Hybrid Energy Harvesting for Self-powered Implantable Biomedical Devices
Md. Saiful Islam,
Md Kamal Hosain,
Khalifa Almheiri,
Thirein Myo
Issue:
Volume 7, Issue 1, June 2023
Pages:
1-6
Received:
26 December 2022
Accepted:
26 May 2023
Published:
6 June 2023
Abstract: Developing implanted devices is vital for the welfare and safety of well-being because they directly affect lives and safety and provides indication for early recovery. In order to realize the high performance of implantable medical devices, powerful energy sources must be judiciously integrated onto conformal platforms. Energy harvesting from environmental sources and human body motion is becoming increasingly relevant for implantable devices. In this paper, we have developed an efficient energy harvesting technique using low-grade ambient energy sources especially, vibration, and temperature difference, which provides the basis of a self-powered system and allows a wide variety of implanted wearable medical devices to be operated. We have experimentally estimated the harvested energy and validated the amount against the requirements of various miniaturized devices such as cardiac pacemaker, cardiac activity sensing, and electrocardiogram amplifier etc. In addition, this paper investigates the output-harvested energy against the temperature gradient (thermal energy harvesting) and vibrational frequency (vibrational energy harvesting). It is observed that the thermal energy harvesting technique provides higher harvested energy compared to the vibrational counterpart and is linearly proportional to the temperature gradient.
Abstract: Developing implanted devices is vital for the welfare and safety of well-being because they directly affect lives and safety and provides indication for early recovery. In order to realize the high performance of implantable medical devices, powerful energy sources must be judiciously integrated onto conformal platforms. Energy harvesting from envi...
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Antibacterial Effects of Crude Methanolic Extract, Ethyl Acetate Extract and Isolated Compounds from the Fruits of Combretum molle (Combretaceae)
Yakai Fawai,
Dawe Amadou,
Wangso Albert,
Fanta Angele,
Moussa Djaouda,
Taira Vincent,
Doudja Chantal,
Loura Benoit
Issue:
Volume 7, Issue 1, June 2023
Pages:
7-14
Received:
14 May 2023
Accepted:
8 June 2023
Published:
21 June 2023
Abstract: Combretum molle species are extensively used in traditional medicine in the Northern regions of Cameroon against inflammation, infections, diabetes, malaria, bleeding, diarrhea, digestive disorders and others as a diuretic as back pain. This study was conducted to evaluate the antibacterial effects of crude methanolic extract, ethyl acetate extract and isolated compounds from the fruits of Combretum molle using the Muller-Hinton solid medium disc method. Isolation of secondary metabolites from the fruits of Combretum molle was done by the means of usual chromatographic techniques and their structures were confirmed on the basis of spectroscopic data and those available in literature. The first phytochemical exploration of the fruits of Combretum molle afforded sitosterol-3-O-β-D-glucoside (1), oleanolic acid (2), mollic acid (3), mollic acid-3-O-β-D-glucoside (4), 3, 5-dihydroxy-4’,7-dimethoxyflavone (5), and 5,4’-dihydroxy-7-methoxyflavone (6). To the best of our knowledge, compounds (5) and (6) are isolated and reported for the first time from this plant. At the concentration of 25mg/ml methanolic extract, ethyl acetate extract and compounds 3, 4 and 5 presented good antibacterial potential on Salmonella typhimurium (ATCC13311) strain with diameters of the inhibition zone of 18.2±0.1mm, 15.3±0.2mm, 14.2± 0.3mm, 20.2±0.1mm and 15.1± 0.2mm respectively. Also compound 4 and 6 were sensitive on Pseudomonas aeruginosa (ATCC27853) with diameters of inhibition of 18.2±0.2 mm and 14.1± 0.4mm respectively. The results were compared to TE30 (tetracyclin), CIP5 (ciprofloxacin), C30 (chloremphinincol) and NA30 (nalidicic acid) used as references. These results are in agreement with the enthnobotanical uses of the plant and some previous reports on pharmacological activities such as anti-inflammatory, antioxidant, anticancer effects of some isolates and their related previously isolated and identified from several plants.
Abstract: Combretum molle species are extensively used in traditional medicine in the Northern regions of Cameroon against inflammation, infections, diabetes, malaria, bleeding, diarrhea, digestive disorders and others as a diuretic as back pain. This study was conducted to evaluate the antibacterial effects of crude methanolic extract, ethyl acetate extract...
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Evaluation of Acute Toxicity of Lead Acetate, Mercury Chloride, and Their Effects on Fasting Blood Glucose Level in the Common African Toad (Bufo regularis)
Isehunwa Grace Olufunmilayo,
Alabi Alimoh Helen,
Ebeghe Aghoja,
Osifo Innocent Aimen
Issue:
Volume 7, Issue 1, June 2023
Pages:
15-19
Received:
15 June 2023
Accepted:
3 July 2023
Published:
11 July 2023
Abstract: Mercury and lead are heavy metals found in the environment which affect metabolic activity. However, few studies have investigated the acute toxicity tests for mercury chloride and lead acetate in amphibians. The present study evaluated acute toxicity values of lead acetate, mercury chloride and their effects on fasting blood glucose levels in the common African toad Bufo regularis. The acute toxicity test was performed using static renewal bioassays. A total of 90 adult toads of either sex was used for the study. The experiment was divided into two phases. Phase 1 study consisted of 50 toads divided into 10 groups of 5 toads per group. Animals in groups 1-5 were exposed to water (0mg/L), 4mg/L, 8mg/L, 16mg/L and 32mg/L of lead acetate solutions respectively while animals in groups 6-10 were exposed to water (0mg/L), 10mg/L, 20mg/L, 35mg/L, 50mg/L of mercury chloride solutions respectively for 96 hours. Mortality was recorded after 96h and LD50 values were calculated. The second phase of the experiment had 40 toads divided into eight groups of five animals each. Animals in groups 1-4 were exposed to sub lethal concentrations of mercury chloride 0mg/L, 1mg/L, 2mg/L, 3mg/L and 4mg/L while groups 5-8 animals were exposed to sub lethal concentrations of lead acetate 0mg/L, 1mg/L, 2mg/L, 3mg/L, and 4mg/L respectively for 7 days. The blood glucose level was measured one week after exposure using the modified glucose oxidase method. The results of the study showed the 96h LD50 values for mercury chloride was 43mg/L and 15.03mg/L for lead acetate in the common African toad. Acute exposure to low dose mercury chloride and lead acetate solutions caused a significant increase in fasting glucose levels of the toads compared with the controls. In conclusion, the study showed the 96h LD50 values for lead acetate was 15.03mg/L and 43mg/L for mercury chloride in the common African toad. This study also, demonstrated that acute exposure to low dose lead acetate and mercury chloride solutions caused harmful effects and increased fasting glucose levels in the common African toad. Therefore, it is suggested that exposure to lead acetate and mercury chloride be avoided.
Abstract: Mercury and lead are heavy metals found in the environment which affect metabolic activity. However, few studies have investigated the acute toxicity tests for mercury chloride and lead acetate in amphibians. The present study evaluated acute toxicity values of lead acetate, mercury chloride and their effects on fasting blood glucose levels in the ...
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