Development of a magnetic immunosorbent for on-chip preconcentration of amyloid β isoforms: Representatives of Alzheimer's disease biomarkers     

Svobodova Z  Reza Mohamadi M  Jankovicova B  Esselmann H  Verpillot R  Otto M  Taverna M  Wiltfang J  Viovy JL  Bilkova Z 《Biomicrofluidics》2012,6(2):24126-2412612

Determination of amyloid β (Aβ) isoforms and in particular the proportion of the Aβ 1-42 isoform in cerebrospinal fluid (CSF) of patients suspected of Alzheimer's disease might help in early diagnosis and treatment of that illness. Due to the low concentration of Aβ peptides in biological fluids, a preconcentration step prior to the detection step is often necessary. This study utilized on-chip immunoprecipitation, known as micro-immunoprecipitation (μIP). The technique uses an immunosorbent (IS) consisting of magnetic beads coated with specific anti-Aβ antibodies organized into an affinity microcolumn by a magnetic field. Our goal was to thoroughly describe the critical steps in developing the IS, such as selecting the proper beads and anti-Aβ antibodies, as well as optimizing the immobilization technique and μIP protocol. The latter includes selecting optimal elution conditions. Furthermore, we demonstrate the efficiency of anti-Aβ IS for μIP and specific capture of 5 Aβ peptides under optimized conditions using various subsequent analytical methods, including matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS), capillary electrophoresis, microchip electrophoresis, and immunoblotting. Synthetic Aβ peptides samples prepared in buffer and spiked in human CSF were analyzed. Finally, on-chip immunoprecipitation of Aβ peptides in human CSF sample was performed.  相似文献   

A self-tuning hybrid active noise control system     

Laleh Mokhtarpour  Hamid Hassanpour 《Journal of The Franklin Institute》2012,349(5):1904-1914

Active Noise Control (ANC) systems are increasingly used to reduce environmental noises. A hybrid ANC system is a combination of feedforward and feedback structures in which the anti-noise signal is generated using both structures. Employing the advantages of feedforward and feedback structures enables a hybrid structure to have a high performance in controlling unwanted noise. The step size of filters used in ANC systems plays an essential role in its performance. Any variation from the appropriate value leads to divergence or inefficiency of the noise controller system. These parameters are often set experimentally, which is a time-consuming task. In addition, there is no guarantee that the system can adapt itself to situational changes. The objective of this paper is to propose a new self-tuning hybrid ANC method. Using this technique, the system continuously estimates the parameters during its operation. Results of computer simulations demonstrate the robustness of the proposed method.  相似文献   

Complementary realities: Public domain Internet measurements in the development of Canada’s universal access policies     

Reza Rajabiun 《The Information Society》2019,35(2):81-94

Abstract

As access to the Internet has become increasingly essential for social and economic participation, public domain Internet measurements have become indispensable for users to validate quality of service their network operator delivers and for policymakers to identify and address gaps in broadband infrastructure. This article evaluates public domain Internet performance measurements available for assessing the state of connectivity and developing universal access service quality standards in Canada. The analysis suggests that different approaches to Internet measurement represent complementary windows into a complex and fast evolving reality of broadband connectivity. Despite their potential shortcomings, large-scale crowdsourced open data network testing platforms have a central role to play in enabling broadband infrastructure policy coordination across different levels of government, empowerment of consumers, and achievement of universal service objectives for quality of service users experience when accessing the open Internet.  相似文献   

The effects of maturation on jumping ability and sprint adaptations to plyometric training in youth soccer players     

Abbas Asadi  Rodrigo Ramirez-Campillo  Hamid Arazi 《Journal of sports sciences》2018,36(21):2405-2411

The aim of this study was to investigate the effects of maturation on power and sprint performance adaptations following 6 weeks of plyometric training in youth soccer players during pre-season. Sixty male soccer players were categorized into 3 maturity groups (Pre, Mid and Post peak height velocity [PHV]) and then randomly assigned to plyometric group and control group. Vertical jump, standing long jump, and 20-m sprint (with and without ball) tests were collected before- and after-intervention. After the intervention, the Pre, Mid and Post-PHV groups showed significant (P ≤ 0.05) and small to moderate effect size (ES) improvement in vertical jump (ES = 0.48; 0.57; 0.73), peak power output (E = 0.60; 0.64; 0.76), standing long jump (ES = 0.62; 0.65; 0.7), 20-m sprint (ES = ?0.58; ?0.66), and 20-m sprint with ball (ES = ?0.44; ?0.8; ?0.55) performances. The Post-PHV soccer players indicated greater gains than Pre-PHV in vertical jump and sprint performance after training (P ≤ 0.05). Short-term plyometric training had positive effects on sprinting and jumping-power which are important determinants of match-winning actions in soccer. These results indicate that a sixty foot contact, twice per week program, seems effective in improving power and sprint performance in youth soccer players.  相似文献   

Output feedback stabilization of switching discrete-time linear systems with parameter uncertainties     

Hamza Bibi  Fazia Bedouhene  Ali Zemouche  Hamid Reza Karimi  Houria Kheloufi 《Journal of The Franklin Institute》2017,354(14):5895-5918

This paper deals with observer-based control design for a class of switched discrete-time linear systems with parameter uncertainties. The main contribution of the paper is to propose a convenient way based on Finsler’s lemma to enhance the synthesis conditions, expressed in terms of Linear Matrix Inequalities (LMIs). Indeed, this judicious use of Finsler’s lemma provides additional decision variables, which render the LMIs less conservative and more general than all those existing in the literature for the same class of systems. Two numerical examples followed by a Monte Carlo evaluation are proposed to show the superiority of the proposed design technique.  相似文献   

Cytochrome P450 Genes (CYP2E1 and CYP1A1) Variants and Susceptibility to Chronic Hepatitis B Virus Infection     

Sadegh Fattahi  Mohammad Karimi Alivije  Farhang Babamahmoodi  Masomeh Bayani  Mahmoud Sadeghi Haddad Zavareh  Mohsen Asouri  Maryam Lotfi  Galia Amirbozorgi  Haleh Akhavan-Niaki 《Indian journal of clinical biochemistry : IJCB》2018,33(4):467-472

Hepatitis B virus (HBV) infection is a worldwide health concern which is associated with significant morbidity and mortality. Both viral and host factors have a significant effect on infection, replication and pathogenesis of HBV. The aim of this study was to investigate the effect of CYP2E1 and CYP1A1 genetic variants on susceptibility to HBV. 143 individuals including 54 chronic HBV patients and 89 healthy controls were enrolled in the genotyping procedure. rs2031920 and rs3813867 at CYP2E1 as well as rs4646421 and rs2198843 at CYP1A1 loci were studied in all subjects using PCR–RFLP (restriction fragment length polymorphism) analysis. Both variants at CYP2E1 locus were monomorphic in all studied subjects. Genotype frequency of rs4646421 was significantly different between chronic HBV patients and healthy blood donors (P = 0.04, OR 4.31; 95% CI 1.04–17.7). Furthermore, individuals carrying at least one C allele (CC or CT genotypes) for rs4646421 seemed to have a decrease risk of hepatitis in comparison with TT genotype (P = 0.039). Our results showed a relationship between rs4646421 TT genotype (rare genotype) and the risk for developing chronic HBV infection (four times higher). Further studies are needed to examine the role of CYP1A1 polymorphism in susceptibility to chronic HBV infection.  相似文献   

Mutations in HNF1A Gene are not a Common Cause of Familial Young-Onset Diabetes in Iran     

Meysam Moghbeli  Bahram Naghibzadeh  Martha Ghahraman  Sedigheh Fatemi  Morteza Taghavi  Rahim Vakili  Mohammad Reza Abbaszadegan 《Indian journal of clinical biochemistry : IJCB》2018,33(1):91-95

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Ameliorative Effects of <Emphasis Type="Italic">Allium sativum</Emphasis> Extract on iNOS Gene Expression and NO Production in Liver of Streptozotocin + Nicotinamide-Induced Diabetic Rats     

Nasrin Ziamajidi  Hamid Behrouj  Roghayeh Abbasalipourkabir  Fatemeh Lotfi 《Indian journal of clinical biochemistry : IJCB》2018,33(2):147-153

Diabetes mellitus (DM) is one of the most prevalent diseases in the world, which is strongly associated with liver dysfunction. Hyperglycemia, through an oxidative stress pathway, damages various tissues. Herbal medicine is a good candidate to ameliorate hyperglycemia and oxidative stress. In this study, the effects of aqueous Allium sativum (garlic) extract (AGE) on gene expression of inducible nitric oxide synthases (iNOS) and production of nitric oxide (NO) were evaluated in the liver tissue of diabetic rats. Four groups of rats contained normal control rats, garlic control rats (AGE), Streptozotocin (STZ) + nicotinamide-induced diabetic rats (DM), and diabetic rats treated with garlic (DM + AGE). Glucose levels and liver enzymes activities were determined by colorimetric assay in the serum. Gene expression of iNOS by real-time PCR, NO levels by Griess method, oxidative stress parameters by spectrophotometric method and histopathological examination by hematoxylin and eosin staining method were evaluated in the liver tissues. Glucose levels, activities of liver enzymes, oxidative stress markers, iNOS gene expression, and NO production increased significantly in diabetic rats in comparison with control rats, whereas after oral administration of garlic, these parameters decreased significantly, close to the normal levels. Hence, the beneficial effects of garlic on the liver injury of diabetes could be included in the hypoglycaemic and antioxidant properties of garlic via a decrease in gene expression of iNOS and subsequent NO production.  相似文献   

On the tips of their tongues: authors and their views on scholarly publishing     

David Nicholas  Hamid R. Jamali  Ian Rowlands 《Learned Publishing》2006,19(3):193-203

The paper presents the results of an international questionnaire survey of the attitudes of senior authors towards scholarly publishing. It was commissioned by the Publishers Association (PA) and the International Association of Scientific, Technical and Medical Publishers (STM). A total of 5,513 authors participated. The questionnaire included 22 closed questions and one open‐ended question that 1,943 authors used to freely express their views. Using QSR N6 textual analysis software, their comments were processed and themes extracted. The main concerns of the authors were the peer‐review process, faster publishing, better access to journals, journal prices, and issues related to electronic publishing.  相似文献   

Overdamped and Underdamped Linear Dynamical Systems     

F.M. Reza 《Journal of The Franklin Institute》1982,313(5):287-298

Conditions are given for underdamped or overdamped linear dynamical systems in terms of loop matrix parameters, (√(C)R√(C)g,g)² ? 4(√(C)L√(C)g,g) for all [boxV]g[boxV] = 1, g ∈ H. These criteria are looked upon as natural generalizations of the elementary one-loop RLC series scalar criteria (R/2L)² ? 1/LC, when written in the more suggestive form: (√(C)R√(C))² ? 4√(C)L√(C). A simplified test for determining dynamical systems with all complex natural modes or all real modes are presented with additional comments.  相似文献