83 research outputs found
Distributed Optimization for Second-Order Multi-Agent Systems with Dynamic Event-Triggered Communication
In this paper, we propose a fully distributed algorithm for second-order
continuous-time multi-agent systems to solve the distributed optimization
problem. The global objective function is a sum of private cost functions
associated with the individual agents and the interaction between agents is
described by a weighted undirected graph. We show the exponential convergence
of the proposed algorithm if the underlying graph is connected, each private
cost function is locally gradient-Lipschitz-continuous, and the global
objective function is restricted strongly convex with respect to the global
minimizer. Moreover, to reduce the overall need of communication, we then
propose a dynamic event-triggered communication mechanism that is free of Zeno
behavior. It is shown that the exponential convergence is achieved if the
private cost functions are also globally gradient-Lipschitz-continuous.
Numerical simulations are provided to illustrate the effectiveness of the
theoretical results
Conditional Attribute-Based Proxy Re-Encryption
Proxy re-encryption (PRE) is a cryptographic primitive that allows a semi-trusted proxy to transfer the decryption rights of ciphertexts in a secure and privacy-preserving manner. This versatile primitive has been extended to several powerful variants, leading to numerous applications, such as e-mail forwarding and content distribution. One such variant is attribute-based PRE (AB-PRE), which provides an expressible access control mechanism by allowing the proxy to switch the underlying policy of an attribute-based encryption (ABE) ciphertext. However, the function of AB-PRE is to convert the underlying policies of all ciphertexts indiscriminately, which lacks the flexibility of ciphertext transformation. Therefore, AB-PRE needs to support the property of conditional delegation. Among the other variants of PRE, there is a variant called conditional PRE (C-PRE), which allows fine-grained delegations by restricting the proxy to performing valid re-encryption only for a limited set of ciphertexts. Unfortunately, existing PRE schemes cannot simultaneously achieve expressible access control mechanisms and fine-grained delegations. Specifically, we require a PRE scheme, via which the proxy can convert the underlying policies of an ABE ciphertext only if this ciphertext is in the set of ciphertexts allowing the proxy to perform valid transformations.
To address this problem, we formalize the notion of conditional attribute-based PRE (CAB-PRE) in the honest re-encryption attacks (HRA) model, which is more robust and implies chosen-plaintext attacks (CPA) security, and propose the first CAB-PRE scheme. To construct such a scheme, we design as a building block, the first adaptively HRA-secure (ciphertext-policy) AB-PRE based on the learning with errors (LWE) problem. This scheme solves the open problem left by Susilo et al. in ESORICS\u2721 about how to construct an HRA-secure (ciphertext-policy) AB-PRE scheme, and it should be of independent interest. Then, we introduce a well-matched conditional delegation mechanism for this AB-PRE scheme to derive our adaptively HRA-secure CAB-PRE scheme
Attribute-Based Conditional Proxy Re-Encryption in the Standard Model under LWE
Attribute-based conditional proxy re-encryption (AB-CPRE) allows delegators to carry out attribute-based control on the delegation of decryption by setting policies and attribute vectors. The fine-grained control of AB-CPRE makes it suitable for a variety of applications, such as cloud storage and distributed file systems. However, all existing AB-CPRE schemes are constructed under classical number-theoretic assumptions, which are vulnerable to quantum cryptoanalysis. Therefore, we propose the first AB-CPRE scheme based on the learning with errors (LWE) assumption. Constructed from fully key-homomorphic encryption (FKHE) and key-switching techniques, our scheme is unidirectional, single-hop, and enables a polynomial-deep boolean circuit as its policy. Furthermore, we split the ciphertext into two independent parts to avoid two-level or multi-level encryption/decryption mechanisms. Taking advantage of it, we then extend our single-hop AB-CPRE into an efficient and concise multi-hop one. No matter how many transformations are performed, the re-encrypted ciphertext is in constant size, and only one encryption/decryption algorithm is needed. Both of our schemes are proved to be selective secure against chosen-plaintext attacks (CPA) in the standard model
Templated-Construction of Hollow MoS2 Architectures with Improved Photoresponses
: Despite the outstanding optoelectronic properties of MoS2 and its analogues, synthesis of such materials with desired features including fewer layers, arbitrary hollow structures, and particularly specifically customized morphologies, via inorganic reactions has always been challenging. Herein, using predesigned lanthanide-doped upconversion luminescent materials (e.g., NaYF4:Ln) as templates, arbitrary MoS2 hollow structures with precisely defined morphologies, widely variable dimensions, and very small shell thickness (≈2.5 nm) are readily constructed. Most importantly, integration of the near-infrared-responsive template significantly improves the photoresponse of up to 600 fold in device made of NaYF4:Yb/Er@MoS2 compared with that of MoS2 nanosheets under 980 nm laser illumination. Multichannel optoelectronic device is further fabricated by simply changing luminescent ions in the template, e.g., NaYF4:Er@MoS2, operating at 1532 nm light excitation with a 276-fold photoresponse enhancement. The simple chemistry, easy operation, high reliability, variable morphologies, and wide universality represent the most important advantages of this novel strategy that has not been accessed before
FACS-Based Genome-Wide CRISPR Screens Define Key Regulators of DNA Damage Signaling Pathways
DNA damage-activated signaling pathways are critical for coordinating multiple cellular processes, which must be tightly regulated to maintain genome stability. To provide a comprehensive and unbiased perspective of DNA damage response (DDR) signaling pathways, we performed 30 fluorescence-activated cell sorting (FACS)-based genome-wide CRISPR screens in human cell lines with antibodies recognizing distinct endogenous DNA damage signaling proteins to identify critical regulators involved in DDR. We discovered that proteasome-mediated processing is an early and prerequisite event for cells to trigger camptothecin- and etoposide-induced DDR signaling. Furthermore, we identified PRMT1 and PRMT5 as modulators that regulate ATM protein level. Moreover, we discovered that GNB1L is a key regulator of DDR signaling via its role as a co-chaperone specifically regulating PIKK proteins. Collectively, these screens offer a rich resource for further investigation of DDR, which may provide insight into strategies of targeting these DDR pathways to improve therapeutic outcomes
Knowledge atlas of antibody-drug conjugates on CiteSpace and clinical trial visualization analysis
ObjectiveAntibody-drugs conjugates (ADCs) are novel drugs with highly targeted and tumor-killing abilities and developing rapidly. This study aimed to evaluate drug discovery and clinical trials of and explore the hotspots and frontiers from 2012 to 2022 using bibliometric methods.MethodsPublications on ADCs were retrieved between 2012 and 2022 from Web of Science (WoS) and analyzed with CiteSpace 6.1.R2 software for the time, region, journals, institutions, etc. Clinical trials were downloaded from clinical trial.org and visualized with Excel software.ResultsA total of 696 publications were obtained and 187 drug trials were retrieved. Since 2012, research on ADCs has increased year by year. Since 2020, ADC-related research has increased dramatically, with the number of relevant annual publications exceeding 100 for the first time. The United States is the most authoritative and superior country and region in the field of ADCs. The University of Texas MD Anderson Cancer Center is the most authoritative institution in this field. Research on ADCs includes two clinical trials and one review, which are the most influential references. Clinical trials of ADCs are currently focused on phase I and phase II. Comprehensive statistics and analysis of the published literature and clinical trials in the field of ADCs, have shown that the most studied drug is brentuximab vedotin (BV), the most popular target is human epidermal growth factor receptor 2 (HER2), and breast cancer may become the main trend and hotspot for ADCs indications in recent years.ConclusionAntibody-drug conjugates have become the focus of targeted therapies in the field of oncology. The innovation of technology and combination application strategy will become the main trend and hotspots in the future
Association analysis between an epigenetic risk score and blood pressure
BACKGROUND: Epigenome-wide association studies have revealed multiple DNA methylation sites (CpGs) associated with alcohol consumption, an important lifestyle risk factor for cardiovascular diseases.RESULTS: We generated an alcohol consumption epigenetic risk score (ERS) based on previously reported 144 alcohol-associated CpGs and examined the association of the ERS with systolic blood pressure (SBP), diastolic blood pressure (DBP), and hypertension (HTN) in 3,898 Framingham Heart Study (FHS) participants. We found an association of alcohol intake with the ERS in the meta-analysis with 0.09 units higher ERS per drink consumed per day ( p < 0.0001). Cross-sectional analyses in FHS revealed that a one-unit increment of the ERS was associated with 1.93 mm Hg higher SBP ( p = 4.64E-07), 0.68 mm Hg higher DBP (p = 0.006), and an odds ratio of 1.78 for HTN ( p < 2E-16). Meta-analysis of the cross-sectional association of the ERS with BP traits in eight independent external cohorts (n = 11,544) showed similar relationships with blood pressure levels, i.e., a one-unit increase in ERS was associated with 0.74 ( p = 0.002) and 0.50 ( p = 0.0006) mm Hg higher SBP and DBP, but could not confirm the association with hypertension. Longitudinal analyses in FHS (n = 3,260) and five independent external cohorts (n = 4,021) showed that the baseline ERS was not associated with a change in blood pressure over time or with incident HTN. CONCLUSIONS: Our findings provide proof-of-concept that utilizing an ERS is a useful approach to capture the recent health consequences of lifestyle behaviors such as alcohol consumption.</p
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