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Femtosecond Pump-Probe Diagnostics Of Preformed Plasma Channels
We report on recent ultrafast pump-probe experiments 28 in He plasma waveguides using 800 nm, 80 fs pump pulses of 0.2 x 1018 W/cm2 peak guided intensity, and single orthogonally-polarized 800 nm probe pulses with similar to0.1% of pump intensity. The main results are: (1) We observe frequency-domain interference between the probe and a weak, depolarized component of the pump that differs substantially in mode shape from the injected pump pulse; (2) we observe spectral blue-shifts in the transmitted probe that are not evident in the transmitted pump. The evidence indicates that pump depolarization and probe blue-shifts both originate near the channel entrance.Physic
Ion therapy within the trimodal management of superior sulcus tumors: the INKA trial
Background: The standard trimodal treatment concept in locally advanced and non-metastasized non-small-cell superior sulcus tumors consists of a preoperative chemoradiation followed by surgical resection. High linear energy transfer (LET) radiation as, for example, C12 heavy-ion beam therapy theoretically offers biological advantages compared to high energy x-ray therapy as, for example, higher biological efficiency. Methods/Design: In the present prospective, single-armed, open pilot study performed at the Heidelberg Ion-Beam Therapy Center (HIT) in Heidelberg, the radiation treatment within the standard trimodal concept will be exchanged against C12 heavy-ion beam treatment and apply 39GyE in 13 single fractions in combination with a chemotherapy consisting of cisplatin and vinorelbine (local standard). The primary endpoint is feasibility and safety measured by the incidence of NCI-CTCAE grade 3/4 toxicity and/or discontinuation due to any reason. Secondary endpoint is the degree of regression in the histological specimen. The main inclusion criteria are histologically confirmed non-small-cell superior sulcus tumor, nodal disease stage ≤ N2, Karnofsky performance score ≥70%, patient age between 18 and 75 years as well as written informed consent. The main exclusion criteria include medical contraindications against elements of the trimodal treatment concept, PET confirmed nodal disease stage N3, stage IV disease, prior thoracic irradiation and decompensated diseases of the lung, cardio-vascular system, metabolism, hematopoietic and coagulation system and renal function. Furthermore, patients with implanted active medical devices without certification for ion-beam therapy are not allowed to take part in the study. Trial registration number: DRKS00006323 (www.drks.de)
Spin diffusion in the Mn2+ ion system of II-VI diluted magnetic semiconductor heterostructures
The magnetization dynamics in diluted magnetic semiconductor heterostructures
based on (Zn,Mn)Se and (Cd,Mn)Te has been studied experimentally by optical
methods and simulated numerically. In the samples with nonhomogeneous magnetic
ion distribution this dynamics is contributed by spin-lattice relaxation and
spin diffusion in the Mn spin system. The spin diffusion coefficient of
7x10^(-8) cm^2/s has been evaluated for Zn(0.99)Mn(0.01)Se from comparison of
experimental and numerical results. Calculations of the giant Zeeman splitting
of the exciton states and the magnetization dynamics in the ordered alloys and
parabolic quantum wells fabricated by the digital growth technique show perfect
agreement with the experimental data. In both structure types the spin
diffusion has an essential contribution to the magnetization dynamics.Comment: 12 pages, 11 figure
Menstrual hygiene management to improve the attendance of primary school-aged girls in Central North, Burkina Faso
How to improve the conditions for girls to attend school, to reduce failure and drop-out rates of
adolescent girls, while ensuring their dignity and protection? This was the consideration that motivated
the Kom-Yilma project, implemented by Catholic Relief Services in Burkina Faso and financed by the
Leona M. and Harry B. Helmsley Charitable Trust, to undertake a behavior-change strategy for
menstrual-hygiene management in 118 schools in Bam and Sanmatenga Provinces. Discussions and
behavior-change communication activities, providing an appropriate space for girls and the active
participation of women leaders have already demonstrated positive results for a subject generally
considered taboo in the intervention zone
Neurological outcome after emergency radiotherapy in MSCC of patients with non-small cell lung cancer - a prospective trial
Background: The aim of this trial was to investigate neurological outcome after emergency RT in MSCC of NSCLC patients with acute neurological deficit. Methods This pilot trial was prospective, non-randomized, and monocentre, ten patients were treated from July 2012 until June 2013. After onset of neurological symptoms RT was started within 12 hours. The neurological outcome was assessed at baseline, and six weeks after RT using the ASIA Impairment Scale (AIS). Results: The results showed an improved neurological outcome in one patient (10%), one patient (10%) had a decreased, and five patients (50%) a constant outcome after six weeks. Three patients (30%) died within the first six weeks following RT, additional 4 patients (40%) died within 4 month due to tumor progression. Conclusion: In this group of NSCLC patients we were able to show that emergency RT in MSCC with acute neurological deficit had no considerable benefit in neurological outcome. Therefore, short-course regime or best supportive care due to poor survival should be considered for these patients with additional distant metastases. Patients with favorable prognosis may be candidates for long-course RT. Trial Registration: Clinical trial identifier http://www.clinicaltrials.gov
A treatment planning intercomparison of proton and intensity modulated photon radiotherapy.
peer reviewedAbstract
Purpose: A comparative treatment planning study has been undertaken between standard photon delivery techniques,b intensity modulated photon methods and spot scanned protons in order to investigate the merits and limitations of each of these treatment approaches.
Methods: Plans for each modality were performed using CT scans and planning information for nine patients with varying indications and lesion sites and the results have been analysed using a variety of dose and volume based parameters.
Results: Over all cases, it is predicted that the use of protons could lead to a reduction of the total integral dose by a factor three compared to standard photon techniques and a factor two compared to IM photon plans. In addition, in all but one Organ at Risk (OAR) for one case, protons are predicted to reduce both mean OAR dose and the irradiated volume at the 50% mean target dose level compared to both photon methods. However, when considering the volume of an OAR irradiated to 70% or more of the target dose, little difference could be shown between proton and intensity modulated photon plans. On comparing the magnitude of dose hot spots in OARs resulting from the proton and IM photon plans, more variation was observed, and the ranking of the plans was then found to be case and OAR dependent.
Conclusions: The use of protons has been found to reduce the medium to low dose load (below about 70% of the target dose) to OARs and all non-target tissues compared to both standard and inversely planned photons, but that the use of intensity modulated photons can result in similar levels of high dose conformation to that afforded by protons. However, the introduction of inverse planning methods for protons is necessary before general conclusions on the relative efficacy of photons and protons can be drawn
In Vivo Evaluation of a New Hybrid Graft Using Retrograde Visceral Perfusion for Thoracoabdominal Aortic Repair in an Animal Model
OBJECTIVES: The SPIDER technique for hybrid thoracoabdominal aortic aneurysm repair can avoid thoracotomy and extracorporeal circulation. To improve technical feasibility and safety, the new Thoracoflo graft, consisting of a proximal stent graft connected to a 7-branched abdominal prosthesis, was evaluated in a pig model for technical feasibility testing, before implantation in humans.
METHODS: Retroperitoneal exposure of the infradiaphragmatic aorta, including visceral and renal arteries, was performed in 7 pigs (75-85 kg). One iliac branch was temporarily attached to the distal aorta to maintain retrograde visceral and antegrade iliac perfusion after deployment of the thoracic stent graft segment (SPIDER technique). The proximal stent-grafted segment was deployed in the thoracic aorta via direct aortic puncture over the wire without fluoroscopy. The graft was deaired before flow via the iliac side branch to the visceral and iliac arteries was established. Visceral, renal, and lumbar arteries were subsequently sutured to the corresponding side branches of the graft. Technical feasibility, operating and clamping time, blood flow, and tissue perfusion in the related organs were evaluated before implantation and after 3 and 6 hours using transit-time flow measurement and fluorescent microspheres. Final angiography or postprocedural computed tomography angiography were performed.
RESULTS: Over-the-wire graft deployment was successful in 6 animals without hemodynamic alteration (
CONCLUSIONS: Over-the-wire implantation of the Thoracoflo graft using the SPIDER technique is feasible in a pig model. No fluoroscopy was required. For safe implantation, it is mandatory to follow the single steps of implantation
Adjuvant radiotherapy and chemoradiation with gemcitabine after R1 resection in patients with pancreatic adenocarcinoma
Background: The purpose of the study was to evaluate the effect of radiation therapy and chemoradiation with gemcitabine (GEM) after R1 resection in patients with pancreatic adenocarcinoma (PAC). Methods: We performed a retrospective analysis of 25 patients who were treated with postoperative radiotherapy (RT) or chemoradiation (CRT) after surgery with microscopically positive resection margins for primary pancreatic cancer (PAC). Median age was 60 years (range 34 to 74 years), and there were 17 male and 8 female patients. Fractionated RT was applied with a median dose of 49.6 Gy (range 36 to 54 Gy). Eight patients received additional intraoperative radiotherapy (IORT) with a median dose of 12 Gy. Results: Median overall survival (mOS) of all treated patients was 22 months (95% confidence interval (CI) 7.9 to 36.1 months) after date of resection and 21.1 months (95% CI 7.6 to 34.6 months) after start of (C)RT. Median progression-free survival (mPFS) was 13.0 months (95% CI 0.93 to 25 months). Grading (G2 vs. G3, P = 0.005) and gender (female vs. male, P = 0.01) were significantly correlated with OS. There was a significant difference in mPFS between male and female patients (P = 0.008). A total of 11 from 25 patients experienced local tumour progression, and 19 patients were diagnosed with either locoregional or distant failure. Conclusions: We demonstrated that GEM-based CRT can be applied in analogy to neoadjuvant protocols in the adjuvant setting for PAC patients at high risk for disease recurrence after incomplete resection. Patients undergoing additive CRT have a rather good OS and PFS compared to historical control patient groups
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