Fabrication of Mie-resonant silicon nanoparticles using laser annealing for surface-enhanced fluorescence spectroscopy.

Silicon nanostructures with unique Mie resonances have garnered considerable attention in the field of nanophotonics. Here, we present a simple and efficient method for the fabrication of silicon (Si) nanoparticle substrates using continuous-wave (CW) laser annealing. The resulting silicon nanoparticles exhibit Mie resonances in the visible region, and their resonant wavelengths can be precisely controlled. Notably, laser-annealed silicon nanoparticle substrates show a 60-fold enhancement in fluorescence. This tunable and fluorescence-enhancing silicon nanoparticle platform has tremendous potential for highly sensitive fluorescence sensing and biomedical imaging applications.

Disease control in patients with non-small cell lung cancer using pemetrexed: Investigating the best treatment strategy.

BACKGROUND: Pemetrexed (PEM) is the primary chemotherapy for non-small cell lung cancer (NSCLC), showing potential for long-term disease stability in certain cases. However, studies examining disease control with PEM therapy are lacking. This study aimed to pinpoint clinical traits in patients with NSCLC responding well to PEM therapy, predict factors influencing disease control, and suggest optimal treatment approaches. METHODS: A retrospective analysis of patients with NSCLC treated with PEM was performed to compare patients who achieved disease control after treatment with those who did not. RESULTS: Of 73 patients, 56 (76.7%) achieved disease control with PEM therapy. In the disease control group, a significantly higher proportion of patients exhibited good performance status (PS) and received PEM doses without reduction after the second cycle. Multivariate analysis identified bevacizumab (Bev) noncompliance, PEM dose reduction, and thyroid transcription factor-1 (TTF-1) negativity as significant independent risk factors for disease progression during PEM therapy. Additionally, overall survival was significantly longer in the disease control group (p < 0.001). CONCLUSIONS: Our findings indicated that maintaining the dose of PEM after the second treatment cycle in patients with NSCLC, along with concurrent use of Bev and the presence of TTF-1 positivity, could enhance disease control rates and extend survival.

Prognostic value of the serum creatinine/cystatin C ratio in patients with chronic obstructive pulmonary disease.

BACKGROUND: Sarcopenia, characterized by skeletal muscle atrophy and physical inactivity, is a manifestation of chronic obstructive pulmonary disease (COPD) and is associated with a poor prognosis. The serum creatinine (Cr)/cystatin C (CysC) ratio has been proposed as a marker of sarcopenia, given its correlation with total skeletal muscle mass, and as a prognostic indicator in COPD. This study aimed to evaluate the usefulness of the serum Cr/CysC ratio as a prognostic determinant in these patients. METHODS: A total of 124 outpatients with COPD were enrolled in this study. Their serum Cr and CysC levels were measured. Survival time analyses were conducted to compare mortality rates between the low and high serum Cr/CysC ratio groups. Multivariate analysis was performed to investigate the association between various factors. RESULTS: Using a serum Cr/CysC cut-off value of 0.885, the mortality rate (per 1000 person-years) for overall mortality was significantly higher in the low serum Cr/CysC ratio group (69.2 versus 28.6; hazard ratio, 2.47; 95% confidence interval, 1.06-5.79; p < 0.05). Similarly, the mortality rate due to respiratory disease was also higher (37.8 versus 8.2; hazard ratio, 4.68; 95% confidence interval, 1.05-20.9; p < 0.05). Multivariate Cox proportional hazards analysis revealed that serum Cr/CysC was an independent risk factor for respiratory disease mortality, regardless of age and airflow limitations. CONCLUSIONS: The serum Cr/CysC ratio could be a valuable clinical parameter for identifying sarcopenia and severe airflow obstruction. The study findings highlight the utility of this ratio as a prognostic predictor in patients with COPD.

Investigation of response of patients with non-small cell lung cancer to docetaxel (plus ramucirumab) therapy in second-line treatment.

BACKGROUND: Several options for second-line therapy are available for patients with advanced non-small cell lung cancer (NSCLC); however, the optimal therapy remains unclear. Docetaxel (DTX) monotherapy and DTX plus ramucirumab (RAM) are the recommended second-line treatment options. However, the efficacy of these treatments remains unsatisfactory. The aim of this study was to identify the clinical characteristics of patients with NSCLC who respond to DTX or DTX + RAM and factors that predict response. METHODS: Patients with NSCLC treated with DTX or DTX + RAM after second-line therapy were retrospectively analyzed. Patients were compared with those who responded or did not respond to the post-treatment efficacy assessment. RESULTS: Of 53 patients, 12 (22.6%) had lung cancer that responded to DTX or DTX + RAM therapy (response group). Multivariate analysis identified the absence of immune checkpoint inhibitors (ICIs) in the immediate prior therapy and a reduced dose of DTX after the second cycle as significant independent risk factors predicting nonresponse to DTX and DTX + RAM therapy in patients with NSCLC. The overall survival was significantly longer in the response group compared to the nonresponse group (p = 0.016). CONCLUSIONS: Our results suggest that DTX and DTX + RAM therapies immediately after treatment with ICI-containing regimens as well as continuation of DTX without dose reduction after the second cycle may increase the response rate and prolong survival in patients with NSCLC.

Label-free visualization of photosynthetic microbial biofilms using mid-infrared photothermal and autofluorescence imaging.

The formation of photosynthetic microbial biofilms comprising multispecies biomolecules, such as extracellular polymeric substances (EPSs), and microbial cells play pivotal roles in maintaining or stimulating their biological functions. Although there are numerous studies on photosynthetic microbial biofilms, the spatial distribution of EPS components that are vital for microbial biofilm formation, such as exopolysaccharides and proteins, is not well understood. Visualization of photosynthetic microbial biofilms requires label-free methods, because labelling EPSs results in structural changes or aggregation. Raman spectroscopy is useful for label-free visualization of biofilm constituents based on chemical contrast. However, interference resulting from the bright autofluorescence of photosynthetic molecules and the low detection efficiency of Raman scattering make visualization a challenge. Herein, we visualized photosynthetic microbial biofilms in a label-free manner using a super-resolution optical infrared absorption imaging technique, called mid-infrared photothermal (MIP) microscopy. By leveraging the advantages of MIP microscopy, such as its sub-micrometer spatial resolution, autofluorescence-free features, and high detection sensitivity, the distribution of cyanobacteria and their extracellular polysaccharides in the biofilm matrix were successfully visualized. This showed that cyanobacterial cells were aligned along acidic/sulfated polysaccharides in the extracellular environment. Furthermore, spectroscopic analyses elucidated that during formation of biofilms, sulfated polysaccharides initially form linear structures followed by entrapment of cyanobacterial cells. The present study provides the foundation for further studies on the formation, structure, and biological functions of microbial biofilms.

Transferrin Receptor-Targeted Iduronate-2-sulfatase Penetrates the Blood-Retinal Barrier and Improves Retinopathy in Mucopolysaccharidosis II Mice.

Mucopolysaccharidoses (MPSs) make up a group of lysosomal storage diseases characterized by the aberrant accumulation of glycosaminoglycans throughout the body. Patients with MPSs display various signs and symptoms, such as retinopathy, which is also observed in patients with MPS II. Unfortunately, retinal disorders in MPS II are resistant to conventional intravenous enzyme-replacement therapy because the blood-retinal barrier (BRB) impedes drug penetration. In this study, we show that a fusion protein, designated pabinafusp alfa, consisting of an antihuman transferrin receptor antibody and iduronate-2-sulfatase (IDS), crosses the BRB and reaches the retina in a murine model of MPS II. We found that retinal function, as assessed by electroretinography (ERG) in MPS II mice, deteriorated with age. Early intervention with repeated intravenous treatment of pabinafusp alfa decreased heparan sulfate deposition in the retina, optic nerve, and visual cortex, thus preserving or even improving the ERG response in MPS II mice. Histological analysis further revealed that pabinafusp alfa mitigated the loss of the photoreceptor layer observed in diseased mice. In contrast, recombinant nonfused IDS failed to reach the retina and hardly affected the retinal disease. These results support the hypothesis that transferrin receptor-targeted IDS can penetrate the BRB, thereby ameliorating retinal dysfunction in MPS II.

Investigation of response factors for monotherapy with immune checkpoint inhibitors in non-small cell lung cancer patients with PD-L1 expression <50.

BACKGROUND: Immune checkpoint inhibitor (ICI) monotherapy is currently approved for the treatment of advanced non-small cell lung cancer (NSCLC) patients with programmed death ligand-1 (PD-L1) expression ≥50%. However, the efficacy of ICI monotherapy in patients with PD-L1 expression <50% has not yet been fully elucidated. The aim of this study was to identify the clinical characteristics of NSCLC patients with PD-L1 expression <50% who respond to single-agent ICIs and factors that predict response. METHODS: Patients with advanced or recurrent NSCLC with a PD-L1 tumor proportion score (TPS) of 50% or less who received new monotherapy with an ICI between July 2012 and December 2022 were retrospectively analyzed. Patients with response were compared with those without response in the post-treatment response assessment. RESULTS: Among the 37 patients, six (16.2%) NSCLC patients in the response group responded to ICI monotherapy and had a significantly lower body mass index (BMI) (p = 0.003). Significantly more patients in the response group developed immune-related adverse events (irAEs) than in the nonresponse group (p < 0.001). Multivariate analysis identified high BMI as a significant independent risk factor predicting nonresponse to ICI monotherapy in NSCLC patients with PD-L1 < 50%. CONCLUSIONS: Among NSCLC patients with PD-L1 < 50%, those with a higher BMI were more likely to be nonresponders to ICI monotherapy. In addition, the group that responded to ICI monotherapy may have been at higher risk of developing irAEs, suggesting that careful follow-up is warranted.

Current prognostic factors of advanced gastric cancer patients treated with chemotherapy: real world data from a Japanese 12 institutions.

BACKGROUND: Understanding the prognostic factors of advanced gastric cancer before starting chemotherapy is important to determine personalized treatment strategies. However, the details of chemotherapy and the prognosis of advanced gastric cancer patients have changed with the time and environment. The aim of this study was to understand the current reality of chemotherapy and to estimate the prognostic factors of advanced gastric cancer patients before starting chemotherapy at multiple centers. This includes specialized cancer hospitals and community hospitals, with the latest data under the Japanese insurance system. METHODS: We evaluated the clinical parameters and treatment details of 1025 patients who received systemic chemotherapy for unresectable advanced gastric cancer from 2012 to 2018 at 12 institutions in Japan. Prognostic factors were analyzed using the Cox proportional hazards regression model. RESULTS: As of April 2021, 953 (93%) patients had died, while 72 (7%) patients survived. The median overall survival and progression-free survival of first-line chemotherapy was 11.8 months (95% confidence interval, 10.8-12.3 months) and 6.3 months (95% confidence interval, 5.9-6.9 months), respectively. Multivariate analysis revealed eight prognostic factors: age < 40 years, performance status ≥2, no gastrectomy, diffuse histological type, albumin <3.6, alkaline phosphatase ≥300, creatinine ≥1.0 and neutrophil-to-lymphocyte ratio > 3.0. Patients using trastuzumab showed better survival than patients without (16.1 months vs. 11.1 months; P = 0.0005). CONCLUSIONS: We identified eight prognostic factors for patients with advanced gastric cancer undergoing Japanese standard chemotherapy. Our results will help clinicians develop treatment strategies for every patient.

Multiplexed fitness profiling by RB-TnSeq elucidates pathways for lignin-related aromatic catabolism in Sphingobium sp. SYK-6.

Bioconversion of lignin-related aromatic compounds relies on robust catabolic pathways in microbes. Sphingobium sp. SYK-6 (SYK-6) is a well-characterized aromatic catabolic organism that has served as a model for microbial lignin conversion, and its utility as a biocatalyst could potentially be further improved by genome-wide metabolic analyses. To this end, we generate a randomly barcoded transposon insertion mutant (RB-TnSeq) library to study gene function in SYK-6. The library is enriched under dozens of enrichment conditions to quantify gene fitness. Several known aromatic catabolic pathways are confirmed, and RB-TnSeq affords additional detail on the genome-wide effects of each enrichment condition. Selected genes are further examined in SYK-6 or Pseudomonas putida KT2440, leading to the identification of new gene functions. The findings from this study further elucidate the metabolism of SYK-6, while also providing targets for future metabolic engineering in this organism or other hosts for the biological valorization of lignin.

Stereoinversion via Alcohol Dehydrogenases Enables Complete Catabolism of ß-1-Type Lignin-Derived Aromatic Isomers.

Sphingobium sp. strain SYK-6 is an efficient aromatic catabolic bacterium that can consume all four stereoisomers of 1,2-diguaiacylpropane-1,3-diol (DGPD), which is a ring-opened ß-1-type dimer. Recently, LdpA-mediated catabolism of erythro-DGPD was reported in SYK-6, but the catabolic pathway for threo-DGPD was as yet unknown. Here, we elucidated the catabolism of threo-DGPD, which proceeds through conversion to erythro-DGPD. When threo-DGPD was incubated with SYK-6, the Cα hydroxy groups of threo-DGPD (DGPD I and II) were initially oxidized to produce the Cα carbonyl form (DGPD-keto I and II). This initial oxidation step is catalyzed by Cα-dehydrogenases, which belong to the short-chain dehydrogenase/reductase (SDR) family and are involved in the catabolism of ß-O-4-type dimers. Analysis of seven candidate genes revealed that NAD+-dependent LigD and LigL are mainly involved in the conversion of DGPD I and II, respectively. Next, we found that DGPD-keto I and II were reduced to erythro-DGPD (DGPD III and IV) in the presence of NADPH. Genes involved in this reduction were sought from Cα-dehydrogenase and ldpA-neighboring SDR genes. The gene products of SLG_12690 (ldpC) and SLG_12640 (ldpB) catalyzed the NADPH-dependent conversion of DGPD-keto I to DGPD III and DGPD-keto II to DGPD IV, respectively. Mutational analysis further indicated that ldpC and ldpB are predominantly involved in the reduction of DGPD-keto. Together, these results demonstrate that SYK-6 harbors a comprehensive catabolic enzyme system to utilize all four ß-1-type stereoisomers through successive oxidation and reduction reactions of the Cα hydroxy group of threo-DGPD with a net stereoinversion using multiple dehydrogenases. IMPORTANCE In many catalytic depolymerization processes of lignin polymers, aryl-ether bonds are selectively cleaved, leaving carbon-carbon bonds between aromatic units intact, including dimers and oligomers with ß-1 linkages. Therefore, elucidating the catabolic system of ß-1-type lignin-derived compounds will aid in the establishment of biological funneling of heterologous lignin-derived aromatic compounds to value-added products. Here, we found that threo-DGPD was converted by successive stereoselective oxidation and reduction at the Cα position by multiple alcohol dehydrogenases to erythro-DGPD, which is further catabolized. This system is very similar to that developed to obtain enantiopure alcohols from racemic alcohols by artificially combining two enantiocomplementary alcohol dehydrogenases. The results presented here demonstrate that SYK-6 has evolved to catabolize all four stereoisomers of DGPD by incorporating this stereoinversion system into its native ß-1-type dimer catabolic system.

Influencing factors of efficacy and long-term use of amrubicin in patients with small cell lung cancer.

BACKGROUND: Amrubicin (AMR) has become the standard of care for post-relapse small cell lung cancer (SCLC). It has also been reported to achieve long-term disease control in patients with good treatment response. However, the optimal patient population for whom AMR is effective and the factors associated with long-term disease control are yet to be identified. The aim of the study was to identify the clinical characteristics and factors associated with long-term disease control in patients with recurrent SCLC who would benefit from AMR therapy. METHODS: The clinical records of 33 patients diagnosed with recurrent SCLC and treated with AMR were retrospectively reviewed. Clinical information was compared between patients who achieved disease control (effective group) and who developed disease progression (noneffective group) on the first efficacy assessment after AMR and between patients who continued AMR for more than seven cycles (maintenance group) and those who terminated treatment after 1-6 cycles (discontinuation group). RESULTS: The noneffective group included significantly more patients with AMR dose reductions after the second cycle (p = 0.006). AMR dose reduction was an independent risk factor for disease progression. The maintenance group had significantly lower pretreatment lactate dehydrogenase (LDH) levels than the discontinuation group (p = 0.046). A high LDH level was an independent risk factor for short AMR discontinuation. Overall survival was significantly longer in the effective group than in the noneffective group (p < 0.001). CONCLUSIONS: In AMR therapy for patients with relapsed SCLC, continuation of AMR without dose reduction after the second cycle may contribute to disease control and prolonged survival.

Single-cell infrared vibrational analysis by optical trapping mid-infrared photothermal microscopy.

Single-cell analysis by means of vibrational spectroscopy combined with optical trapping is a reliable platform for unveiling cell-to-cell heterogeneities in vast populations. Although infrared (IR) vibrational spectroscopy provides rich molecular fingerprint information on biological samples in a label-free manner, its application with optical trapping has never been achieved due to weak gradient forces generated by the diffraction-limited focused IR beam and strong background of water absorption. Herein, we present single-cell IR vibrational analysis that incorporates mid-infrared photothermal (MIP) microscopy with optical trapping. Optically trapped single polymer particles and red blood cells (RBCs) in blood could be chemically identified owing to their IR vibrational fingerprints. This single-cell IR vibrational analysis further allowed us to probe the chemical heterogeneities of RBCs originating from the variation in the intracellular characteristics. Our demonstration paves the way for the IR vibrational analysis of single cells and chemical characterization in various fields.

Biochemical and structural characterization of a sphingomonad diarylpropane lyase for cofactorless deformylation.

Lignin valorization is being intensely pursued via tandem catalytic depolymerization and biological funneling to produce single products. In many lignin depolymerization processes, aromatic dimers and oligomers linked by carbon-carbon bonds remain intact, necessitating the development of enzymes capable of cleaving these compounds to monomers. Recently, the catabolism of erythro-1,2-diguaiacylpropane-1,3-diol (erythro-DGPD), a ring-opened lignin-derived ß-1 dimer, was reported in Novosphingobium aromaticivorans. The first enzyme in this pathway, LdpA (formerly LsdE), is a member of the nuclear transport factor 2 (NTF-2)-like structural superfamily that converts erythro-DGPD to lignostilbene through a heretofore unknown mechanism. In this study, we performed biochemical, structural, and mechanistic characterization of the N. aromaticivorans LdpA and another homolog identified in Sphingobium sp. SYK-6, for which activity was confirmed in vivo. For both enzymes, we first demonstrated that formaldehyde is the C1 reaction product, and we further demonstrated that both enantiomers of erythro-DGPD were transformed simultaneously, suggesting that LdpA, while diastereomerically specific, lacks enantioselectivity. We also show that LdpA is subject to a severe competitive product inhibition by lignostilbene. Three-dimensional structures of LdpA were determined using X-ray crystallography, including substrate-bound complexes, revealing several residues that were shown to be catalytically essential. We used density functional theory to validate a proposed mechanism that proceeds via dehydroxylation and formation of a quinone methide intermediate that serves as an electron sink for the ensuing deformylation. Overall, this study expands the range of chemistry catalyzed by the NTF-2-like protein family to a prevalent lignin dimer through a cofactorless deformylation reaction.

Differential response in patients with large cell neuroendocrine carcinoma of the lung to initial therapy: A case series.

BACKGROUND: Large cell neuroendocrine tumors of the lung (LCNEC) are rare. Chemotherapy with the small cell lung carcinoma (SCLC) regimen is the most appropriate treatment for LCNEC. However, there is evidence that the non-small cell lung cancer regimen is also effective in some reported cases. Due to the differences in response to LCNEC treatment, a standard of care for LCNEC has not been established. CASES: The clinical records of nine patients with LCNEC who were treated with anticancer drugs based on an SCLC regimen from March 2016 to March 2022 were retrospectively reviewed. The patients who responded to treatment after one cycle of systemic chemotherapy were compared to those who did not respond. All patients in the responder group had a performance status (PS) of 0 or 1. However, 5 of the 6 patients in the non-responder group had a PS of 2 or 3, indicating that many patients were in poor general condition. Although patients with multiple metastases to more than one organ prior to treatment were not identified in the responder group, five of these patients were in the non-responder group. In the non-responder group, all patients discontinued treatment due to deterioration of general condition during first-line treatment. Thus, none of them were able to start the second-line treatment. CONCLUSION: The results of this study may suggest that early diagnosis and initiation of treatment before multiple organ metastasis development and PS decline may have clinical implications that could lead to improved treatment response in patients with LCNEC.

Early recurrence factors in patients with stage III non-small cell lung cancer treated with concurrent chemoradiotherapy.

BACKGROUND: The clinical characteristics and risk factors for cancer recurrence have not been well evaluated regarding early recurrence in patients with unresectable locally advanced non-small cell lung cancer (LA-NSCLC) who receive concurrent chemoradiotherapy (CRT). The aim of this study was to determine the clinical characteristics and risk factors of patients with stage III unresectable LA-NSCLC treated with CRT who developed early recurrence. METHODS: We retrospectively reviewed the clinical records of 46 patients diagnosed with stage III unresectable LA-NSCLC treated with CRT at our center between July 2012 and July 2021. A tumor proportion score (TPS) < 50% was defined as "low expression" and a TPS > 50% was defined as "high expression." RESULTS: A total of 17 (37.0%) patients had a confirmed recurrence within 1 year of treatment. More patients had a lower body mass index in the early recurrence group than in the later recurrence group (p = 0.038). A higher number of patients in the late recurrence group underwent surgery after CRT (p = 0.036). Patients with a higher TPS were more likely to experience late recurrence than early recurrence (p = 0.001), whereas more patients with stage N3 disease were in the early recurrence group (p = 0.011). Multivariate analysis identified lower TPS expression as an independent risk factor for early recurrence after CRT. Overall survival was prolonged in the late recurrence group (p < 0.001). CONCLUSIONS: A lower TPS may be a predictor of early recurrence after CRT in patients with LA-NSCLC. These patients should be closely monitored for post-treatment recurrence.

High-sensitivity hyperspectral vibrational imaging of heart tissues by mid-infrared photothermal microscopy.

Visualizing the spatial distribution of chemical compositions in biological tissues is of great importance to study fundamental biological processes and origin of diseases. Raman microscopy, one of the label-free vibrational imaging techniques, has been employed for chemical characterization of tissues. However, the low sensitivity of Raman spectroscopy often requires a long acquisition time of Raman measurement or a high laser power, or both, which prevents one from investigating large-area tissues in a nondestructive manner. In this work, we demonstrated chemical imaging of heart tissues using mid-infrared photothermal (MIP) microscopy that simultaneously achieves the high sensitivity benefited from IR absorption of molecules and the high spatial resolution down to a few micrometers. We successfully visualized the distributions of different biomolecules, including proteins, phosphate-including proteins, and lipids/carbohydrates/amino acids. Further, we experimentally compared MIP microscopy with Raman microscopy to evaluate the sensitivity and photodamage to tissues. We proved that MIP microscopy is a highly sensitive technique for obtaining vibrational information of molecules in a broad fingerprint region, thereby it could be employed for biological and diagnostic applications, such as live-tissue imaging.

Serum Derivatives of Reactive Oxygen Metabolites are Associated with Severity of Chronic Obstructive Pulmonary Disease and Affected by a p53 Gene Polymorphism.

Purpose: Oxidative stress is known to activate tumor suppressor p53, which inhibits cell cycle progression and induces apoptosis. Levels of p53 in lung tissues from patients with chronic obstructive pulmonary disease (COPD) are increased compared with levels in nonsmokers or smokers without emphysema. A polymorphism in p53 codon 72 (rs1042522) is associated with emphysematous changes in patients with COPD. However, whether oxidative stress in the serum is associated with the p53 polymorphism and disease severity in COPD patients is unclear. Patients and Methods: A total of 251 patients with a history of smoking more than 10 pack-years were enrolled in this study, and serum levels of derivatives of reactive oxygen metabolites (d-ROMs), biological antioxidant potential (BAP), and d-ROMs/BAP ratio (oxidative stress index; OSI) were measured. The percent low-attenuation area (LAA%) and cross-sectional area of the erector spinae muscles (ESMCSA) at the Th12 level were calculated from chest high-resolution computed tomography images. p53 codon 72 C/G genotyping was performed using polymerase chain reaction-restriction fragment length polymorphism analysis. Results: In patients carrying the p53 GG genotype, LAA% was significantly higher than in those carrying the CC genotype. d-ROM levels and OSI were associated with COPD severity and correlated with airflow limitation and markers of muscle atrophy (ESMCSA and creatinine/cystatin C ratio). Associations between markers of oxidative stress and COPD severity were observed primarily in patients carrying the p53 codon 72 GG genotype. Conclusion: Susceptibility to pulmonary emphysema and responses to oxidative stress may be affected by the p53 gene polymorphism.

Ultrastable tip-enhanced hyperspectral optical nanoimaging for defect analysis of large-sized WS2 layers.

Optical nanoimaging techniques, such as tip-enhanced Raman spectroscopy (TERS), are nowadays indispensable for chemical and optical characterization in the entire field of nanotechnology and have been extensively used for various applications, such as visualization of nanoscale defects in two-dimensional (2D) materials. However, it is still challenging to investigate micrometer-sized sample with nanoscale spatial resolution because of severe limitation of measurement time due to drift of the experimental system. Here, we achieved long-duration TERS imaging of a micrometer-sized WS2 sample for 6 hours in a reproducible manner. Our ultrastable TERS system enabled to reveal the defect density on the surface of tungsten disulfide layers in large area equivalent to the device scale. It also helped us to detect rare defect-related optical signals from the sample. The present study paves ways to evaluate nanoscale defects of 2D materials in large area and to unveil remarkable optical and chemical properties of large-sized nanostructured materials.

Tip-enhanced Raman spectroscopy with amplitude-controlled tapping-mode AFM.

Tip-enhanced Raman spectroscopy (TERS) is a powerful tool for analyzing chemical compositions at the nanoscale owing to near-field light localized at a metallic tip. In TERS, atomic force microscopy (AFM) is commonly used for tip position control. AFM is often controlled under the contact mode for TERS, whereas the tapping mode, which is another major operation mode, has not often been employed despite several advantages, such as low sample damage. One of the reasons is the low TERS signal intensity because the tip is mostly away from the sample during the tapping motion. In this study, we quantitatively investigated the effect of the tapping amplitude on the TERS signal. We numerically evaluated the dependence of the TERS signal on tapping amplitude. We found that the tapping amplitude had a significant effect on the TERS signal, and an acceptable level of TERS signal was obtained by reducing the amplitude to a few nanometers. We further demonstrated amplitude-controlled tapping-mode TERS measurement. We observed a strong dependence of the TERS intensity on the tapping amplitude, which is in agreement with our numerical calculations. This practical but essential study encourages the use of the tapping mode for further advancing TERS and related optical techniques.

The Phenomenology of Anti-NMDA Receptor Encephalitis: A Comparison with "Primary Mental Confusion" in Late 19th Century French Psychiatry.

BACKGROUND: Although various studies have been conducted on anti-NMDA receptor encephalitis since it was first reported in 2007, few studies have closely examined its clinical course. METHODS: We analyzed 47 case reports of anti-NMDA receptor encephalitis that detailed its clinical course. RESULTS: The results of our study supported the clinical course proposed by Iizuka et al. CONCLUSIONS: From the results, it is suggested that the phenomenological features understood as indicative of anti-NMDA receptor encephalitis include: (1) antecedent common cold-like symptoms (31.9%) in the prodromal phase, (2) delirium or acute confusional state (65.9%), (3) symptoms considered to be sudden personality changes (40.4%) in the psychotic phase, (4) central hypoventilation (14.9%) in the unresponsive phase, (5) motor disturbances (57.4%), and (6) autonomic symptoms, mainly without fluctuations (48.9%), in the hyperkinetic phase. These features were found to be similar to "primary mental confusion" (confusion mentale primitive) in French psychiatry in the late 19th century. We believe that classical psychiatry can contribute considerably to the interpretation of biological research results.