This experiment is based on a 4-bit deoxyribonucleic acid （DNA） nanoswitch， in which specific DNA single strands trigger a "linear-to-circular" conformational transition. By leveraging the migration differences between the two conformations in gel electrophoresis， digital binary encoding is achieved. Different combinations of conformational switches can represent distinct information. Inspired by the "protection-deprotection" strategy in organic chemistry， an ribonucleic acid （RNA） protection strand is introduced to prevent the formation of the circular structure， thereby establishing an information encryption system. The system utilizes ribonuclease A （RNase A） for specific enzymatic cleavage to remove the protection， restoring information readout and establishing an RNA-regulated encryption system. By integrating DNA nanotechnology， binary encoding， and chemical protection strategies， agarose gel electrophoresis is applied throughout the entire experimental process， enabling full visualization from molecular construction to information read-write. This approach not only helps students master gel electrophoresis techniques and deepen their understanding of electrophoretic separation mechanisms and structure-activity relationships at the molecular level， but also exposes them to cutting‑edge fields such as molecular information encoding and DNA nanotechnology， effectively stimulating innovative thinking and interdisciplinary problem-solving skills.

Photocatalytic conversion of CO2, driven by solar energy, is regarded as a highly promising strategy to address the urgent energy crisis and environmental challenges. Consequently, the meticulous design and development of high-performance photocatalysts are of paramount strategic significance for promoting the efficient utilization and conversion of CO2 resources. To overcome the limitations of current photocatalysts, such as narrow light absorption range, high recombination rates of photogenerated charge carriers, and low catalytic activity in practical applications, this study employs an interfacial engineering strategy that couples optical and catalytic active centers. We designed and synthesized a CoTiO3/BiOBr p-n heterojunction composite material, with CoTiO3 derived from MOF and anchored on BiOBr nanosheets. This composite exhibits excellent light absorption capability and highly efficient photogenerated charge separation properties. Under simulated sunlight irradiation, without the addition of sacrificial agents or photosensitizers, the catalytic performance of the CoTiO3/BiOBr composite reached 14.07 mu mol center dot g- 1 center dot h- 1, which is 2.74 times higher than that of BiOBr. Various characterization analyses revealed that the p-n heterojunction formed between the MOF-derived CoTiO3 and BiOBr not only enhanced the light-harvesting capability of the material but also optimized the transport pathways of photogenerated charge carriers. This configuration efficiently suppressed electron-hole recombination, thereby substantially improving the photocatalytic CO2 reduction performance of BiOBr. Additionally, we further explored the electron transfer pathways involved in the photocatalytic reduction of CO2 in CoTiO3/BiOBr and proposed their possible mechanisms of action based on the experimental results. This study provides new approaches for designing efficient MOF-derived catalysts with high CO2 reduction activity.

The continued emergence of antigenic drift and drug-resistant viral strains highlights the need for antiviral strategies that deliver robust efficacy, broad subtype coverage, and minimal off-target toxicity. We demonstrate a potent and broad-spectrum strategy that employs hybrid biomaterials of Urumin (a host defense peptide) and a honeycomb (HC) DNA origami through spatially organized multivalent presentation for enhanced antiviral efficacy. Molecular dynamics simulations reveal that Urumin penetrates and destabilizes the hemagglutinin (HA) trimer core, disrupting influenza A viral (IAV) entry. Arranging Urumin in trimeric clusters on the HC enables potent multivalent binding to trimeric HAs on IAV, enhancing antiviral efficacy at nanomolar concentrations, similar to 1000-fold more effective than free Urumin. In vitro assays confirm HC-Urumin outperforms free Urumin in blocking viral entry and preserving cell viability in more IAV subtypes. In vivo studies show that compared to free Urumin, HC-Urumin treatment reduces disease severity, preserves physiological behavior, and decreases mortality in infected mice, while maintaining virus-specific adaptive immune responses without altering humoral immunity. Our study offers an advanced and effective materials platform and strategy for broad-spectrum, low-dose intervention against human and animal IAVs, which can be adapted to combat other viruses by patterning corresponding host defense peptides on custom designed DNA nanostructures.

The continued emergence of antigenic drift and drug-resistant viral strains highlights the need for antiviral strategies that deliver robust efficacy, broad subtype coverage, and minimal off-target toxicity. We demonstrate a potent and broad-spectrum strategy that employs hybrid biomaterials of Urumin (a host defense peptide) and a honeycomb (HC) DNA origami through spatially organized multivalent presentation for enhanced antiviral efficacy. Molecular dynamics simulations reveal that Urumin penetrates and destabilizes the hemagglutinin (HA) trimer core, disrupting influenza A viral (IAV) entry. Arranging Urumin in trimeric clusters on the HC enables potent multivalent binding to trimeric HAs on IAV, enhancing antiviral efficacy at nanomolar concentrations, ~1,000-fold more effective than free Urumin. In vitro assays confirm HC-Urumin outperforms free Urumin in blocking viral entry and preserving cell viability in more IAV subtypes. In vivo studies show that compared to free Urumin, HC-Urumin treatment reduces disease severity, preserves physiological behavior, and decreases mortality in infected mice, while maintaining virus-specific adaptive immune responses without altering humoral immunity. Our study offers an advanced and effective materials platform and strategy for broad-spectrum, low-dose intervention against human and animal IAVs, which can be adapted to combat other viruses by patterning corresponding host defense peptides on custom designed DNA nanostructures.

A comprehensive understanding of the interrelationships among various DNA dodecahedral topological configurations holds immense theoretical significance for guiding experimental synthesis and practical applications. In this study, we investigate the topological isomers of DNA dodecahedral links. We defined DNA dodecahedral links with a consistent component number and genus as topological isomers. Two distinct strategies were employed to identify potential topological isomers. The HOMFLY-polynomial has been validated as a potent tool for distinguishing the topological isomers of DNA dodecahedral links. Our research not only provides valuable insights into the comprehensive understanding of DNA nanostructures but also offers clues for scientists to screen and synthesize unexplored DNA nanostructures.

DNA has been utilized as a versatile nanomaterial for synthesizing various functional nanostructures. Various DNA nanostructures synthesized based on the principle of symmetry have demonstrated significant potential for applications. However, designing and synthesizing of these structures in a simple and efficient manner still pose challenges. To address these issues, we have developed a MATLAB algorithm based on binary operations to screen configurations with minimal DNA components. Furthermore, we have analyzed the conversion mechanisms between different configurations, providing theoretical guidance for targeted regulatory in chemistry. The results indicate that this concise algorithm allows us to identify all possible target configurations without laborious calculations, saving time and expanding the pool of potential candidates for DNA tetrahedra, cubes synthesis.

In this study, silver nanowires (AgNWs) with diameters of 25-40 nm were incorporated into lotus root starch gel (LRS) and lotus root starch-tannic acid gel (LRS/TA) via a coating process. The antibacterial performance of the resulting composites ( AgNWs coated LRS and AgNWs coated LRS/TA) were evaluated against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus via the inhibition zone and the spread plate count method. At equivalent bacterial concentrations, the inhibition zone tests revealed that the AgNWs coated LRS/TA (LRS/TA/AgNWs) gels exhibited a threefold higher antibacterial rate against both S. aureus and E. coli compared to the AgNWs coated LRS (LRS/AgNWs) gel. Results of the spread plate count exhibited that both LRS/AgNWs and LRS/TA/AgNWs achieved 99.99 % inhibition rates against E. coli. The LRS/TA/AgNWs composite displayed superior inhibitory efficacy toward S. aureus compared to LRS/AgNWs. Our findings demonstrated the synergistic integration of TA and AgNWs within the LRS matrix significantly enhanced the dual antibacterial activity, highlighting the potential of LRS/TA/AgNWs gels as advanced antimicrobial dressings.

The rapid evolution and antigenic diversity of influenza A viruses (IAVs) continue to challenge antiviral strategies, highlighting the need for broadly effective and modular therapeutic platforms. While single-domain nanobodies and DNA aptamer-based inhibitors have emerged as promising candidates, their efficacy is limited by monomeric binding to the hemagglutinin (HA) proteins populating the viral envelope. A programmable antiviral platform based on a honeycomb-shaped designer DNA nanostructure (HC-DDN) engineered to multivalently display HA-targeting ligands with nanometer precision is presented. Two constructs are synthesized, HC-Nanobody and HC-Aptamer, organized in trimeric clusters to match the native HA trimer geometry. Using murine-adapted H1N1 and H3N2 models, it is shown that both constructs outperform their free counterparts in viral neutralization and cytoprotection. HC-Nanobody construct achieves >99% inhibition of viral entry and improves cell viability by 35-45% at nanomolar concentrations. To assess translational relevance, the HC-Nanobody construct in a porcine IAV infection model is further evaluated, where it maintains high antiviral efficacy (>97% inhibition) and confers a 30-55% increase in cell viability relative to free nanobodies, confirming robust cross-species performance. Overall, this work demonstrates the power of geometry-matched multivalency to enhance viral neutralization and provides a rational blueprint for designing broad-spectrum antivirals against rapidly evolving respiratory pathogens.

Ammonia has a wide range of applications in industry, agriculture, and energy storage. However, the Haber-Bosch synthesis of ammonia used in industry requires a high-temperature and high-pressure catalytic environment. In this study, the catalyst Bi5O7I/g-C3N4 was prepared through a simple calcination method, leveraging the unique layered structure and suitable band gap of Bi5O7I. Plasma technology was employed to activate nitrogen, converting inert N2 into more reactive NOx- intermediates, significantly reducing the reaction energy requirements. The presence of oxygen vacancies in the catalyst was found to lower the valence band energy, narrow the band gap, and extend the light absorption range, while also serving as active sites for the catalytic process. Moreover, the heterojunction structure of Bi5O7I/g-C3N4 enhanced the separation of photogenerated electron-hole pairs, improving carrier transport and enabling the participation of high-reduction potential electrons in ammonia synthesis. As a result, the catalyst achieved an ammonia yield of 59.09 mmol h-1 gcat.-1 and a Faraday efficiency of 20.09% in 0.1 M KOH under ambient conditions. This work highlights the use of abundant air and water as feedstocks and demonstrates an efficient, low-cost approach to ammonia synthesis.

General Chemistry,a foundational course for engineering students in Sino-foreign cooperative education programs,incorporates classic international textbooks to enhance its teaching quality.This approach,however,encounters challenges such as the influence of foreign culture and a potential erosion of cultural self-confidence during the teaching process.To counter this,the course emphasizes ideological and political education to deepen students'appreciation and understanding of their own culture.This paper details how the ideological and political development of the General Chemistry course is grounded in the principle of culture confidence.It actively integrates Chinese ideological and political elements while thoughtfully combining them with international perspectives throughout the teaching process.This integration not only enriches the course's content,but also fosters an effective ideological and political education environment,leading to significant educational outcomes.

DNA has emerged as a versatile material for constructing functional nanostructures with specific topological arrangements, making it highly desirable for synthesizing of DNA nanostructures using minimal components. In this study, we propose a novel approach to fabricate polyhedra using the fewest possible components and investigate the roles played by different components. Our results reveal that even-sided polygon components are composed of subunits distributed contiguously or alternately, while odd-sided polygon components are composed of subunits distributed alternately, which play a crucial role in reducing the overall component number to the limitation. These findings indicate that the minimum number of components required to construct a DNA Archimedean polyhedron depends on the types of polygons involved. Additionally, our approach not only exhibits high selectivity but also offers novel insights into precise control over DNA polyhedra with specific functionalities.

The development of highly efficient photocatalysts is important for CO2 reduction. In this work, bismuth oxychloride (BiOCl) nanospheres with exposed (110) crystalline surfaces were prepared via the coprecipitation method. Oxygen vacancies (OVs) were generated on the nanosphere surface by adjusting the solution pH. The final product obtained is BiOCl with abundant oxygen vacancies (BiOCl-x). Interfacial OVs have importance in terms of narrow bandgap. WO3 nanotubes were introduced during the growth of BiOCl crystals, and closely contacted WO3 nanotube-loaded BiOCl nanomicrospheres were obtained (WO3/BiOCl-x). The WO3/BiOCl-x photocatalyst showcased a substantial increase in CO production, reaching 27.3 mu mol g-1, which indicates a 2.7fold improvement compared with that of pure BiOCl. The photocatalytic CO2 reduction efficiency of BiOCl improved by combining OVs with p-n heterojunctions, which modulated the energy band structure of BiOCl and increased its photogenerated carrier mobility. This work provides some motivation for exploiting the synergy between defect engineering and heterojunctions to increase the activity of bismuth-based photocatalysts.

A theoretical investigation was performed to disclose the transformation mechanism of 8-oxo-7,8-dihydroguanine radical cation (8-oxoG⋅+ ) to protonated 2-amino-5-hydroxy-7,9-dihydropurine-6,8-dione (5-OH-8-oxoG) in base pair. The energy profiles for three possible pathways of the events were mapped. It is shown that direct loss of H7 from base paired 8-oxoG⋅+ is the only energetically favorable pathway to generate neutral radical, 8-oxoG(-H7)⋅. Further oxidation of 8-oxoG(-H7)⋅ : C to 8-oxoG(-H7)+  : C is exothermic. However, the 8-oxoG(-H7)+  : C deprotonation from all possible active sites is infeasible, indicating the inaccessible second proton loss and the lack of essential intermediate 2-amino-7,9-dihydropurine-6,8-dione (8-oxoGOX ). This makes 8-oxoG(-H7)+ act as the precursor of hydration leading to the generation of protonated 5-HO-8-oxoG by stepwise fashion in base pair, which would initiate the step down guanidinohydantoin (Gh) pathway. These results clearly specify the structure-dependent transformation for 8-oxoG⋅+ and verify the emergence of protonated 5-HO-8-oxoG in base pair.

Recent times have experienced more than ever the impact of viral infections in humans. Viral infections are known to cause diseases not only in humans but also in plants and animals. Here, we have compiled the literature review of aptamers selected and used for detection and inhibition of viral infections in all three categories: humans, animals, and plants. This review gives an in-depth introduction to aptamers, different types of aptamer selection (SELEX) methodologies, the benefits of using aptamers over commonly used antibody-based strategies, and the structural and functional mechanism of aptasensors for viral detection and therapy. The review is organized based on the different characterization and read-out tools used to detect virus-aptasensor interactions with a detailed index of existing virus-targeting aptamers. Along with addressing recent developments, we also discuss a way forward with aptamers for DNA nanotechnology-based detection and treatment of viral diseases. Overall, this review will serve as a comprehensive resource for aptamer-based strategies in viral diagnostics and treatment.

Silyl enol ethers have attracted enormous attention as they could serve as a test bed for the development of novel frustrated Lewis pairs (FLPs) catalytic systems. However, the reaction mechanism of hydrogenation catalysed by metal-free FLPs for these compounds to the corresponding secondary alcohols remains elusive to a large extent in previous studies. We thus performed a thorough investigation on the reaction mechanism by density functional theory (DFT). To illustrate the reaction mechanism of FLPs-catalysed hydrogenation for silyl enol ethers, trimethyl((l-phenylvinypoxy)silane (Me-TMS) was chosen as the prototype substrate and toluene as the solvent, where the FLPs were generated by ethylbis(perfiuorophenyl)-borane (Et-B(C6F5)(2)) and tri-tert-butylphosphine (t-Bu3P). The M06-2X functional in connection with 6-31 +G(d) basis set was used to optimize the structures of related species including in the Gibbs free energy profiles, and the energies were obtained at M06-2X/6-311+ +G(d,p) level of theory, where the solvent effect was simulated with the integral equation formalism, polarized continuum mode (IEF-PCM) in both calculations. Our results suggest that the FLPs-catalysed hydrogenation of silyl enol ethers in toluene begins with the formation of B-P-FLPs followed by hydrogen activation, proton transfer and hydride transfer to complete the process. It is obvious from the Gibbs free energy profile that the proton transfer is rate-determining step, the formation of B-P-FLPs and proton transfer are endothennal and the hydride transfer is no barrier. This indicates that the amount of H-2 and prototype substrate have significant influence on the FLPs-catalysed hydrogenation of silyl enol ethers. A higher temperature (328.15 K) is disadvantageous to hydrogenation reaction catalysed by FLPs but the reaction could be accelerated under higher pressure (4040 kPa). The Gibbs free energy profile calculations for timethyl((1-phenylprop-1-en-1 -yl)oxy)silane (Et-TMS) and tert-butyldimethyl((1-phenylvinyl)oxy)silane (Me-TBS) reveal that substituent group may inhibit the hydride transfer as the absence of a suitable construction for R-H--transfer, where the hydride does not direct to the C+ of silyl enol ethers and the distance between C+ and hydride is longer. These results would be helpful to design another novel FLPs-catalysed hydrogenation reaction for silyl enol ethers.

DNA不仅仅是遗传物质的载体,还因其自身特殊的可编程性和寻址性被用来实现材料自下而上的自组装,是合成纳米材料的理想原材料之一,被称为DNA纳米技术.近年来.随着核酸设计软件的开发和合成技术的逐渐成熟,DNA纳米技术初步实现了从材料设计合成到应用开发的过渡,DNA纳米材料的研究取得了长足进步.文章从核酸设计软件、DNA纳米材料的合成方法及应用研究三个方面进行简单综述,以期帮助读者全面了解该领域的研究进展.

Genetic information and the blueprint of life are stored in the form of nucleic acids. The primary sequence of DNA, read from the canonical double helix, provides the code for RNA and protein synthesis. Yet these already-information-rich molecules have higher-order structures which play critical roles in transcription and translation. Uncovering the sequences, parameters, and conditions which govern the formation of these structural motifs has allowed researchers to study them and to utilize them in biotechnological and therapeutic applications in vitro and in vivo. This review covers both DNA and RNA structural motifs found naturally in biological systems including catalytic nucleic acids, non-coding RNA, aptamers, G-quadruplexes, i-motifs, and Holliday junctions. For each category, an overview of the structural characteristics, biological prevalence, and function will be discussed. The biotechnological and therapeutic applications of these structural motifs are highlighted. Future perspectives focus on the addition of proteins and unnatural modifications to enhance structural stability for greater applicability.

高中化学课程标准的变化,对大学普通化学的教学工作带来了新的挑战和机遇.要适应这样的变化趋势,就需要思考并解决好从高中化学到大学普通化学的教学衔接.文章从大学普通化学面临的问题出发,分别从教师、学生、教材和教学方式等方面思考并阐述如何实现从高中化学到大学普通化学的延续和提升.最后,对大学普通化学的教学提出了一些新的建议.

Scientists can change programmed DNA strands to adjust edge length and vertex junction to control the 3D structures with precision space signatures. The number of strands plays an important role in sequence design, synthesis and constitutive property. However, the majority of DNA branched polyhedra comprise a number of single strands. Therefore, it is crucial to make the number of strands to be calculated as less as possible. DNA polyhedral links are regarded as ideal templates of DNA polyhedra. In this research, we introduce odd-half turn edges and pseudo-surrounded vertexes to build DNA polyhedral links and reduce the strands number of them to one or two. Compare to the known strategies, our strategy is well established to generate the DNA polyhedral links of one/two DNA strands easier and faster. All Platonic, pyramid and prism polyhedral links may provide candidates for DNA polyhedra synthesis.

DNA has been considered an ideal raw material to build nanostructures. However, the majority of known DNA branched polyhedra are composed of multiple components. In this research, we propose a rational approach to design and analyze DNA Platonic branched polyhedra with two components according to the topological view. The results show that the fragments number and the strand configurations give a great impact on the minimal number of components. Insights from our research can provide practical benefits for the design and synthesis of DNA polyhedra or other highly complex polyhedral structures in labs.