Repurposing designed mutants: a valuable strategy for computer-aided laccase engineering – the case of POXA1b

The broad specificity of laccases, a direct consequence of their shallow binding site, makes this class of enzymes a suitable template to build specificity toward putative substrates. In this work, a computational methodology that accumulates beneficial interactions between the enzyme and the substrate in productive conformations is applied to oxidize 2,4-diamino-benzenesulfonic acid with POXA1b laccase. Although the experimental validation of two designed variants yielded negative results, most likely due to the hard oxidizability of the target substrate, molecular simulations suggest that a novel polar binding scaffold was designed to anchor negatively charged groups. Consequently, the oxidation of three such molecules, selected as representative of different classes of substances with different industrial applications, significantly improved. According to molecular simulations, the reason behind such an improvement lies in the more productive enzyme–substrate binding achieved thanks to the designed polar scaffold. In the future, mutant repurposing toward other substrates could be first carried out computationally, as done here, testing molecules that share some similarity with the initial target. In this way, repurposing would not be a mere safety net (as it is in the laboratory and as it was here) but rather a powerful approach to transform laccases into more efficient multitasking enzymes.This work was funded by INDOX (KBBE-2013-7-613549) European project and CTQ2013-48287-R Spanish National Project. V. G. and E. M. acknowledge Università degli Studi di Napoli and Generalitat de Catalunya for their respective predoctoral fellowships.Peer ReviewedPostprint (author's final draft

The anti-vegf(R) drug discovery legacy: Improving attrition rates by breaking the vicious cycle of angiogenesis in cancer

Resistance to anti-vascular endothelial growth factor (VEGF) molecules causes lack of response and disease recurrence. Acquired resistance develops as a result of genetic/epigenetic changes conferring to the cancer cells a drug resistant phenotype. In addition to tumor cells, tumor endothelial cells also undergo epigenetic modifications involved in resistance to anti-angiogenic therapies. The association of multiple anti-angiogenic molecules or a combination of anti-angiogenic drugs with other treatment regimens have been indicated as alternative therapeutic strategies to overcome resistance to anti-angiogenic therapies. Alternative mechanisms of tumor vasculature, including intussusceptive microvascular growth (IMG), vasculogenic mimicry, and vascular co-option, are involved in resistance to anti-angiogenic therapies. The crosstalk between angiogenesis and immune cells explains the efficacy of combining anti-angiogenic drugs with immune check-point inhibitors. Collectively, in order to increase clinical benefits and overcome resistance to anti-angiogenesis therapies, pan-omics profiling is key

Developing tools to promote culturally competent compassion, courage, and intercultural communication in healthcare

Background: Compassion is an important concept in healthcare, and in addition, care should be delivered in a culturally competent manner, taking into account the values, culture, and health beliefs of the individual. However, the training of nurses and other healthcare professionals may not adequately equip them to practice in a manner which is both compassionate and culturally competent. In this paper, we report on the development of three learning tools, designed to promote the skills and strengthen the capacity of nurses and healthcare professionals to provide culturally competent and compassionate care. Methods: The project involved the participation of six European countries in the development of three learning tools, covering culturally competent compassion, culturally competent courage, and intercultural communication. The principles which informed the methodology derive from the previous work on the Papadopoulos, Tilki and Taylor (PTT) model of transcultural nursing and cultural competence, and were also informed by the Intercultural Education of Nurses in Europe (IENE1 & IENE2) projects. Each partner country was required to produce one tool for each topic area, based on guidance provided by the project co-ordinator, leading to the development of eighteen tools in total. The tools were administered mainly to student nurses to test their feasibility. Results: The emerging tools contained important theoretical and practical components, whereby innovative learning methods and case studies were included. Student nurses enjoyed using the tools, and enjoyed their flexibility. The learning tools enabled students to become stimulated and to engage together leading to a positive learning experience. Discussion: The tools allow for a positive learning experience and reflection of good practice to take place. The flexibility and content of the tools allows for them to be of equal value to other healthcare professionals as well as nursing staff. Conclusion: The tools were initially utilised mainly with student nurses and were received with a positive response. Work is now in place to further implement the tools and evaluate the longer term effects among a range of healthcare professionals and service user health outcomes

Conversion of no/low value waste frying oils into biodiesel and polyhydroxyalkanoates

A sustainable bioprocess was developed for the valorization of a no/low value substrate, i.e. waste frying oils (WFOs) with high content of free fatty acids (FFAs), otherwise unsuitable for biodiesel production. The bioprocess was verified using both recombinant (Escherichia coli) and native (Pseudomonas resinovorans) polyhydroxyalkanoates (PHAs) producing cell factories. Microbial fermentation of WFOs provided a 2-fold advantage: i) the reduction of FFAs content resulting into an upgrading of the "exhausted waste oils" and ii) the production of a bio-based microbial polymer. Proper strain designing and process optimization allowed to achieve up to 1.5 g L-1 of medium chain length, mcl-PHAs, together with an efficient conversion (80% yield) of the treated WFO into biodiesel

Off-shell tachyon amplitudes: analyticity and projective invariance

We compute off-shell three- and four-tachyon amplitudes at tree level by using a prescription based on the requirement of projective invariance. In particular we show that the off-shell four-tachyon amplitude can be put in the same form as the corresponding on-shell one, exhibiting therefore the same analyticity properties. This is shown both for the bosonic and the fermionic string. The result obtained in the latter case can be extended to the off-shell four-tachyon amplitude in type 0 theory

TIBIO-FIBULAR BONE TRANSPOSITION FOR THE TREATMENT OF ONCOLOGICAL PERIPROSTHETIC INFECTION OF THE KNEE WITH MASSIVE BONE LOSS

Chronic periprosthetic joint infection (PJI) is one of the most relevant complications in orthopaedic surgery, especially in the case of limb reconstruction with megaprostheses after malignant tumoral resection. This is the report of a case of a 35-year-old patient, affected by a chronic PJI around a knee megaprosthesis implanted after the resection of an osteosarcoma of the distal femur. “En bloc” resection and limb reconstruction with an expandable megaprothesis of the knee were performed at the age of 5 years old (1989). PJI occurred after the definitive megaprosthesis implantation (2002), and became chronic over the years. In 2019, due to a massive recrudescence of the infection and the severe femoral bone loss, the patient underwent a wide intercalary resection and a thigh stump reconstruction by transposition of the fibula and the distal third of the tibia in order to avoid a hip disarticulation. Although complex, the proposed treatment allowed improved outcomes in a young patient with high function requests, justifying the global surgical invasiveness

On the Number of Cosmic Strings

The number of cosmic strings in the observable universe is relevant in determining the probability of detecting such cosmic defects through their gravitational signatures. In particular, we refer to the observation of gravitational lensing events and anisotropy in the CMB radiation induced by cosmic strings. In this paper, a simple method is adopted to obtain an approximate estimate of the number of segments of cosmic strings, crossing the particle horizon, which fall inside the observed part of the universe. We show that there is an appreciable difference in the expected number of segments which differentiates cosmic strings arising in Abelian Higgs and Nambu-Goto models, and that a different choice of setting for the cosmological model can lead to significant differences in the expected number of cosmic string segments. Of this number, the fraction realistically detectable may be considerably smaller.Comment: LaTex2e, 15 pages, 1 figure, 5 tables. Subject extended to other cosmological scenarios from Sect. 3 on hence, it follows a modification in the title; three tables and references added. Version to appear in MNRA

Eumelanin Graphene-Like Integration: The Impact on Physical Properties and Electrical Conductivity

The recent development of eumelanin pigment-based blends integrating "classical" organic conducting materials is expanding the scope of eumelanin in bioelectronics. Beyond the achievement of high conductivity level, another major goal lays in the knowledge and feasible control of structure/properties relationship. We systematically investigated different hybrid materials prepared by in situ polymerization of the eumelanin precursor 5,6-dihydroxyindole (DHI) in presence of various amounts of graphene-like layers. Spectroscopic studies performed by solid state nuclear magnetic resonance (ss-NMR), x-ray photoemission, and absorption spectroscopies gave a strong indication of the direct impact that the integration of graphene-like layers into the nascent polymerized DHI-based eumelanin has on the structural organization of the pigment itself, while infrared, and photoemission spectroscopies indicated the occurrence of negligible changes as concerns the chemical units. A tighter packing of the constituent units could represent a strong factor responsible for the observed improved electrical conductivity of the hybrid materials, and could be possible exploited as a tool for electrical conductivity tuning

Is nonangiogenesis a novel pathway for cancer progression? A study using 3-dimensional tumour reconstructions

The nonangiogenic lung tumour is characterized by neoplastic cells co-opting the pre-existent vasculature and filling the alveoli space. 3-Dimensional reconstruction of the tumour reveals that this particular tumour progresses without neovascularization and there is no major destruction of the lung's architectural integrity