Efficacy of Handheld Ultrasound in Medical Education: A Comprehensive Systematic Review and Narrative Analysis.

Miniaturization has made ultrasound (US) technology ultraportable and, in association with their relatively low cost, made handheld devices attractive for medical education training programs. However, performing an ultrasound requires complex skills, and it is unclear whether handheld devices are suitable for the training of novices. Our study aimed to identify to what extent handheld US devices can be employed in medical undergraduates' and residents' education. We selected studies that evaluate the results obtained by students and/or residents who have participated in ultrasound training programs using handheld devices. The studies were included if they reported post-test (pre-test optional) achievements or a comparison with a control group (a group of experts or novices who underwent a different intervention). Twenty-six studies were selected, and their characteristics were summarized. Handheld ultrasound devices were used in training programs to learn echocardiography, abdominal, and/or musculoskeletal ultrasound. Statistically significant progress was noted in the ability of naïve participants to capture and interpret ultrasound images, but training duration influenced the outcomes. While ultrasound training using handheld devices has proven to be feasible for various body regions and purposes (e.g., better understanding of anatomy, clinical applications, etc.), the long-term impacts of handheld education interventions must be considered in addition to the short-term results to outline guidelines for targeted educational needs.

Handheld Echocardiography Measurements Concordance and Findings Agreement: An Exploratory Study.

The professional association has already developed guidelines on the appropriate use of handheld ultrasound devices, especially in an emergency setting. Handheld ultrasound devices are seen as the 'stethoscope of the future' to assist in physical examination. Our exploratory study evaluated whether the measurements of cardiovascular structures and the agreement in identifying aortic, mitral, and tricuspid valve pathology made by a resident with a handheld device (HH, Kosmos Torso-One) reach the results reported by an experienced examiner who used a high-end device (STD). Patients referred for cardiology examination in a single center from June to August 2022 were eligible for the study. Patients who agreed to participate underwent two heart ultrasound examinations scanned by the same two operators. A cardiology resident performed the first examination with a HH ultrasound device, and an experienced examiner performed the second examination with an STD device. Forty-three consecutive patients were eligible, and forty-two were included in the study. One obese patient was excluded because none of the examiners succeeded in performing the heart examination. The measurements obtained with HH were generally higher than those obtained with STD, with the highest mean difference of 0.4 mm, but without significant differences (all 95% confidence intervals of the differences contain the value of 0). For valvular disease, the lowest agreement was observed for mitral valve regurgitation (26/42, with a Kappa concordance coefficient of 0.5321), which was missed in almost half of the patients with mild regurgitation and underestimated in half of the patients with moderate mitral regurgitation. The measurements performed by the resident with the handheld Kosmos Torso-One device showed high concordance with those conducted by the experienced examiner with a larger high-end ultrasound device. The learning curve of the resident could explain the limited performance in identifying valvular pathologies between examiners.

Effectiveness of Ultrasound Cardiovascular Images in Teaching Anatomy: A Pilot Study of an Eight-Hour Training Exposure.

The present study aimed to evaluate the students' progress in evaluating ultrasound (US) and cadaveric cardiac images and long-time retention of information. First-year medical students were invited to participate in four two-hour online lectures during one week voluntarily. The students were trained to recognize cardiovascular anatomical structures on US and cadaveric images during the intervention. The participants' abilities to identify specific anatomical structures were tested before, immediately after and six months after the training. A group of second-year students without US training participated as a control group and filled the same test once. Ninety-one first-year students agreed to participate, and forty-nine completed all three tests. The performances in the correct identification of cardiovascular structures on the US images significantly improved after the training but significantly decreased after six months. In the intervention group, the accurate identification of cardiovascular structures was significantly higher on cadaveric images (80% vs. 53%, p-value < 0.0001, n = 91 at post-training; 70% vs. 33%, p-value < 0.0001, n = 49 at 6 months after training). The correct answers percentage score in the control group varied from 6.7% to 66.7% for US cardiovascular anatomical without a significant difference than the intervention group (p-value = 0.7651). First-year students' knowledge of heart US anatomy proved less effective than cadaveric images, significantly improved after training and decreased over time, indicating the need for repetition reinforcement.

Friction and Wear Performance Evaluation of Bio-Lubricants and DLC Coatings on Cam/Tappet Interface of Internal Combustion Engines.

The environmental concerns associated with artificially formulated engine oils have forced a shift towards bio-based lubricants. The deposition of hard coatings on engine components and migrating to environmentally friendly green lubricants can help in this regard. Chemically modified forms of vegetable oils, with better low-temperature characteristics and enhanced thermo-oxidative stability, are suitable substitutes to conventional lubricant base oils. The research presented in this manuscript was undertaken to experimentally investigate the wear and friction performance of a possible future generation of an environmentally friendly bio-based lubricant as a potential replacement for conventional engine lubricants. In order to quantify the tribological benefits which can be gained by the deposition of DLC coatings, (an (a-C:H) hydrogenated DLC coating and an (a-C:H:W) tungsten-doped DLC coating) were applied on the cam/tappet interface of a direct acting valve train assembly of an internal combustion engine. The tribological correlation between DLC-coated engine components, lubricant base oils and lubricant additives have been thoroughly investigated in this study using actual engine operating conditions. Two additive-free base oils (polyalphaolefines (PAO) and chemically-modified palm oil (TMP)) and two multi-additive-containing lubricants were used in this investigation. Real-time drive torque was measured to determine the friction force, detailed post-test analysis was performed, which involved the use of a specialized jig to measure camlobe wear. An optical profilometer was used to measure the wear on the tappet, high-resolution scanning electron microscopy was employed to study the wear mechanism and energy-dispersive X-ray spectroscopy was performed on the tested samples to qualitatively access the degradation of the coating. When using additive-free TMP, a low friction coefficient was observed for the cam/tappet interface. The presence of additives further improved the friction characteristics of TMP, resulting in reduced average friction torque values. A tremendous enhancement in wear performance was recorded with a-C:H-coated parts and the coating was able to withstand the test conditions with little or no delamination.

Hand-Held Ultrasound of the Lung: A Systematic Review.

BACKGROUND: The ultrasound examination is a surface technique with an accurate diagnosis of pathological processes adjacent to the pleural line. The purpose of the study was to evaluate the role of hand-held ultrasound devices (visual stethoscopes) in the diagnosis of peripheral lung disease. METHODS: We conducted a systematic search of literature comparing the diagnostic accuracy of truly hand-held ultrasound devices compared to conventional high-end ultrasound devices, chest X-rays, thoracic CT (computer tomography), or physical examinations to diagnose peripheral lung lesions. ScienceDirect, PubMed, and PubMed Central bibliographic databases were searched within a time limit of 15 years. RESULTS: The applied search strategy retrieved 439 studies after removing duplicates; 34 were selected for full-text review, and 15 articles met all inclusion criteria and were included in the analysis. When comparing hand-held ultrasound devices to chest X-rays, negative predictive values were above 90%, while positive predictive values tended to be lower (from 35% to 75.8%). Hand-held ultrasound reached a correlation of 0.99 as associated with conventional ultrasound with a Bland-Altman bias close to zero. CONCLUSIONS: Being accessible, radiation-free, and comparatively easy to decontaminate, hand-held ultrasound devices could represent a reliable tool for evaluating peripheral lung diseases. This method can be successfully employed as an alternative to repeated X-ray examinations for peripheral lung disease monitoring.

Correction: Development of a reverse transcription recombinase polymerase amplification assay for rapid and direct visual detection of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2).

[This corrects the article DOI: 10.1371/journal.pone.0245164.].

Development of a reverse transcription recombinase polymerase amplification assay for rapid and direct visual detection of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2).

Rapid diagnosis is an important intervention in managing the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) outbreak. Real time reverse transcription polymerase chain reaction (RT-qPCR) remains the primary means for diagnosing the new virus strain but it is time consuming and costly. Recombinase polymerase amplification (RPA) is an isothermal amplification assay that does not require a PCR machine. It is an affordable, rapid, and simple assay. In this study, we developed and optimized a sensitive reverse transcription (RT)-RPA assay for the rapid detection of SARS-CoV-2 using SYBR Green I and/or lateral flow (LF) strip. The analytical sensitivity and specificity of the RT-RPA assay were tested by using 10-fold serial diluted synthetic RNA and genomic RNA of similar viruses, respectively. Clinical sensitivity and specificity of the RT-RPA assay were carried out using 78 positive and 35 negative nasopharyngeal samples. The detection limit of both RPA and RT-qPCR assays was 7.659 and 5 copies/µL RNA, respectively with no cross reactivity with other viruses. The clinical sensitivity and specificity of RT-RPA were 98% and 100%, respectively. Our study showed that RT-RPA represents a viable alternative to RT-qPCR for the detection of SARS-CoV-2, especially in areas with limited infrastructure.

Lymphoproliferative disorder in a lung transplant recipient.

Post-transplantation lymphoproliferative disorder (PTLD) is uncommon following solid organ transplantation. We present a case of PTLD presenting as hematochezia and abdominal pain in a 66-year-old man, who had undergone bilateral lung transplantation with alemtuzumab induction 7 months prior to presentation. The transplant serologic status was "high-risk" for the presence of both Epstein-Barr virus (EBV) serologies in the donor and negative serologies in the recipient. Biopsies taken during colonoscopy stained strongly positive for EBV-encoded RNA. Mediastinal lymph node biopsies also showed atypical, EBV-positive lymphohistiocytic infiltration with focal necrosis. The patient's hospital course was complicated by treatment side effects, most notably bowel perforation following rituximab. In this case report the topic of PTLD is reviewed and consideration is given to whether alemtuzumab induction may have contributed to the patient's development of PTLD.

Life-threatening hemoptysis following mitral valvuloplasty for rheumatic mitral stenosis.

BACKGROUND: Massive hemoptysis is a rare complication of rheumatic mitral valve stenosis. Its recurrence following successful initial treatment of the stenosis has not, to our knowledge, been described. CASE REPORT: We describe a 58-year-old African American woman with a history of balloon valvuloplasty for the treatment of severe rheumatic mitral valve stenosis who presented to our institution with massive life-threatening hemoptysis due to recurrent mitral valve stenosis. Repeat balloon valvuloplasty was complicated postoperatively by severe mitral regurgitation and the patient expired from refractory cardiopulmonary collapse not amenable to further intervention. CONCLUSION: Life-threatening hemoptysis is a medical emergency requiring rapid source identification and treatment of the underlying etiology. A high degree of suspicion should be maintained for recurrence of mitral valve stenosis in patients presenting with life-threatening hemoptysis and risk factors of rheumatic heart disease, regardless of previous surgical management or unilateral chest x-ray signs.

Influence of polymethyl acrylate additive on the formation of particulate matter and NOX emission of a biodiesel-diesel-fueled engine.

The aim of this study is to investigate the effect of the polymethyl acrylate (PMA) additive on the formation of particulate matter (PM) and nitrogen oxide (NOX) emission from a diesel coconut and/or Calophyllum inophyllum biodiesel-fueled engine. The physicochemical properties of 20% of coconut and/or C. inophyllum biodiesel-diesel blend (B20), 0.03 wt% of PMA with B20 (B20P), and diesel fuel were measured and compared to ASTM D6751, D7467, and EN 14214 standard. The test results showed that the addition of PMA additive with B20 significantly improves the cold-flow properties such as pour point (PP), cloud point (CP), and cold filter plugging point (CFPP). The addition of PMA additives reduced the engine's brake-specific energy consumption of all tested fuels. Engine emission results showed that the additive-added fuel reduce PM concentration than B20 and diesel, whereas the PM size and NOX emission both increased than B20 fuel and baseline diesel fuel. Also, the effect of adding PMA into B20 reduced Carbon (C), Aluminum (Al), Potassium (K), and volatile materials in the soot, whereas it increased Oxygen (O), Fluorine (F), Zinc (Zn), Barium (Ba), Chlorine (Cl), Sodium (Na), and fixed carbon. The scanning electron microscope (SEM) results for B20P showed the lower agglomeration than B20 and diesel fuel. Therefore, B20P fuel can be used as an alternative to diesel fuel in diesel engines to lower the harmful emissions without compromising the fuel quality.

Attempts to minimize nitrogen oxide emission from diesel engine by using antioxidant-treated diesel-biodiesel blend.

The study represents a comprehensive analysis of engine exhaust emission variation from a compression ignition (CI) diesel engine fueled with diesel-biodiesel blends. Biodiesel used in this investigation was produced through transesterification procedure from Moringa oleifera oil. A single cylinder, four-stroke, water-cooled, naturally aspirated diesel engine was used for this purpose. The pollutants from the exhaust of the engine that are monitored in this study are nitrogen oxide (NO), carbon monoxide (CO), hydrocarbon (HC), and smoke opacity. Engine combustion and performance parameters are also measured together with exhaust emission data. Some researchers have reported that the reason for higher NO emission of biodiesel is higher prompt NO formation. The use of antioxidant-treated biodiesel in a diesel engine is a promising approach because antioxidants reduce the formation of free radicals, which are responsible for the formation of prompt NO during combustion. Two different antioxidant additives namely 2,6-di-tert-butyl-4-methylphenol (BHT) and 2,2'-methylenebis(4-methyl-6-tert-butylphenol) (MBEBP) were individually dissolved at a concentration of 1% by volume in MB30 (30% moringa biodiesel with 70% diesel) fuel blend to investigate and compare NO as well as other emissions. The result shows that both antioxidants reduced NO emission significantly; however, HC, CO, and smoke were found slightly higher compared to pure biodiesel blends, but not more than the baseline fuel diesel. The result also shows that both antioxidants were quite effective in reducing peak heat release rate (HRR) and brake-specific fuel consumption (BSFC) as well as improving brake thermal efficiency (BTE) and oxidation stability. Based on this study, antioxidant-treated M. oleifera biodiesel blend (MB30) can be used as a very promising alternative source of fuel in diesel engine without any modifications.