200 research outputs found
PSN-PC: A Novel Antimicrobial and Anti-Biofilm Peptide from the Skin Secretion of Phyllomedusa-camba with Cytotoxicity on Human Lung Cancer Cell
Peptides derived from amphibian skin secretion are promising drug prototypes for combating widespread infection. In this study, a novel peptide belonging to the phylloseptin family of antimicrobial peptides was isolated from the skin secretion of the Phyllomedusa camba, namely phylloseptin-PC (PSN-PC). The biosynthetic precursor was obtained by molecular cloning and the mature peptide sequence was confirmed through tandem mass spectrometry (MS/MS) fragmentation sequencing in the skin secretion. The synthetic replicate exhibited a broad spectrum antimicrobial activity against Staphylococcus aureus, methicillin-resistant Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Candida albicans at concentrations of 2, 2, 8, 32 and 2 µM, respectively. It also showed the capability of eliminating S. aureus biofilm with a minimal biofilm eradication concentration of 8 µM. The haemolysis of this peptide was not significant at low concentrations but had a considerable increase at high concentrations. Additionally, this peptide showed an anti-proliferation effect on the non-small cell lung cancer cell line (NCI-H157), with low cytotoxicity on the human microvascular endothelial cell line (HMEC-1). The discovery of the novel peptide may provide useful clues for new drug discoveries
Study of prevalence and risk factors of chemotherapy-induced mucositis in gastrointestinal cancer using machine learning models
ObjectiveChemotherapy-induced mucositis (CIM) significantly impacts clinical outcomes and diminishes the quality of life in patients with gastrointestinal cancer. This study aims to prospectively determine the incidence, severity, and underlying risk factors associated with CIM in this patient population.MethodsTo achieve this objective, we introduce a novel Machine Learning-based Toxicity Prediction Model (ML-TPM) designed to analyze the risk factors contributing to CIM development in gastrointestinal cancer patients. Within the winter season spanning from December 15th, 2018 to January 14th, 2019, we conducted in-person interviews with patients undergoing chemotherapy for gastrointestinal cancer. These interviews encompassed comprehensive questionnaires pertaining to patient demographics, CIM incidence, severity, and any supplementary prophylactic measures employed.ResultsThe study encompassed a cohort of 447 participating patients who provided complete questionnaire responses (100%). Of these, 328 patients (73.4%) reported experiencing CIM during the course of their treatment. Notably, CIM-induced complications led to treatment discontinuation in 14 patients (3%). The most frequently encountered CIM symptoms were diarrhea (41.6%), followed by nausea (37.8%), vomiting (25.1%), abdominal pain (21%), gastritis (10.5%), and oral pain (10.3%). Supplementary prophylaxis was administered to approximately 62% of the patients. The analysis revealed significant correlations between the overall incidence of CIM and gender (p=0.015), number of chemotherapy cycles exceeding one (p=0.039), utilization of platinum-based regimens (p=0.039), and administration of irinotecan (p=0.003). Specifically, the incidence of diarrhea exhibited positive correlations with prior surgical history (p=0.037), irinotecan treatment (p=0.021), and probiotics usage (p=0.035). Conversely, diarrhea incidence demonstrated an adverse correlation with platinum-based treatment (p=0.026).ConclusionIn conclusion, this study demonstrates the successful implementation of the ML-TPM model for automating toxicity prediction with accuracy comparable to conventional physical analyses. Our findings provide valuable insights into the identification of CIM risk factors among gastrointestinal cancer patients undergoing chemotherapy. Furthermore, the results underscore the potential of machine learning in enhancing our understanding of chemotherapy-induced mucositis and advancing personalized patient care strategies
Emergent superconducting fluctuations in a compressed kagome superconductor
The recent discovery of superconductivity (SC) and charge density wave (CDW)
in kagome metals AV3Sb5 (A = K, Rb, Cs) provides an ideal playground for the
study of emergent electronic orders. Application of moderate pressure leads to
a two-dome-shaped SC phase regime in CsV3Sb5 accompanied by the destabilizing
of CDW phase; such unconventional evolution of SC may involve the
pressure-induced formation of a new stripe-like CDW order resembling that in
La-214 cuprate superconductors. Nonetheless, the nature of this pressure-tuned
SC state and its interplay with the stripe order are yet to be explored. Here,
we perform soft point-contact spectroscopy (SPCS) measurements in CsV3Sb5 to
investigate the evolution of superconducting order parameter with pressure.
Surprisingly, we find that the superconducting gap is significantly enhanced
between the two SC domes, at which the zero-resistance temperature is
suppressed and the transition is remarkably broadened. Moreover, the
temperature dependence of the SC gap in this pressure range severely deviates
from the conventional BCS behavior, evidencing for strong Cooper pair phase
fluctuations. These findings reveal the complex intertwining of the stripe-like
CDW with SC in the compressed CsV3Sb5, suggesting striking parallel to the
cuprate superconductor La2-xBaxCuO4. Our results point to the essential role of
charge degree of freedom in the development of intertwining electronic orders,
thus provides new constraints for theories.Comment: 16 pages, 4 figure
Magnetic-field-induced electronic instability of Weyl-like fermions in compressed black phosphorus
Revealing the role of Coulomb interaction in topological semimetals with
Dirac/Weyl-like band dispersion shapes a new frontier in condensed matter
physics. Topological node-line semimetals (TNLSMs), anticipated as a fertile
ground for exploring electronic correlation effects due to the anisotropy
associated with their node-line structure, have recently attracted considerable
attention. In this study, we report an experimental observation for correlation
effects in TNLSMs realized by black phosphorus (BP) under hydrostatic pressure.
By performing a combination of nuclear magnetic resonance measurements and band
calculations on compressed BP, a magnetic-field-induced electronic instability
of Weyl-like fermions is identified under an external magnetic field parallel
to the so-called nodal ring in the reciprocal space. Anomalous spin
fluctuations serving as the fingerprint of electronic instability are observed
at low temperatures, and they are observed to maximize at approximately 1.0
GPa. This study presents compressed BP as a realistic material platform for
exploring the rich physics in strongly coupled Weyl-like fermions.Comment: 10 pages, 4 figure
and Oxygen Stoichiometry: Structure, Resistivity, Fermi Surface Topology and Normal State Properties
(2212) single crystal samples
were studied using transmission electron microscopy (TEM), plane
() and axis () resistivity, and high resolution
angle-resolved ultraviolet photoemission spectroscopy (ARUPS). TEM reveals that
the modulation in the axis for doped 2212 is dominantly
of type that is not sensitive to the oxygen content of the system, and the
system clearly shows a structure of orthorhombic symmetry. Oxygen annealed
samples exhibit a much lower axis resistivity and a resistivity minimum at
K. He-annealed samples exhibit a much higher axis resistivity and
behavior below 300K. The Fermi surface (FS) of oxygen annealed
2212 mapped out by ARUPS has a pocket in the FS around the
point and exhibits orthorhombic symmetry. There are flat, parallel sections of
the FS, about 60\% of the maximum possible along , and about 30\%
along . The wavevectors connecting the flat sections are about
along , and about along , rather than . The symmetry of the near-Fermi-energy dispersing
states in the normal state changes between oxygen-annealed and He-annealed
samples.Comment: APS_REVTEX 3.0, 49 pages, including 11 figures, available upon
request. Submitted to Phys. Rev. B
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