Sensitive and deformable chemical sensors manufactured by a low-cost process are promising as they are disposable, can be applied on curved, complex structures, and provide environmental information ...to users. Although many nanomaterial-based flexible sensors have been suggested to meet these demands, their limited chemical sensitivity and mechanical flexibility pose challenges. Here, a highly deformable chemical sensor is reported with improved sensitivity that integrates multiwalled carbon nanotubes (CNTs) and nanolayered transition metal dichalcogenides (TMDCs) on cellulose paper. Liquid dispersions of CNTs and TMDCs are absorbed and dried on porous cellulose for sensor fabrication, which is simple, scalable, rapid, and inexpensive. The cellulose substrate enables reversible three-dimensional folding and unfolding, bending down to 0.25 mm, and twisting up to 1800° (∼628.4 rad m–1) without degradation, and the CNTs maintain a percolation network and simultaneously provide gas reactivity. Functionalization of CNTs with TMDCs (WS2 or MoS2) greatly improves the sensing response upon exposure to NO2 molecules by more than 150%, and the sensor can also selectively detect NO2 over diverse reducing vapors. The measured NO2 sensitivity is 4.57% ppm–1, which is much higher than that of previous paper-based sensors. Our sensor can stably and sensitively detect the gas even under severe deformation such as heavy folding and crumpling. Hybrid integration of CNTs and TMDCs on cellulose paper may also be used to detect other harmful gases and can be applicable in low-cost portable devices that require reliable deformability.
Amino acids and immune function Li, Peng; Yin, Yu-Long; Li, Defa ...
British journal of nutrition,
08/2007, Volume:
98, Issue:
2
Journal Article
Peer reviewed
Open access
A deficiency of dietary protein or amino acids has long been known to impair immune function and increase the susceptibility of animals and humans to infectious disease. However, only in the past 15 ...years have the underlying cellular and molecular mechanisms begun to unfold. Protein malnutrition reduces concentrations of most amino acids in plasma. Findings from recent studies indicate an important role for amino acids in immune responses by regulating: (1) the activation of T lymphocytes, B lymphocytes, natural killer cells and macrophages; (2) cellular redox state, gene expression and lymphocyte proliferation; and (3) the production of antibodies, cytokines and other cytotoxic substances. Increasing evidence shows that dietary supplementation of specific amino acids to animals and humans with malnutrition and infectious disease enhances the immune status, thereby reducing morbidity and mortality. Arginine, glutamine and cysteine precursors are the best prototypes. Because of a negative impact of imbalance and antagonism among amino acids on nutrient intake and utilisation, care should be exercised in developing effective strategies of enteral or parenteral provision for maximum health benefits. Such measures should be based on knowledge about the biochemistry and physiology of amino acids, their roles in immune responses, nutritional and pathological states of individuals and expected treatment outcomes. New knowledge about the metabolism of amino acids in leucocytes is critical for the development of effective means to prevent and treat immunodeficient diseases. These nutrients hold great promise in improving health and preventing infectious diseases in animals and humans.
Abstract
Although prime editing is a promising genome editing method, the efficiency of prime editor 2 (PE2) is often insufficient. Here we generate a more efficient variant of PE2, named hyPE2, by ...adding the Rad51 DNA-binding domain. When tested at endogenous sites, hyPE2 shows a median of 1.5- or 1.4- fold (range, 0.99- to 2.6-fold) higher efficiencies than PE2; furthermore, at sites where PE2-induced prime editing is very inefficient (efficiency < 1%), hyPE2 enables prime editing with efficiencies ranging from 1.1% to 2.9% at up to 34% of target sequences, potentially facilitating prime editing applications.
A complete switch in the Cp*Ir(III)-catalyzed paths between C–H olefination and hydroarylation was found to be crucially dependent on the type of directing groups. This dichotomy in product ...distribution was correlated to the efficiency in attaining syn-coplanarity of olefin-inserted 7-membered iridacycles. Theoretical studies support our hypothesis that the degree of flexibility of this key intermediate modulates the β-H elimination, which ultimately affords the observed chemoselectivity.
Although cryopreservation has been developed and optimized over the past decades, it causes various stresses, including cold shock, osmotic stress, and ice crystal formation, thereby reducing ...fertility. During cryopreservation, addition of cryoprotective agent (CPA) is crucial for protecting spermatozoa from freezing damage. However, the intrinsic toxicity and osmotic stress induced by CPA cause damage to spermatozoa. To identify the effects of CPA addition during cryopreservation, we assessed the motility (%), motion kinematics, capacitation status, and viability of epididymal spermatozoa using computer-assisted sperm analysis and Hoechst 33258/chlortetracycline fluorescence staining. Moreover, the effects of CPA addition were also demonstrated at the proteome level using two-dimensional electrophoresis. Our results demonstrated that CPA addition significantly reduced sperm motility (%), curvilinear velocity, viability (%), and non-capacitated spermatozoa, whereas straightness and acrosome-reacted spermatozoa increased significantly (p < 0.05). Ten proteins were differentially expressed (two decreased and eight increased) (>3 fold, p < 0.05) after CPA, whereas NADH dehydrogenase flavoprotein 2, f-actin-capping protein subunit beta, superoxide dismutase 2, and outer dense fiber protein 2 were associated with several important signaling pathways (p < 0.05). The present study provides a mechanistic basis for specific cryostresses and potential markers of CPA-induced stress. Therefore, these might provide information about the development of safe biomaterials for cryopreservation and basic ground for sperm cryopreservation.
•We proposed a self-supervised framework capturing Alzheimer's disease heterogeneity.•The framework merged feature extraction, classification, and clustering for identifying AD heterogeneity.•The ...latent space identified progression and subtypes as core dimensions.•Longitudinal analysis revealed dynamic progression paths like medial temporal and parietotemporal.
Alzheimer's disease (AD) is heterogeneous, but existing methods for capturing this heterogeneity through dimensionality reduction and unsupervised clustering have limitations when it comes to extracting intricate atrophy patterns. In this study, we propose a deep learning based self-supervised framework that characterizes complex atrophy features using latent space representation. It integrates feature engineering, classification, and clustering to synergistically disentangle heterogeneity in Alzheimer's disease. Through this representation learning, we trained a clustered latent space with distinct atrophy patterns and clinical characteristics in AD, and replicated the findings in prodromal Alzheimer's disease. Moreover, we discovered that these clusters are not solely attributed to subtypes but also reflect disease progression in the latent space, representing the core dimensions of heterogeneity, namely progression and subtypes. Furthermore, longitudinal latent space analysis revealed two distinct disease progression pathways: medial temporal and parietotemporal pathways. The proposed approach enables effective latent representations that can be integrated with individual-level cognitive profiles, thereby facilitating a comprehensive understanding of AD heterogeneity.
A cathode material of an electrically conducting carbon‐LiMnPO4 nanocomposite is synthesized by ultrasonic spray pyrolysis followed by ball milling. The effect of the carbon content on the ...physicochemical and electrochemical properties of this material is extensively studied. A LiMnPO4 electrode with 30 wt% acetylene black (AB) carbon exhibits an excellent rate capability and good cycle life in cell tests at 55 and 25 °C. This electrode delivers a discharge capacity of 158 mAh g−1 at 1/20 C, 126 mAh g−1 at 1 C, and 107 mAh g−1 at 2 C rate, which are the highest capacities reported so far for this type of electrode. Transmission electron microscopy and Mn dissolution results confirm that the carbon particles surrounding the LiMnPO4 protect the electrode from HF attack, and thus lead to a reduction of the Mn dissolution that usually occurs with this electrode. The improved electrochemical properties of the C‐LiMnPO4 electrode are also verified by electrochemical impedance spectroscopy.
The addition of acetylene black (AB) carbon to a nanostructured C‐LiMnPO4 cathode material results in an extraordinary electrode material for a lithium cell with very high reversible capacity and an excellent cycle life. The composite can easily be made by ultrasonic spray pyrolysis followed by ball milling. Microscopic studies confirm that the carbon particles protect the cathode materials from dissolution.
This study aimed to identify the factor structure of the Korean version of the Short Grit Scale (Grit-S) and examine its cross-sectional and longitudinal measurement invariance (MI). Data from the ...Korean Children and Youth Panel Survey 2018 were analyzed, which included two cohorts, comprising 2,327 and 2,325 fourth-year elementary and first-year middle school students, respectively. It was found that the two-factor model fit the data well for the elementary and middle school samples. The results of the cross-sectional MI tests across genders indicated that the full threshold and loading invariance were also supported for the elementary school sample, and the partial threshold and loading invariance were supported for the middle school sample. The analyses of the longitudinal MI revealed that the partial threshold and loading invariance were supported for both samples. The reliability analysis revealed satisfactory McDonald's Omega values for both samples at each time point and moderate stability coefficients over time. Based on these findings, it was concluded that the Korean version of the Grit-S demonstrated satisfactory psychometric properties and exhibited MI across gender and time in Korean adolescents.
Understanding the mechanisms behind human mobility patterns is crucial to improve our ability to optimize and predict traffic flows. Two representative mobility models, i.e., radiation and gravity ...models, have been extensively compared to each other against various empirical data sets, while their fundamental relation is far from being fully understood. In order to study such a relation, we first model the heterogeneous population landscape by generating a fractal geometry of sites and then by assigning to each site a population independently drawn from a power-law distribution. Then the radiation model on this population landscape, which we call the radiation-on-landscape (RoL) model, is compared to the gravity model to derive the distance exponent in the gravity model in terms of the properties of the population landscape, which is confirmed by the numerical simulations. Consequently, we provide a possible explanation for the origin of the distance exponent in terms of the properties of the heterogeneous population landscape, enabling us to better understand mobility patterns constrained by the travel distance.
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