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1.
Molecules ; 29(15)2024 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-39124895

RESUMO

In contrast to the traditional analysis of molecules using local mode behavior, where the degree of locality is given through a function in terms of Morse potential parameters, new criteria for locality/normality (LN) suitable for application to any molecular system are proposed. The approach is based on analysis of the connection between the algebraic normal and local mode representations. It is shown that both descriptions are equivalent as long as the polyad (total number of quanta) in the local representation is not conserved. The constraint of a local polyad conservation naturally provides a criterion for assigning an LN degree in quantitative form, without an analogue in configuration space. The correlation between the different parameters reveals the physical properties of molecules. A clear connection between the LN degree (based on the fundamentals) and spectroscopic properties is also presented, suggesting a promising approach for identifying mixtures of isotopologues.

2.
Sensors (Basel) ; 22(23)2022 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-36502135

RESUMO

Waste heat dissipated in the exhaust system of a combustion engine represents a major source of energy to be recovered and converted into useful work. The Waste Heat Recovery System (WHRS) based in an Organic Rankine Cycle (ORC) is an approach for recovering energy from heat sources, achieving a significant reduction in fuel consumption and, as a result, exhaust emissions. This paper studies pressure drop in an ORC shell-and-tubes boiler for a WHRS implementation experimentally and with computational simulations based on a 1-dimensional heat transfer model coupled with 3D calculations. An experimental database is developed, using ethanol in a pressure range of 10-15 absolute bar as working fluid, with mass fluxes inside the tubes in the range of 349.31 kg/s-m2 and 523.97 kg/s-m2, and inlet temperatures in the range of 60 °C and 80 °C. Thus, the friction factor of different regions of the boiler were estimated using both CFD simulations, experimental data, and bibliographic correlations. Simulations of operating points and the results of the experimental test bench showed good agreement in pressure drop results, with a mean absolute error of 15.47%, without a significant increment in the computational cost.


Assuntos
Temperatura Alta , Temperatura
3.
Lasers Med Sci ; 36(7): 1515-1525, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33400010

RESUMO

This study aimed to investigate the effects of administering photobiomodulation therapy (PBM) with bovine bone matrix on critical size defects in rats. Seventy-two adult male rats (albinus, Wistar), 90 days old, were used. Defect of 5 mm in diameter was made in their calvaria. The animals were divided into 4 groups: C-blood clot, B-Bio-Oss®, L-PBM, B+L-Bio-Oss®+PBM. Each group has been subdivided into 07, 30, and 60 days of observation. For PBM, a low GaAlAs energy of 660 nm was irradiated, total energy density of 45 J/cm2 . PBM was conducted in a trans-surgical form once only. For immunohistochemistry, a semi-quantitative analysis was made of expression of osteoprotegerin (OPG), nuclear kappa B-factor ligand receptor activator (RANKL), and tartrate-resistant acid phosphatase (TRAP). All histomorphometric data were statistically analyzed by ANOVA and Tukey test, significance level of 5%. The groups that showed the highest proportion of neoformation were L (0.39% ± 0.13) and C (0.37% ± 0.97), but groups B and B+L had larger defect size (C-1.75 mm2 ± 0.40, B-3.02 mm2 ± 0.63, L-2.45 mm2 ± 0.53, B+L-3.23 mm2 ± 1.01). In immunohistochemistry, groups B and B+L had higher immunostaining scores for OPG and RANKL at 60 days, and TRAP immunostaining increased in all groups at 30 days, but group L was the only one to present specimens with score 0. Although, at 60 days, groups L and C presented the highest proportion of bone neoformation, at 30 days group B+L had more than twice as much bone neoformation as group B, the choice of treatment application should depend on the aim of the treatment.


Assuntos
Terapia com Luz de Baixa Intensidade , Animais , Bovinos , Masculino , Minerais , Osteoprotegerina , Ratos , Ratos Wistar , Crânio
4.
Sensors (Basel) ; 19(7)2019 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-30970534

RESUMO

Waste heat dissipated in the exhaust system in a combustion engine represents a major source of energy to be recovered and converted into useful work. A waste heat recovery system (WHRS) based on an Organic Rankine Cycle (ORC) is a promising approach, and it gained interest in the last few years in an automotive industry interested in reducing fuel consumption and exhaust emissions. Understanding the thermodynamic response of the boiler employed in an ORC plays an important role in steam cycle performance prediction and control system design. The aim of this study is, therefore, to present a methodology to study these devices by means of pattern recognition with infrared thermography. In addition, the experimental test bench and its operating conditions are described. The methodology proposed identifies the wall coordinates, traces the paths, and tracks the wall temperature along them in a way that can be exported for subsequent post-processing and analysis. As for the results, through the wall temperature paths on both sides (exhaust gas and working fluid), it was possible to quantitatively estimate the temperature evolution along the boiler and, in particular, the beginning and end of evaporation.

5.
Nano Lett ; 17(11): 6878-6885, 2017 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-28968124

RESUMO

Two-dimensional electron gases (2DEGs) formed at the interface between two oxide insulators provide a rich platform for the next generation of electronic devices. However, their high carrier density makes it rather challenging to control the interface properties under a low electric field through a dielectric solid insulator, that is, in the configuration of conventional field-effect transistors. To surpass this long-standing limit, we used ionic liquids as the dielectric layer for electrostatic gating of oxide interfaces in an electric double layer transistor (EDLT) configuration. Herein, we reported giant tunability of the physical properties of 2DEGs at the spinel/perovskite interface of γ-Al2O3/SrTiO3 (GAO/STO). By modulating the carrier density thus the band filling with ionic-liquid gating, the system experiences a Lifshitz transition at a critical carrier density of 3.0 × 1013 cm-2, where a remarkably strong enhancement of Rashba spin-orbit interaction and an emergence of Kondo effect at low temperatures are observed. Moreover, as the carrier concentration depletes with decreasing gating voltage, the electron mobility is enhanced by more than 6 times in magnitude, leading to the observation of clear quantum oscillations. The great tunability of GAO/STO interface by EDLT gating not only shows promise for design of oxide devices with on-demand properties but also sheds new light on the electronic structure of 2DEG at the nonisostructural spinel/perovskite interface.

6.
Heliyon ; 9(7): e17861, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37519737

RESUMO

The integration of alternative energy sources as a replacement for fossil fuels across various industrial sectors, including power generation, emergency systems, or marine applications, is uncertain. As a result, the utilization of traditional fuels is not anticipated to be fully phased out in the near future. To address this, new technologies, such as those that employ oxidising atmospheres, have been explored as a means to enhance the pollution control capabilities of existing technologies, as the Exhaust Gas Recirculation (EGR) system. In this regard, the present study has assessed the efficacy of ozone atmosphere exposure in mitigating the formation of undesired fouling deposits within the system, with the aim of facilitating more efficient operation of EGR devices and extending their service life. To this end, dry soot samples have been exposed to various ozone atmospheres at different temperatures and ozone concentrations through the utilization of an experimental test bench. The oxidation potential of these atmospheres has been evaluated through the analysis of the deposit mass loss. Likewise, confocal microscopy techniques have been employed to obtain the 3D topography of the fouling samples before and after the ozone treatment, allowing the assessment of the deposit thickness reduction, as well as the surface roughness variation. Additionally, thermogravimetric analysis has been conducted to examine the effects of the oxidation processes on fouling samples composition. The findings of this study have revealed that ozone atmospheres have been effective in reducing deposit mass at ozone treatment temperatures above 100 °C. The reduction in mass has reached 78.5% and 91.8% with treatment temperature of 140 °C with ozone concentrations of 30 gO3/m³ and 50 gO3/m³, respectively. It has also been established that treatment conditions with ozone concentrations of 30 gO3/m³ and 50 gO3/m³ are effective in reducing the thickness of deposits even at intermediate treatment temperatures, resulting in a thickness reduction of 78.6% and 81.1% at 80 °C, respectively. Additionally, it has been observed that the ozone exposure leads to the increase in the proportion of volatile material within the deposit.

7.
J Biomed Mater Res B Appl Biomater ; 111(11): 1956-1965, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37482895

RESUMO

This study aimed to evaluate the Carbon Fiber obtained from PAN textile and cotton fiber in their different forms of presentation: non-activated carbon fiber felt (NACFF), activated carbon fiber felt (ACFF), silver activated carbon fiber felt (Ag-ACFF), and activated carbon fiber tissue (ACFT), to obtain scaffolds as a potential material with properties related to the synthetic bone graft. Characterization tests performed: surface wettability, traction, swelling, and in vivo tests: evaluation of the inflammatory response by implanting the materials in the subcutaneous tissue of 14 Wistar rats, evaluation of collagen fibers by picrosirius red staining and assessment of toxicity in the following organs: heart, spleen, liver, and kidney. In the wettability test, NACFF and ACFT were hydrophobic (θ124° and 114°), ACFF and Ag-ACFF were hydrophilic. For maximum stress, ACFF was more resistant (2.983 ± 1.059) p < .05. In the swelling test, the Ag-ACFF and ACFF groups showed the highest absorption percentage for the PBS solution and distilled water (p < .001). The organs showed no signs of acute systemic toxicity. The implant regions showed mild to moderate inflammatory infiltrate at 7 and 21 days. Only the ACFT group did not show the maturation of type I collagen fibers in 21 days. Through the conducted analyses, the ACFT shows little potential to be indicated as a possible scaffold. Therefore NACFF, ACFF, and Ag-ACFF have the potential to be considered scaffolds due to the following characteristics presented: good absorption rate, hydrophilicity, and non-toxic.

8.
Nat Commun ; 14(1): 358, 2023 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-36690620

RESUMO

The 2021 volcanic eruption at La Palma, Canary Islands, was the island's most voluminous historical eruption. Little is known about this volcano's feeding system. During the eruption, seismicity was distributed in two clusters at ~10-14 km and ~33-39 km depth, separated by an aseismic zone. This gap coincides with the location of weak seismic swarms in 2017-2021 and where petrological data have implied pre-eruptive magma storage. Here we use seismological methods to understand the seismic response to magma transfer, with 8,488 hypocentral relocations resolving small-scale seismogenic structures, and 156 moment tensors identifying stress heterogeneities and principal axes flips. Results suggest a long-lasting preparatory stage with the progressive destabilisation of an intermediate, mushy reservoir, and a co-eruptive stage with seismicity controlled by the drainage and interplay of two localised reservoirs. Our study provides new insights into the plumbing system that will improve the monitoring of future eruptions in the island.


Assuntos
Exantema , Engenharia Sanitária , Humanos , Espanha , Heterogeneidade Genética , Resolução de Problemas
9.
Comput Methods Biomech Biomed Engin ; 25(6): 641-655, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-34459293

RESUMO

The most common solution for the regeneration or replacement of damaged bones is the implantation of prostheses comprising ceramic or metallic materials. However, these implants are known to cause problems such as post-operative infections, collapse of the prosthesis, and lack of osseointegration. Consequently, bone tissue engineering was established because of the limitations of such implants. Osteogenic implants offer promising solutions for bone regeneration; however, three-dimensional scaffolds should be used as supportive structures. It is challenging to correctly design these structures and their compositions or properties to provide a microenvironment that promotes tissue regeneration and expedites bone formation. Computational fluid dynamics can be used to model the main phenomena that occur in bioreactors, such as cell metabolism, nutrient transport, and cell culture growth, or to model the influence of several key mechanisms related to the fluid medium, in particular, the wall shear stress. In this work, a new numerical bone cell growth model was developed, which considered the oxygen and nutrient consumption as well as the wall shear stress effect on cell proliferation. The model was implemented using 35 three-dimensional scaffolds of different porosities, and the effect of the main geometrical parameters involved in each scaffold type was analysed. The porosity plays an important role, however, a similar porosity did not guarantee similar shear stress or cell growth among the scaffolds. Randomised trabecular scaffolds, that more closely resembled trabecular bone, showed the highest cell growth values, so these are the best candidates for cell growth in a bioreactor.


Assuntos
Osteócitos , Alicerces Teciduais , Osso e Ossos , Porosidade , Engenharia Tecidual/métodos , Alicerces Teciduais/química
10.
Polymers (Basel) ; 13(4)2021 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-33671706

RESUMO

Lignin-based polyols (LBPs) with controlled microstructure were obtained by cationic ring opening polymerization (CROP) of oxiranes in an organosolv lignin (OL) tetrahydrofuran (THF) solution. The control on the microstructure and consequently on the properties of the LBPs such as hydroxyl number, average molecular weight, melting, crystallization and decomposition temperatures, are crucial to determine the performance and application of the derived-products. The influence of key parameters, for example, molar ratio between the oxirane and the hydroxyl groups content in OLO, initial OL concentration in THF, temperature, specific flow rate and oxirane nature has been investigated. LBPs with hydroxyl numbers from 35 to 217 mg KOH/g, apparent average Mw between 5517 and 52,900 g/mol and melting temperatures from -8.4 to 18.4 °C were obtained. The CROP procedure allows obtaining of tailor-made LBPs for specific applications in a very simple way, opening the way to introduce LBPs as a solid alternative to substitute currently used fossil-based polyols.

11.
MEDICC Rev ; 23(1): 64-71, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33780425

RESUMO

INTRODUCTION: With a global adult prevalence of 24%, non-alcoholic fatty liver disease is a global health problem that parallels the worldwide increase of obesity. Its frequency, clinical characteristics and related diseases in Cuba remain unknown. OBJECTIVE: Describe the clinical characteristics, comorbidities and personal habits of patients with non-alcoholic fatty liver disease who are being treated in secondary and tertiary health facilities in seven Cuban provinces. METHODS: A cross-sectional, multicenter study was carried out in 6601 adults seen at gastroenterology outpatient clinics of nine hospitals in seven Cuban provinces from September 2018 through May 2019. Non-alcoholic fatty liver disease was diagnosed by abdominal ultrasound. The study included 1070 patients who met the diagnostic and study criteria and agreed to participate. Their personal habits and anthropometric and clinical characteristics, comorbidities and other aspects of their medical histories were recorded. RESULTS: Of the 1070 participants, 60.7% (649) were women. Participants' average age was 54.5 years and average body mass index was 30.5 kg/m2. A total of 397 (37.1%) were overweight and 574 (53.6%) were obese, 945 (88.3%) led a sedentary lifestyle, 564 (52.7%) had high blood pressure, 406 (37.9%) had lipid disorders and 301 (28.1%) were diabetic. While 484 (45.2%) of patients were asymptomatic, the most frequent clinical signs and symptoms were fatigue (262; 24.5%), dyspepsia (209; 19.5%), abdominal pain (306; 28.5%) and hepatomegaly (189; 17.7%). Liver cirrhosis was present in 37 (3.5%) patients at the time of diagnosis. Family history of type 2 diabetes mellitus and obesity were identified in 391 (36.5%) and 279 (26.1%) of participants, respectively. CONCLUSIONS: Prevalence of non-alcoholic fatty liver disease in these Cuban patients coincides with that reported in the Caribbean region, which has high levels of obesity, overweight and sedentary lifestyles. Most were asymptomatic, female or had metabolism-related comorbidities such as high blood pressure, type 2 diabetes mellitus and dyslipidemia.


Assuntos
Hepatopatia Gordurosa não Alcoólica/epidemiologia , Índice de Massa Corporal , Estudos Transversais , Cuba/epidemiologia , Diabetes Mellitus Tipo 2/epidemiologia , Dislipidemias/epidemiologia , Feminino , Humanos , Hipertensão/epidemiologia , Masculino , Pessoa de Meia-Idade , Prevalência , Fatores de Risco
12.
J Am Chem Soc ; 132(18): 6463-73, 2010 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-20405840

RESUMO

A series of bulky phosphines containing substituted biphenyl, 2-methylnaphthyl, or 2,7-di-tert-butyl-9,9-dimethylxanthene moiety were prepared. They were used in the preparation of new monophosphine-palladium(0)-dvds complexes, which were employed as catalysts for the selective telomerization of 1,3-butadiene with methanol to obtain 1-methoxyocta-2,7-diene (1-MOD), the key intermediate in the Dow 1-octene process. Several ligands showed improved selectivity and yield compared to that of the benchmark ligand PPh(3). Especially 2,7-di-tert-butyl-9,9-dimethylxanthen-4-yl-diphenylphosphine (4, "mono-xantphos") stands out as an excellent ligand in terms of yield, selectivity, and stability.

13.
J Immunol ; 181(9): 6625-34, 2008 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-18941253

RESUMO

1E10 mAb is an anti-Id murine mAb (Ab2 mAb) specific for an Ab1 mAb that reacts with NeuGc-containing gangliosides, sulfatides, and Ags expressed in some human tumors. In preclinical studies, this Ab2 Ab was able to mimic NeuGc-containing gangliosides only in animals lacking expression of these Ags in normal tissues. In this study, we report on the immune responses elicited in 20 non-small cell lung cancer patients treated with 1 mg of aluminum hydroxide-precipitated 1E10 mAb. In the hyperimmune sera from 16 of 20 patients, a strong specific Ab response of both IgM and IgG isotypes against NeuGcGM3 ganglioside was observed. Patient immune sera were able to induce complement-independent cell death of NeuGcGM3-expressing X63 murine myeloma target cells. Significant immunoreactivity to NeuGcGM3 was still detected after the complete abrogation of the reactivity against 1E10 mAb by the adsorption of patient sera with this Ab. We hypothesize that Id(-)Ag(+) Abs could reflect the activation of an autologous idiotypic cascade into the patients. Both Id(+)Ag(+) and Id(-)Ag(+) fractions were separated by affinity chromatography and characterized. Although IgG isotype Abs were found in both fractions, IgM isotype Abs were found only in the Id(-)Ag(+) fraction. Both Id(+)Ag(+) and Id(-)Ag(+) Abs were able to specifically recognize and induce cell death in NeuGcGM3-expressing X63 myeloma target cells. Patients that developed IgG and/or IgM Abs against NeuGcGM3 showed longer median survival times.


Assuntos
Anticorpos Anti-Idiotípicos/biossíntese , Anticorpos Monoclonais/uso terapêutico , Vacinas Anticâncer/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/imunologia , Carcinoma Pulmonar de Células não Pequenas/terapia , Gangliosídeo G(M3)/análogos & derivados , Neoplasias Pulmonares/imunologia , Neoplasias Pulmonares/terapia , Animais , Anticorpos Anti-Idiotípicos/administração & dosagem , Anticorpos Anti-Idiotípicos/uso terapêutico , Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais/toxicidade , Especificidade de Anticorpos , Vacinas Anticâncer/administração & dosagem , Vacinas Anticâncer/efeitos adversos , Vacinas Anticâncer/imunologia , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma Pulmonar de Células não Pequenas/patologia , Morte Celular/imunologia , Linhagem Celular Tumoral , Cães , Relação Dose-Resposta Imunológica , Gangliosídeo G(M3)/biossíntese , Gangliosídeo G(M3)/sangue , Gangliosídeo G(M3)/genética , Gangliosídeo G(M3)/imunologia , Cavalos , Humanos , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Células Tumorais Cultivadas
14.
Rev Panam Salud Publica ; 27(2): 117-24, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20339615

RESUMO

OBJECTIVES: To compare the safety and immunogenicity of a booster dose of a fully liquid diphtheria-tetanus-whole cell pertussis-hepatitis B-Haemophilus influenzae type b (DTPw-HepB-Hib) vaccine to the separate administration of commercially available DTPw and Hib vaccines in healthy toddlers. METHODS: An open-label, randomized, parallel-group, Phase III study conducted at six centers in San Salvador, El Salvador, during February-June 2006. Toddlers (15-24 months of age) were eligible to participate if they had received primary immunization at 2, 4, and 6 months of age with a commercial DTPw-HepB/Hib vaccine requiring reconstitution. Participants received either one booster dose of DTPw-HepB-Hib fully liquid vaccine or DTPw and Hib vaccines administered separately. Blood samples were taken immediately prior to and at 1 month post-vaccination. For a 5-day period following vaccination, solicited adverse events were collected in subject diaries and assessed. RESULTS: The combined DTPw-HepB-Hib fully liquid vaccine was non-inferior to the separately administered DTPw and Hib vaccines, in terms of seroprotection/seroconversion rates for all antigens evaluated. The combination vaccine elicited a strong booster response as demonstrated by a large increase in antibodies against all vaccine antigens. The geometric mean concentrations (GMCs) of all antibodies in the DTPw-HepB-Hib group exceeded the seroprotection/seroconversion thresholds by very large margins, although for some antigens they were somewhat lower than the corresponding titers in the comparator group. With the combination vaccine, considerably fewer solicited local and systemic adverse events, such as fever and irritability, were reported than with the comparator vaccines. CONCLUSIONS: This study demonstrates that the fully liquid combined DTPw-HepB-Hib vaccine is highly immunogenic and has a favorable safety profile when given as a booster vaccination to toddlers who have received a primary vaccination course with a different pentavalent vaccine that requires reconstitution.


Assuntos
Vacina contra Difteria, Tétano e Coqueluche/administração & dosagem , Vacina contra Difteria, Tétano e Coqueluche/imunologia , Vacinas Anti-Haemophilus/administração & dosagem , Vacinas Anti-Haemophilus/imunologia , Vacinas contra Hepatite B/administração & dosagem , Vacinas contra Hepatite B/imunologia , Imunização Secundária , El Salvador , Feminino , Humanos , Lactente , Masculino , Vacinas Combinadas
15.
Polymers (Basel) ; 12(5)2020 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-32408686

RESUMO

A latex of amphiphilic star polymer particles, functionalized in the hydrophobic core with nixantphos and containing P(MAA-co-PEOMA) linear chains in the hydrophilic shell (nixantphos-functionalized core-crosslinked micelles, or nixantphos@CCM), has been prepared in a one-pot three-step convergent synthesis using reversible addition-fragmentation chain transfer (RAFT) polymerization in water. The synthesis involves polymerization-induced self-assembly (PISA) in the second step and chain crosslinking with di(ethylene glycol) dimethacrylate (DEGDMA) in the final step. The core consists of a functionalized polystyrene, obtained by incorporation of a new nixantphos-functionalized styrene monomer (nixantphos-styrene), which is limited to 1 mol%. The nixantphos-styrene monomer was synthesized in one step by nucleophilic substitution of the chloride of 4-chloromethylstyrene by deprotonated nixantphos in DMF at 60 °C, without interference of either phosphine attack or self-induced styrene polymerization. The polymer particles, after loading with the [Rh(acac)(CO)2] precatalyst to yield Rh-nixantphos@CCM, function as catalytic nanoreactors under aqueous biphasic conditions for the hydroformylation of 1-octene to yield n-nonanal selectively, with no significant amounts of the branched product 2-methyl-octanal.

16.
RSC Adv ; 10(31): 18487-18495, 2020 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-35517184

RESUMO

Monolithic silicon carbide supported ionic liquid-phase (SILP) Rh-catalysts have very recently been introduced for gas-phase hydroformylation as an important step toward industrial upscaling. This study investigates the monolithic catalyst system in combination with different impregnation procedures with non-invasive magnetic resonance imaging (MRI). The findings were supported by X-ray microtomography (micro-CT) data of the monolithic pore structure and a catalytic performance test of the catalyst system for 1-butene gas-phase hydroformylation. MRI confirmed a homogeneous impregnation of the liquid phase throughout the full cross-section of the cylindrical monoliths. Consistent impregnations from one side to the other of the monoliths were achieved with a stabilizer in the system that helped preventing inhomogeneous rim formation. External influences relevant for industrial application, such as long-term storage and temperature exposure, did not affect the homogeneous liquid-phase distribution of the catalyst. The work elucidates important parameters to improve liquid-phase catalyst impregnation to obtain efficient monolithic catalysts for industrial exploitation in gas-phase hydroformylation as well as other important industrial processes.

17.
Comput Methods Biomech Biomed Engin ; 22(5): 547-566, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30773045

RESUMO

The clearance of mucus through coughing is a complex, multiphase process, which is affected principally by mucus viscosity and airflow velocity; however, it is also critically affected by the thickness of the two layers of mucus-the serous and gel layers-and oscillation level. The present study examines the effects of the latter parameters more closely. To do so, the mucus clearance process is simulated with a transient 3D volume of fluid (VOF) multiphase model in ANSYS Fluent. The model includes mucus' bilayer properties and a wide range of boundary conditions were tested. The model was analysed in both a straight tube and a realistic trachea. Ultimately, the model was able to both capture air-mucus interface wave evolution and predict the overall behaviour of the clearance process. The results were consistent with experimental clearance data and numerical airflow simulations, which indicates our methodology is appropriate for future studies. Ultimately, the mere presence of the serous layer was found to increase mucus clearance by more than 15 percent. An oscillating flow enhanced clearance by up to 5 percent. Interestingly, interface wave steepness was found to be inversely correlated with mucus thickness, but directly with mucus velocity, which suggests it will be an interesting parameter for further study.


Assuntos
Simulação por Computador , Hidrodinâmica , Depuração Mucociliar , Modelos Biológicos , Muco/metabolismo , Reprodutibilidade dos Testes , Fatores de Tempo , Traqueia/fisiologia , Viscosidade
18.
J Mol Model ; 25(9): 264, 2019 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-31432261

RESUMO

Electronic and spectroscopic properties of tetracationic 5,10,15,20-tetrakis(1-methyl-4-pyridyl)-21H,23H-porphyrin (TMPyP) were investigated in the framework of the density functional theory (DFT). Modeling of implicit solvent, charge effects, and medium acidity were performed and compared with experimental results. Various hybrid exchange correlation functionals in the Kohn-Sham Scheme of the DFT were employed and various porphyrin models were constructed, simulating different environmental conditions. Since porphyrins present several technological applications with a plethora of interacting systems and the optical spectra profiles are often used to characterize these macrocyclic compounds, the study performed here aims to stablish a correct description of the UV-Vis spectrum. These results allowed to reproduce, both qualitatively as well as quantitatively, the Soret band of the TMPyP.

19.
J Immunol Methods ; 339(2): 220-7, 2008 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-18854189

RESUMO

Antibodies capable of recognizing key molecular targets isolated e.g. by phage display technology have been used in the pursuit of new and improved therapies for prevalent human diseases. These approaches often take advantage of non-immunogenic antibody fragments to achieve specific toxin-, radioactivity- or effector-domain delivery. There is now a growing interest in using anti-idiotypic antibodies or other antigen mimics to induce potent immune responses against antigen structures in question. We have earlier reported on the functional rescue of antibodies that are active when fused to the phage, but inactive as soluble protein [Jensen, K.B., Larsen, M., Pedersen, J.S., Christensen, P.A., Alvarez-Vallina, L., Goletz, S., Clark, B.F. and Kristensen, P. (2002) Functional improvement of antibody fragments using a novel phage coat protein III fusion system. Biochem. Biophys. Res. Commun. 298, 566-73.]. The rescue was accomplished by maintaining the fusion between the antibody fragment and portions of the filamentous bacteriophage coat protein 3, as present in the original antibody-displaying phage. In the present study, we have applied this system in an attempt to improve immunogenicity of anti-idiotypic antibodies isolated by phage display. Here we demonstrate that by preserving linkage between phage antibody and the N-terminal domain of phage coat protein 3, we induce multimerization of the antibody fragments, and improve their immunogenicity. This immunization approach allows induction of anti-idiotypic antibodies in mice, and facilitates the use of antibodies that are non-functional as non-fused soluble protein.


Assuntos
Adjuvantes Imunológicos/farmacologia , Anticorpos Anti-Idiotípicos/imunologia , Anticorpos Monoclonais/farmacologia , Proteínas do Capsídeo/farmacologia , Proteínas Recombinantes de Fusão/farmacologia , Adjuvantes Imunológicos/genética , Animais , Anticorpos Monoclonais/genética , Anticorpos Monoclonais/imunologia , Proteínas do Capsídeo/genética , Proteínas do Capsídeo/imunologia , Feminino , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/imunologia
20.
Rev. cuba. cir ; 62(1)mar. 2023.
Artigo em Espanhol | LILACS, CUMED | ID: biblio-1515254

RESUMO

Introducción: La coledocolitiasis se ha convertido en un problema de salud para el cual existen disímiles opciones de tratamiento. Objetivo: Exponer los resultados obtenidos con la colangiografía videolaparoscópica intraoperatoria y la colangiopancreatografía retrógrada endoscópica en pacientes con sospecha de coledocolitiasis. Métodos: Se realizó un estudio descriptivo retrospectivo en pacientes con sospecha de coledocolitiasis sometidos a colangiografía videolaparoscópica y la colangiopancreatografía endoscópica en el Hospital Militar Clínico Quirúrgico Docente de Camagüey Dr. Octavio de la Concepción y de la Pedraja durante el período de enero de 2015 a diciembre de 2019. El universo lo conformaron los 117 pacientes sometidos a ambos procederes. Se controlaron las variables de sospecha de coledocolitiasis, grupos de edades, sexo, hallazgos imagenológicos, complicaciones e índice de sospecha de coledocolitiasis. Resultados: En la colangiografía videolaparoscópica intraoperatoria fue mayor la posibilidad diagnóstica y menor las complicaciones. El diagnóstico de coledocolitiasis fue mayor en los pacientes sometidos a colangiopancreatografía retrógrada endoscópica, aunque esta no permitió evaluar a pacientes con bajo riesgo. Los pacientes del sexo femenino fueron más frecuentes en ambos grupos y la sospecha de coledocolitiasis se observó en grupo de edades entre 31 y 45 años. Sin embargo, fue normal el hallazgo de las vías biliares en ambos procederes. Conclusiones: Ambos métodos son seguros y útiles en el estudio en pacientes con sospecha de coledocolitiasis, con mayor eficacia diagnóstica para la técnica videolaparoscópica y menos complicaciones. El hallazgo normal de la vía biliar fue el resultado que prevaleció en ambos procederes(AU)


Introduction: Choledocholithiasis has become a health problem for which there are dissimilar treatment options. Objective: To present the results obtained with intraoperative videolaparoscopic cholangiography and endoscopic retrograde cholangiopancreatography in patients with suspected choledocholithiasis. Methods: A retrospective and descriptive study was conducted in patients with suspected choledocholithiasis and submitted to videolaparoscopic cholangiography and endoscopic cholangiopancreatography at Hospital Militar Clínico Quirúrgico Docente Dr. Octavio de la Concepción y de la Pedraja, of Camagüey, during the period from January 2015 to December 2019. The study universe consisted of 117 patients submitted to both procedures. The variables of suspected choledocholithiasis, age groups, sex, imaging findings, complications and index of suspected choledocholithiasis were controlled. Results: Intraoperative videolaparoscopic cholangiography had a higher diagnostic possibility and lower complications. The diagnosis of choledocholithiasis was higher in patients submitted to endoscopic retrograde cholangiopancreatography, although this did not allow the assessment of low-risk patients. Female patients were more frequent in both groups, while suspected choledocholithiasis was observed in patients between 31 and 45 years of age. However, the finding of a normal biliary tract was common to both procedures. Conclusions: Both methods are safe and useful in the study in patients with suspected choledocholithiasis, with greater diagnostic efficacy, as well as fewer complications, for the videolaparoscopic technique. The finding of a normal biliary tract was the prevailing result in both procedures(AU)


Assuntos
Humanos , Masculino , Feminino , Colangiografia/métodos , Colangiopancreatografia Retrógrada Endoscópica/métodos , Coledocolitíase/diagnóstico , Epidemiologia Descritiva , Estudos Retrospectivos
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