QTLs responsible for the morphological differences between present-day loose-curd and compact-curd cauliflower haven't been well revealed. RESULTS: Herein, by using a common compact-curd parent and two loose-curd parents, we developed two double haploid (DH) populations including 122 and 79 lines, respectively. For each population, we decomposed the curd architecture concept into four parameters (basal diameter, stalk length, stalk angle and curd solidity), and collected corresponding phenotypic data for each parameter across two environments. The Kosambi function and composite interval mapping algorithm were conducted to construct the linkage map and analyze the QTLs associated with curd architecture parameters. A total of 20 QTLs were detected with the minimum likelihood of odd (LOD) values ranging from 2.61 to 8.38 and the percentage of the phenotypic variance explained by each QTL (PVE) varying between 7.69 and 25.10%. Of these, two QTLs controlling stalk length (qSL.C6-1, qSL.C6-2) and two QTLs controlling curd solidity (qCS.C6-1 and qCS.C6-2) were steadily expressed in both environments. Further, qSL.C6-1, qSL.C6-2, qCS.C6-1 and qCS.C6-4 fell into the same chromosomal region of the reference genome, indicating that these loci are involved in pleiotropic effects or are tightly linked. CONCLUSION: The current study identified a series of QTLs associated with curd architecture parameters, which might contribute essentially to the formation of present-day loose-curd cauliflower that is widely cultivated in China. These results may pave the way for intensive deciphering the molecular mechanisms of curd development and for marker-assisted selection of curd morphology in cauliflower breeding.


Assuntos
Brassica/genética , Flores/crescimento & desenvolvimento , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas , Brassica/crescimento & desenvolvimento , Mapeamento Cromossômico , Flores/genética
2.
Lancet Oncol ; 20(11): e619-e626, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31674320

RESUMO

As a result of recent, substantial capacity building, a new landscape for cancer drug trials is emerging in China. However, data on the characteristics of cancer drug trials, and how they have changed over time, are scarce. Based on clinical trials published on the China Food and Drug Administration Registration and Information Disclosure Platform for Drug Clinical Studies, we aimed to systematically review changes over time in clinical trials of cancer drugs in mainland China from 2009 to 2018, to provide insight on the effectiveness of the pharmaceutical industry and identify unmet clinical needs of stakeholders. A total of 1493 trials of 751 newly tested cancer drugs were initiated. Increases over time were observed for the annual number of initiated trials, newly tested drugs, and newly added leading clinical trial units, with a sharp increase after 2016. Of the 1385 trials in which cancer types were identified, solid tumours (325 [23%] trials), non-small-cell lung cancer (232 [17%]), and lymphoma (126 [9%]) were the most common. A markedly uneven distribution was also observed in the geography of leading units with the largest number of leading units located in east China (50 [41%]) and the smallest number located in southwest China (4 [3%]). The growth trends we observed illustrate the progress in and increasing capability of cancer drug research and development achieved in mainland China over the decade from 2009. The low number of clinical trials on tumours with epidemiological characteristics unique to the Chinese population and the unbalanced geographical distribution of leading clinical trial units will provide potential targets for policy makers and other stakeholders. Further research efforts should address cancers uniquely relevant to Chinese populations, globally rare cancers, and the balance between equitable drug access, efficiency, and sustainability of cancer drug research and development in mainland China.


Assuntos
Antineoplásicos/uso terapêutico , Ensaios Clínicos como Assunto , Desenvolvimento de Medicamentos/tendências , Oncologia/tendências , Neoplasias/tratamento farmacológico , Projetos de Pesquisa/tendências , Antineoplásicos/efeitos adversos , China/epidemiologia , Difusão de Inovações , Humanos , Neoplasias/diagnóstico , Neoplasias/epidemiologia , Fatores de Tempo , Resultado do Tratamento
3.
J Cell Biochem ; 120(6): 10195-10204, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30565728

RESUMO

The aim of the present study was to identify the functional role of galectin-3 (Gal-3) in lipopolysaccharide (LPS)-induced injury in ATDC5 cells and to explore the probable molecular mechanisms. Here, we identified that LPS is sufficient to enhance the expression of Gal-3 in ATDC5 cells. In addition, repression of Gal-3 obviously impeded LPS-stimulated inflammation damage as exemplified by a reduction in the release of inflammatory mediators interleukin (IL)-1ß, IL-6, and tumor necrosis factor-α, as well as the production of nitric oxide and prostaglandin E2 (PGE2) concomitant with the downregulation of matrix metalloproteinases (MMP)-13 and MMP-3 expression in ATDC5 cells after LPS administration. Moreover, ablation of Gal-3 dramatically augmented cell ability and attenuated cell apoptosis accompanied by an increase in the expression of antiapoptotic protein Bcl-2 and a decrease in the expression of proapoptotic protein Bax and caspase-3 in ATDC5 cells subjected with LPS. Importantly, we observed that forced expression of TLR4 or blocked PPAR-γ with the antagonist GW9662 effectively abolished Gal-3 inhibition-mediated anti-inflammatory and antiapoptosis effects triggered by LPS. Mechanistically, depletion of Gal-3 prevents the NF-κB signaling pathway. Taken together, these findings indicated that the absence of Gal-3 exerted chondroprotective properties dependent on TLR4 and PPAR-γ-mediated NF-κB signaling, indicating that Gal-3 functions as a protector in the development and progression of osteoarthritis.


Assuntos
Condrócitos/efeitos dos fármacos , Galectina 3/deficiência , Lipopolissacarídeos/farmacologia , NF-kappa B/metabolismo , PPAR gama/metabolismo , Receptor 4 Toll-Like/metabolismo , Anilidas/farmacologia , Animais , Apoptose/efeitos dos fármacos , Proteínas Reguladoras de Apoptose/metabolismo , Linhagem Celular Tumoral , Condrócitos/metabolismo , Condrócitos/patologia , Citocinas/metabolismo , Galectina 3/genética , Mediadores da Inflamação/metabolismo , Metaloproteinase 1 da Matriz/metabolismo , Metaloproteinase 13 da Matriz/metabolismo , Osteoartrite/genética , Osteoartrite/metabolismo , Osteoartrite/patologia , PPAR gama/antagonistas & inibidores , Interferência de RNA , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética
4.
BMC Plant Biol ; 19(1): 106, 2019 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-30890145

RESUMO

BACKGROUND: MADS-box genes play important roles in vegetative growth and reproductive development and are essential for the correct development of plants (particularly inflorescences, flowers, and fruits). However, this gene family has not been identified nor their functions analyzed in Brassica oleracea. RESULTS: In this study, we performed a whole-genome survey of the complete set of MADS-box genes in B. oleracea. In total, 91 MADS-box transcription factors (TFs) were identified and categorized as type I (Mα, Mß, Mγ) and type II (MIKCC, MIKC*) groups according to the phylogeny and gene structure analysis. Among these genes, 59 were randomly distributed on 9 chromosomes, while the other 23 were assigned to 19 scaffolds and 9 genes from NCBI had no location information. Both RNA-sequencing and quantitative real-time-PCR analysis suggested that MIKC genes had more active and complex expression patterns than M type genes and most type II genes showed high flowering-related expression profiles. Additional quantitative real-time-PCR analysis of pedicel and four flower whorls revealed that the structure of the B.oleracea MIKC genes was conserved, but their homologues showed variable expression patterns compared to those in Arabidopsis thaliana. CONCLUSION: This paper gives a detailed overview of the BolMADS genes and their expression patterns. The results obtained in this study provide useful information for understanding the molecular regulation of flower development and further functional characterization of MADS-box genes in B. oleracea.


Assuntos
Brassica/genética , Flores/crescimento & desenvolvimento , Genoma de Planta , Proteínas de Domínio MADS/genética , Brassica/crescimento & desenvolvimento , Brassica/metabolismo , Cromossomos de Plantas , Flores/metabolismo , Proteínas de Domínio MADS/metabolismo , Filogenia
5.
Phys Chem Chem Phys ; 21(47): 26033-26040, 2019 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-31746866

RESUMO

We study the lattice thermal conductivity of two-dimensional (2D) pentagonal systems, such as penta-silicene and penta-germanene. Penta-silicene has been recently reported, while the stable penta-germanene, made up of another group IV element, is first revealed by our ab initio calculations. We find that both penta-silicene and penta-germanene at room temperature have ultra-low lattice thermal conductivities, κ, of 1.29 W m-1 K-1 and 0.30 W m-1 K-1, respectively. To the best of our knowledge, penta-germanene may have the lowest κ in 2D crystal materials. We attribute the ultra-low κ to the weak phonon harmonic interaction and strong anharmonic scattering. A small phonon group velocity, a small Debye frequency, a large Grüneisen parameter, and a large number of modes available for phonon-phonon interplay together lead to the ultra-low κ of penta-silicene and penta-germanene. These discoveries provide new insight into the manipulation of ultra-low κ in 2D materials and highlight the potential applications of silicon and germanium based high thermoelectric materials.

6.
World J Surg Oncol ; 17(1): 46, 2019 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-30849987

RESUMO

BACKGROUND: Osteosarcoma is the most common bone tumor that occurs in children. METHODS: To identify co-expression modules and pathways correlated with osteosarcoma and its clinical characteristics, we performed weighted gene co-expression network analysis (WGCNA) on RNA-seq data of osteosarcoma with 52 samples. Then we performed pathway enrichment analysis on genes from significant modules. RESULTS: A total of 5471 genes were included in WGCNA, and 16 modules were identified. Module-trait analysis identified that a module involved in microtubule bundle formation, drug metabolism-cytochrome P450, and IL-17 signaling pathway was negatively correlated with osteosarcoma and positively correlated with metastasis; a module involved in DNA replication was positively correlated with osteosarcoma; a module involved in cell junction was positively correlated with metastasis; and a module involved in heparin binding negatively correlated with osteosarcoma. Moreover, expression levels in four of the top ten differentially expressed genes were validated in another independent dataset. CONCLUSIONS: Our analysis might provide insight for molecular mechanisms of osteosarcoma.


Assuntos
Neoplasias Ósseas/genética , Perfilação da Expressão Gênica , Osteossarcoma/genética , Osteossarcoma/secundário , Neoplasias Ósseas/metabolismo , Neoplasias Ósseas/patologia , Expressão Gênica , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Metástase Neoplásica , Osteossarcoma/metabolismo , Prognóstico
7.
J Am Chem Soc ; 140(41): 13200-13204, 2018 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-30277067

RESUMO

It is generally deemed that doping is a must for polymeric materials to achieve their high thermoelectric performance. We herein present the first report that intrinsically metallic behaviors and high-performance thermoelectric power factors can coexist within doping-free linear-backbone conducting polymers, poly(nickel-ethylenetetrathiolate) and its analogs. On the basis of density functional calculations, we have corroborated that four crystalline π- d conjugated transition-metal coordination polymers, including poly(Ni-C2S4), poly(Ni-C2Se4), poly(Pd-C2S4) and poly(Pt-C2S4) exhibit intrinsically metallic behavior arising from the formation of dense intermolecular interaction networks between sulfur/selenium atoms. They show moderate carrier concentrations (1019-1021 cm-3) and decent conductivities (103-104 S cm-1), among which, poly(Ni-C2S4), poly(Ni-C2Se4) and poly(Pd-C2S4) possess high power factors (∼103 µW m-1 K-2).

8.
Biochem Genet ; 55(5-6): 347-366, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28478603

RESUMO

Inter simple sequence repeat (ISSR) and simple sequence repeat (SSR) markers were used to assess the genetic diversity of 36 pineapple accessions that were introduced from 10 countries/regions. Thirteen ISSR primers amplified 96 bands, of which 91 (93.65%) were polymorphic, whereas 20 SSR primers amplified 73 bands, of which 70 (96.50%) were polymorphic. Nei's gene diversity (h = 0.28), Shannon's information index (I = 0.43), and polymorphism information content (PIC = 0.29) generated using the SSR primers were higher than that with ISSR primers (h =  0.23, I = 0.37, PIC = 0.24), thereby suggesting that the SSR system is more efficient than the ISSR system in assessing genetic diversity in various pineapple accessions. Mean genetic similarities were 0.74, 0.61, and 0.69, as determined using ISSR, SSR, and combined ISSR/SSR, respectively. These results suggest that the genetic diversity among pineapple accessions is very high. We clustered the 36 pineapple accessions into three or five groups on the basis of the phylogenetic trees constructed based on the results of ISSR, SSR, and combined ISSR/SSR analyses using the unweighted pair-group with arithmetic averaging (UPGMA) method. The results of principal components analysis (PCA) also supported the UPGMA clustering. These results will be useful not only for the scientific conservation and management of pineapple germplasm but also for the improvement of the current pineapple breeding strategies.


Assuntos
Ananas/genética , Filogenia , Polimorfismo Genético , Sequências Repetitivas de Ácido Nucleico
9.
Phys Rev Lett ; 114(9): 096801, 2015 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-25793838

RESUMO

We investigate theoretically the interplay of current-induced forces (CIFs), Joule heating, and heat transport inside a current-carrying nanoconductor. We find that the CIFs, due to the electron-phonon coherence, can control the spatial heat dissipation in the conductor. This yields a significant asymmetric concentration of excess heating (hot spot) even for a symmetric conductor. When coupled to the electrode phonons, CIFs drive different phonon heat flux into the two electrodes. First-principles calculations on realistic biased nanojunctions illustrate the importance of the effect.

10.
J Chem Phys ; 141(19): 194101, 2014 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-25416868

RESUMO

We present a general theory to calculate the steady-state heat and electronic currents for nonlinear systems using a perturbative expansion in the system-bath coupling. We explicitly demonstrate that using the truncated Dyson-series leads to divergences in the steady-state limit, thus making it impossible to be used for actual applications. In order to resolve the divergences, we propose a unique choice of initial condition for the reduced density matrix, which removes the divergences at each order. Our approach not only allows us to use the truncated Dyson-series, with a reasonable choice of initial condition, but also gives the expected result that the steady-state solutions should be independent of initial preparations. Using our improved Dyson series we evaluate the heat and electronic currents up to fourth-order in system-bath coupling, a considerable improvement over the standard quantum master equation techniques. We then numerically corroborate our theory for archetypal settings of linear systems using the exact nonequilibrium Green's function approach. Finally, to demonstrate the advantage of our approach, we deal with the nonlinear spin-boson model to evaluate heat current up to fourth-order and find signatures of cotunnelling process.


Assuntos
Dinâmica não Linear , Teoria Quântica , Eletrônica , Temperatura Alta
11.
Guang Pu Xue Yu Guang Pu Fen Xi ; 34(7): 1816-20, 2014 Jul.
Artigo em Zh | MEDLINE | ID: mdl-25269287

RESUMO

The present paper puts forth a new spectral correction method based on quasi-linear expression and local weighted function. The first stage of the method is to search 3 quasi-linear expressions to replace the original linear expression in MSC method, such as quadratic, cubic and growth curve expression. Then the local weighted function is constructed by introducing 4 kernel functions, such as Gaussian, Epanechnikov, Biweight and Triweight kernel function. After adding the function in the basic estimation equation, the dependency between the original and ideal spectra is described more accurately and meticulously at each wavelength point. Furthermore, two analytical models were established respectively based on PLS and PCA-BP neural network method, which can be used for estimating the accuracy of corrected spectra. At last, the optimal correction mode was determined by the analytical results with different combination of quasi-linear expression and local weighted function. The spectra of the same coal sample have different noise ratios while the coal sample was prepared under different particle sizes. To validate the effectiveness of this method, the experiment analyzed the correction results of 3 spectral data sets with the particle sizes of 0.2, 1 and 3 mm. The results show that the proposed method can eliminate the scattering influence, and also can enhance the information of spectral peaks. This paper proves a more efficient way to enhance the correlation between corrected spectra and coal qualities significantly, and improve the accuracy and stability of the analytical model substantially.

12.
BMC Cancer ; 13: 546, 2013 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-24237755

RESUMO

BACKGROUND: The chemotherapy resistance of non-small cell lung cancer (NSCLC) remains a clinic challenge and is closely associated with several biomarkers including epidermal growth factor receptor (EGFR) ( Drugs 72(Suppl 1):28-36, 012.), p53 ( Med Sci Monit 11(6):HY11-HY20, 2005.) and excision repair cross complementing gene 1 (ERCC1) ( J Thorac Oncol 8(5):582-586, 2013.). Fluorodeoxyglucose positron emission tomography (FDG-PET) is the best non-invasive surrogate for tumor biology with the maximal standardized uptake values (SUVmax) being the most important paradigm. However, there are limited data correlating FDG-PET with the chemotherapy resistant tumor markers. The purpose of this study was to determine the correlation of chemotherapy related tumor marker expression with FDG-PET SUVmax in NSCLC. METHODS: FDG-PET SUVmax was calculated in chemotherapy naïve patients with NSCLC (n=62) and immunohistochemical analysis was performed for EGFR, p53 or ERCC1 on the intraoperative NSCLC tissues. Each tumor marker was assessed independently by two pathologists using common grading criteria. The SUVmax difference based on the histologic characteristics, gender, differentiation, grading and age as well as correlation analysis among these parameters were performed. Multiple stepwise regression analysis was further performed to determine the primary predictor for SUVmax and the receiver operating characteristics (ROC) curve analysis was performed to detect the optimized sensitivity and specificity for SUVmax in suggesting chemotherapy resistant tumor markers. RESULTS: The significant tumor type (P=0.045), differentiation (P=0.021), p53 (P=0.000) or ERCC1 (P=0.033) positivity dependent differences of SUVmax values were observed. The tumor differentiation is significantly correlated with SUVmax (R=-0.327), tumor size (R=-0.286), grading (R=-0.499), gender (R=0.286) as well as the expression levels for p53 (R= -0.605) and ERCC1 (R=-0.644). The expression level of p53 is significantly correlated with SUVmax (R=0.508) and grading (R=0.321). Furthermore, multiple stepwise regression analysis revealed that p53 expression was the primary predictor for SUVmax. When the cut-off value of SUVmax was set at 5.15 in the ROC curve analysis, the sensitivity and specificity of SUVmax in suggesting p53 positive NSCLC were 79.5% and 47.8%, respectively. CONCLUSION: The current study suggests that SUVmax of primary tumor on FDG-PET might be a simple and good non-invasive method for predicting p53-related chemotherapy resistance in NSCLC when we set the cu-off value of SUVmax at 5.15.


Assuntos
Biomarcadores Tumorais/genética , Carcinoma Pulmonar de Células não Pequenas/diagnóstico , Carcinoma Pulmonar de Células não Pequenas/genética , Resistencia a Medicamentos Antineoplásicos/genética , Fluordesoxiglucose F18 , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/genética , Tomografia por Emissão de Pósitrons , Adulto , Idoso , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Endonucleases/genética , Endonucleases/metabolismo , Feminino , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/mortalidade , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Estadiamento de Neoplasias , Curva ROC , Tomografia Computadorizada por Raios X , Carga Tumoral , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo
13.
Guang Pu Xue Yu Guang Pu Fen Xi ; 33(11): 2935-9, 2013 Nov.
Artigo em Zh | MEDLINE | ID: mdl-24555355

RESUMO

The purpose of the present study was to compare the changes of infrared spectrum of breast cancer cell line MCF-7 treated by 5-fluorouracil with various concentrations and treating time. The results indicate that the relative intensity ratios of I2 920/I1 460 increased in the FTIR spectra of cell line MCF-7 while I1 400/I1 460, I1 080 /I1 550 and I1 240/I1 550 decreased significantly within forty-eight hours, however, no regular change was observed during 48-72 hours. The relative intensity ratio of I1 640/ I1 550 decreases along with the increase in the concentration of 5-fluorouracil. The changes of infrared spectra are consistent with the biochemical changes in breast cancer cell, and it can be the reference designators when assessing curative effect of breast cancer cell by FTIR spectrometry.


Assuntos
Neoplasias da Mama/metabolismo , Linhagem Celular Tumoral/efeitos dos fármacos , Fluoruracila , Espectroscopia de Infravermelho com Transformada de Fourier , Humanos
14.
Zhonghua Wai Ke Za Zhi ; 51(3): 216-20, 2013 Mar.
Artigo em Zh | MEDLINE | ID: mdl-23859321

RESUMO

OBJECTIVE: To evaluate the feasibility and efficiency of embolization of spinal dural arteriovenous fistula (SDAVF). METHODS: From December 2010 to May 2012, there were 104 cases of SDAVF were treated, and 26 cases were selected to be treated with embolization. The inclusion criteria was as follows: (1) No anterior or posterior spinal artery originated from the fistula segment; (2) The segmental artery can be catheterized with guiding or micro catheter; (3) High flow in fistula; (4) Patient's situation was not suitable for surgery or general anesthesia. Among 26 cases, there were 22 male and 4 female patients, the average age was 55.9 years (ranged from 34 to 81 years). The locations of SDAVF were 10 cases in thoracic, 9 in lumbar and 7 in sacral segment. The main symptoms were progressive numbness and weakness in both lower extremities, most cases accompanied with difficulties in urination and defecation. The average history was 17.1 months (from 1 to 156 months). ONYX-18 liquid embolic agent or Glubran-2 surgical glue were used as embolic material. The patients not cured with embolization were treated with surgery in the following 1 - 2 weeks. Follow-up evaluation was done with MRI after 3 months and DSA after 6 months, besides physical examination. RESULTS: Fifteen from 26 cases achieved immediate angiographic cure results: 14 in 20 cases which embolized with ONYX-18; only 1 in 6 cases with Glubran-2. Three in 10 cases of thoracic SDAVF and 12 in 16 cases of lumbar/sacral SDAVF were cured with embolization. Partially embolized cases were treated with surgical obliteration of drainage veins within 2 weeks. Cured patients experienced immediate improvement after embolization and kept getting better in the follow-up. All the patients had MRI follow-up after 3 months and DSA follow-up after 6 months. In 6 month's follow-up, MRI showed the edema and flow void signal in the spinal cord disappeared. DSA showed no fistula recurrence or remnant. There was no deterioration case in all of the embolized cases. CONCLUSIONS: Particular SDAVF is suitable for embolization with ONYX-18. Most lesions located in lumbar and sacral segment are good indications for embolization.


Assuntos
Malformações Vasculares do Sistema Nervoso Central/terapia , Embolização Terapêutica/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
15.
J Am Coll Nutr ; 31(5): 375-84, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23529995

RESUMO

BACKGROUND: The aim of this study was to investigate the relationships among Helicobacter pylori, dietary factors, and the risk of noncardia gastric cancer in a hospital-based case-control study in China. METHODS: A case-control study of noncardia gastric cancer was performed at 3 hospitals in Xi'an, China, between September 2008 and July 2010. Participants were 257 men and women with histologically diagnosed primary noncardia gastric cancer and 514 sex- and age-matched (± 5 years) control subjects selected from the communities where the cases were living when diagnosed. A questionnaire was used to obtain information regarding potential risk factors, including diet, and blood samples were obtained to examine H pylori infection status. RESULTS: Positive H pylori status (odds ratio [OR], 3.2; 95% confidence interval [CI], 0.8-5.9) and high consumption of pickled foods (OR, 27.1; 95%, 8.7-79.1) appeared to increase the risk of noncardia gastric cancer, whereas high consumption of vegetables (OR, 0.3; 95% CI, 0.1-0.89), fruits (OR, 0.2; 95% CI, 0.09-0.81), and soya products (OR, 0.04; 95% CI, 0.01-0.3) appeared to decrease the risk. Consumption of meat, cereals, tubers, eggs, oils, nuts, fish, fresh fruit, and red meat was not clearly associated with risk. Effect modification was observed, such that a relatively high consumption of fruit and vegetables appeared to attenuate the association of H pylori with risk of noncardia gastric cancer (p < 0.05). CONCLUSIONS: Our data suggest that noncardia gastric cancer is highly preventable through modifications in dietary habits. Given the prevalence of H pylori infection worldwide, information regarding potential interaction between H pylori and lifestyle factors in gastric cancer development, including the dietary factors examined in our study, may prove valuable in future efforts at prevention.


Assuntos
Dieta , Comportamento Alimentar , Infecções por Helicobacter/epidemiologia , Neoplasias Gástricas/epidemiologia , Neoplasias Gástricas/microbiologia , Adulto , Idoso , Estudos de Casos e Controles , China , Feminino , Frutas , Infecções por Helicobacter/complicações , Infecções por Helicobacter/microbiologia , Infecções por Helicobacter/prevenção & controle , Humanos , Estilo de Vida , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Prevalência , Medição de Risco , Fatores de Risco , Alimentos de Soja , Neoplasias Gástricas/etiologia , Neoplasias Gástricas/prevenção & controle , Inquéritos e Questionários , Verduras
16.
J Chem Phys ; 136(19): 194110, 2012 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-22612083

RESUMO

A novel scheme for the steady state solution of the standard Redfield quantum master equation is developed which yields agreement with the exact result for the corresponding reduced density matrix up to second order in the system-bath coupling strength. We achieve this objective by use of an analytic continuation of the off-diagonal matrix elements of the Redfield solution towards its diagonal limit. Notably, our scheme does not require the provision of yet higher order relaxation tensors. Testing this modified method for a heat bath consisting of a collection of harmonic oscillators we assess that the system relaxes towards its correct coupling-dependent, generalized quantum Gibbs state in second order. We numerically compare our formulation for a damped quantum harmonic system with the nonequilibrium Green's function formalism: we find good agreement at low temperatures for coupling strengths that are even larger than expected from the very regime of validity of the second-order Redfield quantum master equation. Yet another advantage of our method is that it markedly reduces the numerical complexity of the problem; thus, allowing to study efficiently large-sized system Hilbert spaces.

17.
Nano Lett ; 11(1): 214-9, 2011 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-21158401

RESUMO

We use density-functional theory and the nonequilibrium Green's function method as well as phonon dispersion calculations to study the thermal conductance of graphene nanoribbons with armchair and zigzag edges, with and without hydrogen passivation. We find that low-frequency phonon bands of the zigzag ribbons are more dispersive than those of the armchair ribbons and that this difference accounts for the anisotropy in the thermal conductance of graphene nanoribbons. Comparing our results with data on large-area graphene, edge effects are shown to contribute to thermal conductance, enhance the anisotropy in thermal conductance of graphene nanoribbons, and increase thermal conductance per unit width. The edges with and without hydrogen passivation modify the atomic structure and ultimately influence the phonon thermal transport differently for the two ribbon types.

18.
Zhonghua Yi Xue Za Zhi ; 92(22): 1547-9, 2012 Jun 12.
Artigo em Zh | MEDLINE | ID: mdl-22944059

RESUMO

OBJECTIVE: To explore the risk factors of contrast-induced nephropathy (CIN) in patients after coronary artery intervention. METHODS: A total of 637 patients undergoing diagnostic coronary angiography or percutaneous coronary intervention were enrolled. They were divided into the CIN and non-CIN groups according to the changes in serum creatinine levels within 48 hours after coronary artery intervention. Then the relevant risk factors of CIN were analyzed. RESULTS: Among them, CIN occurred in 49 patients with an incidence of 7.7%. The patients with diabetes and renal insufficiency had higher incidence of CIN at 15.5% and 22.5% respectively. Logistic regression analysis showed that the risk factors of CIN included advanced age, smoking, diabetes, renal insufficiency, hypercholesterolemia and hyperuricemia. CONCLUSION: For the patients of coronary artery intervention, the major risk factors of CIN are advanced age, diabetes and renal insufficiency.


Assuntos
Meios de Contraste/efeitos adversos , Angiografia Coronária/efeitos adversos , Nefropatias/induzido quimicamente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco
19.
Electrophoresis ; 32(5): 506-17, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21341285

RESUMO

We present a theoretical model for describing the electric field-driven migration and dispersion of short anisotropic molecules in nanofluidic filter arrays. The model uses macrotransport theory to derive exact integral-form expressions for the effective mobility and diffusivity of Brownian particles moving in an effective one-dimensional energy landscape. The latter is obtained by modeling the anisotropic molecules as point-sized Brownian particles with their orientational degrees of freedom accounted for by an entropy penalty term, and using a systematic projection procedure for reducing the system dimensionality to the device axial dimension. Our analytical results provide guidance for the design and optimization of nanofluidic separation systems without the need for complex numerical simulations. Comparison with numerical solution of the macrotransport equations in the actual, effectively two-dimensional, geometry shows that the one-dimensional model faithfully describes the field- and size-dependences of mobility and diffusivity, with maximum difference on the order of 10% under the experimentally relevant electric fields.


Assuntos
Eletroforese/métodos , Técnicas Analíticas Microfluídicas/métodos , Modelos Químicos , Anisotropia , DNA/isolamento & purificação , Filtração
20.
ACS Appl Mater Interfaces ; 13(31): 37527-37534, 2021 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-34333972

RESUMO

Anisotropy in crystals usually has remarkable consequences in two-dimensional (2D) materials, for example, black phosphorus, PdSe2, and SnS, arising from different lattice periodicities along different crystallographic directions. Electrical anisotropy has been successfully demonstrated in 2D materials, but anisotropic magnetoresistance in 2D materials is rarely studied. Herein, we report anisotropic magnetoresistance in layered nonmagnetic semiconducting PdSe2 flakes. Anisotropic magnetoresistance along the two crystalline axes under a perpendicular magnetic field is demonstrated, and the magnetoresistance along the a-axis is apparently different from the magnetoresistance along the b-axis. The magnetoresistance can also be flexibly tuned by applying a gate voltage, leveraging the semiconductor properties of PdSe2. The computed anisotropic electronic density of states and electronic mobility with ab initio density functional calculations support the anisotropic and measured magnetoresistance. Our findings advance the understanding of magnetoresistance in anisotropic transition-metal dichalcogenides and pave the way for potential applications in anisotropic spintronic devices.

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