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Takotsubo cardiomyopathy (TC) is an acute but reversible non-ischemic heart failure syndrome. It is characterized by a transient form of ventricular dysfunction typically manifesting as basal hyperkinesis with hypokinesia and ballooning of left ventricle mid-cavity and apex. Imaging helps in both diagnosis and follow up. Echocardiogram is the first-line modality to assess the typical contractile dysfunction in suspected patients with catheter angiography showing normal coronary arteries. Cardiac MRI is currently the modality of choice for the non-invasive initial assessment of TC and for follow up imaging. The current review focusses on historical background of TC, its pathophysiology, diagnostic work up and differential diagnosis and provides multimodality imaging work up of TC including role of echocardiogram, invasive catheterization, nuclear imaging, cardiac computed tomography and cardiac MRI including basic and advanced MRI sequences. • Takotsubo cardiomyopathy (TC) is reversible syndrome mimicking acute coronary syndrome. • TC is typically characterized by basal hyperkinesis and apical akinesis. • Echocardiography and catheter angiography are often first line modality. • Cardiac MRI is modality of choice for the non-invasive initial assessment. • Cardiac MRI provides comprehensive evaluation for initial diagnosis and follow up. [ABSTRACT FROM AUTHOR]

The use of computed tomography angiography (CTA) for the evaluation of peripheral vascular trauma has become increasingly prevalent in the past decade with the development of multidetector CT (MDCT) and multiple studies subsequently demonstrating high sensitivity, specificity, and diagnostic accuracy when compared with conventional angiography. Additional benefits of MDCT include the ability to rapidly acquire the images, perform multiplanar and 3D reconstructions, and assess the adjacent soft tissues and bones. Rapid intravenous injection of iodinated contrast material is required for optimal arterial enhancement. CTA manifestations of an arterial injury may be direct, and include active contrast extravasation, pseudoaneurysm, arteriovenous fistula (AVF), intimal injury, dissection, or occlusion. There are also indirect signs which have a high association with vascular injury, and should raise suspicion, when present. Pitfalls related to image acquisition or patient factors can be mitigated with appropriate planning and post-processing techniques. [ABSTRACT FROM AUTHOR]

Objectives: Computed tomography pulmonary angiogram (CTPA) is one of the most commonly ordered and frequently overused tests. The purpose of this study was to evaluate the mean radiation dose to patients getting CTPA and to identify factors that are associated with higher dose. Material and Methods: This institutionally approved retrospective study included all patients who had a CTPA to rule out acute pulmonary embolism between 2016 and 2018 in a tertiary care center. Patient data (age, sex, body mass index [BMI], and patient location), CT scanner type, image reconstruction methodology, and radiation dose parameters (dose-length product [DLP]) were recorded. Effective dose estimates were obtained by multiplying DLP by conversion coefficient (0.014 mSv·mGy-1·cm-1). Multivariate logistic regression analysis was performed to determine the factors affecting the radiation dose. Results: There were 2342 patients (1099 men and 1243 women) with a mean age of 58.1 years (range 0.2-104.4 years) and BMI of 31.3 kg/m² (range 12-91.5 kg/m²). The mean effective radiation dose was 5.512 mSv (median - 4.27 mSv; range 0.1-43.0 mSv). Patient factors, including BMI >25 kg/m², male sex, age >18 years, and intensive care unit (ICU) location, were associated with significantly higher dose (P < 0.05). CT scanning using third generation dual-source scanner with model-based iterative reconstruction (IR) had significantly lower dose (mean: 4.90 mSv) versus single-source (64-slice) scanner with filtered back projection (mean: 9.29 mSv, P < 0.001). Conclusion: Patients with high BMI and ICU referrals are associated with high CT radiation dose. They are most likely to benefit by scanning on newer generation scanner using advance model-based IR techniques. [ABSTRACT FROM AUTHOR]

This is a proof-of-concept study to create a four-dimensional (4-D) cine model of the heart and visualize it in virtual reality by using freely available open-source software and inexpensive hardware. Four-dimensional cine models allow for real-time visualization of cardiac structures during processes such as complex congenital heart disease. Such models can be used for patient and trainee education, and potentially for surgical planning. Currently, 3-D printed models are more commonly used, but they are static, showing only one selected phase of the cardiac cycle. Second, they are limited by the selection of clipping planes before printing. Four-dimensional segmentation and virtual reality visualization overcome these limitations. Currently, most of the work in virtual/augmented reality models involves the segmentation of one cardiac phase or the use of expensive software for multiphase segmentation. In this study, we show an approach for multiphase cardiac segmentation as well as its display using free open-source software and relatively inexpensive hardware. [ABSTRACT FROM AUTHOR]

COVID-19 pneumonia is a newly recognized lung infection. Initially, CT imaging was demonstrated to be one of the most sensitive tests for the detection of infection. Currently, with broader availability of polymerase chain reaction for disease diagnosis, CT is mainly used for the identification of complications and other defined clinical indications in hospitalized patients. Nonetheless, radiologists are interpreting lung imaging in unsuspected patients as well as in suspected patients with imaging obtained to rule out other relevant clinical indications. The knowledge of pathological findings is also crucial for imagers to better interpret various imaging findings. Identification of the imaging findings that are commonly seen with the disease is important to diagnose and suggest confirmatory testing in unsuspected cases. Proper precautionary measures will be important in such unsuspected patients to prevent further spread. In addition to understanding the imaging findings for the diagnosis of the disease, it is important to understand the growing set of tools provided by artificial intelligence. The goal of this review is to highlight common imaging findings using illustrative examples, describe the evolution of disease over time, discuss differences in imaging appearance of adult and pediatric patients and review the available literature on quantitative CT for COVID-19. We briefly address the known pathological findings of the COVID-19 lung disease that may help better understand the imaging appearance, and we provide a demonstration of novel display methodologies and artificial intelligence applications serving to support clinical observations. [ABSTRACT FROM AUTHOR]

The aortic pathologies are well recognized on imaging. However, conventionally cardiac and proximal aortic abnormalities were only seen on dedicated cardiac or aortic studies due to need for ECG gating. Advances in CT technology have allowed motionless imaging of the chest and abdomen, leading to an increased visualization of cardiac and aortic root diseases on non-ECG-gated imaging. The advances are mostly driven by high pitch due to faster gantry rotation and table speed. The high-pitch scans are being increasingly used for variety of clinical indications because the images are free of motion artifact (both breathing and pulsation) as well as decreased radiation dose. Recognition of aortic root pathologies may be challenging due to lack of familiarity of radiologists with disease spectrum and their imaging appearance. It is important to recognize some of these conditions as early diagnosis and intervention is key to improving prognosis. We present a comprehensive review of proximal aortic anatomy, pathologies commonly seen at the aortic root, and their imaging appearances to familiarize radiologists with the diseases of this location. [ABSTRACT FROM AUTHOR]

A cervical aortic arch is a rare vascular malformation that is characterized as a high positioned aortic arch, above the clavicle. The knowledge of its branching pattern is essential to characterize the entity further accurately. Noninvasive cross-sectional imaging, including computed tomography angiography or magnetic resonance angiography, is the imaging methods of choice. Due to highly complex anatomy, three-dimensional (3D) images help in providing improved anatomical visualization. Virtual reality is a relatively new computer-generated simulation technique that allows the interactive display of high-resolution models using a wearable headset and interactive controllers. We describe a rare form of a cervical arch and briefly discuss the latest methods of improved visualization using 3D virtual reality displays and smartphones. [ABSTRACT FROM AUTHOR]

The stomach may be involved by a myriad of pathologies ranging from benign aetiologies like inflammation to malignant aetiologies like carcinoma or lymphoma. Multidetector CT (MDCT) of the stomach is the first-line imaging for patients with suspected gastric pathologies. Conventionally, CT imaging had the advantage of simultaneous detection of the mural and extramural disease extent, but advances in MDCT have allowed mucosal assessment by virtual endoscopy (VE). Also, better three-dimensional (3D) post-processing techniques have enabled more robust and accurate pre-operative planning in patients undergoing gastrectomy and even predict the response to surgery for patients undergoing laparoscopic sleeve gastrectomy for weight loss. The ability of CT to obtain stomach volume (for bariatric surgery patients) and 3D VE images depends on various patient and protocol factors that are important for a radiologist to understand. We review the appropriate CT imaging protocol in the patients with suspected gastric pathologies and highlight the imaging pearls of various gastric pathologies on CT and VE. [ABSTRACT FROM AUTHOR]

Traumatic basal ganglia hemorrhage (TBGH) refers to development of intraparenchymal bleed with in the basal ganglia, internal capsule, or thalamus. Though the reported incidence of TBGH is approximately 3% of all closed-head injuries, bilateral TBGH is much rarer, with only 13 cases reported to date. We present two additional cases of bilateral TBGH posttrauma, along with a review of the existing literature. [ABSTRACT FROM AUTHOR]

Acute aortic pathologies include traumatic and non-traumatic life-threatening emergencies of the aorta. Since the clinical manifestation of these entities can be non-specific and may overlap with other conditions presenting with chest pain, non-invasive imaging plays a crucial role in their rapid and accurate evaluation. The early diagnosis and accurate radiological assessment of acute aortic diseases is essential for improved clinical outcomes. Multidetector CT is the imaging modality of choice for evaluation of acute aortic diseases with MRI playing more of a problem-solving role. The management can be medical, endovascular or surgical depending upon pathology, and imaging remains an indispensable management-guiding tool. It is important to understand the pathogenesis, natural history, and imaging principles of acute aortic diseases for appropriate use of advanced imaging modalities. This understanding helps to formulate a more appropriate management and follow-up plan for optimised care of these patients. Imaging reporting pearls for day-to-day radiology as well as treatment options based on latest multidisciplinary guidelines are discussed. With newer techniques of image acquisition and processing, we are hopeful that imaging would further help in predicting aortic disease progression and assessing the haemodynamic parameters based on which decisions on management can be made. [ABSTRACT FROM AUTHOR]

The main focus of this work is to introduce a single free-breathing and ungated imaging protocol to jointly estimate cardiac function and myocardial T 1 maps. We reconstruct a time series of images corresponding to k-space data from a free-breathing and ungated inversion recovery gradient echo sequence using a manifold algorithm. We model each image in the time series as a non-linear function of three variables: cardiac and respiratory phases and inversion time. The non-linear function is realized using a convolutional neural networks (CNN) generator, while the CNN parameters, as well as the phase information, are estimated from the measured k-t space data. We use a dense conditional auto-encoder to estimate the cardiac and respiratory phases from the central multi-channel k-space samples acquired at each frame. The latent vectors of the auto-encoder are constrained to be bandlimited functions with appropriate frequency bands, which enables the disentanglement of the latent vectors into cardiac and respiratory phases, even when the data are acquired with intermittent inversion pulses. Once the phases are estimated, we pose the image recovery as the learning of the parameters of the CNN generator from the measured k-t space data. The learned CNN generator is used to generate synthetic data on demand by feeding it with appropriate latent vectors. The proposed approach capitalizes on the synergies between cine MRI and T 1 mapping to reduce the scan time and improve patient comfort. The framework also enables the generation of synthetic breath-held cine movies with different inversion contrasts, which improves the visualization of the myocardium. In addition, the approach also enables the estimation of the T 1 maps with specific phases, which is challenging with breath-held approaches. [ABSTRACT FROM AUTHOR]

Current deep learning-based manifold learning algorithms such as the variational autoencoder (VAE) require fully sampled data to learn the probability density of real-world datasets. However, fully sampled data is often unavailable in a variety of problems, including the recovery of dynamic and high-resolution magnetic resonance imaging (MRI). We introduce a novel variational approach to learn a manifold from undersampled data. The VAE uses a decoder fed by latent vectors, drawn from a conditional density estimated from the fully sampled images using an encoder. Since fully sampled images are not available in our setting, we approximate the conditional density of the latent vectors by a parametric model whose parameters are estimated from the undersampled measurements using back-propagation. We use the framework for the joint alignment and recovery of multi-slice free breathing and ungated cardiac MRI data from highly undersampled measurements. Experimental results demonstrate the utility of the proposed scheme in dynamic imaging alignment and reconstructions. [ABSTRACT FROM AUTHOR]

Metallic nanostructures now play an important role in many applications. In particular, for the emerging fields of plasmonics and nanophotonics, the ability to engineer metals on nanometric scales allows the development of new devices and the study of exciting physics. This review focuses on top-down nanofabrication techniques for engineering metallic nanostructures, along with computational and experimental characterization techniques. A variety of current and emerging applications are also covered. [ABSTRACT FROM AUTHOR]

We compare the dielectric functions of silver interfaces obtained via thermal evaporation with those obtained with template stripping. Ellipsometry measurements show that the smoother template-stripped surfaces exhibit effective dielectric functions with a more negative real component and a smaller imaginary component, implying higher conductivity and less energy loss, respectively. These results agree with the relation between dielectric function and surface roughness derived from combining the effective-medium model and the Drude-Lorentz model. The improvement in the effective dielectric properties shows that metallic films prepared via template stripping can be favorable for applications in electronics, nanophotonics, and plasmonics. [ABSTRACT FROM AUTHOR]

Surface plasmons are electromagnetic waves that can exist at metal interfaces because of coupling between light and free electrons. Restricted to travel along the interface, these waves can be channeled, concentrated, or otherwise manipulated by surface patterning. However, because surface roughness and other inhomogeneities have so far limited surface-plasmon propagation in real plasmonic devices, simple high-throughput methods are needed to fabricate high-quality patterned metals. We combined template stripping with precisely patterned silicon substrates to obtain ultrasmooth pure metal films with grooves, bumps, pyramids, ridges, and holes. Measured surface-plasmon-propagation lengths on the resulting surfaces approach theoretical values for perfectly flat films. With the use of our method, we demonstrated structures that exhibit Raman scattering enhancements above 107 for sensing applications and multilayer films for optical metamaterials. [ABSTRACT FROM AUTHOR]

Bilinear models such as low-rank and dictionary methods, which decompose dynamic data to spatial and temporal factor matrices are powerful and memory-efficient tools for the recovery of dynamic MRI data. Current bilinear methods rely on sparsity and energy compaction priors on the factor matrices to regularize the recovery. Motivated by deep image prior, we introduce a novel bilinear model, whose factor matrices are generated using convolutional neural networks (CNNs). The CNN parameters, and equivalently the factors, are learned from the undersampled data of the specific subject. Unlike current unrolled deep learning methods that require the storage of all the time frames in the dataset, the proposed approach only requires the storage of the factors or compressed representation; this approach allows the direct use of this scheme to large-scale dynamic applications, including free breathing cardiac MRI considered in this work. To reduce the run time and to improve performance, we initialize the CNN parameters using existing factor methods. We use sparsity regularization of the network parameters to minimize the overfitting of the network to measurement noise. Our experiments on free-breathing and ungated cardiac cine data acquired using a navigated golden-angle gradient-echo radial sequence show the ability of our method to provide reduced spatial blurring as compared to classical bilinear methods as well as a recent unsupervised deep-learning approach. [ABSTRACT FROM AUTHOR]

Coronary cameral fistula is a rare entity and is characterized by an abnormal communication between coronary artery and a cardiac chamber. It is usually congenital and asymptomatic in majority of patients. If symptomatic the patients usually present in childhood. We present a case of 45-year-old male who presented with anginal chest pain and dyspnea on exertion for last 1 year. His exercise treadmill test was positive for ischemic changes and ECG-gated contrast enhanced CT was done for further evaluation. CT showed a large right coronary artery to right atrium fistula. It also ruled out any coronary atherosclerosis as reason for chest pain and ischemic symptoms on exercise treadmill test. The fistula was successfully closed by surgery and there was resolution of chest pain and dyspnea. [ABSTRACT FROM AUTHOR]

Extrapleural space (EPS) is a potential space between the outer layer of the parietal pleura and the inner layer of the chest wall and the diaphragm. Many different pathologies including chronic inflammatory conditions, infections, trauma, neoplastic disease (both benign and malignant) as well as many infiltrative disorders can involve the EPS. It is one of the frequently overlooked entity on imaging due to relative lack of understanding of the anatomy and the imaging appearances of the diseases localized to this space. The knowledge of the EPS is essential for the radiologists as the pathologies which involve the EPS may require different treatment approach compared to pleural or parenchymal lung disease. Additionally, the EPS involvement may influence the staging and treatment planning for chest malignancies. In this review, we give an overview of the anatomy and various pathologies involving EPS, utility of different imaging modalities in the evaluation of EPS lesions with emphasis on cross sectional imaging and emerging technologies like spectral CT and its role in recognizing the imaging features which enable specific diagnosis of various pathologies. • This is a comprehensive imaging review of the anatomy and pathologies of Extrapleural space. • Describes various imaging signs with images which help in evaluating the EPS involvement • Describes the role of different imaging modalities in the evaluation of EPS lesions. • Briefly describes the utility of DECT in the evaluation of EPS with examples [ABSTRACT FROM AUTHOR]

We introduce a generative smoothness regularization on manifolds (SToRM) model for the recovery of dynamic image data from highly undersampled measurements. The model assumes that the images in the dataset are non-linear mappings of low-dimensional latent vectors. We use the deep convolutional neural network (CNN) to represent the non-linear transformation. The parameters of the generator as well as the low-dimensional latent vectors are jointly estimated only from the undersampled measurements. This approach is different from traditional CNN approaches that require extensive fully sampled training data. We penalize the norm of the gradients of the non-linear mapping to constrain the manifold to be smooth, while temporal gradients of the latent vectors are penalized to obtain a smoothly varying time-series. The proposed scheme brings in the spatial regularization provided by the convolutional network. The main benefit of the proposed scheme is the improvement in image quality and the orders-of-magnitude reduction in memory demand compared to traditional manifold models. To minimize the computational complexity of the algorithm, we introduce an efficient progressive training-in-time approach and an approximate cost function. These approaches speed up the image reconstructions and offers better reconstruction performance. [ABSTRACT FROM AUTHOR]

This study aims to evaluate the feasibility and utility of virtual reality (VR) for baffle planning in congenital heart disease (CHD), specifically by creating patient-specific 3D heart models and assessing a user-friendly VR interface. Patient-specific 3D heart models were created using high-resolution imaging data and a VR interface was developed for baffle planning. The process of model creation and the VR interface were assessed for their feasibility, usability, and clinical relevance. Collaborative and interactive planning within the VR space were also explored. The study findings demonstrate the feasibility and usefulness of VR in baffle planning for CHD. Patient-specific 3D heart models generated from imaging data provided valuable insights into complex spatial relationships. The developed VR interface allowed clinicians to interact with the models, simulate different baffle configurations, and assess their impact on blood flow. The VR space's collaborative and interactive planning enhanced the baffle planning process. This study highlights the potential of VR as a valuable tool in baffle planning for CHD. The findings demonstrate the feasibility of using patient-specific 3D heart models and a user-friendly VR interface to enhance surgical planning and patient outcomes. Further research and development in this field are warranted to harness the full benefits of VR technology in CHD surgical management. [ABSTRACT FROM AUTHOR]

Tinnitus refers to auditory perception of internal origin. It is a relatively common problem and affects men and women equally. Clinically, it may be divided as pulsatile or non-pulsatile and subjective and objective. Although pulsatile tinnitus (PT) is less common, it is more likely to be associated with underlying vascular tumors, lesions or anomalies. Imaging forms the baseline for evaluation of objective tinnitus, primarily in the form of computed tomography or magnetic resonance imaging. We present a review of common causes of PT, along with emphasis on key imaging findings. [ABSTRACT FROM AUTHOR]

R4869 --> 812.10 --> Multidrug‐resistant (MDR) bacterial infections remain a major threat to public health, despite strides made in antibiotic development in the past century. The rise of MDR infections has demonstrated the dire need for new treatment strategies against infectious disease. MDR bacteria are predicted to cause ten million deaths annually worldwide by 2050, more than all cancers combined, unless significant strides are made in treatment options. While pharmaceutical companies devote years to develop a single drug for a single ailment, bacteria are quick to adapt, and MDR bacterial strains appear within only a couple years of the release of a new antibiotic. Our antibiotic discovery pipelines must accommodate the necessary shift away from traditional small molecule therapies toward more adaptive drugs. Here, we investigate new ways of combating MDR bacteria and apply those methods in vivo to optimize them for clinical use. We present a novel method for the treatment of infections caused by MDR bacteria: antibiotic photoactivated semiconductor nanoparticles called quantum dots (QDs). Photoactivated QDs kill bacteria by producing superoxide, which targets iron clusters in bacterial cells, and additionally have been shown to potentiate the activity of antibiotics against resistant bacteria. We have previously shown that this specific generation of superoxide allows for killing of bacterial cells without causing toxicity to surrounding mammalian cells in vitro. Indium phosphide (InP) QDs injected subcutaneously into mice caused no measured toxicity, measured through body weight, organ histology, and inflammation and oxidative stress markers in serum, to the host animal after six consecutive days of treatment. InP QDs are activated by near‐infrared (NIR) light, which was provided to the injection site using high‐intensity LEDs. We then used InP QDs to treat subcutaneous abscesses of MDR clinical isolate Escherichia coli in mice. As NIR light has high transmittance through skin and tissue, QDs injected under the skin were sufficiently activated for bacterial killing. We observed decreased bacterial count by QD dosages of 2 and 4 μM compared to PBS treatment. A 6000‐fold drop in abscess bacterial viability was observed in mice treated with 4 μM QDs compared to PBS control. This novel approach to treatment of infectious disease could provide necessary alternatives to small‐molecule drugs. The QDs offer a new method of using superoxide to kill bacteria, including bacteria that have developed resistance to small‐molecule drugs. Our QDs could revolutionize last‐resort treatments of burn and wound infections, with the potential to be expanded to other infection types. [ABSTRACT FROM AUTHOR]

Several nanoelectronic techniqueshave been explored to distinguishthe sequence of nucleic acids in DNA macromolecules. Identificationof unique electronic signatures using nanopore conductance, tunnelingspectroscopy, or other nanoelectronic techniques depends on electronicstates of the DNA nucleotides. While several experimental and computationalstudies have focused on interaction of nucleobases with differentsubstrates, the effect of nucleic acid biochemistry on its electronicproperties has been largely unexplored. Here, we present correlatedmeasurements of frontier molecular orbitals and higher-order electronicstates for four DNA nucleobases (adenine, cytosine, thymine, and guanine),and first-principle quantum chemical density functional theoretical(DFT) computations. Using different pH conditions in our experiments,we show that small changes in the biochemical state of these nucleicacids strongly affect the intrinsic electronic structure, measuredusing scanning tunneling spectroscopy (STS). In our experimental measurementsand computations, significant differences were observed between theposition of frontier orbitals and higher-energy states between protonatedand unprotonated nucleic acids, isomers, and different keto–enoltautomer’s formed in these nucleotides, leading to their facileidentification. Furthermore, we show unique “electronic fingerprints”for all nucleotides (A, G, T, C) using STS, with most distinct statesidentified at acidic pH. These results can have important implicationsfor identification of nucleic acid sequences in DNA molecules usinga high-throughput nanoelectronic identification technique. [ABSTRACT FROM AUTHOR]

We demonstrate the design, fabrication and characterization of a near-field plasmonic nanofocusing probe with a hybrid tip-plus-aperture design. By combining template stripping with focused ion beam lithography, a variety of aperture-based near-field probes can be fabricated with high optical performance. In particular, the combination of large transmission through a C-shaped aperture aligned to the sharp apex (<10 nm radius) of a template-stripped metallic pyramid allows the efficient delivery of light-via the C-shaped aperture-while providing a nanometric hotspot determined by the sharpness of the tip itself. [ABSTRACT FROM AUTHOR]

We study the structure of electronic states in individual PbS nanocrystal quantum dots by scanning tunneling spectroscopy (STS) using one-to-two monolayer nanocrystal films treated with 1, 2-ethanedithiols (EDT). Up to six individual valence and conduction band states are resolved for a range of quantum dot sizes. The measured states' energies are in good agreement with calculations using the k∙p four-band envelope function formalism. A comparison of STS and optical absorption spectra indicates that some of the absorption features can only be explained by asymmetric transitions involving the states of different symmetries (e.g., S and P or P and D), which points towards the relaxation of the parity selection rules in these nanostructures. STS measurements also reveal a midgap feature, which is likely similar to one observed in previous charge transport studies of EDT-treated quantum dot films. [ABSTRACT FROM AUTHOR]

Side experiments are performed on radiomics models to improve their reproducibility. We measure the impact of myocardial masks, radiomic side experiments and data augmentation for information transfer (DAFIT) approach to differentiate patients with and without pulmonary hypertension (PH) using cardiac MRI (CMRI) derived radiomics. Feature extraction was performed from the left ventricle (LV) and right ventricle (RV) myocardial masks using CMRI in 82 patients (42 PH and 40 controls). Various side study experiments were evaluated: Original data without and with intraclass correlation (ICC) feature-filtering and DAFIT approach (without and with ICC feature-filtering). Multiple machine learning and feature selection strategies were evaluated. Primary analysis included all PH patients with subgroup analysis including PH patients with preserved LVEF (≥ 50%). For both primary and subgroup analysis, DAFIT approach without feature-filtering was the highest performer (AUC 0.957–0.958). ICC approaches showed poor performance compared to DAFIT approach. The performance of combined LV and RV masks was superior to individual masks alone. There was variation in top performing models across all approaches (AUC 0.862–0.958). DAFIT approach with features from combined LV and RV masks provide superior performance with poor performance of feature filtering approaches. Model performance varies based upon the feature selection and model combination. [ABSTRACT FROM AUTHOR]

We introduce a kernel low-rank algorithm to recover free-breathing and ungated dynamic MRI from spiral acquisitions without explicit k-space navigators. It is often challenging for low-rank methods to recover free-breathing and ungated images from undersampled measurements; extensive cardiac and respiratory motion often results in the Casorati matrix not being sufficiently low-rank. Therefore, we exploit the non-linear structure of the dynamic data, which gives the low-rank kernel matrix. Unlike prior work that rely on navigators to estimate the manifold structure, we propose a kernel low-rank matrix completion method to directly fill in the missing k-space data from variable density spiral acquisitions. We validate the proposed scheme using simulated data and in-vivo data. Our results show that the proposed scheme provides improved reconstructions compared to the classical methods such as low-rank and XD-GRASP. The comparison with breath-held cine data shows that the quantitative metrics agree, whereas the image quality is marginally lower. [ABSTRACT FROM AUTHOR]

The emergence of multidrug‐resistant (MDR) pathogens represents one of the most urgent global public health crises. Light‐activated quantum dots (QDs) are alternative antimicrobials, with efficient transport, low cost, and therapeutic efficacy, and they can act as antibiotic potentiators, with a mechanism of action orthogonal to small‐molecule drugs. Furthermore, light‐activation enhances control over the spatiotemporal release and dose of the therapeutic superoxide radicals from QDs. However, the limited deep‐tissue penetration of visible light needed for QD activation, and concern over trace heavy metals, have prevented further translation. Herein, we report two indium phosphide (InP) QDs that operate in the near‐infrared and deep‐red light window, enabling deeper tissue penetration. These heavy‐metal‐free QDs eliminate MDR pathogenic bacteria, while remaining non‐toxic to host human cells. This work provides a pathway for advancing QD nanotherapeutics to combat MDR superbugs. [ABSTRACT FROM AUTHOR]

The emergence of multidrug‐resistant (MDR) pathogens represents one of the most urgent global public health crises. Light‐activated quantum dots (QDs) are alternative antimicrobials, with efficient transport, low cost, and therapeutic efficacy, and they can act as antibiotic potentiators, with a mechanism of action orthogonal to small‐molecule drugs. Furthermore, light‐activation enhances control over the spatiotemporal release and dose of the therapeutic superoxide radicals from QDs. However, the limited deep‐tissue penetration of visible light needed for QD activation, and concern over trace heavy metals, have prevented further translation. Herein, we report two indium phosphide (InP) QDs that operate in the near‐infrared and deep‐red light window, enabling deeper tissue penetration. These heavy‐metal‐free QDs eliminate MDR pathogenic bacteria, while remaining non‐toxic to host human cells. This work provides a pathway for advancing QD nanotherapeutics to combat MDR superbugs. [ABSTRACT FROM AUTHOR]

Traditional therapeutics and vaccines represent the bedrock of modern medicine, where isolated biochemical molecules or designed proteins have led to success in treating and preventing diseases. However, several adaptive pathogens, such as multidrug-resistant (MDR) superbugs, and rapidly evolving diseases, such as cancer, can evade such molecules very effectively. This poses an important problem since the rapid emergence of multidrug-resistance among microbes is one of the most pressing public health crises of our time—one that could claim more than 10 million lives and 100 trillion dollars annually by 2050. Several non-traditional antibiotics are now being developed that can survive in the face of adaptive drug resistance. One such versatile strategy is redox perturbation using quantum dot (QD) therapeutics. While redox molecules are nominally used by cells for intracellular signaling and other functions, specific generation of such species exogenously, using an electromagnetic stimulus (light, sound, magnetic field), can specifically kill the cells most vulnerable to such species. For example, recently QD therapeutics have shown tremendous promise by specifically generating superoxide intracellularly (using light as a trigger) to selectively eliminate a wide range of MDR pathogens. While the efficacy of such QD therapeutics was shown using in vitro studies, several apparent contradictions exist regarding QD safety and potential for clinical applications. In this review, we outline the design rules for creating specific QD therapies for redox perturbation; summarize the parameters for choosing appropriate materials, size, and capping ligands to ensure their facile clearance; and highlight a potential path forward towards developing this new class of radical QD therapeutics. [ABSTRACT FROM AUTHOR]

Background: The 2016 U.S. Preventive Services Task Force (USPSTF) guidelines for primary prevention statin therapy are more restrictive than the 2013 American College of Cardiology/American Heart Association (ACC/AHA) guidelines. There are important differences in how application of the risk thresholds from these guidelines would impact particular segments of the U.S.Population: Methods: Data from the National Health and Nutrition Examination Survey (2005-14) were used to determine statin eligibility across age, gender, and racial or ethnic group using criteria from the 2013 ACC/AHA and 2016 USPSTF guidelines. Proportions of the study population eligible for statins under the ACC/AHA 5% and 7.5% risk thresholds were compared with those eligible under the 2016 USPSTF 10% guidelines.Results: Of the 5388 study participants, 34% were eligible for statin therapy under the USPSTF guideline compared with 43% under the Class I (7.5%) ACC/AHA treatment threshold and 53% under the Class IIa (5%) ACC/AHA treatment threshold. Moving from the USPSTF 10% threshold to the ACC/AHA 5% threshold increased statin eligibility for males ages 40-59 from 26%-48% (whites), from 19%-43% (Hispanics), and from 33%-74% (blacks). A similar disproportionate but less pronounced effect was seen when different risk thresholds were used for statin eligibility among women ages 40-59 across differing races and ethnicities.Conclusions: In this sample of U.S. adults from the National Health and Nutrition Examination Survey database, full implementation of the higher USPSTF statin treatment threshold could lead to less overall statin use and disproportionately lower statin use among non-Hispanic blacks. [ABSTRACT FROM AUTHOR]

The field of plasmonics can play an important role in developing novel devices for application in energy and healthcare. In this review article, we consider the progress made in design and fabrication of upconverting nanoparticles and metal nanostructures for precisely manipulating light photons, with a wavelength of several hundred nanometers, at nanometer length scales, and describe how to tailor their interactions with molecules and surfaces so that two or more lower energy photons can be used to generate a single higher energy photon in a process called photon upconversion. This review begins by introducing the current state-of-the-art in upconverting nanoparticle synthesis and achievements in color tuning and upconversion enhancement. Through understanding and tailoring physical processes, color tuning and strong upconversion enhancement have been demonstrated by coupling with surface plasmon polariton waves, especially for low intensity or diffuse infrared radiation. Since more than 30% of incident sunlight is not utilized in most photovoltaic cells, this photon upconversion is one of the promising approaches to break the so-called Shockley-Queisser thermodynamic limit for a single junction solar cell. Furthermore, since the low energy photons typically cover the biological window of optical transparency, this approach can also be particularly beneficial for novel biosensing and bioimaging techniques. Taken together, the recent research boosts the applications of photon upconversion using designed metal nanostructures and nanoparticles for green energy, bioimaging, and therapy. [ABSTRACT FROM AUTHOR]

Electronic conduction or charge transport through single molecules depends primarily on molecular structure and anchoring groups and forms the basis for a wide range of studies from molecular electronics to DNA sequencing. Several high-throughput nanoelectronic methods such as mechanical break junctions, nanopores, conductive atomic force microscopy, scanning tunneling break junctions, and static nanoscale electrodes are often used for measuring single-molecule conductance. In these measurements, "smearing" due to conformational changes and other entropic factors leads to large variances in the observed molecular conductance, especially in individual measurements. Here, we show a method for characterizing smear in single-molecule conductance measurements and demonstrate how binning measurements according to smear can significantly enhance the use of individual conductance measurements for molecular recognition. Using quantum point contact measurements on single nucleotides within DNA macromolecules, we demonstrate that the distance over which molecular junctions are maintained is a measure of smear, and the resulting variance in unbiased single measurements depends on this smear parameter. Our ability to identify individual DNA nucleotides at 20X coverage increases from 81.3% accuracy without smear analysis to 93.9% with smear characterization and binning (SCRIB). Furthermore, merely 7 conductance measurements (7X coverage) are needed to achieve 97.8% accuracy for DNA nucleotide recognition when only low molecular smear measurements are used, which represents a significant improvement over contemporary sequencing methods. These results have important implications in a broad range of molecular electronics applications from designing robust molecular switches to nanoelectronic DNA sequencing. [ABSTRACT FROM AUTHOR]

The article focuses on a study regarding potentiating antibiotics in drug-resistant clinical isolates through stimuli-activated superoxide generation. It mentions the increase in concern related to rise of multidrug-resistant (MDR) bacteria to global health by the lack of new antibiotics. It also mentions that activity of antibiotics in clinical MDR isolates of Escherichia coli, Salmonella enterica, and Klebsiella pneumoniae.

We present a novel plasmonic antenna structure, a split-wedge antenna, created by splitting an ultrasharp metallic wedge with a nanogap perpendicular to its apex. The nanogap can tightly confine gap plasmons and boost the local optical field intensity in and around these opposing metallic wedge tips. This three-dimensional split-wedge antenna integrates the key features of nanogaps and sharp tips, i.e., tight field confinement and three-dimensional nanofocusing, respectively, into a single platform. We fabricate split-wedge antennas with gaps that are as small as 1 nm in width at the wafer scale by combining silicon V-grooves with template stripping and atomic layer lithography. Computer simulations show that the field enhancement and confinement are stronger at the tip-gap interface compared to what standalone tips or nanogaps produce, with electric field amplitude enhancement factors exceeding 50 when near-infrared light is focused on the tip-gap geometry. The resulting nanometric hotspot volume is on the order of λ3/106. Experimentally, Raman enhancement factors exceeding 107 are observed from a 2 nm gap split-wedge antenna, demonstrating its potential for sensing and spectroscopy applications. [ABSTRACT FROM AUTHOR]

Background: Pre- and post-operative stomach volumes can be important determinants for effectiveness of laparoscopic sleeve gastrectomy (LSG) in causing weight loss. There is little existing data on the volumes of stomach preoperatively and that excised during LSG. This study was designed to evaluate the change in gastric volume after LSG using multi-detector CT and to correlate it with early post-operative weight loss.Methods: Twenty consecutive patients with BMI ≥ 40 kg/m(2) and medical comorbidities underwent LSG between October 2011 and October 2013 and were analysed prospectively. The pre-operative stomach volume was measured by MDCT done 1-3 days before the surgery. LSG was performed in the standard manner using a 36F bougie. The volume of excised stomach was measured by distending the specimen with saline. MDCT of the upper abdomen was repeated 3 months postoperatively to calculate the gastric sleeve volume. Weight loss and resolution of comorbidities were documented.Results: The mean pre-operative weight of patients was 123.90 kg, and the mean pre-operative stomach volume on MDCT was 1,067 ml. The stomach volume on pre-operative MDCT correlated with pre-operative weight and BMI. The mean volume of the excised stomach was 859 ml when measured by distension of the specimen and 850 ml on MDCT. After 3 months post surgery, the mean volume of gastric sleeve on MDCT was 217 ml, and the mean weight of the patients was 101.22 kg. The volume of the excised stomach calculated by MDCT correlated with the weight loss achieved 3 months postoperatively. However, no correlation was seen between the gastric sleeve volume 3 months postoperatively and weight loss during this period.Conclusions: MDCT is a good method to measure gastric volume before and after LSG. Early post-operative weight loss (3 months) correlates well with the volume of the excised stomach but not with that of the gastric sleeve. [ABSTRACT FROM AUTHOR]

Quantum dot (QD), or semiconductor nanocrystal, thin films are being explored for making solution-processable devices due to their size- and shape-tunable bandgap and discrete higher energy electronic states. While DNA has been extensively used for the self-assembly of nanocrystals, it has not been investigated for the simultaneous conduction of multiple energy charges or excitons via exciton shelves (ES) formed in QD-DNA nano-bioelectronic thin films. Here, we present studies on charge conduction through exciton shelves, which are formed via chemically coupled QDs and DNA, between electronic states of the QDs and the HOMO-LUMO levels in the complementary DNA nucleobases. While several challenges need to be addressed in optimizing the formation of devices using QD-DNA thin films, a higher charge collection efficiency for hot-carriers and our detailed investigations of charge transport mechanism in these thin films highlight their potential for applications in nano-bioelectronic devices and biological transducers. [ABSTRACT FROM AUTHOR]

A rapid increase in anthropogenicemission of greenhouse gases,mainly carbon dioxide, has been a growing cause for concern. Whilephotocatalytic reduction of carbon dioxide (CO2) into solarfuels can provide a solution, lack of insight into energetic pathwaysgoverning photocatalysis has impeded study. Here, we utilize measurementsof electronic density of states (DOS), using scanning tunneling microscopy/spectroscopy(STM/STS), to identify energy levels responsible for photocatalyticreduction of CO2–water in an artificial photosyntheticprocess. We introduce desired states in titanium dioxide (TiO2) nanoparticles, using metal dopants or semiconductor nanocrystals,and the designed catalysts were used for selective reduction of CO2into hydrocarbons, alcohols, and aldehydes. Using a simplemodel, we provide insights into the photophysics governing this multielectronreduction and design a new composite photocatalyst based on overlappingenergy states of TiO2and copper indium sulfide (CIS) nanocrystals.These nanoparticles demonstrate the highest selectivity for ethane(>70%) and a higher efficiency of converting ultraviolet radiationinto fuels (4.3%) using concentrated sunlight (>4 Sun illumination),compared with platinum-doped TiO2nanoparticles (2.1%),and utilize hot electrons to tune the solar fuel from alkanes to aldehydes.These results can have important implications for the developmentof new inexpensive photocatalysts with tuned activity and selectivity. [ABSTRACT FROM AUTHOR]

Upconversion of infrared radiationinto visible light has beeninvestigated for applications in photovoltaics and biological imaging.However, low conversion efficiency due to small absorption cross-sectionfor infrared light (Yb3+), and slow rate of energy transfer(to Er3+states) has prevented application of upconversionphotoluminescence (UPL) for diffuse sunlight or imaging tissue samples.Here, we utilize resonant surface plasmon polaritons (SPP) waves toenhance UPL in doped-lanthanide nanocrystals. Our analysis indicatesthat SPP waves not only enhance the electromagnetic field, and henceweak Purcell effect, but also increase the rate of resonant energytransfer from Yb3+to Er3+ions by 6 fold. Whilewe do observe strong metal mediated quenching (14-fold) of green fluorescenceon flat metal surfaces, the nanostructured metal is resonant in theinfrared and hence enhances the nanocrystal UPL. This strong Coulombic effect on energy transfer can haveimportant implications for other fluorescent and excitonic systemstoo. [ABSTRACT FROM AUTHOR]

The role of reliable, non-invasive imaging-based recognition of pulmonary hypertension (PH) remains a diagnostic challenge. The aim of the current pilot radiomics study was to assess the diagnostic performance of cardiac MRI (cMRI)-based texture features to accurately predict PH. The study involved IRB-approved retrospective analysis of cMRIs from 72 patients (42 PH and 30 healthy controls) for the primary analysis. A subgroup analysis was performed including patients from the PH group with left ventricle ejection fraction ≥ 50%. Texture features were generated from mid-left ventricle myocardium using balanced steady-state free precession (bSSFP) cine short-axis imaging. Forty-five different combinations of classifier models and feature selection techniques were evaluated. Model performance was assessed using receiver operating characteristic curves. A multilayer perceptron model fitting using full feature sets was the best classifier model for both the primary analysis (AUC 0.862, accuracy 78%) and the subgroup analysis (AUC 0.918, accuracy 80%). Model performance demonstrated considerable variation between the models (AUC 0.523–0.918) based on the chosen model–feature selection combination. Cardiac MRI-based radiomics recognition of PH using texture features is feasible, even with preserved left ventricular ejection fractions. [ABSTRACT FROM AUTHOR]

Application of semiconductors in functional optoelectronic devices requires precise control over their doping and formation of junction between p- and n-doped semiconductors. While doped thin films have led to several semiconductor devices, need for high-surface area nanostructured devices for photovoltaic, photoelectrochemical, and photocatalytic applications has been hindered by lack of desired doping in nanostructures. Here, we show titanium-dioxide (TiO2) nanotubes doped with nitrogen (N) and niobium (Nb) as acceptors and donors, respectively, and formation of TiO2 nanotubes p-n homojunction. This TiO2:N/TiO2:Nb homojunction showed distinct diode-like behaviour with rectification ratio of 1115 at ± 5V and exhibited good photoresponse for ultraviolet light (λ = 365 nm) with sensitivity of 0.19 A/W at reverse bias of --5 V. These results can have important implications for development of nanostructured metal-oxide solar-cells, photodiodes, LED's, photocatalysts, and photoelectrochemical devices. [ABSTRACT FROM AUTHOR]

Application of semiconductors in functional optoelectronic devices requires precise control over their doping and formation of junction between p- and n-doped semiconductors. While doped thin films have led to several semiconductor devices, need for high-surface area nanostructured devices for photovoltaic, photoelectrochemical, and photocatalytic applications has been hindered by lack of desired doping in nanostructures. Here, we show titanium-dioxide (TiO2) nanotubes doped with nitrogen (N) and niobium (Nb) as acceptors and donors, respectively, and formation of TiO2 nanotubes p-n homojunction. This TiO2:N/TiO2:Nb homojunction showed distinct diode-like behaviour with rectification ratio of 1115 at ± 5 V and exhibited good photoresponse for ultraviolet light (k = 365 nm) with sensitivity of 0.19 A/W at reverse bias of --5 V. These results can have important implications for development of nanostructured metal-oxide solar-cells, photodiodes, LED's, photocatalysts, and photoelectrochemical devices. [ABSTRACT FROM AUTHOR]