Investigation of LiFeAs by means of "Break-junction" Technique

In our tunneling investigation using Andreev superconductor - normal metal - superconductor contacts on LiFeAs single crystals we observed two reproducible independent subharmonic gap structures at dynamic conductance characteristics. From these results, we can derive the energy of the large superconducting gap $\Delta_L=(2.5 \div 3.4)$ meV and the small gap $\Delta_L=(0.9 \div 1)$ meV at $T = 4.2$ K for the $T_C^{local} \approx (10.5 \div 14)$ K (the contact area critical temperature which deviation causes the variation of $\Delta_L$). The BCS-ratio is found to be $2\Delta_L/k_BT_C = (4.6 \div 5.6)$, whereas $2\Delta_S/k_BT_C \ll 3.52$ results from induced superconductivity in the bands with the small gap.Comment: 7 pages, 5 figures. Published in Pis'ma v ZhETF 95, 604-610 (2012

АТРИОСЕПТОСТОМИЯ С ИМПЛАНТАЦИЕЙ ФЕНЕСТРИРОВАННОГО ОККЛЮДЕРА ПРИ ИДИОПАТИЧЕСКОЙ ЛЕГОЧНОЙ ГИПЕРТЕНЗИИ

Introduction. Pulmonary arterial hypertension (PAH) is a rare disease of unknown etiology, characterized by increased resistance of pulmonary vessels, which leads to right ventriculae heart failure and, eventually, death. At the same time, according to the literature, it has been established that the presence of an atrial septum defect in patients with idiopathic PAH (iPAH), is accompanied by a longer life expectancy, improves its quality and is the prevention of sudden death due to the development of a pulmonary hypertensive crisis. We decided to perform an operation to create an atrial septum communication (ASC) in patients with iPAH.Materials and methods. Clinical cases showed efficiency in creating interatrial septum fenestration by implantation of intentionally fenestrated occluder in patients with PAH.Results. It was in studies revealing that the advantage of this method as compared to others is close good fixation of the device on interatrial baffle which reduces possibility for the device to migrate from fixed position in the heart cavity and to reduce intra-operative complication. After implantation of fenestrated occluder the patients showed significant improvement of life quality: decrement of breathlessness, higher tolerance to physical exertion, less swelling in lower limbs, absence of syncopal condition. Such procedure perhaps prolongs life time.Conclusion. Implantation of fenestrated occluder, modified in intra-operative conditions, can be an adequate method to help patients with iPAH, under conditions of unavailability of special devices in the market. Введение. Легочная артериальная гипертензия (ЛАГ) является прогрессирующим смертельным синдромом, характеризующимся повышенным сопротивлением легочных сосудов, что приводит к правосторонней сердечной недостаточности и в итоге — смерти. Вместе с тем было доказано, что наличие открытого овального окна у больных с идиопатической легочной артериальной гипертензией (иЛАГ) сопровождается большей продолжительностью жизни и значительно более высоким ее качеством. Это является обоснованием исследований по созданию межпредсердного сообщения (МПС) у больных с иЛАГ. Цель создания адекватного МПС — профилактика внезапной смерти вследствие развития легочно-гипертензионного криза.Материалы и методы. На клинических случаях продемонстрирована эффективность cоздания межпредсердного сообщения путем имплантации намеренно фенестрированных окклюдеров пациентам с ЛАГ.Результаты. Установлено, что преимуществом данного метода перед другими является плотная хорошая фиксация устройства на межпредсердной перегородке, что уменьшает возможность миграции устройства из фиксированного положения в полости сердца и интраоперационных осложнений. После имплантации фенестрированного окклюдера у пациентов наблюдалось значительное улучшение качества жизни: снижение одышки, повышение толерантности к физической нагрузке, уменьшение отеков нижних конечностей, отсутствие синкопальных состояний. Данная процедура предположительно способствует увеличению продолжительности жизни.Заключение. Имплантация фенестрированного окклюдера, модифицированного в интраоперационных условиях, может быть адекватным методом помощи пациентам с иЛАГ в условиях недоступности специальных устройств на рынке.

Synthesis of γ-, δ-, and ε-Lactams by Asymmetric Transfer Hydrogenation of N-(tert-Butylsulfinyl)iminoesters

Highly enantiomerically enriched γ- and δ-lactams have been prepared by a simple and very efficient procedure that involves the asymmetric transfer hydrogenation of N-(tert-butylsulfinyl)iminoesters followed by desulfinylation of the nitrogen atom and spontaneous cyclization to the desired lactams during the basic workup procedure. Five- and six-membered ring lactams bearing aromatic, heteroaromatic, and aliphatic substituents have been obtained in very high yields and ee’s up to >99%. A slight modification of the procedure also allowed the preparation of ε-lactams in good yields and very high enantioselectivities. Both enantiomers of the final lactams could be prepared with equal efficiency by changing the absolute configuration of the sulfinyl chiral auxiliary

ATRIAL SEPTUM FENESTRATION FOR PATIENT WITH IDIOPATHIC PULMONARY ARTERY HYPERTENSION

Introduction. Pulmonary arterial hypertension (PAH) is a rare disease of unknown etiology, characterized by increased resistance of pulmonary vessels, which leads to right ventriculae heart failure and, eventually, death. At the same time, according to the literature, it has been established that the presence of an atrial septum defect in patients with idiopathic PAH (iPAH), is accompanied by a longer life expectancy, improves its quality and is the prevention of sudden death due to the development of a pulmonary hypertensive crisis. We decided to perform an operation to create an atrial septum communication (ASC) in patients with iPAH.Materials and methods. Clinical cases showed efficiency in creating interatrial septum fenestration by implantation of intentionally fenestrated occluder in patients with PAH.Results. It was in studies revealing that the advantage of this method as compared to others is close good fixation of the device on interatrial baffle which reduces possibility for the device to migrate from fixed position in the heart cavity and to reduce intra-operative complication. After implantation of fenestrated occluder the patients showed significant improvement of life quality: decrement of breathlessness, higher tolerance to physical exertion, less swelling in lower limbs, absence of syncopal condition. Such procedure perhaps prolongs life time.Conclusion. Implantation of fenestrated occluder, modified in intra-operative conditions, can be an adequate method to help patients with iPAH, under conditions of unavailability of special devices in the market