100 research outputs found

    Developing Luminescent Lanthanide Coordination Polymers and Metal-Organic Frameworks for Bioimaging Applications

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    This study focuses on the solvothermal synthesis of two lanthanide-based coordination polymer/metal-organic framework systems assembled from 1,3,5-benzenetricarboxylic acid (BTC) in the nano-sized regime for use as bioimaging agents. These materials were synthesized using two different lanthanide ions, a luminescent center (Eu, Tb) for optical imaging purposes and Gd, whose magnetic properties are particularly beneficial in magnetic resonance imaging (MRI) asa contrast agent. Together, these two features allow for multimodal imaging, useful in the study and diagnosis of disease. Under identical reaction conditions, two different compounds were formed upon changing the identity of the optically active lanthanide metal ion. Compound 1 ([EuGd(BTC)2(H2O)12]) emerged as a one dimensional coordination polymer, increasing in size with reaction time; while compound 2 ([TbGd(BTC)2(H2O)2]n•2DMF) emerged as a three dimensionalframework, decreasing in size with time. Both compounds displayed vibrant luminescence upon UV excitation, indicating potential as bioimaging agents

    Synthesis and characterisation of peroxypinic acids as proxies for highly oxygenated molecules (HOMs) in secondary organic aerosol

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    Peroxy acids were recently found to be involved in new particle formation in the atmosphere and could also substantially contribute towards particle toxicity. However, a lack of suitable analytical methods for the detection and characterisation of peroxy acids in the particle phase is currently hindering the quantitative investigation of their contribution to these important atmospheric processes. Further development of appropriate techniques and relevant standards is therefore urgently needed. In this study, we synthesised three peroxypinic acids, developed a liquid chromatography separation method and characterised them with tandem mass spectrometry. The observed fragmentation patterns clearly distinguish the different peroxypinic acids from both the acid and each other, showing several neutral losses previously already observed for other peroxy acids. Both monoperoxypinic acids were found to be present in secondary organic aerosol generated from ozonolysis of α-pinene in laboratory experiments. The yield of monoperoxypinic acid formation was not influenced by humidity. Monoperoxypinic acid quickly degrades on the filter, with about 60% lost within the first 5h. This fast degradation shows that time delays in traditional off-line analysis will likely lead to severe underestimates of peroxy compound concentrations in ambient particles.Sarah S. Steimer acknowledges funding support from the Swiss National Science Foundation (project no. 162258). Funding by the European Research Council (ERC starting grant 279405) and the European Union’s Horizon 2020 research and innovation programme through the EUROCHAMP-2020 Infrastructure Activity under grant agreement no. 730997 is acknowledged

    MosChito rafts as effective and eco-friendly tool for the delivery of a Bacillus thuringiensis-based insecticide to Aedes albopictus larvae

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    Adult mosquito females, through their bites, are responsible for the transmission of different zoonotic pathogens. Although adult control represents a pillar for the prevention of disease spread, larval control is also crucial. Herein we characterized the effectiveness of a suitable tool, named "MosChito raft", for the aquatic delivery of a Bacillus thuringiensis var. israelensis (Bti) formulate, a bioinsecticide active by ingestion against mosquito larvae. MosChito raft is a floating tool composed by chitosan cross-linked with genipin in which a Bti-based formulate and an attractant have been included. MosChito rafts (i) resulted attractive for the larvae of the Asian tiger mosquito Aedes albopictus, (ii) induced larval mortality within a few hours of exposure and, more importantly, (iii) protected the Bti-based formulate, whose insecticidal activity was maintained for more than one month in comparison to the few days residual activity of the commercial product. The delivery method was effective in both laboratory and semi-field conditions, demonstrating that MosChito rafts may represent an original, eco-based and user-friendly solution for larval control in domestic and peri-domestic aquatic habitats such as saucers and artificial containers in residential or urban environments

    Role of the supine lateral radiograph of the spine in vertebroplasty for osteoporotic vertebral compression fracture: a prospective study

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    <p>Abstract</p> <p>Background</p> <p>Severely collapsed vertebral compression fracture (VCF) is usually considered as a contraindication for vertebroplasty because of critically decreased vertebral height (less than one-third the original height). However, osteoporotic VCF can possess dynamic mobility with intravertebral cleft (IVC), which can be demonstrated on supine lateral radiographs (SuLR) and standing lateral radiographs (StLR). The purposes of this study were to: (1) evaluate the efficacy of SuLR to detect IVCs and assess the intravertebral mobility in VCFs, and (2) evaluate the short-term results of vertebroplasty in severely collapsed VCFs with IVCs.</p> <p>Methods</p> <p>We enrolled 37 patients with 40 symptomatic osteoporotic VCFs for vertebroplasty; 11 had severely collapsed VCFs with concurrent IVCs detected on the SuLR, the others had not-severely collapsed VCFs. A preoperative StLR, SuLR, magnetic resonance imaging (MRI), and postoperative StLR were taken from all patients. Radiographs were digitized to calculate vertebral body morphometrics including vertebral height ratio and Cobb's kyphotic angle. The intensity of the patient's pain was assessed by the visual analogue scale (VAS) on the day before operation and 1 day, 1 month, and 4 months after operation. The patient's VAS scores and image measurement results were assessed with the paired <it>t</it>-test and Pearson correlation tests; Mann-Whitney U test was used for VAS subgroup comparison. Significance was defined as <it>p </it>< 0.05.</p> <p>Results</p> <p>IVCs in patients with not-severely collapsed VCFs were detected in 21 vertebrae (72.4%) by MRI, in 15 vertebrae (51.7%) by preoperative SuLR, and in 7 vertebrae (24.1%) by preoperative StLR. Using the MRI as a gold standard to detect IVCs, SuLR exhibit a sensitivity of 0.71 as compared to StLR that yield a sensitivity of 0.33. In patients with VCFs with IVCs detected on SuLR, the average of the postoperative restoration in vertebral height ratio was significantly higher than that in those without IVCs (17.1% vs. 6.4%). There was no statistical difference in the VAS score between severely collapsed VCFs with IVCs detected on SuLR and not-severely collapsed VCFs at any follow-up time point.</p> <p>Conclusions</p> <p>The SuLR efficiently detects an IVC in VCF, which indicates a better vertebral height correction after vertebroplasty compared to VCF without IVC. Before performing a costly MRI, SuLR can identify more IVCs than StLR in patients with severely collapsed VCFs, whom may become the candidates for vertebroplasty.</p

    Synthesis and characterisation of peroxypinic acids as proxies for highly oxygenated molecules (HOMs) in secondary organic aerosol

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    Peroxy acids were recently found to be involved in new particle formation in the atmosphere and could also substantially contribute towards particle toxicity. However, a lack of suitable analytical methods for the detection and characterisation of peroxy acids in the particle phase is currently hindering the quantitative investigation of their contribution to these important atmospheric processes. Further development of appropriate techniques and relevant standards is therefore urgently needed. In this study, we synthesised three peroxypinic acids, developed a liquid chromatography separation method and characterised them with tandem mass spectrometry. The observed fragmentation patterns clearly distinguish the different peroxypinic acids from both the acid and each other, showing several neutral losses previously already observed for other peroxy acids. Both monoperoxypinic acids were found to be present in secondary organic aerosol generated from ozonolysis of α-pinene in laboratory experiments. The yield of monoperoxypinic acid formation was not influenced by humidity. Monoperoxypinic acid quickly degrades on the filter, with about 60&thinsp;% lost within the first 5&thinsp;h. This fast degradation shows that time delays in traditional off-line analysis will likely lead to severe underestimates of peroxy compound concentrations in ambient particles.</p

    Implantation eines Carotisstents zur Vermeidung einer arteriellen Arrosionsblutung

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    Laryngeal mask airway: Is the management of neonates requiring positive pressure ventilation at birth changing?

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    Objective: To evaluate the impact of the laryngeal mask airway (LMA) on neonatal resuscitation policy. Design: We analyzed retrospectively the records of neonates requiring positive pressure ventilation (PPV) at birth before (1996) and after (2000) the introduction of the LMA into our delivery suites. In addition, the outcome of neonates treated with the LMA was compared with that of neonates matched for gestational age and mode of delivery who were resuscitated using a face mask. Results: During the year 2000, 95 out of 380 (25%) resuscitated neonates were treated with the LMA. The LMA was effective in 94 out of 95 (99%) of these infants. Over the same period, the percentage of neonates receiving tracheal intubation (TI) at birth (34%) was significantly reduced compared with the figure for 1996 (67%). There were no reported complications associated with the use of the LMA. Seventy-four out of the 95 neonates treated with the LMA were considered suitable for matching for gestational age and mode of delivery with 74 neonates treated with a face mask. No differences were found between the two groups for birth weight, Apgar scores, need for tracheal intubation, need for admission to the Neonatal Intensive Care Unit (NICU), primary diagnosis at discharge and primary outcomes. The LMA provided effective ventilation in four neonates in whom the face mask failed. Conclusions: The LMA is changing neonatal resuscitation practice in our Institution. Our data suggest that it is a safe and useful alternative method for respiratory support in neonates requiring PPV at birth, which merits further study. \ua9 2004 Elsevier Ireland Ltd. All rights reserved

    ASSORBIMENTO DELLA VITAMINA B12 DOPO BYPASS BILIOPANCREATICO PER L'OBESITA'.

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