742 research outputs found

    Internal hysteresis experienced on a high pressure syn gas compressor

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    A vibration instability phenomenon experienced in operating high pressure syn gas centrifugal compressors in two ammonia plants is described. The compressors were monitored by orbit and spectrum analysis for changes from baseline readings. It is found that internal hysteresis was the major destabilizing force; however, the problem was further complicated by seal lockup at the suction end of the compressor. A coupling lockup problem and a coupling fit problem, which frettage of the shaft, are also considered as contributors to the self excited vibrations

    Use of clinical guidelines in cardiology practice in Sudan

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    Rationale, aims, and objective: The aim of this study was to explore the views of prescribers in cardiology in Sudan about the use of guidelines in clinical practice and the extent to which guidelines whether national or international can be adopted in clinical practice in Sudan. Methods: Interviews were conducted with the consultants in 2 of the main cardiac hospitals in Sudan. This was followed by a survey amongst the doctors in the hospitals to examine the views of a larger population of prescribers about the matter investigated. Results: Twelve consultants were interviewed, and 47 prescribers (60%) replied to the questionnaire that followed. Most doctors relied on foreign guidelines to prescribe for their patients. The doctors acknowledged the limitation of using foreign guidelines in Sudan. A number of doctors were not in favour of following any guidelines, as they perceived that the practice in Sudan does not allow implementation of guidelines. Conclusion: The prescribers in Sudan had to rely on guidelines made in foreign countries if they want to get the benefit of evidence‐based medicine to their patients, but they had to find a way to adapt these guidelines to their patients and to the health care system they are working within. However, it is not known if this adaptation of foreign guidelines is providing the benefits intended or is risking evidence‐based medicine

    Views on a brief mindfulness intervention among patients with long-term illness.

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    BACKGROUND: Chronic illness is the leading cause of death in the UK and worldwide. Psychological therapies to support self-management have been shown to play an important role in helping those with chronic illness cope; more recently, the therapeutic benefits of mindfulness approaches have become evident for managing depression and other distressing emotions. Brief guided mindfulness interventions, are more convenient than intensive traditional programmes requiring regular attendance but have been less explored. This study assessed views on a brief (i.e., 10 min) mindfulness intervention for those with specific long-term illnesses. METHODS: Semi-structured interviews and focus groups were conducted with chronic illness patient groups (i.e., chronic obstructive pulmonary disease, chronic pain and cardiovascular disease), designed to capture the acceptability and feasibility of the intervention. The interviews were conducted after use of a mindfulness based audio in clinic and, one week later, after use in the patient's own environment. Interviews were recorded, transcribed and analysed using thematic analysis. RESULTS: In total, a combination of 18 interviews and focus groups were conducted among 14 patients. Recruitment was most successful with chronic pain patients. All patients reported benefits such as feelings of relaxation and improved coping with symptoms. While the wording and content of the audio were generally well received, it was suggested that the length could be increased, as it felt rushed, and that more guidance about the purpose of mindfulness, and when to use it, was needed. CONCLUSIONS: A brief mindfulness intervention was well accepted among patients with long-term illness. The intervention may benefit by being lengthened and by offering further guidance on its use

    Elevated levels of 8-OHdG and PARK7/DJ-1 in peri-implantitis mucosa

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    BackgroundReactive oxygen species contribute to periodontal tissue homeostasis under control of anti-oxidative responses. Disruption in this balance induces severe inflammation and extended tissue degradation.PurposeAim of this study was to identify the expression levels of nuclear factor, erythroid 2 like 2 (NFE2L2/NRF2), Parkinsonism associated deglycase (PARK7/DJ-1), kelch-like ECH associated protein 1 (KEAP1), and 8-hydroxy-deoxyguanosine (8-OHdG) in peri-implant mucosal tissues affected by peri-implantitis, and to compare the levels to those of periodontally diseased and healthy tissue samples.MethodsTissue biopsies were collected from systemically healthy, non-smoking 12 peri-implantitis patients, 13 periodontitis patients, and 13 periodontally healthy controls. Expression levels of NFE2L2/NRF2, PARK7/DJ-1, KEAP1, and 8-OHdG in tissue samples were analyzed immunohistochemically. Statistical analysis was performed by one-way ANOVA with Tukey's HSD test.ResultsInflammatory cell infiltration in the connective tissue and loss of architecture in the spinous layer of the epithelium were prominent in peri-implantitis. Proportions of 8-OHdG and PARK7/DJ-1 expressing cells were elevated in both peri-implantitis (P = .025 for 8-OHdG and P = .014 for PARK7/DJ-1) and periodontitis (P = .038 for 8-OHdG and P = .012 for PARK7/DJ-1) groups in comparison with controls. Staining intensities of 8-OHdG and PARK7/DJ-1 were higher in the periodontitis and peri-implantitis groups than in the control (P < .01) groups. There was no difference in the expression levels of NFE2L2/NRF2 between the groups. KEAP1 was not observed in any tissue sample.ConclusionsPeri-implantitis is characterized by severe inflammation and architectural changes in the epithelium and connective tissue. The expressions of 8-OHdG and PARK7/DJ-1 are elevated in both peri-implantitis and periodontitis

    In vitro MATURATION OF DROMEDARY SHE-CAMEL OOCYTES EXPOSED TO LASER IRRADIATION

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    The objective of this study was to study the effect of laser irradiation on maturation rate of dromedary she-camel oocytes.  Although in vitro fertilization (IVF) technique in she-camel has been established, but maturation rate of camel oocytes is still low comparing with other animal species. Several studies performed to improve in-vitro maturation rate using different types of media with different incubation times. In order to establish high sensitive and low cost maturation improvement technique, laser irradiation has been suggested in the present work. Cumulus oocytes complexes (COCʼs) were collected from ovaries by aspiration method and grade (A) oocytes were chosen and divided into five different groups, 62 oocytes served as control group,  an un-irradiated (group 1), 64 oocytes exposed to 2 minutes of laser irradiation (group 2), 57 oocytes exposed to 3 minutes of laser irradiation (group 3), 49 oocytes exposed to 4 minutes of laser irradiation (group 4) and 52 oocytes exposed to 5 minutes of laser irradiation (group 5) with a total output power of 3 mW for different exposure durations; 2, 3, 4 and 5 minutes.  Afterwards, oocytes were matured in TCM-199 medium at 38.5oC and 5% CO2 in humidified air for 42 h. Maturation rate was calculated based on expulsion of the first polar body and statistically analyzed by one way ANOVA test.   The obtained results showed that, the oocytes reached germinal vesicles (GV) which exposed to laser beam for 5 minutes at 488 nm wavelength represent significantly (P<0.05) the highest value (42.31%) compared to control (not irradiated, 16.13%). However, other groups of GV showed insignificant differences with the control group. The metaphase II (M II) in the control oocytes represents significantly (P<0.05) the highest value (75.81%) compared to 3-5 minutes exposed groups. The degenerated oocytes exposed to laser beam for 5 minutes at 488 nm wavelength represent significantly (P<0.05) the highest value (40.38%) compared to control (not irradiated, 8.06%). In conclusion‚ these results indicated that the exposure of laser irradiation for 2 minutes may improve in-vitro nuclear maturation of immature oocytes in dromedary she-camels as compared to other durations (3-5 minutes) at 488 nm wavelength (blue laser)

    Chylous ascites following robotic lymph node dissection on a patient with metastatic cervical carcinoma

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    Chylous ascites is an uncommon postoperative complication of gynecological surgery. We report a case of chylous ascites following a robotic lymph node dissection for a cervical carcinoma. A 38-year-old woman with IB2 cervical adenocarcinoma with a palpable 3 cm left external iliac lymph node was taken to the operating room for robotic-assisted laparoscopic pelvic and para-aortic lymph node dissection. Patient was discharged on postoperative day 2 after an apparent uncomplicated procedure. The patient was readmitted the hospital on postoperative day 9 with abdominal distention and a CT-scan revealed free fluid in the abdomen and pelvis. A paracentesis demonstrated milky-fluid with an elevated concentration of triglycerides, confirming the diagnosis of chylous ascites. She recovered well with conservative measures. The risk of postoperative chylous ascites following lymph node dissection is still present despite the utilization of new technologies such as the da Vinci robot

    L5 Spinal Nerve Axotomy Induces Distinct Electrophysiological Changes in Axotomized L5- and Adjacent L4-Dorsal Root Ganglion Neurons in Rats .

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    Peripheral neuropathic pain (PNP) is a major health problem for which effective drug treatment is lacking. Its underlying neuronal mechanisms are still illusive, but pre-clinical studies using animal models of PNP including the L5-spinal nerve axotomy (L5-SNA) model, suggest that it is partly caused by excitability changes in dorsal root ganglion (DRG) neurons. L5-SNA results in two DRG neuronal groups: (1) axotomized/damaged neurons in L5- plus some in L4-DRGs, and (2) ipsilateral L4-neurons with intact/uninjured fibers intermingling with degenerating L5-fibers. The axotomized neurons are deprived of peripherally derived trophic factors and degenerate causing neuroinflammation, whereas the uninjured L4-neuorns are subject to increased trophic factors and neuroinflammation associated with Wallerian degeneration of axotomized L5-nerve fibers. Whether these two groups of DRG neurons exhibit similar or distinct electrophysiological changes after L5-SNA remains unresolved. Conflicting evidence for this may result from some studies assuming that all L4-fibers are undamaged. Here, we recorded somatic action potentials (APs) intracellularly from C- and A-fiber L4/L5 DRG neurons to examine our hypothesis that L5-SNA would induce distinct electrophysiological changes in the two populations of DRG neurons. Consistent with this hypothesis, we found (7 days post-SNA), in SNA rats with established pain hypersensitivity, slower AP kinetics in axotomized L5-neurons and faster AP kinetics in L4-nociceptive neurons including decreased rise time in Aδ-and Aβ-fiber nociceptors, and after-hyperpolarization duration in Aβ-fiber nociceptors. We also found several changes in axotomized L5-neurons but not in L4-nociceptive neurons, and some changes in L4-nociceptive but not L5-neurons. The faster AP kinetics (decreased refractory period) in L4-nociceptive neurons that are consistent with their reported hyperexcitability may lead to repetitive firing and thus provide enhanced afferent input necessary for initiating and/or maintaining PNP development. The changes in axotomized L5-neurons may contribute to the central mechanisms of PNP via enhanced neurotransmitter release in the central nervous system (CNS)

    Unmasking the interplay between mTOR and Nox4: novel insights into the mechanism connecting diabetes and cancer

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    Cancer was recently annexed to diabetic complications. Furthermore, recent studies suggest that cancer can increase the risk of diabetes. Consequently, diabetes and cancer share many risk factors, but the cellular and molecular pathways correlating diabetes and colon and rectal cancer (CRC) remain far from understood. In this study, we assess the effect of hyperglycemia on cancer cell aggressiveness in human colon epithelial adenocarcinoma cells in vitro and in an experimental animal model of CRC. Our results show that Nox (NADPH oxidase enzyme) 4-induced reactive oxygen species (ROS) production is deregulated in both diabetes and CRC. This is paralleled by inactivation of the AMPK and activation of the mammalian target of rapamycin (mTOR) C1 signaling pathways, resulting in 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) accumulation, induction of DNA damage, and exacerbation of cancer cell aggressiveness, thus contributing to the genomic instability and predisposition to increased tumorigenesis in the diabetic milieu. Pharmacologic activation of AMPK, inhibition of mTORC1, or blockade of Nox4 reduce ROS production, restore the homeostatic signaling of 8-oxoguanine DNA glycosylase/8-oxodG, and lessen the progression of CRC malignancy in a diabetic milieu. Taken together, our results identify the AMPK/mTORC1/Nox4 signaling axis as a molecular switch correlating diabetes and CRC. Modulating this pathway may be a strategic target of therapeutic potential aimed at reversing or slowing the progression of CRC in patients with or without diabetes.-Mroueh, F. M., Noureldein, M., Zeidan, Y. H., Boutary, S., Irani, S. A. M., Eid, S., Haddad, M., Barakat, R., Harb, F., Costantine, J., Kanj, R., Sauleau, E.-A., Ouhtit, A., Azar, S. T., Eid, A. H., Eid, A. A. Unmasking the interplay between mTOR and Nox4: novel insights into the mechanism connecting diabetes and cancer.Scopu

    Effects of a brief mindfulness-based intervention on emotional regulation and levels of mindfulness in senior students

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    Mindfulness-based interventions have been applied in diverse populations and achieved mental health benefits. This study examined the effects of a brief mindfulness program for emotional regulation and levels of mindfulness on senior students in Brazil. The intervention consisted of six weekly meetings attended by 30 participants. It is a pre-experimental research, with pre- and post-test comparative and correlation measurements. The preliminary results, which relied on parametrical and non-parametrical tests, revealed a reduction in total emotional regulation difficulties (p = 0.0001; r = − 0.55). Also, there was an increase in the levels of mindfulness in the subtests for both dimensions under evaluation: “Awareness” (p = 0.0001; d = 0.77) and “Acceptance” (p = 0.048; d = 0.37). By associating the amount of meditative practices performed by students with the variables, a significant positive correlation was found with the mindfulness dimension “Awareness” (rP = 0.422; p = 0.020), and there was a significant negative correlation with Difficulties in emotion regulation (rS = − 0.478; p = 0.008) and with its respective subscales “Non-acceptance” (rS = − 0.654; p = 0.0001) and “Clarity” (rS = − 0.463; p = 0.010). In conclusion, the application of a brief mindfulness-based intervention is promising in Brazilian university contexts; moreover, it can bring benefits to students, e.g., an increase in emotion regulation as well as in levels of mindfulness. We suggest that further research should use an experimental design and follow-up.info:eu-repo/semantics/publishedVersio

    Meta-analysis of neural systems underlying placebo analgesia from individual participant fMRI data

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    The brain systems underlying placebo analgesia are insufficiently understood. Here we performed a systematic, participant-level meta-analysis of experimental functional neuroimaging studies of evoked pain under stimulus-intensity-matched placebo and control conditions, encompassing 603 healthy participants from 20 (out of 28 eligible) studies. We find that placebo vs. control treatments induce small, widespread reductions in pain-related activity, particularly in regions belonging to ventral attention (including mid-insula) and somatomotor networks (including posterior insula). Behavioral placebo analgesia correlates with reduced pain-related activity in these networks and the thalamus, habenula, mid-cingulate, and supplementary motor area. Placebo-associated activity increases occur mainly in frontoparietal regions, with high between-study heterogeneity. We conclude that placebo treatments affect pain-related activity in multiple brain areas, which may reflect changes in nociception and/or other affective and decision-making processes surrounding pain. Between-study heterogeneity suggests that placebo analgesia is a multi-faceted phenomenon involving multiple cerebral mechanisms that differ across studies
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