9,214 research outputs found
Top-Quark Decay at Next-to-Next-to-Next-to-Leading Order in QCD
We present the first complete high-precision QCD corrections to the inclusive
decay width , the -helicity fractions
and semi-inclusive distributions for the top-quark decay
process at NNNLO in the strong
coupling constant . In particular, the pure NNNLO QCD correction
decreases the by about of the previous NNLO result
at the top-quark pole mass scale, exceeding the error estimated by the usual
scale-variation prescription. After taking into account all sources of errors,
we get , the error of which meets the request by future
colliders. On the other hand, the NNNLO QCD effects on are
found to be much smaller, at the level of one per-mille for the dominating
, predestining them to act as precision observables for the top-quark
decay process.Comment: 7 pages, 3 figure
Service differentiation in OFDM-Based IEEE 802.16 networks
IEEE 802.16 network is widely viewed as a strong candidate solution for broadband wireless access systems. Various flexible mechanisms related to QoS provisioning have been specified for uplink traffic at the medium access control (MAC) layer in the standards. Among the mechanisms, bandwidth request scheme can be used to indicate and request bandwidth demands to the base station for different services. Due to the diverse QoS requirements of the applications, service differentiation (SD) is desirable for the bandwidth request scheme. In this paper, we propose several SD approaches. The approaches are based on the contention-based bandwidth request scheme and achieved by the means of assigning different channel access parameters and/or bandwidth allocation priorities to different services. Additionally, we propose effective analytical model to study the impacts of the SD approaches, which can be used for the configuration and optimization of the SD services. It is observed from simulations that the analytical model has high accuracy. Service can be efficiently differentiated with initial backoff window in terms of throughput and channel access delay. Moreover, the service differentiation can be improved if combined with the bandwidth allocation priority approach without adverse impacts on the overall system throughput
4-Bromo-2-[1-(4-ethoxyphenyl)-1-methylethyl]-1-methylbenzene
In title compound, C18H21BrO, the dihedral angle between two rings is 85.72°. No classical hydrogen bonds are found and only van der Waals forces stabilize the crystal packing
The current status of tumor microenvironment and cancer stem cells in sorafenib resistance of hepatocellular carcinoma
Hepatocellular carcinoma (HCC) is a heterogeneous and aggressive liver cancer that presents limited treatment options. Despite being the standard therapy for advanced HCC, sorafenib frequently encounters resistance, emphasizing the need to uncover the underlying mechanisms and develop effective treatments. This comprehensive review highlights the crucial interplay between the tumor microenvironment, cancer stem cells (CSCs), and epithelial-mesenchymal transition (EMT) in the context of sorafenib resistance. The tumor microenvironment, encompassing hypoxia, immune cells, stromal cells, and exosomes, exerts a significant impact on HCC progression and therapy response. Hypoxic conditions and immune cell infiltration create an immunosuppressive milieu, shielding tumor cells from immune surveillance and hindering therapeutic efficacy. Additionally, the presence of CSCs emerges as a prominent contributor to sorafenib resistance, with CD133+ CSCs implicated in drug resistance and tumor initiation. Moreover, CSCs undergo EMT, a process intimately linked to tumor progression, CSC activation, and further promotion of sorafenib resistance, metastasis, and tumor-initiating capacity. Elucidating the correlation between the tumor microenvironment, CSCs, and sorafenib resistance holds paramount importance in the quest to develop reliable biomarkers capable of predicting therapeutic response. Novel therapeutic strategies must consider the influence of the tumor microenvironment and CSC activation to effectively overcome sorafenib resistance in HCC
DNA Repair Pathways in Cancer Therapy and Resistance
DNA repair pathways are triggered to maintain genetic stability and integrity when mammalian cells are exposed to endogenous or exogenous DNA-damaging agents. The deregulation of DNA repair pathways is associated with the initiation and progression of cancer. As the primary anti-cancer therapies, ionizing radiation and chemotherapeutic agents induce cell death by directly or indirectly causing DNA damage, dysregulation of the DNA damage response may contribute to hypersensitivity or resistance of cancer cells to genotoxic agents and targeting DNA repair pathway can increase the tumor sensitivity to cancer therapies. Therefore, targeting DNA repair pathways may be a potential therapeutic approach for cancer treatment. A better understanding of the biology and the regulatory mechanisms of DNA repair pathways has the potential to facilitate the development of inhibitors of nuclear and mitochondria DNA repair pathways for enhancing anticancer effect of DNA damage-based therapy
Complete two-loop electroweak corrections to
We compute the complete two-loop electroweak corrections to the Higgsstralung
process at the future Higgs factory. The Feynman
integrals involved in the computation are decomposed into linear combinations
of a minimal set of master integrals taking advantage of the recent
developments of integral reduction techniques. The master integrals are then
evaluated by differential equations with boundary conditions provided by the
auxiliary mass flow method. Our final result for given is expressed
as a piecewise function defined by several deeply expanded power series, which
has high precision and can be further manipulated efficiently. Our calculation
presents the first complete two-loop electroweak corrections for processes with
four external particles.Comment: 5 pages, 2 figures. arXiv admin note: text overlap with
arXiv:2209.1425
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