3Dmodeling of the exocrine pancreatic unit using tomographic volumetric bioprinting.

Pancreatic ductal adenocarcinoma (PDAC) is the most common type of pancreatic cancer, a leading cause of cancer-related deaths globally. Initial lesions of PDAC develop within the exocrine pancreas' functional units, with tumor progression driven by interactions between PDAC and stromal cells. Effective therapies require anatomically and functionally relevanthuman models of the pancreatic cancer microenvironment.

Multi-photon polymerization using upconversion nanoparticles for tunable feature-size printing.

The recent development of light-based 3D printing technologies has marked a turning point in additive manufacturing. Through photopolymerization, liquid resins can be solidified into complex objects. Usually, the polymerization is triggered by exciting a photoinitiator with ultraviolet (UV) or blue light.

From 3D to 2D and back again.

The prospect of massive parallelism of optics enabling fast and low energy cost operations is attracting interest for novel photonic circuits where 3-dimensional (3D) implementations have a high potential for scalability. Since the technology for data input-output channels is 2-dimensional (2D), there is an unavoidable need to take 2D-nD transformations into account. Similarly, the 3D-2D and its reverse transformations are also tackled in a variety of fields such as optical tomography, additive manufacturing, and 3D optical memories.

NIR Light-Mediated Photocuring of Adhesive Hydrogels for Noninvasive Tissue Repair Upconversion Optogenesis.

The surgical treatments of injured soft tissues lead to further injury due to the use of sutures or the surgical routes, which need to be large enough to insert biomaterials for repair. In contrast, the use of low viscosity photopolymerizable hydrogels that can be inserted with thin needles represents a less traumatic treatment and would therefore reduce the severity of iatrogenic injury. However, the delivery of light to solidify the inserted hydrogel precursor requires a direct access to it, which is mostly invasive.

Physics-based neural network for non-invasive control of coherent light in scattering media.

Optical imaging through complex media, such as biological tissues or fog, is challenging due to light scattering. In the multiple scattering regime, wavefront shaping provides an effective method to retrieve information; it relies on measuring how the propagation of different optical wavefronts are impacted by scattering. Based on this principle, several wavefront shaping techniques were successfully developed, but most of them are highly invasive and limited to proof-of-principle experiments.

Controlling Light in Scattering Materials for Volumetric Additive Manufacturing.

3D printing has revolutionized the manufacturing of volumetric components and structures in many areas. Several fully volumetric light-based techniques have been recently developed thanks to the advent of photocurable resins, promising to reach unprecedented short print time (down to a few tens of seconds) while keeping a good resolution (around 100 μm). However, these new approaches only work with homogeneous and relatively transparent resins so that the light patterns used for photo-polymerization are not scrambled along their propagation.

Non-invasive chemically selective energy delivery and focusing inside a scattering medium guided by Raman scattering.

Raman scattering is a chemically selective probing mechanism with diverse applications in industry and clinical settings. Yet, most samples are optically opaque limiting the applicability of Raman probing at depth. Here, we demonstrate chemically selective energy deposition behind a scattering medium by combining prior information on the chemical's spectrum with the measurement of a spectrally resolved Raman speckle as a feedback mechanism for wavefront shaping.

Large field-of-view non-invasive imaging through scattering layers using fluctuating random illumination.

Non-invasive optical imaging techniques are essential diagnostic tools in many fields. Although various recent methods have been proposed to utilize and control light in multiple scattering media, non-invasive optical imaging through and inside scattering layers across a large field of view remains elusive due to the physical limits set by the optical memory effect, especially without wavefront shaping techniques. Here, we demonstrate an approach that enables non-invasive fluorescence imaging behind scattering layers with field-of-views extending well beyond the optical memory effect.

Spectrally resolved point-spread-function engineering using a complex medium.

Propagation of an ultrashort pulse of light through strongly scattering media generates an intricate spatio-spectral speckle that can be described by means of the multi-spectral transmission matrix (MSTM). In conjunction with a spatial light modulator, the MSTM enables the manipulation of the pulse leaving the medium; in particular focusing it at any desired spatial position and/or time. Here, we demonstrate how to engineer the point-spread-function of the focused beam both spatially and spectrally, from the measured MSTM.

Non-invasive focusing and imaging in scattering media with a fluorescence-based transmission matrix.

In biological microscopy, light scattering represents the main limitation to image at depth. Recently, a set of wavefront shaping techniques has been developed in order to manipulate coherent light in strongly disordered materials. The Transmission Matrix approach has shown its capability to inverse the effect of scattering and efficiently focus light.

Fast multiphoton light-sheet microscopy with optimal pulse frequency.

Improving the imaging speed of multiphoton microscopy is an active research field. Among recent strategies, light-sheet illumination holds distinctive advantages for achieving fast imaging . However, photoperturbation in multiphoton light-sheet microscopy remains poorly investigated.

The Future of Origin of Life Research: Bridging Decades-Old Divisions.

Research on the origin of life is highly heterogeneous. After a peculiar historical development, it still includes strongly opposed views which potentially hinder progress. In the 1st Interdisciplinary Origin of Life Meeting, early-career researchers gathered to explore the commonalities between theories and approaches, critical divergence points, and expectations for the future.

Melanin-based coloration and host-parasite interactions under global change.

The role of parasites in shaping melanin-based colour polymorphism, and the consequences of colour polymorphism for disease resistance, remain debated. Here we review recent evidence of the links between melanin-based coloration and the behavioural and immunological defences of vertebrates against their parasites. First we propose that (1) differences between colour morphs can result in variable exposure to parasites, either directly (certain colours might be more or less attractive to parasites) or indirectly (variations in behaviour and encounter probability).

Parallel and nonparallel behavioural evolution in response to parasitism and predation in Trinidadian guppies.

Natural enemies such as predators and parasites are known to shape intraspecific variability of behaviour and personality in natural populations, yet several key questions remain: (i) What is the relative importance of predation vs. parasitism in shaping intraspecific variation of behaviour across generations? (ii) What are the contributions of genetic and plastic effects to this behavioural divergence? (iii) And to what extent are responses to predation and parasitism repeatable across independent evolutionary lineages? We addressed these questions using Trinidadian guppies (Poecilia reticulata) (i) varying in their exposure to dangerous fish predators and Gyrodactylus ectoparasites for (ii) both wild-caught F0 and laboratory-reared F2 individuals and coming from (iii) multiple independent evolutionary lineages (i.e.

[Impact on the healthcare team and parents of the type of cardiorespiratory monitoring during phototherapy].

Introduction: Neonatal jaundice is treated with phototherapy and requires continuous cardiorespiratory monitoring, which can induce parental anxiety. Within a very short time, parents receive the announcement of the diagnosis and of the need for a treatment in another unit with a new team of caregivers.

Objective: To evaluate parents' anxiety and their feelings concerning the location of treatment concerning cardiorespiratory monitoring equipment (wired vs Wi-Fi wireless monitoring equipment) and treatment location (neonatology vs maternity wards) during a phototherapy treatment in the neonatology unit, located in the maternity wards.

[Skin-to-skin care in the delivery room: impact of SpO2 monitoring].

Background: Skin-to-skin care in the delivery room increases mother-newborn bonding, reduces the newborn's stress level, and facilitates breastfeeding. However, a few reports of life-threatening events in newborn infants during skin-to-skin care have prompted suggestions that SpO2 monitoring may be of value in the delivery room. The present study compared SpO2 monitoring with standard clinical practices during skin-to-skin care in the delivery room.

ADAR1 enhances HTLV-1 and HTLV-2 replication through inhibition of PKR activity.

Background: The role of innate immunity in general and of type I interferon (IFN-I) in particular in HTLV-1 pathogenesis is still a matter of debate. ADAR1-p150 is an Interferon Stimulated Gene (ISG) induced by IFN-I that can edit viral RNAs. We therefore investigated whether it could play the role of an anti-HTLV factor.

Specificity determinants for lysine incorporation in Staphylococcus aureus peptidoglycan as revealed by the structure of a MurE enzyme ternary complex.

Formation of the peptidoglycan stem pentapeptide requires the insertion of both L and D amino acids by the ATP-dependent ligase enzymes MurC, -D, -E, and -F. The stereochemical control of the third position amino acid in the pentapeptide is crucial to maintain the fidelity of later biosynthetic steps contributing to cell morphology, antibiotic resistance, and pathogenesis. Here we determined the x-ray crystal structure of Staphylococcus aureus MurE UDP-N-acetylmuramoyl-L-alanyl-D-glutamate:meso-2,6-diaminopimelate ligase (MurE) (E.

MurD enzymes from different bacteria: evaluation of inhibitors.

D-Glutamic acid-adding enzyme (MurD ligase) catalyses the addition of D-glutamic acid to UDP-N-acetylmuramoyl-L-alanine, an essential cytoplasmic step in the pathway for bacterial cell-wall peptidoglycan synthesis. As such, it represents an important antibacterial drug-discovery target enzyme. Recently, several series of compounds have been synthesised and found to inhibit MurD from Escherichia coli, the best one having an IC(50) value of 8 μM.

Purification and biochemical characterization of Mur ligases from Staphylococcus aureus.

The Mur ligases (MurC, MurD, MurE and MurF) catalyze the stepwise synthesis of the UDP-N-acetylmuramoyl-pentapeptide precursor of peptidoglycan. The murC, murD, murE and murF genes from Staphylococcus aureus, a major pathogen, were cloned and the corresponding proteins were overproduced in Escherichia coli and purified as His(6)-tagged forms. Their biochemical properties were investigated and compared to those of the E.

A secondary metabolite acting as a signalling molecule controls Pseudomonas entomophila virulence.

Pseudomonas entomophila is an entomopathogenic bacterium that is lethal to Drosophila melanogaster within 1-2 days of ingestion of high doses. Flies orally infected with P. entomophila rapidly succumb despite the induction of both local and systemic immune responses.

The elucidation of the structure of Thermotoga maritima peptidoglycan reveals two novel types of cross-link.

Thermotoga maritima is a Gram-negative, hyperthermophilic bacterium whose peptidoglycan contains comparable amounts of L- and D-lysine. We have determined the fine structure of this cell-wall polymer. The muropeptides resulting from the digestion of peptidoglycan by mutanolysin were separated by high-performance liquid chromatography and identified by amino acid analysis after acid hydrolysis, dinitrophenylation, enzymatic determination of the configuration of the chiral amino acids, and mass spectrometry.

Discovery of new inhibitors of the bacterial peptidoglycan biosynthesis enzymes MurD and MurF by structure-based virtual screening.

The ATP-dependent Mur ligases (MurC, MurD, MurE and MurF) successively add L-Ala, D-Glu, meso-A(2)pm or L-Lys, and D-Ala-D-Ala to the nucleotide precursor UDP-MurNAc, and they represent promising targets for antibacterial drug discovery. We have used the molecular docking programme eHiTS for the virtual screening of 1990 compounds from the National Cancer Institute 'Diversity Set' on MurD and MurF. The 50 top-scoring compounds from screening on each enzyme were selected for experimental biochemical evaluation.

Synthesis and biological evaluation of N-acylhydrazones as inhibitors of MurC and MurD ligases.

The Mur ligases have an essential role in the intracellular biosynthesis of bacterial peptidoglycan, and they represent attractive targets for the design of novel antibacterials. A series of compounds with an N-acylhydrazone scaffold were synthesized and screened for inhibition of the MurC and MurD enzymes from Escherichia coli. Compounds with micromolar inhibitory activities against both MurC and MurD were identified, and some of them also showed antibacterial activity.

Cytoplasmic steps of peptidoglycan biosynthesis.

The biosynthesis of bacterial cell wall peptidoglycan is a complex process that involves enzyme reactions that take place in the cytoplasm (synthesis of the nucleotide precursors) and on the inner side (synthesis of lipid-linked intermediates) and outer side (polymerization reactions) of the cytoplasmic membrane. This review deals with the cytoplasmic steps of peptidoglycan biosynthesis, which can be divided into four sets of reactions that lead to the syntheses of (1) UDP-N-acetylglucosamine from fructose 6-phosphate, (2) UDP-N-acetylmuramic acid from UDP-N-acetylglucosamine, (3) UDP-N-acetylmuramyl-pentapeptide from UDP-N-acetylmuramic acid and (4) D-glutamic acid and dipeptide D-alanyl-D-alanine. Recent data concerning the different enzymes involved are presented.