Real-time monitoring of CdTe quantum dots growth in aqueous solution.

Quantum dots (QDs) are remarkable semiconductor nanoparticles, whose optical properties are strongly size-dependent. Therefore, the real-time monitoring of crystal growth pathway during synthesis gives an excellent opportunity to a smart design of the QDs luminescence. In this work, we present a new approach for monitoring the formation of QDs in aqueous solution up to 90 °C, through in situ luminescence analysis, using CdTe as a model system. This technique allows a detailed examination of the evolution of their light emission. In contrast to in situ absorbance analysis, the in situ luminescence measurements in reflection geometry are particularly advantageous once they are not hindered by the concentration increase of the colloidal suspension. The synthesized particles were additionally characterized using X-ray diffraction analysis, transition electron microscopy, UV-Vis absorption and infrared spectroscopy. The infrared spectra showed that 3-mercaptopropionic acid (MPA)-based thiols are covalently bound on the surface of QDs and microscopy revealed the formation of CdS. Setting a total of 3 h of reaction time, for instance, the QDs synthesized at 70, 80 and 90 °C exhibit emission maxima centered at 550, 600 and 655 nm. The in situ monitoring approach opens doors for a more precise achievement of the desired emission wavelength of QDs.

Comprehensive profiling of ceramides in human serum by liquid chromatography coupled to tandem mass spectrometry combining data independent/dependent acquisition modes.

Ceramides are sphingolipids with a structural function in the cell membrane and are involved in cell differentiation, proliferation and apoptosis. Recently, these chemical species have been pointed out as potential biomarkers in different diseases, due to their abnormal levels in blood. In this research, we present an overall strategy combining data-independent and dependent acquisitions (DIA and DDA, respectively) for identification, confirmation, and quantitative determination of ceramides in human serum. By application of liquid chromatography-tandem mass spectrometry (LC-MS/MS) method in DIA mode we identified 49 ceramides including d18:1, d18:0, d18:2, d16:1, d17:1 and t18:0 species. Complementary, quantitative determination of ceramides was based on a high-throughput and fully automated method consisting of solid-phase extraction on-line coupled to LC-MS/MS in DDA to improve analytical features avoiding the errors associated to sample processing. Quantitation limits were at pg mL-1 level, the intra-day and between-days variability were below 20 and 25 %, respectively; and the accuracy, expressed as bias, was always within ±25 %. The proposed method was tested with the CORDIOPREV cohort in order to obtain a qualitative and quantitative profiling of ceramides in human serum. This characterization allowed identifying d18:1 ceramides as the most concentrated with 70.8% of total concentration followed by d18:2 and d18:0 with 13.0 % and 8.8 %, respectively. Less concentrated ceramides, d16:1, d17:1 and t18:0, reported a 7.1 % of the total content. Combination of DIA and DDA LC-MS/MS analysis enabled to profile qualitative and quantitatively ceramides in human serum.

Enhanced stress resistance of Bifidobacterium breve NRBB57 by induction of stress proteins at near-zero growth rates.

Bifidobacterium breve is a common habitant of the human gut and is used as probiotic in functional foods. B. breve has to cope with multiple stress conditions encountered during processing and passage through the human gut, including high temperature, low pH and exposure to oxygen. Additionally, during industrial processing and in the gut, B. breve could encounter nutrient limitation resulting in reduced growth rates that can trigger adaptive stress responses. For this reason, it is important to develop culture methods that elicit resistance to multiple stresses (robustness) encountered by the bacteria. To investigate the impact of caloric restriction on robustness of the probiotic B. breve NRBB57, this strain was grown in lactose-limited chemostat cultures and in retentostat for 21 days, at growth rates ranging from 0.4 h-1 to 0.00081 h-1. Proteomes of cells harvested at different growth rates were correlated to acid, hydrogen peroxide and heat stress survival capacity. Comparative proteome analysis showed that retentostat-grown cells had significantly increased abundance of a variety of stress proteins involved in protein quality maintenance and DNA repair (DnaJ, Hsp90, FtsH, ClpB, ClpP1, ClpC, GroES, RuvB, RecA), as well as proteins involved in oxidative stress defence (peroxiredoxin, ferredoxin, thioredoxin peroxidase, glutaredoxin and thioredoxin reductase). Exposure to three different stress conditions, 45 °C, pH 3, and 10 mM H2O2, showed highest stress resistance of retentostat cells sampled at week 2 and week 3 grown at 0.0018 and 0.00081 h-1. Our findings show that cultivation at near-zero growth rates induces higher abundance of stress defence proteins contributing to the robustness of B. breve NRBB57, thereby offering an approach that may support its production and functionality.

Association between preoperative baseline pulse pressure and estimated pulse wave velocity and acute renal failure and mortality following colorectal surgery. A single-centre observational study.

BACKGROUND: Elevated pulse wave velocity is a haemodynamic parameter considered to be a risk factor for the development of cardiovascular alterations, while pulse pressure is a predictor of cardiovascular complications and development of acute renal failure after both cardiac and non-cardiac surgery. Our objective was to determine whether baseline pulse pressure and estimated pulse wave velocity are associated with renal failure and 30-day mortality following colorectal surgery. METHODS: Retrospective observational study. A total of 816 adult patients undergoing elective colorectal surgery were evaluated by performing multivariable logistic regression analysis to determine whether baseline pulse pressure and estimated pulse wave velocity were independently associated with complications, specifically renal failure and 30-day postoperative mortality, and whether pulse pressure and estimated pulse wave velocity thresholds correlated with outcomes. RESULTS: Baseline pulse pressure was 56.00 mmHg (45.00;68.00) and estimated pulse wave velocity was 13.16 m/s (10.76;14.85). Baseline pulse pressure was not associated with acute renal failure or mortality in the univariate model. Baseline estimated pulse wave velocity was not associated with complications, acute renal failure, or mortality. An estimated pulse wave velocity of 13.78 m/s significantly predicted acute renal failure (AUC 0.654 [0.588-0.720]) and mortality (AUC 0.698 [0.600-0.796]). CONCLUSIONS: Neither pulse pressure nor preoperative baseline estimated pulse wave velocity were associated with acute renal failure or postoperative mortality. The preoperative estimated pulse wave velocity threshold of 13.78 m/s predicted an increased risk of acute renal failure and postoperative mortality.

Multidisciplinary approach to orbital embryonic rhabdomyosarcoma: About a case.

Of the head and neck tumoral lesions in children and adolescents, 5%-10% are primary malignant tumors. Among these tumors, orbital rhabdomyosarcoma stands out, which is the most common primary soft tissue sarcoma in children. Its diagnosis requires a high degree of clinical suspicion, and it can be corroborated with a series of examinations, in order to stage it and carry out the appropriate treatment. Currently, surgery and chemotherapy are the primary treatments, and the use of conventional radiotherapy is limited to cases where previous treatments fail or there is a risk of recurrence. The following case report aims to expose the clinical picture, diagnosis, staging and integral treatment of orbital rhabdomyosarcoma, as well as the interdisciplinary management that was performed to improve the patient's prognosis.

Association between preoperative baseline pulse pressure and estimated pulse wave velocity and acute renal failure and mortality following colorectal surgery. A single-centre observational study. / Asociación entre la presión de pulso y la velocidad onda pulso estimada basal preoperatoria con las complicaciones postoperatorias, insuficiencia renal aguda y mortalidad tras cirugía colorrectal. Estudio unicéntrico observacional.

BACKGROUND: Elevated pulse wave velocity is a haemodynamic parameter considered to be a risk factor for the development of cardiovascular alterations, while pulse pressure is a predictor of cardiovascular complications and development of acute renal failure after both cardiac and non-cardiac surgery. Our objective was to determine whether baseline pulse pressure and estimated pulse wave velocity are associated with renal failure and 30-day mortality following colorectal surgery. METHODS: Retrospective observational study. A total of 816 adult patients undergoing elective colorectal surgery were evaluated by performing multivariable logistic regression analysis to determine whether baseline pulse pressure and estimated pulse wave velocity were independently associated with complications, specifically renal failure and 30-day postoperative mortality, and whether pulse pressure and estimated pulse wave velocity thresholds correlated with outcomes. RESULTS: Baseline pulse pressure was 56.00mmHg (45.00;68.00) and estimated pulse wave velocity was 13.16m/s (10.76;14.85). Baseline pulse pressure was not associated with acute renal failure or mortality in the univariate model. Baseline estimated pulse wave velocity was not associated with complications, acute renal failure, or mortality. An estimated pulse wave velocity of 13.78m/s significantly predicted acute renal failure (AUC 0.654 [0.588-0.720]) and mortality (AUC 0.698 [0.600-0.796]). CONCLUSIONS: Neither pulse pressure nor preoperative baseline estimated pulse wave velocity were associated with acute renal failure or postoperative mortality. The preoperative estimated pulse wave velocity threshold of 13.78m/s predicted an increased risk of acute renal failure and postoperative mortality.

Oral selenium improved the disease activity in patients with mild Graves' orbitopathy.

BACKGROUND: Graves' orbitopathy (GO) is the most common extrathyroidal manifestation of Graves' disease (GD), an autoimmune disorder arising from the activity of T lymphocytes against antigens that infiltrate thyroid tissue, orbital tissue and extraocular muscles. An increase in oxidative stress has been discovered in autoimmune thyroid disease, encouraging investigation into new forms of treatment. Selenium has been described as a treatment option given its antioxidant properties. The present study evaluates the decrease of progression and inflammatory signs in patients with mild GO with oral selenium supplementation. METHODS: Controlled, randomized, single center trial at an ophthalmology referral center in Mexico City. Patients at least 18years of age with mild GO according to the CAS classification were included; exclusion criteria in addition to corticosteroid treatment included smokers or selenium allergy. Each patient was randomized into one of two groups. Group A took placebo tablets which consisted of 100µg of starch twice a day for 6months, and group B took a 100µg selenium tablet twice a day for 6months. The patients from both groups were examined and evaluated using a CAS score before and after the first, third and sixth month of treatment. RESULTS: Thirty eyes of 30 patients were studied. The pretreatment values showed no statistically significant differences between groups (P>0.05). Intergroup analysis showed statistically significant differences in palpebral fissure and CAS score between the pretreatment values and six months after treatment in the selenium group (P<0.05). No differences were found in any variables in the placebo group during the study period (P>0.05). No adverse events were reported. CONCLUSIONS: This is the first study in a Mexican population demonstrating that oral selenium decreases clinical activity and stops progression in patients with mild GO.

Multidisciplinary approach to orbital embryonic rhabdomyosarcoma: about a case. / Abordaje multidisciplinario de un rabdomiosarcoma embrionario orbitario: a propósito de un caso.

Of the head and neck tumoral lesions in children and adolescents, 5 to 10% are primary malignant tumors. Among these tumors, orbital rhabdomyosarcoma stands out, which is the most common primary soft tissue sarcoma in children. Its diagnosis requires a high degree of clinical suspicion, and it can be corroborated with a series of examinations, in order to stage it and carry out the appropriate treatment. Currently, surgery and chemotherapy are the primary treatments, and the use of conventional radiotherapy is limited to cases where previous treatments fail or there is a risk of recurrence. The following case report aims to expose the clinical picture, diagnosis, staging and integral treatment of orbital rhabdomyosarcoma, as well as the interdisciplinary management that was performed to improve the patient's prognosis.

Uma análise histórico-crítica sobre o desenvolvimento das normas brasileiras relacionadas a queijos artesanais / [A critical-historical analysis of the continuous development of Brazilian legislation related to artisanal cheeses]

Diferentes tipos de queijos artesanais são produzidos, comercializados e consumidos no Brasil, o que impulsiona o constante desenvolvimento de normas por órgãos oficiais, como o Mapa. A criação do Suasa e do Sisbi-POA foi fundamental para esse setor, por permitir um sistema de equivalência na fiscalização e por ampliar a distribuição. Ainda, o Mapa passou a permitir que queijos artesanais produzidos com leite cru pudessem ser maturados em um período inferior a 60 dias, desde que comprovada sua inocuidade. A redução do tempo de maturação é um tema controverso e polêmico, já que não há critérios específicos que estudos científicos devem contemplar, o que permite múltiplas interpretações de dados. Com a criação e a regulamentação do selo Arte, a fiscalização dos produtos artesanais foi designada aos órgãos de agricultura, pecuária e de saúde pública, em complementação à atribuição já prevista pelo Mapa e pelo Sisbi-POA. Ainda, o selo Arte atribui aos órgãos de inspeção uma função orientadora, atividade que deveria ser prioritariamente executada por agências de extensão e associações. As normas que balizam a produção e comercialização de produtos artesanais devem ser frequentemente atualizadas, devido aos constantes avanços científicos na área e para assegurar a oferta de produtos com qualidade e inócuos aos consumidores.(AU)

Different artisanal cheeses are produced, commercialized and consumed in Brazil, leading to a constant development of related rules by the MAPA and other official agencies. The establishment of two national programs (SUASA and SISBI-POA) allowed an equivalence in inspection system and an expanded distribution. Also, MAPA allowed ripening time lower than 60 days for artisanal raw milk cheeses, based on scientific studies that assure their safety. However, lowering the ripening period is still controversial, once there are no proper established criteria for such scientific studies, leading to potential multiple interpretation of data. The newly established ARTE certification transferred the inspection responsibilities of artisanal products to secretaries of agriculture, livestock and health, in support of what was already predicated by MAPA and SISBI-POA. Based on ARTE certification, the inspection service must also provide orientation guidance to producers, which should be done specifically by extension organs and associations. The norms that guide the production and commercialization of these artisanal products often need to be updated, but based on well-established methodologies and procedures, to ensure the distribution of suitable products to consumers.(AU)

Estimation of statistical properties of rough surface profiles from the Hurst exponent of speckle patterns.

We applied the Hurst exponent technique to an experimental study of rough metallic surface profiles and the speckle patterns generated by them. Characterization of important statistical properties of the surface profile and speckle patterns were performed. We observed a clear correlation between the Hurst exponent of a surface profile and the one calculated from the associated speckle patterns. Therefore, in principle, information of the Hurst exponent of the profile can be obtained from the Hurst exponent of speckle patterns. Range and sampling analyses were performed in the Hurst exponent calculations showing the robustness of the method. As an additional application, we performed a basic simulation to show that the Hurst exponent is sensitive to surface waviness.

A new species of Creptotrematina (Trematoda: Allocreadiidae) from characid fishes of Brazil: morphological and molecular data.

A new species of Creptotrematina Yamaguti, 1954 was collected from characid fishes, Astyanax fasciatus (Cuvier, 1819) and Astyanax lacustris Lucerna & Soares, 2016 from the Batalha River in the State of Sao Paulo, Brazil. The new species most closely resembles Creptotrematina aguirrepequenoi, but differs by the elongated shape of vitelline follicles, the extension of these follicles in the posterior end of body and the fact that they are not confluent. The morphological differences were confirmed through molecular data. Three specimens were sequenced, and molecular analyses were based on the internal transcribed spacers 2 and D1-D3 domains of the 28S ribosomal RNA gene. The obtained topologies showed the new species as a sister taxon of C. aguirrepequenoi, a species originally described from Astyanax mexicanus in Mexico, and later found in Astyanax aeneus in Costa Rica. Isolates of the new species are reciprocally monophyletic, and genetic distance values are similar to those observed in other species pairs within Allocreadiidae. These findings corroborate that the genus Creptotrematina is mostly a parasite of characids, and widely extended across the Americas, with representative species occurring between Argentina and northern Mexico.

Synthesis and structural studies on (E)-3-(2,6-difluorophenyl)-1-(4-fluorophenyl)prop-2-en-1-one: a promising nonlinear optical material.

A new fluorinated chalcone (E)-3-(2,6-difluorophenyl)-1-(4-fluorophenyl)prop-2-en-1-one was synthesized in 90% yield and crystallized by a slow evaporation technique. Its full structural characterization and purity were determined by scanning electron microscopy, infrared spectroscopy, gas chromatography-mass spectrometry, 1H, 13C and 19F nuclear magnetic resonance, thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), Raman microspectroscopy, UV-Vis absorption spectroscopy, single crystal X-ray diffraction (XRD) and Hirshfeld surface (HS) analysis. The fluorinated chalcone crystallized in centrosymmetric space group P21/c stabilized by the C-H⋯O and C-H⋯F interactions and the π⋯π contact. The crystalline environment was simulated through the supermolecule approach where a bulk with 378 000 atoms was built. The electric parameters were calculated at the DFT/CAM-B3LYP/6-311++G(d,p) level as function of the electric field frequency. The macroscopic parameters such as linear refractive index and third-order nonlinear susceptibility (χ (3)) were calculated, and the results were compared with experimental data obtained from the literature. The χ (3)-value for the chalcone crystal is 369.294 × 10-22 m2 V-2, higher than those obtained from a few similar types of molecule, showing that the chalcone crystal can be considered as a nonlinear optical material. Also, molecular theoretical calculations such as infrared spectrum assignments, frontier molecular orbital analysis and MEP were implemented, revealing that the most positive region is around the hydrogen atoms of the aromatic rings, and electrophilic attack occurs on the carbonyl group.

Development of a qualitative/quantitative strategy for comprehensive determination of polar lipids by LC-MS/MS in human plasma.

Polar lipids, especially glycerophospholipids, constitute the main components of cell membranes and are precursors of signaling molecules in many cellular and physiological processes. For this reason, the development of methods with high capability for detection of polar lipids in biological samples is required. In this research, the objective was to develop a method for comprehensive qualitative/quantitative determination of polar lipids in plasma by a combination of acquisition methods with a triple quadrupole mass analyzer. The strategy was optimized in two steps: (a) a first step for detection of lipids by monitoring selective fragmentation patterns representative of each lipid family and (b) a second step for confirmation of lipid species by detection and identification of product ions associated with the conjugated fatty acids. The acquisition list was divided into two multiple reaction monitoring (MRM) methods to ensure the detection of all transitions with suited instrumental sensitivity according to chromatographic retention time and relative abundance in plasma. The combination of the two MRM methods allowed the detection of 398 polar lipids in plasma in 64 min. Precision, estimated as within-day variability, was below 6.8% for all determined lipid families, while between-day variability was below 24.0%. This strategy has been applied to a cohort formed by 384 individuals in order to obtain a qualitative and quantitative distribution of polar lipids in human plasma. The most concentrated lipid families in relative terms were lysophospholipids, plasmalogens, and phosphatydilcholines, with mean relative concentration of 58.0, 17.1, and 8.3%, respectively. Then, sphingomyelins and phosphatidylethanolamines reported a relative concentration of 2.0%, followed by phosphatidylserines, with 1.1%. Graphical abstract.

Morphological and molecular analyses of Pseudomazocraes sulamericana n. sp., Pseudomazocraes selene Hargis, 1957, Cemocotyle carangis (MacCallum, 1913) and Zeuxapta seriolae (Meserve, 1938) (Monogenea: Mazocraeidea) from carangid fishes in the south-western Atlantic Ocean.

An integrative taxonomy approach was followed to analyse morphological and molecular characters of the monogenean species Pseudomazocraes selene, Cemocotyle carangis and Zeuxapta seriolae; specimens were collected from the gills of the carangid fishes Selene vomer, Caranx latus and Seriola lalandi caught off the coasts of the states of Rio de Janeiro and Santa Catarina, Brazil. The research revealed the presence of Pseudomazocraes sulamericana n. sp., which can be differentiated from other congeners by the shape of clamps mid-sclerite possessing a ventral piece bifurcated at the end, with large and right-angled edges of almost the same length, and by the shape of larval hooks and rounded terminal lappet. New genetic sequences include partial 28S and 18S rDNA genes for all species, ITS1 and 5.8S rDNA for Zeuxapta seriolae and Cemocotyle carangis, and ITS2 and mtDNA cox1 for C. carangis. The phylogenetic concatenated analysis based on partial 28S rDNA and 18S rDNA sequences confirmed the position of C. carangis and Z. seriolae within the Heteraxinidae. The previous phylogenetic position of Chauhaneidae was discussed based on morphological studies and it is now confirmed by molecular data that Chauhaneidae is the sister group of Allodiscocotylidae and Protomicrocotylidae.

Operational Characterization of Pressure Regulating Valves.

The functionality of pressure regulating valves (PRVs) is important for proper uniformity and efficiency of irrigation during center pivot irrigation, especially when the center pivot operates on sloping terrain. In practice, the regulated pressure at the PRV outlet is slightly influenced by its inlet pressure, the flow rate through it, and hysteresis effects. The objectives of this work were (a) to evaluate operational characteristics of PRVs based on requirements stated by ISO 10522 (1993) and (b) to model the regulated pressure as a function of inlet pressure and flow rate through the valve considering hysteresis. We carried out tests to evaluate regulation uniformity, regulation curve, hysteresis, and the regulated pressure as function of flow rate and inlet pressure. The following three models of PRVs were evaluated: 10 PSI, 15 PSI, and 20 PSI. For each model, three samples were tested under increasing and decreasing conditions of inlet pressure, within the range from 49.03 to 784.53 kPa, with increments of 49.03 kPa. In addition, flow rates were tested within the range of 0 and 4 m3 h-1. From the gathered data, models to predict outlet pressure as a function of inlet pressure and flow rate were fitted.

Effect of Akt activation and experimental pharmacological inhibition on responses to neoadjuvant chemoradiotherapy in rectal cancer.

BACKGROUND: Neoadjuvant chemoradiotherapy (CRT) is one of the preferred initial treatment strategies for locally advanced rectal cancer. Responses are variable, and most patients still require surgery. The aim of this study was to identify molecular mechanisms determining poor response to CRT. METHODS: Global gene expression and pathway enrichment were assessed in pretreatment biopsies from patients with non-metastatic cT2-4 N0-2 rectal cancer within 7 cm of the anal verge. Downstream Akt activation was assessed in an independent set of pretreatment biopsies and in colorectal cancer cell lines using immunohistochemistry and western blot respectively. The radiosensitizing effects of the Akt inhibitor MK2206 were assessed using clonogenic assays and xenografts in immunodeficient mice. RESULTS: A total of 350 differentially expressed genes were identified, of which 123 were upregulated and 199 downregulated in tumours from poor responders. Mitochondrial oxidative phosphorylation (P < 0·001) and phosphatidylinositol signalling pathways (P < 0·050) were identified as significantly enriched pathways among the set of differentially expressed genes. Deregulation of both pathways is known to result in Akt activation, and high immunoexpression of phosphorylated Akt S473 was observed among patients with a poor histological response (tumour regression grade 0-2) to CRT (75 per cent versus 48 per cent in those with a good or complete response; P = 0·016). Akt activation was also confirmed in the radioresistant cell line SW480, and a 50 per cent improvement in sensitivity to CRT was observed in vitro and in vivo when SW480 cells were exposed to the Akt inhibitor MK2206 in combination with radiation and 5-fluorouracil. CONCLUSION: Akt activation is a key event in the response to CRT. Pharmacological inhibition of Akt activation may enhance the effects of CRT. Surgical relevance Organ preservation is an attractive alternative in rectal cancer management following neoadjuvant chemoradiotherapy (CRT) to avoid the morbidity of radical surgery. Molecular steps associated with tumour response to CRT may provide a useful tool for the identification of patients who are candidates for no immediate surgery. In this study, tumours resistant to CRT were more likely to have activation of specific genetic pathways that result in phosphorylated Akt (pAkt) activation. Pretreatment biopsy tissues with high immunoexpression of pAkt were more likely to exhibit a poor histological response to CRT. In addition, the introduction of a pAkt inhibitor to cancer cell lines in vitro and in vivo led to a significant improvement in sensitivity to CRT. Identification of pAkt-activated tumours may thus allow the identification of poor responders to CRT. In addition, the concomitant use of pAkt inhibitors to increase sensitivity to CRT in patients with rectal cancer may constitute an interesting strategy for increasing the chance of a complete response to treatment and organ preservation.

Profilaxia da trombose venosa profunda em cirurgia bariátrica: estudo comparativo com doses diferentes de heparina de baixo peso molecular / Deep venous thrombosis prevention in bariatric surgery: comparative study of different doses of low weight molecular heparin

Contexto: A cirurgia bariátrica é considerada a melhor opção para o tratamento da obesidade, cujos pacientes são considerados de alto risco para fenômenos tromboembólicos. Objetivos: Comparar o uso de doses diferentes de heparina de baixo peso molecular (HBPM) na profilaxia da trombose venosa profunda (TVP) em pacientes candidatos à cirurgia bariátrica em relação ao risco de TVP, alteração na dosagem do fator anti-Xa e sangramento pré ou pós-operatório. Métodos: Estudo comparativo transversal em pacientes submetidos à cirurgia bariátrica distribuídos em dois grupos, que receberam doses de HBPM de 40 mg (grupo controle, GC) e 80 mg (grupo de estudo, GE). Foram avaliados por ultrassonografia vascular e dosagem de KPTT, TAP, plaquetas e fator anti-Xa. Resultados: Foram avaliados 60 pacientes, sendo 34 no GC e 26 no GE. Foi observada diferença significativa somente no peso (p = 0,003) e índice de massa corporal (p = 0,018) no GE em relação ao GC. Não houve diferença na dosagem de KPTT, TAP, plaquetas e fator anti-Xa entre os grupos. Não foram detectados TVP ou sangramentos significativos em ambos os grupos. Conclusões: Não houve diferença estatisticamente significativa na utilização de doses maiores de HBPM na profilaxia da TVP em pacientes candidatos à cirurgia bariátrica em relação ao risco de TVP, dosagem do fator anti-Xa e sangramento pré ou pós-operatório

Background: Bariatric surgery is considered the best treatment option for patients with obesity who are classed as high risk for thromboembolic events. Objectives: To compare two different doses of low weight molecular heparin (LWMH) for prevention of deep venous thrombosis (DVT) in candidates for bariatric surgery, in terms of DVT risk, abnormal anti-Xa levels, and preoperative and/or postoperative bleeding. Methods: A cross-sectional comparative study of bariatric surgery patients divided into two groups given different doses of LWMH; 40 mg of LWMH (control group, CG) and 80 mg of LWMH (study group, SG), both evaluated by vascular ultrasonography (VU) and according to the results of PTT, PT, platelets, and anti-Xa factor assays. Results: Sixty patients were evaluated, 34 in the CG and 26 in the SG. The only significant differences between the patients in the SG and the CG were weight (p = 0.003) and body mass index (p = 0.018). There were no differences between the groups in PTT, PT, platelets, or anti-Xa factor levels. There was no DVT or significant bleeding in either group. Conclusions: There were no statistical differences when higher doses of LWMH were used for prevention of DVT in bariatric surgery patients, in terms of DVT risk, anti-Xa factor levels, or preoperative and postoperative bleeding