Literatura científica selecionada sobre o tema "Concentration de la norme L3"

Two potential novels Schiff base iron (Fe) complexes Fe-L2 and Fe-L3 (where L2= N, N'-bis (o-hydroxyacetophenone) ethylenediamine and L3= N, N'-bis (o-hydroxybenzaldehyde) phenylenediamine) were synthesized from interaction a hot methanolic solution of each ligand L2 or L3 (0.01mole) with the appropriate amount of Fe (NO3)3.9H2O metal salt (0.01mole). This study investigated the cytotoxicity induced by both complexes (0.1 to 100 µg/ml) in MCF-7 and MDA-MB 231 cell lines. After 24 hours of treatment, the cell viabilities of both MCF-7 and MDA-MB-231 cells were linearly proportional to the Fe-L2 concentrations. A higher concentration of Fe-L2 would cause higher cell killings. On the other hand, most of the Fe-L3 concentrations caused total cell deaths for both cell lines, except for the lowest concentration (0.1 µg/ml). Fe-L2 and Fe-L3 also caused lower cell viability of MDA-MB-231 cells compared to MCF-7 cells. Overall, the obtained Fe-L3 is more toxic than Fe-L2 in breast cancer cells. It is suggested that the Fe-L3 is an excellent agent against breast cancer cells; meanwhile, the Fe-L2 is biocompatible and a good support in medical applications, especially as a radiosensitizer in radiotherapy.

AbstractIn vitro chemotactic responses of infective third-stage larvae (L3) of Brugia pahangi to NaCl, Na2HPO4, KCl, K2HPO4, MgCl2 and CaCl2 were assessed. Compared to deionized water as a control, 200 mm NaCl and 100 mm Na2HPO4 significantly attracted L3 (P < 0.01 and P < 0.01), whereas L3 were likely to avoid 200 mm KCl and 100 mm K2HPO4 (P < 0.05 and P < 0.05). L3 showed no significant tendency to avoid or to be attracted to 200 mm CaCl2 and 200 mm MgCl2. Furthermore, NaCl exhibited a significant chemoattractant activity for L3 at a low concentration of 100 mm.

In vitro effects of some household chemicals on infective larvae (L3) of Haemonchus contortus of goat were screened during the period from January 2002 to April 2003. Solutions of 0.5, 1, 5, 10 and 20 mg / ml were screened for in vitro effects on infective larvae (L3) of Haemonchus contortus. The percent non-motile L3 was increased when immersed in increasing solutions of the household chemicals (p < 0.01) except sodium chloride. Of 10 household chemicals, potassium permanganate showed 100% in vitro larvicidal effect at 1 mg / ml concentration. Boric acid showed the second highest larvicidal effect (78.95%) followed by alum (71.86%), bleaching powder (71.43%) and borax (68.97%) at their highest concentration of 20 mg / ml.

The effect of macrocyclic ligands on cytotoxic concentrations of the transition metal ions of copper, zinc, and cadmium was investigated. For this purpose, a hexaaza-[3,6,9,17,20,23-hexaazatricyclo[23.3.1.111,15] triaconta–1(29),11(30),12,14,25,27–hexaene (L2)] and hexathia-chelating ligand [1,4,7,10,13,16-hexathiacyclooctadecane (L3)] were used in the human hepatoma-derived HepG2 cell line. The cytotoxicity was measured by the neutral red uptake inhibition assay. First, the NI50 of the ligands, i.e., the concentration of the ligand inducing a 50% inhibition in neutral red uptake compared to control cells, was determined. In several metal/ligand combination experiments, the effects for L2 were difficult to interpret, whereas for L3 in combination with copper ions, a severe increase–and for zinc ions, a significant decrease of cell toxicity–relative to the metal control was observed. To further examine the different effects observed with L3 in combination with, respectively, Cu2+ and Zn2+, the glutathione (GSH) content was measured. The relative GSH content decreased as the concentration of L3 increased. It was proposed that the increased toxicity of the combination Cu2+ /L3 could be caused by the depletion of GSH and a subsequent inability to scavenge the produced reactive oxygen species (ROS). This hypothesis was supported by experiments during which vitamin E or C was added to the Cu2+ / L3 system.

The hormonal form of vitamin D3, 1,25(OH)2D3, reduces UV-induced DNA damage. UV exposure initiates pre-vitamin D3 production in the skin, and continued UV exposure photoisomerizes pre-vitamin D3 to produce “over-irradiation products” such as lumisterol3 (L3). Cytochrome P450 side-chain cleavage enzyme (CYP11A1) in skin catalyzes the conversion of L3 to produce three main derivatives: 24-hydroxy-L3 [24(OH)L3], 22-hydroxy-L3 [22(OH)L3], and 20,22-dihydroxy-L3 [20,22(OH)L3]. The current study investigated the photoprotective properties of the major over-irradiation metabolite, 24(OH)L3, in human primary keratinocytes and human skin explants. The results indicated that treatment immediately after UV with either 24(OH)L3 or 1,25(OH)2D3 reduced UV-induced cyclobutane pyrimidine dimers and oxidative DNA damage, with similar concentration response curves in keratinocytes, although in skin explants, 1,25(OH)2D3 was more potent. The reductions in DNA damage by both compounds were, at least in part, the result of increased DNA repair through increased energy availability via increased glycolysis, as well as increased DNA damage recognition proteins in the nucleotide excision repair pathway. Reductions in UV-induced DNA photolesions by either compound occurred in the presence of lower reactive oxygen species. The results indicated that under in vitro and ex vivo conditions, 24(OH)L3 provided photoprotection against UV damage similar to that of 1,25(OH)2D3.

AbstractUrocanic acid (UCA) is known as a major chemoattractant for Strongyloides stercoralis infective third-stage larvae (L3). Since Brugia pahangi is a skin-penetrating parasitic nematode similar to S. stercoralis, UCA was expected to be a chemoattractant for B. pahangi L3. Thus, the chemoattractant activity of UCA for B. pahangi L3 was assessed. The chemotactic responses of B. pahangi L3 to UCA or acetic acid (CH3COOH) dissolved in amine solutions were assessed using an agar-plate assay. A test solution of 200 mm UCA dissolved in aqueous 270 mm tris(hydroxymethyl)aminomethane (Tris) significantly attracted B. pahangi L3 compared with deionized water (DW), while neither a solution of 200 mm UCA dissolved in aqueous 230 mm ammonia (NH3) nor 290 mm triethylamine (TEA) significantly attracted L3. Similarly, a test solution of 200 mm CH3COOH dissolved with 200 mm Tris significantly attracted L3, but neither a test solution of 200 mm CH3COOH plus 200 mm NH3 nor 200 mm TEA attracted L3. Furthermore, L3 were significantly attracted to 200 mm Tris alone, compared with DW, but avoided 200 mm NH3 and 200 mm TEA. Moreover, the chemoattractant activity of Tris for L3 was observed even at a low concentration of 25 mm, and it was observed in a mild alkaline condition but not in an acidic condition. The present study reveals that Tris is a potential chemoattractant for B. pahangi L3 while UCA is not. This finding will contribute to an understanding of the mechanisms of skin-penetrating infection of filarial L3.

To save costs in preparation of Bacillus mucilaginous L3, we studied the effects of culture temperature, pH, culture time, oscillation frequency, and medium concentration on the biomass OD600 of B. mucilaginous L3 using orthogonal tests and back-propagation neural networks. The influence factors on OD600 ranked as importance as temperature > pH > culture time > medium concentration > oscillation frequency. The training precision of the growth predictive model based on back-propagation neural networks was up to 99.308%. The optimal prediction ranges of different factors were temperature: 28–30 °C, pH: 7.1–7.4, medium concentration: 2–4 and 7–8 g/L, culture time: 46–49 h, and oscillation frequency: 175–190 and 120–130 r/min.

Haemonchus contortus is the most frequent and most important nematode parasite in the ruminants production of tropical and subtropical regions. There are strains resistant to all families of available anthelmintics. Consequently, the conduction of research to find other resources that allow effective control of this parasitic disease, preferably focusing on green production, is necessary. The aim of this study was to evaluate the effect of hydrolysable tannin extract (HTE) on larvae 3 (L3) of H. contortus in vitro. L3 were exposed to different HTE concentrations and times. In addition, both light and scanning electron microscopy were used to explore physical damage on L3 subjected to HTE activity. After 72 h of incubation, the mean lethal concentration of HTE was 2 mg/mL; this concentration has been previously referred to as safe for consumption in cattle. Scanning electron microscopy revealed H. contortus L3 destruction, damage was evident by separation of the sheath mainly in the cervical and caudal regions of the larva and by rupture of the cuticle with larval evisceration. Our results suggest that hydrolysable tannin extract from chestnut could be considered as a green alternative for parasitic control in ruminants.

AbstractThe content of carbohydrates in L3 and L4 larvae of Anisakis simplex (defined by Rokicki J.) was studied. Glycogen and trehalose were their major reserve sugars. The concentration of saccharides in L4 larvae was 2–3-times higher than in L3 larvae. The content of glycogen was 3.68 ± 1.24 mg/g tissue in L3 larvae and 11.68 ± 1.21 mg/g tissue in L4 larvae. Trehalose represented 16.17 % of soluble sugars in L3 larvae and 43.04 % in L4 larvae. The contents of maltose, higher polymers of glucose (1.5-times) and myoinositol (1.2-times) in L4 were higher than in L3 larvae. After starving the L3 larvae of the parasite for 48 h at 4°C, the contents of trehalose increased 5-fold and that of glycogen by 20 %, while at 37°C the contents of glycogen was ca. 30 % higher and that of trehalose 40 % less than in larvae freshly isolated from the host (p < 0.01). The data obtained during starving the L3 larvae of A. simplex may be a consequence the role of trehalose as protective compound at stress condition. We suggest that probably in higher temperatures it acts as first a source of energy, and it also might serve to restore the levels of glycogen.

Introduction Serum alpha-fetoprotein (AFP) is a useful marker of hepatocellular carcinoma (HCC), although the serum AFP concentration is also increased in patients with chronic liver diseases (CLD). The analysis of AFP glycoforms has been known to be of diagnostic value. We applied the lectin-affinity electrophoresis and antibody-affinity blotting techniques to HCC patients in Vietnam in order to better understand the role of lentil lectin-affinity AFP-L3 in the diagnosis and differential diagnosis of HCC, and its relationship with the biological characteristics of HCC. Methods Lens culinaris agglutinin-reactive AFP (AFP-L3) was measured in 65 patients with histologically proven HCC and 25 patients with CLD. All patients had serum AFP levels above 54 ng/mL. AFP-L3 levels were determined by lectin affinity electrophoresis coupled with antibody-affinity blotting. The diagnosis of HCC was confirmed histologically by ultrasound-guided biopsy. Results The mean value of AFP-L3 in the HCC patients was 49.6 ± 21.6%, which was significantly higher (p<0.001) than that in the 25 CLD patients (10.7 ± 4.3%). When the cutoff level for AFP-L3 was set at 15% (mean ± SD), the sensitivity was 96.9%, the specificity 92.0% and the accuracy 95.5% in the 65 HCC patients. There was no clear correlation between serum AFP level and AFP-L3 percentage (r=0.16). There was no correlation between AFP-L3 and the maximum diameter of HCC nodules (r=0.05). However, the mean AFP-L3 value was higher in moderately or poorly differentiated HCC than in well differentiated tumors (p<0.001). Conclusions AFP-L3 is potentially a clinically useful marker for the differentiation of increased AFP levels in hepatocellular carcinoma and chronic liver diseases. The AFP-L3 percentage is closely related to HCC differentiation. We consider the analysis of AFP-L3 a useful adjunct in the diagnosis of HCC.

Cette thèse est consacrée à l'étude de la relation entre les variables dans les équations des fluides micro-polaires. Ce système, basé sur les équations de Navier-Stokes, consiste en un couplage de deux variables: le champ de vitesse vec{u} et le champ de micro-rotation vec{w}. Notre objectif est de mieux comprendre comment l'information concernant une variable influence le comportement de l'autre. À cette fin, nous avons divisé cette thèse en quatre chapitres, où nous étudierons les propriétés de régularité locale des solutions faibles de type Leray, puis nous nous concentrerons sur la régularité et l'unicité des solutions faibles dans le cas stationnaire. Le premier chapitre présente une rapide déduction physique des équations micro-polaires, suivie de la construction des solutions faibles de type Leray. Dans le chapitre 2, nous commençons par prouver un gain d'intégrabilité pour les deux variables vec{u} et vec{w} lorsque la vitesse appartient à certains espaces de Morrey. Ce résultat souligne un effet de domination de la vitesse. Nous montrons ensuite que cet effet peut également être observé dans le cadre de la théorie de Caffarelli-Kohn-Nirenberg, i.e., sous une hypothèse de petitesse supplémentaire uniquement sur le gradient de la vitesse, nous pouvons démontrer que la solution devient Hölder continue. Pour cela, nous introduisons la notion de solution partiellement adaptée, qui est fondamentale dans ce travail et représente l'une des principales nouveautés. Dans la dernière section de ce chapitre, nous obtenons des résultats similaires dans le contexte du critère de Serrin. Dans le chapitre 3, nous nous concentrons sur le comportement de la norme L^3 de la vitesse vec{u} autour des possibles points où la régularité peut être perdue. Plus précisément, nous établissons un critère d'explosion pour la norme L^3 de la vitesse et améliorons ce résultat en présentant un phénomène de concentration. Nous vérifions également que le cas limite L^infty_t L^3_x du critère de Serrin reste valable pour les équations des fluides micro-polaires. Enfin, le problème de l'existence et de l'unicité des équations stationnaires des fluides micro-polaires est abordé dans le chapitre 4. En effet, nous prouvons l'existence de solutions faibles (vec{u}, vec{w}) dans l'espace d'énergie naturel dot{H}^1(mathbb{R}^3) imes H^1(mathbb{R}^3). De plus, en utilisant la relation entre les variables, nous déduisons que ces solutions sont régulières. Il convient de noter que la solution triviale peut ne pas être unique, et pour surmonter cette difficulté, nous développons un théorème de type Liouville. Ainsi, nous démontrons qu'en imposant une décroissance plus forte à l'infini uniquement sur vec{u}, nous pouvons en déduire l'unicité de la solution triviale (vec{u},vec{w})=(0,0)
This thesis is devoted to the study of the relationship between the variables in the micropolar fluids equations. This system, which is based on the Navier-Stokes equations, consists in a coupling of two variables: the velocity field vec{u} and the microrotation field vec{w}. Our aim is to provide a better understanding of how information about one variable influences the behavior of the other. To this end, we have divided this thesis into four chapters, where we will study the local regularity properties of Leray-type weak solutions, and later we will focus on the regularity and uniqueness of weak solutions for the stationary case. The first chapter presents a brief physical derivation of the micropolar equations followed by the construction of the Leray-type weak solutions. In Chapter 2, we begin by proving a gain of integrability for both variables vec{u} and vec{w} whenever the velocity belongs to certain Morrey spaces. This result highlights an effect of domination by the velocity. We then show that this effect can also be observed within the framework of the Caffarelli-Kohn-Nirenberg theory, i.e., under an additional smallness hypothesis only on the gradient of the velocity, we can demonstrate that the solution becomes Hölder continuous. For this, we introduce the notion of a partial suitable solution, which is fundamental in this work and represents one of the main novelties. In the last section of this chapter, we derive similar results in the context of the Serrin criterion. In Chapter 3, we focus on the behavior of the L^3-norm of the velocity vec{u} near possible points where regularity may get lost. More precisely, we establish a blow-up criterion for the L^3 norm of the velocity and we improve this result by presenting a concentration phenomenon. We also verify that the limit point L^infty_t L^3_x of the Serrin criterion remains valid for the micropolar fluids equations. Finally, the problem of existence and uniqueness for the stationary micropolar fluids equations is addressed in Chapter 4. Indeed, we prove the existence of weak solutions (vec{u}, vec{w}) in the natural energy space dot{H}^1(mathbb{R}^3) imes H^1(mathbb{R}^3). Moreover, by using the relationship between the variables, we deduce that these solutions are regular. It is worth noting that the trivial solution may not be unique, and to overcome this difficulty, we develop a Liouville-type theorem. Hence, we demonstrate that by imposing stronger decay at infinity only on vec{u}, we can infer the uniqueness of the trivial solution (vec{u},vec{w})=(0,0)

A 75-year-old man was referred for evaluation of treatment-resistant transverse myelitis. His medical history included hypertension, coronary artery disease, benign prostatic hyperplasia, and chronic kidney disease. Eight years earlier, the patient noted development of radiating pain down the left lower extremity during long drives, lower extremity weakness and pain, on the left greater than right. He received epidural lumbar corticosteroid injections. Nine months before the current evaluation, his symptoms became refractory, and he underwent surgical decompression with laminectomy at L3-L5. This provided substantial relief for the lower extremity pain. Review of outside magnetic resonance imaging indicated multilevel lumbar stenosis before his surgery and possible, faint, T2-hyperintense cord signal extending into the conus. At the time his symptoms worsened, magnetic resonance imaging of the thoracic spine showed longitudinally extensive T2 hyperintensity extending from the thoracic cord into the conus without contrast enhancement. Evaluation in our department included cerebrospinal fluid analysis, which showed an increased protein concentration of 92 mg/dL, 1 total nucleated cell/µL, normal immunoglobulin G index, and no supernumerary oligoclonal bands. Magnetic resonance angiography of the spinal canal showed mild prominence of vascularity at T10-T12 but no clear spinal dural arteriovenous fistula. However, given the strong suspicion for spinal dural arteriovenous fistula in an older man with progressive myelopathy worsening with corticosteroids, longitudinally extensive lesion extending into the conus, and no evidence of inflammation, spinal digital subtraction angiography was performed. The spinal digital subtraction angiography confirmed the diagnosis of left spinal dural arteriovenous fistula at T11. A T11-12 laminectomy and ligation of the spinal dural arteriovenous fistula was successfully performed without complication. The patient followed up with his local providers for rehabilitation. Spinal dural arteriovenous fistula is the most common spinal arteriovenous malformation, arising from an acquired abnormal connection between a radicular artery and radiculomedullary vein. Progressive congestion and cord edema lead to neurologic deficits over time. Cases are commonly seen in older men with a history of back surgery or trauma. A delay in diagnosis of 1 to 3 years is common.

Objective: Long term clinical data showed that lumbar fusion for Lumbar spinal stenosis (LSS) and lumbar disc degeneration (LDD) therapy could change the loads of disc and articular facet and increase the motion of adjacent segments which lead to facet arthropathy and adjacent level degeneration. This study is to design and analyze an interspinous process device (IPD) that could prevent adjacent level degeneration in the LSS and LDD therapy. Method: The IPD was designed based on anatomical parameters measured from 3D CT images directly. The IPD was inserted at the validated finite element model of the mono-segmental L3/L4. The biomechanical performance of a pair of interbody fusion cages and a paired pedicel screws were studied to compare with the IPD. The model was loaded with the upper body weight and muscle forces to simulate five loading cases including standing, compression, flexion, extension, lateral bending and axial rotation. Results: The interbody fusion cage induced serious stress concentration on the surface of vertebral body, has the worst biomechanical performance among the three systems. Pedicle screws and interbody fusion cage could induce stress concentration within vertebral body which leads to vertebral compression fracture or screw loosening. Regarding to disc protection, the IPD had higher percentage to share the load of posterior lumbar structure than the pedicel screws and interbody fusion cage. Conclusion: IPD has the same loads as pedicle screw-rod which suggests it has a good function in the posterior stability. While the IPD had much less influence on vertebral body. Furthermore, IPD could share the load of intervertebral discs and facet joints to maintain the stability of lumbar spine.

Current techniques focus on generating ZnO nanowires with uniform density and length on a substrate. However, ZnO nanowires with gradients of density and length over a single substrate could make the corresponding devices have varied properties. Here, we have explored the possibility of fabricating nanowires with gradients in density and length using the vapor-solid method via tilting of the substrate using a mixture of ZnO and graphite powder. This setup creates a non-uniform boundary layer (δ) over the substrate which varies the concentration of reactants reaching the surface leading to the asymmetric growth of the nanowires. A 2-D model was developed in Fluent in order to determine the distribution of velocities around the substrate and calculate δ, with the following substrate tilt angles: 0°, 30°, 45°, 60° and 80°. From the simulation results, the variation of δ was maximum for the 80° tilted substrate. Hence, this angle of tilt was chosen for our experiment. The nanowires were sampled for their densities, lengths and diameters at four locations (L1–L4), spaced 5 mm apart. As an application, we have demonstrated the formation of a surface with continuously varying hydrophobicity. The water contact angles measured were as follows: L1: 105°; L2: 116.5°; L3: 129.5°; and L4: 171.0°. A water droplet (volume: 4 μL) was able to move a distance of 10 mm in 0.8 s, with a substrate tilt of ∼1°.

The energy equation handbook is the complete collection of physically coherent expression of energy computed using from 2 to 7 physical units among: density(ML-3) energy (ML2T-2) time (T) force (MLT-2) power (ML2T-3) current (I) temperature (Th) quantity (N) mass (M) length (L) candela (J) surface (L2) volume (L3) concentration (ML-3) frequency (T-1) acceleration (LT- 2) speed (LT-1) pressure (ML-1T-2) viscosity (ML-1T-1) luminance (L- 2J) MolarMass (MN-1) MassicEnergy (L2T-2) resistance (ML2T-3I-2) voltage (ML2T-3I-1) Farad (M-1L-2T4I2) Thermal- Conductivity (MLT-3Th-1) SpecificHeat (L2T-2Th-1) MassFlux (MT-1) SurfaceTension (MT-2) Charge (TI) Resistivity (ML3T-3I-2) The complete list of 4196 equations is sorted by number of variable required to obtain an energy in Joules. All the units are in MKSA.