15 research outputs found
RNA Identification and Detection of Nucleic Acids as Aerosols in Air Samples by Means of Photon and Electron Interactions
This study presents a methodology to reveal traces of viral particles, as
aerosol with known chemical and molecular structure, in a sample by means of
photon and electron interactions. The method is based on Monte Carlo
simulations and on the analysis of photon-electron fluxes-spectra through
energy channels counts as a function of different aerosol viral concentrations
in the air sample and looking at the peculiar photon/electron interactions with
the potential abnormal atomic hydrogen (H), oxygen (O), carbon (C), and
phosphorus (P) compositions present in the air sample as a function of living
and nonliving matter with PO4 group RNA/DNA strands in a cluster configuration.Comment: 21 pages, 22 figure
Efficient pilot-scale synthesis of the key cefonicid intermediate at room temperature
Abstract
Cefonicid is a common second-generation cephalosporin, and the 7-amino-3-[sulphomethyl-1-H-tetrazol-5-yl-thiomethyl]-3-cephem-4-carboxylate monosodium salt is a key synthetic intermediate in its preparation. Despite the considerable international demand for this antibiotic, its preparation is hampered by low synthetic yield, long reaction time, and time-consuming industrial filtration over charcoal after the purification step. In the context of the industrial production of pharmaceutical intermediates, in which the balance between streamlining and enhancing productivity is necessary in order to compete in the global active pharmaceutical ingredients (API) market, we have investigated an efficient and practical procedure for the synthesis of a key cefonicid intermediate that features a telescopic route whose synthetic steps are all performed at room temperature; from the displacement of the acetoxy group with boron trifluoride to crystallization without treatment with charcoal. In other words, a simpler, scalable, cost-effective and energy-saving protocol is herein reported as a means of moving towards commercial manufacturing. The optimization of the process parameters and the industrial-scale impact assessment should pave the way for industrialization
Towards Antibiotic Synthesis in Continuous-Flow Processes
Continuous-flow chemistry has become a mainstream process and a notable trend among emerging technologies for drug synthesis. It is routinely used in academic and industrial laboratories to generate a wide variety of molecules and building blocks. The advantages it provides, in terms of safety, speed, cost efficiency and small-equipment footprint compared to analog batch processes, have been known for some time. What has become even more important in recent years is its compliance with the quality objectives that are required by drug-development protocols that integrate inline analysis and purification tools. There can be no doubt that worldwide government agencies have strongly encouraged the study and implementation of this innovative, sustainable and environmentally friendly technology. In this brief review, we list and evaluate the development and applications of continuous-flow processes for antibiotic synthesis. This work spans the period of 2012–2022 and highlights the main cases in which either active ingredients or their intermediates were produced under continuous flow. We hope that this manuscript will provide an overview of the field and a starting point for a deeper understanding of the impact of flow chemistry on the broad panorama of antibiotic synthesis
Breaking Preconceptions: Thin Section Petrography For Ceramic Glaze Microstructures
During the last thirty years, microstructural and technological studies on ceramic glazes have been essentially carried out through the use of Scanning Electron Microscopy (SEM) combined with energy dispersive X-ray analysis (EDX). On the contrary, optical microscopy (OM) has been considered of limited use in solving the very complex and fine-scale microstructures associated with ceramic glazes. As the crystallites formed inside glazes are sub- and micrometric, a common misconception is that it is not possible to study them by OM. This is probably one of the reasons why there are no available articles and textbooks and even no visual resources for describing and characterizing the micro-crystallites formed in glaze matrices. A thin section petrography (TSP) for ceramic glaze microstructures does not exist yet, neither as a field of study nor conceptually. In the present contribution, we intend to show new developments in the field of ceramic glaze petrography, highlighting the potential of OM in the microstructural studies of ceramic glazes using petrographic thin sections. The outcomes not only stress the pivotal role of thin section petrography for the study of glaze microstructures but also show that this step should not be bypassed to achieve reliable readings of the glaze microstructures and sound interpretations of the technological procedures. We suggest the adoption by the scientific community of an alternative vision on glaze microstructures to turn thin section petrography for glaze microstructures into a new specialized petrographic discipline. Such an approach, if intensively developed, has the potential to reduce the time and costs of scientific investigations in this specific domain. In fact, it can provide key reference data for the identification of the crystallites in ceramic glazes, avoiding the repetition of exhaustive protocols of expensive integrated analyses
Use, tolerability, benefits and side effects of orthotic devices in Charcot-Marie-Tooth disease
Background: Shoe inserts, orthopaedic shoes, ankle-foot orthoses (AFOs) are important devices in Charcot-Marie-Tooth disease (CMT) management, but data about use, benefits and tolerance are scanty. Methods: We administered to Italian CMT Registry patients an online ad hoc questionnaire investigating use, complications and perceived benefit/tolerability/emotional distress of shoe inserts, orthopaedic shoes, AFOs and other orthoses/aids. Patients were also asked to fill in the Quebec User Evaluation of Satisfaction with assistive Technology questionnaire, rating satisfaction with currently used AFO and related services. Results: We analysed answers from 266 CMT patients. Seventy per cent of subjects were prescribed lower limb orthoses, but 19% did not used them. Overall, 39% of subjects wore shoe inserts, 18% orthopaedic shoes and 23% AFOs. Frequency of abandonment was high: 24% for shoe inserts, 28% for orthopaedic shoes and 31% for AFOs. Complications were reported by 59% of patients and were more frequently related to AFOs (69%). AFO users experienced greater emotional distress and reduced tolerability as compared with shoe inserts (p<0.001) and orthopaedic shoes (p=0.003 and p=0.045, respectively). Disease severity, degree of foot weakness, customisation and timing for customisation were determinant factors in AFOs' tolerability. Quality of professional and follow-up services were perceived issues. Conclusions: The majority of CMT patients is prescribed shoe inserts, orthopaedic shoes and/or AFOs. Although perceived benefits and tolerability are rather good, there is a high rate of complications, potentially inappropriate prescriptions and considerable emotional distress, which reduce the use of AFOs. A rational, patient-oriented and multidisciplinary approach to orthoses prescription must be encouraged
Cefonicid Benzathine Salt: A Convenient, Lean, and High-Performance Protocol to Make an Old Cephalosporin Shine
Cefonicid is a second-generation cephalosporin sold under the brand name Sintocef™. It is an injectable drug obtained via a freeze-drying process and is also available for oral preparations. The high-quality standard required is very challenging to satisfy, and current production protocols are characterized by steps that are lengthy and cumbersome, making the product unattractive for the international market. Industrial R&D is constantly working on the process optimization for API synthesis, with the aim of increasing productivity and decreasing production costs and waste. We herein report a new and efficient method for the synthesis of the cefonicid benzathine salt that provides a good yield and high product stability. The double-nucleophilic and lipophilic nature of N′,N″-dibenzylethylene diacetate enables the deformylation of the OH-protected group on the mandelic moiety and also enables product crystallization to occur. We demonstrate that the formyl group in the peculiar position has high reactivity, promoting an amidation reaction that deprotects a hydroxy group and generates a new C-N bond in the reaction by-product. Several amines and OH-protected groups have been studied, but none were able to replicate the excellent results of benzathine diacetate
Towards Antibiotic Synthesis in Continuous-Flow Processes
Continuous-flow chemistry has become a mainstream process and a notable trend among emerging technologies for drug synthesis. It is routinely used in academic and industrial laboratories to generate a wide variety of molecules and building blocks. The advantages it provides, in terms of safety, speed, cost efficiency and small-equipment footprint compared to analog batch processes, have been known for some time. What has become even more important in recent years is its compliance with the quality objectives that are required by drug-development protocols that integrate inline analysis and purification tools. There can be no doubt that worldwide government agencies have strongly encouraged the study and implementation of this innovative, sustainable and environmentally friendly technology. In this brief review, we list and evaluate the development and applications of continuous-flow processes for antibiotic synthesis. This work spans the period of 2012–2022 and highlights the main cases in which either active ingredients or their intermediates were produced under continuous flow. We hope that this manuscript will provide an overview of the field and a starting point for a deeper understanding of the impact of flow chemistry on the broad panorama of antibiotic synthesis
Breaking Preconceptions: Thin Section Petrography For Ceramic Glaze Microstructures
During the last thirty years, microstructural and technological studies on ceramic glazes have been essentially carried out through the use of Scanning Electron Microscopy (SEM) combined with energy dispersive X-ray analysis (EDX). On the contrary, optical microscopy (OM) has been considered of limited use in solving the very complex and fine-scale microstructures associated with ceramic glazes. As the crystallites formed inside glazes are sub- and micrometric, a common misconception is that it is not possible to study them by OM. This is probably one of the reasons why there are no available articles and textbooks and even no visual resources for describing and characterizing the micro-crystallites formed in glaze matrices. A thin section petrography (TSP) for ceramic glaze microstructures does not exist yet, neither as a field of study nor conceptually. In the present contribution, we intend to show new developments in the field of ceramic glaze petrography, highlighting the potential of OM in the microstructural studies of ceramic glazes using petrographic thin sections. The outcomes not only stress the pivotal role of thin section petrography for the study of glaze microstructures but also show that this step should not be bypassed to achieve reliable readings of the glaze microstructures and sound interpretations of the technological procedures. We suggest the adoption by the scientific community of an alternative vision on glaze microstructures to turn thin section petrography for glaze microstructures into a new specialized petrographic discipline. Such an approach, if intensively developed, has the potential to reduce the time and costs of scientific investigations in this specific domain. In fact, it can provide key reference data for the identification of the crystallites in ceramic glazes, avoiding the repetition of exhaustive protocols of expensive integrated analyses