1,012 research outputs found
Branchial cleft cyst arising in posterior mediastinum: A case report
Branchial cleft cysts are congenital diseases of the neck caused by abnormal embryonic development of the first to fourth branchial clefts. Most branchial cleft cysts are found in the head and neck, but branchial cleft cysts arising in posterior mediastinum are rarely reported. We report a 44-year-old Chinese man who was found to have a right-posterior mediastinal mass on chest computed tomography (CT) during a physical examination. The size of the mass was about 30.6 mm * 25.1 mm and enhanced CT of the chest showed an occupying lesion in the right parietal esophagus of the upper-posterior mediastinum with no significant enhancement. The patient was considered to have a neurogenic tumor with cystic change and underwent posterior mediastinal tumor resection. Postoperatively, pathological examination confirmed the final diagnosis of bronchial cleft cyst. The patient was discharged on the 7th day after surgery. One year postsurgery, no obvious recurrence was found in reexamination
Collaborative filtering with diffusion-based similarity on tripartite graphs
Collaborative tags are playing more and more important role for the
organization of information systems. In this paper, we study a personalized
recommendation model making use of the ternary relations among users, objects
and tags. We propose a measure of user similarity based on his preference and
tagging information. Two kinds of similarities between users are calculated by
using a diffusion-based process, which are then integrated for recommendation.
We test the proposed method in a standard collaborative filtering framework
with three metrics: ranking score, Recall and Precision, and demonstrate that
it performs better than the commonly used cosine similarity.Comment: 8 pages, 4 figures, 1 tabl
Study on the spatial distribution pattern of Cx40 gap junctions in the atria of patients with coronary heart disease
Background: The aim of this study was to evaluate the association between atrial fibrillation
and atrial dilation and the spatial distribution pattern of connexin 40 in the atria of patients
with coronary heart disease.
Methods: Twenty-six patients with coronary heart disease undergoing cardiac surgery for
coronary artery bypass graft were investigated and were divided into three groups according to
the left atrial size and rhythm, atrial fibrillation and left atrial dilatation (AF+AD), sinus
rhythm and left atrial dilation (SR+AD) and sinus rhythm as control group SR. The spatial
distribution patterns of Cx40 were evaluated using confocal laser scanning microscopy assay.
Results: No significant differences were observed in the size and density of Cx40 gap junction
in the right atrium among all three groups (p > 0.05). Compared with the control group, the size
of Cx40 disk area in termination links and in lateral abutment in left atrium was markedly
larger in AF+AD group and SR+AD group than those of the controls (p < 0.01). A comparison
of size and density of Cx40 gap junction in the left atrium in the AF+AD group and SR+AD
group did not show significant differences.
Conclusions: The present study has shown altered gap junction distribution in coronary
heart disease resulting from atrial dilation and atrial fibrillation. A decrease in the size and density
of Cx40 gap junction was observed in patients with atrial dilation, which could be an important
factor in the initiation and maintenance of atrial fibrillation. (Cardiol J 2008; 15: 50-56
Sudakov effects in BBNS approach
The end-point singularity is an unsolved problem in BBNS approach.
Incorporating the partonic transverse momentum and the Sudakov form factor,
this problem can be solved model-independently. We discuss the Sudakov effects
in BBNS approach. The BBNS approach is compared with the modified PQCD
approach. The main idea of Sudakov form factor is briefly discussed. Our
conclusion is that the twist-3 contribution for the hard spectator scattering
is numerically not important in decays, compared with the twist-2
contribution.Comment: 16 pages, Latex, two figures, some typos correcte
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Publisher Correction: Copper adparticle enabled selective electrosynthesis of n-propanol.
An amendment to this paper has been published and can be accessed via a link at the top of the paper
Collaborative filtering based on multi-channel diffusion
In this paper, by applying a diffusion process, we propose a new index to
quantify the similarity between two users in a user-object bipartite graph. To
deal with the discrete ratings on objects, we use a multi-channel
representation where each object is mapped to several channels with the number
of channels being equal to the number of different ratings. Each channel
represents a certain rating and a user having voted an object will be connected
to the channel corresponding to the rating. Diffusion process taking place on
such a user-channel bipartite graph gives a new similarity measure of user
pairs, which is further demonstrated to be more accurate than the classical
Pearson correlation coefficient under the standard collaborative filtering
framework.Comment: 9 pages, 3 figure
Empirical analysis of web-based user-object bipartite networks
Understanding the structure and evolution of web-based user-object networks
is a significant task since they play a crucial role in e-commerce nowadays.
This Letter reports the empirical analysis on two large-scale web sites,
audioscrobbler.com and del.icio.us, where users are connected with music groups
and bookmarks, respectively. The degree distributions and degree-degree
correlations for both users and objects are reported. We propose a new index,
named collaborative clustering coefficient, to quantify the clustering behavior
based on the collaborative selection. Accordingly, the clustering properties
and clustering-degree correlations are investigated. We report some novel
phenomena well characterizing the selection mechanism of web users and outline
the relevance of these phenomena to the information recommendation problem.Comment: 6 pages, 7 figures and 1 tabl
Ruptured appendiceal cystadenoma presenting as right inguinal hernia in a patient with left colon cancer: A case report and review of literature
BACKGROUND: Mucoceles resulting from cystadenomas of the appendix are uncommon. Although rare, rupture of the mucoceles can occur with or without causing any abdominal complaint. There are several reports associating colonic malignancy with cystadenomas of the appendix. Herein, we report an unusual and interesting case of right inguinal hernia associated with left colon cancer. CASE PRESENTATION: A case of ruptured mucocele resulting from cystadenoma of the appendix was presented as right inguinal hernia in a 70-year-old male. The patient underwent colonoscopy, x-ray, ultrasound and computed tomography. Localized pseudomyxoma peritonei associated with adenocarcinoma of the descending colon was diagnosed. The patient underwent segmental resection of the colon, appendectomy, debridement of pseudomyxoma and closure of the internal ring of right inguinal canal. He is free of symptoms in one year follow-up. CONCLUSION: Synchronous colon cancer may occur in patients with appendiceal mucoceles. In such patients, the colon should be investigated and colonoscopy can be performed meticulously in cases of ruptured mucoceles and localized pseudomyxoma peritonei. Surgical intervention is the current choice of management
A molten globule-to-ordered structure transition of Drosophila melanogaster crammer is required for its ability to inhibit cathepsin
Drosophila melanogaster crammer is a novel cathepsin inhibitor that is involved in LTM (long-term memory) formation. The mechanism by which the inhibitory activity is regulated remains unclear. In the present paper we have shown that the oligomeric state of crammer is pH dependent. At neutral pH, crammer is predominantly dimeric in vitro as a result of disulfide bond formation, and is monomeric at acidic pH. Our inhibition assay shows that monomeric crammer, not disulfide-bonded dimer, is a strong competitive inhibitor of cathepsin L. Crammer is a monomeric molten globule in acidic solution, a condition that is similar to the environment in the lysosome where crammer is probably located. Upon binding to cathepsin L, however, crammer undergoes a molten globule-to-ordered structural transition. Using high-resolution NMR spectroscopy, we have shown that a cysteine-to-serine point mutation at position 72 (C72S) renders crammer monomeric at pH 6.0 and that the structure of the C72S variant highly resembles that of wild-type crammer in complex with cathepsin L at pH 4.0. We have determined the first solution structure of propeptide-like protease inhibitor in its active form and examined in detail using a variety of spectroscopic methods the folding properties of crammer in order to delineate its biomolecular recognition of cathepsin
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