Obstetrical Ultrasound During Pregnancy

No relevant evidence was identified comparing the safety of frequent obstetrical ultrasounds compared to the routine use of obstetrical ultrasound during pregnancy. This review identified 10 evidence-based guidelines that provided recommendations regarding various indications for obstetrical ultrasound, as well as the frequency of obstetrical ultrasound; however, the methodological rigour of these guidelines is limited and recommendations should be interpreted with caution. One guideline recommended against obstetrical ultrasound for non-medical purposes and recommended that ultrasound exposure be as low as reasonably possible during pregnancy. These recommendations were based on moderate-quality evidence and expert opinion, and should be interpreted with caution. The guidelines made recommendations for specific patient populations for whom more frequent obstetrical ultrasound examinations may be required. These populations included pregnancies affected by certain congenital infections, people pregnant with twins, pregnant adolescents, and pregnant people at high risk for fetal anomalies or for whom mid-trimester transabdominal ultrasound would be challenging.

Ultrasound exposure enhances cellular uptake of nanoscale cargos

DNA nanotechnology utilizes DNA as a structural molecule to design palette of nanostructures with different shapes and sizes. DNA nanocages have demonstrated significant potential for drug delivery. Therefore, enhancing the delivery of DNA nanocages into cells can improve their efficacy as drug delivery agents. Numerous studies have reported the effects of ultrasound for enhancing drug delivery across biological barriers. The mechanical bioeffects caused by cell-ultrasound interaction can cause sonoporation, leading to enhanced uptake of drugs, nanoparticles, and chemotherapeutic agents through membranes. Whether ultrasound exposure can enhance the delivery of DNA nanocages has not been explored, which is the focus of this study. Specifically, we investigated the effects of ultrasound on the cellular uptake of propidium Iodide, fluorescent dextrans, and DNA nanostructures). We provide evidence of modulation of pore formation in the cell membrane by ultrasound by studying the intracellular uptake of the impermeable dye, propidium iodide. Treatment of cells with low amplitudes of ultrasound enhanced the uptake of different sizes of dextrans and DNA based nanodevices. These findings could serve as the foundation for further development ultrasound-enabled DNA nanostructure delivery and for specific understanding of underlying biological mechanisms of interaction between ultrasound parameters and cellular components; the knowledge that can be further explored for potential biological and biomedical applications.

Microscale concert hall acoustics to produce uniform ultrasound stimulation for targeted sonogenetics in hsTRPA1-transfected cells

The field of ultrasound neuromodulation has rapidly developed over the past decade, a consequence of the discovery of strain-sensitive structures in the membrane and organelles of cells extending into the brain, heart, and other organs. Notably, clinical trials are underway for treating epilepsy using focused ultrasound to elicit an organized local electrical response. A key limitation to this approach is the formation of standing waves within the skull. In standing acoustic waves, the maximum ultrasound intensity spatially varies from near zero to double the mean in one half a wavelength, and can lead to localized tissue damage and disruption of normal brain function while attempting to evoke a broader response. This phenomenon also produces a large spatial variation in the actual ultrasound exposure in tissue, leading to heterogeneous results and challenges with interpreting these effects. One approach to overcome this limitation is presented herein: transducer-mounted diffusers that result in spatiotemporally incoherent ultrasound. The signal is numerically and experimentally quantified in an enclosed domain with and without the diffuser. Specifically, we show that adding the diffuser leads to a two-fold increase in ultrasound responsiveness of hsTRPA1 transfected HEK cells. Furthermore, we demonstrate the diffuser allow us to produce an uniform spatial distribution of pressure in the rodent skull. Collectively, we propose that our approach leads to a means to deliver uniform ultrasound into irregular cavities for sonogenetics.

Low frequency ultrasound as an enhancer for the germination process of Stizolobium pruriens

Mucuna (Stizolobium pruriens) is widely used in agriculture as a green allowance and in crop rotation, due to its ability to fix nitrogen and recover degraded areas; without embargo, there is a slow and uneven germination. This study used some classical methods, together with the use of low-frequency ultrasound to accelerate and homogenize the germination and emergence of the seeds. The experiment was carried out at the Plant Tissue Cultivation Laboratory of the Ilha Solteira Campus, São Paulo, Brazil. The design used was a completely randomized one, with five replications, in a 3x6 factorial scheme, the factors being: three pre-treatments for latency break: mechanical scarification, thermal scarification, and without scarification with six levels of ultrasound exposure: 0, 1, 2, 3, 5, 8 min, totaling 18 treatments. For eight days the germination and the initial stages of the seedlings were controlled. The method without scarification subjected to 4.5 min of ultrasound can become an excellent alternative, since it presented greater germination vigor, while 3.14 min of exposure to ultrasound were enough to improve the emergence speed, regardless of the method used in the preparation of seeds. In conclusion, only with the use of low-frequency ultrasound, it is possible to improve both the germination speed index and the germination vigor, without the need for additional treatments.

Effectiveness of ultrasound-guided cannulation of AVF on infiltration rates: A single center quality improvement study

Though ultrasonography is increasingly used throughout the spectrum of hemodialysis access, its role in outpatient dialysis units in the United States has been limited so far. This may, in part, be due to limited ultrasound exposure, knowledge and training of dialysis staff. We implemented a quality improvement initiative in our dialysis units to expand the use of ultrasound by our frontline dialysis staff to prospectively evaluate newly placed AVF and guide cannulation. This manuscript describes our experience and the impact of our protocol on infiltration rates in our outpatient HD units.

Beta-Carotene Extraction in Complex Food Additives

Introduction. Natural dye beta-carotene E160a (pro-vitamin A) is part of many functional foods. Therefore, the total intake of beta-carotene must not exceed the tolerable upper intake level, i.e. 10 mg/day. E160a is also used in formulations of complex food additives. These products contain antioxidants, emulsifiers, preservatives, carriers, stabilizers, and thickeners, which makes it make difficult to isolate and determine the amount of beta-carotene. Complex food additives vary in composition, which, together with incomplete extraction and degradation of beta-carotene, results in inaccuracy of its determination. The present research reviewed various techniques of beta-carotene extraction from liquid and dry complex food additives. Study objects and methods. The study featured commercial samples of complex food additives containing beta-carotene. It was isolated from the samples by liquid extraction methods using organic solvents and their binary mixtures. The extraction was performed in a stirring device at 120 rpm and in a Bandelin Sonorex ultrasonic bath at 128 W and 35 kHz. The extraction continued until the samples were completely discolored. The list of solvents included chloroform, petroleum ether, hexane, acetone, ethanol, and their mixes. The experiment was based on high performance thin layer chromatography with Sorbfil sheet plates. The optical density was determined by spectrophotometry using a SHIMADZU UV-1800 device. Results and discussion. The extraction of beta-carotene from liquid samples with mechanical stirring at 120 rpm led to the formation of stable opaque emulsions, which made it difficult to determine the amount of beta-carotene. The emulsions were destroyed by ultrasound exposure for 30 min. The degree of extraction of beta-carotene from liquid emulsion systems (≥ 95%) was achieved by ultrasonic extraction with chloroform or a binary extractant based on mixes of acetone with chloroform, hexane, or petroleum ether in volumetric ratios of 1:1. When extracted from dry samples using chloroform or binary extractants, beta-carotene was not isolated or was not completely isolated. As a result, pre-dispersion of dry samples in water with stirring at 120 rpm was proposed. Ultrasonic treatment did not contribute to the dispersion of dry samples due to insufficient cavitation action. Ethanol, which is a solubilizer, increased the extractability of beta-carotene up to 98 %. The optimal results were achieved by adding a binary extractant (ethanol:chloroform in a 1:2 ratio) to an aqueous solution of the dry sample (1:3). The optimal elution systems were hexane:benzene (9.7:0.3), butanol:methyl ethyl ketone:ammonia 10 % (9:6:6), and petroleum ether:benzene:acetone:acetic acid (23.3:5.8:0.6:0.3). Conclusion. The article offers new methods of beta-carotene isolation from liquid and dry complex food additives of various composition and elution systems for carotene identification. The methods caused no degradation of beta-carotene during extraction and can be used to prepare samples of complex food additives for beta-carotene identification and quantitative analysis.

PHYSICAL PRETREATMENT OF ULVA FASCIATA FOR ENHANCINGBIODIESEL PRODUCTION AND QUALITY

The green algae Ulva faciata was subjected to different physical pretreatments comprising thermal and mechanical techniques at different experimental conditions to state the most appropriate method of cell disruption for increasing the quantity of the extracted lipid and hence improve the quality of the produced biodiesel with low cost. Thermal pretreatment was autoclaving of either wet or dry algal biomass, while mechanical pretreatments include microwave and ultrasonication at different time intervals. The control was the alga without pretreatment extracted at optimum conditions: 60 min, 55oC, shaking speed at 250 rpm, < 0.16 mm particle size with 25:1 v/w solvent to solid ratio. The results showed that the quantity of extracted lipids in case of using all physical pretreatments increased the Total fatty acids yield significantly by about 2-folds of the control for wet algae in hydrothermal treatment with optimum time of treatment 40 minutes, and 1.4 folds for dry algae in thermal pretreatment of the dried alga for 60minutes autoclaving period. The sharp increase by 2.2 folds of extracted lipids was recorded by microwave pretreatment for radiation period (5 min), while ultrasonication showed 2.1-fold increase in lipid yield at 15minutes ultrasound exposure time. Concerning the physical properties of the produced biodiesel after all physical pretreatments, the results indicated that the produced biodiesel had very high quality as all its properties are almost complied with the ASTM D6751 and EN14214 standards. These results were confirmed statistically where all physical pretreatments had high significant effect on fatty acids yield and Biodiesel properties.

Sonoporation generates downstream cellular impact after membrane resealing

Sonoporation via microbubble-mediated ultrasound exposure has shown potential in drug and gene delivery. However, there is a general lack of mechanistic knowledge on sonoporation-induced cellular impact after membrane resealing, and this issue has made it challenging to apply sonoporation efficiently in practice. Here, we present new evidence on how sonoporation, without endangering immediate cell viability, may disrupt downstream cellular hemostasis in ways that are distinguished from the bioeffects observed in other sonicated and unsonoporated cells. Sonoporation was realized on HL-60 leukemia cells by delivering pulsed ultrasound (1 MHz frequency, 0.50 MPa peak negative pressure; 10% duty cycle; 30 s exposure period; 29.1 J/cm2 acoustic energy density) in the presence of lipid-shelled microbubbles (1:1 cell-to-bubble ratio). Results showed that 54.6% of sonoporated cells, despite remaining initially viable, underwent apoptosis or necrosis at 24 h after sonoporation. Anti-proliferation behavior was also observed in sonoporated cells as their subpopulation size was reduced by 43.8% over 24 h. Preceding these cytotoxic events, the percentages of sonoporated cells in different cell cycle phases were found to be altered by 12 h after exposure. As well, for sonoporated cells, their expressions of cytoprotective genes in the heat shock protein-70 (HSP-70) family were upregulated by at least 4.1 fold at 3 h after exposure. Taken altogether, these findings indicate that sonoporated cells attempted to restore homeostasis after membrane resealing, but many of them ultimately failed to recover. Such mechanistic knowledge should be taken into account to devise more efficient sonoporation-mediated therapeutic protocols.