Influence of shock wave propagation on dielectric barrier discharge plasma actuator performance

Interest in plasma actuators as active flow control devices is growing rapidly due to their lack of mechanical parts, light weight and high response frequency. Although the flow induced by these actuators has received much attention, the effect that the external flow has on the performance of the actuator itself must also be considered, especially the influence of unsteady high-speed flows which are fast becoming a norm in the operating flight envelopes. The primary objective of this study is to examine the characteristics of a dielectric barrier discharge (DBD) plasma actuator when exposed to an unsteady flow generated by a shock tube. This type of flow, which is often used in different studies, contains a range of flow regimes from sudden pressure and density changes to relatively uniform high-speed flow regions. A small circular shock tube is employed along with the schlieren photography technique to visualize the flow. The voltage and current traces of the plasma actuator are monitored throughout, and using the well-established shock tube theory the change in the actuator characteristics are related to the physical processes which occur inside the shock tube. The results show that not only is the shear layer outside of the shock tube affected by the plasma but the passage of the shock front and high-speed flow behind it also greatly influences the properties of the plasma

Dizajniranje i vrednovanje bioadhezijskog filma za transdermalnu isporuku propranolol hidroklorida

The objective of the study was to develop a suitable transdermal delivery system for propranolol hydrochloride (PPL) via employing chitosan as a film former. Drug concentration uniformity, thickness, moisture uptake capacity and skin bioadhesion of the films were characterized. The effects of chitosan and PPL concentration and different penetration enhancers on the release and permeation profiles from the films were investigated. Skin irritation of the candidate film was evaluated. Chitosan film (PPL 2 mg cm2, chitosan 2 % m/m, cineol 10 %, m/m) was found non-irritant and achieved 88.2 % release after 8 hours in phosphate buffer. Significant high (p < 0.001) permeation of PPL through rat skin was obtained using this film compared to the film without enhancer (about 8 times enhancement factor), making it a promising transdermal delivery system for PPL.Cilj rada bio je razvoj pogodnog transdermalnog sustava na bazi kitozana za isporuku propranolol hidroklorida (PPL). Svim pripravcima ispitana je jednoličnost udjela lijeka, debljina, sposobnost vlaženja i bioadhezivnost na kožu. Ispitivan je i utjecaj kitozana, koncentracije PPL-a i sredstva za povećanje permeacije na oslobađanje i permeacijski profil, te potencijalni iritacijski učinak na kožu. Iz kitozanskog filma (PPL 2 mg cm2, 2 %, m/m, kitozana i 10 %, m/m, cineola), koji nije djelovao iritabilno, postignuto je 88,2 % oslobađanja nakon 8 sati u fosfatnom puferu. S ovim pripravkom postignuta je i vrlo značajna (p < 0,001) permeacija PPL kroz kožu štakora, oko osam puta veća u usporedbi s filmom bez sredstva za povećanje permeacije. Pripravak bi se mogao upotrijebiti za transdermalnu isporuku PPL

Rectal gel application of Withania somnifera root extract expounds anti-inflammatory and muco-restorative activity in TNBS-induced Inflammatory Bowel Disease

<p>Abstract</p> <p>Background</p> <p>Inflammatory Bowel Disease (IBD) is marked with chronic inflammation of intestinal epithelium driven by oxidative stress. Traditional treatments with plant extracts gained renewed interest due to their ability to ameliorate the multi factorial conditions like inflammation. We investigated the beneficial effects of <it>Withania somnifera </it>in Trinitro Benzyl Sulfonic Acid (TNBS) induced experimental IBD through a rectally applicable formulation.</p> <p>Methods</p> <p>The study included (i) preparation of gel formulation from aqueous <it>Withania somnifera </it>root extract (WSRE), (ii) biochemical assays to determine its performance potential, (iii) testing of formulation efficacy in TNBS-induced IBD rat model, and (iv) histo-patholgical studies to assess its healing and muco-regenerative effect in IBD-induced rats. For this purpose, concentration dependant antioxidant activity of the extracts were evaluated using biochemical assays like (a) inhibition of lipid peroxidation, (b) NO scavenging, (c) H₂O₂scavenging, and (d) ferric reducing power assay.</p> <p>Results</p> <p>The extract, at 500 μg/ml, the highest concentration tested, showed 95.6% inhibition of lipid peroxidation, 14.8% NO scavenging, 81.79% H₂O₂scavenging and a reducing capacity of 0.80. The results were comparable with standard antioxidants, ascorbic acid and curcumin. WSRE treatment positively scored on histopathological parameters like necrosis, edema, neutrophil infiltration. The post treatment intestinal features showed restoration at par with the healthy intestine. In view of these results, gel formulation containing an aqueous extract of <it>W. somnifera</it>, prepared for rectal application was tested for its anti-inflammatory activity in TNBS-induced rat models for IBD. Commercially available anti-inflammatory drug Mesalamine was used as the standard in this assay.</p> <p>Conclusions</p> <p>Dose of the rectal gel applied at 1000 mg of WSRE per kg rat weight showed significant muco-restorative efficacy in the IBD-induced rats, validated by histo-pathological studies.</p

The apoptosis-inducing activity towards leukemia and lymphoma cells in a cyanobacterial culture collection is not associated with mouse bioassay toxicity

Cyanobacteria (83 strains and seven natural populations) were screened for content of apoptosis (cell death)-inducing activity towards neoplastic cells of the immune (jurkat acute T-cell lymphoma) and hematopoetic (acute myelogenic leukemia) lineage. Apoptogenic activity was frequent, even in strains cultured for decades, and was unrelated to whether the cyanobacteria had been collected from polar, temperate, or tropic environments. The activity was more abundant in the genera Anabaena and Microcystis compared to Nostoc, Phormidium, Planktothrix, and Pseudanabaena. Whereas the T-cell lymphoma apoptogens were frequent in organic extracts, the cell death-inducing activity towards leukemia cells resided mainly in aqueous extracts. The cyanobacteria were from a culture collection established for public health purposes to detect toxic cyanobacterial blooms, and 54 of them were tested for toxicity by the mouse bioassay. We found no correlation between the apoptogenic activity in the cyanobacterial isolates with their content of microcystin, nor with their ability to elicit a positive standard mouse bioassay. Several strains produced more than one apoptogen, differing in biophysical or biological activity. In fact, two strains contained microcystin in addition to one apoptogen specific for the AML cells, and one apoptogen specific for the T-cell lymphoma. This study shows the potential of cyanobacterial culture collections as libraries for bioactive compounds, since strains kept in cultures for decades produced apoptogens unrelated to the mouse bioassay detectable bloom-associated toxins

Bak Compensated for Bax in p53-null Cells to Release Cytochrome c for the Initiation of Mitochondrial Signaling during Withanolide D-Induced Apoptosis

The goal of cancer chemotherapy to induce multi-directional apoptosis as targeting a single pathway is unable to decrease all the downstream effect arises from crosstalk. Present study reports that Withanolide D (WithaD), a steroidal lactone isolated from Withania somnifera, induced cellular apoptosis in which mitochondria and p53 were intricately involved. In MOLT-3 and HCT116p53+/+ cells, WithaD induced crosstalk between intrinsic and extrinsic signaling through Bid, whereas in K562 and HCT116p53−/− cells, only intrinsic pathway was activated where Bid remain unaltered. WithaD showed pronounced activation of p53 in cancer cells. Moreover, lowered apoptogenic effect of HCT116p53−/− over HCT116p53+/+ established a strong correlation between WithaD-mediated apoptosis and p53. WithaD induced Bax and Bak upregulation in HCT116p53+/+, whereas increase only Bak expression in HCT116p53−/− cells, which was coordinated with augmented p53 expression. p53 inhibition substantially reduced Bax level and failed to inhibit Bak upregulation in HCT116p53+/+ cells confirming p53-dependent Bax and p53-independent Bak activation. Additionally, in HCT116p53+/+ cells, combined loss of Bax and Bak (HCT116Bax−Bak−) reduced WithaD-induced apoptosis and completely blocked cytochrome c release whereas single loss of Bax or Bak (HCT116Bax−Bak+/HCT116Bax+Bak−) was only marginally effective after WithaD treatment. In HCT116p53−/− cells, though Bax translocation to mitochondria was abrogated, Bak oligomerization helped the cells to release cytochrome c even before the disruption of mitochondrial membrane potential. WithaD also showed in vitro growth-inhibitory activity against an array of p53 wild type and null cancer cells and K562 xenograft in vivo. Taken together, WithaD elicited apoptosis in malignant cells through Bax/Bak dependent pathway in p53-wild type cells, whereas Bak compensated against loss of Bax in p53-null cells

Tele-Neuro-Ophthalmology During the Age of COVID-19

This article is made available for unrestricted research re-use and secondary analysis in any form or be any means with acknowledgement of the original source. These permissions are granted for the duration of the World Health Organization (WHO) declaration of COVID-19 as a global pandemic.In this article, we present possible “best practices” for neuro-ophthalmologists to design and implement tele-neuro-ophthalmology during and following this national and international crisis. We review the previsit, intravisit, and postvisit steps in a practical manner that we hope will be of value to practicing neuro-ophthalmologists. We include sections on how to appropriately implement telemedicine and patient selection, focusing on different types of visits, determining eligible patients, and triaging patients. In addition, we outline the software and hardware requirements for the electronic medical record (EMR), including Epic and non-Epic platforms. We also describe the nuts and bolts of how to get started, including descriptions of the multiple useful applications and software available. As with any medical encounter, privacy regulations, billing, and coding can be significant hurdles to implementation, and we discuss each in detail. We hope that this article will be of use for neuro-ophthalmologists, comprehensive ophthalmologists, and general neurologists because we deal with effects and aftereffects of this COVID-19 pandemic. We believe that this current disruptive innovation will drive the future of telemedicine in neuro-ophthalmology

Telemedicine Evaluations in Neuro-Ophthalmology During the COVID19 Pandemic: Patient and Physician Surveys

Background: The novel coronavirus 2019 (COVID-19) pandemic has transformed healthcare. With the need to limit COVID-19 exposures, telemedicine has become an increasingly important format for clinical care. Compared to other fields, neuro-ophthalmology faces unique challenges given its dependence on physical examination signs that are difficult to elicit outside the office setting. As such, it is imperative to understand both patient and provider experiences in order to continue to adapt the technology and tailor its application. The purpose of this study is to analyze both neuro-ophthalmology physician and patient satisfaction with virtual health visits during the time of the COVID-19 pandemic. Methods: Across three institutions (NYU Langone Health, Indiana University Health, and Columbia University Medical Center), telemedicine surveys were administered to 159 patients. Neuro-ophthalmologists completed 157 surveys; each of these were linked to a single patient visit. Patient surveys consisted of five questions regarding visit preparation, satisfaction, challenges, and comfort. The physician survey included four questions that focused on ability to gather specific clinical information by history and examination. Results: Among 159 patients, 104 (65.4%) reported that they were satisfied with the visit, and 149 (93.7%) indicated that they were comfortable asking questions. Sixty-eight (73.9%) patients found the instructions provided prior to the visit easy to understand. Potential areas for improvement noted by patients included more detailed preparation instructions and better technology (phone positioning, internet connection, software). Over 87% (137/157) of neuroophthalmologists surveyed reported having performed an examination that provided enough information for medical decision-making. Some areas of the neuro-ophthalmologic exam were reported to be easy to conduct (range of eye movements, visual acuity, Amsler grids, Ishihara color plates, and pupillary exam). Other components were more difficult (saccades, red desaturation, visual fields, convergence, oscillations, ocular alignment, and smooth pursuit); some were especially challenging (vestibulo-ocular reflex [VOR], VOR suppression, and optokinetic nystagmus). Clinicians noted that virtual health visits were limited by patient preparation, inability to perform certain parts of the examination (funduscopy and pupils), and technological issues. Conclusions: Among virtual neuro-ophthalmology visits evaluated, most offer patients with appointments that satisfy their needs. The majority of physicians in this cohort obtained adequate clinical information for decision-making. Even better technology and instructions may help improve aspects of virtual health visits