Our first experience in laparoscopic colorectal operations

Purpose: It has been almost 23 years since the first laparoscopic-assisted right hemicolectomy was done when the surgeons in our institution started doing laparoscopic colorectal operations mainly for malignant diseases. The aim of this communication was to present the beginning of the laparoscopic colorectal operations in St. Naum University Clinic of Surgical Diseases in Skopje, Macedonia.Material and methods: Twenty patients with colorectal adenocarcinoma were laparoscopically operated during the period from December 2012 to June 2013. Eleven of them were men and the rest women at a mean age of 58 years. Eight of them were rectal cancers, 3 were cancers of the rectosigmoid and the rest 9 were sigmoid adenocarcinomas. The patients were operated with 4 ports (sigmoid cancer) and 5 ports (rectum). Medial-to-lateral approach was used in all the cases. Tumour location dictated whether high or low ligation of inferior mesenteric artery (IMA) was done. Double stapler technique was applied for distal resection and anastomosis creation.Results: Mean operating time was 315 min. There were no perioperative and early postoperative deaths. One patient was reoperated early at the same operating day for mesenteric venous bleeding. There was one case of anastomotic leakage and a laparotomy was done with temporary colostomy. One unit of blood was given to five patients due to perioperative bleeding. Mean length of hospital stay was six days. Per oral nutrition started at day 2. Mean bowel function returned after 3,5 days. There were two seromas of the minilaparotomy wounds and no cases of surgical site infection. Selected cases of sigmoid and rectal cancer were suitable for beginning of learning the laparoscopic colorectal resection technique. The long operating time was understandable due to the steep learning curve. Conclusion: Laparoscopic colorectal surgery is safe and oncologically routine surgical method. It is widely used for many benign colorectal diseases, too. Prolonged learning of this technique should not be discouraging

A MOS-based Dynamic Memetic Differential Evolution Algorithm for Continuous Optimization: A Scalability Test

Continuous optimization is one of the areas with more activity in the field of heuristic optimization. Many algorithms have been proposed and compared on several benchmarks of functions, with different performance depending on the problems. For this reason, the combination of different search strategies seems desirable to obtain the best performance of each of these approaches. This contribution explores the use of a hybrid memetic algorithm based on the multiple offspring framework. The proposed algorithm combines the explorative/exploitative strength of two heuristic search methods that separately obtain very competitive results. This algorithm has been tested with the benchmark problems and conditions defined for the special issue of the Soft Computing Journal on Scalability of Evolutionary Algorithms and other Metaheuristics for Large Scale Continuous Optimization Problems. The proposed algorithm obtained the best results compared with both its composing algorithms and a set of reference algorithms that were proposed for the special issue

Quality of Honey Bee Bread Collected in Spring

Pollen is the only source of protein that honey bees collect from nature. It is very important for the development of brood, and consequently, for the development of the colony. Honey bee bread is the pollen which the bees collect from flowers and store in honeycomb cells. Honey bee bread has a modified structure due to the fermentation process under the influence of enzymes it passes through. For this study, ten honey bee colonies were selected. Honey bee bread was sampled from the combs. The quality of pollen and honey bee bread was determined by the chemical composition, using standard methods used in food analysis. Total nitrogen was determined by Kjeldahl method. Micro- and macroelements were determined by spectrophotometric method. The pollen collected from two sites had rich protein content (29.93 % and 27.63 % on average)

Specifics of granite-based stone micro-cutting mechanism

В даній роботі показані результати дослідження, що були проведені на Машинобудівному факультеті в м. Белграді в області мікрорізання крихких матеріалів. Проаналізована взаємодія між алмазним зерном і мармуром та гранітом, що обробляються. Експериментально установлена зміна нормальної складової сили різання у функції швидкості різання і глибини проникнення при мікрорізанні на двох видах мармуру та граніту з родовищ в Республіці Сербії. На основі залишків на граніті і тріщин, що виникли, установлена критична глибина проникнення зерна, при якій виникає крихке руйнування. Наведені дослідження мають допомогти оптимізації процесу шліфування і полірування, які є домінуючими технологіями завершальної обробки граніту.The paper shows the results of investigations performed in the brittle materials micro-cutting at the Faculty of Mechanical Engineering, Belgrade University. The interactions between a single diamond grain and the machined marble and granite are analyzed. The change in the normal cutting force as a function of cutting speed and grain penetration depth was experimentally established in micro-cutting of two types of stone, marble and granite, originating from Serbia. Based on the grain traces on granite and the generated cracks, the critical grain penetration depth for the formation of brittle fracturing was established. The investigations mentioned should assist in the optimization of the grinding and polishing processes as technologies dominant in the granite finishing.В данной работе показаны результаты исследования, проводящиеся на Машиностроительном факультете в г. Белграде в области микрорезания хрупких материалов. Здесь проанализировано взаимодействие между алмазным зерном и обрабатывающимся мрамором и гранитом. Экспериментально установлено изменение нормальной составляющей силы резания в функции скорости резания и глубины проникновения при микрорезании на двух видах мрамора и гранита из местонахождений в Республике Сербии. На основании следов на граните и возникших трещин установлена критическая глубина проникновения зерна, при которой возникает хрупкое разрушение. Указанные исследования должны помогать оптимизации процесса шлифования и полировки, являющихся доминирующими технологиями окончательной обработки гранита

Probing the structure and dynamics of molecular clusters using rotational wavepackets

The chemical and physical properties of molecular clusters can heavily depend on their size, which makes them very attractive for the design of new materials with tailored properties. Deriving the structure and dynamics of clusters is therefore of major interest in science. Weakly bound clusters can be studied using conventional spectroscopic techniques, but the number of lines observed is often too small for a comprehensive structural analysis. Impulsive alignment generates rotational wavepackets, which provides simultaneous information on structure and dynamics, as has been demonstrated successfully for isolated molecules. Here, we apply this technique for the firsttime to clusters comprising of a molecule and a single helium atom. By forcing the population of high rotational levels in intense laser fields we demonstrate the generation of rich rotational line spectra for this system, establishing the highly delocalised structure and the coherence of rotational wavepacket propagation. Our findings enable studies of clusters of different sizes and complexity as well as incipient superfluidity effects using wavepacket methods.Comment: 5 pages, 6 figure

Advantages and disadvantages of non-starter lactic acid bacteria from traditional fermented foods: potential use as starters or probiotics

Research Areas: Food Science & TechnologyTraditional fermented foods are a significant source of starter and/or non-starter lactic acid bacteria (nsLAB). Moreover, these microorganisms are also known for their role as probiotics. The potential of nsLAB is huge; however, there are still challenges to be overcome with respect to characterization and application. In the present review, the most important steps that autochthonous lactic acid bacteria isolated from fermented foods need to overcome, to qualify as novel starter cultures, or as probiotics, in food technology and biotechnology, are considered. These different characterization steps include precise identification, detection of health-promoting properties, and safety evaluation. Each of these features is strain specific and needs to be accurately determined. This review highlights the advantages and disadvantages of nsLAB, isolated from traditional fermented foods, discussing safety aspects and sensory impact.info:eu-repo/semantics/publishedVersio

Duvan chvarci : product characterization and comparison between traditional and industrial production

Research Areas: Food Science & TechnologyThis research aimed to investigate and compare traditional products called “duvan chvarci” produced using pork meat and fat, originated from local households and industries. Physical and chemical analysis demonstrated differences among the examined products, mostly in total chloride content and TBARS values. Samples collected at local households showed finer color (higher lightness and yellowness) and sensory properties (rated as “extremely acceptable”), while industrial products were rated between “very acceptable” and “extremely acceptable“. Microbiological analysis exhibited that enterobacteria, coagulase-positive staphylococci, Salmonella spp., Shigella spp., and fungi were absent from all meat products. Dominant microbiota was identified as Lactobacillus spp. and Staphylococcus spp. All tested isolates showed γ-haemolysis on blood agar plates. Tested Staphylococcus spp. were sensitive to novobiocin while Lactobacillus isolates demonstrated sensitivity to ampicillin, chloramphenicol, clindamycin, erythromycin, tetracycline, gentamycin, and streptomycin. None of the tested isolates showed full resistance to antibiotics. Overall, results indicated that duvan chvarci is a microbiologically safe product and provided the initial evidence regarding the physical, chemical, technological, and sensory properties of this widely consumed product in the Balkans.info:eu-repo/semantics/publishedVersio

Serbian traditional goat cheese : physico-chemical, sensory, hygienic and safety characteristics

Research Areas: MicrobiologyThis research project aimed to investigate the physico-chemical, sensory, hygienic and safety characteristics of raw goat milk, whey, brine and traditional goat cheese during the ripening period of 28 days. Physico-chemical parameters included the determination of dry matter, fat, ash, protein, pH, water activity and NaCl content. The presence of Enterobacteriaceae and fungi was estimated on milk and cheese samples, and a sensory panel evaluated the products’ features and acceptability during ripening. The results show that the cheese under study belongs to the acid full-fat cheese group. A consumer panel attributed high scores to the goat cheese, until the 21st day of ripening. After this period, the overall features altered significantly, including augmented bitterness, odor intensification and the development of molds on the surface. The presence of fungi, associated with Enterobacteriaceae, suggests that the hygiene of the production processes needs to be improved. Regarding microbial safety, the detection of putative pathogens and antibiotic resistances recommend an active surveillance of traditional foods to avoid foodborne infections and/or the dissemination of resistant microorganisms along the food chaininfo:eu-repo/semantics/publishedVersio

Improving metaheuristic performance by evolving a variable fitness function.

In this paper we study a complex real world workforce scheduling problem. We apply constructive search and variable neighbourhood search (VNS) metaheuristics and enhance these methods by using a variable fitness function. The variable fitness function (VFF) uses an evolutionary approach to evolve weights for each of the (multiple) objectives. The variable fitness function can potentially enhance any search based optimisation heuristic where multiple objectives can be defined through evolutionary changes in the search direction. We show that the VFF significantly improves performance of constructive and VNS approaches on training problems, and ¿learn¿ problem features which enhance the performance on unseen test problem instances