447 research outputs found
Ab initio analysis of the x-ray absorption spectrum of the myoglobin-carbon monoxide complex: Structure and vibrations
We present a comparison between Fe K-edge x-ray absorption spectra of
carbonmonoxy-myoglobin and its simulation based on density-functional theory
determination of the structure and vibrations and spectral simulation with
multiple-scattering theory. An excellent comparison is obtained for the main
part of the molecular structure without any structural fitting parameters. The
geometry of the CO ligand is reliably determined using a synergic approach to
data analysis. The methodology underlying this approach is expected to be
especially useful in similar situations in which high-resolution data for
structure and vibrations are available.Comment: 13 pages, 3 figure
Controversies in Surgical Staging of Endometrial Cancer
Endometrial cancer is the most common gynaecological malignancy and its incidence is increasing. In 1998, international federation of gynaecologists and obstetricians (FIGO) required a change from clinical to surgical staging in endometrial cancer, introducing pelvic and paraaortic lymphadenectomy. This staging requirement raised controversies around the importance of determining nodal status and impact of lymphadenectomy on outcomes. There is agreement about the prognostic value of lymphadenectomy, but its extent, therapeutic value, and benefits in terms of survival are still matter of debate, especially in early stages. Accurate preoperative risk stratification can guide to the appropriate type of surgery by selecting patients who benefit of lymphadenectomy. However, available preoperative and intraoperative investigations are not highly accurate methods to detect lymph nodes and a complete surgical staging remains the most precise method to evaluate extrauterine spread of the disease. Laparotomy has always been considered the standard approach for endometrial cancer surgical staging. Traditional and robotic-assisted laparoscopic techniques seem to provide equivalent results in terms of disease-free survival and overall survival compared to laparotomy. These minimally invasive approaches demonstrated additional benefits as shorter hospital stay, less use of pain killers, lower rate of complications and improved quality of life
Good Preservation of Stromal Cells and No Apoptosis in Human Ovarian Tissue after Vitrification
One-Step Laparoscopic Management of a Female Adnexal Tumor of Wolffian Origin
We report a case of female adnexal tumor of Wolffian origin (FATWO), a rare neoplasm arising from the mesonephric ducts. A 48-year-old woman came first to our center for a recent discovery of a pelvic mass. Transvaginal ultrasonographic findings suggested a solid right para-ovarian mass suspected to be malignant. After thorough counseling, the patient underwent operative laparoscopy for excision of the para-ovarian mass with frozen section (FS) examination resulting in the diagnosis of a poorly differentiated adenocarcinoma. In this case, FS results allowed performing a comprehensive oncological staging, through a totally laparoscopic extrafascial hysterectomy, bilateral adnexectomy, total omentectomy, pelvic wall peritonectomy, and pelvic, parasacral and para-aortic lymphadenectomy. Final pathological and immunohistochemical results confirmed the diagnosis of FATWO. To our knowledge, this is the first case of FATWO managed entirely by a minimally invasive laparoscopic approach in a single surgical session
ESPACIOS, TRADICIONES Y CAMBIOS EN CONCHUCOS. Ecos desde la Escuela de etnografía del Proyecto “Antonio Raimondi”, Ancash Perú
Este volumen nace con dos finalidades precisas. La primera, dar a conocer los trabajos de investigación etnográfica que un grupo de nueve estudiantes de la Universidad de Bologna (Italia) y otro de la Pontificia Universidad Católica del Perú han desarrollado en la provincia de Huari, Ancash, Perú, durante seis años, entre 2003 y 2008 en el marco del Proyecto Arqueológico y Antropológico “Antonio Raimondi”. La segunda finalidad es realizar la difusión de las únicas miradas etnográficas que hasta hoy se han producido sobre la región Conchucos.
Otro objetivo, más teórico y más implícito, es desplegar a lo largo del camino de la lectura de los casos etnográficos, una visión processual y dinamista de la escritura etnográfica y de la especulación antropológica, procedente de una manera precisa de hacer trabajo de campo. Los artículos aquí propuestos presentan, mediante varios estilos y diferentes acercamientos, una realidad sociocultural en movimiento, en constante cambio. Construyendo cuadros de varios aspectos sociales, políticos y culturales de la provincia de Huari, los autores delinean un escenario en proceso en el cual diferentes actores, ámbitos y dinámicas socioculturales se interrelacionan, participando de maneras diferents en la transformación
Fauna de Lepidoptera associada a plantas lactíferas do cerrado
Nine lactiferous plants of five families were examined for caterpillars in a 4 ha cerrado sensu stricto (savanna-like vegetation) area of the University of Brasília Experimental Farm (DF, Brazil), from August 1995 to May 1997. In 5,540 censuses, less than 5% of the plants hosted caterpillars. All the caterpillars found, a total of 55 species in 15 families were reared under laboratory conditions. Pyralidae, Geometridae, Elachistidae, Megalopygidae, and Limacodidae were the richest caterpillar families recorded. Of the 55 species, more than 40% were polyphagous, feeding on different host plant families, while 21 were considered rare species with less than four records during the study period. The species' rareness did not permit any analysis of diet breadth. The presence of latex in the host plants seems to affect both the proportion of host plants with caterpillars (abundance) and the caterpillar species richness. The habit of eating plants that characteristically produce latex occurs in several distantly-related lepidopteran families. The results support the argument that specific behaviors to circumvent plant latex defense may have arisen independently many times in the Lepidoptera.Nove espécies de cinco famílias de plantas hospedeiras lactíferas foram examinadas, a procura de lagartas, em uma área de cerca de 4 ha de cerrado sensu stricto na Fazenda Água Limpa da Universidade de Brasília, DF, Brasil, de agosto de 1995 a maio de 1997. Foram realizados 5.540 censos e em menos de 5% das plantas hospedeiras foram encontradas lagartas. Todas as lagartas encontradas foram criadas em condições de laboratório. No laboratório emergiram 55 espécies de 15 famílias de Lepidoptera. As famílias mais comuns foram Pyralidae, Geometridae, Elachistidae, Megalopygidae e Limacodidae. Do total de 55 espécies mais de 40% são certamente polífagas. Entretanto, 21 espécies podem ser consideradas raras com menos de quatro ocorrências, o que impede uma análise de dieta. De um modo geral a presença de látex nas plantas hospedeiras parece afetar a abundância e a riqueza de espécies de Lepidoptera. Espécies de Lepidoptera de famílias distantes filogeneticamente foram encontradas alimentando-se dessas plantas lactíferas, o que corrobora a sugestão de que comportamentos específicos desenvolvidos para alimentar-se de plantas com látex tenham evoluido várias vezes entre os lepidópteros
Therapeutic androgen receptor ligands
In the past several years, the concept of tissue-selective nuclear receptor ligands has emerged. This concept has come to fruition with estrogens, with the successful marketing of drugs such as raloxifene. The discovery of raloxifene and other selective estrogen receptor modulators (SERMs) has raised the possibility of generating selective compounds for other pathways, including androgens (that is, selective androgen receptor modulators, or SARMs)
Multi-Particle Collision Dynamics -- a Particle-Based Mesoscale Simulation Approach to the Hydrodynamics of Complex Fluids
In this review, we describe and analyze a mesoscale simulation method for
fluid flow, which was introduced by Malevanets and Kapral in 1999, and is now
called multi-particle collision dynamics (MPC) or stochastic rotation dynamics
(SRD). The method consists of alternating streaming and collision steps in an
ensemble of point particles. The multi-particle collisions are performed by
grouping particles in collision cells, and mass, momentum, and energy are
locally conserved. This simulation technique captures both full hydrodynamic
interactions and thermal fluctuations. The first part of the review begins with
a description of several widely used MPC algorithms and then discusses
important features of the original SRD algorithm and frequently used
variations. Two complementary approaches for deriving the hydrodynamic
equations and evaluating the transport coefficients are reviewed. It is then
shown how MPC algorithms can be generalized to model non-ideal fluids, and
binary mixtures with a consolute point. The importance of angular-momentum
conservation for systems like phase-separated liquids with different
viscosities is discussed. The second part of the review describes a number of
recent applications of MPC algorithms to study colloid and polymer dynamics,
the behavior of vesicles and cells in hydrodynamic flows, and the dynamics of
viscoelastic fluids
Aptamer-based multiplexed proteomic technology for biomarker discovery
Interrogation of the human proteome in a highly multiplexed and efficient manner remains a coveted and challenging goal in biology. We present a new aptamer-based proteomic technology for biomarker discovery capable of simultaneously measuring thousands of proteins from small sample volumes (15 [mu]L of serum or plasma). Our current assay allows us to measure ~800 proteins with very low limits of detection (1 pM average), 7 logs of overall dynamic range, and 5% average coefficient of variation. This technology is enabled by a new generation of aptamers that contain chemically modified nucleotides, which greatly expand the physicochemical diversity of the large randomized nucleic acid libraries from which the aptamers are selected. Proteins in complex matrices such as plasma are measured with a process that transforms a signature of protein concentrations into a corresponding DNA aptamer concentration signature, which is then quantified with a DNA microarray. In essence, our assay takes advantage of the dual nature of aptamers as both folded binding entities with defined shapes and unique sequences recognizable by specific hybridization probes. To demonstrate the utility of our proteomics biomarker discovery technology, we applied it to a clinical study of chronic kidney disease (CKD). We identified two well known CKD biomarkers as well as an additional 58 potential CKD biomarkers. These results demonstrate the potential utility of our technology to discover unique protein signatures characteristic of various disease states. More generally, we describe a versatile and powerful tool that allows large-scale comparison of proteome profiles among discrete populations. This unbiased and highly multiplexed search engine will enable the discovery of novel biomarkers in a manner that is unencumbered by our incomplete knowledge of biology, thereby helping to advance the next generation of evidence-based medicine
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