The Fe(iii)-catalyzed decarboxylative cycloaddition of β-ketoacids and 2H-azirines for the synthesis of pyrrole derivatives

An Fe(iii)-catalyzed Mannich/decarboxylative ring expansion reaction to generate pyrrole derivatives has been achieved using Fe(OTf)₃ as the catalyst. A series of pyrrole derivatives was obtained in moderate to excellent yields.

Association of Circulating Retinol and α-TOH Levels with Cognitive Function in Aging Subject with Type 2 Diabetes Mellitus

OBJECTIVES

Malnutrition of vitamin A (retinol) and vitamin E (α-tocopherol, α-TOH) was observed in type 2 diabetes mellitus (T2DM) or dementia patients. However, how these vitamins affect cognitive function of subjects with T2DM was seldom reported. The objective of this study was to determine the association of circulating retinol and α-TOH with cognition in aging subjects with T2DM.

METHODS

A total of 448 T2DM subjects and 448 age, gender and education matched control subjects (aged 55-75 years) were included in the study. Demographic characters of the participants were collected. Food frequency questionnaire (FFQ) method was used to collect dietary intake information. To assess the status of cognition, the MoCA test was used. Circulating retinol and α-TOH levels were compared between T2DM and non-T2DM subjects. Correlation of circulating retinol and α-TOH levels with cognitive function was analyzed in T2DM subjects. The effect of serum retinol and α-TOH levels on the risk of MCI in T2DM patients was explored.

RESULTS

We found that T2DM-MCI subjects demonstrate lower serum retinol level than T2DM-nonMCI subjects (P < 0.01). Serum retinol level was positively correlated to cognitive function in T2DM subject (P < 0.05). T2DM subjects with higher circulating retinol level demonstrate higher cognitive scores in visual and executive, attention, language, memory and delayed recall domains (P < 0.05).

CONCLUSION

Diminished circulating retinol predicts an increased risk of MCI in T2DM patients. Our findings provide suggestions that optimal retinol nutritional status might benefit cognition and decrease the risk of MCI in aging subjects with T2DM.

Chiral ScIII-N,N'-Dioxide-Catalyzed 1,3-Dipolar Cycloaddition of Diaziridines with Chalcones

A highly enantioselective 1,3-dipolar cycloaddition of meso-diaziridines with chalcones was realized by utilizing the Sc^III-N,N'-dioxide complex as the catalyst. In this transformation, the 1,3-dipole intermediates generated from the C-N bond cleavage of diaziridine were trapped by chiral N,N'-dioxide/scandium(III) complex activated chalcones to undergo enantioselective 1,3-dipolar cycloaddition. A range of chiral 1,5-diazabicylo[3.3.0]octane derivatives were readily synthesized in good yields with high diastereo- and enantioselectivities.

Reconfigurable sensor and nanoantenna by graphene-tuned Fano resonance

With the rapid developments in compact devices, the multi-function and reconfigurability of nanostructures are highly appreciated, while still very challenging. A majority of devices are usually mono-functional or hard to switch between different functions in one design. In this paper, we proposed graphene-wrapped core-shell nanowires to realize real-time reconfigurable sensors and nanoantenna by tuning the Fermi energies of graphene layers at the surfaces of core and shell, respectively. Owing to the electromagnetic coupling between the two graphene layer, two corresponding Fano resonances of scattering can arise in the Terahertz spectrum, which arises from the interference of bright modes and dark modes. Around the Fano resonances, the scattering can be considerably resonant (as an antenna) or suppressed (as a sensor). Interestingly, the field distributions are distinct at the suppressed scattering states for the two Fano resonances. The presented reconfigurable nanostructures may offer promising potentials for integrated and multi-functional electromagnetic control such as dynamic sensing and emission.

Identification of New QTL Contributing to Barley Yellow Dwarf Virus-PAV (BYDV-PAV) Resistance in Wheat

Barley yellow dwarf (BYD) is a major virus disease which dramatically reduces wheat yield. Introducing BYD resistance genes into commercial varieties has been proven to be effective in reducing damage caused by barley yellow dwarf virus (BYDV). However, only one major resistance gene is readily deployable for breeding; Bdv2 derived from Thinopyrum intermedium is deployed as a chromosomal translocation. In this study, a double haploid (DH) population was developed from a cross between XuBYDV (introduced from China showing very good resistance to BYD) and H-120 (a BYD-sensitive Chinese accession), and was used to identify QTL for BYD resistance. The population was genotyped using an Infinium iSelect bead chip array targeting 90K gene-based SNPs. The disease resistance of DH lines inoculated with BYDV was assessed at the heading stage. The infections were assessed by tissue blot immunoassay (TBIA). Three new QTL were identified on chromosomes 5A, 6A, and 7A for both symptom and TBIA, with all three resistance alleles being inherited from XuBYDV. Some DH lines with the resistance alleles from all three QTL showed high level resistance to BYD. These new QTL will be useful in breeding programs for pyramiding BYD resistance genes.

P742Effects of platelet microparticles on the formation and stability of atherosclerotic plaque in ApoE knockout mice

Background

After activation by different factors, platelets can release a large number of platelet microparticles (PMPs), and continue to play a more durable and extensive role in promoting inflammation and thrombosis. Previous studies by our group have shown that PMPs can promote endothelial cell migration and lumen formation in vitro, and promote the release of inflammatory factors from monocytes. However, it is unclear whether PMPs can promote angiogenesis in the plaque and promote vascular wall inflammation and further lead to plaque instability.

Purpose

To investigate the effect of platelet microparticles (PMPs) from C57BL/6 mice on promoting atherosclerotic plaque formation and plaque stability in ApoE−/− mice.

Methods

Forty male apolipoprotein E knockout (ApoE−/−) mice, aged 8 weeks and fed for 4 weeks with high-fat diet, were randomly divided into four groups (n=10 in each group)according to the table of random digit. The mice were respectively injected with PBS (PBS group), PMPs-free supernatants (SUP group), low-dose PMPs (LDP group) and high-dose PMPs (HDP group) once a week through tail vein injection for 8 weeks. At the end of the experiment, the mice were euthanized and the blood samples were collected to detect blood routine, blood lipids, liver and kidney function and inflammatory factors including CRP, IL-1β, TNF-α; The aorta and brachiocephalic trunk were sampled to detect the atherosclerotic plaque formation. Oil Red O staining, H&E staining, Masson staining and immunohistochemistry (CD68, MMP-9, α-SMA) were used to examine the stability of the atherosclerotic plaque in each group.

Results

There were no significant differences in body weight, blood routine (WBC, RBC, PLT, HGB), blood lipids (TG, TCH, LDL, HDL), liver (ALT, AST)and kidney function (UN, Cr)in each group. The levels of serum CRP, IL-1β and TNF-α in LDP group and HDP group were significantly higher than those in PBS group and SUP group (P<0.05). The total area of aortic atherosclerotic plaques in LDP group and HDP group were significantly greater than those in PBS group and SUP group (P<0.05). Compared with the PBS group, the lipid cores of the plaques in the other three groups were significantly increased (P<0.05). The content of collagen and the amount of smooth muscle cells in the plaques were significantly lower in HDP group than in PBS group (P<0.05), while macrophages increased significantly in HDP group (P<0.05).

Conclusion

PMPs promote the formation of atherosclerotic plaques in high-fat-fed ApoE−/− mice, as well as macrophage infiltration and inflammation in the plaques, reduce the content of collagen and the amount of smooth muscle cells, thus decreasing the stability of plaques.

Emergence of ceftazidime/avibactam resistance in carbapenem-resistant Klebsiella pneumoniae in China

OBJECTIVES

The aim was to investigate the activity of ceftazidime/avibactam (CAZ/AVI) against carbapenem-resistant Klebsiella pneumoniae (CRKP) and identify the resistance mechanisms before CAZ/AVI coming to Chinese market.

METHODS

Clinical CRKP isolates were continuously collected from 36 tertiary hospitals in China from 1 March 2017 to 31 July 2017. CAZ/AVI MICs were determined by agar dilution method. CAZ/AVI resistant isolates were submitted to whole genome sequencing. The copy number and relative expression of bla_KPC were determined by quantitative PCR.

RESULTS

A total of 872 CRKP isolates were collected, and MIC₅₀ and MIC₉₀ of CAZ/AVI were 4 and 8 mg/L. The resistant rate of CAZ/AVI was 3.7% (32/872). Among the resistant isolates, 53.1% (17/32) were metallo-β-lactamase-producing K. pneumoniae (MBL-KP), 40.6% (13/32) were Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae (KPC-KP) and 6.3% (2/32) produced both MBL and KPC. One of the KPC-KP with high level CAZ/AVI resistance (>128 mg/L) harboured mutated bla_KPC-2 (D179Y). In 12 wild-type bla_KPC-2 isolates, the relative copy number and expression of bla_KPC-2 gene were 2.5-fold and 2.7-fold higher than that in the CAZ/AVI MIC ≤0.5 mg/L group (p < 0.05), and when added avibactam at a fixed concentration of 8 mg/L, 91.7% (11/12) isolates could restore susceptibility.

CONCLUSIONS

Resistance against CAZ/AVI in CRKP emerged before clinical use of CAZ/AVI in China, although most of the CRKP isolates maintained the susceptibility. MBL production, bla_KPC-2 point mutation and high KPC expression played an important role in CAZ/AVI resistance.

Ab initio QED Treatment of the Two-Photon Annihilation of Positrons with Bound Electrons

The process of a positron-bound-electron annihilation with simultaneous emission of two photons is investigated theoretically. A fully relativistic formalism based on an ab initio QED description of the process is worked out. The developed approach is applied to evaluate the annihilation of a positron with K-shell electrons of a silver atom, for which a strong contradiction between theory and experiment was previously stated. The results obtained here resolve this longstanding disagreement and, moreover, demonstrate a sizable difference with approaches so far used for calculations of the positron-bound-electron annihilation process, namely, Lee's and the impulse approximations.

Analysis of the Forensic Identification of Medical Disputes Related to 22 Cases of Death from Otolaryngology Diseases

Abstract

Objective To discuss the causes and precautionary measures of the risks of relevant medical disputes by analyzing 22 cases of death from otolaryngology diseases. Methods A retrospective analysis of 22 judicial expertise cases of medical disputes related to death from otolaryngology diseases accepted by Chongqing Zhengding Judicial Appraisal Institute and Academy of Forensic Science during 2008-2018 were made. Results Of the 22 cases, the male to female ratio was 3.4∶1. The age of death was from 1.3 to 76 years old, with an average age of 45.3 years. There were 28 medical institutions involved, of which 71.4% were tertiary medical institutions. Statistics for death causes showed that respiratory asphyxia accounted for 50%. Conclusion Forensic identification provides an important scientific basis for medical disputes cases related to otolaryngology diseases. It also has an important reference value for medical institutions to optimize the work procedure of diagnosis and treatment of otolaryngology diseases and improve the quality of diagnosis and treatment.

[Epidemiological investigation of burn patients with Klebsiella pneumoniae infection and the analysis of risk factors for sepsis in them]

Objective: To analyze the prevalence trend of Klebsiella pneumoniae (KP) infection in the Department of Burns of the Second Affiliated Hospital of Zhejiang University School of Medicine (hereinafter referred to as the author's department) from 2015 to 2017, and to screen out the independent risk factors for sepsis in burn patients with KP infection. Methods: The clinical and bacteriological data of burn patients with KP infection from January 1, 2015 to December 31, 2017 were collected from the author's department. The variation trend in infection rates of KP and carbapenems-resistant KP (CRKP) during the three years were statistically analyzed, and the data were processed with chi-square test. Clinical data were processed with binary logistic regression analysis to screen out the independent risk factors for sepsis in burn patients with KP infection. Results: (1) From 2015 to 2017, 91 patients (50 males and 41 females, aged 15-90 years) with KP infection were diagnosed in the author's department, of which 65 cases were CRKP positive, and 26 cases were carbapenems-sensitive KP positive. The KP infection rates of patients in 2015, 2016, and 2017 were 5.79% (35/605), 4.08% (23/564), and 5.54% (33/596), respectively. The CRKP infection rates of patients in 2015, 2016, and 2017 were 3.31% (20/605), 3.37% (19/564), and 4.36% (26/596), respectively. There were no statistically significant differences in KP infection rate and CRKP infection rate of patients among the three years (χ(2)=2.007, 1.175, P>0.05). (2) Total burn area and CRKP infection were independent risk factors for sepsis in burn patients with KP infection (odds ratios=1.03, 5.88, 95% confidence intervals=1.01-1.05, 1.08-31.94, P<0.05). Conclusions: From 2015 to 2017, the infection rates of KP and CRKP in the author's department did not increase obviously, but the proportion of CRKP infection was high. CRKP infection is one of the independent risk factors for sepsis in burn patients with KP infection. Strengthening the prevention and treatment of CRKP infection may have certain value in decreasing the incidence of burn sepsis.

[Advances in the research of protective effect of curcumin on intestinal mucosal barrier function]

As a natural extract from turmeric, curcumin has extensive pharmacological effects, such as anti-tumor, anti-inflammation, anti-oxidative stress, anti-microbial, immunoregulation and so on. In recent years, an increasing number of basic and clinical researches have shown that curcumin takes therapeutic effects on various diseases, such as gastrointestinal diseases, cardiovascular diseases, autoimmune diseases, neuropsychiatric diseases and so on. Many of the pharmacological effects and mechanisms of curcumin are associated with protective effects of intestinal mucosal barrier. It can protect intestinal mucosal barrier through mutiple pathways, including anti-inflammation, anti-oxidative stress, anti-bacterial, anti-apoptosis, regulating intestinal microecology and intestinal immune response and so on. This paper summarizes the protective effects of curcumin on intestinal barrier function and the mechanism, in order to provide new ideas for diagnosis and treatment of intestinal dysfunction.