The Gamow-state description of the decay energy spectrum of neutron-unbound 25O

We show the feasibility of calculating the decay energy spectrum of neutron emitting nuclei within the Gamow-state description of resonances by obtaining the decay energy spectrum of 25O. We model this nucleus as a valence neutron interacting with an 24O inert core, and we obtain the resulting resonant energies, widths and decay energy spectra for the ground and first excited states. We also discuss the similarities and differences between the decay energy spectrum of a Gamow state and the Breit–Wigner distribution with energy-dependent width.Fil: Id Betan, Rodolfo Mohamed. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Física de Rosario. Universidad Nacional de Rosario. Instituto de Física de Rosario; ArgentinaFil: de la Madrid, Rafael. Lamar University; Estados Unido

Variable threshold of trigeminal cold-thermosensitive neurons is determined by a balance between TRPM8 and Kv1 potassium channels

Molecular determinants of threshold differences among cold thermoreceptors are unknown. Here we show that such differences correlate with the relative expression of IKD, a current dependent on Shaker-like Kv1 channels that acts as an excitability brake, and ITRPM8, a cold-activated excitatory current. Neurons responding to small temperature changes have high functional expression of TRPM8 (transient receptor potential cation channel, subfamily M, member 8) and low expression of IKD. In contrast, neurons activated by lower temperatures have a lower expression of TRPM8 and a prominent IKD. Otherwise, both subpopulations have nearly identical membrane and firing properties, suggesting that they belong to the same neuronal pool. Blockade of IKD shins the threshold of cold-sensitive neurons to higher temperatures and augments cold-evoked nocifensive responses in mice. Similar behavioral effects of IKD blockade were observed in TRPA1-/- mice. Moreover, only a small percentage of trigeminal cold-sensitive neurons were activated by TRPA1 agonists, suggesting that TRPA1 does not play a major role in the detection of low temperatures by uninjured somatic cold-specific thermosensory neurons under physiological conditions. Collectively, these findings suggest that innocuous cooling sensations and cold discomfort are signaled by specific low- and high-threshold cold thermoreceptor neurons, differing primarily in their relative expression of two ion channels having antagonistic effects on neuronal excitability. Thus, although TRPM8 appears to function as a critical cold sensor in the majority of peripheral sensory neurons, the expression of Kv1 channels in the same terminals seem to play an important role in the peripheral gating of cold-evoked discomfort and pain. Copyright © 2009 Society for Neuroscience.This work was supported by funds from the Spanish Ministry of Education and Science: Projects BFU2007-61855 to F.V., and BFU2005-08741 and CONSOLIDER-INGENIO 2010 CSD2007-00023 to C.B., and the Spanish Fundación Marcelino BotínPeer Reviewe

Biofortificação de selênio no crescimento de alho e avaliação de acúmulo de outros elementos nutrientes

Selenium (Se) is an essential element for humans and has anti-cancer function. Garlic can accumulate Se, so it is an option to Se supplementation in the human diet. The aim of this research was to study Se uptake and accumulation during garlic growth. Four doses of Na2 SeO4 and Na2 SeO3 solution were applied in the substrate (0, 5, 10 and 15 kg ha-1 Se) for one time in August 2014, with a random plot design and 3 replicates on garlic clone Rubi INTA. Three harvests were made, in September, October and December 2014. After each harvest, leaves, bulbs and roots were separated and conditioned (peeled and chopped), lyophilized, and finally acid-digested prior to Se, Mg, Zn, Mn, Cu, Fe, P and S determination by inductively coupled plasma mass spectrometry (ICP-MS). The Se accumulation was proportional to Se doses and did not affect garlic growth. Also, Se distribution among different organs was related to the garlic growth cycle. The Se presence decreased accumulation of Mg, Mn, Cu, Fe, P and S but increased Zn accumulation in plants. Garlic can be an important Se source to humans but it is important to consider Se-doses for biofortification.O selênio (Se) é elemento essencial para os seres humanos e é considerado anticancerígeno. Alho pode acumular Se, sendo, por isso, uma opção para a suplementação de Se na dieta humana. Assim, o objetivo deste trabalho foi estudar a captação e acúmulo de selênio durante o crescimento do alho e avaliar os efeitos da fortificação de Se. Quatro doses da solução de Se, nas formas de Na2 SeO4 e Na2 SeO3 foram aplicadas ao substrato em agosto de 2014 (0, 5, 10 e 15 kg ha-1 de Se) de uma única vez, em delineamento de parcela aleatória e 3 repetições no clone de alho Rubi INTA. Três colheitas foram feitas, em setembro, outubro e dezembro de 2014. Após cada colheita, as folhas, bulbos e raízes das amostras de alho resultantes de cada tratamento foram separadas e acondicionadas (descascadas e picadas), liofilizadas, e, finalmente, digeridas com ácido antes da determinação de Mg, Zn, Mn, Cu, Fe, P e S por espectrometria de massa com plasma indutivamente acoplado (ICP-MS). Os resultados confirmaram que o acúmulo de Se foi proporcional à magnitude das doses, e não afetou significativamente o crescimento do alho. Além disso, a distribuição de Se entre os diferentes compartimentos da planta foi relacionada ao ciclo de crescimento da planta de alho. A fortificação do alho com Se causou mudanças significativas, e induziu o acúmulo e distribuição de diferentes nutrientes, como Zn, Mg, Mn, Cu, Fe, P e S, mas aumentou o acúmulo de Zn nas plantas. O alho pode ser considerado fonte importante de Se para aumentar a ingestão deste elemento na dieta humana, mas é importante considerar as doses de Se para a biofortificação.Fil: Pérez, María Belén. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Interdisciplinario de Ciencias Básicas. - Universidad Nacional de Cuyo. Instituto Interdisciplinario de Ciencias Básicas; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Exactas y Naturales. Laboratorio de Química Analítica para Investigación y Desarrollo; ArgentinaFil: Lipinski, Víctor Mario. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Mendoza-San Juan. Estación Experimental Agropecuaria La Consulta; ArgentinaFil: Filippini, Maria Flavia Ramona. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Interdisciplinario de Ciencias Básicas. - Universidad Nacional de Cuyo. Instituto Interdisciplinario de Ciencias Básicas; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Exactas y Naturales. Laboratorio de Química Analítica para Investigación y Desarrollo; ArgentinaFil: Chacón Madrid, Katherine. Universidade Estadual Do Campinas. Instituto de Química.; BrasilFil: Arruda, Marco Aurelio Z.. Universidade Estadual Do Campinas. Instituto de Química.; BrasilFil: Wuilloud, Rodolfo German. Universidad Nacional de Cuyo. Facultad de Ciencias Exactas y Naturales. Laboratorio de Química Analítica para Investigación y Desarrollo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Interdisciplinario de Ciencias Básicas. - Universidad Nacional de Cuyo. Instituto Interdisciplinario de Ciencias Básicas; Argentin

Pro-oxidant status and matrix metalloproteinases in apical lesions and gingival crevicular fluid as potential biomarkers for asymptomatic apical periodontitis and endodontic treatment response

<p>Abstract</p> <p>Background</p> <p>Oxidative stress and matrix metalloproteinases -9 and -2 are involved in periodontal breakdown, whereas gingival crevicular fluid has been reported to reflect apical status. The aim of this study was to characterize oxidant balance and activity levels of MMP -2 and -9 in apical lesions and healthy periodontal ligament; and second, to determine whether potential changes in oxidant balance were reflected in gingival crevicular fluid from asymptomatic apical periodontitis (AAP)-affected teeth at baseline and after endodontic treatment.</p> <p>Methods</p> <p>Patients with clinical diagnosis of AAP and healthy volunteers having indication of tooth extraction were recruited. Apical lesions and healthy periodontal ligaments, respectively, were homogenized or processed to obtain histological tissue sections. Matrix metalloproteinase -9 and -2 levels and/or activity were analyzed by Immunowestern blot, zymography and consecutive densitometric analysis, and their tissue localization was confirmed by immunohistochemistry. A second group of patients with AAP and indication of endodontic treatment was recruited. Gingival crevicular fluid was extracted from AAP-affected teeth at baseline, after endodontic treatment and healthy contralateral teeth. Total oxidant and antioxidant status were determined in homogenized tissue and GCF samples. Statistical analysis was performed using STATA v10 software with unpaired t test, Mann-Whitney test and Spearman's correlation.</p> <p>Results</p> <p>Activity of MMP-2 and MMP-9 along with oxidant status were higher in apical lesions (p < 0.05). Total oxidant status correlated positively with matrix metalloproteinase-2 and lesion size (p < 0.05). Gingival crevicular fluid showed significantly lower levels of total antioxidant status in diseased teeth at baseline compared to controls and endodontically-treated groups.</p> <p>Conclusions</p> <p>Apical lesions display an oxidant imbalance along with increased activity of matrix metalloproteinase-2 and -9 and might contribute to AAP progression. Oxidant imbalance can also be reflected in GCF from AAP-affected teeth and was restored to normal levels after conservative endodontic treatment. These mediators might be useful as potential biomarkers for chair-side complementary diagnostic of apical status in GCF.</p

Contaminação do ar por Aspergillus em ambiente de reabilitação de animais marinhos

Espécies fúngicas do gênero Aspergillus são frequentemente associadas com alta mortalidade de aves marinhas em cativeiro. Tendo em vista que a aspergilose geralmente é adquirida pela inalação dos propágulos fúngicos presentes no ar, o estudo objetivou avaliar a qualidade do ar quanto às espécies de Aspergillus, das instalações internas de um centro de reabilitação de animais marinhos que frequentemente recebe pingüins, gaivotas, albatrozes e petréis acometidos por alguma moléstia. Oitenta e um dias de colheitas foram realizados distribuídos em um período de aproximadamente dois anos, através da exposição de placas de Petri contendo Agar Sabouraud dextrose acrescido de cloranfenicol no ambiente, as quais foram posteriormente incubadas a 25ºC. As colônias identificadas como pertencentes ao gênero Aspergillus, foram classificadas quanto à espécie através da avaliação macro e micro morfológica associada a uma chave de identificação. Foram obtidos 43 isolados classificados em sete espécies distintas, sendo A. fumigatus a predominante correspondendo a 27,9%, seguida de A. niger, A. flavus e outras quatro espécies de Aspergillus sp., demonstrando que as aves marinhas estão expostas a espécies fúngicas com potencial patogênico, o que enfatiza a necessidade de um controle microbiológico no ambiente onde são mantidos os animais em cativeiro.Aspergillosis in captivity seabirds is often associated with elevated rates of mortality. The infection is usually acquired by inhalation of airborne fungal conidia. The aim of this study was to evaluate the presence of Aspergillus species in the indoor environment of a rehabilitation centre for marine animals in Southern Brazil. This centre continuously receives injured penguins, seagulls, albatrosses and petrels. Petri dishes plates with Agar Sabouraud dextrose and chloramphenicol were left open for 15 minutes in 3 distinct points in the rehabilitation centre and then incubated at 25ºC. During a period of two years the indoor air was sampled in 81 occasions. A total of 43 isolates belonging to 7 different Aspergillus species were recovered. Aspegillus fumigatus was the predominant species (27.9%), followed by A. niger (25.6%), and A. flavus (16.3%). Four other Aspergillus species were isolated. This study demonstrates that seabirds were exposed to pathogenic Aspergillus species in our rehabilitation centre, reinforcing the need for a strict microbiology control of the indoor air in the captivity environment

Constitutive phosphorylation of serine 29 as a critical regulator of TRPM8 channel function

Resumen del trabajo presentado al VIII Congreso Red Española de Canales Iónicos, celebrado en Alicante del 24 al 27 de mayo de 2022.The main molecular entity involved in innocuous cold detection in mammals is TRPM8. This polymodal TRP channel is activated by cold, cooling compounds such as menthol, voltage, and rises in osmolality. Basal kinase activity phosphorylates TRPM8 and modulates its function under resting conditions. However, which specific residues, how this post-translational modification modulates TRPM8 activity, and its influence on cold sensing are still poorly understood. We identified four serine residues within the N-terminal domain constitutively phosphorylated in the mouse ortholog by mass spectrometry. TRPM8 function was assessed by Ca2+-imaging and patch-clamp recordings, revealing that treatment with staurosporine, a kinase inhibitor, increased cold- and mentholevoked responses of the channel. S29A mutation is sufficient to enhance TRPM8 activity, suggesting that phosphorylation of this residue is a critical molecular determinant of this negative regulation. Biophysical and TIRF-based analysis revealed a dual mechanism in the potentiated responses of unphosphorylated TRPM8: an increase in the number of active channels at the plasma membrane and a shift in the voltage activation curve towards more negative potentials. Notably, basal kinase activity downregulates TRPM8 function at cold thermoreceptor neurons, an observation accounted for by mathematical modeling. Overall, our findings suggest that cold temperature detection could be rapidly and reversibly fine-tuned by controlling the TRPM8 basal phosphorylation state, a mechanism that acts as a dynamic molecular brake of this thermo-TRP channel function in primary sensory neurons.Supported by Grants Millennium Nucleus for the Study of Pain (MiNuSPain) (RM, MP), Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD) (RM, MP), DICYT VRIDeI-USACH 022143PP (MP, RM) and by VRIDeI-USACH 021843MM (RM).Peer reviewe

Cooling rate modifies the location of aquaporin 3 in spermatozoa of sheep and goat

30 Pág.The freeze-thawing process induces osmotic changes that may affect the membrane domain location of aquaporins’ (AQP) in spermatozoa. Recent studies suggest that changes in AQP3 localization allows better sperm osmo-adaptation, improving the cryoresistance. Ultra-rapid freezing is an alternative cryopreservation technique that requires less equipment than conventional freezing, and it is faster, simpler and can be used in the field. This study aimed to determine the influence of freezing-thawing rates (slow (control) vs. ultra-rapid) on AQP3 expression and location in the spermatozoa from small ruminants (sheep and goats) and its relationship with sperm cryo-damage. Spermatozoa were collected from 10 Merino rams and 10 Murciano-Granadina bucks. The presence and distribution of AQP3 were assessed by Western blotting and immunocytochemistry (ICC), employing a commercial rabbit polyclonal antibody. Sperm motility was CASA system-analyzed, and membrane and acrosome integrity assessed by fluorescence (PI/PNA-FITC). Western blotting did not detect a significant effect of freezing-thawing rate on the amount of AQP3 while ICC found freezing-thawing rate affecting AQP3 location (P<0.05). In both species, the percentages of spermatozoa showing AQP3 in the post-acrosome region, mid-piece, and principal piece of the tail were greater in samples cryopreserved by slow freezing-thawing (control) than ultra-rapid freezing-thawing rates (P<0.05). Spermatozoa cryopreserved using ultra-rapid freezing-thawing showed decrease motility, plasma membrane, and acrosome integrity (P<0.05), which might be related, at least in part, to a lower expression of AQP3. In conclusion, the cooling rate modifies the location of AQP3 in spermatozoa of sheep and goat, which might be associated with sperm cryosurvival.This study was supported by the project PID2020-113288RB-I00/AEI/10.13039/501100011033. B. Pequeño was the recipient of a grant for pre-doctoral researchers from AEI (PRE2018-085637).Peer reviewe

Protein Translation and Cell Death: The Role of Rare tRNAs in Biofilm Formation and in Activating Dormant Phage Killer Genes

We discovered previously that the small Escherichia coli proteins Hha (hemolysin expression modulating protein) and the adjacent, poorly-characterized YbaJ are important for biofilm formation; however, their roles have been nebulous. Biofilms are intricate communities in which cell signaling often converts single cells into primitive tissues. Here we show that Hha decreases biofilm formation dramatically by repressing the transcription of rare codon tRNAs which serves to inhibit fimbriae production and by repressing to some extent transcription of fimbrial genes fimA and ihfA. In vivo binding studies show Hha binds to the rare codon tRNAs argU, ileX, ileY, and proL and to two prophage clusters D1P12 and CP4-57. Real-time PCR corroborated that Hha represses argU and proL, and Hha type I fimbriae repression is abolished by the addition of extra copies of argU, ileY, and proL. The repression of transcription of rare codon tRNAs by Hha also leads to cell lysis and biofilm dispersal due to activation of prophage lytic genes rzpD, yfjZ, appY, and alpA and due to induction of ClpP/ClpX proteases which activate toxins by degrading antitoxins. YbaJ serves to mediate the toxicity of Hha. Hence, we have identified that a single protein (Hha) can control biofilm formation by limiting fimbriae production as well as by controlling cell death. The mechanism used by Hha is the control of translation via the availability of rare codon tRNAs which reduces fimbriae production and activates prophage lytic genes. Therefore, Hha acts as a toxin in conjunction with co-transcribed YbaJ (TomB) that attenuates Hha toxicity

Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world. Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231. Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001). Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication