428 research outputs found

    Ferromagnetic effect and spin assignment for the 390 keV state in 62Cu

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    The 390 keV isomeric state of 62Cu is assigned as Jπ = 4+. The magnetic hyperfine interaction has been observed in the 60Ni(α, pnγ) 62Cu reaction and the deduced Larmor period is consistent with known values of g and the hyperfine field of Cu in Ni

    Bright microwave pulses from PSR B0531+21 observed with a prototype transient survey receiver

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    Recent discoveries of transient radio events have renewed interest in time-variable astrophysical phenomena. Many radio transient events are rare, requiring long observing times for reliable statistical study. The National Aeronautics and Space Administration/Jet Propulsion Laboratory\u27s Deep Space Network (DSN) tracks spacecraft nearly continuously with 13 large-aperture, low system temperature radio antennas. During normal spacecraft operations, the DSN processes only a small fraction of the pre-detection bandwidth available from these antennas; any information in the remaining bandwidth, e.g., from an astronomical source in the same antenna beam as the spacecraft, is currently ignored. As a firmware modification to the standard DSN tracking receiver, we built a prototype receiver that could be used for astronomical transient surveys. Here, we demonstrate the receiver\u27s utility through observations of bright pulses from the Crab pulsar and describe attributes of potential transient survey observations piggybacking on operational DSN tracks. © 2014. The American Astronomical Society. All rights reserved.

    Comparison of bed-up-head-elevated intubation position with Glidescope assisted tracheal intubation: a randomised, controlled, non-inferiority trial

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    Proper positioning during intubation is critical in order to increase the likelihood of success. The bed-up-headelevated (BUHE) intubation position has been shown to improve laryngeal view, reduce airway complications and prolong safe apneic time during intubation. Concurrently in the last decade, there has been an exponential increase in the use of video laryngoscopy (VL) devices, especially for difficult airway patients, as it has been shown to improve laryngeal exposure. The use of VL will increase, and may replace traditional laryngoscopy one day. In this study, we sought to determine if the BUHE intubation position is non-inferior to Glidescope-assisted intubation with regards to laryngeal exposure. In addition, we aimed to determine the differences in time required for intubation (TRI) in the two groups

    Comparison of Macintosh Laryngoscopy in Bed-up-Head–Elevated Position With GlideScope Laryngoscopy: A Randomized, Controlled, Noninferiority Trial

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    BACKGROUND: Approximately half of all difficult tracheal intubations (DTIs) are unanticipated; hence, proper positioning during intubation is critical to increase the likelihood of success. The bed-up-head–elevated (BUHE) intubation position has been shown to improve laryngeal view, reduce airway complications, and prolong safe apneic time during intubation. In this study, we sought to determine whether the BUHE intubation position is noninferior to Glidescope (GLSC)- assisted intubation with regard to laryngeal exposure. METHODS: A total of 138 American Society of Anesthesiologists (ASA) I to III patients were randomly assigned into 2 groups and underwent baseline laryngoscopy in the sniffing position. Group BUHE patients (n = 69) were then intubated in the BUHE position, while group GLSC patients (n = 69) were intubated using GLSC laryngoscopy. Laryngeal exposure was measured using Percentage of Glottic Opening (POGO) score and Cormack–Lehane (CL) grading, and noninferiority will be declared if the difference in mean POGO scores between both groups do not exceed −15% at the lower limit of a 98% confidence interval (CI). Secondary outcomes measured included time required for intubation (TRI), number of intubation attempts, use of airway adjuncts, effort during laryngoscopy, and complications during intubation. RESULTS: Mean POGO score in group BUHE was 80.14% ± 22.03%, while in group GLSC it was 86.45% ± 18.83%, with a mean difference of −6.3% (98% CI, −13.2% to 0.6%). In both groups, there was a significant improvement in mean POGO scores when compared to baseline laryngoscopy in the sniffing position (group BUHE, 25.8% ± 4.7%; group GLSC, 30.7% ± 6.8%) (P < .0001). The mean TRI was 36.23 ± 14.41 seconds in group BUHE, while group GLSC had a mean TRI of 44.33 ± 11.53 seconds (P < .0001). In patients with baseline CL 3 grading, there was no significant difference between mean POGO scores in both groups (group BUHE, 49.2% ± 19.6% versus group GLSC, 70.5% ± 29.7%; P = .054). CONCLUSIONS: In the general population, BUHE intubation position provides a noninferior laryngeal view to GLSC intubation. The laryngeal views obtained in both approaches were superior to the laryngeal view obtained in the sniffing position. In view of the many advantages of the BUHE position for intubation, the lack of proven adverse effects, the simplicity, and the costeffectiveness, we propose that clinicians should consider the BUHE position as the standard intubation position for the general population. (Anesth Analg 2020;131:210–9

    High APACHE II score and long length of bowel resection impair the outcomes in patients with necrotic bowel induced hepatic portal venous gas

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    <p>Abstract</p> <p>Background</p> <p>Hepatic portal venous gas (HPVG) is a rare but potentially lethal condition, especially when it results from intestinal ischemia. Since the literatures regarding the prognostic factors of HPVG are still scarce, we aimed to investigate the risk factor of perioperative mortality in this study.</p> <p>Methods</p> <p>We analyzed data for patients with intestinal ischemia induced HPVG by chart review in our hospital between 2000 and 2007. Factors associated with perioperative mortality were specifically analyzed.</p> <p>Results</p> <p>There were 22 consecutive patients receiving definite bowel resection. 13 cases (59.1%) died after surgical intervention. When analyzing the mortality in patients after bowel resections, high Acute Physiology And Chronic health Evaluation (APACHE) II score (<it>p < 0.01</it>) and longer length of bowel resection (<it>p </it>= 0.047) were significantly associated with mortality in univariate analyses. The complication rate was 66.7% in alive patients after definite bowel resection.</p> <p>Conclusions</p> <p>Bowel resection was the only potential life-saving therapy for patients with mesenteric ischemia induced HPVG. High APACHE II score and severity of underlying necrotic bowel determined the results in patients after bowel resection.</p

    Role of Bax in resveratrol-induced apoptosis of colorectal carcinoma cells

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    BACKGROUND: The natural plant polyphenol resveratrol present in some foods including grapes, wine, and peanuts, has been implicated in the inhibition, delay, and reversion of cellular events associated with heart diseases and tumorigenesis. Recent work has suggested that the cancer chemoprotective effect of the compound is primarily linked to its ability to induce cell division cycle arrest and apoptosis, the latter possibly through the activation of pro-apoptotic proteins such as Bax. METHODS: The expression, subcellular localization, and importance of Bax for resveratrol-provoked apoptosis were assessed in human HCT116 colon carcinoma cells and derivatives with both bax alleles inactivated. RESULTS: Low to moderate concentrations of resveratrol induced co-localization of cellular Bax protein with mitochondria, collapse of the mitochondrial membrane potential, activation of caspases 3 and 9, and finally, apoptosis. In the absence of Bax, membrane potential collapse was delayed, and apoptosis was reduced but not absent. Resveratrol inhibited the formation of colonies by both HCT116 and HCT116 bax -/- cells. CONCLUSION: Resveratrol at physiological doses can induce a Bax-mediated and a Bax-independent mitochondrial apoptosis. Both can limit the ability of the cells to form colonies

    The expression of HSP27 is associated with poor clinical outcome in intrahepatic cholangiocarcinoma

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    <p>Abstract</p> <p>Background</p> <p>The heat shock proteins (HSPs) 27-kDa (HSP27) and 72-kDa (HSP72), are ubiquitous chaperone molecules inducible in cells exposed to different stress conditions. Increased level of HSPs are reported in several human cancers, and found to be associated with the resistance to some anticancer treatments and poor prognosis. However, there is no study of the relationship between HSPs expression and patient's prognosis in intrahepatic cholangiocarcinoma (IHCCA). In this exploratory retrospective study, we investigated the expressions of HSP27 and HSP72 as potential prognostic factors in IHCCA.</p> <p>Methods</p> <p>Thirty-one paraffin-embedded samples were analyzed by immunohistochemical methods using HSP27 and HSP72 monoclonal antibodies. Proliferation rate was assessed in the same specimens by using monoclonal antibody against phosphorylated histone H3 (pHH3). Fisher's exact test was used to assess the hypothesis of independence between categorical variables in 2 × 2 tables. The ANOVA procedure was used to evaluate the association between ordinal and categorical variables. Estimates of the survival probability were calculated using the Kaplan-Meier method, and the log rank test was employed to test the null hypothesis of equality in overall survival among groups. The hazard ratio associated with HSP27 and HSP72 expression was estimated by Cox hazard-proportional regression.</p> <p>Results</p> <p>The expression of HSP27 was related to mitotic index, tumor greatest dimension, capsular and vascular invasion while the expression of HSP72 was only related to the presence of necrosis and the lymphoid infiltration. Kaplan-Maier analysis suggested that the expression of HSP27 significantly worsened the patients' median overall survival (11 ± 3.18 vs 55 ± 4.1 months, P-value = 0.0003). Moreover HSP27-positive patients exhibited the worst mean survival (7.0 ± 3.2 months) in the absence of concomitant HSP72 expression.</p> <p>Conclusion</p> <p>The expression of HSP27, likely increasing cell proliferation, tumor mass, vascular and capsular invasion, might promote aggressive tumor behaviour in IHCCA and decrease patients' survival. Immunohistochemical detection of HSP27 on routine sections may provide a reliable prognostic marker for IHCCA able to influence the therapeutic strategies for this cancer.</p

    Optimisation of NMR dynamic models I. Minimisation algorithms and their performance within the model-free and Brownian rotational diffusion spaces

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    The key to obtaining the model-free description of the dynamics of a macromolecule is the optimisation of the model-free and Brownian rotational diffusion parameters using the collected R1, R2 and steady-state NOE relaxation data. The problem of optimising the chi-squared value is often assumed to be trivial, however, the long chain of dependencies required for its calculation complicates the model-free chi-squared space. Convolutions are induced by the Lorentzian form of the spectral density functions, the linear recombinations of certain spectral density values to obtain the relaxation rates, the calculation of the NOE using the ratio of two of these rates, and finally the quadratic form of the chi-squared equation itself. Two major topological features of the model-free space complicate optimisation. The first is a long, shallow valley which commences at infinite correlation times and gradually approaches the minimum. The most severe convolution occurs for motions on two timescales in which the minimum is often located at the end of a long, deep, curved tunnel or multidimensional valley through the space. A large number of optimisation algorithms will be investigated and their performance compared to determine which techniques are suitable for use in model-free analysis. Local optimisation algorithms will be shown to be sufficient for minimisation not only within the model-free space but also for the minimisation of the Brownian rotational diffusion tensor. In addition the performance of the programs Modelfree and Dasha are investigated. A number of model-free optimisation failures were identified: the inability to slide along the limits, the singular matrix failure of the Levenberg–Marquardt minimisation algorithm, the low precision of both programs, and a bug in Modelfree. Significantly, the singular matrix failure of the Levenberg–Marquardt algorithm occurs when internal correlation times are undefined and is greatly amplified in model-free analysis by both the grid search and constraint algorithms. The program relax (http://www.nmr-relax.com) is also presented as a new software package designed for the analysis of macromolecular dynamics through the use of NMR relaxation data and which alleviates all of the problems inherent within model-free analysis

    A methoxy derivative of resveratrol analogue selectively induced activation of the mitochondrial apoptotic pathway in transformed fibroblasts

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    Resveratrol (R-3), a trihydroxy trans-stilbene from grape, inhibits multistage carcinogenesis in animal models. A resveratrol derivative 3,4,5,4′-tetrahydroxystilbene (R-4) exhibits potent growth inhibitory effect against transformed human cells. Here we report that 3,4,5,4′-tetramethoxystilbene (MR-4), converted from R-4, was more potent against cancer cell lines (WI38VA, IMR-90SV, HeLa, LNCaP, HT-29, and HepG2), but had almost no inhibitory effect on the growth of normal cells (WI38, IMR-90, BJ-T) at the concentrations tested. The IC50 value of MR-4 on the growth inhibition of transformed WI38VA human cells was 0.5 μM, as compared to the value of greater than 50 μM for the normal WI38 cells. Resveratrol, however, did not exhibit such clear differential effect and the IC50 value of R-3 for WI38VA cells was about 50 μM. The growth inhibitory effect of MR-4 correlated with the induction of apoptosis in the transformed cells. When normal WI38 cells and transformed WI38VA cells were compared, MR-4 induced increases of the Bax/Bcl-2 mRNA ratio, p53 and Bax protein level, activation of caspases, and DNA fragmentation in transformed, but not in normal cells. Further analysis revealed that MR-4 caused a rapid appearance of perinuclear aggregation of mitochondria in WI38VA but not in WI38 cells, suggesting that the mitochondria could serve as an early target of MR-4. R-3 also induced apoptosis and mitochondrial clustering but only at a much higher concentration, close to 500 μM. Taken together, the specific activation of the mitochondria-mediated apoptotic pathway could be a major reason for the striking differential growth inhibitory effect of MR-4
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