Search

Background: Chronic kidney disease is a non-communicable global problem. In patients of chronic kidney disease especially in hemodialysis patient mortality and morbidity due to atherosclerosis induced cardiovascular complications is very high despite the advances of hemodialysis procedure. Residual renal function contributes significantly to the overall health and cardiovascular morbidity of dialysis patients. So, the loss of residual renal function, especially in patients on hemodialysis, is a powerful predictor of mortality. Preserving residual renal function is the goal of nephrologists. Objective: To find the association between residual renal function and cardiovascular morbidity in twice weekly and thrice weekly hemodialysis patient. Methodology: This cross sectional study was conducted on 72 hemodialysis patients received dialysis more than three months in the dialysis centre of BSMMU and DMCH, Dhaka, Bangladesh during the period of October 2018 to September 2019. Study populations were divided into two groups on the basis of residual renal function (RRF). RRF was defined by interdialytic 24 hours urine volume and average of urinary urea and creatinine clearance. Preserved RRF was defined 24 hours urine volume more than 100 ml. Chi-square test (χ2), Student’s paired t-test and multiple regression analysis were used to find association between cardiovascular morbidity and RRF. Result: A significant difference of diastolic dysfunction, systolic dysfunction, LVH (p=0.001, p=0.001, p=0.004 respectively) was seen in between preserved RRF and without preserved RRF group but the difference of regional wall motion abnormality and valvular heart disease was found to be non-significant. In regression analysis, loss of RRF was found to be a significant predictor of cardiovascular morbidity. Conclusion: Preserved RRF was significantly associated with less frequent diastolic dysfunction, left ventricular hypertrophy and higher level of left ventricular ejection fraction compared to without preserved residual renal function in both twice weekly and thrice weekly HD patient.

Increasing water pollution is a severe problem in densely industrialized countries. Nanomaterials provide strong potentials for the efficient elimination of organic pollutants due to their beneficial properties. Advancement in water purification is required to more efficiently remove the emerging organic contaminants, especially in pharmaceuticals wastes such as acetophenone, which shows high solubility in industrial wastewaters. Bismuth ferrite-based nanostructures were fabricated using a novel double solvent sol-gel method. The phase purity and crystallinity of bismuth ferrite were confirmed using XRD and further endorsed by TEM analysis. The SEM and XPS were used to study the particle sizes and presence of co-dopants on the Bi and Fe-sites of bismuth ferrite. After co-doping, the band-gap engineering of pure bismuth ferrites was accomplished by reducing it from 2.06 eV to 1.45 eV, likely attributing to the creation of shallow traps for the incoming photo-generated charge carriers. In particular, the Bi0.90Gd0.10Fe0.95Sn0.05 and Bi0.95Sm0.05Fe0.75Mn0.25 successfully eliminated up to 98% of acetophenone from polluted water in 3 h by irradiation of visible-light. These results reveal the suitability of the co-doped bismuth ferrites photocatalysts for the practical removal of pharmaceutical contaminants in hazardous industrial wastewater. The photodegradation of acetophenone by bismuth ferrite nanostructures with potentially long-lasting reusability demonstrate its potential as an advanced photocatalyst for wastewater treatment.

OBJECTIVE: Conduct an overview of systematic reviews (SRs) reviewed by clinical assistants (CAs) in-training. METHOD: SRs relating to clinical procedures and theoretical concepts, critiqued by CAs were included. Review authors independently screened the results of the requested SRs and evaluated these using the AMSTAR-1 checklist and AMSTAR-2 tool. Differences regarding study outcomes were resolved by consultation. RESULTS: Articles (N=37) submitted to the researcher included 35 reviews published in accredited journals. Of the reviews, only 18 were SRs as stated in their titles and these were of mixed designs and quality; and 17 were either non-structured and biased literature or critical reviews. SR topics reviewed in-training varied; and included tem-poro-mandibular disorders, implants and implant-supported prosthesis. AMSTAR-1 scores were favourable; scores were low for most SRs using AMSTAR-2, including those with randomized controlled trials only, with the exception of one review that had no randomized controlled trials but fulfilled the critical domain criteria. CONCLUSION: Students' misconceptions regarding what constitutes good SRs which are translatable into clinical practice are emphasized, impacting their learning. CAs lack of appraisal skills related to SRs which may influence clinical practices are highlighted.

Asiri A, Marwani H, Khan SB, Webster T. Int J Nanomedicine. 2015;10(1):89–96. The authors have advised the note section for Figure 1 on page 90 is incorrect. The correct Notes section is as follows: Notes: SEM images showing the distribution of CNF in the PLGA matrix at 50:50 wt% at (A) random orientation and (B) aligned orientation to mimic the natural anisotropy of cardiac tissue. (C) AFM line scan of the 50:50 CNF:PLGA aligned composite, demonstrating micrometer-scale alignment of the CNFs on the PLGA surface. AFM scans for the randomly oriented CNFs in PLGA matched that of the CNF patterned region. Scale bars =20 µm. Reproduced from Asiri A, Marwani H, Khan SB, Webster T. Greater cardiomyocyte density on aligned compared with random carbon nanofibers in polymer composites. Int J Nanomedicine. 2014;9(1):5533-5539.12 Read the original article

Sher Bahadar Khan,1,2 Khalid A Alamry,2 Nedaa A Alyahyawi,3 Abdullah M Asiri1,2 1Center of Excellence for Advanced Materials Research (CEAMR), King Abdulaziz University, Jeddah, Saudi Arabia; 2Chemistry Department, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia; 3Chemistry Department, Faculty of Science, University of Jeddah, Jeddah, Saudi Arabia Background: The intercalation of an antibiotic drug, cefadroxil (CD), into the inter-gallery of Zn, Al nitrate-layered double hydroxide (LDH) was accomplished using a co-precipitation method. This formed a nanostructured organic–inorganic hybrid material that can be exploited for the preparation of a controlled release formulation. Materials and methods: The drug–LDH nanohybrid was characterized by using field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR) thermogravimetric (TG) analysis, X-ray powder diffraction (XRD) and UV–visible (UV–vis) absorption spectroscopy, which confirmed the intercalation process. Release tests of nanohybrid in the presence or absence of NaCl or polyacrylamide (PAM) were performed in vitro in gastric (pH 1.2), lysosomal (pH 4.0), intestinal (pH 6.8) and blood (pH 7.4) simulated fluid using UV–vis spectroscopy. Results: At pH 1.2, LDH was dissolved and intercalated antibiotic released from ZnAl-CD in a molecular form, which led to a significant increase in the antibiotic’s solubility. Results showed that the release of drug from nanohybrid at pH 4.0, 6.8 and 7.4 was a sustained process. Conclusion: This material might reduce side effects by the release of the drug in a controlled manner. However, it was found that the presence of Cl or PAM species in the release media has a negative impact on the release behavior. The weathering mechanism is responsible for the release of CD from the nanocomposite at pH 1.2, while the mechanism of anion exchange may be responsible for the release behavior at pH 4.0, 6.8 and 7.4. A number of kinetic models were chosen to gain more insights into the mechanisms of drug release. At pH 1.2, the zero-order model most satisfactorily explained the release kinetics of CD, while the release data of CD at pH 4.0, 6.8 and 7.4 were governed by Bhaskar kinetics. Keywords: drug delivery system, ZnAl-CD LDH nanohybrid, hydrotalcite, antibiotic, drug release, kinetics

Abdullah M Asiri,1 Hadi M Marwani,1 Sher Bahadar Khan,1 Thomas J Webster1,2 1Center of Excellence for Advanced Materials Research, King Abdulaziz University, Jeddah, Saudi Arabia; 2Department of Chemical Engineering, Northeastern University, Boston, MA, USA Abstract: Previous studies have demonstrated greater cardiomyocyte density on carbon nanofibers (CNFs) aligned (compared to randomly oriented) in poly(lactic-co-glycolic acid) (PLGA) composites. Although such studies demonstrated a closer mimicking of anisotropic electrical and mechanical properties for such aligned (compared to randomly oriented) CNFs in PLGA composites, the objective of the present in vitro study was to elucidate a deeper mechanistic understanding of how cardiomyocyte densities recognize such materials to respond more favorably. Results showed lower wettability (greater hydrophobicity) of CNFs embedded in PLGA compared to pure PLGA, thus providing evidence of selectively lower wettability in aligned CNF regions. Furthermore, the results correlated these changes in hydrophobicity with increased adsorption of fibronectin, laminin, and vitronectin (all proteins known to increase cardiomyocyte adhesion and functions) on CNFs in PLGA compared to pure PLGA, thus providing evidence of selective initial protein adsorption cues on such CNF regions to promote cardiomyocyte adhesion and growth. Lastly, results of the present in vitro study further confirmed increased cardiomyocyte functions by demonstrating greater expression of important cardiomyocyte biomarkers (such as Troponin-T, Connexin-43, and α-sarcomeric actin) when CNFs were aligned compared to randomly oriented in PLGA. In summary, this study provided evidence that cardiomyocyte functions are improved on CNFs aligned in PLGA compared to randomly oriented in PLGA since CNFs are more hydrophobic than PLGA and attract the adsorption of key proteins (fibronectin, laminin, and vironectin) that are known to promote cardiomyocyte adhesion and expression of important cardiomyocyte functions. Thus, future studies should use this knowledge to further design improved CNF:PLGA composites for numerous cardiovascular applications. Keywords: cardiomyocytes, poly(lactic-co-glycolic acid), carbon nanofibers, aligned, nanotechnology, anisotropy, mechanism, vitronectin, fibronectin, laminin

Abdullah M Asiri,1 Hadi M Marwani,1 Sher Bahadar Khan,1 Thomas J Webster1,2 1Center of Excellence for Advanced Materials Research, King Abdulaziz University, Jeddah, SaudiArabia; 2Department of Chemical Engineering,Northeastern University, Boston, MA, USA Abstract: Carbon nanofibers (CNFs) randomly embedded in poly(lactic-co-glycolic-acid) (PLGA) composites have recently been shown to promote cardiomyocyte growth when compared with conventional PLGA without CNFs. It was shown then that PLGA:CNF composites were conductive and that conductivity increased as greater amounts of CNFs were added to pure PLGA. Moreover, tensile tests showed that addition of CNFs increased the tensile strength of the PLGA composite to mimic that of natural heart tissue. Most importantly, throughout all cytocompatibility experiments, cardiomyocytes were viable and expressed important biomarkers that were greatest on 50:50 wt% CNF:PLGA composites. The increased selective adsorption of fibronectin and vitronectin (critical proteins that mediate cardiomyocyte function) onto such composites proved to be the mechanism of action. However, the natural myocardium is anisotropic in terms of mechanical and electrical properties, which was not emulated in these prior PLGA:CNF composites. Thus, the aim of this in vitro study was to create and characterize CNFs aligned in PLGA composites (at 50:50 wt%, including their mechanical and electrical properties and cardiomyocyte density), comparing such results with randomly oriented CNFs in PLGA. Specifically, CNFs were added to soluble biodegradable PLGA (50:50 PGA:PLA weight ratio) and aligned by applying a voltage and then allowing the polymer to cure. CNF surface micron patterns (20 µm wide) on PLGA were then fabricated through a mold method to further mimic myocardium anisotropy. The results demonstrated anisotropic mechanical and electrical properties and significantly improved cardiomyocyte density for up to 5 days on CNFs aligned in PLGA compared with being randomly oriented in PLGA. These results indicate that CNFs aligned in PLGA should be further explored for improving cardiomyocyte density, which is necessary in numerous cardiovascular applications. Keywords: cardiomyocytes, poly(lactic-co-glycolic acid), carbon nanofibers, aligned, nanotechnology, anisotropy

Summary.-It has been suggested that the procedures of construct validation include at least two distinct processes: one is the validation of the test for measuring a hypothesized construct and the other 1s the validation of the construct, i.e., its usefulness and sigificance as a part of a theoretical system. Factor analysis has been re-evaluated as a method for scudring construct validity of new instruments in face of both theoretical and computarional advances in the field of factor analysis. A numerical index of construct validity has been suggested to be the multiple correlation of the observed variables with the factor (hypothesized construct). The notion of universe of content, the limiting value of the multiple correlation when n + a, etc. have been shown to have important implications for the concept of construct validity. The usefulness of such a procedure for the study of content and predictive validities, item analysis, interpretation of scores and validation of psycho:ogical theories has been outlined. Test validity is often considered and understood in terms of the relationship between the test and a current or remote criterion of an attribute or trait which the cest is designed to predict. A review of the history of the development of psychological tests will indicate that tests have been manufactured with the hope that the finished product will forecast performance on some attribute of interest to the investigator. The emphasis on the prediction of a vaguely defined, contaminated, and imperfect external criterion stems from the idea of the practical usefulness of tests. The important question that haunts the mind of many test developers is not what the cest really measures, but what the test really predicts. Such a criterion-oriented attitude has slowed down the advancement of psychological theory and the development of instruments that can be used in the validation of hypotheses of scientific interest. Travers ( 1951) and Flanagan (1951) have criticized such an approach and have called it the technician's approach to test development.