Publications by authors named "A Najib"

64 Publications

Comparative molecular dynamics simulations of thermal conductivities of aqueous and hydrocarbon nanofluids.

Beilstein J Nanotechnol 2022 7;13:620-628. Epub 2022 Jul 7.

Changzhou University, School of Materials Science and Engineering, Changzhou Science Town, Changzhou, P. R. China.

The addition of metal oxide nanoparticles to fluids has been used as a means of enhancing the thermal conductive properties of base fluids. This method formulates a heterogeneous fluid conferred by nanoparticles and can be used for high-end fluid heat-transfer applications, such as phase-change materials and fluids for internal combustion engines. These nanoparticles can enhance the properties of both polar and nonpolar fluids. In the current paper, dispersions of nanoparticles were carried out in hydrocarbon and aqueous-based fluids using molecular dynamic simulations (MDS). The MDS results have been validated using the autocorrelation function and previous experimental data. Highly concurrent trends were achieved for the obtained results. According to the obtained results of MDS, adding CuO nanoparticles increased the thermal conductivity of water by 25% (from 0.6 to 0.75 W·m·K). However, by adding these nanoparticles to hydrocarbon-based fluids (i.e., alkane) the thermal conductivity was increased three times (from 0.1 to 0.4 W·m·K). This approach to determine the thermal conductivity of metal oxide nanoparticles in aqueous and nonaqueous fluids using visual molecular dynamics and interactive autocorrelations demonstrate a great tool to quantify thermophysical properties of nanofluids using a simulation environment. Moreover, this comparison introduces data on aqueous and nonaqueous suspensions in one study.
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http://dx.doi.org/10.3762/bjnano.13.54DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9273982PMC
July 2022

Terrible triad injury of the elbow: A PROCESS-compliant surgical case series from Eastern Morocco.

Ann Med Surg (Lond) 2022 Jun 4;78:103914. Epub 2022 Jun 4.

Department of Traumatology and Orthopedics, Mohammed VI University Hospital, Oujda, Morocco.

Introduction: The terrible triad of the elbow (TTE) is a lesion associating a dislocation of the elbow, a fracture of the radial head, and a fracture of the coronoid process, with a high potential of complication. The treatment is based on the restoration of bone lesions and external capsular ligament repair. The systematic repair of the medial collateral ligament (MCL) is still debated in the literature. The aim of this study is to evaluate the clinical and functional results of the surgical treatment in a real-world series from Easter Morocco.

Patients And Methods: This was a retrospective study of 6 cases of TTE operated by isolated external approach or combined approach (internal or anterior) of the elbow in the department of Traumatology-Orthopedics of the Mohammed VI University Hospital (Oujda Morocco), over a period of 7 years from 2013 to 2020. Radial head and coronoid process fractures were classified according to the Mason and Morrey-Regan classifications, respectively. The following clinical parameters were evaluated: Mayo Clinic Elbow Performance Score (MEPS), Quick Disabilities of the Arm, Shoulder and Hand (DASH), Visual Analog Scale (VAS), and arc of mobility in flexion-extension and prono-supination.

Results: 6 male patients treated between May 2013 and December 2020 were included. The median follow-up was 48 months. All patients had frontal and lateral standard X-ray of over and under joints, and computed tomography (CT)-scan was delivered for 5 cases. The elbow dislocation was posterolateral in five cases, and posteromedial in only one patient. Radial head fractures were classified as type I in one case, type II in two cases, and type III in three cases. Coronoid fractures were type I in three cases, type II in one case, and type III in two cases. At the last follow up, the mean MEPS, Quick DASH, and VAS was 81, 28, 0.8, respectively. The mean arc of mobility in flexion was 120° and it was deficient by 20° in extension. In addition, the mean arc of mobility in protonation was 80°, while in supination it was 75°. Regarding complications, we noticed an instability of the elbow on valgus in a single case, elbow stiffness with heterotopic ossification in a single case, ulnar nerve damage in a single case during medial collateral ligament anchoring, and elbow hygroma in one single case.

Conclusion: The surgical management of TTE can provide good and long-term functional results after restoration of the stabilization of bone structures and the lateral ligament complex, without the need to repair the medial collateral ligament.
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http://dx.doi.org/10.1016/j.amsu.2022.103914DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9207080PMC
June 2022

Performance Comparison of Cross- and Forward-Flow Configurations for Multiple-Effect Vacuum Membrane Distillation.

Membranes (Basel) 2022 Apr 30;12(5). Epub 2022 Apr 30.

Department of Applied Mechanical Engineering, College of Applied Engineering, Muzahimiyah Branch, King Saud University, P.O. Box 800, Riyadh 11421, Saudi Arabia.

This work addresses retrofitting the infrastructure of multiple-effect vacuum membrane distillation (V-MEMD) units by using cross-flow configuration (CFC). In this configuration, the feed water is evenly divided and distributed over the effects. In this case, the feed water stream for each effect is kept at a high temperature and low flow rate. This will lead to an increase in the vapor pressure gradient across the hydrophobic membrane and can also maintain the thermal energy of the stream inside the individual effect. It is found that CFC improves internal and global performance indicators of productivity, energy, and exergy. A mathematical model was used to investigate the performance of such a modification as compared to the forward-flow configuration (FFC). The cross-flow configuration led to a clear improvement in the internal performance indicators of the V-MEMD unit, where specifically the mass flux, recovery ratio, gain output ratio, and heat recovery factor were increased by 2 to 3 folds. Moreover, all the global performance indicators were also enhanced by almost 2 folds, except for the performance indicators related to the heat pump, which is used to cool the cold water during the operation of the V-MEMD unit. For the heat pump system, the specific electrical energy consumption, SEEC, and the exergy destruction percentage, , under the best-operating conditions, were inferior when the feed water flow was less than 159 L/h. This can be attributed to the fact that the heat rejected from the heat pump system is not fully harnessed.
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http://dx.doi.org/10.3390/membranes12050495DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9147542PMC
April 2022

Identification of Stingless Bee Honey Adulteration Using Visible-Near Infrared Spectroscopy Combined with Aquaphotomics.

Molecules 2022 Apr 3;27(7). Epub 2022 Apr 3.

School of Physics, Universiti Sains Malaysia, Pulau Pinang 11800, Malaysia.

Honey is a natural product that is considered globally one of the most widely important foods. Various studies on authenticity detection of honey have been fulfilled using visible and near-infrared (Vis-NIR) spectroscopy techniques. However, there are limited studies on stingless bee honey (SBH) despite the increase of market demand for this food product. The objective of this work was to present the potential of Vis-NIR absorbance spectroscopy for profiling, classifying, and quantifying the adulterated SBH. The SBH sample was mixed with various percentages (10-90%) of adulterants, including distilled water, apple cider vinegar, and high fructose syrup. The results showed that the region at 400-1100 nm that is related to the color and water properties of the samples was effective to discriminate and quantify the adulterated SBH. By applying the principal component analysis (PCA) on adulterants and honey samples, the PCA score plot revealed the classification of the adulterants and adulterated SBHs. A partial least squares regression (PLSR) model was developed to quantify the contamination level in the SBH samples. The general PLSR model with the highest coefficient of determination and lowest root means square error of cross-validation (RCV2=0.96 and RMSECV=5.88 %) was acquired. The aquaphotomics analysis of adulteration in SBH with the three adulterants utilizing the short-wavelength NIR region (800-1100 nm) was presented. The structural changes of SBH due to adulteration were described in terms of the changes in the water molecular matrix, and the aquagrams were used to visualize the results. It was revealed that the integration of NIR spectroscopy with aquaphotomics could be used to detect the water molecular structures in the adulterated SBH.
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http://dx.doi.org/10.3390/molecules27072324DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9000493PMC
April 2022

Prognostic Value of Venous Thromboembolism Risk Assessment Models in Patients with Severe COVID-19.

TH Open 2021 Apr 22;5(2):e211-e219. Epub 2021 Jun 22.

Cardiovascular Division, Department of Medicine, NorthShore University Health System, Evanston, Illinois, United States.

 Severe novel corona virus disease 2019 (COVID-19) causes dysregulation of the coagulation system with arterial and venous thromboembolism (VTE). We hypothesize that validated VTE risk scores would have prognostic ability in this population.  Retrospective observational cohort with severe COVID-19 performed in NorthShore University Health System. Patients were >18 years of age and met criteria for inpatient or intensive care unit (ICU) care. The International Medical Prevention Registry on Venous Thromboembolism (IMPROVE) and Caprini scores were calculated and patients were stratified.  This study includes 184 patients, mostly men (63.6%), Caucasian (54.3%), 63 years old (interquartile range [IQR]: 24-101), and 57.1% of them required ICU care. Twenty-seven (14.7%) thrombotic events occurred: 12 (6.5%) cases of disseminated intravascular coagulation (DIC), 9 (4.9%) of pulmonary embolism, 5 (2.7%) of deep vein thrombosis, and 1 (0.5%) stroke. Among them, 86 patients (46.7%) died, 95 (51.6%) were discharged, and 3 (1.6%) were still hospitalized. "Moderate risk for VTE" and "High risk for VTE" by IMPROVE score had significant mortality association: (hazard ratio [HR]: 5.68; 95% confidence interval [CI]: 2.93-11.03;  < 0.001) and (HR = 6.22; 95% CI: 3.04-12.71;  < 0.001), respectively, with 87% sensitivity and 63% specificity (area under the curve [AUC] = 0.752,  < 0.001). "High Risk for VTE" by Caprini score had significant mortality association (HR = 17.6; 95% CI: 5.56-55.96;  < 0.001) with 96% sensitivity and 55% specificity (AUC = 0.843,  < 0.001). Both scores were associated with thrombotic events when classified as "High risk for VTE" by IMPROVE (HR = 6.50; 95% CI: 2.72-15.53;  < 0.001) and Caprini scores (HR = 11.507; 95% CI: 2.697-49.104;  = 0.001).  The IMPROVE and Caprini risk scores were independent predictors of mortality and thrombotic events in severe COVID-19. With larger validation, this can be useful prognostic information.
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http://dx.doi.org/10.1055/s-0041-1730293DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8219405PMC
April 2021
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