Enhancing Carrier Transport in 2D/3D Perovskite Heterostructures through Organic Cation Fluorination.

The interfacial 2D/3D perovskite heterostructures have attracted extensive attention due to their unique ability to combine the high stability of 2D perovskites with the remarkable efficiency of 3D perovskites. However, the carrier transport mechanism within the 2D/3D perovskite heterostructures remains unclear. In this study, the carrier transport dynamics in 2D/3D perovskite heterostructures through a variety of time-resolved spectroscopic measurements is systematically investigated. Time-resolved photoluminescence results reveal nanosecond hole transfer from the 3D to 2D perovskites, with enhanced efficiency through the introduction of fluorine atoms on the phenethylammonium (PEA) cation. Transient absorption measurements unveil the ultrafast picosecond electron and energy transfer from 2D to 3D perovskites. Furthermore, it is demonstrated that the positioning of fluorination on the PEA cations effectively regulates the efficiency of charge and energy transfer within the heterostructures. These insightful findings shed light on the underlying carrier transport mechanism and underscore the critical role of cation fluorination in optimizing carrier transport within 2D/3D perovskite heterostructure-based devices.

Thermal stability and decomposition kinetics of mixed-cation halide perovskites.

Organic-inorganic halide perovskites (OIHPs) have emerged as one of the most efficient photovoltaic materials due to their superior properties. However, improving their stability remains a key challenge. Herein, we investigate the thermal decomposition properties of OIHP FAxMA1-xPbI3 with mixed cations of formamidinium (FA) and methylammonium (MA). Using thermogravimetric analysis together with Fourier transform infrared spectroscopy, we identify and monitor the gaseous decomposition products as a function of temperature and cation composition. Thermal decomposition products of both MA and FA cations were observed at all stages of the thermal decomposition process, contrary to previous expectations. The yield, release sequence and kinetics of the organic gaseous products were found to depend strongly on the ratio between FA and MA cations. Furthermore, cesium ion doping was investigated as a potential strategy to improve the thermal stability of mixed cation perovskites. These results provide new insights into the effect of cation mixing on perovskite stability, suggesting that optimizing the cation ratios and decomposition pathways can guide approaches to boost the stability and performance of mixed cation perovskites.

Synthesis and fungicidal activity of methyl (E)-1-(2-((E)-2-methoxy-1-(methoxyimino)-2-oxoethyl)benzyl)-2-(1-arylidene)hydrazine-1-carboxylates †‡.

To discover novel strobilurin fungicides, a series of methyl (E)-1-(2-((E)-2-methoxy-1-(methoxy-imino)-2-oxoethyl)benzyl)-2-(1-arylidene)hydrazine-1-carboxylates were designed based on the principle of biologically active splicing and the receptor target structure. The fungicidal activity results show that this class of compounds has excellent fungicidal activity, especially against S. sclerotiorum (Lib.) deBary, wheat white powder and puccinia polysora. The result of structure-activity relationship implied that the introduction of t-butyl in the side chain facilitates the hydrophobic interaction between the compound and the active site. The electrostatic effect of the substituents on the benzene ring is also a key factor affecting such activities. Among them, the compound I-1 not only showed a fungicidal effect comparable to that of kresoxim-methyl in vivo, but also had an excellent inhibitory effect on spore germination of P. oryzae Cav in vitro, which indicated that it could be used as a potential commercial fungicide for plant disease control.

Fusion of near-infrared and fluorescence spectroscopy for untargeted fraud detection of Chinese tea seed oil using chemometric methods.

BACKGROUND: This paper investigated the feasibility of data fusion of near-infrared (NIR) and fluorescence spectroscopy for rapid analysis of cheap vegetable oils in Chinese Camellia oleifera Abel. (COA) oil. Because practical frauds usually involve adulterations of multiple known and unknown cheap oils, traditional analytical methods aimed at detecting one or more known adulterants are insufficient to identify adulterated COA oil. Therefore, untargeted analysis was performed by developing class models of pure COA oil using robust one-class partial least squares (OCPLS). RESULTS: The most accurate OCPLS model was obtained with fusion of standard normal variate (SNV)-NIR and SNV-fluorescence spectra with sensitivity of 0.954 and specificity of 0.91. Robust OCPLS could detect adulterations with 2% (w/w) or more cheap oils, including rapeseed oil, sunflower seed oil, corn oil and peanut oil. CONCLUSION: Fusion of NIR and fluorescence data and chemometrics provided enhanced capacity for rapid and untargeted analysis of multiple adulterations in Chinese COA oils. © 2018 Society of Chemical Industry.

Synthesis and bioactivity of 2',3'-benzoabscisic acid analogs.

2',3'-Benzoabscisic acid 4a is significantly more active than (±)-ABA and can be potentially used as a plant growth regulator for agriculture. In this study, six 4a analogs were designed and synthesized. Bioassay showed that 4a displayed greater activity than (±)-ABA and the six analogs produced less inhibition than 4a itself. Specially, some analogs displayed markedly different activities to different physiological and biochemical process, which were largely different from ABA and 4a. Compared to (±)-ABA, 4b and 4c were more effective germination inhibitors for lettuce, but less effective inhibitors for rice elongation. Five-membered analog 5 was higher or slightly weaker in inhibiting Arabidopsis seed germination and rice elongation, respectively, but at least 10 times less effective than (±)-ABA in lettuce seed germination. Dual acid 6 and alkyne acid 20 nearly produced no inhibitory activity for Arabidopsis seed germination, but displayed excellent activity in inhibiting rice seedling growth. The preference of the analogs to different physiology process indicated that they might provide a strategy to develop novel ABA agonists or antagonist and be used as probe to investigate the function of different ABA receptors.

Synthesis, Antifungal Activity and Structure-Activity Relationships of Novel 3-(Difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylic Acid Amides.

A series of novel 3-(difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylic acid amides were synthesized and their activities were tested against seven phytopathogenic fungi by an in vitro mycelia growth inhibition assay. Most of them displayed moderate to excellent activities. Among them N-(2-(5-bromo-1H-indazol-1-yl)phenyl)-3-(difluoro-methyl)-1-methyl-1H-pyrazole-4-carboxamide (9m) exhibited higher antifungal activity against the seven phytopathogenic fungi than boscalid. Topomer CoMFA was employed to develop a three-dimensional quantitative structure-activity relationship model for the compounds. In molecular docking, the carbonyl oxygen atom of 9m could form hydrogen bonds towards the hydroxyl of TYR58 and TRP173 on SDH.

Synthesis, antifungal activity and QSAR of some novel carboxylic acid amides.

A series of novel aromatic carboxylic acid amides were synthesized and tested for their activities against six phytopathogenic fungi by an in vitro mycelia growth inhibition assay. Most of them displayed moderate to good activity. Among them N-(2-(1H-indazol-1-yl)phenyl)-2-(trifluoromethyl)benzamide (3c) exhibited the highest antifungal activity against Pythium aphanidermatum (EC50 = 16.75 µg/mL) and Rhizoctonia solani (EC50 = 19.19 µg/mL), compared to the reference compound boscalid with EC50 values of 10.68 and 14.47 µg/mL, respectively. Comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) were employed to develop a three-dimensional quantitative structure-activity relationship model for the activity of the compounds. In the molecular docking, a fluorine atom and the carbonyl oxygen atom of 3c formed hydrogen bonds toward the hydroxyl hydrogens of TYR58 and TRP173.

Study on 20-hydroxyprogesterone: Chiral resolution, Content determination and Progesterone-like activity.

20-hydroxyprogesterone (20-DHP) is a natural metabolite of progesterone which occurs with two diastereoisomers: 20α-DHP and 20ß-DHP. They have drawn attention for their progesterone-like activity since the middle of the 20th century. However, the literature from that era bears witness to a lack of consensus regarding their specific effects. Considered that their stereoisomerism differences, it is essential to investigate their biological activities in vivo separately. In this study, we presented a chemical synthesis technique that yielded highly pure samples of 20α-DHP and 20ß-DHP, and performed simultaneous content analysis. Subsequently, we examined and contrasted the progesterone-like properties of 20α-DHP, 20ß-DHP, and a 1:1 mixture of 20α-DHP and 20ß-DHP. The Morphological observations of the endometrium were conducted via Haematoxylin-eosin staining. Serum hormone levels were measured using enzyme-linked immunosorbent assays. Furthermore, real-time fluorescence quantitative polymerase chain reaction and immunohistochemistry were employed to analyse the relevant mRNA and protein expression, respectively. Our comparison revealed that 20α-DHP and P4 share identical progesterone-like actions, while 20ß-DHP exhibits partial similarity. The progesterone activity varied when the two were combined in a 1:1 ratio.

Microstructure and Property Evolution of Diamond/GaInSn Composites under Thermal Load and High Humidity.

As a thermal interface material, diamond/GaInSn composites have wide-ranging application prospects in the thermal management of chips. However, studies on systematic reliability that can guide the practical application of diamond/GaInSn in the high-temperature, high-temperature impact, or high-humidity service environments that are faced by chips remain lacking. In this study, the performance evolution of diamond/GaInSn was studied under high-temperature storage (150 °C), high- and low-temperature cycling (-50 °C to 125 °C), and high temperature and high humidity (85 °C and 85% humidity). The experimental results reveal the failure mechanism of semi-solid composites during high temperature oxidation. It is revealed that core oxidation is the key to the degradation of liquid metal composites' properties under high-temperature storage and high- and low-temperature cycling conditions. Under the conditions of high temperature and high humidity, the failure of Ga-based liquid metal and its composite materials is significant. Therefore, the material should avoid high-temperature and high-humidity environments.

Synthesis and Biological Activities of Novel Pyrazole Carboxamides Containing an Aryloxypyridyl Ethylamine Module.

Pyrazole carboxamide is widely utilized in agricultural crop protection. In this research, we synthesized two classes of compounds, namely, pyrazole-5-carboxamide (4a) and pyrazole-4-carboxamide (4b), which are distinguished by the inclusion of the N-1-(6-aryloxypyridin-3-yl) ethylamine skeleton. This design was inspired by the frequent occurrence of diaryl ether modules in pesticide molecules. The bioassay results revealed that some compounds 4a exhibit higher insecticidal activity (IA) than 4b, while some compounds 4b display stronger fungicidal activity compared to 4a. This suggests that pyrazolyl plays a crucial role in determining the selectivity of these compounds toward different biological species. Notably, compound 4a-14 not only retains the potent activity of tolfenpyrad, the exact lead compound of 4a, against Lepidoptera pest Plutella xylostella and Thysanoptera pest Frankliniella occidentalis but also shows excellent IA against pests with piercing-sucking mouthparts, such as Aphis craccivora Koch and Nilaparvata lugens. This research has important implications for the control of pests with piercing-sucking mouthparts and the development of new insecticides and fungicides. The findings highlight the potential of inhibitory complex I as an effective control target for these pests, particularly those that have developed resistance to traditional insecticides. Additionally, it sheds light on the binding mode of 4b-11 and complex II, which serves as a negative reference for the design of SDHI fungicides. The study emphasizes the significance of pyrazolyl in determining selectivity in biological species and identifies avenues for future research in enhancing the biological activity of amino modules. The discovery of (S)-4a-14 not only presents a promising candidate compound for pesticide development but also provides valuable insights into the inhibitory effect of a respiratory chain complex on piercing-sucking insect pests. These findings have important implications in both theory and practice, offering new directions for pest control strategies and pesticide and fungicide development.

A highly efficient regioselective addition of acetylides to enediones based on steric effects.

A simple and efficient strategy for the synthesis of 1-ethynylcyclohex-2-enol derivatives was developed utilizing regioselective addition of acetylides to enediones based on steric effects. Further investigation of the substrate scope of enediones indicated that all the addition reactions ocurred in good yield.

Temperature and metal ions regulate larval diapause termination via the 20-hydroxyecdysone and juvenile hormone pathways in Monochamus alternatus.

BACKGROUND: Diapause allows insects to survive harsh environments, and its termination is crucial for their normal development after diapause. However, little is known about the regulatory pathways and signals involved in insect diapause termination. RESULTS: We discovered that high temperature (25 °C) influenced larval diapause termination in Monochamus alternatus. Likewise, metal ions (Ca2+ ) promoted diapause termination by reducing diapause duration. We combined transcriptomic and metabolomic analyses to investigate changes in gene expression and metabolism in diapause-terminated larvae treated with high temperature (MaHt) and metal ions (MaCa). Hormone biosynthesis and metabolism contained the highest proportion of significant differentially expressed genes (DEGs) in the two groups. 20-hydroxyecdysone (20E) and juvenile hormone (JH) were closely related to diapause termination in M. alternatus. RNA interference (RNAi) experiments verified that 20E biosynthesis (CYP314a1) and degradation (CYP18a1), JH biosynthesis (FOHSDR-1) and degradation (JHEH) genes affected the larval diapause duration significantly. In addition, dysfunction of CYP314a1 resulted in increased larval mortality (P < 0.01), reduced pupation rate and emergence rate (P < 0.05). Enzyme-linked immunosorbent assay (ELISA) analysis showed that the ecdysone content decreased after dsCYP314a1 injection and JH content increased after dsJHEH injection. CONCLUSION: The results indicate that genes CYP314a1, CYP18a1, FOHSDR-1 and JHEH mediated 20E and JH biosynthesis and degradation to regulate diapause termination in M. alternatus. We elucidated the molecular mechanism underlying the regulation of diapause termination and provided a basis for the prevention and control of M. alternatus infestation. © 2022 Society of Chemical Industry.

Fungicidal Action of the Triphenylphosphonium-Driven Succinate Dehydrogenase Inhibitors Is Mediated by Reactive Oxygen Species and Suggests an Effective Resistance Management Strategy.

Succinate dehydrogenase (SDH) is an effective target of SDH inhibitor (SDHI) fungicides which received more and more attention in recent years. However, there is no good solution to their rapidly growing drug resistance caused by frequent use. In this study, three triphenylphosphonium (TPP)-conjugated boscalid analogues were synthesized and tested for antifungal activities. They all, especially 2c, exhibited enhanced fungicidal activity and broader spectra compared to boscalid. The action mechanism study revealed that 2c was also an SDH inhibitor acting on the Qp site. However, the rapid accumulation of 2c in mitochondria because of TPP-targeting triggered reactive oxygen species burst in mitochondria, resulting in irreversible damage to the mitochondrial structure and function. Thus, 2c made the fungicidal activity output mode changing from mainly relying on ATP production inhibition (as traditional SDHIs) to significant damage of the cell structure and functions. This mechanism change made it difficult for plant pathogenic fungi to develop resistance to 2c and its analogues, which was of great significance for the increasingly challenging management of field resistance to SDHI fungicides.

Classification of organic and ordinary kiwifruit by chemometrics analysis of elemental fingerprint and stable isotopic ratios.

Elemental fingerprint, stable isotopic analysis, and chemometrics were combined to identify organic kiwifruit from ordinarily cultivated kiwifruit. Samples of organic (n1 = 78) and ordinary kiwifruit (n2 = 85) were collected from neighboring areas. For elemental fingerprint, the contents of 15 elements in fresh fruits, including Al, Cr, Mg, Pb, Zn, Ca, Cu, Mn, Se, Cd, Fe, Na, Sr, Co, and K, were determined by inductively coupled plasma optical emission spectrometry (ICP-OES). Three stable isotopes, including δ13 C, δ15 N, and δ18 O, were analyzed using an isotope-ratio mass spectrometer (IRMS). Different classification methods including soft independent modeling of class analogy (SIMCA), partial least squares discriminant analysis (PLSDA), and least squares support vector machines (LS-SVM), were used to discriminate the organic and ordinary kiwifruits by fusion of elemental and stable isotopic. As a result, the sensitivity, specificity, and overall accuracy of SIMCA model were 0.885, 0.857, and 0.864, respectively. PLSDA and LS-SVM obtained 0.950 and 0.983 classification accuracy of organic and ordinary kiwifruits, respectively. It was demonstrated that elemental fingerprint and stable isotopic analysis would provide useful chemical information for the identification of organic fruits, and the capacity of these methods could be enhanced by chemometrics. PRACTICAL APPLICATION: The classification of kiwifruit usually relies on the label assigned by the merchant, which is prone to deceive consumers. This research has developed an accurate and effective classification method based on stable isotopes and mineral elements for the identification of ordinary kiwifruit and organic kiwifruit, providing a tool for the quality monitoring of organic food.

The genus Passaloecus Shuckard (Hymenoptera: Crabronidae) from China with four new species and two new records.

Four new species of genus Passaloecus Shuckard, (Crabronidae: Pemphredoninae: Pemphredonini) from China are described, namely P. bisulcatus Bashir Ma, sp. nov., P. profundesulcatus Bashir Ma, sp. nov., P. tuberangustus Bashir Ma, sp. nov., and P. tuberculiformis Bashir Ma, sp. nov. In addition, eight Palearctic species are reported, of which P. turanicus Gussakovskij and P. turionum Dahlbom are first records for China. A key to the species of Passaloecus from China is provided.

A new fungicidal lactone from Xylocarpus granatum (Meliaceae).

A new lactone was isolated from the leaves of Xylocarpus granatum, along with three known compounds: triacontanol, beta-sitosterol and kaempferol-3-O-beta-D-glucoside. Its structure was elucidated as 3-(1-hydroxyethyl)-4,4-dimethyl-4-butyrolactone (1) by infrared, (1)H and (13)C NMR and ESI-MS data. At a concentration of 20 microg mL(-1), the new lactone gave a 67.4% inhibition rate against wheat powdery mildew.