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The degenerative effects of multiple sclerosis at the level of the vascular and neuronal networks in the central nervous system are currently the object of intensive investigation. Preclinical studies have demonstrated the efficacy of mesenchymal stem cell (MSC) therapy in experimental autoimmune encephalomyelitis (EAE), the animal model for multiple sclerosis, but the neuropathology of specific lesions in EAE and the effects of MSC treatment are under debate. Because conventional imaging techniques entail protocols that alter the tissues, limiting the reliability of the results, we have used non-invasive X-ray phase-contrast tomography to obtain an unprecedented direct 3D characterization of EAE lesions at micro-to-nano scales, with simultaneous imaging of the vascular and neuronal networks. We reveal EAE-mediated alterations down to the capillary network. Our findings shed light on how the disease and MSC treatment affect the tissues, and promote X-ray phase-contrast tomography as a powerful tool for studying neurovascular diseases and monitoring advanced therapies.

Choroid plexus, pineal gland, and habenula tend to accumulate physiologic calcifications (concrements) over a lifetime. However, until now the composition and causes of the intracranial calcifications remain unclear. The detailed analysis of concrements has been done by us using X-ray diffraction analysis (XRD), X-ray diffraction topography (XRDT), micro-CT, X-ray phase-contrast tomography (XPCT), as well as histology and immunohistochemistry (IHC). By combining physical (XRD) and biochemical (IHC) methods, we identified inorganic (hydroxyapatite) and organic (vimentin) components of the concrements. Via XPCT, XRDT, histological, and IHC methods, we assessed the structure of concrements within their appropriate tissue environment in both two and three dimensions. The study found that hydroxyapatite was a major component of all calcified depositions. It should be noted, however, that the concrements displayed distinctive characteristics corresponding to each specific structure of the brain. As a result, our study provides a basis for assessing the pathological and physiological changes that occur in brain structure containing calcifications.

The aim of this study was the detection and quantification of the Na + depositions in the extracellular matrix of myocardial tissue, which are suggested to be bound by negatively charged glycosaminoglycan (GAG) structures. The presented experimental results are based on high resolution X-ray fluorescence (XRF) spectromicroscopy technique used to perform a comparative analysis of sodium containment in intracellular and interstitial spaces of cardiac tissues taken from animals selected by low and high sodium intake rates. The experimental results obtained show that high sodium daily intake can result in a remarkable increase of sodium content in the myocardial interstitium.

A collection of more than 1800 carbonized papyri, discovered in the Roman ‘Villa dei Papiri’ at Herculaneum is the unique classical library survived from antiquity. These papyri were charred during 79 A.D. Vesuvius eruption, a circumstance which providentially preserved them until now. This magnificent collection contains an impressive amount of treatises by Greek philosophers and, especially, Philodemus of Gadara, an Epicurean thinker of 1st century BC. We read many portions of text hidden inside carbonized Herculaneum papyri using enhanced X-ray phase-contrast tomography non-destructive technique and a new set of numerical algorithms for ‘virtual-unrolling’. Our success lies in revealing the largest portion of Greek text ever detected so far inside unopened scrolls, with unprecedented spatial resolution and contrast, all without damaging these precious historical manuscripts. Parts of text have been decoded and the ‘voice’ of the Epicurean philosopher Philodemus is brought back again after 2000 years from Herculaneum papyri.

X-ray ptychography is a scanning coherent diffraction imaging technique which combines nanometer-scale resolution with high penetration depth. This method has been proven to be suitable for scanning weakly absorbing samples and therefore potentially very valuable for medical applications such as brain imaging. However, currently employed scanning techniques present challenges: step-scanning is too slow and inefficient, while fly-scanning introduces blurring and noise into reconstructions due to the motion and reduced photon counts per pixel. To date, only a few methods have been proposed to denoise reconstructions, most of which rely on traditional approaches and are limited in addressing the challenges posed by noise and blurring. To overcome these limitations, we investigate the possibility of using a deep learning-based denoising method combined with position binning. The deep learning-based denoising method, Deep Image Prior (DIP), denoises the reconstructions while position binning increases the photon count statistics per pixel. The method can be integrated within the existing iterative phase retrieval algorithms to denoise the object or probe in between iterations. The method is tested in far-field geometry on two different samples: a Siemens star resolution target and a polymer-based phantom mimicking the white matter of the brain. By assessing the resolution via Fourier ring correlation, we measure up to a 14% increase in the resolution. However, depending on the architecture used, artifacts due to machine hallucination appear in the denoised images which could be affecting the observed enhancement in resolution. This will be the subject of further investigation.

The investigation of the neuronal network in mouse spinal cord models represents the basis for the research on neurodegenerative diseases. In this framework, the quantitative analysis of the single elements in different districts is a crucial task. However, conventional 3D imaging techniques do not have enough spatial resolution and contrast to allow for a quantitative investigation of the neuronal network. Exploiting the high coherence and the high flux of synchrotron sources, X-ray Phase-Contrast multiscale-Tomography allows for the 3D investigation of the neuronal microanatomy without any aggressive sample preparation or sectioning. We investigated healthy-mouse neuronal architecture by imaging the 3D distribution of the neuronal-network with a spatial resolution of 640 nm. The high quality of the obtained images enables a quantitative study of the neuronal structure on a subject-by-subject basis. We developed and applied a spatial statistical analysis on the motor neurons to obtain quantitative information on their 3D arrangement in the healthy-mice spinal cord. Then, we compared the obtained results with a mouse model of multiple sclerosis. Our approach paves the way to the creation of a “database” for the characterization of the neuronal network main features for a comparative investigation of neurodegenerative diseases and therapies.

The paper reconstructs the history of what Sraffa called the ‘degeneration of cost’, as emerges from his manuscripts of the late 1920s. In particular, Sraffa regards the Physiocrats as having the correct idea of cost as being the commodities that allow workers to subsist. The classical economists measured this bundle of commodities in terms of labour, which they also ambiguously viewed as ‘toil and trouble’. Then, the idea of labour as ‘toil and trouble’ was indicated by Marshall as an anticipation of the conception of cost as a sacrifice. Conferring also upon abstinence from consumption the nature of sacrifice, the neoclassical-marginalist theory understood wages and interest as compensation for the disutility of working and saving. Then, cost was ultimately seen as what induces workers and capitalists to produce. This completed the degeneration of cost from the objective-physical conception of the Physiocrats to the subjective-psychological view of the marginalist school.

According to a new formulation, the average period of production is calculated by taking the shares of costs referable to each period out of the total amount of costs as weights. Once this notion had been introduced, its inverse relationship with the rate of interest prompted some scholars to believe that it could serve as a good measure of capital intensity, expecially in view of a possible resumption of the Austrian business-cycle theory. As will be shown, however, this new average period poses some problems. On the one hand, the inverse relationship mentioned above does not preclude the re-switching of production methods. On the other, if re-switching occurs, the most roundabout method may paradoxically be the one that gives the smallest net output per worker. This result can affect the revival of the Austrian business-cycle theory.

In these few pages I discuss some points concerning Lewin and Cachanosky’s Review of Austrian Economics, (2019) comment on my note (Fratini Review of Austrian Economics, 2019) about the implication of re-switching for the working of the Austrian business-cycle theory.