141 research outputs found
Lifting Theorems Meet Information Complexity: Known and New Lower Bounds of Set-disjointness
Set-disjointness problems are one of the most fundamental problems in
communication complexity and have been extensively studied in past decades.
Given its importance, many lower bound techniques were introduced to prove
communication lower bounds of set-disjointness. Combining ideas from
information complexity and query-to-communication lifting theorems, we
introduce a density increment argument to prove communication lower bounds for
set-disjointness:
We give a simple proof showing that a large rectangle cannot be
-monochromatic for multi-party unique-disjointness.
We interpret the direct-sum argument as a density increment process and give
an alternative proof of randomized communication lower bounds for multi-party
unique-disjointness.
Avoiding full simulations in lifting theorems, we simplify and improve
communication lower bounds for sparse unique-disjointness.
Potential applications to be unified and improved by our density increment
argument are also discussed.Comment: Working Pape
Untargeted Safety Pharmacology Screen of Blood-Activating and Stasis-Removing Patent Chinese Herbal Medicines Identified Nonherbal Ingredients as a Cause of Organ Damage in Experimental Models
Blood activation and stasis removal from circulation is a central principle for treatment of syndromes related to cerebral and cardiovascular diseases in Chinese herbal medicine. However, blood-activating and stasis-removing patent Chinese herbal medicine (BASR-pCHM) widely used with or without prescription in China and elsewhere are highly variable in composition and manufacture standard, making their safety assessment a challenging task. We proposed that an integrated evaluation of multiple toxicity parameters of BASR-pCHM would provide critical reference and guidelines for their safe clinical application. Examination of standardized extracts from 58 compound BASR-pCHM in vivo in VEGFR2-luc mice and in vitro in cardiac, renal, and hepatic cells identified Naoluotong capsule (NLTC) as a potent organ/cell damage inducer. Composition analysis revealed that NLTC was the one that contained nonherbal ingredients among the BASR-pCHM collection. In vivo and in vitro experiments confirmed that NLTC, as well as its chemical supplement tolperisone hydrochloride, caused organ and cell damage by reducing cell viability, mitochondrial mass/activity, while the NLTC herbal components did not. Taken together, our study showed that safety evaluation of patent herbal medicines already on market is still necessary and urgently needed. In addition, chemical/herbal interactions should be considered as an important contributor of potential toxicity when evaluating the safety of herbal medicine
Joint Compression and Deadline Optimization for Wireless Federated Learning
Federated edge learning (FEEL) is a popular distributed learning framework
for privacy-preserving at the edge, in which densely distributed edge devices
periodically exchange model-updates with the server to complete the global
model training. Due to limited bandwidth and uncertain wireless environment,
FEEL may impose heavy burden to the current communication system. In addition,
under the common FEEL framework, the server needs to wait for the slowest
device to complete the update uploading before starting the aggregation
process, leading to the straggler issue that causes prolonged communication
time. In this paper, we propose to accelerate FEEL from two aspects: i.e., 1)
performing data compression on the edge devices and 2) setting a deadline on
the edge server to exclude the straggler devices. However, undesired gradient
compression errors and transmission outage are introduced by the aforementioned
operations respectively, affecting the convergence of FEEL as well. In view of
these practical issues, we formulate a training time minimization problem, with
the compression ratio and deadline to be optimized. To this end, an
asymptotically unbiased aggregation scheme is first proposed to ensure zero
optimality gap after convergence, and the impact of compression error and
transmission outage on the overall training time are quantified through
convergence analysis. Then, the formulated problem is solved in an alternating
manner, based on which, the novel joint compression and deadline optimization
(JCDO) algorithm is derived. Numerical experiments for different use cases in
FEEL including image classification and autonomous driving show that the
proposed method is nearly 30X faster than the vanilla FedAVG algorithm, and
outperforms the state-of-the-art schemes.Comment: 13 pages, accepted by IEEE Transactions on Mobile Computing (TMC
Synthesis and Electrochemical Performance of Polyacrylonitrile Carbon Nanostructure Microspheres for Supercapacitor Application
Polyacrylonitrile (PAN) carbon nanostructure microspheres (CNM) with the average particle size of 200 nm were prepared in the range of 500 to 800°C. The precursors of CNM were obtained through soap-free emulsion polymerization followed by freeze drying, oxidative stabilization, and half-carbonization. KOH was employed as the activation agent of the precursor material, and the ratio between KOH and the precursor was selected as 2 : 1. The element content, pore structure, nitrogen-containing functional groups, and microstructure characterization were characterized via elemental analysis, N2 adsorption at low temperature, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), and the electrochemical properties were examined as well. The results revealed that the CNM displayed specific surface area as high as 2134 m2/g and the total pore volume could reach 2.01 cm3/g when the activation temperature was 700°C. Furthermore, its specific capacitance in 3 M KOH and 1 M organic electrolyte could reach 311 F/g and 179 F/g, respectively. And, also, abundant functional groups of N-5 and N-6 were rich in the surface of the material, which could cause Faraday reaction and got the increasing specific capacitance via improvement of the wettability of the electrode material
Communication Lower Bounds of Key-Agreement Protocols via Density Increment Arguments
Constructing key-agreement protocols in the random oracle model (ROM) is a viable method to assess the feasibility of developing public-key cryptography within Minicrypt. Unfortunately, as shown by Impagliazzo and Rudich (STOC 1989) and Barak and Mahmoody (Crypto 2009), such protocols can only guarantee limited security: any -query protocol can be attacked by an -query adversary. This quadratic gap matches the key-agreement protocol proposed by Merkle (CACM 78), known as Merkle\u27s Puzzles.
Besides query complexity, the communication complexity of key-agreement protocols in the ROM is also an interesting question in the realm of find-grained cryptography, even though only limited security is achievable. Haitner et al. (ITCS 2019) first observed that in Merkle\u27s Puzzles, to obtain secrecy against an eavesdropper with queries, the honest parties must exchange bits. Therefore, they conjectured that high communication complexity is unavoidable, i.e., any -query protocols with bits of communication could be attacked by an -query adversary. This, if true, will suggest that Merkle\u27s Puzzle is also optimal regarding communication complexity. Building upon techniques from communication complexity, Haitner et al. (ITCS 2019) confirmed this conjecture for two types of key agreement protocols with certain natural properties.
This work affirms the above conjecture for all non-adaptive protocols with perfect completeness. Our proof uses a novel idea called density increment argument. This method could be of independent interest as it differs from previous communication lower bounds techniques (and bypasses some technical barriers)
Overexpression of Wnt7b antagonizes the inhibitory effect of dexamethasone on osteoblastogenesis of ST2 cells
Introduction: It is well established that glucocorticoid-induced osteoporosis is highly associated with preosteoblast differentiation and function. This study is based on the premise that Wnt7b can promote bone formation through Wnt signalling pathway because it can stimulate preosteoblast differentiation and increase its activity. However, it is unknown whether Wnt7b can rescue the inhibited osteoblast differentiation and function caused by exogenous glucocorticoid.
Material and methods: In this study we used Wnt7b overexpression ST2 cells to explore whether Wnt7bcan rescue the inhibited osteoblast differentiation and function, which can provide strong proof to investigate a new drug for curing the glucocorticoid induced osteoporosis.
Results/Conclusion: We found that Wnt7b can rescue the suppressed osteoblast differentiation and function without cell viability caused by dexamethasone
Supported monodisperse Pt nanoparticles from [Pt-3(CO)(3)(mu(2)-CO)(3)](5)(2-) clusters for investigating support-Pt interface effect in catalysis
MOST of China [2011CB932403]; NSFC [21131005, 21021061, 20925103, 20923004]; Fok Ying Tung Education Foundation [121011]Here we present a surfactant-free strategy to prepare supported monodisperse Pt nanoparticles from molecular [Pt-3(CO)(3)(mu(2)-CO)(3)](5)(2-) clusters. The strategy allows facile deposition of same-sized Pt nanoparticles on various oxide supports to unambiguously study the interface effect between noble metal and metal oxide in catalysis. In this study, Fe2O3 is demonstrated to be a superior support over TiO2, CeO2 and SiO2 to prepare highly active supported Pt nanoparticles for CO oxidation, which indicates that the interfaces between Pt and iron oxide are the active sites for O-2 activation and CO oxidation
Percutaneous cryoablation of subcapsular hepatocellular carcinoma: a retrospective study of 57 cases
PURPOSEThis study aims to evaluate the safety and effectiveness of the percutaneous cryoablation for subcapsular hepatocellular carcinoma (HCC).METHODSA total of 57 patients with subcapsular (<1 cm form the liver edge) HCCs (68 lesions), who were treated with CT-guided percutaneous cryoablation in the Department of Interventional Radiology of our hospital between July 1, 2016 and September 1, 2018, were retrospectively included. Complete ablation rate, local tumor progression (LTP) and treatment-related complications were evaluated. Furthermore, the degree of intraoperative and postoperative pain was measured with the visual analog scale (VAS), and laboratory findings were compared before and after the procedure.RESULTSAll patients successfully completed the treatment. The mean follow-up period was 12.8 months (range, 3–27 months), and the complete ablation rate was 97% (66/68). Local tumor progression occurred in 11 lesions (16.2%), and the 6-, 12- and 18-month cumulative LTP rates were 4.0%, 8.2% and 20.5%, respectively. Two patients (3.5%, 2/57) developed major complications, and 12 patients had minor complications (22.8%, 12/57). The mean VAS score during the operation was 1.65 points (range, 1–3 points). Postoperative pain worsened in 3 patients, and the VAS scores reached 4–5. Transient changes in biochemical and hematologic markers were observed.CONCLUSIONPercutaneous cryoablation for subcapsular HCC is safe and effective, the procedure is simple and the patients suffer less pain
Protection against acute cerebral ischemia/reperfusion injury by QiShenYiQi via neuroinflammatory network mobilization
Cerebral ischemia/reperfusion injury (CI/RI) is a common feature of ischemic stroke, involving a period of impaired blood supply to the brain, followed by the restoration of cerebral perfusion through medical intervention. Although ischemia and reperfusion brain damage is a complex pathological process with an unclear physiological mechanism, more attention is currently focused on the neuroinflammatory response of an ischemia/reperfusion origin, and anti-inflammatory appears to be a potential therapeutic strategy following ischemic stroke. QiShenYiQi (QSYQ), a component-based Chinese medicine with Qi-tonifying and blood-activating property, has pharmacological actions of anti-inflammatory, antioxidant, mitochondrial protectant, anti-apoptosis, and antiplatelet aggregation. We have previously reported that the cardioprotective effect of QSYQ against ischemia/reperfusion injury is via improvement of mitochondrial functional integrity. In this research work, we aimed to investigate the possible mechanism involved in the neuroprotection of QSYQ in mice model of cerebral ischemia/reperfusion injury based on the inflammatory pathway. The cerebral protection was evaluated in the stroke mice after 24 h reperfusion by assessing the neurological deficit, cerebral infarction, brain edema, BBB functionality, and via histopathological assessment. TCM-based network pharmacology method was performed to establish and analyze compound-target-disease & function-pathway network so as to find the possible mechanism linking to the role of QSYQ in CI/RI. In addition, RT-qPCR was used to verify the accuracy of predicted signaling gene expression. As a result, improvement of neurological outcome, reduction of infarct volume and brain edema, a decrease in BBB disruption, and amelioration of histopathological alteration were observed in mice pretreated with QSYQ after experimental stroke surgery. Network pharmacology analysis revealed neuroinflammatory response was associated with the action of QSYQ in CI/RI. RT-qPCR data showed that the mice pretreated with QSYQ could significantly decrease IFNG-γ, IL-6, TNF-α, NF-κB p65, and TLR-4 mRNA levels and increase TGF-β1 mRNA level in the brain compared to the untreated mice after CI/RI (p \u3c 0.05). In conclusion, our study indicated the cerebral protective effect of pretreatment with QSYQ against CI/RI, which may be partly related to its potential to the reduction of neuroinflammatory response in a stroke subject
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