187 research outputs found
Therapeutic approach in glioblastoma multiforme with primitive neuroectodermal tumor components: case report and review of the literature
Glioblastoma multiforme (GBM) is the most common and aggressive malignant glioma that is treated with first-line therapy, using surgical resection followed by local radiotherapy and concomitant/adjuvant temozolomide (TMZ) treatment. GBM is characterised by a high local recurrence rate and a low response to therapy. Primitive neuroectodermal tumour (PNET) of the brain revealed a low local recurrence rate; however, it also exhibited a high risk of cerebrospinal fluid (CSF) dissemination. PNET is treated with surgery followed by craniospinal irradiation (CSI) and platinum-based chemotherapy in order to prevent CSF dissemination. GBM with PNET-like components (GBM/PNET) is an emerging variant of GBM, characterised by a PNET-like clinical behaviour with an increased risk of CSF dissemination; it also may benefit from platinum-based chemotherapy upfront or following failure of GBM therapy. The results presented regarding the management of GBM/PNET are based on case reports or case series, so a standard therapeutic approach for GBM/PNET is not defined, constituing a challenging diagnostic and therapeutic dilemma. In this report, a case of a recurrent GBM/PNET treated with surgical resection and radiochemotherapy as Stupp protocol, and successive platinum-based chemotherapy due to the development of leptomeningeal dissemintation and an extracranial metastasis, is discussed. A review of the main papers regarding this rare GBM variant and its therapeutic approach are also reported. In conclusion, GBM/PNET should be treated with a multimodal approach including surgery, chemoradiotherapy, and/or the early introduction of CSI and platinum-based chemotherapy upfront or at recurrence
Solitary Common Iliac Artery Inflammatory Aneurysm in a Healthy Woman: Case Report and Review of the Literature
Inflammatory aneurysms represent only 3–10% of all aortoiliac aneurysms and tend to be more common in men. We report a case of a solitary inflammatory aneurysm of the right common iliac artery in a healthy young woman. The patient presented with persistent abdominal and right flank pain. She had no risk factors for vascular disease, except mild hypertension and a strong family history of aneurysm disease. Her work-up demonstrated a 3.0 cm right common iliac artery aneurysm with intramural thrombus, focal calcification, and perianeurysmal inflammation without evidence of systemic atherosclerosis. There was right hydroureteronephrosis secondary to ureteral compression by the inflammatory aneurysm. She underwent open right common iliac artery aneurysmorraphy with polytetrafluoroethylene interposition graft and concomitant ureterolysis without complication. She remains asymptomatic more than 1 year postoperatively with no evidence of additional aneurysm disease, resolution of her hydroureteronephrosis, and normal kidney function. We report a rare case of a solitary inflammatory aneurysm of the right common iliac artery in a healthy young woman, with a review of the current literature on inflammatory aneurysms.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41370/1/10016_2005_Article_7713.pd
Upstaging nodal status in colorectal cancer using ex vivo fluorescence sentinel lymph node mapping: preliminary results
Background: Sentinel lymph node (SLN) mapping using near-infrared fluorescence (NIRF) imaging is a recent technique to improve nodal staging in several tumors. The presence of colorectal cancer (CRC) micro-metastases has recently been defined as N1 disease and no longer as N1mi, determining the need for adjuvant chemotherapy. In CRC, the reported rate of SLN micro-metastases detected by ultrastaging techniques is as high as 30%. The aim of this prospective study is to report the preliminary results of the sensitivity analysis of NIRF imaging for ex vivo SLN mapping and the research of micro-metastases in CRC, in patients with node-negative disease (NND). Material and methods: On the specimen of 22 CRC patients, 1 mL of ICG (5 mg/mL) was injected submucosally around the tumor to identify SLNs. NND SLNs were further investigated with ultrastaging techniques. Results: Three-hundred and sixty-three lymph nodes were retrieved (59 SLNs; mean per case: 2.7). The detection, sensitivity and false-negative rate were 100%, 100% and 0% respectively. Ultrastaging investigations showed no micro-metastases in the NND SLNs. Conclusions: The ex vivo SLN fluorescence-based detection in CRC was confirmed to be easy to perform and reliable. In this preliminary results report of an ongoing study, the SLN assay was congruent with the nodal status, as confirmed by histological investigations
PROviding Better ACcess To ORgans: A comprehensive overview of organ‐access initiatives from the ASTS PROACTOR Task Force
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138905/1/ajt14441_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/138905/2/ajt14441.pd
A study of surface currents in the spawning area of Brazilian sardine
To obtain the movement of surface currents in the spawning area of Brazilian sardine, drift card release experiments were conducted in south Brazilian waters during the spawning seasons of 1969-1971. The results of these experiments and some considerations about the drift of sardine eggs and larvae are described. On the cruises of late spring, summer and early autumn all cards from stations west of Long. 44º45' W drifted southwest and were recovered near São Sebastião and those from stations east of Long. 44º45' W drifted northeast and were recovered on the coast line between Ilha Grande and Cabo Frio. The drift pattern of the cruise of September 1969 was somewhat different from the others. Most cards recovered were released from stations near shore (up to 30 nm).O recrutamento do estoque de peixes marinhos é dependente da mortalidade, durante o estágio de ovos e larvas. A corrente de superfície, na área de desova, é um dos fatores importantes que afetam a mortalidade de larvas. O presente trabalho é o resultado de estudos feitos na corrente de superfície por meio de cartões-de-deriva, na região sul do Brasil (entre 22º S e 30º S). Oito viagens oceanográficas foram realizadas com os N/Oc. "Prof. W. Besnard" e "Emília" nos anos de 1969 a 1971. Na região de Ilha Grande, considerada uma das principais áreas de desova, o resultado na época do fim da primavera ao inicio do outono, mostra que os cartões lançados na área este de Long. 44º45' W, derivaram a nordeste e foram encontrados na costa, entre Ilha Grande e Cabo Frio e os cartões lançados na área oeste de Long. 44º45' W, derivaram a sudoeste e chegaram à costa de São Sebastião e Santos. O resultado do cruzeiro de setembro de 1969 (início da primavera) é diferente dos outros. Da região sul de Santos e da região do Cabo de São Tomé, temos poucos dados, portanto, não chegamos a uma conclusão definitiva. Será necessário o estudo contínuo desta área. A maioria dos cartões encontrados foram lançados de estações situadas perto da costa (no máximo, 30 mn). A maioria dos cartões, lançados a uma distância superior, nao foi recuperada
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Picosecond Avalanche Detector — working principle and gain measurement with a proof-of-concept prototype
The Picosecond Avalanche Detector is a multi-junction silicon pixel detector based on a (NP)drift(NP)gain structure, devised to enable charged-particle tracking with high spatial resolution and picosecond time-stamp capability. It uses a continuous junction deep inside the sensor volume to amplify the primary charge produced by ionizing radiation in a thin absorption layer. The signal is then induced by the secondary charges moving inside a thicker drift region. A proof-of-concept monolithic prototype, consisting of a matrix of hexagonal pixels with 100 μm pitch, has been produced using the 130 nm SiGe BiCMOS process by IHP microelectronics. Measurements on probe station and with a 55Fe X-ray source show that the prototype is functional and displays avalanche gain up to a maximum electron gain of 23. A study of the avalanche characteristics, corroborated by TCAD simulations, indicates that space-charge effects due to the large primary charge produced by the conversion of X-rays from the ^55Fe source limits the effective gain
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Testbeam results of the Picosecond Avalanche Detector proof-of-concept prototype
The proof-of-concept prototype of the Picosecond Avalanche Detector, a multi-PN junction monolithic silicon detector with continuous gain layer deep in the sensor depleted region, was tested with a beam of 180 GeV pions at the CERN SPS. The prototype features low noise and fast SiGe BiCMOS frontend electronics and hexagonal pixels with 100 μm pitch. At a sensor bias voltage of 125 V, the detector provides full efficiency and average time resolution of 30, 25 and 17 ps in the overall pixel area for a power consumption of 0.4, 0.9 and 2.7 W/cm2, respectively. In this first prototype the time resolution depends significantly on the distance from the center of the pixel, varying at the highest power consumption measured between 13 ps at the center of the pixel and 25 ps in the inter-pixel region
20 ps Time Resolution with a Fully-Efficient Monolithic Silicon Pixel Detector without Internal Gain Layer
A second monolithic silicon pixel prototype was produced for the MONOLITH
project. The ASIC contains a matrix of hexagonal pixels with 100 {\mu}m pitch,
readout by a low-noise and very fast SiGe HBT frontend electronics. Wafers with
50 {\mu}m thick epilayer of 350 {\Omega}cm resistivity were used to produce a
fully depleted sensor. Laboratory and testbeam measurements of the analog
channels present in the pixel matrix show that the sensor has a 130 V wide
bias-voltage operation plateau at which the efficiency is 99.8%. Although this
prototype does not include an internal gain layer, the design optimised for
timing of the sensor and the front-end electronics provides a time resolutions
of 20 ps.Comment: 11 pages, 11 figure
Testbeam Results of the Picosecond Avalanche Detector Proof-Of-Concept Prototype
The proof-of-concept prototype of the Picosecond Avalanche Detector, a
multi-PN junction monolithic silicon detector with continuous gain layer deep
in the sensor depleted region, was tested with a beam of 180 GeV pions at the
CERN SPS. The prototype features low noise and fast SiGe BiCMOS frontend
electronics and hexagonal pixels with 100 {\mu}m pitch. At a sensor bias
voltage of 125 V, the detector provides full efficiency and average time
resolution of 30, 25 and 17 ps in the overall pixel area for a power
consumption of 0.4, 0.9 and 2.7 W/cm^2, respectively. In this first prototype
the time resolution depends significantly on the distance from the center of
the pixel, varying at the highest power consumption measured between 13 ps at
the center of the pixel and 25 ps in the inter-pixel region
Radiation Tolerance of SiGe BiCMOS Monolithic Silicon Pixel Detectors without Internal Gain Layer
A monolithic silicon pixel prototype produced for the MONOLITH ERC Advanced
project was irradiated with 70 MeV protons up to a fluence of 1 x 10^16 1 MeV
n_eq/cm^2. The ASIC contains a matrix of hexagonal pixels with 100 {\mu}m
pitch, readout by low-noise and very fast SiGe HBT frontend electronics. Wafers
with 50 {\mu}m thick epilayer with a resistivity of 350 {\Omega}cm were used to
produce a fully depleted sensor. Laboratory tests conducted with a 90Sr source
show that the detector works satisfactorily after irradiation. The
signal-to-noise ratio is not seen to change up to fluence of 6 x 10^14 n_eq
/cm^2 . The signal time jitter was estimated as the ratio between the voltage
noise and the signal slope at threshold. At -35 {^\circ}C, sensor bias voltage
of 200 V and frontend power consumption of 0.9 W/cm^2, the time jitter of the
most-probable signal amplitude was estimated to be 21 ps for proton fluence up
to 6 x 10 n_eq/cm^2 and 57 ps at 1 x 10^16 n_eq/cm^2 . Increasing the sensor
bias to 250 V and the analog voltage of the preamplifier from 1.8 to 2.0 V
provides a time jitter of 40 ps at 1 x 10^16 n_eq/cm^2.Comment: Submitted to JINS
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