On N-wave type systems and their gauge equivalent

The class of nonlinear evolution equations - gauge equivalent to the N-wave equations related to the simple Lie algebra g are derived and analyzed. They are written in terms of the functions S(x,t) satisfying r= rank g nonlinear constraints. The corresponding Lax pairs and the time evolution of the scattering data are found. The Zakharov-Shabat dressing method is appropriately modified to construct their soliton solutions.Comment: 5 pages, LaTeX 2e, revised versio

The influence of fermentation activity and ester producing capacity of yeast strains on the chemical composition and organoleptic characteristics of Gamza wines

The influence of the two technological parameters, temperature (20 °C, 24 °C, 28 °C) and the inoculum amount of the yeast culture (2%, 3%, 4%) on the duration of the alcoholic fermentation and the ester-producing capacity of the Badachoni and the 24-6 strains of Saccharomyces cerevisiae species was studied. The yeast exhibited high fermentation activity. The intensity with which it initiated the process and the time for its completion was in correlation with the studied factors. The strains showed the best activity at 28 °C/4%. Neural networks were applied and mathematical models were derived, properly describing the fermentation process and the change in the total amount of esters in the course of the process, depending on the technological conditions. The rate in the dynamic of the esters during the process was monitored in 4 stages - onset, rapid fermentation, quiet fermentation, and after malolactic fermentation. The maximum quantity of esters was synthesized in the middle of the process. During alcoholic fermentation, the esters followed a tendency to increase with decreasing the temperature, increasing the amount of yeast culture and the time of the process. The Badachoni and the 24-6 strains demonstrated the highest ester-producing capacity under the temperature of 20 °C and with the 4% inoculum of the yeast culture. The Badachoni strain quantitatively produced more esters than the 24-6 strain. No strict correlation was found between the amount of esters and the organoleptic properties of the wines. The sample containing the most esters had the highest tasting score only in the variants of the 24-6 strain

Assessment of Operative Risk in Colorectal Oncologic Surgery

The objective of the present study is to elaborate a prognostic index for qualitative assessment of the operative risk in the surgical treatment of colorectal cancer (CRC).The documentation of 150 CRC patients, 91 males and 59 females, operated on in the Clinic of Surgery, Marko A. Markov Specialized Hospital of Oncological Diseases of Varna during the period from June 2008 till April 2009 was analyzed. Mean patients` age was 64,2 years (range, 34-84 years).Seventy patients presented with colon cancer, 76 - with rectum cancer while 4 patients presented with multiple tumour localizations. The risk factors included the following: patient`s age and gender; ASA stage; CRC localization according to ICD of WHO; surgical procedure according to OPCS4 system; emergency; CRC stage according to TNM classification; resection type, and hematocrit level. There were 55 patients with TNM stage I, 80 patients with TNM stages II-III, and 15 patients with TNM stage IV. The most common interventions were anterior resection (in 48 patients), right hemicolectomy (in 41 patients), and sigmoidectomy (in 23 patients). Thirty-day operative lethality rate was zero.The created data-base can successfully be used for the purposes of CRC prognostication with the patients forwarded to operative treatment

Investigation of Different Regimes of Beer Fermentation with Free and Immobilized Cells

Three different kinetic models – Monod’s model, Monod’s model with substrate inhibition, and Monod's model with substrate and product inhibition were developed for studying of beer fermentation with free and immobilized cells at different main fermentation and maturation temperatures. The most accurate model was Monod's model with substrate and product inhibition. It showed that maturation temperature had no effect on primary metabolism but it affected significantly the secondary metabolites production. In regard to carbonyl compounds and esters, the increase in maturation temperature led to different trends for free and immobilized cells. Regarding the higher alcohols, the increase in maturation temperature resulted in increase in their yield coefficients for both immobilized and free cells. A sensory evaluation of beers produced with free and immobilized cells were also carried out and the results showed similar results for two beer types

Investigation of Fermentation Regimes for the Production of Low-alcohol and Non-alcohol Beers

The combination of modified mashing method and arrested fermentation for the production of low-alcohol and non-alcohol beers was studied. Therefore, five regimes for fermentation of wort with reduced fermentable sugar content with top-fermenting yeast strain at low temperatures and pitching rates were investigated. According to the fermentation dynamic results the decrease in the fermentation temperature from 10 °C to 5 °C at pitching rate of 109 Colony Forming Units cm−3 ( CFU cm−3 ) led to significantly reduced concentrations of ethanol and secondary metabolites in beer. The temperature decrease from 10 °C to 7 °C at pitching rate of 107 CFU cm−3 resulted in a decrease in the alcohol concentration and increase in all the secondary metabolite concentrations except for the vicinal diketones concentration. Data show that yeast biomass does not grow at 5 °C and at inoculum concentration of 107 CFU cm−3, which makes fermentation impossible. Fermentation kinetics using Monod's model supplemented with product inhibition was also investigated. Up to 1.7 % of alcohol accumulates in the beer in some of the variants within 7 days. At low fermentation temperatures, yeast biomass utilizes part of the substrate to maintain its vital activity under stress fermentation conditions, which leads to a reduction in the amount of alcohol synthesized. The synthesis and reduction of the secondary metabolites was delayed compared to conventional beer fermentation. The sensory evaluation of the beers produced showed that the most appealing beer was the one produced at 10 °C and pitching rate of 109 CFU cm−3

Growth kinetics of probiotic lactobacilli strains cultivated in a laboratory bioreactor with stirring

Batch cultivation in a laboratory bioreactor with stirring of the lactobacilli strains with probiotic properties Lacticaseibacillus casei ssp. casei G17 and Lacticaseibacillus casei ssp. rhamnosus G16 isolated from pink blossom of Rosa damascena Mill was conducted. The changes in the concentration of viable cells were monitored. The growth kinetics was modeled applying the classic and modified logistic curve model and the maximum specific growth rate (μm) of the studied strains was determined. The classical model of the logistic curve showed higher μm for Lacticaseibacillus casei ssp. casei G17 - 0.133 h-1, compared to Lacticaseibacillus casei ssp. rhamnosus G16 - 0.120 h-1, while the modified logistic curve model predicted comparable maximum growth rates of 0.105 h-1 and 0.101 h-1 for Lacticaseibacillus casei ssp. casei G17 and Lacticaseibacillus casei ssp. rhamnosus G16, respectively. Lacticaseibacillus casei ssp. casei G17 was characterized by a shorter induction period (τa = 0.72 h) and a higher adaptation rate constant (k0 – 0.390 h-1) compared to Lacticaseibacillus casei ssp. rhamnosus G16 (τa=1.66 h; k0=0.110 h-1). The established kinetic parameters show that Lacticaseibacillus casei ssp. rhamnosus G16 needs the addition of growth factors in the fermentation medium that will help to optimize its composition for scaling up the fermentation process

Tehnike minimalne obrade za proizvodnju i čuvanje hrane prilagođene individualnim potrebama

Tailor-made foods, also known as foods with programmable properties, are specialised systems with unique composition prepared by different methods, using the known mechanisms of action of their bioactive ingredients. The development of tailor-made foods involves the evaluation of individual components, including bioactive substances derived from waste products of other productions, such as essential oils. These components are evaluated both individually and in combination within food compositions to achieve specific functionalities. This review focuses on the application of minimal processing technologies for the production and preservation of tailor-made foods. It examines a range of approaches, including traditional and emerging technologies, as well as novel ingredients such as biomolecules from various sources and microorganisms. These approaches are combined according to the principles of hurdle technology to achieve effective synergistic effects that enhance food safety and extend the shelf life of tailor-made foods, while maintaining their functional properties. §Paper was presented at the 11th Central European Congress on Food and Nutrition CEFood2022, Čatež ob Savi, Slovenia, 27-30 September 2022Hrana prilagođena individualnim potrebama, poznata i kao hrana s prilagođenim svojstvima, je posebno pripremljena hrana jedinstvenog sastava, dobivena različitim metodama koje se zasnivaju na dobro poznatim mehanizmima djelovanja biološki aktivnih sastojaka. Razvoj takve hrane obuhvaća procjenu pojedinih sastojaka, uključujući biološki aktivnih spojeva izoliranih iz otpada nastalog u proizvodnji, poput eteričnih ulja. Ti su spojevi ispitani pojedinačno i u kombinaciji sa sastojcima hrane, u svrhu razvoja određenih funkcionalnih svojstava. U fokusu ovog revijalnog prikaza je primjena tehnika minimalne obrade za proizvodnju i čuvanje hrane prilagođene jedinstvenim potrebama. Razmotreni su različiti pristupi, uključujući tradicionalne i nove tehnologije, te novi sastojci, poput biomolekula što potječu iz različitih izvora i mikroorganizama. Ti su pristupi kombinirani na principu tehnologije preprekama, za uspješno postizanje sinergijskog učinka koji poboljšava sigurnost i produljuje vrijeme skladištenja hrane, dok istovremeno zadržava njezina funkcionalna svojstva

Prognostic significance of Epidermal Growth factor receptor in colon cancer patients on surgical treatment

Recently, pathological expression of epidermal growth factor receptor (EGFR) is increasingly used in the diagnosis of various epidermal tumours. The aim of this study is to analyze the role of EGFR in comparison to p53 as a prognostic marker in patients with colon cancer who undergo surgical treatment.Two types of immunohistochemical examinations (for EGFR and p53) have been performed in 120 patients with colon cancer histologically verified by using of hematoxylin-eosin staining.Our results clearly demonstrate that EGFR expression is present in 18 patients (in 15% of the cases). It occurs much more often in the patient with TNM stage II and especially in those with TNM stage III and relatively more frequently in the patients aged between 51 and 70 years and presenting with a moderately differentiated tumour. Besides, this expression immediately relates to a recurrence of the disease and worsened clinical course. There exists a correlation between the enhanced expression of EGFR and that of p53. Because of the small sample, our results are not statistically significant.EGFR can serve as an independent prognostic factor and indicator of more common recurrences of the disease, worse quality of life and poorer prognosis in colon cancer patients. Further intensive collaboration between coloproctologists and pathologists is needed to improve the individualized surgical behaviour in such patients