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Lipid-Based Ionic-Liquid-Mediated Nanodispersions as Biocompatible Carriers for the Enhanced Transdermal Delivery of a Peptide Drug

Uddin S, Islam MR, Chowdhury MR, Wakabayashi R, Kamiya N, Moniruzzaman M, et al.

ACS Appl Bio Mater, 2021 08 16;4(8):6256-6267.
PMID: 35006923 DOI: 10.1021/acsabm.1c00563

Lipid-based biocompatible ionic liquids (LBILs) have attracted attention as carriers in transdermal drug delivery systems (TDDSs) because of their lipophilic character. In this study, we report the formulation of a peptide-LBIL complex microencapsulated in an oil phase as a potential carrier for the transdermal delivery of leuprolide acetate as a model hydrophilic peptide. The peptide-LBIL complexes were prepared via a water-in-oil emulsion composed of 1,2-dimyristoyl-sn-glycerol-3-ethyl-phosphatidylcholine (EDMPC), a fatty acid (stearic, oleic, and linoleic acid)-based LBIL, and cyclohexane followed by freeze-drying to remove the water and cyclohexane. Then, the peptide-LBIL complexes were nanodispersed and stabilized in isopropyl myristate (IPM) using sorbitol laurate (Span-20). Ionic-liquid-in-oil nanodispersions (IL/O-NDs) were prepared with varying weight ratios of LBILs and Span-20 as the surfactant and the cosurfactant, respectively. Keeping the overall surfactant constant at 10 wt % in IPM, a 5:5 wt % ratio of surfactant (IL) and cosurfactant (Span-20) in the IL/O-NDs significantly (p < 0.0001) increased the physiochemical stability, drug-loading capacity, and drug encapsulation efficiency. The in vitro and in vivo peptide delivery across the skin was increased significantly (p < 0.0001) using IL/O-NDs, compared with non-IL-treated groups. Of all of the LBIL-based formulations, [EDMPC][Linoleate]/O-ND was considered the most preferable for a TDDS based on the pharmacokinetic parameters. The transdermal delivery flux with [EDMPC][Linoleate]/O-ND was increased 65-fold compared with the aqueous delivery vehicle. The IL/O-NDs were able to deform the lipid and protein arrangements of the skin layers to enhance the transdermal permeation of the peptide. In vitro and in vivo cytotoxicity studies of the IL/O-NDs revealed the biocompatibility of the LBIL-based formulations. These results indicated that IL/O-NDs are promising biocompatible carriers for lipid-peptide TDDSs.
Modification with Conventional Surfactants to Improve a Lipid-Based Ionic-Liquid-Associated Transcutaneous Anticancer Vaccine

Uddin S, Islam MR, Moshikur RM, Wakabayashi R, Moniruzzaman M, Goto M

Molecules, 2023 Mar 27;28(7).
PMID: 37049732 DOI: 10.3390/molecules28072969

Transcutaneous vaccination is one of the successful, affordable, and patient-friendly advanced immunization approaches because of the presence of multiple immune-responsive cell types in the skin. However, in the absence of a preferable facilitator, the skin's outer layer is a strong impediment to delivering biologically active foreign particles. Lipid-based biocompatible ionic-liquid-mediated nanodrug carriers represent an expedient and distinct strategy to permit transdermal drug delivery; with acceptable surfactants, the performance of drug formulations might be further enhanced. For this purpose, we formulated a lipid-based nanovaccine using a conventional (cationic/anionic/nonionic) surfactant loaded with an antigenic protein and immunomodulator in its core to promote drug delivery by penetrating the skin and boosting drug delivery and immunogenic cell activity. In a follow-up investigation, a freeze-dry emulsification process was used to prepare the nanovaccine, and its transdermal delivery, pharmacokinetic parameters, and ability to activate autoimmune cells in the tumor microenvironment were studied in a tumor-budding C57BL/6N mouse model. These analyses were performed using ELISA, nuclei and HE staining, flow cytometry, and other biological techniques. The immunomodulator-containing nanovaccine significantly (p < 0.001) increased transdermal drug delivery and anticancer immune responses (IgG, IgG1, IgG2, CD8+, CD207+, and CD103+ expression) without causing cellular or biological toxicity. Using a nanovaccination approach, it is possible to create a more targeted and efficient delivery system for cancer antigens, thereby stimulating a stronger immune response compared with conventional aqueous formulations. This might lead to more effective therapeutic and preventative outcomes for patients with cancer.
Fulltext Self-reported tobacco smoking practices among medical students and their perceptions towards training about tobacco smoking in medical curricula: A cross-sectional, questionnaire survey in Malaysia, India, Pakistan, Nepal, and Bangladesh

Sreeramareddy CT, Suri S, Menezes RG, Kumar HN, Rahman M, Islam MR, et al.

Subst Abuse Treat Prev Policy, 2010;5:29.
PMID: 21080923 DOI: 10.1186/1747-597X-5-29

BACKGROUND: Tobacco smoking issues in developing countries are usually taught non-systematically as and when the topic arose. The World Health Organisation and Global Health Professional Student Survey (GHPSS) have suggested introducing a separate integrated tobacco module into medical school curricula. Our aim was to assess medical students' tobacco smoking habits, their practices towards patients' smoking habits and attitude towards teaching about smoking in medical schools.
METHODS: A cross-sectional questionnaire survey was carried out among final year undergraduate medical students in Malaysia, India, Nepal, Pakistan, and Bangladesh. An anonymous, self-administered questionnaire included items on demographic information, students' current practices about patients' tobacco smoking habits, their perception towards tobacco education in medical schools on a five point Likert scale. Questions about tobacco smoking habits were adapted from GHPSS questionnaire. An 'ever smoker' was defined as one who had smoked during lifetime, even if had tried a few puffs once or twice. 'Current smoker' was defined as those who had smoked tobacco product on one or more days in the preceding month of the survey. Descriptive statistics were calculated.
RESULTS: Overall response rate was 81.6% (922/1130). Median age was 22 years while 50.7% were males and 48.2% were females. The overall prevalence of 'ever smokers' and 'current smokers' was 31.7% and 13.1% respectively. A majority (> 80%) of students asked the patients about their smoking habits during clinical postings/clerkships. Only a third of them did counselling, and assessed the patients' willingness to quit. Majority of the students agreed about doctors' role in tobacco control as being role models, competence in smoking cessation methods, counseling, and the need for training about tobacco cessation in medical schools. About 50% agreed that current curriculum teaches about tobacco smoking but not systematically and should be included as a separate module. Majority of the students indicated that topics about health effects, nicotine addiction and its treatment, counselling, prevention of relapse were important or very important in training about tobacco smoking.
CONCLUSION: Medical educators should consider revising medical curricula to improve training about tobacco smoking cessation in medical schools. Our results should be supported by surveys from other medical schools in developing countries of Asia.
Fulltext Analyzing the Impact of Demographic Variables on Spreading and Forecasting COVID-19

Sharif O, Islam MR, Hasan MZ, Kabir MA, Hasan ME, AlQahtani SA, et al.

J Healthc Inform Res, 2022;6(1):72-90.
PMID: 34549163 DOI: 10.1007/s41666-021-00105-8

The aim of this study is to analyse the coronavirus disease 2019 (COVID-19) outbreak in Bangladesh. This study investigates the impact of demographic variables on the spread of COVID-19 as well as tries to forecast the COVID-19 infected numbers. First of all, this study uses Fisher's Exact test to investigate the association between the infected groups of COVID-19 and demographical variables. Second, it exploits the ANOVA test to examine significant difference in the mean infected number of COVID-19 cases across the population density, literacy rate, and regions/divisions in Bangladesh. Third, this research predicts the number of infected cases in the epidemic peak region of Bangladesh for the year 2021. As a result, from the Fisher's Exact test, we find a very strong significant association between the population density groups and infected groups of COVID-19. And, from the ANOVA test, we observe a significant difference in the mean infected number of COVID-19 cases across the five different population density groups. Besides, the prediction model shows that the cumulative number of infected cases would be raised to around 500,000 in the most densely region of Bangladesh, Dhaka division.
Fulltext Stem Cell Transplantation Therapy and Neurological Disorders: Current Status and Future Perspectives

Rahman MM, Islam MR, Islam MT, Harun-Or-Rashid M, Islam M, Abdullah S, et al.

Biology (Basel), 2022 Jan 17;11(1).
PMID: 35053145 DOI: 10.3390/biology11010147

Neurodegenerative diseases are a global health issue with inadequate therapeutic options and an inability to restore the damaged nervous system. With advances in technology, health scientists continue to identify new approaches to the treatment of neurodegenerative diseases. Lost or injured neurons and glial cells can lead to the development of several neurological diseases, including Parkinson's disease, stroke, and multiple sclerosis. In recent years, neurons and glial cells have successfully been generated from stem cells in the laboratory utilizing cell culture technologies, fueling efforts to develop stem cell-based transplantation therapies for human patients. When a stem cell divides, each new cell has the potential to either remain a stem cell or differentiate into a germ cell with specialized characteristics, such as muscle cells, red blood cells, or brain cells. Although several obstacles remain before stem cells can be used for clinical applications, including some potential disadvantages that must be overcome, this cellular development represents a potential pathway through which patients may eventually achieve the ability to live more normal lives. In this review, we summarize the stem cell-based therapies that have been explored for various neurological disorders, discuss the potential advantages and drawbacks of these therapies, and examine future directions for this field.
Association between high-risk fertility behaviours and the likelihood of chronic undernutrition and anaemia among married Bangladeshi women of reproductive age

Rahman M, Islam MJ, Haque SE, Saw YM, Haque MN, Duc NH, et al.

Public Health Nutr, 2017 Feb;20(2):305-314.
PMID: 27608854 DOI: 10.1017/S136898001600224X

OBJECTIVE: To explore the association between high-risk fertility behaviours and the likelihood of chronic undernutrition, anaemia and the coexistence of anaemia and undernutrition among women of reproductive age.
DESIGN: The 2011 Bangladesh Demographic and Health Survey, conducted from 8 July to 27 December 2011.
SETTING: Selected urban and rural areas of Bangladesh.
SUBJECTS: A total of 2197 ever-married women living with at least one child younger than 5 years. Exposure was determined from maternal reports of high-risk fertility behaviours. We considered three parameters, maternal age at the time of delivery, birth order and birth interval, to define the high-risk fertility behaviours. Chronic undernutrition, anaemia and the coexistence of anaemia and undernutrition among women were the outcome variables.
RESULTS: A substantial percentage of women were exposed to have a high-risk fertility pattern (41·8 %); 33·0 % were at single high-risk and 8·8 % were at multiple high-risk. After adjusting for relevant covariates, high-risk fertility behaviours were associated with increased likelihood of chronic undernutrition (adjusted relative risk; 95 % CI: 1·22; 1·03, 1·44), anaemia (1·12; 1·00, 1·25) and the coexistence of anaemia and undernutrition (1·52; 1·17, 1·98). Furthermore, multiple high-risk fertility behaviours appeared to have more profound consequences on the outcome measured.
CONCLUSIONS: Maternal high-risk fertility behaviours are shockingly frequent practices among women in Bangladesh. High-risk fertility behaviours are important predictors of the increased likelihood of women's chronic undernutrition, anaemia and the coexistence of anaemia and undernutrition.
Public Health Services for Foreign Workers in Malaysia

Noh NA, Wahab HA, Bakar Ah SH, Islam MR

Soc Work Public Health, 2016 Aug-Sep;31(5):419-30.
PMID: 27177326 DOI: 10.1080/19371918.2015.1125321

The objective of this study was to know the status of the foreign workers' access to public health services in Malaysia based on their utilization pattern. The utilization pattern covered a number of areas, such as frequency of using health services, status of using health services, choice and types of health institutions, and cost of health treatment. The study was conducted on six government hospitals in the Klang Valley area in Kuala Lumpur, Malaysia. Data were collected from 600 foreign patients working in the country, using an interview method with a structured questionnaire. The results showed that the foreign workers' access to public health services was very low. The findings would be an important guideline to formulate an effective health service policy for the foreign workers in Malaysia.
Normobaric hyperoxia treatment prevents early alteration in dopamine level in mice striatum after fluid percussion injury: a biochemical approach

Muthuraju S, Islam MR, Pati S, Jaafar H, Abdullah JM, Yusoff KM

Int J Neurosci, 2015;125(9):686-92.
PMID: 25180987 DOI: 10.3109/00207454.2014.961065

Dopamine (DA) is one of the key neurotransmitters in the striatum, which is functionally important for a variety of cognitive and motor behaviours. It is known that the striatum is vulnerable to damage from traumatic brain injury (TBI). However, a therapeutic approach has not yet been established to treat TBI. Hence, the present work aimed to evaluate the ability of Normobaric hyperoxia treatment (NBOT) to recover dopaminergic neurons following a fluid percussion injury (FPI) as a TBI experimental animal model. To examine this, mice were divided into four groups: (i) Control, (ii) Sham, (iii) FPI and (iv) FPI+NBOT. Mice were anesthetized and surgically prepared for FPI in the striatum and immediate exposure to NBOT at various time points (3, 6, 12 and 24 h). Dopamine levels were then estimated post injury by utilizing a commercially available ELISA method specific to DA. We found that DA levels were significantly reduced at 3 h, but there was no reduction at 6, 12 and 24 h in FPI groups when compared to the control and sham groups. Subjects receiving NBOT showed consistent increased DA levels at each time point when compared with Sham and FPI groups. These results suggest that FPI may alter DA levels at the early post-TBI stages but not in later stages. While DA levels increased in 6, 12 and 24 h in the FPI groups, NBOT could be used to accelerate the prevention of early dopaminergic neuronal damage following FPI injury and improve DA levels consistently.
Fulltext Social Stigma as a Barrier to Covid-19 Responses to Community Well-Being in Bangladesh

Mahmud A, Islam MR

Int J Community Wellbeing, 2021;4(3):315-321.
PMID: 34723103 DOI: 10.1007/s42413-020-00071-w

This commentary looks at the social stigma as a barrier to Covid-19 responses to community well-being in Bangladesh. The Covid-19 in Bangladesh particular the way the people respond this has many dimensions to view from sociological perspective. The main objective of this commentary is to analysis how this response is related to social stigma. Gathering information from the recent literature, results showed that there are number of causes around such stigma that include misinformation, feeling of insecurity, fear of responsibility, administrative malfunction, and lack of trust on treatment. These causes of stigma have number of forms such as humor-prone stigma, residential stigma, organizational stigma, community-stigma, and apathetical stigma. Results also show that there are many effects of stigma such as health-risks, harassment, discrimination, life-insecurity, psychological disorder, loss of social capital and emotional capital, shattering family bond and social solidarity that work as barrier to community well-being. This commentary recommends to overcome the barriers through strengthening and decentralization of the COVID-19 medical facilities including testing, tracing, formal quarantining, and special treatment for coronavirus in coronavirus hospitals by allocating a large figure of the state budget and also by taking initiatives of public-private partnership for health management.
Fulltext Chronology of Fabry-Perot interferometer fiber-optic sensors and their applications: a review

Islam MR, Ali MM, Lai MH, Lim KS, Ahmad H

Sensors (Basel), 2014;14(4):7451-88.
PMID: 24763250 DOI: 10.3390/s140407451

Optical fibers have been involved in the area of sensing applications for more than four decades. Moreover, interferometric optical fiber sensors have attracted broad interest for their prospective applications in sensing temperature, refractive index, strain measurement, pressure, acoustic wave, vibration, magnetic field, and voltage. During this time, numerous types of interferometers have been developed such as Fabry-Perot, Michelson, Mach-Zehnder, Sagnac Fiber, and Common-path interferometers. Fabry-Perot interferometer (FPI) fiber-optic sensors have been extensively investigated for their exceedingly effective, simple fabrication as well as low cost aspects. In this study, a wide variety of FPI sensors are reviewed in terms of fabrication methods, principle of operation and their sensing applications. The chronology of the development of FPI sensors and their implementation in various applications are discussed.
Distribution of prosaposin mRNA in the central nervous system of the pigeon (Columba livia)

Islam MR, Abdullah JM, Atoji Y

Anat Histol Embryol, 2013 Aug;42(4):257-65.
PMID: 22994540 DOI: 10.1111/ahe.12009

Bioassay and immunohistochemical studies have detected the presence of prosaposin in the central nervous system (CNS) of mammals. Here, first time, we have determined the partial cDNA sequence of pigeon prosaposin and mapped the distribution of its mRNA in the pigeon CNS. The predicted amino acid sequence of pigeon prosaposin showed 93 and 60% identity to chicken and human prosaposin, respectively. In situ hybridization, autoradiograms showed that the prosaposin mRNA expression was found in the olfactory bulb, prepiriform cortex, Wulst, mesopallium, nidopallium, hippocampal formation, thalamus, tuberis nucleus, pre-tectal nucleus, nucleus mesencephalicus lateralis, pars dorsalis, nucleus isthmi, pars parvocellularis and magnocellularis, Edinger-Westphal nucleus, optic tectum, cerebellar cortex and nuclei, vestibular nuclei and gray matter of the spinal cord. These results suggest that the cDNA sequence of pigeon prosaposin is comparable to other vertebrates, and the general distribution pattern of prosaposin mRNA resembles those are found in mammals.
Fulltext Road traffic accidents in Bangladesh: Why people have poor knowledge and awareness about traffic rules?

Islam MR, Ali Khan MM, Hossain MM, C Mani KK, Min RM

Int J Crit Illn Inj Sci, 2020 06 08;10(2):70-75.
PMID: 32904453 DOI: 10.4103/IJCIIS.IJCIIS_65_19

Purpose: The study aimed to identify the characteristics of road traffic accident (RTA) and to determine the role of different socioeconomic and demographic factors on the knowledge and awareness about traffic rules among people in Bangladesh.
Study Design: This was a cross-sectional study.
Methods: To conduct this study, 700 primary data were collected from respondents who were involved in RTA by interviewing in medical college hospitals and several private clinics of Dhaka, Rajshahi, and Khulna division in Bangladesh. For the achievement of the objective, the Chi-square test, Cramer's V correlation, and the logistic regression model have been applied in this study.
Results: Traffic rules violation was identified as the second-most important reason behind RTA. Respondent's age, gender, residence, education, occupation, awareness about RTA, etc., were significantly associated with having knowledge and awareness about traffic rules. The result of multivariate analysis showed that respondent's age (<30: odds ratio [OR] = 2.019, confidence interval [CI]: 1.377-2.960); residence (rural: OR = 0.288, CI: 0.193-0.431); education (literate: OR = 5.064, CI: 3.332-7.698); and categories of victims (driver: OR = 2.731, CI: 1.676-4.450 and passenger: 1.869, CI: 1.198-2.916) were the vital predictors of having knowledge and awareness about traffic rules.
Conclusions: By imposing strict traffic act, increasing public awareness through various types of education and awareness/outreach about traffic rules-related program, especially in rural areas, by strictly prohibiting the license giving to unskilled drivers or unfit vehicles, RTA can be minimized.
Choline and amino acid based biocompatible ionic liquid mediated transdermal delivery of the sparingly soluble drug acyclovir

Islam MR, Chowdhury MR, Wakabayashi R, Tahara Y, Kamiya N, Moniruzzaman M, et al.

Int J Pharm, 2020 May 30;582:119335.
PMID: 32311469 DOI: 10.1016/j.ijpharm.2020.119335

Transdermal delivery of drugs is more challenging for drugs that are insoluble or sparingly soluble in water and most organic solvents. To overcome this problem, ionic liquid (IL)-mediated ternary systems have been suggested as potential drug carriers. Here, we report potent ternary (IL-EtOH-IPM) systems consisting of biocompatible ILs, ethanol (EtOH), and isopropyl myristate (IPM) that can dissolve a significant amount of the sparingly soluble drug acyclovir (ACV). The ternary systems were optically transparent and thermodynamically stable with a wide range of IL pertinence. An in vitro drug permeation study showed that the ILs in the ternary systems dramatically enhanced ACV permeation into and across the skin. Fourier Transform Infrared spectroscopy of the stratum corneum (sc) after treatment with ternary systems showed that the skin barrier function was reduced by disturbance of the regularly ordered arrangement of corneocytes and modification of the surface properties of the sc during permeation. Histological analysis, and skin irritation studies using a reconstructed human epidermis model showed the safety profile of the ternary system, and there were no significant changes in the structures of the sc, epidermis, and dermis. Therefore, ternary systems containing biocompatible ILs are promising for transdermal delivery of insoluble or sparingly soluble drugs.
Fulltext Ionic Liquid-In-Oil Microemulsions Prepared with Biocompatible Choline Carboxylic Acids for Improving the Transdermal Delivery of a Sparingly Soluble Drug

Islam MR, Chowdhury MR, Wakabayashi R, Kamiya N, Moniruzzaman M, Goto M

Pharmaceutics, 2020 Apr 24;12(4).
PMID: 32344768 DOI: 10.3390/pharmaceutics12040392

The transdermal delivery of sparingly soluble drugs is challenging due to of the need for a drug carrier. In the past few decades, ionic liquid (IL)-in-oil microemulsions (IL/O MEs) have been developed as potential carriers. By focusing on biocompatibility, we report on an IL/O ME that is designed to enhance the solubility and transdermal delivery of the sparingly soluble drug, acyclovir. The prepared MEs were composed of a hydrophilic IL (choline formate, choline lactate, or choline propionate) as the non-aqueous polar phase and a surface-active IL (choline oleate) as the surfactant in combination with sorbitan laurate in a continuous oil phase. The selected ILs were all biologically active ions. Optimized pseudo ternary phase diagrams indicated the MEs formed thermodynamically stable, spherically shaped, and nano-sized (<100 nm) droplets. An in vitro drug permeation study, using pig skin, showed the significantly enhanced permeation of acyclovir using the ME. A Fourier transform infrared spectroscopy study showed a reduction of the skin barrier function with the ME. Finally, a skin irritation study showed a high cell survival rate (>90%) with the ME compared with Dulbecco's phosphate-buffered saline, indicates the biocompatibility of the ME. Therefore, we conclude that IL/O ME may be a promising nano-carrier for the transdermal delivery of sparingly soluble drugs.
Determinants of Hepatitis B Virus (HBV) Infection Among University Students in Central Bangladesh

Islam MR, Sheba NH, Islam MT, Rahman MM, Hossain S, Hussain MA, et al.

J Community Health, 2022 Feb;47(1):136-142.
PMID: 34491507 DOI: 10.1007/s10900-021-01025-9

This study aimed to determine the seroprevalence and determinants of hepatitis B virus (HBV) infection among university students in Bangladesh. This cross-sectional study was conducted among 614 students from five universities in central Bangladesh. Data were collected on demographic information, immunization history, medical and blood transfusion history through the face-to-face interview. Blood samples were collected and screened for anti-HBsAg using ELISA, HBsAg Rapid Test-cassette, and immune chromatographic test. The overall seroprevalence of HBV infection was 5.0%, and vaccination coverage was 19.2% among the participants. Students having a history of surgery (OR 11.004, 95% CI 3.211-37.707), blood transfusion (OR 5.651, 95% CI 0.965-33.068), being married (OR 4.776, 95% CI 1.508-15.127), and not being vaccinated (OR 9.825, 95% CI 1.130-85.367) were at higher risk of being infected by HBV. This study showed the endemicity of HBV infection among the Bangladeshi population. Marriage, surgical or blood transfusion history, not being vaccinated were the determinants of HBV infection within the study population. Public health initiatives for preventing HBV infection at the university levels should be envisaged.
Fulltext Penta band single negative meta-atom absorber designed on square enclosed star-shaped modified split ring resonator for S-, C-, X- and Ku- bands microwave applications

Islam MR, Islam MT, Moniruzzaman M, Samsuzzaman M, Arshad H

Sci Rep, 2021 Apr 22;11(1):8784.
PMID: 33888759 DOI: 10.1038/s41598-021-87958-6

This paper represents a penta band square enclosed star-shaped modified split ring resonator (SRR) based single negative meta-atom absorber (MAA) for multi-band microwave regime applications. FR-4 low-cost material has been used as a substrate to make the MAA unit cell with 0.101λ0 × 0.101λ0 of electrical size, where λ0 is the wavelength calculated at the lower resonance frequency of 3.80 GHz. There are two outer square split ring and one inner star ring shape resonator of 0.035 mm thickness of copper placed on the one side, and another side of the substrate has full copper to construct the desired unit cell. The MAA unit cell provides five absorption peaks of 97.87%, 93.65%, 92.66%, 99.95%, and 99.86% at the frequencies of 3.80, 5.65, 8.45, 10.82, and 15.92 GHz, respectively, which covers S-, C-, X-, and Ku- bands. The properties of MAA have been investigated and analyzed in the E-, H-fields and surface current. The EMR and highest Q factor of the designed MAA is 9.87 and 30.41, respectively, and it shows a single negative (SNG) property. Different types of parametric analysis have been done to show the better performance of absorption. Advanced Designed System (ADS) software has been used for equivalent circuit to verify the simulated S11 result obtained from the CST-2019 software. Experimental outcomes of the MAA unit cell have a good deal with the simulated result and measured result of the 24 × 20 array of unit cells also shown. Since the unit cell provides superior EMR, excellent Q-factor, and highest absorption so the recommended MAA can be effectively used as a penta band absorber in microwave applications, like notch filtering, sensing, reducing the unintended noise generated with the copper component of the satellite and radar antennas.
Fulltext Metamaterial based on an inverse double V loaded complementary square split ring resonator for radar and Wi-Fi applications

Islam MR, Islam MT, Soliman MS, Baharuddin MH, Mat K, Moubark AM, et al.

Sci Rep, 2021 Nov 05;11(1):21782.
PMID: 34741089 DOI: 10.1038/s41598-021-01275-6

In this research paper, an inverse double V loaded complementary square split ring resonator based double negative (DNG) metamaterial has been developed and examined numerically and experimentally. The electromagnetic (EM) properties of the proposed inverse double V-structure were calculated using computer simulation technology (CST-2019) and the finite integration technique (FIT). The designed metamaterial provides three resonance frequencies are 2.86, 5, and 8.30 GHz, covering S-, C-, and X-bands. The total size of the recommended unit cell is 8 [Formula: see text] 8 [Formula: see text] 1.524 mm3, and a high effective medium ratio (EMR) value of 13.11 was found from it. The - 10 dB bandwidths of this structure are 2.80 to 2.91, 4.76 to 5.17, and 8.05 to 8.42 GHz. The proposed structure's novelty is its small size, simple resonator structure, which provides double negative characteristics, high EMR, maximum coverage band, and required resonance frequencies. Wi-Fi network speeds are generally faster when frequencies in the 5 GHz band are used. Since the proposed structure provides a 5 GHz frequency band, hence the suggested metamaterial can be used in Wi-Fi for high bandwidth and high-speed applications. The marine radars operate in X-band, and weather radar works in S-band. Since the designed cell provides two more resonance frequencies, i.e., 2.86 GHz (S-band) and 8.30 GHz (X-band), the proposed metamaterial could be used in weather radar and marine radar. The design process and various parametric studies have been analyzed in this article. The equivalent circuit is authenticated using the advanced design system (ADS) software compared with CST simulated result. The surface current, E-field, and H-field distributions have also been analyzed. Different types of array structure, i.e., 1 [Formula: see text] 2, 2 [Formula: see text] 2, 3 [Formula: see text] 3, 4 [Formula: see text] 4, and 20 [Formula: see text] 25 is examined and validated by the measured result. The simulated and measured outcome is an excellent agreement for the inverse double V loaded CSSRR unit cell and array. We showed the overall performance of the suggested structure is better than the other structures mentioned in the paper. Since the recommended metamaterial unit cell size is small, provides desired resonance frequency, gives a large frequency band and high EMR value; hence the suggested metamaterial can be highly applicable for Radar and Wi-Fi.
Insulin Transdermal Delivery System for Diabetes Treatment Using a Biocompatible Ionic Liquid-Based Microemulsion

Islam MR, Uddin S, Chowdhury MR, Wakabayashi R, Moniruzzaman M, Goto M

ACS Appl Mater Interfaces, 2021 Sep 15;13(36):42461-42472.
PMID: 34460218 DOI: 10.1021/acsami.1c11533

Since injection administration for diabetes is invasive, it is important to develop an effective transdermal method for insulin. However, transdermal delivery remains challenging owing to the strong barrier function of the stratum corneum (SC) of the skin. Here, we developed ionic liquid (IL)-in-oil microemulsion formulations (MEFs) for transdermal insulin delivery using choline-fatty acids ([Chl][FAs])-comprising three different FAs (C18:0, C18:1, and C18:2)-as biocompatible surface-active ILs (SAILs). The MEFs were successfully developed using [Chl][FAs] as surfactants, sorbitan monolaurate (Span-20) as a cosurfactant, choline propionate IL as an internal polar phase, and isopropyl myristate as a continuous oil phase. Ternary phase behavior, dynamic light scattering, and transmission electron microscopy studies revealed that MEFs were thermodynamically stable with nanoparticle size. The MEFs significantly enhanced the transdermal permeation of insulin via the intercellular route by compromising the tight lamellar structure of SC lipids through a fluidity-enhancing mechanism. In vivo transdermal administration of low insulin doses (50 IU/kg) to diabetic mice showed that MEFs reduced blood glucose levels (BGLs) significantly compared with a commercial surfactant-based formulation by increasing the bioavailability of insulin in the systemic circulation and sustained the insulin level for a much longer period (half-life > 24 h) than subcutaneous injection (half-life 1.32 h). When [Chl][C18:2] SAIL-based MEF was transdermally administered, it reduced the BGL by 56% of its initial value. The MEFs were biocompatible and nontoxic (cell viability > 90%). They remained stable at room temperature for 3 months and their biological activity was retained for 4 months at 4 °C. We believe SAIL-based MEFs will alter current approaches to insulin therapy and may be a potential transdermal nanocarrier for protein and peptide delivery.
Fulltext Age-dependent Electroencephalographic Differences in the Genetic Absence Epilepsy Rats from Strasbourg (GAERS) Model of Absence Epilepsy

Islam MR, Abdullah JM

Malays J Med Sci, 2014 Dec;21(Spec Issue):34-40.
PMID: 25941461 MyJurnal

Genetic Absence Epilepsy Rats from Strasbourg (GAERS) are a prognostic genetic model of absence epilepsy. This model displays the electro-clinical, behavioural, and pharmacological features of absence seizures. Although GAERS share typical characteristics, including spike-and-wave discharges (SWDs) in the electroencephalography (EEG), age-dependent studies with these animals have not yet been reported. The aim of the present study is to perform a systematic comparison contrasting the SWDs of young and older GAERS, in terms of the number, duration, frequency, and waveform morphology of the discharges, as well as the pre-SWD EEG characteristics, using identical measurement and analysis techniques. The number, cumulative total duration and mean duration of SWDs were significantly higher in young GAERS (4 to 6 months) compared to older GAERS (12 to 14 months). Furthermore, the SWD spectra and average SWD waveforms indicated that a single cycle of the SWD contains more energy in faster components, such as increased spikes and higher power, in the SWDs of the young GAERS. Additionally, older GAERS showed weak amplitude spikes in SWDs and higher power pre-SWDs. These clear morphological differences in the EEGs of young and older GAERS rats should be further examined in future studies that explore new dimensions of genetic absence epilepsy.
Fulltext Force-Invariant Improved Feature Extraction Method for Upper-Limb Prostheses of Transradial Amputees

Islam MJ, Ahmad S, Haque F, Reaz MBI, Bhuiyan MAS, Islam MR

Diagnostics (Basel), 2021 May 07;11(5).
PMID: 34067203 DOI: 10.3390/diagnostics11050843

A force-invariant feature extraction method derives identical information for all force levels. However, the physiology of muscles makes it hard to extract this unique information. In this context, we propose an improved force-invariant feature extraction method based on nonlinear transformation of the power spectral moments, changes in amplitude, and the signal amplitude along with spatial correlation coefficients between channels. Nonlinear transformation balances the forces and increases the margin among the gestures. Additionally, the correlation coefficient between channels evaluates the amount of spatial correlation; however, it does not evaluate the strength of the electromyogram signal. To evaluate the robustness of the proposed method, we use the electromyogram dataset containing nine transradial amputees. In this study, the performance is evaluated using three classifiers with six existing feature extraction methods. The proposed feature extraction method yields a higher pattern recognition performance, and significant improvements in accuracy, sensitivity, specificity, precision, and F1 score are found. In addition, the proposed method requires comparatively less computational time and memory, which makes it more robust than other well-known feature extraction methods.

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