Transmissibility is a key parameter to quantify the effectiveness of a vibration isolation system. Under harmonic excitation, the force transmissibility of a linear vibration isolation system is ...defined as the ratio between the amplitude of the force transmitted to the host structure and the excitation force amplitude, and the displacement transmissibility is the ratio between the displacement amplitude of the payload and that of the base. For a nonlinear vibration isolation system, the force or the displacement responses usually have more frequency components than the excitation. For a harmonic excitation, the response may be periodic, quasi-periodic or chaotic. Therefore, the amplitude ratio cannot well define the transmissibility. The root-mean-square ratio of the response to the excitation is suggested to define the transmissibility. The significance of the modified transmissibility is highlighted in a nonlinear two-stage vibration isolation system consisting of two linear spring connected linear vibration isolators with two additional horizontal linear springs. Harmonic balance method (HBM) is applied to determine the responses with the fundamental and third harmonic. Numerical simulations reveal that chaos may occur in the responses. In both cases, the modified transmissibility works while the original definition cannot be applied to chaotic response.
•Two definitions of nonlinear transmissibility are compared.•Two definitions are slightly different for both force and displacement transmission.•Force and displacement transmissibility with modified definition are more agreement.•Transmissibility for aperiodic response is evaluated by the modified definition.
A new operator splitting method is proposed for American options under time-fractional Black–Scholes models. The fractional linear complementarity problem is split into two easy sub-problems, with ...the leading coefficients separated from the convolution sum and matched through a general correction step. The method is implementation friendly in the sense that one can easily modify a fractional European solver to obtain the proposed method, since the correction step is decoupled and is trivial to solve. The method is validated through numerical experiments and demonstrated to be superior to the traditional approach. The paper also provides numerical studies including the effect of fractional orders and the comparison of fractional models.
Early diagnosis is crucial to slowing the progression of Alzheimer's disease (AD), so it is urgent to find an effective diagnostic method for AD. This study intended to investigate whether the ...transfer learning approach of deep Q‐network (DQN) could effectively distinguish AD patients using local metrics of resting‐state functional magnetic resonance imaging (rs‐fMRI) as features. This study included 1310 subjects from the Consortium for Reliability and Reproducibility (CoRR) and 50 subjects from the Alzheimer's Disease Neuroimaging Initiative (ADNI) GO/2. The amplitude of low‐frequency fluctuation (ALFF), fractional ALFF (fALFF) and percent amplitude of fluctuation (PerAF) were extracted as features using the Power 264 atlas. Based on gender bias in AD, we searched for transferable similar parts between the CoRR feature matrix and the ADNI feature matrix, resulting in the CoRR similar feature matrix served as the source domain and the ADNI similar feature matrix served as the target domain. A DQN classifier was pre‐trained in the source domain and transferred to the target domain. Finally, the transferred DQN classifier was used to classify AD and healthy controls (HC). A permutation test was performed. The DQN transfer learning achieved a classification accuracy of 86.66% (p < 0.01), recall of 83.33% and precision of 83.33%. The findings suggested that the transfer learning approach using DQN could be an effective way to distinguish AD from HC. It also revealed the potential value of local brain activity in AD clinical diagnosis.
The deep Q‐network using transfer learning methods could effectively classify small‐sample Alzheimer's disease (AD) data. The local brain neural activity of AD patients can serve as effective biomarkers to differentiate between AD and healthy controls (HC).
Since the occurrence of coronavirus disease 2019 (COVID-19) in Wuhan, China in December 2019, COVID-19 has been quickly spreading out to other provinces and countries. Considering that traditional ...Chinese medicine (TCM) played an important role during outbreak of SARS and H1N1, finding potential alternative approaches for COVID-19 treatment is necessary before vaccines are developed. According to previous studies, Maxing Shigan decoction (MXSGD) present a prominent antivirus effect and is often used to treat pulmonary diseases. Furthermore, we collected 115 open prescriptions for COVID-19 therapy from the National Health Commission, State Administration of TCM and other organizations, MXSGD was identified as the key formula. However, the underlying molecular mechanism of MXSGD against COVID-19 is still unknown.
The present study aimed to evaluate the therapeutic mechanism of MXSGD against COVID-19 by network pharmacology and in vitro experiment verification, and screen the potential components which could bind to key targets of COVID-19 via molecular docking method.
Multiple open-source databases related to TCM or compounds were employed to screen active ingredients and potential targets of MXSGD. Network pharmacology analysis methods were used to initially predict the antivirus and anti-inflammatory effects of MXSGD against COVID-19. IL-6 induced rat lung epithelial type Ⅱ cells (RLE-6TN) damage was established to explore the anti-inflammatory damage activity of MXSGD. After MXSGD intervention, the expression level of related proteins and their phosphorylation in the IL-6 mediated JAK-STAT signaling pathway were detected by Western blot. Molecular docking technique was used to further identify the potential substances which could bind to three key targets (ACE2, Mpro and RdRp) of COVID-19.
In this study, 105 active ingredients and 1025 candidate targets were selected for MXSGD, 83 overlapping targets related to MXSGD and COVID-19 were identified, and the protein-protein interaction (PPI) network of MXSGD against COVID-19 was constructed. According to the results of biological enrichment analysis, 63 significant KEGG pathways were enriched, and most of them were related to signal transduction, immune system and virus infection. Furthermore, according the relationship between signal pathways, we confirmed MXSGD could effectively inhibit IL-6 mediated JAK-STAT signal pathway related protein expression level, decreased the protein expression levels of p-JAK2, p-STAT3, Bax and Caspase 3, and increased the protein expression level of Bcl-2, thereby inhibiting RLE-6TN cells damage. In addition, according to the LibDock scores screening results, the components with strong potential affinity (Top 10) with ACE2, Mpro and RdRp are mainly from glycyrrhiza uralensis (Chinese name: Gancao) and semen armeniacae amarum (Chinese name: Kuxingren). Among them, amygdalin was selected as the optimal candidate component bind to all three key targets, and euchrenone, glycyrrhizin, and glycyrol also exhibited superior affinity interactions with ACE2, Mpro and RdRp, respectively.
This work explained the positive characteristics of multi-component, multi-target, and multi-approach intervention with MXSGD in combating COVID-19, and preliminary revealed the antiviral and anti-inflammatory pharmacodynamic substances and mechanism of MXSGD, which might provide insights into the vital role of TCM in the prevention and treatment of COVID-19.
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2D transitional metal dichalcogenides (TMDs) have attracted great interest for their advantageous application in room‐temperature broadband photodetectors. Developing effective strategies to optimize ...the photo‐carrier dynamical process of monolayer TMDs is still urgently necessary to extend wavelength range and reduce dark current due to the theoretical limitation of their intrinsic band structure. Herein, an interesting approach is reported to realize broadband photodetection from 532 to 1550 nm with low dark current for the first time by using composition‐triggered growth of coherent atomic structures of enriched nanoscale mix‐phase (2H/1T') monolayer MoTe2(1−x)S2x alloys. The morphology and phase evolution at the nanoscale of monolayer MoTe2(1−x)S2x alloys are elucidated as affected by tiny formation energy (ΔE) by the chemical composition of S/Te atoms triggered. As‐grown enriched nanoscale mix‐phase (2H/1T') of monolayer MoTe2(1−x)S2x alloys devices exhibit typical n‐type conductivity properties. More interestingly, the devices show an extended photo‐response range from 532 to 1550 nm with reduced dark current to 10−10 A at 100 mV bias voltage. This work demonstrates that coherent atomic structure of enriched nanoscale mix‐phase (2H/1T′) monolayer TMDs alloys can be an alternative approach to obviously extend photo‐response wavelength range without increasing dark current for room temperature broadband photodetection.
Controlled growth of enriched nanoscale mix‐phase (2H/1T') MoTe2(1−x)S2x alloy with coherent atomic structures by composition‐triggered. Coherent phase interfaces of monolayer MoTe2(1−x)S2x alloys exhibit a wide photo‐response range from 532 to 1550 nm with dark current ≈10−10 A at 100 mV bias voltage. The responsivity and response time are 101 mA W−1 and 258 ms under 1550 nm illumination, respectively.
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•Urchin-like hollow NiCo2S4 was synthesized via a template-free method.•The interconnected urchin exterior accelerated electron transport.•Urchin-like hollow NiCo2S4 displayed a high ...specific capacitance of 1398F g−1 at 1 A g−1.
Hollow structures draw much attention for high energy density supercapacitors due to their large hollow cavities, high specific surface area, and low interfacial contact resistance. However, constructing hierarchical hollow structures remains a challenge. Herein, we reported a facile template-free method for a novel urchin-like hollow nickel cobalt sulfide (NiCo2S4). The hollow interior and urchin exterior remarkably improved the specific capacitance and accommodated structural collapse caused by electrochemical reactions. Owing to these features, the urchin-like hollow NiCo2S4 spheres exhibited an impressive capacitance of 1398F g−1 at 1 A g−1 and maintained 1110F g−1 with a large current density of 10 A g−1. The hybrid supercapacitor fabricated by NiCo2S4 and active carbon possesses an energy density of 39.3 Wh kg−1 at a power density of 749.6 W kg−1 and an outstanding cycling stability of 74.4% retention after 5000 cycles. Our work presents a facile method of constructing a hollow structure of binary sulfide materials and also makes progress on highly efficient supercapacitors.
•Functions of crustacean zooplankton in the southern Yellow Sea were recorded.•Composition of the zooplankton functional groups differed among four seasons.•Omnivore–carnivore group dominant in ...spring, and herbivore dominant in other seasons.•Seasonal variations of water masses significantly affected zooplankton functions.
Functional trait and functional diversity indices reflect the variations of community structure and indicate their responses to environmental stress. In this study, based on four functional traits, including body length, feeding type, trophic group, and reproductive mode, the functional diversity and functional groups of crustacean zooplankton from the southern Yellow Sea (SYS) were explored over four seasons of 2019. A total of 53 species were identified and categorized into six functional groups. Copepods with ambush-feeding and omnivore–carnivore diet (Group Ⅱ) were dominant in spring (55.6%), while omnivore–herbivore copepods (Group Ⅰ) were the most abundant group in the other three seasons (>54.7%). The comparable distributions of functional diversity indices in different seasons were most likely due to hydrological variations. The Changjiang River Diluted Water promoted the coexistence of multiple traits carried by different functional groups (high functional richness (FRic) and functional dispersion (FDis)), but the stability of ecosystem function in this water mass was vulnerable to the loss of individual species (low functional evenness (FEve)) in summer. In winter, as a result of the Yellow Sea Warm Current, warm-water taxa increased FRic and FEve, suggesting that the community could buffer environmental fluctuations more effectively. Moreover, distribution of FRic values indicates the possible range and influence intensity of the Yellow Sea Cold Water Mass.
The Hippo signaling effector, TEAD1 plays an essential role in cardiovascular development. However, a role for TEAD1 in postmitotic cardiomyocytes (CMs) remains incompletely understood. Herein we ...reported that TEAD1 is required for postmitotic CM survival. We found that adult mice with ubiquitous or CM-specific loss of Tead1 present with a rapid lethality due to an acute-onset dilated cardiomyopathy. Surprisingly, deletion of Tead1 activated the necroptotic pathway and induced massive cardiomyocyte necroptosis, but not apoptosis. In contrast to apoptosis, necroptosis is a pro-inflammatory form of cell death and consistent with this, dramatically higher levels of markers of activated macrophages and pro-inflammatory cytokines were observed in the hearts of Tead1 knockout mice. Blocking necroptosis by administration of necrostatin-1 rescued Tead1 deletion-induced heart failure. Mechanistically, genome-wide transcriptome and ChIP-seq analysis revealed that in adult hearts, Tead1 directly activates a large set of nuclear DNA-encoded mitochondrial genes required for assembly of the electron transfer complex and the production of ATP. Loss of Tead1 expression in adult CMs increased mitochondrial reactive oxygen species, disrupted the structure of mitochondria, reduced complex I-IV driven oxygen consumption and ATP levels, resulting in the activation of necroptosis. This study identifies an unexpected paradigm in which TEAD1 is essential for postmitotic CM survival by maintaining the expression of nuclear DNA-encoded mitochondrial genes required for ATP synthesis.
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•The gut microbiome profile of a rat model of MNNG-induced gastric carcinogenesis was analyzed.•Changes in gut microbiota composition were detected by 16S rRNA gene ...sequencing.•Bacterial species richness increased and diversity decreased during gastric carcinogenesis progression.•The most significant changes were occurred at the precancerous lesion of GC stage.•Gut microbiome changes in the rat gastric carcinogenesis model were similar to those in human.
Although many studies have examined changes in gut microbiota composition in gastric carcinogenesis to clarify the mechanism of action of anticancer drugs, it is unclear whether animal models of gastric carcinogenesis adequately reflect the disease in humans.
To address this issue, the present study investigated changes in the gut microbiome profile of a rat model of gastric carcinogenesis established using a combination of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), sodium salicylate, irregular fasting, and ranitidine. The rats were divided into control (Normal), chronic non-atrophic gastritis (CNAG), chronic atrophic gastritis (CAG), precancerous lesion of gastric cancer (PLGC), and gastric cancer (GC) groups according to histopathological features. Gut microbiome in gastric carcinogenesis profiling was performed by 16S rRNA gene sequencing of rat feces samples.
We found that gut bacterial species richness increased whereas species diversity decreased during gastric carcinogenesis, with the most significant changes detected in the PLGC group. Gut microbiota community composition differed across groups, with the greatest similarities observed between CNAG and CAG groups and between PLGC and GC groups. There were significant differences in taxonomic representation at the phylum level: the PLGC group had the highest ratio of Firmicutes/Bacteroidetes whereas the GC group had the highest abundance of Proteobacteria and Actinobacteria.
These results indicate that changes in the gut microbiome in a rat model of MNNG-induced gastric carcinogenesis are similar to those observed in humans, thus providing a useful tool for evaluating the efficacy and mechanism of action of novel monotherapies or drug combinations for the treatment of gastric carcinogenesis.
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