Transparent Computing (TC) is becoming a promising paradigm in network computing era. Although many researchers believe that TC model has a high requirement for the communication bandwidth, there is ...no research on the communication bandwidth boundary or resource allocation, which impedes the development of TC. This paper focuses on studying an efficient transparent computing resource allocation model in an economic view. First, under the quality of experiments (QoE) ensured, the utility function of clients and transparent computing providers (TCPs) is constructed. After that, the demand boundary of communication bandwidth is analyzed under the ideal transparent computing model. Based on the above analyses, a resource allocation scheme based on double-sided combinational auctions (DCA) is proposed so that the resource can be shared by both the service side and the client side with the welfare of the whole society being maximized. Afterward, the results scheduled in different experimental scenarios are given, which verifies the effectiveness of the proposed strategy. Overall, this work provides an effective resource allocation model for optimizing the performance of TC.
Food allergies are a serious food safety and public health issue. Soybean, dairy, aquatic, poultry, and nut products are common allergens inducing allergic reactions and adverse symptoms such as ...atopic dermatitis, allergic eczema, allergic asthma, and allergic rhinitis. Probiotics are assumed as an essential ingredient in maintaining intestinal microorganisms' composition. They have unique physiological roles and therapeutic effects in maintaining the mucosal barrier, immune function, and gastrointestinal tract, inhibiting the invasion of pathogenic bacteria, and preventing diarrhea and food allergies. Multiple pieces of evidence reveal a significant disruptive effect of probiotics on food allergy pathology and progression mechanisms. Thus, this review describes the allergenic proteins as an entry point and briefly describes the application of probiotics in allergenic foods. Then, the role of probiotics in preventing and curing allergic diseases by regulating human immunity through intestinal flora and intestinal barrier, modulating host immune active cells, and improving host amino acid metabolism are described in detail. The anti-allergic role of probiotics in the function and metabolism of the gastrointestinal tract has been comprehensively explored to furnish insights for relieving food allergy symptoms and preventing food allergy.
Since December 2019, a novel coronavirus SARS-CoV-2 has emerged and rapidly spread throughout the world, resulting in a global public health emergency. The lack of vaccine and antivirals has brought ...an urgent need for an animal model. Human angiotensin-converting enzyme II (ACE2) has been identified as a functional receptor for SARS-CoV-2. In this study, we generated a mouse model expressing human ACE2 (hACE2) by using CRISPR/Cas9 knockin technology. In comparison with wild-type C57BL/6 mice, both young and aged hACE2 mice sustained high viral loads in lung, trachea, and brain upon intranasal infection. Although fatalities were not observed, interstitial pneumonia and elevated cytokines were seen in SARS-CoV-2 infected-aged hACE2 mice. Interestingly, intragastric inoculation of SARS-CoV-2 was seen to cause productive infection and lead to pulmonary pathological changes in hACE2 mice. Overall, this animal model described here provides a useful tool for studying SARS-CoV-2 transmission and pathogenesis and evaluating COVID-19 vaccines and therapeutics.
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•Human ACE2 knockin mice were generated by using CRISPR/Cas9 technology•SARS-CoV-2 leads to robust replication in lung, trachea, and brain•SARS-CoV-2 causes interstitial pneumonia and elevated cytokine in aged hACE2 mice•High dose of SARS-CoV-2 can establish infection via intragastric route in hACE2 mice
The COVID-19 pandemic has brought an urgent need for small animal models. Here, Sun et al. established an ACE2 humanized mouse by CRISPR/Cas9 knockin technology. These hACE2 mice are susceptible to SARS-CoV-2 infection upon intranasal inoculation, and the resulting pulmonary infection and pathological changes resemble those observed in COVID-19 patients.
A system that could automatically analyze the facial actions in real time has applications in a wide range of different fields. However, developing such a system is always challenging due to the ...richness, ambiguity, and dynamic nature of facial actions. Although a number of research groups attempt to recognize facial action units (AUs) by improving either the facial feature extraction techniques or the AU classification techniques, these methods often recognize AUs or certain AU combinations individually and statically, ignoring the semantic relationships among AUs and the dynamics of AUs. Hence, these approaches cannot always recognize AUs reliably, robustly, and consistently. In this paper, we propose a novel approach that systematically accounts for the relationships among AUs and their temporal evolutions for AU recognition. Specifically, we use a dynamic Bayesian network (DBN) to model the relationships among different AUs. The DBN provides a coherent and unified hierarchical probabilistic framework to represent probabilistic relationships among various AUs and to account for the temporal changes in facial action development. Within our system, robust computer vision techniques are used to obtain AU measurements. Such AU measurements are then applied as evidence to the DBN for inferring various AUs. The experiments show that the integration of AU relationships and AU dynamics with AU measurements yields significant improvement of AU recognition, especially for spontaneous facial expressions and under more realistic environment including illumination variation, face pose variation, and occlusion.
Two‐dimensional (2D) materials and ultrathin nanosheets are advantageous for elevating the catalysis performance and elucidating the catalysis mechanism of heterogeneous catalysts, but they are ...mostly restricted to inorganic or organic materials based on covalent bonds. We report an electrochemical/chemical exfoliation strategy for synthesizing metal–organic 2D materials based on coordination bonds. A catechol functionalized ligand is used as the redox active pillar to construct a pillared‐layer framework. When the 3D pillared‐layer MOF serves as an electrocatalyst for water oxidation (pH 13), the pillar ligands can be oxidized in situ and removed. The remaining ultrathin (2 nm) nanosheets of the metal–organic layers are an efficient catalyst with overpotentials as low as 211 mV at 10 mA cm−2 and a turnover frequency as high as 30 s−1 at an overpotential of 300 mV.
MOF slicing: A pillared‐layer metal–organic framework (MOF), in which the catechol functionalized pillars can be oxidized and removed in an electrochemical process, gives ultrathin nanosheets (2 nm). These are efficient electrocatalysts for water oxidation at pH 13 with a low overpotential and high turnover frequency (TOF).
Gene silencing holds promise for cancer therapeutics because of its potential to inhibit genes involved in tumor development. However, gene silencing is still restricted by its limited efficacy and ...safety. Nanoscale coordination polymers (CPs) emerge as promising nanocarriers for gene delivery, but their responsiveness and potential therapeutic properties have rarely been explored simultaneously. Here, multifunctional ultrathin 2D nanosheets of Cu(I) 1,2,4‐triazolate CP with a thickness of 4.5 ± 0.8 nm are synthesized using a bottom‐up method. These CP nanosheets can act as both an effective DNAzyme nanocarrier for gene therapy and an intrinsic photosensitizer for hypoxia‐tolerant type I photodynamic therapy (PDT), which is ascribed to the Fenton‐like reaction. Because of the glutathione (GSH)‐responsiveness of the CP nanosheets, DNAzyme‐loaded CP nanosheets exhibit excellent cancer‐cell‐targeting gene silencing of the early growth response factor‐1 (EGR‐1), with messenger RNA inhibited by 84% in MCF‐7 (human breast cancer cells) and only 6% in MCF‐10A (normal human mammary epithelial cells). After tail intravenous injection into MCF‐7‐tumor‐bearing mice, the CP nanosheets loaded with chlorin‐e6‐modified DNAzyme under photoirradiation show a high antitumor efficacy (88.0% tumor regression), demonstrating a promising therapeutic platform with efficient and selective gene silencing and PDT of cancer.
Ultrathin 2D nanosheets of Cu(I) 1,2,4‐triazolate coordination polymer, acting as both stimuli‐responsive nanocarriers of DNAzyme for cancer‐cell‐targeting gene silencing and intrinsic photosensitizers for hypoxia‐tolerant type I photodynamic therapy (PDT), are synthesized by a bottom‐up method. After integrating the DNAzyme with chlorin e6, a type II PDT photosensitizer, the obtained nanoplatform achieves superior therapeutic performance.
The electrocatalytic nitrate‐to‐ammonia reduction reaction route (NARR) is one of the emerging routes toward green ammonia synthesis, and its conversion efficiency is controlled mainly by the ...hydrogenation selectivity. This study proposed a likely NARR route feasible and effective even in a neutral condition. Its high catalytic selectivity and efficiency were achieved by a switch of the sulfate solution to the phosphate buffer solution (PBS), while conditions of NO3− concentration, pH, and applied potential were maintained unchanged. Specifically, the faradaic efficiencies toward NH3 (FENH3
) in Na2SO4 were as low as 9.8, 19.8, and 11.4 % versus remarkably jumping to 82.8, 90.5, and 89.5 % in PBS under −0.75, −1.0, and −1.25 V, respectively. The corresponding faradaic efficiencies toward NO2− (FENO2-
), 77.0, 69.2, and 73.7 % in Na2SO4, significantly dropped to10.8, 7.4, and 4.4 % in PBS, evidencing an unexpected selectivity reversal of the nitrate reduction from NO2− to NH3. This insight was further revealed by the visualization of the pH gradient near the electrode surface during NARR and confirmed by density functional theory calculations; PBS notably facilitated the proton transport and active mitigation over the proton transfer barrier. The use of PBS resulted in a maximal partial current density toward NH3 (JNH3
) and NH3 formation rate (rNH3
) up to 133.5 mA cm−2 and 1.74×10−7 mol s−1 cm−2 in 1.0 m KNO3 at −1.25 V.
Bait and switch: By facilitating the proton transport, the switch from sulfate solution to phosphate solution can cause a selectivity reversal of the nitrate reduction from NO2− to NH3 and a remarkable enhancement in the NH3 formation rate.
In recent years, PCR-based pyrosequencing of 16S rRNA genes has continuously increased our understanding of complex microbial communities in various environments of the Earth. However, there is ...always concern on the potential biases of diversity determination using different 16S rRNA gene primer sets and covered regions. Here, we first report how bacterial 16S rRNA gene pyrotags derived from a series of different primer sets resulted in the biased diversity metrics. In total, 14 types of pyrotags were obtained from two-end pyrosequencing of 7 amplicon pools generated by 7 primer sets paired by 1 of 4 forward primers (V1F, V3F, V5F, and V7F) and 1 of 4 reverse primers (V2R, V4R, V6R, and V9R), respectively. The results revealed that: i) the activated sludge exhibited a large bacterial diversity that represented a broad range of bacterial populations and served as a good sample in this methodology research; ii) diversity metrics highly depended on the selected primer sets and covered regions; iii) paired pyrotags obtained from two-end pyrosequencing of each short amplicon displayed different diversity metrics; iv) relative abundance analysis indicated the sequencing depth affected the determination of rare bacteria but not abundant bacteria; v) the primer set of V1F and V2R significantly underestimated the diversity of activated sludge; and vi) the primer set of V3F and V4R was highly recommended for future studies due to its advantages over other primer sets. All of these findings highlight the significance of this methodology research and offer a valuable reference for peer researchers working on microbial diversity determination.
The electrocatalytic nitrate-to-ammonia reduction reaction (NARR) is a promising route for zero-carbon ammonia synthesis as well as the recycling of nitrate waste, supporting the realization of ...agricultural nutrition supply and irrigation. TiO2 is a great potential NARR electrocatalyst candidate with ideal stability, yet it is hindered by limited selectivity for ammonia. In this regard, Co(ii) atoms with high faradaic efficiency toward NH3 (FENH3) are integrated into TiO2 nanosheets (NSs) (TiO2 NSs), affording a Co(ii)-decorated TiO2 NSs (Co/TiO2 NSs) catalyst. As an alternative to the value of 62.7% obtained using pristine TiO2 NSs, the as-prepared Co/TiO2 NSs catalyst exhibits a remarkable FENH3 increase up to 97.4% in 1.0 M neutral phosphate buffer solution (PBS) with 0.4 M NO3− at −0.72 V (vs. reversible hydrogen electrode, RHE), also outperforming other reported TiO2-based catalysts. And NH3 formation rates (rNH3) of 0.223 and 0.348 mmol cm−2 h−1 are also achieved at −0.72 and −1.12 V (vs. RHE), respectively. Furthermore, NARR also achieves a more favorable onset potential compared with the hydrogen evolution reaction (HER), reducing the energy input and displaying the promising future of NARR in coupling hydrogen production and storage.
Cobalt imidazolate frameworks are classical electrocatalysts for the oxygen evolution reaction (OER) but suffer from the relatively low activity. Here, a non‐3d metal modulation strategy is presented ...for enhancing the OER activity of cobalt imidazolate frameworks. Two isomorphous frameworks Co4(MO4)(eim)6 (M=Mo or W, Heim=2‐ethylimidazole) having Co(eim)3(MO4) units and high water stabilities were designed and synthesized. In different neutral media, the Mo‐modulated framework coated on a glassy carbon electrode shows the best OER performances (1 mA cm−2 at an overpotential of 210 mV in CO2‐saturated 0.5 m KHCO3 electrolyte and 2/10/22 mA cm−2 at overpotential of 388/490/570 mV in phosphate buffer solution) among non‐precious metal catalysts and even outperforms RuO2. Spectroscopic measurements and computational simulations revealed that the non‐3d metals modulate the electronic structure of Co for optimum reactant/product adsorption and tailor the energy of rate‐determining step to a more moderate value.
Non‐3D for 3D: Introducing non‐3d metal oxide units into a cobalt imidazolate framework results in the drastic enhancement of electrocatalytic performance of the oxygen evolution reaction in neutral media.
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