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2.
Phys Rev Lett ; 116(8): 081802, 2016 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-26967410

RESUMO

The first direct measurement of electron neutrino quasielastic and quasielasticlike scattering on hydrocarbon in the few-GeV region of incident neutrino energy has been carried out using the MINERvA detector in the NuMI beam at Fermilab. The flux-integrated differential cross sections in the electron production angle, electron energy, and Q^{2} are presented. The ratio of the quasielastic, flux-integrated differential cross section in Q^{2} for ν_{e} with that of similarly selected ν_{µ}-induced events from the same exposure is used to probe assumptions that underpin conventional treatments of charged-current ν_{e} interactions used by long-baseline neutrino oscillation experiments. The data are found to be consistent with lepton universality and are well described by the predictions of the neutrino event generator GENIE.

3.
Phys Rev Lett ; 117(11): 111801, 2016 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-27661679

RESUMO

The MINERvA experiment observes an excess of events containing electromagnetic showers relative to the expectation from Monte Carlo simulations in neutral-current neutrino interactions with mean beam energy of 4.5 GeV on a hydrocarbon target. The excess is characterized and found to be consistent with neutral-current π^{0} production with a broad energy distribution peaking at 7 GeV and a total cross section of 0.26±0.02(stat.)±0.08(sys.)×10^{-39} cm^{2}. The angular distribution, electromagnetic shower energy, and spatial distribution of the energy depositions of the excess are consistent with expectations from neutrino neutral-current diffractive π^{0} production from hydrogen in the hydrocarbon target. These data comprise the first direct experimental observation and constraint for a reaction that poses an important background process in neutrino-oscillation experiments searching for ν_{µ} to ν_{e} oscillations.

4.
Phys Rev Lett ; 116(7): 071802, 2016 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-26943528

RESUMO

Two different nuclear-medium effects are isolated using a low three-momentum transfer subsample of neutrino-carbon scattering data from the MINERvA neutrino experiment. The observed hadronic energy in charged-current ν_{µ} interactions is combined with muon kinematics to permit separation of the quasielastic and Δ(1232) resonance processes. First, we observe a small cross section at very low energy transfer that matches the expected screening effect of long-range nucleon correlations. Second, additions to the event rate in the kinematic region between the quasielastic and Δ resonance processes are needed to describe the data. The data in this kinematic region also have an enhanced population of multiproton final states. Contributions predicted for scattering from a nucleon pair have both properties; the model tested in this analysis is a significant improvement but does not fully describe the data. We present the results as a double-differential cross section to enable further investigation of nuclear models. Improved description of the effects of the nuclear environment are required by current and future neutrino oscillation experiments.

5.
Phys Rev Lett ; 112(23): 231801, 2014 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-24972195

RESUMO

We present measurements of ν(µ) charged-current cross section ratios on carbon, iron, and lead relative to a scintillator (CH) using the fine-grained MINERvA detector exposed to the NuMI neutrino beam at Fermilab. The measurements utilize events of energies 2

6.
Phys Rev Lett ; 113(26): 261802, 2014 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-25615308

RESUMO

Neutrino-induced coherent charged pion production on nuclei νµA→µ(±)π(∓)A is a rare, inelastic interaction in which a small squared four-momentum |t| is transferred to the recoil nucleus, leaving it intact in the reaction. In the scintillator tracker of MINERvA, we remove events with evidence of particles from nuclear breakup and reconstruct |t| from the final-state pion and muon. We select low |t| events to isolate a sample rich in coherent candidates. By selecting low |t| events, we produce a model-independent measurement of the differential cross section for coherent scattering of neutrinos and antineutrinos on carbon. We find poor agreement with the predicted kinematics in neutrino generators used by current oscillation experiments.

7.
Phys Chem Chem Phys ; 16(48): 26816-22, 2014 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-25373725

RESUMO

Nanofibrous materials are essential components for a wide range of applications, particularly in the fields of medicine and material engineering. These include protective materials, sensors, cosmetics, hygiene, filtration and energy storage. The most widely used and researched technology in these fields is electrospinning. This method for producing fibers yields highly promising results thanks to its versatility and simplicity. Electrospinning is employed in multiple forms, among which needle and needleless direct current (DC) variants are the most distinctive. The former is based on the generation of just one single jet from a nozzle; hence this fabrication process is not very productive. The latter uses the destabilization of free liquid surfaces by means of an electric field, which enhances the throughput since it produces numerous jets, emitted from the surfaces of rollers, spheres, strings and spirals. However, although some progress in total producibility has been achieved, the efficiency of the DC method still remains relatively low. A further drawback of DC electrospinning is that both variants need a collector, which makes it difficult to combine DC electrospinning easily with other technologies due to the presence of the high field strength within the entire spinning zone. This paper describes our experiments with AC electrospinning. We show that alternating current (AC) electrospinning based on a needleless spinning-electrode provides a highly productive smoke-like aerogel composed of nanofibers. This aerogel rises rapidly from the electrode like a thin plume of smoke, without any need for a collector. Our work shows that AC needleless electrospinning gains its efficiency and collector-less feature thanks to the creation of a perpetually charge-changing virtual counter-electrode composed of the nanofibers emitted. High-speed camera recordings demonstrate the formation mechanism of the nanofibrous plume, which is wafted by an electric wind. This wind's velocity field is experimentally investigated. One potential use of AC needleless electrospinning is demonstrated here by spinning it into a yarn.

8.
Phys Rev Lett ; 111(2): 022501, 2013 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-23889388

RESUMO

We have isolated ν(µ) charged-current quasielastic (QE) interactions occurring in the segmented scintillator tracking region of the MINERvA detector running in the NuMI neutrino beam at Fermilab. We measure the flux-averaged differential cross section, dσ/dQ², and compare to several theoretical models of QE scattering. Good agreement is obtained with a model where the nucleon axial mass, M(A), is set to 0.99 GeV/c² but the nucleon vector form factors are modified to account for the observed enhancement, relative to the free nucleon case, of the cross section for the exchange of transversely polarized photons in electron-nucleus scattering. Our data at higher Q² favor this interpretation over an alternative in which the axial mass is increased.

9.
Phys Rev Lett ; 111(2): 022502, 2013 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-23889389

RESUMO

We report a study of ν(µ) charged-current quasielastic events in the segmented scintillator inner tracker of the MINERvA experiment running in the NuMI neutrino beam at Fermilab. The events were selected by requiring a µ- and low calorimetric recoil energy separated from the interaction vertex. We measure the flux-averaged differential cross section, dσ/dQ², and study the low energy particle content of the final state. Deviations are found between the measured dσ/dQ² and the expectations of a model of independent nucleons in a relativistic Fermi gas. We also observe an excess of energy near the vertex consistent with multiple protons in the final state.

10.
Biomed Mater ; 18(4)2023 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-37144351

RESUMO

Biocompatibility is one of the key issues for implants, especially in the case of stainless steel with medium to low biocompatibility, which may lead to a lack of osseointegration and consequently to implant failure or rejection. To precisely control preferential cell growth sites and, consequently, the biocompatibility of prosthetic devices, two types of surfaces were analyzed, containing periodic nanogrooves laser induced periodic surface structure (LIPSS) and square-shaped micropillars. For the fast and efficient production of these surfaces, the unique combination of high energy ultrashort pulsed laser system with multi-beam and beamshaping technology was applied, resulting in increased productivity by 526% for micropillars and 14 570% for LIPSS compared to single beam methods.In vitroanalysis revealed that micro and nanostructured surfaces provide a better environment for cell attachment and proliferation compared to untreated ones, showing an increase of up to 496% in the number of cells compared to the reference. Moreover, the combination of LIPSS and micropillars resulted in a precise cell orientation along the periodic microgroove pattern. The combination of these results demonstrates the possibility of mass production of functionalized implants with control over cell organization and growth. Thus, reducing the risk of implant failure due to low biocompatibility.


Assuntos
Próteses e Implantes , Aço Inoxidável , Propriedades de Superfície , Aço Inoxidável/química , Osseointegração , Proliferação de Células
11.
Vnitr Lek ; 55(10): 991-4, 2009 Oct.
Artigo em Tcheco | MEDLINE | ID: mdl-19947245

RESUMO

A 24-year-old man presented with cough, sore throat, fever, maculopapulous exanthema, pericardial and pleural effusion. Despite extensive evaluation neither infectious, autoimmune, hematological nor oncological disorders were revealed. Broad spectrum antibiotic and subsequently corticosteroid treatment failed to resolve the symptoms. Multiorgan failure with rapid progress of acute respiratory distress syndrome and circulatory failure developed and patient died. Adult onset Still's disease (AOSD), a diagnosis considered in this patient, is a rare disease with unknown prevalence, pathogenesis and etiology. Clinically it is characterized by spiking fever, arthritis, rash, and impairment of multiple organs. There is no single diagnostic test for AOSD. Rather, the diagnosis is based on the clinical criteria and requires the exclusion of infectious, neoplastic, and other autoimmune diseases. Rarely the course of the disease can be rapidly progressive to death. Treatment includes the use of non-steroid antirheumatic drugs and corticosteroids. Limited data suggest that biological agents (e.g. anti-TNF-alpha, anti-IL-1), rituximab or intravenous immunoglobulins might be promising for the treatment of severe cases.


Assuntos
Febre/etiologia , Insuficiência de Múltiplos Órgãos/complicações , Síndrome do Desconforto Respiratório/complicações , Doença de Still de Início Tardio/diagnóstico , Adulto , Progressão da Doença , Evolução Fatal , Humanos , Masculino , Adulto Jovem
12.
Cas Lek Cesk ; 147(10): 516-20, 2008.
Artigo em Tcheco | MEDLINE | ID: mdl-19177733

RESUMO

BACKGROUND: Enteral nutrition (EN) represents a preferred type of nutritional support in critical care patients, in spite of the high incidence of intolerance. One of the methods which can speed up the delivery of adequate amounts of food is to switch from the gastric to post-pyloric feeding. A three-luminal tube (TLT) enables post-pyloric enteral feeding with accompanying gastric decompression. The aim of our study was to evaluate effectiveness and safety of the endoscopically introduced TLT along with the estimation of the adequate dose of enteral nutrition. METHODS AND RESULTS: Retrospective analysis of 111 critical care patients with 140 introduced TLT during 2003 to 2006 in two intensive care units (UIC) in the Teaching hospital in Plzen included patients of average age 54 years (+/- 15), APACHE II score 26 (+/- 10) and UIC mortality was 24%. Eight introductions were technically not successful (6%). Reintroduction of the tube was necessary in 21 patients (19%). The average time of tube introduction was 6 minutes (+/- 3). In direct relation to endoscopy no serious complication was observed. In our cohort, 34 ventilator-associated pneumonias developed (31%). Average time interval since the admission to the hospital till TLT introduction was 7 days (+/- 6). Evaluation of a subgroup of 77 patients from one UIC has shown that the adequate amount of EN was achieved in 82% of patients in 4 days (+/- 3) after the TLT introduction. In average, TLT was introduced for 11 days (+/- 7). CONCLUSIONS: Endoscopic TLT introduction represents a safe and reliable method which can ensure adequate amount of enteral nutrition in majority of critical care patients with gastrointestinal dysfunction. In our conditions, TLT is probably not sufficiently used.


Assuntos
Cuidados Críticos , Nutrição Enteral , Intubação Gastrointestinal/instrumentação , APACHE , Endoscopia Gastrointestinal , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
13.
Vnitr Lek ; 54(10): 1000-5, 2008 Oct.
Artigo em Tcheco | MEDLINE | ID: mdl-19009768

RESUMO

Sepsis is the leading cause of mortality in non-coronary intensive care units. The uncontrolled and deregulated systemic inflammatory response to infection plays a central role in the pathophysiology of sepsis. This response is mediated by a broad spectrum of endogenous mediators leading to dysfunction in multiple organs remote from the primary infectious site. The failure of numerous clinical trials aimed at eliminating a single mediator stimulated the research to focus on non-selective removal of excessively produced mediators of sepsis. This "detoxification" forms the theoretical basis and biological rationale for the use of hemopurification therapies as an adjunctive treatment of sepsis. Our article reviews the current evidence of hemopurification methods in the supportive treatment of sepsis, briefly discusses new trends and summarizes the recommendations for clinical practice.


Assuntos
Hemofiltração , Sepse/terapia , Hemodiafiltração , Humanos , Terapia de Substituição Renal , Síndrome de Resposta Inflamatória Sistêmica/terapia
14.
Vnitr Lek ; 54(11): 1106-10, 2008 Nov.
Artigo em Tcheco | MEDLINE | ID: mdl-19069686

RESUMO

We present a case report of a 59-year-old man with a history of arterial hypertension and excision of malignant melanoma. He was admitted to the hospital because of two months history of diarrhoea, weight loss and circulatory collapse. In addition, the patient suffered from marked vegetative instability with symptomatic hypotension, polyneuropathy and progression of renal insufficiency, without proteinuria. Complex examination did not reveal neoplasms, endocrine, autoimmune, infectious or neurodegenerative disorders. A serial biopsy of colon failed to provide a clue to the diagnosis. However, AA amyloidosis was found on the kidney biopsy. Neither chronic inflammation nor malignancy was revealed and, hence, no causal treatment could have been established. The patient died from multiple organ failure. The autopsy confirmed systemic AA amyloidosis. The triad consisting ofdiarrhoea, polyneuropathy and hypotension should rise the suspicion on amyloidosis.


Assuntos
Amiloidose/diagnóstico , Diarreia/complicações , Hipotensão/complicações , Polineuropatias/complicações , Amiloidose/complicações , Amiloidose/patologia , Feminino , Humanos , Pessoa de Meia-Idade
15.
Cell Adh Migr ; 12(3): 271-285, 2018 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-29130836

RESUMO

Additive manufacturing, also called 3D printing, is an effective method for preparing scaffolds with defined structure and porosity. The disadvantage of the technique is the excessive smoothness of the printed fibers, which does not support cell adhesion. In the present study, a 3D printed scaffold was combined with electrospun classic or structured nanofibers to promote cell adhesion. Structured nanofibers were used to improve the infiltration of cells into the scaffold. Electrospun layers were connected to 3D printed fibers by gluing, thus enabling the fabrication of scaffolds with unlimited thickness. The composite 3D printed/nanofibrous scaffolds were seeded with primary chondrocytes and tested in vitro for cell adhesion, proliferation and differentiation. The experiment showed excellent cell infiltration, viability, and good cell proliferation. On the other hand, partial chondrocyte dedifferentiation was shown. Other materials supporting chondrogenic differentiation will be investigated in future studies.


Assuntos
Adesão Celular/fisiologia , Condrócitos/citologia , Nanofibras , Impressão Tridimensional , Alicerces Teciduais , Diferenciação Celular/fisiologia , Proliferação de Células/fisiologia , Células Cultivadas/fisiologia , Humanos , Nanofibras/química , Engenharia Tecidual/métodos
16.
Biomed Mater ; 13(2): 025004, 2018 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-29084934

RESUMO

Fibrous scaffolds are desired in tissue engineering applications for their ability to mimic extracellular matrix. In this study we compared fibrous scaffolds prepared from polycaprolactone using three different fabrication methods, electrospinning (ES), electro-blowing and melt-blown combined with ES. Scaffolds differed in morphology, fiber diameters and pore sizes. Mesenchymal stem cell adhesion, proliferation and osteogenic differentiation on scaffolds was evaluated. The most promising scaffold was shown to be melt-blown in combination with ES which combined properties of both technologies. Microfibers enabled good cell infiltration and nanofibers enhanced cell adhesion. This scaffold was used for further testing in critical sized defects in rabbits. New bone tissue formation occurred from the side of the treated defects, compared to a control group where only fat tissue was present. Polycaprolactone fibrous scaffold prepared using a combination of melt-blown and ES technology seems to be promising for bone regeneration. The practical application of results is connected with enormous production capacity and low cost of materials produced by melt-blown technology, compared to other bone scaffold fabrication methods.


Assuntos
Osso e Ossos/patologia , Nanofibras/química , Osteogênese/efeitos dos fármacos , Engenharia Tecidual/métodos , Alicerces Teciduais/química , Animais , Regeneração Óssea , Adesão Celular , Proliferação de Células , Sobrevivência Celular , Fêmur/patologia , Masculino , Células-Tronco Mesenquimais/citologia , Microscopia Eletrônica de Varredura , Polímeros/química , Coelhos
17.
Rozhl Chir ; 85(4): 159-62, 2006 Apr.
Artigo em Tcheco | MEDLINE | ID: mdl-16719410

RESUMO

AIM: The aim is to specify contemporary diagnostic and therapeutic procedures of liver injuries. METHODOLOGY: The authors present a trial group of 117 patients with various stages of liver injuries hospitalized at the Traumacentrum Surgical Department of the Faculty Hospital in Plzen from 1.1.2000 to 31.9.2005. 61 injured (52.1%) were treated conservatively, 56 (47.9%) surgically, who underwent 87 procedures, in total. RESULTS: 10 polytrauma patients exited (8.5%) from a haemorrhagic shock (group Moore IV-VI). Six subjects (5.1%) had complications on hospitalization. Average hospitalization lasted 18 days (1-69 days). CONCLUSION: The basic diagnostic tools in liver injuries include "bed side" ultrasonography, spiral computer tomography, in more complicated traumas also MRI, angiography or endoscopic retrograde cholangiography. As a treatment strategy, conservative methods prevail in haemodynamically stable patients, regardless of the liver injury stage. The objective of the surgical management is to provide "damage control surgery", i.e. the first procedure is aimed at life-saving, no time-demanding surgical procedures (e.g. liver tamponade), management of hypothermia, haemocoagulation and metabolic acidosis.


Assuntos
Fígado/lesões , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Hematoma/diagnóstico , Hematoma/terapia , Humanos , Lactente , Lacerações/diagnóstico , Lacerações/terapia , Pessoa de Meia-Idade , Traumatismo Múltiplo/diagnóstico , Traumatismo Múltiplo/terapia
18.
Cesk Pediatr ; 47(8): 484-6, 1992 Aug.
Artigo em Tcheco | MEDLINE | ID: mdl-1394555

RESUMO

The author reviews information on the use of a pulsatile magnetic field with defined parameters in some child diseases of the CNS according to his experience assembled during the past five years. PMP was applied in 17 cases with spinal amyotrophy type M. Werdnig-Hoffman and in 16 cases with DMO. In both diseases treatment was previously only symptomatic. PMP frequencies of alpha EEG waves were used during application on the area of the head and a different frequency for whole body treatment focused on muscular dystonia. The author draws attention to the specificity of biotropic parameters of the applied magnetic field.


Assuntos
Magnetismo/uso terapêutico , Atrofias Musculares Espinais da Infância/terapia , Paralisia Cerebral/terapia , Humanos , Lactente , Masculino
19.
Cell Prolif ; 46(1): 23-37, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23216517

RESUMO

OBJECTIVES: We prepared 3D poly (ε-caprolactone) (PCL) nanofibre scaffolds and tested their use for seeding, proliferation, differentiation and migration of mesenchymal stem cell (MSCs). MATERIALS AND METHODS: 3D nanofibres were prepared using a special collector for common electrospinning; simultaneously, a 2D PCL nanofibre layer was prepared using a classic plain collector. Both scaffolds were seeded with MSCs and biologically tested. MSC adhesion, migration, proliferation and osteogenic differentiation were investigated. RESULTS: The 3D PCL scaffold was characterized by having better biomechanical properties, namely greater elasticity and resistance against stress and strain, thus this scaffold will be able to find broad applications in tissue engineering. Clearly, while nanofibre layers of the 2D scaffold prevented MSCs from migrating through the conformation, cells infiltrated freely through the 3D scaffold. MSC adhesion to the 3D nanofibre PCL layer was also statistically more common than to the 2D scaffold (P < 0.05), and proliferation and viability of MSCs 2 or 3 weeks post-seeding, were also greater on the 3D scaffold. In addition, the 3D PCL scaffold was also characterized by displaying enhanced MSC osteogenic differentiation. CONCLUSIONS: We draw the conclusion that all positive effects observed using the 3D PCL nanofibre scaffold are related to the larger fibre surface area available to the cells. Thus, the proposed 3D structure of the nanofibre layer will find a wide array of applications in tissue engineering and regenerative medicine.


Assuntos
Técnicas de Cultura de Células/instrumentação , Diferenciação Celular , Células-Tronco Mesenquimais/citologia , Nanofibras/química , Poliésteres/química , Alicerces Teciduais , Técnicas de Cultura de Células/métodos , Movimento Celular , Proliferação de Células , Sobrevivência Celular , Células Cultivadas , Elasticidade , Humanos , Sialoproteína de Ligação à Integrina/metabolismo , Células-Tronco Mesenquimais/metabolismo , Nanofibras/ultraestrutura , Osteocalcina/metabolismo , Osteogênese , Medicina Regenerativa , Propriedades de Superfície , Engenharia Tecidual
20.
J Int Med Res ; 39(2): 629-36, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21672368

RESUMO

This study evaluated inflammatory, coagulation and microvascular responses to a continuous 24-h work day in 13 healthy intensive care physicians. Inflammatory markers (interleukin [IL]-2, IL-6, IL-10, tumour necrosis factor-α, matrix metalloproteinase [MMP]-9 and adiponectin), adhesion molecules (vascular cellular adhesion molecule-1 and intercellular adhesion molecule-1 [ICAM-1]), coagulation parameters (thrombin-anti thrombin, von Willebrand factor and tissue factor) and sublingual micro circulation were assessed before and after a 24-h work shift. The 24-h work shift had no effect on inflammatory markers and ICAM-1. Direct visualization of micro-circulation did not reveal stress-related perfusion abnormalities. A 24-h work shift in the intensive care unit was associated with significantly increased plasma levels of tissue factor - a potentially important mechanism linking acute job strain, haemostasis and atherosclerosis. The long-term consequences warrant further evaluation.


Assuntos
Fenômenos Biológicos , Pessoal de Saúde , Saúde , Unidades de Terapia Intensiva , Estresse Fisiológico , Adulto , Biomarcadores/sangue , Endotélio Vascular/fisiopatologia , Feminino , Hemodinâmica , Hemostasia , Humanos , Mediadores da Inflamação/metabolismo , Masculino , Microcirculação , Tromboplastina/metabolismo , Fatores de Tempo
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