Simple Modification Research Articles

DNA Robots for CRISPR/Cas12a Activity Management and Universal Platforms for Biosensing.

The CRISPR/Cas12a system is a revolutionary genome editing technique that is widely employed in biosensing and molecular diagnostics. However, there are few reports on precisely managing the trans-cleavage activity of Cas12a by simple modification since the traditional methods to manage Cas12a often require difficult and rigorous regulation of core components. Hence, we developed a novel CRISPR/Cas12a regulatory mechanism, named DNA Robots for Enzyme Activity Management (DREAM), by introducing two simple DNA robots, apurinic/apyrimidinic site (AP site) or nick on target activator. First, we revealed the mechanism of how the DREAM strategy precisely regulated Cas12a through different binding affinities. Second, the DREAM strategy was found to improve the selectivity of Cas12a for identifying base mismatch. Third, a modular biosensor for base excision repair enzymes based on the DREAM strategy was developed by utilizing diversified generation ways of DNA robots, and a multi-signal output platform such as fluorescence, colorimetry, and visual lateral flow strip was constructed. Furthermore, we extended logic sensing circuits to overcome the barrier that Cas12a could not detect simultaneously in a single tube. Overall, the DREAM strategy not only provided new prospects for programmable Cas12a biosensing systems but also enabled portable, specific, and humanized detection with great potential for molecular diagnostics.

Controllable process to construct robust superhydrophobic membrane with tunable pore size for efficient separation of oil-water mixtures and emulsions

The increase in the discharge of industrial oily wastewater poses a threat to the environment and human health. Thus, the treatment of oily wastewater has become a focus of current research. The superhydrophobic surface derived from the lotus effect provides an effective direction for oil-water separation. Based on this, the authors reported a tunable superhydrophobic stainless steel separation mesh with a water contact angle of 155° through simple electrodeposition and modification with a fluorine-free modifier. The separation mesh with different surface morphology, by controlling different electrodeposition time and current, is able to achieve oil-water separation with super flux up to 51561 L/(m2·h) in heavy oil/water mixture and high-efficiency over 99.5% in water-in-oil emulsion. This controllable process constructs superhydrophobic membrane with tunable pore size, which is capable of separating heavy oil/water mixtures and water-in-oil emulsions depending on the process. This proposal is suggestive in the field of oil-water separation.

Silver nanoparticles coated cellulose-based flexible membrane with excellent UV resistance, high infrared reflection and water resistance for personal thermal management

Designing of a green and multifunctionally integrated cellulose-based flexible wearable material with personal thermoregulation, water and ultraviolet (UV) resistance is essential for the development of personal thermal management and smart textiles. Herein, a hydrophobic silver nanoparticles cellulose-based membrane (H-AgNPs/CEPCM) was prepared through simple solution blending, spin-coating process and chemical vapor modification. The prepared membrane exhibited excellent UV resistance due to the synergistic effect of carbon quantum dots (CQDs) as well as UV-absorbing functional groups. The spin-coated AgNPs layer with high infrared reflectivity has great radiant insulation, and temperature was reduced by 3.4 °C compared with H-CEPCM in indoor environment. Furthermore, the mechanical properties of H-AgNPs/CEPCM were significantly improved by the introduction of amide and ether bonds, as well as a large number of hydrogen bonds. This led to a tensile strength of 23.21 MPa and an elongation at break of 16.57 %, while also providing water resistance. Additionally, the H-AgNPs/CEPCM exhibited outstanding thermal stability and hydrophobicity. This work may provide a feasible and promising strategy for the construction of multifunctional integrated cellulose membrane materials for radiant insulation, outdoor textiles and novel UV protection applications.

Moisture resistance improvement of carbonaceous fibers for antistatic coating by modification with long carbon chain silane

Although the general carbon fibers are very stable, low-temperature carbonized carbonaceous fibers were sensitive to moisture, which would lead to unstable electrical conductivity, and seriously endanger the antistatic properties of antistatic coating when carbonaceous fibers were used as conductive filler. In this work, a simple dipping modification is proposed to improve the stability of fiber resistivity by using a long carbon chain silane coupling agent (hexadecyltrimethoxysilane) to perform surface moisture-proof treatment on carbonaceous fibers. The modification was demonstrated to significantly improve the stability of fiber resistivity by accelerated experiments in hygrothermal and salt spray environments. After 72 h treatment in hygrothermal environment, the increase percentage of untreated carbonaceous fiber resistivity reached 70%. Nevertheless, that of CF@KH1631-6 was 40%. Good hydrophobicity was achieved at a concentration of 6 wt%, water contact angle increasing from 135.6° to 152.2°. Furthermore, the whole preparation process had the potential of large-scale industrial production and application.

Thiophene organic molecules in-situ grafted mesoporous carbon promote high stable and high kinetic lithium-sulfur batteries

Lithium‑sulfur (LiS) batteries are widely regarded as the promising battery system that meet the high energy density requirement up to 500 Wh kg−1. However, the serious shuttle effect and poor reaction kinetics seriously slow down the practical application of LiS batteries. For both solid and liquid LiS batteries, holding sulfides by adsorptive and catalytic host is an indispensable strategy to improve their reaction kinetic. Carbonaceous materials have been widely used as the sulfur hosts due to their easy controlled morphologic, lightweight and low-cost. However, these advantages were usually shelved by their low wettability and poor adsorption to polysulfides. In this study, a high active and stable carbonaceous host was synthesized by in-situ grafting thiophene molecules on mesoporous carbon. Sulfur was further bond on the thiophene molecules to form an extremely stable electrode structure. More importantly, the electron-rich conjugated thiophene molecules, which with high ionic and electronic conductivity, can effectively improve the reaction kinetics of LiS batteries. This simple and reproducible cathode modification strategy provides a reliable reference for realizing the practical application of LiS batteries.

Experimental and simulation studies on the no‐load performance assessment of a domestic solar dryer

AbstractSolar dryers have been tested with various simple and complex design modifications for better efficiencies. This article attempts to investigate the effect of a very simple design modification on the no‐load performance of a natural convection domestic solar dryer (NCDSD). A direct‐type domestic solar dryer has been developed with an air cavity surrounding the drying chamber. To compare the effect of air cavity, a domestic solar dryer without air cavity has also been developed and both the dryers were tested simultaneously under the climate of Hisar, India. The values of thermal efficiency were calculated along with convective heat transfer coefficient from absorber plate to the drying air. Both the dryers were also analyzed by developing finite element models in COMSOL multiphysics computer software. The no‐load thermal efficiency for the domestic solar dryer without and with air cavity was found to be 22.68% and 34.08%, respectively. The values of coefficient of correlation for modeled and actual drying tray temperatures for dryer without and with air cavity were 0.980466 and 0.9833917, respectively. The proposed finite element model would be helpful in the design and development of NCDSDs.

Significantly boosting photocatalytic degradation efficiency through simple Br modification

Significantly boosting photocatalytic degradation efficiency through simple Br modification

Niobium Oxide Photocatalytically Oxidizes Ammonia in Water at Ambient Conditions

Ammonia contamination in water is a significant environmental issue since it is toxic and leads to eutrophication. Photocatalysis has been investigated as a strategy for ammonia degradation but can potentially form toxic nitrite (NO2 – ) and nitrate (NO3 – ) byproducts. This work reports on the ability of niobium oxide (Nb2O5) to photocatalytically oxidize aqueous-phase ammonia (NH3). Whereas as-synthesized Nb2O5 showed little catalytic activity (< 1% NH3 conversion after 6 h of UV-C irradiation, at room temperature and atmospheric pressure, and under O2 headspace), Nb2O5 treated in basic solution (OH-Nb2O5) was able to photocatalytically degrade NH3 at ca. 9% conversion after six hours, with ca. 70% selectivity to the desired N2, with a first-order rate constant of ca. 12 times higher than the as synthesize catalyst (1.6 × 10–3 min–1 vs. 2.0 × 10–2 min–1). Raman spectroscopic analysis indicated the presence of terminal Nb=O species after base treatment of Nb2O5, implicating them as catalytically active sites. These results underscore how a simple structural modification can significantly affect photocatalytic activity for aqueous ammonia oxidation.

Development of strong and high-barrier food packaging films from cyclic-anhydride modified bacterial cellulose

Using various cyclic anhydrides as the esterifying agents and dimethyl sulfoxide as the solvent, water vapor/oxygen/bacteria resistant, strong, and biodegradable bacterial cellulose films were fabricated using a simple, efficient, and low-pollution surface modification protocol.

Augmentation of inductive effects through short range intramolecular hydrogen bonds for the improvement of cooperativity of trimeric rosettes

Three key design elements improve the binding strength of trimeric rosettes: the direction of hydrogen bonds, the addition of groups with inductive effects, and the presence of ambifunctional intramolecular hydrogen bonds between the substituents.

Glucosylation endows nanoparticles with TLR4 agonist capability to trigger macrophage polarization and augment antitumor immunity

Carbohydrates have emerged as promising candidates for immunomodulation, however, how to present them to immune cells and achieve potent immunostimulatory efficacy remains challenging. Here, we proposed and established an effective way of designing unique glyconanoparticles that can amplify macrophage-mediated immune responses through structural mimicry and multiple stimulation. We demonstrate that surface modification with glucose can greatly augment the immunostimulatory efficacy of nanoparticles, comparing to mannose and galactose. In vitro studies show that glucosylation improved the pro-inflammatory efficacy of iron oxide nanoparticles (IONPs) by up to 300-fold, with the immunostimulatory activity of glucosylated IONPs even surpassing that of LPS under certain conditions. In vivo investigation show that glucosylated IONPs elicited increased antitumor immunity and achieved favorable therapeutic outcomes in multiple murine tumor models. Mechanistically, we proposed that glucosylation potentiated the immunostimulatory effect of IONPs by amplifying toll-like receptors 4 (TLR4) activation. Specifically, glucosylated IONPs directly interacted with the TLR4-MD2 complex, resulting in M1 macrophage polarization and enhanced antitumor immunity via activation of NF-κB, MAPK, and STAT1 signaling pathways. Our work provides a simple modification strategy to endow nanoparticles with potent TLR4 agonist effects, which may shed new light on the development of artificial immune modulators for cancer immunotherapy.

One-step fast fabrication of multi-layer quantum dot diffusion plate for stable display and ultra-long life, a novel quantum dot packaging strategy

Quantum dots (QDs), renowned for their distinctive optical and physical attributes, are extensively employed in diverse fields such as lighting, displays, electronics, sensors, and solar cells. Nonetheless, the susceptibility to light, oxygen, and moisture is a major obstacle to the development of QDs. Achieving simple, efficient, and universal modification or encapsulation for enhanced stability remains a challenge. Herein, a one-step fast fabrication of multi-layer quantum dot diffusion plate (QD-DP) with excellent barrier and optical properties was proposed, which is alternately stacked by MS-EVOH and MS-QDs layers. The barrier phase morphology undergoes a fiber-flake transition induced by the bidirectional tensile force field during multiplication, and layer-by-layer encapsulation synergistically enhances the barrier performance, photo-oxygen stability, thermal-oxygen stability, and fluorescence lifetime of QD-DP in backlight applications. Under high-power UV irradiation, the fluorescence intensity ofMS/MS-QD 128L dropped to 90 % (T90) in only about 10 minutes, while the T90 of MS-E/MS-QD 128L was close to 216 hours, improved more than 1200 times. Concurrently, the quantum dot diffusion plate (QD-DP), characterized by an alternating multi-layer structure, demonstrated an elevated backlight color gamut value of ∼ 120 % NTSC, outperforming conventional quantum dot light emitting diodes (QLED). Compared with existing QDs backlight modules, a simpler structure, more efficient preparation process, and longer fluorescence lifetime of QD-DP were achieved.Moreover, unlike prevalent modification or packaging technologies that only target specific QD types, our alternating multilayer coextrusion packaging technology is applicable to all kinds of QDs and is simple, efficient, and universal.It was believed that this work could provide new opportunities for all kinds of QDs encapsulation and application in many fields and will be the dawn of large-scale commercialization of QDs.

Bidirectional Converter System in Dual Active Bridge Topology for a Hydrogen Tank

The paper presents a Dual Active Bridge (DAB) converter operating as an interface between the LiFePo4 battery and the fuel cell/hydrogen generator. The hydrogen tank can increase the stored energy of the battery system. Among the main requirements for a converter is the need to transfer power of up to 10 kW and operate with widely changing voltages on both sides of the converter. The design of the power electronic part and passive components of the converter is deeply discussed. Next, the influence of the wide voltage range on the operation of the converter is depicted, including its impact on power losses and current values. Different topological modifications for power loss reduction are presented and experimentally verified. Finally, a simple modification of the control system, giving the possibility of increasing efficiency, is briefly presented.

Mobilized Electrospray Device for On-Tissue Chemical Derivatization in MALDI-MS Imaging.

Applying solutions of a matrix or derivatization agent via microdroplets is a common sample preparation technique for matrix-assisted laser desorption/ionization-mass spectrometry imaging (MALDI-MSI) experiments. Mobilized nebulizer sprayers are commonly used to create a homogeneous matrix or reagent layer across large surfaces. Electrospray devices have also been used to produce microdroplets for the same purpose but are rarely used for large tissues due to their immobility. Herein, we present a movable electrospray device that can be used for large tissue sample preparation through a simple modification to an automatic commercial nebulizer device. As demonstrated for on-tissue chemical derivatization (OTCD) with Girard's reagent T using a mimetic tissue model, the sprayer has the additional benefit of being able to investigate reaction acceleration in OTCD when comparing electrostatically charged spray to electrostatically neutral spray. Finally, MALDI-MSI of fatty aldehydes is successfully demonstrated in rat brain tissues using this device for both OTCD and matrix application.

DNA recovery from biological material on mini tapes using a simple extraction buffer and solid phase reversible immobilisation (SPRI) purification

In this study, we compare the performance of a simple PVP extraction method with a commercially available and widely used kit for recovering DNA from adhesive tapes. This novel method shows almost 60% higher DNA recovery from blood deposits on SceneSafe Fast™ minitapes when compared to the PrepFiler™ BTA Forensic DNA Extraction Kit. We also demonstrate how a simple modification of the magnetic bead-based purification step can lead to better recovery and removal of PCR inhibitors.

Electrospun Perovskite Nanofiber/Poly(vinylidene fluoride-cohexafluoropropylene) Quasi-Solid-State for Lithium-Metal Batteries

Solid-state lithium-metal batteries (SSLMBs) with a composite solid electrolyte (CSE) have great potential for achieving both high energy density and high safety and are thus promising next-generation energy storage devices. Nevertheless, the key bottleneck issues are a high electrode/electrolyte interface resistance and the limited Li+ conductivity of the solid electrolyte. A free-standing CSE consisting of Li0.33La0.557TiO3 (LLTO) nanofibers, poly(vinylidene fluoride-co-hexafluoropropylene (PVDF-HFP), and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) is developed for room-temperature SSLMB applications. First, the calcination temperature for the electrospun LLTO precursor is optimized. The effects of the LLTO filler fraction and the morphology (spherical vs. fibrous) on CSE conductivity are examined. Furthermore, a succinonitrile interlayer (SNI), which is composed of succinonitrile, fluoroethylene carbonate, and LiTFSI, is developed to lower the high interfacial impedance. Compared to a conventional ester-based interlayer (EBI), SNI effectively decreases the Li//CSE interfacial resistance and suppresses unfavorable interfacial side reactions. The derived LiF- and CF x -rich protective layer on the Li electrode surface prevents the accumulation of dead Li and the excessive formation of SEI. Importantly, the dehydrofluorination reactions of PVDF-HFP are adequately mitigated, and a highly conductive and stable Li//CSE interface is achieved owing to SNI. Accordingly, both Li//CSE@SNI//Li and Li//CSE@SNI//LiFePO4 cells exhibit superior charge-discharge properties and cyclability to those of an EBI counterpart. A simple and low-cost interface modification strategy to enhance the performance of SSLMBs is proposed in this paper.

INCHEM-Py v1.2: a community box model for indoor air chemistry

Abstract. The Indoor CHEMical model in Python, INCHEM-Py, is an open-source and accessible box model for the simulation of the indoor atmosphere and is a refactor (rewrite of source code) and significant development of the INdoor Detailed Chemical Model (INDCM). INCHEM-Py creates and solves a system of coupled ordinary differential equations that include gas-phase chemistry, surface deposition, indoor–outdoor air change, indoor photolysis processes and gas-to-particle partitioning for three common terpenes. It is optimised for ease of installation and simple modification for inexperienced users, while also providing unfettered access to customise the physical and chemical processes for more advanced users. A detailed user manual is included with the model and updated with each version release. In this paper, INCHEM-Py v1.2 is introduced, and the modelled processes are described in detail, with benchmarking between simulated data and published experimental results presented, alongside discussion of the parameters and assumptions used. It is shown that INCHEM-Py achieves excellent agreement with measurements from an experimental campaign which investigate the effects of different surfaces on the concentrations of different indoor air pollutants. In addition, INCHEM-Py shows closer agreement to experimental data than INDCM. This is due to the increased functionality of INCHEM-Py to model additional processes, such as deposition-induced surface emissions. A comparative analysis with a similar zero-dimensional model, AtChem2, verifies the solution of the gas-phase chemistry. Published community use cases of INCHEM-Py are also presented to show the variety of applications for which this model is valuable to further our understanding of indoor air chemistry.

Principle and applications of CRISPR/Cas system

With the continuous in-depth research and exploration of the CRISPR/Cas9 system by researchers, people's ability to edit biological genes is also constantly improving. In recent years, gene editing technology as a hot technology has been paid more and more attention, it has played an important role in crop breeding, disease treatment, molecular diagnosis and other aspects. Among the gene editing technologies that have been developed, the emerging CRISPR/Cas technology gene editing system has become the most widely used gene editing technology at present. Compared with the first two generations of gene-editing technologies: ZFN and TALEN, CRISPR/Cas system has the advantages of short cycle, high efficiency, low cost, and has great potential for the development of animal and plant breeding. The development of CRISPR/Cas9 technology has promoted the progress of modern life sciences. With these tools for efficient, simple, and precise genome modification, transcriptional regulation, and epigenetic editing, CRISPR systems have the potential to revolutionize genetics, medicine, and agriculture. In this review, the basic principle of CRISPR/Cas technology and its application will be introduced and illustrated.

Selective square wave voltammetric determination of tinidazole in pharmaceutical formulations, and human urine samples using poly(bis(2,2′-bipyridine)diresorcinolateruthenium(III) chloride) modified glassy carbon electrode

This study reports the determination of Tinidazole (TDL) using a modified glassy carbon electrode, poly(bis(2,2′-bipyridine)diresorcinateruthenium(III) chloride) (poly(BBPDRRuC)/GCE) by a newly synthesized mixed ligand complex, bis-(2,2′-bipyridine)diresorcinateruthenium(III) chloride(BBPDRRuC). Electrochemical impedance spectroscopy (EIS) and cyclic voltamettry (CV) results demonstrated modification of the surface of the electrode by a conductive, and electroactive polymer film leading to an enhanced effective electrode surface area and their electrocatalytic role. Appearance of an irreversible reductive peak at much reduced potential with four folds current enhancement at poly(BBPDRRuC)/GCE showed the catalytic effect of the modifier by reduction of TDL. Square wave voltammetry current response of poly(BBPDRRuC)/GCE showed linear dependence on concentration of TDL in the range 10−8˗ 3.0 × 10−4 M with LoD and LoQ of 2.5 nM, and 8.2 nM, respectively. The TDL level in the studied tablet brands were in the range 96.6–101.1% of their labeled values. Spike recovery results in tablet, and human blood serum samples were in the range 98.3˗100.4%, and 98.85 ˗ 99.89%, respectively, and interference recovery results with <4.5% error. The developed method required a simple electrode modification step, a relatively chip, an easily available and non-toxic modifier, provides the least LoD, and reasonably wider linear dynamic range, and had excellent performance for the determination of TDL in tablet formulation and serum samples as compared with recently reported voltammetric methods.

Outstanding Energy-Storage Density Together with Efficiency of above 90% via Local Structure Design.

Dielectric ceramic capacitors with high recoverable energy density (Wrec) and efficiency (η) are of great significance in advanced electronic devices. However, it remains a challenge to achieve high Wrec and η parameters simultaneously. Herein, based on density functional theory calculations and local structure analysis, the feasibility of developing the aforementioned capacitors is demonstrated by considering Bi0.25Na0.25Ba0.5TiO3 (BNT-50BT) as a matrix material with large local polarization and structural distortion. Remarkable Wrec and η of 16.21 J/cm3 and 90.5% have been achieved in Bi0.25Na0.25Ba0.5Ti0.92Hf0.08O3 via simple chemical modification, which is the highest Wrec value among reported bulk ceramics with η greater than 90%. The examination results of local structures at lattice and atomic scales indicate that the disorderly polarization distribution and small nanoregion (∼3 nm) lead to low hysteresis and high efficiency. In turn, the drastic increase in local polarization activated via the ultrahigh electric field (80 kV/mm) leads to large polarization and superior energy storage density. Therefore, this study emphasizes that chemical design should be established on a clear understanding of the performance-related local structure to enable a targeted regulation of high-performance systems.