AbbreviationsCOVID-19 (coronavirus disease 2019), CT (computed tomography), CXR (chest radiograph), RT-PCR (reverse transcriptase-polymerase chain reaction), ICU (intensive care unit), WBC (white blood cell), LDH (lactate dehydrogenase), CRP (C-reactive protein) SummaryVaccinated patients with COVID-19 breakthrough infections showed fewer chest CT findings of pneumonia compared to unvaccinated patients. Key Results1. Of 761 hospitalized patients with COVID-19 disease and chest radiographs, 77% (587/761) were in unvaccinated patients while breakthrough infection in fully vaccinated subjects occurred in 6.2% (47/761) patients.2. The initial chest x-ray showed no pneumonia in 75% of fully vaccinated patients with breakthrough infection and 63% of unvaccinated patients (p=.37).3. In 412 patients with chest CT during hospitalization, a CT showed no pneumonia in 59% of fully vaccinated patients with breakthrough infection and 27% of unvaccinated patients (p=.01).

BackgroundGadolinium-based contrast agents are widely used as a contrast agent for magnetic resonance imaging. Since gadolinium ions are toxic, many chelators are developed to bind gadolinium ions to prevent free gadolinium-associated disease. However, many reports indicated that linear chelator-based contrast agents are associated with nephrogenic systemic fibrosis (NSF) in patients with low kidney function. Therefore, the demand for stable macrocyclic chelator-based contrast agent is now increasing.Method1,4,7,10-Tetraazacyclododecane-1,4,7,10-tetraacetate (DOTA) was conjugated to lactobionic acid (LBA) through DCC-NHS coupling reaction. Gd3+ (gadolinium ion) was chelated to 1,4,7,10-Tetraazacyclododecane-1,4,7,10-tetraacetate-lactobionic acid (DOTA-LAE) and free Gd3+ was removed using a cation exchange column. In vitro cytotoxicity of contrast agent towards normal cells was measured using MTT assay. For in vivo MR imaging, contrast agents were intravenously injected to tumor-bearing mice and imaged by a MR imaging scanner.ResultsThis new macrocyclic gadolinium-based contrast agent showed enhanced in vitro paramagnetic properties compared to Gadovist. In addition, Gd-DOTA-LAE showed a 29% increased contrast enhancement of tumor tissue compared to normal tissue within 20 min past IV injection.ConclusionsWe developed a new macrocyclic T1-weighted MR contrast agent. This new contrast agent offers various opportunities for cancer detection and diagnosis.

BackgroundMagnetic resonance imaging is one of the diagnostic tools that uses magnetic particles as contrast agents. It is noninvasive methodology which provides excellent spatial resolution. Although magnetic resonance imaging offers great temporal and spatial resolution and rapid in vivo images acquisition, it is less sensitive than other methodologies for small tissue lesions, molecular activity or cellular activities. Thus, there is a desire to develop contrast agents with higher efficiency. Contrast agents are known to shorten both T1 and T2. Gadolinium based contrast agents are examples of T1 agents and iron oxide contrast agents are examples of T2 agents. In order to develop high relaxivity agents, gadolinium or iron oxide-based contrast agents can be synthesized via conjugation with targeting ligands or functional moiety for specific interaction and achieve accumulation of contrast agents at disease sites.Main bodyThis review discusses the principles of magnetic resonance imaging and recent efforts focused on specificity of contrast agents on specific organs such as liver, blood, lymph nodes, atherosclerotic plaque, and tumor. Furthermore, we will discuss the combination of theranostic such as contrast agent and drug, contrast agent and thermal therapy, contrast agent and photodynamic therapy, and neutron capture therapy, which can provide for cancer diagnosis and therapeutics.ConclusionThese applications of magnetic resonance contrast agents demonstrate the usefulness of theranostic agents for diagnosis and treatment.

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In current nanoscale semiconductor fabrications, high dielectric materials and ultrathin multilayers have been selected to improve the performance of the devices. Thus, interface effects between films and the quantification of surface information are becoming key issues for determining the performance of the semiconductor devices. In this paper, we developed an easy, accurate, and nondestructive diagnosis to investigate the interface effect of hafnium oxide ultrathin films. A roughness scaling method that artificially modified silicon surfaces with a maximum peak-to-valley roughness range of a few nanometers was introduced to examine the effect on the underlayer roughness. The critical overlayer roughness was be defined by the transition of RMS roughness which was 0.18 nm for the 3 nm thick hafnium oxide film. Subsequently, for the inline diagnostic application of semiconductor fabrication, the roughness of a mass produced hafnium film was investigated. Finally, we confirmed that the result was below the threshold set by our critical roughness. The RMS roughness of the mass produced hafnium oxide film was 0.11 nm at a 500 nm field of view. Therefore, we expect that the quantified and standardized critical roughness managements will contribute to improvement of the production yield.

Background Few reports have evaluated the effect of the SARS-CoV-2 variant and vaccination on the clinical and imaging features of COVID-19. Purpose To evaluate and compare the effect of vaccination and variant prevalence on the clinical and imaging features of infections by the SARS-CoV-2. Materials and Methods Consecutive adults hospitalized for confirmed COVID-19 at three centers (two academic medical centers and one community hospital) and registered in a nationwide open data repository for COVID-19 between August 2021 and March 2022 were retrospectively included. All patients had available chest radiographs or CT. Patients were divided into two groups according to predominant variant type over the study period. Differences between clinical and imaging features were analyzed using Pearson χ 2 test, Fisher exact test, or the independent t-test. Multivariable logistic regression analyses were used to evaluate the effect of variant predominance and vaccination status on imaging features of pneumonia and clinical severity. Results Of the 2180 patients (mean age, 57 years ± 21, 1171 women), 1022 patients (46%) were treated during the Delta variant predominant period and 1158 (54%) during the Omicron period. The Omicron variant prevalence was associated with lower pneumonia severity based on CT scores (OR, 0.71 [95% CI: 0.51, 0.99; P = .04]) and lower clinical severity based on ICU admission or in-hospital death (OR 0.43, 95% CI: 0.24, 0.77, P = .004) than the Delta variant prevalence. Vaccination was associated with the lowest odds of severe pneumonia based on CT scores (OR 0.05, 95% CI:0.03, 0.13, P < .001) and clinical severity based on ICU admission or in-hospital death (OR 0.15, 95% CI: 0.07, 0.31, P < .001) relative to no vaccination. Conclusion The SARS-CoV-2 Omicron variant prevalence and vaccination were associated with better clinical outcomes and lower severe pneumonia risk relative to Delta variant prevalence.