Analytical Solution for Electrical Problem Forced by a Finite-Length Needle Electrode: Implications in Electrostimulation

[EN] Needle electrodes, widely used in clinical procedures, are responsible for creating an electric field in the treated biological tissue. This is achieved by setting a constant voltage along the length of their metallic section. In accordance with Laplace's equation, the electric field is spatially non-uniform around the electrode surface. Mathematical modelling can provide useful information on the spatial distribution of electrical fields. Indeed, exact solutions for the electrical problem are indispensable for validating numerical codes. All the analytical models developed to date to solve the needle electrode electrical problem have been one-dimensional models, which assumed an electrode of infinite length. We here propose the first analytical solution based on a two-dimensional model that considers the real length of the electrode in which the Laplace equation is solved through the method of separation of variables, dealing with the nonhomogeneous source term and boundary conditions by Green's functions. On assuming a needle electrode of given length, the problem combines boundary conditions on the electrode boundary (of the first and second kind). Since this rules out using the Sturm-Liouville Theorem, the problem is decomposed into two different problems and the principle of superposition is used. The solution obtained can reproduce a reasonable electric field around the electrode, especially the edge effect characterized by an extremely high gradient around the electrode tip.This work was supported by the Universidad Autonoma de San Luis Potosi (Mexico), which granted R. Romero-Mendez who is on a sabbatical leave to do research in the field of biomedical engineering. This work was supported by the Spanish Ministerio de Ciencia, Innovacion y Universidades under "Programa Estatal de I+D+i Orientada a los Retos de la Sociedad" (grant number: RTI2018-094357-B-C21).Romero-Méndez, R.; Pérez-Gutiérrez, FG.; Oviedo-Tolentino, F.; Berjano, E. (2019). Analytical Solution for Electrical Problem Forced by a Finite-Length Needle Electrode: Implications in Electrostimulation. Mathematical Problems in Engineering. 1-10. https://doi.org/10.1155/2019/2404818S110Mulier, S., Miao, Y., Mulier, P., Dupas, B., Pereira, P., de Baere, T., … Ni, Y. (2005). Electrodes and multiple electrode systems for radiofrequency ablation: a proposal for updated terminology. European Radiology, 15(4), 798-808. doi:10.1007/s00330-004-2584-xMerrill, D. R., Bikson, M., & Jefferys, J. G. R. (2005). Electrical stimulation of excitable tissue: design of efficacious and safe protocols. Journal of Neuroscience Methods, 141(2), 171-198. doi:10.1016/j.jneumeth.2004.10.020Cogan, S. F. (2008). Neural Stimulation and Recording Electrodes. Annual Review of Biomedical Engineering, 10(1), 275-309. doi:10.1146/annurev.bioeng.10.061807.160518Kwon, H., Rutkove, S. B., & Sanchez, B. (2017). Recording characteristics of electrical impedance myography needle electrodes. Physiological Measurement, 38(9), 1748-1765. doi:10.1088/1361-6579/aa80acBurdío, F., Berjano, E. J., Navarro, A., Burdío, J. M., Güemes, A., Grande, L., … de Gregorio, M. A. (2007). RF tumor ablation with internally cooled electrodes and saline infusion: what is the optimal location of the saline infusion? BioMedical Engineering OnLine, 6(1), 30. doi:10.1186/1475-925x-6-30Zhang, B., Moser, M. A. J., Zhang, E. M., Luo, Y., Liu, C., & Zhang, W. (2016). A review of radiofrequency ablation: Large target tissue necrosis and mathematical modelling. Physica Medica, 32(8), 961-971. doi:10.1016/j.ejmp.2016.07.092Samoudi, A. M., Kampusch, S., Tanghe, E., Széles, J. C., Martens, L., Kaniusas, E., & Joseph, W. (2017). Numerical modeling of percutaneous auricular vagus nerve stimulation: a realistic 3D model to evaluate sensitivity of neural activation to electrode position. Medical & Biological Engineering & Computing, 55(10), 1763-1772. doi:10.1007/s11517-017-1629-7Samoudi, A. M., Vermeeren, G., Tanghe, E., Van Holen, R., Martens, L., & Josephs, W. (2016). Numerically simulated exposure of children and adults to pulsed gradient fields in MRI. Journal of Magnetic Resonance Imaging, 44(5), 1360-1367. doi:10.1002/jmri.25257Trujillo, M., Bon, J., José Rivera, M., Burdío, F., & Berjano, E. (2016). Computer modelling of an impedance-controlled pulsing protocol for RF tumour ablation with a cooled electrode. International Journal of Hyperthermia, 32(8), 931-939. doi:10.1080/02656736.2016.1190868Ewertowska, E., Mercadal, B., Muñoz, V., Ivorra, A., Trujillo, M., & Berjano, E. (2017). Effect of applied voltage, duration and repetition frequency of RF pulses for pain relief on temperature spikes and electrical field: a computer modelling study. International Journal of Hyperthermia, 34(1), 112-121. doi:10.1080/02656736.2017.1323122Zhang, B., Moser, M. A. J., Zhang, E. M., Luo, Y., & Zhang, W. (2016). A new approach to feedback control of radiofrequency ablation systems for large coagulation zones. International Journal of Hyperthermia, 33(4), 367-377. doi:10.1080/02656736.2016.1263365Haemmerich, D., Chachati, L., Wright, A. S., Mahvi, D. M., Lee, F. T., & Webster, J. G. (2003). Hepatic radiofrequency ablation with internally cooled probes: effect of coolant temperature on lesion size. IEEE Transactions on Biomedical Engineering, 50(4), 493-500. doi:10.1109/tbme.2003.809488López Molina, J. A., Rivera, M. J., & Berjano, E. (2017). Analytical transient-time solution for temperature in non perfused tissue during radiofrequency ablation. Applied Mathematical Modelling, 42, 618-635. doi:10.1016/j.apm.2016.10.044Romero-Méndez, R., & Berjano, E. (2017). An Analytical Solution for Radiofrequency Ablation with a Cooled Cylindrical Electrode. Mathematical Problems in Engineering, 2017, 1-12. doi:10.1155/2017/9021616Verhey, J., Nathan, N., Rienhoff, O., Kikinis, R., Rakebrandt, F., & D’Ambra, M. (2006). BioMedical Engineering OnLine, 5(1), 17. doi:10.1186/1475-925x-5-1

Auto-Pressurized Multi-Stage Tesla-Valve Type Microreactors in Carbon Monoliths Obtained Through 3D Printing: Impact of Design on Fluid Dynamics and Catalytic Activity

The present research exploits an innovative methodology for producing auto-pressurized carbon microreactors with a precise and controlled structure analyzing the influence of their design on the fluid dynamics and their catalytic performance. Carbon monoliths with Tesla-valve shape channels (Tesla, T, and modified Tesla, Tm) are synthesized through the combination of 3D printing and sol–gel process and further probed as Ni/CeO2 supports on CO2 methanation. The experimental results and mathematical modeling corroborated the improved performance obtained through the complex design compared to a conventional one. In addition to chaotic fluid flow induced by the deviation in flow direction, which improves the reagents-active phase interaction, local pressure increases due to convergence of flows may enhance the Sabatier reaction according to Le Châtelier's principle. Conversely to straight channels, T and Tm are not affected by flow rate and presented chemical control. Tesla-valve with curved angle (Tm) improved the mass transfer, achieving higher conversion and ≈30% reaction rate increase regarding right angle (T). Thus, this auto-pressurized multi-stage Tesla-valve monolith opens the gate to design specific and advanced functional materials for multitude chemical reactions where not only the reactant-active phase contact can be maximized but also the reaction conditions can be controlled to maximize the reaction kinetics.This research had been supported by the Spanish project PID2021-127803OB-I00 funded by MCIN/AEI/ 10.13039/501100011033/ and by “ERDF A way of making Europe”. Authors also thanks the “Unidad de Excelencia Química Aplicada a Biomedicina y Medioambiente” of the University of Granada (UEQ – UGR) for its technical assistance. A. Parra-Marfil appreciates the financial support provided by CONAHCYT through the PhD grant 818974. E. Bailón-García was grateful to MICINN for her postdoctoral fellowship (RYC2020-029301-I). A. Bueno López thanks the financial support of Generalitat Valenciana (Project CIPROM/2021/74)

Clinical Characteristics and Risk Factors For Mortality During the \u27First Wave\u27 of COVID-19 In Reynosa, Tamaulipas

Background: The COVID-19 pandemic has impacted public health in Mexico. As of February 2020, there have been at least four waves of contagion that resulted in 5.82 million positive cases and more than 325 thousand deaths. At the beginning of the COVID-19 pandemic, hospital and population-based information was available, frequently with non-specific symptoms. Little was known about the risk factors for mortality in specific conditions. We described the clinical characteristics of patients with COVID-19 in Reynosa, Tamaulipas during 2020 and identified the risk factors for mortality. Methods: The COVID-19 cases registered from March to November 2020 in Reynosa were divided into survivors and non-survivors. The study had a retrospective cohort design. Data was obtained from the platform of the Respiratory Disease Surveillance System (SISVER), belonging to the National Epidemiological Surveillance System (SINAVE) of the Mexican Ministry of Health (https://sinave.gob.mx/). The variables considered were the age and gender of each patient. Twenty-five symptoms were included (fever, cough, headache, myalgia, arthralgia, among others); the outcome variable was the detection of COVID-19. Associated comorbidities were diabetes, obesity, hypertension, among others. The outcome variable was mortality. Data were analyzed using χ2 tests, Mann-Whitney tests, principal component analysis, and the Cox regression model. Results:The highest number of COVID-19 cases and deaths was observed in July, in men between 36-40 years old. The most frequent symptoms (37-51%) were headache, fever, cough, myalgia, and arthralgia. Clinical characteristics between survivors and non-survivors were significant (P Conclusions: The most frequent symptoms in positive COVID-19 patients in Reynosa during 2020 were headache, fever, cough, myalgia, and arthralgia. Age, gender and diabetes, hypertension, heart disease, COPD, and CKD increase mortality. The factors with the highest risk of death were age over 80 years, admitted to the ICU or intubated

Effect of Social Rank upon Estrus Induction and Some Reproductive Outcomes in Anestrus Goats Treated With Progesterone + eCG

We evaluated the possible role of the social rank [R] (i.e., low—LSR, middle—MSR, or high—HSR) in anestrus goats exposed to a P4 + eCG [D] (i.e., 100 or 350 IU) estrus induction protocol (EIP). Adult, multiparous (two to three lactations), multiracial, dairy-type goats (Alpine–Saanen–Nubian x Criollo goats (n = 70; 25°51′ North) managed under stall-fed conditions were all ultrasound evaluated to confirm anestrus status while the R was determined 30 d prior to the EIP. The variables of estrus induction (EI, %), estrus latency (LAT, h), estrus duration (DUR, h), ovulation (OVU, %), ovulation rate (OR, n), corpus luteum size (CLS, cm), pregnancy (PREG, %), kidding (KIDD, %), and litter size (LS, n) as affected by R, D, and the R × D interaction, were evaluated. While OVU and CLS favored (p 0.05; 38.5%) KIDD. However, EI, LAT, DUR, OR, and PREG were affected by the R × D interaction. The HSR group had the largest (p < 0.05) EI % and DUR h, irrespective of D. The shortest (p < 0.05) LAT occurred in D350, irrespective of R. While the largest (p < 0.05) OR occurred in HSR and MSR within D350, the HSR + D350 group had the largest PREG (p < 0.05). These research outcomes are central to defining out-of-season reproductive strategies designed to attenuate seasonal reproduction in goats

Goats as Valuable Animal Model to Test the Targeted Glutamate Supplementation upon Antral Follicle Number, Ovulation Rate, and LH-Pulsatility

The potential effect of intravenous administration of glutamate on the ovarian activity and the LH secretion pattern, considering the anestrous yearling goat as an animal model, were assessed. In late April, yearling goats (n = 20) were randomly assigned to either (1) Glutamate supplemented (GLUT; n = 10, Live Weight (LW) = 29.6 ± 1.02 kg, Body Condition (BCS) = 3.4 ± 0.2 units; i.v. supplemented with 7 mg GLUT kg−1 LW) or (2) Non-supplemented (CONT; n = 10; LW = 29.2 ± 1.07 kg, BCS = 3.5 ± 0.2 units; i.v. saline). The oats were estrus-synchronized; blood sampling (6 h × 15 min) was carried out for LH quantification. Response variables included pulsatility (PULSE), time to first pulse (TTFP), amplitude (AMPL), nadir (NAD), and area under the curve (AUC) of LH. Ovaries were ultra-sonographically scanned to assess ovulation rate (OR), number of antral follicles (AF), and total ovarian activity (TOA = OR + AF). LH-PULSE was quantified with the Munro algorithm; significant treatment x time interactions were evaluated across time. The variables LW and BCS did not differ (p > 0.05) between the experimental groups. Nevertheless, OR (1.77 vs. 0.87 ± 0.20 units), TOA (4.11 vs. 1.87 ± 0.47 units) and LH-PULSE (5.0 vs. 2.2 pulses 6 h-1) favored (p < 0.05) to the GLUT group. Our results reveal that targeted glutamate supplementation, the main central nervous system neurotransmitter, arose as an interesting strategy to enhance the hypothalamic–hypophyseal–ovarian response considering the anestrous-yearling goat as an animal model, with thought-provoking while promising translational applications

Does Size Matters? Relationships among Social Dominance and Some Morphometric Traits upon Out-of-Season Reproductive Outcomes in Anestrus Dairy Goats Treated with P4 + eCG

The possible role of the social rank (R) (i.e., low-LSR, middle-MSR, or high-HSR) in anestrus goats exposed to a P4 + eCG (D) (i.e., 100 or 350 IU) estrus induction protocol (EIP) was evaluated. Goats (Alpine-Saanen-Nubian × Criollo; n = 70; 25° North) managed under stall-fed conditions were all ultrasound evaluated to confirm anestrous status, while the social rank was determined 30 d prior to the EIP. The response variables included estrus induction (EI, %), duration of estrus (DUR, h), ovulation rate (OR, n), live weight (LW, kg), thoracic perimeter (TP, cm), thoracic diameter (TD, cm), body length (BL, cm), height at withers (HW, cm), beard length (BEA, cm), compactness index (COM, cm), and anamorphosis index (ANA, cm), as affected by R, D, and the R × D interaction were evaluated, while the correlation coefficients among reproductive and morphometric variables were quantified. An R × D interaction (p 0.05) with any response variable, either reproductive or morphometric. As expected, LW had high correlation coefficients (p < 0.01) with TP (0.86), TD (0.88), BL (0.82), HW (0.75), BEA (0.51), COM (0.97), and ANA (0.75). In general, the morphometric variables as a whole demonstrated important correlation coefficients among them (p < 0.01), ranging from 0.38 up to 0.84. To estimate the importance of the morphometric differences between social rank upon estrus induction, a principal component (PC) analysis was performed based on the correlation matrix derived from the corporal measurements. The PC1 and PC2 explained 70.3% and 17.6% of the morphometric variation, respectively. The PC1 was a measure of the goat size (i.e., small, medium, large) and its association with estrus occurrence was evaluated using a logistic regression model; the bigger the goat, the increased probability of being in estrus, by up to five times compared to small goats. Our results confirm that the higher social ranked, larger goats amalgamated some fundamental factors to be successful: aggressiveness, primacy to food access, augmented live weight, and corporal size; all of these were able to modulate out-of-season reproductive success in crossbred dairy goats subjected to an estrus induction protocol and managed under stall-fed conditions in Northern Mexico

Active and Passive Tuning of Ultranarrow Resonances in Polaritonic Nanoantennas

[EN] Optical nanoantennas are of great importance for photonic devices and spectroscopy due to their capability of squeezing light at the nanoscale and enhancing light-matter interactions. Among them, nanoantennas made of polar crystals supporting phonon polaritons (phononic nanoantennas) exhibit the highest quality factors. This is due to the low optical losses inherent in these materials, which, however, hinder the spectral tuning of the nanoantennas due to their dielectric nature. Here, active and passive tuning of ultranarrow resonances in phononic nanoantennas is realized over a wide spectral range (approximate to 35 cm(-1), being the resonance linewidth approximate to 9 cm(-1)), monitored by near-field nanoscopy. To do that, the local environment of a single nanoantenna made of hexagonal boron nitride is modified by placing it on different polar substrates, such as quartz and 4H-silicon carbide, or covering it with layers of a high-refractive-index van der Waals crystal (WSe2). Importantly, active tuning of the nanoantenna polaritonic resonances is demonstrated by placing it on top of a gated graphene monolayer in which the Fermi energy is varied. This work presents the realization of tunable polaritonic nanoantennas with ultranarrow resonances, which can find applications in active nanooptics and (bio)sensing.J.M.-S. acknowledges financial support from the Ramon y Cajal Program of the Government of Spain and FSE (Grant No. RYC2018-026196-I) and the Spanish Ministry of Science and Innovation (State Plan for Scientific and Technical Research and Innovation Grant Number PID2019-110308GA-I00). P.A.-G. acknowledges support from the European Research Council under starting Grant No. 715496, 2DNANOPTICA, and the Spanish Ministry of Science and Innovation (State Plan for Scientific and Technical Research and Innovation Grant Number PID2019-111156GB-I00). G.a.-P. and J.T.-G. acknowledge support through the Severo Ochoa Program from the Government of the Principality of Asturias (Grant nos. PA20-PF-BP19-053 and PA-18-PF-BP17-126, respectively). A.Y.N. acknowledges the Spanish Ministry of Science and Innovation (Grant Nos. MAT201788358-C3-3-R and PID2020-115221GB-C42) and the Basque Department of Education (Grant No. PIBA-2020-1-0014) J.H.E. acknowledges support for h-BN crystal growth from the National Science Foundation, Award Number CMMI-1538127. R.H. acknowledges financial support from the Spanish Ministry of Science, Innovation and Universities (National Project Grant No. RTI2018-094830-B-100 and the Project Grant No. MDM-2016-0618 of the Marie de Maeztu Units of Excellence Program), the Basque Government (Grant No. IT1164-19), and the European Union's Horizon 2020 research and innovation programme under the Graphene Flagship (Grant Agreement Numbers 785219 and 881603, GrapheneCore2 and GrapheneCore3). I.D. acknowledges the Basque Government (Grant No. PRE_2019_2_0164). Work at MIT was partly supported through AFOSR Grant No. FA9550-16-1-0382, through the NSF QII-TAQS program (Grant No. 1936263), and the Gordon and Betty Moore Foundation EPiQS Initiative through Grant No. GBMF9643 to P.J.-H

Unraveling the real magnitude of illegal wildlife poisoning to halt cryptic biodiversity loss

Illegal wildlife poisoning is a global threat for biodiversity, yet the magnitude of its impact on ecosystems is largely underestimated as most of poisoning episodes remain undetected. Here, we conducted a large-scale field experiment to better understand the real dimension of the illegal wildlife poisoning in terms of composition and number of species and abundance of impacted individuals, as well as the ecological factors driving it. We used camera traps to monitor simulated poison baits placed in 25 study areas in SW Europe and applied Good–Turing theory to estimate the richness of species of the entire assemblage (observed plus undetected). We recorded 3095 individuals from 39 vertebrate species that consumed 94 % of the baits (N = 590). Yet, using sample completeness to estimate the entire species assemblage yielded a total of 47 species exposed to illegal poisoning. The observed assemblage included different trophic and functional groups (from lizards and snakes to apex species among birds and mammals), as well as a 38 % of threatened and near threatened species (according to Spanish and Portuguese vertebrate red list and UICN list). The size (weight) of the bait outstands as a reliable predictor of the number of species (0–8 species/bait, mean = 2) and individuals (0–99 individuals/bait, mean = 5) susceptible to poisoning. The habitat where the bait was placed modulated the abundance of individuals affected (greater in open than in closed habitats). Type of bait and habitat drove the compositional variation of species. Our approach enables uncover entire species assemblages prone to illegal poisoning and their ecological drivers associated, advancing the understanding of the impact of wildlife poisoning in ecosystemsThis work was supported by the project TOXICO funding by “BBVA FOUNDATION GRANTS TO SCIENTIFIC RESEARCH TEAMS, CALL 2018”. WWF Spain and SEO/BirdLife provided access to the ANTíDOTO database of wildlife poisoning in Spain. The Ohio Wesleyan University supported with logistical material (5 camera-traps). JVLB was supported by the Spanish Ministry of Economy, Industry and Competitiveness (RYC-2015-18932; CGL2017-87528-R AEI/FEDER EU). JVLB and PMT were supported by a GRUPIN research grant from the Regional Government of Asturias (AYUD/2021/51314). In Portugal, this study was financed through the Sentinelas project funded by Fundo Ambiental – Minist´erio do Ambiente e da Aç˜ ao Clim´ atica. We are grateful to Instituto da Conservaçao ˜ da Natureza e das Florestas (ICNF), Principado de Asturias, Junta de Castilla y Leon, ´ Xunta de Galicia, Gobierno de Cantabria, Comunidad de Madrid, Junta de Andalucía, Picos de Europa National Park, Sierra de Guadarrama National Park, Cabaneros ˜ National Park and Monfragüe National Park for granted permission

Mesenchymal stromal cells express GARP/LRRC32 on their surface: Effects on their biology and immunomodulatory capacity

Mesenchymal stromal cells (MSCs) represent a promising tool for therapy in regenerative medicine, transplantation, and autoimmune disease due to their trophic and immunomodulatory activities. However, we are still far from understanding the mechanisms of action of MSCs in these processes. Transforming growth factor (TGF)-β1 is a pleiotropic cytokine involved in MSC migration, differentiation, and immunomodulation. Recently, glycoprotein A repetitions predominant (GARP) was shown to bind latency-associated peptide (LAP)/TGF-β1 to the cell surface of activated Foxp3+ regulatory T cells (Tregs) and megakaryocytes/platelets. In this manuscript, we show that human and mouse MSCs express GARP which presents LAP/TGF-β1 on their cell surface. Silencing GARP expression in MSCs increased their secretion and activation of TGF-β1 and reduced their proliferative capacity in a TGF-β1-independent manner. Importantly, we showed that GARP expression on MSCs contributed to their ability to inhibit T-cell responses in vitro. In summary, we have found that GARP is an essential molecule for MSC biology, regulating their immunomodulatory and proliferative activities. We envision GARP as a new target for improving the therapeutic efficacy of MSCs and also as a novel MSC marker. Stem Cells 2015;33:183-19

A Proposed Approach to Chronic Airway Disease (CAD) Using Therapeutic Goals and Treatable Traits: A Look to the Future

© 2020 Pérez de Llano et al.Chronic airflow obstruction affects a wide range of airway diseases, the most frequent of which are asthma, COPD, and bronchiectasis; they are clearly identifiable in their extremes, but quite frequently overlap in some of their pathophysiological and clinical characteristics. This has generated the description of new mixed or overlapping disease phenotypes with no clear biological grounds. In this special article, a group of experts provides their perspective and proposes approaching the treatment of chronic airway disease (CAD) through the identification of a series of therapeutic goals (TG) linked to treatable traits (TT) – understood as clinical, physiological, or biological characteristics that are quantifiable using biomarkers. This therapeutic approach needs validating in a clinical trial with the strategy of identification of TG and treatment according to TT for each patient independently of their prior diagnosis