739 research outputs found
Hydrodynamical Simulations of the Barred Spiral Galaxy NGC 1097
NGC 1097 is a nearby barred spiral galaxy believed to be interacting with the
elliptical galaxy NGC 1097A located to its northwest. It hosts a Seyfert 1
nucleus surrounded by a circumnuclear starburst ring. Two straight dust lanes
connected to the ring extend almost continuously out to the bar. The other ends
of the dust lanes attach to two main spiral arms. To provide a physical
understanding of its structural and kinematical properties, two-dimensional
hydrodynamical simulations have been carried out. Numerical calculations reveal
that many features of the gas morphology and kinematics can be reproduced
provided that the gas flow is governed by a gravitational potential associated
with a slowly rotating strong bar. By including the self-gravity of the gas
disk in our calculation, we have found the starburst ring to be gravitationally
unstable which is consistent with the observation in \citet{hsieh11}. Our
simulations show that the gas inflow rate is 0.17 M_\sun yr into the
region within the starburst ring even after its formation, leading to the
coexistence of both a nuclear ring and a circumnuclear disk.Comment: 32 pages, 14 figures, 1 table, accepted for publication in the Ap
Clinical and pathological correlates of severity classifications in trigger fingers based on computer-aided image analysis
BACKGROUND: The treatment of trigger finger so far has heavily relied on clinicians’ evaluations for the severity of patients’ symptoms and the functionality of affected fingers. However, there is still a lack of pathological evidence supporting the criteria of clinical evaluations. This study’s aim was to correlate clinical classification and pathological changes for trigger finger based on the tissue abnormality observed from microscopic images. METHODS: Tissue samples were acquired, and microscopic images were randomly selected and then graded by three pathologists and two physicians, respectively. Moreover, the acquired images were automatically analyzed to derive two quantitative parameters, the size ratio of the abnormal tissue region and the number ratio of the abnormal nuclei, which can reflect tissue abnormality caused by trigger finger. A self-developed image analysis system was used to avoid human subjectivity during the quantification process. Finally, correlations between the quantitative image parameters, pathological grading, and clinical severity classification were assessed. RESULTS: One-way ANOVA tests revealed significant correlations between the image quantification and pathological grading as well as between the image quantification and clinical severity classification. The Cohen’s kappa coefficient test also depicted good consistency between pathological grading and clinical severity classification. CONCLUSIONS: The criteria of clinical classification were found to be highly associated with the pathological changes of affected tissues. The correlations serve as explicit evidence supporting clinicians in making a treatment strategy of trigger finger. In addition, our proposed computer-aided image analysis system was considered to be a promising and objective approach to determining trigger finger severity at the microscopic level
Effects of support groups on the primary family caregivers
Objective: The purpose of this study was to investigate the effect of a support group for primary family caregivers of elderly with dementia on both the caregiver\u27s burden and the quality of life.
Methods: A 2-group quasi-experimental study, using a pre-and post-test repeated measure method, was conducted to investigate the study outcomes. Recruited through from a medical center in central Taiwan, 72 primary family caregivers were assigned to the control (n = 38) and the experimental groups (n = 34), based on participants\u27 choices. The experimental group participated at the support group that comprised of five sessions; each session lasted for three hours, two hours of education on the disease process and care strategies and one hour of discussion, question and answer. The support group met every two weeks. The control group received a health teaching pamphlet on dementia at their medical visit. Data from both group were collected, at the same time, three times: first at baseline, the second time at upon immediate completion of the support group and the third time at one month after the second data collection. A demographic questionnaire developed by the researcher, the Chinese version of Caregiver Burden Inventory by developed Novak & Guest (1989) and translated by Cho (2002) and Taiwan version of WHOQOL-BREF, translated by Yao (2001) were used to collect data. Descriptive statistics, chi-square, t-test, paired t-test, ANOVA, Pearson correlation, and repeated measurements ANOVA were used to answer the research questions and to test study hypotheses. The significant level was set at 0.05. Data were analyzed using SPSS 12.0 software.
Results: The results of this study were as follow: (a) the participating caregivers showed a moderate degree of caregiver\u27s burden (total score = 1234) with mean scores of 48.71 (SD = 13.74) and 45.68 (SD = 11.70) for the experimental and the control groups, respectively; (b) moderate levels of quality of life (total score = 1234) were found with either the experimental group (M = 51.81; SD = 8.67) or the control group (M = 49.68; SD = 9.43); (c) every one point increased in caregiver s burden, there would be a decrease of 0.65 in caregiver s burden (p = .036); the caregiver\u27s burden would explain 31.5% variance of caregiver\u27s quality of life (p = .000); (d) length of time as a caregiver was related to the level of caregiver s burden; every one month increase in length of time, there would be an increase of 0.045 in caregiver s burden (p = .036); (e) the support group intervention had a positive impact on the caregiver s burden and the quality of life; (f) participants at the experimental group had better caregivers burdens and better qualities of lives than those in control group did at immediate completion of the support group and at 1-month follow up.
Conclusions and Implication: Results of this study may serve as a reference for healthcare professionals when planning care for elderly with dementia and their families. A support group should be considered as a routine care regimen to provide holistic care and to improve the overall well-beings of family caregivers
N-terminal functional domain of Gasdermin A3 regulates mitochondrial homeostasis via mitochondrial targeting
BACKGROUND: The epidermis forms a critical barrier that is maintained by orchestrated programs of proliferation, differentiation, and cell death. Gene mutations that disturb this turnover process may cause skin diseases. Human GASDERMIN A (GSDMA) is frequently silenced in gastric cancer cell lines and its overexpression has been reported to induce apoptosis. GSDMA has also been linked with airway hyperresponsiveness in genetic association studies. The function of GSDMA in the skin was deduced by dominant mutations in mouse gasdermin A3 (Gsdma3), which caused skin inflammation and hair loss. However, the mechanism for the autosomal dominance of Gsdma3 mutations and the mode of Gsdma3’s action remain unanswered. RESULTS: We demonstrated a novel function of Gsdma3 in modulating mitochondrial oxidative stress. We showed that Gsdma3 is regulated by intramolecular fold-back inhibition, which is disrupted by dominant mutations in the C-terminal domain. The unmasked N-terminal domain of Gsdma3 associates with Hsp90 and is delivered to mitochondrial via mitochondrial importer receptor Tom70, where it interacts with the mitochondrial chaperone Trap1 and causes increased production of mitochondrial reactive oxygen species (ROS), dissipation of mitochondrial membrane potential, and mitochondrial permeability transition (MPT). Overexpression of the C-terminal domain of Gsdma3 as well as pharmacological interventions of mitochondrial translocation, ROS production, and MPT pore opening alleviate the cell death induced by Gsdma3 mutants. CONCLUSIONS: Our results indicate that the genetic mutations in the C-terminal domain of Gsdma3 are gain-of-function mutations which unmask the N-terminal functional domain of Gsdma3. Gsdma3 regulates mitochondrial oxidative stress through mitochondrial targeting. Since mitochondrial ROS has been shown to promote epidermal differentiation, we hypothesize that Gsdma3 regulates context-dependent response of keratinocytes to differentiation and cell death signals by impinging on mitochondria. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12929-015-0152-0) contains supplementary material, which is available to authorized users
Anti-Hyperglycemic Properties of Crude Extract and Triterpenes from Poria cocos
Poria cocos, Bai Fu Ling in Chinese, is used in traditional Chinese medicine to treat diabetes. However, its claimed benefits and mechanism are not fully understood. This study aimed to investigate the effect and action of P. cocos on type 2 diabetes. We first performed phytochemical analysis on the crude extract and factions of P. cocos. P. cocos crude extract at 50 mg/kg body weight or more significantly decreased blood glucose levels in db/db mice. Based on a bioactivity-directed fractionation and isolation (BDFI) strategy, chloroform fraction and subfractions 4 and 6 of the P. cocos crude extract possessed a blood glucose-lowering effect. Dehydrotumulosic acid, dehydrotrametenolic acid, and pachymic acid were identified from the chloroform sub-fractions 4, 3, and 2, respectively. Dehydrotumulosic acid had anti-hyperglycemic effect to a greater extent than dehydrotrametenolic acid and pachymic acid. Mechanistic study on streptozocin- (STZ-) treated mice showed that the crude extract, dehydrotumulosic acid, dehydrotrametenolic acid, and pachymic acid of P. cocos exhibited different levels of insulin sensitizer activity. However, the P. cocos crude extract and triterpenes appeared not to activate PPAR-γ pathway. Overall, the data suggest that the P. cocos extract and its triterpenes reduce postprandial blood glucose levels in db/db mice via enhanced insulin sensitivity irrespective of PPAR-γ
MidiBERT-Piano: Large-scale Pre-training for Symbolic Music Understanding
This paper presents an attempt to employ the mask language modeling approach
of BERT to pre-train a 12-layer Transformer model over 4,166 pieces of
polyphonic piano MIDI files for tackling a number of symbolic-domain
discriminative music understanding tasks. These include two note-level
classification tasks, i.e., melody extraction and velocity prediction, as well
as two sequence-level classification tasks, i.e., composer classification and
emotion classification. We find that, given a pre-trained Transformer, our
models outperform recurrent neural network based baselines with less than 10
epochs of fine-tuning. Ablation studies show that the pre-training remains
effective even if none of the MIDI data of the downstream tasks are seen at the
pre-training stage, and that freezing the self-attention layers of the
Transformer at the fine-tuning stage slightly degrades performance. All the
five datasets employed in this work are publicly available, as well as
checkpoints of our pre-trained and fine-tuned models. As such, our research can
be taken as a benchmark for symbolic-domain music understanding
High-performance and long-term stability of mesoporous Cu-doped TiO2 microsphere for catalytic CO oxidation
Although the low-temperature reaction mechanism of catalytic CO oxidation reaction remains unclear, the active sites of copper play a crucial role in this mechanism. One-step aerosol-assisted self-assembly (AASA) process has been developed for the synthesis of mesoporous Cu-doped TiO2 microspheres (CuTMS) to incorporate copper into the TiO2 lattice. This strategy highly enhanced the dispersion of copper from 41.10 to 83.65%. Long-term stability of the as-synthesized CuTMS materials for catalytic CO oxidation reaction was monitored using real-time mass spectrum. Isolated CuO and Cu-O-Ti were formed as determined by X-ray photoelectron spectroscopy (XPS). The formation of the Cu-O-Ti bonds in the crystal lattice changes the electron densities of Ti(IV) and O, causing a subsequent change in Ti(III)/Ti(IV) and Onon/OTotal ratio. 20CuTMS contained the highest lattice distortion (0.44) in which the Onon/OTotal ratio is lowest (0.18). This finding may be attributed to the absolute formation of the Cu-O-Ti bonds in the crystal lattice. However, the decrease of Ti(III)/Ti(IV) ratio to about 0.35 of 25CuTMS was caused by the CuO cluster formation on the surface. N2O titration-assisted H2 temperature-programmed reduction and in-situ Fourier transform infrared spectroscopy revealed the properties of copper and effects of active sites
Fidelity approach to Gaussian transitions
The fidelity approach to the Gaussian transitions in spin-one XXZ spin chains
with three different values of Ising-like anisotropy lambda is analyzed by
means of the density matrix renormalization group (DMRG) technique for systems
of large sizes. We find that, despite the success in the cases of lambda=2.59
and 1, the fidelity susceptibility fails to detect the Gaussian transition for
lambda=0.5. Thus our results demonstrate the limitation of the fidelity
susceptibility in characterizing quantum phase transitions, which was proposed
recently in general frameworks.Comment: 9 pages, 9 figure
Site-specific His/Asp phosphoproteomic analysis of prokaryotes reveals putative targets for drug resistance
Abstract Background Phosphorylation of amino acid residues on proteins is an important and common post-translational modification in both eukaryotes and prokaryotes. Most research work has been focused on phosphorylation of serine, threonine or tyrosine residues, whereas phosphorylation of other amino acids are significantly less clear due to the controversy on their stability under standard bioanalytical conditions. Results Here we applied a shotgun strategy to analyze the histidine and aspartate phosphorylations in different microbes. Our results collectively indicate that histidine and aspartate phosphorylations frequently occur also in proteins that are not part of the two-component systems. Noticeably, a number of the modified proteins are pathogenesis-related or essential for survival in host. These include the zinc ion periplasmic transporter ZnuA in Acinetobacter baumannii SK17, the multidrug and toxic compound extrusion (MATE) channel YeeO in Klebsiella pneumoniae NTUH-K2044, branched amino acid transporter AzlC in Vibrio vulnificus and the RNA-modifying pseudouridine synthase in Helicobacter pylori. Conclusions In summary, histidine and aspartate phosphorylation is likely to be ubiquitous and to take place in proteins of various functions. This work also sheds light into how these functionally important proteins and potential drug targets might be regulated at a post-translational level
- …
