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Optics Express Feb 2024Conventional photoacoustic endoscopy (PAE) is mostly for structural imaging, and its molecular imaging ability is quite limited. In this work, we address this issue and...
Conventional photoacoustic endoscopy (PAE) is mostly for structural imaging, and its molecular imaging ability is quite limited. In this work, we address this issue and present the development of a flexible acoustic-resolution-based photoacoustic endoscopic (AR-PAE) probe with an outer diameter of 8 mm. This probe is driven by a micro-step motor at the distal end, enabling flexible and precise angular step control to synchronize with the optical parametric oscillator (OPO) lasers. This probe retains the high spatial resolution, high penetration depth, and spectroscopic imaging ability of conventional AR-PAE. Moreover, it is capable for background-free high-specific photoacoustic molecular imaging with a novel pump-probe detection technique, as demonstrated by the distribution visualizing of the FDA approved contrast agent methylene blue (MB) in an ex-vivo pig ileum. This proposed method represents an important technical advancement in multimodal PAE, and can potentially make considerable contributions across various biomedical fields.
Topics: Animals; Swine; Endoscopes; Molecular Imaging; Spectrum Analysis; Contrast Media; Methylene Blue
PubMed: 38439489
DOI: 10.1364/OE.514282 -
TheScientificWorldJournal 2024In this study, we investigated the use of manganese oxide-biochar nanocomposites (MnOx-BNC), synthesized from coffee husk (CH) and khat leftover (KL) for the removal of...
In this study, we investigated the use of manganese oxide-biochar nanocomposites (MnOx-BNC), synthesized from coffee husk (CH) and khat leftover (KL) for the removal of methylene blue (MB) from wastewater. Pristine biochars of each biomass (CH and KL) as well as their corresponding biochar-based nanocomposites were synthesized by pyrolyzing at 300°C for 1 h. The biochar-based nanocomposites were synthesized by pretreating 25 g of each biomass with 12.5 mmol of KMnO. To assess the MB removal efficiency, we conducted preliminary tests using 0.2 g of each adsorbent, 20 mL of 20 mg·L MB, pH 7.5, and shaking the mixture at 200 rpm and for 2 h at 25°C. The results showed that the pristine biochar of CH and KL removed 39.08% and 75.26% of MB from aqueous solutions, respectively. However, the MnOx-BNCs removed 99.27% with manganese oxide-coffee husk biochar nanocomposite (MnOx-CHBNC) and 98.20% with manganese oxide-khat leftover biochar nanocomposite (MnOx-KLBNC) of the MB, which are significantly higher than their corresponding pristine biochars. The adsorption process followed the Langmuir isotherm and a pseudo-second-order model, indicating favorable monolayer adsorption. The MnOx-CHBNC and MnOx-KLBNC demonstrated satisfactory removal efficiencies even after three and six cycles of reuse, respectively, indicating their potential effectiveness for alternative use in removing MB from wastewater.
Topics: Wastewater; Catha; Coffea; Methylene Blue; Nanocomposites; Charcoal; Oxides; Manganese Compounds
PubMed: 38434937
DOI: 10.1155/2024/7585145 -
Journal of Biomedical Optics Feb 2024Efficacious photodynamic therapy (PDT) of abscess cavities requires personalized treatment planning. This relies on knowledge of abscess wall optical properties, which...
SIGNIFICANCE
Efficacious photodynamic therapy (PDT) of abscess cavities requires personalized treatment planning. This relies on knowledge of abscess wall optical properties, which we report for the first time in human subjects.
AIM
The objective was to extract optical properties and photosensitizer concentration from spatially resolved diffuse reflectance measurements of abscess cavities prior to methylene blue (MB) PDT, as part of a phase 1 clinical trial.
APPROACH
Diffuse reflectance spectra were collected at the abscess wall of 13 human subjects using a custom fiber-optic probe and optical spectroscopy system, before and after MB administration. A Monte Carlo lookup table was used to extract optical properties.
RESULTS
Pre-MB abscess wall absorption coefficients at 665 nm were (0.03 to ) and (0.08 to ) post-MB. Reduced scattering coefficients at 665 nm were (4.8 to ) and (1.6 to ) for pre-MB and post-MB, respectively. Oxygen saturations were found to be (5.6% to 100%) pre-MB and (0.0001% to 76.4%) post-MB. Determined MB concentrations were (0 to ).
CONCLUSIONS
We observed substantial inter-subject variation in both native wall optical properties and MB uptake. This underscores the importance of making these measurements for patient-specific treatment planning.
Topics: Humans; Abscess; Methylene Blue; Photochemotherapy; Photosensitizing Agents; Spectrum Analysis
PubMed: 38414658
DOI: 10.1117/1.JBO.29.2.027002 -
Molecules (Basel, Switzerland) Feb 2024Phthalocyanines and their double-decker complexes are interesting in designing rotative molecular machines, which are crucial for the development of molecular motors and...
Phthalocyanines and their double-decker complexes are interesting in designing rotative molecular machines, which are crucial for the development of molecular motors and gears. This study explores the design and synthesis of three bulky phthalocyanine ligands functionalized at the α-positions with phenothiazine or carbazole fragments, aiming to investigate dynamic rotational motions in these sterically hindered molecular complexes. Homoleptic and heteroleptic double-decker complexes were synthesized through the complexation of these ligands with Ce(IV). Notably, and , both homoleptic complexes, exhibited blocked rotational motions even at high temperatures. The heteroleptic complex, designed to lower symmetry, demonstrated switchable rotation along the pseudo-C symmetry axis upon heating the solution. Variable-temperature H-NMR studies revealed distinct dynamic behaviors in these complexes. This study provides insights into the rotational dynamics of sterically hindered double-decker complexes, paving the way for their use in the field of rotative molecular machines.
PubMed: 38398640
DOI: 10.3390/molecules29040888 -
Biosensors Jan 2024An electrochemically reduced graphene oxide (ERGO) electrode-based electrochemical assay was developed for rapid, sensitive, and straightforward analysis of both...
An electrochemically reduced graphene oxide (ERGO) electrode-based electrochemical assay was developed for rapid, sensitive, and straightforward analysis of both activity and inhibition of the endonuclease EcoRV. The procedure uses a DNA substrate designed for EcoRV, featuring a double-stranded DNA (dsDNA) region labeled with methylene blue (MB) and a single-stranded DNA (ssDNA) region immobilized on the ERGO surface. The ERGO electrode, immobilized with the DNA substrate, was subsequently exposed to a sample containing EcoRV. Upon enzymatic hydrolysis, the cleaved dsDNA fragments were detached from the ERGO surface, leading to a decrease in the MB concentration near the electrode. This diminished the electron transfer efficiency for MB reduction, resulting in a decreased reduction current. This assay demonstrates excellent specificity and high sensitivity, with a limit of detection (LOD) of 9.5 × 10 U mL. Importantly, it can also measure EcoRV activity in the presence of aurintricarboxylic acid, a known inhibitor, highlighting its potential for drug discovery and clinical diagnostic applications.
Topics: DNA Cleavage; DNA; DNA, Single-Stranded; Graphite; Methylene Blue; Electrodes; Electrochemical Techniques
PubMed: 38391992
DOI: 10.3390/bios14020073 -
RSC Advances Feb 2024Thermally activated delayed fluorescence (TADF) molecules have emerged as a promising class of third-generation organic light-emitting diode (OLED) emitters that can...
Thermally activated delayed fluorescence (TADF) molecules have emerged as a promising class of third-generation organic light-emitting diode (OLED) emitters that can achieve 100% internal quantum efficiency without the use of noble metals. However, the design of high-efficiency red TADF materials has been challenging due to limitations imposed by the energy-gap law. To overcome this challenge, two new TADF emitters, namely, 6-(4-(diphenylamino)phenyl)-2-phenyl-1-benzo[]isoquinoline-1,3(2)-dione (NI-TPA) and 6-(10-phenothiazin-10-yl)-2-phenyl-1-benzo[]-isoquinoline-1,3(2)-dione (NI-Pz), have been synthesized and characterized. These compounds exhibit strong TADF characteristics with a small energy gap (Δ) between the lowest excited singlet and triplet states, short delayed fluorescence lifetimes, high thermal stability, and high photoluminescence quantum yields. The OLED devices fabricated using NI-TPA and NI-Pz as emitters show orange and red electroluminescence with emission peaks at 593 nm and 665 nm, respectively, and maximum external quantum efficiencies (EQEs) of 11.3% and 7.6%, respectively. Furthermore, applying NI-TPA to cell imaging yielded excellent imaging results, indicating the potential of red TADF materials in the field of biological imaging.
PubMed: 38390502
DOI: 10.1039/d3ra08969j -
Scientific Reports Feb 2024In this work, the electrochemical generation of phenothiazin-5-ium (PTZ) from the direct oxidation of phenothiazine (PTZ) in a water/acetonitrile mixture using a...
In this work, the electrochemical generation of phenothiazin-5-ium (PTZ) from the direct oxidation of phenothiazine (PTZ) in a water/acetonitrile mixture using a commercial carbon anode and conventional stainless steel cathode is reported. PTZ is a reactive intermediate with high potential synthetic applications, which is used in this paper for the synthesis of new phenothiazine derivatives. In this work a novel and simple electrochemical methodology for the synthesis of some bis(phenylsulfonyl)-10H-phenothiazine derivatives was established. In this paper, a mechanism for PTZ oxidation in the presence of arylsulfinic acids has been proposed based on the results obtained from voltammetric and coulometric experiments as well as spectroscopic data of the products. These syntheses are performed in a simple cell by applying constant current under mild conditions and at room temperature with high atom economy.
PubMed: 38383682
DOI: 10.1038/s41598-024-53620-0 -
Journal of Psychiatric Research Apr 2024Pharmacological treatment strategies for insomnia seem to vary, and there is lack of knowledge about how sedative drugs are used in a real-world setting. We investigated...
OBJECTIVE
Pharmacological treatment strategies for insomnia seem to vary, and there is lack of knowledge about how sedative drugs are used in a real-world setting. We investigated changes in sedative drug prescription patterns in Danish adults who initiated treatment between 2002 and 2016.
METHODS
All adults with a first-time purchase of a sedative drug registered in the Danish National Prescription Register from 2002 through 2016 were followed for five years between 2002 and 2021 for subsequent prescriptions of sedative drugs, death, or emigration. Sedative drugs were classified into anxiolytic benzodiazepines (N05BA), hypnotic benzodiazepines (N05CD), Z-drugs (N05CF), melatonin (N05CH01), promethazine (R06AD), and low-dose quetiapine (N05AH04). Analyses were stratified on time: 2002-2006, 2007-2011, and 2012-2016.
RESULTS
A total of 842,880 individuals purchased their first sedative drug between 2002 and 2016. Most of them (40.0%) initiated treatment between 2002 and 2006, whereas 29.2% initiated treatment in 2012-2016. In 2002-2006, anxiolytic benzodiazepines (46.4%), Z-drugs (42.8%), and hypnotic benzodiazepines (5.4%) were the most common first treatment. This pattern changed over time with a gradual increase in the use of melatonin, promethazine, and low-dose quetiapine, which in 2011-2016 accounted for 27% of all first treatments. During the five years from first prescription, around 27% shifted to a different sedative drug. This percentage increased slightly over time, but over time the first shift to another drug class was most often to a Z-drug or anxiolytic benzodiazepine. Few individuals (5.8%) had more than one shift and the third choice seemed randomly distributed across all other drug classes.
CONCLUSION
Sedative drug prescriptions are distributed on different drug classes, with Z-drugs and anxiolytic benzodiazepines as the most frequent first treatment, and second choice in case of shift.
Topics: Adult; Humans; Hypnotics and Sedatives; Anti-Anxiety Agents; Cohort Studies; Quetiapine Fumarate; Promethazine; Melatonin; Benzodiazepines; Drug Prescriptions; Denmark
PubMed: 38377668
DOI: 10.1016/j.jpsychires.2023.12.040 -
Surgical Oncology Apr 2024In patients with colorectal cancer (CRC), the most important factor to decide the need of adjuvant chemotherapy is the histological lymph node (LN) evaluation. Our work... (Meta-Analysis)
Meta-Analysis Review
PURPOSE
In patients with colorectal cancer (CRC), the most important factor to decide the need of adjuvant chemotherapy is the histological lymph node (LN) evaluation. Our work aimed to give a broad view over the use of methylene blue and its consequences in the number of lymph node harvest.
METHODS
PUBMED, WEB OF SCIENCE and EMBASE databases were consulted, retrieving clinical trials, which mentioned the used of intra-arterial methylene blue in patients with colorectal cancer.
RESULTS
Eighteen clinical trials analyzing the use of intra-arterial methylene blue in specimens of colorectal cancer were selected. The articles show a statistical difference between the use of methylene blue and the classical dissection in both variable at study. The results of the statistical analysis of the lymph node harvest variable demonstrate a significant statistical difference between the group that received methylene blue injection and the group that underwent conventional dissection. There is a significant statistical difference between the experimental and control groups for the ideal lymph node harvest (lymph node harvest count greater than 12).
CONCLUSION
The use of intra-arterial methylene blue revealed a high potential for the quantification of lymph nodes, considering the increase of lymph node harvest and the higher percentage of cases with more than 12 lymph nodes count, albeit the high heterogeneity between the studies in terms of reported results. Future investigations with controlled double blinded studies obtaining better categorized results should be conducted in order to better evaluate this technique and compare it to the current paradigm.
Topics: Humans; Lymph Node Excision; Methylene Blue; Lymph Nodes; Dissection; Colorectal Neoplasms; Sentinel Lymph Node Biopsy
PubMed: 38377643
DOI: 10.1016/j.suronc.2024.102046 -
Critical Care (London, England) Feb 2024Septic shock typically requires the administration of vasopressors. Adrenergic agents remain the first choice, namely norepinephrine. However, their use to counteract... (Review)
Review
Septic shock typically requires the administration of vasopressors. Adrenergic agents remain the first choice, namely norepinephrine. However, their use to counteract life-threatening hypotension comes with potential adverse effects, so that non-adrenergic vasopressors may also be considered. The use of agents that act through different mechanisms may also provide an advantage. Nitric oxide (NO) is the main driver of the vasodilation that leads to hypotension in septic shock, so several agents have been tested to counteract its effects. The use of non-selective NO synthase inhibitors has been of questionable benefit. Methylene blue, an inhibitor of soluble guanylate cyclase, an important enzyme involved in the NO signaling pathway in the vascular smooth muscle cell, has also been proposed. However, more than 25 years since the first clinical evaluation of MB administration in septic shock, the safety and benefits of its use are still not fully established, and it should not be used routinely in clinical practice until further evidence of its efficacy is available.
Topics: Humans; Methylene Blue; Shock, Septic; Hypotension; Soluble Guanylyl Cyclase; Norepinephrine; Vasoconstrictor Agents
PubMed: 38365828
DOI: 10.1186/s13054-024-04839-w