89 research outputs found
Engineering Biphoton Wave Packets with an Electromagnetically Induced Grating
We propose to shape biphoton wave packets with an electromagnetically induced
grating in a four-level double- cold atomic system. We show that the
induced hybrid grating plays an essential role in directing the new fields into
different angular positions, especially to the zeroth-order diffraction. A
number of interesting features appear in the shaped two-photon waveforms. For
example, broadening or narrowing the spectrum would be possible in the proposed
scheme even without the use of a cavity.Comment: Published in Physical Review A 82, 043814 (2010
Ambiguity Function Method Scheme for Aircraft Attitude Sensor Utilising GPS/GLONASS Carrier Phase Measurement
When the receivers of GPS, GLONASS, COMPASS and other such systems are equipped with multiple antennas, they can give attitude information. Based on the difference carrier phase equations established in local level frame (LLF), a new algorithm is presented to resolve aircraft attitude determination problems in real-time. Presuming that the cycle integer ambiguity is known, the measurement equations have attitude analytical resolutions using single difference (SD) equations of two navigation satellites in-view. Similar with SD process, the doubledifference (DD) measurements are established and analysed. In addition, the SD and DD algorithms are capable of reducing the integer search space into some discrete point space and then the ambiguity function method (AFM) resolves the ambiguity function within the point solutions space. Therefore the procedures have very low computation, thus saving time. The hardware architecture has been realised using multiple GPS/GLONASS OEMs. The experimental results have demonstrated that the proposed approach is effective and can satisfy the requirement of real-time application in cases of GPS, and combined GPS, and GLONASS.Defence Science Journal, 2009, 59(5), pp.466-470, DOI:http://dx.doi.org/10.14429/dsj.59.154
Hydrothermal Synthesis of Ln(OH) 3
One-dimensional rare earth oxides and hydroxides are of importance in many applications due to their rich physicochemical properties. In this work, we synthesized Ln(OH)3 (Ln = Eu, Nd, Dy) nanorods by a hydrothermal method with the assistance of n-butylamine as an alkaline resource. The porous Ln2O3 nanorods were produced through annealing the corresponding Ln(OH)3 nanorods. XRD and TEM techniques were employed to characterize the products. The annealing process and the optical properties of as-synthesized Ln2O3 are also investigated by TG and PL test. We expected that these nanomaterials could find potential applications in the future
Epidemiological characteristics and factors affecting healing in unintentional pediatric wounds
ObjectiveTo analyze the epidemiological characteristics and wound healing conditions of common unintentional skin lacerations in children.MethodsA retrospective analysis was conducted on data from 1,107 children, aged 0–12 years, with skin lacerations who received emergency treatment at Qilu Hospital of Shandong University from January 1, 2019, to December 30, 2022. Data on age, injury site, time from injury to suturing, and wound healing conditions were statistically analyzed.ResultsAmong the 1,107 cases, 714 (64.5%) were male and 393 (35.5%) were female, with a male-to-female ratio of 1.8:1; median age was 5 years (IQR, 3–7). Infants and toddlers (0–3 years old) constituted the highest proportion, accounting for 36.3% (402 cases). The number of children aged over 3 years gradually decreased with increasing age. In younger children, the most common injuries were to the forehead, scalp, and lower jaw; in school-aged children, the proportion of limb and trunk injuries significantly increased. Age (OR, 1.34; 95% CI, 1.23–1.46), outdoor injuries (OR, 2.21; 95% CI, 1.18–4.16), lower limb injuries (OR, 5.35; 95% CI, 2.86–10.00), and wound length greater than 3 cm (OR, 10.65; 95% CI, 5.02–22.60) were significant risk factors for poor wound healing. The risk of poor wound healing increased by 34% for each additional year of age.ConclusionIn children, the common sites of unintentional skin lacerations show distinct age and gender distribution characteristics. Older age, outdoor injuries, longer wound lengths, and lower limb injuries are independent risk factors for poor wound healing
The life cycle of Thelohanellus kitauei (Myxozoa: Myxosporea) infecting common carp (Cyprinus carpio) involves aurantiactinomyxon in Branchiura sowerbyi
Thelohanellus kitauei is a freshwater myxosporean parasite causing intestinal giant cystic disease of common carp. To clarify the life cycle of T. kitauei, we investigated the oligochaete populations in China and Hungary. This study confirms two distinct aurantiactinomyxon morphotypes (Aurantiactinomyxon type 1 and Aurantiactinomyxon type 2) from Branchiura sowerbyi as developmental stages of the life cycle of T. kitauei. The morphological characteristics and DNA sequences of these two types are described here. Based on 18S rDNA sequence analysis, Aurantiactinomyxon type 1 (2048 bp) and Aurantiactinomyxon type 2 (2031 bp) share 99.2–99.4 %, 99.8–100 % similarity to the published sequences of T. kitauei, respectively. The 18S rDNA sequences of these two aurantiactinomyxon morphotypes share 99.4 % similarity, suggesting intraspecific variation within the taxon, possibly due to geographic origin. Phylogenetic analyses demonstrate the two aurantiactinomyxon types clustered with T. kitauei. Regardless, based on 18S rDNA synonymy, it is likely that Aurantiactinomyxon type 1 and 2 are conspecific with T. kitauei. This is the fourth elucidated two-host life cycle of Thelohanellus species and the first record of T. kitauei in Europe
Analysis of virulence genes and antimicrobial resistance of Vibrio parahaemolyticus isolated from shellfish in 2018
Objective To analyze the virulence genes and antimicrobial resistance of 140 Vibrio parahaemolyticus strains from shellfish collected from farms and markets. Methods Virulence genes and antimicrobial resistance genes were detected by PCR amplification method, and antimicrobial resistance was determined by disk diffusion test. Results None of the 140 strains carried tdh gene, and trh gene was detected in one strain. All strains were resistant to ampicillin, some strains were resistant to cefazolin, cefuroxime sodium, streptomycin, amikacin, sulphamethoxazole/trimethoprim, tetracycline and florfenicol. All strains were sensitive to cefepime, gentamicin, imipenem, meropenem, ofloxacin and doxycycline. Six strains showed multi-antimicrobial resistance to two or more categories of antimicrobials. The resistance genes strA and strB were detected in streptomycin resistant strains, tetA was detected in tetracycline resistant strains, sul2 was detected in sulphamethoxazole/trimethoprim resistant strains, and floR was detected in florfenicol resistant strain. Conclusion Most of Vibrio parahaemolyticus strains didn't carry virulence genes and showed antimicrobial resistance to a certain extent. Some strains had more than one antimicrobial resistance gene, which exhibited multi-antimicrobial resistance. These results indicated that enhancing the monitoring of pathogenicity and antimicrobial resistance of Vibrio parahaemolyticus in aquatic products should be continued
An Integration of Genome-Wide Association Study and Gene Expression Profiling to Prioritize the Discovery of Novel Susceptibility Loci for Osteoporosis-Related Traits
Osteoporosis is a complex disorder and commonly leads to fractures in elderly persons. Genome-wide association studies (GWAS) have become an unbiased approach to identify variations in the genome that potentially affect health. However, the genetic variants identified so far only explain a small proportion of the heritability for complex traits. Due to the modest genetic effect size and inadequate power, true association signals may not be revealed based on a stringent genome-wide significance threshold. Here, we take advantage of SNP and transcript arrays and integrate GWAS and expression signature profiling relevant to the skeletal system in cellular and animal models to prioritize the discovery of novel candidate genes for osteoporosis-related traits, including bone mineral density (BMD) at the lumbar spine (LS) and femoral neck (FN), as well as geometric indices of the hip (femoral neck-shaft angle, NSA; femoral neck length, NL; and narrow-neck width, NW). A two-stage meta-analysis of GWAS from 7,633 Caucasian women and 3,657 men, revealed three novel loci associated with osteoporosis-related traits, including chromosome 1p13.2 (RAP1A, p = 3.6×10−8), 2q11.2 (TBC1D8), and 18q11.2 (OSBPL1A), and confirmed a previously reported region near TNFRSF11B/OPG gene. We also prioritized 16 suggestive genome-wide significant candidate genes based on their potential involvement in skeletal metabolism. Among them, 3 candidate genes were associated with BMD in women. Notably, 2 out of these 3 genes (GPR177, p = 2.6×10−13; SOX6, p = 6.4×10−10) associated with BMD in women have been successfully replicated in a large-scale meta-analysis of BMD, but none of the non-prioritized candidates (associated with BMD) did. Our results support the concept of our prioritization strategy. In the absence of direct biological support for identified genes, we highlighted the efficiency of subsequent functional characterization using publicly available expression profiling relevant to the skeletal system in cellular or whole animal models to prioritize candidate genes for further functional validation
Genetic determinants of heel bone properties: genome-wide association meta-analysis and replication in the GEFOS/GENOMOS consortium
Quantitative ultrasound of the heel captures heel bone properties that independently predict fracture risk and, with bone mineral density (BMD) assessed by X-ray (DXA), may be convenient alternatives for evaluating osteoporosis and fracture risk. We performed a meta-analysis of genome-wide association (GWA) studies to assess the genetic determinants of heel broadband ultrasound attenuation (BUA; n = 14 260), velocity of sound (VOS; n = 15 514) and BMD (n = 4566) in 13 discovery cohorts. Independent replication involved seven cohorts with GWA data (in silico n = 11 452) and new genotyping in 15 cohorts (de novo n = 24 902). In combined random effects, meta-analysis of the discovery and replication cohorts, nine single nucleotide polymorphisms (SNPs) had genome-wide significant (P < 5 × 10(-8)) associations with heel bone properties. Alongside SNPs within or near previously identified osteoporosis susceptibility genes including ESR1 (6q25.1: rs4869739, rs3020331, rs2982552), SPTBN1 (2p16.2: rs11898505), RSPO3 (6q22.33: rs7741021), WNT16 (7q31.31: rs2908007), DKK1 (10q21.1: rs7902708) and GPATCH1 (19q13.11: rs10416265), we identified a new locus on chromosome 11q14.2 (rs597319 close to TMEM135, a gene recently linked to osteoblastogenesis and longevity) significantly associated with both BUA and VOS (P < 8.23 × 10(-14)). In meta-analyses involving 25 cohorts with up to 14 985 fracture cases, six of 10 SNPs associated with heel bone properties at P < 5 × 10(-6) also had the expected direction of association with any fracture (P < 0.05), including three SNPs with P < 0.005: 6q22.33 (rs7741021), 7q31.31 (rs2908007) and 10q21.1 (rs7902708). In conclusion, this GWA study reveals the effect of several genes common to central DXA-derived BMD and heel ultrasound/DXA measures and points to a new genetic locus with potential implications for better understanding of osteoporosis pathophysiology
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