Browse publications by year: 2019

  1. Aslam MS
    F1000Res, 2019;8:256.
    PMID: 39238530 DOI: 10.12688/f1000research.17893.2
    PURPOSE: Role of genus cassia in the treatment of Constipation Methods: Methodological analysis, systematic review, and meta-analysis of identified studies using RevMan Result and Discussion: Cassia fistula was partially effected in treating constipation however there is a need for improvement in the protocol of studies to reduce biases. These results were only limited to one species so it cannot be generalized among all species of Cassia.

    CONCLUSION: Cassia fistula is partially effective in reducing the pain and consistency of stool during constipation among children.

  2. Beaussant-Cohen S, Jaber F, Massaad MJ, Weeks S, Jones J, Alosaimi MF, et al.
    J Allergy Clin Immunol, 2019 Aug;144(2):606-608.e4.
    PMID: 31103457 DOI: 10.1016/j.jaci.2019.05.003
    This study reports a homozygous mutation in REL abrogating c-Rel protein expression in a patient with combined immunodeficiency characterized by susceptibility to Mycobacterium tuberculosis, Salmonella, Cryptosporidium, and cytomegalovirus.
    MeSH terms: Child; Child, Preschool; Humans; Male; Severe Combined Immunodeficiency/genetics; Severe Combined Immunodeficiency/immunology*; Proto-Oncogene Proteins c-rel/deficiency*; Proto-Oncogene Proteins c-rel/immunology
  3. Jumaah M, Kwong HC, Khairuddean M
    Acta Crystallogr E Crystallogr Commun, 2019 Sep 01;75(Pt 9):1379-1382.
    PMID: 31523470 DOI: 10.1107/S2056989019011289
    The title chalcone derivative, C19H20O5, adopts a trans configuration with respect to the olefinic C=C double bond. The 2-hy-droxy-4-methyl-phenyl ring is coplanar with the attached enone bridge [torsion angle = -179.96 (14)°], where this plane is nearly perpendicular to the 2,4,6-tri-meth-oxy-phenyl ring [dihedral angle = 75.81 (8)°]. In the crystal, mol-ecules are linked into chains propagating along [010] by an O-H⋯O hydrogen bond. These chains are further connected into centrosymmetric dimer chains via weak C-H⋯O inter-actions. The conformations of related chalcone derivatives are surveyed and all of these structures adopt a skeleton with two almost orthogonal aromatic rings.
  4. Pukhovskaya NM, Morozova OV, Vysochina NP, Belozerova NB, Ivanov LI
    Int J Parasitol Parasites Wildl, 2019 Apr;8:192-202.
    PMID: 30891399 DOI: 10.1016/j.ijppaw.2019.01.005
    Borrelia burgdorferi sensu lato (s.l.) DNA was detected by PCR in Ixodes persulcatus Schulze, 1930, Haemaphysalis concinna Koch, 1844, Haemaphysalis japonica douglasi Nuttall et Warburton, 1915 and Dermacentor silvarum Olenev, 1932 ticks collected in the Amur region, the Jewish Autonomous region, the Sakhalin region and on the Khabarovsk territory. Infection rate of I. persulcatus with B. burgdorferi s.l. 10-69% exceeded the corresponding values of three other tick species in all examined regions during 1999-2014 despite different tick abundance and dominance structure. Bacterial loads estimated on the base of quantitative real time PCR varied from 102 to 109 genome-equivalents per a tick with maximal values for I. persulcatus and H. japonica. Phylogenetic analysis of 16S rRNA gene and 5S-23S rRNA intergenic spacer nucleotide sequences revealed two species: 1) Borrelia garinii of Asian type NT29 with several isolates of European type 20047; 2) Borrelia afzelii with identical sequences of the majority of studied isolates and VS461 reference strain in all regions except the Sakhalin Island where B. afzelii was not found. Borrelia miyamotoi of the relapsing fever group was detected as monoinfection or in combination with B. burgdorferi s.l. in 4.0 ± 0.9% and 4.8 ± 0.9% I. persulcatus ticks, respectively. Multiple locus sequence analysis of three fragments of 16S rRNA, glpQ and p66 genes proved that all the Far Eastern B. miyamotoi isolates belonged to the Asian type identical to FR64b strain (GenBank CP004217) from Japan. Wide distribution of Borrelia DNA in ticks, relative genetic homogeneity with similar sequences of the coding regions and the intergenic spacer of Borrelia wild isolates and temporal stability with high homology levels of the Far Eastern isolates of B. garinii, B. afzelii and B. miyamotoi with previously described spirochetes from the surrounding regions of Russia, China and Japan allowed us to suggest multiple ecological niches as the stability factor of the parasitic system.
  5. Heston TF, Pahang JA
    F1000Res, 2019;8:1193.
    PMID: 38435121 DOI: 10.12688/f1000research.19754.4
    Healthcare providers experience moral injury when their internal ethics are violated. The routine and direct exposure to ethical violations makes clinicians vulnerable to harm. The fundamental ethics in health care typically fall into the four broad categories of patient autonomy, beneficence, nonmaleficence, and social justice. Patients have a moral right to determine their own goals of medical care, that is, they have autonomy. When this principle is violated, moral injury occurs. Beneficence is the desire to help people, so when the delivery of proper medical care is obstructed for any reason, moral injury is the result. Nonmaleficence, meaning do no harm, has been a primary principle of medical ethics throughout recorded history. Yet today, even the most advanced and safest medical treatments are associated with unavoidable, harmful side effects. When an inevitable side effect occurs, the patient is harmed, and the clinician is also at risk of moral injury. Social injustice results when patients experience suboptimal treatment due to their race, gender, religion, or other demographic variables. While minor ethical dilemmas and violations routinely occur in medical care and cannot be eliminated, clinicians can decrease the prevalence of a significant moral injury by advocating for the ethical treatment of patients, not only at the bedside but also by addressing the ethics of political influence, governmental mandates, and administrative burdens on the delivery of optimal medical care. Although clinicians can strengthen their resistance to moral injury by deepening their own spiritual foundation, that is not enough. Improvements in the ethics of the entire healthcare system are necessary to improve medical care and decrease moral injury.
    MeSH terms: Bioethics*; Government; Health Facilities; Humans; Morals; Stress Disorders, Post-Traumatic*
  6. Golder V, Kandane-Rathnayake R, Huq M, Louthrenoo W, Luo SF, Wu YJ, et al.
    Lancet Rheumatol, 2019 Oct;1(2):e103-e110.
    PMID: 38229337 DOI: 10.1016/S2665-9913(19)30048-7
    BACKGROUND: Validated outcome measures are needed from which to derive treatment strategies for systemic lupus erythematosus (SLE). However, no definition of remission for SLE has been widely adopted. The Definitions of Remission in Systemic Lupus Erythematosus (DORIS) group has proposed a framework with multiple potential definitions of remission. In this study, we aimed to assess the attainability and effect on disease outcomes of the DORIS definitions of remission, compared with the lupus low disease activity state (LLDAS), in patients with SLE.

    METHODS: In this prospective cohort study, we enrolled patients with SLE from 13 international centres that are part of the Asia Pacific Lupus Collaboration. Eligible patients were older than 18 years and fulfilled one of two classification criteria for SLE (1997 American College of Rheumatology criteria or the 2012 Systemic Lupus International Collaborating Clinics criteria). Visits were according to clinical need, with a minimum frequency of one visit per 6 months. We assessed attainment of remission on the basis of the eight DORIS definitions of remission, which varied in terms of serological activity, glucocorticoid use, and use of immunosuppresive agents; attainment of LLDAS; and disease flares at each visit. Irreversible organ damage accrual was recorded annually. Our primary aim was to assess exposure of patients to each of the remission definitions or LLDAS, and the respective association of these states with accrual of irreversible organ damage as the primary outcome measure. Occurrence of disease flares was the key secondary outcome. We used time-dependent Cox proportional hazards models and generalised linear models to assess DORIS definitions of remission and LLDAS in terms of their association with damage accrual and disease flares.

    FINDINGS: Between May 1, 2013, and Dec 31, 2016, 1707 patients with SLE were recruited and followed for a mean of 2·2 years (SD 0·9), totalling 12 689 visits. Remission, depending on DORIS definition, was achieved in 581 (4·6%) to 4546 (35·8%) of 12 689 visits. Spending 50% or more of observed time in any remission state was associated with a significant reduction in damage accrual, except for the two most stringent remission definitions, for which the frequency of attainment was lowest. Remission definitions disallowing serological activity were associated with the greatest reductions in disease flares. LLDAS was more attainable than any remission definition and was associated with a similar magnitude of protection from damage accrual and disease flares. Sustained remission and LLDAS were associated with a wider spread of effect sizes for reduction in risk of damage. By analysing patients who met the definition for LLDAS but not remission, we found that LLDAS was significantly associated with reduction in damage accrual, independent of all definitions of remission, except the least stringent.

    INTERPRETATION: Attainment of remission was associated with significant reductions in damage accrual and disease flares. LLDAS was more achievable than remission based on the DORIS criteria, but was similarly protective. Remission definitions with less stringency might be insufficiently distinct from LLDAS to substantially affect outcome measures, and further studies are needed to distinguish the protective effects of the various remission definitions.

    FUNDING: UCB, GlaxoSmithKline, Janssen, Bristol-Myers Squibb, and AstraZeneca.

  7. Golder V, Kandane-Rathnayake R, Huq M, Nim HT, Louthrenoo W, Luo SF, et al.
    Lancet Rheumatol, 2019 Oct;1(2):e95-e102.
    PMID: 38229349 DOI: 10.1016/S2665-9913(19)30037-2
    BACKGROUND: Treat-to-target strategies have improved outcomes in single-organ diseases with simple clinical or laboratory endpoints. A lack of validated endpoints has prevented adoption of treat to target for complex multiorgan conditions, such as systemic lupus erythematosus (SLE). We report the first prospective study undertaken to specifically validate a treat-to-target endpoint for SLE.

    METHODS: In this prospective cohort study, patients aged 18 years or older with SLE were recruited from 13 centres in eight countries and followed prospectively. Patients with at least two visits over the study period no more than 6 months apart were included in the longitudinal analysis. Patients with no visits in the final year of the study were censored from their last visit. Attainment of the lupus low disease activity state (LLDAS) was assessed at each visit. The primary outcome measure was accrual of irreversible end-organ damage, defined as at least a 1-point increase in the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index. We used time-dependent hazard regression models and generalised linear models to measure the association between LLDAS (attainment at any timepoint, cumulative time in LLDAS, and sustained LLDAS) with accrual of irreversible end-organ damage or flare (key secondary outcome). This study is registered with ClinicalTrials.gov, NCT03138941.

    FINDINGS: Between May 1, 2013, and Dec 31, 2016, 1707 patients were recruited and followed for a mean of 2·2 years (SD 0·9), totalling 12 689 visits. Attainment of LLDAS at any timepoint was associated with reduction in damage accrual (hazard ratio 0·59, 0·45-0·76; p<0·0001) and subsequent flare (0·65, 95% CI 0·56-0·75; p<0·0001). Cumulative time in LLDAS was associated with improved outcomes: compared with patients with less than 50% of observed time in LLDAS, those with at least 50% of observed time in LLDAS had reduced risk of damage accrual (0·54, 0·42-0·70; p<0·0001) and flare (0·41, 0·35-0·48; p<0·0001). Similarly, increased durations of sustained LLDAS were associated with incremental reductions in the risk of damage accrual. The association of LLDAS with reduced damage accrual was observed regardless of pre-existing damage or disease activity at study entry.

    INTERPRETATION: LLDAS attainment is associated with significant protection against flare and damage accrual in SLE. These findings validate LLDAS as an endpoint for clinical studies in SLE.

    FUNDING: The Asia Pacific Lupus Collaboration received project support grants from UCB Pharma, GlaxoSmithKline, Janssen, Bristol-Myers Squibb, and AstraZeneca.

  8. Saraswati, Giriwono PE, Iskandriati D, Tan CP, Andarwulan N
    Mar Drugs, 2019 Oct 17;17(10).
    PMID: 31627414 DOI: 10.3390/md17100590
    Sargassum is recognized both empirically and scientifically as a potential anti-inflammatory agent. Inflammation is an important response in the body that helps to overcome various challenges to body homeostasis such as microbial infections, tissue stress, and certain injuries. Excessive and uncontrolled inflammatory conditions can affect the pathogenesis of various diseases. This review aims to explore the potential of Sargassum's anti-inflammatory activity, not only in crude extracts but also in sulfated polysaccharides and purified compounds. The tropical region has a promising availability of Sargassum biomass because its climate allows for the optimal growth of seaweed throughout the year. This is important for its commercial utilization as functional ingredients for both food and non-food applications. To the best of our knowledge, studies related to Sargassum's anti-inflammatory activity are still dominated by subtropical species. Studies on tropical Sargassum are mainly focused on the polysaccharides group, though there are some other potentially bioactive compounds such as polyphenols, terpenoids, fucoxanthin, fatty acids and their derivatives, typical polar lipids, and other groups. Information on the modulation mechanism of Sargassum's bioactive compounds on the inflammatory response is also discussed here, but specific mechanisms related to the interaction between bioactive compounds and targets in cells still need to be further studied.
    MeSH terms: Animals; Anti-Inflammatory Agents/pharmacology*; Anti-Inflammatory Agents/chemistry*; Humans; Inflammation/drug therapy; Polysaccharides/pharmacology; Polysaccharides/chemistry; Seaweed/chemistry*; Sargassum/chemistry*; Polyphenols/pharmacology; Polyphenols/chemistry
  9. Puah PY, Herng Lee DJ, Mak KH, Ang HJ, Chen HC, Moh PY, et al.
    RSC Adv, 2019 Oct 07;9(55):31918-31927.
    PMID: 35702663 DOI: 10.1039/c9ra06198c
    The removal of particles using fluoropolymer-based membrane filters is usually done so to prolong the life span of an analytical column, prevent hardware damage, and reduce signal suppression. Ironically, these membrane filters tend to leach impurities into the samples as the samples are filtered through them. These impurities have the potential to affect the researcher's interpretation in high-throughput, non-targeted analysis. In this study, extractable impurities from different brands of fluoropolymer-based membrane filters present in the filtrate filtered using the said filters were investigated. The results demonstrated that different brand membrane filters and materials tend to elute vastly different numbers of impurities. There were instances whereby the extractable impurities persisted in both the membrane filter and the filtrate despite the filter being pre-conditioned (up to 3 times). Principle component analysis revealed that filtrates at different purge intervals are distant from the unfiltered samples. Pre-conditioning of the PTFE membrane filters could potentially reduce the number of extractable impurities across the tested brands. PVDF filtrates, however, tend to co-cluster with their respective brands, thus suggesting that dissimilarity persists in brands following conditioning. As such, pre-conditioning of the PTFE membrane filters should be encouraged so as to reduce false positive results, while the use of PVDF membrane filters for mass-spectrometry-based untargeted analysis is not advisable as extractable impurities would still persist after 3 rounds of conditioning. Neither the use of different filter brands, nor the use of different filter materials in a sample batch are encouraged as different membrane materials or brands could potentially elute varying impurities.
  10. Shtaiwi A, Adnan R, Khairuddean M, Khan SU
    RSC Adv, 2019 Oct 31;9(61):35401-35416.
    PMID: 35541022 DOI: 10.1039/c9ra04759j
    4-Hydroxytamoxifen (4-OHT), the most common hormone used for the treatment of breast cancer, is a selective estrogen receptor modulator (SERM) inhibitor that acts as an antagonist in breast tissue and a partial agonist in the endometrium. However, the detailed molecular mechanism of 4-OHT structure modification has not been well investigated to date. Herein, molecular docking, molecular dynamics simulations and free energy calculations were performed to explore the mechanisms of the molecular interactions between newly designed benzophenone imines (BIs) and the three forms apo, antagonist and agonist of the human estrogen receptor hERα. The proposed inhibitors were designed by replacing the triarylethylene estrogenic scaffold found in 4-OHT with Schiff base triarylimine derivatives. The antiestrogen scaffold i.e. the O-alkyl side chain in 4-OHT was developed by incorporating an alanine amino acid side chain functionality into the triarylimine scaffold. Docking results reveal that the newly designed BIs bind to the hydrophobic open pocket of the apo and antagonist hERα conformations with higher affinity as compared to the natural and synthetic estrogen estradiol (E2) and 4-OHT. The analysis of the molecular dynamics simulation results based on six different systems of the best docked BI (5c) with hERα receptors demonstrates stable interactions, and the complex undergoes fewer conformational fluctuations in the open apo/antagonist hERα receptors as compared to the case of the closed agonist. In addition, the calculated binding free energies indicate that the main factor that contributes to the stabilization of the receptor-inhibitor complexes is hydrophobic interactions. This study suggests that the development of these Schiff base derivatives may be worth exploring for the preparation of new 4-OHT analogues.
  11. Daniyal WMEMM, Fen YW, Anas NAA, Omar NAS, Ramdzan NSM, Nakajima H, et al.
    RSC Adv, 2019 Dec 13;9(71):41729-41736.
    PMID: 35541586 DOI: 10.1039/c9ra07368j
    Surface plasmon resonance (SPR) sensors as novel optical sensors for the detection of a variety of analytes have been receiving increasing attention and their sensitivity has become the research hotspot recently. In this study, the sensitivity of an SPR optical sensor was enhanced by modifying a gold thin film with a nanocrystalline cellulose (NCC)-based material for zinc ion (Zn2+) detection that exists in the environment due to industrial processing. By replacing the gold thin film with a novel modified-gold thin film, Zn2+ can be detected from the range of 0 to 10 ppm using SPR. It is believed that the Zn2+ may interact with the negative charge molecules that exist on the modified-gold thin film, and this was confirmed via X-ray photoelectron spectroscopy (XPS). Moreover, this modified-gold-SPR has a high sensitivity of 1.892° ppm-1 up to 0.1 ppm with an enhanced detection of Zn2+ as low as 0.01 ppm. The SPR results also followed the Langmuir isotherm model with a binding affinity of 1.927 × 103 M-1, which further confirmed the sensitivity of the SPR sensor. In addition, using the modified-gold thin film, SPR has a higher affinity towards Zn2+ compared to other metal ions, i.e. Ni2+, Fe2+, Cr2+, Mn2+, and Co2+.
  12. Ahmed MF, Molla MR, Saha M, Shahriar I, Rahman MS, Halim MA, et al.
    RSC Adv, 2019 Feb 22;9(12):6556-6567.
    PMID: 35518479 DOI: 10.1039/c9ra00070d
    Herein, we have investigated the interaction of bovine serum albumin (BSA), the most abundant globular protein, with a conventional cationic surfactant, cetyldimethylethylammonium bromide (CDMEAB), through a conductivity technique in the absence/presence of electrolyte solutions at various temperatures (298.15-323.15 K). The interaction of the protein with drugs/surfactants and other additives plays a crucial role in the body. Hence, the main concern of the study is to extract the impact of BSA on surfactant molecules and vice versa. From the specific conductivity versus concentration of surfactant plots, three different noticeable critical micelle concentration (c*) values were obtained for pure CDMEAB and its mixture with protein/protein + salts. The presence of BSA and electrolytes altered the c* values of CDMEAB revealing interactions among the studied constituents where the salt solutions reduced the c* values and created a convenient environment for favorable micellization. The negative magnitudes achieved for standard free energy changes (ΔG 0 m) suggest spontaneity of micellization while the values of ΔH 0 m and ΔS 0 m signified the existence of some electrostatic and hydrophobic interactions. The values of molar heat capacity (ΔC 0 m) were positive as well as small which was an indication of less structural deformation. Molecular Dynamics (MD) simulation for all atoms revealed that the salt ions promoted non-covalent interaction between BSA and CDMEAB, and such interactions were not observed in the absence of the salt. Protein structure remained nearly same in spite of strong interaction with CDMEAB as evident from the overall RMSD (root-mean-square deviation) values of the alpha carbons and backbone of the protein and RMSF (root-mean-square fluctuation) values of the amino acid residues present in BSA. In this work thermodynamic parameters of transfer (such as ΔG 0 m.tr., ΔH 0 m.tr., and ΔC 0 p.m.tr.) were also evaluated and the results are discussed in detail. Besides, contributions of enthalpy and entropy to free energy changes were also analyzed.
  13. Pal B, Yang S, Ramesh S, Thangadurai V, Jose R
    Nanoscale Adv, 2019 Oct 09;1(10):3807-3835.
    PMID: 36132093 DOI: 10.1039/c9na00374f
    Electrolytes are one of the vital constituents of electrochemical energy storage devices and their physical and chemical properties play an important role in these devices' performance, including capacity, power density, rate performance, cyclability and safety. This article reviews the current state of understanding of the electrode-electrolyte interaction in supercapacitors and battery-supercapacitor hybrid devices. The article discusses factors that affect the overall performance of the devices such as the ionic conductivity, mobility, diffusion coefficient, radius of bare and hydrated spheres, ion solvation, viscosity, dielectric constant, electrochemical stability, thermal stability and dispersion interaction. The requirements needed to design better electrolytes and the challenges that still need to be addressed for building better supercapacitive devices for the competitive energy storage market have also been highlighted.
  14. Tan A, Babak MV, Venkatesan G, Lim C, Klotz KN, Herr DR, et al.
    Molecules, 2019 Oct 11;24(20).
    PMID: 31614517 DOI: 10.3390/molecules24203661
    Human A3 adenosine receptor hA3AR has been implicated in gastrointestinal cancer, where its cellular expression has been found increased, thus suggesting its potential as a molecular target for novel anticancer compounds. Observation made in our previous work indicated the importance of the carbonyl group of amide in the indolylpyrimidylpiperazine (IPP) for its human A2A adenosine receptor (hA2AAR) subtype binding selectivity over the other AR subtypes. Taking this observation into account, we structurally modified an indolylpyrimidylpiperazine (IPP) scaffold, 1 (a non-selective adenosine receptors' ligand) into a modified IPP (mIPP) scaffold by switching the position of the carbonyl group, resulting in the formation of both ketone and tertiary amine groups in the new scaffold. Results showed that such modification diminished the A2A activity and instead conferred hA3AR agonistic activity. Among the new mIPP derivatives (3-6), compound 4 showed potential as a hA3AR partial agonist, with an Emax of 30% and EC50 of 2.89 ± 0.55 μM. In the cytotoxicity assays, compound 4 also exhibited higher cytotoxicity against both colorectal and liver cancer cells as compared to normal cells. Overall, this new series of compounds provide a promising starting point for further development of potent and selective hA3AR partial agonists for the treatment of gastrointestinal cancers.
    MeSH terms: Animals; Cricetulus; Gastrointestinal Neoplasms/drug therapy*; Gastrointestinal Neoplasms/genetics; Gastrointestinal Neoplasms/pathology; Cricetinae; Humans; Indoles/chemical synthesis; Indoles/pharmacology; Indoles/chemistry; Models, Molecular; Pyrimidinones/chemical synthesis; Pyrimidinones/pharmacology; Pyrimidinones/chemistry*; Structure-Activity Relationship; CHO Cells; Receptor, Adenosine A3/genetics*; Receptor, Adenosine A2A/genetics*; Receptor, Adenosine A2A/chemistry; Cell Proliferation/drug effects; Adenosine A2 Receptor Antagonists/chemical synthesis; Adenosine A2 Receptor Antagonists/pharmacology; Adenosine A2 Receptor Antagonists/chemistry
  15. Abdullah Issa M, Z Abidin Z, Sobri S, Rashid S, Adzir Mahdi M, Azowa Ibrahim N, et al.
    Nanomaterials (Basel), 2019 Oct 22;9(10).
    PMID: 31652527 DOI: 10.3390/nano9101500
    The current research mainly focuses on transforming low-quality waste into value-added nanomaterials and investigating various ways of utilising them. The hydrothermal preparation of highly fluorescent N-doped carbon dots (N-CDs) was obtained from the carboxymethylcellulose (CMC) of oil palm empty fruit bunches and linear-structured polyethyleneimines (LPEI). Transmission electron microscopy (TEM) analysis showed that the obtained N-CDs had an average size of 3.4 nm. The N-CDs were monodispersed in aqueous solution and were strongly fluorescent under the irradiation of ultra-violet light. A detailed description of the morphology and shape was established using Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). It was shown that LPEI were successfully tuned the fluorescence (PL) properties of CDs in both the intrinsic and surface electronic structures, and enhanced the quantum yield (QY) up to 44%. The obtained N-CDs exhibited remarkable PL stability, long lifetime and pH-dependence behaviour, with the excitation/emission maxima of 350/465.5 nm. Impressively, PL enhancement and blue-shifted emission could be seen with the dilution of the original N-CDs solution. The obtained N-CDs were further applied as fluorescent probe for the identification of Cu2+ in aqueous media. The mechanism could be attributed to the particularly high thermodynamic affinity of Cu2+ for the N-chelate groups over the surface of N-CDs and the fast metal-to-ligand binding kinetics. The linear relationship between the relative quenching rate and the concentration of Cu2+ were applied between 1-30 µM, with a detection limit of 0.93 µM. The fluorescent probe was successfully applied for the detection of Cu2+ in real water. Moreover, a solid-state film of N-CDs was prepared in the presence of poly (vinyl alcohol) (PVA) polymer and found to be stable even after 72-h of continuous irradiation to UV-lamp. In contrast to the aqueous N-CDs, the composite film showed only an excitation independent property, with enhanced PL QY of around 47%. Due to the strong and stable emission nature of N-CDs in both aqueous and solid conditions, the obtained N-CDs are ideal for reducing the overall preparation costs and applying them for various biological and environmental applications in the future.
  16. Panda B, Noor Mohamed NA, Paul SC, Bhagath Singh G, Tan MJ, Šavija B
    Materials (Basel), 2019 Jul 04;12(13).
    PMID: 31277393 DOI: 10.3390/ma12132149
    The advent of digital concrete fabrication calls for advancing our understanding of the interaction of 3D printing with material rheology and print parameters, in addition to developing new measurement and control techniques. Thixotropy is the main challenge associated with printable material, which offers high yield strength and low viscosity. The higher the thixotropy, the better the shape stability and the higher buildability. However, exceeding a minimum value of thixotropy can cause high extrusion pressure and poor interface bond strength if the printing parameters are not optimized to the part design. This paper aims to investigate the effects of both material and process parameters on the buildability and inter-layer adhesion properties of 3D printed cementitious materials, produced with different thixotropy and print head standoff distances. Nano particles are used to increase the thixotropy and, in this context, a lower standoff distance is found to be useful for improving the bond strength. The low viscosity "control" sample is unaffected by the variation in standoff distances, which is attributed to its flowability and low yield stress characteristics that lead to strong interfacial bonding. This is supported by our microscopic observations.
  17. Ramly B, Afiqah-Aleng N, Mohamed-Hussein ZA
    Int J Mol Sci, 2019 Jun 18;20(12).
    PMID: 31216618 DOI: 10.3390/ijms20122959
    Based on clinical observations, women with polycystic ovarian syndrome (PCOS) are prone to developing several other diseases, such as metabolic and cardiovascular diseases. However, the molecular association between PCOS and these diseases remains poorly understood. Recent studies showed that the information from protein-protein interaction (PPI) network analysis are useful in understanding the disease association in detail. This study utilized this approach to deepen the knowledge on the association between PCOS and other diseases. A PPI network for PCOS was constructed using PCOS-related proteins (PCOSrp) obtained from PCOSBase. MCODE was used to identify highly connected regions in the PCOS network, known as subnetworks. These subnetworks represent protein families, where their molecular information is used to explain the association between PCOS and other diseases. Fisher's exact test and comorbidity data were used to identify PCOS-disease subnetworks. Pathway enrichment analysis was performed on the PCOS-disease subnetworks to identify significant pathways that are highly involved in the PCOS-disease associations. Migraine, schizophrenia, depressive disorder, obesity, and hypertension, along with twelve other diseases, were identified to be highly associated with PCOS. The identification of significant pathways, such as ribosome biogenesis, antigen processing and presentation, and mitophagy, suggest their involvement in the association between PCOS and migraine, schizophrenia, and hypertension.
    MeSH terms: Disease Susceptibility*; Female; Humans; Polycystic Ovary Syndrome/etiology; Polycystic Ovary Syndrome/metabolism*; Signal Transduction; Biomarkers; Computational Biology/methods; Protein Interaction Mapping*; Protein Interaction Maps*
  18. Kamuri MF, Zainal Abidin Z, Yaacob MH, Hamidon MN, Md Yunus NA, Kamarudin S
    Biosensors (Basel), 2019 Mar 14;9(1).
    PMID: 30875829 DOI: 10.3390/bios9010040
    This paper describes the development of an integrated system using a dry film resistant (DFR) microfluidic channel consisting of pulsed field dielectrophoretic field-flow-fractionation (DEP-FFF) separation and optical detection. The prototype chip employs the pulse DEP-FFF concept to separate the cells (Escherichia coli and Saccharomyces cerevisiae) from a continuous flow, and the rate of release of the cells was measured. The separation experiments were conducted by changing the pulsing time over a pulsing time range of 2⁻24 s and a flow rate range of 1.2⁻9.6 μ L min - 1 . The frequency and voltage were set to a constant value of 1 M Hz and 14 V pk-pk, respectively. After cell sorting, the particles pass the optical fibre, and the incident light is scattered (or absorbed), thus, reducing the intensity of the transmitted light. The change in light level is measured by a spectrophotometer and recorded as an absorbance spectrum. The results revealed that, generally, the flow rate and pulsing time influenced the separation of E. coli and S. cerevisiae. It was found that E. coli had the highest rate of release, followed by S. cerevisiae. In this investigation, the developed integrated chip-in-a lab has enabled two microorganisms of different cell dielectric properties and particle size to be separated and subsequently detected using unique optical properties. Optimum separation between these two microorganisms could be obtained using a longer pulsing time of 12 s and a faster flow rate of 9.6 μ L min - 1 at a constant frequency, voltage, and a low conductivity.
    MeSH terms: Cell Separation/instrumentation; Cell Separation/methods*; Escherichia coli/cytology*; Fiber Optic Technology/instrumentation; Fiber Optic Technology/methods*; Saccharomyces cerevisiae/cytology*; Microfluidics/instrumentation; Microfluidics/methods*
  19. Subramaniam MN, Goh PS, Lau WJ, Ismail AF
    Nanomaterials (Basel), 2019 Apr 17;9(4).
    PMID: 30999639 DOI: 10.3390/nano9040625
    Heavy metal (HM) pollution in waterways is a serious threat towards global water security, as high dosages of HM poisoning can significantly harm all living organisms. Researchers have developed promising methods to isolate, separate, or reduce these HMs from water bodies to overcome this. This includes techniques, such as adsorption, photocatalysis, and membrane removal. Nanomaterials play an integral role in all of these remediation techniques. Nanomaterials of different shapes have been atomically designed via various synthesis techniques, such as hydrothermal, wet chemical synthesis, and so on to develop unique nanomaterials with exceptional properties, including high surface area and porosity, modified surface charge, increment in active sites, enhanced photocatalytic efficiency, and improved HM removal selectivity. In this work, a comprehensive review on the role that nanomaterials play in removing HM from waterways. The unique characteristics of the nanomaterials, synthesis technique, and removal principles are presented. A detailed visualisation of HM removal performances and the mechanisms behind this improvement is also detailed. Finally, the future directions for the development of nanomaterials are highlighted.
  20. Alowayesh MS, Ahmed SF, Al-Hashel J, Alroughani R
    PLoS One, 2019;14(5):e0216646.
    PMID: 31086393 DOI: 10.1371/journal.pone.0216646
    BACKGROUND: Multiple Sclerosis (MS) is a chronic neurological disease with heavy economic and social burdens resulting in significant disability.

    OBJECTIVE: This study aims to (1) measure the cost of health resources utilization by MS patients and (2) to examine the difference in utilization and its attributed costs amongst patients who may have a different course of MS and expanded disability status scale (EDSS) scores.

    METHODS: A cross-sectional study using Kuwait National MS registry was conducted to estimate the costs of utilization of resources from 2011 to 2015.

    RESULTS: Between the period 2011-2015, 1344 MS patients were included in the registry. The average annual cost per MS patient has increased from $10,271 in 2011 to $17,296 in 2015. Utilization of disease-modifying therapies (DMTs) was the main driver of costs reaching 89.9% in 2015. Throughout the five-year period, the occurrence of relapses decreased from 21.8% to 12.2% (p <0.0001). During this same period, ambulatory relapse treatment increased by 5.8% while hospitalizations decreased by 2.6%. Patients with a moderate EDSS score (3.5-6) had the highest average cost (p<0.0001) compared to mild and severe EDSS scores.

    CONCLUSIONS: Multiple sclerosis has been a significant economic burden on the Kuwait healthcare system. DMTs are the main driver of cost.

    MeSH terms: Adult; Delivery of Health Care/economics*; Female; Disabled Persons/statistics & numerical data; Humans; Kuwait/epidemiology; Male; Multiple Sclerosis/economics*; Multiple Sclerosis/epidemiology; Cost of Illness*; Age of Onset
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