Insertion Strategy Research Articles

Asymmetric dearomative single-atom skeletal editing of indoles and pyrroles.

Heterocycle skeletal editing has recently emerged as a powerful tactic for achieving heterocycle-to-heterocycle transmutation without the need for multistep de novo heterocycle synthesis. However, the enantioselective skeletal editing of heteroarenes through single-atom logic remains challenging. Here we report the enantiodivergent dearomative skeletal editing of indoles and pyrroles via an asymmetric carbon-atom insertion, using trifluoromethyl N-triftosylhydrazones as carbene precursors. This strategy provides a straightforward methodology to access enantiomerically enriched six-membered N-heterocycles containing a trifluoromethylated quaternary stereocentre from planar N-heteroarenes. The synthetic utility of this enantiodivergent methodology was demonstrated by a broad evaluation of reaction scope, product derivatization and concise syntheses of drug analogues. Mechanistic studies reveal that the excellent asymmetric induction arises from the initial cyclopropanation step. The asymmetric single-atom insertion strategy is expected to have a broad impact on the field of single-atom skeletal editing and catalytic asymmetric dearomatization of aromatic compounds.

Features of membrane protein sequence direct post-translational insertion

The proper folding of multispanning membrane proteins (MPs) hinges on the accurate insertion of their transmembrane helices (TMs) into the membrane. Predominantly, TMs are inserted during protein translation, via a conserved mechanism centered around the Sec translocon. Our study reveals that the C-terminal TMs (cTMs) of numerous MPs across various organisms bypass this cotranslational route, necessitating an alternative posttranslational insertion strategy. We demonstrate that evolution has refined the hydrophilicity and length of the C-terminal tails of these proteins to optimize cTM insertion. Alterations in the C-tail sequence disrupt cTM insertion in both E. coli and human, leading to protein defects, loss of function, and genetic diseases. In E. coli, we identify YidC, a member of the widespread Oxa1 family, as the insertase facilitating cTMs insertion, with C-tail mutations disrupting the productive interaction of cTMs with YidC. Thus, MP sequences are fine-tuned for effective collaboration with the cellular biogenesis machinery, ensuring proper membrane protein folding.

The multi-depot pickup and delivery vehicle routing problem with time windows and dynamic demands

The rapid development of the urban logistics recycling industry, combined with the complexity of the pickup and delivery networks, has created a surge in dynamic customer demands and exacerbated the difficulty of logistics resource sharing. Accordingly, this work focuses on a multi-depot pickup and delivery vehicle routing problem with time windows and dynamic demands, which incorporates resource sharing. A bi-objective mathematical model is formulated to minimize the total operating cost and number of vehicles. A three-dimensional affinity propagation clustering and an adaptive nondominated sorting genetic algorithm-II are combined to find Pareto optimal solutions. A dynamic demand insertion strategy is proposed to determine the vehicle service sequences for dynamic situations. Combined with an elite iteration mechanism to prevent the proposed algorithm from falling into search stagnation and improve the convergence performance. The superiority of the proposed algorithm is verified by comparing with CPLEX solver (i.e., ILOG CPLEX Optimization Studio 12.10), multi-objective ant colony optimization, multi-objective particle swarm optimization, multi-objective evolutionary algorithm, multi-objective genetic algorithm, and decomposition-based multi-objective evolutionary algorithm with tabu search. Besides, the proposed model and algorithm are tested by a real-world case study in Chongqing city, China, and the further analysis indicates that significant improvement can be achieved. Furthermore, by incorporating the recognition and prediction techniques of artificial intelligence on dynamic demand data, the proposed approach can realize the self-optimization of multi-depot vehicle routes and the precise allocation of logistics resources in dynamic environments. This study is conducive to the construction of a digitally-intelligent urban logistics system.

Engineering Interlayer Space and Composite of Square-Shaped V2O5 by PVP-Assisted Polyaniline Intercalation and Graphene for Aqueous Zinc-Ion Batteries.

V2O5 undergoes irreversible phase transition and collapse of layered structure during the Zn2+ insertion/extraction, which severely limits its application as a cathode for aqueous zinc-ion batteries (AZIBs). Herein, a synergistic strategy of conductive polyaniline insertion and graphene composite was proposed to boost the Zn2+ storage performance of the V2O5 cathode. A square-shaped polyaniline (PANI)-intercalated and graphene-composited vanadium oxide (GO/PANI-PVP/V2O5) structure was successfully synthesized via an in situ oxidation/insertion polymerization combined with a hydrothermal method. The results showed that PANI intercalation and the composite of graphene combined with layered V2O5, enabling reversible intercalation of Zn2+/H+. The insertion of conjugated PANI not only increases the lattice spacing of V2O5, providing a channel for rapid transport of Zn2+, but also increases the storage sites for charges through doping/dedoping processes and redox conversion reactions. GO/PANI-PVP/V2O5 delivers an excellent specific capacity (495 mA h g-1 at 0.1 A g-1), wonderful rate capability (208 mA h g-1 at 30 A g-1), and good cycling stability (93% after 4000 cycles). Our results provide a new approach for adjusting the valence states, interlayer spacing, and rational design of organic-inorganic compound materials for different functional materials.

Regulating V2O5 Layer Spacing by a Polyaniline Molecule Chain to Improve Electrochemical Performance in Salinity Gradient Energy Conversion.

Salinity gradient energy is a chemical potential energy between two solutions with different ionic concentrations, which is also an ocean energy at the junction of rivers and seas. In our original work, the device "activated carbon//(0.083 M Na2SO4, 0.5 M Na2SO4)//vanadium pentoxide" for the conversion of salinity gradient energy was designed, and the conversion value of 6.29 J g-1 was obtained. However, the low specific surface area of the original V2O5 inevitably resulted in limited active sites and slow ionic transport rates, and the inherent lower conductivity and narrower layer spacing of the original V2O5 also resulted in poor electrode kinetic performance and cycle stability, hindering its practical application. To solve the above problems, the present work provides a strategy of using polyaniline (PANI) molecule chain intercalation to regulate the layer spacing of the original V2O5, and through the expansion and traction of the layer spacing, the composite PANI/V2O5 (PVO) with high specific surface area is prepared and used as an anode material for electrochemical conversion of salinity gradient energy application. The significantly increased layer spacing of the crystal plane (001) corresponding to the original V2O5 was confirmed with the PANI by the hydrogen bonding and the van der Waals force. The high specific surface area of the composite provides more electrochemical active sites to realize a fast Na+ migration rate and high specific capacitance. Meanwhile, the inserted PANI molecule chain, which acts not only as a pillar enlarging the Na+ diffusion channel but also as an anchor locking the gap between V2O5 bilayers, improves the structural stability of the V2O5 electrode during the electrochemical conversion process. The proposed insertion strategy for the conductive polymer PANI has created a new way to improve the cycle stability performance of the salinity gradient energy conversion device.

Recent progress in sulfonyl fluoride synthesis via the radical sulfur dioxide insertion and fluorination strategy

Recent progress in sulfonyl fluoride synthesis via the radical sulfur dioxide insertion and fluorination strategy

Photosensitizer-Free Photoinduced Ground-State Triplet Carbene-Assisted Persistent Aryloxy Radical Generation via Hydrogen Atom Transfer.

The traditional intermolecular O-H insertion strategy is typically associated with the reactivity exhibited by the singlet spin state, or it can alter the spin state from triplet to singlet by hydrogen bonding. Herein, we report diazoarylidene succinimide that generates a persistent ground-state triplet carbene under visible light (Blue LED, 456 nm) without a photosensitizer. This triplet carbene undergoes an intramolecular O-H insertion via hydrogen atom transfer, forming a persistent aryloxy radical without altering its spin state and leading to biologically relevant 2H-chromenes.

Reversible Vitrimisation of Single‐Use Plastics and their Mixtures

AbstractVitrimers are promising next‐generation materials, often exhibiting superior properties such as mechanical strength and solvent resistance compared to their thermoplastic counterparts, while still featuring recyclability due to their dynamic covalent crosslinks. The most common strategy to recycle vitrimers is via mechanical reprocessing at high temperatures, while others utilize chemical degradation to reobtain the constituent monomers. This work presents a new approach toward reprocessing by selectively breaking of the vitrimer's crosslinks, turning it back into a thermoplastic. This allows for reprocessing to be achieved in a more sustainable manner such as at lower temperatures and shorter times. After the desired shape has been obtained, facile re‐crosslinking turns the material into a vitrimer, with full restoration of thermal stability, mechanical properties, and gel fraction. To achieve this, a carbene C─H insertion strategy is utilized to introduce an imine‐based crosslinker into various thermoplastics and plastic mixtures to convert them into vitrimers. Properties typical of vitrimers such as a retained polymer network at high temperatures, and an Arrhenius‐type relationship between stress relaxation rate and temperature are observed, while its mechanical properties such as elongation at break and tensile toughness, particularly for plastic mixtures are significantly enhanced, first by crosslinking, then further enhanced up to 8 folds by the reversible crosslinking process.

Pain control during intrauterine device insertion: Transcutaneous electrical nerve stimulation.

Current practice lacks effective periprocedural pain management during common gynecological procedures such as intrauterine device insertion, increasing the possibility of significant pain and adverse reaction to such procedures. Because of this, pain can often be a barrier for a patient in choosing a form of contraception that best serves them. Transcutaneous electrical nerve stimulation offers an option for effective pain control during intrauterine device insertion. This case review characterizes five cases where patients were offered transcutaneous electrical nerve stimulation for pain control during intrauterine device insertion. The patients reported a range of no pain to moderate pain during intrauterine device insertion and rated their pain experience as better compared with prior insertions. Although limited to a case review, our findings suggest a promising clinical indication for transcutaneous electrical nerve stimulation as a pain management strategy for intrauterine device insertion.

Ligand‐Insertion Strategy for Constructing 2D Conjugated Metal‐Organic Framework with Large Pore Size for Electrochemical Analytics

Two‐dimensional conjugated metal‐organic frameworks (2D c‐MOFs) have shown great promise in various electrochemical applications due to their intrinsic electrical conductivity. A large pore aperture is a favorable feature of this type of material because it facilitates the mass transport of chemical species and electrolytes. In this work, we propose a ligand insertion strategy in which a linear ligand is inserted into the linkage between multitopic ligands, extending the metal ion into a linear unit of ‐M‐ligand‐M‐, for the construction of 2D c‐MOFs with large pore apertures, utilizing only small ligands. As a proof‐of‐concept trial of this strategy, a 2D c‐MOF with mesopores of 3.2 nm was synthesized using commercially available ligands hexahydrotriphenylene and 2,5‐dihydroxybenzoquinone. The facilitation of the diffusion of redox species by the large pore size of this MOF was demonstrated through a series of probes. With this feature, it showed superior performance in the electrochemical analysis of a variety of biological species.

Ligand-Insertion Strategy for Constructing 2D Conjugated Metal-Organic Framework with Large Pore Size for Electrochemical Analytics.

Two-dimensional conjugated metal-organic frameworks (2D c-MOFs) have shown great promise in various electrochemical applications due to their intrinsic electrical conductivity. A large pore aperture is a favorable feature of this type of material because it facilitates the mass transport of chemical species and electrolytes. In this work, we propose a ligand insertion strategy in which a linear ligand is inserted into the linkage between multitopic ligands, extending the metal ion into a linear unit of -M-ligand-M-, for the construction of 2D c-MOFs with large pore apertures, utilizing only small ligands. As a proof-of-concept trial of this strategy, a 2D c-MOF with mesopores of 3.2 nm was synthesized using commercially available ligands hexahydrotriphenylene and 2,5-dihydroxybenzoquinone. The facilitation of the diffusion of redox species by the large pore size of this MOF was demonstrated through a series of probes. With this feature, it showed superior performance in the electrochemical analysis of a variety of biological species.

Enhancement of the degradation capacity of IsPETase by acidic amino acids insertion and carbohydrate-binding module fusion.

The biocatalytic degradation of poly(ethylene terephthalate) (PET) through enzymatic methods has garnered considerable attention due to its environmentally friendly and non-polluting nature, as well as its high specificity. While previous efforts in enhancing IsPETase performance have focused on amino acid substitutions in protein engineering, we introduced an amino acid insertion strategy in this work. By inserting a negatively charged acidic amino acid, Glu, at the right-angle bend of IsPETase, the binding capability between the enzyme's active pocket and PET was improved. The resulted mutant IsPETase9394insE exhibited enhanced hydrolytic activity towards PET at various temperatures ranging from 30 to 45 ℃ compared with the wild-type IsPETase. Notably, a 10.04-fold increase was observed at 45 ℃. To further enhance PET hydrolysis, different carbohydrate-binding modules (CBMs) were incorporated at the C-terminus of IsPETase9394insE. Among these, the fusion of CBM from Verrucosispora sioxanthis exhibited the highest enhancement, resulting in a 1.82-fold increase in PET hydrolytic activity at 37 ℃ compared with the IsPETase9394insE. Finally, the engineered variant was successfully employed for the degradation of polyester filter cloth, demonstrating its promising hydrolytic capacity. In conclusion, this research presents an alternative enzyme engineering strategy for modifying PETases and enriches the pool of potential candidates for industrial PET degradation.

The DTR Technique-Drilling through the Roots of Posterior Teeth for Anatomically Guided Immediate Implant Placement: A Cohort Study.

The present study clinically analyzes implant survival of immediate implant placement cases using the drilling through roots (DTR) technique for anatomically-guided implant site preparation, as an aid to placing immediate dental implants in multi-radicular teeth. This clinical analysis utilized patients' electronic dental records who underwent immediate implant surgery using the DTR technique. All immediately placed implants were followed up regularly every year, after restoration. Implant survival was assessed with the Albrektsson et al. criteria. Inferential statistics was performed using SPSS v 21(IBM Corp., Armonk, NY) software. The Kaplan-Meier survival analysis was done to assess the implant survival probability. A total of 250 records of dental implants placed in 227 subjects using the DTR technique were considered. Results showed that the mean survival duration of implants was found 63.29 months and the median survival duration to be 55 months. A 100% success rate was seen in implant fixed bridge cases, and about 97.6% success was seen in single crown cases. No significant difference was seen in the survival rates during the follow-up period when compared according to the quadrants/site of implant placement. The findings concluded that tooth-guided rapid implant placement is a unique strategy for convenient and safe insertion, providing accurate three-dimensional positioning. The DTR method is a novel approach that facilitates accurate positioning and angulation of the implant bed preparation by stabilizing and guiding the osteotomy drills using the retained root. As a result, it enables optimal implant positioning at multirooted extraction sites. How to cite this article: Mahesh L, Miselli A, Bhasin MT, et al. The DTR Technique-Drilling through the Roots of Posterior Teeth for Anatomically Guided Immediate Implant Placement: A Cohort Study. J Contemp Dent Pract 2024;25(5):432-439.

Two gender systems in a bilingual mind: A study of gender assignment in code-switched Russian-Hebrew adjective-noun phrases

Russian and Hebrew bilingualism offers a unique opportunity to study gender assignment in code-switched adjective-noun phrases, as both languages mark grammatical gender. The present study investigated code-switched Russian-Hebrew adjective-noun phrases in order to trace gender assignment strategies: default, translation equivalent, shape-based, and insertion. For this purpose, 60 Russian-Hebrew bilingual speakers were recruited and divided into two groups: heritage language (HL) speakers of Russian dominant in Hebrew and immigrant (IMM) speakers dominant in Russian. Participants filled out a background questionnaire and completed an experimental task in which they were asked to listen to and rate the acceptability of sentences with embedded Hebrew code-switched nouns within Russian matrix sentences. The results demonstrated that most participants in the study exhibited a clear preference for two gender assignment strategies: shape-based and insertion. However, rating for opaque Hebrew nouns differed between the HL and IMM groups, pointing to the role of language proficiency in the gender assignment strategy preference: the HL group favored the insertion strategy, while the IMM group showed a preference for the shape-based strategy. The current study adds to the existing literature on gender assignment strategies in code-switched adjective-noun phrases and the mechanisms driving the choices of the speakers.

BCDA: A blockchain-based dynamic auditing scheme for intelligent IoT

Intelligent Internet of Things (IoT) provides services for machine learning applications by collecting real-time data, where data correctness crucially impacts the training accuracy of models. Data owners host incremental real-time data in the cloud and use blockchain as a public platform for data query, usage, and certification. Malicious attackers may manipulate data through methods like data poisoning, compromising model parameters. Blockchain-based data integrity verification (auditing) schemes can effectively detect and monitor such activities. However, managing the storage demands for massive on-chain data certificates poses significant challenges. Existing compressed certificate storage strategies, such as the Merkle-Hash tree (MHT), incur significant on-chain storage costs because the auxiliary paths and the entire tree structure must be uploaded during verification, resulting in an O(n) storage overhead. Polynomial commitments offer a promising alternative by reducing storage costs to hundreds of bytes. However, current polynomial commitment methods lack effective support for incremental data updates, which are essential for real-time applications. In this paper, we propose a novel polynomial commitment-based dynamic integrity verification scheme that implements cumulative commitment updates for the first time. Our scheme includes a new data block insertion and deletion strategy that maintains the original order of data blocks within polynomial commitments. Theoretical security analysis confirms the robustness of the proposed scheme, while simulation results demonstrate that it meets the efficiency requirements for blockchain-based distributed data integrity verification mechanisms.

Phase manipulating toward Ni catalysts via lattice nitrogen endows high energy density hydrogen gas battery

Metastable structures commonly generate unique catalytic effects. However, it is challenging to prepare due to thermodynamic limitations. Here, we first propose a nitrogen insertion strategy for Ni phase manipulating in alkaline hydrogen oxidation reaction (HOR). With the incremental lattice nitrogen, face centered cubic (fcc), bi-mixed fcc and N-induced an unconventional hexagonal close packed (N-u-hcp), tri-mixed fcc-Ni/N-u-hcp-Ni/Ni3N and Ni3N phase evolves successively, with corresponding volcanic HOR activities. Specifically, the biphasic fcc-Ni/N-u-hcp-Ni shows highest activity of 67 A g−1. Theoretical calculations show that lattice nitrogen reduce the formation energy of biphasic Ni, and this biphasic structure could provide electron rich interface to optimize the adsorption of H* and OH*. As a proof-of-concept for Ni-H2 battery, the gas diffusion electrode prepared with this biphasic Ni catalyst achieves an 8 Ah Ni-H2 battery with 163 Wh kg−1. This study provides an inspiration for the controllable synthesis of metastable nano-catalysts and demonstrates the efficient catalysis in practical hydrogen energy applications.

QM-DLA: an efficient qubit mapping method based on dynamic look-ahead strategy

Quantum computing has already demonstrated great computational potential across multiple domains and has received more and more attention. However, due to the connectivity limitations of Noisy Intermediate-Scale Quantum (NISQ) devices, most of the quantum algorithms cannot be directly executed without the help of inserting SWAP gates. Nevertheless, more SWAP gates lead to a longer execution time and, inevitably, lower fidelity of the algorithm. To this end, this paper proposes an optimized qubit mapping algorithm based on a dynamic look-ahead strategy to minimize the number of SWAP gates inserted. Firstly, a heuristic algorithm is proposed based on maximizing physical qubit connectivity to generate the optimal initial qubit mapping, which reduces the need for logical qubit shifts during subsequent SWAP gate insertion. Secondly, in the form of directed acyclic graphs, we identify quantum gates that violate the constraints of physical coupling and insert SWAP gates to remap qubits, thereby overcoming the limitations of qubit interactions. Finally, the optimal SWAP gate insertion strategy is built by comparing the cost of different SWAP gate insertion strategies through a multi-window look-ahead strategy to reduce the number of SWAP gates inserted. The experimental results show that the strategy in this paper decreases the number of SWAP gate insertions and significantly reduces the depth of quantum circuits when performing qubit mapping compared with state-of-the-art methods.

An effective multi-restart iterated greedy algorithm for multi-AGVs dispatching problem in the matrix manufacturing workshop

An excellent automated guided vehicle (AGV) scheduling scheme can effectively improve the productivity of automated manufacturing factories and reduce costs, so the AGV dispatching problem (AGVDP) has become a research hotspot. This paper studies AGVDP with AGV capacity and the latest delivery time to reduce the cost of the total objective consisting of AGV cost, travel cost, and penalty cost. To this end, a mixed-integer linear programming model and a multi-restart iterated greedy (MRIG) algorithm are proposed. According to the characteristics of the problem, an improved nearest neighbor-based heuristic algorithm (INNH) is proposed to generate an initial solution. INNH includes a balanced two-factor selection strategy and a multiple-try insertion strategy. In the MRIG, the destruction stage has been improved to have an adaptive parameter. To enhance the quality of the initial solution and the depth of the evolution, two improved reference local searches are proposed. Furthermore, a multi-restart strategy with a checking mechanism and five restart methods is designed to avoid MRIG falling into the local optimum. The results of sufficient statistical experiments show that the MRIG is obviously superior to the existing algorithms when solving AGVDP.

Hydrated Calcium Vanadate Nanoribbons with a Stable Structure and Fast Ion Diffusion as a Cathode for Quasi-Solid-State Zinc-Ion Batteries.

We demonstrated the use of hydrated calcium vanadate (CaV6O16·3H2O, denoted as CaVO-2) as a cathode for aqueous zinc-ion batteries (AZIBs). Nanoribbons of hydrated calcium vanadate facilitated shortening of the Zn2+ transport distance and accelerated zinc-ion insertion. The introduction of interlayer structure water increased the interlayer spacing of calcium vanadate and as a "lubricant". Ca2+ insertion also expanded the interlayer spacing and further stabilized the interlayer structure of vanadium-based oxide. The density functional theory results showed that the introduction of Ca2+ and structured water could effectively improve the diffusion kinetics, resulting in the rapid transport of zinc ions. As a result, AZIBs based on the CaVO-2 cathode offered high specific capacity (329.6 mAh g-1 at 200 mA g-1) and fast charge/discharge capability (147 mAh g-1 at 10 A g-1). Impressively, quasi-solid-state zinc-ion batteries based on the CaVO-2 cathode and polyacrylamide-cellulose nanofiber hydrogel electrolytes maintained an outstanding specific capacity and long cycle life (162 mAh g-1 over 10 000 cycles at 5 A g-1). This study provided a reliable strategy for metal-ion insertion and the structural water introduction of oxides to produce a high-quality cathode for ZIBs. Meanwhile, it provides ideas for the combination of vanadium-based materials and gel electrolytes to construct solid-state zinc-ion batteries.

Enhancing hydrogen evolution and oxidation kinetics through oxygen insertion into nickel lattice

Nickel-based materials, including metallic Ni and Ni oxide, have been widely studied in the exploration of non-precious-metal hydrogen electrocatalysts, but neither pure Ni nor NiO is ideal for the hydrogen evolution reaction (HER) and hydrogen oxidation reaction (HOR). In this paper, an oxygen insertion strategy was applied on nickel to regulate its hydrogen electrocatalytic performance, and the oxygen-inserted nickel catalyst was successfully obtained with the assistance of tungsten dioxide support (denoted as O-Ni/WO2). The partial insertion of oxygen in Ni maintains the face-centered cubic arrangement of Ni atoms, simultaneously expanding the lattice and increasing the lattice spacing. Consequently, the adsorption strength of *H and *OH on Ni is optimized, thus resulting in superior electrocatalytic performance of O-Ni/WO2 in alkaline HER/HOR. The Tafel slope of O-Ni/WO2@NF for HER is 56 mV dec−1, and the kinetic current density of O-Ni/WO2 for HOR reaches 4.85 mA cm−2, which is ahead of most currently reported catalysts. Our proposed strategy of inserting an appropriate amount of anions into the metal lattice could provide more possibilities for the design of high-performance catalysts.