Computation offloading services provide required computing resources for vehicles with computation-intensive tasks. Past computation offloading research mainly focused on mobile edge computing (MEC) ...or cloud computing, separately. This paper presents a collaborative approach based on MEC and cloud computing that offloads services to automobiles in vehicular networks. A cloud-MEC collaborative computation offloading problem is formulated through jointly optimizing computation offloading decision and computation resource allocation. Since the problem is non-convex and NP-hard, we propose a collaborative computation offloading and resource allocation optimization (CCORAO) scheme, and design a distributed computation offloading and resource allocation algorithm for CCORAO scheme that achieves the optimal solution. The simulation results show that the proposed algorithm can effectively improve the system utility and computation time, especially for the scenario where the MEC servers fail to meet demands due to insufficient computation resources.
Pandemics have become more frequent and more complex during the twenty-first century. Posttraumatic stress disorder (PTSD) following pandemics is a significant public health concern. We sought to ...provide a reliable estimate of the worldwide prevalence of PTSD after large-scale pandemics as well as associated risk factors, by a systematic review and meta-analysis. We systematically searched the MedLine, Embase, PsycINFO, Web of Science, CNKI, WanFang, medRxiv, and bioRxiv databases to identify studies that were published from the inception up to August 23, 2020, and reported the prevalence of PTSD after pandemics including sudden acute respiratory syndrome (SARS), H1N1, Poliomyelitis, Ebola, Zika, Nipah, Middle Eastern respiratory syndrome coronavirus (MERS-CoV), H5N1, and coronavirus disease 2019 (COVID-19). A total of 88 studies were included in the analysis, with 77 having prevalence information and 70 having risk factors information. The overall pooled prevalence of post-pandemic PTSD across all populations was 22.6% (95% confidence interval (CI): 19.9-25.4%, I
: 99.7%). Healthcare workers had the highest prevalence of PTSD (26.9%; 95% CI: 20.3-33.6%), followed by infected cases (23.8%: 16.6-31.0%), and the general public (19.3%: 15.3-23.2%). However, the heterogeneity of study findings indicates that results should be interpreted cautiously. Risk factors including individual, family, and societal factors, pandemic-related factors, and specific factors in healthcare workers and patients for post-pandemic PTSD were summarized and discussed in this systematic review. Long-term monitoring and early interventions should be implemented to improve post-pandemic mental health and long-term recovery.
The activation of mixed lineage kinase-like (MLKL) by receptor-interacting protein kinase-3 (RIPK3) results in plasma membrane (PM) disruption and a form of regulated necrosis, called necroptosis. ...Here, we show that, during necroptosis, MLKL-dependent calcium (Ca2+) influx and phosphatidylserine (PS) exposure on the outer leaflet of the plasma membrane preceded loss of PM integrity. Activation of MLKL results in the generation of broken, PM “bubbles” with exposed PS that are released from the surface of the otherwise intact cell. The ESCRT-III machinery is required for formation of these bubbles and acts to sustain survival of the cell when MLKL activation is limited or reversed. Under conditions of necroptotic cell death, ESCRT-III controls the duration of plasma membrane integrity. As a consequence of the action of ESCRT-III, cells undergoing necroptosis can express chemokines and other regulatory molecules and promote antigenic cross-priming of CD8+ T cells.
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•Phosphatidylserine is exposed prior to loss of cell integrity during necroptosis•ESCRT-III facilitates the shedding of MLKL-damaged plasma membrane from intact cells•ESCRT-III supports cell survival and functions downstream of active MLKL•ESCRT-III allows necroptotic cells to signal surrounding cells
Cells undergoing necroptosis are not always headed towards death; ESCRT-III helps preserve the plasma membrane in these cells, contributing to survival.
To the edge of cell death and back Gong, Yi‐Nan; Crawford, Jeremy Chase; Heckmann, Bradlee L. ...
The FEBS journal,
February 2019, Letnik:
286, Številka:
3
Journal Article
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Programmed cell death plays a central role in maintaining homeostasis. Various studies have demonstrated that programmed cell death is not a one‐way street; cells can survive even when the core cell ...death processes are underway. Cell death initiation, prevention, and recovery function in a coordinated fashion to establish and maintain a homeostatic environment. In this review, we discuss how dying cells can be rescued from death's grip and the subsequent physiological consequences. We suggest a fundamental question to be answered—at least at the single cell level is, can we predict if a certain cell is more or less likely to survive or die? And importantly, what physiological and pathological consequences, as well as therapeutic approaches can we delineate from this ability to predict cell death versus survival.
A dying cell on the edge of death may have distinct fates. They can of course proceed to the end (plasma membrane permeabilization), or surprisingly, they can revive. Each pathway leads to different biological consequences. This review will discuss how and why the dying cells make life/death decisions. To be or not to be, a dying cell is thinking…
Hydrogen sulfide (H2S) has been recognized as an important gaseous signaling molecule in living systems, and is of great significance in many pathological and physiological processes. Misregulation ...of endogenous H2S is implicated in various diseases in the neuronal, gastrointestinal, circulatory, and endocrine systems. Fluorescent probe with large Stokes shift and near infrared emission, is ideal candidate for imaging applications to prevent excitation scattering, autofluorescence interference, matrix absorption caused signal loss, and sample destruction. In this study, a dual-side expansion approach was performed to develop spectra tunable hydroxyl functional flavylium derivative named HN8 with enlarged Stokes shift of 81 nm, lengthened emission of 671 nm, satisfied quantum yield of 0.23, and good fluorescence enhancement factor of 14.3-fold. Moreover, based on HN8, the screened probe HN8DNP displayed 225-fold fluorescence enhancement containing linear correlations to H2S from 0 to 50 μM with good limit of detection (LOD) of 0.31 μM. Therefore, HN8DNP was then applied for imaging exogenous H2S and drug induced enzymatic H2S generation in living cells with satisfied results, revealing the relationship between intracellular H2S levels and related enzyme activities. In a word, the present work provided a potential fluorescence probe for highly selective and sensitive detecting H2S in vitro and in living cells. And the promising dual-side expansion strategy for regulation optical feature of traditional fluorophore may meet the increasing requirements of sensing and imaging applications.
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•HN8 has Stokes shift of 81 nm, emission of 671 nm, and quantum yield of 0.23.•HN8 showed 14.3-fold fluorescence enhancement factor.•Probe HN8DNP displayed 225-fold enhancement and LOD of 0.31 μM to H2S.•Probe HN8DNP was applied for imaging exogenous H2S and enzymatic H2S generation.
As a revolution in networking, the Internet of Things (IoT) aims at automating the operations of our societies by connecting and leveraging an enormous number of distributed devices (e.g., sensors ...and actuators). One design challenge is efficient wireless data aggregation (WDA) over the dense IoT devices. This can enable a series of the IoT applications ranging from latency-sensitive high-mobility sensing to data-intensive distributed machine learning. Over-the-air (function) computation (AirComp) has emerged to be a promising solution that merges computing and communication by exploiting analog-wave addition in the air. Another IoT design challenge is battery recharging for dense sensors which can be tackled by wireless power transfer (WPT). The coexisting of AirComp and WPT in the IoT system calls for their integration to enhance the performance and efficiency of WDA. This motivates the current work on developing the wirelessly powered AirComp (WP-AirComp) framework by jointly optimizing wireless power control, energy and (data) aggregation beamforming to minimize the AirComp error. To derive a practical solution, we recast the non-convex joint optimization problem into the equivalent outer and inner sub-problems for (inner) wireless power control and energy beamforming, and (outer) the efficient aggregation beamforming, respectively. The former is solved in closed form while the latter is efficiently solved using the semidefinite relaxation technique. The results reveal that the optimal energy beams point to the dominant Eigen-directions of the WPT channels, and the optimal power allocation tends to equalize the close-loop (down-link WPT and up-link AirComp) effective channels of different sensors. The simulation demonstrates that the controlling WPT provides additional design dimensions for substantially reducing the AirComp error.
Accumulating evidence suggests that M2-polarized tumor-associated macrophages (TAMs) play an important role in cancer progression and metastasis, making M2 polarization of TAMs an ever more appealing ...target for therapeutic intervention. Astragaloside IV (AS-IV), a saponin component isolated from Astragali radix, has been reported to inhibit the invasion and metastasis of lung cancer, but its effects on TAMs during lung cancer progression have not been investigated.
Human THP-1 monocytes were induced to differentiate into M2 macrophages through treatments with IL-4, IL-13, and phorbol myristate acetate (PMA). We used the lung cancer cell lines A549 and H1299 cultured in conditioned medium from M2 macrophages (M2-CM) to investigate the effects of AS-IV on tumor growth, invasion, migration, and angiogenesis of lung cancer cells. Macrophage subset distribution, M1 and M2 macrophage-associated markers, and mRNA expression were analyzed by flow cytometry and quantitative PCR. The activation of adenosine monophosphate-activated protein kinase (AMPK) signaling pathways that mediate M2-CM-promoted tumor migration was detected using western blotting.
Here we found that AS-IV significantly inhibited IL-13 and IL-4-induced M2 polarization of macrophages, as illustrated by reduced expression of CD206 and M2-associated genes, and that AS-IV suppressed the M2-CM-induced invasion, migration, and angiogenesis of A549 and H1299 cells. In vivo experiments demonstrated that AS-IV greatly inhibited tumor growth and reduced the number of metastases of Lewis lung cancer. The percentage of M2 macrophages was decreased in tumor tissue after AS-IV treatment. Furthermore, AS-IV inhibited AMPKα activation in M2 macrophages, and silencing of AMPKα partially abrogated the inhibitory effect of AS-IV.
AS-IV reduced the growth, invasion, migration, and angiogenesis of lung cancer by blocking the M2 polarization of macrophages partially through the AMPK signaling pathway, which appears to play an important role in AS-IV's ability to inhibit the metastasis of lung cancer.
Inflammasomes are large cytoplasmic complexes that sense microbial infections/danger molecules and induce caspase-1 activation-dependent cytokine production and macrophage inflammatory death. The ...inflammasome assembled by the NOD-like receptor (NLR) protein NLRC4 responds to bacterial flagellin and a conserved type III secretion system (TTSS) rod component. How the NLRC4 inflammasome detects the two bacterial products and the molecular mechanism of NLRC4 inflammasome activation are not understood. Here we show that NAIP5, a BIR-domain NLR protein required for Legionella pneumophila replication in mouse macrophages, is a universal component of the flagellin-NLRC4 pathway. NAIP5 directly and specifically interacted with flagellin, which determined the inflammasome-stimulation activities of different bacterial flagellins. NAIP5 engagement by flagellin promoted a physical NAIP5-NLRC4 association, rendering full reconstitution of a flagellin-responsive NLRC4 inflammasome in non-macrophage cells. The related NAIP2 functioned analogously to NAIP5, serving as a specific inflammasome receptor for TTSS rod proteins such as Salmonella PrgJ and Burkholderia BsaK. Genetic analysis of Chromobacterium violaceum infection revealed that the TTSS needle protein CprI can stimulate NLRC4 inflammasome activation in human macrophages. Similarly, CprI is specifically recognized by human NAIP, the sole NAIP family member in human. The finding that NAIP proteins are inflammasome receptors for bacterial flagellin and TTSS apparatus components further predicts that the remaining NAIP family members may recognize other unidentified microbial products to activate NLRC4 inflammasome-mediated innate immunity.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Thiacalix4arenes as a family of promising ligands have been widely used to construct polynuclear metal clusters, but scarcely employed in silver nanoclusters. Herein, an anion-templated Ag
...nanocluster (SD/Ag88a) built from p-tert-butylthiacalix4arene (H
TC4A) is reported. Single-crystal X-ray diffraction reveals that C
-symmetric SD/Ag88a resembles a metal-organic super calix comprised of eight TC4A
as walls and 88 silver atoms as base, which can be deconstructed to eight CrO
@Ag
(TC4A)(EtS)
(OAc) secondary building units arranged in an annulus encircling a CrO
in the center. Local and global anion template effects from chromates are individually manifested in SD/Ag88a. The solution stability and hierarchical assembly mechanism of SD/Ag88a are studied by using electrospray mass spectrometry. The Ag
nanocluster represents the highest nuclearity metal cluster capped by TC4A
. This work not only exemplify the specific macrocyclic effects of TC4A
in the construction of silver nanocluster but also realize the shape heredity of TC4A
to overall silver super calix.
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