PortAqua: a low-cost, compact water quality meter for science communication.

Water quality monitoring allows communities to achieve sustainable management of water resources, which is crucial for life-supporting processes. Water quality is determined by measuring chemical, physical, and biological parameters, requiring sophisticated meters and trained specialists to perform the measurement. However, in low-income communities, water quality is determined by using human senses-smell, color, and taste-since meter acquisition is limited by costs and most people do not know how to monitor water quality. Therefore, accessible technology is necessary to empower communities to have a sustainable lifestyle. In this paper, we present the design and implementation of PortAqua, a 2-parameter water quality meter (WQM), to promote training on water quality measurement. Using basic electronic components, PortAqua is capable of measuring pH with an error of 0.4, and conductivity with an error of 33% at 85 µS cm-1, and 8.7% at 1413 µS cm-1. To demonstrate its preliminary effectiveness as a WQM and its science communication capabilities, the meter has been used in a hands-on workshop with undergraduate and graduate students. During the workshop, attendees participated in a short lecture about water quality measurement techniques and local regulations. Then, they collected water samples from a local source, measured the samples using PortAqua, and discussed the results based on the concepts and regulations. The workshop's effectiveness was evaluated through pre- and post-assessments which revealed increased knowledge of water quality regulations, measurement, and parameters at the end of the activity.

Detailed Structural Features of the Perovskite-Related Halide RbPbI3 for Solar Cell Applications.

All-inorganic lead halide perovskites like CsPbBr3, CsPbI3, or RbPbI3 are good replacements for the classical hybrid organic-inorganic perovskites like CH3NH3PbI3, susceptible to fast degradation in the presence of humid air. They also exhibit outstanding light absorption properties suitable for solar energy applications. Here, we describe the synthesis of RbPbI3 by mechanochemical procedures with green credentials, avoiding toxic or expensive organic solvents; this specimen exhibits excellent crystallinity. We report neutron powder diffraction data, essential to revisit some subtle structural features around room temperature (200-400 K). In all these regimes, the orthorhombic Pnma crystal structure is characterized by the presence along the b direction of the crystal of double rows of edge-sharing PbI6 octahedra. The lone electron pairs of Pb2+ ions have a strong stereochemical effect on the PbI6 octahedral distortion. The relative covalency of Rb-I versus Pb-I bonds shows that the Pb-I-related motions are more rigid than Rb-I-related vibrations, as seen in the Debye temperatures from the evolution of the anisotropic displacements. The optical gap, measured by diffuse reflectance UV-vis spectroscopy, is ∼2.51 eV and agrees well with ab initio calculations. The thermoelectric Seebeck coefficient is 3 orders of magnitude larger than that of other halide perovskites, with a value of ∼117,000 µV·K-1 at 460 K.

Potential distributions of the parasite Trypanosoma cruzi and its vector Dipetalogaster maxima highlight areas at risk of Chagas disease transmission in Baja California Sur, Mexico, under climate change.

Dipetalogaster maxima is a primary vector of Chagas disease in the Cape region of Baja California Sur, Mexico. The geographic distribution of D. maxima is limited to this small region of the Baja California Peninsula in Mexico. Our study aimed to construct the ecological niche models (ENMs) of this understudied vector species and the parasite responsible for Chagas disease (Trypanosoma cruzi). We modelled the ecological niches of both species under current and future climate change projections in 2050 using four Representative Concentration Pathways (RCPs): RCP 2.6, RCP 4.5, RCP 6.0, and RCP 8.5. We also assessed the human population at risk of exposure to D. maxima bites, the hypothesis of ecological niche equivalency and similarity between D. maxima and T. cruzi, and finally the abundance centroid hypothesis. The ENM predicted a higher overlap between both species in the Western and Southern coastal regions of the Baja California Peninsula. The climate change scenarios predicted a Northern shift in the ecological niche of both species. Our findings suggested that the highly tourist destination of Los Cabos is a high-risk zone for Chagas disease circulation. Overall, the study provides valuable data to vector surveillance and control programs.

The couple's tree of life: Promoting and protecting relational identity.

We present The Couple's Tree of Life (CTOL) as a new collective narrative methodology to strengthen couple relationships and prevent conflicts. The CTOL, based on the tree of life methodology (Ncube & Denborough, Tree of Life, mainstreaming psychosocial care and support: a manual for facilitators, REPSSI, 2007), aims to reinforce the identity and strengths of the couple. We explain the CTOL implementation process and illustrate it step by step with a group of 14 adult heterosexual Caucasian couples who belonged to Protestant churches in Madrid (Spain). As a way to assess its usefulness before applying the CTOL to other groups of couples, we conducted a pre-post evaluation using the Dyadic Adjustment Scale of Spanier(1976). We found an improvement in dyadic adjustment, quality, understanding of, and satisfaction with, the relationship. The results, though not generalizable at this stage, suggest that the CTOL could reinforce the couple's identity while maintaining individual identities. We also discuss the possible applications of couples therapy.

Presentamos El árbol de la vida de la pareja (CTOL, por sus siglas en inglés) como una nueva metodología narrativa colectiva, con el fin de fortalecer las relaciones de pareja y para la prevención de conflictos. El CTOL, basado en la metodología del árbol de la vida (Ncube & Denborough, Tree of Life, mainstreaming psychosocial care and support: a manual for facilitators, REPSSI, 2007), tiene como finalidad reforzar la identidad y las fortalezas de la pareja. Explicamos el proceso de implementación del CTOL y lo ejemplificamos paso a paso con un grupo de 14 parejas heterosexuales caucásicas adultas que pertenecían a iglesias protestantes en Madrid (España). Como forma de evaluar su utilidad antes de aplicar el CTOL a otros grupos de parejas, realizamos una evaluación previa y posterior utilizando la Escala de Ajuste Diádico de Spanier (1976). Hallamos una mejora en el ajuste diádico, en la calidad, en la comprensión de la relación y en la satisfacción con esta. Los resultados, aunque no son generalizables en esta etapa, sugieren que el árbol de la vida de la pareja podría reforzar la identidad de la pareja y a la vez mantener las identidades individuales. También explicamos las posibles aplicaciones a la terapia de pareja.

Usefulness of IL-21, IL-7, and IL-15 conditioned media for expansion of antigen-specific CD8+ T cells from healthy donor-PBMCs suitable for immunotherapy.

Clonal anergy and depletion of antigen-specific CD8+ T cells are characteristics of immunosuppressed patients such as cancer and post-transplant patients. This has promoted translational research on the adoptive transfer of T cells to restore the antigen-specific cellular immunity in these patients. In the present work, we compared the capability of PBMCs and two types of mature monocyte-derived DCs (moDCs) to prime and to expand ex-vivo antigen-specific CD8+ T cells using culture conditioned media supplemented with IL-7, IL-15, and IL-21. The data obtained suggest that protocols involving moDCs are as efficient as PBMCs-based cultures in expanding antigen-specific CD8+ T cell to ELA and CMV model epitopes. These three gamma common chain cytokines promote the expansion of naïve-like and central memory CD8+ T cells in PBMCs-based cultures and the expansion of effector memory T cells when moDCs were used. Our results provide new insights into the use of media supplemented with IL-7, IL-15, and IL-21 for the in-vitro expansion of early-differentiated antigen-specific CD8+ T cells for immunotherapy purposes.

Understanding the Origin of Enhanced Piezoelectric Response in PVDF Matrices with Embedded ZnO Nanoparticles, from Polarizable Molecular Dynamics Simulations.

The pervasive use of portable electronic devices, powered from rechargeable batteries, represents a significant portion of the electricity consumption in the world. A sustainable and alternative energy source for these devices would require unconventional power sources, such as harvesting kinetic/potential energy from mechanical vibrations, ultrasound waves, and biomechanical motion, to name a few. Piezoelectric materials transform mechanical deformation into electric fields or, conversely, external electric fields into mechanical motion. Therefore, accurate prediction of elastic and piezoelectric properties of materials, from the atomic structure and composition, is essential for studying and optimizing new piezogenerators. Here, we demonstrate the application of harmonic-covalent and reactive force fields (FF), Dreiding and ReaxFF, respectively, coupled to the polarizable charge equilibration (PQEq) model for predicting the elastic moduli and piezoelectric response of crystalline zinc oxide (ZnO) and polyvinylidene difluoride (PVDF). Furthermore, we parametrized the ReaxFF atomic interactions for Zn-F in order to characterize the interfacial effects in hybrid PVDF matrices with embedded ZnO nanoparticles (NPs). We capture the nonlinear piezoelectric behavior of the PVDF-ZnO system at different ZnO concentrations and the enhanced response that was recently observed experimentally, between 5 and 7 wt % ZnO concentrations. From our simulation results, we demonstrate that the origin of this enhancement is due to an increase in the total atomic stress distribution at the interface between the two materials. This result provides valuable insight into the design of new and improved piezoelectric nanogenerators and demonstrates the practical value of these first-principles based modeling methods in materials science.

Non-Small-Cell Lung Cancer After Mantle Radiation: A Case Report and Brief Review.

Survivors of childhood and young adult cancer are at risk for developing subsequent malignant neoplasms, including lung cancer. As survival rates in this group continue to improve and patients enter later decades in life, determining the optimal surveillance and counseling strategies with regards to subsequent cancers remains a challenge. In this case report, we present a non-Hodgkin lymphoma survivor who was incidentally found to have non-small-cell lung cancer 30 years after undergoing treatment that included mantle radiation. We discuss the treatment-related risk factors for lung cancer in this population and potential implications for long-term follow-up.

Waveform-Dependent Electrosurgical Effects on Soft Hydrated Tissues.

Electrosurgical procedures are ubiquitously used in surgery. The commonly used power modes, including the coagulation and blend modes, utilize nonsinusoidal or modulated current waveforms. For the same power setting, the coagulation, blend, and pure cutting modes have different heating and thermal damage outcomes due to the frequency dependence of electrical conductivity of soft hydrated tissues. In this paper, we propose a multiphysics model of soft tissues to account for the effects of multifrequency electrosurgical power modes within the framework of a continuum thermomechanical model based on mixture theory. Electrical and frequency spectrum results from different power modes at low- and high-power settings are presented. Model predictions are compared with in vivo electrosurgical heating experiments on porcine liver tissue. The accuracy of the model in predicting experimentally observed temperature profiles is found to be overall greater when frequency-dependence is included. An Arrhenius type model indicates that more tissue damage is correlated with larger duty cycles in multifrequency modes.

Monitoring the responsiveness of T and antigen presenting cell compartments in breast cancer patients is useful to predict clinical tumor response to neoadjuvant chemotherapy.

BACKGROUND: Vaccination of mice with tumors treated with Doxorubicin promotes a T cell immunity that relies on dendritic cell (DC) activation and is responsible for tumor control in vaccinated animals. Despite Doxorubicin in combination with Cyclophosphamide (A/C) is widely used to treat breast cancer patients, the stimulating effect of A/C on T and APC compartments and its correlation with patient's clinical response remains to be proved. METHODS: In this prospective study, we designed an in vitro system to monitor various immunological readouts in PBMCs obtained from a total of 17 breast cancer patients before, and after neoadjuvant anti-tumor therapy with A/C. RESULTS: The results show that before treatment, T cells and DCs, exhibit a marked unresponsiveness to in vitro stimulus: whereas T cells exhibit poor TCR internalization and limited expression of CD154 in response to anti-CD3/CD28/CD2 stimulation, DCs secrete low levels of IL-12p70 and limited CD83 expression in response to pro-inflammatory cytokines. Notably, after treatment the responsiveness of T and APC compartments was recovered, and furthermore, this recovery correlated with patients' residual cancer burden stage. CONCLUSIONS: Our results let us to argue that the model used here to monitor the T and APC compartments is suitable to survey the recovery of immune surveillance and to predict tumor response during A/C chemotherapy.

FUSE certification enhances performance on a virtual computer based simulator for dispersive electrode placement.

BACKGROUND: The Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) has developed the fundamental use of surgical energy (FUSE) didactic curriculum in order to further understanding of the safe use of surgical energy. The virtual electrosurgical skill trainer (VEST) is being developed as a complementary simulation-based curriculum, with several modules already existing. Subsequently, a new VEST module has been developed about dispersive electrode placement. The purpose of this study is to assess knowledge about dispersive electrode placement in surgeons and surgical trainees in addition to describing a new VEST module. METHODS: Forty-six subjects (n = 46) were recruited for participation at the 2016 SAGES conference Learning Center. Subjects were asked to complete demographic surveys, a five-question pre-test, and a five-question post-test after completing the VEST dispersive electrode module. Subjects were then asked to rate different aspects of the module using a five-point Likert scale questionnaire. RESULTS: Mean pre-simulator and post-simulator assessment scores were 1.5 and 3.4, respectively, with Wilcoxon signed rank analysis showing a significant difference in the means (p < 0.05). Subjects were grouped by the presence (n = 12) or absence (n = 31) of prior FUSE experience and by training level. Mann-Whitney U testing showed no significant difference in pre-simulator assessment scores between attending surgeons and trainees (p > 0.05). In those with and without FUSE exposure, a significant difference (p < 0.05) was seen in pre-simulator assessment scores, and no significant difference in Likert scale assessment scores was seen. CONCLUSIONS: This study demonstrated a new VEST educational module. Consistently high Likert assessment scores showed that users felt that the VEST module helped their understanding of dispersive electrode placement. Additionally, the study reflected a potential knowledge deficit in the safe use of dispersive electrodes in the surgical community, also demonstrating that even some exposure to the FUSE curriculum developed by SAGES provides increased awareness about dispersive electrode use.

A continuum thermomechanical model of in vivo electrosurgical heating of hydrated soft biological tissues.

Radio-frequency (RF) heating of soft biological tissues during electrosurgical procedures is a fast process that involves phase change through evaporation and transport of intra- and extra-cellular water, and where variations in physical properties with temperature and water content play significant role. Accurately predicting and capturing these effects would improve the modeling of temperature change in the tissue allowing the development of improved instrument design and better understanding of tissue damage and necrosis. Previous models based on the Pennes' bioheat model neglect both evaporation and transport or consider evaporation through numerical correlations, however, do not account for changes in physical properties due to mass transport or phase change, nor capture the pressure increase due to evaporation within the tissue. While a porous media approach can capture the effects of evaporation, transport, pressure and changes in physical properties, the model assumes free diffusion of liquid and gas without a careful examination of assumptions on transport parameters in intact tissue resulting in significant under prediction of temperature. These different approaches have therefore been associated with errors in temperature prediction exceeding 20% when compared to experiments due to inaccuracies in capturing the effects of evaporation losses and transport. Here, we present a model of RF heating of hydrated soft tissue based on mixture theory where the multiphase nature of tissue is captured within a continuum thermomechanics framework, simultaneously considering the transport, deformation and phase change losses due to evaporation that occur during electrosurgical heating. The model predictions are validated against data obtained for in vivo ablation of porcine liver tissue at various power settings of the electrosurgical unit. The model is able to match the mean experimental temperature data with sharp gradients in the vicinity of the electrode during rapid low and high power ablation procedures with errors less than 7.9%. Additionally, the model is able to capture fast vaporization losses and the corresponding increase in pressure due to vapor buildup which have a significant effect on temperature prediction beyond 100 °C.

Elucidating the Methylammonium (MA) Conformation in MAPbBr3 Perovskite with Application in Solar Cells.

Hybrid organic-inorganic perovskites, MAPbX3 (X = halogen), containing methylammonium (MA: CH3-NH3+) in the large voids conformed by the PbX6 octahedral network, are the active absorption materials in the new generation of solar cells. CH3NH3PbBr3 is a promising member with a large band gap that gives rise to a high open circuit voltage. A deep knowledge of the crystal structure and, in particular, the MA conformation inside the perovskite cage across the phase transitions undergone below room temperature, seems essential to establish structure-property correlations that may drive to further improvements. The presence of protons requires the use of neutrons, combined with synchrotron XRD data that help to depict subtle symmetry changes undergone upon cooling. We present a consistent picture of the structural features of this fascinating material, in complement with photocurrent measurements from a photodetector device, demonstrating the potential of MAPbBr3 in optoelectronics.

Single nanoparticle detection for multiplexed protein diagnostics with attomolar sensitivity in serum and unprocessed whole blood.

Although biomarkers exist for a range of disease diagnostics, a single low-cost platform exhibiting the required sensitivity, a large dynamic-range and multiplexing capability, and zero sample preparation remains in high demand for a variety of clinical applications. The Interferometric Reflectance Imaging Sensor (IRIS) was utilized to digitally detect and size single gold nanoparticles to identify protein biomarkers in unprocessed serum and blood samples. IRIS is a simple, inexpensive, multiplexed, high-throughput, and label-free optical biosensor that was originally used to quantify biomass captured on a surface with moderate sensitivity. Here we demonstrate detection of ß-lactoglobulin, a cow's milk whey protein spiked in serum (>10 orders of magnitude) and whole blood (>5 orders of magnitude), at attomolar sensitivity. The clinical utility of IRIS was demonstrated by detecting allergen-specific IgE from microliters of characterized human serum and unprocessed whole blood samples by using secondary antibodies against human IgE labeled with 40 nm gold nanoparticles. To the best of our knowledge, this level of sensitivity over a large dynamic range has not been previously demonstrated. IRIS offers four main advantages compared to existing technologies: it (i) detects proteins from attomolar to nanomolar concentrations in unprocessed biological samples, (ii) unambiguously discriminates nanoparticles tags on a robust and physically large sensor area, (iii) detects protein targets with conjugated very small nanoparticle tags (~40 nm diameter), which minimally affect assay kinetics compared to conventional microparticle tagging methods, and (iv) utilizes components that make the instrument inexpensive, robust, and portable. These features make IRIS an ideal candidate for clinical and diagnostic applications.

Genetic diversity and population genetics of mosquitoes (Diptera: Culicidae: Culex spp.) from the Sonoran Desert of North America.

The population genetics and phylogenetic relationships of Culex mosquitoes inhabiting the Sonoran Desert region of North America were studied using mitochondrial DNA and microsatellite molecular markers. Phylogenetic analyses of mitochondrial cytochrome c oxidase subunit I (COI) from mosquitoes collected over a wide geographic area, including the Baja California peninsula, and mainland localities in southern Arizona, USA and Sonora, Mexico, showed several well-supported partitions corresponding to Cx. quinquefasciatus, Cx. tarsalis, and two unidentified species, Culex sp. 1 and sp. 2. Culex quinquefasciatus was found at all localities and was the most abundant species collected. Culex tarsalis was collected only at Tucson, Arizona and Guaymas, Sonora. The two unidentified species of Culex were most abundant at Navojoa in southern Sonora. Haplotype and nucleotide diversities in the COI gene segment were substantially lower in Cx. quinquefasciatus compared with the other three species. Analysis of molecular variance revealed little structure among seven populations of Cx. quinquefasciatus, whereas significant structure was found between the two populations of Cx. tarsalis. Evidence for an historical population expansion beginning in the Pleistocene was found for Cx. tarsalis. Possible explanations for the large differences in genetic diversity between Cx. quinquefasciatus and the other species of Culex are presented.

MRD-directed therapy in CLL: ready for prime time?

In recent years, the treatment paradigm for patients with chronic lymphocytic leukemia (CLL) has moved away from chemoimmunotherapy (CIT) toward the use of novel targeted agents. Commercially available drugs, including Bruton's tyrosine kinase inhibitors and the BCL2 inhibitor venetoclax, often used in combination with anti-CD20 monoclonal antibodies, are now the mainstay of therapy both in the frontline and in relapsed settings. As the landscape for CLL management evolves, therapeutic endpoints need to be redefined. Detection of measurable residual disease (MRD) is a sensitive tool to identify disease burden following treatment with several therapeutic regimens in CLL (including CIT, venetoclax-based regimens, and cellular therapies), and it has demonstrated prognostic value. Despite recent advances, the utility of MRD-directed therapy and attempts to eradicate it in routine clinical practice remain debated. There is little comparative data from clinical trials on the best assay to determine undetectable MRD (U-MRD) and whether its monitoring can lead to changes in treatment strategies. Our review discusses the definitions of MRD, assays for its detection, and its impact on long-term survival outcomes for patients with a CLL diagnosis.

Phylogenetic description of Trypanosoma cruzi isolates from Dipetalogaster maxima: Occurrence of TcI, TcIV, and TcIV-USA.

Trypanosoma cruzi is the parasite responsible for Chagas disease. The parasite has been classified into six taxonomic assemblages: TcI-TcVI and TcBat (aka Discrete Typing Units or Near-Clades). No studies have focused on describing the genetic diversity of T. cruzi in the northwestern region of Mexico. Within the Baja California peninsula lives Dipetalogaster maxima, the largest vector species for CD. The study aimed to describe the genetic diversity of T. cruzi within D. maxima. A total of three Discrete Typing Units (DTUs) were found (TcI, TcIV, and TcIV-USA). TcI was the predominant DTU found (∼75% of samples), in concordance with studies from the southern USA, one sample was described as TcIV while the other ∼20% pertained to TcIV-USA, which has recently been proposed to have enough genetic divergence from TcIV, to merit its own DTU. Potential phenotype differences between TcIV and TcIV-USA should be assessed in future studies.

Structural Features and Optical Properties of All-Inorganic Zero-Dimensional Halides Cs4PbBr6-xIx Obtained by Mechanochemistry.

Despite the great success of hybrid CH3NH3PbI3 perovskite in photovoltaics, ascribed to its excellent optical absorption properties, its instability toward moisture is still an insurmountable drawback. All-inorganic perovskites are much less sensitive to humidity and have potential interest for solar cell applications. Alternative strategies have been developed to design novel materials with appealing properties, which include different topologies for the octahedral arrangements from three-dimensional (3D, e.g., CsPbBr3 perovskite) or two-dimensional (2D, e.g., CsPb2Br5) to zero-dimensional (0D, i.e., without connection between octahedra), as the case of Cs4PbX6 (X = Br, I) halides. The crystal structure of these materials is complex, and their thermal evolution is unexplored. In this work, we describe the synthesis of Cs4PbBr6-xIx (x = 0, 2, 4, 6) halides by mechanochemical procedures with green credentials; these specimens display excellent crystallinity enabling a detailed structural investigation from synchrotron X-ray powder diffraction (SXRD) data, essential to revisit some features in the temperature range of 90-298 K. In all this regime, the structure is defined in the trigonal R3̅c space group (#167). The presence of Cs and X vacancies suggests some ionic mobility into the crystal structure of these 0D halides. Bond valence maps (BVMs) are useful in determining isovalent surfaces for both Cs4PbBr6 and Cs4PbI6 phases, unveiling the likely ionic pathways for cesium and bromide ions and showing a full 3D connection in the bromide phase, in contrast to the iodide one. On the other hand, the evolution of the anisotropic displacement parameters is useful to evaluate the Debye temperatures, confirming that Cs atoms have more freedom to move, while Pb is more confined at its site, likely due to a higher covalency degree in Pb-X bonds than that in Cs-X bonds. Diffuse reflectance ultraviolet-visible (UV-vis) spectroscopy shows that the optical band gap can be tuned depending on iodine content (x) in the range of 3.6-3.06 eV. From density functional theory (DFT) simulations, the general trend of reducing the band gap when Br is replaced by I is well reproduced.

Haemophagocytic lymphohistiocytosis following COVID-19 mRNA vaccination.

The development of vaccinations has been instrumental in the ongoing effort to combat the COVID-19 pandemic. Although the benefits of vaccination are unquestionable, there have been reports of potentially rare life-threatening complications following vaccination including thrombocytopaenia, haemolytic anaemia, vasculitis and myocarditis. Haemophagocytic lymphohistiocytosis (HLH), a rare but life-threatening inflammatory condition, has also been described postadenoviral vector COVID-19 vaccination but it has never been reported post-messenger RNA (mRNA) COVID-19 vaccination. We report two cases of HLH admitted to our hospital after administration of COVID-19 mRNA vaccines. We also searched the vaccine adverse event reporting system and found 50 reports of suspected HLH following COVID-19 vaccination. Presently, we cannot define a causality between COVID-19 mRNA vaccination and HLH development. However, we hope the reporting of our two cases (and additional cases seen in the adverse event reporting database) will help us determine whether there is a potential relationship. Prompt recognition of this condition is of utmost importance to initiate life-saving therapy.

Crystal structure thermal evolution and novel orthorhombic phase of methylammonium lead bromide, CH3NH3PbBr3.

Methylammonium (MA) lead trihalide perovskites, CH3NH3PbX3 (X = I, Br, Cl), have emerged as a new class of light-absorbing materials for photovoltaic applications, reaching efficiencies of 23% when implemented in solar cell heterojunctions. In particular, MAPbBr3 is a promising member with a large bandgap that gives rise to a high open circuit voltage. Here we present a structural study from neutron diffraction (ND) data of an undeuterated MAPbBr3 specimen, carried out to follow its crystallographic behaviour in the 2-298 K temperature range. Besides the known crystallographic phases, i.e. the high-temperature Pm[Formula: see text]m cubic structure, the intermediate I4/mcm tetragonal symmetry and the low-temperature Pnma orthorhombic phase, we additionally identified, from a detailed sequential ND analysis, a novel intermediate phase within the 148.5-154.0 K temperature range as an orthorhombic Imma structure, early associated with a coexistence of phases. Moreover, our ND data allowed us to unveil the configuration of the organic MA units and their complete localization within the mentioned temperature range, thus improving the crystallographic description of this compound. The evolution with temperature of the H-bonds between the organic molecule and the inorganic cage is also followed. A deep knowledge of the crystal structure and, in particular, the MA conformation inside the perovskite cage seems essential to establish structure-property correlations that may drive further improvements.

Phylogenetic diversity of two common Trypanosoma cruzi lineages in the Southwestern United States.

Trypanosoma cruzi is the causative agent of Chagas disease, a devastating parasitic disease endemic to Central and South America, Mexico, and the USA. We characterized the genetic diversity of Trypanosoma cruzi circulating in five triatomine species (Triatoma gerstaeckeri, T. lecticularia, T.indictiva, T. sanguisuga and T. recurva) collected in Texas and Southern Arizona using multilocus sequence typing (MLST) with four single-copy loci (cytochrome oxidase subunit II- NADH dehydrogensase subunit 1 region (COII-ND1), mismatch-repair class 2 (MSH2), dihydrofolate reductase-thymidylate synthase (DHFR-TS) and a nuclear gene with ID TcCLB.506529.310). All T. cruzi variants fall in two main genetic lineages: 75% of the samples corresponded to T. cruzi Discrete Typing Unit (DTU) I (TcI), and 25% to a North American specific lineage previously labelled TcIV-USA. Phylogenetic and sequence divergence analyses of our new data plus all previously published sequence data from those four loci collected in the USA, show that TcIV-USA is significantly different from any other previously defined T. cruzi DTUs. The significant level of genetic divergence between TcIV-USA and other T. cruzi DTUs should lead to an increased focus on understanding the epidemiological importance of this DTU, as well as its geographical range and pathogenicity in humans and domestic animals. Our findings further corroborate the fact that there is a high genetic diversity of the parasite in North America and emphasize the need for appropriate surveillance and vector control programs for Chagas disease in southern USA and Mexico.