651 research outputs found
A study of trace contaminant identification by microwave double resonance spectroscopy
Trace contaminant identification using microwave double resonance spectroscop
How i do it: Lung ultrasound
In the last 15 years, a new imaging application of sonography has emerged in the clinical arena: lung ultrasound (LUS). From its traditional assessment of pleural effusions and masses, LUS has moved towards the revolutionary approach of imaging the pulmonary parenchyma, mainly as a point-of-care technique. Although limited by the presence of air, LUS has proved to be useful in the evaluation of many different acute and chronic conditions, from cardiogenic pulmonary edema to acute lung injury, from pneumothorax to pneumonia, from interstitial lung disease to pulmonary infarctions and contusions. It is especially valuable since it is a relatively easy-to-learn application of ultrasound, less technically demanding than other sonographic examinations. It is quick to perform, portable, repeatable, non-ionizing, independent from specific acoustic windows, and therefore suitable for a meaningful evaluation in many different settings, both inpatient and outpatient, in both acute and chronic conditions.In the next few years, point-of-care LUS is likely to become increasingly important in many different clinical settings, from the emergency department to the intensive care unit, from cardiology to pulmonology and nephrology wards. © 2014 Gargani and Volpicelli; licensee BioMed Central Ltd
Temperature profile in a reverse flow reactor for catalytic partial oxidation of methane by fast IR imaging
Catalytic partial oxidation of methane with air was investigated in a reverse flow reactor with commercial Rh/A1(2)O(3) catalyst in pellets. Temperature profile of the catalyst bed was measured by fast IR thermography and product composition was measured with a continuous gas analyzer. The effect of internal heat recovery on reactor performance and catalyst thermal stress is presented and compared with steady state operation. Feed direction switching time, total flow rate, and methane to oxygen ratio were investigated as process operating parameters. Data of catalyst bed temperature evolution during the flow cycle are presented and discussed. Comparison of dynamic heat integration with external feed preheating in terms of product composition and catalyst temperature profile is also presented. (C) 2008 American Institute of Chemical Engineers
Stereoselective Solvolysis in the Synthesis of Dorzolamide Intermediates
The key intermediate in the synthesis of dorzolamide,(4S,6S)-methyl-5,6-dihydro-4H-thieno[2,3-b]thiopyran-4-ol-7,7-dioxide,can beobtained in the diastereoisomerically pure form in two straightforwardsteps starting from diastereoisomeric mixtures of cis/trans-(6S)-6-methyl-5,6-dihydro-4H-thieno[2,3-b]thiopyran-4-yl acetate,regardless of their ratio. The reaction of crucial importance in thisscheme is a remarkably stereoselective solvolysis of the acetate esterin an acetone/phosphate buffer mixture as the solvent system. Investigationof this so far unrecognized stereoselective reaction reveals thatit proceeds via an S(N)1-like pathway as indicated by thecorrelation of the solvolysis rate constants with the Y (OTs) values of different solvent mixtures and by trappingof the reaction intermediate with sodium azide. The structure of (4S,6S)-methyl-5,6-dihydro-4H-thieno[2,3-b]thiopyran-4-ol-7,7-dioxide was confirmedby single-crystal X-ray analysis
Dopamine: The Neuromodulator of Long-Term Synaptic Plasticity, Reward and Movement Control
Dopamine (DA) is a key neurotransmitter involved in multiple physiological functions including motor control, modulation of affective and emotional states, reward mechanisms, reinforcement of behavior, and selected higher cognitive functions. Dysfunction in dopaminergic transmission is recognized as a core alteration in several devastating neurological and psychiatric disorders, including Parkinson's disease (PD), schizophrenia, bipolar disorder, attention deficit hyperactivity disorder (ADHD) and addiction. Here we will discuss the current insights on the role of DA in motor control and reward learning mechanisms and its involvement in the modulation of synaptic dynamics through different pathways. In particular, we will consider the role of DA as neuromodulator of two forms of synaptic plasticity, known as long-term potentiation (LTP) and long-term depression (LTD) in several cortical and subcortical areas. Finally, we will delineate how the effect of DA on dendritic spines places this molecule at the interface between the motor and the cognitive systems. Specifically, we will be focusing on PD, vascular dementia, and schizophrenia
Phantom model and scoring system to assess ability in ultrasound-guided chest drain positioning
Background: Chest tube positioning is an invasive procedure associated with potentially serious injuries. In the last few years, we have been running a project directed at developing a practical simulator of a surgical procedure taught on our medical training program. The phantom model reconstructs the pleural anatomy, visible by lung ultrasound, used for the assessed performance of the Seldinger technique. The aim of the present study was to investigate the validity of this simulation technology for assessing residents in anesthesia and intensive care medicine; specifically, their skill in positioning a US-guided chest tube drain was tested using the simulator device. The second aim of the paper was to evaluate the learning curve of our residents over their 5-year study course and validate the phantom scoring system. Methods: This was a prospective, single-blinded observational study. Participants were recruited from residents in anesthesia and intensive care medicine and divided into two groups: \u2018Novice\u2019 and \u2018Expert,\u2019 based on the course year attended (years 1, 2, and 3 vs. years 4 and 5, respectively). We asked them to position a chest tube drain in a phantom model, guided by ultrasound, to drain a simulated pleural effusion. Each subject performed two tests that simulated pleural effusions of 4 and 2\ua0cm, respectively. Every step of the maneuver was constantly monitored and the performance scored by the investigators. We then performed a Spearman correlation analysis to evaluate the effect of experience level on the performance of the two groups of residents. Results: Thirty-one residents were included in this study: 20 in the Novice group and 11 in the Expert group. The mean performance rating score was 0.75\ua0\ub1\ua04.38 for the Novice Group and 5.91\ua0\ub1\ua03.75 for the Expert group (p\ua0=\ua00.0026). The Spearman correlation analysis examining the relationship between year of residency and performance rating score confirmed a positive correlation (r\ua0=\ua00.58, p\ua0=\ua00.0006). Post-test trend analysis revealed a statistically significant linear trend for skill growth across time, i.e., course year (p\ua0=\ua00.0022). Conclusions: Our simulated procedure using a phantom model of lung anatomy can accurately and reliably be used to assess the skill levels of operators in their ability to drain pleural effusion
Could the use of bedside lung ultrasound reduce the number of chest x-rays in the intensive care unit?
Background: Lung ultrasound can be used as an alternative to chest radiography (CXR) for the diagnosis and follow-up of various lung diseases in the intensive care unit (ICU). Our aim was to evaluate the influence that introducing a routine daily use of lung ultrasound in critically ill patients may have on the number of CXRs and as a consequence, on medical costs and radiation exposure. Methods: Data were collected by conducting a retrospective evaluation of the medical records of adult patients who needed thoracic imaging and were admitted to our academic polyvalent ICU. We compared the number of CXRs and relative costs before and after the introduction of lung ultrasound in our ICU. Results: A total of 4134 medical records were collected from January 2010 to December 2014. We divided our population into two groups, before (Group A, 1869 patients) and after (Group B, 2265 patients) the introduction of a routine use of LUS in July 2012. Group A performed a higher number of CXRs compared to Group B (1810 vs 961, P = 0.012), at an average of 0.97 vs 0.42 exams per patient. The estimated reduction of costs between Groups A and B obtained after the introduction of LUS, was 57%. No statistically significant difference between the outcome parameters of the two groups was observed. Conclusions: Lung ultrasound was effective in reducing the number of CXRs and relative medical costs and radiation exposure in ICU, without affecting patient outcome
Multicentre pilot study evaluation of lung ultrasound for the management of paediatric pneumonia in low-resource settings: a study protocol
Introduction: Pneumonia is the leading infectious cause of death among children under 5 years of age worldwide. However, pneumonia is challenging to diagnose. Lung ultrasound (LUS) is a promising diagnostic technology. Further evidence is needed to better understand the role of LUS as a tool for the diagnosis of childhood pneumonia in low-resource settings. Methods and analysis: This study aims to pilot LUS in Mozambique and Pakistan and to generate evidence regarding the use of LUS as a diagnostic tool for childhood pneumonia. Children with cough \u3c14 days with chest indrawing (n=230) and without chest indrawing (n=40) are enrolled. World Health Organization Integrated Management of Childhood Illness assessment is performed at enrolment, along with a chest radiograph and LUS examination. Respiratory and blood specimens are collected for viral and bacterial testing and biomarker assessment. Enrolled children are followed for 14 days (in person) and 30 days (phone call) post-enrolment with LUS examinations performed on Days 2, 6 and 14. Qualitative and quantitative data are also collected to assess feasibility, usability and acceptability of LUS among healthcare providers and caregivers. The primary outcome is LUS findings at enrolment with secondary outcomes including patient outcomes, repeat LUS findings, viral and bacterial test results, and patient status after 14 and 30 days of follow-up. Ethics and dissemination: This trial was approved by the Western Institutional Review Board as well as local ethics review committees at each site. We plan to disseminate study results in peer-reviewed journals and international conferences. Trial registration number: NCT03187067
Assessment of Pleural Effusion and Small Pleural Drain Insertion by Resident Doctors in an Intensive Care Unit: An Observational Study
Risk of Seven-Day Worsening and Death: A New Clinically Derived COVID-19 Score
This monocentric, retrospective, two-stage observational study aimed to recognize the risk factors for a poor outcome in patients hospitalized with SARS-CoV-2 infection, and to develop and validate a risk score that identifies subjects at risk of worsening, death, or both. The data of patients with SARS-CoV-2 infection during the first wave of the pandemic were collected and analyzed as a derivation cohort. Variables with predictive properties were used to construct a prognostic score, which was tried out on a validation cohort enrolled during the second wave. The derivation cohort included 494 patients; the median age was 62 and the overall fatality rate was 22.3%. In a multivariable analysis, age, oxygen saturation, neutrophil-to-lymphocyte ratio, C-reactive protein and lactate dehydrogenase were independent predictors of death and composed the score. A cutoff value of 3 demonstrated a sensitivity (Se), specificity (Sp), positive predictive value (PPV) and negative predictive value (NPV) of 93.5%, 68.5%, 47.4% and 97.2% for death, and 84.9%, 84.5%, 79.6% and 87.9% for worsening, respectively. The validation cohort included 415 subjects. The score application showed a Se, Sp, PPV and NPV of 93.4%, 61.6%, 29.5% and 98.1% for death, and 81%, 76.3%, 72.1% and 84.1% for worsening, respectively. We propose a new clinical, easy and reliable score to predict the outcome in hospitalized SARS-CoV-2 patients
- …