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Is it possible that a measurement of a spin component of a spin-1/2 particle yields the value 100? In 1988 Aharonov, Albert and Vaidman argued that upon pre-and...  相似文献   
3.
The operating performances of a low-momentum (< 270 MeV/c) tagged beam are reported. The beam is obtained by means of the charge exchange reaction n on a liquid hydrogen target. The neutron associated to the in the two-body reaction is used for the determination of the energy and direction. The measured total rate of tagged is 8.02 ± 0.03 × 10−5 per incident at 300 MeV/c.  相似文献   
4.
The complexity of skeletal pathologies makes use of in vivo models essential to elucidate the pathogenesis of the diseases; nevertheless, chondrocyte and osteoblast cell lines provide relevant information on the underlying disease mechanisms. Due to the limitations of primary chondrocytes, immortalized cells represent a unique tool to overcome this problem since they grow very easily for several passages. However, in the immortalization procedure the cells might lose the original phenotype; thus, these cell lines should be deeply characterized before their use. We immortalized primary chondrocytes from a Cant1 knock-out mouse, an animal model of Desbuquois dysplasia type 1, with a plasmid expressing the SV40 large and small T antigen. This cell line, based on morphological and biochemical parameters, showed preservation of the chondrocyte phenotype. In addition reduced proteoglycan synthesis and oversulfation of glycosaminoglycan chains were demonstrated, as already observed in primary chondrocytes from the Cant1 knock-out mouse. In conclusion, immortalized Cant1 knock-out chondrocytes maintained the disease phenotype observed in primary cells validating the in vitro model and providing an additional tool to further study the proteoglycan biosynthesis defect. The same approach might be extended to other cartilage disorders.  相似文献   
5.
The radiation hardness of polysiloxane based scintillators has been measured by ion beam induced luminescence (IBIL). The light intensity as a function of the irradiation fluence with an He+ beam at 1.8 MeV (1.0 μA/cm2) has been measured on undoped polymers synthesized with different amounts of phenyl units and on polysiloxanes doped with two different dye molecules (BBOT and Lumogen Violet) sensitizing the scintillation yield.  相似文献   
6.
A novel linear silicon drift detector (SDD) is proposed in which the proper potential profile is established by the voltage drop along a unique p+ cathode implanted across the surfaces. This p+ implant, arranged in a zigzag shape, acts at the same time as voltage divider and field cathode and allows us to increase the sensitive area, improving also the uniformity of the thermal distribution and thus minimizing the fluctuation of the electron mobility on the sensitive zone of the SDD. The perturbations of the drift field due to the asymmetry of the strips constituting the zigzag cathode have been evaluated by solving analytically Poisson's equation for a simplified model of the structure. Three-dimensional numerical simulations have been carried out to prove the negligible amount of the perturbation and the effectiveness of the proposed structure. Based on this principle, a prototype has been manufactured at Canberra Semiconductor Company. Dynamic measurements of the time-of-flight of an injected charge prove that the linearity of the prototype and the drift uniformity in the anode direction are very high  相似文献   
7.
Abstract

We present a first experimental test of the existence of spontaneus parametric up conversion predicted in Marshall and co-workers [2000, J. mod. Optics, 47, 1273]. The measurement has been made using a ccd camera on the emission of a LiIO3 crystal pumped by a 351 nm and/or a 789 nm laser. We obtain an upper limit of 160 times on the ratio between the intensity of spontaneous parametric up conversion and spontaneous parametric down conversion.  相似文献   
8.
Airway inflammation plays a central role in bronchiectasis. Protease–antiprotease balance is crucial in bronchiectasis pathophysiology and increased presence of unopposed proteases activity may contribute to bronchiectasis onset and progression. Proteases’ over-reactivity and antiprotease deficiency may have a role in increasing inflammation in bronchiectasis airways and may lead to extracellular matrix degradation and tissue damage. Imbalances in serine proteases and matrix-metallo proteinases (MMPs) have been associated to bronchiectasis. Active neutrophil elastase has been associated with disease severity and poor long-term outcomes in this disease. Moreover, high levels of MMPs have been associated with radiological and disease severity. Finally, severe deficiency of α1-antitrypsin (AAT), as PiSZ and PiZZ (proteinase inhibitor SZ and ZZ) phenotype, have been associated with bronchiectasis development. Several treatments are under study to reduce protease activity in lungs. Molecules to inhibit neutrophil elastase activity have been developed in both oral or inhaled form, along with compounds inhibiting dipeptydil-peptidase 1, enzyme responsible for the activation of serine proteases. Finally, supplementation with AAT is in use for patients with severe deficiency. The identification of different targets of therapy within the protease–antiprotease balance contributes to a precision medicine approach in bronchiectasis and eventually interrupts and disrupts the vicious vortex which characterizes the disease.  相似文献   
9.
Interstitial lung diseases represent a heterogeneous and wide group of diseases in which factors leading to disease initiation and progression are not fully understood. Recent evidence suggests that the lung microbiome might influence the pathogenesis and progression of interstitial lung diseases. In recent years, the utilization of culture-independent methodologies has allowed the identification of complex and dynamic communities of microbes, in patients with interstitial lung diseases. However, the potential mechanisms by which these changes may drive disease pathogenesis and progression are largely unknown. The aim of this review is to discuss the role of the altered lung microbiome in several interstitial lung diseases. Untangling the host–microbiome interaction in the lung and airway of interstitial lung disease patients is a research priority. Thus, lung dysbiosis is a potentially treatable trait across several interstitial lung diseases, and its proper characterization and treatment might be crucial to change the natural history of these diseases and improve outcomes.  相似文献   
10.
The retrieval of atmospheric temperature profiles from microwave radiometer brightness temperatures requires the solution of a nonlinear inversion problem. An inversion technique based on neural networks (NN) is developed. The NN technique, compared with the classical inversion methods, exhibits better results in terms of retrieval accuracy, vertical resolution and elaboration time.  相似文献   
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