Displaying publications 1 - 20 of 75 in total

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  1. Arshat H, Ali J, Noor Laily Abu Bakar
    Malays J Reprod Health, 1984 Jun;2(1):1-13.
    PMID: 12267515
  2. Alsabery AI, Tayebi T, Chamkha AJ, Hashim I
    Sci Rep, 2020 Oct 22;10(1):18048.
    PMID: 33093608 DOI: 10.1038/s41598-020-75095-5
    This study investigates thermal natural convective heat transfer in a nanofluid filled-non-Darcian porous and wavy-walled domain under the local thermal non-equilibrium condition. The considered cavity has corrugated and cold vertical walls and insulated horizontal walls except the heated part positioned at the bottom wall. The transport equations in their non-dimensional model are numerically solved based on the Galerkin finite-element discretization technique. The dimensionless governing parameters of the present work are the nanoparticle in volume concentration, the Darcy number, number of undulations, modified heat conductivity ratio, dimensionless heated part length, and location. Comparisons with other published theoretical and experimental results show good agreement with the present outcomes. The findings indicate that the heater length, its position, and the waves number on the side vertical walls as well as the nanoparticles concentration can be the control parameters for free convective motion and heat transport within the wavy cavity.
  3. Alsabery AI, Ishak MS, Chamkha AJ, Hashim I
    Entropy (Basel), 2018 May 03;20(5).
    PMID: 33265426 DOI: 10.3390/e20050336
    The problem of entropy generation analysis and natural convection in a nanofluid square cavity with a concentric solid insert and different temperature distributions is studied numerically by the finite difference method. An isothermal heater is placed on the bottom wall while isothermal cold sources are distributed along the top and side walls of the square cavity. The remainder of these walls are kept adiabatic. Water-based nanofluids with Al 2 O 3 nanoparticles are chosen for the investigation. The governing dimensionless parameters of this study are the nanoparticles volume fraction ( 0 ≤ ϕ ≤ 0.09 ), Rayleigh number ( 10 3 ≤ R a ≤ 10 6 ) , thermal conductivity ratio ( 0.44 ≤ K r ≤ 23.8 ) and length of the inner solid ( 0 ≤ D ≤ 0.7 ). Comparisons with previously experimental and numerical published works verify a very good agreement with the proposed numerical method. Numerical results are presented graphically in the form of streamlines, isotherms and local entropy generation as well as the local and average Nusselt numbers. The obtained results indicate that the thermal conductivity ratio and the inner solid size are excellent control parameters for an optimization of heat transfer and Bejan number within the fully heated and partially cooled square cavity.
  4. Ishak MS, Alsabery AI, Hashim I, Chamkha AJ
    Sci Rep, 2021 Jul 19;11(1):14700.
    PMID: 34282226 DOI: 10.1038/s41598-021-94238-w
    The entropy production and mixed convection within a trapezoidal nanofluid-filled cavity having a localised solid cylinder is numerically examined using the finite element technique. The top horizontal surface moving at a uniform velocity is kept at a cold temperature, while the bottom horizontal surface is thermally activated. The remaining surfaces are maintained adiabatic. Water-based nanofluids ([Formula: see text] nanoparticles) are used in this study, and the Boussinesq approximation applies. The influence of the Reynolds number, Richardson number, nanoparticles volume fraction, dimensionless radius and location of the solid cylinder on the streamlines, isotherms and isentropic are examined. The results show that the solid cylinder's size and location are significant control parameters for optimising the heat transfer and the Bejan number inside the trapezoidal cavity. Furthermore, the maximum average Nusselt numbers are obtained for high R values, where the average Nusselt number is increased by 30% when R is raised from 0 to 0.25.
  5. Alsabery AI, Ismael MA, Chamkha AJ, Hashim I
    Entropy (Basel), 2018 Sep 03;20(9).
    PMID: 33265753 DOI: 10.3390/e20090664
    This numerical study considers the mixed convection and the inherent entropy generated in Al 2 O 3 -water nanofluid filling a cavity containing a rotating conductive cylinder. The vertical walls of the cavity are wavy and are cooled isothermally. The horizontal walls are thermally insulated, except for a heat source segment located at the bottom wall. The dimensionless governing equations subject to the selected boundary conditions are solved numerically using the Galerkin finite-element method. The study is accomplished by inspecting different ranges of the physical and geometrical parameters, namely, the Rayleigh number ( 10 3 ≤ R a ≤ 10 6 ), angular rotational velocity ( 0 ≤ Ω ≤ 750 ), number of undulations ( 0 ≤ N ≤ 4 ), volume fraction of Al 2 O 3 nanoparticles ( 0 ≤ ϕ ≤ 0.04 ), and the length of the heat source ( 0.2 ≤ H ≤ 0.8 ) . The results show that the rotation of the cylinder boosts the rate of heat exchange when the Rayleigh number is less than 5 × 10 5 . The number of undulations affects the average Nusselt number for a still cylinder. The rate of heat exchange increases with the volume fraction of the Al 2 O 3 nanoparticles and the length of the heater segment.
  6. Ali J, Cheah FKC
    Med J Malaysia, 1987 Sep;42(3):201-3.
    PMID: 3333537
    A rare complication of per rectal extrusion of a ventricule peritoneal shunt catheter occuring in a four-month old Chinese baby boy with hydrocephalus is described. Perforation of the bowel by the shunt occurred without any peritonitis or retrograde infection of the shunt system. Its pathogenesis and diagnosis are discussed.
  7. Bahadoran M, Ali J, Yupapin PP
    Appl Opt, 2013 Apr 20;52(12):2866-73.
    PMID: 23669699 DOI: 10.1364/AO.52.002866
    In this paper, the bifurcation behavior of light in the PANDA ring resonator is investigated using the signal flow graph (SFG) method, where the optical transfer function for the through and drop ports of the PANDA Vernier system are derived. The optical nonlinear phenomena, such as bistability, Ikeda instability, and dynamics of light in the silicon-on-insulator (SOI) PANDA ring resonator with four couplers are studied. The transmission curves for bistability and instability as a function of the resonant mode numbers and coupling coefficients for the coupler are derived by the SFG method and simulated. The proposed system has an advantage as no optical pumping component is required. Simulated results show that closed-loop bistable switching can be generated and achieved by varying mode resonant numbers in the SOI-PANDA Vernier resonator, where a smooth and closed-loop bistable switching with low relative output/input power can be obtained and realized. The minimum through-port switching time of 1.1 ps for resonant mode numbers of 5;4;4 and minimum drop port switching time of 1.96 ps for resonant mode numbers of 9;7;7 of the PANDA Vernier resonator are achieved, which makes the PANDA Vernier resonator an operative component for optical applications, such as optical signal processing and a fast switching key in photonics integrated circuits.
  8. Ali J, Hassan K, Arshat H
    Med J Malaysia, 1981 Dec;36(4):215-9.
    PMID: 7334956
    The present findings suggest the possible involvement of an active mechanism for transport of iron to the fetus. In all the 19 subjects studied, the cord serum iron levels tended to be higher (129.2 ± 56.8 ug/100ml) than the maternal serum iron levels (74.0 ± 35.9 ug/100ml) at parturition even in maternal iron deficiency. The significant difference (P< 0.001) between cord serum iron levels and the maternal iron levels shows that an active transport mechanism working against a gradient in favour of the fetus exists. The availability of iron to the fetus appears to be dependent on maternal serum iron levels but not on maternal iron stores. This finding serves to stress the importance of iron supplements in pregnancy. A hypothetical model for iron transfer from maternal circulation to fetal circulation is described.
  9. Sakijan AS, Zambahari R, Annuar Z, Yahya O, Ali J
    Med J Malaysia, 1990 Dec;45(4):340-3.
    PMID: 2152057
    A successful retrieval of a detached segment of a CVP catheter by percutaneous right transfemoral venous route, using a Dotter intravascular retriever basket, is reported. The procedure was monitored under fluoroscopy. Only local anaesthesia, which was infiltrated around the puncture site, was given to the patient. No significant complication was encountered. Successful retrieval of the detached catheter fragment by percutaneous means obviates the need for thoracotomy.
  10. Ali J, Hassan K, Arshat H
    Med J Malaysia, 1982 Jun;37(2):160-4.
    PMID: 6890140
    Folate and vitamin B 12 status in pregnancy was studied in a group of 190 Malaysian mothers belonging to the three major ethnic origins. Cord blood was also analysed for the same vitamins. Ethnic variations with regard to deficiency in these two vitamins was determined. About 58.5 percent of the pregnant mothers suffered from lowered serum folate levels and 32.4 percent had lowered RBC folate levels. In contrast vitamin B 12 levels were within normal limits. Cord blood levels of these vitamins were significantly higher than. the corresponding levels in the maternal blood, suggesting the possible involvement of an active process in the transfer of folates and vitamin B 12 to the fetus.
  11. Dabagh S, Chaudhary K, Haider Z, Ali J
    J Nanosci Nanotechnol, 2019 Jul 01;19(7):4142-4146.
    PMID: 30764983 DOI: 10.1166/jnn.2019.16331
    Aluminium substituted cobalt-copper Co1-xCuxFe2-xAlxO₄, (x ═ 0.8) nanoparticles are grown and sintered at different temperature in the range 600 to 900 °C. XRD analysis on nanoparticles prepared at sintered temperatures of 700 °C and 800 °C confirms the spinel structure and presence of hematite phase (alpha ferrite) in them. The dielectric behaviour of the prepared nano-particles is investigated. Although crystallinity improved with increase in sintering temperature and there was a dielectric loss at higher probe analyser frequency. The synthesized nanoparticles an average particle size of 20-24 nm while the FTIR absorption in regions of 586-595 cm-1 and 450-460 cm-1 indicated the presence of intrinsic vibrations of the tetrahedral and octahedral complexes respectively. Electrical resistivity as a function of temperature confirms the semiconducting nature of the Cu-Al substituted cobalt ferrite, and is attributed to the hopping mechanism between Fe2+ Fe3+ ions and Co2+ Cu2+, Co2+ Al3+. The lower values of dielectric constants and dielectric losses make Al-Cu doped cobalt ferrite, a potential material for microwave and radio wave absorber applications.
  12. Ali J, AlHarbi NH, Ali N
    Methods Mol Biol, 2017;1568:3-20.
    PMID: 28421485 DOI: 10.1007/978-1-4939-6828-2_1
    This chapter describes the development of the science of cryopreservation of gametes and embryos of various species including human. It attempts to record in brief the main contributions of workers in their attempts to cryopreserve gametes and embryos. The initial difficulties faced and subsequent developments and triumphs leading to present-day state of the art are given in a concise manner. The main players and their contributions are mentioned and the authors' aim is to do justice to them. This work also attempts to ensure that credit is correctly attributed for significant advances in gamete and embryo cryopreservation. In general this chapter has tried to describe the historical development of the science of cryopreservation of gametes and embryos as accurately as possible without bias or partiality.
  13. Md S, Mustafa G, Baboota S, Ali J
    Drug Dev Ind Pharm, 2015;41(12):1922-34.
    PMID: 26057769 DOI: 10.3109/03639045.2015.1052081
    Brain disorders remain the world's leading cause of disability, and account for more hospitalizations and prolonged care than almost all other diseases combined. The majority of drugs, proteins and peptides do not readily permeate into brain due to the presence of the blood-brain barrier (BBB), thus impeding treatment of these conditions.
  14. Arshat H, Kader HA, Ali J, Noor Laily Abu Bakar
    Malays J Reprod Health, 1984 Dec;2(2):83-95.
    PMID: 12280343
  15. Arshat H, Puraviappan AP, Thambu J, Ali J, Harun R
    Malays J Reprod Health, 1984 Jun;2(1):14-9.
    PMID: 12267516
  16. Alhelou Y, Mat Adenan NA, Ali J
    Reprod Biol, 2018 Mar;18(1):40-45.
    PMID: 29279181 DOI: 10.1016/j.repbio.2017.12.003
    A parallel group superiority prospective randomised controlled trial was devised to compare the culture characteristics of human pre-implantation stage embryos during uninterrupted culture in a time lapse incubator (TLI) versus the conventional model of interrupted culture in a standard incubator (SI) under low oxygen tension using a single step medium. 221 patients aged 35-and-under, 124 patients aged between 36 and 39 and 86 patients aged 40-and-over years were randomised and cultured either in a SI or in a TLI. Patients in the three age groups were distributed between the TLI and SI in a 1:1 ratio. The development of embryos on days 2, 3 and 5, and the clinical pregnancy and implantation rates were recorded. The fertilisation rate, development of day 2 and clinical pregnancy rates were similar in both treatments but the 8-cell development rate in all age groups combined (p = 0.016), blastocyst development rate (p = 0.0022) and the implantation rate (p = 0.0022) was significantly higher for the uninterrupted culture. These findings demonstrated significant differences between the two incubation groups. It also indicated less efficacious embryonic development with age in both treatments which appeared more pronounced in the conventional incubator. In conclusion uninterrupted culture is superior compared to the interrupted incubation culture system.
  17. Alhelou Y, Hamdan M, Razali N, Adenan N, Ali J
    BMC Pregnancy Childbirth, 2023 Sep 28;23(1):698.
    PMID: 37770819 DOI: 10.1186/s12884-023-06025-2
    BACKGROUND: Previous studies looked into the connections between pregnancy and the Zona Pellucida (ZP) thickness and Zona Pellucida Thickness Variation (ZPTV), as well as the embryo's radius, circumference, perimeter and global symmetry. However, no research has linked embryo implantation and pregnancy to the percentage of ZP thinning, the reduction in ooplasm volume, and the increase in perivitelline space (PVS) volume. Our objective is to correlate the percentage of ZP thinning, the percentage of ooplasm volume shrinkage and the percentage of PVS increase to the implantation. These data will be used for embryo selection as well as it can be put into a software that will assist embryo selection.

    MATERIALS AND METHODS: Retrospective study included 281 patients, all of them had 2 embryos transferred, 149 patients got pregnant with two gestation sacs and 132 patients did not get pregnant. All of the transferred embryos had the ZP thickness measured several times from time of ICSI till Embryo Transfer (ET), the ooplasm volume was calculated from time of ICSI till two Pronuclei (2PN) fading and the PVS was calculated from the ICSI time till the 2PN fading.

    RESULTS: The first characteristic is the change in the average ZP thickness that decreased by 32.7% + 5.3% at 70 h for the implanted embryos (Group 1) versus 23.6% + 4.8% for non-implanted embryos (Group 2) p = 0.000. The second characteristic is the average reduction in the volume of the ooplasm which is 20.5% + 4.3% in Group 1 versus 15.1% + 5.2% in Group 2, p = 0.000. The third characteristic is the increase in the volume of the PVS which was 38.1% + 7.6% in Group 1 versus 31.6% + 9.7% in Group 2 p = 0.000.

    CONCLUSION: The implanted embryos showed higher percent of ZP thinning, higher percent of ooplasm reduction and higher percent of PVS increase.

  18. Ali J, Kader HA, Hassan K, Arshat H
    Am J Clin Nutr, 1986 Jun;43(6):925-30.
    PMID: 3717068
    Our previous study showed vitamin E deficiency in newborns (69.7%) and mothers at term (85.9%) when the ratio between serum vitamin E in mg/dl and total lipids in g/dl was used as an indicator of vitamin E status. This study was conducted to determine the human milk content of vitamin E. During the first 12 days of lactation milk vitamin E levels remained almost constant (day 1, 0.68 mg/dl; day 12, 0.65 mg/dl), milk total lipid levels increased daily (day 1, 1.11 g/dl; day 12, 3.60 g/dl), and the ratio between milk vitamin E and total lipids dropped steadily (day 1, 1.3; day 12, 0.2). In spite of this drop in vitamin E status, it is unlikely that vitamin E availability will be affected in neonates, because normal neonates absorb milk fats well and this ability increases with age.
  19. Nooshin D, Neda P, Shahdokht S, Ali J
    Malays J Med Sci, 2013 May;20(3):44-50.
    PMID: 23966824
    BACKGROUND: Takayasu arteritis is a condition of unknown aetiology that affects the aorta and its primary branches. The disease has been primarily recognized and described in Asia. The aims of this study were to identify the main clinical, laboratory, and angiographic features of Takayasu arteritis in Iranian patients over a 10 year period from 2000 to 2010.

    METHODS: Data were obtained from angiographic and medical records of patients treated at Shahid-Rajai, Taleghani, and Loghman Hospitals during the above-mentioned time period. The criteria for definitions and findings were those proposed by the American College of Rheumatology.

    RESULTS: A total of 15 patients were identified. The median age at presentation was 36 years and 73.3% of patients were females. Fever was the most common presentation. According to "modified" National Institute of Health criteria, 44.7% of patients were in the acute phase of disease with systemic symptoms such as fever, weight loss, and elevated C-reactive protein (CRP) levels. Immunological markers such as antinuclear antibodies (ANA) and antineutrophil cytoplasmic antibodies (C-ANCA) were absent. The tuberculin test result was positive in 40% of the patients. Vascular bruit was present in 86.7% and hypertension was detected in 53.3% with 13.3% having associated renal artery stenosis. The angiographic manifestations were classified as; type I, cervicobrachial type (26.6%); type II, thoracoabdominal type (20.0%); type III, peripheral type (6.6%); and type IV, generalised type (46.7%). Coronary arteries were involved in three cases, pulmonary in two and renal in two.

    CONCLUSION: Based on our findings, the most common clinical, laboratory and angiographic findings were fever, increased erythrocyte sedimentation rate (ESR) and stenosis, respectively. Because of dangerous consequences of this disease, attention to fever and increased ESR, especially in young women may be helpful for physicians to prevent diagnosis delay.

  20. Alsabery AI, Tayebi T, Kadhim HT, Ghalambaz M, Hashim I, Chamkha AJ
    J Adv Res, 2021 May;30:63-74.
    PMID: 34026287 DOI: 10.1016/j.jare.2020.09.008
    Introduction: Mixed convection flow and heat transfer within various cavities including lid-driven walls has many engineering applications. Investigation of such a problem is important in enhancing the performance of the cooling of electric, electronic and nuclear devices and controlling the fluid flow and heat exchange of the solar thermal operations and thermal storage.

    Objectives: The main aim of this fundamental investigation is to examine the influence of a two-phase hybrid nanofluid approach on mixed convection characteristics including the consequences of varying Richardson number, number of oscillations, nanoparticle volume fraction, and dimensionless length and dimensionless position of the solid obstacle.

    Methods: The migration of composite hybrid nanoparticles due to the nano-scale forces of the Brownian motion and thermophoresis was taken into account. There is an inner block near the middle of the enclosure, which contributes toward the flow, heat, and mass transfer. The top lid cover wall of the enclosure is allowed to move which induces a mixed convection flow. The impact of the migration of hybrid nanoparticles with regard to heat transfer is also conveyed in the conservation of energy. The governing equations are molded into the non-dimensional pattern and then explained using the finite element technique. The effect of various non-dimensional parameters such as the volume fraction of nanoparticles, the wave number of walls, and the Richardson number on the heat transfer and the concentration distribution of nanoparticles are examined. Various case studies for Al2O3-Cu/water hybrid nanofluids are performed.

    Results: The results reveal that the temperature gradient could induce a notable concentration variation in the enclosure.

    Conclusion: The location of the solid block and undulation of surfaces are valuable in the control of the heat transfer and the concentration distribution of the composite nanoparticles.

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