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1.
Nanotechnology ; 31(43): 435503, 2020 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-32650316

RESUMO

High-performance electronics demand extremely sensitive piezo-resistive sensors with important features such as low-fabrication cost, easy implementation, low power consumption and high-pressure sensitivity over broad pressure range. Herein, we report a flexible piezo-resistive paper-based device functionalised by WSe2 nanosheets. An efficient and low-cost fabrication strategy using Whatman filter paper and tissue paper is adopted for versatile sensing applications. The WSe2 nanosheets were synthesized by high-yield and size-controlled liquid phase exfoliation technique. The flexible WSe2 nanosheets-paper sensor shows excellent response in broad pressure range of 1 Pa-100 kPa with exceptionally high sensitivity of 29.24 kPa-1, current responsivity of 70 and response time of 100 ms. The pressure sensor is also employed to recognize the pressure generated due to finger tapping. Encouragingly, the piezo-resistive sensors can also sense extremely small pressure differences of about 1.4 Pa generated by water drops.

2.
Indian J Exp Biol ; 51(12): 1055-62, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24579370

RESUMO

Octapeptide (OP)/FSH-Receptor Binding Inhibitor-8 (FRBI-8), is a synthetic peptide corresponding to N-terminal sequence of purified fraction of Follicle Stimulating Hormone Binding-Inhibitor (FSHBI), isolated earlier from human ovarian follicular-fluid. In order to avoid the repeated drug-administration, OP-loaded, polymeric polylactide (PLA) nanoparticle formulation (NP-OP), was developed using multiple-emulsion technique. This yielded an average particle size of 120 nm with 70% encapsulation-efficiency. In vitro release profile of NP-OP showed sustained release of OP for 21 days. In vivo anti-fertility studies were conducted in marmosets. Results indicated that control animals conceived in the same cycle while two of three treated animals failed to conceive in treatment cycle. The in vivo studies thus corroborate with in vitro release of OP, demonstrating its anti-fertility activity in 66% of animals.


Assuntos
Proteínas de Transporte/química , Anticoncepção , Nanopartículas/química , Folículo Ovariano/química , Fragmentos de Peptídeos/química , Animais , Callithrix/fisiologia , Proteínas de Transporte/administração & dosagem , Feminino , Humanos , Nanopartículas/administração & dosagem , Tamanho da Partícula , Fragmentos de Peptídeos/administração & dosagem , Polímeros/administração & dosagem , Polímeros/química
4.
J Colloid Interface Sci ; 584: 495-504, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33129159

RESUMO

The advancement of portable and flexible electronics that is integrated with multiple sensing functions has increasingly drawn considerable interest. The fabricated sensors would have the ability to sense multiple deformations like pressing, twisting and trivial vibrations such as pulses of wrist vibrations to mimic human skin. Presently, we implemented an easy, cost-effective and optimized fabrication technique for production of pressure sensors based on MoSe2 nanosheets coated on cellulose paper. The present sensor exhibits an incorporation of large pressure sensitivity of 18.42 kPa-1 in pressure range 0.001-0.5 kPa, 7.28 kPa-1 in pressure range 1-35 kPa and 2.63 kPa-1 in pressure range 40-100 kPa, working in broad pressure range (from 0.001 to 100 kPa) and long-term stability up to 200 deformation cycles at 2 kPa. The sensor showed excellent response towards the detection of vibrations of machines including cellular phone, compressor, etc. Besides, the sensor shows excellent environmental stability and exhibits immune piezo-resistive response to temperature variation.


Assuntos
Eletrônica , Punho , Humanos , Pressão , Temperatura
5.
Neuroscience ; 479: 70-90, 2021 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-34648866

RESUMO

Deficiency in peroxisome proliferator-activated receptor gamma coactivator 1-alpha. (PGC-1α) expression or function is implicated in numerous neurological and psychiatric disorders. PGC-1α is required for the expression of genes involved in synchronous neurotransmitter release, axonal integrity, and metabolism, especially in parvalbumin-positive interneurons. As a transcriptional coactivator, PGC-1α requires transcription factors to specify cell-type-specific gene programs; while much is known about these factors in peripheral tissues, it is unclear if PGC-1α utilizes these same factors in neurons. Here, we identified putative transcription factors controlling PGC-1α-dependent gene expression in the brain using bioinformatics and then validated the role of the top candidate in a knockout mouse model. We transcriptionally profiled cells overexpressing PGC-1α and searched for over-represented binding motifs in the promoters of upregulated genes. Binding sites of the estrogen-related receptor (ERR) family of transcription factors were enriched, and blockade of ERRα attenuated PGC-1α-mediated induction of mitochondrial and synaptic genes in cell culture. Localization in the mouse brain revealed enrichment of ERRα expression in parvalbumin-expressing neurons with tight correlation of expression with PGC-1α across brain regions. In ERRα null mice, PGC-1α-dependent genes were reduced in multiple regions, including neocortex, hippocampus, and cerebellum, though not to the extent observed in PGC-1α null mice. Behavioral assessment revealed ambulatory hyperactivity in response to amphetamine and impairments in sensorimotor gating without the overt motor impairment characteristic of PGC-1α null mice. These data suggest that ERRα is required for normal levels of expression of PGC-1α-dependent genes in neurons but that additional factors may be involved in their regulation.


Assuntos
Encéfalo , Receptores de Estrogênio , Animais , Encéfalo/metabolismo , Expressão Gênica , Regulação da Expressão Gênica , Camundongos , Camundongos Knockout , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/genética , Receptores de Estrogênio/genética , Receptores de Estrogênio/metabolismo , Fatores de Transcrição , Receptor ERRalfa Relacionado ao Estrogênio
6.
J Exp Med ; 194(12): 1699-709, 2001 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-11748272

RESUMO

Leukocyte infiltration into inflammatory sites is regulated by the expression of adhesion and activation proteins, yet the role of these proteins in shear-dependent transmigration is poorly understood. We examined eosinophil recruitment on cytokine-stimulated human umbilical vein endothelial cells (HUVECs) under laminar flow conditions. Eosinophils rapidly transmigrated on interleukin (IL)-4-, but not TNF-stimulated HUVECs. Transmigration was shear dependent, with up to 90% of eosinophils transmigrating in the presence of shear and less than 25% of cells transmigrating under static conditions. Eosinophils express CC chemokine receptor CCR3 and are responsive to various CC chemokines. The effects of chemokines are mediated primarily through G(alpha)i, which is pertussis toxin sensitive. Greater than 65% of shear-dependent eosinophil transmigration on IL-4-stimulated HUVECs was blocked by either pertussis toxin or by an anti-CCR3 monoclonal antibody. Using reverse transcription polymerase chain reaction (RT-PCR) and Western blots, we found that IL-4-stimulated HUVECs produce both mRNA and protein for eotaxin-3. Eotaxin-3 was both released by HUVECs and expressed on the endothelial cell surface. Pretreatment of HUVECs with an anti-eotaxin-3 antibody blocked eosinophil transmigration to the same extent as an anti-CCR3 antibody. These results indicate that IL-4-stimulated HUVECs support shear-dependent eosinophil transmigration by upregulating eotaxin-3, and that surface association is critical for the role of eotaxin-3 in transmigration.


Assuntos
Movimento Celular/fisiologia , Quimiocinas CC/fisiologia , Endotélio Vascular/fisiologia , Eosinófilos/fisiologia , Adulto , Células Cultivadas , Quimiocina CCL26 , Fatores Quimiotáticos/fisiologia , Endotélio Vascular/citologia , Eosinófilos/citologia , Humanos , Receptores CCR3 , Receptores de Quimiocinas/fisiologia , Estresse Mecânico
7.
J Exp Med ; 184(1): 81-92, 1996 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-8691152

RESUMO

During acute inflammation, P-selectin is transiently mobilized from Weibel-Palade bodies to the surface of histamine-activated endothelial cells, where it mediates rolling adhesion of neutrophils under hydrodynamic flow. During chronic or allergic inflammation, sustained expression of P-selectin on the endothelial cell surface has been observed. We found that the cytokines interleukin 4 (IL-4) or oncostatin M (OSM) induced a five- to ninefold increase in P-selectin messenger RNA (mRNA) in human umbilical vein endothelial cells (HUVEC) that persisted as long as 72 h. IL-4 elevated P-selectin mRNA by increasing its transcription rate rather than by prolonging its already long half-life. Stimulation of P-selectin transcription by IL-4 or OSM required new protein synthesis and tyrosine phosphorylation of cellular proteins. Tumor necrosis factor alpha, IL-1 beta, lipopolysaccharide, or IL-3 did not increase P-selectin mRNA in HUVEC, and did not augment the IL-4-induced increase in P-selectin transcripts. IL-4 or OSM increased P-selectin protein on the cell surface as well as in Weibel-Palade bodies. Under flow conditions, neutrophils rolled on P-selectin expressed by IL-4-treated HUVEC, and even more neutrophils rolled on P-selectin after IL-4-treated HUVEC were stimulated with histamine. These data demonstrate that IL-4 or OSM stimulates endothelial cells to synthesize more P-selectin over prolonged periods. The increased expression of P-selectin may facilitate the emigration of leukocytes into sites of chronic or allergic inflammation.


Assuntos
Endotélio Vascular/metabolismo , Interleucina-4/fisiologia , Selectina-P/metabolismo , Peptídeos/fisiologia , Animais , Benzoquinonas , Adesão Celular , Células Cultivadas , Selectina E/genética , Inibidores Enzimáticos/farmacologia , Regulação da Expressão Gênica , Genisteína , Humanos , Interleucina-1/farmacologia , Interleucina-3/farmacologia , Isoflavonas/farmacologia , Lactamas Macrocíclicas , Lipopolissacarídeos/farmacologia , Camundongos , Neutrófilos/citologia , Oncostatina M , Selectina-P/genética , Proteínas Tirosina Quinases/antagonistas & inibidores , Quinonas/farmacologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Rifabutina/análogos & derivados , Fator de Necrose Tumoral alfa/farmacologia , Molécula 1 de Adesão de Célula Vascular/genética
8.
Clin Immunol ; 133(2): 251-6, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19665935

RESUMO

Inflammation is an important element in the development and destabilization of atherosclerotic plaque. Using a high sensitivity multiplex assay, previously untested in the context of atherosclerotic disease, we determined serum concentrations of GM-CSF, IFNgamma, IL-1beta, IL-2, IL-10, IL-12p70, TNF alpha, IL-6, and IL-8 in 48 Myocardial Infarction (MI) patients, 14 Unstable Angina (UA) patients and 12 healthy controls. IFNgamma levels were significantly higher in MI compared to UA (p=0.0091) and Control groups (p=0.0014). IL-10 also showed higher expression levels between MI, UA groups and Controls (p=0.0299).This up-regulation may reflect the extent of plaque instability and/or rupture in MI patients.Our observations provide evidence that IFNgamma and IL-10 merit further investigation in atherosclerotic disease states as potential markers of disease and therapeutic targets.


Assuntos
Síndrome Coronariana Aguda/sangue , Interferon gama/sangue , Interleucina-10/sangue , Infarto do Miocárdio/sangue , Regulação para Cima , Idoso , Angina Instável/sangue , Proteína C-Reativa/metabolismo , Citocinas/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
9.
J Cell Biol ; 131(6 Pt 2): 1893-902, 1995 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8557755

RESUMO

Under physiological shear stress, neutrophils roll on P-selectin on activated endothelial cells or platelets through interactions with P-selectin glycoprotein ligand-1 (PSGL-1). Both P-selectin and PSGL-1 are extended molecules. Human P-selectin contains an NH2-terminal lectin domain, an EGF domain, nine consensus repeats (CRs), a transmembrane domain, and a cytoplasmic tail. To determine whether the length of P-selectin affected its interactions with PSGL-1, we examined the adhesion of neutrophils to CHO cells expressing membrane-anchored P-selectin constructs in which various numbers of CRs were deleted. Under static conditions, neutrophils attached equivalently to wild-type P-selectin and to constructs containing from 2-6 CRs. Under shear stress, neutrophils attached equivalently to wild-type and 6 CR P-selectin and nearly as well to 5 CR P-selectin. However, fewer neutrophils attached to the 4 CR construct, and those that did attach rolled faster and were more readily detached by increasing shear stress. Flowing neutrophils failed to attach to the 3 CR and 2 CR constructs. Neutrophils attached and rolled more efficiently on 4 CR P-selectin expressed on glycosylation-defective Lec8 CHO cells, which have less glycocalyx. We conclude that P-selectin must project its lectin domain well above the membrane to mediate optimal attachment of neutrophils under shear forces. The length of P-selectin may: (a) facilitate interactions with PSGL-1 on flowing neutrophils, and (b) increase the intermembrane distance where specific bonds form, minimizing contacts between the glycocalyces that result in cell-cell repulsion.


Assuntos
Membrana Celular/química , Neutrófilos/citologia , Selectina-P/imunologia , Animais , Células CHO/citologia , Adesão Celular/imunologia , Movimento Celular/imunologia , Cricetinae , Glicoproteínas/genética , Humanos , Mutação/fisiologia , Selectina-P/análise , Selectina-P/genética , Polissacarídeos/genética , Proteínas Recombinantes de Fusão/imunologia
10.
J Cell Biol ; 112(4): 749-59, 1991 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-1704376

RESUMO

The initial step in extravasation of neutrophils (polymorphonuclear leukocytes [PMNs]) to the extravascular space is adherence to the endothelium. We examined the effect of oxidants on this process by treating human endothelial cells with H2O2, t-butylhydroperoxide, or menadione. This resulted in a surface adhesive for PMN between 1 and 4 h after exposure. The oxidants needed to be present only for a brief period at the initiation of the assay. Adhesion was an endothelial cell-dependent process that did not require an active response from the PMN. The adhesive molecule was not platelet-activating factor, which mediates PMN adherence when endothelial cells are briefly exposed to higher concentrations of H2O2 (Lewis, M. S., R. E. Whatley, P. Cain, T. M. McIntyre, S. M. Prescott, and G. A. Zimmerman. 1988. J. Clin. Invest. 82:2045-2055), nor was it ELAM-1, an adhesive glycoprotein induced by cytokines. Oxidant-induced adhesion did not require protein synthesis, was inhibited by antioxidants, and, when peroxides were the oxidants, was inhibited by intracellular iron chelators. Granule membrane protein-140 (GMP-140) is a membrane-associated glycoprotein that can be translocated from its intracellular storage pool to the surface of endothelial cells where it acts as a ligand for PMN adhesion (Geng, J.-G., M. P. Bevilacqua, K. L. Moore, T. M. McIntyre, S. M. Prescott, J. M. Kim, G. A. Bliss, G. A. Zimmerman, and R. P. McEver. 1990. Nature (Lond). 343:757-760). We found that endothelial cells exposed to oxidants expressed GMP-140 on their surface, and that an mAb against GMP-140 or solubilized GMP-140 completely blocked PMN adherence to oxidant-treated endothelial cells. Thus, exposure of endothelial cells to oxygen radicals induces the prolonged expression of GMP-140 on the cell surface, which results in enhanced PMN adherence.


Assuntos
Moléculas de Adesão Celular/biossíntese , Endotélio Vascular/metabolismo , Peróxidos/farmacologia , Glicoproteínas da Membrana de Plaquetas/biossíntese , Adesão Celular/efeitos dos fármacos , Moléculas de Adesão Celular/fisiologia , Selectina E , Endotélio Vascular/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Técnicas In Vitro , Neutrófilos/efeitos dos fármacos , Neutrófilos/metabolismo , Selectina-P , Fator de Ativação de Plaquetas/fisiologia
11.
J Cell Biol ; 115(1): 223-34, 1991 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-1717478

RESUMO

The adhesion of polymorphonuclear leukocytes (PMNs) to vascular endothelial cells (EC) is an early and fundamental event in acute inflammation. This process requires the regulated expression of molecules on both the EC and PMN. EC stimulated with histamine or thrombin coexpress two proadhesive molecules within minutes: granule membrane protein 140 (GMP-140), a member of the selectin family, and platelet-activating factor (PAF), a biologically active phospholipid. Coexpression of GMP-140 and PAF is required for maximal PMN adhesion and the two molecules act in a cooperative fashion. The component of adhesion mediated by EC-associated PAF requires activation of CD11/CD18 integrins on the PMN and binding of these heterodimers to counterreceptors on the EC. GMP-140 also binds to a receptor on the PMN; however, it tethers the PMN to the EC without requiring activation of CD11/CD18 integrins. This component of the adhesive interaction is blocked by antibodies to GMP-140 or by GMP-140 in the fluid phase. Experiments with purified GMP-140 indicate that binding to its receptor on the PMN does not directly induce PMN adhesiveness but that it potentiates the CD11/CD18-dependent adhesive response to PAF by a mechanism that involves events distal to the PAF receptor. Tethering of the PMN to the EC by GMP-140 may also be required for efficient interaction of PAF with its receptor on the PMN. These observations define a complex cell recognition system in which tethering of PMNs by a selectin, GMP-140, facilitates juxtacrine activation of the leukocytes by a signaling molecule, PAF. The latter event recruits the third component of the adhesive interaction, the CD11/CD18 integrins.


Assuntos
Antígenos CD/metabolismo , Moléculas de Adesão Celular/metabolismo , Endotélio Vascular/metabolismo , Histamina/farmacologia , Neutrófilos/fisiologia , Fator de Ativação de Plaquetas/metabolismo , Glicoproteínas da Membrana de Plaquetas/metabolismo , Trombina/farmacologia , Anticorpos Monoclonais/imunologia , Antígenos CD11 , Antígenos CD18 , Adesão Celular , Endotélio Vascular/citologia , Fibrinogênio/metabolismo , Humanos , Técnicas In Vitro , Neutrófilos/citologia , Selectina-P , Regulação para Cima
12.
J Cell Biol ; 128(4): 661-71, 1995 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-7532174

RESUMO

Neutrophils roll on P-selectin expressed by activated platelets or endothelial cells under the shear stresses in the microcirculation. P-selectin glycoprotein ligand-1 (PSGL-1) is a high affinity ligand for P-selectin on myeloid cells. However, it has not been demonstrated that PSGL-1 contributes to the rolling of neutrophils on P-selectin. We developed two IgG mAbs, PL1 and PL2, that appear to recognize protein-dependent epitopes on human PSGL-1. The mAbs bound to PSGL-1 on all leukocytes as well as on heterologous cells transfected with PSGL-1 cDNA. PL1, but not PL2, blocked binding of 125-I-PSGL-1 to immobilized P-selectin, binding of fluid-phase P-selectin to myeloid and lymphoid leukocytes, adhesion of neutrophils to immobilized P-selectin under static conditions, and rolling of neutrophils on P-selectin-expressing CHO cells under a range of shear stresses. PSGL-1 was localized to microvilli on neutrophils, a topography that may facilitate its adhesive function. These data indicate that (a) PSGL-1 accounts for the high affinity binding sites for P-selectin on leukocytes, and (b) PSGL-1 must interact with P-selectin in order for neutrophils to roll on P-selectin at physiological shear stresses.


Assuntos
Adesão Celular/fisiologia , Glicoproteínas de Membrana/metabolismo , Neutrófilos/fisiologia , Glicoproteínas da Membrana de Plaquetas/metabolismo , Sequência de Aminoácidos , Animais , Anticorpos Monoclonais , Especificidade de Anticorpos , Sequência de Bases , Western Blotting , Células CHO , Clonagem Molecular , Cricetinae , Fricção , Leucócitos/imunologia , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/imunologia , Glicoproteínas de Membrana/isolamento & purificação , Proteínas de Membrana/análise , Microscopia Imunoeletrônica , Microvilosidades/ultraestrutura , Dados de Sequência Molecular , Neutrófilos/imunologia , Neutrófilos/ultraestrutura , Selectina-P , Proteínas Recombinantes , Transfecção
13.
J Clin Invest ; 96(4): 1887-96, 1995 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7560080

RESUMO

Both P-selectin glycoprotein ligand-1 (PSGL-1) and L-selectin are localized on the microvilli of neutrophils and have been implicated in the attachment of neutrophils to P-selectin or E-selectin. We directly compared the attachment and rolling of neutrophils on P-selectin and E-selectin under flow, with emphasis on the functions of PSGL-1 and L-selectin. Flowing neutrophils attached more avidly and rolled at lower velocities on P-selectin than on E-selectin at matched densities. Studies with purified molecules indicated that P-selectin and E-selectin bound to a related site on PSGL-1 that overlapped the epitope for the anti-PSGL-1 mAb PL1. E-selectin bound with lower affinity than P-selectin to this site and also bound to an additional site(s) on PSGL-1.PL1 abolished adhesion of neutrophils to P-selectin under shear or static conditions, whereas DREG-56, a mAb to L-selectin, had no effect on adhesion to P-selectin. PL1 inhibited attachment of neutrophils to E-selectin under flow but not static conditions. DREG-56 also inhibited attachment of flowing neutrophils to E-selectin, and a combination of DREG-56 and PL1 nearly eliminated attachment to E-selectin under flow. These data suggest that PSGL-1 functions cooperatively with L-selectin to mediate optimal attachment of flowing neutrophils to E-selectin but not to P-selectin. Neutrophils attach more efficiently and with greater strength to P-selectin, perhaps because of the higher affinity of P-selectin for the PL1-defined site on PSGL-1.


Assuntos
Selectina E/fisiologia , Selectina L/fisiologia , Glicoproteínas de Membrana/fisiologia , Neutrófilos/fisiologia , Selectina-P/fisiologia , Animais , Anticorpos Monoclonais/imunologia , Células CHO , Adesão Celular , Cricetinae , Células HL-60 , Humanos , Resistência à Tração
14.
J Clin Invest ; 94(2): 631-42, 1994 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-7518841

RESUMO

Brown recluse spider (Loxosceles reclusa) venom induces severe dermonecrotic lesions. The mechanism for this is unknown but presents an interesting paradox: necrosis is completely dependent on the victim's neutrophils, yet neutrophils are not activated by the venom. We show Loxosceles venom is a potent, but disjointed, endothelial cell agonist. It weakly induced E-selectin expression, but not intercellular adhesion molecule-1 or IL-6 expression, yet significantly stimulated release of IL-8 and large amounts of GM-CSF by 4 h. In contrast, TNF strongly induced all of these, except for GM-CSF. PMN bound to E-selectin on venom-activated endothelial cells, apparently via counterreceptors different from those that bind E-selectin on TNF alpha-activated monolayers. Notably, PMN bound venom-activated monolayers only at intercellular junctions, did not polarize, and completely failed to migrate beneath the monolayer. Despite this, bound PMN demonstrated increased intracellular Ca2+ levels and secreted primary and secondary granule markers. The latter event was suppressed by sulfones used to treat envenomation. We have defined a new endothelial cell agonist, Loxosceles venom, that differentially stimulates the inflammatory response of endothelial cells. This, in turn, leads to a dysregulated PMN response where adhesion and degranulation are completely dissociated from shape change and transmigration.


Assuntos
Moléculas de Adesão Celular/biossíntese , Endotélio Vascular/efeitos dos fármacos , Fator Estimulador de Colônias de Granulócitos e Macrófagos/biossíntese , Interleucina-8/biossíntese , Neutrófilos/efeitos dos fármacos , Venenos de Aranha/farmacologia , Animais , Sequência de Bases , Comunicação Celular/efeitos dos fármacos , Células Cultivadas , Selectina E , Endotélio Vascular/fisiologia , Dados de Sequência Molecular , Neutrófilos/fisiologia , Fator de Necrose Tumoral alfa/farmacologia
16.
Nat Commun ; 6: 7312, 2015 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-26088416

RESUMO

Layered transition-metal dichalcogenides have emerged as exciting material systems with atomically thin geometries and unique electronic properties. Pressure is a powerful tool for continuously tuning their crystal and electronic structures away from the pristine states. Here, we systematically investigated the pressurized behavior of MoSe2 up to ∼ 60 GPa using multiple experimental techniques and ab-initio calculations. MoSe2 evolves from an anisotropic two-dimensional layered network to a three-dimensional structure without a structural transition, which is a complete contrast to MoS2. The role of the chalcogenide anions in stabilizing different layered patterns is underscored by our layer sliding calculations. MoSe2 possesses highly tunable transport properties under pressure, determined by the gradual narrowing of its band-gap followed by metallization. The continuous tuning of its electronic structure and band-gap in the range of visible light to infrared suggest possible energy-variable optoelectronics applications in pressurized transition-metal dichalcogenides.

17.
J Clin Pharmacol ; 26(5): 351-7, 1986.
Artigo em Inglês | MEDLINE | ID: mdl-2871054

RESUMO

Sixteen subjects scheduled for surgical procedures under general anesthesia participated in an investigation of the effects of esmolol on the transient hypertension and tachycardia that was observed during endotracheal intubation and on the duration of succinylcholine-induced neuromuscular blockade. In eight subjects, infusion of esmolol was begun five minutes before induction of anesthesia and continued for 12 minutes after induction. In the remaining subjects, an equivalent volume of solvent (D5W) was infused for 12 minutes. Infusion of esmolol significantly attenuated the cardioacceleration observed during intubation without any significant effect on the pressor effects of the procedure. Esmolol delayed the recovery from succinylcholine-induced neuromuscular blockade by less than three minutes. The mechanism of this delay remains to be investigated, although such a delay does not have clinical significance. Esmolol-induced attenuation of the tachycardia seen during intubation may offer a protective effect on the myocardium, especially in elderly subjects and patients with coronary artery disease.


Assuntos
Antagonistas Adrenérgicos beta/administração & dosagem , Anestesia Geral/métodos , Propanolaminas/administração & dosagem , Antagonistas Adrenérgicos beta/farmacologia , Adulto , Pressão Sanguínea/efeitos dos fármacos , Avaliação de Medicamentos , Interações Medicamentosas , Feminino , Frequência Cardíaca/efeitos dos fármacos , Humanos , Intubação Intratraqueal/efeitos adversos , Masculino , Pessoa de Meia-Idade , Junção Neuromuscular/efeitos dos fármacos , Propanolaminas/farmacologia , Succinilcolina/administração & dosagem , Transmissão Sináptica , Taquicardia/prevenção & controle
18.
Diagn Cytopathol ; 15(3): 221-3, 1996 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8955604

RESUMO

Cytological findings of sinus histiocytosis with massive lymphadenopathy (SHML), involving bilateral cervical lymph nodes of a 12-yr-old boy, are presented here. A striking feature was the presence of large histiocytes with abundant pale cytoplasm containing well-preserved lymphocytes, plasma cells, and occasional neutrophils, scattered in a background of reactive lymphoid cells. Subsequent open biopsy of the lymph node mass confirmed the cytologic findings. Cytologic features of SHML are virtually diagnostic and can negate the need for an open biopsy in most cases.


Assuntos
Histiocitose Sinusal/patologia , Doenças Linfáticas/patologia , Biópsia por Agulha , Criança , Humanos , Masculino
19.
Indian J Cancer ; 38(2-4): 137-42, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-12593453

RESUMO

Primary carcinoma arising from a paratubal cyst in the mesosalpinx in uncommon. Serous tumors of low malignant potential outnumber invasive carcinomas, which are often of endometrioid type. Only five cases of serous papillary cystadenocarcinoma with capsular invasion have been documented. We report a case of invasive papillary cystadenocarcinoma arising in a large paratubal cyst of the mesosalpinx, in an infertile woman. Possible hormonal basis, its link to serous borderline and malignant tumors of the peritoneum, and value of pre/intra operative cyst fluid cytology are discussed. Lack of definitive management protocols, prognostic indicators and possible consequences are briefly reviewed.


Assuntos
Doenças dos Anexos/patologia , Ligamento Largo/patologia , Cistadenocarcinoma Papilar/patologia , Cistos , Doenças dos Anexos/cirurgia , Adulto , Cistadenocarcinoma Papilar/cirurgia , Feminino , Humanos , Histerectomia
20.
J Colloid Interface Sci ; 425: 110-7, 2014 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-24776671

RESUMO

The preparation of ordered polymer gels from the amphiphilic block copolymers, Pluronic® F77, P123 and polyethylene glycol in the presence of ionic liquid, iodine and organic additives is presented. At 35%(w/w) concentration these copolymers (F77 and P123) self-assembled into cubic liquid crystalline phase in aqueous solution and characterized by using SAXS and AFM measurements. The effects of micellar aggregation formed by polymers on the ionic transport and triiodide diffusion have been studied by electrochemistry and SANS experiments. The ionic migration or triiodide diffusion through these polymer gels is found to be affected by the PEO/PPO content in the polymer backbone. These gels were successfully employed as an electrolyte in a dye sensitized solar cell. A remarkable solar to electricity conversion efficiency and good stability was obtained using Pluronic® F77 based gel, which is attributed to its thermoreversible sol to gel transition.

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