Search

Quantum walks on graphs are fundamental to quantum computing and have led to many interesting open problems in algebraic graph theory. This review article highlights three key classes of open problems in this domain: perfect state transfer, instantaneous uniform mixing, and average mixing matrices. In highlighting these open problems, our aim is to stimulate further research and exploration in this rapidly evolving field.

About 45% of the world's fruit and vegetables are wasted, resulting in postharvest losses and contributing to economic losses ranging from $10 billion to $100 billion worldwide. Soft rot disease caused by Rhizopus stolonifer leads to postharvest storage losses of sweet potatoes. Nanoscience stands as a new tool in our arsenal against these mounting challenges that will restrict efforts to achieve and maintain global food security. In this study, three nanomaterials (NMs) namely C 60 , CuO, and TiO 2 were evaluated for their potential application in the restriction of Rhizopus soft rot disease in two cultivars of sweet potato (Y25, J26). CuO NM exhibited a better antifungal effect than C 60 and TiO 2 NMs. The contents of three important hormones, indolepropionic acid (IPA), gibberellic acid 3 (GA-3), and indole-3-acetic acid (IAA) in the infected J26 sweet potato treated with 50 mg/L CuO NM were significantly higher than those of the control by 14.5%, 10.8%, and 24.1%. CuO and C 60 NMs promoted antioxidants in both cultivars of sweet potato. Overall, CuO NM at 50 mg/L exhibited the best antifungal properties, followed by TiO 2 NM and C 60 NM, and these results were further confirmed through scanning electron microscope (SEM) analysis. The use of CuO NMs as an antifungal agent in the prevention of Rhizopus stolonifer infections in sweet potatoes could greatly reduce postharvest storage and delivery losses.

This study explores the effects of nanomaterials in rice seedlings using carbon 13 ( 13 C)-labelled fullerene (C 60 ). The experiment consisted of three groups, one CK and two nano particle groups with C 60 : 100 mg L -1 and 20 mg L -1 . Mass spectrometry indicated higher 13 C abundances in the nano particle groups compared with the CK. The 13 C abundances of the 20 mg L -1 group, 100 mg L -1 group and CK were 1.0718%, 1.0715% and 1.0704%, respectively. We analyzed phytohormone concentrations in the rice at harvest time. Decreases in the concentrations of dihydrozeatin riboside (23% and 18% for the 20 mg L -1 and 100 mg L -1 group, respectively), zeatin riboside (23% and 18%, respectively), abscisic acid (11.1% and 12.7%, respectively), brassinolide (12.9% and 13.1%, respectively) and gibberellic acid 4 (12.9% and 13.1%, respectively) were observed compared with the CK. The gibberellic acid 3 concentrations in the 20 mg L -1 and 100 mg L -1 group increased by 12% and 7% compared with the CK, respectively. The methyl jasmonate concentration in the 100 mg L -1 group increased by 19.4% compared with the CK. The concentration of indole-3-acetic acid in the 100 mg L -1 group decreased by 13.5% compared with the CK. There was no change on isopentenyl adenosine concentration. This study indicates that C 60 can be absorbed by rice and its effect on the growth of rice via phytohormones, including ABA, IAA, IPA, BR, GA₃, GA₄, DHZR, ZR and JA-ME. The results showed that, under the treatments of C 60 NMs, the contents of some phytohormone in rice were decreased in comparison with CK.

Mechanisms for hematotoxicity and health effects from exposure to low doses of benzene (BZ) remain to be identified. To address the information gap, our investigation was focused onto using appropriate populations and cell cultures to investigate novel BZ-induced effects such as disruption of DNA repair capacity (DRC). From our study, abnormal miRNAs were identified and validated using lymphocytes from 56 BZ-poisoned workers and 53 controls. In addition, 173 current BZ-exposed workers and 58 controls were investigated for key miRNA expression using RT-PCR and for cellular DRC using a challenge assay. Subsequently, the observed activities in lymphocytes were verified using human HL-60 (p53 null) and TK6 (p53 wild-type) cells via 1,4-benzoquinone (1,4-BQ) treatment and miR-222 interferences. The targeting of MDM2 by miR-222 was validated using a luciferase reporter. Our results indicate induction of genotoxicity in lymphocytes from workers with low exposure doses to BZ. In addition, miR-222 expression was up-regulated among both BZ-poisoned and BZ-exposed workers together with inverse association with DRC. Our in vitro validation studies using both cell lines indicate that 1,4-BQ exposure increased expression of miR-222 and Comet tail length but decreased DRC. Loss of miR-222 reduced DNA damage, but induced S-phase arrest and apoptosis. However, silencing of MDM2 failed to activate p53 in TK6 cells. In conclusion, our in vivo observations were confirmed by in vitro studies showing that BZ/1,4-BQ exposures caused genotoxicity and high expression of miR-222 which obstructed expression of the MDM2-p53 axis that led to failed activation of p53, abnormal DRC and serious biological consequences., Competing Interests: Declaration of competing interest All authors declare that there are no conflicts of interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)

An unprecedented triple catalytic, general ring-opening cyanation reaction of cyclopropyl ketones for the construction of γ-cyanoketones is described. The key is to merge photoredox catalysis with Lewis acid catalysis and copper catalysis to enable the selective cleavage of the carbon-carbon bonds and the selective coupling of the generated radical and cyanide anion.

Transdermal drug delivery is favored in clinical therapy because of its ability to overcome the shortcomings of the first pass elimination of the liver caused by traditional oral administration and the irreversibility of the injection. However, skin stratum corneum (SC) forms a big barrier that precludes most of the biomacromolecules. Herein, we propose the engineering of transformed Escherichia coli (E. coli) derived outer membrane vesicles, detoxified by lysozymes (named TEVs) as the carrier for transdermal drug delivery. TEVs were derived from transgenic E. coli and then modified by an integrin alpha(v)beta(3) (αvβ3) targeting peptide and co-loaded with indocyanine green (ICG) (P-TEVs-G). TEVs were shown to have excellence in penetrating through intact SC without any additional enhancement, followed by targeting of melanoma cells. TEVs are promising nanoplatforms for transdermal and tumor targeting drug delivery with high efficacy and biosafety, possessing great potential in the treatment of superficial tumors.

Objective: This study investigates the mechanisms of benzene hematotoxicity., Methods: We used microarray to detect expression profiles of long non-coding RNAs (lncRNAs) and mRNAs in peripheral lymphocytes from chronic benzene poisoning, acute myelocytic leukemia, and healthy controls. The lncRNAs and mRNAs were validated using real-time quantitative PCR (RT-qPCR). Cytokinesis-block micronucleus assay was used to analyze chromosomal aberration., Results: We found 173 upregulated and 258 downregulated lncRNAs, and 695 upregulated and 804 downregulated mRNAs. The lncRNA CUST_40243 and mRNA PDGFC and CDKN1A associated with chronic benzene poisoning. Relevant inflammatory response, hematopoietic cell lineage, and cell cycle may be important pathways for the sifted lncRNAs and mRNAs. Furthermore, micronuclei frequency was significantly higher in off-post chronic benzene poisoning patients., Conclusions: Chromosomal aberration induced by benzene exposure is irreversible. The lncRNA CUST_40243 and mRNA PDGFC and CDKN1A are related to chronic benzene poisoning.

In this study, we investigated the effect of goat milk casein hydrolysates on glucose consumption rate, intracellular glycogen concentration, and mRNA expression of gluconeogenesis-related genes, including phosphoenolpyruvate carboxykinase 1 (PCK1) and glucose-6-phosphatase catalytic subunit (G6PC), in insulin-resistant HepG2 cells. From the obtained hydrolysates, we also purified and characterized novel peptides that ameliorated high-glucose-induced insulin resistance in HepG2 cells. The 3-h hydrolysate caused the highest glucose consumption rate in insulin-resistant HepG2 cells. It also showed positive effects on promoting intracellular glycogenesis and reducing mRNA expression of PCK1 and G6PC. We separated the obtained hydrolysates into 3 fractions (F1, F2, and F3) by gel filtration chromatography; we further purified F1 using reversed-phase HPLC and identified peptides using liquid chromatography-tandem mass spectrometry. The bioactive peptides identified were SDIPNPIGSE (α S1 -casein, f195-204), NPWDQVKR (α S2 -casein, f123-130), SLSSSEESITH (β-casein, f30-40), and QEPVLGPVRGPFP (β-casein, f207-219). Our findings indicated that specific bioactive peptides from goat milk casein hydrolysates ameliorated insulin resistance in HepG2 cells that had been treated with high glucose. This is a first step toward determining whether goat milk casein hydrolysates can be used as food ingredients to ameliorate insulin resistance., (Copyright © 2020 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)

Objective: To investigate the high occupational stress and its influencing factors in traffic police in Shanghai. Methods: 728 traffic police were selected as the study subjects, and the《Occupational Health Questionnaire》was used to investigate and evaluate their job demand-control (JDC) and effort-reward imbalance model (ERI) occupational stress situation respectively. The related influencing factors were analyzed. Results: The prevalence rates of high occupational stress in JDC and ERI models were 74.6% (543/728) and 51.5% (375/728) . The influencing factors of JDC were education, marriage, average weekly hours (χ(2)=16.82, 10.04, 18.71, P <0.05) , and The influencing factors of ERI were gender, age, marriage, real monthly income level, education, work experience, and average weekly hours (χ(2)=7.02, 26.18, 6.73, 50.42, 4.75, 26.61, 112.98, 6.19, P <0.05) . The JDC multivariate logistic analysis indicated that the risk of occupational stress of married police was 2.81 times as high as that of Unmarried ones. The risk of occupational stress of traffic police with more education was 1.92 times as high as that of low eduacation, average weekly working 41-50 hours and≥51 hours was 2.53, 3.12 times as high as that of ones with average working 40 hours, respectivly. Meanwhile, the ERI multivariate logistic analysis indicated that high income level is the protective factor of occupational stress. The traffic police with 15-<20 working years were more likely to occur higher occupational stress. The traffic police with the more average weekly hours had greater possibility of higher occupational stress. Conclusion: The main influencing factors of JDC and ERI are marriage, real monthly income level, education, work experience, and average weekly hours.