146 research outputs found
Phillips CO-oxidation catalyts for long-lived CO2 lasers: Activity and initial characterization studies
Four different catalysts have been developed specifically for use in sealed carbon dioxide lasers. The catalysts have been designed to be low dusting, stable to shock and vibration, have high activity at low temperatures and have long active lifetimes. Measured global CO oxidation rates range from 1.4 to 2.2 cc CO converted per minute per gram of catalyst at ambient temperature. The catalysts also retain substantial activity at temperatures as low as -35 C. The Phillips laser catalysts are prepared in a variety of different shapes to meet the different pressure drop and gas flow profiles present in the many different styles of lasers. Each catalyst has been tested in sealed TEA lasers and has been shown to substantially increase the sealed life of the laser. Activity measurements made on the precious metal catalysts which were prepared with and without activity promoters showed that the promoter materials increase catalyst CO oxidation activity at least an order of magnitude at ambient temperature. Initial studies using H2 and CO chemisorption, X ray diffraction (XRD) and X ray photoelectron spectroscopy (XPS) have shown that the activity promoters do not significantly affect the precious metal crystallite size or the electronic structure around the precious metal. In addition, the formation or lack of formation of solid solutions between the precious metal and promoters has also been shown not to affect the activity of the promoted catalyst
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Micromixing and microchannel design: Vortex shape and entropy
This paper was presented at the 2nd Micro and Nano Flows Conference (MNF2009), which was held at Brunel University, West London, UK. The conference was organised by Brunel University and supported by the Institution of Mechanical Engineers, IPEM, the Italian Union of Thermofluid dynamics, the Process Intensification Network, HEXAG - the Heat Exchange Action Group and the Institute of Mathematics and its Applications.In very recent years microdevices, due to their potency in replacing large-scale conventional laboratory instrumentation, are becoming a fast and low cost technology for the treatment of several chemical and biological processes. In particular microfluidics has been massively investigated, aiming at improving the performance of chemical reactors. This is because of the fact that reaction is often an interface phenomenon where the greater the surface to volume ratio, the higher the reaction speed, and microscale mixing increases the interfacial area (in terms of mixing-induced-by-vortices generation). However, microfluidic systems suffer from the limitation that they are characterized mostly by very low Reynolds numbers, with the consequence that (i) they cannot take advantage from the turbulence mixing support, and (ii) viscosity hampers proper vortex detection. Therefore, the proper design of micro-channels (MCs) becomes essential. In this framework, several geometries have been proposed to induce mixing vortices in MCs. However a quantitative comparison between proposed geometries in terms of their passive mixing
potency can be done only after proper definition of vortex formation (topology, size) and mixing performance. The objective of this study is to test the ability of different fluid dynamic metrics in vortex
detection and mixing effectiveness in micromixers. This is done numerically solving different conditions for the flow in a classic passive mixer, a ring shaped MC. We speculate that MCs design could take advantage from fluidic metrics able to rank properly flow related mixing
Multifocal gastrointestinal angiosarcoma: A challenging diagnosis?
Angiosarcoma rarely involves the gastrointestinal tract. Herein, we describe the case of a 68-year-old man with haemoptysis and melena who was eventually diagnosed with multifocal angiosarcoma of the stomach, small bowel, lungs, and thyroid. The peculiarity was that the histological feature of the polypoid lesions removed at endoscopy was initially misinterpreted as benign hyperplastic polyps, whilst their neoplastic nature was clinically suspected only when the videocapsule endoscopy revealed the presence of multiple variable-sized nodules with apical erosion or active bleeding in the small bowel. Based on the very low incidence, diagnosis of angiosarcoma involving the gastrointestinal tract may be misinterpreted by both the endoscopist and pathologist
Genomic changes of chromosomes 8p23.1 and 1q21: Novel mutations in malignant mesothelioma
Introduction: Malignant mesothelioma is an aggressive malignancy of the thoracic cavity caused by prior asbestos exposure. In the peritoneum the mesothelioma is an extremely rare condition. In the present preliminary study, high-resolution array-comparative genomic hybridization (a-CGH) was performed to identify genetic imbalances in a series of malignant peritoneal mesothelioma cases. Materials and methods: Between 1990 and 2008, among the cases recorded in the Apulia Mesothelioma Register, we found 22 peritoneal mesothelioma cases. CGH-array was performed on samples from all patients. Results: The CGH-array analysis revealed multiple chromosomal imbalances. Interestingly, deletion at 8p23.1 was observed in 12 cases. Furthermore, another novel deletion at 1q21 was present in 11. Often, 1q21 and 8p23.1 losses were present in the same patient (7 cases). Losses of BAP1 and CDKN2A loci were not detected. Discussion: The region at 8p23.1 contains the beta-defensin gene cluster (DEF) and 1q21 contains ubiquitin conjugating enzyme E2 (UBE2Q1). We hypotesized that the loss of function of ubiquitination, as well as of the defensins, could play an important role in the initial development and subsequent progression of mesothelioma
Heritage: A phase III safety and efficacy trial of the proposed trastuzumab biosimilar Myl-1401O versus Herceptin
Background: Trastuzumab has revolutionized treatment of HER2+ breast cancer. Globally accessible alternatives are a critical need. We evaluated Myl-1401O, a proposed trastuzumab biosimilar, as treatment for HER2+ metastatic breast cancer (MBC), based on physicochemical analyses, nonclinical, pharmacokinetic and pharmacodynamic studies*. Methods: Heritage is a double-blind, randomized clinical trial designed to evaluate comparative efficacy and safety of Myl-1401O vs Herceptin. Eligible patients (pts) had ..
Effect of a Proposed Trastuzumab Biosimilar Compared With Trastuzumab on Overall Response Rate in Patients With ERBB2 (HER2)–Positive Metastatic Breast Cancer. A Randomized Clinical Trial
IMPORTANCE Treatment with the anti-ERBB2 humanized monoclonal antibody trastuzumab
and chemotherapy significantly improves outcome in patients with ERBB2 (HER2)–positive
metastatic breast cancer; a clinically effective biosimilar may help increase access to this therapy.
OBJECTIVE To compare the overall response rate and assess the safety of a proposed
trastuzumab biosimilar plus a taxane or trastuzumab plus a taxane in patients without prior
treatment for ERBB2-positive metastatic breast cancer.
DESIGN, SETTING, AND PARTICIPANTS Multicenter, double-blind, randomized, parallel-group,
phase 3 equivalence study in patients with metastatic breast cancer. From December 2012 to
August 2015, 500 patients were randomized 1:1 to receive a proposed biosimilar or
trastuzumab plus a taxane. Chemotherapy was administered for at least 24 weeks followed
by antibody alone until unacceptable toxic effects or disease progression occurred.
INTERVENTIONS Proposed biosimilar (n = 230) or trastuzumab (n = 228) with a taxane.
MAIN OUTCOMES AND MEASURES The primary outcome was week 24 overall response rate
(ORR) defined as complete or partial response. Equivalence boundaries were 0.81 to 1.24
with a 90% CI for ORR ratio (proposed biosimilar/trastuzumab) and −15% to 15% with a 95%
CI for ORR difference. Secondary outcome measures included time to tumor progression,
progression-free and overall survival at week 48, and adverse events.
RESULTS Among 500 women randomized, the intention-to-treat population included 458
women (mean [SD] age, 53.6 [11.11] years) and the safety population included 493 women.
The ORR was 69.6% (95% CI, 63.62%-75.51%) for the proposed biosimilar vs 64.0% (95% CI,
57.81%-70.26%) for trastuzumab. The ORR ratio (1.09; 90% CI, 0.974-1.211) and ORR difference
(5.53; 95% CI, −3.08 to 14.04) were within the equivalence boundaries. At week 48, there was no
statistically significant difference with the proposed biosimilar vs trastuzumab for time to tumor
progression (41.3% vs 43.0%; −1.7%; 95% CI, −11.1% to 6.9%), progression-free survival (44.3%
vs 44.7%; −0.4%; 95% CI, −9.4% to 8.7%), or overall survival (89.1% vs 85.1%; 4.0%; 95% CI,
−2.1% to 10.3%). In the proposed biosimilar and trastuzumab groups, 239 (98.6%) and 233
(94.7%) had at least 1 adverse event, the most common including neutropenia (57.5% vs 53.3%),
peripheral neuropathy (23.1% vs 24.8%), and diarrhea (20.6% vs 20.7%).
CONCLUSIONS AND RELEVANCE Among women with ERBB2-positive metastatic breast cancer
receiving taxanes, the use of a proposed trastuzumab biosimilar compared with trastuzumab
resulted in an equivalent overall response rate at 24 weeks. Further study is needed to assess
safety and long-term clinical outcome.
TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT02472964; EudraCT Identifier:
2011-001965-4
Deinococcus geothermalis: The Pool of Extreme Radiation Resistance Genes Shrinks
Bacteria of the genus Deinococcus are extremely resistant to ionizing radiation (IR), ultraviolet light (UV) and desiccation. The mesophile Deinococcus radiodurans was the first member of this group whose genome was completely sequenced. Analysis of the genome sequence of D. radiodurans, however, failed to identify unique DNA repair systems. To further delineate the genes underlying the resistance phenotypes, we report the whole-genome sequence of a second Deinococcus species, the thermophile Deinococcus geothermalis, which at its optimal growth temperature is as resistant to IR, UV and desiccation as D. radiodurans, and a comparative analysis of the two Deinococcus genomes. Many D. radiodurans genes previously implicated in resistance, but for which no sensitive phenotype was observed upon disruption, are absent in D. geothermalis. In contrast, most D. radiodurans genes whose mutants displayed a radiation-sensitive phenotype in D. radiodurans are conserved in D. geothermalis. Supporting the existence of a Deinococcus radiation response regulon, a common palindromic DNA motif was identified in a conserved set of genes associated with resistance, and a dedicated transcriptional regulator was predicted. We present the case that these two species evolved essentially the same diverse set of gene families, and that the extreme stress-resistance phenotypes of the Deinococcus lineage emerged progressively by amassing cell-cleaning systems from different sources, but not by acquisition of novel DNA repair systems. Our reconstruction of the genomic evolution of the Deinococcus-Thermus phylum indicates that the corresponding set of enzymes proliferated mainly in the common ancestor of Deinococcus. Results of the comparative analysis weaken the arguments for a role of higher-order chromosome alignment structures in resistance; more clearly define and substantially revise downward the number of uncharacterized genes that might participate in DNA repair and contribute to resistance; and strengthen the case for a role in survival of systems involved in manganese and iron homeostasis
Un metodo acustico per la determinazione della permeabilità di scaffolds utilizzati in medicina rigenerativa
Dispositivo microfluidico di mescolamento convettivo
L’invenzione consiste in un dispositivo atto a produrre mescolamento di fluidi su scala microscopica. Il dispositivo è caratterizzato da una geometria atta a promuovere la generazione di vortici che facilitano il mescolamento all’interno di un canale curvo in determinate condizioni di esercizio con una bassa perdita di carico.
Problema risolto: mescolamento convettivo passivo che favorisce reazioni chimiche a fronte di una bassa perdita di carico
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