Band splitting and relative spin alignment in bilayer systems

Influence of relative spin alignment on the band splitting and magnetic excitations in the bilayer correlated systems is studied. Splitting occures to be large or small depending on orientation of staggered spins of layers. Change of the ground state configuration with doping is shown. Behavior of the bilayer splitting in Bi-based cuprate allows to suppose that superconducting transition is accompanied by transformation of spin configuration of system.Comment: 9 pages, 3 figure

The Fermi surface reconstruction in stripe phases of cuprates

Mean-field study of the stripe structures is conducted for a hole-doped Hubbard model. For bond-directed stripes, the Fermi surface consists of segments of an open surface and the boundaries of the hole pockets which appear in the diagonal region of momenta under certain conditions. Segments of the first type are due to one-dimensional bands of states localized on the domain walls. The relation of bands to the doping and temperature dependences of the Hall constant is discussed. In connection with the observation of quantum magnetic oscillations, a systematic search for the electron pockets has been carried out. It is shown that the formation of such pockets in bilayer models is quite possible.Comment: 4 pages, 3 figure

Influence of spin structures and nesting on Fermi surface and a pseudogap anisotropy in t-t'-U Hubbard model

Influence of two type of spin structures on the form of the Fermi surface (FS) and a photoemission intensity map is studied for t-t'-U Hubbard model. Mean field calculations are done for the stripe phase and for the spiral spin structure. It is shown, that unlike a case of electron doping, the hole-doped models are unstable with respect to formation of such structures. The pseudogap anisotropies are different for h- and e- doping. In accordance with ARPES data for La2SrxCuO4 the stripe phase is characterized by quasi-one-dimensional segments of FS at k=(\pi,0) and by suppression of spectral weight in diagonal direction. It is shown that spiral structures display the polarisation anisotropy: different segments of FS correspond to electros with different spin polarisations.Comment: 12 pages, 4 figure

Time reversal symmetry breaking in cuprates induced by the spiral spin order

We propose a new interpretation of the spontaneous time reversal symmetry breaking (TRSB) observed recently in a pseudogap state of cuprate (Kaminsky et al.). It is shown that the TRSB dichroism in ARPES signal may be connected with the local spiral spin structures in system. It may be caused by a spin-orbit interaction and by spin polarization of electrons at various sections of Fermi surface in spiral state. Angular dependence of dichroism signal is studied in schematic KKR approximation. Tests are proposed to check an existence of the local spiral spin structure and to distiguish it from the TRSB state with micro-currents constructed by Varma.Comment: 7 pages, Revtex, 4 figure

Formation of ultracold RbCs molecules by photoassociation

The formation of ultracold metastable RbCs molecules is observed in a double species magneto-optical trap through photoassociation below the ^85Rb(5S_1/2)+^133Cs(6P_3/2) dissociation limit followed by spontaneous emission. The molecules are detected by resonance enhanced two-photon ionization. Using accurate quantum chemistry calculations of the potential energy curves and transition dipole moment, we interpret the observed photoassociation process as occurring at short internuclear distance, in contrast with most previous cold atom photoassociation studies. The vibrational levels excited by photoassociation belong to the 5th 0^+ or the 4th 0^- electronic states correlated to the Rb(5P_1/2,3/2)+Cs(6S_1/2) dissociation limit. The computed vibrational distribution of the produced molecules shows that they are stabilized in deeply bound vibrational states of the lowest triplet state. We also predict that a noticeable fraction of molecules is produced in the lowest level of the electronic ground state

Эффективность и безопасность кабозантиниба у пациентов с распространенным почечно-клеточным раком: российское многоцентровое наблюдательное исследование

Purpose: an assessment of efficacy and safety of cabozantinib in unselected patients with metastatic renal cell carcinoma in the first and subsequent lines of therapy.Materials and methods. Russian multicenter observational study included 92 consecutive patients with morphologically verified metastatic renal cell carcinoma treated with cabozantinib (60 mg/d) in 16 Russian centers. Median age of the patients was 56 (19-79) years, a male-to-female ratio - 3:1. At the start of cabozantinib therapy 27.2 % of patients had ECOG PS 2. Most common histological type of kidney cancer was clear-cell RCC (90.2 %). Most patients were diagnosed with synchronous (71.7 %) multiple metastases (60.9 %). Previous nephrectomy was performed in 87.0 % of cases. Prognosis according to International Metastatic Renal Cancer Database Consortium (IMDC) score was assessed as favorable in 5.4 %, intermediate - in 58.7 % and poor - in 35.9 % patients. Cabozantinib as the first-line therapy was administered in 9 (9.8 %), following 1-5 lines of systemic treatment - in 83 (90.2 %) cases. Median follow-up was 11 (2.3-44.5) months.Results. In patients, receiving cabozantinib as the first-line therapy, objective response rate was 66.7 %, tumor control was reached in 100 % of cases. Median time to the objective response was 2.6 (1.9-3.6) months, median objective response duration - 13.2 (6.2-21.5) months. Median progression-free survival (PFS) and overall survival (OS) were not reached, 6- and 12-months PFS was 77.8 % and 77.8 %, 6- and 12-months OS - 88.9 % and 88.9 % respectively. Cabozantinib as the second and subsequent lines of therapy provided objective response rate of 34.9 %, tumor control rate - 97.6     %. Median time to the objective response was 2.5 (1.8-4.1) months, median objective response duration - 12.6 (5.5-27.3) months. Median PFS was not reached (6- and 12-months PFS - 92.5 % and 73.1 % respectively), median OS was 32.6      months (6- and 12-months OS - 97.4 % and 80.8 % respectively). Any adverse events (AE) developed in 88.8 %, AE grade III-IV - in 32.6 % of cases. Most frequent AE grade III-IV included arterial hypertension (18.5 %), diarrhea (6.5 %) and palmar-plantar erythrodysesthesia (6.5 %). Unacceptable toxicity demanded treatment cancellation in 2.2 %, therapy interruption - in 16.3 % and dose reduction - in 30.4 % of patients.Conclusion. Cabozantinib as the first and subsequent lines of therapy for metastatic renal cell carcinoma patients in the real world practice demonstrated high efficacy and better tolerability comparing with population assigned for cabozantinib monotherapy in the randomized phase II-III trials.Цель исследования - оценка эффективности и безопасности кабозантиниба у неотобранных пациентов с метастатическим почечно-клеточным раком в 1-й и последующих линиях терапии.Материалы и методы. В многоцентровое обсервационное исследование было последовательно включено 92 пациента с морфологически верифицированным метастатическим почечно-клеточным раком, получавшие кабозантиниб (60 мг/сут) в 16 российских центрах. Медиана возраста больных составила 56 (19-79) лет, соотношение мужчин и женщин - 3:1. На момент старта терапии кабозантинибом ECOG PS 2 имел место у 27,2 % пациентов. Наиболее частым гистологическим вариантом рака почки являлся светлоклеточный (90,2 %). У большинства больных диагностированы синхронные (71,7 %) множественные метастазы (60,9 %). Предшествующая нефрэктомия выполнена в 87,0 % случаев. Прогноз по шкале International Metastatic Renal Cancer Database Consortium (IMDC) был расценен как благоприятный у 5,4 %, промежуточный - у 58,7 % и неблагоприятный - у 35,9 % больных. Кабозантиниб в качестве терапии 1-й линии применялся в 9 (9,8 %), после 1-5 линий системной терапии - в 83 (90,2 %) случаях. Медиана наблюдения за всеми пациентами составила 11 (2,3-44,5) мес.Результаты. У больных, получавших кабозантиниб в качестве терапии 1-й линии, частота объективного ответа составила 66,7 %, контроль над опухолью достигнут в 100 % случаев. Медиана времени до объективного ответа равнялась 2,6 (1,9-3,6) мес, медиана продолжительности объективного ответа - 13,2 (6,2-21,5) мес. Медианы беспрогрессивной выживаемости (БПВ) и общей выживаемости (ОВ) не достигнуты, 6- и 12-месячная БПВ составила 77,8 и 77,8 %, 6- и 12-месячная ОВ - 88,9 и 88,9 % соответственно. Кабозантиниб в качестве 2-й и последующих линий терапии обеспечил частоту объективного ответа 34,9 % и частоту контроля над опухолью, достигшую 97,6 %. Медиана времени до объективного ответа составила 2,5 (1,8-4,1) мес, медиана продолжительности объективного ответа - 12,6 (5,5-27,3) мес. Медиана БПВ не достигнута (6- и 12-месячная БПВ - 92,5 и 73,1 % соответственно), медиана ОВ составила 32,6 мес (6- и 12-месячная ОВ - 97,4 и 80,8 % соответственно). Любые нежелательные явления развились в 88,8 %, нежелательные явления III-IV степени - в 32,6 % случаев. Наиболее частыми нежелательными явлениями III-IV степени были артериальная гипертензия (18,5 %), диарея (6,5 %) и ладонно-подошвенная эритродизестезия (6,5 %). Неприемлемая токсичность потребовала отмены лечения у 2,2 %, прерывания терапии - у 16,3 % и снижения дозы - у 30,4 % больных.Заключение. Кабозантиниб в 1-й и последующих линиях терапии метастатического почечно-клеточного рака в реальной мировой практике продемонстрировал высокую эффективность и лучшую переносимость по сравнению с результатами рандомизированных исследований II-III фаз