Joining Two Switches in One Nano-Object: Photoacidity and Photoisomerization in Electrostatic Self-Assembly.

Multi-switchable supramolecular nano-objects that respond to irradiation of different wavelengths with changes in size and shape have been built from two different water-soluble molecular switches, joined by attachment to the same polyelectrolyte. Accordingly, two wavelength-specific reactions, namely the excited-state proton dissociation of a photoacid and the cis-trans isomerization of an azo dye, are combined in one supramolecular nano-object that is stable in aqueous solution. The concept has potential in the fields of sensors, molecular motors, and transport.

A New (Digital) Era in Medical Journalism: Leveraging Social Media and Other Online Tools to Increase Reach and Engagement.

Social media is a popular communication and marketing tool in modern society, with the power to reach and engage large audiences. Many members of the medical and radiology communities have embraced social media platforms, particularly X (formerly known as Twitter), as an efficient and economic means for performing patient outreach, disseminating research and educational materials, building networks, and promoting diversity. Editors of medical journals with a clear vision and relevant expertise can leverage social media and other digital tools to advance the journal's mission, further their interests, and directly benefit journal authors and readers. For editors, social media offers a means to increase article visibility and downloads, expand awareness of volunteer opportunities, and use metrics and other feedback to inform future initiatives. Authors benefit from broader dissemination of their work, which aids establishment of a national or international reputation. Readers can receive high-quality high-yield content in a digestible format directly on their devices while actively engaging with journal editors and authors in the online community. The authors highlight the multifaceted benefits of social media engagement and digital tool implementation in the context of medical journalism and summarize the activities of the RadioGraphics Social Media and Digital Innovation Team. By enumerating the social media activities of RadioGraphics and describing the underlying rationale for each activity, the authors present a blueprint for other medical journals considering similar initiatives. ©RSNA, 2023.

Unique approaches for testicular shielding during total-body irradiation for pediatric patients.

Total-body irradiation (TBI) has been used as a part of the conditioning regimen for patients undergoing hematopoietic stem cell transplantation for certain nonmalignant conditions such as sickle cell disease. Although effective, TBI can cause lasting side effects for pediatric patients. One of these potential side effects includes oligospermia or even permanent azoospermia. Although many investigators have studied ways to shield the testicles during the TBI for nonmalignant conditions, there is no set standard. We describe the technical aspects of effective techniques to shield the testicles of male pediatric patients undergoing TBI. We verified that our techniques reduced the testicular dose by approximately 80%-85% of the TBI prescription dose in four male pediatric patients, keeping the dose well below the documented doses that can cause permanent infertility and hypogonadism.

Hippocampal Volumes in Amnestic and Non-Amnestic Mild Cognitive Impairment Types Using Two Common Methods of MCI Classification.

OBJECTIVES: Mild cognitive impairment (MCI) types may have distinct neuropathological substrates with hippocampal atrophy particularly common in amnestic MCI (aMCI). However, depending on the MCI classification criteria applied to the sample (e.g., number of abnormal test scores considered or thresholds for impairment), volumetric findings between MCI types may change. Additionally, despite increased clinical use, no prior research has examined volumetric differences in MCI types using the automated volumetric software, Neuroreader™. METHODS: The present study separately applied the Petersen/Winblad and Jak/Bondi MCI criteria to a clinical sample of older adults (N = 82) who underwent neuropsychological testing and brain MRI. Volumetric data were analyzed using Neuroreader™ and hippocampal volumes were compared between aMCI and non-amnestic MCI (naMCI). RESULTS: T-tests revealed that regardless of MCI classification criteria, hippocampal volume z-scores were significantly lower in aMCI compared to naMCI (p's < .05), and hippocampal volume z-scores significantly differed from 0 (Neuroreader™ normative mean) in the aMCI group only (p's < .05). Additionally, significant, positive correlations were found between measures of delayed recall and hippocampal z-scores in aMCI using either MCI classification criteria (p's < .05). CONCLUSIONS: We provide evidence of correlated neuroanatomical changes associated with memory performance for two commonly used neuropsychological MCI classification criteria. Future research should investigate the clinical utility of hippocampal volumes analyzed via Neuroreader™ in MCI.

Anatomy and Diseases of the Greater Wings of the Sphenoid Bone.

The greater wings of the sphenoid bone (GWS) comprise the components of the sphenoid bone that make up most of the posterior orbital wall and form the anterior and medial parts of the floor of the middle cranial fossa. Many important skull base foramina, which transmit vital neurovascular structures, are present in these paired wings on either side of the central body of the sphenoid bone. A wide variety of diseases can affect the GWS, ranging from benign osseus lesions to malignant primary and secondary bone abnormalities. The complex three-dimensional curved (winged) shape of the GWS and the wide array of pathologic entities that affect this bone can make it challenging for the radiologist to report the imaging findings accurately, especially in relation to the important skull base foramina. The authors describe a systematic approach to understanding the three-dimensional anatomy of the GWS and review important diseases, with the aid of imaging examples. Useful imaging "pearls" that can help in making specific diagnoses are provided throughout the article. ©RSNA, 2022.

Solvent Induced Helix Folding of Defined Indolenine Squaraine Oligomers.

A protecting group strategy was employed to synthesise a series of indolenine squaraine dye oligomers up to the nonamer. The longer oligomers show a distinct solvent dependence of the absorption spectra, that is, either a strong blue shift or a strong red shift of the lowest energy bands in the near infrared spectral region. This behaviour is explained by exciton coupling theory as being due to H- or J-type coupling of transition moments. The H-type coupling is a consequence of a helix folding in solvents with a small Hansen dispersity index. DOSY NMR, small angle neutron scattering (SANS), quantum chemical and force field calculations agree upon a helix structure with an unusually large pitch and open voids that are filled with solvent molecules, thereby forming a kind of clathrate. The thermodynamic parameters of the folding process were determined by temperature dependent optical absorption spectra.

The development and efficacy of a mobile phone application to improve medication adherence for persons with epilepsy in limited resource settings: A preliminary study.

OBJECTIVE: Persons with epilepsy (PWE), especially those with limited education backgrounds from developing countries, are challenged by complicated medication regimens, debilitating seizures, and stigmatization in their daily life. Consequently, it is difficult for physicians to ensure medication adherence. This study validates a novel mobile application which was hypothesized to increase medication adherence and self-management skills in PWE. Created by medical professionals, the application included behavioral and educational components and was built to be easy-to-understand for those of socio-economically disadvantaged backgrounds. METHODS: This was a parallel, two-armed randomized controlled trial in which a total of 96 participants were enrolled from a Neurology Outpatient Department into a control standard care group and a mobile application group that used the smartphone application (app) in addition to the standard medical treatment. The app was intuitive and easy to understand for those coming from a socio-economically disadvantaged background. Medication adherence and self-efficacy were assessed with the Morisky Green and Levine Scale (MGLS) and the Epilepsy Self Efficacy Scale (ESES). Patients were reassessed 12 weeks later. Change in seizure frequency following administration of the application was a secondary outcome. RESULTS: In an intent-to-treat analysis, the mobile application interventional group showed over a 60% increase in the proportion of medication adherence (P < 0.0001). The mean self-efficacy score for the mobile application group was increased from 269.5 to 289.75 (P < 0.0001). The control group showed no statistically significant increases in either the proportion adherent or mean self-efficacy scores. SIGNIFICANCE: This study demonstrated the statistically significant performance of a mobile application in improving medication adherence and self-management skills in Indian persons with epilepsy.

A Novel Block Imaging Technique Using Nine Artificial Intelligence Models for COVID-19 Disease Classification, Characterization and Severity Measurement in Lung Computed Tomography Scans on an Italian Cohort.

Computer Tomography (CT) is currently being adapted for visualization of COVID-19 lung damage. Manual classification and characterization of COVID-19 may be biased depending on the expert's opinion. Artificial Intelligence has recently penetrated COVID-19, especially deep learning paradigms. There are nine kinds of classification systems in this study, namely one deep learning-based CNN, five kinds of transfer learning (TL) systems namely VGG16, DenseNet121, DenseNet169, DenseNet201 and MobileNet, three kinds of machine-learning (ML) systems, namely artificial neural network (ANN), decision tree (DT), and random forest (RF) that have been designed for classification of COVID-19 segmented CT lung against Controls. Three kinds of characterization systems were developed namely (a) Block imaging for COVID-19 severity index (CSI); (b) Bispectrum analysis; and (c) Block Entropy. A cohort of Italian patients with 30 controls (990 slices) and 30 COVID-19 patients (705 slices) was used to test the performance of three types of classifiers. Using K10 protocol (90% training and 10% testing), the best accuracy and AUC was for DCNN and RF pairs were 99.41 ± 5.12%, 0.991 (p < 0.0001), and 99.41 ± 0.62%, 0.988 (p < 0.0001), respectively, followed by other ML and TL classifiers. We show that diagnostics odds ratio (DOR) was higher for DL compared to ML, and both, Bispecturm and Block Entropy shows higher values for COVID-19 patients. CSI shows an association with Ground Glass Opacities (0.9146, p < 0.0001). Our hypothesis holds true that deep learning shows superior performance compared to machine learning models. Block imaging is a powerful novel approach for pinpointing COVID-19 severity and is clinically validated.

Longitudinal Reproducibility of MR Perfusion Using 3D Pseudocontinuous Arterial Spin Labeling With Hadamard-Encoded Multiple Postlabeling Delays.

BACKGROUND: Arterial spin labeling (ASL) can be confounded by varying arterial transit times (ATT) across the brain and with disease. Hadamard encoding schemes can be applied to 3D pseudocontinuous ASL (pCASL) to acquire ASL data with multiple postlabeling delays (PLDs) to estimate ATT and then correct cerebral blood flow (CBF). PURPOSE: To assess the longitudinal reproducibility of 3D pCASL with Hadamard-encoded multiple PLDs. STUDY TYPE: Prospective, longitudinal. POPULATION: Fifty-two healthy, right-handed male subjects who underwent imaging at four timepoints over 45 days. FIELD STRENGTH/SEQUENCE: A Hadamard-encoded 3D pCASL sequence was acquired at 3.0T with seven PLDs from 1.0-3.7 sec. ASSESSMENT: ATT and corrected CBF (cCBF) were computed. Conventional uncorrected CBF (unCBF) was also estimated. Within- and between-subject coefficient of variation (wCV and bCV, respectively) and intraclass correlation coefficient (ICC) were evaluated across four time intervals: 7, 14, 30, and 45 days, in gray matter and 17 independent regions of interest (ROIs). A power analysis was also conducted. STATISTICAL TESTS: A repeated-measures analysis of variance (ANOVA) was used to compare ATT, cCBF, and unCBF across the four scan sessions. A paired two-sample t-test was used to compare cCBF and unCBF. Pearson's correlation was used to examine the relationship between the cCBF and unCBF difference and ATT. Power calculations were completed using both the cCBF and unCBF variances. RESULTS: ATT showed the lowest wCV and bCV (3.3-4.4% and 6.0-6.3%, respectively) compared to both cCBF (10.5-11.7% and 20.6-22.2%, respectively) and unCBF (12.0-13.6% and 22.7-23.7%, respectively). wCV and bCV were lower for cCBF vs. unCBF. A significant difference between cCBF and unCBF was found in most regions (P = 5.5 × 10-5 -3.8 × 10-4 in gray matter) that was highly correlated with ATT (R2 = 0.79-0.86). A power analysis yielded acceptable power at feasible sample sizes using cCBF. DATA CONCLUSION: ATT and ATT-corrected CBF were longitudinally stable, indicating that ATT and CBF changes can be reliably evaluated with Hadamard-encoded 3D pCASL with multiple PLDs. LEVEL OF EVIDENCE: 1 Technical Efficacy Stage: 2 J. Magn. Reson. Imaging 2020;51:1846-1853.

Memory Performance and Quantitative Neuroimaging Software in Mild Cognitive Impairment: A Concurrent Validity Study.

OBJECTIVE: This study examined the relationship between patient performance on multiple memory measures and regional brain volumes using an FDA-cleared quantitative volumetric analysis program - Neuroreader™. METHOD: Ninety-two patients diagnosed with mild cognitive impairment (MCI) by a clinical neuropsychologist completed cognitive evaluations and underwent MR Neuroreader™ within 1 year of testing. Select brain regions were correlated with three widely used memory tests. Regression analyses were conducted to determine if using more than one memory measures would better predict hippocampal z-scores and to explore the added value of recognition memory to prediction models. RESULTS: Memory performances were most strongly correlated with hippocampal volumes than other brain regions. After controlling for encoding/Immediate Recall standard scores, statistically significant correlations emerged between Delayed Recall and hippocampal volumes (rs ranging from .348 to .490). Regression analysis revealed that evaluating memory performance across multiple memory measures is a better predictor of hippocampal volume than individual memory performances. Recognition memory did not add further predictive utility to regression analyses. CONCLUSIONS: This study provides support for use of MR Neuroreader™ hippocampal volumes as a clinically informative biomarker associated with memory performance, which is a critical diagnostic feature of MCI phenotype.

Aminoglycoside impregnated cement spacer precipitating acute kidney injury requiring hemodialysis.

The current standard of care for prosthetic joint infection includes two-stage arthroplasty, with antibiotic-impregnated cement spacers (ACS) utilized between the stages. We report a 75-year-old woman with previously normal renal function, who developed acute kidney injury (AKI) secondary to biopsy-proven acute tubular necrosis and acute interstitial nephritis after ACS placement containing tobramycin and vancomycin. Peak tobramycin level measured 25.3 mcg/mL, the highest value reported in the literature after ACS placement. Intermittent hemodialysis was initiated with subsequent full recovery of renal function. This paper reviews the published literature regarding the accumulation, toxicity and removal dynamics of aminoglycoside (AG) antibiotics and vancomycin in renal patients. Obtaining serum AG level should be strongly considered in patients experiencing AKI after ACS. Renal replacement therapy may assist in reducing toxic AG levels.

Craniovertebral junction evaluation by computed tomography in asymptomatic individuals in the Indian population.

BACKGROUND: The available literature on the anatomy and imaging of the craniovertebral junction (CVJ) focusses on the osteometric indices described for the detection of abnormal relationships between the components of CVJ. However, a knowledge of the normal osteometry of this region in the Indian population is critically important for the operating surgeon as it may influence the surgical technique as well as the choice, size and configurations of the implants. It is also important to determine whether critical differences exist between the osteometric data of Indians and the rest of the world for this part of the anatomy. Accordingly, the present study is an attempt to quantitate the osteometric indices for the anatomically normal CVJ in Indian subjects. MATERIALS AND METHODS: We retrospectively studied the imaging data of 49 consecutive adult patients (31 males, 18 females) who underwent a computed tomographic (CT) angiogram for suspected vascular conditions unrelated to the craniovertebral junction. Several parameters related to the atlanto-dental relationship, foramen magnum, atlas and axis vertebrae were recorded, including the dimensions of the commonly instrumented bony regions and also the indices related to the CVJ bony relationships. The data was also compared between the two genders, statistically through the Student's t-test using the statistical program "R". RESULTS: No patient had an atlanto dens interval >2.5 mm. The mean distance of the odontoid tip from the McRae line in this series was 5.11 mm and no patient had the odontoid tip above the McRae line. Female subjects had significantly smaller diameters of C1 lateral masses and odontoid screw trajectory length when compared to males. Additionally, in the Indian population, the length range of odontoid screw trajectory and the thickness of the narrowest part of the C2 pedicles was smaller with respect to similar data from other geographical regions. However, the rest of the parameters resembled the data from studies conducted on populations with other ethnicities. CONCLUSION: The osteometric parameters of the CVJ in the Indian population are largely similar to those described globally. However, there are some important differences too which can influence the design of surgical implants suited to the Indian population.

Primary Management of Squamous Cell Carcinoma of the Anal Canal: A 30-year Community Hospital Experience.

We reviewed outcomes of 41 patients treated with curative-intent radiotherapy for anal canal carcinoma at a community hospital between 1985 and 2015. Twenty-six (63%) presented with stage I or II disease while 15 (37%) had stage III. Thirty-seven received definitive chemoradiation and 4 radiotherapy alone. Thirteen (31.7%) received ≤59.4Gy. Thirty-two (78%) were treated with 3-dimensional conformal radiotherapy while 9 (22%) received intensity-modulated radiotherapy. At 5 years, local control, regional control, freedom from distant metastasis, cause-specific survival, and overall survival were 80%, 98%, 88%, 77%, and 51%. Of those who received >59.4Gy, local control and overall survival were not improved.

Bedside Tunneled Dialysis Catheter Removal-A Lesson Learned From Nephrology Trainees.

Semi-permanent dual-lumen tunneled (or tunneled-cuffed) hemodialysis catheters (TDC) are increasingly utilized during renal replacement therapy, while awaiting permanent access maturation or renal recovery. Although there is a wealth of literature focused on placement, infection prevention, and maintenance of catheter patency, circumstances and indications for TDC removal are less well understood. Timely removal of these catheters is an important management decision, with the length of TDC duration representing the largest cumulative risk factor for catheter-associated blood stream infections. Waiting for assistance from surgical or radiological services-which may not be available in all hospitals-may result in delays in services and potential harm to the patients. Imparting and maintaining procedural skills to remove infected TDC may be very valuable for training programs in clinical nephrology. In this article the current literature on bedside TDC removal, including potential anticipated complications during removal, are reviewed. To date, the authors have documented successful implementation of bedside TDC removal in training programs from two different settings, including both in- and outpatients and with trainee involvement. In summary, training general nephrologists for bedside TDC removal will afford immediate removal of infected hardware in ill patients and avoid potential delays in outpatient setting.

Imaging correlates of neural control of ocular movements.

The purpose of oculomotor movements is maintenance of clear images on the retina. Beyond this oversimplification, it requires several different types of ocular movements and reflexes to focus objects of interest to the fovea-the only portion of retina capable of sharp and clear vision. The different movements and reflexes that execute this task are the saccades, smooth pursuit movements, fixation, accommodation, and the optokinetic and vestibulo-ocular reflexes. Many different centres in the cerebrum, cerebellum, brainstem and thalami, control these movements via different pathways. At the outset, these mechanisms appear dauntingly complex to a radiologist. However, only a little effort could make it possible to understand these neural controls and empower the reading session. The following review on ocular movements and their neural control will enable radiologists and clinicians to correlate lesions with clinical deficits effectively without being swamped by exhaustive detail. Key Points • Knowledge of cortical and subcortical areas controlling ocular movements is important. • Understanding of neural control of ocular movements makes a good foundation. • Awareness of anatomic areas controlling ocular movements helps in clinico-radiologic correlation.

Multiple Sclerosis Part 1: Essentials and the McDonald Criteria.

Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system (CNS) characterized by relapsing-remitting or progressive neurologic symptoms and focal white matter lesions. The hallmark of the disease is the dissemination of CNS lesions in space and time, which is defined by the McDonald criteria. MRI is an essential diagnostic and prognostic biomarker for MS which can evaluate the entire CNS. MS mimics must be excluded before a diagnosis of MS is made.

An Ogden hyperelastic 3D micromechanical model to depict Poynting effect in brain white matter.

Shear and torsional load on soft solids such as brain white matter purportedly exhibits the Poynting Effect. It is a typical nonlinear phenomenon associated with soft materials whereby they tend to elongate (positive Poynting effect) or contract (negative Poynting effect) in a direction perpendicular to the shearing or twisting plane. In this research, a novel 3D micromechanical Finite Element Model (FEM) has been formulated to describe the Poynting effect in bi-phasic modeled brain white matter (BWM) representative volume element (RVE) with axons tracts embedded in surrounding extracellular matrix (ECM) for simulating brain matter's response to pure and simple shear. In the presented BWM 3D FEM, nonlinear Ogden hyper-elastic material model is deployed to interpret axons and ECM material phases. The modeled bi-phasic RVEs have axons tied to the surrounding ECM. In this proof-of-concept (POC) FEM, three simple shear loading configurations and a pure shear case were analyzed. Root mean square deviation (RMSD) was calculated for stress and deformation response plots to understand the effect of axon-ECM orientations and loading conditions on the degree of Poynting behavior. Variations in normal stresses (S11, S22, or S33) perpendicular to the shear plane underscored the significance of axonal fiber-matrix interactions. From the simulated ensemble of cases, a transitional dominance trend was noticed, as simple sheared axons showed pronounced Poynting behavior, but shear deformation build-up in the purely sheared brain model exhibited the highest Poynting behavior at higher strain % limits. At lower strain limits, simple shear imparted across and perpendicular to axonal tract directions emerged as the dominant Poynting effect configurations. At high strains, the stress-strain% plots manifested mild strain stiffening effects and bending stresses in purely sheared axons, substantiated the strong non-linearity in brain tissues' response.

Photoacid-macroion assemblies: how photo-excitation switches the size of nano-objects.

Electrostatic self-assembly of photoacids with oppositely charged macroions yields supramolecular nano-objects in aqueous solutions, whose size is controlled through light irradiation. Nano-assemblies are formed due to electrostatic attractions and mutual hydrogen bonding of the photoacids. Irradiation with UV light leads to the deprotonation of the photoacid and, consequently, a change in particle size. Overall, the hydrodynamic radii of the well-defined photoacid-macroion nano-objects lie between 130 and 370 nm. For a set of photoacids, we determine the acidity constants in the ground and excited state, discuss the sizes of photoacid-macroion nano-objects (by dynamic and static light scattering), their composition and the particle shapes (by small-angle neutron scattering), and relate their charge characteristics to size, structure and shape. We investigate the association thermodynamics and relate nanoscale structures to thermodynamics and, in turn, thermodynamics to molecular features, particularly the ionization energy of the photoacid hydroxyl group proton. Structure-directing effects completely differ from those for previously investigated systems, with hydrogen bonding and entropic effects playing a major role herein. This combined approach allows developing a comprehensive understanding of assembly formation and photo-response, anchored in molecular parameters (pKa, ionization energy, substituent group location), charge characteristics, and the association enthalpy and entropy. This fundamental understanding again paves the way for tailoring application solutions with novel photoresponsive materials.

Emerging roles of SnoRNAs in the pathogenesis and treatment of autoimmune disorders.

SnoRNAs (small non-coding RNAs) have recently gained prominence in autoimmune diseases, revealing their crucial role in modulating the immune response and contributing to disease pathogenesis. Initially known for their involvement in ribosomal RNA processing and modification, molecular biology and genomics advancements have uncovered their broader impact on cellular function, especially in autoimmune disorders. Autoimmune diseases represent conditions characterized by the immune system's erroneous attacks on self-tissues, encompassing disorders like systemic lupus erythematosus, rheumatoid arthritis, and multiple sclerosis. The complex etiology of these conditions involves a delicate interplay of genetic and environmental factors. Emerging evidence suggests that snoRNAs initially recognized for their housekeeping roles, extend their influence on immune regulation through diverse mechanisms. SnoRNAs have been implicated in epigenetic modification, directly affecting the gene expression profiles of immune cells. Their ability to guide site-specific changes on ribosomal RNAs and other non-coding RNAs can significantly influence the translation of proteins involved in immune response pathways. Moreover, snoRNAs interact with key immune-related proteins, modulating their functions and subsequently impacting immune cell development, activation, and tolerance. Dysregulation of snoRNA expression has been observed in various autoimmune diseases, underscoring their potential as biomarkers for disease diagnosis, prognosis, and therapeutic targets. Manipulating snoRNA expression or activity is a promising therapeutic intervention avenue, offering the potential for personalized treatment strategies in autoimmune diseases. However, there remains a need for comprehensive research efforts to elucidate the precise molecular mechanisms underlying snoRNA-mediated immune modulation. Further investigations in this domain are essential to unravel the potential of snoRNAs in autoimmune disorders.