Recent progress in the assembly of nanodevices and van der Waals heterostructures by deterministic placement of 2D materials.

Designer heterostructures can now be assembled layer-by-layer with unmatched precision thanks to the recently developed deterministic placement methods to transfer two-dimensional (2D) materials. This possibility constitutes the birth of a very active research field on the so-called van der Waals heterostructures. Moreover, these deterministic placement methods also open the door to fabricate complex devices, which would be otherwise very difficult to achieve by conventional bottom-up nanofabrication approaches, and to fabricate fully-encapsulated devices with exquisite electronic properties. The integration of 2D materials with existing technologies such as photonic and superconducting waveguides and fiber optics is another exciting possibility. Here, we review the state-of-the-art of the deterministic placement methods, describing and comparing the different alternative methods available in the literature, and we illustrate their potential to fabricate van der Waals heterostructures, to integrate 2D materials into complex devices and to fabricate artificial bilayer structures where the layers present a user-defined rotational twisting angle.

Characterization of highly crystalline lead iodide nanosheets prepared by room-temperature solution processing.

Two-dimensional (2D) semiconducting materials are particularly appealing for many applications. Although theory predicts a large number of 2D materials, experimentally only a few of these materials have been identified and characterized comprehensively in the ultrathin limit. Lead iodide, which belongs to the transition metal halides family and has a direct bandgap in the visible spectrum, has been known for a long time and has been well characterized in its bulk form. Nevertheless, studies of this material in the nanometer thickness regime are rather scarce. In this article we demonstrate an easy way to synthesize ultrathin, highly crystalline flakes of PbI2 by precipitation from a solution in water. We thoroughly characterize the produced thin flakes with different techniques ranging from optical and Raman spectroscopy to temperature-dependent photoluminescence and electron microscopy. We compare the results to ab initio calculations of the band structure of the material. Finally, we fabricate photodetectors based on PbI2 and study their optoelectronic properties.

A Ketone Monoester with Carbohydrate Improves Cognitive Measures Postexercise, but Not Performance in Trained Females.

PURPOSE: The acute ingestion of a ketone monoester with the coingestion of a carbohydrate (KME + CHO) compared with carbohydrate (CHO) was investigated on cycling performance and cognitive performance in trained females. METHODS: Using a two condition, placebo-controlled, double-blinded and crossover design, 12 trained females (mean ± SD: age, 23 ± 3 yr; height, 1.64 ± 0.08 m; mass, 65.2 ± 12.7 kg) completed a baseline assessment of cognitive performance (psychomotor vigilance testing (PVT), task switching, and incongruent flanker), followed by 6 × 5-min intervals at 40%, 45%, 50%, 55%, 60%, and 65% of their maximal power output (W max ) and then a 10-km time trial, concluding with the same assessments of cognitive performance. Participants consumed either 375 mg·kg -1 body mass of KME with a 6% CHO solution (1 g·min -1 of exercise) or CHO alone, across three boluses (50:25:25). RESULTS: Blood ß-hydroxybutyrate concentrations averaged 1.80 ± 0.07 and 0.13 ± 0.01 mM during exercise in KME + CHO and CHO, respectively. Blood glucose decreased after drink 1 of KME + CHO (~15%; P = 0.01) but not CHO, and lactate concentrations were lower in KME + CHO at 50%, 55%, 60%, and 65% W max (all P < 0.05) compared with CHO. Despite these changes, no differences were found between conditions for time trial finishing times (KME + CHO, 29.7 ± 5.7 min; CHO, 29.6 ± 5.7 min; P = 0.92). However, only KME + CHO resulted in increases in psychomotor vigilance testing speed (~4%; P = 0.01) and faster reaction times (~14%; P < 0.01), speed (~15%; P < 0.01), and correct responses (~13%; P = 0.03) in the incongruent flanker during posttesting compared with CHO. CONCLUSIONS: The acute ingestion of a KME + CHO elevated blood ß-hydroxybutyrate and lowered glucose and lactate across multiple time points during exercise compared with CHO. Although these changes did not affect physical performance, several markers of cognitive performance were improved by the addition of a KME in trained females.

The Investigation of the Influence of a Cu2O Buffer Layer on Hole Transport Layers in MAPbI3-Based Perovskite Solar Cells.

The passivation engineering of the hole transport layer in perovskite solar cells (PSCs) has significantly decreased carrier accumulation and open circuit voltage (Voc) loss, as well as energy band mismatching, thus achieving the goal of high-power conversion efficiency. However, most devices incorporating organic/inorganic buffer layers suffer from poor stability and low efficiency. In this article, we have proposed an inorganic buffer layer of Cu2O, which has achieved high efficiency on lower work function metals and various frequently used hole transport layers (HTLs). Once the Cu2O buffer layer was applied to modify the Cu/PTAA interface, the device exhibited a high Voc of 1.20 V, a high FF of 75.92%, and an enhanced PCE of 22.49% versus a Voc of 1.12 V, FF of 69.16%, and PCE of 18.99% from the (PTAA/Cu) n-i-p structure. Our simulation showed that the application of a Cu2O buffer layer improved the interfacial contact and energy alignment, promoting the carrier transportation and reducing the charge accumulation. Furthermore, we optimized the combinations of the thicknesses of the Cu2O, the absorber layer, and PTAA to obtain the best performance for Cu-based perovskite solar cells. Eventually, we explored the effect of the defect density between the HTL/absorber interface and the absorber/ETL interface on the device and recommended the appropriate reference defect density for experimental research. This work provides guidance for improving the experimental efficiency and reducing the cost of perovskite solar cells.

Spin-to-orbital angular momentum conversion in focusing, scattering, and imaging systems.

We present a general theory of spin-to-orbital angular momentum (AM) conversion of light in focusing, scattering, and imaging optical systems. Our theory employs universal geometric transformations of non-paraxial optical fields in such systems and allows for direct calculation and comparison of the AM conversion efficiency in different physical settings. Observations of the AM conversions using local intensity distributions and far-field polarimetric measurements are discussed.

Far-field polarization-based sensitivity to sub-resolution displacements of a sub-resolution scatterer in tightly focused fields.

We present a system built to perform measurements of scattering-angle-resolved polarization state distributions across the exit pupil of a high numerical aperture collector lens. These distributions contain information about the three-dimensional electromagnetic field that results from the interaction of a tightly focused field and a sub-resolution scatterer. Experimental evidence proving that the system allows for high polarization-dependent sensitivity to sub-resolution displacements of a sub-resolution scatterer is provided together with the corresponding numerical results.

Optical nanoprobing via spin-orbit interaction of light.

We show, both theoretically and experimentally, that high-numerical-aperture (NA) optical microscopy is accompanied by strong spin-orbit interaction of light, which translates fine information about the specimen to the polarization degrees of freedom of light. An 80 nm gold nanoparticle scattering the light in the focus of a high-NA objective generates angular momentum conversion, which is seen as a nonuniform polarization distribution at the exit pupil. We demonstrate remarkable sensitivity of the effect to the position of the nanoparticle: Its subwavelength displacement produces the giant spin-Hall effect, i.e., macroseparation of spins in the outgoing light. This brings forth a far-field optical nanoprobing technique based on the spin-orbit interaction of light.

Tunable Photodetectors via In Situ Thermal Conversion of TiS3 to TiO2.

In two-dimensional materials research, oxidation is usually considered as a common source for the degradation of electronic and optoelectronic devices or even device failure. However, in some cases a controlled oxidation can open the possibility to widely tune the band structure of 2D materials. In particular, we demonstrate the controlled oxidation of titanium trisulfide (TiS3), a layered semicon-ductor that has attracted much attention recently thanks to its quasi-1D electronic and optoelectron-ic properties and its direct bandgap of 1.1 eV. Heating TiS3 in air above 300 °C gradually converts it into TiO2, a semiconductor with a wide bandgap of 3.2 eV with applications in photo-electrochemistry and catalysis. In this work, we investigate the controlled thermal oxidation of indi-vidual TiS3 nanoribbons and its influence on the optoelectronic properties of TiS3-based photodetec-tors. We observe a step-wise change in the cut-off wavelength from its pristine value ~1000 nm to 450 nm after subjecting the TiS3 devices to subsequent thermal treatment cycles. Ab-initio and many-body calculations confirm an increase in the bandgap of titanium oxysulfide (TiO2-xSx) when in-creasing the amount of oxygen and reducing the amount of sulfur.

Anti-nucleosome antibodies increase the risk of renal relapse in a prospective cohort of patients with clinically inactive systemic lupus erythematosus.

An important goal in the management of systemic lupus erythematosus (SLE) is the prediction of relapses. This study assesses whether anti-nucleosome antibodies (anti-NCS) increase the risk of renal relapse in inactive SLE. A prospective cohort of 115 patients with inactive SLE (M-SLEDAI ≤ 2) were followed for 12 months to assess the development of relapse (increase of M-SLEDAI ≥ 4) and specific renal flare (renal SLEDAI ≥ 4). At baseline, we identified potential risk factors for relapse, including anti-NCS. At baseline, 18 (16%) of the 115 patients with inactive SLE were anti-NCS positive. At the 12-month follow-up, anti-NCS-positive patients had a higher incidence of renal relapse compared to anti-NCS-negative patients (38.9% vs 13.4%, respectively). In Cox regression analysis, after adjusting for age, disease duration, anti-dsDNA, and immunosuppressive drugs, the presence of anti-NCS positivity at baseline increased the risk of renal relapse (HR: 5.31, 95% CI 2.03-13.92). Nevertheless, there were no differences in the incidence of other relapses in anti-NCS-positive versus anti-NCS-negative. Our results indicate that in inactive SLE, anti-NCS determination can be useful for identifying patients with a higher risk of developing renal relapse. Interestingly, this study identified that continued use of oral immunosuppressive therapy in patients with inactive SLE can reduce the risk of renal relapse.

Stokes polarimeter optimization in the presence of shot and Gaussian noise.

An error minimization method is presented for Stokes polarimeters applicable when the detected signals are affected by a combination of shot and Gaussian noise. The expectation of the Stokes vector variance is used as a performance measure. This measure is compared with the condition number of a polarization state analyzer matrix that is commonly used as a figure of merit. We show that a polarimeter with the minimum condition number is not necessarily optimal. The approach is used to optimize existing prism based polarimeters giving improvements in the performance when shot-noise cannot be neglected.

Thickness-Dependent Differential Reflectance Spectra of Monolayer and Few-Layer MoS2, MoSe2, WS2 and WSe2.

The research field of two dimensional (2D) materials strongly relies on optical microscopy characterization tools to identify atomically thin materials and to determine their number of layers. Moreover, optical microscopy-based techniques opened the door to study the optical properties of these nanomaterials. We presented a comprehensive study of the differential reflectance spectra of 2D semiconducting transition metal dichalcogenides (TMDCs), MoS2, MoSe2, WS2, and WSe2, with thickness ranging from one layer up to six layers. We analyzed the thickness-dependent energy of the different excitonic features, indicating the change in the band structure of the different TMDC materials with the number of layers. Our work provided a route to employ differential reflectance spectroscopy for determining the number of layers of MoS2, MoSe2, WS2, and WSe2.

Serum levels of P-glycoprotein and persistence of disease activity despite treatment in patients with systemic lupus erythematosus.

Around 25% of patients with systemic lupus erythematosus (SLE) could be refractory to conventional therapies. P-glycoprotein expression on cell surface has been implied on drug resistance, however, to date, it is unknown if P-gp serum levels are associated with SLE disease activity. Evaluate the association of serum P-gp levels and SLE with disease activity despite treatment. A cross-sectional study was conducted on 93 female SLE patients, all receiving glucocorticoids at stable doses for the previous 6 months before to baseline. SLE patients were classified into two groups: (a) patients with active disease [SLE disease activity index (SLEDAI) ≥ 3] despite treatment, and (b) patients with inactive disease (SLEDAI < 3) after treatment. Forty-three healthy females comprised the control group. Serum P-gp, anti-DNA, and both anti-nucleosome antibody levels were measured using ELISA. Active-SLE patients despite treatment had higher P-gp levels compared with inactive-SLE after treatment (78.02 ng/mL ± 114.11 vs. 33.75 ng/mL ± 41.11; p = 0.018) or versus reference group subjects (30.56 ng/mL ± 28.92; p = 0.011). P-gp levels correlated with the scores of SLEDAI (r = 0.26; p = 0.01), Mexican-SLEDAI (MEX-SLEDAI) (r = 0.32; p = 0.002), SLICC/ACR damage index (r = 0.47; p < 0.001), and with prednisone doses (r = 0.33; p = 0.001). In the multivariate model, the high P-gp levels were associated with SLICC/ACR score (p = 0.001), and SLEDAI score (p = 0.014). Our findings support a relationship between serum P-gp levels and SLE with disease activity despite treatment, but it requires further validation in longitudinal studies.

Optical contrast and refractive index of natural van der Waals heterostructure nanosheets of franckeite.

We study mechanically exfoliated nanosheets of franckeite by quantitative optical microscopy. The analysis of transmission-mode and epi-illumination-mode optical microscopy images provides a rapid method to estimate the thickness of the exfoliated flakes at first glance. A quantitative analysis of the optical contrast spectra by means of micro-reflectance allows one to determine the refractive index of franckeite over a broad range of the visible spectrum through a fit of the acquired spectra to a model based on the Fresnel law.

Utility of soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) as biomarker to predict therapeutic response to methotrexate in rheumatoid arthritis.

The objective of this study was to investigate the usefulness of soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) in predicting short-term therapeutic response to methotrexate (MTX) in rheumatoid arthritis (RA). Patients with active RA, with Disease Activity Score-28 joints (DAS-28) >3.2, starting oral MTX, were included. We measured at baseline, 3 and 6 mo: DAS-28, Health Assessment Questionnaire-Disability Index (HAQ-DI), patient's perception of disease severity, morning stiffness and pain, as well as modifications in sTREM-1 levels. A reduction in DAS-28 > 1.2 at 3 or 6 mo was considered adequate response. A significant decrease in DAS-28 was observed at 3 and 6 mo. HAQ-DI also decreased at 3 and 6 mo. No significant changes were observed in sTREM-1 levels at 3 or 6 mo. Using as cut-off a baseline value of sTREM-1 levels > 390 pg/ml, we obtained low values of sensitivity (61.5%), specificity (59.3%), positive predictive value (59.3%) and negative predictive value (61.5%) for adequate response to MTX at 3 mo. We found no clinical value of sTREM-1 levels in predicting therapeutic response to MTX in RA. Further studies should evaluate if sTREM-1 levels are predictive for other outcomes, including higher structural damage or good response to biologics.

Serum levels of adiponectin and leptin as biomarkers of proteinuria in lupus nephritis.

INTRODUCTION: There are controversial results about the role of serum leptin and adiponectin levels as biomarkers of the severity of proteinuria in lupus nephritis. OBJECTIVE: The aim of this study was to evaluate the relationship between serum leptin and adiponectin levels with severity of proteinuria secondary to lupus nephritis (LN). METHODS: In a cross-sectional study, 103 women with systemic lupus erythematosus (SLE) were evaluated for kidney involvement. We compared 30 SLE patients with LN, all of them with proteinuria, versus 73 SLE patients without renal involvement (no LN). A comprehensive set of clinical and laboratory variables was assessed, including serum levels of leptin and adiponectin by ELISA. Multivariate analyses were used to adjust for potential confounders associated with proteinuria in LN. RESULTS: We found higher adiponectin levels in the LN group compared with the no LN group (20.4 ± 10.3 vs 15.6 ± 7.8 µg/mL; p = 0.02), whereas no differences were observed in leptin levels (33.3 ± 31.4 vs 22.5 ± 25.5 ng/mL; p = 0.07). Severity of proteinuria correlated with an increase in adiponectin levels (r = 0.31; p = 0.001), but no correlation was observed with leptin. Adiponectin levels were not related to anti-dsDNA or anti-nucleosome antibodies. In the logistic regression, adiponectin levels were associated with a high risk of proteinuria in SLE (OR = 1.06; 95% CI 1.01-1.12; p = 0.02). Instead, leptin was not associated with LN. CONCLUSION: These findings indicate that adiponectin levels are useful markers associated with proteinuria in LN. Further longitudinal studies are required to identify if these levels are predictive of renal relapse.

Association of adipokines, interleukin-6, and tumor necrosis factor-α concentrations with clinical characteristics and presence of spinal syndesmophytes in patients with ankylosing spondylitis: A cross-sectional study.

Objective To identify correlations of the serum leptin, adiponectin, interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) concentrations with the clinical characteristics, presence of spinal syndesmophytes, and body composition in patients with ankylosing spondylitis (AS). Methods Forty-eight patients with AS were compared with 41 sex- and age-matched controls. Assessment included clinical characteristics and the presence of spinal syndesmophytes. The serum leptin, adiponectin, TNF-α, and IL-6 concentrations were determined. Body composition was evaluated using dual-energy X-ray absorptiometry. Results Patients with AS and controls had similar fat mass and lean mass. Patients with AS had higher serum TNF-α and leptin concentrations than controls (52.3 vs. 1.5 pg/mL and 17.2 vs. 9.0 µg/mL, respectively). The IL-6 and adiponectin concentrations were not significantly different between the two groups. Patients with syndesmophytes had higher leptin concentrations than those without syndesmophytes (22.1 vs. 10.9 µg/mL); this difference remained after adjustment for the body mass index. Conclusion Elevated leptin concentrations are associated with spinal radiographic damage in patients with AS and can serve as a biomarker. Future studies should evaluate whether leptin might be a potential target for treatments to avoid structural damage.

Utilidad del apósito liofilizado de piel de cerdo en el manejo de cicatrización de úlcera de pie diabético / Usefulness of lyophilized pig skin dressings in wound healing as treatment for diabetic foot ulcer

Resumen Objetivo: Mostrar la utilidad del apósito liofilizado de piel de cerdo comparado con el manejo conservador con sulfadiazina de plata en el proceso de cicatrización de la úlcera de pie diabético. Materiales y Método: Estudio cuasiexperimental en pacientes con diagnóstico de pie diabético, se establecieron 2 grupos de estudio utilizando una relación 2:1, el grupo de exposición (10 pacientes) tratado con apósito liofilizado de piel de cerdo y el grupo de control (5 pacientes) manejado con sulfadiazina de plata. La utilidad se midió con la cicatrización en semanas de tratamiento. El análisis estadístico incluyó prueba de t, prueba de z, regresión logística simple y cálculo de la probabilidad del evento. Resultados: El tiempo de cicatrización fue más corto en el grupo manejado con apósito liofilizado de piel de cerdo (10,20 semanas) que en el grupo con manejo a base de sulfadiazina de plata (13,8 semanas). A las 9 semanas de iniciado el tratamiento, la mitad de las pacientes con apósito de piel de cerdo ya habían cicatrizado comparado con la cicatrización en el grupo manejado con sulfadiazina de plata (20%). La probabilidad de cicatrización a las 11 semanas en paciente manejados con sulfadiazina de plata es 20% y con apósito liofilizado de piel de cerdo 80%. Conclusión: El apósito liofilizado de piel de cerdo tuvo mejores resultados en el estudio, comparado con el manejo estándar con sulfadiazina de plata. Es necesario realizar un estudio aleatorizado para determinar la efectividad de este material como herramienta terapéutica.

Aim: To demonstrate the usefulness of lyophilized pig skin dressings versus usual management with silver sulfadiazine in wound healing treatment for diabetic foot ulcers. Materials and Method: In this quasi-experimental study, we included patients diagnosed with diabetic foot. We established two groups with a distribution (2:1), the exposure group treated with lyophilized pig skin dressings (10 patients) and the control group (5 patients), the standard of care with silver sulfadiazine. Usefulness was measured with wound healing in treatment weeks. Statistical analysis included t-test, z-test, simple logistic regression, and calculation of probability of an event. Results: Wound healing time was shorter in the group treated with lyophilized pig skin dressing (10.20 weeks) than in the group treated with silver sulfadiazine (13.8 weeks). At 9 weeks after treatment started, 50% of patients treated with lyophilized pig skin dressings had complete wound healing compared with the patients in the group managed with silver sulfadiazine. (20%). The probability of wound healing been completed at 11 weeks in a patient managed with silver sulfadiazine is 20%, compared to lyophilized pig skin dressings is 80%. Conclusion: Lyophilized pig skin dressings had better outcomes than silver sulfadiazine in wound healing treatment for diabetic foot ulcers inside the study. Is mandatory develop another study with a randomized design to determinate the effectiveness as a therapeutic alternative.

Comparación del estado nutricional, cronotipo y conducta alimentaria en estudiantes universitarios chilenos que presentan el polimorfismo rs3749474T/C o rs4864548A/G del gen CLOCK / Comparison of nutritional status, chronotype and eating behavior in Chilean university students presenting the polymorphism rs3749474T / C or rs4864548A / G of the CLOCK gene

FUNDAMENTOS: El estado nutricional puede verse afectado por la conducta alimentaria y los ritmos circadianos. Estos se encuentran regulados por el gen CLOCK, cuyos alelos T del SNP rs3749474T/C y A del SNP rs4864548A/G, han sido asociados con la obesidad en adultos. MÉTODOS: Se evaluó a 65 sujetos usando la técnica PCR en tiempo real para determinar si era portadores del alelo T del SNP rs3749474T/C o del A del SNP rs4864548A/G. Se realizaron mediciones antropométricas, y se aplicó los cuestionarios TFEQ y el Horne-Östberg. RESULTADOS: De los 65 sujetos estudiados, 8 eran portadores del alelo T del SNP rs3749474T/C y 7 del A del SNP rs4864548A/G. Los portadores del alelo A presentaron mayores valores promedio de IMC (26,58), circunferencia de cintura (89,57cm) y porcentaje de grasa (31,56%) no existiendo diferencias estadísticamente significativas entre ellos. No se encontraron diferencias estadísticamente significativas en cuanto a la conducta alimentaria. El 66,67% del total de los sujetos presentó un cronotipo de tipo intermedio. CONCLUSIONES: Los portadores del alelo A del SNP rs4864548A/G presentarían un mayor potencial de sufrir problemas asociados a la obesidad, pero es necesario realizar estudios con poblaciones más grandes y con mejor paridad de género, que permita corroborar esta aseveración

BACKGROUND: Nutritional status may be affected by eating behavior and circadian rhythms. These are regulated by the CLOCK gene, whose T alleles of SNP rs3749474T / C and A of SNP rs4864548A / G, have been associated with obesity in adults. METHODS: 65 subjects were evaluated using the real-time PCR technique to determine whether they were carriers of the T allele of the SNP rs3749474T/C or the A of the SNP rs4864548A/G. Anthropometric measurements were made, and the TFEQ and Horne-Östberg questionnaires were applied. RESULTS: Of the 65 subjects studied, 8 were carriers of the T allele of the SNP rs3749474T / C and 7 of the A of the SNP rs4864548A/G. The carriers of the A allele had higher average BMI values (26.58), waist circumference (89.57cm) and fat percentage (31.56%), with no statistically significant differences between them. No statistically significant differences were found regarding eating behavior. 66.67% of the total subjects presented an intermediate type chronotype. CONCLUSIONS: The carriers of the A allele of SNP rs4864548A/G would have a greater potential to suffer problems associated with obesity, but studies with larger populations and with better gender parity are necessary, which allows to confirm this assertion

[Prognostic factors associated with mortality in newborns with congenital diaphragmatic hernia]. / Factores pronósticos asociados a mortalidad en recién nacidos con hernia diafragmática congénita.

UNLABELLED: The objective was to identify prognostic factors associated with mortality in newborns with congenital diaphragmatic hernia. METHODS: Study design was cases and controls nested in a cohort. We studied 65 newborns. Variables analyzed included gestational age, birth weight, Apgar and Silverman scores, surgery timing, presence of pneumothorax, degree of pulmonary hypoplasia, persistent pulmonary hypertension, mean airway pressure, blood gas analysis, ventilatory indexes, and risk of death score at admission. RESULTS: Median gestational age was 38 weeks and median birth weight was 2,975 g. Lung hypoplasia ranged from 20-95%. Mortality was 40%; its main cause was persistent pulmonary hypertension. In multivariate analysis significant prognostic factors were risk of death > 50% (ORa = 59, 95% Confidence interval [CI] = 9.6-361) and mean airway pressure > 13 (ORa = 6, 95% CI = 1.2-29). CONCLUSIONS: Factors that influence prognosis of newborns with congenital diaphragmatic hernia are related with ventilation process as well as mortality risk score at admission to neonatal intensive care unit.

Etnomedicina en Los Altos de Chiapas, México / Ethnomedicine in The Highlands of Chiapas, Mexico

The objective of the this research was to register the current popular therapeutic use of medicinal plants in the Tzotzil indigenous population, in The Highlands of Chiapas, Mexico. The data were collected from 59 informants (39% men, 61% women) between 20 and 86 years old, through a semi-structured questionnaire in the Tzotzil language. From the information collected, a total of 59 species of medicinal plants were registered, belonging to 55 genera and 37 botanical families. The families Asteraceae (with 6 species and UR=51), Lamiaceae (4, UR=37) and Lauraceae (4, UR=21), are were the most representative in the study area. The highest use value index (UVI) was reported for Matricaria chamomilla (UVI=0.42), Mentha sativa (UVI=0.36) and Ruta graveolens (UVI=0.31). According to the informant consensus factor (ICF), the main pathological categories treated are were of the reproductive system (ICF=0.80), respiratory infections (ICF=0.75) and diseases of the digestive system (ICF=0.70). The species reported and their diversity of uses satisfy the needs of families with socioeconomic deficiencies.

El objetivo de la esta investigación fue registrar el uso terapéutico popular actual de plantas medicinales en la población indígena Tzotzil, en Los Altos de Chiapas, México. Los datos fueron recolectados de 59 informantes (39% hombres, 61% mujeres) entre 20 y 86 años, a través de un cuestionario semiestructurado en el idioma Tzotzil. De la información recabada, se registraron un total de 59 especies de plantas medicinales, pertenecientes a 55 géneros y 37 familias botánicas. Las familias Asteraceae (con 6 especies y RU=51), Lamiaceae (4, RU=37) y Lauraceae (4, RU=21), son fueron las más representativas en el área de estudio. El índice de valor de uso más alto (IVU) se informó para Matricaria chamomilla (IVU=0.42), Mentha sativa (IVU=0.36) y Ruta graveolens (IVU=0.31). Según el factor de consenso del informante (FCI), las principales categorías patológicas tratadas son fueron del sistema reproductivo (ICF=0.80), las infecciones respiratorias (ICF=0.75) y las enfermedades del sistema digestivo (ICF=0.70). Las especies reportadas y su diversidad de usos satisfacen las necesidades de las familias con deficiencias socioeconómicas.