Influence of Poly(Ethylene Glycol) Dimethacrylates' Chain Length on Electrical Conductivity and Other Selected Physicochemical Properties of Thermally Sensitive N-isopropylacrylamide Derivatives.

Thermosensitive polymers P1-P6 of N-isopropylacrylamide (PNIPA) and poly(ethylene glycol) dimethacrylates (PEGDMAs), av. Mn 550-20,000, were synthesized via surfactant-free precipitation polymerization (SFPP) using ammonium persulfate (APS) at 70 °C. The polymerization course was monitored by the conductivity. The hydrodynamic diameters (HDs) and the polydispersity indexes (PDIs) of the aqueous dispersion of P1-P6 in the 18-45 °C range, assessed via dynamic light scattering (DLS), were at 18° as follows (nm): 73.95 ± 19.51 (PDI 0.57 ± 0.08), 74.62 ± 0.76 (PDI 0.56 ± 0,01), 69.45 ± 1.47 (PDI 0.57 ± 0.03), 196.2 ± 2.50 (PDI 0.53 ± 0.04), 194.30 ± 3.36 (PDI 0.56 ± 0.04), 81.99 ± 0.53 (PDI 0.56 ± 0.01), 76.87 ± 0.30 (PDI 0.54 ± 0.01), respectively. The electrophoretic mobilities estimated the zeta potential (ZP) in the 18-45 °C range, and at 18 °C they were as follows (mV): -2.57 ± 0.10, -4.32 ± 0.67, -5.34 ± 0.95, --3.02 ± 0.76, -4.71 ± 2.69, -2.30 ± 0.36, -2.86 ± 0.42 for polymer dispersion P1-P6. The polymers were characterized by attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), H nuclear magnetic resonance (1H NMR), thermogravimetric analysis (TG/DTA), Differential Scanning Calorimetry (DSC), and powder X-ray diffraction analysis (PXRD). The length of the cross-linker chain influences the physicochemical properties of the obtained polymers.

Bubble-Free Frontal Polymerization of Acrylates via Redox-Initiated Free Radical Polymerization.

Thermal frontal polymerization (FP) of acrylate monomers mixed with conventional peroxide initiators leads to significant bubble formation at the polymerizing front, limiting their practical applications. Redox initiators present a promising alternative to peroxide initiators, as they prevent the formation of gaseous byproducts during initiator decomposition and lower the front temperature, thereby enabling bubble-free FP. In this study, we investigate the FP of acrylate monomers of varying functionalities, including methyl methacrylate (MMA), 1,6-hexanediol diacrylate (HDDA), and trimethylolpropane triacrylate (TMPTA), using N,N-dimethylaniline/benzoyl peroxide (DMA/BPO) redox couple at room temperature and compare their front behavior, pot life, and bubble formation with those of same resin systems mixed with a conventional peroxide initiator, Luperox 231. The use of redox couples in FP of acrylates shows promise for rapid, energy-efficient manufacturing of polyacrylates and can enable new applications such as 3D printing and composite manufacturing.

EXPRESS: Is the precedence of social re-orienting only inherent to the initiators?

Previous researches have revealed that initiators preferentially re-orient their attention towards responders with whom they have established joint attention. However, it remains unclear whether this precedence of social re-orienting is inherent to initiators or applies equally to responders, and whether this social re-orienting is modulated by the social contexts in which joint attention is achieved. To address these issues, the present study adopted a modified virtual-reality paradigm to manipulate social roles (initiator vs. responder), social behaviors (JA vs. Non-JA), and social contexts (intentional vs. incidental). Results indicated that people, whether as initiators or responders, exhibited a similar prioritization pattern of social re-orienting, and this was independent of the social contexts in which joint attention was achieved, revealing that the prioritization of social re-orienting is an inherent social attentional mechanism in humans. It should be noted, however, that the distinct social cognitive systems engaged when individuals switched roles between initiator and responder were only driven during intentional (Experiment 1) rather than incidental (Experiment 2) joint attention. These findings provide potential insights for understanding the shared-attention system and the integrated framework of attentional and mentalizing processes.

Perspective on Water-Soluble Two-Photon Initiator for Two-Photon Polymerization.

Two-photon polymerization (TPP) as an unparalleled technology empowers the rapid prototyping of customized three-dimensional (3D) micro/nanostructures, garnering noticeable interest in tissue engineering, drug delivery, and regenerative medicine. These applications have a high requirement on the biocompatibility and integrity of 3D structures. Therefore, it is important to develop two-photon initiator with good water-solubility, initiation efficiency, and biocompatibility. Here, we share our insights into the development of a water-soluble two-photon initiator (WTPI) and applications from the material and manufacturing perspective. We highlight the nonlinear optical properties and the synthesis of WTPI through three pathways. Then we further demonstrate the applications of the TPP technique in the aqueous phase in the fields of tissue engineering, 4D printing, and ceramic manufacturing. Finally, a general conclusion and outlook are provided for the future development and application of WTPI.

Approaching Angstrom-Scale Resolution in Lithography Using Low-Molecular-Mass Resists (<500 Da).

Resists that enable high-throughput and high-resolution patterning are essential in driving the semiconductor technology forward. The ultimate patterning performance of a resist in lithography is limited because of the trade-off between resolution, line-width roughness, and sensitivity; improving one or two of these parameters typically leads to a loss in the third. As the patterned feature sizes approach angstrom scale, the trade-off between these three metrics becomes increasingly hard to resolve and calls for a fundamental rethinking of the resist chemistry. Low-molecular-mass monodispersed metal-containing resists of high atom economy can provide not only very high resolution but also very low line-width roughness without sacrificing sensitivity. Here we describe a modular metal-containing resist platform (molecular mass <500 Da) where a molecular resist consists of just two components: a metal and a radical initiator bonded to it. This simple system not only is amenable to high-resolution electron beam lithography (EBL) and extreme ultraviolet lithography (EUVL) but also unites them mechanistically, giving a consolidated perspective of molecular and chemical processes happening during exposure. Irradiation of the resist leads to the production of secondary electrons that generate radicals in the initiator bonded to metal. This brings about an intramolecular rearrangement and causes solubility switch in the exposed resist. We demonstrate record 1.9-2.0 nm isolated patterns and 7 nm half-pitch dense line-space features over a large area using EBL. With EUVL, 12 nm half-pitch line-space features are shown at a dose of 68 mJ/cm2. In both of these patterning techniques, the line-width roughness was found to be ≤2 nm, a record low value for any resist platform, also leading to a low-performance trade-off metric, Z factor, of 0.6 × 10-8 mJ·nm3. With the ultimate resolution limited by instrumental factors, potential patterning at the level of a unit cell can be envisaged, making low-molecular-mass resists best poised for angstrom-scale lithography.

The Effect of the Initiator/Activator/Accelerator Ratio on the Degree of Conversion, Film Thickness, Flow, and Cytotoxicity of Dual-Cured Self-Adhesive Resin Cements.

Although self-adhesive resin cements are convenient and less technique-sensitive materials for dental clinicians, they exhibit a lower degree of conversion due to acidic components in their composition. Supplementation of the initiator, accelerator, and activator in self-adhesive resin cements has been suggested to compensate for the lower degree of conversion. This study aimed to evaluate the effects of different combinations of self-curing initiators, self-curing activators, and accelerators on the degree of conversion (DC) of self-adhesive resin cements. A dual-cured self-adhesive resin was prepared using six combinations of initiators, activators, and accelerators. The change in the DC over time was evaluated with and without light curing. The film thickness, flow properties, and cytotoxicity of each formulation were assessed. The results showed that all supplemental components had an effect on increasing the DC, but a greater increase in the DC was observed in the following order: activator, accelerator, and initiator. The cytotoxicity of the resin cements was related to the DC values, as resin cements with lower DC values exhibited higher cytotoxicity. The film thickness met the ISO standards for all groups. The results suggest that utilizing an activator is the most effective approach to enhance the DC in self-adhesive resin cement and that cytotoxicity tended to increase with lower DC values, whereas film thickness and flow properties demonstrated no correlation with DC values.

Synthesis and Physicochemical Properties of Thermally Sensitive Polymeric Derivatives of N-vinylcaprolactam.

Six derivatives of poly-N-vinylcaprolactam (PNVCL) P1-P6 were synthesized via surfactant-free precipitation polymerization (SFPP) at 70 °C, with potassium persulfate (KPS) as the initiator. P5 and P6 were synthesized using the cross-linker N,N'-Methylenebisacrylamide (MBA). The conductivity was measured to monitor the polymerization process. The hydrodynamic diameters (HDs) and polydispersity indexes (PDIs) of aqueous dispersions of P1-P6 were determined using dynamic light scattering (DLS) and zeta potential (ZP) using electrophoretic mobilities. At 18 °C for P1-P6, the HDs (nm) were 428.32 ± 81.30 and PDI 0.31 ± 0.19, 528.60 ± 84.70 (PDI 0.42 ± 0,04), 425.96 ± 115.42 (PDI 0.56 ± 0.08), 440.34 ± 106.40 (PDI 0.52 ± 0.09), 198.39 ± 225.35 (PDI 0.40 ± 0.19), and 1201.52 ± 1318.05 (PDI 0.71 ± 0.30), the and ZPs were (mV) 0.90 ± 3.23, -4.46 ± 1.22, -6.44 ± 1.82, 0.22 ± 0.48, 0.18 ± 0.79, and -0.02 ± 0.39 for P1-P6, respectively. The lower critical solution temperature ranged from 27 to 29 °C. The polymers were characterized using the ATR-FTIR method. The study concluded that the physicochemical properties of the product were significantly affected by the initial reaction parameters. Polymers P1-P4 and P6 have potential for use as drug carriers for skin applications.

Influence of the hydroperoxide structure on the reactivity and mechanical properties of self-cure dental composites.

OBJECTIVES: Hydroperoxides are key constituents of two-component dental materials. The objective of this study was to evaluate the influence of the hydroperoxide structure on the reactivity and on the mechanical properties of self-cure composites. METHODS: Hydroperoxides HP1-3 were synthesized by selective catalytic oxidation of the corresponding para-substituted cumene precursors and isolated in high purity. They were characterized by 1H NMR and 13C NMR spectroscopy. 16 self-cure composites, based on the redox initiator system hydroperoxide (Cumene hydroperoxide (CHP), HP1-3 or tert.-Amyl hydroperoxide (TAH))/polymerizable thiourea ATU1/copper(II) acetylacetonate, were formulated in Sulzer Mixpac two-component syringes. An equimolar hydroperoxide/ATU1 ratio was selected for each self-cure composite. The reactivity and the final double-bond conversions obtained with these two-component materials was assessed using RT-FTIR spectroscopy. The flexural strength and modulus were measured using a three-point bending setup, after storage of the specimens for 45 min at 37 °C (dry) and for 24 h in water at 37 °C. The working time of each self-cure composite was measured using an oscillating rheometer. RESULTS: CHP derivatives bearing an electron withdrawing group (HP2: ester or HP3: nitrile) in the para position were found to be more reactive than CHP, whereas the compound bearing an electron donating group (tert-butyl, HP1) was less reactive; molecular modelling data were reported for a better understanding of this structure/reactivity/efficiency relationship. All CHP derivatives were more reactive than the aliphatic hydroperoxide TAH. Excellent mechanical properties were obtained with self-cure composites containing either CHP or a para-functionalized CHP derivative. By carefully selecting the amounts of oxidizing/reducing agents and metal catalyst, suitable working times can be obtained with all evaluated hydroperoxides. HP3, thanks to its high reactivity, is nonetheless the most promising compound. SIGNIFICANCE: The curing rate of self-cure composites can be adapted by modifying the structure of the hydroperoxide. In agreement with molecular modelling data, the incorporation of CHP derivatives bearing an electron withdrawing group in the para position is particularly attractive. Indeed, due to a significant reactivity enhancement, the desired properties (working time, flexural strength/modulus) can be obtained by incorporating moderate amounts of hydroperoxide/acylthiourea as well as particularly low contents of metal catalyst to the two-component dental materials.

Fabrication of Tailored Membranes with Special Surface Wettability Features for Highly Efficient Crude Oil-in-Water Emulsion Separation.

Treating oily wastewater streams such as produced water has a huge potential to resolve the issue of wastewater disposal and generate useful water for reuse. Among different techniques employed for oily wastewater (oil-in-water; O/W emulsion) treatment, membrane-based separation is advantageous owing to its lower energy consumption, recycling, ease of operation, and wider scope of tuning the active layer chemistry for enhanced performance. In line with the possibilities of enhancing the performance of the membranes for efficient O/W emulsion separation, the current work is designed to yield five different variants of polyaniline (PANI) active layers with special surface wettability features (superhyrophilic and underwater superoleophobic) on a ceramic alumina support. To achieve variants of PANI on ceramic alumina supports, emulsion polymerization was carried out, and different concentrations of initiator ammonium persulfate (APS) were applied to lead to PANI-A@Aluminum Oxide membrane, PANI-B@Aluminum Oxide membrane, PANI-C@Aluminum Oxide membrane, PANI-D@Aluminum Oxide membrane, and PANI-E@Aluminum Oxide membrane corresponding to 0.15, 0.25, 0.35, 0.5, and 1.0 M concentrations of initiator. The variation in initiator concentration resulted in different PANI growth patterns; hence, the resultant membranes showed different structural, physical, and performance features. Different characterization techniques including 1H NMR, SEM, FE-TEM, AFM, water contact angle, XRD, EDX, and ATR-FTIR confirmed a more uniform and continuous growth of PANI (PANI-B) using a 0.25 M initiator concentration. The resultant PANI-B@Aluminum Oxide membrane showed an excellent surfactant stabilized crude O/W emulsion separation reaching >99% with a permeate flux of 2154 L m-2 h-1 (LMH) at 4 bar using a 100 ppm surfactant stabilized crude oil-in-water emulsion. The fouling and cleaning cycles revealed that the membrane can be reused with a 70% recovery of the initial permeate flux.

Lamotrigine-mediated rescue of RsgA-deficient Escherichia coli reveals another role of IF2 in ribosome biogenesis.

RsgA (small ribosomal subunit, 30S, GTPase), a late-stage biogenesis factor, releases RbfA from 30S-RbfA complex. Escherichia coli ΔrsgA (deleted for rsgA) shows a slow growth phenotype and an increased accumulation of 17S rRNA (precursor of 16S rRNA) and the ribosomal subunits. Here, we show that the rescue of the ΔrsgA strain by multicopy infB (IF2) is enhanced by simultaneous overexpression of initiator tRNA (i-tRNA), suggesting a role of initiation complex formation in growth rescue. The synergistic effect of IF2/i-tRNA is accompanied by increased processing of 17S rRNA (to 16S), and protection of the 16S rRNA 3'-minor domain. Importantly, we show that an IF2-binding anticonvulsant drug, lamotrigine (Ltg), also rescues the ΔrsgA strain growth. The rescue is accompanied by increased processing of 17S rRNA, protection of the 3'-minor domain of 16S rRNA, and increased 70S ribosomes in polysome profiles. However, Ltg becomes inhibitory to the ΔrsgA strain whose growth was already rescued by an L83R mutation in rbfA. Interestingly, like wild-type infB, overproduction of LtgRinfB alleles (having indel mutations in their domain II) also rescues the ΔrsgA strain (independent of Ltg). Our observations suggest the dual role of IF2 in rescuing the ΔrsgA strain. First, together with i-tRNA, IF2 facilitates the final steps of processing of 17S rRNA. Second, a conformer of IF2 functionally compensates for RsgA, albeit poorly, during 30S biogenesis. IMPORTANCE: RsgA is a late-stage ribosome biogenesis factor. Earlier, infB (IF2) was isolated as a multicopy suppressor of the Escherichia coli ΔrsgA strain. How IF2 rescued the strain growth remained unclear. This study reveals that (i) the multicopy infB-mediated growth rescue of E. coli ΔrsgA and the processing of 17S precursor to 16S rRNA in the strain are enhanced upon simultaneous overexpression of initiator tRNA and (ii) a conformer of IF2, whose occurrence increases when IF2 is overproduced or when E. coli ΔrsgA is treated with Ltg (an anticonvulsant drug that binds to domain II of IF2), compensates for the function of RsgA. Thus, this study reveals yet another role of IF2 in ribosome biogenesis.

Liquid metal nanoparticles as photo-initiators for preparation of transparent hydrogel with adjustable mechanical properties.

To achieve rapid preparation of hydrogels without using conventional chemical initiators, a stable suspension of eutectic gallium indium (EGaIn) liquid metal nanoparticles is explored by probe-sonicating the metal in an aqueous solution. Liquid metal suspension was sonicated to serve as a photo-initiator for acrylamide polymerization and produce hydrogels. The initiation effect comes from the fact that liquid metal suspension after sonication can produce a large number of free radicals when exposed to ultraviolet (UV) radiation, leading to initiation. The changes of liquid metal nanodroplets under UV light irradiation have been systematically investigated. Further, the liquid metal colloidal solutions were used to prepare hydrogels with the same transparency and adjustable mechanical properties as the samples initiated by commercial photo-initiators. This work shows the great application potential of liquid metal in the preparation of hydrogels and provides a new technical idea for the design of multifunctional hydrogels.

Design, Fabrication, and Characterization of a Planar Three-Electrode Trigger Switch Based on Flexible Printed Circuit Process.

An exploding foil initiator system (EFIs) is essential in modern weaponry for its safety and reliability. As the main component of EFIs, the performance of the switch is critical to EFIs. In this study, a planar three-electrode trigger switch was designed and fabricated using the Flexible Printed Circuits (FPC) process. Subsequently, the performance of the FPC switch was tested. The results show that the self-breakdown voltage of the FPC switch is stable. In addition, an FPF switch with a 0.6 mm main electrode gap demonstrated consistency, with delay times below 31.75 ns, and a jitter ranging from 1.7 ns to 10.94 ns at 900 V to 1200 V, evidencing the FPC switches' reliability and uniform performance across various voltages. Compared to the Micro-Electro-Mechanical Systems (MEMS) switches of similar dimensions, the FPC switches achieved a faster high-current attainment with less inductance, showing a 5% reduction in loop inductance. The repetitive testing results demonstrate that the FPC switch maintains consistent output performance, with stable peak currents, peak current time, and delay time over 50 action cycles, highlighting its repeatability. The FPC switch was assembled with an EFI chip and capacitor into an integrated system, which was subsequently able to successfully detonate HNS-IV at 1000 V/0.22 µF, proving the FPC switch's potential in low inductance applications.

A Micro Bridge-Wing-Thickened Low-Energy Exploding Foil Initiator Chip.

To enhance the energy efficiency of exploding foil initiator systems (EFIs) and mitigate energy loss due to ablation in the bridge-wing regions, a low-energy bridge-wing-thickened EFI chip was designed and fabricated. Computational analysis revealed that increasing the thickness of the bridge flanks significantly reduces ablation within the bridge region during the electrical explosion. The refinement of the design led to the adoption of a bridge flank thickness of 19 µm, with the bridge area dimensions specified as 0.25 mm × 0.25 mm × 4 µm. This bridge-wing-thickened EFI chip was produced by employing micro-electro-mechanical systems (MEMS) technology and underwent rigorous performance evaluations. The empirical results closely matched the computational predictions, thereby corroborating the precision of the proposed model in simulating the temperature distribution seen during the explosion process. Notably, this enhanced EFI design achieves a flyer velocity of 3800 m/s at a condition of 900 V/0.22 µF, signifying a significant advancement in EFI system efficiency and performance.

Ultrasound-Triggered Azo Free Radicals for Cervical Cancer Immunotherapy.

PD-1 blockade is a first-line treatment for recurrent/metastatic cervical cancer but benefits only a small number of patients due to low preexisting tumor immunogenicity. Using immunogenic cell death (ICD) inducers is a promising strategy for improving immunotherapy, but these compounds are limited by the hypoxic environment of solid tumors. To overcome this issue, the nanosensitizer AIBA@MSNs were designed based on sonodynamic therapy (SDT), which induces tumor cell death under hypoxic conditions through azo free radicals in a method of nonoxygen radicals. Mechanistically, the azo free radicals disrupt both the structure and function of tumor mitochondria by reversing the mitochondrial membrane potential and facilitating the collapse of electron transport chain complexes. More importantly, the AIBA@MSN-based SDT serves as an effective ICD inducer and improves the antitumor immune capacity. The combination of an AIBA@MSN-based SDT with a PD-1 blockade has the potential to improve response rates and provide protection against relapse. This study provides insights into the use of azo free radicals as a promising SDT strategy for cancer treatment and establishes a basic foundation for nonoxygen-dependent SDT-triggered immunotherapy in cervical cancer treatment.

Intrinsic apoptosis is evolutionarily divergent among metazoans.

Apoptosis is regulated cell death that depends on caspases. A specific initiator caspase is involved upstream of each apoptotic signaling pathway. Characterized in nematode, fly, and mammals, intrinsic apoptosis is considered to be ancestral, conserved among animals, and depends on shared initiators: caspase-9, Apaf-1 and Bcl-2. However, the biochemical role of mitochondria, the pivotal function of cytochrome c and the modality of caspase activation remain highly heterogeneous and hide profound molecular divergence among apoptotic pathways in animals. Uncovering the phylogenetic history of apoptotic actors, especially caspases, is crucial to shed light on the evolutionary history of intrinsic apoptosis. Here, we demonstrate with phylogenetic analyses that caspase-9, the fundamental key of intrinsic apoptosis, is deuterostome-specific, while caspase-2 is ancestral to bilaterians. Our analysis of Bcl-2 and Apaf-1 confirms heterogeneity in functional organization of apoptotic pathways in animals. Our results support emergence of distinct intrinsic apoptotic pathways during metazoan evolution.

Highly chromophoric fluorescent-labeled methionyl-initiator tRNAs applicable in living cells.

Fluorescent initiator tRNAs (tRNAi) play a crucial role in studying protein synthesis, yet generating highly fluorescent tRNAi complexes remains challenging. We present an optimized strategy to effectively generate highly fluorescent initiator-tRNA complexes in living cells. Our strategy allows the generation of Fluo-Met-tRNAiMet complexes. These complexes can have highly chromogenic N-terminal labeling. For generating such complexes, we use either purified fluorescent methionine (PFM) or non-purified fluorescently labeled methionine (NPFM). Furthermore, PFM promotes the active generation of endogenous tRNAi in cells, leading to highly efficient Fluo-Met-tRNAiMet complexes. Finally, PFM-tRNAiMet complexes also facilitate the visualization of native fluorescently labeled Tat binding to beads. This demonstrates the potential of our approach to advance precision protein engineering and biotechnology applications.

An Engineered Laccase from Fomitiporia mediterranea Accelerates Lignocellulose Degradation.

Laccases from white-rot fungi catalyze lignin depolymerization, a critical first step to upgrading lignin to valuable biodiesel fuels and chemicals. In this study, a wildtype laccase from the basidiomycete Fomitiporia mediterranea (Fom_lac) and a variant engineered to have a carbohydrate-binding module (Fom_CBM) were studied for their ability to catalyze cleavage of ß-O-4' ether and C-C bonds in phenolic and non-phenolic lignin dimers using a nanostructure-initiator mass spectrometry-based assay. Fom_lac and Fom_CBM catalyze ß-O-4' ether and C-C bond breaking, with higher activity under acidic conditions (pH < 6). The potential of Fom_lac and Fom_CBM to enhance saccharification yields from untreated and ionic liquid pretreated pine was also investigated. Adding Fom_CBM to mixtures of cellulases and hemicellulases improved sugar yields by 140% on untreated pine and 32% on cholinium lysinate pretreated pine when compared to the inclusion of Fom_lac to the same mixtures. Adding either Fom_lac or Fom_CBM to mixtures of cellulases and hemicellulases effectively accelerates enzymatic hydrolysis, demonstrating its potential applications for lignocellulose valorization. We postulate that additional increases in sugar yields for the Fom_CBM enzyme mixtures were due to Fom_CBM being brought more proximal to lignin through binding to either cellulose or lignin itself.

Multifunctional, Degradable Wearable Sensors Prepared with an Initiator and Crosslinker-Free Method.

The present zwitterionic hydrogel-based wearable sensor exhibits various limitations, such as limited degradation capacity, unavoidable toxicity resulting from initiators, and poor mechanical properties that cannot satisfy practical demands. Herein, we present an initiator and crosslinker-free approach to prepare polyethylene glycol (PEG)@poly[2-(methacryloyloxy)ethyl] dimethyl-(3-sulfopropyl) (PSBMA) interpenetrating polymer network (IPN) hydrogels that are self-polymerized via sunlight-induced and non-covalent crosslinking through electrostatic interaction and hydrogen bonding among polymer chains. The PEG@PSBMA IPN hydrogel possesses tissue-like softness, superior stretchability (∼2344.6% elongation), enhanced fracture strength (∼39.5 kPa), excellent biocompatibility, antibacterial property, reliable adhesion, and ionic conductivity. Furthermore, the sensor based on the IPN hydrogel demonstrates good sensitivity and cyclic stability, enabling effective real-time monitoring of human body activities. Moreover, it is worth noting that the excellent degradability in the saline solution within 8 h makes the prepared hydrogel-based wearable sensor free from the electronic device contamination. We believe that the proposed strategy for preparing physical zwitterionic hydrogels will pave the way for fabricating eco-friendly wearable devices.

Core promoterome of barley embryo.

Precise localization and dissection of gene promoters are key to understanding transcriptional gene regulation and to successful bioengineering applications. The core RNA polymerase II initiation machinery is highly conserved among eukaryotes, leading to a general expectation of equivalent underlying mechanisms. Still, less is known about promoters in the plant kingdom. In this study, we employed cap analysis of gene expression (CAGE) at three embryonic developmental stages in barley to accurately map, annotate, and quantify transcription initiation events. Unsupervised discovery of de novo sequence clusters grouped promoters based on characteristic initiator and position-specific core-promoter motifs. This grouping was complemented by the annotation of transcription factor binding site (TFBS) motifs. Integration with genome-wide epigenomic data sets and gene ontology (GO) enrichment analysis further delineated the chromatin environments and functional roles of genes associated with distinct promoter categories. The TATA-box presence governs all features explored, supporting the general model of two separate genomic regulatory environments. We describe the extent and implications of alternative transcription initiation events, including those that are specific to developmental stages, which can affect the protein sequence or the presence of regions that regulate translation. The generated promoterome dataset provides a valuable genomic resource for enhancing the functional annotation of the barley genome. It also offers insights into the transcriptional regulation of individual genes and presents opportunities for the informed manipulation of promoter architecture, with the aim of enhancing traits of agronomic importance.

Grafting Starch with Acrylic Acid and Fenton's Initiator: The Selectivity Challenge.

Through the graft polymerization of acrylic monomers onto starch, materials with interesting new properties can be synthesized. Fenton's chemistry, Fe2+/H2O2, is considered to be attractive for the initiation of graft polymerization with the monomer acrylic acid since it is cheap and reacts quickly at ambient conditions and should therefore be easy to scale up. However, the selectivity of the grafting versus the homopolymerization reaction poses a challenge with this monomer and this type of initiator. In the present review paper, we investigate why data from the literature on grafting systems with other monomers and initiation systems tend to show higher graft selectivity. A scheme is presented, based on reaction engineering principles, that supports an explanation for these observed differences. It is found that more selective activation of starch is a factor, but perhaps even more important is a low monomer-to-starch ratio at the starting sites of graft reactions. Since water is the most common solvent, monomers that are less water-soluble have an advantage in this respect. Based on the proposed scheme, methods to improve the graft selectivity with Fenton's initiator and acrylic acid are evaluated. Most promising appears to be a method of gradual monomer dosage. With gelatinized cassava starch in a batch reactor, both the grafting percentage (17 => 29%) and graft selectivity (18 => 31%) could be improved. This can be considered a principal breakthrough. Still, more research and development would be needed to refine the method and to implement the idea in a continuous reactor at a larger scale.