220 research outputs found
Strong dopant dependence of electric transport in ion-gated MoS2
We report modifications of the temperature-dependent transport properties of
thin flakes via field-driven ion intercalation in an electric
double layer transistor. We find that intercalation with ions
induces the onset of an inhomogeneous superconducting state. Intercalation with
leads instead to a disorder-induced incipient metal-to-insulator
transition. These findings suggest that similar ionic species can provide
access to different electronic phases in the same material.Comment: 5 pages, 3 figure
Enzyme-linked immunospot assay response to recombinant CFP-10/ESAT-6 fusion protein among patients with spinal tuberculosis: implications for diagnosis and monitoring of surgical therapy
SummaryObjectiveThis study aimed to assess the performance of a laboratory-developed recombinant CFP-10/ESAT-6 fusion protein (rCFP-10/ESAT-6)-based enzyme-linked immunospot (ELISPOT) assay for the diagnosis of spinal tuberculosis (TB) in China, and to evaluate the value of the ELISPOT assay for monitoring the efficacy of surgical treatment.MethodsIn the first part of the study, a total of 78 participants were consecutively recruited for ELISPOT using rCFP-10/ESAT-6 as a stimulus. The cutoff value for ELISPOT positivity was based on the results of receiver operating characteristic curve analysis. In the second part, this approach was evaluated in a prospective study including 102 patients with suspected spinal TB. Data on clinical characteristics of the patients and conventional laboratory results were collected, and blood samples were obtained for ELISPOT using rCFP-10/ESAT-6 as a stimulus.ResultsAmong the 102 patients with suspected spinal TB, 11 were excluded from the study. Twenty-three patients (25.2%) had culture-confirmed TB and 29 (31.9%) patients had probable TB. Among the spinal TB patients, the ELISPOT had a sensitivity of 82.7%, compared to a sensitivity of 61.5% for the purified protein derivative (PPD) skin test. The specificity was 87.2% for ELISPOT and 46.2% for the PPD skin test among 39 subjects with non-TB disease. The number of spot-forming cells and/or the positive rate of the ELISPOT assay were associated with aging, emaciation, and paravertebral abscess. The number of subjects with responses to rCFP-10/ESAT-6 slightly decreased after surgical treatment in spinal TB patients.ConclusionsA laboratory-developed rCFP-10/ESAT-6 ELISPOT assay is a useful adjunct to current tests for the diagnosis of spinal TB
Possible charge-density-wave signatures in the anomalous resistivity of Li-intercalated multilayer MoS2
We fabricate ion-gated field-effect transistors (iFET) on mechanically
exfoliated multilayer MoS. We encapsulate the flake by AlO, leaving
the device channel exposed at the edges only. A stable Li intercalation in
the MoS lattice is induced by gating the samples with a Li-based polymeric
electrolyte above 330 K and the doping state is fixed by quenching the
device to 300 K. This intercalation process induces the emergence of
anomalies in the temperature dependence of the sheet resistance and its first
derivative, which are typically associated with structural/electronic/magnetic
phase transitions. We suggest that these anomalies in the resistivity of
MoS can be naturally interpreted as the signature of a transition to a
charge-density-wave phase induced by lithiation, in accordance with recent
theoretical calculations.Comment: 8 pages, 4 figure
Front-running Attack in Sharded Blockchains and Fair Cross-shard Consensus
Sharding is a prominent technique for scaling blockchains. By dividing the
network into smaller components known as shards, a sharded blockchain can
process transactions in parallel without introducing inconsistencies through
the coordination of intra-shard and cross-shard consensus protocols. However,
we observe a critical security issue with sharded systems: transaction ordering
manipulations can occur when coordinating intra-shard and cross-shard consensus
protocols, leaving the system vulnerable to attack. Specifically, we identify a
novel security issue known as finalization fairness, which can be exploited
through a front-running attack. This attack allows an attacker to manipulate
the execution order of transactions, even if the victim's transaction has
already been processed and added to the blockchain by a fair intra-shard
consensus.
To address the issue, we offer Haechi, a novel cross-shard protocol that is
immune to front-running attacks. Haechi introduces an ordering phase between
transaction processing and execution, ensuring that the execution order of
transactions is the same as the processing order and achieving finalization
fairness. To accommodate different consensus speeds among shards, Haechi
incorporates a finalization fairness algorithm to achieve a globally fair order
with minimal performance loss. By providing a global order, Haechi ensures
strong consistency among shards, enabling better parallelism in handling
conflicting transactions across shards. These features make Haechi a promising
solution for supporting popular smart contracts in the real world. To evaluate
Haechi's performance, we implemented the protocol using Tendermint and
conducted extensive experiments on a geo-distributed AWS environment. Our
results demonstrate that Haechi achieves finalization fairness with little
performance sacrifice compared to existing cross-shard consensus protocols
Effect of Diet Supplemented With Rapeseed Meal or Hydrolysable Tannins on the Growth, Nutrition, and Intestinal Microbiota in Grass Carp (Ctenopharyngodon idellus)
Grass carp (Ctenopharyngodon idellus; n = 320) were received four different diets for 56 days. The experimental diets were: fishmeal (FM) containing 10% fishmeal (without rapeseed meal), and rapeseed meal (RM) containing 50% rapeseed meal (without fishmeal), and two semi-purified diets either without (T0) or with 1.25% (T1) supplemental hydrolysable tannin. The approximate content of tannin in the RM diet was 1.31%, which was close to that of T1, while the tannin content of FM was close to that of T0. The weight gain rate of grass carp of the RM group was significantly lower than that of the FM group, while the feeding conversion ratio and the feeding rate were significantly higher in the T1 group than in T0. The muscle lipid content was significantly lower in RM than in FM, while T1 was lower than T0. Intestinal activities of trypsin and α-amylase were significantly higher in T1 and RM groups compared with the other treatments. The hepatic activities of aspartate aminotransferase and alanine aminotransferase were lower in T1 and RM groups compared with the other treatments, while hepatic glycogen, and malonaldehyde were significantly higher in T1 and RM groups. In serum, the total protein and globulin contents were significantly higher in T1 and RM groups, while albumin was significantly lower in the RM group compared to the FM group. High-throughput sequencing showed that Proteobacteria, Firmicutes, and Actinobacteria were the dominant bacterial phyla among groups. The intestinal microbial diversity was higher in T1 and RM. Redundancy analysis showed that tannin, rapeseed meal, and intestinal trypsin activity were positively or negatively correlated with the relative abundance of several different intestinal microbiota at phylum and/or genus levels. The results indicated that 1.25% tannin could not be the main reason for the poor growth of grass carp of the RM group; however, the protein metabolism was disturbed, the absorption of carbohydrate was improved, and the accumulation of lipid had decreased. Furthermore, tannin and rapeseed meal supplementations modulated the intestinal microbiota, and may sequentially regulate the intestinal function by fermenting dietary nutrition, producing digestive enzymes, and modulating probiotics
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