Joint Spectrum Sensing and Resource Allocation for OFDM-based Transmission with a Cognitive Relay

In this paper, we investigate the joint spectrum sensing and resource allocation problem to maximize throughput capacity of an OFDM-based cognitive radio link with a cognitive relay. By applying a cognitive relay that uses decode and forward (D&F), we achieve more reliable communications, generating less interference (by needing less transmit power) and more diversity gain. In order to account for imperfections in spectrum sensing, the proposed schemes jointly modify energy detector thresholds and allocates transmit powers to all cognitive radio (CR) subcarriers, while simultaneously assigning subcarrier pairs for secondary users (SU) and the cognitive relay. This problem is cast as a constrained optimization problem with constraints on (1) interference introduced by the SU and the cognitive relay to the PUs; (2) miss-detection and false alarm probabilities and (3) subcarrier pairing for transmission on the SU transmitter and the cognitive relay and (4) minimum Quality of Service (QoS) for each CR subcarrier. We propose one optimal and two sub-optimal schemes all of which are compared to other schemes in the literature. Simulation results show that the proposed schemes achieve significantly higher throughput than other schemes in the literature for different relay situations.Comment: EAI Endorsed Transactions on Wireless Spectrum 14(1): e4 Published 13th Apr 201

SYNTHESIS, ANTICANCER EVALUATION AND MOLECULAR MODELING OF SOME SUBSTITUTED THIAZOLIDINONYL AND THIAZOLYL PYRAZOLE DERIVATIVES

Objective: The present work aimed to synthesize some new substituted thiazoles incorporated to pyrazole moiety starting from 1-(3-chlorophenyl)-3-(4-methoxyphenyl)-1H-pyrazole-4-carboxaldehyde (1) in order to evaluate their anticancer activity and GSTP1 inhibition in a trail to explore new potential GST inhibitors and prevent the resistance of cells to anticancer drugs. In addition, investigate the probability of the most promising cytotoxic compounds to inhibit GSTP1 enzyme via molecular docking study.Methods: The carboxaldehyde 1 was treated with substituted thiosemicarbazide in absolute ethanol to give the corresponding thiosemicarbazone derivatives 2a–d. Cyclization of 2a-d either by ethyl bromoacetate, phenacyl bromide or maleic acid anhydride furnished new thiazole derivatives 3, 4 and 5, respectively. These target compound 2-5 were screened for their GSTP1 inhibition and cytotoxic activity against HEPG-2 (human liver carcinoma), A549 (human lung carcinoma) and PC3 (human prostate carcinoma). Finally, molecular docking study of the most promising cytotoxic compounds against GSTP1 (PDB ID: 3GUS) is discussed.Results: Compounds 4a, 4b, and 4d were found to be highly active against HEPG-2 and PC-3 cancer cell lines with IC50 values ranging from 0.2±0.81 to 9.3±2.08 μM compared to doxorubicin with IC50= 37.8±1.50 and 41.1±2.01 μM, respectively. Screening of 4a, 4b and 4d against GSTP1 showed higher inhibition activity with IC50 ranging from 1.5±0.18 to 4.3±0.29 μM. Docking studies revealed the promising binding affinities of the latter compounds which match with the binding mode of the ligand, NBDHEX toward the active site of GSTP1.Conclusion: Compounds 4a, 4b and 4d were distinguished by the higher anticancer activity against HEPG-2, A-549 and PC-3 cell lines of tumor and the remarkable inhibitory activity against GSTP1

Plasma Adrenomedullin level in Egyptian children and Adolescents with type 1 diabetes mellitus: relationship to microvascular complications

<p>Abstract</p> <p>Background</p> <p>Adrenomedullin (AM) is known to be elevated in different clinical situations including diabetes mellitus (DM), but its potential role in the pathogenesis of vascular complications in diabetic children and adolescents is to be clarified. Hence, the study aimed at assessment of plasma adrenomedullin levels in children and adolescents with type 1 DM and correlation of these levels with metabolic control and diabetic microvascular complications (MVC).</p> <p>Methods</p> <p>The study was performed in the Diabetes Specialized Clinic, Children's Hospital of Ain Shams University in Cairo, Egypt. It included 55 diabetic children and adolescents (mean age 13.93 ± 3.15 years) who were subdivided into 40 with no MVC and 15 with MVC. Thirty healthy subjects, age-and sex- matched were included as control group (mean age 12.83 ± 2.82 years). Patients and controls were assessed for glycosylated hemoglobin (HbA1c) and plasma adrenomedullin assay using ELISA technique.</p> <p>Results</p> <p>Mean plasma AM levels were significantly increased in patients with and without MVC compared to control group, (110.6 pg/mL, 60.25 pg/mL and 39.2 pg/mL respectively) (P < 0.01) with higher levels in those with MVC (P < 0.05). Plasma AM levels were positively correlated with both duration of diabetes (ρ = 0.703, P < 0.001) and glycemic control (HbA1c) (ρ = 0.453, P < 0.001).</p> <p>Conclusion</p> <p>Higher plasma AM levels in diabetics particularly in those with MVC & its correlation with diabetes duration and metabolic control may reflect the role of AM in diabetic vasculopathy in the pediatric age group.</p

A roadmap to develop dementia research capacity and capability in Pakistan: a model for low- and middle-income countries

Objective To produce a strategic roadmap for supporting the development of dementia research in Pakistan. Background While global research strategies for dementia research already exist, none is tailored to the specific needs and challenges of low- and middle-income countries (LMIC) like Pakistan. Methods We undertook an iterative consensus process with lay and professional experts to develop a Theory of Change-based strategy for dementia research in Pakistan. This included Expert Reference Groups (ERGs), strategic planning techniques, a “research question” priority survey, and consultations with Key Opinion Leaders. Results We agreed on ten principles to guide dementia research in Pakistan, emphasizing pragmatic, resource sparing, real-world approaches to support people with dementia, both locally and internationally. Goals included capacity/capability building. Priority research topics included raising awareness and understanding of dementia, and improving quality of life. Conclusion This roadmap may be a model for other LMIC health ecosystems with emerging dementia research cultures

EGFR tyrosine kinase targeted compounds

In this study, we illustrate computer aided drug design of new benzothiazole and pyrimido[2,1-b]benzothiazole derivatives as epidermal growth factor receptor tyrosine kinase (EGFR-TK) inhibitors. Compounds 1-5 were screened at NCI, USA, for antitumor activity against non-small cell lung cancer (NCI-H522), colon cancer (HCT-116, HCT-15 and HT29) and breast cancer (MDA-MB-468 and MDA-MB-231/ATCC) cell lines in which EGFR is overexpressed in varying levels. Results indicated that these compounds are more potent antitumor agents compared to erlotinib against HT29 and MDA-MB-231/ATCC cell lines. Compound 3 showed GI50 value of 22.3 nM against NCI-H522 cell line, while erlotinib exhibited GI50 value of 1 μM against the same cell line. In addition, these compounds were studied for their EGFR tyrosine kinase inhibitory activity. Virtual screening utilizing molecular modeling and QSAR techniques enabled the understanding of the pharmacophoric requirements for antitumor activity. Docking the designed compounds into the ATP binding site of EGFR-TK domain was done to predict the analogous binding mode of these compounds to the EGFR-TK inhibitors

Use of the Dexamethasone-Corticotrophin Releasing Hormone Test to Assess Hypothalamic-Pituitary-Adrenal Axis Function in Rheumatoid Arthritis

Objectives. Hypothalamic-Pituitary-Adrenal axis function may be abnormal in rheumatoid arthritis (RA). A pilot study in 7 patients suggested impaired glucocorticoid feedback in some patients after the dexamethasone-corticotrophin releasing hormone (CRH) test. This study aimed to investigate the dexamethasone-corticotrophin releasing factor test in a larger group of patients and relate the results to characteristics of the disease. Methods. Outpatients with active RA (≥3 swollen and tender joints and C-reactive protein > 10 mg/L) took dexamethasone (1.5 mg) at 23:00 hour in the evening. Next day, baseline saliva and plasma samples were collected, CRH was infused at 11:00 hour, and 4 serial blood and saliva samples were collected. Plasma samples were stored at −80°C and a radioimmunoassay performed for saliva and plasma cortisol. Results. All 20 participants showed normal dexamethasone suppression and mounted no response to the CRH challenge. In samples with measurable cortisol, there was a strong correlation between saliva and plasma values (r = 0.876, n = 26, P < .01). Conclusion. No abnormalities were found in the Dexamethasone-CRH test in RA patients in contrast to a previous pilot study. Salivary cortisol measurement may offer an alternative noninvasive technique to plasma cortisol in RA patients in future studies

Rayleigh-Poisson Distribution: Properties and Estimation with Applications of COVID-19 Mortality Rate

In this paper, we introduce the Rayleigh-Poisson distribution, a generalization of the Rayleigh distribution with three parameters. The Rayleigh-Poisson distribution is more flexible than the Rayleigh distribution and can be used to model a wider range of lifetime data. The article derives closed-form expressions for several properties of the Rayleigh-Poisson distribution. The unknown model parameters are estimated and a simulation study is performed to study the behavior of the estimators. Three real datasets of COVID-19 are applied to demonstrate the Rayleigh-Poisson distribution superior performance compared to well-known lifetime distributions

Antimicrobial Activity of Terpenoids Extracted from Annona muricata Seeds and its Endophytic Aspergillus niger Strain SH3 Either Singly or in Combination

BACKGROUND: Annona muricata (Soursop) has an antimicrobial activity toward various pathogenic microorganisms which support its ethnomedicinal for the treatment of many infectious diseases. AIM: Aim of the present study to evaluate the relation between antimicrobial activities of terpenoids extracted from different soursop parts with the isolated endophytic fungi. METHODS: Endophytic fungal species of pulp and peel of Annona fruit along with those of seeds were isolated. Salkowski test was used for qualitative screening of terpenoids in plant and the isolated endophytic Aspergillus niger strain SH3. RESULTS: Endophytic A. niger strain SH3 and Annona seed extract showed high terpenoid content indicated by the high intensity of reddish-brown colour. GC/Mass analysis revealed six compounds of terpenoids from endophytic A. niger strain SH3 extract and four compounds from seed extract with different retention times. The antimicrobial assay was performed using A. niger strain SH3 extract and Annona seed extract singly or in combinations against S. aureus, P. aeruginosa, E. coli and C. albicans. CONCLUSION: The results revealed the significant antimicrobial activity of both extracts. However, the combined extract showed some reduction in antimicrobial activity which could be attributed to the antagonistic effect exhibited by their constituents

Localization for Random Unitary Operators

We consider unitary analogs of $1-$dimensional Anderson models on $l^2(\Z)$ defined by the product $U_\omega=D_\omega S$ where $S$ is a deterministic unitary and $D_\omega$ is a diagonal matrix of i.i.d. random phases. The operator $S$ is an absolutely continuous band matrix which depends on a parameter controlling the size of its off-diagonal elements. We prove that the spectrum of $U_\omega$ is pure point almost surely for all values of the parameter of $S$. We provide similar results for unitary operators defined on $l^2(\N)$ together with an application to orthogonal polynomials on the unit circle. We get almost sure localization for polynomials characterized by Verblunski coefficients of constant modulus and correlated random phases

Microwave-assisted synthesis and antitumor evaluation of a new series of thiazolylcoumarin derivatives

A new series of thiazolylcoumarin derivatives was synthesized. The designed strategy embraced a molecular hybridization approach which involves the combination of the thiazole and coumarin pharmacophores together. The new hybrid compounds were tested for in vitro antitumor efficacy over cervical (Hela) and kidney fibroblast (COS-7) cancer cells. Compounds 5f, 5h, 5m and 5r displayed promising efficacy toward Hela cell line. In addition, 5h and 5r were found to be the most active candidates toward COS-7 cell line. The four active analogs, 5f, 5h, 5m and 5r were screened for in vivo antitumor activity over EAC cells in mice, as well as in vitro cytotoxicity toward W138 normal cells. Results illustrated that 5r has the highest in vivo activity, and that the four analogs are less cytotoxic than 5-FU toward W138 normal cells. In this study, 3D pharmacophore analysis was performed to investigate the matching pharmacophoric features of the synthesized compounds with trichostatin A. In silico studies showed that the investigated compounds meet the optimal needs for good oral absorption with no expected toxicity hazards