SIMS Analysis of Thin EUV Photoresist Films.

This study reports on the application of secondary ion mass spectrometry (SIMS) for examining thin (20-50 nm) chemically amplified resist films on silicon. SIMS depth profiling was carried out using a gas cluster ion beam to ensure minimal sputter-induced damage to the organic constituents of interest. Specific attention concerned the distribution of the photo acid generator (PAG) molecule within these films, along with the photo-induced fragmentation occurring on extreme ultra-violet photo exposure. Positive secondary ion spectra were collected using a traditional time of flight (ToF)-SIMS and the latest generation IONTOF Hybrid SIMS instrumentation equipped with an OrbitrapTM mass analyzer. Tandem mass spectrometry (MS/MS) capability within the OrbitrapTM secondary ion column was utilized to verify that the C19H17S+ secondary ion did indeed have the molecular structure consistent with the PAG structure. The superior mass resolving power of the OrbitrapTM mass analyzer (∼20× of the ToF mass analyzer) along with improved mass accuracy (a few ppm) proved pivotal in the mass spectral and depth profile analysis of these films. This was not the case for the ToF-SIMS experiments, as the mass spectra, as well as the associated depth profiles, exhibited severe molecular (isobaric) interferences.

Mechanochromic Polymers That Turn Green Upon the Dissociation of Diarylbibenzothiophenonyl: The Missing Piece toward Rainbow Mechanochromism.

Mechanochromic polymers, that is, polymers sensitive to mechanical impact, promise great potential for applications in damage sensors. In particular, radical-type mechanochromic polymers, which produce colored radical species in response to mechanical stress, may enable not only the visualization of mechanical stress, but also its quantitative evaluation by electron paramagnetic resonance analysis. Herein, a radical-type mechanochromic polymer that exhibits a color change from white to green upon dissociation of a diarylbibenzothiophenonyl moiety at the mid-point of a polystyrene chain is presented, and its mechanochromic behavior is examined. Mechanochromic materials that show a variety of colors ("rainbow colors") in response to mechanical stress were prepared by simply mixing radical-type mechanochromic polymers of primary colors.

High levels of plasma neurofilament light chain correlated with brainstem and peripheral nerve damage.

BACKGROUND AND OBJECTIVES: Blood neurofilament light chain (NfL) is a minimally invasive, but highly sensitive biomarker of neurological diseases. However, diseases and neurological damage associated with increased NfL remain unclear. Therefore, the present study investigated factors associated with increased plasma NfL levels in various neurological diseases, focal lesions and pathological processes. METHODS: This was a retrospective cohort study on 410 participants with various neurological diseases and 17 healthy and cognitively unimpaired controls (HCU). Plasma samples were analyzed to measure NfL using ECL immunoassay. The focal lesions were classified as the cerebrum, cerebellum, brainstem, meninges, spinal cord, peripheral nerves, neuromuscular junction, and muscles based on medical records. A multiple regression analysis and receiver operating characteristic curve (ROC) analysis were performed to investigate whether plasma NfL levels predict specific diseases and focal lesions. RESULTS: Plasma NfL levels discriminated between the HCU and all disease groups (area under the curve (AUC), 0.97), with a cut-off value of 63.4 pg/mL. A multiple regression analysis of focal lesions adjusted by pathogenic processes showed that brainstem and peripheral nerve involvement was associated with higher plasma NfL levels. A cut-off value of 53.8 pg/mL of NfL discriminated between the HCU and neurological disease group except for brainstem or peripheral disorders (AUC 0.962), while a cut-off value of 208.0 pg/mL distinguished this group from brainstem or peripheral nervous system disorders (AUC 0.716). DISCUSSION: These results demonstrate that plasma NfL has a potential to be a highly sensitive biomarker for neurological diseases and focal lesions.

A case of chronic progressive autoimmune GFAP astrocytopathy with extensive meningoencephalomyelitis and contrast enhancement on MRI.

•We herein present a case of chronic progressive autoimmune GFAP astrocytopathy.•Symmetrical high-intensity signals on FLAIR were observed in the white matter of the temporal and occipital lobes, lateral cerebral ventricle walls, hippocampus, amygdala, and occipital cortex, with extensive Gd enhancement in radial perivascular lesions and the ependyma in the choroid plexus.•Improvements were achieved by 4 courses of IVMP and one of IVIg.

Clinical Evaluation of Cerebrospinal Fluid p217tau and Neurofilament Light Chain Levels in Patients with Alzheimer's Disease or Other Neurological Diseases.

BACKGROUND: The cerebrospinal fluid (CSF) levels of tau phosphorylated at threonine 217 (p217tau) or 181 (p181tau), and neurofilament light chain (NfL) are definite biomarkers of tauopathy and neurodegeneration in Alzheimer's disease (AD). OBJECTIVE: To validate their utility in excluding other neurological diseases and age-related changes in clinical settings. METHODS: We developed monoclonal antibodies against p217tau and NfL, established novel ELISAs, and analyzed 170 CSF samples from patients with AD or other neurological diseases. RESULTS: In AD, p217tau is a more specific and abundant CSF component than p181tau. However, CSF NfL levels increase age-dependently and to a greater extent in central and peripheral nervous diseases than in AD. CONCLUSIONS: CSF p217tau correlates better with AD neurodegeneration than other tau-related biomarkers and the major phosphorylated tau species. The clinical usage of NfL as a neurodegeneration biomarker in AD requires exclusion of various central and peripheral neurological diseases.

Erythema nodosum-like eruption in coronavirus disease 2019: A case report and literature review of Asian countries.

In the worldwide coronavirus disease 2019 (COVID-19) outbreak, skin manifestations were seen in COVID-19 patients. We report a case in which a COVID-19 patient developed cutaneous lesions that were diagnosed as erythema nodosum-like lesions, which were associated with COVID-19. Nasopharyngeal swab polymerase chain reaction (PCR) confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Histopathologically, extensive inflammation was seen from the epidermis to the fat tissue. An organized thrombus and disrupted inner elastic lamina were seen in an intradermal vessel. These findings suggest septal panniculitis with cutaneous polyarteritis nodosa. The results of PCR using the specimen of skin lesion was negative. The patient took non-steroidal anti-inflammatory drugs and the skin lesion improved in 3 weeks. To characterize the skin eruption, we reviewed previous reports on COVID-19 (confirmed by the detection of SARS-CoV-2 infection) from Asian countries. The type of eruption and timing of its appearance in this case seemed rare. Differences in skin manifestations between Western and Asian countries were noted.

Enhancing Mechanochemical Activation in the Bulk State by Designing Polymer Architectures.

Mechanoresponsive polymers can have attractive functions; however, the relationship between polymer architecture and mechanoresponsiveness in the bulk state is still poorly understood. Here, we designed well-defined linear and star polymers with a mechanophore at the center of each architecture, and investigated the effect of molecular weight and branched structures on mechanoresponsiveness in the solid state. Diarylbibenzofuranone, which can undergo homolytic cleavage of the central C-C bond by mechanical force to form blue-colored radicals, was used as a mechanophore because the cleaved radicals could be evaluated quantitatively using electron paramagnetic resonance measurements. We confirmed that longer polymer chains induce mechanochemical activation more effectively and found that, in the bulk state, the star polymers have higher sensitivity to mechanical stress compared with a linear polymer having similar molecular weight arm segment.