Apical access and closure devices for transapical transcatheter heart valve procedures.

The majority of transcatheter aortic valve implantations, structural heart procedures and the newly developed transcatheter mitral valve repair and replacement are traditionally performed either through a transfemoral or a transapical access site, depending on the presence of severe peripheral vascular disease or anatomic limitations. The transapical approach, which carries specific advantages related to its antegrade nature and the short distance between the introduction site and the cardiac target, is traditionally performed through a left anterolateral mini-thoracotomy and requires rib retractors, soft tissue retractors and reinforced apical sutures to secure, at first, the left ventricular apex for the introduction of the stent-valve delivery systems and then to seal the access site at the end of the procedure. However, despite the advent of low-profile apical sheaths and newly designed delivery systems, the apical approach represents a challenge for the surgeon, as it has the risk of apical tear, life-threatening apical bleeding, myocardial damage, coronary damage and infections. Last but not least, the use of large-calibre stent-valve delivery systems and devices through standard mini-thoracotomies compromises any attempt to perform transapical transcatheter structural heart procedures entirely percutaneously, as happens with the transfemoral access site, or via a thoracoscopic or a miniaturised video-assisted percutaneous technique. During the past few years, prototypes of apical access and closure devices for transapical heart valve procedures have been developed and tested to make this standardised successful procedure easier. Some of them represent an important step towards the development of truly percutaneous transcatheter transapical heart valve procedures in the clinical setting.

User Centered Desing in E-Learning Environments : from Usability to Learner Experience

The advent of the Internet had a great impact on distance education and rapidly e-learning has become a killer application. Education institutions worldwide are taking advantage of the available technology in order to facilitate education to a growing audience. Everyday, more and more people use e-learning systems, environments and contents for both training and learning. E-learning promotes educationamong people that due to different reasons could not have access to education: people who could nottravel, people with very little free time, or withdisabilities, etc. As e-learning systems grow and more people are accessing them, it is necessary to consider when designing virtual environments the diverse needs and characteristics that different users have. This allows building systems that people can use easily, efficiently and effectively, where the learning process leads to a good user experience and becomes a good learning experience.

Museos y periodistas. Análisis de la sala de prensa virtual como espacio de relaciones públicas

Las rutinas de producción periodística se vieron alteradas con la aparición de Internet y la evolución de las fuentes 2.0. Se han extendido los espacios virtuales corporativos para los medios de comunicación, entendidos como herramienta básica de Relaciones Públicas. Los responsables de las organizaciones museísticas han entendido la necesidad de establecer un vínculo relacional con los periodistas en la red, a través de los sitios web oficiales de los museos. No obstante, concluimos que no facilitan los contenidos necesarios para transmitirlos de forma apropiada.

Reciclagem de cobre proveniente de analisador automático de carbono e nitrogênio

Isotopic and elemental analysis of N, C and S in liquid and solid samples has been simplified with the advent of automated systems. The simplest method of automation for this kind of analysis involves an elemental analyzer interfaced directly to the ion source of an IRMS (Isotope Ratio Mass Spectrometry). In the analyzer reduction system, an expressive amount of oxidized copper is generated as solid residue. This material is normally imported and the price is very high. A methodology was proposed for the recovery of metallic copper in order to recycle this reagent in the reduction system of a GC-IRMS, using the hydrogen gas in the vacuum line. Results show that it is possible to obtain a recycle of about 95 % of the initial metallic copper used in the reduction system.

Microscopia de força atômica aplicada em imunoensaios

Affinity reactions have been used for specific detection of their complementary partners and an enormous variety of enzyme-linked immunosorbent assay (ELISA) formats are used in research and in routine serological tests. With the advent of the atomic force microscopy (AFM) technique, the immune reactions have been monitored by these devices. In the present article we focus on applications of AFM to immunoassays. After introducing the basic concepts of AFM, a brief discussion on the monitoring of the interactions between antigens and antibodies through both topographic image and biosensor systems is presented.

O centenário da Teoria de Bohr

The year 2013 marks the centennial of that wondrous year in which Niels Bohr proposed a novel theory about the constitution of atoms and small molecules after which the way we regard atoms and their behaviour began to be drastically altered. Bohr drew on several sources for his original description of the atoms, most importantly on spectroscopy and Balmer's equation thereof, the new quantum hypothesis advanced a few years earlier by Planck, and the planetary atom proposed by Rutherford. Although Bohr's ideas were to be eventually overtaken by the advent of quantum mechanics, his theory was the basis of a new thinking about atoms and molecules which constitutes an invaluable asset in the development of science ever since.

Fatos e tendências da biocatálise

Brazil is renowned for its biodiversity; however, its economy is based on exotic plants, extraction and unsustainable use of natural resources. This issue was addressed in a recent QN review entitled "Chemistry without Borders." In order to explore the potential of Brazilian biodiversity fully, sustainable development is required in key technological areas, such as biotechnology. This research field is consistent with the green chemistry and white technology principles. Therefore, biotechnology is a sustainable alternative to conventional technologies and is expected to account for 20% of global chemicals by 2020. Brazil is the second largest grower of biotech crops and biodiesel, but its main activities rely on the fermentative process. In order to stimulate the national biotechnology development, the Brazilian Federal Government launched a national policy for biotechnology in 2007 and the National Committee of Biotechnology was created. Among the outstanding biotechnological processes, biocatalysis is one of the most important alternatives to conventional processing, and this field has changed dramatically with the advent of recombinant DNA technology in the 1970s, when large quantities of enzymes were accessible. The direct evolution methodology in the 1990s was a breakthrough and allowed tailoring of enzymes possessing high stability and stereoselectivity. However, about 60 years after the first industrial enzymatic biotransformation of steroids, the full potential of biocatalysis is far from being achieved. Future challenges in this field concern the multienzyme cascade reactions associated with optimized chemoenzymatic processes, and some recent industrial application of biocatalysts are also highlighted in this perspective.

Kirja kristinuskon tulevaisuudesta kiinnostuneille

Kirjallisuusarvostelu

Sätkynukke ja kääpiö : Slavoj Zizekin perverssi kristilliseksi tuleminen

Kirjallisuusarvostelu

Novel CO2 Regulated Proteins in Synechocystis PCC 6803

The large biodiversity of cyanobacteria together with the increasing genomics and proteomics metadata provide novel information for finding new commercially valuable metabolites. With the advent of global warming, there is growing interest in the processes that results in efficient CO2 capture through the use of photosynthetic microorganisms such as cyanobacteria. This requires a detailed knowledge of how cyanobacteria respond to the ambient CO2. My study was aimed at understanding the changes in the protein profile of the model organism, Synechocystis PCC 6803 towards the varying CO₂ level. In order to achieve this goal I have employed modern proteomics tools such as iTRAQ and DIGE, recombinant DNA techniques to construct different mutants in cyanobacteria and biophysical methods to study the photosynthetic properties. The proteomics study revealed several novel proteins, apart from the well characterized proteins involved in carbon concentrating mechanisms (CCMs), that were upregulated upon shift of the cells from high CO₂ concentration (3%) to that in air level (0.039%). The unknown proteins, Slr0006 and flavodiiron proteins (FDPs) Sll0217-Flv4 and Sll0219-Flv2, were selected for further characterization. Although slr0006 was substantially upregulated under C_i limiting conditions, inactivation of the gene did not result in any visual phenotype under various environmental conditions indicating that this protein is not essential for cell survival. However, quantitative proteomics showed the induction of novel plasmid and chromosome encoded proteins in deltaslr0006 under air level CO₂ conditions. The expression of the slr0006 gene was found to be strictly dependent on active photosynthetic electron transfer. Slr0006 contains conserved dsRNA binding domain that belongs to the Sua5/YrdC/YciO protein family. Structural modelling of Slr0006 showed an alpha/beta twisted open-sheet structure and a positively charged cavity, indicating a possible binding site for RNA. The 3D model and the co-localization of Slr0006 with ribosomal subunits suggest that it might play a role in translation or ribosome biogenesis. On the other hand, deletions in the sll0217-sll218- sll0219 operon resulted in enhanced photodamage of PSII and distorted energy transfer from phycobilisome (PBS) to PSII, suggesting a dynamic photoprotection role of the operon. Constructed homology models also suggest efficient electron transfer in heterodimeric Flv2/Flv4, apparently involved in PSII photoprotection. Both Slr0006 and FDPs exhibited several common features, including negative regulation by NdhR and ambiguous cellular localization when subjected to different concentrations of divalent ions. This strong association with the membranes remained undisturbed even in the presence of detergent or high salt. My finding brings ample information on three novel proteins and their functions towards carbon limitation. Nevertheless, many pathways and related proteins remain unexplored. The comprehensive understanding of the acclimation processes in cyanobacteria towards varying environmental CO₂ levels will help to uncover adaptive mechanisms in other organisms, including higher plants.

Videolaparoscopia no trauma abdominal

Despite the use of laparoscopy in abdominal trauma for several decades, it was only after the advent of video chip camera that an explosion of interest ocurred, giving rise to possibilities and perspectives not only in diagnosis but also in therapeutics. In trauma, its use has been gradually defined and experience has shown the benefits of the method in early diagnosis of visceral injuries as well as avoiding unnecessary laparotomies. Trauma laparoscopy is a safe method, can reduce negative and nontherapeutic laparotomies. The worrisome failure of laparoscopy to detect gastrintestinal injuries, specially small bowel lesions can be avoided with a mandatory and apropriated "run bowel" exploration. We believe that in hemodinamically stable patients, video laparoscopy is safely indicated in some situations in trauma, such as evaluation of diaphragmatic injuries in thoraco abdominal stab wounds and tangential gunshot wounds of anterior abdominal wall.

Tuberculose pancreática

Tuberculosis is an extremely common chronic disease in developing countries, caused by Mycobacterium tuberculosis. The principal target organ is the lung, causing focal necrosis and destruction. In about 12% of cases, extrapulmonary dissemination involving the gastrointestinal system occurs. The pancreas is involved in about 0,25% of all cases of disseminated tuberculosis, but its isolated involvement is a medical curiosity. In the last years, with the advent of AIDS, extrapulmonary dissemination and atypical abdominal presentation has increased. We report a case of pancreatic tuberculosis in a 66-year-old patient, with no previous history of pulmonary tuberculosis or immunocompromised state in whom the diagnosis was made by CT-guided skin needle biopsy. After clinical treatment with current antibiotic therapy, the patient recovered well.

Korkeatasoinen kristinuskon historia tv-sarjana

Tv-ohjelman arvostelu.

The brain decade in debate: VIII. Peptide hormones and behavior: cholecystokinin and prolactin

This article is a transcription of an electronic symposium held on November 28, 2000 in which active researchers were invited by the Brazilian Society of Neuroscience and Behavior (SBNeC) to discuss the advances of the last decade in the peptide field with particular focus on central actions of prolactin and cholecystokinin. The comments in this symposium reflect the diversity of prolactin and cholecystokinin research and demonstrate how the field has matured. Since both peptides play a role in reproductive behaviors, particularly mother-infant interactions, this was the starting point of the discussion. Recent findings on the role of the receptor subtypes as well as interaction with other peptides in this context were also discussed. Another issue discussed was the possible role of these peptides in dopamine-mediated rewarding systems. Both prolactin and cholecystokinin are involved in mechanisms controlling food intake and somatic pain thresholds. The role of peripheral inputs through vagal afferents modulating behavior was stressed. The advent of knockout animals as potential generators of new knowledge in this field was also addressed. Finally, interactions with other neuropeptides and investigation of the role of these peptides in other fields such as immunology were mentioned. Knowledge about the central functions of prolactin and cholecystokinin has shown important advances. The role of these peptides in neurological and psychiatric syndromes such as anorexia, drug abuse and physiological disturbances that lead to a compromised maternal behavior seems relevant.

Transtracheal puncture: a forgotten procedure

Transtracheal puncture has long been known as a safe, low-cost procedure. However, with the advent of bronchoscopy, it has largely been forgotten. Two researchers have suggested the use of α-amylase activity to diagnose salivary aspiration, but the normal values of this enzyme in tracheobronchial secretions are unknown. We aimed to define the normal values of α-amylase activity in tracheobronchial secretions and verify the rate of major complications of transtracheal puncture. From October 2009 to June 2011, we prospectively evaluated 118 patients without clinical or radiological signs of salivary aspiration who underwent transtracheal puncture before bronchoscopy. The patients were sedated with a solution of lidocaine and diazepam until they reached a Ramsay sedation score of 2 or 3. We then cleaned the cervical region and anesthetized the superficial planes with lidocaine. Next, we injected 10 mL of 2% lidocaine into the tracheobronchial tree. Finally, we injected 10 mL of normal saline into the tracheobronchial tree and immediately aspirated the saline with maximum vacuum pressure to collect samples for measurement of the α-amylase level. The α-amylase level mean ± SE, median, and range were 1914 ± 240, 1056, and 24-10,000 IU/L, respectively. No major complications (peripheral desaturation, subcutaneous emphysema, cardiac arrhythmia, or hemoptysis) occurred among 118 patients who underwent this procedure. Transtracheal aspiration is a safe, low-cost procedure. We herein define for the first time the normal α-amylase levels in the tracheobronchial secretions of humans.