Structures and growth pathways of AunCln+3- (n ≤ 7) cluster anions.

Gold chloride clusters play an important role in catalysis and materials chemistry. Due to the diversity of their species and isomers, there is still a dearth of structural studies at the molecular level. In this work, anions of AunCln+3 - and AunCln+5 - (n = 2-4) clusters were obtained by laser desorption/ionization mass spectrometry (LDI MS), and the most stable isomers of AunCln+3 - were determined after a thorough search and optimization at the TPSSh/aug-cc-pVTZ/ECP60MDF level. The results indicate that all isomers with the lowest energy have a planar zigzag skeleton. In each species, there is one Au(III) atom at the edge connected with four Cl atoms, which sets it from the other Au(I) atoms. Four growth pathways for AunCln+3 - (n = 2-7) clusters are proposed (labelled R1, R2, R3 and R4). They are all associated with an aurophilic contact and are exothermic. The binding energies tend to stabilize at ∼ -41 kcal/mol when the size of the cluster increases in all pathways. The pathway R1, which connects all the most stable isomers of the respective clusters, is characterized by cluster growth due to aurophilic interactions at the terminal atom of Au(I) in the zigzag chains. In the pathway of R4 involving Au-Au bonding in its initial structures (n ≤ 3), the distance between intermediate gold atoms grows with cluster size, ultimately resulting in the transfer of the intermediate Au-Au bonding into aurophilic interaction. The size effect on the structure and aurophilic interactions of these clusters will be better understood based on these discoveries, potentially providing new insights into the active but elusive chemical species involved in the corresponding catalytic reactions or nanoparticle synthesis processes.

Structural Characterization of the Metalized Radical Cations of Adenosine ([Ade+Li-H]•+ and [Ade+Na-H]•+) by Infrared Multiphoton Dissociation Spectroscopy and Theoretical Studies.

Nucleoside radicals are key intermediates in the process of DNA damage, and alkali metal ions are a common group of ions in living organisms. However, so far, there has been a significant lack of research on the structural effects of alkali metal ions on nucleoside free radicals. In this study, we report a new method for generating metalized nucleoside radical cations in the gas phase. The radical cations [Ade+M-H]•+ (M = Li, Na) are generated by the 280 nm ultraviolet photodissociation (UVPD) of the precursor ions of lithiated and sodiated ions of 2-iodoadenine in a Fourier transform ion cyclotron resonance (FT ICR) cell. Further infrared multiphoton dissociation (IRMPD) spectra of both radical cations were recorded in the region of 2750-3750 cm-1. By combining these results with theoretical calculations, the most stable isomers of both radicals can be identified, which share the common characteristics of triple coordination patterns of the metal ions. For both radical species, the lowest-energy isomers undergo hydrogen transfer. Although the sugar ring in the most stable isomer of [Ade+Li-H]•+ is in a (South, syn) conformation similar to that of [Ado+Na]+, [Ade+Na-H]•+ is distinguished by the unexpected opening of the sugar ring. Their theoretical spectra are in good agreement with experimental spectra. However, due to the flexibility of the structures and the complexity of their potential energy surfaces, the hydrogen transfer pathways still need to be further studied. Considering that the free radicals formed directly after C-I cleavage have some similar spectral characteristics, the existence of these corresponding isomers cannot be ruled out. The findings imply that the structures of nucleoside radicals may be significantly influenced by the attached alkali metal ions. More detailed experiments and theoretical calculations are still crucial.

Distinguishing gas phase lactose and lactulose complexed with sodiated L-arginine by IRMPD spectroscopy and DFT calculations.

We present the origin of the observed differentiation of lactose and lactulose achieved by complexation with sodiated L-arginine (ArgNa+). We find that the infrared multiphoton dissociation (IRMPD) bands in 3600-3650 and >3650 cm-1 regimes for gas phase lactose and lactulose, respectively, vanish when forming host-guest complexes with ArgNa+. We interpret these differences in the IRMPD spectra by scrutinizing the interactions between the functional groups (guanidium, -CO2-Na+) in ArgNa+ and -OHs in lactose/lactulose. Our calculated structures and infrared spectra of lactose/ArgNa+ and lactulose/ArgNa+ host-guest pairs indicate that the functional groups interact with the low- and high-frequency -OH stretch modes of lactose and lactulose, respectively, in the 3600-3720 cm-1 window.

Selective confinement of potassium, rubidium, or caesium ions in a non-covalent hydroxyproline octamer cage stabilized by cis-hydroxyl locks.

While numerous studies have focused on the impact of chirality on some magic amino acid clusters, this article investigates the effects of steric isomerization using 4-hydroxyproline octamers as a model system. Through mass spectrometry, infrared photodissociation spectroscopy, and theoretical calculation, it was demonstrated that the cis-4-hydroxy-L-proline octamer can selectively cage potassium, rubidium, or caesium ions through stable cis-hydroxyl locks, while the trans-form cannot. The results highlight the importance of hydroxyl group orientation in designing biocompatible membrane transporters with high ion-selectivity.

Simultaneous quantitative chiral analysis of four isomers by ultraviolet photodissociation mass spectrometry and artificial neural network.

Although mass spectrometry (MS) has its unique advantages in speed, specificity and sensitivity, its application in quantitative chiral analysis aimed to determine the proportions of multiple chiral isomers is still a challenge. Herein, we present an artificial neural network (ANN) based approach for quantitatively analyzing multiple chiral isomers from their ultraviolet photodissociation mass spectra. Tripeptide of GYG and iodo-L-tyrosine have been applied as chiral references to fulfill the relative quantitative analysis of four chiral isomers of two dipeptides of L/D His L/D Ala and L/D Asp L/D Phe, respectively. The results show that the network can be well-trained with limited sets, and have a good performance in testing sets. This study shows the potential of the new method in rapid quantitative chiral analysis aimed at practical applications, with much room for improvement in the near future, including selecting better chiral references and improving machine learning methods.

Genome Sequencing of Ciboria shiraiana Provides Insights into the Pathogenic Mechanisms of Hypertrophy Sorosis Scleroteniosis.

Ciboria shiraiana causes hypertrophy sorosis scleroteniosis in mulberry trees, resulting in huge economic losses, and exploring its pathogenic mechanism at a genomic level is important for developing new control methods. Here, genome sequencing of C. shiraiana based on PacBio RSII and Illumina HiSeq 2500 platform as well as manual gap filling was performed. Synteny analysis with Sclerotinia sclerotiorum revealed 16 putative chromosomes corresponding to 16 chromosomes of C. shiraiana. Screening of rapid-evolution genes revealed that 97 and 2.4% of genes had undergone purifying selection and positive selection, respectively. When compared with S. sclerotiorum, fewer secreted effector proteins were found in C. shiraiana. The number of genes involved in pathogenicity, including secondary metabolites, carbohydrate active enzymes, and P450s, in the C. shiraiana genome was comparable with that of other necrotrophs but higher than that of biotrophs and saprotrophs. The growth-related genes and plant cell-wall-degradation-related genes in C. shiraiana were expressed in different developmental and infection stages, and may be potential targets for prevention and control of this pathogen. These results provide new insights into C. shiraiana pathogenic mechanisms, especially host range and necrotrophy features, and lay the foundation for further study of the underlying molecular mechanisms.[Formula: see text] The author(s) have dedicated the work to the public domain under the Creative Commons CC0 "No Rights Reserved" license by waiving all of his or her rights to the work worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.

CircRNA Circ_0001721 Promotes the Progression of Osteosarcoma Through miR-372-3p/MAPK7 Axis.

BACKGROUND: Osteosarcoma (OS) is the most common bone tumor. Many studies have reported that circular RNAs (circRNAs) play an important role in the development of a variety of human cancers. However, the underlying mechanism of circ_0001721 in regulating osteosarcoma progression remains unknown. MATERIALS AND METHODS: Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the levels of circ_0001721, miR-372-3p, and mitogen-activated protein kinase 7 (MAPK7) in osteosarcoma tissues and cells. Besides, glycolysis was investigated by glucose consumption, lactate production and hexokinase II (HK2) protein level. Cell proliferation and apoptosis were determined by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) and flow cytometry, separately. Cell migration and invasion were determined by transwell assay. Moreover, the protein levels of HK2 and epithelial-to-mesenchymal transition (EMT) markers were determined by Western blot analysis. The relationship between miR-372-3p and circ_0001721 or MAPK7 was predicated by starbase v3.0 and confirmed by dual-luciferase reporter assay or RNA binding protein immunoprecipitation (RIP) assay. Murine xenograft model was established to investigate the role of circ_0001721 in vivo. RESULTS: The levels of circ_0001721 and MAPK7 were upregulated in osteosarcoma tissues and cells, while miR-372-3p was downregulated. Knockdown of circ_0001721 inhibited glycolysis, cell proliferation, cell migration, invasion and epithelial-to-mesenchymal transition (EMT), and promoted apoptosis. Circ_0001721 was validated as a sponge of miR-372-3p and mediated glycolysis, cell proliferation, apoptosis, migration, invasion, and EMT of osteosarcoma cells through miR-372-3p. MAPK7 was a target of miR-372-3p and overexpression of MAPK7 attenuated anti-cancer role of miR-372-3p in OS cells. Further studies revealed that circ_0001721 regulates MAPK7 expression via sponging miR-372-3-p. Finally, knockdown of circ_0001721 inhibited tumor progression in vivo. CONCLUSION: Circ_0001721 promoted osteosarcoma development through the miR-372-3p/MAPK7 axis.

Functional analysis of drought and salt tolerance mechanisms of mulberry RACK1 gene.

The receptor for activated C kinase 1 (RACK1) protein acts as a central hub for the integration of many physiological processes in eukaryotic organisms. Plant RACK1 is implicated in abiotic stress responses, but the underlying molecular mechanisms of stress adaptation remain largely unknown. Here, the overexpression of the mulberry (Morus alba L.) RACK1 gene in Arabidopsis decreased tolerance to drought and salt stresses and MaRACK1 overexpression changed expression levels of genes in response to stress and stimuli. We developed a simple and efficient transient transformation system in mulberry, and the mulberry seedlings transiently expressing MaRACK1 were hypersensitive to drought and salt stresses. The expression levels of guanine nucleotide-binding protein (G-protein) encoding genes in mulberry and Arabidopsis were not affected by MaRACK1 overexpression. The interactions between RACK1 and G-proteins were confirmed, and the RACK1 proteins from mulberry and Arabidopsis could not interact with their respective G-proteins, which indicated that RACK1 may regulate stress responses independently of G-proteins. Additionally, MaRACK1 may regulate drought and salt stress tolerances by interacting with a fructose 1, 6-bisphosphate aldolase. Our findings provide new insights into the mechanisms underlying RACK1 functions in abiotic stress responses and important information for their further characterization.

Efficacy and safety of tamsulosin for the treatment of benign prostatic hyperplasia: a meta analysis.

BACKGROUND: Pharmacological therapy has been considered as the first-line treatment for patients with uncomplicated benign prostatic hyperplasia (BPH). The aim of this study was to evaluate the efficacy and safety of tamsulosin compared with a placebo for treating BPH. METHODS: The randomized placebo-controlled trials (RCT) of tamsulosin for the treatment of BPH from all over the world were searched. PubMed, Ovid, ScienceDirect, EBSCO, CBM, and CNKI were searched, as well as a manual search of four Chinese journals: Chinese Journal of Andrology, National Journal of Andrology, Chinese Journal of Urology, and Journal of Clinical Urology was also performed. Two reviewers independently screened the studies for eligibility, evaluated the quality and extracted the data from the eligible studies, with confirmation by cross-checking. Divergences of opinions were settled by discussion. Meta-analysis was processed by Rev Man 5.0 software, fail-safe number was performed by SAS8.0 software. RESULTS: Seven RCTs involving 2455 men met the inclusion criteria. The basic characteristics of patients were comparable in all the studies. Comparing three common criteria: international prostate symptom score (IPSS)/Boyarsky symptom score, maximum flow rate (MFR), quality of life (QOL), tamsulosin was better than placebo at improving IPSS and MFR, with no significant difference in the QOL. Adverse events of tamsulosin also showed no significant difference from the placebo group (Z=1.62, P=0.10, OR=1.22, 95% CI 0.96-1.54). CONCLUSIONS: Tamsulosin is better than placebo at improving IPSS and MFR. Adverse events of tamsuloisn show no significant difference compared with placebo. More high quality trials with larger samples and longer follow-up are proposed.

[Important vaccine accidents in history of vaccine and their apocalypses].

Although it has been widely acknowledged that glorious history of vaccination of past 200 years has been a successful feat in the protection of multiple disease calamities, contamination, incomplete attenuation or high virulence of the vaccine, laboratory regulation, injection and preservation problems have witnessed many accidents in the river of history. This review would summarize and comment on typical events of accidents regarding vaccines, within the framework designed to provide experience and apocalypses