4,787 research outputs found

    Consolidated Chamber Design and Protocol for Olfactory Conditioning Assay with Drosophila Melanogaster

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    The olfactory conditioning assay is widely used in Alzheimer’s disease research to quantify learning and memory in Drosophila melanogaster. The assay tests ability to recall an aversive conditioned stimulus of scent paired with electrical shock when presented a choice between shock-associated and unrelated scents. The T-maze, a commonly used apparatus for olfactory conditioning assays, employs an elevator mechanism to transfer live flies from the shock-delivering training chamber to the scent selection point. This elevator mechanism is known to cause fly casualty. T-mazes are not commercially available and often difficult to reproduce. Other existing variations of olfactory conditioning apparatuses use airflow or automated machinery to transfer flies in place of the elevator. These alternative methods are known to inflict stress on flies during transfer, potentially altering conditioning effectiveness. A new, single-chamber apparatus was designed to address these concerns. The design consolidates the training chamber and scent selection point into one space, eliminating the need for transfer. The chamber features a flexible copper printed circuit board, which is powered off to convert the space to the non-shocking selection point. A multi-opening slider component provides controlled access to the chamber, streamlining fly insertion, training, testing, and removal. All structural elements are 3D printed, allowing for simple reproduction and alteration if desired. In preliminary trials, the single-chamber design displayed both minimal fly casualty and promise in functioning as a suitable alternative for traditional olfactory conditioning apparatuses

    Loss of Courtship Suppression Memory in a Drosophila melanogaster Model of Alzheimer’s Disease

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    Alzheimer’s disease (AD) is the most prevalent and lethal neurodegenerative disease. Memory loss and motor dysfunction are accompanied by pathological hallmarks like neurofibrillary tangles or amyloid plaques. In this study, courtship suppression assay was used to assess learning and memory of a transgenic Drosophila melanogaster (the fruit fly) line expressing human Amyloid beta 42 (Aβ42). At young age (4–6 days old), both parental control and AD flies displayed lower courtship indices during training after being rejected by previously mated females. However, in the subsequent testing phase, young AD flies showed compromised recall memory, unlike that of parental controls. Neither control nor AD flies at 16–18 days old showed significant learning or recall memory. AD flies also exhibited age-related motor defects and presented amyloid plaques in brain sections. Interestingly, older AD flies displayed persistent chasing throughout the one-hour training period, and they attempted copulation at higher frequency than the untrained AD controls. Thus, transgenic AD flies displayed early onset of memory deficit, and aggressive courtship behavior as they aged. This article was published Open Access through the CCU Libraries Open Access Publishing Fund. The article was first published in eBio: https://www.eaglehill.us/ebio-pdfs-regular/EBIO-009-Lin.pd

    Association of erythrocyte n-3 polyunsaturated fatty acids with incident type 2 diabetes in a Chinese population

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    Summary Background & aims The association between circulating n-3 polyunsaturated fatty acid (PUFA) biomarkers and incident type 2 diabetes in Asian populations remains unclear. We aimed to examine the association of erythrocyte n-3 PUFA with incident type 2 diabetes in a Chinese population. Methods A total of 2671 participants, aged 40–75 y, free of type 2 diabetes at baseline, were included in the present analysis. Incident type 2 diabetes cases (n = 213) were ascertained during median follow-up of 5.6 years. Baseline erythrocyte fatty acids were measured by gas chromatography. We used multivariable Cox regression models to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs) of type 2 diabetes across quartiles of erythrocyte n-3 PUFA. Results After adjustment for potential confounders, HRs (95% CIs) of type 2 diabetes were 0.68 (0.47, 1.00), 0.77 (0.52, 1.15), and 0.63 (0.41, 0.95) in quartiles 2–4 of docosapentaenoic acid (C22:5n-3) (P-trend = 0.07), compared with quartile 1; and 1.08 (0.74, 1.60), 1.03 (0.70, 1.51), and 0.57 (0.38, 0.86) for eicosapentaenoic acid (C20:5n-3) (P-trend = 0.007). No association was found for docosahexaenoic acid (C22:6n-3) or alpha-linolenic acid (C18:3n-3). Conclusions Erythrocyte n-3 PUFA from marine sources (C22:5n-3 and C20:5n-3), as biomarkers of dietary marine n-3 PUFA, were inversely associated with incident type 2 diabetes in this Chinese population. Future prospective investigations in other Asian populations are necessary to confirm our findings

    Potassium {4-[(3S,6S,9S)-3,6-dibenzyl-9-isopropyl-4,7,10-trioxo-11–oxa-2,5,8-triazadodecyl]phenyl}trifluoroborate

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    [[abstract]]The reported compound 4 was synthesized and fully characterized by 1H NMR, 13C NMR, 11B NMR, 19F NMR, and high resolution mass spectrometry.[[booktype]]電子版[[countrycodes]]CH

    The Improved Algorithm of Fast Panorama Stitching for Image Sequence and Reducing the Distortion Errors

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    The traditional image stitching result based on the SIFT feature points extraction, to a certain extent, has distortion errors. The panorama, especially, would get more seriously distorted when compositing a panoramic result using a long image sequence. To achieve the goal of creating a high-quality panorama, the improved algorithm is proposed in this paper, including altering the way of selecting the reference image and putting forward a method that can compute the transformation matrix for any image of the sequence to align with the reference image in the same coordinate space. Additionally, the improved stitching method dynamically selects the next input image based on the number of SIFT matching points. Compared with the traditional stitching process, the improved method increases the number of matching feature points and reduces SIFT feature detection area of the reference image. The experimental results show that the improved method can not only accelerate the efficiency of image stitching processing, but also reduce the panoramic distortion errors, and finally we can obtain a pleasing panoramic result

    Selection and evaluation of phosphate-solubilizing bacteria from grapevine rhizospheres for use as biofertilizers

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    Phosphate-solubilizing bacteria (PSB) have the ability to solubilize insoluble phosphorus (P) and release soluble P. Extensive research has been performed with respect to PSB isolation from the rhizospheres of various plants, but little is known about the prevalence of PSB in the grapevine rhizosphere. In this study, we aimed to isolate and identify PSB from the grapevine rhizosphere in five vineyards of Northwest China, to characterize their plant-growth-promoting (PGP) traits, evaluate the effect of stress on their phosphate-solubilizing activity (PSA), and test their ability to stimulate the growth of Vitis vinifera L. cv. Cabernet Sauvignon. From the vineyard soils, 66 PSB isolates were screened, and 10 strains with high PSA were identified by 16S rRNA sequencing. Sequence analysis revealed that these 10 strains belonged to 4 genera and 5 species: Bacillus aryabhattai, B. megaterium, Klebsiella variicola, Stenotrophomonas rhizophila, and Enterobacter aerogenes. The selected PSB strains JY17 (B. aryabhattai) and JY22 (B. aryabhattai) were positive for multiple PGP traits, including nitrogen fixation and production of indole acetic acid (IAA), siderophores, 1-aminocyclopropane-1-carboxylate (ACC) deaminase, chitinase, and protease. JY17 and JY22 showed strong PSA under stress conditions of high pH, high salt, and high temperature. Therefore, these two isolates can be used as biofertilizers in saline-alkaline soils. The inoculation with PSB significantly facilitated the growth of V. vinifera cv. Cabernet Sauvignon under greenhouse conditions. Use of these PSB as biofertilizers will increase the available P content in soils, minimize P-fertilizer application, reduce environmental pollution, and promote sustainable agriculture

    Survival Prediction of Initial Blood pH for Nontraumatic Out-of-hospital Cardiac Arrest Patients in the Emergency Department

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    SummaryBackgroundMost nontraumatic out-of-hospital cardiac arrest (NTOHCA) patients who fail in prehospital resuscitation receive continued cardiopulmonary resuscitation in the emergency department (ED). Initial blood pH, which can be assessed rapidly in the ED, was examined to see whether it is a strong survival predictor for these patients.MethodsA 1-year retrospective study included consecutive 225 NTOHCA patients at a medical center in northern Taiwan who presented through the emergency medical services system. On arrival at the ED, these patients received continued cardiopulmonary resuscitation, and their initial blood pH data were assessed.ResultsThe pH value was positively correlated with variables such as return of spontaneous circulation, witnessed arrest, short prehospital time (≤20 minutes), and survival. The best cut-off value of initial blood pH, revealed by the receiver operating characteristic curve, was 7.068. The lowest pH value of the survivors was 6.856. The results of logistic regression model analysis shows that the odds ratios of survival was 10.0 (95% confidence interval [CI], 2.1–47.7) for patients with initial blood pH ≥ 7.068, 5.3 (95% CI, 1.48–18.9) for those with nonasystole rhythm, 4.0 (95% CI, 1.1–14.8) for those with prehospital time ≤20 minutes, and 9.1 (95% CI, 2.3–35.2) for those without NaHCO3 administration during resuscitation, respectively.ConclusionA cut-off value of an initial blood pH of 7.068 can serve as a predictor for survival among NTOHCA patients. In addition, patients whose initial blood pH is lower than 6.85 in the ED may not survive until hospital discharge

    Epidemiology of acute otitis media among young children: A multiple database study in Taiwan

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    Background/PurposeAcute otitis media (AOM) is a common complication of upper respiratory tract infection (URTI) among children. The purpose of this study was to evaluate the epidemiology of AOM among young children in Taiwan, including the age incidence and seasonality by combining multiple databases.MethodsTwo country-based questionnaire survey studies had been conducted to evaluate the experience of otitis media (OM) among young children: one in 2007 and the other between 2005 and 2010. The number of OM cases (5% of population younger than 7 years) in 2005 and annual visiting rates for URTI from 2005 to 2010 obtained from the National Health Insurance Research Database of Taiwan were collected and comprised the third database. The fourth database comprised ambulatory visits of children with OM to a medical center in central Taiwan between 2005 and 2010.ResultsData from a total of 1099 questionnaires were entered into Database I in 2007, and data from 9705 questionnaires between 2005 and 2010 comprised Database II. There were 86,702 children (younger than 7 years, representing 5% of the whole population for this age group) retrieved from Database III in 2007, and 5,904 cases of OM in children between 2005 and 2010 in a hospital. In Database I, 7.46% children experienced at least one episode of AOM compared with 9.21% in Database II for children aged 5 years and younger. In Database III, 13.2% children younger than 7 years had AOM in 2005. The peak season of AOM among children was from March to May (Databases III and IV).ConclusionAOM was thought to be a very common disease among children; however, this comparative analysis showed that the overall prevalence of AOM among children younger than 5 years was only 20%, much lower than in other countries. AOM was more prevalent during the spring season, and still was similarly common after age 2 years

    Kidney outcomes with SGLT2is for type 2 diabetes patients: does background treatment with metformin or RASis matter?

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    IntroductionThere is a lack of real-world evidence regarding the impact of concomitant metformin and renin-angiotensin system inhibitors (RASis) on sodium-glucose cotransporter-2 inhibitor (SGLT2i)-associated kidney outcomes. This study was aimed to investigate whether SGLT2i-associated kidney outcomes were modified by the concomitant use of metformin or RASis in patients with type 2 diabetes.MethodsSGLT2i users were identified from three electronic health record databases during May 2016 and December 2017 and categorized into those with and without concomitant use of metformin or RASis. Propensity score matching was performed to minimize baseline differences between groups. Study outcomes were mean estimated glomerular filtration rate (eGFR) change and time to 30%, 40%, and 50% eGFR reductions. A meta-analysis was performed to combine the estimates across databases.ResultsAfter matching, there were 6,625 and 3,260 SGLT2i users with and without metformin, and 6,654 and 2,746 SGLT2i users with and without RASis, respectively. The eGFR dip was similar in SGLT2i users with and without metformin therapy, but was greater in SGLT2i users with RASis compared to those without RASis. Neither metformin nor RASi use had a significant effect on SGLT2i-associated eGFR reductions, as evidenced by the hazard ratios (95% CIs) of 30% eGFR reductions for SGLT2is with versus without metformin/RASis, namely 1.02 (0.87–1.20)/1.09 (0.92–1.31). Such findings were also observed in the outcomes of 40% and 50% eGFR reductions.ConclusionUsing metformin or RASis did not modify SGLT2i-associated kidney outcomes in type 2 diabetes
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