945 research outputs found
Effect of a nanocomposite containing ostrich eggshell on calvarium healing in the rabbit: a pathologic study
ΔΕΝ ΔΙΑΤΙΘΕΤΑΙ ΠΕΡΙΛΗΨΗThe aim of the current study was to determine effect of a nanocomposite containing ostrich eggshell (NCOE) on the calvarium healing in the rabbit. Fresh ostrich eggshell was ground (300-500 μm), treated in phosphate-containing solutions and sterilized by gamma irradiation. Fifteen New Zealand white adult male rabbits were used. Four full-thickness skull defects were created in the calvarium. The first defect kept unfilled (control). The second defect was filled with autograft bone. The third defect was filled using NCOE. The fourth defect was filled with mixture of the autograft+NCOE bone. At 30, 60 and 90 days after surgery animals were euthanized and tissue specimens were collected and stained with hematoxylin eosin and trichrome staining method. Microsections were examined toassess the extent and intensity of inflammation, calvarium formation status and foreign body reaction. According to the results, filling defect significantly increased in NCOE-treated rabbits compared to the control group at 30 and 60 days post-surgery (P<0.05). There a statistically significant difference between experimental groups compared to the control group at 30 and 60 days post-surgery (P<0.05) while no statistically significant differences were observed among autograft, NCOE, autograft+NCOE (P>0.05). Also, absorb material significantly decreased in NCOE and autograft+NCOE groups compared to the control group at 60 days post-surgery (P<0.05). The filling defect significantly increased in autograft, NCOE and NCOE+autograft groups compared to the control group at 90 days post-surgery (P<0.05). There was no significant difference on inflammation and absorb material among the groups at 90 days post-surgery (P>0.05). These results suggested NCOE+autograft has improved the rate of calvarium healing in rabbits
Effect of strip cropping of sugar beet-alfalfa on population density of the sugar beet weevil, Lixus incanescens (Col.: Curculionidae) and species diversity of its natural enemies
The sugar beet weevil, Lixus incanescens Boheman, is an important insect pest of sugar beet, Beta vulgaris L., in many parts of Iran. Strip cropping of sugar beet and alfalfa, Medicago sativa L., is a suitable strategy for improving the effectiveness of biocontrol agents of the sugar beet weevil. In this research, the population density of the sugar beet weevil and diversity of its natural enemies were studied in the strip cropping of sugar beet-alfalfa in comparison with the monoculture of sugar beet, in Juvein countryside, Khorasan Razavi province, from 2012 to 2013. In each sampling, the abundance of the sugar beet weevil and its natural enemies per plant were recorded. The densities of the sugar beet weevils in the strip cropping were significantly lower comparing to the monoculture. The larva of the hymenopteran parasitoid species Bracon intercessor Nees in both culture systems as well as seven egg predator species in strip cropping system and three egg predator species in the monoculture system were found. The percentage of larval parasitism and the densities of each predator in the strip cropping were significantly higher than the monoculture. The Shannon diversity index for the complexity of natural enemies in the strip cropping was higher comparing to the monoculture. The value of Morisita-Horn index for the complexity of the natural enemies between the experimental sugar beet cropping systems was calculated as 0.923. Based on these results, we have concluded that the strip cropping of sugar beet-alfalfa leads to higher diversity of natural enemies of the sugar beet weevil and lower population density of L. incanescens. In addition, the quantification of the predators’ species richness and abundance in the sugar beet fields remains as an effective method to improve the management of the sugar beet weevil
Behavior of Braced Sheetpile Excavation in Detroit Clay
This paper presents the design criteria, finite element modeling and actual behavior of a braced sheetpile excavation in Detroit soft clay. Due to the close proximity of existing structures to the excavation, a detailed analysis was performed to design and construct an earth retention system to avoid damage to these structures. The excavation involved a 170 ft by 220 ft area. The maximum depth of excavation was 23.5 ft. The subsurface soil consists of soft to very soft Detroit clay from the excavation level to a depth of 80 ft and has an undrained shear strength as low as 360 psf
Thermal Control of Engineered T-cells
Genetically engineered T-cells are being developed to perform a variety of therapeutic functions. However, no robust mechanisms exist to externally control the activity of T-cells at specific locations within the body. Such spatiotemporal control could help mitigate potential off-target toxicity due to incomplete molecular specificity in applications such as T-cell immunotherapy against solid tumors. Temperature is a versatile external control signal that can be delivered to target tissues in vivo using techniques such as focused ultrasound and magnetic hyperthermia. Here, we test the ability of heat shock promoters to mediate thermal actuation of genetic circuits in primary human T-cells in the well-tolerated temperature range of 37–42 °C, and introduce genetic architectures enabling the tuning of the amplitude and duration of thermal activation. We demonstrate the use of these circuits to control the expression of chimeric antigen receptors and cytokines, and the killing of target tumor cells. This technology provides a critical tool to direct the activity of T-cells after they are deployed inside the body
Performance of a Semi-Rigid Braced Excavation in Soft Clay
Construction of a 21-foot wide, 28-foot deep braced excavation in Detroit soft clays has been completed. In order to protect an existing 50-year old tunnel adjacent to the excavation, a semi-rigid, tangent wall earth retention system was constructed to minimize the soil movements. The tangent wall was formed by 118 drilled piers with 42-inch in diameter and 41-foot long. The maximum soil lateral and vertical movements adjacent to the excavation were controlled below a magnitude of 2.0 inches, while bottom of the excavation experienced about 3 inches of heave. This paper presents the design considerations and construction performance of the retention system based on geotechnical instrumentation data. Prediction of maximum soil lateral movement based on a finite element analysis and a semi-empirical method conformed well with field measurements. Experience learned from the design and construction will be valuable for future construction of braced excavation systems in similar soil conditions
Tunable thermal bioswitches for in vivo control of microbial therapeutics
Temperature is a unique input signal that could be used by engineered microbial therapeutics to sense and respond to host conditions or spatially targeted external triggers such as focused ultrasound. To enable these possibilities, we present two families of tunable, orthogonal, temperature-dependent transcriptional repressors providing switch-like control of bacterial gene expression at thresholds spanning the biomedically relevant range of 32–46°C. We integrate these molecular bioswitches into thermal logic circuits and demonstrate their utility in three in vivo microbial therapy scenarios, including spatially precise activation using focused ultrasound, modulation of activity in response to a host fever, and self-destruction after fecal elimination to prevent environmental escape. This technology provides a critical capability for coupling endogenous or applied thermal signals to cellular function in basic research, biomedical and industrial applications
Comparative Evaluation of the Biochemical Effects of Ketamine plus Ketoprofen and Midazolam in the Premedication of Pigeons
The present study was conducted with the aim of comparing the effects of premedication with ketoprofen and midazolam in birds. A total of 24 male pigeons with an approximate weight of 300 g were divided into four equal groups. The control group (Group I) was injected with ketamine alone. Groups II-IV were injected with ketoprofen alone, ketoprofen+ketamine, and midazolam+ketamine, respectively. The biochemical changes in the four groups were evaluated after intramuscular drug injections at different anesthetic levels. A record of biochemical changes was maintained for each group. Blood samples were taken before and after the administration of the medications in order to measure the levels of serum alkaline phosphatase (ALP), oxaloacetate transaminase (OT), prothrombin time (PT), glucose (GLU), lactate dehydrogenase (LDH), albumin (Alb), total protein (TP), and gamma-glutamyl transferase (GGTF). The results showed significant differences in the mean levels of ALP, OT, PT, GLU, LDH, Alb, and TP after anesthesia, compared to that before anesthesia. Therefore, ketoprofen+ketamine can be used for the induction of anesthesia in birds.The present study was conducted with the aim of comparing the effects of premedication with ketoprofen and midazolam in birds. A total of 24 male pigeons with an approximate weight of 300 g were divided into four equal groups. The control group (Group I) was injected with ketamine alone. Groups II-IV were injected with ketoprofen alone, ketoprofen+ketamine, and midazolam+ketamine, respectively. The biochemical changes in the four groups were evaluated after intramuscular drug injections at different anesthetic levels. A record of biochemical changes was maintained for each group. Blood samples were taken before and after the administration of the medications in order to measure the levels of serum alkaline phosphatase (ALP), oxaloacetate transaminase (OT), prothrombin time (PT), glucose (GLU), lactate dehydrogenase (LDH), albumin (Alb), total protein (TP), and gamma-glutamyl transferase (GGTF). The results showed significant differences in the mean levels of ALP, OT, PT, GLU, LDH, Alb, and TP after anesthesia, compared to that before anesthesia. Therefore, ketoprofen+ketamine can be used for the induction of anesthesia in birds
MicroRNAs and SARS-CoV-2 life cycle, pathogenesis, and mutations: biomarkers or therapeutic agents?
To date, proposed therapies and antiviral drugs have been failed to cure coronavirus disease 2019 (COVID-19) patients. However, at least two drug companies have applied for emergency use authorization with the United States Food and Drug Administration for their coronavirus vaccine candidates and several other vaccines are in various stages of development to determine safety and efficacy. Recently, some studies have shown the role of different human and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) microRNAs (miRNAs) in the pathophysiology of COVID-19. miRNAs are non-coding single-stranded RNAs, which are involved in several physiological and pathological conditions, such as cell proliferation, differentiation, and metabolism. They act as negative regulators of protein synthesis through binding to the 3� untranslated region (3� UTR) of the complementary target mRNA, leading to mRNA degradation or inhibition. The databases of Google Scholar, Scopus, PubMed, and Web of Science were searched for literature regarding the importance of miRNAs in the SARS-CoV-2 life cycle, pathogenesis, and genomic mutations. Furthermore, promising miRNAs as a biomarker or antiviral agent in COVID-19 therapy are reviewed. © 2020 Informa UK Limited, trading as Taylor & Francis Group
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