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1.
ESMO Open ; 8(4): 101584, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37379764

RESUMO

BACKGROUND: Combinations of avelumab [anti-programmed death-ligand 1 (anti-PD-L1)] or talazoparib [poly(adenosine diphosphate ribose) polymerase (PARP) inhibitor] with binimetinib (MEK inhibitor) were expected to result in additive or synergistic antitumor activity relative to each drug administered alone. Here, we report phase Ib results from JAVELIN PARP MEKi, which investigated avelumab or talazoparib combined with binimetinib in metastatic pancreatic ductal adenocarcinoma (mPDAC). PATIENTS AND METHODS: Patients with mPDAC that had progressed with prior treatment received avelumab 800 mg every 2 weeks plus binimetinib 45 mg or 30 mg two times daily (continuous), or talazoparib 0.75 mg daily plus binimetinib 45 mg or 30 mg two times daily (7 days on/7 days off). The primary endpoint was dose-limiting toxicity (DLT). RESULTS: A total of 22 patients received avelumab plus binimetinib 45 mg (n = 12) or 30 mg (n = 10). Among DLT-evaluable patients, DLT occurred in five of 11 patients (45.5%) at the 45-mg dose, necessitating de-escalation to 30 mg; DLT occurred in three of 10 patients (30.0%) at the 30-mg dose. Among patients treated at the 45-mg dose, one (8.3%) had a best overall response of partial response. Thirteen patients received talazoparib plus binimetinib 45 mg (n = 6) or 30 mg (n = 7). Among DLT-evaluable patients, DLT occurred in two of five patients (40.0%) at the 45-mg dose, necessitating de-escalation to 30 mg; DLT occurred in two of six patients (33.3%) at the 30-mg dose. No objective responses were observed. CONCLUSIONS: Combinations of avelumab or talazoparib plus binimetinib resulted in higher-than-expected DLT rates. However, most DLTs were single occurrences, and the overall safety profiles were generally consistent with those reported for the single agents. CLINICAL TRIAL REGISTRATION: ClinicalTrials.govNCT03637491; https://clinicaltrials.gov/ct2/show/NCT03637491.


Assuntos
Adenocarcinoma , Inibidores de Poli(ADP-Ribose) Polimerases , Humanos , Adenocarcinoma/tratamento farmacológico , Anticorpos Monoclonais/uso terapêutico , Inibidores de Poli(ADP-Ribose) Polimerases/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos
2.
J Chem Theory Comput ; 18(3): 1799-1807, 2022 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-35157796

RESUMO

Many-body excitations in X-ray photoemission spectra have been difficult to simulate from first principles. We have recently developed a cumulant-based one-electron Green's function method using the real-time coupled-cluster-singles equation-of-motion approach (RT-EOM-CCS) that provides a general framework for treating these problems. Here we extend this approach to include double excitations in the ground-state energy and in the coupled cluster amplitudes, which have been implemented using subroutines generated by the Tensor Contraction Engine (TCE). As in the case of the singles approximation, RT-EOM-CCSD yields a nonperturbative cumulant form of the Green's function in terms of the time-dependent cluster amplitudes, adding nonlinear corrections to the traditional cumulant forms. The extended approach is applied to the core-hole spectral function for small molecular systems. We find that, when core-optimized basis sets are used, the doubles contributions reduce the mean absolute errors in the core binding energies of the 10e systems from 0.8 to 0.3 eV. They also significantly improve the quasiparticle-satellite gap by reducing its overestimation from about 3-5 to about 0-1 eV in CH4, NH3, and H2O, and also improving the overall shape of the satellite features. Finally, we demonstrate the application of the new implementation to the larger, classical XPS ESCA series of molecules and show that the singles approximation can be paired with a modest basis set to study carbon speciation.

3.
Front Chem ; 9: 734945, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34631660

RESUMO

Green's function methods provide a robust, general framework within many-body theory for treating electron correlation in both excited states and x-ray spectra. Conventional methods using the Dyson equation or the cumulant expansion are typically based on the GW self-energy approximation. In order to extend this approximation in molecular systems, a non-perturbative real-time coupled-cluster cumulant Green's function approach has been introduced, where the cumulant is obtained as the solution to a system of coupled first order, non-linear differential equations. This approach naturally includes non-linear corrections to conventional cumulant Green's function techniques where the cumulant is linear in the GW self-energy. The method yields the spectral function for the core Green's function, which is directly related to the x-ray photoemission spectra (XPS) of molecular systems. The approach also yields very good results for binding energies and satellite excitations. The x-ray absorption spectrum (XAS) is then calculated using a convolution of the core spectral function and an effective, one-body XAS. Here this approach is extended to include the full coupled-cluster-singles (CCS) core Green's function by including the complete form of the non-linear contributions to the cumulant as well as all single, double, and triple cluster excitations in the CC amplitude equations. This approach naturally builds in orthogonality and shake-up effects analogous to those in the Mahan-Noizeres-de Dominicis edge singularity corrections that enhance the XAS near the edge. The method is illustrated for the XPS and XAS of NH3.

4.
J Chem Theory Comput ; 16(11): 6983-6992, 2020 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-33108872

RESUMO

Green's function methods within many-body perturbation theory provide a general framework for treating electronic correlations in excited states and spectra. Here, we develop the cumulant form of the one-electron Green's function using a real-time coupled-cluster equation-of-motion approach, in an extension of our previous study (Rehr J.; et al. J. Chem. Phys. 2020, 152, 174113). The approach yields a nonperturbative expression for the cumulant in terms of the solution to a set of coupled first-order, nonlinear differential equations. The method thereby adds nonlinear corrections to traditional cumulant methods, which are linear in the self-energy. The approach is applied to the core-hole Green's function and is illustrated for a number of small molecular systems. For these systems, we find that the nonlinear contributions yield significant improvements, both for quasiparticle properties such as core-level binding energies and for inelastic losses that correspond to satellites observed in photoemission spectra.

5.
J Pharm Biomed Anal ; 190: 113529, 2020 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-32841780

RESUMO

Despite the fact that more than 90% of vitamin D analysis are performed using immuno-enzymatic techniques, it is liquid chromatography coupled with tandem mass spectrometry that is currently the reference method. It allows for specific and selective analysis of all relevant vitamin D metabolites from a variety of biological materials, including serum or a dried blood spot. This paper presents development of a fast, cheap and high-throughput method of serum sample preparation using protein precipitation. For this purpose, organic solvent is used. Several substances were tested, including acetonitrile, methanol and their mixtures with zinc sulfate. However, the highest recovery values for the vitamin D metabolites were obtained for acetonitrile, with an organic solvent to serum ratio of 8:1. The preparation of a sample is carried out in 96-well plates and takes an hour and a half, together with a derivatization reaction using Cookson-type reagent 4-(4'-dimethylaminophenyl)-1,2,4-triazoline-3,5-dione. Due to the fact that vitamin D metabolites are bound to proteins, the relationship between the content of organic solvent in the sample preparation process and their release from the protein complex was examined. The results indicate that the organic solvent content should be 30-70% in order to completely release the tested compounds from the proteins. In addition, the developed chromatographic method has eliminated false positive signals for the 24,25(OH)2D3 metabolite. Total analysis time is 5.5 min., while maintaining resolution necessary to separate the analyzed compounds.


Assuntos
Espectrometria de Massas em Tandem , Vitamina D , Cromatografia Líquida , Indicadores e Reagentes , Limite de Detecção
6.
J Chem Phys ; 152(18): 184102, 2020 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-32414274

RESUMO

Specialized computational chemistry packages have permanently reshaped the landscape of chemical and materials science by providing tools to support and guide experimental efforts and for the prediction of atomistic and electronic properties. In this regard, electronic structure packages have played a special role by using first-principle-driven methodologies to model complex chemical and materials processes. Over the past few decades, the rapid development of computing technologies and the tremendous increase in computational power have offered a unique chance to study complex transformations using sophisticated and predictive many-body techniques that describe correlated behavior of electrons in molecular and condensed phase systems at different levels of theory. In enabling these simulations, novel parallel algorithms have been able to take advantage of computational resources to address the polynomial scaling of electronic structure methods. In this paper, we briefly review the NWChem computational chemistry suite, including its history, design principles, parallel tools, current capabilities, outreach, and outlook.

7.
J Chem Phys ; 152(17): 174113, 2020 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-32384843

RESUMO

We present a combined equation of motion coupled-cluster cumulant Green's function approach for calculating and understanding intrinsic inelastic losses in core level x-ray absorption spectra (XAS) and x-ray photoemission spectra. The method is based on a factorization of the transition amplitude in the time domain, which leads to a convolution of an effective one-body absorption spectrum and the core-hole spectral function. The spectral function characterizes intrinsic losses in terms of shake-up excitations and satellites using a cumulant representation of the core-hole Green's function that simplifies the interpretation. The one-body spectrum also includes orthogonality corrections that enhance the XAS at the edge.

8.
Body Image ; 32: 24-33, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31734408

RESUMO

The current study explored change in body-related self-conscious emotions (e.g., shame, guilt, authentic pride, hubristic pride) over three years, and tested body surveillance, age, weight status, years in sport, and competitive status as baseline predictors of change. Adolescent females engaged in organized sport (N = 518 at baseline, Mage = 14.02, SD = 1.38 years) completed a self-report survey once a year for three years (n = 293 and n = 215 in Years 2 and 3, respectively). Based on the unconditional latent growth model, body-related shame and guilt increased over time, and authentic and hubristic pride decreased over time. There was substantial between-person variability in the intercepts for all emotions and slopes for shame, guilt, and hubristic pride. In the conditional parallel process latent growth model, body surveillance predicted shallower change in shame and guilt over time. Female athletes high in body surveillance also reported higher body-related shame and guilt and lower authentic and hubristic pride at baseline. These findings highlight the importance of studying changes in self-conscious emotions over time in sport, and demonstrate that body surveillance may be an important factor to explore in interventions early in development.


Assuntos
Atletas/psicologia , Imagem Corporal/psicologia , Emoções , Esportes Juvenis/psicologia , Adolescente , Feminino , Humanos , Estudos Longitudinais , Autorrelato
9.
Neurosci Lett ; 694: 57-63, 2019 02 16.
Artigo em Inglês | MEDLINE | ID: mdl-30468888

RESUMO

Previous analyses of recordings of alpha motoneuron discharges from branches of the intercostal and abdominal nerves in anesthetized cats under neuromuscular blockade demonstrated modulation with the cardiac cycle. This modulation was interpreted as evidence that thoracic somatosensory afferents, most likely muscle spindles, provide a signal to the CNS that could contribute to cardiac interoception. Here, two aspects of these observations have been extended. First, new measurements of thoracic and abdominal EMG activity in spontaneously breathing dogs show that a very similar modulation exists in these rather different circumstances. Second, further analysis of the cat recordings shows that cardiac modulation of the discharges of bulbospinal neurons that transmit the expiratory drive to thoracic motoneurons is weak and of an inappropriate time-course to be a contributor to the effect seen in the motoneurons.


Assuntos
Músculos Abdominais/fisiologia , Expiração , Músculos Intercostais/fisiologia , Neurônios Motores/fisiologia , Medula Espinal/fisiologia , Músculos Abdominais/inervação , Animais , Gatos , Cães , Estimulação Elétrica , Eletromiografia , Músculos Intercostais/inervação , Masculino
10.
Analyst ; 144(1): 299-309, 2018 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-30403208

RESUMO

There are two forms of vitamin D which are essential to the human body, i.e. vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol). The inactive metabolites of vitamin D are commonly used for quantitative analysis because of their longer half-life, stability, and relatively high blood concentrations. This paper presents the development of a high-throughput and sensitive method for determining four vitamin D metabolites in dried blood spots using liquid chromatography coupled with tandem mass spectrometry. This method allows for the determination of 25(OH)D2 and 25(OH)D3 concentrations, as well as the epimeric form 3-epi-25(OH)D3 and 24,25(OH)2D3. The analyzed material is capillary blood taken from the fingertip, deposited on filter paper. Four different chromatographic columns were tested to separate all compounds, in particular, the epimeric form. The column of choice was F5 (Phenomenex, Torrance, CA, USA). In order to prove the consistency between the results for DBS, used as an alternative biological matrix, and serum, comparative studies of these two materials were carried out in nearly 100 individuals. The results indicated their positive correlation. The evaluation of short-term stability of metabolites in DBS within the month showed no change in metabolite concentration. During the validation, the impact of the matrix on the ionization of the tested compounds was evaluated. Capillary blood and venous blood collected for different anticoagulants were also compared. The smallest differences in the results were obtained for citrate. In order to achieve a limit of quantitation of 0.2 ng ml-1, sample preparation involved derivatization using a Cookson-type reagent, 4-(4'-dimethylaminophenyl)-1,2,4-triazoline-3,5-dione (DAPTAD).


Assuntos
Teste em Amostras de Sangue Seco/métodos , Hidroxicolecalciferóis/análise , Compostos de Anilina/química , Cromatografia Líquida/métodos , Feminino , Ensaios de Triagem em Larga Escala/métodos , Humanos , Hidroxicolecalciferóis/química , Limite de Detecção , Masculino , Estereoisomerismo , Espectrometria de Massas em Tandem/métodos , Triazóis/química
11.
J Appl Physiol (1985) ; 123(6): 1525-1531, 2017 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-28935824

RESUMO

In persons with spinal cord injury, lower thoracic low-frequency spinal cord stimulation (LF-SCS; 50 Hz, 15 mA) is a useful method to restore an effective cough. Unfortunately, the high-stimulus-amplitude requirements and potential activation of pain fibers significantly limit this application in persons with intact sensation. In this study, the mechanism of the expiratory muscle activation, via high-frequency SCS (HF-SCS; 500 Hz, 1 mA) was evaluated in dogs. In group 1, the effects of electrode placement on airway pressure generation (P) was evaluated. Maximal P occurred at the T9-T10 level with progressive decrements in P at more rostral and caudal levels for both LF-SCS and HF-SCS. In group 2, electromyographic (EMG) latencies of internal intercostal muscle (II) activation were evaluated before and after spinal root section and during direct motor root stimulation. Onset time of II EMG activity during HF-SCS was significantly longer (3.84 ± 1.16 ms) than obtained during direct motor root activation (1.61 ± 0.10 ms). In group 3, P and external oblique (EO) EMG activity, before and after sequential spinal section at the T11-T12 level, were evaluated. Bilateral dorsal column section significantly reduced EO EMG activity below the section and resulted in a substantial fall in P. Subsequent lateral funiculi section completely abolished those activities and resulted in further reductions in P. We conclude that 1) activation of the expiratory muscles via HF-SCS is dependent entirely on synaptic spinal cord pathways, and 2) HF-SCS at the T9 level produces a comparable level of muscle activation with that achieved with LF-SCS but with much lower stimulus amplitudes. NEW & NOTEWORTHY The findings in the present study suggest that lower thoracic high-frequency spinal cord stimulation with low stimulus currents results in sufficient activation of the expiratory muscles via spinal circuitry to produce large positive airway pressures sufficient to generate an effective cough mechanism. This method, therefore, may be applied in patient populations with intact sensation such as stroke and amyotrophic lateral sclerosis to restore an effective cough.


Assuntos
Tosse , Músculos Intercostais/fisiologia , Estimulação da Medula Espinal , Animais , Cães , Estimulação Elétrica , Eletrodos , Eletromiografia
13.
Respir Physiol Neurobiol ; 232: 54-6, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27395446

RESUMO

Spinal cord stimulation (SCS, 50Hz) is a useful method to restore an effective cough in persons with spinal cord injury (SCI). However, high stimulus amplitudes and potential activation of pain fibers, significantly limits this application. It is our hypothesis that high frequency SCS (HF-SCS), with low stimulus amplitudes may provide the same level of expiratory muscle activation. In 6 dogs, the effects of SCS, with varying stimulus parameters on positive pressure (P) generation was evaluated. At any given level of stimulus current, mean P was largest at 500Hz, compared to all other stimulus frequencies. For example, with stimulation at 1mA and frequencies of 200, 500 and 600Hz, P were 25±3, 58±4, 51±6cmH2O, respectively. By comparison, P achieved with conventional SCS parameters was 61±5cmH2O. HF-SCS results in a comparable P compared to that achieved with conventional stimulus parameters but with much lower stimulus amplitudes. This method may be useful to restore cough even in subjects with intact sensation.


Assuntos
Fenômenos Biofísicos/fisiologia , Tosse/terapia , Tosse/veterinária , Estimulação da Medula Espinal/métodos , Potenciais de Ação , Animais , Pressão Positiva Contínua nas Vias Aéreas , Tosse/etiologia , Modelos Animais de Doenças , Cães , Eletromiografia , Potencial Evocado Motor/fisiologia , Capacidade Residual Funcional/fisiologia , Laminectomia , Músculos Respiratórios/fisiologia , Traumatismos da Medula Espinal/complicações
14.
Microb Ecol ; 72(2): 407-17, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27260154

RESUMO

We hypothesize that bacterial endophytes may enhance the competitiveness and invasiveness of Phragmites australis. To evaluate this hypothesis, endophytic bacteria were isolated from P. australis. The majority of the shoot meristem isolates represent species from phyla Firmicutes, Proteobacteria, and Actinobacteria. We chose one species from each phylum to characterize further and to conduct growth promotion experiments in Phragmites. Bacteria tested include Bacillus amyloliquefaciens A9a, Achromobacter spanius B1, and Microbacterium oxydans B2. Isolates were characterized for known growth promotional traits, including indole acetic acid (IAA) production, secretion of hydrolytic enzymes, phosphate solubilization, and antibiosis activity. Potentially defensive antimicrobial lipopeptides were assayed for through application of co-culturing experiments and mass spectrometer analysis. B. amyloliquefaciens A9a and M. oxydans B2 produced IAA. B. amyloliquefaciens A9a secreted antifungal lipopeptides. Capability to promote growth of P. australis under low nitrogen conditions was evaluated in greenhouse experiments. All three isolates were found to increase the growth of P. australis under low soil nitrogen conditions and showed increased absorption of isotopic nitrogen into plants. This suggests that the Phragmites microbes we evaluated most likely promote growth of Phragmites by enhanced scavenging of nitrogenous compounds from the rhizosphere and transfer to host roots. Collectively, our results support the hypothesis that endophytic bacteria play a role in enhancing growth of P. australis in natural populations. Gaining a better understanding of the precise contributions and mechanisms of endophytes in enabling P. australis to develop high densities rapidly could lead to new symbiosis-based strategies for management and control of the host.


Assuntos
Antibiose , Bactérias/metabolismo , Raízes de Plantas/microbiologia , Poaceae/microbiologia , Microbiologia do Solo , Bactérias/classificação , Bactérias/isolamento & purificação , Biomassa , Fungos/crescimento & desenvolvimento , Ácidos Indolacéticos/metabolismo , Lipopeptídeos/biossíntese , Fixação de Nitrogênio , Fosfatos/metabolismo , Poaceae/crescimento & desenvolvimento , Simbiose
15.
J Chem Theory Comput ; 12(3): 1129-38, 2016 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-26808463

RESUMO

In this paper we discuss the implementation of multireference coupled-cluster formalism with singles, doubles, and noniterative triples (MRCCSD(T)), which is capable of taking advantage of the processing power of the Intel Xeon Phi coprocessor. We discuss the integration of two levels of parallelism underlying the MRCCSD(T) implementation with computational kernels designed to offload the computationally intensive parts of the MRCCSD(T) formalism to Intel Xeon Phi coprocessors. Special attention is given to the enhancement of the parallel performance by task reordering that has improved load balancing in the noniterative part of the MRCCSD(T) calculations. We also discuss aspects regarding efficient optimization and vectorization strategies.

16.
J Muscle Res Cell Motil ; 36(6): 395-404, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26613733

RESUMO

The skeletal muscle injury triggers the inflammatory response which is crucial for damaged muscle fiber degradation and satellite cell activation. Immunodeficient mice are often used as a model to study the myogenic potential of transplanted human stem cells. Therefore, it is crucial to elucidate whether such model truly reflects processes occurring under physiological conditions. To answer this question we compared skeletal muscle regeneration of BALB/c, i.e. animals producing all types of inflammatory cells, and SCID mice. Results of our study documented that initial stages of muscles regeneration in both strains of mice were comparable. However, lower number of mononucleated cells was noticed in regenerating SCID mouse muscles. Significant differences in the number of CD14-/CD45+ and CD14+/CD45+ cells between BALB/c and SCID muscles were also observed. In addition, we found important differences in M1 and M2 macrophage levels of BALB/c and SCID mouse muscles identified by CD68 and CD163 markers. Thus, our data show that differences in inflammatory response during muscle regeneration, were not translated into significant modifications in muscle regeneration.


Assuntos
Inflamação/patologia , Músculo Esquelético/patologia , Regeneração/fisiologia , Animais , Biomarcadores/metabolismo , Diferenciação Celular/fisiologia , Células Cultivadas , Inflamação/metabolismo , Macrófagos/metabolismo , Macrófagos/patologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos SCID , Músculo Esquelético/metabolismo , Doenças Musculares/metabolismo , Doenças Musculares/patologia
17.
J Chem Phys ; 141(9): 094102, 2014 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-25194359

RESUMO

In this paper we discuss a new formalism for producing an analytic coupled-cluster (CC) Green's function for an N-electron system by shifting the poles of similarity transformed Hamiltonians represented in N - 1 and N + 1 electron Hilbert spaces. Simple criteria are derived for the states in N - 1 and N + 1 electron spaces that are then corrected in the spectral resolution of the corresponding matrix representations of the similarity transformed Hamiltonian. The accurate description of excited state processes within a Green's function formalism would be of significant importance to a number of scientific communities ranging from physics and chemistry to engineering and the biological sciences. This is because the Green's function methodology provides a direct path for not only calculating properties whose underlying origins come from coupled many-body interactions but also provides a straightforward path for calculating electron transport, response, and correlation functions that allows for a direct link with experiment. As a special case of this general formulation, we discuss the application of this technique for Green's function defined by the CC with singles and doubles representation of the ground-state wave function.

18.
Orthopade ; 42(3): 157-63, 2013 Mar.
Artigo em Alemão | MEDLINE | ID: mdl-23455317

RESUMO

AIM: Before clinical implementation of an approved electromagnetic tracking system (CAPPA IRAD EMT) an experimental trial was performed to investigate the accuracy of the system and its safety in application for transpedicular vertebral punctures in comparison to the classical fluoroscopic method. MATERIAL AND METHODS: A total of 110 transpedicular punctures were performed bilaterally using 11 vertebrae of 5 realistic artificial phantoms and 1 pedicle was punctured with the conventional technique using c-arm fluoroscopy and the other with the electromagnetic tracking system. As a target a radiopaque non-ferromagnetic marker was implanted bilaterally in the anterior wall of the vertebrae. For evaluation of the precision the distance from the end of the puncture to the target and the gradual deviation of the actual channel from the ideal trajectory were assessed in three-dimensional computer tomography. Calculations and statistical analysis were performed according to the Wilcoxon test by means of SPSS 16.0.1 for Windows. RESULTS: The mean distance from the target was 6.6 mm (± 3.9 mm standard deviation SD) with electromagnetic navigation compared to 3.2 mm (± 2.8 mm SD) with fluoroscopic assistance and the mean aberration from the ideal trajectory was 18.4° (± 4.6° SD) compared to 6.5° (± 3.5° SD), respectively. The difference of accuracy was highly significant regarding both parameters (p < 0.001). CONCLUSIONS: The minimum requirement for accuracy of transpedicular punctures could not be achieved with electromagnetic navigation. Unless proven otherwise, the lack of accuracy is attributed to unstable referencing. Despite evidence of successful employment for soft tissue punctures the system cannot currently be recommended for osseous applications of the spine.


Assuntos
Magnetismo/instrumentação , Magnetismo/métodos , Punções/instrumentação , Punções/métodos , Coluna Vertebral/cirurgia , Cirurgia Assistida por Computador/instrumentação , Cirurgia Assistida por Computador/métodos , Campos Eletromagnéticos , Desenho de Equipamento , Análise de Falha de Equipamento , Humanos , Técnicas In Vitro , Coluna Vertebral/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos
19.
Rep Prog Phys ; 76(3): 034601, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23439452

RESUMO

Evaporation is ubiquitous in nature. This process influences the climate, the formation of clouds, transpiration in plants, the survival of arctic organisms, the efficiency of car engines, the structure of dried materials and many other phenomena. Recent experiments discovered two novel mechanisms accompanying evaporation: temperature discontinuity at the liquid-vapour interface during evaporation and equilibration of pressures in the whole system during evaporation. None of these effects has been predicted previously by existing theories despite the fact that after 130 years of investigation the theory of evaporation was believed to be mature. These two effects call for reanalysis of existing experimental data and such is the goal of this review. In this article we analyse the experimental and the computational simulation data on the droplet evaporation of several different systems: water into its own vapour, water into the air, diethylene glycol into nitrogen and argon into its own vapour. We show that the temperature discontinuity at the liquid-vapour interface discovered by Fang and Ward (1999 Phys. Rev. E 59 417-28) is a rule rather than an exception. We show in computer simulations for a single-component system (argon) that this discontinuity is due to the constraint of momentum/pressure equilibrium during evaporation. For high vapour pressure the temperature is continuous across the liquid-vapour interface, while for small vapour pressures the temperature is discontinuous. The temperature jump at the interface is inversely proportional to the vapour density close to the interface. We have also found that all analysed data are described by the following equation: da/dt = P(1)/(a + P(2)), where a is the radius of the evaporating droplet, t is time and P(1) and P(2) are two parameters. P(1) = -λΔT/(q(eff)ρ(L)), where λ is the thermal conductivity coefficient in the vapour at the interface, ΔT is the temperature difference between the liquid droplet and the vapour far from the interface, q(eff) is the enthalpy of evaporation per unit mass and ρ(L) is the liquid density. The P(2) parameter is the kinetic correction proportional to the evaporation coefficient. P(2) = 0 only in the absence of temperature discontinuity at the interface. We discuss various models and problems in the determination of the evaporation coefficient and discuss evaporation scenarios in the case of single- and multi-component systems.

20.
Adv Exp Med Biol ; 755: 19-25, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-22826045

RESUMO

Effectiveness of pulmonary rehabilitation in patients with chronic obstructive lung diseases, cystic fibrosis, and interstitial lung disease is well documented but little is known about the results of pulmonary rehabilitation in patients referred for lung transplantation. The purpose of this study is to prospectively examine the efficacy of Nordic walking, a low cost, accessible, and proven beneficial form of physical exercise, as a form of pulmonary rehabilitation in patients referred for lung transplantation. Twenty-two male patients referred for lung transplantation at the Department of Lung Diseases and Tuberculosis in Zabrze, Poland, were invited to take part in the study. The rehabilitation program, which was conducted for 12 weeks, was based on Nordic walking exercise training with ski poles. Lung function tests (FVC, FEV1), mobility (6 min walking test (6MWT)), rating of dyspnea (Oxygen Cost Index, MRC and Baseline Dyspnea Index), and quality of life assessments (SF-36) were performed before and after the completion of the exercise program. No adverse events were observed after completing the pulmonary rehabilitation program in patients referred for lung transplantation. After 12 weeks of pulmonary rehabilitation with Nordic walking we observed a significant increase in the mean distance walked in the 6MWT (310.2 m vs. 372.1 m, p < 0.05). The results of lung function tests also showed improvement in FVC. There were no significant differences in the perception of dyspnea before and after completing the rehabilitation program. General health and quality of life questionnaire (SF-36) showed improvement in the domain of social functioning (p < 0.05). In conclusion, pulmonary rehabilitation with a Nordic walking program is a safe and feasible physical activity in end-stage lung disease patients referred for lung transplantation and results in improvements in patients' mobility and quality of life.


Assuntos
Terapia por Exercício , Pneumopatias/reabilitação , Transplante de Pulmão , Humanos , Pneumopatias/psicologia , Masculino , Estudos Prospectivos , Qualidade de Vida , Encaminhamento e Consulta , Caminhada
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