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Rapid, sensitive, point-of-care detection of pathogenic bacteria is important for food safety. In this study, we developed a novel quantum dot nanobeads-labelled lateral flow immunoassay strip (QBs-labelled LFIAS) combined with strand displacement loop-mediated isothermal amplification (SD-LAMP) for quantitative Salmonella Typhimurium (ST) detection. Quantum dot nanobeads (QBs) served as fluorescence reporters, providing good detection efficiency. The customizable strand displacement (SD) probe was used in LAMP to improve the specificity of the method and prevent by-product capture. Detection was based on a sandwich immunoassay. A fluorescence strip reader measured the fluorescence intensity (FI) of the test (T) line and control (C) line. The linear detection range of the strip was 102–108 CFU·mL−1. The visual limit of detection was 103 CFU·mL−1, indicating that the system was 10-fold more sensitive than AuNPs-labelled test strips. ST specificity was analyzed in accordance with agarose gel outputs of PCR and SD-LAMP. We detected ST in foods with an acceptable recovery of 85%–110%. The method is rapid, simple, almost equipment-free, and suitable for bacterial detection in foods and for clinical diagnosis.

CRISPR-Cas12a system has been shown promising for nucleic acid diagnostics due to its rapid, portable and accurate features. However, cleavage of the amplicons and primers by the cis- and trans-activity of Cas12a hinders the attempts to integrate the amplification and detection into a single reaction. Through phosphorothioate modification of primers, we realized onepot detection with high sensitivity using plasmids of SARS-CoV-2, HPV16 and HPV18. We also identified the activated Cas12a has a much higher affinity to C nucleotide-rich reporter than others. By applying such reporters, the reaction time required for a lateral-flow readout was significantly reduced. Furthermore, to improve the specificity of the strip-based assay, we created a novel reporter and, when combined with a customized gold-nanopaticle strip, the readout was greatly enhanced owing to the elimination of the nonspecific signal. This established system, termed Targeting DNA by Cas12a-based Eye Sight Testing in an Onepot Reaction (TESTOR), was validated using clinical cervical scrape samples for human papillomaviruses (HPVs) detection. Our system represents a general approach to integrating the nucleic acid amplification and detection into a single reaction in CRISPR-Cas systems, highlighting its potential as a rapid, portable and accurate detection platform of nucleic acids., Graphical abstract Image 1, Highlights • The nucleic acid amplification and Cas12a detection were integrated into a single reaction. • By using the C nucleotide-rich reporter, the reaction time required for a sensitive detection was significantly reduced. • A novel lateral flow system was created, which significantly enhanced the readout.

Low-salinity water flooding, known as an environmentally friendly and efficient oil recovery technology, has attracted the attention of several researchers all over the world. However, its field application is suffering restrictions because of the ambiguous mechanisms of the oil recovery by controlling the salinity. In this study, a water flooding microfluidic experiment was conducted to investigate the pore-scale mechanism of enhanced sweep efficiency by low-salinity water flooding. This experiment used a reservoir-on-a-chip that preserved the real rock properties and morphological features. Crude oil-water-rock contact angle experiments by altering water salinity were conducted to investigate the mechanism of the improvement of sweep efficiency by low-salinity water flooding. The experiment results show that unlike high-salinity water flooding, low-salinity water flooding improves its sweep efficiency from wettability alteration. Specifically, in the microfluidic model, it clearly shows that the pore-scale sweep efficiency is improved by reducing the salinity of injected water. Low-salinity water can invade the pores that cannot be reached by high-salinity water and displace the remaining oil after high-salinity water flooding. In the altering water salinity contact angle experiments, the contact angles decrease from 91.05° (neutral-wet) to 64.41° (water-wet) as the water salinity decreases from 46.58 to 2.31 g/L. The wettability of the rock surface changes from oil or neutral-wet to water-wet and induces the imbibition process, during which the hydrophilic pores absorb the low-salinity water into the smaller pores where the high-salinity water cannot invade. This investigation provides a further in situ and pore-scale evidence of improved sweep efficiency and wettability alteration by low-salinity water flooding and a possible reference to solve the difficulty in upscaling fluid flow behavior from microfluidics to reservoir rocks.

Conotoxins are marine peptide toxins from marine cone snails. The α-conotoxin RegIIA can selectively act on human (h) α3β4 nicotinic acetylcholine receptor (nAChR), and is an important lead for drug development. The high-resolution cryo-electron microscopy structure of the α3β4 nAChR demonstrates several carbohydrates are located near the orthosteric binding sites, which may affect α-conotoxin binding. Oligosaccharide chains can modify the physical and chemical properties of proteins by changing the conformation, hydrophobicity, quality and size of the protein. The purpose of this study is to explore the effect of oligosaccharide chains on the binding modes and activities of RegIIA and its derivatives at hα3β4 nAChRs. Through computational simulations, we designed and synthesized RegIIA mutants at position 14 to explore the importance of residue H14 to the activity of the peptide. Molecular dynamics simulations suggest that the oligosaccharide chains affect the binding of RegIIA at the hα3β4 nAChR through direct interactions with H14 and by affecting the C-loop conformation of the binding sites. Electrophysiology studies on H14 analogues suggest that in addition to forming direct interactions with the carbohydrates, the residue might play an important role in maintaining the conformation of the peptide. Overall, this study further clarifies the structure–activity relationship of α-conotoxin RegIIA at the hα3β4 nAChR and, also provides important experimental and theoretical basis for the development of new peptide drugs.

This work is strategically premeditated to study the potential of a herbal medicinal product as a natural bioactive ingredient to generate nanocellulose-based antibacterial architectures. In situ fibrillation of purified cellulose was done in cinnamon extract (ciE) to obtain microfibrillated cellulose (MFC). To this MFC suspension, carboxylated cellulose nanocrystals (cCNCs) were homogeneously mixed and the viscous gel thus obtained was freeze-dried to obtain lightweight and flexible composite aerogel architectures impregnated with ciE, namely, ciMFC/cCNCs. At an optimal concentration of 0.3 wt % cCNCs (i.e., for ciMFC/cCNCs_0.3), an improvement of around 106% in compressive strength and 175% increment in modulus were achieved as compared to pristine MFC architecture. The efficient loading and interaction of ciE components, specifically cinnamaldehyde, with MFC and cCNCs resulted in developing competent antibacterial surfaces with dense and uniform microstructures. Excellent and long-term antimicrobial activity of the optimized architectures (ciMFC/cCNCs_0.3) was confirmed through various antibacterial assays like the zone inhibition method, bacterial growth observation at OD600, minimum inhibitory concentration (MIC, here 1 mg/mL), minimum bactericidal concentration (MBC, here 3-5 mg/mL), and Live/Dead BacLight viability tests. The changes in the bacterial morphology with a disrupted membrane were further confirmed through various imaging techniques like confocal laser scanning microscopy, FESEM, AFM, and 3D digital microscopy. The dry composite architecture showed the persuasive capability of suppressing the growth of airborne bacteria, which in combination with antibacterial efficiency in the wet state is considered as an imperative aspect for a material to act as the novel biomaterial. Furthermore, these architectures demonstrated excellent antibacterial performance under real "in use" contamination prone conditions. Hence, this work provides avenues for the application of crude natural extracts in developing novel forms of advanced functional biomaterials that can be used for assorted biological/healthcare applications such as wound care and antimicrobial filtering units.

This study is dedicated to investigating the performance of B2O3–Bi2O3–ZnO low-temperature glass-ceramics to immobilize iodine-loaded silver-coated silica-gel (AgIs). Various mass fractions of iodine (15, 20, 25, and 30 wt%) in AgIs were studied. The degree of amorphization and density increased with increasing sintering temperature for all immobilization samples, where, the sample with 20 wt% iodine in AgIs presented optimal immobilization results at 600 °C. The diffraction peak area of AgI was the lowest and the degree of amorphization was the highest (0.562) for the sample with 20 wt% iodine in silver-coated silica gel when it was sintered at 600 °C. SEM-EDS results showed that two approaches contributed to the immobilization of AgIs: the first one is that AgIs participates in the formation of the glass-ceramics phase, which makes iodine uniformly immobilized in the glass mesh; the second one is that the glass-ceramics phase physically encapsulates a small range of aggregated AgI. The results of TGA-DSC analysis showed that the samples had a high water content, which facilitated the lowering of the glass transition temperature of the samples and thus the curing of iodine. Most importantly, when the sintering temperature is below 600 °C, the evaporation of iodine is minimal to negligible. The leaching results showed that the samples were highly resistant to leaching of elemental iodine. This experiment verified the feasibility and efficiency of B2O3–Bi2O3–ZnO ternary glass-ceramics to immobilize iodine-loaded silver-coated silica-gel at low temperatures.

Global lithium-ion battery deployments stand poised to grow substantially in the coming years, but it will be necessary to include sustainability considerations in the design of electrode materials. The current cathode chemistry relies heavily on cobalt, which, due to its scarcity and the environmental abuse and violation of human rights during its mining, must be replaced by abundant and environmentally friendly elements such as redox-active manganese. LiMnO2 is a strong contender for sustainable cathodes but cycles poorly because the Jahn–Teller distorted Mn3+ ions destabilize the lattice framework. Here, we report a LiMnO2 cathode design with interwoven spinel and layered domains. At the interface between these two domains, the Mn dz2 orbitals are oriented perpendicular to each other, giving rise to interfacial orbital ordering, which suppresses the otherwise cooperative Jahn–Teller distortion and Mn dissolution. As a result, the heterostructured cathode delivers enhanced structural and electrochemical cycling stability. This work provides a new strategy for interface engineering, possibly stimulating more research on Mn-rich cathode materials for sustainable lithium-ion batteries. The field of battery chemistry must embrace abundant elements such as Mn for improved sustainability. Here the authors engineer the orientation of Mn 3d orbitals, resulting in excellent performance in LiMnO2 cathodes.

Single- or few-layer transition metal (TM) (oxy)hydroxide and oxide nanosheets are promising two-dimensional (2D) nanomaterials for catalysis and energy storage owing to their plentiful active sites. Facile and scalable synthesis of these 2D ultrathin nanosheets, however, is still a great challenge. Here, we report a liquid phase epitaxy (LPE) method to synthesize single- and few-layer TM (oxy)hydroxide and oxide nanosheets (β-Ni(OH)2, δ-FeOOH, β-CoOOH, and monoclinic LixMnO2) with high-yield and rapid procedure. In the LPE synthesis, the preformed Li2O2 nanosheets with (001) exposed planes function as substrates, enabling the epitaxial growth of TM hydroxides with coherent interface. The final TM (oxy)hydroxides and oxides ultrathin nanosheets can be obtained by in situ oxidation and removal of Li2O2 with simple distilled water washing. To demonstrate their potential applications, the obtained single- and few-layer β-Ni(OH)2 ultrathin nanosheets are coupled with functionalized graphene sheets (FGS), and tested as catalysts for oxygen evolution reaction (OER) and as cathodes for alkaline Ni/Fe battery. Importantly, the single-layer β-Ni(OH)2/FGS composite electrode exhibits excellent catalytic performance for OER and superior charge storage capability for Ni/Fe battery. The present work provides new opportunity for the high-yield synthesis of 2D materials for energy-related applications and beyond.

Nanopore-based sensors have established themselves as a prominent tool for solution-based, single-molecule analysis of the key building blocks of life, including nucleic acids, proteins, glycans and a large pool of biomolecules that have an essential role in life and healthcare. The predominant molecular readout method is based on measuring the temporal fluctuations in the ionic current through the pore. Recent advances in materials science and surface chemistries have not only enabled more robust and sensitive devices but also facilitated alternative detection modalities based on field-effect transistors, quantum tunnelling and optical methods such as fluorescence and plasmonic sensing. In this Review, we discuss recent advances in nanopore fabrication and sensing strategies that endow nanopores not only with sensitivity but also with selectivity and high throughput, and highlight some of the challenges that still need to be addressed. Nanopore sensors enable the solution-based analysis of nucleic acids, proteins and other biomolecules at the single-molecule level. This Review discusses new fabrication and sensing strategies — including field-effect transistors, quantum tunnelling and optical methods — that enhance the sensitivity and selectivity of nanopores.

Conventionally, the evolutions of landscape patterns show different regularities in terms of different spatial scales. Therefore, the changes of arable land use pattern under the influence of human activities in the Loess Plateau of China also follow similar rules. To examine this assumption, we selected Per Capita Arable land Area (PCAA) as an index to indicate arable land use pattern, and Human Activity Intensity (HAI) as an index to indicate the influence of human activities. We also used land use data and demographic data at a 5-year interval from 1990 to 2015 to quantify PCAA and HAI in four different spatial scales across over the Loess Plateau region. These four scales include the whole loess Plateau region, provincial (autonomous region) scale, municipal (autonomous prefecture) scale, and county (city, district) scale. The theoretical model of arable land use pattern and the HAI calculation model were used comprehensively. We performed spatial analysis on the whole PCAA and HAI with the support of GIS geographic information technology, and conducted spatial autocorrelation analysis and Pearson’s correlation analysis. We performed analysis of factor driving on the PCAA and HAI for different land-use types at the county (city, district) scale. We found that the changes in arable land use pattern of the Loess Plateau were dominated by human activities at the whole region and provincial scales from 1990 to 2015. However, at the municipal and county scales, human activities account for 60% of the changes in land use pattern. Two interesting findings were found at the municipal and county scales: one is that with the changing rate of HAI increases, the changing rate of PCAA decreased substantially; the second is that with HAI decreases, PCAA increased significantly. Besides, the changes in arable land use pattern can be explained by the synergy effect of multiple factors of human activities. This study provides insight knowledge in understanding the drives under the change of arable land use pattern in the Loess Plateau and hopefully can provide guidance for the sustainable goal of the local and country scale planning from the management perspective.

Perovskite-type transition metal oxides have emerged as promising electrocatalysts for various electrocatalytic reactions owing to their low cost, compositional tunability and high stability. However, insufficient electrocatalytic activities of pristine perovskite oxides hinder their pathway towards real-world applications. The incorporation of heteroatoms into perovskite oxide structures has been regarded as an efficient way to improve the electrocatalytic performance. This minireview summarizes the recent advances in the heteroatom doping of perovskite oxides as efficient electrocatalysts for the hydrogen evolution reaction (HER), oxygen evolution reaction (OER) and oxygen reduction reaction (ORR). These heteroatom doping strategies are classified based on various types of doping sites. The mechanisms of improved electrocatalytic activities are discussed in detail within different doping sites and various kinds of dopants. Finally, the remaining challenges and perspectives are outlined for future developments of perovskite oxide-based catalysts.

A facile and versatile competitive electrochemical aptasensor for tobramycin (TOB) detection is described using electrochemical-deposited AuNPs coordinated with PEI-functionalized Fe-based metal-organic framework (AuNPs/P-MOF) as signal-amplification platform and a DNA probe labeled with methylene blue (MB) at the 3′-end (MB-Probe) as a signal producer. First, F-Probe (short complementary DNA strands of both the aptamer and the MB-Probe label with a sulfhydryl group at the 5′-end) was immobilized on the AuNPs/P-MOF modified electrode as detection probes, which competed with TOB in binding to the aptamer. TOB-aptamer binding resulted in F-Probe remaining unhybridized on the electrode surface, so that a significant current response was generated by hybridizing with MB-Probe instead. The developed strategy showed favorable repeatability, with a relative standard deviation (RSD) of 4.3% computed over five independent assays, and high stability, with only 6.8% degradation after 15 days of storage. Under optimal conditions, the proposed aptamer strategy exhibited a linear detection range from 100 pM to 500 nM with a limit of detection (LOD) of 56 pM (S/N = 3). The electrochemical aptasensor demonstrated remarkable selectivity, and its feasibility for accurate and quantitative detection of TOB in milk samples was confirmed (RSD

Human norovirus is a common cause of acute gastroenteritis worldwide, and oysters have been found to be the main carriers for its spread. The lack of efficient pre-treatment methods has been a major bottleneck limiting the detection of viruses in oysters. In this study, we established a novel immunomagnetic enrichment method using polyamidoamine (PAMAM) dendrimer/SA-biotin-mediated cascade amplification for reverse transcriptase quantitative real-time polymerase chain reaction (RT-qPCR) detection. We compared the capture efficiency of traditional immunomagnetic enrichment, biotin-amplified immunomagnetic enrichment, and PAMAM dendrimer/SA-biotin-mediated cascade-amplification immunomagnetic enrichment. The optimal capture efficiency of the novel method was 44.26 ± 1.45%, which increased by 183.17% (P < 0.01) and 18.09% (P < 0.05) compared with the first two methods, respectively. Three methods were all applied in detecting norovirus in 44 retail oysters, the detection rate of the PAMAM dendrimer/SA-biotin-mediated method was 25.0%, which was higher than those of traditional IME (15.90%) and SA-biotin-amplified IME (18.80%) by 9.1 and 6.2%, respectively. In conclusion, the novel method can be applied for the rapid detection of norovirus in oysters, which can help reduce the cost and time of detection and improve detection rates.

Phenol is a toxic organic molecule that is widely detected in the natural environment, even in drinking water sources. Biological methods were considered to be a good tool for phenol removal, especially microbial immobilized technology. However, research on the “seed” bacteria along with microbial community analysis in oligotrophic environment such as drinking water system has not been addressed. In this study, Acinetobacter sp. DW-1 with high phenol degradation ability had been isolated from a drinking water biofilter was used as seeded bacteria to treat phenol micro-polluted drinking water source. Meanwhile, the whole genome of strain DW-1 was sequenced using nanopore technology. The genomic analysis suggests that Acinetobacter sp. DW-1 could utilize phenol via the β-ketoadipate pathway, including the catechol and protocatechuate branches. Subsequently, a bio-enhanced polyhedral hollow polypropylene sphere (BEPHPS) filter was constructed to investigate the stability of the seeded bacteria during the water treatment process. The denatured gradient gel electrophoresis (DGGE) profile and the quantification of phenol hydroxylase gene results indicate that when the BEPHPS filter was operated for 56 days, Acinetobacter sp. was still a persistent and competitive bacterium in the treatment group. In addition, 16S rRNA gene amplicon sequencing results indicate that Acinetobacter sp., as well as Pseudomonas sp., Nitrospira sp., Rubrivivax sp. were the predominant bacteria in the treatment group, which were different from that in the CK group. This study provides a better understanding of the mechanisms of phenol degradation by Acinetobacter sp. DW-1 at the gene level, and provides new insights into the stability of seeded bacteria and its effects on microbial ecology during drinking water treatment.

In this study, a mixed-acid-assisted system utilizing a combination of a weak acid (citric acid, CA) and strong acid (H2SO4, SA) under hydrothermal reaction conditions was proposed for simultaneous...

Presently, the demand for single crystal copper micro-components is increasing in various fields because single crystal copper has good electrical conductivity. Micro-milling technology is an effective processing technology for small single crystal copper parts. Surface roughness is a key performance indicator for micro-milling single crystal copper. Establishing a surface roughness prediction model with high precision is useful to guarantee the processing quality by selecting the cutting parameters for micro-milling. Few studies have currently focused on micro-milling single crystal copper. In this study, the orthogonal experiments of micro-milling single crystal copper were conducted, and the influences of the spindle and feed speeds and axial depth of cut on the surface roughness of micro-milled single crystal copper with different orientations were analyzed by range analyses. The spindle rotation speed was the major affecting factor. The surface roughness of single crystal copper in different crystal orientations was predicted by using the SVM method. Experimental results showed that the average relative error of the surface roughness of , , and crystal orientation single crystal copper was 2.7 %, 3.3 %, and 2.2 %, respectively, and that the maximum relative errors were 7.0 %. 10.1 %, and 3.1 %, respectively. The uncertainty analysis was conducted by using the Monte Carlo method to verify the reliability of the built surface roughness model.

Two efficient transition-metal-free highly regioselective pathways for constructing sulfonylated imidazoles via three-component reactions of amidines, ynals, and sodium sulfonates have been developed. The generations of different sulfonylated imidazoles were simply controlled by additives. In addition, this method features environmental friendliness, good functional group tolerance, and high atom economy, which makes it practical.

A facile and efficient strategy for the extraction of lignin and lignocellulosic biomass processing is crucial for sustainability of current biorefineries. In this work, lignin was extracted from e...

PF-06651600 was developed as an irreversible inhibitor of JAK3 with selectivity over the other three JAK isoforms. A high level of selectivity toward JAK3 is achieved by the covalent interaction of PF-06651600 with a unique cysteine residue (Cys-909) in the catalytic domain of JAK3, which is replaced by a serine residue in the other JAK isoforms. Importantly, 10 other kinases in the kinome have a cysteine at the equivalent position of Cys-909 in JAK3. Five of those kinases belong to the TEC kinase family including BTK, BMX, ITK, RLK, and TEC and are also inhibited by PF-06651600. Preclinical data demonstrate that inhibition of the cytolytic function of CD8+ T cells and NK cells by PF-06651600 is driven by the inhibition of TEC kinases. On the basis of the underlying pathophysiology of inflammatory diseases such as rheumatoid arthritis, inflammatory bowel disease, alopecia areata, and vitiligo, the dual activity of PF-06651600 toward JAK3 and the TEC kinase family may provide a beneficial inhibitory profile for therapeutic intervention.

This study reports a new approach for the preparation of molybdenum (Mo) with controllable morphology by reducing molybdenum trioxide (MoO3) with ammonia (NH3). It is found that the morphology and ...

Pure hydrogen does not occur in large quantities in nature, and it is usually locked up in energy-rich organic compound. One of the challenges to sustain the usage of hydrogen energy is to produce sufficient energy-rich organic compound from the organic compound reservoir of hydrogen and carbon, which requires understanding the fluid flow behavior through such reservoir. The horizontal fractures can be created during the hydraulic fracturing process in shallow energy-rich organic compound reservoirs due to the geo-mechanical effect. However, it lacks of a comprehensive analytical model to describe the transient flow behavior through the horizontal fractures. In this paper, an analytical model for horizontal fractures in shallow organic compound reservoirs considering the effects of wellbore storage and skin factor with constant pressure, closed and infinite boundary conditions, are presented to investigate pressure transient behavior and flow characteristics. The analytical solution is derived in Laplace domain, which may require numerical inverse transform to obtain the solution real space. To obtain the explicit form in real space, the approximate solutions for early time, middle time and late time are also presented to investigate the characteristics of type curves. Type curves are established for the transient pressure analysis to recognize the flow characteristics through horizontal fractures. Flow for horizontal fractures can be divided into five stages according to characteristics of dimensionless pseudo pressure derivative curve. The effects of parameters on pressure behavior are discussed in detail, which include wellbore storage coefficient, dimensionless formation thickness, dimensionless vertical location, and skin factor. The results indicate that horizontal fractures are more applicable in thin instead of thick reservoirs.

Hydrogen energy can be generated by steam methane reforming method, and methane production from coal seams is important to ensure the abundance of hydrogen energy generation. The gaseous compound of hydrogen and carbon production performance analysis is important and pressure transient analysis can be used to analyze the flow characteristics in the development of gaseous compound of hydrogen and carbon in coalbed reservoir. The computational models on vertical wells, vertically fractured wells and horizontal wells have been studied intensively in coalbed reservoir to predict gaseous compound of hydrogen and carbon production behavior. For a thin coalbed methane reservoir, it will be more effective to develop through forming horizontal fractures near the wellbore. However, such model has not been established. To analyze gaseous compound of hydrogen and carbon production performance for horizontal fractures in coalbed methane reservoirs, this paper presents a 3D point-sink model and the corresponding solution is obtained through using Laplace transform and Fourier transform methods. The point-source integral method is used to obtain the general solutions of gaseous compound of hydrogen and carbon flow through horizontal fractures. The pressure transient solution have been compared with numerical simulation to validate its accuracy. Type curves are established to analyze the flow characteristics of gaseous compound of hydrogen and carbon, which can be divided into four regions, i.e., linear flow region, transition flow region, inter-porosity flow region, and radial flow region. The sensitive analysis of the key model parameters on type curves has been conducted.

During a large laboratory-scale purification of FK228 from the fermentation broth of Burkholderia thailandensis MSMB43, a small amount of thiosulfinated FK228 (TS-FK228) was unexpectedly purified only after the broth was mixed with silica gel. Evidence supports the postulations that TS-FK228 was derived from FK228 through spontaneous chemical reaction with silica gel, and TS-FK228 existed as two isomers 1 and 2. TS-FK228 demonstrated similar inhibitory activity and profile against human class I histone deacetylases but exhibited a much higher antiproliferative activity against representative human cancer cell lines when compared to FK228.

Chlorantraniliprobe (Chlo), a potent insecticide, demolishes intracellular Ca2+ homeostasis of insects by inducing uncontrolled Ca2+ release through ryanodine receptors (RyRs). Chlo is lethal to insects but has low toxicity to mammals. In this study, we investigated the effects of Chlo on RyR1 from mammalian skeletal muscle. Ca2+ release assay indicated that Chlo at high concentrations promoted Ca2+ release from sarcoplasmic reticulum through RyR1 channels. Single channel recording of purified RyR1 showed that Chlo activated RyR1 channel, increased channel open probability Po, reduced channel mean close time Tc, but did not change the channel mean open time To, suggesting that Chlo destabilized the closed RyR1 channel, rendered the channel easy to open. The dissociation constant Kd values of Chlo for RyR1 were of micromolar level, approximately 100-fold larger than that for insect RyR. The Kd values were smaller for open states than for closed/blocked states of the RyR1 channel. The maximal binding capacity Bmax did not change in the presence of either channel activators or inhibitors/blockers. Our results demonstrate that the insecticide Chlo is a weak activator of mammalian RyR1. It can interact with mammalian RyR1 and activate RyR1 channel but with much lower affinity compared with insect RyR; Chlo has a binding site distinct from all known RyR channel modulators and represents a novel type of RyR channel modulator. Our data provide biochemical and pharmacological insights into its high specificity to insect RyR and high selectivity of poisoning to insects over mammals.

A new kind of biobased material named lignin-containing polyhydroxyurethane (LPHU) is prepared from bis(6-membered cyclic carbonate) (BCC), dimer fatty diamine, and lignin for the first time. The preparation strategy is isocyanate-free, solvent-free, and catalyst-free, representing a green and environmentally friendly method to access polyurethane (PU)/lignin composites. The resultant LPHUs possess dual networks: a dynamic covalent network and a hydrogen bonding network, exhibiting superior mechanical strength, high thermal stability, excellent reprocessability/recyclability, and smart properties such as shape memory and self-healing. Potential application investigations indicate that the resultant LPHUs can be not only used for smart packaging label fabrication for heat-sensitive commodities but also further combined with natural cellulose paper to prepare paper-based electromagnetic shielding materials with high mechanical performance.

Vibrio parahaemolyticus is an important foodborne pathogen and its biofilm formation ability facilitates its colonization and persistence in foods by protecting it from stresses including environmental variation and antibiotic exposure. Several important proteins are involved in biofilm formation; however, the identity and function of many remain unknown. In this study, we discovered a hypothetical protein, VP0610 that negatively regulates biofilm formation in Vibrio parahaemolyticus, and we found that the loss of vp0610 typically results in pleiotropic phenotypes that contribute toward promoting biofilm formation, including significantly increased insoluble exopolysaccharide production and swimming motility, decreased soluble exopolysaccharide production, and decreased bis-(3′-5′)-cyclic dimeric guanosine monophosphate production. Pull-down assays revealed that VP0610 can interact with 180 proteins, some of which (Hfq, VP0710, VP0793, and CyaA) participate in biofilm formation. Moreover, deleting vp0610 enhanced the expression of genes responsible for biofilm component (flaE), the sugar phosphotransferase system (PTS) EIIA component (vp0710 and vp0793), and a high-density regulator of quorum sensing (opaR), while reducing the expression of the bis-(3′-5′)-cyclic dimeric guanosine monophosphate degradation protein (CdgC), resulting in faster biofilm formation. Taken together, our results indicate that vp0610 is an integral member of the key biofilm regulatory network of V. parahaemolyticus that functions as a repressor of biofilm formation.

The CRISPR/Cas12a system has displayed remarkable potential in the development of new methods for nucleic acid detection owing to the trans-cleavage activity of Cas12a. Despite the tremendous development in recent years, existing CRISPR/Cas12a-based methods have several limitations such as the time-consuming process, which takes up to 2 h, and the risk of aerosol contamination during DNA amplicon transfer. Herein, we propose a CRISPR/Cas12a-based fluorescence detection platform named “Cas12aFDet” for rapid nucleic acid detection that overcomes these limitations. By integrating PCR or recombinase-aided amplification (RAA) methods with Cas12a-mediated cleavage in a sealed reaction tube, Cas12aFDet-based detection of amplified products could be accomplished within 15 min, while avoiding amplicon contamination. The detection limits of PCR-based Cas12aFDet and RAA-based Cas12aFDet were determined to be 3.37 × 101 cfu/mL and 1.35 × 102 cfu/mL of Listeria monocytogenes serotype 4c in pure culture, respectively. Most importantly, RAA-based Cas12aFDet exhibited 0.64 aM sensitivity for DNA detection, and showed high specificity for detection of other serotypes of Listeria and non-Listeria strains. Furthermore, the feasibility of the RAA-based Cas12aFDet method was evaluated in spiked and natural samples, enabling the quantitative detection of 1.35 × 108–1.35 × 103 cfu/g fresh grass carp of the target L. monocytogenes serotype 4c, and the results obtained for 22 natural aquatic samples were highly consistent with those of the culture-based serotyping method. The established Cas12aFDet platform is expected to provide a new paradigm for the sensitive and specific detection of pathogens in food safety and clinical diagnosis.

Esophageal carcinoma stem cells (ECSCs) are responsible for the initiation and therapy-resistance of esophageal cancer. Nutrient sensor O-GlcNAc transferase (OGT) promoted the growth and metastasis of cancer cells. However, the contributions of OGT to the tumorigenesis of ECSCs remain largely uncover. In the present study, as compared to matched non-stem cancer cells, the expression of OGT was higher in ALDH+ ECSCs. Knock down of OGT by lentivirus system reduced the self-renewal capacities and tumorigenicity of ALDH+ ECSCs. In addition, OGT in exosome derived from ALDH+ ECSCs was taken up by neighboring CD8+ T cells and increased the expression of PD-1 in CD8+ T cells. Down-regulation of OGT increased the apoptosis of ALDH+ ECSCs induced by CD8+ T cells, which could be blocked by overexpression of PD-1 in CD8+ T cells. Together, OGT in exosome from ECSCs protects ECSCs from CD8+ T cells through up-regulation of PD-1.

Pathogenic Escherichia coli poses a serious threat to global public health and is especially dangerous with the increase of antibiotic resistance. β-Glucuronidase (GUS) and some other glycosidases can serve as useful biomarkers or indicators for the detection of E. coli. The probes made up of a glycosyl residue (recognition group), a label or reporter group, and a linkage that is generally a direct glycosidic bond, are powerful analytical tools. Upon hydrolysis of the glycosidic linkages by the corresponding glycosidases, these probes irreversibly release detectable labels or reporter molecules. A variety of such glycosidase probes have been developed and applied for the detection of E. coli or the development of various corresponding detection methods. This paper provides an overview of recent advances in this field, covering the development and applications of chromogenic, fluorogenic, luminogenic, and electrochemical glycosidase substrates. The challenges and opportunities in the probe development for detection of E. coli are also discussed.

CRISPR/Cas12a system has been shown promising for nucleic acid diagnostics due to its rapid, portable and accurate features. In combination with isothermal amplification technology, single-copy sensitivity can be achieved. However, cleavage of the amplicons and primers by the cis- and trans-activity of Cas12a hinders the attempts to integrate the amplification and detection steps into a single reaction. Through phosphorothioate modification of primer and design of crRNA that allow for the cutting site locating at the modified site of the primer, we realized onepot detection of SARS-CoV-2 with single-copy sensitivity. We also identified the activated Cas12a has a much higher affinity to C nucleotide-rich reporter than others. By applying such reporters, we significantly reduced the reaction time required for the lateral-flow readout. Furthermore, to improve the specificity of the strip-based assay, we created a novel reporter and, when combined with a customized strip, the unspecific signal could be completely eliminated. This established system termed Targeting DNA by Cas12a-based Eye Sight Testing in Onepot Reaction (TESTOR) was validated using clinical cervical samples for human papillomaviruses (HPVs) detection. Our system represents a general approach to integrating the nucleic acid amplification and detection into a onepot reaction in CRISPR-Cas systems, highlighting its potential as a rapid, portable and accurate detection platform of nucleic acids.

Syntheses of carbonate chemistry spatial patterns are important for predicting ocean acidification impacts, but are lacking in coastal oceans. Here, we show that along the North American Atlantic and Gulf coasts the meridional distributions of dissolved inorganic carbon (DIC) and carbonate mineral saturation state (Ω) are controlled by partial equilibrium with the atmosphere resulting in relatively low DIC and high Ω in warm southern waters and the opposite in cold northern waters. However, pH and the partial pressure of CO2 (pCO2) do not exhibit a simple spatial pattern and are controlled by local physical and net biological processes which impede equilibrium with the atmosphere. Along the Pacific coast, upwelling brings subsurface waters with low Ω and pH to the surface where net biological production works to raise their values. Different temperature sensitivities of carbonate properties and different timescales of influencing processes lead to contrasting property distributions within and among margins., Anthropogenic CO2 is acidifying the ocean, but knowledge of the carbonate properties underlying these dynamics in coastal oceans is lacking. Here, the authors reveal spatial distribution patterns and variability in carbonate chemistry along North America’s coasts.

Cranberries contain various constituents relevant to human health. Our previous study demonstrated the chemopreventive effects of whole cranberry against colon cancer in mice. In order to determine the role of different cranberry secondary metabolites in inhibiting colon cancer, cranberry ethyl acetate extract (EAE) and polyphenol extract (PPE) were obtained. The free-radical scavenging activities and chemical composition of the cranberry extracts were determined. EAE consisted of triterpenes and sterols and a trace amount of proanthocyanidins. PPE mainly contained polyphenol with a trace amount of triterpenes. The chemopreventive effects of orally administered EAE and PPE on colitis-associated colon carcinogenesis were determined in mice. Dietary EAE and PPE significantly suppressed tumor metrics without noticeable adverse effects. Gene expression levels of key proinflammatory cytokines were also attenuated by EAE and PPE in the mouse colon. In conclusion, the novel cranberry extracts may offer an efficacious and safe means to prevent colonic tumorigenesis in humans.

MicroRNA (miR)‑539 has inhibitory effects on certain types of cancer, but its role in pancreatic cancer (PCa) remains unclear. The present study investigated the effects of miR‑539 on PCa, and aimed to determine possible therapeutic targets for the treatment of PCa. The expression of miR‑539 in PCa tissues, paired normal adjacent tissues and PCa cell lines (CAPAN‑2, BxPC3, CFPAC1, SW1990 and PANC1), and human non‑cancerous pancreatic cells (hTRET‑HPNE) was determined and compared. The effects of upregulation and downregulation of miR‑539 on proliferation, apoptosis, cell cycle, invasion, migration and epithelial‑mesenchymal transition (EMT) of PCa cells were investigated. Additionally, the target gene of miR‑539 was predicted and its effects on PCa cells were further investigated. The results revealed low expression of miR‑539 in PCa tissues and cell lines. Additionally, increasing miR‑539 expression inhibited the proliferation, migration, invasion and EMT of PCa cells and induced apoptosis by blocking G1 phase of the cell cycle, while reducing miR‑539 expression had the opposite results. Furthermore, specificity protein 1 (SP1) was found to be the target gene of miR‑539. SP1 promoted the proliferation, migration, invasion and EMT transformation of PCa cells, but these effects were reversed by high expression of miR‑539. Additionally, miR‑539 suppressed the proliferation, metastasis, invasion and EMT transformation of PCa cells through targeting SP1. Therefore, miR‑539 overexpression may contribute toward development of novel therapeutic strategies for PCa in the future.

Sulfur deposition commonly occurs during the development of a high-sulfur gas reservoirs. Due to the high gas flow velocity near the wellbore, some of the deposited sulfur particles re-enter the pores and continue to migrate driven by the high-speed gas flow. The current mathematical model for sulfur deposition ignores the viscosity between particles, rising flow caused by turbulence, and the corresponding research on the release ratio of particles. In order to solve the above problems, firstly, the viscous force and rising force caused by turbulence disturbance are introduced, and the critical release velocity of sulfur particles is derived. Then, a release model of sulfur particles that consider the critical release velocity and release ratio is proposed by combining the probability theory with the hydrodynamics theory. Notably, based on the experimental data, the deposition ratio of sulfur particles and the damage coefficient in the sulfur damage model are determined. Finally, a comprehensive particle migration model considering the deposition and release of sulfur particles is established. The model is then applied to the actual gas wells with visible sulfur deposition that target the Da-wan gas reservoir, and the results show that the model correctly reflects flow transport during the process of sulfur deposition in porous media. In addition, through the numerical simulation experiments, it was found that considering the release of sulfur particles reduces the saturation of sulfur particles within a specific range around the well and improve the reservoir permeability in this range. From the perspective of gas production rate, the release of sulfur particles has a limited effect on the gas production rate, which is mainly due to the sulfur particle release being limited, having only a 5 m range near the wellbore area, and thus the amount of gas flow from the unaffected area is basically unchanged.

Both natural processes and human activities affect seawater calcium carbonate saturation state (&Omega, arag), while the mechanisms are still far from being clearly understood. This study analysed the seawater surface &Omega, arag during summer and winter in Jiaozhou Bay (JZB), China, based on two cruises observations performed in January and June 2017. The ranges of &Omega, arag values were 1.55~2.92 in summer and 1.62~2.15 in winter. Regression analyses were conducted to identify the drivers of the change of &Omega, arag distribution, and then the relative contributions of temperature, mixing processes and biological processes to the spatial differences in &Omega, arag were evaluated by introducing the difference between total alkalinity (TA) and dissolved inorganic carbon (DIC) as a proxy for &Omega, arag. The results showed that biological processes were the main factor affecting the spatial differences in &Omega, arag, with relative contributions of 70% in summer and 50% in winter. The contributions of temperature (25% in summer and 20% in winter) and the mixing processes (5% in summer and 30% in winter) were lower. The increasing urbanization in offshore areas can further worsen acidification, therefore environmental protection in both offshore and onshore is needed.

Campylobacter jejuni is a major foodborne pathogen worldwide. As it forms biofilms, it can become a persistent contaminant in the food and pharmaceutical industries. In this study, it was demonstrated that C. jejuni could make more biofilm in aerobic conditions than in microaerobic conditions, and only 13.9% C. jejuni entered coccus (a VBNC state) under microaerobic conditions; however, the rate increased to 95.5% under aerobic conditions. C. jejuni could form more biofilm in mixed culture with Escherichia coli or Pseudomonas aeruginosa than in pure culture. Scanning electron microscope results showed that C. jejuni retained its normal spiral shape under aerobic conditions for 48 h by forming crosslinks with the aerobic and facultative anaerobic bacteria. Additionally, culture medium containing 0.5 mg/ml ZnO nanoparticles inhibited biofilm formation. Our results provide information on a new approach to controlling contamination via C. jejuni.

Although much is known about the machinery that executes fundamental processes of gene expression in cells, much also remains to be learned about how that machinery works. A recent paper by O’Reilly et al. reports a major step forward in the direct visualization of central dogma processes at submolecular resolution inside bacterial cells frozen in a native state. The essential methodologies involved are cross-linking mass spectrometry (CLMS) and cryo-electron tomography (cryo-ET). In-cell CLMS provides in vivo protein interaction maps. Cryo-ET allows visualization of macromolecular complexes in their native environment. These methods have been integrated by O’Reilly et al. to describe a dynamic assembly in situ between a transcribing RNA polymerase (RNAP) and a translating ribosome – a complex known as the expressome – in the model bacterium Mycoplasma pneumoniae(1). With the application of improved data processing and classification capabilities, this approach has allowed unprecedented insights into the architecture of this molecular assembly line, confirming the existence of a physical link between RNAP and the ribosome and identifying the transcription factor NusA as the linking molecule, as well as making it possible to see the structural effects of drugs that inhibit either transcription or translation. The work provides a glimpse into the future of integrative structural cell biology and can serve as a roadmap for the study of other molecular machineries in their native context.

The soils in karst regions, with carbonate rocks as the background material, are characterized by two main factors, drought and high calcium levels. Handeliodendron bodinieri (Levl.) Rehd is an endemic plant species in this area of China. However, few studies have been carried out on the adaptation mechanism of H. bodinieri to drought and high calcium soil. To reveal the physiological responses of H. bodinieri to exogenous calcium under drought stress, 10% PEG-6000 was used to simulate drought stress, and the effects of exogenous calcium at different concentrations on the physiology of H. bodinieri seedlings under drought stress were studied. The results showed that drought stress significantly reduced the relative water content and water potential of H. bodinieri seedlings. Malondialdehyde (MDA) content, O2&minus, and H2O2 production rates significantly increased under drought stress. The addition of exogenous calcium significantly reduced MDA content and O2&minus, and H2O2 production rates. Moreover, peroxidase (POD), superoxide dismutase (SOD), catalase (CAT), ascorbic acid peroxidase (APX) and glutathione peroxidase (GPX) activities increased significantly under drought stress. At the same time, the accumulation of osmotic regulators such as soluble sugar, betaine and free proline also increased significantly. The addition of exogenous calcium further increased the activity of antioxidant enzymes and the accumulation of osmotic regulatory substances. Consequently, the oxidative stress and osmotic stress induced by drought decreased. Finally, exogenous calcium enhanced the photosynthetic rate (Pn), stomatal conductance (Gs) and transpiration rate (Tr) of H. bodinieri under drought stress and significantly improved water use efficiency (WUE). This study confirmed that the application of exogenous calcium can enhance the water condition, photosynthetic capacity, osmotic regulation and antioxidant capacity of H. bodinieri under drought stress. Of the treatments, the 10 mmol&middot, L&minus, 1 CaCl2 treatment is more likely to improve survival of H. bodinieri under drought tolerance. This study provides an important reference for describing the adaptation mechanism and appropriate conservation of H. bodinieri under drought and high calcium conditions.

A model wetland with Salix was established to investigate the effects of CuO nanoparticles (NPs; the equivalent amount of Cu at 0, 100 and 500 mg/kg) on plant, soil enzyme activity and microbial community. Ionic Cu (100, 500 mg/kg) and bulk-sized CuO particles (BPs, 500 mg/kg) were included as controls. The results suggested the CuO NPs at 500 mg/kg and ionic Cu treatments inhibited the plant growth, while CuO NPs at 100 mg/kg and CuO BPs at 500 mg/kg played a facilitating role. CuO NPs significantly decreased the activities of peroxidase and polyphenol oxidase, while ionic Cu treatments increased peroxidase activity, BPs and ionic Cu (500 mg/kg) increased the polyphenol oxidase activity. Bacterial community richness and diversity were reduced in all Cu treatments; however, CuO NPs and BPs at 500 mg/kg significantly increased the richness and diversity of fungal community.Soil microbial community was significantly altered by Cu types and dose. In comparison with ionic Cu and CuO BPs, CuO NPs uniquely enriched the microbial community and the fungal families.Overall, it demonstrate that both particle size and dose regulate the impact of CuO on wetland ecology, which deepens our understanding on the ecological risks of CuO NPs in freshwater forested wetland.