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排序方式: 共有1235条查询结果,搜索用时 671 毫秒
61.
Alessandro Marchioni Roberto Tonelli Alessandro Andreani Gaia Francesca Cappiello Matteo Fermi Fabiana Trentacosti Ivana Castaniere Riccardo Fantini Luca Tabbì Dario Andrisani Filippo Gozzi Giulia Bruzzi Linda Manicardi Antonio Moretti Serena Baroncini Anna Valeria Samarelli Massimo Pinelli Giorgio De Santis Alessandro Stefani Daniele Marchioni Francesco Mattioli Enrico Clini 《International journal of molecular sciences》2022,23(5)
Laryngotracheal stenosis (LTS) is a complex and heterogeneous disease whose pathogenesis remains unclear. LTS is considered to be the result of aberrant wound-healing process that leads to fibrotic scarring, originating from different aetiology. Although iatrogenic aetiology is the main cause of subglottic or tracheal stenosis, also autoimmune and infectious diseases may be involved in causing LTS. Furthermore, fibrotic obstruction in the anatomic region under the glottis can also be diagnosed without apparent aetiology after a comprehensive workup; in this case, the pathological process is called idiopathic subglottic stenosis (iSGS). So far, the laryngotracheal scar resulting from airway injury due to different diseases was considered as inert tissue requiring surgical removal to restore airway patency. However, this assumption has recently been revised by regarding the tracheal scarring process as a fibroinflammatory event due to immunological alteration, similar to other fibrotic diseases. Recent acquisitions suggest that different factors, such as growth factors, cytokines, altered fibroblast function and genetic susceptibility, can all interact in a complex way leading to aberrant and fibrotic wound healing after an insult that acts as a trigger. However, also physiological derangement due to LTS could play a role in promoting dysregulated response to laryngo-tracheal mucosal injury, through biomechanical stress and mechanotransduction activation. The aim of this narrative review is to present the state-of-the-art knowledge regarding molecular mechanisms, as well as mechanical and physio-pathological features behind LTS. 相似文献
62.
Inclusion between XML types is important but expensive, and is much more expensive when unordered types are considered. We prove here that inclusion for XML types with interleaving and counting can be decided in polynomial time in the presence of two important restrictions: no element appears twice in the same content model, and Kleene star is only applied to disjunctions of single elements. 相似文献
63.
Giovanni Crupi Dominique M. M.‐P. Schreurs Alina Caddemi Antonio Raffo Giorgio Vannini 《国际射频与微波计算机辅助工程杂志》2010,20(1):87-93
The present article analyzes in detail different intrinsic small‐signal models for transistors. Particular attention is devoted to the non‐quasi‐static effects, which play a crucial role at microwave and millimeter‐wave frequencies. The advantages and disadvantages of these different equivalent circuit topologies are analyzed from both theoretical and experimental standpoints. This study clearly proves that best choice among these model representations depends on the specific device technology besides the investigated frequency range. © 2009 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2010. 相似文献
64.
Giorgio Brajnik Yeliz Yesilada Simon Harper 《Universal Access in the Information Society》2011,10(4):403-423
Web site-evaluation methodologies and validation engines take the view that all accessibility guidelines must be met to gain
compliance. Problems exist in this regard, as contradictions within the rule set may arise, and the type of impairment or
its severity is not isolated. The Barrier Walkthrough (BW) method goes someway to addressing these issues, by enabling barrier
types derived from guidelines to be applied to different user categories such as motor or visual impairment, etc. However,
the problem remains of combinatorial explosion of possibilities when one has to consider users with multiple disabilities.
In this paper, a simple set theory operation is used to create a validation scheme for older users by aggregating barrier
types specific to motor impaired and low-vision users, thereby creating a new “older users” category from the results of this
set union. To evaluate the feasibility and validity of this aggregation approach, two BW experiments were conducted. The first
experiment evaluated the aggregated results by focusing on quality attributes and showed that aggregation generates data whose
quality is comparable to the original one. However, this first experiment could not test for validity, as the older users
category was not included. To remedy this deficiency, another BW experiment was conducted with expert judges who evaluated
a web page in the context of older users. In this second experiment, it was found that there is no significant difference
between the aggregated and the manually evaluated (by experts) barrier scores, and that the same barriers are identified using
experts and aggregation, even though there are differences in how severity scores are distributed. From these results, it
is concluded that the aggregation of barriers is a viable alternative to expert evaluation, when the target of that aggregation
could not be evaluated manually or it would not be feasible to do so. It is also argued that aggregation is a technique that
can be used in combination with other evaluation methods, like user testing or subjective assessments. 相似文献
65.
Cognitive therapy and experiential dynamic therapy show quite many similarities but they diverge in their initial approach to the patient (aiming respectively at cognitions and at emotions) and in their assumptions about core pathogenetic processes. According to cognitive therapy patients suffer because of a negative unrealistic inner representation of self and world, whereas for experiential dynamic therapy problems arise from conflictual experience and expression of healthy feelings and needs. A synthetic model of the pathogenetic core process, embracing both a conflict about healthy needs and emotions, and a negative self-image, is outlined and discussed. In particular, the model's congruence with new knowledge emerging from infant and attachment research, emotion theory, and cognitive neurosciences is illustrated. Assuming an identity of their basic pathogenetic theory, the two therapies can be thought of as two initially different approaches, the one focusing more on cognitions, the other on emotions, but converging toward the change of a common pathogenetic core. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
66.
67.
Arianna Piersanti Tamara Tavoloni Eleonora Bastari Carmela Lestingi Sara Romanelli Rosanna Rossi Giorgio Saluti Simone Moretti Roberta Galarini 《Food Analytical Methods》2018,11(2):355-366
This paper describes the development and validation of an analytical method to determine 15 polybrominated diphenyl ethers (PBDEs) in fish and shellfish tissues with gas chromatography coupled to triple quadrupole mass spectrometry using electron impact source (GC-EI-MS/MS). A QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe)-like procedure was applied; the extract was cleaned up on an acidic Extrelut-NT3 column connected on top of a silica cartridge and further purified with gel permeation chromatography (GPC). The SIM acquisition proved to yield better results than traditional MRM approach for octa-, nona-, and deca-brominated congeners. The validation study was carried out in inter-laboratory conditions. The average recoveries were in the range 66–118%, with relative standard deviations generally lower than or equal to 22%. Quality assurance and quality control practices were thoroughly described and highlighted. These long and tedious practices are fundamental to obtain reliable quantitative data during food monitoring programs and, therefore, to support daily intake assessments. Finally, the procedure was applied to the analysis of marine fish samples collected in local markets. Mackerel and mullet were the most contaminated species. 相似文献
68.
Marco Carminati Giorgio Ferrari Aleksandar P. Ivanov Tim Albrecht Marco Sampietro 《Analog Integrated Circuits and Signal Processing》2013,77(3):333-343
Solid-state nanopores have been gaining popularity in nano-biotechnology for single molecule detection, in particular for label-free high-throughput DNA sequencing. In order to address the improvement of the resolution/speed trade-off critical in this application, here we present a new two-channel current amplifier tailored for solid-state nanopore devices with integrated tunneling electrodes. The simultaneous detection of ion and tunneling currents provides enhanced molecule tracking capability. We describe the system design starting from a detailed noise analysis and device modeling, highlighting the detrimental role of the conductive silicon substrate and of all the stray capacitive couplings between the electrodes. Given the high input capacitance (0.1–1 nF), the input voltage noise has been carefully minimized choosing a discrete couple of matched low-noise JFETs as input stage, thus achieving an equivalent input noise of 1.5 nV/√Hz (corresponding to a current noise floor of 15 fA/√Hz at 10 kHz). Low-noise performance (11 pA rms noise integrated over a 75 kHz bandwidth) is preserved at a wide bandwidth (300 kHz) and high gain (100 MΩ) thanks to the adoption of an improved integrator/differentiator cascade topology. Furthermore, along with biasing networks and selectable low-pass filters, an AC-coupled channel providing additional gain has been introduced in order to “zoom” in the current signature during pore blockade events. Together with an experimental characterization of the system (and comparison with the noise performance of other instruments), the platform is validated by demonstrating the detection of λ-DNA with 20 nm pores. 相似文献
69.
70.
On measuring the accuracy of SLAM algorithms 总被引:1,自引:0,他引:1
Rainer Kümmerle Bastian Steder Christian Dornhege Michael Ruhnke Giorgio Grisetti Cyrill Stachniss Alexander Kleiner 《Autonomous Robots》2009,27(4):387-407
In this paper, we address the problem of creating an objective benchmark for evaluating SLAM approaches. We propose a framework
for analyzing the results of a SLAM approach based on a metric for measuring the error of the corrected trajectory. This metric
uses only relative relations between poses and does not rely on a global reference frame. This overcomes serious shortcomings
of approaches using a global reference frame to compute the error. Our method furthermore allows us to compare SLAM approaches
that use different estimation techniques or different sensor modalities since all computations are made based on the corrected
trajectory of the robot.
We provide sets of relative relations needed to compute our metric for an extensive set of datasets frequently used in the
robotics community. The relations have been obtained by manually matching laser-range observations to avoid the errors caused
by matching algorithms. Our benchmark framework allows the user to easily analyze and objectively compare different SLAM approaches. 相似文献