2,030 research outputs found
Regenerating plants from in vitro culture of Erigeron breviscapus leaves
A protocol to efficiently achieve plant regeneration from leaf explants of Erigeron breviscapus (Compositae) has been developed. Leaf explants produced calli on Murashige and Skoog’s (1962) basal medium (MS) supplemented with 6-benzylaminopurine (BAP) (0.4 mM) and 2,4-dichlorophenoxyacetic acid (2,4-D) (0.4-22.6 mM) under a 16-h photoperiod. Direct adventitious shoots were induced from leaf explants on MS medium containing BAP (22.2 mM) and IAA (5.7 mM) under the light treatment. The effect of the dark incubation on shoot regeneration from leaves indicated that 15 days of darkness permitted a higher regeneration frequency (82.6%) on the medium supplemented with BAP (4.4 mM) and indole-3- acetic acid (IAA) (0.6 mM). Regenerated shoots were rooted on MS medium with or without naphthaleneacetic acid (NAA). Plantlets were cultivatable in the greenhouse after acclimatization
Effects of Qigong Exercise on Fatigue, Anxiety, and Depressive Symptoms of Patients with Chronic Fatigue Syndrome-Like Illness: A Randomized Controlled Trial
published_or_final_versio
Novel SNPs polymorphism of bovine CACNA2D1 gene and their association with somatic cell score
Mastitis is a major cause of economic loss in dairy cattle. In this study, the bovine CACNA2D1 gene was taken as a candidate gene for mastitis resistance. The objective of this study was to identify single nucleotide polymorphisms (SNPs) in the bovine CACNA2D1 gene and evaluate the association of these SNPs with mastitis in cattle. Through DNA sequencing and PCR-RFLP analysis, three mutations C367400T, A496561G and G519663A were detected in the cattle CACNA2D1 gene. Altogether 240 dairy cattle of three breeds (Holstein, Simmental, and Sanhe cattle) were genotyped and allele frequencies were determined. The effects of CACNA2D1 polymorphisms on somatic cell score (SCS) were analyzed and a significant association was found between G519663A and SCS. The mean of genotype GG was significantly lower than those of genotypes AG and AA. The results of this research will be useful in further studies to determine the role of the CACNA2D1 gene in mastitis resistance and further work will be necessary to investigate whether the CACNA2D1 gene play a role in defending the host from mastitis.Key words: Association analysis, CACNA2D1 gene, dairy breeds, mastitis, somatic cell score
Drivers of methicillin-resistant Staphylococcus aureus (MRSA) lineage replacement in China
BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) is a major nosocomial pathogen subdivided into lineages termed sequence types (STs). Since the 1950s, successive waves of STs have appeared and replaced previously dominant lineages. One such event has been occurring in China since 2013, with community-associated (CA-MRSA) strains including ST59 largely replacing the previously dominant healthcare-associated (HA-MRSA) ST239. We previously showed that ST59 isolates tend to have a competitive advantage in growth experiments against ST239. However, the underlying genomic and phenotypic drivers of this replacement event are unclear. METHODS: Here, we investigated the replacement of ST239 using whole-genome sequencing data from 204 ST239 and ST59 isolates collected in Chinese hospitals between 1994 and 2016. We reconstructed the evolutionary history of each ST and considered two non-mutually exclusive hypotheses for ST59 replacing ST239: antimicrobial resistance (AMR) profile and/or ability to colonise and persist in the environment through biofilm formation. We also investigated the differences in cytolytic activity, linked to higher virulence, between STs. We performed an association study using the presence and absence of accessory virulence genes. RESULTS: ST59 isolates carried fewer AMR genes than ST239 and showed no evidence of evolving towards higher AMR. Biofilm production was marginally higher in ST59 overall, though this effect was not consistent across sub-lineages so is unlikely to be a sole driver of replacement. Consistent with previous observations of higher virulence in CA-MRSA STs, we observed that ST59 isolates exhibit significantly higher cytolytic activity than ST239 isolates, despite carrying on average fewer putative virulence genes. Our association study identified the chemotaxis inhibitory protein (chp) as a strong candidate for involvement in the increased virulence potential of ST59. We experimentally validated the role of chp in increasing the virulence potential of ST59 by creating Δchp knockout mutants, confirming that ST59 can carry chp without a measurable impact on fitness. CONCLUSIONS: Our results suggest that the ongoing replacement of ST239 by ST59 in China is not associated to higher AMR carriage or biofilm production. However, the increase in ST59 prevalence is concerning since it is linked to a higher potential for virulence, aided by the carriage of the chp gene
New progress in LURR-integrating with the dimensional method
The evolution laws of LURR (Loading-Unloading Response Ratio) before strong earthquakes, especially the peak point of LURR, are described in this paper. The results of four methods (experimental, numerical simulation, seismic data analysis and with damage mechanics analysis) lead to a consistent conclusion-the evolution laws of LURR before strong earthquakes are that, at the early stage of the seismic cycle, LURR will fluctuate around 1 and in the late stage, it rises swiftly and to its peak point. At some time after this peak point, a catastrophic event or events occur. These do not occur at the peak point, but lag behind. The lag time which is denoted by T (2) depends on the magnitude M of the upcoming earthquake among other factors. In order to consider the influence of geophysical parameters in a specific region such as E (a) and J ((t)), where is the shear strain rate of tectonic loading in situ, E (a) is the sum of radiated energy of all earthquake occurring in a specific region measured during a long time duration (110 years in this paper) divided by the area of the region and the time duration, and J ((t)) is a parameter denoting the LURR anomaly area weighted with Y (the value of LURR) and represents the expanse and degree of the seismogenic zone. The dimensional analysis method has been used to reveal the relation between M, T (2) and other parameters in situ for more reliable earthquake prediction
Self-Assembled 3D Flower-Like Hierarchical β-Ni(OH)2Hollow Architectures and their In Situ Thermal Conversion to NiO
Three-dimensional (3D) flower-like hierarchicalβ-Ni(OH)2hollow architectures were synthesized by a facile hydrothermal route. The as-obtained products were well characterized by XRD, SEM, TEM (HRTEM), SAED, and DSC-TGA. It was shown that the 3D flower-like hierarchicalβ-Ni(OH)2hollow architectures with a diameter of several micrometers are assembled from nanosheets with a thickness of 10–20 nm and a width of 0.5–2.5 μm. A rational mechanism of formation was proposed on the basis of a range of contrasting experiments. 3D flower-like hierarchical NiO hollow architectures with porous structure were obtained after thermal decomposition at appropriate temperatures. UV–Vis spectra reveal that the band gap of the as-synthesized NiO samples was about 3.57 eV, exhibiting obviously red shift compared with the bulk counterpart
Probing host pathogen cross-talk by transcriptional profiling of both Mycobacterium tuberculosis and infected human dendritic cells and macrophages
This study provides the proof of principle that probing the host and the microbe transcriptomes simultaneously is a valuable means to accessing unique information on host pathogen interactions. Our results also underline the extraordinary plasticity of host cell and pathogen responses to infection, and provide a solid framework to further understand the complex mechanisms involved in immunity to M. tuberculosis and in mycobacterial adaptation to different intracellular environments
Effect of the H1N1 Influenza Pandemic on the Incidence of Epidemic Keratoconjunctivitis and on Hygiene Behavior: A Cross-Sectional Study
Background: EKC is transmitted chiefly by direct hand contact. It is suspected that the 2009/2010 influenza pandemic influenced hand washing. This study aims to examine the relationship between the 2009/2010 H1N1 influenza pandemic and hygiene behavior. Methods: We compared the EKC prevalence trends before, during and after the 2009/2010 influenza pandemic by using a t-test comparison of EKC sentinel surveillance. Results: During the pre-pandemic period, the incidence of EKC increased from the 21st to the 44th week each year. However, during the pandemic period in 2009, there was no epidemic peak. In the post-pandemic period, the epidemic curve was similar to that in the pre-pandemic period. Compared to the pre-pandemic period, the total number of EKC patients during the pandemic period showed a decrease of 44.9 % (t value = 27.23, p = 0.002). Comparing the pre-pandemic and pandemic periods by age group, we found there to be a significant decrease in the number of EKC patients for all age groups (24.12#t value#27.23, all P,0.05). This finding was most evident in the teenage group (62%) compared to the other age groups (decreases of 29 to 44%). Conclusions: A continuing effort should be made to educate the public on basic infection prevention behaviors in th
Differences in carotid arterial morphology and composition between individuals with and without obstructive coronary artery disease: A cardiovascular magnetic resonance study
Objective: We sought to determine differences with cardiovascular magnetic resonance (CMR) in the morphology and composition of the carotid arteries between individuals with angiographically-defined obstructive coronary artery disease (CAD, = 50% stenosis, cases) and
those with angiographically normal coronaries (no lumen irregularities, controls).
Methods and results: 191 participants (50.3% female; 50.8% CAD cases) were imaged with a multi-sequence, carotid CMR protocol at 1.5T. For each segment of the carotid, lumen area, wall area, total vessel area (lumen area + wall area), mean wall thickness and the presence or absence
of calcification and lipid-rich necrotic core were recorded bilaterally. In male CAD cases compared to male controls, the distal bulb had a significantly smaller lumen area (60.0 [plus or minus] 3.1 vs. 79.7 [plus or minus] 3.2 mm[super]2, p less than 0.001) and total vessel area (99.6 [plus or minus] 4.0 vs. 119.8 [plus or minus] 4.1 mm[super]2; p less than 0.001), and larger mean wall thickness (1.25 [plus or minus] 0.03 vs. 1.11 [plus or minus] 0.03 mm; p = 0.002). Similarly, the internal carotid had a smaller lumen area (37.5 [plus or minus] 1.8 vs. 44.6 [plus or minus] 1.8 mm[super]2; p = 0.006) and smaller total vessel area (64.0 [plus or minus] 2.3 vs. 70.9 [plus or minus] 2.4 mm[super]2; p = 0.04). These metrics were not significantly different between female
groups in the distal bulb and internal carotid or for either gender in the common carotid. Male CAD cases had an increased prevalence of lipid-rich necrotic core (49.0% vs. 19.6%; p = 0.003), while calcification was more prevalent in both male (46.9% vs. 17.4%; p = 0.002) and female (33.3% vs. 14.6%; p = 0.031) CAD cases compared to controls.
Conclusion: Males with obstructive CAD compared to male controls had carotid bulbs and internal carotid arteries with smaller total vessel and lumen areas, and an increased prevalence of lipid-rich necrotic core. Carotid calcification was related to CAD status in both males and females. Carotid CMR identifies distinct morphological and compositional differences in the carotid arteries
between individuals with and without angiographically-defined obstructive CAD.Carotid Atherosclerosis (MRI) Progression Study (CAMPS, HL076378) and Cardiovascular Research Training Program (T-32, HL07838); and the General Clinical Research Center at the Wake Forest University School of Medicine (M01 RR-07122)
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