With Bains publics, Sophie Richelle offers an original double story. That of the history of communal baths, understood as the places where it was possible to have a wash outside home at a lower cost ...in the nineteenth and twentieth centuries. And that of the historian's quest being conducted.
Avec Bains publics, Sophie Richelle propose un double récit original. Celui de l'histoire des bains communaux, compris comme les endroits où il était possible de se laver en dehors de chez soi à moindre coût aux XIX e et XX e siècles. Et celui de la quête historienne en train d’être menée
Extrusion-based 3D printers have been adopted in pursuit of engineering functional tissues through 3D bioprinting. However, we are still a long way from the promise of fabricating constructs ...approaching the complexity and function of native tissues. A major challenge is presented by the competing requirements of biomimicry and manufacturability. This opinion article discusses 3D printing in suspension baths as a novel strategy capable of disrupting the current bioprinting landscape. Suspension baths provide a semisolid medium to print into, voiding many of the inherent flaws of printing onto a flat surface in air. We review the state-of-the-art of this approach and extrapolate toward future possibilities that this technology might bring, including the fabrication of vascularized tissue constructs.
3D printing in suspension media unlocks the full potential of extrusion-based 3D printers by providing a strategy for fabricating non–self-supporting structures from water-rich, low-viscosity bioinks.Biomimetic structures representative of native vascular channels have been printed in suspension media, demonstrating that both omnidirectional printing and printing in discrete arbitrary locations are possible with this printing strategy.Retention of a suspension medium following printing of embedded constructs is achievable through crosslinking. Suspension media are therefore able to double as a 3D cell culture substrate in which printed features such as vessels or cell populations can help with maturing of the engineered tissue.
According to the second law, the efficiency of cyclic heat engines is limited by the Carnot bound that is attained by engines that operate between two thermal baths under the reversibility condition ...whereby the total entropy does not increase. Quantum engines operating between a thermal and a squeezed-thermal bath have been shown to surpass this bound. Yet, their maximum efficiency cannot be determined by the reversibility condition, which may yield an unachievable efficiency bound above unity. Here we identify the fraction of the exchanged energy between a quantum system and a bath that necessarily causes an entropy change and derive an inequality for this change. This inequality reveals an efficiency bound for quantum engines energised by a non-thermal bath. This bound does not imply reversibility, unless the two baths are thermal. It cannot be solely deduced from the laws of thermodynamics.
Atopic dermatitis is a chronic inflammatory skin disease. The treatment plays an important role in influencing the patients' quality of life. The basic management consists of appropriate skin ...cleansing, including bathing and eventually using bathing additives. Recommendations regarding frequency and duration of bathing, water temperature and usefulness of bathing additives are widely different, often leading to confusion among patients. This review aims to give insights into the best bathing practices and the use of bathing additives in atopic dermatitis in children. Several bathing additives, including bleach baths, commercial baby cleansers, bath baby oils and bath salt, appear to be promising adjunctive therapies for atopic dermatitis due to their anti-inflammatory, anti-bacterial, anti-pruritus and skin barrier repair properties through different mechanisms of action. However, their efficacy and safety are not fully understood in some cases. The usefulness of other bath additives, such as acidic and more natural substances (green tea extracts, pine tar, sodium bicarbonate), is still under investigation. Further studies are needed to determine their optimal use to achieve clinical benefit safely.
Abstract
A quantum thermal machine is an open quantum system coupled to hot and cold thermal baths. Thus, its dynamics can be well understood using the concepts and tools from non-Hermitian quantum ...systems. A hallmark of non-Hermiticity is the existence of exceptional points where the eigenvalues of a non-Hermitian Hamiltonian or a Liouvillian superoperator and their associated eigenvectors coalesce. Here, we report the experimental realization of a single-ion heat engine and demonstrate the effect of Liouvillian exceptional points on the dynamics and the performance of a quantum heat engine. Our experiments have revealed that operating the engine in the exact- and broken-phases, separated by a Liouvillian exceptional point, respectively during the isochoric heating and cooling strokes of an Otto cycle produces more work and output power and achieves higher efficiency than executing the Otto cycle completely in the exact phase where the system has an oscillatory dynamics and higher coherence. This result opens interesting possibilities for the control of quantum heat engines and will be of interest to other research areas that are concerned with the role of coherence and exceptional points in quantum processes and in work extraction by thermal machines.
Abstract
Colloidal heat engines are paradigmatic models to understand the conversion of heat into work in a noisy environment - a domain where biological and synthetic nano/micro machines function. ...While the operation of these engines across thermal baths is well-understood, how they function across baths with noise statistics that is non-Gaussian and also lacks memory, the simplest departure from the thermal case, remains unclear. Here we quantified the performance of a colloidal Stirling engine operating between an engineered memoryless non-Gaussian bath and a Gaussian one. In the quasistatic limit, the non-Gaussian engine functioned like a thermal one as predicted by theory. On increasing the operating speed, due to the nature of noise statistics, the onset of irreversibility for the non-Gaussian engine preceded its thermal counterpart and thus shifted the operating speed at which power is maximum. The performance of nano/micro machines can be tuned by altering only the nature of reservoir noise statistics.
We explore the spacetime structure near nonextremal horizons in any spacetime dimension greater than two and discover a wealth of novel results: (i) Different boundary conditions are specified by a ...functional of the dynamical variables, describing inequivalent interactions at the horizon with a thermal bath. (ii) The near horizon algebra of a set of boundary conditions, labeled by a parameter s, is given by the semidirect sum of diffeomorphisms at the horizon with "spin-s supertranslations." For s=1 we obtain the first explicit near horizon realization of the Bondi-Metzner-Sachs algebra. (iii) For another choice, we find a nonlinear extension of the Heisenberg algebra, generalizing recent results in three spacetime dimensions. This algebra allows us to recover the aforementioned (linear) ones as composites. (iv) These examples allow us to equip not only black holes, but also cosmological horizons with soft hair. We also discuss implications of soft hair for black hole thermodynamics and entropy.
Atopic dermatitis (AD) is a common skin disorder, especially in the pediatric population. Genetic and immunological factors, epidermal barrier defect, as well as skin microbiota imbalance with ...increased colonization by Staphylococcus aureus (SA) are involved in the pathogenesis of the disease. One of the AD topical treatments is sodium hypochlorite (NaOCl) as a 0.005% water bath solution. This substance has been used for years as an antiseptic preparation. Studies show that NaOCl has an antimicrobial effect but probably at higher concentrations than those used in AD treatment. Nevertheless, many research studies confirm the anti‐inflammatory and anti‐itching effects of NaOCl, which contributes to clinical improvement in AD patients as well as reducing the need for local steroids and antibiotics. Bleach baths seem to be a well tolerated, cheap, and easily available therapy. However, research still should be continued to evaluate its antibacterial efficacy, anti‐inflammatory effects, and safety.
Background Patients with atopic dermatitis (AD) are prone to skin infections, with microbes such as Staphylococcus aureus suspected of contributing to pathogenesis. Bleach baths might improve AD by ...reducing skin microbial burden. Objective We sought to characterize the microbiota of lesional and nonlesional skin in young children with AD and control subjects and compare changes after treatment with a topical corticosteroid (TCS) alone or TCS + dilute bleach bath. Methods In a randomized, placebo-controlled, single-blinded clinical trial in 21 children with AD and 14 healthy children, lesional and nonlesional AD skin was examined at baseline and after 4-week treatment with TCS alone or TCS plus bleach bath. Microbial DNA was extracted for quantitative polymerase chain reaction of predominant genera and 16S rRNA sequencing. Results At baseline, densities of total bacteria and Staphylococcus , including Staphylococcus aureus , were significantly higher at the worst AD lesional site than nonlesional ( P = .001) or control ( P < .001) skin; bacterial communities on lesional and nonlesional AD skin significantly differed from each other ( P = .04) and from control ( P < .001). After TCS + bleach bath or TCS alone, bacterial compositions on lesional skin normalized ( P < .0001), resembling nonlesional skin, with microbial diversity restored to control skin levels. Limitations The 4-week time period and/or the twice-weekly baths may not have been sufficient for additional impact on the cutaneous microbiome. More detailed sequencing may allow better characterization of the distinguishing taxa with bleach bath treatment. Conclusions Treatment with a TCS cream suffices to normalize the cutaneous microbiota on lesional AD; after treatment, bacterial communities on lesional skin resemble nonlesional skin but remain distinct from control.
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