Search

Rapid and effective differentiation and quantification of a small molecule drug, such as fentanyl, in bodily fluids are major challenges for diagnosis and personal medication. However, the current toxicology methods used to measure drug concentration and metabolites require laboratory-based testing, which is not an efficient or cost-effective way to treat patients in a timely manner. Here, we show an assay for monitoring fentanyl levels by combining the intermolecular interaction-enabled small molecule recognition (iMSR) with differential impedance analysis of conjugated polymers. The differential interactions with the designed anchor interface were transduced through the perturbance of the electric status of the flexible conducting polymer. This assay showed excellent fentanyl selectivity against common interferences, as well as in variable body fluids through either testing strips or skin patches. Directly using the patient blood, the sensor provided 1%-5% of the average deviation compared to the "gold" standard method LC-MS results in the medically relevant fentanyl range of 20-90 nM. The superior sensing properties, in conjunction with mechanical flexibility and compatibility, enabled point-of-care detection and provided a promising avenue for applications beyond the scope of biomarker detection.

A metal-free, atom and redox-economical approach for the assembly of C–C bonds has been developed using oligofluorene-based hypercrosslinked polymers as the recoverable and reusable photocatalysts under visible-light irradiation.

α‑Amino acids such as glycine derivatives have been commonly utilized as reagents for decarboxylative functionalization. In contrast to previous reports that require transition-metals and organic dyes to promote this process, we herein report a catalyst-free approach for the decarboxylative amination of glycine derivatives with azo compounds under visible-light irradiation. A range of important aminals are achieved under mild reaction conditions with high efficiency.

We report the design and synthesis of urushiol derivatives as biomass-based catalysts for photocatalytic, transition-metal-free access to 1,2-amino alcohols.

A highly reducing conjugated porous polymer enables pinacol C–C coupling with superior performance in a metal-free and recyclable fashion under visible light.

Carrageenan is a common additive, but mounting studies have reported that it may cause or aggravate inflammation in the intestines. The safety of carrageenan remains controversial and its inflammatory mechanisms are unclear. In this review, the pathogenesis of colitis by carrageenans was discussed. We analyzed the pathogenesis of inflammatory bowel disease, followed that line of thought, the existing evidence of carrageenans causing colitis in cellular and animal models was summarized to draw its colitis pathogenesis. Two pathways were described including: 1) carrageenan changed the composition of intestinal microbiota, especially Akkermansia muciniphila, which destroyed the mucosal barrier and triggered the inflammatory immune response; and 2) carrageenan directly contacted with receptors on epithelial cells and activated the NF-κB inflammatory pathway. This review aim to provide guidance for exploring the treatment of colitis caused by carrageenan, and safe processing and utilization of carrageenan in food industry, which is worthy of study in the future.

The increasing frequency of floods is causing an increasing impact on urban communities. To identify the key influencing factors of functional loss in Chinese urban communities under floods, this paper explored the influencing factors and factor combinations through a social network analysis approach using the 265 cases of urban communities in China affected by floods collected from 2017–2021 as research data. The key influencing factors and factor combinations were identified comprehensively using multiple indicator analyses such as core-periphery structure, node centrality, and factor pairing. The analysis results showed that “road disruption”, “housing inundation”, and “power interruption” are the three most critical factors affecting the functional loss of urban communities in China under floods, followed by “residents trapped”, “enterprises flooded”, and “silt accumulation”. In addition, “road disruption–housing inundation”, “housing inundation–residents trapped”, and “road disruption–residents trapped” are the most common combinations of influencing factors.

Background Diabetes mellitus is an endocrine and metabolic system disease characterized by hyperglycaemia and insulin resistance, and has become a prevalent disease around the world. Fucoidan has a good hypoglycaemic effect and ideal development potential in the treatment of diabetes based on their specific chemical structures, such as monosaccharide compositions and glycosidic linkages. Scope and approach However, the relationship between structure-function and activity has not yet been clarified. This article discusses the structural characteristics of fucoidan, including its backbone structure, glycosidic bond positions, monosaccharide types, sulphate content, and molecular weight. The potential therapeutic effect of fucoidan on hyperglycaemia and diabetic complications caused by diabetes is also reviewed. Key findings and conclusions Fucoidan reduces blood sugar levels through α-amylase and α- d -glucosidase inhibition, a Sirt-1-dependent manner, and the cAMP, PI3K/AKT, and JNK/AKT signalling pathways. The outstanding biological function of fucoidan is due its unique chemical structure. Among them, fucoidan of low molecular weight and high degree of sulfation displays greater anti-diabetic activity, and persulphated fucoidan derivatives showed significantly enhanced hypoglycaemic activities. Moreover, only (1,3) and (1,4) alternatively linked fucoidan showed a stronger inhibitory effect on α- d -glucosidase.

This work constructed a new-type bisphenol A (BPA) electrochemical sensor on the basis of self-assembled multi-layer strategy of Ce-Zn-metal organic framework/multiwall carbon nanotube (Ce-Zn-MOF/MWCNT)–modified glassy carbon electrodes (GCE). The novel bimetallic Ce-Zn-MOF are synthesized by 1,3,5-benzenetricarboxylic acid (H3BTC) as the ligand via a hydrothermal approach. Bimetallic Ce-Zn-MOF with multiple catalytic sites and ultra-high specific surface area introduces traditional electrode modification materials, which improves the conductivity and catalytic ability of MWCNTs. Field emission scanning electron microscopy, transmission electron microscope and Powder X-ray diffraction were performed to analyze the Ce-Zn-MOF/MWCNTs. The electrochemical property was researched utilize differential pulse voltammetry (DPV), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). In the optimum conditions, the proposed sensor exhibited a wider dynamic linear range of BPA determination in 0.1 to 100 μmol·L−1 with a detection limit of 7.2 nmol·L−1 (S/N = 3). This measurement of BPA was successfully used for drinking water with desirable recovery from 96.5 to 103.4%.

Here we describe a visible-light-induced, catalyst and additive-free approach for the [5 + 2] cycloadditions of vinylcyclopropanes (VCPs) with thioparabanates. This operationally simple strategy provides straightforward and atom-economic access to functionalized sulfur-containing seven-membered heterocycles, which bear two contiguous fully substituted stereogenic centers under mild reaction conditions.

A Gram-stain-negative, rod-shaped, motile, mesophilic, and aerobic bacterial strain, designated SM2-42

Perovskite solar cells (PSCs) have attracted more and more attention in the scientific community due to their high performance and simple fabrication process. In the past few years, emerging technologies have made manufacturing large‐scale PSC modules possible. However, stability and fabrication issues still limit the modularization and commercialization of PSCs. Carbon materials have been widely used in PSCs to overcome these challenges due to their excellent optical, electrical, and mechanical properties. In addition, the hydrophobic properties of certain carbon materials are highly effective at protecting the perovskite film from moisture and improving the stability of PSCs. All these superior properties have made carbon one of the most promising materials to fabricate future high‐performance PSC modules with long service lifetimes. In this review, recent developments of carbon‐based materials in different layers of single‐junction PSCs will first be discussed, with an emphasis on functionalities related to PSCs’ stability and modularization. Then, current improvements and future discussions in the manufacturing of monolithic PSC modules will be reviewed in detail.

Due to the demand of public health maintenance, disinfectant generator technologies that utilize green processes are becoming attractive. It has been confirmed that single-walled carbon nanotubes (SWCNTs) could generate reactive oxygen species (ROS) in water when illuminated with solar irradiation. However, low efficiency due to the competitive reactions between ROS and water in aqueous media and unclear kinetics hinder their potential practical applications. To overcome these limitations, here, the SWCNTs were studied in a nonaqueous ionic liquid (IL) to form a suspension system to generate superoxide (O2 -) under UV light. The as-obtained O2 - from SWCNTs was qualitatively confirmed by electron paramagnetic resonance and UV-visible spectroscopy. The sustainability of the new SWCNTs/IL system was confirmed by UV-visible spectroscopy and Fourier-transform infrared spectroscopy. The IL proved to be an ideal media that could extend the duration of O2 - from a few microseconds (commonly generated in the water) to at least 65 hours in the IL. The kinetics of photodynamic effect was investigated by electrochemical characterizations. A new method was established to in-situ monitor the O2 - level in the IL system. The O2 - level in the IL was quantitatively determined by combining cyclic voltammetry and chronoamperometry techniques. The SWCNTs/IL system generated 4.11 mM of O2 - in a mini-scale generator, which was excessive to germicidal levels for ROS. The sustainable, long duration and high-yield of the generator exhibited an excellent potential as a generator as well as an in-situ monitor for O2 -. This work could pave the way for O2 - generation using SWCNTs and promote its applications in air and water disinfection for public health, as well as O2 - sensitive chemical sensors for monitoring environmental quality.

In this paper, a novel bimetallic Ce-Ni metal-organic frameworks (Ce-Ni-MOF) are synthesized by hydrothermal reaction, using 1,3,5-benzenetricarboxylic acid as a ligand. In particular, the bimetallic Ce-Ni-MOF with the largest specific surface area and catalytic sites was synthesized when the molar ratio of Ce3+ to Ni2+ was 3:7. Bimetallic Ce-Ni-MOF is added to the traditional conductive material of multiwall carbon nanotubes (MWCNTs) to play their synergistic effect, improve the conductivity, specific surface area, and catalytic site of the MWCNTs. A novel bisphenol A (BPA) sensor was successfully prepared by a self-assembled multilayer strategy of Ce-Ni-MOF/MWCNTs modified glassy carbon electrodes (GCE). Field emission scanning electron microscopy, powder X-ray diffraction, and transmission electron microscope were carried out to characterize the Ce-Ni-MOF/MWCNTs. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used as a sensitive analytical method for the determination of BPA, and a wider linear dynamic range of BPA determination in 0.1 μmol·L−1 to 100 μmol·L−1 with a detection limit of 7.8 nmol·L−1 (S/N = 3). The proposed method was applied to measure the content of BPA in different brands of drinking water with satisfying recovery from 97.4 to 102.4%.

The importance of phytoplankton cell death is being increasingly recognized, however, there are still no published reports on this in Xiamen Bay. In this study, the proportion of dead phytoplankton cells associated with environmental factors was assessed at a station in Xiamen Bay from December 2012 to December 2013, using a cell digestion assay, which is an effective method to analyze dead/ living cells in complex natural phytoplankton communities. The percentages of dead cells (% DC) in the total phytoplankton in summer (16%±6%) were lower than those in winter (27%±16%). Six groups of phytoplankton (G1–G6) were categorized by flow cytometry. These phytoplankton communities with diverse seasonal variations in % DC had different responses to environmental constraints. The main factors affecting mortality were temperature and salinity, while nutrient concentration showed little influence on phytoplankton death. Additionally, our results provide evidence that chlorophyll a concentrations had an inverse relationship with total phytoplankton % DC and viable cell abundance was more meaningful than total cells to explain variations in environmental parameters (such as Chl a). Moreover, the lowest mean % DC in total phytoplankton was 16%±6% at our sample site, which is in a subtropical area with high water temperatures, full solar radiation, and rich nutrients. This indicates that phytoplankton cell death is a process that cannot be ignored. In summary, phytoplankton cell death is important in understanding the dynamics of phytoplankton communities and the functioning of subtropical ecosystems.

The research on biomarker detection has increased dramatically in recent years and many strategies has emerged. However, current methods for identifying specific biomarkers and small molecules for point of care (POC) diagnosis outcomes suffer shortcomings of limited specificity and complex procedure in the measurement and the lack of real-time analysis to establish a causal relationship between an individual's profile and impact on health. The goals of our research are 1) to provide researchers with a new tool to better assess the impacts of biomarkers and small molecules for the cancer diagnosis and treatment and 2) to provide individuals with an inexpensive benchtop device for rapid reporting of exposure data for personalized alerts and managed care services. To achieve these goals, we are exploring several key technologies and approaches that will enable implementation of a novel autonomous sensorarray microsystem for acute multi-analyte assessment, such as sulfatases, antibody/antigen and micro-RNA/RNA, with the sensitive real-time monitoring. Electrochemistry signals were classified and quantified during the bio-interactions on the designed electrode interface, exhibiting the excellent sensitivity and specificity for targeting biomarkers without adding signal media and label. This project would provide medical researchers and physicians with a much needed and currently non-existent tool for personal treatment assessment and decision, leading to more relevant disease regulation, intervention for individuals diagnosis, and ultimately improvement of overall public health.

Malignant glioma is the most prevalent form of malignant brain tumor. Although radiotherapy is widely used in glioma treatment, the radioresistance of glioma cells limits the success of the glioma treatment. The lack of effective targets and signaling pathways to reverse glioma radioresistance is the critical obstacle in successful treatment. In this study, we demonstrate that mitochondrial ATP-sensitive potassium channels (mtK(ATP) channels) are overexpressed in glioma cells and are closely related to the malignancy grade and the overall survival of the patients. Importantly, we showed that mtK(ATP) channels could control glioma radioresistance by regulating reactive oxygen species (ROS)-induced ERK activation. The inhibition of mtK(ATP) channels suppresses glioma radioresistance by inhibiting ERK activation both in vitro and in vivo. These findings reveal the important roles of the mitochondria and mtK(ATP) channels as key regulators in the radioresistance of glioma cells, and suggest that mtK(ATP) channel blockers and MAPK/ERK kinase (MEK) inhibitors are potential targets for drug development of glioma treatments.

Orthogonal frequency-division multiplexing (OFDM) is the ubiquitous contemporary technology adopted for digital audio/video broadcasting, as well as wireless local and metropolitan area networks. Since the wireless multimedia services often have different quality-of- service requirements and their performance is sensitive to the channel conditions, the conventional fixed OFDM modulation scheme might not be a satisfactory solution nowadays. In this paper, we introduce a novel pilot-free adaptive modulation scheme, which is bandwidth efficient and allows variable data rates, for the future robust OFDM systems. We design a number of modulation modes in a combination of different constellation sizes and different polynomial cancellation coding (PCC) methods to combat the crucial intercarrier interference (ICI) problem. Instead of estimating the channel quality based on the overhead pilot symbols, we propose to directly estimate the signal-to-noise ratio (SNR) free of using any pilot. Moreover, our scheme offers more modulation modes than some other existing adaptive modulation methods, which are simply based on different constellation sizes. According to the Monte Carlo simulations, the empirical results show that our adaptive modulation scheme, in most channel conditions (SNR ges 13 dB), not only can satisfy the predetermined bit-error-rate (BER) requirement (BER les 10-4) but also can dynamically enhance the throughputs in the rather clean environments with high SNR values.

The intercarrier interference (ICI) due to the Doppler frequency shift, sampling clock offset, time-varying multipath fading and local oscillator frequency offset becomes the major difficulty for the data transmission via the wireless orthogonal frequency division multiplexing (OFDM) systems. The existing ICI mitigation schemes involve the frequency-domain channel estimation/equalization or the additional coding and therefore require the pilot symbols which reduce the throughput. The frequency-domain channel estimation/equalization relies on the huge matrix inversion with high computational complexity especially for the OFDM technologies possessing many subcarriers such as digital video broadcasting (DVB) systems and wireless metropolitan-area networks (WMAN). In our previous work, we proposed a semi-blind ICI equalization scheme using the joint multiple matrix diagonalization (JMMD) algorithm and empirically showed that the proposed method significantly improved the symbol error rates for QPSK- and 16QAM-OFDM systems. In this paper, we discuss the sufficient condition for the theoretical ICI equalizability and also propose an alternative semi-blind ICI equalization method based on the joint approximate diagonalization of eigen-matrices (JADE) algorithm, which is much more computationally efficient than our previous method.