Odontoblast TRPC5 channels signal cold pain in teeth

Teeth are composed of many tissues, covered by an inflexible and obdurate enamel. Unlike most other tissues, teeth become extremely cold sensitive when inflamed. The mechanisms of this cold sensation are not understood. Here, we clarify the molecular and cellular components of the dental cold sensing system and show that sensory transduction of cold stimuli in teeth requires odontoblasts. TRPC5 is a cold sensor in healthy teeth and, with TRPA1, is sufficient for cold sensing. The odontoblast appears as the direct site of TRPC5 cold transduction and provides a mechanism for prolonged cold sensing via TRPC5\u27s relative sensitivity to intracellular calcium and lack of desensitization. Our data provide concrete functional evidence that equipping odontoblasts with the cold-sensor TRPC5 expands traditional odontoblast functions and renders it a previously unknown integral cellular component of the dental cold sensing system

Search for coherent elastic neutrino-nucleus scattering at a nuclear reactor with CONNIE 2019 data

The Coherent Neutrino-Nucleus Interaction Experiment (CONNIE) is taking data at the Angra 2 nuclear reactor with the aim of detecting the coherent elastic scattering of reactor antineutrinos with silicon nuclei using charge-coupled devices (CCDs). In 2019 the experiment operated with a hardware binning applied to the readout stage, leading to lower levels of readout noise and improving the detection threshold down to 50 eV. The results of the analysis of 2019 data are reported here, corresponding to the detector array of 8 CCDs with a fiducial mass of 36.2 g and a total exposure of 2.2 kg-days. The difference between the reactor-on and reactor-off spectra shows no excess at low energies and yields upper limits at 95% confidence level for the neutrino interaction rates. In the lowest-energy range, 50 − 180 eV, the expected limit stands at 34 (39) times the standard model prediction, while the observed limit is 66 (75) times the standard model prediction with Sarkis (Chavarria) quenching factors

Determining the WIMP mass using the complementarity between direct and indirect searches and the ILC

We study the possibility of identifying dark matter properties from XENON-like 100 kg experiments and the GLAST satellite mission. We show that whereas direct detection experiments will probe efficiently light WIMPs, given a positive detection (at the 10% level for $m_{\chi} \lesssim 50$ GeV), GLAST will be able to confirm and even increase the precision in the case of a NFW profile, for a WIMP-nucleon cross-section $\sigma_{\chi-p} \lesssim 10^{-8}$ pb. We also predict the rate of production of a WIMP in the next generation of colliders (ILC), and compare their sensitivity to the WIMP mass with the XENON and GLAST projects.Comment: 32 pages, new figures and a more detailed statistical analysis. Final version to appear in JCA

O treinamento da musculatura inspiratória é ineficiente em pacientes graves submetidos à ventilação mecânica

PURPOSE: Invasive mechanical ventilation is associated with complications, and its abbreviation is desirable. The imbalance between increased workload, decreased inspiratory muscle strength and endurance is an important determinant of ventilator dependence. Low endurance may be present due to respiratory muscle atrophy, critical illness, or steroid use. Specific inspiratory muscle training may increase or preserve endurance. The objective of the study was to test the hypothesis that inspiratory muscle training from the beginning of mechanical ventilation would abbreviate the weaning duration and decrease reintubation rate. As a secondary objective, we described the evolution of inspiratory muscle strength with and without inspiratory muscle training. METHODS: Prospective, randomized clinical trial in an adult clinical-surgical intensive care unit. Twelve patients trained the inspiratory muscles twice a day, and 13 patients did not (control). Training was performed adjusting the sensitivity of the ventilator based on the maximal inspiratory pressure. Patients underwent daily surveillance of the maximal inspiratory pressure. RESULTS: The weaning duration (31 ± 22 hr, control and 23 ± 11 hr, training group; P = .24) and reintubation rate (5 control and 3 training group; P = .39) were not statistically different. The maximal inspiratory pressure of the control group showed a trend toward a modest increase. In contrast, the training group showed a small decrease (P = .34). CONCLUSIONS: In acute critically ill patients, inspiratory muscle training from the beginning of mechanical ventilation neither abbreviated the weaning duration, nor decreased the reintubation rate. Inspiratory muscle strength tended to stay constant, along the mechanical ventilation, with or without this specific inspiratory muscle training.OBJETIVO: A ventilação mecânica invasiva é associada a complicações, portanto sua abreviação é desejada. O desbalanço entre o aumento da carga sobre os músculos inspiratórios, a diminuição da força e a resistência muscular é determinante na dependência da ventilação. A baixa resistência muscular pode ser causada por atrofia muscular, pela doença grave ou pelo uso de corticoesteróides. O treinamento da musculatura inspiratória pode aumentar ou preservar a resistência. O objetivo principal do estudo foi testar a hipótese que o treinamento da musculatura inspiratória desde o início da ventilação iria abreviar o desmame da ventilação e diminuir a taxa de reintubação. Como objetivo secundário descrevemos a evolução da pressão inspiratória máxima com e sem treinamento da musculatura inspiratória. MÉTODOS: Estudo prospectivo e aleatorizado em unidade de tratamento intensivo Clínico-Cirúrgica. Doze pacientes treinaram a musculatura inspiratória duas vezes ao dia e treze não treinaram (controle). O treinamento foi realizado ajustando a sensibilidade do ventilador, baseando-se na pressão inspiratória máxima. Os pacientes tiveram sua pressão inspiratória máxima verificada diariamente. RESULTADOS: A duração do desmame (31 ± 22 controle e 23 ± 11 horas grupo treinamento; p=0.24) não foi estatisticamente diferente. A pressão inspiratória máxima do grupo controle teve leve tendência ao aumento, enquanto o grupo treinamento teve leve tendência à diminuição. CONCLUSÃO: Em pacientes graves, o treinamento da musculatura inspiratória desde o início da ventilação mecânica não abreviou o desmame, nem diminuiu a reintubação. A pressão inspiratória máxima tendeu a manter-se constante ao longo da ventilação mecânica, com ou sem o treinamento inspiratório aplicado

Photodissociation of water in crystalline ice: a molecular dynamics study

Ultraviolet irradiation of ice is of great interest for understanding the chemistry in both atmospheric and astrophysical environments. In interstellar space, photodissociation of H2O molecules can be a driving force behind the chemistry on icy dust grains in dense, cold molecular clouds even though the flux of UV photons is extremely low. The mechanisms of such photoinduced processes are poorly understood, however. In this work the photodissociation dynamics of a water molecule in crystalline ice at 10 K is studied computationally using classical molecular dynamics. Photodissociation in the first bilayer leads mainly to H atoms desorbing (65%), while in the third bilayer trapping of H and OH dominates (51%). The kinetic energy distribution of the desorbing H atoms is much broader than that for the corresponding gas-phase photodissociation. The H atoms on average move 11 Angstroms before becoming trapped, while OH radicals typically move 2 Angstroms. In accordance with experiments a blueshift of the absorption spectrum is obtained relative to gas-phase water.Comment: 23 pages, 5 figure