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排序方式: 共有638条查询结果,搜索用时 23 毫秒
1.
Laura Francesca Pisani Gian Eugenio Tontini Carmine Gentile Beatrice Marinoni Isabella Teani Nicoletta Nandi Pasquale Creo Emanuele Asti Luigi Bonavina Maurizio Vecchi Luca Pastorelli 《International journal of molecular sciences》2021,22(11)
Interleukin (IL)-33 is a member of the interleukin (IL)-1 family of cytokines linked to the development of inflammatory conditions and cancer in the gastrointestinal tract. This study is designed to investigate whether IL-33 has a direct effect on human gastric epithelial cells (GES-1), the human gastric adenocarcinoma cell line (AGS), and the gastric carcinoma cell line (NCI-N87) by assessing its role in the regulation of cell proliferation, migration, cell cycle, and apoptosis. Cell cycle regulation was also determined in ex vivo gastric cancer samples obtained during endoscopy and surgical procedures. Cell lines and tissue samples underwent stimulation with rhIL-33. Proliferation was assessed by XTT and CFSE assays, migration by wound healing assay, and apoptosis by caspase 3/7 activity assay and annexin V assay. Cell cycle was analyzed by means of propidium iodine assay, and gene expression regulation was assessed by RT-PCR profiling. We found that IL-33 has an antiproliferative and proapoptotic effect on cancer cell lines, and it can stimulate proliferation and reduce apoptosis in normal epithelial cell lines. These effects were also confirmed by the analysis of cell cycle gene expression, which showed a reduced expression of pro-proliferative genes in cancer cells, particularly in genes involved in G0/G1 and G2/M checkpoints. These results were confirmed by gene expression analysis on bioptic and surgical specimens. The aforementioned results indicate that IL-33 may be involved in cell proliferation in an environment- and cell-type-dependent manner. 相似文献
2.
3.
Emanuele Viola 《Computational Complexity》2009,18(3):337-375
We prove new results on the circuit complexity of approximate majority, which is the problem of computing the majority of a given bit string whose fraction of 1’s is bounded away from 1/2 (by
a constant). We then apply these results to obtain new relationships between probabilistic time, BPTime (t), and alternating time, ∑O(1)Time (t). Our main results are the following:
相似文献
1. | We prove that depth-3 circuits with bottom fan-in (log n)/2 that compute approximate majority on n bits must have size at least 2n0.12^{n^{0.1}}. As a corollary we obtain that there is no black-box proof that BPTime (t) í ?2\subseteq \sum_2Time (o(t2)). This complements the (black-box) result that BPTime (t) í ?2\subseteq \sum_2Time (t2 · poly log t) (Sipser and Gács, STOC ’83; Lautemann, IPL ’83). |
2. | We prove that approximate majority is computable by uniform polynomial-size circuits of depth 3. Prior to our work, the only known polynomial-size depth-3 circuits for approximate majority were non-uniform (Ajtai, Ann. Pure Appl. Logic ’83). We also prove that BPTime (t) í ?3\subseteq \sum_3Time (t · poly log t). This complements our results in (1). |
3. | We prove new lower bounds for solving QSAT3 ? ?3\in \sum_3Time (n · poly log n) on probabilistic computational models. In particular, we prove that solving QSAT3 requires time n1+Ω(1) on Turing machines with a random-access input tape and a sequential-access work tape that is initialized with random bits. No nontrivial lower bound was previously known on this model (for a function computable in linear space). |
4.
A synchronizing word for a given synchronizing DFA is called minimal if none of its proper factors is synchronizing. We characterize the class of synchronizing automata having only finitely many minimal synchronizing words (the class of such automata is denoted by FG). Using this characterization we prove that any such automaton possesses a synchronizing word of length at most 3n-5. We also prove that checking whether a given DFA A is in FG is co-NP-hard and provide an algorithm for this problem which is exponential in the number of states A. 相似文献
5.
This paper shows how to apply discrete time non-homogeneous semi-Markov processes (DTNHSMP) with an age index to credit risk.
The idea is to consider the credit risk problem as a reliability model indexed by the age and in this way, many semi-Markov
results could be adapted to describe credit risk problem. The default state is seen as a “non working state”. As the semi-Markov
process is a generalization of Markov process, the presented model can be seen as a more general migration model. In fact,
in semi-Markov environment the distribution function (d.f.) of the waiting time before a transition can be of any type and
without the strong constraints of the Markov model. Furthermore, some results on the asymptotic behavior of the presented
model are given. This permits the construction of the d.f. of the default random variable for each “working state”. An example,
constructed manipulating some Standard & Poor’s (S&P) data, is presented. 相似文献
6.
Emanuele Maiorana Jordi Solé-Casals Patrizio Campisi 《Machine Vision and Applications》2016,27(8):1351-1360
Electroencephalography (EEG) has been recently investigated as a biometric modality for automatic people recognition purposes. Several studies have shown that brain signals possess subject-specific traits that allow distinguishing people. Nonetheless, extracting discriminative characteristics from EEG recordings may be a challenging task, due to the significant presence of artifacts in the acquired data. In order to cope with such issue, in this paper we evaluate the effectiveness of some preprocessing techniques in automatically removing undesired EEG contributions, with the aim of improving the achievable recognition rates. Specifically, methods based on blind source separation and sample entropy estimation are here investigated. An extensive set of experimental tests, performed over a large database comprising recordings taken from 50 healthy subjects during three distinct sessions spanning a period of about one month, in both eyes-closed and eyes-open conditions, is carried out to analyze the performance of the proposed approaches. 相似文献
7.
This paper proposes a novel class of Command Governor (CG) strategies for input and state-related constrained discrete-time LTI systems subject to bounded disturbances in the absence of explicit state or output measurements. While in traditional CG schemes the set-point manipulation is undertaken on the basis of either the actual measure of the state or its suitable estimation, it is shown here that the CG design problem can be solved, with limited performance degradation and with similar properties, also in the case that such an explicit measure is not available. This approach, which will be referred to as the Feed-Forward CG (FF-CG) approach, may be a convenient alternative CG solution in all situations whereby the cost of measuring the state may be a severe limitation, e.g. in distributed or decentralized applications. In order to evaluate the method proposed here, numerical simulations on a physical example have been undertaken and comparisons with the standard state-based CG solution reported. 相似文献
8.
We study the problem of the amount of information required to perform fast broadcasting in tree networks. The source located
at the root of a tree has to disseminate a message to all nodes. In each round each informed node can transmit to one child.
Nodes do not know the topology of the tree but an oracle knowing it can give a string of bits of advice to the source which can then pass it down the tree with the source message. The quality of a broadcasting algorithm with
advice is measured by its competitive ratio: the worst case ratio, taken over n-node trees, between the time of this algorithm and the optimal broadcasting time in the given tree. Our goal is to find a
trade-off between the size of advice and the best competitive ratio of a broadcasting algorithm for n-node trees. We establish such a trade-off with an approximation factor of O(n
ε
), for an arbitrarily small positive constant ε. This is the first communication problem for which a trade-off between the size of advice and the efficiency of the solution
is shown for arbitrary size of advice. 相似文献
9.
Bugané F Benedetti MG Casadio G Attala S Biagi F Manca M Leardini A 《Computer methods and programs in biomedicine》2012,108(1):129-137
This paper investigates the ability of a single wireless inertial sensing device stuck on the lower trunk to provide spatial-temporal parameters during level walking. The 3-axial acceleration signals were filtered and the timing of the main gait events identified. Twenty-two healthy subjects were analyzed with this system for validation, and the estimated parameters were compared with those obtained with state-of-the-art gait analysis, i.e. stereophotogrammetry and dynamometry. For each side, from four to six gait cycles were measured with the device, of which two were validated by gait analysis. The new acquisition system is easy to use and does not interfere with regular walking. No statistically significant differences were found between the acceleration-based measurements and the corresponding ones from gait analysis for most of the spatial-temporal parameters, i.e. stride length, stride duration, cadence and speed, etc.; significant differences were found for the gait cycle phases, i.e. single and double support duration, etc. The system therefore shows promise also for a future routine clinical use. 相似文献
10.
José D. Martín Guerrero Daniele Marcelli Emilio Soria-Olivas Flavio Mari José María Martínez-Martínez Isabel Soley Bech Marcelino Martínez-Sober Laura Scatizzi Juan Gómez-Sanchis Andrea Stopper Antonio José Serrano-López Emanuele Gatti 《Expert systems with applications》2012,39(10):8793-8798
Evaluation of patient satisfaction has become an important indicator for assessing health care quality. Fresenius Medical Care (FME) as a global provider of dialysis services through its NephroCare network has a strong interest in monitoring patient satisfaction.The aim of the paper is to test and validate a methodology for detecting a residual area of low satisfaction in dialysis patients.The FME Patient Satisfaction Programme questionnaire was distributed to haemodialysis (HD) patients treated in 335 centers of its network. It contained 79 questions covering various satisfaction aspects regarding Dialysis Unit, Dialysis Arrangement, Nurses, Doctors, etc.To analyse the data provided by the questionnaire, the Self-Organising Map (SOM) method was used. SOM is a neural network model for clustering and projecting high-dimensional data into a low-dimensional space, preserving topological relationships of original high-dimensional data spaces.10,632 HD patients completed the questionnaire. Mean age was 63.05 ± 14.93 years with 56.69% males. Response rate was 66%. Overall level of satisfaction was 1.99 (range from ?3 to +3). On average patients were very satisfied with all issues. Nevertheless, a group of patients, around 60 years old, balanced gender ratio, whose level of satisfaction was lower than 1, were highlighted.In the NephroCare clinics patient satisfaction with service is rather high. While traditional analysis usually stops here, the SOM method allows identification of areas of potential improvement for specific patient groups. 相似文献