116 research outputs found
Morphological and morphometric studies of the aorta, pulmonary trunk, and heart of streptozotocin-induced diabetic Wistar rats
Micro-anatomical changes in the aorta, pulmonary trunk, and left ventricle of
Wistar rats were studied after the administration of streptozotocin. Twenty
adult Rattus norvegicus were randomly assigned into two groups (control and
diabetic) of ten rats each. Diabetes mellitus was experimentally induced in the
diabetic group of rats by daily intra-peritoneal administration of multiple doses
of 40 mg/kg streptozotocin dissolved in 0.1 M sodium citrate buffer for five
consecutive days. The control group was given the equivalent volume of citrate
buffer. The animals were monitored for four weeks after streptozotocin administration.
Post sacrifice, the left ventricle, aorta, and pulmonary trunk were
excised, weighed, and fixed by immersion in 10% formol saline. The tissues
were processed for paraffin embedding, and sections of 6 μm thickness were
produced and stained with H & E for general histological observations, and
Verhoeff-van Gieson elastic fibre stain to demonstrate elastic fibres in these
cardiovascular structures. The data obtained were analyzed with descriptive
and inferential statistics. Histopathological and morphometric examinations of
the stained sections showed a significant increase in the thickness of the tunica
intima of aorta (t = –7.49; df = 9; p < 0.05) and pulmonary trunk (t = –10.81;
df = 9; p < 0.05) in diabetic rats (14.59 ± 1.189 mm and 11.307 ± 0.863 mm,
respectively) when compared to that of the control group (3.62 ± 0.353 mm
and 3.22 ± 0.244 mm, respectively). In addition, the distribution of elastic and
collagen fibres was sparse in the hearts of the diabetic group when compared
to that of the control group. The findings of this study demonstrated that diabetes
mellitus might cause some alterations in the microanatomy of cardiovascular
structures
Histomorphological and morphometric studies of the pancreatic islet cells of diabetic rats treated with extracts of Annona muricata
Microanatomical changes in the pancreatic islet cells of streptozotocin induced
diabetic Wistar rats were studied after treatment with methanolic extracts of
Annona muricata leaves. Thirty adult Wistar rats were randomly assigned into
three groups (control, untreated diabetic group, and A. muricata-treated diabetic
group) of ten rats each. Diabetes mellitus was experimentally induced in
groups B and C by a single intra-peritoneal injection of 80 mg/kg streptozotocin
dissolved in 0.1 M citrate buffer. The control rats were intraperitoneally
injected with an equivalent volume of citrate buffer. Daily intra peritoneal injections
of 100 mg/kg A. muricata were administered to group C rats for two
weeks. Post sacrifice the pancreases of the rats were excised and fixed in Bouin’s
fluid. The tissues were processed for paraffin embedding and sections of 5 μm
thickness were produced and stained with H & E, Gomori aldehyde fuchsin,
and chrome alum haematoxylin-phloxine for demonstration of the β-cells of
islets of pancreatic islets. Histomorphological and morphometric examination of
the stained pancreatic sections showed a significant increase in the number,
diameter, and volume of the β-cells of pancreatic islets of the A. muricata-treated
group (5.67 ± 0.184 N/1000 μm2, 5.38 ± 0.093 μm and 85.12 ± 4.24 μm3,
respectively) when compared to that of the untreated diabetic group of rats
(2.85 ± 0.361 N/1000 μm2, 2.85 ± 0.362 μm and 69.56 ± 5.216 μm3, respectively).
The results revealed regeneration of the β-cells of islets of pancreatic islet
of rats treated with extract of A. muricata. (Folia Morphol 2010; 69, 2: 92-100
BIOCHEMICAL CHANGES IN STREPTOZOTOCIN-INDUCED DIABETIC RATS AFTER TREATMENT WITH ETHANOLIC LEAF EXTRACT OF Croton Zambesicus (Müll. Arg.)
Objective: This study was designed to evaluate the effect of ethanolic leaf extract of C.
zambesicus on total protein (TP), albumin (ALB), globulin (GLO), lactate dehydrogenase (LDH) and
glucose-6-phosphate dehydrogenase (G6PDH) in streptozotocin (STZ) induced diabetic rats.
Methods: Seventy adult male wistar rats were divided into seven groups (n=10). Group A, control
rats; Group B, untreated diabetic rats; Group C, diabetic rats in which C. zambesicus therapy started
2 weeks prior to induction of diabetes; Group D, diabetic rats administered orally with C. zambesicus
leafextract for 2 weeks after the initial four weeks of diabetic induction; Group E, diabetic rats
administered orally with C. zambesicus leaf extract for 4 weeks after the initial four weeks of diabetic
induction; Group F, normal rats administered orally with C. zambesicus leaf extract for four weeks;
Group G, diabetic rats administered with glimepiride (2 mg/kg/day) for four weeks after the
initial four weeks of diabetic induction. At the end of the experimental period, the animals were weighed
and sacrificed. Serum was obtained for TP, ALB, LDH and G6PDH analysis using respective
diagnostic kits.
Results: The results showed an improvement in protein metaboloites (TP, ALB, GLO) whiles the LDH
and G6PDH in the extract and glimepiride treated groups were restored near normal level when
compared with normal control (group A).
Conclusion: In conclusion, this study showed that C. zambesicus leaf extract exerts positive effects
on serum levels of TP, ALB, GLO, LDH and G6PDH in diabetic rats. Thus, ethanolic leaf extract
of Croton zambesicus can be adopted in the management of diabetes mellitus
Effect of bandage materials on epidermal antenna
This study explores the effect of different types of bandages on the performance of an epidermal antenna. Three identical dipole antennas are designed on three different types of bandages, and the measured reflection coefficients, S11, show that the antennas resonate at the same frequency despite the different types of fabric bandages. However, the antennas resonance frequency shifts to a lower frequency when the antennas are mounted on the body. The transmission coefficient, S21, over a 60 cm link with a standard RFID antenna is at least −30 dB, and −34 dB in free space and on the body, respectively, demonstrating that the antenna is suitable for communication and wireless RF power transfer in wearable applications
Flexible piezoelectric nano-composite films for kinetic energy harvesting from textiles
This paper details the enhancements in the dielectric and piezoelectric properties of a low-temperature screen-printable piezoelectric nano-composite film on flexible plastic and textile substrates. These enhancements involved adding silver nano particles to the nano-composite material and using an additional cold isostatic pressing (CIP) post-processing procedure. These developments have resulted in a 18% increase in the free-standing piezoelectric charge coefficient d33 to a value of 98 pC/N. The increase in the dielectric constant of the piezoelectric film has, however, resulted in a decrease in the peak output voltage of the composite film. The potential for this material to be used to harvest mechanical energy from a variety of textiles under compressive and bending forces has been evaluated theoretically and experimentally. The maximum energy density of the enhanced piezoelectric material under 800 N compressive force was found to be 34 J/m3 on a Kermel textile. The maximum energy density of the enhanced piezoelectric material under bending was found to be 14.3 J/m3 on a cotton textile. These results agree very favourably with the theoretical predictions. For a 10x10 cm piezoelectric element 100 µm thick this equates to 38 μJ and 14.3 μJ of energy generated per mechanical action respectively which is a potentially useful amount of energy
A wearable all-printed textile-based 6.78 MHz 15 W-output wireless power transfer system and its screen-printed Joule heater application
While research in passive flexible circuits for Wireless Power Transfer (WPT) such as coils and resonators continues to advance, limitations in their power handling and low efficiency have hindered the realization of efficient all-printed high-power wearable WPT receivers. Here, we propose a screen-printed textile-based 6.78 MHz resonant inductive WPT system using planar inductors with concealed metal-insulator-metal (MIM) tuning capacitors. A printed voltage doubler rectifier based on Silicon Carbide (SiC) diodes is designed and integrated with the coils, showing a power conversion efficiency of 80-90% for 2-40 W inputs over a wide load range. Compared to prior wearable WPT receivers, it offers an order of magnitude improvement in power handling along with higher efficiency (approaching 60%), while using all-printed passives and a compact rectifier. The coils exhibit a simulated Specific Absorption Rate (SAR) under 0.4 W/kg for 25 W received power, and under 21∘C increase in the coils' temperature for a 15 W DC output. Additional fabric shielding is investigated, reducing harmonics emissions by up to 17 dB. We finally demonstrate a wirelessly-powered textile-based carbon-silver Joule heater, capable of reaching up to 60∘C at 2 cm separation from the transmitter, as a wearable application which can only be wireless-powered using the proposed system
A novel design of multi-epitope based vaccine against Escherichia coli
Background: Multi-valent based vaccines have advantage over conventional vaccines because of its multi-faceted action targeted at antigen; thereby raising hope of a more sustained actions against allergens. Escherichia coli (E. coli) is a bacterium that is commonly found in the gut of humans and warm-blooded animals. An increasing number of outbreaks are associated with the consumption of fruits and vegetables (including sprouts, spinach, lettuce, coleslaw, and salad) thereby contamination may be due to contact with faeces from domestic or wild animals at some stages during cultivation or handling. Due to the reported increase in resistance to antibiotics used for Escherichia coli control; an effective vaccine is a would-be alternative of proven interest. Hence, a need for a rational, strategic, and efficient vaccine candidate against E.coli is of paramount necessity by the use of the most current bioinformatics tools to achieve this task. Method: In this study, immunoinformatics tools mined from diverse molecular databases were used for a novel putative epitope based oral vaccine against E.coli. The prospective vaccine proteins were carefully screened and validated to achieve a high thorough-put three-dimensional protein structure. The eventual propsective vaccine candidate proteins was evaluated for its non-allergenicity, antigenicity, solubility, appropriate molecular weight testing and isoelectric point evaluation. Conclusion: The resultant vaccine candidate could serve as a promising anti-E.coli vaccine candidate. Immunoinformatics is a new field over pharmaco-therapeutics; this newest technology should continue to be a rescue from age-long traditional approach in vaccine developments
Willingness of Family Caregivers to Consent to Relative’s Postmortem Examination that Die Suddenly in a Nigerian Tertiary Hospital
BACKGROUND: Postmortem examination is necessary to diagnose the cause of sudden death, and family caregivers are expected to consent to this examination. This study assessed knowledge, attitude, practices and willingness of family caregivers to consent to postmortem examination of their relative if they die suddenly in a Nigerian tertiary hospital.METHODS: Descriptive cross-sectional study of family caregivers of our patients that completed an interviewer administered semistructured questionnaire assessing their knowledge, attitude, practices and willingness to consent to postmortem examination of their relative if they die suddenly. Data were analyzed using descriptive and inferential statistics.RESULTS: A total of 224 caregivers were interviewed. The mean age (SD) was 34.95 (11.74), ranging 22-75 years. They were parents (32.6%), siblings (37.9%), spouses (11.2%) and other relatives (18.3%). Only 17% had adequate knowledge, 44.6% positive attitude and 11.2% good practices to postmortem examination of sudden death. The majority (75.9%) would consent to postmortem examination of their relatives if they die suddenly. Sociodemographic variables associated with willingness to consent to postmortem examination after relative’s sudden death include being male (AOR 3.61; 95%CI 3.09-8.92; p=0.001), having tertiary education (AOR 4.83; 95%CI 1.01-8.29; p=0.034), Christianity (AOR 2.59; 95%CI 1.25-5.35; p=0.010) and skilled worker (AOR 1.43; 95%CI 1.33-3.80; p=0.020).CONCLUSION: Some family caregivers would not consent to postmortem examination of their relatives when they die suddenly. Sensitization programs targeting family caregivers are necessary to increase knowledge and enhance prevention of sudden death as well as improve willingness to consent to postmortem examination when their relatives die suddenly
A Novel Screen-Printed Textile Interface for High-Density Electromyography Recording
Recording electrical muscle activity using a dense matrix of detection points (high-density electromyography, EMG) is of interest in a range of different applications, from human-machine interfacing to rehabilitation and clinical assessment. The wider application of high-density EMG is, however, limited as the clinical interfaces are not convenient for practical use (e.g., require conductive gel/cream). In the present study, we describe a novel dry electrode (TEX) in which the matrix of sensing pads is screen printed on textile and then coated with a soft polymer to ensure good skin-electrode contact. To benchmark the novel solution, an identical electrode was produced using state-of-the-art technology (polyethylene terephthalate with hydrogel, PET) and a process that ensured a high-quality sample. The two electrodes were then compared in terms of signal quality as well as functional application. The tests showed that the signals collected using PET and TEX were characterised by similar spectra, magnitude, spatial distribution and signal-to-noise ratio. The electrodes were used by seven healthy subjects and an amputee participant to recognise seven hand gestures, leading to similar performance during offline analysis and online control. The comprehensive assessment, therefore, demonstrated that the proposed textile interface is an attractive solution for practical applications
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