Evaluation of thermally-dried Kluyveromyces marxianus as baker’s yeast

The aim of the present study was to evaluate the use of thermally-dried Kluyveromyces marxianus as baker’s yeast. Bread samples produced by thermally-dried K. marxianus were compared with samples produced by wet K. marxianus culture and by commercial baker’s yeast. The type of the culture had no effect on loaf weight, loaf volume, specific loaf volume, density or moisture loss, in contrast to pH, total titrable acidity (TTA), and moisture content. The use of thermally-dried K. marxianus resulted in lower pH values and higher TTA, while the bread samples showed higher resistance to spoilage as counts of moulds and yeasts were significantly lower during preservation. The SPME GC/MS analysis of volatiles and the preliminary sensory evaluation showed no significant differences in the profile of aroma-related compounds or overall quality of the tested samples.     

Supporting electrolyte and solvent effects on single-electron double layer capacitance charging of hexanethiolate-coated Au140 nanoparticles

Sequential injections of single electrons (or holes) into the cores of Au(140) hexanethiolate monolayer-protected clusters (MPCs) occur at measurably different electrochemical potentials owing to the extremely small (subattofarad) values of the single MPC capacitance (C(MPC)) of the nanoparticle. The potential increment for each sequential injection is DeltaV = e/C(MPC). The dependence of DeltaV on the concentration of supporting electrolyte (from 1 to 100 mM), measured using square wave voltammetry, is shown to be caused, primarily, by changes in the diffuse double layer component (C(DIFFUSE)) of C(MPC). The dependence of C(DIFFUSE) on r(core), the radius of the nanoparticle, is considered. Additionally, significant changes in the magnitude of the compact double layer component (C(COMPACT), equivalent to the Stern layer) of C(MPC) were induced by adding hydrophobic solvent components such as hexane or dodecane or by introducing hydrophobic electrolyte ions (tetrabutyl-, tetrahexyl-, and tetraoctylammonium, perchlorate, and tetraphenylborate). These changes are interpreted as specific solvation and ion penetration of the hexanethiolate monolayer. For brevity we will refer to these phenomena as solvation/penetration phenomena.     

The effect of process time and temperature on the accumulation of polar compounds in cottonseed oil during deep‐fat frying

The deterioration of oil during successive fryings of potato chips, especially the accumulation of polar compounds, was studied in the temperature range 155–195 °C. The content of polar compounds increased linearly with process time. The analysis of individual polar compounds showed that the products of thermal and oxidative degradation dominated over the products of hydrolytic cleavage as frying proceeded. Dimeric triglycerides increased linearly with process time, while polymerised triglycerides increased exponentially. The rate constants of the degradation reactions increased slightly with temperature, following an Arrhenius‐type equation. Oxidised triglycerides increased with frying time up to 6 h, thereafter remaining constant or increasing further upon prolonged frying. The increase was greater at higher temperature. The products of hydrolytic cleavage were not significantly affected by temperature. Mono‐ and diglycerides increased initially to reach a plateau, while free fatty acids remained almost constant throughout frying. The thermo‐oxidative alterations induced by heating the oil were also measured and compared with those observed during frying at the same temperature. Dimeric and polymerised triglycerides showed higher rates of increase during heating as compared with frying at the same temperature. © 2003 Society of Chemical Industry     

Exploiting Selfishness,Altruism and Common Welfare to Enhance Performance of Routing Protocols for Mobile Ad hoc Networks

Mobile Ad hoc Networks are sensitive to selfish behavior that may occur due to restricted power or other resources. Several approaches have been investigated so far to address this problem. In many of them, upon detection, a selfish node is punished with isolation from network services access and in most cases with no possibility for redemption. In this paper, we show that selfish behavior can be exploited to improve network performance. We modify an existing routing protocol by introducing an altruism coefficient to model the overall satisfaction of every node from the network services. When the altruism coefficient is increased, the selfish behavior is decreased. We extend our approach by introducing a common welfare factor, which actually enforces the nodes to cooperate when the network connectivity is critical. A network simulator is utilized to show the impact of our schemes on the performance of the routing protocol when selfish nodes are present in the network.

     

Screening of the antioxidative and antimicrobial properties of the essential oils of Pimpinella anisetum and Pimpinella flabellifolia from Turkey

The aerial parts of two endemic Pimpinella [Pimpinella anisetum Boiss. & Ball. and Pimpinella flabellifolia (Boiss.) Benth. ex Drude] were hydro-distilled to produce oils in the yields of 2.07% (v/w) and 2.61% (v/w), respectively. The oils were analysed by GC and GC/MS. Twenty-one and nineteen components were identified, representing 99.5% and 99.7% of the oils, respectively. The main compounds of P. anisetum were (E)-anethole (82.8%) and methyl chavicol (14.5%), whereas limonene (47.0%), (E)-anethole (37.9%) and α-pinene (6.0%) were the major constituents of P. flabellifolia. The oils were screened for their possible antioxidant activities by two complementary test systems, namely DPPH free radical-scavenging and β-carotene/linoleic acid systems. In the first case, P. anisetum oil exerted greater antioxidant activity than that of P. flabellifolia oil with an IC₅₀ value of 5.62 ± 1.34 μg/ml. In the β-carotene/linoleic acid test system, the oil of P. anisetum was superior to P. flabellifolia with 70.5% ± 2.86 inhibition rate. Essential oils of the plants studied here were also screened for their antimicrobial activities against six bacteria and two fungi. The oils showed moderate antimicrobial activity against all microorganisms tested.     

Effect of freeze–dried kefir culture on proteolysis in feta-type and whey-cheeses

The effect of freeze–dried kefir culture on the proteolysis of feta-type and whey-cheese was investigated. All nitrogen fractions increased during ripening. Although no significant differences were observed in total nitrogen (TN), the levels of water-soluble nitrogen (WSN), pH 4.4-soluble nitrogen (SN), 12% trichloroacetic acid-soluble nitrogen (TCA-SN) and phosphotungstic acid-soluble nitrogen (PTA-SN) were significantly higher in cheeses produced by freeze–dried kefir culture during the later stages of ripening. Content of total free amino acids (FAA) was significantly affected by freeze–dried kefir starter culture and it was continuously increased in kefir-cheese while, in rennet-cheese it was increased up to 30 days of ripening and then slightly decreased. On the other hand, FAA content continuously decreased in kefir-whey-cheese whereas it increased in whey-cheese. The cheese samples produced by freeze–dried kefir as starter culture were characterised as high-quality products during the preliminary sensory evaluation and they were accepted by the panel. Overall, the use of freeze–dried kefir suggested acceleration of cheese ripening and resulted in improved sensory characteristics.     

Use of OCT Angiography to Diagnose and Manage Atypical Presentations of Macular Telangiectasia Type 2

Macular telangiectasia Type 2 (MacTel) is a bilateral acquired retinal disease characterized by both vascular changes and atrophy of the retina. The purpose of this case series is to highlight the use of optical coherence tomography angiography (OCTA) as a non-invasive imaging modality to distinguish atypical MacTel from other macular conditions with similar presentations. We performed a retrospective review of patients referred to our academic retinal practice with unconfirmed or misdiagnosed MacTel between July 2017 and July 2021. Patients’ OCTA imaging findings were reviewed to guide the appropriate diagnosis and management of atypical MacTel. Fifteen eyes from eight patients were included in this study. Six patients were referred with previous diagnoses of either full-thickness macular hole, lamellar hole, vitreomacular traction (VMT), postoperative cystoid macular edema (CME), or diabetic macular edema (DME). Two patients were referred to us to confirm the diagnosis of MacTel. OCTA revealed telangiectatic vessels in the temporal parafovea of all 15 eyes. OCTA also highlighted previously undiagnosed subretinal neovascularization (SRNV) in seven eyes. OCTA imaging is a valuable imaging modality to distinguish MacTel from other macular conditions, whose treatment courses vary substantially. Due to its ease of use, it holds immense potential in the future as treatments for non-proliferative MacTel emerge.     

The p.Pro482Ala Variant in the CNNM2 Gene Causes Severe Hypomagnesemia Amenable to Treatment with Spironolactone

Renal hypomagnesemia syndromes involving CNNM2 protein pathogenic variants are associated with variable degrees of neurocognitive dysfunction and hypomagnesemia. Here, we report a family with a novel CNNM2 p.Pro482Ala variant, presenting with overt hypomagnesemia and mild neurological involvement (autosomal dominant renal hypomagnesemia 6, HOMG6, MIM# 613882). Using a bioinformatics approach, we showed that the p.Pro482Ala amino acid substitution causes a 3D conformational change in CNNM2 structure in the cystathionin beta synthase (CBS) domain and the carboxy-terminal protein segment. A novel finding was that aldosterone inhibition with spironolactone helped to alleviate hypomagnesemia and symptoms in the proband.     

Reactions of Lucigenin in protic solvents in the presence of amines

Lucigenin (N,N′-dimethyl-9,9′-biacridinium nitrate) 1 on heating under reflux in protic solvents in the presence of amines gives rise to the N,N′-dimethyl-9,9′-biacridylidene 2 (DBA) or protected hemiaminal N-methoxymethyl-9,9′-bi-acridylidene 3 . On the other hand acid hydrolysis and synchronous oxidation of hemiaminal 3 followed by reaction of monomethyl-biacridinium nitrate 4 with sodium hydroxide in methanol or water leads to biacridine 5 (overall yield ca. 33%).     

Two-Photon Polymerization Lithography for Optics and Photonics: Fundamentals,Materials, Technologies,and Applications

The rapid development of additive manufacturing has fueled a revolution in various research fields and industrial applications. Among the myriad of advanced 3D printing techniques, two-photon polymerization lithography (TPL) uniquely offers a significant advantage in nanoscale print resolution, and has been widely employed in diverse fields, for example, life sciences, materials sciences, mechanics, and microfluidics. More recently, by virtue of the optical transparency of most of the resins used, TPL is finding new applications in optics and photonics, with nanometer to millimeter feature dimensions. It enables the minimization of optical elements and systems, and exploration of light-matter interactions with new degrees of freedom, never possible before. To review the recent progress in the TPL related optical research, it starts with the fundamentals of TPL and material formulation, then discusses novel fabrication methods, and a wide range of optical applications. These applications notably include diffractive, topological, quantum, and color optics. With a panoramic view of the development, it is concluded with insights and perspectives of the future development of TPL and related potential optical applications.