Hypoglycaemia‐free artificial pancreas project

Driving blood glycaemia from hyperglycaemia to euglycaemia as fast as possible while avoiding hypoglycaemia is a major problem for decades for type‐1 diabetes and is solved in this study. A control algorithm is designed that guaranties hypoglycaemia avoidance for the first time both from the theory of positive systems point of view and from the most pragmatic clinical practice. The solution consists of a state feedback control law that computes the required hyperglycaemia correction bolus in real‐time to safely steer glycaemia to the target. A rigorous proof is given that shows that the control‐law respects the positivity of the control and of the glucose concentration error: as a result, no hypoglycaemic episode occurs. The so‐called hypo‐free strategy control is tested with all the UVA/Padova T1DM simulator patients (i.e. ten adults, ten adolescents, and ten children) during a fasting‐night scenario and in a hybrid closed‐loop scenario including three meals. The theoretical results are assessed by the simulations on a large cohort of virtual patients and encourage clinical trials.Inspec keywords: biochemistry, medical control systems, blood, diseases, medical computing, closed loop systems, biomedical equipment, state feedback, patient treatment, patient monitoring, biomedical measurement, physiological models, sugarOther keywords: fasting‐night scenario, hybrid closed‐loop scenario, hypoglycaemia‐free artificial pancreas project, blood glycaemia, euglycaemia, type‐1 diabetes, control algorithm, guaranties hypoglycaemia avoidance, pragmatic clinical practice, state feedback control law, required hyperglycaemia correction bolus, rigorous proof, control‐law, glucose concentration error, hypo‐free strategy control     

Positive sliding mode control for blood glucose regulation

Biological systems involving positive variables as concentrations are some examples of so-called positive systems. This is the case of the glycemia–insulinemia system considered in this paper. To cope with these physical constraints, it is shown that a positive sliding mode control (SMC) can be designed for glycemia regulation. The largest positive invariant set (PIS) is obtained for the insulinemia subsystem in open and closed loop. The existence of a positive SMC for glycemia regulation is shown here for the first time. Necessary conditions to design the sliding surface and the discontinuity gain are derived to guarantee a positive SMC for the insulin dynamics. SMC is designed to be positive everywhere in the largest closed-loop PIS of plasma insulin system. Two-stage SMC is employed; the last stage SMC2 block uses the glycemia error to design the desired insulin trajectory. Then the plasma insulin state is forced to track the reference via SMC1. The resulting desired insulin trajectory is the required virtual control input of the glycemia system to eliminate blood glucose (BG) error. The positive control is tested in silico on type-1 diabetic patients model derived from real-life clinical data.     

Fabrication of Biogenic Silica Nanostructures from Sorghum bicolor Leaves for Food Industry Applications

Silicon - Due to the large production of sorghum, the generation of associated agricultural residues, which contain high contents of silica, is inevitable. Also, these agricultural residues are not...     

Analysis of microporosity and specific vapour sorption by zirconia gel

The surface properties of zirconia gel and its thermal dehydration products obtained in the temperature range 300–1000°C (573–1273 K) were investigated through the adsorption of water, methanol and carbon tetrachloride vapours at 35°C (308 K). The non specific character of carbon tetrachloride makes it a good probe for detecting microporosity in the gel. Hydrophilic centres on the zirconia surface appear to function as favourable adsorption sites for polar water and methanol adsorbate molecule. The high values of the areas obtained from water adsorption for highly hydroxylated samples may be explained by the fact that the smaller polar water molecules can penetrate into narrow pores and interact with the hydroxyl groups located there. The presence of a high concentration of hydroxyl groups in the micropores is evident from the sharp decrease in the methanol uptake by zirconia gel, since methanol is known to interact specifically with hydroxyl groups existing in mesopores or on plane surfaces through hydrogen bonding.     

Smart expansion of target key for more handlers to access multimedia counting-based secret sharing

Multimedia Tools and Applications - The secret sharing scheme is a data security tool to provide safe reliability and robustness for multi-user authentication systems. This work focus on expanding...     

Androgens Upregulate Pathogen-Induced Placental Innate Immune Response

Group B Streptococcus (GBS) is a leading cause of placental infection, termed chorioamnionitis. Chorioamnionitis is associated with an increased risk of neurobehavioral impairments, such as autism spectrum disorders, which are more prominent in males than in female offspring. In a pre-clinical model of chorioamnionitis, a greater inflammatory response was observed in placenta associated with male rather than female fetuses, correlating with the severity of subsequent neurobehavioral impairments. The reason for this sex difference is not understood. Our hypothesis is that androgens upregulate the placental innate immune response in male fetuses. Lewis dams were injected daily from gestational day (G) 18 to 21 with corn oil (vehicle) or an androgen receptor antagonist (flutamide). On G 19, dams were injected with saline (control) or GBS. Maternal, fetal sera and placentas were collected for protein assays and in situ analyses. Our results showed that while flutamide alone had no effect, a decrease in placental concentration of pro-inflammatory cytokines and infiltration of polymorphonuclear cells was observed in flutamide/infected compared to vehicle/infected groups. These results show that androgens upregulate the placental innate immune response and thus may contribute to the skewed sex ratio towards males observed in several developmental impairments resulting from perinatal infection/inflammation.     

Improving the quantum cost of reversible Boolean functions using reorder algorithm

This paper introduces a novel algorithm to synthesize a low-cost reversible circuits for any Boolean function with n inputs represented as a Positive Polarity Reed–Muller expansion. The proposed algorithm applies a predefined rules to reorder the terms in the function to minimize the multi-calculation of common parts of the Boolean function to decrease the quantum cost of the reversible circuit. The paper achieves a decrease in the quantum cost and/or the circuit length, on average, when compared with relevant work in the literature.     

Synthesis,structures, and density functional theory computational study of thiophene‐containing and fluorodecorated imine‐linked polymers

A new series of extended–conjugated and thermally stable thiophene‐containing imine‐linked polymers were synthesized via a Schiff‐base condensation reaction between aryl aldehydes and 2,6‐diaminopyridine building blocks. The backbones of the polymers were functionalized with phenyl, fluorosubstituted phenyl, thienyl, and pyridyl aromatic rings. The successful synthesis was confirmed with spectrochemical characterization techniques, including IR, ¹H‐NMR, ¹³C‐NMR, and elemental analyses. The electronic properties of the polymers were investigated with ultraviolet–visible (UV–vis) absorption spectroscopy; the properties were collected experimentally and calculated with density functional theory (DFT) in the gas phase. The maximum absorption calculated from DFT was higher than the experimental values by about 60 nm; this was attributed to the absence of the solvent effect in the DFT case. The frontier molecular orbital ((HOMO) highest occupied molecular orbital and (LUMO) lowest unoccupied molecular orbital), optical band gap (E_g), and total energy (E_T) values of the optimized structures were calculated. Apparently, there was a significant relation between the number of thiophene rings and the resulting E_g and E_T values. As the number of thiophene rings in the polymer chain increased, E_g and E_T decreased, and the thermal stability of the polymers increased. E_g and the absorption band edges were determined experimentally from the UV–vis and transmittance spectra, respectively. Poly(terthienyl–azomethine–pyridine–azomethine), with the highest thiophene content, had the lowest experimental and calculated E_g values (2.10 and 2.63 eV, respectively). In contrast, upon fluorination, poly[(2,5‐dithienyl–1,4‐difluorobenzene)–azomethine–pyridine–azomethine] exhibited the highest E_g (2.81 eV) and absorption band edges (2.94 eV), whereas the thermal stability decreased to 250 °C. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44331.     

Evaluation of Erosion Corrosion in Liquid–Solid and Liquid–Gas via Experimental Analysis Inside 90° Copper Elbow

Erosion–corrosion experiments of copper elbow were performed by acidified dichromate. Mass transfer coefficient inside 90° copper elbow has been investigated. The results showed that the mass transfer coefficient increases as solution velocity increases in both cases of one- and two-phase flow. The mass transfer coefficient can be related to the solution velocity in case one-phase flow by the following equations:

$$k \, \alpha \, v^{ 0. 4 4}\quad{\text{for\,Sc\,from\,678 to 845}}$$

$$k \, \alpha \, v^{ 0. 3}\quad{\text{for\,Sc\,from\,1040\,to\,1445}}$$

In case of liquid–solid flow

$$k \, \alpha \, v^{ 0. 3 3}$$

In case of liquid–gas flow

$$k \, \alpha \, vg^{ 0. 2 4}$$

The importance of these equations is to understand and predict erosion corrosion inside 90^o copper elbow.

     

New flavonol glycosides from Barbeya oleoides Schweinfurth

Three new flavonol glycosides, 3′,5′ dimethoxymyricetin-4″-O-α-l-rhamnopyranosyl (1–4) β-d-glucopyranoside (1), 3′-methoxyquercetin-4″-O-α-l-rhamnopyranosyl (1–4) β-d-glucopyranoside (2) and 3′-methoxyqurecetin-6″-O-α-l-rhamnopyranosyl (1–6) β-d-glucopyranoside (3), have been isolated from the aerial part of Barbeya oleoides Schweinf., along with twelve known compounds, uvaol (4), ursolic acid (5), corosolic acid (6), arjunolic acid (7), β-sitosterol-3-O-β-d-glucoside (8), (+)–catechin (9), (-)-epicatechin (10), isorhamnetin-4′-O-glucoside (11), arjunglucoside I (12), d-(-)-bornesitol (13), gallocatechin (14) and epigallocatechin (15). Compounds 4–15 were isolated for the first time from Barbeyaceae. Structure elucidation of compounds 1–3 was based on MS and NMR data. The ethyl acetate extract of the stems as well as compounds 5, 6, 14 and 15 showed significant antimicrobial activity, while the ethanol extracts of leaves, stems and compounds 4, 7, 8, 13–15 have dose-dependent spasmolytic action.