198 research outputs found
How does particle size influence caking in lactose powder?
Particle size distribution (PSD) is known to influence product properties such as flowability andcompressibility. When producing crystalline lactose, different steps can affect the PSD of the finalpowder. The aim of this study was to investigate the influence of PSD on caking and the mechanismsinvolved. Smaller particles showed higher moisture sorption and a greater caking tendency, measured bydynamic vapor sorption and ring shear testing, respectively. Therefore, moisture sorption isothermsappeared as a valuable tool to predict the effect of PSD on humidity caking, as confirmed by the results ofring shear testing. Controlling the amount of fines, characterized by a higher content of impurities, alarger specific surface area and a broader span of the PSD, was found critical to limit caking. Moreprecisely, both the total surface area and the span of the PSD require close attention as they cansignificantly influence humidity and mechanical caking
Análise ergonômica do trabalho agrícola familiar na produção de leite.
Este artigo trata da metodologia utilizada em uma intervenção ergonômica sobre organização do trabalho em Unidades de Produção Agrícola Familiar (UPAF) produtoras de leite de origem bovina, na região oeste da França. Apresenta-se a metodologia utilizada, uma combinação de jornadas de observação e análise do trabalho e jornadas de formação-ação. Discutem-se a Crônica de Ação e o Plano de Utilização das Instalações (PUI), bem como a utilização destes no processo de conscientização do agricultor sobre a complexidade de seu trabalho. Apresenta-se a análise da "supervisão do rebanho", devido ao seu alto grau de complexidade e importância para o desempenho da produção de leite, explorando de que forma certos arranjos espaciais podem favorecer as condições para a realização desta tarefa. Na análise do trabalho agrícola familiar privilegia-se o olhar complexo sobre a situação de trabalho, visando identificar os determinantes, as fontes de variabilidade e as estratégias adotadas
Quantification de l'architecture osseuse par microtomographie 3D utilisant le rayonnement synchrotron
Nous présentons un système de microtomographie 3D par rayonnement synchrotron développé à l'ESRF de Grenoble, en vue de l'analyse de la structure trabéculaire osseuse. Ce système permet d'acquérir de façon non destructive des images 3D d'échantillons osseux , ayant des voxels isotrope de 6.65 μm. Afin de caractériser la structure 3D de l'os, des paramètres quantitatifs sont extraits de ces images. Les paramètres morphologiques et topologiques utilisés en histomorphométrie, sont calculés sur les différentes coupes du volume. La variabilité des paramètres dans l'échantillon et la nécessité d'une analyse réellement tridimensionnelle sont soulignés. L'influence de la résolution spatiale sur l'exactitude des paramètres calculés est également examinée
Maintenance of active chromatin states by HMGN2 is required for stem cell identity in a pluripotent stem cell model
Background:
Members of the HMGN protein family modulate chromatin structure and influence epigenetic modifications. HMGN1 and HMGN2 are highly expressed during early development and in the neural stem/progenitor cells of the developing and adult brain. Here, we investigate whether HMGN proteins contribute to the chromatin plasticity and epigenetic regulation that is essential for maintaining pluripotency in stem cells.
Results:
We show that loss of Hmgn1 or Hmgn2 in pluripotent embryonal carcinoma cells leads to increased levels of spontaneous neuronal differentiation. This is accompanied by the loss of pluripotency markers Nanog and Ssea1, and increased expression of the pro-neural transcription factors Neurog1 and Ascl1. Neural stem cells derived from these Hmgn-knockout lines also show increased spontaneous neuronal differentiation and Neurog1 expression. The loss of HMGN2 leads to a global reduction in H3K9 acetylation, and disrupts the profile of H3K4me3, H3K9ac, H3K27ac and H3K122ac at the Nanog and Oct4 loci. At endodermal/mesodermal genes, Hmgn2-knockout cells show a switch from a bivalent to a repressive chromatin configuration. However, at neuronal lineage genes whose expression is increased, no epigenetic changes are observed and their bivalent states are retained following the loss of HMGN2.
Conclusions:
We conclude that HMGN1 and HMGN2 maintain the identity of pluripotent embryonal carcinoma cells by optimising the pluripotency transcription factor network and protecting the cells from precocious differentiation. Our evidence suggests that HMGN2 regulates active and bivalent genes by promoting an epigenetic landscape of active histone modifications at promoters and enhancers
A low-cost HPV immunochromatographic assay to detect high-grade cervical intraepithelial neoplasia
Objective
To evaluate the reproducibility and accuracy of the HPV16/18-E6 test.
Methods
The study population was comprised of 448 women with a previously abnormal Pap who were referred to the Barretos Cancer Hospital (Brazil) for diagnosis and treatment. Two cervical samples were collected immediately before colposcopy, one for the hr-HPV-DNA test and cytology and the other for the HPV16/18-E6 test using high-affinity monoclonal antibodies (mAb). Women with a histologic diagnosis of cervical intraepithelial neoplasia grade 2 or 3 were considered to be positive cases. Different strategies using a combination of screening methods (HPV-DNA) and triage tests (cytology and HPV16/18-E6) were also examined and compared.
Results
The HPV16/18-E6 test exhibited a lower positivity rate compared with the HPV-DNA test (19.0% vs. 29.3%, p<0.001) and a moderate/high agreement (kappa = 0.68, 95% CI: 0.60-0.75). It also exhibited a significantly lower sensitivity for CIN2+ and CIN3+ detection compared to the HPV-DNA test and a significantly higher specificity. The HPV16/18-E6 test was no different from cytology in terms of sensitivity, but it exhibited a significantly higher specificity in comparison to ASCH+. A triage test after HPV-DNA detection using the HPV16/18-E6 test exhibited a significantly higher specificity compared with a triage test of ASCH+ to CIN2+ (91.8% vs. 87.4%, p = 0.04) and CIN3+ (88.6% vs. 84.0%, p = 0.05).
Conclusion
The HPV16/18-E6 test exhibited moderate/high agreement with the HPV-DNA test but lower sensitivity and higher specificity for the detection of CIN2+ and CIN3+. In addition, its performance was quite similar to cytology, but because of the structural design addressed for the detection of HPV16/18-E6 protein, the test can miss some CIN2/3+ lesions caused by other high-risk HPV types.Cancer Prevention Department, Center for the Researcher Support and Pathology Department of the Barretos Cancer Hospital. This study was supported by CNPq 573799/2008-3 and FAPESP 2008/57889-1info:eu-repo/semantics/publishedVersio
The ThomX project status
Work supported by the French Agence Nationale de la recherche as part of the program EQUIPEX under reference ANR-10-EQPX-51, the Ile de France region, CNRS-IN2P3 and Université Paris Sud XI - http://accelconf.web.cern.ch/AccelConf/IPAC2014/papers/wepro052.pdfA collaboration of seven research institutes and an industry has been set up for the ThomX project, a compact Compton Backscattering Source (CBS) based in Orsay - France. After a period of study and definition of the machine performance, a full description of all the systems has been provided. The infrastructure work has been started and the main systems are in the call for tender phase. In this paper we will illustrate the definitive machine parameters and components characteristics. We will also update the results of the different technical and experimental activities on optical resonators, RF power supplies and on the electron gun
- …