RESUMO
This study is a metrological investigation of eight superconducting gravimeters that have operated in the Strasbourg gravimetric Observatory. These superconducting gravimeters include an older compact C026 model, a new observatory type iOSG23 and six iGravs (6, 15, 29, 30, 31, 32). We first compare the amplitude calibration of the meters using measurements from FG5 #206 absolute gravimeter (AG). In a next step we compute the amplitude calibration of all the meters by time regression with respect to iOSG23 itself carefully calibrated by numerous AG experiments. The relative calibration values are much more precise than absolute calibration for each instrument and strongly reduce any tidal residual signal. We also compare the time lags of the various instruments with respect to iOSG23, either by time cross-correlation or tidal analysis for the longest records (about 1 year). The instrumental drift behavior of the iGravs and iOSG23 is then investigated and we examine the relationships observed between gravity and body temperature measurements. Finally, we compare the noise levels of all the instruments. A three-channel correlation analysis is used to separate the incoherent (instrumental) noise from the coherent (ambient) noise. The self-noise is then compared to a model of thermal noise (Brownian motion) using the known instrumental parameters of the damped harmonic oscillator. The self-noise of iGrav instruments is well-explained by the thermal noise model at seismic frequencies (between 10-3 and 10-2 Hz). As expected, the self-noise of iOSG23 with a heavier sphere is also lower than that of iGravs at such frequencies.
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Here we present an extremely rare but important cause of pulmonary hemorrhage during pregnancy. A 41-year-old patient was seen with hemoptysis in the 29th week of her pregnancy which was initially assessed as unspecific inflammation. At the 34th week of pregnancy, she presented again, this time with hemoptoe and dizziness caused by an unknown idiopathic pulmonary AV malformation. The patient underwent extensive interdisciplinary evaluation including bronchoscopy, emergency cesarean section was performed, which was followed by CT scan and VATS/minithoracotomy with segment resection.
Assuntos
Fístula Arteriovenosa/diagnóstico por imagem , Hemoptise/etiologia , Artéria Pulmonar/anormalidades , Veias Pulmonares/anormalidades , Tomografia Computadorizada por Raios X , Adulto , Fístula Arteriovenosa/cirurgia , Broncoscopia , Cesárea , Feminino , Humanos , Gravidez , Complicações na Gravidez , Resultado da Gravidez , Artéria Pulmonar/diagnóstico por imagem , Artéria Pulmonar/cirurgia , Veias Pulmonares/diagnóstico por imagem , Veias Pulmonares/cirurgia , Cirurgia Torácica Vídeoassistida , Toracotomia , Resultado do TratamentoRESUMO
We present results of the timing performance studies of the optical part and front-end electronics of the time-of-flight subdetector prototype for the ATLAS Forward Proton (AFP) detector obtained during the test campaigns at the CERN-SPS test-beam facility (120 GeV π+ particles) in July 2016 and October 2016. The time-of-flight (ToF) detector in conjunction with a 3D silicon pixel tracker will tag and measure protons originating in central exclusive interactions p + p â p + X + p, where the two outgoing protons are scattered in the very forward directions. The ToF is required to reduce so-called pileup backgrounds that arise from multiple proton interactions in the same bunch crossing at high luminosity. The background can fake the signal of interest, and the extra rejection from the ToF allows the proton tagger to operate at the high luminosity required for the measurement of the processes. The prototype detector uses fused silica bars emitting Cherenkov radiation as a relativistic particle passes through them. The emitted Cherenkov photons are detected by a multi-anode micro-channel plate photomultiplier tube (MCP-PMT) and processed by fast electronics.
RESUMO
The ultrastructure of the ovary of Fasciola hepatica collected from field-infected sheep, was compared with that of flukes from laboratory-infected rats harbouring the Oberon or the Cullompton fluke isolate. At the periphery of the ovarian tubules, in all flukes, interstitial tissue was identified that appears to provide physical support and facilitate the metabolism of the germinal-line cells. Oogonia undergo mitotic division to maintain the cell population and to produce oocytes. Early oocytes feature conspicuous synaptonemal complexes in the nucleoplasm, and these become less evident as the oocytes grow in size, move towards the core of the ovarian tubule, and synthesise osmiophilic bodies. The latter may represent cortical granules, and serve to block polyspermy. The identity of the synaptonemal complexes was confirmed by immunocytochemical labelling of synaptonemal proteins. The occurrence of synaptonemal complexes in the oocytes of all fluke types examined indicates that pairing of bivalent chromosomes, with the potential for genetic recombination and chiasmata formation, is a feature of the triploid aspermic parthenogenetic Cullompton flukes, as well as of the wild-type out-breeding field-derived and Oberon isolate flukes. In oocytes within shelled eggs in the proximal uterus of all flukes, condensed chromosomes align at meiotic metaphase plates. Following the reduction division, two equal pronuclei appear in each oocyte in the distal uterus. On the basis of these observations, a mechanism of facultative parthenogenesis for F. hepatica is proposed that accommodates the survival and clonal expansion of triploid aspermic isolates.
Assuntos
Fasciola hepatica/fisiologia , Fasciola hepatica/ultraestrutura , Animais , Fasciola hepatica/genética , Feminino , Meiose , Microscopia Eletrônica de Transmissão , Oócitos/crescimento & desenvolvimento , Oócitos/ultraestrutura , Ovário/ultraestrutura , Partenogênese , Reprodução/fisiologia , Útero/ultraestruturaRESUMO
Several natural compound interfere with microtubules or the actin cytoskeleton. Compounds interfering with the microtubules like Vinca-alkaloids or taxanes, are extensively used for cancer therapy. In contrast, knowledge about pharmacological properties of actin binding drugs is poor and drugs interfering with actin are far from clinical use. Rhizopodin is a natural compound that strongly affects the actin cytoskeleton at nanomolar concentrations. Initial work revealed interesting anti-bacterial and cytotoxic effects, but the cellular effects and pharmacological properties of rhizopodin have not been characterized. We hypothesized that rhizopodin might exert anti-cancer activity. Therefore, the aim of this study was to characterize the cellular and pharmacological effects of rhizopodin in cancer. Effects of rhizopodin demonstrated prominent effects on the actin cytoskeleton as shown in the actin-pyrene assay and by immunostaining of cancer cells. To investigate cellular effects of rhizopodin, we analyzed cell proliferation, cell death induction by propidium iodide exclusion and western blot, as well as migration by impedance measurement using the xCELLligence device in MDA-MB-231 breast cancer and T24 bladder cancer cell lines. Rhizopodin inhibited proliferation and induced cell death of MDA-MB-231 and T24 cells at nanomolar concentrations. PARP cleavage by rhizopodin suggests caspase-dependent cell death induction. Importantly, rhizopodin potently inhibited MDA-MB-231 and T24 cancer cell migration at subtoxic doses where no actin aggregation was observed, indicating a specific underlying signaling of rhizopodin. In summary, our study elucidates rhizopodin as actin-binding natural compound that exerts potent anti-cancer effects. Therefore, our work provides the basis for further in depth characterization of rhizopodin as an antitumoral agent.
Assuntos
Actinas/metabolismo , Antineoplásicos Fitogênicos/farmacologia , Macrolídeos/farmacologia , Oxazóis/farmacologia , Morte Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Citoesqueleto/efeitos dos fármacos , Feminino , HumanosRESUMO
Controlling coherent interaction at avoided crossings and the dynamics there is at the heart of quantum information processing. A particularly intriguing dynamics is observed in the Landau-Zener regime, where periodic passages through the avoided crossing result in an interference pattern carrying information about qubit properties. In this Letter, we demonstrate a straightforward method, based on steady-state experiments, to obtain all relevant information about a qubit, including complex environmental influences. We use a two-electron charge qubit defined in a lateral double quantum dot as test system and demonstrate a long coherence time of T2 ≃ 200 ns, which is limited by electron-phonon interaction.
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Chicken astroviruses (CAstVs) have been characterized recently. Due to their relatively poor growth in cell culture, virus-specific antigens are not readily available for the development of diagnostic reagents and vaccines. For this purpose two capsid protein antigens, specified by the 11672 isolate of CAstV, were produced in insect cells following infection with recombinant baculoviruses. The GST-11672 capsid protein, a fusion protein comprising the capsid protein and glutathione-S-transferase (GST) as an N-terminal affinity tag, and the 11672 capsid protein alone were detected by western blotting as proteins of ~100 and 70 kDa, respectively. Immunization with the affinity-purified GST-11672 capsid protein produced a polyclonal rabbit antiserum, which reacted by indirect immunofluorescence with Group B CAstVs but which showed no reactivity with the Group A CAstV isolate, 612. When used as part of an immunoperoxidase-based immunohistochemical procedure, this rabbit antiserum facilitated the detection of CAstV antigen in formalin-fixed, paraffin-embedded kidney tissue at the sites of histopathology characteristic of nephritis. Although further evaluation with sera from commercial chickens is required, a prototype indirect antibody-detecting enzyme-linked immunosorbent assay (ELISA) based on affinity-purified GST-11672 capsid protein as coating antigen demonstrated considerable potential with low ELISA absorbance values being generated with sera from specific pathogen free (SPF) chickens, and high absorbance values being generated with serum samples from experimentally infected chickens. Immunization experiments of SPF chickens showed that, when administered as mixtures with oil adjuvant, crude cell lysates containing the GST-11672 capsid protein or the 11672 capsid protein elicited virus-specific antibody responses that were detectable by indirect immunofluorescence and by virus neutralization assays.
Assuntos
Infecções por Astroviridae/veterinária , Avastrovirus/imunologia , Proteínas do Capsídeo/metabolismo , Galinhas , Doenças das Aves Domésticas/prevenção & controle , Vacinação/veterinária , Animais , Anticorpos Antivirais/biossíntese , Anticorpos Antivirais/sangue , Especificidade de Anticorpos , Antígenos Virais/genética , Antígenos Virais/imunologia , Antígenos Virais/metabolismo , Infecções por Astroviridae/imunologia , Infecções por Astroviridae/prevenção & controle , Avastrovirus/genética , Baculoviridae/genética , Baculoviridae/metabolismo , Proteínas do Capsídeo/genética , Proteínas do Capsídeo/imunologia , Ensaio de Imunoadsorção Enzimática/veterinária , Soros Imunes/imunologia , Doenças das Aves Domésticas/diagnóstico , Doenças das Aves Domésticas/imunologia , Coelhos , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/metabolismo , Células Sf9 , Organismos Livres de Patógenos Específicos , SpodopteraRESUMO
The electronic structure of superconducting Fe1.03Te0.94S0.06 has been studied by angle-resolved photoemission spectroscopy (ARPES). Experimental band topography is compared to the calculations using the methods of Korringa-Kohn-Rostoker (KKR) with the coherent potential approximation (CPA) and the linearized augmented plane wave with local orbitals (LAPW+LO) method. The region of the Γ point exhibits two hole pockets and a quasiparticle peak close to the chemical potential (µ) with undetectable dispersion. This flat band with mainly d(z)(2) orbital character is most likely formed by the top of the outer hole pocket or is evidence of a third hole band. It may cover up to 3% of the Brillouin zone volume and should give rise to a Van Hove singularity. Studies performed for various photon energies indicate that at least one of the hole pockets has a two-dimensional character. The apparently nondispersing peak at µ is clearly visible for 40 eV and higher photon energies, due to an effect of the photoionization cross-section rather than band dimensionality. Orbital characters calculated by LAPW+LO for stoichiometric FeTe do not reveal the flat dz(2) band but are in agreement with the experiment for the other dispersions around Γ in Fe1.03Te0.94S0.06.
Assuntos
Ferro/química , Modelos Químicos , Modelos Moleculares , Espectroscopia Fotoeletrônica/métodos , Selênio/química , Telúrio/química , Simulação por Computador , Condutividade Elétrica , Transporte de Elétrons , Teste de MateriaisRESUMO
Charge carrier mobilities in molecular condensates are usually small, as the coherent transport, which is highly effective in conventional semiconductors, is impeded by disorder and the small intermolecular coupling. A significant band dispersion can usually only be observed in exceptional cases such as for π-stacking of aromatic molecules in organic single crystals. Here based on angular resolved photoemission, we demonstrate on the example of planar π-conjugated molecules that the hybridization with a metal substrate can substantially increase the delocalization of the molecular states in selective directions along the surface. Supported by ab initio calculations we show how this mechanism couples the individual molecules within the organic layer resulting in an enhancement of the in-plane charge carrier mobility.
RESUMO
Investigation of the triclabendazole (TCBZ) resistance status of populations of Fasciola hepatica in field cases of fasciolosis, where treatment failure has been reported, can be supported by histological examination of flukes collected from recently treated hosts. In TCBZ-sensitive flukes (TCBZ-S) exposed to TCBZ metabolites for 1-4days in vivo, but not in TCBZ-resistant flukes (TCBZ-R), morphological changes suggestive of apoptosis occur in cells undergoing meiosis or mitosis in the testis, ovary and vitelline follicles. In order to verify or refute the contention that efficacy of TCBZ treatment is associated with apoptosis in the reproductive organs of flukes, histological sections of TCBZ-S (Cullompton isolate) flukes and TCBZ-R (Sligo isolate) flukes were subjected to the TdT-mediated dUDP nick end labelling (TUNEL) in situ hybridisation method, a commercially available test specifically designed to label endonuclease-induced DNA strand breaks associated with apoptosis. Additionally, sections of in vivo-treated and untreated flukes originating from field outbreaks of suspected TCBZ-S and TCBZ-R fasciolosis were labelled by the TUNEL method. It was found that in treated TCBZ-S flukes, strong positive labelling indicating apoptosis was associated with morphologically abnormal cells undergoing mitosis or meiosis in the testis, ovary and vitelline follicles. Background labelling in the positive testis sections was attributed to heterophagy of cell debris by the sustentacular tissue. The triggering of apoptosis was probably related to failure of spindle formation at cell division, supporting the contention that TCBZ inhibits microtubule formation. In treated TCBZ-R (Sligo Type 1) flukes, and in treated flukes from field outbreaks of suspected TCBZ-R fasciolosis, no significant labelling was observed, while sections of fluke derived from a field case of fasciolosis where TCBZ resistance was not suspected were heavily labelled. Light labelling was associated with the testis of untreated Cullompton (TCBZ-S) and Sligo Type 2 (TCBZ-R) flukes, which exhibit abnormal spermatogenesis and spermiogenesis, respectively. This was attributed to apoptosis and to heterophagy of effete germ line cells by the sustentacular tissue. It is concluded that demonstration of apoptosis by in situ hybridisation using the TUNEL method on sections of 1-4days in vivo TCBZ-treated F. hepatica can contribute to the diagnosis of TCBZ resistance in field outbreaks of fasciolosis.
Assuntos
Anti-Helmínticos/farmacologia , Benzimidazóis/farmacologia , Quebras de DNA , Resistência a Medicamentos/efeitos dos fármacos , Endonucleases/metabolismo , Fasciola hepatica/citologia , Fasciola hepatica/efeitos dos fármacos , Animais , Apoptose , Fasciola hepatica/genética , Feminino , Genitália/citologia , Genitália/efeitos dos fármacos , Marcação In Situ das Extremidades Cortadas , Masculino , Ovinos , TriclabendazolRESUMO
A commercial coproantigen ELISA test for fasciolosis, based on the use of MM3 monoclonal antibody for antigen capture, was investigated for possible cross-reactivity with Paramphistomum cervi, a trematode that commonly infects cattle and sheep grazing in fluke-infested pasture in Ireland. Histological sections of adult and immature Fasciola hepatica and P cervi were incubated with MM3 monoclonal antibody, and its binding to tissue-localised coproantigen was subsequently visualised by immunocytochemistry. In a related study, the soluble antigenic fractions derived from homogenates of P cervi adults and Taenia hydatigena metacestodes were tested for cross-reactivity with MM3 monoclonal antibody in an antigen-capture ELISA, using known F hepatica-positive and F hepatica-negative ovine faecal samples as natural controls. It was found that, while intense immunocytochemical labelling was located over the gastrodermis and gut contents of adult and immature F hepatica, sections of adult and immature P cervi were unlabelled. In the ELISA tests, the soluble fractions of F hepatica reacted strongly with MM3 monoclonal antibody, but those of P cervi and T hydatigena gave negative results. These findings support the specificity of the coproantigen ELISA test for fasciolosis in areas where paramphistomosis and cysticercosis are liable to occur singly or as coinfections with F hepatica.
Assuntos
Antígenos de Helmintos/imunologia , Ensaio de Imunoadsorção Enzimática/veterinária , Paramphistomatidae/imunologia , Teníase/veterinária , Infecções por Trematódeos/veterinária , Animais , Anticorpos Anti-Helmínticos/análise , Anticorpos Monoclonais/imunologia , Bovinos , Doenças dos Bovinos/diagnóstico , Reações Cruzadas , Ensaio de Imunoadsorção Enzimática/normas , Fasciolíase/diagnóstico , Fasciolíase/epidemiologia , Fasciolíase/veterinária , Fezes/parasitologia , Sensibilidade e Especificidade , Ovinos , Doenças dos Ovinos/diagnóstico , Taenia/imunologia , Teníase/diagnóstico , Teníase/epidemiologia , Infecções por Trematódeos/diagnóstico , Infecções por Trematódeos/epidemiologiaRESUMO
Marek's disease (MD) is a disease of chickens that occurs worldwide and has serious economic consequences. MD can present as one of several forms, with the most commonly occurring forms being the lymphoproliferative diseases. Under experimental conditions, an early mortality syndrome has been recognized following infection by some but not all strains of MD virus (MDV). This is the first report of a confirmed case of mortality due to naturally occurring MDV infection in 1-week-old, nonvaccinated, chickens. Necrotizing lesions were observed in the bursa of Fabricius, lung, duodenum, jejunum, and proventriculus, and large intranuclear inclusion bodies were a striking feature in tissues with lesions in all birds. Immunohistochemical staining for the pp38 protein of MDV revealed abundant pp38 antigen in the affected tissues, confirming the presence of MDV within the lesions. PCR yielded an amplicon with 97% homology to the meq gene of MDV. No evidence of co-infection by either of the immunosuppressive agents chicken anemia virus and infectious bursal disease virus was detected.
Assuntos
Galinhas , Herpesvirus Galináceo 2/isolamento & purificação , Doença de Marek/virologia , Animais , Antígenos Virais/análise , DNA Viral/química , DNA Viral/genética , Herpesvirus Galináceo 2/genética , Imuno-Histoquímica/veterinária , Doença de Marek/mortalidade , Doença de Marek/patologia , Reação em Cadeia da Polimerase/veterináriaRESUMO
A sheep trial was performed to standardise a coproantigen reduction test (CRT) protocol for the diagnosis of resistance to triclabendazole (TCBZ) in Fasciola hepatica). The CRT employs the BIO K201 Fasciola coproantigen ELISA (Bio-X Diagnostics, Jemelle, Belgium) to test for the presence of F. hepatica coproantigens in a faecal sample. If it is coproantigen-positive, the CRT protocol recommends that faecal samples are re-tested for coproantigens at 14 days post-treatment (dpt), with negative testing at this point indicating TCBZ success. Initial work aimed to confirm the sensitivity of the BIO K201 ELISA for Fasciola infection and investigate whether coproantigens represent a robust reduction marker of TCBZ efficacy. Thirty-eight, indoor-reared sheep were artificially infected with F. hepatica isolates known to be susceptible (Cullompton) and resistant (Sligo) to TCBZ action, respectively. Treatment was administered at 12 weeks post-infection (wpi), with 2 sheep groups, infected with each isolate, culled at 2 and 4 weeks post-treatment (wpt), respectively. Necropsy was performed to confirm treatment efficacy. Individual faecal samples were collected twice-weekly throughout the trial period. Additional work focused on the effect of temperature on faecal sample collection and storage. Faecal samples collected from sheep positive for F. hepatica infection were sub-sampled and left at room temperature. Individual sub-samples were tested by ELISA on consecutive days and these readings compared to the original test result on the day of collection. In addition, ELISA values were compared between faecal sub-samples prepared on the day of sampling and post storage at -20°C. Also, an immunocytochemical study was performed to determine the tissue site of origin of the coproantigen protein in the fluke. Results showed that the BIO K201 ELISA was sensitive for Fasciola coproantigens, with coproantigens detectable from 5 wpi onwards. The suitability of coproantigens as a diagnostic marker of TCBZ efficacy was supported by the absence and presence of coproantigens in TCBZ-treated Cullompton (TCBZ-susceptible) and Sligo (TCBZ-resistant) F. hepatica infections at 2 and 4 wpt, respectively. Study results suggest that low to moderate temperature has little, if any, impact on coproantigen stability in faecal samples, but that higher temperatures may have. Immunolabelling for the coproantigen showed that it was specific to the gastrodermal cells of both adult and juvenile flukes.
Assuntos
Anti-Helmínticos/farmacologia , Antígenos de Helmintos/análise , Benzimidazóis/farmacologia , Resistência a Medicamentos , Ensaio de Imunoadsorção Enzimática/veterinária , Fasciola hepatica/efeitos dos fármacos , Animais , Fasciolíase/parasitologia , Fasciolíase/veterinária , Fezes/química , Feminino , Masculino , Sensibilidade e Especificidade , Ovinos , Doenças dos Ovinos/tratamento farmacológico , Doenças dos Ovinos/parasitologia , Fatores de Tempo , TriclabendazolRESUMO
We demonstrate the application of orbital k-space tomography for the analysis of the bonding occurring at metal-organic interfaces. Using angle-resolved photoelectron spectroscopy, we probe the spatial structure of the highest occupied molecular orbital and the former lowest unoccupied molecular orbital (LUMO) of one monolayer 3, 4, 9, 10-perylene-tetracarboxylic-dianhydride (PTCDA) on Ag(110) and (111) surfaces and, in particular, the influence of the hybridization between the orbitals and the electronic states of the substrate. We are able to quantify and localize the substrate contribution to the LUMO and thus prove the metal-molecule hybrid character of this complex state.
RESUMO
This article reports the results of necropsy, parasitologic, microbiologic, histopathologic, immunohistochemical, indirect immunofluorescence, biomolecular, and serologic investigations on 8 striped dolphins (Stenella coeruleoalba) found stranded from August to December 2007 on the Ligurian Sea coast of Italy. Severe, nonsuppurative meningoencephalitis was found in 4 animals, as characterized by prominent perivascular mononuclear cell cuffing and macrophage accumulations in neuropil. These lesions were associated with mild lymphocytic-plasmacytic infiltration of choroid plexuses in 1 dolphin. Toxoplasma gondii cysts and zoites, confirmed by immunohistochemical labeling, were scattered throughout the brain parenchyma of 2 of the 4 dolphins. No viral inclusions were seen in the brain of any animal. Other findings included severe bronchointerstitial pneumonia and pulmonary atelectasis, consolidation, and emphysema. Parasites were identified in a variety of organs, including lung (Halocerchus lagenorhynchi). Microbiologic and serologic examinations for Brucella spp were negative on all 8 dolphins. The 4 animals with meningoencephalitis had serum antibodies against T gondii (titers ranging from 1:80 to 1:320) but not against morbillivirus. In contrast, the other 4 dolphins were seropositive for morbillivirus (with titers ranging from 1:10 to 1:40) but seronegative for T gondii. No morbillivirus antigen or nucleic acid was detected in the tissues of any dolphin. It is concluded that the severe lung and brain lesions were the cause of death and that T gondii was the likely etiologic agent of the cerebral lesions. Morbillivirus infection was not considered to have contributed to death of these animals.
Assuntos
Infecções Protozoárias do Sistema Nervoso Central/veterinária , Golfinhos/parasitologia , Toxoplasma/isolamento & purificação , Toxoplasmose Animal/parasitologia , Toxoplasmose Cerebral/veterinária , Animais , Encéfalo/parasitologia , Infecções Protozoárias do Sistema Nervoso Central/epidemiologia , Infecções Protozoárias do Sistema Nervoso Central/parasitologia , Feminino , Técnica Indireta de Fluorescência para Anticorpo/veterinária , Imuno-Histoquímica , Itália/epidemiologia , Pulmão/parasitologia , Masculino , Testes de Neutralização/veterinária , RNA de Protozoário/química , RNA de Protozoário/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa/veterinária , Estudos Soroepidemiológicos , Toxoplasma/genética , Toxoplasmose Animal/epidemiologia , Toxoplasmose Cerebral/epidemiologia , Toxoplasmose Cerebral/parasitologiaRESUMO
The Aachen Total Artificial Heart (ACcor) has been under development at the Helmholtz Institute in Aachen over the last decade. It may serve as a bridge to transplant or as a long-term replacement of the natural heart. Based upon previous in vivo experiments with the ACcor total artificial heart, it was decided to optimize and redesign the pump unit. Smaller dimensions, passive filling and separability into three components were the three main design goals. The new design is called the MiniACcor, which is about 20% smaller than its predecessor, and weighs only 470 grams. Also its external driver/control unit was miniaturized and a new microcontroller was selected. To validate the design, it was extensively tested in laboratory mock loops. The MiniACcor was able to pump between 4.5 and 7 l/min at different pump rates against normal physiological pressures. Several requirements for the future compliance chamber and transcutaneous energy transmission (TET) system were also measured in the same mock loop. Further optimization and validation are being performed in cooperation with the Heart and Diabetes Centre North Rhine-Westphalia.
Assuntos
Coração Artificial , Desenho de Prótese , Animais , Aorta/cirurgia , Engenharia Biomédica/instrumentação , Volume Cardíaco/fisiologia , Bovinos , Átrios do Coração/cirurgia , Humanos , Miniaturização , Poliuretanos/química , Cloreto de Polivinila/química , Artéria Pulmonar/cirurgia , Volume Sistólico/fisiologiaRESUMO
We investigated the propagation of light in biological tissues that have aligned cylindrical microstructures (e.g., muscle, skin, bone, tooth). Because of pronounced anisotropic light scattering by cylindrical structures (e.g., myofibrils and collagen fibers) the spatially resolved reflectance exhibits a directional dependence that is different close to and far from the incident source. We applied Monte Carlo simulations, using the phase function of an infinitely long cylinder, to explain quantitatively the experimental results. These observations have consequences for noninvasive determination of the optical properties of tissue as well as for the diagnosis of early tissue alterations.
Assuntos
Algoritmos , Anisotropia , Artérias/fisiologia , Luz , Modelos Biológicos , Radiometria/métodos , Espalhamento de Radiação , Animais , Simulação por Computador , Doses de Radiação , Suínos , Tomografia de Coerência Óptica/métodosRESUMO
Delayed-type hypersensitivity (DTH) skin-testing with mycobacterial antigens is often used as a means of identifying Mycobacterium bovis-infected cattle. Better understanding of the cellular basis underlying the DTH reaction is required if diagnostic methods are to be improved upon. Previous studies have shown that gamma delta T-cells, particularly those bearing the WC1 molecule, are present at an early stage of developing DTH responses and that such cells may modulate the developing immune response immediately following M. bovis-infection. However, their role, if any, in the DTH response remains unclear. In the present study we have used an in vivo model to deplete WC1(+) gamma delta T-cells, from cattle with established M. bovis-infection, prior to skin-testing. Results indicate that, although WC1(+) gamma delta T-cells do infiltrate the skin-test site in normal calves, they do not appear to be essential for the development of DTH skin swelling, as indicated by effective development of skin responses in calves depleted of circulating WC1(+) gamma delta T-cells.
Assuntos
Hipersensibilidade Tardia/imunologia , Glicoproteínas de Membrana/imunologia , Mycobacterium bovis/imunologia , Receptores de Antígenos de Linfócitos T gama-delta/imunologia , Subpopulações de Linfócitos T/imunologia , Tuberculose Bovina/imunologia , Animais , Antígenos de Bactérias/imunologia , Bovinos , Citometria de Fluxo , Pele/imunologia , Testes CutâneosRESUMO
The identity of the lymphocyte subtypes constituting the lymphocytic mantle within developing early-stage lesions of bovine tuberculosis was investigated immunohistochemically in calves inoculated intranasally with 2 x 10(7) colony-forming units of a field isolate of Mycobacterium bovis. Pulmonary lesions were examined 7, 14, 21, 28 and 42 days after inoculation, and bronchial lymph node lesions at 35 days. The immunolabelling results reported were obtained with monoclonal antibodies against two T-cell epitopes (WC1+ gamma delta and CD2+) and against B-cell epitopes. Large numbers of CD2+ T-lymphocytes were observed around developing areas of necrosis throughout the study; WC1+ gamma delta cells, however, were more numerous at these sites up to and including day 21. On the other hand, aggregates of B lymphocytes did not become prominent in areas adjacent to lesions until day 42. The results suggest that these lymphocyte phenotypes play a role in the pathogenesis of early-stage lesions.