25 research outputs found
Yeast-Lactobacillus Co-Cultures as in situ Ethanol Producers for Flavor Ester Synthesis using Lipase in Fermented Milks
Background and objective: Nowadays, novel biotechnological methods are preferred for flavoring productions since traditional methods include disadvantages. The aim of this study was to assess in situ biosynthesis of natural fruity flavors in fermented milks using microbial co-cultures and lipase enzyme.
Materials and methods:
Trans esterification of milk fats with ethanol was carried out to develop fruity flavors in ultra-high-temperature whole milks using lipase of Palatase coupled with ethanol fermentation. Kluyveromyces marxianus NCYC 1425 was used to produce in situ ethanol in co-cultures with Lactobacillus fermentum PCC or Lactobacillus paracasei L26. Effects of co-culturing on cell viability and fermentation progress were assessed using enumeration of viable cells and measurement of pH in samples at 0, 24 (Palatase addition) and 48 h (end of fermentation). Headspace solid phase microextraction-gas chromatography (SPME)-MS/FID was used for ester, ethanol and free fatty acid analyses at the beginning and end of the fermentation. Standard curve of ethanol was used to assess the products in terms of being Halal.
Results and conclusion:
Kluyveromyces marxianus included synergistic effects on Lactobacillus paracasei growth as well as antagonistic effects on Lactobacillus fermentum growth. Antimicrobial effects were seen in Kluyveromyces marxianus-Lactobacillus paracasei co-cultures when Palatase was added. Palatase significantly increased ester levels of the fermented samples. The co-cultures did not include significant differences in shorter chain ester levels (esters of 4-7 carbon chain fatty acids); in contrast, Kluyveromyces marxianus- Lactobacillus fermentum resulted in higher levels of longer chain esters. Although the Kluyveromyces marxianus cultures resulted in higher ester levels compared to that its co-cultures did, the cultures can be used as appropriate adjunct cultures with Lactobacillus cultures to boost flavor ester synthesis. This flavor synthesis can be an appropriate alternative for artificial flavoring agents
Evaluation of Staggered Osteotomy in Surgical Treatment of Trigonocephaly
Introduction: undiagnosed metopic synostosis (Trigonocephaly) have many complications for infants such as Brain damage and cognitive & behavioral disorders, they also result in poor aesthetic features. There are many surgical techniques for this malformation which have their advantages and disadvantages; but with this new method (staggered osteotomy) we can solve some of these problems and minimize damages.Materials and Methods:  In this study, 20 infants with metopic synostosis underwent surgery in Mofid Children Hospital, Tehran.  The minimum age of our patients was 4 months and the maximum was 9 months with an average of 6.72 months. Their diagnosis was confirmed with clinical symptoms & signs also with CTscan and paraclinical findings. Age and weight before and after surgery and anthropometric indices including: biparietal width and frontal width were recorded and reported.Results: We found significant differences in anthropometric indices before & after surgery such as lowering of biparietal width after surgery and elevation of frontoparital index after surgery. Since in this procedure, we don’t separate the frontal bone segments and it keeps its frame, less plaques and screws are needed which will decrease the costs of surgery and the surgical time is much less than other techniques. Last but not the least, the satisfactions of parents were high and there was no need for secondary surgery.Conclusion:Based on all the perfect results we got , it is safe to say that staggered osteotomy as a surgical method for correction of trigonocephaly is useful and we can use it as a new method in correction of  metopic synostosis
Current-excitation based ΔR-to-frequency converter for resistive sensors
This paper presents a relaxation oscillator-based high-resolution resistance measurement system. The proposed signal conditioning circuit utilizes a half-bridge topology with a bidirectional current excitation. The circuit modulates the incremental change in the sensor resistance in the form of a change in the frequency of the relaxation oscillator. The baseline resistance of the sensor is automatically compensated using a digital potentiometer at the beginning of the measurement cycle. The proposed circuit is analyzed in detail by considering the non-idealities of the circuit components. The design consideration is provided for different components. A prototype PCB of the proposed circuit is developed. The results show that the proposed circuit can provide a signal-to-noise ratio of 80 dB for a wide-range incremental change in the sensor resistance up to 500 kΩ with an error of less than ± 1%. The developed board is tested with humidity sensors. The result confirms the efficacy of the proposed circuit for a wide measurement range
High Voltage Generators,
Abstract � high voltage synchronous generators known as powerformers, by changing stator configuration and their winding compared to conventional generator could generate fit voltage for connecting to transmission lines directly. Because of the innovation in their configuration and complication, fields and consequently reactances calculations would be so difficult by analytical formulas. In this article, numerical method based on finite element method has been used to calculate leakage, d axis and q axis reactances of a sample high voltage generator. Finally a comparison has been made between the results calculated by numerical analysis as well as analytical formulas. 1
High-dose chemotherapy and stem-cell rescue for salvage therapy for relapsed malignant mixed ovarian germ cell tumor: A case report
Background: Malignant ovarian germ cell tumors are rare, and often treatable with surgery and chemotherapy. Few data are available for treatment of platinum-resistant tumors.
Case: A 31Â year old gravida 0 with a 20Â cm pelvic mass was found to have a malignant ovarian germ cell tumor after she underwent debulking surgery. She initially responded to chemotherapy; however her AFP began to rise before all cycles were completed. She underwent additional debulking surgery that was again suboptimal. She was then referred for salvage therapy with high-dose chemotherapy with stem cell transplant, which was successful and she has had no evidence of disease for over two years.
Conclusion: High-dose chemotherapy with stem cell transplant is a viable salvage therapy for patients with platinum-resistant germ cell tumors
Water requirements of urban landscape plants in an arid environment: The example of a botanic garden and a forest park
Creation and conservation of urban parks is challenging in arid environments where daily thermal extremes, water scarcity, air pollution and shortage of natural green spaces are more conspicuous. Water scarcity in the arid regions of Iran is major challenge for water managers. Accurate estimation of urban landscape evapotranspiration is therefore critically important for cities located in naturally dry environments, to appropriately manage irrigation practices. This study investigated two factor-based approaches, Water Use Classifications of Landscape Species (WUCOLS) and Landscape Irrigation Management Program (LIMP), to measure the water demand of two heterogeneous urban landscapes: a botanic garden and a sparse forest park. The irrigation water volume applied was compared with the gross water demand for the period from 2011 to 2013. In this research, WUCOLS estimated the annual water requirement of a botanic garden and a sparse forest park to be 5% and 44% lower, respectively, than LIMP. Comparison of estimated and applied irrigation showed that water savings can be made by the LIMP method. The outcomes of this research stressed the need to modify the irrigation requirements based on effective rainfall throughout the year, rather relying on long-term average data