809 research outputs found
Redox-responsive inorganic fluorescent nanoprobes for serodiagnosis and bioimaging
Redox reactions play fundamental roles in life and are at the core of metabolism. Thus, observing and quantifying these reactions is crucial for diagnostics and therapy. Recent advances in inorganic fluorescent nanoprobes have revolutionized the field, enabling in vitro diagnostics by providing reliable tools for real-time, quantitative determination of redox biomolecule levels in biological samples and cells. Due to their high stability, these probes are also widely used in bioimaging, providing real-time information for in vivo diagnostics and guiding treatment of diseases associated with redox biomolecules. This review explores the diverse landscape of inorganic fluorescent nanoprobes designed for the detection of biologically relevant reactive oxygen and nitrogen species. The discussion is divided into several sections, each focusing on nanoprobes tailored for specific oxidative species. The impact of tailored nanoprobes in diagnostics and imaging-guided treatment depends on their chemical composition, surface property, and fluorescence mechanism. The discussions highlight the current strengths and weaknesses, which will help to design more efficient redox-responsive inorganic fluorescent nanoprobes in the future
The three-body recombination of a condensed Bose gas near a Feshbach resonance
In this paper, we study the three-body recombination rate of a homogeneous
dilute Bose gas with a Feshbach resonance at zero temperature. The ground state
and excitations of this system are obtained. The three-body recombination in
the ground state is due to the break-up of an atom pair in the quantum
depletion and the formation of a molecule by an atom from the broken pair and
an atom from the condensate. The rate of this process is in good agreement with
the experiment on Na in a wide range of magnetic fields.Comment: 10 pages, 2 figures, to be published in Phys. Rev.
Crystallization-based downstream processing of ω-transaminase- and amine dehydrogenase-catalyzed reactions
Biocatalytic synthesis is a powerful and frequently chosen method for the production of chiral amines. Unfortunately, these biocatalytic reactions often result in complex mixtures, bearing many components aside from the main product amine such as residual co-substrates, co-products, cofactors and buffer salts. This issue typically requires an additional effort during downstream processing towards the isolation of the desired chiral amine. For instance, transaminase- and amine dehydrogenase-catalyzed reactions, which often use high surpluses of amine or ammonia co-substrates, face complications in removing the residual amine donor or unreacted substrate and salts from the isolated amine products, thus complicating and increasing the costs of the process of product isolation and purification. This study explores the selective removal of chiral amines from model amine transaminase and amine dehydrogenase-catalyzed reactions via a salt-based specific crystallization step. The product amine is precipitated directly in one step from the reaction mixture as a product ammonium salt, which can easily be filtered from the reaction mixture, while the other reactants remain unchanged in solution for potential re-use.</p
Anti-CTLA-4 therapy for malignant mesothelioma
Immunotherapy is an emerging therapeutic strategy with a promising clinical outcome in some solid tumors, particularly metastatic melanoma. One approach to immunotherapy is immune checkpoint inhibitors, such as blockage of CTLA-4 and PD-1/PD-L1. This special report aims to describe the state of clinical trials of tremelimumab in patients with unresectable malignant mesothelioma (MM) in particular with regard to the clinical efficacy, safety and tolerability. Criticism and perspective of this treatment are also discussed. Biological and clinical considerations rule out the use of tremelimumab as single agent for MM and, more generally, the use of immune checkpoint inhibitors for MM is still largely questionable and not supported by evidences
Copper deficiency-associated myelopathy in cryptogenic hyperzincemia: A case report
Copper deficiency syndrome is an underestimated cause of posterior myelitis. We describe the case of a 41-year-old woman, who developed a subacute ataxic paraparesis associated with low back pain. Her 3T spine MRI showed a thin hyperintense FS-Echo T2 longitudinally extensive lesion involving the posterior columns of the cervical cord (from C2 to C6). An extensive diagnostic work-up excluded other causes of myelopathy and blood tests pointed out hypocupremia and mild hyperzincemia. Patients affected by this rare form of oligoelement deficiency typically develop progressive posterior column dysfunction with sensory ataxia and spasticity, sometimes associated with sensori-motor polyneuropathy. Clinical and radiological characteristics of posterior myelopathy due to copper deficiency are briefly reviewed. Physicians should be aware of this condition since a prompt introduction of copper supplementation can avoid progression of the neurological damage. (www.actabiomedica.it)
Simple, affordable evaporative cooler to reduce food loss in developing countries
Cooling systems in developing countries have effects on health, hunger, food waste and the environment. Refrigerators are the best method for preserving food, but they are expensive, complex, energy-consuming, unsustainable for some countries. Therefore, there is an interest in simple, cheaper alternatives: evaporative coolers allow to raise the air humidity while reducing its temperature. The purpose of this work is to design and validate an evaporative cooling system that will allow storage of perishables, such as fruits and greens, extending their shelf-life. Our case study is focused on Senegal’s Tambacounda region. To crack the Senegalese market, an innovative business model has been thought, allowing the low-cost distribution of the cooler to the local population
Continuous Flow Biocatalytic Reductive Amination by Co-Entrapping Dehydrogenases with Agarose Gel in a 3D-Printed Mould Reactor
Herein, we show how the merge of biocatalysis with flow chemistry aided by 3D-printing technologies can facilitate organic synthesis. This concept was exemplified for the reductive amination of benzaldehyde catalysed by co-immobilised amine dehydrogenase and formate dehydrogenase in a continuous flow micro-reactor. For this purpose, we investigated enzyme co-immobilisation by covalent binding, or ion-affinity binding, or entrapment. Entrapment in an agarose hydrogel turned out to be the most promising solution for this biocatalytic reaction. Therefore, we developed a scalable and customisable approach whereby an agarose hydrogel containing the co-entrapped dehydrogenases was cast in a 3D-printed mould. The reactor was applied to the reductive amination of benzaldehyde in continuous flow over 120 h and afforded 47 % analytical yield and a space-time yield of 7.4 g L day−1 using 0.03 mol% biocatalysts loading. This work also exemplifies how rapid prototyping of enzymatic reactions in flow can be achieved through 3D-printing technology
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