Synthesis of polyhedral oligomeric silsesquioxane nano‐crosslinked poly(ethylene glycol)‐based hybrid hydrogels for drug delivery and antibacterial activity

The synthesis is reported of novel hybrid hydrogels based on ethylenediaminetetraacetic acid dianhydride and poly(ethylene glycol) (PEG) with octa‐aminopropyl polyhedral oligomeric silsesquioxane hydrochloride salt (OA‐POSS) as a nano‐crosslinker under solvent‐free conditions. The molecular weight of PEG was varied between 600 and 1000 Da. The synthesized hydrogels were characterized using various techniques. Further, the swelling behavior and antibacterial activity of the hydrogels and release kinetics of metronidazole (MTZ) as a model drug from them were evaluated. Experimental results demonstrate that hydrogels with tunable properties can be synthesized by varying the PEG molecular weight and type of crosslinker (hybrid or organic). Among the synthesized hybrid hydrogels, that crosslinked by OA‐POSS with long PEG chains (1000 Da) showed the highest swelling degree (2000%), drug encapsulation efficiency (88%) and extent of MTZ release (96%). © 2018 Society of Chemical Industry     

A NLP framework based on meaningful latent-topic detection and sentiment analysis via fuzzy lattice reasoning on youtube comments

Multimedia Tools and Applications - Social media platforms such as Twitter, Facebook, and YouTube have unique architecture, norms, and culture. These platforms are valuable sources of...     

High prevalence of bihemispheric structural and functional defects in Sturge-Weber syndrome

Abnormal cerebral venous drainage is associated with hypoxia and glucose deprivation, which can account for progressive neurologic deterioration in Sturge-Weber syndrome. Although developmental delay is common in Sturge-Weber syndrome, bihemispheric calcification is uncommon. Computed tomography (CT) and magnetic resonance imaging (MRI) were used to study the neuroanatomy, while single photon emission computed tomography (SPECT) was used concurrently to evaluate perfusion and glucose metabolism using 99mTc hexamethylpropyleneamine oxime (HMPAO) and [18F] fluorodeoxyglucose (FDG), respectively. Ten patients (10 to 22 years of age) with previously diagnosed Sturge-Weber syndrome, port-wine nevi, and clinical evidence of seizures or stroke-like episodes were studied. Five children with onset of seizures in the first year of life had overall clinical severity comparable to that of children with later-onset seizures. Calcification was present in both hemispheres in one patient; six additional patients had other radiologic evidence of bihemispheric disease; SPECT studies detected bihemispheric disease in four cases. Our study is the first to concurrently evaluate structure, perfusion, and glucose metabolism in Sturge-Weber syndrome and to show a mismatch between functional and structural brain imaging in both cerebral hemispheres. Widespread abnormalities of cerebral perfusion and glucose metabolism might explain the high prevalence of developmental delay associated with Sturge-Weber syndrome. Longitudinal studies are needed to define better the natural history of neurologic deterioration and radiologic progression that relates to central nervous system circulatory dysfunction in Sturge-Weber syndrome.     

Experimental investigation on the adsorption/desorption processes using solid desiccant in an inclined-fluidized bed

This paper presents an experimental investigation on the adsorption and desorption operations in an inclined-fluidized bed using silica gel as the working desiccant. The experimental system involves a circular glass tube containing the particles of silica gel, which is tested at an inclination angle of 45°. The moisture capacity of the bed is measured using a gravimetric technique. Process air at nearly constant ambient parameters (humidity and temperature) and different values of flow rate are used during adsorption. Moisture concentration in the bed is analyzed through visual observation of the color of silica gel particles. Experimental measurements indicate that the regeneration and adsorption rates are highly dependent on the air stream velocity. A satisfactory regeneration rate is confirmed at regeneration temperature as low as 90 °C when inclined-fluidized bed is applied. The transient-state moisture transfer rates during adsorption and desorption are presented. Finally, observation of the movement and color of the particles in the bed show regular circulation and homogenous distribution of moisture concentration.     

Effect of time on the stress–strain behaviour of a single rock joint

The time-dependent behaviour of discontinuities is important in many geotechnical applications. To investigate the stress–strain behaviour of jointed specimens tested at various rates of strain and at constant deformation in various stress conditions, three cases were examined: (a) increasing compressive load at different constant strain rates, (b) increasing compressive load at changing strain rates, (c) stress variations with a constant amount of displacement along the complete stress–strain curves for 5 min (stress relaxation). Triaxial tests were carried out on samples of the Penrith and Stainton Sandstones using a 5 MN servo-controlled stiff testing machine and confining pressures in the range of 0–30 MPa. Both intact and jointed specimens with saw cut and split joints were tested. The joints were produced with orientations of 30, 45 and 60° to the direction of the principal stress. Three different strain rates were applied.      

Synthesis of acyclo C-nucleosides of phenanthro[9,10-e][1,2, 4]triazino[3,4-c]-[1,2,4]triazoles, and their precursors

Reaction of 3-hydrazinophenanthro [9, 10-e] [1, 2, 4] triazine (1) with aliphatic and aromatic aldehydes as well as monosaccharides gave the corresponding hydrazones 2a-g. The D-glucose analogue exists in the cyclic pyranosyl structure 5. Acetylation and partial acetylation of the sugar hydrazones were carried out. Cyclization of a number of hydrazones including the partially acetylated sugar hydrazones by thionyl chloride gave regioselectively the respective angular isomer 1-substituted phenanthro [9, 10-e] [1, 2, 4] triazino [3, 4- and not the linear isomer. The cyclization of 1 with acetic acid, however, gave regioselectively the linear isomer 19. The structural assignments were based on a model study whereby the angular 16a was found to be different from the linear isomer 19a obtained by the condensation of 4, 5-diamino-3-methyl-1, 2, 4-triazole with 9, 10-phenanthraquinone. Periodate oxidation of 2d gave 20 whose reaction with 1 gave 21.     

Synergistic effects of ACE inhibition and Ang II antagonism on blood pressure, cardiac weight, and renin in spontaneously hypertensive rats

BACKGROUND: Blockade of type 1 angiotensin (Ang) II receptors combined with ACE inhibition may amplify the efficacy of the renin-angiotensin system blockade because ACE inhibitors do not completely and permanently suppress Ang II production. METHODS AND RESULTS: Enalapril or losartan (1, 3, 10, and 30 mg/kg) or their combination was administered for 2 to 4 weeks to spontaneously hypertensive rats. The combination of low doses of each agent induced greater reductions in blood pressure (BP) and left ventricular weight/body weight (LVW/ BW) ratio than monotherapy with the same or higher doses. When approximately equipotent regimens of enalapril, losartan, and their combination, as judged by BP fall, were compared, there were similar increases in plasma and renal renin and in plasma Ang-(1-7) and Ang I and similar reductions in plasma angiotensinogen. Enalapril alone reduced plasma Ang II levels, and losartan alone increased Ang II levels. The combination of enalapril with losartan prevented or reduced the increase in Ang II levels observed with losartan alone. CONCLUSIONS: These findings show that the synergistic interaction between the effects of low doses of enalapril and losartan on BP and LVW/BW ratio is due to more effective inhibition of the renin-angiotensin system by their combination than by either agent alone. When both drugs are given together, the ACE inhibitor-induced fall in plasma Ang II results in modulation of the Ang II antagonist-induced reactive rise in Ang II, thereby lowering the plasma Ang II concentration, which competes with the antagonist for the Ang II receptors.     

The hemoregulatory peptide N-acetyl-ser-asp-lys-pro impairs angiotensin I-induced contractions in rat aorta

Two recent findings are summarized here that bear on the organization of memory and brain systems. First, the capacity for simple recognition of familiarity (a form of declarative memory) depends on the hippocampal region in both humans and nonhuman primates. Second, probabilistic classification learning (a form of nondeclarative memory akin to habit learning) depends on the caudate nucleus and putamen. These findings are related to the classification of long-term memory and current understanding of the participating brain systems.     

Classic Kaposi's sarcoma in Jews living in Israel, 1961-1989: a population-based incidence study

BACKGROUND: The incidence of classic Kaposi's sarcoma (CKS) has been reported to be high in Jewish populations, mostly born in Eastern Europe. OBJECTIVE: To describe the incidence on CKS in Israeli Jews and to determine differences in incidence according to their geography origin. DESIGN: We analysed data on 1098 incident CKS cases with known country of origin occurring between 1961 and 1989 in the Jewish Israeli population. Reporting systems were the Israel Cancer Registry, the medical documentation of all-Kaposi's sarcoma cases and the registry of HIV-seropositive patients. Patients who were seropositive for HIV were excluded from the study population. Population figures for groups of migrants and natives were derived from census surveys (1961, 1972, 1983) and inter-census estimates based on the population registry. RESULTS: The overall age-standardized rate of CKS was 16.9 per million in men and 6.3 per million in women. The ratio between genders remained stable during the study period. In both genders, there was a steep increase in CKS incidence between the late 1960s (age-standardized rates per million: 8.0 in men and 2.2 in women) and the early 1970s (17.9 in men and 6.7 in women). No further increase was present after 1971. Overall, immigrants experienced a relative risk (RR) of 1.17 [95% confidence interval (CI) 0.90-1.521 compared with Jews born in Israel. Immigrants from Morocco, Algeria and Tunisia had the highest incidence (RR 2.01; 95% CI 1.52-2.65) compared with Jews born in Israel, followed by those born in Iraq (RR 1.74; CI 95% 1.27-2.37). The lowest incidence was experienced by immigrants from Iran (RR 0.37; CI 95% 0.18-0.77) and from Central European countries (RR 0.45; CI 95% 0.30-0.66). Immigrants from other countries in Asia, Africa, the Americas and Europe had similar rates as Jews born in Israel. CONCLUSIONS: Israeli Jews present one of the highest incidences of CKS reported from developed countries. The incidence varies according to geographical origin. Countries surrounding the Mediterranean sea represent the area of highest CKS incidence.     

Vibration suppression in ultrasonic machining described by non-linear differential equations

Vibrations are usually undesired phenomena as they may cause damage or destruction of the system. However, sometimes they are desirable, as in ultrasonic machining (USM). In such case, the problem is a complicated one, as it is required to reduce the vibration of the machine head and have reasonable amplitude for the tool. In the present work, the coupling of two non-linear oscillators of the tool holder and tool representing ultrasonic cutting process is investigated. This leads to a two-degree-of-freedom system subjected to multi-external excitation force. The aim of this work is to control the tool holder behavior at simultaneous primary and internal resonance condition and have high amplitude for the tool. Multiple scale perturbation method is applied to obtain a solution up to the second order approximations. Other different resonance cases are reported and studied numerically. The stability of the system is investigated applying both phase-plane and frequency response techniques. The effects of the different parameters of the tool on the system behavior are studied numerically. Comparison with the available published work is reported. This paper was recommended for publication in revised form by Associate Editor Eung-Soo Shin M. M. Kamel received his B.S. degree in Mathematics from Ain Shams University, EGYPT, in 1979. He then received his M.S.c degrees from Ain Shams University, in 1986 and Ph.D. degrees from Menofia University, in 1994. Dr. M. M. Kamel is currently an Associate Professor of Mathematics at the Department of Engineering Mathematics, Faculty of Electronic Engineering Menofia University, Egypt. Dr. M. M. Kamel research interests include Differential equations, Numerical Analysis, and Vibration control. W. A. A. El-Ganini received her B.S. degree in Mathematics from Ain Shams University, EGYPT, in 1980. She then received her M.S.c and Ph.D. degrees from Suez Canal University, in 1984 and 1989, respectively. Dr. W. A. A. El-Ganini is currently an Assistant Professor of Mathematics at the Department of Engineering Mathematics, Faculty of Electronic Engineering Menofia University, Egypt. Dr. W. A. A. El-Ganaini research interests include Differential equations, Numerical Analysis, and Vibration control. Y. S. Hamed received his B.S. degree in Mathematics from Menofia University, EGYPT, in 1998. He then received his M.S.c and Ph.D. degrees from Menofia University, in 2005 and 2009, respectively. Dr. Y. S. Hamed is currently an Assistant Professor of Pure Mathematics at the Department of Engineering Mathematics, Faculty of Electronic Engineering Menofia University, Egypt. Dr. Y. S. Hamed research interests include Differential equations, Numerical Analysis, and Vibration control.