131 research outputs found
Nuevas especies de mamíferos para el Bajo Delta del Paraná y bajíos ribereños adyacentes, Buenos Aires, Argentina
Se reportan los primeros registros de presencia para cuatro especies de mamíferos (Dasypus novemcinctus, Cerdocyon thous, Procyon cancrivorus y Axis axis) en el sector bonaerense del Bajo Delta del río Paraná y bajíos ribereños adyacentes, Argentina. La inexistencia de datos previos para estas especies en la zona, pese a que se trata de un área previamente bien relevada, sugiere que su ingreso habría sido reciente. El número de registros obtenidos, su dispersión en el área y las observaciones de los pobladores respecto de la frecuencia de avistajes sugerirían que estas especies poseen actualmente poblaciones establecidas en la zona.We report the first records of presence of four mammal species (Dasypus novemcinctus, Cerdocyon thous, Procyon cancrivorus, and Axis axis) for the Lower Delta of the Paraná river and adjacent coastal lowlands, Buenos Aires province, Argentina. The absence of previous records of these species in the area, although it is a previously well surveyed area, suggests that their dissemination would be recent. The obtained number of records, their dispersion in the area, and comments from local people regarding the frequency of sightings would suggest that these species currently have established populations in the area.EEA Delta del ParanáFil: Fracassi, Natalia. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Delta del Paraná; ArgentinaFil: Fracassi, Natalia. Asociación para la Conservación y el Estudio de la Naturaleza; ArgentinaFil: Moreyra, Pedro A. Administración de Parques Nacionales. Parque Nacional Campos del Tuyú; ArgentinaFil: Lartigau, Bernardo V. Asociación para la Conservación y el Estudio de la Naturaleza; ArgentinaFil: Teta, Pablo. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; ArgentinaFil: Landó, Roberto. FAPLAC S.A.; ArgentinaFil: Pereira, Javier A. Asociación para la Conservación y el Estudio de la Naturaleza; ArgentinaFil: Pereira, Javier A. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; Argentin
Janus organic semiconductor nanoparticles prepared by simple nanoprecipitation
Nanoparticles (NPs) of donor–acceptor organic semiconductors are produced by a one-step nanoprecipitation with Janus morphology. Electron donor P3HT was blended with electron acceptor PC61BM in tetrahydrofuran and then precipitated in water, first with surfactant and second without surfactant. Cryogenic transmission electron microscopy reveals an internal Janus structure at high magnification, for NPs which have, in the past, been reported to have a molecularly intermixed morphology. Synchrotron-based scanning transmission X-ray microscopy confirmed the segregation of the organic semiconductors and photoluminescence experiments showed an efficient electron transfer from P3HT to PC61BM. Organic field effect transistors were fabricated with these Janus NPs and showed that the positive charges can be efficiently transported through thin films. This behavior proves that the NPs possess an electron-accepting face (the PC61BM face) able to transport electrons and a hole-accepting face (the P3HT face) for the conduction of holes. Finally, the deposition of silver via the photoreduction of a silver salt (AgNO3(aq)) was demonstrated, as a proof of concept. These experiments show the potential of the Janus NPs for photovoltaics but also photocatalytic reactions in which reduction and oxidation reactions can occur at opposite sides of the nanoreactor (the individual Janus NPs).E2SEncres aqueuses colloïdales de semi-conducteurs organiques pour le photovoltaïqu
Split Course Hyperfractionated Accelerated Radio-Chemotherapy (SCHARC) for patients with advanced head and neck cancer: Influence of protocol deviations and hemoglobin on overall survival, a retrospective analysis
BACKGROUND: The advantage of hyperfractionated accelerated radiation therapy for advanced head and neck cancer has been reported. Furthermore, randomized trials and meta-analyses have confirmed the survival benefit of additional chemotherapy to radiotherapy. We retrospectively analyzed the efficiency and toxicity of the Regensburg standard therapy protocol "SCHARC" and the overall survival of our patients. METHODS: From 1997 to 2004, 64 patients suffering from advanced head and neck cancer (88 % stage IV, 12 % stage III) were assigned to receive the SCHARC protocol. Around half of the patients were diagnosed with oro-hypopharynx carcinoma (52 %), one third with tongue and floor of mouth tumors (29 %) and one fifth (19 %) suffered from H & N cancer at other sites. The schedule consisted of one therapy block with 30 Gy in 20 fractions over a two week period with concomitant chemotherapy (d 1–5: 20 mg/m(2)/d DDP + 750–1000 mg/m(2)/d 5FU (cont. infusion). This therapy block was repeated after a fortnight break up to a cumulative dose of 60 Gy and followed by a boost up to 70 Gy (69–70.5 Gy). All patients assigned to this scheme were included in the survival evaluation. RESULTS: Forty patients (63 %) received both radiation and chemotherapy according to the protocol. The mean follow up was 2.3 years (829 d) and the median follow up was 1.9 years (678 d), respectively. The analysis of survival revealed an estimated 3 year overall survival rate of 57 %. No patient died of complications, 52 patients (80 %) had acute grade 2–3 mucositis, and 33 patients (58 %) suffered from acute grade 3 skin toxicity. Leucopenia was no major problem (mean nadir 3.4 g/nl, no patient < 1.0 g/nl) and the mean hemoglobin value decreased from 13.2 to 10.5 g/dl. Univariate analysis of survival showed a better outcome for patients with a hemoglobin nadir >10.5 g/dl and for patients who completed the protocol. CONCLUSION: The SCHARC protocol was effective in patients diagnosed with advanced head and neck cancer. It led to long-term disease control and survival in about 50 % of the patients with significant but acceptable toxicity. Most patients were not anemic at beginning of therapy. Therefore, we could assess the influence of pre-treatment hemoglobin on survival. However, a low hemoglobin nadir was associated with poor outcome. This result suggests an influence of anemia during therapy on prognosis
Stabilité thermique de la couche active d’une cellule solaire organique par réticulation
Date du colloque : 11/2012</p
Adjuvant radiation therapy in metastatic lymph nodes from melanoma
<p>Abstract</p> <p>Purpose</p> <p>To analyze the outcome after adjuvant radiation therapy with standard fractionation regimen in metastatic lymph nodes (LN) from cutaneous melanoma.</p> <p>Patients and methods</p> <p>86 successive patients (57 men) were treated for locally advanced melanoma in our institution. 60 patients (69%) underwent LN dissection followed by radiation therapy (RT), while 26 patients (31%) had no radiotherapy.</p> <p>Results</p> <p>The median number of resected LN was 12 (1 to 36) with 2 metastases (1 to 28). Median survival after the first relapse was 31.8 months. Extracapsular extension was a significant prognostic factor for regional control (p = 0.019). Median total dose was 50 Gy (30 to 70 Gy). A standard fractionation regimen was used (2 Gy/fraction). Median number of fractions was 25 (10 to 44 fractions). Patients were treated with five fractions/week. Patients with extracapsular extension treated with surgery followed by RT (total dose ≥50 Gy) had a better regional control than patients treated by surgery followed by RT with a total dose <50 Gy (80% vs. 35% at 5-year follow-up; p = 0.004).</p> <p>Conclusion</p> <p>Adjuvant radiotherapy was able to increase regional control in targeted sub-population (LN with extracapsular extension).</p
Effect of Culture at Low Oxygen Tension on the Expression of Heat Shock Proteins in a Panel of Melanoma Cell Lines
Tumours are commonly hypoxic and this can be associated with aggressive tumour type, metastasis and resistance to therapy. Heat shock proteins (hsps) are induced in response to hypoxia, provide cancer cells with protection against tumour-associated stressors and chaperone oncoproteins that drive tumour proliferation. This study examined the effect of different oxygen concentrations on the expression of hsps in melanoma cell lines.Melanoma cell lines were cultured in 2% and 20% O(2). Expression of Hsp90, Hsp70, Hsp60, Hsp40 and Hsp32 proteins were determined by flow cytometry.Growth rates and viability were reduced in the majority of cell lines by culture in 2% O(2). Hsp expression was different in 2% compared to 20% O(2) and changes in Hsp90 expression correlated with cell line generation time (P<0.005) and viability (P<0.01). Greater total hsp expression correlated with improved viability in 2% but not 20% O(2) (P<0.05). Relative expression of the different hsps was consistent across cell lines and each correlated with the others (P = 0.0001) but not with Hsp32. Hsp expression was inversely correlated with cell line adhesion to laminin as well as collagen type IV and Breslow depth of the original primary tumour tissue (P<0.05), but not with Clark level or patient survival. All five hsps were identified on the cell surface.Culture in 2% O(2) variably altered hsp expression in a panel of melanoma cell lines. Hsp expression was associated with certain cell line characteristics and clinical parameters of the originating tumour
Experience Feedback Committee: a management tool to improve patient safety in mental health
BACKGROUND: A management tool, called the Experience Feedback Committee, has been applied for patient safety and successfully used in medical departments. The purpose of this study was to analyse the functioning of an Experience Feedback Committee in a psychiatric department and to explore its contribution to the particular issues of patient safety in mental health. METHODS: We conducted a descriptive study based on all the written documents produced by the Experience Feedback Committee between March 2010 and January 2013. The study was conducted in Grenoble University Hospital in France. We analysed all reported incidents, reports of meetings and event analysis reports. Adverse events were classified according to the Conceptual Framework for the International Classification for Patient Safety. RESULTS: A total of 30 meetings were attended by 22 professionals including seven physicians and 12 paramedical practitioners. We identified 475 incidents reported to the Experience Feedback Committee. Most of them (92 %) had no medical consequence for the patient. Eleven incidents were investigated with an analysis method inspired by civil aviation security systems. Twenty-one corrective actions were set up, including eight responses to the specific problems of a mental health unit, such as training to respond to situations of violence or management of suicide attempts. CONCLUSIONS: The Experience Feedback Committee makes it possible to involve mental healthcare professionals directly in safety management. This tool seems appropriate to manage specific patient safety issues in mental health. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12991-015-0062-2) contains supplementary material, which is available to authorized users
Intensity-modulated radiotherapy versus stereotactic body radiotherapy for prostate cancer (PACE-B): 2-year toxicity results from an open-label, randomised, phase 3, non-inferiority trial
Background
Localised prostate cancer is commonly treated with external beam radiotherapy and moderate hypofractionation is non-inferior to longer schedules. Stereotactic body radiotherapy (SBRT) allows shorter treatment courses without impacting acute toxicity. We report 2-year toxicity findings from PACE-B, a randomised trial of conventionally fractionated or moderately hypofractionated radiotherapy versus SBRT.
Methods
PACE is an open-label, multicohort, randomised, controlled, phase 3 trial conducted at 35 hospitals in the UK, Ireland, and Canada. In PACE-B, men aged 18 years and older with a WHO performance status 0–2 and low-risk or intermediate-risk histologically-confirmed prostate adenocarcinoma (Gleason 4 + 3 excluded) were randomly allocated (1:1) by computerised central randomisation with permuted blocks (size four and six), stratified by centre and risk group to control radiotherapy (CRT; 78 Gy in 39 fractions over 7·8 weeks or, following protocol amendment on March 24, 2016, 62 Gy in 20 fractions over 4 weeks) or SBRT (36·25 Gy in five fractions over 1–2 weeks). Androgen deprivation was not permitted. Co-primary outcomes for this toxicity analysis were Radiation Therapy Oncology Group (RTOG) grade 2 or worse gastrointestinal and genitourinary toxicity at 24 months after radiotherapy. Analysis was by treatment received and included all patients with at least one fraction of study treatment assessed for late toxicity. Recruitment is complete. Follow-up for oncological outcomes continues. The trial is registered with ClinicalTrials.gov, NCT01584258.
Findings
We enrolled and randomly assigned 874 men between Aug 7, 2012, and Jan 4, 2018 (441 to CRT and 433 to SBRT). In this analysis, 430 patients were analysed in the CRT group and 414 in the SBRT group; a total of 844 (97%) of 874 randomly assigned patients. At 24 months, RTOG grade 2 or worse genitourinary toxicity was seen in eight (2%) of 381 participants assigned to CRT and 13 (3%) of 384 participants assigned to SBRT (absolute difference 1·3% [95% CI –1·3 to 4·0]; p=0·39); RTOG grade 2 or worse gastrointestinal toxicity was seen in 11 (3%) of 382 participants in the CRT group versus six (2%) of 384 participants in the SBRT group (absolute difference –1·3% [95% CI –3·9 to 1·1]; p=0·32). No serious adverse events (defined as RTOG grade 4 or worse) or treatment-related deaths were reported within the analysis timeframe.
Interpretation
In the PACE-B trial, 2-year RTOG toxicity rates were similar for five fraction SBRT and conventional schedules of radiotherapy. Prostate SBRT was found to be safe and associated with low rates of side-effects. Biochemical outcomes are awaited
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