Abstract Objectives Many studies have shown that insomnia is a common problem among university students, but there are wide variations in the prevalence of insomnia. In this systematic review, we ...aimed to explore the prevalence of insomnia among university students using scientific and conclusive methods. Study design A systematic review is designed to analyze the studies reporting on prevalence of insomnia among university students. Methods Systemic searches were conducted in PubMed, BioMed Central, EBSCO, ScienceDirect, Ovid LWW and Medline databases between January 2000 and July 2014, The Meta analyst software was used to calculate the prevalence rate of each study, the pooled means of prevalence rates and 95% CIs across studies were then calculated and presented. Results Seven articles that met the inclusion and exclusion criteria were selected. The overall sample size in the current review was 16,478, with a minimum of 219 and a maximum of 10,322. The prevalence rates of the seven studies ranged between 9.4% (95%CI 8.8–10.0%) and 38.2% (95% CI 35.4–41.1%). Overall, the total students studied with a weighted mean prevalence of 18.5% (95% CI 11.2–28.8%), considerably higher than rates of 7.4% (95% CI 5.8–9.0%) reported in general population. Conclusions This review emphasized that insomnia prevalence in university students is considerably higher than that in general population, suggested that more attention should be paid to insomnia in university students.
The RNA-guided endonuclease Cas9 has made genome editing a widely accessible technique. Similar to Cas9, endonucleases from the Argonaute protein family also use oligonucleotides as guides to degrade ...invasive genomes. Here we report that the Natronobacterium gregoryi Argonaute (NgAgo) is a DNA-guided endonuclease suitable for genome editing in human cells. NgAgo binds 5' phosphorylated single-stranded guide DNA (gDNA) of ∼24 nucleotides, efficiently creates site-specific DNA double-strand breaks when loaded with the gDNA. The NgAgo-gDNA system does not require a protospacer-adjacent motif (PAM), as does Cas9, and preliminary characterization suggests a low tolerance to guide-target mismatches and high efficiency in editing (G+C)-rich genomic targets.
The underlying mechanisms of wound healing are complex but inflammation is one of the determining factors. Besides its traditional role in combating against infection upon injury, the characteristics ...and magnitude of inflammation have dramatic impacts on the pathogenesis of scar. Keloids and hypertrophic scars are pathological scars that result from aberrant wound healing. They are characterized by continuous local inflammation and excessive collagen deposition. In this review, we aim at discussing how dysregulated inflammation contributes to the pathogenesis of scar formation. Immune cells, soluble inflammatory mediators, and the related intracellular signal transduction pathways are our three subtopics encompassing the events occurring in inflammation associated with scar formation. In the end, we enumerate the current and potential medicines and therapeutics for suppressing inflammation and limiting progression to scar. Understanding the initiation, progression, and resolution of inflammation will provide insights into the mechanisms of scar formation and is useful for developing effective treatments.
Flavonoids are a group of polyphenolic compounds, diverse in chemical structure and characteristics, found ubiquitously in plants. Until now, more than 9000 different flavonoid compounds were ...described in plants, where they play important biological roles by affecting several developmental processes. There has been increasing interest in the research of flavonoids from dietary sources, due to growing evidence of the versatile health benefits of flavonoids including anti-inflammatory, antioxidant, antiproliferative and anticancer activity, freeradical scavenging capacity, antihypertensive effects, coronary heart disease prevention and anti-human immunodeficiency virus functions. This paper reviews the current advances in flavonoids in food with emphasis on mechanism aspects on the basis of the published literature, which may provide some guidance for researchers in further investigations and for industries in developing practical health agents.
A new ultrahigh strength Cu-6.0 Ni-1.0 Si-0.5 Al-0.15 Mg-0.1 Cr alloy has been developed by alloying design and thermal mechanical treatment. Electrical conductivity, mechanical properties of the ...designed alloy such as hardness, tensile strength, yield strength, elongation and anti-stress relaxation resistance were tested. The mechanical properties and electrical properties of designed alloy were comparable to those of Cu–Be alloys, and its anti-stress relaxation resistance even was better than that of Cu–Be alloys at evaluated temperature. Microstructure observation revealed that β-Ni3Si phase precipitated in the initial stages ageing process, with further increasing the ageing time, β-Ni3Si, and δ-Ni2Si phase precipitates appeared and contributed to the ultrahigh strength by Orowan strengthening. The satellites spots around diffraction spots of Cu matrix symmetrically in 112Cu zone crystal axis have been determined, resulting that satellites spots are from the electron diffraction of δ-Ni2Si precipitates. The crystal orientation relationship between matrix and precipitates is that: (111¯)cu//(111¯)β//(02¯1)δ;112cu//112β//012δ.
The tensile strength, yield strength and elongation of designed alloy are 1090 MPa, 940 MPa and 3.5%, respectively. Display omitted
TiN nanoparticle reinforced AlSi10Mg composite powder was produced by a novel ultrasonic vibration dispersion technique. The TiN/AlSi10Mg composites were fabricated via selective laser melting (SLM). ...The effects of scanning speed on the microstructure, particle distribution state, and tribological properties of the as-built composites were studied. Experimental results showed a better SLM processibility for the composite powder due to the considerable improvement of laser absorption capacity. The microstructure of as-built composite parts was remarkably refined with a gradually decreased average grain size from 0.388 μm to 0.284 μm by increasing scanning speed compared to that of AlSi10Mg part (∼ 0.579 μm). Nano-sized TiN particles were evenly distributed and well-bonded in the composite matrix while minimized agglomerated TiN particles gathered and grew into large spherical clusters. Because of the in-situ reaction occurred between TiN cluster and AlSi10Mg matrix, novel graded interfacial layers were observed. The mean layer thickness increased from 0.11 μm to 0.38 μm by decreasing the scanning speed from 600 mm/s to 200 mm/s. Taking advantage of the dispersion strengthening, fine grain strengthening, and the graded interfacial layer, a considerably-high microhardness (145 ± 4.9 HV), and enhanced wear performance were achieved.
At steady state, the NOD-like receptor (NLR)-containing pyrin domain (PYD) (NLRP)1 inflammasome is maintained in an auto-inhibitory complex by dipeptidyl peptidases 8 and 9 (DPP8 and DPP9) and is ...activated by pathogen-encoded proteases after infection. Here, we showed that the open reading frame (ORF)45 protein of the Kaposi's sarcoma-associated herpesvirus activated the human NLRP1 (hNLRP1) inflammasome in a non-protease-dependent manner, and we additionally showed that the Linker1 region of hNLRP1, situated between the PYD and NACHT domains, was required for the auto-inhibition and non-protease-dependent activation of hNLRP1. At steady state, the interaction between Linker1 and the UPA subdomain silenced the activation of hNLRP1 in auto-inhibitory complexes either containing DPP9 or not in a manner independent of DPP9. ORF45 binding to Linker1 displaced UPA from the Linker1-UPA complex and induced the release of the C-terminal domain of hNLRP1 for inflammasome assembly. The ORF45-dependent activation of the NLRP1 inflammasome was conserved in primates but was not observed for murine NLRP1b inflammasomes.
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