Transition-Metal-Free Hydrodefluoroamination of Trifluoromethyl Enones for the Synthesis of α-Fluoroenamides.

A three-component strategy was developed to enable hydrodefluoroamination of ß-trifluoromethyl enones by selectively activating two C(sp3)-F bonds in the trifluoromethyl group. The method involved a sequence of carbonyl reduction, hydrodefluorination, and defluoroamination under transition-metal-free conditions. Synthetically useful (E)-stereospecific α-fluoroenamides were obtained in good yields with diverse functional group tolerance, which could be easily transformed into valuable organofluorides and heterocycles. The carbonyl auxiliary exerts both electronic and steric impacts on the CF3-alkenes, allowing for controllable and selective defluorination.

Silver-Promoted Three-Component Synthesis of Perfluoroalkenyl Pyrroles through Partial Defluorinative Functionalization of Perfluoroalkyl Halides.

A silver-promoted three-component heterocyclization of alkynes, perfluoroalkyl halides, and 1,3-dinucleophiles was developed for the efficient synthesis of privileged (E)-perfluoroalkenyl pyrroles. The reaction proceeded through a rationally designed sequence of radical perfluoroalkylation and intramolecular defluorinative [3 + 2]-heterocyclization. The utility of perfluoroalkyl halide as a perfluoroalkenyl reagent, by selective and controllable functionalization of two inert C(sp3)-F bonds at vicinal carbon centers on the perfluoroalkyl chain, provides a new reaction mode for the synthesis of value-added organofluorides starting from the easily available and low-cost fluorinated feedstock.

Regulation of Autophagy Signaling Pathways by Ginseng Saponins: A Review.

Ginseng saponins ( ginsenosides), bioactive compounds derived from ginseng, are widely used natural products with potent therapeutic properties in the management of various ailments, particularly tumors, cardiovascular and cerebrovascular diseases, and immune system disorders. Autophagy, a highly regulated and multistep process involving the breakdown of impaired organelles and macromolecules by autophagolysosomes and autophagy-related genes (ATGs), has gained increasing attention as a potential target for ginsenoside-mediated disease treatment. This review aims to provide a comprehensive overview of recent research advances in the understanding of autophagy-related signaling pathways and the role of ginsenoside-mediated autophagy regulation. By delving into the intricate autophagy signaling pathways underpinning the pharmacological properties of ginsenosides, we highlight their therapeutic potential in addressing various conditions. Our findings serve as a comprehensive reference for further investigation into the medicinal properties of ginseng or ginseng-related products.

Research on Gas-Assisted Extrusion of Elastic Material Round-Tube for Flexible Robot Body.

The flexible robot is widely used in a variety of fields such as medical treatment, rescue and disaster relief, industry, and agriculture. Using elastic materials to prepare flexible robot body structures is the core of the study of flexible robots. Due to the small selection of materials, single preparation method, and long fabrication time, in this study, a new method of gas-assisted extrusion (GAE) of elastic material round-tube for flexible robot body was proposed, and the numerical simulation of GAE was carried out with nonsilicone elastic material round-tube under different viscosities. The results showed that with the change of viscosity, the velocity, pressure drop, and shear rate of melt in all directions change accordingly. When the viscosity is too small or too large, it is easy to bring negative effects on the GAE process of elastic materials. TPE and TPU were completely plasticized in the GAE, and the surface of the extruded elastic products was smooth and straight, with full gloss. Therefore, in the preparation of the flexible robot body, nonsilicone elastic materials and GAE forming methods can be considered.

[Status and perspective of soil fauna eco-geography in China]. / ä¸­å›½åœŸå£¤åŠ¨ç‰©ç”Ÿæ€åœ°ç†å­¦ç ”ç©¶çŽ°çŠ¶ä¸Žå±•æœ›.

As regulators of the surface land processes, soil fauna communities are the vital foundations for healthy terrestrial ecosystems. Soil fauna have been studied in China for more than 70 years. Great progresses have been achieved in exploring soil fauna species composition and geographical distribution patterns. Soil fauna eco-geography, as a bridge between soil fauna geographic patterns and ecosystem services, has a new development opportunity with the deep recognition of soil fauna ecological functions. Soil fauna eco-geography research could be partitioned into four dimensions including the spatio-temporal patterns of: 1) the apparent characteristics of soil fauna community, such as species composition, richness and abundance; 2) the intrinsic characteristics of soil fauna community, such as dietary and habits; 3) soil fauna-related biotic and abiotic interactions especially those indicating drivers of soil fauna community structure or shaping the roles of soil fauna in ecosystems; and 4) soil fauna-related or -regulated key ecological processes. Current studies focus solely on soil fauna themselves and their geographical distributions. To link soil fauna geography more closely with ecosystem services, we suggested that: 1) converting the pure biogeography studies to those of revealing the spatio-temporal patterns of the soil fauna-related or regulated key relationships and ecological processes;2) expanding the temporal and spatial scales in soil fauna geographical research;3) exploring the integrated analysis approach for soil fauna-related data with multi-scales, multi-factors, and multi-processes;and 4) establishing standard reference systems for soil fauna eco-geographical researches. Hence, the change patterns of ecological niche of soil fauna communities could be illustrated, and precision mani-pulations of soil fauna communities and their ecological functions would become implementable, which finally contributes to ecosystem health and human well-being.

Palladium-Catalyzed Esterification of Aryl Fluorosulfates with Aryl Formates.

An efficient palladium-catalyzed carbonylation of aryl fluorosulfates with aryl formates for the facile synthesis of esters was developed. The cross-coupling reactions proceeded effectively in the presence of a palladium catalyst, phosphine ligand, and triethylamine in DMF to produce the corresponding esters in moderate to good yields. Of note, functionalities or substituents, such as nitro, cyano, methoxycarbonyl, trifluoromethyl, methylsulfonyl, trifluoromethoxy, fluoro, chloro, bromo, methyl, methoxy, N,N-dimethyl, and [1,3]dioxolyl, were well-tolerated in the reactions, which could be kept for late-stage modification. The reactions employing readily available and relatively robust aryl fluorosulfates as coupling electrophiles could potentially serve as an attractive alternative to traditional cross-couplings with the use of aryl halides and pseudohalides as substrates.

Chromosome-level genome assembly of the bethylid ectoparasitoid wasp Sclerodermus sp. 'alternatusi'.

The Bethylidae are the most diverse of Hymenoptera chrysidoid families. As external parasitoids, the bethylids have been widely adopted as biocontrol agents to control insect pests worldwide. Thus far, the genomic information of the family Bethylidae has not been reported yet. In this study, we crystallized into a high-quality chromosome-level genome of ant-like bethylid wasps Sclerodermus sp. 'alternatusi' (Hymenoptera: Bethylidae) using PacBio sequencing as well as Hi-C technology. The assembled S. alternatusi genome was 162.30 Mb in size with a contig N50 size of 3.83 Mb and scaffold N50 size of 11.10 Mb. Totally, 92.85% assembled sequences anchored to 15 pseudo-chromosomes. A total of 10,204 protein-coding genes were annotated, and 23.01 Mb repetitive sequences occupying 14.17% of genome were pinpointed. The BUSCO results showed that 97.9% of the complete core Insecta genes were identified in the genome, while 97.1% in the gene sets. The high-quality genome of S. alternatusi will not only provide valuable genomic information, but also show insights into parasitoid wasp evolution and bio-control application in future studies.

Beyond Conventional Charge Density Wave for Strongly Enhanced 2D Superconductivity in 1H-TaS2 Superlattices.

Noncentrosymmetric transition metal dichalcogenide (TMD) monolayers offer a fertile platform for exploring unconventional Ising superconductivity (SC) and charge density waves (CDWs). However, the vulnerability of isolated monolayers to structural disorder and environmental oxidation often degrade their electronic coherence. Herein, an alternative approach is reported for fabricating stable and intrinsic monolayers of 1H-TaS2 sandwiched between SnS blocks in a (SnS)1.15TaS2 van der Waals (vdW) superlattice. The SnS block layers not only decouple individual 1H-TaS2 sublayers to endow them with monolayer-like electronic characteristics, but also protect the 1H-TaS2 layers from electronic degradation. The results reveal the characteristic 3 × 3 CDW order in 1H-TaS2 sublayers associated with electronic rearrangement in the low-lying sulfur p band, which uncovers a previously undiscovered CDW mechanism rather than the conventional Fermi surface-related framework. Additionally, the (SnS)1.15TaS2 superlattice exhibits a strongly enhanced Ising-like SC with a layer-independent Tc of ≈3.0 K, comparable to that of the isolated monolayer 1H-TaS2 sample, presumably attributed to their monolayer-like characteristics and retained Fermi states. These results provide new insights into the long-debated CDW order and enhanced SC of monolayer 1H-TaS2, establishing bulk vdW superlattices as promising platforms for investigating exotic collective quantum phases in the 2D limit.

Treatment outcomes amongst older people with HIV infection receiving antiretroviral therapy.

OBJECTIVES: There is conflicting data regarding the response of older people with HIV (PWH) to antiretroviral therapy (ART). The objective of this study was to evaluate the long-term immunological and virological responses, changes in regimen, and adverse drug reactions (ADRs) in older participants (50+ years) compared with younger (18-34 years) and middle-aged (35-49 years) PWH. METHODS: A retrospective review of medical records was conducted on 1622 participants who received ART in Yunnan Province, China, from 2010 to 2019. The study compared CD4+ T-cell counts, CD4+/CD8+ ratio, and relative numbers between different groups using the Kruskal-Wallis test. Cox proportional hazards regression models were used to identify variables associated with the occurrence of immune reconstitution insufficiency. The rates of immune reconstitution, incidence of ADRs, and rates of treatment change were analyzed using the chi-squared test or Fisher's exact test. RESULTS: Over 95% achieved viral load 200 copies/ml or less, with no age-related difference. However, older participants exhibited significantly lower CD4+ T-cell counts and CD4+/CD8+ recovery post-ART (P < 0.001), with only 32.21% achieving immune reconstitution (compared with young: 52.16%, middle-aged: 39.29%, P < 0.001) at the end of follow-up. Middle-aged and elderly participants changed ART regimens more because of ADRs, especially bone marrow suppression and renal dysfunction. CONCLUSION: Although the virological response was consistent across age groups, older individuals showed poorer immune responses and higher susceptibility to side effects. This underscores the need for tailored interventions and comprehensive management for older patients with HIV.

Controlling structure and interfacial interaction of monolayer TaSe2 on bilayer graphene.

Tunability of interfacial effects between two-dimensional (2D) crystals is crucial not only for understanding the intrinsic properties of each system, but also for designing electronic devices based on ultra-thin heterostructures. A prerequisite of such heterostructure engineering is the availability of 2D crystals with different degrees of interfacial interactions. In this work, we report a controlled epitaxial growth of monolayer TaSe2 with different structural phases, 1H and 1 T, on a bilayer graphene (BLG) substrate using molecular beam epitaxy, and its impact on the electronic properties of the heterostructures using angle-resolved photoemission spectroscopy. 1H-TaSe2 exhibits significant charge transfer and band hybridization at the interface, whereas 1 T-TaSe2 shows weak interactions with the substrate. The distinct interfacial interactions are attributed to the dual effects from the differences of the work functions as well as the relative interlayer distance between TaSe2 films and BLG substrate. The method demonstrated here provides a viable route towards interface engineering in a variety of transition-metal dichalcogenides that can be applied to future nano-devices with designed electronic properties.

Effect of humic acid on visible light photocatalytic inactivation of bacteriophage f2 with electrospinning Cu-TiO2 nanofibers: insight into the mechanisms.

Photocatalytic disinfection is a promising technology with low cost and high efficiency. However, most of the current studies on photocatalytic disinfection ignore the widespread presence of natural organic matter (NOM) in water bodies, so the incomplete conclusions obtained may not be applicable. Herein, this paper systematically studied the influence of humic acid (HA), one of the most important components of NOM, on the photocatalytic inactivation of bacteriophage f2 with electrospinning Cu-TiO2 nanofibers. We found that with the addition of HA, the light transmittance of the solution at 550 nm decreased from 94 to 60%, and the band gap of the photocatalyst was increased from 2.96 to 3.05 eV. Compared with reacting without HA, the degradation amount of RNA of f2 decreased by 88.7% after HA was added, and the RNA concentration increased from 1.95 to 4.38 ng·µL-1 after the reaction. Hence, we propose mechanisms of the effect of HA on photocatalytic disinfection: photo-shielding, passivation of photocatalysts, quenching of free radicals, and virus protection. Photo-shielding and photocatalyst passivation lead to the decrease of photocatalyst activity, and the reactive oxygen species (ROSs) (·OH, ·O2-, 1O2, H2O2) are further trapped by HA. The HA in water also can protect the shape of phage f2 and reduce the leakage of protein and the destruction of ribonucleic acid (RNA). This work provides an insight into the mechanisms for the influence of HA in photocatalytic disinfection process and a theoretical basis for its practical application.

Associations between Parental Educational Attainment, Children's 24-h Behaviors and Children's Hyperactivity Behavior in the COVID-19 Pandemic.

BACKGROUND: Parental Educational Attainment and children's 24-h behaviors significantly influenced children's hyperactivity symptoms. This study aimed to examine the mediating role of children's 24-h behavior changes due to the COVID-19 pandemic between Parental Educational Attainment and children's hyperactivity index. It also aimed to investigate the associations between Children's Physical Activity, digital media use, sleep, and hyperactivity index between two clusters of Parental Educational Attainments. The goal was to provide targeted behavioral optimization recommendations for caregivers to reduce the risk of children's hyperactivity. METHODS: The study was a collaborative extension of the International iPreschooler Surveillance Study Among Asians and otheRs project and the Chinese Children and Adolescent Sports Health Promotion Action Project. The Parent-Surveillance of Digital Media in Childhood Questionnaire® and the Abbreviated Rating Scales from the Conners Parent Symptom Questionnaire were used to measure Parental Educational Attainment, children's behavior changes during the COVID-19 pandemic, and hyperactivity indexes. A total of 11,190 parents of 6-to-12-year-old children completed the online surveys in mainland China. A structural equation model was established by using Smart-PLS, and the linear regression model, and isotemporal substitution models were established by using a Compositional Data Analysis package with R program to achieve the research objectives. RESULTS: Changes in children's 24-h behaviors due to the COVID-19 pandemic had a significant mediation effect on the negative associations between Parental Educational Attainment and children's hyperactivity index (ß = 0.018, T = 4.521, p < 0.001) with a total effect (ß = -0.046, T = 4.521, p < 0.001) and a direct effect (ß = -0.064, T = 6.330, p < 0.001). Children's Digital Media use was significantly and negatively associated with hyperactivity index among all children. Reallocated time from digital media use to both sleep and physical activity decreased the hyperactivity index, and vice-versa. For parents without tertiary education (R2 = 0.09, p < 0.001), sleep was significantly and negatively associated with the hyperactivity index (ßilr-CSL = -0.06, p < 0.001); for parents with tertiary education (R2 = 0.07, p < 0.001), physical activity was significantly and negatively associated with the hyperactivity index (ßilr-CPA = -0.05, p < 0.001), and sleep was significantly and positively associated with the hyperactivity index (ßilr-CSL = 0.03, p < 0.001). A significant increase in the hyperactivity index was detected when physical activity time was reallocated to sleep, with a significant decrease in the opposite direction. CONCLUSIONS: Parental Educational Attainment and children's 24-h behaviors directly influenced children's hyperactivity index. However, a purposeful and targeted optimization of children's 24-h behaviors-namely, physical activity, digital media use, and sleep-could assist parents with different educational attainments to reduce their children's hyperactivity index and mitigate the risk of hyperactivity.

Unraveling sources of emission heterogeneity in Silicon Vacancy color centers with cryo-cathodoluminescence microscopy.

Diamond color centers have proven to be versatile quantum emitters and exquisite sensors of stress, temperature, electric and magnetic fields, and biochemical processes. Among color centers, the silicon-vacancy (SiV[Formula: see text]) defect exhibits high brightness, minimal phonon coupling, narrow optical linewidths, and high degrees of photon indistinguishability. Yet the creation of reliable and scalable SiV[Formula: see text]-based color centers has been hampered by heterogeneous emission, theorized to originate from surface imperfections, crystal lattice strain, defect symmetry, or other lattice impurities. Here, we advance high-resolution cryo-electron microscopy combined with cathodoluminescence spectroscopy and 4D scanning transmission electron microscopy (STEM) to elucidate the structural sources of heterogeneity in SiV[Formula: see text] emission from nanodiamond with sub-nanometer-scale resolution. Our diamond nanoparticles are grown directly on TEM membranes from molecular-level seedings, representing the natural formation conditions of color centers in diamond. We show that individual subcrystallites within a single nanodiamond exhibit distinct zero-phonon line (ZPL) energies and differences in brightness that can vary by 0.1 meV in energy and over 70% in brightness. These changes are correlated with the atomic-scale lattice structure. We find that ZPL blue-shifts result from tensile strain, while ZPL red shifts are due to compressive strain. We also find that distinct crystallites host distinct densities of SiV[Formula: see text] emitters and that grain boundaries impact SiV[Formula: see text] emission significantly. Finally, we interrogate nanodiamonds as small as 40 nm in diameter and show that these diamonds exhibit no spatial change to their ZPL energy. Our work provides a foundation for atomic-scale structure-emission correlation, e.g., of single atomic defects in a range of quantum and two-dimensional materials.

Charge density waves in two-dimensional transition metal dichalcogenides.

Charge density wave (CDW is one of the most ubiquitous electronic orders in quantum materials. While the essential ingredients of CDW order have been extensively studied, a comprehensive microscopic understanding is yet to be reached. Recent research efforts on the CDW phenomena in two-dimensional (2D) materials provide a new pathway toward a deeper understanding of its complexity. This review provides an overview of the CDW orders in 2D with atomically thin transition metal dichalcogenides (TMDCs) as the materials platform. We mainly focus on the electronic structure investigations on the epitaxially grown TMDC samples with angle-resolved photoemission spectroscopy and scanning tunneling microscopy/spectroscopy as complementary experimental tools. We discuss the possible origins of the 2D CDW, novel quantum states coexisting with them, and exotic types of charge orders that can only be realized in the 2D limit.

[Pollution Source Apportionment of Heavy Metals in Cultivated Soil Around a Red Mud Yard Based on APCS-MLR and PMF Models].

In order to explore the characteristics and sources of heavy metal pollution in cultivated soil around a red mud yard in Chongqing， the content and spatial distribution characteristics of eight heavy metal elements （Cd， Cr， Hg， Ni， Pb， As， Cu， and Zn） in the soil were analyzed， and the single factor pollution index method and Nemerow comprehensive pollution index method were used to evaluate the characteristics of heavy metal pollution in soil. On the basis of correlation analysis， the APCS-MLR and PMF models were used to quantitatively analyze the sources of heavy metals. The results showed that the average contents of the other seven heavy metal elements were higher than the background values of Chongqing soil， except for that of Cr. The heavy metals Cd， Hg， and As were moderately polluted， and Pb， Cu， Ni， and Zn were mildly polluted. The spatial distribution pattern of Cr， Ni， Pb， Cu， and Zn in the soil was similar， and there was a very significant positive correlation between them （P < 0.01）. The spatial distribution characteristics of Cd， Hg， and As were significantly different， and there was no significant correlation between them （P > 0.05）. The source apportionment showed that the sources of heavy metals in the soil in the study area were relatively complex， and the APCS-MLR and PMF models could identify the same four pollution sources， namely red mud yard percolation emission and natural sources， thermal power generation emission sources， agricultural activities and natural sources， and non-ferrous metal smelting emission sources. There was little difference in the results of source apportionment between the two models. The contribution rates of the four pollution sources in the APCS-MLR model were 51.8%， 18.0%， 15.9%， and 14.3%， respectively， whereas those in the PMF model were 45.9%， 12.8%， 21.5%， and 19.8%， respectively.

Application Research Progress of Nanomaterial Graphene and its Derivative Complexes in Tumor Diagnosis and Therapy.

Functional nanomaterial graphene and its derivatives have attracted considerable attention in many fields because of their unique physical and chemical properties. Most notably, graphene has become a research hotspot in the biomedical field, especially in relation to malignant tumors. In this study, we briefly review relevant research from recent years on graphene and its derivatives in tumor diagnosis and antitumor therapy. The main contents of the study include the graphene-derivative diagnosis of tumors in the early stage, graphene quantum dots, photodynamics, MRI contrast agent, acoustic dynamics, and the effects of ultrasonic cavitation and graphene on tumor therapy. Moreover, the biocompatibility of graphene is briefly described. This review provides a broad overview of the applications of graphene and its derivatives in tumors. Conclusion, graphene and its derivatives play an important role in tumor diagnosis and treatment.

Hydroxylation of Aryl Sulfonium Salts for Phenol Synthesis under Mild Reaction Conditions.

Hydroxylation of aryl sulfonium salts could be realized by utilizing acetohydroxamic acid and oxime as hydroxylative agents in the presence of cesium carbonate as a base, leading to a variety of structurally diverse hydroxylated arenes in 47-95% yields. In addition, the reaction exhibited broad functionality tolerance, and a range of important functional groups (e.g., cyano, nitro, sulfonyl, formyl, keto, and ester) could be well amenable to the mild reaction conditions.

Evidence for d-wave superconductivity of infinite-layer nickelates from low-energy electrodynamics.

The discovery of superconductivity in infinite-layer nickelates established another category of unconventional superconductors that shares structural and electronic similarities with cuprates. However, key issues of the superconducting pairing symmetry, gap amplitude and superconducting fluctuations are yet to be addressed. Here we utilize static and ultrafast terahertz spectroscopy to address these. We demonstrate that the equilibrium terahertz conductivity and non-equilibrium terahertz responses of an optimally Sr-doped nickelate film (superconducting transition temperature of Tc = 17 K) are in line with the electrodynamics of d-wave superconductivity in the dirty limit. The gap-to-Tc ratio (2Δ/kBTc) is found to be 3.4, indicating that the superconductivity falls in the weak coupling regime. In addition, we observed substantial superconducting fluctuations near Tc that do not extend into the deep normal state as the optimally hole-doped cuprates do. Our results support a d-wave system that closely resembles the electron-doped cuprates.

The controllable and efficient synthesis of two-dimensional metal-organic framework nanosheets for heterogeneous catalysis.

Two-dimensional (2D) MOFs exhibit unique periodicity in surface structures and thus have attracted much interest in the fields of catalysis, energy, and sensors. However, the expanded production scale of 2D MOFs had remained a great challenge in most previous studies. Herein, a controllable and efficient crystallization method for synthesizing 2D MOF nanosheets using high-gravity reactive precipitation is proposed, significantly improving heterogeneous catalysis efficiency. The two-dimensional ZIF-L nanosheets prepared in a rotating packed bed (RPB) reactor show a smaller lateral and lamellar thickness and a higher BET surface area compared to ZIF-L nanosheets prepared in a conventional stirred tank reactor (STR), with a greatly shortened reaction time. Applying the ZIF-L-RPB nanosheets as a catalyst, the catalytic Knoevenagel condensation as a probe reaction displays a high conversion rate of benzaldehyde (99.3%) within 2 h at room temperature, greatly exceeding that displayed by ZIF-L-STR and other reported catalysts. Furthermore, ZIL-L-RPB nanosheets of only 0.2 wt% enhanced the catalytic activity for the glycolysis of poly(ethylene terephthalate) (PET) with a PET conversion and a monomer yield of 90% in a short period of 15 min at 195 °C and almost completely depolymerized PET with a monomer yield of 94% in 30 min, which was far above that achieved by ZIL-L-STR. These results indicate the promising prospects of a high-gravity reactive precipitation strategy with precise size control in an economical way to prepare high-activity 2D MOF nanosheets for a wide range of heterogeneous catalysis.