Microstructural study of Styrene Polyacrylic (SPA) latex modified mortars

In this paper, the influence of the styrene polyacrylic (SPA) latex polymer on the microstructural properties of limestone mortars has been studied. For this purpose, five mortars were developed with different dosages of the SPA latex (0%, 2.5%, 5%, 7.5% and 10%) by weight of cement. This research was carried out using XRD, FTIR, and SEM analyses. The results of XRD and FTIR studies showed that the addition of SPA latex can increase the portlandite content of polymer-modified mortars (PMMs), compared to the control mortar. In addition, the moist environment promotes the Ca(OH)2 consumption in PMMs at early age and accelerates the hydration. Moreover, the SEM analysis revealed that the cement hydrate structure of the reference mortar is loose. In contrast, the hydrates of the PMMs were covered by a polymer film or membrane, and the pore structure is significantly affected by the filling effect the micropores by the latex particles

Microstructural study of Styrene Polyacrylic (SPA) latex modified mortars

In this paper, the influence of the styrene polyacrylic (SPA) latex polymer on the microstructural properties of limestone mortars has been studied. For this purpose, five mortars were developed with different dosages of the SPA latex (0%, 2.5%, 5%, 7.5% and 10%) by weight of cement. This research was carried out using XRD, FTIR, and SEM analyses. The results of XRD and FTIR studies showed that the addition of SPA latex can increase the portlandite content of polymer-modified mortars (PMMs), compared to the control mortar. In addition, the moist environment promotes the Ca(OH)2 consumption in PMMs at early age and accelerates the hydration. Moreover, the SEM analysis revealed that the cement hydrate structure of the reference mortar is loose. In contrast, the hydrates of the PMMs were covered by a polymer film or membrane, and the pore structure is significantly affected by the filling effect the micropores by the latex particles

Health problems among people with chronic diseases in Algeria in light of the Covid-19 pandemic

نسعى من خلال هذه المقالة الى التعرف عن الأسباب والمشكلات الصحية التي تعاني منها فئة المصابين بالأمراض المزمنة في الجزائر. كون هذه الفئة المصابة بالمرض المزمن داخل المجتمع الجزائري تستلزم توفير الرعاية الصحية والاهتمام بالجوانب الصحية، وخاصة أثناء فترة انتشار وباء كوفيد19. حيث تعتبر الأمراض المزمنة بمثابة المشاكل الصحية الكامنة بجسم الإنسان، ويظل يتعايش معها المريض طوال حياته بعد الإصابة بها وفق برامج وحمية صحية، بحيث تبقى هذه الأمراض تساير حياة الفرد مدى حياته، ومع مرور الزمن تتطور في غالب الاحيان، ومع انتشار وباء كورونا كوفيد19. أصبح هذا النوع من المرضى يلقى صعاب صحية لعدوى الفيروس وفقا لما ذكرته منظمة الصحة العالمية. حيث يستمر هذا المرض غالبا لمدة ثلاثة أشهر أو أكثر. كما أنها لا تنتقل من شخص لآخر، ومنه لا يمكن الوقاية من الأمراض المزمنة بشكل عام عن طريق اللقاحات أو معالجتها بالأدوية، كما أنها لا تختفي ولكن يمكن التعايش مع هذه الأمراض وإدارة أعراضها.  وبالتالي نهدف من خلال هذه المقالة الى الكشف عن المشكلات الصحية التي تعاني منها هذه الفئة من المجتمع الجزائري في ظل انعدام الوسائل والمكانات وهذا نظرا لتفشي واستفحال جائحة كورونا عبر العالم. كما نسعى إلى إبراز الاستراتيجيات المتبعة من طرف وزارة الصحة الجزائرية للحد من هذه المشكلات الصحية لدى فئة المصابين بالأمراض المزمنة وهذا من خلال توفير الاهتمام والرعاية الصحية على جميع المستويات معتمدين في ذلك على المنهج التحليلي الوصفي. موضحين مفهوم الامراض المزمنة، ومبرزين المعاناة والمشكلات الصحية لدى فئة المصابين بالأمراض المزمنة أثناء جائحة كورونا كوفيد19. دون نسيان الإجراءات والاستراتيجيات المتخذة من طرف الحكومة الجزائرية لدى المصابين بالأمراض المزمنة في ظل هذه الجائحةWe seek through this article to identify the causes and health problems that suffer from chronic diseases in Algeria. The fact that this chronically ill group within Algerian society requires the provision of health care and attention to health aspects, especially during the period of the spread of the Covid-19 epidemic. Where chronic diseases are considered as health problems inherent in the human body, and the patient continues to coexist with them throughout his life after infection with them according to healthy programs and diets, so that these diseases remain in line with the individual’s life throughout his life, and with the passage of time they often develop, and with the spread of the Corona Covid-19 epidemic. This type of patient has become very difficult to get infected with the virus, according to the World Health Organization. Where this disease often lasts for three months or more. It is also not transmitted from one person to another, and therefore chronic diseases cannot be prevented in general through vaccines or treated with medicines, nor do they disappear, but these diseases can be coexisted with and their symptoms managed. Thus, we aim, through this article, to reveal the health problems that this group of Algerian society suffers from, in light of the lack of means and capabilities, and this is due to the spread and exacerbation of the Corona pandemic around the world. We also seek to highlight the strategies adopted by the Algerian Ministry of Health to reduce these health problems among people with chronic diseases, by providing attention and health care at all levels, relying on the descriptive analytical approach. Explaining the concept of chronic diseases, and highlighting the suffering and health problems of people with chronic diseases during the Corona Covid-19 pandemic. Without forgetting the measures and strategies taken by the Algerian government for people with chronic diseases in light of this pandemic

Mix proportioning and performance of a crushed limestone sand-concrete

Satisfying the ever-growing demand of concrete aggregates poses a problem in many parts of the world due to shortage of natural sand. Moreover, to conserve natural resources and protect civil engineering infrastructures, there is a need to find alternative materials. Crushed stone sand has been identified as a potential substitute material for natural sand in making good quality concrete. The main objective of the present investigation is to determine an adequate mix design method and evaluate engineering properties of crushed limestone sand concrete mixtures in both the fresh and hardened sates. More than thirty concrete mixtures were examined. The results indicate that water demand and cement paste content in crushed sand concrete are generally higher than that used in similar conventional concrete. Good mechanical properties were obtained for concrete using crushed limestone sand as fine aggregates with a superplasticizer. However, a higher than normally used dosage of superplasticizer is required in these concrete mixtures and the optimum dosage of the superplasticizer needs to be determined for each cement and sand content

Label-free macroscopic fluorescence lifetime imaging of brain tumors

Advanced stage glioma is the most aggressive form of malignant brain tumors with a short survival time. Real-time pathology assisted, or image guided surgical procedures that eliminate tumors promise to improve the clinical outcome and prolong the lives of patients. Our work is focused on the development of a rapid and sensitive assay for intraoperative diagnostics of glioma and identification of optical markers essential for differentiation between tumors and healthy brain tissues. We utilized fluorescence lifetime imaging (FLIM) of endogenous fluorophores related to metabolism of the glioma from freshly excised brains tissues. Macroscopic time-resolved fluorescence images of three intracranial animal glioma models and surgical samples of patients\u27 glioblastoma together with the white matter have been collected. Several established and new algorithms were applied to identify the imaging markers of the tumors. We found that fluorescence lifetime parameters characteristic of the glioma provided background for differentiation between the tumors and intact brain tissues. All three rat tumor models demonstrated substantial differences between the malignant and normal tissue. Similarly, tumors from patients demonstrated statistically significant differences from the peritumoral white matter without infiltration. While the data and the analysis presented in this paper are preliminary and further investigation with a larger number of samples is required, the proposed approach based on the macroscopic FLIM has a high potential for diagnostics of glioma and evaluation of the surgical margins of gliomas

Метаболизм и микроструктура стенки тонкой кишки у пациентов с колоректальным раком

RELEVANCE In patients with colorectal cancer (CRC), the normal small intestine, located outside the pathological focus, undergoes changes that may be the cause of digestive dysfunction after radical surgery to remove the tumor.The assessment of metabolic and microstructural changes in the ileum mucosa in patients with colorectal cancer is necessary to correct the algorithms of postoperative therapy and enteral nutrition. Modern means of optical bioimaging are potentially capable of solving this complex diagnostic problem.AIM OF STUDY To study the features of metabolism and morphological structure of the wall of a conditionally normal small intestine in the mucosa in patients with stage 1–3 CRC using macro- FLIM and optical coherence tomography (OCT).MATERIAL AND METHODS The object of the study was the wall of the ileum (66 samples) from the mucosal side of patients with histologically confirmed CRC stages 1–3 with tumor location in the right sections of the colon. Eight samples were obtained from patients with stage 1 CRC, 38 samples were obtained from patients with stage 2 and 20 samples were obtained from patients with stage 3 tumor. The volume of surgical intervention is right-sided hemicolectomy with total mesocolonectomy, CME (D2 lymph node dissection). Fresh tissue samples were examined using fluorescent lifetime macroimaging (macro-FLIM ) and OCT, followed by histological analysis of the material.RESULTS According to a histological study in the small intestine of patients with stage 1 CRC, the mucosa is covered with a normal single-layer prismatic border epithelium. In the intestine samples of patients with stage 2 CRC, mucus hypersecretion with areas of fibrosis and vascular congestion was observed. At the 3rd stage of CRC, the mucous membrane of the small intestine was loose, with local thickenings, areas of fibrosis with severe leukostasis, and foci of atrophy. None of the samples showed histological signs of a malignant tumor.According to OCT data, in the mucous membrane of the small intestine in patients with the 1st and 2nd stages of CRC, the contours of the villi and, partially, the crypts were well visualized. The structure of the villi was smooth, not coarse, and the shape was regular. In patients with stage 3 CRC, the contours of the crypts and villi were indistinct. There were no differences in the OCT picture between histologic preparations in the 1st and 2nd stages of CRC: the structure of the villi of the small intestine was clear, the shape was unchanged. According to FLIM data, statistically significant differences were revealed in the mean fluorescence lifetime values of reduced nicotinamide dinucleotide (phosphate) NAD(P)H (τm) between 2nd and 3rd (p=0.031), 1st and 3rd (p=0.018) by CRC stages. At the 1st stage of CRC τm was 1.61 [1.30; 2.02] ns, at the 2nd stage 1.50 [1.36; 1.73] ns, at the 3rd stage 1.37 [1.22; 1.51] ns. The FLIM results suggest an increase in the role of glycolysis in enterocyte energy metabolism along with progression of the CRC stage.CONCLUSION In patients with cancer of the right colon, lesions of the microstructure of the mucous membrane were revealed in the ileum not affected by the malignancy. At the same time, the severity of microstructural disorders in the wall of the small intestine is associated with the stage of tumor development in the colon. Bioimaging technologies, namely, methods of optical coherence tomography and fluorescence lifetime macroimaging, made it possible to objectively display microstructural and metabolic disorders in the ileum wall. The data of optical colorectal tomography demonstrated differences in the structural picture of the intestinal villi in patients with stages 1–2 and 3 of colorectal cancer. Results of fluorescence lifetime macroimaging of the metabolic cofactor nicotinamide dinucleotide (phosphate) confirmed an increase in the role of glycolysis in the energy metabolism of enterocytes along with an increase in the stage of colorectal cancer. The identified disorders in the state of the small intestine develop in patients with colorectal cancer before surgery and are highly likely to be an important pathogenetic link of malabsorption in the postoperative period. If the hypothesis is confirmed, the developed algorithm for the complex diagnosis of microstructural and metabolic disorders in tissues will expand the possibilities for the rehabilitation of patients with cancer of the right colon.АКТУАЛЬНОСТЬ У пациентов с колоректальным раком (КРР) нормальная тонкая кишка, расположенная вне патологического очага, претерпевает изменения, которые могут быть причиной пищеварительной дисфункции после радикальной операции по удалению опухоли.Оценка метаболических и микроструктурных изменений в слизистой оболочке подвздошной кишки у пациентов с КРР необходима для коррекции алгоритмов послеоперационной терапии, энтерального питания. Современные средства оптического биоимиджинга потенциально способны решить эту сложную диагностическую задачу.ЦЕЛЬ Исследовать особенности метаболизма и морфологической структуры стенки условно нормальной тонкой кишки со стороны слизистой оболочки у пациентов с КРР 1–3-й стадий методами макро-FLIM и оптической когерентной томографии (ОКТ).МАТЕРИАЛ И МЕТОДЫ Объектом исследования являлась стенка подвздошной кишки (66 образцов) со стороны слизистой оболочки у пациентов с гистологически подтвержденным КРР 1–3-й стадий с локализацией опухоли в правых отделах ободочной кишки. 8 образцов получены у пациентов с 1-й стадией КРР, 38 образцов — у пациентов со 2-й стадией и 20 образцов — с 3-й стадией развития опухоли. Объем оперативного вмешательства — правосторонняя гемиколэктомия с тотальной мезо­колонэктомией — CME (лимфодиссекцией Д2). Свежие образцы ткани исследовали методами флуоресцентного время-разрешенного макроимиджинга (макро-FLIM) и ОКТ с последующим гистологическим анализом материала.РЕЗУЛЬТАТЫ По данным гистологического исследования в тонкой кишке пациентов с 1-й стадией КРР слизистая оболочка покрыта нормальным однослойным призматическим каемчатым эпителием. В образцах кишки пациентов со 2-й стадией КРР наблюдалась гиперсекреция слизи с участками фиброза и полнокровием сосудов. При 3-й стадии КРР слизистая оболочка тонкой кишки была рыхлой, с локальными утолщениями, участками фиброза с выраженным лейкостазом и очагами атрофии. Ни в одном из образцов не обнаружены гистологические признаки злокачественной опухоли.По данным ОКТ в слизистой оболочке тонкой кишки у пациентов с 1-й и 2-й стадиями КРР хорошо визуализировались контуры ворсинок и, частично, крипты. Структура ворсинок была гладкой, негрубой, а форма регулярной. У пациентов с 3-й стадией КРР контуры крипт и ворсинок были нечеткими. Различий в картине ОКТ между гистологическими препаратами при 1-й и 2-й стадиях КРР получено не было: структура ворсинок тонкой кишки была четкой, форма неизмененной. По данным FLIM выявлены статистически значимые отличия в показателях среднего времени жизни флуоресценции восстановленного никотинамиддинуклеотида (фосфата) НАД(Ф)Н (τm) между 2-й и 3-й (p=0,031), 1-й и 3-й (p=0,018) стадиями КРР. При 1-й стадии КРР τm составило 1,61 [1,30; 2,02] нс, при 2-й стадии — 1,50 [1,36; 1,73] нс, при 3-й стадии — 1,37 [1,22; 1,51] нс. Результаты FLIM предположительно свидетельствуют об увеличении роли гликолиза в энергетическом метаболизме энтероцитов вместе с увеличением стадии КРР.ЗАКЛЮЧЕНИЕ У пациентов с раком правых отделов ободочной кишки в не затронутой злокачественным поражением подвздошной кишке зафиксированы нарушения микроструктуры слизистой оболочки. При этом выраженность нарушений микроструктуры в стенке тонкой кишки связана со стадией развития опухоли в толстой кишке. Технологии биовизуализации, а именно — методы оптической когерентной томографии и флуоресцентного время-разрешенного макроимиджинга, позволили объективно отобразить нарушения микроструктуры и метаболизма в стенке подвздошной кишки. Данные оптической колоректальной томографии продемонстрировали различия в структурной картине ворсинок кишки у пациентов 1–2-й и 3-й стадий колоректального рака. Результаты флуоресцентного время-разрешенного макроимиджинга метаболического кофактора никотинамиддинуклеотида (фосфата) свидетельствовали об увеличении роли гликолиза в энергетическом метаболизме энтероцитов вместе с ростом стадии колоректального рака. Выявленные нарушения в состоянии тонкой кишки развиваются у пациентов с колоректальным раком до операции и с высокой вероятностью являются важным патогенетическим звеном мальабсорбции в послеоперационном периоде. В случае подтверждения гипотезы, разработанный алгоритм комплексной диагностики нарушений микроструктуры и метаболизма в тканях расширит возможности реабилитации пациентов с раком правых отделов толстой кишки