190 research outputs found

    Effect of ionizing (gamma) and non-ionizing (UV) radiation on the development of Trichogramma euproctidis (Hymenoptera: Trichogrammatidae)

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    The potential of using gamma and ultraviolet radiation as an alternative treatment to increase the efficiency of Trichogramma euproctidis (Girault 1911) (Hymenoptera: Trichogrammatidae) was investigated in the laboratory. The developmental and adult stages of T. euproctidis were exposed to gamma radiation of different doses (0-30 Gy) and ultraviolet radiation of 254 nm wavelengths (UV-C) for different durations (0-10 min) to assess their effect on each of the instars and their potential in breaking the developmental cycle of the egg parasitoid. The LD50 values for eggs, prepupae, pupae and adults were 8.1, 10.0, 22.7 and 9.5 Gy for gamma radiation and 9.5, 0.12, 2.0 and 11.9 min for UV radiation, respectively. The pupa and adult stages were more radioresistant to both gamma and UV radiation. The most interesting and unexpected result obtained for the prepupal stage was that UV radiation has a greater effect on prepupal stages than gamma radiation

    Effects of opening roller speed on the fiber and yarn properties in open-end friction spinning

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    The opening roller system for fiber separation in an open end spinning process is known to cause considerable fiber breakage. We have investigated fiber breakage at different opening roller speeds and the relationship between breakage and the properties of friction spun yams made from cotton, polyester, viscose, and acrylic fibers. A high level of fiber damage caused by the opening rollers occurs at high speeds. The level of damage differs from one sort of material to another. There is a great deterioration in properties when yams are processed at high opening roller speeds

    The intensity of physical activity improves cognitive performance among aging Americans

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    Background: Currently there is no pharmacological cure for Alzheimer’s disease and related dementias, physical activity (PA) has emerged as a promising approach. The optimal intensity of PA to improve cognitive health remains unknown. Therefore, this study aimed to evaluate associations between different durations and intensities of PA on performance across cognitive domains (executive function, processing speed, and memory) among aging Americans. Methods: 2377 adults aged ≥ 60 years from the cross-sectional National Health and Nutrition Examination Survey 2011-2014, were included. Linear regression in hierarchical blocks and the size of effect (η2) were analyzed with R software. Results: The mean age was 69.3±6.73, 50.86% females. Despite the attenuation of association following adjustments for covariates, participants who engaged in 3-6 hr/wk of vigorous- and \u3e 1 hr/wk of moderate-intensity PA performed significantly higher in executive function and processing speed tests compared to inactive peers (η2= 0.005 & 0.007 respectively, p \u3c 0.05). However, there was no clear dose-response relationship between the executive function and processing speed test scores and duration of weekly moderate-intensity PA. For the adjusted model, the effects of 1-3 hr/wk of vigorous-intensity PA became trivial for the delayed recall memory test scores (β=0.33; 95% CI: -0.01, 0.67; η2=0.002; p=0.56). Interestingly, higher handgrip strength and higher late-life body-mass-index were associated with a higher performance across all cognitive domains. Conclusion: Observed associations provide evidence linking habitual PA with superior cognition health among older adults. Furthermore, increased muscle strength and higher late-life adiposity may impact cognition and require further investigation

    Relationship Between Cognitive Performance, Physical Activity, and Socio-Demographic/Individual Characteristics Among Aging Americans

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    Background: Physical activity (PA) has emerged as a promising approach to delay Alzheimer’s disease and related dementias, but the optimal intensity of PA to improve cognitive health remains unknown. Objective: To evaluate the association between duration and intensity of PA and cognitive domains (executive function, processing speed, and memory) in aging Americans. Methods: Linear regressions in hierarchical blocks for variable adjustment and the size of effect (η2) were analyzed by using the data of 2,377 adults (age = 69.3±6.7 years) from the NHANES 2011–2014. Results: Participants with 3–6 h/week of vigorous- and \u3e 1 h/week of moderate-intensity PA scored significantly higher in executive function and processing speed domains of cognition compared to inactive peers (η2 = 0.005 & 0.007 respectively, p \u3c 0.05). After adjustment, the beneficial effects of 1–3 h /week of vigorous-intensity PA became trivial for delayed recall memory domain test scores (η2 = 0.33; 95%CI: –0.01,0.67; η2 = 0.002; p = 0.56). There was no linear dose-response relationship between the cognitive test scores and weekly moderate-intensity of PA. Interestingly, higher handgrip strength and higher late-life body mass index were associated with a higher performance across all cognitive domains. Conclusion: Our study supports habitual PA with superior cognition health in some but not all domains among older adults. Furthermore, increased muscle strength and higher late-life adiposity may also impact cognition

    Spin-selective electron transmission through self-assembled monolayers of double-stranded peptide nucleic acid

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    Monolayers of chiral molecules can preferentially transmit electrons with a specific spin orientation, introducing chiral molecules as efficient spin filters. This phenomenon is established as chirality-induced spin selectivity (CISS) and was demonstrated directly for the first time in self-assembled monolayers (SAMs) of double-stranded DNA (dsDNA)1. Here, we discuss SAMs of double-stranded peptide nucleic acid (dsPNA) as a system which allows for systematic investigations of the influence of various molecular properties on CISS. In photoemission studies, SAMs of chiral, γ-modified PNA show significant spin filtering of up to P = (24.4 ± 4.3)% spin polarization. The polarization values found in PNA lacking chiral monomers are considerably lower at about P = 12%. The results confirm that the preferred spin orientation is directly linked to the molecular handedness and indicate that the spin filtering capacity of the dsPNA helices might be enhanced by introduction of chiral centers in the constituting peptide monomers

    Clinical results of carotid artery stenting versus carotid endarterectomy

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    Objective: To review our results of carotid artery stenting (CAS) and carotid endarterectomy (CEA). Methods: We evaluated the medical records of patients undergoing carotid artery revascularization procedure, between 2001 and 2013 in Baskent University Hospital, Ankara, Turkey. Carotid artery stenting or CEA procedures were performed in patients with asymptomatic carotid stenosis (=70%) or symptomatic stenosis (=50%). Demographic data, procedural details, and clinical outcomes were recorded. Primary outcome measures were in 30-day stroke/transient ischemic attacks (TIA)/amaurosis fugax or death. Secondary outcome measures were nerve injury, bleeding complications, length of stay in hospital, stroke, restenosis (ICA patency), and all-cause death during long-term follow-up. Results: One hundred ninety-four CEA and 115 CAS procedures were performed for symptomatic and/or asymptomatic carotid artery stenosis. There is no significant differences 30-day mortality and neurologic morbidity between CAS (13%) and CEA procedures (7.7%). Length of stay in hospital were significantly longer in CEA group (p=0.001). In the post-procedural follow up, only in symptomatic patients, restenosis rate was higher in the CEA group (p=.045). The other endpoints did not differ significantly. Conclusions: Endovascular stent treatment of carotid artery atherosclerotic disease is an alternative for vascular surgery, especially for patients that are high risk for standard CEA. The increasing experience, development of cerebral protection systems and new treatment protocols increases CAS feasibility

    Mechanisms of amyloid-β34 generation indicate a pivotal role for BACE1 in amyloid homeostasis

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    The beta‑site amyloid precursor protein (APP) cleaving enzyme (BACE1) was discovered due to its “amyloidogenic” activity which contributes to the production of amyloid-beta (Aβ) peptides. However, BACE1 also possesses an “amyloidolytic” activity, whereby it degrades longer Aβ peptides into a non‑toxic Aβ34 intermediate. Here, we examine conditions that shift the equilibrium between BACE1 amyloidogenic and amyloidolytic activities by altering BACE1/APP ratios. In Alzheimer disease brain tissue, we found an association between elevated levels of BACE1 and Aβ34. In mice, the deletion of one BACE1 gene copy reduced BACE1 amyloidolytic activity by ~ 50%. In cells, a stepwise increase of BACE1 but not APP expression promoted amyloidolytic cleavage resulting in dose-dependently increased Aβ34 levels. At the cellular level, a mislocalization of surplus BACE1 caused a reduction in Aβ34 levels. To align the role of γ-secretase in this pathway, we silenced Presenilin (PS) expression and identified PS2-γ-secretase as the main γ-secretase that generates Aβ40 and Aβ42 peptides serving as substrates for BACE1’s amyloidolytic cleavage to generate Aβ34

    Mechanisms of amyloid-β34 generation indicate a pivotal role for BACE1 in amyloid homeostasis

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    The beta‑site amyloid precursor protein (APP) cleaving enzyme (BACE1) was discovered due to its "amyloidogenic" activity which contributes to the production of amyloid-beta (Aβ) peptides. However, BACE1 also possesses an "amyloidolytic" activity, whereby it degrades longer Aβ peptides into a non‑toxic Aβ34 intermediate. Here, we examine conditions that shift the equilibrium between BACE1 amyloidogenic and amyloidolytic activities by altering BACE1/APP ratios. In Alzheimer disease brain tissue, we found an association between elevated levels of BACE1 and Aβ34. In mice, the deletion of one BACE1 gene copy reduced BACE1 amyloidolytic activity by ~ 50%. In cells, a stepwise increase of BACE1 but not APP expression promoted amyloidolytic cleavage resulting in dose-dependently increased Aβ34 levels. At the cellular level, a mislocalization of surplus BACE1 caused a reduction in Aβ34 levels. To align the role of γ-secretase in this pathway, we silenced Presenilin (PS) expression and identified PS2-γ-secretase as the main γ-secretase that generates Aβ40 and Aβ42 peptides serving as substrates for BACE1's amyloidolytic cleavage to generate Aβ34

    Towards quantum 3d imaging devices

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    We review the advancement of the research toward the design and implementation of quantum plenoptic cameras, radically novel 3D imaging devices that exploit both momentum–position entanglement and photon–number correlations to provide the typical refocusing and ultra-fast, scanning-free, 3D imaging capability of plenoptic devices, along with dramatically enhanced performances, unattainable in standard plenoptic cameras: diffraction-limited resolution, large depth of focus, and ultra-low noise. To further increase the volumetric resolution beyond the Rayleigh diffraction limit, and achieve the quantum limit, we are also developing dedicated protocols based on quantum Fisher information. However, for the quantum advantages of the proposed devices to be effective and appealing to end-users, two main challenges need to be tackled. First, due to the large number of frames required for correlation measurements to provide an acceptable signal-to-noise ratio, quantum plenoptic imaging (QPI) would require, if implemented with commercially available high-resolution cameras, acquisition times ranging from tens of seconds to a few minutes. Second, the elaboration of this large amount of data, in order to retrieve 3D images or refocusing 2D images, requires high-performance and time-consuming computation. To address these challenges, we are developing high-resolution single-photon avalanche photodiode (SPAD) arrays and high-performance low-level programming of ultra-fast electronics, combined with compressive sensing and quantum tomography algorithms, with the aim to reduce both the acquisition and the elaboration time by two orders of magnitude. Routes toward exploitation of the QPI devices will also be discussed

    Factors affecting the outcome of surgically treated non-iatrogenic traumatic cervical esophageal perforation: 28 years experience at a single center

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    <p>Abstract</p> <p>Background</p> <p>We reviewed our experience with non-iatrogenic traumatic cervical esophageal perforations, paying particular attention to factors affecting the outcome of such cases.</p> <p>Methods</p> <p>In total, 30 patients treated surgically between 1980 and 2008 for non-iatrogenic traumatic cervical esophageal perforation in our clinic were reviewed.</p> <p>Results</p> <p>There were 25 male and 5 female patients with a median age of 27.5 years. The type of injury was external trauma in 21 (70%) patients and endoluminal injury in the remaining 9 (30%) patients. The mechanism of injury was gunshot in 16 patients, stabbing in 4, falling in 1 (extraluminal injury), and foreign body in 9 (endoluminal injuries). The overall mortality rate was 16.6% (5/30). The mortality rate for extraluminal injuries was 19%, and for endoluminal injuries was 11.1%. Mortality in patients treated within 24 h of sustaining injury was substantially less than in those for whom diagnosis and treatment were delayed (12.5 and 21.4%, respectively). The mortality rate was 33.3% (3/9) for patients with tracheal injuries and 9.5% (2/21) for those without tracheal injuries.</p> <p>Conclusions</p> <p>A treatment delay greater than 24 h, the presence of tracheal injury, or extraluminal perforation significantly affected the outcome of surgically treated non iatrogenic traumatic cervical esophageal perforation.</p
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