Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 49
Filtrar
1.
Proc Natl Acad Sci U S A ; 119(4)2022 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-35064079

RESUMO

We present a surface-engineering approach that turns all liquids highly wetting, including ultra-high surface tension fluids such as mercury. Previously, highly wetting behavior was only possible for intrinsically wetting liquid/material combinations through surface roughening to enable the so-called Wenzel and hemiwicking states, in which liquid fills the surface structures and causes a droplet to exhibit a low contact angle when contacting the surface. Here, we show that roughness made of reentrant structures allows for a metastable hemiwicking state even for nonwetting liquids. Our surface energy model reveals that with liquid filled in the structure, the reentrant feature creates a local energy barrier, which prevents liquid depletion from surface structures regardless of the intrinsic wettability. We experimentally demonstrated this concept with microfabricated reentrant channels. Notably, we show an apparent contact angle as low as 35° for mercury on structured silicon surfaces with fluorinated coatings, on which the intrinsic contact angle of mercury is 143°, turning a highly nonwetting liquid/material combination highly wetting through surface engineering. Our work enables highly wetting behavior for previously inaccessible material/liquid combinations and thus expands the design space for various thermofluidic applications.

2.
Nano Lett ; 23(14): 6414-6423, 2023 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-37399449

RESUMO

Graphene oxide (GO) is a promising membrane material for chemical separations, including water treatment. However, GO has often required postsynthesis chemical modifications, such as linkers or intercalants, to improve either the permeability, performance, or mechanical integrity of GO membranes. In this work, we explore two different feedstocks of GO to investigate chemical and physical differences, where we observe up to a 100× discrepancy in the permeability-mass loading trade-off while maintaining nanofiltration capacity. GO membranes also show structural stability and chemical resilience to harsh pH conditions and bleach treatment. We probe GO and the resulting assembled membranes through a variety of characterization approaches, including a novel scanning-transmission-electron-microscopy-based visualization approach, to connect differences in sheet stacking and oxide functional groups to significant improvements in permeability and chemical stability.

3.
Mol Biol Rep ; 50(8): 6643-6654, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37358763

RESUMO

BACKGROUND: Sepsis is a life-threatening disease with a limited effectiveness and the potential mechanism remains unclear. LncRNA NEAT-2 is reported to be involved in the regulation of cardiovascular disease. This study aimed to investigate the function of NEAT-2 in sepsis. METHODS: We built sepsis animal model with Male Balb/C mice induced by cecal ligation and puncture (CLP). A total of 54 mice were randomly assigned into eight groups: sham operation group (n = 18), CLP group (n = 18), CLP plus si-control group (n = 3), CLP plus si-NEAT2 group (n = 3), CLP plus mimic control group (n = 3), CLP plus miR-320 group (n = 3), CLP plus normal saline group (n = 3), and normal control group (n = 3). The number of peripheral endothelial progenitor cells (EPCs), the expression level of NEAT-2 and miR-320 were detected during progression of sepsis, as well as the number of peripheral EPCs and level of TNF-α, IL-6, VEGF, ALT, AST and Cr. In addition, the function of EPCs was evaluated after NEAT-2 knockdown and miR-320 overexpression in vitro. RESULTS: The number of circulating EPCs increased significantly in sepsis. NEAT-2 expression was significantly increased in the progress of sepsis, accompanied with miR-320 downregulated. NEAT-2 knockdown and miR-320 overexpression attenuated hepatorenal function and increased cytokines in sepsis. Moreover, NEAT-2 knockdown and miR-320 overexpression decreased the proliferation, migration and angiogenesis of endothelial progenitor cells in vitro. CONCLUSIONS: LncRNA-NEAT2 regulated the number and function of endothelial progenitor cells via miR-320 in sepsis, which may contribute to the development of novel potential clinical therapy for sepsis.


Assuntos
Células Progenitoras Endoteliais , MicroRNAs , RNA Longo não Codificante , Sepse , Camundongos , Masculino , Animais , RNA Longo não Codificante/genética , Fígado/metabolismo , Sepse/genética , Sepse/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Modelos Animais de Doenças
4.
World J Surg Oncol ; 21(1): 245, 2023 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-37563693

RESUMO

PURPOSE: Currently, the characteristics and prognosis of remnant gastric cancer (RGC) are not fully understood yet. The present study aimed to describe the details of clinicopathological features of resectable RGC and investigated the factors affecting survival after the curative operation. METHODS: From Jan. 2006 to Dec. 2015, a total of 118 resectable RGC patients (the RGC group) and 236 age-, sex- and TNM stages-matched resectable gastric cancer (GC) patients (the control group) were recruited retrospectively. Clinicopathological characteristics and overall survival were compared between the two groups. RESULTS: The overall survival rate was 46.61% for RGC patients compared to 55.08% for control groups (P < 0.01), and the mean overall survival time of RGC patients was 40.23 ± 32.27 months, compared to 55.06 ± 34.29 months in the control group (P = 0.023 after matching). The overall survival (OS) of RGC patients with stage IIb was much worse than IIa (P < 0.001) and similar to IIIa (P = 0.463) and IIIb (P = 0.014). Multivariate Cox proportional hazards model analysis revealed that TNM stage (HR: 3.899, P < 0.001) and lymph nodes ratio (LNR) (HR: 2.405, P = 0.028) were independent prognostic significance to OS. CONCLUSIONS: The OS of RGC was much worse than GC with similar TNM stages, and LNR might consider a highly reliable indicator to evaluate the prognostic in RGC.


Assuntos
Gastrectomia , Neoplasias Gástricas , Humanos , Estudos Retrospectivos , Estadiamento de Neoplasias , Neoplasias Gástricas/patologia , Pontuação de Propensão , Prognóstico , Linfonodos/cirurgia , Linfonodos/patologia
5.
Nano Lett ; 22(3): 1100-1107, 2022 02 09.
Artigo em Inglês | MEDLINE | ID: mdl-35061401

RESUMO

Hygroscopic hydrogels hold significant promise for high-performance atmospheric water harvesting, passive cooling, and thermal management. However, a mechanistic understanding of the sorption kinetics of hygroscopic hydrogels remains elusive, impeding an optimized design and broad adoption. Here, we develop a generalized two-concentration model (TCM) to describe the sorption kinetics of hygroscopic hydrogels, where vapor transport in hydrogel micropores and liquid transport in polymer nanopores are coupled through the sorption at the interface. We show that the liquid transport due to the chemical potential gradient in the hydrogel plays an important role in the fast kinetics. The high water uptake is attributed to the expansion of hydrogel during liquid transport. Moreover, we identify key design parameters governing the kinetics, including the initial porosity, hydrogel thickness, and shear modulus. This work provides a generic framework of sorption kinetics, which bridges the knowledge gap between the fundamental transport and practical design of hygroscopic hydrogels.


Assuntos
Hidrogéis , Água , Gases , Cinética , Polímeros
6.
Langmuir ; 38(14): 4371-4377, 2022 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-35349299

RESUMO

Bubble evolution plays a fundamental role in boiling and gas-evolving electrochemical systems. One key stage is bubble departure, which is traditionally considered to be buoyancy-driven. However, conventional understanding cannot provide the full physical picture, especially for departure events with small bubble sizes commonly observed in water splitting and high heat flux boiling experiments. Here, we report a new regime of bubble departure owing to the coalescence of two bubbles, where the departure diameter can be much smaller than the conventional buoyancy limit. We show the significant reduction of the bubble base area due to the dynamics of the three-phase contact line during coalescence, which promotes bubble departure. More importantly, combining buoyancy-driven and coalescence-induced bubble departure modes, we demonstrate a unified relationship between the departure diameter and nucleation site density. By elucidating how coalescing bubbles depart from a wall, our work provides design guidelines for energy systems which can largely benefit from efficient bubble departure.

7.
Langmuir ; 36(49): 15112-15118, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-33259214

RESUMO

Bubble nucleation is ubiquitous in gas evolving reactions that are instrumental for a variety of electrochemical systems. Fundamental understanding of the nucleation process, which is critical to system optimization, remains limited as prior works generally focused on the thermodynamics and have not considered the coupling between surface geometries and different forms of transport in the electrolytes. Here, we establish a comprehensive transport-based model framework to identify the underlying mechanism for bubble nucleation on gas evolving electrodes. We account for the complex effects on the electrical field, ion migration, ion diffusion, and gas diffusion arising from surface heterogeneities and gas pockets initiated from surface crevices. As a result, we show that neglecting these effects leads to significant underprediction of the energy needed for nucleation. Our model provides a non-monotonic relationship between the surface cavity size and the overpotential required for nucleation, which is physically more consistent than the monotonic relationship suggested by a traditional thermodynamics-based model. We also identify the significance of the gas diffuse layer thickness, a parameter controlled by external flow fields and overall electrode geometries, which has been largely overlooked in previous models. Our model framework offers guidelines for practical electrochemical systems whereby, without changing the surface chemistry, nucleation on electrodes can be tuned by engineering the cavity size and the gas diffuse layer thickness.

8.
Cell Biochem Funct ; 38(1): 4-11, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31733068

RESUMO

The roles of cancer-associated fibroblasts (CAFs) in progression of gastric cancer (GC) are far from well illustration. Here, we show that CAFs can trigger the proliferation and decrease the doxorubicin (Dox) sensitivity of GC cells via secretion of Nodal, one embryonic morphogen that can promote malignancy of various cancers. The neutralization antibody of Nodal can attenuate CAFs-induced cell proliferation. Further, CAFs can activate the Smad2/3 signal, which further increase the phosphorylation and nuclear localization of Akt, in GC cells. While anti-Nodal can abolish the CAFs-induced activation of Smad2/3/Akt signals. Further, both inhibitors of Smad2/3 and Akt can attenuate CAFs-induced proliferation of GC cells. All these data suggest that CAFs can increase the malignancy of GC cells via Nodal-induced activation of Smad2/3/Akt signals. It indicates that CAFs/Nodal signals might be a potential new target of clinical interventions for GC patients. SIGNIFICANCE OF THE STUDY: The roles about CAFs in progression of GC are not well illustrated. Our present study reveals that CAFs can increase the proliferation and decrease the Dox sensitivity of GC cells via secretion of Nodal. The secreted Nodal further activated Samd2/3/Akt signals to trigger the GC progression. It suggests that targeted inhibition CAFs/Nodal might be a potential approach for GC therapy.


Assuntos
Fibroblastos Associados a Câncer/metabolismo , Proteína Nodal/metabolismo , Transdução de Sinais , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patologia , Antibióticos Antineoplásicos/farmacologia , Fibroblastos Associados a Câncer/efeitos dos fármacos , Fibroblastos Associados a Câncer/patologia , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Doxorrubicina/farmacologia , Humanos , Proteína Nodal/antagonistas & inibidores , Proteína Nodal/genética , Transdução de Sinais/efeitos dos fármacos , Neoplasias Gástricas/tratamento farmacológico , Relação Estrutura-Atividade , Células Tumorais Cultivadas
9.
World J Surg Oncol ; 18(1): 302, 2020 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-33213468

RESUMO

BACKGROUND: Analysis of the risk factors associated with functional delayed gastric emptying after distal gastric cancer surgery to provide a basis for further reduction of the incidence of this complication. METHODS: Total of 1382 patients with distal gastric cancer from January 2016 to October 2018 were enrolled. Correlation analysis was performed in 53 patients with FDGE by logistic regression. Subgroup risk analysis was performed in 114 patients with preoperative pyloric obstruction. A Pearson Chi-square analysis was used to compare categorical variables between normal distribution groups. Meanwhile, a t test was used to compare continuous variables between groups. Odds ratio (OR) was used for comparison of the two groups, and it was summarized with its 95% confidence interval (CI) and p value using logistic regression. RESULT: In multivariable analysis, age (OR 1.081, 95% CI, 1.047-1.117), BMI (OR 1.233, 95% CI, 1.116-1.363), preoperative pyloric obstruction (OR 3.831, 95% CI, 1.829-8.023), smaller volume of residual stomach (OR 1.838, 95% CI, 1.325-6.080), and anastomosis in greater curvature perpendicular (OR 3.385, 95% CI, 1.632-7.019) and in greater curvature parallel (OR 2.375, 95% CI, 0.963-5.861) were independent risk factors of FDGE. In the preoperative pyloric obstruction group, higher BMI (OR 1.309, 95% CI, 1.086-1.579) and preoperative obstruction time (OR 1.054, 95% CI, 1.003-1.108) were independent risk factors of FDGE and preoperative gastrointestinal decompression (OR 0.231, 95% CI, 0.068-0.785) was independent protective factor of FDGE. CONCLUSION: Adequate gastrointestinal decompression should be performed before the operation to reduce the incidence of postoperative gastroparesis in patients with preoperative pyloric obstruction. We also could improve the surgical methods to reduce the occurrence of FDGE, such as controlling the size of the residual stomach, ensuring blood supply. Especially selecting an appropriate stapler and anastomosis during the anastomosis process, the occurrence of FDGE can be reduced.


Assuntos
Gastroparesia , Neoplasias Gástricas , Humanos , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/prevenção & controle , Prognóstico , Estudos Retrospectivos , Fatores de Risco , Neoplasias Gástricas/cirurgia
10.
World J Surg Oncol ; 18(1): 2, 2020 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-31898548

RESUMO

BACKGROUND: The status of lymph nodes in early gastric cancer is critical to make further clinical treatment decision, but the prediction of lymph node metastasis remains difficult before operation. This study aimed to develop a nomogram that contained preoperative factors to predict lymph node metastasis in early gastric cancer patients. METHODS: This study analyzed the clinicopathologic features of 823 early gastric cancer patients who underwent gastrectomy retrospectively, among which 596 patients were recruited in the training cohort and 227 patients in the independent validation cohort. Significant risk factors in univariate analysis were further identified to be independent variables in multivariable logistic regression analysis, which were then incorporated in and presented with a nomogram. And internal and external validation curves were plotted to evaluate the discrimination of the nomogram. RESULTS: Totally, six independent predictors, including the tumor size, macroscopic features, histology differentiation, P53, carbohydrate antigen 19-9, and computed tomography-reported lymph node status, were enrolled in the nomogram. Both the internal validation in the training cohort and the external validation in the validation cohort showed the nomogram had good discriminations, with a C-index of 0.82 (95%CI, 0.78 to 0.86) and 0.77 (95%CI, 0.60 to 0.94) respectively. CONCLUSIONS: Our study developed a new nomogram which contained the most common and significant preoperative risk factors for lymph node metastasis in patients with early gastric cancer. The nomogram can identify early gastric cancer patients with the high probability of lymph node metastasis and help clinicians make more appropriate decisions in clinical practice.


Assuntos
Linfonodos/patologia , Nomogramas , Neoplasias Gástricas/patologia , Antígeno CA-19-9/metabolismo , Detecção Precoce de Câncer , Feminino , Seguimentos , Gastrectomia/métodos , Gastroscopia/métodos , Humanos , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Cuidados Pré-Operatórios/métodos , Prognóstico , Curva ROC , Estudos Retrospectivos , Neoplasias Gástricas/diagnóstico por imagem , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/cirurgia , Tomografia Computadorizada por Raios X
11.
Nano Lett ; 19(7): 4745-4751, 2019 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-31184905

RESUMO

Atomically thin two-dimensional (2D) materials have shown great potential for applications in nanoscale electronic and optical devices. A fundamental property of these 2D flakes that needs to be well-characterized is the thermal expansion coefficient (TEC), which is instrumental to the dry transfer process and thermal management of 2D material-based devices. However, most of the current studies of 2D materials' TEC extensively rely on simulations due to the difficulty of performing experimental measurements on an atomically thin, micron-sized, and optically transparent 2D flake. In this work, we present a three-substrate approach to characterize the TEC of monolayer molybdenum disulfide (MoS2) using micro-Raman spectroscopy. The temperature dependence of the Raman peak shift was characterized with three different substrate conditions, from which the in-plane TEC of monolayer MoS2 was extracted on the basis of lattice symmetries. Independently from two different phonon modes of MoS2, we measured the in-plane TECs as (7.6 ± 0.9) × 10-6 K-1 and (7.4 ± 0.5) × 10-6 K-1, respectively, which are in good agreement with previously reported values based on first-principle calculations. Our work is not only useful for thermal mismatch reduction during material transfer or device operation but also provides a general experimental method that does not rely on simulations to study key properties of 2D materials.

12.
J Transl Med ; 17(1): 189, 2019 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-31164161

RESUMO

BACKGROUND: Gastric cancer (GC) is a leading cause of cancer deaths, and an increased number of GC patients adopt to next-generation sequencing (NGS) to identify tumor genomic alterations for precision medicine. METHODS: In this study, we established a hybridization capture-based NGS panel including 612 cancer-associated genes, and collected sequencing data of tumors and matched bloods from 153 gastric cancer patients. We performed comprehensive analysis of these sequencing and clinical data. RESULTS: 35 significantly mutated genes were identified such as TP53, AKAP9, DRD2, PTEN, CDH1, LRP2 et al. Among them, 29 genes were novel significantly mutated genes compared with TCGA study. TP53 is the top frequently mutated gene, and tends to mutate in male (p = 0.025) patients and patients whose tumor located in cardia (p = 0.011). High tumor mutation burden (TMB) gathered in TP53 wild-type tumors (p = 0.045). TMB was also significantly associated with DNA damage repair (DDR) genes genotype (p = 0.047), Lauren classification (p = 1.5e-5), differentiation (1.9e-7), and HER2 status (p = 0.023). 38.31% of gastric cancer patients harbored at least one actionable alteration according to OncoKB database. CONCLUSIONS: We drew a comprehensive mutational landscape of 153 gastric tumors and demonstrated utility of target next-generation sequencing to guide clinical management.


Assuntos
Biomarcadores Tumorais/genética , Análise Mutacional de DNA/métodos , Perfilação da Expressão Gênica/métodos , Genômica/métodos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Neoplasias Gástricas/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Estadiamento de Neoplasias , Medicina de Precisão , Análise de Sequência de DNA/métodos , Neoplasias Gástricas/diagnóstico , Neoplasias Gástricas/patologia , Neoplasias Gástricas/terapia , Adulto Jovem
13.
Mediators Inflamm ; 2019: 8297391, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31148948

RESUMO

Multiple organ dysfunction syndrome (MODS) remains a great challenge in critical care because of its common occurrence, high cost of care, and high mortality. Vascular endothelial injury is the initiation step in the development of MODS, and EPCs are essential for the process of organ repair. It is unclear whether and how caveolin-1 (Cav-1) in EPCs contributes to the pathogenesis of MODS. The present study is aimed at investigating the potential role of Cav-1 in EPCs during MODS. We established a MODS model in pigs, isolated and characterized EPCs from the MODS model, and tracked Cav-1 expression and various in vitro behaviors of EPCs from the MODS model. Then, we knockdown Cav-1 expression with siRNA or induce Cav-1 expression with proinflammatory factors to evaluate potential effects on EPCs. Our results suggest that Cav-1 expression correlated with EPC functions during MODS and Cav-1 regulates the function of endothelial progenitor cells via PI3K/Akt/eNOS signaling during MODS. Thus, Cav-1 in EPCs could be an attractive target for the treatment of MODS.


Assuntos
Caveolina 1/metabolismo , Células Progenitoras Endoteliais/metabolismo , Animais , Caveolina 1/genética , Masculino , Insuficiência de Múltiplos Órgãos/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/genética , Transdução de Sinais/fisiologia , Suínos
14.
Langmuir ; 34(15): 4658-4664, 2018 04 17.
Artigo em Inglês | MEDLINE | ID: mdl-29578348

RESUMO

Vapor condensation is routinely used as an effective means of transferring heat or separating fluids. Filmwise condensation is prevalent in typical industrial-scale systems, where the condensed fluid forms a thin liquid film due to the high surface energy associated with many industrial materials. Conversely, dropwise condensation, where the condensate forms discrete liquid droplets which grow, coalesce, and shed, results in an improvement in heat transfer performance of an order of magnitude compared to filmwise condensation. However, current state-of-the-art dropwise technology relies on functional hydrophobic coatings, for example, long chain fatty acids or polymers, which are often not robust and therefore undesirable in industrial conditions. In addition, low surface tension fluid condensates, such as hydrocarbons, pose a unique challenge because common hydrophobic condenser coatings used to shed water (with a surface tension of 73 mN/m) often do not repel fluids with lower surface tensions (<25 mN/m). We demonstrate a method to enhance condensation heat transfer using gravitationally driven flow through a porous metal wick, which takes advantage of the condensate's affinity to wet the surface and also eliminates the need for condensate-phobic coatings. The condensate-filled wick has a lower thermal resistance than the fluid film observed during filmwise condensation, resulting in an improved heat transfer coefficient of up to an order of magnitude and comparable to that observed during dropwise condensation. The improved heat transfer realized by this design presents the opportunity for significant energy savings in natural gas processing, thermal management, heating and cooling, and power generation.

15.
Nano Lett ; 17(10): 6217-6220, 2017 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-28926270

RESUMO

Evaporation is a ubiquitous phenomenon found in nature and widely used in industry. Yet a fundamental understanding of interfacial transport during evaporation remains limited to date owing to the difficulty of characterizing the heat and mass transfer at the interface, especially at high heat fluxes (>100 W/cm2). In this work, we elucidated evaporation into an air ambient with an ultrathin (≈200 nm thick) nanoporous (≈130 nm pore diameter) membrane. With our evaporator design, we accurately monitored the temperature of the liquid-vapor interface, reduced the thermal-fluidic transport resistance, and mitigated the clogging risk associated with contamination. At a steady state, we demonstrated heat fluxes of ≈500 W/cm2 across the interface over a total evaporation area of 0.20 mm2. In the high flux regime, we showed the importance of convective transport caused by evaporation itself and that Fick's first law of diffusion no longer applies. This work improves our fundamental understanding of evaporation and paves the way for high flux phase-change devices.

16.
Langmuir ; 33(36): 8970-8975, 2017 09 12.
Artigo em Inglês | MEDLINE | ID: mdl-28816460

RESUMO

Textured surfaces are instrumental in water repellency or fluid wicking applications, where the pinning and depinning of the liquid-gas interface plays an important role. Previous work showed that a contact line can exhibit nonuniform behavior due to heterogeneities in surface chemistry or roughness. We demonstrate that such nonuniformities can be achieved even without varying the local energy barrier. Around a cylindrical pillar, an interface can reside in an intermediate state where segments of the contact line are pinned to the pillar top while the rest of the contact line moves along the sidewall. This partially pinned mode is due to the global nonaxisymmetric pattern of the surface features and exists for all textured surfaces, especially when superhydrophobic surfaces are about to be flooded or when capillary wicks are close to dryout.

17.
Langmuir ; 32(7): 1920-7, 2016 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-26808963

RESUMO

Thin-film evaporation in wick structures for cooling high-performance electronic devices is attractive because it harnesses the latent heat of vaporization and does not require external pumping. However, optimizing the wick structures to increase the dry-out heat flux is challenging due to the complexities in modeling the liquid-vapor interface and the flow through the wick structures. In this work, we developed a model for thin-film evaporation from micropillar array wick structures and validated the model with experiments. The model numerically simulates liquid velocity, pressure, and meniscus curvature along the wicking direction by conservation of mass, momentum, and energy based on a finite volume approach. Specifically, the three-dimensional meniscus shape, which varies along the wicking direction with the local liquid pressure, is accurately captured by a force balance using the Young-Laplace equation. The dry-out condition is determined when the minimum contact angle on the pillar surface reaches the receding contact angle as the applied heat flux increases. With this model, we predict the dry-out heat flux on various micropillar structure geometries (diameter, pitch, and height) in the length scale range of 1-100 µm and discuss the optimal geometries to maximize the dry-out heat flux. We also performed detailed experiments to validate the model predictions, which show good agreement. This work provides insights into the role of surface structures in thin-film evaporation and offers important design guidelines for enhanced thermal management of high-performance electronic devices.

18.
Langmuir ; 31(36): 9817-24, 2015 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-26322737

RESUMO

Evaporation from nanopores is of fundamental interest in nature and various industrial applications. We present a theoretical framework to elucidate evaporation and transport within nanopores by incorporating nonequilibrium effects due to the deviation from classical kinetic theory. Additionally, we include the nonlocal effects arising from phase change in nanoporous geometries and the self-regulation of the shape and position of the liquid-vapor interface in response to different operating conditions. We then study the effects of different working parameters to determine conditions suitable for maximizing evaporation from nanopores.


Assuntos
Modelos Teóricos , Nanoporos
19.
Tumour Biol ; 35(4): 2941-8, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24318989

RESUMO

Polymorphisms in the excision repair cross-complimentary group 1 (ERCC1)-excision repair cross-complimentary group 4 (ERCC4) genes have been implicated in the prognosis of various cancers. We conducted a cohort study to investigate the role of ERCC1-ERCC4 gene polymorphisms on the response to chemotherapy and the role of these two gene polymorphisms on the clinical outcomes of gastric cancer. Four hundred forty-seven patients with newly diagnosed and histopathologically confirmed primary gastric cancer were collected in our study and were followed up until March 2012. ERCC1 (rs11615, rs3212986C>A, and rs2298881) and ERCC4 (rs226466C>G, rs2276465, and rs6498486) were selected and genotyped. The overall chemotherapy response rate for treatment was 68 %. Carriers of the rs11615 TT and T allele and ERCC1 rs2298881 CC and C allele had a marginally significantly higher response rate to the chemotherapy. In the Cox proportional hazard model, the hazard ratios (HRs) for overall survival (OS) in patients carrying ERCC1 rs11615 TT genotype and T allele were 0.53 (0.29-0.95) and 0.63 (0.42-0.94), respectively. Similarly, we found a significant decreased risk of death from gastric cancer among patients carrying ERCC1 rs2298881 CC genotype and C allele when compared with CC genotype, and HRs (95% confidence interval (CI)) of OS were 0.50 (0.24-0.98) and 0.62 (0.40-0.96), respectively. Moreover, individuals carrying ERCC1 rs11615 T allele and rs2298881 C allele could decrease a 0.62-fold risk of death from gastric cancer. This study reported a carriage of ERCC1 rs11615, and rs2298881 polymorphism can be used as a predictor of response to folinic acid/5-fluorouracil (5-FU)/oxaliplatin (FOLFOX)-based chemotherapy in gastric cancer patients.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Proteínas de Ligação a DNA/genética , Endonucleases/genética , Polimorfismo de Nucleotídeo Único , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/genética , Adulto , Idoso , Reparo do DNA , Feminino , Fluoruracila/uso terapêutico , Genótipo , Humanos , Leucovorina/uso terapêutico , Masculino , Pessoa de Meia-Idade , Compostos Organoplatínicos/uso terapêutico , Prognóstico , Modelos de Riscos Proporcionais , Neoplasias Gástricas/mortalidade
20.
BMC Complement Altern Med ; 14: 74, 2014 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-24565373

RESUMO

BACKGROUND: It has been suggested that the formation of osteoblasts in bone marrow is closely associated with adipogenesis, and the balance between osteogenesis and adipogenesis differentiation of MSCs (mesenchymal stem cells) is disrupted in osteoporosis. In order to improve the treatment of osteoporosis, available agents with roles of regulating the balance is highly desirable. Emodin is a natural anthraquinone derivative extracted from Chinese herbs, which have been used to treat bone diseases for thousands of years. However, the underlying molecular mechanisms of emodin in modulating osteogenesis and adipogenesis remain poorly understood. METHODS: The molecular mechanisms of emodin on the processes of osteogenesis and adipogenesis in ovariectomized mouse and BMSCs (bone marrow mesenchymal stem cells) have been studied. We have analyzed the effects of emodin in vivo and in vitro. Female ICR mice were assigned to three groups: sham group, ovariectomy group, emodin group. Efficacy was evaluated by H&E, immunohistochemical assay and Micro-CT. In vitro, we analyze the effect of emodin--at concentrations between 0.1 µM and 10 µM--on the processes of inducing osteogenesis and inhibiting adipogenesis in BMSCs by ALP, Oil red O staining, real time RT-PCR and western blot. RESULTS: As our experiment shows that emodin could increase the number of osteoblast, BMD (bone mineral density), BV/TV (trabecular bone volume fraction), Tb.N (trabecular number) and Conn.D (connectivity density) of OVX (ovariectomized) mice and decrease the bone marrow fat tissue and adipocytes. The genes and proteins expression of osteogenesis markers, such as Runx2, osterix, collagen type I, osteocalcin, or ALP were up-regulated. While, the genes and proteins involved in adipogenesis, PPARγ, C/EBPα and ap2 were down-regulated. CONCLUSION: It proves that emodin inhibits adipocyte differentiation and enhances osteoblast differentiation from BMSCs.


Assuntos
Adipogenia/efeitos dos fármacos , Tecido Adiposo/efeitos dos fármacos , Osso e Ossos/efeitos dos fármacos , Emodina/farmacologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Osteogênese/efeitos dos fármacos , Osteoporose/prevenção & controle , Tecido Adiposo/metabolismo , Animais , Densidade Óssea/efeitos dos fármacos , Medula Óssea/efeitos dos fármacos , Osso e Ossos/metabolismo , Proteínas Estimuladoras de Ligação a CCAAT/metabolismo , Medicamentos de Ervas Chinesas/farmacologia , Medicamentos de Ervas Chinesas/uso terapêutico , Emodina/uso terapêutico , Proteínas de Ligação a Ácido Graxo/metabolismo , Feminino , Humanos , Camundongos Endogâmicos ICR , Osteoblastos/efeitos dos fármacos , Osteoporose/metabolismo , Ovariectomia , PPAR gama/metabolismo , Fitoterapia , Polygonum/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA