43 research outputs found

    The effect of bubble surface charge on phonophoresis: Implication in transdermal piroxicam delivery

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    It is over several decades that ultrasound is used to enhance the transdermal drug delivery (phonphoresis). The mechanism of the enhancement is not fully understood and the ability of ultrasound on the enhancement for some drugs is unclear. The effect of continuous wave 870 KHz ultrasound at intensity of 1 W/cm2 for 15 minutes on transdermal absorption of piroxicam from solution and gel formulations in hairless rat skin was studied. Exposure to ultrasound increased the rate of diffusion from gel and solution of piroxicam to 10 and 3 times higher than that in skins not exposed to ultrasound. We strongly believe that the lower diffusion of piroxicam from the solution is caused by extra-bubbles generated by ultrasound. It can be suggested that cavitation activity and its negative surface charges play a dominant rule in phonophoresis. Copyright © 2006 by Razi Institute for Drug Research (RIDR)

    Evaluation of influencing factors on the radiation dose of hospitalized neonates: Maturity status and type of disease

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    Context: Premature neonates have multiple medical and surgical problems; therefore, hospitalization and imaging are required. Recently there has been too much concern about the long-term effects of radiation in neonates. In this survey, we assessed the frequency of imaging and radiation dose in neonates hospitalized in neonatal intensive care unit (NICU) in our University-affiliated hospital. Materials and methods: This was a retrospective cross-sectional study conducted during a year (2019–2020) on 291 neonates. The information has been gathered from Health Information System and picture archiving and communication system, and analyzed with SPSS version 22. Results: 291 neonates were included in the study, from which 175 (60%) neonates were preterm and 116 (40%) neonates were term neonates. The mean gestational age (GA) was 35.5 weeks and the mean hospital admission duration was 15.8 days. The mean number of portable and non-portable imaging procedures was 5.13 and 0.62 for preterm and term neonates, respectively. There is a statistically significant relationship between gastrointestinal disease and the number of abdominal X-rays. There is also a statistically significant relationship between acute respiratory distress syndrome (ARDS) and chest X-rays; there is no statistically significant relationship between pneumonia and the number of chest X-rays in the hospital course. The mean accumulation effective doses in preterm and term neonates in-hospital course were 0.549 and 0.498 mSv, respectively. Discussion: The neonates in NICU are more susceptible to radiation hazards due to numerous imaging than other neonates. Portable imaging is eight times more dosing than non-portable imaging, so due to the scattered radiation from portable devices, the actual radiation dose may be higher than what we estimated. No brain CT scan was done for the neonates with convulsion because of using safer and more valuable modalities; so we could recommend radiologists and pediatrics to use substitute modalities like sonography and MRI instead of CT scan and X-rays

    Evaluation of influencing factors on the radiation dose of hospitalized neonates: Maturity status and type of disease

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    Context: Premature neonates have multiple medical and surgical problems; therefore, hospitalization and imaging are required. Recently there has been too much concern about the long-term effects of radiation in neonates. In this survey, we assessed the frequency of imaging and radiation dose in neonates hospitalized in neonatal intensive care unit (NICU) in our University-affiliated hospital. Materials and methods: This was a retrospective cross-sectional study conducted during a year (2019–2020) on 291 neonates. The information has been gathered from Health Information System and picture archiving and communication system, and analyzed with SPSS version 22. Results: 291 neonates were included in the study, from which 175 (60%) neonates were preterm and 116 (40%) neonates were term neonates. The mean gestational age (GA) was 35.5 weeks and the mean hospital admission duration was 15.8 days. The mean number of portable and non-portable imaging procedures was 5.13 and 0.62 for preterm and term neonates, respectively. There is a statistically significant relationship between gastrointestinal disease and the number of abdominal X-rays. There is also a statistically significant relationship between acute respiratory distress syndrome (ARDS) and chest X-rays; there is no statistically significant relationship between pneumonia and the number of chest X-rays in the hospital course. The mean accumulation effective doses in preterm and term neonates in-hospital course were 0.549 and 0.498 mSv, respectively. Discussion: The neonates in NICU are more susceptible to radiation hazards due to numerous imaging than other neonates. Portable imaging is eight times more dosing than non-portable imaging, so due to the scattered radiation from portable devices, the actual radiation dose may be higher than what we estimated. No brain CT scan was done for the neonates with convulsion because of using safer and more valuable modalities; so we could recommend radiologists and pediatrics to use substitute modalities like sonography and MRI instead of CT scan and X-rays.</jats:p

    Shoot tip regeneration and optimization of Agrobacterium tumefaciens-mediated transformation of Broccoli (Brassica oleracea var. italica) cv. Green Marvel

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    A protocol of plant regeneration from shoot tips and optimization of Agrobacterium tumefaciens-mediated transformation of broccoli (Brassica oleracea var. italica) cv. Green Marvel have been developed. Shoot tip response was assessed on Murashige and Skoog (MS) medium supplemented with different concentrations of zeatin. The highest regeneration with a maximum of 13 shoots per explant was obtained on MS medium containing 1.5 mg l-1 zeatin. Primary selection of putative transformed explants was performed on the optimized regeneration medium (MS medium containing 1.5 mg l-1 zeatin and 80 mg l-1 kanamycin) for 60 days. The effects of preculture, acetosyringone and growth of bacterial culture were studied. Explants precultured on callus induction medium for 4 days prior to inoculation with A. tumefaciens with 200 lM acetosyringone resulted in improved transformation frequency. The Agrobacterium culture dilution of 1:5 and inoculation time of 30 min increased the efficiency of transformation of shoot tip explants. The results also indicated that 150 mg l-1 ampicillin alone was adequate to eradicate Agrobacterium growth in the SRM incorporated with the respective minimum inhibitory concentration of 80 mg l-1 kanamycin. The polymerase chain reaction (PCR) and Southern blot assays confirmed the transgenic status of the broccoli cv. Green Marvel regenerants. A transformation efficiency of 5 % was achieved based on the positive PCR results using the optimized procedure. The expression of luciferase reporter gene in the transformed cells and the transcription of AtHSP101 using RT-PCR further confirmed the transgenic status of the regenerated plants

    Copper(II) Binding to the Intrinsically Disordered C‑Terminal Peptide of SARS-CoV‑2 Virulence Factor Nsp1

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    The first encoded SARS-CoV-2 protein (Nsp1) binds to the human 40S ribosome and blocks synthesis of host proteins, thereby inhibiting critical elements of the innate immune response. The final 33 residues of the natively unstructured Nsp1 C-terminus adopt a helix-turn-helix geometry upon binding to the ribosome. We have characterized the fluctuating conformations of this peptide using circular dichroism spectroscopy along with measurements of tryptophan fluorescence and energy transfer. Tryptophan fluorescence decay kinetics reveal that copper­(II) binds to the peptide at micromolar concentrations, and electron paramagnetic resonance spectroscopy indicates that the metal ion coordinates to the lone histidine residue
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