Influence of Selective Carbon 1s Excitation on Auger-Meitner Decay in the ESCA Molecule.

Two-dimensional spectral mapping is used to visualize how resonant Auger-Meitner spectra are influenced by the site of the initial core-electron excitation and the symmetry of the core-excited state in the trifluoroethyl acetate molecule (ESCA). We observe a significant enhancement of electron yield for excitation of the COO 1s → π* and CF3 1s → σ* resonances unlike excitation at resonances involving the CH3 and CH2 sites. The CF3 1s → π* and CF3 1s → σ* resonance spectra are very different from each other, with the latter populating most valence states equally. Two complementary electronic structure calculations for the photoelectron cross section and Auger-Meitner intensity are shown to effectively reproduce the site- and state-selective nature of the resonant enhancement features. The site of the core-electron excitation and the respective final state hole locality increase the sensistivity of the photoelectron signal at specific functional group sites. This showcases resonant Auger-Meitner decay as a potentially powerful tool for selectively probing structural changes at specific functional group sites of polyatomic molecules.

The impact of environmentally friendly supramolecular coordination polymers as carbon steel corrosion inhibitors in HCl solution: synthesis and characterization.

Two 3D-supramolecular coordination polymers (SCP1 & SCP2) have been synthesized and characterized by physicochemical and spectroscopic methods. In a solution of 1.0 M HCl, SCPs were used to prevent corrosion of carbon steel (CS). The inhibition productivity (%η) rises as the synthetic inhibitor dose rises, and the opposite is true as the temperature rises. The study was carried out using chemical (mass loss, ML) and electrochemical ( potentiodynamic polarization, PDP and electrochemical impedance microscopy, EIS) techniques, which showed %η reached to 93.1% and 92.5% for SCP1 & SCP2, respectively at 21 × 10-6 M, 25 °C. For the polarization results, SCPs behave as mixed-type inhibitors. With increasing doses of SCPs, the charge transfer resistance grew and the double layer's capacitance lowered. The creation of a monolayer on the surface of CS was demonstrated by the finding that the adsorption of SCPs on its surface followed the Henry adsorption isotherm. The parameters of thermodynamics were computed and explained. The physical adsorption of SCPs on the surface of CS is shown by the lowering values of free energy (∆Goads < - 20 kJ mol-1) and increasing the activation energy (E*a) values in presence of SCP1 & SCP2 than in their absence. Atomic force microscope (AFM) and scanning electron microscopy (SEM) demonstrated the development of a protective thin film of SCPs precipitated on the surface of CS. There is a strong matching between results obtained from experimental and theoretical studies. Results from each approach that was used were consistent.

Insights into the use of two novel supramolecular compounds as corrosion inhibitors for stainless steel in a chloride environment: experimental as well as theoretical investigation.

Novel supramolecular (SCPs) compounds such as: {[Ni (EIN)4(NCS)2]}, SCP1 and {[Co (EIN)4 (NCS)2]}, SCP2 have been studied using weight loss (WL) and electrochemical tests on the corrosion performance of stainless steel 304 (SS304) in 1.0 M hydrochloric acid (HCl) solution. The experimental results revealed that inhibition efficacy (η%) rises with increasing concentrations of SCPs and reached 92.3% and 89.6% at 16 × 10-6 M, 25 °C, from the WL method for SCP1 and SCP2, respectively. However, by raising the temperature, η% was reduced. Polarization measurements (PDP) showed that the SCPs molecules represent a mixed-type. The SCPs were adsorbed on a SS304 surface physically, and the Langmuir adsorption isotherm was found to govern the adsorption process. The determination of thermodynamic parameters was carried out at various temperatures. Quantum chemical calculations were calculated to prove the adsorption process of SCP components, using the molecular dynamics (MD) simulations and electron density map. The inhibition performance of SCPs for SS304 dissolution in an acidic medium was proved to be excellent through FT-IR and AFM analysis. The results obtained from all measurements exhibit a high level of agreement with each other.

Novel porphyrin derivatives as corrosion inhibitors for stainless steel 304 in acidic environment: synthesis, electrochemical and quantum calculation studies.

A Novel 5,10,15,20-tetra (thiophen-2-yl) porphyrin (P1) and 5,10,15,20-tetrakis (5-Bromothiophen-2-yl) porphyrin (P2) were successfully synthesized, and their chemical structures were proved based on its correct elemental analysis and spectral data (IR and 1H-NMR). These compounds were examined as corrosion inhibitors for stainless steel 304 (SS304) in 2 M HCl utilizing mass reduction (MR) and electrochemical tests at inhibitor concentration (1 × 10-6-21 × 10-6 M). The protection efficiency (IE %) was effectively enhanced with improving the concentration of investigated compounds and reached 92.5%, 88.5% at 21 × 10-6 M for P1 & P2, respectively and decreases with raising the temperature. Langmuir's isotherm was constrained as the best fitted isotherm depicts the physical-chemical adsorption capabilities of P1 & P2 on SS304 surface with change in ΔGoads = 22.5 kJ mol-1. According to the PDP data reported, P1 and P2 work as mixed find inhibitors to suppress both cathodic and anodic processes. Porphyrin derivatives (P1 & P2) are included on the surface of SS304, according to surface morphology techniques SEM/EDX and AFM. Quantum calculations (DFT) and Monte Carlo simulation (MC) showed the impact of the chemical structure of porphyrin derivatives on their IE %.

Nano-metal-organic frameworks as corrosion inhibitors for strengthening anti-corrosion behavior of carbon steel in a sulfuric acid environment: from synthesis to applications.

In order to demonstrate the effect of Nano-metal organic frameworks, [Cu2(CN)4(Ph3Sn) (Pyz2-caH)2] (NMOF1) and [∞3[Cu(CN)2(Me3Sn)(Pyz)]] (NMOF2) as corrosion inhibitors for C-steel in 0.5 M sulfuric acid solutions, the following methods were utilized: mass reduction (MR), potentiodynamic polarization (PDP), and AC electrochemical impedance (EIS). The results of the experiments showed that by increasing the dose of these compounds, the inhibition efficacy (η%) of C-steel corrosion increased and reached 74.4-90% for NMOF2 and NMOF1 at a dose of 25 × 10-6 M, respectively. On the other hand, the η% decreased as the temperature range rose. Parameters for activation and adsorption were determined and discussed. Both NMOF2 and NMOF1 were physically adsorbed on the surface of C-steel and conformed to the Langmuir adsorption isotherm model. The PDP studies revealed that these compounds functioned as mixed type inhibitors, i.e. affecting both metal dissolution and hydrogen evolution reactions. Attenuated Total Reflection Infra-Red (ATR-IR) analysis was carried out to determine the morphology of the inhibited C-steel surface. There is good agreement between the findings of EIS, PDP and MR.

Synthesis and characterization of novel acrylamide derivatives and their use as corrosion inhibitors for carbon steel in hydrochloric acid solution.

Two new acrylamide derivatives were prepared namely: "N-(bis(2-hydroxyethyl) carbamothioyl) acrylamide (BHCA) and N-((2-hydroxyethyl) carbamothioyl) acrylamide( HCA) and their chemical structures were analyzed and confirmed using IR and 1H NMR". These chemicals were investigated as corrosion inhibitors for carbon steel (CS) in 1 M HCl medium using chemical method (mass  loss, ML), and electrochemical techniques including potentiodynamic polarization (PDP), and electrochemical impedance spectroscopy (EIS). The results showed that the acrylamide derivatives work well as corrosion inhibitors, with inhibition efficacy (%IE) reaching 94.91-95.28% at 60 ppm for BHCA and HCA, respectively. Their inhibition depends mainly on their concentration and temperature of the solution. According to the PDP files, these derivatives function as mixed-type inhibitors that physically adsorb on the CS surface in accordance with the Langmuir adsorption isotherm, creating a thin coating that shields the CS surface from corrosive fluids. The charge transfer resistance (Rct) increased and the double layer capacitance (Cdl) decreased as a result of the adsorption of the used derivatives. Calculated and described were the thermodynamic parameters for activation and adsorption. Quantum chemistry computations and Monte Carlo simulations were examined and discussed for these derivatives under investigation. Surface analysis was checked using atomic force microscope (AFM). Validity of the obtained data was demonstrated by the confirmation of these several independent procedures.

Experimental and computational chemical studies on the corrosion inhibition of new pyrimidinone derivatives for copper in nitric acid.

Inhibition of copper corrosion by some pyrimidinone derivatives, namely; (E)-N-(3-((1,3-dimethyl-2,4,6-trioxohexahydropyrimidin-5-yl)diazenyl)-2,5-diethoxyphenyl)benzamide (MA-975) and(E)-6-(4-((4-chlorophenyl)diazenyl)-3-methyl-5-oxo-4,5-dihydro-1H-pyrazol-1-yl)-1,3 dimethylpyrimidine-2,4(1H,3H)-dione (MA-978C) in 1.0 M nitric acid (HNO3) was studied using weight loss (WL), electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization (PP) measurements. The efficiency of inhibition increases as the concentration of inhibitor increases, and it also increases as the temperature increases. With the addition of the examined inhibitors, significant corrosion protection was obtained, and (MA-975) showed a very promising % IE (89.59%) at 21 × 10-6 M using the (WL) method. The polarization data revealed that these compounds act as mixed-type compounds and are adsorbed on the copper surface following Langmuir adsorption isotherm forming a protective thin film protecting the metal in the corrosive media. Scanning electron microscopy (SEM) and Energy Dispersive X-ray were used to examine the surface morphology of copper samples. Quantum calculations and Monte Carlo simulation techniques were applied with informative yields and the results matched the experimental findings.

A randomized controlled trial comparing the effects of Vitamin E, Ursodeoxycholic acid and Pentoxifylline on Egyptian non-alcoholic steatohepatitis patients.

OBJECTIVE: Currently, no NASH-specific therapies are approved by the US Food and Drug Administration. This study aimed to compare the clinical effect of vitamin E (Vit. E), Ursodeoxycholic Acid (UDCA) and pentoxifylline (PTX) on Egyptian patients with NASH with exploration of their possible roles on inflammatory cytokines and chemokines mainly Interleukin 6 (IL6) and Monocyte Chemoattractant Protein-1 (CCL2/MCP-1). PATIENTS AND METHODS: We conducted a 3-month, randomized, single-blind study in 102 Egyptian NASH patients who were divided into three groups; group 1 received Vit. E 400 mg twice a day, group 2 received UDCA 250 mg twice a day and group 3 received PTX 400 mg twice daily. Liver aminotransferases (AST, ALT), IL6, CCL2/MCP-1, albumin, bilirubin, and lipid panel were measured both before and after intervention intake. RESULTS: A significant decrease was found in liver aminotransferases, serum cytokine and chemokine in participants after Vit. E, UDCA or PTX intake. Compared to the UDCA and PTX groups, liver aminotransferases, serum cytokine and chemokine showed a more statistically significant reduction after Vit. E administration (50%, 43%, 57% and 55% for ALT, AST, IL6 and CCL2/MCP-1, respectively). In contrast, other biochemical tests showed non-significant change after any drug intake. None of the tested drugs showed significant safety issues in this population. CONCLUSIONS: Treatment with Vit. E, UDCA and PTX was both safe and effective in improving hepatic aminotransferases and inflammatory markers in Egyptian NASH patients. The superior effect of Vit. E compared to UDCA and PTX may suggest that oxidative stress plays a key role in disease progression of NASH patients. Moreover, IL6 and CCL2/MCP-1 may be used with or without ALT for treatment evaluation of NASH people.

Ultrafast nonadiabatic dynamics probed by nitrogen K-edge absorption spectroscopy.

The emergence of X-ray free electron lasers (X-FELs) has made it possible to probe structural dynamics on the femtosecond timescale. This extension of experimental capabilities also calls for a simultaneous development in theory to help interpret the underlying structure and dynamics encoded within the experimental observable. In the ultrafast regime this often requires a time-dependent theoretical treatment that describes nuclear dynamics beyond the Born-Oppenheimer approximation. In this work, we perform quantum dynamics simulations based upon time-evolving Gaussian basis functions (GBFs) and simulate the ultrafast X-ray Absorption Near-Edge Structure (XANES) spectra of photoexcited pyrazine including two strongly coupled electronically excited states and four normal mode degrees of freedom. Two methods to simulate the excited state XANES spectra are applied, the first is based upon the multi-configurational second order perturbation theory restricted active space (RASPT2) method and the second uses a combination of the maximum overlap method (MOM) and time-dependent density functional theory (TDDFT). We demonstrate that despite the simplicity of the MOM/TDDFT method, it captures several qualitative features of the RASPT2 simulations at much reduced computational effort. However, features such as the conical intersection are a particular exception as they require a multi-configurational treatment. For the nuclear dynamics, we demonstrate that even a small number of GBFs can provide reasonable description of the spectroscopic observable. This work provides perspectives for computationally efficient approaches important for addressing larger systems.

3D hierarchical graphene/CNT with interfacial polymerized polyaniline nano-fibers.

In this work Polyaniline (PANI) fiber has been synthetized by the interfacial polymerization method. The thermal behavior of graphene - multiwall carbon nanotubes (MWCNs) composite material (C-Mix) blended with PANI fiber was investigated. Graphene was prepared by thermal reduction of the fabricated graphene oxide (GO) using modified Hummers' method. SEM measurement reveals that MWCNTs were well organized within 2D large surface area graphene nano-sheets to form 3D carbon-base hierarchical structure, and PANI was mixed as a binder polymer matrix. Structural measurements confirm the formation of wide area graphene sheets with crumples, wrinkles, and folds around the edges. Transmission electron microscopy (TEM) images agreed with the well distribution of CNTs within graphene nano-sheets. Also, the surface morphology of the synthesized composites has a spherical regular agglomeration of PANI granular structure on wide area graphene nano sheets with CNT embedded. The change in the existed phonon modes of the fabricated nano-composite was analyzed using Raman spectroscopy. Moreover, Seebeck coefficient changes from +132.4 µV/K to -10.3 µV/K after adding carbon-based materials which reflects the reverse of predominate carriers by doping PANI with carbon-based material. It has been noticed that there is an enhancement of thermal conductivity of the fabricated composite with respect to neat polymer. Hence, we propose that 3D carbon structure with PANI construct a stable N-Type thermoelectric material.

Change of site of intra-articular injection of hypertonic dextrose resulted in different effects of treatment.

Most minimally invasive treatments for dysfunction of the temporomandibular joint (TMJ) are empirical, and aimed at the painful trigger points with the purpose of preventing muscular spasm and restoring normal function. In this prospective study I investigated whether the choice of site of injection of hypertonic dextrose affected the benefits of treatment of internal derangement and pain. I studied 72 patients with pain and clicking as a result of dysfunction of the TMJ. Patients were divided into four groups with four separate sites for intra-articular injection. Dextrose was injected into the superior joint space, inferior joint space, retrodiscal tissue, and anterior capsule injection. Results showed that the retrodiscal site was the most effective for reducing clicking and subsequently improving derangement, while the inferior joint space was the best site for the relief of pain, and the extracapsular site should be used in cases of hypermobility. In conclusion, the injection site should be selected according to the symptoms being treated, and could be used as an adjunct to other sites to improve outcome.

Aspects cliniques et prise en charge des accidents de travail survenus en milieu industriel à Douala

Introduction : Les statistiques générales des accidents de travail sont en régression dans le monde, mais restent élevées dans les pays émergents et sous-développés. L'absence de données scientifiques locales sur les risques professionnels et la méconnaissance des caractéristiques générales des accidents de travail a motivé la conduite de cette étude dont l'objectif était de décrire les aspects cliniques et la prise en charge des accidents de travail survenus en milieu industriel à Douala au Cameroun entre 2000 et 2009.Méthodologie : L'étude était rétrospective et descriptive. Elle s'est déroulée du 25 mars au 23 mai 2014 dans les cinq centres de la Caisse Nationale de Prévoyance Sociale de Douala. Nous avons colligé tous les dossiers exploitables des victimes d'accidents de travail survenus en milieu industriel pendant la période 2000-2009. Les résultats ont été présentés sous forme univariée et bivariée. Résultats : Mille soixante-quatre (1064) cas ont été retenus sur les 1471 dossiers étudiés (72,33%). L'échantillon était à prédominance masculine et la moyenne d'âge était de 35,7± 7,41 ans. La majorité des victimes était des ouvriers (54,4%). Ils travaillaient dans les industries du secteur du bois (38,3%) ou du secteur du pétrole, gaz et chimie. La majorité des lésions était légère et modérée (53,20%), localisées aux mains (35,8%), aux membres inférieurs (17,6%) et aux yeux (13,2%). Il s'agissait de lésions cutanéo-muqueuses ou ostéo-articulaires. Les victimes avaient reçu des premiers soins, dans 74,10% dans des formations sanitaires situées hors de l'entreprise. La majorité des victimes (51,8%) avait effectué des examens radiographiques exploratoires, 47,2% avaient été consultées par des médecins et 313 victimes avaient été hospitalisées pendant 1 à 2 jours (56,5%), 88 victimes pendant 3-7 jours (28,3%) et 48 victimes pendant plus de 7 jours (15,2%). La quasi-totalité des victimes a eu un arrêt de travail avec ITT supérieure à 7 jours (64,5%). Sept-cent-cinquante-deux victimes ont guéri (70,70%) et 237 (22,30%) ont consolidé. Conclusion : Les victimes d'accidents de travail à Douala pour la période 2000-2009 sont des jeunes ouvriers travaillant dans l'industrie du bois, du pétrole, gaz et chimie et de la métallurgie. La prise en charge a étéeffectuée en dehors de l'entreprise et met en exergue les difficultés fonctionnelles des centres médicaux d'entreprise

Photo-Response of Functionalized Self-Assembled Graphene Oxide on Zinc Oxide Heterostructure to UV Illumination.

Convective assembly technique which is a simple and scalable method was used for coating uniform graphene oxide (GO) nanosheets on zinc oxide (ZnO) thin films. Upon UV irradiation, an enhancement in the on-off ratio was observed after functionalizing ZnO films by GO nanosheets. The calculations of on-off ratio, the device responsivity, and the external quantum efficiency were investigated and implied that the GO layer provides a stable pathway for electron transport. Structural investigations of the assembled GO and the heterostructure of GO on ZnO were performed using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The covered GO layer has a wide continuous area, with wrinkles and folds at the edges. In addition, the phonon lattice vibrations were investigated by Raman analysis. For GO and the heterostructure, a little change in the ratio between the D-band and G-band was found which means that no additional defects were formed within the heterostructure.

[Epidemiologiy of obesity among university students in Douala, Cameroon]. / Épidémiologie de l'obésité en milieu estudiantin à Douala, Cameroun.

PURPOSE: To determine the prevalence of obesity, its risk factors, and its health risks among students of the University of Douala. METHODS: In April, 2011, 2696 students volunteered to participate in a screening campaign for diabetes, high blood pressure (HBP), and obesity. Their physical activity (PA) level was also evaluated. RESULTS: The sample consisted of 1276 (47.3%) men and 1420 (52.7%) women with a mean age of 23.8 ± 3.5 years. The general prevalence of obesity was 4.1%, and it was more common among women (p = 0.043). The age group most highly affected was those 35 years or older, with a prevalence of 39.5% (p<0.02). Among the obese, the risk level was high in 78 (70.9%) women. The prevalence of HBP was higher among obese than non-obese students (20.9% vs. 12.5%, p = 0.019), and the prevalence of diabetes five times higher (4.5% vs. 0.8%, p = 0.003). Obesity was highly associated with alcohol consumption (p = 0.01), physical inactivity (p = 0.007), and family history of diabetes (p = 0.008). CONCLUSION: Obesity is a worrisome disorder among students in Douala. Educating students about this topic and developing an obesity prevention and management program may improve their health.

Influence of homo buffer layer thickness on the quality of ZnO epilayers.

ZnO buffer layers with different thicknesses were deposited on a-plane sapphire substrates at 300 °C. ZnO epilayers were grown on ZnO buffers at 600 °C by radio-frequency magnetron sputtering and vacuum annealed at 900 °C for an hour. Influence of nucleation layer thickness on the structural and quality of ZnO thin films was investigated using X-ray diffraction (XRD), atomic force microscopy (AFM), and Raman spectroscopy. The best ZnO film quality was obtained with the ZnO buffer layer of 45 nm thick which provided the smoothest surface with RMS value of 0.3 nm. X-ray diffraction measurements reveal that the films have a single phase wurtzite structure with (0001) preferred crystal orientation. As evident from narrow FWHM of ZnO (0002) rocking curve, ZnO buffer can serve as a good template for the growth of high-quality ZnO films with little tilt. In addition, the micro-Raman scattering measurements at room temperature revealed the existence of Raman active phonon modes of ZnO; A1(TO), A1(LO) and E2(high). The latter two modes were not observed in thin buffer layer beside the dis-appearance of E2(low) mode in all films.

Imbalance of the nerve growth factor and its precursor as a potential biomarker for diabetic retinopathy.

Our previous studies have demonstrated that diabetes-induced oxidative stress alters homeostasis of retinal nerve growth factor (NGF) resulting in accumulation of its precursor, proNGF, at the expense of NGF which plays a critical role in preserving neuronal and retinal function. This imbalance coincided with retinal damage in experimental diabetes. Here we test the hypothesis that alteration of proNGF and NGF levels observed in retina and vitreous will be mirrored in serum of diabetic patients. Blood and vitreous samples were collected from patients (diabetic and nondiabetic) undergoing vitrectomy at Georgia Regents University under approved IRB. Levels of proNGF, NGF, and p75(NTR) shedding were detected using Western blot analysis. MMP-7 activity was also assayed. Diabetes-induced proNGF expression and impaired NGF expression were observed in vitreous and serum. Vitreous and sera from diabetic patients (n = 11) showed significant 40.8-fold and 3.6-fold increases, respectively, compared to nondiabetics (n = 9). In contrast, vitreous and sera from diabetic patients showed significant 44% and 64% reductions in NGF levels, respectively, compared to nondiabetics. ProNGF to NGF ratios showed significant correlation between vitreous and serum. Further characterization of diabetes-induced imbalance in the proNGF to NGF ratio will facilitate its utility as an early biomarker for diabetic complications.

Factors influencing parental consent for participation in clinical research involving their children in Egypt.

Factors affecting parents' decision to involve their children in clinical research have not been studied in all cultural backgrounds. We aimed to explore the attitudes and beliefs influencing parents' decision to involve their children in clinical research in Mansoura, Egypt. Of 523 families approached, 357 filled the questionnaire. Only 98 (27.5%) parents consented to involve their child in clinical research. The children of consenters were significantly older than refusers: 8.6 (SD 7.2) versus 2.6 (SD 1.2) years. Factors favouring consent were: research of benefit to child (84.7%), enough explanation about the benefits (40.8%) and to learn more about child's condition (29.6%). Factors favouring refusal were: use of new drugs or vaccines (89.6%) and invasive procedures (84.2%). Parents' rate of consent was positively correlated with the research being non-invasive and the belief that research was of benefit to their child and negatively correlated with belief that refusal may negatively affect the care provided to their child.

Factors influencing parental consent for participation in clinical research involving their children in Egypt

Factors affecting parents' decision to involve their children in clinical research have not been studied in all cultural backgrounds.We aimed to explore the attitudes and beliefs influencing parents' decision to involve their children in clinical research in Mansoura, Egypt.Of 523 families approached, 357 filled the questionnaire.Only 98 [27.5%]parents consented to involve their child in clinical research.The children of consenters were significantly older than refusers:8.6 [SD 7.2]versus 2.6 [SD 1.2]years.Factors favouring consent were:research of benefit to child [84.7%], enough explanation about the benefits [40.8%]and to learn more about child's condition [29.6%]. Factors favouring refusal were:use of new drugs or vaccines [89.6%]and invasive procedures [84.2%]. Parents' rate of consent was positively correlated with the research being non-invasive and the belief that research was of benefit to their child and negatively correlated with belief that refusal may negatively affect the care provided to their child

لم تخضع العوامل التي تؤثر على موافقة الوالدين على إشراك أطفالهم في البحوث السريرية، للدراسة في جميع الخلفيات الثقافية. وهدف الباحثون إلى التعرف على المواقف والمعتقدات التي تؤثر على القرارات التي يتخذها الوالدان حول مشاركة أطفالهم في البحوث السريرية في المنصورة في مصر. وقد تواصل الباحثون مع 523 أسرة، استكملت الاستبيانات منها 357 أسرة، واتضح أن 98 من الوالدين [27.5%]، فقط قد وافقوا على مشاركة أطفالهم في البحوث السريرية، وأن متوسط أعمار الأطفال الذين وافق الوالدان على مشاركتهم بالبحوث وهو 8.6 عاما [7.2 +/- ] أكبر بمقدار يعتد به إحصائيا من متوسط أعمار الأطفال الذين رفض الوالدان مشاركتهم بها وهو 2.6 عاما [1.2 +/- ]، وأن العوامل التي ترجح الموافقة هي:البحوث التي تعود بالنفع على الطفل [84.7 %]والشرح الوافي عن المنافع [40.8%]والتعلم أكثر عن حالة الطفل [29.6 %]أما العوامل التي ترجح رفض الموافقة فهي: استخدام أدوية أو لقاحات جديدة [89.6%]، والإجراءات الباضعة [84.2 %]. وكان هناك ترابطا إيجابي بين معدل موافقة الوالدين مع كون البحوث غير باضعة وكذلك مع الاعتقاد بأن البحوث نافعة لطفلها، وكان هناك ترابط سلبي مع الاعتقاد بأن رفض المشاركة قد يؤثر سلبيا على الرعاية التي تقدم لطفلها

Les facteurs influant sur la décision des parents de laisser leur enfant participer à une étude de recherche clinique n'ont pas été étudiés dans tous les contextes culturels.L'objectif de 'étude était d'examiner les attitudes et les croyances influant sur la décision des parents de laisser participer leur enfant à une étude de recherche à Mansoura [Egypte]. Sur 523 familles contactées, 357 ont rempli le questionnaire.Seuls 98 parents [27, 5 %]consentaient à laisser participer leur enfant a une recherche clinique.Les enfants des parents qui avaient donné leur consentement étaient nettement plus âgés que ceux dont les parents avaient refusé:8, 6 ans [ET 7, 2]contre 2, 6 ans [ET 1, 2]. Les facteurs favorisant le consentement étaient les suivants:une recherche bénéfique pour l'enfant [84, 7 %], des explications suffisantes sur les avantages [40, 8 %]et l'occasion de mieux connaitre l'affection de leur enfant [29, 6%]. Les facteurs favorisant le refus étaient les suivants:l'utilisation de nouveaux médicaments ou vaccins [89, 6 %]et des actes invasifs [84, 2 %]. Le taux de consentement des parents était positivement corrélé à une recherche non invasive et à la croyance que la recherche serait bénéfique pour leur enfant, et négativement corrélé à la croyance selon laquelle un refus pourrait négativement influer sur les soins fournis à leur enfant