Osteointegration Characterization of Additive Manufactured Porous Titanium Scaffold Based on Microhardness and Ca/P Ratio

Additive technologies are getting widely used in orthopedics due to the opportunity of full modelling of complex cellular structures and producing personalized implants. Titanium and its alloys are still the main material used for metallic implants manufacturing. In this study microhardness and Ca/P ratio of bone tissue surrounding the implant were investigated. By means of ABAQUS software titanium porous structure implants were designed. Their biomechanical properties were close to biomechanical properties of trabecular bone tissue. Direct metal laser sintering (DMLS) was used to manufacture implants from Ti-6Al-4V titanium alloy. They were augmented in trabecular bone defects of Chinchilla rabbits for 6, 12 and 25 weeks. The samples were examined by scanning electron microscopy (SEM) in a FEG SEM ZEISS CrossBeam AURIGA and the Ca/P ratio was calculated using the accompanying Oxford Inca software. Vickers hardness test method was performed for microhardness. It was shown that there was a significant increase in both mineral and mechanical properties of bone samples with an increase of observation period. The results found in this study illustrate a distinct relationship between the mineralization parameter of bone tissue and its microhardness (r = 0.808, r2 = 0.65).     Keywords: Scaffold, Microhardness, Titanium, Ca/P ratio, Bone defect, Osteointegration, Additive manufacturin

Analysis of antibiotic prescriptions in patients with community-acquired pneumonia in clinical practice

Objective. To analyze new strategies for the treatment of community-acquired pneumonia (CAP) by age and assess treatment efficacy by age category based on real world data. Materials and Methods. A total of 612 patients (medical charts) with CAP treated in 3 hospitals during the 2017–2019 were included in the retrospective pharmacoepidemiological study. A retrospective analysis of antimicrobial therapy (AMT) administration in the treatment of CAP was performed. Results. Duration of hospital stay in CAP patients of young age was 10% shorter than in patients of any other age category. The least frequency (19.6%) of antibiotic combination administration as initial empiric therapy was found in patients of young age. There were no significant differences in frequency of initial AMT administration between age groups. Ceftriaxone, cefepime and cefoperazone were the most common antimicrobials used as monotherapy in all age groups. Ceftriaxone with azithromycin combination was the most common (42%) initial combination therapy in all age groups. The highest number (27) of various antibiotic combinations was administered to old patients, and the lowest number (16) – to young patients. Efficacy of initial AMT was similar between elderly and old patients. Overall efficacy of initial AMT in patients with non-severe CAP and severe CAP was 54% and 50%, respectively. Analysis of antimicrobial treatment of CAP in real practice and its compliance with the current clinical guidelines showed cephalosporin plus macrolide to be a predominant antibiotic combination (83%). Conclusions. Antibiotic combination administration was found to be common in patients with non-severe CAP, whereas initial monotherapy was administered to severe CAP patients. Antibiotic prescription pattern in patient of young age was different from that in any other age groups. CAP had a less severe course in young patients as evidenced by shorter duration of hospital stay, more frequent monotherapy administration and higher efficacy of initial AMT compared to other age categories. There were no prescriptions of the recommended fifth generation cephalosporin (ceftaroline fosamil)

Large negative velocity gradients in Burgers turbulence

We consider 1D Burgers equation driven by large-scale white-in-time random force. The tails of the velocity gradients probability distribution function (PDF) are analyzed by saddle-point approximation in the path integral describing the velocity statistics. The structure of the saddle-point (instanton), that is velocity field configuration realizing the maximum of probability, is studied numerically in details. The numerical results allow us to find analytical solution for the long-time part of the instanton. Its careful analysis confirms the result of [Phys. Rev. Lett. 78 (8) 1452 (1997) [chao-dyn/9609005]] based on short-time estimations that the left tail of PDF has the form ln P(u_x) \propto -|u_x|^(3/2).Comment: 10 pages, RevTeX, 10 figure

Plasma rotation diagnostics at the FT-2 tokamak based on the upper hybrid resonance backscattering enhanced doppler effect

Observations of enhanced Doppler frequency shift effect of the highly localized microwave backscattering in the upper hybrid resonance are reported. The experiment is performed at FT-2 tokamak, where a steerable focusing antenna set, allowing off equatorial plane plasma extraordinary wave probing from high magnetic field side, was installed. A separate line less than 1.5 MHz wide and shifted by up to 2 MHz is routinely observed in the backscattering spectrum under condition of accessible upper hybrid resonance. The enhanced frequency shift is explained by the growth of poloidal wave number of the probing wave in the resonance. Development of a new scheme for local diagnostics of fluctuations poloidal rotation based on this effect is started.У статті описуються спостереження посиленого ефекту Доплера в спектрі сигналу розсіяного назад у верхньому гібридному резонансі зондувальної хвилі. Експеримент виконаний на токамаці ФТ-2, на якому недавно були встановлені рухливі антени, що дозволяють здійснювати зондування плазми електромагнітними хвилями в незвичайній поляризації з боку сильного магнітного поля. За умови доступного верхнього гібридного резонансу в спектрі розсіювання спостерігалася лінія шириною менш 1.5 МГц, зрушена до 2 МГц. Ефект пояснений ростом полоідального хвильового числа зондувальної хвилі в резонансі. Почато розвиток нової схеми локальної діагностики обертання плазмових флуктуацій, заснованої на цьому ефекті.В статье описываются наблюдения усиленного эффекта Доплера в спектре сигнала рассеянного назад в верхнем гибридном резонансе зондирующей волны. Эксперимент выполнен на токамаке ФТ-2, на котором недавно были установлены подвижные антенны, позволяющие осуществлять зондирование плазмы электромагнитными волнами в необыкновенной поляризации со стороны сильного магнитного поля. При условии доступного верхнего гибридного резонанса в спектре рассеяния наблюдалась линия шириной менее 1.5 МГц, сдвинутая до 2 МГц. Эффект объяснён ростом полоидального волнового числа зондирующей волны в резонансе. Начато развитие новой схемы локальной диагностики вращения плазменных флуктуаций, основанной на этом эффекте

Clinical and hemodynamic aspects of hepatic and extrahepatic portal hypertension

Background. Significant variability of the quantitative indices of portal blood flow in chronic hepatitis, cirrhosis, chronic heart failure, Budd-Chiari disease confirms the need for further search for clinical and hemodynamic features in various forms of portal hypertension (PH). The purpose was to determine the relationship between dopplerographic indices of the portal system, clinical data and the main markers of cytolytic, cholestatic and mesenchymal-inflammatory syndromes in patients with hepatic and extrahepatic PH. Materials and methods. The study included 205 patients with PH and 35 patients without PH who underwent examination and treatment in the gastroenterology department of the Mykolaiv Regional Clinical Hospital. All patients underwent clinical examination, dopplerography of the portal system vessels, and biochemical blood test. Results. In patients with hepatic PН, the greatest changes in the dopplerographic indices of both venous and arterial blood flow were observed simultaneously with a significant degree of cytolysis and cholestasis markers, and the revealed reliable correlation indicates their associative character. A characteristic feature of extrahepatic hypertension was the absence of signs of liver failure or their lesser severity, and no parallelism was found between biochemical and hemodynamic parameters in this form of PН

RECOMMENDATION ON THE 7–VALENT PNEUMOCOCCAL CONJUGATED VACCINE AMONG CHILDREN

The article provides a guideline and practical recommendations of the Advisory Committee on Immunization Practices for the use of the 7'valent conjugated pneumococcal vaccine.Key words: pneumococcal infection, vaccination, children