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1.
J Integr Plant Biol ; 2020 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-32275096

RESUMO

Plants have evolved sophisticated defense mechanisms to overcome their sessile nature. However, if and how volatiles from cold-stressed plants can trigger interplant communication is still unknown. Here, we provide the first evidence for interplant communication via inducible volatiles in cold stress. The volatiles, including nerolidol, geraniol, linalool, and methyl salicylate, emitted from cold-stressed tea plants play key role(s) in priming cold tolerance of their neighbors via a C-repeat-binding factors-dependent pathway. The knowledge will help us to understand how plants respond to volatile cues in cold stress and agricultural ecosystems.

2.
Int J Mol Sci ; 21(2)2020 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-31963919

RESUMO

Terpenoids play vital roles in tea aroma quality and plants defense performance determination, whereas the scenarios of genes to metabolites of terpenes pathway remain uninvestigated in tea plants. Here, we report the use of an integrated approach combining metabolites, target gene transcripts and function analyses to reveal a gene-to-terpene network in tea plants. Forty-one terpenes including 26 monoterpenes, 14 sesquiterpenes and one triterpene were detected and 82 terpenes related genes were identified from five tissues of tea plants. Pearson correlation analysis resulted in genes to metabolites network. One terpene synthases whose expression positively correlated with farnesene were selected and its function was confirmed involved in the biosynthesis of α-farnesene, ß-ocimene and ß-farnesene, a very important and conserved alarm pheromone in response to aphids by both in vitro enzymatic assay in planta function analysis. In summary, we provided the first reliable gene-to-terpene network for novel genes discovery.

3.
J Agric Food Chem ; 68(6): 1684-1690, 2020 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-31957431

RESUMO

The carotenoid-derived volatile ß-ionone plays an important role in the formation of green and black tea flavors due to its low odor threshold, but its formation and the gene(s) involved in its biosynthesis during the tea withering process is(are) still unknown. In this study, we found that the content of ß-ionone increased during the tea withering process catalyzed by an unknown enzyme(s). Correlation analysis of expression patterns of Camellia sinensis carotenoid cleavage dioxygenase genes (CsCCDs) and the ß-ionone content during the withering period revealed CsCCD4 as the most promising candidate. The full-length CsCCD4 gene was amplified from C. sinensis, and the biochemical function of the recombinant CsCCD4 protein was studied after coexpression in Escherichia coli strains engineered to accumulate ß-carotene. The recombinant protein was able to cleave a variety of carotenoids at the 9-10 and 9'-10' double bonds. Volatile ß-ionone was detected as the main product by gas and liquid chromatography-mass spectrometry. The accumulation of ß-ionone was consistent with the expression levels of CsCCD4 in different tissues and during the withering process. The CsCCD4 expression was induced by low temperature and mechanical damage stress but not by dehydration stress. The results demonstrate that CsCCD4 catalyzes the production of ß-ionone in the tea plant and provide insight into its formation mechanism during the withering process.


Assuntos
Camellia sinensis/enzimologia , Carotenoides/metabolismo , Dioxigenases/metabolismo , Norisoprenoides/metabolismo , Proteínas de Plantas/metabolismo , Sequência de Aminoácidos , Biocatálise , Camellia sinensis/química , Camellia sinensis/genética , Camellia sinensis/metabolismo , Dioxigenases/genética , Manipulação de Alimentos , Espectrometria de Massas , Filogenia , Folhas de Planta/química , Folhas de Planta/enzimologia , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Plantas/classificação , Plantas/enzimologia , Plantas/genética , Alinhamento de Sequência
4.
New Phytol ; 2019 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-31828806

RESUMO

Plants produce and emit terpenes, including sesquiterpenes, during growth and development, which serve different functions in plants. The sesquiterpene nerolidol has health-promoting properties and adds a floral scent to plants. However, the glycosylation mechanism of nerolidol and its biological roles in plants remained unknown. Sesquiterpene UDP-glucosyltransferases were selected by using metabolites-genes correlation analysis, and its roles in response to cold stress were studied. We discovered the first plant UGT (UGT91Q2) in tea plant, whose expression is strongly induced by cold stress and which specifically catalyzes the glucosylation of nerolidol. The accumulation of nerolidol glucoside was consistent with the expression level of UGT91Q2 in response to cold stress, as well as in different tea cultivars. The reactive oxygen species (ROS) scavenging capacity of nerolidol glucoside was significantly higher than that of free nerolidol. Down-regulation of UGT91Q2 resulted in reduced accumulation of nerolidol glucoside, ROS scavenging capacity and tea plant cold tolerance. Tea plants absorbed airborne nerolidol and converted it to its glucoside, subsequently enhancing tea plant cold stress tolerance. Nerolidol plays a role in response to cold stress as well as in triggering plant-plant communication in response to cold stress. Our findings reveal previously unidentified roles of volatiles in response to abiotic stress in plants.

5.
ACS Appl Mater Interfaces ; 11(40): 37365-37370, 2019 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-31536320

RESUMO

It is greatly important to understand the gas bubble behaviors and realize their reliable manipulation. There still remain many challenges in the capture, transport, and release of gas bubbles at a preferred location intelligently. Herein, we provide a simple approach to manufacture a composite film with poly(N-isopropylacrylamide) (PNIPAAM) and polypropylene that exhibits smart, reversible, and reliable regulation of gas bubble adhesive behaviors (high and low adhesion) by controlling the temperature (above or below the lower critical solution temperature). By adjusting the composite surface temperature, thermally driven interface switching between intermolecular and intramolecular hydrogen bonding of the PNIPAAM chains resulted in low and high adhesion of air bubbles in an aqueous medium. Gas bubbles could be precisely captured, directionally transported, and precisely released at any preferred location.

6.
Oncotarget ; 10(39): 3835-3839, 2019 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-31231463

RESUMO

The mutagenic effects of tobacco smoking increase the risk of the development of cancers of the lung, head and neck, and other anatomic sites. In a comparison of squamous cell carcinomas of the lung and the head and neck, we find that the immunomodulatory effects of smoking differ based on anatomic site. In both sites, the mutational signature of smoking is strongly associated with somatic mutational load. In head and neck squamous cell carcinoma, the mutational signature of tobacco exposure is associated with a strongly immunosuppressive tumor microenvironment. In contrast, in lung squamous cell carcinoma, the opposite effect is seen, with the tumor immune microenvironment significantly more inflamed. These effects are mirrored in rates of response to immune checkpoint inhibitor immunotherapy, which tend to be higher in smokers with lung cancer, but lower in smokers with head and neck cancer. We find a similarly strong immunosuppressive effect of smoking in non-cancerous lung epithelium. Taken together, our findings show that the effects of mutational signatures on the immune microenvironment and response to immunotherapy can be affected by context such as cancer type, anatomic site, and histology.

7.
PLoS Genet ; 15(2): e1007983, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30789902

RESUMO

The Fanconi Anemia (FA) pathway is a multi-step DNA repair process at stalled replication forks in response to DNA interstrand cross-links (ICLs). Pathological mutation of key FA genes leads to the inherited disorder FA, characterized by progressive bone marrow failure and cancer predisposition. The study of FA is of great importance not only to children suffering from FA but also as a model to study cancer pathogenesis in light of genome instability among the general population. FANCD2 monoubiquitination by the FA core complex is an essential gateway that connects upstream DNA damage signaling to enzymatic steps of repair. FAAP20 is a key component of the FA core complex, and regulated proteolysis of FAAP20 mediated by the ubiquitin E3 ligase SCFFBW7 is critical for maintaining the integrity of the FA complex and FA pathway signaling. However, upstream regulatory mechanisms that govern this signaling remain unclear. Here, we show that PIN1, a phosphorylation-specific prolyl isomerase, regulates the integrity of the FA core complex, thus FA pathway activation. We demonstrate that PIN1 catalyzes cis-trans isomerization of the FAAP20 pSer48-Pro49 motif and promotes FAAP20 stability. Mechanistically, PIN1-induced conformational change of FAAP20 enhances its interaction with the PP2A phosphatase to counteract SCFFBW7-dependent proteolytic signaling at the phosphorylated degron motif. Accordingly, PIN1 deficiency impairs FANCD2 activation and the DNA ICL repair process. Together, our study establishes PIN1-dependent prolyl isomerization as a new regulator of the FA pathway and genomic integrity.


Assuntos
Proteína 7 com Repetições F-Box-WD/metabolismo , Proteína do Grupo de Complementação D2 da Anemia de Fanconi/metabolismo , Proteínas de Grupos de Complementação da Anemia de Fanconi/metabolismo , Peptidilprolil Isomerase de Interação com NIMA/metabolismo , Proteína Fosfatase 2/metabolismo , Linhagem Celular , Reparo do DNA , Anemia de Fanconi/genética , Anemia de Fanconi/metabolismo , Proteína do Grupo de Complementação A da Anemia de Fanconi/metabolismo , Proteínas de Grupos de Complementação da Anemia de Fanconi/química , Proteínas de Grupos de Complementação da Anemia de Fanconi/genética , Células HEK293 , Humanos , Isomerismo , Mutação , Proteólise , Transdução de Sinais
8.
Microb Drug Resist ; 25(2): 297-303, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30676248

RESUMO

BACKGROUND: To identify the potential risk factors for multiantibiotic-resistant infections and provide sufficient evidence for multiantibiotic resistance prevention and control. MATERIALS AND METHODS: We conducted a retrospective study of all patients in pediatric orthopedics, pediatric heart surgery, and pediatric general surgery at a level 3, grade A children's hospital from January to December 2016. The clinical laboratory information monitoring system and the medical record system were used to collect patient information regarding age, surgery type, preoperative length of stay, admission season, incision type, preoperative infection, intraoperative blood loss, postoperative use of invasive equipment, duration of catheter drainage, and timepoint of intraoperative prophylactic antibiotics administration. We used logistic univariate and multivariate regression analysis to analyze the potential risk factors for multiantibiotic-resistant infections among pediatric surgical patients. SPSS 21.0 and Excel software packages were used for the statistical analysis. RESULTS: In total, 2,973 patients met the inclusion criteria: 1,247 patients in pediatric orthopedics, 1,089 patients in pediatric heart surgery, and 637 patients in pediatric general surgery. At the end of the study, 113 patients were multiantibiotic-resistant infection cases; the rate of multiantibiotic-resistant infections was 3.80%, and the detection rate was 84.79%. Multivariate analysis indicated that the multiantibiotic-resistant infection cases were influenced by age, department, admission season, incision type, preoperative infection, and duration of catheter drainage. CONCLUSIONS: Age, department, admission season, incision type, preoperative infection, and duration of catheter drainage may provide possible evidence for prevention and control strategies of multiantibiotic-resistant infections.


Assuntos
Infecções Bacterianas/epidemiologia , Farmacorresistência Bacteriana Múltipla , Cirurgia Geral , Hospitais Pediátricos , Pacientes , Adolescente , Fatores Etários , Antibioticoprofilaxia , Infecções Bacterianas/microbiologia , Perda Sanguínea Cirúrgica , Procedimentos Cirúrgicos Cardíacos , Estudos de Casos e Controles , Cateterismo , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Tempo de Internação , Masculino , Estudos Retrospectivos , Fatores de Risco , Infecção da Ferida Cirúrgica/tratamento farmacológico , Infecção da Ferida Cirúrgica/microbiologia
9.
ACS Nano ; 12(12): 11995-12003, 2018 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-30457835

RESUMO

Controlled propulsion of liquid droplets on a solid surface offers important applications in various fields, including fog harvesting, heat transfer, microfluidics, and microdevice technologies. The propulsion of the liquid droplet is realized only if the driven force exceeds the resistance force. Sometimes the directional propulsion of droplets only takes place at the Leidenfrost state to achieve enough lubrication for a vapor cushion. The thick vapor cushions levitate liquid droplets to reduce resistance force. However, it is still challenging to reduce the vapor cushion thickness and simultaneously realize the directional droplet's motion, especially below the Leidenfrost temperature. Here, a structurally hydrophobic boron nitride nanosheet (BNNS) grid surface was constructed with a two-direction topographical gradient, i. e., the perpendicular altitude gradient and the horizontal density gradient. The polar nature of the B-N bonds results in intrinsic hydrophilicity of the boron nitride layer, which increases the Leidenfrost point and facilitates wetting even at high temperature. Much thinner vapor-lubricating layers are competent in the droplet's directional motion below the Leidenfrost temperature of the BNNS grid surface because the air gap trapped within boron nitride nanosheet grids acts as a part of the lubrication layer.

10.
ACS Appl Mater Interfaces ; 10(3): 3076-3081, 2018 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-29294280

RESUMO

Manipulation of gas bubble behaviors is crucial for gas bubble-related applications. Generally, the manipulation of gas bubble behaviors generally takes advantage of their buoyancy force. It is very difficult to control the transportation of gas bubbles in a specific direction. Several approaches have been developed to collect and transport bubbles in aqueous media; however, most reliable and effective manipulation of gas bubbles in aqueous media occurs on the interfaces with simple shapes (i.e., cylinder and cone shapes). Reliable strategies for spontaneous and directional transport of gas bubbles on interfaces with complex shapes remain enormously challenging. Herein, a type of 3D gradient porous network was constructed on copper wire interfaces, with rectangle, wave, and helix shapes. The superhydrophobic copper wires were immersed in water, and continuous and stable gas films then formed on the interfaces. With the assistance of the Laplace pressure gradient between two bubbles, gas bubbles (including microscopic gas bubbles) in the aqueous media were subsequently transported, continuously and directionally, on the copper wires with complex shapes. The small gas bubbles always moved to the larger ones.

11.
ACS Appl Mater Interfaces ; 10(5): 5099-5106, 2018 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-29327912

RESUMO

Gas bubbles in aqueous media are ubiquitous in a broad range of applications. In most cases, the size of the bubbles must be manipulated precisely. However, it is very difficult to control the size of gas bubbles. The size of gas bubbles is affected by many factors both during and after the generation process. Thus, precise manipulation of gas bubble size still remains a great challenge. The ratchet and conical hairs of the Chinese brush enable it to realize a significant capacity for holding ink and transferring them onto paper continuously and controllably. Inspired by this, a superhydrophobic/superaerophilic cone interface is developed to manipulate gas bubble size in aqueous media. When the resultant force between the Laplace force and the axial component of the buoyancy force approaches zero, the gas bubble is held steadily by the superhydrophobic/superaerophilic copper cones in a unique position (balance position). A new kind of pressure sensor is also designed based on this principle.

12.
Adv Mater ; 29(45)2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28902967

RESUMO

Gas bubbles in aqueous media are common and inevitable in, for example, agriculture and industrial processes. The behaviors of gas bubbles on solid interfaces, including generation, growth, coalescence, release, transport, and collection, are crucial to gas-bubble-related applications, which are always determined by gas-bubble wettability on solid interfaces. Here, the recent progress regarding the study of interfaces with gas-bubble superwettability in aqueous media, i.e., superaerophilicity and superaerophobicity, is summarized. Some examples illustrate how to design microstructures and chemical compositions to achieve reliable and effective manipulation of gas-bubble wettability on artificial interfaces. These designed interfaces exhibit excellent performance in gas-evolution reactions, gas-adsorption reactions, and directional gas-bubble transportation. Moreover, progress in the theoretical investigation of gas-bubble superwettability is reported. Lastly, some challenges are presented, such as the reliable manipulation of gas-bubble wettability and the establishment of mature theory for exactly and systematically explaining gas-bubble wetting phenomena.

13.
Oncol Lett ; 14(4): 4741-4745, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28943965

RESUMO

The aim of the study was to investigate the effect of three-dimensional conformal radiation therapy (3D-CRT) on nasopharyngeal carcinoma (NPC) and the incidence of complications. Between May 2010 and June 2012, 141 patients diagnosed with local recurrence of NPC due to cranial base lesions or cranial nerve symptoms, confirmed by pathology biopsy and/or by CT/MRI, were included in the present study. In accordance with the principle of randomized control, the patients were divided into three groups and treated with three different doses of 3D-CRT. The planned radiotherapy doses of 3D-CRT were 58/1.8-2 Gy, 62/1.8-2 Gy and 68/1.8-2 Gy, respectively. The survival rate, disease-free survival (DFS) rate and local control rate of the three groups of patients were compared as well as the adverse reactions observed after radiotherapy. The prognoses of NPC patients were analyzed by univariate and multivariate analyses. The follow-up rate of the study was 100%. The 5-year overall survival, DFS, and locoregional recurrence-free survival rates were: 43.2 vs. 64.53 vs. 75%, 29.13 vs. 42.82 vs. 39.7% and 30.76 vs. 44.19 vs. 45.4%, respectively. In addition, 62/1.8-2 Gy was similar in treatment effects to 68/1.8-2 Gy, but 68/1.8-2 Gy showed more adverse reactions than 62/1.8-2 Gy. Thus, 62/1.8-2 Gy can be used as a safe and effective dose for 3D-CRT treatment of NPC. Univariate and multivariate analyses showed that age may be the main prognostic factor of patients with NPC. In conclusion, 3D-CRT with a dose of 62/1.8-2 Gy is a safe, effective and tolerable treatment for NPC patients with good clinical value.

14.
Sci Rep ; 7: 40017, 2017 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-28067245

RESUMO

Some studies have reported that scaffold or cell-based transplantation may improve functional recovery following SCI, but no imaging information regarding regeneration has been provided to date. This study used tractography to show the regenerating process induced by a new biomaterial-aligned fibrin hydrogel (AFG). A total of eight canines subjected to SCI procedures were assigned to the control or the AFG group. AFG was implanted into the SCI lesion immediately after injury in 5 canines. A follow-up was performed at 12 weeks to evaluate the therapeutic effect including the hindlimb functional recovery, anisotropy and continuity of fibers on tractography. Using tractography, we found new fibers running across the SCI in three canines of the AFG group. Further histological examination confirmed limited glial scarring and regenerated nerve fibers in the lesions. Moreover, Repeated Measures Analysis revealed a significantly different change in fractional anisotropy (FA) between the two groups during the follow-up interval. An increase in FA during the post injury time interval was detected in the AFG group, indicating a beneficial effect of AFG in the rehabilitation of injured axons. Using tractography, AFG was suggested to be helpful in the restoration of fibers in SCI lesions, thus leading to promoted functional recovery.


Assuntos
Fibrina/química , Hidrogéis/química , Traumatismos da Medula Espinal/tratamento farmacológico , Medula Espinal/fisiologia , Animais , Imagem de Tensor de Difusão , Cães , Hidrogéis/farmacologia , Hidrogéis/uso terapêutico , Masculino , Projetos Piloto , Recuperação de Função Fisiológica , Regeneração/efeitos dos fármacos , Medula Espinal/diagnóstico por imagem , Traumatismos da Medula Espinal/diagnóstico por imagem , Traumatismos da Medula Espinal/patologia
15.
ACS Nano ; 10(12): 10887-10893, 2016 12 27.
Artigo em Inglês | MEDLINE | ID: mdl-28024340

RESUMO

Microbubbles are tiny bubbles with diameters below 50 µm. Because of their minute buoyant force, the microbubbles stagnate in aqueous media for a long time, and they sometimes cause serious damage. Most traditional methods chosen for elimination of gas bubbles utilize buoyancy forces including chemical methods and physical methods, and they only have a minor effect on microbubbles. Several approaches have been developed to collect and transport microbubbles in aqueous media. However, the realization of innovative strategies to directly collect and transport microbubbles in aqueous media remains a big challenge. In nature, both spider silk and cactus spines take advantage of their conical-shaped surface to yield the gradient of Laplace pressure and surface free energy for collecting fog droplets from the environment. Inspired by this, we introduce here the gradient of Laplace pressure and surface free energy to the interface of superhydrophobic copper cones (SCCs), which can continuously collect and directionally transport CO2 microbubbles (from tip side to base side) in CO2-supersaturated solution. A gas layer was formed when the microbubbles encounter the SCCs. This offers a channel for microbubble directional transportation. The efficiency of microbubble transport is significantly affected by the apex angle of SCCs and the carbon dioxide concentration. The former provides different gradients of Laplace pressure as the driving force. The latter represents the capacity, which offers the quantity of CO2 microbubbles for collection and transportation. We believe that this approach provides a simple and valid way to remove microbubbles.

16.
PLoS Genet ; 12(12): e1006465, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27906959

RESUMO

Maintaining genomic integrity during DNA replication is essential for cellular survival and for preventing tumorigenesis. Proliferating cell nuclear antigen (PCNA) functions as a processivity factor for DNA replication, and posttranslational modification of PCNA plays a key role in coordinating DNA repair against replication-blocking lesions by providing a platform to recruit factors required for DNA repair and cell cycle control. Here, we identify human SDE2 as a new genome surveillance factor regulated by PCNA interaction. SDE2 contains an N-terminal ubiquitin-like (UBL) fold, which is cleaved at a diglycine motif via a PCNA-interacting peptide (PIP) box and deubiquitinating enzyme activity. The cleaved SDE2 is required for negatively regulating ultraviolet damage-inducible PCNA monoubiquitination and counteracting replication stress. The cleaved SDE2 products need to be degraded by the CRL4CDT2 ubiquitin E3 ligase in a cell cycle- and DNA damage-dependent manner, and failure to degrade SDE2 impairs S phase progression and cellular survival. Collectively, this study uncovers a new role for CRL4CDT2 in protecting genomic integrity against replication stress via regulated proteolysis of PCNA-associated SDE2 and provides insights into how an integrated UBL domain within linear polypeptide sequence controls protein stability and function.


Assuntos
Carcinogênese/genética , Reparo do DNA/genética , Replicação do DNA/genética , Proteínas de Ligação a DNA/genética , Antígeno Nuclear de Célula em Proliferação/genética , Ubiquitina-Proteína Ligases/genética , Quimiocina CXCL12/genética , Dano ao DNA/genética , Células HeLa , Humanos , Antígeno Nuclear de Célula em Proliferação/metabolismo , Estabilidade Proteica/efeitos da radiação , Proteólise/efeitos da radiação , Fase S/genética , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinação/genética , Ubiquitinação/efeitos da radiação , Raios Ultravioleta
17.
Oncotarget ; 7(24): 35724-35740, 2016 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-27232758

RESUMO

Mutations that deregulate protein degradation lead to human malignancies. The SCF ubiquitin E3 ligase complex degrades key oncogenic regulators, thereby limiting their oncogenic potential. FBW7 is a substrate recognition subunit of SCFFBW7 and is among the most commonly mutated ubiquitin-proteasome system proteins in cancer. FBW7-mutated cancer cells display increased genome instability, but the molecular mechanism by which FBW7 preserves genome integrity remains elusive. Here, we demonstrate that SCFFBW7 regulates the stability of FAAP20, a critical component of the Fanconi anemia (FA) DNA interstrand cross-link (ICL) repair pathway. Phosphorylation of the FAAP20 degron motif by GSK3ß provides a platform for recognition and polyubiquitination of FAAP20 by FBW7, and its subsequent degradation by the proteasome. Accordingly, enhanced GSK3ß-FBW7 signaling disrupts the FA pathway. In cells expressing non-phosphorylatable FAAP20 mutant, the turnover of its binding partner, FANCA, is deregulated in the chromatin during DNA ICL repair, and the FA pathway is compromised. We propose that FAAP20 degradation, which is prompted by its phosphorylation, controls the dynamics of the FA core complex required for completing DNA ICL repair. Together, this study provides insights into how FBW7-mediated proteolysis regulates genome stability and how its deregulation is associated with tumorigenesis.


Assuntos
Reparo do DNA , Proteína 7 com Repetições F-Box-WD/metabolismo , Proteínas de Grupos de Complementação da Anemia de Fanconi/metabolismo , Proteínas Ligases SKP Culina F-Box/metabolismo , Ubiquitinação , Linhagem Celular Tumoral , Dano ao DNA , Replicação do DNA , Proteína 7 com Repetições F-Box-WD/genética , Técnicas de Silenciamento de Genes , Instabilidade Genômica , Glicogênio Sintase Quinase 3 beta/genética , Glicogênio Sintase Quinase 3 beta/metabolismo , Humanos , Redes e Vias Metabólicas , Neoplasias/genética , Neoplasias/metabolismo , Fosforilação , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteólise , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Transdução de Sinais
18.
Adv Mater ; 27(14): 2384-9, 2015 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-25688855

RESUMO

A series of well-ordered, 3D gradient porous interconnected network surfaces composed of micro-nano hierarchical geometries is constructed on a copper wire. A continuous gas film can be trapped around its interface in an aqueous medium acting as an effective channel for gas transportation. Driving by the difference of the Laplace pressure, gas bubbles can be transported spontaneously and directionally.


Assuntos
Biomimética/métodos , Gases/química , Água/química , Cobre/química , Interações Hidrofóbicas e Hidrofílicas , Movimento (Física) , Porosidade , Propriedades de Superfície
19.
ACS Appl Mater Interfaces ; 6(17): 15198-208, 2014 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-25141234

RESUMO

We studied the in situ transition of the droplets' wetting state on the heated solid surfaces. The wetting behaviors of four micro- and nanostructured surfaces with different chemical components were studied. These parameters included the maximum contact areas (MCA), the maximum evaporation areas (MEA) and the wetting transition temperature (T(trans)). The reduction in MEAs has a specific transition process from wetting (Wenzel state) or partial wetting (Wenzel-Cassie intermediate state) to nonwetting (Cassie State) as the surface temperature rises. When the MEAs drop to zero at a critical temperature (T(trans)), the droplets rebound from the heated surfaces to complete the wetting transition process. The chemical compounds and the surfaces' rough structure play an important role in the droplets' wetting transition behavior. Before FAS-modification, microstructures can increase the MCAs, MEAs, and T(trans). However, the microstructures are less effective at increasing the MEAs and T(trans) than changes to nanostructures. After FAS-modification, both the nano- and microstructures reduce the T(trans). On the FAS-MNSi surfaces, the MEAs are always zero--the droplets rebounded at room temperature, and the wetting transition did occur. We propose two high-temperature mechanisms to explain these transition phenomena.

20.
Langmuir ; 30(21): 6095-103, 2014 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-24810460

RESUMO

The effect of hydrostatic pressure on 6 µL air bubbles formed on micropillar structured PDMS and silicone surfaces using a 2 mm diameter stainless steel tip retreated at 1 mm/s was investigated. Dimensional analysis of the tip retraction process showed the experiments to be conducted in the condition where fluid inertial forces are comparable in magnitude with surface tension forces, while viscous forces were lower. Larger bubbles could be left behind on the structured PDMS surface. For hydrostatic pressures in excess of 20 mm H2O (196 Pa), the volume of bubble deposited was found to decrease progressively with pressure increase. The differences in width of the deposited bubbles (in contact with the substrate) were significant at any particular pressure but marginal in height. The attainable height before rupture reduced with pressure increase, thereby accounting for the reducing dispensed volume characteristic. On structured PDMS, the gaseous bridge width (in contact with the substrate) was invariant with tip retraction, while on silicone it was initially reducing before becoming invariant in the lead up to rupture. With silicone, hence, reductions in the contact width and height were both responsible for reduced volumes with pressure increase. Increased hydrostatic pressure was also found to restrict the growth in contact width on silicone during the stage when air was injected in through the tip. The ability to effect bubble size in such a simple manner may already be harnessed in nature and suggests possibilities in technological applications.

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