Impact of Tube Voltage on Radiation Dose (CTDI) and Image Quality at Chest CT Examination

During Computed Tomography (CT) scan examinations, it is important to ensure a good diagnosis by providing the maximum information to detect pathologies and this can be done with a reduced dose. In this respect, several methods of dose reduction have been studied and evaluated. This work investigates the effect of tube voltage while varying the tube current on image quality and radiation dose at Chest CT examination. This study was conducted on HITACHI CT 16 slice Scanner using two phantoms for evaluating the dose and image quality; a PMMA phantom and a CATPHAN 500. Two tube voltages of 120 KVp and 100 KVp have been used for some variation of the tube currents (mAs) and recording the values of the measured quantities (CTDIv, spatial resolution, contrast to noise ratio CNR and noise). The scanning with 100 KVp at Chest CT examination led to a reduction in CTDIv until 45 %, an increase of noise from 17 % to 45 %, and the Spatial Resolution fell slightly (6 and 7 pl/cm) compared to the 120 KVp. The CNR shows a slight regression from 11 to 22 % for the 120 KVp and 100 KVp. This study has shown that despite the increase in the image noise at low tube voltage 100 KVp, it is possible to reduce the radiation dose by up to 45 % without degradation of image quality at Chest CT examination. Further works will evaluate the effect of acquisition parameters in other CT examinations

Biofilm inhibition of Inula viscosa (L.) Aiton and Globularia alypum L. extracts against Candida infectious pathogens and In vivo action on galleria mellonella model

The increasing importance of fungal infections has fueled the search for new beneficial alternatives substance from plant extracts. The current study investigates the antifungal and antibiofilm activity of Inula viscosa (L.) Aiton and Globularia alypum (L.) leaves extracts against Candida both in vitro and in vivo. The inhibition of planktonic and sessile Candida albicans and Candida glabrata growth using both leaf extracts are evaluated. Moreover; an in vivo infection model using Galleria mellonella larvae; infected and treated with the extracts are performed. All extracts show fungicidal activity; with a minimum fungicidal concentration (MFC) ranging from 128 to 512 mu g mL(-1) against the two selected strains of Candida. In particular, the best results are obtained with methanolic extract ofI. viscosa and G. alypum with an MFC value of 128 mu g mL(-1). The extracts are capable to prevent 90% of biofilm development at minor concentrations ranging from 100.71 +/- 2.49 mu g mL(-1) to 380.4 +/- 0.92 mu g mL(-1). In vivo, tests on Galleria mellonella larvae show that the extracts increase the survival of the larvae infected with Candida. The attained results reveal that I. viscosa and G. alypum extracts may be considered as new antifungal agents and biofilm inhibiting agents for the pharmaceutical and agro-food field

Toxicity Profile of the Aqueous Ethanol Root Extract of Corrigiola telephiifolia Pourr. (Caryophyllaceae) in Rodents

Corrigiola telephiifolia Pourr. (Caryophyllaceae) is a Moroccan medicinal plant. Despite its popular usage, no study has been published concerning its toxicological profile. The acute toxicity of C. telephiifolia root extract was evaluated by giving it orally to mice at single doses of 5000, 10000, and 14000 mg/kg bodyweight. The extract was also administered at doses of 5, 70, and 2000 mg/kg bodyweight per day to rats for a forty-day toxicity study. No mortality or signs of toxicity were observed in the acute study. In the forty-day study in rats, the extract at 5 mg/kg/day showed no toxicological effects in either sex. At 70 mg/kg/day, the treated group differed from the control only by a significant decrease in serum concentrations of sodium and chloride ions (P < .05). At the dose of 2000 mg/kg/day, the extract significantly increased the serum concentrations of creatinine, alkaline phosphatase, gamma-glutamyltransferase and phosphorus (P < .05) all suggestive of functional nephrotoxicity and hepatotoxicity. The relative bodyweight of both sexes decreased at the dose of 2000 mg/kg/day, with a fast recovery for males. Histological examination did not reveal any treatment-related effects. In conclusion, Corrigiola extract appears safe at the doses used ethno-medicinally. Much higher doses pose toxicological risks

Special biconformal changes of K\"ahler surface metrics

The term "special biconformal change" refers, basically, to the situation where a given nontrivial real-holomorphic vector field on a complex manifold is a gradient relative to two K\"ahler metrics, and, simultaneously, an eigenvector of one of the metrics treated, with the aid of the other, as an endomorphism of the tangent bundle. A special biconformal change is called nontrivial if the two metrics are not each other's constant multiples. For instance, according to a 1995 result of LeBrun, a nontrivial special biconformal change exists for the conformally-Einstein K\"ahler metric on the two-point blow-up of the complex projective plane, recently discovered by Chen, LeBrun and Weber; the real-holomorphic vector field involved is the gradient of its scalar curvature. The present paper establishes the existence of nontrivial special biconformal changes for some canonical metrics on Del Pezzo surfaces, viz. K\"ahler-Einstein metrics (when a nontrivial holomorphic vector field exists), non-Einstein K\"ahler-Ricci solitons, and K\"ahler metrics admitting nonconstant Killing potentials with geodesic gradients.Comment: 16 page

LES PANCREATITES MEDICAMENTEUSES DIFFICULTES DIAGNOSTIQUES ET THERAPEUTIQUES

Les pancréatites médicamenteuses sont rares mais potentiellement graves. Plusieurs médicaments sont incriminés. Le diagnostic positif repose sur l’établissement d’un lien entre le médicament et la pancréatite aiguë et sur la consultation des centres de pharmacovigilance et des revues de la littérature. Le but de notre travail est de rappeler les différentes étapes du diagnostic et d’insister sur l’importance de la pharmacovigilance. La difficulté diagnostique réside dans le fait que les manifestations cliniques des pancréatites médicamenteuses sont peu spécifiques. De plus, le lien entre un médicament et la survenue d’une pancréatite médicamenteuse peut être difficile à établir. Il repose sur plusieurs critères : sémiologiques, chronologiques et bibliographiques.Une liste de médicaments de plus en plus étendue est mise en cause. Cette liste ne saurait être exhaustive car chaque jour, de nouvelles molécules sont signalées aux centres de pharmacovigilance. La prise en charge des pancréatites médicamenteuses comprend un volet symptomatique mais aussi un volet étiologique qui consiste en un arrêt immédiat du médicament en cause.The drug-induced pancreatitis are rare but potentially serious. Several drugs are accused. The positive diagnosis rests on: - Establishment of a bond between the drug and the acute pancreatitis. -Consultation of centers of pharmacovigilance and reviews of literature. The aim of our work is to point out the various stages of the diagnosis and to insist on the importance of the pharmacovigilance. The diagnostic difficulty lies in the fact that the clinical demonstrations of the drug-induced pancreatitis are not very specific. Moreover, the bond between a drug and occurred of a drug-induced pancreatitis can be difficult to establish.  It rests on several criteria: semiological, chronological and bibliographical. Un increasingly wide list of drugs is blamed. This list could not be exhaustive because each day, of new molecules are announced to the centers of pharmacovigilance. The assumption of responsibility of the drug-induced pancreatitis comprises a symptomatic aspect but also a shutter etiologic which consists of a dead halt of the drug in question

LEÏOMYOSARCOME UTERIN DE PRESENTATION INHABITUELLE

Utérin Leiomyosarcoma is rare [1.5]. It is likely conjunctiva and developed at the expense of mesenchymal elements of the myometrium. The uterus bicornis united cervical represents 39% of all uterine malformations [8]. The prevalence of these abnormalities is estimated at 0.5%. The association leïomyosarcoma and uterine malformation still very exceptional. The purpose of our work is to study the unique combination from the clinical, paraclinical, pathological, and evolving therapeutic.Le léiomyosarcome utérin est une tumeur maligne, rare [1,5].Elle est de nature conjonctive et développée aux dépens des éléments mésenchymateux du myomètre. L’utérus bicorne uni cervical représente 39% de l’ensemble des malformations utérines [8]. La prévalence de ces malformations est estimée à 0,5%. L’association leïomyosarcome utérin et malformation utérine reste très exceptionnelle et ce du fait que la malformation utérine est de diagnostic précoce à un âge jeune contrairement au leiomyosarcome utérin qui survient chez des femmes d’âge avancé. Le but de notre travail est d’étudier à partir de notre observation cette association exceptionnelle sur le plan clinique, paraclinique, anatomopathologique, thérapeutique et évolutif

Quantification of ciprofloxacin in pharmaceutical products from various brands using FT-NIR: A comparative investigation of PLS and MCR-ALS.

peer reviewedThis study aims to quantify ciprofloxacin in commercial tablets with varying excipient compositions using Fourier Transform Near-Infrared Spectroscopy (FT-NIR) and chemometric models: Partial Least Squares (PLS) and Multivariate Curve Resolution - Alternating Least Squares (MCR-ALS). Matrix variation, arising from differences in excipient compositions among the tablets, can impact quantification accuracy. We discuss this phenomenon, emphasizing potential issues introduced by varying certain excipients and its importance in reliable ciprofloxacin quantification. We evaluated the performance of PLS and MCR-ALS models independently on two sets of tablets, each containing the same drug substance but different excipients. The statistical results revealed promising results with PLS prediction error of 0.38% w/w of the first set and 0.47% w/w of the second set, while MCR-ALS achieved prediction errors of 0.67% w/w of the first set and 1.76% w/w of the second set. To address the challenge of matrix variation, we developed single models for PLS and MCR-ALS using a dataset combining both first and second sets. The PLS single model demonstrated a prediction error of 4.3% w/w and a relative error of 6.41% w/w, while the MCR-ALS single model showed a prediction error of 1.88% w/w and a relative error of 1.29% w/w. We then assessed the performance of the single PLS and MCR-ALS models developed based on the combination of the first and the second set in quantifying ciprofloxacin in various commercial tablet brands containing new excipients. The PLS model achieved a prediction error ranging between 6.2% w/w and 8.39% w/w, with relative errors varied between 8.53% w/w and 12.82% w/w. On the other hand, the MCR-ALS model had a prediction error between 1.11% w/w and 2.66% w/w, and the relative errors ranging from 0.8% to 1.74% w/w

Une cause rare d’exophtalmie

Une enfant de 3 ans, issue d’un mariage non consanguin, deuxième d’une fratrie de 3, et sans antécédents pathologiques particuliers. Le début de la symptomatologie remonte à un mois par la constatation par la maman d’une exophtalmie de l’œil gauche qui augmentait rapidement de volume sans autres signes associés. A l’examen clinique, on notait la présence d’une importante exophtalmie de l’œil gauche avec bombement du cavum sans déficits neurologiques, le fond d’œil a objectivé une atrophie optique temporale. Une tomodensitométrie orbitaire a objectivé un processus énorme intra-orbitaire iso dense infiltrant la base du crâne, le sinus caverneux, le sinus sphénoïdal gauche  avec extension vers le cavum sur une étendue de 40 mm

Accelerated expansion from structure formation

We discuss the physics of backreaction-driven accelerated expansion. Using the exact equations for the behaviour of averages in dust universes, we explain how large-scale smoothness does not imply that the effect of inhomogeneity and anisotropy on the expansion rate is small. We demonstrate with an analytical toy model how gravitational collapse can lead to acceleration. We find that the conjecture of the accelerated expansion being due to structure formation is in agreement with the general observational picture of structures in the universe, and more quantitative work is needed to make a detailed comparison.Comment: 44 pages, 1 figure. Expanded treatment of topics from the Gravity Research Foundation contest essay astro-ph/0605632. v2: Added references, clarified wordings. v3: Published version. Minor changes and corrections, added a referenc