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1.
J Comput Chem ; 45(11): 804-819, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38135467

RESUMO

The inability of p-block elements to participate in π-backbonding restricts them from activating small molecules like CO, H2 , and so forth. However, the development of the main group metallomimetics became a new pathway, where the main-group elements like boron can bind and activate small molecules like CO and H2 . The concept of the frustrated Lewis pair, Boron-Boron multiple bonds, and borylene are previously illustrated. Some of these reported classes of boron species can mimic the jobs of the metal complexes. Hence, we have theoretically studied the binding of CO/N2 molecules at B-center of elusive species like sila/germa boryne stabilized by donor base ligands (cAAC)BE(Me)(L), where E  Si, L  cAACMe , NHCMe , PMe3 , E  Ge, L  cAACMe and (NHCMe )BE(Me)(cAACMe )). The substitutional analogues of (cAACR )BSiR1 (cAAC) and E  P, L  cAACMe ) have been studied by density functional theory (DFT), natural bond orbital, QTAIM calculations and energy decomposition analysis (EDA) coupled with natural orbital for chemical valence (NOCV) analyses. The computed bond dissociation energy and inner stability analyses by the EDA-NOCV method showed that the CO molecule can bind at the B-center of the above-mentioned species due to stronger σ-donor ability while binding of N2 has been theoretically predicted to be weak. The energy barrier for the CO binding is estimated to be 13-14 kcal/mol by transition state calculation. The change of partial triple bond character to single bond nature of the BSi bond and the bending of CBSi bond angle of sila-boryne species are the reason for the activation energy. Our study reveals the ability of such species to bind and activate the CO molecule to mimic the transition metal-containing complexes. We have additionally shown that binding of Fe(CO)4 and Ni(CO)3 is feasible at Si-center after binding of CO at the B-center.

2.
Proc Natl Acad Sci U S A ; 118(19)2021 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-33941671

RESUMO

Tsunami generation from earthquake-induced seafloor deformations has long been recognized as a major hazard to coastal areas. Strike-slip faulting has generally been considered insufficient for triggering large tsunamis, except through the generation of submarine landslides. Herein, we demonstrate that ground motions due to strike-slip earthquakes can contribute to the generation of large tsunamis (>1 m), under rather generic conditions. To this end, we developed a computational framework that integrates models for earthquake rupture dynamics with models of tsunami generation and propagation. The three-dimensional time-dependent vertical and horizontal ground motions from spontaneous dynamic rupture models are used to drive boundary motions in the tsunami model. Our results suggest that supershear ruptures propagating along strike-slip faults, traversing narrow and shallow bays, are prime candidates for tsunami generation. We show that dynamic focusing and the large horizontal displacements, characteristic of strike-slip earthquakes on long faults, are critical drivers for the tsunami hazard. These findings point to intrinsic mechanisms for sizable tsunami generation by strike-slip faulting, which do not require complex seismic sources, landslides, or complicated bathymetry. Furthermore, our model identifies three distinct phases in the tsunamic motion, an instantaneous dynamic phase, a lagging coseismic phase, and a postseismic phase, each of which may affect coastal areas differently. We conclude that near-source tsunami hazards and risk from strike-slip faulting need to be re-evaluated.

3.
J Comput Chem ; 44(1): 43-60, 2023 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-36169176

RESUMO

The factors/structural features which are responsible for the binding, activation and reduction of N2 to NH3 by FeMoco of nitrogenase have not been completely understood well. Several relevant model complexes by Holland et al. and Peters et al. have been synthesized, characterized and studied by theoretical calculations. For a matter of fact, those complexes are much different than real active N2 -binding Fe-sites of FeMoco, which possesses a central C(4-) ion having an eight valence electrons as an µ6 -bridge. Here, a series of [(S3 C(0))Fe(II/I/0)-N2 ]n- complexes in different charged/spin states containing a coordinated σ- and π-donor C(0)-atom which possesses eight outer shell electrons [carbone, (Ph3 P)2 C(0); Ph3 P→C(0)←PPh3 ] and three S-donor sites (i.e. - S-Ar), have been studied by DFT, QTAIM, and EDA-NOCV calculations. The effect of the weak field ligand on Fe-centres and the subsequent N2 -binding has been studied by EDA-NOCV analysis. The role of the oxidation state of Fe and N2 -binding in different charged and spin states of the complex have been investigated by EDA-NOCV analyses. The intrinsic interaction energies of the Fe-N2 bond are in the range from -42/-35 to -67 kcal/mol in their corresponding ground states. The S3 C(0) donor set is argued here to be closer to the actual coordination environment of one of the six Fe-centres of nitrogenase. In comparison, the captivating model complexes reported by Holland et al. and Peter et al. possess a stronger π-acceptor C-ring (S2 Cring donor, π-C donor) and stronger donor set like CP3 (σ-C donor) ligands, respectively.


Assuntos
Carbono , Nitrogenase , Nitrogenase/química , Carbono/química , Nitrogênio/química , Ligantes , Ferro/química
4.
Phys Chem Chem Phys ; 25(45): 31396-31409, 2023 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-37962035

RESUMO

This experimental study aimed to enhance the mechanical and thermal properties of BN (hexagonal boron nitride) nanosheet-reinforced high-density polyethylene by functionalizing its interface. The challenges associated with this nanocomposites are its poor dispersion and weak interface. Accordingly, to improve the load transfer at the interface, BN nanosheets were chemically modified with silane functional groups ((3-aminopropyl)tri-ethoxy silane), making it possible to form covalent bonds between the maleic anhydride-grafted polyethylene and nanosheet. Consequently, three different types of nanocomposite samples were fabricated based on the covalently bonded or non-bonded interface. Two nanocomposite configurations featured a non-bonded interface between the nanofiller and PE matrix (p-BN/PE and (silane functionalized) s-BN/PE). In contrast, the third configuration had a covalently bonded interface (silane-functionalized h-BN + maleic anhydride-grafted PE, i.e., PE-g-BN). According to the zeta potential analysis, the silane-functionalized BN nanosheets were stable suspensions and uniformly dispersed in the polymer matrix. The tensile and flexure strength of the nanocomposites showed over 100% improvement due to the covalently bonded interface. The lamellae structure of PE in the bonded interface samples was responsible for achieving higher mechanical strength in the nanocomposites. Furthermore, the thermal conductivity of the nanocomposites was significantly affected by the type of interfacial bonding, BN wt%, and operating temperature.

5.
Nature ; 545(7654): 336-339, 2017 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-28460375

RESUMO

Many of Earth's great earthquakes occur on thrust faults. These earthquakes predominantly occur within subduction zones, such as the 2011 moment magnitude 9.0 eathquake in Tohoku-Oki, Japan, or along large collision zones, such as the 1999 moment magnitude 7.7 earthquake in Chi-Chi, Taiwan. Notably, these two earthquakes had a maximum slip that was very close to the surface. This contributed to the destructive tsunami that occurred during the Tohoku-Oki event and to the large amount of structural damage caused by the Chi-Chi event. The mechanism that results in such large slip near the surface is poorly understood as shallow parts of thrust faults are considered to be frictionally stable. Here we use earthquake rupture experiments to reveal the existence of a torquing mechanism of thrust fault ruptures near the free surface that causes them to unclamp and slip large distances. Complementary numerical modelling of the experiments confirms that the hanging-wall wedge undergoes pronounced rotation in one direction as the earthquake rupture approaches the free surface, and this torque is released as soon as the rupture breaks the free surface, resulting in the unclamping and violent 'flapping' of the hanging-wall wedge. Our results imply that the shallow extent of the seismogenic zone of a subducting interface is not fixed and can extend up to the trench during great earthquakes through a torquing mechanism.

6.
Ophthalmic Physiol Opt ; 43(1): 132-140, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36271902

RESUMO

PURPOSE: We developed a clip-on light tracker (MyLyt) for estimating light exposure in real time. This study aimed at validating and investigating the feasibility of using MyLyt in children and adults. METHOD: The study was conducted in two phases. Phase 1 involved validation against a factory-calibrated digital lux meter in three separate conditions: controlled environmental set-up, outdoors and indoors where intra-test (two measurements by the same tracker), inter-test (measurements among trackers) and inter-device (MyLyt tracker and lux meter) validations were conducted. Phase 2 involved a feasibility study where MyLyt was used in a real-world setting by 21 adults and 8 children. Participants were asked to log their real-time movements in an 'activity diary', which were correlated with the lux levels measured by the tracker. RESULTS: A strong positive correlation and non-significant difference in the recorded mean illuminance levels were observed during intra-test (inter-class correlation: 1.00, p = 0.99), inter-test (0.91-1.00, p > 0.15) and inter-device (0.91-1.00, p > 0.56) validation in all three testing conditions (p > 0.49), except the indoor location. While the lux level measured by MyLyt was significantly higher than that of the lux meter (p < 0.01) in the indoor locations, differences were minimal and clinically insignificant. A Bland-Altman plot showed a minimal mean difference (95% limits of agreement) between the MyLyt tracker and lux meter in all three conditions (controlled environmental set-up: 641 [-949, 2230], outdoor: 74 [-2772, 2920] and indoor: -35 [-151, 80] lux). Phase 2 validation showed an expected illuminance level against the corresponding location with high sensitivity (97.8%) and specificity (99%) to accurately differentiate between outdoor and indoor locations. CONCLUSION: The MyLyt tracker showed good repeatability, strong correlation and comparable values with the lux meter in the three tested conditions, making it suitable for tracking light exposure patterns for both research and clinical purposes.


Assuntos
Criança , Humanos
7.
J Environ Manage ; 316: 115259, 2022 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-35658251

RESUMO

Nature-based solutions or Green infrastructure (GI) used for managing stormwater pollution are growing in popularity across the globe. Stormwater GI models are important tools to inform the planning of these systems (type, design, size), in the most efficient and cost-effective manner. MUSIC, an example of such a tool, uses regression and first order decay models. Studies validating MUSIC model performance are, however, scarce, hindering future model development and transferability of the model for systems operating under different design and climatic conditions. To close this gap, this paper evaluates MUSIC for a field scale bioretention system, stormwater wetland and vegetated swale operating under Singapore tropical climate. The treatment modules were able to simulate outflows and effluent pollutant concentrations reasonably well for cumulative event volumes (mostly within ±25%) and cumulative TP and TN loads (within ±30%). Outflow TSS loads were significantly under-estimated as a result of greater variability in measured TSS concentrations across events. The findings indicate that simple empirical models such as MUSIC can be transferred to different regions provided that management decisions are based on long-term modelling efforts. The modules generally simulated the outflow hydrographs and pollutographs of the different inflow and drying/wetting conditions relatively poorly.


Assuntos
Chuva , Qualidade da Água , Singapura , Movimentos da Água
8.
Orbit ; 41(1): 108-111, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32847452

RESUMO

Adult onset xanthogranulomatous disease is a rare orbital disease. IgG4-related disease is a systemic disease that can often manifest in the orbit. In this communication, we present the case of a patient with a xanthelasma-like lesion on the upper eyelid, and an enlarged lacrimal gland, which on biopsy was diagnosed as an orbital xanthogranuloma. Detailed serological workup showed that the patient was found to have elevated serum IgG4 levels. The orbital specimen was re-stained and found to be positive for IgG4. The patient was treated with oral steroids with partial resolution of the lesion. This is an interesting case of both histopathological adult onset xanthogranuloma (AOX) and IgG4-related orbital disease (IgG4-ROD). The early evidence suggests that the diagnosis of one of these disorders should point the physician to investigate for the presence of the other, especially if xanthogranulomatous disease is diagnosed first.


Assuntos
Doença Relacionada a Imunoglobulina G4 , Doenças Orbitárias , Xantomatose , Adulto , Granuloma , Humanos , Imunoglobulina G , Doença Relacionada a Imunoglobulina G4/diagnóstico , Doença Relacionada a Imunoglobulina G4/tratamento farmacológico , Doenças Orbitárias/diagnóstico , Doenças Orbitárias/tratamento farmacológico , Xantomatose/diagnóstico
9.
Opt Express ; 29(10): 14668-14681, 2021 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-33985184

RESUMO

Femtosecond laser pulse induced filamentation in atmosphere is susceptible to a number of input laser, focusing optics and medium characteristics. Filamentation of fs pulses in atmosphere is an intense propagation regime where the focusing geometry used to focus the fs laser pulses play an important role influencing the filament intensity and the associated supercontinuum. We identified different optical elements used for focusing the fs laser pulses leading to filamentation in air and classified them according to the induced aberrations. To clearly identify the role of aberrations, all the optical elements were taken to have same focal length. The subsequent filament structure and emissions from the filament were correlated with the aberrations induced by optical element revealed stark differences. The onset of the filamentation, its longitudinal intensity and the associated supercontinuum emission (SCE) have varied drastically with the aberrations induced by the focusing optics. A systematic study directed to choose and identify suitable optical elements according to the usage of the fs pulses for a specific filamentation regime is presented.

10.
Opt Express ; 29(7): 10395-10405, 2021 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-33820175

RESUMO

We present the spatial and temporal characterization of the copper (Cu) plasma produced by the femtosecond laser filaments. The filaments of various lengths and intensities were generated with the aid of three different focusing lenses. Further, the filamentation induced breakdown spectroscopy (FIBS) measurements were carried out for each filament at three different positions along the length of the filament. The filaments were spatially characterized by estimating the plasma temperature and electron density. Our investigation has demonstrated that the centre of the filament is the best to obtain a maximum signal. Both the spectral line intensity and their persistence time are highest for the center of the filament. The enhanced persistence and the scalability of the spectral line intensity tested across different focusing geometries can boost the application of this technique in various fields.

11.
Opt Lett ; 46(6): 1201-1204, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33720147

RESUMO

We report an enhanced supercontinuum generation (SCG) from a rare-earth (Pr3+) doped low bandgap zinc borate glass when excited with 60 fs pulses from a Ti-sapphire laser. The emission associated with the absorption bands due to Pr3+ doping (around 420-500 and 580-600 nm) is observed to assist the enhanced SCG.

12.
Catheter Cardiovasc Interv ; 98(5): 884-892, 2021 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-33325587

RESUMO

INTRODUCTION: The optimal approach to deal with severe coronary artery calcification (CAC) during percutaneous coronary intervention (PCI) remains ill-defined. METHODS: We conducted an electronic database search of all published studies comparing Orbital versus Rotational Atherectomy in patients undergoing PCI. RESULTS: Eight observational studies were included in the analysis. Overall, there were no significant differences in Major-adverse-cardiac-events/MACE (OR: 0.81, CI: 0.63-1.05, p = .11), myocardial-infarction/MI (OR: 0.75, CI: 0.56-1.00, p = .05), all-cause mortality (OR: 0.82, CI: 0.25-2.64, p = .73) or Target-vessel-revascularization/TVR (OR: 0.72, CI: 0.38-1.36, p = .31). However, OA was associated with lower long-term MACE (1-year), (OR: 0.66, CI: 0.44-0.99, p = .04), long-term TVR (OR: 0.40, CI: 0.18-0.89, p = .03), and short-term MI (in-hospital and 30-day) (OR: 0.64, CI: 0.44-0.94, p = .02). OA was associated with more coronary artery dissections (OR: 2.61, CI: 1.38-4.92, p = .003) and device-related coronary perforations (OR: 2.79, CI: 1.08-7.19, p = .03). There were no differences in cardiac tamponade (OR: 1.78, CI: 0.37-8.69, p = .47). OA was noted to have significantly lower fluoroscopy time (MD: -3.96 min, CI: -7.67, -0.25; p = .04) compared to RA. No significant difference was noted in terms of contrast volume between the two groups (OR: -4.35 ml, CI: -14.52, 23.22; p = .65). CONCLUSION: Although there was no difference in overall MACE, MI, all-cause mortality and TVR, OA was associated with lower long-term MACE and short-term MI. OA is associated with lower fluoroscopy time but higher rates of coronary artery dissection and coronary perforation.


Assuntos
Aterectomia Coronária , Doença da Artéria Coronariana , Estenose Coronária , Intervenção Coronária Percutânea , Calcificação Vascular , Aterectomia , Aterectomia Coronária/efeitos adversos , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/cirurgia , Humanos , Intervenção Coronária Percutânea/efeitos adversos , Estudos Retrospectivos , Fatores de Risco , Resultado do Tratamento , Calcificação Vascular/diagnóstico por imagem , Calcificação Vascular/terapia
13.
J Neurooncol ; 152(1): 55-65, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33389566

RESUMO

PURPOSE: Glioblastoma (GBM) is a highly invasive tumor. Despite advances in treatment modalities, tumor recurrence is common, seen mainly in the peritumoral brain zone (PBZ). We aimed to molecularly characterize PBZ, to understand the pathobiology of tumor recurrence. METHODS/PATIENTS: We selected eight differentially regulated genes from our previous transcriptome profiling study on tumor core and PBZ. Expression of selected genes were validated in GBM (tumor core and PBZ, n = 37) and control (n = 22) samples by real time quantitative polymerase chain reaction (qPCR). Serine protease inhibitor clade A, member 3 (SERPINA3) was selected for further functional characterization in vitro by gene knockdown approach in glioma cells. Its protein expression by immunohistochemistry (IHC) was correlated with other clinically relevant GBM markers, patient prognosis and tumor recurrence. RESULTS: The mRNA expression of selected genes from the microarray data validated in tumor core and PBZ and was similar to publicly available databases. SERPINA3 knock down in vitro showed decreased tumor cell proliferation, invasion, migration, transition to mesenchymal phenotype, stemness and radioresistance. SERPINA3 protein expression was higher in PBZ compared to tumor core and also was higher in older patients, IDH wild type and recurrent tumors. Finally, its expression showed positive correlation with poor patient prognosis. CONCLUSIONS: SERPINA3 expression contributes to aggressive GBM phenotype by regulating pro-tumorigenic actions in vitro and is associated with adverse clinical outcome.


Assuntos
Biomarcadores Tumorais/metabolismo , Neoplasias Encefálicas/patologia , Glioblastoma/patologia , Serpinas/metabolismo , Adulto , Idoso , Biomarcadores Tumorais/genética , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Proliferação de Células/genética , Transição Epitelial-Mesenquimal/genética , Feminino , Glioblastoma/genética , Glioblastoma/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica/genética , Recidiva Local de Neoplasia/genética , Recidiva Local de Neoplasia/metabolismo , Prognóstico , Tolerância a Radiação/genética , Serpinas/genética , Transcriptoma , Adulto Jovem
14.
Curr Cardiol Rep ; 23(4): 23, 2021 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-33655382

RESUMO

PURPOSE OF REVIEW: This article reviews the evidence on optimal medical therapy (OMT) versus coronary revascularization in patients with stable ischemic heart disease (SIHD) and advanced chronic kidney disease (CKD). RECENT FINDINGS: A post hoc analysis of the COURAGE trial in patients with SIHD and CKD showed no difference in freedom from angina, death, and nonfatal myocardial infarction (MI) between OMT and percutaneous intervention plus OMT compared with patients without CKD. The ISCHEMIA-CKD trial of 777 patients with advanced CKD revealed no difference in cumulative incidence of death or nonfatal MI at 3 years between OMT and revascularization but the composite of death or new dialysis was higher in the invasive arm. Additionally, there were no significant or sustained benefits in related to angina-related health status in invasive versus conservative strategy. An initial revascularization strategy does not reduce mortality or MI or relieve angina symptoms in patients with SIHD and advanced CKD.


Assuntos
Doença da Artéria Coronariana , Isquemia Miocárdica , Intervenção Coronária Percutânea , Insuficiência Renal Crônica , Angina Pectoris , Ponte de Artéria Coronária , Humanos , Isquemia Miocárdica/complicações , Isquemia Miocárdica/terapia , Insuficiência Renal Crônica/complicações , Resultado do Tratamento
15.
Fish Physiol Biochem ; 47(5): 1687-1696, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34467468

RESUMO

Three trials were conducted to evaluate the performances of red snapper, Lutjanus campechanus, in low salinities. The median lethal concentration (96 h LC50) of salinity was determined by trimmed Spearman-Karber method using survival data of fish (18.9 ± 0.2 g) collected after 96 h from acclimation to 2, 4, 8, and 32 ppt salinities in 800 L tanks (n = 3), while the serum osmolality of fish (74.1 ± 3.9 g) was determined after 48 h from acclimation to 6, 8, 16, 24, and 32 ppt salinities in 150 L tanks (n = 3). The growth trial was conducted for 6 weeks in 800 L tanks to determine the growth and survival of fish (18.8 ± 0.2 g) at 8 ppt salinity compared to the control (32 ppt salinity). At the conclusion, the isosmotic point of fish was estimated as 357.2 mmol/kg (correspond to 11.0 ppt salinity), while the 96 h LC50 was estimated as 5.65 ppt salinity. No significant differences were noted for survival and FCR of fish reared in 8 and 32 ppt salinities. However, growth was significantly lower in fish reared in 8 ppt salinity compared to the fish reared in 32 ppt salinity. The reduced growth could be, at least partially, due to the increased osmoregulatory energy expenditure at lower salinities.


Assuntos
Osmorregulação , Perciformes , Salinidade , Animais , Peixes , Alimentos Marinhos
16.
Ergonomics ; 64(6): 744-754, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33320790

RESUMO

The vibration discomfort to the human body in semi-supine posture is currently evaluated as per ISO 2631-1, although it is recommended for sitting, standing and recumbent posture. The present study investigated the frequency-dependence of subjective responses of semi-supine humans to vertical vibration (0.5-1.5 m s-2 r.m.s.) across the frequency range 2.0-16.0 Hz. The subjects (14 males) judged the discomfort caused due to sinusoidal vibration using a modified absolute magnitude estimation method. The significant variation of rate of growth of discomfort across the frequency spectra caused the shape of equivalent comfort contour to vary with the vibration magnitude. The equivalent comfort contours illustrated significant discomfort between 8.0 and 10.0 Hz. Moreover, for frequencies above 10.0 Hz, substantial vibration acceleration was required to cause discomfort of the same intensity, implying that the frequency dependence of semi-supine posture is distinct from other postures. The frequency weighting obtained for semi-supine posture suggested that the discomfort estimation based on ISO 2631-1 was relatively accurate though conservative. Practitioner Summary: The discomfort caused by vertical vibration to the human in semi-supine posture was quite different from other postures. The present study provided the frequency-dependence of vibration discomfort for humans in semi-supine posture. Further, it investigated the suitability of frequency weightings defined in ISO 2631-1 for the acceleration measurements. Abbreviations: ISO: International Organization for Standardization; BS: British Standard; NASA: National Aeronautics and Space Administration; BMI: body mass index; AME: absolute magnitude estimation.


Assuntos
Corpo Humano , Vibração , Aceleração , Humanos , Masculino , Postura , Postura Sentada , Vibração/efeitos adversos
17.
Proc Natl Acad Sci U S A ; 114(8): E1413-E1421, 2017 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-28174275

RESUMO

Fibroblasts are a main player in the tumor-inhibitory microenvironment. Upon tumor initiation and progression, fibroblasts can lose their tumor-inhibitory capacity and promote tumor growth. The molecular mechanisms that underlie this switch have not been defined completely. Previously, we identified four proteins overexpressed in cancer-associated fibroblasts and linked to Rho GTPase signaling. Here, we show that knocking out the Ras homolog family member A (RhoA) gene in normal fibroblasts decreased their tumor-inhibitory capacity, as judged by neighbor suppression in vitro and accompanied by promotion of tumor growth in vivo. This also induced PC3 cancer cell motility and increased colony size in 2D cultures. RhoA knockout in fibroblasts induced vimentin intermediate filament reorganization, accompanied by reduced contractile force and increased stiffness of cells. There was also loss of wide F-actin stress fibers and large focal adhesions. In addition, we observed a significant loss of α-smooth muscle actin, which indicates a difference between RhoA knockout fibroblasts and classic cancer-associated fibroblasts. In 3D collagen matrix, RhoA knockout reduced fibroblast branching and meshwork formation and resulted in more compactly clustered tumor-cell colonies in coculture with PC3 cells, which might boost tumor stem-like properties. Coculturing RhoA knockout fibroblasts and PC3 cells induced expression of proinflammatory genes in both. Inflammatory mediators may induce tumor cell stemness. Network enrichment analysis of transcriptomic changes, however, revealed that the Rho signaling pathway per se was significantly triggered only after coculturing with tumor cells. Taken together, our findings in vivo and in vitro indicate that Rho signaling governs the inhibitory effects by fibroblasts on tumor-cell growth.


Assuntos
Fibroblastos Associados a Câncer/metabolismo , Proliferação de Células/fisiologia , Neoplasias/metabolismo , Proteína rhoA de Ligação ao GTP/metabolismo , Actinas/metabolismo , Animais , Linhagem Celular Tumoral , Movimento Celular/fisiologia , Células Cultivadas , Colágeno/metabolismo , Feminino , Adesões Focais/metabolismo , Células HEK293 , Humanos , Camundongos , Camundongos SCID , Transdução de Sinais/fisiologia , Fibras de Estresse/metabolismo , Quinases Associadas a rho/metabolismo
18.
Curr Cardiol Rep ; 22(4): 16, 2020 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-32036460

RESUMO

PURPOSE OF REVIEW: To review the clinical evidence on the use of percutaneous coronary intervention (PCI) revascularization options in left main (LM) disease in comparison with coronary artery bypass graft (CABG). Coronary artery disease (CAD) involving the LM is associated with high morbidity and mortality. Though CABG remains the gold standard for complex CAD involving the LM artery, recent trials have shown a trend towards non-inferiority of the LM PCI when compared with CABG in certain subset of patients. RECENT FINDINGS: Two recent major randomized trials compared the outcomes of PCI versus CABG in the LM and multi-vessel disease with LM involvement. The NOBLE trial included patients with all range of Synergy Between Percutaneous Coronary Intervention With TAXUS and Cardiac Surgery (SYNTAX) scores and utilized biolimus drug-eluting stent (DES). The trial concluded that MACCE (major adverse cardiac and cerebrovascular event) was significantly higher with PCI (28%) when compared with CABG (18%) but overall stroke and motility were not different. EXCEL trial evaluated the same treatment option in low to intermediate SYNTAX score population with third-generation everolimus DES platform as PCI option. Results showed no significant differences in the composite primary endpoints of death, stroke, and myocardial infarction (MI) at the end of 30 days (22% versus 19.2%, p = 0.13), although repeat revascularization was higher in PCI group (16.9% versus 10%). Recent evidence suggests that PCI is an acceptable alternative to treat symptomatic LM stenosis in select group of patients. In low to medium SYNTAX score, particularly in patients without diabetes mellitus, PCI remains a viable option. Future trials focusing on evaluating subset of patients who would benefit from one particular revascularization option in comparison with other is warranted.


Assuntos
Doença da Artéria Coronariana/cirurgia , Stents Farmacológicos , Intervenção Coronária Percutânea , Ponte de Artéria Coronária , Humanos , Resultado do Tratamento
19.
Curr Cardiol Rep ; 22(4): 17, 2020 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-32036467

RESUMO

PURPOSE OF REVIEW: Fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) have emerged as the invasive diagnostic tools of choice for hemodynamic assessment of the severity of CAD (coronary artery disease). We sought to comprehensively review the evidence on the utility of hemodynamic assessment of the coronary stenoses after percutaneous coronary intervention (PCI) using FFR/iFR, mechanisms of positive post-PCI iFR/FFR, and the clinical impact of significant residual ischemia. RECENT FINDINGS: The evidence on the utility of the post-PCI hemodynamic assessment has accumulated over the last few years. The post hoc analysis from the FAME 1 and FAME 2 data shows that higher post-PCI FFR is associated with better symptomatic improvement and lower event rate with larger increase in delta FFR (∆ FFR: post-PCI FFR - pre-PCI FFR). Unlike pre-PCI FFR, a consensus has not been established on the optimal value of post-PCI FFR, though multiple studies point toward better clinical outcomes with higher post-PCI FFR and larger ∆ FFR. Visual assessment of adequate stent apposition by coronary angiography is insufficient in evaluating for residual ischemia. The hemodynamic evaluation of residual ischemia by post-PCI FFR/iFR yields clinically relevant data and allows for appropriate post PCI optimization.


Assuntos
Estenose Coronária/cirurgia , Procedimentos Cirúrgicos Eletivos/métodos , Reserva Fracionada de Fluxo Miocárdico/fisiologia , Intervenção Coronária Percutânea/métodos , Cateterismo Cardíaco , Angiografia Coronária/métodos , Doença da Artéria Coronariana , Estenose Coronária/diagnóstico por imagem , Humanos , Valor Preditivo dos Testes , Resultado do Tratamento
20.
Artigo em Inglês | MEDLINE | ID: mdl-31348112

RESUMO

PURPOSE: To review the clinical radiographic and histopathologic findings associated with orbital glial heterotopia. METHODS: A literature search in PubMed and Scopus was performed to include all articles published in English between 1980 and January 1, 2019. A case series including 29 case reports of 29 patients, as well as the authors' 2 cases, were considered in the literature review. RESULTS: The majority of the cases had onset of symptoms (86%) and age at presentation (71%) before 5 years of age. The most common presenting symptoms and signs were swelling (45%), strabismus (32%), and proptosis (26%). The most common lesion locations described were inferolateral (19%) or primarily posterior orbital or apical (19%). The most common findings associated with orbital glial heterotopia were microphthalmia (10%) and anophthalmia (6%); however, the majority did not have systemic abnormalities (71%). The most common imaging modality was CT scan (71%). Diagnosis was made with histologic analysis in all cases, and confirmed after subtotal resection (35%), total resection (39%), or incisional biopsy (26%). The majority of the cases report no growth on repeat imaging, with only 3 reports of recurrence. CONCLUSIONS: Glial heterotopia in the orbit is a rare clinical entity most commonly presenting in children. We present 2 cases of orbital glial heterotopia in adults, with a literature on these lesions in both the pediatric and adult populations. Surgeons and pathologists should be aware of this atypical presentation in adulthood. Biopsy is required for diagnosis but is not without risk. Prognosis is generally favorable.Orbital glial heterotopia, commonly considered a rare congenital lesion generally presenting in children, may first become symptomatic in adulthood. Biopsy is required for diagnosis, with symptoms and prognosis dependent on location and growth of the lesion.


Assuntos
Exoftalmia , Doenças Nasais , Adulto , Biópsia , Criança , Pré-Escolar , Humanos , Órbita , Tomografia Computadorizada por Raios X
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