Real-time observation of non-equilibrium liquid condensate confined at tensile crack tips in oxide glasses

Since crack propagation in oxide materials at low crack velocities is partly determined by chemical corrosion, proper knowledge of the crack tip chemistry is crucial for understanding fracture in these materials. Such knowledge can be obtained only from in situ studies because the processes that occur in the highly confined environment of the crack tip are very different from those that take place at free surfaces, or that can be traced post mortem. We report the occurrence of hydrous liquid condensate between the two fracture surfaces in the vicinity of the tip of tensile cracks in silica. Observations are performed in real-time by means of atomic force microscopy (AFM) at continuously controlled crack velocities in the regime of stress corrosion. Condensate formation and changes in extent and shape are demonstrated for a wide range of macroscopic humidity at different crack speeds. Its liquid character is confirmed by the study of AFM phase-contrast data. It is believed that this evidence of a nanoscale liquid hydrous phase at the crack tip will enable novel insights in the chemistry of failure of oxide materials.Comment: 13 pages, 4 figures, to be published on J. Am. Cer. So

Ultrasonographic evaluation of the thyroid, determination of ioduria and iodine concentration in kitchen salt used by schoolchildren in Ribeirão Preto, São Paulo, Brazil

OBJETIVO E MÉTODOS: Estudos prévios apontaram Ribeirão Preto, São Paulo, como área de carência limítrofe de iodo e, posteriormente, de iodação excessiva. Reavaliando seu estado iódico em 2007-2008, foram analisados 300 escolares entre 8 e 10 anos de idade, procedentes de três escolas de diferentes níveis socioeconômicos e realizadas dosagens de iodo urinário e da concentração de iodo no sal doméstico e ultrassonografia tireoidiana. RESULTADOS E CONCLUSÃO: A iodúria foi superior na escola com maior nível socioeconômico, comparada às outras, e a diferença foi significante aos 8 e 10 anos para os meninos (p < 0,0001 e p = 0,0106, respectivamente) e aos 8 e 9 anos para as meninas (p = 0,0024 e p = 0,0154, respectivamente). As concentrações medianas de iodo em amostras de sal doméstico variaram entre 26,6 e 27,8 mg iodo/kg e não foram diferentes nas escolas estudadas. À ultrassonografia, 15,6% das tireoides examinadas apresentaram-se hipoecoicas, sugerindo que elas possam apresentar mudanças em sua arquitetura sem ainda alterar seus volumes.OBJECTIVE AND METHODS: Previous studies have pointed out that Ribeirão Preto, São Paulo, is an area of borderline iodine deficiency, later becoming a region of excessive iodination. In a reevaluation of the iodine status of the city in 2007-2008, 300 schoolchildren aged 8 to 10 years were evaluated, from 3 schools of 3 different socioeconomic levels who were submitted to the determination of iodine concentration in urine samples and in kitchen salt and thyroid ultrasound. RESULTS AND CONCLUSION: Among boys and girls ioduria was higher in the school of highest socioeconomic level compared to the others, with a significant difference in the ages 8 and 10 years for boys with ranges : p < 0,0001 and p = 0,0106, respectively; and in the ages 8 and 9 years for girls with ranges: p = 0,0024 and p = 0,0154, respectively. Median iodine concentrations in samples of kitchen salt ranged from 26.6 to 27.8 mg iodine/kg and did not differ between the schools studied. Ultrasound evaluation revealed that 15,6% of thyroids examined were hypoechoic, suggesting that these glands may present changes in the architecture not reflected yet in their volume

Modulation of BACE1 Activity by Chemically Modified Aptamers

A modified DNA aptamer that binds BACE1, a therapeutic target involved in Alzheimer's disease has been developed. This ssXNA not only tightly binds to BACE1 but also inhibits its protease activity in vitro in the same range as a previously described unmodified aptamer. We report the in vitro selection of functional oligonucleotides incorporating two nucleobase modifications: 5‐chlorouracil and 7‐deazaadenine. The nucleoside analogue 5‐chloro‐2′‐deoxyuridine has already been explored as a replacement for thymidine in a chemically modified genome of a bacterium. Thus, 5‐chlorouracil modification is a good candidate to support genetic transfer in vivo as well as functional activity

Avaliação dos indicadores de saúde em sistemas de produção de leite a pasto conforme o protocolo Welfare Quality® de bem-estar animal.

Países exportadores de alimentos, como o Brasil, precisam desenvolver protocolo de bem-estar animal aplicável aos principais tipos de sistemas de produção de leite encontrados no território nacional. Assim, o objetivo deste trabalho foi aplicar o protocolo Welfare Quality® em rebanhos leiteiros predominantemente a pasto no estado de Minas Gerais e elencar possíveis adequações dos indicadores para as condições tropicais de produção de leite. Foram coletados dados individuais de 413 vacas em lactação amostradas, além de dados gerais do manejo em dez propriedades. Verificou-se que todos os rebanhos apresentaram escores abaixo de 50% nos critérios relacionados ao princípio ?Boa Saúde?. Incidência de parasitoses ?tropicais? além de práticas causadoras de injúria reforçam a necessidade de adequação do protocolo WQ®

Phosphonomethyl Oligonucleotides as Backbone-Modified Artificial Genetic Polymers

Although several synthetic or xenobiotic nucleic acids (XNAs) have been shown to be viable genetic materials in vitro, major hurdles remain for their in vivo applications, particularly orthogonality. The availability of XNAs that do not interact with natural nucleic acids and are not affected by natural DNA processing enzymes, as well as specialized XNA processing enzymes that do not interact with natural nucleic acids, is essential. Here, we report 3′–2′ phosphonomethyl-threosyl nucleic acid (tPhoNA) as a novel XNA genetic material and a prime candidate for in vivo XNA applications. We established routes for the chemical synthesis of phosphonate nucleic acids and phosphorylated monomeric building blocks, and we demonstrated that DNA duplexes were destabilized upon replacement with tPhoNA. We engineered a novel tPhoNA synthetase enzyme and, with a previously reported XNA reverse transcriptase, demonstrated that tPhoNA is a viable genetic material (with an aggregate error rate of approximately 17 × 10–3 per base) compatible with the isolation of functional XNAs. In vivo experiments to test tPhoNA orthogonality showed that the E. coli cellular machinery had only very limited potential to access genetic information in tPhoNA. Our work is the first report of a synthetic genetic material modified in both sugar and phosphate backbone moieties and represents a significant advance in biorthogonality toward the introduction of XNA systems in vivo

Glycophenotypic Alterations Induced by Pteridium aquilinum in Mice Gastric Mucosa: Synergistic Effect with Helicobacter pylori Infection

The bracken fern Pteridium aquilinum is a plant known to be carcinogenic to animals. Epidemiological studies have shown an association between bracken fern exposure and gastric cancer development in humans. The biological effects of exposure to this plant within the gastric carcinogenesis process are not fully understood. In the present work, effects in the gastric mucosa of mice treated with Pteridium aquilinum were evaluated, as well as molecular mechanisms underlying the synergistic role with Helicobacter pylori infection. Our results showed that exposure to Pteridium aquilinum induces histomorphological modifications including increased expression of acidic glycoconjugates in the gastric mucosa. The transcriptome analysis of gastric mucosa showed that upon exposure to Pteridium aquilinum several glycosyltransferase genes were differently expressed, including Galntl4, C1galt1 and St3gal2, that are mainly involved in the biosynthesis of simple mucin-type carbohydrate antigens. Concomitant treatment with Pteridium aquilinum and infection with Helicobacter pylori also resulted in differently expressed glycosyltransferase genes underlying the biosynthesis of terminal sialylated Lewis antigens, including Sialyl-Lewisx. These results disclose the molecular basis for the altered pattern of glycan structures observed in the mice gastric mucosa. The gene transcription alterations and the induced glycophenotypic changes observed in the gastric mucosa contribute for the understanding of the molecular mechanisms underlying the role of Pteridium aquilinum in the gastric carcinogenesis process

Global economic burden of unmet surgical need for appendicitis

Background: There is a substantial gap in provision of adequate surgical care in many low-and middle-income countries. This study aimed to identify the economic burden of unmet surgical need for the common condition of appendicitis. Methods: Data on the incidence of appendicitis from 170 countries and two different approaches were used to estimate numbers of patients who do not receive surgery: as a fixed proportion of the total unmet surgical need per country (approach 1); and based on country income status (approach 2). Indirect costs with current levels of access and local quality, and those if quality were at the standards of high-income countries, were estimated. A human capital approach was applied, focusing on the economic burden resulting from premature death and absenteeism. Results: Excess mortality was 4185 per 100 000 cases of appendicitis using approach 1 and 3448 per 100 000 using approach 2. The economic burden of continuing current levels of access and local quality was US $92 492 million using approach 1 and$73 141 million using approach 2. The economic burden of not providing surgical care to the standards of high-income countries was $95 004 million using approach 1 and$75 666 million using approach 2. The largest share of these costs resulted from premature death (97.7 per cent) and lack of access (97.0 per cent) in contrast to lack of quality. Conclusion: For a comparatively non-complex emergency condition such as appendicitis, increasing access to care should be prioritized. Although improving quality of care should not be neglected, increasing provision of care at current standards could reduce societal costs substantially

Laparoscopy in management of appendicitis in high-, middle-, and low-income countries: a multicenter, prospective, cohort study.

BACKGROUND: Appendicitis is the most common abdominal surgical emergency worldwide. Differences between high- and low-income settings in the availability of laparoscopic appendectomy, alternative management choices, and outcomes are poorly described. The aim was to identify variation in surgical management and outcomes of appendicitis within low-, middle-, and high-Human Development Index (HDI) countries worldwide. METHODS: This is a multicenter, international prospective cohort study. Consecutive sampling of patients undergoing emergency appendectomy over 6 months was conducted. Follow-up lasted 30 days. RESULTS: 4546 patients from 52 countries underwent appendectomy (2499 high-, 1540 middle-, and 507 low-HDI groups). Surgical site infection (SSI) rates were higher in low-HDI (OR 2.57, 95% CI 1.33-4.99, p = 0.005) but not middle-HDI countries (OR 1.38, 95% CI 0.76-2.52, p = 0.291), compared with high-HDI countries after adjustment. A laparoscopic approach was common in high-HDI countries (1693/2499, 67.7%), but infrequent in low-HDI (41/507, 8.1%) and middle-HDI (132/1540, 8.6%) groups. After accounting for case-mix, laparoscopy was still associated with fewer overall complications (OR 0.55, 95% CI 0.42-0.71, p < 0.001) and SSIs (OR 0.22, 95% CI 0.14-0.33, p < 0.001). In propensity-score matched groups within low-/middle-HDI countries, laparoscopy was still associated with fewer overall complications (OR 0.23 95% CI 0.11-0.44) and SSI (OR 0.21 95% CI 0.09-0.45). CONCLUSION: A laparoscopic approach is associated with better outcomes and availability appears to differ by country HDI. Despite the profound clinical, operational, and financial barriers to its widespread introduction, laparoscopy could significantly improve outcomes for patients in low-resource environments. TRIAL REGISTRATION: NCT02179112