728 research outputs found

    Effective Rheology of Bubbles Moving in a Capillary Tube

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    We calculate the average volumetric flux versus pressure drop of bubbles moving in a single capillary tube with varying diameter, finding a square-root relation from mapping the flow equations onto that of a driven overdamped pendulum. The calculation is based on a derivation of the equation of motion of a bubble train from considering the capillary forces and the entropy production associated with the viscous flow. We also calculate the configurational probability of the positions of the bubbles.Comment: 4 pages, 1 figur

    Multicenter Prospective Study of Laparoscopic Nissen Fundoplication for Gastroesophageal Reflux Disease in Korea

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    BACKGROUND/AIMS: This multicenter study aims to evaluate the effect and feasibility of anti-reflux surgery compared with medical treatment for gastroesophageal reflux disease (GERD). METHODS: Patients with GERD who were undergoing medical treatment with proton pump inhibitors for more than 8 weeks and those who were scheduled to undergo anti-reflux surgery were enrolled. Efficacy of pre-operative medical treatment was evaluated retrospectively and effect of anti-reflux surgery was prospectively evaluated at 1 week and 3 months after surgery. Quality of life (QOL) was also investigated before and after surgery. RESULTS: Between February and October 2018, 51 patients underwent laparoscopic Nissen fundoplication for treating GERD at 5 hospitals in Korea. Thirty-four patients (66.7%) showed poor proton pump inhibitor response. At 3 months after surgery, heartburn was completely resolved in 87.9% patients and partially improved in 9.1%. Acid regurgitation was completely resolved in 82.9% and partially improved in 11.4%. Atypical extraesophageal symptoms were completely controlled in 45.5% and partially controlled in 36.4%. GERD-related QOL scores at 1 week after surgery significantly improved compared with pre-operative scores. There was no difference in GERD-related QOL scores between 1 week and 3 months after surgery. General QOL measured with European QOL-5 dimensions and health-related QOL instrument with 8 items significantly improved after anti-reflux surgery. Satisfaction with treatment was significantly higher after surgery than before surgery (72.5% vs 11.8%, P < 0.001). CONCLUSION: Anti-reflux surgery improved GERD symptoms and QOL in patients. Anti-reflux surgery is an effective treatment option compared with medical treatment for GERD patients selected for surgical treatment

    Relationship of circulating hyaluronic Acid levels to disease control in asthma and asthmatic pregnancy.

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    Uncontrolled asthma is a risk factor for pregnancy-related complications. Hyaluronic acid (HA), a potential peripheral blood marker of tissue fibrosis in various diseases, promotes eosinophil survival and plays a role in asthmatic airway inflammation as well as in physiological processes necessary to maintain normal pregnancy; however the level of circulating HA in asthma and asthmatic pregnancy is unknown. We investigated HA levels in asthmatic patients (N = 52; asthmatic pregnant (AP) N = 16; asthmatic non-pregnant (ANP) N = 36) and tested their relationship to asthma control. Serum HA level was lower in AP than in ANP patients (27 [24.7-31.55] vs. 37.4 [30.1-66.55] ng/mL, p = 0.006); the difference attenuated to a trend after its adjustment for patients' age (p = 0.056). HA levels and airway resistance were positively (r = 0.467, p = 0.004), HA levels and Asthma Control Test (ACT) total score inversely (r = -0.437, p = 0.01) associated in ANP patients; these relationships remained significant even after their adjustments for age. The potential value of HA in the determination of asthma control was analyzed using ROC analysis which revealed that HA values discriminate patients with ACT total score >/=20 (controlled patients) and <20 (uncontrolled patients) with a 0.826 efficacy (AUC, 95% CI: 0.69-0.97, p = 0.001) when 37.4 ng/mL is used as cut-off value in ANP group, and with 0.78 efficacy (AUC, 95% CI: 0.65-0.92, p = 0.0009) in the whole asthmatic cohort. In conclusion circulating HA might be a marker of asthma control, as it correlates with airway resistance and has good sensitivity in the detection of impaired asthma control. Decrease of HA level in pregnancy may be the consequence of pregnancy induced immune tolerance

    Community assessment to advance computational prediction of cancer drug combinations in a pharmacogenomic screen

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    The effectiveness of most cancer targeted therapies is short-lived. Tumors often develop resistance that might be overcome with drug combinations. However, the number of possible combinations is vast, necessitating data-driven approaches to find optimal patient-specific treatments. Here we report AstraZeneca's large drug combination dataset, consisting of 11,576 experiments from 910 combinations across 85 molecularly characterized cancer cell lines, and results of a DREAM Challenge to evaluate computational strategies for predicting synergistic drug pairs and biomarkers. 160 teams participated to provide a comprehensive methodological development and benchmarking. Winning methods incorporate prior knowledge of drug-target interactions. Synergy is predicted with an accuracy matching biological replicates for >60% of combinations. However, 20% of drug combinations are poorly predicted by all methods. Genomic rationale for synergy predictions are identified, including ADAM17 inhibitor antagonism when combined with PIK3CB/D inhibition contrasting to synergy when combined with other PI3K-pathway inhibitors in PIK3CA mutant cells

    Association analysis of polymorphism in KIAA1717, HUMMLC2B, DECR1 and FTO genes with meat quality traits of the Berkshire breed

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    Single nucleotide polymorphisms (SNPs) in KIAA1717, HUMMLC2B, DECR1, and FTO genes have been found to be associated with some pork meat quality traits. In this study, we discovered that, in addition to meat quality traits reported previously, SNPs in these genes also are significantly associated with other meat quality traits in the Berkshire breed. A total of 323 Berkshire pigs bred under the same conditions were used for meat quality evaluation and polymerase chain reaction-amplified genes with restriction endonucleases (PCR-RFLP) genotyping analyses. The association analysis of RFLP genotyping with meat quality traits revealed that the SNPs in these 4 genes have novel associations with multiple meat quality traits (p &lt; 0.01 or p &lt; 0.05); a SNP in KIAA1717 was associated with meat color (CIE L), backfat thickness, drip loss, water-holding capacity, and pH24hr; a SNP in HUMMLC2B was associated with chemical composition (collagen), drip loss, shear force, and pH24hr; a SNP in DECR1 was associated with meat color (CIE a and b) and backfat thickness; and a SNP in FTO was associated with meat color (CIE L, a and b), protein content, drip loss, and water-holding capacity. Taken collectively, our results suggest that these 4 SNPs may be used for marker-assisted selection as a genetic marker for meat quality traits in Berkshire pigs.Key words: Berkshire, genetic markers, meat quality, SN

    Subgrouping of Peripheral Neuropathic Pain Patients According to Sensory Symptom Profile using the Korean Version of the PainDETECT Questionnaire

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    BACKGROUND: A culturally validated Korean version of the PainDETECT Questionnaire (PD-Q) was used to identify neuropathic pain components (NeP) in patients suffering from chronic pain. The purpose of this study was to determine if the Korean PD-Q can be used to subgroup patients with peripheral NeP according to sensory symptom profiles. METHODS: This study included 400 Korean patients with peripheral neuropathic pain diagnosed as probable or definite NeP. The total scores and subscores for each item in PD-Q were transformed into a Z-score for standardization. Hierarchical cluster analysis was performed to identify clusters of subjects by PD-Q scores. RESULTS: The mean total PD-Q score of the study participants was 14.57 +/- 6.46. A hierarchical cluster analysis identified 5 clusters with distinct pain characteristic profiles. Cluster 1 had relatively severe burning and tingling sensations. The mean total PD-Q score for cluster 2 was the lowest of the 5 clusters. Cluster 3 tended to be vulnerable to pain in response to cold/heat stimulation. Cluster 4 showed relatively severe pain induced by physical stimuli, such as light touch or slight pressure. Cluster 5 had high scores for all NeP symptoms. CONCLUSION: This study demonstrates the ability of patients to cluster by symptoms using the Korean PD-Q. Subgrouping of peripheral neuropathic pain by sensory symptom profile may be useful in making effective drug treatment decisions

    Multi-messenger observations of a binary neutron star merger

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    On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta

    A comparative study on the marginal fit of zirconia cores manufactured by CAD/CAM and copy milling methods

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    Purpose: The marginal fit of zirconia cores that were produced by CAD/CAM and by copy milling systems was compared and analyzed to confirm the significance of the variation in dental technicians skill between the two systems.Materials and Methods: Using dental resin teeth and individual trays, 30 plaster casts were produced. Fifteen casts were assigned to be used with five different zirconia core manufacturing dental laboratories using the same CAD/CAM system, which were designated as the CC group. The remaining 15 were assigned to be used with five different zirconia core manufacturing dental laboratories using also the same copy milling system and were designated as the CM group. The zirconia cores were fabricated and were cemented onto the casts. The vertical marginal opening was measured under an optical microscope at 75x magnification. The measured vertical marginal discrepancies were analyzed using an independent sample t-test, and the significance of the vertical marginal gap value for each dental laboratory was analyzed by performing the Kruskal-Wallis test.Results: The means and standard deviations for the marginal discrepancies of the CC and CM groups were found to be 102.73 ± 29.73 μm and 82.25 ± 22.37 μm, respectively. The independent sample t-test showed a significant difference between the two systems; the CAD/CAM system showed a larger vertical marginal gap than the copy milling system. The Kruskal-Wallis test indicated that no significant distributional differences were found between the dental laboratories in either the CAD/CAM or the copy milling systems.Conclusions: The copy milling system may produce more accurate zirconia restorations than the CAD/CAM system. The technicians skill of a copy milling system may not be a determining factor influencing the accuracy of a single zirconia core.Purpose: The marginal fit of zirconia cores that were produced by CAD/CAM and by copy milling systems was compared and analyzed to confirm the significance of the variation in dental technicians skill between the two systems. Materials and Methods: Using dental resin teeth and individual trays, 30 plaster casts were produced. Fifteen casts were assigned to be used with five different zirconia core manufacturing dental laboratories using the same CAD/CAM system, which were designated as the CC group. The remaining 15 were assigned to be used with five different zirconia core manufacturing dental laboratories using also the same copy milling system and were designated as the CM group. The zirconia cores were fabricated and were cemented onto the casts. The vertical marginal opening was measured under an optical microscope at 75x magnification. The measured vertical marginal discrepancies were analyzed using an independent sample t-test, and the significance of the vertical marginal gap value for each dental laboratory was analyzed by performing the Kruskal-Wallis test. Results: The means and standard deviations for the marginal discrepancies of the CC and CM groups were found to be 102.73 ± 29.73 µm and 82.25 ± 22.37 µm, respectively. The independent sample t-test showed a significant difference between the two systems; the CAD/CAM system showed a larger vertical marginal gap than the copy milling system. The Kruskal-Wallis test indicated that no significant distributional differences were found between the dental laboratories in either the CAD/CAM or the copy milling systems. Conclusions: The copy milling system may produce more accurate zirconia restorations than the CAD/CAM system. The technicians skill of a copy milling system may not be a determining factor influencing the accuracy of a single zirconia core.OAIID:oai:osos.snu.ac.kr:snu2013-01/102/2008003883/14SEQ:14PERF_CD:SNU2013-01EVAL_ITEM_CD:102USER_ID:2008003883ADJUST_YN:NEMP_ID:A078517DEPT_CD:861CITE_RATE:0FILENAME:dentistry 201311 3 163.pdfDEPT_NM:치의학과EMAIL:[email protected]_YN:NCONFIRM:

    A functional variant in the Stearoyl-CoA desaturase gene promoter enhances fatty acid desaturation in pork

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    There is growing public concern about reducing saturated fat intake. Stearoyl-CoA desaturase (SCD) is the lipogenic enzyme responsible for the biosynthesis of oleic acid (18:1) by desaturating stearic acid (18:0). Here we describe a total of 18 mutations in the promoter and 3′ non-coding region of the pig SCD gene and provide evidence that allele T at AY487830:g.2228T>C in the promoter region enhances fat desaturation (the ratio 18:1/18:0 in muscle increases from 3.78 to 4.43 in opposite homozygotes) without affecting fat content (18:0+18:1, intramuscular fat content, and backfat thickness). No mutations that could affect the functionality of the protein were found in the coding region. First, we proved in a purebred Duroc line that the C-T-A haplotype of the 3 single nucleotide polymorphisms (SNPs) (g.2108C>T; g.2228T>C; g.2281A>G) of the promoter region was additively associated to enhanced 18:1/18:0 both in muscle and subcutaneous fat, but not in liver. We show that this association was consistent over a 10-year period of overlapping generations and, in line with these results, that the C-T-A haplotype displayed greater SCD mRNA expression in muscle. The effect of this haplotype was validated both internally, by comparing opposite homozygote siblings, and externally, by using experimental Duroc-based crossbreds. Second, the g.2281A>G and the g.2108C>T SNPs were excluded as causative mutations using new and previously published data, restricting the causality to g.2228T>C SNP, the last source of genetic variation within the haplotype. This mutation is positioned in the core sequence of several putative transcription factor binding sites, so that there are several plausible mechanisms by which allele T enhances 18:1/18:0 and, consequently, the proportion of monounsaturated to saturated fat.This research was supported by grants from the Spanish Ministry of Science and Innovation (AGL2009-09779 and AGL2012-33529). RRF is recipient of a PhD scholarship from the Spanish Ministry of Science and Innovation (BES-2010-034607). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of manuscript

    On the dynamics of the adenylate energy system: homeorhesis vs homeostasis.

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    Biochemical energy is the fundamental element that maintains both the adequate turnover of the biomolecular structures and the functional metabolic viability of unicellular organisms. The levels of ATP, ADP and AMP reflect roughly the energetic status of the cell, and a precise ratio relating them was proposed by Atkinson as the adenylate energy charge (AEC). Under growth-phase conditions, cells maintain the AEC within narrow physiological values, despite extremely large fluctuations in the adenine nucleotides concentration. Intensive experimental studies have shown that these AEC values are preserved in a wide variety of organisms, both eukaryotes and prokaryotes. Here, to understand some of the functional elements involved in the cellular energy status, we present a computational model conformed by some key essential parts of the adenylate energy system. Specifically, we have considered (I) the main synthesis process of ATP from ADP, (II) the main catalyzed phosphotransfer reaction for interconversion of ATP, ADP and AMP, (III) the enzymatic hydrolysis of ATP yielding ADP, and (IV) the enzymatic hydrolysis of ATP providing AMP. This leads to a dynamic metabolic model (with the form of a delayed differential system) in which the enzymatic rate equations and all the physiological kinetic parameters have been explicitly considered and experimentally tested in vitro. Our central hypothesis is that cells are characterized by changing energy dynamics (homeorhesis). The results show that the AEC presents stable transitions between steady states and periodic oscillations and, in agreement with experimental data these oscillations range within the narrow AEC window. Furthermore, the model shows sustained oscillations in the Gibbs free energy and in the total nucleotide pool. The present study provides a step forward towards the understanding of the fundamental principles and quantitative laws governing the adenylate energy system, which is a fundamental element for unveiling the dynamics of cellular life
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