ABSTRACT
Compositional tunability, an indispensable parameter for modifying the properties of materials, can open up new applications for van der Waals (vdW) layered materials such as transition-metal dichalcogenides (TMDCs). To date, multielement alloy TMDC layers are obtained via exfoliation from bulk polycrystalline powders. Here, we demonstrate direct deposition of high-entropy alloy disulfide, (VNbMoTaW)S2, layers with controllable thicknesses on free-standing graphene membranes and on bare and hBN-covered Al2O3(0001) substrates via ultra-high-vacuum reactive dc magnetron sputtering of the VNbMoTaW target in Kr and H2S gas mixtures. Using a combination of density functional theory calculations, Raman spectroscopy, X-ray diffraction, scanning transmission electron microscopy coupled with energy dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy, we determine that the as-deposited layers are single-phase, 2H-structured, and 0001-oriented (V0.10Nb0.16Mo0.19Ta0.28W0.27)S2.44. Our synthesis route is general and applicable for heteroepitaxial growth of a wide variety of TMDC alloys and potentially other multielement alloy vdW compounds with the desired compositions.
ABSTRACT
Long-lived proteins undergo chemical modifications that can cause age-related diseases. Among these chemical modifications, isomerization is the most difficult to identify. Isomerization often occurs at the aspartic acid (Asp) residues. In this study, we used tandem mass spectrometry equipped with a newly developed ion activation method, hydrogen attachment dissociation (HAD), to analyze peptides containing Asp isomers. Although HAD preferentially produces [cn + 2H]+ and [zm + 2H]+ via N-Cα bond cleavage, [cn + 58 + 2H]+ and [zm - 58 + 2H]+ originate from the fragmentation of the isoAsp residue. Notably, [cn + 58 + 2H]+ and [zm - 58 + 2H]+ could be used as diagnostic fragment ions for the isoAsp residue because these fragment ions did not originate from the Asp residue. The detailed fragmentation mechanism was investigated by computational analysis using density functional theory. According to the results, hydrogen attachment to the carbonyl oxygen in the isoAsp residue results in the Cα-Cß bond cleavage. The experimental and theoretical joint study indicates that the present method allows us to discriminate Asp and isoAsp residues, including site identification of the isoAsp residue. Moreover, we demonstrated that the molar ratio of peptide isomers in the mixture could be estimated from their fragment ion abundance. Therefore, tandem mass spectrometry with HAD is a useful method for the rapid discrimination and semiquantitative analysis of peptides containing isoAsp residues.
Subject(s)
Aspartic Acid , Hydrogen , Isoaspartic Acid , Peptides , Tandem Mass Spectrometry , Tandem Mass Spectrometry/methods , Aspartic Acid/chemistry , Aspartic Acid/analysis , Isoaspartic Acid/chemistry , Isoaspartic Acid/analysis , Peptides/chemistry , Peptides/analysis , Hydrogen/chemistry , IsomerismABSTRACT
To characterise the glucose-induced protein fragments by MALDI-TOF MS analysis, we compared data for samples from Escherichia coli cultured in media with or without glucose. Characteristic peaks were observed in the presence of glucose, and MS/MS revealed Asr-specific fragments. The amino acid sequences of the fragments suggested sequence-specific proteolysis. Blast-analysis revealed that numerous Enterobacterales harbored genes encoding Asr as well as E. coli. Here, we analysed 32 strains from 20 genera and 25 species of seven Enterobacterales families. We did not detect changes in the mass spectra of four strains of Morganellaceae lacking asr, whereas peaks of Asr-specific fragments were detected in the other 28 strains. We therefore concluded that the induction of Asr production in the presence of glucose is common among the Enterobacterales, except for certain Morganellaceae species. In members of family Budviciaceae, unfragmented Asr was detected. Molecular genetic information suggested that the amino acid sequences of Asr homologs are diverse, with fragments varying in number and size, indicating that Asr may serve as a discriminative biomarker for identifying Enterobacterales species.
ABSTRACT
BACKGROUND: Suicide is a leading cause of death in children. The COVID-19 pandemic might change the characteristics, causes (medical, suicidal, accidental, and other non-medical), and outcomes of pediatric OHCA. This study aimed to investigate the impact of pediatric OHCA in age, location, and quarantine-related movement restriction subgroups. METHODS: Combining the nationwide OHCA registry with the emergency medical service transportation database, we created a database with detailed information on 7657 non-neonatal, pediatric OHCA cases. RESULTS: The pandemic period did not significantly alter neurologically favorable 1-month survival compared to pre-pandemic 4 years (95% confidence interval 0.73-1.00). However, the survival rate significantly decreased in the following subgroups of OHCA: school-age (0.62-0.96), outside of school or home (0.52-0.96), and cases where no quarantine-related movement restrictions were applied (0.68-0.97). There was a prominent increase in the proportion of suicide-related OHCA in these subgroups: from 30.3 to 38.1% (1.22-1.64), from 10.2 to 15.9% (1.21-2.28), and from 12.5 to 17.8% (1.30-1.77), respectively. CONCLUSION: The COVID-19 pandemic did not significantly alter neurologically favorable 1-month survival. However, it led to worsened survival in subgroups with higher suicide attempt rates. Prevention of suicide is likely essential in the assurance of children's lives during the pandemic. IMPACT: This cohort study found that during the 2020/2021 pandemic, neurologically favorable survival decreased in school-age out-of-hospital cardiac arrest (OHCA) cases, those not subject to quarantine-related movement restrictions, and those in locations outside of school or home. Within these three subgroups, there was a notable rise in OHCA cases related to suicide, historically known to be more challenging to manage successfully. However, survival rates for overall OHCA and medically related OHCA cases remained unchanged throughout the pandemic. Preventive measures for suicide attempts may be necessary to improve the overall survival of pediatric OHCA during the pandemic.
ABSTRACT
Leptospirosis is a widespread zoonosis in tropical regions and it is not frequently recognised in developed countries. We report a case of leptospirosis transmitted from a pet dog. A middle-aged woman was referred to our emergency department with a 7-day history of fever and diarrhoea. She presented with hypotension, tachycardia, grasping pain in the entire muscle and petechiae. A detailed medical interview revealed that her pet dog had been to the veterinarian 1 month earlier with similar symptoms. We treated her with intravenous antibiotics. The patient's diagnosis of leptospirosis was confirmed by serological testing and the detection of DNA in her urine. We contacted the veterinarian and shared the information. We found that the dog had suffered from leptospirosis based on serological testing. We emphasise the possibility of leptospirosis being transmitted from pet dogs. Persistent suspicion of leptospirosis will contribute to its diagnosis and improved public health.
Subject(s)
Anti-Bacterial Agents , Dog Diseases , Leptospirosis , Pets , Leptospirosis/diagnosis , Leptospirosis/drug therapy , Leptospirosis/transmission , Leptospirosis/veterinary , Dogs , Humans , Animals , Female , Dog Diseases/diagnosis , Dog Diseases/microbiology , Dog Diseases/drug therapy , Middle Aged , Anti-Bacterial Agents/therapeutic use , Pets/microbiology , Zoonoses/diagnosis , Zoonoses/transmission , Zoonoses/microbiologyABSTRACT
OBJECTIVES: Reportedly, coronavirus disease pandemic 2019 (COVID 19) was associated with an increased rate of emergency department visits related to suicide in youth. This study analyzed the influence of the pandemic on the incidence of emergency transportation associated with suicide attempts and self-harm. METHODS: This retrospective cohort study used the Nationwide Emergency Medical Services Transportation Database between 2016 and 2021 for main analyses and extended database for resuscitation-attempted out-of-hospital cardiac arrests cases for secondary analyses. RESULTS: We analyzed 204,081 cases with suicidal/self-harm emergencies. Compared with corresponding periods of 4 pre-pandemic years, the incidence of suicidal/self-harm emergencies increased after the end of the first nationwide declaration of emergency and remained high in youth (incidence rate ratio; 95% lower/upper interval, 1.29; 1.22-1.37 and 1.33; 1.28-1.39,), particularly in females (1.35; 1.27-1.46 and 1.40; 1.33-1.48) during the remaining pandemic period (Phase I (June 2020 to December 2020) and Phase II (2021), respectively). Compared with other emergencies, suicidal/self-harm emergencies were associated with a much higher proportion of outpatient deaths regardless of the pandemic. Suicidal out-of-hospital cardiac arrests cases were associated with much poorer outcomes. CONCLUSION: The incidence of suicidal/self-harm emergency transportation in youth considerably increased during COVID 19 after the end of the first state of emergency declaration in Japan. This pandemic's impact varied among sex and region, appearing most prominently in young females. Rapid accumulation of suicidal/self-harm emergency transportation incidences may serve as an early warning sign for mental health problems and suicidality in Japan.
ABSTRACT
BACKGROUND: In sharp contrast with analysis of N-glycan that can be prepared by PNGase F, O-glycan analysis remains challenging due to a lack of versatile and simple procedures, especially those mediating cleavage of O-glycans from proteins. Most N-glycans and O-glycans are modified with sialic acids at the non-reducing end and their glycosidic linkages are labile, making it difficult to measure glycans by mass spectrometric analysis. In addition, sialic acid residues present on glycan chains via α2,3-, α2,6-, and α2,8-linkages as structural isomers. RESULTS: In this study, we firstly established a direct and linkage-specific derivatization method for sialylated O-glycans on proteins via linkage-specific lactone-opening aminolysis. In this procedure, labile sialylated glycans were not only stabilized, but also allowed distinguishing between sialyl linkages. Furthermore, we revealed that general reductive ß-elimination was not useful for O-glycan cleavages with undesirable degradations of resulting methyl amides. Using ß-elimination in the presence of pyrazolone (PMP), with low pH despite alkali base concentration, SALSA-derivatized O-glycans could be cleaved with minimal degradations. Cleaved and PMP-labeled O-glycans could be efficiently prepared in an open reaction system at high temperature (evaporative BEP reaction) and detected by simple liquid-phase extraction. Moreover, in the evaporative BEP reaction by changing the alkali solution with LiOH, the lithiated O-glycans could be observed and provided a lot of fragment information reflecting the complex structure of the O-glycans. SIGNIFICANCE: Direct sialic acid linkage-specific derivatization of O-glycans on glycoproteins is simple protocol containing in-solution aminolysis-SALSA and acetonitrile precipitation for removal of excess reagents. Evaporative ß-elimination with pyrazolone makes possible intact O-linked glycan analysis just by liquid-phase extraction. These analytical methods established by the appropriate combination of direct-SALSA and evaporative ß-elimination will facilitate O-glycomic studies in various biological samples.
Subject(s)
Polysaccharides , Sialic Acids , Polysaccharides/chemistry , Sialic Acids/chemistryABSTRACT
In this study, a murine sepsis model was developed using the cecum ligation and puncture (CLP) technique. The expression of the proinflammatory cytokines tumor necrosis factor alpha (TNF-α) and interleukin-1ß (IL-1ß) in the brain increased 6 h after CLP but decreased 24 h later when elevated endogenous dopamine levels in the brain were sustained. Methyl-4-phenyl-1,2,3,6-tetrahydropyridine hydrochloride reduced dopamine levels in the striatum and increased mortality in septic mice. Dopamine D1-like receptors were significantly expressed in the brain, but not in the lungs. Intraperitoneally administered SKF-81297 (SKF), a blood-brain barrier-permeable D1-like receptor agonist, prevented CLP-induced death of septic mice with ameliorated acute lung injury and cognitive dysfunction and suppressed TNF-α and IL-1ß expression. The D1-like receptor antagonist SCH-23390 abolished the anti-inflammatory effects of SKF. These data suggest that D1-like receptor-mediated signals in the brain prevent CLP-induced inflammation in both the brain and the periphery.
ABSTRACT
Mycobacteroides (Mycobacterium) abscessus, which causes a variety of infectious diseases in humans, is becoming detected more frequently in clinical specimens as cases are spreading worldwide. Taxonomically, M. abscessus is composed of three subspecies of M. abscessus subsp. abscessus, M. abscessus subsp. bolletii, and M. abscessus subsp. massiliense, with different susceptibilities to macrolides. In order to identify rapidly these three subspecies, we determined useful biomarker proteins, including ribosomal protein L29, L30, and hemophore-related protein, for distinguishing the subspecies of M. abscessus using the matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) profiles. Thirty-three clinical strains of M. abscessus were correctly identified at the subspecies-level by the three biomarker protein peaks. This study ultimately demonstrates the potential of routine MALDI-MS-based laboratory methods for early identification and treatment for M. abscessus infections.
Subject(s)
Bacterial Proteins , Mycobacterium abscessus , Ribosomal Proteins , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/methods , Ribosomal Proteins/metabolism , Ribosomal Proteins/analysis , Mycobacterium abscessus/metabolism , Bacterial Proteins/metabolism , Humans , Mycobacterium Infections, Nontuberculous/microbiology , Mycobacterium Infections, Nontuberculous/diagnosis , Biomarkers/analysis , Biomarkers/metabolismABSTRACT
The use of trivalent erbium (Er3+), typically embedded as an atomic defect in the solid-state, has widespread adoption as a dopant in telecommunication devices and shows promise as a spin-based quantum memory for quantum communication. In particular, its natural telecom C-band optical transition and spin-photon interface make it an ideal candidate for integration into existing optical fiber networks without the need for quantum frequency conversion. However, successful scaling requires a host material with few intrinsic nuclear spins, compatibility with semiconductor foundry processes, and straightforward integration with silicon photonics. Here, we present Er-doped titanium dioxide (TiO2) thin film growth on silicon substrates using a foundry-scalable atomic layer deposition process with a wide range of doping controls over the Er concentration. Even though the as-grown films are amorphous after oxygen annealing, they exhibit relatively large crystalline grains, and the embedded Er ions exhibit the characteristic optical emission spectrum from anatase TiO2. Critically, this growth and annealing process maintains the low surface roughness required for nanophotonic integration. Finally, we interface Er ensembles with high quality factor Si nanophotonic cavities via evanescent coupling and demonstrate a large Purcell enhancement (≈300) of their optical lifetime. Our findings demonstrate a low-temperature, nondestructive, and substrate-independent process for integrating Er-doped materials with silicon photonics. At high doping densities this platform can enable integrated photonic components such as on-chip amplifiers and lasers, while dilute concentrations can realize single ion quantum memories.