1,365 research outputs found

    Enzyme activity and electrophoretic pattern of isoenzymes of amylase, catalase and peroxidase in photo- and gibberellin-induced plants of Impatiens balsamina L. var. rose

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    Floral buds were induced either by 8 h photoperiods or by the application of GA3 and GA13 in Impatiens balsamina. Total enzyme activity was not directly related to floral morphogenesis although some interesting qualitative correlations existed. Thus, the presence of a new isoenzyme of amylase (RF 0·05) may be related to flower formation since it was present only in the induced plants and not in the vegetative ones, regardless of whether the flowering was caused by inductive photoperiods or by gibberellin treatment. Catalase activity, as well as its isoenzyme forms, could not be detected in the stem and the isoenzyme profile in leaves did not alter with photoperiodic or gibberellin treatment. Treatment with gibberellins induced the synthesis of new isoenzymes of peroxidase but inductive photoperiods did not. The enzyme profiles in relation to photoperiod and gibberellin application are discussed

    Aging display's effect on interpretation of digital pathology slides

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    It is our conjecture that the variability of colors in a pathology image effects the interpretation of pathology cases, whether it is diagnostic accuracy, diagnostic confidence, or workflow efficiency. In this paper, digital pathology images are analyzed to quantify the perceived difference in color that occurs due to display aging, in particular a change in the maximum luminance, white point, and color gamut. The digital pathology images studied include diagnostically important features, such as the conspicuity of nuclei. Three different display aging models are applied to images: aging of luminance & chrominance, aging of chrominance only, and a stabilized luminance & chrominance (i.e., no aging). These display models and images are then used to compare conspicuity of nuclei using CIE deltaE2000, a perceptual color difference metric. The effect of display aging using these display models and images is further analyzed through a human reader study designed to quantify the effects from a clinical perspective. Results from our reader study indicate significant impact of aged displays on workflow as well as diagnosis as follow. As compared to the originals (no-aging), slides with the effect of aging simulated were significantly more difficult to read (p-value of 0.0005) and took longer to score (p-value of 0.02). Moreover, luminance+chrominance aging significantly reduced inter-session percent agreement of diagnostic scores (p-value of 0.0418)

    Blimp-1-dependent and -independent natural antibody production by B-1 and B-1-derived plasma cells.

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    Natural antibodies contribute to tissue homeostasis and protect against infections. They are secreted constitutively without external antigenic stimulation. The differentiation state and regulatory pathways that enable continuous natural antibody production by B-1 cells, the main cellular source in mice, remain incompletely understood. Here we demonstrate that natural IgM-secreting B-1 cells in the spleen and bone marrow are heterogeneous, consisting of (a) terminally differentiated B-1-derived plasma cells expressing the transcriptional regulator of differentiation, Blimp-1, (b) Blimp-1+, and (c) Blimp-1neg phenotypic B-1 cells. Blimp-1neg IgM-secreting B-1 cells are not simply intermediates of cellular differentiation. Instead, they secrete similar amounts of IgM in wild-type and Blimp-1-deficient (PRDM-1ΔEx1A) mice. Blimp-1neg B-1 cells are also a major source of IgG3. Consequently, deletion of Blimp-1 changes neither serum IgG3 levels nor the amount of IgG3 secreted per cell. Thus, the pool of natural antibody-secreting B-1 cells is heterogeneous and contains a distinct subset of cells that do not use Blimp-1 for initiation or maximal antibody secretion

    Segmental anhidrosis with hyporeflexia associated with congenital spinal deformity: A Ross's syndrome variant or inverse Horner's syndrome?

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    A 39-year-old soldier presented with anhidrosis affecting both upper extremities below the shoulders, the right side of the trunk below the third rib in front and the third vertebra on the back, and the left lower extremity below the inguinal ligament since 1992. Ten years later in 2002, he was also found to have bilateral absence of Achilles reflex and decreased right knee jerk. In addition, the patient was found to have congenital spinal abnormalities in the form of block of vertebrae C3-C4; decreased disc space C4-C5; and break in pars interarticularis L5-S1 with decreased disc space. A total of seven cases of Ross syndrome, Holmes-Adie syndrome (tonic pupil with lost tendon jerks) with segmental anhidrosis, have been described in the literature. Our case, however, did not have any pupillary abnormality. A case of progressive isolated segmental anhidrosis has also been described. The association of congenital spinal abnormality, which may be pathognomonic in the causation of this progressive sudomotor degeneration, is quite interesting in our case. The distribution of anhidrosis on the right side is just below the level of sweating loss sometimes described in lesions of superior sympathetic cervical ganglion in Horner's syndrome

    A task and performance analysis of endoscopic submucosal dissection (ESD) surgery

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    BACKGROUND: ESD is an endoscopic technique for en bloc resection of gastrointestinal lesions. ESD is a widely-used in Japan and throughout Asia, but not as prevalent in Europe or the US. The procedure is technically challenging and has higher adverse events (bleeding, perforation) compared to endoscopic mucosal resection. Inadequate training platforms and lack of established training curricula have restricted its wide acceptance in the US. Thus, we aim to develop a Virtual Endoluminal Surgery Simulator (VESS) for objective ESD training and assessment. In this work, we performed task and performance analysis of ESD surgeries. METHODS: We performed a detailed colorectal ESD task analysis and identified the critical ESD steps for lesion identification, marking, injection, circumferential cutting, dissection, intraprocedural complication management, and post-procedure examination. We constructed a hierarchical task tree that elaborates the order of tasks in these steps. Furthermore, we developed quantitative ESD performance metrics. We measured task times and scores of 16 ESD surgeries performed by four different endoscopic surgeons. RESULTS: The average time of the marking, injection, and circumferential cutting phases are 203.4 (σ: 205.46), 83.5 (σ: 49.92), 908.4 s. (σ: 584.53), respectively. Cutting the submucosal layer takes most of the time of overall ESD procedure time with an average of 1394.7 s (σ: 908.43). We also performed correlation analysis (Pearson's test) among the performance scores of the tasks. There is a moderate positive correlation (R = 0.528, p = 0.0355) between marking scores and total scores, a strong positive correlation (R = 0.7879, p = 0.0003) between circumferential cutting and submucosal dissection and total scores. Similarly, we noted a strong positive correlation (R = 0.7095, p = 0.0021) between circumferential cutting and submucosal dissection and marking scores. CONCLUSIONS: We elaborated ESD tasks and developed quantitative performance metrics used in analysis of actual surgery performance. These ESD metrics will be used in future validation studies of our VESS simulator

    Biomarkers differentiate drug-induced liver injury from other liver injury: PONDER study

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    Background and Aim: Drug-induced liver injury (DILI) is a known complication of volatile anesthetic (VA) agents, and, despite being rare, DILI can be serious. One mechanism of VA-DILI occurs via interleukin 4 (IL-4)driven upregulation of cytochrome P450-2E1, leading to the formation of drug metabolites (haptens) that trigger IL-4-driven antigen-specific T cells and autoantibodies. Our group has developed biomarkers for liver injury and have examined this in patients before and after VA exposure. The aim of this prospective study was to determine the early markers of VA-DILI. Methods: We prospectively followed patients having a VA general anesthetic (sevoflurane and/or desflurane) and compared them with those who received regional or total intravenous anesthesia. Exclusion criteria were known liver disease or any episode of significant hypotension. Baseline data on patient demographics and comorbidities were collected, and blood was analyzed for liver biochemistry, macrophage activation markers (CD206, CD163), and IgG1 and IgG4 antibodies to JHDN5 (the CYP2E1 epitope) and trifluoroacetyl (TFA), the VA drug hapten. Follow-up blood samples were taken 48 h postoperatively and compared with baseline results. DILI was defined as an alanine aminotransferase (ALT) level greater than two times the upper limit of normal (ULN) and post-review agreement by an expert panel, taking into account the pattern of liver function test result derangement and intraoperative events. Results: Of 229 patients recruited, 16 developed an ALT level > 2 × ULN. Twelve were considered likely to have VA-DILI, including four with an ALT rise >3 × ULN. There was a trend to associate VA-DILI with obesity (RR, 2.98; P = 0.063); however, the association with dyslipidemia (RR, 1.47; P = 0.72), male sex (RR, 1.18; P = 0.76), history of atopy (RR, 1.16; P = 0.79), and heavy ethanol consumption (RR, 1.09; P = 0.89) was not statistically significant. Prior VA exposure was not a risk factor (RR, 0.89; P = 0.83). There was a rise in CD206 and decline in CD163 from baseline in all patients. However, in the patients with VA-DILI, the levels were significantly different from all other groups. TFA IgG1 and IgG4 antibodies were elevated in the VA-DILI group when compared with controls. Conclusion: Recognizing that our results may be skewed by our cohort, this work suggests the known immunological pathway mediated by IL-4 in response to an injury: rise in CD206 to stimulate an inflammatory response, and decrease in CD163 to modulate the response. The increase in TFA IgG1 and IgG4 antibodies in the VA-DILI group is consistent with metabolism and the heightened immune response in those who develop DILI. At this early juncture, JHDN5 IgG4 autoantibodies were not detected. Ongoing work is looking at other DILI, and how these markers can be used in DILI

    Impact of exciton delocalization on exciton-vibration interactions in organic semiconductors

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    Organic semiconductors exhibit properties of individual molecules and extended crystals simultaneously. The strongly bound excitons they host are typically described in the molecular limit, but excitons can delocalize over many molecules, raising the question of how important the extended crystalline nature is. Using accurate Green's function based methods for the electronic structure and non-perturbative finite difference methods for exciton-vibration coupling, we describe exciton interactions with molecular and crystal degrees of freedom concurrently. We find that the degree of exciton delocalization controls these interactions, with thermally activated crystal phonons predominantly coupling to delocalized states, and molecular quantum fluctuations predominantly coupling to localized states. Based on this picture, we quantitatively predict and interpret the temperature and pressure dependence of excitonic peaks in the acene series of organic semiconductors, which we confirm experimentally, and we develop a simple experimental protocol for probing exciton delocalization. Overall, we provide a unified picture of exciton delocalization and vibrational effects in organic semiconductors, reconciling the complementary views of finite molecular clusters and periodic molecular solids

    Multistrip synthetic single-crystal-diamond photodiode based on a p-type/intrinsic/Schottky metal transverse configuration

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    A synthetic multistrip single-crystal-diamond detector based on a p -type/intrinsic diamond/Schottky metal transverse configuration, operating at zero-bias voltage, was developed. The device was characterized at the Diamond Light Source synchrotron in Harwell (UK) under monochromatic high-flux X-ray beams from 6 to 20 keV and a micro-focused 10 keV beam with a spot size of ~3 μm . No significant pixel-to-pixel variation of both spectral responsivity and time response, high spatial resolution and good signal uniformity along each strip were found, suggesting the tested device structure as a promising sensor for X-ray and UV radiation imaging

    Initial experience of the High-Density Grid catheter in patients undergoing catheter ablation for atrial fibrillation

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    Purpose: A significant proportion of patients undergoing catheter ablation for atrial fibrillation (AF) experience arrhythmia recurrence. This is mostly due to pulmonary vein reconnection (PVR). Whether mapping using High-Density Wave (HDW) technology is superior to standard bipolar (SB) configuration at detecting PVR is unknown. We aimed to evaluate the efficacy of HDW technology compared to SB mapping in identifying PVR. / Methods: High-Density (HD) multipolar Grid catheters were used to create left atrial geometries and voltage maps in 36 patients undergoing catheter ablation for AF (either due to recurrence of an atrial arrhythmia from previous AF ablation or de novo AF ablation). Nineteen SB maps were also created and compared. Ablation was performed until pulmonary vein isolation was achieved. / Results: Median time of mapping with HDW was 22.3 [IQR: 8.2] min. The number of points collected with HDW (13299.6±1362.8 vs 6952.8±841.9, p<0.001) and used (2337.3±158.0 vs 1727.5±163.8, p<0.001) was significantly higher compared to SB. Moreover, HDW was able to identify more sleeves (16 for right and 8 for left veins), where these were confirmed electrically silent by SB, with significantly increased PVR sleeve size as identified by HDW (p<0.001 for both right and left veins). Importantly, with the use of HDW, the ablation strategy changed in 23 patients (64% of targeted veins) with a significantly increased number of lesions required as compared to SB for right (p=0.005) and left veins (p=0.003). / Conclusion: HDW technology is superior to SB in detecting pulmonary vein reconnections. This could potentially result into a significant change in ablation strategy and possibly to increased success rate following pulmonary vein isolation
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