This note is concerned with stability and controller design of networked control systems (NCSs) with packet dropouts. New NCS models are provided considering both single- and multiple-packet ...transmissions. Both sensor-to-controller (S/C) and controller-to-actuator (C/A) packet dropouts are modeled and their history behavior is described by different independent Markov chains. In term of the given models, sufficient conditions for stochastic stability are derived in the form of linear matrix inequalities (LMIs) and corresponding control laws are given. Numerical examples illustrate the effectiveness of the results.
Single‐atom catalysts have emerged as an efficient oxidant activator for eliminating organic pollutants in Fenton‐like systems. However, the complex preparation, single active site, lack of ...understanding of the fundamental mechanism, and harsh pH conditions currently limit their practical applications. In this work, single‐atom iron anchored nitrogen‐rich g‐C3N4 nanotubes (FeCNs) are designed and synthesized by a facile approach, and eco‐friendly peracetic acid (PAA) is selected as the oxidant for Fenton‐like reactions. The constructed heterogenous system achieves an enhanced degradation of various organic contaminants over a wide pH range of 3.0–9.0, exhibiting an ultrahigh and stable catalytic activity, outperforming equivalent quantities of pristine g‐C3N4 by 75 times. The 18O isotope‐labeling technique, probe method, and theoretical calculations demonstrate that the efficient catalytic activity relies on the high‐valency iron‐oxo species coupled with organic radicals generated by PAA. An increase in electron transport from the contaminant to the formed “metastable PAA/FeCN catalyst surface complex” is detected. A double driving mechanism for the tubular g‐C3N4 regulated by a single Fe site and PAA activation is proposed. This work opens an avenue for developing novel catalysts with the coexistence of multiple active units and providing opportunities for significantly improving catalytic efficiency.
Atomically dispersing Fe(III) sites into fine‐tuned nitrogen‐rich graphitic carbon nitride nanotubes are designed for peracetic acid activation and further for Fenton‐like reactions. This work opens a new avenue to develop heterogenous catalytic systems with higher reactivity and better durability using a double engine mechanism.
Inverse photoresponse is discovered from phototransistors based on molybdenum disulfide (MoS2). The devices are capable of detecting photons with energy below the bandgap of MoS2. Under the ...illumination of near‐infrared (NIR) light at 980 and 1550 nm, negative photoresponses with short response time (50 ms) are observed for the first time. Upon visible‐light illumination, the phototransistors exhibit positive photoresponse with ultrahigh responsivity on the order of 104–105 A W−1 owing to the photogating effect and charge trapping mechanism. Besides, the phototransistors can detect a weak visible‐light signal with effective optical power as low as 17 picowatts (pW). A thermally induced photoresponse mechanism, the bolometric effect, is proposed as the cause of the negative photocurrent in the NIR regime. The thermal energy of the NIR radiation is transferred to the MoS2 crystal lattice, inducing lattice heating and resistance increase. This model is experimentally confirmed by low‐temperature electrical measurements. The bolometric coefficient calculated from the measured transport current change with temperature is −33 nA K−1. These findings offer a new approach to develop sub‐bandgap photodetectors and other novel optoelectronic devices based on 2D layered materials.
Broadband phototransistors based on molybdenum disulfide (MoS2) with inverse photoresponse are reported. At 454 nm, the phototransistors exhibit ultrahigh photoresponsivity on the order of 104–105 A W−1. While upon near‐infrared light illumination, negative photoresponses with fast response time (50 ms) are observed for the first time. This work offers a new approach to developing sub‐bandgap photodetectors and other novel optoelectronic devices.
To determine possible modes of virus transmission, we investigated a cluster of coronavirus disease cases associated with a shopping mall in Wenzhou, China. Data indicated that indirect transmission ...of the causative virus occurred, perhaps resulting from virus contamination of common objects, virus aerosolization in a confined space, or spread from asymptomatic infected persons.
A novel colorimetric luminescent probe has been designed by encapsulating excellent Eu3+ into In-MOF, showing high sensitivity and selectivity of chloroform among several small molecules, as well as ...MnO4− among anions.
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A highly fluorescent metal–organic framework (In-MOF, In(OH)bpydc (bpydc=biphenyl-5,5′-dicarboxylate)) imparting additional luminescent Eu3+ ions has been synthesized for sensing organic molecules and anions, especially chloroform and MnO4−, both of them have a significant spectral response. This Eu3+-incorporated hybrid (In-MOF-Eu) has been fully characterized, which reveals large surface area, great pore size, favorable thermal stability, excellent luminescence as well as good fluorescence stability. On the one hand, the dual-emitting MOF hybrid exhibits a distinctly different response to the chloroform, one of which is almost unchanged, while the other intrinsic broad emission has a remarkable enhancement, leading to an obvious change in color; on the other hand, it also shows a high selectivity for detection of MnO4− because of the largest quenching effect on the luminescent emission, which results in a dark emission. This work represents a new approach for the fabrication of highly selective and sensitive probe for detection of chloroform and MnO4−, as it underlines the opportunity of MOFs with prominent optical properties to explore the existing target substance in the environment.
Abstract
No epidemiologic studies have been conducted to assess the association of intake of dietary vitamin K with the risk of pancreatic cancer. We used prospective data from the Prostate, Lung, ...Colorectal, and Ovarian Cancer Screening Trial between 1993 and 2009 to fill this gap. A total of 101,695 subjects were identified. Dietary intakes of phylloquinone (vitamin K1), menaquinones (vitamin K2), and dihydrophylloquinone (dihydrovitamin K1) were assessed using a food frequency questionnaire. Cox regression was applied to calculate hazard ratios and 95% confidence intervals. During a mean follow-up of 8.86 years (900,744.57 person-years), 361 cases of pancreatic cancer were documented. In the fully adjusted model, dietary intakes of phylloquinone (for quartile 4 vs. quartile 1, hazard ratio (HR) = 0.57, 95% confidence interval (CI): 0.39, 0.83; P for trend = 0.002) and dihydrophylloquinone (for quartile 4 vs. quartile 1, HR = 0.59; 95% CI: 0.41, 0.85; P for trend = 0.006), but not menaquinones (for quartile 4 vs. quartile 1, HR = 0.93; 95% CI: 0.65, 1.33; P for trend = 0.816), were found to be inversely associated with the risk of pancreatic cancer in a nonlinear dose–response manner (all P values for nonlinearity < 0.05), and this was not modified by predefined stratification factors and remained in sensitivity analyses. In conclusion, dietary intakes of phylloquinone and dihydrophylloquinone, but not menaquinones, confer a lower risk of pancreatic cancer. Future studies should confirm our findings.
CRISPR/Cas9 is a valuable tool for both basic and applied research that has been widely applied to different plant species. Nonetheless, a systematical assessment of the efficiency of this method is ...not available for the allotetraploid Brassica napus-an important oilseed crop. In this study, we examined the mutation efficiency of the CRISPR/Cas9 method for 12 genes and also determined the pattern, specificity and heritability of these gene modifications in B. napus. The average mutation frequency for a single-gene targeted sgRNA in the T0 generation is 65.3%. For paralogous genes located in conserved regions that were targeted by sgRNAs, we observed mutation frequencies that ranged from 27.6% to 96.6%. Homozygotes were readily found in T0 plants. A total of 48.2% of the gene mutations, including homozygotes, bi-alleles, and heterozygotes were stably inherited as classic Mendelian alleles in the next generation (T1) without any new mutations or reversions. Moreover, no mutation was found in the putative off-target sites among the examined T0 plants. Collectively, our results demonstrate that CRISPR/Cas9 is an efficient tool for creating targeted genome modifications at multiple loci that are stable and inheritable in B. napus. These findings open many doors for biotechnological applications in oilseed crops.
The outbreak of SARS-CoV-2 is posing serious global public health problems. Facing the emergence of this pandemic, we established a portable microfluidic immunoassay system for easy-to-use, ...sensitive, rapid (<15 min), multiple, and on-site detection of IgG/IgM/Antigen of SARS-CoV-2 simultaneously. This integrated method was successfully applied for detecting SARS-CoV-2 IgM and IgG antibodies in clinical human serum as well as SARS-CoV-2 antigen in pharyngeal swabs from 26 patients with COVID-19 infection and 28 uninfected people. The assay demonstrated high sensitivity and specificity, which is promising for the diagnosis and monitoring as well as control of SARS-CoV-2 worldwide.
A near-infrared fluorescent probe (DDAB) for highly selective and sensitive detection of carboxylesterase 2 (CE2) has been designed, synthesized, and systematically studied both in vitro and in vivo. ...Upon addition of CE2, the ester bond of DDAB could be rapidly cleaved and then release a near-infrared (NIR) fluorophore DDAO, which brings a remarkable yellow-to-blue color change and strong NIR fluorescence emission in physiological solutions. The newly developed probe exhibits excellent properties including good specificity, ultrahigh sensitivity and high imaging resolution. Moreover, DDAB has been applied to measure the real activities of CE2 in complex biological samples, as well as to screen CE2 inhibitors by using tissue preparations as the enzymes sources. The probe has also been successfully used to detect endogenous CE2 in living cells and in vivo for the first time, and the results demonstrate that such detection is highly reliable. All these prominent features of DDAB make it holds great promise for further investigation on CE2-associated biological process and for exploring the physiological functions of CE2 in living systems.
A colorimetric near-infrared fluorescent probe (DDAB) for highly selective and sensitive detection of carboxylesterase 2 (CE2) has been designed and well-characterized. This newly developed probe can be used for sensing CE2 in living cells and animals, and holds great promise for exploring the biological functions of CE2 in complex biological systems.
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•A near-infrared fluorescent probe for carboxylesterase 2 (CE2) has been designed.•This probe exhibits good specificity, ultrahigh sensitivity, and fast reaction kinetics.•This newly probe can be used for sensing CE2 in living cells and animals.
Summary Background China is increasingly facing the challenge of control of the growing burden of non-communicable diseases. We assessed the epidemiology of Alzheimer's disease and other forms of ...dementia in China between 1990, and 2010, to improve estimates of the burden of disease, analyse time trends, and inform health policy decisions relevant to China's rapidly ageing population. Methods In our systematic review we searched for reports of Alzheimer's disease or dementia in China, published in Chinese and English between 1990 and 2010. We searched China National Knowledge Infrastructure, Wanfang, and PubMed databases. Two investigators independently assessed case definitions of Alzheimer's disease and dementia: we excluded studies that did not use internationally accepted case definitions. We also excluded reviews and viewpoints, studies with no numerical estimates, and studies not done in mainland China. We used Poisson regression and UN demographic data to estimate the prevalence (in nine age groups), incidence, and standardised mortality ratio of dementia and its subtypes in China in 1990, 2000, and 2010. Findings Our search returned 12 642 reports, of which 89 met the inclusion criteria (75 assessed prevalence, 13 incidence, and nine mortality). In total, the included studies had 340 247 participants, in which 6357 cases of Alzheimer's disease were recorded. 254 367 people were assessed for other forms of dementia, of whom 3543 had vascular dementia, frontotemporal dementia, or Lewy body dementia. In 1990 the prevalence of all forms of dementia was 1·8% (95% CI 0·0–44·4) at 65–69 years, and 42·1% (0·0–88·9) at age 95–99 years. In 2010 prevalence was 2·6% (0·0–28·2) at age 65–69 years and 60·5% (39·7–81·3) at age 95–99 years. The number of people with dementia in China was 3·68 million (95% CI 2·22–5·14) in 1990, 5·62 million (4·42–6·82) in 2000, and 9·19 million (5·92–12·48) in 2010. In the same period, the number of people with Alzheimer's disease was 1·93 million (1·15–2·71) in 1990, 3·71 million (2·84–4·58) people in 2000, and 5·69 million (3·85–7·53) in 2010. The incidence of dementia was 9·87 cases per 1000 person-years, that of Alzheimer's disease was 6·25 cases per 1000 person-years, that of vascular dementia was 2·42 cases per 1000 person-years, and that of other rare forms of dementia was 0·46 cases per 1000 person-years. We retrieved mortality data for 1032 people with dementia and 20 157 healthy controls, who were followed up for 3–7 years. The median standardised mortality ratio was 1·94:1 (IQR 1·74–2·45). Interpretation Our analysis suggests that previous estimates of dementia burden, based on smaller datasets, might have underestimated the burden of dementia in China. The burden of dementia seems to be increasing faster than is generally assumed by the international health community. Rapid and effective government responses are needed to tackle dementia in low-income and middle-income countries. Funding Nossal Institute of Global Health (University of Melbourne, Australia), the National 12th Five-Year Major Projects of China, National Health and Medical Research Council Australia–China Exchange Fellowship, Importation and Development of High-Calibre Talents Project of Beijing Municipal Institutions, and the Bill & Melinda Gates Foundation.
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