92 research outputs found
Lag synchronization of switched neural networks via neural activation function and applications in image encryption
This paper investigates the problem of global exponential lag synchronization of a class of switched neural networks with time-varying delays via neural activation function and applications in image encryption. The controller is dependent on the output of the system in the case of packed circuits, since it is hard to measure the inner state of the circuits. Thus, it is critical to design the controller based on the neuron activation function. Comparing the results, in this paper, with the existing ones shows that we improve and generalize the results derived in the previous literature. Several examples are also given to illustrate the effectiveness and potential applications in image encryption
Development and Fidelity Evaluation of a Skeletal Ethylene Mechanism under Scramjet-Relevant Conditions
As
one of the major short chain hydrocarbons resulting from the
cracking process, ethylene is often used as a surrogate for cracked
kerosene. In this study, a skeletal mechanism of ethylene was developed
under the typical working conditions of scramjet combustors. The skeletal
mechanism was reduced from a fully verified detailed mechanism under
the desired working conditions. An integrated reducing method containing
directed relation graph with error propagation method (DRGEP), sensitivity
analysis (SA), and computational singular perturbation (CSP) was employed
to obtain three skeletal mechanisms. A three-level fidelity validation
of the skeletal mechanisms respectively comparing the kinetic properties,
the global combustor performance, and the detailed flame structure
was proposed to comprehensively evaluate the skeletal mechanisms.
In the first-level fidelity validation, the three skeletal mechanisms
all show good agreement with the detailed one in the autoignition
delay and laminar flame speed over a wide range of working conditions.
Then in the second-level fidelity validation, the smallest mechanism
consisting of 24 species and 86 reactions (24S/86R) was further validated
through incorporating with the large eddy simulation of a realistic
scramjet combustor. Comparisons with the experimental data and the
predictions by the detailed mechanism show that the global combustor
performance (e.g., pressure, Mach number, and combustion efficiency)
was accurately predicted by the 24S/86R mechanism. In the third-level
fidelity evaluation, the flame structure characterized by the distribution
of CO, OH, and heat release rate was analyzed through comparing the
predictions by the 24S/86R mechanism with those by the detailed one
during which the insufficiency of the skeletal mechanism was also
recognized
Additional file 1 of Association between hyperglycemia on admission and preoperative deep venous thrombosis in patients with femoral neck fractures
Additional file1: eFigure 1. Flow chart of enrollment. eTable 1. Multivariate Analysis for preoperative deep venous thrombosis. eTable 2. Patient Characteristics Before and After Propensity Score Matching by Glucose Level (≥6.10 mmol/L and 6.60] mmol/L)
DataSheet_1_Identification of therapeutic targets and prognostic biomarkers in cholangiocarcinoma via WGCNA.zip
BackgroundCholangiocarcinoma (CCA) is a highly aggressive malignant tumor for which limited treatment methods and prognostic signatures are available. This study aims to identify potential therapeutic targets and prognostic biomarkers for CCA.MethodsBased on differentially expressed genes (DEGs) identified from The Cancer Genome Atlas (TCGA) data, our study identified key gene modules correlated with CCA patient survival by weighted gene coexpression network analysis (WGCNA). Cox regression analysis identified survival-related genes in the key gene modules. The biological properties of the survival-related genes were evaluated by CCK-8 and transwell assays. Then, these genes were used to construct a prognostic signature that was internally and externally validated. Additionally, by combining clinical characteristics with the gene−based prognostic signature, a nomogram for survival prediction was built.ResultsWGCNA divided the 1531 DEGs into four gene modules, and the yellow gene module was significantly associated with overall survival (OS) and histologic neoplasm grade. Our study identified the lncRNA AGAP2−AS1 and a novel gene, GOLGA7B, that are closely related to survival. GOLGA7B downregulation promoted the invasion, migration and proliferation of CCA cells, but AGAP2−AS1 had the opposite effect. AGAP2−AS1 and GOLGA7B were integrated into a gene−based prognostic signature, and both internal and external validation studies confirmed that this two-gene prognostic signature and nomogram could accurately predict CCA patient prognosis.ConclusionAGAP2−AS1 and GOLGA7B are potential therapeutic targets and prognostic biomarkers for CCA.</p
Salt effects on the rates of a thiol cyclisation reaction within a yocto-litre inner-space
The appreciation of the central role of Coulombic interactions in enzyme catalysis has led to the development of many ‘spin-off’ strategies for controlling chemical reactions. In particular, supramolecular chemistry has become increasingly proficient in using encapsulation/compartmentalisation to control both stoichiometric and catalytic reactions within the inner-spaces of hosts. This noted, there are still many open questions around the design of electrostatic potential fields within such hosts, and how exogenous factors can be used to fine-tune these properties. Here, we report on the cyclisation of 12-bromododecane-1-thiol 2 inside supramolecular capsule 12 to give thiacyclotridecane 3, and how the rate of this reaction changes as a function of exogenous salts. We find that this cyclisation is slowed in the presence of exogenous anions, with attenuation being highly dependent on both their nature and concentration. Thus, this work demonstrates how anions at the more-weakly solvated end of the Hofmeister series can associate with the outer walls of the capsule and so attenuate cyclisation. This suggests new ways in which reactions in inner-spaces can be indirectly modulated by exogeneous chemical entities.</p
Numerical Investigation on Flame Stabilization in DLR Hydrogen Supersonic Combustor with Strut Injection
<p>Flame stabilization in the DLR hydrogen supersonic combustor with strut injection was numerically investigated by using an in-house large eddy simulation code developed on the OpenFoam platform. To facilitate the comparison and analysis of various hydrogen oxidation mechanisms with different levels of mechanism reduction, the proposed 2D calculation model was validated against both the 3D simulation and the experimental data. The results show that the 2D model can capture the DLR flow and combustion characteristics with satisfactorily quantitative accuracy and significantly less computational load. By virtue of the flow visualization and the analyses of species evolution and heat release, the supersonic combustion in the DLR combustor can be divided into three stages along the streamwise direction: the induction stage where ignition occurs and active radicals are produced, the transition stage through which radicals are advected to the downstream, and the intense combustion stage where most heat release occurs. Furthermore, the sensitivity analysis of key reaction steps identifies the important role of chain carrying and heat release reactions in numerically reproducing the three-stage combustion stabilization mode in the DLR combustor.</p
Rare-Earth-Metal Complexes Supported by New Chiral Tetra-Azane Chelating Ligands: Synthesis, Characterization, and Catalytic Properties for Intramolecular Asymmetric Hydroamination
A number of new chiral tetra-azane proligands (1<i>R</i>,2<i>R</i>)-<i>N</i>,<i>N</i>′-bisÂ(<i>o</i>-arylamino-benzylidene)-1,2-diaminocyclohexane
((1<i>R</i>,2<i>R</i>)-[(ArHN)ÂC<sub>6</sub>H<sub>4</sub>CHî—»N]<sub>2</sub>C<sub>6</sub>H<sub>10</sub>, Ar =
2,6-Me<sub>2</sub>C<sub>6</sub>H<sub>3</sub> (<b>L</b><sup><b>1</b></sup>H<sub>2</sub>), 2,6-Et<sub>2</sub>C<sub>6</sub>H<sub>3</sub> (<b>L</b><sup><b>2</b></sup>H<sub>2</sub>), 2,6-<sup><i>i</i></sup>Pr<sub>2</sub>C<sub>6</sub>H<sub>3</sub> (<b>L</b><sup><b>3</b></sup>H<sub>2</sub>)) have been synthesized
via a nucleophilic displacement of the two fluorine atoms in (<i>o</i>-C<sub>6</sub>H<sub>4</sub>FCHî—»N)<sub>2</sub>C<sub>6</sub>H<sub>10</sub> with the lithium salt of the corresponding
aniline derivative. Their rare-earth-metal complexes <b>L</b><sup><b>1</b></sup>ScCl<sub>2</sub>LiÂ(THF)<sub>3</sub> (<b>1</b>), <b>L</b><sup><b>1</b></sup>YCl<sub>2</sub>LiÂ(THF)<sub>3</sub> (<b>2</b>), <b>L</b><sup><b>2</b></sup>YCl<sub>2</sub>LiÂ(THF)<sub>3</sub> (<b>3</b>), and <b>L</b><sup><b>3</b></sup>YCl<sub>2</sub>LiÂ(THF)<sub>2</sub> (<b>4</b>) were synthesized in good yields via the salt metathesis
of MCl<sub>3</sub> (M = Sc, Y) with the dilithium salts of the ligands <b>L</b><sup><b>1</b></sup>Li<sub>2</sub>(THF)<sub>4</sub>, <b>L</b><sup><b>2</b></sup>Li<sub>2</sub>(THF),<sub>4</sub>, and <b>L</b><sup><b>3</b></sup>Li<sub>2</sub>(THF)<sub>4</sub>, respectively. Further more, the two diethylamido complexes <b>L</b><sup><b>1</b></sup>YÂ(NEt<sub>2</sub>)ÂClLiÂ(THF)<sub>3</sub> (<b>5</b>) and <b>L</b><sup><b>3</b></sup>YÂ(NEt<sub>2</sub>)ÂClLiÂ(THF)<sub>2</sub> (<b>6</b>) were also
synthesized from reactions of the corresponding chloride complexes <b>2</b> and <b>4</b> with diethylamidolithium. The new proligands <b>L</b><sup><b>1</b></sup>H<sub>2</sub>–<b>L</b><sup><b>3</b></sup>H<sub>2</sub> and their rare-earth-metal
complexes <b>1</b>–<b>6</b> have been characterized
by elemental analyses and <sup>1</sup>H and <sup>13</sup>C NMR spectroscopy.
The structures of complexes <b>1</b>, <b>2</b>, and <b>4</b> have been further confirmed by single-crystal X-ray diffraction
analysis. The molecular structural analysis reveals that the metal
centers in complexes <b>1</b>, <b>2</b>, and <b>4</b> acquire a distorted-octahedral coordination environment in their
solid-state structures by sharing the chloride with a LiClÂ(THF)<sub><i>n</i></sub> moiety. After in situ treatment with <sup><i>n</i></sup>BuLi or Me<sub>3</sub>SiCH<sub>2</sub>Li,
complexes <b>1</b>–<b>4</b> show reasonable catalytic
activity and good enantioselectivity (up to 90%) for intramolecular
asymmetric hydroamination reactions of terminal aminoalkenes. The
amido complexes <b>5</b> and <b>6</b> can catalyze the
intramolecular hydroamination reaction directly and show catalytic
activities and enantioselectivities similar to those of the in situ
formed alkyl complexes
Data_Sheet_2_Risk factors for urinary tract infection in geriatric hip fracture patients: a systematic review and meta-analysis.docx
BackgroundUrinary tract infection (UTI) is a prevalent and consequential complication in hip fracture patients, leading to significant disability and heightened healthcare expenditures. Consequently, there is a critical need for a comprehensive systematic review to identify risk factors and establish early and effective preventive measures.MethodsA comprehensive search was performed across the PubMed, Cochrane, Embase, Web of Science, and Scopus databases (up to August 31, 2023). Article screening, data extraction, and quality assessment were independently completed by two reviewers.ResultsForty-four studies were eligible for inclusion, yielding an overall incidence rate of 11% (95% CI: 8%−14%). Our pooled analysis revealed 18 significant risk factors, including being female (OR = 2.23, 95% CI: 1.89–2.63), advanced age (MD = 1.35, 95% CI: 0.04–2.66), obesity (OR = 1.21, 95% CI: 1.11–1.31), catheterization (OR = 3.8, 95% CI: 2.29–6.32), blood transfusion (OR = 1.39, 95% CI: 1.21–1.58), American Society of Anesthesiologists ≥III (OR = 1.28, 95% CI: 1.18–1.40), general anesthesia (OR = 1.26, 95% CI: 1.11–1.43), intertrochanteric fracture (OR = 1.25, 95% CI: 1.01–1.54), hemiarthroplasty (OR = 1.43, 95% CI: 1.19–1.69), prolonged length of hospital stay (MD = 1.44, 95% CI: 0.66–2.23), delirium (OR = 2.66, 95% CI: 2.05–3.47), dementia (OR = 1.82, 95% CI: 1.62–2.06), Parkinson's disease (OR = 1.53, 95% CI: 1.46–1.61), diabetes (OR = 1.27, 95% CI: 1.13–1.43), hypertension (OR = 1.14, 95% CI: 1.03–1.26), congestive heart failure (OR = 1.35, 95% CI: 1.10–1.66), history of sepsis (OR = 7.13, 95% CI: 5.51–9.22), and chronic steroid use (OR = 1.29, 95% CI: 1.06–1.57).ConclusionOur study identifies numerous risk factors strongly associated with UTI, offering compelling evidence and actionable strategies for improving clinical prediction, enabling early intervention, and facilitating targeted UTI management.Systematic review registrationidentifier [CRD42023459600], https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=459600.</p
Data_Sheet_4_Risk factors for urinary tract infection in geriatric hip fracture patients: a systematic review and meta-analysis.docx
BackgroundUrinary tract infection (UTI) is a prevalent and consequential complication in hip fracture patients, leading to significant disability and heightened healthcare expenditures. Consequently, there is a critical need for a comprehensive systematic review to identify risk factors and establish early and effective preventive measures.MethodsA comprehensive search was performed across the PubMed, Cochrane, Embase, Web of Science, and Scopus databases (up to August 31, 2023). Article screening, data extraction, and quality assessment were independently completed by two reviewers.ResultsForty-four studies were eligible for inclusion, yielding an overall incidence rate of 11% (95% CI: 8%−14%). Our pooled analysis revealed 18 significant risk factors, including being female (OR = 2.23, 95% CI: 1.89–2.63), advanced age (MD = 1.35, 95% CI: 0.04–2.66), obesity (OR = 1.21, 95% CI: 1.11–1.31), catheterization (OR = 3.8, 95% CI: 2.29–6.32), blood transfusion (OR = 1.39, 95% CI: 1.21–1.58), American Society of Anesthesiologists ≥III (OR = 1.28, 95% CI: 1.18–1.40), general anesthesia (OR = 1.26, 95% CI: 1.11–1.43), intertrochanteric fracture (OR = 1.25, 95% CI: 1.01–1.54), hemiarthroplasty (OR = 1.43, 95% CI: 1.19–1.69), prolonged length of hospital stay (MD = 1.44, 95% CI: 0.66–2.23), delirium (OR = 2.66, 95% CI: 2.05–3.47), dementia (OR = 1.82, 95% CI: 1.62–2.06), Parkinson's disease (OR = 1.53, 95% CI: 1.46–1.61), diabetes (OR = 1.27, 95% CI: 1.13–1.43), hypertension (OR = 1.14, 95% CI: 1.03–1.26), congestive heart failure (OR = 1.35, 95% CI: 1.10–1.66), history of sepsis (OR = 7.13, 95% CI: 5.51–9.22), and chronic steroid use (OR = 1.29, 95% CI: 1.06–1.57).ConclusionOur study identifies numerous risk factors strongly associated with UTI, offering compelling evidence and actionable strategies for improving clinical prediction, enabling early intervention, and facilitating targeted UTI management.Systematic review registrationidentifier [CRD42023459600], https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=459600.</p
Data_Sheet_1_Association between preoperative albumin levels and postoperative delirium in geriatric hip fracture patients.docx
ObjectiveThis study aims to examine the association between preoperative serum albumin levels and postoperative delirium (POD) in geriatric patients who have undergone hip fracture surgery, with the goal of offering novel insights for clinical interventions targeting POD.MethodsA retrospective analysis was conducted on the medical records of patients who underwent hip fracture surgery in a tertiary medical institution from January 2013 to November 2023. The patients were classified based on hypoalbuminemia (defined as a serum albumin level ResultsThe retrospective cohort study included 1,440 patients, with an incidence of POD found to be 19.1%. In a multivariable logistic regression analysis, patients with hypoalbuminemia had an adjusted OR of 2.99 (95%CI: 2.14–4.18) compared to those with normal albumin levels (≥ 35 g/L). Furthermore, a significant trend was observed across different severity categories, including mild hypoalbuminemia (34.9–30.0 g/L; adjusted OR = 2.71, 95%CI: 1.84–3.99), moderate hypoalbuminemia (29.9–25.0 g/L, adjusted OR = 3.44, 95%CI: 1.88–6.28), and severe hypoalbuminemia (ConclusionLow preoperative levels of albumin are strongly associated with POD in geriatric patients with hip fractures, and a significant dose–response relationship exists between them.</p
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