Sustainable and efficient refrigerants are essential due to increasing regulatory constraints on traditional high-GWP refrigerants. This study investigates the potential of natural refrigerants, ...specifically air, in Reverse Brayton Cycles (RBC) for low-temperature applications. Unlike carbon dioxide and ammonia, which pose limitations and safety concerns below -40°C, air offers a safer and more versatile solution due to its excellent thermodynamic properties and availability. An experimental RBC was constructed using automotive components like centrifugal compressors, a radial turbine, and inter-coolers. These cost-effective and accessible components shift the refrigeration paradigm. The RBC was tested to optimize the Coefficient of Performance (COP) at -100°C while dissipating 2 kW, a typical scenario for whole-body cryotherapy (WBC). Key control parameters included the pressure ratio of the centrifugal compressors and the position of the stator vanes in the variable geometry turbine (VGT). The optimization process resulted in a COP increase of up to 28%. Additionally, a 1D gas-dynamic model validated these results, suggesting that different component selections could enhance performance by 17% compared to the experimental optimum point. Air-based RBC systems using automotive components can effectively achieve temperatures below -40°C, offering a viable, eco-friendly alternative to traditional refrigerants. This advancement addresses regulatory challenges and contributes to the scientific community by providing a sustainable refrigeration solution using commercially available components and demonstrating improvements through experimental data.
•Lack of consensus on the use of natural refrigerants for temperatures below −40 °C.•Air-based RBC ensures null ODP, GWP, and A1 ASHRAE classification.•Building an RBC with automotive components is a cost-effective worldwide solution.•The RBC is tested by dissipating 2kW at −100 °C inside a climatic chamber.•An experimental campaign is designed and tested to optimize the COP.
Ewing's sarcoma (ES) is characterized by specific chromosome translocations, the most common being t(11;22)(q24;q12). Additionally, other type of genetic abnormalities may occur and be relevant for ...explaining the variable tumour biology and clinical outcome. We have carried out a high-resolution array CGH and expression profiling on 25 ES tumour samples to characterize the DNA copy number aberrations (CNA) occurring in these tumours and determine their association with gene-expression profiles and clinical outcome. CNA were observed in 84% of the cases. We observed a median number of three aberrations per case. Besides numerical chromosome changes, smaller aberrations were found and defined at chromosomes 5p, 7q and 9p. All CNA were compiled to define the smallest overlapping regions of imbalance (SORI). A total of 35 SORI were delimited. Bioinformatics analyses were conducted to identify subgroups according to the pattern of genomic instability. Unsupervised and supervised clustering analysis (using SORI as variables) segregated the tumours in two distinct groups: one genomically stable (< or =3 CNA) and other genomically unstable (>3 CNA). The genomic unstable group showed a statistically significant shorter overall survival and was more refractory to chemotherapy. Expression profile analysis revealed significant differences between both groups. Genes related with chromosome segregation, DNA repair pathways and cell-cycle control were upregulated in the genomically unstable group. This report elucidates, for the first time, data about genomic instability in ES, based on CNA and expression profiling, and shows that a genomically unstable group of Ewing's tumours is correlated with a significant poor prognosis.
ABSTRACT OJ 287 is a quasi-periodic quasar with roughly 12 year optical cycles. It displays prominent outbursts that are predictable in a binary black hole model. The model predicted a major optical ...outburst in 2015 December. We found that the outburst did occur within the expected time range, peaking on 2015 December 5 at magnitude 12.9 in the optical R-band. Based on Swift/XRT satellite measurements and optical polarization data, we find that it included a major thermal component. Its timing provides an accurate estimate for the spin of the primary black hole, . The present outburst also confirms the established general relativistic properties of the system such as the loss of orbital energy to gravitational radiation at the 2% accuracy level, and it opens up the possibility of testing the black hole no-hair theorem with 10% accuracy during the present decade.
We consider density solutions for gradient flow equations of the form
= ∇ · (
)∇ N(
)), where N is the Newtonian repulsive potential in the whole space ℝ
with the nonlinear convex mobility
) =
, and
...> 1. We show that solutions corresponding to compactly supported initial data remain compactly supported for all times leading to moving free boundaries as in the linear mobility case
) =
. For linear mobility it was shown that there is a special solution in the form of a disk vortex of constant intensity in space
=
supported in a ball that spreads in time like
, thus showing a discontinuous leading front or shock. Our present results are in sharp contrast with the case of concave mobilities of the form
) =
, with 0 <
< 1 studied in
. There, we developed a well-posedness theory of viscosity solutions that are positive everywhere and moreover display a fat tail at infinity. Here, we also develop a well-posedness theory of viscosity solutions that in the radial case leads to a very detailed analysis allowing us to show a waiting time phenomena. This is a typical behaviour for nonlinear degenerate diffusion equations such as the porous medium equation. We will also construct explicit self-similar solutions exhibiting similar vortex-like behaviour characterizing the long time asymptotics of general radial solutions under certain assumptions. Convergent numerical schemes based on the viscosity solution theory are proposed analysing their rate of convergence. We complement our analytical results with numerical simulations illustrating the proven results and showcasing some open problems.
A combination of molecular modeling and structure–activity relationship studies has been used to fine-tune CB2 selectivity in the chromenopyrazole ring, a versatile CB1/CB2 cannabinoid scaffold. ...Thus, a series of 36 new derivatives covering a wide range of structural diversity has been synthesized, and docking studies have been performed for some of them. Biological evaluation of the new compounds includes, among others, cannabinoid binding assays, functional studies, and surface plasmon resonance measurements. The most promising compound 43 (PM226), a selective and potent CB2 agonist isoxazole derivative, was tested in the acute phase of Theiler’s murine encephalomyelitis virus-induced demyelinating disease (TMEV-IDD), a well-established animal model of primary progressive multiple sclerosis. Compound 43 dampened neuroinflammation by reducing microglial activation in the TMEV.
B cell-activating factor (BAFF) is an essential cytokine in primary Sjögren’s syndrome (pSS) physiopathology. It has been reported that pSS patients develop germinal center-like (GC-like) structures ...in their minor salivary glands (MSGs). BAFF, BAFF-R, TACI, and BCMA expression was analyzed in MSGs from 29 subjects (nonspecific chronic sialadenitis and focal lymphocytic sialadenitis with the presence pSS-GC(+) or absence pSS-GC(−) of GC-like structures). Twenty-four percent of patients showed ectopic GC-like structures and a high focus score
p
< 0.001
vs
pSS-GC(−). BAFF serum levels (sBAFF) were high in pSS patients (
p
= 0.025
vs
healthy subjects). However, the pSS-GC(−) group showed higher sBAFF levels than pSS-GC(+) patients. BAFF and BAFF-R glandular expression levels were higher in pSS-GC(+) patients, without significant differences compared to pSS-GC(−) patients. Soluble levels of BAFF correlated with anti-La/SSB antibodies and disease duration. Our results showed that BAFF could contribute to focal lymphocytic infiltration. The role of BAFF-binding receptors in MSGs is proposed as a mechanism for the possible establishment of ectopic GC-like structures and disease progression in some patients. In conclusion, this study supports previous evidence that considers the active BAFF system role in the pathogenesis of pSS and the need for strong biomarkers in this disease.
After the meeting held by the Spanish Contact Dermatitis and Skin Allergy Research Group (GEIDAC) back in October 2021, changes were suggested to the Spanish Standard Series patch testing. ...Hydroxyethyl methacrylate (2% pet.), textile dye mixt (6.6% pet.), linalool hydroperoxide (1% pet.), and limonene hydroperoxide (0.3% pet.) were, then, added to the series that agreed upon in 2016. Ethyldiamine and phenoxyethanol were excluded. Methyldibromoglutaronitrile, the mixture of sesquiterpene lactones, and hydroxyisohexyl 3-cyclohexene (Lyral) were also added to the extended Spanish series of 2022.
En la reunión de consenso celebrada por el Grupo Español de Investigación en Dermatitis de Contacto y Alergia Cutánea en octubre del 2021 se estableció la composición actualizada de la batería estándar española de pruebas epicutáneas. A la batería consensuada en 2016 se añaden hidroxi-etil-metacrilato (2% vas.), mezcla colorante textil (6,6% vas.), hidroperóxido de linalool (1% vas.) e hidroperóxido de limoneno (0,3% vas.). Se excluyen la etieldiamina y el fenoxietanol. El metildibromoglutaronitrilo, la mezcla de lactonas sesquiterpénicas y el hidroxi-isohexil 3-ciclohexeno (Lyral) pasan a la batería española ampliada 2022.
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![[Translated article] Standa...](http://api.summon.serialssolutions.com/2.0.0/image/issn/XR4PS5YY4K/0001-7310/small "[Translated article] Standard and Expanded Series Patch Testing Update by the Spanish Contact Dermatitis and Skin Allergy Research Group (GEIDAC)")