Numeric study of geothermal borehole heat exchanger enhancement via phase change material macro encapsulation

Funding text 1 This work was financially supported by the TESSe2b project that has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 680555 . This article reflects only the authors’ view and the European Commission is not responsible for any use that may be made of the information it contains. This publication was supported by the Polytechnic Institute of Setúbal, Portugal . Funding text 2 This work was financially supported by the TESSe2b project that has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 680555. This article reflects only the authors’ view and the European Commission is not responsible for any use that may be made of the information it contains. This publication was supported by the Polytechnic Institute of Setúbal, Portugal.This article addresses the theoretical effect of using geothermal boreholes enhanced with macro-encapsulated phase change materials (PCM) employed with a ground sourced heat pump (GSHP). The aim being the improvement of the heat pump performance through soil temperature stabilisation, taking advantage from the PCM inherent property of changing phase at a constant temperature, that can be matched with the temperature of the surrounding soil, contributing as well to increase the energy storage capacity underground. The numeric work studied different PCM thermal parameters with regards to their influence on the overall behaviour of the heat pump, with different operation modes (On/Off and Inverter) changing the solidus and liquidus temperatures and phase change enthalpy values. The CFD results showed that, while it underperformed having 0.15% difference in the best of cases (specifically the On/Off mode), it used in the best case scenario only 30% of the stored energy in the PCM. The application of macro-encapsulation did provide a stabilising effect to the soil and heap pump operation as it was originally intended to do, helping reduce energy expenditure by the system. Significant modifications are needed in order to improve, both concerning geometry and encapsulation techniques to overcome the PCM and other materials thermal limitations.publishersversionpublishe

Monoclinic polymorph of 2-(pyrimidin-2-ylsulfan­yl)acetic acid

The title compound, C6H6N2O2S, is a new polymorphic form of 2-(pyrimidin-2-ylsulfan­yl)acetic acid. Unlike the previous orthorhombic polymorph [Pan & Chen (2009 ▶) Acta Cryst. E65, o652], the mol­ecules are not planar: the aromatic ring makes an angle of 80.67 (17)° with the carboxyl plane. In the crystal, mol­ecules are linked by O—H⋯N hydrogen bonds into chains along [02]

Ethyl 7-Acetyl-8a-methyl-3-(1-phenyl-1H-tetrazol-5-yl)-1,4,4a,5,6,8a-hexahydro-7H-pyrano[2,3-c]pyridazine-1-carboxylate

The Diels–Alder reaction of ethyl 3-(1-phenyl-1H-tetrazol-5-yl-1,2-diaza-1,3-butadiene-1-carboxylate with 2-acetyl-6-methyl-2,3-dihydro-4H-pyran (methyl vinyl ketone dimer) regioselectively afforded the corresponding 3-(tetrazol-5-yl)-hexahydro-7H-pyrano[2,3-c]pyridazine in quantitative yield. An X-ray crystal structure of this cycloadduct is reported.info:eu-repo/semantics/publishedVersio

As mulheres e a SIDA

Podem existir diferenças entre os sexos no que se refere aos factores biológicos, psicológicos e sociais associados & infecção pelo VIH (Vírus da Imunodeficiência Humana). Os autores fazem uma revisão da epidemiologia da SIDA nas Mulheres, evolução da infecção pelo VIH, factores mais especificamente associados ao VIH/SIDA nas Mulheres, gravidez e SIDA e, finalmente, aconselhamento de Mulheres.ABSTRACT------Male-female differences may exist in the biological, psychological and psychosocial determinants and consequences of HIV-infection and AIDS. The authors review epidemiology of women with AIDS, and aspects related to clinical course for women with AIDS, biological and psychological factors associated to women with HIV-infection, HIV and AIDS in pregnancy, and women counsellin

On the development of selective chelators for Cadmium: Synthesis, structure and chelating properties of 3-((5-(trifluoromethyl)-1,3,4-thiadiazol-2-yl)amino)benzo[d]isothiazole 1,1-dioxide, a novel Thiadiazolyl Saccharinate

Aquatic contamination by heavy metals is a major concern for the serious negative consequences it has for plants, animals, and humans. Among the most toxic metals, Cd(II) stands out since selective and truly efficient methodologies for its removal are not known. We report a novel multidentate chelating agent comprising the heterocycles thiadiazole and benzisothiazole. 3-((5-(trifluoromethyl)-1,3,4-thiadiazol-2-yl)amino)benzo[d]isothiazole 1,1-dioxide (AL14) was synthesized from cheap saccharin and characterized by different techniques, including single crystal X-ray crystallography. Our studies revealed the efficiency and selectivity of AL14 for the chelation of dissolved Cd(II) (as compared to Cu(II) and Fe(II)). Different spectral changes were observed upon the addition of Cd(II) and Cu(II) during UV-Vis titrations, suggesting different complexation interactions with both metals.UIDB/04326/2020, UIDB/04564/2020, ALG-01-0145-FEDER-022121, SFRH/BD/130407/2017info:eu-repo/semantics/publishedVersio

Synthesis, structure and antileishmanial evaluation of endoperoxide–pyrazole hybrids

Leishmaniases are among the most impacting neglected tropical diseases. In attempts to repurpose antimalarial drugs or candidates, it was found that selected 1,2,4-trioxanes, 1,2,4,5-tetraoxanes, and pyrazole-containing chemotypes demonstrated activity against Leishmania parasites. This study reports the synthesis and structure of trioxolane–pyrazole (OZ1, OZ2) and tetraoxane–pyrazole (T1, T2) hybrids obtained from the reaction of 3(5)-aminopyrazole with endoperoxide-containing building blocks. Interestingly, only the endocyclic amine of 3(5)-aminopyrazole was found to act as nucleophile for amide coupling. However, the fate of the reaction was influenced by prototropic tautomerism of the pyrazole heterocycle, yielding 3- and 5-aminopyrazole containing hybrids which were characterized by different techniques, including X-ray crystallography. The compounds were evaluated for in vitro antileishmanial activity against promastigotes of L. tropica and L. infantum, and for cytotoxicity against THP-1 cells. Selected compounds were also evaluated against intramacrophage amastigote forms of L. infantum. Trioxolane–pyrazole hybrids OZ1 and OZ2 exhibited some activity against Leishmania promastigotes, while tetraoxane–pyrazole hybrids proved inactive, most likely due to solubility issues. Eight salt forms, specifically tosylate, mesylate, and hydrochloride salts, were then prepared to improve the solubility of the corresponding peroxide hybrids and were uniformly tested. Biological evaluations in promastigotes showed that the compound OZ1•HCl was the most active against both strains of Leishmania. Such finding was corroborated by the results obtained in assessments of the L. infantum amastigote susceptibility. It is noteworthy that the salt forms of the endoperoxide–pyrazole hybrids displayed a broader spectrum of action, showing activity in both strains of Leishmania. Our preliminary biological findings encourage further optimization of peroxide–pyrazole hybrids to identify a promising antileishmanial lead.info:eu-repo/semantics/publishedVersio

Esterase production by Aureobasidium pullulans URM 7059 in stirred tank and airlift bioreactors using residual biodiesel glycerol as substrate

Supplementary material related to this article can be found, in the online version, at doi:https://doi.org/10.1016/j.bej.2021.107954.Aureobasidium pullulans URM 7059 produced esterase using residual glycerol from biodiesel as the sole carbon source. The culture medium containing residual glycerol (0.1% v/v), (NH4)2SO4 (4g/L), and yeast extract (8g/L) resulted in the highest esterase production using shake-flasks. The enzyme exhibited a molar mass of 50kDa and was stable at neutral pH and temperatures below 30°C. The cations Cu2+ and Al3+ did not affect the esterase activity, while Ca2+ promoted the highest activity loss. The enzyme kinetic parameters were determined using different substrates (p-nitrophenylcaprylate and p-nitrophenylbutyrate). Km and Vmax were 1.4mM and 218µmolmin-1 for p-NPC, and 1.55mM and 76.7µmolmin-1 for p-NPB. The esterase production was further evaluated using stirred tank and 2-L airlift bioreactors. The airlift reactor operating at the highest air flow rate (8L/min) increased the enzyme productivity 3-fold compared to the shake-flasks experiments. However, the crude enzymatic extract showed 3 active protein bands by zymography with molecular masses of 172kDa, 66kDa, and 40kDa approximately, suggesting that the pattern of enzyme production changed due to aeration. The crude enzyme degraded the MACO-Sty biopolymer in 14 days, being stable in a wide range of pH (7.0 9.0) and temperatures (40°C 80°C). The results suggest that this enzyme is a promising catalyst in remediation processes.This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2020 unit and BioTecNorte operation (NORTE-01-0145-FEDER-000004), projects MultiBiorefinery (POCI-01-0145-FEDER016403) and Lignozymes (POCI-01-0145-FEDER-029773), all funded by the European Regional Development Fund under the scope of Norte2020 – Programa Operacional Regional do Norte. In Brazil, this study was financed in part by the Coordenaçao ˜ de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES) - Finance Code 001. The authors also thank the CNPq and FUNCAP for financial support.info:eu-repo/semantics/publishedVersio

Molecular and crystal structure, spectroscopy, and photochemistry of a dispiro compound bearing the tetraoxane pharmacophore

The molecular structure and photochemistry of dispiro[cyclohexane-1,3′-[1,2,4,5]tetraoxane-6′,2′′-tricyclo[3.3.1.13,7]decan]-4-one (TX), an antiparasitic 1,2,4,5-tetraoxane was investigated using matrix isolation IR and EPR spectroscopies, together with quantum chemical calculations undertaken at the DFT(B3LYP)/6-311++G(3df,3pd) level of theory, with and without Grimme's dispersion correction. Photolysis of the matrix-isolated TX, induced by in situ broadband (λ>235 nm) or narrowband (λ in the range 220–263 nm) irradiation, led to new bands in the infrared spectrum that could be ascribed to two distinct photoproducts, oxepane-2,5-dione, and 4-oxohomoadamantan-5-one. Our studies show that these photoproducts result from initial photoinduced cleavage of an O−O bond, with the formation of an oxygen-centered diradical that regioselectivity rearranges to a more stable (secondary carbon-centered)/(oxygen-centered) diradical, yielding the final products. Formation of the diradical species was confirmed by EPR measurements, upon photolysis of the compound at λ=266 nm, in acetonitrile ice (T=10–80 K). Single-crystal X-ray diffraction (XRD) studies demonstrated that the TX molecule adopts nearly the same conformation in the crystal and matrix-isolation conditions, revealing that the intermolecular interactions in the TX crystal are weak. This result is in keeping with observed similarities between the infrared spectrum of the crystalline material and that of matrix-isolated TX. The detailed structural, vibrational, and photochemical data reported here appear relevant to the practical uses of TX in medicinal chemistry, considering its efficient and broad parasiticidal properties.JP17H03022; 20K21197; 21H01921; 22K19033; JPMJCR18R4; JPMJCR18R4info:eu-repo/semantics/publishedVersio