5,074 research outputs found
Sensitivity of Diffusion-Weighted STEAM MRI and EPI-DWI to Infratentorial Ischemic Stroke
Objectives To assess the sensitivity of stimulated echo acquisition mode
diffusion weighted imaging (STEAM-DWI) to ischemic stroke in comparison to
echo-planar imaging diffusion weighted imaging (EPI-DWI) in the infratentorial
compartment. Methods Fifty-seven patients presenting with clinical features of
infratentorial stroke underwent STEAM-DWI, high-resolution EPI-DWI (HR-DWI,
2.5 mm slice thickness) and low-resolution EPI-DWI (LR-DWI, 5 mm slice
thickness). Four readers assessed the presence of ischemic lesions and
artifacts. Agreement between sequences and interobserver agreement on the
presence of ischemia were calculated. The sensitivities of the DWI sequences
were calculated in 45 patients with a confirmed diagnosis of infratentorial
stroke. Results Median time from symptom onset to imaging was 24 hours. STEAM-
DWI agreed with LR-DWI in 89.5% of cases (kappa = 0.72, p<0.0001) and with HR-
DWI in 89.5% of cases (kappa = 0.68, p<0.0001). STEAM-DWI showed fewer
intraparenchymal artifacts (1/57) than HR-DWI (44/57) and LR-DWI (41/57).
Ischemia was visible in 87% of cases for LR-DWI, 93% of cases for HR-DWI, and
89% of cases for STEAM-DWI. Interobserver agreement was good for STEAM-DWI
(kappa = 0.62, p<0.0001). Conclusions Compared to the best currently available
MR sequence for detecting ischemia (HR-DWI), STEAM-DWI shows fewer artifacts
and a similar sensitivity to infratentorial stroke
Histological Sequences of Long Bone Development in the New Zealand White Rabbits
Long bone development occurred through endochondral ossification. The current study investigated the main histological changes associated with the development of humerus from the New Zealand white rabbits. The upper limb or humerus during embryonic (12, 14, 15, 16, 18, 21, 24 and 27 days) and neonatal (3 and 7 days) development was processed for light microscopy. Three stages preceded endochondral ossification; limb bud (mesenchymal cells), cartilage primordia (mesenchymal condensation and differentiation into chondrocytes) and cartilage template (organization of chondrocytes into proliferative and hypertrophic zones) by 12, 14 and 15 days, respectively. At day 16, cartilage template elongated forming a cartilaginous diaphysis of the prospective humerus. At day 18, cartilaginous epiphyses were formed. Medullary cavity was established by day 21 with no signs of calcification in the bone collar. Primary ossification center appeared within the diaphysis at day 24 of embryonic development. Secondary ossification centers were seen within the epiphyses by day 3 of neonatal development. Two types of cartilage canals were investigated; short epiphyseal canals appeared from day 21 and long transphyseal canals appeared from day 27. At day 7 of neonatal development, the cartilage of the humerus was limited in two places; articular epiphyseal growth cartilage between articular surface and secondary ossification center, epiphyseal physeal growth cartilage between the secondary and primary ossification centers. The current study summarized the main histological stages of development of rabbit humerus. These results should be considered in molecular studies of endochondral bone formation
Influence of Degree of Saturation in the Electric Resistivity-Hydraulic Conductivity Relationship
The Impact of Aspect Ratio, Characteristic Strength and Compression Rebars on the Shear Capacity of Shallow RC Beams
This paper investigates the impact of the aspect ratio, the characteristics strength of the concrete, and the compression steel ratio on the shear capacity of wide-shallow beams. An experimental program consists of seven specimens, including a control specimen, all tested under a three-point load test. Three specimens were considered for each parameter (the control specimen was included in all three variables). The experimental results were compared to the theoretical values of six different codes of practice; they were also analyzed to determine the ductility, stiffness, and dissipated energy of each specimen. The results indicated that the shear reinforcement was fully functioning until it yielded, with a minimum contribution of 55% of the total shear capacity of the specimens. The aspect ratio and the characteristic strength had a notable impact on the shear capacity of the specimens, while the compression steel ratio had a minor effect on the shear capacity, but it improved the stiffness and the ductility of the beams. Theoretical concrete shear strengths from design codes ranged between 77 and 163% of the experimental values; EN-1992 was the closest code to the experimental results. A comparison between the experimental results and predicted values using GP and EPR methods from previous research showed accuracies of 72% and 81%, respectively. Doi: 10.28991/CEJ-2023-09-09-012 Full Text: PD
Encapsulated polycaprolactone with triazole derivatives and selenium nanoparticles as promising antiproliferative and anticancer agents
Background and purpose
Polycaprolactone nanocapsules incorporated with triazole derivatives in the presence and absence of selenium nanoparticles were prepared and evaluated as antiproliferative and anticancer agents. Polycaprolactone nanoparticles were prepared using the emulsion technique.
Experimental approach
The prepared capsules were characterized using FT-IR, TEM and DLS measurements. The synthesized triazolopyrimidine derivative in the presence and absence of selenium nanoparticles encapsulated in polycaprolactone was tested for its in vitro antiproliferative efficiency towards human breast cancer cell line (MCF7) and murine fibroblast normal cell line (BALB/3T3) in comparison to doxorubicin as a standard anticancer drug.
Key results
The results indicated that encapsulated polycaprolactone with selenium nanoparticles (SeNPs) and triazole-SeNPs were the most potent samples against the tested breast cancer cell line (MCF7). On the other hand, all compounds showed weak or moderate activities towards the tested murine fibroblast normal cell line (BALB/3T3).
Conclusion
As the safety index (SI) was higher than 1.0, it expanded the way for newly synthesized compounds to express antiproliferative efficacy against tumour cells. Hence, these compounds may be considered promising ones. However, they should be examined through further in-vivo and pharmacokinetic studies
Genetic and histopathology studies on mice: Effect of fenugreek oil on the efficiency of ovarian and liver tissues
There is a growing interest in understanding the biological effect of medicinal plants. In the present investigation, the effects of fenugreek oil administration on the liver and ovarian activity genetically (i.e., meiotic progression in collected oocytes as well as changes in DNA and RNA content in the liver and ovarian tissues) and histopathologically (i.e., alterations in the liver and ovarian tissues) were examined in mice. Swiss albino female mice were orally administrated with different doses of fenugreek oil for 10 days. The mode and magnitude of effect were found to be depending on the dose of fenugreek oil and type of tissue. Administration with fenugreek oil at 0.1 and 0.15 ml/mouse increased the total number of cumulus-oocyte complexes as well as improved their quality. Cytogenetically, fenugreek oil was able to stimulate the oocytes collected from treated mice at all doses to progress in meiosis. Levels of nucleic acids content in all groups did not significantly change neither in the DNA nor RNA in ovarian- or liver-tissues. Histopathological examination of the ovaries collected from untreated mice as well as from mice treated with 0.05 ml/mouse of fenugreek oil showed no histopathological alterations. However, ovaries of mice treated with 0.1 or 0.15 ml/mouse of fenugreek oil showed improvement in several tissues. To our knowledge, this is the first study that suggests significant stimulating effects of fenugreek oil on the ovarian activity in mice.Keywords: Fenugreek, mice, ovaries, oocytes, meiosis, DNA, RNA, histopatholog
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