Rapid Modification Research Articles

Efficient electroporation in primary cells with PEDOT:PSS electrodes.

Precise and efficient delivery of macromolecules into cells enhances basic biology research and therapeutic applications in cell therapies, drug delivery, and personalized medicine. While pulsed electric field electroporation effectively permeabilizes cell membranes to deliver payloads without the need for toxic chemical or viral transduction agents, conventional bulk electroporation devices face major challenges with cell viability and heterogeneity due to variations in fields generated across cells and electrochemistry at the electrode-electrolyte interface. Here, we introduce the use of microfabricated electrodes based on the conducting polymer poly(3,4-ethylenedioxythiophene) doped with polystyrene sulfonate (PEDOT:PSS), which substantially increases cell viability and transfection efficiency. As a proof of concept, we demonstrate the enhanced delivery of Cas9 protein, guide RNA, and plasmid DNA into cell lines and primary cells. This use of PEDOT:PSS enables rapid modification of difficult-to-transfect cell types to accelerate their study and use as therapeutic platforms.

Unleashing the Potential of CRISPR/Cas9 Genome Editing for Yield-Related Traits in Rice

Strategies to enhance rice productivity in response to global demand have been the paramount focus of breeders worldwide. Multiple factors, including agronomical traits such as plant architecture and grain formation and physiological traits such as photosynthetic efficiency and NUE (nitrogen use efficiency), as well as factors such as phytohormone perception and homeostasis and transcriptional regulation, indirectly influence rice grain yield. Advances in genetic analysis methodologies and functional genomics, numerous genes, QTLs (Quantitative Trait Loci), and SNPs (Single-Nucleotide Polymorphisms), linked to yield traits, have been identified and analyzed in rice. Genome editing allows for the targeted modification of identified genes to create novel mutations in rice, avoiding the unintended mutations often caused by random mutagenesis. Genome editing technologies, notably the CRISPR/Cas9 system, present a promising tool to generate precise and rapid modifications in the plant genome. Advancements in CRISPR have further enabled researchers to modify a larger number of genes with higher efficiency. This paper reviews recent research on genome editing of yield-related genes in rice, discusses available gene editing tools, and highlights their potential to expedite rice breeding programs.

Rapid surface modification of PEEK by ambient temperature sulfonation for high shelf-life biomedical applications

The aim of this study is to develop a rapid, simple, and economical surface treatment process for Poly (ether-ether-ketone) (PEEK) using concentrated sulfuric acid. PEEK is a biocompatible material, with a bonelike elastic modulus and is mechanically superior to other implant materials like titanium, stainless steel etc. This property brings PEEK to limelight as a promising alternative for bone implants. However, a strong challenge is observed of osseointegration mainly due to its inert surface behavior and poor hydrophilicity. Chemical surface modification is considered as one of the best ways to bioactivate the PEEK surface. In this work, two different sulfonation treatment methodologies have been designed and the effect of reaction time is systematically studied over its changing surface properties and favorable cellular growth. In one treatment, only rapid sulfonation is implemented while in other treatment processes, scaffolds are treated with NaOH solution to terminate the sulfonation process. The modified PEEK surface is next evaluated using Fourier transform infra-red spectroscopy (FTIR), contact angle, optical profilometer and scanning electron microscopy to ascertain its behavior. The modified surface is observed to possess higher hydrophilicity, higher surface roughness and high porosity. No significant difference in hydrophilicity is observed for over a month once treated, showing permanency in modification. A 90 second treatment is observed to have the highest hydrophilicity and thus selected for cellular integration studies. No sign of cell toxicity was observed in the modified surfaces, which also showed improved protein adsorption, cell viability, cell adhesion, and proliferation compared to untreated PEEK.The proposed chemical modifications are promising techniques for a rapid, easy, and economical bioactivation of PEEK polymer for improved cellular activity.

Exploring the reactivity and interactions of a poly(fluorene‐co‐tetrazine)‐conjugated polymer with Single‐walled Carbon Nanotubes

AbstractConjugated tetrazine‐containing polymers that undergo inverse electron demand Diels‐Alder (IEDDA) reactions with trans‐cyclooctenes are interesting not only for their intrinsic optoelectronic properties, but also their interactions with π‐conjugated surfaces. Here, we prepared a series of poly(fluorene‐co‐tetrazine) polymers and carried out IEDDA reactions to decorate them with hydroxyl, hexadecyl, or triethylene glycol side chains. The polymers were investigated pre‐ and post‐IEDDA coupling in terms of their ability to disperse single‐walled carbon nanotubes (SWNTs) in organic solvent. It was found that polymer molecular weight, side chain structure, and degree of conjugation all impacted the quality of SWNT dispersions. While the starting poly(fluorene‐co‐tetrazine) polymer produced concentrated dispersions, the post‐IEDDA polymer containing dihydropyridazine groups did not produce dispersions of equal concentration. However, upon oxidation to the fully aromatic pyridazines, the polymers regained their ability to form concentrated dispersions. Furthermore, the post‐IEDDA polymers exhibited increased selectivity toward metallic SWNTs relative to the starting polymer. Due to the efficiency of the IEDDA reaction, it was also possible to use this chemistry to derivatize the nanotube complex with poly(fluorene‐co‐tetrazine) post‐dispersion. Overall, this work demonstrates the first use of reactive polytetrazines to disperse SWNTs, allowing rapid modification of polymer‐nanotube complexes.

A novel approach to investigate the mechanism of electroconvulsive therapy in the treatment of major depression disorder: Diffusion kurtosis imaging

BackgroundMajor depression disorder (MDD) exhibits a high global incidence; however, its pathogenesis remains elusive. In this prospective study, we employed diffusion kurtosis imaging (DKI) to investigate changes in brain function among patients with MDD both pre- and post-electroconvulsive therapy (ECT). MethodsWe divided a sample of 22 MDD patients into ECT group, which received six treatments over a span of two weeks, and control group (n = 12). DKI scanning was performed before and after treatment. The Hamilton Depression Rating Scale (HAMD) and Life Satisfaction Rating Scale (LSRS) were administered to assess depressive symptoms at baseline, on the 14th day, and at month three. ResultsSignificant differences were found between group, time and time × group in terms of HAMD score and LSRS score. In the ECT group compared to pre- ECT measurement, changes in mean diffusivity (MD), fractional Anisotropy (FA), mean kurtosis (MK), radial kurtosis (RK), FA of kurtosis (KA), and anxia kurtosis (AK) value were detected in specific regions such as the frontal, temporal lobe, and hippocampus. In the control group only MD and RK value increased in a limited number of area. ConclusionsECT holds the potential to elicit neuroplasticity in the brain, facilitating rapid structural modifications and amelioration of depressive symptoms in patients with MDD.

Stability optimization of iron-based catalysts: Application of Cr-enriched alloy steel catalyst in ozonation pharmaceutical wastewater

Catalytic ozonation for advanced treatment of industrial wastewater has proved to be effective, and the stability of the catalyst is crucial for the long-term application of the ozonation process in practical engineering. In this study, the electrochemical characteristics of four iron (Fe) shavings: alloy steels (38CrMoAl and 40Cr) and carbon steels (A3 and 45#) were investigated, and a new citric acid-optimized H2O2 modification method was proposed. The low open circuit potential (OCP) of carbon steels indicated that they were more likely to be oxidized therefore required shorter modification times. The higher the OCP of alloy steels, the higher H2O2 concentration was required to enhance modification efficiency. By adding citric acid, the rapid modification of alloy steel was achieved, and the catalysts exhibited lower passivation current (Ip), indicating a lower rate of substrate loss and a longer lifetime of alloy steel catalysts. Furthermore, chromium (Cr) enrichment occurred in the oxide layer of alloy steel catalysts. The Cr/Fe (atomic ratio) in oxide layer for 38CrMoAl and 40Cr increased from 0.018 to 0.040 and from 0.010 to 0.037, respectively. The presence of CrOOH and Cr2O3 within the oxide layer reinforced the layer’s overall structural integrity and enhanced its protection for the internal substrate, making the catalysts more resistant to adapt to high-salinity wastewater. Through laboratory tests, it was found that among the four catalysts, 38CrMoAl showed the highest stability and good catalytic activity with low Fe loss concentration. Therefore, the pilot-scale application effect of 38CrMoAl catalyst was evaluated. In the advanced treatment of pharmaceutical wastewater, chemical oxygen demand (COD) and total organic carbon (TOC) removals were 56.3% and 32.4%, respectively. These results showed that the stability of catalyst can be improved by optimizing the selection of steel, and the introduction of citric acid achieved Cr enrichment effect and amplified the potential stability advantage of alloy steel. The research provides guidance on raw material selection for catalyst preparation to different industries' wastewater treatment, especially in high-salinity wastewater ozonation treatment, which can realize the long-term stable application of catalyst.

Robust control of a wind energy conversion system: FPGA real-time implementation

This study employs an FPGA board to implement a robust control technique for wind energy conversion systems (WECS). This approach facilitates extensive testing and validation of the control system across diverse wind conditions, utilizing the FPGA's parallel processing capabilities and advanced control algorithms. This method ensures robustness against nonlinearities and system uncertainties. FPGA-in-the-loop (FIL) testing provides precise and effective simulation results, enabling rapid prototyping and iterative modifications of control algorithms. The effectiveness of the robust control strategy is confirmed by FIL findings, demonstrating significant improvements in WECS stability and efficiency. Furthermore, the study highlights the strategy's potential to enhance WECS reliability and efficiency in real-world applications.

The Open Force Field Initiative: Open Software and Open Science for Molecular Modeling.

Force fields are a key component of physics-based molecular modeling, describing the energies and forces in a molecular system as a function of the positions of the atoms and molecules involved. Here, we provide a review and scientific status report on the work of the Open Force Field (OpenFF) Initiative, which focuses on the science, infrastructure and data required to build the next generation of biomolecular force fields. We introduce the OpenFF Initiative and the related OpenFF Consortium, describe its approach to force field development and software, and discuss accomplishments to date as well as future plans. OpenFF releases both software and data under open and permissive licensing agreements to enable rapid application, validation, extension, and modification of its force fields and software tools. We discuss lessons learned to date in this new approach to force field development. We also highlight ways that other force field researchers can get involved, as well as some recent successes of outside researchers taking advantage of OpenFF tools and data.

Refined Cumulative Risk Assessment of Pb, Cd, and as in TCM Decoction Based on Bioavailability through In Vitro Digestion/MDCK Cells.

In this study, the oral bioavailability of Pb, Cd, and As in three types of traditional Chinese medicines (TCMs) and TCM decoctions were investigated through in vitro PBET digestion/MDKC cell model. Furthermore, a novel cumulative risk assessment model associated with co-exposure of heavy metal(loid)s in TCM and TCM decoction based on bioavailability was developed using hazard index (HI) for rapid screening and target organ toxicity dose modification of the HI (TTD) method for precise assessment. The results revealed that the bioavailability of Pb, Cd, and As in three types of TCM and TCM decoction was 5.32-72.49% and 4.98-51.97%, respectively. After rapid screening of the co-exposure health risks of heavy metal(loid)s by the HI method, cumulative risk assessment results acquired by TTD method based on total metal contents in TCMs indicated that potential health risks associated with the co-exposure of Pb, Cd, and As in Pheretima aspergillum (E. Perrier) and Oldenlandia diffusa (Willd.) Roxb were of concern. However, considering both the factors of decoction and bioavailability, TTD-adjusted HI outcomes for TCMs in this study were <1, indicating acceptable health risks. Collectively, our innovation on cumulative risk assessment of TCM and TCM decoction provides a novel strategy with the main purpose of improving population health.

Rapid sulfurization obscures carotenoid distributions in modern euxinic environments

Anoxygenic phototrophic bacteria (green and purple sulfur bacteria) thrive in anoxic environments where light penetrates a sulfide-containing (euxinic) water column. Genomic data and photosynthetic bacterial carotenoid pigments should provide complementary information on the spatio-temporal dynamics of anoxygenic phototrophs in modern euxinic environments. In turn, these contemporary depositional settings often serve as analogues for ancient counterparts. However, in some modern environments, DNA-informed patterns of phototrophic sulfur bacteria occurrence do not match distributions of their carotenoid inventories. One possible explanation for these seemingly incompatible observations is that the rapid sulfurization of carotenoids and incorporation into macromolecules via multiple carbon–sulfur bonds prevents or confounds their detection by conventional means. Here, to evaluate this conundrum, we revisit some representative contemporary euxinic environments where anoxygenic phototrophic bacteria have mostly been detected based on genomic analyses. Although free intact carotenoids are sporadically detected in surface sediments, their distributions do not reveal a complete picture. Exogenously sourced fossil carotenoids (e.g., paleorenieratane) is an additional complication. Carotenoid inventories obtained by desulfurization with Raney nickel, on the other hand, stand in stark contrast to those present as free lipids. In particular, sulfur-linked carotenoids present in euxinic lake sediments provide a more complete picture of compositions of anoxygenic sulfur bacterial communities and account for discrepancies reported in previous studies. We observe a closer alignment between genomic data and patterns of sulfurized carotenoids and, importantly, our results highlight how sulfurization serves as a pathway for the rapid modification of highly functionalised lipids and their sequestration into the macromolecular component of sediment extracts.

Solar Cell Enhancement from Supercritical CO2 Dye Surface Modification of Mesoporous TiO2 Photoanodes.

In recent years, in an effort to reach Net Zero Emissions, there has been growing interest by various academic and industry communities to develop chemicals and industrial processes that are circular, sustainable and green. We report the rapid, simple and effective surface modification of a porous metal oxide with organic dyes using supercritical carbon dioxide (scCO2). Titanium dioxide (TiO2) photoanodes were coated in very short times, under mild conditions and the excess dye recovered afterwards for reuse. The process obviates the need for conventional toxic solvents, the generation of unwanted waste streams, and more importantly, we see an unexpected device performance enhancement of 212 and 163 % for TerCOOTMS, 2 a and TerCN/COOTBDMS, 4 dyes, respectively, when compared to the conventional solvent deposition method.

Overriding Mendelian inheritance in Arabidopsis with a CRISPR toxin-antidote gene drive that impairs pollen germination.

Synthetic gene drives, inspired by natural selfish genetic elements and transmitted to progeny at super-Mendelian (>50%) frequencies, present transformative potential for disseminating traits that benefit humans throughout wild populations, even facing potential fitness costs. Here we constructed a gene drive system in plants called CRISPR-Assisted Inheritance utilizing NPG1 (CAIN), which uses a toxin-antidote mechanism in the male germline to override Mendelian inheritance. Specifically, a guide RNA-Cas9 cassette targets the essential No Pollen Germination 1 (NPG1) gene, serving as the toxin to block pollen germination. A recoded, CRISPR-resistant copy of NPG1 serves as the antidote, providing rescue only in pollen cells that carry the drive. To limit potential consequences of inadvertent release, we used self-pollinating Arabidopsis thaliana as a model. The drive demonstrated a robust 88-99% transmission rate over two successive generations, producing minimal resistance alleles that are unlikely to inhibit drive spread. Our study provides a strong basis for rapid genetic modification or suppression of outcrossing plant populations.

Adhesion Properties and Stability of Polar Polymers Treated by Air Atmospheric Pressure Plasma.

This study continues the discussion on the surface modification of polymers using an atmospheric pressure plasma (APP) reactor in air. These results complement prior research focusing on nonpolar polymers. Polymers, such as polyethylene terephthalate, polyetheretherketone, and polymethyl methacrylate, containing structurally bonded oxygen are studied, representing a range of properties such as oxygen content, crystalline/amorphous structure, polarity, functionality, and aliphatic/aromatic structure. APP induces superior wetting properties on the hydrophilic polymer surfaces with rapid and uniform modification within 0.5 s of exposure. The amorphous structures undergo additional modification for longer exposure. Moreover, the aliphatic chain structures require longer plasma exposure to reach surface modification equilibrium. The polar polymers reach a limit level of modification corresponding to a minimum water contact angle of about 50°. The surface polarity increases on average by a factor of approximately two. The equilibrium values of the adhesion work attained after post-processing recovery fall within a limited range of about 100-120 mJ/m2. The enhancement of surface functionality through the creation of oxidized groups primarily depends on the initial oxygen content and reaches a limit of about 40 at.% oxygen. The surface properties of the treated polar surfaces exhibit good stability, comparable to that of the previously tested nonpolar polymers.

Highly-Sensitive Polymer Optical Fiber SPR Sensor for Fast Immunoassay

A new type of human immunoglobulin G (IgG) sensors based on the surface plasmon resonance (SPR) in the low refractive index (RI) plastic optical fiber (POF) and an antibody immobilization method is presented. A 50-nm-thick gold film was formed on the polished D-shaped fiber surface by magnetron sputtering. The RI response of the POF sensor is 30 049.61 nm/RIU, which is 26.5 times higher than that of single mode fiber (SMF) SPR sensors. The proposed SPR biosensor can be developed by simple and rapid modification of the gold film with 11-mercapto undecanoic acid (MUA). Upon immobilization of the goat anti-human IgG antibody, the resonance wavelength shifts by 11.2 nm. The sensor can be used to specifically detect and quantify the human IgG at concentrations down to 245.4 ng/mL with the sensitivity of 1.327 7 nm per µg/mL, which offers an enhancement of 12.5-fold compared to that of the conventional SMF based SPR sensors. The proposed device may find the potential applications in the case of use at the point of care.

Development of a Candidate TMV Epitope Display Vaccine against SARS-CoV-2.

Essential in halting the COVID-19 pandemic caused by SARS-CoV-2, it is crucial to have stable, effective, and easy-to-manufacture vaccines. We developed a potential vaccine using a tobacco mosaic virus (TMV) epitope display model presenting peptides derived from the SARS-CoV-2 spike protein. The TMV-epitope fusions in laboratory tests demonstrated binding to the SARS-CoV-2 polyclonal antibodies. The fusion constructs maintained critical epitopes of the SARS-CoV-2 spike protein, and two in particular spanned regions of the receptor-binding domain that have mutated in the more recent SARS-CoV-2 variants. This would allow for the rapid modification of vaccines in response to changes in circulating variants. The TMV-peptide fusion constructs also remained stable for over 28 days when stored at temperatures between -20 and 37 °C, an ideal property when targeting developing countries. Immunogenicity studies conducted on BALB/c mice elicited robust antibody responses against SARS-CoV-2. A strong IFNγ response was also observed in immunized mice. Three of the six TMV-peptide fusion constructs produced virus-neutralizing titers, as measured with a pseudovirus neutralization assay. These TMV-peptide fusion constructs can be combined to make a multivalent vaccine that could be adapted to meet changing virus variants. These findings demonstrate the development of a stable COVID-19 vaccine candidate by combining SARS-CoV-2 spike protein-derived peptides presented on the surface of a TMV nanoparticle.

The Impact of Inorganic Systems and Photoactive Metal Compounds on Cytochrome P450 Enzymes and Metabolism: From Induction to Inhibition.

While cytochrome P450 (CYP; P450) enzymes are commonly associated with the metabolism of organic xenobiotics and drugs or the biosynthesis of organic signaling molecules, they are also impacted by a variety of inorganic species. Metallic nanoparticles, clusters, ions, and complexes can alter CYP expression, modify enzyme interactions with reductase partners, and serve as direct inhibitors. This commonly overlooked topic is reviewed here, with an emphasis on understanding the structural and physiochemical basis for these interactions. Intriguingly, while both organometallic and coordination compounds can act as potent CYP inhibitors, there is little evidence for the metabolism of inorganic compounds by CYPs, suggesting a potential alternative approach to evading issues associated with rapid modification and elimination of medically useful compounds.

Streptococcus pyogenes Cas9 ribonucleoprotein delivery for efficient, rapid and marker-free gene editing in Trypanosoma and Leishmania.

Kinetoplastids are unicellular eukaryotic flagellated parasites found in a wide range of hosts within the animal and plant kingdoms. They are known to be responsible in humans for African sleeping sickness (Trypanosoma brucei), Chagas disease (Trypanosoma cruzi), and various forms of leishmaniasis (Leishmania spp.), as well as several animal diseases with important economic impact (African trypanosomes, including Trypanosoma congolense). Understanding the biology of these parasites necessarily implies the ability to manipulate their genomes. In this study, we demonstrate that transfection of a ribonucleoprotein complex, composed of recombinant Streptococcus pyogenes Cas9 (SpCas9) and an invitro-synthesized guide RNA, results in rapid and efficient genetic modifications of trypanosomatids, in marker-free conditions. This approach was successfully developed to inactivate, delete, and mutate candidate genes in various stages of the life cycle of T. brucei and T. congolense, and Leishmania promastigotes. The functionality of SpCas9 in these parasites now provides, to the research community working on these parasites, a rapid and efficient method of genome editing, without requiring plasmid construction and selection by antibiotics but requires only cloning and PCR screening of the clones. Importantly, this approach is adaptable to any wild-type parasite.

Ultrafast oscillation in a field emission-driven miniaturized gaseous diode

We report an ultrafast oscillation (up to ∼104 GHz) in the early stage of field emission-driven microdischarges. Spatiotemporal behaviors of electron density, space charge density, and electric field, exhibiting high-frequency oscillations, are demonstrated based on first-principle particle-in-cell/Monte Carlo collision simulations. Intermittent electron emission fluxes are identified from the electron phase space distributions whereas the ions are rather non-oscillatory in the transient timescale. The mechanisms of oscillation with growing amplitude are found to be related to the rapid modification of the field emission current affected by the space charge electric field, which is also accompanied by the fast response of the electron transport and ionization in a dynamic double-layer sheath. Further, a transport equation for emission current is solved to estimate the oscillation frequency, which agrees well with the simulation results. This study provides a more precise understanding of the formation of the field emission-driven microdischarge, which informs the design and optimization of miniaturized gaseous electronic devices.

MaPPeRTrac: A Massively Parallel, Portable, and Reproducible Tractography Pipeline.

Large-scale diffusion MRI tractography remains a significant challenge. Users must orchestrate a complex sequence of instructions that requires many software packages with complex dependencies and high computational costs. We developed MaPPeRTrac, an edge-centric tractography pipeline that simplifies and accelerates this process in a wide range of high-performance computing (HPC) environments. It fully automates either probabilistic or deterministic tractography, starting from a subject's magnetic resonance imaging (MRI) data, including structural and diffusion MRI images, to the edge density image (EDI) of their structural connectomes. Dependencies are containerized with Singularity (now called Apptainer) and decoupled from code to enable rapid prototyping and modification. Data derivatives are organized with the Brain Imaging Data Structure (BIDS) to ensure that they are findable, accessible, interoperable, and reusable following FAIR principles. The pipeline takes full advantage of HPC resources using the Parsl parallel programming framework, resulting in the creation of connectome datasets of unprecedented size. MaPPeRTrac is publicly available and tested on commercial and scientific hardware, so it can accelerate brain connectome research for a broader user community. MaPPeRTrac is available at: https://github.com/LLNL/mappertrac .

Enrichment of electrogenic microbes on surface-modified stainless steel 304L for rapid start-up of microbial electrochemical sensors

Stainless steel (SS) 304L, a cost-effective and mechanically robust material, is widely used in microbial electrochemical systems as an anode due to its versatility. However, poor biocompatibility and low corrosion resistance limit its potential. This study explores rapid SS surface modification techniques to enhance the sensitivity of microbial electrochemical sensors. Four coatings, namely electroreduction, carbon-coated, flame oxidised, and graphene-coated, were applied to SS electrodes. Surface morphology and characteristics were examined through FESEM-EDX and Raman profiling. The biosensor start-up and microbial enrichment demonstrated an exponential increase in current density, with carbon-based electrodes outperforming iron-based ones. The modified electrodes exhibited enhanced microbial-electrode interactions, evident in altered electrode potential. Starvation and recovery tests revealed distinct patterns, with carbon-coated electrodes showcasing rapid recovery. The air-in-chamber test indicated immediate loss and subsequent recovery of microbial activities upon water circulation. Surface modification significantly influenced the microbial response, with carbon-based coatings demonstrating superior performance. This study provides valuable insights into SS surface modification for improving microbial electrochemical sensor sensitivity, holding promise for diverse applications in environmental monitoring and biosensing.