Adsorption of Tributyl Phosphate on Silica Gel

The adsorption behaviour of tributyl phosphate (TBP) on silica gel was studied. It was found that the adsorption isotherm shapes were complicated, being considered as S- and L-type isotherms according to the Giles classification. Adsorption itself was polymolecular and of a physical nature, the first adsorptive layer involving hydrogen bonding between the protons of surface silanol groups and the electron-donating oxygen atom of the adsorbate molecule. Subsequent adsorption layers were formed via van der Waals interaction. The free energy of adsorption of the system lay between −22.1 kJ/mol and −23.8 kJ/mol. The enthalpy change was negative and very small, i.e. −6.3 kJ/mol, while the entropy change was positive and in the range 53.9 J/(mol K) to 55.4 J/(mol K). The increase in entropy was explained in terms of the mobility of the TBP molecules in the adsorptive layer arising from their replacement on the silica gel surface by water molecules derived from the aqueous medium

ADSORPTION OF LANTHANUM IONS BY FINELY DISPERSED WAXES

The kinetics of the adsorption of lanthanum ions superfine particles of peat and lignite waxes. It has been shown that the rate of adsorption on a peat wax (3,5 ÷ 1,9 mmol/(g∙min)) is higher than lignite (1,8 ÷ 1,3 mmol/(g∙min)). Found that the adsorption isotherms are complex S- shaped form. And the capacitance values of the monolayer adsorption equilibrium constant in the case of peat ( 255 mmol/g and 1224,5 l/mol, respectively), the wax is higher than in the case of brown coal (85,5 mmol/g and 296,0 l/mol, respectively). The main characteristics of the colloid-chemical suspensions waxes: the most probable radius of the particles (4-5 microns ), their zeta potential ( -50 mV in the case of peat wax – 5mV and – in the case of lignite wax) and the pH of the isoelectric state of the wax particles ( 5,5-5,7 )

О возможности повышения информативности диагностики необратимой легочной гипертензии у кандидатов на трансплантацию сердца

Background: Fixed pulmonary hypertension (PH) in heart transplant candidates is a risk factor for right ventricular failure in the postoperative period and early mortality. Patients with fixed PH are not included in the waiting list. Thus, the correct assessment of the pulmonary circulation before the operation affects both clinical management and prognosis. Aim: To reduce the risk of incorrect patient non-inclusion to the waiting list by reduction of false negative test results for PH reversibility.Materials and methods: Fourteen heart transplant candidates were included in this retrospective cohort single center study. Fixed PH with pulmonary vascular resistance (PVR) exceeding 3.5 Wood's units was found in all these patients using right heart catheterization and pulmonary vasoreactivity tests. Initially, these patients had not been put into the waiting list. Pulmonary catheterization was performed in the intensive care unit with a Swan-Ganz catheter and pre-pulmonary thermodilution technique. To perform pulmonary vasoreactivity tests, inhaled iloprost (n = 12) or nitric oxide (n = 2) were used. Subsequently all patients received levosimendan infusion at a dose of 12.5 (0.05–0.2) mg/kg/min, with repeated pulmonary artery catheterization and pulmonary vasoreactivity tests at 72 hours after the infusion. Pulmonary vasoreactivity tests results allowed 13 patients to be included into the waiting list. Heart transplantation was performed in 8 recipients, with postoperative assessment of their hemodynamic and clinical parameters. Data are presented as median [25th percentile; 75th percentile].Results: After the levosimendan infusion, there was a decrease in the pulmonary artery mean pressure from 45 [36; 47] to 29.5 [23; 37] mm Hg (p 0.01), and in PVR from 6.9 [4.9; 8.9] to 3.6 [2.9; 5.9] Wood's units (p 0.01). In 7 patients, PVR decreased to less than 3.5 Wood's units: the rest of the patients underwent pulmonary vasoreactivity tests. As a result, 13 of 14 patients showed reversible PH and were included into the waiting list. By the date of the manuscript submission, heart transplantation has been performed in 8 patients. Their PVR 6 hours after surgery was 2.2 [2; 3.1] Wood's units; there were no cases of fixed PH and right heart failure. There was a single death associated to a hemorrhagic stroke at day 6 after heart transplantation. The sensitivity of pre-operative pulmonary vasoreactivity tests with the use of levosimendan was 87.5%.Conclusion: Levosimendan infusion may increase the sensitivity of the pulmonary vasoreactivity tests before patients' inclusion into the waiting list for heart transplantation.Актуальность. Необратимая легочная гипертензия (ЛГ) у кандидатов на трансплантацию сердца – фактор риска развития правожелудочковой недостаточности в послеоперационном периоде и ранней летальности. Пациентов с необратимой ЛГ не включают в лист ожидания трансплантации сердца. Таким образом, корректность оценки состояния малого круга кровообращения до операции влияет не только на тактику лечения, но и на прогноз.Цель – снизить риск ошибочного невключения пациентов в лист ожидания трансплантации сердца путем сокращения числа ложноотрицательных результатов тестов на обратимость ЛГ.Материал и методы. В ретроспективное когортное описательное одноцентровое исследование включили 14 кандидатов на трансплантацию сердца, у которых при катетеризации легочной артерии (ЛА) и выполнении теста на обратимость ЛГ была обнаружена необратимая ЛГ с легочным сосудистым сопротивлением (ЛСС), превышающим 3,5 ед. Вуда. Первоначально этим пациентам было отказано во включении в лист ожидания трансплантации сердца. Катетеризацию ЛА выполняли в условиях отделения реанимации и интенсивной терапии с применением катетера Swan-Ganz и метода препульмональной термодилюции. Для выполнения теста на обратимость ЛГ применяли ингаляцию илопроста (у 12 человек) или оксида азота (у 2). В дальнейшем всем больным была назначена инфузия левосимендана в дозе 12,5 мг со скоростью 0,05–0,2 мкг/кг/мин, через 72 часа после которой провели повторную катетеризацию ЛА и тесты на обратимость ЛГ. По их результатам 13 пациентов были включены в лист ожидания. Трансплантация сердца была выполнена 8 реципиентам, в послеоперационном периоде оценивали гемодинамические данные и показатели клинического течения. Данные представлены как медиана [25-й; 75-й процентили].Результаты. После инфузии левосимендана отмечено снижение среднего давления в ЛА с 45 [36; 47] до 29,5 [23; 37] мм рт. ст. (p 0,01), ЛСС уменьшилось с 6,9 [4,9; 8,9] до 3,6 [2,9; 5,9] ед. Вуда (p 0,01). У 7 пациентов ЛСС снизилось до показателя менее 3,5 ед. Вуда, остальным больным был выполнен повторный тест на обратимость ЛГ. В итоге 13 из 14 пациентов продемонстрировали обратимый характер ЛГ и были включены в лист ожидания трансплантации сердца. На момент подготовки публикации трансплантация сердца была выполнена 8 пациентам. ЛСС через 6 ч после трансплантации сердца составило 2,2 [2; 3,1] ед. Вуда, случаев необратимой ЛГ и правожелудочковой недостаточности отмечено не было. Единственный летальный исход был связан с развитием геморрагического инсульта на 6-е сутки после операции. Чувствительность дооперационной диагностики обратимости ЛГ при назначении левосимендана составила 87,5%.Заключение. Инфузия левосимендана может повысить чувствительность теста на обратимость ЛГ перед включением пациентов в лист ожидания трансплантации сердца

Genome-wide association analyses of risk tolerance and risky behaviors in over 1 million individuals identify hundreds of loci and shared genetic influences

Molecular Epidemiolog

A genome-wide cross-phenotype meta-analysis of the association of blood pressure with migraine

Blood pressure (BP) was inconsistently associated with migraine and the mechanisms of BP-lowering medications in migraine prophylaxis are unknown. Leveraging large-scale summary statistics for migraine (Ncases/Ncontrols = 59,674/316,078) and BP (N = 757,601), we find positive genetic correlations of migraine with diastolic BP (DBP, rg = 0.11, P = 3.56 × 10−06) and systolic BP (SBP, rg = 0.06, P = 0.01), but not pulse pressure (PP, rg = −0.01, P = 0.75). Cross-trait meta-analysis reveals 14 shared loci (P ≤ 5 × 10−08), nine of which replicate (P < 0.05) in the UK Biobank. Five shared loci (ITGB5, SMG6, ADRA2B, ANKDD1B, and KIAA0040) are reinforced in gene-level analysis and highlight potential mechanisms involving vascular development, endothelial function and calcium homeostasis. Mendelian randomization reveals stronger instrumental estimates of DBP (OR [95% CI] = 1.20 [1.15–1.25]/10 mmHg; P = 5.57 × 10−25) on migraine than SBP (1.05 [1.03–1.07]/10 mmHg; P = 2.60 × 10−07) and a corresponding opposite effect for PP (0.92 [0.88–0.95]/10 mmHg; P = 3.65 × 10−07). These findings support a critical role of DBP in migraine susceptibility and shared biology underlying BP and migraine