Mélanges de polymères biodégradables immiscibles : influence de la morphologie sur le contrôle de la libération de substances actives ou modèles

In order to develop biodegradable and active materials s, blends of two incompatible biodegradable polymers have been implemented by conventiona plastic material processing (extrusion). The originality of these blends lies in the search for a strategy to control the release of active species included in one of the phases of the system. Therefore, the tortuosity / availability of selective diffusion paths obtained by varying the relative proportions of the two polymers involved will be exploited. Studied binary systems consist of: [plasticized corn starch, PLS and poly (butylene succinate-co-adipate) or PBSA] and a reference system [(poly (oxyethylene) PEO and PBSA]. In these blends, polar polymers (PLS or PEO) play the role of host matrix to solubilize the active migrants or model molecules which are often polar, and the semi-polar polymer (PBSA) compensates for the weakness of the mechanical properties of the starchy and / or hydrophilic phase while having a low melting temperature (85 ° C) consistent with a longer-term strategy of incorporation of thermostable active molecules such as lysozyme or nisin. The resulting systems were characterized to correlate the different morphologies obtained by varying the composition of the blends (dispersed phase in a continuous matrix, partial or total continuity, or pseudo-layer systems) to the transport phenomena of various molecules. The performed characterizations aim to elucidate the morphologies by i) selective solvent extraction method (or hydrolysis) enriched by microscopical observations ii) using gaseous probes via the determination of water vapor transport properties (water will favor the paths provided by the polar matrix) or oxygen transport properties (O2 will favor the diffusion paths provided by the PBSA matrix) iii) by determining water sorption isotherms and kinetics and finally iv) by the study of the release in water of active or model migrants previously incorporated in the polar phase (sodium fluoresceinate, organic acids, glycine, diglycine). It has been observed that the diffusion phenomena in PLS / PBSA blends are controlled by the tortuosity generated by the presence of PBS and by the limited hydration of the polar phase at high PBSA contents in the blends for water sorption phenomena. Thus, the diffusion of fluorescein, for example, is much more influenced by the tortuosity (itself governed by the composition of the blends) than that of water, which is likely due to its higher molecular weight. For PEO / PBSA blends, distinct behaviors were observed according to the blends composition. For the blends with low or intermediate content of PBSA, rapid transport occurs mainly via the dissolution of the PEO. The morphology did not seem to influence the release kinetics. For high contents of PBSA, the release kinetics were dependent on the morphology and a time lag which is characteristic of permeation kinetics (release proportional to time) appeared. In conclusion, the multiphasic materials prepared by plastic processing look promising for the controlled release of polar migrants such as food preservatives to develop antimicrobial active packagingDans le but de développer des matériaux actifs antimicrobiens biodégradables à libération contrôlée, des mélanges de deux polymères biodégradables incompatibles ont été mis en oeuvre par les voies classiques de transformation des matériaux plastiques (extrusion). L'originalité de ces mélanges réside dans la recherche d'une stratégie de contrôle de la libération d'espèces actives incorporées dans l'une des phases du système et générée par la tortuosité/disponibilité de chemins de diffusion sélectifs obtenue en jouant sur les proportions relatives des 2 polymères en présence. Les systèmes binaires étudiés sont : [amidon de maïs plastifié, PLS et poly(butylène succinate-co-adipate) ou PBSA] et un système référence [(poly(oxyethylène) PEO et PBSA]. Dans ces mélanges, les polymères polaires (PLS ou PEO) jouent le rôle de matrice hôte pour solubiliser les migrants actifs ou modèles, souvent polaires et le polymère semipolaire,le PBSA, compense la faiblesse des propriétés mécaniques et barrières à l'eau de la phase amylacée et /ou hydrophile tout en présentant une température de fusion basse (85°C) compatible avec une stratégie à plus long terme d'incorporation d'actifs peu thermostables. Les systèmes obtenus sont caractérisés afin de corréler les différentes morphologies obtenues en jouant sur la composition des mélanges (phase dispersées dans une matrice continue, ou continuité partielle ou totale, systèmes pseudo-multicouches) aux phénomènes de transport de diverses molécules. Les caractérisations effectuées ont alors pour objectif d'élucider les morphologies obtenues par i) extraction sélective par voie solvant (ou hydrolyse) enrichie par des observations microscopiques ii) par utilisation de sondes gazeuses via les propriétés de transport de vapeur d'eau (qui privilégiera les chemins offerts par la matrice polaire) ou de l'oxygène (qui, lui, privilégiera les chemins de diffusions offerts par le PBSA) iii) par la réalisation des isothermes et cinétiques de sorption d'eau et enfin iv) par l'étude de la libération dans l'eau de migrants actifs ou modèles préalablement incorporés dans la phase polaire (fluorescéinate de sodium, acides organiques, glycine, di-glycine). Il a ainsi pu être montré pour les mélanges PLS/PBSA que les phénomènes de diffusion sont contrôlés par la tortuosité générée par la présence de PBSA dans le cas du relargage de la fluorescéine et par l'hydratation limitée de la phase polaire en présence de fortes teneurs en PBSA dans le mélange pour les phénomènes de sorption d'eau. Ainsi, la diffusion de la fluorescéine, par exemple, est nettement plus influencée que celle de l'eau par la tortuosité (elle-même gouvernée par la composition du mélange), très probablement en raison de sa plus grande masse moléculaire. Pour les mélanges PEO/PBSA, des comportements distincts ont été mis en évidence selon la composition des mélanges. Pour les mélanges à faibles teneurs ou teneurs intermédiaires en PBSA, un transport rapide se produit principalement via la dissolution du PEO. La morphologie ne semble pas influencer les cinétiques de libération. Pour des teneurs élevées en PBSA, la cinétique de libération est cette fois dépendante de la morphologie présente un temps de latence caractéristique d'une cinétique de perméation (libération proportionnelle au temps). En conclusion, les matériaux élaborés par les voies migrants polaires tels que des conservateurs pour élaborer par exemple des emballages actifs antimicrobien

The effect of molar distalization on the maxilla and mandible sagittal relationship

Class II malocclusions is a very common problem, as it constitutes about a quarter to a third of malocclusion cases in the Syrian community, which prompted many researchers to develop appliances to correct this type of malocclusion both dentally and skeletally. Aim: To evaluate changes in the sagittal relationship of the maxilla and mandible before and after the distalization of the upper first molars using both(pendulum) and (2k-loop) distalization appliances. Materials and Methods: This study was designed as a retrospective study, The study sample included (12) patients from the archive of cases of the Department of Orthodontics and orthopedic - Tishreen University, who were treated using both pendulum  and 2k-loop distalization appliances, Changes were assessed using lateral cephalometric radiographs of the head. Results: The statistical program (SPSS ver.26. Chicago, IL, USA) was used to perform the necessary statistical analyses, a paired samples T-test was conducted for small independent samples, we obtained a significant decrease in the skeletal classification angel (ANB) by (0.41)°. Conclusions: Both distalization appliances were able to achieve a significant correction of Class II skeletal malocclusion dentally and skeletally, Which means directing the skeletal sagittal relationship of the maxilla and mandible towards first class relationship

Facial proportions in different mandibular rotations in class I individuals

The aims of this study were to evaluate facial proportions in different types of mandibular rotation using various parameters, to explore gender dimorphism within each type and to evaluate the correlation between the mandibular rotation measurements and the facial proportions.Lateral cephalograms of a total of 62 class I subjects (30 males and 32 female), aged between 18-25 years, were studied. The sample was divided into forward, normal, and backward rotation subgroups. Nine soft tissue facial proportions and five skeletal proportions were measured on lateral cephalometric radiographs. The facial proportions data were analyzed using independent sample Student t-test and Pearson correlation analysis. The backward rotation subjects showed the lowest value for the proportion of total posterior facial height (TPFH) and total anterior facial height (TAFH) and proportion of lower posterior facial height (LPFH) and TPFH and the highest value for the proportion of Sn-Pn./Stms-Sn., while forward rotation subjects exhibited the lowest value for proportion of upper posterior facial height (UPFH) and TPFH. Gender dimorphism was recorded; males showed higher value for the proportion of TPFH and TAFH, as well as for the proportion of Sn-Me\u27/G-Me\u27 and Me\u27-Stmi/Me\u27-Sn in the backward rotation group. All the skeletal facial proportions were found correlated with mandibular rotation measurements (NS-GoMe, B, FH-GoMe, Bjork) while only the soft tissue proportion for G-Sn/Sn-Me\u27, Sn-Me\u27/G-Me\u27 and G-Sn/G-Me\u27 were correlated with mandibular rotation measurements. The soft tissue drape particularly facial vertical dimensions are influenced by the underlying skeletal vertical pattern

The Impact of Applying Re-Engineering Application Process on Critical Performance Criteria in Jordanian Islamic Banks

Purpose: The importance of the study is that it provides an understanding of the management approach to re-engineering the application process in the banking industry to deal with significant and quick changes in the environment by implementing superior and radical changes that aid it in increasing its efficiency and lowering costs as well as in shifting the focus of employees to meet the needs and desires of customers by redesigning banking processes based on customer perceptions and needs, during the period 2019.   Theoretical Framework: The Study of the management method in re-engineering the application process in the banking sector to face the large and rapid changes in the environment is critical, as is shifting the focus of employees to meet the needs and desires of customers by redesigning the banking process based on customer perceptions and needs.   Design/methodology/approach: All three Jordanian Islamic banks comprise the study's study community, and the study's sample includes sixty-three (63) members of these banks' managerial ranks. The study used a questionnaire to gather data and analytical methodology, which helped explain the study problem.   Findings: After conducting the analysis process of the study data and hypotheses, Findings show There is a statistically significant influence of the application of the re-engineering process (redesigning jobs, redesigning process, reducing control levels, using new technology, empowering employees) on performance criteria  (costs, quality, speed ) in Jordanian Islamic banks.  Research, Practical & Social implications: To identify and analyze the re-engineering application process in Jordanian Islamic banks. The following elements are part of the study methodology: Cost, Quality, and Speed are the dependent variables in the crucial performance criteria; the study relied on choosing the dependent variables according to the objectives that re-engineering the application process can accomplish. Application re-engineering process dimensions, such as redesigning jobs and processes redesign, reducing control levels, using new technology, and empowering employees act as independent variables.   Originality/value: The Study recommends additional future research that could involve all levels of bank management in the re-engineering process and create an effective technology infrastructure and communication system that effectively contributes to the success of the re-engineering process

تقييم قابلية تطبيق مشعر بونت على عينة من جامعة تشرين

أولت العديد من المشعرات أهميّة لدراسة عرض القوس السنية وتحديد خصائصها ومنها مشعر بونت. لكن أشارت الدراسات إلى وجود اختلافات عرقية بين الشعوب, الأمر الذي طرح العديد من التساؤلات حول مدى قابلية تطبيق هذه المشعرات كمشعر بونت. هدف البحث: التحقق من قابلية تطبيق مشعر بونت كوسيلة موثوقة من وسائل التشخيص التقويمي. المواد والطرق: تضمنت عينة الدراسة 100 مثال جبسي لمرضى في مرحلة الإطباق الدائم ذوي إطباق طبيعي. النتائج: أظهرت النتائج وجود قيم معامل ارتباط منخفضة بين القيم المقاسة والمحسوبة حسب معادلة بونت  في كل الحالات. الاستنتاجات: لا يمكن اعتماد مشعر بونت كأداة موثوقة للتنبؤ بعرض القوس السنية المثالي في مجتمع الدراسة

تقييم قابلية تطبيق مشعر بونت على عينة من جامعة تشرين

أولت العديد من المشعرات أهميّة لدراسة عرض القوس السنية وتحديد خصائصها ومنها مشعر بونت. لكن أشارت الدراسات إلى وجود اختلافات عرقية بين الشعوب, الأمر الذي طرح العديد من التساؤلات حول مدى قابلية تطبيق هذه المشعرات كمشعر بونت. هدف البحث: التحقق من قابلية تطبيق مشعر بونت كوسيلة موثوقة من وسائل التشخيص التقويمي. المواد والطرق: تضمنت عينة الدراسة 100 مثال جبسي لمرضى في مرحلة الإطباق الدائم ذوي إطباق طبيعي. النتائج: أظهرت النتائج وجود قيم معامل ارتباط منخفضة بين القيم المقاسة والمحسوبة حسب معادلة بونت  في كل الحالات. الاستنتاجات: لا يمكن اعتماد مشعر بونت كأداة موثوقة للتنبؤ بعرض القوس السنية المثالي في مجتمع الدراسة

Developing a long-term follow up service for bariatric surgical patients in the community: patient and professional perspectives

Background In the UK, bariatric surgical patients are followed up for 2 years post-operatively in hospital settings, before being discharged into General Practice for long-term follow-up. Presently, there is ambiguous guidance as to what should be included in a community-based bariatric surgical follow-up service. The aim of the study was to understand, from both patient and professional perspectives, what is needed to support the long-term management of bariatric surgical patients in community-based settings. Methods Post-surgical bariatric patients and General Practice staff were recruited from an area in the UK which has an NHS hospital providing a high-volume and established bariatric surgical service. Data was collected through semi-structured interviews. A thematic analytic framework was used to construct eight themes which illuminated the participants’ experiences. The study took place between March – December 2021. Findings Thirty participants (14 patients and 16 healthcare professionals) were recruited to the study. The study revealed the lack of a framework for delivery of a long-term follow up service was frustrating to both patients and professionals. Patient participants reported needing more support, especially dietetic and psychological input, and professionals stated they had little knowledge about bariatric surgical care, and what was needed to provide optimal care, but wanted to provide quality patient care. Conclusion Long-term follow up of bariatric surgical patients is an important issue which needs addressing. This study illuminates both the patient and professional perspectives on developing a pragmatic, community-based service which meets the needs of patients and considers the need to incorporate such a service into existing infrastructures without adding additional demands on General Practice

Iron acquisition in Bacillus cereus: the roles of IlsA and bacillibactin in exogenous ferritin iron mobilization

9siIn host-pathogen interactions, the struggle for iron may have major consequences on the outcome of the disease. To overcome the low solubility and bio-availability of iron, bacteria have evolved multiple systems to acquire iron from various sources such as heme, hemoglobin and ferritin. The molecular basis of iron acquisition from heme and hemoglobin have been extensively studied; however, very little is known about iron acquisition from host ferritin, a 24-mer nanocage protein able to store thousands of iron atoms within its cavity. In the human opportunistic pathogen Bacillus cereus, a surface protein named IlsA (Iron-regulated leucine rich surface protein type A) binds heme, hemoglobin and ferritin in vitro and is involved in virulence. Here, we demonstrate that IlsA acts as a ferritin receptor causing ferritin aggregation on the bacterial surface. Isothermal titration calorimetry data indicate that IlsA binds several types of ferritins through direct interaction with the shell subunits. UV-vis kinetic data show a significant enhancement of iron release from ferritin in the presence of IlsA indicating for the first time that a bacterial protein might alter the stability of the ferritin iron core. Disruption of the siderophore bacillibactin production drastically reduces the ability of B. cereus to utilize ferritin for growth and results in attenuated bacterial virulence in insects. We propose a new model of iron acquisition in B. cereus that involves the binding of IlsA to host ferritin followed by siderophore assisted iron uptake. Our results highlight a possible interplay between a surface protein and a siderophore and provide new insights into host adaptation of B. cereus and general bacterial pathogenesis.openopenSegond D; Abi Khalil E; Buisson C; Daou N; Kallassy M; Lereclus D; Arosio P; Bou-Abdallah F; Nielsen Le Roux C.Segond, D; Abi Khalil, E; Buisson, C; Daou, N; Kallassy, M; Lereclus, D; Arosio, Paolo; Bou Abdallah, F; Nielsen Le Roux, C

Pengaruh Penambahan Kolin Klorida Pada Pakan Terhadap Kadar Kolesterol Dan Lipoprotein Darah Sapi Perah Laktasi

The purpose of this study was to evaluate the effects of choline chloride addition in feed on cholesterol, low density lipoprotein (LDL), and high density lipoprotein (HDL) levels in blood of lactating dairy cow, as indicator of lipid anabolism in the body. Eight of lactating dairy cows (61 to 91 days in milk; 2nd lactation period and 456 ± 31 kg of BW average as equal to 99 ± 5 kg BW0.75) were fed total mixed diet containing Napier grass and concentrate (40:60) and additive 30 g/d choline chloride 60% corn-cob as 18 g/d choline chloride (as equal to 0.02 % BW0.75). The experiment was set as cross-over designs with two experiments and eight replications. The treatments were T0 = 0 g/d choline chloride and T1= 30 g/d choline chloride, within 2 periods in which each period was 4 weeks and the data was analyzed using analysis of variance (ANOVA). The results showed that the addition of 30 g/d choline chloride in feed did not affect (P>0,05) the cholesterol, LDL and HDL levels in blood of lactating dairy cows. The conclusion of this study was the choline chloride addition in feed did not increase cholesterol, LDL, and HDL levels in blood of lactating dairy cows as the indicator of lipid anabolism

Cancer immunotherapy: A comprehensive appraisal of its modes of application.

peer reviewedConventional cancer treatments such as chemotherapy and radiation therapy have reached their therapeutic potential, leaving a gap for developing more effective cancer therapeutics. Cancer cells evade the immune system using various mechanisms of immune tolerance, underlying the potential impact of immunotherapy in the treatment of cancer. Immunotherapy includes several approaches such as activating the immune system in a cytokine-dependent manner, manipulating the feedback mechanisms involved in the immune response, enhancing the immune response via lymphocyte expansion and using cancer vaccines to elicit long-lasting, robust responses. These techniques can be used as monotherapies or combination therapies. The present review describes the immune-based mechanisms involved in tumor cell proliferation and maintenance and the rationale underlying various treatment methods. In addition, the present review provides insight into the potential of immunotherapy used alone or in combination with various types of therapeutics