Neural engineering with photons as synaptic transmitters.

Neuronal computation is achieved through connections of individual neurons into a larger network. To expand the repertoire of endogenous cellular communication, we developed a synthetic, photon-assisted synaptic transmission (PhAST) system. PhAST is based on luciferases and channelrhodopsins that enable the transmission of a neuronal state across space, using photons as neurotransmitters. PhAST overcomes synaptic barriers and rescues the behavioral deficit of a glutamate mutant with conditional, calcium-triggered photon emission between two neurons of the Caenorhabditis elegans nociceptive avoidance circuit. To demonstrate versatility and flexibility, we generated de novo synaptic transmission between two unconnected cells in a sexually dimorphic neuronal circuit, suppressed endogenous nocifensive response through activation of an anion channelrhodopsin and switched attractive to aversive behavior in an olfactory circuit. Finally, we applied PhAST to dissect the calcium dynamics of the temporal pattern generator in a motor circuit for ovipositioning. In summary, we established photon-based synaptic transmission that facilitates the modification of animal behavior.

Author Correction: Spatially resolved steady-state negative capacitance.

In this Letter, the first name of author Bhagwati Prasad was misspelled Bhagawati. This error has been corrected online.

Spatially resolved steady-state negative capacitance.

Negative capacitance is a newly discovered state of ferroelectric materials that holds promise for electronics applications by exploiting a region of thermodynamic space that is normally not accessible1-14. Although existing reports of negative capacitance substantiate the importance of this phenomenon, they have focused on its macroscale manifestation. These manifestations demonstrate possible uses of steady-state negative capacitance-for example, enhancing the capacitance of a ferroelectric-dielectric heterostructure4,7,14 or improving the subthreshold swing of a transistor8-12. Yet they constitute only indirect measurements of the local state of negative capacitance in which the ferroelectric resides. Spatial mapping of this phenomenon would help its understanding at a microscopic scale and also help to achieve optimal design of devices with potential technological applications. Here we demonstrate a direct measurement of steady-state negative capacitance in a ferroelectric-dielectric heterostructure. We use electron microscopy complemented by phase-field and first-principles-based (second-principles) simulations in SrTiO3/PbTiO3 superlattices to directly determine, with atomic resolution, the local regions in the ferroelectric material where a state of negative capacitance is stabilized. Simultaneous vector mapping of atomic displacements (related to a complex pattern in the polarization field), in conjunction with reconstruction of the local electric field, identify the negative capacitance regions as those with higher energy density and larger polarizability: the domain walls where the polarization is suppressed.

Interlayer Coupling Controlled Ordering and Phases in Polar Vortex Superlattices.

The recent discovery of polar topological structures has opened the door for exciting physics and emergent properties. There is, however, little methodology to engineer stability and ordering in these systems, properties of interest for engineering emergent functionalities. Notably, when the surface area is extended to arbitrary thicknesses, the topological polar texture becomes unstable. Here we show that this instability of the phase is due to electrical coupling between successive layers. We demonstrate that this electrical coupling is indicative of an effective screening length in the dielectric, similar to the conductor-ferroelectric interface. Controlling the electrostatics of the superlattice interfaces, the system can be tuned between a pure topological vortex state and a mixed classical-topological phase. This coupling also enables engineering coherency among the vortices, not only tuning the bulk phase diagram but also enabling the emergence of a 3D lattice of polar textures.

Understanding Pressure Effects on Structural, Optical, and Magnetic Properties of CsMnF4 and Other 3dn Compounds.

The pressure dependence of structural, optical, and magnetic properties of the layered compound CsMnF4 are explored through first-principles calculations. The structure at ambient pressure does not arise from a Jahn-Teller effect but from an orthorhombic instability on MnF63- units in the tetragonal parent phase, while there is a P4/n → P4 structural phase transition at P = 40 GPa discarding a spin crossover transition from S = 2 to S = 1. The present results reasonably explain the evolution of spin-allowed d-d transitions under pressure, showing that the first transition undergoes a red-shift under pressure following the orthorhombic distortion in the layer plane. The energy of such a transition at zero pressure is nearly twice that observed in Na3MnF6 due to the internal electric field and the orthorhombic distortion also involved in K2CuF4. The reasons for the lack of orthorhombic distortion in K2MF4 (M = Ni, Mn) or CsFeF4 are also discussed in detail. The present calculations confirm the ferromagnetic ordering of layers in CsMnF4 at zero pressure and predict a shift to an antiferromagnetic phase for pressures above 15 GPa consistent with the reduction of the orthorhombicity of the MnF63- units. This study underlines the usefulness of first-principles calculations for a right interpretation of experimental findings.

Supportive therapy following peri-implantitis treatment: A retrospective study on compliance.

BACKGROUND: The compliance rate with supportive therapy following peri-implantitis treatment (SPIT) remains unknown. The present retrospective study was carried out to assess the compliance rate and the factors influencing compliance in a private practice setting. MATERIALS AND METHODS: Patients were divided into three groups according to compliance rate: regular compliance (RC ≥2 SPIT/year), erratic compliance (EC <2 SPIT/year), and non-compliance (NC <1 SPIT/year). Overall, 17 patient- (n = 8) and site-related variables (n = 9) were explored as potential confounders of compliance. The Chi2 test was applied to assess the association between categorical variables and determine the odds ratio (OR). RESULTS: The study comprised 159 patients restored with 1075 implants, of which 469 were treated for peri-implantitis and met the inclusion criteria. A total of 57.2% were RC, 25.8% EC, and 17% NC. The multivariate analysis showed that smoking and grade C periodontitis reduced the likelihood of RC (OR = 0.28, p < .001) when compared to complete edentulism or non-smoking. Moreover, age demonstrated being associated with follow-up when SPIT was interrupted in EC and NC (OR = 0.94, p = .007). CONCLUSION: Comprehensive information, provided prior to peri-implantitis treatment, regarding the importance of adhering to SPIT after peri-implantitis treatment to achieve/maintain peri-implant health, resulted in ~60% regular compliance rate (NCT05772078).

Pure Chiral Polar Vortex Phase in PbTiO3/SrTiO3 Superlattices with Tunable Circular Dichroism.

Nontrivial polarization textures have been demonstrated in ferroelectric/dielectric superlattices, where the electrostatic, elastic, and different gradient energies compete in a delicate balance. When PbTiO3/SrTiO3 superlattices are grown on DyScO3, the coexistence of ferroelectric domains and vortex structure is observed for n = 12-20 unit cells. Here, we report an approach to achieve single-phase vortex structures in superlattices by controlling the epitaxial strain using Sr1.04Al0.12Ga0.35Ta0.50O3 substrates. The domain width follows Kittel's law with the thickness of the ferroelectric PbTiO3 layers. A phase transition from vortex to a disordered phase with temperature is characterized by the correlation length. Resonant soft X-ray diffraction circular dichroism at the titanium L-edge reveals enhanced chirality with the thickness of the ferroelectric layer. These results are supported by second-principles simulations, which demonstrate that the integrated helicity increases with n. The stabilization of chiral single-phase polar vortices in ferroelectric/dielectric superlattices can enable novel optoelectronic devices with enhanced ferroelectric-light interaction.

Multiple neoplasms in patients with uveal melanoma: a systematic review.

PURPOSE: Uveal melanoma is the most prevalent intraocular malignancy in adults, derived from uveal tract melanocytes. This study focuses on the frequency and risk of second primary malignancies in UM patients. METHODS: A PubMed search (1980-2023) identified studies on SPM incidence in UM patients. From 191 references, 14 studies were chosen, focusing on UM, SPMs, and analysing data on demographics and types of neoplasms. RESULTS: Among 31,235 UM patients in 14 studies, 4695 had 4730 SPMs (15.03% prevalence). Prostate (15%), breast (12%), and colorectal (9%) cancers were most common. Digestive system malignancies were highest (19%), with colorectal cancer leading (51%). Breast and prostate cancers were prevalent in respective systems. Lung, bladder, and non-Hodgkin's lymphoma were also notable. The study observed an increasing trend in the frequency of SPMs over time, reflecting broader trends in cancer survivorship and the growing prevalence of multiple malignancies. CONCLUSION: The study highlights a significant presence of SPMs in UM patients, with an increasing trend in frequency over time, emphasizing prostate and breast cancers. This underscores the need for focused surveillance and tailored follow-up for UM survivors, considering their higher risk of additional malignancies. Future research should further investigate SPM aetiology in UM patients.

Khinchin Families, Set Constructions, Partitions and Exponentials.

In this paper, we give a simple criterion to verify that functions of the form eg are in the Hayman class when g is a power series with nonnegative coefficients. Thus, using the Hayman and Báez-Duarte formulas, we obtain asymptotics for the coefficients of generating functions that arise in many examples of set construction in analytic combinatorics. This new criterion greatly simplifies the one obtained previously by the authors.

Development of Electrochemical Cells and Their Application for Spatially Resolved Analysis Using a Multitechnique Approach: From Conventional Experiments to X-Ray Nanoprobe Beamlines.

Real (electro)catalysts are often heterogeneous, and their activity and selectivity depend on the properties of specific active sites. Therefore, unveiling the so-called structure-activity relationship is essential for a rational search for better materials and, consequently, for the development of the field of (electro-)catalysis. Thus, spatially resolved techniques are powerful tools as they allow us to characterize and/or measure the activity and selectivity of different regions of heterogeneous catalysts. To take full advantage of that, we have developed spectroelectrochemical cells to perform spatially resolved analysis using X-ray nanoprobe synchrotron beamlines and conventional pieces of equipment. Here, we describe the techniques available at the Carnaúba beamline at the Sirius-LNLS storage ring, and then we show how our cells enable obtaining X-ray (XRF, XRD, XAS, etc.) and vibrational spectroscopy (FTIR and Raman) contrast images. Through some proof-of-concept experiments, we demonstrate how using a multi-technique approach could render a complete and detailed analysis of an (electro)catalyst overall performance.

Rational Design of a Multifunctional Benzothiadiazole Derivative in Organic Photonics and Electronics.

In order to achieve a multifunctional compound with potential application in organic photonics and electronics, a multidonor benzothiadiazole derivative was rationally designed and synthesized employing microwave irradiation as energy source, increasing the process efficiency about yields and reaction times in comparison with conventional conditions. This powerful compound displayed solvatochromism and showed efficient behavior as red optical waveguide with low OLC around 10-2  dB µm-1 and with the capacity of light transmission in two directions. In addition, the proposed derivative acted as efficient p-type semiconductor in organic field-effect transistors (OFETs) with hole mobilities up 10-1  cm2  V-1 s-1 . This corroborates its multifunctional character, thus making it a potential candidate to be applied in hybrid organic field-effect optical waveguides (OFEWs).

Understanding Attachment, Emotional Regulation, and Childhood Adversity and Their Link to Chemsex.

Background: Although evidence shows that engaging in chemsex can be associated with poor mental health, little is known about the relationship between psychological factors and this type of drug use. We aim to explore associations between engagement in chemsex and several psychological variables (adverse life events, attachment styles, emotional regulation skills, self-care patterns) in a sample of gay, bisexual, and other men who have sex with men (GBMSM) with drug-related problems. Methods: A group of GBMSM engaged in chemsex (n = 41) and a control group of GBMSM (n = 39) completed an online survey to assess drug-related problems and the abovementioned psychological variables, in which both groups were compared. All analyses were adjusted for covariates showing significant differences between groups. Results: Compared to the control group, participants engaged in chemsex showed significantly higher frequencies of an avoidant-insecure attachment style and early adverse life events, regardless of all covariates (HIV status, job situation, and place of birth). Poorer emotional regulation and self-care patterns and a higher frequency of sexual abuse were also found in participants engaged in chemsex, though we cannot rule out the influence of HIV status on this second group of variables. Conclusions: Some people with drug-related problems engaged in chemsex might have suffered early adverse events and might have an avoidant-insecure attachment style. Moreover, those who have been diagnosed with HIV might show higher emotional dysregulation and poorer self-care patterns. These variables should be routinely evaluated in this population.

Electromyographic Activity of the Pelvic Floor Muscles and Internal Oblique Muscles in Women during Running with Traditional and Minimalist Shoes: A Cross-Over Clinical Trial.

The study aimed to investigate the effects of footwear on the electromyographic (EMG) activity of pelvic floor muscles (PFMs) and internal oblique (IO) muscles during running at different speeds. The study also aimed to explore the correlation between EMG activity of PFMs and IO muscles and participants' morphological characteristics. Ten nulliparous female runners were included in the study. The participants ran for 90 s at speeds of 9, 11, and 13 km/h wearing both traditional and minimalist shoes. EMG outcomes were presented as a percentage of maximum voluntary contraction (%MVC). Comparative analysis was conducted using the Wilcoxon rank test. Correlational analysis was performed using the Rho-Spearman correlation coefficient. The %MVC for the IO muscles was significantly lower when using minimalist shoes compared to traditional shoes (p = 0.04). No statistically significant differences were found for the PFMs (p > 0.05). The study also observed large correlations between age and %MVC of the PFMs and IO muscles (rho = -0.64; p = 0.04). Minimalist shoes decreased the activity of IO muscles in female runners. However, no significant differences in EMG activity of PFMs were found when comparing traditional and minimalist footwear. The long-term effects of minimalist footwear on EMG activity of PFMs and IO muscles, as well as their relationship to morphological characteristics, require further investigation.

Bioactive Compounds in Plasma as a Function of Sex and Sweetener Resulting from a Maqui-Lemon Beverage Consumption Using Statistical and Machine Learning Techniques.

The present study analyses the effect of a beverage composed of citrus and maqui (Aristotelia chilensis) with different sweeteners on male and female consumers. Beverages were designed and tested (140 volunteers) as a source of polyphenols, in a previous work. Plasma samples were taken before and after two months of daily intake. Samples were measured for bioactive-compound levels with metabolomics techniques, and the resulting data were analysed with advanced versions of ANOVA and clustering analysis, to describe the effects of sex and sweetener factors on bioactive compounds. To improve the results, machine learning techniques were applied to perform feature selection and data imputation. The results reflect a series of compounds which are more regulated for men, such as caffeic acid or 3,4-dihydroxyphenylacetic acid, and for women, trans ferulic acid (TFA) or naringenin glucuronide. Regulations are also observed with sweeteners, such as TFA with stevia in women, or vanillic acid with sucrose in men. These results show that there is a differential regulation of these two families of polyphenols by sex, and that this is influenced by sweeteners.

Healthcare utilization and maternal and child mortality during the COVID-19 pandemic in 18 low- and middle-income countries: An interrupted time-series analysis with mathematical modeling of administrative data.

BACKGROUND: The Coronavirus Disease 2019 (COVID-19) pandemic has had wide-reaching direct and indirect impacts on population health. In low- and middle-income countries, these impacts can halt progress toward reducing maternal and child mortality. This study estimates changes in health services utilization during the pandemic and the associated consequences for maternal, neonatal, and child mortality. METHODS AND FINDINGS: Data on service utilization from January 2018 to June 2021 were extracted from health management information systems of 18 low- and lower-middle-income countries (Afghanistan, Bangladesh, Cameroon, Democratic Republic of the Congo (DRC), Ethiopia, Ghana, Guinea, Haiti, Kenya, Liberia, Madagascar, Malawi, Mali, Nigeria, Senegal, Sierra Leone, Somalia, and Uganda). An interrupted time-series design was used to estimate the percent change in the volumes of outpatient consultations and maternal and child health services delivered during the pandemic compared to projected volumes based on prepandemic trends. The Lives Saved Tool mathematical model was used to project the impact of the service utilization disruptions on child and maternal mortality. In addition, the estimated monthly disruptions were also correlated to the monthly number of COVID-19 deaths officially reported, time since the start of the pandemic, and relative severity of mobility restrictions. Across the 18 countries, we estimate an average decline in OPD volume of 13.1% and average declines of 2.6% to 4.6% for maternal and child services. We projected that decreases in essential health service utilization between March 2020 and June 2021 were associated with 113,962 excess deaths (110,686 children under 5, and 3,276 mothers), representing 3.6% and 1.5% increases in child and maternal mortality, respectively. This excess mortality is associated with the decline in utilization of the essential health services included in the analysis, but the utilization shortfalls vary substantially between countries, health services, and over time. The largest disruptions, associated with 27.5% of the excess deaths, occurred during the second quarter of 2020, regardless of whether countries reported the highest rate of COVID-19-related mortality during the same months. There is a significant relationship between the magnitude of service disruptions and the stringency of mobility restrictions. The study is limited by the extent to which administrative data, which varies in quality across countries, can accurately capture the changes in service coverage in the population. CONCLUSIONS: Declines in healthcare utilization during the COVID-19 pandemic amplified the pandemic's harmful impacts on health outcomes and threaten to reverse gains in reducing maternal and child mortality. As efforts and resource allocation toward prevention and treatment of COVID-19 continue, essential health services must be maintained, particularly in low- and middle-income countries.

Layered gallium sulfide optical properties from monolayer to CVD crystalline thin films.

Interest in layered van der Waals semiconductor gallium monosulfide (GaS) is growing rapidly because of its wide band gap value between those of two-dimensional transition metal dichalcogenides and of insulating layered materials such as hexagonal boron nitride. For the design of envisaged optoelectronic, photocatalytic and photonic applications of GaS, the knowledge of its dielectric function is fundamental. Here we present a combined theoretical and experimental investigation of the dielectric function of crystalline 2H-GaS from monolayer to bulk. Spectroscopic imaging ellipsometry with micron resolution measurements are corroborated by first principle calculations of the electronic structure and dielectric function. We further demonstrate and validate the applicability of the established dielectric function to the analysis of the optical response of c-axis oriented GaS layers grown by chemical vapor deposition (CVD). These optical results can guide the design of novel, to our knowledge, optoelectronic and photonic devices based on low-dimensional GaS.

Structural Chirality of Polar Skyrmions Probed by Resonant Elastic X-Ray Scattering.

An escalating challenge in condensed-matter research is the characterization of emergent order-parameter nanostructures such as ferroelectric and ferromagnetic skyrmions. Their small length scales coupled with complex, three-dimensional polarization or spin structures makes them demanding to trace out fully. Resonant elastic x-ray scattering (REXS) has emerged as a technique to study chirality in spin textures such as skyrmions and domain walls. It has, however, been used to a considerably lesser extent to study analogous features in ferroelectrics. Here, we present a framework for modeling REXS from an arbitrary arrangement of charge quadrupole moments, which can be applied to nanostructures in materials such as ferroelectrics. With this, we demonstrate how extended reciprocal space scans using REXS with circularly polarized x rays can probe the three-dimensional structure and chirality of polar skyrmions. Measurements, bolstered by quantitative scattering calculations, show that polar skyrmions of mixed chirality coexist, and that REXS allows valuation of relative fractions of right- and left-handed skyrmions. Our quantitative analysis of the structure and chirality of polar skyrmions highlights the capability of REXS for establishing complex topological structures toward future application exploits.

Pressure Effects on 3dn (n=4, 9) Insulating Compounds: Long Axis Switch in Na3 MnF6 not Due to the Jahn-Teller Effect.

The pressure-induced switch of the long axis of MnF6 3- units in the monoclinic Na3 MnF6 compound and Mn3+ -doped Na3 FeF6 is explored with the help of first principles calculations. Although the switch phenomenon is usually related to the Jahn-Teller effect, we show that, due to symmetry reasons, it cannot take place in 3dn (n=4, 9) systems displaying a static Jahn-Teller effect. By contrast, we prove that in Na3 MnF6 the switch arises from the anisotropic response of the low symmetry lattice to hydrostatic pressure. Indeed, while the long axis of a MnF6 3- unit at ambient pressure corresponds to the Mn3+ -F3 - direction, close to the crystal c axis, at 2.79 GPa the c axis is reduced by 0.29 Šwhile b is unmodified. This fact is shown to force a change of the HOMO wavefunction favoring that the long axis becomes the Mn3+ -F2 - direction, not far from crystal b axis, after the subsequent relaxation process. The origin of the different d-d transitions observed for Na3 MnF6 and CrF2 at ambient pressure is also discussed together with changes induced by pressure in Na3 MnF6 . The present work opens a window for understanding the pressure effects upon low symmetry insulating compounds containing d4 or d9 ions.

Assessing parasite epidemiology in the epidemiological importance of Patagonian Late Holocene rockshelters using carnivore coprolites in the past: new data from Piedra Parada, Argentina.

The aim of this research was to analyse the variability of parasite assemblages on a small spatial scale, by examining carnivore coprolites from the archaeological site Campo Moncada 2 (CM2), Piedra Parada area, Chubut province, Argentina, and comparing the results with those previously obtained from the archaeological site Campo Cerda 1 (CCe1), located in the same area. Six carnivore coprolites from CM2 were analysed: 4 obtained in sub-level 2a and 2 obtained in sub-level 2a/b. Two radiocarbon dates associated with the coprolites placed the samples chronologically between 780 ± 80 and 860 ± 80 years before present. The rehydrated sediments were sieved and then allowed to sediment spontaneously. The sediment was used for parasitological examination under light microscopy. Conservative estimation of total parasite richness resulted in 21 parasitic taxa. The taxa with the highest fecal prevalence (>50%) corresponded to parasites prevalent in modern carnivores (Alaria sp., Toxocara cf. canis, Toxascaris sp., Eucoleus cf. aerophila, Trichuris sp. and Ancylostomatidae gen. sp.). Assuming that the fox coprolites are contemporaneous, the total fecal parasite richness estimated for CM2 and previously for CCe1 was similar. The high total parasite richness found suggests a network of host­parasite relationships that could include regional hunter-gatherers. The results obtained in carnivore coprolites allow us to infer a very diverse biological community in Piedra Parada area, so the regional caves and rockshelters could have a proportional epidemiological importance as parasite exchange nodes.

Subarachnoid Hemorrhage and Extracorporeal Blood Purification with HA-380 and High-Volume Hemofiltration: A New Therapeutic Challenge at the Neurocritical Care Unit? A Case Report.

We present the case of a patient with subarachnoid hemorrhage (SAH) secondary to a ruptured cerebral aneurysm and a refractory shock with high doses of vasopressors without a proven source of infection. This patient received therapy with high-volume hemofiltration plus adsorption, resolving the hemodynamic deterioration and with good neurological evolution. Our clinical case proposes that extracorporeal therapies may have a feasibility role in the management of complications of SAH.