451 research outputs found
Review of bio-particle manipulation using dielectrophoresis
During the last decade, large and costly instruments are being replaced by system based on microfluidic devices. Microfluidic devices hold the promise of combining a small analytical laboratory onto a chip-sized substrate to identify, immobilize, separate, and purify cells, bio-molecules, toxins, and other chemical and biological materials. Compared to conventional instruments, microfluidic devices would perform these tasks faster with higher sensitivity and efficiency, and greater affordability. Dielectrophoresis is one of the enabling technologies for these devices. It exploits the differences in particle dielectric properties to allow manipulation and characterization of particles suspended in a fluidic medium. Particles can be trapped or moved between regions of high or low electric fields due to the polarization effects in non-uniform electric fields. By varying the applied electric field frequency, the magnitude and direction of the dielectrophoretic force on the particle can be controlled. Dielectrophoresis has been successfully demonstrated in the separation, transportation, trapping, and sorting of various biological particles.Singapore-MIT Alliance (SMA
HUBUNGAN MASA KERJA DI LUAR RUANGAN DAN PENGGUNAAN APD DENGAN KEJADIAN KATARAK PASIEN POLI MATA RSUD S. K. LERIK KUPANG
Katarak berada di posisi kedua penyebab gangguan penglihatan terbanyak di seluruh dunia (33%) setelah gangguan refraksi dan di urutan pertama penyebab kebutaan terbanyak di dunia (51%).Radiasi UV dan stres oksidatif dianggap sebagai faktor penting dalam patogenesis katarak. Orang yang bekerja lebih banyak di luar gedung berisiko mengalami katarak, terlebih bagi mereka yang tidak menggunakan alat pelindung diri (APD) untuk mata. Tujuan penelitian ini untuk mengetahui hubungan masa kerja di luar ruangan dan penggunaan APD dengan kejadian katarak pasien Poli Mata RSUD S. K. Lerik Kupang 2018-2019. Metode penelitian ini adalah analitik observasional dengan desain kasus kontrol. Populasi dalam penelitian ini adalah semua pasienpolimata RSUD S. K. LerikKupang. Sampel dalam penelitian berjumlah 60 responden dengan teknik sampel yang digunakan adalah purposive sampling. Pengumpulan data dilakukan dengan kuesioner. Data dianalisis dengan rumus uji koefisien kontingensi c. Hasil analsisi menunjukkan tidak derdapat hubungan yang bermakna antara masa kerja di luar ruangan dengan kejadian katarak,p value = 0,640 (p > 0,05) dengan OR=1,556, dan tidak derdapat hubungan yang bermakna antara penggunaan APD dengan kejadian katarak,p value = 0,129 dan OR=0,289 (<1). Kesimpulan dari penelitian ini tidak terdapat hubungan yang bermakna antara masa kerja di luar ruangan dan penggunaan APD dengan terjadinya katarak di Poli Mata RSUD. S. K. Lerik Kupan
CF_2XCF_2X and CF_2XCF_2• Radicals (X = Cl, Br, I): Ab Initio and DFT Studies and Comparison with Experiments
1,2-dihalotetrafluoroethanes (CF_2XCF_2X, X = I, Br and Cl) and halotetrafluoroethyl radicals (CF_2XCF_2•, X = I, Br, and Cl) have been studied by ab initio molecular-orbital techniques using restricted Hartree−Fock and Density functional theory (DFT-B3PW91). For the optimized HF geometries, we carried out local MP2 calculations to account for electron correlation effects. Each CF_2XCF_2X molecule and CF_2XCF_2• radical has two conformational minima (anti and gauche) and two rotational transition structures in the rotational energy surface along the C−C bond. The rotational barriers of the radicals are smaller than those of the parent molecules due to the absence of the nonbonded interaction between two halogen atoms. In contrast, the conformational energy difference between two stable rotamers (anti and gauche) of each radical is larger than that in the corresponding parent molecules. This stabilizing effect on the anti conformers of the radicals is rationalized in terms of hyperconjugation between the radical center and the σ^*(C−X) molecular orbital. The dissociation energies for breaking the first and second C−X bonds of CF_2XCF_2X were also calculated and compared with available experimental data. The CF_2XCF_2• radicals show dramatically different behavior compared with haloethyl radicals (CH_2XCH_2•). The CF_2XCF_2• radical has two minima and two saddle points, whereas CH_2XCH_2• radical has only one minimum and one saddle point in the rotational energy surface. In addition, the bridged structures are not stable for CF_2XCF_2• radicals in contrast with CH_2XCH_2• radicals. The origin of these differences is attributed to differences in the environment of the radical center. The calculated structures of the CF_2ICF_2• radical were used in interpreting a recent experimental observation (Cao et al. Proc. Natl. Acad. Sci. 1999, 96, 338) and are compared with quantitative results from a new experiment (Ihee et al. Science 2001, 291, 458) using the ultrafast electron diffraction technique
CF_2XCF_2X and CF_2XCF_2• Radicals (X = Cl, Br, I): Ab Initio and DFT Studies and Comparison with Experiments
1,2-dihalotetrafluoroethanes (CF_2XCF_2X, X = I, Br and Cl) and halotetrafluoroethyl radicals (CF_2XCF_2•, X = I, Br, and Cl) have been studied by ab initio molecular-orbital techniques using restricted Hartree−Fock and Density functional theory (DFT-B3PW91). For the optimized HF geometries, we carried out local MP2 calculations to account for electron correlation effects. Each CF_2XCF_2X molecule and CF_2XCF_2• radical has two conformational minima (anti and gauche) and two rotational transition structures in the rotational energy surface along the C−C bond. The rotational barriers of the radicals are smaller than those of the parent molecules due to the absence of the nonbonded interaction between two halogen atoms. In contrast, the conformational energy difference between two stable rotamers (anti and gauche) of each radical is larger than that in the corresponding parent molecules. This stabilizing effect on the anti conformers of the radicals is rationalized in terms of hyperconjugation between the radical center and the σ^*(C−X) molecular orbital. The dissociation energies for breaking the first and second C−X bonds of CF_2XCF_2X were also calculated and compared with available experimental data. The CF_2XCF_2• radicals show dramatically different behavior compared with haloethyl radicals (CH_2XCH_2•). The CF_2XCF_2• radical has two minima and two saddle points, whereas CH_2XCH_2• radical has only one minimum and one saddle point in the rotational energy surface. In addition, the bridged structures are not stable for CF_2XCF_2• radicals in contrast with CH_2XCH_2• radicals. The origin of these differences is attributed to differences in the environment of the radical center. The calculated structures of the CF_2ICF_2• radical were used in interpreting a recent experimental observation (Cao et al. Proc. Natl. Acad. Sci. 1999, 96, 338) and are compared with quantitative results from a new experiment (Ihee et al. Science 2001, 291, 458) using the ultrafast electron diffraction technique
healthcareCOVID: a national cross-sectional observational study identifying risk factors for developing suspected or confirmed COVID-19 in UK healthcare workers.
To establish the prevalence, risk factors and implications of suspected or confirmed coronavirus disease 2019 (COVID-19) infection among healthcare workers in the United Kingdom (UK). Cross-sectional observational study. UK-based primary and secondary care. Healthcare workers aged ≥18 years working between 1 February and 25 May 2020. A composite endpoint of laboratory-confirmed diagnosis of SARS-CoV-2, or self-isolation or hospitalisation due to suspected or confirmed COVID-19. Of 6,152 eligible responses, the composite endpoint was present in 1,806 (29.4%) healthcare workers, of whom 49 (0.8%) were hospitalised, 459 (7.5%) tested positive for SARS-CoV-2, and 1,776 (28.9%) reported self-isolation. Overall, between 11,870 and 21,158 days of self-isolation were required by the cohort, equalling approximately 71 to 127 working days lost per 1,000 working days. The strongest risk factor associated with the presence of the primary composite endpoint was increasing frequency of contact with suspected or confirmed COVID-19 cases without adequate personal protective equipment (PPE): 'Never' (reference), 'Rarely' (adjusted odds ratio 1.06, (95% confidence interval: [0.87-1.29])), 'Sometimes' (1.7 [1.37-2.10]), 'Often' (1.84 [1.28-2.63]), 'Always' (2.93, [1.75-5.06]). Additionally, several comorbidities (cancer, respiratory disease, and obesity); working in a 'doctors' role; using public transportation for work; regular contact with suspected or confirmed COVID-19 patients; and lack of PPE were also associated with the presence of the primary endpoint. A total of 1,382 (22.5%) healthcare workers reported lacking access to PPE items while having clinical contact with suspected or confirmed COVID-19 cases. Suspected or confirmed COVID-19 was more common in healthcare workers than in the general population and is associated with significant workforce implications. Risk factors included inadequate PPE, which was reported by nearly a quarter of healthcare workers. Governments and policymakers must ensure adequate PPE is available as well as developing strategies to mitigate risk for high-risk healthcare workers during future COVID-19 waves. [Abstract copyright: © 2021 Kua et al.
Dataset on gene expression in the elderly after Mindfulness Awareness Practice or Health Education Program
It has been reported that relaxation techniques can improve physical health and cognitive function. A number of studies involving different types of relaxation practices showed changes in expression of genes. We investigated the gene expression pattern of a cohort of elderly subjects of Asian descent after weekly (for the first three months) and monthly (for the subsequent six months) intervention. Sixty consenting elderly subjects (aged 60–90 years) with mild cognitive impairment were assigned to either the Mindfulness Awareness Practice (MAP) or Health Education Program (HEP) group in a randomized controlled trial to assess the effectiveness of the programs in preventing further cognitive decline and evaluate the influence on neurological, cellular and biochemical factors. Blood samples were collected before the start of intervention and after nine months for gene expression profiling using Affymetrix Human Genome U133 Plus 2.0 arrays. The dataset is publicly available for further analyses
Inflammatory complications of CGRP monoclonal antibodies: a case series
BACKGROUND:
Calcitonin gene-related peptide (CGRP) is expressed throughout the body and is a known mediator of migraine, exerting this biological effect through activation of trigeminovascular, meningeal and associated neuronal pathways located in close proximity to the central nervous system. Monoclonal antibodies (mAb) targeting the CGRP pathway are an effective new preventive treatment for migraine, with a generally favourable adverse event profile. Pre-clinical evidence supports an anti-inflammatory/immunoregulatory role for CGRP in other organ systems, and therefore inhibition of the normal action of this peptide may promote a pro-inflammatory response.
CASES:
We present a case series of eight patients with new or significantly worsened inflammatory pathology in close temporal association with the commencement of CGRP mAb therapy.
CONCLUSION:
This case series provides novel insights on the potential molecular mechanisms and side-effects of CGRP antagonism in migraine and supports clinical vigilance in patient care going forward
Next-to-Leading Order Constituent Quark Structure and Hadronic Structure Functions
We calculate the partonic structure of a constituent quark in the
Next-to-Leading Order framework. The structure of any hadron can be obtained
thereafter using a convolution method. Such a procedure is used to generate the
structure function of proton and pion in NLO, neglecting certain corrections to
. It is shown that while the constituent quark structure is
generated purely perturbatively and accounts for the most part of the hadronic
structure, there is a few percent contributions coming from the nonperturbative
sector in the hadronic structure. This contribution plays the key role in
explaining the SU(2) symmetry breaking of the nucleon sea and the observed
violation of Gottfried sum rule. These effects are calculated. We obtained an
Excellent agreement with the experimental data in a wide range of and for the proton structure function. We
have also calculated Pion structure and compared it with the existing data.
Again, the model calculations agree rather well with the data from experiment.Comment: 32 pages,10 figures, Accepted to publish in Phys. Rev.
Look ahead to improve QoE in DASH streaming
[EN] When a video is encoded with constant quality, the resulting bitstream will have variable bitrate due to the inherent nature of the video encoding process. This paper proposes a video Adaptive Bitrate Streaming (ABR) algorithm, called Look Ahead, which takes into account this bitrate variability in order to calculate, in real time, the appropriate quality level that minimizes the number of interruptions during the playback. The algorithm is based on the Dynamic Adaptive Streaming over HTTP (DASH) standard for on-demand video services. In fact, it has been implemented and integrated into ExoPlayer v2, the latest version of the library developed by Google to play DASH contents. The proposed algorithm is compared to the Müller and Segment Aware Rate Adaptation (SARA) algorithms as well as to the default ABR algorithm integrated into ExoPlayer. The comparison is carried out by using the most relevant parameters that affect the Quality of Experience (QoE) in video playback services, that is, number and duration of stalls, average quality of the video playback and number of representation switches. These parameters can be combined to define a QoE model. In this sense, this paper also proposes two new QoE models for the evaluation of ABR algorithms. One of them considers the bitrate of every segment of each representation, and the second is based on VMAF (Video Multimethod Assessment Fusion), a Video Quality Assessment (VQA) method developed by Netflix. The evaluations presented in the paper reflect: first, that Look Ahead outperforms the Müller, SARA and the ExoPlayer ABR algorithms in terms of number and duration of video playback stalls, with hardly decreasing the average video quality; and second, that the two QoE models proposed are more accurate than other similar models existing in the literature.This work is supported by the PAID-10-18 Program of the Universitat Politecnica de Valencia (Ayudas para contratos de acceso al sistema espanol de Ciencia, Tecnologia e Innovacion, en estructuras de investigacion de la Universitat Politecnica de Valencia) and by the Project 20180810 from the Universitat Politecnica de Valencia ("Tecnologias de distribucion y procesado de informacion multimedia y QoE").Belda Ortega, R.; De Fez Lava, I.; Arce Vila, P.; Guerri Cebollada, JC. (2020). Look ahead to improve QoE in DASH streaming. 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Published: May (2018)Yu L, Tillo T, Xiao J (2017) QoE-driven dynamic adaptive video streaming strategy with future information. IEEE Trans on Broadcast 63-3:523–534. https://doi.org/10.1109/TBC.2017.2687698Zhao S, Li Z, Medhi D, Lai P, Liu S (2017) Study of user QoE improvement for dynamic adaptive streaming over HTTP (MPEG-DASH). Proc. of the Int. Conf. On Comput., network. And Commun. (ICNC): multimed. Comput. And Commun., Santa Clara, CA, USA: 566-570. https://doi.org/10.1109/ICCNC.2017.7876191 .Zhou Y, Duan Y, Sun J, Guo Z (2014) Towards a simple and smooth rate adaption for VBR video in DASH. Proc. of the IEEE Vis. Commun. and Image Process. Conf, Valletta, pp 9–12. https://doi.org/10.1109/VCIP.2014.7051491Zhou C, Lin C-W, Guo Z (2016) mDASH: a Markov decision-based rate adaptation approach for dynamic HTTP streaming. IEEE Trans. on Multimed 18(4):738–751. https://doi.org/10.1109/TMM.2016.252265
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