2,677 research outputs found

    Role and significance of total phenols during rooting of Protea cynaroides L. cuttings

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    Phenolic compounds, which are known to regulate root formation, are found abundantly in difficult-toroot Protea cynaroides stem cuttings. In this study, analysis of total phenol content was carried out on blanched and unblanched cuttings to observe its fluctuation throughout the entire rooting period (120 days) and establish its relationship with root formation. Results showed that blanching significantly increased the total phenol content in the basal ends of the cuttings. The high total phenol content was associated with significantly higher rooting percentage and increased the number of roots formed. Blanching reduced the time needed for the cuttings to root sufficiently to be transplanted to the field by 30 days. Analyses of different parts of cuttings throughout the entire rooting period showed continuous increase in total phenols at the basal end, while decrease in total phenols was observed in the leaves.Keywords: Etiolation, king protea, phenolic compounds, Proteaceae, root formatio

    Studies of electronic structure of ZnO grain boundary and its proximity by using spatially resolved electron energy loss spectroscopy

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    Author name used in this publication: J. Y. Dai2002-2003 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

    Association between two CHRNA3 variants and susceptibility of lung cancer: a meta-analysis

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    Cell geometry across the ring structure of Sitka spruce.

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    For wood to be used to its full potential as an engineering material, it is necessary to quantify links between its cell geometry and the properties it exhibits at bulk scale. Doing so will make it possible to predict timber properties crucial to engineering, such as mechanical strength and stiffness, and the resistance to fluid flow, and to inform strategies to improve those properties as required, as well as to measure the effects of interventions such as genetic manipulation and chemical modification. Strength, stiffness and permeability of timber all derive from the geometry of its cells, and yet current practice is to predict them based on properties, such as bulk density, that do not directly describe the cell structure. This work explores links between micro-computed tomography data for structural-size pieces of wood, which show the variation of porosity across the wood's ring structure, and high-resolution tomography showing the geometry of the cells, from which we measure cell length, lumen area, porosity, cell wall thickness and the number density of cells. High-resolution scans, while informative, are time-consuming and expensive to run on a large number of samples at the scale of building components. By scanning the same volume of timber at both low and high resolutions (high-resolution scans over a near-continuous volume of timber of approx. 20 mm3 at 15 Ī¼m3 per voxel), we are able to demonstrate correlations between the measurements at the two different resolutions, reveal the physical basis for these correlations, and demonstrate that the data from the low-resolution scan can be used to estimate the variation in (small-scale) cell geometry throughout a structural-size piece of wood.This work was funded in major part by a Leverhulme Trust Programme Grant. The X-ray imaging work was supported by the Advanced Imaging of Materials (AIM) facility (EPSRC Grant No. EP/M028267/1), the European Social Fund (ESF) through the European Unionā€™s Convergence programme administered by the Welsh Government

    Evolutionarily Optimized Electromagnetic Sensor Measurements for Robust Surgical Navigation

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    Ā© 2001-2012 IEEE. Miniaturized electromagnetic sensors are increasingly introduced to navigate surgical instruments to anatomical targets during minimally invasive procedures, such as endoscopic surgery. These sensors are usually attached at the distal tips of surgical instruments to track their three-dimensional motion represented by the position and orientation in six degrees of freedom. Unfortunately, these sensors suffer from inaccurate measurements and jitter errors due to the patient movement (e.g., respiratory motion) and magnetic field distortion. This paper proposes an evolutionary computing strategy to optimize the sensor measurements and improve the tracking accuracy of surgical navigation. We modified two evolutionary computation algorithms and proposed adaptive particle swarm optimization (APSO) and observation-boosted differential evolution (OBDE) to enhance the navigation accuracy. The experimental results demonstrate that our modified algorithms to evolutionarily optimize electromagnetic sensor measurements can critically reduce the tracking error from 4.8 to 2.9 mm. In particular, OBDE outperforms APSO for electromagnetic endoscopic navigation

    Correlation Between Anesthesia Methods and Adverse Short-Term Postoperative Outcomes Depending on Frailty: A Prospective Cohort Study

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    Yan Feng,* Jia-Feng Sun,* Hai-Chao Wei,* Ying Cao, Lei Yao, Bo-Xiang Du The Affiliated Hospital 2 of Nantong University, Nantong City, Jiangsu Province, Peopleā€™s Republic of China*These authors contributed equally to this workCorrespondence: Bo-Xiang Du; Lei Yao, Email [email protected]; [email protected]: This study aims to investigate how the type of anesthesia used during major orthopedic surgery may impact adverse short-term postoperative outcomes depending on frailty.Methods: To conduct this investigation, we recruited individuals aged 65 years and older who underwent major orthopedic surgery between March 2022 and April 2023 at a single institution. We utilized the FRAIL scale to evaluate frailty. The primary focus was on occurrences of death or the inability to walk 60 days after the surgery. Secondary measures included death within 60 days; inability to walk without human assistance at 60 days; death or the inability to walk without human assistance at 30 days after surgery, the first time out of bed after surgery, postoperative blood transfusion, length of hospital stay, hospital costs, and the occurrence of surgical complications such as dislocation, periprosthetic fracture, infection, reoperation, wound complications/hematoma.Results: In a study of 387 old adult patients who had undergone major orthopedic surgery, 41.3% were found to be in a frail state. Among these patients, 262 had general anesthesia and 125 had neuraxial anesthesia. Multifactorial logistic regression analyses showed that anesthesia type was not linked to complications. Instead, frailty (OR 4.04, 95% CI 1.04 to 8.57, P 0.05).Conclusion: In different frail populations, neuraxial anesthesia is likely to be comparable to general anesthesia in terms of the incidence of short-term postoperative adverse outcomes.Keywords: anesthesia, frailty, major orthopedic surgery, death, impaired walking abilit

    Dental and prosthodontic status of an over 40 year-old population in Shandong Province, China

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    Contains fulltext : 97791.pdf (postprint version ) (Open Access)BACKGROUND: This study aims to (1) describe the dental status using DMFT for the whole dentition and the anterior, premolar and molar regions; (2) determine associations of demographic variables and socio-economic status (SES) with DMFT and tooth replacement; (3) analyze to what extent the goal as proposed by the WHO -'the retention of not less than 20 teeth throughout life' is achieved. METHODS: DMFT and tooth replacement data of 1588 subjects over 40 years from urban and rural sites in Qingdao (Shandong Province, China) were collected. Relative D, M, and F scores per dental region were calculated and compared by paired T-tests. Multivariable logistic regression was used to determine relationships with age, gender, place of residence, and SES. RESULTS: Mean numbers of D and F were low (1.36 respectively 0.27) at all ages. Molars had highest chance for D and M. For the molar region every additional year of age gave significantly lower chance for D and higher chance for M (OR: 0.98 and 1.02 respectively; both p </= 0.01). Mean number of M was associated with age (approximately 1.5 in each jaw at 40 years and 6 at 80 years). Females had higher chance for D (OR: 1.34; p </= 0.05) and F (OR: 1.69; p </= 0.01), and lower chance for M (OR: 0.60; p </= 0.01). Urban and rural subjects had similar chance for D; urban subjects had approximately 5 times more chance for F (p </= 0.01). SES had no relationship with D and M, however SES low was associated with F (OR: 0.45; p </= 0.01). Replacements were significantly associated with age (all dental regions except anterior region), gender (all dental regions), place of residence (whole dentition and molar region), and SES (whole dentition and premolar and molar regions). CONCLUSIONS: The majority of subjects presented a reduced dentition. Molars were most frequently affected by D and M. D, M, F and replaced teeth were associated with the background variables, however differently for different dental regions. Above the age of 70 years, only 64% of the subjects presented 'not less than 20 natural teeth'

    Boron carbide amorphous solid with tunable band gap

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    Boron carbide BxC (x = 1/6 āˆ’ 10) powders were synthesized through a microwave-assisted carbothermic reduction reaction as a potential clean energy material. Their crystallographic structures and optical properties were characterized. X-ray diffraction and electron diffraction indicated that the synthesized BxC powders were amorphous. Electron energy-loss spectroscopy demonstrated that the composition of boron and carbon was in amorphous materials, and their chemical bonding were disclosed from Raman scattering spectroscopy. UVā€“vis absorption spectroscopy indicated that the bandgap of the bulks varied from 2.30eV to 3.90eV, tuned by the boron/carbon element ratio. The synthesized powders were potential photovoltaic materials. A short-range ordering model was established to explain the optical properties
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