Poorly differentiated clusters (PDC) in colorectal cancer: what is and ought to be known.

BACKGROUND: The counting of poorly differentiated clusters of 5 or more cancer cells lacking a gland-like structure in a tumor mass has recently been identified among the histological features predictive of poor prognosis in colorectal cancer. MAIN BODY: Poorly differentiated clusters can easily be recognized in the histological sections of colorectal cancer routinely stained with haematoxylin and eosin. Despite some limitations related to specimen fragmentation, counting can also be assessed in endoscopic biopsies. Based on the number of poorly differentiated clusters that appear under a microscopic field of a ×20 objective lens (i.e., a microscopic field with a major axis of 1 mm), colorectal cancer can be graded into malignancies as follows: tumors with <5 clusters as grade 1, tumors with 5 to 9 clusters as grade 2, and tumors with ≥10 clusters as grade 3. High poorly differentiated cluster counts are significantly associated with peri-neural and lympho-vascular invasion, the presence of nodal metastases or micrometastases, as well as shorter overall and progression free survival to colorectal cancer. CONCLUSION: The morphological aspects and clinical relevance of poorly differentiated clusters counting in colorectal cancer are discussed in this review.

El desarrollo personal y profesional mediante el aprendizaje reflexivo : una experiencia en el grado de Educación Social

In the last years, an increase of the interest to develop educational practices in higher education, based on the approach of the reflective learning, is observed. Nevertheless, we scarcely find in our context researches or experiences that allow knowing students’ perceptions about this teaching and learning approach. We have developed an experience in the bachelor of Social Education at the University of Girona with the aim to contribute to the personal and professional development of future social educators in their initial training, using reflective learning methodology. In this article we present an evaluation of the experience based on students’ perceptions. They assessed the usefulness they think the module has for their training, the methodology and the activities. This evaluation has been carried out through in-depth interviews to 17 students who participated in the module in 2010-11 academic year. The results show that students assess positively the experience, either its general usefulness or the methodology of reflective learning, although they acknowledge some difficulties to carry out such a process which involves a high degree of introspection and a difficulty to set the boundaries in the narration of personal questions. The study also shows some challenges related on the need, but also the difficulty, to include personal and professional development as a powerful axis in the higher education curriculum, as well as elements linked to reflective learning assessment

Els altres parlants i la història social de la llengua

The social history of language is usually focused on collective actors. This article aims to reflect both on the speakers as individual subjects of the social history of language and on the sources which allow an approach to speakers, more precisely immigrants of the contemporary Catalonia. In very different narratives, immigrants talk about their territory of origin or economic conditions, and also about languages expressing the most varied language attitudes. Prejudices or language uses, common topics of these narratives, are fully within the field of social history of the language. Speakers cannot be always out of disciplines whose narrative axis is the time

Rotational assessment of distal femur and its relevance in total knee arthroplasty: analysis by magnetic resonance imaging

AbstractObjective:To define the distal femur rotation pattern in a Brazilian population, correlating such pattern with the one suggested by the arthroplasty instruments, and analyzing the variability of each anatomic parameter.Materials and Methods:A series of 101 magnetic resonance imaging studies were evaluated in the period between April and June 2012. The epidemiological data collection was performed with the aid of the institution's computed imaging system, and the sample included 52 male and 49 female patients. The measurements were made in the axial plane, with subsequent correlation and triangulation with the other plans. The posterior condylar line was used as a reference for angle measurements. Subsequently, the anatomical and surgical transepicondylar axes and the anteroposterior trochlear line were specified. The angles between the reference line and the studied lines were calculated with the aid of the institution's software.Results:The mean angle between the anatomical transepicondylar axis and the posterior condylar line was found to be 6.89°, ranging from 0.25° to 12°. For the surgical transepicondylar axis, the mean value was 2.89°, ranging from –2.23° (internal rotation) to 7.86°, and for the axis perpendicular to the anteroposterior trochlear line, the mean value was 4.77°, ranging from –2.09° to 12.2°.Conclusion:The anatomical transepicondylar angle showed mean values corresponding to the measurement observed in the Caucasian population. The utilized instruments are appropriate, but no anatomical parameter proved to be steady enough to be used in isolation.

Nanoantenna enhanced emission of lightharvesting complex 2: the role of resonance, polarization, and radiative and non-radiative rates

Nanoantennae show potential for photosynthesis research for two reasons; first by spatially confining light for experiments which require high spatial resolution, and second by enhancing the photon emission of single light-harvesting complexes. For effective use of nanoantennae a detailed understanding of the interaction between the nanoantenna and the light-harvesting complex is required. Here we report how the excitation and emission of multiple purple bacterial LH2s (light-harvesting complex 2) are controlled by single gold nanorod antennae. LH2 complexes were chemically attached to such antennae, and the antenna length was systematically varied to tune the resonance with respect to the LH2 absorption and emission. There are three main findings. (i) The polarization of the LH2 emission is fully controlled by the resonant nanoantenna. (ii) The largest fluorescence enhancement, of 23 times, is reached for excitation with light at λ = 850 nm, polarized along the long antenna-axis of the resonant antenna. The excitation enhancement is found to be 6 times, while the emission efficiency is increased 3.6 times. (iii) The fluorescence lifetime of LH2 depends strongly on the antenna length, with shortest lifetimes of [similar]40 ps for the resonant antenna. The lifetime shortening arises from an 11 times resonant enhancement of the radiative rate, together with a 2–3 times increase of the non-radiative rate, compared to the off-resonant antenna. The observed length dependence of radiative and non-radiative rate enhancement is in good agreement with simulations. Overall this work gives a complete picture of how the excitation and emission of multi-pigment light-harvesting complexes are influenced by a dipole nanoantenna.

IMP2 provides an alternative to LIN28B for LET-7 target gene protection and glioma stem cell maintenance

Glioblastoma multiforme (GBM) is the most frequent and lethal primary brain tumor in adults. Accumulating evidence suggests that tumors comprise a hierarchical organization that is, at least partially, not genetically driven. Cells that reside at the apex of this hierarchy are commonly referred to as cancer stem cells (CSCs) and are believed to largely contribute to recurrence and therapeutic failure. Although the complexity of epigenetic regulation of the genome precludes prediction as to which epigenetic changes dominate CSC specification in different cancer types, the ability of microRNAs (miRNAs) to fine-tune expression of entire gene networks places them among prime candidates for establishing CSC properties. In this study we characterized the miRNA expression profile of primary GBM grown either under conditions that enrich for GSCs or their differentiated non-tumorigenic progeny (DGCs). Although, we identified a subset of miRNAs that was strongly differentially expressed between GSCs and DGCs, we observed that in GSCs both let-7 and, paradoxically, their target genes are highly expressed, suggesting protection against let-7 action. Using PAR-CLIP we show that insulin-like growth factor-2 mRNA-binding protein 2 (IMP2) provides a mechanism for let-7 target gene protection that represents an alternative to LIN28A/B, which abrogates let-7 biogenesis in normal embryonic and certain malignant stem cells. By direct binding to miRNA recognition elements, IMP2 protects its targets from let-7 mediated decay. Importantly, depletion of IMP2 in GSCs strongly impairs their self- renewal properties and tumorigenicity in vivo, a phenotype that can be rescued by expression of LIN28B, suggesting that IMP2 mainly contributes to GSC maintenance by protecting let-7 target genes from silencing. Using mouse models, we show that depletion of IMP2 in neural stem cells (NSCs) induces let-7 target gene down-regulation, impairs their clonogenic capacity, and affects differentiation. Taken together, our observations describe a novel regulatory function of IMP2 in the let-7 axis whereby it supports GSC and NSC specification. Résumé (Français) Le glioblastome (GBM) est la tumeur primaire maligne du cerveau la plus fréquente. De nombreuses études ont démontré l'existence d'une organisation hiérarchique des cellules cancéreuses liée à des mécanismes épigénétiques. Les cellules qui se trouvent au sommet de cette hiérarchie sont appelées cellules souches cancéreuses (CSC), et contribuent à l'échec thérapeutique. Bien que la complexité des régulateurs épigénétiques permette difficilement de prédire quel mécanisme contribue le plus aux propriétés des CSC, la capacité des microRNAs (miRNAs) de réguler des réseaux entiers de gènes, les placent comme des candidats de premiers choix. Ici, nous avons caractérisé le profil d'expression des miRNAs dans des tumeurs primaires de GBM cultivées dans des conditions qui enrichissent soit pour les CSC, soit pour leur contrepartie de cellules cancéreuses différences (CCD). De manière surprenante et paradoxale la famille de miRNA let-7 et leurs gènes cibles étaient hautement exprimés dans les CSC, suggérant un mécanisme de protection contre l'action des let-7. Avec l'aide de la technologie PAR-CLIP, nous démontrons que la protéine IMP2, protège les mRNAs de l'action des let-7 et représente une alternative à Lin28A/B, qui d'ordinaire réprime fortement la maturation des let-7 dans les cellules souches embryonnaires et divers cancers. En se liant à la région ciblée par les let-7, IMP2 protège ses transcrits de l'action de cette classe de microRNA qui est tumoro-supressive. La déplétion d'IMP2 dans des CSC de GBM réduit fortement leur clonogénicité in vitro et leur tumorigénicité in vivo. Ceci peut être reversé en introduisant Lin28B dans des CSC de GBM, suggérant qu'IMP2 exerce ses fonctions pro-tumorigéniques en modulant l'axe let-7. Avec l'aide de modèles murins, nous observons que la déplétion de IMP2 dans les cellules souches neurales (CSN) induit une baisse de leur clonogénicité et des cibles des miRNAs let-7, suggérant une conservation de ce mécanisme entre les CSC de GBM et les CSN. En résumé, nos observations définissent une nouvelle fonction de IMP2 dans l'axe let-7 par lequel il contribue au maintien des propriétés des CSC et des CSN.

Currículo de licenciatura em química da universidade de brasília: uma proposta em implantação

This article presents the conception, principles and academic structure of the evening course leading to the formation of a Licentiate in Chemistry, at the University of Brasília. The curriculum has been carried out since the beginning of 1993. This curriculum has as its basic axis the graduation of future teachers integrated with the conceptual formation in Chemistry. Interdisciplinary actions are planned between the Chemistry Department, the Psychology Institute and the Faculty of Education so as to provide mechanisms which would allow the licenciate to acquire teaching experience along the course.

Experimental implementation of tightly focused beams with unpolarized transversal component at any plane

The aim of this paper is to provide a formal framework for designing highly focused fields with specific transversal features when the incoming beam is partially polarized. More specifically, we develop a field with a transversal component that remains unpolarized in the focal area. Moreover, its longitudinal component exhibits non-zero values on axis. Special attention is paid to the design of the input beam and the development of the experiment. The implementation of such fields is possible by using an interferometric setup combined with the use of digital holography techniques. Experimental results are compared with those obtained numerically.

Íon Be H+ em campo elétrico uniforme intenso

The influence of a strong external electric field in chemical bonding is not extensively studied. In this work, the behavior of the potential energy curves of the BeH+ ion in an external electric field is investigated by means of variational calculations using molecular orbitals. For simplicity we consider the case where the external field is parallel to the molecular axis, in the direction of the dipole moment, which raises the polarization of the ion. The effects on dissociation are investigated.

Kolmen vapausasteen akseliston ohjaaminen mikroprosessorilla

Diplomityön tavoitteena on tehdä lasertyöasemalle liikkuva kolmen vapausasteen akselisto liikuttamaan laser-laitteiston skanneripäätä. Liikkeen tarkkuus ja tarkka toistettavuus ovat tärkeitä. Moottoreiden liikkeen nopeus sekä kiihdytys- ja jarrutusparametrien täytyy olla määriteltävissä jokaiselle moottorille erikseen. Kolmen vapausasteen akselisto muodostetaan käyttäen kolmea askelmoottoria ja lineaarivaihteistoa. Akselisto liikkuu vaaka-, pysty-, ja syvyyssuunnassa. Työssä kehitetään C-kielinen ohjelma käytettävälle prosessorille ja suunnitellaan ohjainkortti lopullista prototyyppiä varten. Moottoreiden ohjaus ja hallinta toteutetaan AT91S256-prosessorilla, jota ohjataan tietokoneen avulla RS-232 -väylää käyttäen. Vaatimuksena on myös mahdollisuus ohjata askelmoottorin sijasta servomoottoreita samalla ohjelmalla. Tietokoneen käyttöliittymä suunnitellaan erikseen.

Further insights in trichothiodistrophy: a clinical, microscopic, and ultrastructural study of 20 cases and literature review

Background: Trichothiodistrophy (TTD) is a rare autosomal recessive condition that is characterized by a specific congenital hair shaft dysplasia caused by deficiency of sulfur associated with a wide spectrum of multisystem abnormalities. In this article, we study clinical, microscopic, and ultrastructural findings of 20 patients with TTD with the aim to add further insights regarding to this rare condition. Additionally, analyses of our results are compared with those extracted from the literature in order to enhance its comprehensibility. Materials and Methods: Twenty cases of TTD were included: 7 from Mexico and 14 from Spain. Clinical, microscopic, scanning electron microscopy (SEM) studies and X-ray microanalysis (XrMa) were carried out in all of them. Genetic studies were performed in all seven Mexican cases. Patients with xeroderma pigmentosum and xeroderma pigmentosum/TTD-complex were excluded. Results: Cuticular changes and longitudinal crests of the hair shaft were demonstrated. These crests were irregular, disorganized, following the hair longest axis. Hair shaft sulfur deficiency was disposed discontinuously and intermittently rather than uniformly. This severe decrease of sulfur contents was located close to the trichoschisis areas. Only five patients did not show related disturbances. Micro-dolichocephaly was observed in five cases and represented the most frequent facial dysmorphism found. It is also remarkable that all patients with urologic malformations also combined diverse neurologic disorders. Moreover, three Mexican sisters demonstrated the coexistence of scarce pubic vellus hair, developmental delay, onychodystrophy, and maxillar/mandibullar hypoplasia. Conclusions: TTD phenotype has greatly varied from very subtle forms to severe alterations such as neurologic abnormalities, blindness, lamellar ichthyosis and gonadal malformations. Herein, a multisystem study should be performed mandatorily in patients diagnosed with TTD.

Further insights in trichothiodistrophy: a clinical, microscopic, and ultrastructural study of 20 cases and literature review

Background: Trichothiodistrophy (TTD) is a rare autosomal recessive condition that is characterized by a specific congenital hair shaft dysplasia caused by deficiency of sulfur associated with a wide spectrum of multisystem abnormalities. In this article, we study clinical, microscopic, and ultrastructural findings of 20 patients with TTD with the aim to add further insights regarding to this rare condition. Additionally, analyses of our results are compared with those extracted from the literature in order to enhance its comprehensibility. Materials and Methods: Twenty cases of TTD were included: 7 from Mexico and 14 from Spain. Clinical, microscopic, scanning electron microscopy (SEM) studies and X-ray microanalysis (XrMa) were carried out in all of them. Genetic studies were performed in all seven Mexican cases. Patients with xeroderma pigmentosum and xeroderma pigmentosum/TTD-complex were excluded. Results: Cuticular changes and longitudinal crests of the hair shaft were demonstrated. These crests were irregular, disorganized, following the hair longest axis. Hair shaft sulfur deficiency was disposed discontinuously and intermittently rather than uniformly. This severe decrease of sulfur contents was located close to the trichoschisis areas. Only five patients did not show related disturbances. Micro-dolichocephaly was observed in five cases and represented the most frequent facial dysmorphism found. It is also remarkable that all patients with urologic malformations also combined diverse neurologic disorders. Moreover, three Mexican sisters demonstrated the coexistence of scarce pubic vellus hair, developmental delay, onychodystrophy, and maxillar/mandibullar hypoplasia. Conclusions: TTD phenotype has greatly varied from very subtle forms to severe alterations such as neurologic abnormalities, blindness, lamellar ichthyosis and gonadal malformations. Herein, a multisystem study should be performed mandatorily in patients diagnosed with TTD.

Control of permanent magnet linear synchronous motor in motion control applications

The aim of the thesis is to study the principles of the permanent magnet linear synchronous motor (PMLSM) and to develop a simulator model of direct force controlled PMLSM. The basic motor model is described by the traditional two-axis equations. The end effects, cogging force and friction model are also included into the final motor model. Direct thrust force control of PMLSM is described and modelled. The full system model is proven by comparison with the data provided by the motor manufacturer.

A formação do Químico

Training of highly qualified personnel is the most transversal axis among those identified in the document "Mobilizing Axes in Chemistry", published by SBQ, in 2002, which demands to deep the discussions, initiated in the symposium "The Chemist's Education", whose main objective was to discuss the repercussions of that training in the teaching and in the industrial section. After the publication of an initial paper, a couple of meetings and workshops held in Rio de Janeiro, in December 2003, involving the national chemist community, discussed the "The role of the graduate degrees in the Chemist's Education" and "The Chemist's Education", and confirmed the need to invest in the formation of qualified human resources in profusion and in all levels. Actions to be taken were delineated. Presently, the graduate programs in Chemistry are showing expressive results. However, although these professionals are mostly absorbed by the academy (the absorption of the industry is less significant), only a few programs give special attention to the didactical and pedagogical training. The regional decentralization is actually a tendency in most programs, but the interaction academy-economic activities is still a challenge. It is necessary to establish with the industrial section, the highly qualified professional's profile in Chemistry that the industry can absorb. The undergraduation is growing in number and quality, however still excessively concentrated in the Southeast area. The national "Curricula Guidelines" for Chemistry Courses, through its flexible approach, propitiate the integral, interdisciplinary (non compartmentalized) and critical-reflexive training of the professionals as citizens and as entrepreneurs. However, deficiencies are still recognized. The evaluation system of undergraduate courses has been able to identify the most fragile modalities of courses and other indicators. It was also verified that Brazilian chemistry industry absorbs minimally the highly qualified professionals, which is attributed to the fact that the Federal Council of Chemistry is vertically organized and does not recognize the graduate degrees as professional qualification. In the conclusion, it stands out, among other aspects, the importance of the effective implantation of the national curricula guidelines, bringing out courses whose didactical and pedagogical projects may offer a solid formation in Chemistry, but comprehensive and general enough to enable the Chemistry professionals to develop varied skills.

Control and femtosecond time-resolved imaging of torsion in a chiral molecule

We study how the combination of long and short laser pulses can be used to induce torsion in an axially chiral biphenyl derivative (3,5-difluoro-3 ,5 -dibromo-4 -cyanobiphenyl). A long, with respect to the molecular rotational periods, elliptically polarized laser pulse produces 3D alignment of the molecules, and a linearly polarized short pulse initiates torsion about the stereogenic axis. The torsional motion is monitored in real-time by measuring the dihedral angle using femtosecond time-resolved Coulomb explosion imaging. Within the first 4 picoseconds (ps), torsion occurs with a period of 1.25 ps and an amplitude of 3◦ in excellent agreement with theoretical calculations. At larger times, the quantum states of the molecules describing the torsional motion dephase and an almost isotropic distribution of the dihedral angle is measured.We demonstrate an original application of covariance analysis of two-dimensional ion images to reveal strong correlations between specific ejected ionic fragments from Coulomb explosion. This technique strengthens our interpretation of the experimental data