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Parametric resonance of magnetization excited by electric field

Manipulation of magnetization by electric field is a central goal of spintronics because it enables energy-efficient operation of spin-based devices. Spin wave devices are promising candidates for low-power information processing but a method for energy-efficient excitation of short-wavelength spin waves has been lacking. Here we show that spin waves in nanoscale magnetic tunnel junctions can be generated via parametric resonance induced by electric field. Parametric excitation of magnetization is a versatile method of short-wavelength spin wave generation, and thus our results pave the way towards energy-efficient nanomagnonic devices

Magnetic phase transitions in Ta/CoFeB/MgO multilayers

We study thin films and magnetic tunnel junction nanopillars based on Ta/Co$_{20}$Fe$_{60}$B$_{20}$/MgO multilayers by electrical transport and magnetometry measurements. These measurements suggest that an ultrathin magnetic oxide layer forms at the Co$_{20}$Fe$_{60}$B$_{20}$/MgO interface. At approximately 160 K, the oxide undergoes a phase transition from an insulating antiferromagnet at low temperatures to a conductive weak ferromagnet at high temperatures. This interfacial magnetic oxide is expected to have significant impact on the magnetic properties of CoFeB-based multilayers used in spin torque memories

Возможности сфинктеросохраняющего лечения больных местно-распространенным первично-неоперабельным раком прямой кишки

The aim of this study was to compare results of sphincter-sparing operations (SSO) and abdominoperineal resections (APR) in patients  undergoing combined treatment for unresectable locally-advanced rectal cancer.Methods. During September 2007 – January 2011 59 patients were enrolled. Original treatment scheme (RF patent № 2414936) was developed including radiotherapy 40 Gy in 4 Gy fractions, capecitabine 650 mg/m2 bid per os days 1-22, oxaliplatin 50 mg/m2 iv days 3, 10, 17, local hyperthermia on days 8, 12, 15, 17, 2 applications of metronidazole 10 g/m2 per rectum in a polymeric composition. Surgery was carried out following 6–8 weeks. SSO were carried out in 36 patients, APR in 23 patients. Study endpoints included 2-year OS and DFS, local recurrence and distant metastases rate, postoperative complications rate.Results. No significant differences in survival were observed: 2-year OS was 93.2 and 85.6 % (log- rank test p = 0.157) for SSO and APR groups accordingly, 2-year DFS was 88 and 71.9 % (log-rank test p = 0.064). Four (11.1 %) patients in SSO group and 4 (17.4 %) patients in APR group (р = 0.5511) developed local recurrences, 4 (11.1 %) and 7 (30.4 %) (р = 0.1293) developed distant metastases. Postoperative complications rate was 27.8 % (n = 10) and 39.1 % (n = 9) (р = 0.5181) in SSO and APR groups accordingly.Conclusions. Sphincter-sparting surgery is justified for unresectable locally advanced rectal cancer when technically feasible

Эпидемиология и статистика рака анального канала (обзор литературы)

In recent decades, there has been a marked increase in the incidence of anal cancer. The main risk factors for anal cancer include human papillomavirus infection, promiscuity, homosexuality in men, positive Papanicolaou test, and smoking.За последние десятилетия отмечается рост заболеваемости раком анального канала. Анализ показал, что развитие данной формы рака в большинстве случаев определяется такими факторами, как поражение вирусом папилломы человека, значительное число половых партнеров, половые взаимоотношения (гомосексуализм у мужчин), положительные результаты влагалищных мазков по Папаниколау, курение

Formation of "Lightnings" in a Neutron Star Magnetosphere and the Nature of RRATs

The connection between the radio emission from "lightnings" produced by the absorption of high-energy photons from the cosmic gamma-ray background in a neutron star magnetosphere and radio bursts from rotating radio transients (RRATs) is investigated. The lightning length reaches 1000 km; the lightning radius is 100 m and is comparable to the polar cap radius. If a closed magnetosphere is filled with a dense plasma, then lightnings are efficiently formed only in the region of open magnetic field lines. For the radio emission from a separate lightning to be observed, the polar cap of the neutron star must be directed toward the observer and, at the same time, the lightning must be formed. The maximum burst rate is related to the time of the plasma outflow from the polar cap region. The typical interval between two consecutive bursts is ~100 s. The width of a single radio burst can be determined both by the width of the emission cone formed by the lightning emitting regions at some height above the neutron star surface and by a finite lightning lifetime. The width of the phase distribution for radio bursts from RRATs, along with the integrated pulse width, is determined by the width of the bundle of open magnetic field lines at the formation height of the radio emission. The results obtained are consistent with the currently available data and are indicative of a close connection between RRATs, intermittent pulsars, and extreme nullers.Comment: 24 pages, no figures, references update

Сombined treatment of squamous-cell anal cancer

Since 1974 chemoradiation scheme proposed by Nigro remains the standard of care for squamous-cell anal cancer in most countries. Improvement of treatment results can be achieved by developing new treatment schemes including different radio- and chemosensitizers.Methods. Results of treatment of 157 T1–4N0–2M0 squamous-cell anal cancer patients, which underwent treatment during 1990–2012 were analyzed. Patients were divided into 3 groups: group A received hyperfractionated radiotherapy (RT) single dose 1.2 Gy bid, total dose 40–44 Gy with 3–5 sessions of local hyperthermia (HT) during treatment; group B had similar RT + HT scheme with addition of chemotherapy (CT) with cisplatin 20 mg/m2 in days 1, 3 weeks 1–4 and bleomycin 15 mg in days 2, 4 weeks 1–4; group C had RT with single dose 2 Gy, same total dose, HT and CT as in group B and additionally received metronidazole 10 g/m2 per rectum in a polymeric composition. Two weeks after 1st treatment stage a second course of RT was carried out 20–24 Gy in 2 Gy fractions in all patient groups.Results. Sphincter-sparing treatment was carried out in 11 (50 %), 71 (80.68 %) and 44 (93.62 %) in groups A, B and C accordingly. Three year overall survival (OS) was 60.0; 82.4; 96.4 %; 3-year disease-free survival (DFS) 36.6; 69.8 and 76.3 % accordingly.Conclusions. In our study combined treatment using radiosensitization allow to improve sphincter preservation rate to 93 %, improve OS and DFS for squamous-cell anal cancer patients

ORGAN-SPARING TREATMENT IN PATIENTS WITH SQUAMOUS CELL CARCINOMA OF THE ANAL CANAL

Objective: to improve the results of treatment in patients with squamous cell carcinoma of the anal canal, by creating a new combination treatment option, and to increase the rate of organ-sparing treatment.Subjects and methods. A new combination treatment option for squamous cell carcinoma of the anal canal was created, which involved a combination of radiotherapy and a multiple radio modification program (ultrahigh-frequency (UHF) hyperthermia and local metronidazole (MZ) injection and systemic polychemotherapy) (RF patent No. 2427399 “A treatment option for squamous cell carcinoma of the anal canal” registered on 27 August 2011). To evaluate the created treatment option, the latter was analyzed in 157 patients with Т1–4N0–3M0 squamous cell carcinoma of the anal canal, who had been treated in 1990 to 2012. In 22 patients, radiotherapy was performed in combination with 3–5 sessions of local UHF hyperthermia (thermoradiotherapy (TRT)); 88 patients received the latter in combination with polychemotherapy (thermoradiochemotherapy (TRCT)); in addition to TRCT, 47 patients used MZ (TRCT + MZ).Results. In the TRT, TRCT, and TRCT + MZ groups, organ-sparing treatment was performed in 11 (50 %), 71 (80.7 %), and 44 (93.6 %) patients, respectively. In these groups, the median follow-up was 18.6; 51.7, and 15.5 months, respectively. In the 3 groups, the three-year overall survival rates were 71.4; 90.0, and 96.3 % and the three-year relapse free survival rates were 46.7; 60.6, and 75.0 %, respectively.Conclusion. The created combination thermochemoradiotherapy involving a polymer combination with MZ (TRCT + MZ) makes it possible to achieve organ-sparing treatment in 93.6 % of the patients and to slightly improve 3-year overall and relapse-free survival rates in patients with squamous cell carcinoma of the anal canal who have received organ-sparing treatment although there is only a tendency for statistical survival difference in this patient group

Возможности сфинктеросохраняющего лечения больных местно-распространенным первично-неоперабельным раком прямой кишки

The aim of this study was to compare results of sphincter-sparing operations (SSO) and abdominoperineal resections (APR) in patients  undergoing combined treatment for unresectable locally-advanced rectal cancer.Methods. During September 2007 – January 2011 59 patients were enrolled. Original treatment scheme (RF patent № 2414936) was developed including radiotherapy 40 Gy in 4 Gy fractions, capecitabine 650 mg/m2 bid per os days 1-22, oxaliplatin 50 mg/m2 iv days 3, 10, 17, local hyperthermia on days 8, 12, 15, 17, 2 applications of metronidazole 10 g/m2 per rectum in a polymeric composition. Surgery was carried out following 6–8 weeks. SSO were carried out in 36 patients, APR in 23 patients. Study endpoints included 2-year OS and DFS, local recurrence and distant metastases rate, postoperative complications rate.Results. No significant differences in survival were observed: 2-year OS was 93.2 and 85.6 % (log- rank test p = 0.157) for SSO and APR groups accordingly, 2-year DFS was 88 and 71.9 % (log-rank test p = 0.064). Four (11.1 %) patients in SSO group and 4 (17.4 %) patients in APR group (р = 0.5511) developed local recurrences, 4 (11.1 %) and 7 (30.4 %) (р = 0.1293) developed distant metastases. Postoperative complications rate was 27.8 % (n = 10) and 39.1 % (n = 9) (р = 0.5181) in SSO and APR groups accordingly.Conclusions. Sphincter-sparting surgery is justified for unresectable locally advanced rectal cancer when technically feasible.  Целью данного исследования было провести сравнительный анализ результатов сфинктеросохраняющих операций (CCО) и брюшно-промежностных экстирпаций (БПЭ) прямой кишки в рамках комплексного лечения больных местно-распространенным первично-неоперабельным раком прямой кишки (РПК).Методы. С сентября 2007 г. по январь 2011 г. в исследование включено 59 пациентов. Создана оригинальная схема лечения (патент РФ № 2414936), включающая лучевую терапию с разовой очаговой дозой 4 Гр, суммарной очаговой дозой 40 Гр, химиотерапию капецитабином 650 мг/м2 per os 2 р/сут дни 1–22-й, оксалиплатином 50 мг/м2 в/в дни 3, 10, 17-й, локальную гипертермию в дни 8, 12, 15, 17-й, два введения метронидазола 10 г/м2 per rectum в составе полимерной композиции в дни 12-й, 17-й; операция выполнялась через 6–8 нед. ССО были выполнены 36 пациентам, БПЭ – 23 пациентам. Критериями оценки были общая и безрецидивная 2-летняя выживаемость, частота рецидивов и метастазов, частота послеоперационных осложнений.Результаты. Достоверных различий в показателях выживаемости не отмечено. Двухлетняя общая выживаемость в группах ССО и БПЭ составила 93,2 и 85,6 % (log-rank test, p = 0,157), 2-летняя безрецидивная выживаемость – 88 и 71,9 % (log-rank test, p = 0,064) соответственно. Рецидив РПК развился у 4 (11,1 %) пациентов в группе ССО и у 4 (17,4 %) пациентов в группе БПЭ (р = 0,5511), метастазы – у 4 (11,1 %) и 7 (30,4 %) пациентов соответственно (р = 0,1293). Частота послеоперационных  осложнений составила 27,8 % (n = 10) и 39,1 % (n = 9) (р = 0,5181) в группе ССО и БПЭ соответственно.Выводы. Проведение сфинктеросохраняющих операций оправданно с онкологической точки зрения у больных местно-распространенным первично-неоперабельным РПК