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1.
J Synchrotron Radiat ; 29(Pt 4): 931-938, 2022 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-35787558

RESUMO

High-resolution inelastic X-ray scattering is an established technique in the synchrotron community, used to investigate collective low-frequency responses of materials. When fielded at hard X-ray free-electron lasers (XFELs) and combined with high-intensity laser drivers, it becomes a promising technique for investigating matter at high temperatures and high pressures. This technique gives access to important thermodynamic properties of matter at extreme conditions, such as temperature, material sound speed, and viscosity. The successful realization of this method requires the acquisition of many identical laser-pump/X-ray-probe shots, allowing the collection of a sufficient number of photons necessary to perform quantitative analyses. Here, a 2.5-fold improvement in the energy resolution of the instrument relative to previous works at the Matter in Extreme Conditions (MEC) endstation, Linac Coherent Light Source (LCLS), and the High Energy Density (HED) instrument, European XFEL, is presented. Some aspects of the experimental design that are essential for improving the number of photons detected in each X-ray shot, making such measurements feasible, are discussed. A careful choice of the energy resolution, the X-ray beam mode provided by the XFEL, and the position of the analysers used in such experiments can provide a more than ten-fold improvement in the photometrics. The discussion is supported by experimental data on 10 µm-thick iron and 50 nm-thick gold samples collected at the MEC endstation at the LCLS, and by complementary ray-tracing simulations coupled with thermal diffuse scattering calculations.

2.
Phys Rev Lett ; 127(9): 097403, 2021 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-34506197

RESUMO

We report on the study of electron kinetics induced by intense femtosecond (fs) laser excitation of electrons in the 5d band of Au. Changes in the electron system are observed from the temporal evolution of ac conductivity and conduction electron density. The results reveal an increase of electron thermalization time with excitation energy density, contrary to the Fermi-liquid behavior of the decrease of thermalization time associated with the heating of conduction electrons. This is attributed to the severe mitigation of photoexcitation by Auger decay. The study also uncovers the shortening of 5d hole lifetime with the increase of photoexcitation rates. These unique findings provide valuable insights for understanding electron kinetics under extreme nonequilibrium conditions.

3.
Zhonghua Zhong Liu Za Zhi ; 42(8): 629-634, 2020 Aug 23.
Artigo em Zh | MEDLINE | ID: mdl-32867453

RESUMO

Objective: To investigate the effect of esculin on the proliferation of triple negative breast cancer cells and its molecular mechanism. Methods: MDA-MB-231 cells were treated with 28, 56, 112, 225, 450 and 900 µmol/L of esculin for 24, 48 and 72 h, respectively, and the cell viability was detected by cell counting kit 8 (CCK-8) assay. In addition, MDA-MB-231 cells were treated with 0, 225, 450 and 900 µmol/L of esculin for 48 h. And then the changes in cell morphology were observed by inverted microscope. The clone-forming ability was detected by colony formation assay. The mRNA expression levels of FBI-1, p53 and p21 were detected using real-time fluorescence quantitative polymerase chain reaction. The protein expression levels of FBI-1, p53, p21 and Ki67 were detected by western blot. Results: Compared with the blank control group, the cell viability of MDA-MB-231 cells that treated with esculin significantly decreased in a dose-dependent and time-dependent manners. After treatment with esculin, MDA-MB-231 cells shrunk, flattened, adhered poorly to the culture dish and the cell spacing became larger. Meanwhile, shedding and incomplete cells appeared, of which 900 µmol/L of esculin treatment group showed the most dramatic changes. In addition, the colony formation ratios were decreased to (77.18±5.13)%, (65.94±4.98)% and (45.92±3.70)% in the 225, 450 and 900 µmol/L of esculin treatment groups compared with blank control, respectively (P<0.01). Furthermore, the mRNA and protein expressions of FBI-1 increased, while the levels of p53 and p21 mRNA and protein, as well as the protein expression of Ki67 decreased in a concentration-dependent manner (P<0.01). Conclusion: Esculin may regulate cell cycle-related p53-p21 pathway via FBI-1 mediated DNA replication, thus inhibit the proliferation of triple negative breast cancer cells.


Assuntos
Neoplasias da Mama/patologia , Proliferação de Células/efeitos dos fármacos , Esculina/farmacologia , RNA Mensageiro/genética , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/genética , Neoplasias da Mama/metabolismo , Ciclo Celular , Linhagem Celular Tumoral , Proteínas de Ligação a DNA , Regulação para Baixo/efeitos dos fármacos , Feminino , Humanos , Fatores de Transcrição , Neoplasias de Mama Triplo Negativas/patologia
4.
Zhonghua Zhong Liu Za Zhi ; 41(5): 346-350, 2019 May 23.
Artigo em Zh | MEDLINE | ID: mdl-31137167

RESUMO

Objective: To explore the feasibility of 7, 12-dimethylbenz[a] anthracene (DMBA) induced tree shrew breast cancer model, and compare the effects of two administration modes by gavage and mammary gland injection. Methods: A total of 40 tree shrews were randomly divided into two groups (20 animals per group): DMBA gavage group and mammary gland injection group. DMBA was dissolved in edible vegetable oil. For gavage group, tree shrews were administered with DMBA solutions (15 mg/kg) by gavage once a day. For mammary gland injection group, DMBA solution (10 mg/kg) was injected into the mammary fat pad of tree shrews, and the injection was performed for a total of 3 times. From the first administration of DMBA, medroxyprogesterone acetate (MPA, 100 mg/kg) was intramuscularly injected into the muscles of the lateral thighs of tree shrews at the same time, for a total of 5 times. The tumorigenesis and survival of tree shrews were monitored. The tumor histological morphology was observed by HE staining. The expression of estrogen receptor (ER), progesterone receptor (PR), cytokeratin5/6 (CK5/6) and human epidermal factor receptor-2 (HER-2) was detected by immunohistochemical staining. Results: In the gavage group, there were 10 deaths, and 4 tree shrews developed mammary tumors with 20.0% (4/20) tumor formation rate. The success rate of mammary cancer modeling was 10.0% (2/20), and the tumor formation time was 197.3±15.1 days. In the mammary gland injection group, there were 8 tree shrews died, and 9 tree shrews formed tumors with 45.0% (9/20) tumor formation rate. The success rate of mammary cancer modeling was 40.0% (8/20), and the tumor formation time was 71.8±19.0 days. There was no significant difference in mortality and tumor formation rate (P>0.05) between the two groups (all P>0.05). However, in the mammary gland injection group, the success rate of mammary cancer modeling was significantly higher than that in the gavage group (P<0.05), whereas the tumor formation time was markedly shorter than that in the gavage group (P<0.01). The pathological types in the gavage group included ductal hyperplasia, intraductal papilloma and ductal carcinoma in situ, while those in the breast injection group included intraductal papilloma and ductal carcinoma in situ. In both groups, immunohistochemical staining showed the negative expression of HER-2 but positive expression of ER, PR and CK5/6 with varying degrees. Conclusion: Both the DMBA gavage and mammary gland injection can successfully establish the tree shrew breast cancer model, and the modeling effect of mammary gland injection is better than gavage.


Assuntos
9,10-Dimetil-1,2-benzantraceno/toxicidade , Neoplasias da Mama/patologia , Modelos Animais de Doenças , Neoplasias Mamárias Experimentais/induzido quimicamente , 9,10-Dimetil-1,2-benzantraceno/administração & dosagem , Administração Oral , Animais , Neoplasias da Mama/induzido quimicamente , Carcinógenos/administração & dosagem , Carcinógenos/toxicidade , Feminino , Injeções , Distribuição Aleatória , Tupaiidae
5.
Zhonghua Wai Ke Za Zhi ; 57(9): 681-685, 2019 Sep 01.
Artigo em Zh | MEDLINE | ID: mdl-31474060

RESUMO

Objectives: To examine the influence factors on axillary evaluation in ductal carcinoma in situ (DCIS) patients, and the prognosis of different choices of axillary evaluation in a single-center retrospective study. Methods: Totally 1 557 DCIS patients admitted in Department of Breast Surgery, Fudan University Shanghai Cancer Center from January 2006 to November 2016 were retrospectively enrolled. All patients were female. The median age was 49 years (range: 21 to 85 years). Surgical methods included modified radical mastectomy, simple mastectomy (with or without axillary evaluation) and breast conservation surgery (with or without axillary evaluation). Axillary evaluation included axillary lymph node dissection (ALND) and sentinel lymph node biopsy (SLNB). T tests, χ(2) test and Logistic regression analysis was used to analyze influence factors on axillary evaluation, respectively. Kaplan-Meier curve and Log-rank analysis were used to evaluate recurrence-free survival (RFS) and loco-regional recurrence-free survival (LRRFS) in patients with different surgical methods. Results: Among the 1 557 DCIS patients, there were 1 226 cases received axillary evaluation, while 331 cases not received axillary evaluation. Patients were separated into 3 groups by different axillary evaluation choices: SLNB group (957 cases, 61.46%), ALND group (197 cases, 12.65%) and no evaluation group (403 cases, 25.88%). The patients in SLNB group increased significantly (P=0.000), from 3.85% (60/1 557) in 2006 to 75.19% (1 170/1 557) in 2016. The independent influence factors of receiving axillary evaluation were high nuclear grade (OR=3.191, 95%CI: 1.722 to 5.912, P=0.001) and tumor size>15 mm (OR=1.698, 95%CI: 1.120 to 2.573, P=0.012). Also, patients received breast conservation surgery were more likely to refuse axillary evaluation (OR=0.155, 95%CI: 0.103 to 0.233, P=0.000). There were no significant differences in RFS and LRRFS in patients with different axillary evaluation choices. Conclusions: The investigation in trends and influence factors of different axillary evaluation choices provided basis on surgical precision medicine in DCIS patients. Patients received SLNB increased significantly. The independent influence factors of axillary evaluation were nuclear grade, tumor size and surgical methods. There was no significant differences in prognosis among the groups receiving different axillary evaluations.


Assuntos
Axila/patologia , Neoplasias da Mama/patologia , Carcinoma Intraductal não Infiltrante/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Axila/cirurgia , Neoplasias da Mama/cirurgia , Carcinoma Intraductal não Infiltrante/cirurgia , Feminino , Humanos , Excisão de Linfonodo , Mastectomia , Pessoa de Meia-Idade , Estudos Retrospectivos , Biópsia de Linfonodo Sentinela , Adulto Jovem
6.
Ann Oncol ; 29(10): 2129-2134, 2018 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-30084933

RESUMO

Background: Previous studies have shown that industry funded trials are associated with pro-industry conclusions and publication bias. Less is known about the role of industry funders and their influence on trial conclusions and time to publication. Methods: We identified all industry funded RCTs published in six high-impact clinical journals between 2014 and 2016 to estimate the prevalence of the role of industry funders in trial design, data collection, data analyses, data interpretation and manuscript writing. Ordinal logistic regression was used to assess the association between the role of industry funders and trial conclusions, which was classified on a five-point scale. Cox proportional-hazards were used to examine the effect of role of funder on time to publication. Results: Of the 255 eligible RCTs, industry funders had a role in trial design in 179 (70.2%) trials, data collection in 160 (62.7%) trials, data analyses in 173 (67.8%) trials, data interpretation in 135 (52.9%) trials and manuscript writing in 168 (65.9%) trials. Trials with any role of industry funders had 3.6 times (95% CI 2.0-6.6) higher odds of having positive conclusions compared with those without role of industry funders. In trials with any role of industry funders, positive trials were published more rapidly than negative trials (hazard ratio = 4.3; 95% CI 2.7-6.7, P < 0.001), while for trials without role of industry funders, there was no association (hazard ratio = 1.07; 95% CI 0.57-1.99, P = 0.84). Conclusion: The involvement of industry funders is common in all stages of clinical trials and was associated with more positive conclusions and more rapid publication of RCTs with positive results.


Assuntos
Financiamento de Capital , Indústria Farmacêutica , Fator de Impacto de Revistas , Neoplasias/terapia , Publicações Periódicas como Assunto/estatística & dados numéricos , Ensaios Clínicos Controlados Aleatórios como Assunto , Apoio à Pesquisa como Assunto , Ensaios Clínicos Fase II como Assunto , Ensaios Clínicos Fase III como Assunto , Humanos , Neoplasias/economia , Projetos de Pesquisa , Fatores de Tempo
7.
Insect Mol Biol ; 27(4): 522-532, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29749087

RESUMO

Detoxication enzymes play an important role in insect resistance to xenobiotics such as insecticides and phytochemicals. We studied the pathway for activating the expression of glutathione S-transferases (GSTs) in response to selected xenobiotics. An assay of the promoter activity of GST epsilon 1 (Slgste1) of Spodoptera litura led to the discovery of a cis-regulating element. An antioxidant response element was activated in response to indole-3-carbinol (I3C) and chlorpyrifos (CPF) and was able to bind with the xenobiotic sensor protein nuclear factor erythroid-derived 2-related factor 2 (SlNrf2). SlNrf2 and Slgste1 were responsive to reactive oxygen species induced by I3C and CPF in a S. litura cell line, as well as in S. litura midguts. SlNrf2 RNA interference (RNAi) reduced the message RNA levels of Slgste1 and the peroxidase activity of GSTs in response to I3C, xanthotoxin, CPF and deltamethrin. SlNrf2 RNAi and inhibitor treatment of GST activity decreased the viability of I3C-treated cells. These results indicate that SlNrf2 activates the expression of GSTs in response to oxidative stresses caused by exposure to xenobiotics.


Assuntos
Expressão Gênica , Glutationa Transferase/metabolismo , Proteínas de Insetos/genética , Inseticidas/farmacologia , Fator 2 Relacionado a NF-E2/genética , Compostos Fitoquímicos/efeitos adversos , Spodoptera/efeitos dos fármacos , Animais , Trato Gastrointestinal/efeitos dos fármacos , Trato Gastrointestinal/metabolismo , Inativação Metabólica , Proteínas de Insetos/metabolismo , Larva/efeitos dos fármacos , Larva/enzimologia , Larva/genética , Larva/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Spodoptera/enzimologia , Spodoptera/genética , Spodoptera/metabolismo
8.
Phys Rev Lett ; 121(7): 075002, 2018 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-30169102

RESUMO

We present a new measurement of lattice disassembly times in femtosecond-laser-heated polycrystalline Au nanofoils. The results are compared with molecular dynamics simulations incorporating a highly optimized, embedded-atom-method interatomic potential. For absorbed energy densities of 0.9-4.3 MJ/kg, the agreement between the experiment and simulation reveals a single-crystal-like behavior of homogeneous melting and corroborates the applicability of the interatomic potential in the nonequilibrium warm dense matter regime. For energy densities below 0.9 MJ/kg, the measurement is consistent with nanocrystal behavior where melting is initiated at the grain boundaries.

10.
Hum Reprod ; 30(4): 893-905, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25605704

RESUMO

STUDY QUESTION: Does activation of endometrial Toll-like receptor 3 (TLR 3) affect cell receptivity to trophoblast adhesion? SUMMARY ANSWER: TLR 3 activation in vitro reduces the attachment of trophoblast cells to endometrial cells by altering the cell cytoskeleton and reducing the expression of adhesion molecules in human endometrial cells. WHAT IS KNOWN ALREADY: It is well documented that the presence of an infection at the time of implantation can lead to implantation failure. The female reproductive tract recognizes invading micro-organisms through the innate pathogen recognition receptors such as the TLRs. STUDY DESIGN, SIZE, DURATION: Poly I:C was used as a TLR 3-specific ligand and endometrial cells were either treated or not with Poly I:C (treated versus control) in vitro. The experiments were performed in three replicates on three separate days. PARTICIPANTS/MATERIALS, SETTING, METHODS: An in vitro assay was developed using RL95-2 (a human endometrial cell line) and JAr (a human trophoblast cell line) cells. Initially, the percentage of attached JAr spheroids to RL95-2 was measured in response to TLR 3 activation. Next, actin polymerization in RL95-2 cells was assessed in response to TLR 2/6, 3 and 5 activation. Phalloidin was used to assess the mean fluorescence intensity of F-actin by flow cytometry or confocal microscopy. Secondly, the influence of TLR 2/6, 3 and 5 activation on the expression of cluster of differentiation 98 (CD98) and ß3 integrin was determined. To further understand through which pathways the TLR 3-induced alterations occur, inhibitors were applied for Toll/interleukin-1 receptor domain-containing adaptor inducing interferon-beta (TRIF), myeloid differentiation primary response 88 (MYD88), mitogen-activated protein kinases (MAPK) and nuclear factor pathways. MAIN RESULTS AND THE ROLE OF CHANCE: We observed that stimulation of TLR 3 in endometrial cells with different concentrations of Poly I:C led to a reduction in the percentage of trophoblasts attached to the endometrial cells in a dose-dependent manner (P < 0.05). This decrease was consistent in the Poly I:C treated group regardless of the co-incubation time (P < 0.05). In addition, our results demonstrated that actin polymerization and CD98 expression significantly decreased only in response to TLR 3 activation (P < 0.05). Activation of endometrial cells with TLR 2/6, 3 and 5 significantly reduced ß3 integrin expression (P < 0.05). These alterations were shown to work via MYD88-MAPK pathways (P < 0.05). LIMITATIONS, REASONS FOR CAUTION: This study has been performed in vitro. Future in vivo studies will be required in order to confirm our data. WIDER IMPLICATIONS OF THE FINDINGS: This is a novel discovery which extends our current knowledge concerning diagnosis and treatment of viral-induced infertility cases. STUDY FUNDING/COMPETING INTERESTS: This research was supported by the COST Action FA1201 (GEMINI) by granting a Short Term Scientific Mission and the Instituto de Salud Carlos III by granting Grant PI11/01645. The authors have no conflict of interest to declare.


Assuntos
Actinas/química , Moléculas de Adesão Celular/metabolismo , Implantação do Embrião/fisiologia , Endométrio/metabolismo , Receptor 3 Toll-Like/metabolismo , Trofoblastos/citologia , Viroses/complicações , Adesão Celular , Linhagem Celular , Sobrevivência Celular , Citoesqueleto/metabolismo , Feminino , Proteína-1 Reguladora de Fusão/metabolismo , Humanos , Integrina beta3/metabolismo , Ligantes , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Fator 88 de Diferenciação Mieloide/metabolismo , Poli I-C/metabolismo , Transdução de Sinais
11.
Phys Rev Lett ; 114(9): 095004, 2015 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-25793822

RESUMO

Energy loss in the transport of a beam of relativistic electrons in warm dense aluminum is measured in the regime of ultrahigh electron beam current density over 2×10^{11} A/cm^{2} (time averaged). The samples are heated by shock compression. Comparing to undriven cold solid targets, the roles of the different initial resistivity and of the transient resistivity (upon target heating during electron transport) are directly observable in the experimental data, and are reproduced by a comprehensive set of simulations describing the hydrodynamics of the shock compression and electron beam generation and transport. We measured a 19% increase in electron resistive energy loss in warm dense compared to cold solid samples of identical areal mass.

12.
Haemophilia ; 21(2): 162-170, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25623166

RESUMO

Acquired haemophilia A (AHA) is a rare bleeding disorder caused by autoantibodies against human factor VIII (hFVIII). OBI-1 is an investigational, B-domain deleted, recombinant FVIII, porcine sequence, with low cross-reactivity to anti-hFVIII antibodies. Efficacy can be monitored with FVIII activity levels in addition to clinical assessments. This prospective, open label, phase 2/3 study was designed to evaluate the efficacy of OBI-1 treatment for bleeding episodes in subjects with AHA. After an initial dose of 200 U kg(-1) , OBI-1 was titrated to maintain target FVIII activity levels, in correlation with clinical assessments, throughout the treatment phase. All 28 subjects with AHA had a positive response to OBI-1 treatment 24 h after initiation despite inhibition of FVIII activity levels immediately after infusion in 10 subjects with baseline anti-porcine FVIII inhibitors. Control of the qualifying bleed was ultimately achieved in 24 of 28 subjects. No related serious adverse events, thrombotic events, allergic reactions or thrombocytopaenia occurred. The results of this study indicate that OBI-1 is safe and effective in treating bleeding episodes in subjects with AHA. The ability to safely and effectively titrate dosing based on FVIII activity levels in this study demonstrates that OBI-1 fulfils the unmet medical need to monitor the key coagulation parameter in AHA patients.


Assuntos
Fator VIII/uso terapêutico , Hemofilia A/tratamento farmacológico , Proteínas Recombinantes/uso terapêutico , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Anticorpos Neutralizantes , Autoanticorpos/imunologia , Reações Cruzadas/imunologia , Fator VIII/administração & dosagem , Fator VIII/efeitos adversos , Fator VIII/imunologia , Feminino , Hemofilia A/imunologia , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/efeitos adversos , Proteínas Recombinantes/imunologia , Suínos , Fatores de Tempo , Resultado do Tratamento
13.
J Appl Microbiol ; 117(4): 1159-67, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24965702

RESUMO

AIMS: To characterize the nematicidal endophytic bacteria (NEB) of Wasabia japonica (wasabi) and evaluated the control efficacies of promising NEB as well as fresh wasabi residue (FWR) against Meloidogyne incognita on tomato. METHODS AND RESULTS: By in vitro bioassay, 53 NEB strains showing nematicidal efficacies of >50% against J2 of M. incognita were isolated from wasabi. Basing on 16S rRNA gene sequences, these NEB were identified into 18 species of 11 genera. In greenhouse, incorporation of selected NEB culture or FWR into potted soil significantly reduced infection of M. incognita on tomato. Treating tomatoes with either FWR or NEB of Raoultella terrigena RN16 and Pseudomonas reinekei SN21 in the field yielded excellent control efficacies against M. incognita, especially the combinations of FWR with either R. terrigena RN16 or Ps. reinekei SN21 at doses of 50 g plus 100 ml per plant or more. CONCLUSIONS: The results established that R. terrigena RN16 and Ps. reinekei SN21 applied separately or combined with FWR have the potential to provide bioprotection agents against M. incognita. SIGNIFICANCE AND IMPACT OF THE STUDY: This study provides novel way for disease management using combination of endophyte and host residue.


Assuntos
Bactérias/classificação , Bactérias/isolamento & purificação , Agentes de Controle Biológico , Solanum lycopersicum/parasitologia , Tylenchoidea , Wasabia/microbiologia , Animais , Enterobacteriaceae/isolamento & purificação , Doenças das Plantas/parasitologia , Doenças das Plantas/prevenção & controle , Raízes de Plantas/microbiologia , Pseudomonas/isolamento & purificação
14.
Science ; 374(6563): 92-95, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34591617

RESUMO

The radiolysis of water is ubiquitous in nature and plays a critical role in numerous biochemical and technological applications. Although the elementary reaction pathways for ionized water have been studied, the short-lived intermediate complex and structural dynamic response after the proton transfer reaction remain poorly understood. Using a liquid-phase ultrafast electron diffraction technique to measure the intermolecular oxygen···oxygen and oxygen···hydrogen bonds, we captured the short-lived radical-cation complex OH(H3O+) that was formed within 140 femtoseconds through a direct oxygen···oxygen bond contraction and proton transfer, followed by the radical-cation pair dissociation and the subsequent structural relaxation of water within 250 femtoseconds. These measurements provide direct evidence of capturing this metastable radical-cation complex before separation, thereby improving our fundamental understanding of elementary reaction dynamics in ionized liquid water.

15.
Nat Commun ; 12(1): 1638, 2021 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-33712576

RESUMO

Key insights in materials at extreme temperatures and pressures can be gained by accurate measurements that determine the electrical conductivity. Free-electron laser pulses can ionize and excite matter out of equilibrium on femtosecond time scales, modifying the electronic and ionic structures and enhancing electronic scattering properties. The transient evolution of the conductivity manifests the energy coupling from high temperature electrons to low temperature ions. Here we combine accelerator-based, high-brightness multi-cycle terahertz radiation with a single-shot electro-optic sampling technique to probe the evolution of DC electrical conductivity using terahertz transmission measurements on sub-picosecond time scales with a multi-undulator free electron laser. Our results allow the direct determination of the electron-electron and electron-ion scattering frequencies that are the major contributors of the electrical resistivity.

16.
Zhonghua Liu Xing Bing Xue Za Zhi ; 41(10): 1643-1648, 2020 Oct 10.
Artigo em Zh | MEDLINE | ID: mdl-33297620

RESUMO

Objectives: To understand the association between obesity and the risk for colorectal advanced adenoma. Methods: Community residents aged 45 to 74 who had participated in the Shanghai community-based colorectal cancer (CRC) screening project in 2008 were included in our study. Anthropometries information including body weight, height and risk factors for colorectal advanced adenoma were collected. Results on colonoscopic diagnosis and personal health records were used for supplementary outcome information retrieval. Multivariate Cox proportional hazard regression models were used to evaluate the hazard ratio (HR) and 95%CI of obesity on the risk for colorectal advanced adenoma. Results: 20 811 residents were followed up for 122 739.36 person-years, with a median follow-up time of 5.87 years. A total of 657 cases of advanced adenomas were identified. After adjusting for potential confounding risk factors such as age, sex, family history of CRC, level of education, marriage, cigarette smoking, alcohol drinking, foods intake including fat, fried or pickled, vegetables and fruits etc., the HR was 1.25 (95%CI: 1.04-1.51) for obese people when compared with the normal weight persons. Further stratified analysis by age, gender and family history of CRC, results showed that obese people had a much higher risk of colorectal advanced adenoma than those with normal weight (male: HR=1.57, 95%CI: 1.20-2.04; more than 60- year-old: HR=1.63, 95%CI: 1.23-2.16). Conclusion: Data from this large scale population-based study revealed that obesity might be an independent risk factor for colorectal advanced adenoma and the risk increases along with the increase of BMI in China.


Assuntos
Adenoma , Neoplasias Colorretais , Obesidade , Adenoma/epidemiologia , Adenoma/patologia , Idoso , China/epidemiologia , Neoplasias Colorretais/epidemiologia , Neoplasias Colorretais/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Obesidade/epidemiologia , Fatores de Risco
17.
Struct Dyn ; 7(2): 024301, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32161776

RESUMO

The conversion of light into usable chemical and mechanical energy is pivotal to several biological and chemical processes, many of which occur in solution. To understand the structure-function relationships mediating these processes, a technique with high spatial and temporal resolutions is required. Here, we report on the design and commissioning of a liquid-phase mega-electron-volt (MeV) ultrafast electron diffraction instrument for the study of structural dynamics in solution. Limitations posed by the shallow penetration depth of electrons and the resulting information loss due to multiple scattering and the technical challenge of delivering liquids to vacuum were overcome through the use of MeV electrons and a gas-accelerated thin liquid sheet jet. To demonstrate the capabilities of this instrument, the structure of water and its network were resolved up to the 3 rd hydration shell with a spatial resolution of 0.6 Å; preliminary time-resolved experiments demonstrated a temporal resolution of 200 fs.

18.
J Cell Biol ; 141(3): 791-804, 1998 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-9566977

RESUMO

Cell-to-cell junction structures play a key role in cell growth rate control and cell polarization. In endothelial cells (EC), these structures are also involved in regulation of vascular permeability and leukocyte extravasation. To identify novel components in EC intercellular junctions, mAbs against these cells were produced and selected using a morphological screening by immunofluorescence microscopy. Two novel mAbs, LIA1/1 and VJ1/16, specifically recognized a 25-kD protein that was selectively localized at cell-cell junctions of EC, both in the primary formation of cell monolayers and when EC reorganized in the process of wound healing. This antigen corresponded to the recently cloned platelet-endothelial tetraspan antigen CD151/PETA-3 (platelet-endothelial tetraspan antigen-3), and was consistently detected at EC cell-cell contact sites. In addition to CD151/PETA-3, two other members of the tetraspan superfamily, CD9 and CD81/ TAPA-1 (target of antiproliferative antibody-1), localized at endothelial cell-to-cell junctions. Biochemical analysis demonstrated molecular associations among tetraspan molecules themselves and those of CD151/ PETA-3 and CD9 with alpha3 beta1 integrin. Interestingly, mAbs directed to both CD151/PETA-3 and CD81/ TAPA-1 as well as mAb specific for alpha3 integrin, were able to inhibit the migration of ECs in the process of wound healing. The engagement of CD151/PETA-3 and CD81/TAPA-1 inhibited the movement of individual ECs, as determined by quantitative time-lapse video microscopy studies. Furthermore, mAbs against the CD151/PETA-3 molecule diminished the rate of EC invasion into collagen gels. In addition, these mAbs were able to increase the adhesion of EC to extracellular matrix proteins. Together these results indicate that CD81/TAPA-1 and CD151/PETA-3 tetraspan molecules are components of the endothelial lateral junctions implicated in the regulation of cell motility, either directly or by modulation of the function of the associated integrin heterodimers.


Assuntos
Antígenos CD/fisiologia , Movimento Celular/fisiologia , Endotélio Vascular/citologia , Endotélio Vascular/metabolismo , Integrinas/fisiologia , Junções Intercelulares/fisiologia , Glicoproteínas de Membrana , Proteínas de Membrana , Animais , Anticorpos Monoclonais/metabolismo , Antígenos CD/metabolismo , Linhagem Celular , Células Cultivadas , Colágeno , Matriz Extracelular , Géis , Humanos , Integrina alfa3beta1 , Camundongos , Camundongos Endogâmicos BALB C , Tetraspanina 24 , Tetraspanina 28 , Tetraspanina 29
19.
Zhonghua Liu Xing Bing Xue Za Zhi ; 40(4): 471-474, 2019 Apr 10.
Artigo em Zh | MEDLINE | ID: mdl-31006211

RESUMO

Objective: To investigate the dose-response relationship between hemoglobin concentration and preterm birth, during pregnancy. Methods: With Zhuang ethnicity, a total of 12 780 pregnant women and their infants that admitted to Wuming、Pingguo、Jingxi、Debao、Longan and Tiandong hospitals, were recruited, in Guangxi Zhuang Autonomous Region, from January 2015 to December 2017. Non-conditional logistic regression method was used to analyze the effect of anemia on preterm birth during pregnancy. Dose-response relationship between hemoglobin concentration and preterm birth was explored, using the restrictive cubic spline model. Results: After excluding 2 053 pregnant women with hypertension or aged 35 years and over, results from the non-conditional logistic regression analysis showed that the risk of preterm birth in the anemia group was 1.29 times (OR=1.29, 95%CI: 1.04-1.59, P=0.019) of the non-anemia group in the first trimester. Data from the restricted cubic sample showed that there appeared nonlinear "L" dose-response relationship between hemoglobin concentration and preterm birth in the first trimester and "U" shape in the third trimester (non-linearity test P<0.001). Conclusion: There appeared nonlinear dose-response relationship between the hemoglobin concentration and preterm birth, both in the first and third trimesters.


Assuntos
Anemia/complicações , Retardo do Crescimento Fetal/epidemiologia , Hemoglobinas/metabolismo , Trabalho de Parto Prematuro/epidemiologia , Nascimento Prematuro/epidemiologia , Adulto , China/epidemiologia , Feminino , Retardo do Crescimento Fetal/etiologia , Humanos , Recém-Nascido , Trabalho de Parto Prematuro/etiologia , Gravidez , Complicações Hematológicas na Gravidez , Resultado da Gravidez , Gestantes , Fatores de Risco
20.
Rev Sci Instrum ; 89(10): 10C108, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30399817

RESUMO

Electron-lattice coupling strength governs the energy transfer between electrons and the lattice and is important for understanding the material behavior under highly non-equilibrium conditions. Here we report the results of employing time-resolved electron diffraction at MeV energies to directly study the electron-lattice coupling strength in 40-nm-thick polycrystalline copper excited by femtosecond optical lasers. The temporal evolution of lattice temperature at various pump fluence conditions were obtained from the measurements of the Debye-Waller decay of multiple diffraction peaks. We observed the temperature dependence of the electron-lattice relaxation time which is a result of the temperature dependence of electron heat capacity. Comparison with two-temperature model simulations reveals an electron-lattice coupling strength of (0.9 ± 0.1) × 1017 W/m3/K for copper.

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