470 research outputs found
Clustering of cardiovascular disease biological risk factors among older adults in Shenzhen City, China: A cross-sectional study
Objectives Few studies reported the clustering of cardiovascular disease (CVD) biological risk factors among older adults. The objective of this study was to characterise the clustering of CVD biological risk factors among adults aged 65 or older in Shenzhen city, China. Design Cross-sectional study. Setting General communities in Shenzhen, Guangdong, China. Participants A representative sample of 5635 participants aged 65 or older participated in the survey with a response rate of 93.6%. Main outcome measures Individual CVD biological risk factors (overweight/obesity, central obesity, hypertension, dyslipidaemia and diabetes) and their clustering. Results The prevalence of overweight, obesity, central obesity, hypertension, dyslipidaemia and diabetes in this study was 37.4%, 10.8%, 37.0%, 51.9%, 40.2% and 18.0%, respectively. The mean count of CVD biological risk factors per participant was 1.95. The 86.0% of the participants presented at least one CVD biological risk factor and 33.8% of the participants presented clustering of CVD biological risk factors, that is, presenting three or more CVD biological risk factors, as defined in this study. Multivariable logistic regression analysis showed that gender, age, and drinking and smoking status were significantly associated with clustering of CVD biological risk factors (P<0.05). Women, the older and alcohol drinkers were more likely to have clustering of CVD biological risk factors. Conclusions The prevalence of CVD biological risk factors is fairly high in the older adults with a tendency of clustering in Shenzhen. The findings highlight the need for integrated management of CVD biological risk factors among older adults
Observation of Weyl nodes in TaAs
In 1929, H. Weyl proposed that the massless solution of Dirac equation
represents a pair of new type particles, the so-called Weyl fermions [1].
However the existence of them in particle physics remains elusive for more than
eight decades. Recently, significant advances in both topological insulators
and topological semimetals have provided an alternative way to realize Weyl
fermions in condensed matter as an emergent phenomenon: when two non-degenerate
bands in the three-dimensional momentum space cross in the vicinity of Fermi
energy (called as Weyl nodes), the low energy excitation behaves exactly the
same as Weyl fermions. Here, by performing soft x-ray angle-resolved
photoemission spectroscopy measurements which mainly probe bulk band structure,
we directly observe the long-sought-after Weyl nodes for the first time in
TaAs, whose projected locations on the (001) surface match well to the Fermi
arcs, providing undisputable experimental evidence of existence of Weyl fermion
quasiparticles in TaAs.Comment: 10 pages, 4 figures, see also related papers on TaAs
arXiv:1501.00060, arXiv:1502.0468
Electrospun icariin-loaded core-shell collagen, polycaprolactone, hydroxyapatite composite scaffolds for the repair of rabbit tibia bone defects
Background: Electrospinning is a widely used technology that can produce scaffolds with high porosity and surface area for bone regeneration. However, the small pore sizes in electrospun scaffolds constrain cell growth and tissue-ingrowth. In this study, novel drug-loading core-shell scaffolds were fabricated via electrospinning and freeze drying to facilitate the repair of tibia bone defects in rabbit models.
Materials and Methods: The collagen core scaffolds were freeze-dried containing icariin (ICA)-loaded chitosan microspheres. The shell scaffolds were electrospun using collagen, polycaprolactone and hydroxyapatite materials to form CPH composite scaffolds with the ones containing ICA microspheres named CPHI. The core-shell scaffolds were then cross-linked by genipin. The morphology, microstructure, physical and mechanical properties of the scaffolds were assessed. Rat marrow mesenchymal stem cells from the wistar rat were cultured with the scaffolds. The cell adhesion and proliferation were analysed. Adult rabbit models with tibial plateau defects were used to evaluate the performance of these scaffolds in repairing the bone defects over 4 to 12 weeks.
Results: The results reveal that the novel drug-loading core-shell scaffolds were successfully fabricated, which showed good physical and chemical properties and appropriate mechanical properties. Furthermore, excellent cells attachment was observed on the CPHI scaffolds. The results from radiography, micro-computed tomography, histological and immunohistochemical analysis demonstrated that abundant new bones were formed on the CPHI scaffolds.
Conclusion: These new core-shell composite scaffolds have great potential for bone tissue engineering applications and may lead to effective bone regeneration and repair
Experimental discovery of Weyl semimetal TaAs
Weyl semimetals are a class of materials that can be regarded as
three-dimensional analogs of graphene breaking time reversal or inversion
symmetry. Electrons in a Weyl semimetal behave as Weyl fermions, which have
many exotic properties, such as chiral anomaly and magnetic monopoles in the
crystal momentum space. The surface state of a Weyl semimetal displays pairs of
entangled Fermi arcs at two opposite surfaces. However, the existence of Weyl
semimetals has not yet been proved experimentally. Here we report the
experimental realization of a Weyl semimetal in TaAs by observing Fermi arcs
formed by its surface states using angle-resolved photoemission spectroscopy.
Our first-principles calculations, matching remarkably well with the
experimental results, further confirm that TaAs is a Weyl semimetal.Comment: 14 pages, 4 figures, see also theoretical paper on TaAs
arXiv:1501.0006
Raman Signatures of Broken Inversion Symmetry and In-plane Anisotropy in Type-II Weyl Semimetal Candidate TaIrTe4
The layered ternary compound TaIrTe4 is an important candidate to host the
recently predicted type-II Weyl Fermions. However, a direct and definitive
proof of the absence of inversion symmetry in this material, a prerequisite for
the existence of Weyl Fermions, has so far remained evasive. Herein, an
unambiguous identification of the broken inversion symmetry in TaIrTe4 is
established using angle-resolved polarized Raman spectroscopy. Combining with
high-resolution transmission electron microscopy, we demonstrate an efficient
and nondestructive recipe to determine the exact crystallographic orientation
of TaIrTe4 crystals. Such technique could be extended to the fast
identification and characterization of other type-II Weyl Fermions candidates.
A surprisingly strong in-plane electrical anisotropy in TaIrTe4 thin flakes is
also revealed, up to 200% at 10K, which is the strongest known electrical
anisotropy for materials with comparable carrier density, notably in such good
metals as copper and silver
Corrigendum to “A novel anti-atherosclerotic mechanism of quercetin: Competitive binding to KEAP1 via Arg483 to inhibit macrophage pyroptosis” [Redox Biol. 57 (2022) 102511](S221323172200283X)(10.1016/j.redox.2022.102511)
The authors mistakenly placed Fig. 3H which is the same as Fig. 2I, the quantization diagram for Fig. 2H, and there is no quantization data for Fig. 3G in the present article. Therefore, we request a correction to Fig. 3H to avoid misleading the readers. The correct figure is attached here. All the authors agreed on the correction. We apologize for the mistake
Genetic diversity and population structure of cucumber (Cucumis sativus L.)
Knowing the extent and structure of genetic variation in germplasm collections is essential for the conservation and utilization of biodiversity in cultivated plants. Cucumber is the fourth most important vegetable crop worldwide and is a model system for other Cucurbitaceae, a family that also includes melon, watermelon, pumpkin and squash. Previous isozyme studies revealed a low genetic diversity in cucumber, but detailed insights into the crop's genetic structure and diversity are largely missing. We have fingerprinted 3,342 accessions from the Chinese, Dutch and U.S. cucumber collections with 23 highly polymorphic Simple Sequence Repeat (SSR) markers evenly distributed in the genome. The data reveal three distinct populations, largely corresponding to three geographic regions. Population 1 corresponds to germplasm from China, except for the unique semi-wild landraces found in Xishuangbanna in Southwest China and East Asia; population 2 to Europe, America, and Central and West Asia; and population 3 to India and Xishuangbanna. Admixtures were also detected, reflecting hybridization and migration events between the populations. The genetic background of the Indian germplasm is heterogeneous, indicating that the Indian cucumbers maintain a large proportion of the genetic diversity and that only a small fraction was introduced to other parts of the world. Subsequently, we defined a core collection consisting of 115 accessions and capturing over 77% of the SSR alleles. Insight into the genetic structure of cucumber will help developing appropriate conservation strategies and provides a basis for population-level genome sequencing in cucumber
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