4,067 research outputs found

    Compare HIV/syphilis infections between age groups and explore associated factors of HIV/ syphilis co-infections among men who have sex with men in Shenzhen, China, from 2009 to 2017

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    The aim of this study is to assess the HIV/syphilis epidemic among men who have sex with men (MSM) aged <50 years and ≥ 50 years in Shenzhen, and explore the associated factors of HIV/syphilis co-infections among MSM in Shenzhen, in order to help prevention and intervention programs determine their target sub-group. A serial cross-sectional study was conducted on MSM in Shenzhen city, China from 2009 to 2017. A questionnaire was used to collect demographic characteristics, history of HIV testing, history of blood donation and sexual behaviors. 5 ml of venous blood were collected for syphilis and HIV tests. The overall prevalence of HIV, syphilis, HIV/syphilis co-infection was 9.40%, 18.97%, and 4.91%, respectively. The prevalence of HIV (15.26%), syphilis (27.71%), HIV/syphilis co-infection (9.24%) in aged ≥ 50 years MSM was significantly higher than aged <50 years MSM (9.15%, 18.59% and 4.72%, respectively). The following factors were found to be significantly associated with HIV/syphilis co-infections (P<0.05): age≥50 years (OR = 1.78, 95% CI = 1.10–2.87), high school or lower (OR = 1.49, 95% CI = 1.10–2.01), monthly income ≤436.2 USD (OR = 1.74, 95% CI = 1.25–2.42), monthly income 436.4–727.2 USD (OR = 1.46, 95% CI = 1.05–2.03), ≥2 anal sex partners in the past 6 months (OR = 1.59, 95% CI = 1.02–2.49), ≥2 oral sex partners in the past 6 months (OR = 1.60, 95% CI = 1.08–2.36), inconsistent condom use during anal sex in the past 6 months (OR = 1.50, 95% CI = 1.11–2.03). We found that aged <50 years and ≥50 years MSM in Shenzhen had a high prevalence of HIV/syphilis infection in a period from 2009 to 2017. Age-specific sexually transmitted diseases education, prevention, and intervention programs for aged ≥50 years MSM should be implemented urgently and integrated interventions of both HIV and syphilis infections on MSM are needed in the future

    Geometric phase outside a Schwarzschild black hole and the Hawking effect

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    We study the Hawking effect in terms of the geometric phase acquired by a two-level atom as a result of coupling to vacuum fluctuations outside a Schwarzschild black hole in a gedanken experiment. We treat the atom in interaction with a bath of fluctuating quantized massless scalar fields as an open quantum system, whose dynamics is governed by a master equation obtained by tracing over the field degrees of freedom. The nonunitary effects of this system are examined by analyzing the geometric phase for the Boulware, Unruh and Hartle-Hawking vacua respectively. We find, for all the three cases, that the geometric phase of the atom turns out to be affected by the space-time curvature which backscatters the vacuum field modes. In both the Unruh and Hartle-Hawking vacua, the geometric phase exhibits similar behaviors as if there were thermal radiation at the Hawking temperature from the black hole. So, a measurement of the change of the geometric phase as opposed to that in a flat space-time can in principle reveal the existence of the Hawking radiation.Comment: 14 pages, no figures, a typo in the References corrected, version to appear in JHEP. arXiv admin note: text overlap with arXiv:1109.033

    Differences in the Activity of Endogenous Bone Morphogenetic Protein Signaling Impact on the Ability of Induced Pluripotent Stem Cells to Differentiate to Corneal Epithelial-Like Cells

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    Cornea is a clear outermost layer of the eye which enables transmission of light onto the retina. The transparent corneal epithelium is regenerated by limbal stem cells (LSCs), whose loss/dysfunction results in LSCs deficiency (LSCD). Ex vivo expansion of autologous LSCs obtained from patient's healthy eye followed by transplantation onto the LSCs damaged/deficient eye, has provided a successful treatment for unilateral LSCD. However, this is not applicable to patient with total bilateral LSCD, where LSCs are lost/damaged from both eyes. We investigated the potential of human induced pluripotent stem cell (hiPSC) to differentiate into corneal epithelial-like cells as a source of autologous stem cell treatment for patients with total bilateral LSCD. Our study showed that combined addition of bone morphogenetic protein 4 (BMP4), all trans-retinoic acid and epidermal growth factor for the first 9 days of differentiation followed by cell-replating on collagen-IV-coated surfaces with a corneal-specific-epithelial cell media for an additional 11 days, resulted in step wise differentiation of human embryonic stem cells (hESC) to corneal epithelial progenitors and mature corneal epithelial-like cells. We observed differences in the ability of hiPSC lines to undergo differentiation to corneal epithelial-like cells which were dependent on the level of endogenous BMP signaling and could be restored via the activation of this signaling pathway by a specific transforming growth factor β inhibitor (SB431542). Together our data reveal a differential ability of hiPSC lines to generate corneal epithelial cells which is underlined by the activity of endogenous BMP signaling pathway

    Ambient fabrication of flexible and large-area organic light-emitting devices using slot-die coating

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    The grand vision of manufacturing large-area emissive devices with low-cost roll-to-roll coating methods, akin to how newspapers are produced, appeared with the emergence of the organic light-emitting diode about 20 years ago. Today, small organic light-emitting diode displays are commercially available in smartphones, but the promise of a continuous ambient fabrication has unfortunately not materialized yet, as organic light-emitting diodes invariably depend on the use of one or more time- and energy-consuming process steps under vacuum. Here we report an all-solution-based fabrication of an alternative emissive device, a light-emitting electrochemical cell, using a slot-die roll-coating apparatus. The fabricated flexible sheets exhibit bidirectional and uniform light emission, and feature a fault-tolerant >1-μm-thick active material that is doped in situ during operation. It is notable that the initial preparation of inks, the subsequent coating of the constituent layers and the final device operation all could be executed under ambient air

    Deep Q-Network-Driven Catheter Segmentation in 3D US by Hybrid Constrained Semi-Supervised Learning and Dual-UNet

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    Catheter segmentation in 3D ultrasound is important for computer-assisted cardiac intervention. However, a large amount of labeled images are required to train a successful deep convolutional neural network (CNN) to segment the catheter, which is expensive and time-consuming. In this paper, we propose a novel catheter segmentation approach, which requests fewer annotations than the supervised learning method, but nevertheless achieves better performance. Our scheme considers a deep Q learning as the pre-localization step, which avoids voxel-level annotation and which can efficiently localize the target catheter. With the detected catheter, patch-based Dual-UNet is applied to segment the catheter in 3D volumetric data. To train the Dual-UNet with limited labeled images and leverage information of unlabeled images, we propose a novel semi-supervised scheme, which exploits unlabeled images based on hybrid constraints from predictions. Experiments show the proposed scheme achieves a higher performance than state-of-the-art semi-supervised methods, while it demonstrates that our method is able to learn from large-scale unlabeled images.Comment: Accepted by MICCAI 202

    Suboccipital craniotomy in the surgical treatment of Chiari I malformation

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    The object of this study was to present craniotomy for Chiari type I patients. Six patients with Chiari type I underwent suboccipital craniotomy. All patients showed clinical improvement, and none had any complications. Two patients had syringomyelia; it disappeared in entirety. We describe the procedure for posterior fossa decompression. Three-dimensional volumetric analysis using Vitrea workstation for postoperative posterior fossa volumes was calculated and was seen to have been increased on an average, from pre-operative (168 cc) to postoperative volume (192 cc). We thus conclude that suboccipital craniotomy results in resolution of the Chiari symptoms yet achieves effective expansion of posterior fossa

    Gene expression and splicing alterations analyzed by high throughput RNA sequencing of chronic lymphocytic leukemia specimens.

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    BackgroundTo determine differentially expressed and spliced RNA transcripts in chronic lymphocytic leukemia specimens a high throughput RNA-sequencing (HTS RNA-seq) analysis was performed.MethodsTen CLL specimens and five normal peripheral blood CD19+ B cells were analyzed by HTS RNA-seq. The library preparation was performed with Illumina TrueSeq RNA kit and analyzed by Illumina HiSeq 2000 sequencing system.ResultsAn average of 48.5 million reads for B cells, and 50.6 million reads for CLL specimens were obtained with 10396 and 10448 assembled transcripts for normal B cells and primary CLL specimens respectively. With the Cuffdiff analysis, 2091 differentially expressed genes (DEG) between B cells and CLL specimens based on FPKM (fragments per kilobase of transcript per million reads and false discovery rate, FDR q &lt; 0.05, fold change &gt;2) were identified. Expression of selected DEGs (n = 32) with up regulated and down regulated expression in CLL from RNA-seq data were also analyzed by qRT-PCR in a test cohort of CLL specimens. Even though there was a variation in fold expression of DEG genes between RNA-seq and qRT-PCR; more than 90 % of analyzed genes were validated by qRT-PCR analysis. Analysis of RNA-seq data for splicing alterations in CLL and B cells was performed by Multivariate Analysis of Transcript Splicing (MATS analysis). Skipped exon was the most frequent splicing alteration in CLL specimens with 128 significant events (P-value &lt;0.05, minimum inclusion level difference &gt;0.1).ConclusionThe RNA-seq analysis of CLL specimens identifies novel DEG and alternatively spliced genes that are potential prognostic markers and therapeutic targets. High level of validation by qRT-PCR for a number of DEG genes supports the accuracy of this analysis. Global comparison of transcriptomes of B cells, IGVH non-mutated CLL (U-CLL) and mutated CLL specimens (M-CLL) with multidimensional scaling analysis was able to segregate CLL and B cell transcriptomes but the M-CLL and U-CLL transcriptomes were indistinguishable. The analysis of HTS RNA-seq data to identify alternative splicing events and other genetic abnormalities specific to CLL is an added advantage of RNA-seq that is not feasible with other genome wide analysis

    Strange Attractors in Dissipative Nambu Mechanics : Classical and Quantum Aspects

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    We extend the framework of Nambu-Hamiltonian Mechanics to include dissipation in R3R^{3} phase space. We demonstrate that it accommodates the phase space dynamics of low dimensional dissipative systems such as the much studied Lorenz and R\"{o}ssler Strange attractors, as well as the more recent constructions of Chen and Leipnik-Newton. The rotational, volume preserving part of the flow preserves in time a family of two intersecting surfaces, the so called {\em Nambu Hamiltonians}. They foliate the entire phase space and are, in turn, deformed in time by Dissipation which represents their irrotational part of the flow. It is given by the gradient of a scalar function and is responsible for the emergence of the Strange Attractors. Based on our recent work on Quantum Nambu Mechanics, we provide an explicit quantization of the Lorenz attractor through the introduction of Non-commutative phase space coordinates as Hermitian N×N N \times N matrices in R3 R^{3}. They satisfy the commutation relations induced by one of the two Nambu Hamiltonians, the second one generating a unique time evolution. Dissipation is incorporated quantum mechanically in a self-consistent way having the correct classical limit without the introduction of external degrees of freedom. Due to its volume phase space contraction it violates the quantum commutation relations. We demonstrate that the Heisenberg-Nambu evolution equations for the Quantum Lorenz system give rise to an attracting ellipsoid in the 3N23 N^{2} dimensional phase space.Comment: 35 pages, 4 figures, LaTe

    Transesophageal echocardiography, more than a diagnostic tool: use during surgical ligation of coronary artery fistulae - a case report

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    Coronary artery fistulae (CAF) are an infrequent coronary abnormality. Herein, we describe the use of intraoperative transesophageal echocardiography (TEE) in the treatment of CAF. A 61 year-old woman presented with chest pain and symptoms consistent with unstable angina. Subsequent coronary angiography revealed the presence of 2 CAF, one extending from the left anterior descending artery to the pulmonary artery (PA) and the other extending from the proximal right coronary artery to the PA. Surgical ligation of the CAF without coronary bypass was arranged. Intraoperative TEE was successfully employed to localize the CAF, monitor fistula blood flow and heart wall motion, and confirm successful ligation. The patient recovered without complications. This case highlights the utility of intraoperative TEE during ligation of CAF
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