Linear Ion Trap Mass Spectrometer (LITMS) Instrument Field and Laboratory Tests as Part of the ARADS Field Campaigns.

The highly compact Linear Ion Trap Mass Spectrometer (LITMS), developed at NASA Goddard Space Flight Center, combines Mars-ambient laser desorption-mass spectrometry (LD-MS) and pyrolysis-gas chromatography-mass spectrometry (GC-MS) through a single, miniaturized linear ion trap mass analyzer. The LITMS instrument is based on the Mars Organic Molecule Analyser (MOMA) investigation developed for the European Space Agency's ExoMars Rover Mission with further enhanced analytical features such as dual polarity ion detection and a dual frequency RF (radio frequency) power supply allowing for an increased mass range. The LITMS brassboard prototype underwent an extensive repackaging effort to produce a highly compact system for terrestrial field testing, allowing for molecular sample analysis in rugged planetary analog environments outside the laboratory. The LITMS instrument was successfully field tested in the Mars analog environment of the Atacama Desert in 2019 as part of the Atacama Rover Astrobiology Drilling Studies (ARADS) project, providing the first in situ planetary analog analysis for a high-fidelity, flight-like ion trap mass spectrometer. LITMS continued to serve as a laboratory tool for continued analysis of natural Atacama samples provided by the subsequent 2019 ARADS final field campaign.

Evaluación de la exposición a Hidrocarburos Aromáticos Policíclicos, salud renal y respiratoria en población indígena de Tocoy, San Antonio, S. L. P, México / Evaluation of exposure to polycyclic aromatic hydrocarbons, renal and respiratory health in the indigenous population of Tocoy, San Antonio, S. L. P, México

Resumen La contaminación del aire interior es un problema de salud pública, ya que afecta a unos 2.600 millones de personas en todo el mundo que siguen cocinando con combustibles sólidos como la madera, los residuos de las cosechas, etc. Esta exposición aumenta el factor de riesgo de desarrollo de enfermedades crónicas. La población indígena es muy susceptible a estar expuesta a mezclas de contaminantes del humo de leña como los Hidrocarburos Aromáticos Policíclicos (HAPs) debido a los métodos tradicionales de cocción. El objetivo de este trabajo fue evaluar la exposición a HAPs por medio de 10 metabolitos hidroxilados en orina de la población indígena de la Huasteca Potosina, mediante cromatografía de gases acoplada a espectrometría de masas; por otro lado, la salud renal y pulmonar fueron evaluadas con una prueba general de orina y la toxina urémica Indoxil sulfato, esta fue evaluada por medio cromatografía líquida de alto rendimiento, y la función pulmonar con una espirometría. Los resultados indican la presencia de metabolitos hidroxilados en el 89,47% de las muestras de orina, los más frecuentes fueron el 1-OH-PIRENO, el 1,2-OH-NAFTALENO. El Indoxil sulfato se presentó en el 100% de las muestras y la media era de 193,4 ± 91,85 gg/L En cuanto a la salud pulmonar, los resultados indican que algunos sujetos presentan patrones respiratorios regulares e irregulares. Estos resultados indican que la población se encuentra expuesta de manera crónica a una mezcla de contaminantes en el aire que podría producir el desarrollo de daño en los pulmones y los riñones y aumentar el riesgo al desarrollo de enfermedades crónicas.

Abstract Interior air pollution is a public health concern, it affects about 2.6 billion people around the world who still cook using solid fuels such as wood, crop wastes, among others. This exposition increases the risk of the development of non-communicable diseases (NCDs). The indigenous population is very susceptible to being exposed to mixtures of pollutants from the wood smoke such as Polycyclic Aromatic Hydrocarbons (PAHs) due to traditional methods of cooking, heating and waste burning. Therefore, the objective of this work was to evaluate the exposure to PAHs through the application of 10 hydroxylated metabolites (OH-PAHs) in the urine of the indigenous population from the Huasteca Potosina, this by gas chromatography coupled to mass spectrometry and to assess renal health of the population at the time of the study, with a general test of urine and through the uremic toxin Indoxyl Sulfate (IS), this by high-performance liquid chromatography, and the and pulmonary health with spirometry. The results indicate the presence OH-PAHs in 89.47% of the urine samples, the most frequent metabolites were 1-OH-PYRENE, 2-OH-NAPTHALENE. IS was present in 100% of the samples in mean concentrations of 193.4 ± 91.85 gg/L. For pulmonary health, the results indicate some subjects have regular and irregular respiratory patterns. These results indicate that the population is highly exposed to a mixture of pollutants in the air that might damage the lungs and kidneys and increase the risk of NCDs development.

Decidualization resistance in the origin of preeclampsia.

Preeclampsia is a major obstetrical complication with short- and long-term life-threatening consequences for both mother and child. Shallow cytotrophoblast invasion through the uterine decidua into the spiral arteries is implicated in the pathogenesis of preeclampsia, although the cause of deficient arterial invasion remains unknown. Research that is focused on the "soil"-the maternal decidua-highlights the importance of this poorly understood but influential uterine layer. Decidualization of endometrial cells regulates embryo invasion, which is essential for spiral artery remodeling and establishing the maternal-fetal interface. Exploration of the association between impaired decidualization and preeclampsia revealed suboptimal endometrial maturation and uterine natural killer cells present in the decidua before preeclampsia development. Furthermore, decidualization defects in the endometrium of women with severe preeclampsia, characterized by impaired cytotrophoblast invasion, were detected at the time of delivery and persisted 5 years after the affected pregnancy. Recently, a maternal deficiency of annexin A2 expression was found to influence aberrant decidualization and shallow cytotrophoblast invasion, suggesting that decidualization resistance, which is a defective endometrial cell differentiation during the menstrual cycle, could underlie shallow trophoblast invasion and the poor establishment of the maternal-fetal interface. Based on these findings, the transcriptional signature in the endometrium that promotes decidualization deficiency could be detected before (or after) conception. This would serve to identify women at risk of developing severe preeclampsia and aid the development of therapies focused on improving decidualization, perhaps also preventing severe preeclampsia. Here, we discuss decidualization deficiency as a contributor to the pathogenesis of pregnancy disorders with particular attention to severe preeclampsia. We also review current diagnostic strategies and discuss future directions in diagnostic methods based on decidualization.

Disrupted PGR-B and ESR1 signaling underlies defective decidualization linked to severe preeclampsia.

Background: Decidualization of the uterine mucosa drives the maternal adaptation to invasion by the placenta. Appropriate depth of placental invasion is needed to support a healthy pregnancy; shallow invasion is associated with the development of severe preeclampsia (sPE). Maternal contribution to sPE through failed decidualization is an important determinant of placental phenotype. However, the molecular mechanism underlying the in vivo defect linking decidualization to sPE is unknown. Methods: Global RNA sequencing was applied to obtain the transcriptomic profile of endometrial biopsies collected from nonpregnant women who suffer sPE in a previous pregnancy and women who did not develop this condition. Samples were randomized in two cohorts, the training and the test set, to identify the fingerprinting encoding defective decidualization in sPE and its subsequent validation. Gene Ontology enrichment and an interaction network were performed to deepen in pathways impaired by genetic dysregulation in sPE. Finally, the main modulators of decidualization, estrogen receptor 1 (ESR1) and progesterone receptor B (PGR-B), were assessed at the level of gene expression and protein abundance. Results: Here, we discover the footprint encoding this decidualization defect comprising 120 genes-using global gene expression profiling in decidua from women who developed sPE in a previous pregnancy. This signature allowed us to effectively segregate samples into sPE and control groups. ESR1 and PGR were highly interconnected with the dynamic network of the defective decidualization fingerprint. ESR1 and PGR-B gene expression and protein abundance were remarkably disrupted in sPE. Conclusions: Thus, the transcriptomic signature of impaired decidualization implicates dysregulated hormonal signaling in the decidual endometria in women who developed sPE. These findings reveal a potential footprint that could be leveraged for a preconception or early prenatal screening of sPE risk, thus improving prevention and early treatments. Funding: This work has been supported by the grant PI19/01659 (MCIU/AEI/FEDER, UE) from the Spanish Carlos III Institute awarded to TGG. NCM was supported by the PhD program FDGENT/2019/008 from the Spanish Generalitat Valenciana. IMB was supported by the PhD program PRE2019-090770 and funding was provided by the grant RTI2018-094946-B-100 (MCIU/AEI/FEDER, UE) from the Spanish Ministry of Science and Innovation with CS as principal investigator. This research was funded partially by Igenomix S.L.

A review of Environmental risks and vulnerability factors of indigenous populations from Latin America and the Caribbean in the face of the COVID-19.

Latin America and the Caribbean (LAC) was declared a new epicentre of the coronavirus pandemic by the World Health Organization (WHO) on 22 May 2020. As of 13 January 2021, the numbers of deaths and cases caused by COVID-19 in LAC reported are 552,000 and 17'485,000 respectively. LAC concentrates the largest percentage of indigenous populations throughout the world. In this region, poverty is persistent and particularly rural indigenous peoples hold the steepest barriers to health services and experience profound discrimination based on ethnicity, poverty, and language, compared to their non-indigenous counterparts. The information regarding the health of indigenous populations, in general, is scarce, and this problem is aggravated in the face of the COVID-19 pandemic. Therefore, the main objective of this work is to address the overall scenario of indigenous peoples in the Latin American and Caribbean region from March 2020 to January 2021, in this manner gathering information regarding health problems, economic, social, cultural and environmental factors that make indigenous populations in LAC particularly vulnerable to serious health effects from the COVID-19 pandemic, as well as compiling the mitigation strategies implemented in indigenous communities.

Medical and surgical management of gastroparesis: a systematic review.

BACKGROUND: Gastroparesis (GPS) is a rare disease with multiple etiologies that results in delayed gastric emptying. Diagnosis of GPS can be challenging due to its rather complex clinical presentation. Pharmacologic refractory cases require surgical interventions, all of which have yet to be standardized and characterized. OBJECTIVES: We present a review of the literature and provide an update of current therapies for patients with GPS. SETTING: Department of General Surgery, Academic Hospital, United States. METHODS: We conducted a comprehensive search in PubMed, Google Scholar, and Embase of English-written articles published in the last 38 years, with an advance title search of "gastroparesis management." Other keywords included: "surgical management" and "refractory gastroparesis." Further references were obtained through cross-reference. RESULTS: A total of 12,250 articles were selected after eliminating duplicates. Following thorough screening of selection criteria, 68 full-text articles were included for review. CONCLUSION: GPS is a challenging disease to manage. Nutritional support must remain the primary approach, followed by either medical or surgical treatment modalities if necessary. In patients with refractory gastroparesis, adjunctive therapies have been proposed as promising long-term options.

Bariatric surgery reduces the risk of developing type 2 diabetes in severe obese subjects undergoing sleeve gastrectomy.

BACKGROUND: Obesity is a major independent risk factor for developing type 2 diabetes (T2D). OBJECTIVES: Our goal in this study was to analyze the impact of laparoscopic sleeve gastrectomy in the risk reduction of developing T2D in middle-aged, severely obese nondiabetes patients. SETTING: University Hospital, United States. METHODS: We retrospectively reviewed our prospectively collected database from 2010 to 2016. All severely obese patients between 45 and 64 years of age without diabetes at baseline that underwent sleeve gastrectomy were included in our study. The T2D risk score for predicting the incidence of diabetes was measured preoperatively and at 12 months postoperatively and was based on the Framingham Offspring Study that calculates an 8-year risk of developing T2D. RESULTS: Of the 1330 patients included in this study, 6.5% (n = 86) met the criteria for the T2D risk score calculation. The population was predominantly composed of females (68.9%; n = 59) with a mean age of 52.8 ± 5.3 years. Preoperative body mass index was 43.1 ± 6.9 kg/m2 with a percentage of estimated body mass index loss and percentages of total weight loss were 72.2 ± 26.3% and 26.39 ± 18.15%, respectively, with fasting plasma glucose of 103.3 ± 14.9 mg/dL. The preoperative risk for T2D was 13.9 ± 11.6%, with an absolute risk reduction 12 months after surgery of 10.3%, corresponding to a 74.2% relative risk reduction. When comparing between sexes, risk reduction in females was slightly better than in males; however, this was not statistically significant. At 12-month follow-up, all measured variables were significantly improved, except for diastolic blood pressure. CONCLUSIONS: Laparoscopic sleeve gastrectomy significantly decreases the risk of developing T2D in middle-aged severely obese patients. Prospective studies are needed to further understand these findings.

Intraoperative Ureter Visualization Using a Novel Near-Infrared Fluorescent Dye.

Ureters can be accidentally severed during pelvic surgeries, significantly prolonging the times in the operating room to allow for complete repair of damaged ureters and leading to significant morbidities associated with consequent ureter obstruction and possible kidney dysfunction. In an effort to prevent these complications, light-emitting stents and urine-excreted dyes have been introduced to illuminate the ureter during surgery. However, problems with mechanical insertion, ureter spasm, image contrast, and localized injection have limited interest in their clinical applications. We report here the synthesis and characterization of a new near-infrared (NIR) fluorescent dye (UreterGlow) that can be injected systemically but is excreted primarily through the renal system, allowing ureter imaging with an NIR fluorescence camera. Following intravenous injection of 0.1 mg/kg UreterGlow, we have monitored the flow of UreterGlow through the proximal, medial, and distal segments of the ureter. The timing of ureter visualization was calculated from the time of injection of the drug. The null hypothesis was that "Visualization of the ureter in pigs is possible 60 min after administration of UreterGlow using an NIR camera". UreterGlow displayed excitation and emission maxima of λex = 800 nm and λem = 830 nm in phosphate buffered saline, pH 7.4, and could be imaged in the urinary tract in mice. Shortly after injection of UreterGlow into Yorkshire pigs, peristalsis of the ureter could be observed. The distal ureter could be visualized under NIR illumination after 60 min with constant fluorescence in all five pigs for >2 h. The same ureters could not be seen using visible light ( X2, p = 0.0001). Because both excitation and emission of UreterGlow occurs at >30 nm longer wavelength than most tumor-imaging fluorescent dyes, it should be possible to distinguish ureter fluorescence from tumor fluorescence with this dye.

An easy-to-use baseline scoring system to predict response to peginterferon alfa-2a in patients with chronic hepatitis B in resource-limited settings.

BACKGROUND: Approximately one-third of patients have durable responses after finite (48-week) treatment with peginterferon alfa-2a. The ability to identify patients likely to respond would be particularly useful in resource-limited settings. METHODS: Data from 1,363 peginterferon alfa-2a recipients (955 hepatitis B 'e' antigen [HBeAg]-positive and 408 -negative) in six studies were analysed. Baseline scoring systems were developed using generalized additive models and multiple logistic regression analysis to predict virological response (VR; HBV DNA <2,000 IU/ml), alone or combined with alanine aminotransferase (ALT) normalization (CR) at 24 weeks post-treatment. RESULTS: Based on the final models, points were assigned for age ≥45 (0) or <45 years (1); male (0) or female (1); hepatitis B surface antigen (HBsAg) >25,000 (0), >7,500-≤25,000 (1), >1,250-≤7,500 (2) or ≤1,250 IU/ml (4); HBV DNA >5 (0) or ≤5 log10 IU/ml (2) and ALT ratio >1-7 (0) or either ≤1 or >7 (1). Higher total scores (range 0-9) indicate higher likelihood of response. VR and CR rates were 28.5% (388/1,363) and 24.4% (332/1,363), respectively, and increased with increasing score: score 0-1 (n=257), VR 14.8%, CR 12.8%; score 2-3 (n=711), VR 23.1%, CR 20.1%; score ≥4 (n=395), VR 47.1%, CR 39.5%. CONCLUSIONS: An easy-to-use baseline scoring system for use in settings where HBeAg status and HBV genotypes are unavailable would allow clinicians to identify patients with a low or high chance of achieving a durable post-treatment response to peginterferon alfa-2a. The tool can be used to inform treatment decisions in resource-limited settings.

Cumplimiento de la norma técnica de salud para la atención integral de la tuberculosis el Centro de Salud "Atusparias" del Distrito de José Leonardo Ortiz, enero ­ junio del 2016 / Compliance of the technical health standard for the integral care of tuberculosis the "Atusparias" Health Center of the District Jose Leonardo Ortiz, january - june 2016

Objetivo: Determinar el Cumplimiento de la norma técnica de salud para la atención integral de la Tuberculosis en el Centro de Salud Atusparias en el distrito de José Leonardo Ortiz, Enero - Junio 2016. Material y métodos: Se llevó a cabo un análisis de datos de fuente secundaria, mediante la técnica check list utilizando una ficha para recolección de datos, empleando el libro de registro de sintomáticos respiratorios, libro de terapia de 1era y 2da línea, así como las tarjetas de control de tratamiento para pacientes TB diagnosticada de los meses Enero - Junio del 2016. La muestra de estudio estuvo constituida por 160 Sintomáticos Respiratorios. Resultados: los pacientes BK positivos predominó el sexo femenino, las edades entre 30 - 59 años, correspondientes a la etapa de vida adulta; el porcentaje de Sintomáticos Respiratorios examinados con dos muestras de esputo fue 43,3%; el porcentaje de visitas domiciliarias a los pacientes con diagnóstico de BK positivo fue 34,78%, el número de contactos examinados en relación a los contactos censados fue 41,09% del total. Conclusión: el 53% de incumplimiento de la Norma Técnica de Salud para la atención integral de la Tuberculosis en relación a los criterios de control de contactos, seguimiento diagnóstico y visita domiciliaria.

Efficacy and safety profile of boceprevir- or telaprevir-based triple therapy or dual peginterferon alfa-2a or alfa-2b plus ribavirin therapy in chronic hepatitis C: the real-world PegBase observational study.

BACKGROUND: The aim of the study was to determine the efficacy and safety of triple therapy with a first-generation protease inhibitor (PI; boceprevir, telaprevir) plus peginterferon alfa-2a or -2b plus ribavirin, and dual therapy (peginterferon alfa-2a or -2b plus ribavirin) in patients with chronic hepatitis C (CHC) in routine clinical practice. METHODS: PegBase was an international, prospective, observational study in which 4441 patients with CHC were enrolled in 27 countries. This analysis focuses on results in 4100 treatment-naïve and previously treated patients treated with PI-based triple therapy or dual therapy, according to the discretion of the investigator and local standards of practice. The primary efficacy outcome was sustained virological response after 12-week follow up (SVR12). RESULTS: SVR12 rates in treatment-naïve genotype (G) 1 patients were 56.6% and 62.9% for recipients of boceprevir plus peginterferon alfa-2a/ribavirin and boceprevir plus peginterferon alfa-2b/ribavirin, respectively, and 65.3% and 58.6% for recipients of telaprevir plus peginterferon alfa-2a/ribavirin and telaprevir plus peginterferon alfa-2b/ribavirin, respectively. In previously treated patients assigned to these four regimens, SVR12 rates were 43.6%, 48.3%, 60.3% and 56.1%, respectively. Among treatment-naïve patients assigned to peginterferon alfa-2a/ribavirin and peginterferon alfa-2b/ribavirin, respectively, SVR12 rates were 49.2% and 41.9% in G1 patients, 75.7% and 83.3% in G2 patients, 65.9% and 65.9% in G3 patients, and 49.7%, and 51.1% in G4 patients. The safety and tolerability of dual and triple therapy were consistent with previous reports. CONCLUSION: The efficacy and safety of first-generation PI-based triple-therapy and dual-therapy regimens in this real-world cohort were broadly comparable to those of previous studies.

Research capacity strengthening for sexual and reproductive health: a case study from Latin America.

An essential, but often overlooked part of health promotion and development support to achieve self-sufficiency in developing countries is the concomitant need to build and strengthen research capacity. This is even more challenging and critical in the area of sexual and reproductive health because of diverse interplay of socio cultural, religious, economic factors in relation to reproductive health.This paper presents the case study of HRP's efforts to build research capacity in Latin America by studying and analyzing the 5-year history of institutional development support to an institution in Paraguay. In reviewing the efforts, we identify the strengths in the approaches used by HRP, the challenges and outcomes of the process and we present recommendations for future efforts to strengthen research capacity to improve sexual and reproductive health. The authors call for greater support from and collaborative efforts of developmental partners and governments to strengthen research capacity in low and middle-income countries to improve sexual and reproductive health.

Successful management of grade III coronary perforation after percutaneous angioplasty in a high-risk patient: a case report.

Coronary perforation is a rare complication in patients undergoing percutaneous coronary angioplasty. The mortality of this complication varies depending on factors related to the patient and the procedure performed, reaching 44% in patients with Ellis type III perforation. We report the case of an 81 year old male with multiple cardiovascular risk factors, who underwent percutaneous angioplasty for unstable angina management. The patient developed grade III coronary perforation in the anterior descending artery, which was successfully managed with balloon inflation to 6 atmospheres for 10 minutes twice in the affected area, with an interval of 5 minutes between each dilatation. The patient improved and was discharged.

La perforación coronaria es una complicación rara en los pacientes sometidos a angioplastia percutánea coronaria. La mortalidad de esta complicación es variable, dependiendo de factores relacionados al paciente y al procedimiento realizado. Alcanza el 44% en pacientes con perforación tipo III, según la escala de Ellis. Presentamos el caso de un varón de 81 años con múltiples factores de riesgo cardiovascular, a quien se le realizó una angioplastia percutánea para manejo de un síndrome isquémico coronario agudo sin elevación del segmento ST (SICA STNE) de alto riesgo. El procedimiento se complicó con una perforación coronaria grado III en la arteria descendente anterior, la cual fue manejada exitosamente con dilatación de balón a 6 atmósferas por 10 minutos en dos oportunidades en la zona afectada, con intervalo de 5 minutos entre insuflaciones. El paciente evolucionó favorablemente y fue dado de alta.

Global Challenges and Solutions: Role of Telemedicine in ST-Elevation Myocardial Infarction Interventions.

Major disparities exist between developed and developing countries in the management of acute myocardial infarction (AMI). These pronounced differences result in significantly increased morbidity and mortality from AMI in different regions of the world. Lack of infrastructure, insurance, facilities, and skilled personnel are the major constraints. Primary percutaneous coronary intervention has revolutionized the treatment of AMI; however, its global use is limited by the listed constraints. Telemedicine provides an efficient methodology that can hugely increase access and accuracy of AMI management.

Water relations, nutrient content and developmental responses of Euonymus plants irrigated with water of different degrees of salinity and quality.

For 20 weeks, the physiological responses of Euonymus japonica plants to different irrigation sources were studied. Four irrigation treatments were applied at 100 % water holding capacity: control (electrical conductivity (EC) <0.9 dS m(-1)); irrigation water normally used in the area (irrigator's water) IW (EC: 1.7 dS m(-1)); NaCl solution, NaCl (EC: 4 dS m(-1)); and wastewater, WW (EC: 4 dS m(-1)). This was followed by a recovery period of 13 weeks, when all the plants were rewatered with the same amount and quality of irrigation water as the control plants. Despite the differences in the chemical properties of the water used, the plants irrigated with NaCl and WW showed similar alterations in growth and size compared with the control even at the end of the recovery period. Leaf number was affected even when the EC of the irrigation water was of 1.7 dS m(-1) (IW), indicating the salt sensitivity of this parameter. Stomatal conductance (gs) and photosynthesis (Pn), as well as stem water potential (Ψstem), were most affected in plants irrigated with the most saline waters (NaCl and WW). At the end of the experiment the above parameters recovered, while IW plants showed similar values to the control. The higher Na(+) and Cl(+) uptake by NaCl and WW plants led them to show osmotic adjustment throughout the experiment. The highest amount of boron found in WW plants did not affect root growth. Wastewater can be used as a water management strategy for ornamental plant production, as long as the water quality is not too saline, since the negative effect of salt on the aesthetic value of plants need to be taken into consideration.

Experimental and DFT studies of the conversion of ethanol and acetic acid on PtSn-based catalysts.

Reaction kinetics studies were conducted for the conversions of ethanol and acetic acid over silica-supported Pt and Pt/Sn catalysts at temperatures from 500 to 600 K. Addition of Sn to Pt catalysts inhibits the decomposition of ethanol to CO, CH4, and C2H6, such that PtSn-based catalysts are active for dehydrogenation of ethanol to acetaldehyde. Furthermore, PtSn-based catalysts are selective for the conversion of acetic acid to ethanol, acetaldehyde, and ethyl acetate, whereas Pt catalysts lead mainly to decomposition products such as CH4 and CO. These results are interpreted using density functional theory (DFT) calculations for various adsorbed species and transition states on Pt(111) and Pt3Sn(111) surfaces. The Pt3Sn alloy slab was selected for DFT studies because results from in situ (119)Sn Mössbauer spectroscopy and CO adsorption microcalorimetry of silica-supported Pt/Sn catalysts indicate that Pt-Sn alloy is the major phase present. Accordingly, results from DFT calculations show that transition-state energies for C-O and C-C bond cleavage in ethanol-derived species increase by 25-60 kJ/mol on Pt3Sn(111) compared to Pt(111), whereas energies of transition states for dehydrogenation reactions increase by only 5-10 kJ/mol. Results from DFT calculations show that transition-state energies for CH3CO-OH bond cleavage increase by only 12 kJ/mol on Pt3Sn(111) compared to Pt(111). The suppression of C-C bond cleavage in ethanol and acetic acid upon addition of Sn to Pt is also confirmed by microcalorimetric and infrared spectroscopic measurements at 300 K of the interactions of ethanol and acetic acid with Pt and PtSn on a silica support that had been silylated to remove silanol groups.