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Wyszukujesz frazę "b]-factor" wg kryterium: Temat


Tytuł:
A Neighborhood Condition for Fractional ID-[A, B]-Factor-Critical Graphs
Autorzy:
Zhou, Sizhong
Yang, Fan
Sun, Zhiren
Tematy:
graph
minimum degree
neighborhood
fractional [a
b]-factor
fractional ID-[a
b]-factor-critical graph
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Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Powiązania:
https://bibliotekanauki.pl/articles/31340936.pdf  Link otwiera się w nowym oknie
Opis:
Let $G$ be a graph of order $n$, and let $a$ and $b$ be two integers with $ 1 \le a \le b $. Let $ h : E(G) \rightarrow [0, 1] $ be a function. If \( a \le \Sigma_{ e \ni x } h(e) \le b \) holds for any $ x \in V (G) $, then we call $ G[F_h] $ a fractional $ [a, b] $-factor of $ G $ with indicator function $ h $, where $ F_h = \{ e \in E(G) : h(e) > 0 \} $. A graph $G$ is fractional independent-set-deletable $[a, b]$-factor-critical (in short, fractional ID-$[a, b]$-factor-critical) if $ G − I $ has a fractional $ [a, b] $-factor for every independent set $I$ of $G$. In this paper, it is proved that if $ n \ge \frac{(a+2b)(2a+2b-3)+1}{b} $, $ \delta (G) \ge \frac{bn}{a+2b} + a $ and $ | N_G(x) \cup N_G(y) | \ge \frac{(a+b)n}{a+2b} $ for any two nonadjacent vertices $ x, y \in V (G) $, then $ G $ is fractional ID-$[a, b]$-factor-critical. Furthermore, it is shown that this result is best possible in some sense.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
More on even [a,b]-factors in graphs
Autorzy:
Khodkar, Abdollah
Xu, Rui
Tematy:
[a,b]-factor
spanning graph
edge-connectivity
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Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Powiązania:
https://bibliotekanauki.pl/articles/743747.pdf  Link otwiera się w nowym oknie
Opis:
In this note we give a characterization of the complete bipartite graphs which have an even (odd) [a,b]-factor. For general graphs we prove that an a-edge connected graph G with n vertices and with δ(G) ≥ max{a+1,an/(a+b) + a - 2} has an even [a,b]-factor, where a and b are even and 2 ≤ a ≤ b. With regard to the edge-connectivity this result is slightly better than one of the similar results obtained by Kouider and Vestergaard in 2004 and unlike their results, this result has no restriction on the order of graphs.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Degree Condition Implying Ore-Type Condition for Even [2, b]-Factors in Graphs
Autorzy:
Tsuchiya, Shoichi
Yashima, Takamasa
Tematy:
[ a, b ]-factor
even factor
2-edge-connected
minimum degree
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Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Powiązania:
https://bibliotekanauki.pl/articles/31341635.pdf  Link otwiera się w nowym oknie
Opis:
For a graph $G$ and even integers $ b \ge a \ge 2 $, a spanning subgraph $F$ of $G$ such that $ a \le \text{deg}_F (x) \le b $ and $ \text{deg}_F (x) $ is even for all $ x \in V (F) $ is called an even $[a, b]$-factor of $G$. In this paper, we show that a 2-edge-connected graph $G$ of order $n$ has an even $[2, b]$-factor if $ \text{max} \{ \text{deg}_G (x) , \text{deg}_G (y) \} \ge \text{max} \{ \frac{2n}{2+b} , 3 \} $ for any nonadjacent vertices $x$ and $y$ of $G$. Moreover, we show that for $ b \ge 3a$ and $a > 2$, there exists an infinite family of 2-edge-connected graphs $G$ of order $n$ with $ \delta (G) \ge a$ such that $G$ satisfies the condition $ \text{deg}_G (x) + \text{deg}_G (y) > \frac{2an}{a+b} $ for any nonadjacent vertices $x$ and $y$ of $G$, but has no even $[a, b]$-factors. In particular, the infinite family of graphs gives a counterexample to the conjecture of Matsuda on the existence of an even $[a, b]$-factor.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The ability and utility of diffusion-weighted magnetic resonance imaging with different 'b' values in the differentiation of benign from malignant lung lesions
Autorzy:
Elbir, Şenol Fatih
Öztürk, Mehmet
Doğan, Serap
Opis:
Purpose: To evaluate the ability and the utility of diffusion-weighted magnetic resonance imaging (MRI) with different 'b' values to visualise benign and malignant lung lesions, and to determine which 'b' value (b = 300, 500, or 1000 s/mm2) was most useful in differentiating benign from malignant lung lesions. Material and methods: A total of 100 patients (28 women, 72 men; mean age = 57.19 ± 13.44 years; age range = 20-83 years). Diffusion-weighted imaging (DWI) was obtained with 'b' values of 300, 500, and 1000 s/mm². The signal intensity of lesions on DWI images was analysed, and the apparent diffusion coefficient (ADC) values of the lesions were calculated. MRI was performed in all patients after having presented at our department for thoracic computed tomography for various reasons. Results: A statistically significant difference in DWI signal scores was detected between benign and malignant lesions for all 'b' factors (p < 0.0001 for each). The sensitivity and specificity were 95% and 64%, respectively, when a score of 3 for b = 300 s/mm²; 90% and 69%, respectively, when a score of 3 for b = 500 s/mm²; and 84% and 74%, respectively, when a score of 3 for b = 1000 s/mm². ADC values showed significant differences between benign and malignant lesions for all 'b' factors (p < 0.0001 for each). Conclusions: Using 'b' values of 300, 500, and 1000 s/mm², DWI signal intensity scores and ADC values are effective methods for the differential diagnosis of malignant and benign pulmonary lesions.
Dostawca treści:
Repozytorium Uniwersytetu Jagiellońskiego
Artykuł
Tytuł:
Independence Number, Connectivity and All Fractional (a, b, k)-Critical Graphs
Autorzy:
Yuan, Yuan
Hao, Rong-Xia
Tematy:
independence number
connectivity
fractional [a
b]-factor
frac- tional (a
b
k)-critical graph
all fractional (a
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Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Powiązania:
https://bibliotekanauki.pl/articles/31343586.pdf  Link otwiera się w nowym oknie
Opis:
Let $G$ be a graph and $a$, $b$ and $k$ be nonnegative integers with $ 1 \le a \le b $. A graph $G$ is defined as all fractional $(a, b, k)$-critical if after deleting any $k$ vertices of $G$, the remaining graph has all fractional $[a, b]$-factors. In this paper, we prove that if \( \kappa(G) \ge \text{max} \{ \tfrac{(b+1)^2+2k}{2}, \tfrac{(b+1)^2 \alpha(G)+4ak}{4a} \} \), then $G$ is all fractional $(a, b, k)$-critical. If $k = 0$, we improve the result given in [Filomat 29 (2015) 757-761]. Moreover, we show that this result is best possible in some sense.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Potential role of transforming growth factor β1 in drug resistance of tumor cells.
Autorzy:
Stoika, Rostyslav
Yakymovych, Mariya
Souchelnytskyi, Serhiy
Yakymovych, Ihor
Tematy:
tumor cells
drug resistance
transforming growth factor b1
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Wydawca:
Polskie Towarzystwo Biochemiczne
Powiązania:
https://bibliotekanauki.pl/articles/1043628.pdf  Link otwiera się w nowym oknie
Opis:
Acquired drug resistance of tumor cells is frequently observed in cancer patients undergoing chemotherapy. We studied murine leukemia L1210 cells sensitive and resistant to the cytotoxic action of cisplatin and showed that cisplatin-resistant leukemia cells were also refractory to TGF β1-dependent growth inhibition and apoptosis. Addressing the question about the mechanisms responsible for the cross-resistance to cisplatin and TGF β1, we found that cisplatin- and TGF β1-resistant L1210 cells possessed a decreased expression of type I TGF β1 receptor, while the expression of type II TGF β1 receptor was not affected. Western blot analysis of Smad proteins 2, 3, 4, 6, and 7, which participate in signal transduction pathway down-stream of the TGF b1 receptors, revealed an increased expression of Smad 6, inhibiting TGF b1 action, only in cisplatin- and TGF β1-resistant L1210 cells. TGF β1 and especially the cytotoxic mistletoe agglutinin increased Smad 6 expression in TGF β1-sensitive but not in TGF β1-resistant L1210 cells. TGF β1-resistant L1210 cells also differed from TGF β1-sensitive cells by the lack of expression of the pro-apoptotic p53 protein and higher level of expression of the anti-apoptotic Bcl-2 protein. Thus, the described co-expression of tumor cell refractoriness to an anti-cancer drug and to the inhibitory cytokine TGF β1 is accompanied by multiple changes in the TGF β1 signal transduction pathway and in other regulatory systems of the target cells. Besides, we found that various anti-tumor drugs and cytotoxic plant lectins increased the level of TGF b1 expression in both TGF β1-sensitive and -resistant L1210 cells. A hypothesis is proposed that TGF β1 can at least partly mediate the effect of cell-stressing agents and, thus, the development of TGF β1 resistance may be responsible for the appearance of tumor cell refractoriness to the action of some anti-cancer drugs.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of differential serum expression of three factors and pulmonary function in patients with silicosis
Autorzy:
Zhu, Ying
Duan, Xia Yu
Cheng, Yun Qi
Yao, Xin Jing
Xu, Hong
Zhang, Kui Sheng
Li, Feng Shi
Yang, Fang
Liu, Liang He
Yuan, Xiang Ju
Tematy:
silicosis
pulmonary function
early diagnosis
ROC
PTPN2
factor B
Pokaż więcej
Wydawca:
Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Powiązania:
https://bibliotekanauki.pl/articles/2086531.pdf  Link otwiera się w nowym oknie
Opis:
ObjectivesSilicosis is a chronic occupational lung disease. As was previously found by the authors, some proteins increased in the lung tissue of activated rats, and protein tyrosine phosphatase non-receptor type 2 (PTPN2), factor B, and vaccinia-related kinase 1 (VRK1) showed highly differential expressions.Material and MethodsIn this study, serum and bronchoalveolar lavage fluid samples were collected from patients with silicosis and healthy people to verify the expression of PTPN2, factor B, and VRK1. The diagnostic value of differentially expressed proteins for silicosis was judged.ResultsThe expression levels of serum PTPN2, VRK1, and factor B in patients with silicosis were significantly higher than those in the control group (p < 0.01). Higher serum PTPN2 and factor B concentrations significantly and negatively correlated with the ratio of forced expiratory volume in 1 s to forced vital capacity (FEV1/FVC), maximum vital capacity (VCmax), FEV1, and FVC, suggesting that the high expression of PTPN2 and factor B is associated with decreased pulmonary ventilation function and restrictive ventilatory impairment in patients with silicosis. All area under curve (AUC) measurements generated from single detection events were >0.744, with PTPN2 reaching the highest value (0.858). The AUC, sensitivity, and specificity for the combined diagnosis using factor B and PTPN2 were 0.907, 86.91% and 85.07%, respectively, for factor B and PTPN2. The 3 differentially expressed proteins are potential classes of predictive biomarkers for silicosis.ConclusionsRegarding the economy and test practicality, the best diagnostic combination is factor B and PTPN2 for the analysis of AUC, sensitivity and specificity.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Influence of Aflatoxin B1 on the Concentration of Nuclear Factor κB in Rats’ Livers
Wpływ aflatoksyny B1 na stężenie czynnika jądrowego κB w wątrobach szczurów
Autorzy:
Woźniakowski, Mateusz
Woźniakowska, Nikola
Zuzak, Tomasz
Świerszcz, Łukasz
Wójciak-Czuła, Marta
Borzęcki, Andrzej
Nieradko-Iwanicka, Barbara
Tematy:
aflatoxin B1
nuclear factor κB
liver
aflatoksyna B1
czynnik jądrowy κB
wątroba
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Wydawca:
Polskie Towarzystwo Medycyny i Techniki Hiperbarycznej
Powiązania:
https://bibliotekanauki.pl/articles/32697700.pdf  Link otwiera się w nowym oknie
Opis:
Introduction. Aflatoxins are metabolites produced by Aspergillus flavus and Aspergillus parasiticus. Due to the high prevalence of aflatoxin-containing products they are common issue of the observational studies. Observational studies have demonstrated the hepatotoxic effects of aflatoxins in humans. However, the exact pathogenetic mechanisms of the effect of aflatoxin B1 on the above-mentioned hepatotoxicity have not yet been known. Aim of the study. The aim of the study was to assess the toxic effects of different doses of aflatoxin B1. The analyze was performed using assessment of concentration of NF-κB in liver tissue homogenates after a 7-day intoxication with this mycotoxin. Material and methods. The studies were carried out on Wistar male rats which were selected randomly, according to the principle of simultaneity for the control group and the study groups. The concentration of NK-κB was determined by immunoenzymatic ELISA in the obtained supernatants of liver taken from decapitated animals. The statistical analysis was performed with Statistica 13.3 (Statsoft, USA). Results. The statistical significance of the difference between the concentrations in the control and study group receiving 1.0 mg/kg of aflatoxin B1 and between the control and study group who received aflatoxin B1 at a dose of 2.0 mg/kg body weight (p <0,05) were demonstrated. A significant relationship was also found between the level of dose of aflatoxin B1 administered to the rats and the concentration of NF-κB. Negative correlations were obtained. The higher dose administered to rats - the lower level of measured concentration of NF-κB. Conclusions. The study of the influence of aflatoxin B1 on the level of NF-κB transcription factor may significantly contribute to understand the mechanism of its action, influence on inflammatory, apoptotic and carcinogenic processes in the liver and determine its safe level in food intended for humans and animals.
Wstęp. Aflatoksyny to metabolity wytwarzane przez Aspergillus flavus i Aspergillus parasiticus. Ze względu na duże rozpowszechnienie produktów zawierających aflatoksyny są one częstym przedmiotem badań obserwacyjnych. W dotychczasowych badaniach potwierdzono hepatotoksyczne działanie aflatoksyn u ludzi. Jednak dokładne mechanizmy patogenetyczne wpływu aflatoksyny B1 na wspomnianą hepatotoksyczność nie są jeszcze znane. Cel pracy. Celem pracy była ocena toksycznego efektu różnych dawek aflatoksyny B1. Analizę przeprowadzono przez ocenę stężenia NF-κB w homogenatach tkanki wątroby po 7-dniowym zatruciu tą mykotoksyną. Materiał i metody. Badania przeprowadzono na samcach szczurów rasy Wistar, które zostały wybrane losowo, zgodnie z zasadą jednoczesności dla grupy kontrolnej i grupy badawczej. Stężenie NK-κB oznaczono immunoenzymatycznym testem ELISA w otrzymanych supernatantach wątroby pobranych od zwierząt uśmierconych metodą dekapitacji. Analizę statystyczną przeprowadzono w programie Statistica 13.3 (Statsoft, USA). Wyniki. Stwierdzono różnice istotne statystycznie między stężeniami NK-κB w grupie kontrolnej i badanej otrzymującej 1,0 mg/kg aflatoksyny B1 oraz między grupą kontrolną i badaną, która otrzymywała aflatoksynę B1 w dawce 2,0 mg/kg masy ciała (p <0,05 ). Stwierdzono również istotną zależność pomiędzy poziomem dawki podawanej szczurom aflatoksyny B1 a stężeniem NF-κB. Uzyskano korelacje ujemne. Wyższa dawka podawana szczurom powodowała niższy poziom mierzonego stężenia NF-κB. Wnioski. Badanie wpływu aflatoksyny B1 na poziom czynnika transkrypcyjnego NF-κB może istotnie przyczynić się do zrozumienia mechanizmu jej działania, wpływu na procesy zapalne, apoptotyczne i kancerogenne w wątrobie oraz określenia jego bezpiecznego poziomu w żywności przeznaczonej dla ludzi i zwierząt.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The role of nuclear factor-κB in the development of autoimmune diseases: a link between genes and environment
Autorzy:
Kuryłowicz, Alina
Nauman, Janusz
Tematy:
autoimmune diseases
nuclear factor-κB (NF-κB)
genetic polymorphism
NF-κB targeted strategies
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Wydawca:
Polskie Towarzystwo Biochemiczne
Powiązania:
https://bibliotekanauki.pl/articles/1040661.pdf  Link otwiera się w nowym oknie
Opis:
Although autoimmune diseases are relatively common, mechanisms that lead to their development remain largely unknown. Nuclear factor-κB (NF-κB), as a key transcription factor involved in the regulation of immune responses and apoptosis, appears to be a good candidate for studies on the pathogenesis of autoimmunity. This review presents how perturbations of the NF-κB signaling pathway may contribute to self-tolerance failure, initiation of autoimmune inflammatory response as well as its persistent maintenance and therefore to the development of common autoimmune diseases including rheumatoid arthritis, multiple sclerosis, type 1 diabetes mellitus, thyroid autoimmune diseases, systemic lupus erythematosus as well as inflammatory bowel diseases and psoriasis. A special emphasis is put on the genetic variations in the NF-κB related genes and their possible association with susceptibility to autoimmune diseases, as well as on the therapeutic potential of the NF-κB targeted strategies in the treatment of autoimmunity.
Dostawca treści:
Biblioteka Nauki
Artykuł

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