Турбідиметричний моніторинг розділення фаз у водних розчинах термореактивних полімерів

У роботі представлено метод експериментального визначення мутності розчину термореактивних полімерів в області об'ємного фазового переходу. Метод заснований на вимірюванні інтенсивностей світлових потоків: ослабленого і зворотно розсіяного зразком. Розроблений нами турбідиметр, на відміну від промислових приладів такого типу, оснащений термостатом, що дозволяє вивчати залежність мутності розчину від його температури. Прилад працює в автоматичному режимі, значення освітленості та температури від цифрових датчиків оброблюються мікроконтролером і передаються по протоколу RS-232 в USB-порти персонального комп'ютера. Похибка вимірювання освітленості не перевищує 0.1 люкс, точність вимірювання температури складає ± 0.1 °C. В роботі продемонстровано приклад використання турбідиметру для вивчення фазового переходу першого роду у 2 мас. % водному розчині гідроксипропілцелюлози за наявності (відсутності) іонів NaCl. Висловлено припущення, що золь-гель перехід у дослідженому розчині обумовлений набуханням полімерних клубків та подальшою їх агрегацією. Зміщення температури фазового переходу пояснюється додатковим набуханням полімерних клубків через екранування електростатичної взаємодії мономерів у присутності іонів NaCl. Показано, що інтенсивність зворотно розсіяного світла відображає кінетику утворення гелевої сітки, що дає можливість встановити кінцеві розміри її агрегатів.A method for the experimental determination of turbidity in thermoresponsive polymer solutions is presented. The method is based on measuring the intensity of light streams: weakened and backscattered from the sample, which is in the region of the volume phase transition. The turbidimeter developed by us, unlike industrial devices of this type, is equipped with a thermostat that allows to study the dependence of the solution turbidity on the temperature. The device operates automatically, the values of luminosity and temperature from digital sensors are processed by the microcontroller and transmitted via the RS-232 protocol to USB ports of a personal computer. The error of luminosity measurement does not exceed 0.1 lux, the temperature measurement accuracy is ± 0.1 °C. This article demonstrates an example of using the designed turbidimeter to study the first-order phase transition in an aqueous solution of hydroxypropylcellulose (2 wt. %) in the presence (absence) of NaCl ions. It is assumed that the sol-gel transition in the investigated solution is due to swelling of polymer coils and their subsequent aggregation. In our opinion, the displacement of the phase transition temperature is due to additional swelling of polymer coils owing to shielding of the electrostatic interaction of monomers in the presence of NaCl ions. It is shown that the intensity of backscattered light corresponds to the kinetics of the formation of the gel network, which makes it possible to establish the dimensions of formed aggregates in the network nodes

Challenges and opportunities for nanotechnology development in Ukraine and the world

The aim of the article. The article deals with the multidisciplinarity and problems of nanotechnology in Ukraine and the world, as well as applications of nanotechnology in various domains of sciences and engineering. The results of the analysis. Special emphasis was placed on the peculiarities of transfer of nanotechnology. Given the breadth of potential applications, nanotechnology already has become a research priority for many countries which results in increased financial support for this area. In Ukraine in the last years universities and institute of NAS of Ukraine make basic scientific programs of nanoscale phenomena and in 2009 owing to initiative of scientists of the National Academy of Sciences of Ukraine the state goal oriented scientific and technical program «Nanotechnology and nanomaterials» for 2010-2014 was launched. The program led to a lot of successful developments and unique technologies, especially in the field of nanocomposites. However, in comparison with countries with average level of development volumes of nanotechnology research and development, its introduction into production is rather low. Due to this fact the National Academy of Sciences of Ukraine created and adopted Resolution of the Presidium of NAS of Ukraine from 07.02.2015 of the «Concept of the target-oriented complex program of fundamental research of NAS of Ukraine «Fundamental issues of new nanomaterials creation» for 2015-2019». Analysis of the activities of the research institutions engaged in nanotechnological R&D shows that the greatest potential in Ukraine is possessed by nanophysics, nanobiotechnologies, nanochemistry and development of various nanomaterials. This program gives opportunities to continue research started in 2010 and create new nanotechnologies and its integration into world research and resolution with its help of significant economic, social and environmental problems in Ukraine. While in the field of transfer of nanotechnology significant steps have been made, but even now there are many problems that still hamper the successful development of this sector. Conclusions and directions of further researches. Thus, nanotechnology can be definitely regarded as one of the most promising areas of technological development for decades to come. One of the main benefits of nanotechnology is its multidisciplinarity that provides products of nanotechnology with wide scope for their application. As a result, almost all countries around the world begin to increase investments in this area, more and more partnerships between research institutions and commercial companies are concluded. The development of this industry also owes much to the field of nanotechnology transfer activities which actively aims to address the difficulties that arise in the commercialization of scientific developments and accelerate the pace of the transfer of nanotechnology. But at the moment in this area there are still many outstanding issues and between the academic and commercial spheres there are contradictions in the vision of the process of transfer of nanotechnology and its main priorities and its pace is still quite slow

Scope and limitations of MALDI-TOF MS blood serum peptide profiling in cancer diagnostics

Serum samples (33 healthy women, 34 ovarian cancer, 28 colorectal cancer, 34 syphilis patients and 136 patients with various benign gynecological diseases) were analyzed by MALDI-TOF MS peptide profiling and respective predictive models were generated by genetic and supervised neural network algorithms. Classification models for pathology versus healthy control showed up to 100% sensitivity and specificity for all target diseases. However, the specificity dropped to unsatisfactory 25–40% in case of target versus nontarget disease diagnostics. Expansion of the control group to an artificial “nominal control” group by adding profiles of benign gynecological diseases considerably improved specificity of the models distinguishing ovarian cancer from healthy control and benign gynecological diseases. The suggested version of MALDI-TOF MS profiling of sera could be applied to differentiate between cancers and benign neoplasms of the same localization which is a challenging task for classical methods. To increase the specificity of diagnostic methods based on peptidome analysis of blood samples, it is necessary to identify sets of concrete peptide structures which qualitatively or quantitatively differ among patients with different diseases. © 2016, Pleiades Publishing, Ltd

Scope and limitations of MALDI-TOF MS blood serum peptide profiling in cancer diagnostics

Serum samples (33 healthy women, 34 ovarian cancer, 28 colorectal cancer, 34 syphilis patients and 136 patients with various benign gynecological diseases) were analyzed by MALDI-TOF MS peptide profiling and respective predictive models were generated by genetic and supervised neural network algorithms. Classification models for pathology versus healthy control showed up to 100% sensitivity and specificity for all target diseases. However, the specificity dropped to unsatisfactory 25–40% in case of target versus nontarget disease diagnostics. Expansion of the control group to an artificial “nominal control” group by adding profiles of benign gynecological diseases considerably improved specificity of the models distinguishing ovarian cancer from healthy control and benign gynecological diseases. The suggested version of MALDI-TOF MS profiling of sera could be applied to differentiate between cancers and benign neoplasms of the same localization which is a challenging task for classical methods. To increase the specificity of diagnostic methods based on peptidome analysis of blood samples, it is necessary to identify sets of concrete peptide structures which qualitatively or quantitatively differ among patients with different diseases. © 2016, Pleiades Publishing, Ltd