2,032 research outputs found
Abdominopelvic Splenosis—An Unusual Cause of Tenesmus
Splenosis is a rare condition defined as seeding and autotransplantation of splenic tissue, typically after blunt
abdominal trauma (e.g. from road traffic collision). Sites of splenosis ranging from intrathoracic to intrapelvic have
been reported, and symptoms vary greatly depending on the site and size of lesions. We present the use of Tc-99m
sulphur colloid SPECT/CT in diagnosing a case of multiple abdominopelvic splenosis as the cause of new-onset
tenesmus and constipation, which was initially thought to be due to colorectal malignancy, 47 years following the
initial abdominal trauma
Update in management of hepatocellular carcinoma in Eastern population
Hepatocellular carcinoma (HCC) is one of the commonest malignant tumours in the East. Although the management of HCC in the West is mainly based on the Barcelona Clinic for Liver Cancer staging, it is considered too conservative by Asian countries where the number of HCC patients is huge. Scientific and clinical advances were made in aspects of diagnosis, staging, and treatment of HCC. HCC is well known to be associated with cirrhosis and the treatment of HCC must take into account the presence and stage of chronic liver disease. The major treatment modalities of HCC include: (1) surgical resection; (2) liver transplantation; (3) local ablation therapy; (4) transarterial locoregional treatment; and (5) systemic treatment. Among these, resection, liver transplantation and ablation therapy for small HCC are considered as curative treatment. Portal vein embolisation and the associating liver partition with portal vein ligation for staged hepatectomy may reduce dropout in patients with marginally resectable disease but the midterm and long-term results are still to be confirmed. Patient selection for the best treatment modality is the key to success of treatment of HCC. The purpose of current review is to provide a description of the current advances in diagnosis, staging, preoperative liver function assessment and treatment options for patients with HCC in the east. © 2015 Baishideng Publishing Group Inc.published_or_final_versio
Novel neighborhood search for multiprocessor scheduling with pipelining
Presents a neighborhood search algorithm for heterogeneous multiprocessor scheduling in which loop pipelining is used to exploit parallelism between iterations. The method adopts a realistic model for interprocessor communication where resource contention is taken into consideration. The schedule representation scheme is flexible so that communication scheduling can be performed in a generic manner. Based on a general time formulation of the schedule performance, the algorithm improves an initial schedule in an efficient way. Experimental results show that significant improvement over existing methods can be obtained. Using the scheduling results, a parallel software video encoder was implemented and real-time performance was achieved.published_or_final_versio
Parallelization methodology for video coding - an implementation on the TMS320C80
This paper presents a parallelization methodology for video coding based on the philosophy of hiding as much communications by computation as possible. It models the task/data size, processor cache capacity, and communication contention, through a systematic decomposition and scheduling approach. With the aid of Petri-nets and task graphs for representation and analysis, it employs a triple buffering scheme to enable the functions of frame capture, management, and coding to be performed in parallel. The theoretical speedup analysis indicates that this method offers excellent communication hiding, resulting in system efficiency well above 90%. To prove its practicality, a H.261 video encoder has been implemented on a TMS320C80 system using the method. Its performance was measured, from which the speedup and efficiency figures were calculated. The only difference detected between the theoretical and measured data is the program control overhead that has not been accounted for in the theoretical model. Even with this, the measured speedup of the H.261 is 3.67 and 3.76 on four parallel processors (PPs) for QCIF and 352 × 240 video, respectively, which correspond to frame rate of 30.7 and 9.25 frames per second, and system efficiency of 91.8% and 94%, respectively. This method is particularly efficient for platforms with small number of parallel processors.published_or_final_versio
Adaptive parallel video-coding algorithm
Parallel encoding of video inevitably frame rate gives varying rate performance due to dynamically changing video content and motion field since the encoding process of each macro-block, especially motion estimation, is data dependent. A multiprocessor schedule optimized for a particular frame with certain macro-block encoding time may not be optimized towards another frame with different encoding time, which causes performance degradation to the parallelization. To tackle this problem, we propose a method based on a batch of near-optimal schedules generated at compile-time and a run-time mechanism to select the schedule giving the shortest predicted critical path length. This method has the advantage of being near-optimal using compile-time schedules while involving only run-time selection rather than re-scheduling. Implementation on the IBM SP2 multiprocessor system using 24 processors gives an average speedup of about 13.5 (frame rate of 38.5 frames per second) for a CIF sequence consisting of segments of 6 different scenes. This is equivalent to an average improvement of about 16.9% over the single schedule scheme with schedule adapted to each of the scenes. Using an open test sequence consisting of 8 video segments, the average improvement achieved is 13.2%, i.e. an average speedup of 13.3 (35.6 frames per second).published_or_final_versio
Purinergic signalling during rat embryonic development
Adenosine 5'-triphosphate (ATP) has been shown to be an important extracellular signaling
molecule that mediates various physiological activities via the P2 (P2X and P2Y) receptors.
However, information on the expression patterns of the P2 receptors during mammalian
embryogenesis is limited. We therefore examined the expression patterns of different P2
receptor subtypes in rat embryos. In the hindbrain neural tube, the P2X3 receptor was
transiently expressed at embryonic day E11 in the cranial motor neurons and the outgrowing
axons. ATP significantly inhibited neurite outgrowth from neural tube explants. P2X3
receptors were also prominently expressed in sensory ganglia at this early stage and were
coexpressed with P2X2 receptors in E16.5 embryos. Other P2X receptor subtypes were
observed in different brain regions such as subventricular zones, the site of postnatal
neurogenesis. In addition, the P2Y receptor expression was detected in the somites and
subsequently in the developing skeletal muscle but was downregulated as development
proceeded. While the P2Y1 receptor was no longer expressed in the adult skeletal muscle, the
expression of P2Y2 receptor was present, although restricted in the satellite cells and the P2Y4
receptor showed reduced expression in adult skeletal muscle. Likewise, the expression of the
P2Y receptors was initially expressed throughout the myocardium (E12) but was gradually
restricted to the trabeculated myocardium (E14-18). Studies on Ca2+ influx showed that particular P2 receptor subtypes of P2X2, P2X4, P2Yi, P2Y2, P2Y4 and P2Y6 receptors
responded to nucleotides in E14 cardiomyocytes. P2X7 receptor expression was detected in
developing pancreatic islet cells and later coexpressed with glucagon in a-cells. In addition,
transient expression of the P2X7 receptor in insulin-expressing cells was observed in the
embryonic, but not in adult, islet cells. Together, the results indicated that widespread and
dynamic expression of P2 receptors was found in the three-germ layer-derived embryonic
tissues, particularly in some transient embryonic structures during development, which
suggested they may be important in embryonic organogenesis
Complete genomic sequence of Epstein-Barr virus in nasopharyngeal carcinoma cell line C666-1
published_or_final_versio
The development and initial validation of the Chinese Significant Wish Fulfillment Scale
This paper reports the development and validation of the Chinese Significant Wish Fulfillment Scale (CSWFS), a new multidimensional scale for assessing the perceived importance and level of fulfillment of wishes of older adults. Three studies were involved. Study 1 developed a 26-item pool on wish fulfillment through in-depth interviews with 22 older adults. Study 2 reduced the pool to 23 items through validation with a new sample of 315 older adults and examined the internal reliability. Study 3 involved a confirmatory factor analysis (CFA) and examined the test-retest reliability and the convergent validity of the scale with the construct of regret. A five-factor structure model of 23 items was identified through exploratory factor analysis, which accounted for 51.67% of variance. As informed by the CFA in Study 3, a five-factor 22-item model was the best fit. Internal reliability and test-retest reliability was found to be good. Convergent validity was examined through correlation with the construct of future regret. The correlation, though statistically significant, was small. CSWFS demonstrates good psychometric properties, but the construct might be slightly different from that of future regrets. Probably, CSWFS addresses a construct that is under-explored but is of importance to older adults and especially to the Chinese community.published_or_final_versio
Enhanced supercontinuum generation by minute continuous wave seed
Nonlinear Frequency Generation and Conversion: Materials, Devices, and Applications XIt is well-known that the properties of the supercontinuum (SC) radiation depend critically on the initial pumping conditions. For instance, if the SC is initiated by noise, namely modulation instability (MI), statistically rare "rogue waves" can be observed with sizable spectral broadening and intensity enhancement in SC. Interestingly, such rouge events can be actively controlled by adding an external weak pulse or by modulating the pump-pulse envelopes. In contrast, we here present that a simple triggering mechanism using an extremely weak continuous wave (CW) can also achieve such "rogue" enhancement. We experimentally demonstrated that a weak CW trigger (∼200,000×weaker than pump) can considerably broaden the SC bandwidth compared to the untriggered SC case (∼100 nm wider). Such enhancement was found to occur when the CW trigger's wavelength falls roughly within the modulation instability gain bandwidth. CW triggering also significantly alters the SC amplitude statistics, i.e. from extreme-value statistics in the untriggered SC to almost normal distribution in the triggered SC. Interferometric measurements also revealed the improvement in the SC coherence when the SC is CW-triggered. The enhanced SC by minute CW triggering only requires the CW-wavelength tuning for optimization and eliminates the necessity of high-precision (down to picoseconds) timing between the pump and the seed as in the pulse-seeding case. It thus offers a more convenient and practical approach to realize an enhanced and stable SC for many applications, especially in which real-time, ultrafast and single-shot spectroscopic measurements are essential. © 2011 SPIE.published_or_final_versio
Fast swept-source generation based on fiber optical parametric amplifier
We experimentally demonstrate a fast frequency swept-source using the dispersive Fourier transformation-based fiber optical parametric amplifier. The swept rate is as high as 78 MHz, with a linewidth of 0.135 nm. © 2011 OSA.published_or_final_versio
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