Nb effect in the nickel oxide-catalyzed low-temperature oxidative dehydrogenation of ethane

A method for the preparation of NiO and Nb–NiO nanocomposites is developed, based on the slow oxidation of a nickel-rich Nb–Ni gel obtained in citric acid. The resulting materials have higher surface areas than those obtained by the classical evaporation method from nickel nitrate and ammonium niobium oxalate. These consist in NiO nanocrystallites (7–13 nm) associated, at Nb contents >3 at.%., with an amorphous thin layer (1–2 nm) of a niobium-rich mixed oxide with a structure similar to that of NiNb₂O₆. Unlike bulk nickel oxides, the activity of these nanooxides for low-temperature ethane oxidative dehydrogenation (ODH) has been related to their redox properties. In addition to limiting the size of NiO crystallites, the presence of the Nb-rich phase also inhibits NiO reducibility. At Nb content >5 at.%, Nb–NiO composites are thus less active for ethane ODH but more selective, indicating that the Nb-rich phase probably covers part of the unselective, non-stoichiometric, active oxygen species of NiO. This geometric effect is supported by high-resolution transmission electron microscopy observations. The close interaction between NiO and the thin Nb-rich mixed oxide layer, combined with possible restructuration of the nanocomposite under ODH conditions, leads to significant catalyst deactivation at high Nb loadings. Hence, the most efficient ODH catalysts obtained by this method are those containing 3–4 at.% Nb, which combine high activity, selectivity, and stability. The impact of the preparation method on the structural and catalytic properties of Nb–NiO nanocomposites suggests that further improvement in NiO-catalyzed ethane ODH can be expected upon optimization of the catalyst.     

Automated detection of exudates in colored retinal images for diagnosis of diabetic retinopathy

Medical image analysis is a very popular research area these days in which digital images are analyzed for the diagnosis and screening of different medical problems. Diabetic retinopathy (DR) is an eye disease caused by the increase of insulin in blood and may cause blindness. An automated system for early detection of DR can save a patient's vision and can also help the ophthalmologists in screening of DR. The background or nonproliferative DR contains four types of lesions, i.e., microaneurysms, hemorrhages, hard exudates, and soft exudates. This paper presents a method for detection and classification of exudates in colored retinal images. We present a novel technique that uses filter banks to extract the candidate regions for possible exudates. It eliminates the spurious exudate regions by removing the optic disc region. Then it applies a Bayesian classifier as a combination of Gaussian functions to detect exudate and nonexudate regions. The proposed system is evaluated and tested on publicly available retinal image databases using performance parameters such as sensitivity, specificity, and accuracy. We further compare our system with already proposed and published methods to show the validity of the proposed system.     

Biochemical characterization of wheat straw cell wall with special reference to bioactive profile

The core objective of the current study was to extract and characterize the wheat straw cell wall for its nutritional and bioactive profile. For the purpose, four different wheat straw varieties namely Ujala-16, Johar-16, Gold-16, and Galaxy-13 were procured from Ayub Agriculture Research Institute, Faisalabad, Pakistan. The whole research was conducted in three different phases. In first phase, nutritional composition and mineral profile of straw of different wheat varieties were determined. In second phase, wheat straw cell wall of different varieties was isolated and characterized for its important bioactive constituents, such as lignin, cellulose, hemicelluloses, phytosterol, and policosanol (PC) content. Results showed that straw of different wheat varieties contained 7.75–9.24, 3.98–5.06, 3.43–3.98, and 1.60–2.24 g/100 g moisture, ash, protein, and fat contents, respectively, whereas potassium, calcium, phosphorus, and magnesium were 1.19–2.03, 0.10–0.79, 0.10–0.98, 0.03–0.98 ppm, respectively. Moreover, lignocellulosic mass: cellulose 37.75–38.18 g/100 g raw material, lignin 15.67–16.07 g/100 g raw material, hemicelluloses 28.25–28.98 g/100 g raw material, was present in wheat straw and varied significantly among different varieties. In addition, phytosterol ranged from 854 to 1176 mg/kg in straw of different wheat cultivars, whilst PC from 196.09 to 236.48 mg/kg. Conclusively, wheat straw was an excellent source of many important bioactive moieties especially lignocelluloses and could have functional use.     

Smart Designing of Tragacanth Gum by Graft Functionalization for Advanced Materials

Tragacanth gum is a novel polysaccharide which offers interesting features in terms of high hydrophilicity, good biocompatibility, and biodegradability. The engineering of hydrogels requires careful designing of their macromolecular structures so that desirable features may be incorporated into the material. Graft polymerization has come up as an interesting approach to develop molecules for drug delivery, wound care systems, and infection‐resistant materials. The most important aspect of graft functionalization is the proper control over physico‐chemical properties of the grafted matrix. The extent of functionalization may be governed by the grafting parameters and may lead to the chemical designing of the molecule in a controlled manner. This opens up enormous possibilities of developing materials for a wide range of applications as advanced materials.     

Nutraceutical and Functional Scenario of Wheat Straw

In the era of nutrition, much focus has been remunerated to functional and nutraceutical foodstuffs. The health endorsing potential of such provisions is attributed to affluent phytochemistry. These dynamic constituents have functional possessions that are imperative for cereal industry. The functional and nutraceutical significance of variety of foods is often accredited to their bioactive molecules. Numerous components have been considered but wheat straw and its diverse components are of prime consideration. In this comprehensive dissertation, efforts are directed to elaborate the functional and nutraceutical importance of wheat straw. Wheat straw is lignocellulosic materials including cellulose, hemicellulose and lignin. It hold various bioactive compounds such as policosanols, phytosterols, phenolics, and triterpenoids, having enormous nutraceutical properties like anti-allergenic, anti-artherogenic, anti-inflammatory, anti-microbial, antioxidant, anti-thrombotic, cardioprotective and vasodilatory effects, antiviral, and anticancer. These compounds are protecting against various ailments like hypercholesterolemia, intermittent claudication, benign prostatic hyperplasia and cardiovascular diseases. Additionally, wheat straw has demonstrated successfully, low cost, renewable, versatile, widely distributed, easily available source for the production of biogas, bioethanol, and biohydrogen in biorefineries to enhance the overall effectiveness of biomass consumption in protected and eco-friendly environment. Furthermore, its role in enhancing the quality and extending the shelf life of bakery products through reducing the progression of staling and retrogradation is limelight of the article.     

Antioxidant Activity of Sesame (Sesamum indicum L.) Cake Extract for the Stabilization of Olein Based Butter

This study investigated the effect of ethanolic sesame cake extract on oxidative stabilization of olein based butter. Fractionation of cream was performed by the dry fractionation technique at 10 °C, ethanolic sesame cake extract (SCE) was incorporated into olein butter at three different concentrations; 50, 100, 150 ppm (T₁, T₂, T₃) and compared with a control. The total phenolic content of SCE was 1.72 (mg gallic acid equivalent g^?1 dry weight). The HPLC characterization of ethanolic sesame cake revealed the presence of antioxidant substances viz. sesamol, sesamin and sesamolin in higher extents. The DPPH free radical scavenging activity of SCE was 83 % as compared to 64 and 75 % in BHA and BHT. Fractionation of milk fat at 10 °C significantly (p < 0.05) influenced the fatty acid profile of olein and stearin fractions from the parent milk fat. Concentration of oleic acid and linoleic acid in olein fraction was 29.62 and 33.46 % greater than the parent milk fat. The loss of C18:1 in 90 days stored control and T₃ was 24.37 and 3.58 %, respectively, 58 % C18:2 was broken down into oxidation products over 8.55 % loss in T₃. The peroxide value of control, T₁, T₂, BHT and T₃ in the Schaal oven test was 8.59, 8.12, 5.34, 4.52 and 2.49 (mequiv O₂/kg). The peroxide value and anisidine value of 3 months stored control and T₃ were 1.21, 0.42 (mequiv O₂/kg) and 27.25, 13.25, respectively. The concentration of conjugated dienes in T₃ was substantially less than the control. The induction period of T₃ was considerably higher than BHT with no difference in sensory characteristics (p > 0.05). Ethanolic SCE can be used for the long‐term preservation of olein butter, with acceptable sensory characteristics.     

Onion: Nature Protection Against Physiological Threats

Onion (Allium cepa L.) is found in various regions of Europe, North America, Asia, and Africa. It is one of the classic examples of Allium species used not only for culinary preparations but also for medicinal purposes. Onion with a variety of purposes is often used as a raw material in many dishes and accepts almost all of the traditions and culture. Owing to its storage characteristics and durability of shipping, onions have been traded more widely than most vegetables. The pungent fractions of garlic are mostly sulfur-containing moieties while its two chemical groups have marked effect on human health. These are flavonoids and ALK (EN)-based cysteine sulfoxides (ACSOs). Compounds in onions have been reported with a range of health benefits, including anticancer properties, antiplatelet activity, antithrombotic activity, antiasthmatic activity, and antibiotic effects.     

Tomato (Solanum lycopersicum) Carotenoids and Lycopenes Chemistry; Metabolism,Absorption, Nutrition,and Allied Health Claims—A Comprehensive Review

Tomato (Solanum lycopersicum) is one of the most essential herbaceous plants that have been probed against various life sight related disorders owing to array of phytochemicals. It is important source of vitamin C, potassium, folic acid, and carotenoids, such as lycopene. Carotenoids are the pigments synthesized during fruit ripening and responsible for the final red color of the tomato. Consumption of tomato and tomato-based products contribute to the absorption of carotenoids and lycopenes in human serum. Lycopene is chemically acyclic carotene with 11 conjugated double bonds, normally in transconfiguration while isomerization occur in blood plasma for its better absorption. It has ability for adenosine deaminase inhibition that plays important role in the regression of tumor. Tomato also contain other active compounds, namely, neoxanthin, lutein, α-cryptoxanthin, α-carotene, β-carotene, cyclolycopene, and β-carotene 5, 6-epoxide. These components provide synergistic effect against various threats but still need further attention of the researchers. Both in vitro and in vivo studies have elucidated the potential of tomato against variety of metabolic syndromes. Latest research highlights the relationship between consuming tomato and its products with reduced risk of various maladies like obesity, hyperglycemic and hypercholesterolemic attributes, cardiovascular disorders, and cancer insurgences. Moreover, tomato and its bioactive components hold potential to become effective modules in diet-based regimens; however, integrated research and meta-analysis are still required to enhance meticulousness.