Pion and Kaon Distribution Amplitudes from Lattice QCD.

We present a state-of-the-art lattice QCD calculation of the pion and kaon light-cone distribution amplitudes (DAs) using large-momentum effective theory. The calculation is done at three lattice spacings a≈{0.06,0.09,0.12} fm and physical pion and kaon masses, with the meson momenta P_{z}={1.29,1.72,2.15} GeV. The result is nonperturbatively renormalized in a recently proposed hybrid scheme with self-renormalization, and extrapolated reliably to the continuum as well as the infinite momentum limit. We find a significant deviation of the pion and kaon DAs from the asymptotic form, and a large SU(3) flavor breaking effect in the kaon DA.

The intervention effect of mental health knowledge integrated into ideological and political teaching on college students' employment and entrepreneurship mentality.

In order to analyze the intervention effect of integrating mental health knowledge into ideological and political teaching on college students' employment and entrepreneurship mentality, this paper proposes a study to predict the effect of integrated intervention. This research mainly investigates the ideological and psychological conditions of college students from divorced families through questionnaires, compares and analyzes the classification and statistical results of the survey data between groups and within groups, and analyzes the reasons for the ideological and psychological problems of college students. The experimental results show that 30% of college students from divorced families and college students from non-divorced families responded that they do not feel comfortable in places with many people, and the difference between the groups is not significant. Regarding the concept of entrepreneurship, 64.63% of college students from divorced families in urban areas believe that entrepreneurship is a form of learning and should be encouraged. 63.27% of college students from divorced families in rural areas believe that learning should be the first priority and that a business should not be started. 20.41% of college students from divorced families in rural areas and 25.61% of college students from divorced families in urban areas believe that because entrepreneurship provides economic income, it can reduce the burden on families, but the difference is not obvious. In short, this study can provide reference for the ideological and psychological status of college students from divorced families.

Purine Nucleoside Derivatives Containing a Sulfa Ethylamine Moiety: Design, Synthesis, Antiviral Activity, and Mechanism.

To find efficient and broad-spectrum viral agents, a series of purine nucleoside derivatives containing sulfa ethylamine moieties was designed and synthesized, and their antiviral activities against tobacco mosaic virus (TMV), cucumber mosaic virus (CMV), and potato virus Y (PVY) were evaluated. Some target compounds displayed good antiviral activities. Among them, compound 3 showed excellent protective activity against CMV and PVY with 50% effective concentration values (EC50) of 137 and 209 µg/mL, respectively, which were better than that of the control agent ningnanmycin (508 and 431 µg/mL). Moreover, the EC50 value of compound 3 for the inactivating activity against TMV was 48 µg/mL, which was better than that of ningnanmycin (88 µg/mL). In addition, compound 3 not only destroyed the structure of the TMV virus but also had a good interaction with the coat protein of the TMV virus. Therefore, compound 3 may further destroy the structure of the virus by binding to the coat protein of the TMV virus, thereby weakening the infectivity of the virus.

Discovery of Dithioacetal Derivatives Containing Sulfonamide Moiety of Novel Antiviral Agents by TMV Coat Protein as a Potential Target.

Tobacco mosaic virus coat protein (TMV CP) plays an important role in viral replication, translation, and intracellular and intercellular movements. Thus, TMV CP could be regarded as a potential target for antiviral agents. In this study, in order to find out whether dithioacetal derivatives act on the CP target, a series of dithioacetal derivatives containing sulfonamide moiety was first designed and synthesized. Bioassay results demonstrated that Y14, Y18, and Y21 exhibited excellent activities against TMV, with half-maximal effective concentrations (EC50) of the curative, protective, and inactivate activities being 183.0 ± 3.2, 252.3 ± 2.6, and 63.8 ± 1.2 µg/mL, 270.6 ± 3.7, 249.7 ± 3.5, and 57.7 ± 1.4 µg/mL, and 329.5 ± 1.5, 269.2 ± 3.7, and 48.1 ± 2.0 µg/mL for Y14, Y18, and Y21, respectively, which were higher than those for the control agents ningnanmycin (331.0 ± 2.8, 271.0 ± 2.8, and 77.4 ± 1.3 µg/mL, respectively) and d2 (471.5 ± 1.4, 447.2 ± 2.1, and 91.7 ± 1.8 µg/mL, respectively). Transmission electron microscopy showed that the particle morphology of TMV was destroyed by Y21, and microscale thermophoresis (MST) showed that Y21 bonded to CP with a dissociation constant (K d) of 9.7 ± 1.7 µM. Then, molecular docking and MST further illustrated that Y21 had a weak binding affinity with the TMV mutant protein (K d = 561.3 ± 83.2 µM). Thus, we deduced that the dithioacetal derivative Y21 may inhibit TMV activity by binding TMV CP. This work provides some new insights for the design and optimization of novel anti-TMV agents.

Design, synthesis, anti-TMV activity, and preliminary mechanism of cinnamic acid derivatives containing dithioacetal moiety.

A series of cinnamic acid derivatives, which contained dithioacetal moiety, were designed and synthesized, and their anti-plant virus activity against Tobacco mosaic virus (TMV) were evaluated. Most target compounds exhibited good anti-plant virus activities. Compound 2y, especially at 500 mg/L concentration, had an excellent activity against TMV, and its curative, protective, and inactivating activities were 62.5%, 61.8%, and 83.5%, respectively. These activity values were significantly superior to those of ribavirin (45.9%, 39.8%, and 70.3%) and xiangcaoliusuobingmi (44.7%, 48.3%, and 71.7%) and comparable to those of ningnanmycin (61.9%, 53.3%, and 85.2%). Compound 2y presented an EC50 value of 50.7 mg/L for inactivating activity against TMV, which was superior to those of ningnanmycin (51.5 mg/L), ribavirin (160.4 mg/L), and xiangcaoliusuobingmi (83.0 mg/L). Through transmission electron microscopy, we found that compound 2y caused a certain degree of damage to TMV particles, which caused them to break and bend. Four conventional hydrogen bonds were formed with amino acid residues GLN34, THR37, ARG90, and ARG46 of TMV coat protein (CP) through molecular docking. Microscale thermophoresis test results showed that compound 2y with TMV CP had a strong binding force, and the dissociation constant (Kd) was 1.6 µM. In summary, the cinnamic acid derivatives containing dithioacetal moiety provide a foundation for further research on antiviral agents.

Design, synthesis, bioactivity and mechanism of dithioacetal derivatives containing dioxyether moiety.

The present work designed and synthesized a series of dithioacetal derivatives containing dioxyether, as well as evaluated their antiviral activities against tobacco mosaic virus (TMV). Bioassays demonstrated that the target compounds showed excellent anti-TMV activities in vivo and in vitro. Compound 24c has excellent anti-TMV activities, and its curative, protective and inactivating activities for TMV were 50.9%, 58.9% and 81.8%, respectively, which are obviously superior to those of ribavirin (50.2%, 41.3% and 69.5%, respectively). Moreover, the EC50 of the inactivating activities of the anti-TMV of compound 24c is 67.9 mg/L, which is superior to that of ribavirin (149.5 mg/L). Transmission electron microscopy showed that compound 24c caused great damage to the morphology of TMV particles, causing fracture and bending. Molecule docking model revealed that this compound formed five conventional hydrogen bonds with the active sites of amino acids GLN57, ASN73, TYR139, and SER138. Furthermore, the test results of Fluorescence titration and microscale thermophoresis showed that compound 24c has a strong binding force with TMV coat protein (TMV CP), with an association constant (Ka) of 1.04 × 105 L/mol and dissociation constant (Kd) of 1.6 ±â€¯0.6 µM. These results indicate that the dithioacetal derivatives containing dioxyether are worthy of further research and development as novel antiviral agents.

Synthesis, Antiviral Activity, and Mechanisms of Purine Nucleoside Derivatives Containing a Sulfonamide Moiety.

Novel purine nucleoside derivatives containing a sulfonamide moiety were prepared, as well as their antiviral activities against potato virus Y (PVY), cucumber mosaic virus (CMV), and tobacco mosaic virus (TMV) were evaluated. The antiviral mechanisms of the compounds were investigated. Results showed that most of the compounds had good antiviral activities. Compound 5 at 500 µg/mL exhibited excellent curative and protective activities of 52.5% and 60.0% and of 52.0% and 60.2% for PVY and CMV, respectively, which are higher than those of ningnanmycin (48.1%, 49.6%; 45.3%, 47.7%), ribavirin (38.3%, 48.2%; 40.8%, 45.5%), and chitosan oligosaccharide (32.5%, 33.8%; 35.1%, 34.6%). Moreover, compound 5 displayed good inactivating activity against TMV, with an EC50 value of 48.8 µg/mL, which is better than that of ningnanmycin (84.7 µg/mL), ribavirin (150.4 µg/mL), and chitosan oligosaccharide (521.3 µg/mL). The excellent antiviral activity of compound 5 is related to its immune induction effect which can regulate the physiological and biochemical processes in plants, including defense-related enzyme activities, defense-related genes, and photosynthesis-related proteins. These results indicate that purine nucleoside derivatives containing a sulfonamide moiety are worthy of further research and development as new antiviral agents.

Novel 1,3,4-Oxadiazole Derivatives Containing a Cinnamic Acid Moiety as Potential Bactericide for Rice Bacterial Diseases.

Rice bacterial leaf blight and leaf streak are two important bacterial diseases of rice, which can result in yield loss. Currently, effective antimicrobials for rice bacterial diseases are still lacking. Thus, to develop highly effective and low-risk bactericides, 31 novel 1,3,4-oxadiazole derivatives containing a cinnamic acid moiety were designed and synthesized. Bioassay results demonstrated that all compounds exhibited good antibacterial activities in vitro. Significantly, compounds 5r and 5t showed excellent antibacterial activities against Xanthomonas oryzae pv. oryzae (Xoo) and X. oryzae pv. oryzicola (Xoc), with the 50% effective concentration (EC50) values of 0.58 and 0.34, and 0.44 and 0.20 µg/mL, respectively. These compounds were much better than thiodiazole copper (123.10 and 161.52 µg/mL) and bismerthiazol (85.66 and 110.96 µg/mL). Moreover, compound 5t had better protective and curative activities against rice bacterial leaf blight and leaf streak than thiodiazole copper and bismerthiazol in vivo. Simultaneously, the in vivo efficacy of the compounds was demonstrated by real-time quantitative PCR to quantify bacterial titers. In addition, a three-dimensional quantitative structure⁻activity relationship model was created and presented good predictive ability. This work provides support for 1,3,4-oxadiazole derivatives containing a cinnamic acid moiety as a potential new bactericide for rice bacterial diseases.

Carbene-Catalyzed [4 + 2] Cycloadditions of Vinyl Enolate and (in Situ Generated) Imines for Enantioselective Synthesis of Quaternary α-Amino Phosphonates.

A carbene-catalyzed enantioselective addition of enals to five-membered cyclic imines is developed. The reaction gives chiral quaternary α-amino phosphonates bearing tetrasubstituted carbon centers with excellent enantioselectivities. The imine substrates can be generated in situ from the corresponding amines under an oxidative condition that is compatible with the carbene catalysis. Thus, a one-pot cross-dehydrogenative-coupling (CDC) reaction between enals and amines is also realized with high enantioselectivity remaining. The method provides quick enantioselective access to amino phosphonates with potential applications in medicines and pesticides.

Antiviral properties and interaction of novel chalcone derivatives containing a purine and benzenesulfonamide moiety.

A new concise and facile method was explored to synthesize a series of novel chalcone derivatives containing a purine and benzenesulfonamide moiety and their antiviral properties were evaluated against TMV and CMV. Biological assays indicated that several of the derivatives exhibited significant anti-TMV and anti-CMV activities in vivo. In particular, compound d2 displayed excellent inactivating activity against TMV, with the EC50 value of 51.65 µg/mL, which was better than that of ribavirin (150.45 µg/mL). Molecular docking showed that there are four hydrogen bonds between compound d2 and TMV coat protein (TMV-CP). Compound d2 demonstrated strong binding capacity to TMV-CP with Ka = 1.58 × 105 L/mol and Kd = 12.16 µM. These findings indicated that chalcone derivatives are worthy of further research and development as templates for new antiviral agents.

Carbene-catalyzed enal γ-carbon addition to α-ketophosphonates for enantioselective access to bioactive 2-pyranylphosphonates.

A carbene-catalyzed enantioselective [4+2] cycloaddition reaction between α,ß-unsaturated aldehydes and α-ketophosphonates is developed. The reaction affords chiral 2-pyranylphosphonates with excellent enantioselectivities. The optically enriched phosphonate products bear multiple functional groups, including unsaturated lactone and phosphonate moieties that often lead to unique bio-activities. Preliminary studies show that the products from our reactions exhibit anti-bacterial (X. oryzae pv. oryzae) and anti-viral (Tobacco Mosaic Virus) activities for potential use in plant protection.

Synthesis and Antiviral Activity of Novel 1,4-Pentadien-3-one Derivatives Containing a 1,3,4-Thiadiazole Moiety.

1,4-Pentadien-3-one derivatives derived from curcumin possess excellent inhibitory activity against plant viruses. On the basis of this finding, a series of novel 1,4-pentadien-3-one derivatives containing a 1,3,4-thiadiazole moiety were designed and synthesized, and their structures confirmed by IR, ¹H-NMR, and 13C-NMR spectroscopy and elemental analysis. The antiviral activities of the title compounds were evaluated against tobacco mosaic virus (TMV) and cucumber mosaic virus (CMV) in vivo. The assay results showed that most of compounds had remarkable antiviral activities against TMV and CMV, among which compounds 4b, 4h, 4i, 4k, 4o, and 4q exhibited good curative, protection, and inactivation activity against TMV. Compounds 4h, 4i, 4k, 4l, 4o, and 4q exhibited excellent protection activity against TMV, with EC50 values of 105.01, 254.77, 135.38, 297.40, 248.18, and 129.87 µg/mL, respectively, which were superior to that of ribavirin (457.25 µg/mL). In addition, preliminary SARs indicated that small electron-withdrawing groups on the aromatic ring were favorable for anti-TMV activity. This finding suggests that 1,4-pentadien-3-one derivatives containing a 1,3,4-thiadiazole moiety may be considered as potential lead structures for discovering new antiviral agents.