Potential for efficient microbial remediation of Cr (VI) in wastewater using Deinococcus wulumuqiensis R12

AIMS

This study aimed to investigate the potential of Deinococcus wulumuqiensis R12 (D. wulumuqiensis R12) as a bioadsorbent for Cr (VI) removal from aqueous solutions.

METHODS AND RESULTS

Effects of various factors including initial concentration of Cr (Ⅵ), pH, adsorbent dosage and time were explored. The maximal Cr removal efficiency was achieved by adding D. wulumuqiensis R12 to the solution at pH 7.0 for 24 h, with an initial Cr concentration of 7 mg L-1. Characterization of bacterial cells showed that Cr was adsorbed to the surface of D. wulumuqiensis R12 by combining with functional groups, such as carboxyl and amino groups on the surface. Furthermore, D. wulumuqiensis R12 was able to keep its bioactivity in the presence of Cr and tolerate Cr concentrations as high as 60 mg L-1.

CONCLUSIONS

D. wulumuqiensis R12 demonstrates a comparatively high adsorption capacity for Cr (VI). Under the optimized conditions, the removal ratio reached 96.4% with 7 mg L-1 Cr (VI), and the maximal biosorption capacity was 2.65 mg g-1. More importantly, it was found that D. wulumuqiensis R12 still had strong metabolic activity and maintained its viability after adsorbing Cr (VI), which is beneficial for biosorbent stability and reuse.

Erasable Domain Wall Current-Dominated Resistive Switching in BiFeO3 Devices with an Oxide-Metal Interface

Electric transport in the charged domain wall (CDW) region has emerged as a promising phenomenon for the development of next-generation ferro-resistive memory with ultrahigh data storage density. However, accurately measuring the conductivity of CDWs induced by polarization reversal remains challenging due to the polarization modulation of the Schottky barrier at the thin film-electrode interface, which could partially contribute to the collected "on" current of the device. Here, we propose carefully selecting an electrode that can suppress the effect of interfacial barrier modulation induced by polarization reversal, allowing the collected current mainly from the conductive CDWs. The experiment was conducted on epitaxial BiFeO₃(001) thin-film devices with vertical and horizontal geometries. Piezo-response force microscopy scanning showed the local polarization experienced 180° rotation to form CDWs under the vertical electric field. However, devices with SrRuO₃ epitaxial top electrodes still exhibit an interfacial barrier-dominated diode behavior, with the "on" current proportional to the electrode area. To identify the CDW current, more interfacial defects were introduced by the deposition of Pt top electrodes, which significantly enhanced charge injection for the compensation of the reversed polarization driven by the electric field, leading to the suppressed polarization modulation of the Schottky barrier height. It was observed that the current flow through Pt electrodes is significantly lower compared to that of SRO electrodes and appears to be primarily influenced by the electrode perimeter instead of the electrode area, indicating CDW-dominated conduction behavior in these devices. Planar nanodevices were further fabricated to support the quantitative investigation of the Pt electrode size-dependent "on" current with a linear fit of the current magnitude versus the CDW cross-sectional area. This work constitutes an essential part of understanding the role of the CDW current in ferro-resistive memory devices.

A Lightweight Authentication and Key Agreement Protocol for IoT-Enabled Smart Grid System

The IoT-enabled Smart Grid uses IoT smart devices to collect the private electricity data of consumers and send it to service providers over the public network, which leads to some new security problems. To ensure the communication security in a smart grid, many researches are focusing on using authentication and key agreement protocols to protect against cyber attacks. Unfortunately, most of them are vulnerable to various attacks. In this paper, we analyze the security of an existent protocol by introducing an insider attacker, and show that their scheme cannot guarantee the claimed security requirements under their adversary model. Then, we present an improved lightweight authentication and key agreement protocol, which aims to enhance the security of IoT-enabled smart grid systems. Furthermore, we proved the security of the scheme under the real-or-random oracle model. The result shown that the improved scheme is secure in the presence of both internal attackers and external attackers. Compared with the original protocol, the new protocol is more secure, while keeping the same computation efficiency. Both of them are 0.0552 ms. The communication of the new protocol is 236 bytes, which is acceptable in smart grids. In other words, with similar communication and computation cost, we proposed a more secure protocol for smart grids.

Gate-tunable heavy fermions in a moiré Kondo lattice

The Kondo lattice-a matrix of local magnetic moments coupled through spin-exchange interactions to itinerant conduction electrons-is a prototype of strongly correlated quantum matter1-4. Usually, Kondo lattices are realized in intermetallic compounds containing lanthanide or actinide1,2. The complex electronic structure and limited tunability of both the electron density and exchange interactions in these bulk materials pose considerable challenges to studying Kondo lattice physics. Here we report the realization of a synthetic Kondo lattice in AB-stacked MoTe2/WSe2 moiré bilayers, in which the MoTe2 layer is tuned to a Mott insulating state, supporting a triangular moiré lattice of local moments, and the WSe2 layer is doped with itinerant conduction carriers. We observe heavy fermions with a large Fermi surface below the Kondo temperature. We also observe the destruction of the heavy fermions by an external magnetic field with an abrupt decrease in the Fermi surface size and quasi-particle mass. We further demonstrate widely and continuously gate-tunable Kondo temperatures through either the itinerant carrier density or the Kondo interaction. Our study opens the possibility of in situ access to the phase diagram of the Kondo lattice with exotic quantum criticalities in a single device based on semiconductor moiré materials2-9.

Spontaneous Chirality Induction in the Assembly of a Single Layer 2-D Network with Switchable Pores

Although two dimensional (2-D) chiral sheet structures are attractive because of unique chemical and physical properties, single layer 2-D chiral network structures with switchable pore interior remain elusive. Here we report spontaneous chirality induction in a single layer 2-D network structure formed from the self-assembly of tetrapod azobenzene molecules. The chirality induction arises from multiple sublayers slipped in a preferred direction in which the sublayer consists of unidentical molecular arrangements in in-plane a and b directions, breaking both plane of symmetry and inversion symmetry. The protruded azobenzene units in the pore interior can be selectively isomerized upon UV irradiation, resulting in a reversible deformation of the chiral pores while maintaining 2-D frameworks. The chiral network can thus selectively entrap one enantiomer from a racemic solution with near perfect enantioselectivity, and then release upon UV irradiation.

Rapid capture and killing of bacteria by lyophilized nFeS-Hydrogel for improved healing of infected wounds

Due to their antibacterial activity, sulfur-containing nanomaterials are increasingly being developed into nanodrugs against bacterial infection. Nano iron sulfide (nFeS) is a new nanomaterial that can convert organic sulfur into inorganic sulfur, which has excellent antibacterial activity. However, the inorganic sulfur produced by nFeS can easily change its form or volatilize in aqueous solution, which may affect the efficacy of nFeS. We propose a new strategy to encapsulate nFeS in a hydrogel to preserve inorganic sulfides, and the macroporous structure of the hydrogel can capture bacteria to increase their interaction with nFeS. The in-depth characterization conducted in this study demonstrate that the water swelling characteristics of the lyophilized nFeS-Hydrogel and the ability to effectively maintain the antibacterial active ingredients in nFeS results in more effective killing of harmful bacteria than pure nFeS, while also prolonging the shelf life of antibacterial activity. We discovered that bacteria exhibit a unique mode of cell death when nFeS contained in hydrogels interacts with the cells by producing hydrogen polysulfanes, which increased intracellular ROS levels and reduced GSH levels. Furthermore, the nFeS-Hydrogel was found to reduce inflammation and exhibited excellent biocompatibility. Accordingly, the nFeS-Hydrogel has great application prospects as a fast excipient for clearing infection, reducing inflammation, and accelerating wound healing.

Transcriptome reveals the dysfunction of pancreatic islets after wound healing in severely burned mice

BACKGROUND

Severely burned patients have a higher risk of diabetes mellitus after healing, but its mechanism remains unclear. Therefore, the purpose of the study was to explore the influence of burns on pancreatic islets of mice after wound healing.

METHODS

Forty-two male C57BL/6 mice were randomized into a sham group and a burn group and subjected to sham treatment or a third-degree burn model of 30% total body surface area. Fasting blood glucose was detected weekly for 8 weeks after severe burns. Glucose-stimulated insulin secretion was measured 8 weeks post severe burns. Islets of the two groups were isolated and mRNA libraries were sequenced by the Illumina sequencing platform. The expressions of differentially expressed genes (DEGs) related to the cell cycle and the amounts of mitochondrial DNA were detected by quantitative real-time polymerase chain reaction after gene ontology, gene set enrichment analysis, and protein-protein network analysis. Hematoxylin-eosin staining of pancreatic tail tissue and adenosine triphosphate (ATP) assay of islets were performed.

RESULTS

The levels of fasting blood glucose were significantly higher within 8 weeks post severe burns. Glucose-stimulated insulin secretion was impaired at the eighth week post severe burns. Totally 128 DEGs were selected. Gene ontology and gene set enrichment analysis indicated that the pathways related to the cell cycle, protein processing, and oxidative phosphorylation were downregulated. The expressions of DEGs related to the cell cycle showed a consistent trend with mRNA sequencing data, and most of them were downregulated post severe burns. The cell mass of the burn group was less than that of the sham group. Also, the concentration of ATP and the amount of mitochondrial DNA were lower in the burn group.

CONCLUSION

In the model of severe-burned mice, disorders in glucose metabolism persist for 8 weeks after burns, which may be related to low islet cell proliferation, downregulation of protein processing, and less ATP production.

Transformation of Supramolecular Membranes to Vesicles Driven by Spontaneous Gradual Deprotonation on Membrane Surfaces

The various proteins and asymmetric lipid bilayers present in cell membranes form curvatures, resulting in structural transformations to generate vesicles. Fission and fusion processes between vesicles and cell membranes are reversible in living organisms. Although the transformation of a two-dimensional membrane to a three-dimensional vesicle structure is a common natural phenomenon, the lack of a detailed understanding at the molecular level limits the development of synthetic systems for functional materials. Herein, we report a supramolecular membrane system through donor-acceptor interactions using a π-deficient acceptor and π-rich donor as building blocks. The reduced electrostatic repulsion between ammonium cations and the spontaneously deprotonated neutral amino group induced anisotropic membrane curvature, resulting in membrane fission to form vesicles with a detailed understanding at the molecular level. Furthermore, the reversible transformation of vesicles to membranes upon changing the pH provides a novel synthetic system exhibiting both fission and fusion processes.

The very large n2EDM magnetically shielded room with an exceptional performance for fundamental physics measurements

We present the magnetically shielded room (MSR) for the n2EDM experiment at the Paul Scherrer Institute, which features an interior cubic volume with each side of length 2.92 m, thus providing an accessible space of 25 m³. The MSR has 87 openings of diameter up to 220 mm for operating the experimental apparatus inside and an intermediate space between the layers for housing sensitive signal processing electronics. The characterization measurements show a remanent magnetic field in the central 1 m³ below 100 pT and a field below 600 pT in the entire inner volume, up to 4 cm to the walls. The quasi-static shielding factor at 0.01 Hz measured with a sinusoidal 2 μT peak-to-peak signal is about 100 000 in all three spatial directions and increases rapidly with frequency to reach 10⁸ above 1 Hz.

A Cruciform Petal-like (ZIF-8) with Bactericidal Activity against Foodborne Gram-Positive Bacteria for Antibacterial Food Packaging

Most antibacterial nanomaterials used in food packaging act by releasing reactive oxygen species (ROS), which cannot efficiently have an inhibitory effect by penetrating the cell wall of Gram-positive Staphylococcus aureus. In this work, we used the cruciform petal-like zeolite imidazole framework-8 (ZIF-8) synthesized in the water phase which can release active Zn compounds in aqueous solution and exert a stronger inhibitory effect on S. aureus. The experimental results demonstrated that the aqueous cruciform petal-like ZIF-8 has the same photocatalytic activity as traditional ZIF-8 and can be applied in photocatalytic bacterial inactivation. The cruciform petal-like ZIF-8 was also shown to release active Zn compounds in aqueous solution with a better antibacterial effect against S. aureus, reaching 95% inactivation efficiency. The antibacterial effect was therefore 70% higher than that of traditional ZIF-8. Based on its excellent antibacterial properties, we loaded petal-like ZIF-8, PDA and PVA onto ordinary fibers to prepare ZIF-8-Film. The results further showed that ZIF-8-Film has a high filtration capacity, which can be used in antibacterial packaging material with the required air permeability. Moreover, ZIF-8-Flim can clean the surface on its own and can maintain a sterile environment. It is different from other disposable materials on the market in that it can be reused and has a self-disinfection function.

The inhibitory effect of LINC00261 upregulation on the pancreatic cancer EMT process is mediated by KLF13 via the mTOR signaling pathway

PURPOSE

The long noncoding RNA LINC00261 was reported to be involved in carcinogenesis and has been validated as a tumor suppressor in pancreatic cancer (PC); however, how LINC00261 is regulated has not been fully examined. Here, we attempted to investigate the upstream and downstream targets of LINC00261 in PC.

METHODS

LINC00261 expression in PC tissues was examined by the Gene Expression Omnibus (GEO) datasets and the Gene Expression Profiling Interactive Analysis (GEPIA) database. The quantitative reverse transcription polymerase chain reaction (qRT-PCR) assays were performed to detect the expression level of LINC00261 in PC cells. The location of LINC00261 in PC cells was identified by RNA fluorescence in situ hybridization (RNA-FISH). Cell Counting Kit-8 (CCK-8), cell apoptosis assay, transwell invasion and migration assays testified the critical role of LINC00261 in PC. The luciferase reporter assay was applied to confirm the binding of LINC00261 to its upstream transcription factor KLF13. The changes in LINC00261 related target protein levels were analyzed by Western blotting assay.

RESULTS

LINC00261 was significantly lower in PC tissues and was mainly concentrated in the nucleus. Overexpression of LINC00261 inhibited the invasion and migration of PC cells. Mechanistically, transcription factor KLF13 was confirmed to inhibit the epithelial-mesenchymal transition (EMT) process of PC cells by promoting the transcription of LINC00261 and suppressing the expression of metastasis-associated proteins, such as matrix metalloproteinase MMP2 and vimentin, thus inhibiting the metastasis of PC.

CONCLUSION

LINC00261 regulates PC cell metastasis through the "KLF13-LINC00261-mTOR-P70S6K1-S6" signaling pathway, which provides a significant set of potential PC therapeutic targets.

Multifunctional fluorescent gold nanoclusters with enhanced aggregation-induced emissions (AIEs) and excellent antibacterial effect for bacterial imaging and wound healing

To explore new alternatives to combat increasing risk of bacterial infection, in this work, a cationic antimicrobial peptide (HHC10) and glutathione (GSH) co-ligand protected ultra-small gold nanoclusters (Au NCs) was constructed by a simple one-pot method. The intrinsic luminescent property of GSH-protected Au NCs (Au_xGSH) endowed enhanced aggregation-induced emissions (AIEs) of co-ligand-protected Au NCs (Au_xGSH-HHC10), which exhibited a very strong orange luminescence. Based on the AIE effect, for one thing, Au_xGSH could be applied to rapidly and selectively detect Gram-positive bacteria. For another, Au_xGSH-HHC10 exhibited potential for multicolor imaging of both Gram-negative and Gram-positive bacteria. Besides, as-synthesized Au_xGSH-HHC10 could act as potent nanoantibiotics against both Gram-negative and Gram-positive bacteria, which could not only avoid drug tolerance but also be effective toward drug-resistance bacteria. The antibacterial mechanism indicated that the synergetic effect of the generation of reactive oxygen species (ROS), binding with DNA, and broad-spectrum antibacterial activity of HHC10 led to the membrane damage, depolarization, and interference of biological function, thus enhancing the antibacterial effect. More importantly, such an Au NCs could realize excellent therapeutic outcomes for wound healing in vivo, and showed good biocompatibility and biosafety toward health tissues. The results will provide a great potential for the application of Au NCs for imaging-guided antibacterial platform.

Capillary Electrophoresis Mass Spectrometry for Scalable Single-Cell Proteomics

Understanding the biochemistry of the cell requires measurement of all the molecules it produces. Single-cell proteomics recently became possible through advances in microanalytical sample preparation, separation by nano-flow liquid chromatography (nanoLC) and capillary electrophoresis (CE), and detection using electrospray ionization (ESI) high-resolution mass spectrometry (HRMS). Here, we demonstrate capillary microsampling CE-ESI-HRMS to be scalable to proteomics across broad cellular dimensions. This study established proof-of-principle using giant, ∼250-µm-diameter cells from embryos of the frog Xenopus laevis and small, ∼35-µm-diameter neurons in culture from the mouse hippocampus. From ∼18 ng, or ∼0.2% of the total cellular proteome, subcellular analysis of the ventral-animal midline (V11) and equatorial (V12) cells identified 1,133 different proteins in a 16-cell embryo. CE-HRMS achieved ∼20-times higher sensitivity and doubled the speed of instrumental measurements compared to nanoLC, the closest neighboring single-cell technology of choice. Microanalysis was scalable to 722 proteins groups from ∼5 ng of cellular protein digest from identified left dorsal-animal midline cell (D11), supporting sensitivity for smaller cells. Capillary microsampling enabled the isolation and transfer of individual neurons from the culture, identifying 37 proteins between three different cells. A total of 224 proteins were detected from 500 pg of neuronal protein digest, which estimates to a single neuron. Serial dilution returned 157 proteins from sample amounts estimating to about half a cell (250 pg protein) and 70 proteins from ca. a quarter of a neuron (125 pg protein), suggesting sufficient sensitivity for subcellular proteomics. CE-ESI-HRMS complements nanoLC proteomics with scalability, sensitivity, and speed across broad cellular dimensions.

Radiographic indexes in AP hip radiographs prior to total hip arthroplasty reveal candidates with low BMD

Using anteroposterior (AP) hip radiograph, we measured several indexes to investigate the association with bone mineral density (BMD) before THA and found a highly effective index to predict femoral BMD. This technique is helpful for both patients and clinicians to identify potential candidates with low BMD to whom DXA examination is particularly recommended.

INTRODUCTION

The purpose of the study is to identify patients with low bone mineral density (BMD) prior to total hip arthroplasty with the help of AP hip radiographs.

METHODS

Indexes on AP hip radiographs and T-scores from DXA examination of the lumbar spine and the affected hip were acquired from patients before THA. Indexes measured on AP hip radiographs including the canal calcar ratio (CCR), canal flare index (CFI), morphological cortical index (MCI), canal bone ratio (CBR), and canal bone area ratio (CBAR). The relevance between indexes and the T-score of femora was evaluated by correlation analysis, and the diagnostic value of indexes for osteopenia was examined by receiver operating characteristic (ROC) curves.

RESULTS

A total of 81 patients were included. The average value of CBR-7, CBR-10, and CBAR (7-10) were highly related to the T-score of femora (r =  - 0.592, r =  - 0.634, and r =  - 0.631, respectively, p < 0.0001). Results of the intra- and interobserver variation assessment was excellent. CBR-7, CBR-10, and CBAR (7-10) were significantly different between the non-osteopenia and osteopenia groups (p < 0.0001). CBR-10 had the biggest area under curve (AUC), means the great diagnostic value for osteopenia in the proximal femora (AUC = 0.821, cutoff value = 0.3805).

CONCLUSION

The canal bone ratio at 10 × 10^-2 m under the level of the lesser trochanter proved to be a great indicator of femoral osteopenia. Trial registration Chinese Clinical Trail Registry, ChiCTR2000041016. Registered 16 December 2020-Retrospectively registered, http://www.chictr.org.cn/listbycreater.aspx .

STAT3 exerts pro-tumor and anti-autophagy roles in cervical cancer

Background

STAT3 plays an important role in cervical cancer. LC3B, the most potential molecular biomarker of autophagy that may promote or inhibit cancer progression, can be downregulated by STAT3. However the role of STAT3 in the autophagy of cervical cancer remains unclear.

Purpose

This study aimed to evaluate the relationship between STAT3 and LC3B in protein level, and verify whether STAT3 promotes proliferation, migration and plate colony formation by inhibiting autophagy of cervical cancer cells through bcl2-beclin1 axis.

Results

STAT3 was overexpressed in cervical cancer tissues, and negatively correlated with the expression level of LC3B. STAT3 knockout or knockdown significantly increased the autophagy level and decreased proliferation, migration, plate colony formation and subcutaneous tumorigenesis of cervical cancer cells in vitro and in vivo. STAT3 is known to mediate autophagy through Bcl2-Beclin1 complex. Bcl2 was positively whereas Beclin1 negatively correlated with STAT3 expression, indicating that Bcl2-Beclin1 complex involved in this transition.

Conclusion

STAT3 may upregulate the autophagy level of cervical cancer cells through the Bcl2-Beclin1 axis. This indicates that STAT3 may be an important prognostic and therapeutic target for cervical cancer.

Photocurrent-driven transient symmetry breaking in the Weyl semimetal TaAs

Symmetry plays a central role in conventional and topological phases of matter, making the ability to optically drive symmetry changes a critical step in developing future technologies that rely on such control. Topological materials, like topological semimetals, are particularly sensitive to a breaking or restoring of time-reversal and crystalline symmetries, which affect both bulk and surface electronic states. While previous studies have focused on controlling symmetry via coupling to the crystal lattice, we demonstrate here an all-electronic mechanism based on photocurrent generation. Using second harmonic generation spectroscopy as a sensitive probe of symmetry changes, we observe an ultrafast breaking of time-reversal and spatial symmetries following femtosecond optical excitation in the prototypical type-I Weyl semimetal TaAs. Our results show that optically driven photocurrents can be tailored to explicitly break electronic symmetry in a generic fashion, opening up the possibility of driving phase transitions between symmetry-protected states on ultrafast timescales.

Quantum anomalous Hall effect from intertwined moiré bands

Electron correlation and topology are two central threads of modern condensed matter physics. Semiconductor moiré materials provide a highly tuneable platform for studies of electron correlation^1-12. Correlation-driven phenomena, including the Mott insulator^2-5, generalized Wigner crystals^2,6,9, stripe phases¹⁰ and continuous Mott transition^11,12, have been demonstrated. However, non-trivial band topology has remained unclear. Here we report the observation of a quantum anomalous Hall effect in AB-stacked MoTe₂ /WSe₂ moiré heterobilayers. Unlike in the AA-stacked heterobilayers¹¹, an out-of-plane electric field not only controls the bandwidth but also the band topology by intertwining moiré bands centred at different layers. At half band filling, corresponding to one particle per moiré unit cell, we observe quantized Hall resistance, h/e² (with h and e denoting the Planck's constant and electron charge, respectively), and vanishing longitudinal resistance at zero magnetic field. The electric-field-induced topological phase transition from a Mott insulator to a quantum anomalous Hall insulator precedes an insulator-to-metal transition. Contrary to most known topological phase transitions¹³, it is not accompanied by a bulk charge gap closure. Our study paves the way for discovery of emergent phenomena arising from the combined influence of strong correlation and topology in semiconductor moiré materials.