A Manual for Ultrasound Guided Intravenous Access: Allay your Fears, Alleviate with Humor, Approach with Confidence

“Hey, can you help get IV access on a patient? The nurses have tried many times already.” If this message fills your heart with trepidation, it may be because you do not have a systematic approach to ultrasound guided intravenous catheter (IV) placement or any prior training in this procedure. At our institution, after failed nursing attempts, the responsibility for obtaining IV access may fall on the physician. Early in the year, this physician may be an intern who has limited experience with IV access, let alone ultrasound guided IV placement. They may have previously undergone a brief training course using a low-fidelity gel model simulation. However, this form of training is often insufficient and impractical. The purpose of this manual is to allay your fears and anxieties and teach a systematic approach to ultrasound guided IV access. It is a guide that provides technical tricks and steps learned from several hundred hours of experience. And because we all know how enjoyable it is to read a dry step-by-step instruction manual, this guide is written in a humorous light for your reading pleasure

An Educational Case for Applying the Alveolar- Arterial Gradient in Hypoxemia: An Underutilized and Underappreciated Clinical Tool

The Alveolar-arterial gradient, commonly known as the A-a gradient, measures the difference in the oxygen concentration in the alveoli and the arteries across the capillary membrane in the lung. In an ideal system, the A-a gradient would be zero because there would be perfect equilibrium as oxygen diffuses and equalizes across the alveolar and arterial sides of the capillary membrane. However, there is a physiologic A-a gradient because of the differences in perfusion and ventilation in the apical and basilar regions of the lungs. Because this relationship exists, the changes in the A-a gradient have clinical utility in guiding the differential diagnosis of hypoxemia

A Guide to Point of Care Ultrasound Lung and IVC Examination of a Volume Overloaded Patient

A patient presents with dyspnea, hypoxia, and lower extremity edema. Their history is notable for recent high salt intake and non-compliance with diuretics, and their lungs have rales bilaterally. Clinically, we can diagnose a heart failure exacerbation with pulmonary edema. However, we often rely on X-ray and computed tomography (CT) imaging to support the clinical diagnosis and explore the etiology of the hypoxia and dyspnea to narrow the differential. Ultrasound is an effective modality for identifying pulmonary edema and pleural effusions while at the same time ruling out other etiologies such as pneumonia and pneumothorax. With bedside point of care ultrasound (POCUS), there is no radiation risk and no delay in obtaining imaging. A systematic review and meta-analysis study by Maw et al. published in 2019 found that lung ultrasound diagnosis of pulmonary edema in the setting of clinical suspicion for acute decompensated heart failure had a pooled sensitivity of 0.88 and specificity of 0.9, which is superior to X-ray imaging which demonstrated a pooled sensitivity of 0.73 and a pooled specificity of 0.9.

A Guide to Point of Care Ultrasound Evaluation of Pneumonia

A patient presenting with fever, hypoxia, productive cough, and leukocytosis can be diagnosed with pneumonia without any imaging findings. However, we often rely on X-ray and computed tomography (CT) imaging to support the clinical diagnosis. Ultrasound is an effective imaging modality for identifying pneumonia without delay and radiation risks.1,2 A meta-analysis by Ye et al. in 2015 found that ultrasound diagnosis of pneumonia had a pooled sensitivity of 0.95 and a pooled specificity of 0.9, which is superior to X-ray imaging which had a pooled sensitivity of 0.77 and a similar pooled specificity of 0.9.3 This study used CT imaging as a gold standard for comparison

A Guide to Point of Care Ultrasound Examination of a Pericardial Effusion

A patient presents with pleuritic chest pain, dyspnea, and a recent viral illness. They have no prior cardiac or pulmonary history. Their X-ray on admission demonstrates no pulmonary findings and an enlarged cardiac silhouette, and their EKG is low voltage with electrical alternans. Ultrasound is an effective modality for identifying pericardial effusion and cardiac tamponade while at the same time evaluating for other causes, such as heart failure. Often patients with symptomatic pericardial ef fusion present with non-specific symptoms. While a “formal” transthoracic echocardiogram remains the gold standard for diagnosis, a bedside point of care ultrasound (POCUS) cardiac evaluation can significantly decrease the time to diagnosis and trigger an order for an urgent “formal” echocardiogram.1 A retrospective study by Hanson and Chan in 2021 found that POCUS led to an expedited average time to diagnosis of 5.9 hours compared to \u3e12 hours with other imaging. Those with a symptomatic pericardial effusion identified by POCUS had a significantly decreased time to treatment; time to pericardiocentesis of 28.1 hours compared to \u3e 48 hours with other diagnostic modalities.

A Guide to Point of Care Ultrasound Examination of Acute Decompensated Heart Failure

A patient presents with dyspnea on exertion, orthopnea, and lower extremity edema. They have a prior history of coronary artery disease and reported episodes of chest pain three months ago. They did not seek medical evaluation at the time and have had no chest pain recently. In this setting, there is a high clinical suspicion of heart failure with concern for ischemic heart disease. The gold standard for diagnosis of heart failure is a formal transthoracic echocardiogram. Bedside point of care ultrasound (POCUS) is a tool that can provide essential information without delay in diagnosis

CdSe quantum dot (QD) and molecular dye hybrid sensitizers for TiO2 mesoporous solar cells: working together with a common hole carrier of cobalt complexes

Redox couples based on cobalt complexes were found to be effective in regenerating both inorganic CdSe quantum dot-and organic dye-sensitizers. The hybrid sensitizer composed of CdSe QD and ruthenium sensitizer (Z907Na) dye showed a maximum power conversion efficiency of 4.76% on using cobalt(o-phen)(3)(2+/3+) as a common redox mediator.close202

Continuous in situ soil nitrate sensors: The importance of high‐resolution measurements across time and a comparison with salt extraction‐based methods

Soil NO3– affects microbial processes, plant productivity, and environmental N losses. However, the ability to measure soil NO3– is limited by labor‐intensive sampling and laboratory analyses. Hence, temporal variation in soil solution NO3– concentration is poorly understood. We evaluated a new potentiometric sensor that continuously measures soil solution NO3– concentration with unprecedented specificity due to a novel membrane that serves as a barrier to interfering anions. First, we compared sensor and salt extraction‐based measurements of soil NO3– in well‐controlled laboratory conditions. Second, using 60 d of in situ soil NO3– measurements every 10 s, we quantified temporal variation and the effect of sampling frequency on field estimations of mean daily NO3– concentration both within and across days. In the laboratory, sensors measured soil NO3– concentration without significant difference from theoretical adjusted soil NO3– concentration or conventional salt extraction‐based methods. In the field, the sensors demonstrated no within‐day pattern in soil NO3– concentration, although individual measurements within a day differed by as much as 20% from the daily mean. Across days, when soil solution NO3– was dynamic (early spring) and sampling frequency was \u3e5 d, estimates of mean daily NO3– concentration were \u3e20% from the actual mean daily concentration. In situ soil sensors offer potential to improve fundamental and applied sciences. However, in most situations, sensors will measure soil properties in a different manner than conventional salt‐extract soil sampling‐based approaches. Research will be required to interpret sensor measurements and optimize sensor deployment

Robotic Wireless Sensor Networks

In this chapter, we present a literature survey of an emerging, cutting-edge, and multi-disciplinary field of research at the intersection of Robotics and Wireless Sensor Networks (WSN) which we refer to as Robotic Wireless Sensor Networks (RWSN). We define a RWSN as an autonomous networked multi-robot system that aims to achieve certain sensing goals while meeting and maintaining certain communication performance requirements, through cooperative control, learning and adaptation. While both of the component areas, i.e., Robotics and WSN, are very well-known and well-explored, there exist a whole set of new opportunities and research directions at the intersection of these two fields which are relatively or even completely unexplored. One such example would be the use of a set of robotic routers to set up a temporary communication path between a sender and a receiver that uses the controlled mobility to the advantage of packet routing. We find that there exist only a limited number of articles to be directly categorized as RWSN related works whereas there exist a range of articles in the robotics and the WSN literature that are also relevant to this new field of research. To connect the dots, we first identify the core problems and research trends related to RWSN such as connectivity, localization, routing, and robust flow of information. Next, we classify the existing research on RWSN as well as the relevant state-of-the-arts from robotics and WSN community according to the problems and trends identified in the first step. Lastly, we analyze what is missing in the existing literature, and identify topics that require more research attention in the future

AXL targeting restores PD-1 blockade sensitivity of STK11/LKB1 mutant NSCLC through expansion of TCF1+ CD8 T cells

Mutations in STK11/LKB1 in non-small cell lung cancer (NSCLC) are associated with poor patient responses to immune checkpoint blockade (ICB), and introduction of a Stk11/Lkb1 (L) mutation into murine lung adenocarcinomas driven by mutant Kras and Trp53 loss (KP) resulted in an ICB refractory syngeneic KPL tumor. Mechanistically this occurred because KPL mutant NSCLCs lacked TCF1-expressing CD8 T cells, a phenotype recapitulated in human STK11/LKB1 mutant NSCLCs. Systemic inhibition of Axl results in increased type I interferon secretion from dendritic cells that expanded tumor-associated TCF1+PD-1+CD8 T cells, restoring therapeutic response to PD-1 ICB in KPL tumors. This was observed in syngeneic immunocompetent mouse models and in humanized mice bearing STK11/LKB1 mutant NSCLC human tumor xenografts. NSCLC-affected individuals with identified STK11/LKB1 mutations receiving bemcentinib and pembrolizumab demonstrated objective clinical response to combination therapy. We conclude that AXL is a critical targetable driver of immune suppression in STK11/LKB1 mutant NSCLC.publishedVersio