Principles Of Modification Research Articles

Magnetic Activation: A Novel Approach to Enhance Hydrogen Evolution Activity of Co0.85Se@CNTs Heterostructured Catalyst.

The heterostructure strategy is currently an effective method for enhancing the catalytic activity of materials. However, the challenge that is how to further improve their catalytic performance, based on the principles of material modification is must addressed. Herein, a strategy is introduced for magnetically regulating the catalytic activity to further enhance the hydrogen evolution reaction (HER) activity for Co0.85Se@CNTs heterostructured catalyst. Building on heterostructure modulation, an external alternating magnetic field (AMF) is introduced to enhance the electronic localization at the active sites, which significantly boosts catalytic performance (71 to 43mV at 10mA cm-2). To elucidate the catalytic mechanism, especially under the influence of the AMF, in situ Raman spectroscopy is innovatively applied to monitor the HER process of Co0.85Se@CNTs, comparing conditions with and without the AMF. This study demonstrates that introducing the AMF does not induce a change in the true active site. Importantly, it shows that the Lorentz force generated by the AMF enhances HER activity by promoting water molecule adsorption and O─H bond cleavage, with the Stark tuning rate indicating increased water interaction and bond cleavage efficiency. Theoretical calculations further support that the AMF optimizes energy barriers for key reaction intermediates (steps of *H2O-TS and *H+*1/2H2).

About effectiveness of domestic drug liraglutide: results of clinical cases in pediatrics

Obesity is a global problem in pediatrics. Scientific interest in the study of this disease in childhood and adolescence is due to a number of factors: a steady increase in the number of patients in most countries of the world, unfavorable long-term consequences and complications, its progression into adulthood. These circumstances dictate the need for health professionals to search for new methods of treatment and prevention. The basis of treatment is a comprehensive approach, including normocaloric diet, increased physical activity, behavioral therapy and psychological support. However, these methods are often ineffective. In recent years, medications, particularly glucagon-like peptide-1 agonists (the drug liraglutide), have been approved for effective weight loss. However, there is some clinical stagnation on the part of the medical community regarding its prescription due to the lack of clear criteria determining the validity and increasing the effectiveness of treatment. On the basis of clinical observations, to propose criteria determining the possibility of prescribing a domestic analog of liraglutide (enligria) to improve the effectiveness of treatment of obesity in adolescent children. Four clinical cases demonstrated the high efficacy of liraglutide with respect to leveling cardiometabolic risks regardless of the degree of obesity and increasing adherence to lifestyle modification principles in patients with a metabolically “healthy” obesity phenotype. Also, its use was associated with facilitating the management of different types of eating disorders. Additional criteria determining the validity of liraglutide prescription in the therapy of obesity in adolescent children were proposed. It will contribute to a wider introduction of this drug into practical healthcare.

Increasing the Duration of On-Task Behavior in Children with Borderline Intellectual Functioning through Shaping Techniques

This study aims to investigate and apply behavior modification principles, specifically using shaping techniques, to increase the duration of on-task behavior in children with Borderline Intellectual Functioning (BIF). The techniques used include antecedent control, reinforcement through token economy, and providing prompts to the participant. This study uses a single-subject design conducted over a total of 22 intervention sessions. The participant in this study is an 8-year and 7-month-old boy with BIF. The results of the study indicate an increase in the average duration of on-task behavior from 19 minutes in the initial measurement (pre-test) to 64 minutes in the final measurement (post-test) and 54 minutes in the follow-up measurement. It can be concluded that behavior modification principles, specifically using shaping techniques, can help to improve on-task behavior duration in children with Borderline Intellectual Functioning.

Advanced Dielectric Materials for Triboelectric Nanogenerators: Principles, Methods, and Applications.

Triboelectric nanogenerator (TENG) manifests distinct advantages such as multiple structural selectivity, diverse selection of materials, environmental adaptability, low cost, and remarkable conversion efficiency, which becomes a promising technology for micro-nano energy harvesting and self-powered sensing. Tribo-dielectric materials are the fundamental and core components for high-performance TENGs. In particular, the charge generation, dissipation, storage, migration of the dielectrics, and dynamic equilibrium behaviors determine the overall performance. Herein, a comprehensive summary is presented to elucidate the dielectric charge transport mechanism and tribo-dielectric material modification principle toward high-performance TENGs. The contact electrification and charge transport mechanism of dielectric materials is started first, followed by introducing the basic principle and dielectric materials of TENGs. Subsequently, modification mechanisms and strategies for high-performance tribo-dielectric materials are highlighted regarding physical/chemical, surface/bulk, dielectric coupling, and structure optimization. Furthermore, representative applications of dielectric materials based TENGs as power sources, self-powered sensors are demonstrated. The existing challenges and promising potential opportunities for advanced tribo-dielectric materials are outlined, guiding the design, fabrication, and applications of tribo-dielectric materials.

Trauma-Focused Cognitive Behavioral Therapy (TF-CBT) in Victims of Sexual Violence Who Experience Trauma: A Systematic Review

Incidents of sexual violence are like an iceberg phenomenon and continue to increase every year. However, this increase is inversely proportional to the rehabilitative efforts provided for victims of sexual violence. The impact of sexual violence is trauma that makes the victim feel helpless. Trauma-Focused Cognitive Behavior Therapy (TF-CBT) is the therapy of choice to treat these impacts. This systematic review aims to determine the implementation and benefits of TF-CBT for trauma victims of sexual violence. The search used seven databases: Scopus, Sage Journals, ScienceDirect, ProQuest, PubMed, Clinical Key, and EBSCOhost. The research design used in the selected articles was three with RCTs, 5 with Quasy experiments, and 2 with cohorts. Selection is based on the criteria of article publication time in the last ten years, providing full text in English. The symptoms measured in trauma cases are PTSD, post-traumatic symptoms, mental problems such as depression, suicide attempts, and behavioral problems. The results showed that TF-CBT positively influenced all of these symptoms. Implementing TF-CBT also involves the role of parents and modifications with culturally sensitive principles. TF-CBT can reduce trauma symptoms. It is hoped that TF-CBT can be used in other trauma cases and apply modification principles that previous researchers have carried out by being culturally sensitive and involving the role of parents.

New Model and Finite Element Analysis of the Anti-Extrusion Strength of Backfill Drilling Pipelines

Currently, in some domestic and foreign mines, the backfill drilling pipeline experiences a rupture phenomenon even when the wear degree is low. This results in a delay in production due to the filling becoming ‘sick’. This paper presents, for the first time, the damage mechanism from a mechanical perspective and re-derives the anti-extrusion strength model of the backfill drilling pipeline. We investigate the influence of the law on the anti-extrusion strength of pipelines from the perspective of strata and cement rings. We then verify the theoretical and simulation results through engineering examples. The results demonstrate that the Mises stress criterion is a suitable modification principle for the anti-extrusion strength model of the backfill drilling pipeline. The anti-extrusion strength of the pipeline is related to the elastic modulus and Poisson’s ratio of the stratum, and the thickness of the cement ring. It is negatively affected by the depth of the stratum. For hard strata, a cement ring with a smaller elastic modulus is suitable, while for soft stratum, a cement ring with a larger elastic modulus is recommended. When the missing angle of the cement ring is less than 60°, the stress concentration factor increases up to 2.2. The stress unloading capacity of the cement ring ranges from 32.7% to 37.8%, and optimal performance of the cement ring is achieved when it has high strength and low rigidity. The backfill filling pipeline of a copper mine abroad was destroyed due to external extrusion force exceeding its anti-extrusion strength value. The modified pipeline anti-extrusion strength model is 18.2% higher than the pipeline API strength value. This finding can inform the design of the backfill filling pipeline for China’s kilometer-deep wells in the future.

Sequence- and Structure-Specific tRNA Dihydrouridylation by hDUS2.

The post-transcriptional reduction of uridine to dihydrouridine (D) by dihydrouridine synthase (DUS) enzymes is among the most ubiquitous transformations in RNA biology. D is found at multiple sites in tRNAs, and studies in yeast have proposed that each of the four eukaryotic DUS enzymes modifies a different site; however, the molecular basis for this exquisite selectivity is unknown, and human DUS enzymes have remained largely uncharacterized. Here we investigate the substrate specificity of human dihydrouridine synthase 2 (hDUS2) using mechanism-based cross-linking with 5-bromouridine (5-BrUrd)-modified oligonucleotide probes and in vitro dihydrouridylation assays. We find that hDUS2 exclusively modifies U20 across diverse tRNA substrates and identify a minimal GU sequence within the tRNA D loop that underlies selective substrate modification. Further, we use our mechanism-based platform to screen small molecule inhibitors of hDUS2, a potential anticancer target. Our work elucidates the principles of substrate modification by a conserved DUS and provides a general platform for studying RNA modifying enzymes with sequence-defined activity-based probes.

Indirect confirmation and theoretical application of plasma shock−cavitation principle of pulsed laser shock

The coupling strengthening principle of the double physical effect of plasma shock−cavitation was proposed, and the rationality of the cavitation effect in pulsed laser shock treatment under liquid−confined conditions needs to be confirmed urgently. The XRD testing method and 304 stainless steel, which is easy to obtain diffraction peaks, were selected to quantitatively detect and characterize the residual stress distribution in the action area of a single pulse laser beam. The test results and literature analysis show that the different process conditions of laser shock processing bring about different strength matching of the two stress effects of plasma shock and cavitation, and the main source of stress effect of femtosecond laser shock without coating is the cavitation effect. The actual effects of the laser pulse width and other process parameters such as the absorption layer and the constraint layer affect or determine the material modification principle of the pulsed laser surface treatment.

Fire‐retardant and high‐strength polymeric materials enabled by supramolecular aggregates

AbstractHigh‐performance polymers have proliferated in modern society across a variety of industries because of their low density, good chemical stability, and superior mechanical properties. However, while polymers are widely applied, frequent fire disasters induced by their intrinsic flammability have caused massive impacts on human beings, the economy, and the environment. Supramolecular chemistry has recently been intensively researched to provide fire retardancy for polymers via the physical barrier and char‐catalyzing effects of supramolecular aggregates. In parallel, the noncovalent interactions between supramolecular and polymer chains, such as hydrogen bonding, π–π interactions, metal–ligand coordination, and synergistic interactions, can endow the matrix with enhanced mechanical strength. This makes it possible to integrate physical–chemical properties and noncovalent interactions into one supramolecular aggregate‐based high‐performance polymeric system on demand. However, fulfilling these promises needs more research. Here, we provide an overview of the latest research advances of fire‐retardant and high‐strength polymer materials based on supramolecular structures and interactions of aggregates. This work reviews their conceptual design, characterization, modification principles, performances, applications, and mechanisms. Finally, development challenges and perspectives on future research are also discussed.

General notions regarding ex repairs

SR EN 60079 is a series of standards for the use of equipment in explosive atmosphere that covers a wide range of considerations for them, as well as the definition of various classifications of hazardous areas. An important section of the series specifically covers the repair, overhaul and modification of equipment. This is different from the maintenance of equipment, unless the repair and overhaul cannot be separated from the maintenance. SR EN 60079-19 edition 2020 establishes the general principles of repair, revision, and modification, which are common to all explosion-proof equipment, with additional clauses to provide instructions relevant to certain types of protection. Assuming that repairs and revisions are carried out using good engineering practices and details of the certificate, then the final equipment is considered to comply with the original standard and the manufacturer's specifications. Where these specific data are not available, the equipment can be simply described as having been repaired in accordance with SR EN 60079-19 and the relevant standards for which the equipment was designed.

Improved Electrical Properties of Organic Modified Thermoplastic Insulation Material for Direct Current Cable Application.

To achieve exceptional recyclable DC cable insulation material using thermoplastic polypropylene (PP), we have introduced the organic polar molecule styrene-maleic anhydride copolymer (SMA) into PP-based insulation materials following the principles of deep trap modification. PP, PP/SMA, PP/ethylene-octene copolymer (POE), and PP/POE/SMA insulating samples were prepared, and their meso-morphology, crystalline morphology, and molecular structure were comprehensively characterized. The results indicate that SMA can be uniformly dispersed in PP with minimal impact on the crystalline morphology of PP. The DC electrical properties of the materials were tested at temperatures of 30, 50, and 70 °C. The findings demonstrate that the introduction of SMA can improve the DC properties of the material in both PP and PP/POE. The thermal stimulated depolarization current results reveal that SMA can introduce deep traps into the material, thereby improving its DC properties, which is in agreement with the quantum chemical calculation results. Subsequently, a bipolar carrier transport model was employed for coaxial cables to simulate the space charge distribution in the insulation layer of the four sets of insulation samples as well as the actual cable in service. The results highlight that SMA can significantly suppress space charge in PP and PP/POE systems, and it exhibits excellent electric field distortion resistance. In summary, the results illustrate that SMA is expected to be used as an organic deep trap modifier in PP-based cable insulation materials.

Biochar modification methods and mechanisms for salt‐affected soil and saline‐alkali soil improvement: A review

AbstractThe continuous growth of the world's population has led to an increased demand for food. Biochar (BC) contains valuable functional groups and nutrients, which have been demonstrated to enhance soil properties and boost crop yield. Nonetheless, unmodified BC exhibits significant alkalinity and a large salt concentration; thus, its efficacy in improving saline‐alkali soil remains a matter of contention. Therefore, scholars aim to address the aforementioned limitations by adapting BC. In this paper, a summary is given of the methods used to modify BC and the effects of modified BC on salt‐affected soil and saline‐alkali soil properties, including pH, nutrients and microbial activity. The effects and principles of different modifiers and modification methods on BC's physicochemical properties (porosity and functional group content and type, etc.) were revealed. Furthermore, the principle of soil improvement by modified BC varies depending on the modification method. Although modified BC can effectively enhance salt‐affected soil, its excessive application and improper selection of modifiers can aggravate Na+ toxicity or introduce other pollutants into salt‐affected soil. Therefore, using modified BC with care is imperative according to the actual situation. In this review, we provide a detailed introduction to the methods and principles of BC modification for saline‐alkali soil. Furthermore, we identify the shortcomings and future research directions in this field. These insights are valuable when choosing proper BC modification methods for salt‐affected soil.

Locking the Conformation of a Paddlewheel Rhodium Complex: Design, Synthesis, and Applications in Catalytic Nitrene Transfers

AbstractThe exponential proliferation of conformers makes it impossible to examine the entire population in most systems. Controlling conformational ensembles is thus pivotal in many areas of chemistry. Rh2(esp)2, a dicarboxylate‐derived paddlewheel rhodium complex, is one of the most effective catalysts for nitrene chemistry. Its enormous success has led to preparing many analogous complexes. However, there has been little consideration for the conformational dynamics of the parent catalyst. Herein, we report a new ligand modification principle that prevents conformer interconversion. The resulting complex comprises two isolable conformers, whose structures have been determined by X‐ray diffraction. Combined experimental and computational data has revealed similarities and dissimilarities between the conformationally confined and parent complexes. Three model cases have demonstrated the utility of conformational fixation in the development of stereoselective catalysts for nitrene transfer reactions. The design principle described in this study can be combined with other established modification strategies, serving as a springboard for further advancement of the chemistry of paddlewheel metal complexes.

Locking the Conformation of a Paddlewheel Rhodium Complex: Design, Synthesis, and Applications in Catalytic Nitrene Transfers.

The exponential proliferation of conformers makes it impossible to examine the entire population in most systems. Controlling conformational ensembles is thus pivotal in many areas of chemistry. Rh2(esp)2, a dicarboxylate-derived paddlewheel rhodium complex, is one of the most effective catalysts for nitrene chemistry. Its enormous success has led to preparing many analogous complexes. However, there has been little consideration for the conformational dynamics of the parent catalyst. Herein, we report a new ligand modification principle that prevents conformer interconversion. The resulting complex comprises two isolable conformers, whose structures have been determined by X-ray diffraction. Combined experimental and computational data has revealed similarities and dissimilarities between the conformationally confined and parent complexes. Three model cases have demonstrated the utility of conformational fixation in the development of stereoselective catalysts for nitrene transfer reactions. The design principle described in this study can be combined with other established modification strategies, serving as a springboard for further advancement of the chemistry of paddlewheel metal complexes.

Extended Mode-Dependent Persistent Dwell-Time Switching With Multi-Stage Dependent Modification or Averaging for Discrete-Time Switched Systems

In this brief, extended mode-dependent persistent dwell-time (EMDPDT) switching with the slow-and fast-switching areas of the mode-dependent feature, where subsystems separately run for not less and less than the MDPDT, is presented for a class of discrete-time switched systems (DTSSs). The existing MDPDT is shown to be a special case of the proposed EMDPDT. Further, to loosen the dwell-time restriction on slow-switching areas in the original MDPDT regularity, two novel principles of multi-stage dependent modification (MSDM) and multi-stage dependent averaging (MSDA) are launched. By means of MSDM (or MSDA), stability criteria are supplied for DTSSs under the EMDPDT switching, where smaller MDPDT lower bounds can be achieved for non-first stages (or partially random stages) in divided units formed by multiple stages. Meanwhile, at the cost of computation consumption, MSDM allows a lower total dwell-time restriction than MSDA. Finally, the efficiency and flexibility of EMDPDT with MSDM/MSDA are illustrated by an inverter example, which indicates the predictable applicability of the presented switching for practical switched applications.

Investigation of the Physicochemical Interactions and Modification Effects of Polyurethane on Asphalt Binder

Polyurethane (PU) is a synthetic polymeric material with excellent mechanical properties and chemical designability. An in-depth understanding of the synergetic effect between polyurethane and asphalt binder is needed to produce durable PU-modified asphalt paving materials. This study focuses on the physicochemical changes, the states of in situ synthesized PU, and the modification effects of PU after PU prepolymers and chain extenders are added into asphalt binder. Investigation methods involve the Fourier transform infrared (FTIR) spectroscopy, partial Corbett separation, confocal fluorescence microscopy, particle size distribution test, rheological test, and theoretical calculation. It was found that the incorporation of PU has no obvious chemical influence on the asphalt binder and the main working principle of PU modification is its physical dispersion in asphalt binder. In situ synthesized PU is uniformly dispersed in asphalt binder and the size distribution of PU particles follows a log-normal distribution. As PU content exceeds 15%, the formed PU particles in asphalt binder are noticeably enlarged. Moreover, PU modification leads to significant improvements in asphalt binder properties, including high-temperature rutting resistance, elastic recovery, and deformation resistance. Rheological experiments and theoretical calculations under the framework of suspension rheology indicate that PU-modified asphalt binder can be reasonably modeled as a bimodal solid particle suspension, and the dynamic viscosity of PU-modified asphalt binder is predominantly determined by the dynamic viscosity of the maltenes and the volume fractions of PU and asphaltenes.

Structure, photoactivity, and antimicrobial properties of phloxine B / poly(caprolactone) nanocomposite thin films

Many applications of polymeric materials require chemical surface treatments. One possibility is the formation of a thin nanocomposite layer without changes in the polymer matrix. In this work, poly(caprolactone) was prepared with a thin nanocomposite layer composed of organoclay and photoactive dye, phloxine B (PhB). The principle of modification was the fusion of a thin layer of organoclay with a polymer matrix by the intercalation of polymer chains into the organoclay layer. The surface properties and composition of the thin layer of the nanocomposite were described using electron microscopy, measurements of water contact angles, X-ray diffraction, as well as X-ray photoelectron, UV–vis, and infrared spectroscopies. These methods revealed the effectiveness of polymer intercalation, confirmed the hydrophobic properties of the layer, the thickness of the composite at the level of several μm, the surface composition, and homogeneous distribution of PhB. The main outcomes were photoactive and antimicrobial properties of the films. The effects of various factors such as surfactant and dye concentrations and presence of polymer on photophysical properties were evaluated. PhB retained luminescence in all prepared materials to be highest at the lowest dye concentration and gradually decreased with increasing dye concentration. This trend was also confirmed by measurements of time-resolved fluorescence and quantum yields. In terms of antimicrobial activity, only the composite with the highest concentration of PhB exhibited a significant reduction in S. aureus biofilm growth. A more significant reduction was achieved using green light irradiation (about 3% of the growth in the control). The influence of other factors and potential applications will be the subjects of further studies.

Technology and principle of improving solubility of Dioscoreae Rhizoma formula granules based on powder modification

The powder modification technology was used to improve the powder properties and microstructure of Dioscoreae Rhizoma extract powder, thereby solving the problem of poor solubility of Dioscoreae Rhizoma formula granules. The influence of modifier dosage and grinding time on the solubility of Dioscoreae Rhizoma extract powder was investigated with the solubility as the evaluation index, and the optimal modification process was selected. The particle size, fluidity, specific surface area, and other powder properties of Dioscoreae Rhizoma extract powder before and after modification were compared. At the same time, the changes in the microstructure before and after modification was observed by scanning electron microscope, and the modification principle was explored by combining with multi-light scatterer. The results showed that after adding lactose for powder modification, the solubility of Dioscoreae Rhizoma extract powder was significantly improved. The volume of insoluble substance in the liquid of modified Dioscoreae Rhizoma extract powder obtained by the optimal modification process was reduced from 3.8 mL to 0 mL, and the particles obtained by dry granulation of the modified powder could be completely dissolved within 2 min after being exposed to water, without affecting the content of its indicator components adenosine and allantoin. After modification, the particle size of Dioscoreae Rhizoma extract powder decreased significantly, d_(0.9) decreased from(77.55±4.57) μm to(37.91±0.42) μm, the specific surface area and porosity increased, and the hydrophilicity improved. The main mechanism of improving the solubility of Dioscoreae Rhizoma formula granules was the destruction of the "coating membrane" structure on the surface of starch granules and the dispersion of water-soluble excipients. This study introduced powder modification technology to solve the solubility problem of Dioscoreae Rhizoma formula granules, which provided data support for the improvement of product quality and technical references for the improvement of solubility of other similar varieties.

Synthesis of structurally diverse derivatives of aconitine-type diterpenoid alkaloids and their anti-proliferative effects on canine breast cancer cells

As one of the most common malignancies in female dogs, no drugs have been developed specifically for the treatment of canine mammary carcinoma. In our previous study, a series of diterpenoid alkaloids derivatives were synthesized and exhibited good anti-proliferative activity in vitro against both normal and adriamycin-resistant human breast cancer cells lines. In this study, a series of structurally diverse aconitine-type alkaloids derivatives were also synthesized basing on the minimal modification principle, by modifying on A-ring, C-ring, D-ring, N-atom or salt formation on aconitine skeleton. Their anti-proliferative effects and mechanism on canine mammary cancer cells were investigated, exhibiting the importance of the substitution at A ring, the long chain ester at the C8, the hydroxyl group at the C13, the phenyl ring at the C14 and the N-ethyl group, while the methoxy group at the C1 and C16 showed little effect on the activity. The results of the proliferation, apoptosis and ultrastructure tests of the treated canine mammary carcinoma cells referred that the representative compound, aconitine linoleate (25) could block the cell cycle of canine mammary carcinoma cells in the G0/G1 phase, and exhibit the anti-proliferative effect by inducing apoptosis.

Materials and structural design for preferable Zn deposition behavior toward stable Zn anodes

AbstractBenefiting from the high capacity of Zn metal anodes and intrinsic safety of aqueous electrolytes, rechargeable Zn ion batteries (ZIBs) show promising application in the post‐lithium‐ion period, exhibiting good safety, low cost, and high energy density. However, its commercialization still faces problems with low Coulombic efficiency and unsatisfied cycling performance due to the poor Zn/Zn2+ reversibility that occurred on the Zn anode. To improve the stability of the Zn anode, optimizing the Zn deposition behavior is an efficient way, which can enhance the subsequent striping efficiency and limit the dendrite growth. The Zn deposition is a controlled kinetics‐diffusion joint process that is affected by various factors, such as the interaction between Zn2+ ions and Zn anodes, ion concentration gradient, and current distribution. In this review, from an electrochemical perspective, we first overview the factors affecting the Zn deposition behavior and summarize the modification principles. Subsequently, strategies proposed for interfacial modification and 3D structural design as well as the corresponding mechanisms are summarized. Finally, the existing challenges, perspectives on further development direction, and outlook for practical applications of ZIBs are proposed.