52 research outputs found
SGDP: A Stream-Graph Neural Network Based Data Prefetcher
Data prefetching is important for storage system optimization and access
performance improvement. Traditional prefetchers work well for mining access
patterns of sequential logical block address (LBA) but cannot handle complex
non-sequential patterns that commonly exist in real-world applications. The
state-of-the-art (SOTA) learning-based prefetchers cover more LBA accesses.
However, they do not adequately consider the spatial interdependencies between
LBA deltas, which leads to limited performance and robustness. This paper
proposes a novel Stream-Graph neural network-based Data Prefetcher (SGDP).
Specifically, SGDP models LBA delta streams using a weighted directed graph
structure to represent interactive relations among LBA deltas and further
extracts hybrid features by graph neural networks for data prefetching. We
conduct extensive experiments on eight real-world datasets. Empirical results
verify that SGDP outperforms the SOTA methods in terms of the hit ratio by
6.21%, the effective prefetching ratio by 7.00%, and speeds up inference time
by 3.13X on average. Besides, we generalize SGDP to different variants by
different stream constructions, further expanding its application scenarios and
demonstrating its robustness. SGDP offers a novel data prefetching solution and
has been verified in commercial hybrid storage systems in the experimental
phase. Our codes and appendix are available at
https://github.com/yyysjz1997/SGDP/
Alpha-Synuclein Disrupted Dopamine Homeostasis Leads to Dopaminergic Neuron Degeneration in Caenorhabditis elegans
This is the publisher's version, also available electronically from http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0009312Disruption of dopamine homeostasis may lead to dopaminergic neuron degeneration, a proposed explanation for the specific vulnerability of dopaminergic neurons in Parkinson's disease. While expression of human α-synuclein in C. elegans results in dopaminergic neuron degeneration, the effects of α-synuclein on dopamine homeostasis and its contribution to dopaminergic neuron degeneration in C. elegans have not been reported. Here, we examined the effects of α-synuclein overexpression on worm dopamine homeostasis. We found that α-synuclein expression results in upregulation of dopamine synthesis and content, and redistribution of dopaminergic synaptic vesicles, which significantly contribute to dopaminergic neuron degeneration. These results provide in vivo evidence supporting a critical role for dopamine homeostasis in supporting dopaminergic neuron integrity
(Li0.84Fe0.16)OHFe0.98Se superconductor: Ion-exchange synthesis of large single crystal and highly two-dimensional electron properties
A large and high-quality single crystal (Li0.84Fe0.16)OHFe0.98Se, the optimal
superconductor of newly reported (Li1-xFex)OHFe1-ySe system, has been
successfully synthesized via a hydrothermal ion-exchange technique. The
superconducting transition temperature (Tc) of 42 K is determined by magnetic
susceptibility and electric resistivity measurements, and the zero-temperature
upper critical magnetic fields are evaluated as 79 and 313 Tesla for the field
along the c-axis and the ab-plane, respectively. The ratio of out-of-plane to
in-plane electric resistivity,\r{ho}c/\r{ho}ab, is found to increases with
decreasing temperature and to reach a high value of 2500 at 50 K, with an
evident kink occurring at a characteristic temperature T*=120 K. The negative
in-plane Hall coefficient indicates that electron carriers dominate in the
charge transport, and the hole contribution is significantly reduced as the
temperature is lowered to approach T*. From T* down to Tc, we observe the
linear temperature dependences of the in-plane electric resistivity and the
magnetic susceptibility for the FeSe layers. Our findings thus reveal that the
normal state of (Li0.84Fe0.16)OHFe0.98Se becomes highly two-dimensional and
anomalous prior to the superconducting transition, providing a new insight into
the mechanism of high-Tc superconductivity.Comment: 11 pages, 4 figures, supplementary information is not uploade
Small Molecule Inhibitors of 15-PGDH Exploit a Physiologic Induced-Fit Closing System
15-prostaglandin dehydrogenase (15-PGDH) is a negative regulator of tissue stem cells that acts via enzymatic activity of oxidizing and degrading PGE2, and related eicosanoids, that support stem cells during tissue repair. Indeed, inhibiting 15-PGDH markedly accelerates tissue repair in multiple organs. Here we have used cryo-electron microscopy to solve the solution structure of native 15-PGDH and of 15-PGDH individually complexed with two distinct chemical inhibitors. These structures identify key 15-PGDH residues that mediate binding to both classes of inhibitors. Moreover, we identify a dynamic 15-PGDH lid domain that closes around the inhibitors, and that is likely fundamental to the physiologic 15-PGDH enzymatic mechanism. We furthermore identify two key residues, F185 and Y217, that act as hinges to regulate lid closing, and which both inhibitors exploit to capture the lid in the closed conformation, thus explaining their sub-nanomolar binding affinities. These findings provide the basis for further development of 15-PGDH targeted drugs as therapeutics for regenerative medicine
Efficacy and safety of acupuncture-point stimulation combined with opioids for the treatment of moderate to severe cancer pain: a network meta-analysis of randomized controlled trials
BackgroundPain is one of the most common and troublesome symptoms of cancer. Although potential positive effects of acupuncture-point stimulation (APS) on cancer pain have been observed, knowledge regarding the selection of the optimal APS remains unclear because of a lack of evidence from head-to-head randomized controlled trials (RCTs).ObjectiveThis study aimed to carry out a network meta-analysis to compare the efficacy and safety of different APS combined with opioids in treating moderate to severe cancer pain and rank these methods for practical consideration.MethodsA comprehensive search of eight electronic databases was conducted to obtain RCTs involving different APS combined with opioids for moderate to severe cancer pain. Data were screened and extracted independently using predesigned forms. The quality of RCTs was appraised with the Cochrane Collaboration risk-of-bias tool. The primary outcome was the total pain relief rate. Secondary outcomes were the total incidence of adverse reactions, the incidence of nausea and vomiting, and the incidence of constipation. We applied a frequentist, fixed-effect network meta-analysis model to pool effect sizes across trials using rate ratios (RR) with their 95% confidence intervals (CI). Network meta-analysis was performed using Stata/SE 16.0.ResultsWe included 48 RCTs, which consisted of 4,026 patients, and investigated nine interventions. A network meta-analysis showed that a combination of APS and opioids was superior in relieving moderate to severe cancer pain and reducing the incidence of adverse reactions such as nausea, vomiting, and constipation compared to opioids alone. The ranking of total pain relief rates was as follows: fire needle (surface under the cumulative ranking curve (SUCRA) = 91.1%), body acupuncture (SUCRA = 85.0%), point embedding (SUCRA = 67.7%), auricular acupuncture (SUCRA = 53.8%), moxibustion (SUCRA = 41.9%), transcutaneous electrical acupoint stimulation (TEAS) (SUCRA = 39.0%), electroacupuncture (SUCRA = 37.4%), and wrist–ankle acupuncture (SUCRA = 34.1%). The ranking of total incidence of adverse reactions was as follows: auricular acupuncture (SUCRA = 23.3%), electroacupuncture (SUCRA = 25.1%), fire needle (SUCRA = 27.2%), point embedding (SUCRA = 42.6%), moxibustion (SUCRA = 48.2%), body acupuncture (SUCRA = 49.8%), wrist–ankle acupuncture (SUCRA = 57.8%), TEAS (SUCRA = 76.3%), and opioids alone (SUCRA = 99.7%).ConclusionsAPS seemed to be effective in relieving cancer pain and reducing opioid-related adverse reactions. Fire needle combined with opioids may be a promising intervention to reduce moderate to severe cancer pain as well as reduce opioid-related adverse reactions. However, the evidence was not conclusive. More high-quality trials investigating the stability of evidence levels of different interventions on cancer pain must be conducted.Systematic Review Registrationhttps://www.crd.york.ac.uk/PROSPERO/#searchadvanced, identifier CRD42022362054
Application of a tracing experiment in the prediction of water and mud inrush in the Wantan Tunnel
Taking the Wantan Tunnel of Yilai Highway as the study case, the average water inflow and the water inflow in the wet season of the tunnel are calculated through field investigation, groundwater tracer experiment, groundwater flow monitoring, and atmospheric rainfall infiltration method. Meanwhile, the realistic failure process analysis(RFPA) is used to analyze the possibility of tunnel water inrush is judged. The results of field survey and tracer test show that the karst pipeline of Wantan Tunnel is a multi-branched, mixed-type karst pipeline with complicated hydrogeological conditions. The water inflow in wet season is about 4.6 times of the average tunnel water inflow. Mud failure will go through the stages of crack initiation, crack expansion, further crack expansion, and through-through failure. At the same time, when the water flow at the karst pipeline reaches about 2.7 to 3.5 times the initial value (37 248 m3/d), water gushing and mud inrush damage will occur, that is, when the flow of water outlet 2 reaches 10 000 to 13 000 m3/d, There is a very high risk of water and mud gushing in the Wantan Tunnel
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