Sorption of Cr(III) and Cr(VI) to K2Mn4O9 nanomaterial a Study of the effect of pH, time, temperature and interferences.

A Rancieite type material (K2Mn4O9) nanomaterial was synthesized and tested for the removal of chromium (III) and chromium (VI) from aqueous solutions. The synthesized nanomaterial was characterized using powder XRD and SEM. XRD showed weak diffraction peaks at only at the angles associated with K2Mn4O9. The SEM corroborated that the nanoparticles were present; however, the nanoparticles were clustered into larger aggregates. Batch studies were performed to determine the optimum pH, capacity, time dependency, interferences, and the thermodynamics of the binding. The optimum pH for the binding of Cr(III) and Cr(VI) were determined to be pH 5 and pH 2, respectively. Isotherm studies were performed at temperatures of 4 , 25 , and 45 for Cr(III) and Cr(VI) and showed binding capacities of 21.7 mg/g, 36.5 mg/g, 41.8 mg/g for Cr(III). The Cr(VI) binding capacities were 4.22 mg/g, 4.08 mg/g, and 3.25 mg/g at the respective temperatures. The thermodynamic studies showed that the binding processes for the reactions were spontaneous and endothermic, with a ΔH was 17.54 kJ/mol for Cr(III) and 6.05 kJ/mol for Cr(VI). The of sorption for Cr(III) were determined to be -3.88 kJ/mol, -5.83 kJ/mol and -7.03 kJ/mol at the aforementioned temperatures. The ΔG values for the Cr(VI) sorption were determined to be -4.89 kJ/mol, -5.64 kJ/mol, and -6.05 kJ/mol. In addition, the ΔS values for Cr(III) and Cr(VI) were determined to be 77.92 J/mol and 39.49 J/mol, respectively. The thermodynamics indicate that the binding of Cr(III) and Cr(VI) is spontaneous and endothermic.

The Porphyromonas gingivalis O antigen is required for inhibition of apoptosis in gingival epithelial cells following bacterial infection.

BACKGROUND AND OBJECTIVE: Porphyromonas gingivalis infection induces apoptosis inhibition in gingival epithelial cells; however, it is not fully understood which bacterial effectors are involved in this process. The aim of this study is to evaluate whether the P. gingivalis lipopolysaccharide (LPS), specifically the O-antigen region, affects adherence, invasion, viability and apoptosis of gingival epithelial cells. MATERIAL AND METHODS: Gingival epithelial cells (OKF6/TERT2 line) were infected by different freshly prepared P. gingivalis clinical isolates, obtained from subjects with chronic periodontitis (CP3 and CP4) and healthy individuals (H1 and H3). Periodontitis and healthy isolates show differences in O-antigen production, as healthy isolates lack the O-antigen region. In addition, cells were infected by a site-specific mutant lacking the O-antigen portion. After 24 h postinfection, cell proliferation, viability and apoptosis were evaluated by Trypan blue, MTS and annexin V assays, respectively. Bacterial invasion, adhesion and proliferation were measured by gentamicin/metronidazole protection assays. Finally, toll-like receptor (TLR)2 and TLR4 mRNA expression was evaluated by quantitative reverse transcription-polymerase chain reaction. Statistical analysis was performed using ANOVA, Tukey's or Dunnett's tests (p < 0.05). RESULTS: At 24 h postinfection, strains lacking the O-antigen region (healthy isolates and O-antigen ligase-deficient strain) were unable to increase proliferation and viability, or decrease apoptosis as compared with strains producing intact LPS (periodontitis isolates and reference strain). However, the presence of the O-antigen neither contributed to changes in the ability of the bacteria to adhere to or invade cells, nor to intracellular survival. The presence of O-antigen also increased the expression of TLR4 (nearly sixfold), which correlated with inhibition of apoptosis. CONCLUSION: The O-antigen region of P. gingivalis LPS is required to increase gingival epithelial cell viability upon infection by bacteria and this increase is attributable to a reduction in apoptosis. Moreover, although bacterial internalization is required, the effects observed are not due to alterations in P. gingivalis adherence, invasion or intracellular survival. Interestingly, inhibition of apoptosis correlates with increased TLR4 expression, suggesting a role for TLR4 in this process.

Trends in World Dental Research: an overview of the last three decades using the Web of Science.

OBJECTIVE: The objective of this paper is to analyse the scientific activity of dental sciences over the last 30 years. MATERIALS AND METHODS: Dental-research output was identified by retrieving all citable dental documents in the Web of Science (WoS) database in the periods 1986-1988, 1996-1998, and 2006-2008. For this, a two-phase search strategy was designed: firstly, output in Dentistry, Oral Surgery, and Medicine (DOSM) Journal Citation Reports (JCR) category journals were compiled; secondly, for journal documents of other JCR categories but related to Dentistry (Non-DOSM), an innovative search strategy was designed based on a double criterion, thematic and institutional. RESULTS: The results showed that DOSM production increased in absolute but decreased in relative terms over the last 30 years. The JCR categories where dental researchers publish also varied. Surprisingly, the geographic distribution of the production shows a growing concentration of the steadily fewer countries, a previously undescribed phenomenon, while the thematic analysis reveals that this production continued to form four broad thematic areas encompassing the remaining specialties: Dental Materials Prosthodontics, Orthodontics, and General Dentistry. CONCLUSIONS: Scientific production in dentistry has changed in the past three decades both quantitatively and qualitatively, as well as their geographical distribution despite being structured around the same specialties. CLINICAL RELEVANCE: In this study, along with some key messages about the key shifts in publication trends, in terms of subject, where published and by whom, we propose a new methodology which could be useful to professionals as well as researchers, in which the exhaustivity and precision rates for scientific information retrieval improve.

Adaptation culturally and linguistically to the Chilean population and validation the Dry Eye Questionnaire 5.

BACKGROUND AND OBJECTIVE: There are different methods for evaluating dry eye disease (DID), including questionnaires that analyze different aspects of its symptoms, which are important for its better understanding and therapeutic management. The Dry Eye Questionnaire 5 (DEQ-5), is unique in its kind, because in addition to its simplicity, it measures symptoms in 4 dimensions. The aim of this study is to adapt culturally and linguistically and validate this instrument to the Chilean population. MATERIAL AND METHODS: For the adaptation, the translation and retro-translation of the original version was carried out, its linguistic analysis, the pilot test and the expert panel review (which included a linguistics specialist) were used. For the validation, a psychometric analysis of reliability and validity of the construct was incorporated. The sample in which it was validated was constituted by 205 people with dry eye disease. RESULTS: 141 (69%) of the respondents were women, the mean of age was 48 years ±16,7, and the median of the total score DEQ-5 was 13 points (R.I 8-15 points). The adapted version resulted in a Cronbach alpha of 0.8085, scoring that classified it as good. DISCUSSION: The questionnaire DEQ-5, which was adapted and validated, was a good instrument to be used in populations with similar characteristics of those in the study. More so, the factor analysis enriched comprehension of the way in which people with dry eye disease relate their symptoms and which questions relate more between them, representing in a better way the aspects evaluated of the symptomatology of this disease.

Chemical-analytical characterization and leaching of heavy metals associated with nanoparticles and microplastics from commercial face masks and the abundance of personal protective equipment (PPE) waste in three metropolitan cities of South America.

In this study, we surveyed the presence of personal protective equipment (PPE) waste on the streets of Bogotá-Colombia, Lima-Perú, and Mar del Plata-Argentina. Furthermore, this work is also focused on the release capacity of Ag, Cu, and Zn metals associated with nanoparticles, and microplastics (MPs) from textile face masks (TFMs) and disposable face masks. According to our results, an association between low-income areas and PPE waste was found, which may be related to the periodicity of waste collection and economic activity. Polymers, like polypropylene, cotton-polyester, and additives, such as CaCO3, MgO, and Ag/Cu as nanoparticles, were identified. TFMs released high levels of Cu (35,900-60,200 µg·L-1), Zn (2340-2380 µg·L-1), and MPs (4528-10,640 particles/piece). Metals associated with nanoparticles leached by face masks did not present any antimicrobial activity against P. aeruginosa. Our study suggests that TFMs may leach large amounts of polluting nano/micromaterials in aquatic environments with potential toxicological effects on organisms.

[Clinical follow up and histological findings of patients with MEN2 treated with prophylactic thyroidectomy]. / Hallazgos histológicos y seguimiento clínico de pacientes con MEN 2 tras tiroidectomía profiláctica.

OBJECTIVE: To present our experience in the prophylactic management of the medullary thyroid carcinoma (MTC), reviewing the correlation between clinical, analytical, histopathological, and genetic findings on subjects with type 2A multiple endocrine neoplasia (MEN 2A) and familial MTC. MATERIAL AND METHODS: A retrospective study was done by reviewing the medical records of patients diagnosed with MEN 2A or familial MTC, between 1997 and 2011. The variables studied were sex, age at the time of diagnosis, age at the time of surgery, pre and post operative Calcitonin levels, pre and post op Metanephrine levels in patients with MEN 2A, histopathological findings, follow up and overall survival. RESULTS: Thirteen patients were identified with family history of MTC, 9 females and 4 males. Eleven carriers of mutation on RET proto-oncongene for MEN 2A and no carriers for Familial MTC. The median age at the time of diagnosis was 4.2 years (range: 1.8 to 8.2). All patients were treated with total thyroidectomy, with a median age of 6 years (range: 4.08 to 8.5). The histopathological findings demonstrated 7 cases of C-Cells nodular hyperplasia, 2 micro-carcinomas, 1 multicentric carcinoma, 1 lymphocytic thyroiditis and 2 without evidence of disease. Elevated pre operative Calcitonin levels were found in 3 cases, correlated with one histopathological finding of micro-carcinoma. All patients are disease free. CONCLUSION: In patients with genetic predisposition to suffer the disease, early prophylactic thyroidectomy is the only current available approach to prevent and cure MTC. The creation of a multidisciplinary team (Endocrinology, clinical genetics, and pediatric surgery), is necessary to study, manage and follow up patients with MEN 2A and their families.

[Urethroplasty with lateral pedunculated flap for complicated hypospadias]. / Uretroplastia con colgajo lateral pediculado para las hipospadias complicadas.

UNLABELLED: With the modern techniques, we can resolve almost the totallity of hypospadias. But there are patients with recurrent fistulas associated to uretral stenosis that can finish all the surgical possibilities. MATERIAL AND METHODS: Retrospective review. Lateral based flap uretroplasty consists in the exposition of the uretra, to reconstruct in one-stage the original neourethra with the lateral skin of the penis. RESULTS: From 2008, we have correct 5 patients with a mean age of 12,1 years (9-15) and a weight of 55,34 kg (22-98 kg). All of them were previously corrected 3 to 7 times, with recurrent fistulas. At the office, stenosis urethral was verified. Surgical correction was made in 90-110 minutes and results were positive in all patients, correcting the stenosis after a follow-up of more than a year. Only the oldest two patients had present minimally glans fistula. CONCLUSIONS: Lateral based flap urethroplasty is a useful technique for the correction of the complicated fistulas, allowing the correction of the fistulas and the stenosis of the urethra.

The sensitivity of tropical leaf litter decomposition to temperature: results from a large-scale leaf translocation experiment along an elevation gradient in Peruvian forests.

• We present the results from a litter translocation experiment along a 2800-m elevation gradient in Peruvian tropical forests. The understanding of the environmental factors controlling litter decomposition is important in the description of the carbon and nutrient cycles of tropical ecosystems, and in predicting their response to long-term increases in temperature. • Samples of litter from 15 species were transplanted across all five sites in the study, and decomposition was tracked over 448 d. • Species' type had a large influence on the decomposition rate (k), most probably through its influence on leaf quality and morphology. When samples were pooled across species and elevations, soil temperature explained 95% of the variation in the decomposition rate, but no direct relationship was observed with either soil moisture or rainfall. The sensitivity of the decay rate to temperature (κ(T)) varied seven-fold across species, between 0.024 and 0.169 °C⁻¹, with a mean value of 0.118 ± 0.009 °C⁻¹ (SE). This is equivalent to a temperature sensitivity parameter (Q10) for litter decay of 3.06 ± 0.28, higher than that frequently assumed for heterotrophic processes. • Our results suggest that the warming of approx. 0.9 °C experienced in the region in recent decades may have increased decomposition and nutrient mineralization rates by c. 10%.

Hydrogen electrocatalysis on overlayers of rhodium over gold and palladium substrates--more active than platinum?

We have investigated the stability and catalytic activity of epitaxial overlayers of rhodium on Au(111) and Pd(111). Both surfaces show a strong affinity for hydrogen. We have calculated the energy of adsorption both for a strongly and a more weakly adsorbed species; the latter is the intermediate in the hydrogen evolution reaction. Both the energy of activation for hydrogen adsorption (Volmer reaction) and hydrogen recombination (Tafel reaction) are very low, suggesting that these overlayers are excellent catalysts.

Production of bacterial cellulose tubes for biomedical applications: Analysis of the effect of fermentation time on selected properties.

Biosynthesis of bacterial cellulose (BC) in cylindrical oxygen permeable molds allows the production of hollow tubular structures of increasing interest for biomedical applications (artificial blood vessels, ureters, urethra, trachea, esophagus, etc.). In the current contribution a simple set-up is used to obtain BC tubes of predefined dimensions; and the effects of fermentation time on the water holding capacity, nanofibrils network architecture, specific surface area, chemical purity, thermal stability, mechanical properties, and cell adhesion, proliferation and migration of BC tubes are systematically analysed for the first time. The results reported highlight the role of culture time on key properties of the BC tubes produced, with significant differences arising from the denser and more compact fibril arrangements generated at longer fermentation intervals.

[PHACES syndrome]. / Síndrome de PHACES.

INTRODUCTION: PHACES syndrome associates a segmental facial hemangioma with cerebral malformations, aortic branches/cranial arteries anomalies, cardiac defects, eye anomalies or ventral wall defects. The aim of this study is to analyze our experience with this syndrome. MATERIAL AND METHODS: Retrospective study of the cases seen at our unit in the last year. RESULTS: We treat 4 cases; 3 girls and 1 child. Besides the segmental hemangioma they presented: 3 vascular cerebral malformations; 2 structural cardiopathies; 2 cerebral malformations, 1 microftalmia. We did not find ventral wall defects. A case received treatment with two cycles of metilprednisolone i.v. and oral prednisone, with favourable course; two cases received initial treatment with oral prednisone continued of oral propanolol in rising pattern up to 2 mg/kg/day, Obtaining both the detention of the tumour growth and regression of the lesion, with very good tolerance. A 7-year-old patient has been treated with colouring pulse laser for her residual lesions. CONCLUSIONS: When we see a segmental facial hemangioma we must perform a wide diagnostic study in order to discard a PHACES syndrome. Multidisciplinar approach to the patient by a wide expert's group gets an earlier diagnose and improves the outcome. Propranolol is a promising therapeutic alternative.

[Regional cerebral blood flow changes in Parkinson's disease: correlation with disease duration]. / Cambios de la perfusión cerebral en la enfermedad de Parkinson: relación con la duración de los síntomas.

INTRODUCTION: Changes in regional cerebral blood flow (rCBF) have been reported in idiopathic Parkinson's disease (PD). Nonetheless, their typical pattern still remains controversial regarding some features, such as basal ganglia involvement and the main cortical regions affected. Functional neuroimaging makes it possible to identify the brain dysfunctions of the neural circuits underlying the disease. Voxel-based analysis methods make it possible to increase the reliability of the results. OBJECTIVE: To assess the rCBF changes in patients with PD and their relation with disease duration. MATERIALS AND METHODS: Thirty PD adult patients without dementia underwent evaluation with (99m)Tc-ECD SPECT. SPM5 was used for statistical comparison with 25 normal controls of similar ages. The disease course duration in years was added as a covariate. Additionally, patients with a 6-year evolution or less and those with more than 6 years were compared separately with normal controls. RESULTS: Significant hypoperfusion was detected in bilateral premotor and posterior parietal cortex and increase of perfusion was present in the cerebellum. These changes correlated with the years of evolution of the illness. Patients with longer evolution also presented thalamic, subthalamic and basal ganglia hypoperfusion. CONCLUSIONS: We describe rCBF changes in PD in neural circuits related with control of movements. These changes are more manifest in patients with a longer duration of the disease.

[Surgical management of bilateral Wilms' tumor: our experience with 18 cases]. / Manejo quirúrgico del tumor de Wilms bilateral: nuestra experiencia con 18 casos.

AIM: To show our experience in the surgical management of bilateral Wilms' tumor. METHODS: We have reviewed the medical records of 18 patients diagnosed of bilateral Wilms' tumor between 1971 and 2007, evaluating age, sex, clinical situation, imaging studies, histology, treatment, complications and follow-up. RESULTS: 65% of patients with synchronous Wilms' tumor was stage I-II, 30% stage III and 5% stage IV. 100% of patients with metachronous Wilms' tumor was stage I-II. All the tumors had favourable histology. Surgical complications were: 4 bowel pseudobstructions, 2 ureteropielic fistulae and 1 urinary cyst. 15 patients are alive (83%) with a mean follow-up of 12 years. 3 of these patients had a renal trasplant with a good evolution. One patient died of a progressive renal failure and two patients died of the evolution of the oncological disease. CONCLUSIONS: Preoperative chemotherapy allows a conservative surgical resection with a high overall survival (80-90%). Individualized surgical treatment offers a conservative surgical resection with a lower incidence of long-term renal failure.

[Fast track antibiotic protocol in acute appendicitis]. / Protocolo antibiótico "fast-track" en la apendicitis aguda.

INTRODUCTION: The increase of antimicrobial resistances, has affected the efficacy of antimicrobial triple therapy, increasing appendicitis morbidity. We decided to change to a fast-track protocol of 72 hours of Cefuroxime-Metronidazol or Ertapenem. AIM: to know if our infectious morbidity rate has improved and if early dischargement is possible. MATERIAL AND METHODS: Analytic historic cohort study: Historical cohort (HC): patients intervened of appendicitis between October 2005 and October 2006. Current cohort (CC): started in June 2007. A data collection protocol is designed for both groups. Homogeneity among cohorts is proved and data are analysed (a=0,05). Statistics are analyzed by SPSS 15.0. RESULTS: 226 patients were controlled, being 110 complicated appendicitis (HC: 61/135; AC: 49/91). There are no differences among cohorts about evolution time, temperature and leukocytes rate at admission, interval to intervention, use of laparoscopy, drainage or antimicrobial prophylaxis. There is difference about the use of pre-surgical ultrasound. Admission rate has been reduced in 2.82 days, from 8.41 days in HC to 5.58 with the new antimicrobial protocol (median 7 to 4). The relative risk of developing intraabdominal abscess is 0.366 (HC: 15.7%; CC: 6.4%) (p=0.145) and readmission rate has been reduced from 9.8% to 0% (p=0.028). In 33% of cultures we have found different levels of antimicrobial resistance. No Enterococcus has been isolated. CONCLUSIONS: 1) Infectious morbidity rate has decreased with the new therapy. 2) Antimicrobial resistance and new antibiotics have exceeded Triple antimicrobial therapy. 3) It is possible an early dischargement in perforated appendicitis without an increasing of readmission rate. 4) We must know the bacterial flora in order to adapt our antibiotic therapy.

2-D assembly of supramolecular nanoarchitectures on Mg(0001).

In this work, a Mg(0001) single crystal is used as a novel template to grow 2D supramolecular nano-architectures. By using scanning tunnelling microscopy (STM) and high-resolution X-ray photoemission spectroscopy (HR-XPS), the formation of either a homo-molecular or metal-organic network is reported for carboxylic or amino functionalized molecules, respectively.

Dry eye is matched by increased intrasubject variability in tear osmolarity as confirmed by machine learning approach. / El ojo seco está relacionado con un aumento intrasujeto de la variabilidad de osmolaridad lagrimal confirmado por tecnología de aprendizaje de máquinas.

OBJECTIVE: Because of high variability, tear film osmolarity measures have been questioned in dry eye assessment. Understanding the origin of such variability would aid data interpretation. This study aims to evaluate osmolarity variability in a clinical setting. MATERIAL AND METHODS: Twenty dry eyes and 20 control patients were evaluated. Three consecutive osmolarity measurements per eye at 5min intervals were obtained. Variability was represented by the difference between both extreme readings per eye. Machine learning techniques were used to quantify discrimination capacity of tear osmolarity for dry eye. RESULTS: Mean osmolarities in the control and dry eye groups were 295.1±7.3mOsm/L and 300.6±11.2mOsm/L, respectively (P=.004). Osmolarity variabilities were 7.5±3.6mOsm/L and 16.7±11.9mOsm/L, for the control and dry eye groups, respectively (P<.001). Based on osmolarity, a logistic classifier showed an 85% classification accuracy. CONCLUSIONS: In the clinical setting, both mean osmolarity and osmolarity variability in the dry eye group were significantly higher than in the control group. Machine learning techniques showed good classification accuracy. It is concluded that higher variability of tear osmolarity is a dry eye feature.

TH17 cells express ST2 and are controlled by the alarmin IL-33 in the small intestine.

TH17 cells are major drivers of inflammation and involved in several autoimmune diseases. Tissue inflammation is a beneficial host response to infection, but it can also contribute to autoimmunity. The crosstalk between a tissue and the immune system during an inflammatory response is key for preserving tissue integrity and restoring physiological processes. However, how the inflamed tissue regulates the magnitude of an immune response by controlling pro-inflammatory T cells is not well characterized so far. Here we show that TH17 cells accumulating in the small intestine upon inflammation express the IL-33 receptor (ST2) and intestinal epithelial cells (IEC) are the main source of the alarmin interleukin-33 (IL-33). We show that pro-inflammatory TH17 cells acquire a regulatory phenotype with immunosuppressive properties in response to IL-33. Absence of ST2 signaling promotes the secretion of pro-inflammatory cytokines by TH17 cells and dampens the secretion of IL-10. Our results provide new insights into the mechanisms by which IEC, via IL-33/ST2 axis, may control pro-inflammatory TH17 cells in the small intestine to sustain homeostasis.

Sensory defensiveness: a theory of its effect on breastfeeding.

This article describes one type of sensory integrative disorder: sensory defensiveness. An examination of the possible relationship of this disorder to an infant's difficulties with breastfeeding is conducted. A family case study is detailed, followed by treatments implemented by the authors. Possible long-term sequelae, as well as the need for more interdisciplinary research, are discussed.