A Review of Bulk Powder Caking

The handling and storage of bulk powders is common in many industries such as detergent, pharmaceutical, bulk chemical and food. A lot of materials are susceptible to changes with time that may lead to bulk powder caking, resulting in an unmanageable powder and process downtime, which impacts upon profitability. In this review the current state of the art related to powder caking is explored. The relevant interparticle interactions are discussed with respect to elastic and plastic deformations and the development of liquid and solid bridges due to capillary condensation, sintering and solvent evaporation. The environmental, i.e. temperature and humidity, and the mechanical conditions can heavily influence the transformation of a bulk powder and a number of studies are available that attempt to relate these conditions to caking. A significant amount of work related to the caking behaviour of amorphous powders is available in the literature. Amorphous materials are susceptible to caking due to environmental conditions influencing the glass transition temperature. Once the temperature of amorphous powders exceeds the glass transition, viscous flow occurs and cake strength increases. Crystalline solids may undergo transformations leading to caking. It can take a considerable time and cyclic environmental conditions for caking to occur. However, little research focuses on cyclic conditions and there is limited predictive capability. Finally the options available for attempting to reduce caking propensity are briefly covered and a section that discusses the available caking test methods is given

Estudo da Influência da Interação Solo-atmosfera nos Perfis de Umidade, Sucção e Temperatura de um Subsolo Não Saturado.

Este trabalho dedica-se à análise da influência da interação solo-atmosfera nos perfis de umidade, sucção e temperatura do perfil de um subsolo não saturado. Também é objeto de interesse neste estudo a análise da profundidade da zona ativa, região do solo influenciada pelas variações climáticas. Um modelo numérico de interface solo-atmosfera é utilizado para calcular a taxa de evaporação a partir do solo, e a equação de fluxo de massa (água líquida Lei de Darcy e vapor Lei de Fick) em conjunto com a equação de fluxo de calor (de Vries, 1987) são adotadas para determinar os perfis de temperatura, umidade e poro pressão do solo. Para as simulações numéricas é adotado um programa computacional unidimensional que utiliza o Método das Diferenças Finitas para resolver simultaneamente as equações diferencias parciais de fluxo de massa (água líquida e vapor) e calor. As análises realizadas utilizam dados climáticos coletados em Mormoiron, França, obtidos entre 2004 e 2005. Durante as análises, parâmetros foram alterados e dados climáticos simulados, sendo os resultados obtidos comparados com casos de referência. Dentre as conclusões do trabalho, pode-se citar: (a) a variação do perfil inicial de temperatura do solo (PIT) pode afetar os perfis de temperatura do solo, especialmente na região mais profunda onde as temperaturas se mantém praticamente estáveis ao longo de todo o ano; (b) o parâmetro Albedo pode afetar o perfil de temperatura do solo, especialmente na estação mais quente (grande radiação solar). Durante o inverno, valores albedo precisos não influenciam o teor de água no solo; (c) a zona ativa na região do estudo possui cerca de 1,5 m de profundidade. A partir dessa profundidade os perfis de temperatura, umidade e sucção do solo se mantém praticamente constantes ao longo do ano; (d) a utilização de médias para os inputs diários modifica a profundidade da zona ativa, sugerindo que sob condições adversas a profundidade da zona ativa de uma determinada região pode ser alterada; (e) a intensidade e a distribuição da precipitação afetam os perfis de umidade volumétrica e sucção do solo

A gain-scheduled PID controller for propofol dosing in anesthesia

6siA gain-scheduled proportional-integral-derivative controller is proposed for the closed-loop dosing of propofol in anesthesia (with the bispectral index as a controlled variable). In particular, it is shown that a different tuning of the parameters should be used during the infusion and maintenance phases. Further, the role of the noise filter is investigated.nonenonePadula, F.; Ionescu, C.; Latronico, N.; Paltenghi, M.; Visioli, A.; Vivacqua, G.Padula, Fabrizio; Ionescu, C.; Latronico, Nicola; Paltenghi, M.; Visioli, Antonio; Vivacqua, Giuli

Chronic MPTP in Mice Damage-specific Neuronal Phenotypes within Dorsal Laminae of the Spinal Cord

The neurotoxin 1-methyl, 4-phenyl, 1, 2, 3, 6-tetrahydropiridine (MPTP) is widely used to produce experimental parkinsonism. Such a disease is characterized by neuronal damage in multiple regions beyond the nigrostriatal pathway including the spinal cord. The neurotoxin MPTP damages spinal motor neurons. So far, in Parkinson’s disease (PD) patients alpha-synuclein aggregates are described in the dorsal horn of the spinal cord. Nonetheless, no experimental investigation was carried out to document whether MPTP affects the sensory compartment of the spinal cord. Thus, in the present study, we investigated whether chronic exposure to small doses of MPTP (5 mg/kg/X2, daily, for 21 days) produces any pathological effect within dorsal spinal cord. This mild neurotoxic protocol produces a damage only to nigrostriatal dopamine (DA) axon terminals with no decrease in DA nigral neurons assessed by quantitative stereology. In these experimental conditions we documented a decrease in enkephalin-, calretinin-, calbindin D28K-, and parvalbumin-positive neurons within lamina I and II and the outer lamina III. Met-Enkephalin and substance P positive fibers are reduced in laminae I and II of chronically MPTP-treated mice. In contrast, as reported in PD patients, alpha-synuclein is markedly increased within spared neurons and fibers of lamina I and II after MPTP exposure. This is the first evidence that experimental parkinsonism produces the loss of specific neurons of the dorsal spinal cord, which are likely to be involved in sensory transmission and in pain modulation providing an experimental correlate for sensory and pain alterations in PD

The emerging role of ferroptosis in liver cancers

: Liver cancer represents a global health challenge with worldwide growth. Hepatocellular carcinoma (HCC) is the most common type of liver cancer. Indeed, approximately 90% of HCC cases have a low survival rate. Moreover, cholangiocarcinoma (CC) is another malignant solid tumor originating from cholangiocytes, the epithelial cells of the biliary system. It is the second-most common primary liver tumor, with an increasing course in morbidity and mortality. Tumor cells always show high metabolic levels, antioxidant modifications, and an increased iron uptake to maintain unlimited growth. In recent years, alterations in iron metabolism have been shown to play an important role in the pathogenesis of HCC. Several findings show that a diet rich in iron can enhance HCC risk. Hence, elevated iron concentration inside the cell may promote the development of HCC. Growing evidence sustains that activating ferroptosis may potentially block the proliferation of HCC cells. Even in CC, it has been shown that ferroptosis plays a crucial role in the treatment of tumors. Several data confirmed the inhibitory effect in cell growth of photodynamic therapy (PDT) that can induce reactive oxygen species (ROS) in CC, leading to an increase in malondialdehyde (MDA) and a decrease in intracellular glutathione (GSH). MDA and GSH depletion/modulation are crucial in inducing ferroptosis, suggesting that PDT may have the potential to induce this kind of cell death through these ways. A selective induction of programmed cell death in cancer cells is one of the main treatments for malignant tumors; thus, ferroptosis may represent a novel therapeutic strategy against HCC and CC

Prediction of Ideas Number During a Brainstorming Session

International audienceIn this paper, we present an approach allowing the prediction of ideas number during a brainstorming session. This prediction is based on two dynamic models of brainstorming, the non-cognitive and the cognitive models proposed by Brown and Paulus (Small Group Res 27(1):91–114, 1996). These models describe for each participant, the evolution of ideas number over time, and are formalized by differential equations. Through solution functions of these models, we propose to calculate the number of ideas of each participant on any time intervals and thus in the future (called prediction). To be able to compute solution functions, it is necessary to determine the parameters of these models. In our approach, we use optimization model for model parameters calculation in which solution functions are approximated by numerical methods. We developed two generic optimization models, one based on Euler’s and the other on the fourth order Runge–Kutta’s numerical methods for the solving of differential equations, and we apply them to the non-cognitive and respectively to the cognitive models. Through some feasibility tests, we show the adequacy of the proposed approach to our prediction context

Aggregated a-synuclein and complex I deficiency: exploration of their relationship in differentiated neurons

α-Synuclein becomes misfolded and aggregated upon damage by various factors, for example, by reactive oxygen species. These aggregated forms have been proposed to have differential toxicities and their interaction with mitochondria may cause dysfunction within this organelle that contributes to the pathogenesis of Parkinson’s disease (PD). In particular, the association of α-synuclein with mitochondria occurs through interaction with mitochondrial complex I and importantly defects of this protein have been linked to the pathogenesis of PD. Therefore, we investigated the relationship between aggregated α-synuclein and mitochondrial dysfunction, and the consequences of this interaction on cell survival. To do this, we studied the effects of α-synuclein on cybrid cell lines harbouring mutations in either mitochondrial complex I or IV. We found that aggregated α-synuclein inhibited mitochondrial complex I in control and complex IV-deficient cells. However, when aggregated α-synuclein was applied to complex I-deficient cells, there was no additional inhibition of mitochondrial function or increase in cell death. This would suggest that as complex I-deficient cells have already adapted to their mitochondrial defect, the subsequent toxic effects of α-synuclein are reduced

GPR30, the Non-Classical Membrane G Protein Related Estrogen Receptor, Is Overexpressed in Human Seminoma and Promotes Seminoma Cell Proliferation

BACKGROUND: Testicular germ cell tumours are the most frequent cancer of young men with an increasing incidence all over the world. Pathogenesis and reasons of this increase remain unknown but epidemiological and clinical data have suggested that fetal exposure to environmental endocrine disruptors (EEDs) with estrogenic effects, could participate to testicular germ cell carcinogenesis. However, these EEDs (like bisphenol A) are often weak ligands for classical nuclear estrogen receptors. Several research groups recently showed that the non classical membrane G-protein coupled estrogen receptor (GPER/GPR30) mediates the effects of estrogens and several xenoestrogens through rapid non genomic activation of signal transduction pathways in various human estrogen dependent cancer cells (breast, ovary, endometrium). The aim of this study was to demonstrate that GPER was overexpressed in testicular tumours and was able to trigger JKT-1 seminoma cell proliferation. RESULTS: We report here for the first time a complete morphological and functional characterization of GPER in normal and malignant human testicular germ cells. In normal adult human testes, GPER was expressed by somatic (Sertoli cells) and germ cells (spermatogonia and spermatocytes). GPER was exclusively overexpressed in seminomas, the most frequent testicular germ cell cancer, localized at the cell membrane and triggered a proliferative effect on JKT-1 cells in vitro, which was completely abolished by G15 (a GPER selective antagonist) and by siRNA invalidation. CONCLUSION: These results demonstrate that GPER is expressed by human normal adult testicular germ cells, specifically overexpressed in seminoma tumours and able to trigger seminoma cell proliferation in vitro. It should therefore be considered rather than classical ERs when xeno-estrogens or other endocrine disruptors are assessed in testicular germ cell cancers. It may also represent a prognosis marker and/or a therapeutic target for seminomas

Impaired leukocyte influx in cervix of postterm women not responding to prostaglandin priming

<p>Abstract</p> <p>Background</p> <p>Prolonged pregnancies are associated with increased rate of maternal and fetal complications. Post term women could be divided into at least two subgroups, one where parturition is possible to induce by prostaglandins and one where it is not. Our aim was to study parameters in cervical biopsies in women with spontaneous delivery at term (controls) and compare to those that are successfully induced post term (responders), and those that are not induced (non-responders), by local prostaglandin treatment.</p> <p>Methods</p> <p>Stromal parameters examined in this study were the accumulation of leukocytes (CD45, CD68), mRNAs and/or proteins for the extracellular matrix degrading enzymes (matrix metalloproteinase (MMP)-2, MMP-8 and MMP-9), their inhibitors (tissue inhibitor of MMP (TIMP)-1 and TIMP-2), interleukin-8 (IL-8), the platelet activating factor-receptor (PAF-R), syndecan-1 and estrogen binding receptors (estrogen receptor (ER)α, ERβ and G-coupled protein receptor (GPR) 30) as well as the proliferation marker Ki-67.</p> <p>Results</p> <p>The influx of leukocytes as assessed by CD45 was strongest in the responders, thereafter in the controls and significantly lower in the non-responders. IL-8, PAF-R and MMP-9, all predominantly expressed in leukocytes, showed significantly reduced immunostaining in the group of non-responders, while ERα and GPR30 were more abundant in the non-responders, as compared to the controls.</p> <p>Conclusion</p> <p>The impaired leukocyte influx, as reflected by the reduced number of CD45 positive cells as well as decreased immunostaining of IL-8, PAF-R and MMP-9 in the non-responders, could be one explanation of the failed ripening of the cervix in post term women. If the decreased leukocyte influx is a primary explanation to absent ripening or secondary, as a result of other factors, is yet to be established.</p

Beneficial Effects of Estrogen in a Mouse Model of Cerebrovascular Insufficiency

BACKGROUND: The M(5) muscarinic acetylcholine receptor is known to play a crucial role in mediating acetylcholine dependent dilation of cerebral blood vessels. Previously, we reported that male M(5) muscarinic acetylcholine knockout mice (M5R(-/-) mice) suffer from a constitutive constriction of cerebral arteries, reduced cerebral blood flow, dendritic atrophy, and short-term memory loss, without necrosis and/or inflammation in the brain. METHODOLOGY/PRINCIPAL FINDINGS: We employed the Magnetic Resonance Angiography to study the area of the basilar artery in male and female M5R(-/-) mice. Here we show that female M5R(-/-) mice did not show the reduction in vascular area observed in male M5R(-/-) mice. However, ovariectomized female M5R(-/-) mice displayed phenotypic changes similar to male M5R(-/-) mice, strongly suggesting that estrogen plays a key role in the observed gender differences. We found that 17beta-estradiol (E2) induced nitric oxide release and ERK activation in a conditional immortalized mouse brain cerebrovascular endothelial cell line. Agonists of ERalpha, ERbeta, and GPR30 promoted ERK activation in this cell line. Moreover, in vivo magnetic resonance imaging studies showed that the cross section of the basilar artery was restored to normal in male M5R(-/-) mice treated with E2. Treatment with E2 also improved the performance of male M5R(-/-) mice in a cognitive test and reduced the atrophy of neural dendrites in the cerebral cortex and hippocampus. M5R(-/-) mice also showed astrocyte swelling in cortex and hippocampus using the three-dimensional reconstruction of electron microscope images. This phenotype was reversed by E2 treatment, similar to the observed deficits in dendrite morphology and the number of synapses. CONCLUSIONS/SIGNIFICANCE: Our findings indicate that M5R(-/-) mice represent an excellent novel model system to study the beneficial effects of estrogen on cerebrovascular function and cognition. E2 may offer new therapeutic perspectives for the treatment of cerebrovascular insufficiency related memory dysfunction