Structural Characterization of Canine Minute Virus, Rat and Porcine Bocavirus.

Bocaparvovirus is an expansive genus of the Parvovirinae, with a wide range of vertebrate hosts. This study investigates Canine minute virus (CnMV), Rat bocavirus (RBoV), and Porcine bocavirus 1 (PBoV1). Both CnMV and PBoV1 have been found in gastrointestinal infections in their respective hosts, with CnMV responsible for spontaneous abortions in dogs, while PBoV has been associated with encephalomyelitis in piglets. The pathogenicity of the recently identified RBoV is currently unknown. To initiate the characterization of these viruses, their capsids structures were determined by cryo-electron microscopy at resolutions ranging from 2.3 to 2.7 Å. Compared to other parvoviruses, the CnMV, PBoV1, and RBoV capsids showed conserved features, such as the channel at the fivefold symmetry axis. However, major differences were observed at the two- and threefold axes. While CnMV displays prominent threefold protrusions, the same region is more recessed in PBoV1 and RBoV. Furthermore, the typical twofold axis depression of parvoviral capsids is absent in CnMV or very small in PBoV and RBoV. These capsid structures extend the structural portfolio for the Bocaparvovirus genus and will allow future characterization of these pathogens on a molecular level. This is important, as no antivirals or vaccines exist for these viruses.

Exfoliation procedure-dependent optical properties of solution deposited MoS2 films.

The development of high-precision large-area optical coatings and devices comprising low-dimensional materials hinges on scalable solution-based manufacturability with control over exfoliation procedure-dependent effects. As such, it is critical to understand the influence of technique-induced transition metal dichalcogenide (TMDC) optical properties that impact the design, performance, and integration of advanced optical coatings and devices. Here, we examine the optical properties of semiconducting MoS2 films from the exfoliation formulations of four prominent approaches: solvent-mediated exfoliation, chemical exfoliation with phase reconversion, redox exfoliation, and native redox exfoliation. The resulting MoS2 films exhibit distinct refractive indices (n), extinction coefficients (k), dielectric functions (ε1 and ε2), and absorption coefficients (α). For example, a large index contrast of Δn ≈ 2.3 is observed. These exfoliation procedures and related chemistries produce different exfoliated flake dimensions, chemical impurities, carrier doping, and lattice strain that influence the resulting optical properties. First-principles calculations further confirm the impact of lattice defects and doping characteristics on MoS2 optical properties. Overall, incomplete phase reconfiguration (from 1T to mixed crystalline 2H and amorphous phases), lattice vacancies, intraflake strain, and Mo oxidation largely contribute to the observed differences in the reported MoS2 optical properties. These findings highlight the need for controlled technique-induced effects as well as the opportunity for continued development of, and improvement to, liquid phase exfoliation methodologies. Such chemical and processing-induced effects present compelling routes to engineer exfoliated TMDC optical properties toward the development of next-generation high-performance mirrors, narrow bandpass filters, and wavelength-tailored absorbers.

Clinical Outcomes of Eyes With Diabetic Macular Edema Switched From Aflibercept to Ranibizumab Therapy.

BACKGROUND AND OBJECTIVE: In 2018, cases of inflammation were reported after intravitreal aflibercept (IVA), which resulted in switches to intravitreal ranibizumab (IVR). The authors' purpose was to evaluate outcomes after switching from IVA to IVR in diabetic macular edema (DME). PATIENTS AND METHODS: Retrospective cohort study. Eyes switched from IVA to IVR for treating DME were included. Data were gathered from three visits before to three visits post-switch. Outcome measures included central subfoveal thickness (CFT) and Snellen visual acuity (VA). RESULTS: There was a statistically significant increase in CFT at the first visit (325 µm ± 234 µm; P = .006) compared to the switch visit, but no difference later visits (268 µm ± 103 µm; P = .32; 284 µm ± 118 µm; P = .11; n = 54). There was no statistically significant change in mean logarithm of the minimum angle of resolution VA between the switch and later visits (0.43 ± 0.38, P = .95; 0.38 ± 0.30, P = .12; 0.41 ± 0.37, P = .69). CONCLUSIONS: The authors observed transient worsening of macular edema in eyes treated for DME when switched from aflibercept to ranibizumab. [Ophthalmic Surg Lasers Imaging Retina. 2020;51:691-697.].

Usefulness of Integrating Heart Failure Risk Factors Into Impairment of Global Longitudinal Strain to Predict Anthracycline-Related Cardiac Dysfunction.

The prediction of cancer therapeutics-related cardiac dysfunction (CTRCD) is an essential aspect of care for individuals who receive potentially cardiotoxic oncologic treatments. Certain clinical risk factors have been described for incident CTRCD, and measurement of left ventricular (LV) longitudinal strain by speckle tracking 2-dimensional echocardiography (2DE) is the best-validated myocardial mechanical imaging assessment to detect subtle changes in LV function during cancer treatment. However, the direct integration of clinical and imaging risk factors to predict CTRCD has not yet been extensively examined. This was a retrospective study of 183 women with breast cancer aged 50.9 ± 10.8 years who received treatment with anthracyclines (doxorubicin dose of 422 ± 69 mg/m2, with 41.2% of subjects also receiving trastuzumab) and underwent 2DE at clinically determined intervals. CTRCD was diagnosed when LV ejection fraction dropped ≥10% to a subnormal (<53%) value by 2DE. Left ventricular global longitudinal strain (LV-GLS) was assessed offline. The risk prediction tool based only on clinical factors previously described by Ezaz et al was applied to our cohort and accurately stratified these subjects into low-, intermediate-, and high-risk groups, with incident CTRCD in 7.4%, 26.9%, and 54.6%, respectively (chi-square = 20.7, p <0.0001). We developed novel multivariate models to predict CTRCD using (1) demographic variables only (c = 0.8674), (2) echocardiographic (peak LV-GLS) variables only (c = 0.8440), or (3) a combination of demographic and echocardiographic variables, with the combined model exhibiting superior receiver-operating characteristics (c = 0.9629). In conclusion, estimation of CTRCD risk should integrate all available data, including both clinical variables and an imaging assessment.

Radiation exposure of cardiac sonographers working in an academic noninvasive cardiovascular imaging laboratory.

BACKGROUND AND AIM: Exposure to workplace radiation among cardiac sonographers has been felt to be low, and patient-related sources have been considered negligible. Sonographers may be exposed to radiation from patient emitted sources as well as external sources in interventional laboratories. This study quantified radiation exposure to cardiac sonographers. METHODS: Cardiac sonographers, vascular imaging technologists, exercise physiologists, noninvasive nursing staff, and CT/MRI technologists were provided body dosimeter badges. Sonographers were provided dosimeter rings for their scanning hands. Radiation exposure was quantified from the dosimeter data, reported in millirems (mrem) for deep, eye, and shallow exposure, as well as shallow exposure data from the rings. Data were prospectively collected for 63 employees over a 12-month period and retrospectively analyzed. RESULTS: The mean annual deep body exposure in sonographers was 8.2 mrem/year, shallow exposure 9.8 mrem/year, eye exposure 8.5 mrem/year, and ring exposure 207 mrem/year. There was a significant difference between body and ring exposure (P = .0002). When comparing exposure data between the vascular imaging technologists, CT/MRI technologists, noninvasive nursing staff, and the cardiac sonographers, there were no statistical differences (P > .23). Exercise physiologists had significantly higher exposure compared to sonographers (P < .03). CONCLUSION: This single-center experience demonstrates that, while exposure is low, cardiac sonographers are exposed to workplace radiation, most likely from patient emitted radiation. The finding that radiation exposure from rings exceeded body exposure supports this conclusion. Continued education and assessment of work flow practices should be employed to minimize staff radiation exposure.

Defining characteristics of early adopters of multimodality cardiovascular imaging.

BACKGROUND: The prototype for the cardiovascular imager has evolved to necessitate some degree of competency in multimodality imaging (MMI)-defined as expertise in at least 2 of the 4 modalities (echocardiography [ECHO], nuclear cardiology [NUC], cardiovascular computed tomography [CCT], and magnetic resonance [CMR]). Uncertainty exists about the effects of this change. METHODS: Information detailing the current totals of board-certified practitioners in MMI was collected and organized into groups of 1, 2, and 3 modalities. A randomized stratified sample of names was obtained to identify a representative 10% of each group. Those names were cross-referenced online with information from state medical boards, faculty rosters of academic medical centers, and physician tracking Websites. RESULTS: There are a total of 2209 board-certified MMI practitioners (2 modalities = 1885, 3 modalities = 324) and 6450 single-modality imagers in the United States. Of those sampled, 98.9% were cardiologists, 31.3% were at academic medical centers and mean time from medical school graduation was 17.75 years. MMI practitioners were more likely to have graduated from medical school more recently (P < 0.0001) and to be trained cardiologists (P = 0.003) than those who practice in a single modality. There was a nonsignificant trend toward MMI being practiced more commonly in an academic setting (P = 0.38). CONCLUSION: Board-certified specialists in MMI tend to be younger cardiologists than those engaged in single-modality cardiac imaging. There are few advanced (3 modality) MMI practitioners in the United States.

Cardiovascular magnetic resonance in wet beriberi.

The clinical presentation of beriberi can be quite varied. In the extreme form, profound cardiovascular involvement leads to circulatory collapse and death. This case report is of a 72 year-old male who was admitted to the Neurology inpatient ward with progressive bilateral lower extremity weakness and parasthesia. He subsequently developed pulmonary edema and high output cardiac failure requiring intubation and blood pressure support. With the constellation of peripheral neuropathy, encephalopathy, ophthalmoplegia, unexplained heart failure, and lactic acidosis, thiamine deficiency was suspected. He was empirically initiated on thiamine replacement therapy and his thiamine level pre-therapy was found to be 23 nmol/L (Normal: 80-150 nmol/L), consistent with the diagnosis of beriberi. Cardiovascular magnetic resonance (CMR) showed severe left ventricular systolic dysfunction, markedly increased myocardial T2, and minimal late gadolinium enhancement (LGE). After 5 days of daily 100 mg IV thiamine and supportive care, the hypotension resolved and the patient was extubated and was released from the hospital 3 weeks later. Our case shows via CMR profound myocardial edema associated with wet beriberi.