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Mechanism of Silver Nanoparticles Deposition by Electrolysis and Electroless Methods on a Graphite Substrate

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International Journal of Nonferrous Metallurgy 2022年第1期10卷 1-14页

作者： Mahmoud A. Rabah Nabil nassif Girgis Chemocal and Electrochemical Treatment Lab. Mineral Processing Dept. Central Metallurgical Research and Development Institute (CMRDI) El-Flezzat Str. El-Tebbin Cairo Egypt Control and Surface Protection Lab (CMRDI) El-Flezzat Str. El-Tebbin Cairo Egypt

This study shows a silver electrodeposition model (EDM) on a graphite substrate. The electrolyte was a 0.01 M solution of pure silver and chromium nitrate using an electrolyzing cell. EDC with current density up to 20 mA/cm2 and 15 mV and pulse current were studied. Results revealed that silver deposited at a rate of 0.515 mg/cm2/min with 12 mA/cm2 that decreases to 0.21 and 0.16 mg/cm2·min with the decrease of current density to 6 and 5 mA/cm2 respectively. The model postulates that silver ions (a) were first hydrated before diffusing (b) from the solution bulk to the cathode vicinity, The next step (c) involved the chemical adsorption of these ions on certain accessible sites of the graphite substrate (anode), The discharged entities (d) adhere to the graphite surface by Van der Vales force. Silver ions are deposited because the discharge potential of silver is low (0.38 mV) as compared to other metal ions like chromium (0.82 mV). Pulse current controls silver deposition due to flexibility in controlling steps (a)-(c) of the deposition mechanisms. Parameters like current density, current on-time, current-off time, duty cycle (ratio of current on time and total pulse time) and pulse frequency influenced the shape and size of the deposits. Step (b) suggested that silver particles were deposited in a monolayer thickness. The silver layer turned multiple after fully satisfying the accessible sites with the monolayer. The activation energy ΔE value amounts to 86.32 kJ/mol/K. At high temperature and current density, homogeneous diffusion occurs.

关键词： Silver and Chromium Nanoparticles Electrolysis Electroless Deposition Chemical Deposition and Pulse Current Graphite Substrate

Clinical and cost impact of intravenous proton pump inhibitor use in non-ICU patients

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World Journal of Gastroenterology 2010年第8期16卷 982-986页

作者： Soumana C Nasser Jeanette G nassif Hani I Dimassi Department of Pharmacy Practice School of PharmacyLebanese American University

AIM:To assess the appropriateness of the indication and route of administration of proton-pump-inhibitors (PPIs) and their associated cost impact. METHODS:Data collection was performed prospec-tively during a 6-mo period on 340 patients who re-ceived omeprazole intravenously during their hospital stay in non-intensive care floors. Updated guidelines were used to assess the appropriateness of the indication and route of administration. RESULTS:Complete data collection was available for 286 patients which were used to assess intravenous (IV) PPIs utilization. Around 88% of patients were receiving PPIs for claimed stress ulcer prophylaxis (SUP) indication; of which,only 17% met the guideline criteria for SUP indication,14% met the criteria for non-steroidal-anti-inflammatory drugs-induced ulcer prophylaxis,while the remaining 69% were identifi ed as having an unjustified indication for PPI use. Theinitiation of IV PPIs was appropriate in 55% of pa-tients. Half of these patients were candidates for switching to the oral dosage form during their hos-pitalization,while only 36.7% of these patients were actually switched. The inappropriate initiation of PPIs via the IV route was more likely to take place on the medical floor than the surgical floor (53% vs 36%,P = 0.003). The cost analysis associated with the appro-priateness of the indication for PPI use as well as the route of administration of PPI revealed a possible saving of up to $17 732.5 and $14 571,respectively. CONCLUSION:This study highlights the over-utili-zation of IV PPIs in non-intensive care unit patients. Restriction of IV PPI use for justified indications and route of administration is recommended.

关键词： Cost saving Lebanon Non-intensive care unit patients Omeprazole Over-utilization Proton-pump-inhibitors Stress ulcer prophylaxis

Video capsule endoscopy in left ventricular assist device recipients with obscure gastrointestinal bleeding

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World Journal of Gastroenterology 2016年第18期22卷 4559-4566页

作者： Surachai Amornsawadwattana Michael nassif David Raymer Shane La Rue Chien-Huan Chen Department of Internal Medicine Washington University School of Medicine Division of Cardiology Washington University School of Medicine Division of Gastroenterology Washington University School of Medicine

AIM: To assess whether video capsule endoscopy (VCE) affects the outcomes of left ventricular assist devices (LVADs) recipients with gastrointestinal ***: This is a retrospective study of LVAD recipients with obscure gastrointestinal bleeding (OGIB) who underwent VCE at a tertiary medical center between 2005 and 2013. All patients were admitted and monitored with telemetry and all VCE and subsequent endoscopic procedures were performed as inpatients. A VCE study was considered positive only when P2 lesions were found and was regarded as negative if P1 or P0 were identified. All patients were followed until heart transplant, death, or the end of the ***: Between 2005 and 2013, 30 patients with LVAD underwent VCE. Completion rate of VCE was 93.3% and there was no capsule retention. No interference of VCE recording or the function of LVAD was found. VCE was positive in 40% of patients (n = 12). The most common finding was active small intestinal bleeding (50%) and small intestinal angiodysplasia (33.3%). There was no difference in the rate of recurrent bleeding between patients with positive and negative VCE study (50.0% vs 55.6%, P = 1.00) during an average of 11.6 ± 9.6 mo follow up. Among patients with positive VCE, the recurrent bleeding rate did not differ whether subsequent endoscopy was performed (50% vs 50%, P = 1.00).CONCLUSION: VCE can be safely performed in LVAD recipients with a diagnostic yield of 40%. VCE does not affect recurrent bleeding in LVAD patients regardless of findings.

关键词： Heart-assist devices Capsule endoscopy Gastrointestinal hemorrhage Heart failure Endoscopy Digestive system

Systematic review of anorectal leiomyosarcoma: Current challenges and recent advances

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World Journal of Gastrointestinal Surgery 2019年第8期11卷 334-341页

作者： Mohammed O nassif Razan A Habib Luai Z Almarzouki Nora H Trabulsi Department of Surgery King Abdulaziz University

BACKGROUND The anorectal leiomyosarcoma (LMS) is an aggressive malignant neoplasm. Owing to the rarity of LMSs, an optimal treatment modality has yet to be determined. AIM To collect all published data on anorectal LMS characteristics, explore current treatment options, and review recent cases of postradiation LMS. METHODS A literature search of the PubMed electronic database was conducted using the MeSH terms "rectal neoplasms","anus neoplasms" and "gastrointestinal neoplasms" combined with "leiomyosarcoma". The search was limited to English language and human studies. All available case reports and case series of anal or rectal LMSs that were published from the beginning of January 1996 to May 2017 were included if the diagnosis of LMS had been confirmed by histopathologic examination. Data were analyzed using simple statistics (mean, median, and standard deviation). Independent sample t-test was used to compare means for continuous variables. RESULTS A total of 27 articles reporting on 51 cases of anorectal LMS were identified. Among these cases, 11.7% had undergone previous pelvic radiotherapy (developing LMS at 13-35 years afterwards). Anorectal LMS affected the rectum in 92.2% of the cases, and no sex-based predominance was observed. Surgical resection with negative margins remains the mainstay of treatment, which can be accomplished with wide local excision or radical resection. The local recurrence rate was higher among cases who received wide local excision (30%), as compared to radical resection (20%);however, the overall rate of metastasis was 51.61% regardless of the treatment approach. The use of neoadjuvant radiation lowers the risk of local recurrence compared to adjuvant radiotherapy, and facilitates R0 resection of the tumor. Cases treated with adjuvant chemotherapy showed better rates of distant recurrence and overall survival. Nonetheless, multidisciplinary team discussion is necessary to determine the optimal management plan whilst considering pa

关键词： Leiomyosarcoma Rectal neoplasms Anal neoplasms Gastrointestinal neoplasms Soft tissue neoplasms

Influence of production processes in quality of fermented milk "Laban"in Lebanon

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Health 2010年第4期2卷 381-389页

作者： Zeineddine Mayssoun nassif Nadine 不详

Yoghurt (Laban) is one of the most consumed food products in Lebanon. Thus its quality has given a concern. In this study, the sensory, chemical and rheological properties of commercial and traditional samples were investigated in order to characterize this fermented milk. Hence, Laban samples were collected from 14 areas in Lebanon;especially from mountainous regions and from the capital Beirut. Forty-two samples were provided by processing industry whether at small, medium, or large scale. A statistical analysis was carried out, and thus sensory and physicochemical properties were subjected to two approaches of variance analysis. Pearson correlation coefficients between attributes were also calculated. Both, the analyses of variance and correlations were conducted using SPSS 3. The physicochemical analysis and the microbiological analysis exhibit a significant effect of the date, and the manufacturing process. Also, the instrumental data showed no significant correlation between physicochemical and microbiological parameters, which indicates that they are completely independent. Moreover, the general appreciation of descriptive sensory analysis of products display that this appreciation is not dependant on the production process. It is also noticed that some sensory characteristics can be dread by instrumental measures. This research endorses the essential role of quality control for the manufacturing of yoghurt in Lebanon.

关键词： Laban Rheology Manufacturing Process Sensory Analysis Lebanon

Studying Heavy Metals in Sediments Layers along Selected Sites on the Lebanese Coast

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Journal of Water Resource and Protection 2010年第1期2卷 48-60页

作者： Nadine nassif Ziad SAADE 不详

Ensuring the environmental protection of the Lebanese coast requires a continues monitoring system. For this purpose, four heavy metals (Fe, Mn, Cu and Pb in the marine sediments along the Lebanese coast were selected for analysis Sampling was carried out from two sites: Beirut and Batroun. Thus, 1g of dried sample is used for digestion by wet mineralization in order to determine the concentration of the four heavy metals by atomic absorption spectrometry. The results showed that Beirut area is polluted, by Fe and Mn as well as the station Bat 2 of Batroun. For Cu and Pb, Batroun region is more polluted in the superficial layers. The analysis also showed significant difference between the sites except for Cu. A difference between depths and between particles size fractions are observed for all the parameters studied. There is no a significant difference in layer sequence except for the Pb, and neither between the repetitions of the same sample. Results showed that the values of the four metals studied do not exceed the maximum limits at both sites, but they showed increase in comparison with the analyses obtained before July 2006 conflict, which was caused by the release of large quantity of fuel-oil from Jiyeh Power Station.

关键词： Pollution Sediments Heavy metals Coast Lebanon

Induction of labor using double balloon cervical device in women with previous cesarean section: Experience and review

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Open Journal of Obstetrics and Gynecology 2013年第2期3卷 301-305页

作者： E. Ebeid N. nassif Department of Obstetrics and Gynaecology St Mary’s Hospital Newport UK

Induction of labour remains one of the most challenging interventions in current obstetrics. Different pharmaceuticals have been used for cervical ripening such as prostaglandins;however they can lead to a number of potential inconvenient risks namely uterine tachysystole and pathological fetal cardiotocography (CTG). In cases of women with previous caesarean births, using prostaglandins would pose even higher risks such as uterine rupture and perinatal mortality. A mechanical method of cervical ripening could represent an alternative for these women. We report the use of the extra-amniotic double balloon cervical device (Cook’s device) for ripening of unfavourable cervix in seventeen women attempting vaginal birth after cesarean section (VBAC). Using Bishop scoring system to assess cervical dilatetion, position, consistency, fetal station and effacement, the unfavourable cervix is the cervix that scores less than 6. We review the relevant literature discussing this method of induction focusing on its effectiveness, simplicity, safety and efficacy, low cost and any associated serious side effects. Conclusion: Success was estimated to be over 50% with no serious life threatening maternal or fetal complications. We considered the process satisfactory and practical. We recommend larger studies to assess safety and efficacy of Cook’s device in vaginal birth after caesarean section before embarking on routine elective caesarean delivery. Objectives: To estimate success rate for vaginal delivery after previous caesarean section using cervical double balloon device (Cook’s device). Design: Three-year observational study. Setting: Maternity unit in district general hospital, UK. Population: Women who had one previous lower segment caesarean section and unfavourable cervix identified as having Bishop Score less than 6. Methods: Data were obtained from the birth registry over 3 years from January 2008 until December 2010. Main outcome: Measure successful vaginal delivery. Res

关键词： Labour Induction Cervical Balloon Cook Balloon Double Balloon Cesarean Section

Energy Performance Analysis of Ice Thermal Storage for Commercial HVAC Systems

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Journal of Energy and Power Engineering 2013年第9期7卷 1713-1718页

作者： Nabil nassif Raymond Tesiero Nihal AI Raees Department of Civil and Architeetural Engineering North Carolina A & T State University Greensboro NC 27411 USA

Ice thermal storage is a promising technology to reduce energy costs by shifting the cooling cost from on-peak to off-peak periods. The paper investigates the application of ice thermal storage and its impact on energy consumption, demand and total energy cost. Energy simulation software along with a chiller model is used to simulate the energy consumption and demand for the existing office building located in central Florida. Furthermore, the study presents a case study to demonstrate the cost saving achieved by the ice storage applications. The results show that although the energy consumption may increase by using ice thermal storage, the energy cost drops significantly, mainly depending on the local utility rate structure. It found that for the investigated system the annual energy consumption increases by about 12% but the annual energy cost drops by about 3 6%.

关键词： HVAC system ice thermal storage central plant chiller.

使用OCT评估中心性浆液性脉络膜视网膜病变患者脉络膜厚度的变化

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国际眼科杂志 2020年第4期20卷 583-588页

作者： Ragai Magdy Hatata Mohamed Abdelhamid nassif Sherin Hassan Sadek 法雍大学眼科埃及法雍11435

目的:使用光谱域光学相干断层成像(SD-OCT)技术研究中心性浆液性脉络膜视网膜病变(CSCR)3mo后脉络膜厚度的变化。方法:前瞻性研究。共纳入60眼,20眼(平均年龄:33.65±5.24岁)典型急性单侧中心性浆液性脉络膜视网膜病变以及对侧正常眼,2... 详细信息

目的:使用光谱域光学相干断层成像(SD-OCT)技术研究中心性浆液性脉络膜视网膜病变(CSCR)3mo后脉络膜厚度的变化。方法:前瞻性研究。共纳入60眼,20眼(平均年龄:33.65±5.24岁)典型急性单侧中心性浆液性脉络膜视网膜病变以及对侧正常眼,20眼为健康对照组。进行荧光素血管造影和OCT检查。测量中心凹下脉络膜厚度(SFCT),黄斑中心凹视网膜厚度(CMT),到中央凹和视网膜下液1000μm处颞部和鼻部。结果:在三个不同的位置,三组间的SFCT差异有统计学意义。中心性浆液性脉络膜视网膜病变眼中心凹下脉络膜厚度(372.40±34.39μm)在基线和随访3mo后均显著大于对侧正常眼(302.10±8.9μm)和对照组眼(279.80±14.49μm)。CSCR眼平均CMT为317±141.86μm,并且SFCT与CMT呈显著正相关。结论:不同部位脉络膜厚度的增加,以及被称为“厚脉络膜”的过度扩张和高渗透血管,似乎在包括中心性浆液性脉络膜视网膜病变在内的广泛疾病中起着重要作用。

关键词：中心性浆液性脉络膜视网膜病变光学相干断层扫描脉络膜厚度厚脉络膜